JP5589936B2 - Hydrophilic silicone rubber member - Google Patents

Description

  The present invention relates to a hydrophilic silicone rubber member capable of exhibiting slipperiness when a silicone rubber surface comes into contact with water.

Conventionally, silicone rubber has water repellency, a high friction coefficient, and almost no surface slipperiness. In addition, slipperiness could not be obtained because it repels water even when wet.
And in order to solve these problems, a method of containing a water-soluble component has been proposed, but even if a water-soluble component is contained, if it is used in water, it will be eluted in water, and a sufficient effect will be obtained. There was a problem that it could not be obtained.
In order to deal with these problems, an attempt was made to coat cellulose or the like on the surface as in Patent Document 1 below, but there was a problem of peeling off and dropping off.

JP 2007-082802 A

  The present invention has been made in view of the above circumstances, and it is intended to provide a hydrophilic silicone rubber member that exhibits slipperiness by contact with water without dropping or eluting components contained even when used in water. Objective.

  As a result of intensive studies to achieve the above object, the present inventors have dispersed cellulose derivative powder as a hydrophilic silicone rubber composition in a silicone rubber compound containing organopolysiloxane, particularly dimethylpolysiloxane. The present invention makes it possible to obtain a hydrophilic silicone rubber member that exhibits slipperiness without leaching or falling off of the cellulose derivative powder even when wetted with water. Has been reached.

Accordingly, the present invention provides the following hydrophilic silicone rubber member.
Claim 1:
(A) The average degree of polymerization represented by the following average composition formula (1) and having at least two alkenyl groups and / or cycloalkenyl groups in the molecule blocked with triorganosilyl groups is 100 or more An organopolysiloxane,
R ¹ _a SiO _{(4-a) / 2} (1)
(In the formula, R ¹ is an unsubstituted or halogen-substituted or cyano-substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and a is a number satisfying 1.98 to 2.02.)
(B) As a curing agent, a combination of an organic peroxide or organohydrogenpolysiloxane and a platinum catalyst,
(C) Inorganic filler
A molded and cured body of a hydrophilic silicone rubber composition in which at least one cellulose derivative powder selected from methylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose and carboxymethylcellulose is dispersed in a silicone rubber compound containing A hydrophilic silicone rubber member characterized by (except for the case of a release agent layer of an adhesive tape) .
Claim 2:
The hydrophilic silicone rubber member according to claim 1 , wherein the silicone rubber compound further contains 3 to 15 parts by mass of a wetter with respect to 100 parts by mass of the component (A) .
Claim 3:
The hydrophilic silicone rubber composition comprises an alkenyl group-containing organopolysiloxane in which R ¹ is a methyl group in formula (1) as a component (A) and a component (C), and (B) a non-crosslinked dimethyl compound that does not contain a component. silicone rubber formulation 100 parts by weight, the addition of the cellulose derivative powder 1-100 parts by weight, dispersed becomes in claim 1 or even hydrophilic dimethylsilicone rubber composition obtained by adding a curing agent (B) 2. The hydrophilic silicone rubber member according to 2.
Claim 4 :
The hydrophilic silicone rubber member according to any one of claims 1 to 3 , wherein the hydrophilic silicone rubber member does not have slipperiness during drying and exhibits slipperiness after water immersion.
Claim 5 :
The hydrophilic silicone rubber member according to any one of claims 1 to 4 , which is used for electricity, electronics, automobiles, architecture, medical care, toys or fishing gears.

  In the present invention, the silicone rubber compound means a curable composition containing a curing agent, and the hydrophilic silicone rubber composition means a composition in which cellulose derivative particles are blended with the silicone rubber compound. The silicone rubber compound means a composition that does not contain a curing agent and does not contain cellulose derivative particles.

  The hydrophilic silicone rubber member of the present invention has a water-repellent silicone rubber surface modified to be hydrophilic, has no slipping property when dried, has water affinity after being immersed, and exhibits slipping property. As a silicone rubber capable of obtaining a conflicting effect, it is highly convenient to use.

  The hydrophilic silicone rubber member of the present invention is formed by molding and curing a hydrophilic silicone rubber composition. As the hydrophilic silicone rubber composition for obtaining the hydrophilic silicone rubber member, a silicone rubber compound containing cellulose derivative particles is used.

Silicone rubber compound Here, as a silicone rubber compound, what contains the following (A) and (B) component can be used conveniently, and also containing the following (C) component is preferable in order to raise an intensity | strength.
(A) The following average composition formula (1)
R ¹ _a SiO _{(4-a) / 2} (1)
(Wherein, R ¹ is identical or different unsubstituted or substituted monovalent hydrocarbon group with one another, a is a number that satisfies 1.5 <a <2.8, in total R ^1, 0.001 to 20 mol% is an alkenyl group and / or a cycloalkenyl group.)
An organopolysiloxane having an average degree of polymerization represented by
(B) a curing agent,
(C) Inorganic filler.

The component (A) preferably has an average degree of polymerization of 100 or more from the viewpoint of moldability. More preferably, it is 3,000-100,000. In addition, an average degree of polymerization is a polystyrene conversion weight average value by gel permeation chromatography (GPC). The number of carbon atoms of R ¹ from 1 to 12, and more preferably from 1 to 8. Specific examples of R ¹ include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, octyl group, nonyl group, decyl group and the like. Alkyl groups, cycloalkyl groups such as cyclohexyl groups, vinyl groups, allyl groups, propenyl groups, isopropenyl groups, butenyl groups, isobutenyl groups, alkenyl groups such as hexenyl groups, octenyl groups, and cycloalkenyl groups such as cyclohexenyl groups Aryl groups such as phenyl group, tolyl group, xylyl group and naphthyl group, aralkyl groups such as benzyl group, phenylethyl group and phenylpropyl group, chloromethyl group, bromoethyl group, 3,3,3-trifluoropropyl group, Halogen substitution such as 3-chloropropyl group and cyanoethyl group, cyano group substitution Hydrocarbon group and the like.

Each R ¹ group may be different or the same, but when the composition is an addition reaction curable type or an organic peroxide curable type, at least two alkenyl groups and / or cycloalkenyl groups in the molecule. It is preferable to have. The alkenyl group and / or cycloalkenyl group content is preferably 0.001 mol% or more and 20 mol% or less in the total R ¹ . When the content is less than 0.001 mol%, the curability may be inferior, and when it exceeds 20 mol%, the cured rubber becomes brittle and the mechanical strength may be lowered. A more preferred lower limit is 0.01 mol%, and a more preferred upper limit is 10 mol%. Examples of the organopolysiloxane include those in which R ¹ other than the alkenyl group and / or cycloalkenyl group is a methyl group, or a part of the methyl group of such an organopolysiloxane is a phenyl group, trifluoropropyl Those substituted with a group or the like are preferred.

Further, the molecular chain terminal of the component (A) is preferably blocked with a triorganosilyl group or a hydroxyl group. Examples of the triorganosilyl group include a trimethylsilyl group, a dimethylvinylsilyl group, and a trivinylsilyl group. Is done.
When the composition is a condensation reaction curable type, it is necessary that the molecular chain terminal of the component (A) is blocked with an alkoxy group such as a hydroxyl group or a methoxy group.

  a is preferably a number satisfying 1.5 <a <2.8 from the viewpoint of rubber physical properties after curing. By setting it as this range, the silicone rubber suitable for the use of the present invention in which hardness, elongation, and mechanical strength are balanced can be obtained. A more preferable value of a is in the range of 1.8 to 2.5, and more preferably 1.98 to 2.02.

The organopolysiloxane of the above formula (1) may have a linear molecular structure or a branched structure containing R ¹ SiO _3/2 units or SiO _4/2 units. A linear diorgano in which the chain portion is basically composed of repeating R ¹ ₂ SiO _2/2 diorganosiloxane units and both ends of the molecular chain are blocked with R ¹ ₃ SiO _1/2 triorganosiloxy units. Polysiloxanes can generally be used. Further, when the composition is an addition reaction curable type or an organic peroxide curable type, the alkenyl group and / or cycloalkenyl group in the molecule is bonded to either the molecular chain terminal or the silicon atom in the middle of the molecular chain. It may be bonded to both, but has at least alkenyl groups and / or cycloalkenyl groups bonded to silicon atoms at both ends of the molecular chain from the viewpoints of curability and physical properties of the cured product. Preferably there is.

The curing agent of component (B) can be appropriately selected from known curing agents that are usually used for curing silicone rubber. That is, the curing type of the curable silicone rubber composition used in the present invention may be any of organic peroxide curing type (radical reaction curing type), addition reaction curing type, condensation reaction curing type, and the like. .
In the case of an organic peroxide curable silicone rubber composition, to a known organic peroxide such as di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy). What mix | blended 0.1-10 mass parts organic peroxides, such as a xanthan and a dicumyl peroxide, with respect to 100 mass parts of (A) component is used.
In addition, in the case of an addition reaction curable silicone rubber composition, an organohydrogenpolysiloxane containing at least two hydrogen atoms bonded to a silicon atom and a platinum-based catalyst should be used as an addition reaction curing agent. Can do.
Further, the condensation reaction curable silicone rubber composition contains (D) an organopolysiloxane containing two or more silanol groups and (E) a hydrolyzable group such as an alkoxy group, an acetoxy group, a ketoxime group, or a propenoxy group. A curing agent composed of two or more organosilicon compounds is used. In the present invention, it is preferable to cure by radical reaction and / or addition reaction.

The addition reaction curing agent will be described in more detail. Examples of the organohydrogenpolysiloxane include tris (dimethylhydrogensiloxy) methylsilane, tris (dimethylhydrogensiloxy) phenylsilane, 1,1,3,3-tetramethyldisiloxane. 1,3,5,7-tetramethylcyclotetrasiloxane, methylhydrogencyclopolysiloxane, methylhydrogensiloxane-dimethylsiloxane cyclic copolymer, both ends trimethylsiloxy group-blocked methylhydrogenpolysiloxane, both ends trimethylsiloxy Group-capped dimethylsiloxane / methylhydrogensiloxane copolymer, both-end dimethylhydrogensiloxy-group-capped dimethylpolysiloxane, both-end dimethylhydrogensiloxy-group-capped dimethylene Le siloxane-methylhydrogensiloxane copolymers, both end trimethylsiloxy-blocked methylhydrogensiloxane-diphenylsiloxane copolymers, both end trimethylsiloxy-blocked methylhydrogensiloxane-diphenylsiloxane-dimethylsiloxane copolymer, (CH ₃ ) a copolymer comprising ₂ HSiO _1/2 units and SiO _4/2 units, (CH ₃ ) ₂ HSiO _1/2 units, SiO _4/2 units, and (C ₆ H ₅ ) SiO _3/2 units In these exemplified compounds and the like, a part or all of the methyl group is substituted with another alkyl group such as ethyl group or propyl group, aryl group such as phenyl group, 3,3,3-trifluoropropyl, etc. And those substituted with a halogen-substituted alkyl group such as a group.

  The molecular structure of this organohydrogenpolysiloxane may be any of linear, cyclic, branched, and three-dimensional network structures, but the number of silicon atoms in one molecule, that is, the degree of polymerization is 2-1, 000, preferably 3 to 500, particularly preferably about 3 to 300 can be used.

  The compounding amount of the organohydrogenpolysiloxane is preferably 0.1 to 50 parts by mass, particularly preferably 0.3 to 30 parts by mass with respect to 100 parts by mass of the organopolysiloxane as the component (A). In this case, the SiH group of the organohydrogenpolysiloxane is preferably in an amount of 0.5 to 5 moles per mole of the alkenyl group and / or cycloalkenyl group of the component (A). Platinum black, diplatinum chloride, reaction product of chloroplatinic acid and monohydric alcohol, complex of chloroplatinic acid and olefins, platinum-based catalyst such as platinum bisacetoacetate, palladium-based catalyst, rhodium-based catalyst, etc. It is preferable to use such an amount that the amount of the catalyst becomes 1 to 2,000 ppm of the curable silicone rubber composition.

The inorganic filler as the component (C) may be any substance as long as it is used as a reinforcing material for silicone rubber. For example, fumed silica or precipitated silica that has been subjected to surface hydrophobization treatment or untreated. , Calcined silica, sol-gel method silica, crystalline silica and the like. Preferably, it is a reinforcing silica fine powder, and those used in conventional silicone rubber compositions can be used, and in particular, a reinforcing silica fine powder having a specific surface area of 50 m ² / g or more by the BET method is used. . In particular, precipitated silica, fumed silica, calcined silica and the like having a specific surface area of 50 to 800 m ² / g are preferably used. Fumed silica is suitable for improving rubber strength. If the specific surface area is less than 50 m ² / g, the reinforcing effect may not be sufficiently obtained.

  The reinforcing silica fine powder may be a surface-treated silica fine powder. In that case, these silica fine powders may be directly embedded in a powder state in advance. It can be processed by a generally known technique as a normal processing method. For example, the untreated silica fine powder and the processing agent are put in a mechanical kneading apparatus or fluidized bed sealed at normal pressure, and an inert gas is present if necessary. Under the mixing treatment at room temperature or heat treatment. In some cases, a catalyst may be used to facilitate the treatment. After kneading, the treated silica fine powder can be produced by 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. Treatment agents are silazanes such as hexamethyldisilazane, methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, dimethyldimethoxysilane, diethyldimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane Silane coupling agents such as trimethylmethoxysilane, triethylmethoxysilane, vinyltris (methoxyethoxy) silane, trimethylchlorosilane, dimethyldichlorosilane, divinyldimethoxysilane, chloropropyltrimethoxysilane, polymethylsiloxane, organohydrogenpolysiloxane, etc. These organic silicon compounds are surface-treated with these and used as hydrophobic silica fine powder. As the treating agent, silane coupling agents or silazanes are particularly preferable.

  In addition, as described above, as the inorganic filler, fine powder silica (surface hydrophobized or untreated fumed silica, precipitated silica, calcined silica, sol-gel silica, crystalline silica, etc.), diatomaceous earth One or two or more inorganic fillers selected from reinforcing or non-reinforcing inorganic fillers such as calcium carbonate and thermally conductive inorganic fillers such as titanium oxide, zinc oxide, and aluminum oxide are used. .

  As a compounding quantity of an inorganic filler, it is preferable to set it as 0-100 mass parts with respect to 100 mass parts of base polymers (organopolysiloxane of (A) component), More preferably, it is 0-60 mass parts, More preferably It can be set as the compounding quantity of the range of 10-50 mass parts.

  In this case, the silicone rubber compound constituting the silicone rubber compound includes a curable dimethylpolysiloxane containing an alkenyl group such as a vinyl group or having a molecular chain terminal blocked with a hydroxyl group or an alkoxy group, and the dimethylpolysiloxane It is preferable to use an inorganic filler or an uncrosslinked dimethyl silicone rubber compound composed of the dimethylpolysiloxane, an inorganic filler, and a wetter.

  The uncrosslinked dimethyl silicone rubber compound contains a curable dimethylpolysiloxane containing an alkenyl group such as a vinyl group as a main agent (base polymer) or having a molecular chain terminal blocked with a hydroxyl group or an alkoxy group, and fine particles as necessary. It contains an inorganic filler such as powdered silica and a wetter (dispersant for dispersing the inorganic filler) as needed in addition to the inorganic filler. A curing agent (or a crosslinking agent and a curing catalyst) can be appropriately blended. Specifically, as a form in which a curing agent (or a combination of a crosslinking agent and a curing catalyst) is blended with an uncrosslinked dimethyl silicone rubber compound, a dimethyl silicone resin composition, a millable dimethyl silicone rubber composition, a liquid dimethyl silicone A rubber composition etc. are mentioned.

  As the wetter, silanol group-containing silanes and / or siloxane oligomers such as diphenylsilane diol and silanol group-blocked organosiloxane oligomers at both molecular chains are used. Moreover, as a compounding quantity of a wetter, it is preferable to set it as 0-25 mass parts with respect to 100 mass parts of base polymers, More preferably, it is 3-20 mass parts, More preferably, it is 5-15 mass parts. It can be.

  The curing method can be selected from a heat curing type, a room temperature curing type, an ultraviolet curing type, or a combination thereof, and as a crosslinking form, an addition (hydrosilylation) crosslinking type, a condensation crosslinking type, or an organic peroxide crosslinking. You can choose from types.

  As an uncrosslinked dimethyl silicone rubber compound or a compound in which a curing agent is compounded, a compound generally available in the market can be used as it is. Specifically, for example, millable type silicone rubber compounds KE-571-U, KE-1571-U, KE-951-U, KE-541-U, KE-551-U, KE-561-U, KE-961T -U, KE-1541-U, KE-1551-U, KE-941-U, KE-971T-U (all manufactured by Shin-Etsu Chemical Co., Ltd.), and liquid addition curable silicone rubber composition KE-1950 -40A / B, KE-1950-50A / B, KE-1950-60A / B, KE-1950-70A / B, KEG-2000-40A / B, KEG-2000-50A / B, KEG-2000-60A / B, KEG-2000-70A / B (all manufactured by Shin-Etsu Chemical Co., Ltd.), highly transparent liquid addition curable silicone rubber composition KE-1935A / B, X-34 1931a / B (manufactured by Shin-Etsu Chemical Co.) and the like.

Hydrophilic Silicone Rubber Composition The hydrophilic silicone rubber composition of the present invention is obtained by blending cellulose derivative powder with the above silicone rubber compound. As the cellulose derivative powder, at least one selected from derivatives such as methylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose and the like can be used.

  In the present invention, the cellulose derivative powder is added in an amount of 1 to 100 parts by weight, preferably 3 to 70 parts by weight, more preferably 7 to 60 parts by weight, more preferably 10 to 100 parts by weight of the uncrosslinked dimethyl silicone rubber compound. Add ~ 50 parts by mass and disperse. If the cellulose derivative powder is less than 0.1 parts by mass, sufficient slipperiness may not be exhibited. If the cellulose derivative powder exceeds 100 parts by mass, the viscosity of the hydrophilic silicone rubber composition increases, the kneadability deteriorates, and the rubber strength is reduced. There may be a disadvantage that it is lowered.

In the present invention, the average particle size of the cellulose derivative powder particles is 1 to 150 μm, preferably 1 to 50 μm, more preferably 3 to 20 μm, and still more preferably 5 to 16 μm. Fine particles having an average particle size of less than 1 μm may have a low compounding efficiency, and particles having an average particle size of more than 150 μm may have a disadvantage that the physical properties of the rubber are deteriorated. In the present invention, the average particle size can be measured as the cumulative weight average value D ₅₀ (or median diameter) in the particle size distribution measurement by laser light diffraction.

  As such a cellulose derivative powder, commercially available products can be used. For example, carboxymethylcellulose (cellogen) manufactured by Daiichi Kogyo Seiyaku, hydroxyethylcellulose (HEC) manufactured by Daicel, and methylcellulose manufactured by Shin-Etsu Chemical Co., Ltd. , Hydroxypropylmethylcellulose (Metroses), hydroxypropylcellulose (L-HPC) and the like can be suitably used.

  Various additives can be blended in the hydrophilic silicone rubber composition according to the present invention as long as the physical properties of the silicone rubber are not impaired. For example, an antistatic agent, a coloring agent, an antioxidant, etc. are mentioned, and these may be used alone or in combination. The antistatic agent prevents adhesion of dust due to static electricity on the surface of the hydrophilic silicone rubber molding, and the colorant imparts color to the hydrophilic silicone rubber molding to improve the design. Each of them is added to suppress coloring due to oxidative deterioration of the silicone rubber.

Antistatic agents that can be incorporated into the hydrophilic silicone rubber composition according to the present invention include carbon, conductive zinc white, lithium salt-containing ionic conductive agents such as lithium perchlorate and amidolithium, imidazolium salts and pyridinium salts, etc. Ionic liquids, alcohol derivatives, glycol derivatives, glycerin derivatives, polyether derivatives, and the like. As the antistatic agent, in particular lithium salts are preferred, _{specifically, LiBF 4, LiClO 4, LiPF} 6, LiAsF 6, LiSbF 6, LiSO 3 CF 3, LiN (SO 2 CF 3) 2, LiSO 3 C 4 A large antistatic effect is observed when a small amount of F ₉ , LiC (SO ₂ CF ₃ ) ₃ , LiB (C ₆ H ₅ ) ₄ or the like is added.

  One type of antistatic agent may be used alone, or a plurality of antistatic agents may be used in combination. However, it is preferable to use an antistatic agent as long as the solid antistatic agent does not deteriorate the hydrophilic performance. The amount of the antistatic agent used is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the silicone rubber compound.

  Here, with respect to the antistatic level, static electricity is charged by corona discharge on the surface of the molded product obtained by curing the hydrophilic silicone rubber composition using a static one meter (manufactured by Sisid Electric Co., Ltd.). Then, it can be evaluated by measuring the time when the charged voltage is halved. Regarding the chargeability level of the present invention, the half-life time is preferably 2 minutes or less, particularly preferably 1 minute or less.

  As colorants, organic pigments such as condensed azo, isoindolinone, quinacridone, diketopyrrolopyrrole, anthraquinone, dioxazine, copper phthalocyanine, allylamide, titanium oxide, zinc oxide, iron oxide (red bengara, black bengara), Examples include inorganic pigments such as ultramarine, cobalt blue, carbon, bismuth vanadate, and dyes such as azo, chromium complexes, cobalt complexes, and phthalocyanines. From the viewpoint of dispersibility, hydrophilicity, and color stability in hydrophilic silicone rubber compositions Organic pigments and inorganic pigments are preferably used. These may be used alone or in combination. Many of the colorants have the property of hindering light transmission. Therefore, when a large amount is added, the total light transmittance is lowered. Therefore, the blending amount in the case of using the colorant is preferably 0.0001 to 0.1 parts by mass, more preferably 0.001 to 0.01 parts by mass with respect to 100 parts by mass of the silicone rubber compound.

  Antioxidants include hydroquinone, hydroquinone monomethyl ether, t-butyl hydroquinone, 2,6-di-t-butyl-4-methylphenol (BHT), 2,2′-methylenebis (6-t-butyl-4- Examples thereof include hindered phenol compounds such as methylphenol, and these may be used alone or in combination. 0.001-1 mass part is preferable with respect to 100 mass parts of silicone rubber compounds, and, as for the compounding quantity in the case of using antioxidant, More preferably, it is 0.01-0.1 mass part.

  As the curing conditions for the hydrophilic silicone rubber composition according to the present invention, in addition crosslinking, press molding or usual conditions are usually performed at 100 to 180 ° C. for 3 to 15 minutes, preferably 120 to 150 ° C. for 5 to 10 minutes. It can be subjected to pressurized hot air vulcanization (HAV), and is preferably subjected to secondary curing (post cure) for about 1 to 4 hours at 150 to 200 ° C., if necessary. In organic peroxide crosslinking, Press molding or atmospheric pressure hot air vulcanization (HAV) can be performed at 120 to 200 ° C. for 3 to 15 minutes, preferably 150 to 180 ° C. for 5 to 10 minutes, and then 150 to 200 ° C. as necessary. It is preferable to perform secondary curing (post cure) for about 1 to 4 hours. In the case of condensation crosslinking, it is usually preferable to cure at 10 to 50 ° C. for 10 minutes to 3 days.

The hydrophilic silicone rubber member of the present invention can be used as a single layer, but if necessary, on one or both sides, a back coat layer, a vibration proof layer, a magnetic layer, an antistatic layer, a hard coat layer, a conductive layer, an antireflection layer One kind or two or more kinds of different layers such as an adhesive layer may be provided.
Further, the surface may be processed, and blasting, graining, sanding, corona treatment, plasma treatment, excimer laser treatment, or the like may be performed depending on the situation.

  Examples of the molding method include injection molding, compression molding, injection molding, extrusion molding, transfer molding and the like when molding. When performing sheeting, calendar molding, extrusion molding, coating molding, and the like can be given. In the case of coating, it can be prepared by applying on a support by a bar coater, blade coater, spin coater, roll coater, gravure coater, flow coater, die coater, spray, screen printing or the like and drying. In the case of processing into a flat shape, it is preferable to form a sheet by calendering and then punch it into a required size. If thin film properties are required, a coating method may be selected. In order to obtain a required shape in accordance with other situations, it is possible to perform molding by selecting from the above molding methods.

  The hydrophilic silicone rubber member according to the present invention is used around water use and can be used for applications requiring slipperiness, for example, electric, electronic, automobile, architecture, medical, toy, fishing equipment. Can be used in the field.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited to these Examples.

[Example 1]
Millable dimethyl silicone rubber compound KE-571-U containing vinyl groups as a transparent uncrosslinked dimethyl silicone rubber compound (manufactured by Shin-Etsu Chemical Co., Ltd., based on dimethylpolysiloxane having a degree of polymerization of about 5,000) , Containing 40% by mass or less of dry silica having a specific surface area of 200 m ² / g by BET method and 10% by mass or less of silanol group-blocked dimethylsiloxane oligomer (silica dispersant) having a molecular weight of 700 or less, and a phenyl group in the compound 40 parts by mass of Metrose 90SH-100,000 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) as cellulose derivative particles was added to 100 parts by mass, and the mixture was kneaded and dispersed with a kneader to give milky white hydrophilic dimethyl silicone. A rubber composition base was obtained.

  0.5 / 2.0 parts by mass of an addition (hydrosilylation) reaction system vulcanizing agent C-25A / B (manufactured by Shin-Etsu Chemical Co., Ltd.) is added to 100 parts by mass of the hydrophilic dimethyl silicone rubber composition base. Then, the hydrophilic dimethyl silicone rubber composition kneaded by two rolls is sandwiched between surface glossy PET films and press-molded at 120 ° C. for 10 minutes using a mold capable of obtaining a sheet having a thickness of 2 mm. Got. Furthermore, this sheet was subjected to secondary heating (post-cure) at 200 ° C. for 4 hours, and the obtained cured sheet was evaluated by the following evaluation method.

[Example 2]
To 100 parts by mass of the hydrophilic dimethyl silicone rubber composition base of Example 1, 1.0 part by mass of an organic peroxide vulcanizing agent C-8B (manufactured by Shin-Etsu Chemical Co., Ltd.) was added as a crosslinking agent. Various evaluations were performed in the same manner as in Example 1 using a 2 mm thick cured sheet obtained by kneading with this roll and press-molding in the same manner as in Example 1.

[Comparative Example 1]
Millable dimethyl silicone rubber compound KE-571-U containing vinyl groups as a transparent uncrosslinked dimethyl silicone rubber compound (manufactured by Shin-Etsu Chemical Co., Ltd., based on dimethylpolysiloxane having a polymerization degree of about 5,000) , Containing 40% by mass or less of dry silica having a specific surface area of 200 m ² / g by BET method and 10% by mass or less of silanol group-blocked dimethylsiloxane oligomer (silica dispersant) having a molecular weight of 700 or less, and a phenyl group in the compound Is added) to 100 parts by mass of 0.5 / 2.0 parts by mass of an addition (hydrosilylation) reaction vulcanizing agent C-25A / B (manufactured by Shin-Etsu Chemical Co., Ltd.). A dimethyl silicone rubber composition kneaded with this roll is sandwiched between glossy PET films so that a sheet with a thickness of 2 mm can be obtained. Using a mold to obtain a sheet by press molding for 10 minutes at 120 ° C.. Furthermore, this sheet was subjected to secondary heating (post-cure) at 200 ° C. for 4 hours, and the obtained cured sheet was evaluated by the following evaluation method.

[Evaluation method]
Surface slipperiness at the time of drying: The dry rubber surface was touched by hand to determine the presence or absence of slipperiness.
Those with slipperiness were marked with ×, and those without slippery were marked with ○.
Slip after water immersion: After soaking in water for 1 minute, it was taken out and checked for slippery by hand.
Those having slipperiness were marked with ◯, and those without slipping were marked with ×.
Durability after re-immersion: After being submerged in the above, submerged for 10 minutes, then taken out and slipped by hand
The presence or absence of sex was confirmed.
Those having slipperiness were marked with ◯, and those without slipping were marked with ×.
Sliding property after soaking and drying: The surface of the soaked rubber is dried by hand at 80 ° C for 1 hour.
The presence or absence of touch and slipperiness was judged.
Those with slipperiness were marked with ×, and those without slippery were marked with ○.
The evaluation results of Examples 1 and 2 and Comparative Example 1 are shown in the following table.

メトローズ：ヒドロキシプロピルメチルセルロース

Metroz: Hydroxypropyl methylcellulose

Claims (5)

(A) The average degree of polymerization represented by the following average composition formula (1) and having at least two alkenyl groups and / or cycloalkenyl groups in the molecule blocked with triorganosilyl groups is 100 or more An organopolysiloxane,
R ¹ _a SiO _{(4-a) / 2} (1)
(In the formula, R ¹ is an unsubstituted or halogen-substituted or cyano-substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and a is a number satisfying 1.98 to 2.02.)
(B) As a curing agent, a combination of an organic peroxide or organohydrogenpolysiloxane and a platinum catalyst,
(C) Inorganic filler
A molded and cured body of a hydrophilic silicone rubber composition in which at least one cellulose derivative powder selected from methylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose and carboxymethylcellulose is dispersed in a silicone rubber compound containing A hydrophilic silicone rubber member characterized by (except for the case of a release agent layer of an adhesive tape) . The hydrophilic silicone rubber member according to claim 1 , wherein the silicone rubber compound further contains 3 to 15 parts by mass of a wetter with respect to 100 parts by mass of the component (A) . The hydrophilic silicone rubber composition comprises an alkenyl group-containing organopolysiloxane in which R ¹ is a methyl group in formula (1) as a component (A) and a component (C), and (B) a non-crosslinked dimethyl compound that does not contain a component. silicone rubber formulation 100 parts by weight, the addition of the cellulose derivative powder 1-100 parts by weight, dispersed becomes in claim 1 or even hydrophilic dimethylsilicone rubber composition obtained by adding a curing agent (B) 2. The hydrophilic silicone rubber member according to 2. The hydrophilic silicone rubber member according to any one of claims 1 to 3 , wherein the hydrophilic silicone rubber member does not have slipperiness during drying and exhibits slipperiness after water immersion. The hydrophilic silicone rubber member according to any one of claims 1 to 4 , which is used for electricity, electronics, automobiles, architecture, medical care, toys or fishing gears.