Fluoropolymer compositions and articles made therefrom

Abstract

A fluoropolymer composition comprising a fluoropolymer and one or more heat resistance additives selected from acridone, anthrone, diaminoanthraquinone, acridine, substituted acridone, substituted anthrone, substituted diaminoanthraquinone, and substituted acridine, and a cured fluoropolymer composition formed from by curing the fluoropolymer composition.

Description

FLUOROPOLYMER COMPOSITIONS AND ARTICLES MADE THEREFROM CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] None FIELD OF THE INVENTION

[0002] The present invention relates to a fluoropolymer composition comprising a fluoropolymer and one or more heat resistance additives and articles cured from these fluoropolymer compositions. BACKGROUND OF THE INVENTION

[0003] Elastomer compositions that comprise a fluoropolymer have achieved outstanding commercial success because they can be used in severe environments, in particular, during exposure to high temperatures and to aggressive chemicals. For example, compositions containing fluoroelastomers are used in seals in hot sections of aircraft engines, in oil-well drilling devices, as sealing elements in industrial equipment that operate at high temperatures, and in high temperature, high pressure, aqueous environments.

[0004] The properties of cured compositions containing fluoropolymers arise largely because of the stability and inertness of the copolymerized fluorinated monomers that make up the major portion of the polymeric backbone of these compounds. Such monomers include tetrafluoroethylene and perfluoro(alkyl vinyl) ethers. In order to develop elastomeric properties fully, fluoroelastomers are typically crosslinked, i.e., vulcanized or cured. To this end, a small percentage of cure site monomer is copolymerized with the fluorinated monomers. Upon crosslinking, the cure site monomers react with a curing agent to form a crosslinked fluoroelastomer in the form of an article. Various cure site monomers may be used. For example, cure site monomers comprising nitrile groups or halogen containing cure site monomers may be used. Perfluoroelastomers comprising cure site monomers may be cured by any curative suitable for use with the type of cure site monomer employed.

[0005] Although fluroelastomers perform well in severe environments, their performance can still be improved. In particular, because of the high heat environments in which cured fluoropolymer compositions are used, there is an ongoing need for fluoropolymer compositions with improved heat resistance. BRIEF SUMMARY OF THE INVENTION

[0006] The present invention is directed to a fluoropolymer composition comprising a fluoropolymer and one or more heat resistance additives selected from acridone, anthrone,diaminoanthraquinone, acridine, substituted acridone, substituted anthrone, substituted diaminoanthraquinone, and substituted acridine.

[0007] The present invention is further directed to a process comprising the step of curing a composition comprising a fluoropolymer and one or more heat resistance additives selected from acridone, anthrone, diaminoanthraquinone, acridine, substituted acridone, substituted anthrone, substituted diaminoanthraquinone, and substituted acridine.

[0008] The present invention is still further directed to an article formed from a fluoropolymer composition comprising a fluoropolymer and one or more heat resistance additives selected from acridone, anthrone, diaminoanthraquinone, acridine, substituted acridone, substituted anthrone, substituted diaminoanthraquinone, and substituted acridine.

[0009] The composition of the invention provides superior heat resistance to previous fluoropolymer compositions and articles formed from fluoropolymer compositions not containing the heat resistance additives selected from acridone, anthrone, diaminoanthraquinone, acridine, substituted acridone, substituted anthrone, substituted diaminoanthraquinone, and substituted acridine. DETAILED DESCRIPTION OF THE INVENTION

[0010] As used herein, the article "a" refers to one as well as more than one and does not necessarily limit its referent noun to the grammatical category of singular number.

[0011] As used herein, the terms “about” and “at or about”, when used to modify an amount or value, refers to an approximation of an amount or value that is more or less than the precise amount or value recited in the claims or described herein. The precise value of the approximation is determined by what one of skill in the art would recognize as an appropriate approximation to the precise value. As used herein, the term conveys that similar values, not precisely recited in the claims or described herein, can bring about results or effects that are equivalent to those recited in the claims or described herein, for which one of skill in the art would acknowledge as acceptably brought about by the similar values.

[0012] As used herein, the term “article” refers to an unfinished or finished item, thing, object, or an element or feature of an unfinished or finished item, thing or object. As used herein, when an article is unfinished, the term "article" may refer to any item, thing, object, element, device, etc., that has a form, shape, configuration that may undergo further processing in order to become a finished article. When an article is unfinished, the term ”preform” may refer to that form, shape, configuration, any part of which may undergo further processing to become finished.

[0013] As used herein, when an article is finished, the term "article" refers to an item, thing, object, element, device, etc. that is in a form, shape, configuration that is suitable for a particular use / purpose without further processing of the entire entity or a portion of it. An article may comprise one or more element(s) or subassembly(ies) that either are partially finished and awaiting further processing or assembly with other elements / subassemblies that together will comprise a finished article. In addition, as used herein, the term "article" may refer to a system or configuration of articles.

[0014] As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation of these, refer to a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not limited to only the listed elements but may include other elements not expressly listed or inherent. Further, unless expressly stated to the contrary, “or” refers to an inclusive, not an exclusive, or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

[0015] As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having”, "consisting essentially of", and "consisting of" or any other variation of these, may refer either to a non-exclusive inclusion or to an exclusive inclusion. When these terms refer to a more exclusive inclusion, these terms limit the scope of a claim to those recited materials or steps that materially affect the novel elements of the recited invention. When these terms refer to a wholly exclusive inclusion, these terms exclude any element, step or component not expressly recited in the claim.

[0016] As used herein, terms that describe molecules or polymers follow the terminology in the IUPAC Compendium of Chemical Terminology version 2.15 (International Union of Pure and Applied Chemistry) of September 7, 2009.

[0017] As used herein, the term “unsaturated fluorinated olefin” refers to linear, branched, or cyclic hydrocarbon structures that comprise at least one unsaturated double bond and comprise at least one fluorine atom.

[0018] As used herein, the term ”alkyl” refers to linear, branched, or cyclic hydrocarbon structures and combinations of there. Alkyl does not include aromatic structures. Examples of linear alkyl groups include methyl, ethyl, propyl, butyl, pentyl, and hexyl groups. Branched alkyl groups include for example s-and t-butyl, and isopropyl groups. Examples of cyclic hydrocarbon groups include cyclopropyl, cyclopentyl, cyclohexyl, cyclobutyl, and cyclooctyl groups.

[0019] As used herein, the term ”alkoxy” or “alkoxyl” refers to alkyl groups attached to an oxygen atom by a single bond. The other bond of the oxygen atom is connected to a carbon atom. Examples include methoxy, ethoxy, propoxy, isopropoxy, cyclopropyloxy, and cyclohexyloxy.

[0020] As used herein, the term “compound” refers to a composition that is able to be cured, i.e., a curable composition, as well as to a mixture of chemical entities that comprises at least a fluoroelastomer or fluoropolymer and a curing agent. The mixture of chemical entities has not been cured nor has undergone processing conditions that would cause the curing of the mixture of chemical entities to undergo curing. As used herein, the term may be used interchangeably with the term “composition” when used to refer to a curable composition.

[0021] As used herein, the prefix term “fluoro”, when placed as a prefix before a chemical entity name, refers to a chemical entity that has at least one fluorine atom as exemplified by the following designations: fluoroelastomers, perfluoroelastomers, fluorovinyl, and perfluorovinyl ethers. The prefix “fluoro”, when placed as a prefix before a chemical entity name, expressly includes “perfluoro” chemical entities. Thus, the prefix “fluoro”, when preceding a chemical entity name, indicates both “fluoro-“ entities and “perfluoro-“ entities.

[0022] As used herein, the term “aromatic” refers to a chemical entity comprising at least one unsaturated ring of atoms that are stabilized by an interaction of the bonds forming the ring. Such chemical entities are typified by benzene and naphthalene.

[0023] As used herein, the term “phenyl” refers to a chemical entity having the formula -C6H5derived from benzene by removal of one hydrogen atom. The carbon atom lacking thehydrogen atom is used to form a bond to another chemical entity.

[0024] As used herein, the term “cured” refers to that resultant entity that comprised a fluoroelastomer and / or fluoropolymer and which has been exposed to those conditions that caused the fluoroelastomer or fluoropolymer molecules to form sufficient crosslinks among themselves (that is, curing conditions) such that the resultant entity takes on a form or shape or configuration or structure that cannot be reprocessed, molded, or extruded into a different one. That is, once a resultant entity that comprised a fluoroelastomer or fluoropolymer has been exposed to curing conditions to thereby be cured, that entity cannot be re-cured in order to assume a substantially different form or structure.

[0025] As used herein, the term “curing” refers to that processing of a compound, also called herein curable composition, which results in an entity taking on a form or shape orconfiguration or structure that cannot be reprocessed, molded, or extruded into a different one. Such processing refers to the “curing process / processing”, which requires compounds to be exposed to certain conditions in order to initiate the curing process, such conditions called curing conditions. The resultant entity of the curing process is a “cured” entity, that is, an article as defined hereinabove. To be clear, curing results in compounds taking on a form or shape or configuration or structure of an article. Cured articles of compounds described herein include, but are not limited to, O-rings, seals, and gaskets. The terms “curing”, “cured” also expressly include differing degrees of processing of a compound such that the resultant entity takes on a form or shape or configuration or structure that cannot be reprocessed, molded, or extruded into a different one and which may exhibit certain physical properties as a result of the curing. To the point, these compounds may be initially cured to achieve a non- reprocessable form, shape, etc., which has been termed “cured” herein. The cured compounds may be further subjected to additional curing conditions, which provide additional, subsequent curing. Such additional curing conditions may be variously termed herein either as “curing” or as “postcuring”. That is, the terms “curing”, “cured” refer to both an initial curing process that results in a first cured, resultant entity and also expressly refer to any subsequent curing process that results in a subsequently cured, resultant entity that may or not possess different material or physical properties than those of the first cured, resultant entity.

[0026] Any range set forth herein expressly includes its endpoints unless explicitly stated otherwise. Setting forth an amount, concentration, or other value or parameter as a range specifically discloses all possible ranges formed from any possible upper range limit and any possible lower range limit, regardless of whether such pairs of upper and lower range limits are expressly disclosed herein. Compounds, processes and articles described herein are not limited to specific values disclosed in defining a range in the description.

[0027] The disclosure herein of any variation in terms of materials, chemical entities, methods, steps, values, and / or ranges, etc.—whether identified as preferred or not—of the processes, compounds and articles described herein specifically intends to include any possible combination of materials, methods, steps, values, ranges, etc. For the purpose of providing photographic and sufficient support for the claims, any disclosed combination is a preferred variant of the processes, compounds, and articles described herein.

[0010] In this description, if there are nomenclature errors or typographical errors regarding the chemical name any chemical species described herein, the chemical structure takes precedence over the chemical name. And, if there are errors in the chemical structures ofany chemical species described herein, the chemical structure of the chemical species that one of skill in the art understands the description to intend prevails.

[0028] A fluoropolymer composition, comprising: a. a fluoropolymer; and b. one or more heat resistance additives selected from acridone, anthrone, diaminoanthraquinone, acridine, substituted acridone, substituted anthrone, substituted diaminoanthraquinone, and substituted acridine.

[0029] The fluoropolymer composition comprises a fluoropolymer. The fluoropolymer comprises polymerized units of one or more, alternatively two or more, fluorinated olefins. The fluorinated olefins may be the same or different, alternatively, when two or more fluorinated olefins are copolymerized, the fluorinated olefins are different from each other. Each fluorinated olefin is independently selected from the group consisting of fluorovinyl ethers, unsaturated fluorinated olefins, unsaturated olefins, and mixtures of fluorovinyl ethers, unsaturated fluorinated olefins, and unsaturated olefins.

[0030] In one embodiment, the fluorinated vinyl olefins comprise additional hologen atoms, alternatively chlorine, in addition to fluorine.

[0031] Examples of the fluorinated olefins include, but are not limited to, halo (alkyl vinyl) ethers, perfluoroolefins, perfluoro(alkyl vinyl) ethers (PAVE) and perfluoroalkoxyalkyl vinyl ethers (PAAVE)), fluoro (methoxy vinyl) ethers (MOVE), fluoro (alkene ether), halogenated fluoroolefins such as chlorotrifluoroethylene (CTFE)), partially fluorinated olefins such as vinyl fluoride (VF), vinylidene fluoride (VF2), trifluoroethylene, tetrafluoropropene (TFP), pentafluoropropene (HPFP), an olefin in which less than half or less than one-fourth of the hydrogen atoms are replaced with fluorine, an olefin according to the formula CX2=CXR, where each X is independently hydrogen, fluoro, or chloro and R is hydrogen, fluoro, or a C1- C12, alternatively C1to C3, alkyl, with the proviso that all X and R groups are not fluoro groups, hydrogen-containing monomers such as ethylene, propylene, and other non- fluorinated alpha-olefins such as a C2to C9alpha olefin, fluorinated ester ethers such as fluorinated estervinylether, methyl perfluoro(5-methyl-4,7-dioxanon-8-enoate) (EVE), or perfluoro(4-methyl-3,6-dioxaoct-7-ene)sulfonyl fluoride (PSEPVE), perfluoro(3- methoxypropyl vinyl ether) (MV-31), perfluoro and nitrogen-containing cure site monomers. One skilled in the art would know where to find or how make the fluorinated olefins, and many of these additional monomers are available commercially.

[0032] Examples of the halo (alkyl vinyl) ether include, but are not limited to, 2- (difluoromethoxy)-1,1-difluoroethene (HHPMVE), 1,1-difluoro-2-(trifluoromethoxy)ethene,1,1-difluoro-2-(chlorodifluoromethoxy)ethene, 1,1-difluoro-2-(bromodifluoromethoxy)ethene, 1,1-difluoro-2-(1,1,2,2-tetrafluoroethoxy)ethene, 2-(pentafluoro)ethoxy-1,1-difloroethene, 1,1,2,2,3,3-hexafluro-1-(1,1-difluoroethenoxy)propane, 1-(1,1- difluoroethenoxy)perfluoropropane, 1-(1,1-difluoroethenoxy)perfluorobutane, 1-(1,1- difluoroethenoxy)perfluoroisobutane, 1-(1,1-difluoroethenoxy)perfluoro-sec-butane, 1-(1,1- difluoroethenoxy)perfluoropentane, 1-(1,1-difluoroethenoxy)difluoroethenoxy)perfluorocyclohexane, 1-(1,1-difluoroethenoxy)perfluorooctane, 1-(1,1- difluoroethenoxy)perfluorononane, 1-(1,1-difluoroethenoxy)perfluorodecane.

[0033] The halo (alkyl vinyl) ether may be prepared by heating a reaction mixture comprising a metal; a solvent; and a halo (alkyl ethyl) ether according to the formula RCF2OC(H)(X)CF2Y, where R is independently H, F, Cl. Br, CF2H, CF3,CF2CF2H, linear perfluoroalkyl having 1 to 12 carbon atoms, or cyclic perfluoroalkyl having 1 to 12 carbon atoms, and X and Y are independently Cl, Br, I, or F, where X and Y are not both F; to form a reaction product mixture comprising the halo (alkyl vinyl) ether, the solvent, unreacted metal, and metal salts. Other methods known in the art may also be used to the halo (alkyl vinyl) ether.

[0034] Examples of perfluoroolefins include, but are not limited to, tetrafluoroethylene (TFE), hexafluoropropylene (HFP), or any perfluoroolefin of the formula CF2=CF-Rf, where Rfis fluorine or a perfluoroalkyl of 1 to 8, alternatively 1 to 3, carbon atoms.

[0035] Examples of PAAVE monomers include, but are not limited to, those according to the formula CF2=CF-ORf, wherein Rf is a linear, branched, or cyclic perfluorinated alkyl group optionally containing ether linkages, and CF2=CF(OCnF2n)pORf, wherein Rf is a perfluorinated (C1-C8) alkyl group optionally containing ether linkages, each n is independently 1 to 4, and p is 1 to 6. When more than one CnF2n group is present, “n” may be independently selected, alternatively n is from 1 to 12, alternatively 1 to 6. However, within a CnF2ngroup, a person skilled in the art would understand that “n” is not independently selected. CnF2nmay be linear or branched. In some embodiments (OCnF2n)pis represented by -O-(CF2)1-4-[O(CF2)1-4]0-1. Such perfluorinated ethers are described, for example, in U.S. Pat. Nos.6,255,536 and 6,294,627 (each to Worm et al.) Examples of suitable PAAVE monomers include, but are not limited to, CF2=CFOCF2OCF3, CF2=CFOCF2OCF2CF3, CF2=CFOCF2CF2OCF3, CF2=CFOCF2CF2CF2OCF3(MV-31), CF2=CFOCF2CF2CF2CF2OCF3, CF2=CFOCF2CF2OCF2CF3, CF2=CFOCF2CF2CF2OCF2CF3, CF2=CFOCF2CF2CF2CF2OCF2CF3, CF2=CFOCF2CF2OCF2OCF3, CF2=CFOCF2CF2OCF2CF2OCF3, CF2=CFOCF2CF2OCF2CF2CF2OCF3,CF2=CFOCF2CF2OCF2CF2CF2CF2OCF3, CF2=CFOCF2CF2OCF2CF2CF2CF2CF2OCF3, CF2=CFOCF2CF2(OCF2)3OCF3, CF2=CFOCF2CF2(OCF2)4OCF3, CF2=CFOCF2CF2OCF2OCF2OCF3, CF2=CFOCF2CF2OCF2CF2CF3 CF2=CFOCF2CF2OCF2CF2OCF2CF2CF3, CF2=CFOCF2CF(CF3)-O-C3F7(PPVE-2), CF2=CF(OCF2CF(CF3))2-O-C3F7(PPVE-3), and CF2= CF(0CF2CF(CF3))3-O-C3F7(PPVE-4). Methods of making PAAVE monomers are known in the art. Many of the PAAVE monomers are available commercially.

[0036] Examples of suitable PAVE monomers include, but are not limited to, perfluoro(methyl vinyl) ether CF2=CFOCF3, perfluoro(ethyl vinyl) ether CF2=CFOCF2CF3, and perfluoro(n-propyl vinyl) ether CF2=CFOCF2CF2CF3. Mixtures of PAVE and PAAVE may also be employed. Methods of making PAVE monomers are known in the art. Many of the PAVE monomers are available commercially.

[0037] Examples of suitable MOVE monomers include, but are not limited to, those defined in US 7,160,967 B2 such as perfluoro-3,5-dioxa-1-heptene (MOVE 1)(CF2=CFOCF2OCF2CF3) and perfluoro-3,5,8-trioxa-1-nonene(CF3OCF2CF2OCF2OCF=CF2) (MOVE 2). One skilled in the art would know how to makeMOVE monomers. Many MOVE monomers are commercially available.

[0038] Examples of fluoro (alkene ether) monomers include, but are not limited to, those described in U.S. Pat. Nos.5,891 ,965 (Worm et al.) and 6,255,535 (Schulz et al.). Such monomers include those represented by formula CF2=CFCF2(OCnF2ll)pORf, wherein n, p, and Rf are as defined above for the PAAVE monomers. Examples of suitable fluoro (alkene ether) monomers include perfluoroalkoxyalkyl allyl ethers such as CF2=CFCF2OCF2CF2OCF3, CF2=CFCF2OCF2CF2CF2OCF3, CF2=CFCF2OCF2OCF3CF2=CFCF2OCF2OCF2CF3, CF2=CFCF2OCF2CF2CF2CF2OCF3, CF2=CFCF2OCF2CF2OCF2CF3, CF2=CFCF2OCF2CF2CF2OCF2CF3, CF2=CFCF2OCF2CF2CF2CF2OCF2CF3, CF2=CFCF2OCF2CF2OCF2OCF3, CF2=CFCF2OCF2CF2OCF2CF2OCF3, CF2=CFCF2OCF2CF2OCF2CF2CF2OCF3, CF2=CFCF2OCF2CF2OCF2CF2CF2CF2OCF3, CF2=CFCF2OCF2CF2OCF2CF2CF2CF2CF2OCF3, CF2=CFCF2OCF2CF2(OCF2)3OCF3, CF2=CFCF2OCF2CF2(OCF2)4OCF3, CF2=CFCF2OCF2CF2OCF2OCF2OCF3, CF2=CFCF2OCF2CF2OCF2CF2CF3, CF2=CFCF2OCF2CF2OCF2CF2OCF2CF2CF3, CF2=CFCF20CF2CF(CF3)-0-C3F7, and CF2=CFCF2(0CF2CF(CF3))2-0-C3F7. Many of these perfluoroalkoxyalkyl allyl ethers can be prepared, for example, according to the methods described in U.S. Pat. No.4,349,650 (Krespan). Also, perfluoropropyl allyl ether (CF2=CF-CF2-OC3F7) and perfluoromethoxy ethyl allyl ether (CF2=CF-CF2-0C2F40CF3) can be prepared according to the methods described in U.S. Pat. No. US Pat. No.5,891,965 (Worm). Perfluoroalkoxyalkyl allyl ethers can also be prepared by combining first components comprising at least one of CF2=CF-CF2-OSO2C1 or CF2=CF- CF2- OSO2CF3, a polyfluorinated compound comprising at least one ketone or carboxylic acid halide or combination thereof, and fluoride ion. Polyfluorinated compounds comprising at least one ketone or carboxylic acid halide or combination thereof and fluoride ions can be any of those described, for example, in U.S. Pat. No.4,349,650 (Krespan). Many fluoro (alkene ether) monomers such as perfluoroalkoxyalkyl allyl ether monomers are available commercially.

[0039] In one embodiment, the fluorinated polymer further comprises, as a polymerized unit, one or more cure site monomers. Cure sites in the fluoropolymer enable curing the fluoropolymer to form cured fluoropolymers including a fluoroelastomer. In one embodiment, the cure site monomer is selected from the group consisting of nitrile-containing fluorinated olefins and nitrile-containing fluorinated vinyl ethers. Examples of cure sites in the cure site monomers include, but are not limited to, free-radically polymerizable nitriles, imidates, amidines, amides, imides, and amine-oxides. Mixtures of any of these cure site monomers may be useful in the fluoropolymer compositions according to the present disclosure. Useful nitrile-containing fluorinated olefins and fluorinated vinyl ethers include, but are not limited to, CF2=CFO(CF2)LCN, CF2=CFO(CF2)uOCF(CF3)CN, CF2=CFO[CF2CF(CF3)O]q(CF2O)yCF(CF3)CN, CF2=CFO[CF2FCF3O]nCF2-CFCF3CN or CF2=CF[OCF2CF(CF3)]rO(CF2)tCN, wherein L is in a range from 2 to 12; u is in a range from 2 to 6; q is in a range from 0 to 4; y is in a range from 0 to 6; n is in a range from 0 to 4; r is in a range from 1 to 2; and t is in a range from 1 to 4. Examples of such nitrile-containing cure site monomers include, but are not limited to, CF2=CFO(CF2)3OCF(CF3)CN, perfluoro(8-cyano-5-methyl-3,6-dioxa-l-octene) (8-CNVE), and CF2=CFO(CF2)5CN.

[0040] Nitrile-containing cure sites can also be incorporated into the curable fluoropolymer by employing selected chain transfer agents (e.g., I(CF2)dCN in which d is 1 to 10 or 1 to 6) or by carrying out the free-radical polymerization in the presence of a perfluorosulfinate such as NC(CF2)dSO2G, in which G represents a hydrogen atom or a cation with valence of 1 or 2.

[0041] The nitrile-containing monomer, chain transfer agent, and / or initiator typically makes up about 0.1 to 5 mole percent (in some embodiments, 0.3 to 2 mole percent) of the polymerization components.

[0042] The fluoropolymers provided herein may further, or alternatively, comprise at least one halogen atoms cure site capable of participating in, for example, a peroxide cure reaction. The halogen capable of participating in a, for example, peroxide cure reaction can be bromine or iodine, alternatively iodine. The halogen atom capable of participating in the peroxide cure reaction may be located at a terminal or internal position of the backbone chain, alternatively is located at a terminal position of the backbone chain. However, further reactive cure sites may also be present when the location of the halogen atom capable of participating in the peroxide cure reaction is located at a terminal position. The amount of iodine, bromine or the combination thereof contained in the fluoropolymer is between 0.001 and 5%, preferably between 0.01 and 2.5%, or 0.1 to 1% or 0.2 to 0.6% by weight with respect to the total weight of the fluoropolymer.

[0043] In one embodiment, halogen cure sites are incorporated into the perfluoropolymer by incorporating monomers comprising one or more bromine atoms and / or one or more iodine atoms or mixtures of monomers comprising bromine and / or iodine atoms and / or nitrile containing groups.

[0044] Such fluorinated monomers comprising one or more bromine and / or one or more iodine atoms are according to formula (I) or (II): CR2R2═(CR3R4)n—CR5R6(I) where n=1-4; R1, R2, R3, R4, and R5are H or F wherein at least one of R1to R5is F; and R6is Br or I, preferably I; or CF2═CF-O(CR7R8)n-R9(II) where n=1-4; R7and R8are H or F wherein at least one of R7or R8is F; and R9is Br or I, alternatively I.

[0045] Examples of the cure site monomers capable of participating in the peroxide cure reaction when incorporated in the fluoropolymer include, but are not limited to, CF2═CHBr, CH2═CHCH2Br, CF2═CFCF2Br, CH2═CHCF2CF2Br, CF2═CHI, CH2═CHCH2I, CF2═CFCF2I, CH2═CHCF2CF2I, CF2═CFOC4F8I (MV4I), CF2═CFOC2F4I, CF2═CFOCF2CF(CF3)OC2F4I, CH2═CHCF2CF2I, CF2═CFOCF2CF2CH2I, CF2═CFOCF2CF2CH2CH2I, CF2═CFOC4F8CH2CH2I, and combinations thereof.

[0046] A perfluoroelastomer comprising a cure site can also be obtained by a polymerization method carried out using and / or chain transfer compound comprising bromine or an iodine compound as the chain transfer agent.

[0047] Typical examples of the bromine compound or iodine chain transfer compound used include compounds represented by the formula (III): R10IxBry(III) wherein x and y are each an integer of 0 to 2 and satisfy 1 ≤x+y ≤2; and R10 is a saturated or unsaturated fluorohydrocarbon group or chiorofluorocarbon group having 1 to 16 carbon atoms or is a hydrocarbon group having 1 to 3 carbon atoms that optionally includes an oxygen atom. By using a bromine compound or an iodine compound, the iodine or bromine is introduced into the polymer and may function as a crosslinking point.

[0048] Examples of the bromine compound or iodine compound chain transfer agent include, but are not limited to, 1,3-diiodoperfluoropropane, 2-iodoperfluoropropane, 1,3- diiodo-2-chloroperfluoropropane, 1,4-diiodoperfluorobutane, 1,5-diiodo-2,4- dichloroperfluoropentane, 1,6-diiodoperfluorohexane, 1,8-diiodoperfluorooctane, 1,12- diiodoperfluorododecane, 1,16-diiodoperfluorohexadecane, diiodomethane, 1,2- diiodoethane, i,3-diiodo-n-propane, CF2Br2, BrCF2CF2Br, CF3CFBrCF2Br, CFClBr2, BrCF2CFClBr, CFBrClCFClBr, BrCF2CF2CF2Br, BrCF2CFBrOCF3, 1-bromo-2- iodoperfluoroethane, 1-bromo-3-iodoperfluoropropane, 1-bromo-4-iodoperfluorobutane, 2- bromo-3-iodoperfluorobutane, 3-bromo-4-iodoperfluorobutene- 1,2-bromo-4- iodoperfluorobutene, and monoiodomonobromo-substituted products, diiodomonobromo- substituted products, and (2-iodoethyl)-and (2-bromoethyl)-substituted products of benzene. These compounds may be used singly or may be used in combination with each other. Among these, from the viewpoint of polymerization reactivity, crosslinking reactivity, and availability, it is preferable to use 1,4-diiodoperfluorobutane, 1,6-diiodoperfluorohexane, and 2-iodoperfluoropropane.

[0049] Liquid monomers used to make the fluoropolymer may be pre-emulsified with an emulsifier before polymerization with other monomers, for example, addition of a gaseous fluoroolefin.

[0050] The fluoropolymer may be cured, not curable, or curable, alternatively the fluoropolymer is curable, alternatively non-curable, alternatively cured. One skilled in the art would understand what a cured, non-curable, or curable fluoropolymer is and how to make afluoropolymer that is non-curable or curable. In one embodiment, a curable fluoropolymer may be made by copolymerizing with a monomer comprising a cure site.

[0051] The fluoropolymer may be an amorphous or non-amorphous. Examples of amorphous fluoropolymers include, but are not limited to, a fluoroelastomer gum or a perfluoroelastomer gum made from the halo (alkyl vinyl) ether of the invention, a monomer with cure site, and additional monomers to give a gum with desirable properties.

[0052] The fluoropolymer composition comprises one or more heat resistance additives selected from acridone, anthrone, diaminoanthraquinone, acridine, substituted acridone, substituted anthrone, substituted diaminoanthraquinone, and substituted acridine; alternatively selected from acridone, anthrone, diaminoanthraquinone, and acridine; alternatively the heat resistant additive is acridone, alternatively anthrone, alternatively diaminoanthraquinone, alternatively acridine. In one embodiment, the heat resistant additive is diaminoanthraquinone, alternatively 1,5-diaminoanthraquinone.

[0053] In one embodiment, the substitute groups of the substituted acridone, substituted anthrone, substituted diaminoanthraquinone, and substituted acridine may be known substitute groups and are not limited, alternatively the substitute groups may include, but are not limited to, linear and / or branched alkyl , haloalkyl, alkenyl, alkynyl, acrylate functional groups, and methacrylate functional groups; halo, glycidyl, amine, ether, cyanate ester, isocyano, ester, carboxylic acid, carboxylate salt, succinate, anhydride, mercapto, sulfide, sulfate, sulfinyl, sulfonyl, azide, phosphonate, phosphine, masked isocyano, hydroxyl, and organo-functional groups comprising any of the aforementioned groups.

[0054] The structures of the heat resistant additives acridone, anthrone, diaminoanthraquinone, and acridine follow: Acridone Anthrone1,5-Diaminoanthroquinone AcridineO NH2

[0055] Methods of making acridone, anthrone, diaminoanthraquinone, acridine and substituted acridone, anthrone, diaminoanthraquinone, acridine are known in the art. Acridone, anthrone, diaminoanthraquinone, acridine, and many substituted acridone, anthrone, diaminoanthraquinone, acridine compounds are available commercially.

[0056] The perfluoroelastomers employed in the compounds of the present invention are capable of undergoing crosslinking reactions with any of the known curatives for perfluoroelastomers such as, but not limited to, polyhydroxy compounds such as the combination of organic peroxides and polyfunctional coagents (U.S. Pat. Nos.4,214,060; 4,983,680), organotin (U.S. Pat. No.5,789,489), bis(aminophenols) such as diaminobisphenol AF (U.S. Pat. No.6,211,319 B1), aromatic tetraamines such as 3,3'- diaminobenzidene, 2,2-bis[3-amino-4-(N-phenylamino)phenyl] hexafluoropropane, and ammonia generating compounds such as urea, urea derivatives, such as guanylthiourea, and other compounds disclosed in U.S. Pat. No.6,281,296 and WO 01 / 27194.

[0057] One curing agent that may be employed is an organic peroxide / polyfunctional coagent system. Useful organic peroxides are those which generate free radicals at curing temperatures. A dialkyl peroxide or a bis(dialkyl peroxide) which decomposes at a temperature above 50 °C is especially preferred. In many cases it is preferred to use a ditertiarybutyl peroxide having a tertiary carbon atom attached to a peroxy oxygen. Among the most useful peroxides of this type are 2,5-dimethyl-2,5-di(tertiarybutylperoxy)hexyne-3 and 2,5-dimethyl-2,5-di(tertiarybutylperoxy)-hexane. Other peroxides can be selected from such compounds as dicumyl peroxide, dibenzoyl peroxide, tertiarybutyl perbenzoate, and di[1,3-dimethyl-3-(t-butylperoxy)butyl]carbonate. When present in the curable compositions of the invention, 1-5 phr peroxide is typically used.

[0058] The polyfunctional coagent employed with an organic peroxide is a polyunsaturated compound that is capable of cooperating with the peroxide to provide a useful cure. Thesecoagents can be added in an amount equal to 0.1 and 10 phr, preferably between 2-5 phr. The coagent may be one or more of the following compounds: triallyl cyanurate; triallyl isocyanurate; poly triallyl isocyanurate, tri(methallyl)isocyanurate; tris(diallylamine)-s-triazine; triallyl phosphite; N,N-diallyl acrylamide; hexaallyl phosphoramide; N,N,N',N'-tetraalkyl tetraphthalamide; N,N,N',N'-tetraallyl malonamide; trivinyl isocyanurate; 2,4,6-trivinyl methyltrisiloxane; and tri(5-norbornene-2-methylene)cyanurate. Particularly useful is triallyl isocyanurate (TAIC).

[0059] Other curatives which may be employed in the compounds of the invention include bis(aminophenols) such as diaminobisphenol AF, tetraamines, organotin and compounds which decompose to produce ammonia at curing temperatures, e.g. urea. When present in the compounds of this invention, typically 0.1 to 7 phr of any one of the latter curatives is employed.

[0060] Additional additives that are commonly used in curable fluoropolymer compositions may be included in the curable fluoropolymer composition of the invention. One skilled in the art would know common additives used such as, for example, fillers; metal sulfide, a non- perfluoro-containing elastomer capable of independently cross-linking with any perfluoroelastomer (A) cure sites; stabilizers; plasticizers; lubricants; fillers; and processing aids.

[0061] Examples of metal sulfide include, but are not limited to, calcium sulfide, magnesium sulfide, manganese sulfide, iron sulfide, and copper sulfide. The concentration of metal sulfide is generally from about 0.1 to 20 phr, preferably from 1 to 20 phr, more preferably from 5 to 20 phr.

[0062] Examples of the non-perfluoro-containing elastomer are those having, at least at either its main chain or an end of its side chain, at least one kind of crosslinkable group selected from the group consisting of: cyano (-CN), carboxyl (-COOH), alkoxycarbonyl (- COOR9, where R9is a monovalent organic group), and an acid halide group (-COX1, where X1is a halogen atom) capable of a crosslinking reaction with perfluoroelastomer (A).

[0063] Examples of non-perfluoro-containing elastomers include, but are not limited to, a fluorine-containing, but not a perfluoro-containing, rubber; a thermoplastic fluorine-containing rubber; and a rubber composition comprising a fluorine-containing rubber.

[0064] The fluorine-containing rubber may contain a monomer unit independently selected from the group consisting of vinylidene fluoride (VDF), tetrafluoroethylene, and hexafluoropropylene, and at least one additional monomer such as tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl ether), chlorotrifluoroethylene, trifluoroethylene,trifluoropropylene, pentafluoropropylene, trifluorobutene, tetrafluoroisobutene, vinyl fluoride, and iodine-containing fluorinated vinyl ethers, ethylene, propylene, alkyl vinyl ether, and combinations of these. One skilled in the art would know how to make non-perfluoro- containing elastomers.

[0065] Examples of fillers include, but are not limited to, carbon black and non-carbon black fillers such as anhydrous silica (e.g., acidic silica or fumed silica). Such silicas are available from Degussa Aktiengesellschaft (Frankfurt, Germany) under the Aerosil® trademark. A particularly useful type is Aerosil® 200 silica. Other suitable silicas include Reolosil® silicas, available from Tokuyama KK (Tokyo, Japan), for example Reolosil® QS13, Reolosil® QS102, and Reolosil® QS30. Filler amounts range from 1 to 25 phr, but preferably no more than 1 to 7 phr.

[0066] Additional types of fillers include micropowders or fluoroadditives. Micropowders are ordinarily partially crystalline polymers. Micropowders include finely divided, easily dispersed plastic fluoropolymers that are solid at the highest temperature utilized in fabrication and curing of the compounds described herein. The term “solid” refers to a plastic fluoropolymer that has a crystalline melting temperature above the processing temperature(s) of the compounds described herein.

[0067] Micropowders that can be used in these compounds include, but are not limited to, micropowders based on the group of polymers known as tetrafluoroethylene (TFE) polymers. This group includes polytetrafluoroethylene (PTFE) and copolymers of TFE with small concentrations of about 1 mole percent or less of at least one copolymerizable modifying monomer such that the micropowders do not melt or soften during processing of perfluoroelastomer A that comprise the micropowders. The modifying monomer may be, for example, hexafluoropropylene (HFP), perfluoro(propyl vinyl) ether (PPVE), perfluorobutyl ethylene, chlorotrifluoroethylene, or another monomer that introduces side groups into the polymer molecule.

[0068] Tetrafluoroethylene polymers used as additives in these compounds include copolymers of TFE having sufficient concentrations of copolymerized units of one or more monomers to reduce the melting point below that of PTFE. Such copolymers generally have melt viscosity in the range of 0.5-60×103Pa ^s, but viscosities outside this range are also known. Perfluoroolefins and perfluoro(alkyl vinyl) ethers are preferred comonomers. Hexafluoropropylene and perfluoro(propyl vinyl) ether are most preferred. Examples of TFE copolymers include TFE / hexafluoropropylene copolymer and TFE / perfluoro(propyl vinyl)ether copolymers, provided they satisfy constraints on melting temperature with respectto perfluoroelastomer processing temperature. These copolymers can be utilized in powder form as isolated from the polymerization medium, if particle size is acceptable, or they can be ground to suitable particle size starting with stock of larger dimensions.

[0069] The fluoropolymer compositions described herein may be compounds, which may be prepared by mixing until homogeneous perfluoropolymer and the heat resistant additive and any other components in the fluoropolymer composition such as curing agent(s), filler, using known rubber compounding procedures such as a two-roll rubber mill, an internal mixer, or in an extruder. These compositions and compounds may be cured by the application of heat and / or of pressure sufficient to cause, for example, the curing agent to form crosslinks with cure site or a dual cure system may also be used. When compression molding is used to cure, a press cure cycle is preferably followed by a post cure cycle to achieve optimal state of cure during which the press cured compound is heated at elevated temperatures in excess of 200° C. for several hours.

[0070] When cured, the compositions described herein become articles described herein and exhibit suitable thermal stability and chemical resistance for the applications in which these articles are used. These articles are useful: as seals and gaskets for high temperature contexts, in a wide range of chemical environments, in seals for high temperature automotive uses, and O-rings.

[0071] The compounds of the present invention are useful in production of gaskets, tubing, seals and other molded components. Such articles are generally produced by molding a compounded formulation of the fluoropolymer composition with various additives under pressure, curing the part, and then subjecting it to a post cure cycle. The cured compositions have excellent mechanical properties as well as excellent thermal stability and chemical resistance.

[0072] The fluoropolymer composition of the present invention shows improved weight loss and compression set properties. EXAMPLES

[0002] The following examples are presented to better illustrate the method of the present invention, but are not to be considered as limiting the invention, which is delineated in the appended claims. Unless otherwise noted, all parts and percentages reported in the examples are by weight. The following table describes the abbreviations used in the examples:Table 1. List of abbreviations used in the examples. (Not all of these are used in the examples) Abbreviation Word g gram of t. ts hrFFKM 1: an uncured perfluorinated fluoropolymer prepared with nitrile cure site monomers and at least one fluorine containing monomer as described above. FFKM 2: an uncured perfluorinated fluoropolymer prepared with iodine cure sitesFFKM 3: an uncured perfluorinated fluoropolymer prepared with iodine cure sites Weight loss: weight loss was tested by placing cured O-rings an air oven at 300 degrees C for six weeks. After each week, the part was removed and the weight measured and weight loss calculated. Compounding of compositions: curable compositions containing ingredients shown in Tables 2, 3, and 4 were made by compounding these ingredients in a conventional manner using an internal mixer and / or a two-roll rubber mill. The properties of the compositions are also shown in Tables 2, 3, and 4. O-rings: O-rings for weight loss testing were made by molding and curing using conventional methods. Cure: cure was done according to conventional methods and tested using an MDR to ensure proper cure. Compression set: compression set was conducted according to ASTM D395 under the conditions listed in Table 3 and 4. Table 2. Compositions compounded for curing into O-rings and testing for weight loss. Recipe in phr Comp. EXAMPLE EXAMPLE EXAMPLE EXAMPLE EXAMPLE 1 2 3 42 wk weight change -13.88 -8.03 -9.25 -5.06 -4.11 (%) o kTable 3. Compositions compounded for compression set and weight loss Comp. Recipe in phr EXAMPLE 5 EXAMPLE 6 EXAMPLE 7 EXAMPLE 2Table 4. Compositions compounded for compression set and weight loss continued. Comp. EXAMPLERecipe in phr 3EXAMPLE 8 EXAMPLE 9 EXAMPLE 10

Claims

That which is claimed is:

1. A fluoropolymer composition, comprising: a. a fluoropolymer; and b. one or more heat resistance additives selected from acridone, anthrone, diaminoanthraquinone, acridine, substituted acridone, substituted anthrone, substituted diaminoanthraquinone, and substituted acridine.

2. The fluoropolymer composition according to claim 1, further comprising c) a curing agent, and wherein the fluoropolymer is curable and is a copolymer derived from a cure site monomer and at least one fluorine containing monomer.

3. The fluoropolymer compound according to claim 2, wherein the cure site monomer is a nitrile cure site monomer. Add guanyl thirourea as dependent claim.

4. The fluoropolymer compound according to claim 3, wherein the cure site monomer is perfluoro(8-cyano-5-methyl-3,6-dioxaoct-1-ene), CF2=CF-O(CF2)nCN (linear CNVE), CF2=CF-O[CF2-CFCF3-O]n-CF2-CFCF3CN, or CF2=CF- [OCF2CFCF3]x-O-(CF2)nCN, CF2=CF-O-(CF2)n-O-CF(CF3)CN.

5. The fluoropolymer composition according to claim 2, wherein the fluorine containing monomer is one or more monomers selected from the group consisting of tetrafluoroethylene (TFE), vinyl fluoride (VF), a perfluoro(alkyl vinyl) ethers (PAVE), ethylene, tetrafluoropropene (TFP), ester vinyl ether, methyl perfluoro(5-methyl-4,7-dioxanon-8-enoate) (EVE), perfluoro(4-methyl-3,6- dioxaoct-7-ene)sulfonyl fluoride (PSEPVE), vinylidene fluoride (VF2), hexafluoropropylene (HFP), chlorotrifluoroethylene (CTFE), propylene (P), perfluoro-3,5-dioxa-1-heptene (MOVE 1) and perfluoro-3,5,8-trioxa-1-nonene (MOVE 2), pentafluoropropene (HPFP), perfluoro(3-methoxypropyl vinyl) ether (MV-31), 2-(difluoromethoxy)-1,1-difluoroethene (HHPMVE), and their analogs.

6. The fluoropolymer composition according to any one of the preceding claims wherein the substituted acridone, substituted anthrone, substituted diaminoanthraquinone, and substituted acridine are substituted with a group selected from linear alkyl, branched alkyl , haloalkyl, alkenyl, alkynyl, acrylate functional groups, and methacrylate functional groups; halo, glycidyl, amine,ether, cyanate ester, isocyano, ester, carboxylic acid, carboxylate salt, succinate, anhydride, mercapto, sulfide, sulfate, sulfinyl, sulfonyl, azide, phosphonate, phosphine, masked isocyano, and hydroxyl.

7. The fluoropolymer composition according to any one of the preceding claims wherein the diaminoanthraquinone is 1,5-diaminoanthraquinone.

8. The fluoropolymer according to any one of the preceding claims wherein the curing agent is an ammonia generating compound.

9. The fluoropolymer according to any one of the preceding claims wherein the curing agent is from 0.1 to 7 phr and the heat resistant additive is from 1 to 10 phr of the fluoropolymer composition.

10. The fluoropolymer according to any one of the preceding claims, wherein the fluoropolymer composition is amorphous.

11. A cured fluoropolymer composition formed from by curing the fluoropolymer composition according to any one of the preceding claims.

12. The cured fluoropolymer composition according to claim 11, wherein the cured fluoropolymer composition is an elastomer.

13. The cured fluoropolymer composition according to one of claims 11 or 12, wherein the cured fluoropolymer composition is in the form of a seal.

14. A process, comprising the steps of: curing the composition according to any one of claims 1-10.

15. An article, comprising a cured composition according to any one of claims 11 or 12.

16. The article according to claim 15, wherein the article is in the form of a gasket, seal, tubing, sheet, washer, or O-ring.

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