JP2005246950A - Rubber article comprising cured perfluoropolyether type fluorinated rubber composition and silicone rubber molding and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber article which can be made by integrally molding a cured material of a perfluoropolyether type fluorine-containing rubber composition and a silicone rubber molding at a stable interface, having both superior characteristics of the cured material of the fluorine-containing rubber composition such as solvent resistance, chemical resistance, heat-resistance and low-temperature characteristics and characteristics of the silicone rubber article at the same time and a method for manufacturing it. <P>SOLUTION: The rubber article is made by laminating (a) a peroxide crosslinking type perfluoropolyether type fluorine-containing rubber composition with a crosslinking site of Si-CH=CH<SB>2</SB>with (b) a silicone rubber molding and by curing (a) to be integrated with (b). Since uncured perfluoropolyether type fluorine-containing rubber composition can be integrally molded with the silicone rubber molding, the interface between both the rubbers can be kept constant, therefore dimensional precision is superior and it shows a great utility value in industrial applications. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rubber article obtained by integrating a cured product of a perfluoropolyether-based fluororubber uncured composition having good solvent resistance, chemical resistance, heat resistance, and low temperature characteristics with a silicone rubber molded article, and a method for producing the same. About.

Conventional vinylidene fluoride-based fluororubber is an elastomer having excellent heat resistance, chemical resistance, mechanical strength, and the like, and is therefore industrially used in a wide range of fields mainly in the automobile and machinery industries.
However, its chemical resistance is inadequate and easily swells in polar solvents such as ketones, lower alcohols, carbonyls, organic acids, etc. There is a disadvantage that the elongation is extremely lowered. Further, in terms of low temperature characteristics, rubber elasticity is lost at −20 ° C. or lower and the seal material cannot be used. Therefore, there is a general limit to use in cold regions.

Therefore, in order to improve these drawbacks, a liquid or millable type fluorinated curable composition mainly composed of a perfluoro compound and a fluorinated organohydrogenpolysiloxane has been proposed (Patent Documents 1 to 4: Japanese Patent No. 2990646 (Japanese Patent Laid-Open No. 8-199070), Japanese Patent Laid-Open No. 2000-007835, Japanese Patent Laid-Open No. 2001-106893, Japanese Patent Laid-Open No. 2003-201401).
However, since these fluorine-containing curable compositions are difficult to be blended with different types of inexpensive rubbers, their molded products are generally expensive, and their usage is limited.

Further, other rubbers may have excellent characteristics with respect to rubber physical properties and processability. Specifically, compared with silicone rubber, it is not as good as silicone rubber in terms of rubber strength, elongation, compression set, roll workability, mold releasability and the like.
Therefore, the above-mentioned fluorine-containing curable composition has the greatest characteristics of solvent resistance and chemical resistance. When the solvent and chemicals are in partial contact, only the contact portion is regarded as the fluorine-containing curable composition, and the others. For this part, a different rubber material may be preferable.

Japanese Patent No. 2990646 (Japanese Patent Laid-Open No. Hei 8-199070) JP 2000-007835 A JP 2001-106893 A JP 2003-201401 A

  The present invention has been made in view of the above circumstances, and a cured product of a perfluoropolyether-based fluorine-containing rubber composition and a silicone rubber molded product can be integrally formed at a stable interface. It is an object of the present invention to provide a rubber article having a portion excellent in solvent resistance, chemical resistance, heat resistance, and low temperature characteristics of a cured product and characteristics of silicone rubber, and a method for producing the same.

As a result of intensive studies to achieve the above object, the present inventors have found that a peroxide-crosslinked perfluoropolyether-based fluororubber uncured composition having a crosslinking site of Si—CH═CH ₂ is a cured silicone. The inventors have found that integral molding with a rubber molded product is possible, and have reached the present invention.

Accordingly, the present invention provides a rubber article obtained by bonding and integrating a cured product of the following perfluoropolyether-based fluorine-containing rubber composition and a silicone rubber molded article, and a method for producing the same.
Claim 1:
(A) A peroxide-crosslinking type perfluoropolyether-based fluorine-containing rubber composition in which the crosslinking site is Si—CH═CH ₂ is laminated on (b) a silicone rubber molded article, and the above (a) is cured (b ) And rubber articles.
Claim 2:
The rubber article according to claim 1, wherein the component (b) is a molded article of a peroxide-crosslinking type silicone rubber composition.
Claim 3:
The rubber article according to claim 1, wherein the component (b) is a molded article of an addition-crosslinking type silicone rubber composition.
Claim 4:
The perfluoropolyether-based fluorine-containing rubber composition (a) is
(A) a part of the alkenyl group of the perfluoro compound having at least two alkenyl groups in the molecule and having a divalent perfluoroalkylene structure or a divalent perfluoropolyether structure in the main chain; A polymer formed by adding a compound capable of addition reaction with an alkenyl group having at least two hydrosilyl groups in the molecule,
2. A crosslinkable fluororubber composition comprising (B) a reinforcing filler and (C) a peroxide crosslinking agent in an amount sufficient to cure the component (A). 4. The rubber article according to any one of items 1 to 3.
Claim 5:
The silicone rubber molded product of (b) above is
(D) Average composition formula (R ¹¹ ) _a SiO _{(4-a) / 2}
(In the formula, R ¹¹ is an unsubstituted or substituted monovalent hydrocarbon group, and a is a number satisfying 1.95 <a <2.05.)
A diorganopolysiloxane represented by the formula: 0.01 to 15 mol% of all R ¹¹ bonded to silicon atoms of the diorganopolysiloxane is a monovalent aliphatic unsaturated hydrocarbon group,
5. The silicone rubber composition containing (E) a reinforcing filler and (F) a crosslinking agent is cured after molding, and is cured according to any one of claims 1 to 4. Rubber articles.
Claim 6:
(A) A peroxide-crosslinking type perfluoropolyether-based fluorine-containing rubber composition in which the crosslinking site is Si—CH═CH ₂ is laminated on (b) a silicone rubber molded article, and then the rubber composition of (a) above is used. A method for producing a rubber article, wherein the rubber article is cured and adhered to the silicone rubber molded product of (b).
Claim 7:
A rubber product comprising the rubber article according to any one of claims 1 to 5 as a partial structure or an entire structure.
Claim 8:
The rubber product according to claim 7, which is a sealing material, an O-ring, a diaphragm, a hose, a cap or a valve material.

  In the molded product of the present invention, an uncured perfluoropolyether fluororubber composition can be integrally formed with a silicone rubber molded product, so that the interface between the two rubbers can be made constant and the dimensional accuracy can be improved. Excellent and industrial utility value.

As the perfluoropolyether-based fluorine-containing rubber composition in which the crosslinking site as the component (a) used in the present invention is Si—CH═CH ₂ , Japanese Patent No. 2990646 (JP-A-8-199070) is disclosed. (Patent Document 1), JP-A 2000-007835 (Patent Document 2), JP-A 2001-106893 (Patent Document 3), JP-A 2003-201401 (Patent Document 4) and the like. It is generally available as the trade name SIFEL series (manufactured by Shin-Etsu Chemical Co., Ltd.).

  The fluorine-containing rubber composition has two types of composition, a liquid rubber composition and a millable rubber composition. However, when the integral molding is performed, the material of the fluorine-containing rubber composition is higher than that of a LIMS material that complicates the mold structure. A millable rubber composition that is easy to handle and mold structure is desirable.

［但し、式中Ｒ¹は置換又は非置換の一価炭化水素基、Ｒ²は水素原子又は置換又は非置換の一価炭化水素基、Ｑは下記一般式（２）又は下記一般式（３）で示される基

（但し、式中Ｒ³は結合途中に酸素原子、窒素原子及びケイ素原子の１種又は２種以上を介在させてもよい置換又は非置換の二価炭化水素基を示す。）

（但し、式中Ｒ⁴及びＲ⁵はそれぞれ置換又は非置換の二価炭化水素基を示す。）、Ｒｆは二価のパーフルオロアルキレン基又は二価のパーフルオロポリエーテル基であり、ａは０以上の整数である。］ That is, in JP-A-8-199070 (Patent Document 1), (A ′) a fluorine-containing amide compound represented by the following general formula (1),

[Wherein R ¹ is a substituted or unsubstituted monovalent hydrocarbon group, R ² is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, Q is the following general formula (2) or the following general formula (3 ) Group

(However, in the formula, R ³ represents a substituted or unsubstituted divalent hydrocarbon group in which one or more of an oxygen atom, a nitrogen atom and a silicon atom may be interposed in the middle of bonding.)

(Wherein R ⁴ and R ⁵ each represent a substituted or unsubstituted divalent hydrocarbon group), Rf is a divalent perfluoroalkylene group or a divalent perfluoropolyether group, and a is It is an integer of 0 or more. ]

  (B ′) one or more monovalent perfluorooxyalkyl groups, monovalent perfluoroalkyl groups, divalent perfluorooxyalkylene groups or divalent perfluoroalkylene groups in one molecule; A composition comprising a fluorine-containing organohydrogensiloxane having at least one hydrosilyl group and (C ′) a catalytic amount of a platinum group compound, wherein the amount of the component (B ′) is aliphatic unsaturation in the composition There is disclosed a curable composition characterized in that the amount of hydrosilyl group (Si-H group) is 0.5 to 5 moles per mole of group.

  In addition, in Japanese Patent Application Laid-Open No. 2000-007835 (Patent Document 2), (A) a molecule having at least two alkenyl groups and a main chain having a divalent perfluoroalkylene structure or a divalent perfluoro group. A polymer in which a compound capable of addition reaction with an alkenyl group having at least two hydrosilyl groups in the molecule is added to a part of the alkenyl group of the perfluoro compound having a polyether structure, (B) a reinforcing filler, (C) A crosslinkable fluororubber composition comprising a sufficient amount of a crosslinking agent or peroxide crosslinking agent having a hydrosilyl group in the molecule to cure the component (A) Things are disclosed.

  In Japanese Patent Laid-Open No. 2001-106893 (Patent Document 3), the same component (A), component (B), component (C) as in Patent Document 2 described above, and at least one (D ′) component in the molecule A crosslinkable fluororubber composition comprising a surface treatment agent having a fluoroalkyl group or fluoropolyalkyl ether group and a silanol group in the molecule is disclosed.

（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”）補強性フィラー、（Ｃ”）パーオキサイド架橋剤を含有してなることを特徴とする架橋性フッ素ゴム組成物が開示されている。 Furthermore, in Japanese Patent Application Laid-Open No. 2003-201401 (Patent Document 4), (A ″) a polymer compound represented by the following general formula (4) having a viscosity at 25 ° C. of 1,000 Pa · s or more.

(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.)
A crosslinkable fluororubber composition comprising (B ″) a reinforcing filler and (C ″) a peroxide crosslinking agent is disclosed.

（Ｘはそれぞれ独立にＦ又はＣＦ₃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は前記と同じ、ｖ、ｗはそれぞれ１〜５０の整数である。）

（ｙは１〜１００の整数である。）
また、上記式（４）において、Ｑが、下記式（８）で表される基である。

（但し、Ｒ⁶は炭素数１〜１０のアルキル基、シクロアルキル基、アリール基、アラルキル基及びこれらの基の水素原子の一部又は全部をハロゲン原子で置換した基から選ばれる一価炭化水素基、Ｒ⁷は水素原子又はＲ⁶と同様の一価炭化水素基、Ｒ⁸は酸素原子又は炭素原子数１〜８のアルキレン基、シクロアルキレン基、アリーレン基、これらの基の水素原子の一部をハロゲン原子で置換した基、及び上記アルキレン基とアリーレン基とを組み合わせた基から選ばれる二価炭化水素基、Ｒ⁹はＲ⁶と同様の一価炭化水素基、Ｒ¹⁰はＲ⁶と同様の一価炭化水素基、又は炭素原子数２〜２０の脂肪族不飽和結合を含有する一価炭化水素基、及びこれらの基の水素原子の一部又は全部をハロゲン原子で置換した基から選ばれる一価炭化水素基を示す。） Here, in the above formula (4), Rf is a divalent perfluoroalkylene group represented by —C _m F _2m — (m = 2 to 15) or the following formulas (5), (6), (7) A divalent perfluorooxyalkylene group selected from the group represented by:

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

(X is the same as described above, and v and w are each an integer of 1 to 50.)

(Y is an integer of 1 to 100.)
In the above formula (4), Q is a group represented by the following formula (8).

(Wherein R ⁶ is a monovalent hydrocarbon selected from alkyl groups having 1 to 10 carbon atoms, cycloalkyl groups, aryl groups, aralkyl groups, and groups in which some or all of the hydrogen atoms in these groups have been substituted with halogen atoms. Group, R ⁷ is a hydrogen atom or a monovalent hydrocarbon group similar to R ⁶ , R ⁸ is an oxygen atom or an alkylene group having 1 to 8 carbon atoms, a cycloalkylene group, an arylene group, one of 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 combination of the above alkylene group and arylene group, R ⁹ is a monovalent hydrocarbon group similar to R ⁶ , R ¹⁰ is R ⁶ 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 Indicates the selected monovalent hydrocarbon group )

  Furthermore, in the said Formula (4), Z is a C1-C30 monovalent organic group which may have the atom chosen from oxygen, nitrogen, sulfur, and silicon in the middle of a coupling | bonding.

Among these, particularly described in JP-A-2000-007835 (Patent Document 2) and JP-A-2001-106893 (Patent Document 3),
(A) a part of the alkenyl group of the perfluoro compound having at least two alkenyl groups in the molecule and having a divalent perfluoroalkylene structure or a divalent perfluoropolyether structure in the main chain; A polymer formed by adding a compound capable of addition reaction with an alkenyl group having at least two hydrosilyl groups in the molecule,
A crosslinkable fluororubber composition comprising (B) a reinforcing filler and (C) a peroxide crosslinking agent in an amount sufficient to cure the component (A) is preferred.

  In this case, examples of the reinforcing filler of the component (B) include carbon black, fumed silica, fumed silica treated with a surface treating agent containing silicon in the molecule, and the like. There are two types of composition forms, a liquid rubber composition and a millable rubber composition, both of which are preferably blended with silica powder as a reinforcing filler, and are important in terms of adhesiveness.

  As such silica, in the perfluoropolyether-based fluorine-containing rubber composition, mechanical strength, thermal stability, weather resistance, chemical resistance or flame retardancy is improved, heat shrinkage during curing is reduced, and the composition is cured. Fumed silica, wet silica, pulverized silica and the like can be mentioned for the purpose of reducing the thermal expansion coefficient of the elastic body obtained in this manner, and these may be treated with various surface treatment agents. . Among these, fumed silica is particularly preferable from the viewpoint of improving mechanical strength and dispersion stability of each composition. Further, fumed silica is treated with a silicon compound-based surface treatment such as silane from the viewpoint of improving dispersibility. What was processed with the agent is preferable.

  Hydrophobizing agents for dry process silica called fumed silica include hydrolyzable silicon compounds such as dimethyldichlorosilane and organochlorosilanes such as trimethylchlorosilane, silazane compounds such as hexamethyldisilazane, and hexa Cyclic silazanes such as methylcyclotrisilazane are preferred.

The specific surface area of silica is preferably set to 50 m ² / g or more to improve the mechanical properties, even greater thickening at the silica compounded into the composition, 300 meters for blending becomes difficult ² / G or less.

  In order to perform this hydrophobization treatment, the silica fine powder whose surface has been treated with a surface treatment agent is preferably pretreated directly in a powder state, and generally known techniques are used as normal treatment methods. For example, the untreated silica fine powder and the treatment agent are placed in a mechanical kneading apparatus sealed at normal pressure or in a fluidized bed, and if necessary, at room temperature or heat treatment in the presence of an inert gas. In some cases, a catalyst and water for accelerating hydrolysis may be used, and may be prepared by kneading and drying. The blending amount of the treatment agent may be equal to or more than the amount calculated from the coating area of the treatment agent.

  Furthermore, the bulk density of silica is preferably 30 to 80 g / l. When the bulk density of silica is less than 30 g / l, the viscosity of the composition increases, so that blending may be difficult. When it exceeds 80 g / l, a sufficient reinforcing effect may not be provided.

  The content thereof is 1 to 50% by mass in the perfluoropolyether-based fluorine-containing rubber composition, and if it is less than 1% by mass, the adhesion may be adversely affected, and the rubber physical properties may be inferior. If the content exceeds 50% by mass, the adhesiveness is improved, but the elongation and strength as a rubber material may be insufficient. More preferably, the silica content is 5 to 30% by mass.

  On the other hand, the silicone rubber molded product as the component (b) may be a cured product obtained by molding a silicone rubber uncured composition by pressing or HAV, and a crosslinking system and a processing method can be arbitrarily selected.

  The silicone rubber here is described in detail in “Silicone Handbook” (edited by Kunio Ito, Nikkan Kogyo Shimbun, August 31, 1990), including chapter 9 silicone rubber and chapter 10 liquid silicone. Examples include rubber, modified silicone rubber of Chapter 11 and fluorosilicone rubber of Chapter 15. Silicone rubber (Chapter 9) and fluorosilicone rubber (Chapter 15) are most preferably used.

The silicone rubber composition that gives these silicone rubbers is generally peroxide crosslinking cured with a peroxide and addition crosslinking cured with a Si-H group-containing compound and a platinum group metal catalyst.
As such a silicone rubber composition, for example,
(D) The following average composition formula (I)
(R ¹¹ ) _a SiO _{(4-a) / 2} (I)
(In the formula, R ¹¹ is an unsubstituted or substituted monovalent hydrocarbon group, and a is a number satisfying 1.95 <a <2.05.)
A diorganopolysiloxane represented by the formula: 0.01 to 15 mol% of all R ¹¹ bonded to silicon atoms of the diorganopolysiloxane is a monovalent aliphatic unsaturated hydrocarbon group,
A silicone rubber composition containing (E) a reinforcing filler and (F) a crosslinking agent may be mentioned.

Here, the diorganopolysiloxane of component (D) has the following average composition formula (I)
(R ¹¹ ) _a SiO _{(4-a) / 2} (I)
(In the formula, R ¹¹ is an unsubstituted or substituted monovalent hydrocarbon group, and a is a number satisfying 1.95 <a <2.05.)
In the total R ¹¹ bonded to the silicon atom of the diorganopolysiloxane, 0.01 to 15 mol% is a monovalent aliphatic unsaturated hydrocarbon group. When the content of the aliphatic unsaturated hydrocarbon group is less than 0.01 mol%, a cured product having sufficient tear strength may not be obtained. When the content exceeds 15 mol%, the resulting cured product is obtained. May become inconvenient, and there may be inconveniences such as insufficient tear strength.

Examples of the monovalent aliphatic unsaturated hydrocarbon group include alkenyl groups having 2 to 8 carbon atoms such as a vinyl group and an allyl group. Among them, a vinyl group is preferable. In addition, as R ¹¹ other than the aliphatic unsaturated hydrocarbon group, preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms can be mentioned. For example, an alkyl group such as a methyl group or an ethyl group; an aryl group such as a phenyl group; an aralkyl group such as a benzyl group; a part or all of hydrogen atoms of these groups are substituted with a halogen atom or the like, for example, trifluoropropyl Examples thereof include groups such as a group, and among these, a methyl group is preferable. The (D) component diorganopolysiloxane may have a hydroxyl group bonded to a silicon atom.

  In the average composition formula (I), a is a number satisfying 1.95 <a <2.05. When a is 1.95 or less, a stable linear polymer may not be obtained, and gelation tends to occur. When a is 2.05 or more, it may be difficult to become a high molecular weight polymer.

  In addition, the degree of polymerization of the (D) component diorganopolysiloxane is preferably 1,000 or more, and more preferably 2,000 or more, in order to ensure sufficient mechanical strength of the resulting cured product. It is preferable that it is preferably 3,000 to 10,000.

（式中、ｋは１以上の整数、ｍは１以上の整数であり、ｋ＋ｍは、好ましくは１，０００以上の整数であり、更に好ましくは２，０００以上の整数であり、特に好ましくは３，０００〜１０，０００の整数である。但し、ｋ及びｍは、ケイ素原子に結合する全有機基中の−ＣＨ＝ＣＨ₂基の割合が０．０１〜１５モル％となるような数値である。複数のＲ¹²は同一でも異なってもよく、メチル基、ビニル基又は水酸基である。）
で表される化合物；下記一般式（ＩＩＩ）： Specific examples of the (D) component diorganopolysiloxane include the following general formula (II):

(In the formula, k is an integer of 1 or more, m is an integer of 1 or more, k + m is preferably an integer of 1,000 or more, more preferably an integer of 2,000 or more, particularly preferably 3). K and m are numerical values such that the proportion of —CH═CH ₂ groups in all organic groups bonded to the silicon atom is 0.01 to 15 mol%. The plurality of R ¹² may be the same or different and are a methyl group, a vinyl group or a hydroxyl group.)
A compound represented by the following general formula (III):

（式中、ｋは１以上の整数、ｍは１以上の整数、ｎは１以上の整数であり、ｋ＋ｍ＋ｎは、好ましくは１，０００以上の整数であり、更に好ましくは２，０００以上の整数であり、特に好ましくは３，０００〜１０，０００の整数である。但し、ｋ、ｍ及びｎは、ケイ素原子に結合する全有機基中の−ＣＨ＝ＣＨ₂基の割合が０．０１〜１５モル％となるような数値である。複数のＲ¹³は同一でも異なってもよく、メチル基、ビニル基、３，３，３−トリフルオロプロピル基又は水酸基である。）
で表される化合物；下記一般式（ＩＶ）：

(In the formula, k is an integer of 1 or more, m is an integer of 1 or more, n is an integer of 1 or more, k + m + n is preferably an integer of 1,000 or more, more preferably an integer of 2,000 or more. Particularly preferably, it is an integer of 3,000 to 10,000, provided that k, m, and n have a ratio of —CH═CH ₂ groups in all organic groups bonded to silicon atoms of 0.01 to (The numerical value is 15 mol%. The plurality of R ¹³ may be the same or different and are a methyl group, a vinyl group, a 3,3,3-trifluoropropyl group or a hydroxyl group.)
A compound represented by the following general formula (IV):

（式中、ｋは１以上の整数、ｍは１以上の整数、ｎは１以上の整数であり、ｋ＋ｍ＋ｎは、好ましくは１，０００以上の整数であり、更に好ましくは２，０００以上の整数であり、特に好ましくは３，０００〜１０，０００の整数である。但し、ｋ、ｍ及びｎは、ケイ素原子に結合する全有機基中の−ＣＨ＝ＣＨ₂基の割合が０．０１〜１５モル％となるような数値である。複数のＲ¹⁴は同一でも異なってもよく、メチル基、ビニル基、フェニル基又は水酸基である。）
で表される化合物等が例示され、それらの中でも上記一般式（ＩＩ）で表される化合物が好ましい。

(In the formula, k is an integer of 1 or more, m is an integer of 1 or more, n is an integer of 1 or more, k + m + n is preferably an integer of 1,000 or more, more preferably an integer of 2,000 or more. Particularly preferably, it is an integer of 3,000 to 10,000, provided that k, m, and n have a ratio of —CH═CH ₂ groups in all organic groups bonded to silicon atoms of 0.01 to (The numerical value is 15 mol%. The plurality of R ¹⁴ may be the same or different and are a methyl group, a vinyl group, a phenyl group, or a hydroxyl group.)
A compound represented by the general formula (II) is preferable among them.

  The diorganopolysiloxane of component (D) can be produced by a known method, for example, a cyclic polysiloxane (siloxane) obtained by (co) hydrolyzing one or more of organohalosilanes. In the presence of a basic catalyst or an acidic catalyst.

The reinforcing filler of component (E) imparts mechanical strength to the resulting cured product. For example, fumed silica, precipitated silica, fused silica, quartz powder, diatomaceous earth, aluminum silicate, oxidation Examples thereof include titanium, zinc oxide, iron oxide, alumina, calcium carbonate, zinc carbonate, and carbon black. Among them, it is preferable to use silica in order to make the reinforcing property sufficient, and usually a specific surface area of 10 m ² / g or more, preferably 100 m ² / g or more is used. Particularly preferably, fumed silica and precipitated silica having a specific surface area of 100 to 400 m ² / g are used. In addition, the reinforcing filler of component (E) not only provides mechanical strength to the resulting cured product, but also imparts electrical conductivity, thermal conductivity, and the like.

Examples of the reinforcing filler of the component (E) include chlorosilanes such as (CH ₃ ) ₃ SiCl, (CH ₃ ) ₂ SiCl ₂ , (CH ₃ ) SiCl ₃ ; CH ₂ ═CHSi (OCH ₃ ) ₃ , ( Alkoxysilanes such as CH ₃ ) ₂ Si (OCH ₃ ) ₂ and CH ₃ Si (OCH ₃ ) ₃ ; organosilazanes such as (CH ₃ ) ₃ SiNHSi (CH ₃ ) ₃ ;

（式中、ｉ及びｊは、ｉ＞０、ｊ＞１、１＜ｉ＋ｊ＜１００を満たす数である。）
で表されるシリコーンオイル等の表面処理剤で表面処理したものも使用可能である。また、表面処理剤の加水分解性を調整、促進するために少量の水を添加してもよい。

(Where i and j are numbers satisfying i> 0, j> 1, 1 <i + j <100).
Those treated with a surface treatment agent such as silicone oil can be used. A small amount of water may be added to adjust and promote the hydrolyzability of the surface treatment agent.

  (E) The compounding quantity of a component is the range of 5-200 mass parts normally with respect to 100 mass parts of (D) component, Preferably it is the range of 10-100 mass parts. When the blending amount of the component (E) is too small, the processability is insufficient and a sufficient reinforcing effect cannot be obtained, and when it is too large, the workability, mold flowability at the time of processing, etc. are reduced, or the silicone rubber machine In some cases, the target strength may decrease.

  (F) The crosslinking agent of a component should just be a thing which can harden the silicone rubber composition of this invention. As the component (F), a combination of an organohydrogenpolysiloxane and a platinum group metal catalyst or an organic peroxide can be used depending on the curing method.

  As the component (F), an organohydropolypolysiloxane when a combination of an organohydrogenpolysiloxane and a platinum group metal catalyst is used has at least two Si-H groups in one molecule. The structure used may be any of linear, cyclic or branched structures. The Si—H group may be at the end of the molecular chain or in the middle of the molecular chain. Furthermore, it is usually preferable to use an organohydrogenpolysiloxane having a polymerization degree of 300 or less.

Specifically, the organohydrogenpolysiloxane is a diorganopolysiloxane terminated with a dimethylhydrogensilyl group; a copolymer comprising dimethylsiloxy units, methylhydrogensiloxy units and terminal trimethylsiloxy units; Low viscosity fluid comprising dimethylhydrogensiloxy units and SiO ₂ units; 1,3,5,7-tetrahydrogen-1,3,5,7-tetramethylcyclotetrasiloxane; 1-propyl-3,5 , 7-trihydrogen-1,3,5,7-tetramethylcyclotetrasiloxane; 1,5-dihydrogen-3,7-dihexyl-1,3,5,7-tetramethylcyclotetrasiloxane Illustrated. In the organohydrogenpolysiloxane, the Si-H group contained in the organohydrogenpolysiloxane is usually 0.5 to 3.0 mol, preferably 1 per mol of the aliphatic unsaturated hydrocarbon group of the diorganopolysiloxane (D) component. It is preferable to use an amount of 0.0 to 2.0 mol.

  The platinum group metal catalyst is used as a catalyst for the hydrosilylation reaction between the aliphatic unsaturated hydrocarbon group of the (D) component diorganopolysiloxane and the Si-H group in the organohydrogenpolysiloxane. And is usually in the range of 0.1 to 2,000 ppm, preferably 1 to 1,000 ppm (as a platinum group metal) with respect to the total amount of the organopolysiloxane of component (D) and the organohydrogenpolysiloxane. Used in. Examples of such platinum group metal-based catalysts include finely divided metal platinum catalysts described in US Pat. No. 2,970,150, and chlorides described in US Pat. No. 2,823,218. Platinum acid catalysts, platinum-hydrocarbon complex compounds described in US Pat. No. 3,159,601 and US Pat. No. 3,159,662, US Pat. No. 3,516,946 Platinum-based compounds such as chloroplatinic acid-olefin complex compounds described in US Pat. No. 3,775,452 and platinum-vinylsiloxane complexes described in US Pat. No. 3,814,780. A catalyst or the like can be used.

  When the combination of organohydrogenpolysiloxane and platinum group metal catalyst is used as component (F) and the silicone rubber composition of the present invention is cured by hydrosilylation reaction, the storage stability at room temperature is good. In order to maintain an appropriate pot life, it is also possible to add a reaction control agent such as acetylene alcohols such as methylvinylcyclotetrasiloxane and ethynylcyclohexanol. Curing by the hydrosilylation reaction is performed by heating at a temperature of 60 to 400 ° C. for about 1 minute to 5 hours.

  When an organic peroxide is used as the component (F), the organic peroxide is usually 0.01 to 3 parts by mass, preferably 0.05 to 100 parts by mass of the (D) component diorganopolysiloxane. -1 mass part is mix | blended. As the organic peroxide, those usually used for curing organic peroxide-curing silicone rubber can be used without any particular restrictions. Specifically, for example, benzoyl peroxide, bis ( 2,4-dichlorobenzoyl) peroxide, di-t-butyl peroxide, 2,5-dimethyl-di-t-butylperoxyhexane, t-butylperbenzoate, t-butylperoxyisopropyl carbonate, dicumylper Examples include oxides. These may be used singly or in combination of two or more.

When the organic peroxide is used as the component (F) and the composition of the present invention is cured, the composition is usually heated at a temperature of 100 to 400 ° C. for about 1 minute to 5 hours.
Moreover, as (F) component, the combination of said organohydrogen polysiloxane and a platinum group metal catalyst and an organic peroxide can also be used together.
In addition, the fluorine-containing rubber composition used in the present invention can be peroxide-crosslinked similarly to the silicone rubber composition.

  In integrating the fluorine-containing rubber composition with the silicone rubber molded product, there are two types of cross-linking forms for integral molding because both the fluorine-containing rubber composition and the silicone rubber composition are peroxide crosslinking and addition crosslinking. Although there are four types of combinations, unexpectedly, the crosslinking form of the silicone molded product is irrelevant, and integral molding is possible if the fluorine-containing rubber composition is a peroxide crosslinking system.

  In other combinations of the uncured fluorine-containing rubber addition cross-linking composition and the silicone rubber molded product cured by addition cross-linking or peroxide cross-linking, peeling at the interface occurs and integral molding is impossible.

  Regarding molding conditions for obtaining a silicone rubber molded product, the primary cure is preferably 100 to 200 ° C. for 1 to 30 minutes. 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.

  As a processing method, a processing method generally used for silicone rubber, such as press molding using a mold, calendar molding, and extrusion molding, may be selected according to the purpose.

  In order to stabilize the physical properties of silicone rubber, secondary curing is generally performed by heat treatment at 100 to 230 ° C. for about 1 to 24 hours. However, when used in the present invention, the presence or absence of secondary curing is used. Can be integrally molded.

Next, the manufacturing method of the article of the present invention will be described with reference to the drawings.
In order to process an article such as a rubber cap (medicinal plug) as shown in FIG. 1, the shape of a portion that does not require chemical resistance is manufactured by pressing the silicone rubber 1 or punching a sheet molded product. The silicone rubber is charged into a rubber cap mold, and the uncured fluorine-containing composition 2 is charged into a portion where chemical resistance is required, and then integrally molded.

  FIG. 2 shows a case where a two-layer rubber sheet is molded. The thickness of the two-layer rubber sheet is adjusted with a press or a calender roll, and the processed silicone rubber product 1 molded by HAV crosslinking is put into a mold, and then uncured fluorine-containing material The rubber composition 2 can be easily manufactured by charging, pressing and crosslinking.

  FIG. 3 shows a three-layer structure produced by the same manufacturing method as in FIG. 2. The chemical resistance of the fluorine-containing rubber composition 2 is obtained at the surface portion, and compression set and rubber strength characteristics are sandwiched between two layers. The improved silicone rubber material 1 can be improved.

  The curing condition of the fluorine-containing rubber composition for obtaining the article of the present invention is 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. Further, in order to stabilize the physical properties of the article, it is preferable to perform secondary curing by heat treatment at 100 to 230 ° C. for about 1 to 24 hours. 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 article of the present invention can be used for various applications. In other words, rubber parts for automobiles that require oil resistance, specifically diaphragms for fuel regulators, diaphragms for pulsation dampers, diaphragms for oil pressure switches, diaphragms for EGR, canister valves, power control, etc. Rubber parts for chemical plants, such as valves such as valves, O-rings such as O-rings for quick connectors and O-rings for injectors, or sealing materials such as oil seals and cylinder head gaskets, specifically Diaphragms for pumps, valves, O-rings, hoses, packings, oil seals, rubber parts for ink jet printers, rubber parts for semiconductor production lines, and more specifically equipment that comes into contact with chemicals Die for Rubber parts for analysis and physics and chemistry equipment, such as valves that require low friction and wear resistance, such as seals such as flamm, valves, O-rings, packings, gaskets, etc. Specifically, diaphragms for valves, valves, seal parts (O-rings, packing, etc.), rubber parts for medical equipment, specifically pumps, valves, joints, etc., tent film materials, sealants, molded parts, extruded parts, coating materials, copier roll materials, electrical use It is useful for moisture-proof coating materials, potting materials for sensors, sealing materials for fuel cells, laminated rubber cloths, 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.

Composition A used in Examples and Comparative Examples : Perfluoropolyether-based fluorine-containing rubber composition (II): SIFEL 9700 (manufactured by Shin-Etsu Chemical Co., Ltd., containing components (A) to (C), peroxide crosslinking / Millable type standard composition)
B: Perfluoropolyether-based fluorine-containing rubber composition (I): SIFEL5701 (manufactured by Shin-Etsu Chemical Co., Ltd., containing components (A) to (C), addition-crosslinking / millable type standard composition)
The fluororubber compositions (I) and (II) both contain hydrophobized surface-treated silica in the range of 5 to 30% by mass as the component (B).
C: Silicone rubber composition (I): KE951 peroxide cross-linking, containing (D) to (F) components, standard blending composition (manufactured by Shin-Etsu Chemical Co., Ltd.)
D: Silicone rubber composition (II): KE951 addition crosslinking, containing (D) to (F) components, standard blending composition (manufactured by Shin-Etsu Chemical Co., Ltd.)
E: Fluorosilicone rubber composition: FE471 (manufactured by Shin-Etsu Chemical Co., Ltd., peroxide crosslinking, standard blend composition)
F: Vinylidene-based fluororubber composition: Viton GLT (manufactured by DuPont, peroxide cross-linked, standard composition)

Manufacture of molded article for evaluation In order to obtain a molded article having the structure shown in FIG.
(1) A material other than the perfluoropolyether-based fluorine-containing rubber composition is press-molded into a 1 mm sheet at 10 cm square under molding conditions suitable for each compounding. As a next step after this, a post-curing at 200 ° C. for 4 hours is also produced.
(2) The cured molded sheet is charged into a 10 mm square and 2 mm thick mold.
(3) Uncured perfluoropolyether-based fluorine-containing rubber composition that has been separated into 1.1 to 1.3 mm sheets with two rolls for rubber is cut into 10 cm squares and charged into a mold.
(4) After crosslinking at 150 ° C. for 10 minutes with a 75-ton press for rubber, post-curing is performed at 200 ° C. for 4 hours.

[Method for evaluating interfacial adhesion (integral molding interface)]
(1) Peeled state: The degree of rubber peeling at the interface when the slit was cut with a cutter knife near the rubber interface and peeled was evaluated.
○: Rubber cohesive failure and material interface is stable ×: Separation without any cohesive failure at the interface (2) Solvent swelling: 24 hours in toluene (vs. silicone) or methyl ethyl ketone (vs fluorosilicone, vinylidene fluoro rubber) The state when only one rubber material was swollen by immersion was evaluated.
○: Stable rubber interface state that does not peel even when one rubber swells ×: Peels within 24 hours

[Examples 1 to 6]
Evaluations were made on molded articles in which the fluorine-containing rubber composition and the silicone rubber molded article were integrally molded in the combinations shown in Table 1.
By using the peroxide-crosslinked fluorine-containing rubber composition, the interface of integral molding was stable in all cases.

[Comparative Examples 1-5]
Table 2 shows combinations of comparative examples.
All the rubber molded articles of the comparative examples were not post-cured.
In Comparative Examples 1 and 2, the addition-crosslinked fluorine-containing rubber composition was easily peeled off from the interface and could not be integrally formed into a silicone rubber molded product.
In Comparative Example 3, it was a peroxide-crosslinked fluorine-containing rubber composition, but could not be integrally molded into a fluororubber molded product.
In Comparative Examples 4 and 5, contrary to the examples, an attempt was made to integrally form a peroxide-crosslinked silicone rubber composition on a cured product of a perfluoropolyether-based fluorine-containing rubber composition. .

It is sectional drawing which shows an example of the rubber article of this invention. It is sectional drawing which shows the other example of the rubber article of this invention. It is sectional drawing which shows another example of the rubber article of this invention.

Explanation of symbols

1 Silicone rubber material 2 Perfluoropolyether fluoro rubber

Claims (8)

(A) A peroxide-crosslinking type perfluoropolyether-based fluorine-containing rubber composition in which the crosslinking site is Si—CH═CH ₂ is laminated on (b) a silicone rubber molded article, and the above (a) is cured (b ) And rubber articles.   The rubber article according to claim 1, wherein the component (b) is a molded article of a peroxide-crosslinking type silicone rubber composition.   The rubber article according to claim 1, wherein the component (b) is a molded article of an addition-crosslinking type silicone rubber composition. The perfluoropolyether-based fluorine-containing rubber composition (a) is
(A) a part of the alkenyl group of the perfluoro compound having at least two alkenyl groups in the molecule and having a divalent perfluoroalkylene structure or a divalent perfluoropolyether structure in the main chain; A polymer formed by adding a compound capable of addition reaction with an alkenyl group having at least two hydrosilyl groups in the molecule,
2. The crosslinkable fluororubber composition comprising (B) a reinforcing filler and (C) a peroxide crosslinking agent in an amount sufficient to cure the component (A). 4. The rubber article according to any one of items 1 to 3. The silicone rubber molded product of (b) above is
(D) Average composition formula (R ¹¹ ) _a SiO _{(4-a) / 2}
(In the formula, R ¹¹ is an unsubstituted or substituted monovalent hydrocarbon group, and a is a number satisfying 1.95 <a <2.05.)
A diorganopolysiloxane represented by the formula: 0.01 to 15 mol% of all R ¹¹ bonded to silicon atoms of the diorganopolysiloxane is a monovalent aliphatic unsaturated hydrocarbon group,
5. The silicone rubber composition containing (E) a reinforcing filler and (F) a crosslinking agent is formed and cured after molding. 5. Rubber articles. (A) A peroxide-crosslinking type perfluoropolyether-based fluorine-containing rubber composition in which the crosslinking site is Si—CH═CH ₂ is laminated on (b) a silicone rubber molded article, and then the rubber composition of (a) above is used. A method for producing a rubber article, wherein the rubber article is cured and adhered to the silicone rubber molded product of (b).   A rubber product comprising the rubber article according to any one of claims 1 to 5 as a partial structure or an entire structure. The rubber product according to claim 7, which is a sealing material, an O-ring, a diaphragm, a hose, a cap or a valve material.

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