Resin composition, prepreg, resin sheet, printed wiring board, semiconductor package, and semiconductor device

Abstract

The present invention addresses the problem of providing a resin composition with which excellent flame retardancy can be imparted while the reactivity of a boric acid ester with a heat-curable compound is reduced. The resin composition comprises a heat-curable compound (A), a phosphorus compound (B), and a boric acid ester compound (C) represented by formula (1).

Description

Resin composition, prepreg, resin sheet, printed wiring board, semiconductor package, and semiconductor device

[0001] The present invention relates to a resin composition, a prepreg, a resin sheet, a printed wiring board, a semiconductor package, and a semiconductor device.

[0002] Conventionally, halogen compounds such as bromine compounds have been added as flame retardants to printed wiring boards. However, due to their toxicity, halogen compounds have come to be disliked. In recent years, phosphorus compounds have been preferred as flame retardants instead of halogen compounds. However, it is known that the use of phosphorus compounds as flame retardants can sometimes cause deterioration of properties such as low thermal expansion and heat resistance. For this reason, a combination of phosphorus compounds and other flame retardants has been sought that can alleviate these drawbacks while maintaining high flame retardancy.

[0003] On the other hand, it is known that phosphorus compounds act as flame retardants by dehydrating resins with polyphosphoric acid produced by their combustion, which promotes char formation, and blocking oxygen through the char formation. However, phosphorus compounds commonly used as flame retardants may volatilize into the gas phase due to the heat of combustion, and may not be sufficiently effective in the solid phase. To prevent this, a method is known in which a boric acid ester is used in polyurethane foam together with a phosphorus compound (Patent Document 1).

[0004] Japanese Unexamined Patent Publication No. 58-136615

[0005] However, when the technique of combining a phosphorus compound and a boric acid ester is applied to thermosetting compounds for electronic materials, there is a problem in that the varnish gels due to its high reactivity with the thermosetting compound, making it impossible to obtain the desired properties.

[0006] An object of the present invention is to provide a resin composition that can impart excellent flame retardancy while suppressing the reactivity of a boric acid ester with a thermosetting compound.

[0007] Means for Solving the Problems of the Invention The present inventors conducted extensive research to achieve the objects of the present invention and found that by using a specific borate ester in a resin composition containing a thermosetting compound and a phosphorus compound, it is possible to impart excellent flame retardancy while suppressing the reactivity of the borate ester with the thermosetting compound, and thus completed the present invention.

[0008] That is, the present invention is as follows: [1] A resin composition containing a thermosetting compound (A), a phosphorus compound (B), and a borate ester compound (C) represented by the following formula (1):

[0009]

[0010] (In formula (1), each R independently represents an alkyl group having 1 to 8 carbon atoms.) [2] The resin composition according to the above [1], wherein the thermosetting compound (A) contains one or more compounds selected from the group consisting of maleimide compounds, epoxy compounds, and cyanate ester compounds. [3] The resin composition according to the above [1] or [2], wherein the phosphorus compound (B) is halogen-free. [4] The resin composition according to any of the above [1] to [3], wherein the phosphorus compound (B) contains one or more compounds selected from the group consisting of phosphazenes, phosphates, phosphoric acid esters, phosphinates, phosphinate esters, phosphonates, and phosphonate esters. [5] The resin composition according to any of the above [1] to [4], wherein the content of the borate ester compound (C) is 0.5 to 10 parts by mass per 100 parts by mass of the thermosetting compound (A). [6] The resin composition according to any one of [1] to [5] above, wherein the content of the borate ester compound (C) is 10 to 200 parts by mass per 100 parts by mass of the phosphorus compound (B). [7] The resin composition according to any one of [1] to [6] above, further comprising an inorganic filler (D). [8] The resin composition according to [7] above, wherein the content of the inorganic filler (D) is 100 parts by mass or more per 100 parts by mass of the resin solid content in the resin composition. [9] The resin composition according to any one of [1] to [8] above, further comprising an organic filler (E).

[10] The resin composition according to [9] above, wherein the organic filler (E) contains silicone particles.

[11] The resin composition according to any one of [1] to

[10] above, further comprising a silane coupling agent (F).

[12] The resin composition according to the above [1], wherein the thermosetting compound (A) contains one or more compounds selected from the group consisting of maleimide compounds, epoxy compounds, and cyanate ester compounds, the phosphorus compound (B) contains one or more compounds selected from the group consisting of phosphazenes, phosphates, phosphoric acid esters, phosphinates, phosphinate esters, phosphonates, and phosphonate esters, and the content of the borate ester compound (C) is 0.5 to 10 parts by mass relative to 100 parts by mass of the thermosetting compound (A) and 10 to 200 parts by mass relative to 100 parts by mass of the phosphorus compound (B).

[13] The resin composition according to

[12] above, further comprising an inorganic filler (D), wherein the content of the inorganic filler (D) is 100 parts by mass or more relative to 100 parts by mass of the resin solid content in the resin composition.

[14] The resin composition according to any one of [1] to

[13] above, which is used for forming an insulating layer of a printed wiring board.

[15] A prepreg comprising a substrate and the resin composition according to any one of [1] to

[13] above, impregnated into or coated on the substrate.

[16] A resin sheet comprising a support and a resin composition layer formed from the resin composition according to any one of [1] to

[13] above, provided on the support.

[17] A printed wiring board comprising an insulating layer containing a cured product formed by curing the resin composition according to any one of [1] to

[13] above.

[18] A semiconductor package comprising the printed wiring board according to

[17] above and a semiconductor element.

[19] A semiconductor device comprising the printed wiring board according to

[17] above.

[0011] According to the resin composition of the present invention, it is possible to impart excellent flame retardancy while suppressing the reactivity of the boric acid ester with the thermosetting compound.

[0012] The present invention will be described in detail below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and can be implemented with any modifications within the scope of the claims of the present invention and their equivalents.

[0013] Unless otherwise specified, the term "resin solid content" as used in this specification refers to the components in a resin composition excluding the solvent, inorganic filler, and organic filler, and 100 parts by mass of resin solid content means that the total of the components in a resin composition excluding the solvent, inorganic filler, and organic filler is 100 parts by mass.

[0014] [Resin Composition] The resin composition of the present invention contains a thermosetting compound (A), a phosphorus compound (B), and a borate ester compound (C) represented by the following formula (1): Such a resin composition can impart excellent flame retardancy while suppressing the reactivity between the borate ester compound (C) and the thermosetting compound (A).

[0015]

[0016] (In formula (1), each R independently represents an alkyl group having 1 to 8 carbon atoms.)

[0017] [Thermosetting Compound (A)] The resin composition of the present invention contains a thermosetting compound (A).

[0018] The thermosetting compound (A) is not particularly limited, but examples thereof include maleimide compounds, cyanate ester compounds, epoxy compounds, compounds having a terminal ethylenically unsaturated group, phenol compounds, oxetane compounds, benzoxazine compounds, and organic group-modified silicone compounds. The thermosetting compound (A) may be used alone or in combination of two or more. The thermosetting compound (A) preferably contains one or more compounds selected from the group consisting of maleimide compounds, epoxy compounds, and cyanate ester compounds.

[0019] (Maleimide Compound) The maleimide compound is a compound having one or more maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl groups) per molecule. From the viewpoint of further improving heat resistance, the maleimide compound is preferably a maleimide compound having two or more maleimide groups per molecule. In one embodiment, the maleimide compound more preferably includes a maleimide compound having three or more maleimide groups per molecule.

[0020] The maleimide compound may be an aromatic maleimide compound containing an aromatic carbon ring (particularly a benzene ring) in the molecule, or an aliphatic maleimide compound not containing an aromatic carbon ring in the molecule, or may contain both of these, but in one embodiment, it preferably contains an aromatic maleimide compound containing an aromatic carbon ring in the molecule. Among these, it is preferable to contain an aromatic maleimide compound having a maleimide group directly bonded to an aromatic carbon atom, and it is particularly preferable to contain a maleimide compound having two or more aromatic carbon rings (particularly benzene rings) to which maleimide groups are directly bonded in one molecule.

[0021] Examples of the maleimide compound include monofunctional maleimide compounds having one maleimide group in one molecule (e.g., N-phenylmaleimide, N-hydroxyphenylmaleimide, etc.), bifunctional maleimide compounds having two maleimide groups in one molecule (e.g., bis(4-maleimidophenyl)methane, 2,2-bis{4-(4-maleimidophenoxy)-phenyl}propane, bis(3-ethyl-5-methyl-4-maleimidophenyl)methane, bis(3,5-dimethyl-4-maleimidophenyl)methane, bis(3,5-diethyl-4-maleimidophenyl)methane), m-phenylmaleimide,

[0033] Examples of the maleimide compounds include phenylene bismaleimide, 4-methyl-1,3-phenylene bismaleimide, 1,6'-bismaleimide-(2,2,4-trimethyl)hexane, bisphenol M type maleimide, maleimide compounds having a carbon skeleton derived from dimer acid, maleimide compounds having an indane ring skeleton, etc.), dicyclopentadiene type maleimide compounds, novolac type maleimide compounds, aralkyl type maleimide compounds (for example, phenylaralkyl type maleimide compounds, biphenylaralkyl type maleimide compounds, etc.), and prepolymers of these maleimide compounds with amine compounds.

[0022] It is particularly preferred that the maleimide compound contains at least one selected from the group consisting of bis(4-maleimidophenyl)methane, 2,2-bis{4-(4-maleimidophenoxy)-phenyl}propane, bis(3-ethyl-5-methyl-4-maleimidophenyl)methane, novolac-type maleimide compounds, and biphenylaralkyl-type maleimide compounds. One maleimide compound may be used alone, or two or more may be used in combination.

[0023] Examples of novolac-type maleimide compounds include maleimide compounds represented by the following formula (M1): Examples of biphenylaralkyl-type maleimide compounds include maleimide compounds represented by the following formula (M2):

[0024]

[0025] In the formula, R ｍ１each independently represents a hydrogen atom or a methyl group (preferably a hydrogen atom); R ｍ２ each independently represents an alkyl group having 1 to 5 carbon atoms (for example, a methyl group, an ethyl group, an isopropyl group, etc.) or a phenyl group, n ｍ１ indicates the number average degree of polymerization, and 1<n ｍ１ <10 (preferably 1 < n ｍ１ <6), and n ｍ２ are each independently 0, 1 or 2 (preferably 0).

[0026] The maleimide compound may be a commercially available product, or a preparation prepared by a known method. Commercially available maleimide compounds include "BMI-70", "BMI-80", and "BMI-1000P" manufactured by K.I. Kasei Co., Ltd., "BMI-3000", "BMI-4000", "BMI-5100", "BMI-7000", and "BMI-2300" manufactured by Daiwa Kasei Kogyo Co., Ltd., "MIR-3000" and "MIR-5000" manufactured by Nippon Kayaku Co., Ltd., "NE-X-9470S" and "NE-X-9500" manufactured by DIC Corporation, "SFR" manufactured by Resonac Inc., and "BMI-689", "BMI-3000", and "BMI-5000" manufactured by Designer Molecules Inc.

[0027] From the viewpoint of increasing the number of crosslinking points and more effectively improving the heat resistance of the resulting cured product, the maleimide group equivalent of the maleimide compound is preferably 1,500 g / eq. or less, more preferably 1,000 g / eq. or less, even more preferably 500 g / eq. or less, still more preferably 300 g / eq. or less, and particularly preferably 200 g / eq. or less, and the lower limit is not particularly limited, but may be, for example, 100 g / eq. or more, 130 g / eq. or more, 150 g / eq. or more, 160 g / eq. or more, etc. The maleimide group equivalent represents the mass of the compound per mole of maleimide groups.

[0028] From the viewpoint of increasing the number of crosslinking points and more effectively improving the heat resistance of the resulting cured product, the weight-average molecular weight of the maleimide compound is preferably 4,000 or less, more preferably 2,000 or less, even more preferably 1,000 or less, still more preferably 800 or less, and particularly preferably 600 or less, and the lower limit is not particularly limited, but may be, for example, 200 or more, 300 or more, etc. The weight-average molecular weight of the maleimide compound is a weight-average molecular weight in terms of polystyrene measured by gel permeation chromatography.

[0029] When the resin composition contains a maleimide compound, the content of the maleimide compound relative to 100 parts by mass of the thermosetting compound (A) is not particularly limited, but is preferably 80 parts by mass or less, more preferably 60 parts by mass or less, and even more preferably 50 parts by mass or less, and may be 40 parts by mass or less or 30 parts by mass or less depending on the application, etc. The lower limit of the content is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and may be 10 parts by mass or more, 15 parts by mass or more, or 20 parts by mass or more depending on the application, etc.

[0030] (Cyanate Ester Compound) A cyanate ester compound is a compound having one or more cyanate ester groups (cyanato groups) per molecule. The cyanate ester compound preferably includes a cyanate ester compound containing two or more cyanato groups per molecule. In one embodiment, the cyanate ester compound preferably includes a cyanate ester compound having one or more aromatic carbon rings (particularly, a benzene ring or a naphthalene ring) per molecule, more preferably includes a cyanate ester compound having two or more aromatic carbon rings (particularly, a benzene ring or a naphthalene ring) per molecule, and particularly preferably includes a cyanate ester compound having two or more aromatic carbon rings (particularly, a benzene ring or a naphthalene ring) to which cyanato groups are directly bonded per molecule. In one embodiment, the cyanate ester compound preferably includes a cyanate ester compound having three or more cyanato groups per molecule.

[0031] Examples of cyanate ester compounds include benzene compounds substituted with two or three cyanato groups (e.g., 1,3-dicyanatobenzene, 1,4-dicyanatobenzene, 1,3,5-tricyanatobenzene, etc.), naphthalene compounds substituted with two or three cyanato groups (e.g., 1,3-dicyanatonaphthalene, 1,4-dicyanatonaphthalene, 1,6-dicyanatonaphthalene, 1,8-dicyanatonaphthalene, 2,6-dicyanatonaphthalene, 2,7-dicyanatonaphthalene, 1,3,6-tricinatonaphthalene, etc.), biphenyl compounds substituted with two or three cyanato groups (e.g., 4,4′-dicyanatobiphenyl, etc.), novolac-type cyanate esters, aralkyl-type cyanate esters (e.g., phenol aralkyl-type cyanate esters, naphthol aralkyl-type cyanate esters, etc.), and the like. , biphenylaralkyl-type cyanate esters, etc.), bisphenol-type cyanate esters (for example, bisphenol A-type cyanate esters, bisphenol E-type cyanate esters, bisphenol F-type cyanate esters, bisphenol AD-type cyanate esters, bisphenol B-type cyanate esters, bisphenol AP-type cyanate esters, bisphenol S-type cyanate esters, bisphenol Z-type cyanate esters, bisphenol TMC-type cyanate esters, etc.), diallyl bisphenol-type cyanate esters (for example, diallyl bisphenol A-type cyanate esters, diallyl bisphenol F-type cyanate esters, diallyl bisphenol E-type cyanate esters, diallyl bisphenol S-type cyanate esters, etc.), and prepolymers of these cyanate esters. Among these, from the viewpoint of achieving even more excellent heat resistance and flame retardancy, the cyanate ester compound preferably contains one or more compounds selected from the group consisting of bisphenol A-type cyanate esters, naphthol aralkyl-type cyanate esters, biphenylaralkyl-type cyanate esters, and diallyl bisphenol-type cyanate esters. The cyanate ester compounds may be used alone or in combination of two or more.

[0032] Examples of novolac-type cyanate esters include compounds represented by the following formula (C1): phenol aralkyl-type cyanate esters include compounds represented by the following formula (C2): naphthol aralkyl-type cyanate esters include compounds represented by the following formula (C3): biphenyl aralkyl-type cyanate esters include compounds represented by the following formula (C4):

[0033]

[0034] In the formula, R ｃ１ each independently represents a hydrogen atom or a methyl group (preferably a hydrogen atom); R ｃ２ each independently represents an alkyl group having 1 to 5 carbon atoms (for example, a methyl group, an ethyl group, an isopropyl group, etc.) or a phenyl group, n ｃ１ indicates the number average degree of polymerization, and 1<n ｃ１ <10 (preferably 1 < n ｃ１ <6), and n ｃ２ are each independently 0, 1 or 2 (preferably 0).

[0035] The cyanate ester compound may be a commercially available product or a product synthesized by a known method. Examples of commercially available cyanate ester compounds include "CA210" and "NCN-M" manufactured by Mitsubishi Gas Chemical Company, Inc.

[0036] From the viewpoint of increasing crosslinking points and more effectively improving the heat resistance and copper foil adhesion of the resulting cured product, the cyanate ester compound has a cyanate group equivalent of preferably 1,500 g / eq. or less, more preferably 1,000 g / eq. or less, even more preferably 500 g / eq. or less, and still more preferably 300 g / eq. or less. The lower limit is not particularly limited, but may be, for example, 100 g / eq. or more, 130 g / eq. or more, 150 g / eq. or more, 170 g / eq. or more, etc. The cyanate group equivalent represents the mass of the compound per mole of cyanate groups.

[0037] From the viewpoint of increasing the number of crosslinking points and more effectively improving the heat resistance and copper foil adhesion of the resulting cured product, the weight average molecular weight of the cyanate ester compound is preferably 4,000 or less, more preferably 2,000 or less, even more preferably 1,500 or less, still more preferably 1,000 or less, and particularly preferably 800 or less, and the lower limit is not particularly limited, but may be, for example, 200 or more, 300 or more, 400 or more, etc. The weight average molecular weight of the cyanate ester compound is a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography.

[0038] When the resin composition contains a cyanate ester compound, the content of the cyanate ester compound relative to 100 parts by mass of the thermosetting compound (A) is not particularly limited, but is preferably 80 parts by mass or less, more preferably 60 parts by mass or less, and even more preferably 50 parts by mass or less, and may be 40 parts by mass or less or 30 parts by mass or less depending on the application, etc. The lower limit of the content is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and may be 10 parts by mass or more, 15 parts by mass or more, or 20 parts by mass or more depending on the application, etc.

[0039] (Epoxy Compound) The epoxy compound is a compound having one or more epoxy groups in one molecule. The epoxy compound preferably includes an epoxy compound having two or more epoxy groups in one molecule. In one embodiment, the epoxy compound preferably includes an epoxy compound having one or more aromatic carbon rings (particularly, a benzene ring or a naphthalene ring) in one molecule, and more preferably includes an epoxy compound having two or more aromatic carbon rings (particularly, a benzene ring or a naphthalene ring) in one molecule. In one embodiment, the epoxy compound preferably includes an epoxy compound having three or more epoxy groups in one molecule.

[0040] Examples of epoxy compounds include bisphenol type epoxy resins (e.g., bisphenol A type epoxy resins, bisphenol E type epoxy resins, bisphenol F type epoxy resins, and bisphenol S type epoxy resins), diallyl bisphenol type epoxy resins (e.g., diallyl bisphenol A type epoxy resins, diallyl bisphenol E type epoxy resins, diallyl bisphenol F type epoxy resins, and diallyl bisphenol S type epoxy resins), trisphenolmethane type epoxy resins, novolac type epoxy resins (e.g., phenol novolac type epoxy resins, bisphenol A novolac type epoxy resins, cresol novolac type epoxy resins, naphthol

[0033] Examples of epoxy resins that can be used include aryl-cresol novolac epoxy resins), aralkyl epoxy resins (for example, biphenylaralkyl epoxy resins, phenolaralkyl epoxy resins, naphtholaralkyl epoxy resins, etc.), biphenyl epoxy resins, naphthylene ether epoxy resins, anthracene epoxy resins, glycidyl ester epoxy resins, polyol epoxy resins, isocyanurate ring-containing epoxy resins, dicyclopentadiene epoxy resins, epoxy resins composed of bisphenol A structural units and hydrocarbon-based structural units, and halogen compounds thereof (for example, brominated bisphenol A epoxy resins, brominated phenol novolac epoxy resins).

[0041] The epoxy compound may be a commercially available product, or a preparation prepared by a known method may be used. Commercially available epoxy compounds include "NC-7000", "NC-7300", and "NC-7300L" manufactured by Nippon Kayaku Co., Ltd., "HP-9540" and "HP-9500" (naphthol-cresol novolac epoxy resin) manufactured by DIC Corporation; "Epotohto ESN-155", "Epotohto ESN-355", "Epotohto ESN-375", "Epotohto ESN-475V", "Epotohto ESN-485", and "Epotohto ESN-175" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., and "HP-5000" and "HP- Examples of epoxy resins include "NC-9900" (naphthol aralkyl type epoxy resin); "NC-3000", "NC-3000H", "NC-3000L", and "NC-3000FH" (biphenyl aralkyl type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "HP-4710" (naphthalene type epoxy resin) manufactured by DIC Corporation; and "HP-4032", "HP-6000", "EXA-7300", "EXA-7310", "EXA-7311", "EXA-7311L", and "EXA7311-G3" (naphthylene ether type epoxy resin) manufactured by DIC Corporation.

[0042] From the viewpoint of increasing the number of crosslinking points and more effectively improving the heat resistance and copper foil adhesion of the resulting cured product, the epoxy group equivalent of the epoxy compound is preferably 1,500 g / eq. or less, more preferably 1,000 g / eq. or less, even more preferably 500 g / eq. or less, and still more preferably 300 g / eq. or less. The lower limit is not particularly limited, but can be, for example, 100 g / eq. or more, 130 g / eq. or more, 150 g / eq. or more, 170 g / eq. or more, etc. The epoxy group equivalent represents the mass of the compound per mole of epoxy groups.

[0043] From the viewpoint of increasing the number of crosslinking points and more effectively improving the heat resistance and copper foil adhesion of the resulting cured product, the weight average molecular weight of the epoxy compound is preferably 4,000 or less, more preferably 2,000 or less, even more preferably 1,500 or less, still more preferably 1,000 or less, and particularly preferably 800 or less, and the lower limit is not particularly limited, but may be, for example, 200 or more, 300 or more, 400 or more, etc. The weight average molecular weight of the epoxy compound is a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography.

[0044] When the resin composition contains an epoxy compound, the content of the epoxy compound relative to 100 parts by mass of the thermosetting compound (A) is not particularly limited, but is preferably 80 parts by mass or less, more preferably 60 parts by mass or less, and even more preferably 50 parts by mass or less, and may be 40 parts by mass or less or 30 parts by mass or less depending on the application, etc. The lower limit of the content is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and may be 10 parts by mass or more, 15 parts by mass or more, or 20 parts by mass or more depending on the application, etc.

[0045] When the resin composition contains both an epoxy compound and a maleimide compound, the mass ratio of the epoxy compound to the maleimide compound in the resin composition (epoxy compound / maleimide compound) is not particularly limited, but is preferably 0.1 or more, more preferably 0.5 or more, even more preferably 1 or more, and particularly preferably 1.5 or more, and the upper limit is preferably 30 or less, more preferably 10 or less, even more preferably 5 or less, and particularly preferably 2 or less.

[0046] When the resin composition contains both an epoxy compound and a cyanate ester compound, the mass ratio of the epoxy compound to the cyanate ester compound in the resin composition (epoxy compound / cyanate ester compound) is not particularly limited, but is preferably 0.05 or more, more preferably 0.1 or more, even more preferably 0.5 or more, and particularly preferably 1 or more, and the upper limit is preferably 20 or less, more preferably 10 or less, even more preferably 2 or less, and particularly preferably 1.2 or less.

[0047] When the resin composition contains an epoxy compound, it may further contain an epoxy resin curing agent other than a maleimide compound, a cyanate ester compound, a phenol compound, and a benzoxazine compound as the thermosetting compound (A). Examples of such epoxy resin curing agents include an active ester compound, a carbodiimide compound, and an acid anhydride.

[0048] (Compound Having a Terminal Ethylenically Unsaturated Group) A compound having a terminal ethylenically unsaturated group is a compound having one or more terminal ethylenically unsaturated groups, such as an acryloyl group, a methacryloyl group, a vinylbenzyl group, or an allyl group, per molecule. Examples of compounds having a terminal ethylenically unsaturated group include polyphenylene ether compounds having a terminal ethylenically unsaturated group, and allyl-substituted nadimide compounds. Examples of polyphenylene ether compounds having a terminal ethylenically unsaturated group include polyphenylene ether compounds having a vinylbenzyl group at the terminal and polyphenylene ether compounds having a methacryloyl group at the terminal. The polyphenylene ether compound having a terminal ethylenically unsaturated group may be produced by a known method, or a commercially available product may be used. An example of a commercially available product is "SA9000" manufactured by SABIC Innovative Plastics, which is a polyphenylene ether compound having a methacryloyl group at the terminal. Examples of polyphenylene ether compounds having terminal vinylbenzyl groups include "OPE-2St1200" and "OPE-2St2200" manufactured by Mitsubishi Gas Chemical Company, Inc. Examples of polyphenylene ether compounds having terminal vinylbenzyl groups include polyphenylene ether compounds having terminal hydroxyl groups, such as "SA90" manufactured by SABIC Innovative Plastics, in which the terminals have been modified to vinylbenzyl groups using vinylbenzyl chloride or the like. The allyl-substituted nadimide compound may be a commercially available product, or a product manufactured in accordance with a known method. Examples of commercially available products include "BANI-M" and "BANI-X" manufactured by Maruzen Petrochemical Co., Ltd.

[0049] (Phenol Compound) A phenol compound is a compound having two or more phenolic hydroxyl groups in one molecule. Examples of phenol compounds include bisphenols (e.g., bisphenol A, bisphenol E, bisphenol F, bisphenol S, etc.), diallyl bisphenols (e.g., diallyl bisphenol A, diallyl bisphenol E, diallyl bisphenol F, diallyl bisphenol S, etc.), biphenols (biphenyl-type phenolic compounds), novolak resins (e.g., phenol novolak resin, naphthol novolak resin, cresol novolak resin, etc.), naphthalene-type phenolic resins, dihydroanthracene-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins (e.g., phenol aralkyl-type phenolic resin, naphthol aralkyl-type phenolic resin, biphenyl aralkyl-type phenolic resin, etc.). These phenol compounds may be used alone or in combination of two or more. Commercially available phenolic compounds may be used, or products synthesized by known methods may be used. Commercially available phenolic compounds include "KAYAHARD GPH-65," "KAYAHARD GPH-78," and "KAYAHARD GPH-103" (biphenylaralkyl phenolic resins) manufactured by Nippon Kayaku Co., Ltd., and "SN-495" (naphtholaralkyl phenolic resin) manufactured by Nippon Steel Chemical Co., Ltd.

[0050] (Oxetane Compound) Examples of the oxetane compound include alkyl oxetanes such as oxetane, 2-methyloxetane, 2,2-dimethyloxetane, 3-methyloxetane, and 3,3-dimethyloxetane, 3-methyl-3-methoxymethyloxetane, 3,3'-di(trifluoromethyl)perfluoxetane, 2-chloromethyloxetane, 3,3-bis(chloromethyl)oxetane, and biphenyl-type oxetane. As the oxetane compound, commercially available products may be used, or products produced in accordance with known methods may be used. Examples of commercially available products include "OXT-101" and "OXT-121" manufactured by Toagosei Co., Ltd.

[0051] (Benzoxazine Compound) The benzoxazine compound is a compound having two or more dihydrobenzoxazine rings in one molecule, and examples thereof include "bisphenol F-type benzoxazine BF-BXZ" and "bisphenol S-type benzoxazine BS-BXZ" manufactured by Konishi Chemical Co., Ltd.

[0052] (Organic group-modified silicone compound) Examples of the organic group-modified silicone compound include bis(methylamino)polydimethylsiloxane, bis(propylamino)polydimethylsiloxane, bis(octylamino)polydimethylsiloxane, bis(glycidoxypropyl)polydimethylsiloxane, and bis(glycidoxyoctyl)polydimethylsiloxane. As the organic group-modified silicone compound, a commercially available product may be used, or a product produced according to a known method may be used.

[0053] The content of the thermosetting compound (A) relative to 100 parts by mass of the resin solid content in the resin composition is not particularly limited, but is preferably 99 parts by mass or less, more preferably 95 parts by mass or less, and even more preferably 90 parts by mass or less, and may be 85 parts by mass or less or 80 parts by mass or less depending on the application, etc. The lower limit of the content is preferably 10 parts by mass or more, more preferably 50 parts by mass or more, and even more preferably 60 parts by mass or more, and may be 70 parts by mass or more or 75 parts by mass or more depending on the application, etc.

[0054] [Phosphorus Compound (B)] The resin composition of the present invention contains a phosphorus compound (B). The phosphorus compound (B) can function as a flame retardant in the resin composition of the present invention. The phosphorus compound (B) may be used alone or in combination of two or more.

[0055] The phosphorus compound (B) may be a phosphorus compound containing one phosphorus atom per molecule, a phosphorus compound containing two or more phosphorus atoms per molecule, or a phosphorus compound containing both of these, but preferably contains a phosphorus compound containing two or more phosphorus atoms per molecule.

[0056] The phosphorus compound (B) is not particularly limited, but preferably includes one or more selected from the group consisting of phosphazene, phosphate, phosphoric acid ester, phosphinate, phosphinic acid ester, phosphonate, and phosphonic acid ester, more preferably includes phosphazene or phosphoric acid ester, and even more preferably includes phosphoric acid ester. Furthermore, from the viewpoint of preventing halogen toxicity, the phosphorus compound (B) is preferably halogen-free. Furthermore, in one embodiment, the phosphorus compound (B) preferably includes a compound having a phosphorus atom with an oxidation number of +5.

[0057] Examples of phosphazenes include cyclotriphosphazenes such as hexaphenoxycyclotriphosphazene, triphenoxytris(4-vinylphenoxy)cyclotriphosphazene, triphenoxytris(4-hydroxyphenoxy)cyclotriphosphazene, triphenoxytris(4-aminophenoxy)cyclotriphosphazene, triphenoxytris(4-methylphenoxy)cyclotriphosphazene, triphenoxytris(4-cyanophenoxy)cyclotriphosphazene, hexakis(4-hydroxyphenoxy)cyclotriphosphazene, hexakis(4-aminophenoxy)cyclotriphosphazene and triphenoxytris[4-(2-glycidyloxyethyl)phenoxy]cyclotriphosphazene; and cyclotetraphosphazenes such as octaphenoxycyclotetraphosphazene.

[0058] Examples of phosphinates include dialkylphosphinates such as aluminum tris(diethylphosphinate), zinc bis(diethylphosphinate), aluminum tris(methylethylphosphinate), zinc bis(methylethylphosphinate), and titanium tetrakis(diethylphosphinate); and diarylphosphinates such as zinc bis(diphenylphosphinate) and titanium tetrakis(diphenylphosphinate).

[0059] Examples of phosphinate esters include acyclic diarylphosphinate esters such as phenyl diphenylphosphinate, methyl diphenylphosphinate, and ethyl diphenylphosphinate; 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; 10-(1,4-dihydroxy-2-naphthyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; Cyclic diarylphosphinic acid esters such as phenanthrene-10-oxide, 10-(2,5-dihydroxybiphenyl-4-yl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and 10-[2,4-di(glycidyloxy)phenyl]-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; Cyclic monoarylphosphinic acid esters such as phenanthrene-10-oxide; 9,10-dihydro-10-benzyl-9-oxa-10-phosphaphenanthrene-10-oxide, 10-[2,3-bis(2-hydroxyethoxycarbonyl)propyl]-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide or polyether polycondensates thereof, 10-(2-cyanoethyl)-9,10-di Examples of the aryl phosphinic acid ester include cyclic arylalkyl phosphinic acid esters such as 10-[2-(3,4-epoxycyclohexyl)ethyl]-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-[2-(3,4-epoxycyclohexyl)ethyl]-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and 10-(3-glycidyloxypropyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0060] Examples of phosphonates include zinc methanephosphonate, zinc ethylphosphonate, zinc butylphosphonate, and zinc phenylphosphonate.

[0061] Examples of phosphonate esters include diphenyl methanephosphonate, diethyl phenylphosphonate, dibutyl butylphosphonate, and diethyl ethylphosphonate.

[0062] Examples of phosphates include ammonium phosphate, melamine phosphate, ammonium polyphosphate, and melamine polyphosphate.

[0063] Examples of the phosphate ester include aliphatic phosphate esters such as non-halogenated aliphatic phosphate esters such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri(2-ethylhexyl)phosphate, and trioctyl phosphate; and halogenated aliphatic phosphate esters such as tris(1-chloro-2-propyl)phosphate, tris(1,3-dichloro-2-propyl)phosphate, and tris[3-bromo-2,2-bis(bromomethyl)propyl]phosphate; tetrakis(2,6-dimethylphenyl)1,3-phenylene bisphosphate, tetraphenyl 1,3-phenylene bisphosphate, bisphenol A bis(diphenyl phosphate), triphenyl phosphate, and cresyl diphenyl phosphate. Examples of the aromatic phosphate ester include non-halogen aromatic phosphate esters such as octyldiphenylphosphate, dicresyl phenyl phosphate, tricresyl phosphate, trixylenyl phosphate, 2-ethylhexyl diphenyl phosphate, tert-butylphenyl diphenyl phosphate, bis-(tert-butylphenyl)phenyl phosphate, tris-(tert-butylphenyl)phosphate, tris(4-isopropylphenyl)phosphate, bis(isopropylphenyl)phenyl phosphate, 4-isopropylphenyl diphenyl phosphate, 4-hydroxyphenyl diphenyl phosphate, and octyl diphenyl phosphate; and halogen aromatic phosphate esters such as 4-chlorophenyl diphenyl phosphate.

[0064] Among these, the phosphate ester preferably includes an aromatic phosphate ester, and particularly preferably includes an aromatic condensed phosphate ester containing two or more phosphorus atoms per molecule (e.g., tetrakis(2,6-dimethylphenyl)1,3-phenylene bisphosphate, tetraphenyl 1,3-phenylene bisphosphate, bisphenol A bis(diphenyl phosphate), etc.).

[0065] Examples of aromatic condensed phosphate esters include compounds represented by the following formula (P).

[0066]

[0067] In formula (P), Ar １ and Ar ２ each independently represents an aromatic carbocyclic ring which may have a substituent, and X represents a bond, —O—, —S—, —CO—, or —SO ２ - or - C(R １ ) ２ - indicates R １ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or an aralkyl group, or two R １ are bonded together to form a cycloalkane ring which may be substituted with an alkyl group or an alkenyl group, and n is 0 or 1 (preferably 0).

[0068] The aromatic carbocycle refers to a carbocycle whose ring constituent atoms are exclusively carbon atoms according to the Huckel rule, in which the number of electrons contained in the π electron system on the ring is 4p+2 (p is a natural number). The aromatic carbocycle is preferably a 6- to 14-membered aromatic carbocycle, more preferably a 6- to 10-membered aromatic carbocycle. Examples of the aromatic carbocycle include a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthrene ring, more preferably a benzene ring or a naphthalene ring, and particularly preferably a benzene ring.

[0069] Ar １ and Ar ２ The substituent of the aromatic carbocyclic ring in the formula (I) is not particularly limited, but examples thereof include -R ２ , -OR ２ , -COR ２ , -SR ２ , -SO ２ R ２ , -NHR ２ , -N(R ２ ) ２ , -COOR ２ , -OCOR ２ , -CONHR ２ , -CON(R ２ ) ２ , -NHCOR２ etc. (R ２ each independently represents an alkyl group, an alkenyl group, an aryl group or an aralkyl group.

[0070] The alkyl group refers to a linear, branched, and / or cyclic monovalent aliphatic saturated hydrocarbon group. Unless otherwise specified, the alkyl group is preferably an alkyl group having 1 to 14 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, even more preferably an alkyl group having 1 to 8 carbon atoms, and particularly preferably an alkyl group having 1 to 5 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isopentyl group, a sec-pentyl group, a neopentyl group, a tert-pentyl group, a hexyl group, an isohexyl group, a cyclopentyl group, and a cyclohexyl group. The alkenyl group refers to a linear, branched, and / or cyclic monovalent aliphatic unsaturated hydrocarbon group having at least one carbon-carbon double bond. Unless otherwise specified, the alkenyl (group) is preferably an alkenyl group having 2 to 14 carbon atoms, more preferably an alkenyl group having 2 to 10 carbon atoms, still more preferably an alkenyl group having 2 to 8 carbon atoms, and particularly preferably an alkenyl group having 2 to 5 carbon atoms. Examples of the alkenyl group include a vinyl group, a propenyl group (allyl group, 1-propenyl group, isopropenyl group), a butenyl group (1-butenyl group, crotyl group, methallyl group, isocrotyl group, etc.), a pentenyl group (1-pentenyl group, etc.), a hexenyl group (1-hexenyl group, etc.), a heptenyl group (1-heptenyl group, etc.), an octenyl group (1-octenyl group, etc.), a cyclopentenyl group (2-cyclopentenyl group, etc.), and a cyclohexenyl group (3-cyclohexenyl group, etc.).

[0071] The term "aryl group" refers to a monovalent aromatic hydrocarbon group formed by removing one hydrogen atom from an aromatic carbon ring. Unless otherwise specified, the aryl group is preferably an aryl group having 6 to 14 carbon atoms, and more preferably an aryl group having 6 to 10 carbon atoms. Examples of the aryl group include a phenyl group, a 1-naphthyl group, and a 2-naphthyl group. The term "aralkyl group" refers to an alkyl group substituted with one or more (preferably one) aryl groups. Unless otherwise specified, the aralkyl group is preferably an aralkyl group having 7 to 15 carbon atoms, and more preferably an aralkyl group having 7 to 11 carbon atoms. Examples of the aralkyl group include a benzyl group, a phenethyl group, a hydrocinnamyl group, an α-methylbenzyl group, an α-cumyl group, a 1-naphthylmethyl group, and a 2-naphthylmethyl group.

[0072] The cycloalkane ring refers to a saturated carbocyclic ring containing only carbon atoms as ring-constituting atoms. The cycloalkane ring is preferably a cycloalkane ring having 3 to 20 carbon atoms, and more preferably a cycloalkane ring having 5 to 12 carbon atoms. Examples of the cycloalkane ring include monocyclic saturated carbocyclic rings such as a cyclobutane ring, cyclopentane ring, cyclohexane ring, cycloheptane ring, cyclooctane ring, cyclodecane ring, and cyclododecane ring; bicyclic saturated carbocyclic rings such as a norbornane ring, decalin ring, and hydrindane ring; and tricyclic saturated carbocyclic rings such as an adamantane ring.

[0073] The phosphate ester may be a mono-substituted phosphate monoester, a di-substituted phosphate diester, or a tri-substituted phosphate triester, but preferably includes a tri-substituted phosphate triester.

[0074] The molecular weight (or chemical formula weight) of the phosphorus compound (B) is not particularly limited, but is preferably 10,000 or less, more preferably 5,000 or less, even more preferably 2,000 or less, and particularly preferably 1,000 or less.

[0075] The phosphorus atom content of the phosphorus compound (B) is not particularly limited, but is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, even more preferably 7% by mass or more, and particularly preferably 8% by mass or more, and the upper limit is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less, even more preferably 12% by mass or less, and particularly preferably 10% by mass or less.

[0076] The content of the phosphorus compound (B) relative to 100 parts by mass of the thermosetting compound (A) is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, even more preferably 10 parts by mass or less, still more preferably 8 parts by mass or less, and particularly preferably 6 parts by mass or less, from the viewpoint of further improving the properties of desmear resistance, heat resistance, and low thermal expansion. The lower limit of the content is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, even more preferably 2 parts by mass or more, still more preferably 3 parts by mass or more, and particularly preferably 4 parts by mass or more, from the viewpoint of further improving the combustion resistance.

[0077] The content of the phosphorus compound (B) relative to 100 parts by mass of the resin solid content in the resin composition is, from the viewpoint of further improving the properties of desmear resistance, heat resistance, and low thermal expansion, preferably 20 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 7 parts by mass or less, and particularly preferably 5 parts by mass or less. From the viewpoint of further improving the combustion resistance, the lower limit of the content is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, even more preferably 2 parts by mass or more, and particularly preferably 3 parts by mass or more.

[0078] [Borate ester compound (C)] The resin composition of the present invention contains a borate ester compound (C) represented by the following formula (1): The borate ester compound (C) can function as a flame retardant together with the phosphorus compound (B) in the resin composition of the present invention.

[0079]

[0080] In formula (1), each R independently represents an alkyl group having 1 to 8 carbon atoms. Examples of the alkyl group having 1 to 8 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cyclopentylmethyl group, and a cyclohexylmethyl group. R is preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and particularly preferably a methyl group.

[0081] The content of the borate ester compound (C) relative to 100 parts by mass of the thermosetting compound (A) is not particularly limited, but from the viewpoint of excellent desmear resistance, it is preferably 25 parts by mass or less, more preferably 20 parts by mass or less, even more preferably 15 parts by mass or less, still more preferably 10 parts by mass or less, and particularly preferably 7 parts by mass or less. From the viewpoint of further improving combustion resistance, the lower limit of the content is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, even more preferably 0.1 parts by mass or more, still more preferably 0.5 parts by mass or more, and particularly preferably 1 part by mass or more.

[0082] The content of the borate ester compound (C) relative to 100 parts by mass of the phosphorus compound (B) is not particularly limited, but from the viewpoint of excellent desmear resistance, it is preferably 300 parts by mass or less, more preferably 250 parts by mass or less, even more preferably 200 parts by mass or less, still more preferably 150 parts by mass or less, and particularly preferably 120 parts by mass or less. From the viewpoint of further improving combustion resistance, the lower limit of the content is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, even more preferably 5 parts by mass or more, still more preferably 10 parts by mass or more, and particularly preferably 15 parts by mass or more.

[0083] The content of the borate ester compound (C) relative to 100 parts by mass of the resin solid content in the resin composition is not particularly limited, but from the viewpoint of excellent desmear resistance, it is preferably 25 parts by mass or less, more preferably 20 parts by mass or less, even more preferably 15 parts by mass or less, still more preferably 10 parts by mass or less, and particularly preferably 5 parts by mass or less. From the viewpoint of further improving combustion resistance, the lower limit of the content is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, even more preferably 0.1 parts by mass or more, still more preferably 0.5 parts by mass or more, and particularly preferably 0.7 parts by mass or more.

[0084] [Inorganic Filler (D)] From the viewpoint of further improving low thermal expansion properties, the resin composition of the present invention preferably further contains an inorganic filler (D).

[0085] The inorganic filler (D) is not particularly limited, and examples thereof include silicas, silicon compounds (e.g., white carbon, etc.), metal oxides (e.g., alumina, titanium white, zinc oxide, magnesium oxide, zirconium oxide, etc.), metal nitrides (e.g., boron nitride, aggregated boron nitride, silicon nitride, aluminum nitride, etc.), metal sulfates (e.g., barium sulfate, etc.), metal hydroxides (e.g., aluminum hydroxide, heat-treated aluminum hydroxide (e.g., aluminum hydroxide that has been heat-treated to remove some of the water of crystallization), Examples of inorganic fillers (D) include boehmite, magnesium hydroxide, etc.), molybdenum compounds (e.g., molybdenum oxide, zinc molybdate, etc.), zinc compounds (e.g., zinc borate, zinc stannate, etc.), clay, kaolin, talc, calcined clay, calcined kaolin, calcined talc, mica, E-glass, A-glass, NE-glass, C-glass, L-glass, D-glass, S-glass, M-glass G20, short glass fibers (including fine glass powders such as E-glass, T-glass, D-glass, S-glass, and Q-glass), hollow glass, and spherical glass. One type of inorganic filler (D) can be used alone, or two or more types can be used in combination.

[0086] From the viewpoint of further improving low thermal expansion, the inorganic filler (D) preferably contains one or more selected from the group consisting of silicas, metal hydroxides, and metal oxides, more preferably contains one or more selected from the group consisting of silicas, boehmite, and alumina, and even more preferably contains silicas.

[0087] Examples of silicas include natural silica, fused silica, synthetic silica, aerosil, and hollow silica. Silicas may be used singly or in combination of two or more. Among these, fused silica is preferred from the viewpoint of dispersibility, and two or more types of fused silica having different particle sizes are more preferred from the viewpoint of packing properties and flowability. Commercially available fused silica products include "SFP-120MC" and "SFP-130MC" manufactured by Denka Co., Ltd., and "SC1050-MLQ," "SC1050-MB," "SC2050-MNU," "SC2050-MTX," "SE2053-SQ," "YA050C-MJF," and "YA050C-MJA" manufactured by Admatechs Co., Ltd. The inorganic filler (D) may be surface-treated with a silane coupling agent or the like.

[0088] The average particle size of the inorganic filler (D) is not particularly limited, but is preferably 10 μm or less, more preferably 5 μm or less, even more preferably 3 μm or less, even more preferably 1 μm or less, and particularly preferably 0.8 μm or less. The lower limit is not particularly limited, but is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.1 μm or more, even more preferably 0.3 μm or more, and particularly preferably 0.5 μm or more. The average particle size of the inorganic filler (D) refers to the median diameter (D50) of the inorganic filler (D). Here, the median diameter refers to a particle size such that, when the particle size distribution of a powder is divided into two based on a certain particle size, the volume of the particles on the larger particle size side and the volume of the particles on the smaller particle size side each account for 50% of the total powder. The average particle size (median diameter) of the inorganic filler (D) is measured by a wet laser diffraction / scattering method.

[0089] The specific surface area of ​​the inorganic filler (D) is not particularly limited, but is preferably 0.1 m２ / g or more, more preferably 1m ２ / g or more, more preferably 3m ２ / g or more, particularly preferably 5m ２ / g or more, and the upper limit is not particularly limited, but is preferably 100 m ２ / g or less, more preferably 50m ２ / g or less, more preferably 30m ２ / g or less, and even more preferably 20m ２ / g or less, particularly preferably 10m ２ The specific surface area of ​​the inorganic filler (D) can be calculated by the BET multipoint method using a specific surface area measuring device.

[0090] From the viewpoint of low thermal expansion and moldability, the content of the inorganic filler (D) is preferably 10 parts by mass or more, more preferably 40 parts by mass or more, even more preferably 60 parts by mass or more, still more preferably 80 parts by mass or more, and particularly preferably 100 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. The upper limit of the content is not particularly limited, but is preferably 1,000 parts by mass or less, more preferably 700 parts by mass or less, even more preferably 500 parts by mass or less, still more preferably 300 parts by mass or less, and particularly preferably 200 parts by mass or less.

[0091] [Organic Filler (E)] The resin composition of the present invention may further contain an organic filler (E).

[0092] The organic filler (E) is not particularly limited, and examples thereof include styrene particles, butadiene particles, acrylic particles, silicone particles, etc. The organic filler may be core-shell type particles.

[0093] The organic filler (E) preferably contains silicone particles. Examples of silicone particles include silicone resin particles, silicone rubber particles, and silicone composite particles in which the surface of silicone rubber particles is coated with silicone resin. Among these, silicone composite particles are preferred from the viewpoint of achieving a more excellent rigidity of the cured product and further reducing warpage of printed wiring boards (particularly thin substrates such as multilayer coreless substrates).

[0094] The average particle size of the organic filler (E) is not particularly limited, but is, for example, 0.05 μm or more, preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 1 μm or more, and the upper limit is, for example, 100 μm or less, preferably 50 μm or less, more preferably 30 μm or less, even more preferably 10 μm or less, and particularly preferably 3 μm or less. The average particle size of the organic filler (E) can be determined as a volume-based median diameter. The average particle size (median diameter) of the organic filler (E) is measured by a wet laser diffraction / scattering method.

[0095] The content of the organic filler (E) is not particularly limited, but is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, even more preferably 1 part by mass or more, even more preferably 3 parts by mass or more, and particularly preferably 5 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition, and the upper limit is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 25 parts by mass or less, even more preferably 20 parts by mass or less, and particularly preferably 10 parts by mass or less.

[0096] [Silane Coupling Agent (F)] The resin composition of the present invention may further contain a silane coupling agent (F). When the resin composition contains an inorganic filler (D), the inclusion of the silane coupling agent (F) tends to further improve the dispersibility of the inorganic filler (D) and further improve the adhesive strength between the components of the resin composition and the substrate.

[0097] The silane coupling agent (F) is not particularly limited, and examples thereof include silane coupling agents generally used in the surface treatment of inorganic fillers, such as aminosilane compounds (e.g., γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, etc.), epoxysilane compounds (e.g., γ-glycidoxypropyltrimethoxysilane, etc.), acrylicsilane compounds (e.g., γ-acryloxypropyltrimethoxysilane, etc.), cationic silane compounds (e.g., N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride, etc.), styrylsilane compounds (e.g., styryltrimethoxysilane, etc.), vinylsilane compounds (e.g., vinyltrimethoxysilane, etc.), and phenylsilane compounds. The silane coupling agent (F) may be used alone or in combination of two or more. Among these, the silane coupling agent (F) is preferably an epoxy silane coupling agent. Examples of epoxy-based silane coupling agents include "KBM-403," "KBM-303," "KBM-402," and "KBE-403," which are products of Shin-Etsu Chemical Co., Ltd.

[0098] The content of the silane coupling agent (F) is not particularly limited, but is preferably 0.1 to 10 parts by mass, more preferably 1 to 7 parts by mass, and even more preferably 2 to 5 parts by mass, relative to 100 parts by mass of the resin solid content.

[0099] [Wetting and dispersing agent (G)] The resin composition of the present invention may further contain a wetting and dispersing agent (G). By including the wetting and dispersing agent (G), the dispersibility of the inorganic filler (D) in the resin composition tends to be further improved. The wetting and dispersing agent (G) may be a known dispersant (dispersion stabilizer) used to disperse inorganic fillers, and examples thereof include metal phosphate wetting and dispersing agents, polyurethane wetting and dispersing agents, and acrylic wetting and dispersing agents. Examples of commercially available products include "DISPER BYK-110," "DISPER BYK-111," "DISPER BYK-118," "DISPER BYK-180," "DISPER BYK-161," "BYK-W996," "BYK-W9010," and "BYK-W903," all manufactured by BYK-Chemie Japan. The content of the wetting dispersant (G) is not particularly limited, but is preferably 0.1 to 8 parts by mass, more preferably 0.5 to 5 parts by mass, and even more preferably 0.7 to 3 parts by mass, relative to 100 parts by mass of the resin solid content.

[0100] [Curing Accelerator (H)] The resin composition of the present invention may further contain a curing accelerator (H). The curing accelerator (H) is not particularly limited, but examples thereof include imidazoles such as 2-ethyl-4-methylimidazole and triphenylimidazole; tertiary amines such as N,N-dimethylbenzylamine, N,N-dimethylaniline, N,N-dimethyltoluidine, 2-N-ethylanilinoethanol, tri-n-butylamine, pyridine, quinoline, N-methylmorpholine, triethanolamine, triethylenediamine, tetramethylbutanediamine, and N-methylpiperidine; phenol, xylenol, cresol, Examples of suitable organic metal salts include phenols such as resorcinol and catechol; organic metal salts such as lead naphthenate, lead stearate, zinc naphthenate, zinc octoate, manganese octoate, tin oleate, dibutyltin maleate, manganese naphthenate, cobalt naphthenate, and iron acetylacetonate; those obtained by dissolving these organic metal salts in hydroxyl group-containing compounds such as phenol and bisphenol; inorganic metal salts such as tin chloride, zinc chloride, and aluminum chloride; and organic tin compounds such as dioctyltin oxide, other alkyltins, and alkyltin oxides. Among these, imidazoles and / or organic metal salts are preferred, imidazoles are more preferred, and triphenylimidazole is particularly preferred because it has an excellent pot life, promotes the curing reaction, and tends to further improve the glass transition temperature. The content of the curing accelerator (H) is not particularly limited, but is preferably 0.001 to 5 parts by mass, more preferably 0.01 to 2 parts by mass, and even more preferably 0.05 to 1 part by mass, relative to 100 parts by mass of the resin solid content.

[0101] [Elastomer (I)] The resin composition of the present invention may further contain an elastomer (I). Examples of the elastomer (I) include styrene-based elastomers, olefin-based elastomers, urethane-based elastomers, polyester-based elastomers, polyamide-based elastomers, acrylic elastomers, silicone-based elastomers, and derivatives thereof. The elastomer (I) is composed of a hard segment component and a soft segment component, with the former generally contributing to heat resistance and strength, and the latter contributing to flexibility and toughness. From the viewpoint of further improving heat resistance and insulation reliability, the elastomer (I) is preferably a styrene-based elastomer, an olefin-based elastomer, a polyamide-based elastomer, or a silicone-based elastomer, and more preferably a styrene-based elastomer. The elastomer (I) can be used alone or in combination of two or more types.

[0102] The elastomer (I) may have a reactive functional group at the molecular end or in the molecular chain. Examples of the reactive functional group include an epoxy group, a hydroxyl group, a carboxyl group, an amino group, an amide group, an isocyanato group, an acryloyl group, a methacryloyl group, and a vinyl group. Having such a reactive functional group at the molecular end or in the molecular chain of the elastomer improves compatibility with thermosetting compounds, more effectively reducing internal stress generated during curing of the resin composition, and as a result, significantly reducing warpage of the substrate. From the viewpoint of adhesion to metals, the reactive functional group is preferably an epoxy group, a hydroxyl group, a carboxyl group, an amino group, or an amide group. From the viewpoint of further improving heat resistance and insulation reliability, an epoxy group, a hydroxyl group, a carboxyl group, or an amino group is more preferred.

[0103] The content of the elastomer (I) is preferably 0.1 to 30 parts by mass, more preferably 2 to 20 parts by mass, per 100 parts by mass of the resin solid content in the resin composition, from the viewpoint of effectively achieving low shrinkage and low thermal expansion properties of the cured product.

[0104] [Solvent] The resin composition of the present invention may further contain a solvent. By including a solvent in the resin composition, the viscosity during preparation of the resin composition tends to decrease, leading to improved handleability and improved impregnation into a substrate. The solvent is not particularly limited as long as it can dissolve part or all of the components in the resin composition. Examples of the solvent include ketones (acetone, methyl ethyl ketone, etc.), aromatic hydrocarbons (toluene, xylene, etc.), amides (dimethylformaldehyde, etc.), propylene glycol monomethyl ether and its acetate, etc. These solvents may be used alone or in combination of two or more. Examples of methods for producing the resin composition include a method in which the components are blended in a solvent all at once or sequentially and stirred. In this case, known processes such as stirring, mixing, and kneading are used to uniformly dissolve or disperse the components.

[0105] [Other Additives] The resin composition of the present invention may further contain any additives. Examples of such additives include thermoplastic resins, colorants, radical polymerization initiators, polymerization inhibitors, leveling agents, thickeners, antifoaming agents, UV absorbers, adhesion improvers, adhesion promoters, antioxidants, fluorescent brighteners, surfactants, flame retardants other than the phosphorus compound (B) and the boric acid ester (C), stabilizers, etc. One type of other additive may be used alone, or two or more types may be used in combination at any ratio. The content of the other additives can be appropriately determined by a person skilled in the art.

[0106] [Physical Properties of Cured Resin Composition] The cured resin composition of the present invention may be characterized by excellent flame retardancy. Therefore, in one embodiment, when a flame retardancy test is conducted in accordance with the UL94 vertical flame test method, as in Test Example 4 below, the average burning time per test piece may be preferably 5 seconds or less.

[0107] In one embodiment, the cured product of the resin composition of the present invention may be characterized by low thermal expansion. Thus, in one embodiment, the coefficient of linear thermal expansion (CTE) of the cured product, measured as in Test Example 1 below, may be preferably 20 ppm / °C or less, more preferably 15 ppm / °C or less, even more preferably 10 ppm / °C or less, and particularly preferably 8 ppm / °C or less, in the range of 60°C to 120°C.

[0108] In one embodiment, the cured product of the resin composition of the present invention may be characterized by excellent heat resistance. Thus, in one embodiment, the glass transition temperature (Tg) of the cured product, as measured in accordance with JIS C6481 as in Test Example 2 below, may be preferably 200°C or higher, more preferably 230°C or higher, even more preferably 250°C or higher, and particularly preferably 270°C or higher.

[0109] [Uses] The resin composition of the present invention is suitable for use in the production of printed wiring boards. Therefore, the resin composition of the present invention can be suitably used as a resin composition for forming an insulating layer of a printed wiring board. The resin composition of the present invention can be used in a wide range of applications, such as resin sheets, prepregs, laminates thereof, metal foil-clad laminates, solder resist materials, underfill materials, die bonding materials, and semiconductor encapsulants.

[0110] [Prepreg] The prepreg includes a substrate and a resin composition (the resin composition of the present invention) impregnated into or coated on the substrate. The prepreg may be a prepreg obtained by a known method, specifically, by impregnating or coating the substrate with the resin composition, and then heating and drying the resin composition at 100 to 200°C to bring the resin composition into a semi-cured (B-stage) state.

[0111] The prepreg also includes a form of a cured product obtained by thermally curing a semi-cured prepreg at a heating temperature of 180 to 230° C. for a heating time of 60 to 180 minutes.

[0112] The content of the resin composition (including the filler) in the prepreg is preferably 30 to 90% by mass, more preferably 35 to 85% by mass, and even more preferably 40 to 80% by mass, based on the total amount of the prepreg. By having the content of the resin composition within the above range, moldability tends to be further improved.

[0113] The substrate is not particularly limited, and examples thereof include known substrates used as materials for various printed wiring boards. Specific examples of the substrate include glass substrates, inorganic substrates other than glass (for example, inorganic substrates composed of inorganic fibers other than glass, such as quartz), and organic substrates (for example, organic substrates composed of organic fibers, such as wholly aromatic polyamide, polyester, polyparaphenylenebenzoxazole, and polyimide). These substrates may be used alone or in combination of two or more. Among these, glass substrates are preferred from the viewpoint of having better dimensional stability under heating.

[0114] Examples of fibers constituting the glass substrate include fibers such as E-glass, D-glass, S-glass, T-glass, Q-glass, L-glass, NE-glass, and HME-glass. Among these, the fibers constituting the glass substrate are preferably one or more types of fibers selected from the group consisting of E-glass, D-glass, S-glass, T-glass, Q-glass, L-glass, NE-glass, and HME-glass, from the viewpoint of achieving even better strength and low water absorption.

[0115] The form of the substrate is not particularly limited, but examples thereof include woven fabric, nonwoven fabric, roving, chopped strand mat, surfacing mat, etc. The weaving method of the woven fabric is not particularly limited, but known weaves include plain weave, sieve weave, twill weave, etc., and an appropriate weave can be selected from these known weaves depending on the intended use and performance. In addition, glass woven fabrics obtained by subjecting these to fiber opening treatment or surface treatment with a silane coupling agent or the like are preferably used. The thickness and mass of the substrate are not particularly limited, but typically those of about 0.01 to 0.1 mm are preferably used.

[0116] [Resin Sheet] The resin sheet includes a support and a resin composition layer formed from a resin composition (the resin composition of the present invention) provided on the support. The resin sheet may be formed, for example, by applying the resin composition to one or both sides of the support. The resin sheet can be produced, for example, by directly applying a resin composition used for prepregs to a support such as a metal foil or film and drying the applied resin composition.

[0117] The support is not particularly limited, but may be, for example, a known material used in various printed wiring board materials, and is preferably a resin film or a metal foil. Examples of the resin film and metal foil include resin films such as polyimide film, polyamide film, polyester film, polyethylene terephthalate (PET) film, polybutylene terephthalate (PBT) film, polypropylene (PP) film, and polyethylene (PE) film, and metal foils such as aluminum foil, copper foil, and gold foil. Among these, electrolytic copper foil and PET film are preferred as the support.

[0118] Resin sheets can be obtained, for example, by applying a resin composition to a support and then semi-curing (B-stage) the composition. A preferred method for producing a resin sheet is to produce a composite of a B-stage resin composition layer and a support. Specifically, for example, the resin composition can be applied to a support such as copper foil, followed by semi-curing by heating in a dryer at 100 to 200°C for 1 to 60 minutes to produce a resin sheet. The amount of resin composition adhered to the support is preferably in the range of 1.0 μm to 300 μm in terms of resin thickness of the resin sheet. Alternatively, a single-layer resin sheet can be obtained by peeling or etching the support from the resin sheet. A single-layer resin sheet can also be obtained by supplying a solvent-containing varnish-like resin composition into a mold having a sheet-shaped cavity, drying it, or otherwise molding it into a sheet. Resin sheets and single-layer resin sheets can be used as build-up materials for printed wiring boards.

[0119] [Metal Foil-Clad Laminate] The metal foil-clad laminate includes a laminate formed from one or more materials selected from the group consisting of prepregs and resin sheets, and a metal foil disposed on one or both sides of the laminate. The laminate may be formed from a single prepreg or resin sheet, or may be formed from multiple prepregs and / or resin sheets. The laminate is formed by curing a resin composition of the prepreg and resin sheet. That is, the metal foil-clad laminate includes a cured layer containing a cured product formed by curing a resin composition (the resin composition of the present invention), and a metal foil disposed on one or both sides of the cured layer.

[0120] The metal foil (conductor layer) may be any metal foil used in various printed wiring board materials, such as copper foil, aluminum foil, etc. Examples of copper foil include rolled copper foil, electrolytic copper foil, etc. The thickness of the conductor layer is, for example, 1 to 70 μm, and preferably 1.5 to 35 μm.

[0121] The molding method and molding conditions for the metal foil-clad laminate are not particularly limited, and general techniques and conditions for laminates and multilayer boards for printed wiring boards can be applied. For example, when molding a laminate or metal foil-clad laminate, a multi-stage press, a multi-stage vacuum press, a continuous molding machine, an autoclave molding machine, etc. can be used. In addition, when molding a laminate or metal foil-clad laminate (lamination molding), the temperature is 100 to 300°C, and the pressure is a surface pressure of 2 to 100 kgf / cm. 2 The heating time is generally in the range of 0.05 to 5 hours. Furthermore, if necessary, post-curing can be carried out at a temperature of 150 to 300°C. In particular, when a multi-stage press is used, in order to sufficiently promote the curing of the prepreg, the temperature is set to 200 to 250°C and the pressure to 10 to 40 kgf / cm. 2 The heating time is preferably 80 to 130 minutes, the temperature is 215 to 235°C, and the pressure is 25 to 35 kgf / cm 2 The heating time is more preferably 90 to 120 minutes. It is also possible to form a multilayer board by combining the above-mentioned prepreg with a separately prepared wiring board for an inner layer and laminating it.

[0122] [Printed Wiring Board] The printed wiring board includes an insulating layer containing a cured product formed by curing a resin composition (the resin composition of the present invention). The printed wiring board has an insulating layer and a conductor layer formed on the surface of the insulating layer. The printed wiring board can be formed, for example, by etching the metal foil of a metal foil-clad laminate into a predetermined wiring pattern to form a conductor layer. The printed wiring board may be a printed wiring board including an insulating layer formed of one or more materials selected from the group consisting of the above-mentioned prepreg and a single-layer resin sheet, and a conductor layer formed on the surface of the insulating layer.

[0123] Specifically, a printed wiring board can be manufactured, for example, by the following method. First, a metal foil-clad laminate is prepared. The metal foil of the metal foil-clad laminate is etched into a predetermined wiring pattern to create an inner layer substrate having a conductor layer (inner layer circuit). Next, a predetermined number of prepregs and / or single-layer resin sheets serving as insulating layers and metal foil for the outer layer circuit are laminated in this order on the surface of the conductor layer (interior circuit) of the inner layer substrate, and the laminate is integrally molded (laminate molding) by heating and pressurizing to obtain a laminate. The laminate molding method and molding conditions are the same as those for the above-mentioned metal foil-clad laminate. Next, the laminate is drilled for through holes and via holes, and a plated metal film is formed on the wall surfaces of the holes to establish electrical continuity between the conductor layer (interior circuit) and the metal foil for the outer layer circuit. Next, the metal foil for the outer layer circuit is etched into a predetermined wiring pattern to create an outer layer substrate having a conductor layer (external layer circuit). In this manner, a printed wiring board is manufactured.

[0124] In addition, when a metal foil-clad laminate is not used, a printed wiring board may be produced by forming a conductor layer that will become a circuit on the insulating layer. In this case, the conductor layer may be formed by electroless plating.

[0125] [Semiconductor Package] A semiconductor package is a semiconductor package that includes a printed wiring board and a semiconductor element. A semiconductor package can be manufactured by mounting a semiconductor element such as a semiconductor chip or memory at a specific position on a printed wiring board.

[0126] [Semiconductor Device] The printed wiring board can be used to manufacture semiconductor devices having the printed wiring board, such as personal computers, smartphones, smart watches, digital cameras, televisions, car navigation systems, printers, liquid crystal displays, electronic dictionaries, game consoles, automobiles, ships, trains, and aircraft.

[0127] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these examples. Unless otherwise specified, the temperature conditions are room temperature (25°C), and unless otherwise specified, the pressure conditions are atmospheric pressure (1 atm).

[0128] Synthesis Example 1 With reference to Patent Document 1 (JP-A-58-136615), 61.8 g (1 mol) of boric acid and 315 g (3 mol) of diethanolamine were weighed into a 1 L separable flask, heated to 90 to 100° C. in an oil bath, refluxed for 3 hours, and then cooled to room temperature to obtain boric acid diethanolamine ester as a pale yellow liquid.

[0129] Example 1 25 parts by mass of a phenol novolac maleimide compound (manufactured by Daiwa Chemical Industry Co., Ltd., "BMI-2300"), 35 parts by mass of a naphthol aralkyl cyanate ester compound (manufactured by Mitsubishi Gas Chemical Co., Inc., "NCN-M"), 40 parts by mass of a naphthol-cresol novolac epoxy resin (manufactured by DIC Corporation, "HP-9540"), 150 parts by mass of fused silica (manufactured by Denka Company, Ltd., "SFP-130MC", average particle size 0.6 μm), 10 parts by mass of silicone composite particles (manufactured by Shin-Etsu Chemical Co., Ltd., "KMP-605"), 5 parts by mass of an epoxy silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-403"), 10 parts by mass of a polyurethane wetting and dispersing agent (manufactured by BYK Japan KK, "DISPER"). A varnish-like resin composition was obtained by mixing 1 part by mass of a carboxylic acid ester ("BYK-161" manufactured by Tokyo Chemical Industry Co., Ltd.), 0.5 parts by mass of an imidazole ("TPIZ" manufactured by Tokyo Chemical Industry Co., Ltd., 2,4,5-triphenylimidazole), 5 parts by mass of an aromatic condensed phosphate ester ("PX-200" manufactured by Daihachi Chemical Industry Co., Ltd., tetrakis(2,6-dimethylphenyl)1,3-phenylene bisphosphate), and 1 part by mass of a borate ester compound represented by the following formula (a) (triisopropanolamine borate manufactured by Tokyo Chemical Industry Co., Ltd.) with 19 parts by mass of methyl ethyl ketone (solvent). The amounts of the above-mentioned components used are expressed as solid content values. The same applies hereinafter.

[0130]

[0131] Example 2 A varnish-like resin composition was obtained in the same manner as in Example 1, except that the amount of the boric acid ester compound of formula (a) (triisopropanolamine borate, manufactured by Tokyo Chemical Industry Co., Ltd.) used was changed from 1 part by mass to 3 parts by mass.

[0132] Example 3 A varnish-like resin composition was obtained in the same manner as in Example 1, except that the amount of the boric acid ester compound of formula (a) (triisopropanolamine borate, manufactured by Tokyo Chemical Industry Co., Ltd.) used was changed from 1 part by mass to 5 parts by mass.

[0133] Comparative Example 1 A varnish-like resin composition was obtained in the same manner as in Example 1, except that the amount of the boric acid ester compound of formula (a) (triisopropanolamine borate, manufactured by Tokyo Chemical Industry Co., Ltd.) used was changed from 1 part by mass to 0 part by mass.

[0134] Comparative Example 2 A varnish-like resin composition was obtained in the same manner as in Example 1, except that the amount of the borate ester compound of formula (a) (triisopropanolamine borate, manufactured by Tokyo Chemical Industry Co., Ltd.) used was changed from 1 part by mass to 3 parts by mass, and the amount of the aromatic condensed phosphate ester (tetrakis(2,6-dimethylphenyl)1,3-phenylene bisphosphate, "PX-200", manufactured by Daihachi Chemical Industry Co., Ltd.) used was changed from 5 parts by mass to 0 parts by mass.

[0135] Comparative Example 3 An attempt was made to obtain a varnish-like resin composition in the same manner as in Example 1, except that 3 parts by mass of a borate ester compound of the following formula (b) (triethanolamine borate, manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of 1 part by mass of the borate ester compound of formula (a) (triisopropanolamine borate, manufactured by Tokyo Chemical Industry Co., Ltd.). However, the solubility of the borate ester compound was low, and a uniform varnish could not be obtained, so the investigation was discontinued.

[0136]

[0137] Comparative Example 4 An attempt was made to obtain a varnish-like resin composition in the same manner as in Example 1, except that 3 parts by mass of boric acid (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of 1 part by mass of the borate ester compound of formula (a) (triisopropanolamine borate, manufactured by Tokyo Chemical Industry Co., Ltd.). However, the composition gelled, and a varnish-like resin composition could not be obtained.

[0138] Comparative Example 5 An attempt was made to obtain a varnish-like resin composition in the same manner as in Example 1, except that 3 parts by mass of trimethyl borate (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of 1 part by mass of the borate ester compound of formula (a) (triisopropanolamine borate, manufactured by Tokyo Chemical Industry Co., Ltd.). However, the composition gelled, and a varnish-like resin composition could not be obtained.

[0139] Comparative Example 6 An attempt was made to obtain a varnish-like resin composition in the same manner as in Example 1, except that 3 parts by mass of triethyl borate (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of 1 part by mass of the borate ester compound of formula (a) (triisopropanolamine borate, manufactured by Tokyo Chemical Industry Co., Ltd.). However, the composition gelled, and a varnish-like resin composition could not be obtained.

[0140] Comparative Example 7 An attempt was made to obtain a varnish-like resin composition in the same manner as in Example 1, except that 3 parts by mass of the borate ester compound obtained in Synthesis Example 1 was used instead of 1 part by mass of the borate ester compound of formula (a) (triisopropanolamine borate, manufactured by Tokyo Chemical Industry Co., Ltd.). However, the composition gelled, and a varnish-like resin composition could not be obtained.

[0141] (Preparation of Metal Foil-Clad Laminate) The varnish-like resin compositions obtained in each of Examples 1 to 3 and Comparative Examples 1 and 2 were applied to an S-glass woven fabric (thickness: 100 μm) by impregnation, and the fabric was dried by heating at 140° C. for 3 minutes to obtain a prepreg having a resin composition solids content (including filler) of 48.8% by mass.

[0142] Two sheets of the obtained prepreg were stacked, and electrolytic copper foil (3EC-VLP, manufactured by Mitsui Mining & Smelting Co., Ltd.) having a thickness of 12 μm was placed on top and bottom, and a pressure of 30 kgf / cm was applied. 2 The laminate was then molded at 230° C. for 100 minutes to obtain a copper foil-clad laminate including an insulating layer having a thickness of 0.2 mm as a metal foil-clad laminate.

[0143] (Test Example 1: CTE (Coefficient of Linear Thermal Expansion)) After removing the copper foil on both sides of the metal foil-clad laminate (20 mm x 5 mm x 0.2 mm) obtained above by etching, the temperature was raised from 40 ° C to 340 ° C at a rate of 10 ° C per minute using a thermomechanical analyzer (manufactured by TA Instruments), and the coefficient of linear expansion in the plane direction from 60 ° C to 120 ° C was measured, and the obtained value was used as the evaluation value of the coefficient of linear thermal expansion (ppm / ° C). The measurement direction was the longitudinal direction (Warp) of the glass cloth of the laminate. The results are shown in Table 1.

[0144] (Test Example 2: Tg (glass transition temperature)) After the copper foils on both sides of the metal foil-clad laminate (20 mm × 5 mm × 0.2 mm) obtained above were removed by etching, the glass transition temperature (Tg) (unit: ° C.) was measured using a dynamic viscoelasticity measuring device (manufactured by TA Instruments) in accordance with JIS C6481. The results are shown in Table 1.

[0145] (Test Example 3: Desmear Resistance) After the copper foil on both sides of the metal foil-clad laminate (50 mm × 50 mm × 0.2 mm) obtained above was removed by etching, the laminate was immersed in a swelling solution, Swelling Dip Securigant P (Atotech Japan Co., Ltd.), at 80°C for 10 minutes, then in a roughening solution, Concentrate Compact CP (Atotech Japan Co., Ltd.), at 80°C for 5 minutes, and finally in a neutralizing solution, Reduction Conditioner Securigant P500 (Atotech Japan Co., Ltd.), at 45°C for 10 minutes. This treatment was repeated three times. The mass of the copper foil-clad laminate before and after treatment was measured, and the mass loss (unit: mass%) based on the sample mass before treatment was calculated. A smaller absolute value of the mass loss indicates better desmear resistance. The results are shown in Table 1.

[0146] (Test Example 4: Flame Resistance) After removing the copper foil on both sides of the metal foil-clad laminate (20 mm x 5 mm x 0.2 mm) obtained above by etching, a flame retardancy test was carried out in accordance with the UL94 vertical flame test method. The results are shown in Table 1. In Table 1, "average (seconds)" means the average burning time of the five test specimens, and "maximum (seconds)" means the maximum burning time of the five test specimens.

[0147]

[0148] From the above results, it was found that when a borate ester compound other than that of formula (1) is used in a resin composition containing a thermosetting compound and a phosphorus compound, the desired varnish-like resin composition cannot be obtained due to insolubility or gelation, whereas by using a borate ester compound of formula (1), the reactivity of the borate ester compound with the thermosetting compound can be suppressed, and the desired varnish-like resin composition can be obtained and excellent flame retardancy can be imparted.

[0149] When a borate ester compound other than that of formula (1) was used, the desired varnish-like resin composition could not be obtained due to gelation. Possible reasons for this include, for example, the possibility that boron functions as a Lewis acid catalyst, thereby accelerating the curing of the thermosetting compound, or the possibility that boron interacts with the polar group of the thermosetting compound through hydrogen bonding.

[0150] This application claims priority to a Japanese patent application (Patent Application No. 2024-130962) filed on August 7, 2024, the entire contents of which are deemed to be part of the disclosure of this application and are incorporated herein by reference.

Claims

1. A resin composition containing a thermosetting compound (A), a phosphorus compound (B), and a borate ester compound (C) represented by the following formula (1): (In formula (1), each R independently represents an alkyl group having 1 to 8 carbon atoms.) 2. The resin composition according to claim 1, wherein the thermosetting compound (A) contains at least one compound selected from the group consisting of maleimide compounds, epoxy compounds, and cyanate ester compounds.

3. The resin composition according to claim 1, wherein the phosphorus compound (B) is halogen-free.

4. The resin composition according to claim 1, wherein the phosphorus compound (B) comprises one or more compounds selected from the group consisting of phosphazenes, phosphates, phosphoric acid esters, phosphinates, phosphinic acid esters, phosphonates, and phosphonic acid esters.

5. The resin composition according to claim 1, wherein the content of the borate ester compound (C) is 0.5 to 10 parts by mass per 100 parts by mass of the thermosetting compound (A).

6. The resin composition according to claim 1, wherein the content of the borate ester compound (C) is 10 to 200 parts by mass per 100 parts by mass of the phosphorus compound (B).

7. The resin composition according to claim 1, further comprising an inorganic filler (D).

8. The resin composition according to claim 7, wherein the content of the inorganic filler (D) is 100 parts by mass or more per 100 parts by mass of the resin solid content in the resin composition.

9. The resin composition according to claim 1, further comprising an organic filler (E).

10. The resin composition according to claim 9, wherein the organic filler (E) contains silicone particles.

11. The resin composition according to claim 1, further comprising a silane coupling agent (F).

12. The resin composition according to claim 1, wherein the thermosetting compound (A) contains one or more compounds selected from the group consisting of maleimide compounds, epoxy compounds, and cyanate ester compounds; the phosphorus compound (B) contains one or more compounds selected from the group consisting of phosphazenes, phosphates, phosphoric acid esters, phosphinates, phosphinate esters, phosphonates, and phosphonate esters; and the content of the borate ester compound (C) is 0.5 to 10 parts by mass per 100 parts by mass of the thermosetting compound (A) and 10 to 200 parts by mass per 100 parts by mass of the phosphorus compound (B).

13. The resin composition according to claim 12, further comprising an inorganic filler (D), the content of said inorganic filler (D) being 100 parts by mass or more per 100 parts by mass of the resin solid content in the resin composition.

14. The resin composition according to any one of claims 1 to 13, which is used to form an insulating layer of a printed wiring board.

15. A prepreg comprising a substrate and the resin composition according to any one of claims 1 to 13 impregnated into or applied to the substrate.

16. A resin sheet comprising a support and a resin composition layer formed from the resin composition according to any one of claims 1 to 13 provided on the support.

17. A printed wiring board comprising an insulating layer containing a cured product formed by curing the resin composition according to any one of claims 1 to 13.

18. A semiconductor package comprising the printed wiring board according to claim 17 and a semiconductor element.

19. A semiconductor device comprising the printed wiring board according to claim 17.

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