Silicone additive for resin modification and curable resin composition containing same

Abstract

The present invention provides a silicone additive for resin modification that contains a maleimide group-containing organopolysiloxane (I) represented by formula (1) (in the formula, R1 independently represent a C1-12 monovalent hydrocarbon group, the proportion of methyl groups among all R1 is 50 mol% or more, R2 independently represent a hydrogen atom or a C1-5 alkyl group, and n represents an integer of 4-20.) and a maleimide group-containing organopolysiloxane (II) represented by formula (2) (in the formula, R1, R2, and n are the same as above.) and is characterized in that the content of component (II) is 10-90 mol% relative to a total amount of 100 mol% of component (I) and component (II), and a curable resin composition containing the silicone additive for resin modification. The purpose of the present invention is to provide a silicone additive for resin modification which simultaneously imparts excellent flexibility, heat resistance, and dielectric properties, and to provide a curable resin composition using the same.

Description

Silicone additive for modifying resin and curable resin composition containing same

[0001] The present invention relates to a silicone additive for modifying resins and a curable resin composition containing the same.

[0002] In recent years, the integration and miniaturization of semiconductors, which are widely used in electronic devices, communication devices, personal computers, etc., have been accelerating. Accordingly, the properties required of laminates for semiconductor packages used in printed wiring boards are becoming increasingly strict. Examples of required properties include flexibility, heat resistance (glass transition temperature (Tg)), and dielectric properties.

[0003] The insulating layer of a printed wiring board typically uses a curable resin composition containing an epoxy resin, a phenoxy resin, a polyvinyl acetal resin, a maleimide resin, a polyphenylene ether resin, or the like (Patent Documents 1 to 4). However, these curable resins have the problem of internal stress accumulation due to a decrease in free volume during curing. Therefore, when a curable resin is used as an insulating material for a printed wiring board, cracks and warping may occur in the molded product due to cure shrinkage. Furthermore, the accumulation of internal strain may reduce the reliability of the printed wiring board. Therefore, there is a demand for a curable resin composition that reduces the accumulation of internal stress and the occurrence of cracks during curing. In this case, the balance of physical properties such as heat resistance and dielectric properties is also important.

[0004] For example, a curable resin composition has been reported in which a material having maleimide groups at both ends of a linear oligosiloxane is added to a bismaleimide-triazine resin (hereinafter abbreviated as BT resin) (Patent Documents 5 and 6). The aim is to achieve a balance between flexibility, heat resistance, and dielectric properties in the cured resin obtained by introducing silicone chains. However, because the silicone chains are short in length, the effect of imparting flexibility derived from silicone is insufficient, and there is still room for improvement in the balance of physical properties.

[0005] JP 2007-254709 A JP 2007-254710 A JP 2018-44065 A JP 2019-1965 A WO 2019 / 39135 WO 2019 / 230944

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a silicone additive for modifying resins that simultaneously imparts excellent flexibility, heat resistance, and dielectric properties, and a curable resin composition using the same.

[0007] As a result of intensive research conducted by the present inventors to solve the above-mentioned problems, they discovered that by using a silicone additive for resin modification containing a maleimide group-containing organopolysiloxane (I) represented by the following formula (1) and a maleimide group-containing organopolysiloxane (II) represented by the following formula (2), the resulting curable resin composition can be molded into a uniform sheet, and also achieves a high level of flexibility, heat resistance, and dielectric properties. This discovery led to the completion of the present invention.

[0008] That is, the present invention provides the following silicone additive for modifying resins and a curable resin composition containing the same: 1. A maleimide group-containing organopolysiloxane (I) represented by the following formula (1): (In the formula, R 1 each independently represents a monovalent hydrocarbon group having 1 to 12 carbon atoms, and all R 1 The proportion of methyl groups in R is 50 mol % or more, 2 each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and n represents an integer of 4 to 20. Maleimide group-containing organopolysiloxane (II) represented by the following formula (2) (In the formula, R 1 , R 2 1. A silicone additive for modifying resins, comprising: (a) a silicone compound having a hydroxyl group and a hydroxyl group; and (b) a silicone compound having a hydroxyl group and a hydroxyl group; and (c) a silicone compound having a hydroxyl group and a hydroxyl group; and (d) a silicone compound having a hydroxyl group and a hydroxyl group; and (e) a silicone compound having a hydroxyl group and a hydroxyl group; and (f) a silicone compound having a hydroxyl group and a hydroxyl group; and (g ... 1 3. The silicone additive for modifying resins according to the above item 1, wherein R is a methyl group. 2 4. The silicone additive for modifying resins according to the above item 1 or 2, wherein all of are hydrogen atoms. 4. (A) a maleimide group-containing organopolysiloxane (I) represented by the following formula (1), (In the formula, R 1 each independently represents a monovalent hydrocarbon group having 1 to 12 carbon atoms, and all R 1The proportion of methyl groups in R is 50 mol % or more, 2 each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and n represents an integer of 4 to 20. Maleimide group-containing organopolysiloxane (II) represented by the following formula (2) (In the formula, R 1 , R 2 , n is the same as above), wherein the content of the component (II) is 10 to 90 mol % relative to 100 mol % of the total amount of the components (I) and (II), (B) an aromatic cyanate ester compound having one or more cyanate groups in one molecule, and (C) a maleimide compound having two or more maleimide groups in one molecule and having no siloxane bond. 5. A curable resin composition comprising the R 1 6. The curable resin composition according to 4 above, wherein R is a methyl group. 2 are all hydrogen atoms. 7. The curable resin composition according to any one of the above 4 to 6, further comprising a curing catalyst (D). 8. The curable resin composition according to the above 4, wherein the content of the component (A) is 1 to 25 parts by mass per 100 parts by mass of the resin solid content in the resin composition.

[0009] By using a resin-modifying silicone additive comprising the maleimide group-containing organopolysiloxane of the present invention in a curable resin composition, it is possible to impart excellent flexibility, heat resistance, and dielectric properties to the curable resin composition.

[0010] The present invention will be described in detail below. The silicone additive for modifying resins according to the present invention comprises a maleimide group-containing organopolysiloxane represented by the following formula (1).

[0011] In the above formula (1), n ​​represents an integer of 4 to 20. For compatibility reasons, n is preferably 4 to 15, and more preferably 4 to 10. The above maleimide group-containing organopolysiloxane may be used as a single compound or as a mixture of compounds with different n values.

[0012] In the above formula (1), R 1 R independently represents a monovalent hydrocarbon group having 1 to 12 carbon atoms.1 Examples of the alkyl group include alkyl groups such as methyl, ethyl, propyl, butyl, isopropyl, isobutyl, t-butyl, pentyl, hexyl, heptyl, octyl, and 2-ethylhexyl; alkenyl groups such as vinyl, allyl, butenyl, pentenyl, and hexenyl; aryl groups such as phenyl, tolyl, xylyl, naphthyl, and biphenyl; and aralkyl groups such as benzyl and phenethyl. These hydrocarbon groups may also be hydrocarbon groups in which a portion or all of the hydrocarbon group is substituted with a halogen atom such as chlorine or fluorine. Among these, methyl, ethyl, phenyl, or benzyl is preferred, with methyl or phenyl being more preferred, and methyl being even more preferred.

[0013] Also, all R 1 The proportion of methyl groups must be 50 mol % or more, preferably 65 mol % or more, more preferably 70 mol % or more, and even more preferably 100 mol %, i.e., all methyl groups. In the present invention, when the above-mentioned maleimide group-containing organopolysiloxane is a mixture in which n is different, it is preferable that the proportion of methyl groups in all of the maleimide group-containing organopolysiloxanes contained in the mixture is within the above-mentioned range.

[0014] In the above formula (1), R 2 R independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 2 Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, etc. Among these, a hydrogen atom, a methyl group, or an ethyl group is preferred, a hydrogen atom or a methyl group is more preferred, and a hydrogen atom is even more preferred.

[0015] The maleimide group-containing organopolysiloxane can be produced, for example, by the following method, but is not particularly limited thereto. One production method involves mixing an acid anhydride compound and an organopolysiloxane containing primary amino groups at both ends in an organic solvent capable of dissolving these raw materials, followed by an imidization reaction. A catalyst or dehydrating agent may be used in the reaction process, as needed. The reaction is preferably carried out at a low temperature, provided that the desired reaction proceeds without impairing productivity.

[0016] The organic solvent is not particularly limited as long as it is a liquid organic compound that can sufficiently dissolve the raw materials without reacting with them. Examples include aprotic polar solvents such as dimethyl sulfone, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, and N-methylpyrrolidone; sulfones such as tetramethylene sulfone; ether-based solvents such as tetrahydrofuran, 4-methyltetrahydropyran, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether monoacetate, and cyclopentyl methyl ether; ketone-based solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone; and aromatic solvents such as toluene and xylene. Among these, ether-based solvents and aprotic polar solvents are preferred from the viewpoints of reactivity and solubility. The organic solvents can be used alone or in combination of two or more.

[0017] The catalyst is not particularly limited, but examples thereof include organic metal salts such as tin octoate, zinc octoate, dibutyltin dimaleate, zinc naphthenate, cobalt naphthenate, and tin oleate; metal chlorides such as zinc chloride, aluminum chloride, and tin chloride; and tertiary amine compounds. Among these, from the viewpoint of reactivity, cobalt naphthenate is preferred for thermal imidization without using a dehydrating agent, and a tertiary amine is preferred for chemical imidization in combination with a dehydrating agent, as described below. The catalyst can be used alone or in an appropriate mixture of two or more.

[0018] Chemical imidization using a dehydrating agent has the advantage of being able to lower the reaction temperature of the imidization reaction compared to thermal imidization. The dehydrating agent used is designed to react with the water generated, but not with the substrate in the reaction system. The chemical species generated by the reaction with water are not reactive with the resulting imide compound and can be removed in a subsequent process.

[0019] Examples of the dehydrating agent include carboxylic acid anhydrides, specifically acetic anhydride, propionic anhydride, succinic anhydride, maleic anhydride, etc., but are not limited thereto. When using a carboxylic acid anhydride, it is preferable to use a tertiary amine in an equimolar amount with the carboxylic acid anhydride. The tertiary amine is not particularly limited, but triethylamine is preferred from the viewpoints of market availability and ease of removal in a subsequent process.

[0020] The reaction ratio of the substrate is preferably 0.8 to 1.5 moles of acid anhydride for imidization per mole of primary amino group. If the amount of acid anhydride per mole of primary amino group is 0.8 moles or less or 1.5 moles or more, an excess of unreacted functional groups may remain, which may result in a decrease in the yield of the desired imide compound.

[0021] The amount of dehydrating agent used in chemical imidization is preferably 1 to 2 moles per mole of the primary amino group, and an equimolar amount of tertiary amine should also be used. From the viewpoint of productivity, the amount of tertiary amine used is preferably in the range of 1.2 to 1.6 moles.

[0022] In the method for producing the maleimide group-containing organopolysiloxane of formula (1) above, the reaction time for raw materials such as the primary amino group-containing organopolysiloxane and the acid anhydride compound is preferably 10 minutes to 24 hours. The reaction time may be any time that allows the raw materials to be sufficiently consumed as the reaction proceeds, but is preferably 1 to 10 hours, and more preferably 2 to 7 hours. If the reaction time is less than 10 minutes, raw materials may not be sufficiently consumed, while if the reaction time exceeds 24 hours, the raw materials may already be completely consumed, resulting in an unnecessary step and reduced production efficiency.

[0023] The maleimide group-containing organopolysiloxane represented by formula (1) produced by the above method can contain a by-product represented by the following formula (2): (In the formula, R 1 , R 2 , n is the same as above.

[0024] The silicone additive for resin modification of the present invention can impart excellent flexibility, heat resistance, and dielectric properties to a curable resin by adjusting the amount of the maleimide group-containing organopolysiloxane represented by formula (2) to fall within the range of 10 to 90 mol %, relative to 100 mol % of the total amount of the maleimide group-containing organopolysiloxane and the maleimide group-containing organopolysiloxane represented by formula (1).

[0025] That is, one of the features of the present invention is that the content of the maleimide group-containing organopolysiloxane of formula (2) is within the range of 10 to 90 mol %, preferably 20 to 90 mol %, relative to 100 mol % of the total amount of the maleimide group-containing organopolysiloxane (I) represented by formula (1) and the maleimide group-containing organopolysiloxane (II) represented by formula (2): In the production process, it is important to use the dehydrating agent and tertiary amine within the above-mentioned preferred ranges in terms of the amount used, in order to keep the amount of maleimide group-containing organopolysiloxane (II) produced within the range of 10 to 90 mol %.

[0026] The content of the maleimide group-containing organopolysiloxane represented by the formula (2) is determined under the following conditions: 1 The amount was determined by H-NMR analysis. [Measurement conditions] Apparatus: AVANCE III400 manufactured by BURKER Solvent: CDCl3 Internal standard: tetramethylsilane (TMS)

[0027] The weight-average molecular weight of the maleimide group-containing organopolysiloxane represented by formula (1) is not particularly limited, but in consideration of imparting sufficient flexibility to the cured product obtained by curing a curable composition containing this compound, the weight-average molecular weight is preferably 500 to 5,000, and more preferably 1,000 to 3,500. Note that the weight-average molecular weight in the present invention is a value determined by gel permeation chromatography (GPC) measured under the conditions shown below, converted using polystyrene of known molecular weight as the standard substance. [Measurement conditions] Developing solvent: tetrahydrofuran (THF) Flow rate: 0.6 mL / min Detector: differential refractive index detector (RI) Column: TSK Guard column Super H-H TSKgel Super HM-N (6.0 mm I.D. × 15 cm × 1) TSKgel Super H2500 (6.0 mm I.D. × 15 cm × 1) (all manufactured by Tosoh Corporation) Column temperature: 40°C Sample injection volume: 50 μL (THF solution with a concentration of 0.3% by mass)

[0028] The functional group equivalent of the polymerizable unsaturated group in the maleimide group-containing organopolysiloxane represented by formula (1) is not particularly limited. Considering the need to provide sufficient flexibility to the cured product of a curable composition containing this compound, a functional group equivalent of 200 to 900 g / mol is preferred. Values ​​lower than 200 g / mol may result in excessively high crosslink density during the crosslinking reaction of the polymerization moieties, potentially preventing the desired flexibility from being achieved. On the other hand, functional group equivalents higher than 900 g / mol may result in low crosslink density during the crosslinking reaction of the polymerization moieties, potentially preventing the development of sufficient hardness.

[0029] The curable resin composition of the present invention comprises: (A) a maleimide group-containing organopolysiloxane (I) represented by the following formula (1); (In the formula, R 1 each independently represents a monovalent hydrocarbon group having 1 to 12 carbon atoms, and all R 1 The proportion of methyl groups in R is 50 mol % or more, 2 each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and n represents an integer of 4 to 20. Maleimide group-containing organopolysiloxane (II) represented by the following formula (2) (In the formula, R 1 , R 2 , n is the same as above.) The silicone resin composition is characterized by containing: (B) an aromatic cyanate ester compound having one or more cyanato groups per molecule; and (C) a maleimide compound having two or more maleimide groups per molecule and no siloxane bond, wherein the content of the component (II) is 10 to 90 mol % relative to 100 mol % of the total amount of the components (I) and (II). The curable composition preferably contains (D) a curing catalyst.

[0030] The silicone resin component of component (A) is the same as the silicone additive for resin modification described above.

[0031] The aromatic cyanate ester compound of component (B) is characterized by having one or more cyanato groups (cyanate ester groups) per molecule. A curable resin composition using this aromatic cyanate ester compound exhibits excellent properties such as heat resistance and low thermal expansion when cured.

[0032] Specific examples of the aromatic cyanate ester compound of component (B) include cyanatobenzene, 1-cyanato-2-methylbenzene, 1-cyanato-3-methylbenzene, 1-cyanato-4-methylbenzene, 1-cyanato-2-methoxybenzene, 1-cyanato-3-methoxybenzene, 1-cyanato-4-methoxybenzene, 1-cyanato-2,3-dimethylbenzene, 1-cyanato-2,4-dimethylbenzene, 1-cyanato-2,5-dimethylbenzene, 1-cyanato-2,6-dimethylbenzene, 1-cyanato-3,4-dimethylbenzene, 1- Cyanato-3,5-dimethylbenzene, cyanatoethylbenzene, cyanatobutylbenzene, cyanatooctylbenzene, cyanatononylbenzene, 2-(4-cyanaphenyl)-2-phenylpropane (cyanate of 4-α-cumylphenol), 1-cyanato-4-cyclohexylbenzene, 1-cyanato-4-vinylbenzene, 1-cyanato-2- or 1-cyanato-3-chlorobenzene, 1-cyanato-2,6-dichlorobenzene, 1-cyanato-2-methyl-3-chlorobenzene, cyanatonitrobenzene, 1-cyanato-4-nitro-2 -ethylbenzene, 1-cyanato-2-methoxy-4-allylbenzene (eugenol cyanate), methyl (4-cyanatophenyl) sulfide, 1-cyanato-3-trifluoromethylbenzene, 4-cyanatobiphenyl, 1-cyanato-2-acetylbenzene, 1-cyanato-4-acetylbenzene, 4-cyanatobenzaldehyde, 4-cyanatobenzoic acid methyl ester, 4-cyanatobenzoic acid phenyl ester, 1-cyanato-4-acetaminobenzene, 4-cyanatobenzophenone, 1-cyanato-2,6-di-tert-butylbenzene benzene, 1,2-dicyanatobenzene, 1,3-dicyanatobenzene, 1,4-dicyanatobenzene, 1,4-dicyanato-2-tert-butylbenzene, 1,4-dicyanato-2,3-dimethylbenzene, 1,4-dicyanato-2,3,5-trimethylbenzene, 1,3-dicyanato-2,4,5-trimethylbenzene, 1,3-dicyanato-5-methylbenzene, 1-cyanatonaphthalene, 2-cyanatonaphthalene, 1-cyanato-4-methoxynaphthalene, 2-cyanato-6-methylnaphthalene, 2-cyanato-7-methoxynaphthalene, 2,2'-dicyanato-1,1'-binaphthyl, 1,3-, 1,4-, 1,5-, 1,6-, 1,7-, 2,3-, 2,6- or 2,7-dicyanatosinaphthalene, 2,2'-dicyanatobiphenyl, 4,4'-dicyanatobiphenyl, 4,4'-dicyanatooctafluorobiphenyl, 2,4'-dicyanatodiphenylmethane, 4,4'-dicyanatodiphenylmethane, bis(4-cyanato-3,5-dimethylphenyl)methane, 1,1-bis(4-cyanatophenyl)ethane, 1,1-bis(4-cyanatophenyl)propane, 2,2-bis(4-cyanatophenyl)ethane, 1,1-bis(4-cyanatophenyl)propane, 1,1-bis(4-cyanatophenyl)propane, 2,2-bis(4-cyanato-3-methylphenyl)propane, 2,2-bis(2-cyanato-5-biphenylyl)propane, 2,2-bis(4-cyanatophenyl)hexafluoropropane, 2,2-bis(4-cyanato-3,5-dimethylphenyl)propane, 1,1-bis(4-cyanatophenyl)butane, 1,1-bis(4-cyanatophenyl)isobutane, 1,1-bis(4-cyanatophenyl)pentane, 1,1-bis(4-cyanatophenyl)-3-methylbutane, 1,1-bis(4-cyanatophenyl)-2- Methylbutane, 1,1-bis(4-cyanatophenyl)-2,2-dimethylpropane, 2,2-bis(4-cyanatophenyl)butane, 2,2-bis(4-cyanatophenyl)pentane, 2,2-bis(4-cyanatophenyl)hexane, 2,2-bis(4-cyanatophenyl)-3-methylbutane, 2,2-bis(4-cyanatophenyl)-4-methylpentane, 2,2-bis(4-cyanatophenyl)-3,3-dimethylbutane, 3,3-bis(4-cyanatophenyl)hexane, 3,3-bis(4-cyanatophenyl)heptane, 3,3-bis(4 -cyanatophenyl)octane, 3,3-bis(4-cyanatophenyl)-2-methylpentane, 3,3-bis(4-cyanatophenyl)-2-methylhexane, 3,3-bis(4-cyanatophenyl)-2,2-dimethylpentane, 4,4-bis(4-cyanatophenyl)-3-methylheptane, 3,3-bis(4-cyanatophenyl)-2-methylheptane, 3,3-bis(4-cyanatophenyl)-2,2-dimethylhexane, 3,3-bis(4-cyanatophenyl)-2,4-dimethylhexane, 3,3-bis(4-cyanatophenyl)-2,2,4-trimethylpentane, 2,2-bis(4-cyanatophenyl)-1,1,1,3,3,3-hexafluoropropane, bis(4-cyanatophenyl)phenylmethane, 1,1-bis(4-cyanatophenyl)-1-phenylethane, bis(4-cyanatophenyl)biphenylmethane, 1,1-bis(4-cyanatophenyl)cyclopentane, 1,1-bis(4-cyanatophenyl)cyclohexane, 2,2-bis(4-cyanato-3-isopropylphenyl)propane, 1,1-bis(3-cyclohexyl-4-cyanatophenyl)cyclohexane , bis(4-cyanatophenyl)diphenylmethane, bis(4-cyanatophenyl)-2,2-dichloroethylene, 1,3-bis[2-(4-cyanatophenyl)-2-propyl]benzene, 1,4-bis[2-(4-cyanatophenyl)-2-propyl]benzene, 1,1-bis(4-cyanatophenyl)-3,3,5-trimethylcyclohexane, 4-[bis(4-cyanatophenyl)methyl]biphenyl, 4,4-dicyanatobenzophenone, 1,3-bis(4-cyanatophenyl)-2-propen-1-one, bis(4-cyanatophenyl)e ether, bis(4-cyanatophenyl) sulfide, bis(4-cyanatophenyl) sulfone, 4-cyanatobenzoic acid-4-cyanatophenyl ester (4-cyanatophenyl-4-cyanatobenzoate), bis-(4-cyanatophenyl) carbonate, 1,3-bis(4-cyanatophenyl)adamantane, 1,3-bis(4-cyanatophenyl)-5,7-dimethyladamantane, 3,3-bis(4-cyanatophenyl)isobenzofuran-1(3H)-one (cyanate of phenolphthalein), 3,3-bis(4-cyanato-3-methyl) phenyl)isobenzofuran-1(3H)-one (cyanate of o-cresolphthalein), 9,9'-bis(4-cyanatophenyl)fluorene, 9,9'-bis(4-cyanato-3-methylphenyl)fluorene, 9,9'-bis(2-cyanato-5-biphenylyl)fluorene, tris(4-cyanatophenyl)methane, 1,1,1-tris(4-cyanatophenyl)ethane, 1,1,3-tris(4-cyanatophenyl)propane, α,α,α'-tris(4-cyanatophenyl)-1-ethyl-4-isopropylbenzene, 1,1,2,2-tetrakis(4-cyanatophenyl)ethane, tetrakis(4-cyanatophenyl)methane, 2,4,6-tris(N-methyl-4-cyanatoanilino)-1,3,5-triazine, 2,4-bis(N-methyl-4-cyanatoanilino)-6-(N-methylanilino)-1,3,5-triazine, bis(N-4-cyanato-2-methylphenyl)-4,4'-oxydiphthalimide, bis(N-3-cyanato-4-methylphenyl)-4,4'-oxydiphthalimide, bis(N-4-cyanatophenyl)-4,4'-oxydiphthalimide, bis(N-4-cyanato-2-methylphenyl) tris(3,5-dimethyl-4-cyanatobenzyl)isocyanurate, 2-phenyl-3,3-bis(4-cyanatophenyl)phthalimidine, 2-(4-methylphenyl)-3,3-bis(4-cyanatophenyl)phthalimidine, 2-phenyl-3,3-bis(4-cyanato-3-methylphenyl)phthalimidine, 1-methyl-3,3-bis(4-cyanatophenyl)indolin-2-one, and 2-phenyl-3,3-bis(4-cyanatophenyl)indolin-2-one.

[0033] The maleimide compound (C) is characterized by having two or more maleimide groups in one molecule and having no siloxane bond. Examples of this maleimide compound include compounds having two or more maleimide groups in one molecule that are commonly distributed as bismaleimide resins. Examples include co-condensation products of bismaleimide and aldehyde compounds, and one or more of these can be used. Examples of the bismaleimide include aliphatic maleimides such as N,N'-ethylene bismaleimide and N,N'-hexamethylene bismaleimide, 4,4'-diphenylmethane bismaleimide, N,N'-m-phenylene bismaleimide, N,N'-p-phenylene bismaleimide, 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, bis[4-(4-maleimidophenoxy)phenyl]methane, and 1,1,1,3,3,3-hexafluoro-2,2-bis[4-(4-maleimidophenoxy)phenyl]propane. Examples of the aldehyde compound include aromatic maleimides such as N,N'-p,p'-diphenyldimethylsilyl bismaleimide, N,N'-4,4'-diphenylether bismaleimide, N,N'-methylenebis(3-chloro-p-phenylene)bismaleimide, N,N'-4,4'-diphenylsulfone bismaleimide, N,N'-4,4'-dicyclohexylmethane bismaleimide, N,N'-dimethylenecyclohexane bismaleimide, N,N'-m-xylene bismaleimide, and N,N'-4,4'-diphenylcyclohexane bismaleimide. Examples of the aldehyde compound include formaldehyde, acetaldehyde, benzaldehyde, and hydroxyphenylaldehyde.

[0034] The curable composition may contain a curing catalyst (D) as needed. Examples of the curing catalyst for component (D) include imidazole compounds such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 2-phenylimidazole, and 1-benzyl-2-methylimidazole; tertiary amine compounds such as triethylamine, benzyldimethylamine, α-methylbenzyldimethylamine, and 1,8-diazabicyclo[5.4.0]undecene-7; triphenylphosphine, tributylphosphine, tri(p-methylphenyl)phosphine, tri(nonylphenyl)phosphine, triphenylphosphine-triphenylborate, and tetraphenylphosphine-tetraphenylphosphine. Examples of suitable organic phosphorus compounds include organophosphonium compounds such as triphenylphosphine, tributylhexadecylphosphonium bromide, and tris(dimethoxyphenyl)phosphine; phosphonium salts obtained by reacting organophosphonium compounds such as triphenylphosphine, tributylphosphine, tri(p-methylphenyl)phosphine, tri(nonylphenyl)phosphine, and tris(dimethoxyphenyl)phosphine with hydrogen halides or alkyl halides; organometallic compounds such as aluminum and zirconium; as well as heterocyclic amine compounds, boron complex compounds, organic ammonium salts, organic sulfonium salts, and organic peroxides, and one or more of these may be used. Among these, tetraphenylphosphonium tetra-p-tolylborate is preferred from the viewpoint of further accelerating curing.

[0035] The content of the silicone resin component, component (A), can be appropriately set depending on the desired properties and is not particularly limited. From the viewpoint of further improving the balance of physical properties of flexibility, heat resistance, and dielectric properties, the content is preferably 1 to 25 parts by mass, more preferably 2 to 20 parts by mass, and even more preferably 5 to 15 parts by mass, per 100 parts by mass of the resin solid content in the resin composition.

[0036] The content of the aromatic cyanate ester compound as component (B) can be appropriately set depending on the desired properties and is not particularly limited. From the viewpoint of further improving the balance of physical properties including flexibility, heat resistance, and dielectric properties, the content is preferably 1 to 99 parts by mass, more preferably 10 to 80 parts by mass, and even more preferably 25 to 70 parts by mass per 100 parts by mass of the resin solid content in the resin composition.

[0037] The content of the maleimide compound, component (C), can be appropriately set depending on the desired properties and is not particularly limited. However, from the viewpoint of further improving the balance of physical properties including flexibility, heat resistance, and dielectric properties, the content is preferably 1 to 99 parts by mass, more preferably 10 to 80 parts by mass, and even more preferably 25 to 70 parts by mass, per 100 parts by mass of the resin solids in the resin composition. In the present invention, "resin solids" refers to the components (A), (B), and (C). Therefore, the amount of resin solids in the resin composition is the total amount of the components (A), (B), and (C).

[0038] The content of the curing catalyst as the component (D) is not particularly limited as long as the desired curing rate, cured physical properties, and appropriate pot life of the composition are satisfied, but it is generally preferable that the content be 0.1 to 5 parts by mass per 100 parts by mass of the resin solid content in the resin composition.

[0039] The curable resin composition of the present invention may contain an organic solvent as needed. In this case, the composition may be used in a form (solution or varnish) in which at least a part, preferably all, of the various resin components described above are dissolved or compatible with the organic solvent. The organic solvent used may be used alone or in a suitable mixture of two or more kinds.

[0040] As the organic solvent, known organic solvents can be appropriately used, and the type thereof is not particularly limited. Specific examples of the organic solvent include ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; cellosolve-based solvents such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate; ester-based solvents such as methyl lactate, methyl acetate, ethyl acetate, butyl acetate, isoamyl acetate, ethyl lactate, methyl methoxypropionate, and methyl hydroxyisobutyrate; polar solvents such as amides such as N-methylpyrrolidinone, dimethylacetamide, and dimethylformamide; and non-polar solvents such as aromatic hydrocarbons such as toluene and xylene. Among these, N-methylpyrrolidinone is preferred from the viewpoint of dissolving power, and methyl ethyl ketone is preferred from the viewpoint of balance with drying property.

[0041] The curable resin composition of the present invention can be appropriately prepared according to a conventional method, and the preparation method is not particularly limited as long as it is a method that can obtain a curable composition that uniformly contains the (A) silicone resin component, the (B) aromatic cyanate ester compound, the (C) maleimide compound, and the other components. For example, the curable composition of the present invention can be easily prepared by sequentially blending the (A), (B), and (C) components and the other components in an organic solvent and thoroughly stirring the mixture.

[0042] The set temperature for heat-curing the curable resin composition of the present invention is not particularly limited as long as the desired physical properties of the cured product can be exhibited, but from the viewpoint of the volatility of the organic solvent and production efficiency, it is preferably 100 to 250° C., more preferably 150 to 200° C. The curing time can be set appropriately.

[0043] The method for producing a self-supporting cured molded product using the curable resin composition of the present invention is not particularly limited, and any known production method can be used, including, but not limited to, a method using a mold, and a film-forming method using a casting method in which the composition is applied to a film previously provided with a release layer and cured.

[0044] In the method for producing the above-mentioned self-supporting cured molded article, when a molding matrix is ​​used, the material of the molding matrix is ​​not particularly limited as long as it ensures releasability from the cured product obtained after curing. Examples include metal, glass, plastic, silicone, etc. In addition, the surface of the matrix may be coated with a resin such as polytetrafluoroethylene (PTFE) or ethylene-tetrafluoroethylene (ETFE), and among these, a mold surface-coated with PTFE is preferred because it has excellent releasability. Such a mold can prevent damage to the cured product when the curable resin composition of the present invention is removed.

[0045] Cured products of the curable resin composition of the present invention can be used, in particular, as encapsulants for electronic components, prepregs, metal foil-clad laminates, printed wiring boards, and semiconductor packages. For example, a prepreg can be obtained by impregnating or applying a varnish of the curable composition of the present invention to a substrate and drying it. Furthermore, a build-up film or dry film solder resist can be obtained by using a peelable plastic film as the substrate and applying the varnish to the plastic film and drying it. The organic solvent used can be dried at a temperature of 20 to 150°C for 1 to 90 minutes. Furthermore, the curable resin composition of the present invention can be used in an uncured state, after the organic solvent has been dried, or in a semi-cured (B-staged) state as needed.

[0046] The present invention will be described in more detail below with reference to synthesis examples, examples, and comparative examples, but the present invention is not limited to these examples. In the following examples, unless otherwise specified, "parts" and "%" mean "parts by mass" and "% by mass," respectively. The devices used in the examples are as follows:

[0047] (1) GPC Measurement Conditions Apparatus: HLC-8320GPC manufactured by Tosoh Corporation Developing solvent: tetrahydrofuran (THF) Flow rate: 0.6 mL / min Detector: differential refractive index detector (RI) Column: TSK Guard column Super H-H TSKgel Super HM-N (6.0 mm I.D. × 15 cm × 1) TSKgel Super H2500 (6.0 mm I.D. × 15 cm × 1) (all manufactured by Tosoh Corporation) Column temperature: 40°C Sample injection volume: 50 μL (THF solution with a concentration of 0.3% by mass) Standard: monodisperse polystyrene (2) Proton nuclear magnetic resonance spectrum ( 1 H-NMR) Measurement conditions: Apparatus: BURKER AVANCE III 400 Solvent: CDCl3 Internal standard: tetramethylsilane (TMS)

[0048] [1] Synthesis of Maleimide Group-Containing Organopolysiloxane [Synthesis Example 1] 98.1 parts by mass (1 mole) of maleic anhydride, 300 parts by mass of tetrahydrofuran, and 0.4 parts by mass of bis-t-butylphenol (a polymerization inhibitor) were placed in a 1-L separable flask equipped with a stirrer, reflux condenser, dropping funnel, and thermometer, and mixed with stirring. After uniform dissolution of the components, 270 parts by mass (1 mole of amino groups) of polydimethylsiloxane (A1) having a primary amino functional group content of 270 g / mol and an aminopropyldimethylsilyl structure at both ends was added dropwise. The dropping reaction generated heat, and a water bath was used to control the temperature of the reaction solution so that it did not exceed 50°C. After completion of the dropping, stirring was continued at room temperature for 1 hour, and the disappearance of the reaction raw materials was confirmed by GPC. Subsequently, 150 parts by mass (1.5 moles) of acetic anhydride was added and stirred, followed by the dropwise addition of 150 parts by mass (1.5 moles) of triethylamine. A slight exotherm occurred during the dropwise addition, and the appearance changed from orange to deep red. After the dropwise addition was completed, the reaction was continued for 3 hours at an internal temperature of 50°C. GPC confirmed the disappearance of the peak derived from the amic acid structural component formed in the intermediate stage, and a new peak corresponding to the maleimide group-containing organopolysiloxane. Finally, the unreacted acid anhydride, amine, and tetrahydrofuran were distilled off under reduced pressure to obtain a black oily compound (M1). The viscosity of this compound at 25°C was 400 mPa·s. The obtained organopolysiloxane was analyzed by GPC and 1The results of H-NMR confirmed that the product was a mixture of structures represented by the following formula (1-a) and formula (2-a). The content of formula (2-a) was 86 mol% of the total components.

[0049]

[0050] [Synthesis Example 2] The polydimethylsiloxane (A1) having an aminopropyldimethylsilyl structure at both ends used in Synthesis Example 1 was replaced with polydimethylsiloxane (A2) having an aminopropyldimethylsilyl structure at both ends with a primary amino functional group amount of 430 g / mol, and the reaction ratio was adjusted, but the same procedure as in Synthesis Example 1 was carried out to obtain a black oily compound (M2). The viscosity of this compound at 25°C was 160 mPa s. The obtained siloxane was analyzed by GPC and 1 The results of H-NMR confirmed that the product was a mixture of structures represented by the following formula (1-b) and formula (2-b). The content of formula (2-b) was 50 mol % of the total components.

[0051]

[0052] [Synthesis Example 3] The polydimethylsiloxane (A1) having an aminopropyldimethylsilyl structure at both ends used in Synthesis Example 1 was replaced with a polydimethylsiloxane (A3) having an aminopropyldimethylsilyl structure at both ends with a primary amino functional group amount of 780 g / mol, and the same procedure was carried out except for adjusting the reaction ratio, to obtain a black oily compound (M3). The viscosity of this compound at 25°C was 130 mPa s. The obtained siloxane was analyzed by GPC and 1 The results of H-NMR confirmed that the product was a mixture of structures represented by the following formula (1-c) and formula (2-c). The content of formula (2-c) was 22 mol% of the total components.

[0053]

[0054] [2] Preparation of curable composition for molding self-supporting sheets [Examples 1 to 3, Comparative Examples 1 to 5] The components were mixed in the compounding ratios shown in Table 1 below to prepare the thermosetting compositions of Examples 1 to 3 and Comparative Examples 1 to 5. The ratios are expressed as mass ratios. The compositions were designed so that the molar ratio of maleimide groups to cyanate groups was 1:3, and the molar ratio of maleimide groups to curing catalyst was 1:0.03. The compositions were dissolved and diluted with N-methylpyrrolidinone to make a varnish with a final active ingredient content of 35%.

[0055]

[0056] The abbreviations in Table 1 are as follows: "MR-0": Disiloxane having two maleimide groups represented by the following formula (manufactured by Shin-Etsu Chemical Co., Ltd.); "BMI-70": Aromatic compound having two maleimide groups represented by the following formula (manufactured by K.I. Kasei Co., Ltd., trade name "BMI-70"); "LECY": Bisphenol E compound having two cyanate groups represented by the following formula (manufactured by Lonza Japan, trade name "LECy"); "Curing catalyst": Tetraphenylphosphonium tetraphenylborate (manufactured by Hokko Chemical Industry Co., Ltd., trade name "TPP-K")

[0057]

[0058] The thermosetting composition in Table 1 was poured into a mold (depth 0.3 mm × length 15 cm × width 10 cm) whose surface was coated with polytetrafluoroethylene (PTFE) resin, and the mold was then placed on a hot plate heated to 200° C. to volatilize the organic solvent (N-methylpyrrolidinone) for 90 minutes at 200° C. Thereafter, the mold was heated in a dryer at 150° C. for 60 minutes, and then further heated in a dryer at 200° C. for 60 minutes to complete curing, thereby obtaining a sheet test piece.

[0059] The sheet molded products obtained in Examples 1 to 3 and Comparative Examples 1 to 5 above were evaluated as follows. The results are shown in Table 2. (1) Moldability When removed from the mold, the product was observed to see if it could stand on its own, and the evaluation was made as follows: ∘: It could be removed as a sheet without any abnormalities. ×: It was brittle or soft and could not be removed as a sheet. (2) 90° Bending Property To evaluate flexibility, the 90° bending property was evaluated. The test pieces obtained above were cut into strips 1 cm wide, cut into strips 10 cm long, 1 cm wide, and 0.3 mm thick, and both short sides were picked up with tweezers and bent at 90°. The state of the sheet was observed and the evaluation was made as follows: ∘: It could be bent without breaking. ×: It broke completely and could not be bent. (3) Appearance Change at 150°C The test pieces obtained above were cut into rectangular shapes measuring 3 cm in length, 4 cm in width, and 0.3 mm in thickness, and the changes in the appearance of the sheets after heating at 150°C for 1 hour were observed and rated as follows: ∘: Almost no change in appearance, and no warping was observed. ×: Obvious changes in appearance, such as warping, were observed. (4) Durometer Hardness Measured in accordance with JIS K7215 using a TECLOCK hardness tester type D indenter. (5) Storage Modulus, Tanδ (max) The test pieces obtained above were cut into strips measuring 10 cm in length, 1 cm in width, and 0.3 mm in thickness, and measured in tensile measurement mode using a viscoelasticity measuring device DMA7100 manufactured by Hitachi High-Tech Science Corporation, while heating from -50°C to 300°C at a heating rate of 10°C / min in an air atmosphere. (6) Dielectric Constant and Dielectric Loss Tangent The test piece obtained above was cut into a rectangular shape of 3 cm in length × 4 cm in width × 0.3 mm in thickness, and a network analyzer (manufactured by Keysight Corporation, "E5063-2D5") and a strip line (manufactured by Keycom Corporation) were connected to measure the dielectric constant and dielectric loss tangent at a frequency of 10 GHz.

[0060]

[0061] From the results in Table 2, it can be seen that the sheet moldings of Examples 1 to 3 achieve high levels of processability, flexibility, hardness (durometer, storage modulus), heat resistance, and low dielectric properties.

[0062] On the other hand, the composition of Comparative Example 1 did not contain the silicone resin component (maleimide group-containing organopolysiloxane (I)) (A), and therefore the flexibility of the obtained test piece was insufficient. The composition of Comparative Example 2 contained a maleimide group-containing organopolysiloxane as the silicone resin component, but the siloxane structure was disiloxane, which did not contribute to the expected improvement in flexibility, and as a result, the flexibility remained at the same level as that of Comparative Example 1. The compositions of Comparative Examples 3 to 5 were molded products consisting only of the silicone resin component (maleimide group-containing organopolysiloxane (I)) (A) and the cyanate ester compound (B), but in Comparative Examples 4 and 5, a significant decrease in hardness prevented the production of a uniform sheet molded product. In Comparative Example 3, a sheet molded product was also obtained, but deterioration in hardness and dielectric loss tangent was observed.

[0063] As shown in Table 2, the curable resin composition using the additive comprising the maleimide group-containing organopolysiloxane of the present invention combines flexibility, heat resistance, and dielectric properties, and can be suitably used as a sealing material for electronic components, prepreg, metal foil-clad laminate, printed wiring board, and a constituent material for semiconductor packages, etc.

[0064] The present invention is not limited to the above-described embodiments, which are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits similar effects is included within the technical scope of the present invention.

Claims

1. A maleimide group-containing organopolysiloxane (I) represented by the following formula (1): (In the formula, R 1 each independently represents a monovalent hydrocarbon group having 1 to 12 carbon atoms, and all R 1 The proportion of methyl groups in R is 50 mol % or more, 2 each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and n represents an integer of 4 to 20. Maleimide group-containing organopolysiloxane (II) represented by the following formula (2) (In the formula, R 1 , R 2 , n is the same as above), and the content of component (II) is 10 to 90 mol % relative to 100 mol % of the total amount of components (I) and (II).

2. The above R 1 2. The silicone additive for modifying resins according to claim 1, wherein all of are methyl groups.

3. The above R 2 3. The silicone additive for modifying resins according to claim 1 or 2, wherein all of are hydrogen atoms.

4. (A) a maleimide group-containing organopolysiloxane (I) represented by the following formula (1); (In the formula, R 1 each independently represents a monovalent hydrocarbon group having 1 to 12 carbon atoms, and all R 1 The proportion of methyl groups in R is 50 mol % or more, 2 each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and n represents an integer of 4 to 20. Maleimide group-containing organopolysiloxane (II) represented by the following formula (2) (In the formula, R 1 , R 2 , n is the same as above), wherein the content of component (II) is 10 to 90 mol % relative to 100 mol % of the total amount of components (I) and (II), (B) an aromatic cyanate ester compound having one or more cyanato groups per molecule, and (C) a maleimide compound having two or more maleimide groups per molecule and having no siloxane bond.

5. The above R 1 The curable resin composition according to claim 4, wherein all of are methyl groups.

6. The above R 2 The curable resin composition according to claim 4, wherein all of are hydrogen atoms.

7. The curable resin composition according to any one of claims 4 to 6, further comprising a curing catalyst (D).

8. The curable resin composition according to claim 4, wherein the content of component (A) is 1 to 25 parts by mass per 100 parts by mass of the resin solid content in the resin composition.

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