Curable composition, prepreg, resin film, metal-clad laminate, printed circuit board, semiconductor package, and method for adjusting melt viscosity

Abstract

The present invention provides a curable composition with excellent thermal expansion resistance when used in prepreg applications, as well as prepregs, resin films, metal-clad laminates, printed circuit boards, semiconductor packages, and a method for adjusting melt viscosity. [Solution] The resin contains at least two compounds that have different structures from the compounds represented by general formula (1), and R is present in the resin. 1 , R 2 and R 3 At least one of them is a vinylbenzyl group, and R present in the resin 1 , R 2 and R 3 A curable composition comprising a resin (A) in which at least one of the members is an arylalkyl group other than a vinylbenzyl group, an azo radical polymerization initiator (B), and an imidazole compound (C).

Description

Technical Field

[0001] The present disclosure relates to a curable composition, a prepreg, a resin film, a metal-clad laminate, a printed wiring board, a semiconductor package, and a method for adjusting melt viscosity.

Background Art

[0002] Metal-clad laminates typified by copper-clad laminates, prepregs that can be used for metal-clad laminates, semiconductor packages using metal-clad laminates, etc. are used in various electronic devices such as mobile communication devices such as smartphones, their base station devices, servers, routers, network infrastructure devices such as large servers, large computers, personal computers, and industrial computers. They are also used in electronic devices mounted on home appliances, automobiles, etc. Among them, electronic communication devices have an increasing demand for processing huge amounts of data at high speed due to the spread of 5G.

[0003] In electronic devices, when processing huge amounts of data at high speed, a substrate material with low transmission loss in the high-frequency region is required. Resins with low dielectric constant and low dielectric tangent are used for the substrate material, and a substrate with low transmission loss is provided. However, due to the development of communication technologies in recent years, the development of resins with even lower dielectric constant and lower dielectric tangent is required.

[0004] Patent Document 1 discloses a curable vinylbenzyl compound that can provide a cured product excellent in low dielectric constant, low dielectric tangent, high heat resistance, and low water absorption, and a compound having an indene ring structure into which a vinylbenzyl group is introduced.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] One object of the present disclosure is to provide a curable composition, a prepreg, a resin film, a metal-clad laminate, a printed wiring board, a semiconductor package, and a method for adjusting melt viscosity, which are excellent in heat expansion resistance when used for prepreg applications.

Means for Solving the Problems

[0007] The present disclosure includes the following embodiments. The present disclosure is not limited to the following embodiments. One embodiment relates to a curable composition containing at least two compounds having different structures among the compounds represented by the following general formula (1), wherein at least one of R 1 , R 2 and R 3 present in the resin is a vinylbenzyl group, and at least one of R 1 , R 2 and R 3 present in the resin is an arylalkyl group other than a vinylbenzyl group, an azo radical polymerization initiator (B), and an imidazole compound (C).

[0008]

Chemical formula

[0009] [In general formula (1), R 1 , R 2 and R 3 are each independently a hydrogen atom, a vinylbenzyl group, or an arylalkyl group other than a vinylbenzyl group. R 4 is a hydrogen atom, a monovalent organic group, or a halogen atom, and all four R 4 may be different from each other, and two or more of the four R 4 may be the same as each other.]

Advantages of the Invention

[0010] This disclosure provides a curable composition, prepreg, resin film, metal-clad laminate, printed circuit board, semiconductor package, and a method for adjusting the melt viscosity, all of which exhibit excellent thermal expansion resistance when used in prepreg applications. [Modes for carrying out the invention]

[0011] The embodiments of the present invention will be described in detail below. The present invention is not limited to the embodiments described below.

[0012] In this disclosure, numerical ranges indicated using "~" represent a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described stepwise in this disclosure, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range. Furthermore, the upper or lower limits of numerical ranges described in this disclosure may be replaced with the values ​​shown in the examples. In this disclosure, each component may contain one or more of the applicable substances unless otherwise specified. In this disclosure, the content of each component in the curable composition means the total amount of multiple substances present in the curable composition if there are multiple substances corresponding to each component, unless otherwise specified.

[0013] In this disclosure, unless otherwise specified, weight-average molecular weight (Mw) and number-average molecular weight (Mn) are values ​​measured by the following procedure. The weight-average molecular weight and number-average molecular weight are calculated from a calibration curve using standard polystyrene by gel permeation chromatography (GPC). The calibration curve is approximated by a cubic equation using standard polystyrene: TSKstandard POLYSTYRENE (Type; A-2500, A-5000, F-20, F-80) (manufactured by Tosoh Corporation, trade name). The GPC conditions are shown below.

[0014] Equipment: High-speed GPC system "HLC-8320GPC" (Tosoh Corporation, product name) Detector: UV-8320 ultraviolet absorption detector (Tosoh Corporation, product name) Columns: Guard column; TSKgel guardcolumn Super(HZ)-M+, Column; TSKgel SuperMultipore HZ-M (2 pieces), Reference column; TSKgel SuperH-RC (2 pieces) (All products are from Tosoh Corporation) Column sizes: 4.6 x 20 mm (guard column), 4.6 x 150 mm (column), 6.0 x 150 mm (reference column) Eluent: Tetrahydrofuran Sample concentration: 10 mg / 1 mL Injection volume: 20 μL or 2 μL Flow rate: 0.35mL / min Measurement temperature: 40℃

[0015] A curable composition according to one embodiment of the present disclosure contains at least two compounds represented by the following general formula (1) that have different structures from each other, and R present in the resin 1 , R 2 and R 3 At least one of them is a vinylbenzyl group, and R present in the resin 1 , R 2 and R 3 The curable composition comprises a resin (A) in which at least one of the elements is an arylalkyl group other than a vinylbenzyl group, an azo radical polymerization initiator (B), and an imidazole compound (C).

[0016] [ka]

[0017] [In general formula (1), R 1 , R 2 and R 3 Each of these is independently a hydrogen atom, a vinylbenzyl group, or an arylalkyl group other than a vinylbenzyl group. 4 is a hydrogen atom, a monovalent organic group, or a halogen atom, and has four R 4 All of them may be different from each other, and there are four R's.4 Two or more of these may be identical.

[0018] In one embodiment, the curable composition contains a resin (A), and by including an azo radical polymerization initiator (B) and an imidazole compound (C), the minimum melt viscosity measured under heating conditions is moderately increased. As a result, the curable composition remains without gaps in the fibrous substrate during prepreg manufacturing, and the impregnation and adhesion of the curable composition to the fibrous substrate are improved. Furthermore, excessive flow of the resin is suppressed when the prepreg is heat-cured, so the amount of resin in the cured prepreg can be maintained as designed, and dimensional accuracy such as thickness can be improved. As a result, compared to cases where the azo radical polymerization initiator (B) and imidazole compound (C) are not used in combination, the cured prepreg exhibits superior thermal expansion resistance. Moreover, superior effects are expected in dielectric properties, flame retardancy, metal foil adhesion, glass transition temperature, heat resistance evaluated by solder bath tests, etc. In addition, because the curable composition remains completely within the fibrous substrate during the manufacturing of the prepreg, deviations from design values ​​such as the resin content and thickness of the prepreg are reduced, resulting in effects such as easier acquisition of the performance expected in the design and improved yield in industrial production. It should be noted that the above is merely one consideration in this disclosure, and the mechanism of effect is not limited to this. Furthermore, the effects of this disclosure can also be expected in cured products such as resin films, metal-clad laminates, printed circuit boards, semiconductor packages, etc., obtained using the curable composition of one embodiment, along with the prepreg.

[0019] Resin (A) contains at least two compounds with different structures from the compounds represented by the following general formula (1), and R present in the resin 1 , R 2 and R 3 At least one of them is a vinylbenzyl group, and R present in the resin 1 , R 2 and R 3 At least one of them is an arylalkyl group other than a vinylbenzyl group.

[0020] [ka]

[0021] [In general formula (1), R 1 , R 2 and R 3 Each of these is independently a hydrogen atom, a vinylbenzyl group, or an arylalkyl group other than a vinylbenzyl group. 1 , R 2 and R 3 At least one of them is a vinylbenzyl group, and at least one is an arylalkyl group other than a vinylbenzyl group. 4 is a hydrogen atom, a monovalent organic group, or a halogen atom, and has four R 4 All of them may be different from each other, and there are four R's. 4 Two or more of these may be identical.

[0022] The vinylbenzyl groups contained in resin (A) may be o-vinylbenzyl groups, m-vinylbenzyl groups, or p-vinylbenzyl groups. Among these, p-vinylbenzyl groups are preferred because they can keep the dielectric loss tangent in the cured product lower. The proportion of p-vinylbenzyl groups in the total vinylbenzyl groups contained in resin (A) may be 10 mol% or more, 20 mol% or more, or 30 mol% or more. It may also be 100 mol% or less, 80 mol% or less, or 70 mol% or less. The proportion of p-vinylbenzyl groups in the total vinylbenzyl groups contained in resin (A) may be in the range of 10 to 100 mol%. If the proportion of p-vinylbenzyl groups is less than 100 mol%, the remaining vinylbenzyl groups may be m-vinylbenzyl groups.

[0023] Regarding arylalkyl groups other than vinylbenzyl groups contained in resin (A) (hereinafter sometimes referred to as "arylalkyl groups"), the number of carbon atoms in the alkyl group within the arylalkyl group is not particularly limited, but may be in the range of 1 to 6, for example. Furthermore, the alkyl group may be linear or have a branched structure. Specific examples of alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, n-pentyl group, isopentyl group, neopentyl group, t-pentyl group, n-hexyl group, isohexyl group, etc. Among these, it is preferable that the alkyl group in the arylalkyl group has a relatively small number of carbon atoms, as this allows for a lower dielectric loss tangent in the cured product. For example, the alkyl group in the arylalkyl group may be a methyl group or an ethyl group, or it may be a methyl group.

[0024] The aryl group in the arylalkyl group is not particularly limited as long as it is not a styryl group, and examples include a phenyl group, a naphthyl group, and structural parts having one or more substituents on their aromatic rings. Substituents on the aromatic ring include, for example, halogen atoms such as fluorine, chlorine, bromine, or iodine; alkyl groups with 1 to 6 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, and isohexyl; alkoxy groups represented as RO- where R is one of the aforementioned alkyl groups; polymerizable unsaturated bond-containing groups such as vinyl, vinyloxy, allyl, allyloxy, (meth)acryloyl, and (meth)acryloyloxy groups; aryl groups such as phenyl, tolyl, xylyl, mesityl, and naphthyl groups; and aryloxy groups such as phenyloxy, tolyloxy, xylyloxy, mesityloxy, and naphthyloxy groups.

[0025] The arylalkyl group may not have polymerizable unsaturated bonds. The aryl group in the arylalkyl group may be a phenyl group, a naphthyl group, and have 1 to 3 alkyl groups with 1 to 3 carbon atoms on their aromatic rings.

[0026] R in general formula (1) 4 R is a hydrogen atom, a monovalent organic group, or a halogen atom. Examples of monovalent organic groups include alkyl groups with 1 to 6 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, n-pentyl group, isopentyl group, neopentyl group, t-pentyl group, n-hexyl group, and isohexyl group; alkoxy groups represented as RO- where R is one of the aforementioned alkyl groups; polymerizable unsaturated bond-containing groups such as vinyl group, vinyloxy group, allyl group, allyloxy group, (meth)acryloyl group, and (meth)acryloyloxy group; aryl groups such as phenyl group, tolyl group, xylyl group, mesityl group, and naphthyl group; and aryloxy groups such as phenyloxy group, tolyloxy group, xyloxy group, mesityloxy group, and naphthyloxy group. Examples of halogen atoms include fluorine, chlorine, bromine, or iodine. 4 All of them may be hydrogen atoms.

[0027] In resin (A), R present in the resin 1 , R 2 and R 3 At least one of them is a vinylbenzyl group, and at least one is an arylalkyl group. Resin (A) is R 1 , R 2 and R 3 A compound in which one of the atoms is a vinylbenzyl group, one is an arylalkyl group, and one is a hydrogen atom, R 1 , R 2 and R 3 A compound in which two of the groups are vinylbenzyl groups and one is an arylalkyl group, R 1 , R 2 and R 3A compound in which one of the groups is a vinylbenzyl group and the other two are arylalkyl groups, R 1 , R 2 and R 3 A compound in which 1 to 3 of the atoms are vinylbenzyl groups and the others are hydrogen atoms, R 1 , R 2 and R 3 A compound in which 1 to 3 of the atoms are arylalkyl groups and the others are hydrogen atoms, R 1 , R 2 and R 3 The compound may contain multiple compounds selected from the group consisting of compounds in which all atoms are hydrogen atoms. In a compound having multiple arylalkyl groups in one molecule, the arylalkyl groups may all be different, or some or all of them may be the same.

[0028] In resin (A), the average of the total number of vinylbenzyl groups and arylalkyl groups in one molecule is preferably 1.5 or higher, more preferably 1.8 or higher, and particularly preferably 2.0 or higher, as this results in excellent curability. It may also be 3.0 or lower, 2.8 or lower, or 2.5 or lower. The average of the total number of vinylbenzyl groups and arylalkyl groups in one molecule may be in the range of 1.5 to 3.0.

[0029] Furthermore, the ratio of vinylbenzyl groups to the total number of vinylbenzyl groups and arylalkyl groups present in resin (A) may be 30 mol% or more, 60 mol% or more, or 85 mol% or more. It may also be 99 mol% or less, 95 mol% or less, or 80 mol% or less. The ratio of vinylbenzyl groups to the total number of vinylbenzyl groups and arylalkyl groups may be in the range of 30 to 99 mol%.

[0030] Resin (A) is a compound identified by its molecular structure, and its manufacturing method is not particularly limited. One example of a method for producing resin (A) is to react indene, styrene having a methyl halide group, and an aromatic compound having an alkyl halide corresponding to an arylalkyl group in the presence of a basic compound.

[0031] Examples of styrenes having a methyl halide group include o-chloromethylstyrene, m-chloromethylstyrene, and p-chloromethylstyrene. These may be used individually or in combination of two or more. Examples of aromatic compounds having an alkyl halide include α-chlorotoluene, α-chloroxylene, and 1-(chloromethyl)naphthalene. These may be used individually or in combination of two or more.

[0032] The ratio of styrene having a methyl halide group to the total number of moles of styrene having a methyl halide group and aromatic compounds having an alkyl halide group may be 30 mol% or more, 60 mol% or more, or 85 mol% or more. Alternatively, it may be 99 mol% or less, 95 mol% or less, or 80 mol% or less. The ratio of styrene having a methyl halide group to the total number of moles of styrene having a methyl halide group and aromatic compounds having an alkyl halide group may be in the range of 30 to 99 mol%.

[0033] The total number of moles of styrene having a methyl halide group and an aromatic compound having an alkyl halide per mole of indene may be 1.5 moles or more, 1.8 moles or more, or 2.0 moles or more. It may also be 3.0 moles or less, 2.8 moles or less, or 2.5 moles or less. The total number of moles of styrene having a methyl halide group and an aromatic compound having an alkyl halide per mole of indene may be in the range of 1.5 to 3.0 moles.

[0034] Examples of basic compounds include alkali metal hydroxides and alkali metal alkoxides. These may be used individually or in combination of two or more.

[0035] A phase-transfer catalyst may be used in the above reaction. Examples of phase transfer catalysts include quaternary ammonium salts such as tetra-n-butylammonium chloride, tetra-n-butylammonium bromide (tetra-n-butylammonium bromide), tetraethylammonium chloride, tetraethylammonium bromide, tetrapropylammonium chloride, tetrapropylammonium bromide, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltributylammonium chloride, benzyltributylammonium bromide, benzyldimethyltetradecylammonium chloride, tricaprylmethylammonium chloride, tetradecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, trioctylmethylammonium chloride, and tetra-n-butylammonium bisulfate; and quaternary phosphonium salts such as tetra-n-butylphosphonium chloride, tetra-n-butylphosphonium bromide, tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, benzyltriphenylphosphonium chloride, and benzyltriphenylphosphonium bromide. These may be used individually or in combination of two or more types.

[0036] The above reaction may be carried out, for example, under heating and stirring conditions. The heating temperature may be around 50 to 100°C. The above reaction can also be carried out by solution polymerization. The solvent used is not particularly limited as long as it can dissolve the reaction raw materials and has a boiling point above the reaction temperature, but examples include aromatic hydrocarbon solvents such as toluene, xylene, and mesitylene. These may be used individually or in combination of two or more.

[0037] Polymerization inhibitors may be used in the reaction system as needed. Examples of polymerization inhibitors include hydroquinone, methylhydroquinone, t-butylhydroquinone, 2,6-di-t-butylhydroquinone, 2,5-di-t-butylhydroquinone, hydroquinone monomethyl ether, 1,4-benzoquinone, 2-t-butyl-1,4-benzoquinone, 2-t-butylphenol, 2,4-di-t-butylphenol, 2,6-di-t-butylphenol, cresol, catechol, 4-t-butylcatechol, pyrogallol, and 4 Examples include methoxyphenol, thiodiphenylamine, phenothiazine, 3,7-dioctylphenothiazine, 3,7-dicumylphenothiazine, 2,2,6,6-tetramethylpiperidine-1-oxyl, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl, and bis(2,2,6,6-tetramethyl-1-piperidinyloxy-4-yl) sebacate. These may be used individually or in combination of two or more.

[0038] The product obtained from the above reaction may be purified by known methods such as concentration, reprecipitation, and washing, if necessary.

[0039] The curable composition may contain polymerizable group-containing compounds other than resin (A). Examples of polymerizable group-containing compounds other than resin (A) include, for example, a prepolymer (D) obtained by polymerizing some of the vinyl groups in resin (A), a compound having a maleimide group, a polyarylene ether compound having a polymerizable group, an aromatic compound having a vinyl group, and triallyl isocyanurate.

[0040] With respect to prepolymer (D), in this disclosure, prepolymer refers to a polymer in which some of the polymerizable groups in the raw material remain without undergoing polymerization, and which has curability due to the remaining polymerizable groups.

[0041] The prepolymer (D) may be prepared by combining resin (A) with other reaction materials other than resin (A). The proportion of resin (A) in the total reaction materials of prepolymer (D) may be 50 mol% or more, 80 mol% or more, or 100 mol%.

[0042] The method for producing the prepolymer (D) is not particularly limited and can be produced by polymerizing reaction materials containing resin (A) in a general manner. One example is radical polymerization. The polymerization initiator used in radical polymerization is not particularly limited and known ones such as azo polymerization initiators and organic peroxide polymerization initiators can be used. The polymerization reaction may be carried out in a solvent. Examples of solvents that can be used include toluene and xylene. These may be used individually or in combination of two or more.

[0043] The weight-average molecular weight (Mw) of prepolymer (D) is not particularly limited, but may be 1,000 or more, 2,000 or more, or 3,000 or more, from the viewpoint of ease of manufacture and ease of handling of the curable resin material. It may also be 15,000 or less, 10,000 or less, or 8,000 or less. The weight-average molecular weight (Mw) of prepolymer (A1-2) may be in the range of 1,000 to 15,000.

[0044] Examples of compounds having a maleimide group include bismaleimide compounds and maleimide resins.

[0045] Specific examples of bismaleimide compounds include, for example, N,N'-ethylenebismaleimide, N,N'-hexamethylenebismaleimide, N,N'-(1,3-phenylene)bismaleimide, N,N'-[1,3-(2-methylphenylene)]bismaleimide, N,N'-[1,3-(4-methylphenylene)]bismaleimide, N,N'-(1,4-phenylene)bismaleimide, bis(4-maleimidophenyl)methane, bis(3-methyl-4-maleimidophenyl)methane, and 3,3'-dimethyl-5,5'-die Tyl-4,4'-diphenylmethanebismaleimide, bis(4-maleimidophenyl) ether, bis(4-maleimidophenyl) sulfone, bis(4-maleimidophenyl) sulfide, bis(4-maleimidophenyl) ketone, bis(4-maleimidocyclohexyl)methane, 1,4-bis(4-maleimidophenyl)cyclohexane, 1,4-bis(maleimidomethyl)cyclohexane, 1,4-bis(maleimidomethyl)benzene, 1,3-bis(4-maleimidophenoxy)benzene, 1,3-bis(3- Maleimidophenoxy)benzene, bis[4-(3-maleimidophenoxy)phenyl]methane, bis[4-(4-maleimidophenoxy)phenyl]methane, 1,1-bis[4-(3-maleimidophenoxy)phenyl]ethane, 1,1-bis[4-(4-maleimidophenoxy)phenyl]ethane, 1,2-bis[4-(3-maleimidophenoxy)phenyl]ethane, 1,2-bis[4-(4-maleimidophenoxy)phenyl]ethane, 2,2-bis[4-(3-maleimidophenoxy)phenyl]propane , 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, 2,2-bis[4-(3-maleimidophenoxy)phenyl]butane, 2,2-bis[4-(4-maleimidophenoxy)phenyl]butane, 2,2-bis[4-(3-maleimidophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[4-(4-maleimidophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 4,4-bis(3-maleimidophenoxy)biphenyl, 4,4-Bis(4-maleimidophenoxy)biphenyl, bis[4-(3-maleimidophenoxy)phenyl]ketone, bis[4-(4-maleimidophenoxy)phenyl]ketone, bis(4-maleimidophenoxy)disulfide, bis[4-(3-maleimidophenoxy)phenyl]sulfide, bis[4-(4-maleimidophenoxy)phenyl]sulfide, bis[4-(3-maleimidophenoxy)phenyl ]sulfoxide, bis[4-(4-maleimidophenoxy)phenyl]sulfoxide, bis[4-(3-maleimidophenoxy)phenyl]sulfone, bis[4-(4-maleimidophenoxy)phenyl]sulfone, bis[4-(3-maleimidophenoxy)phenyl]ether, bis[4-(4-maleimidophenoxy)phenyl]ether, 1,4-bis[4-(4-maleimidophenoxy)-α,α-dimethic Rubenzyl]benzene, 1,3-bis[4-(4-maleimidophenoxy)-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(3-maleimidophenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(3-maleimidophenoxy)-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(4-maleimidophenoxy)-3,5-dimethyl-α,α-dimethylbenzyl]benzene Examples include 1,3-bis[4-(4-maleimidophenoxy)-3,5-dimethyl-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(3-maleimidophenoxy)-3,5-dimethyl-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(3-maleimidophenoxy)-3,5-dimethyl-α,α-dimethylbenzyl]benzene, and aromatic bismaleimide compounds having an indane skeleton.

[0046] Specific examples of maleimide resins include, for example, polyphenylmethane maleimide, maleimide resins having an indan skeleton, and biphenyl aralkyl type maleimide resins.

[0047] Maleimide resins having an indan skeleton include, for example, those represented by the following general formula (2). [ka]

[0048] [R in general formula (2) 5 [where a is a hydrogen atom or a methyl group, and a is an integer greater than or equal to 1.]

[0049] Examples of biphenylaralkyl-type maleimide resins include those represented by the following general formula (3).

[0050] [ka]

[0051] [In general formula (3), b is an integer greater than or equal to 1.]

[0052] Regarding polyarylene ether compounds having polymerizable groups, the arylene group is not particularly limited and examples include phenylene groups, naphthylene groups, and structures in which one or more alkyl groups, alkyloxy groups, halogen atoms, etc., are substituted on the aromatic carbons thereof. The polymerizable group may be included as, for example, a vinyl group, a vinyloxy group, an allyl group, an allyloxy group, a (meth)acryloyl group, a (meth)acryloyloxy group, a vinylbenzyl group, a vinylbenzyloxy group, etc. Polyarylene ether compounds having polymerizable groups may have structural parts other than the polyarylene ether structure. Specifically, they may have acrylic polymerization sites, (poly)urethane sites, (poly)ester sites, etc., in the molecular chain. The number of polymerizable groups in one molecule of a polyarylene ether compound is not particularly limited, nor is the substitution position of the polymerizable groups particularly limited. For example, a polyarylene ether compound may have polymerizable groups at the molecular end, or it may have polymerizable groups at both ends.

[0053] Specific examples of polyarylene ether compounds having polymerizable groups include, for example, resins represented by the following general formula (4).

[0054] [ka]

[0055] [In general formula (4), R 6 Each of these is independently a hydrogen atom or a methyl group. 7 [x] is one of the following: vinylbenzyl group, acryloyl group, or methacryloyl group. c and d are integers greater than or equal to 1. X is a divalent organic group.

[0056] In general formula (4), X is a divalent organic group, and its specific structure is not particularly limited, but examples include hydrocarbon groups with 1 to 6 carbon atoms, halogenated hydrocarbon groups, oxygen atoms, sulfur atoms, carbonyl groups, sulfonyl groups, etc.

[0057] The molecular weight of the polyarylene ether compound having polymerizable groups is not particularly limited, but for example, the number average molecular weight (Mn) may be in the range of 1,000 to 5,000.

[0058] Aromatic compounds containing a vinyl group include, for example, styrene, divinylbenzene, and 1,2-bis(4-vinylphenyl)ethane.

[0059] The proportion of resin (A) in the polymerizable group-containing compound is not particularly limited, but it may be 20% by mass or more, or 30% by mass or more, in which the effect of using the initiator (B) and compound (C) in combination becomes more pronounced. Furthermore, it may be 50% by mass or more, 80% by mass or more, or 100% by mass. The upper limit is not particularly limited, but for example, it may be 80% by mass or less, 60% by mass or less, or 50% by mass or less. The proportion of resin (A) in the polymerizable group-containing compound may be in the range of 20 to 100% by mass.

[0060] The curable composition of one embodiment may contain curable compounds other than polymerizable group-containing compounds. Examples of curable compounds other than polymerizable group-containing compounds include epoxy resins, phenolic resins, cyanate resins, benzoxazine resins, oxetane resins, amino resins, silicone resins, triazine resins, melamine resins, and the like. These may be used individually or in combination of two or more types.

[0061] In a curable composition, the proportion of polymerizable group-containing compounds in the curing components is not particularly limited, but it is preferably 50% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more, in that the effect of using the initiator (B) and compound (C) in combination becomes more pronounced. The proportion of polymerizable group-containing compounds in the curable components may further be 95% by mass or more, or 100% by mass. In addition, the content of curable compounds other than polymerizable group-containing compounds in the curable components may be 0 to 10% by mass, 0 to 5% by mass, or 0 to 2% by mass, and may be substantially not included in the curable composition. Note that the curable components refer to polymerizable group-containing compounds and curable compounds other than polymerizable group-containing compounds.

[0062] Initiator (B) can be any compound commonly known as an azo radical polymerization initiator. Initiator (B) may be used alone or in combination of two or more. Specific examples of initiator (B) include, for example, 2,2'-azobis(2,4,4-trimethylpentane), dimethyl-2,2'-azobis(2-methylpropionate), 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], 1,1'-azobis(cyclohexane-1-carbonitride), and dimethyl-1,1'-azobis(1-cyclohexanecarboxylate). Examples include ), 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylpropanenitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 4,4'-azobis(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl4-cyanopentanoate), etc.

[0063] The content of the initiator (B) in the curable composition is adjusted as appropriate according to the desired curing rate of the curable composition, but in order to make the effect of using initiator (B) and compound (C) in combination more pronounced, it is preferably 0.05 parts by mass or more, preferably 0.1 parts by mass or more, and more preferably 0.15 parts by mass or more, per 100 parts by mass of resin (A). It may also be 2 parts by mass, 1.5 parts by mass or less, or 1 part by mass or less. The amount of initiator (B) added per 100 parts by mass of resin (A) may be in the range of 0.05 to 2 parts by mass.

[0064] Furthermore, the content of initiator (B) may be 0.05% by mass or more, 0.1% by mass or more, or 0.15% by mass or more, based on the total mass of polymerizable group-containing compounds contained in the curable composition. The upper limit may be 1% by mass or less, 0.5% by mass or less, or 0.3% by mass or less. The content of initiator (B) may be in the range of 0.05 to 1% by mass, based on the total mass of polymerizable group-containing compounds contained in the curable composition.

[0065] The curable composition may use other polymerization initiators (B') in addition to initiator (B). One type of other polymerization initiator (B') may be used alone, or two or more types may be used in combination. Examples of other initiators (B') include organic peroxide-based polymerization initiators. Examples of organic peroxide-based polymerization initiators include dicumyl peroxide, dibenzoyl peroxide, 2-butanone peroxide, t-butyl perbenzoate, di-t-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexine-3, α,α'-di(t-butylperoxy)diisopropylbenzene, and t-butyl hydroperoxide. The ratio of initiator (B) to the total mass of initiators may be 80% by mass or more, 90% by mass or more, or 100% by mass.

[0066] Compound (C) can be any commonly known compound. Compound (C) may be used alone or in combination of two or more types. Specific examples of compound (C) include, for example, imidazole compounds such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-6-4′,5′-dihydroxymethylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, and 2,4-diamino-6-[2-(2-methyl-1-imidazolyl)ethyl]-1,3,5-triazine; and isocyanate-masquimidazole, which is an addition reaction product of an isocyanate compound and an imidazole compound.

[0067] Specific examples of isocyanate maskimidazoles include, for example, the compounds represented by the following general formula (5).

[0068] [ka]

[0069] [In general formula (5), R 8 , R 9 , R 10 and R 11 Each of these is independently a hydrogen atom, an aliphatic hydrocarbon group with 1 to 20 carbon atoms, or a phenyl group. Y is an alkylene group or an aromatic hydrocarbon group.

[0070] R in general formula (5) 8 , R 9 , R 10 and R 11Each of these is independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, or a phenyl group. The aliphatic hydrocarbon group having 1 to 20 carbon atoms may be linear, branched, or cyclic. It may also have some unsaturated bonds. Specific examples include linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, hexadecyl, and eicosyl groups; branched alkyl groups such as isopropyl, isobutyl, isopentyl, neopentyl, 2-ethylhexyl, tert-butyl, tert-pentyl, and isopentadecyl groups; and cyclopropyl, cyclo Examples include cyclic alkyl groups such as lopentyl, cyclohexyl, cycloheptyl, cyclooctyl, tricyclodecyl, norbornyl, and adamantyl; alkenyl groups such as vinyl, 1-propenyl, 2-propenyl, 2-butenyl, 1-butenyl, 1-hexenyl, and 2-dodecenyl; and alkynyl groups such as ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 3-hexynyl, and 2-dodecynyl. The number of carbon atoms in the aliphatic hydrocarbon group may be in the range of 1 to 12, 1 to 8, 1 to 4, or 1 or 2.

[0071] In general formula (5), Y is an alkylene group or an aromatic hydrocarbon group. The number of carbon atoms in the alkylene group is not limited to, for example, 1 to 20. Specific examples of alkylene groups include, for example, linear alkylene groups such as methylene group, ethylene group, n-propylene group, n-butylene group, n-pentylene group, n-hexylene group, n-heptylene group, n-octylene group, n-nonylene group, n-decylene group, n-undecylene group, n-dodecylene group, tridecylene group, n-tetradecylene group, n-pentadecylene group, n-heptadecylene group, n-octadecylene group, n-nonadesilene group, n-icosilene group, etc.; isopropylene group, isobutylene group, sec-butylene group, tert-butylene group, isopentylene group, neopentylene group, tert-pentylene group, isohexylene group, sec-hexylene group, tert-hex Examples include branched alkylene groups such as silene group, isoheptylene group, sec-heptylene group, tert-heptylene group, isooctylene group, sec-octylene group, tert-octylene group, isononylene group, sec-nonylene group, tert-nonylene group, isodecylene group, sec-decylene group, tert-decylene group, isododecylene group, sec-dodecylene group, tert-dodecylene group, tert-tetradecylene group, and tert-pentadecylene group; and cyclic alkylene groups such as cyclopropylene group, cyclobutylene group, cyclopentylene group, cyclohexylene group, cycloheptylene group, cyclooctylene group, cyclononylene group, and cyclodecylene group. The number of carbon atoms in the alkylene group may be in the range of 1 to 12, 1 to 8, or 1 to 6.

[0072] Examples of aromatic hydrocarbon groups include phenylene groups, biphenylene groups, terphenylene groups, naphthylene groups, anthracenylene groups, phenanthrylene groups, and structures having one or more substituents on these aromatic rings. Examples of substituents on the aromatic ring include the aforementioned aliphatic hydrocarbon groups having 1 to 20 carbon atoms.

[0073] Examples of commercially available products of compounds represented by general formula (6) include, for example, Daiichi Kogyo Seiyaku Co., Ltd.'s "G8009L" (where R is represented by general formula (5)). 8 and R 10 is a methyl group, R 9 and R 11 Examples include compounds in which Y is an ethyl group and Y is a butylene group.

[0074] Compound (C) may be isocyanate macimidazole. The proportion of isocyanate macimidazole to the total mass of compound (C) may be 50% by mass or more, 70% by mass or more, 90% by mass or more, or 100% by mass.

[0075] The content of compound (C) in the curable composition is adjusted as appropriate according to the desired performance of the curable composition, but in order to make the effect of using the initiator (B) and compound (C) in combination more pronounced, it is preferably 0.01 parts by mass or more, preferably 0.05 parts by mass or more, and more preferably 0.1 parts by mass or more, per 100 parts by mass of resin (A). It may also be 2 parts by mass, 1.5 parts by mass or less, or 1 part by mass or less. The amount of compound (C) added per 100 parts by mass of resin (A) may be in the range of 0.01 to 2 parts by mass.

[0076] Furthermore, the content of compound (C) may be 0.01% by mass or more, 0.1% by mass or more, or 0.15% by mass or more, based on the total mass of polymerizable group-containing compounds contained in the curable composition. The upper limit may be 1% by mass or less, 0.5% by mass or less, or 0.3% by mass or less. The content of compound (C) may be in the range of 0.01 to 1% by mass, based on the total mass of polymerizable group-containing compounds contained in the curable composition.

[0077] In the curable composition, the ratio of the content of initiator (B) and compound (C) is not particularly limited. However, in order to achieve a more pronounced effect by using both in combination, the ratio of compound (C) to the content of initiator (B) is preferably 20% by mass or more, more preferably 50% by mass or more, and particularly preferably 80% by mass or more. It is also preferable that it be 120% by mass or less. The ratio of compound (C) to the content of initiator (B) may be in the range of 20 to 120% by mass.

[0078] The curable composition may optionally contain other components besides the resin (A), initiator (B), and compound (C). Examples of other components include polymerizable group-containing compounds other than the resin (A) described above, curable compounds other than polymerizable group-containing compounds, and other initiators (B'), as well as elastomers, flame retardants, silane coupling agents, fillers, polymerization inhibitors, antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, pigments, colorants, lubricants, solvents, etc. Each of the other components may be used individually or in combination of two or more types.

[0079] Examples of elastomers include polyether-based elastomers, styrene-based elastomers, conjugated diene-based elastomers, urethane-based elastomers, polyester-based elastomers, polyamide-based elastomers, acrylic-based elastomers, and silicone-based elastomers. The elastomer content is not particularly limited, but may be 50% by mass or less, 20% by mass or less, 10% by mass or less, or 5% by mass or less, based on the total mass of polymerizable group-containing compounds in the curable composition. Furthermore, the curable composition may not contain elastomers at all.

[0080] Examples of flame retardants include phosphorus-based flame retardants, nitrogen-based flame retardants, silicone-based flame retardants, and inorganic flame retardants. The amount of flame retardant added is adjusted as appropriate depending on the type of flame retardant, the intended use of the curable composition, and the desired physical properties. For example, when using a phosphorus-based flame retardant, the amount may be adjusted by the phosphorus atom content in the curable composition. Specifically, the phosphorus atom content relative to the total mass of the resin components in the curable composition, i.e., the total mass of components other than the inorganic filler and solvent in the curable composition, may be in the range of 0.1 to 20% by mass.

[0081] Silane coupling agents can be various compounds that are generally known. Examples of silane coupling agents include epoxy group-containing silanes such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-n-(1,3-dimethylbutylidene)propylamine, and N-phenyl-3- Examples include amino group-containing silanes such as aminopropyltrimethoxysilane; cationic silanes such as 3-(trimethoxylyl)propyltetramethylammonium chloride; vinyl group-containing silanes such as vinyltrimethoxysilane and vinyltriethoxysilane; (meth)acryloyl group-containing silanes such as 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane; and mercapto group-containing silanes such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane.

[0082] The content of the silane coupling agent is not limited to the above, but may be in the range of 0.5 to 5% by mass relative to the total mass of polymerizable group-containing compounds in the curable composition.

[0083] Both organic and inorganic fillers can be used as fillers, but inorganic fillers are preferred. Examples of inorganic fillers include silica (SiO2), alumina (Al2O3), titanium oxide, barium titanate, strontium titanate, potassium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum hydroxide, aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, silicon nitride, boron nitride, aluminum borate, silicon carbide, mica, beryllia, clay, and talc. Among these, silica is preferred from the viewpoint of dielectric properties. The type of silica is not particularly limited and may be crystalline silica or amorphous silica, and may be natural silica or synthetic silica. The method of producing synthetic silica is also not particularly limited and may be wet silica such as colloidal silica, fumed silica (dry silica), or fused silica. The shape of the silica is also not particularly limited and may be spherical silica, crushed silica, solid silica, porous silica, or hollow silica. The filler may be used alone or in combination of two or more types. An example of a combination is the use of solid silica and hollow silica. The ratio of the two is not particularly limited, but for example, the ratio of hollow silica to the total mass of solid silica and hollow silica may be 1% by mass or more, 5% by mass or more, or 8% by mass or more. It may also be 50% by mass or less, 30% by mass or less, or 20% by mass or less. The ratio of hollow silica to the total mass of solid silica and hollow silica may be in the range of 1 to 50% by mass.

[0084] The shape and size of the filler are not particularly limited. The average particle diameter of the filler may be, for example, 0.01 to 20 μm, or 0.1 to 10 μm. Here, the average particle diameter of the filler is the particle diameter at the point corresponding to 50% of the cumulative value in the volume-based particle distribution obtained by laser diffraction scattering.

[0085] If the curable composition contains a filler, the amount of filler added may be in the range of 50 to 500 parts by mass per 100 parts by mass of the total resin components in the curable composition. The resin components in the curable composition refer to resin (A), polymerizable group-containing compounds other than resin (A), curable compounds other than polymerizable group-containing compounds, and elastomers.

[0086] The curable composition may be solvent-free or may contain a solvent. The solvent can adjust the viscosity of the curable composition and further improve its coating properties. Organic solvents are preferred as the solvent.

[0087] Examples of organic solvents include alcohol-based solvents such as ethanol, propanol, butanol, methyl cellosolve, ethylene glycol monobutyl ether, and propylene glycol monomethyl ether; ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether-based solvents such as tetrahydrofuran; aromatic hydrocarbon-based solvents such as toluene, xylene, and mesitylene; nitrogen-containing solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone; sulfur-containing solvents such as dimethyl sulfoxide; and ester-based solvents such as γ-butyrolactone.

[0088] If the curable composition contains a solvent, the solid content of the curable composition may be, for example, in the range of 30 to 95% by mass.

[0089] The method for producing the curable composition is not particularly limited. One example of a method for producing the curable composition is to add and mix a resin (A), an initiator (B), a compound (C), and any optional components as needed. When mixing, the resin (A), initiator (B), compound (C), and any optional components as needed may be mixed as is, or they may be dissolved or dispersed in a solvent before mixing. The mixing order of each component, temperature, time, and other conditions are not particularly limited and may be adjusted as appropriate according to the type of raw materials, production scale, production equipment, etc.

[0090] [Prepreg] According to one embodiment, a prepreg containing a curable composition or a semi-cured product of a curable composition can be provided. This prepreg can be formed, for example, using a curable composition and a fibrous substrate. With respect to the semi-cured product of a curable composition, in this disclosure, the B-stage state in JIS K 6800 (1985) can be cited as one indicator of the semi-cured state. The prepreg may contain, for example, a curable composition or a semi-cured product of a curable composition and a fibrous substrate such as a sheet-like fibrous substrate. In the prepreg, the curable composition may be in an uncured state, or it may be in a partially or entirely semi-cured state.

[0091] A prepreg can be obtained, for example, by impregnating a fibrous substrate with a curable composition and drying the fibrous substrate impregnated with the curable composition. Drying is preferably carried out at a temperature above which volatile components such as solvents that may be contained in the curable composition are removed, and may also be carried out at a temperature above which the curable components contained in the curable composition are partially cured, depending on the application. Furthermore, it is preferable that the drying is adjusted so that the thermosetting resin contained in the curable composition is not completely cured. From this viewpoint, the drying temperature may be, for example, 80 to 200°C, and the drying time may be, for example, 1 to 30 minutes, depending on the drying temperature, drying equipment, and its scale.

[0092] The fibrous base material may be woven, knitted, or nonwoven fabric. The fibrous base material may be provided in the form of chopped strand mats, rovings, etc. The fiber material may be either inorganic or organic. Examples of inorganic fibers include glass fibers and carbon fibers. Examples of glass fibers include E glass, NE glass, D glass, S glass, and Q glass. Examples of organic fibers include polyimide, polyester, and tetrafluoroethylene. The fibrous base material may use one of these fibers alone, or it may use two or more of these fibers in combination. From the viewpoint of dielectric properties and thermal expansion resistance, inorganic fibers are preferred for the fibrous base material, and glass fibers are more preferred.

[0093] The fibrous substrate can be appropriately selected depending on the application of the prepreg, but a sheet-like fibrous substrate is preferred. Examples of sheet-like fibrous substrates include various types of sheet-like fibrous substrates used in known laminates for electrical insulation materials. The thickness of the sheet-like fibrous substrate is not particularly limited, but for example, 0.01 to 0.1 mm is preferred. Here, the thickness is determined by measuring the thickness at five points at equal distances across the entire surface of the sheet-like fibrous substrate and taking the arithmetic mean of these five points.

[0094] [Resin film] According to one embodiment, a resin film comprising a curable composition or a semi-cured product of a curable composition can be provided. The resin film can be obtained, for example, by coating a material to be coated with the curable composition and drying or semi-curing it. Drying or semi-curing may be carried out in the same manner as the method for manufacturing the prepreg described above. After drying the resin film on the material to be coated, the product may be provided as a combination of the resin film and the material to be coated. For example, in this method, the resin film can be provided as a surface protective film, an interlayer insulating film, etc., in a printed circuit board. In another method, after drying the resin film on the material to be coated, the resin film may be peeled off the material to provide the resin film as a product.

[0095] The material to be coated may be either an inorganic or organic substrate, and examples include glass substrates, metal foils, metal plates and other metal substrates, plastic plates, plastic films and other plastic substrates, paper substrates, and even fibrous substrates as described in the prepreg section above. In order to peel the resin film from the material to be coated and provide it, a material to be coated that has a release layer formed on its surface may be used.

[0096] [Metal-clad laminate] According to one embodiment, a metal-clad laminate containing a cured product of a curable composition and a metal foil can be provided. With respect to the cured product, in this disclosure, the state of the C-stage according to JIS K 6800 (1985) can be cited as one indicator of the cured product.

[0097] In a metal-clad laminate, the cured product of the curable composition may be included as the cured product of the curable composition itself, or it may be included in the form of a prepreg. The metal-clad laminate may include a prepreg layer and a metal foil placed on at least one surface of the prepreg layer. The prepreg layer is the cured product of the prepreg described above, and may consist of a single prepreg or multiple prepregs laminated together. Furthermore, the metal-clad laminate may have the metal foil placed on one surface of the curable composition or the cured product of the prepreg, or it may have the metal foil placed on both surfaces of the curable composition or the cured product of the prepreg. The metal-clad laminate may be manufactured by placing the metal foil on at least one surface of a single sheet-like prepreg, or by laminating two or more sheet-like prepregs and placing the metal foil on at least one surface of the outermost layer of the laminate. The metal-clad laminate may be manufactured by laminating two or more sheet-like prepregs and placing the metal foil on both surfaces of this laminate.

[0098] The following describes a specific method for manufacturing metal-clad laminates, which involves placing metal foil on a laminate of two or more sheet-like prepregs.

[0099] First, two or more sheet-like prepregs are laminated to obtain a laminate. In this laminate, the two or more sheet-like prepregs may be identical, or they may be partially or completely different. In the laminate, it is sufficient that at least one of the two or more sheet-like prepregs is obtained using the curable composition according to one embodiment.

[0100] Next, a metal foil is placed on at least one surface of the laminate. The laminate with the metal foil is then heated and pressurized. This causes the sheet-like prepreg to harden, and a hardened prepreg product can be obtained. Adjacent sheet-like prepregs can also be bonded together. The heating and pressurizing conditions are not particularly limited, but for example, the temperature can be 100 to 300°C, the time 10 to 300 minutes, and the pressure 0.5 to 50 MPa. After heating and pressurizing, reheating may be performed to further harden the prepreg. In this case, the reheating temperature can be 100 to 300°C. As for the pressurizing method, for example, an autoclave molding machine, a multi-stage press machine, a multi-stage vacuum press machine, a continuous molding machine, etc., can be used.

[0101] The metal used for the metal foil is not particularly limited and can include, for example, copper, nickel, aluminum, gold, silver, platinum, molybdenum, ruthenium, tungsten, iron, titanium, chromium, or alloys containing two or more of these metal elements. Industrially, it is preferable to use single metals such as copper, nickel, or aluminum. By using copper as the metal foil, a copper-clad laminate can be provided.

[0102] [Printed wiring board] According to one embodiment, a printed circuit board containing a cured product of a curable composition can be provided. In the printed circuit board, the cured product of the curable composition may be included as the cured product of the curable composition itself, or it may be included in the form of a prepreg. The printed circuit board can be manufactured using a curable composition, a prepreg, a metal-clad laminate, or a combination thereof. For example, a printed circuit board can be provided by forming wiring using a metal-clad laminate by a known method. Details of the prepreg and metal-clad laminate are as described above. The printed circuit board may be either a single-layer printed circuit board or a multi-layer printed circuit board.

[0103] [Semiconductor Packages] According to one embodiment, a semiconductor package can be provided that includes a printed circuit board and a semiconductor element. More specifically, for example, a semiconductor package can be provided that includes a printed circuit board containing a cured product of a curable composition and a semiconductor element. The semiconductor package can be manufactured, for example, by mounting a semiconductor element, memory, etc., on a printed circuit board by a known method.

[0104] Examples of embodiments are given below. The present invention is not limited to the following embodiments. <1> The resin contains at least two compounds represented by the following general formula (1) that have different structures from each other, and R is present in the resin. 1 , R 2 and R 3 At least one of them is a vinylbenzyl group, and R present in the resin 1 , R 2 and R 3 A curable composition comprising a resin (A) in which at least one of the members is an arylalkyl group other than a vinylbenzyl group, an azo radical polymerization initiator (B), and an imidazole compound (C).

[0105] [ka]

[0106] [In general formula (1), R 1 , R 2 and R 3 Each of these is independently a hydrogen atom, a vinylbenzyl group, or an arylalkyl group other than a vinylbenzyl group. 4 is a hydrogen atom, a monovalent organic group, or a halogen atom, and has four R 4 All of them may be different from each other, and there are four R's. 4 Two or more of these may be identical.

[0107] <2> The content of the azo radical polymerization initiator (B) is in the range of 0.05 to 1% by mass per 100 parts by mass of the resin (A), <1> The curable composition described above.

[0108] <3> The content of the imidazole compound (C) is in the range of 0.01 to 1% by mass per 100 parts by mass of the resin (A), <1> or <2> The curable composition described above.

[0109] <4> The ratio of the content of the imidazole compound (C) to the content of the azo radical polymerization initiator (B) is in the range of 20 to 120% by mass. <1> ~ <3> A curable composition as described in any one of the following.

[0110] <5> The arylalkyl groups other than vinylbenzyl groups contained in the resin (A) do not have polymerizable unsaturated bonds. <1> ~ <4> A curable composition as described in any one of the following.

[0111] <6> The aforementioned <1> ~ <5> A prepreg comprising a curable composition described in any one of the above or a semi-cured product of the curable composition.

[0112] <7> The aforementioned <1> ~ <5> A resin film comprising a curable composition described in any one of the above or a semi-cured product of the curable composition.

[0113] <8> The aforementioned <1> ~ <5> A metal-clad laminate comprising a cured product of any one of the curable compositions described in the above, and a metal foil.

[0114] <9> The aforementioned <1> ~ <5> A printed circuit board comprising a cured product of any one of the curable compositions described in the following.

[0115] <10> The aforementioned <9> A semiconductor package comprising a printed circuit board and semiconductor elements as described above.

[0116] <11> A semiconductor element and the encapsulating the semiconductor element <1> ~ <5> A semiconductor package comprising a cured product of any one of the curable compositions described in the following.

[0117] <12> The aforementioned <1> ~ <5> A printed circuit board comprising at least one of a surface protective film and an interlayer insulating film formed by a curable composition described in any one of the above. [Examples]

[0118] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0119] Methods for measuring weight-average molecular weight (Mw) and number-average molecular weight (Mn) The weight-average molecular weight and number-average molecular weight were calculated from a calibration curve using standard polystyrene by gel permeation chromatography (GPC). The calibration curve was approximated by a cubic equation using standard polystyrene: TSKstandard POLYSTYRENE (Type; A-2500, A-5000, F-20, F-80) (manufactured by Tosoh Corporation, trade name). The GPC measurement conditions are shown below.

[0120] Equipment: High-speed GPC system HLC-8320GPC (Tosoh Corporation, product name) Detector: UV-8320 ultraviolet absorption detector (Tosoh Corporation, product name) Columns: Guard column; TSKgel guardcolumn Super(HZ)-M+, Column; TSKgel SuperMultipore HZ-M (2 pieces), Reference column; TSKgel SuperH-RC (2 pieces) (All products are from Tosoh Corporation) Column sizes: 4.6 x 20 mm (guard column), 4.6 x 150 mm (column), 6.0 x 150 mm (reference column) Eluent: Tetrahydrofuran Sample concentration: 10 mg / 1 mL Injection volume: 20 μL or 2 μL Flow rate: 0.35mL / min Measurement temperature: 40℃

[0121] [Manufacturing of resin (A-1)] In a 500 mL reaction vessel equipped with a stirrer, thermometer, reflux tubing, and nitrogen inlet, 35.6 parts by mass of indene, 124.9 parts by mass of chloromethylstyrene (*1), 6.5 parts by mass of α-chloro-p-xylene, 7.1 parts by mass of tetra-n-butylammonium bromide as a phase transfer catalyst, 0.1 parts by mass of phenothiazine as a polymerization inhibitor, and 94.5 parts by mass of toluene as a solvent were charged, and the mixture was heated and stirred at 40°C while blowing nitrogen at a flow rate of 50 mL / min.

[0122] Next, 125 parts by mass of a 48% sodium hydroxide aqueous solution were added dropwise over 20 minutes, and the mixture was stirred at 60°C for 9 hours. Nitrogen was continuously blown in during the reaction. After cooling to room temperature (25°C) and neutralizing with a 10% hydrochloric acid aqueous solution, the mixture was washed twice with pure water. After removing toluene under reduced pressure, the resulting viscous liquid was washed with methanol and vacuum-dried to obtain resin (A-1).

[0123] Chloromethylstyrene (*1): AGC Seimi Chemical Co., Ltd. "CMS-P", a mixture of m-isomer and p-isomer, m-isomer content approximately 50% by mass, p-isomer content approximately 50% by mass.

[0124] [Examples 1-3 and Comparative Example 1] A curable composition was prepared by blending each component in the proportions shown in Table 1 and adjusting the solid content to approximately 65% ​​by mass with toluene. For components that are solutions, the amounts shown in Table 1 are calculated on a solid content basis. The following evaluation tests were performed on the obtained curable composition. The results are also shown in Table 1.

[0125] The details of each component described in Table 1 are as follows. · Resin (A-1): The resin (A-1) obtained previously · Resin (2): A polymerizable group-containing aromatic polyether compound, "HC-G0037" manufactured by JSR Corporation · Azo radical polymerization initiator (B-1): 2,2'-azobis(2,4,4-trimethylpentane), "VR-110" manufactured by Fujifilm Wako Pure Chemical Corporation · Imidazole compound (C-1): Isocyanate masked imidazole, "G8009L" of Daiichi Kogyo Seiyaku Co., Ltd. (in the general formula (6), R 8 and R 10 are methyl groups, R [[ID=1​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

[0130] [Fabrication of double-sided copper-clad laminated boards] Ten layers of the obtained prepreg were stacked together. On both sides of these layers, 18 μm thick electrolytic copper foil ("SI-VSP-18" manufactured by Mitsui Mining & Smelting Co., Ltd.) was laid with the matte side facing the prepreg. This was then heated and pressurized at 210°C for 80 minutes under a vacuum press condition of 3 MPa to obtain a double-sided copper-clad laminate.

[0131] [Measurement of the minimum melt viscosity of curable compositions] The curable composition portion was extracted from the previously obtained prepreg by grinding it into a powder, and molded into tablets approximately 1.2 mm thick and 20 mm in diameter. These tablets were used as samples for melt viscosity measurement. The melt viscosity of the samples was measured under the following conditions, and the minimum melt viscosity and the temperature at which the minimum melt viscosity was reached (minimum melting temperature) were obtained. Measuring instrument (rheometer): "DHR-20" manufactured by T.A. Instrument Japan Co., Ltd. Temperature range and heating conditions: 40-180°C, 3°C / min

[0132] [Measurement of the coefficient of thermal expansion (CTE)] The copper foil was removed from the double-sided copper-clad laminate obtained earlier by immersion in a copper etching solution (*3), and a test specimen measuring 5 mm in length (X direction), 5 mm in width (Y direction), and 0.6 mm in thickness (Z direction) was prepared. The coefficient of thermal expansion in the X direction of this test specimen was measured using a TMA test apparatus (TA Instruments, Q400). The heating rate was set to 10°C / min, and the average coefficient of thermal expansion over a temperature range of 30 to 120°C was used for evaluation.

[0133] (*3) Copper etching solution: Ammonium persulfate solution (manufactured by Mitsubishi Gas Chemical Company, Inc.)

[0134] [Table 1]

[0135] As shown in Table 1, Examples 1 to 3, which included resin (A), initiator (B), and compound (C), showed an increased minimum melt viscosity measured under heating conditions and improved thermal expansion resistance of the prepreg compared to Comparative Example 1, which did not include initiator (B) and compound (C).

Claims

1. The resin contains at least two compounds that have different structures from the compounds represented by the following general formula (1), and R is present in the resin. １ , R ２ and R ３ At least one of them is a vinylbenzyl group, and R present in the resin １ , R ２ and R ３ A curable composition comprising a resin (A) in which at least one of the members is an arylalkyl group other than a vinylbenzyl group, an azo radical polymerization initiator (B), and an imidazole compound (C). 【Chemistry 1】 In general formula (1), R １ , R ２ and R ３ are each independently a hydrogen atom, a vinylbenzyl group, or an arylalkyl group other than a vinylbenzyl group. R ４ is a hydrogen atom, a monovalent organic group, or a halogen atom, and all four R ４ may be different from each other, or two or more of the four R ４ may be the same as each other.]

2. The curable composition according to claim 1, wherein the content of the azo radical polymerization initiator (B) is in the range of 0.05 to 2 parts by mass per 100 parts by mass of the resin (A).

3. The curable composition according to claim 1, wherein the content of the imidazole compound (C) is in the range of 0.01 to 2 parts by mass per 100 parts by mass of the resin (A).

4. The curable composition according to claim 1, wherein the content of the imidazole compound (C) per 100 parts by mass of the azo radical polymerization initiator (B) is in the range of 20 to 120 parts by mass.

5. The curable composition according to claim 1, wherein the arylalkyl group other than the vinylbenzyl group contained in the resin (A) does not have a polymerizable unsaturated bond.

6. A prepreg comprising a curable composition according to any one of claims 1 to 5 or a semi-cured product of the curable composition.

7. A resin film comprising a curable composition according to any one of claims 1 to 5 or a semi-cured product of the curable composition.

8. A metal-clad laminate comprising a cured product of a curable composition according to any one of claims 1 to 5 and a metal foil.

9. A printed circuit board comprising a cured product of a curable composition according to any one of claims 1 to 5.

10. A semiconductor package comprising a printed circuit board according to claim 9 and a semiconductor element.

11. A semiconductor package comprising a semiconductor element and a cured product of a curable composition according to any one of claims 1 to 5 for sealing the semiconductor element.

12. A printed circuit board comprising at least one of a surface protective film and an interlayer insulating film formed by the curable composition according to any one of claims 1 to 5.

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