Curable composition, cured product, and heat-dissipating member

Abstract

The present invention pertains to a curable composition which contains a polyether polyol, a polyisocyanate, a compound having a phosphate group, and a filler, and in which the content of the compound having a phosphate group is 0.03-0.9 parts by weight with respect to 100 parts by weight of the filler.

Description

Curable composition, cured product, and heat dissipation member

[0001] The present invention relates to a curable composition, a cured product of the curable composition, and a heat dissipation member containing the cured product.

[0002] Electronic devices are becoming increasingly integrated and faster every year, and the demand for heat-dissipating materials to combat this is increasing. Insufficient heat dissipation can hinder the normal operation of electronic devices, potentially causing deterioration, malfunction, or damage. A polyurethane resin composition containing a hydroxyl group-containing compound including polybutadiene polyol, a specific polyisocyanate compound, and an inorganic filler is known as a material that exhibits heat dissipation properties (Patent Document 1).

[0003] JP 2017-101195 A

[0004] However, fillers such as inorganic fillers tend to aggregate, which poses a problem of poor dispersibility in curable compositions, which are mixtures of monomers and fillers. Therefore, dispersants have been used to prevent filler aggregation and uniformly disperse the filler. However, the use of dispersants poses a problem of reduced strength of the cured product. Furthermore, dispersants also pose a problem of inhibiting the urethanization reaction (curing).

[0005] An object of the present invention is to provide a curable composition that has excellent dispersibility of a filler and suppresses inhibition of the urethanization reaction by a dispersant, and that has excellent strength (particularly tensile strength) when cured.

[0006] The present inventors conducted extensive research to solve the above-mentioned problems and discovered that by using a compound having a phosphate group as a dispersant and adjusting the content of the compound having a phosphate group within a specific range relative to the content of the filler, a curable composition can be obtained in which the dispersant exhibits excellent filler dispersibility and inhibits the inhibition of the urethanization reaction, and the cured product exhibits excellent strength. This finding led to the present invention. Specifically, the present invention relates to a curable composition comprising a polyether polyol, a polyisocyanate, a compound having a phosphate group, and a filler, wherein the content of the compound having a phosphate group is 0.03 to 0.9 parts by weight relative to 100 parts by weight of the filler, a cured product of the curable composition, and a heat dissipation member comprising the cured product.

[0007] According to the present invention, it is possible to provide a curable resin composition that has excellent dispersibility of a filler and suppresses inhibition of the urethanization reaction by a dispersant, and that has excellent strength (particularly tensile strength) when cured.

[0008] The curable composition of the present invention comprises a polyether polyol, a polyisocyanate, a compound having a phosphate group, and a filler, and the content of the compound having a phosphate group is 0.03 to 0.9 parts by weight per 100 parts by weight of the filler. The curable composition of the present invention is also a polyurethane resin-forming composition.

[0009] The curable composition of the present invention contains a polyether polyol as an essential component, and therefore has low viscosity and good handleability. As the polyether polyol, a polyoxyalkylene polyol having an alkylene group is preferred from the viewpoint of reducing the viscosity of the curable composition. Preferred examples of polyoxyalkylene polyols include polyethylene glycol, polypropylene glycol, polyoxyethylene-oxypropylene glycol, polytetramethylene glycol, polyoxytetramethylene-oxyethylene glycol, polytetraoxytramethylene-oxypropylene glycol, polyhexamethylene ether glycol, and polyoxypropylene glyceryl ether. Polyoxyalkylene polyols are commercially available as Sannix PK-400 (manufactured by Sanyo Chemical Industries, Ltd.), for example. One type of polyether polyol may be used alone, or two or more types may be used in combination.

[0010] The polyether polyol is preferably a polyoxyalkylene diol from the viewpoint of flexibility of the resulting curable composition.

[0011] From the viewpoint of reducing viscosity, the number average molecular weight (Mn) of the polyether polyol is preferably 100 to 10,000, more preferably 150 to 3,000, and most preferably 200 to 2,000. The conditions for measuring the Mn of the polyether polyol are as follows: Apparatus: High-temperature gel permeation chromatograph ["Alliance GPC V2000", manufactured by Nihon Waters K.K.] Detector: Refractive index detector Solvent: Orthodichlorobenzene Reference material: Polystyrene Sample concentration: 3 mg / ml Column stationary phase: Two PLgel 10 μm, MIXED-B columns in series [manufactured by Polymer Laboratories] Column temperature: 135°C

[0012] In the curable composition of the present invention, the content ratio of the polyether polyol is not particularly limited. For example, when a polyoxyalkylene polyol is used as the polyether polyol, the content is preferably 3 to 20 wt %, and more preferably 5 to 10 wt %, based on the total weight of the curable composition.

[0013] The curable composition of the present invention may contain a polyol other than the above-mentioned polyether polyol. Examples of the polyol other than the polyether polyol include polyester polyol, polycarbonate polyol, and polyolefin polyol. The polyol other than the polyether polyol may be used alone or in combination of two or more.

[0014] Examples of polyester polyols include condensates of polyols [such as the above-mentioned polyether polyols, aliphatic diols, trivalent or higher aliphatic polyols, alicyclic polyols, and alkylene oxide (ethylene oxide, propylene oxide, 1,2-, 1,3-, 2,3-, or 1,4-butylene oxide, etc., hereinafter sometimes abbreviated as AO) adducts of alicyclic polyols] with polycarboxylic acids, and these polyester polyols are commercially available as Kuraray Polyol P-2010 [manufactured by Kuraray Co., Ltd.], etc.

[0015] The aliphatic diol may be an aliphatic diol having 2 to 20 carbon atoms. The aliphatic diol preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms.

[0016] Examples of the trivalent or higher aliphatic polyol include trivalent or higher aliphatic polyols having 3 to 20 carbon atoms (such as glycerin and pentaerythritol), and preferably glycerin.

[0017] Examples of the alicyclic polyol include alicyclic polyols having 4 to 16 carbon atoms (1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.).

[0018] The AO adduct of the alicyclic polyol may be a compound obtained by adding an AO to the alicyclic polyol. The AO may be the same as those exemplified in the description of the polyester polyol, and the preferred AOs are also the same.

[0019] Examples of polycarboxylic acids include linear 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, benzo ... canedioic acid, octadecanedioic acid, nonadecanedioic acid, and eicosanedioic acid; 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, etc.]; and aromatic polycarboxylic acids having 8 to 20 carbon atoms [terephthalic acid, isophthalic acid, 2-methylterephthalic acid, 4,4-stilbene dicarboxylic acid, naphthalenedicarboxylic acid, 4,4-biphenyldicarboxylic acid, orthophthalic acid, and diphenyl ether dicarboxylic acid, etc.].

[0020] Examples of polycarbonate polyols include reaction products of polyols [such as the above-mentioned polyether polyols, aliphatic diols, tri- or higher hydric aliphatic polyols, alicyclic polyols, and AO adducts of alicyclic polyols] with phosgene, and these are commercially available as Kuraray Polyol C-590, Kuraray Polyol C-2090 [both manufactured by Kuraray Co., Ltd.], etc.

[0021] Examples of polyolefin polyols include polybutadiene polyols and hydrogenated polybutadiene diols.

[0022] From the viewpoint of the tensile strength of the cured product, the polyol preferably has at least two hydroxyl groups per molecule on average.

[0023] When the curable composition of the present invention contains a polyether polyol and a polyol other than the polyether polyol, the content of the polyol other than the polyether polyol is preferably 100 to 150 parts by weight based on 100 parts by weight of the polyether polyol.

[0024] The curable composition of the present invention contains a polyisocyanate. Examples of the polyisocyanate include a chain aliphatic polyisocyanate, an alicyclic polyisocyanate, an aromatic polyisocyanate, a dimer of these polyisocyanates, and an isocyanurate of these polyisocyanates. One type of polyisocyanate may be used alone, or two or more types may be used in combination.

[0025] Examples of the chain aliphatic polyisocyanate include chain aliphatic polyisocyanates having 4 to 20 carbon atoms, and preferred examples include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate.

[0026] Examples of the alicyclic polyisocyanate include alicyclic polyisocyanates having 6 to 17 carbon atoms, and preferred examples 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. Alicyclic polyisocyanates are commercially available as Desmodur I (manufactured by Sumika Covestro Urethane Co., Ltd.), etc.

[0027] Examples of aromatic polyisocyanates include aromatic polyisocyanates having 8 to 22 carbon atoms, and preferred examples 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).

[0028] Examples of the polyisocyanate dimer include dimers of polyisocyanates (such as the aforementioned chain aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates). Polyisocyanate dimers are commercially available as Duranate A201H (manufactured by Asahi Kasei Corporation).

[0029] Examples of the isocyanurate of polyisocyanate include trimers of polyisocyanates (such as the aforementioned chain aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates). Isocyanurate of polyisocyanate is commercially available as Duranate TLA-100 (manufactured by Asahi Kasei Corporation), etc.

[0030] Among polyisocyanates, from the viewpoint of excellent moldability, chain aliphatic polyisocyanates, alicyclic polyisocyanates, dimers of chain aliphatic polyisocyanates, dimers of alicyclic polyisocyanates, isocyanurates of chain aliphatic polyisocyanates, and isocyanurates of alicyclic polyisocyanates are preferred. One type of polyisocyanate may be used alone, or two or more types may be used in combination.

[0031] In the curable composition of the present invention, the content of the polyisocyanate is not particularly limited. For example, when an isocyanurate (trimer) of hexamethylene diisocyanate or a dimer of hexamethylene diisocyanate is used as the polyisocyanate, the content is preferably 4 to 20 wt %, and more preferably 5 to 10 wt %, based on the total weight of the curable composition.

[0032] The total content of the polyol and polyisocyanate in the curable composition of the present invention is not particularly limited and can be adjusted appropriately depending on the compounds used, but is preferably 3 to 30 wt %, more preferably 3 to 20 wt %, based on the total weight of the curable composition. In particular, when a polyoxyalkylene polyol is used as the polyether polyol and an isocyanurate (trimer) of hexamethylene diisocyanate or a dimer of hexamethylene diisocyanate is used as the polyisocyanate, the total content is preferably 7 to 30 wt %, more preferably 10 to 20 wt %, based on the total weight of the curable composition.

[0033] In the curable composition of the present invention, the molar ratio of isocyanate groups in the polyisocyanate to hydroxyl groups in the polyether polyol (total number of moles of isocyanate groups in the polyisocyanate / total number of moles of hydroxyl groups in the polyether polyol) (hereinafter also simply referred to as the isocyanate index) is preferably 0.8 to 1.2. When the isocyanate index is in this range, the curability of the curable composition and the flexibility of the cured product are good.

[0034] The curable composition of the present invention contains a compound having a phosphate group, and the content of the compound having a phosphate group is within a specific range relative to the content of the filler, so that the dispersibility of the filler is excellent, there is no aggregation of the filler in the curable composition, and the curable composition becomes uniform. Furthermore, the inhibition of the urethanization reaction by the dispersant is suppressed, and the strength of the cured product is excellent.

[0035] Preferred examples of the compound having a phosphate group include phosphate esters. The compound having a phosphate group may be used alone or in combination of two or more. More preferred examples of the phosphate ester include phosphate esters represented by the following general formula (1):

[0036]

[0037] [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; A １ O is an alkyleneoxy group having 2 to 3 carbon atoms, and n1 is A １ represents the average number of moles of O added, and is a number from 0 to 15; 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, and A ２ O is an alkyleneoxy group having 2 to 3 carbon atoms, and n2 is A ２ represents the average number of moles of O added, and is a number from 0 to 15.

[0038] In general formula (1), R １is a hydrogen atom, an alkyl group having 2 to 18 carbon atoms, or an alkenyl group having 2 to 18 carbon atoms. Some of the hydrogen atoms of the alkyl group having 2 to 18 carbon atoms or the alkenyl group having 2 to 18 carbon atoms may be substituted with halogen atoms. Examples of the alkyl group having 2 to 18 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, each of which may be linear or branched. Examples of alkenyl groups having 2 to 18 carbon atoms include ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, and octadecenyl groups, each of which may be linear or branched, and the position of the double bond is not limited. As the halogen atom, a fluorine atom is preferred. R １ The alkyl group may be linear or branched, but is preferably linear. From the viewpoints of the strength of the cured product of the curable composition and the dispersibility of the filler, the alkyl group is preferably an alkyl group having 12 to 18 carbon atoms.

[0039] In general formula (1), A １ O represents an alkyleneoxy group having 2 to 3 carbon atoms, and examples thereof include an ethyleneoxy group and a propyleneoxy group. Among these, an ethyleneoxy group is preferred from the viewpoint of dispersibility of the filler. n1 represents A １ It represents the average number of moles of O added, and is a number from 0 to 15, preferably 0 to 13, more preferably 4 to 11, from the viewpoint of good dispersibility of the filler and strength of the cured product.

[0040] 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, and A ２O is an alkyleneoxy group having 2 to 3 carbon atoms, and n2 is A ２ represents the average number of moles of O added, and is a number from 0 to 15. ３ As for R １ The same can be mentioned as above, and the preferred examples are also the same. ２ As for O, A １ The same examples as those for O can be mentioned, and the preferred examples are also the same. The preferred range of n2 is the same as that for n1. ２ is a hydrogen atom, the compound of general formula (1) is a phosphoric acid monoester, and R ２ But-(A ２ O) ｎ２ R ３ When R ２ But-(A ２ O) ｎ２ R ３ In the case of １ and R ３ may be the same or different, and n1 and n2 may be the same or different.

[0041] As the phosphate ester represented by the general formula (1), R １ Two or more different types may be used in combination, or a phosphate monoester (R ２ is a hydrogen atom) and phosphate diester (R ２ But-(A ２ O) ｎ２ R ３ A mixture of a monophosphate ester and a diphosphate ester (mono-dimixture) may also be used. The phosphate ester represented by general formula (1) is generally obtained as a mixture of a monophosphate ester and a diphosphate ester (mono-dimixture). Salts of the phosphate ester represented by general formula (1) (metal salts such as sodium salt, potassium salt, and magnesium salt, ammonium salt, etc.) may also be used.

[0042] Preferred examples of the phosphate ester represented by general formula (1) include alkyl ether phosphate esters, alkenyl ether phosphate esters, alkenyl ether alkyl ether phosphate esters, alkyl phosphate esters, alkenyl phosphate esters, fluorinated alkyl ether phosphate esters, and fluorinated alkyl phosphate esters, with alkyl ether phosphate esters being more preferred. The phosphate ester represented by general formula (1) can be obtained by phosphorylation using a polyether and phosphorus oxide. Examples of the phosphate ester represented by general formula (1) include Disparlon DA-375 (manufactured by Kusumoto Chemicals Co., Ltd.), Plysurf A208N (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), Phosphanol RL-210 (manufactured by Toho Chemical Industry Co., Ltd.), and the like. 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., (C12-15) Pareth-9 phosphate, R １ , R ３ : C12-15 alkyl group, A １ O.A. ２ O: ethyleneoxy group, n1, n2: 9, mono- and di-mixture], Phosphanol RS-410 [manufactured by Toho Chemical Industry Co., Ltd., (C12-15) Pareth-3 phosphate, R １ , R ３ : C12-15 alkyl group, A １ O.A. ２ O: ethyleneoxy group, n1, n2: 3, mono-di-mixture], Phosphanol RB-410 [manufactured by Toho Chemical Industry Co., Ltd., oleth-4 phosphate, R １ , R ３ : C18 alkenyl group, A １ O.A. ２ O: ethyleneoxy group, n1, n2: 4, mono-di-mixture], Phosphanol RL-310 [manufactured by Toho Chemical Industry Co., Ltd., steareth-3 phosphate, R １ , R ３ : C18 alkyl group, A １ O.A. ２O: ethyleneoxy group, n1, n2: 3, mono- and di-mixture], JP-518-O [manufactured by Johoku Chemical Industry Co., Ltd., oleyl acid phosphate, n1, n2: 0, mono- and di-mixture], JP-506H [manufactured by Johoku Chemical Industry Co., Ltd., butoxyethyl acid phosphate, n1, n2: 1, mono- and di-mixture], etc.

[0043] In the curable composition of the present invention, the content of the compound having a phosphate group is 0.03 to 0.9 parts by weight, preferably 0.03 to 0.8 parts by weight, and more preferably 0.03 to 0.6 parts by weight, relative to 100 parts by weight of the filler. When the content of the compound having a phosphate group is 0.03 parts by weight or more relative to 100 parts by weight of the filler, the dispersibility of the filler is excellent, there is no aggregation of the filler in the curable composition, and a uniform curable composition is obtained. When the content is 0.9 parts by weight or less, inhibition of the urethanization reaction by the dispersant is suppressed, the curability at room temperature is good, and the strength of the cured product is excellent.

[0044] The curable composition of the present invention contains a filler. As the filler, a thermally conductive filler (such as boron nitride, aluminum nitride, aluminum oxide, silica, magnesium oxide, and aluminum hydroxide) is preferred. By using these fillers, the cured product of the curable composition can be made into a cured product suitable for heat dissipation components. The fillers may be used alone or in combination of two or more.

[0045] As the filler in the curable composition of the present invention, fillers other than the thermally conductive filler described above can be used, and by changing the type of filler, cured products with various functions can be obtained depending on the type of filler. For example, by including carbon or a metal as the filler, a highly conductive cured product can be obtained, by including a metal oxide and / or a metal hydroxide, a highly insulating cured product can be obtained, by including polyimide or polyethylene, a low-dielectric cured product can be obtained, by including barium titanate and / or lead titanium zirconate, a highly flame-retardant cured product can be obtained, by including ammonium polyphosphate and / or a halide, a highly light-blocking cured product can be obtained by including titanium black, a highly refractive cured product can be obtained by including titanium oxide and / or zirconium oxide, a highly strong cured product can be obtained by including glass fiber, carbon fiber, and Kevlar® fiber, a highly antibacterial cured product can be obtained by including silver salt, copper salt, and zinc salt, and a highly lightweight cured product can be obtained by including microballoons.

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

[0047] When the filler is in the form of spherical particles, the volume average particle diameter [D50: particle diameter at which the cumulative particle amount in the particle size distribution on a volume basis becomes 50%] of the filler is preferably 0.01 to 200 μm, more preferably 0.1 to 150 μm, from the viewpoint of excellent moldability, etc. 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, a solution of the composition may be measured.

[0048] The content of the filler in the curable composition of the present invention is preferably 70 to 97 wt %, more preferably 80 to 97 wt %, and most preferably 80 to 90 wt %, based on the total weight of the curable composition. When the content of the filler is 70 wt % or more, the physical properties (e.g., thermal conductivity) of the cured product of the curable composition become better. Furthermore, when the content of the filler is 97 wt % or less, the moldability becomes good.

[0049] The curable composition of the present invention may contain other components in addition to the polyether polyol, polyisocyanate, compound having a phosphate group, and filler, such as polyols other than the polyether polyols described above, urethane catalysts, antioxidants, dehydrating agents, colorants, surfactants, plasticizers, solvents, and ultraviolet absorbers.

[0050] 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.]. The urethanization catalyst is commercially available as a bismuth catalyst [Neostan U-600, manufactured by Nitto Kasei Co., Ltd.], etc.

[0051] When the curable composition of the present invention contains a urethanization catalyst, the content of the urethanization catalyst is preferably 10 parts by weight or less, more preferably 0.01 to 8 parts by weight, and particularly preferably 0.3 to 8 parts by weight, per 100 parts by weight of the total content of the polyether polyol and the polyisocyanate.

[0052] Examples of the antioxidant include hindered phenol-based antioxidants [Irganox 1135, Irganox 1010, and Irganox 1076 (all manufactured by BASF Japan Ltd.)] and hindered amine-based antioxidants [Sanol LS770 and Sanol LS-744 (all manufactured by Sankyo Co., Ltd.)].

[0053] When the curable composition of the present invention contains an antioxidant, the content of the antioxidant is preferably 0.5 to 10.0 parts by weight, more preferably 2.0 to 8.0 parts by weight, and particularly preferably 4.0 to 6.0 parts by weight, per 100 parts by weight of the total of the polyether polyol and the polyisocyanate in the curable composition.

[0054] Examples of the dehydrating agent include zeolite, etc. When the curable composition of the present invention contains a dehydrating agent, the content of the dehydrating agent is preferably 1 to 10 wt %, more preferably 2 to 7 wt %, and particularly preferably 3 to 5 wt %, based on the total weight of the curable composition.

[0055] As the surfactant, polyoxyalkylene type nonionic surfactants, ester type nonionic surfactants, anionic surfactants and cationic surfactants can be preferably used.

[0056] Examples of polyoxyalkylene type nonionic surfactants include AO adducts (preferably with an average number of moles added 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 polyoxyalkylene type nonionic surfactants include n-, i-, sec- or t-butanol, octanol, and dodecanol. Preferred alkylphenols include phenol, methylphenol, and nonylphenol. Preferred aliphatic amines include laurylamine and methylstearylamine. Preferred aliphatic amides include stearic acid amide.

[0057] Examples of the ester-type nonionic surfactant include ester compounds of fatty acids having 4 to 30 carbon atoms (such as lauric acid, stearic acid, and oleic acid) with polyhydric alcohols other than sucrose, sorbitol, and glycerin.

[0058] Examples of anionic surfactants include carboxylate, sulfate, and sulfonate types. Examples of carboxylate types include alkali metal salts of the above-mentioned fatty acids having 4 to 30 carbon atoms and alkali metal salts of polyoxyalkylene alkyl ether carboxylic acids. Examples of sulfate types include alkali metal sulfate esters of the above-mentioned aliphatic alcohols having 4 to 30 carbon atoms or AO adducts of aliphatic alcohols. Examples of sulfonate types include alkali metal sulfonates of alkylphenols. Anionic surfactants are commercially available as polyether carboxylic acids [Kao Akipo RLM-100, manufactured by Kao Corporation], etc.

[0059] Examples of cationic surfactants include primary to tertiary amine salt types and quaternary ammonium salt types. Examples of 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)], and inorganic acid (such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid) salts of triethanolamine and monoesters of fatty acids having 4 to 30 carbon atoms. Examples of quaternary ammonium salt types include inorganic acid salts of quaternary ammonium having 4 to 30 carbon atoms (such as butyltrimethylammonium, diethyllaurylmethylammonium, and dimethyldistearylammonium). Cationic surfactants are commercially available, such as Nopcosperse 092 [manufactured by San Nopco Ltd., cationic surfactant].

[0060] When the curable composition of the present invention contains a surfactant, the content of the surfactant is preferably 0.001 to 30 wt %, more preferably 0.01 to 10 wt %, and particularly preferably 0.1 to 5 wt %, based on the total weight of the curable composition.

[0061] Examples of the plasticizer include phthalic acid plasticizers [diisononyl phthalate, di-(2-ethylhexyl) phthalate, diisodecyl phthalate, butyl benzyl phthalate, etc.], fatty acid ester plasticizers [di-(2-ethylhexyl) adipate, di-n-decyl adipate, di-(2-ethylhexyl) azelate, dibutyl sebacate, di-(2-ethylhexyl) sebacate, etc.], benzoic acid plasticizers [polyethylene glycol benzoate ester], epoxy plasticizers such as epoxidized soybean oil, trimellitate plasticizers, pyromellitate plasticizers, polyester plasticizers, and sulfonate ester plasticizers. The plasticizer is commercially available as diisononyl phthalate (DINP, manufactured by Aekyung Petrochemical Co., Ltd.) or polyethylene glycol benzoate (EB-300, manufactured by Sanyo Chemical Industries, Ltd.).

[0062] When the curable composition of the present invention contains a plasticizer, the content of the plasticizer is preferably 1 to 100 parts by weight, more preferably 1 to 70 parts by weight, per 100 parts by weight of the total content of components other than the plasticizer contained in the curable composition.

[0063] Examples of the ultraviolet absorber include triazole-based ultraviolet absorbers (e.g., Tinuvin 320 (manufactured by BASF Japan)) and benzophenone-based ultraviolet absorbers (e.g., Cyasorb UV9 (manufactured by Cyanamid)).

[0064] The curable composition of the present invention is preferably a two-part curable composition comprising a first part and a second part, which are cured by mixing the first part and the second part in a specific mixing ratio.

[0065] When the curable composition of the present invention is a two-component curable composition, it is preferable that the first agent contains a polyether polyol, a compound having a phosphate group, and a filler, and the second agent contains a polyisocyanate, a compound having a phosphate group, and a filler.

[0066] The content of the polyether polyol in the first agent is preferably 1 to 20 wt %, more preferably 5 to 15 wt %, based on the weight of the first agent. When the content of the polyether polyol in the first agent is 1 wt % or more, the strength of the cured product is good, and when it is 20 wt % or less, the handleability of the curable composition is good.

[0067] The content of the polyisocyanate in the second agent is preferably 1 to 20% by weight, more preferably 10 to 18% 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 strength of the cured product is good, and when it is 20% by weight or less, the handleability of the curable composition is good.

[0068] The content of the compound having a phosphate group in the first agent is preferably 0.03 to 0.9 parts by weight, more preferably 0.05 to 0.8 parts by weight, and even more preferably 0.1 to 0.7 parts by weight, relative to 100 parts by weight of the filler in the first agent. When the content of the compound having a phosphate group in the first agent is 0.03 parts by weight or more relative to 100 parts by weight of the filler in the first agent, the dispersibility of the filler is excellent, there is no aggregation of the filler in the first agent, and a uniform first agent is obtained. When the content is 0.9 parts by weight or less, when the compound having a phosphate group is mixed with the second agent to form a curable composition, inhibition of the urethanization reaction by the dispersant is suppressed, the curability at room temperature is good, and the strength of the cured product is excellent.

[0069] The content of the compound having a phosphate group in the second agent is preferably 0.03 to 0.9 parts by weight, more preferably 0.03 to 0.8 parts by weight, and even more preferably 0.05 to 0.7 parts by weight, relative to 100 parts by weight of the filler in the second agent. When the content of the compound having a phosphate group in the second agent is 0.03 parts by weight or more relative to 100 parts by weight of the filler in the second agent, the dispersibility of the filler is excellent, there is no aggregation of the filler in the second agent, and a uniform second agent is obtained. When the content is 0.9 parts by weight or less, when the compound having a phosphate group is mixed with the first agent to form a curable composition, inhibition of the urethanization reaction by the dispersant is suppressed, the curability at room temperature is good, and the tensile strength of the cured product is excellent.

[0070] The content of the filler in the first agent is preferably 75 to 95 wt %, and more preferably 80 to 90 wt %, based on the weight of the first agent. When the content of the filler in the first agent is 75 wt % or more, the physical properties (e.g., thermal conductivity) of the cured product of the curable composition are good, and when it is 95 wt % or less, the handleability of the curable composition is good.

[0071] The content of the filler in the second agent is preferably 75 to 95 wt %, and more preferably 75 to 85 wt %, based on the weight of the second agent. When the content of the filler in the second agent is 75 wt % or more, the physical properties (e.g., thermal conductivity) of the cured product of the curable composition are good, and when it is 95 wt % or less, the handleability of the curable composition is good.

[0072] The first agent is obtained by uniformly mixing the polyether polyol, the compound having a phosphate group, the filler, and other components (polyols other than polyether polyols, surfactants, plasticizers, urethanization catalysts, antioxidants, dehydrating agents, etc.) using a known mixing device (e.g., a mixing tank equipped with a stirrer). The components may be mixed all at once, or any two or more components may be mixed in advance and then the remaining components (which may be a mixture) may be mixed.

[0073] The second agent is obtained by uniformly mixing the polyisocyanate, the compound having a phosphate group, the filler, and other components (surfactant, plasticizer, urethanization catalyst, dehydrating agent, etc.) that are used as needed using a known mixer (e.g., a mixing tank equipped with a stirrer). The components may be mixed all at once, or any two or more components may be mixed in advance and then the remaining components (which may be a mixture) may be mixed.

[0074] The thixotropy index of the first agent at 23°C is preferably 1 to 10, and more preferably 2 to 7. When the thixotropy index of the first agent at 23°C is 1 or more, the dispersibility of the filler in the first agent is good and aggregation of the filler is suppressed, and when it is 10 or less, the handleability of the first agent is good. The thixotropy index of the first agent can be controlled by the content of the compound having a phosphate group and the filler in the first agent.

[0075] The thixotropy index of the second agent at 23°C is preferably 1 to 10, and more preferably 2 to 7. When the second agent has a thixotropy index of 1 or more at 23°C, the dispersibility of the filler in the second agent is good and aggregation of the filler is suppressed, and when it is 10 or less, the handleability of the second agent is good. The thixotropy index of the second agent can be controlled by the content of the compound having a phosphate group and the content of the filler in the second agent.

[0076] In this specification, thixotropy refers to a property in which the viscosity is relatively high in a steady state (e.g., when no shear stress is applied), the viscosity decreases when shear stress is applied, and the viscosity returns to its original value when the shear stress is no longer applied. In this specification, thixotropy can be expressed by the thixotropy index (TI), which is calculated using the viscosity measured with a rheometer "MCR302" (manufactured by Anton Paar Japan Co., Ltd.) according to the following formula (2): TI = (viscosity at a liquid temperature of 23°C at a shear rate of 1 / s) / (viscosity at a liquid temperature of 23°C at a shear rate of 10 / s) (2) The closer the thixotropy index is to 1, the more the liquid behaves like a Newtonian liquid, and the larger the thixotropy index, the higher the thixotropy.

[0077] When the curable composition of the present invention is a two-component curable composition, the first and second components are mixed and subjected to a urethane reaction on any substrate or in a mold having a shape appropriate for the purpose by a known method, thereby obtaining a cured product. The first and second components may be mixed manually or using a known mixing device (such as a container equipped with a stirrer), or may be mixed continuously using a known two-component mixing and supplying device.

[0078] The curable composition of the present invention has good handleability and excellent filler dispersibility. Furthermore, by using a thermally conductive filler as the filler, a cured product with high thermal conductivity suitable for heat dissipation components and the like can be obtained. Furthermore, since cured products with various functions can be obtained depending on the type of filler, the composition is useful for fuel cell separators, lithium-ion battery materials, power device TIMs, LED heat dissipation materials, smartphone housings, high-frequency amplifier components, and low-dielectric-constant / low-dielectric-tangent materials for 5G and 6G electric and electronic devices.

[0079] The cured product of the present invention is a cured product of the curable composition of the present invention. The cured product of the present invention can be obtained by curing the curable composition of the present invention by a known method. Since the cured product of the present invention is a cured product of the curable composition of the present invention, it has excellent strength and is preferably used as a heat dissipation member.

[0080] This specification describes the following. <1> A curable composition comprising a polyether polyol, a polyisocyanate, a compound having a phosphoric acid group, and a filler, wherein the content of the compound having a phosphoric acid group is 0.03 to 0.9 parts by weight per 100 parts by weight of the filler. <2> The curable composition according to <1>, wherein the polyether polyol is a polyoxyalkylene polyol. <3> The curable composition according to <1> or <2>, wherein the polyether polyol is a polyoxyalkylene diol. <4> The curable composition according to any one of <1> to <3>, wherein the compound having a phosphoric acid group is a phosphoric acid ester. <5> The curable composition according to any one of <1> to <4>, wherein the compound having a phosphoric acid group is a phosphoric acid ester represented by the following general formula (1):

[0081]

[0082] [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; A １ O is an alkyleneoxy group having 2 to 3 carbon atoms, and n1 is A １ represents the average number of moles of O added, and is a number from 0 to 15; 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, and A ２ O is an alkyleneoxy group having 2 to 3 carbon atoms, and n2 is A ２ (wherein 0 represents the average number of moles of O added and is a number from 0 to 15).] <6> The curable composition according to any one of <1> to <5> above, which is a two-component curable composition comprising a first part and a second part, wherein the first part contains a polyether polyol, a compound having a phosphate group, and a filler, and the second part contains a polyisocyanate, a compound having a phosphate group, and a filler. <7> The curable composition according to any one of <1> to <6> above, wherein the molar ratio of isocyanate groups in the polyisocyanate to hydroxyl groups in the polyether polyol (total number of moles of isocyanate groups in the polyisocyanate / total number of moles of hydroxyl groups in the polyether polyol) is 0.8 to 1.2. <8> A cured product of the curable composition according to any one of <1> to <7> above. <9> A heat dissipation member comprising the cured product according to <8> above.

[0083] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0084] Examples 1 to 5 and Comparative Examples 1 to 3 The components shown in the curable composition column in Table 1 below were mixed in the amounts (parts by weight) shown in Table 1 to prepare the first and second parts of the curable compositions. In Examples 1 to 5 and Comparative Example 1, the viscosity (unit: Pa s) of each of the first and second parts was measured using a rheometer "MCR302" (manufactured by Anton Paar Japan Ltd.) at shear rates of 0.1 / s, 1 / s, and 10 / s. The measurement temperature was a liquid temperature of 23°C, and the measurement jig used was PP50 processed into a lattice pattern. The thixotropy index (TI) was obtained by dividing the viscosity at a shear rate of 1 / s by the viscosity at a shear rate of 10 / s. On the other hand, in Comparative Example 2, which did not contain a compound having a phosphate group, and Comparative Example 3, in which the content of the compound having a phosphate group was less than 0.03 parts by weight per 100 parts by weight of filler, the dispersibility of the filler could not be sufficiently ensured, and the first and second parts could not be uniformly mixed, making it impossible to measure viscosity and calculate TI. Next, the first and second parts were mixed for 60 seconds at 2000 rpm using a planetary centrifugal mixer "Awatori Rentaro ARV-310P" (manufactured by Thinky Corporation), to obtain the curable compositions of Examples 1 to 5 and Comparative Examples 1 to 3. While homogeneous curable compositions were obtained in Examples 1 to 5 and Comparative Example 1, homogeneous curable compositions were not obtained in Comparative Examples 2 and 3. The curable compositions were poured into a molding die (1 cm long x 1 cm wide x 0.2 cm deep) to fill it, pressed with a press, and allowed to stand at 40°C for 24 hours to allow reaction. Sheet-like cured products were obtained with the curable compositions of Examples 1 to 5 and Comparative Example 1. The obtained cured products were evaluated for thermal conductivity, tensile strength, and cure rate by the following methods. The results are shown in Table 1. On the other hand, the curable compositions of Comparative Examples 2 and 3 could not be molded into a sheet, and no cured products could be obtained. Therefore, it was not possible to measure the thermal conductivity, tensile strength, and cure rate.

[0085] The compositions of the raw materials listed by trade name in Table 1 are as follows: PK-400: Polyoxyalkylene polyol (manufactured by Sanyo Chemical Industries, Ltd., trade name: Sannix PK-400, number average molecular weight: 200, number of hydroxyl groups: 2), TLA-100: Isocyanurate (trimer) of hexamethylene diisocyanate (manufactured by Asahi Kasei Corporation, trade name: Duranate TLA-100), A201H: Dimer of hexamethylene diisocyanate (manufactured by Asahi Kasei Corporation, trade name: Duranate A201H), RS-710: Polyoxyethylene alkyl (12-15) ether phosphate (manufactured by Toho Chemical Industry Co., Ltd., trade name: Phosphanol RS-710), JP-518-O: Oleyl acid phosphate (manufactured by Johoku Chemical Industry Co., Ltd., trade name: JP-518-O), JP-506H: butoxyethyl acid phosphate (manufactured by Johoku Chemical Industry Co., Ltd., trade name: JP-506H), SB-93: aluminum hydroxide (manufactured by Nippon Light Metal Co., Ltd., volume average particle size: 100 μm), CW-310LV: aluminum hydroxide (manufactured by Sumitomo Chemical Co., Ltd., volume average particle size: 10 μm), C-301N: aluminum hydroxide (manufactured by Sumitomo Chemical Co., Ltd., volume average particle size: 1.5 μm), U-600: bismuth catalyst (manufactured by Nitto Kasei Co., Ltd., trade name: Neostan U-600), Irganox 1135: hindered phenol-based antioxidant (manufactured by BASF Japan Ltd.), DIC Blue: blue colorant (manufactured by DIC Corporation), KAL3AB: zeolite (manufactured by Union Showa Co., Ltd.)

[0086] <Thermal Conductivity> The cured products obtained in Examples 1 to 5 and Comparative Example 1 were allowed to stand at 25°C for 2 hours, and then the thermal conductivity (unit: W / m K) of the cured products 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 properties (thermal conductivity).

[0087] <Tensile Strength> The tensile strength (unit: MPa) of the cured products obtained in Examples 1 to 5 and Comparative Example 1 was measured in accordance with JIS K7161-2 (2014).

[0088] <Cure Ratio> The cure ratio (unit: %) when the curable compositions of Examples 1 to 5 and Comparative Example 1 were cured was calculated using the following formula (3): Cure Ratio (%) = (C Hardness before curing × 100) / C Hardness after curing (3) In formula (3), the "C hardness before curing" refers to the C hardness at 25°C measured by mixing the first and second parts until homogeneous, molding them into a sheet having a thickness of 2 mm, leaving them to stand in an incubator at 25°C for 24 hours, stacking the sheets to a thickness of 10 mm or more, and measuring the C hardness using an Asker Rubber Hardness Tester Type C (manufactured by Kobunshi Keiki Co., Ltd.). In formula (3), the "C hardness after curing" refers to the C hardness at 40°C measured by leaving the sheets after measuring the C hardness before curing at 40°C for 24 hours, stacking the sheets to a thickness of 10 mm or more, and measuring the C hardness using an Asker Rubber Hardness Tester Type C (manufactured by Kobunshi Keiki Co., Ltd.). A higher value of the curing rate indicates a higher reaction rate of the urethane-forming reaction, and a low curing rate is considered to be due to the influence of the dispersant contained in the curable composition inhibiting the urethane-forming reaction.

[0089]

[0090] The cured products obtained in Examples 1 to 5 had higher tensile strength and better cure rates than the cured product obtained in Comparative Example 1. These results demonstrate that the curable compositions of the present invention have excellent filler dispersibility, inhibit inhibition of the urethanization reaction by the dispersant, and provide excellent strength when cured.

Claims

1. A curable composition comprising: a polyether polyol; a polyisocyanate; a compound having a phosphoric acid group; and a filler, wherein the content of the compound having a phosphoric acid group is 0.03 to 0.9 parts by weight per 100 parts by weight of the filler.

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

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

4. The curable composition according to claim 1 or 2, wherein the compound having a phosphoric acid group is a phosphoric acid ester.

5. The curable composition according to claim 1 or 2, wherein the compound having a phosphate group is a phosphate ester represented by the following general formula (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; A １ O is an alkyleneoxy group having 2 to 3 carbon atoms, and n1 is A １ represents the average number of moles of O added, which is a number from 0 to 15; 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 A ２ represents the average number of moles of O added, and is a number from 0 to 15.

6. The curable composition according to claim 1 or 2, which is a two-part type curable composition comprising a first part and a second part, the first part containing a polyether polyol, a compound having a phosphoric acid group, and a filler, and the second part containing a polyisocyanate, a compound having a phosphoric acid group, and a filler.

7. The curable composition according to claim 1 or 2, wherein the molar ratio of isocyanate groups in the polyisocyanate to hydroxyl groups in the polyether polyol (total number of moles of isocyanate groups in the polyisocyanate / total number of moles of hydroxyl groups in the polyether polyol) is 0.8 to 1.

2.

8. A cured product of the curable composition according to claim 1 or 2.

9. A heat dissipation member comprising the cured product according to claim 8.

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