JP4876580B2 - Fluorine-containing elastomer coating composition - Google Patents

Description

  The present invention relates to a fluorine-containing elastomer coating composition comprising a crosslinkable fluorine-containing elastomer, a crosslinking agent and a solvent. The present invention also relates to a coating film comprising the coating composition and a coated article having the coating film.

  Tetrafluoroethylene (TFE) -perfluorovinyl ether-based perfluoroelastomers are widely used in fields such as the automobile industry, semiconductor industry, and chemical industry because of their outstanding chemical resistance, solvent resistance, and heat resistance. One of its uses is known as a paint.

  A perfluoroelastomer having a high fluorine content cannot be cross-linked by polyol cross-linking or amine cross-linking. Therefore, a coating composition using a peroxide cross-linking agent capable of cross-linking perfluoro rubber has been developed. For example, a coating composition comprising a perfluoro rubber and a peroxide-based crosslinking agent is disclosed as a coating composition (see, for example, JP-A-61-201078 or JP-A-64-75573). ). However, these coating compositions inhibit crosslinking and cannot crosslink under the presence of oxygen. Therefore, crosslinking under conditions that exclude oxygen, such as steam crosslinking in a steam vulcanizer, is necessary. It was. Moreover, there also existed a problem that the heat resistance of a bridge | crosslinking site | part was inferior.

  An imidazole-based crosslinking agent has been disclosed as an effective crosslinking means for perfluoro rubber having excellent heat resistance at the crosslinking site (see, for example, International Publication WO01 / 32773 pamphlet). However, the fluorine-containing elastomer composition containing the imidazole-based cross-linking agent is suitably used as a sealing material and is not known as a paint at present.

  Accordingly, there has been no paint that can be effectively and practically crosslinked using a perfluoroelastomer.

  The present invention provides a fluorine-containing elastomer coating composition excellent in solution stability, comprising a crosslinkable fluorine-containing elastomer, a crosslinking agent and a solvent. Moreover, the coating composition which consists of the said coating composition and was excellent in thermal stability and bridge | crosslinking stability, and the coated article which has the coating film are provided.

  That is, the present invention provides (A) general formula (1):

(Wherein Y ¹ represents —NHR ¹ , —NH ₂ , —OH or —SH, and R ¹ represents a fluorine atom or a monovalent organic group). The present invention relates to a compound containing, (B) a fluorine-containing elastomer having a crosslinking site capable of reacting with the crosslinking reactive group represented by the general formula (1), and (C) a fluorine-containing elastomer coating composition comprising a solvent.

  The fluorine-containing elastomer is preferably a perfluoroelastomer.

  It is preferable that the crosslinking site is composed of at least one group selected from the group consisting of a cyano group, a carboxyl group, and an alkoxycarbonyl group.

  The solvent is preferably a fluorine-based solvent having a hydrogen concentration of 3% or less.

  Moreover, this invention relates to the coating film obtained by bridge | crosslinking the said fluorine-containing elastomer coating composition in the air.

  Furthermore, this invention relates to the coated article which has the coating film which consists of the said coating composition in part or the whole surface of the articles | goods which consist of a metal, resin, rubber | gum, or those composites.

  The present invention relates to (A) general formula (1):

(Wherein Y ¹ represents —NHR ¹ , —NH ₂ , —OH or —SH, and R ¹ represents a fluorine atom or a monovalent organic group). The present invention relates to a compound containing, (B) a fluorine-containing elastomer having a crosslinking site capable of reacting with the crosslinking reactive group represented by the general formula (1), and (C) a fluorine-containing elastomer coating composition comprising a solvent.

<Compound (A)>
Compound (A) has the general formula (1) in order to form a crosslinked structure:

(Wherein Y ¹ represents —NHR ¹ , —NH ₂ , —OH or —SH, and R ¹ represents a fluorine atom or a monovalent organic group, preferably —NHR ¹ ). It has at least 2, preferably 2 to 3, more preferably 2 crosslinkable reactive groups. When the number of crosslinkable reactive groups represented by the general formula (1) is less than 2, crosslinking cannot be performed, so that a coating film cannot be formed.

The substituent R ¹ in the crosslinkable reactive group represented by the general formula (1) is a monovalent organic group other than a hydrogen atom or a fluorine atom. The N—R ¹ bond is preferable because it has higher oxidation resistance than the N—H bond.

Examples of the monovalent organic group include, but are not limited to, an aliphatic hydrocarbon group, a phenyl group, and a benzyl group. Specifically, for example, at least one _-CH 3 of ^{_{R 1, -C 2 H 5,}} -C 3 carbon atoms, such as _{H 7} 1 to 10, especially 1 to 6 lower alkyl group; _-CF 3, - A fluorine-containing lower alkyl group having 1 to 10 carbon atoms, particularly 1 to 6 carbon atoms, such as C ₂ F ₅ , —CH ₂ F, —CH ₂ CF ₃ , —CH ₂ C ₂ F ₅ ; phenyl group; benzyl group; _{C 6 F 5, -CH 2 C} 6 F 5 phenyl or benzyl 1-5 hydrogen atoms with fluorine atoms is substituted, such _{as; -C 6 H 5-n (} CF 3) n, -CH 2 Examples thereof include a phenyl group or a benzyl group in which 1 to 5 hydrogen atoms are substituted with —CF ₃ such as C ₆ H _5-n (CF ₃ ) _n (n is an integer of 1 to 5).

Of these, a phenyl group and —CH ₃ are preferred because they are particularly excellent in heat resistance, have good crosslinking reactivity, and are relatively easy to synthesize.

  As compound (A), general formula (2) having two crosslinkable reactive groups represented by general formula (1):

(Y ¹ is the same as above, R ² is —SO ₂ —, —O—, —CO—, an alkylene group having 1 to 10 carbon atoms,

Or a single bond hand. ) Is preferable from the viewpoint of easy synthesis.

  Preferable specific examples of the alkylene group having 1 to 10 carbon atoms include, for example, an unsubstituted alkylene group having 1 to 6 carbon atoms or a perfluoroalkylene group having 1 to 10 carbon atoms. ,

Etc. These compounds are known as examples of bisdiaminophenyl compounds in JP-B-2-59177 and JP-A-8-120146.

  Among these, more preferable compound (A) is represented by the general formula (3):

(Wherein R ³ are the same or different and both are alkyl groups having 1 to 10 carbon atoms; alkyl groups having 1 to 10 carbon atoms containing fluorine atoms; phenyl groups; benzyl groups; fluorine atoms and / or — A phenyl group or a benzyl group in which 1 to 5 hydrogen atoms are substituted with CF ₃ .

  Specific examples include, but are not limited to, 2,2-bis [3-amino-4- (N-methylamino) phenyl] hexafluoropropane, 2,2-bis [3-amino-4- (N -Ethylamino) phenyl] hexafluoropropane, 2,2-bis [3-amino-4- (N-propylamino) phenyl] hexafluoropropane, 2,2-bis [3-amino-4- (N-phenyl) Amino) phenyl] hexafluoropropane, 2,2-bis [3-amino-4- (N-perfluorophenylamino) phenyl] hexafluoropropane, 2,2-bis [3-amino-4- (N-benzyl) Amino) phenyl] hexafluoropropane and the like. Among these, 2,2-bis [3-amino-4- (N-phenylamino) phenyl] hexafluoropropane is more preferable from the viewpoint of the heat resistance of the crosslinked product.

  The compound (A) described above is excellent in mechanical strength, heat resistance and chemical resistance, and gives a cross-linked product having a good balance between heat resistance and chemical resistance.

  In addition, 2,2-bis- [3-amino-4- (N-phenylamino) phenyl] hexafluoropropane is described in Journal of Polymer Science edited by Polymer Chemistry, Vol. 20, 2381 to 2393 (1982).

  The addition amount of the compound (A) is preferably 0.1 to 20 parts by weight, and more preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the fluorine-containing elastomer (B). When the compound (A) is less than 0.1 parts by weight, there is a tendency that practically sufficient mechanical strength, heat resistance and chemical resistance cannot be obtained. In addition, the cross-linked product tends to be hard and not flexible.

<Fluorine-containing elastomer (B)>
The fluorine-containing elastomer (B) is not particularly limited as long as it has a crosslinking site capable of reacting with the crosslinking reactive group represented by the general formula (1).

As a crosslinking site capable of reacting with the crosslinkable reactive group represented by the general formula (1), a cyano group (—CN group), a carboxyl group (—COOH group), an alkoxycarbonyl group (—COOR ⁴ group, R ⁴ is carbon. Among them, a cyano group is preferable from the viewpoint of the heat resistance of the cross-linked product.

  The fluorine-containing elastomer (B) is not particularly limited as long as it can be crosslinked, but is preferably a perfluoroelastomer from the viewpoint of heat resistance and chemical resistance.

  There is no restriction | limiting in particular as a fluorine-containing elastomer (B), For example, the rubber composition etc. which consist of fluororubber (a), thermoplastic fluororubber (b), and these fluororubbers are mention | raise | lifted.

  Examples of the fluororubber (a) include non-perfluorofluororubber (a-1) and perfluorofluororubber (a-2). Examples of the thermoplastic fluororubber (b) include those comprising an elastomeric fluoropolymer chain segment and a non-elastomeric fluoropolymer chain segment, and an elastomeric fluoropolymer chain segment and a non-elastomeric fluoropolymer chain. Fluorine-containing multi-segmented polymer (b-1) in which 90 mol% or more of each structural unit of the segment is perhaloolefin, and 90 mol% or more of the structural unit of the elastomeric fluoropolymer chain segment is perhaloolefin And a fluorine-containing multi-segmented polymer (b-2) containing a non-elastomeric fluorine-containing polymer chain segment as a constituent unit and containing less than 90 mol% perhaloolefin, and an elastomeric fluorine-containing polymer chain segment as a constituent unit of 90 mol Less than perhaloolefin, and 90 mol% or more of the constituent units of the non-elastomeric fluorine-containing polymer chain segment are perhaloolefins, or the constituent units contain less than 90 mol% perhaloolefins. Polymer (b-3).

  Non-perfluoro fluororubber (a-1) includes vinylidene fluoride (VdF) fluororubber, tetrafluoroethylene (TFE) / propylene fluororubber, tetrafluoroethylene (TFE) / propylene / vinylidene fluoride (VdF). Fluorine rubber, ethylene / hexafluoropropylene (HFP) fluorine rubber, ethylene / hexafluoropropylene (HFP) / vinylidene fluoride (VdF) fluorine rubber, ethylene / hexafluoropropylene (HFP) / tetrafluoroethylene (TFE) -Based fluororubber, fluorosilicone-based fluororubber, fluorophosphazene-based fluororubber, and the like, and these can be used alone or in any combination as long as the effects of the present invention are not impaired.

  The vinylidene fluoride-based fluororubber is a fluorine-containing elastomeric copolymer composed of 45 to 85 mol% of vinylidene fluoride and 55 to 15 mol% of at least one other monomer copolymerizable with vinylidene fluoride. Refers to coalescence. Preferably, it refers to a fluorine-containing elastomeric copolymer comprising 50 to 80 mol% of vinylidene fluoride and 50 to 20 mol% of at least one other monomer copolymerizable with vinylidene fluoride.

  Examples of at least one other monomer copolymerizable with vinylidene fluoride include tetrafluoroethylene (TFE), chlorotrifluoroethylene (CTFE), trifluoroethylene, hexafluoropropylene (HFP), and trifluoropropylene. , Fluorine-containing monomers such as tetrafluoropropylene, pentafluoropropylene, trifluorobutene, tetrafluoroisobutene, perfluoro (alkyl vinyl ether) (PAVE), vinyl fluoride, and non-fluorine monomers such as ethylene, propylene, alkyl vinyl ether The body is raised. These can be used alone or in any combination. Of these, tetrafluoroethylene, hexafluoropropylene, and perfluoro (alkyl vinyl ether) are preferable.

  Specific rubber includes VdF-HFP rubber, VdF-HFP-TFE rubber, VdF-CTFE rubber, VdF-CTFE-TFE rubber, and the like.

  Tetrafluoroethylene / propylene-based fluororubber consists of 45 to 70 mol% tetrafluoroethylene and 55 to 30 mol% propylene, and is a monomer that gives a crosslinking site with respect to the total amount of tetrafluoroethylene and propylene. Fluorine-containing copolymer containing ˜5 mol%.

  Monomers that give a crosslinking site include, for example, cyano group-containing monomers, carboxyl group-containing monomers, and alkoxycarbonyl groups as described in JP-A-4-505345 and JP-A-5-500070. Examples thereof include monomers.

  Examples of the perfluoro fluororubber (a-2) include those made of tetrafluoroethylene / perfluoro (alkyl vinyl ether) / a monomer that gives a crosslinking site. The composition of tetrafluoroethylene / perfluoro (alkyl vinyl ether) is preferably 50 to 90/10 to 50 mol%, more preferably 50 to 80/20 to 50 mol%, still more preferably 55. -70 / 30-45 mol%. The monomer that gives a crosslinking site is preferably 0 to 5 mol%, more preferably 0 to 2 mol%, based on the total amount of tetrafluoroethylene and perfluoro (alkyl vinyl ether). .

  Examples of the perfluoro (alkyl vinyl ether) in this case include perfluoro (methyl vinyl ether) and perfluoro (propyl vinyl ether), and these can be used alone or in any combination.

As a monomer which gives a crosslinking site, for example, general formula (4):
_{CF 2 = CFO (CF 2 CF} (CF 3) O) m (CF 2) n -X 1 (4)
(Wherein, m is an integer of 0 to 5, n is an integer of ^{1 to} 3, and X ¹ is a cyano group, a carboxyl group, or an alkoxycarbonyl group). Each can be used alone or in any combination.

  This cyano group, carboxyl group, and alkoxycarbonyl group serve as a crosslinking site, and the crosslinking reaction proceeds with the compound (A).

  Next, the fluorine-containing multi-segmented polymer (b-1) which is the thermoplastic fluororubber (b) will be described.

First, the elastomeric fluorine-containing polymer chain segment will be described. The elastomeric fluorine-containing polymer chain segment imparts flexibility to the polymer and has a glass transition point of 25 ° C. or lower, preferably 0 ° C. or lower. Examples of the perhaloolefin constituting 90 mol% or more of the structural unit include tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, and general formula (5):
^{_{CF 2 = CFO (CF 2 CFY}} 2 O) p - (CF 2 CF 2 CF 2 O) q -R f 1 (5)
(Wherein Y ² is F or CF ₃ , R _f ¹ is a C 1-5 perfluoroalkyl group, p is an integer of 0-5, q is an integer of 0-5) Perfluorovinyl ether.

  Examples of structural units other than perhaloolefins constituting the elastomeric fluorine-containing polymer chain segment include vinylidene fluoride, trifluoroethylene, trifluoropropylene, tetrafluoropropylene, pentafluoropropylene, trifluorobutene, tetrafluoroisobutene, and fluorine. Any fluorine-containing monomer such as vinyl fluoride, non-fluorine monomer such as ethylene, propylene, and alkyl vinyl ether may be used.

  Preferable examples of the elastomeric fluorine-containing polymer chain segment include an elastomeric polymer chain composed of tetrafluoroethylene / perfluoro (alkyl vinyl ether) / a monomer that provides a crosslinking site. The composition of tetrafluoroethylene / perfluoro (alkyl vinyl ether) is 50 to 85/50 to 15 mol%, and the monomer giving the crosslinking site is based on the total amount of tetrafluoroethylene and perfluoro (alkyl vinyl ether). The content is preferably 0 to 5 mol%.

  Examples of the monomer that gives a crosslinking site include monomers represented by general formula (4) and general formula (5).

Next, the non-elastomeric fluorine-containing polymer chain segment will be described. Examples of the perhaloolefin constituting 90 mol% or more of the structural unit of the non-elastomeric fluorine-containing polymer chain segment include tetrafluoroethylene, chlorotrifluoroethylene, perfluoro (alkyl vinyl ether), hexafluoropropylene, and general formula (6 ):
CF ₂ = CF (CF ₂ ) _r X ² (6)
(Wherein, r represents an integer of 1 to 10, X ² represents a fluorine atom or a chlorine atom), and perhaloolefins such as perfluoro-2-butene.

  Examples of the structural unit other than the perhaloolefin constituting the non-elastomeric fluoropolymer chain segment include the same structural units as those other than the perhaloolefin constituting the elastomeric fluoropolymer chain segment.

Preferable examples of the non-elastomeric fluorine-containing polymer chain segment include 85 to 100 mol% of tetrafluoroethylene and the general formula (7):
^{_{CF 2 = CF-R f 2}} (7)
(Wherein R _f ² is R _f ³ or —OR _f ³ , and R _f ³ is a perfluoroalkyl group having 1 to 5 carbon atoms) A functional polymer chain.

  Next, the fluorine-containing multi-segmented polymer (b-2) will be described.

  The elastomeric fluorine-containing polymer chain segment in this case may be the same as described for the fluorine-containing multi-segmented polymer (b-1).

As the structural unit of the non-elastomeric fluorine-containing polymer chain segment, vinylidene fluoride, vinyl fluoride, trifluoroethylene, general formula (8):
^{_{CH 2 = CX 3 - (CF}} 2) s -X 3 (8)
(Wherein, X ³ is a hydrogen atom or a fluorine atom, s is an integer of 1 to 10), partially fluorinated olefins such as CH ₂ ═C (CF ₃ ) ₂ and the like.

  In addition, monomers such as ethylene, propylene, vinyl chloride, vinyl ether, carboxylic acid vinyl ester, and acrylic acid that can be copolymerized with these monomers can also be used as a copolymerization component.

  Next, the fluorine-containing multi-segmented polymer (b-3) will be described.

  The elastomeric fluorine-containing polymer chain segment in the fluorine-containing multi-segmented polymer (b-3) is a polymer chain having a glass transition point of 25 ° C. or lower, preferably 0 ° C. or lower.

  The elastomeric fluorine-containing polymer chain segment contains less than 90 mol% perhaloolefin as a structural unit. Examples of the structural unit other than the perhaloolefin in this case include the same structural units as those other than the perhaloolefin of the fluorine-containing multi-segmented polymer (b-1).

  The non-elastomeric fluorine-containing polymer chain segment in the fluorine-containing multi-segment polymer (b-3) is the non-elastomeric fluorine-containing polymer chain segment in the fluorine-containing multi-segment polymer (b-1) or (b-2) described above. Same as

  It is important that the thermoplastic fluororubber (b) is a fluorine-containing multi-segment polymer in which an elastomeric fluorine-containing polymer chain segment and a non-elastomeric fluorine-containing polymer chain segment are bonded in the form of a block or graft in one molecule. is there.

  The number average molecular weight of the elastomeric fluorine-containing polymer chain segment is 5,000 to 750,000 from the viewpoints of imparting flexibility, elasticity, and mechanical properties to the whole fluorine-containing multi-segmented polymer. It is preferable that it is 20,000-400,000.

  The number average molecular weight of the non-elastomeric segment is preferably 1,000 to 1,200,000, more preferably 3,000 to 600,000.

  Further, from the viewpoint of heat resistance of the thermoplastic perfluoro rubber (b) (fluorinated multi-segmented polymer), the crystal melting point of the non-elastomeric fluoropolymer chain segment is preferably 150 ° C. or higher, and 200 to 360. More preferably, it is ° C.

  It is important that the thermoplastic perfluoro rubber (b) is a fluorine-containing multi-segmented polymer in which an elastomeric fluorine-containing polymer chain segment and a non-elastomeric fluorine-containing polymer chain segment are bonded in the form of a block or graft in one molecule. A polymer molecule in which a non-elastomeric fluoropolymer chain segment is bonded to both sides of an elastomeric fluoropolymer chain segment, and a polymer molecule in which a non-elastomeric fluoropolymer chain segment is bonded to one side of an elastomeric fluoropolymer chain segment It is based on.

  In the present invention, a composition comprising the fluororubber (a) and the thermoplastic fluororubber (b) as described above can also be used.

<Method for producing fluorine-containing elastomer (B)>
The fluorine-containing elastomer (B) used in the present invention can be produced by a conventional method, and can be produced by a polymerization method such as an emulsion polymerization method, a suspension polymerization method, or a solution polymerization method. What is necessary is just to determine suitably polymerization conditions, such as temperature at the time of superposition | polymerization, time, etc. with the kind of monomer, and the target elastomer.

The polymerization initiator is preferably a carboxyl group or a group capable of forming a carboxyl group (for example, acid fluoride, acid chloride, —CF ₂ OH, etc., all of which generate a carboxyl group in the presence of water). Are preferably present at the end of the elastomer. Specific examples include ammonium persulfate (APS) and potassium persulfate (KPS).

  As a method for isolating the polymerization product from the polymerization reaction mixture, a method of coagulating by acid treatment is preferable from the viewpoint of simplification of the process. Alternatively, the polymerization mixture may be acid-treated, and then the polymerization product may be isolated by means such as lyophilization. Furthermore, methods such as coagulation by ultrasonic waves and coagulation by mechanical force can be employed.

  The fluorine-containing elastomer (B) used in the present invention can convert a group such as a metal salt or ammonium salt of a carboxylic acid present in the polymerization product into a carboxyl group by treating the polymerization product with an acid. . As the acid treatment method, for example, washing with hydrochloric acid, sulfuric acid, nitric acid or the like, or a method of bringing the mixture system after polymerization reaction with these acids to pH 3 or less is suitable.

  Moreover, a crosslinkable elastomer containing iodine or bromine can be oxidized with fuming nitric acid to introduce a carboxyl group.

  Furthermore, as a method for introducing a cyano group, a carboxyl group, or an alkoxycarbonyl group, the method described in International Publication No. 00/05959 pamphlet can also be used.

<Solvent (C)>
The solvent that can be used in the present invention is not particularly limited as long as it can sufficiently dissolve the fluorine-containing elastomer. Further, when a perfluoroelastomer is used as the fluorine-containing elastomer, a fluorine-based solvent having a hydrogen concentration calculated from a chemical structure of 3% or less is preferable in that the perfluoroelastomer can be sufficiently dissolved. A completely fluorinated solvent in which is 0% is more preferred. If the solvent has a hydrogen concentration exceeding 3%, the perfluoroelastomer tends to have poor solubility.

  Furthermore, the phenylamine skeleton in the compound (A) tends to be deteriorated with some lower ketone solvents and the like, and it is preferable to use a solvent that does not deteriorate because it impairs long-term solution stability.

Examples of fluorine-based solvents that do not alter the phenylamine skeleton include perfluoro tertiary amines (for example, perfluorotri-n-butylamine, perfluorotriethylamine), CFC (fully halogenated chlorofluorocarbon), HFC (hydrofluorocarbon), HCFC ( Hydrochlorofluorocarbon), Fluorinert FC-77 (registered trademark, manufactured by Sumitomo 3M Limited, main component: C ₈ F ₁₆ O), and the like. Solvents other than fluorine-based solvents include ketones such as methyl isobutyl ketone and isophorone, esters such as butyl acetate and isopentyl acetate, ethers such as diethylene glycol dimethyl ether, hydrocarbons such as toluene and xylene, N and N -Amides such as dimethylacetamide and N-methyl-2-pyrrolidone. These can be used alone or in combination of two or more kinds of solvents.

  Moreover, it is preferable to use 40 to 95 weight% of solvent (C) based on the weight of the whole coating composition, and it is more preferable to use 70 to 90 weight%. If the solvent is less than 40% by weight, the solution viscosity of the composition tends to be high and processing tends to be difficult, and if it exceeds 95% by weight, the film thickness obtained by one application tends to be very thin.

<Fluorine-containing elastomer coating composition>
The coating composition of the present invention is prepared by mixing each component other than the solvent with a normal rubber processing machine such as an open roll, a Banbury mixer, a kneader, etc. to make a compound, and then dissolving or dispersing in the solvent. Can be prepared. In addition, it can also prepare by the method of mixing each component using closed mixers, such as a ball mill.

  Also, if necessary, various additives such as fillers, processing aids, plasticizers, colorants, stabilizers, adhesion aids, etc., can be blended into the crosslinkable elastomer composition. One or more conventional crosslinking agents or crosslinking accelerators different from those described above may be blended.

  Examples of fillers include inorganic fillers such as carbon black and metal oxides, and organic fillers such as engineering resin powders. Specific examples of metal oxides include aluminum oxide and magnesium oxide. Examples of the filler include imide fillers having an imide structure such as polyimide, polyamideimide, and polyetherimide; polyarylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyoxybenzoate, and the like.

  Examples of the substance base material (coated material) to be coated with the coating composition of the present invention include metals such as iron, stainless steel, copper, aluminum and brass; glass products such as glass plates, woven fabrics and nonwoven fabrics of glass fibers; Molded and coated products of general-purpose and heat-resistant resins such as polypropylene, polyoxymethylene, polyimide, polyamideimide, polysulfone, polyethersulfone, polyetheretherketone; general-purpose rubbers such as SBR, butyl rubber, NBR, EPDM, and silicone Molded articles and coatings of heat-resistant rubbers such as rubber and fluororubber; woven fabrics and non-woven fabrics of natural fibers and synthetic fibers can be used, but the composition of the present invention is particularly molded of imide resins and fluororubbers. Excellent adhesion to products.

  As a coating method of the obtained coating composition, for example, dip coating, casting, spray coating, brush coating, curtain flow coating and the like can be performed. Examples of the base material that can be applied include metals, resins, rubbers, and composites thereof.

  The applied coating film is preferably subjected to evaporation of the solvent after application and further crosslinking of the coating composition. The method for evaporating the solvent is not particularly limited as long as it is a commonly used method such as air drying or oven drying.

  The crosslinking conditions may be appropriately determined depending on the type of the crosslinking agent to be used. Usually, firing is performed at a temperature of 150 to 300 ° C. for 1 minute to 24 hours.

  In addition, as a crosslinking method, a crosslinking reaction is performed under any conditions, not only in a method commonly used such as steam crosslinking, but also under normal pressure, increased pressure, reduced pressure, and in air. be able to.

  In the conventional peroxide cross-linking, since cross-linking inhibition occurs under the condition where oxygen is present, steam cross-linking in a steam vulcanizing can or cross-linking in an inert gas, etc. required large facilities for cross-linking. Since the coating composition of the present invention can be crosslinked in the air, in addition to being able to easily obtain a coating film, the obtained coating film is excellent in thermal stability and chemical resistance. Yes.

  The film formed from the coating composition of the present invention is suitable for a metal gasket because it is excellent in chemical resistance and has improved surface stickiness during high-temperature and long-term compression. In addition, by forming a film on the other base material, it can be used in fields requiring heat resistance, solvent resistance, lubricity, and adhesion, and specific applications include the following fields. It can be used suitably.

  In semiconductor-related fields such as semiconductor manufacturing equipment, liquid crystal panel manufacturing equipment, plasma panel manufacturing equipment, plasma addressed liquid crystal panels, field emission display panels, solar cell substrates, etc., O (square) rings, packing, sealing materials, tubes, rolls, coatings Linings, gaskets, diaphragms, hoses, etc. These include CVD equipment, dry etching equipment, wet etching equipment, oxidation diffusion equipment, sputtering equipment, ashing equipment, cleaning equipment, ion implantation equipment, exhaust equipment, chemical piping, gas Can be used for piping. Specifically, as a gate valve O-ring, seal material, quartz window O-ring, seal material, chamber O-ring, seal material, gate O-ring, seal material, bell jar O-ring, seal material As an O-ring for a coupling, as a sealing material, as an O-ring for a pump, as a sealing material, as a diaphragm, as an O-ring for a semiconductor gas control device, as a sealing material, as an O-ring for a resist developer, as a stripping solution, as a sealing material As a wafer cleaning solution hose and tube, as a wafer transfer roll, as a resist developer bath, a stripping solution bath lining, as a coating, as a wafer cleaning bath lining, as a coating or as a wet etching bath lining, as a coating Can do. In addition, sealing materials and sealants, optical fiber quartz coatings, electronic parts for insulation, vibration proofing, waterproofing and moisture proofing, circuit board potting, coating, adhesive sealing, gaskets for magnetic storage devices, epoxies, etc. Used as a sealing material modifier, sealant for clean rooms and clean facilities, etc.

  In the automotive field, gaskets, shaft seals, valve stem seals, sealing materials and hoses can be used for engines and peripheral devices, hoses and sealing materials can be used for AT devices, O (square) rings, tubes, packings. The valve core material, hose, sealing material and diaphragm can be used for fuel systems and peripheral devices. Specifically, engine head gasket, metal gasket, oil pan gasket, crankshaft seal, camshaft seal, valve stem seal, manifold packing, oil hose, oxygen sensor seal, ATF hose, injector O-ring, injector packing, fuel Pump O-ring, diaphragm, fuel hose, crankshaft seal, gear box seal, power piston seal, cylinder liner seal, valve stem seal, automatic transmission front pump seal, rear axle pinion seal, universal joint gasket, speed Meter pinion seal, foot brake piston cup, torque transmission O-ring, oil seal, exhaust gas reburner seal, bearing Lumpur, EGR tubes, Tsuinkyabu tube, the sensor diaphragm of the carburetor, rubber vibration isolator (engine mount, exhaust part, etc.), afterburners hoses, can be used as an oxygen sensor bush.

  In the aircraft field, the rocket field, and the marine field, there are diaphragms, O (square) rings, valves, tubes, packings, hoses, sealing materials, and the like, which can be used for fuel systems. Specifically, in the aircraft field, it is used for jet engine valve stem seals, fuel supply hoses, gaskets and O-rings, rotating shaft seals, hydraulic equipment gaskets, firewall seals, etc. Used for propeller shaft stern seal, diesel engine intake / exhaust valve stem seal, butterfly valve seal, butterfly valve shaft seal, etc.

  In the field of chemical products such as plants, linings, valves, packing, rolls, hoses, diaphragms, O (square) rings, tubes, sealing materials, chemical-resistant coatings, etc., these are pharmaceuticals, agricultural chemicals, paints, resins, etc. It can be used in chemical manufacturing processes. Specifically, chemical pumps, rheometers, pipe seals, heat exchanger seals, glass cooler packing for sulfuric acid production equipment, pesticide sprayers, pesticide transfer pump seals, gas pipe seals, plating solutions Seals, packing for high-temperature vacuum dryers, roller seals for papermaking belts, fuel cell seals, wind tunnel joint seals, rolls for trichrene (for fiber dyeing), acid-resistant hoses (for concentrated sulfuric acid), gas chromatography, pH meter It can be used as packing for tube joints, chlorine gas transfer hoses, benzene, rainwater drain hoses for toluene storage tanks, seals for analytical instruments, physics and chemistry instruments, tubes, diaphragms, valve parts, and the like.

  In the pharmaceutical field such as pharmaceuticals, it can be used as a medicine stopper.

  In the photographic field such as a developing machine, the printing field such as a printing machine, and the coating field such as a coating facility, there are rolls and the like, which can be used for a film developing machine, an X-ray film developing machine, a printing roll, and a coating roll, respectively. Specifically, as a developing roll of a film developing machine / X-ray film developing machine, a gravure roll of a printing roll, a guide roll, a gravure roll of a magnetic tape manufacturing coating line of a coating roll, a guide roll of a magnetic tape manufacturing coating line, It can be used as various coating rolls. Furthermore, dry copying machine seals, printing equipment printing rolls, scrapers, tubes, valve parts, coating, coating equipment coating rolls, scrapers, tubes, valve parts, printer ink tubes, rolls, belts, dry copying machine belts , Rolls, printing press rolls, belts, and the like.

  Tubes can also be used in the field of analysis and physics and chemistry.

  In the field of food plant equipment, linings, valves, packings, rolls, hoses, diaphragms, O (square) rings, tubes, sealing materials, belts and the like can be mentioned and used in food production processes. Specifically, it can be used as a seal for a plate heat exchanger, a solenoid valve seal for a vending machine, or the like.

  In the field of nuclear plant equipment, packing, O-rings, hoses, sealing materials, diaphragms, valves, rolls, tubes and the like can be mentioned.

  In the steel field such as iron plate processing equipment, rolls and the like can be mentioned, and they can be used for iron plate processing rolls and the like.

  In general industrial fields, packing, O-rings, hoses, sealing materials, diaphragms, valves, rolls, tubes, linings, mandrels, electric wires, flexible joints, belts, rubber plates, weather strips, rolls for PPC copiers, roll blades, belts Etc. Specifically, hydraulic, lubrication machinery seals, bearing seals, dry cleaning equipment windows, other seals, uranium hexafluoride concentrator seals, cyclotron seals (vacuum) valves, automatic packaging machine seals, air It is used for diaphragms (pollution measuring devices) for analysis of sulfurous acid gas and chlorine gas in the inside, rolls for printing presses, belts, pickling rolls for pickling.

  In the electric field, specifically, it is used as an insulating oil cap for Shinkansen, a bench seal for a liquid seal transformer, a jacket for an oil well cable, and the like.

  In the fuel cell field, specifically, it is used as a sealing material between electrodes and separators, a seal for hydrogen / oxygen / product water piping, and the like.

  Specifically, in the field of electronic components, it is used as a heat radiation material, an electromagnetic shielding material, a modified material of a printed wiring board prepreg resin such as epoxy, an anti-scattering material such as a light bulb, and a gasket of a hard disk drive of a computer.

  There are no particular limitations on what can be used for on-site molding, such as metal gasket coatings for automobile engines, engine oil pan gaskets, copier / printer rolls, architectural sealants, Gaskets for magnetic recording devices, sealants for filter units for clean rooms, coating agents for printed boards, fixing agents for electrical and electronic components, insulation and moisture-proof treatment of electrical equipment lead wire terminals, oven seals for electric furnaces, sheathed heaters Examples include end treatment, microwave window frame seals, adhesion of CRT wedges and necks, adhesion of automotive electrical components, joint seals for kitchens, bathrooms, washrooms, and the like.

  Next, the present invention will be described with reference to examples, but the present invention is not limited to such examples.

Production Example 1 (Synthesis of cyano group-containing elastomer)
In an autoclave made of stainless steel with an internal volume of 3 mL that has no ignition source, 1 L of pure water and emulsifier

10 g, charged with 0.09 g of disodium hydrogen phosphate and 12 hydrate as a pH adjuster, thoroughly purged the system with nitrogen gas, degassed, heated to 50 ° C. while stirring at 600 rpm, A mixed gas (TFE / PMVE = 25/75 molar ratio) of fluoroethylene (TFE) and perfluoro (methyl vinyl ether) (PMVE) was charged so that the internal pressure was 0.78 MPa · G. Next, 10 mL of an aqueous solution of ammonium persulfate (APS) having a concentration of 527 mg / mL was injected under nitrogen pressure to initiate the reaction.

When the internal pressure decreased to 0.69 MPa · G due to the progress of the polymerization, 3 g of CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CN (CNVE) was injected under nitrogen pressure. Next, 4.7 g of TFE and 5.3 g of PMVE were respectively injected under their own pressure so that the pressure became 0.78 MPa · G. Thereafter, as the reaction proceeds, TFE and PMVE are similarly injected, and the pressure is increased and decreased repeatedly between 0.69 and 0.78 MPa · G, and the total amount of TFE and PMVE is 70 g, 130 g, 190 g, and 250 g. At that time, 3 g of CNVE was injected under nitrogen pressure.

  19 hours after the start of the polymerization reaction, when the total amount of TFE and PMVE reached 300 g, the autoclave was cooled to release unreacted monomers, and 1330 g of an aqueous dispersion having a solid content concentration of 21.2% by weight. Got.

  1196 g of this aqueous dispersion was diluted with 3588 g of water and slowly added to 2800 g of 3.5 wt% aqueous hydrochloric acid with stirring. After stirring for 5 minutes after the addition, the coagulated product was filtered off, and the obtained polymer was further poured into 2 kg of HCFC-141b, stirred for 5 minutes, and filtered again. Thereafter, washing with HCFC-141b and filtration were repeated four more times, followed by vacuum drying at 60 ° C. for 72 hours to obtain 240 g of a cyano group-containing elastomer.

As a result of ¹⁹ F-NMR analysis, the monomer unit composition of this polymer was TFE / PMVE / CNVE = 56.6 / 42.3 / 1.1 mol%.

Production Example 2 (Synthesis of iodine-containing elastomer)
As an electromagnetic stirring glass autoclave with an internal volume of 1 L, 500 ml of pure water and an emulsifier

50 g and 1.634 g NaCl were charged and dissolved, followed by 0.880 g Na ₂ SO ₃ . After degassing the autoclave and replacing the internal space with nitrogen gas, 150 g of C ₃ F ₇ O [(CF ₂ ) ₃ O] ₂ CF = CF ₂ was charged, degassed again with an autoclave, and then internalized with tetrafluoroethylene After replacing the space, tetrafluoroethylene was injected at 15 ° C. and pressurized to 2.04 kg / cm ² G, and then pressurized to 3.0 kg / cm ² G with hexafluoropropylene. At this time, the gas composition in the space of the autoclave was about 35 mol% hexafluoropropylene.

While stirring the contents of the autoclave at 720 rpm, a solution of 5 mg of ammonium persulfate (APS) in 5 mL of pure water was press-fitted with tetrafluoroethylene gas. When the polymerization was started and the pressure dropped to 2.8 kg / cm ² G, 1.0 g of I (CF ₂ ) ₄ I was injected with tetrafluoroethylene gas and charged. Thereafter, when the pressure decreased to 2.0 kg / cm ² G, tetrafluoroethylene was injected to recover the pressure to 3.0 kg / cm ² G. While maintaining the temperature at 15 ° C., the pressure was repeatedly lowered and recovered, and polymerization was carried out for 9 hours. Thereafter, 100 mg of a hydroquinone pure solution was injected with tetrafluoroethylene gas to terminate the polymerization. After releasing the gas in the autoclave, 780.7 g of a transparent dispersion was recovered. To this dispersion, 430 g of pure water and 450 mL of acetone and 150 mL of hydrochloric acid are added and stirred to coagulate the product. The coagulated product is washed twice with acetone and then dried under reduced pressure at 100 ° C. 145.9 g of polymer was obtained.

Example 1
Fluorine-containing elastomer containing cyano group obtained in Production Example 1 and Journal of Polymer Science, Polymer Chemistry, Vol. 20, 2, 2381-2393 (1982), 2,2-bis [3-amino-4- (N-phenylamino) phenyl] hexafluoropropane (AFTA-Ph), which is a crosslinking agent synthesized by the method described in carbon Black (Thermax N-990, manufactured by Cancarb) was mixed with an open roll at a weight ratio of 100 / 0.8 / 20 (parts by weight), and then Fluorinert FC-77 (registered trademark, Sumitomo 3M Co., Ltd.), a perflo solvent, was mixed. A coating composition having a solid content concentration of 10% by weight was prepared by dissolving in a main component: C ₈ F ₁₆ O).

  Next, the coating composition was applied on a SUS304 plate using a bar coater, air-dried for 30 minutes, and then dried in an oven set at 80 to 100 ° C. for 30 minutes to form a coating film having a thickness of about 10 μm. did. Further, baking was then performed at 200 ° C. for 10 minutes.

  Table 1 shows the results of the following evaluations on the obtained coated plate.

(Surface condition)
The obtained coating film was immersed in Fluorinert FC-77 (registered trademark, manufactured by Sumitomo 3M Co., Ltd., main component: C ₈ F ₁₆ O) at 40 ° C. for 24 hours, and the surface state was visually observed. evaluated.
○: Not dissolved.
(Triangle | delta): The surface part of the coating film melt | dissolved.
X: The coating film was almost completely dissolved.

(State of liquid after immersion)
Visual observation of the state of the liquid (color, dustiness) after immersing the resulting coating film in Fluorinert FC-77 (registered trademark, manufactured by Sumitomo 3M Limited, main component: C ₈ F ₁₆ O) at 40 ° C. for 24 hours And evaluated according to the following criteria.
○: colorless and transparent, no change (dissolved coating film, no loss of carbon black)
(Triangle | delta): There existed a black floating thing (the fall of carbon black by dissolution of a coating film was little).
X: The liquid turned black (the carbon black was frequently dropped due to dissolution of the coating film).

Comparative Example 1
Fluorine-containing elastomer containing iodine at the terminal obtained in Production Example 2, perhexa 25B (manufactured by Nippon Oil & Fats Co., Ltd.), triallyl isocyanurate (TAIC) (manufactured by Nippon Kasei Co., Ltd.), and carbon black (Cancarb) Thermax N-990) was mixed with an open roll at a weight ratio of 100/1/3/20 (parts by weight), and then fluorinate FC-77 (registered trademark, manufactured by Sumitomo 3M Limited), which is a perflo solvent, A coated plate was obtained in the same manner as in Example 1 except that the composition was dissolved in component (C ₈ F ₁₆ O) and a coating composition having a solid content concentration of 10% by weight was prepared.

  Table 1 shows the results of evaluating the surface state of the coating film and the state of the liquid after immersion for the resulting coated plate.

Comparative Example 2
Instead of firing at 200 ° C. for 10 minutes, a coated plate was obtained in the same manner as in Comparative Example 1, except that heating was performed at 150 ° C. for 60 minutes in a steam vulcanizing can.

  Table 1 shows the results of evaluating the surface state of the coating film and the state of the liquid after immersion with respect to the obtained coated plate.

  The coating films obtained in Comparative Examples 1 and 2 in Table 1 were immersed in Fluorinert FC-77, so that the coating film dissolved and the carbon black contained in the coating composition dropped off. It can be seen that the cross-linking reaction does not proceed sufficiently due to the blackening of. On the other hand, since the coating film obtained in Example 1 has neither dissolution of the coating film nor turbidity of the liquid, it can be seen that the crosslinking reaction proceeds sufficiently in the air.

Comparative Example 3
Fluorine-containing elastomer containing a polyol-based crosslinking agent (Daiel G-701, manufactured by Daikin Industries, Ltd.), magnesium oxide (MA-150, manufactured by Kyowa Chemical Industry Co., Ltd.), calcium hydroxide (CALDIC # 2000, Omi Chemical Industries, Ltd.) And carbon black (N990, manufactured by Cancarb LTD.) At a weight ratio of 100/3/6/20 (parts by weight) with an open roll to obtain a crosslinkable fluororubber composition.

  The obtained fluororubber composition was subjected to press crosslinking at 170 ° C. for 10 minutes, and then oven-crosslinked in an air oven at 230 ° C. for 24 hours to obtain a 20 mm × 30 mm fluororubber sheet having a thickness of 2 mm. Obtained.

  Table 2 shows the results of immersing the obtained fluororubber sheet in acetone at 40 ° C. for 5 hours and measuring the volume increase rate before and after immersion.

Example 2
The coating composition prepared in Example 1 was applied to the surface of the fluororubber sheet obtained in Comparative Example 3 with a brush, air-dried for 30 minutes, and then dried in an oven set at 80 to 100 ° C. for 30 minutes. Thereafter, baking was performed at 200 ° C. for 10 minutes. This operation was repeated three times, and further, baking was performed at 230 ° C. for 5 hours to obtain a fluororubber sheet whose surface was completely covered with a coating film.

  Table 2 shows the results of immersing the obtained fluororubber sheet in acetone at 40 ° C. for 5 hours and measuring the volume increase rate before and after immersion.

  The fluorine-containing elastomer coating composition of the present invention comprises a crosslinkable fluorine-containing elastomer, a crosslinking agent and a solvent, and thus has excellent solution stability, and further, a coating film excellent in thermal stability and crosslinking stability, And the coated article which has the coating film can be provided.

Claims (3)

(A) General formula (1):

(In the formula, Y ¹ is —NHR ¹ , —NH ₂ , —OH or —SH, and R ¹ contains a fluorine atom, a lower alkyl group having 1 to 6 carbon atoms, and a fluorine atom having 1 to 6 carbon atoms. A lower alkyl group, a phenyl group, a benzyl group, a phenyl group or a benzyl group in which 1 to 5 hydrogen atoms are substituted with a fluorine atom, or a phenyl group in which 1 to 5 hydrogen atoms are substituted with -CF ₃ or A compound containing at least two crosslinkable reactive groups represented by benzyl group),
(B) a perfluoroelastomer having a crosslinking site comprising at least one group selected from the group consisting of a cyano group, a carboxyl group and an alkoxycarbonyl group, and (C) a fluorine- containing elastomer comprising a fully fluorinated solvent. Paint composition. A coating film obtained by crosslinking the fluorine-containing elastomer coating composition according to claim 1 in air. A coated article having a coating film made of the coating composition according to claim 1 on a part or the whole surface of an article made of metal, resin, rubber or a composite thereof.