JP2000026724A - Silicone gel suspension and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a silicone gel suspension having excellent handling workability and capable of forming a silicone gel having excellent viscoelasticity through removing water from the suspension to effect aggregation of silicone gel particles, and to provide a method for the production of this suspension. SOLUTION: This silicone gel suspension is such one that silicone gel particles having an average particle diameter of 0.1-100 μm are dispersed in an aqueous solution of a surfactant. The method for the production of the silicone gel suspension comprises dispersing a silicone gel composition in an aqueous solution of a surfactant so as to cause 0.1-100 μm in the average particle diameter of the resulting particles followed by hardening the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silicone gel suspension in which silicone gel particles are dispersed in an aqueous solution of a surfactant, and a method for producing the same. The present invention relates to a silicone gel suspension capable of forming a silicone gel having excellent viscoelasticity by assembling silicone gel particles, and a method for producing the same.

[0002]

2. Description of the Related Art Silicon gel has a peculiar viscoelasticity, and is therefore used as an anti-vibration material and a sealing material for electric and electronic equipment. Because silicone gel is sticky, in general,
It is treated as a silicone gel composition in a state before curing. On the other hand, a silicone gel suspension in which silicone gel particles are dispersed in water is disclosed in
No. 4,14,250 and Japanese Patent Application Laid-Open No. 1-178523. However, the silicone gel particles disclosed in these publications have a large particle size, have poor stability as a silicone gel suspension, and furthermore, a silicone gel obtained by collecting silicone gel particles by removing water is And did not have any specific viscoelasticity.

[0003]

DISCLOSURE OF THE INVENTION The present inventors have intensively studied the above-mentioned problems, and as a result, have reached the present invention. That is, an object of the present invention is to provide a silicone gel suspension which has good handling workability, forms silicone gel particles by removing water, and forms a silicone gel having excellent viscoelasticity, and a method for producing the same. Is to provide.

[0004]

The silicone gel suspension of the present invention is characterized in that silicone gogel particles having an average particle size of 0.1 to 100 μm are dispersed in an aqueous surfactant solution. Further, the method for producing a silicone gel suspension of the present invention comprises the steps of: preparing a silicone gel composition in an aqueous surfactant solution;
It is characterized by being dispersed and cured to have a thickness of 100 μm.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the silicone gel suspension of the present invention will be described in detail. The silicone gel suspension of the present invention is one in which silicone gel particles are dispersed in an aqueous solution of a surfactant, and the average particle size of the silicone gel particles is in the range of 0.1 to 100 μm. 0.1 to 50 μm,
Particularly preferably, it is in the range of 0.5 to 10 μm. This is because if the average particle size of the silicone gel particles exceeds the upper limit of this range, a stable silicone gel suspension cannot be formed, and the silicone gel formed by collecting the silicone gel particles by removing water. Is no different from the viscoelasticity of the silicone gel obtained by curing the silicone gel composition itself forming the silicone gel particles, while preparing a silicone gel suspension less than the lower limit of this range. It is difficult to do so. Examples of the shape of the silicone gel particles include a sphere, a flat shape, and an irregular shape, and the shape is preferably spherical because the stability of the obtained silicone gel suspension is good.

In the silicone gel suspension of the present invention, the aqueous surfactant solution is a medium for dispersing the silicone gel particles. Examples of the surfactant include primary to tertiary aliphatic amine salts, alkyl trimethyl ammonium salts, dialkyl dimethyl ammonium salts,
Tetraalkylammonium salt, trialkylbenzylammonium salt, alkylpyridinium salt, N, N'-
Cationic surfactants such as dialkyl monoformolinium salts and polyethylene polyamine fatty acid amide salts; fatty acid salts, alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl sulfonates, α-olefin sulfonates, dialkyl sulfosuccinates , Α-sulfonated fatty acid salt, N-acyl-N-methyltaurate, alkyl sulfate, sulfated oil, polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl phenyl ether sulfate, polyoxyethylene styrenated phenyl ether Anionic surfactants such as sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phenyl ether phosphates, and naphthalene sulfonate formaldehyde condensates; N, N-di Methyl-N-alkyl-N-carboxymethylammonium betaine, N, N-dialkylaminoalkylenecarboxylate, N, N, N-trialkyl-N-sulfoalkylammonium betaine,
N, N-dialkyl-N, N-bispolyoxyethylene ammonium sulfate betaine, 2-alkyl-1
Zwitterionic surfactants such as carboxymethyl-1-hydroxyethylomidazolinium betaine; polyoxyethylene alkyl ether, polyoxyethylene alkenyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene polystyryl phenyl ether, polyoxyethylene Oxyethylene / polyoxypropylene glycol, polyoxyethylene / polyoxypropylene alkyl ether, sorbitan fatty acid ester, glycerin fatty acid ester, decaglycerin fatty acid ester, polyglycerin fatty acid ester, propylene glycol
Polyhydric alcohol fatty acid partial esters such as pentaerythritol fatty acid ester, propylene glycol and pentaerythritol fatty acid ester, polyoxyethylene polyhydric alcohol fatty acid partial esters such as polyoxyethylene sorbitan fatty acid ester and polyoxyethylene glycerin fatty acid ester, and polyoxyethylene fatty acid Nonionic interfaces such as esters, polyglycerin fatty acid esters, polyoxyethylated castor oil, fatty acid diethanolamide, polyoxyethylene alkylamine, triethanolamine fatty acid partial ester, trialkylamine oxide, and polyoxyalkylene group-containing organopolysiloxane Illustrative are surfactants and mixtures of two or more of these surfactants. The amount of the surfactant is 0.1 to 20 parts by weight based on 100 parts by weight of the silicone gel particles.
It is preferably in the range of parts by weight, particularly 0.1 to 0.1 parts by weight.
Preferably it is in the range of 10 parts by weight. The amount of water to be added is not limited, but is preferably in the range of 10 to 200 parts by weight based on 100 parts by weight of the silicone gel particles.

[0007] The silicone gel obtained by assembling the silicone gel particles by removing water from the silicone gel suspension of the present invention may have a 1/4 consistency defined by JIS K 2220 in the range of 10 to 200. It is particularly preferred that this is in the range of 20 to 150. This is because, when the 1/4 consistency of the silicone gel obtained by assembling the silicone gel particles exceeds the upper limit of this value, the silicone gel exhibits an action similar to that of the silicone oil emulsion. If the value is less than the lower limit, an effect similar to that of the silicone rubber suspension is exhibited. further,
The silicone gel obtained by assembling the silicone gel particles by removing water from the silicone gel suspension of the present invention has a strain of 25 ° C., a strain rate of 10%, and a vibration frequency of 1 rad /.
Those having a dynamic viscoelasticity value (tan δ) of 1 or more at 10 to 10 rad / sec are preferable. This is because the silicone gel obtained by assembling the silicone gel particles has improved vibration damping properties and increased vibration absorbing ability.

Further, silicone oil may be added to the silicone gel particles in the silicone gel suspension of the present invention in advance. As this silicone oil,
It is preferable that they do not participate in the formation reaction of the silicone gel particles, and examples thereof include dimethylpolysiloxane having trimethylsiloxy groups at both ends of molecular chains and methylphenylpolysiloxane having trimethylsiloxy groups at both ends of molecular chains. The amount of the silicone oil added is preferably 10% by weight or less of the silicone gel particles, more preferably 5% by weight or less, and particularly preferably 0.5% by weight or less. Also,
In order to improve the strength and control the specific gravity of the silicone gel particles, inorganic fillers such as silica fine powder, iron oxide aluminosilicate, etc., and inorganic fillers whose surfaces have been hydrophobized with an organosilicon compound are used in advance. It may be added.

The silicone gel suspension of the present invention exhibits properties such as liquid, cream, and paste, and is used as a paint additive; a cosmetic raw material; a thermosetting or thermoplastic organic resin modifier; It is useful as a silicone gel forming material such as a shock absorbing material, a vibration damping material and the like.

Next, the method for producing the silicone gel suspension of the present invention will be described in detail. The method for producing a silicone gel suspension of the present invention comprises the steps of: preparing a silicone gel composition in an aqueous solution of a surfactant;
It is characterized by being dispersed and cured so as to have a thickness of 00 μm. As this silicone gel composition, for example,
Hydrosilylation-curable, condensation-reaction-curable, radical-reaction-curable, and high-energy-ray-curable ones are preferred, and the use of hydrosilylation-curable ones is particularly preferred. Examples of the hydrosilylation-curable silicone gel composition include a composition comprising at least an alkenyl group-containing organopolysiloxane, a silicon-bonded hydrogen atom-containing organopolysiloxane, and a catalyst for a hydrosilylation reaction.

Examples of the alkenyl group-containing organopolysiloxane include linear, partially branched linear, branched, cyclic, and resinous ones. It is preferably linear or linear having a partly branched chain. Examples of the alkenyl group in the organopolysiloxane include a vinyl group, an allyl group, a butenyl group, a pentenyl group, and a hexenyl group, and a vinyl group is particularly preferable. Examples of the silicon-bonded group other than the alkenyl group in the organopolysiloxane include an alkyl group such as a methyl group, an ethyl group and a propyl group; an aryl group such as a phenyl group, a tolyl group and a xylyl group; a benzyl group and a phenethyl group An aralkyl group such as a group; a substituted or unsubstituted monovalent hydrocarbon group such as a halogenated alkyl group such as a 3,3,3-trifluoropropyl group; an alkoxy group such as a methoxy group, an ethoxy group, and a propoxy group; It is exemplified, and particularly preferably a methyl group, a phenyl group, and a 3,3,3-trifluoropropyl group.

The organopolysiloxane containing a silicon-bonded hydrogen atom includes linear, partially branched linear, branched, and cyclic organopolysiloxanes.
Resin-like ones are exemplified, and in particular, straight-chain ones or straight-chain ones partially branched are preferable. Examples of the silicon-bonded group other than a hydrogen atom in the organopolysiloxane include an alkyl group such as a methyl group, an ethyl group and a propyl group; an aryl group such as a phenyl group, a tolyl group and a xylyl group; a benzyl group and a phenethyl group; Aralkyl group; substituted or unsubstituted monovalent hydrocarbon group such as halogenated alkyl group such as 3,3,3-trifluoropropyl group; alkoxy group such as methoxy group, ethoxy group and propoxy group; and hydroxyl group. Particularly, a methyl group, a phenyl group, and a 3,3,3-trifluoropropyl group are preferable.

Examples of the catalyst for the hydrosilylation reaction include a platinum-based catalyst, a rhodium-based catalyst, and a palladium-based catalyst. A platinum-based catalyst is particularly preferred because the hydrosilylation reaction proceeds smoothly. Examples of the platinum catalyst include chloroplatinic acid, an alcohol solution of chloroplatinic acid, and an olefin complex of platinum. An alkenylsiloxane complex of platinum is exemplified. The compounding amount of the hydrosilylation reaction catalyst may be an amount sufficient to cure the above-mentioned hydrosilylation reaction-curable silicone gel composition.Specifically, a platinum-based catalyst is used as the hydrosilylation reaction catalyst. When used, the amount is preferably such that the weight of the platinum metal is 0.1 to 100 ppm based on the total amount of the alkenyl group-containing organopolysiloxane and the silicon-bonded hydrogen atom-containing organopolysiloxane. Since the properties progress smoothly, and the resulting silicone gel particles are hardly colored,
Preferably, the amount is in the range of ５０50 ppm.

In the production method of the present invention, such a silicone gel composition is uniformly dispersed in an aqueous solution of a surfactant, and usable surfactants include the above-mentioned cationic surfactants; Such anionic surfactants; zwitterionic surfactants as described above; nonionic surfactants as described above; and mixtures of two or more of these surfactants, for example, the above-mentioned hydrosilylation reaction curing The above-mentioned nonionic surfactant is particularly preferable because it hardly inhibits the curing of the water-soluble silicone gel composition. The addition amount of this surfactant is preferably in the range of 0.1 to 20 parts by weight, and particularly preferably in the range of 0.1 to 10 parts by weight, based on 100 parts by weight of the silicone gel composition. preferable. The amount of water to be added is not limited, but may be 10 to 100 parts by weight of the silicone gel composition.
It is preferably in the range of 200 to 200 parts by weight.

In the method for producing a silicone gel suspension of the present invention, the method of dispersing the silicone gel composition in an aqueous surfactant solution includes, for example, a batch method,
A continuous type is exemplified, and as a device for this, a homomixer, a paddle mixer, a Henschel mixer, a homodisper, a colloid mixer, a propeller stirrer, a homogenizer, an in-line type continuous emulsifier, an ultrasonic emulsifier, and a vacuum kneader. Is exemplified.

As described above, after dispersing the silicone gel composition in the aqueous surfactant solution, the composition is cured to obtain a silicone gel suspension. When the silicone gel composition is a hydrosilylation-curable or condensation-curable emulsion, it can be cured by heating the emulsion of the silicone gel composition as necessary to obtain a radical. In the case of a reaction curable one, the emulsion can be cured by heating, and in the case of a high energy ray-curable one, the emulsion is cured by irradiating it with a high energy ray. be able to.

Next, another method for producing a silicone gel suspension of the present invention will be described in detail. Although the production method of the present invention is a production method using the above-mentioned hydrosilylation reaction-curable silicone gel composition, the order of addition of the hydrosilylation reaction catalyst is different. That is, in the method for producing a silicone gel suspension of the present invention, in a surfactant aqueous solution, a hydrosilylation reaction-curing silicone gel composition that does not contain a hydrosilylation reaction catalyst has an average particle size of 0.1 to 100 μm. After the dispersion, the catalyst for hydrosilylation reaction is added thereto. The composition of this silicone gel composition for hydrosilylation reaction curing is the same as described above. The hydrosilylation reaction catalyst is the same as above. According to the production method of the present invention, a silicone gel composition for curing a hydrosilylation reaction that does not contain a catalyst for a hydrosilylation reaction can be sufficiently dispersed in an aqueous surfactant solution, so that a uniform emulsion of the composition can be obtained. It can be prepared, and then a catalyst for hydrosilylation reaction is added thereto, whereby uniform silicone gel particles can be obtained. In the production method of the present invention, it is preferable from the viewpoint of the reaction that the catalyst for hydrosilylation reaction is added rather than added as it is, in which the catalyst is dispersed in an aqueous surfactant solution in advance.

In the production method of the present invention, such a silicone gel composition is uniformly dispersed in an aqueous solution of a surfactant, and usable surfactants include the above-mentioned cationic surfactants; Anionic surfactants such as the above; zwitterionic surfactants as described above; nonionic surfactants as described above, and mixtures of two or more of these surfactants. The above-mentioned nonionic surfactant is particularly preferred because it hardly inhibits the curing of the curable silicone gel composition. The addition amount of this surfactant is preferably in the range of 0.1 to 20 parts by weight, and particularly preferably in the range of 0.1 to 10 parts by weight, based on 100 parts by weight of the silicone gel composition. preferable. The amount of water to be added is not limited, but is preferably in the range of 10 to 200 parts by weight based on 100 parts by weight of the silicone gel composition.

In the method for producing a silicone gel suspension of the present invention, the method of dispersing the silicone gel composition in an aqueous surfactant solution includes, for example, a batch method,
A continuous type is exemplified, and as an apparatus for this, an apparatus similar to the above is exemplified.

After dispersing the silicone gel composition in the aqueous surfactant solution as described above, the composition can be cured by heating if necessary.

[0021]

EXAMPLES The silicone gel suspension of the present invention and the method for producing the same will be described in detail with reference to examples. In addition, the viscosity in an Example is a value in 25 degreeC. [Average particle size of silicone gel suspension] Laser diffraction particle size distribution analyzer
(LA-500 manufactured by Horiba, Ltd.), and the average particle diameter was determined from the median diameter (particle diameter corresponding to 50% of the cumulative distribution). [Stability of Silicone Gel Suspension] Put 50 ml of the silicone gel suspension in a 100 ml bottle,
After standing at room temperature for 2 weeks, shake by hand 10 times, apply to corrugated cardboard, observe the surface roughness of the coating film after 2 days of air drying, and evaluate the cohesiveness of the silicone gel particles. , Δ: There are aggregated particles of 0.1 mm or less, and X: There are aggregated particles of 0.1 mm or more. [1/4 of silicone gel composed of silicone gel particles]
Consistency] A method in which a silicone gel suspension is poured into a Teflon dish having a depth of 5 mm, air-dried for 1 week to remove water, put into a 100 ml beaker, defoamed, and then stipulated in JIS K2220. According to the above, 1/4 consistency of the silicone gel formed by assembling the silicone gel particles was measured. [Dynamic viscoelasticity value] For a silicone gel obtained by removing water from a silicone gel suspension in the same manner as described above,
This was measured with an ARES viscoelasticity measuring device manufactured by Reometric Metric Scientific, and was 25.0 mm in diameter.
The gap was set to 0.5 to 0.6 mm using the parallel plate described above, and measurement was performed at room temperature. Distortion 10.0%, frequency 0.1
The average tan δ when varying from rad / sec to 10 rad / sec was determined. [Volume average particle diameter of liquid catalyst] The volume average particle diameter of the hydrosilylation reaction catalyst dispersed in an aqueous surfactant solution is measured by a laser scattering submicron particle analyzer (COULTER N4 type manufactured by Coulter Electronics Co., Ltd.). Asked from.

Example 1 68 parts by weight of a dimethylpolysiloxane (vinyl group content = 0.48% by weight) having a dimethylvinylsiloxy group at both ends of a molecular chain having a viscosity of 400 mPa · s.
31 parts by weight of a dimethylpolysiloxane having a dimethylhydrogensiloxy group at both ends of the molecular chain having a viscosity of 130 mPa · s (content of silicon-bonded hydrogen atoms = 0.025% by weight),
And 1.5 parts by weight of a dimethylpolysiloxane-methylhydrogenpolysiloxane copolymer (content of silicon-bonded hydrogen atoms = 0.14% by weight) having a trimethylsiloxy group at both ends of a molecular chain having a viscosity of 20 mPa · s. 3% by weight of polyoxyethylene nonyl phenyl ether
(HLB = 13.1) After emulsification with 30 parts by weight of an aqueous solution, 20 parts by weight of pure water was added to prepare an emulsion of a silicone gel composition for hydrosilylation reaction curing which did not contain a curing catalyst for hydrosilylation reaction.

Next, a hydrosilyl solution comprising a 1,3-divinyl-tetramethyldisiloxane solution containing a 1,3-divinyl-tetramethyldisiloxane complex of platinum as a main component was prepared separately from the above emulsion. Emulsion of a catalyst for the polymerization reaction (volume average particle size of the catalyst = 0.05μ)
m, the ratio of a catalyst having a particle size of 1 μm or less = 95% by weight and the concentration of platinum metal = 0.04% by weight), which is 20 ppm by weight based on the total weight of the organopolysiloxane in the emulsion. The emulsion was mixed and stirred uniformly to prepare an emulsion of the hydrosilylation reaction-curable silicone gel composition, and the emulsion was allowed to stand at room temperature for one day to cure the composition and cure the silicone gel suspension. And Table 1 shows the average particle size, stability, and characteristics of the silicone gel obtained by removing water from the suspension.

[Example 2] In Example 1, the viscosity was 40
67.2 parts by weight of dimethylpolysiloxane blocked with dimethylvinylsiloxy groups at both ends of the molecular chain of 0 mPa · s (vinyl group content = 0.48% by weight) and dimethylhydrogensiloxy at both ends of the molecular chain having a viscosity of 130 mPa · s A silicone gel suspension was prepared in the same manner as in Example 1 except that the amount of the base-blocked dimethylpolysiloxane was changed to 31.3 parts by weight. Table 1 shows the average particle size, stability, and characteristics of the silicone gel obtained by removing water from the suspension.

Example 3 In Example 1, the viscosity was 40
The amount of dimethylpolysiloxane having a molecular chain at both ends of dimethylvinylsiloxy group of 0 mPa · s is 70.7 parts by weight, and the amount of dimethylpolysiloxane having a dimethylhydrogensiloxy group at both ends of molecular chain having a viscosity of 130 mPa · s is 27.
Silicone was prepared in the same manner as in Example 1 except that the blending amount of the dimethylpolysiloxane / methylhydrogenpolysiloxane copolymer having a trimethylsiloxy group at both ends of the molecular chain having a viscosity of 20 mPa · s was 2.3 parts by weight. A gel suspension was prepared. Table 1 shows the average particle size, stability, and characteristics of the silicone gel obtained by removing water from the suspension.

Example 4 In Example 1, the viscosity was 40
The compounding amount of the dimethylpolysiloxane blocked with dimethylvinylsiloxy group at both ends of the molecular chain of 0 mPa · s is 71.2 parts by weight, and the compounding amount of dimethylpolysiloxane blocked with dimethylhydrogensiloxy group at both ends of the molecular chain having a viscosity of 130 mPa · s is 2
The amount of the dimethylpolysiloxane / methylhydrogenpolysiloxane copolymer having 6.6 parts by weight and a viscosity of 20 mPa · s and both ends of a molecular chain having a trimethylsiloxy group blocked, is 2.
A silicone gel suspension was prepared in the same manner as in Example 1 except that the amount was 2 parts by weight. Table 1 shows the average particle size, stability, and characteristics of the silicone gel obtained by removing water from the suspension.

[0027]

[Table 1]

[Comparative Example 1] 68 parts by weight of a dimethylpolysiloxane having a dimethylvinylsiloxy group at both ends of a molecular chain having a viscosity of 400 mPa · s (vinyl group content = 0.48% by weight),
30.5 parts by weight of dimethylpolysiloxane blocked with dimethylhydrogensiloxy group at both ends of molecular chain having a viscosity of 130 mPa · s (content of silicon-bonded hydrogen atoms = 0.025% by weight), and both ends of molecular chain having a viscosity of 20 mPa · s 1.5 parts by weight of a trimethylsiloxy group-blocked dimethylpolysiloxane / methylhydrogenpolysiloxane copolymer (content of silicon-bonded hydrogen atoms = 0.14% by weight) was mixed and cooled to -10 ° C. , Platinum 1,3-divinyl-
Isopropanol solution of tetramethyldisiloxane complex
(Platinum metal concentration = 0.10% by weight) was uniformly mixed with the total weight of the organopolysiloxane so that the platinum metal concentration became 20 ppm by weight to obtain a hydrosilylation reaction-curable silicone gel composition. Once prepared, the composition was cured by standing at room temperature for one week to form a silicone gel. Table 2 shows the properties of this silicone gel. 100 parts by weight of this silicone gel is 3% by weight
Polyoxyethylene nonyl phenyl ether (HLB =
13.1) I tried to stir and mix 30 parts by weight of aqueous solution.
This silicone gel suspension could not be prepared.

[Comparative Example 2] 68 parts by weight of dimethylpolysiloxane having a viscosity of 400 mPa · s and dimethylvinylsiloxy groups at both ends of the molecular chain (vinyl group content = 0.48% by weight),
30.5 parts by weight of dimethylpolysiloxane blocked with dimethylhydrogensiloxy group at both ends of molecular chain having a viscosity of 130 mPa · s (content of silicon-bonded hydrogen atoms = 0.025% by weight), and both ends of molecular chain having a viscosity of 20 mPa · s 1.5 parts by weight of a trimethylsiloxy group-blocked dimethylpolysiloxane / methylhydrogenpolysiloxane copolymer (content of silicon-bonded hydrogen atoms = 0.14% by weight) was mixed and cooled to -10 ° C. , Platinum 1,3-divinyl-
Isopropanol solution of tetramethyldisiloxane complex
(Platinum metal concentration = 0.10% by weight) is expressed by 2 weight units of platinum metal with respect to the total weight of the organopolysiloxane.
An amount of 0 ppm was uniformly mixed to prepare a hydrosilylation reaction-curable silicone gel composition, and the composition was poured into a 3% by weight aqueous solution of 3% by weight polyoxyethylene nonylphenyl ether (HLB = 13.1) aqueous solution from a syringe. A silicone gel suspension was prepared by dropping the mixture in hot water at ℃.
When this silicone gel suspension was allowed to stand,
The silicone gel particles floated on the water surface and separated.
The moisture concentration was measured using a silicone gel suspension that was forcibly stirred. Table 2 shows the characteristics of the silicone gel suspension and the characteristics of the silicone gel obtained by removing water from the suspension.

[Comparative Example 3] 68 parts by weight of a dimethylpolysiloxane (vinyl group content = 0.48% by weight) having both ends of a dimethylvinylsiloxy group-blocked molecular chain having a viscosity of 400 mPa · s and a molecular chain having a viscosity of 130 mPa · s Dimethylhydrogensiloxy group-blocked dimethylpolysiloxane at both ends (content of silicon-bonded hydrogen atoms = 0.025% by weight) 30.5
1.5 parts by weight of a dimethylpolysiloxane / methylhydrogenpolysiloxane copolymer (both containing silicon-bonded hydrogen atoms = 0.14% by weight) having a trimethylsiloxy group at both ends of the molecular chain having a viscosity of 20 mPa · s , And 100 parts by weight of a 3% by weight aqueous solution of polyoxyethylene nonylphenyl ether (HLB = 13.1) was added thereto, and the mixture was emulsified with a homomixer to obtain a hydrosilylation reaction curing catalyst free of a hydrosilylation reaction catalyst. An emulsion of the silicone gel composition was prepared.

Next, an isopropanol solution of platinum chloride (platinum metal concentration: 0.1% by weight) is added to the above emulsion in an amount such that the platinum metal concentration becomes 20 ppm by weight based on the total weight of the organopolysiloxane. Was uniformly mixed. The characteristics of the emulsion of the hydrosilylation reaction-curable silicone gel composition and the
Table 2 shows the properties of the silicone gels obtained by heating in hot air at ℃.

[0032]

[Table 2] * The average particle size of Comparative Example 3 indicates the average particle size of the silicone gel composition.

[0033]

According to the silicone gel suspension of the present invention, silicone gel particles are dispersed in an aqueous solution of a surfactant, the workability is good, and the silicone gel particles are aggregated by removing water. It is characterized by forming a silicone gel having excellent viscoelasticity, and the method for producing a silicone gel suspension of the present invention is characterized in that such a silicone gel suspension can be prepared.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Konan 2-2 Chikusa Beach, Ichihara-shi, Chiba Prefecture Toray Dow Corning Silicone Co., Ltd. 2 Toray Dow Corning Silicone Co., Ltd. Research and Development Division F-term (reference) 4J002 CP041 CP121 DE197 EZ007 FD157 FD316 HA06

Claims (6)

[Claims] 1. An aqueous surfactant solution having an average particle size of 0.5.
A silicone gel suspension, wherein silicone gel particles of 1 to 100 μm are dispersed. 2. A 1/4 consistency of a silicone gel obtained by assembling silicone gel particles by removing water.
2. The silicone gel suspension according to claim 1, wherein (specified in JIS K 2220) is 10 to 200. 3. The value of dynamic viscoelasticity (tan δ) at 25 ° C., a strain rate of 10%, and a frequency of 1 rad / sec to 10 rad / sec of a silicone gel obtained by assembling silicone gel particles by removing water. The silicone gel suspension according to claim 1, wherein the number is 1 or more. 4. The method according to claim 1, wherein the silicone gel composition is dispersed in an aqueous surfactant solution so as to have an average particle diameter of 0.1 to 100 μm and cured. A method for producing a silicone gel suspension in which silicone gel particles having a particle size of 0.1 to 100 μm are dispersed. 5. The method for producing a silicone gel suspension according to claim 4, wherein the silicone gel composition is curable by a hydrosilylation reaction. 6. A silicone gel composition for curing a hydrosilylation reaction, which does not contain a catalyst for a hydrosilylation reaction, in an aqueous surfactant solution, having an average particle size of 0.1 to 100 μm.
The composition is cured by adding a hydrosilylation reaction catalyst to the dispersion, so that the average particle diameter is in a surfactant aqueous solution.
A method for producing a silicone gel suspension in which silicone gel particles of 1 to 100 μm are dispersed.