Organopolysiloxane, method for producing same, and composition containing organopolysiloxane

Abstract

Provided is an organopolysiloxane composition that maintains fluidity even when containing a large amount of a filler, that achieves favorable workability, and that inhibits oil bleeding.　Organopolysiloxane according to the present invention is a reaction product of organopolysiloxane represented by formula (5) and at least one alkoxysilane compound which contains organopolysiloxane represented by formula (6) and one or more alkoxy groups, or is a product of reaction between molecules of the organopolysiloxane represented by formula (5). An organopolysiloxane composition according to the present invention contains the organopolysiloxane and a filler. In formulae (5) and (6), R1 is independently a C1-12 saturated hydrocarbon group or hydrogen, R2 is independently a C1-12 saturated hydrocarbon group or a C6-12 aromatic hydrocarbon group, each Y is independently a C1-8 bivalent hydrocarbon group or oxygen, and each h is independently an integer of 1-400.

Description

Organopolysiloxane, method for producing the same, and composition containing organopolysiloxane

[0001] The present invention relates to an organopolysiloxane having a vinyl partial structure, which is a reaction product of an organopolysiloxane having a specific structure, and a method for producing the same. The present invention also relates to an organopolysiloxane composition that not only maintains fluidity and is easy to work with even when filled with a large amount of filler, but also inhibits oil bleeding.

[0002] Products using liquid media such as hydrocarbons, alkanols, alkenols, fatty acids, unsaturated fatty acids, esters of fatty acids and hydroxyl-containing compounds, esters of unsaturated fatty acids and hydroxyl-containing compounds, as well as silicone oils, acrylic resins, epoxy resins, and urethane resins include cosmetics, liquid toners, oil-based inkjet inks, weak solvent paints, lubricating oils, cleaning agents, thermally conductive materials, electrically conductive materials, and optical materials. These products are given functions according to their intended use by dispersing fillers such as pigments in the liquid media.

[0003] For example, in recent years, with the increasing density and integration of printed circuit boards and hybrid ICs equipped with electronic components such as transistors, ICs, and memory elements, and the increasing capacity of secondary batteries (cell type), resin compositions filled with thermally conductive fillers have been used as thermal conductive materials for heat dissipation greases, heat dissipation sheets, and other applications to efficiently dissipate heat generated by electronic and electrical devices such as electronic components and batteries. Thermally conductive organopolysiloxane compositions comprising an organopolysiloxane and a thermally conductive filler such as aluminum oxide powder or zinc oxide powder have been widely used as resin compositions. Furthermore, in order to accommodate particularly high heat dissipation rates, thermally conductive organopolysiloxane compositions filled with a large amount of thermally conductive filler have been proposed. However, increasing the filling rate of the thermally conductive filler to reduce thermal resistance or improve thermal conductivity for efficient heat dissipation increases the viscosity of the resin composition, making it difficult to discharge the resin composition. Therefore, various combinations of thermally conductive fillers have been investigated to achieve both high heat dissipation performance and fluidity (see Patent Documents 1, 2, and 3). However, the combinations of thermally conductive fillers investigated to date have either been insufficient in terms of thermal conductivity, or have high thermal conductivity but high viscosity and poor fluidity, and no combinations have been able to achieve both. Furthermore, increasing the filling rate of the thermally conductive filler significantly reduces the fluidity of the resin composition used in the thermal conductive material, making it difficult to dispense or apply the resin composition. This not only makes it difficult to conform to the fine irregularities on the surfaces of electronic components and heat sinks, but also increases contact thermal resistance.

[0004] One known method for solving this problem is to use (or add) a dispersant to the resin composition to improve the dispersibility of the thermally conductive filler (see Patent Document 4). However, when a dispersant or other additive is used, it may be liberated from the resin composition during use, causing oil bleeding, and improvements have been sought. The occurrence of oil bleeding can lead to poor electrical conductivity due to contamination of electronic components or contact failure.

[0005] JP 2005-054099 A JP 2004-091743 A JP 2000-063873 A International Publication No. 2022-107558

[0006] An object of the present invention is to provide an organopolysiloxane composition that not only maintains fluidity and has good workability even when filled with a large amount of filler, but also inhibits oil bleeding, and to provide an organopolysiloxane for use in such an organopolysiloxane composition, and a method for producing the same.

[0007] As a result of intensive research aimed at solving the above problems, the present inventors have found that an organopolysiloxane composition containing a filler and an organopolysiloxane that is a reaction product of an organopolysiloxane represented by formula (5) and a specific organopolysiloxane, or an intermolecular reaction product of an organopolysiloxane represented by formula (5), is useful, and have thus completed the present invention.

[0008] According to the present invention, the following organopolysiloxanes, methods for producing the same, and compositions thereof are provided. The present invention includes the following items: Item 1. An organopolysiloxane which is a reaction product of an organopolysiloxane represented by formula (5) with at least one selected from an organopolysiloxane represented by formula (6) and an alkoxysilane compound having one or more alkoxy groups, or an intermolecular reaction product of an organopolysiloxane represented by formula (5). In formula (5) and formula (6), R １ are independently a saturated hydrocarbon group having 1 to 12 carbon atoms or hydrogen, and R ２are independently a saturated hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, Y is independently a divalent hydrocarbon group having 1 to 8 carbon atoms or oxygen, and h is independently an integer of 1 to 400. Item 2. The organopolysiloxane according to Item 1, which is a reaction product of an organopolysiloxane represented by formula (5) with at least one selected from an organopolysiloxane represented by formula (6) and an alkoxysilane compound having one or more alkoxy groups. Item 3. The organopolysiloxane according to Item 1, which is an intermolecular reaction product of an organopolysiloxane represented by formula (5). Item 4. The organopolysiloxane according to any one of Items 1 to 3, which is represented by formula (1) or formula (2). In formulas (1) and (2), R １ are independently a saturated hydrocarbon group having 1 to 12 carbon atoms or hydrogen, X is independently acryloyl, alkyl, carboxyl, vinyl, methacryloyl, aryl, amino, isocyanate, isocyanuric, epoxy, hydroxyl, mercapto, or a monovalent group having any of the above atomic groups, a group represented by formula (3), or a group represented by formula (4), at least one X is a group represented by formula (3), m, l, and k are independently integers of 0 to 10, and j is an integer of 1 to 10; In formula (3) and formula (4), R ２are independently a saturated hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, Y is independently a divalent hydrocarbon group having 1 to 8 carbon atoms or oxygen, and h is independently an integer of 1 to 400. Item 5. The organopolysiloxane according to any one of Items 1 to 4, having a number average molecular weight (Mn) of 500 to 300,000. Item 6. A method for producing an organopolysiloxane according to Item 2, comprising reacting an organopolysiloxane represented by formula (5) with at least one selected from organopolysiloxanes represented by formula (6) and alkoxysilane compounds having one or more alkoxy groups. Item 7. A method for producing an organopolysiloxane according to Item 3, comprising reacting an organopolysiloxane represented by formula (5) with an alkoxysilane compound having at least one alkoxy group. Item 8. A method for producing an organopolysiloxane according to Item 6 or 7, wherein an organometallic catalyst is used as a catalyst in the reaction. Item 9. A method for using the organopolysiloxane according to any one of Items 1 to 5, which is used to disperse a filler in a liquid medium. Item 10. An organopolysiloxane composition containing the organopolysiloxane (A) according to any one of Items 1 to 5, and a filler (B). Item 11. The organopolysiloxane composition according to Item 10, which further contains a liquid medium (C).

[0009] The organopolysiloxane composition of the present invention maintains its fluidity even when filled with a large amount of thermally conductive filler, resulting in excellent workability. It also inhibits oil bleeding, preventing electrical conductivity problems due to contamination of electronic components and contact failure.

[0010] 1 is a conceptual diagram of an oil-bleed evaluation test. 2 is a graph showing the shear viscosity when the shear rate is changed for the organopolysiloxane compositions of Example 6 and Comparative Examples 2 and 3.

[0011] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments.

[0012] <Organopolysiloxane of the Present Invention> The organopolysiloxane of the present invention is a reaction product of an organopolysiloxane represented by formula (5) with at least one selected from an organopolysiloxane represented by formula (6) and an alkoxysilane compound having one or more alkoxy groups, or an intermolecular reaction product of an organopolysiloxane represented by formula (5). In formula (5) and formula (6), R １ are independently a saturated hydrocarbon group having 1 to 12 carbon atoms or hydrogen, and R ２ are independently a saturated hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms. Y is independently a divalent hydrocarbon group having 1 to 8 carbon atoms or oxygen. h is independently an integer from 1 to 400. When using at least one selected from the organopolysiloxane represented by formula (5), the organopolysiloxane represented by formula (6), and an alkoxysilane compound having one or more alkoxy groups, the organopolysiloxane represented by formula (5) is preferably 1 part by mass or more, and more preferably 10 parts by mass or more, relative to 100 mass of the total amount of the organopolysiloxane represented by formula (5), the organopolysiloxane represented by formula (6), and the alkoxysilane compound having one or more alkoxy groups.

[0013] The alkoxysilane compound having one or more alkoxy groups is a monoalkoxysilane compound, a dialkoxysilane compound, or a trialkoxysilane compound other than the organopolysiloxane represented by formula (5) or formula (6).

[0014] Examples of the monoalkoxysilane compound that can be used include alkyl-containing monoalkoxysilane compounds, vinyl-containing monoalkoxysilane compounds, acryloyl-containing monoalkoxysilane compounds, methacryloyl-containing monoalkoxysilane compounds, aromatic group-containing monoalkoxysilane compounds, amino-containing monoalkoxysilane compounds, isocyanate-containing monoalkoxysilane compounds, isocyanurate-containing monoalkoxysilane compounds, epoxy-containing monoalkoxysilane compounds, and mercapto-containing monoalkoxysilane compounds.

[0015] Examples of the dialkoxysilane compound that can be used include alkyl-containing dialkoxysilane compounds, vinyl-containing dialkoxysilane compounds, acryloyl-containing dialkoxysilane compounds, methacryloyl-containing dialkoxysilane compounds, aromatic group-containing dialkoxysilane compounds, amino-containing dialkoxysilane compounds, isocyanate-containing dialkoxysilane compounds, isocyanurate-containing dialkoxysilane compounds, epoxy-containing dialkoxysilane compounds, and mercapto-containing dialkoxysilane compounds.

[0016] Examples of trialkoxysilane compounds that can be used include alkyl-containing trialkoxysilane compounds, vinyl-containing trialkoxysilane compounds, acryloyl-containing trialkoxysilane compounds, methacryloyl-containing trialkoxysilane compounds, aromatic group-containing trialkoxysilane compounds, amino-containing trialkoxysilane compounds, isocyanate-containing trialkoxysilane compounds, isocyanurate-containing trialkoxysilane compounds, epoxy-containing trialkoxysilane compounds, and mercapto-containing trialkoxysilane compounds.

[0017] Of these, trialkoxysilane compounds are more preferred because the resulting organopolysiloxane contains more alkoxy groups and hydroxyl groups, which strengthens the interaction with the filler.

[0018] The organopolysiloxane of the present invention is characterized by having a vinyl partial structure derived from formula (5). Although a mixture of different structures is produced, when an organopolysiloxane represented by formula (5) or an organopolysiloxane represented by formula (5) and at least one selected from an organopolysiloxane represented by formula (6) and a trialkoxysilane compound is used, an organopolysiloxane represented by formula (1) or formula (2) is mainly produced. In formula (1) and formula (2), R １are independently a saturated hydrocarbon group having 1 to 12 carbon atoms or hydrogen; X is independently acryloyl, alkyl, carboxyl, vinyl, methacryloyl, aryl, amino, isocyanate, isocyanuric, epoxy, hydroxyl, mercapto, or a monovalent group having any of the above atomic groups, a group represented by formula (3), or a group represented by formula (4); at least one X is a group represented by formula (3); m, l, and k are independently 0 to 10; and j is 1 to 10.

[0019] In formula (3) and formula (4), R ２ are independently a saturated hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms; Y is independently a divalent hydrocarbon group having 1 to 8 carbon atoms or oxygen; and h is independently an integer from 1 to 400.

[0020] The group represented by formula (3) in X in formula (1) and formula (2) is derived from formula (5), the group represented by formula (4) is derived from formula (6), and acryloyl, alkyl, carboxyl, vinyl, methacryloyl, aromatic group, amino, isocyanate, isocyanurate, epoxy, hydroxyl, mercapto, or a monovalent group having any of the above atomic groups is derived from the trialkoxysilane compound used.

[0021] The atomic group in the present invention is a group selected from acryloyl, alkyl, carboxyl, vinyl, methacryloyl, aryl, amino, isocyanate, isocyanuric, epoxy, hydroxyl, or mercapto, and is directly bonded to a Si atom. Also, the monovalent group having an atomic group is a group in which a group selected from the above atomic group is bonded to a Si atom via a divalent group, and the divalent group is a group selected from alkylene, alkylcycloalkylene, alkylenephenylene, alkylphenylene, or alkylphenylalkylene.

[0022] The organopolysiloxane of the present invention is used as component (A) of the organopolysiloxane composition described below. The organopolysiloxane of the present invention has vinyl groups, and when used in the organopolysiloxane composition, it reacts with the liquid medium to cure, thereby suppressing oil bleeding. In addition, it has multiple adsorption points (-OR １ ) and is thought to have good filler dispersibility. Furthermore, by adsorbing to the filler and reacting with the liquid medium, it is expected to have the effect of preventing cracks from the interface between the filler and the liquid medium, and by increasing the crosslink density, it is expected to have the effect of improving the mechanical properties after curing.

[0023] <Method for Producing the Organopolysiloxane of the Present Invention> The organopolysiloxane of the present invention can be obtained by an intermolecular reaction of an organopolysiloxane having an alkoxysilyl group at one end and a vinyl group at the other end, as represented by formula (5), or can be synthesized from an organopolysiloxane represented by formula (5) and at least one selected from an organopolysiloxane having a trialkoxysilyl group at one end, as represented by formula (6), and an alkoxysilane compound having one or more alkoxy groups.

[0024] In formula (5) and formula (6), R １ are independently a saturated hydrocarbon group having 1 to 12 carbon atoms or hydrogen, and R ２ are independently a saturated hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms. Y is independently a divalent hydrocarbon group having 1 to 8 carbon atoms or oxygen. h is independently an integer from 1 to 400.

[0025] A solvent can be used in the reaction if necessary, and as a catalyst, an acid catalyst such as hydrochloric acid for the purpose of hydrolysis, an alkali catalyst such as ammonia, etc. can also be used, but it is preferable to use an organometallic catalyst.

[0026] The reaction product of the organopolysiloxane represented by formula (5) with at least one selected from the group consisting of the organopolysiloxane represented by formula (6) and an alkoxysilane compound having one or more alkoxy groups may also contain an intermolecular reaction product of the organopolysiloxane represented by formula (5).

[0027] The organopolysiloxane represented by formula (5) and the organopolysiloxane represented by formula (6) may be used singly or in combination of two or more.

[0028] For the organopolysiloxane represented by formula (5) and the organopolysiloxane represented by formula (6), examples of the trialkoxysilyl include trimethoxysilyl, triethoxysilyl, tripropoxysilyl, etc. Among these, trimethoxysilyl is preferred from the viewpoints of the affinity between the organopolysiloxane of the present invention to be synthesized and the filler, and the ease of obtaining vinylalkoxysilane, which is a raw material for producing the organopolysiloxane represented by formula (5) and the organopolysiloxane represented by formula (6).

[0029] The alkoxysilane compound having one or more alkoxy groups can be used alone or in combination. As the alkoxysilane compound having one or more alkoxy groups, as described above, monoalkoxysilane compounds, dialkoxysilane compounds, and trialkoxysilane compounds containing alkyl, vinyl, acryloyl, methacryloyl, aromatic groups, amino, isocyanate, isocyanurate, epoxy, or mercapto can be used. More specific examples of trialkoxysilane compounds are listed below.

[0030] Examples of alkyl-containing trialkoxysilane compounds include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, n-octyltriethoxysilane, and n-decyltrimethoxysilane. Examples of vinyl-containing trialkoxysilane compounds include vinyltrimethoxysilane and vinyltriethoxysilane. Examples of acryloyl-containing trialkoxysilane compounds include 3-acryloxypropyltrimethoxysilane. Examples of methacryloyl-containing trialkoxysilane compounds include 3-methacryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane. Examples of aromatic group-containing trialkoxysilane compounds include phenyltrimethoxysilane and phenyltriethoxysilane. Examples of amino-containing trialkoxysilane compounds include N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane. Examples of isocyanate-containing trialkoxysilane compounds include 3-isocyanatepropyltriethoxysilane. Examples of isocyanurate-containing trialkoxysilane compounds include tris-(trimethoxysilylpropyl)isocyanurate. Examples of epoxy-containing trialkoxysilane compounds include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropyltriethoxysilane. Examples of mercapto-containing trialkoxysilane compounds include 3-mercaptopropyltrimethoxysilane.

[0031] The solvent may be one or more selected from nonpolar and polar solvents. Nonpolar solvents include, for example, hydrocarbons such as n-hexane, n-heptane, and isooctane, and aromatic hydrocarbons such as toluene and xylene. Polar solvents include, for example, water; alcohols such as methanol, ethanol, and isopropanol; alcohol esters; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; ethers such as diethyl ether, dibutyl ether, and tetrahydrofuran; esters such as ethyl acetate, isopropyl acetate, and butyl acetate; cyanide hydrocarbons such as acetonitrile; amines; amides such as acetamide; halogenated hydrocarbons such as methylene chloride, chloroform, and hexafluorometa-xylene; and sulfur-containing compounds such as dimethyl sulfoxide. The amount of solvent used is not particularly limited and can be adjusted as appropriate. Typically, the amount used is such that the concentration of the organosilicon compound to be reacted is 5 to 95% by mass, preferably 20 to 80% by mass. The reaction in the production method of the present invention can also be carried out without a solvent.

[0032] As the organometallic catalyst, organotin compounds such as dibutyltin dilaurate and dibutyltin di-2-ethylhexoate, and organometallic compounds based on bismuth, zinc, or zirconium can be used, but titanium alkoxide compounds are preferred. Examples of titanium alkoxide compounds include tetra(2-ethylhexyl)titanate, titanium tetra-n-butoxide, titanium tetraisopropoxide, titanium diisopropoxybis(ethylacetoacetate), titanium tetraacetylacetonate, titanium di-2-ethylhexoxybis(2-ethyl-3-hydroxyhexoxide), and titanium diisopropoxybis(acetylacetonate). The catalytic amount of titanium alkoxide compound can be 0.1 to 10 parts by weight per 100 parts by weight of the organosilicon compound to be reacted. If the catalytic amount of titanium alkoxide compound is too small, the reaction will not be completed, while if it is too large, problems such as yellowing may occur.

[0033] The organopolysiloxane dispersant of the present invention has a number average molecular weight (Mn) measured by gel permeation chromatography (GPC) of 500 to 300,000, more preferably 3,000 to 200,000, and even more preferably 5,000 to 100,000. If the molecular weight is too small, the steric repulsion generated when the filler is dispersed is not exerted, and a stable dispersion cannot be obtained. On the other hand, if the molecular weight is too large, the wettability with the filler becomes insufficient, resulting in an increase in the viscosity of the dispersion.

[0034] The organopolysiloxane of the present invention can have a desired number average molecular weight (Mn) by appropriately adjusting the number average molecular weights and amounts of the organopolysiloxane represented by formula (5) and the organopolysiloxane represented by formula (6) used in the reaction.

[0035] <Organopolysiloxane Composition> The organopolysiloxane of the present invention is used to provide an organopolysiloxane composition that not only maintains fluidity and has good workability even when filled with a large amount of filler, but also inhibits oil bleeding.

[0036] The organopolysiloxane composition of the present invention contains, as component (A), an organopolysiloxane for dispersing a filler, and as component (B), a filler. It also contains, as component (C), a liquid medium. The organopolysiloxane composition of the present invention uses the organopolysiloxane of the present invention as component (A).

[0037] <Filler; Component (B)> Examples of fillers include inorganic pigments, organic pigments, extender pigments, fillers, inorganic fine particles, diamond, graphene, graphite, carbon black, carbon nanotubes, clay, conductive fillers, thermally conductive agents, carbon fibers, glass fibers, cellulose, and cellulose nanofibers. These fillers are particulate, powdery, or fibrous substances added to plastics, rubber, paints, inks, etc. to improve strength and functionality and reduce costs. The crystal form, particle size, surface condition, and presence or absence of surface treatment of the filler are not particularly limited. The filler (thermal conductive agent) of the thermally conductive material is preferably aluminum oxide, zinc oxide, aluminum nitride, or boron nitride, and more preferably aluminum oxide.

[0038] <Liquid Medium; Component (C)> The liquid medium is used for purposes such as viscosity adjustment and curing. Examples of the liquid medium include hydrocarbons, alkanols, alkenols, fatty acids, unsaturated fatty acids, esters of fatty acids and hydroxyl group-containing compounds, esters of unsaturated fatty acids and hydroxyl group-containing compounds, silicone oils, acrylic resins, epoxy resins, and urethane resins. These liquid media can be used alone or in combination of two or more. Silicone oil is a liquid medium suitable for use as a thermally conductive material.

[0039] Examples of hydrocarbons include hexane, hexene, 2-ethylhexane, heptane, heptene, cyclohexane, cyclohexaneheptane, octane, octene, 2-ethylhexane, nonane, decane, isodecane, dodecane, isododecane, tridecane, undecane, octadecane, C8-20 isoparaffin, squalane, petrolatum, microcrystalline wax, hydrogenated polyisobutene, 1-octene, 2-octene, 1-nonene, 2-nonene, 1-decene cyclohexane, 2-decene, 1-undecene, 2-undecene, 1-dodecene, 2-dodecene, 1-tridecene, 2-tridecene, 1-tetradecene, 2-tetradecene, 1-pentadecene, 2-pentadecene, 1-hexadecene, 2-hexadecene, 1-heptadecene, 2-heptadecene, 1-octadecene, 2-octadecene, dimethylcyclohexane, trimethylcyclohexane, ethylcyclohexane, propylcyclohexane, and the like.

[0040] Examples of alkanols and alkenols include octanol, 2-ethylhexanol, nonanol, decanol, isodecanol, dodecanol, cetyl alcohol, stearyl alcohol, arachyl alcohol, behenyl alcohol, hexyldecanol, octyldodecanol, isocetyl alcohol, isostearyl alcohol, and oleyl alcohol.

[0041] Examples of fatty acids and unsaturated fatty acids include octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, tridecanoic acid, stearic acid, oleic acid, 1,2-hydroxystearic acid, ricinoleic acid, ricinoleic acid, undecylenic acid, isononanoic acid, myristic acid, palmitic acid, myristic acid, and 2-ethylhexanoic acid.

[0042] Examples of esters of fatty acids and hydroxyl group-containing compounds, and esters of unsaturated fatty acids and hydroxyl group-containing compounds include methyl laurate, heptyl undecylenate, isononyl isononanoate, ethyl oleate, isopropyl myristate, isopropyl palmitate, butyl stearate, cetyl palmitate, myristyl myristate, octyldodecyl myristate, isopropyl isostearate, ethyl isostearate, cetyl 2-ethylhexanoate, hexyl isostearate, ethylene glycol di-2-ethylhexanoate, ethylene glycol dioleate, propylene glycol di(capryl-caprate), propylene glycol dioleate, trimethylolpropane triisostearate, pentaerythritol tetra-2-ethylhexanoate, neopentyl glycol diheptanoate, isocetyl isostearate, 2-dimethyloctanoate ... Examples of fatty acids include octyldodecyl, myristyl lactate, trioctyldodecyl citrate, diisostearyl malate, di-2-ethylhexyl succinate, diisopropyl adipate, diisobutyl adipate, and cholesteryl stearate. Further examples include triesters with glycerin, such as almond oil, avocado oil, olive oil, shea butter, shea butter oil, evening primrose oil, passionflower seed oil, camellia oil, babassu oil, peanut oil, and rosehip oil; and waxes, such as beeswax, Japan wax, jojoba oil, candelilla wax, and carnauba wax.

[0043] Examples of silicone oils include dimethyl silicone oil, methylphenyl silicone oil, methylhydrogen silicone oil, amino-modified silicone oil, epoxy-modified silicone oil, carboxy-modified silicone oil, carbinol-modified silicone oil, polyether-modified silicone oil, alkyl-modified silicone oil, and fluorine-modified silicone oil.

[0044] Examples of acrylic resins include monofunctional (meth)acrylates, difunctional (meth)acrylates, trifunctional or higher polyfunctional (meth)acrylates, epoxy (meth)acrylates, urethane (meth)acrylates, and difunctional or higher polyester (meth)acrylates.

[0045] Examples of epoxy resins include combinations of a base resin, such as phenolic glycidyl ethers (e.g., bisphenol A, bisphenol F, and phenol novolac), or alcoholic glycidyl ethers (e.g., polypropylene glycol), with a curing agent. Examples of curing agents include amine compounds such as aliphatic polyamines, modified aliphatic polyamines, polyamidoamines, polyamides, alicyclic polyamines, modified alicyclic polyamines, modified aromatic polyamines, and tertiary amines. These curing agents may be used alone or in combination of two or more. A reaction accelerator may also be used to accelerate the reaction between the base resin and the curing agent. Examples of reaction accelerators include phenol, p-t-butylphenol, di-t-butylphenol, cresol, triphenyl phosphite, salicylic acid, and triethanolamine. These reaction accelerators may be used alone or in combination of two or more.

[0046] Examples of urethane resins include reaction products of hydroxyl group-containing compounds and polyisocyanate compounds, such as linear multi-block copolymers of polyurethane obtained by reacting a short-chain glycol or short-chain ether with an isocyanate compound as a hard segment and a long-chain glycol or long-chain ether with an isocyanate compound as a soft segment, and reaction products (cured products) of urethane prepolymers and polyisocyanate compounds.

[0047] The organopolysiloxane composition of the present invention preferably uses a liquid medium having reactive groups for curing. Because the organopolysiloxane of the present invention has vinyl groups, it is believed that when the composition is prepared, the reaction between component (A) and component (C) can suppress oil bleeding.

[0048] As the liquid medium, silicone oil is preferably used, and silicone oil having a reactive group is more preferably used. The curing mechanism is not particularly limited, and examples include hydrosilylation reaction, condensation reaction, and free radical reaction by organic peroxide. Among these, the hydrosilylation reaction is preferred as the curing mechanism because it cures quickly and does not generate by-products. Curing occurs through reaction between the vinyl group of component (A) and the Si-H group (a group in which hydrogen is bonded to silicon) of the silicone oil. When using a hydrosilylation reaction, for example, an alkenyl-modified polysiloxane having an average of two or more alkenyl bonds per molecule, a silicon compound having an average of two or more silicon-hydrogen bonds per molecule, and a platinum-based catalyst can be used. Commercially available two-component heat-curable liquid silicones that can be used include TSE3033 manufactured by Momentive Corporation and CY52-276 manufactured by Dow Toray.

[0049] The filler-containing organopolysiloxane composition preferably contains 0.1 to 50 parts by mass, and more preferably 0.5 to 20 parts by mass, of component (A) per 100 parts by mass of filler, and the filler-containing organopolysiloxane composition preferably contains 0 to 50 parts by mass, and more preferably 5 to 30 parts by mass of the liquid medium per 100 parts by mass of filler.

[0050] The organopolysiloxane composition of the present invention can contain various additives such as surfactants, plasticizers, and antifoaming agents, provided that the intended purpose of the composition is not impaired.

[0051] The organopolysiloxane composition of the present invention can be cured to obtain a heat dissipation sheet.

[0052] The heat dissipation sheet is used by being interposed between an electronic component and a cooling member inside an electronic device, etc., and efficiently conducts heat generated by the electronic component to the cooling member. Specific examples of electronic components include a CPU, a power amplifier, and a power supply. Specific examples of cooling members include a heat sink.

[0053] The organopolysiloxane composition of the present invention can be produced in accordance with known methods for producing filler dispersions. Examples include a method in which a filler is added to a liquid medium containing component (A) and then stirred and mixed, or a method in which the liquid medium and component (A) are added to the filler and then stirred and mixed. Known dispersing machines can be used as dispersing equipment for stirring, mixing, or dispersion. Examples include roll mills, ball mills, bead mills, sand mills, homogenizers, dispersers, and planetary mixers. Dispersion treatment can also be carried out in an ultrasonic bath.

[0054] The present invention will be described in more detail below. In the examples, "parts" and "%" are all by mass (parts by mass, % by mass) unless otherwise specified. The present invention is not limited to these examples.

[0055] <Measurement of Molecular Weight> The molecular weight of the organopolysiloxane was measured by gel permeation chromatography (GPC). The formation of the organopolysiloxane of the present invention can be confirmed by the fact that the weight average molecular weight (Mw) and number average molecular weight (Mn) calculated by GPC measurement are greater than those of the raw organopolysiloxane. Polystyrene was used as a standard sample in the GPC measurement, and the molecular weight was measured in terms of polystyrene. The measurement of the molecular weight in terms of polystyrene by the GPC method was carried out under the following measurement conditions: a) Measuring equipment: JASCO HPLC LC-2000Plus series b) Column: Shodex KF-804L x 2 c) Oven temperature: 40°C d) Eluent: toluene 0.7 mL / min e) Standard sample: polystyrene f) Injection amount: 20 μL g) Concentration: 0.05 g / 10 mL h) Sample preparation: Toluene was used as a solvent and the sample was dissolved by stirring at room temperature.

[0056] Example 1 Organopolysiloxane A1 was synthesized by the following procedure: 23.8 g of the organopolysiloxane represented by formula (5-1) (number average molecular weight (Mn) = 4,200, weight average molecular weight (Mw) = 5,400), 51.7 g of the organopolysiloxane represented by formula (6-1) (number average molecular weight (Mn) = 3,100, weight average molecular weight (Mw) = 3,400), and 0.68 g of tetra(2-ethylhexyl) titanate (Fujifilm Wako Pure Chemical Industries, Ltd., molecular weight = 564.8) were weighed into a 300 ml four-neck flask equipped with a stirrer, thermometer, and reflux condenser, and the mixture was heated to 60 to 70°C with stirring under a nitrogen atmosphere. Subsequently, a mixture of 50.0 g of tetrahydrofuran and 6.18 g of water was fed to the mixture at 60-70°C over 4 hours and stirred at 60-70°C for 5 hours. The mixture was then transferred to a 300 ml four-neck flask equipped with a stirrer, thermometer, collection flask, and distillation head, and heated to 120°C under reduced pressure of 0.2 kPaA using a vacuum pump to distill off any remaining volatile substances. 66.9 g of a pale yellow, transparent liquid was obtained from the flask. GPC: number average molecular weight (Mn) = 15,000, weight average molecular weight (Mw) = 49,700.

[0057] The number average molecular weight (Mn) and weight average molecular weight (Mw) of the resulting pale yellow, transparent liquid were greater than those of the raw material organopolysiloxane represented by formula (5-1) and the organopolysiloxane represented by formula (6-1), and therefore it was determined that the reaction product, the organopolysiloxane of the present invention, had been obtained.

[0058] Example 2 Organopolysiloxane A2 was synthesized according to the following procedure. 35.0 g of organopolysiloxane represented by formula (5-1) (number average molecular weight (Mn) = 4,200, weight average molecular weight (Mw) = 5,400), 1.6 g of hexyltrimethoxysilane (formula (9)), and 0.22 g of tetra(2-ethylhexyl) titanate (Fujifilm Wako Pure Chemical Industries, Ltd., molecular weight = 564.8) were weighed into a 200 ml four-neck flask equipped with a stirrer, thermometer, and reflux condenser, and the mixture was heated to 60-70°C with stirring under a nitrogen atmosphere. Thereafter, a mixture of 37.0 g of tetrahydrofuran and 2.2 g of water was added over 1 hour at 60-70°C, followed by stirring at 60-70°C for 5 hours. The product was then transferred to a 200 ml four-neck flask equipped with a stirrer, thermometer, collection flask, and distillation head, and heated to 120°C under a reduced pressure of 0.2 kPaA using a vacuum pump to distill off any remaining volatile substances. 32.2 g of a pale yellow, transparent liquid was obtained. GPC: number average molecular weight (Mn) = 6,600, weight average molecular weight (Mw) = 21,000.

[0059] The number average molecular weight (Mn) and weight average molecular weight (Mw) of the resulting pale yellow, transparent liquid were greater than those of the raw material organopolysiloxane represented by formula (5-1), and therefore it was determined that the reaction product, the organopolysiloxane of the present invention, had been obtained.

[0060] Example 3 Organopolysiloxane A3 was synthesized according to the following procedure. 20.0 g of the organopolysiloxane represented by formula (5-2) (number average molecular weight (Mn) = 4,400, weight average molecular weight (Mw) = 5,600), 151.8 g of tetrahydrofuran, and 0.11 g of tetra(2-ethylhexyl) titanate were weighed into a 300 ml four-neck flask equipped with a stirrer, thermometer, and reflux condenser, and the mixture was heated to 40-50°C with stirring under a nitrogen atmosphere. Subsequently, a mixture of 8.2 g of tetrahydrofuran and 0.8 g of water was added over 2 hours and stirred at 50-60°C for 7 hours. The mixture was then transferred to a 300 ml four-neck flask equipped with a stirrer, thermometer, collection flask, and distillation head, and heated to 60°C under a reduced pressure of 0.2 kPaA using a vacuum pump to distill off any volatile substances remaining in the product. 18.2 g of a pale yellow transparent liquid remained in the flask. GPC: number average molecular weight (Mn) = 6,800, weight average molecular weight (Mw) = 14,300.

[0061] Example 4 Organopolysiloxane A4 was synthesized according to the following procedure. 20.0 g of the organopolysiloxane represented by formula (5-2) (number average molecular weight (Mn) = 14,800, weight average molecular weight (Mw) = 17,400), 151.8 g of tetrahydrofuran, and 0.03 g of tetra(2-ethylhexyl) titanate were weighed into a 300 ml four-neck flask equipped with a stirrer, thermometer, and reflux condenser, and the mixture was heated to 40-50°C with stirring under a nitrogen atmosphere. Subsequently, a mixture of 8.2 g of tetrahydrofuran and 0.3 g of water was added over 2 hours, and the mixture was stirred at 50-60°C for 7 hours. The product was then transferred to a 300 ml four-neck flask equipped with a stirrer, thermometer, collection flask, and distillation head, and heated to 60°C under a reduced pressure of 0.2 kPaA using a vacuum pump to distill off remaining volatile substances. 15.2 g of a pale yellow, transparent liquid was obtained. GPC: number average molecular weight (Mn) = 22,900, weight average molecular weight (Mw) = 42,000.

[0062] Example 5 Organopolysiloxane A5 was synthesized according to the following procedure. 15.0 g of an organopolysiloxane represented by formula (5-2) (number average molecular weight (Mn) = 4,400, weight average molecular weight (Mw) = 5,600), 7.5 g of an organopolysiloxane represented by formula (6-1) (number average molecular weight (Mn) = 3,100, weight average molecular weight (Mw) = 3,400), 169.6 g of tetrahydrofuran, and 0.11 g of tetra(2-ethylhexyl) titanate were weighed into a 300 ml four-neck flask equipped with a stirrer, thermometer, and reflux condenser. The mixture was heated to 40-50°C with stirring under a nitrogen atmosphere. Subsequently, a mixture of 10.6 g of tetrahydrofuran and 1.0 g of water was added over 2 hours and stirred at 50-60°C for 8 hours. The product was then transferred to a 300 ml four-neck flask equipped with a stirrer, thermometer, collection flask, and distillation head, and heated to 60°C under a reduced pressure of 0.2 kPaA using a vacuum pump to distill off any remaining volatile substances. 17.7 g of a pale yellow, transparent liquid was obtained. GPC: number average molecular weight (Mn) = 6,700, weight average molecular weight (Mw) = 13,300.

[0063] Comparative Example 1 Organopolysiloxane A'1 was synthesized according to the following procedure. 74.8 g of the organopolysiloxane represented by formula (6-1) (number average molecular weight (Mn) = 3,100, weight average molecular weight (Mw) = 3,400) and 0.74 g of tetra(2-ethylhexyl) titanate (Fujifilm Wako Pure Chemical Industries, Ltd., molecular weight = 564.8) were weighed into a 300 ml four-neck flask equipped with a stirrer, thermometer, and reflux condenser, and the mixture was heated to 60-70°C with stirring under a nitrogen atmosphere. Subsequently, a mixture of 50.0 g of tetrahydrofuran and 6.77 g of water was added over 3 hours at 60-70°C, and the mixture was stirred at 60-70°C for 5 hours. The product was then transferred to a 300 ml four-neck flask equipped with a stirrer, thermometer, collection flask, and distillation head, and heated to 120°C under a reduced pressure of 0.2 kPaA using a vacuum pump to distill off any remaining volatile substances. 71.8 g of a pale yellow, transparent liquid was obtained. GPC: number average molecular weight (Mn) = 11,200, weight average molecular weight (Mw) = 16,200.

[0064]

[0065] The number-average molecular weight (Mn) and weight-average molecular weight (Mw) of the resulting pale yellow, transparent liquid were greater than those of the raw material organopolysiloxane represented by formula (6-1), and therefore it was determined that an organopolysiloxane, the reaction product, had been obtained. The organopolysiloxane obtained here did not have a vinyl partial structure and was used as component (A') for comparison with component (A) of the present invention.

[0066] Example 6 Preparation of Evaluation Sample Organopolysiloxane A1 was weighed into an ointment jar as component (A). Next, TSE3033A, a two-component heat-curing liquid silicone manufactured by Momentive, was weighed as component (C). Furthermore, aluminum oxide (DAW-10 manufactured by Denka Co., Ltd.) with an average diameter of 13 μm was weighed as component (B) and stirred with a spatula. Furthermore, TSE3033A and TSE3033B, two-component heat-curing liquid silicones manufactured by Momentive, were weighed as component (C). Organopolysiloxane A1, TSE3033A, TSE3033B, and aluminum oxide were weighed in the amounts shown in Table 1. Next, the mixture was kneaded using a Thinky Corporation Awatori Rentaro Vacuum Type (Model: ARV-310) at 1000 rpm under normal pressure for 2 minutes and then at 1000 rpm under reduced pressure for 1 minute to prepare a composition for evaluation.

[0067] <Evaluation of fluidity> The fluidity of the evaluation samples prepared as described above was evaluated by measuring the shear viscosity at different shear rates using a rheometer (MCR302, manufactured by Anton Paar) under the following conditions. The lower the shear viscosity at the same shear rate, the better the fluidity. Furthermore, a low shear viscosity when the same amount of filler is added also indicates good dispersibility. Plate shape: circular flat plate, 25 mm diameter Sample thickness: 0.5 mm Temperature: 25±1°C Shear rate: 0.001 to 100 s －１

[0068] <Oil-Bleed Evaluation> 0.6 g of the evaluation sample prepared as described above was applied to a frosted glass plate, sandwiched between two other glass plates to a thickness of 1 mm, and heat-cured at 150°C for 3 hours. The length of the oil bleed that had seeped out around the composition was measured, and the ratio to the width of the composition was calculated to evaluate the oil-bleed suppression effect. That is, using the lengths L1 and L2 in Figure 1, the bleed length ratio was calculated according to equation (12). A smaller ratio indicates a higher oil-bleed suppression effect. (Bleed length ratio) = (L1 - L2) / L2 (12) The results of the fluidity evaluation and oil-bleed evaluation of Example 6 are shown in Table 1 and Figure 1.

[0069] Comparative Example 2 An evaluation sample was prepared and evaluated in the same manner as in Example 6, except that organopolysiloxane A'1, which does not have a vinyl partial structure, was used as component (A') instead of organopolysiloxane A1, which was used as component (A).

[0070] Comparative Example 3 An evaluation sample was prepared in the same manner as in Example 6, except that the components (A) and (A') were not used, and evaluation was carried out.

[0071] Table 1 shows the compositions and evaluation results for Example 6 and Comparative Examples 2 and 3. Regarding the flowability evaluation results, Fig. 2 also shows the shear viscosity when the shear rate is changed.

[0072] Table 1. Composition and evaluation results

[0073] The organopolysiloxane of the present invention, which is a reaction product from the organopolysiloxane represented by formula (5), has a flowability evaluation of a composition at a shear rate of 0.001 to 10 s compared to a composition in which the organopolysiloxane represented by formula (5) was not used as a raw material. －１ As a result, the shear viscosity was kept low within this range, and it was confirmed that the fluidity was good. It was also confirmed that the oil bleeding of the composition was highly suppressed.

[0074] From the above, it can be concluded that the organopolysiloxane composition of the present invention is excellent in workability and in its ability to inhibit oil bleeding during use.

[0075] The organopolysiloxane of the present invention can be used as a dispersant for stably dispersing fillers in fields such as cosmetics, liquid developers, oil-based inkjet inks, ultraviolet-curable inkjet inks, weak-solvent paints, offset inks, lubricants, cleaning agents, insecticides, release agents, adhesives, thermally conductive materials, electrically conductive materials, optical materials, etc. The organopolysiloxane composition of the present invention can also be used as a thermally conductive material to be interposed between heat-generating electronic components such as transistors, IC chips, and memory elements and cooling members such as heat sinks.

Claims

1. An organopolysiloxane which is a reaction product of an organopolysiloxane represented by formula (5) with at least one selected from an organopolysiloxane represented by formula (6) and an alkoxysilane compound having one or more alkoxy groups, or an intermolecular reaction product of an organopolysiloxane represented by formula (5). In formula (5) and formula (6), R １ are independently a saturated hydrocarbon group having 1 to 12 carbon atoms or hydrogen, and R ２ are independently a saturated hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms; Y is independently a divalent hydrocarbon group having 1 to 8 carbon atoms or oxygen; and h is independently an integer from 1 to 400.

2. The organopolysiloxane according to claim 1, which is a reaction product of an organopolysiloxane represented by formula (5) with at least one selected from the group consisting of an organopolysiloxane represented by formula (6) and an alkoxysilane compound having one or more alkoxy groups.

3. The organopolysiloxane according to claim 1, which is an intermolecular reaction product of an organopolysiloxane represented by formula (5).

4. The organopolysiloxane according to any one of claims 1 to 3, which is represented by formula (1) or formula (2). In formulas (1) and (2), R １ are independently a saturated hydrocarbon group having 1 to 12 carbon atoms or hydrogen, X is independently acryloyl, alkyl, carboxyl, vinyl, methacryloyl, aryl, amino, isocyanate, isocyanuric, epoxy, hydroxyl, mercapto, or a monovalent group having any of the above atomic groups, a group represented by formula (3), or a group represented by formula (4), at least one X is a group represented by formula (3), m, l, and k are independently integers of 0 to 10, and j is an integer of 1 to 10; In formula (3) and formula (4), R ２ are independently a saturated hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms; Y is independently a divalent hydrocarbon group having 1 to 8 carbon atoms or oxygen; and h is independently an integer from 1 to 400.

5. The organopolysiloxane according to any one of claims 1 to 4, having a number average molecular weight (Mn) of 500 to 300,000.

6. A method for producing the organopolysiloxane of claim 2, which comprises reacting the organopolysiloxane of formula (5) of claim 1 with at least one selected from the organopolysiloxane of formula (6) of claim 1 and an alkoxysilane compound having one or more alkoxy groups.

7. A method for producing the organopolysiloxane according to claim 3, which comprises reacting the organopolysiloxane represented by formula (5) according to claim 1 intermolecularly.

8. The method for producing organopolysiloxane according to claim 6 or 7, wherein an organometallic catalyst is used as the catalyst in the reaction.

9. A method for using the organopolysiloxane according to any one of claims 1 to 5 to disperse a filler in a liquid medium.

10. An organopolysiloxane composition comprising the organopolysiloxane (A) according to any one of claims 1 to 5, and a filler (B).

11. The organopolysiloxane composition according to claim 10, further comprising a liquid medium (C).

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