JP2013103963A - Organosilicone rubber composition, and laminate of organosilicone rubber and fluorosilicone rubber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organosilicone rubber composition excellent in adhesiveness between a silicone rubber composition and a fluorosilicone rubber composition, and a laminate (laminated structure) of an organosilicone rubber comprising a cured product of the organosilicone rubber composition and fluorosilicone rubber.SOLUTION: This organosilicone rubber composition includes: (A) 100 pts.mass of an organopolysiloxane expressed by average composition formula (1): RSiO(where Rs are each the same or different non-substituted or cyano-substituted monovalent hydrocarbon group; a is a positive number of 1.90-2.05); (B) 2-100 pts.mass of a silica-based filler; (C) 0.01-30 pts.mass of a specific organohydrogenpolysiloxane having at least one each of a siloxane unit containing a fluoroalkyl group and a siloxane unit containing a hydrogen group in one molecule; and (D) a catalytic amount of an organic peroxide vulcanizing agent.

Description

  The present invention relates to a silicone rubber composition comprising a non-fluorinated organopolysiloxane that does not contain a fluorine-substituted hydrocarbon group (fluorocarbon) in the molecule as a monovalent hydrocarbon group bonded to a silicon atom (that is, a fluorocarbon). Non-fluorinated silicone rubber composition comprising a base polymer containing no silicone, and particularly a silicone rubber composition that provides silicone rubber such as dimethyl silicone rubber excellent in adhesion to fluorosilicone rubber, and the silicone rubber composition The present invention relates to a laminate of silicone rubber and fluorosilicone rubber made of a cured product.

  In order to distinguish from a fluorosilicone rubber composition and its cured product (fluorosilicone rubber), a silicone rubber composition using a non-fluorinated organopolysiloxane containing no fluorine-substituted hydrocarbon group (fluorocarbon) as a base polymer. The cured product (silicone rubber) is hereinafter referred to as “organosilicone rubber composition” or “organosilicone rubber”.

  Fluorosilicone rubber (that is, a rubber-like cured product having fluorosilicone as a base polymer in which the difunctional diorganosiloxane unit constituting the main chain is composed of repeating 3,3,3-trifluoropropylmethylsiloxane units) It is excellent in heat resistance, cold resistance, oil resistance, fuel oil resistance, compression resilience, and the like, and is widely used as a transportation equipment part for automobiles, airplanes, etc. and a part for petroleum shipping equipment. When used as a material for automobiles, particularly as a turbo hose, there is an example in which it is molded with a two-layer structure of dimethyl silicone rubber and fluorosilicone rubber. 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, it is foreseen that the adhesion at the interface will be very poor and easy to peel.

（式中、Ｒ⁴は炭素数２〜８の非置換又は置換の１価脂肪族不飽和炭化水素基、炭素数１〜８の非置換の１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. Moreover, even if an organohydrogenpolysiloxane mainly having a methyl group recommended in this publication is added to a dimethyl silicone rubber composition, a sufficient effect cannot be obtained by adhesion to the fluorosilicone rubber.

JP 2006-328303 A JP 2008-156564 A

  The present invention has been made in view of the above circumstances, and when the silicone rubber composition such as a dimethyl silicone rubber composition and the fluorosilicone rubber composition are laminated and vulcanized, the present invention has excellent adhesion to the fluorosilicone rubber interface. An object of the present invention is to provide an organosilicone rubber composition that gives silicone rubber, and a laminate (laminated structure) of an organosilicone rubber such as dimethyl silicone rubber and a fluorosilicone rubber, which is a cured product of the organosilicone rubber composition. To do.

  As a result of intensive studies to achieve the above object, the present inventor has added 0.1 to 30 parts by mass of an organohydrogenpolysiloxane having a trifluoropropyl group in the molecule, such as a dimethyl silicone rubber composition. It has been found that by adding to the composition, the organosilicone rubber composition is excellent in adhesion at the interface when co-vulcanized with the fluorosilicone rubber composition. In this case, when the molded product obtained by curing the fluorosilicone rubber composition is used as a material for automobiles, particularly turbo hoses, a two-layer structure of an organosilicone rubber layer such as dimethylsilicone rubber and a fluorosilicone rubber layer It was found that it was very difficult to peel off at the organosilicone rubber layer / fluorosilicone rubber layer interface, and was excellent in adhesion to fluorosilicone rubber, and the present invention was made.

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：０．０１〜３０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オルガノシリコーンゴム組成物。
<２> 平均組成式（１）のＲが炭素数１〜１０の、アルキル基、アルケニル基又はアリール基である<１>記載のオルガノシリコーンゴム組成物。
<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（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<１>又は<２>記載のオルガノシリコーンゴム組成物。
<４> （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<１>〜<３>のいずれかに記載のオルガノシリコーンゴム組成物。
<５> <１>〜<４>のいずれかに記載のオルガノシリコーンゴム組成物の硬化物であるシリコーンゴムとフロロシリコーンゴムとの積層体。
<６> フロロシリコーンゴムが、２官能性ジオルガノシロキサン単位としてトリフルオロプロピルメチルシロキサン単位とビニルメチルシロキサン単位の繰り返しからなるアルケニル基含有メチルトリフルオロプロピルポリシロキサンとシリカ系充填剤と上記ポリシロキサンの硬化剤とを含有してなるフロロシリコーンゴム組成物の硬化物である<５>記載のシリコーンゴムとフロロシリコーンゴムとの積層体。
<７> <１>〜<４>のいずれかに記載のオルガノシリコーンゴム組成物と、<６>記載のフロロシリコーンゴム組成物とを積層し、スチーム加硫もしくは常圧熱気加硫又はプレス加硫により上記両組成物をそれぞれ硬化することを特徴とするシリコーンゴムとフロロシリコーンゴムとの積層体の製造方法。 Accordingly, the present invention provides the following organosilicone rubber composition, a laminate of an organosilicone rubber and a fluorosilicone rubber comprising a cured product of the organosilicone rubber composition, and a method for producing the same.
<1> (A) The following average composition formula (1)
R _a SiO _{(4-a) / 2} (1)
(In the formula, R is the same or different unsubstituted or cyano-substituted monovalent hydrocarbon group, and a is a positive number of 1.90 to 2.05.)
An organopolysiloxane represented by: 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: 0.01 to 30 parts by mass,
(D) Organic peroxide vulcanizing agent: An organosilicone rubber composition comprising a catalytic amount.
<2> The organosilicone rubber composition according to <1>, wherein R in the average composition formula (1) is an alkyl group, alkenyl group or aryl group having 1 to 10 carbon atoms.
<3> The organohydrogenpolysiloxane of component (C) is represented by the following formula (4), (5) or (6)

The organosilicone rubber composition according to <1> or <2>, wherein the organosilicone rubber composition has at least one siloxane unit represented by the formula:
<4> The organohydrogenpolysiloxane of component (C) is represented by the following formula (7)

The organosilicone rubber composition according to any one of <1> to <3>, having at least one siloxane unit represented by
<5> A laminate of silicone rubber and fluorosilicone rubber, which is a cured product of the organosilicone rubber composition according to any one of <1> to <4>.
<6> A fluorosilicone rubber comprising an alkenyl group-containing methyl trifluoropropyl polysiloxane composed of a repeating trifluoropropylmethylsiloxane unit and a vinylmethylsiloxane unit as a bifunctional diorganosiloxane unit, a silica-based filler, and the above polysiloxane. A laminate of the silicone rubber and the fluorosilicone rubber according to <5>, which is a cured product of a fluorosilicone rubber composition containing a curing agent.
<7> The organosilicone rubber composition according to any one of <1> to <4> and the fluorosilicone rubber composition according to <6> are laminated, and steam vulcanization, normal pressure hot air vulcanization, or press vulcanization is performed. A method for producing a laminate of a silicone rubber and a fluorosilicone rubber, characterized in that each of the two compositions is cured by sulfur.

  The cured product of the organosilicone rubber composition of the present invention is excellent in adhesion to the fluorosilicone 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 material for automobiles, in particular, a turbo hose molded with a two-layer structure with fluorosilicone rubber. In addition, since the compatibility with the fluorosilicone rubber composition is superior to that of a normal organosilicone rubber composition, it can also be used in blends with a fluorosilicone rubber composition without causing delamination. .

The organopolysiloxane of component (A) has the following average composition formula (1)
R _a SiO _{(4-a) / 2} (1)
As a monovalent hydrocarbon group R bonded to a silicon atom represented by the formula (1), it is a non-fluorinated organopolysiloxane that does not contain a fluorine-substituted hydrocarbon group (fluorocarbon) in the molecule. Here, R is an alkyl group such as a methyl group, an ethyl group, a propyl group, or a butyl group, a cycloalkyl group such as a cyclohexyl group, an alkenyl group such as a vinyl group, an allyl group, a butenyl group, or a hexenyl group, a phenyl group, or a tolyl group. Aryl groups such as the above, or the same or different, preferably 1 to 10 carbon atoms, more preferably selected from a cyanoethyl group or the like in which part or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with a cyano group Is an unsubstituted or cyano-substituted monovalent hydrocarbon group having 1 to 8 carbon atoms. In this case, R preferably has at least two aliphatic unsaturated groups (alkenyl groups), and the content of aliphatic unsaturated groups (alkenyl groups) in R is 0.001 to 20 mol%, In particular, it is preferably 0.025 to 5 mol%. Further, 80 mol% or more (80 to 99.999 mol%) of all R groups, particularly 95 mol% or more (95 to 99.975 mol%), especially all R groups other than alkenyl groups are alkyl groups, particularly methyl groups. It is desirable to be a group. A is a positive number of 1.90 to 2.05, preferably 1.95 to 2.02.

  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. The viscosity in the present invention can be measured by, for example, a rotational viscometer (BL type, BH type, BS type cone plate type, etc.).

  The degree of polymerization of the component (A) (that is, the number of diorganosiloxane units constituting the main chain or the number of silicon atoms in the molecule) is preferably 500 or more, more preferably 1 as the weight average degree of polymerization. 1,000 or more. 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 by calculating from the polystyrene conversion value by a gel permeation chromatography (GPC) analysis, for example using toluene as a developing solvent.

  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),
Molecular chain both ends vinyldimethylsiloxy group-blocked dimethylpolysiloxane,
Dimethylmethylsiloxy group-blocked dimethylpolysiloxane with both molecular chain ends,
Molecular chain both ends trivinylsiloxy group blocked dimethylpolysiloxane,
Silanol group-blocked dimethylsiloxane / methylvinylsiloxane copolymer with both molecular chains
Molecular chain both ends vinyldimethylsiloxy group-blocked dimethylsiloxane / methylvinylsiloxane copolymer,
Dimethylsiloxane / methylvinylsiloxane / methylphenylsiloxane copolymer blocked with vinyldimethylsiloxy group at both ends of the molecular chain,
Examples thereof include vinyldimethylsiloxy group-blocked dimethylsiloxane / methylvinylsiloxane / diphenylsiloxane copolymer with both ends of the molecular chain.

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 (fumed silica or 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 an interface between the organosilicone rubber and the fluorosilicone rubber obtained by curing the organosilicone rubber composition of the present invention (that is, a bifunctional diorganosiloxane constituting the main chain). It is the most important component for expressing the adhesiveness of a rubber-like cured product having fluorosilicone as a base polymer) in which the unit is composed of repeating 3,3,3-trifluoropropylmethylsiloxane units. And at least one unit (bifunctional siloxane unit) represented by (3), preferably 2 or more (for example, 2 to 100), more preferably about 3 to 50, in each molecule. Is.

で示される部分が存在するため、オルガノシリコーンゴム界面においてフロロシリコーンゴムとの親和性が大きくなる。特にプレス加硫等、ある一定圧を成形時にかけられる成形方法では、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、ホース材を成形するには、スチーム加硫、常圧熱気加硫の方が適しているため、本物質はこのような成形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 organosilicone rubber composition, the following formula (2)

Therefore, the affinity with the fluorosilicone rubber is increased at the organosilicone rubber interface. In particular, in a molding method such as press vulcanization in which a certain pressure is applied at the time of molding, 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 forming hose materials, this substance is less likely to peel off at the interface even when the pressure during molding 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 mol% 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. In addition, it is preferable that content of the siloxane unit of following formula (7) is 0-20 mol%, especially 0-10 mol%.

  This vinyl group enhances adhesiveness by being incorporated into the crosslinks of organosilicone rubber or fluorosilicone 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. In addition, these siloxane copolymers have 4 to 200 silicon atoms (or polymerization degree) in one molecule, preferably 8 to 100, more preferably 15 to 100, and still more preferably 20 to 50. Any suitable material can be used.

  The organohydrogenpolysiloxane of component (C) can also be added to the fluorosilicone rubber composition side to further increase the adhesion between the organosilicone rubber / fluorosilicone rubber.

  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 organosilicone 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, filler such as calcium carbonate, colorant, heat resistance 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, an alkenyl group such as a vinyl group, an acryloxy group (3-acryloxypropyl group, etc.), a methacryloxy group (3-methacryloxypropyl group, etc.), a 3-aminopropyl group, N-2- (aminoethyl) ) -3-aminopropyl group, epoxy group (3-glycidoxypropyl group, 2- (2,3-epoxycyclohexyl) ethyl group, 2- (3,4-epoxycyclohexyl) ethyl group, etc.) In addition, a known alkoxysilane having a functional group effective for improving adhesiveness and / or a hydrolyzate thereof may be added.

  The organosilicone rubber composition for obtaining the organosilicone rubber molded product 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 organosilicone 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 calender 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 organosilicone rubber composition of the present invention can form an organosilicone rubber that gives good adhesion to the fluorosilicone rubber when the fluorosilicone rubber composition is laminated and vulcanized. It is suitably used for forming a laminated structure of silicone rubber and fluorosilicone rubber.

  Here, as the fluorosilicone rubber composition, an alkenyl group-containing methyl trifluoropropyl polysiloxane composed of repetition of a trifluoropropylmethylsiloxane unit and a vinylmethylsiloxane unit as a bifunctional diorganosiloxane unit, a silica-based filler, and the above-mentioned A fluorosilicone rubber composition containing a polysiloxane curing agent can be used. For example, trifluoropropylmethyl containing a small amount of vinylmethylsiloxane unit as a bifunctional diorganosiloxane unit constituting the main chain. Silica-based inorganic filler (reinforcement) consisting mainly of alkenyl group-containing methyl trifluoropropyl polysiloxane consisting of repeating siloxane units, both ends of which are blocked with silanol groups or triorganosiloxy groups Filler), organic peroxide curable fluorosilicone rubber composition containing organic peroxide (curing catalyst), alkenyl group-containing methyl trifluoropropyl polysiloxane (base polymer), silica-based inorganic filler as described above (Reinforcing filler), organohydrogenpolysiloxane (crosslinking agent) such as methylhydrogenpolysiloxane, addition reaction curable fluorosilicone rubber composition containing platinum group metal catalyst (hydrosilylation catalyst) In the case where the organosilicone rubber composition of the present invention is laminated and vulcanized, an organic peroxide curable fluorosilicone rubber composition is particularly effective.

  Examples of a method for obtaining a laminated structure (laminate) of an organosilicone rubber and a fluorosilicone rubber include, for example, an uncured (raw rubber-like) organosilicone rubber composition and an uncured (raw rubber-like) fluorosilicone rubber composition. Examples include a method in which each product is dispensed into a sheet form with a calender roll, then laminated and wound around a mandrel, and steam vulcanization or atmospheric pressure hot air vulcanization (HAV). As another method, the above composition can be stacked and charged (filled) in a mold for molding and 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. It can be about 1 minute to 1 hour at ~ 200 ° C.

  The thicknesses of the organosilicone 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.

[Examples 1-5, Comparative Examples 1-5]
First, a base compound was produced by the following method.
Base compound A :
(CH _{3) 2} SiO _2/2 units 99.85 _{mol%, (CH 3) (CH} 2 = CH) consists SiO _2/2 units 0.15 mol%, the molecular chain ends (CH ₂ = CH) ( A methyl vinyl polysiloxane raw rubber having a degree of polymerization of about 7,000 blocked with CH ₃ ) ₂ SiO _1/2 units was used. 100 parts by mass of this methyl vinyl polysiloxane raw rubber, 40 parts by mass of dry silica A (manufactured by Nippon Aerosil Co., Ltd., trade name: Aerosil 200), and dimethylpolysiloxane containing a hydroxyl group at the molecular chain terminal as a dispersant (degree of polymerization) 10) Add 10 parts by mass, knead uniformly, heat-treat at 150 ° C. for 2 hours, and then dissolve and plasticize with two rolls to obtain base compound A.

Base compound B :
It consists of 99.80 mol% of (CH ₃ ) ₂ SiO _2/2 units and 0.20 mol% of (CH ₃ ) (CH ₂ ═CH) SiO _2/2 units, and the molecular chain ends are (CH ₂ ═CH) ( A methyl vinyl polysiloxane raw rubber having a degree of polymerization of about 7,000 blocked with CH ₃ ) ₂ SiO _1/2 units was used. 100 parts by weight of this methyl vinyl polysiloxane raw rubber, 45 parts by weight of dry silica A (manufactured by Nippon Aerosil Co., Ltd., trade name: Aerosil 200), and dimethylpolysiloxane having a hydroxyl group at the molecular chain terminal as a dispersant (degree of polymerization) 10) Add 12 parts by mass, knead uniformly, heat-treat at 150 ° C. for 2 hours, and then dissolve and plasticize with two rolls to obtain base compound B.

  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 :
An organosilicone rubber composition is prepared by blending 0.5 parts by mass of a paste containing 80% by mass of 2,5-dimethyl-2,5-di (tertiary butyl peroxy) hexane with two rolls into 100 parts by mass of the above compound. 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 :
An organosilicone obtained by blending a vulcanizing agent into a blend of the above-described organohydrogenpolysiloxane by the following method, and dispensing the vulcanizing agent into a strip of 25 to 175 mm in a thickness of 1.0 to 1.2 mm using two rolls. On the rubber composition, a Teflon (registered trademark, polytetrafluoroethylene resin) sheet of 0.2 mm thickness and 25 mm × 90 mm is placed with one end aligned, and further 1.0 to 1.2 mm thick, 25 mm The following fluorosilicone rubber composition dispensed in a 175 mm strip 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 organosilicone rubber and fluorosilicone rubber. In the obtained test piece, the part through the sheet is divided into an organosilicone rubber layer and a fluorosilicone rubber layer, so the organosilicone rubber part and the fluorosilicone 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 is blended in an amount of 0.5 parts by mass of a paste containing 80% by mass of 2,5-dimethyl-2,5-di (tertiary butyl peroxy) hexane with respect to 100 parts by mass of the organosilicone compound. Used and blended in two rolls.

(Fluorosilicone rubber composition)
Base compound C
The bifunctional diorganosiloxane unit of the main chain is composed of methyltrifluoropropylsiloxane unit: 99.88 mol%, methylvinylsiloxane unit: 0.12 mol%, and both ends of the molecular chain are blocked with dimethylvinylsiloxy groups. Into 100 parts by mass of a raw rubber-like vinyl group-containing methyl trifluoropropylpolysiloxane having a vinyl group-containing siloxane unit content of about 0.15 mol% and an average degree of polymerization of about 5,000, a molecular chain terminal is used as a dispersant. 5 parts by mass of methyl trifluoropropylpolysiloxane containing a hydroxyl group (degree of polymerization 5) and 30 parts by mass of dry silica (manufactured by Nippon Aerosil Co., Ltd., trade name: Aerosil 200) as a filler are added at 150 ° C. Base compound C was obtained by heat treatment for a period of time.
The vulcanizing agent is blended in two rolls with 0.8 parts by mass of a paste containing 80% by mass of 2,5-dimethyl-2,5-di (tertiary butyl peroxy) hexane based on 100 parts by mass of the compound C. As a result, a fluorosilicone rubber composition was obtained.

  In Example 5 and Comparative Example 5, 1.0 part by mass of organohydrogensiloxane 3 was added to Compound C together with the vulcanizing agent (Table 3).

  In Tables 1, 2 and 3, the state of peeling: ○ indicates partial cohesive failure, ◎ indicates all cohesive failure (both ○ and ◎ have good adhesiveness), and x indicates interfacial peeling (poor adhesiveness).

  From the results of Tables 1, 2 and 3, the organosilicone 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 fluorosilicone rubber composition. It has been confirmed that an organosilicone rubber composition can be provided that gives an organosilicone rubber having an adhesive strength at least twice that of the organosilicone rubber composition and good adhesion at the interface with the fluorosilicone rubber.

  The cured product of the organosilicone rubber composition of the present invention is excellent in adhesion to the dimethylsilicone interface even when the molding pressure is low, such as steam vulcanization and atmospheric pressure hot air vulcanization. It can be used as a turbo hose material molded with a structure.

Claims (7)

(A) The following average composition formula (1)
R _a SiO _{(4-a) / 2} (1)
(In the formula, R is the same or different unsubstituted or cyano-substituted monovalent hydrocarbon group, and a is a positive number of 1.90 to 2.05.)
An organopolysiloxane represented by: 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: 0.01 to 30 parts by mass,
(D) Organic peroxide vulcanizing agent: An organosilicone rubber composition comprising a catalytic amount.   The organosilicone rubber composition according to claim 1, wherein R in the average composition formula (1) is an alkyl group, alkenyl group or aryl group having 1 to 10 carbon atoms. Component (C) is an organohydrogenpolysiloxane having the following formula (4), (5) or (6):

The organosilicone rubber composition according to claim 1 or 2, which has at least one siloxane unit represented by the formula: The organohydrogenpolysiloxane of component (C) is represented by the following formula (7)

The organosilicone rubber composition according to any one of claims 1 to 3, which has at least one siloxane unit represented by the formula:   A laminate of silicone rubber and fluorosilicone rubber, which is a cured product of the organosilicone rubber composition according to any one of claims 1 to 4.   Fluorosilicone rubber is an alkenyl group-containing methyltrifluoropropylpolysiloxane composed of repeating trifluoropropylmethylsiloxane units and vinylmethylsiloxane units as bifunctional diorganosiloxane units, a silica-based filler, and a curing agent for the polysiloxane. The laminate of a silicone rubber and a fluorosilicone rubber according to claim 5, which is a cured product of a fluorosilicone rubber composition containing   The organosilicone rubber composition according to any one of claims 1 to 4 and the fluorosilicone rubber composition according to claim 6 are laminated, and the both are obtained by steam vulcanization, atmospheric pressure hot air vulcanization, or press vulcanization. A method for producing a laminate of silicone rubber and fluorosilicone rubber, wherein the composition is cured.