Two-component curable polyurethane resin composition

Abstract

The present invention provides a two-component curable polyurethane resin composition that exhibits excellent thermal conductivity and adhesion while suppressing the viscosity increase of the first component containing a polyol. [Solution] The two-component curable polyurethane resin composition comprises a first component containing a polyol (A), a heat dissipation filler (C1), and a dispersant (D), and a second component containing a polyisocyanate (B), wherein the polyol (A) contains 55 to 100% by mass of a polyol (a1) with an average number of functional groups of 2.5 to 3.0 and a number average molecular weight (Mn) of 1200 or less, the dispersant (D) contains a phosphate ester group-containing surfactant, the polyisocyanate (B) contains an aromatic polyisocyanate (b1), and the second component may also contain a heat dissipation filler (C2), with the total content of the heat dissipation filler (C1) and heat dissipation filler (C2) being 75 to 90% by mass.

Description

Technical Field

[0001] The present invention relates to a two-component curable polyurethane resin composition and a heat dissipation material using the same.

Background Art

[0002] Polyurethane resin compositions are used, for example, as heat dissipation materials in electric or electronic devices. Patent Document 1 describes a thermally conductive urethane resin composition containing a castor oil-based polyol, a polyisocyanate compound, and a thermally conductive filler.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, a heat dissipation material is placed between a heat-generating component and a cooling component, and is used by adhering it to both the heat-generating and cooling components. In this case, if the adhesion between the heat-generating component and the cooling component to the heat dissipation material is low, the heat generated by the heat-generating component will not be transferred to the cooling component, reducing the cooling efficiency and potentially causing malfunctions or failures. Similarly, if the thermal conductivity of the heat dissipation material is low, the cooling efficiency will also decrease. Therefore, when using a polyurethane resin composition as a heat dissipation material, it is required that it has excellent adhesion to the heat-generating component and the cooling component, as well as that the cured polyurethane resin composition has high thermal conductivity, in order to efficiently transfer the heat generated by the heat-generating component to the cooling component. However, if a large amount of inorganic filler is added to the polyol-containing component of the polyurethane resin composition to improve thermal conductivity, the viscosity tends to increase, and the adhesion of the cured polyurethane resin composition tends to decrease. Thus, it is difficult to achieve both high thermal conductivity and adhesion of the cured polyurethane resin composition and low viscosity of the polyol-containing component.

[0005] In view of the above, the present invention aims to provide a two-component curable polyurethane resin composition that exhibits excellent thermal conductivity and adhesion while suppressing the viscosity increase of the first component containing a polyol. [Means for solving the problem]

[0006] The present invention includes embodiments shown below. [1] A first component comprising a polyol (A), a heat dissipation filler (C1), and a dispersant (D), A second component comprising polyisocyanate (B), The aforementioned polyol (A) contains 55 to 100% by mass of polyol (a1) having an average number of functional groups of 2.5 to 3.0 and a number-average molecular weight (Mn) of 1200 or less. The dispersant (D) comprises a phosphate ester group-containing surfactant (d1), The aforementioned polyisocyanate (B) includes aromatic polyisocyanate (b1), The second component may also include a heat dissipation filler (C2). A two-component curable polyurethane resin composition in which the total content of the heat dissipation filler (C1) and heat dissipation filler (C2) is 75 to 90% by mass. [2] The two-component curable polyurethane resin composition according to [1], wherein the aromatic polyisocyanate (b1) is at least one selected from the group consisting of diphenylmethane diisocyanate and polymethylene polyphenyl polyisocyanate. [3] The two-component curable polyurethane resin composition according to any one of [1] to [2], wherein the phosphate ester group-containing surfactant (d1) is a polyoxyalkylene alkyl ether phosphate ester. [4] The two-component curable polyurethane resin composition according to any one of [1] to [3], wherein the heat dissipation filler (C1) is surface-treated with a silane coupling agent. [5] A two-component curable polyurethane resin composition according to any one of [1] to [4], wherein the second component is a heat dissipation filler (C2). A heat dissipation material obtained by curing a two-component curable polyurethane resin composition as described in any of [6] [1] to [5]. [Effects of the Invention]

[0007] The present invention can provide a two-component curable polyurethane resin composition that exhibits excellent thermal conductivity and adhesion while suppressing the viscosity increase of the first component containing a polyol. [Modes for carrying out the invention]

[0008] The two-component curable polyurethane resin composition comprises a first component containing a polyol (A), a heat dissipation filler (C1), and a dispersant (D), and a second component containing a polyisocyanate (B). The polyol (A) contains 55 to 100% by mass of a polyol (a1) with an average number of functional groups of 2.5 to 3.0 and a number average molecular weight (Mn) of 1200 or less; the dispersant (D) contains a phosphate ester group-containing surfactant (d1); the polyisocyanate (B) contains an aromatic polyisocyanate (b1); and the second component may also contain a heat dissipation filler (C2), with the total content of heat dissipation fillers (C1) and (C2) being 75 to 90% by mass.

[0009] <Component 1> [Polyol (A)] The first component contains polyol (A). The content of polyol (A) may be, for example, 5 to 55% by mass, 5 to 50% by mass, 5 to 40% by mass, or 5 to 30% by mass in the first component.

[0010] [Polyol (a1)] Polyol (a1) is a polyol with an average number of functional groups of 2.5 to 3.0 and a number-average molecular weight (Mn) of 1200 or less. By including polyol (a1) as the first component, it is possible to improve thermal conductivity and adhesion while suppressing the increase in viscosity of the first component.

[0011] Examples of polyols (a1) include castor oil-based polyols, polyether polyols, polyester polyols, polycarbonate polyols, acrylic polyols, polyolefin polyols, aliphatic polyols, aromatic polyols, dimer acid polyols, polycaprolactone polyols, polyisoprene polyols, hydrogenated polyisoprene polyols, and hydrogenated polybutadiene polyols, all of which have an average number of functional groups of 2.5 to 3.0 and a number-average molecular weight (Mn) of 1200 or less. The castor oil-based polyols are polyols produced using castor oil, castor oil fatty acids, and hydrogenated castor oil or hydrogenated castor oil fatty acids obtained by hydrogenation of these. Examples include castor oil, transesterified products of castor oil and other natural oils and fats, reaction products of castor oil and polyhydric alcohols, esterification reaction products of castor oil fatty acids and polyhydric alcohols, and polyols obtained by addition polymerization of alkylene oxides to these. Polyol (a1) may be used individually or in combination of two or more types.

[0012] Polyol (a1) exhibits improved adhesion to polyethylene terephthalate (PET) and aluminum when its average number of functional groups is 2.5 to 3.0. From the viewpoint of further improving adhesion to PET and aluminum, the average number of functional groups of polyol (a1) is preferably 2.6 to 3.0.

[0013] The polyol (a1) exhibits improved adhesion to PET and aluminum when its number-average molecular weight (Mn) is 1200 or less. From the viewpoint of further improving adhesion to PET and aluminum, the number-average molecular weight (Mn) of polyol (a1) is more preferably 50 or more, and even more preferably 70 or more. Furthermore, from the viewpoint of further improving adhesion to PET and aluminum, the number-average molecular weight (Mn) of polyol (a1) is more preferably 700 or less, and even more preferably 500 or less.

[0014] In this specification, the number average molecular weight (Mn) is a value measured under the following conditions by the GPC method (gel permeation chromatography method) and calculated using a calibration curve with standard polystyrene.

[0015] Column: TSKgel G4000HXL, TSKgel G3000HXL, TSKgel G2000HXL, TSKgel G1000HXL, and TSKgel G1000HXL are connected in series in this order. Mobile phase: THF (tetrahydrofuran) Mobile phase flow rate: 1.0 mL / min Column temperature: 40 °C Sample injection volume: 50 μL Sample concentration: 0.2 mass%

[0016] The polyol (a1) is contained in the polyol (A) at 55 to 100 mass%. From the viewpoint of further excellent adhesiveness and further lower viscosity of the first component, the content of the polyol (a1) is preferably 60 to 100 mass% in the polyol (A), more preferably 65 to 100 mass%, and still more preferably 70 to 100 mass%.

[0017] [Polyol (a2)] The polyol (A) may further contain another polyol (a2). Examples of the polyol (a2) include a polyol having an average functionality of less than 2.� or exceeding 3.0, or a polyol having a number average molecular weight (Mn) exceeding 1200. Examples of such polyols include castor oil-based polyols, polyether polyols, polyester polyols, polycarbonate polyols, acrylic polyols, polyolefin polyols, aliphatic polyols, aromatic polyols, dimer acid polyols, polycaprolactone polyols, polyisoprene polyols, hydrogenated polyisoprene polyols, and hydrogenated polybutadiene polyols.

[0018] [Heat dissipation filler (C1)] The first component contains a heat dissipation filler (C1). By the first component containing the heat dissipation filler (C1), the thermal conductivity of the cured two-component curable polyurethane resin composition is improved.

[0019] Examples of the heat dissipation filler (C1) include metal hydroxides, metal oxides, metal nitrides, and the like.

[0020] Examples of the metal hydroxide include aluminum hydroxide and magnesium hydroxide. Examples of the metal oxide include aluminum oxide, magnesium oxide, silicon oxide, and zinc oxide. Examples of the metal nitride include aluminum nitride, silicon nitride, and boron nitride.

[0021] From the viewpoint of further improving the thermal conductivity, the heat dissipation filler (C1) is preferably a metal hydroxide and a metal oxide, and more preferably aluminum hydroxide and aluminum oxide.

[0022] The heat dissipation filler (C1) is preferably surface-treated with a silane coupling agent. By the heat dissipation filler (C1) being surface-treated with a silane coupling agent, an increase in the viscosity of the first component containing the polyol can be further suppressed.

[0023] The heat dissipation filler (C1) is preferably a metal hydroxide and a metal oxide surface-treated with a silane coupling agent, and more preferably aluminum hydroxide and aluminum oxide surface-treated with a silane coupling agent.

[0024] Examples of the method of surface treatment with a silane coupling agent include a dry treatment in which a solution containing the silane coupling agent is sprayed onto the heat dissipation filler and mixed in a powder state.

[0025] Examples of silane coupling agents used for surface treatment of heat dissipation fillers include phenylsilane coupling agents, alkylsilane coupling agents, aminosilane coupling agents, epoxysilane coupling agents, and vinylsilane coupling agents.

[0026] Phenylsilane coupling agents are silane coupling agents having a phenyl group, and examples include phenyltrialoxysilanes such as phenyltriethoxysilane and phenyltrimethoxysilane, and diphenyldialkoxysilanes such as diphenyldimethoxysilane.

[0027] Alkylsilane coupling agents are silane coupling agents having an alkyl group directly bonded to a silicon atom, and examples include alkyltrialkoxysilanes and dialkyldialkoxysilanes.

[0028] Aminosilane coupling agents are silane coupling agents having an amino group, and examples include 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropylmethyldimethoxysilane, and 3-anilinopropyltrimethoxysilane.

[0029] Epoxysilane coupling agents are silane coupling agents having an epoxy group, and examples include 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0030] Vinylsilane coupling agents are silane coupling agents having a vinyl group, and examples include vinyltrialkoxysilanes such as vinyltrimethoxysilane and vinyltriethoxysilane, and styrylsilane coupling agents such as p-styryltrimethoxysilane.

[0031] If the heat dissipation filler (C1) is surface-treated with a silane coupling agent, the amount of silane coupling agent used may be 0.5 to 5.0 parts by mass, 0.6 to 3.0 parts by mass, or 0.7 to 1.5 parts by mass per 100 parts by mass of the heat dissipation filler before surface treatment.

[0032] Furthermore, if the heat dissipation filler (C1) is surface-treated with a silane coupling agent, it may be surface-treated beforehand or surface-treated during the preparation of the first component. An example of a method for surface treatment during the preparation of the first component is to add a silane coupling agent to a mixture of polyol (A) and the heat dissipation filler before surface treatment (integral blend method).

[0033] From the viewpoint of further improving thermal conductivity, the content of the heat dissipation filler (C1) is preferably 50 to 90% by mass, more preferably 70 to 90% by mass, and even more preferably 80 to 90% by mass in the first component.

[0034] The heat dissipation filler (C1) may be of any one type, or two or more types may be used in combination.

[0035] [Dispersant (D)] The first component contains a phosphate ester group-containing surfactant (d1) as a dispersant (D). The inclusion of the phosphate ester group-containing surfactant (d1) in the first component can suppress the increase in viscosity of the first component containing the polyol.

[0036] Examples of phosphate ester group-containing surfactants (d1) include phosphate esters having an oxyalkylene group, such as polyoxyalkylene alkyl ether phosphate esters, polyoxyalkylene alkylphenyl ether phosphate esters, and polyoxyalkylene styrene styrene-phenyl ether phosphate esters. Examples of oxyalkylene groups include oxyethylene groups, oxypropylene groups, and oxybutylene groups. Furthermore, from the viewpoint of further suppressing the viscosity increase of the first component containing the polyol, those having an oxyethylene group are preferred. Any one of the phosphate ester group-containing surfactants (d1) may be used, or two or more may be used in combination.

[0037] Examples of polyoxyalkylene alkyl ether phosphates include polyoxyethylene alkyl ether phosphates such as polyoxyethylene hexyl ether phosphate, polyoxyethylene octyl ether phosphate, polyoxyethylene nonyl ether phosphate, polyoxyethylene decyl ether phosphate, polyoxyethylene undecyl ether phosphate, polyoxyethylene dodecyl ether phosphate, polyoxyethylene tridecyl ether phosphate, and polyoxyethylene lauryl ether phosphate, as well as polyoxypropylene alkyl ether phosphates such as polyoxypropylene hexyl ether phosphate, polyoxypropylene octyl ether phosphate, polyoxypropylene nonyl ether phosphate, polyoxyethylene decyl ether phosphate, polyoxypropylene undecyl ether phosphate, polyoxypropylene dodecyl ether phosphate, polyoxypropylene tridecyl ether phosphate, and polyoxypropylene lauryl ether phosphate. The number of carbon atoms in the alkyl group in the polyoxyalkylene alkyl ether phosphate may be 5 to 20, 10 to 20, or 10 to 15.

[0038] Examples of polyoxyalkylene alkylphenyl ether phosphates include polyoxyethylene alkylphenyl ether phosphates such as polyoxyethylene hexylphenyl ether phosphate, polyoxyethylene octylphenyl ether phosphate, polyoxyethylene nonylphenyl ether phosphate, polyoxyethylene decylphenyl ether phosphate, polyoxyethylene undecylphenyl ether phosphate, polyoxyethylene dodecylphenyl ether phosphate, polyoxyethylene tridecylphenyl ether phosphate, and polyoxyethylene laurylphenyl ether phosphate, as well as polyoxypropylene alkylphenyl ether phosphates such as polyoxypropylene hexylphenyl ether phosphate, polyoxypropylene octylphenyl ether phosphate, polyoxypropylene nonylphenyl ether phosphate, polyoxypropylene decylphenyl ether phosphate, polyoxypropylene undecylphenyl ether phosphate, polyoxypropylene dodecylphenyl ether phosphate, polyoxypropylene tridecylphenyl ether phosphate, and polyoxypropylene laurylphenyl ether phosphate. The number of carbon atoms in the alkyl group of the polyoxyalkylene alkylphenyl ether phosphate ester may be 5 to 20, 10 to 20, or 10 to 15.

[0039] Examples of polyoxyalkylene styrene-phenyl ether phosphate esters include polyoxyethylene styrene-phenyl ether phosphate ester and polyoxypropylene styrene-phenyl ether phosphate ester.

[0040] The average number of repeating oxyalkylene groups in a phosphate ester having an oxyalkylene group may be, for example, 1 or more and 20 or less.

[0041] From the viewpoint of further suppressing the viscosity increase of the first component containing the polyol, the content of the phosphate ester group-containing surfactant (d1) is preferably 0.1 to 1.0% by mass, more preferably 0.3 to 0.7% by mass, and even more preferably 0.4 to 0.6% by mass in the first component.

[0042] From the viewpoint of further suppressing the viscosity increase of the first component containing the polyol, the content of the phosphate ester group-containing surfactant (d1) is preferably 0.01 to 3.00 parts by mass, more preferably 0.07 to 1.30 parts by mass, and even more preferably 0.10 to 1.00 parts by mass per 100 parts by mass of the heat dissipation filler (C1).

[0043] [Other ingredients] The first component may contain other components as long as they do not impair the purpose of this embodiment. Examples of such components include hygroscopic agents, defoaming agents, antioxidants, diluents, flame retardants, ultraviolet absorbers, colorants, and plasticizers.

[0044] Examples of hygroscopic agents include synthetic zeolites. The adsorbent content may be, for example, 0.1 to 3.0% by mass, 0.3 to 2.0% by mass, or 0.5 to 1.5% by mass in the first component.

[0045] Examples of defoaming agents include polybutene and silicone resin. The amount of defoaming agent may be, for example, 0.1 to 1.0% by mass or 0.3 to 0.7% by mass in the first component.

[0046] <Second component> [Polyisocyanate (B)] The second component contains polyisocyanate (B). The amount of polyisocyanate (B) in the second component may be 10-100% by mass, 10-55% by mass, 15-50% by mass, 15-30% by mass, or 20-30% by mass.

[0047] [Aromatic polyisocyanate (b1)] Polyisocyanate (B) includes aromatic polyisocyanate (b1). Examples of aromatic polyisocyanate (b1) include tolylene diisocyanate (TDI, e.g., 2,4-TDI, 2,6-TDI), diphenylmethane diisocyanate (MDI, e.g., 2,2'-MDI, 2,4'-MDI, 4,4'-MDI, monomeric MDI), polymethylene polyphenyl polyisocyanate (polymeric MDI), 4,4'-dibenzyl diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate (XDI), 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, and derivatives thereof. Aromatic polyisocyanate (b1) may be used individually or in combination of two or more.

[0048] Examples of polyisocyanate derivatives include modified forms such as isocyanurates, adducts, biurets, allophanates, and carbodiimides, as well as isocyanate-terminated prepolymers obtained by reacting polyisocyanates with polyols. These derivatives are also included in the concept of aromatic polyisocyanates (b1).

[0049] The content of aromatic polyisocyanate (b1) is preferably 70 to 100% by mass, more preferably 80 to 100% by mass, even more preferably 90 to 100% by mass, and particularly preferably 100% by mass in polyisocyanate (B).

[0050] From the viewpoint of improving the adhesion between PET and aluminum, aromatic polyisocyanates (b1) are preferably MDI and its derivatives. [Polyisocyanates other than aromatic polyisocyanates (b1) (b2)] Polyisocyanate (B) may also contain polyisocyanate (b2) other than aromatic polyisocyanate (b1). Examples of polyisocyanates other than aromatic polyisocyanates (b1) (b2) include alicyclic polyisocyanates such as isophorone diisocyanate (IPDI), dicyclohexylmethane 4,4'-diisocyanate (hydrogenated MDI), hydrogenated xylylene diisocyanate, 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, and 1,3-bis(isocyanate-methyl)cyclohexane, as well as aliphatic polyisocyanates such as tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2-methylpentane-1,5-diisocyanate, and 3-methylpentane-1,5-diisocyanate.

[0051] [Heat dissipation filler (C2)] The second component may include a heat dissipation filler (C2). The same heat dissipation filler (C2) as the heat dissipation filler (C1) can be used. The heat dissipation filler (C1) used in the first component and the heat dissipation filler (C2) used in the second component may be the same or different.

[0052] The heat dissipation filler (C2) is preferably surface-treated with a silane coupling agent. The method of surface treatment with the silane coupling agent, the silane coupling agent used, and the amount thereof may be the same as those for the heat dissipation filler (C1).

[0053] The content of the heat dissipation filler (C2) is preferably 50 to 85% by mass, more preferably 70 to 85% by mass, and even more preferably 70 to 80% by mass in the second component.

[0054] The total content of heat dissipation filler (C1) and heat dissipation filler (C2) is 75 to 90% by mass in the two-component curable polyurethane resin composition. From the viewpoint of further improving thermal conductivity, the total content of heat dissipation filler (C1) and heat dissipation filler (C2) is preferably 75 to 85% by mass, and more preferably 80 to 85% by mass, in the two-component curable polyurethane resin composition.

[0055] [Other ingredients] The second component may contain other components as long as they do not impair the purpose of this embodiment. Examples of such components include hygroscopic agents, defoaming agents, dispersants, antioxidants, diluents, flame retardants, ultraviolet absorbers, colorants, and plasticizers.

[0056] [Two-component curable polyurethane resin composition] In the two-component curable polyurethane resin composition of the present invention, the mass ratio of the second component to the first component (second component / first component) is preferably 5 / 100 to 500 / 100, more preferably 5 / 100 to 400 / 100, even more preferably 5 / 100 to 300 / 100, and particularly preferably 10 / 100 to 250 / 100.

[0057] In the two-component curable polyurethane resin composition of the present invention, the molar ratio (NCO / OH) of isocyanate groups to hydroxyl groups may be, for example, 0.75 to 1.30, 1.00 to 1.25, or 1.05 to 1.20.

[0058] The two-component curable polyurethane resin composition of the present invention is a two-component kit resin composition in which a first component and a second component are filled in separate containers. The first component and the second component, filled in separate containers, are mixed at the time of use, causing the polyol (A) and polyisocyanate (B) to react to form a polyurethane resin, which then hardens to become a cured product. In this case, heating may be used to harden the resin.

[0059] The applications of the two-component curable polyurethane resin composition of the present invention are not particularly limited, but from the viewpoint of improving thermal conductivity and adhesion, it can be used, for example, as a heat dissipation material in printed circuit boards and batteries. This heat dissipation material is obtained by curing the two-component curable polyurethane resin composition of the present invention. [Examples]

[0060] The present invention will be described in more detail below based on examples and comparative examples, but it is not limited thereto.

[0061] Two-component curable polyurethane resin compositions were prepared according to the formulations (parts by mass) shown in Tables 1-3 below. Details of the raw materials used in the examples and comparative examples are as follows.

[0062] [Polyol (a1)] • Exenol 430: Polyether polyol, manufactured by AGC Inc. (number average molecular weight = 430, hydroxyl value = 420 mgKOH / g, average number of functional groups = 3.0) • H-30: Castor oil polyol, manufactured by Ito Oil Co., Ltd., "URIC H-30" (number-average molecular weight = 947, hydroxyl value = 160 mgKOH / g, average number of functional groups = 2.7) Glycerin (molecular weight = 92, hydroxyl value = 181 mg KOH / g, number of functional groups = 3.0) • Excenol 1030: Polyether polyol, manufactured by AGC Inc. (number average molecular weight = 1000, hydroxyl value = 160 mgKOH / g, average number of functional groups = 3.0)

[0063] [Polyol (a2)] • Exenol 420: Polyether polyol, manufactured by AGC Inc. (number average molecular weight = 400, hydroxyl value = 280 mgKOH / g, average number of functional groups = 2.0) • Exenol 3030: Polyether polyol, manufactured by AGC Inc. (number average molecular weight = 3000, hydroxyl value = 56 mgKOH / g, average number of functional groups = 3.0) Pentaerythritol (molecular weight = 137, hydroxyl value = 1648 mgKOH / g, number of functional groups = 4.0)

[0064] [Aromatic polyisocyanate (b1)] • Polymeric MDI1: BASF INOAC Polyurethane Co., Ltd. "Foamlight NE-5000B" (Isocyanate value = 427.5 mg KOH / g) • Polymeric MDI2: "Millionate MR-200" manufactured by Tosoh Corporation (Isocyanate value = 417.5 mg KOH / g)

[0065] [Polyisocyanates other than aromatic polyisocyanates (b1) (b2)] • HDI: "Duranate TPA-100" manufactured by Asahi Kasei Corporation (isocyanate value = 308.6 mg KOH / g)

[0066] [Heat dissipation filler (C1) and heat dissipation filler (C2) (Heat dissipation fillers 1-4)] The following silane coupling agents were used to surface-treat the heat dissipation fillers. Note that the amounts (parts by mass) of heat dissipation fillers (C1) and (C2) in the table refer to the amounts (parts by mass) of the surface-treated product. The surface treatment method is as follows. An isopropyl alcohol solution of phenyltrimethoxysilane (KBM-103, manufactured by Shin-Etsu Chemical Co., Ltd.) was prepared (mass ratio of phenyltrimethoxysilane to isopropyl alcohol = 50 / 50). The prepared solution was sprayed onto 100 parts by mass of the heat dissipation filler before surface treatment so that the concentration of phenyltrimethoxysilane was 1 part by mass, and the mixture was mixed in powder form. Subsequently, the mixture was cured in an open system at 80°C for 1 hour to obtain a heat dissipation filler surface-treated with phenyltrimethoxysilane. • Heat dissipation filler 1: Aluminum hydroxide surface-treated with phenyltrimethoxysilane, surface-treated product of Nippon Light Metal Co., Ltd. "BX053" • Heat dissipation filler 2: Aluminum hydroxide surface-treated with phenyltrimethoxysilane, surface-treated product of "CW-375HT" manufactured by Sumitomo Chemical Co., Ltd. • Heat dissipation filler 3: Alumina surface-treated with phenyltrimethoxysilane, surface-treated product of "DAW-45" manufactured by Denka Co., Ltd. • Heat dissipation filler 4: Alumina surface-treated with phenyltrimethoxysilane, surface-treated product of "DAW-03" manufactured by Denka Co., Ltd.

[0067] [Heat dissipation filler (C1) and heat dissipation filler (C2) (Heat dissipation fillers 5-6)] The following silane coupling agents were used to surface-treat the heat dissipation fillers. Note that the amounts (parts by mass) of heat dissipation fillers (C1) and (C2) in the table refer to the amounts (parts by mass) of the surface-treated product. The surface treatment method is as follows. An isopropyl alcohol solution of 3-aminopropyltrimethoxysilane (KBM-903, manufactured by Shin-Etsu Chemical Co., Ltd.) was prepared (mass ratio of 3-aminopropyltrimethoxysilane to isopropyl alcohol = 50 / 50). The prepared solution was sprayed onto 100 parts by mass of heat dissipation filler before surface treatment so that the concentration of 3-aminopropyltrimethoxysilane was 1 part by mass, and the mixture was mixed in powder form. Subsequently, the mixture was cured in an open system at 80°C for 1 hour to obtain heat dissipation filler surface-treated with 3-aminopropyltrimethoxysilane. • Aluminum hydroxide surface-treated with the heat dissipation filler 5:3-aminopropyltrimethoxysilane, surface-treated product of Nippon Light Metal Co., Ltd. "BX053" • Aluminum hydroxide surface-treated with the heat dissipation filler 6:3-aminopropyltrimethoxysilane, surface-treated product of "CW-375HT" manufactured by Sumitomo Chemical Co., Ltd.

[0068] [Surfactants containing phosphate ester groups (d1)] • A215C: Phosphate ester group-containing surfactant (polyoxyalkylene alkyl ether phosphate ester), manufactured by Daiichi Kogyo Seiyaku Co., Ltd., "Prysurf A215C" • A219B: Phosphate ester group-containing surfactant (polyoxyalkylene alkyl ether phosphate ester), manufactured by Daiichi Kogyo Seiyaku Co., Ltd. "Prysurf A219B"

[0069] [Surfactants other than phosphate ester group-containing surfactants (d1) (d2)] • H-3606: Carboxylate-containing surfactant (polyoxyalkylene alkyl ether acetate), manufactured by Daiichi Kogyo Seiyaku Co., Ltd., "Prysurf H-3606" • EA-87: Nonionic surfactant (polyoxyalkylene styrene phenyl ether), manufactured by Daiichi Kogyo Seiyaku Co., Ltd., "Neugen EA-87"

[0070] [Desiccant] • 3A-B: Union Showa Co., Ltd. "Molecular Sieve 3A-B POWDER"

[0071] [Antifoaming agent] • LV-50: "Nisseki Polybutene LV-50" manufactured by ENEOS Material Co., Ltd. • KS-69: Manufactured by Shin-Etsu Chemical Co., Ltd.

[0072] The measurement and evaluation methods used in the examples are as follows:

[0073] [Viscosity of the first component (25℃)] Using a mixer (Sinky Co., Ltd. "Awatori Rentaro"), approximately 100g of the first component was mixed at 2000rpm for 1 minute. The viscosity was measured using a BH-type rotational viscometer (Toki Sangyo Co., Ltd.) in accordance with JIS Z 8803:2011. Specifically, the viscosity of the mixture at 25°C was measured at rotor No. 7, 1rpm, in a 25°C atmosphere, and the viscosity of the first component was evaluated according to the following criteria. A: Less than 500 Pa·s B: 500 Pa·s or more and less than 2000 Pa·s C: 2000 Pa·s or more and less than 4000 Pa·s D:4000Pa·s or more

[0074] [Thermal conductivity] A two-component curable polyurethane resin composition, obtained by mixing the first and second components, was poured into a 5mm thick mold and cured at 80°C for 16 hours to produce a 5mm thick resin sheet. This resin sheet was cut into 50mm x 50mm x 5mm sheets to be used as measurement samples. Measurements were performed using C-Therm's "TCi" in a 23°C atmosphere, and the thermal conductivity was evaluated according to the following criteria. A:2.5W / m·K or more B: 2.0 W / m·K or higher, less than 2.5 W / m·K C: 1.5 W / m·K or higher, less than 2.0 W / m·K D: Less than 1.5 W / m·K

[0075] [Adhesion (PET) and Adhesion (Aluminum)] Two standard test plates (25mm x 100mm x 3mm) were used, and the resin composition was applied so that the adhesive area was 25mm x 25mm and the adhesive layer thickness was 3mm. The two plates were then stacked and heated and cured at 60°C for 15 hours. After curing, the test specimens were subjected to a tensile shear test at 23°C (tensile speed 12.5mm / min) to measure the shear strength, and evaluated according to the following criteria. Adhesion (PET) was measured using a standard test plate made of polyethylene terephthalate (PET), and adhesion (aluminum) was measured using a standard test plate made of aluminum. Adhesion (PET) and adhesion (aluminum) were evaluated according to the following criteria. A: The pressure is 4.5 MPa or higher, or the standard test plate is destroyed. B: 2.5 MPa or more and less than 4.5 MPa C: 1.5 MPa or higher, less than 2.5 MPa D: Less than 1.5 MPa

[0076] [Table 1]

[0077] [Table 2]

[0078] [Table 3]

[0079] The results are shown in Tables 1-3.

[0080] Comparative Example 1 is an example in which a bifunctional polyol (a2) was used instead of polyol (a1). Although the viscosity and thermal conductivity of the first component were excellent, the adhesive properties were poor. Comparative Example 2 is an example in which a tetrafunctional polyol (a2) was used instead of polyol (a1). Although the thermal conductivity was excellent, the viscosity of the first component was high and the adhesive properties were poor. Comparative Example 3 is an example in which a polyol (a2) with a number-average molecular weight (Mn) of 3000 was used instead of polyol (a1). Although the thermal conductivity was excellent, the viscosity of the first component was high and the adhesive properties were poor. Comparative Example 4 is an example in which the first component... Polyol (a1) This is an example where the content of was formulated to be below the lower limit, and although the viscosity and thermal conductivity of the first component were excellent, the adhesive properties were poor.

[0081] Comparative Example 5 was an example in which the content of heat dissipation filler (C1) and heat dissipation filler (C2) in the two-component curable polyurethane resin composition was formulated to be below the lower limit. Although the viscosity and adhesion of the first component were excellent, the thermal conductivity was poor. Comparative Example 6 was an example in which aromatic isocyanate was not formulated. Although the viscosity and thermal conductivity of the first component were excellent, the adhesion was poor. Comparative Example 7 was an example in which phosphate ester group-containing surfactant was not formulated. The viscosity of the first component became high, making it impossible to prepare test specimens, and therefore the thermal conductivity and adhesion could not be evaluated. Comparative Example 8 was an example in which a non-carboxyl group-containing surfactant was formulated instead of a phosphate ester group-containing surfactant. The viscosity of the first component became high, making it impossible to prepare test specimens, and therefore the thermal conductivity and adhesion could not be evaluated. Comparative Example 9 was an example in which a nonionic surfactant was formulated instead of a phosphate ester group-containing surfactant. The viscosity of the first component became high, making it impossible to prepare test specimens, and therefore the thermal conductivity and adhesion could not be evaluated.

[0082] In contrast, Examples 1 to 22 exhibited low viscosity of the first component and excellent thermal conductivity, adhesion to PET, and adhesion to aluminum.

[0083] Furthermore, the various numerical ranges described in this specification can be any combination of their upper and lower limits, and all such combinations are described herein as preferred numerical ranges. Also, the description of a numerical range as "X~Y" means X or greater and Y or less.

[0084] Although embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their omissions, substitutions, and modifications are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

Claims

1. A first component comprising a polyol (A), a heat dissipation filler (C1), and a dispersant (D), A two-component curable polyurethane resin composition comprising a second component containing polyisocyanate (B), The polyol (A) has an average number of functional groups of 2.5 to 3.0 and a number-average molecular weight (Mn) It contains 55 to 100% by mass of polyol (a1) with a composition of 947 or less, The dispersant (D) comprises a phosphate ester group-containing surfactant (d1), The polyisocyanate (B) comprises an aromatic polyisocyanate (b1), The second component may include a heat dissipation filler (C2), A two-component curable polyurethane resin composition in which the total content of the heat dissipation filler (C1) and heat dissipation filler (C2) is 75 to 90% by mass of the two-component curable polyurethane resin composition.

2. The two-component curable polyurethane resin composition according to claim 1, wherein the aromatic polyisocyanate (b1) is at least one selected from the group consisting of diphenylmethane diisocyanate and polymethylene polyphenyl polyisocyanate.

3. The two-component curable polyurethane resin composition according to claim 1, wherein the phosphate ester group-containing surfactant (d1) is a polyoxyalkylene alkyl ether phosphate ester.

4. The two-component curable polyurethane resin composition according to claim 1, wherein the heat dissipation filler (C1) is surface-treated with a silane coupling agent.

5. The two-component curable polyurethane resin composition according to claim 1, wherein the second component contains a heat dissipation filler (C2).

6. A heat dissipation material obtained by curing a two-component curable polyurethane resin composition according to any one of claims 1 to 5.

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