JP5265885B2 - Low hardness heat conductive resin composition and sheet-like heat radiation member using the same - Google Patents

Description

  The present invention relates to a low-hardness heat conductive resin composition and a sheet-like heat radiating member using the same. More specifically, the present invention relates to a low-hardness heat conductive resin composition suitably used for a sheet-shaped heat radiation member having excellent heat dissipation, tackiness, and flexibility as a heat conductive material, and the resin composition. It is related with the sheet-like heat radiating member which has the above-mentioned property formed and hardened.

Heat transfer materials with high heat transfer efficiency, adhesives, sealing materials, etc. for cooling or radiating heat sources are required in various fields including the automobile field, the home appliance field, the electric / electronic field, and the communication field. In particular, in the semiconductor field, removal of heat generated by integration and higher frequency is an issue. Therefore, a heat radiating sheet is generally used for heat radiation of heating elements such as ICs and CPUs used in electric devices and electronic parts such as plasma displays, transistors, capacitors, personal computers, and the like. In addition to high thermal conductivity, flexibility and panel retention are required.
On the other hand, plastics and rubbers that are lightweight and have good insulating properties have been widely used in the electronic materials field, but these have the problem that heat is difficult to pass compared to metals, etc., and improvements that incorporate inorganic fillers etc. Has been done. However, if the amount of filler added is increased in order to increase thermal conductivity, problems such as being hard and fragile will occur.
In order to solve such problems, heat dissipation materials using silicone have been widely used so far. However, it has been pointed out that the low molecular weight silicone contained in the silicone evaporates and adheres to the contact, resulting in a contact failure. On the other hand, although a urethane heat dissipation material is also disclosed, polyether polyol and polyester polyol are inferior in electrical insulation. Polybutadiene-based polyols have many double bonds and thus have low heat resistance. In addition, silicone and polyether polyol-based or polyester polyol-based polyurethane have drawbacks such as low moisture resistance, and the long-term stability may become a problem, for example, the heat-dissipating filler absorbs water and performance deteriorates. is there.
A hydrogenated product of polybutadiene polyol, which has improved the disadvantages of polybutadiene-based polyurethane, is disclosed, but the cured product is hard, and when a large amount of filler is added, it is difficult to form a film, and it has good adhesion to a heating element, heat sink, etc. Unfortunately, there are problems such as gaps and reduced thermal conductivity.

For example, a urethane-based heat dissipating material composition containing a hydrogenated product of a polyhydroxybutadiene polymer as a main component is disclosed (for example, see Patent Document 1). However, this composition has a problem that the Shore A hardness (25 ° C.) at the time of blending a filler of about 80% by mass shows a high value of around 90.
Also, (1) a highly heat conductive laminate obtained by laminating a sheet woven with metal fibers and impregnating or applying a thermosetting resin having a heat deformation temperature in the range of -130 ° C to 130 ° C. Body (for example, refer to Patent Document 2), (2) made of an elastomer material that can be flexibly deformed and can be in close contact with a heating element, and the elastomer material is in a gel-like base material mainly composed of a urethane resin and a plasticizer Further, a heat dissipating polyurethane containing a heat dissipating material in which fine particles of a ceramic material are dispersed as a heat conducting filler (see, for example, Patent Document 3), (3) a polyol, and an inorganic filler having a particle diameter of 0.157 mm or less. A polyol composition for a resin composition, wherein the inorganic filler is contained in an amount of 100 parts by weight or more and 300 parts by weight or less based on 100 parts by weight of the polyol. A heat-dissipating sheet containing a fat composition (see, for example, Patent Document 4), (4) A heat-dissipating sheet in which aluminum hydroxide is dispersed and contained as a particulate filler in a polyurethane composed of castor oil-modified polyol and isocyanate. A heat dissipating sheet having a thermal conductivity of 0.5 to 1.0 W / m · K by the parallel plate method and a flame retardance level by UL94 of better than V-2 (for example, see Patent Document 5) is disclosed. Yes.
However, the above (1) to (4) are all technologies for the polyurethane heat dissipation material, but do not use a hydrogenated product of polyisoprene polyol as a main agent.
On the other hand, a technique of adding process oil has been disclosed as an attempt to lower the hardness of the heat dissipation composition and improve the thermal conductivity (see, for example, Patent Document 6). However, this technique uses a non-crosslinked styrene-based thermoplastic elastomer as a matrix, and is not obtained by curing a hydrogenated product of a polyisoprene-based polyol as a main component.

JP 58-122912 A Japanese Patent Laid-Open No. 5-16275 JP-A-11-111899 JP 2000-226426 A JP 2004-342758 A JP 2006-193626 A

  Under such circumstances, the present invention is a non-silicone-based heat conductive compound that is excellent in flexibility despite containing a large amount of filler, and various uses for which heat conductivity is required, Particularly, a low-hardness heat conductive resin composition suitably used for a sheet-shaped heat radiation member excellent in heat dissipation, tackiness, and flexibility, and a sheet-shaped heat radiation member having the above properties formed by molding and curing the resin composition. It is intended to provide.

As a result of intensive studies to achieve the above object, the inventors of the present invention have developed a thermally conductive filler into a polyol compound comprising a predetermined proportion of a hydrogenated hydroxyl-containing polyisoprene and a hydrogenated hydroxyl-containing polybutadiene. At least one selected from metal hydroxides, metal oxides and metal nitrides, and preferably a polyisocyanate compound as a curing agent, each in a predetermined ratio, and if necessary, a plasticizer, particularly a hydrocarbon It has been found that the object can be achieved by a resin composition obtained by blending a plasticizer at a predetermined ratio. The present invention has been completed based on such findings.
That is, the present invention
[1] (A) (a-1) Hydrogenated product of polyisoprene having a hydroxyl group of 10 to 100% by mass
And (a-2) a polyol compound consisting of 90 to 0% by mass of a hydrogenated hydroxyl-containing polybutadiene, and (B) at least one selected from metal hydroxides, metal oxides and metal nitrides A thermal conductive filler and (C) a curing agent are included, and the content of the component (B) is 100 to 5000 parts by mass with respect to 100 parts by mass of the component (A), and the content of the component (C) Is a quantity having a molar ratio of the reactive group as the curing agent in the component (C) / the hydroxyl group in the component (A) of 0.5 to 2.5. Composition,
[2] The low-hardness heat conductive resin composition according to [1], further including a plasticizer as the component (D) at a ratio of 1000 parts by mass or less with respect to 100 parts by mass of the component (A).
[3] The hydrogenated product of the hydroxyl group-containing polyisoprene as the component (a-1) has a number average molecular weight of 200 to 20000 and has a 1,4-bond of 50 mol% or more in the microstructure. ] Or the low hardness thermal conductive resin composition according to [2],
[4] The hydrogenated hydroxyl-containing polybutadiene component (a-2) has a number average molecular weight of 200 to 20000, and the molar ratio of 1,2-bond to 1,4-bond is in the microstructure. The low-hardness heat conductive resin composition according to any one of [1] to [3], which is 50:50 to 95: 5,
[5] The low-hardness heat conductive resin composition according to any one of [1] to [4], wherein the curing agent of the component (C) is a polyisocyanate compound,
[6] The low-hardness heat conductive resin composition according to any one of [2] to [5] above, wherein the plasticizer of the component (D) is a hydrocarbon plasticizer, and
[7] A sheet-like heat radiating member formed by molding and curing the low-hardness heat conductive resin composition according to any one of [1] to [6],
Is to provide.

  According to the present invention, it is a non-silicone-based heat conductive compound that is excellent in flexibility despite containing a large amount of filler, and various uses that require heat conductivity, in particular, heat dissipation, tackiness, It is possible to provide a low-hardness heat conductive resin composition suitably used for a sheet-like heat radiation member having excellent flexibility, and a sheet-like heat radiation member having the above properties formed by molding and curing the resin composition.

First, the low hardness heat conductive resin composition of the present invention will be described.
The low-hardness heat conductive resin composition of the present invention (hereinafter sometimes simply referred to as a resin composition) is (A) (a-1) 10 to 100% by mass of a hydrogenated hydroxyl group-containing polyisoprene, (a-2) a polyol compound composed of 90 to 0% by mass of a hydrogenated hydroxyl group-containing polybutadiene, and (B) at least one heat conduction selected from metal hydroxide, metal oxide, and metal nitride It is a resin composition containing a conductive filler, (C) a curing agent, and optionally (D) a plasticizer.
[Polyol compound]
In the resin composition of the present invention, the polyol compound used as the component (A) includes (a-1) 10 to 100% by mass of a hydrogenated polyisoprene hydrogenated product and (a-2) hydrogenated hydroxylated polybutadiene. It is a polyol compound comprising 90 to 0% by mass of a product, and is a component that forms a flexible matrix by reacting with a curing agent that is a component (C) described later.

<Hydrogenated product of hydroxyl-containing polyisoprene>
In the present invention, by using a hydrogenated product of (a-1) hydroxyl group-containing polyisoprene as the polyol compound, the intended low-hardness heat conductive composition can be obtained.
The number average molecular weight Mn of the hydrogenated product of the hydroxyl group-containing polyisoprene is preferably in the range of 200 to 20000. If this number average molecular weight Mn is 200 or more, the cured product will not be too hard and will have an appropriate rubber elasticity, and if it is 20000 or less, it will have an appropriate viscosity and can be uniformly blended. . A more preferred number average molecular weight Mn is in the range of 500 to 10,000, and particularly preferably in the range of 1,000 to 5,000. The number average molecular weight Mn is a value in terms of polystyrene measured by a gel permeation chromatography method (GPC method). In the hydrogenated product of the hydroxyl group-containing polyisoprene, the number of hydroxyl groups in one molecule is an average. It is preferable that it exists in the range of 1.7-4.0 pieces. If the number of hydroxyl groups is 1.7 or more, curing is sufficiently performed and stickiness of the cured product is suppressed, while if it is 4.0 or less, the cured product has an appropriate crosslinking density, Gelation of the compound and the compound is suppressed, and a product with good quality is obtained. The number of hydroxyl groups is more preferably 1.8 to 3.0 on average, and 1.9 to 2.5 is particularly preferable. In the hydrogenated hydroxyl-containing polyisoprene, the position of the hydroxyl group may be either at the molecular chain end or inside the molecular chain, but the one at the molecular chain end is preferred.
Furthermore, in the hydrogenated product of the hydroxyl group-containing polyisoprene, in its microstructure, 1,4-bond is usually 50 mol% or more, preferably 70 mol% or more from the viewpoint of rubber elasticity.
In addition, other copolymerizable monomer units such as styrene, ethylene, propylene, and a diene compound can be included as long as the characteristics are not impaired.

<Hydrogenated product of hydroxyl-containing polybutadiene>
In the present invention, in order to obtain a highly heat conductive resin composition with a large amount of the component (B) heat conductive filler, together with the hydrogenated hydroxyl-containing polyisoprene component (a-1) ( As the component a-2), a hydrogenated product of a hydroxyl group-containing polybutadiene can be used in combination.
The number average molecular weight Mn in the hydroxylated polybutadiene hydrogenated product and the number and position of hydroxyl groups in one molecule are the same as in the case of the hydroxylated polyisoprene hydrogenated product described above.
In the hydrogenated hydroxyl-containing polybutadiene, the molar ratio of 1,2-bonds to 1,4-bonds is preferably 50:50 to 95: 5 in the microstructure. When the molar ratio is within the above range, it is liquid at normal temperature and is easy to handle, and the cured product has moderate flexibility, stickiness is suppressed, and mechanical strength is improved. A more preferable molar ratio of 1,2-bond and 1,4-bond is 50:50 to 85:15, and 50:50 to 75:25 is particularly preferable.
Furthermore, in the hydrogenated product of the hydroxyl group-containing polybutadiene, other copolymerizable monomer units such as styrene, ethylene, propylene, and a diene compound can be included as long as the characteristics are not impaired.

In the resin composition of the present invention, when the hydrogenated product of the hydroxyl group-containing polybutadiene as the component (a-2) is used in combination with the hydrogenated product of the hydroxyl group-containing polyisoprene as the component (a-1), From the viewpoint of the blending effect of the component (a-2), the component (a-1) is 10 to 80% by mass, and the component (a-2) is It is preferable that it is 90-20 mass%, It is more preferable that (a-1) component is 25-75 mass%, and (a-2) component is 75-25 mass%.
In the resin composition of the present invention, it is a raw material for the hydrogenated hydroxyl-containing polyisoprene used as the component (a-1) and, if necessary, the hydrogenated hydroxyl-containing polybutadiene used as the component (a-2). The production method of the hydroxyl group-containing polyisoprene and the hydroxyl group-containing polybutadiene is not particularly limited, and can be easily produced by a conventionally known method such as radical polymerization or anion polymerization.
For example, when radically polymerizing a diene monomer, isoprene or butadiene, hydrogen peroxide, an azo compound having a hydroxyl group (for example, 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide, etc.]) Alternatively, a hydroxyl group-containing liquid polyisoprene or polybutadiene can be obtained by radical polymerization using a hydroxyl group-containing peroxide (such as cyclohexanone peroxide) as a polymerization initiator, and the amount of the polymerization initiator used is, for example, H _{2 with} respect to 100 g of the diene monomer. When O ₂ is used, 1.0 to 50 g, when 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide] is used, 5.0 to 100 g and cyclohexanone peroxide are added. When used, 5.0 to 100 g is appropriate. Although it is possible to carry out without solvent, it is preferable to use a solvent for ease of control of the reaction, etc. Ethanol, isopropanol, n-butanol, etc. are usually used as the solvent, and the reaction temperature is 80 to 150. The reaction temperature is suitably from 0.5 to 15 hours.

In the case of anion polymerization of isoprene or butadiene, a dilithium compound such as naphthalenedilithium is used as a catalyst, a diene monomer is anionically polymerized to produce a living polymer, and a hydroxyl group-containing liquid is also reacted by reacting with a monoepoxy compound or the like. Polyisoprene or polybutadiene can be obtained. Although the polymerization can be carried out without a solvent, it is preferable to use a solvent from the same viewpoint as in the case of radical polymerization. As the solvent, saturated hydrocarbons such as hexane and cyclohexane are preferably used. The reaction temperature is suitably 50 to 100 ° C., and the reaction time is suitably 1 to 10 hours. As the monoepoxy compound, for example, ethylene oxide or propylene oxide can be used.
A method of producing a living polymer by anionic polymerization using such a dilithium compound as a catalyst and reacting a monoepoxy compound or the like usually gives a polyol compound having hydroxyl groups at both ends of the molecular chain, and has a microstructure. This is the preferred method because it can be controlled.
In any of the radical polymerization method and the anionic polymerization method, another copolymerizable monomer such as styrene, ethylene, propylene, and a diene compound can be appropriately copolymerized as desired.
The hydroxyl group-containing polyisoprene and the hydroxyl group-containing polybutadiene thus obtained are hydrogenated by a conventionally known method to obtain a desired hydroxyl group-containing polyisoprene hydrogenated product and a hydroxyl group-containing polybutadiene hydrogenated product. Can do.
The hydrogenation treatment is performed, for example, in an organic solvent in the presence of a hydrogenation catalyst under hydrogen pressure. As the hydrogenation catalyst, for example, palladium-carbon, reduced nickel, rhodium-based heterogeneous catalyst, Ziegler-based homogeneous catalyst, or the like can be used.
When a heterogeneous catalyst is used, a hydrogenation reaction is performed in a suitable organic solvent at a reaction temperature of about room temperature to about 200 ° C. under a hydrogen pressure of about 10 to 10 MPa. The reaction time is about 1 to 48 hours.
On the other hand, when a homogeneous catalyst is used, a hydrogenation reaction is performed in a suitable solvent at a reaction temperature of about room temperature to about 150 ° C. under a hydrogen pressure of about normal pressure to about 5 MPa. The reaction time is about 1 to 24 hours.

[Thermal conductive filler]
In the resin composition of the present invention, at least one particle selected from metal hydroxide particles, metal oxide particles, and metal nitride particles is used as the thermally conductive filler of component (B).
Here, examples of the metal hydroxide particles include particles such as aluminum hydroxide and magnesium hydroxide, and examples of the metal oxide particles include particles such as aluminum oxide, titanium oxide, magnesium oxide, and silicon oxide. Examples of the physical particles include particles such as boron nitride, silicon nitride, and aluminum nitride. In addition, as the thermally conductive filler of the component (B), a substance that easily conducts heat, such as metal particles such as copper, aluminum, and iron, or metal carbide particles such as silicon carbide, can be used.
These may be used alone or in combination of two or more. Among them, alumina particles, aluminum nitride particles, aluminum hydroxide particles, and boron nitride particles have good dispersibility and heat conduction. It is preferable because the properties can be increased. Particularly in applications where electrical insulation is required, metal oxide particles and metal nitride particles are preferred as substances having high electrical insulation and high thermal conductivity, and alumina particles, aluminum nitride particles, and boron nitride particles are preferred. These heat conductive fillers may be powdery, granular, spherical or needle-shaped, and the particle size and particle size distribution can be appropriately selected according to applications such as high filling properties and thin film moldability. Moreover, the surface treatment may be performed for the purpose of improving the wettability of the matrix and the filler.
In the resin composition of this invention, the heat conductive filler of the said (B) component is mix | blended in the ratio of 100-5000 mass parts with respect to 100 mass parts of said (A) component. If this blending amount is 100 parts by mass or more, good thermal conductivity is obtained, and if it is 5000 parts by mass or less, moderate flexibility can be ensured and a homogeneous molded body can be produced. . The preferable compounding quantity of the said (B) component is 200-4000 mass parts, and 800-2500 mass parts is especially preferable.

[Curing agent]
In the resin composition of the present invention, as the component (C), a curing agent that reacts with the hydroxyl group of the polyol compound of the component (A) to crosslink and cure the component (A) is used.
As this hardening | curing agent, the polyisocyanate compound is suitable from a viewpoint of the physical property of the hardened | cured material obtained. This polyisocyanate compound is an organic compound having two or more isocyanate groups in one molecule, and the type thereof is not particularly limited.
Examples of the polyisocyanate compound include known aromatic, aliphatic, and alicyclic compounds. Specifically, 4,4′-diphenylmethane diisocyanate, 2,2′-diphenylmethane diisocyanate, a mixture of 4,4′- and 2,2′-diphenylmethane diisocyanate (all MDI), tolylene diisocyanate (TDI), carbodiimide Modified diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate, phenylene diisocyanate, naphthalene-1,5-diisocyanate, o-toluidine diisocyanate, triphenylmethane triisocyanate, tris (isocyanatephenyl) thiophosphate, isopropylbenzene-2,4-diisocyanate, etc. Aromatic polyisocyanates; aliphatics such as xylylene diisocyanate (XDI) and tetramethylxylylene diisocyanate (TMXDI) Aromatic polyisocyanates (polyisocyanates in which isocyanate groups are bonded to aromatic rings via aliphatic hydrocarbon groups, ie polyisocyanates having no isocyanate groups bonded directly to aromatic rings in the molecule); hexamethylene Diisocyanate, dodecane diisocyanate, lysine diisocyanate, lysine ester triisocyanate, 1,6,11-undecane triisocyanate, 1,8-diisocyanate-4-isocyanate methyloctane, 1,3,6-hexamethylene triisocyanate, trimethylhexamethylene diisocyanate Aliphatic polyisocyanates such as transcyclohexane-1,4-diisocyanate, bicycloheptane triisocyanate, isophorone diisocyanate (IPDI), dicyclo Cyclohexyl diisocyanate (hydrogenated MDI), hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, can be mentioned alicyclic polyisocyanates such as hydrogenated tetramethylxylylene diisocyanate.

In addition, cyclized trimers (isocyanurate-modified products), burette-modified products of the above polyisocyanate compounds, ethylene glycol, 1,4-butanediol, propylene glycol, dipropylene glycol, trimethylolpropane, polyether polyol Polyol compounds such as polymer polyol, polytetramethylene ether glycol, polyester polyol, acrylic polyol, polyalkadiene polyol, polyalkadiene polyol hydrogenated product, partially saponified ethylene-vinyl acetate copolymer, castor oil-based polyol, and the like An addition reaction product with a polyisocyanate compound is used.
These polyisocyanate compounds can also be used as a mixture of two or more, and the isocyanate groups of these polyisocyanate compounds can be used as phenols, oximes, imides, mercaptans, alcohols, ε-caprolactam, ethyleneimine, A so-called blocked isocyanate compound blocked with a blocking agent such as α-pyrrolidone, diethyl malonate, sodium bisulfite, boric acid or the like can also be used.
In the resin composition of the present invention, the content of the curing agent which is the component (C) is the content of the component (C) in terms of the degree of crosslinking (curing degree), the balance between the physical properties of the cured product and the economic efficiency. The molar ratio of the reactive group as the curing agent / the hydroxyl group in the component (A) is 0.5 to 2.5, preferably 0.7 to 1.5, more preferably 0.9 to 1.2. Amount. Examples of the reactive group as the curing agent in the component (C) include an isocyanate group (NCO group) when the curing agent is a polyisocyanate compound.
As will be described later, when using a chain extender such as a single chain diol or diamine as an optional component, or a polyol other than the component (A), the amount of hydroxyl group or amino group in these compounds is taken into account. Thus, it is important to determine the amount of the curing agent for component (C).

[Plasticizer]
In the resin composition of this invention, in order to improve a softness | flexibility, a plasticizer can be contained as (D) component as needed. There are no particular restrictions on the type of plasticizer, and ordinary plasticizers can be used. However, hydrocarbon-based plasticizers are preferred as compounds having excellent heat resistance and low bleed, such as α-olefin oligomers and hydrogenation thereof. Products, paraffinic oils and the like can be preferably used.
These may be used individually by 1 type and may be used in combination of 2 or more type. Examples of the paraffinic oil include liquid paraffin, paraffinic process oil, or a mixed oil thereof.
In this invention, when using the plasticizer of this (D) component, the compounding quantity is 1000 mass parts with respect to 100 mass parts of said (A) component from viewpoints of the property of hardened | cured material, suppression of bleeding, etc. The following are preferable, 100 to 500 parts by mass are more preferable, and 150 to 350 parts by mass are further preferable.

[Optional ingredients]
In the resin composition of the present invention, physical properties are improved within the range in which the object of the present invention is not impaired (processability improvement due to viscosity reduction, mechanical strength, heat resistance, weather resistance, chemical resistance, etc.), cost reduction, For other purposes, if necessary, as optional components, polyols other than component (A), short-chain diols and diamines as chain extenders, inorganic fillers and organic fillers other than thermally conductive fillers, antioxidants Agents, ultraviolet absorbers, light stabilizers, antistatic agents, flame retardants, colorants such as pigments and dyes, and the like.
Although there is no restriction | limiting in particular in the kind of polyol other than the said (A) component, A thing with favorable compatibility with the polyol compound of (A) component is preferable. Examples of the short-chain diol as the chain extender include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, and the diamine includes, for example, trimethylenediamine, Examples include tetramethylene diamine and hexamethylene diamine.
Examples of inorganic fillers other than thermally conductive fillers include zinc, aluminum, copper, nickel, glass spheres, glass flakes, glass fibers, carbon black (channel black, furnace black, acetylene black, thermal black), carbon fibers, and graphite. , Asbestos, kaolin clay, wax stone clay, talc, scumite, cryolite, wollastonite, diatomaceous earth, slate powder, whiting, feldspar powder, mica, gypsum, quartz powder, fine silica, attapulgite, sericite, volcanic ash , Meteorite, calcium carbonate, magnesium carbonate, barium sulfate, calcium silicate, zeolite, potassium titanate, boron nitrite, molybdenum disulfide and the like.
On the other hand, organic fillers include, for example, natural fibers such as rubber powder, cellulose, lignin, chitin, leather powder, coconut shell, wood powder, cotton, hemp, wool, silk, nylon, polyester, vinylon, acetate, acrylic And synthetic resin powder such as polyethylene, polypropylene, polystyrene, ABS resin, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polymethyl methacrylate, polyvinyl chloride, epoxy resin, phenol resin, and the like.

In preparation of the low-hardness heat conductive resin composition (liquid diene polymer composition) of the present invention, the (A) polyol compound, (B) heat conductive filler, (C) curing agent, and optionally used. (D) A plasticizer and various optional components are mixed at about 0 to 120 ° C., preferably 15 to 100 ° C. using a mixing device, a kneading device, etc., and about 0.5 second to 8 hours, preferably 1 second to A liquid diene polymer composition is prepared by stirring and mixing for about 5 hours. Under the present circumstances, when using a polyisocyanate compound as (C) hardening | curing agent, the one-shot method or the prepolymer method shown below is normally employ | adopted for preparation of a composition.
<One-shot method>
First, at least the components other than the polyisocyanate compound are blended and mixed at the above temperature and time to obtain a mixture. A polyisocyanate compound and optional components not used in the previous mixing are added to this mixture and mixed at the above temperature and time to obtain a liquid diene polymer composition. A preferred molar ratio NCO / (OH + NH ₂ ) at this time is 0.5 to 2.5.
<Prepolymer method>
Addition of at least one of a hydroxyl group-containing compound, a diamine compound and a polyisocyanate compound within a predetermined molar ratio NCO / OH, NCO / NH ₂ or NCO / (OH + NH ₂ ) of about 1.7 to 25 The prepolymer is obtained by reacting in the presence or absence of part or all of the agent. The reaction temperature is the same as above, and the time is usually 0.1 to 10 hours, preferably 0.5 to 8 hours. The remaining components are mixed with the prepolymer at the above temperature and time to obtain a liquid diene polymer composition. A preferable molar ratio NCO / (OH + NH ₂ ) at this time is 0.5 to 2.5.
Moreover, the method of producing prepolymer and making it react with the humidity (water) in air as follows can also be employ | adopted.
In the molar ratio NCO / (OH + NH ₂ ) in the range of about 1.7 to 5.0, all the components are blended and reacted to obtain a prepolymer. The reaction temperature is the same as above, and the time is usually 0.1 to 10 hours, preferably 0.5 to 8 hours. This prepolymer is reacted with moisture (water) in the air.

The low-hardness heat conductive resin composition (liquid diene polymer composition) prepared in this manner is used for various applications, and can be cured in various forms by being cured. .
The low-hardness heat conductive resin composition of the present invention includes, for example, a heat radiation film / sheet for cooling various electronic / electric equipment, a heat conductive insulating material / potting material / seal material / vibration-proof material, a heat conductive adhesive, It can be used as conductive grease, heat conductive paint, heat conductive tape, anti-condensation / fog prevention / freezing prevention, snow removal, heating and other various heat conductive materials. In particular, it is suitably used for the production of a sheet-like heat radiating member having excellent heat dissipation, tackiness and flexibility.

Next, the sheet-like heat radiation member of the present invention will be described.
The sheet-like heat radiating member of the present invention is obtained by molding and curing the low-hardness heat conductive resin composition of the present invention obtained as described above by a conventionally known method.
The sheet-like heat radiating member of the present invention can be prepared in various hardnesses depending on the application, but preferably has a Shore E hardness of 10 to 80, and particularly preferably in the range of 20 to 50. When the hardness is high, the mechanical strength is increased, but the adhesion to the heating element is deteriorated and the heat transfer is deteriorated. On the other hand, if the hardness is too low, it is difficult to keep the shape stable for a long time because of its softness. Furthermore, the higher the thermal conductivity, the better, but various adjustments can be made with the amount of the heat-dissipating filler added depending on the application from the balance with hardness and other physical properties. A range of 0.5 to 10 W / m · K, particularly 0.8 to 5.0 W / m · K is preferable as the sheet-like heat radiation member.
Although the thickness of the sheet-like heat radiating member of this invention changes with uses, it is about 10 micrometers-about 20 mm normally, Preferably it is 50 micrometers-5 mm.
The sheet-like heat radiating member of the present invention is excellent in heat dissipation, tackiness, and flexibility, and particularly generates heat used in electrical equipment and electronic parts such as plasma displays, transistors, capacitors, and personal computers (notebook PCs, desktop PCs). It is effective for heat dissipation of the body. In addition, the present invention can be applied to products using a heat dissipation material, parts / parts using a heat dissipation material, and the like. Products that use heat dissipation materials include televisions (liquid crystal TVs, plasma TVs, organic EL TVs, rear projection TVs, CRT TVs), personal computer peripherals (liquid crystal monitors, inkjet printers, laser printers, hard disk drives, optical disk drives), video・ Audio equipment (digital still camera, digital video camera, digital recorder, portable DVD player), communication (mobile phone, home facsimile), home appliances (air conditioner, electric refrigerator, washing machine, clothes dryer, vacuum cleaner, microwave oven) , Rice cookers, dishwashers, dehumidifiers, air purifiers), hobbies (home video game machines, portable game machines) and in-vehicle (car navigation systems, car stereos), etc., used for organic EL TV Is preferred.
Parts, parts, etc. that use heat dissipation materials include various packages such as IC, CPU, LSI, modules, system boards, lead frames, wiring boards, light sources, planar light sources, LEDs, organic EL, inorganic EL, backlights, Ceramic packages, display panels, displays, power systems, AC adapters, transformers, secondary batteries, switching power supplies, motors, heat sinks, heat sinks, heat pipes, heat dissipation systems, fan motors, various automotive control computer ECUs (engine control, Power window control, power steering control, brake control, airbag control, etc.) and optical communication devices, and the like, and preferably used for a planar light source body.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
In addition, the physical property of the heat conductive hardened | cured material obtained in each case was measured in accordance with the method shown below.
(1) Shore E hardness Measured according to JIS K6253.
(2) Thermal conductivity A test piece of 70 mm × 50 mm × 1 mm was prepared, and a hot disk was used with a sensor (HTK-14 type) with a thermal conductivity meter [manufactured by Kyoto Electronics Industry Co., Ltd., TPA-501]. Measured by the method.

Production Example 1 (Manufacture of hydrocarbon compounds)
(1) Dimerization of 1-decene using metallocene complex In a three-necked flask with an internal volume of 5 liters substituted with nitrogen, 3.0 kg of 1-decene, bis (cyclopentadienyl) zirconium dichloride (zirconocene) which is a metallocene complex 0.9 g (3 mmol) (also called dichloride) and methylaluminoxane (manufactured by Albemarle, 8 mmol in terms of Al) were sequentially added, and the mixture was stirred at room temperature (20 ° C. or lower). The reaction solution changed from yellow to reddish brown. After 48 hours from the start of the reaction, methanol was added to stop the reaction, and then an aqueous hydrochloric acid solution was added to the reaction solution to wash the organic layer. Next, the organic layer was vacuum distilled to obtain 2.5 kg of a fraction (decene dimer) having a boiling point of 120 to 125 ° C./26.6 Pa (0.2 Torr). When this fraction was analyzed by gas chromatography, the concentration of decene dimer was 99% by mass, and the vinylidene olefin ratio in the decene dimer was 97% by mass.
(2) Vinylidene olefin dimerization and hydrogenation step To a nitrogen-substituted 5 L three-necked flask, add 2.5 kg of the dimer obtained in the previous section and 4.3 ml of a 13% by weight toluene solution of diethylaluminum chloride, It was immersed in an oil bath at 50 ° C. with stirring, and 10 ml of 35% by mass hydrogen chloride water was added. After 1 hour, dilute hydrochloric acid was added to stop the reaction, and the unreacted raw material was removed by distillation under reduced pressure from the solution obtained by decomposing and removing the catalyst component. Next, the dimerization reaction product was transferred to an autoclave with an internal volume of 5 L, 5 g palladium / alumina 5 g was added thereto, and then purged with nitrogen. Further, after hydrogen substitution, the temperature was raised to a hydrogen pressure of 0.8 MPa. The hydrogenation reaction was carried out for 8 hours. After confirming that no more hydrogen absorption occurred, the temperature was lowered and the pressure was released, and the hydrogenated product was taken out of the autoclave. The catalyst was separated from the hydrogenated product by filtration to obtain 2.2 kg of a colorless transparent oily product. When the oil was analyzed by gas chromatography, the proportion of saturated hydrogen having 40 carbon atoms was 92.6% by mass.

Reference example 1
Hydrogenated polyisoprene polyol [made by Idemitsu Kosan Co., Ltd., trade name “EPOL”, 1,4-bond 80 mol%, number average molecular weight 2500, average hydroxyl group content 0.90 mol / kg, average number of hydroxyl groups in one molecule 2.3 pieces] 100 parts by mass of aluminum nitride powder [made by Tokuyama Co., Ltd., average particle size 1.1 μm] 250 parts by mass, and hydrogenated MDI [manufactured by Sumitomo Bayer Urethane Co., Ltd., trade name as a polyisocyanate compound] “Dismodule W”] was added so that the NCO / OH molar ratio was 1.05, and the mixture was stirred and mixed. Thereafter, 0.01 parts by mass of dibutyltin dilaurate [manufactured by Kyodo Yakuhin Co., Ltd.] was added as a reaction catalyst, and after curing under conditions of 10 MPa, 120 ° C. and 1 hour in a 1 mm thick mold, at 70 ° C. Cured for 15 hours. The resulting thermally conductive cured product had a Shore E hardness of 76 and a thermal conductivity of 1.35 W / m · K.
Reference example 2
A heat conductive cured product was prepared in the same manner as in Reference Example 1 except that the amount of aluminum nitride powder was changed to 160 parts by mass in Reference Example 1 . The resulting thermally conductive cured product had a Shore E hardness of 59 and a thermal conductivity of 1.04 W / m · K.

Example 1
50 parts by mass of “EPOL” (supra), hydrogenated polybutadiene polyol [manufactured by Sartomer, Inc., trade name “KRASOL HLBH-P3000”, 1,4-bond 35 mol%, number average molecular weight 3100, average hydroxyl group content 0 .56 mol / kg, 1.9 average number of hydroxyl groups in one molecule], 50 parts by mass of polyalphaolefin [made by Idemitsu Kosan Co., Ltd., trade name “PAO5010”], alumina powder [Showa Titanium Co., Ltd. ), Trade name “Arnabeads CBA-20S”, average particle size 10 μm] 1250 parts by mass, hydrogenated MDI [manufactured by Sumitomo Bayer Urethane Co., Ltd., trade name “Dismodule W”] as a polyisocyanate compound, NCO / OH It added so that molar ratio might be set to 1.05, and it stirred and mixed. Thereafter, 0.01 parts by mass of dibutyltin dilaurate [manufactured by Kyodo Yakuhin Co., Ltd.] was added as a reaction catalyst, and after curing under conditions of 10 MPa, 120 ° C. and 1 hour in a 1 mm thick mold, at 70 ° C. Cured for 15 hours. The resulting thermally conductive cured product had a Shore E hardness of 30 and a thermal conductivity of 1.35 W / m · K.
Example 2
In Example 1 , 1250 parts by mass of the aluminum nitride used in Reference Example 1 was added instead of alumina, and 200 parts by mass of the hydrocarbon compound obtained in Production Example 1 was added instead of “PAO5010”. Produced a thermally conductive cured product in the same manner as in Example 1 . The resulting thermally conductive cured product had a Shore E hardness of 26 and a thermal conductivity of 1.88 W / m · K.
Example 3
The same formulation as in Example 2 was coated on a release paper using a bar coater in a sheet form with a thickness of 200 μm, cured in an oven at 120 ° C. for 1 hour, and then 70 ° C. A heat radiating sheet was prepared by curing for 15 hours. This heat radiating sheet had good tackiness.

  The low-hardness heat conductive resin composition of the present invention is suitably used as a heat conductive material for various uses, particularly a sheet-like heat radiating member excellent in heat dissipation, tackiness and flexibility. The sheet-like heat radiating member of the present invention is excellent in heat dissipation, tackiness, and flexibility, and particularly generates heat used in electrical equipment and electronic parts such as plasma displays, transistors, capacitors, and personal computers (notebook PCs, desktop PCs). It is effective for heat dissipation of the body. In addition, the present invention can be applied to products using a heat dissipation material, parts / parts using a heat dissipation material, and the like.

Claims (7)

(A) a polyol compound comprising (a-1) a hydrogenated product of hydroxyl group-containing polyisoprene 10 to 80 % by mass and (a-2) a hydrogenated product of hydroxyl group-containing polybutadiene 90 to 20 % by mass, and (B) At least one heat conductive filler selected from metal hydroxide, metal oxide and metal nitride, and (C) a curing agent, and (C) the curing agent of the component is a polyisocyanate compound, The content of the component (B) is 100 to 5000 parts by mass with respect to 100 parts by mass of the component (A), and the content of the component (C) is reactive as a curing agent in the component (C). A low-hardness heat conductive resin composition characterized in that the molar ratio of the hydroxyl group in the group / (A) component is 0.5 to 2.5.   (B) Content of a component is 800-2500 mass parts with respect to 100 mass parts of (A) component, The low-hardness heat conductive resin composition of Claim 1 characterized by the above-mentioned.   Furthermore, the low-hardness heat conductive resin composition of Claim 1 or 2 which contains a plasticizer as a (D) component in the ratio of 1000 mass parts or less with respect to 100 mass parts of (A) component.   The hydrogenated hydroxyl-containing polyisoprene as the component (a-1) has a number average molecular weight of 200 to 20000 and has a 1,4-bond of 50 mol% or more in the microstructure. The low-hardness heat conductive resin composition according to any one of the above.   The hydrogenated hydroxyl-containing polybutadiene component (a-2) has a number average molecular weight of 200 to 20000, and in the microstructure, the molar ratio of 1,2-bonds to 1,4-bonds is 50:50. It is -95: 5. The low-hardness heat conductive resin composition in any one of Claims 1-4. (D) The plasticizer of a component is a hydrocarbon plasticizer, The low-hardness heat conductive resin composition in any one of Claims 3-5 . Low hardness thermally conductive resin composition molded, sheet-like heat radiating member obtained by curing according to any one of claims 1-6.