CA1277067C

CA1277067C - Fluoropolymer coating and casting compositions and films derived therefrom

Info

Publication number: CA1277067C
Application number: CA000479016A
Authority: CA
Inventors: John A. Effenberger; Frank M. Keese
Original assignee: Chemical Fabrics Corp
Current assignee: Saint Gobain Performance Plastics Corp
Priority date: 1984-04-13
Filing date: 1985-04-12
Publication date: 1990-11-27
Anticipated expiration: 2007-11-27
Also published as: DE159268T1; DE3568789D1; JPS6134044A; US4555543A; EP0159268B2; JPH08878B2; EP0159268A3; EP0159268A2; ATE41437T1; EP0419686A1; EP0159268B1

Abstract

ABSTRACT OF THE INVENTION
A fluoroplastic resin dispersion is modified by the addition of a fluoroelastomer latex to yield a fluid coating or casting composition. The fluoroplastic resin dispersion, preferably an aqueous dispersion of a perfluoroplastic, such as polytetrafluoroethylene (PTFE), is modified by blending with a fluoroelastomer composition, preferably a latex, such that the fluoroplastic comprises up to about 95%, preferably up to about 90%, by weight of the invention composition. The fluoroelastomer component comprises at least about 5% by weight of the blend. The fluid compositions according to the invention may preferably comprise from about 10 95%
by weight fluoroplastic and from about 5-90%
fluoroelastomer.

Description

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l`his invention relates to fluoropolymer coating and casting compositions aod films WhiC}l may be derived from such compositions.
It is well known that perfluoroplastic ~oatinys resulting from the simple depositon of arl aqueous disper-sion on a surface will tend to develop cracks while undergoing consolidation during drying or Eusing operations if their thickness exceeds a certain maximum value, commonly referred to as the "critical cracking thickness".
In the case of polytetrafluoroethylene, this thickness is generally expected to be on the order oE 0.001 inches, for coatings applied to smooth horizontal surfaces under idea conditions. For fluorinated ethylenepropylene (EEP) or perfluoroalkoxy ,.. . 1 ,. ,~ . . ..

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modified polytetrafluoroethylene (PFA) the value is less than 0.0005 inches. When such dispersions are applied to vertical surfaces, as is often desirable or necessary in th~
continuous coating of substrates in web form and in the dip or spray coating of objects, the effective critical cracking thickness is substantially reduced, often to less than half of the ideal values. In the case of relatively uneven or textured planar substrates, e.g. woven glass, it is difficult in practice to apply coatings of uniform thickness, since the coating fluids, under the influence of gravitional or capillary forces, tend to flow as théy seek a position of minimum potential energy. This leads inevitably to a vari-ation in the depth of such fluids and a resultant variation in the thickness of coalesced solids derived therefrom.
Cracks can then develop when the thickness of deposited solids exceeds the critical value. In the case of three dimensional objects, surface tension and rapidly rising vis-cosity associated with coalescence often results in beading of the coating fluids along edges or corners of the object, resulting in thick resin deposits susceptible to cracking.
For certain purposes r such as in the coating of textiles~ it is often necessary or desirable to apply uni-form and continuous films of polytetrafluoroethylene or-other fluoroplastics in thicknesses greater than the critical crack ing thickness. A number of technlques for accomplishing this objective are well-known in the art.
Relatively thick crack-free coatings can be achieved through multiple, consecutive applications Oe coatin~ fluid, each of which results in soli~ deposition less than the critical cracking thickness. Each application preferably involves dr~ing and fusing of the solids between subsequent applications of the coating fluid. In the known production of coated textiles as by dip coating, this multiple coat build-up has shortcomi.nys. The technique requires that the textile substrate to which the coating is applied by repeatedly subjected to the high temperatures required to melt fluoroplastics, :i.e.
above 650~F in the case of polytetrafluoroethylene. Such repeated heating to such high temperature can resul-t in degradation of the physical properties of the reinforcement and create mechanical stress concentrations in the coating matrix.
In t~e case of PTFE applied from relatively viscous fluid formulations, the problems associated with critical cracking thickness are dealt with by accepting the presence of cracks in an unfused or semi-fused condition, and subsequently attempting to heal them by calendaring at a temperature sufficient to soften the resin, but insufficient to melt it. The inability to uniformly deliver pressure to the resin thus consolidated due to the presence of hard and relatively stiff textile reinforcements reduces the effectiveness of this approach and some degree of microcracking remains even in the finished, fused products. This method is, moreover, limited to the coating of flexible, planar substrates and is not applicable to the coating of irregular surfaces or objects.
While mineral fillers may be employed to increase the nominal critical cracking thickness, their presence is ~6~25 ~X~77~67 often undesirable for reasons related to the end-use of products so manufactured.
U.S. Patent No. 2,681,324 to Hochberg describes the addition of large quantities of aqueous dispersions of polymeric materials, such as alkyl acrylates and blends thereof, butyl methacrylate, styrene, styrene/butadiene co-polymers, acrylonitrile, or butadiene/acrylonitrile~ copoly-mers, to polytetrafluoroethylene dispersions to form codispersions which can be used to apply relatively thick, crackfree poly tetrafluoroethylene coatings. These materials are thermally unstable at temperatures well below those required to fuse polytetrafluoroethylene and are for the most part fugitive in normal processes with attendant shrink-age of the coalescing film. U.S. Patent `L~O. 2,710,266, to Hochberg describes the addition of aqueous solutions of alkali metal silicates, for example sodium silicate, to polytetra-fluoroethylene dispersions for the same purpose. While suit-able for certain substrates, such compositions are largely unsuitable for the more commonly employed textile substrates, such as glass cloth.
Accordingly, it is an object of this invention to~
provide à fluid fluoropolymer coating composition which can be used to produce, with fewer applications of the fluid, relatively thick, crack-free coatings.
It is also an object of this invention to produce films, supported or unsupported, which are considerably thicker than those which can be readily produced from known formulations, and which may be formed as a planar sheet or a ~6')~
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th ee-dime~sional ~roduct, such as a glove, b]adder, or other shape b~ dipPing or spraying a removal mandrel.
It is a further object of tne inven~ion to proeJide fluoropolymer coating compositions ~hich are process compat-ible with known f~uoroplastics in that films ~crmed therefromcan be thermally welded to them as well as to each other and to fluoroplastics, including perfluoroDlastics.
It is also an object of this invention to provide fluid fluoropolymer coating compositions which may be useful which may be useful for the improvement of fluoropolymer-containin~ articles by ameliorating undesirable behavior stemming from mudcracking and limited build rate inherent to known compositions and methods.
It is another object of this invention to provide fluoropoly~er coatings, composites or film properties the mechanical behavior of which can be controlled through selec-tive formulation of fluoroplastics and fluoroelastomers.
It is yet another object of this invention to pro-vide fluoropolymer coatings or films with physical, chemical and electrical characteristics different from those obtain-able with knowm fluoropolymers.
It is finally an object of this invention to pro-vide a fluoropolymer coating composition able to bridge the rèlatively substantial discontinuities associated with many textile substrates.

1;~7'~06~7 Accordingly, one aspect of the invention provides a fluid composition which comprises a blend of a perfluoroelastomer and a perfluoroplastic, wherein the perfluoroplastic component comprises up to about 95% by weight of the composition.
! Another aspect of the invention provides an unsupported film comprising a resinous component derived from a composition comprising a blend of perfluoroplastic and a perfluoroelastomer, wherein the perfluoroplastic component comprises up to about 95% by weight of the composition, and wherein said blend has been heated to a temperature sufficient to fuse the blend.
Thus, a perfluoroplastic resin dispersion is modified by the addition of a perfluoroelastomer latex to yield a fluid coating or casting composition. The fluoroplastic resin dispersion/ preferably an a~ueous dispersion of a perfluoroplastic, such as polytetrafluoroethylene (PTFE), i5 modified by blending with a perfluoroelastomer composition, preferably a latex, such that the perfluoroplastic comprises up to about 95%, preferably up to about 90%, by weight of the invention composition. The per1uoroelastomer component comprises at least about 5% by weight of the blend. The fluid compositions according to the invention may preferably comprise from about 10-95% by weight of perfluoroplastic and from about 5-90% of perfluoroelastomer.
It should be understood that variations in the properties of the perfluoroplastic and perfluoroelastomer components may be made to accomplish a desired objective.
For example, where a problem associated with the critical cracking thickness of a fluoroplastic resinous composition otherwise suitable, is to be overcome, the blend should comprise at least about 10~ of perfluoroelastomer.
The term "perfluoroplastic" as used herein to define the resin compositions to be modified encompasses both hydrogen-containing perfluoroplastics and hydrogen-free ''~'~

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perfluoroplastics. Perfluoroplastic means polymers of general paraffinic structure which have some or all of the hydrogen replaced by fluorine, including, inter alia, polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP) copolymer, perfluoroalkoxy (PFA) resin, homopolymers of chlorotrifluoroethylene and its copolymers with VF2, such as KEL-F~, or TFE, ethylene-chloro-trifluoroethylene (ECTFE) copolymer and its modifications, ethylenetetrafluoroethylene (ETFE) copolymer and its modifications, polyvinylidene fluoride (PVDF), and polyvinylfluoride.
The term "fluoroelastomer" as used herein shall encompass both hydrogen-containing fluoroelastomers as well as hydrogen-free perfluoroelastomers. Fluoroelastomer means any polymer exhibiting elastomeric behaviour or having a low flexural modulus, i.e. high compliance, and containing one or more fluorinated monomers having ethylenic unsaturation, such as vinylidene fluoride, and one or more comonomers containing ethylenic unsaturation. The fluorinated monomer may be a perfluorinated mono-olefin, for example hexafluoropropylene, tetrafluoroethylene, or perfluoroalkyl vinyl ethers, e.g. perfluoro (methyl vinyl ether) or (propyl vinyl ether). The fluorinated monomer may also be a partially fluorinated mono-olefin for example vinylidene fluoride,pentafluoropropylene,chlorotrifluoroethylene,and which may contain other substituents, e.g. hydrogen, chlorine or perfluoroalkoxy. The mono-olefin is preferably a straight or branched chain compound having a terminal ethylenic double bond. The elastomer preferably consists of units derived from fluorine-containing monomers. Such other monomers include, for example, olefins having a terminal ethylenic double bond, especially ethylene and propylene. The elastomer will normally consist of carbon, hydrogen, oxygen and fluorine atoms. Any fluoropolymer component may contain a functional group such as * trademark . . .
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carboxylic and sulfonic acid and salts thereof, halogen, as well as a reactive hydrogen on a side chain.
Preferred elastomers are copolymers of vinylidene fluoride and at least one other fluorinated monomer, especially one or more of hexafluoropropylene, pentafluoropropylene, tetrafluoroethylsne and chlorotrifluoroethylene. ~vailable fluoroelastomer~
include copolymers o~ vinylidene fluoride and hexafluoropropylene and tetrafluoroethylene, sold by DuPonk as VITON and by 3M as FLUOREL and by Daiken as DAIEL.
Additionally, elastomeric copolymers of vinylidene fluoride and chlorotrifluoroethylene are available from 3M as KEL-F . The use of AFLAS , which is a copolymer of TFE and propylene, as manufactured by Asahi, is also contemplated.
Preferred perfluoroelastomers include elastomeric copolymers of tetrafluoroethylene with perfluoro alkyl comonomers, such as hexafluoropropylene or perfluoro (alkyl vinyl ether) comonomers represented by / C = CF
o Rf in which Rf is a perfluoroalkyl or perfluoro ~cyclo-oxa alkyl) moiety. Particularly preferred are the perfluorovinyl ethers in which Rf iS selected from the groups -CF3, -C3F7, C~3 0~F J or - ~p2C~0 -F2CF2S03X-CF~n F

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where n = 1-4 and X = l~, Na K or F, K~LREZ, a copolymer o TFE and perfluoromethylvinyl ether (PMVE), or its modiEica-tions, is a particularly useful fluoroelastomer.
The fluoroelastomer polymer, preferhbly a latex or blend of latexes, should be eompatible with (a) ~lle Eluoro-plastic dispersion to be modifiecl, (b) t}le processing condi-tions to whicll the eomposition must be subjecte(1, an~ (c) the end use for which the material or articles containi}lg it is being manufactured.
The invention also encompasses a film comprising one or more resinous components derived from the fluid coat-ing or easting compositions hereinbefore clescribed. Such a film may be constructed as a sequence of lamellae the compo-sition of which may be varied to induce the clesired combina-15 tiOII of electrieal physical and ehemieal properties. If desired, a non-resinous component, such as a metallic com-ponent, may be interspersed among the resinous lamellae;
e.~., a thin metallie deposit to modify permeability, elec-trical, magnetic, or optical behavior of the film. The utility of such depoloyment of the film lamellae to afEect the meehanieal and ehemieal behavior of composites derived from sueh films is deseribed in Canadian applieatioll Serial No. 452,005, filed ~pril 13, 1984.
In an embodiment of the invention, tlle invention films may be supported by a member to which t~le Eilm can be bonded to provide greater strength, dimensional stablli~ty or rigidity. For example, a film aecording to the invention ..... .. ... . . .

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may be supported by any suitable reinforcement material treated where necessary to facilitate bonding o~ the films thereto. Examples of suitable reinforcement materials include, inter alia, glass, fiberglass, ceramics, graphite (carbon), PBI ~polybenzimidazole), PTFE, polyaramides, such a KEVLAR and NOMEX, metal, includin~ motal wire, polyolefin~
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such as TYVEK, polyesters such as REEM~Y, polyamides, poIy-imides, thermoplastics such as KYN~R and TEFZEL, ~olyphenylene sulfide, polyether oxides, polyether sulfones, polyether ketones, novoloid phenolic fibers such as KYNOL, cotton, asbestos and other natural as well as synthetic textiles.
The substrate may comprise a yarn, filament, monofilament or other fibrous material either as such or assembled as a textile, or any woven, non-~oven, knitted, matted, felted, etc. material.
Furthermore, the invention compositions are valu-able in the manufactuee of fluoropolymer coated te~tiles having a thick, crack-free coating matrix, without specific regard for the mechanical or other properties of the film or coating itself. For example, they may be used to reduce the number o operations required to apply a coating of a desired thickness. Such ~rocessing may result in composites which more eficiently utilize the inherent physical properties of a r~inforcement than otherwise possible.
The following additives may be included in formu-lating the composition of the fluids and films according to the invention: a surface active agent such as an anionic active agent or or non-ionic active agent; a creaming agent such as sodium or ammonium alginate; a viscosity-controlling * trade marks .. .
. . :, ~770~7 agent or a thickener such as methyl cellulose or ethyl cellulose; a wetting agent such as a fluorinated alkyl-carboxylic acid, an organic solvent, or sulfonic acid; or ` a film former.
5 In addition, relatively small amounts of cross-linking accelerators, such as triallyl isocyanurate, triallyl imidazole, and the like, may be used to cross-link one or more o~ the resins contained in the coati~g layers, as desired, by use o~ high eneryy elec~rons or actinic irradiation.
The invention and its advantages are illustrated, but are not intended to be limitcd by, the following e~amples. The examples illustrate coating compositions and films employing a variety of fluoroplastic and fluoroelastomer components contemplated by the invention.
In the accompanying drawings, which are referred in the examples: -Figures 1 and 2 show tensile stre~s/strain curves in re.qpect of the testing of polymer films.
The test procedures used for the chemical andphysical testing and property determinations for the composites prepared according to the invention and the controls are identified below:

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7~367 PROPERTY TEST PROCEDURE
Weight (oz/sq yd) US FED STD 191-5041 Thickness (ins) US FED STD 191-5030 Tensile Strength (lbs/in) ASTM D-412 Coating Adhesion (lbs/in) *
Dielectric Strength (volts) ASTM D 902 Film Elongation at brPak ASTM D-412 Tear Strength ASTM D-624 (die C) * This test measures the adherence of the coating matrix to a substrate by subjecting a specimen (prepared from two pieces of the sample composite joined face to face as in making a production type joint or seam) to an Instron Tester, Model 1130, whereby the pieces forming the specimen are separated for a special length (3") at a specified rate of strain (2"/min.). The average reading during separation is deemed the adhesion value in lbs./in.

A modified PTFE dispersion containing 60 percent by weight of PTFE and 40 percent by weight of a vinylidine fluoride/hexafluoropropylene/tetrafluoroethylene terpolymer fluoroelastomer was prepared by combining 100 parts by weight of TE-3313 (PTFE dispersion containing 60 percent by weight PTFE) and 64 parts by weight of VTR-5307 (fluoroelastomer latex containing 62.5 percent by weight fluoroelastomer). Both ingredients were purchased from E.I. DuPont de Nemours * trade-marks ~' ~S!."-, ~'~77~6~7 and Co~pany, Inc., ~ilmington, Delaware (DuPont). The resulting mixture had a specific gravity of approximately 1.45 and a viscosity of 40 centipoise, measured at 70~F., using a Brookfieid Model LVF viscometer with No. 2 spindle at 60 RPM. Two methods were ernployed to investigate the coating or casting qualities of this composition, as follows.
In Method A, a film of variable thickness was cast on a horizontal aluminum foil substrate, air dried, and baked.
The film thus provided was examined at 30X magnification for the presence of cracks. The fluid formulation was applied using a Gardner Film Casting Knife, 6 inches wide ~available from Pacific Scientific, Gardner Laboratory Division, Bethesda, Maryland) with the blade set at an angle so that clearance was close to zero at one end and between .020 to 035 inches at the other. The aluminum foil support was .0032 inches thick and was held in a horizontal plane. A quantity of the modified dispersion was filtered through paper ~code no.
01-4103-05, Schwartz ~anufacturing Co., Two Rivers, ~isconsin), vacuum de-aired for approximately 5 min~tes, and poured along one edge of the supporting foil. The film was made by slowly hand drawing the composition with a knife. The film was allowed to air dry. When dry, the supported film was placed in an air circulating oven at approximately 500F. The oven temperature was increased to 720F over a period of about 15 minutes, whereupon the specimen was removed to room tempera-ture and allowed to cool.
The film thus produced varied in thickness from approximately .OQ3 to .010 inches. There were no cracks whatsoever in that portion of the film which ~easured less 2~25 7'70~

.han .005 to .006 inches. ~hile isolated and occasional shrinkage cracks were observed in that portion of the film thicker than .006 inches, no overall mud cracking was observed even in the thickest portions of the film.
In Method B, the invention composition was cast in a film of variable thickness on a vertical substrate, and subsequently dried and baked. A foil substrate was drawn through a bath of the invention composition at rates varying between 6 and 24 inches per minute to produce a film of con-tinuously increasin~ thickness. The film was dried in air at 200 to 240F and baked for 2 minutes at 650 to 750F.
The thickness of the film thus produced was measured and found to be approximately .0015 inches at its maximum. The film was a UnirQrm cream color and was smooth and unbroken, exhibiting no mudcracking or is~lated cracks whatsoever.

An unmodified TE-3313 PTFE dispersion was evaluated by Methods A and B described in Example 1, with results shown in the table below.

A number of additional compositions were prepared and evaluated and described in Example 1, as shown in the following Table A.

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~'~'77()67 1. A PTFE dispersion, approximately 60 percent solids, pur-chased from DuPont 2. An FEP (fluorinated ethylene propylene) dispersion, approximately ~S percent solids, purchased ~rom DuPont, 3. A vinylidine-fluor~de/hexa1uoropropylene copolymer elastomer in latex form, approx~mately 55 percent solids.

4 L-9025 is a vinylidene fluoride/hexafluor~propylene/tetra-fluoroethylene terpolymer elastomer in latex form, approxi-mately 66 percent solids.

5. A tetraE~uoroethylene/propylene copolymer fluoroelastomer latex, approximately 31 percent solids A sample of C~3EMFAB TCGF 100-10, PTFE coated glass fabric nominally .010 in. thick and 14 to 15 oz~yd weight, was obta-ined and weight, dielectric breakdown, and coating adhe~ion were measured. A coating of a modified PTFE disper-sion ~repared according to Exam~le 1 was applied to this sa~ple by dipping, drying, and fusinq in a vertical coating tower by a single application. Weight, dielectric strength, 20 and coating adhesion were measured on the coated sample.
The results are shown below.

ProPerty Units 100-10Example 11 Weight oz/yd 14.9 16~2 Dielectric 1/4 inO elec. volts 7400 9000 ~reakdown 2 in. elec. 5500 8500 Coating adhes~on lbs/in. ~.0 8.9 * trade marks ~7~7~6~

The above example illustrates tl-e property of the invention composition to impr~ve the lntegrity ana uniformity of PTFE coatings. The measured increase in ~ielectric break-down strength, especially as measured with the 2 inch dia-meter electrode, is signi~icant. The coating adhesion o~the treated composite is greater than that of the original product indicating that the coating de~lved rom the inven-tion compositlon can be strongly bonded to a PTFE surface.

Invention compositions were prepared by blending Teflon 30B and VTR-5307 a~ follows:
Example 12 ~ B C D E
Teflon 308 (pbw) 66 83 99 111 116 VTR-5307 ~pbw) 97 81 65 53 48 Film5 derived from these compositions were produced by ca~ting on a carrier, drying and baking at 700F. Te.sts perormed on the materials and the results obtained are presented in Table B below. The modulus and draw values were obtained from the tensile stress/strain curves as shown in Fig. l.

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Representative tensile stress-strain curves for / each configuration of Example 12 are shown in Fig. 2. The weight percent as well as the film thickness and width of each sample is indicated parenthetically in Fig. 2.
While representative applications and embodiments of the invention have been described, those skilled in the art will recognize that many variations and modifications of such embodiments may be made without departing f~om the spirit of the invention, and it is intended to claim all such variations and modifications as fall within the true scope of the invention.

Claims

1. A fluid composition which comprises a blend of a perfluoroelastomer and a perfluoroplastic, wherein the perfluoroplastic component comprises up to about 95% by weight of the composition.

2. A fluid composition according to claim 1, which comprises a blend of about 10-95% by weight of the perfluoroplastic and about 5-90% by weight of perfluoroelastomer.

3. A fluid composition according to claim 1, wherein the perfluoroplastic comprises up to about 90% by weight of the blend.

4. A fluid composition according to claim 1, wherein the perfluoroplastic is in the form of an aqueous dispersion.

5. A fluid composition according to claim 1, wherein the perfluoroplastic is polytetrafluoroethylene or fluorinated ethylene propylene.

6. A fluid composition according to claim 1, wherein the perfluoroelastomer is a latex.

7. A fluid composition according to claim 6, wherein the perfluoroelastomer is a copolymer of tetrafluoroethylene and hexafluoropropylene or perfluoromethylvinyl ether.

8. An unsupported film comprising a resinous component derived from a composition comprising a blend of a perfluoroplastic and a perfluoroelastomer, wherein the perfluoroplastic component comprises up to about 95% by weight of the composition, and wherein said blend has been heated to a temperature sufficient to fuse the blend.

9. A film according to claim 8, which comprises a blend of about 10-95% by weight of perfluoroplastic and about 5-90% by weight of perfluoroelastomer.

10. A film according to claim 8, wherein the perfluoroplastic comprises up to about 90% by weight of the blend.

11. A film according to claim 8, wherein the perfluoroplastic is incorporated as an aqueous dispersion.

12. A film according to claim 12, wherein the perfluoroplastic is polytetrafluoroethylene, modified fluoroalkoxy resin, perfluoroalkoxy resin, or fluorinated ethylene propylene.

13. A film according to claim 8, wherein the perfluoroelastomer is incorporated as a latex.

14. A film according to claim 13, wherein the perfluoroelastomer is a copolymer of vinylidene fluoride and hexafluoropropylene, a terpolymer of vinylidene fluoride, hexafluoropropylene and tetrafluoroethylene, a copolymer of tetrafluoroethylene and propylene, a copolymer of tetrafluoroethylene and perfluoromethyl vinyl ether, a copolymer of tetrafluoroethylene and fluorinated vinyl ethers, or a copolymer of vinylidene fluoride and chlorotrifluoroethylene.

15. A film according to claim 8, comprising a sequence of lamellae wherein one or more comprise a perfluoroplastic and perfluoroelastomer blend.

16. A film according to claim 15, wherein at least one non-resinous component is top-coated upon or interspersed with other resinous lamellae.

17. A film according to claim 16, wherein the non-resinous lamellae comprises a metallic, mineral, or ceramic composition.

18. A film according to claim 15, wherein one or more of the lamellae contains a metallic, mineral, or ceramic composition.

19. A film according to claim 8, applied to a suitable reinforcement material.

20. A film according to claim 8, containing cross-linking accelerators.

21. A film according to claim 8, containing one or more additives selected from the group consisting of surface active agents, creaming agents, viscosity controlling agents, wetting agents and film formers.

22. An unsupported film comprising a resinous component derived from a composition comprising a blend of a perfluoroplastic and a perfluoroelastomer, wherein the perfluoroplastic component comprises up to about 95% by weight of the composition.

23. A film according to claim 22, wherein the composition comprises a blend of about 10-95% by weight of perfluoroplastic and about 5-90% by weight of perfluoroelastomer.

24. A film according to claim 22, wherein the perfluoroplastic comprises up to about 90% by weight of the blend.

25. A film according to claim 22, wherein the perfluoroplastic is in an aqueous dispersion.

26. A film according to claim 22, wherein the perfluoroplastic is a polytetrafluoroethylene or fluorinated ethylene propylene.

27. A film according to claim 22, wherein the perfluoroelastomer is in a latex.

28. A film according to claim 27, wherein the perfluoroelastomer is a copolymer or tetrafluoroethylene and hexafluoropropylene or perfluoromethylvinylether.

29. A film according to claim 8, wherein the blend has been heated to a temperature between 500°F and 750°F.