CA1068696A - Catalytic trimerization of aromatic nitriles and triaryl-s-triazine ring cross-linked high temperature resistant polymers and co-polymers made thereby - Google Patents

Abstract

ABSTRACT:
Triazine compounds and cross-linked polymer compositions are made by heating aromatic nitriles to a temperature in the range of from about 100°C.
to about 700°C., and preferably in the range of from about 200°C. to about 350°C. in the presence of a catalyst or mixture of catalysts selected from one or more of the following groups: (A) organic sulfonic and sulfinic acids, (B) organic phosphonic and phosphinic acids, and (C) metallic acetylacetonates, at a pressure in the range of from about atmospheric pressure to about 10,000 p.s.i., and preferably in the range of from about 200 p.s.i. to about 750 p.s.i.
Aromatic nitrile-modified (terminated and/or appended) imide, benzimi-dazole, imidazopyrrolone, quinoxaline, and other condensation type pre-polymers or their precopolymers are made which are trimerized with or without a filler by the aforementioned catalytic trimerization process into triaryl-s-triazine ring containing or cross-linked polymeric or copolymeric products useful in applications requiring high thermal-oxidative stability and high performance structural properties at elevated temperatures.

Description

`` 1al6~3~;96 B~CKGROUNI) OF THE INVENTION:

Field of the Invention The invention relates to a novel process for preparing triaryl-s-triazines from aromatic nitriles, and triaryl-s-triazine ring containing or cross-linlced polymers or copolymers from aromatic nitrile-modified (terminated and/or appended) prepolymers or precopolymers in the presence of a novel catalyst and relates to the novel compounds and polymers produced by the above process. More particularly, the invention relates to the use of the novel process, polymers and compounds to produce fiber-reinforced composites of outstanding thermal-oxidative stability.

Description of the Prior Art Conventional condensation-type aromatic polyimides, polybenzimidazoles -polyimidazopyrrolones, and polyquinoxalines exhibit excellent thermal-oxidative stability, but they are, however, difficult to process into fiber-reinforced composites. Various workers have attempted to solve the process-ability problem of these high temperature resistant polymers with varying degrees of success.
Prior to the present invention, aromatic nitriles were trimerized at a temperature in the range of 350C. to 500C. and under a pressure of 35" 000 to 50, 000 atmospheres. Bengelsdorf, I. S., "High Pressure High Temperature Reactions. I. The Trimerization of Aromatic Nitrilesl', J. Amer. Chem. Soc.
Vol. 80, p. 803 (1958). In U, S. Patent No. 2, 503, 999, Cairns et al. trimeriz-ed aromatic nitriles at a temperature in thé range of 60C. to 150C. and under a pressure above 3, 000 atmospheres with an alcohol catalyst. In U. S.
Patent No. 1, 989, 042, I~unz et al. trimerized aromatic nitriles below room temperature with chlorosulfonic acid sérved as both the solvent and catalyst.

' ., '', ' . ~ _ ~L06869~;

~, In U.S. Patent No, 2, 598, 811, Mahan et al. trimerized aromatic nitriles at a temperature in the range of 66C. to 288C. and under a pressure in the range of 30 p. s. i. to 500 p. s. i. with a catalyst selected from the groups consisting of hydrides and amldes of alkali metals, and hydrides of alkaline earth metals.
In U. S. Patent No. 3, 095, 414, Spainhour synthesized triazines at a tempera-ture in the range of 25~C. to 150C. in a sealed reactor with a catalyst mixtur selected from one group consisting of metallic salts such as titanium tetra-chloride and another group consisting of organometallic compounds such as ~trialkyl aluminum. In U.S. Patent No. 3, 060,179, Toland polymerized aro-matic nitriles at a temperature in the range of 200C. to 400C. in an open or pressure vessel with a metal salt catalyst selected from the group consisting of copper, manganese, and cobalt. In U. S. Patent No. 3, 678, 049, Gump polymerized aromatic nitriles at a temperature in the range of 200C. to 350C
in an autoclave under an initial pressure of about 0. 001 mm of Hg with 2-pyr-rolidinone served as both the catalyst and solvent. Because of either the super high pressure required or the quantity and particularly the nature of catalyst used, none of the trlmerization methods previously described are suitable for processing the aromatic nitrile-modified (terminated and/or appended) conden-sation type prepolymers into s-triazine ring cross-linked high temperature resistant matrix resins for fiber reinforced composites.
Prior to the present invention, Lubowitz, in U.S. Patent No. 3, 528, 950, developed a new system of processable thermally stable modified polyimides as matrices for fiber-reinforced composites. These processable modified ~
polyimides, known as addition-type polyimides were made from imide oligo- ~-mers terminated with norbornene groups. After removal of the solvent, these norbornene-terminated imide oligomers can be polymerized and/or cross-linked by an addition reaction primarily through the double bonds to yield ,- ', ' ' ' " " ', ' , , , ', ' ", ', ', ,' ,' , ,, ~ ~: : . .. . .... . . .

~L~)68696 thermally stable polyimides without the evolution of by-products. Fiber-reinforced composites made from these :~.:
norbornene-terminated polyimides, however, cannot reach - :
an upper service temperature of about 315Co This is apparently due to the presence of the aliphatic cyclic structure derived from the norbornene groups. : :
SUMMARY OF THE INVENTION: - :
Accorclingly, this invention provides a process for preparing an aromatic 1,3,5-triazine compound from an aro- .
matie nitrile compound which comprises heating the aromatic , . .
ni$rile to a temperature in the range of from about 100C
to about 700C in the presence of a catalyst consisting essentially of a compound or mixture of compounds from at least one of the following groups: (A) organic sulfonic .
and sulfinic acids, (Bj organic phosphonic and phosphinic acids, and (C)~~met~allic-acetylacteonates, at a pressure in ' '~
the range of from atmospheric pressure to about 10,000 p.s.i.

~. .
. ~ ~

', , ; . .,~

: ' ~, .

~ : . . ', -, .
.
.
, . .

~068696 ~; ~

DESCRIPTION OF T~IE INVENTION: ~
. - .
In accordance with the present invention, trimer~
izable aromatic nitrile compounds are trimerized to form ..
triazine rings by heating such nitriles under substantially .~
.. :: .. . .
anhydrous conditions with a novel catalyst or a catalyst mixture selected from the group consisting of organic sulfonic and sulfinic acids, organic phosphonic and phosphinic acids, and metallic acetylacetonates.
The term "substantially anhydrous conditions" as used herein in reference to trimerization process conditions refers to the fact that the total amount of water present in -~
a reaction zone is such that it does not appreciably~: .
interfere with production of triazine from the starting ~`
materials under a given set of reaction conditions.
"': ' .
,' :
, . .' .:.

2 0 .: . ,.,, , , :
. .: .
' ": ' ''.: " ' '.:
' ~ .

.
,., ". , .:, -5- :

.. . . ... . . .. . . . ... ... . . .

: . ', ', - , , , ,,:. ; ,; . ,', , ' .,,: .: . , - ^\ ~ -1ai~8696 , , , , . ' , Examples of organic sulfonic and sulfinic acids which are suitable as catalysts-~for use in the novel process of this invention included p-toluene sulfonic acid, benzene sulfonic acid, benzene sulfinic acid, naphthalene~-sul-fonic acid and the like. Examples of organic phosphonic and phosphinic acids which are suitable as catalysts for use in the novel process of this invention include trichloromethyl phosphonic acid, phenyl phosphonic acid, phenyl phosphinic acid, and the like. For the two acid catalyst groups mentioned above, examples of suitable catalysts also include derivatives which generate the corresponding acids under the reaction conditions during processing.
Examples of metallic acetylacetonates which are suitable as catalysts for use in the novel process of this invention Include ferric acetylacetonate, zinc acetylacetonate, and the like.
In order to initiate and maintain the trimerization reaction, it is merelynecessary that the amount of catalyst be sufficient, based on molar percentage of the nitrile employed. Except for practical purposes, there is no known maximum amount. However, since the catalyst normally would either have to be separated from or remain in the reaction product it normally would be desirable to employ as little catalyst as necessary to accomplish the desired result. As is readily apparent to one skilled in the art, the amount of catalyst used depends upon the specific catalyst that is employed. There would rarely be any need to employ higher than about 10 mole per cent of catalyst based on the amount of nitrile employed. In general, the catalyst concentrations are within the range of about 0. 01 mole per cent to about 10. 0 mole per cent and the preferred range is from about 0. 05 mole per cent to about 5. 0 mole per cent based on the molar amount of nitrile employed, Reaction times are not critical, but should preferably be of sufricient length to permit the trimeri~ation reaction to be essentially completed. The ~6-,, . ,' . .
~ ~
i ~ ~()6~369~
reaction time is typically dependent on several factors such as the partic~llar catalyst employed, the amount of catalyst employed, the temperature and pressure at which the reaction is carried out, the nitrile employed, and the degree of conversion desired. The time required for reaction of a given S nitrile, catalyst and temperature combination varies depending especially upon the nitrile used in the reaction, but can be adjusted by control of the other process variables, such as equipment, reaction conditions, reactants, etc. A reaction time of from about a day to about three days is normally satisfa ctory. :
Reaction pressures are also dependent on the nitrile, catalyst and temperature employed and are generally in the range of from about atmos-pheric to about 10, 000 1?- s. i., preferably in the range of from about S0 p. s; i.
to about 1, 000 p. s. i., and more preferably in the range of from about 200 p. s.
i. to about 750 p. s. i. reaction is conveniently carried out in an inert atmos-lS phere such as nitrogen if a pressure reactor IS used.
The novel process of this invention for trimerizing aromatic nitrile compounds to the triaryl-s-triazines, and aromatic nitrile-modified prepoly- -~
mers or precopolymers to triaryI-s-triazine ring containing or cross-linked polymers or copolymers is operable at a temperature in the range of from abou 100C. to about 700C., preferably in the range of from about 100C. to about 500C. and more preferably in the range of from about 200C. to about 350C.
Sometimes it is desirable to employ an inert solvent, organic in nature, in which both the catalyst and the reactants are soluble. The inert solvent is preferably an or~anic liquid which is substantially unreactive with both the reactants and the reaction products and in which the reactants are soluble to ~ `
a desired extent. lt is generally preferable to choose one which is readily ''. .... " ' , , ' ' ' ',.. '.' :',, . ' .` ` ~ i ` ~068696 separated from the reaction products. Suitable solvents for the novel process of the present invention include N-methylpyrrolidone, N, N-dimethyl formamid 9 ' ', dimcthylsulfoxidç, cresols, alcohols, 1, 2, -dichlorc)ethane and the like depend-ing on the monomeric reactants used and the chemical structure and molecular weight of the aromatic nitrile-modified prepolymers or precopolymers pro~
duced .
The novel process of this invention for trimerizing aromatic nitrile compounds to form triazine rings may be used generally to trimerize any conventional aromatic n*rile such as benzonitrile, napthonitrile, cyanoan-thracene, and cyanoheterocyclic compounds which may be substituted with alkyl, alkoxy, halogen, nitro, cyano, carbonyl, sulfonyl, carboxyl groups, c`
and the like.
As set forth in Table I below, benzonitrile with electron withdrawing ring substituents such as carboxyl and nitro groups was found to be more susceptible to trimerization than those wlth electron donating substituents such as methyl and methoxy groups, and that as expected the ortho substituted benzonitrile was less susceptible to trimerization than either para or meta substi-uted benzonitriles.
: .
.

... , ,, , .. , , ~, .
..
:;, ." :

. : 1068696 TABLE I
CATALYTICl~L TRIMERIZATION OF SUBSTITIJTED BENZONITRILES
.
Trimerized Product Aromatic Nitrile M. P. (C) Percent Yield M. P. (C) Anisonitrile 55-56 i 6. 0 >340 t217 and 224 ~) p-Tolunitrile 26-28 5. 0 ~340 (278-9*) Benzonitrile -14 14. 0 232-235 (232-3*) o-Nitrobenzonitrile 102-106 37. 8 ~340 m-Nitrobenzonitrile 117-118 51.6 ~340 (342*) p-Nitrobenzonitrile 146-149 52.3 ~340 (~360*)

3, 5-Dinitrobenzonitrile 128-130 54. 0 310 p-Cyanobenzoic acid 220-222 75.0 >340 (374-5*) Terephthalonitrile 231 - 99.5 >340 _ .
*Value in literature Reaction conducted at 232C., 600~750 p. s. i.,for 48 hours, with 5 mole per cent p-toluenesulfonic acid catalyst.
. ' .

. , .
:~ "'' : .. . ".... ..
:. . . , , : .
,: , v - ~ ~(1 6~69 ~ , ., , .
In accordance with the present invention, aromatic nitrile compounds may be trime.rized by the novel process of this invention to form triaryl-s-triazine eompounds that are useful as cross-linking reagents for synthesizing high temperature resistant polymeric products. They may also be useful as intermediate compounds for synthesizing dyestuffs and drugs.
The triaryl-s-triazine compounds produced by the novel process oE this invention include 2, 4, 6-tris (meta-, ortho- or para-carbos~yphenyl)-l, 3, 5-triazine and its ester or hallde derivatives, 2, 4, 6-tris (3', 4'-phthalic anhy-dride)-1,3,5-triazine and tts ester and halide derivatives, 2~a~,6-tris (meta-, ortho- or para-aminophenyl)-l, 3, 5-triaztne, 2, 4, 6-tris (3', 4'-diaminophenyl)-1, 3, S-triaztne, 2, a~, 6-tris (3', 5'-diaminophenyl)-1, 3, 5 -triazine, and 2, 4, 6-tris (meta- or para-substituted phthalimidyl)-l, 3, 5-triazine where the substit-uted groups are monovalent radicals selected from the group consisting of -H, -CN, -F, -Cl, -Br, -N02, -CH3, -NH2, -OCH3, ~>, and substituted aryl .
The aromatic nitrile compounds that are trimerized in accordance with the present invention to produce the aforementioned triaryl-s-triazine com-pounds are aromatic carbocyclic nitriles selected from the group consisting of:

O 1~
¦¦ NC~ ~COOH NC~NH2 , ~--C~

¦ ~ ~H2 ' ~
NH? .

NC~ ~ N ~X

:-- - . .
: . . , . ' ' ' " .
; , , . : .
: , . .. . . . .. . . .
, - , , ; : . .; ;
.. . . .

:
:~6~3696 . ,, . :' , ., whercin X is a monovalent radical selected from the group consisting of -l~I, -CN, -F~, -Cl, -Br, -N~2, -CH3, -NH2, -OC~I39 ~ and substituted aryls, and X may be substituted at the meta and para positions.
The triaryl-s-triazine ring containing or cross-linked polymeric or copolymeric products produced by the novel process of this invention are typically useful in applications requiring high temperature stability and may beprocessed with filler reinforcement, particularly with fiber reinforcement to produce highly heat resistant molded articles.
Fillers suitable for reinforcement to preparing composites by the riovel process of the present invention include graphite fibers such as lIercules' HMS
graphite fibers, etc., high temperature resistant organic fibers such as Du Pont's Aramid fiber, etc., glass fibers with or without coated coupling finishes, glass, quartz, and other ceramic powders, certain metallic powders, whiskers, and wires having high temperature resistant stability.
In accordance with the present invention, novel aromatic nitrile-modified (terminated and/or appended) imide, benzimidazole, imidazopyrro-lone, and quinoxaline prepolymers and aromatic dinitrile compounds includ- ~i ing those aromatic nitrile-endcapped soluble polyarylenes, polyarylene$ulfides polyarylethers, polyarylketones, polyaryisulfones, polysiloxanes, and their copolymers may be trimerized to form neat resins or composites exhibiting good or outstanding thermal-oxidative stability and high performance structur-al properties.
The polyimide class of polymers are known to possess outstanding physical properties, notably a high degree of stability to heat as well as excellent mechanical properties of shaped articles which are fabricated from the polymers, such as films, fibers, laminates, moldlngs, and the lilce.

-' ' ' '' . ', . . . . . . .
... .. . . . . . . . .
.. ' .

~-~; 1al6~3696 According to the present invention, novel aromatic nitrile-modified imide pre-polymers are disclosed which may be trimerized to form a new system of polyimides which possess the outstanding thermal stability of both polyimides and triaryl-s-triazines.
The novel processable aromatic nitrile-modified imide prepolymers made in accordance with the present invention have one of the following four general structural formulas:

X~ ~ ~ C ~ lc ~ ~ C ~ ~ CN

¦~ N(~ ~BI/ ~N--R2 N~ ~KI'~ ~N--R3 . n X~ /C~ ~ ' ~C~ ~C~ ~C~ ~CN
NC ~ 4 ~ C, N--R2--N~ ~ Rl~C, N--R2--N~ ~R4 \X

. n . ~:

X~ ,C~ C~ ~ ,C.~ ,,, CN
(III) R3--N~ Rl~ N--R2--N~ ~R4 NC ~ ` C~ C ~ `C \X

IIIV) ~ Rl ~N--R2--N~f~ Rl~ ~N--R2--N

;,. .. . . , , ,, , . , . , . , " . ,: , :' ' . :.

r ~ I 1068696 which is the reaction product of a tetracarboxylic acid dianhydride (Va), or its derivatives (Vb) having the structural formulas:
. .
.

(Va) O~ Rl/ ~0, (Vb) Z--C~ I~C--Z

a diamine having the structural formula:
(VI) H2N--R2--NH2 ~
: with a nitrile having one of the following structural formulas, if prepolymer (I), (II) or (IIIj is to be made: ~ ~ . -CN : .
(VII ) H2N--R3 ~C~ ~CN ZiC~ /CN .
: ~c ~n4 \x ~ (VIIIb) ~B4~

10 ~ or without a nitrile if prepolymer (IV) is to be made, . ..
: : ~ wherein n is an Integer from O to 50, depending on the chemical structural .
formula or the solubility of the aromatic nitrile-modified prepolymer in organic solvents; nl is either O or greater than 1, n2 is a positive integer greater than L, and the sum of nl and n2 is an integer from 1 to 50; Rl, R2, lS R3, and R4 are aryl radicals, heterocyclic radicals, particularly those :heterocyclic radicals containing one, two, or three nitrogen atoms in the ring, .
or combination of both aryl and heterocyclic radicals; ~n prepolymer (IV), R
and R2 in the brackets followed by the subscript nl cannot contain a nitrile group, whereas Rl and/or R2 in the brackets followed by the subscript n2 -13- .

'' . '' ' , " ' '' ' ' .,:, ' ,, ' ' " ' ',' .': ' ' ' ' ' .''', ', ' ', . ", ' .': ' -. ~ 106869~
. must contain a nitrile group; and in the preferred embodiments Rl is a tetraval t aromatic radical selected from thc group consisting of:

~1 y~

' ~X
': : , ~1 ,, ....
l ~ Y ~XI ~ Y ~_ ~
, Xl '.

R2 is a bivalent aromatic radical selected from the group consisting of:

l ~ ~X~
~:~ ; Xl . , , l ~ XI -~ Y ~XI

` X2 ' _ X2 l I [~
. "`.' -14- :

' '' ~ ' ~a~s6s6 ..
~ ~ ::
Xl and X2 are monovalent radicals selected from the group consisting of -H, -CN, ~ Cl, -Br, -N02, -CH3, and ~, where Xl may or may not be the same group as X2, and X may be either Xl or X2;
Y is a bivalent radical selected from the group consisting of: -~
CN CN C~
-O-, -C-, -S-, -S-, -S02-, -CH2, Xl--C--X2, ~¢-Xl and g~C~

: Zl and Z2 are monovalent radicals selected from the group of: hydroxyl, ~:.
alkyoxyls, aroxyls, and halides3 where Zl may or may not be the same group as Z2~ and Z may be either Zl or Z2; nitrile (VII) is an aromatic nitrile .`;selected from the group consisting of:

CN CN CN
H2N ~ H2N {~ x~l CN CN
Ei~N~ ~1 ti2N ~ ~

¦¦ nitrile (-III ) is an aromatic nitrile selected from the group consisting of: o X CN O CN

¦ ~C ~ ~ CN ~ , 0~
X O=C~O/C= X ; '' ~ O ~N

and nitrile (VIIlb) is the derivative of aromatic nitrile (VIIIa), wherein the -15- :
,. .

,. . . . . . . : ..
.. . . . . . . . . . . . ..
: . '.. . , .. . : . : ' ' ~ ~ 61!3696 dicarboxylic acid anhydride moiety becomes either a diaaid, a dicster, a halfester or a dicarbonyl halide having the two carboxyl or carbonyl groups in the ortho positions on the aryl ring.
The symbol [~ as used herein indicates that the two ring substituent groups are in ortho positions or neighboring to each other.
It has been found, in accordance with the present invention, that the novel processable aromatic nitrile-modified imide prepolymers disclosed above can be catalytically trimerized using the novel process of the present invention to form high molec~lar weight aryl-s-triazine ring containing polyimides which exhibit outstanding thermal-oxidative stability and high performance structural properties. These novel aromatic nitrile-modified imide prepolymers are readily processable into filler-reinforced composites by the inclusi~n of suitable fillers, such as those discussed hereinbefore, in the reaction mixture during the catalytic trimerization process. The novel flller-reinforced composites made from the novel processable aromatic nitrile modified imide prepolymers may be fabricated into useful articles for indus-trial and household applications which require a great degree of stability to thermal oxidation as well as excellent mechanical properties at elevated temperatures. The novel filler-reinforced composites of the present invent-ion can be used as structural materials in a number of aeronautical and aerospace applications.
The polybenzimidazole class of polymers find wide utility in numerous areas of applicatlon in the form of shaped articles which effectively utilize their highly stable nature. They are particularly useful in the form of films and fibers which show great resistance to degradation by heat, hydrolytic medi and oxidizing media. Fibers of the polymers are of value in numerous textile ;
. ' " ' ~

-16- ~
:. .
:.

- .. . . . . . .. . . . . .. . . .

~ __ ~ . _ ., ^-;~ ` ` 1~6~36~6 .` ` . :',"
and industrial uses, and may be woven and knit into fabrics which will retain their properties for extended periods even in uses where other fibers rapidly deteriorate. Films of the polymers are useful in covering and protective agents, even in locations where corrosive conditions prevail. Conventional polybenzimidazoles, however, are difficult to process, with or without filler-reinforcement. According to the present invention, novel aromatic nitrile-modified (terminated and/or appended) benzimidazole prepolymers are pro-duced which may be trimerized to form new triaryl-s-triazine ring cross-linked polybenzimidazoles which possess the outstanding thermal stability of both polybenzimidazoles and triaryl-s-triazines.
The novel processable aromatic nitrile-modified benzimidazole prepoly-mers made in accordance with the present invention have one of the following four general structural formulas:
X~ ~ ~X 1~;~ "~ ~ ~ CI

NC~ 3 ~ ~N~ l~N~C R2 C~ ~N~l\N~ 3~X
_ _ n X~ ~ _ _ ' ~X , lS (X) ~R4 , ~~ ~ ~ 1~, ~C--R2--C~ ~R4~
NC ~N' N N' n N' X

X~ ,N~/N~ _ ~X /
( NC~ 3 ~ ~N~ l~N~C--R2--C~ ~N~R4~X
_ n ¦¦ (XII) ~ B/ 66C--R2 C,~ E~/N~C--R2--C~

nl n2 .. : ~ ,. ' , , : ' . . ..

~l ~ ` 1~6869/~
which is the reaction product of a dicarboxylic acid or its derivatives having the structural formula: .

-~- (XIII) Z--C--R2 C--2;, a tetra-amine having the structural formula:

~XIV ) R 1 .
XHN~ \NH2 , with a nitrlle having one of the following structural formulas, if prepolymer (IX), (X) or (XI) is to be made:
~ , ' . : ~
O ~ CN (XVI ) H 2N~ R / CN ~: -~X XHN~ ~X
or without a nitrile if prepolymer (XII~ is to be made, 10~ wherein n is an integer from 0 to 50, depending on the chemical structural : formula or the solubility of the aromatic nitrile-modified prepolymer in organic solvents, nl is either 0 or greater than 1, n2 is a positive integer greater than 1, and the sum of nl and n2 is a integer from 1 to 50; Rl, R, : . ~
R3, and R4 are aryl radicals, heterocyclic radicals, particularly those :;
15; ~ heterocyclic radicals containing one, two, or three nitrogen atoms in the ring, t `~
or combination of both aryl and heterocyclic radicals; in prepolymer (XII), R
and R2 in the brackets followed by the subscript nt cannot contain a nitrile : group, whereas Rl and/or R2 in the brackets followed by the subscript n2 :
must contain a nitrile group; and in the preferred embodiments Rl is a tetravalent aromatic radical selected from the group consisting of: : ;

~ , . . ~
. .
. . ' , ,, : , .

f, ~` ~068696 ~X~
~X~, ~'1' -X~' ~-~x~ rY~' ' ~ ~;

~ R2 is a bivale aromatic r~dlcal selected from th~ group consi~ting o-: ~

~ ' ~XI ~1 ;

~` ~ , Xl .
~ ~ J-~xl ~Y~XI
.

~ ~2 [~ ~2 Xl . ,1 , ~ nitrile (XV) i n eromat~c nitrlle s~ected from the group consi~ting o-:

. : , , ; ~, ,, ,, . , , "; ,..................... .
.

~ ~ ` ~l~)6869~6 ~ ` ~ ' ¦ ~N ~'N

nitrile (XVL) is an aromatic nitrile selected from the group consisting ol~

~CN ~CN

5XHN~1 XHN~ ~
X X
Xl and X2 are monovalent radicals selected from the group consisting of -H, ~ :
-CN, -F, ~C1J -Br, -NO2, -CH3, and ~ j where X1 may or may not be ..
the same group as X2, and X may be either Xl or X2;

Y is a bivalent radical selected from the group consisting of:
CN CN CN
O C- -S- -~ SO2-, -CH2, Xl--C--X2, ~C Xl an ~ I ~;

and Z is a monovalent radical selected from the group consisting of: hydroxyl, alkyoxyls, aroxyls, and halides.
It has been found, in accordance with the present invention, that the novel processable aromatic nitrile-modified benæimidaxole prepolymers disclosed above can be catalytically trimerized without the evolution of by-products using the novel process of the present invention to form high mole-cular weight aryl-s-triazine ring containing polyl~enzimidaz.oles.
.,, . ~ , . , : . ., .,, ,., , . ~: . : ,, , :, .

' ~ , ~ _ __ _ i~6~6g~
~ ~ ~ :`
These novel polybenzimidazole resins find utility as pressure adhesives and composites to form articles which are free of voids and which exhibit gooc thermal-oxidative stability and high performance structural properties.
These novel resins are readily processable into filler-reinforced composites by the inclusion of suitable fillers in the reaction mixture during the catalytic trimerization process as noted above.
The class of polymers known as the polyimidazopyrrolones are known to possess a high resistance to thermal and radiative energy as well as excellent mechanical properties of shaped articles made from the polymers. They also display outstanding resistahce to organic chemicals as well as a remarkable resistance to the action of strong aclds and bases. Conventional polyimi-dazopyrrolones, however, are extremely difficult to process, with or without fiber reinforcement. According to the present invention, novel aromatic nitrile-modifièd (terminated and/or appended) imidazopyrrolone prepolymers are disclosed which may be trimerized to form new triaryl-s-triazine ring containing polyimidazopyrrolones, which possess the good thermal stability of both polyimidazopyrrolones and triaryl-s-triazines.
The novel processable aromatic nitrile-modified imidazopyrrolone prepolymers made in accordance with the present invention have one of the following four general structural formulas:

'. '' ' ' ' , . ' .. " ' ' . ' . ', ', ' ' ' . ": ,' ' ' :- , . . , . , . ,: , . , ., . , , . " .:

~ 106~696 ~ ~

X\ / ~ /R/ ~C~ ~C~ ~R/ ~C~ /CN

(XVIII ) NC~E4 ~ ~ ~R/ ~N~ I\N \RI/ ~N~ \X

; R/C~ ~RI/ ~C~ ~ /CN

~: ~ ' (XX) :.

I N~ \N'' ~Rl~ ~ N~ 1`~ ~R

S which is the reaction product of a tetracarboxylic acid dianhydride (XXIa), or its derivatives (XXIb) having the structural formulas:

(XXla) O\ ,Rl~ ~o , (XXlb) C~RI~ ~ :

a tetra-amine having the structural formula:

H2N~ ~ N~2 ,:
~2N~ ~NH2 . ., -22- , .

~~ ~ )61~696 .' , , ,' ' .' ..
with a nitrile having one of the following fitructural formulas, if prcpolymer (XVII), (XVIII) or (XI~) is to be made:

~C~ /CN Zl--C~ CN
~R4~x , (XXIIIb) R ~
O O .

~: ~ 4 .
H2N \X .
~: . . ~
; or without a nitrile if prepolymer (XX~ is to be made, wherein n is an integer from O to 30, depending on the chemical structural formula or the solubility of the aromatic nitrile-modified prepolymer in : orgamc solvents; nl~ is either O or greater than 1, n2 is a positive integer :
greater than 1, and the~sum of nl and n2 i9 an integer from I to 50; Rl and R4 are aryl radicals, heterocyclic radicals, particularly those heterocyclic radicals containing oneJ two or three nitrogen atoms in the ring, or combinat-ion of both aryl and heterocyclic radicals; in prepolymer ~XX), :Rl in the ~r, ~:~ brackets followed by the subscript nl cannot contain a nitrile group, whereas Rl.in the brackets followed by the subscript n2 must contain a nitrile group;
: lS and in the preferred embodiments Rl is a tetravalent aromatic radical ~: ~ selected from the group consisting of:

. -, . , . ''' ',.' . ... .. . ,,, . , ~,. ~. , . . ; ,. . .. ...
,: . . :. ", ,. .... . . : . " ., . , , ~ : ...
, : ". ~ , " , . . ,, ,. , . ,, , , , , ... .. , ,; , , .

`~_ ~ ~ 106~696 ~J x ~XI, ~ , X, ~ Y ~ , nitrlle (~XIIIa) is an aromatic nitrile selected from the group consisting of: :

~C 1~ CN ~ ~CN

~ ~N 0~ ~N

n~trile (~IIIb) is the derivative of aromatic nitrile (XXIIIa), wherein the dicarboxylic acid anhydride moiety becomes either a diacid, a diester, a halfester or a dicarbonyl halide having the two carboxyl or carbonyl groups in the ortho positions on the aryl ring; nitrile (XXIV) is an aromatic . .

-2~- ~

... , ... ,.,-,.. . . ............ . . ...................... .
, ., - . . ' , ""

~: ~ 68696 .
¦ nitrile selected from the group consisting of:

H2N l~- [~1 H2N~ .

¦~ NH2 NH2 X :
¦H2N CN H2N CN ~:
~H2N~J ~ H2N ~ ~

I~ X :~ ~
¦ Xl and X2 are monovalent radicals selected from the group consisting of -H, I .
¦ -CN, -F, -Cl, -Br, -N02, -CH3, and ~), where Xl may or may not be :::
¦ the same group as X2, and X may be either Xl or X2; ~ ;~ .
Y is a bivalent radical selected from the group consisting of: .:
CN CN CN
, , S, S02, -CH2~ Xl C--~2~ ~ C--Xl and ~C~
:~ : ¦ and Zl and Z2 are monovalent radicals selected from the group consisting of: ~ ~ .
¦ hydroxyl, alkyoxyls, aroxyls, and halides, where Zl may or may not be the -: `
¦ same group as Z2' and Z may be either Zl or Z2' I It has been found, in accordance with the present invention that the novel :: ¦ processable aromatic nitrile-modified imidazopyrrolone prepolymers dis-; ¦ closed above can be catalytically trimerized without the evolution of by-pro-¦ ducts using the novel process of the present invention to form high molecular :
¦weight aryl-s-triazine ring containing polyimidazopyrrolones. These novel ¦polyimidazopyrrolone resins also find utility as pressure adhesives and ¦ composites to form articles which are free of voids and which exhibit ¦ outstanding thermal-oxidative stability and high performar~ce structural ~properties, These novel resins arc readily processable into filler-reinforced l -25- ~ I .
I , .: ~

,~ , , , " , , , . ::
. . . . ..

~ 1~68696 ¦ composites b.y the inclusion of suitable fillers in the reaction mixture during ¦ the catalytic trimerization process as noted above.
¦ The class of polymers known as the polyquinoxalines are also known to ¦ possess a high resistance to thermal energy as well as excellent mechanical ¦ properties of shaped articles made from the polymers. Conventional ¦ polyquinoxalines, however, are also difficult to process, with or without filler .
¦ reinforcement. According to the present invention novel aromatic nitrile-¦ modified quinoxaline prepolymers are disclosed which may be trimerized to form new processable polyquinoxalines which possess the good thermal:
~10 l stability of both polyquinoxalines and triaryl-s-triazines.
The novel processable aromatic nitrile-modlfied quinoxaline prepolymer made in accordance with the present invention have one of the following four ¦ general structural formulas:
~ ' I X ' . .

~ " ,~

1~N N~ --~

(XXV~ R ~N~R2~N~R/CN

(XXVI~ R ~--R2~ R1~ ~; R2 .
'. ,.

--~
` 1~:?6~696 -:
.`.''' . ,~
which i9 the.reaction product of a diglyoxal having the structural formula:
~; " O, (XXIX ) A--C--C--R 2 C--C--A , a tetra-amine having the structural formula:

(XXX) H2N\ / NH2 : ~-. H2N~ l \NH2 -S with a nitrile having one of the following structural formulas, if prepolymer :
(XXV), (XXVI) or (XXVII) is to be made: ~ : ."~ , ~XXXI) H2N\~, j , (XXXII) A C C~CN

or without a nitrile if prepolymer (XXVIII) is to be made, wherein n is an integer from O to 100, depending on the chemical structural ; formula or the solubility of the aromatic nitrile-modified prepolymer in : .
organic solvents; nl is either O or greater than 1, n2 is a positive integer greater than 1, and the sum of nl and n2 is an integer from 1 to 100; Rl, R2, and R4 are aryl radicals, heterocyclic radicals, partieularly those heterocyc-lic` radicals eontaining one, two, or three nitrogen atoms in the ring, or a eombination of both aryl and heteroeyclic radicals; in prepolymer (X~VIII), Rl and R2 in the brackets followed by the subseript nl cannot contain a nitrile group, whereas Rl and/or R2 in the braekets followed by the subscript n2 must contain a nitrile group; and in the preferred embodiments Rl is a tetravalent aromatic radical selected from the group consisting of: .:

~- 11;36l~ 6 , ~X

'~X~' ~X~

;~ ~ R2 19 a bi alen~ aroma~ic ra lic~l selected from the group ~onsiYting of:
5 ~ ~ XI ~XI I

, ~ X~ , ~ ~ I ~XI ~Y~XI
~, . ' , .

~1 ~ ' X~ ~ : , ' , . ,, , ., .,:
. . . .
.... . . . . .
.

~ . 1068~i96 ~
nitrile (XXXI) is an aromatic nitrile selected from the group consisting of:
. ' ' :
." X CN H2N CN

2N ~ ~ ,~ H2N

H2N~ ~ H2N~

.Xl and X2 are monovalent radicals selected from the group consist~ng of .-H, .j;
-CN, -F, -Cl, -Br, -N02, -CH3, and ~, where Xl may or may not b ..
the same group as X2, and X may be either Xl or X2; ~ .
Y is a bivalent radical selected from the group consisting of:

CN :
~: -O-, -C-, -S-, -S-, -S02, -CH2, Xl--C--X2? .~(~--Xl and . :. CN CN
~C~); and A is a monovalent radical selected from the group ~-.;

consisting of: -~1, ~, ~, ~ ~ ~

(~ ~ ~ ~5 ~ ~ ;

It has been found, in accordance with the present invention,that the novel processable aromatic nitrile-modified quinozaline prepolymers dis-closed above can be catalytically trimerized without the evolution of by-products using the novel process of the present invention to form high molecular weight aryl-s-triazine ring containing polyquinoxalines. These 1~6l!369~
novel polyquinoxaline resins also find utility as pressure adhesives and article-forming composites which e~hibit good thermal-oxidative stability and high performance structural properties. These novel resins are readily pro-cessable into filler-reinforced composites by the inclusion of suitable fillers ln the reaction mixture during the catalyt1c trimerization reaction process as noted above.
As described above, the four classes of polymers known as polyimides, polybenzimidazoles, polyimidazopyrrolones, and polyquinoxalines are known to possess a high resistance to thermal energy as well as excellent mechani-cal properties of shaped articles made from the polymers with or without filler reinforcement. According to the present invention novel aromatic nitrile-modified (terminated and/or appended) precopolymers made from combinations of the four classes of prepolymers are disclo.sed which may be trimerized to form novel processable copolymers which possess the good thermal stability of these four classes of polymers and triaryl-s-triazines.
The novel precopolymers are made by combining two, three or four of the classes of prepolymers disclosed above.
The novel processable aromatic nitrile-modified precopolymer combinations of imidej benzimidazole, imidazopyrrolone and quinoxaline prepolymers are made by selecting appropriate monomeric reactants set forth in Table II below and appropriate terminating nitrile reagents set forth in Table III below.
. ',, , .

.. .. .. .. . .
.. - . .

. .

, ~ 6~3696 ¦ TABLE II :
HIGH T13MPERATURE RESISTANT POLYI\IERS .
. _ _ .
Polymer I\~onomeric ReactantsLinkage \C~ ~

5~ Imides or +H2N--R2--NH2 /C\N--. Z2 C~ /C Z
zl cl~ ~o-z2 ~
-~ - ~ - ~

O O, H N NHX /N
Benzimidazoles Z C R2 C Z +2 ~R/ C-- . .

. . ~HN~ l~NH2 ~N~
'O O _ . __ , i . O~ ~R / \O s ~ Imidazopyrrolon~s or + R/ 2 /C/
~ IO O ¦ 2 2 1 ~ Z~ C~-Z2 . . ,~
I ~ .. __ _ . _ ._ -Quinoxaline s A--C--C--R2--C~--A + R 1 ~N~_ H2N~ ~NH2 N A

_. . '.:' -31- :
, ., ..

~`~` ~ 1068696 ¦ TABLE III :

¦ TERMINATING OR END-CAPPING NITRILE REAGENTS
~ . . -I Nitrile Reagent L - .
I .

H2N R3 ~X

O ~ , O~ ~ R/ , Z i C\R/ ~
I O O
.. _ - ~ ~ ; , I . ._ .. ..... __ ,R4\ ~ XHN~ 4\X ¦ :

A - ---- C--C ~

.. - - ------ - - -¦ As will be readily apparent to those skilled in the art, the novel `
¦ aromatic nitrile-modified precopolymer combinations can be easily formulat-ed by selecting appropriate monomeric reactants and terminating nitrile reagents from two, three or four of the classes of novel processable aromatic nitrile-modified prepolymers disclosed above.

.. .~ . .

i~6B696 For example, a novel processable aromatic nitrile-modified imide-- imidazopyrrolone precopolymer made in accordance with the present invention can have the structural formula:

(XXXIII ) S ~ ~R3--N /R/ ~N--R~ N~ ~R~ \N~ ~j :

a novel processable aromatic nitriIe-modified quinoxaline-benzimidazole . precopolymer made in accordance with the present invention can have the structural formula: :

(XXXIV ) ~ [ R2¦,~R/ D~ 2 C~R4~X

a novel processable aromatic nitrile -modified imide -imidazopyrrolone - - ::
quinoxaline precopolymer made in accordance with the present invention can have the structural formula:
~ , ."' ; (XXXV) ~ :' X~ ¦C~ /C~ ~R~N~ ~ 4\X

a novel processable aromatic nitrile-modified imide-imidazopyrrolone_ quinoxaline-benzimidazole precopolymer made in accordance with the : :
present invention can have the structural formula:

(XXXVI) X : .

~ ~R~ 2~ / C--R2 C$"

and so forth, -33- .
. ~ , : ., -, . . . ~ .. .
.. . . . .
, . . . . . . . . . . .
., ~. . ~, , . , . , ", , .

-_ `` ~L~6869~;
wherein n is an integer from 1 to 50, depending on the chemical structural formula or the solubility of the aromatlc nitrile-modified precopolymer in organic solvents.
It has been found, in accordance with the present invention that the novel processable aromatic nitrile-modified precopolymers of various combinations disclosed above can be catalytically trimerized without the evolution of by-products using the novel process of the present invention to form high molecular weight corresponding triaryl-s-triazine ring cross-linked copolymers, These novel copolymer resins also find utility as pres-sure adhesives and composites to form articles which are free of voids and which exhibit outstanding thermal-oxidative stability and high performance structural properties. These novel resins are readily processable into filler reinforced composites b~ the inclusion of suitable fillers in the reaction mixture during the catalytic trimeri~ation process as noted above.
Furtherj in accordance with the present invention, it was found that certain aromatic dinitrile compounds including aromatic nitrile end-capped methylene, phenylene, arylether, arylsulfide, arylsulfone, arylketone, siloxane prepolymers and their precopolymers can be catalytically trimerized according to the novel process of the present invention to form novel poly-meric products containing triaryl-s-triazine rings which exhibit good thermal oxidative stability.
The processable aromatic dinitrile compounds which may be catalyti-cally trimerized in accordance with the present invention consist of the follow ing:
X ~ 'X XX X X X X X
2 5 NC~CN, NC-~CN, NC~ ~-CN
X ~ X X X X' X X X X .

-3~-: .... . . . . . . . .

. / . ~C~68696 wherein Y is a bivalent radical selected from the group consisting of:
CN CN CN
-O-, -C-, -S-, -S-, -S02~, X~ X2, ~ I -Xl, ~C~, -~CH2)-, -(CF2)-, and ~(CF2-CFCl)nl, where nl is an int g ~ and ~ , ~o~ , ~St ~S2~ ~ C~

(--- Si-O )n ~ and combinatior~s thereof, where n2 is an integer from 1 to :
X ,~:~
about 100: and X is a monovalent radical selected from the group consisting of-H, -F, -Cl, -Br, N02, -CH3, and ~ .
These novel polymeric products containing triaryl-s-triazine rings also ~ :
nnd utility in filler-reinforced composites of high thermal-oxidative stability and high performance structural properties which are useful as structural materials in a number of aeronautical and aerospace applications.
A more complete appreciation of the invention will be realized by reference to the following specific examples relatlng to specific compounds and polymers and the processes for preparmg them, The following examples .:
are not intended to lim~t the invention disclosed herein except to the extent that limitations are specifically stated or to the extent to which limitations ..
appear in th ppended claims, . .

;~

' .' ' ", ' , , , ' ' .',". ;

~ 1~68696 Benzonitrile in the amount of 0. 01 mole was mixed with 5 mole per cent of p-toluenesulfonic acid monohydrate and introduced into a 45 milliliter stainless steel pressure vessel equipped with a 1000 p, s. l, pressure gauge, a 1000 p. s. i. burst disc and a needle valve. The pressure was then brought up to 600 p. s. i. by introducing compressed nitrogen into the vessel and the temperature was raised to 232 C, for a period of 48 hours. The product was then separated from the unreacted nitrile and the catalyst and recrystallized from a suitable solvent. The product obtained was analyzed by infrared and its melting point was determined to be 232-235 C. The per cent yield, i. e.
per cent of converted nitrile which is triazine, was found to be 14 per cent.

IJsing the apparatus described in Example 1, 0, 01 mole of cyanobenzoic acid was mixed with 5 mole per cent of p toluenesulfonic acid monohydrate.
The mixture was heated at 232 C. and 750 p. s. i. for 48 hours. The product was then separated from the unreacted nitrile and the catalyst and recrystal-lized from glacialacetic acid. The product was analyzed by infrared and its melting point was determined to be ~340C. The percentage of yield was found to be 75 per cent.

p-Cyanophthalanil, [N-(4-Cyanophenyl)phthalimide], was prepared from p-aminobenzonltrile and phthalic anhydride. p-Cyanophthalanil is a white crystalline powder having a melting point of 189C. (lit. 187C. ). Its infraredspectrum showed a nitrile band at 2240 cm , imide bands at 1795, 1775, 1735, and 1380 cm 1, and aromatic ring bands at 1610 and 1520 cm 1 respect fully. Catalytic trimerization of 0.01 mole of p-cyanophthalanil with 5 mole .. - . ,.. , .. , .. ,, ., .: . . ., . .: . :

=
~- ~ ~
10~;8696 `. . ; , , per cent of p-toluenesulfonic acid monohyarate using the apparatus described in 13xar~ple 1 at 250 to 300C. and 720 to ûO0 p. s.i. for 90 hours gave a product (97 per cent yield), m. p. ~340OC. The infrared spectrum of the trimerlzed product showed that the band at 2240 cm 1 had disappeared and the bands at 1520 and 1380 cm-l broadened indicating the formation of s-triazine rings.

Using the apparatus déscribed in Example 1, 0. 01 mole of terephthalo- -nitrile, m.p. 231C., was heated with 5 mole per cent of p-toluenesulfonic acid monohydrate at 232C. and 750 p.-s. i. for 48 hours gave a product :
(99. 5% yield), m. p. ~340OC. The infrared spectrum of terephthalonitrile ; showed a very strong nitrile band at 2230 cm~l and a sharp aromatic ring band at 1500 cm~l, while the infrared spectrum of the trimerized polymeric product showed strong and broad chracteristic s-triazine ring bands at 1525 and 1370 cm~l with a residual nitrile band of medium strength at 2230 cm~l.
Thermal gravimetric analysis showed that the weight losses of the triaryl-s-triazine ring cross-linked polymeric product were about 7 per cent after heating to 316C, and 18 per cent after heating to 53ûC.

E~AMPLE 5 In a 100 milliliter glass flask, 9. 27 grams (0,00302 mole) of 3, 3', 4,

4'-benzophenonetetracarboxylic dianhydride was heated with 29 grams of anhydrous methanol until a clear solution was obtained. After cooling, 4. 02 grams (0. 00202 mole) of 4, 4' -methylenedianiline, 2. 36 grams (0.00200 mole ) of p-aminobenzonitrile, and about 0.1 gram (about 0. 25 mole per cent on basis of the nitrile content) of p-toluenesulfonic acid monohydrate were l ~
1~68696 I; ' ' .
introduced with stirring until all was dissolved. This clear solution of mono-meric r~eactants was transfered to the apparatus descrlbed in Example 1, ¦ e~cept that the lid was not installed at this time. The open vessel was heated I gradually to about 100C. so that most of the methanol and some of the by-I products (methanol and water) would evaporate off. The reaction vessel was ¦ then installed with the lid and heated under reduced pressuré at a temperature ¦ up to about 200C. until no more methanol and/or water came off. The ves-¦ sel was then filled with dry nitrogen gas and adjusted to a pressure in the I range of 400 to 800 p. s. i. and heated at temperatures in the range of 200 to ~' .
1 350C. for 8 hours. The polymeric product presumed to be triaryl-s-trazine , ring cross-linked polyimide was found to be very hard and dark brown in color. It did not melt when heated up to 340C.
.

The clear solution of monomeric reactants prepared according to the method described in Example 5 was used to make prepregs by drum winding and impregnating Hercules HMS graphite fiber in a resin/fiber content of about 40/60 by weight~ The prepregs were heated from 50 to 120C. for a couple of hours to reduce the solvent content to less than 10 per cent by weightPlys of partially imidized prepregs were then stacked between aluminum foil and heated in an oven at 200 to 250C. for several hours for complete imidi-zation. The imidized prepregs were then placed in a mold and trimerized at 200 to 350C. and under pressures in the range of 200 to about 1000 p. s. i.
for several hours. The prepregs may be further post cured in an oven at about 300 to 350C. from several hours to se~eral days.

, . . . . . . . .. . .

^ -`- ` 1~68696 EX~M PLE 7 ~Jsing the apparatus and procedure of Example 5, a triaryl~s-triazine ring containing polybenzimidazole is prepared by reacting 22. 50 grams of a solvent mixture of methanol and N-methylpyrrolidone, 3. 22 grams of methyl-p-cyanobenzoate, 5. 99 grams of dimethyIterephthalate, 9. 88 grams of 3, 3', 4, 4'-tetraminobenzophenone, and 0.10 grams of benzenesulfonic acid.

E~AMPLE 8 Using the apparatus and procedures of Example 5, a triaryl-s-triazine ring cross-linked polybenzimidazole is prepared by reacting 22. 50 grams of a solvent mixture of methanol and N-methylpyrrolidone, 1. 33 grams of 3, 4-diaminobenzonitrile, 9, 65 grams of dimethyl-5-cyanoisophthalate, 8. 23 gram of 3, 3', 4, 4'-tetraminobenzophenone, and 0.15 grams of naphthalene ,~-sulfonic acid monohydrate.
.

lS Using the apparatus and procedure of Example 5, a triaryl-s-triazine ring cross-linked benzimidazole-imidazopyrrolone copolymer is prepared by reacting 22. 5~ grams of a solvent mixture of dimethylsulfoxide and N-methyl-pyrrolidone, 3. 46 grams of 4-cyanophthalic anhydride, 6. 42 grams of dimethyl-5-cyanoisophthalate, 9. 51 grams of 3, 3~, 4, 4~-tetraminoben~o-phenone, and 0.10 grams of benzenephosphenic acid.

~AMPLE 10 ~sing the apparatu.s and procedure of Example 5, a triazine ring con~ ;
taining polyimidazopyrrolone is prepared by reacting 5. 00 grams of methanol, 15. 00 grams of N, N-dimethyl formamide, 6.44 grams of 3, 3l, 4, 4~-tetra-minobenzophenone, 2. 66 grams of 3, 4-diaminobenzonitrile, and 0.10 grams of ferric acetylacetonate.

.. . .. . ....
, . . .. ,: . .
; ,, ' , :, , .. . . .

~ ~L~6~696 .`. ...

Using the apparatus and procedure similar to Example 5, a triazine ring cor~aining polyimidazopyrrolone is prepared by reacting 8. 76 grams of dimethyl-4-cyanophthalate, 4. 84 grams of 3, 3', 4, 4'-tetraminobenzophenone 10 grams of N-methylpyrrolidone, 10 grams of dimethylsulfoxide, and 0.15 grams of 2, 6-naphthalene-disulfonic acid.

Using the apparatus and procedure similar to Example 5, a triaryl-s-triazine ring cross-linked polyimidazopyrrolone is prepared by reacting ~, 8. 76 grams of dimethyl-4-cyanophthalate, 5. 32 grams of 3, 4-diaminobenzo-nitrile, 10 grams of N, N-dimethylformamide, 10 grams of N, N-dimethyl-acetamide, 0. 05 grams of p-toluenesulfonic acid, and 0. 05 grams of zinc acetylacetonate, ~ .
E~AMPLE 13 Using the apparatus and procedure similar to Example 5, a triaryl-s-triazine ring cross-linked polyimide is prepared by reacting 2, 01 grams of 4, 4'-methylenedianiline, 1. 33 grams of 3, 5-diaminobenzonitrile, 9. 27 grams of 3, 3', 4, 4'-benzophenonetetracarboxylic dianhydride, 15 grams of methanol, 15 grams of N-methylpyrrolidone, and about 0. 05 grams of p-toluenesulfonic acid monohydrate and 0. 05 grams of 3-nitrophenylphosphonic ~:
acid.

, .- . ,. , ., . ., , , ,,, ~ , 10686Y6 ~

Using the apparatus and procedure similar to Example S, a triazine ring containmg polyquinoxaline is prepared by reacting 20. OO grams of N-methylpyrrolidone, 4. 70 grams of p-cyanophenyl-glyoxyloylbenzene, 10. 2 S grams of 1, 4-bis(phenylglyoxaloyl) benzene, 9. 68 grams of 3, 3', 4, 4'-tetraminobenzophcnone, and 0.10 gram of p-toluenesulfonic acid monohydrate Using the apparatus and procedure similar to Example 5, a triazine ring containing quinoxaline-imidazopyrrolone copolymer is prepared by reacting 30, 00 grams of N,N-methylpyrrolidone, 3.46 grams of 4-cyano-phthalic anhydride, 9. 92 grams of 1,4-bis (phenylglyoxaloyl) benzene, 9.44 grams of 3,3',4,4'-tetraminobenzophenone, and 0.10 gram of 2,4,6-tri-methylphosphinic acid.
~ "`

Using the apparatus and procedure similar to Example 5, a triazine ring containing polyquinoxaline is prepared by reacting 30. 00 grams of N, N-methylpyrroliclone, 2. 66 grams of 3, 4-diaminobenzonitrile, 13O 22 grams of 1, 4-bis (phenylglyoxaloyl) benzene, 6. 92 grams of 3, 3 ~, 4, 4' -tetraminoben-zophenone, and 0.10 gram of zinc acetylacetonate.

2 0 ¦ EXAM PLE: 17 ¦ Using the apparatus and procedure similar to Example 5, a triazine ¦ ring cross-linked polyquinoxaline is prepared by reacting 4. 88 grams of p, p' -oxybis (p" -cyanobenzil), 2. 42 grams of 3, 3 ', 4, 4 ' ~tetraaminobenzo-¦ phenone, 0; 05 grams of naphthaléne-,~-æulfonic acid monohydrate, 0. 01 gram ¦ of p-toluencsulfonic acid monohydrate, in a mixture of 10 grams of xylene ¦ and 70 bramS of m-cresol.

I -41- ' I .

: , , . ,~ .

- --1C~686~6 EX~M :PLE 18 Using the apparatus and procedure similar to ~3xample 5, a triazine ring cross-linked polyquinoxaline is prepared by reacting 7. 84 grams (meta-or para ~) bis (p'~yanobenzoylphenoxyphenylglyoxaloyl) benzene N.C~ C~O~--C~C--C~O~C~CN, 2,42 grams of 3,3',4,4'-tetraaminbenzophenone, 0.05 gram of p~toluene-sulfonic acid monohydrate and 0. 01 gram of ferric acetylacetonate, in 50. : .
grams of m-cresol and 50 grams of xylene.

, . ~, ,,,., ~ ,, ~ . , ,

Claims (16)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A process for preparing an aromatic 1,3,5-triazine compound from an aromatic nitrile compound which comprises heating the aromatic nitrile to a temperature in the range of from about 100°C to about 700°C in the presence of a catalyst consisting essentially of a compound or mixture of compounds from at least one of the following groups: (A) organic sulfonic and sulfinic acids, (B) organic phosphonic and phosphinic acids, and (C) metallic acetylacteonates, at a pressure in the range of from atmospheric pressure to about 10,000 p.s.i.

2. The process of Claim 1 wherein the aromatic nitrile compound is heated to a temperature in the range of from about 100°C to about 500°C.

3. The process of Claim 1 wherein the aromatic nitrile compound is heated to a temperature in the range of from about 200°C to about 350°C.

4. The process of Claim 1 conducted at a pressure in the range of from about 50 p.s.i. to about 1000 p.s.i.

5. The process of Claim 1 conducted at a pressure in the range of from about 200 p.s.i. to about 750 p.s.i.

6. The process of Claim 3 conducted at a pressure in the range of from about 50 p.s.i. to about 1000 p.s.i.

7. The process of Claim 3 conducted at a pressure in the range of from about 200 p.s.i. to about 750 p.s.i.

8. The process of Claim 1 conducted in the presence of reinforcing filler material.

9. The process of Claim 1 wherein the aromatic nitrile compound is selected from the group consisting of meta-, ortho- and para-cyanobenzoic acid and their ester and halide derivatives.

10. The process of Claim 1 wherein the aromatic nitrile compound is selected from the group consisting of meta-, ortho- and para-aminobenzo-nitrile.

11. The process of Claim 1 wherein the aromatic nitrile compound is selected from the group consisting of 4-cyanophthalic anhydride and its ester and halide derivatives,

12. The process of Claim 1 wherein the aromatic nitrile compound is 3,4-diaminobenzonitrile.

13. The process of Claim 1 wherein the aromatic nitrile compound is 3,5-diaminobenzonitrile.

14. The process of Claim 1 wherein the aromatic nitrile compound has the following structural formula:
wherein X is a monovalent radical selected from the group consisting of -H, -CN, -F, -Cl, -Br, -NO2, -CH3, -NH2, -OCH3, and substituted aryls, and X may be substituted at the meta and para positions.

15. The process of Claim 1 wherein said nitrile compound is a dinitrile compound having one of the following three general structural formulas:
, , wherein Y is a bivalent radical selected from the group consisting of:

-O-, -?-, -S-, -?-, -SO2-, , , , -(CH2)?1, -(CF2)?1, and -(CF2-CFCl)?1, where n1 is an integer from 1 to 4, and , , , , and combinations thereof, where n2 is an integer from 1 to about 100;
and X is a monovalent radical selected from the group consisting of -H, -F, -Cl, -Br, -NO2, -CH3, and .

16. The process of Claim 15, effected in the presence of reinforcing filler material.