Thermally conductive composition and cured product

Abstract

To provide a thermally conductive composition that can yield a cured product with excellent thermal conductivity, and to provide a cured product of the thermally conductive composition.SOLUTION: A thermally conductive composition contains a polyisocyanate component and a polyol component, and a thermally conductive filler. The polyisocyanate component includes a derivative of a polyisocyanate monomer with up to 5 carbon atoms.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a thermally conductive composition and a cured product thereof. [Background technology]

[0002] Electronic devices, including semiconductors and batteries, generate heat during operation, and the resulting temperature rise can lead to malfunctions and destruction. Heat-dissipating materials are used to suppress this temperature rise. Heat-dissipating materials efficiently transfer heat from a heat source to a cooling medium or heat sink. Known examples of heat-dissipating materials include highly thermally conductive polyurethane resin compositions and their cured products.

[0003] Known examples of highly thermally conductive polyurethane resin compositions include polyurethane resins and inorganic fillers. For example, a reaction product of a polybutadiene polyol having an average hydroxyl value of 103 mgKOH / g and an isocyanurate-modified hexamethylene diisocyanate has been proposed as the polyurethane resin. For example, aluminum hydroxide has been proposed as the inorganic filler. Furthermore, it has been proposed to further add a plasticizer to polyurethane resin compositions containing these (see, for example, Patent Document 1 (Example 1)). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2016-098328 Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, the polyurethane resin composition and the cured product thereof may not have sufficient thermal conductivity.

[0006] The present invention relates to a thermally conductive composition that can give a cured product having excellent thermal conductivity, and to a cured product of the thermally conductive composition. [Means for solving the problem]

[0007] The present invention [1] is a thermally conductive composition comprising a polyisocyanate component, a polyol component, and a thermally conductive filler, wherein the polyisocyanate component comprises a thermally conductive composition containing a derivative of a polyisocyanate monomer having 5 or less carbon atoms.

[0008] The present invention [2] includes the thermally conductive composition according to the above [1], wherein the average number of isocyanate groups in the derivative is 2.7 or more.

[0009] The present invention [3] includes the thermally conductive composition according to the above [1] or [2], in which the polyisocyanate monomer is pentamethylene diisocyanate.

[0010] The present invention [4] includes the thermally conductive composition according to any one of the above [1] to [3], wherein the derivative is an isocyanurate derivative.

[0011] The present invention [5] includes the thermally conductive composition according to any one of the above [1] to [4], wherein the isocyanate group content of the derivative is 21.0 mass % or more.

[0012] The present invention [6] includes the thermally conductive composition according to any one of the above [1] to [5], wherein the polyol component includes polycaprolactone polyol and / or castor oil polyol.

[0013] The present invention [7] includes the thermally conductive composition according to any one of the above [1] to [6], wherein the thermally conductive filler includes aluminum hydroxide and / or aluminum nitride.

[0014] The present invention [8] comprises the thermally conductive composition according to any one of the above [1] to [7], in which the thermally conductive filler is contained in an amount of 200 parts by mass or more per 100 parts by mass of the total amount of the polyisocyanate component and the polyol component.

[0015] The present invention [9] includes a cured product of the thermally conductive composition according to any one of the above [1] to [8]. [Effects of the Invention]

[0016] The thermally conductive composition of the present invention is a thermally conductive composition containing a polyisocyanate component, a polyol component, and a thermally conductive filler. In the thermally conductive composition, the reaction product of the polyisocyanate component and the polyol component forms a matrix resin in which the thermally conductive filler is dispersed.

[0017] In such a thermally conductive composition, the polyisocyanate component contains a derivative of a polyisocyanate monomer having 5 or less carbon atoms. In such a case, the matrix resin has a relatively high crosslink density. Therefore, the distance between the thermally conductive fillers in the matrix resin becomes relatively short. As a result, the above-mentioned thermally conductive composition can produce a cured product with excellent thermal conductivity.

[0018] Furthermore, the reaction product of the polyisocyanate component and the polyol component is a polyurethane resin. The polyurethane resin can form hydrogen bonds with the thermally conductive filler. Therefore, the thermally conductive composition can further shorten the distance between the thermally conductive fillers in the matrix resin. As a result, the thermally conductive composition can produce a cured product with excellent thermal conductivity.

[0019] The cured product of the present invention has excellent thermal conductivity because it is a cured product of the above-mentioned thermally conductive composition. DETAILED DESCRIPTION OF THE INVENTION

[0020] The thermally conductive composition of the present invention contains a polyisocyanate component, a polyol component, and a thermally conductive filler.

[0021] (Polyisocyanate component) The polyisocyanate component includes derivatives of polyisocyanate monomers having 5 or fewer carbon atoms.

[0022] Examples of polyisocyanate monomers having 5 or less carbon atoms include aliphatic polyisocyanate monomers having 5 or less carbon atoms. More specifically, examples include linear aliphatic polyisocyanate monomers having 5 or less carbon atoms and alicyclic polyisocyanate monomers having 5 or less carbon atoms. Preferred examples of polyisocyanate monomers having 5 or less carbon atoms include linear aliphatic polyisocyanate monomers having 5 or less carbon atoms.

[0023] Examples of linear aliphatic polyisocyanate monomers having 5 or less carbon atoms include methane diisocyanate, 1,2-ethane diisocyanate, 1,3-propane diisocyanate, 1,2-propane diisocyanate, 1,4-butane diisocyanate, 1,3-butane diisocyanate, 1,2-butane diisocyanate, 1,5-pentane diisocyanate (pentamethylene diisocyanate, PDI), 1,4-pentane diisocyanate, 1,3-pentane diisocyanate, and 1,2-pentane diisocyanate. These may be used alone or in combination of two or more. From the viewpoints of thermal conductivity, bleed resistance, and mechanical properties of the cured product, 1,5-pentane diisocyanate (pentamethylene diisocyanate) is preferred.

[0024] The derivative preferably has a relatively high average number of isocyanate groups, the details of which will be described later.

[0025] Derivatives having a relatively high average number of isocyanate groups include, for example, isocyanurate derivatives and polyol adducts. These can be used alone or in combination of two or more types.

[0026] As the derivative, from the viewpoint of the thermal conductivity, bleeding resistance and mechanical properties of the cured product (described later), preferably, an isocyanurate derivative is used.

[0027] The isocyanurate derivative is an isocyanurate reaction product of a polyisocyanate monomer. The isocyanurate derivative can be obtained by a known method. For example, a polyisocyanate monomer is subjected to an isocyanurate reaction in the presence of a known isocyanurate catalyst. The reaction conditions are appropriately set depending on the purpose and application.

[0028] Furthermore, if necessary, the polyisocyanate monomer may be modified with a known alcohol before the isocyanuration reaction. Furthermore, the isocyanurate derivative may contain an allophanate derivative. In this case, the isocyanurate derivative is an isocyanurate derivative composition containing an allophanate derivative and an isocyanurate derivative.

[0029] If necessary, unreacted polyisocyanate monomer may be separated from the reaction product liquid after the isocyanuration reaction. Examples of the separation method include distillation and extraction, and preferably distillation. Examples of the distillation method include thin film distillation. The distillation conditions are appropriately set depending on the purpose and application.

[0030] Specifically, the isocyanurate derivative is produced, for example, by the following method: In this method, the polyisocyanate monomer is reacted with an alcohol.

[0031] Examples of alcohols include low-molecular-weight alcohols. Low-molecular-weight alcohols are organic compounds that have one or more hydroxyl groups in one molecule and have a relatively low molecular weight. Note that a relatively low molecular weight refers to a molecular weight of less than 200 (the same applies hereinafter).

[0032] Examples of low molecular weight alcohols include aliphatic low molecular weight alcohols and aromatic low molecular weight alcohols, and preferably aliphatic low molecular weight alcohols. Examples of aliphatic low molecular weight alcohols include aliphatic low molecular weight alcohols having 1 to 12 carbon atoms. Examples of aliphatic low molecular weight alcohols include aliphatic low molecular weight monools (monohydric alcohols) and aliphatic low molecular weight polyols (dihydric or higher alcohols).

[0033] The aliphatic low-molecular-weight monool is an aliphatic organic compound having one hydroxyl group per molecule and a relatively low molecular weight. Examples of the aliphatic low-molecular-weight monool include aliphatic low-molecular-weight monohydric alcohols having 1 to 12 carbon atoms. Examples of the aliphatic low-molecular-weight monohydric alcohols having 1 to 12 carbon atoms include alkyl alcohols having 1 to 12 carbon atoms. Examples of the alkyl alcohols having 1 to 12 carbon atoms include methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, s-butanol, t-butanol, 2-ethylhexyl alcohol, and lauryl alcohol. These can be used alone or in combination of two or more.

[0034] The aliphatic low-molecular-weight polyol is an aliphatic organic compound having two or more hydroxyl groups in one molecule and a relatively low molecular weight. Examples of the aliphatic low-molecular-weight polyol include aliphatic low-molecular-weight polyols having 1 to 12 carbon atoms. Examples of the aliphatic low-molecular-weight polyol include aliphatic low-molecular-weight dihydric alcohols.

[0035] More specifically, examples of aliphatic low-molecular-weight polyols include aliphatic low-molecular-weight dihydric alcohols having 1 to 12 carbon atoms. Examples of aliphatic low-molecular-weight dihydric alcohols having 1 to 12 carbon atoms include alkylenediols having 1 to 12 carbon atoms. Examples of alkylenediols having 1 to 12 carbon atoms include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and neopentyl glycol. These can be used alone or in combination of two or more types.

[0036] The alcohols can be used alone or in combination of two or more. The molecular weight of the low-molecular-weight alcohol (when used in combination, this may be the average molecular weight (the same applies hereinafter)) is, for example, less than 200, preferably less than 150. The molecular weight of the low-molecular-weight alcohol is, for example, 40 or more, preferably 50 or more.

[0037] The average number of hydroxyl groups in the alcohols is, for example, 1 or more. The average number of hydroxyl groups in the alcohols is, for example, 3 or less, preferably 2 or less.

[0038] More specifically, examples of alcohols include preferably aliphatic low-molecular-weight alcohols having 1 to 12 carbon atoms, more preferably aliphatic low-molecular-weight monohydric alcohols having 1 to 12 carbon atoms and aliphatic low-molecular-weight dihydric alcohols having 1 to 12 carbon atoms, even more preferably alkyl alcohols having 1 to 12 carbon atoms and alkylenediols having 1 to 12 carbon atoms, even more preferably alkyl alcohols having 1 to 12 carbon atoms, even more preferably alkyl alcohols having 1 to 4 carbon atoms, and particularly preferably isobutanol.

[0039] Alcohols can be used alone or in combination of two or more types.

[0040] The blending ratio of the polyisocyanate monomer and the alcohols is appropriately set. More specifically, the equivalent ratio (NCO / OH) of the isocyanate groups of the polyisocyanate monomer to the hydroxyl groups of the alcohols exceeds, for example, 5, preferably 10 or more, more preferably 50 or more, even more preferably 100 or more, and particularly preferably 300 or more. Furthermore, the equivalent ratio (NCO / OH) of the isocyanate groups of the polyisocyanate monomer to the hydroxyl groups of the alcohols is, for example, 2000 or less, preferably 1000 or less, more preferably 800 or less, and even more preferably 600 or less.

[0041] The amount of the alcohol is, for example, 0.01 part by mass or more, preferably 0.05 part by mass or more, more preferably 0.1 part by mass or more, relative to 100 parts by mass of the polyisocyanate monomer, and for example, 10 parts by mass or less, preferably 5 parts by mass or less, more preferably 3 parts by mass or less, even more preferably 2 parts by mass or less, and particularly preferably 1 part by mass or less, relative to 100 parts by mass of the polyisocyanate monomer.

[0042] The reaction conditions for the polyisocyanate monomer and the alcohol are appropriately set within a range that does not impair the excellent effects of the present invention. More specifically, the environmental conditions are an inert atmosphere and normal pressure. The reaction temperature is, for example, 20°C or higher, preferably 40°C or higher. The reaction temperature is, for example, 100°C or lower, preferably 90°C or lower. The reaction time is, for example, 0.05 hours or higher, preferably 0.2 hours or higher. The reaction time is, for example, 10 hours or shorter, preferably 6 hours or shorter.

[0043] In this method, a urethanization catalyst can be added to the polyisocyanate monomer and alcohols as needed. Examples of the urethanization catalyst include known amines and known organometallic compounds. The amount of the urethanization catalyst added is not particularly limited and can be appropriately determined depending on the purpose and application.

[0044] This causes a urethane reaction between the polyisocyanate monomer and the alcohol, resulting in a urethane reaction product.

[0045] Next, in this method, the urethanized reaction product is subjected to an isocyanurate reaction.

[0046] More specifically, in this method, an isocyanuration catalyst (trimerization catalyst) is blended with the urethanization reaction product, and the mixture is heated.

[0047] The isocyanuration catalyst is not particularly limited as long as it is a catalyst that can promote the isocyanuration of isocyanate groups. Examples of isocyanuration catalysts include tertiary amines, Mannich bases, Friedel-Crafts catalysts, metal salts of alkylcarboxylic acids, organometallic compounds, halogen-substituted organophosphorus compounds, tetraalkylammonium hydroxides, weak organic acid salts of tetraalkylammonium, trialkylhydroxyalkylammonium hydroxides, and weak organic acid salts of trialkylhydroxyalkylammonium. These can be used alone or in combination of two or more types.

[0048] The isocyanuration catalyst preferably includes an organic weak acid salt of trialkylhydroxyalkylammonium.

[0049] Examples of trialkylhydroxyalkylammonium include N-(2-hydroxypropyl)-N,N,N-trimethylammonium, trimethylhydroxyethylammonium, triethylhydroxypropylammonium, and triethylhydroxyethylammonium. These can be used alone or in combination of two or more.

[0050] Examples of organic weak acid salts include acetate, propionate, 2-ethylhexanoate, octylate, caprate, myristate, and benzoate. These can be used alone or in combination of two or more.

[0051] The mixing ratio of the isocyanurate catalyst relative to 100 parts by mass of the polyisocyanate monomer is, for example, 0.01 part by mass or more, preferably 0.03 part by mass or more, and for example, 0.3 part by mass or less, preferably 0.1 part by mass or less, more preferably 0.08 part by mass or less.

[0052] The reaction conditions for the isocyanurate reaction are appropriately set within a range that does not impair the excellent effects of the present invention. More specifically, the environmental conditions are an inert atmosphere and normal pressure. The reaction temperature is, for example, 25°C or higher, preferably 50°C or higher. The reaction temperature is, for example, 150°C or lower, preferably 100°C or lower. The reaction time is, for example, 30 minutes or longer, preferably 45 minutes or longer. The reaction time is, for example, 10 hours or shorter, preferably 5 hours or shorter.

[0053] Then, when the reaction rate (isocyanate group conversion rate) of the reaction solution reaches a predetermined value, a reaction terminator is added to the reaction solution. The conversion rate of the isocyanate group when the reaction is terminated is, for example, 5% by mass or more, preferably 10% by mass or more. The conversion rate of the isocyanate group when the reaction is terminated is, for example, 30% by mass or less, preferably 20% by mass or less, and more preferably 18% by mass or less. The conversion rate of the isocyanate group can be calculated by a known method.

[0054] Examples of reaction terminators include phosphoric acid, monochloroacetic acid, benzoyl chloride, dodecylbenzenesulfonic acid, o-toluenesulfonic acid, p-toluenesulfonic acid, methyl o-toluenesulfonate, methyl p-toluenesulfonate, o-toluenesulfonamide, and p-toluenesulfonamide. These can be used alone or in combination of two or more. The blending ratio of the reaction terminator is appropriately set depending on the purpose and application.

[0055] Alternatively, a catalyst adsorbent may be added instead of the reaction terminator. Examples of catalyst adsorbents include chelating resins and ion exchange resins. These may be used alone or in combination of two or more. The blending ratio of the catalyst adsorbent is appropriately determined depending on the purpose and application.

[0056] This stops the isocyanuration reaction.

[0057] In each of the above reactions, a known reaction solvent can be added. The mixing ratio of the reaction solvent is appropriately set depending on the purpose and application. In each of the above reactions, the reaction solution can be purified. Examples of purification methods include distillation and extraction. By purification, unreacted polyisocyanate monomer is removed from the reaction solution. In addition, the urethanization catalyst, isocyanuration catalyst, catalyst deactivator, and / or reaction solvent are removed together with the polyisocyanate monomer.

[0058] In the above reaction, the polyisocyanate monomer is modified with isocyanurate, resulting in an isocyanurate derivative of the polyisocyanate monomer as the reaction product.

[0059] The derivatives of polyisocyanate monomers having 5 or less carbon atoms are used alone or in combination of two or more. As the derivatives of polyisocyanate monomers having 5 or less carbon atoms, from the viewpoints of thermal conductivity, bleed resistance, and mechanical properties of the cured product (described later), preferably, an isocyanurate derivative is used alone.

[0060] The isocyanurate derivative may contain an allophanate derivative as a by-product. In other words, the isocyanurate derivative may contain an isocyanurate group and may further contain an allophanate group. The content of the allophanate group is, for example, less than 30 mass%, preferably less than 20 mass%, and more preferably less than 10 mass% relative to the total amount of the isocyanurate group and the allophanate group (the same applies hereinafter).

[0061] The isocyanate group content of the derivative (a derivative of a polyisocyanate monomer having 5 or less carbon atoms) is, from the viewpoints of thermal conductivity, bleed resistance, and mechanical properties, for example, 15.0% by mass or more, preferably 20.0% by mass or more, and more preferably 21.0% by mass or more. From the viewpoints of thermal conductivity, bleed resistance, and mechanical properties, the isocyanate group content of the derivative is, from the viewpoints of thermal conductivity, bleed resistance, and mechanical properties, for example, 50.0% by mass or less, preferably 40.0% by mass or less, more preferably 30.0% by mass or less, even more preferably 25.0% by mass or less, and particularly preferably 23.0% by mass or less. The isocyanate group content is measured in accordance with the examples described later.

[0062] The average number of isocyanate groups in the derivative (a derivative of a polyisocyanate monomer having 5 or less carbon atoms) is, for example, 2.4 or more, preferably 2.5 or more, more preferably 2.6 or more, even more preferably 2.7 or more, still more preferably 2.8 or more, more preferably 2.9 or more, and particularly preferably 3.0 or more. The average number of isocyanate groups in the derivative is, for example, 6.0 or less, preferably 5.0 or less, more preferably 4.0 or less, and still more preferably 3.5 or less.

[0063] If the average number of isocyanate groups in the derivative exceeds the lower limit, the crosslink density of the matrix resin described below can be relatively high. Therefore, the distance between the thermally conductive fillers described below in the matrix resin described below can be relatively short. As a result, a cured product (described below) with excellent thermal conductivity can be obtained.

[0064] The average number of isocyanate groups is calculated based on the number average molecular weight and the isocyanate group equivalent weight using the following formula: Average number of isocyanate groups = number average molecular weight / isocyanate group equivalent

[0065] In the above formula, the number average molecular weight is the number average molecular weight of the derivative (a derivative of a polyisocyanate monomer having 5 or less carbon atoms). The number average molecular weight of the derivative is, for example, 300 or more, preferably 400 or more. The number average molecular weight of the derivative is, for example, 1200 or less, preferably 800 or less. The number average molecular weight is measured in accordance with the examples described later.

[0066] In the above formula, the isocyanate group equivalent is the isocyanate group equivalent of the derivative (a derivative of a polyisocyanate monomer having 5 or less carbon atoms). The isocyanate group equivalent of the derivative is, for example, 100 or more, or preferably 140 or more. The isocyanate group equivalent of the derivative is, for example, 280 or less, or preferably 200 or less. The isocyanate group equivalent is measured in accordance with the examples described later.

[0067] If the polyisocyanate component contains the above-mentioned derivative (a derivative of a polyisocyanate monomer having 5 or less carbon atoms), the crosslink density of the matrix resin described below can be made relatively high. Therefore, the distance between the thermally conductive fillers described below in the matrix resin described below becomes relatively short. As a result, a cured product (described below) with excellent thermal conductivity can be obtained.

[0068] The polyisocyanate component may contain, in addition to the above-mentioned derivatives (derivatives of polyisocyanate monomers having 5 or less carbon atoms), for example, polyisocyanate monomers having 5 or less carbon atoms, as long as the excellent effects of the present invention are not impaired.

[0069] In the polyisocyanate component, the content of polyisocyanate monomers having 5 or less carbon atoms is, for example, 30% by mass or less, preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 1% by mass or less. In addition, in the polyisocyanate component, the content of polyisocyanate monomers having 5 or less carbon atoms is, for example, 0% by mass or more. Preferably, the polyisocyanate component does not contain polyisocyanate monomers having 5 or less carbon atoms, or contains a trace amount of such a polyisocyanate monomer as an unavoidable impurity.

[0070] Furthermore, the polyisocyanate component may contain, in addition to the above-mentioned derivatives (derivatives of polyisocyanate monomers having 5 or less carbon atoms), for example, polyisocyanate monomers having 6 or more carbon atoms and / or derivatives of polyisocyanate monomers having 6 or more carbon atoms, within the range that does not impair the excellent effects of the present invention.

[0071] Examples of polyisocyanate monomers having 6 or more carbon atoms include known polyisocyanate monomers having 6 or more carbon atoms that are widely used industrially. More specifically, for example, 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), methylenebis(cyclohexyl isocyanate) (H 12 Examples of suitable diisocyanates include bis(isocyanatomethyl)cyclohexane (H6XDI), norbornane diisocyanate (NBDI), diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), naphthalene diisocyanate (NDI), and xylylene diisocyanate (XDI). These can be used alone or in combination of two or more.

[0072] Derivatives of polyisocyanate monomers having 6 or more carbon atoms include derivatives derived from polyisocyanate monomers having 6 or more carbon atoms by known methods. More specifically, the derivatives include, for example, uretdione derivatives, isocyanurate derivatives, allophanate derivatives, polyol adducts, biuret derivatives, urea derivatives, oxadiazinetrione derivatives, and carbodiimide derivatives. These can be used alone or in combination of two or more. A preferred derivative is an isocyanurate derivative.

[0073] In the polyisocyanate component, the content of polyisocyanate monomers having 6 or more carbon atoms and polyisocyanate monomers having 6 or more carbon atoms is, for example, 50% by mass or less, preferably 30% by mass or less, more preferably 10% by mass or less, and even more preferably 1% by mass or less. In addition, in the polyisocyanate component, the content of polyisocyanate monomers having 6 or more carbon atoms and polyisocyanate monomers having 6 or more carbon atoms is, for example, 0% by mass or more. Particularly preferably, the polyisocyanate component does not contain polyisocyanate monomers having 6 or more carbon atoms and polyisocyanate monomers having 6 or more carbon atoms.

[0074] The polyisocyanate component preferably comprises a derivative of a polyisocyanate monomer having 5 or less carbon atoms, more preferably comprises a derivative of a chain aliphatic polyisocyanate monomer having 5 or less carbon atoms, even more preferably comprises a derivative of pentamethylene diisocyanate, and particularly preferably comprises an isocyanurate derivative of pentamethylene diisocyanate.

[0075] The average number of isocyanate groups in the polyisocyanate component is, for example, 2.4 or more, preferably 2.5 or more, more preferably 2.6 or more, even more preferably 2.7 or more, still more preferably 2.8 or more, more preferably 2.9 or more, and particularly preferably 3.0 or more. The average number of isocyanate groups in the polyisocyanate component is, for example, 6.0 or less, preferably 5.0 or less, more preferably 4.0 or less, and still more preferably 3.5 or less.

[0076] If the average number of isocyanate groups in the polyisocyanate component is greater than the lower limit, the crosslink density of the matrix resin (described later) can be relatively high. Therefore, the distance between the thermally conductive fillers (described later) in the matrix resin (described later) can be relatively short. As a result, a cured product (described later) with excellent thermal conductivity can be obtained.

[0077] The isocyanate group content of the polyisocyanate component (isocyanate group concentration, NCO%) is, from the viewpoints of thermal conductivity, bleed resistance, and mechanical properties, for example, 15.0% by mass or more, preferably 20.0% by mass or more, and more preferably 21.0% by mass or more. Also, from the viewpoints of thermal conductivity, bleed resistance, and mechanical properties, the isocyanate group content of the polyisocyanate component is, from the viewpoints of thermal conductivity, bleed resistance, and mechanical properties, for example, 50.0% by mass or less, preferably 40.0% by mass or less, more preferably 30.0% by mass or less, even more preferably 25.0% by mass or less, and particularly preferably 23.0% by mass or less.

[0078] The proportion of the polyisocyanate component is, relative to 100 parts by mass of the thermally conductive composition, 0.1 parts by mass or more, preferably 1 part by mass or more, more preferably 2 parts by mass or more, even more preferably 3 parts by mass or more, particularly preferably 4 parts by mass or more, and most preferably 5 parts by mass or more. The proportion of the polyisocyanate component is, relative to 100 parts by mass of the thermally conductive composition, for example, 30 parts by mass or less, preferably 20 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 8 parts by mass or less, and particularly preferably 7 parts by mass or less.

[0079] (Polyol component) The polyol component may, for example, be a macropolyol.

[0080] A macropolyol is a polyol having a number average molecular weight of 200 or more.

[0081] Examples of macropolyols include polyether polyols, polyester polyols, polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, and vinyl monomer-modified polyols. These can be used alone or in combination of two or more.

[0082] The macropolyols preferably include polyether polyols, polyester polyols and vegetable oil polyols.

[0083] Examples of polyether polyols include polyoxyalkylene polyols, such as polyoxyalkylene (C2-3) polyols and polytetramethylene ether polyols.

[0084] Examples of polyoxyalkylene (C2-3) polyols include polyoxyethylene polyols, polyoxypropylene polyols, polyoxytriethylene polyols, and polyoxyethylene-polyoxypropylene polyols (random or block copolymers).

[0085] Examples of polytetramethylene ether polyols include ring-opening polymers (crystalline polytetramethylene ether glycols) obtained by cationic polymerization of tetrahydrofuran. Examples of polytetramethylene ether polyols also include amorphous polytetramethylene ether glycols. Amorphous polytetramethylene ether glycols are copolymerized with tetrahydrofuran and alkyl-substituted tetrahydrofuran and / or dihydric alcohols. Crystalline refers to a property of being solid at 25°C. Amorphous refers to a property of being liquid at 25°C.

[0086] Examples of polyester polyols include condensation polyester polyols and ring-opening polyester polyols. Examples of condensation polyester polyols include condensates of low-molecular-weight polyols (described below) and known polybasic acids. Examples of ring-opening polyester polyols include polycaprolactone polyols. Examples of polycaprolactone polyols include polycaprolactone diols. These can be used alone or in combination of two or more.

[0087] As the polyester polyol, preferably, a ring-opening polyester polyol is used, more preferably, a polycaprolactone polyol, and even more preferably, a polycaprolactone diol is used.

[0088] Polycaprolactone polyols can be obtained by ring-opening polymerization of lactones, such as β-lactone, γ-lactone, σ-lactone, and ε-lactone, using a low-molecular-weight polyol (described later) as an initiator.

[0089] Such polyester polyols are also available as commercially available products, for example, Capa 2043 (trade name, polycaprolactone diol, average molecular weight of about 400, manufactured by Ingevity).

[0090] Examples of vegetable oil polyols include coconut oil polyol and castor oil polyol, and preferably castor oil polyol.

[0091] Examples of castor oil polyols include unmodified castor oil polyols and ester-modified castor oil polyols.

[0092] Examples of unmodified castor oil polyols include castor oil (a vegetable oil containing a hydroxyl group).

[0093] Examples of ester-modified castor oil polyols include ester reaction products of castor oil fatty acids (such as ricinoleic acid) and known polyether polyols.

[0094] As the macropolyol, polycaprolactone polyol and / or castor oil polyol are preferred from the viewpoint of carbon neutrality and thermal conductivity, and polycaprolactone polyol is more preferred from the viewpoint of thermal conductivity.

[0095] The number average molecular weight of the macropolyol is, for example, 200 or more, preferably 300 or more, and for example, 5000 or less, preferably 2000 or less, more preferably 1000 or less, and still more preferably 900 or less.

[0096] The hydroxyl equivalent of the macropolyol is, for example, 50 or more, preferably 100 or more, more preferably It is preferably 150 or more, and for example, 3000 or less, preferably 2000 or less, more preferably 1000 or less, and even more preferably 500 or less.

[0097] From the viewpoint of the crosslink density of the polyurethane resin, the average number of hydroxyl groups of the macropolyol is, for example, 1.8 or more, preferably 2.0 or more, more preferably 2.5 or more, and for example, 5.0 or less, preferably 4.0 or less, more preferably 3.5 or less, and even more preferably 3.0 or less.

[0098] The polyol component may include a low molecular weight polyol.

[0099] The low molecular weight polyol is a polyol having a number average molecular weight of less than 200.

[0100] Examples of low-molecular-weight polyols include dihydric alcohols, trihydric alcohols, and tetrahydric or higher alcohols. Examples of dihydric alcohols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, and dipropylene glycol. Examples of trihydric alcohols include glycerin and trimethylolpropane. Examples of tetrahydric or higher alcohols include pentaerythritol and diglycerin. These may be used alone or in combination.

[0101] The proportion of the low-molecular-weight polyol relative to 100 parts by mass of the macropolyol is, for example, 30 parts by mass or less, preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 0 part by mass. That is, the polyol component particularly preferably consists of the macropolyol.

[0102] The proportion of the polyol component relative to the total amount of the thermally conductive composition is, for example, 2 mass% or more, preferably 5 mass% or more, more preferably 7 mass% or more, and even more preferably 7.5 mass% or more. The proportion of the polyol component relative to the total amount of the thermally conductive composition is, for example, 40 mass% or less, preferably 20 mass% or less, more preferably 15 mass% or less, and even more preferably 12 mass% or less.

[0103] The proportion of the polyol component is set so that the equivalent ratio of the isocyanate groups of the isocyanate component to the hydroxyl groups of the polyol component is a predetermined ratio, i.e., the equivalent ratio (NCO / OH) of the isocyanate groups of the polyisocyanate component to the hydroxyl groups of the polyol component is, for example, 0.5 or more, preferably more than 0.7, more preferably 0.8 or more, and for example, 2.0 or less, preferably 1.5 or less, more preferably 1.2 or less.

[0104] (thermal conductive filler) Examples of the thermally conductive filler include inorganic particles, such as carbides, nitrides, oxides, hydroxides, metals, and carbon-based materials. The inorganic particles are not limited to the examples given and can be selected arbitrarily.

[0105] Examples of oxides include iron oxide, silicon oxide (silica), aluminum oxide (alumina), magnesium oxide (magnesia), titanium oxide, cerium oxide, and zirconium oxide. Examples of oxides also include transition metal oxides such as barium titanate, and oxides doped with metal ions, such as indium tin oxide and antimony tin oxide.

[0106] Hydroxides include, for example, aluminum hydroxide, calcium hydroxide, and magnesium hydroxide.

[0107] Nitrides include, for example, silicon nitride, boron nitride, aluminum nitride, gallium nitride, chromium nitride, tungsten nitride, magnesium nitride, molybdenum nitride, and lithium nitride.

[0108] These thermally conductive fillers can be used alone or in combination of two or more.

[0109] The thermally conductive filler is preferably a hydroxide and / or a nitride, more preferably aluminum hydroxide and / or aluminum nitride, and even more preferably aluminum nitride.

[0110] The shape of the thermally conductive filler is not particularly limited, and examples thereof include spherical, blocky, needle-like, amorphous, and plate-like (scale-like) shapes.

[0111] The size of the thermally conductive filler is not particularly limited, and for example, its maximum length (average particle diameter in the case of a spherical shape) is, for example, 1 μm or more, preferably 2 μm or more, more preferably 4 μm or more, even more preferably 6 μm or more, particularly preferably 8 μm or more, and most preferably 10 μm or more, and for example, 50 μm or less, preferably 40 μm or less, more preferably 30 μm or less, even more preferably 20 μm or less, and particularly preferably 15 μm or less.

[0112] The proportion of the thermally conductive filler in the thermally conductive composition is, for example, 40% by volume or more, preferably 50% by volume or more, more preferably 60% by volume or more, even more preferably 65% ​​by mass or more, and for example, 80% by volume or less, preferably 79% by volume or less, more preferably 78% by volume or less.

[0113] The proportion of the thermally conductive filler in the thermally conductive composition is, for example, 40% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, particularly preferably 83% by mass or more, and most preferably 85% by mass or more, and for example, 99% by mass or less, preferably 95% by mass or less, more preferably 92% by mass or less.

[0114] The proportion of the thermally conductive filler, relative to 100 parts by mass of the total amount of the polyisocyanate component and the polyol component, is, for example, 200 parts by mass or more, preferably 400 parts by mass or more, more preferably 450 parts by mass or more, even more preferably 500 parts by mass or more, and particularly preferably 550 parts by mass or more, and is, for example, 6000 parts by mass or less, preferably 3500 parts by mass or less, more preferably 2000 parts by mass or less, and even more preferably 1000 parts by mass or less.

[0115] The thermally conductive composition can be produced by the following method. Specifically, a polyisocyanate component, a polyol component, and a thermally conductive filler are prepared in the above-mentioned proportions. Then, the thermally conductive filler is blended in the above-mentioned proportions with either or both of the polyisocyanate component and the polyol component. Preferably, the thermally conductive filler is blended in a mass ratio equal to that of the polyisocyanate component (curing agent) and the polyol component (main component).

[0116] The thermally conductive composition may also contain additives, such as urethane catalysts and silane coupling agents.

[0117] Examples of the urethanization catalyst include known urethanization catalysts, such as amines and organometallic compounds.

[0118] Examples of amines include tertiary amines, quaternary ammonium salts, and imidazoles. Examples of tertiary amines include triethylamine, triethylenediamine, bis-(2-dimethylaminoethyl)ether, and N-methylmorpholine. Examples of quaternary ammonium salts include tetraethylhydroxylammonium. Examples of imidazoles include imidazole and 2-ethyl-4-methylimidazole. These amines can be used alone or in combination of two or more.

[0119] Organometallic compounds include, for example, organotin compounds, organolead compounds, organonickel compounds, organocobalt compounds, organocopper compounds, and organobismuth compounds. Organotin compounds include, for example, tin acetate, tin octoate, tin oleate, tin laurate, dibutyltin diacetate, dimethyltin dilaurate, dibutyltin dilaurate (DBTDL), dibutyltin dimercaptide, dibutyltin maleate, dibutyltin dineodecanoate, dioctyltin dimercaptide, dioctyltin dilaurate, and dibutyltin dichloride. Organolead compounds include, for example, lead octoate and lead naphthenate. Organonickel compounds include, for example, nickel naphthenate. Organocobalt compounds include, for example, cobalt naphthenate. Organocopper compounds include, for example, copper octenate. Organobismuth compounds include, for example, bismuth octoate and bismuth neodecanoate. These organometallic compounds can be used alone or in combination of two or more.

[0120] These organometallic compounds are also commercially available, and examples thereof include Neostan U-100 (organotin compound, manufactured by Nitto Kasei Co., Ltd.), Formate TK-1 (organotin compound, manufactured by Mitsui Chemicals, Inc.), Fomrez UL-28 (organotin compound, manufactured by Momentive Chemicals), and Stanoct (organotin compound, manufactured by Mitsubishi Chemical Corporation).

[0121] These catalysts (amines and organometallic compounds) can be used alone or in combination of two or more kinds, and are preferably organometallic compounds, more preferably organotin compounds, and even more preferably dibutyltin dilaurate.

[0122] The blending ratio of the catalyst (based on 100% active ingredient amount) is, for example, 0.001 part by mass or more, preferably 0.01 part by mass or more, more preferably 0.015 part by mass or more, even more preferably 0.02 part by mass or more, per 100 parts by mass of the total amount of the polyisocyanate component and the polyol component, and is, for example, 0.2 part by mass or less, preferably 0.1 part by mass or less, more preferably 0.075 part by mass or less, even more preferably 0.05 part by mass or less, particularly preferably 0.04 part by mass or less, and most preferably 0.035 part by mass or less.

[0123] The urethane catalyst is added to the polyisocyanate component and / or the polyol component.

[0124] Examples of the silane coupling agent include known silane coupling agents. Examples of the known silane coupling agent include aminosilanes and epoxysilanes. Examples of the epoxysilane include 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropylmethyldimethoxysilane.

[0125] Silane coupling agents are commercially available, and examples thereof include KBM-403 (product name, 3-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Silicones Co., Ltd.).

[0126] These silane coupling agents can be used alone or in combination of two or more. As the silane coupling agent, preferred is epoxy silane, and more preferred is 3-glycidoxypropyltrimethoxysilane.

[0127] The blending ratio of the silane coupling agent is, for example, 0.1 parts by mass or more, preferably 0.5 parts by mass or more, more preferably 1.0 parts by mass or more, and even more preferably 1.5 parts by mass or more, relative to 100 parts by mass of the total amount of the polyisocyanate component and the polyol component. The blending ratio of the silane coupling agent is, for example, 50 parts by mass or less, preferably 40 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less, relative to 100 parts by mass of the total amount of the polyisocyanate component and the polyol component.

[0128] The silane coupling agent is added to the polyisocyanate component and / or the polyol component.

[0129] The thermally conductive composition may further contain other additives. Examples of such additives include reaction solvents, catalysts, epoxy resins, coating property improvers, leveling agents, antifoaming agents, stabilizers (such as antioxidants and UV absorbers), thickeners, anti-settling agents, plasticizers, surfactants, pigments, fillers, organic or inorganic fine particles, and anti-fungal agents. The amount of additives to be added is determined appropriately depending on the purpose and application.

[0130] The present invention includes a cured product of the thermally conductive composition described above. The cured product can be obtained by curing the thermally conductive composition described above.

[0131] Specifically, the cured product can be obtained by molding the thermally conductive composition using a known molding method, followed by curing. Examples of molding methods include cast molding. The drying and curing conditions are known and are not particularly limited, and examples include drying and curing at room temperature (25°C) for one week.

[0132] The above method causes a urethane reaction between the polyisocyanate component and the polyol component. This results in a polyurethane resin as a reaction product of the polyisocyanate component and the polyol component. The thermally conductive filler is then dispersed in the polyurethane resin (matrix resin). That is, the above method results in a cured product comprising the polyurethane resin and the thermally conductive filler dispersed in the polyurethane.

[0133] The urethane group concentration of the polyurethane resin is, for example, 1.0 mmol / g or more, preferably 1.5 mmol / g or more, more preferably 2.0 mmol / g or more. The urethane group concentration of the polyurethane resin is, for example, 4.0 mmol / g or more, preferably 3.0 mmol / g or more. The urethane group concentration of the polyurethane resin is calculated from the formulation.

[0134] If the urethane group concentration of the polyurethane resin is within the above range, the distance between particles of the thermally conductive filler can be made relatively short in the polyurethane resin, thereby achieving excellent thermal conductivity.

[0135] In the cured product, the dispersion form of the thermally conductive filler is not particularly limited. For example, the particles of the thermally conductive filler may be arranged at intervals in the polyurethane resin. Alternatively, at least a portion of the particles of the thermally conductive filler may be in contact with each other, for example, arranged in a rosary shape. From the viewpoint of thermal conductivity, preferably, at least a portion of the particles of the thermally conductive filler are in contact with each other. If at least a portion of the particles of the thermally conductive filler are in contact with each other, particularly excellent thermal conductivity can be obtained.

[0136] The thermally conductive composition includes a polyisocyanate component, a polyol component, and a thermally conductive filler. In the thermally conductive composition, the reaction product of the polyisocyanate component and the polyol component forms a matrix resin in which the thermally conductive filler is dispersed.

[0137] In such a thermally conductive composition, the polyisocyanate component contains a derivative of a polyisocyanate monomer having 5 or less carbon atoms. In such a case, the matrix resin has a relatively high crosslink density. Therefore, the distance between the thermally conductive fillers in the matrix resin becomes relatively short. As a result, the above-mentioned thermally conductive composition can produce a cured product with excellent thermal conductivity.

[0138] Furthermore, the reaction product of the polyisocyanate component and the polyol component is a polyurethane resin. The polyurethane resin can form hydrogen bonds with the thermally conductive filler. Therefore, the thermally conductive composition can further shorten the distance between the thermally conductive fillers in the matrix resin. As a result, the thermally conductive composition can produce a cured product with excellent thermal conductivity.

[0139] Furthermore, the cured product has excellent thermal conductivity because it is a cured product of the thermally conductive composition. [Example]

[0140] The present invention will be described in more detail below with reference to examples, but is not limited thereto. Specific numerical values ​​of the blending ratios (content ratios), physical property values, parameters, etc. used in the following description can be replaced with the upper limit values ​​(numeric values ​​defined as "not more than" or "less than") or lower limit values ​​(numeric values ​​defined as "not less than" or "exceeding") of the corresponding blending ratios (content ratios), physical property values, parameters, etc. described in the above "Form for Carrying Out the Invention." Note that "parts" and "%" are based on mass unless otherwise specified.

[0141] <Measurement method> (1) Isocyanate group content The isocyanate group content was measured using a potentiometric titrator by the n-dibutylamine method in accordance with JIS K-1603 (2007).

[0142] (2) Average number of isocyanate groups The average number of isocyanate groups was calculated by the following formula. Average number of isocyanate groups = number average molecular weight / isocyanate group equivalent

[0143] The isocyanate group equivalent in the above formula is synonymous with the amine equivalent. The isocyanate group equivalent (amine equivalent) was measured according to Method A or Method B of JIS K 1603-1 (2007).

[0144] The number average molecular weight in the above formula was measured by the following method. Approximately 0.03 g of a sample was collected and methyl urethane-treated with methanol. After removing excess methanol, 10 mL of tetrahydrofuran was added to dissolve the sample. The resulting solution was then subjected to gel permeation chromatography (GPC) under the following conditions.

[0145] Analytical equipment: High-speed GPC equipment HLC-8320 (manufactured by Tosoh) Detector: Differential refractive index detector Eluent: tetrahydrofuran Separation column: The following (1) to (4) are connected in series (1) TSKgel guardcolum HXL-L 6.0 x 40 (Tosoh Corporation) (2) TSKgel G1000HXL 7.8 x 300 (Tosoh Corporation) (3) TSKgel G2000HXL 7.8 x 300 (Tosoh Corporation) (4) TSKgel G3000HXL 7.8 x 300 (Tosoh Corporation) Measurement temperature: 40℃ Flow rate: 1mL / min Sample injection volume: 100μL Analysis device: Eco SEC (manufactured by Tosoh Corporation) System correction Standard material name: Polystyrene Calibration curve creation method: A graph of retention time and molecular weight was created using TOSOH TSKstandard Polystyrene with different molecular weights.

[0146] Synthesis Example 1 (Polyisocyanate A) In a reactor equipped with a thermometer, a stirrer, a nitrogen inlet tube, and a cooling tube, the following components were mixed under a nitrogen atmosphere to obtain a mixture. 500 parts by mass of 1,5-pentamethylene diisocyanate (PDI, manufactured by Mitsui Chemicals, Inc., trade name: Stabio PDI) 0.25 parts by mass of 2,6-di(tert-butyl)-4-methylphenol (also known as dibutylhydroxytoluene, BHT, hindered phenol antioxidant) Tetraphenyl dipropylene glycol diphosphite (organic phosphite ester, cocatalyst) 0.25 parts by mass

[0147] Next, 0.8 parts by mass of isobutanol was added to the mixture. Nitrogen was introduced into the mixture for 1 hour. The mixture was then heated to 80°C and reacted for 3 hours. Thereafter, the reaction product liquid was cooled to 60°C.

[0148] Next, 0.2 parts by mass of trimethyl-N-2-hydroxypropylammonium 2-ethylhexanoate (isocyanurate catalyst) was added to the reaction mixture, and the mixture was further reacted for 1.5 hours.

[0149] Thereafter, o-toluenesulfonamide (a reaction terminator) was added to the reaction product liquid in an amount of 0.01 parts by mass relative to 100 parts by mass of PDI.

[0150] Thereafter, the reaction product liquid was purified using a thin-film distillation apparatus (temperature 150°C, vacuum degree 93.3 Pa) until the amount of residual monomer was 1.0 mass % or less, thereby obtaining Polyisocyanate A.

[0151] Polyisocyanate A contained an isocyanurate derivative of PDI. The isocyanate group content of Polyisocyanate A was 21.0 mass%. The average number of isocyanate groups in Polyisocyanate A was 3.1.

[0152] Synthesis Example 2 (Polyisocyanate B) The 500 parts by mass of PDI was changed to 500 parts by mass of 1,6-hexamethylene diisocyanate (HDI, manufactured by Mitsui Chemicals, Inc., product name: Takenate 700). In addition, the 0.8 parts by mass of isobutanol was changed to 4.5 parts by mass of isobutanol. Polyisocyanate B was obtained in the same manner as in Synthesis Example 1, except for the above.

[0153] Polyisocyanate B contained an isocyanurate derivative of HDI. The isocyanate group content of Polyisocyanate B was 22.4 mass%. The average number of isocyanate groups in Polyisocyanate B was 2.8.

[0154] Synthesis Example 3 (Polyisocyanate C) Polyisocyanate C was obtained in the same manner as in Synthesis Example 1, except that 0.8 parts by mass of isobutanol was changed to 6.5 parts by mass of isobutanol.

[0155] Polyisocyanate C contained an isocyanurate derivative of PDI. The isocyanate group content of Polyisocyanate C was 24.0 mass%. The average number of isocyanate groups in Polyisocyanate C was 2.8.

[0156] Examples 1 to 12 and Comparative Examples 1 to 3 A polyisocyanate component and a polyol component were prepared according to the formulations shown in Tables 1 and 2. A thermally conductive filler and a silane coupling agent were also prepared according to the formulations shown in Tables 1 and 2. A urethane catalyst was also prepared according to the formulations shown in Tables 1 and 2.

[0157] The thermally conductive filler and the silane coupling agent were divided as follows: That is, the thermally conductive filler and the silane coupling agent were divided according to the mass ratio of the polyisocyanate component and the mass ratio of the polyol component relative to the total amount of the polyisocyanate component and the polyol component.

[0158] Then, the polyisocyanate component, a thermally conductive filler in an amount corresponding to the mass ratio of the polyisocyanate component, and a silane coupling agent in an amount corresponding to the mass ratio of the polyisocyanate component were mixed together to obtain a first liquid.

[0159] Further, a polyol component, a thermally conductive filler in an amount corresponding to the mass ratio of the polyol component, and a silane coupling agent in an amount corresponding to the mass ratio of the polyol component were mixed together to obtain a second liquid.

[0160] The first liquid, the second liquid, and the urethane catalyst were mixed together to obtain a thermally conductive composition.

[0161] <Preparation of test specimen> The thermally conductive composition was poured into a mold having an inner diameter of 45 mm and left to harden at room temperature (25°C) for 7 days, thereby obtaining a cured product of the thermally conductive composition.

[0162] <Measurement of thermal conductivity (thermal conductivity)> The thermal conductivity of the cured product was measured by the following method. Specifically, the thermal conductivity (23°C) of the cured product was measured using a hot disc thermal property measuring instrument (model number TPA-501, manufactured by Kyoto Electronics Manufacturing Co., Ltd.) according to a method conforming to ISO / CD220074-2. The results are shown in Tables 1 and 2.

[0163] Comparative Example 4 The following components were mixed to obtain a thermally conductive composition containing an acrylic resin and a thermally conductive filler.

[0164] 6.9 parts by mass of trimethylolpropane ethoxy triacrylate (manufactured by Daicel Allnex Corporation, trade name EBECRYL 160S, number of functional groups: 3, average molecular weight: approximately 428) 8.1 parts by mass of polyethylene glycol diacrylate with a molecular weight of 400 (manufactured by Kyoeisha Chemical, product name Light Acrylate 9EG-A, PEG400 diacrylate, number of functional groups: 2) Thermally conductive filler (manufactured by Nippon Light Metal Co., Ltd., product name V-325F, aluminum oxide (alumina)) 85 parts by mass Silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., product name KBM-403, 3-glycidoxypropyltrimethoxysilane (epoxysilane)) 1.7 parts by mass 3.0 parts by mass of organic peroxide (manufactured by NOF Corporation, trade name Perbutyl O(2-ethylhexanoyl)(tert-butyl)peroxide)

[0165] <Preparation of test specimen> The thermally conductive composition was heated at 120° C. for 1 hour, thereby obtaining a cured product of the thermally conductive composition.

[0166] <Measurement of thermal conductivity (thermal conductivity)> The thermal conductivity (23°C) of the cured product was measured in the same manner as in Example 1. The thermal conductivity was 0.9 W / m·K.

[0167] The number of functional groups and molecular weight of the thermally conductive composition of Comparative Example 4 were close to those of the thermally conductive composition of Example 9. However, the thermal conductivity of Comparative Example 4 was significantly lower than that of Example 9. The following reasons are considered to be the cause of these results.

[0168] That is, the acrylic resin cannot form hydrogen bonds with the thermally conductive filler. Therefore, in the thermally conductive composition of Comparative Example 4, the distance between the thermally conductive filler particles is relatively large. On the other hand, the polyurethane resin can form hydrogen bonds with the thermally conductive filler. Therefore, in the thermally conductive composition of Example 9, the distance between the thermally conductive filler particles is relatively small. Therefore, it is presumed that the thermal conductivity of Example 9 was improved by hydrogen bonding.

[0169] [Table 1]

[0170] [Table 2]

[0171] Details of the abbreviations in the table are given below. Capa2043: Product name, polycaprolactone diol, average number of hydroxyl groups: 2, average molecular weight: approximately 400, manufactured by Ingevity Capa3041: Trade name, polycaprolactone triol, average number of hydroxyl groups: 3, average molecular weight: 425, manufactured by Ingevity Eterol 5100-1000: Product name, condensed polyester polyol, average number of hydroxyl groups 2, average molecular weight 1000, manufactured by Choko Chemical Industry Co., Ltd. PTMEG-650: Polyether polyol (polytetramethylene ether glycol), average number of hydroxyl groups: 2, average molecular weight: approximately 650, manufactured by PTG Korea Actocol D-400: Polyether polyol (polyoxypropylene glycol), average number of hydroxyl groups: 2, average molecular weight: approximately 400, manufactured by Mitsui Chemicals, Inc. Castor oil: Model number Diamond, average hydroxyl group number 2.5, manufactured by Ito Oil Mills V-325F: Product name, aluminum oxide (alumina), manufactured by Nippon Light Metal Co., Ltd. TFZ-A10P: Product name, aluminum nitride, average particle size 10 μm, manufactured by Toyo Aluminum Co., Ltd. BX053: Product name, aluminum hydroxide, average particle size 6 μm, manufactured by Nippon Light Metal Co., Ltd. KBM-403: Trade name, 3-glycidoxypropyltrimethoxysilane (epoxy silane), manufactured by Shin-Etsu Chemical Co., Ltd. Neostan U-100: Trade name, urethane catalyst, dibutyltin dilaurate (organometallic catalyst, DBTDL), manufactured by Nitto Kasei Co., Ltd.

Claims

1. a polyisocyanate component and a polyol component; Thermally conductive filler and A thermally conductive composition comprising: the polyisocyanate component includes a derivative of a polyisocyanate monomer having 5 or less carbon atoms, the average number of isocyanate groups of the derivative is 2.7 or more; With respect to 100 parts by mass of the total amount of the polyisocyanate component and the polyol component, A thermally conductive composition, wherein the thermally conductive filler is contained in an amount of 200 parts by mass or more.

2. The polyisocyanate monomer is pentamethylene diisocyanate. The thermally conductive composition of claim 1 .

3. The derivative is an isocyanurate derivative. The thermally conductive composition according to claim 1 or 2.

4. The isocyanate group content of the derivative is 21.0% by mass or more. The thermally conductive composition according to any one of claims 1 to 3.

5. the polyol component comprises polycaprolactone polyol and / or castor oil polyol; The thermally conductive composition according to any one of claims 1 to 4.

6. The thermally conductive filler comprises aluminum hydroxide and / or aluminum nitride. The thermally conductive composition according to any one of claims 1 to 5.

7. A cured product of the thermally conductive composition according to any one of claims 1 to 6.

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