JP4353514B2 - Article containing fluororubber composition and cured product thereof - Google Patents

Description

  The present invention relates to a curable fluoropolyether rubber composition and a rubber that are excellent in solvent resistance, chemical resistance, weather resistance, heat resistance, water repellency, oil repellency, and can obtain a cured rubber having good low-temperature characteristics. Regarding products.

  A linear fluoropolyether compound having two vinyl groups in one molecule and a perfluoropolyether structure in the main chain, having one or more fluorine-containing groups in one molecule, and 2 Properties such as heat resistance, chemical resistance, solvent resistance, low temperature characteristics, moisture permeability, etc. from a composition comprising a fluorine-containing organohydrogensiloxane having at least one hydrosilyl group and a catalytic amount of a platinum group compound (hydrosilylation reaction catalyst) Japanese Patent No. 2990646 proposes that an excellent cured product with a good balance can be obtained.

  In Japanese Patent Application No. 2002-001257, a composition comprising a fluoropolyether compound having a perfluoropolyether structure in the main chain, a reinforcing filler, and a peroxide crosslinking agent is used. It has been shown that a cured product having a good balance of properties at low temperatures can be obtained.

  These fluoropolyether rubber compositions do not lose flexibility even at −50 ° C. or lower, and exhibit excellent low-temperature characteristics that do not cause embrittlement even in a long-time low-temperature environment that is a problem with fluorinated olefin elastomers.

  In the case of such a fluoropolyether rubber composition, in order to obtain a cured product having physical properties according to the purpose of use, fumed silica, quartz powder, glass fiber, carbon and titanium oxide and other metal oxides, calcium carbonate, An inorganic filler such as a metal carbonate such as magnesium carbonate is added.

However, in the presence of the hydrofluoric acid component, as the blending amount of these inorganic fillers increases, fluorine ions easily penetrate into the cured product of the fluororubber composition and the hydrofluoric acid resistance decreases. There is.

  On the other hand, fluorinated olefin elastomers represented by copolymers of vinylidene fluoride and hexafluoropropylene or tetrafluoroethylene have excellent heat resistance, chemical resistance and solvent resistance, and relatively good hydrofluoric acid resistance. It is a material and is widely used for seals, gaskets, hoses, O-rings and the like.

  However, it is also widely known that these fluorinated olefin elastomers generally exhibit rigidity at low temperatures and do not exhibit rubber performance. For example, the glass transition temperature of a copolymer of vinylidene fluoride and hexafluoropropylene is slightly lower than 0 ° C., and it easily becomes brittle at a lower temperature or a long-time low temperature environment. For this reason, there is a major drawback that it cannot be used under conditions exposed to low temperatures.

Japanese Patent No. 2990646 Japanese Patent Application No. 2002-001257

  The present invention has been made to meet the above demands, and has excellent properties such as heat resistance, chemical resistance, solvent resistance, moisture permeability and the like, as well as a cured product excellent in low temperature properties and hydrofluoric acid resistance. An object of the present invention is to provide a curable fluoropolyether rubber composition.

  As a result of intensive studies to achieve the above object, the present inventors have (A) a polymer compound represented by the following general formula (1) having a viscosity at 25 ° C. of 1,000 Pa · s or higher,

（但し、ｎは１以上の整数、Ｒｆは二価のパーフルオロアルキレン基又はパーフルオロオキシアルキレン基、Ｑは二価の有機基、Ｚは一価の有機基を示す。）
（Ｂ）平均粒径０．００１〜２００μｍの含フッ素エラストマー硬化物粒子、（Ｃ）パーオキサイド架橋剤から、耐熱性、耐薬品性、耐溶剤性、低温特性、透湿性等の諸特性に優れている上、低温特性、耐フッ酸性に優れつ硬化物を与える硬化性フルオロポリエーテルゴム組成物が得られることを見出し、本発明をなすに至った。

(However, n represents an integer of 1 or more, Rf represents a divalent perfluoroalkylene group or perfluorooxyalkylene group, Q represents a divalent organic group, and Z represents a monovalent organic group.)
(B) Fluorine-containing elastomer cured particles having an average particle size of 0.001 to 200 μm, (C) Excellent properties such as heat resistance, chemical resistance, solvent resistance, low temperature characteristics, moisture permeability, etc. In addition, the inventors have found that a curable fluoropolyether rubber composition having excellent low-temperature characteristics and hydrofluoric acid resistance and giving a cured product can be obtained, and the present invention has been made.

That is, the present invention relates to a curable fluororubber composition comprising the component (A), the component (B), and the component (C), and a fluororubber cured product obtained by curing the composition. As an article to have.

Hereinafter, the present invention will be described in more detail.
Component (A) The component (A) has a viscosity at 25 ° C. of 1,000 Pa · s or more, preferably 2,000 to 100,000 Pa · s, more preferably 2,000 to 10,000 Pa · s. It is a polymer compound represented by (1).

（但し、ｎは１以上の整数、Ｒｆは二価のパーフルオロアルキレン基又はパーフルオロオキシアルキレン基、Ｑは下記式（５）で表わされる基であり、Ｚは一価の有機基を示す。）

(Where n is an integer of 1 or more, Rf is a divalent perfluoroalkylene group or perfluorooxyalkylene group, Q is a group represented by the following formula (5), and Z represents a monovalent organic group. )

In this case, n is a number that gives the viscosity. In this case, the component (A) is usually in the form of a raw rubber, and the kinematic viscosity of the solution when dissolved in nonafluorobutyl methyl ether at a concentration of 10% by mass is 2.0 mm ² / s or more, more preferably It is preferable that it is 5-50 mm < ² > / s, especially 10-40 mm < ² > / s.

Rf is independently selected from a divalent perfluoroalkylene group represented by C _m F _2m (m = 2 to 15) or a group represented by the following formulas (2), (3), and (4). A valent perfluorooxyalkylene group is preferred.

（Ｘはそれぞれ独立にＦ又はＣＦ_３基、ｒは２〜６の整数、ｔ、ｕはそれぞれ１又は２、ｐ、ｑはそれぞれ０〜２００の整数、ｓは０〜６の整数であるが、ｐ、ｑ、ｓが同時に０とはならない。）

(X is independently F or CF ₃ group, r is an integer of 2 to 6, t and u are each 1 or 2, p and q are integers of 0 to 200, and s is an integer of 0 to 6, respectively. , P, q, and s are not 0 at the same time.)

（Ｘは前記と同じ、ｖ、ｗはそれぞれ１〜５０の整数。）

(X is the same as above, v and w are integers of 1 to 50, respectively.)

（ｙは１〜１００の整数。）

(Y is an integer from 1 to 100.)

Divalent perfluoroalkylene groups may be either linear or branched, for example _{-C 2 F 4 -, - C} 3 F 6 -, - C 4 F 8 -, - C 6 F 12 -, - C 8 F _16- , -C ₁₀ F _20- , -C ₂ F ₄ CF (CF ₃ ) C ₄ F _8- and the like are exemplified.

  Examples of the divalent perfluorooxyalkylene group include the following.

  Q is preferably a group represented by the following formula (5).

(Where R ¹ is a monovalent hydrocarbon selected from an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group, an aryl group, an aralkyl group, and a group in which some or all of the hydrogen atoms in these groups are substituted with halogen atoms. Group, R ² is a hydrogen atom or a monovalent hydrocarbon group similar to R ¹ , R ³ is an oxygen atom or an alkylene group having 1 to 8 carbon atoms, a cycloalkylene group, an arylene group, one of the hydrogen atoms of these groups A divalent hydrocarbon group selected from a group in which a part is substituted with a halogen atom, and a group in which the alkylene group and the arylene group are combined, R ⁴ is a monovalent hydrocarbon group similar to R ¹ , R ⁵ is R ¹ and From the same monovalent hydrocarbon group, or a monovalent hydrocarbon group containing an aliphatic unsaturated bond having 2 to 20 carbon atoms, and a group in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms Monovalent hydrocarbon chosen A group.)

Examples of R ¹ , R ² and R ⁴ :
R ¹ and R ⁴ are monovalent hydrocarbons selected from an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group, an aryl group, an aralkyl group, and a group in which some or all of the hydrogen atoms in these groups are substituted with halogen atoms. R ² is a hydrogen atom or a monovalent hydrocarbon group similar to R ¹ . Examples of the monovalent hydrocarbon group for R ¹ , R ² and R ⁴ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a hexyl group, an octyl group, and a decyl group. Alkyl groups, cyclopentyl groups, cyclohexyl groups, cycloheptyl groups and other cycloalkyl groups, phenyl groups, tolyl groups, xylyl groups, naphthyl groups and other aryl groups, benzyl groups, phenylethyl groups, phenylpropyl groups, methylbenzyl groups, etc. Or a chloromethyl group, a chloropropyl group, a bromoethyl group, a trifluoropropyl group or the like in which part or all of the hydrogen atoms of these groups are substituted with a halogen atom.

Illustration of R ⁵ :
R ⁵ is the same monovalent hydrocarbon group as R ¹ or a monovalent hydrocarbon group containing an aliphatic unsaturated bond having 2 to 20 carbon atoms. Examples of the monovalent hydrocarbon group containing an aliphatic unsaturated bond represented by R ⁵ include a vinyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a hexenyl group, a cyclohexenyl group, and a group having the following structure. The

(In order to show the bonding site with Si, Si is written in the chemical formula.)

  Or the following is illustrated as a group which substituted a part or all of the hydrogen atoms of these groups by the halogen atom.

(In order to show the bonding site with Si, Si is written in the chemical formula.)

Examples of divalent organic groups for R ³ :
R ³ is an oxygen atom or a divalent hydrocarbon group having 1 to 8 carbon atoms. Examples of the divalent hydrocarbon group for R ³ include alkylene groups such as methylene group, ethylene group, propylene group, methylethylene group, butylene group and hexamethylene group, cycloalkylene groups such as cyclohexylene group, phenylene group and tolylene. Groups, arylene groups such as xylylene groups, groups obtained by substituting some of the hydrogen atoms of these groups with halogen atoms, and divalent hydrocarbon groups selected from the groups obtained by combining the above alkylene groups and arylene groups. .

Z is preferably an organic group such as a monovalent hydrocarbon group having 1 to 30 carbon atoms, and may have an atom selected from oxygen, nitrogen, sulfur and silicon in the middle of bonding. A group in which a part or all of them are substituted with a halogen atom may be used. Specifically, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, etc. Cycloalkyl groups such as alkyl groups, cyclopentyl groups, cyclohexyl groups, cycloheptyl groups, aryl groups such as phenyl groups, tolyl groups, xylyl groups, naphthyl groups, aralkyl groups such as benzyl groups, phenylethyl groups, phenylpropyl groups, or the like A chloromethyl group, a bromoethyl group, a chloropropyl group, a trifluoropropyl group, 3,3,4,4,5, in which a part or all of the hydrogen atoms in the group is substituted with a halogen atom such as fluorine, chlorine or bromine 5,6,6,6-nonafluorohexyl group, ether bond, amide bond in the middle of these groups , An ester bond, a urethane bond, sulfonyl amide bond include laden group a siloxane bond.

(B) Component (B) Fluorinated Elastomer Cured Particles with an Average Particle Size of 0.001 to 200 μm Component (B) in the present invention is a fluorinated elastomer cured with an average particle size of 0.001 to 200 μm, preferably 0.05 to 50 μm. It is a physical particle. Although component (B) acts as a filler to component (A), can not be a sufficient amount when the average particle diameter of component (B) is less than 0.001 [mu] m, and when it exceeds 200μm final It is difficult to increase the rubber strength of a typical cured product.

  The fluorine-containing elastomer that is the raw material of the particles is particularly preferably one obtained by copolymerizing a radical copolymerizable monomer consisting of a monomer group containing vinylidene fluoride and / or tetrafluoroethylene. Specific examples of monomers other than vinylidene fluoride and tetrafluoroethylene include fluorinated ethylenically unsaturated monomers such as hexafluoropropylene, vinyl fluoride, chlorotrifluoroethylene, and 1-hydropentafluoropropene, and perfluoro Perfluorovinyl ethers such as methyl vinyl ether and perfluoropropyl vinyl ether, and fluorinated cyclic olefins such as perfluorocyclobutene and perfluoromethylcyclopropene are non-fluorinated hydrocarbons such as ethylene and propylene. Nomar, and the like.

  In order to cure the copolymer, a monomer having a functional group such as iodine, bromine or cyano group can be used in order to introduce a crosslinking site into the main chain of the polymer. These copolymers can produce a cured product as a single or a mixture of a plurality of copolymers. The method for curing the copolymer is not particularly limited, but known methods such as peroxide, polyol, amine crosslinking, or radiation crosslinking can be used, and curing by peroxide crosslinking or radiation crosslinking is particularly desirable.

  When amine crosslinking is employed as the crosslinking method, a primary or secondary polyamine is used as the crosslinking agent. When employing polyol crosslinking, a combination of a polyol such as bisphenol A or bisphenol AF and a crosslinking accelerator such as calcium hydroxide, barium hydroxide, guanidine, or imidazole is used. When the peroxide crosslinking is employed, a peroxide having a half-temperature of 100 ° C. or more in 10 hours, for example, dicumyl peroxide, cumyl hydroperoxide, t-butyl peroxide, or the like is generally used.

  When adopting amine crosslinking, polyol crosslinking, and peroxide crosslinking, various crosslinking agents are blended in the above-mentioned copolymer according to the crosslinking method. 0.1-10 mass parts is preferable with respect to 100 mass parts of copolymers, and, as for the compounding quantity of a crosslinking agent, 0.5-5 mass parts is more preferable. If the amount of the crosslinking agent exceeds 10 parts by mass, the physical properties may be adversely affected, and if it is 0.05 parts by mass or less, crosslinking is insufficient or the crosslinking rate is unfavorable.

  Furthermore, various additives can be mix | blended as needed. For example, a crosslinking aid, a reinforcing agent, an acid acceptor, an extender, a plasticizer, a colorant, and the like may be added. Specific examples of preferred crosslinking aids include triallyl cyanurate, triallyl isocyanurate, trimethallyl isocyanurate and N, N'-m-phenylene-dimaleimide, 1,3-butylene glycol dimethacrylate, trimethylolpropane trimethacrylate. Such polyunsaturated crosslinking aids are mentioned. Examples of the reinforcing agent include carbon black, graphite, silica, talc and the like. Examples of the acid acceptor include magnesium oxide, calcium oxide, lead oxide and the like. Examples of the bulking agent include inorganic salts such as barium sulfate and calcium carbonate. Examples of the plasticizer include calcium stearate, magnesium stearate, dioctyl phthalate, and dicresyl phthalate. Examples of the colorant include titanium oxide, molybdenum oxide, and iron oxide.

  The conditions for curing the above cured composition vary depending on the curing method, but are obtained by curing at a heating temperature of 100 to 250 ° C. for 5 to 120 minutes, and further at 100 to 300 ° C. for 1 to 30 as necessary. The physical properties of the cured secondary cured product can be stabilized by heat treatment for about an hour.

  The method for adjusting the cured product powder is not particularly limited, and examples thereof include a method by pulverizing the cured product and a method by curing the copolymer in the form of fine particles.

  In the case of the method by pulverization of the cured product, for example, the following procedure is shown. First, a copolymer and, if necessary, a filler, a crosslinking agent and the like are uniformly mixed by a kneader such as a calender roll or a kneader, and then a cured product is prepared in an appropriate form such as a sheet or block. The obtained cured product is immersed in a solvent that swells without dissolving, and the sufficiently swollen cured product is frozen in a glass transition temperature, preferably in a temperature environment below the embrittlement point, such as a cutter mill, jet mill, hammer mill, etc. Crush with a pulverizer. Alternatively, the powder can also be produced by a method in which the produced cured product is worn and powdered using a grinder such as silicone carbide.

  In the case of the method of curing the copolymer in the form of fine particles, an aqueous dispersion or non-aqueous dispersion of the copolymer is prepared, and this is crosslinked and cured by heating or radiation irradiation, and then cured by a technique such as spray drying. Collect the material powder. The cured fine particles obtained by these methods can be used after classification with a sieve or the like, if necessary.

  (B) Although the addition amount with respect to (A) component of fluorine-containing elastomer cured | curing material particle of a component is not restrict | limited, 10-300 mass parts with respect to 100 mass parts of (A) component, Especially 20-200 mass. Part is preferred. If there are too few said fluorine-containing elastomer hardened | cured material particles, sufficient cost effect will not be acquired, but if too large, the intensity | strength of the rubber | gum obtained by hardening will fall.

(C) Component Examples of the peroxide crosslinking agent of the component (C) of the present invention include dibenzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, t-butyl peroxyacetate, and t-butyl peroxide. Oxybenzoate, 2,5-dimethyl-2,5-bis-t-butylperoxyhexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, 1,6-hexanediol- Bis-t-butyl peroxycarbonate is exemplified, but 2,5-dimethyl-2,5-bis-t-butylperoxyhexane, t-butyl from the viewpoint of crosslinking efficiency, storage stability and scorch prevention. Peroxyisopropyl monocarbonate, t-butyl peroxy-2-ethylhexyl Monocarbonate, 1,6 - bis -t- butyl peroxy carbonate is preferred.

The peroxide crosslinking agent may be added in an amount sufficient to cure the component (A), but 0.1 to 10 parts by weight , particularly 0.5 to 100 parts by weight of the component (A). 3 parts by mass is preferred. If the amount is less than 0.1 parts by mass, the crosslinking may be insufficient or the crosslinking may be delayed. If the amount exceeds 10 parts by mass , the physical properties may be adversely affected.

  In order to enhance the practicality of the composition, various additives such as an internal release agent, a wetter, a pigment, and a dye can be added as necessary.

The fluororubber composition of the present invention is
(A) It can manufacture by the process of adding the fluorine-containing elastomer hardened | cured material particle of (B) component with respect to (A) component (b) and then the process of adding the crosslinking agent of (C) component.

  In the step (a), a kneader for rubber, a pressure kneader, a Banbury mixer, a two-roll rubber, and the like used for general rubber compounding may be used and kneaded while adding a filler.

  At the time of blending, there is no problem even at room temperature, but it may be heated in a temperature range where the polymer is not decomposed for the purpose of stabilizing shear heat, and the condition is 10 minutes at 100 to 300 ° C. About 8 hours is desirable.

  The step (b) is a step of blending the component (C) cross-linking agent, but as a device, a kneader, a pressure kneader, a Banbury mixer, etc. are not preferable because there is a risk of scorch phenomenon in which cross-linking proceeds due to mixed heat generation. Two rubber rolls that can perform the dispensing operation are desirable, and those having a cooling facility are preferable in order to suppress the progress of crosslinking due to heat generation during the kneading operation.

  The curing conditions of the composition of the present invention are preferably 1 to 30 minutes at 100 to 200 ° C. as a primary cure. If it is less than 100 ° C., the curing time becomes long, so that the industrial productivity may be inferior. If it exceeds 200 ° C., there is a risk of scorch generation, so 100 to 200 ° C. is preferable, and further 120 to 170 ° C. Is preferred. The curing time in that case may be appropriately selected as the time for completing the crosslinking reaction. Moreover, in order to stabilize the physical property of this composition, it is preferable to carry out secondary cure by heat processing for about 1 to 24 hours at 100-230 degreeC. The secondary cure is less effective at less than 100 ° C and may be thermally decomposed at more than 230 ° C. More preferably, it is suitable at 150 to 200 ° C. for 1 to 20 hours.

  The curable composition of the present invention can be used for various applications as a rubber product by curing and molding the composition. For example, diaphragms for fuel regulators, diaphragms for pulsation dampers, diaphragms for oil pressure switches, diaphragms for EGR, valves for canisters, valves for power control, O-rings for quick connectors, injectors, etc. O-rings such as O-rings, or rubber parts for automobiles such as sealing materials such as oil seals and cylinder head gaskets, diaphragms for pumps, valves, O-rings, packings, oil seals, gaskets, etc. Rubber parts for chemical plants, diaphragms, valves, O-rings, packings, gaskets, etc. Rubber parts for inkjet printers, rubber parts for semiconductor production lines, diaphragms for pumps, O-rings, packings, gaskets Analysis of rubber and joints, rubber parts for physics and chemistry equipment, rubber parts for medical equipment, tent film materials, sealants, molded parts, extruded parts, coating materials, copier roll materials, moisture-proof coating materials for electric sensors, potting materials for sensors, Rubber parts for aircraft such as fuel cell seals, laminated rubber cloth, aircraft engine oil, jet fuel, hydraulic oil, skid roll and other fluid piping O-rings, face seals, packing, gaskets, diaphragms, valves, etc. Can be used for etc.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example. In addition, in the following example, a part shows a mass part.

[Example 1]
(A) component

Ｒ^６はＣ_４Ｆ_９Ｃ_２Ｈ_４−又はＣＨ_２＝ＣＨＣ_４Ｆ_８Ｃ_２Ｈ_４−であって、その比率は５：５である。

R ⁶ is C ₄ F ₉ C ₂ H ₄ — or CH ₂ ═CHC ₄ F ₈ C ₂ H ₄ —, and the ratio is 5: 5.

A rubber sheet having a thickness of 1 mm was prepared from the composition below the component (B) in a 75-ton press for rubber under conditions of 170 ° C. and 10 minutes, and then post-cured at 200 ° C. for 4 hours. Hereinafter, all parts are parts by mass.

Viton GFLT 100 parts (Fluoro rubber made by DuPont Dow Elastomer)
MT carbon 30 parts calcium hydroxide 3 parts triallyl isocyanurate 3 parts perhexa 25B 2 parts (manufactured by Nippon Oil & Fats: 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane)

  The obtained rubber sheet having a hardness of 75 was swelled in tetrahydrofuran and then shredded, frozen in liquid nitrogen and pulverized, and the resulting powder was classified to obtain an average particle size of 23 μm. Fluoroelastomer cured product particles.

Component (C) Peroxide peroxide crosslinking agent: t-butyl peroxyisopropyl monocarbonate

  The above-mentioned components (A), (B), (C) and a crosslinking agent were mixed on a two-roll rubber roll in the following composition to obtain a curable fluororubber composition.

(A) Component 100 parts (B) Component 50 parts (C) Component 2 parts

  A rubber sheet having a thickness of 2 mm was prepared from the obtained composition with a 75-ton press for rubber under conditions of 170 ° C. and 10 minutes, and then post-cured at 200 ° C. for 4 hours to obtain a cured product having a hardness of 69. .

[Comparative Example 1]
The cured product sheet obtained in Example 1 and the cured product sheet having the composition of component (B) were subjected to Gehman torsion test based on JIS K 6261 to examine low temperature characteristics. The results are shown in Table 1.

[Table 1] Specific modulus temperature in Gehmann torsion test

[Comparative Example 2]
In place of the component (B) in Example 1, a composition using 30 parts of VP-NVX300 (trade name manufactured by Nippon Aerosil Co., Ltd., fumed silica treated with a silicon-based surface treatment agent) was applied to a 75-ton press for rubber. After creating a sheet of 2 mm thickness at 170 ° C. for 10 minutes, a post-curing was performed at 200 ° C. for 4 hours to obtain a sheet of hardness 70

[Comparative Example 3]
Table 2 shows the results of comparing the resistance to hydrofluoric acid of the cured product by the change in hardness after immersion in 10% hydrofluoric acid (room temperature, 168 h).

[Table 2] Hardness change due to immersion in 10% hydrofluoric acid

Claims (6)

(A) A polymer compound represented by the following general formula (1) having a viscosity at 25 ° C. of 1,000 Pa · s or more, 100 parts by mass

(Where n is an integer of 1 or more, Rf is a divalent perfluoroalkylene group or perfluorooxyalkylene group, Q is a group represented by the following formula (5), and Z represents a monovalent organic group. )

(Where R ¹ is a monovalent hydrocarbon selected from an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group, an aryl group, an aralkyl group, and a group in which some or all of the hydrogen atoms in these groups are substituted with halogen atoms. Group, R ² is a hydrogen atom or a monovalent hydrocarbon group similar to R ¹ , R ³ is an oxygen atom or an alkylene group having 1 to 8 carbon atoms, a cycloalkylene group, an arylene group, one of the hydrogen atoms of these groups A divalent hydrocarbon group selected from a group in which a part is substituted with a halogen atom, and a group in which the alkylene group and the arylene group are combined, R ⁴ is a monovalent hydrocarbon group similar to R ¹ , R ⁵ is R ¹ and From the same monovalent hydrocarbon group, or a monovalent hydrocarbon group containing an aliphatic unsaturated bond having 2 to 20 carbon atoms, and a group in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms Monovalent hydrocarbon chosen A group.)

(B) a curable fluorine, characterized by containing an average particle 10 to 300 parts by weight fluoroelastomer cured particle diameter 0.001~200μm (C) peroxide crosslinking agent 0.1 to 10 parts by weight Rubber composition. In the formula (1), Rf is selected from a divalent perfluoroalkylene group represented by C _m F _2m (m = 2 to 15) or a group represented by the following formulas (2), (3) and (4) A divalent perfluorooxyalkylene group,

(X is independently F or CF ₃ group, r is an integer of 2 to 6, t and u are each 1 or 2, p and q are integers of 0 to 200, and s is an integer of 0 to 6, respectively. , P, q, and s are not 0 at the same time.)

(X is the same as above, v and w are integers of 1 to 50, respectively.)

(Y is an integer from 1 to 100.)
2. The formula (1), wherein Z is a monovalent organic group having 1 to 30 carbon atoms which may have an atom selected from oxygen, nitrogen, sulfur and silicon in the middle of bonding and at the terminal . Composition. The curable fluororubber composition according to claim 1 or 2 , wherein the fluorine- containing elastomer cured product particles of component (B) are particles of a copolymer cured product comprising a monomer group containing vinylidene fluoride and / or tetrafluoroethylene.
An article having a fluororubber cured product obtained by curing the composition according to claim 1, 2 or 3 as a partial structure or an entire structure. The article according to claim 4, wherein the article is for an automobile, a chemical plant, an inkjet printer, a semiconductor production line, an analytical / physical instrument, a medical instrument, an aircraft or a fuel cell . The article according to claim 4 or 5, wherein the article is a diaphragm, a valve, an O-ring, an oil seal, a gasket, a packing, a joint or a face seal .