Curable composition, urethane resin composition, and heat-releasing member

Abstract

To provide a curable composition, a urethane resin composition, and a heat-releasing member that achieve superior handling properties, excellent storage stability, and high thermal conductivity.SOLUTION: A curable composition comprises: a polyol, containing polyether polyol as an essential component; a polyisocyanate; nanosilica; a compound having a phosphate group; and a filler, wherein the total weight of the compound having a phosphate group is 0.1 to 5 pts.wt. relative to 100 pts.wt. of the filler, and wherein the polyether polyol is a polyoxyalkylene polyol.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a curable composition, a urethane resin composition obtained by curing the curable composition, and a heat dissipation member containing the urethane resin composition.

Background Art

[0002] Electronic devices are becoming more highly integrated and faster year by year, and accordingly, the demand for heat dissipation materials for heat countermeasures is increasing. If heat dissipation is insufficient, the normal operation of electronic devices and the like may be hindered, and there is a risk of causing deterioration, failure, and damage. As a heat dissipation material, a polyurethane resin composition containing a hydroxyl group-containing compound containing polybutadiene polyol, a specific polyisocyanate compound, and inorganic particles having high thermal conductivity is known (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the curable composition used as a heat dissipation material, the higher the volume concentration occupied by inorganic particles having high thermal conductivity and the higher the filling density, the better the thermal conductivity is exhibited. However, when inorganic particles having high thermal conductivity are blended in a high concentration in the paste, there is a problem that the viscosity and thixotropy increase, making coating or injection difficult. Furthermore, at present, there is a problem of storage stability in that inorganic particles having high thermal conductivity tend to settle, and the dispersion state of inorganic particles having high thermal conductivity in the curable composition becomes non-uniform.

[0005] An object of the present invention is to provide a curable composition having good handleability and excellent storage stability, a urethane resin composition having high thermal conductivity, and a heat dissipation member.

Means for Solving the Problems

[0006] As a result of intensive studies to solve the above problems, the present inventors have arrived at the present invention. That is, the present invention includes a polyol containing a polyether polyol as an essential component, a polyisocyanate, nanosilica, a compound having a phosphate group, and a filler, and the total weight of the compound having a phosphate group with respect to 100 parts by weight of the filler is 0.1 to 5 parts by weight. A curable composition, a urethane resin composition which is a cured product of the curable composition, and a heat dissipation member containing the urethane resin composition.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a curable composition having good handleability and excellent storage stability, a urethane resin composition having high thermal conductivity, and a heat dissipation member.

Modes for Carrying Out the Invention

[0008] The curable composition of the present invention includes a polyol containing a polyether polyol as an essential component, a polyisocyanate, nanosilica, a compound having a phosphate group, and a filler.

[0009] By using a polyether polyol as an essential component in the curable composition, the viscosity of the curable composition is lowered and the handleability is improved. As the polyol containing a polyether polyol as an essential component, a polyoxyalkylene polyol having an alkylene group is preferable from the viewpoint of the viscosity of the curable composition. Preferable examples of the polyoxyalkylene polyol include polyethylene glycol, polyoxypropylene glycol, polyoxyethylene-oxypropylene glycol, polytetramethylene glycol, polyoxytetramethylene-oxyethylene glycol, polyteoxytetramethylene-oxypropylene glycol, polyhexamethylene ether glycol, and polyoxypropylene glyceryl ether. The polyether polyol may be used alone or in combination of two or more kinds.

[0010] From the viewpoint of the flexibility of the resulting curable composition, the polyether diol is preferable as the polyether polyol.

[0011] From the viewpoint of viscosity, the number average molecular weight (Mn) of the polyether polyol is preferably from 100 to 10000, more preferably from 150 to 3000, and most preferably from 200 to 2000. The measurement conditions of Mn of the polyether polyol are as follows. Apparatus: High-temperature gel permeation chromatograph ["Alliance GPC V2000", manufactured by Waters Japan, Ltd.] Detector: Refractive index detector Solvent: Orthodichlorobenzene Reference substance: Polystyrene Sample concentration: 3 mg / ml Column stationary phase: PLgel 10 μm, two MIXED-B columns in series [manufactured by Polymer Laboratories] Column temperature: 135 °C

[0012] As the polyol contained in the curable composition of the present invention, a polyol other than the aforementioned polyether polyol may be contained. Examples of the polyol other than the polyether polyol include polyester polyol, polycarbonate polyol, and polyolefin polyol.

[0013] Examples of the polyester polyol include condensates of polyol [the aforementioned polyether polyol, aliphatic diol, polyvalent aliphatic polyol, alicyclic polyol, adducts of alkylene oxides (ethylene oxide, propylene oxide, 1,2-, 1,3-, 2,3- or 1,4-butylene oxide, etc., which may be abbreviated as AO below) of alicyclic polyol, etc.] and polycarboxylic acid. Examples of polycarboxylic acids include chain aliphatic polycarboxylic acids having 2 to 20 carbon atoms [oxalic acid, malonic acid, dipropylmalonic acid, succinic acid, 2,2-dimethylsuccinic acid, glutaric acid, 2-methylglutaric acid, 2,2-dimethylglutaric acid, 2,4-dimethylglutaric acid, 3-methylglutaric acid, 3,3-dimethylglutaric acid, 3-ethyl-3-methylglutaric acid, adipic acid, 3-methyladipic acid, pimelic acid, 2,2,6,6-tetramethylpimelic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, pentadecanedioic acid, tetradecanedioic acid, heptadecanedioic acid, octadecanedioic acid, nonadecanedioic acid, eicosanedioic acid, etc.]; alicyclic polycarboxylic acids having 5 to 20 carbon atoms [cyclopropanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, cyclohexenedicarboxylic acid, dicyclohexyl-4,4'-dicarboxylic acid, and camphoric acid]; aromatic polycarboxylic acids having 8 to 20 carbon atoms [terephthalic acid, isophthalic acid, 2-methylterephthalic acid, 4,4-stilbenedicarboxylic acid, naphthalenedicarboxylic acid, 4,4-biphenyldicarboxylic acid, phthalic acid, diphenyl ether dicarboxylic acid, etc.]. They can be obtained from the market, such as Kuraray Polyol P-2010 (manufactured by Kuraray Co., Ltd.).

[0014] Examples of aliphatic diols include aliphatic diols having 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms.

[0015] Examples of aliphatic polyols with a valence of 3 or higher include alcohols with a valence of 3 or higher among aliphatic polyols having 3 to 20 carbon atoms, such as glycerin and pentaerythritol, preferably glycerin.

[0016] Examples of alicyclic polyols include alicyclic polyols having 4 to 16 carbon atoms (1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and hydrogenated bisphenol A).

[0017] Examples of the AO adduct of the alicyclic polyol include compounds obtained by adding AO to the above alicyclic polyol. As the AO, the same ones as those exemplified in the description of the polyether polyol can be used, and the preferred ones are also the same.

[0018] Examples of the polycarbonate polyol include reaction products of a polyol [the above polyether polyol, aliphatic diol, aliphatic polyol having a valence of 3 or more, alicyclic polyol, AO adduct of alicyclic polyol, etc.] and phosgene, etc., and they can be obtained from the market as Kuraray Polyol C-590, C2090 [manufactured by Kuraray Co., Ltd.], etc.

[0019] Examples of the polyolefin polyol include polybutadiene polyol, hydrogenated polybutadiene diol, etc.

[0020] From the viewpoint of the physical properties of the resin after curing, the polyol preferably has at least 2 or more hydroxyl groups on average per molecule.

[0021] When the polyol contained in the curable composition contains a polyether polyol and a polyol other than the polyether polyol, the weight of the polyol other than the polyether polyol with respect to 100 parts by weight of the polyether polyol is preferably 90 to 200 parts by weight, and more preferably 100 to 150 parts by weight.

[0022] Examples of the polyisocyanate include chain aliphatic polyisocyanate, alicyclic polyisocyanate, aromatic polyisocyanate, dimers of these polyisocyanates, and isocyanurate forms of these polyisocyanates, etc.

[0023] Examples of the chain aliphatic polyisocyanate include chain aliphatic polyisocyanates having 4 to 20 carbon atoms, and preferably include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate.

[0024] Examples of the alicyclic polyisocyanate include alicyclic polyisocyanates having 6 to 17 carbon atoms, and preferably include isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, bis(2-isocyanatoethyl)-4-cyclohexene-1,2-dicarboxylate, and 2,5- or 2,6-norbornane diisocyanate. The alicyclic polyisocyanate can be obtained from the market, such as Desmodur I [Sumitomo Bayer Urethane Co., Ltd.].

[0025] Examples of the aromatic polyisocyanate include aromatic polyisocyanates having 8 to 22 carbon atoms, and preferably include 1,3- or 1,4-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate (TDI), 4,4'- or 2,4'-diphenylmethane diisocyanate (MDI), m- or p-isocyanatophenylsulfonyl isocyanate, 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, m- or p-isocyanatophenylsulfonyl isocyanate, m- or p-xylylene diisocyanate (XDI), and α,α,α',α'-tetramethylxylylene diisocyanate (TMXDI).

[0026] Dimers of polyisocyanates include dimers of polyisocyanates (such as the above-mentioned linear aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates). Dimers of polyisocyanates can be obtained from the market, such as A201H [Asahi Kasei Corporation].

[0027] Isocyanurate forms of polyisocyanates include trimers of polyisocyanates (such as the above-mentioned linear aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates). Isocyanurate forms of polyisocyanates can be obtained from the market, such as TLA-100 [Asahi Kasei Corporation].

[0028] Among polyisocyanates, from the perspective of excellent moldability, linear aliphatic polyisocyanates, alicyclic polyisocyanates, dimers of linear aliphatic polyisocyanates, dimers of alicyclic polyisocyanates, isocyanurate forms of linear aliphatic polyisocyanates, and isocyanurate forms of alicyclic polyisocyanates are preferred. The polyisocyanate may be used alone or in combination of two or more.

[0029] The proportion of the total weight of polyol and polyisocyanate in the curable composition is preferably 3 to 30% by weight, more preferably 3 to 20% by weight, and most preferably 5 to 8% by weight based on the weight of the curable composition.

[0030] The isocyanate index [total number of moles of isocyanate groups in polyisocyanate / total number of moles of hydroxyl groups in polyol] of polyol and polyisocyanate in the curable composition is preferably 0.8 to 2.0, and more preferably 0.8 to 1.5. When the isocyanate index is within the above range, the curability of the curable composition and the flexibility of the cured product are good.

[0031] The nanosilica in the present invention refers to nano-sized silicon dioxide particles having an average particle size of 1 μm or less, and the form and shape are not particularly limited. By using nanosilica in the curable composition, the viscosity and workability can be adjusted, and the thermal expansion coefficient can be reduced while improving the adhesiveness. Examples of nanosilica include fumed silica, precipitated silica, gel silica, and colloidal silica. These may be used alone or in combination of two or more. Among these, it is preferable to include fumed silica from the viewpoint of aggregability and particle size. Examples of commercially available fumed silica include the Aerosil series manufactured by Nippon Aerosil Co., Ltd. Fumed silica includes hydrophilic fumed silica that has not been surface-treated, and hydrophobic fumed silica whose silanol group portion has been chemically surface-treated with silane and / or siloxane. Nanosilica preferably contains one or both of these hydrophilic fumed silica and hydrophobic fumed silica.

[0032] The average particle size of the nanosilica is, for example, 1 nm to 100 nm, preferably 2 nm to 50 nm, and more preferably 5 to 30 nm. It is believed that by adjusting the size to this range, the curable composition can obtain thixotropy even with a small amount added. The average particle size here means the average primary particle size determined by a laser diffraction method.

[0033] The BET specific surface area of ​​the nano-silica is preferably 10 mm 2 / g~300mm 2 / g, more preferably 50 mm 2 / g~250mm 2 / g, more preferably 80 mm 2 / g~230mm 2 / g. The BET specific surface area of ​​nanosilica is measured based on JIS Z8830:2013.

[0034] The weight of the nanosilica based on 100 parts by weight of the total of the polyol and the polyisocyanate is preferably 0.01 to 5 parts by weight, more preferably 0.1 to 3 parts by weight. If it is 0.01 part by weight or more, the thixotropic property is good, and if it is 5 parts by weight or less, the discharge property is good.

[0035] The weight of the nanosilica based on 100 parts by weight of the curable composition is preferably 0.01 to 5 parts by weight, more preferably 0.1 to 1 part by weight. If it is 0.01 part by weight or more, the thixotropic property is good, and if it is 5 parts by weight or less, the discharge property is good.

[0036] The curable composition of the present invention contains a compound having a phosphate group. By using a compound having a phosphate group in the curable composition, the dispersibility of the filler becomes good.

[0037] In the curable composition of the present invention, the total weight of the compound having a phosphate group based on 100 parts by weight of the filler is 0.1 to 5 parts by weight, preferably 0.2 to 3 parts by weight, and more preferably 0.3 to 1.0 part by weight. If it is less than 0.1 part by weight, the dispersibility of the filler becomes poor, and if it is 5 parts by weight or more, curing failure occurs.

[0038] Preferred compounds having a phosphate group include phosphate esters. More preferred phosphate esters include phosphate esters represented by the following general formula (1). [Chemical formula] [In general formula (1), R 1 is a hydrogen atom, an alkyl group having 2 to 20 carbon atoms, or an alkenyl group having 2 to 20 carbon atoms, and a part of the hydrogen atoms of the alkyl group or the alkenyl group may be substituted with a halogen atom. A 1 O is an alkyleneoxy group having 2 to 3 carbon atoms, n1 is an integer of 3 to 15, and R 2 is a hydrogen atom or -(A 2 O) n2 R 3 (R3 is an alkyl group having 2 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, and a part of the hydrogen atoms of the alkyl group or alkenyl group may be substituted with a halogen atom. A 2 O is an alkyleneoxy group having 2 to 3 carbon atoms, and n2 is an integer of 3 to 15).]

[0039] In general formula (1), R 1 is a hydrogen atom, an alkyl group having 2 to 20 carbon atoms, or an alkenyl group having 2 to 20 carbon atoms, and a part of the hydrogen atoms of the alkyl group or alkenyl group may be substituted with a halogen atom. Examples of the alkyl group having 2 to 20 carbon atoms include an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group, etc., and each of them may be linear or branched. Examples of the alkenyl group having 2 to 20 carbon atoms include an ethenyl group, a propenyl group, a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octenyl group, a nonenyl group, a decenyl group, an undecenyl group, a dodecenyl group, a tridecenyl group, a tetradecenyl group, a pentadecenyl group, a hexadecenyl group, a heptadecenyl group, and an octadecenyl group, etc., and these may be linear or branched, and the position of the double bond is not limited. As the halogen atom, a fluorine atom is preferable. R 1 may be linear or branched, but is preferably linear. Further, from the viewpoints of the mechanical strength of the cured product of the curable composition and the dispersibility of the filler, etc., an alkyl group having 12 to 18 carbon atoms is preferable.

[0040] In general formula (1), A 1 O means an alkyleneoxy group having 2 to 3 carbon atoms, and examples include an ethyleneoxy group and a propyleneoxy group. Among these, from the viewpoint of dispersibility, an ethyleneoxy group is preferable. n1 is an integer from 3 to 15, preferably from 3 to 13, more preferably from 4 to 11, from the viewpoint of good dispersibility of the filler and good mechanical strength of the cured product.

[0041] R 2 is a hydrogen atom or -(A 2 O) n2 R 3 (R 3 is an alkyl group having 2 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, and a part of the hydrogen atoms of the alkyl group or alkenyl group may be substituted with a halogen atom. A 2 O is an alkyleneoxy group having 2 to 3 carbon atoms, and n2 is an integer from 3 to 15). R 3 As R 1 the same ones as those of R A 2 As A 1 O, the same ones as those of A R 2 When R 2 is a hydrogen atom, the compound of the general formula (1) is a monoester, and when R 2 O) n2 R 3 is, the compound of the general formula (1) is a diester. Further, when R 2 is -(A 2 O) n2 R 3 in the case of, R 1 and R 3 may be the same or different. n1 and n2 may be the same or different.

[0042] As the phosphate ester represented by the general formula (1), two or more different ones of R 1 may be mixed and used, or a monoester (R 2 is H) and a diester (R 2 is -(A 2 O) n2 R 3) The mixture of may also be used. The phosphate ester represented by the general formula (1) is generally obtained as a mixture of a monoester and a diester (mono / di mixture). Further, salts of the phosphate ester represented by the general formula (1) (metal salts such as sodium, potassium, and magnesium, ammonium salts, etc.) can also be used.

[0043] Preferred examples of the phosphate ester represented by the general formula (1) include alkyl ether phosphate ester, alkyl phosphate ester, alkyl fluoride ether phosphate ester, alkyl fluoride phosphate ester, etc., and alkyl ether phosphate ester is more preferred. The phosphate ester represented by the general formula (1) can be obtained by phosphorylating a polyether and phosphorus oxide. Commercially available products include Disparon DA-375 [manufactured by Kusumoto Chemicals, Ltd.], Pricerf A208N [manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.], Phosphanol RL-210 [manufactured by Toho Chemical Industry Co., Ltd., R 1 ,R 3 :-C 18 H 37 、A 1 O,A 2 O: ethyleneoxy group, n1, n2: 2, mono / di mixture], Phosphanol RS-710 [manufactured by Toho Chemical Industry Co., Ltd., R 1 、R 3 : C18 alkyl group, A 1 O,A 2 O: ethyleneoxy group, n1, n2: 9, mono / di mixture], Phosphanol RS-410 [manufactured by Toho Chemical Industry Co., Ltd., R 1 ,R 3 : C12-15 alkyl group, A 1 O,A 2 O: ethyleneoxy group, n1, n2: 3, mono / di mixture], etc. and can be obtained.

[0044] The curable composition of the present invention contains a filler. Preferred fillers include boron nitride, aluminum nitride, aluminum oxide, magnesium oxide, and aluminum hydroxide. By using these fillers, the heat dissipation property becomes good when the cured product of the curable composition is used as a heat dissipation member.

[0045] Since the curable composition of the present invention uses a compound having a phosphate group, the dispersibility of the filler in the curable composition is good, and thus it has excellent handleability even when containing the filler at a high concentration. And by changing the type of the filler, a curable composition can be obtained which has functions other than heat dissipation according to the type of the filler, has good handleability, and is excellent in storage stability. For example, by containing carbon or metal as the filler, a curable composition with high conductivity can be formed; by containing a metal oxide and / or a metal hydroxide, a curable composition with high insulation can be formed; by containing polyimide or polyethylene, a curable composition with low dielectric can be formed; by containing barium titanate and / or lead zirconate titanate, a curable composition with high dielectric can be formed; by containing ammonium polyphosphate and / or a halide, a curable composition with high flame retardancy can be formed; by containing titanium black, a curable composition with high light-shielding property can be formed; by containing titanium oxide and / or zirconium oxide, a curable composition with high refractive property can be formed; by containing glass fiber and carbon fiber, a curable composition with high strength can be formed; by containing silver salt, copper salt and zinc salt, a curable composition with high antibacterial property can be formed; by containing microballoons, a curable composition with high lightweight property can be formed.

[0046] The shape of the filler contained in the curable composition of the present invention is not particularly limited, and fibrous and particulate ones can be preferably used. In the case of particles, spherical, plate-shaped, needle-shaped or amorphous (obtained by crushing etc.) particles can be used. From the viewpoint of excellent moldability, spherical particles are preferable as the shape of the filler.

[0047] When the filler is spherical particles, the volume average particle diameter of the filler [D50: the particle diameter at which the integrated particle amount in the particle size distribution based on volume becomes 50%] is preferably 0.01 to 200 μm, more preferably 0.1 to 150 μm, from the viewpoint of excellent moldability and the like. The volume average particle diameter of the filler can be measured using a laser diffraction particle size distribution measuring device [SALD-2000A manufactured by Shimadzu Corporation, LA-920 manufactured by Horiba, Ltd., etc.]. When components other than the filler are dissolved in the solvent, the solution of the composition may be measured.

[0048] The curable composition of the present invention contains 40 to 97% by weight, preferably 50 to 80% by weight, most preferably 55 to 75% by weight of the filler based on the weight of the curable composition. By the filler content being 40% by weight or more, the thermal conductivity of the cured product of the curable composition can be made good, and by making it 97% by weight or less, the moldability can be made good. If the filler content is less than 40% by weight, the thermal conductivity of the cured product may become insufficient, and if it exceeds 97% by weight, the moldability may deteriorate.

[0049] The curable composition of the present invention may contain other components in addition to the polyol, polyisocyanate, nanosilica, compound having a phosphate group, and filler. Examples of the other components include surfactants, plasticizers, and urethanization catalysts. The curable composition may further contain, as other components, known additives used in urethane resins (antioxidants and ultraviolet absorbers described in JP-A-2018-076537), general dehydrating agents such as zeolite, and colorants.

[0050] As the surfactant, polyoxyalkylene type nonionic surfactants (E1), ester type nonionic surfactants (E2), anionic surfactants (E3), and cationic surfactants (E4) can be preferably used.

[0051] Examples of the polyoxyalkylene type nonionic surfactant (E1) include AO adducts (preferably with an addition mole number of 1 to 30) of aliphatic alcohols (having 4 to 30 carbon atoms), alkyl (having 1 to 30 carbon atoms) phenols, aliphatic (having 4 to 30 carbon atoms) amines, or aliphatic (having 4 to 30 carbon atoms) amides. Preferred aliphatic alcohols constituting the polyoxyalkylene type nonionic surfactant (E1) include n-, i-, sec- or t-butanol, octanol, and dodecanol, etc. Preferred alkyl phenols include phenol, methylphenol, and nonylphenol, etc. Preferred aliphatic amines include laurylamine and methylstearylamine, etc. Preferred aliphatic amides include stearic acid amide, etc.

[0052] Examples of the ester type nonionic surfactant (E2) include ester compounds of fatty acids having 4 to 30 carbon atoms (such as lauric acid, stearic acid, and oleic acid) and polyhydric alcohols excluding sucrose, sorbitol, and glycerin.

[0053] Examples of the anionic surfactant (E3) include carboxylate type, sulfate ester type, and sulfonate type. Examples of the carboxylate type include alkali metal salts of the above fatty acids having 4 to 30 carbon atoms, and alkali metal salts of polyoxyalkylene alkyl ether carboxylic acids, etc. Examples of the sulfate ester type include alkali metal sulfate esters of the above aliphatic alcohols having 4 to 30 carbon atoms or AO adducts of aliphatic alcohols. Examples of the sulfonate type include alkali metal sulfonates of alkyl phenols. In the market, it can also be obtained as polyether carboxylic acid [manufactured by Kao Corporation, KAOH AKIPO RLM-100], etc.

[0054] Examples of the cationic surfactant (E4) include primary to tertiary amine salt types and quaternary ammonium salt types. Examples of the primary to tertiary amine salt types include hydrochlorides of aliphatic amines having 4 to 30 carbon atoms [primary (such as laurylamine), secondary (such as dibutylamine), and tertiary amines (such as dimethylstearylamine), etc.], inorganic acid (such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid, etc.) salts of monoesters of triethanolamine and fatty acids having 4 to 30 carbon atoms, etc. Examples of the quaternary ammonium salt type include inorganic acid salts of quaternary ammonium having 4 to 30 carbon atoms (such as butyltrimethylammonium, diethyllaurylmethylammonium, dimethyldistearylammonium, etc.). It can also be obtained from the market, such as Nopcosperse 092 [manufactured by San Nopco Ltd., cationic surfactant], etc.

[0055] When containing a surfactant, it is preferably contained in an amount of 0.001 to 30 parts by weight, more preferably 0.01 to 10 parts by weight, and particularly preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the curable composition.

[0056] Examples of the plasticizer include phthalate plasticizers [such as diisononyl phthalate, di-(2-ethylhexyl) phthalate, diisodecyl phthalate, butylbenzyl phthalate, etc.], fatty acid ester plasticizers [such as di-(2-ethylhexyl) adipate, di-n-decyl adipate, di-(2-ethylhexyl) azelate, dibutyl sebacate, di-(2-ethylhexyl) sebacate, etc.], benzoate plasticizers [such as polyethylene glycol benzoate], epoxy plasticizers such as epoxidized soybean oil, trimellitate plasticizers, pyromellitate plasticizers, polyester plasticizers, sulfonic acid ester plasticizers, etc. It can also be obtained from the market, such as diisononyl phthalate [manufactured by Aekyung Petrochemical Co., Ltd., DINP], polyethylene glycol benzoate [manufactured by Sanyo Chemical Industries, Ltd., EB-300], etc.

[0057] When containing a plasticizer, it is preferably contained in an amount of 1 to 100 parts by weight, more preferably 1 to 70 parts by weight, and most preferably 1 to 20 parts by weight, based on 100 parts by weight of the curable composition.

[0058] Examples of the urethanization catalyst include amine catalysts [triethylenediamine, N-ethylmorpholine, diethylethanolamine, 1,8-diazabicyclo(5,4,0)undecene-7, etc.] and metal catalysts [bismuth tris(2-ethylhexanoate), stannous octoate, dibutyltin dilaurate, lead octoate, etc.]. It is also possible to obtain from the market as a bismuth catalyst [manufactured by Nitto Kasei Co., Ltd., Neostan U-600], etc.

[0059] When containing a urethanization catalyst, the total weight of the urethanization catalyst based on 100 parts by weight of the total weight of the polyol and the polyisocyanate is preferably 10 parts by weight or less, more preferably 0.01 to 8 parts by weight, particularly preferably 0.5 to 8 parts by weight, and most preferably 0.5 to 5 parts by weight.

[0060] The present invention may be a two-component curable composition comprising a combination of a first agent and a second agent. A two-component curable composition is a curable composition that is cured by mixing two components at a specific mixing ratio.

[0061] The first agent in the two-component curable composition contains a polyol having a polyether polyol as an essential component, a compound having a phosphate group, and a filler, and the second agent contains a polyisocyanate, nanosilica, a compound having a phosphate group, and a filler. Note that the first agent may also contain nanosilica.

[0062] The content of the polyether polyol in the first agent is preferably 1 to 40% by weight, more preferably 2 to 35% by weight, and most preferably 5 to 30% by weight based on the weight of the first agent. When the content of the polyether polyol in the first agent is 1% by weight or more, the resin strength after curing is good, and when it is 40% by weight or less, the handleability is good.

[0063] The content of the polyisocyanate in the second agent is preferably 1 to 60% by weight, more preferably 5 to 50% by weight, and most preferably 10 to 45% by weight based on the weight of the second agent. When the content of the polyisocyanate in the second agent is 1% by weight or more, the resin strength after curing is good, and when it is 15% by weight or less, the handleability is good.

[0064] The total weight of the compound having a phosphate group with respect to 100 parts by weight of the filler in the first agent is 0.1 to 5 parts by weight, preferably 0.2 to 4 parts by weight, and more preferably 0.3 to 3.0 parts by weight. When it exceeds 0.1 part by weight, the dispersibility of the filler is good, and when it is 5 parts by weight or less, the curing is good.

[0065] The total weight of the compound having a phosphate group with respect to 100 parts by weight of the filler in the second agent is 0.1 to 5 parts by weight, preferably 0.2 to 4 parts by weight, and more preferably 0.3 to 3.0 parts by weight. When it exceeds 0.1 part by weight, the dispersibility of the filler is good, and when it is 5 parts by weight or less, the curing is good.

[0066] The content of the filler in the first agent is preferably 50 to 95% by weight, more preferably 55 to 90% by weight, and most preferably 60 to 80% by weight based on the weight of the first agent. When the content of the filler in the first agent is 50% by weight or more, the thermal conductivity is good, and when it is 95% by weight or less, the handleability is good.

[0067] The content of the filler in the second agent is preferably 60 to 95% by weight, more preferably 70 to 80% by weight based on the weight of the second agent. When the content of the filler in the first agent is 60% by weight or more, the thermal conductivity is good, and when it is 95% by weight or less, the handleability is good.

[0068] The first agent is obtained by uniformly mixing a polyether polyol, a compound having a phosphate group, a filler, a polyol other than the polyether polyol, and other components (nanosilica, surfactant, plasticizer, urethanization catalyst, etc.) that are used as necessary using a known mixing device (a mixing tank with a stirring device, etc.). Each component may be mixed all at once, or any two or more components may be mixed in advance and the remaining components (the remaining components may be a mixture) may be mixed.

[0069] The second agent is obtained by uniformly mixing a polyisocyanate, a compound having a phosphate group, a filler, and nanosilica, and other components (surfactant, plasticizer, urethanization catalyst, dehydrating agent, etc.) that are used as necessary using a known mixing device (a mixing tank with a stirring device, etc.). Each component may be mixed all at once, or any two or more components may be mixed in advance and the remaining components (the remaining components may be a mixture) may be mixed.

[0070] The thixotropy index of the curable composition at 23°C is preferably 1 to 20, more preferably 2 to 10, and most preferably 2 to 5. When the thixotropy index is within this range, when a polyol having a polyether polyol as an essential component and a polyisocyanate are mixed to form a curable composition, it is easy to mix uniformly and has excellent handleability. Furthermore, since the viscosity at a low shear rate increases, sedimentation of the filler is suppressed and the storage stability is improved. The thixotropy index can be controlled by the filling amount of nanosilica or the filler.

[0071] In the present invention, thixotropy refers to a property where the viscosity is relatively high in a steady state (for example, a state where no shear stress is applied), the viscosity decreases when a shear stress is applied, and the viscosity returns to its original value when the application of the shear stress is stopped. Thixotropy is represented by a thixotropy index TI measured by a dynamic viscoelasticity measuring device (for example, a BH type viscometer manufactured by Toki Sangyo Co., Ltd.). In the present embodiment, the thixotropy index TI is defined by the following formula (1). TI = (viscosity at a liquid temperature of 23 °C and a shear rate of 1 / s) / (viscosity at a liquid temperature of 23 °C and a shear rate of 10 / s) … (1) The closer the thixotropy index TI is to 1, the more it exhibits the behavior of a Newtonian liquid, and the larger the thixotropy index TI, the higher the thixotropy.

[0072] The two-component curable composition can obtain a cured product by mixing a first agent and a second agent and subjecting them to a urethanization reaction by a known method on an arbitrary substrate or in a mold having a shape according to the purpose. The mixing of the first agent and the second agent may be performed manually or by a known mixing device (such as a container with a stirring device), or may be continuously performed using a known two-component mixing supply device.

[0073] The urethane resin composition of the present invention is a cured product of the curable composition of the present invention. The urethane resin composition of the present invention is a urethane resin obtained by curing the above-described curable composition by a known method.

[0074] The curable composition of the present invention has good handleability, excellent storage stability, and high thermal conductivity, and thus is useful for fuel cell separators, lithium-ion battery materials, TIM for power devices, LED heat dissipation materials, smartphone casings, members for high-frequency amplifiers, low dielectric constant and low dielectric tangent materials for electrical and electronic devices such as 5G and 6G.

Examples

[0075] Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. In the following, "parts" represent parts by weight.

[0076]

Table 1

[0077] <Examples 1 to 4 and Comparative Examples 1 to 4> In a reaction vessel capable of stirring, each component shown in Table 1 was mixed in the blending amounts shown in Table 1 to prepare a first agent and a second agent. Next, the first agent and the second agent were mixed at 2000 rpm for 60 seconds with a planetary mixer "Avatore Rintaro ARV-310P" until uniform, to obtain the compositions of Examples 1 to 2 and the curable compositions of Comparative Examples 1 to 2. A part of the curable composition immediately after mixing was sampled, and its viscosity (unit: Pa·s) at each shear rate was measured using a rheometer "MCR302, manufactured by Anton Paar". The measurement temperature was 23°C, and a PP50 processed in a grid pattern was used as the measurement jig. The thixotropy index was obtained by dividing the viscosity at 10 / s by the viscosity at 1 / s of the obtained viscosities. The curable composition was poured into a molding mold (1 cm in length × 1 cm in width × 0.2 cm in depth) to fill it, pressed with a press machine, and allowed to stand at 25°C for 24 hours to cause a reaction. Each urethane resin sheet of Examples 3 to 4 was obtained from each composition of Examples 1 to 2, and each urethane resin sheet of Comparative Examples 3 to 4 was obtained from the compositions of Comparative Examples 1 to 2. For those that could be molded, the thermal conductivity was evaluated by the following method. The thermal conductivity of Example 3 was 1.3 W / m·K, the thermal conductivity of Example 4 was 0.9 W / m·K, the thermal conductivity of Comparative Example 3 was 1.3 W / m·K, and the thermal conductivity of Comparative Example 4 was 0.9 W / m·K.

[0078] The composition of the raw materials described by trade name in Table 1 is as follows. ·PP-200: (Trade name: Sunnex), polyoxyalkylene polyol, molecular weight: 200, number of hydroxyl groups: 2, manufactured by Sanyo Chemical Industries, Ltd. · PK-400: (Trade name: Sunnex), polyoxyalkylene polyol, molecular weight: 200, number of hydroxyl groups: 2, manufactured by Sanyo Chemical Industries, Ltd. · TLA-100: (Trade name: Duranate), trimer of hexamethylene diisocyanate, manufactured by Asahi Kasei Corporation · A201H: (Trade name: Duranate), dimer of hexamethylene diisocyanate, manufactured by Asahi Kasei Corporation · EB-300Y: polyethylene glycol benzoate, manufactured by Sanyo Chemical Industries, Ltd. · Phosphanol RS-710: polyoxyethylene alkyl (12 - 15) ether phosphate, manufactured by Toho Chemical Industry Co., Ltd. · U-600: (Trade name: Neostan), bismuth catalyst, manufactured by Nitto Kasei Co., Ltd. · irganox1135: hindered phenol antioxidant, manufactured by BASF Japan Ltd. · KAL3AB: zeolite, manufactured by Union Carbide Japan K.K. · SB-93: aluminum hydroxide, average particle size: 100 μm, manufactured by Nippon Light Metal Co., Ltd. · CW-310LV: aluminum hydroxide, average particle size: 10 μm, manufactured by Sumitomo Chemical Co., Ltd. · C-301N: aluminum hydroxide, average particle size: 1.5 μm, manufactured by Sumitomo Chemical Co., Ltd. · R972: nanosilica, average particle size: 17 nm, manufactured by Nippon Aerosil Co., Ltd.

[0079] <Thermal conductivity> After allowing each urethane resin sheet to stand at 25°C for 2 hours, the thermal conductivity (unit: W / m·K) was measured by the laser flash method using a thermal conductivity meter "Xenon Flash Analyzer LFA447 NanoFlash, manufactured by Netzsch Japan Co., Ltd.". A higher thermal conductivity indicates better heat dissipation performance.

[0080] The compositions of Examples 1 to 2 had better thixotropy indices than the compositions of Comparative Examples 1 to 2. When the thixotropy index is good, it can be said that when a polyol and a polyisocyanate are mixed to form a curable composition, they are easily mixed uniformly and have excellent handleability. Furthermore, since the viscosity at a low shear rate increases, it can be said that the sedimentation of the filler is suppressed and the storage property is improved. From these results, it was found that according to the curable composition of the present invention, it is possible to provide a urethane resin and a heat radiating member excellent in thermal conductivity, handleability, and storage stability.

Claims

1. A polyol containing a polyether polyol as an essential component, a polyisocyanate, nanosilica, a compound having a phosphate group, and a filler, wherein the total weight of the compound having a phosphate group with respect to 100 parts by weight of the filler is 0.1 to 5 parts by weight, a curable composition.

2. The curable composition according to claim 1, wherein the polyether polyol is a polyoxyalkylene polyol.

3. The curable composition according to claim 1, wherein the polyol contains a polyol other than the polyether polyol.

4. The curable composition according to claim 1, wherein the weight of the nanosilica with respect to 100 parts by weight of the total weight of the polyol and the polyisocyanate is 0.01 to 5 parts by weight.

5. The curable composition according to claim 1, wherein the compound having a phosphate group is a phosphate ester.

6. The curable composition according to claim 5, wherein the phosphate ester is a compound represented by the following general formula (1). 【Chemical 1】 [In general formula (1), R １ is a hydrogen atom, an alkyl group having 2 to 18 carbon atoms, or an alkenyl group having 2 to 18 carbon atoms, and A １ O is an alkyleneoxy group having 2 to 3 carbon atoms, n1 is an integer of 3 to 15, and R ２ is a hydrogen atom or -(A ２ O) ｎ２ R ３ (R ３ is an alkyl group having 2 to 18 carbon atoms, or an alkenyl group having 2 to 18 carbon atoms, A ２ O is an alkyleneoxy group having 2 to 3 carbon atoms, and n2 is an integer of 3 to 15).]

7. The curable composition according to claim 1, having a thixotropy index at 23 °C of 1 to 20.

8. A two-component curable composition comprising a combination of a first agent and a second agent, wherein the first agent contains a polyol containing a polyether polyol as an essential component, nanosilica, a compound having a phosphate group, and a filler, and the second agent contains a polyisocyanate, nanosilica, a compound having a phosphate group, and a filler, the curable composition according to claim 1.

9. The curable composition according to claim 1, having an isocyanate index of 0.8 to 1.

2.

10. A urethane resin which is a cured product of the curable composition according to any one of claims 1 to 9.

11. A heat dissipation member containing the urethane resin according to claim 10.

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