JP5083564B2 - Fluorosilicone rubber composition and laminate of fluorosilicone rubber and dimethylsilicone rubber - Google Patents

Description

  The present invention relates to a fluorosilicone rubber composition that provides a fluorosilicone rubber that is particularly excellent in adhesion to dimethylsilicone rubber, and a laminate of fluorosilicone rubber and dimethylsilicone rubber comprising a cured product of the fluorosilicone rubber composition.

  Fluorosilicone rubber is excellent in heat resistance, cold resistance, oil resistance, fuel oil resistance, compression resilience, and the like, and is widely used as parts for transportation equipment such as automobiles and airplanes and parts for petroleum shipping equipment. When used as a material for automobiles, particularly as a turbo hose, there is a case where it is molded with a two-layer structure of a dimethyl silicone rubber composition and a fluorosilicone rubber composition. Fluorosilicone rubber is selected for the hose inner layer because oil resistance is particularly required. On the other hand, the hose outer layer side is superior to fluorosilicone rubber in terms of the high rebound and ironing resistance of dimethylsilicone rubber. As a two-layer structure of dimethyl silicone rubber and fluorosilicone rubber. However, due to the difference in compatibility between the two polymers, even if the fluorosilicone rubber composition and the dimethylsilicone rubber composition are laminated and vulcanized, the adhesion at the interface is very poor, and it is expected that they will easily peel off.

（式中、Ｒ⁴は炭素数２〜８の非置換又は置換の一価脂肪族不飽和炭化水素基、炭素数１〜８の非置換の一価脂肪族飽和炭化水素基、芳香族炭化水素基又は水酸基を示し、ｘは０〜２の整数、ｍ，ｎは互いに独立な正数である。）
で示されるようなシロキサンをジメチルシリコーンゴム組成物あるいはフロロシリコーンゴム組成物に添加することで接着性を持たせることが推奨されている。しかし、この方法では上記シロキサンを比較的大量に添加することが必要であるため、最終的にゴム自身が目的とする物理的強度や伸びを得られないことがある。 In this case, in Japanese Patent Laid-Open No. 2006-328303 (Patent Document 1), the following formula (8)

Wherein R ⁴ is an unsubstituted or substituted monovalent aliphatic unsaturated hydrocarbon group having 2 to 8 carbon atoms, an unsubstituted monovalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, or an aromatic hydrocarbon. A group or a hydroxyl group, x is an integer of 0 to 2, and m and n are mutually independent positive numbers.)
It is recommended that the siloxane as shown by the above be added to the dimethyl silicone rubber composition or the fluorosilicone rubber composition to provide adhesion. However, in this method, since it is necessary to add the siloxane in a relatively large amount, the physical strength and elongation desired by the rubber itself may not be finally obtained.

  Japanese Patent Application Laid-Open No. 2008-156564 (Patent Document 2) proposes co-vulcanization of a dimethylsilicone rubber composition containing an organohydrogenpolysiloxane and a fluororubber composition. It is not adhesion with silicone rubber. Further, even if an organohydrogenpolysiloxane mainly having a methyl group recommended in this publication is added to a fluorosilicone rubber composition, a remarkable effect is not obtained in adhesion to dimethylsilicone rubber.

JP 2006-328303 A JP 2008-156564 A

  The present invention has been made in view of the above circumstances, and when a dimethyl silicone rubber composition and a fluorosilicone rubber composition are laminated and vulcanized, the fluorosilicone gives a fluorosilicone rubber excellent in adhesion to the dimethylsilicone rubber interface. It is an object of the present invention to provide a rubber composition and a laminate (laminate structure) of a fluorosilicone rubber and a dimethylsilicone rubber comprising a cured product of the fluorosilicone rubber composition.

  As a result of intensive studies to achieve the above object, the present inventor added 0.1 to 30 parts by mass of an organohydrogenpolysiloxane having a trifluoropropyl group in the molecule to the fluorosilicone rubber composition. The present inventors have found that adhesion at the interface is excellent when co-vulcanized with a dimethyl silicone rubber composition. In this case, when the molded product obtained by curing the fluorosilicone rubber composition is used as a material for automobiles, particularly as a turbo hose, the dimethyl silicone rubber may be molded into a two-layer structure. At this interface, it was very difficult to peel off, and it was found to be excellent in adhesion to the dimethylsilicone rubber composition, leading to the present invention.

で示されるシロキサン単位をそれぞれ１分子中に少なくとも１個有するオルガノハイドロジェンポリシロキサン：０．１〜３０質量部
（Ｄ）有機過酸化物加硫剤：触媒量
を含有してなることを特徴とするジメチルシリコーンゴムとの接着用フロロシリコーンゴム組成物。
［請求項２］
（Ｃ）成分のオルガノハイドロジェンポリシロキサンが下記式（４）、（５）又は（６）

で表されるシロキサン単位を１分子中に少なくとも１個有することを特徴とする請求項１記載のフロロシリコーンゴム組成物。
［請求項３］
（Ｃ）成分のオルガノハイドロジェンポリシロキサンが下記式（７）

で表されるシロキサン単位を１分子中に少なくとも１個有することを特徴とする請求項１又は２記載のフロロシリコーンゴム組成物。
［請求項４］
フロロシリコーンゴムが、請求項１〜３のいずれか１項記載のフロロシリコーンゴム組成物の硬化物からなることを特徴とする、フロロシリコーンゴムとジメチルシリコーンゴムとの積層体。 Accordingly, the present invention provides the following fluorosilicone rubber composition and a laminate of fluorosilicone rubber and dimethylsilicone rubber comprising a cured product of the fluorosilicone rubber composition.
[Claim 1]
(A) The following average composition formula (1)
R ¹ _a R ² _b R ³ _c SiO _{(4-abc) / 2} (1)
(In the formula, R ¹ is a trifluoropropyl group, R ² is an unsubstituted or substituted monovalent aliphatic unsaturated hydrocarbon group having 2 to 8 carbon atoms, R ³ is a hydroxyl group, and an unsubstituted one having 1 to 8 carbon atoms. A monovalent aliphatic saturated hydrocarbon group or a monovalent aromatic hydrocarbon group having 6 to 8 carbon atoms, a, b and c are 0.96 ≦ a ≦ 1.01, 0.0001 ≦ b ≦ 0. 005, 0.96 ≦ c ≦ 1.06, 1.98 ≦ a + b + c ≦ 2.02)
An organopolysiloxane having a viscosity at 25 ° C. of not less than 10,000 mPa · s: 100 parts by mass (B) Silica-based filler: 2 to 100 parts by mass (C) The following formulas (2) and (3)

An organohydrogenpolysiloxane having at least one siloxane unit represented by the formula: 0.1 to 30 parts by mass (D) an organic peroxide vulcanizing agent: a catalyst amount, A fluorosilicone rubber composition for bonding with dimethyl silicone rubber .
[Claim 2]
The organohydrogenpolysiloxane of component (C) is represented by the following formula (4), (5) or (6)

The fluorosilicone rubber composition according to claim 1, which has at least one siloxane unit represented by the formula:
[Claim 3]
The organohydrogenpolysiloxane of component (C) is represented by the following formula (7)

The fluorosilicone rubber composition according to claim 1, wherein at least one siloxane unit represented by the formula:
[Claim 4]
A laminate of fluorosilicone rubber and dimethylsilicone rubber, characterized in that the fluorosilicone rubber comprises a cured product of the fluorosilicone rubber composition according to any one of claims 1 to 3.

  The cured product of the fluorosilicone rubber composition of the present invention is excellent in adhesion to the dimethyl silicone interface even when the pressure during molding such as press vulcanization, further steam vulcanization, and normal pressure hot air vulcanization is low, It can be used as a turbo hose material molded in a two-layer structure with dimethyl silicone rubber, especially for automobiles. In addition, the compatibility with the dimethyl silicone rubber composition is superior to that of a normal fluorosilicone rubber composition, so that it can be used in blends with the dimethyl silicone rubber composition without causing delamination. .

The organopolysiloxane of component (A) has the following average composition formula (1)
R ¹ _a R ² _b R ³ _c SiO _{(4-abc) / 2} (1)
It is represented by Here, R ¹ is a trifluoropropyl group, and the fluorine atom may be bonded to any carbon atom at the 1st to 3rd positions, but typically a 3,3,3-trifluoropropyl group is used. . R ² is an unsubstituted or substituted monovalent aliphatic unsaturated hydrocarbon group having 2 to 8 carbon atoms, preferably 2 to 4 carbon atoms, particularly a hydrocarbon group having an aliphatic unsaturated double bond, a vinyl group, Examples include an alkenyl group such as an allyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a hexenyl group, and a cyclohexenyl group, and a vinyl group is particularly preferable. R ³ is an unsubstituted monovalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 8 carbon atoms, specifically, a methyl group, an ethyl group, or a propyl group. , An isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, an hexyl group, a cyclohexyl group, an alkyl group such as an octyl group, an aryl group such as a phenyl group and a tolyl group, and an aralkyl group such as a benzyl group. a, b, and c are positive numbers, a is 0.96 to 1.01, b is 0.0001 to 0.005, c is 0.96 to 1.06, and a + b + c is 1.98 to 2.02. Preferably, a is 0.98 to 1.01, b is 0.0005 to 0.005, c is 0.98 to 1.01, and a + b + c is 1.99 to 2.01. Is a positive number satisfying.

In this organopolysiloxane, it is necessary to have at least two aliphatic unsaturated hydrocarbon groups such as alkenyl groups as R ² in the molecule (usually 2 to 50, preferably about 2 to 20). , and the addition is preferably about 0.02 to 1 mole percent of the sum of R ¹ to R ^3. When the alkenyl group as R ² is more than 1 mol%, there may be a problem that the rubber hardness increases more than practical or becomes brittle and mechanical strength such as tensile strength and tear strength is lowered. Even if the monovalent aliphatic unsaturated hydrocarbon group of R ² is present at the end of the molecular chain (ie, bonded to the silicon atom at the end of the molecular chain), it is present in the side chain of the molecule (ie, Or those existing at both the terminal and the side chain. The organopolysiloxane of component (A) may or may not contain a hydroxyl group as R ³ , and when it contains a hydroxyl group, the amount of R ³ that is a hydroxyl group is usually 0.001 to 10 mol% of the total R ³ , Preferably it is about 0.02 to 2 mol%.

  The organopolysiloxane preferably has a viscosity at 25 ° C. of 10,000 mPa · s or more. More preferably, it is 100,000 to 100,000,000 mPa · s, and particularly preferably, the lower limit of the viscosity is 1,000,000 mPa · s or more, especially 10,000,000 mPa · s or more, and room temperature ( It is a so-called raw rubber that does not have self-fluidity at 25 ° C. This viscosity value is a value measured by a rotational viscometer.

  The polymerization degree of the component (A) (that is, the number of diorganosiloxane units constituting the main chain) is preferably 500 or more, more preferably 1,000 or more, as a weight average polymerization degree. The upper limit of the degree of polymerization is not particularly limited, but the weight average degree of polymerization may be, for example, 100,000 or less, preferably about 10,000 or less. In addition, a weight average polymerization degree can be calculated | required as a polystyrene conversion value by a gel permeation chromatography (GPC) analysis.

  The organopolysiloxane (A) is composed of repeating diorganosiloxane units in the main chain, and both ends of the molecular chain are blocked with silanol groups (that is, hydroxyl groups in the hydroxydiorganosiloxy group) or triorganosiloxy groups. It is generally a straight-chain diorganopolysiloxane.

As a specific example of the component (A),
Both ends vinyldimethylsiloxy group-blocked methyltrifluoropropylpolysiloxane,
Silanol group-blocked methyl trifluoropropyl siloxane / methyl vinyl siloxane copolymer,
Both end trimethylsiloxy group-blocked methyltrifluoropropylsiloxane / methylvinylsiloxane copolymer,
Both ends vinyldimethylsiloxy group-blocked methyltrifluoropropylsiloxane / methylvinylsiloxane copolymer,
Both ends vinyl dimethyl siloxy group blocked methyl trifluoropropyl siloxane / methyl vinyl siloxane / methyl phenyl siloxane copolymer,
Both ends vinyldimethylsiloxy group-blocked methyltrifluoropropylsiloxane / methylvinylsiloxane / diphenylsiloxane copolymer,
One-end vinyldimethylsiloxy group-blocked, one-end silanol group-blocked methyltrifluoropropylpolysiloxane,
One-end vinyldimethylsiloxy group-blocked, one-end silanol group-blocked methyltrifluoropropylsiloxane / methylvinylsiloxane copolymer,
One-end vinyldimethylsiloxy group-blocked, one-end silanol group-blocked methyltrifluoropropylsiloxane / diphenylsiloxane copolymer,
One-end vinyldimethylsiloxy group-blocked, one-end silanol group-blocked methyltrifluoropropylsiloxane / methylphenylsiloxane copolymer,
Both ends trimethylsiloxy group-blocked methyltrifluoropropylsiloxane / methylvinylsiloxane / methylphenylsiloxane copolymer,
Both ends trimethylsiloxy group blocked methyltrifluoropropylsiloxane / methylvinylsiloxane / diphenylsiloxane copolymer,
Silanol group-blocked methyl trifluoropropyl siloxane / methyl vinyl siloxane / methyl phenyl siloxane copolymer,
Silanol group-blocked methyl trifluoropropyl siloxane / methyl vinyl siloxane / diphenyl siloxane copolymer,
One-end vinyldimethylsiloxy group-blocked and one-end silanol group-blocked methyltrifluoropropylsiloxane / methylvinylsiloxane / methylphenylsiloxane copolymer,
Examples thereof include one-end vinyldimethylsiloxy group-blocked and one-end silanol group-blocked methyltrifluoropropylsiloxane / methylvinylsiloxane / diphenylsiloxane copolymer.

で示されるシロキサンオリゴマーを開始剤として、トリ（トリフロロプロピル）トリメチルシクロトリシロキサンを開環重合することにより製造することができる。 The organopolysiloxane represented by the general formula (1) is represented by the following formula (9) as described in, for example, JP-A-62-174260.

Can be produced by ring-opening polymerization of tri (trifluoropropyl) trimethylcyclotrisiloxane using the siloxane oligomer represented by

The silica-based filler (B) is essential for obtaining a silicone rubber compound with excellent mechanical strength (reinforcing filler). For this purpose, the BET specific surface area is 50 m. ² / g or more, preferably 100 to 400 m ² / g. Examples of the silica filler include fumed silica (dry silica), calcined silica, and precipitated silica (wet silica). Further, these surfaces may be hydrophobized with organopolysiloxane, organopolysilazane, chlorosilane, alkoxysilane, or the like. These silicas may be used alone or in combination of two or more. The amount of the silica filler added is less than 2 parts by mass with respect to 100 parts by mass of the organopolysiloxane of the component (A), so that a sufficient reinforcing effect cannot be obtained. Since the physical properties of the resulting silicone rubber are deteriorated, it is 2 to 100 parts by mass, preferably 5 to 60 parts by mass.

  The organohydrogenpolysiloxane of component (C) is the most important component for developing adhesiveness with the dimethylsilicone interface, and is a unit represented by the following formulas (2) and (3) (bifunctional siloxane unit) ) In each molecule, preferably 2 or more (for example, 2 to 100), more preferably about 3 to 50.

で示される部分が存在するため、フロロシリコーン界面においてジメチルシリコーンとの親和性が大きくなる。特にプレス加硫等、ある一定圧を成型時にかけられる成型方法では、界面が共加硫することで強密着となり、界面での剥離は起こりにくくなる。しかしながら、ホース材を成型するには、スチーム加硫、常圧熱気加硫の方が適しているため、本物質はこの様な成型時の圧力が低い場合にも、界面での剥離を起こりにくくさせ、より効果的である。分子の大きさは２５℃における粘度が２，０００ｍＰａ・ｓ以下となるものが好ましい。これより大きくなると、コンパウンドに添加した場合の分散性が悪くなったり、表面に優先的に一方の官能基を有した部分が存在しなくなることで、界面の接着性に効果を発現しにくくなる。 The siloxane unit represented by the above formula (2) (methyltrifluoropropylsiloxane unit) increases the affinity with fluorosilicone, and the siloxane unit represented by formula (3) (methylhydrogensiloxane unit) has an affinity with dimethylsilicone. Acts to enhance sex. Therefore, by adding the component (C) to the fluorosilicone, the following formula (3) is preferentially given to the interface.

Therefore, the affinity with dimethyl silicone is increased at the fluorosilicone interface. In particular, in a molding method in which a certain pressure is applied during molding, such as press vulcanization, the interface is co-vulcanized to provide strong adhesion, and peeling at the interface is less likely to occur. However, since steam vulcanization and normal pressure hot air vulcanization are more suitable for molding hose materials, this material is less likely to delaminate at the interface even when such molding pressure is low. Let it be more effective. The molecular size is preferably such that the viscosity at 25 ° C. is 2,000 mPa · s or less. If it is larger than this, the dispersibility when added to the compound is deteriorated, or the portion having one functional group preferentially on the surface does not exist, so that it is difficult to exert an effect on the adhesiveness at the interface.

  The mol% of the trifluoropropyl group-containing siloxane unit represented by the formula (2) in the molecule (that is, the ratio to the total siloxane units in the molecule, the same applies hereinafter) is preferably 1 to 90 mol%, more preferably 5 to 80. Mol%. If it is less than 1 mol%, it may be difficult to exert an effect on the adhesiveness, and if it exceeds 90 mol%, it may be difficult to obtain adhesiveness. Moreover, the ratio in the molecule | numerator of the hydrogen siloxane unit shown by Formula (3) becomes like this. Preferably it is 1-90 mol%, More preferably, it is 5-80 mol%. If this is also less than 1 mol%, there is a possibility that the effect on the adhesiveness is difficult to be obtained, and if it exceeds 90 mol%, the adhesiveness may be difficult to be obtained. Furthermore, as means for improving adhesiveness, the monofunctional siloxane unit (vinyldimethylsiloxy unit, divinylmethylsiloxy unit or trivinylsiloxy unit) of the following formula (4), (5) or (6), or the following formula ( Introducing the bifunctional siloxane unit (vinylmethylsiloxane unit) of 7) into the molecule and containing a predetermined amount of vinyl groups is also effective in improving the adhesiveness.

このビニル基は、フロロシリコーンゴム或いはジメチルシリコーンゴムの架橋の中に取り込まれることでより接着性を高める。

This vinyl group enhances adhesion by being incorporated into the crosslinks of fluorosilicone rubber or dimethylsilicone rubber.

  As the organohydrogenpolysiloxane of component (C), both molecular chain ends are typically blocked with a triorganosiloxy group such as a trimethylsiloxy group, a vinyldimethylsiloxy group, a divinylmethylsiloxy group, or a trivinylsiloxy group. The main chain portion composed of repeating bifunctional siloxane units is a combination of methyl trifluoropropyl siloxane units and methyl hydrogen siloxane units, or methyl trifluoropropyl siloxane units, methyl hydrogen siloxane units and vinyl methyl. A linear siloxane copolymer composed of a combination with siloxane units may be mentioned. Moreover, these siloxane copolymers are suitably used if the number of silicon atoms (or degree of polymerization) in one molecule is 4 to 200, preferably 8 to 100, more preferably about 20 to 100. Can be used.

  The organic peroxide vulcanizing agent (D) is added to the fluorosilicone rubber composition component and vulcanized and cured by a conventional method to give a cured product. Specifically, benzoyl peroxide, tertiary butyl perbenzoate, orthomethyl benzoyl peroxide, paramethyl benzoyl peroxide, ditertiary butyl peroxide, dicumyl peroxide, 1,1-bis (tertiary butyl peroxy) 3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di (tertiary butyl peroxy) hexane, 2,5-dimethyl-2,5-di (tertiary butyl peroxy) hexyne Etc. These may be used alone or in combination of two or more. The amount of the organic peroxide is preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the fluorosilicone rubber composition.

  The fluorosilicone rubber composition of the present invention includes non-reinforcing silica such as pulverized quartz and diatomaceous earth, carbon black such as acetylene black, furnace black, and channel black, fillers such as calcium carbonate, colorants, and heat resistance as necessary. Additives such as improver, flame retardant improver, acid acceptor, heat conduction improver, release agent, dispersant such as alkoxysilane, diphenylsilanediol, carbon functional silane, both-end silanol-capped low molecular weight siloxane, etc. May be added.

  Furthermore, in the present invention, a known alkoxysilane having a functional group effective for adhesion such as acryloxy group, methacryloxy group, 3-aminopropyl group, N-2 (aminoethyl) 3-aminopropyl group, epoxy group, etc. is added. You may do it.

  The fluorosilicone rubber composition for obtaining the fluorosilicone rubber molding of the present invention is obtained by uniformly mixing the above-described components using a rubber kneader such as a two-roll, Banbury mixer, or dough mixer (kneader). Can be obtained.

  There is no particular limitation on the molding method of the fluorosilicone rubber composition, and it can be molded into a desired shape in accordance with general rubber molding methods such as compression molding, transfer molding, injection molding, extrusion molding, calendar molding, etc., O-ring, diaphragm , Rubber molded products such as packings and gaskets. In this case, a vulcanization method such as steam vulcanization or normal pressure hot air vulcanization by extrusion molding or calendar molding is suitable for the molding method of the present invention. Moreover, you may carry out secondary vulcanization at 180-250 degreeC for about 1 to 10 hours as needed.

  In this case, the fluorosilicone rubber composition of the present invention can form a fluorosilicone rubber that gives good adhesion to the dimethylsilicone rubber when the dimethylsilicone rubber composition is laminated and vulcanized. It is suitably used for forming a laminated structure of silicone rubber and fluorosilicone rubber.

  Here, as the dimethyl silicone rubber composition, for example, an alkenyl group-containing dimethylpolysiloxane is used as a main agent (base polymer), and a silica-based inorganic filler (reinforcing filler) and an organic peroxide (curing catalyst) are contained. Organic peroxide curable dimethyl silicone rubber composition, alkenyl group-containing dimethylpolysiloxane (base polymer), silica-based inorganic filler (reinforcing filler), organohydrogenpolysiloxane (crosslinking agent) such as methylhydrogenpolysiloxane ), An addition reaction curable dimethyl silicone rubber composition containing a platinum group metal catalyst (hydrosilylation catalyst) and the like, and particularly when an organic catalyst is laminated and vulcanized with the fluorosilicone rubber composition of the present invention. An oxide curable dimethyl silicone rubber composition is effective.

  In addition, as a method for obtaining a laminated structure (laminate) of dimethyl silicone rubber and fluorosilicone rubber, for example, each of dimethylsilicone rubber composition and fluorosilicone rubber composition is dispensed into a sheet shape with a calender roll, Next, a method of laminating and winding on a mandrel and steam vulcanization or atmospheric pressure hot air vulcanization (HAV) can be mentioned. Alternatively, the above composition can be stacked and charged (filled) in a mold for molding, and then compression molded. The vulcanization conditions are 100 to 200 ° C. for 10 minutes to 2 hours in the case of steam vulcanization, 10 seconds to 1 hour at 150 to 500 ° C. in the case of atmospheric pressure hot air vulcanization (HAV), and 100 in the case of compression molding. Can be about 1 minute to 1 hour at ~ 200 ° C,

  The thicknesses of the dimethyl silicone rubber layer and the fluorosilicone rubber layer are not particularly limited, and any thickness can be adopted as appropriate according to the use of the laminated structure. In general, each layer has a thickness in the range of 0.1 to 10 cm.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.

（式中、ｐ＋ｑ（即ち、重合度）は約４，０００であり、ｑ／（ｐ＋ｑ）（即ち、全シロキサン単位に対するビニル基含有シロキサン単位）の割合は０．３±０．０５モル％である。）
で示される室温（２５℃）において生ゴム状のオルガノポリシロキサンＡを１００質量部、乾式シリカＡ（日本アエロジル（株）製、商品名：アエロジル２００）２０質量部、及び分散剤としてジフェニルシランジオール４質量部を加えて均一に混練りし、１５０℃で４時間熱処理した後、２本ロールで釈解、可塑化し、ベースコンパウンドＡを得た。 (Examples 1-4, Comparative Examples 1-5)
First, a base compound was produced by the following method.
Base compound A :
Following formula (10)

(Wherein p + q (that is, degree of polymerization) is about 4,000, and the ratio of q / (p + q) (that is, vinyl group-containing siloxane unit to all siloxane units) is 0.3 ± 0.05 mol%. is there.)
100 parts by mass of raw rubber-like organopolysiloxane A at room temperature (25 ° C.), 20 parts by mass of dry silica A (manufactured by Nippon Aerosil Co., Ltd., trade name: Aerosil 200), and diphenylsilanediol 4 as a dispersant After adding a mass part, it knead | mixed uniformly, and heat-processed at 150 degreeC for 4 hours, Then, it melt | dissolved and plasticized with 2 rolls, and the base compound A was obtained.

Base compound B :
100 parts by mass of organopolysiloxane A represented by the above formula (10), 25 parts by mass of dry silica A (manufactured by Nippon Aerosil Co., Ltd., trade name: Aerosil 200), and 6 parts by mass of diphenylsilanediol as a dispersant are added. The mixture was kneaded uniformly and heat-treated at 150 ° C. for 4 hours.

  Next, the base compounds A and B were mixed with the following various organo (hydrogen) polysiloxanes in two rolls in the amounts shown in Tables 1 and 2.

Organohydrogenpolysiloxane 1

Organohydrogenpolysiloxane 2

Organohydrogenpolysiloxane 3

Organohydrogenpolysiloxane 4

Organopolysiloxane 5

About these formulations, the initial physical property and adhesiveness test were done by the following method.
Initial physical properties : 100 parts by mass of the above compound and 0.8 parts by mass of a paste containing 80% 2,5-dimethyl-2,5-di (tertiary butyl peroxy) hexane in two rolls to form a fluorosilicone rubber composition A product was prepared. After performing pressure molding at 165 ° C. for 10 minutes for measurement of physical properties, post-curing was performed at 200 ° C. for 4 hours to prepare a 2 mm thick sheet. The measurement method conformed to JIS K6249.

Adhesion test : A vulcanizing agent is blended in the blended organohydrogenpolysiloxane by the following method, and this is separated into strips of 1.0 to 1.2 mm thickness and 25 mm x 175 mm with two rolls. On the fluorosilicone rubber composition, a 0.2 mm thick, 25 mm × 90 mm Teflon (polytetrafluoroethylene resin) sheet is placed with one end aligned, and further 1.0 to 1.2 mm thick, The following dimethyl silicone rubber composition dispensed into 25 mm × 175 mm strips was placed. This was press vulcanized under the molding conditions shown in Tables 1 and 2 to obtain a laminate (test piece) having a two-layer structure of fluorosilicone rubber and dimethylsilicone rubber. The obtained test piece is divided into a fluorosilicone rubber layer and a dimethylsilicone rubber layer through the sheet, so that the fluorosilicone rubber part and the dimethylsilicone rubber part are fixed and at a constant speed of 50 mm / min in both directions. The strength when pulled was defined as the adhesive strength.

  The vulcanizing agent was blended using a paste containing 80% 2,5-dimethyl-2,5-di (tertiary butyl peroxy) hexane at a ratio of 0.8 part by mass with respect to 100 parts by mass of the fluorosilicone compound. This was blended with two rolls.

(Dimethyl silicone rubber composition)
A dimethyl silicone compound (compound C) comprising a dimethylsiloxane unit as a main component, a methyl vinylsiloxane unit, a rubber-like material having an average degree of polymerization of about 5,000, comprising about 0.11 mol% of vinyl derived from the dimethylvinylsiloxane unit. To 100 parts by mass of organopolysiloxane, 5 parts by mass of methoxysilane and 2 parts by mass of dimethylpolysiloxane as a dispersant, 35 parts by mass of dry silica (manufactured by Nippon Aerosil Co., Ltd., trade name: Aerosil 200) as a filler, It was obtained by heat treatment at 170 ° C. for 2 hours. To 100 parts by mass of this compound C, 0.6 parts by mass of a paste containing 80% 2,5-dimethyl-2,5-di (tertiary butyl peroxy) hexane is blended in two rolls, and a dimethyl silicone rubber composition is prepared. Obtained.

  In Tables 1 and 2, the state of peeling: ○ indicates partial cohesive failure, ◎ indicates all cohesive failure (both ○ and ◎ have good adhesion), and x indicates interfacial peeling (poor adhesion).

  From the results of Tables 1 and 2, the fluorosilicone rubber composition of the present invention does not contain the component (C) of the present invention under the same molding conditions when co-vulcanized with the dimethylsilicone rubber composition. It was confirmed that a fluorosilicone rubber composition that gives a fluorosilicone rubber having an adhesive strength at least twice that of the composition and having good adhesion at the interface with dimethylsilicone rubber can be provided.

Claims (4)

(A) The following average composition formula (1)
R ¹ _a R ² _b R ³ _c SiO _{(4-abc) / 2} (1)
(In the formula, R ¹ is a trifluoropropyl group, R ² is an unsubstituted or substituted monovalent aliphatic unsaturated hydrocarbon group having 2 to 8 carbon atoms, R ³ is a hydroxyl group, and an unsubstituted one having 1 to 8 carbon atoms. A monovalent aliphatic saturated hydrocarbon group or a monovalent aromatic hydrocarbon group having 6 to 8 carbon atoms, a, b and c are 0.96 ≦ a ≦ 1.01, 0.0001 ≦ b ≦ 0. 005, 0.96 ≦ c ≦ 1.06, 1.98 ≦ a + b + c ≦ 2.02)
An organopolysiloxane having a viscosity at 25 ° C. of not less than 10,000 mPa · s: 100 parts by mass (B) Silica-based filler: 2 to 100 parts by mass (C) The following formulas (2) and (3)

An organohydrogenpolysiloxane having at least one siloxane unit represented by the formula: 0.1 to 30 parts by mass (D) an organic peroxide vulcanizing agent: a catalyst amount, A fluorosilicone rubber composition for bonding with dimethyl silicone rubber . Component (C) is an organohydrogenpolysiloxane having the following formula (4), (5) or (6):

The fluorosilicone rubber composition according to claim 1, which has at least one siloxane unit represented by the formula: The organohydrogenpolysiloxane of component (C) is represented by the following formula (7)

The fluorosilicone rubber composition according to claim 1, wherein at least one siloxane unit represented by the formula:   A laminate of fluorosilicone rubber and dimethylsilicone rubber, characterized in that the fluorosilicone rubber comprises a cured product of the fluorosilicone rubber composition according to any one of claims 1 to 3.