CA1182114A - Isoimide containing oligomers - Google Patents
Isoimide containing oligomersInfo
- Publication number
- CA1182114A CA1182114A CA000406262A CA406262A CA1182114A CA 1182114 A CA1182114 A CA 1182114A CA 000406262 A CA000406262 A CA 000406262A CA 406262 A CA406262 A CA 406262A CA 1182114 A CA1182114 A CA 1182114A
- Authority
- CA
- Canada
- Prior art keywords
- oligomer
- formula
- isoimide
- specified
- product
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
- C08G73/02—Polyamines
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
- C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
- C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- C08G73/1089—Polyisoimides
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D307/00—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
- C07D307/77—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom ortho- or peri-condensed with carbocyclic rings or ring systems
- C07D307/87—Benzo [c] furans; Hydrogenated benzo [c] furans
- C07D307/90—Benzo [c] furans; Hydrogenated benzo [c] furans with an oxygen atom in position 1 and a nitrogen atom in position 3, or vice versa
Abstract
ABSTRACT OF THE DISCLOSURE
A class of relatively low molecular-weight oligomers containing at least one isoimide group and terminal groups capable of undergoing an addition polymerization reaction. The oligomers of the present invention are characterized by excellent solubility in common solvents and a melting temperature considerably lower than their cure temperature, thus enabling the oligomers to be formed into cured polymers more slowly and at lower temperatures, all without the evolution of deleterious gases.
A class of relatively low molecular-weight oligomers containing at least one isoimide group and terminal groups capable of undergoing an addition polymerization reaction. The oligomers of the present invention are characterized by excellent solubility in common solvents and a melting temperature considerably lower than their cure temperature, thus enabling the oligomers to be formed into cured polymers more slowly and at lower temperatures, all without the evolution of deleterious gases.
Description
~h~
SP~ClFI~AI`ION
The present invention is directed to Dligomers, and in particular, to a cl~ss of relatively low-molecular weight oligomers which contain at least one isoimide group along with functional groups that enable the oligomers to be cured by addition polymerization.
Polymers formed of polyimides are well known to the art. As is described in U.S. patent ~o. 3,179,634, su,ch polyimides are characterized by repeating units having the formula:
O O
_ - N~ N - R'- _ 11 !1 _ O n where R is a tetravalent aromatic group and R is a divalent aryl group. Such polymers are known to be use~ul in the molding of films, fibers and the like having high tensile strength, good electrical properties and stability with respect to heat and water.
One of the primary drawbacks to polyi~ide polymers of the ,type described above arises ~rom the method by which such polymers are prepared. Generally, the polymers are prepared by a condensation reaction in which a diamine is reacted with a dianhydride to form a corresponding polyamic acid which can then be converted to the corresponding polyimide by heating. As those skilled in the art will appreciate, that condensation reaction is accompanied by the release of water vapor which, when liberated during a molding opera~ion, can cause voids and other defects in molded products, Substantial improvements over polyimide polymers of the type described in the above patent have been achieved as described in U~S. patent Nos. 3,864,309, 3,845,018, 3,879,349, and 3,928,450~
As described in the foregoing patents, it has been discovered that the disadvantages of polyimide oligomers of the type described, and specifically the tendency of the liberated water vapor to cause voids during molding, can be completely eliminated or substantially prevented when a polyimide oligomer is terminated with a acetylenic group capable of undergoing an addition polymerization reaction~ As is described in the foregoing patents, acetylenic-terminated polyimide oligomers can be polymerized, either with or without a catalyst, to form polymers which exhibit an extremely low void content along with high thermal stability characteristics and high structural strength.
While the oli~omers described in the foregoing patents represent a significant advance in the art, they tend to have poor solubility in common lacquer solvents along with relatively high melting points. Thus, at the high processin~ temperatures required, such oligomers cure too rapidly for use in many applications, particularly where the polymer ls used to form a laminate over a large surface area.
~a~
It has now been found that the foregoing disadvantages can he prevented or substantîaLly miniTnizcd where at least some oE the imide Eunctional groups are replaced by a corresponding isoimide functional group. The presence of ~he isoimide group unexpec~edly imp~oves the solubili~y of sucll oligomers in common solvents, and, quite surprisingly, re~ults in a substantial decr~ase in the melting point of the oli~omer. Thus, oligomers containing an isoimide group in accordance with the practice of this invention can be cured at a more controlled rate using a greater variety of common solvents to form cured pol~ners having essentially the same properties and characteristics as ~hose derived from the corresponding imide oligomer.
It is accordingly an object of the present invention to provide oligomers which can be used in producing void-free composite structures having good solubility in common solvents.
It is another object of the present invention to provide oligomers which are capab]e of producing void-free composite structures,by addition polymerization havin~
relatively low melting points, and thus can be cured in a controlled manner.
The concepts of the present invention reside in an oligomer which contains at least one isoimide group along with at least two terminal groups capable of undergoing addition polymerlzation, either alone or in combination with a comonomer. As noted above, the presence of the isoimide ~roup results in a reduction of the melting point of the .
-4- _ o:ligollle~r .In(3 all incre~se in ~hL' sol~ iLy o~ ~,Uetl ol.i)~ n~r in commotl solvents, ~s compared to oligomers pre~are~ from ~he same reagents which contain lmide functional groups.
In their simples~ form, the oligomers of the present invention are prepared by a reaction of an organic carboxylic polyanhydride and a mono-amine c~.bpound containing a functional group capable of undergoing addition polymerization reactions. Thus, the.polyanhydride and the amir,e react to form a corresponding polyamic acid, which is then subjected to the action of a dehydrating agent to convert the polyamic acid to an oligomer containing at least one isoimide group having the structure:
` - N-/ C -O
' ' \C--ll Using benzophenonetetracarboxylic dianhydride and 3-arnino-phenylacetylene as illustrative, the reaction may be illustrated in accordance with the following equation:
O O O
N~
/ +
~lC-C~~ C~ C~ C-_ct~
O O
~s showrl in the ~bove equa~ion, the o].igomer prodllc~d contains an isoimide group in both positions where either an isoimide or imide group could be formed. It should be understood by those skilled ln ~he art, however, that it is not necessary that an isoimide group be ~ormed .in every position where an isoimide group could be Eormed, it being sufficient that the number of isoimide grou.,s present in the oligorner be sufficient to reduce the melting point of the oligomer and increase its solubility in common solvents, as compared to the same oligomer without any isoimide groups, that is, the corresponding imide oligomer.
Oligomers of the foregoing type can thus be homopolymerized, either with or without the use of a catalyst in accordance with the techniques described in U.S.
patent No. 3,845,018 and W.S. patent No. 3,875,349. The greater solubility in common sol~ents and reduced melting point provides a significant advantage in the processability of the oligomer, enabling it to be cured more slowly in a controlled manner as compared to the corresponding oligomers prepared from the same reagents which contain only imide groups.
.
In accor.dance withl another embodiment o:E the invention, use can be made of an aromatic polyamine for reaction with the polyanhydride either before reaction with the monomer or simultaneously therewith. In this embodiment of the invention~ the polyamine serves to link together two or more anhydride groups, the resulting structure containing as ter~inal groups a mono-amine substituted with a functional group capable of undergoing addl~ion polymerization.
{ 1~
Again using benzophenonetetracarboxylic dianhydride and 3-aminophenylacetylene as well as 1,3-di-(3-anlinophenoxy)benæene as illustrative, this latter concept m y be illustrated by way of the following:
SP~ClFI~AI`ION
The present invention is directed to Dligomers, and in particular, to a cl~ss of relatively low-molecular weight oligomers which contain at least one isoimide group along with functional groups that enable the oligomers to be cured by addition polymerization.
Polymers formed of polyimides are well known to the art. As is described in U.S. patent ~o. 3,179,634, su,ch polyimides are characterized by repeating units having the formula:
O O
_ - N~ N - R'- _ 11 !1 _ O n where R is a tetravalent aromatic group and R is a divalent aryl group. Such polymers are known to be use~ul in the molding of films, fibers and the like having high tensile strength, good electrical properties and stability with respect to heat and water.
One of the primary drawbacks to polyi~ide polymers of the ,type described above arises ~rom the method by which such polymers are prepared. Generally, the polymers are prepared by a condensation reaction in which a diamine is reacted with a dianhydride to form a corresponding polyamic acid which can then be converted to the corresponding polyimide by heating. As those skilled in the art will appreciate, that condensation reaction is accompanied by the release of water vapor which, when liberated during a molding opera~ion, can cause voids and other defects in molded products, Substantial improvements over polyimide polymers of the type described in the above patent have been achieved as described in U~S. patent Nos. 3,864,309, 3,845,018, 3,879,349, and 3,928,450~
As described in the foregoing patents, it has been discovered that the disadvantages of polyimide oligomers of the type described, and specifically the tendency of the liberated water vapor to cause voids during molding, can be completely eliminated or substantially prevented when a polyimide oligomer is terminated with a acetylenic group capable of undergoing an addition polymerization reaction~ As is described in the foregoing patents, acetylenic-terminated polyimide oligomers can be polymerized, either with or without a catalyst, to form polymers which exhibit an extremely low void content along with high thermal stability characteristics and high structural strength.
While the oli~omers described in the foregoing patents represent a significant advance in the art, they tend to have poor solubility in common lacquer solvents along with relatively high melting points. Thus, at the high processin~ temperatures required, such oligomers cure too rapidly for use in many applications, particularly where the polymer ls used to form a laminate over a large surface area.
~a~
It has now been found that the foregoing disadvantages can he prevented or substantîaLly miniTnizcd where at least some oE the imide Eunctional groups are replaced by a corresponding isoimide functional group. The presence of ~he isoimide group unexpec~edly imp~oves the solubili~y of sucll oligomers in common solvents, and, quite surprisingly, re~ults in a substantial decr~ase in the melting point of the oli~omer. Thus, oligomers containing an isoimide group in accordance with the practice of this invention can be cured at a more controlled rate using a greater variety of common solvents to form cured pol~ners having essentially the same properties and characteristics as ~hose derived from the corresponding imide oligomer.
It is accordingly an object of the present invention to provide oligomers which can be used in producing void-free composite structures having good solubility in common solvents.
It is another object of the present invention to provide oligomers which are capab]e of producing void-free composite structures,by addition polymerization havin~
relatively low melting points, and thus can be cured in a controlled manner.
The concepts of the present invention reside in an oligomer which contains at least one isoimide group along with at least two terminal groups capable of undergoing addition polymerlzation, either alone or in combination with a comonomer. As noted above, the presence of the isoimide ~roup results in a reduction of the melting point of the .
-4- _ o:ligollle~r .In(3 all incre~se in ~hL' sol~ iLy o~ ~,Uetl ol.i)~ n~r in commotl solvents, ~s compared to oligomers pre~are~ from ~he same reagents which contain lmide functional groups.
In their simples~ form, the oligomers of the present invention are prepared by a reaction of an organic carboxylic polyanhydride and a mono-amine c~.bpound containing a functional group capable of undergoing addition polymerization reactions. Thus, the.polyanhydride and the amir,e react to form a corresponding polyamic acid, which is then subjected to the action of a dehydrating agent to convert the polyamic acid to an oligomer containing at least one isoimide group having the structure:
` - N-/ C -O
' ' \C--ll Using benzophenonetetracarboxylic dianhydride and 3-arnino-phenylacetylene as illustrative, the reaction may be illustrated in accordance with the following equation:
O O O
N~
/ +
~lC-C~~ C~ C~ C-_ct~
O O
~s showrl in the ~bove equa~ion, the o].igomer prodllc~d contains an isoimide group in both positions where either an isoimide or imide group could be formed. It should be understood by those skilled ln ~he art, however, that it is not necessary that an isoimide group be ~ormed .in every position where an isoimide group could be Eormed, it being sufficient that the number of isoimide grou.,s present in the oligorner be sufficient to reduce the melting point of the oligomer and increase its solubility in common solvents, as compared to the same oligomer without any isoimide groups, that is, the corresponding imide oligomer.
Oligomers of the foregoing type can thus be homopolymerized, either with or without the use of a catalyst in accordance with the techniques described in U.S.
patent No. 3,845,018 and W.S. patent No. 3,875,349. The greater solubility in common sol~ents and reduced melting point provides a significant advantage in the processability of the oligomer, enabling it to be cured more slowly in a controlled manner as compared to the corresponding oligomers prepared from the same reagents which contain only imide groups.
.
In accor.dance withl another embodiment o:E the invention, use can be made of an aromatic polyamine for reaction with the polyanhydride either before reaction with the monomer or simultaneously therewith. In this embodiment of the invention~ the polyamine serves to link together two or more anhydride groups, the resulting structure containing as ter~inal groups a mono-amine substituted with a functional group capable of undergoing addl~ion polymerization.
{ 1~
Again using benzophenonetetracarboxylic dianhydride and 3-aminophenylacetylene as well as 1,3-di-(3-anlinophenoxy)benæene as illustrative, this latter concept m y be illustrated by way of the following:
2 0 ~ ~ ~ H2N ~ ~ ~ N~2 ~
il o HC-C ~ Nd ~ C ~ N- ~ O ~ O ~ N-¢C ~ C~
Il 11 11 O O ~O
N ~ C-CH
O
In the above product as structurally shown, all of the potenti.al sites where either an isoimide or imide grQup could be formed havç been arbitr~rily shown in the isoimide form. In actual practice, however, the isoimide groups are formed along with imide groups and interspersed randomly throughout the structure of the oligomer. The position of such isoi~ide groups present in the structure is not of p2rticulsr importance, the important factor being that the isoimide groups be present in the oligomer in sufficient ~ " .
number to reduce the melting point of the oligamer and increase its solubility in common solvents. In general, it is e~lfficient that at least 30% o~ the positions which could be either isoimide or imide groups be isoimide groups.
In accordance with the preferred practice of the invention, a carboxylic acid dianhyride having the formula:
O O
O O
wherein R is a tetravalent o,rganic group containing 2 to 27 carbon atoms is reacted with a functional mono~amine having the formula H2N-R1-X wherein Rl is a divalent organic group containing 1 to 20 carbon atoms and X is a ~unctional group capable of undergoing addition polymerization, either with itself or with a co-monomer, to form the corresponding polyamic acid. l'he resulting polyamic acid is then dçhydrated, preferrably with a dehydrating agent, to form a correspondin~ isoimide and/or isoimide-imide ccntaining oligomer.
The resulting oligomer can be one of two position isomers, either the cis isomer X- Rl N - C / C -N Rl- X
0 ~R /O
Il il i~ O O
or the corre~pollding Lrans i~omer:
X~ R~ N = C C
O R O
C C ~ ~ ~ ~; ~ X
In actual practice, the oligomer is fre~uently a mixture ~f the above two isomers along with smaller amounts of oligomers containing an isoi~ide group and an imide group havin~ the structure:
X~ C
O R N ~R -\ / \ / 1 Il 11 - O O
In addition, t:he ~eaction product may also contain small amounts o~ the corresponding di-imide.
The carboxylic acid dianhydride is one in which ~he ~ group is ~referably an aryl group containg 6 to 18 carbon atoms. Representative o such groups are ttle following:
'~
~ .
-9~ _ ~
~ r Il.
~C~
Il 1l where Y is -C-, -(CH2)X- where x is an integer ~`rom 1 to 5, ' 2 ' (CF2)x-~ -C(5F3)2- where x is as defined above, as well as the following groups:
O R
.' 11 12 - C -N
~ C~O--, ~ si-- .
~3 ~'''''.~ .
, . . .
, -10- .
wherein R2 and R3 are ~ryl (such BS phenyl and substituted derivatives thereof) or alkyl containing 1 to 5 carbon atoms.
Such anhydrides are known to those skilled in the art and are described in U. S. Patent Nos. 3,261,811 and
il o HC-C ~ Nd ~ C ~ N- ~ O ~ O ~ N-¢C ~ C~
Il 11 11 O O ~O
N ~ C-CH
O
In the above product as structurally shown, all of the potenti.al sites where either an isoimide or imide grQup could be formed havç been arbitr~rily shown in the isoimide form. In actual practice, however, the isoimide groups are formed along with imide groups and interspersed randomly throughout the structure of the oligomer. The position of such isoi~ide groups present in the structure is not of p2rticulsr importance, the important factor being that the isoimide groups be present in the oligomer in sufficient ~ " .
number to reduce the melting point of the oligamer and increase its solubility in common solvents. In general, it is e~lfficient that at least 30% o~ the positions which could be either isoimide or imide groups be isoimide groups.
In accordance with the preferred practice of the invention, a carboxylic acid dianhyride having the formula:
O O
O O
wherein R is a tetravalent o,rganic group containing 2 to 27 carbon atoms is reacted with a functional mono~amine having the formula H2N-R1-X wherein Rl is a divalent organic group containing 1 to 20 carbon atoms and X is a ~unctional group capable of undergoing addition polymerization, either with itself or with a co-monomer, to form the corresponding polyamic acid. l'he resulting polyamic acid is then dçhydrated, preferrably with a dehydrating agent, to form a correspondin~ isoimide and/or isoimide-imide ccntaining oligomer.
The resulting oligomer can be one of two position isomers, either the cis isomer X- Rl N - C / C -N Rl- X
0 ~R /O
Il il i~ O O
or the corre~pollding Lrans i~omer:
X~ R~ N = C C
O R O
C C ~ ~ ~ ~; ~ X
In actual practice, the oligomer is fre~uently a mixture ~f the above two isomers along with smaller amounts of oligomers containing an isoi~ide group and an imide group havin~ the structure:
X~ C
O R N ~R -\ / \ / 1 Il 11 - O O
In addition, t:he ~eaction product may also contain small amounts o~ the corresponding di-imide.
The carboxylic acid dianhydride is one in which ~he ~ group is ~referably an aryl group containg 6 to 18 carbon atoms. Representative o such groups are ttle following:
'~
~ .
-9~ _ ~
~ r Il.
~C~
Il 1l where Y is -C-, -(CH2)X- where x is an integer ~`rom 1 to 5, ' 2 ' (CF2)x-~ -C(5F3)2- where x is as defined above, as well as the following groups:
O R
.' 11 12 - C -N
~ C~O--, ~ si-- .
~3 ~'''''.~ .
, . . .
, -10- .
wherein R2 and R3 are ~ryl (such BS phenyl and substituted derivatives thereof) or alkyl containing 1 to 5 carbon atoms.
Such anhydrides are known to those skilled in the art and are described in U. S. Patent Nos. 3,261,811 and
3,345,342. Typical of such anhydrides are:
pyromelli~ic anhydride 3,4,3',4'-benzophenone tetracarboxylic di~nhyride 2,3~6,7 naphthalene tetracarboxylic dianhydride 3,3',4,4'-diphenyl tetracarboxylic dianhydride 1,2,5,6-naphthalene t etracarboxylic dianhyride 2,2',3,3'-diphenyl tetracarboxylic dianhydride 2,2-bi.s(3,4-dîcarboxyphenyl)propane dianhydride bis(3,4-dicarboxvphenyl) sulfone dianydride 3,4,9,10 peryl.ene tetracarboxylic dianhydride bis(3,4-dicarboxyphenyl)ether dianhydride 2,~-dichloronaphthalene-1,4,5,8-tetra-carboxylic dianhydride phenanthrene-1,8,9,1~-tetracarboxylic dianhydrlde 1,1-bis(2,3-di.carboxyphenyl)ethane dianhydride 2,2-bis(3,4-dicarboxyphenyl)hexafluoroiso-propyLidene dianhydride 2,2~bis[4-(3,4-dicarboxyphenoxy)phenyl3 hexafluoropropane dianhydride Other dianhydrides may also be used, including those containin~ heterocyclic rings, such as S-heterocycles, O-heterocycles, N-heterocycles and combinations thereof. For example, use can also be made of pyrazine 2,3,5,6-tetracarboxylic dianhydride or thiophene-2,3,4,5-tetra-carboxylic dianhydride.
As the mono amine reacted with the dianhy~ride, use should be ~ade of a mono-amine which is substituted with a functional group capable of undergoing addition polymerization reactions. Such functional groups are well known to those skLlled in the art. In general, the functional group is one containing carbon-to-carbon unsaturation, usually ethylenic unsaturation or acetylenic unsaturation; it is also possible to~ employ, as the .
. -12- . _ functional ~rOup, a cyano ~roup which c~n be co-polymerized by reaction with, for example, terephthalonitrile-N, N'-dioxides as described in U.S. patent No. 3,864,309 It is preferred that the mono-amine have the formula H2N-Rl~X wherein R1 is a divalent organic group containing l to 20 carbon atoms and X is the functional group. X is preferably selected from the group consisting of -C- CH, -CH= CH2, -CN or the following group:
~ 0- C~ C= CH
R4 is H or -CH3. Representative of suitable a~lines are allyl amine, propargyl amine, 3-aminophenyl acetylene, 3-(3-aminophenoxy)phenyl acetylene, 3-aminostyrene, 3-amino-,
pyromelli~ic anhydride 3,4,3',4'-benzophenone tetracarboxylic di~nhyride 2,3~6,7 naphthalene tetracarboxylic dianhydride 3,3',4,4'-diphenyl tetracarboxylic dianhydride 1,2,5,6-naphthalene t etracarboxylic dianhyride 2,2',3,3'-diphenyl tetracarboxylic dianhydride 2,2-bi.s(3,4-dîcarboxyphenyl)propane dianhydride bis(3,4-dicarboxvphenyl) sulfone dianydride 3,4,9,10 peryl.ene tetracarboxylic dianhydride bis(3,4-dicarboxyphenyl)ether dianhydride 2,~-dichloronaphthalene-1,4,5,8-tetra-carboxylic dianhydride phenanthrene-1,8,9,1~-tetracarboxylic dianhydrlde 1,1-bis(2,3-di.carboxyphenyl)ethane dianhydride 2,2-bis(3,4-dicarboxyphenyl)hexafluoroiso-propyLidene dianhydride 2,2~bis[4-(3,4-dicarboxyphenoxy)phenyl3 hexafluoropropane dianhydride Other dianhydrides may also be used, including those containin~ heterocyclic rings, such as S-heterocycles, O-heterocycles, N-heterocycles and combinations thereof. For example, use can also be made of pyrazine 2,3,5,6-tetracarboxylic dianhydride or thiophene-2,3,4,5-tetra-carboxylic dianhydride.
As the mono amine reacted with the dianhy~ride, use should be ~ade of a mono-amine which is substituted with a functional group capable of undergoing addition polymerization reactions. Such functional groups are well known to those skLlled in the art. In general, the functional group is one containing carbon-to-carbon unsaturation, usually ethylenic unsaturation or acetylenic unsaturation; it is also possible to~ employ, as the .
. -12- . _ functional ~rOup, a cyano ~roup which c~n be co-polymerized by reaction with, for example, terephthalonitrile-N, N'-dioxides as described in U.S. patent No. 3,864,309 It is preferred that the mono-amine have the formula H2N-Rl~X wherein R1 is a divalent organic group containing l to 20 carbon atoms and X is the functional group. X is preferably selected from the group consisting of -C- CH, -CH= CH2, -CN or the following group:
~ 0- C~ C= CH
R4 is H or -CH3. Representative of suitable a~lines are allyl amine, propargyl amine, 3-aminophenyl acetylene, 3-(3-aminophenoxy)phenyl acetylene, 3-aminostyrene, 3-amino-,
-4-bromostyrene, 3-aminobenzonitrile,-4-aminophenyl acrylate 3-aminobenzy~ methacrylate, 4-aminobenzylmethacrylate, etc.
,~r~ .
In carrying out the reaction between ~he di~nhydride and the mono~amine as described above, conventional reaction conditions typically used in ~he preparation of isoimides, such as those described in U.S. Patent No. 3,345,342, may be used. In general, the reactions carried out in accordance with the practice of this invention employ at least one mole of the mono-amine per mole of the dianhydride. Preferably, the mono-amine is reacted with the dianhydride in a molar ratio ranging from about 1.2 to ~bout 2.5 mole6 of mono-amine per mole of dianhydride, although it will be understood that greater amounts of the mono-amine may be used. The reaction is preferably carried out in the presence of a solvent, such as an aliphatic ether solvent, although other inert or reactive solvents may be used.
The temperature ~t which the reaction is carried out is not critical, and depends, to some degree, on the nature of the dianhydride being used and the particular amine being used. Best results are usually achieved when the reaction temperature is maintained below 100 C. Higher temperatures can cause the amic acid to cyclize to the corresponding imide.
After the reaction has been completed, the product is in the form of a polyamic acid which can be converted to the corresponding isoimidè through the use of a dehydrating a~ent. Such dehydrating agents, and their use in forming isoimides, are well known to those skilled in the art and are described in U.S. patent No. 3,261,811.
The dehydrating agent preferred for use in the practice of the present invention is trifluoracetic anhydride. Other dehydrating agents include N, N-disubstituted carbodiimide, such as N, I~-dicyclohexyl carbodiimide dissolved in N, N-dimethyl acetamide and ketene.
It is generally preferable to carry out the dehydration reaction at a relatively low ~emperature, usually below 60C.
As noted above, another embodiment of the invention includes the use of an aromatic poly~mine which is reacted with the dianhydride, preerably prior to reaction with the mono-amine. The polyamine, ,and preferably a dia~ine, serves to link together two or more moles of the dianhydride, le~ving terminal anhydride groups capable of reaction with the mono-amine. In general, use is made of at least one mole,of the polyamine for each mole of the dianhydride and at least one mole of the mono-amine per mole of the,dianhydride.
The diamine is preferably a compound having the formula:
wherein R5 is a divalent aromatic group, preferably containing 6 to 30 carbon atoms. Preferred are arylene, arylene ether, and arylene thioether groups. Representative of such groups include a phenylene group or a naphthylene ~roup 'as well as a group having the formula:
O ~~Y~
wherein Y is C-, -(CH23 - where x is an integer from 1 ' 2 ' (~F2)x-' -C(cF3)2- where x is as defined above, and the following groups:
C - N -o Il C--O
--si--wherein R6 and R7 are aryl (such as phenyl and substituted derivatives thereof) or alkyl containing 1 to 5 carbon atoms.
In addition, R5 can also be a group of the formula:
~Y-~ LYI~3~~Y~~
wherein y, yt and Y" are each the same or different and are selected from the same group as Y as defined above. As will be appreciated by those skilled in the art, the aryl groups set forth above as being part of the R5 group can also be substituted with, for example, one or more halogen atoms, lower allcyl groups and/or lower alkoxy groups.
Such diamines are well known to those skilled in the art and are described in detail in ~.S. patent Nos.
3,261,811 and 3,345,342. Typical of such amines 'are:
meta-phenylenediamine, 2,2-bis(4-aminophenyl)propane, ~ .
4, 4 ' -d i~m inod i phenyl methane, 4, 4' -diaminodiphenyl sulfide, 4, 4 I _d iam inod iphenyl sul fone, 3,3'-diaminodiphenyl sulione, 2,6-diaminopyridine, bis (4-aminophenyl)diethylsilane, bis-(3-aminophenyl)ethyl pho~phine oxide, 1,3-di(3~aminophenoxy)benzene 2,2-di(3 aminophenyl)hexafluoropropane 2,2-di(4-aminophenyl)hexafluoropropane Without limiting the invention as to theory, it is believed that the diamîne reacts with the anhydride to form the corresponding polyamic acid having free acid anhydride groups available for reaction with the mono-amine. It is generally preferred that the carbo ylic dianhydride be as pure as possible7 and preferably free of the corresponding carboxylic acid. Without limiti~g the invention as to theory, it is believed that carboxylic acid impurities in the dianhydride results in the formation of amine salts which catalyze the conversion of isoimide groups to the corresponding irnide groups.
After the reaction between the dianhydride and the diamine has been completed, it is generally preferable to introduce the mono-amine for reaction with those free terminal acid anhydride groups to form an oligomer end-blocked with the mono-amine.
That reaction product- is then subjected to dehydration to convert the polyamic acid to the corresponding isoimide.
That overall reaction, again without limiting the present invention as to theory, m~y be illu-strated diagramatically as follows:
C~l zc~l l .
ll i ~
c~ o ~o~
~ =o z z ~ x \ /
~ z~ o p~
' ~ 'I / \ .
o~ = o c~
o--c~,, ~c,,=O ! . ~ ~
o~ ~ o P~ o \ / , ` I \ /
~ \ ~; O r \ / ' ' \ ~ 11 O~
O _~) \ V__O r~~
O
.11~ .
As shown in the preceding equation, the dianhydride reacts first with ~.he diamine to ~orm the corresponding polyamic acid, with the number of ~oles of diamine entering into the reaction depending on the proportion of the reactants. In the equation shown, n is O
or an integer ranging from 1 to about 15 or higher, depending on the reactant proportions. That variable is generally referred ~o as the de~ree of polymerization of the oligomer commonly denoted DP. When n is 0, the oligomer contains a single mole of diamine for each two moles of dianhydride presentS and thus the degree of polymerization is 1~ ~hen n equals 1, and thus 2 moles of diamine are present for each 3 moles of dianhydride, the degree of pol~merization is 2, and so on.
As will be appreciated by those skilled in the art, the predominant degree of polymerization can be controlled by controlling the proportions of the reactant.
Nonetheless, there is always a tendency for the reaction to form mixtures. F'or example, in the preparation of an oligomer of the type shown above having a DP of 1 (n 0), the idealized proportions of a reactant necessary to produce a DP of 1 re~uires the reaction of 1 mole of diamine with 2 moles of dian~lydride and 2 moles of mono-amine. When those proportions are used, the reaction produced contains predominantly a product in which the DP is 1, but also contains in decreasing proportion, oligomers in which the DP
is 2, 3, 4 and so on as well as small amounts of oligomers formed by the reaction of 1 mole of the dianhydride and 2 moles of the mono-a~ine -- thus containing no diamine a~
all.
~ 1 9~
In general, when it is desired to produce an oligomer havin~ a DP of 1, the reactants are used in mole proportions o~ .5 to 1.5 moles of the diamine, 1.5 to 2.5 moles of the dianhydride, and 1.5 to 2.5 moles of the mono-amine~ When an oligomer having a DP of 2 is desired, the molar propor~ions range from 1.5 to 2.5 moles of the diamine, 2.5 to 3.5 moles of the dianhydride, and 1.5 to 2~5 moles of the mono-amine. Similarly, when a DP 3 oligomer is desired, the molar pxoportions are about 2.5 to 3.5 moles of the diamine, 3.5 to 4.5 moles of the dianhydride, and 1.5 to 2.5 moles of the mono amine.
The above structure is, as those skilled in the art will appreciate, an idealized structure, depicting as it does all of the positions where an isoimide or imide group could be formed as isoimide groups. As noted above, such an idealized reaction product is difficult, i~ not imposs~ble, to achieve because of the tendency to form imide groups along with isomide groups. Of course, there is also the tendency of the reaction to produce both cis and trans isomers as well as mixtures thereof. However, the positions at which the isoimide groups form are not criticial to the practice of the invention; the im~ortant feature is that the isoimide groups be present in a su~ficient number so as to reduce the melting point of the resulting oligomer and increase its solubilit~ in common lacquer solvents such as dialkyl ketones, tetrahydrofuran. While the proportion of isoimide groups necessary to reach that result varies somewhat with the nature of the reactants used in preparing the oligomers, it has ~een found that at least 30% isoimide groups serve to decrease the melting point and increase the ~a~ 4 solubility of the resulting oligomers.
Preferred oligomers, in accordance with this embodiment, are prepared from an dianhydride such as 3,4-3',4'-benzophenonetetracarboxylic dianhydride, an amine-terminated aryl polye~her, and an amino phenylacetylene mono-amine.
In accordance with yet another embodiment of the presen~ invention, it is also possible, and some~imes desirable, to employ reactants in which the end-capping group containing a polymerizable functional group also contains an anhydride group. In accordance with this embodiment of the invention, a dianhydride having the formula:
O O
Il 11 O~C~C~o Il 11 O O
is reacted with a diamine having the formula:
to form an amine terminated polyamic acid which is then reacted with an anhydride having the formula:
O~C~R
~ C~
wherein R7 is a radical containing an alkenylene group or a trivalent organic group, which is preferably an aryl group, having substituted thereon a function group capable of under-going addition polymerization reactions as described above.
` - 21- .
l`he resultin~ product is then subjected to a d~hyaration reaction to convert at least some o~ the amic acid ~roups to isoi~ide groups. This concep'.-, wi~hout limiting the invention as to theory, may 1~ illustrated by the ~ollowin~ equation:
~.~
, J ~ f~
/ \ ~ o o =~ o ~
\ / . l o ~ r~
z ~ p;
, _ .. I _ / ~
I ~ 11\ o/
~ ~ z +
o ~ c~ t~ = o u~ l o=u t~--o 11~\
x ~ ~=o ~; ~o l ~ /
z c~ o \o/
+ . o=l I o o_t~ V~O
o~ . Z
V V--O
/ ~ ~ \ /
o o :~
.,~ .
In the foregoing equation, m denotes the degree of polymerization, with m~l denoting a DP of 1, and so on such that m is 1 to about 15 or higher, depending on the reactant proportions. As with the preceding equations, the products shown above are illustrated in an idealized form, with all of the sites where either imide or isoimide groups could be formed taking the form of an isoimide group. In actual fact, again, some of those groups are in the imide form.
As the functional anhydride, use can be made of a variety of mono-anhydrides f ~uch as the ~ollowing:
4-ethynyl-phthalic anhydride, 4-vinyl-phthalic anhydride 4-cyano-phthalic anhydride Maleic anhydride Bicyclo[2,2,1]hept-2-ene-5,6-dicarboxylic anhydride The use of maleic anhydride produces an oligomer containing the following idealized structure:
~ ; - N J C /C - N - R5- - N j C~ ~H
H~C~c / C R /0 ~ c~c~
Il . 11 11 11 O O O _ m O
while the use of a bicycloheptene anhydride of the ~ormula:
o ~C ~l Rlo wllerein R8, Rg and Rl~ are each H or lower alkyl yield~
an ideallzed structure as follows:
~ ~ 5 ~ O/c ~ C\o N - R5 - N -~C
Rlo o 8 o 9 Rlo The oligomers of the present invention are used in th~ same manner as those described in U;S. Patent Nos.
3,864,309, 3,845,018, 3,~79,349 and 3,928,45G to produce cured resins having high strength and ~emperature characteristics as well a~ low void contents. Without limiting the present invention as to the theory, it is believed that the isoimide groups present in the ol igomers of this invention are, w~len subjected to elevated te~per~ture during cure, convert ~o the corresponding imide.
Thus, the properties and physical chara~teristics of cured resins made from the oli~omers of the present invention are virtually the sal~e as those described in the foregoing patents.
Having described the basic concepts o the present invention, reference is now made to t~le following ex~mples, which are provided by way of illustration, and not ~y way of limit~tion, of the practice of the invention in making the oli~umers and using the~ in the form of cured resins.
,,~
,J
-25- ~
l:xample 1 This example illustrates the preparation of a bis-isoimide from a mono-amine and a dianhydride.
Benzophenonetetracarboxylic dianhydride (lS~0 ~, grams; 0.0466 mole) in 250 ml of tetrahydre~uran at 60-~5C
' was reacted with 3-aminophenylacetylene (iO.9 grams, 0.0932 mole) for 1 hour. The solution was cooled and treated with .
trifluoroacetic anhydride (60 grams~ maintaining the temperature at 10-1~C. The reaction mixture was kept at 20-25C for 18 hours and the bis-isoimide recovered by precipitation in hexane and then dried in vacuum. The bis-isoimide was mostly isoimide (about 90%); the remainder, imide as determined by infrared spectroscopy. A yield of 17 grams was isolated, melting at 115-120C.
Example 2 This example illustrates the preparation of an acetylene-terminated isoimide oli~omer having a degree of polymerization of 1.
A three-necked one liter round bottom was fitted with a heating mantle, Tru-bore stirrer, reflux condenser, thermometer and addition funnel. The top of the reflux condenser was protected from atmospheric moisture with a drying ~ube.
The ~lask was charged with benzophenonetetracarboxylic dianhyd~ide (30 grams, 0.0~32 mole) and dry tetrahydrofuran -26- ~
(30~ ml). l~le solution was heate~ to a gencle reflux and a sol~ltion of 1,3 di(3-an)ino~herloxy~ellzene (13.9 grams, .0476 mole) in dry tetrdhydrofuran (1~5 ml) was added dropwi~e over a 30-40 minute period. Then the reaction mixture was stirred for an additional 30 minutes and a solution of 3-àminophenylacetylene (10.9 grams, 0.0932 IDole) in dry tetrahydrofuran ~30 ml) addedO
' ' .
After the addition~ the solution was heated at a ;,! ~entle reflux for an additional 30 minutes, cooled to - ambient and trifluoroace~ic anhydride (110 grams~ added dropwise, maintaining the temperature at ambient by means of an ice bath. The reaction mixture was maintained at room temperature for approximately 1~ hours. The oligomer was ~l then precipitated by pouring the reaction mixture into 2300 `
ml of hexarles and the oli~omer washed with fresh hexane.
'I
.
The product was dried in the rotary film evaporator at 85~ for several hours. The bright yellow oligomer weighed 52 ~rams. The product showed a characteristic infrared isoimide absorption at 1805 cm with only a very small amount of imide at 178~ cm . The oligomer mel.ts at 150-155C.
Exam~e 3 This example illustrates the preparation of an oli~orr.er having a de~ree of pol~rnerization of 3.
Io a solution of benzophenonetetracarboxylic c anhydri~e (71.4 ~rams, 0.2217 mole) in dioxane (700 ~1) at : -27-7~oC, a solu~iorl of 1,3-di(3-a~ opl-lenoxy) benzene (48.5 grams ! 0.1661 mole) in dloxane (400 ml) was added dropwise over a one hour period. The solution was stirred for 30 minutes and 3-aminophenylac~tylene ~13.0 grams, 0.111 mole) added all at once. After stirring at 65-70OC for 2 hours, trifluoroacetic anhydride (275 grams) was added over a 15 minute period. '~le mixture was heated for ln additional hour, cooled and the yellow oli~omer (135 grams) isolated by precipitation in hexane.
Example 4 This example illustrates the preparation of an oligomer havi.ng a degree of polymerization of ten.
A three-necked, l-liter, round-bottomed flask was fitted with a heating mantle, Tru-bore stirrer, therrnometer, reflux ~ondenser and addition funnel. The opening of the reflux condenser was protected with a Drierite filled tube.
The flask was charged with benzophenonetetracarboxylic dianhydride (28.1 grams, 0.0873 mole~ and dry tetrahydrofuran (300 ml). The mixture was heated to just below re~ x and a solution of 1,3-di(3-aminophenoxy) ~enzene (23.2 grams, 0.0795 mole) in dry tetrahydro~uran (250 ml) was added drop-wise over a l-hour period. Then a solution of 3-aminophenyl-acetylene (l.S6 grams, 0.01585 mole) in a dry tetrahydrofuran (10 ml) was added. After the addition, the solut;on was heated at reflux for another hour, coo]ed to 10C, and tri~luoroacetic anhydride (120 grams) added dropwise with good stirring.
.
l`he reac~ion Inixture was kep~ ak ambient temperat-lre for approxir,ately 18 hours . The insoluble taLfy-like product was triturated with approximately 125 ml of dry tetrahydrofuran to dissolve the product. This was poured into 1 liter of hexanes which precipitated the oligomer.
The rest of the reaction mixture was poured ;nto 1 liter of hexanes and the precipitated product filter d, washed with hexane, and dried in the rotary film vaporator under vacuurn at ~0C. The product weighed 49 grams.
Films cast from a dimethylformamide solution, and cured at 700 DF for one hour, yielded tensile strengths of 14,000 psi at room temperature and elongations of 3%.
Example 5 . .
This example illustrates the preparation of another oligomer having a DP of 1.
To a solution of benzophenonetetracarboxylic dianhydride (48.3 grams, q.150 mole) in tetrahydrofuran (500 ml) at 60-65C, a solution of 4,4'-oxydianiline (15.0 grams, 0.075 mole) in tetr,ahydrofuran (200 ml) was adcJed dropwise over a 35 minute period. After the addition, the reaction mixture was heated at reflux ~or another 30 minutes and a solution of 3-aminophenylacetylene (17.6 grams, 0,1630 mole) in tetrahydrofuran (100 ml) was added, the mixture was heated at reflux~for 3~ more rninutes and cooled to about 5 to 10C.
Then trifluoroacetic anhydride (200 ~rams) was added and the mixture stirred for about ].6-18 ~lours. Ihe yellow product (60 ~rams) was isolated by precipitation in hexane.
i lnfrared spectroscopy sllowed tl-at the product had Lhe ch~lracteristic isoimide peak at l~OS crll and only very ~mall amount of imide at 1780 c~ . It was soluble in acetone, tetrahydrofuran and a number of other solvents.
It Inélted at 160-165C and cured readily a~ove its melting point. A ~`g greater than 40~C was obtained ~or this product.
Exarnple_6 ! This exa~ple illustrates the preparation of a ~aleic anhydride capped oligomer having a DP of 1.
~ .
To a solution of 1,3-di(3-aminophenoxy3 benzelle (40.0 grams, 0.1342 mole) in tetrah~drofuran (300 ml) at 60-65C, ~ warm solution of ben~ophenone~etrac~rboxylic dianhydride ~21.h grams, 0.06711 mole) in tetrahydrofuran (525 ml) WAS added dropwise over a 45 minute period. After I the addition the solution was heated for an additional 45 inutes and a solution of Inaleic anhydride (13.2 grams, 0.1342 mole) in tetra~ydrofuran (100 ml) was addedg the solution heated for 45 minutes more, cooled to 10C .and trifluoroacetic anhydride (200 grams) added dropwise. A~ter stirring at ~0-25C ~or 18 hours the product (57 grams) was isolated by precipitation in hexane and vacuur~ drying. This oli~omer had appreciable solubility in A nu~nber o solvents, (acetone, ~etrahydrofuran, ~lycolic ethers) and rnelted 155-C.
':
-3~- _ Each of the oligomers prepared in Examples 1-6 was compared to the corresponding oligomer which was in the imide form, as opposed to the isoimide form. In each case, the is~imide oligomers o~ this invention were soluble in ketones, alcohols, amides, glycol ethers and cycloaliphatic ethers (all of which are common lacquer sol~ents) whereas the corresponding imide oligomers were insoluble in such solvants, being soluble only in N-methylp~rrolidinone and N,N-dimethylformamide.
In addition, the melting points of the ~arious oligomers were compared, as well as, in some instances, the gel time. The results of khese comparisons is set forth in the following table:
Table 1 .
FormComposition Melting Point Gel Time Min (TC) . ~
Isoimide 115-120C
~:xample 1 Imide form Intractable 0 Isoimide 145-150C 15-30 (191C) Example 2 Imide form > 200C 3 (250C) _ _ . . . .
Isoimide 150-155C 15-30 (191C) Example 3 Imide form > 200C 3-5 (250C) .. . . . .. ... .. _ . ... _ . ._--Isoimide 160-165C
Example 4 Imide foxm ~ 200C
Isoimide 155-160C
Example 5 Imide form ~ 230C
.
Isoimide 150-160C
Example 6 Imide form --.. . .
~ ~ 31 -ln each instance, the lsoirilide form oE ~he oligomer embodying the concepts of this invention had a meltin~ point considerably lower than ~he corr~sponding imide form.
le 7 ~; :
` This example illustrates the preparation of a cyano-terminated isoimide having a DP of 1.
., :
~ . Using the procedure described in Example 2, 1 mole .1 of 3,31,4,4~ diphenyltetracarboxylic dianhydride is reacted with 1/2 mole of bis(4 aminophenyl)dimethyl silane, and then the product of the reaction is reacted with 1 mole of ~'' ` .
3-aminobenzonitrile.
The product is then dehydrated, and analyzed for infrared isoimide absorption. The resulting isoimide oligomer can be copolymerized with terephthalonitrile-N,N'-dioxide to form a copolymer in accordance with the teachings of U.S. Patent No. 3,864,309.
EXam~ 8 This example illustrates the preparation of a bis-isoimide prepared from pyromellitic anhydride and 3-aminophenyl methacrylate.
Using the procedure illustrated in Example 1, 1 mole of pyromellitic anhydride is reacted with 2 moles of 3-aminophenyl methacrylîc acid. After the reaction is completed, - : 32-the reactiorl mix~ure 1s cooled alld ~lehydrcltecl usin~, ket~lle as a dehydrating agerl~, .
Infrared absorption demonstrates the presence of isoimide ~roups.
~1 Example 9 ., l Ihis example illustrates the preparation of a bis-isoimide form allylamine and 2,3,6,7-naphthalenetetracarboxylic dianhydride.
.
Using the procedure described in Example 1, the above reactants are refluxed to form the corresponding ~ polyamic acid, and then the reaction product is dehydrated ,J, with trifluoroacetic anhydride.
Infrared absorption indicates the presence of iso-j imide groups.
i~
i ~xample 10 .
This example illustrates the preparation of a film Erom an acetylene-terminated isoimide having a degree of polymerization of ten (from Example 4).
A 20 weight percent solids content of the oligomer in solvents such as methyl ethylketone, N,N-dimethylformamide~
N,N-dimethylacetamide or N-methylpyrrolidinone is cast on a ~lass plate with a doctor blade to yield a 1-2 mil ~et filn?.
The plate with the film is prebaked at 150~F for l hour and .
-33- ~
.. . . . . .. ... . .. . .
chen cured stepwi~e ~lsing 40()~ for 15 minuLes; 500~ ior lS
~inutes, 600F for 15 minutes and fiTlally at 700F ~or l hour in an air~circulatin& oven.
I
The film made in this way was found to have a I tensile strength of 14,000 psi and an elongation of 3 percent. A Tg as deter~ined using l`l~lA was ound ~o be 230C.
xample ll This example illustrates the preparation of a graphite fiber composite using standard-vacuum bag technolo~y.
An acetylene-terminated isoimide having a degree of polymerization of one (from Example 2) was dissolved in a 95:5 percent by volume mixture of methylethylketone: N-- methylpyrrolidinone to a solids content. of 25 percent by weight. The lacquer was brushed on unidirectional hTS-2 fibers wound on a 5" x 6" aluminum tool. The prepreg was air dried until the methylethyl ketone has evaporated. This was repeated until the wet resin content was brought up to about 40-45 percent.
The dried graphite prepreg was laid up into 8 ply cvnstruction in the followin~ orientat~on: 0, 90, 90, 0, 0, 90, 90, 0. ~hen required for additional tack, the preprey, was mlst coated with N-methylpyrrolidinone. The construction was placed into a vacuum oven with 2 plles of air weave and 1 ply of TX 1040 on the outer prepreg surfaces and dried at 125F ~or 4 hours. The prepreg was taken ou~
of the oven ilncl reba~,ged as described above and placed into an autoclave. The initial pressure was 30 psi and 25 inches of mercury vacuum and the ternperature raised to 375F in 30 minutes. ~`hen the pressure increased to 150 psi with a 30 inch mercury vacuum and held for 2 hours. The part was cooled to 150I~ under air and vacuum pressure. The autoclave is then vented, the part removed ~nd the formed part postcured ln a standard air circulating oven. A dense non-porous laminate was obtained.
Example 12 . , , This example illustrates the preparation of a bis-isoimide prepared from pyromellitic anhydride and propargyl ~,, amlne.
.i, .
::~! ' Using the procedure described in Example l, one -mole of pyrornellitic anhydride in tetrahydrofuran is reacted with two moles of propargyl amine. The reaction mixture was cooled and then treated wlth a dehydrating agent while maintained at a temperature of about 20C. The product is determined to be predominantly a bis-isoimide having the formula:
HC - C - CH2 ~ ~ C~ N - CH2 - C~CH
':1 ` O . o ' l ~ .
as well as the position isomer thereof~
., .
-35~
Exarn~le 13 This example illustrates the preparation of a bis-isoimide l~repared by reaction of 3,3',4,4'-diphenyltetra-carboxylic dianhydride and 3-aminobenzonitrile.
Using the procedure illustrated n E~ample l, one mole of dianhydride is reacted with two moles of 3-amino-benzonitrile. After reaction and subsequent dehydration, there is isolated from the reaction a bis~isoimide in the form of a mixture oi the cis and trans isomers, the trans isomer having the formula:
O
~ ~ ~ ~ C\- N ~ CN
N ~ N = \C ~ C/
Example 14 This example illustra~es the preparation of a bis-isoimide from reaction of bis(3,4,-dicarboxylicphenyl)sulfone ; dianhydride with 3-(3-aminophenoxy)phenyl acety]elle.
.
Using the procedu~^e illustrated in Example 1l one mole of dianhydride is reacted with two moles of the mono-amine. A~ter the reaction is completed, the product is dehydrated with trifluoroacetic anhydride to form a ~ixture of cis and trans isomers of an isoin~ide, the cis isolner having the followi~g structure:
~ -36-.... . . . ... .. . . .... . .... .. .
~C _ (~ O~--N- C~S~ ~ c (~N
Ii 11 O O
Example 15 l~is example illustrates the prep ration of bis-isoimide having a DP of lo Using the procedure described in Example 2, two moles of 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride are reacted with 1 mole of 1,3-di(3-aminophenoxy)benzene, and then the product of the reaction is reacted with 3-amino-benzonitrile. After the polyamic acid is formed~ the product o the reaction is dehydrated with trifluoroacetic anhydride to for~l an isoimide-containing oligo~er.
Example 16 This example illustrates the preparation of an oligomer having a DP of 1.
Using the procedure described in Example 2 two uoles of pyromellitic anhydride are reacted with one mole of oxydianiline, and then two moles of 3-aminophenyl acetylene are added to the reaction. The reaction mixture is then cooled and dehydrated with trifluoroacetic anhydride to form the corresponding isoimide-containing oligomer. It has been determined that yield of isoi~ide groups, to the exclusion of imide groups, is increased when the anhydride is purified ~to rel~ove all carboxylic acid-containing impurities.
-37- _ :
~xam~)le 17 This example illus~rates the preparation of an isoimide-containing oligomer having a DP of 1.
Using the procedure described in Example 2, two moles of 2,2-bis(3,4-dicarboxyphenyl)hexafl oroisopropylidine dianhydride are reacted with one mole of ~,6-diaminopyridine.
The product is then reacted with 3-(3-aminophenoxy)phenyl acetylene. The reaction mixture is cooled and dehydrated to form ~he corresponding isoimide-cont~ining oligomer.
Example 18 .
This example illustrates the preparation of an ..
isoimide-containing oligomer having a DP of I similar to the oligomer of Example 1 but containing very little imide isomer.
A 1 liter, three-necked round bottom flask fitted with a Tru-bore stirrer, thermometer and dropping funnel was charged with carboxylic acid free benzophenone-tetracarboxylic dianhydride (45 grams, 0.1398 mole) and dry tetrahydrofuran (400 ml). To the slurry, at 27C (aMbient), a solution of 1,3-di(3-aminophenoxy)benzene (20,40 ~ran~s, 0.06988 mole) in dry tetrahydrofllran (200 ml) was added drop~ise with good stirring. Shortly after starting the addition, all the solids went into solution. Then to the light amber, clear solution, a solution of 3-aminophenylacetylene (16~35 grams, 0.1398 mole) in dry tetrahydrofuran (100 ml) was added.
The solu~ion was allowed to stand at ambient -3~- -t~ perat~r~ ~or approximately 16 hours anc] th~n cooled to -10~. Tri~luoroace~ic anhydride (68.5 gr~rn9, 0.326 mole) was added dropwise carefully maintaining the temperature below 0C. The addition took approximately 10 minutes.
After the addition, the solution was allowed to stand ior 105 minutes and the oligomer precipitated by pouring the solution into a large quantity of hexane (4 llters). The oligomer was filtered and washed with fre~h hexane and dried under vacuum, starting first at ambient temperature and finally increasing the temperature to 90~C.
The oligomer (72 grams) was mostly isoimide as evidenced by the presence of the 1805 cm l peak in an infrared spectrogram and no peak at 1780 cm (imide).
It will be understood that vàrious changes and modifications can be made in the details of procedure, formulation and use without departing from the spirit of the invention, especially as defined in the ~ollowing claims.
,~r~ .
In carrying out the reaction between ~he di~nhydride and the mono~amine as described above, conventional reaction conditions typically used in ~he preparation of isoimides, such as those described in U.S. Patent No. 3,345,342, may be used. In general, the reactions carried out in accordance with the practice of this invention employ at least one mole of the mono-amine per mole of the dianhydride. Preferably, the mono-amine is reacted with the dianhydride in a molar ratio ranging from about 1.2 to ~bout 2.5 mole6 of mono-amine per mole of dianhydride, although it will be understood that greater amounts of the mono-amine may be used. The reaction is preferably carried out in the presence of a solvent, such as an aliphatic ether solvent, although other inert or reactive solvents may be used.
The temperature ~t which the reaction is carried out is not critical, and depends, to some degree, on the nature of the dianhydride being used and the particular amine being used. Best results are usually achieved when the reaction temperature is maintained below 100 C. Higher temperatures can cause the amic acid to cyclize to the corresponding imide.
After the reaction has been completed, the product is in the form of a polyamic acid which can be converted to the corresponding isoimidè through the use of a dehydrating a~ent. Such dehydrating agents, and their use in forming isoimides, are well known to those skilled in the art and are described in U.S. patent No. 3,261,811.
The dehydrating agent preferred for use in the practice of the present invention is trifluoracetic anhydride. Other dehydrating agents include N, N-disubstituted carbodiimide, such as N, I~-dicyclohexyl carbodiimide dissolved in N, N-dimethyl acetamide and ketene.
It is generally preferable to carry out the dehydration reaction at a relatively low ~emperature, usually below 60C.
As noted above, another embodiment of the invention includes the use of an aromatic poly~mine which is reacted with the dianhydride, preerably prior to reaction with the mono-amine. The polyamine, ,and preferably a dia~ine, serves to link together two or more moles of the dianhydride, le~ving terminal anhydride groups capable of reaction with the mono-amine. In general, use is made of at least one mole,of the polyamine for each mole of the dianhydride and at least one mole of the mono-amine per mole of the,dianhydride.
The diamine is preferably a compound having the formula:
wherein R5 is a divalent aromatic group, preferably containing 6 to 30 carbon atoms. Preferred are arylene, arylene ether, and arylene thioether groups. Representative of such groups include a phenylene group or a naphthylene ~roup 'as well as a group having the formula:
O ~~Y~
wherein Y is C-, -(CH23 - where x is an integer from 1 ' 2 ' (~F2)x-' -C(cF3)2- where x is as defined above, and the following groups:
C - N -o Il C--O
--si--wherein R6 and R7 are aryl (such as phenyl and substituted derivatives thereof) or alkyl containing 1 to 5 carbon atoms.
In addition, R5 can also be a group of the formula:
~Y-~ LYI~3~~Y~~
wherein y, yt and Y" are each the same or different and are selected from the same group as Y as defined above. As will be appreciated by those skilled in the art, the aryl groups set forth above as being part of the R5 group can also be substituted with, for example, one or more halogen atoms, lower allcyl groups and/or lower alkoxy groups.
Such diamines are well known to those skilled in the art and are described in detail in ~.S. patent Nos.
3,261,811 and 3,345,342. Typical of such amines 'are:
meta-phenylenediamine, 2,2-bis(4-aminophenyl)propane, ~ .
4, 4 ' -d i~m inod i phenyl methane, 4, 4' -diaminodiphenyl sulfide, 4, 4 I _d iam inod iphenyl sul fone, 3,3'-diaminodiphenyl sulione, 2,6-diaminopyridine, bis (4-aminophenyl)diethylsilane, bis-(3-aminophenyl)ethyl pho~phine oxide, 1,3-di(3~aminophenoxy)benzene 2,2-di(3 aminophenyl)hexafluoropropane 2,2-di(4-aminophenyl)hexafluoropropane Without limiting the invention as to theory, it is believed that the diamîne reacts with the anhydride to form the corresponding polyamic acid having free acid anhydride groups available for reaction with the mono-amine. It is generally preferred that the carbo ylic dianhydride be as pure as possible7 and preferably free of the corresponding carboxylic acid. Without limiti~g the invention as to theory, it is believed that carboxylic acid impurities in the dianhydride results in the formation of amine salts which catalyze the conversion of isoimide groups to the corresponding irnide groups.
After the reaction between the dianhydride and the diamine has been completed, it is generally preferable to introduce the mono-amine for reaction with those free terminal acid anhydride groups to form an oligomer end-blocked with the mono-amine.
That reaction product- is then subjected to dehydration to convert the polyamic acid to the corresponding isoimide.
That overall reaction, again without limiting the present invention as to theory, m~y be illu-strated diagramatically as follows:
C~l zc~l l .
ll i ~
c~ o ~o~
~ =o z z ~ x \ /
~ z~ o p~
' ~ 'I / \ .
o~ = o c~
o--c~,, ~c,,=O ! . ~ ~
o~ ~ o P~ o \ / , ` I \ /
~ \ ~; O r \ / ' ' \ ~ 11 O~
O _~) \ V__O r~~
O
.11~ .
As shown in the preceding equation, the dianhydride reacts first with ~.he diamine to ~orm the corresponding polyamic acid, with the number of ~oles of diamine entering into the reaction depending on the proportion of the reactants. In the equation shown, n is O
or an integer ranging from 1 to about 15 or higher, depending on the reactant proportions. That variable is generally referred ~o as the de~ree of polymerization of the oligomer commonly denoted DP. When n is 0, the oligomer contains a single mole of diamine for each two moles of dianhydride presentS and thus the degree of polymerization is 1~ ~hen n equals 1, and thus 2 moles of diamine are present for each 3 moles of dianhydride, the degree of pol~merization is 2, and so on.
As will be appreciated by those skilled in the art, the predominant degree of polymerization can be controlled by controlling the proportions of the reactant.
Nonetheless, there is always a tendency for the reaction to form mixtures. F'or example, in the preparation of an oligomer of the type shown above having a DP of 1 (n 0), the idealized proportions of a reactant necessary to produce a DP of 1 re~uires the reaction of 1 mole of diamine with 2 moles of dian~lydride and 2 moles of mono-amine. When those proportions are used, the reaction produced contains predominantly a product in which the DP is 1, but also contains in decreasing proportion, oligomers in which the DP
is 2, 3, 4 and so on as well as small amounts of oligomers formed by the reaction of 1 mole of the dianhydride and 2 moles of the mono-a~ine -- thus containing no diamine a~
all.
~ 1 9~
In general, when it is desired to produce an oligomer havin~ a DP of 1, the reactants are used in mole proportions o~ .5 to 1.5 moles of the diamine, 1.5 to 2.5 moles of the dianhydride, and 1.5 to 2.5 moles of the mono-amine~ When an oligomer having a DP of 2 is desired, the molar propor~ions range from 1.5 to 2.5 moles of the diamine, 2.5 to 3.5 moles of the dianhydride, and 1.5 to 2~5 moles of the mono-amine. Similarly, when a DP 3 oligomer is desired, the molar pxoportions are about 2.5 to 3.5 moles of the diamine, 3.5 to 4.5 moles of the dianhydride, and 1.5 to 2.5 moles of the mono amine.
The above structure is, as those skilled in the art will appreciate, an idealized structure, depicting as it does all of the positions where an isoimide or imide group could be formed as isoimide groups. As noted above, such an idealized reaction product is difficult, i~ not imposs~ble, to achieve because of the tendency to form imide groups along with isomide groups. Of course, there is also the tendency of the reaction to produce both cis and trans isomers as well as mixtures thereof. However, the positions at which the isoimide groups form are not criticial to the practice of the invention; the im~ortant feature is that the isoimide groups be present in a su~ficient number so as to reduce the melting point of the resulting oligomer and increase its solubilit~ in common lacquer solvents such as dialkyl ketones, tetrahydrofuran. While the proportion of isoimide groups necessary to reach that result varies somewhat with the nature of the reactants used in preparing the oligomers, it has ~een found that at least 30% isoimide groups serve to decrease the melting point and increase the ~a~ 4 solubility of the resulting oligomers.
Preferred oligomers, in accordance with this embodiment, are prepared from an dianhydride such as 3,4-3',4'-benzophenonetetracarboxylic dianhydride, an amine-terminated aryl polye~her, and an amino phenylacetylene mono-amine.
In accordance with yet another embodiment of the presen~ invention, it is also possible, and some~imes desirable, to employ reactants in which the end-capping group containing a polymerizable functional group also contains an anhydride group. In accordance with this embodiment of the invention, a dianhydride having the formula:
O O
Il 11 O~C~C~o Il 11 O O
is reacted with a diamine having the formula:
to form an amine terminated polyamic acid which is then reacted with an anhydride having the formula:
O~C~R
~ C~
wherein R7 is a radical containing an alkenylene group or a trivalent organic group, which is preferably an aryl group, having substituted thereon a function group capable of under-going addition polymerization reactions as described above.
` - 21- .
l`he resultin~ product is then subjected to a d~hyaration reaction to convert at least some o~ the amic acid ~roups to isoi~ide groups. This concep'.-, wi~hout limiting the invention as to theory, may 1~ illustrated by the ~ollowin~ equation:
~.~
, J ~ f~
/ \ ~ o o =~ o ~
\ / . l o ~ r~
z ~ p;
, _ .. I _ / ~
I ~ 11\ o/
~ ~ z +
o ~ c~ t~ = o u~ l o=u t~--o 11~\
x ~ ~=o ~; ~o l ~ /
z c~ o \o/
+ . o=l I o o_t~ V~O
o~ . Z
V V--O
/ ~ ~ \ /
o o :~
.,~ .
In the foregoing equation, m denotes the degree of polymerization, with m~l denoting a DP of 1, and so on such that m is 1 to about 15 or higher, depending on the reactant proportions. As with the preceding equations, the products shown above are illustrated in an idealized form, with all of the sites where either imide or isoimide groups could be formed taking the form of an isoimide group. In actual fact, again, some of those groups are in the imide form.
As the functional anhydride, use can be made of a variety of mono-anhydrides f ~uch as the ~ollowing:
4-ethynyl-phthalic anhydride, 4-vinyl-phthalic anhydride 4-cyano-phthalic anhydride Maleic anhydride Bicyclo[2,2,1]hept-2-ene-5,6-dicarboxylic anhydride The use of maleic anhydride produces an oligomer containing the following idealized structure:
~ ; - N J C /C - N - R5- - N j C~ ~H
H~C~c / C R /0 ~ c~c~
Il . 11 11 11 O O O _ m O
while the use of a bicycloheptene anhydride of the ~ormula:
o ~C ~l Rlo wllerein R8, Rg and Rl~ are each H or lower alkyl yield~
an ideallzed structure as follows:
~ ~ 5 ~ O/c ~ C\o N - R5 - N -~C
Rlo o 8 o 9 Rlo The oligomers of the present invention are used in th~ same manner as those described in U;S. Patent Nos.
3,864,309, 3,845,018, 3,~79,349 and 3,928,45G to produce cured resins having high strength and ~emperature characteristics as well a~ low void contents. Without limiting the present invention as to the theory, it is believed that the isoimide groups present in the ol igomers of this invention are, w~len subjected to elevated te~per~ture during cure, convert ~o the corresponding imide.
Thus, the properties and physical chara~teristics of cured resins made from the oli~omers of the present invention are virtually the sal~e as those described in the foregoing patents.
Having described the basic concepts o the present invention, reference is now made to t~le following ex~mples, which are provided by way of illustration, and not ~y way of limit~tion, of the practice of the invention in making the oli~umers and using the~ in the form of cured resins.
,,~
,J
-25- ~
l:xample 1 This example illustrates the preparation of a bis-isoimide from a mono-amine and a dianhydride.
Benzophenonetetracarboxylic dianhydride (lS~0 ~, grams; 0.0466 mole) in 250 ml of tetrahydre~uran at 60-~5C
' was reacted with 3-aminophenylacetylene (iO.9 grams, 0.0932 mole) for 1 hour. The solution was cooled and treated with .
trifluoroacetic anhydride (60 grams~ maintaining the temperature at 10-1~C. The reaction mixture was kept at 20-25C for 18 hours and the bis-isoimide recovered by precipitation in hexane and then dried in vacuum. The bis-isoimide was mostly isoimide (about 90%); the remainder, imide as determined by infrared spectroscopy. A yield of 17 grams was isolated, melting at 115-120C.
Example 2 This example illustrates the preparation of an acetylene-terminated isoimide oli~omer having a degree of polymerization of 1.
A three-necked one liter round bottom was fitted with a heating mantle, Tru-bore stirrer, reflux condenser, thermometer and addition funnel. The top of the reflux condenser was protected from atmospheric moisture with a drying ~ube.
The ~lask was charged with benzophenonetetracarboxylic dianhyd~ide (30 grams, 0.0~32 mole) and dry tetrahydrofuran -26- ~
(30~ ml). l~le solution was heate~ to a gencle reflux and a sol~ltion of 1,3 di(3-an)ino~herloxy~ellzene (13.9 grams, .0476 mole) in dry tetrdhydrofuran (1~5 ml) was added dropwi~e over a 30-40 minute period. Then the reaction mixture was stirred for an additional 30 minutes and a solution of 3-àminophenylacetylene (10.9 grams, 0.0932 IDole) in dry tetrahydrofuran ~30 ml) addedO
' ' .
After the addition~ the solution was heated at a ;,! ~entle reflux for an additional 30 minutes, cooled to - ambient and trifluoroace~ic anhydride (110 grams~ added dropwise, maintaining the temperature at ambient by means of an ice bath. The reaction mixture was maintained at room temperature for approximately 1~ hours. The oligomer was ~l then precipitated by pouring the reaction mixture into 2300 `
ml of hexarles and the oli~omer washed with fresh hexane.
'I
.
The product was dried in the rotary film evaporator at 85~ for several hours. The bright yellow oligomer weighed 52 ~rams. The product showed a characteristic infrared isoimide absorption at 1805 cm with only a very small amount of imide at 178~ cm . The oligomer mel.ts at 150-155C.
Exam~e 3 This example illustrates the preparation of an oli~orr.er having a de~ree of pol~rnerization of 3.
Io a solution of benzophenonetetracarboxylic c anhydri~e (71.4 ~rams, 0.2217 mole) in dioxane (700 ~1) at : -27-7~oC, a solu~iorl of 1,3-di(3-a~ opl-lenoxy) benzene (48.5 grams ! 0.1661 mole) in dloxane (400 ml) was added dropwise over a one hour period. The solution was stirred for 30 minutes and 3-aminophenylac~tylene ~13.0 grams, 0.111 mole) added all at once. After stirring at 65-70OC for 2 hours, trifluoroacetic anhydride (275 grams) was added over a 15 minute period. '~le mixture was heated for ln additional hour, cooled and the yellow oli~omer (135 grams) isolated by precipitation in hexane.
Example 4 This example illustrates the preparation of an oligomer havi.ng a degree of polymerization of ten.
A three-necked, l-liter, round-bottomed flask was fitted with a heating mantle, Tru-bore stirrer, therrnometer, reflux ~ondenser and addition funnel. The opening of the reflux condenser was protected with a Drierite filled tube.
The flask was charged with benzophenonetetracarboxylic dianhydride (28.1 grams, 0.0873 mole~ and dry tetrahydrofuran (300 ml). The mixture was heated to just below re~ x and a solution of 1,3-di(3-aminophenoxy) ~enzene (23.2 grams, 0.0795 mole) in dry tetrahydro~uran (250 ml) was added drop-wise over a l-hour period. Then a solution of 3-aminophenyl-acetylene (l.S6 grams, 0.01585 mole) in a dry tetrahydrofuran (10 ml) was added. After the addition, the solut;on was heated at reflux for another hour, coo]ed to 10C, and tri~luoroacetic anhydride (120 grams) added dropwise with good stirring.
.
l`he reac~ion Inixture was kep~ ak ambient temperat-lre for approxir,ately 18 hours . The insoluble taLfy-like product was triturated with approximately 125 ml of dry tetrahydrofuran to dissolve the product. This was poured into 1 liter of hexanes which precipitated the oligomer.
The rest of the reaction mixture was poured ;nto 1 liter of hexanes and the precipitated product filter d, washed with hexane, and dried in the rotary film vaporator under vacuurn at ~0C. The product weighed 49 grams.
Films cast from a dimethylformamide solution, and cured at 700 DF for one hour, yielded tensile strengths of 14,000 psi at room temperature and elongations of 3%.
Example 5 . .
This example illustrates the preparation of another oligomer having a DP of 1.
To a solution of benzophenonetetracarboxylic dianhydride (48.3 grams, q.150 mole) in tetrahydrofuran (500 ml) at 60-65C, a solution of 4,4'-oxydianiline (15.0 grams, 0.075 mole) in tetr,ahydrofuran (200 ml) was adcJed dropwise over a 35 minute period. After the addition, the reaction mixture was heated at reflux ~or another 30 minutes and a solution of 3-aminophenylacetylene (17.6 grams, 0,1630 mole) in tetrahydrofuran (100 ml) was added, the mixture was heated at reflux~for 3~ more rninutes and cooled to about 5 to 10C.
Then trifluoroacetic anhydride (200 ~rams) was added and the mixture stirred for about ].6-18 ~lours. Ihe yellow product (60 ~rams) was isolated by precipitation in hexane.
i lnfrared spectroscopy sllowed tl-at the product had Lhe ch~lracteristic isoimide peak at l~OS crll and only very ~mall amount of imide at 1780 c~ . It was soluble in acetone, tetrahydrofuran and a number of other solvents.
It Inélted at 160-165C and cured readily a~ove its melting point. A ~`g greater than 40~C was obtained ~or this product.
Exarnple_6 ! This exa~ple illustrates the preparation of a ~aleic anhydride capped oligomer having a DP of 1.
~ .
To a solution of 1,3-di(3-aminophenoxy3 benzelle (40.0 grams, 0.1342 mole) in tetrah~drofuran (300 ml) at 60-65C, ~ warm solution of ben~ophenone~etrac~rboxylic dianhydride ~21.h grams, 0.06711 mole) in tetrahydrofuran (525 ml) WAS added dropwise over a 45 minute period. After I the addition the solution was heated for an additional 45 inutes and a solution of Inaleic anhydride (13.2 grams, 0.1342 mole) in tetra~ydrofuran (100 ml) was addedg the solution heated for 45 minutes more, cooled to 10C .and trifluoroacetic anhydride (200 grams) added dropwise. A~ter stirring at ~0-25C ~or 18 hours the product (57 grams) was isolated by precipitation in hexane and vacuur~ drying. This oli~omer had appreciable solubility in A nu~nber o solvents, (acetone, ~etrahydrofuran, ~lycolic ethers) and rnelted 155-C.
':
-3~- _ Each of the oligomers prepared in Examples 1-6 was compared to the corresponding oligomer which was in the imide form, as opposed to the isoimide form. In each case, the is~imide oligomers o~ this invention were soluble in ketones, alcohols, amides, glycol ethers and cycloaliphatic ethers (all of which are common lacquer sol~ents) whereas the corresponding imide oligomers were insoluble in such solvants, being soluble only in N-methylp~rrolidinone and N,N-dimethylformamide.
In addition, the melting points of the ~arious oligomers were compared, as well as, in some instances, the gel time. The results of khese comparisons is set forth in the following table:
Table 1 .
FormComposition Melting Point Gel Time Min (TC) . ~
Isoimide 115-120C
~:xample 1 Imide form Intractable 0 Isoimide 145-150C 15-30 (191C) Example 2 Imide form > 200C 3 (250C) _ _ . . . .
Isoimide 150-155C 15-30 (191C) Example 3 Imide form > 200C 3-5 (250C) .. . . . .. ... .. _ . ... _ . ._--Isoimide 160-165C
Example 4 Imide foxm ~ 200C
Isoimide 155-160C
Example 5 Imide form ~ 230C
.
Isoimide 150-160C
Example 6 Imide form --.. . .
~ ~ 31 -ln each instance, the lsoirilide form oE ~he oligomer embodying the concepts of this invention had a meltin~ point considerably lower than ~he corr~sponding imide form.
le 7 ~; :
` This example illustrates the preparation of a cyano-terminated isoimide having a DP of 1.
., :
~ . Using the procedure described in Example 2, 1 mole .1 of 3,31,4,4~ diphenyltetracarboxylic dianhydride is reacted with 1/2 mole of bis(4 aminophenyl)dimethyl silane, and then the product of the reaction is reacted with 1 mole of ~'' ` .
3-aminobenzonitrile.
The product is then dehydrated, and analyzed for infrared isoimide absorption. The resulting isoimide oligomer can be copolymerized with terephthalonitrile-N,N'-dioxide to form a copolymer in accordance with the teachings of U.S. Patent No. 3,864,309.
EXam~ 8 This example illustrates the preparation of a bis-isoimide prepared from pyromellitic anhydride and 3-aminophenyl methacrylate.
Using the procedure illustrated in Example 1, 1 mole of pyromellitic anhydride is reacted with 2 moles of 3-aminophenyl methacrylîc acid. After the reaction is completed, - : 32-the reactiorl mix~ure 1s cooled alld ~lehydrcltecl usin~, ket~lle as a dehydrating agerl~, .
Infrared absorption demonstrates the presence of isoimide ~roups.
~1 Example 9 ., l Ihis example illustrates the preparation of a bis-isoimide form allylamine and 2,3,6,7-naphthalenetetracarboxylic dianhydride.
.
Using the procedure described in Example 1, the above reactants are refluxed to form the corresponding ~ polyamic acid, and then the reaction product is dehydrated ,J, with trifluoroacetic anhydride.
Infrared absorption indicates the presence of iso-j imide groups.
i~
i ~xample 10 .
This example illustrates the preparation of a film Erom an acetylene-terminated isoimide having a degree of polymerization of ten (from Example 4).
A 20 weight percent solids content of the oligomer in solvents such as methyl ethylketone, N,N-dimethylformamide~
N,N-dimethylacetamide or N-methylpyrrolidinone is cast on a ~lass plate with a doctor blade to yield a 1-2 mil ~et filn?.
The plate with the film is prebaked at 150~F for l hour and .
-33- ~
.. . . . . .. ... . .. . .
chen cured stepwi~e ~lsing 40()~ for 15 minuLes; 500~ ior lS
~inutes, 600F for 15 minutes and fiTlally at 700F ~or l hour in an air~circulatin& oven.
I
The film made in this way was found to have a I tensile strength of 14,000 psi and an elongation of 3 percent. A Tg as deter~ined using l`l~lA was ound ~o be 230C.
xample ll This example illustrates the preparation of a graphite fiber composite using standard-vacuum bag technolo~y.
An acetylene-terminated isoimide having a degree of polymerization of one (from Example 2) was dissolved in a 95:5 percent by volume mixture of methylethylketone: N-- methylpyrrolidinone to a solids content. of 25 percent by weight. The lacquer was brushed on unidirectional hTS-2 fibers wound on a 5" x 6" aluminum tool. The prepreg was air dried until the methylethyl ketone has evaporated. This was repeated until the wet resin content was brought up to about 40-45 percent.
The dried graphite prepreg was laid up into 8 ply cvnstruction in the followin~ orientat~on: 0, 90, 90, 0, 0, 90, 90, 0. ~hen required for additional tack, the preprey, was mlst coated with N-methylpyrrolidinone. The construction was placed into a vacuum oven with 2 plles of air weave and 1 ply of TX 1040 on the outer prepreg surfaces and dried at 125F ~or 4 hours. The prepreg was taken ou~
of the oven ilncl reba~,ged as described above and placed into an autoclave. The initial pressure was 30 psi and 25 inches of mercury vacuum and the ternperature raised to 375F in 30 minutes. ~`hen the pressure increased to 150 psi with a 30 inch mercury vacuum and held for 2 hours. The part was cooled to 150I~ under air and vacuum pressure. The autoclave is then vented, the part removed ~nd the formed part postcured ln a standard air circulating oven. A dense non-porous laminate was obtained.
Example 12 . , , This example illustrates the preparation of a bis-isoimide prepared from pyromellitic anhydride and propargyl ~,, amlne.
.i, .
::~! ' Using the procedure described in Example l, one -mole of pyrornellitic anhydride in tetrahydrofuran is reacted with two moles of propargyl amine. The reaction mixture was cooled and then treated wlth a dehydrating agent while maintained at a temperature of about 20C. The product is determined to be predominantly a bis-isoimide having the formula:
HC - C - CH2 ~ ~ C~ N - CH2 - C~CH
':1 ` O . o ' l ~ .
as well as the position isomer thereof~
., .
-35~
Exarn~le 13 This example illustrates the preparation of a bis-isoimide l~repared by reaction of 3,3',4,4'-diphenyltetra-carboxylic dianhydride and 3-aminobenzonitrile.
Using the procedure illustrated n E~ample l, one mole of dianhydride is reacted with two moles of 3-amino-benzonitrile. After reaction and subsequent dehydration, there is isolated from the reaction a bis~isoimide in the form of a mixture oi the cis and trans isomers, the trans isomer having the formula:
O
~ ~ ~ ~ C\- N ~ CN
N ~ N = \C ~ C/
Example 14 This example illustra~es the preparation of a bis-isoimide from reaction of bis(3,4,-dicarboxylicphenyl)sulfone ; dianhydride with 3-(3-aminophenoxy)phenyl acety]elle.
.
Using the procedu~^e illustrated in Example 1l one mole of dianhydride is reacted with two moles of the mono-amine. A~ter the reaction is completed, the product is dehydrated with trifluoroacetic anhydride to form a ~ixture of cis and trans isomers of an isoin~ide, the cis isolner having the followi~g structure:
~ -36-.... . . . ... .. . . .... . .... .. .
~C _ (~ O~--N- C~S~ ~ c (~N
Ii 11 O O
Example 15 l~is example illustrates the prep ration of bis-isoimide having a DP of lo Using the procedure described in Example 2, two moles of 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride are reacted with 1 mole of 1,3-di(3-aminophenoxy)benzene, and then the product of the reaction is reacted with 3-amino-benzonitrile. After the polyamic acid is formed~ the product o the reaction is dehydrated with trifluoroacetic anhydride to for~l an isoimide-containing oligo~er.
Example 16 This example illustrates the preparation of an oligomer having a DP of 1.
Using the procedure described in Example 2 two uoles of pyromellitic anhydride are reacted with one mole of oxydianiline, and then two moles of 3-aminophenyl acetylene are added to the reaction. The reaction mixture is then cooled and dehydrated with trifluoroacetic anhydride to form the corresponding isoimide-containing oligomer. It has been determined that yield of isoi~ide groups, to the exclusion of imide groups, is increased when the anhydride is purified ~to rel~ove all carboxylic acid-containing impurities.
-37- _ :
~xam~)le 17 This example illus~rates the preparation of an isoimide-containing oligomer having a DP of 1.
Using the procedure described in Example 2, two moles of 2,2-bis(3,4-dicarboxyphenyl)hexafl oroisopropylidine dianhydride are reacted with one mole of ~,6-diaminopyridine.
The product is then reacted with 3-(3-aminophenoxy)phenyl acetylene. The reaction mixture is cooled and dehydrated to form ~he corresponding isoimide-cont~ining oligomer.
Example 18 .
This example illustrates the preparation of an ..
isoimide-containing oligomer having a DP of I similar to the oligomer of Example 1 but containing very little imide isomer.
A 1 liter, three-necked round bottom flask fitted with a Tru-bore stirrer, thermometer and dropping funnel was charged with carboxylic acid free benzophenone-tetracarboxylic dianhydride (45 grams, 0.1398 mole) and dry tetrahydrofuran (400 ml). To the slurry, at 27C (aMbient), a solution of 1,3-di(3-aminophenoxy)benzene (20,40 ~ran~s, 0.06988 mole) in dry tetrahydrofllran (200 ml) was added drop~ise with good stirring. Shortly after starting the addition, all the solids went into solution. Then to the light amber, clear solution, a solution of 3-aminophenylacetylene (16~35 grams, 0.1398 mole) in dry tetrahydrofuran (100 ml) was added.
The solu~ion was allowed to stand at ambient -3~- -t~ perat~r~ ~or approximately 16 hours anc] th~n cooled to -10~. Tri~luoroace~ic anhydride (68.5 gr~rn9, 0.326 mole) was added dropwise carefully maintaining the temperature below 0C. The addition took approximately 10 minutes.
After the addition, the solution was allowed to stand ior 105 minutes and the oligomer precipitated by pouring the solution into a large quantity of hexane (4 llters). The oligomer was filtered and washed with fre~h hexane and dried under vacuum, starting first at ambient temperature and finally increasing the temperature to 90~C.
The oligomer (72 grams) was mostly isoimide as evidenced by the presence of the 1805 cm l peak in an infrared spectrogram and no peak at 1780 cm (imide).
It will be understood that vàrious changes and modifications can be made in the details of procedure, formulation and use without departing from the spirit of the invention, especially as defined in the ~ollowing claims.
Claims (23)
1. A polymerizable isoimide-containing oligomer obtainable by (a) reacting a carboxylic acid dianhydride having the formula:
wherein R is a tetravalent organic group containing 2 to 27 carbon atoms with a functional amine having the formula:
wherein R1 is a divalent organic group containing 1 to 20 carbon atoms and X is an unsaturated functional group capable of undergoing addition by polymerisation, and (b) dehydrating the product under conditions to form an isoimide-containing oligomer.
wherein R is a tetravalent organic group containing 2 to 27 carbon atoms with a functional amine having the formula:
wherein R1 is a divalent organic group containing 1 to 20 carbon atoms and X is an unsaturated functional group capable of undergoing addition by polymerisation, and (b) dehydrating the product under conditions to form an isoimide-containing oligomer.
2. A polymerizable isoimide-containing oligomer obtainable by (a) reacting a carboxylic acid dianhydride having the formula wherein R is as specified in claim 1 with a diamine having the formula:
wherein R5 is a divalent organic group containing 6 to 30 carbon atoms, (b) reacting the product of (a) with a functional amine having the formula:
wherein R1 and X are as specified in claim 1, and (c) dehydrating the product of (b) under conditions to form an isoimide-containing oligomer.
wherein R5 is a divalent organic group containing 6 to 30 carbon atoms, (b) reacting the product of (a) with a functional amine having the formula:
wherein R1 and X are as specified in claim 1, and (c) dehydrating the product of (b) under conditions to form an isoimide-containing oligomer.
3. An oligomer according to claim 1 or 2 wherein X is selected from:
wherein R4 is H or -CH3, and -CN.
wherein R4 is H or -CH3, and -CN.
4. An oligomer according to claim 1 ox 2 wherein the functional amine is 3-aminophenyl acetylene.
5. A polymerizable isoimide-containing oligomer obtainable by (a) reacting a dianhydride having the formula:
wherein R is as specified in claim 1, with a diamine having the formula:
wherein R5 is a divalent organic group containing 6 to 30 carbon atoms, (b) reacting the product of (a) with a monoanhydride having the formula:
wherein R7 is a radical containing an alkenylene group or a trivalent aryl group having substituted thereon an unsaturated functional group capable of undergoing addition polymerisation and (c) dehydrating the product of (b) under conditions to form an isoimide-containing oligomer.
wherein R is as specified in claim 1, with a diamine having the formula:
wherein R5 is a divalent organic group containing 6 to 30 carbon atoms, (b) reacting the product of (a) with a monoanhydride having the formula:
wherein R7 is a radical containing an alkenylene group or a trivalent aryl group having substituted thereon an unsaturated functional group capable of undergoing addition polymerisation and (c) dehydrating the product of (b) under conditions to form an isoimide-containing oligomer.
6. An oligomer according to claim 5 wherein the monoanhydride is maleic anhydride.
7. An oligomer according to claim 5 wherein the monoanhydride has the formula:
wherein R8, R9 and R10 are the same or different and are each selected from H or lower alkyl.
wherein R8, R9 and R10 are the same or different and are each selected from H or lower alkyl.
8. An oligomer according to claim 1 or 2 wherein R1 is an alkylene group containing 1 to 5 carbon atoms or an arylene group containing 6 to 30 carbon atoms.
9. An oligomer according to claim 1, 2 or 5 wherein R is a tetravalent aryl radical containing 6 to 18 carbon atoms.
10. An oligomer according to claim 1 wherein R is selected from:
wherein Y is selected from:
wherein x is an integer from 1 to 5, a group having the formula:
wherein R2 and R3 are each selected from aryl and alkyl.
wherein Y is selected from:
wherein x is an integer from 1 to 5, a group having the formula:
wherein R2 and R3 are each selected from aryl and alkyl.
11. An oligomer according to claim 10 wherein the dianhydride is benzophenonetetracarboxylic dianhydride.
12. An oligomer according to claim 2 or 5 wherein the diamine is a compound having the formula:
wherein Y is as specified in claim 10.
wherein Y is as specified in claim 10.
13. An oligomer according to claim 2 or 5 wherein the diamine is 1,3-di-(3-aminophenoxy) benzene or 4,4'-oxydianiline.
14. Cis and trans isomers of an oligomer having the formulae:
and wherein R, R1 and X are as specified in claim 1.
and wherein R, R1 and X are as specified in claim 1.
15. An oligomer according to claim 14 when in admixture with small amounts of an oligomer having the formula:
16. An oligomer having the formula:
wherein R, R1, and X are as specified in claim 1, R5 is as specified in claim 2, and n is from 0 to 15.
wherein R, R1, and X are as specified in claim 1, R5 is as specified in claim 2, and n is from 0 to 15.
17. An oligomer having the formula:
wherein R is as specified in claim 1, R5 is as specified in claim 2, R7 is as specified in claim 5, and m is from 1 to 15.
wherein R is as specified in claim 1, R5 is as specified in claim 2, R7 is as specified in claim 5, and m is from 1 to 15.
18. A process for the preparation of an isoimide-containing oligomer which comprises:
(a) reacting a carboxylic acid dianhydride having the formula:
wherein R is as specified in claim 1, with a functional amine having the formula:
wherein R1 and X are as specified in claim 1, and (b) dehydrating the product of (a) under conditions to form an isoimide-containing oligomer.
(a) reacting a carboxylic acid dianhydride having the formula:
wherein R is as specified in claim 1, with a functional amine having the formula:
wherein R1 and X are as specified in claim 1, and (b) dehydrating the product of (a) under conditions to form an isoimide-containing oligomer.
19. A process for the preparation of an isoimide-containing oligomer which comprises:
(a) reacting a carboxylic acid dianhydride having the formula:
wherein R is as specified in claim 1, with a diamine having the formula:
wherein R5 is a divalent organic group containing 6 to 30 carbon atoms, (b) reacting the product of (a) with a functional amine having the formula:
wherein R1 and X are as specified in claim 1, and (c) dehydrating the product of (b) under conditions to form an isoimide-containing oligomer.
(a) reacting a carboxylic acid dianhydride having the formula:
wherein R is as specified in claim 1, with a diamine having the formula:
wherein R5 is a divalent organic group containing 6 to 30 carbon atoms, (b) reacting the product of (a) with a functional amine having the formula:
wherein R1 and X are as specified in claim 1, and (c) dehydrating the product of (b) under conditions to form an isoimide-containing oligomer.
20. A process for the preparation of an isoimide-containing oligomer which comprises:
(a) reacting a carboxylic acid dianhydride having the formula:
wherein R is as specified in claim 1, with a diamine having the formula:
wherein R5 is a divalent organic group containing 6 to 30 carbon atoms, (b) reacting the product of (a) with a monoanhydride having the formula:
wherein R7 is a radical containing an alkenylene group or a trivalent aryl group having substituted thereon an unsaturated functional group capable of undergoing addition polymerisation, and (c) dehydrating the product of (b) under conditions to form an isoimide-containing oligomer.
(a) reacting a carboxylic acid dianhydride having the formula:
wherein R is as specified in claim 1, with a diamine having the formula:
wherein R5 is a divalent organic group containing 6 to 30 carbon atoms, (b) reacting the product of (a) with a monoanhydride having the formula:
wherein R7 is a radical containing an alkenylene group or a trivalent aryl group having substituted thereon an unsaturated functional group capable of undergoing addition polymerisation, and (c) dehydrating the product of (b) under conditions to form an isoimide-containing oligomer.
21. A process according to any of claims 18 to 20 wherein said dehydrating is performed by reacting said product with trifluoroacetic anhydride or N,N-dicyclohexyl-carbodiimide at a temperature below 60°C.
22. An oligomer according to claim 2 or 5 wherein R
is selected from:
wherein Y is selected from:
wherein x is an integer from 1 to 5, a group having the formula:
wherein R2 and R3 are each selected from aryl and alkyl.
is selected from:
wherein Y is selected from:
wherein x is an integer from 1 to 5, a group having the formula:
wherein R2 and R3 are each selected from aryl and alkyl.
23. An oligomer according to claim 2 or 5 wherein is selected from:
wherein Y is selected from:
wherein x is an integer from 1 to 5, a group having the formula:
wherein R2 and R3 are each selected from aryl and alkyl, and wherein the dianhydride is benzophenonetetracarboxylic dianhydride.
wherein Y is selected from:
wherein x is an integer from 1 to 5, a group having the formula:
wherein R2 and R3 are each selected from aryl and alkyl, and wherein the dianhydride is benzophenonetetracarboxylic dianhydride.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/286,317 US4438273A (en) | 1981-07-24 | 1981-07-24 | Isoimide containing oligomers |
| US286,317 | 1981-07-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1182114A true CA1182114A (en) | 1985-02-05 |
Family
ID=23098056
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000406262A Expired CA1182114A (en) | 1981-07-24 | 1982-06-29 | Isoimide containing oligomers |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4438273A (en) |
| EP (1) | EP0071372B1 (en) |
| JP (3) | JPS5824579A (en) |
| KR (1) | KR890002775B1 (en) |
| CA (1) | CA1182114A (en) |
| DE (1) | DE3268660D1 (en) |
Families Citing this family (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5516876A (en) | 1983-09-27 | 1996-05-14 | The Boeing Company | Polyimide oligomers and blends |
| US5521014A (en) | 1981-11-13 | 1996-05-28 | The Boeing Company | Extended multidimensional ether or ester oligomers |
| US5705598A (en) | 1985-04-23 | 1998-01-06 | The Boeing Company | Polyester sulfone oligomers and blends |
| US5969079A (en) | 1985-09-05 | 1999-10-19 | The Boeing Company | Oligomers with multiple chemically functional end caps |
| US5210213A (en) | 1983-06-17 | 1993-05-11 | The Boeing Company | Dimensional, crosslinkable oligomers |
| US5693741A (en) | 1988-03-15 | 1997-12-02 | The Boeing Company | Liquid molding compounds |
| US5512676A (en) | 1987-09-03 | 1996-04-30 | The Boeing Company | Extended amideimide hub for multidimensional oligomers |
| US4699803A (en) * | 1983-11-30 | 1987-10-13 | International Business Machines Corporation | Method for forming electrical components comprising cured vinyl and/or acetylene terminated copolymers |
| US4613637A (en) * | 1983-12-27 | 1986-09-23 | Hughes Aircraft Company | Copolymers utilizing isoimides and method of preparing same |
| US4532270A (en) * | 1984-01-27 | 1985-07-30 | National Starch And Chemical Corporation | High temperature stable adhesive compositions employing aromatic polyimide and polyisoimide bis-acetylene additives |
| DE3411660A1 (en) * | 1984-03-29 | 1985-10-03 | Siemens AG, 1000 Berlin und 8000 München | METHOD FOR PRODUCING POLYIMIDE AND POLYISOINDOLOCHINAZOLINDION PRE-STAGES |
| US4542257A (en) * | 1984-04-27 | 1985-09-17 | Hughes Aircraft Company | Solar cell array panel and method of manufacture |
| US5618907A (en) | 1985-04-23 | 1997-04-08 | The Boeing Company | Thallium catalyzed multidimensional ester oligomers |
| US4551522A (en) * | 1985-04-26 | 1985-11-05 | E. I. Du Pont De Nemours And Company | Process for making photopolymerizable aromatic polyamic acid derivatives |
| US5610317A (en) | 1985-09-05 | 1997-03-11 | The Boeing Company | Multiple chemically functional end cap monomers |
| US5817744A (en) | 1988-03-14 | 1998-10-06 | The Boeing Company | Phenylethynyl capped imides |
| JPH0737528B2 (en) * | 1990-12-14 | 1995-04-26 | チッソ株式会社 | Method for producing polyisoimide |
| JPH04342786A (en) * | 1991-05-17 | 1992-11-30 | Kanebo Nsc Ltd | Heat-resistant adhesive material |
| JPH05105777A (en) * | 1991-10-15 | 1993-04-27 | Sumitomo Bakelite Co Ltd | Polyisoimide film and production of substrate for flexible printed circuit with the same |
| JPH05105755A (en) * | 1991-10-15 | 1993-04-27 | Sumitomo Bakelite Co Ltd | Polyisoimide and its film |
| WO2002001278A1 (en) * | 2000-06-28 | 2002-01-03 | Hideki Kanaya | Outward spreading device for eyeglasses' temple |
| JP2019070074A (en) * | 2017-10-10 | 2019-05-09 | Jnc株式会社 | Polymer having isoimide bond and production method thereof, and polymer having imide bond |
| JP7086882B2 (en) * | 2019-03-22 | 2022-06-20 | 富士フイルム株式会社 | Curable resin composition, cured film, laminate, method for manufacturing cured film, and semiconductor device |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3282898A (en) * | 1963-11-21 | 1966-11-01 | Du Pont | Treatment of aromatic polyamide-acids with carbodiimides |
| US3413267A (en) | 1966-05-17 | 1968-11-26 | Du Pont | Copolyimide-isoimide polymers |
| US3516967A (en) | 1968-10-28 | 1970-06-23 | Du Pont | Polyiminoimide and polyamide nitrile compositions |
| US3998786A (en) | 1973-05-25 | 1976-12-21 | University Of Notre Dame Du Lac | Process for preparing aromatic polyimides, polyimides prepared thereby |
| JPS5953917B2 (en) | 1976-07-23 | 1984-12-27 | 武田薬品工業株式会社 | Tetrahydroisophthalimide derivative and method for producing the same |
| US4097456A (en) * | 1977-03-28 | 1978-06-27 | Gulf Research & Development Company | Preparation of acetylene-substituted polyimide oligomers and polyimide polymers |
| US4133792A (en) * | 1977-05-09 | 1979-01-09 | Gulf Oil Corporation | Resin solutions of acetylene containing polyamide acids |
| US4168360A (en) | 1978-07-25 | 1979-09-18 | Plastics Engineering Company | Polymerization products of vinyl-terminated polyimide derivatives |
| US4307220A (en) | 1979-05-17 | 1981-12-22 | The United States Of America As Represented By The Secretary Of The Air Force | Purification of acetylene-terminated polyimide oligomers |
| US4276407A (en) | 1979-08-16 | 1981-06-30 | Hughes Aircraft Company | Acetylene terminated imide oligomers which melt at low temperatures |
-
1981
- 1981-07-24 US US06/286,317 patent/US4438273A/en not_active Expired - Lifetime
-
1982
- 1982-06-29 CA CA000406262A patent/CA1182114A/en not_active Expired
- 1982-07-16 EP EP82303744A patent/EP0071372B1/en not_active Expired
- 1982-07-16 DE DE8282303744T patent/DE3268660D1/en not_active Expired
- 1982-07-22 KR KR8203279A patent/KR890002775B1/en active
- 1982-07-23 JP JP57127794A patent/JPS5824579A/en active Granted
-
1987
- 1987-05-29 JP JP62134753A patent/JPS63118330A/en active Granted
- 1987-05-29 JP JP62134752A patent/JPS63118329A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0327574B2 (en) | 1991-04-16 |
| JPS63118330A (en) | 1988-05-23 |
| JPH0360830B2 (en) | 1991-09-17 |
| DE3268660D1 (en) | 1986-03-06 |
| US4438273A (en) | 1984-03-20 |
| JPS63118329A (en) | 1988-05-23 |
| KR890002775B1 (en) | 1989-07-28 |
| KR840000592A (en) | 1984-02-25 |
| EP0071372B1 (en) | 1986-01-22 |
| JPS5824579A (en) | 1983-02-14 |
| EP0071372A1 (en) | 1983-02-09 |
| JPH0327573B2 (en) | 1991-04-16 |
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