JP2005281482A - Curable fluoropolyether-based rubber composition and rubber product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable fluoropolyether-based rubber compound that has excellent heat resistance, chemical resistance, solvent resistance, water repellency, oil repellency, weathering performance and adhesion-preventive properties and rubber product. <P>SOLUTION: This curable fluoropolyether-based rubber composition comprises (A) a straight-chain fluoropolyether compound represented by formula (1) [wherein X is CH<SB>2</SB>, CH<SB>2</SB>O or Y-NR-CO (Y is CH<SB>2</SB>or dimethylphenylsilylene, R is H, methyl, phenyl or aryl) X'is CH<SB>2</SB>, OCH<SB>2</SB>or CO-NR-Y'(Y'is CH<SB>2</SB>or dimethylphenylsilylene, R is H, methyl, phenyl or aryl); p is 0 or 1, r is an integer, m + n is an integer]; (B) a silica filler of which the surfaces are made hydrophobic; (C) a nonfunctional straight chain fluoropolyether compound of C<SB>s</SB>F<SB>2s+1</SB>-O-(CF<SB>2</SB>O)<SB>d</SB>(CF<SB>2</SB>CF<SB>2</SB>O)<SB>e</SB>-C<SB>s</SB>F<SB>2s+1</SB>(s is 1 to 3, d + e = 50 to 180); (D) an organosilicon compound bearing a SiH group; and (E) a catalyst for hydrosilylation reaction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention provides a cured product having excellent heat resistance, water repellency, oil repellency, solvent resistance, chemical resistance, weather resistance, and excellent anti-adhesion properties to metals, etc., O-rings, diaphragms, valve materials The present invention relates to a curable fluoropolyether rubber composition and a rubber product that are suitably used for, for example.

  Conventionally, linear fluoropolyether compounds having at least two alkenyl groups in the molecule and having a perfluoroalkyl ether structure in the main chain are suitable for various applications due to the properties of the perfluoroalkyl ether structure. It is used. In this case, silica-based fillers such as dry-process silica called fumed silica and wet-process silica called precipitated silica used for reinforcement of silicone rubber and the like are used as curable fluoropolyether-based fillers. It has been found that by blending with rubber, the mechanical properties of the resulting cured product can be dramatically improved. As a result, a fluoropolyether rubber composition having excellent balance of properties such as heat resistance, chemical resistance, solvent resistance, water repellency, oil repellency and weather resistance can be obtained (Patent Document 1: Patent No. 2990646). This is sufficient for most applications.

  However, such a fluoropolyether-based rubber composition is sufficient in performance for most applications, but as a sealing member and diaphragm molding application as a component of a valve mechanism that is used by being crimped to various metals, What has excellent anti-sticking property is required, and for this reason, improvement of anti-sticking property is a problem.

  For example, a curable fluoropolyether rubber composition is used for seal members and diaphragms that improve the sealing performance as components of valve mechanisms. Normally, rubber materials are fixed to parts such as metals that are in contact with them. This causes various problems. For this reason, conventionally, surface treatment with mica, molybdenum disulfide, or the like has been performed in order to reduce the adhesion of the rubber material. However, in the said process, there existed a problem that adhesiveness with the rubber material of a base material was inadequate.

Japanese Patent No. 2990646

  The present invention has been made in view of the above circumstances and is excellent in heat resistance, chemical resistance, solvent resistance, water repellency, oil repellency, weather resistance, etc., and is also a curable fluoropolyether type excellent in anti-sticking property. An object is to provide a rubber composition and a rubber product.

As a result of intensive studies to achieve the above object, the present inventors have found that (A) the molecule represented by the following general formula (1) has at least two alkenyl groups, and A linear fluoropolyether compound having a fluoroalkyl ether structure, (B) a silica-based filler having a specific surface area of 50 to 300 m ² / g, which has been hydrophobized, and (C) represented by the following general formula (3) A non-functional linear fluoropolyether compound containing no alkenyl group, (D) an organosilicon compound having at least two hydrogen atoms bonded to silicon atoms in the molecule, and (E) a hydrosilylation reaction catalyst. The curable fluoropolyether rubber composition suppresses the increase in viscosity of the composition due to the blending of the filler, and has excellent heat resistance, chemical resistance, solvent resistance, water repellency, oil repellency, weather resistance, etc. It has excellent anti-sticking properties, liquid injection molding (LIM molding) is possible, gives a cured product with excellent mechanical properties, and has found that rubber products made from this cured product are of high quality. Invented the invention.

［式中、Ｘは−ＣＨ₂−、−ＣＨ₂Ｏ−又は−Ｙ−ＮＲ−ＣＯ−（但し、Ｙは−ＣＨ₂−又は下記構造式（２）で示されるｏ，ｍ又はｐ位のジメチルフェニルシリレン基で表される基、Ｒは水素原子、メチル基、フェニル基又はアリル基である。）であり、Ｘ’は−ＣＨ₂−、−ＯＣＨ₂−又は−ＣＯ−ＮＲ−Ｙ’−（但し、Ｙ’は−ＣＨ₂−又は下記構造式（２’）で示される基であり、Ｒは水素原子、メチル基、フェニル基又はアリル基である。）であり、ｐは独立に０又は１、ｒは２〜６の整数、ｍ＋ｎ＝５０〜１８０の整数である。］

（Ｂ）比表面積が５０〜３００ｍ²／ｇの表面が疎水化処理されたシリカ系充填剤
１０〜５０質量部
（Ｃ）下記一般式（３）で示され、重量平均分子量が５，０００〜１５，０００であるアルケニル基を含有しない無官能直鎖状フルオロポリエーテル化合物 ０．２〜１０質量部
Ａ−Ｏ−（ＣＦ₂Ｏ）_d（ＣＦ₂ＣＦ₂Ｏ）_e−Ａ （３）
（式中、Ａは式：Ｃ_sＦ_2s+1−（ｓは１〜３）で表される基であり、ｄ＋ｅ＝５０〜１８０の整数である。）
（Ｄ）分子中にケイ素原子に結合した水素原子を少なくとも２個有する有機ケイ素化合物
（Ａ）成分を硬化させる有効量
（Ｅ）ヒドロシリル化反応触媒 触媒量
を含有してなることを特徴とする硬化性フルオロポリエーテル系ゴム組成物、及びそれを硬化してなるゴム製品を提供する。 Therefore, the present invention
(A) Linear fluoropolyether compound having at least two alkenyl groups in the molecule represented by the following general formula (1) and having a perfluoroalkyl ether structure in the main chain 100 parts by mass

[Wherein, X is -CH ₂ -, - CH ₂ O-or -Y-NR-CO- (where, Y is -CH ₂ - or indicated by o, m or p-position by the following structural formula (2) A group represented by a dimethylphenylsilylene group, R is a hydrogen atom, a methyl group, a phenyl group or an allyl group.) And X ′ is —CH ₂ —, —OCH ₂ — or —CO—NR—Y ′. Wherein Y ′ is —CH ₂ — or a group represented by the following structural formula (2 ′), R is a hydrogen atom, a methyl group, a phenyl group or an allyl group, and p is independently 0 or 1, r is an integer of 2-6, m + n = an integer of 50-180. ]

(B) Silica-based filler whose surface having a specific surface area of 50 to 300 m ² / g is hydrophobized.
10 to 50 parts by mass (C) Non-functional linear fluoropolyether compound which is represented by the following general formula (3) and does not contain an alkenyl group having a weight average molecular weight of 5,000 to 15,000 parts by _{A-O- (CF 2 O)} d (CF 2 CF 2 O) e -A (3)
(In the formula, A is a group represented by the formula: C _s F _{2s + 1} − (s is 1 to 3), and d + e = an integer of 50 to 180.)
(D) Organosilicon compound having at least two hydrogen atoms bonded to silicon atoms in the molecule
(A) Effective amount for curing component (E) Hydrosilylation reaction catalyst Provided is a curable fluoropolyether-based rubber composition characterized by containing a catalytic amount, and a rubber product obtained by curing the same. .

  The curable fluoropolyether rubber composition of the present invention has excellent heat resistance, water repellency, oil repellency, solvent resistance, chemical resistance and weather resistance inherent to fluoropolyether rubber, and also has excellent anti-sticking properties. From the cured product, a high-quality rubber product can be obtained, and can be suitably used as an O-ring, a diaphragm, a valve material, and the like.

Hereinafter, the present invention will be described in more detail.
(A) Component linear fluoropolyether compound The component (A) linear fluoropolyether compound has at least two alkenyl groups in the molecule and a divalent perfluoroalkyl in the main chain. It has an ether structure and is used as the base polymer of the composition.

［式中、Ｘは−ＣＨ₂−、−ＣＨ₂Ｏ−又は−Ｙ−ＮＲ−ＣＯ−（但し、Ｙは−ＣＨ₂−又は下記構造式（２）で示されるｏ，ｍ又はｐ位のジメチルフェニルシリレン基で表される基、Ｒは水素原子、メチル基、フェニル基又はアリル基である。）であり、Ｘ’は−ＣＨ₂−、−ＯＣＨ₂−又は−ＣＯ−ＮＲ−Ｙ’−（但し、Ｙ’は−ＣＨ₂−又は下記構造式（２’）で示される基であり、Ｒは水素原子、メチル基、フェニル基又はアリル基である。）であり、ｐは独立に０又は１、ｒは２〜６の整数、ｍ＋ｎ＝５０〜１８０の整数である。］

This linear fluoropolyether compound is represented by the following general formula (1).

[Wherein, X is -CH ₂ -, - CH ₂ O-or -Y-NR-CO- (where, Y is -CH ₂ - or indicated by o, m or p-position by the following structural formula (2) A group represented by a dimethylphenylsilylene group, R is a hydrogen atom, a methyl group, a phenyl group or an allyl group.) And X ′ is —CH ₂ —, —OCH ₂ — or —CO—NR—Y ′. Where Y ′ is —CH ₂ — or a group represented by the following structural formula (2 ′), and R is a hydrogen atom, a methyl group, a phenyl group or an allyl group. 0 or 1, r is an integer of 2-6, m + n = an integer of 50-180. ]

  Specific examples of the linear fluoropolyether compound represented by the general formula (1) include those represented by the following formula, and one of these may be used alone or in combination of two or more.

（式中、ｍ及びｎはそれぞれ上記一般式（１）で定義したｍ，ｎと同じ意味を示す。）

(In the formula, m and n have the same meaning as m and n defined in the general formula (1), respectively.)

  The linear fluoropolyether compound of the above formula (1) preferably has a weight average molecular weight of 8,500 to 30,000, particularly 15,000 to 25,000 as determined by gel permeation chromatography.

(B) The silica-based filler (B) component whose surface having a specific surface area of 50 to 300 m ² / g is hydrophobized is used to reinforce the fluoropolyether rubber composition. Type fillers are dry process silica called fumed silica, wet process silica called precipitated silica, and organochlorosilanes such as dimethyldichlorosilane and trimethylchlorosilane which are silicon compounds having hydrolyzable groups. In addition, the surface may be hydrophobized with a silazane compound such as hexamethyldisilazane, or the surface may be hydrophobized with dimethylpolysiloxane having a low polymerization degree.

The specific surface area of the hydrophobized silica is 50 m ² / g or more and 300 m ² / g or less, preferably 100 m ² / g or more and 200 m ² / g or less. If the specific surface area is less than 50 m ² / g, the mechanical properties cannot be improved. If the specific surface area exceeds 300 m ² / g, the thickening at the time of compounding silica into the composition becomes large and the compounding becomes difficult.

  The silica fine powder obtained by treating the surface of the silica with a surface treating agent for the hydrophobization treatment is preferably pretreated directly in a powder state, and a generally well-known technique is adopted as a normal treatment method. 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 at room temperature or heat treatment in the presence of an inert gas as necessary. Mixing treatment may be used, and a catalyst and water for accelerating hydrolysis may be used in some cases, and it can 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.

  The compounding quantity of the said silica type filler is 10-50 mass parts with respect to 100 mass parts of (A) component, More preferably, it is 15-30 mass parts. If the amount is less than 10 parts by mass, the mechanical strength is not improved, and if the amount is more than 50 parts by mass, the increase in viscosity is large and blending is difficult.

(C) The non-functional linear fluoropolyether compound (C) component bleeds on the surface of the cured product and is used for improving the anti-sticking property of the fluoropolyether rubber composition. 3) A non-functional linear fluoropolyether compound containing no alkenyl group.
_{A-O- (CF 2 O)} d (CF 2 CF 2 O) e -A (3)
(In the formula, A is a group represented by the formula: C _s F _{2s + 1} — (s is 1 to 3), and d + e = 50 to 180, preferably an integer of 80 to 150.)

  The weight average molecular weight of the non-functional linear fluoropolyether compound not containing an alkenyl group represented by the general formula (3) needs to be 5,000 to 15,000 in order to control bleeding to the cured product surface. And preferably 7,000 to 10,000. If the weight average molecular weight is less than 5,000, it will be incorporated into the material and will not be surface-bleeded, so the anti-sticking property will not improve. If the weight average molecular weight is greater than 15,000, bleeding to the surface will not occur. It becomes excessive and the deterioration of the sticking prevention property with time increases.

  The compounding amount of the non-functional linear fluoropolyether compound containing no alkenyl group is 0.2 to 10 parts by mass, more preferably 0.5 to 5.0 parts per 100 parts by mass of component (A). Part by mass. If the amount is less than 0.2 parts by mass, the amount is too small to improve the anti-sticking property. If the amount is more than 10 parts by mass, the mechanical properties are greatly deteriorated and the bleed to the surface becomes excessive.

(D) The organosilicon compound of component (D) having at least two hydrogen atoms bonded to silicon atoms in the molecule acts as a crosslinking agent and chain extender of component (A). The organosilicon compound of component (D) is particularly limited as long as it has two or more, preferably three or more, hydrosilyl groups (SiH groups) bonded to silicon atoms in one molecule. Although not intended, considering compatibility with component (A), dispersibility, and uniformity after curing, one or more monovalent perfluorooxyalkyl groups and monovalent perfluoroalkyl groups per molecule Those having a divalent perfluorooxyalkylene group or a divalent perfluoroalkylene group are preferred.

（式中、ｆは２〜２００、好ましくは２〜１００、ｈは１〜３の整数である。）
２価のパーフルオロオキシアルキレン基：

（式中、ｉ及びｊは１以上の整数、ｉ＋ｊの平均は２〜２００、好ましくは２〜１００である。）
−（ＣＦ₂Ｏ）_r−（ＣＦ₂ＣＦ₂Ｏ）_s−ＣＦ₂−
（但し、ｒ及びｓはそれぞれ１〜５０の整数である。） Examples of the perfluorooxyalkyl group, perfluoroalkyl group, perfluorooxyalkylene group, and perfluoroalkylene group include those represented by the following general formula.
Monovalent perfluoroalkyl group:
C _g F _{2g + 1} −
(In the formula, g is an integer of 1 to 20, preferably 2 to 10.)
Divalent perfluoroalkylene group:
−C _g F _2g −
(In the formula, g is an integer of 1 to 20, preferably 2 to 10.)
Monovalent perfluorooxyalkyl group:

(In the formula, f is 2 to 200, preferably 2 to 100, and h is an integer of 1 to 3.)
Divalent perfluorooxyalkylene group:

(In the formula, i and j are integers of 1 or more, and the average of i + j is 2 to 200, preferably 2 to 100.)
_{- (CF 2 O) r -} (CF 2 CF 2 O) s -CF 2 -
(However, r and s are each an integer of 1 to 50.)

In addition, these perfluoroalkyl group, perfluorooxyalkyl group, perfluoroalkylene group or perfluorooxyalkylene group may be directly bonded to the silicon atom, but are bonded to the silicon atom via a divalent linking group. You may do it. Here, the divalent linking group may be an alkylene group, an arylene group, a combination thereof, or a group in which an ether bond oxygen atom, an amide bond, a carbonyl bond, or the like is interposed in these groups. Those having 2 to 12 carbon atoms are preferred. Specific examples include the following groups.
—CH ₂ CH ₂ —
—CH ₂ CH ₂ CH ₂ —
_{-CH 2 CH 2 CH 2 OCH 2} -
—CH ₂ CH ₂ CH ₂ —NH—CO—
_{-CH 2 CH 2 CH 2 -N (} Ph) -CO-
_{-CH 2 CH 2 CH 2 -N (} CH 3) -CO-
—CH ₂ CH ₂ CH ₂ —O—CO—
(However, Ph is a phenyl group.)

  The component (D) contains a monovalent or divalent fluorine-containing substituent in the organosilicon compound, that is, a perfluoroalkyl group, a perfluorooxyalkyl group, a perfluoroalkylene group or a perfluorooxyalkylene group. Examples of the monovalent substituent bonded to the silicon atom other than the valent organic group include, for example, methyl groups, ethyl groups, propyl groups, butyl groups, hexyl groups, cyclohexyl groups, octyl groups, decyl groups and other alkyl groups, vinyl Group, alkenyl group such as allyl group, aryl group such as phenyl group, tolyl group and naphthyl group, aralkyl group such as benzyl group and phenylethyl group, and at least part of hydrogen atoms of these groups are chlorine atom, cyano group Substituted with, for example, chloromethyl group, chloropropyl group, cyanoethyl group, etc. Or such a substituted hydrocarbon group.

  As the organosilicon compound of component (D), any of cyclic, chain, three-dimensional network, and combinations thereof may be used.

  Further, the number of silicon atoms in the molecule in the organosilicon compound of component (D) is not particularly limited, but it is usually preferably 2 to 60, particularly about 3 to 30.

  Examples of such organosilicon compounds include the following compounds. In the following formulae, Me represents a methyl group, and Ph represents a phenyl group. In addition, these compounds can be used individually by 1 type or in combination of 2 or more types.

（但し、ｍは１〜２０、平均１０の整数、ｎは１〜１０、平均６の整数である。）

(However, m is an integer of 1 to 20 and an average of 10, and n is an integer of 1 to 10 and an average of 6.)

を表し、またｎは１〜３０の整数、ｍは１〜３０の整数で、かつｎ＋ｍは２〜６０、平均２〜５０を満足する。）

N is an integer of 1 to 30, m is an integer of 1 to 30, and n + m is 2 to 60, and satisfies an average of 2 to 50. )

を表し、またｎは１〜３０の整数、ｍは１〜３０の整数で、かつｎ＋ｍは２〜６０、平均２〜５０を満足する。）

N is an integer of 1 to 30, m is an integer of 1 to 30, and n + m is 2 to 60, and satisfies an average of 2 to 50. )

（但し、ｎは１〜６０、平均３〜５０の整数を表す。）

(However, n represents an integer of 1 to 60 and an average of 3 to 50.)

（但し、ｎは１〜６０、平均３〜５０の整数を表す。）

(However, n represents an integer of 1 to 60 and an average of 3 to 50.)

（但し、ｎは１〜６０、平均３〜５０の整数を表す。）

(However, n represents an integer of 1 to 60 and an average of 3 to 50.)

  The blending amount of the component (D) may be any effective amount that cures the component (A). Usually, the entire composition system, particularly the vinyl group, allyl group, cycloalkenyl group, etc. contained in the component (A) The amount of hydrosilyl group (D) component, that is, SiH group, is preferably 0.5 to 5 mol, more preferably 1 to 2 mol, per mol of alkenyl group. If the blending amount is too small, the degree of cross-linking becomes insufficient, and if it is too large, chain length extension takes precedence, curing may be insufficient or foamed, and heat resistance, compression set characteristics, etc. may be deteriorated. In addition, the compounding quantity with respect to (A) component of this (D) component shall be 0.1-50 mass parts with respect to 100 mass parts of (A) component normally, Especially shall be the range of 0.5-30 mass parts. You can also.

(E) Hydrosilylation reaction catalyst Examples of the component (E) hydrosilylation reaction catalyst include transition metals, for example, platinum group metals such as Pt, Rh, and Pd, and compounds of these transition metals. Since these compounds are generally precious metal compounds and are expensive, platinum or platinum compounds that are relatively easily available are preferably used.

Examples of the platinum compound include chloroplatinic acid; a complex of chloroplatinic acid and an olefin such as ethylene; a complex of chloroplatinic acid and an alcohol or vinylsiloxane; platinum supported on a carrier such as silica, alumina, or carbon. Although it can illustrate, it is not limited to these. Examples of platinum group metal compounds other than platinum compounds include rhodium, ruthenium, iridium and palladium compounds, such as
RhCl (PPh ₃ ) ₃
RhCl (CO) (PPh ₃ ) ₂
RhC1 (C ₂ H ₄ ) ₂
Ru ₃ (CO) ₁₂
IrCl (CO) (PPh ₃ ) ₂
Pd (PPh ₃ ) ₄
(Ph represents a phenyl group.)
Etc.

  The amount of these catalysts used is not particularly limited, and a desired curing rate can be obtained with a so-called catalyst amount, but it takes a form supported on a carrier such as silica or alumina or diluted with a solvent. Since the amount of catalyst also varies depending on the form and dilution ratio of the catalyst, in order to obtain an economical viewpoint or a good cured product, 0.1 to 1, in terms of platinum group metal, relative to the total amount of the curable composition 000 ppm (mass), particularly in the range of about 0.1 to 500 ppm (mass) is preferable.

Other Components In addition to the components (A) to (E) described above, various conventionally known additives can be blended as optional components in the composition of the present invention as long as the effects of the present invention are not impaired. Examples of such components include 1-ethyl-1-hydroxycyclohexane, 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, and 3-methyl-1- Control agents for hydrosilylation reaction catalysts such as acetylene alcohols such as penten-3-ol and phenylbutynol, and 3-methyl-3-penten-1-yne and 3,5-dimethyl-3-hexen-1-yne; Adhesion imparting agents such as organosiloxanes having alkoxy, epoxy and SiH groups in the molecule represented by the structural formula; pigments (for example, iron oxide, cerium oxide, carbon black, etc.), colorants such as dyes; antioxidants Agents and the like.

Composition Composition The composition of the present invention may be constructed as a so-called one-component type in which all the essential components (A) to (E) are handled as one composition depending on the application. Alternatively, for example, a part of the component (A), a part of the component (B), a part of the component (C) and the component (D) are used as one composition, and the remainder of the component (A) The remainder of the component, the remainder of the component (C) and the component (E) may be configured as a so-called two-component type, and these may be mixed at the time of use.

  The composition thus obtained preferably has a viscosity at 25 ° C. (according to JIS K7117) in the range of 50 to 2,000 Pa · s, particularly 200 to 1,000 Pa · s, and the viscosity is too low. However, if it is too high, the moldability may be inferior.

  The composition of the present invention can be easily cured by allowing it to stand at room temperature or heating, but it is usually thermally at room temperature (for example, 10 to 30 ° C.) to 200 ° C. for 5 minutes to 24 hours. It is preferable to cure.

  The curable fluoropolyether rubber composition of the present invention can be molded by a general method, but since it has the above-mentioned viscosity, so-called LIM molding is possible.

  The curable fluoropolyether rubber composition of the present invention can be used for various applications. 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 O-rings such as O-rings, or rubber parts for automobiles such as sealing materials such as oil seals and cylinder head gaskets; pump diaphragms, valves, O-rings, packings, oil seals, gaskets, etc. Rubber parts for chemical plants; Rubber parts for inkjet printers such as diaphragms, valves, O-rings, packings, gaskets, etc .; Rubber parts for semiconductor manufacturing lines; Diaphragms for pumps, O-rings, packings, valves Analysis of joints, rubber parts for physics and chemistry equipment and rubber parts for medical equipment; tent film materials, sealants, molded parts, extruded parts, coating materials, copier roll materials, moisture-proof coating materials for sensors, potting materials for sensors, fuel cells Rubber materials for aircraft such as O-rings, face seals, packings, gaskets, diaphragms, valves, etc. for fluid piping such as aircraft engine oil, jet fuel, hydraulic oil, skid roll, etc. Etc. are useful.

  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, a part shows a mass part by the following example, and a viscosity is a value of 25 degreeC.

[Example 1]
Hexamethyldisilazane with 100 parts of a polymer represented by the following formula (4) (viscosity: 4.4 Pa · s, weight average molecular weight: 16,500, vinyl group content: 0.012 mol / 100 g) as a treating agent. The treated silica having a specific surface area of 180 (m ² / g) was blended with a planetary mixer at a blending ratio of 25 parts, and then kneaded for 1 hour. After kneading, the mixture was heat-treated at 170 ° C. for 2 hours to produce a base.

  Furthermore, with respect to 125 parts of the base, 2.0 parts of a non-functional linear fluoropolyether compound having a weight average molecular weight of 8,000 represented by the following formula (5) and chloroplatinic acid are represented by the following formula (6). Contains 0.2 part of a toluene solution (platinum concentration 0.5 mass%) of a catalyst modified with the compound shown, 0.4 part of a 50% toluene solution of ethynylcyclohexanol, and a SiH group represented by the following formula (7) 3.35 parts of an organosilicon compound was added and mixed uniformly to obtain a curable fluoropolyether rubber composition (viscosity (according to JIS K7117): 430 Pa · s).

  The sticking property of the obtained curable fluoropolyether rubber composition was evaluated by the following method. Table 1 shows the measurement results of stickiness. The specific surface area of the powder was measured by the following method.

Measuring method of specific surface area of powder:
The specific surface area of the powder was measured by a BET method using a surface area measuring device (manufactured by Shibata Scientific Instruments Co., Ltd.).
Evaluation of adhesiveness:
From the obtained composition, a cured sheet having a thickness of 1 mm was formed under conditions of press curing at 150 ° C. for 10 minutes, and further oven curing at 200 ° C. for 4 hours, and affixed to a metal plate (SUS304). A load was applied so as to compress 10%, and the mixture was left at room temperature (23 ° C.) and 180 ° C. for 72 hours.

  After standing, the end of the cured product is removed at a speed of 5 (cm / min) so as to be peeled off at 180 degrees with respect to the metal plate attached with the end of the cured product of the 25 mm wide test piece sandwiched at room temperature. Pull up and peel off the stuck sheet from the metal plate. At that time, the load when the cured product was peeled from the metal plate was measured using a FUDOH rheometer (manufactured by Rheotech Co., Ltd.) (gf / 25 mm).

[Example 2]
Production of a base in the same manner as in Example 1 except that a compound having a weight average molecular weight of 9,800 represented by the above formula (5) (provided d + e = 150) is used as the non-functional linear fluoropolyether compound. Then, the composition was blended to obtain a curable fluoropolyether rubber composition. About the obtained composition, the stickiness was measured by the same method as Example 1. The results are shown in Table 1.

[Comparative Example 1]
Except not using a non-functional linear fluoropolyether compound, the production of the base and the blending of the composition were performed in the same manner as in Example 1, and a curable fluoropolyether rubber composition (viscosity (according to JIS K7117)). : 520 Pa · s). About the obtained composition, the stickiness was measured by the same method as Example 1. The results are shown in Table 1.

[Comparative Example 2]
Production of a base in the same manner as in Example 1 except that a compound having a weight average molecular weight of 4,000 represented by the above formula (5) (where d + e = 15) is used as the non-functional linear fluoropolyether compound. And a composition were mixed to obtain a curable fluoropolyether rubber composition (viscosity (according to JIS K7117): 380 Pa · s). About the obtained composition, the stickiness was measured by the same method as Example 1. The results are shown in Table 1.

[Comparative Example 3]
Production of a base in the same manner as in Example 1 except that a compound having a weight average molecular weight of 16,000 represented by the above formula (5) (where d + e = 350) is used as the non-functional linear fluoropolyether compound. And a composition were mixed to obtain a curable fluoropolyether rubber composition (viscosity (according to JIS K7117): 620 Pa · s). About the obtained composition, the stickiness was measured by the same method as Example 1. The results are shown in Table 1.

Claims (6)

(A) Linear fluoropolyether compound having at least two alkenyl groups in the molecule represented by the following general formula (1) and having a perfluoroalkyl ether structure in the main chain 100 parts by mass

[Wherein, X is -CH ₂ -, - CH ₂ O-or -Y-NR-CO- (where, Y is -CH ₂ - or indicated by o, m or p-position by the following structural formula (2) A group represented by a dimethylphenylsilylene group, R is a hydrogen atom, a methyl group, a phenyl group or an allyl group.) And X ′ is —CH ₂ —, —OCH ₂ — or —CO—NR—Y ′. Where Y ′ is —CH ₂ — or a group represented by the following structural formula (2 ′), and R is a hydrogen atom, a methyl group, a phenyl group or an allyl group. 0 or 1, r is an integer of 2-6, m + n = an integer of 50-180. ]

(B) Silica-based filler whose surface having a specific surface area of 50 to 300 m ² / g is hydrophobized.
10 to 50 parts by mass (C) Non-functional linear fluoropolyether compound which is represented by the following general formula (3) and does not contain an alkenyl group having a weight average molecular weight of 5,000 to 15,000 parts by _{A-O- (CF 2 O)} d (CF 2 CF 2 O) e -A (3)
(In the formula, A is a group represented by the formula: C _s F _{2s + 1} − (s is 1 to 3), and d + e = an integer of 50 to 180.)
(D) Organosilicon compound having at least two hydrogen atoms bonded to silicon atoms in the molecule
(A) Effective amount for curing component (E) Hydrosilylation reaction catalyst A curable fluoropolyether rubber composition comprising a catalytic amount.   The curable fluoropolyether rubber composition according to claim 1, wherein the composition viscosity at 25 ° C. is 50 to 2,000 Pa · s.   The curable fluoropolyether rubber composition according to claim 1 or 2, which is used for LIM molding.   A rubber product comprising a cured product of the curable fluoropolyether rubber composition according to claim 1.   The rubber product according to claim 4, which is used for automobiles, chemical plants, inkjet printers, semiconductor production lines, analytical / physical equipment, medical equipment, aircraft or fuel cells.   The rubber product according to claim 4 or 5, which is a diaphragm, valve, O-ring, oil seal, gasket, packing, joint or face seal.