CA1218210A - Method for reinforcing perfluoroelastomer compositions - Google Patents
Method for reinforcing perfluoroelastomer compositionsInfo
- Publication number
- CA1218210A CA1218210A CA000436743A CA436743A CA1218210A CA 1218210 A CA1218210 A CA 1218210A CA 000436743 A CA000436743 A CA 000436743A CA 436743 A CA436743 A CA 436743A CA 1218210 A CA1218210 A CA 1218210A
- Authority
- CA
- Canada
- Prior art keywords
- perfluoroelastomer
- perfluoro
- vinyl ether
- tear strength
- mill
- 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
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
- C08J5/04—Reinforcing macromolecular compounds with loose or coherent fibrous material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
- B29C43/003—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor characterised by the choice of material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2027/00—Use of polyvinylhalogenides or derivatives thereof as moulding material
- B29K2027/12—Use of polyvinylhalogenides or derivatives thereof as moulding material containing fluorine
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
- B29K2105/06—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts
- B29K2105/12—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts of short lengths, e.g. chopped filaments, staple fibres or bristles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2227/00—Use of polyvinylhalogenides or derivatives thereof as reinforcement
- B29K2227/12—Use of polyvinylhalogenides or derivatives thereof as reinforcement containing fluorine
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2031/00—Other particular articles
- B29L2031/26—Sealing devices, e.g. packaging for pistons or pipe joints
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2327/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers
- C08J2327/02—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment
- C08J2327/12—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
Abstract
TITLE
METHOD FOR REINFORCING
PERFLUOROELASTOMER COMPOSITIONS
ABSTRACT OF THE DISCLOSURE
Fiber reinforced perfluoroelastomer parts having high multidirectional tear strength are prepared by blending the fiber with the elastomer, pulverizing the blend into a powder, and molding and press-curing the powder into the desired shape.
METHOD FOR REINFORCING
PERFLUOROELASTOMER COMPOSITIONS
ABSTRACT OF THE DISCLOSURE
Fiber reinforced perfluoroelastomer parts having high multidirectional tear strength are prepared by blending the fiber with the elastomer, pulverizing the blend into a powder, and molding and press-curing the powder into the desired shape.
Description
TItrLE
I~ETHOD FOR REINFORCING
PER~LUORO~L,ASTOMER COMPOSITIONS
DESCRIPTIOM
Technical Fiel_ This invention relates to a method for reinforcing certain perfluoroelastomer compositions by incorporating therein by a particular process certain fibrous materials, thereby significantly improving the physical properties of the finished products made from such compositions. In particular, the invention relates to the preparation oE
reinforced perfluoroelas~omer parts wi~h high multidirectional tear strength. 5uch parts will be useful as seals, gaskets, diaphragms and liners wherever extraordinary resistance to heat and corrosive fluids is required, and especially where such parts require high multidirectional tear strength. This invention relates specifically to a method for preparing reinforced perfluoroelastomer parts wherein the reinforcing material is evenly and randomly dispersed in the perfluoroelastomer and is in intimate contact therewith, thus significantly improving the physical properties of the part evenly, equally and in all directions throughout the part.
Background Art Kalb et al., "Polymerization Reactions and ~ew Polymers", Advances in Che~istry Series, No. 129, 13-26 (1973) discloses certain copolymers of tetrafluoroethylene, perfluoro(methyl vinyl ether) and a third monomer selected from the group consisting of:
(a) perfluoro(4-cyanobutyl vinyl ether), (b) perfluoro(4-carbomethoxybutyl vinyl ether), AD-5234 35 (c) perfluoro(2-phenoxypropyl vinyl ether), and (d) perfluoro(3-phenoxypropyl vinyl ether), .
I~ETHOD FOR REINFORCING
PER~LUORO~L,ASTOMER COMPOSITIONS
DESCRIPTIOM
Technical Fiel_ This invention relates to a method for reinforcing certain perfluoroelastomer compositions by incorporating therein by a particular process certain fibrous materials, thereby significantly improving the physical properties of the finished products made from such compositions. In particular, the invention relates to the preparation oE
reinforced perfluoroelas~omer parts wi~h high multidirectional tear strength. 5uch parts will be useful as seals, gaskets, diaphragms and liners wherever extraordinary resistance to heat and corrosive fluids is required, and especially where such parts require high multidirectional tear strength. This invention relates specifically to a method for preparing reinforced perfluoroelastomer parts wherein the reinforcing material is evenly and randomly dispersed in the perfluoroelastomer and is in intimate contact therewith, thus significantly improving the physical properties of the part evenly, equally and in all directions throughout the part.
Background Art Kalb et al., "Polymerization Reactions and ~ew Polymers", Advances in Che~istry Series, No. 129, 13-26 (1973) discloses certain copolymers of tetrafluoroethylene, perfluoro(methyl vinyl ether) and a third monomer selected from the group consisting of:
(a) perfluoro(4-cyanobutyl vinyl ether), (b) perfluoro(4-carbomethoxybutyl vinyl ether), AD-5234 35 (c) perfluoro(2-phenoxypropyl vinyl ether), and (d) perfluoro(3-phenoxypropyl vinyl ether), .
2~L~
Kalb et al also discloses the outstandiny solvent and chemical resistance that can be obtained with these elasto~ers.
U.S. Patent 3,546,186 granted De-ember 8, 1970 to Gladding and Sullivan, discloses certain vulcanizable copolymers of substituted perfluorovinyl ether. In particular,~ among the many and varied copolymers disclosed by Gladding and Sullivan, there are disclosed terpolymers derived from tetrafluoroethylene, perfluoromethyl perfluorovinyl ether and a cure-site monomer which can be, a~ong other things, perfluoro(4-cyanobutyl vinyl ether) or perfluoro~4-carbomethoxybutyl vinyl ethe~).
U.S. Patent 3,46~,638, granted September 16, 1969 to Pattison, discloses certain vulcanizable copolymer~ of substituted perfluorovinyl ether. In particular, among the many and varied copolymers disclosed by Pattison, there are disclosed terpolymers derived from tetrafluoroethylene, perfluoromethyl perfluorovinyl ether and a cure-site monomer which can be, among other things, perfluoro(2-phenoxypropyl vinyl ether).
U.S. Patent 3,682,872, granted August 8, 1972 to Brizzolara and Quarles, discloses certain vulcani~able copolymers of substituted perfluorovinyl ether. In particular, among the many and varied copolymers disclosed by srizzolara and Quarles there are disclosed terpolymers derived from tetrafluoroethylene, perfluoromethyl perfluorovin~l ether and, as a cure-site monomer, perfluoro(3-phenoxypropyl vinyl ether).
U.S. Patent 4,281,092, granted July 28, 1981 to Breazeale, discloses certain vulcanizable copolymers of tetrafluoroethylene, perfluoro~ethyl perfluorovinyl ether and a cure-site monomer ~hich can be perfluoro(8-cyano-5-methyl-3,~-dioxa-1-octene).
U.S. Patent 4,035,565, granted ~uly l2, 1977 to Apotheker et al. discloses, among other thincls, certain vulcanizable copolymers o~ up to 3 mole percent of a bromine containing olefin, tetrafluoroethylene, and a perfluoroalkyl perfluorovinyl ether.
Perfluoroelastomer compositions based on the polymers disclosed in the back~round art summarized above can be improved by the incorporation of fibrous materials therein by the process of the present lnventlon .
Disclosure of the Invention The present invention relates to a method for reinEorcing certain vulcanizable perfluoroelastomer compositions, wherein the perfluoroelastomer is preferably a terpolymer derived from tetrafluoroethylene, perfluoromethyl perfluorovinyl ether and a cure-site monomer, thus permitting the manufacture of finished perfluoroelastomer parts with high multidirectiona]
tear strength as compared with unreinforced perfluoroelastomer parts or perfluoroelastomer parts reinforced by conventional techni~ues.
The terpolymers used in the parts made by the process of the present invention are substantially as described by Kalb et al, Gadding and Sullivan, Pattison, Brizzolara and Quarles, Breazeale, and Apotheker et al. in the references cited above and generally comprise copolymerized units of about 53-79.8 mole percent of tetrafluoroethylene (TFE), about 20-45 mole percent of perfluoromethyl perfluorovinyl ether (PMVE), and 0.2-2 mole percent of a cure site monomer selected from the group consisting of:
2 '1 ~
, ~ ~
(a) perfluoro(4-cyanobutyl vinyl ether), (b) perfluoro(4-carbomethoxybutyl vinyl ether), (c) perfluoro(2-phenoxypropyl vinyl ether), (d) perfluoro(3-phenoxypropyl vinyl ether), (e) perfluoro(8-cyano-5-methyl-3, 6-dioxa-1-octene), and (f) a bromo-containing olefin.
Such terpolymers can be prepared by the procedures taught in the references cited above. Preferably the compositions of the present invention are based upon terpolymers in which the cure-site monomer is perfluoro(2-phenoxypropyl vinyl ether), or perfluoro(8-cyano-5-methyl-3,6-dioxa-1-octene) and most preferably, they are based on such terpolymers in which the proportions of the monomers are about 65.4-73.6 mole percent TFE, 26-34 mole percent PMVE, and the remainder is perfluoro(2-phenoxypropyl vinyl ether) or perfluoro (8-cyano-5-methyl-3,6-dioxa-1-octene~. It should be understood that exact determination of the monomer proportions is difficult and that the values given are estimates based on infrared spectra.
As with conventional vulcanizable fluoroelastomer compositions, it is frequently desirable to mix fillers such as carbon black or one or more non-black fillers, such as titanium dioxide, -~
~z~
zirconium ~ioxide, 5ilica, clay and asbes~os, reinforcing ayents, stabilizers, plasticizers, lubricants or processing aids with the elastomer prior to vulcanization.
Typical reinforcing agents include polytetrafluoroethylene (PTFE) and copolymers of hexafluoropropylene and tetrafluoroethylene.
Fibriles of fibrillated PTFE are especially preferred where increased tear strength is required without any significant sacrifice in resistance to environmental attack or in resistance to heat and corrosive fluids. Such reinforcing agents are typically incorporated into the uncured perfluoroelastomer by blending the reinforcing agent and any other desired compounding ingredients with the perfluoroelastomer on a rubber mill at controlled temperature.
It has been found, however, that whe~
fibrillatable PTFE reinforcing agent is processed in the manner described above, a product results in which the tear strength perpendicular to the direction of milling ~the perpendicular direction) is significantly increased while tear strength parallel to the direction of milling (the initial direction) is not significantly increased. It is believed that this is due to oriantation of the reinforcing agent substantially parallel to the direction of milling.
In some end use applications, such as in diaphragms, improved multidirectional tear strength (i.e., tear strength in both the initial and the perpendicular directions) is important.
It has been found that such improved multidirectional tear strength can be achieved by the process of the present invention. In particular, it has been found that such results can be achieved by (1) preparing milled materials substantially as ~8~
descri~ed abo~e, (2) pulverizing such milled materials, pre~erably at cryogenic temperatures, (3) placing the particles resulting from step (2) above into a mold and press curing into the desired shape, preferably under vacuum to minimize or eliminate the possibility of air being entrapped in the flnished article, followed by (4) standard post-curing of the press-cured article.
The initial step of blending the reinforcing agent with the perfluoroelastomer and any other desired compounding ingredients, e.g. conventional fillers, extenders, curing agents and accelerators, is conveniently carried out in a relatively high shear mixing device, such as a rubber mill or a Banbury mixer at a temperature of about $0-80C for 15 - 60 minutes. Such blending conditions will cause the reinforcing agent to be fibrillated while it is being blended with the elastomer. Alternatively, reinforcing agent can be fibrillated prior to blending with the fluoroelastomer.
The reinforcing agent will be fibriles of fibrillated polytetrafluoroethylene on lengths of less than about 1 millimeter. One example of ibrilatable polytetrafluoroethylene resin that is commercially available is E. I. du Pont de ~emours and Company's Teflon* T8A. Generally 1 to 40 parts of reinforcing agent will be blended with 100 parts of the perfluoroelastomer. 2 to ~0 parts is preferred. Too little reinforcing agent will result in insufficient increase in tear strength of the finished product. Too much will result in lower tensile and elongation properties. It is important that the reinforcing agent be blended with the perfluoroelastomer prior to cryogenic comminution of the milled material. Blending of the reinforcing * denotes trade mark agent ~.~ith the perfl~loroelastomer ~uring pulverization, or mixing the reinforciny agent wi~h the particles resulting from the cryogenic pulverization, fo~lowed by press and post-curing o~
the powdered fluoroelastomer/re.inforcing agent mixture doe~ not provide significant increase in tear strength.
The pulverization of the perfluoroelastomer milled material can be conducted, for example, by cutting the milled material into pieces not greater than 1/4 inch (6.35 mm) at room temperature in an Abbe*cu~ter, followed by pulverization of the 1/4 inch (6.35 mm) particles in a Bantam Micro Pulverizer*
operating at a rotor speed of 14jOOO r.p.m. at liquid nitrogen temperature. Following pulverization, the product should be dried, for example in an oven at 60 - 120C, preferably in a nitrogen atmosphere, although dry air or vacuum is also suitable. Molding of a perfluoroelastomer containing moistuxe may result in blowing, sponging or other undesirable mold characteristics. Per~luoroelastomer particles resulting from the cryogenic pulverization should pass through a screen having an opening of 1.~5 mm (10 mesh) or less, preferably 16 mesh (0.991 mm opening). Typical samples pulverized as above have been found to have a particle size distribution as follows:
paxticles greater than 14 mesh (1.17 mm) - none particles greater than 24 mesh ~0.701 mm~ - O - 4%
particles greater than 32 mesh (0.495 mm) - 28 - 42%
particles greater than 65 mesh (0.208 mm) - 38 58%
particles greater than 100 mesh (0.147 mm) - 6 - 9%
particles greater than 150 mesh (0.104 mm) - O - 6%
with residual fines of 1 - 5%
* denotes trade marX
Z~
Press curing and post-curing are conducted as would be normal for a perEluoroelastomer that has not been cryogenically pulverized. For examp1e, see ~alb et al, Advances in Chemistry Series No. 129, pp 13-26 (1973).
The rollowing examples illustrate on a comparative basis the tear strength properties that will be achieved in unmodified perfluoroelastomer, perfluoroelasto~er reinforced by conventional means with polytetrafluoroethylene, and perfluoroelastomer reinforced with polytetrafluoroethylene by the process of the present invention. In each of the following examples, standard elastomer processing and testing procedures were used. Compounds were milled on a standard two-roll rubber ~ill at 60C. Slabs were sheeted off the mill at the desired thickness.
Slabs (152mm X 152mm X 2mm) were used to prepare die-cut test samples having dimensions as specified in ASTM D-624-B, the test samples beins taXen from positions within each slab as shown in the Figure.
Tear strength was measured on an Instron Corp.
tensile tester and as described more fully in ASTM
D-624B. Polymer composition, compounding ingredients, press-curing and post-curing conditions were as described in the following examples. All parts and percentages are by weight and temperatures are in degrees Celsius unless specified otherwise.
Measurements made in other than S.I. units have been converted to S.I. units and rounded as appropriate.
No Reinforcement A terpolymer of tetrafluoroethylene, perfluoromethylvinyl ether (PMVE), and perfluoro(2-phenoxypropyl vinyl ether) (P2PVE) was 35 prepared by and isolated by the procedure described ~2~
in U.S. Patent ,467,638. This terpolymer contained
Kalb et al also discloses the outstandiny solvent and chemical resistance that can be obtained with these elasto~ers.
U.S. Patent 3,546,186 granted De-ember 8, 1970 to Gladding and Sullivan, discloses certain vulcanizable copolymers of substituted perfluorovinyl ether. In particular,~ among the many and varied copolymers disclosed by Gladding and Sullivan, there are disclosed terpolymers derived from tetrafluoroethylene, perfluoromethyl perfluorovinyl ether and a cure-site monomer which can be, a~ong other things, perfluoro(4-cyanobutyl vinyl ether) or perfluoro~4-carbomethoxybutyl vinyl ethe~).
U.S. Patent 3,46~,638, granted September 16, 1969 to Pattison, discloses certain vulcanizable copolymer~ of substituted perfluorovinyl ether. In particular, among the many and varied copolymers disclosed by Pattison, there are disclosed terpolymers derived from tetrafluoroethylene, perfluoromethyl perfluorovinyl ether and a cure-site monomer which can be, among other things, perfluoro(2-phenoxypropyl vinyl ether).
U.S. Patent 3,682,872, granted August 8, 1972 to Brizzolara and Quarles, discloses certain vulcani~able copolymers of substituted perfluorovinyl ether. In particular, among the many and varied copolymers disclosed by srizzolara and Quarles there are disclosed terpolymers derived from tetrafluoroethylene, perfluoromethyl perfluorovin~l ether and, as a cure-site monomer, perfluoro(3-phenoxypropyl vinyl ether).
U.S. Patent 4,281,092, granted July 28, 1981 to Breazeale, discloses certain vulcanizable copolymers of tetrafluoroethylene, perfluoro~ethyl perfluorovinyl ether and a cure-site monomer ~hich can be perfluoro(8-cyano-5-methyl-3,~-dioxa-1-octene).
U.S. Patent 4,035,565, granted ~uly l2, 1977 to Apotheker et al. discloses, among other thincls, certain vulcanizable copolymers o~ up to 3 mole percent of a bromine containing olefin, tetrafluoroethylene, and a perfluoroalkyl perfluorovinyl ether.
Perfluoroelastomer compositions based on the polymers disclosed in the back~round art summarized above can be improved by the incorporation of fibrous materials therein by the process of the present lnventlon .
Disclosure of the Invention The present invention relates to a method for reinEorcing certain vulcanizable perfluoroelastomer compositions, wherein the perfluoroelastomer is preferably a terpolymer derived from tetrafluoroethylene, perfluoromethyl perfluorovinyl ether and a cure-site monomer, thus permitting the manufacture of finished perfluoroelastomer parts with high multidirectiona]
tear strength as compared with unreinforced perfluoroelastomer parts or perfluoroelastomer parts reinforced by conventional techni~ues.
The terpolymers used in the parts made by the process of the present invention are substantially as described by Kalb et al, Gadding and Sullivan, Pattison, Brizzolara and Quarles, Breazeale, and Apotheker et al. in the references cited above and generally comprise copolymerized units of about 53-79.8 mole percent of tetrafluoroethylene (TFE), about 20-45 mole percent of perfluoromethyl perfluorovinyl ether (PMVE), and 0.2-2 mole percent of a cure site monomer selected from the group consisting of:
2 '1 ~
, ~ ~
(a) perfluoro(4-cyanobutyl vinyl ether), (b) perfluoro(4-carbomethoxybutyl vinyl ether), (c) perfluoro(2-phenoxypropyl vinyl ether), (d) perfluoro(3-phenoxypropyl vinyl ether), (e) perfluoro(8-cyano-5-methyl-3, 6-dioxa-1-octene), and (f) a bromo-containing olefin.
Such terpolymers can be prepared by the procedures taught in the references cited above. Preferably the compositions of the present invention are based upon terpolymers in which the cure-site monomer is perfluoro(2-phenoxypropyl vinyl ether), or perfluoro(8-cyano-5-methyl-3,6-dioxa-1-octene) and most preferably, they are based on such terpolymers in which the proportions of the monomers are about 65.4-73.6 mole percent TFE, 26-34 mole percent PMVE, and the remainder is perfluoro(2-phenoxypropyl vinyl ether) or perfluoro (8-cyano-5-methyl-3,6-dioxa-1-octene~. It should be understood that exact determination of the monomer proportions is difficult and that the values given are estimates based on infrared spectra.
As with conventional vulcanizable fluoroelastomer compositions, it is frequently desirable to mix fillers such as carbon black or one or more non-black fillers, such as titanium dioxide, -~
~z~
zirconium ~ioxide, 5ilica, clay and asbes~os, reinforcing ayents, stabilizers, plasticizers, lubricants or processing aids with the elastomer prior to vulcanization.
Typical reinforcing agents include polytetrafluoroethylene (PTFE) and copolymers of hexafluoropropylene and tetrafluoroethylene.
Fibriles of fibrillated PTFE are especially preferred where increased tear strength is required without any significant sacrifice in resistance to environmental attack or in resistance to heat and corrosive fluids. Such reinforcing agents are typically incorporated into the uncured perfluoroelastomer by blending the reinforcing agent and any other desired compounding ingredients with the perfluoroelastomer on a rubber mill at controlled temperature.
It has been found, however, that whe~
fibrillatable PTFE reinforcing agent is processed in the manner described above, a product results in which the tear strength perpendicular to the direction of milling ~the perpendicular direction) is significantly increased while tear strength parallel to the direction of milling (the initial direction) is not significantly increased. It is believed that this is due to oriantation of the reinforcing agent substantially parallel to the direction of milling.
In some end use applications, such as in diaphragms, improved multidirectional tear strength (i.e., tear strength in both the initial and the perpendicular directions) is important.
It has been found that such improved multidirectional tear strength can be achieved by the process of the present invention. In particular, it has been found that such results can be achieved by (1) preparing milled materials substantially as ~8~
descri~ed abo~e, (2) pulverizing such milled materials, pre~erably at cryogenic temperatures, (3) placing the particles resulting from step (2) above into a mold and press curing into the desired shape, preferably under vacuum to minimize or eliminate the possibility of air being entrapped in the flnished article, followed by (4) standard post-curing of the press-cured article.
The initial step of blending the reinforcing agent with the perfluoroelastomer and any other desired compounding ingredients, e.g. conventional fillers, extenders, curing agents and accelerators, is conveniently carried out in a relatively high shear mixing device, such as a rubber mill or a Banbury mixer at a temperature of about $0-80C for 15 - 60 minutes. Such blending conditions will cause the reinforcing agent to be fibrillated while it is being blended with the elastomer. Alternatively, reinforcing agent can be fibrillated prior to blending with the fluoroelastomer.
The reinforcing agent will be fibriles of fibrillated polytetrafluoroethylene on lengths of less than about 1 millimeter. One example of ibrilatable polytetrafluoroethylene resin that is commercially available is E. I. du Pont de ~emours and Company's Teflon* T8A. Generally 1 to 40 parts of reinforcing agent will be blended with 100 parts of the perfluoroelastomer. 2 to ~0 parts is preferred. Too little reinforcing agent will result in insufficient increase in tear strength of the finished product. Too much will result in lower tensile and elongation properties. It is important that the reinforcing agent be blended with the perfluoroelastomer prior to cryogenic comminution of the milled material. Blending of the reinforcing * denotes trade mark agent ~.~ith the perfl~loroelastomer ~uring pulverization, or mixing the reinforciny agent wi~h the particles resulting from the cryogenic pulverization, fo~lowed by press and post-curing o~
the powdered fluoroelastomer/re.inforcing agent mixture doe~ not provide significant increase in tear strength.
The pulverization of the perfluoroelastomer milled material can be conducted, for example, by cutting the milled material into pieces not greater than 1/4 inch (6.35 mm) at room temperature in an Abbe*cu~ter, followed by pulverization of the 1/4 inch (6.35 mm) particles in a Bantam Micro Pulverizer*
operating at a rotor speed of 14jOOO r.p.m. at liquid nitrogen temperature. Following pulverization, the product should be dried, for example in an oven at 60 - 120C, preferably in a nitrogen atmosphere, although dry air or vacuum is also suitable. Molding of a perfluoroelastomer containing moistuxe may result in blowing, sponging or other undesirable mold characteristics. Per~luoroelastomer particles resulting from the cryogenic pulverization should pass through a screen having an opening of 1.~5 mm (10 mesh) or less, preferably 16 mesh (0.991 mm opening). Typical samples pulverized as above have been found to have a particle size distribution as follows:
paxticles greater than 14 mesh (1.17 mm) - none particles greater than 24 mesh ~0.701 mm~ - O - 4%
particles greater than 32 mesh (0.495 mm) - 28 - 42%
particles greater than 65 mesh (0.208 mm) - 38 58%
particles greater than 100 mesh (0.147 mm) - 6 - 9%
particles greater than 150 mesh (0.104 mm) - O - 6%
with residual fines of 1 - 5%
* denotes trade marX
Z~
Press curing and post-curing are conducted as would be normal for a perEluoroelastomer that has not been cryogenically pulverized. For examp1e, see ~alb et al, Advances in Chemistry Series No. 129, pp 13-26 (1973).
The rollowing examples illustrate on a comparative basis the tear strength properties that will be achieved in unmodified perfluoroelastomer, perfluoroelasto~er reinforced by conventional means with polytetrafluoroethylene, and perfluoroelastomer reinforced with polytetrafluoroethylene by the process of the present invention. In each of the following examples, standard elastomer processing and testing procedures were used. Compounds were milled on a standard two-roll rubber ~ill at 60C. Slabs were sheeted off the mill at the desired thickness.
Slabs (152mm X 152mm X 2mm) were used to prepare die-cut test samples having dimensions as specified in ASTM D-624-B, the test samples beins taXen from positions within each slab as shown in the Figure.
Tear strength was measured on an Instron Corp.
tensile tester and as described more fully in ASTM
D-624B. Polymer composition, compounding ingredients, press-curing and post-curing conditions were as described in the following examples. All parts and percentages are by weight and temperatures are in degrees Celsius unless specified otherwise.
Measurements made in other than S.I. units have been converted to S.I. units and rounded as appropriate.
No Reinforcement A terpolymer of tetrafluoroethylene, perfluoromethylvinyl ether (PMVE), and perfluoro(2-phenoxypropyl vinyl ether) (P2PVE) was 35 prepared by and isolated by the procedure described ~2~
in U.S. Patent ,467,638. This terpolymer contained
3~% P~V~ and 0.5~ P2PVE. 1100 grams of thi~
terpolymer were then compounded with 33 grams of 18 crown-6 tl,4,7,10,13,16-hexaoxacyclGoctadecane), 49.5 grams of potassium salt of bisphenol A~
(4,4'-hexafl~oroisopropylidenediphenol), and 236.5 grams of Titanox* 2071 (titanium dioxide) on a standard ruhber roll mill at 60C. Hereafter this will be called compound I.
This milled slab was annealed at 100C for 15 minutes. A die c~t sample was then placed in a slab mold at room temperature. The mold was placed in a resistance heated press at room te~perature under 76,000 kPa pressure. Temperature was increased to 177C in 20 minutes and then held constant for 100 minutes. The resulting part was postcured under N2 using the following temperature proqram:
Time Temperature 0 to 6 hrs. 23 ~204C
~6 to 24 hrs. 204C
24 to 30 hrs. 204~ 288C
30 to 48 hrs. 288C
Test s~mples were then labeled and removed from the postcured sheet as shown in the Figure.
The tear ~est results at room temperature were: -Direction SampleTear Strength kN/~
Mill ~ 22.06 Mill 3 25.39 30 Cr~ss Mill 6 2$.04 Cross Mill 7 25.21 Cross Mill 8 25.56 Cross Mill 11 25.49 * denotes trade mark .
EXAMPL~ 2 Reinforcement By Milling Perfluoroelastomer 3.~ pph (parts per hundred) of "Teflon" T8A
was milled into Compound I found in Example 1 at 60C. Hereafter, this is called Compound II. This reinforced milled slab was annealed at 100C for 15 minutes.
A die cut sample was then placed in a mold at room temperature. The mold was placed in a resistance heated press at room temperature under 76,000 kP2 pressure. Temperature was increased to 177C in 20 minutes and then held constant for 100 minutes. The resulting part was postcured under ~2 using the followiny temperature program:
Time Temperature 0 to 6 hrs. 23 ~204C
6 to ~4 hrs. 204C
24 to 30 hrs. 204-~ 288C
30 to 48 hrs. 288C
Test samples were then labeled and removed from the postcured sheet as shown in the Figure.
The tear test results at room temperature were:
Direction Sample Tear Strength kN/m 25 Mill ~ 3~ 07 Mill 3 38.00 Cross Mill 6 23.81 Cross Mill 7 24.34 Cross Mill 8 24.86 In Examples 3-5 below there is no mill direction and cross-mill direction, because the milled material was pulverized. Accordingly, Samples 1-4 in each of these Examples will be considered to be taken from the initial direction and Samples 5-10 were taken from a direction perpendicular to the initial direction, as shown in the Figure.
EX~PLE 3 Reinforcement By Pulverizinq Milled Perfluoroelastomer Compound II from Example 2 was t.hen pulverized in a hammer mill at -210C. Particles which passed through a 16 mesh (0.991 mm. opening) screen were dried at 120C for 15 minutes. These particles were then placed in a mold. The mold was placed in a room temperature resistance heated press at room temperature under 76,000 kPa pressure.
Temperature was increased to 177C in 20 minutes and then held constant for lO0 minutes. The resulting part was postcured under N2 using the following temperature program:
Time Temperature 0 to 6 hrs. 23~ 204C
6 to 24 hrs. 204C
24 to 30 hrs. 204~ 288C
30 to 48 hrs. 288C
Test samples were then labeled and removed from the postcured sheet as shown in the Figure.
The tear test results at room temperature were:
Direction Sam~le Tear Strength k~/m 25 Initial 3 41~67 Initial 4 40 45 Perpendicular 6 40.27 Perpendicular 8 39.22 Perpendicular lO 42.90 Reinforcement By Pulverizing Perfluoroelastomer Without Prior Millinq The annealed slab of Example l was pulverized in a hammer mill at -210C. Particles which passed through a 16 mesh (0.99l mm opening) screen were dried and collected. Pure "Teflon" T8A
was fibrillated on the 60C rubber roll mills, then annealed and pulverized in the manner described in Example 3 above. Particles of fibrillated "Teflon"
which passed through a 16 mesh (0.991 mm opening) screen were dried and collected.
The perfluoroelastomer particles were then mixed with 10.0 pph of "Teflon" T8A powder for 6 minutes on a paint shaker.
This particulate mixture of perfluoroelastomer and fibrillated "Teflon" was then placed in a mold at room temperature. The mold was - placed in a resistance heated press at room temperature under 76,000 kPa pressure. Temperature was increased to 177C in 20 minutes and then held constant for 100 minutes. The resulting part was postcured under N2 using the following temperature program:
Time Temperature 0 to 6 hrs. 23~ 204C
6 to 24 hrs. 204C
24 to 30 hrs. 204 ~288C
30 to 48 hrs. 288C
Test samples were then labeled and removed from the / 25 postcured sheet as shown in the Figure.
The tear test results at room temperature were:
Direction Sample Tear Strength ~!m Mill 2 29.24 30 Mill 3 30.99 Cross Mill 5 24.51 Cross Mill 7 24.51 Cross Mill 9 26.44 Cross Mill 11 31.52 Reinforcement By Pulverizing Milled Perfluoroelastomer at Increased Loadings 40 ppH of "Teflon" T8A was milled into Compound I of Example 1 at 60C. This compound was annealed at 100C for 15 minutes and then pulverized in a hammer mill at -210C. Particles which passed through a 16 mesh (0.991 mm opening) screen were dried. These particles were then placed in a mold at room temperature. The mold was placed in a resistance heated press at room temperature under 76,000 kPa pressure. Temperature was increased to 177C in 20 minutes and then held constant for 100 minutes. The resulting part was postcured under N2 using the following temperature program.
Time Temperature 0 to 6 hrs. 23 ~204C
6 to 24 hrs. 204C
24 to 30 hrs. 204 -~288~C
30 to 48 hrs. 288C
Test samples were then labeled and removed from the postcured sheet as shown in the Figure.
The tear ~est results at room temperature were:
25 Direction Sample Tear Strength kN/m Mill 2 82.82 Mill 3 93.33 Cross Mill 5 75 99 Cross Mill 7 94-03 30 Cross Mill 9 83.87 Cross Mill 11 81.60 Industrial Applicability The perfluoroelastomer parts produced by the process of the present invention are useful in the manufacture of finished parts such as 0-rings, flange seals, gasket stock, pump diaphragms and levers. The ext~aordinary physical properties and resistance to environmental attack of such parts made from these compositions maXe them particularly well suited for applications in process streams subject to severe fluid service at inline temperatures as high as 371C
or in streams carrying highly corrosive fluids, such as hydrogen sulfide; especially in end use application where high multidirectional tear strength is required, such as in certain types of diaphragms.
Best Mode Although the best mode of the present invention, i.e., the method for producing the best perfluoroelastomer parts, will depend upon the particular desired end use and tne specific requisite combination of properties for that use, the single most preferred method of the present invention is that described in detail in Example 3.
3;
terpolymer were then compounded with 33 grams of 18 crown-6 tl,4,7,10,13,16-hexaoxacyclGoctadecane), 49.5 grams of potassium salt of bisphenol A~
(4,4'-hexafl~oroisopropylidenediphenol), and 236.5 grams of Titanox* 2071 (titanium dioxide) on a standard ruhber roll mill at 60C. Hereafter this will be called compound I.
This milled slab was annealed at 100C for 15 minutes. A die c~t sample was then placed in a slab mold at room temperature. The mold was placed in a resistance heated press at room te~perature under 76,000 kPa pressure. Temperature was increased to 177C in 20 minutes and then held constant for 100 minutes. The resulting part was postcured under N2 using the following temperature proqram:
Time Temperature 0 to 6 hrs. 23 ~204C
~6 to 24 hrs. 204C
24 to 30 hrs. 204~ 288C
30 to 48 hrs. 288C
Test s~mples were then labeled and removed from the postcured sheet as shown in the Figure.
The tear ~est results at room temperature were: -Direction SampleTear Strength kN/~
Mill ~ 22.06 Mill 3 25.39 30 Cr~ss Mill 6 2$.04 Cross Mill 7 25.21 Cross Mill 8 25.56 Cross Mill 11 25.49 * denotes trade mark .
EXAMPL~ 2 Reinforcement By Milling Perfluoroelastomer 3.~ pph (parts per hundred) of "Teflon" T8A
was milled into Compound I found in Example 1 at 60C. Hereafter, this is called Compound II. This reinforced milled slab was annealed at 100C for 15 minutes.
A die cut sample was then placed in a mold at room temperature. The mold was placed in a resistance heated press at room temperature under 76,000 kP2 pressure. Temperature was increased to 177C in 20 minutes and then held constant for 100 minutes. The resulting part was postcured under ~2 using the followiny temperature program:
Time Temperature 0 to 6 hrs. 23 ~204C
6 to ~4 hrs. 204C
24 to 30 hrs. 204-~ 288C
30 to 48 hrs. 288C
Test samples were then labeled and removed from the postcured sheet as shown in the Figure.
The tear test results at room temperature were:
Direction Sample Tear Strength kN/m 25 Mill ~ 3~ 07 Mill 3 38.00 Cross Mill 6 23.81 Cross Mill 7 24.34 Cross Mill 8 24.86 In Examples 3-5 below there is no mill direction and cross-mill direction, because the milled material was pulverized. Accordingly, Samples 1-4 in each of these Examples will be considered to be taken from the initial direction and Samples 5-10 were taken from a direction perpendicular to the initial direction, as shown in the Figure.
EX~PLE 3 Reinforcement By Pulverizinq Milled Perfluoroelastomer Compound II from Example 2 was t.hen pulverized in a hammer mill at -210C. Particles which passed through a 16 mesh (0.991 mm. opening) screen were dried at 120C for 15 minutes. These particles were then placed in a mold. The mold was placed in a room temperature resistance heated press at room temperature under 76,000 kPa pressure.
Temperature was increased to 177C in 20 minutes and then held constant for lO0 minutes. The resulting part was postcured under N2 using the following temperature program:
Time Temperature 0 to 6 hrs. 23~ 204C
6 to 24 hrs. 204C
24 to 30 hrs. 204~ 288C
30 to 48 hrs. 288C
Test samples were then labeled and removed from the postcured sheet as shown in the Figure.
The tear test results at room temperature were:
Direction Sam~le Tear Strength k~/m 25 Initial 3 41~67 Initial 4 40 45 Perpendicular 6 40.27 Perpendicular 8 39.22 Perpendicular lO 42.90 Reinforcement By Pulverizing Perfluoroelastomer Without Prior Millinq The annealed slab of Example l was pulverized in a hammer mill at -210C. Particles which passed through a 16 mesh (0.99l mm opening) screen were dried and collected. Pure "Teflon" T8A
was fibrillated on the 60C rubber roll mills, then annealed and pulverized in the manner described in Example 3 above. Particles of fibrillated "Teflon"
which passed through a 16 mesh (0.991 mm opening) screen were dried and collected.
The perfluoroelastomer particles were then mixed with 10.0 pph of "Teflon" T8A powder for 6 minutes on a paint shaker.
This particulate mixture of perfluoroelastomer and fibrillated "Teflon" was then placed in a mold at room temperature. The mold was - placed in a resistance heated press at room temperature under 76,000 kPa pressure. Temperature was increased to 177C in 20 minutes and then held constant for 100 minutes. The resulting part was postcured under N2 using the following temperature program:
Time Temperature 0 to 6 hrs. 23~ 204C
6 to 24 hrs. 204C
24 to 30 hrs. 204 ~288C
30 to 48 hrs. 288C
Test samples were then labeled and removed from the / 25 postcured sheet as shown in the Figure.
The tear test results at room temperature were:
Direction Sample Tear Strength ~!m Mill 2 29.24 30 Mill 3 30.99 Cross Mill 5 24.51 Cross Mill 7 24.51 Cross Mill 9 26.44 Cross Mill 11 31.52 Reinforcement By Pulverizing Milled Perfluoroelastomer at Increased Loadings 40 ppH of "Teflon" T8A was milled into Compound I of Example 1 at 60C. This compound was annealed at 100C for 15 minutes and then pulverized in a hammer mill at -210C. Particles which passed through a 16 mesh (0.991 mm opening) screen were dried. These particles were then placed in a mold at room temperature. The mold was placed in a resistance heated press at room temperature under 76,000 kPa pressure. Temperature was increased to 177C in 20 minutes and then held constant for 100 minutes. The resulting part was postcured under N2 using the following temperature program.
Time Temperature 0 to 6 hrs. 23 ~204C
6 to 24 hrs. 204C
24 to 30 hrs. 204 -~288~C
30 to 48 hrs. 288C
Test samples were then labeled and removed from the postcured sheet as shown in the Figure.
The tear ~est results at room temperature were:
25 Direction Sample Tear Strength kN/m Mill 2 82.82 Mill 3 93.33 Cross Mill 5 75 99 Cross Mill 7 94-03 30 Cross Mill 9 83.87 Cross Mill 11 81.60 Industrial Applicability The perfluoroelastomer parts produced by the process of the present invention are useful in the manufacture of finished parts such as 0-rings, flange seals, gasket stock, pump diaphragms and levers. The ext~aordinary physical properties and resistance to environmental attack of such parts made from these compositions maXe them particularly well suited for applications in process streams subject to severe fluid service at inline temperatures as high as 371C
or in streams carrying highly corrosive fluids, such as hydrogen sulfide; especially in end use application where high multidirectional tear strength is required, such as in certain types of diaphragms.
Best Mode Although the best mode of the present invention, i.e., the method for producing the best perfluoroelastomer parts, will depend upon the particular desired end use and tne specific requisite combination of properties for that use, the single most preferred method of the present invention is that described in detail in Example 3.
3;
Claims (10)
1. A method for the preparation of perfluoroelastomer parts having high multidirectional tear strength comprising:
(a) preparing a blend of the perfluoroelastomer with 1 to 40 parts of fibrillated polytetrafluoroethylene, (b) cryogenically pulverizing the blend produced from step (a) into a powder, (c) placing the powder produced from step (b) into a mold and press-curing the powder into the desired shape for the perfluoroelastomer part.
(a) preparing a blend of the perfluoroelastomer with 1 to 40 parts of fibrillated polytetrafluoroethylene, (b) cryogenically pulverizing the blend produced from step (a) into a powder, (c) placing the powder produced from step (b) into a mold and press-curing the powder into the desired shape for the perfluoroelastomer part.
2. The method of claim 1 wherein the perfluoroelastomer is a terpolymer of tetrafluoroethylene, perfluoro(methyl vinyl ether) and a third monomer selected from the group consisting of:
(a) perfluoro(4-cyanobutyl vinyl ether), (b) perfluoro(4-carbomethoxybutyl vinyl ether), (c) perfluoro(2-phenoxypropyl vinyl ether), (d) perfluoro(3-phenoxypropyl vinyl ether), (e) perfluoro(8-cyano-5-methyl-3,6-dioxa-1-octene), and (f) a bromo-containing olefin.
(a) perfluoro(4-cyanobutyl vinyl ether), (b) perfluoro(4-carbomethoxybutyl vinyl ether), (c) perfluoro(2-phenoxypropyl vinyl ether), (d) perfluoro(3-phenoxypropyl vinyl ether), (e) perfluoro(8-cyano-5-methyl-3,6-dioxa-1-octene), and (f) a bromo-containing olefin.
3. The method of claim 1 wherein the powder produced in pulverization step (b) has substantially all of its particles less than 10 mesh in size.
4. The method of claim 2 wherein the third monomer is perfluoro(2-phenoxypropyl vinyl ether).
5. The method of claim 2 wherein the third monomer is perfluoro(8-cyano-5-methyl-3,6-dioxa-1-octene).
6. The method of claim 2 wherein tetrafluoroethylene units comprise 53-79.8 mole percent of the perfluoroelastomer and the perfluoro(methyl vinyl ether) units comprise 20-45 mole percent of the perfluoroelastomer.
7. The method of claim 1 wherein the perfluoroelastomer part produced from step (c) is post cured.
8. A perfluoroelastomer part produced by the method of claim 1.
9. A perfluoroelastomer part of claim 7 which is in the shape of a diaphragm.
10. A perfluoroelastomer diaphragm of claim 9 which has a tear strength as measured by ASTM test D-624-B in both an initial and perpendicular direction of at least 36 kN/m.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US420,478 | 1982-09-20 | ||
| US06/420,478 US4520170A (en) | 1982-09-20 | 1982-09-20 | Method for reinforcing perfluoroelastomer compositions |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1218210A true CA1218210A (en) | 1987-02-24 |
Family
ID=23666644
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000436743A Expired CA1218210A (en) | 1982-09-20 | 1983-09-15 | Method for reinforcing perfluoroelastomer compositions |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4520170A (en) |
| EP (1) | EP0106180B1 (en) |
| JP (1) | JPS5980457A (en) |
| CA (1) | CA1218210A (en) |
| DE (1) | DE3372485D1 (en) |
Families Citing this family (25)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4713418A (en) * | 1985-12-06 | 1987-12-15 | E. I. Du Pont De Nemours And Company | Blends of fluoroplastics and fluoroelastomers |
| US4904726A (en) * | 1987-12-31 | 1990-02-27 | E. I. Dupont Denemours And Company | Modified polytetrafluoroethylene resins and blends thereof |
| US4952630A (en) * | 1987-12-31 | 1990-08-28 | E. I. Du Pont De Nemours And Company | Modified polytetrafluoroethylene resins and blends thereof |
| EP0373094A3 (en) * | 1988-12-08 | 1991-04-17 | The Goodyear Tire & Rubber Company | Tire tread containing fibrillated fibers |
| US5646192A (en) * | 1993-02-23 | 1997-07-08 | W. L. Gore & Associates, Inc. | Polytetrafluoroethylene molding powder |
| US5658960A (en) * | 1993-02-23 | 1997-08-19 | W.L. Gore & Associates, Inc. | Polytetrafluoroethylene molding resin and processes |
| EP0686079B1 (en) * | 1993-02-23 | 2000-03-15 | W.L. Gore & Associates, Inc. | Polytetrafluoroethylene molding powder and processes |
| JP3208913B2 (en) * | 1993-03-23 | 2001-09-17 | キヤノン株式会社 | Fixing device and fixing roller |
| US5393819A (en) * | 1994-02-25 | 1995-02-28 | Alphaflex Industries | Asphalt modifier |
| US5399598A (en) * | 1994-03-03 | 1995-03-21 | Alphaflex Industries | Asphalt composition |
| US5418270A (en) * | 1994-04-12 | 1995-05-23 | Alphaflex Industries, Inc. | Modified thermoplastic elastomeric compositions |
| US5645603A (en) * | 1995-07-25 | 1997-07-08 | Peters; William E. | Method of enhancing physical properties of non-elastomeric thermoplastic materials and resulting compositions |
| JP3941128B2 (en) * | 1995-12-18 | 2007-07-04 | ダイキン工業株式会社 | Powder coating composition |
| US6239223B1 (en) | 1997-09-05 | 2001-05-29 | Chemfab Corporation | Fluoropolymeric composition |
| EP1112317B1 (en) | 1998-08-21 | 2004-05-12 | Dupont Dow Elastomers L.L.C. | Crosslinkable fluoroelastomer composition |
| US7049380B1 (en) * | 1999-01-19 | 2006-05-23 | Gore Enterprise Holdings, Inc. | Thermoplastic copolymer of tetrafluoroethylene and perfluoromethyl vinyl ether and medical devices employing the copolymer |
| JP4284495B2 (en) * | 2001-02-05 | 2009-06-24 | スリーディーエム テクノロジーズ、インク． | Plastic molding method, plastic molding apparatus, and parts made therefrom |
| US20040024448A1 (en) | 2002-08-05 | 2004-02-05 | Chang James W. | Thermoplastic fluoropolymer-coated medical devices |
| US7683130B2 (en) * | 2005-07-18 | 2010-03-23 | E.I. Du Pont De Nemours And Company | Filled perfluoropolymer composition comprising a low melting fluoropolymer additive |
| US7579409B2 (en) * | 2005-10-27 | 2009-08-25 | Agc Chemicals Americas, Inc. | Polyetrafluoroethylene micropowder compositions |
| EP1947144B1 (en) * | 2005-10-31 | 2012-11-21 | Daikin Industries, Ltd. | Method for molding polytetrafluoroethylene, polytetrafluoroethylene molded body, crosslinkable polytetrafluoroethylene, crosslinked polytetrafluoroethylene powder, resin blend composition, and molded body of resin blend |
| GB2451096A (en) * | 2007-07-17 | 2009-01-21 | Whitford Plastics Ltd | Method of preparing a powdered fluoropolymer blend |
| US20110269909A1 (en) * | 2010-04-29 | 2011-11-03 | E.I. Du Pont De Nemours And Company | Manufacture of perfluoroelastomer compounds containing fibrillating ptfe |
| RU2471827C1 (en) * | 2011-07-19 | 2013-01-10 | Федеральное государственное унитарное предприятие "Ордена Ленина и ордена Трудового Красного Знамени научно-исследовательский институт синтетического каучука имени академика С.В. Лебедева" | Elastomeric composition based on copolymer of tetrafluoroethylene and perfluoroalkyl vinyl esters |
| US8846812B2 (en) | 2011-12-15 | 2014-09-30 | E I Du Pont De Nemours And Company | Process for manufacturing fluoroelastomer compositions containing fluoroplastic fibrils |
Family Cites Families (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1145445A (en) * | 1966-02-16 | 1969-03-12 | Du Pont | Fluorinated perfluorovinylethers, their preparation and copolymers thereof |
| US3467638A (en) * | 1967-03-07 | 1969-09-16 | Du Pont | Fluorinated cure-site monomers and vulcanizable fluorocarbon polymers made therewith |
| US3445393A (en) * | 1967-03-21 | 1969-05-20 | Oil Center Research Inc | Packing and sealing composition |
| US3655611A (en) * | 1968-08-09 | 1972-04-11 | Allied Chem | Cold flow resistant homogeneous polymers of tetrafluoroethylene and hexafluoropropene and process for preparing them |
| US3682872A (en) * | 1970-03-18 | 1972-08-08 | Du Pont | Perfluoro(3-phenoxypropyl vinyl ether) monomer and copolymers made therefrom |
| US3733295A (en) * | 1970-12-28 | 1973-05-15 | Trw Inc | Fluorocarbon filled carboxynitroso polybutadiene vulcanizate |
| US3872045A (en) * | 1973-08-22 | 1975-03-18 | Us Navy | Fluorinated epoxy resins containing polytetrafluoroalkylene fillers |
| US3929934A (en) * | 1973-11-19 | 1975-12-30 | Du Pont | Novel fluoroelastomers in powder form |
| DE2442173A1 (en) * | 1974-09-03 | 1976-03-11 | Dynamit Nobel Ag | POLYVINYLIDEN FLUORIDE SHAPED BODY WITH INCREASED IMPACT STRENGTH AND TENSION |
| US4200568A (en) * | 1974-09-03 | 1980-04-29 | Dynamit Nobel Aktiengesellschaft | Polyvinylidene fluoride compositions, and fabricated products thereof having increased notch impact toughness and elongation at rupture |
| US4035565A (en) * | 1975-03-27 | 1977-07-12 | E. I. Du Pont De Nemours And Company | Fluoropolymer containing a small amount of bromine-containing olefin units |
| JPS51145582A (en) * | 1975-06-09 | 1976-12-14 | Shinetsu Chemical Co | Method of making molded fluorineerubber article |
| JPS538650A (en) * | 1976-07-13 | 1978-01-26 | Asahi Glass Co Ltd | Fluorine-containig elastomer composition having improved tear strength and its preparation |
| JPS5334848A (en) * | 1976-09-10 | 1978-03-31 | Asahi Glass Co Ltd | Fluorine-containing elastomer composition of high tear strength and its production |
| JPS5346342A (en) * | 1976-10-08 | 1978-04-25 | Asahi Glass Co Ltd | Fluorine-containing elastomer composition with high tear strength and its production |
| JPS53139661A (en) * | 1977-05-12 | 1978-12-06 | Mitsui Fluorochemicals Co Ltd | Polytetrafluoroethylene powder pellet containing glass powder and method of making same |
| JPS53139660A (en) * | 1977-05-12 | 1978-12-06 | Mitsui Fluorochemicals Co Ltd | Method of making mixture of glass powder and polytetrafluoroethylene powder |
| JPS53149881A (en) * | 1977-06-03 | 1978-12-27 | Asahi Glass Co Ltd | Strengthened cation exchange resin membrane and production thereof |
| US4281092A (en) * | 1978-11-30 | 1981-07-28 | E. I. Du Pont De Nemours And Company | Vulcanizable fluorinated copolymers |
| JPS56115343A (en) * | 1980-02-15 | 1981-09-10 | Nippon John Kureen Kk | Synthetic resin composition |
| AU537701B2 (en) * | 1980-05-21 | 1984-07-05 | American District Telegragh Co. | Non-home run zoning system |
-
1982
- 1982-09-20 US US06/420,478 patent/US4520170A/en not_active Expired - Lifetime
-
1983
- 1983-09-15 CA CA000436743A patent/CA1218210A/en not_active Expired
- 1983-09-16 JP JP58169514A patent/JPS5980457A/en active Granted
- 1983-09-17 EP EP83109213A patent/EP0106180B1/en not_active Expired
- 1983-09-17 DE DE8383109213T patent/DE3372485D1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| EP0106180B1 (en) | 1987-07-15 |
| EP0106180A3 (en) | 1984-09-12 |
| JPS5980457A (en) | 1984-05-09 |
| US4520170A (en) | 1985-05-28 |
| DE3372485D1 (en) | 1987-08-20 |
| EP0106180A2 (en) | 1984-04-25 |
| JPH0342303B2 (en) | 1991-06-26 |
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