Silicone additive for resin modification and curable resin composition containing the same

Abstract

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.SOLUTION: A curable resin composition comprises a maleimide group-containing organopolysiloxane represented by formula (1) and a maleimide group-containing organopolysiloxane represented by formula (2).SELECTED DRAWING: None

Description

[Technical Field]

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

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

[0003] For the insulating layer of a printed wiring board, 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 is usually used (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 causes less internal stress accumulation and less cracking 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 referred to 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. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-254709 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-254710 [Patent Document 3] JP 2018-44065 A [Patent Document 4] JP 2019-1965 A [Patent Document 5] International Publication No. 2019 / 39135 [Patent Document 6] International Publication No. 2019 / 230944 Summary of the Invention [Problem to be solved by the invention]

[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. [Means for solving the problem]

[0007] As a result of extensive research conducted by the present inventors to solve the above-mentioned problems, they discovered that by using a silicone additive for modifying resins 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): [ka] (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): [ka] (In the formula, R 1 , R 2 , n is the same as above.) and wherein 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 1 above, wherein is a methyl group. 3. The above R 2 3. The silicone additive for modifying resins according to the above 1 or 2, wherein all of are hydrogen atoms. 4. (A) a maleimide group-containing organopolysiloxane (I) represented by the following formula (1), [ka] (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): [ka] (In the formula, R 1 , R 2 , n is the same as above.) a silicone resin component containing the component (II) in an amount of 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 cyanato groups in one molecule, and (C) A maleimide compound having two or more maleimide groups in one molecule and no siloxane bond. A curable resin composition comprising: 5. The above R 1 5. The curable resin composition according to 4 above, wherein is a methyl group. 6. The above R 2 5. The curable resin composition according to 4 above, wherein all of are 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 4 above, 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. [Effects of the Invention]

[0009] By using the silicone additive for resin modification 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. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be specifically described below. The silicone additive for modifying resin according to the present invention contains a maleimide group-containing organopolysiloxane represented by the following formula (1). [ka]

[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 be partially or entirely substituted with halogen atoms such as chlorine and fluorine. Among these, methyl, ethyl, phenyl, and benzyl are preferred, with methyl and 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 of maleimide group-containing organopolysiloxanes having different n's, 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 solvents such as tetrahydrofuran, 4-methyltetrahydropyran, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether monoacetate, and cyclopentyl methyl ether; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone; and aromatic solvents such as toluene and xylene. Among these, ether solvents and aprotic polar solvents are preferred in terms of reactivity and solubility. The organic solvents can be used alone or in combination.

[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 with a dehydrating agent, as described below. The catalyst can be used alone or in a suitable 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), 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 long enough for 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): [ka] (In the formula, R 1 , R 2 , n is the same as above.) The maleimide group-containing organopolysiloxane includes a maleimide group-containing organopolysiloxane represented by the formula:

[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 Quantitative analysis was performed using H-NMR. [Measurement conditions] Equipment: BURKER AVANCE III400 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, 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: 0.6mL / min Detector: Refractive index detector (RI) Column: TSK Guardcolumn SuperH-H TSKgel SuperHM-N(6.0mmI.D.×15cm×1) TSKgel SuperH2500(6.0mmI.D.×15cm×1) (All manufactured by Tosoh Corporation) Column temperature: 40℃ Sample injection volume: 50 μL (0.3% by mass THF solution)

[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. If the functional group equivalent is less than 200 g / mol, the crosslinking density may be too high when the crosslinking reaction of the polymerized moieties is carried out, potentially preventing the desired flexibility from being achieved. On the other hand, if the functional group equivalent is greater than 900 g / mol, the crosslinking density may be too low when the crosslinking reaction of the polymerized moieties is carried out, 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): [ka] (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): [ka] (In the formula, R 1 , R 2 , n is the same as above.) a silicone resin component containing the component (II) in an amount of 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 cyanato groups in one molecule, and (C) A maleimide compound having two or more maleimide groups in one molecule and no siloxane bond. 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-4-methylbenzene, 1-cyanato-5-methylbenzene, 1-cyanato-6-methylbenzene, 1-cyanato-7-methylbenzene, 1-cyanato-8-methylbenzene, 1-cyanato-9-methylbenzene, 1-cyanato-10-methylbenzene, 1-cyanato-11-methylbenzene, 1-cyanato-12-methylbenzene, 1-cyanato-13-methylbenzene, 1-cyanato-14-methylbenzene, 1-cyanato-15-methylbenzene, 1-cyanato-16-methylbenzene, 1-cyanato-17-methylbenzene, 1-cyanato-18-methylbenzene, 1-cyanato-19 ... 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 Benzene, 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, 1,2-di Cyanatobenzene, 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)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-cyanato phenyl)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)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-methylphenyl) α,α,α'-tris(4-cyanatophenyl)-1-ethyl-4-isopropylbenzene, 1,1,2,3-tris(4-cyanatophenyl)-1-methyl-4-isopropylbenzene, 1,1,2,3-tris(4-cyanatophenyl)-1-methyl-4-isopropylbenzene, 1,1,2,3-tris(4-cyanatophenyl)-1-ethyl ...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)-4,4'-oxydiphthalimide 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 no siloxane bond. Examples of this maleimide compound include compounds having two or more maleimide groups in one molecule, which are commonly distributed as bismaleimide resins. For example, a co-condensation product of a bismaleimide and an aldehyde compound can be used alone or in combination. 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 optionally contain a curing catalyst (D). Examples of the curing catalyst (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; and heterocyclic amine compounds, boron complex compounds, organic ammonium salts, organic sulfonium salts, and organic peroxides. One or more of these compounds 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 (A) 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 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, 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. 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. In the present invention, the term "resin solid content" refers to the components (A), (B), and (C). Therefore, the amount of resin solid content in the resin composition is the total amount of the components (A), (B), and (C).

[0038] The content of the curing catalyst, component (D), is not particularly limited as long as the desired curing rate, cured physical properties, and appropriate usable 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 one type alone or two or more types may be appropriately mixed.

[0040] As the organic solvent, known ones can be appropriately used, and the type 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 properties.

[0041] The curable resin composition of the present invention can be prepared appropriately 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] When a molding matrix is ​​used in the method for producing the self-supporting cured molded article, 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, and silicone. The surface of the matrix may also be coated with a resin such as polytetrafluoroethylene (PTFE) or ethylene-tetrafluoroethylene (ETFE). Among these, a mold surface-coated with PTFE is preferred because of its excellent releasability. Such a mold can prevent damage to the cured product when the curable resin composition of the present invention is removed.

[0045] The cured product of the curable resin composition of the present invention can be used, in particular, as a constituent material for sealing materials 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. Alternatively, a build-up film or dry film solder resist can be obtained by applying the varnish to a peelable plastic film as a substrate and drying the plastic film. 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 simply been dried, or can be used in a semi-cured (B-staged) state as necessary. [Example]

[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: Tosoh Corporation HLC-8320GPC Developing solvent: tetrahydrofuran (THF) Flow rate: 0.6mL / min Detector: Refractive index detector (RI) Column: TSK Guardcolumn SuperH-H TSKgel SuperHM-N(6.0mmI.D.×15cm×1) TSKgel SuperH2500(6.0mmI.D.×15cm×1) (All manufactured by Tosoh Corporation) Column temperature: 40℃ Sample injection volume: 50 μL (0.3% by mass THF solution) Standard: Monodisperse polystyrene (2) Proton nuclear magnetic resonance spectrum ( 1 H-NMR) measurement conditions Equipment: BURKER AVANCE III400 Solvent: CDCl3 Internal standard: tetramethylsilane (TMS)

[0048] [1] Synthesis of maleimide group-containing organopolysiloxane [Synthesis Example 1] A 1-L separable flask equipped with a stirrer, reflux condenser, dropping funnel, and thermometer was charged with 98.1 parts by mass (1 mole) of maleic anhydride, 300 parts by mass of tetrahydrofuran, and 0.4 parts by mass of the polymerization inhibitor bis-t-butylphenol, and the mixture was stirred and mixed. After the components were uniformly dissolved, 270 parts by mass (1 mole of amino groups) of polydimethylsiloxane (A1) with a primary amino functional group content of 270 g / mol and an aminopropyldimethylsilyl structure at both ends was added dropwise. The dropwise addition generated heat, so a water bath was used to control the temperature of the reaction solution so that it did not exceed 50°C. After the dropwise addition was completed, stirring was continued at room temperature for 1 hour, and the disappearance of the reaction materials was confirmed by GPC. Next, 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 heat generation occurred during the dropwise addition, and the appearance changed from orange to deep red. After the dropwise addition was completed, the reaction was carried out at an internal temperature of 50°C for 3 hours, and 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 resulting organopolysiloxane 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-a) and formula (2-a). The content of formula (2-a) was 86 mol% of the total components.

[0049] [ka] [ka]

[0050] [Synthesis Example 2] The polydimethylsiloxane (A1) having aminopropyldimethylsilyl structures at both ends used in Synthesis Example 1 above was replaced with polydimethylsiloxane (A2) having aminopropyldimethylsilyl structures at both ends and a primary amino functional group amount of 430 g / mol, and the reaction ratio was adjusted accordingly. The same procedure as in Synthesis Example 1 was carried out, yielding a black oily compound (M2). The viscosity of this compound at 25°C was 160 mPa·s. The resulting 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] [ka] [ka]

[0052] [Synthesis Example 3] The polydimethylsiloxane (A1) having aminopropyldimethylsilyl groups at both ends used in Synthesis Example 1 was replaced with polydimethylsiloxane (A3) having aminopropyldimethylsilyl groups at both ends and 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] [ka] [ka]

[0054] [2] Preparation of curable compositions for molding free-standing sheets [Examples 1 to 3, Comparative Examples 1 to 5] The components were mixed in the ratios shown in Table 1 below to prepare thermosetting compositions of Examples 1 to 3 and Comparative Examples 1 to 5. The ratios are expressed as mass ratios. The composition was 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 composition was dissolved and diluted with N-methylpyrrolidinone to make a varnish with a final active ingredient content of 35%.

[0055] [Table 1]

[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": An aromatic compound having two maleimide groups represented by the following formula (manufactured by K.I. Kasei Co., Ltd., product name "BMI-70") "LECY": A bisphenol E compound having two cyanate groups represented by the following formula (manufactured by Lonza Japan, product name "LECy") "Curing catalyst": tetraphenylphosphonium tetraphenylborate (manufactured by Hokko Chemical Industry Co., Ltd., product name "TPP-K")

[0057] [ka]

[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, and the organic solvent (N-methylpyrrolidinone) was evaporated at 200°C for 90 minutes. The mold was then 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 the curing, yielding a sheet test piece.

[0059] The following evaluations were carried out on the sheet molded products obtained in Examples 1 to 3 and Comparative Examples 1 to 5. The results are shown in Table 2. (1)Moldability When the sheet was removed from the mold, it was observed whether it could stand on its own, and the following criteria were determined. ○: It is possible to remove the sheet without any abnormalities. x: Brittle or soft and impossible to take out as a sheet. (2) 90° bending ability The flexibility was evaluated by 90° bending property. The test piece obtained above was cut into a 1 cm width, and then cut into a strip of 10 cm length, 1 cm width, and 0.3 mm thickness. Both short sides were picked up with tweezers and bent 90°. The state of the sheet was observed and judged as follows: ◯: Can be bent without breaking. ×: Completely broken and unable to be bent. (3) Change in appearance at 150℃ The test pieces obtained above were cut into rectangles 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 judged as follows: ○: Almost no change in appearance and no warping observed. ×: Obvious changes in appearance such as warping are observed. (4) Durometer hardness The measurement was carried out 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 of 10 cm length × 1 cm width × 0.3 mm thickness, and measured in tensile measurement mode using a viscoelasticity measuring device DMA7100 manufactured by Hitachi High-Tech Science Corporation, while raising the temperature from -50°C to 300°C at a heating rate of 10°C / min in an air atmosphere. (6) Dielectric constant, 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 ("E5063-2D5" manufactured by Keysight Corporation) was connected to a strip line (manufactured by Keycom Corporation) to measure the relative permittivity and dielectric loss tangent at a frequency of 10 GHz.

[0060] [Table 2]

[0061] The results in Table 2 show 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)) 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), 【Chemical 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): 【Chemistry 2】 (In the formula, R 1 , R 2 , n is the same as above.) and 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). A silicone additive for modifying resins.

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

3. The 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), 【Chemistry 3】 (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): 【Chemistry 4】 (In the formula, R 1 , R 2 , n is the same as above.) a silicone resin component containing the component (II) in an amount of 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 no siloxane bond A curable resin composition comprising:

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

6. The 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. 5. The curable resin composition according to claim 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.

Images