TWI858163B - Resin composition - Google Patents

Abstract

The subject of the present invention is to provide a resin composition for obtaining a cured product having excellent flexibility, halo phenomenon suppression characteristics and heat resistance. The solution is a resin composition containing (A) a polyimide resin, (B) a carbodiimide resin, and (C) an inorganic filler, wherein the content of the component (C) is less than 40% by mass when the non-volatile component in the resin composition is 100% by mass.

Description

Resin composition

The present invention relates to a resin composition containing a polyimide resin, and more particularly to a cured product, a resin sheet, a multi-layer flexible substrate, and a semiconductor device obtained by using the resin composition.

In recent years, there has been an increasing demand for thinner and lighter semiconductor components with a higher packaging density. In order to respond to this demand, the use of flexible substrates as substrates for semiconductor components has attracted attention. Flexible substrates can be thinner and lighter than rigid substrates. Furthermore, since flexible substrates are flexible and deformable, they can be bent for packaging.

To date, a composition containing a carbodiimide resin is known (Patent Document 1). [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2016-027097

[The problem that the invention wants to solve]

In the case of a flexible substrate insulating material, a polyimide resin is mixed in order to improve flexibility. In this case, when the amount of inorganic filler contained in the insulating material is small, the occurrence of the halo phenomenon is significant and the heat resistance tends to decrease.

The subject of the present invention is to provide a resin composition for obtaining a cured product having excellent flexibility, halo phenomenon suppression characteristics and heat resistance. [Means for solving the subject]

In order to achieve the subject of the present invention, the inventors of the present invention have conducted in-depth research and found that by using a resin composition containing (A) a polyimide resin, (B) a carbodiimide resin, and less than 40% by weight of (C) an inorganic filler, a hardened material with excellent flexibility, anti-halation properties and heat resistance can be obtained, thereby completing the present invention.

That is, the present invention includes the following contents. [1] A resin composition comprising (A) a polyimide resin, (B) a carbodiimide resin, and (C) an inorganic filler, wherein the content of component (C) is less than 40% by mass, based on 100% by mass of the non-volatile components in the resin composition. [2] The resin composition of [1] above, wherein the weight average molecular weight of component (A) is greater than 1,000 and less than 100,000. [3] The resin composition of [1] or [2] above, wherein the content of component (A) is greater than 15% by mass, based on 100% by mass of the non-volatile components in the resin composition. [4] A resin composition as described in any one of [1] to [3] above, wherein the content of component (A) is 35% by mass or less, based on 100% by mass of the non-volatile components in the resin composition. [5] A resin composition as described in any one of [1] to [4] above, wherein component (B) is polycarbodiimide. [6] A resin composition as described in any one of [1] to [5] above, wherein the content of isocyanate groups in the molecule of component (B) is 0.2% by mass or less. [7] A resin composition as described in any one of [1] to [6] above, wherein the content of component (B) is 3% by mass or more, based on 100% by mass of the non-volatile components in the resin composition. [8] A resin composition as described in any one of [1] to [7] above, wherein the content of component (B) is 15% by mass or less, based on 100% by mass of the non-volatile components in the resin composition. [9] A resin composition as described in any one of [1] to [8] above, wherein the mass ratio of component (B) to component (A) (component (B)/component (A)) is 0.1 or more. [10] A resin composition as described in any one of [1] to [9] above, wherein the mass ratio of component (B) to component (A) (component (B)/component (A)) is 0.5 or less. [11] A resin composition as described in any one of [1] to [10] above, wherein component (C) is silicon dioxide. [12] A resin composition as described in any one of [1] to [11] above, wherein the average particle size of component (C) is less than 1 μm. [13] A resin composition as described in any one of [1] to [12] above, further comprising (D) an epoxy resin. [14] A resin composition as described in any one of [1] to [13] above, further comprising (E) a hardener. [15] A resin composition as described in [14] above, wherein component (E) comprises an active ester hardener. [16] A resin composition as described in any one of [1] to [15] above, which is used to form an insulating layer of a multi-layer flexible substrate. [17] A cured product of a resin composition as described in any one of [1] to [16] above. [18] A resin sheet comprising a support and a resin composition layer formed by a resin composition as described in any one of [1] to [16] and disposed on the support. [19] A multi-layer flexible substrate comprising an insulating layer formed by hardening a resin composition as described in any one of [1] to [16]. [20] A semiconductor device having a multi-layer flexible substrate as described in [19]. [Effect of the Invention]

According to the resin composition of the present invention, a hardened material having excellent flexibility, halo phenomenon suppression characteristics and heat resistance can be obtained.

The present invention is described in detail below based on its suitable embodiments. However, the present invention is not limited to the following embodiments and examples, and can be implemented with any changes within the scope of the patent application of the present invention and its equivalents.

<Resin composition> The resin composition of the present invention is a resin composition containing (A) a polyimide resin, (B) a carbodiimide resin, and (C) an inorganic filler, wherein the content of component (C) is less than 40% by mass. By using such a resin composition, a cured product having excellent flexibility, haloing suppression properties, and heat resistance can be obtained.

The resin composition of the present invention may further contain any component in addition to (A) polyimide resin, (B) carbodiimide resin, and (C) inorganic filler. Examples of the optional component include (D) epoxy resin, (E) hardener, (F) hardening accelerator, (G) other additives, and (H) organic solvent. The following is a detailed description of each component contained in the resin composition.

<(A) Polyimide resin> The resin composition of the present invention contains (A) polyimide resin. (A) Polyimide resin is a resin having imide bonds in repeating units. (A) Polyimide resin is not particularly limited, and may include, for example, (1) a resin obtained by an imidization reaction of a diamine compound and tetracarboxylic anhydride, or (2) a resin obtained by an imidization reaction of a diisocyanate compound and tetracarboxylic anhydride. (A) Polyimide resin also includes modified polyimide resins such as siloxane-modified polyimide resins.

(A) The polyimide resin is not particularly limited, and may, for example, comprise formula (A1):

[In the formula, ^X1 represents a tetravalent group obtained by removing two -CO-O-CO- from tetracarboxylic dianhydride, and may be, for example, an organic group containing two or more (e.g., 2 to 3,000, 2 to 1,000, 2 to 100, or 2 to 50) backbone atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms. ^X2 represents a divalent group obtained by removing two _-NH2 from a diamine compound, or a divalent group obtained by removing two -NCO from a diisocyanate compound, and may be, for example, an organic group containing two or more (e.g., 2 to 3,000, 2 to 1,000, 2 to 100, or 2 to 50) backbone atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms. n represents an integer greater than 2] a structure represented by. The organic groups of ^X1 and ^X2 in formula (A1) are not particularly limited as long as they are chemically stable structures, and can be appropriately selected by a person skilled in the art, for example, a structure of a known polyimide resin. (A) When the polyimide resin contains the structure represented by formula (A1), it preferably contains 60% by mass or more of the structure represented by formula (A1), more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

The diamine compound used to prepare the polyimide resin (A) is not particularly limited, and examples thereof include aliphatic diamine compounds and aromatic diamine compounds.

Aliphatic diamine compounds include, for example, linear aliphatic diamine compounds such as 1,2-ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-hexamethylenediamine, 1,5-diaminopentane, and 1,10-diaminodecane; 1,2-diamino-2-methylpropane, 2,3-diamino-2,3-butane, 2- Branched chain aliphatic diamine compounds such as methyl-1,5-diaminopentane; alicyclic diamine compounds such as 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine); dimer acid type diamine (hereinafter also referred to as "dimer diamine"), etc.

Dimer acid type diamine refers to a diamine compound obtained by replacing the two terminal carboxyl groups (-COOH) of the dimer acid with aminomethyl (-CH ₂ -NH ₂ ) or amino (-NH ₂ ). Dimer acid is a known compound obtained by dimerizing unsaturated fatty acids (preferably those with 11 to 22 carbon atoms, particularly preferably those with 18 carbon atoms), and its industrial production process has been roughly standardized in the industry. Dimer acid can be easily obtained by dimerizing unsaturated fatty acids with 18 carbon atoms such as oleic acid and linolenic acid, which are particularly cheap and easily available, and having a dimer acid with 36 carbon atoms as the main component. In addition, the dimer acid may contain any amount of monomeric acid, trimer acid, other polymerized fatty acids, etc. depending on the production method, the degree of purification, etc. In addition, after the polymerization reaction of unsaturated fatty acids, double bonds remain. However, in this specification, the hydrogenated products whose unsaturation is reduced by further hydrogenation are also included in the dimer acid. Dimer acid type diamines can be obtained from commercial products, for example, "PRIAMINE1073", "PRIAMINE1074", "PRIAMINE1075" manufactured by Croda Japan, "Versamine 551", "Versamine 552" manufactured by Cognis Japan, etc.

Examples of aromatic diamine compounds include 1,4-phenylenediamine, 1,2-phenylenediamine, 1,3-phenylenediamine, 2,4-diaminotoluene, 2,6-diaminotoluene, 3,5-diaminobiphenyl, 2,4,5,6-tetrafluoro-1,3-phenylenediamine and the like; 1,5-diaminonaphthalene, 1,8-diaminonaphthalene, 2,6-diaminonaphthalene, 2,3-diaminonaphthalene and the like naphthalenediamine compounds; 4,4'-diamino-2,2'-di-trifluoromethyl-1 , 1'-biphenyl, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 4-aminophenyl 4-aminobenzoate, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2,2-bis(4-aminophenyl)propane, 4,4'-(hexafluoroisopropyl)propane 2,2-Bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, α,α-bis[4-(4-aminophenoxy)phenyl]-1,3-diisopropylbenzene, α,α-bis[4-(4-aminophenoxy)phenyl]-1,4-diisopropylbenzene, 4,4'-(9-fluorenyl)diphenylamine, 2,2-bis(3-methyl-4-aminophenyl)propane, 2,2-bis(3- diphenylamine compounds such as 4-(4-aminophenyl)diaminobenzene, 4,4'-diamino-3,3'-dimethyl-1,1'-biphenyl, 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl, 9,9'-bis(3-methyl-4-aminophenyl)fluorene, 5-(4-aminophenoxy)-3-[4-(4-aminophenoxy)phenyl]-1,1,3-trimethylindane, and 4-aminobenzoic acid 5-amino-1,1'-biphenyl-2-yl ester.

As the diamine compound, a commercially available one may be used, or one synthesized by a known method may be used. The diamine compound may be used alone or in combination of two or more.

The diisocyanate compound used to prepare the polyimide resin (A) is not particularly limited, and examples thereof include aliphatic diisocyanate compounds, aromatic diisocyanate compounds, and polyurethanes having isocyanate groups at both ends.

Aliphatic diisocyanate compounds include, for example, linear aliphatic diisocyanate compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, octamethylene diisocyanate, and dodecamethylene diisocyanate; branched aliphatic diisocyanate compounds such as 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and 2,2-dimethylpentamethylene diisocyanate; isophorone diisocyanate (IPDI), cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate (CHDI), 4-methylcyclohexane-1,3- diisocyanate, 2-methylcyclohexane-1,3-diisocyanate, 2-methylcyclohexane-1,4-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexyl ether-4,4'-diisocyanate, 1,4-bis(isocyanatomethyl)cyclohexane, 1,3-bis(isocyanatomethyl)cyclohexane alicyclic diisocyanate compounds such as 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, 3a,4,5,6,7,7a-hexahydro-4,7-oxomethyleneindane-1,8-ylidene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, etc.; dimer acid type diisocyanate, etc.

The dimer acid type diisocyanate refers to a diisocyanate compound obtained by replacing the amino group (—NH ₂ ) of the dimer acid type diamine described above with an isocyanate group (—NCO).

Aromatic diisocyanate compounds include, for example, 1,4-phenylenediisocyanate, 1,3-phenylenediisocyanate, toluene-2,6-diisocyanate, toluene-2,4-diisocyanate, toluene-3,5-diisocyanate, 2-methyl-4,6-diisopropylbenzene-1,3-diisocyanate, 2,4,6-triethylbenzene-1,3-diisocyanate, 4,6-diethylbenzene-1,3-diisocyanate, 2,5-diethyl 1,3-diisocyanate, 2,5-diethylbenzene-1,4-diisocyanate, 2,4,6-triisopropylbenzene-1,3-diisocyanate, 4,6-diisopropylbenzene-1,3-diisocyanate, 2,5-diisopropylbenzene-1,3-diisocyanate, 2,5-diisopropylbenzene-1,4-diisocyanate, m-xylene diisocyanate, p-xylene diisocyanate, tetramethyl-m-xylene diisocyanate diisocyanate, tetramethyl-p-xylene diisocyanate and the like; naphthalene diisocyanate compounds such as 1,3-naphthalene diisocyanate, 1,6-naphthalene diisocyanate, 1,7-naphthalene diisocyanate, 1,8-naphthalene diisocyanate, 2,6-naphthalene diisocyanate, 2,7-naphthalene diisocyanate; diphenylmethane-4,4'-diisocyanate, diphenyl ether-4,4'-diisocyanate; Isocyanates, diphenyl ether-2,4'-diisocyanate, biphenyl-4,4'-diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, 3,3'-dimethoxybiphenyl-4,4'-diisocyanate, 3,3'-dimethoxydiphenylmethane-4,4'-diisocyanate, 4,4'-dimethoxydiphenylmethane-3,3'-diisocyanate and other bis(isocyanatobenzene) compounds.

The polyurethane containing isocyanate groups at both ends may be obtained by subjecting the above-mentioned aliphatic diisocyanate compounds and/or aromatic diisocyanate compounds to a urethanization reaction with a polymer containing hydroxyl groups at both ends. The polymer containing hydroxyl groups at both ends may be, for example, a polyolefin containing hydroxyl groups at both ends such as polybutadiene containing hydroxyl groups at both ends, hydrogenated polybutadiene containing hydroxyl groups at both ends, polyisoprene containing hydroxyl groups at both ends, or hydrogenated polyisoprene containing hydroxyl groups at both ends; or a polyether containing hydroxyl groups such as polyethylene glycol containing hydroxyl groups at both ends, polypropylene glycol containing hydroxyl groups at both ends, or polytetramethylene glycol containing hydroxyl groups at both ends.

The number average molecular weight of the polymer having hydroxyl groups at both ends is not particularly limited, but is preferably 500 or more, more preferably 1,000 or more, and even more preferably 2,000 or more. The upper limit of the number average molecular weight of the polymer having hydroxyl groups at both ends is not particularly limited, but is preferably 10,000 or less, and more preferably 8,000 or less. The number average molecular weight here may be a value measured by gel permeation chromatography (GPC) (polystyrene conversion).

The polyurethane with isocyanate groups at both ends is, for example, of formula (A2):

[In the formula, ^X2a is a divalent group obtained by removing two -NCO groups from an aliphatic diisocyanate compound or an aromatic diisocyanate compound, and can be, for example, an organic group containing 2 to 50 backbone atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms. ^X2b is a divalent group obtained by removing two -OH groups from a polymer having hydroxyl groups at both ends, and can be, for example, an organic group containing 2 or more backbone atoms (e.g., 2 to 1,000, 2 to 500) selected from carbon atoms and oxygen atoms. m is an integer of 1 to 10] represented by a polyurethane having isocyanate groups at both ends.

As the diisocyanate compound, a commercially available one may be used, or one synthesized by a known method or a method based thereon may be used. The diisocyanate compound may be used alone or in combination of two or more.

The tetracarboxylic anhydride used to prepare the polyimide resin (A) is not particularly limited, and examples thereof include aliphatic tetracarboxylic dianhydride and aromatic tetracarboxylic dianhydride.

Aliphatic tetracarboxylic dianhydrides include, specifically, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexane-1,2,3,4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, 3,3',4,4'-biscyclohexyltetracarboxylic dianhydride, carbonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, methylene- 4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,2-ethylidene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, oxy-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, thio-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, sulfonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, and the like.

Aromatic tetracarboxylic dianhydrides include, for example, benzenetetracarboxylic dianhydride such as pyromellitic dianhydride and 1,2,3,4-benzenetetracarboxylic dianhydride; naphthalenetetracarboxylic dianhydride such as 1,4,5,8-naphthalenetetracarboxylic dianhydride and 2,3,6,7-naphthalenetetracarboxylic dianhydride; anthracenetetracarboxylic dianhydride such as 2,3,6,7-anthracenetetracarboxylic dianhydride; 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-diphenylethertetracarboxylic dianhydride, 3,3',4,4'- Diphenylsulfonate tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-benzophenonetetracarboxylic dianhydride, 2,3,3',4'-diphenylethertetracarboxylic dianhydride, 2,3,3',4'-diphenylsulfonate tetracarboxylic dianhydride, 2,2'-bis(3,4-dicarboxyphenoxyphenyl)sulfonate dianhydride, methylene-4,4 '-diphthalic acid anhydride, 1,1-ethynylene-4,4'-diphthalic acid anhydride, 2,2-propylene-4,4'-diphthalic acid anhydride, 1,2-ethylene-4,4'-diphthalic acid anhydride, 1,3-trimethylene-4,4'-diphthalic acid anhydride, 1,4-tetramethylene-4,4'-diphthalic acid anhydride, 1,5-pentamethylene-4,4'-diphthalic acid anhydride, 1,3-bis(3, Phthalic acid dianhydride such as 1,4-bis(3,4-dicarboxyphenyl)phthalic anhydride, 1,4-bis(3,4-dicarboxyphenyl)phthalic anhydride, 1,3-bis(3,4-dicarboxyphenoxy)phthalic anhydride, 1,4-bis(3,4-dicarboxyphenoxy)phthalic anhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 4,4'-(4,4'-isopropylidene diphenoxy)bisphthalic acid dianhydride, and the like.

As tetracarboxylic dianhydride, commercially available ones may be used, or those synthesized by a known method or a method based thereon may be used. Tetracarboxylic dianhydride may be used alone or in combination of two or more.

The content of the structure derived from the aromatic tetracarboxylic dianhydride relative to the entire structure derived from the tetracarboxylic dianhydride constituting the polyimide resin (A) is preferably 10 mol % or more, more preferably 30 mol % or more, even more preferably 50 mol % or more, still more preferably 70 mol % or more, still more preferably 90 mol % or more, and particularly preferably 100 mol %.

The weight average molecular weight of the polyimide resin (A) is not particularly limited, but is preferably 1,000 or more, more preferably 3,000 or more, even more preferably 5,000 or more, and particularly preferably 7,000 or more. The upper limit of the weight average molecular weight of the polyimide resin (A) is not particularly limited, but is preferably 100,000 or less, more preferably 80,000 or less, particularly preferably 60,000 or less, and particularly preferably 50,000 or less. The number average molecular weight of the polyimide resin (A) is not particularly limited, but is preferably 1,000 or more, more preferably 3,000 or more, even more preferably 5,000 or more, and particularly preferably 7,000 or more. (A) The upper limit of the number average molecular weight of the polyimide resin is not particularly limited, but is preferably 100,000 or less, more preferably 80,000 or less, particularly preferably 60,000 or less, and particularly preferably 50,000 or less. The weight average molecular weight and number average molecular weight herein may be values measured by gel permeation chromatography (GPC) (polystyrene conversion).

The content of the polyimide resin (A) in the resin composition is not particularly limited, and is preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, still more preferably 35% by mass or less, and particularly preferably 30% by mass or less, based on 100% by mass of the nonvolatile components in the resin composition. The lower limit of the content of the polyimide resin (A) in the resin composition is not particularly limited, and is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more, based on 100% by mass of the nonvolatile components in the resin composition.

<(B) Carbodiimide resin> The resin composition of the present invention contains (B) carbodiimide resin. (B) Carbodiimide resin is a compound having one or more carbodiimide structures (-N=C=N-) in one molecule. (B) Carbodiimide resin is preferably a compound having two or more carbodiimide structures in one molecule, and polycarbodiimide having a carbodiimide structure in a repeating unit is particularly preferred. Polycarbodiimide may be cyclic or chain-shaped.

The polycarbodiimide is not particularly limited, and may include, for example, polycarbodiimide obtained by decarbonation condensation reaction between molecules of a diisocyanate compound. The polycarbodiimide obtained in this manner has an isocyanate group (-N=C=O) in the molecule, and part or all of it may be further treated with a known sealant such as a monoisocyanate compound, an alcohol compound, an amine compound, a carboxylic acid compound, an epoxy compound, etc. The diisocyanate compound used to prepare the polycarbodiimide may be, for example, the same as the diisocyanate compound used to prepare the (A) polyimide resin. The (B) carbodiimide resin may be used alone or in combination of two or more.

(B) Carbodiimide resin is not particularly limited, and preferably comprises formula (B1):

[wherein ^X3 represents a divalent group obtained by removing two -NCO groups from a diisocyanate compound, for example, an organic group comprising two or more (for example, 2 to 50, 2 to 40, 2 to 30, 2 to 20) backbone atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms, and in one embodiment, may be an alkylene group, an arylene group, an arylene group substituted with an alkyl group, and a combination thereof. p represents an integer greater than 2] a polycarbodiimide having a structure represented by.

"Alkylene" refers to a straight chain, branched chain and/or cyclic divalent aliphatic saturated hydrocarbon group. The number of carbon atoms in "alkylene" can be, for example, 2 to 30, 2 to 20, etc. Examples of the “alkylene” include straight chain alkylene such as ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, and octamethylene; ethylene, propylene, isopropylene, 1-methylethylene, 1-ethylethylene, trimethylene, 2-methyltrimethylene, 2-methyltetramethylene, 2,3-dimethyltetramethylene, 1,3-dimethyltetramethylene, 2-methylpentamethylene, 2,2-dimethylpentamethylene, 2,4-dimethylpentamethylene, 1,3,5-methylpentamethylene, 2-methylhexamethylene, 2,2-dimethylhexamethylene, 2,4-dimethylhexamethylene, 1,3,5-trimethylhexamethylene, 2, Branched chain alkylene groups such as 2,4-trimethylhexamethylene and 2,4,4-trimethylhexamethylene; cyclic alkylene groups such as 1,3-cyclopentylene, 1,3-cyclohexylene, 1,4-cyclohexylene, 4-methyl-1,3-cyclohexylene, 2-methyl-1,3-cyclohexylene and 2-methyl-1,4-cyclohexylene; methylene cyclohexylene di(4,1-cyclohexylene) group, etc.; cyclo-branched-chain-cycloalkylene groups such as isopropylene di(4,1-cyclohexylene) group, etc.; straight-chain-cyclo-straight-chain alkylene groups such as 1,4-cyclohexylene dimethylene group, etc.; branched-chain-cyclo-branched-chain alkylene groups such as 1,4-cyclohexylene diisopropylene group, etc.

"Arylene" refers to a divalent aromatic hydrocarbon group. The number of carbon atoms in an "arylene" may be, for example, 6 to 14, 6 to 10, etc. Examples of "arylene" include 1,3-phenylene, 1,4-phenylene, 1,5-naphthylene, 1,8-naphthylene, 2,6-naphthylene, etc. "Arylene substituted with an alkyl group" refers to an arylene group substituted with an alkyl group such as methyl, ethyl, propyl, isopropyl, etc. The number of carbon atoms in an "arylene substituted with an alkyl group" may be, for example, 7 to 30, 7 to 20, etc. Examples of the “alkyl-substituted aryl group” include 2,6-tolyl, 2,4-tolyl, 3,5-tolyl, 2-methyl-4,6-diisopropyl-1,3-phenylene, 2,4,6-triethyl-1,3-phenylene, 4,6-diethyl-1,3-phenylene, 2,5-diethyl-1,3-phenylene, 2,5-diethyl-1,4-phenylene, 2,4,6-triisopropyl-1,3-phenylene, 4,6-diisopropyl-1,3-phenylene, 2,5-diisopropyl-1,3-phenylene, and 2,5-diisopropyl-1,4-phenylene. Examples of combinations of alkylene groups, arylene groups, and alkyl-substituted arylene groups include alkylene groups-arylene groups-alkylene groups, alkylene groups-alkyl-substituted arylene groups-alkylene groups, arylene groups-alkylene groups-arylene groups, alkylene groups-substituted arylene groups-alkylene groups-alkyl-substituted arylene groups, and the like. Alkylene groups, arylene groups, and alkyl-substituted arylene groups may further have any substituents.

The organic group of ^X3 in formula (B1) is not particularly limited as long as it is a chemically stable structure, and can be appropriately selected by a person skilled in the art, for example, it can be a known polycarbodiimide structure.

In one embodiment, (B) carbodiimide resins include aliphatic polycarbodiimides such as polyhexamethylene carbodiimide, polytrimethylhexamethylene carbodiimide, polycyclohexylene carbodiimide, poly(methylene dicyclohexylene carbodiimide), poly(isophorone carbodiimide), or poly(phenylene carbodiimide), poly(naphthylene carbodiimide), poly(tolylene carbodiimide), poly(methyl diisopropylphenylene carbodiimide). Polycarbodiimide of aromatic polycarbodiimide such as poly(triethylphenylene carbodiimide), poly(diethylphenylene carbodiimide), poly(triisopropylphenylene carbodiimide), poly(diisopropylphenylene carbodiimide), poly(xylylene carbodiimide), poly(tetramethylxylylene carbodiimide), poly(methylenebisphenylene carbodiimide), poly[methylenebis(methylphenylene) carbodiimide], etc.

The content of isocyanate groups (-N=C=O) in the molecules of the carbodiimide resin (B) is preferably 10% by mass or less, more preferably 5% by mass or less, 3% by mass or less, still more preferably 2% by mass or less, 1% by mass or less, still more preferably 0.5% by mass or less, 0.2% by mass or less, and particularly preferably 0% by mass. In other words, it is particularly preferred that the carbodiimide resin (B) does not contain isocyanate groups.

(B) Commercially available products of carbodiimide resins include, for example, "Carbodilite (registered trademark) V-02B", "Carbodilite (registered trademark) V-03", "Carbodilite (registered trademark) V-04K", "Carbodilite (registered trademark) V-07" and "Carbodilite (registered trademark) V-09" manufactured by Nisshin Chemical Co., Ltd.; "Stabaxol (registered trademark) P", "Stabaxol (registered trademark) P400", "Hycasyl (registered trademark) 510" manufactured by Rhein Chemie Co., Ltd., and the like.

The content of the carbodiimide resin (B) in the resin composition is not particularly limited, but is preferably 50% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, even more preferably 15% by mass or less, and particularly preferably 10% by mass or less, based on 100% by mass of the nonvolatile components in the resin composition. The lower limit of the content of the carbodiimide resin (B) in the resin composition is not particularly limited, but is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, even more preferably 3% by mass or more, and particularly preferably 5% by mass or more, based on 100% by mass of the nonvolatile components in the resin composition.

The mass ratio of the (B) carbodiimide resin to the (A) polyimide resin in the resin composition ((B) carbodiimide resin/(A) polyimide resin) is not particularly limited, but is preferably 5 or less, more preferably 1 or less, further preferably 0.5 or less, and further preferably 0.3 or less. The lower limit of the mass ratio ((B) carbodiimide resin/(A) polyimide resin) is not particularly limited, but is preferably 0.01 or more, more preferably 0.05 or more, further preferably 0.1 or more, and further preferably 0.2 or more.

<(C) Inorganic filler> The resin composition of the present invention contains (C) an inorganic filler. (C) The inorganic filler is contained in the resin composition in the form of particles.

(C) The material of the inorganic filler is an inorganic compound. (C) The material of the inorganic filler includes, for example, silicon dioxide, aluminum oxide, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, alumina, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silicon dioxide is particularly suitable. Examples of silicon dioxide include amorphous silicon dioxide, fused silicon dioxide, crystallized silicon dioxide, synthetic silicon dioxide, and hollow silicon dioxide. Preferably, the silicon dioxide is spherical silicon dioxide. (C) The inorganic filler may be used alone or in combination of two or more in any ratio.

(C) Commercially available products of inorganic fillers include, for example, "SP60-05" and "SP507-05" manufactured by Nippon Steel & Sumitomo Metal Materials Co., Ltd.; "YC100C", "YA050C", "YA050C-MJE", "YA010C", "SC2500SQ", "SO-C4", "SO-C2", and "SO-C1" manufactured by Admatechs; "Silfil NSS-3N", "Silfil NSS-4N", and "Silfil NSS-5N" manufactured by Tokuyama; "UFP-30", "DAW-03", and "FB-105FD" manufactured by Denka; and "IMSIL A-8", "IMSIL A-10", "IMSIL A-15", and "IMSIL A-25" manufactured by Unimin Co., Ltd.

(C) The average particle size of the inorganic filler is not particularly limited, but is preferably 40 μm or less, more preferably 10 μm or less, even more preferably 5 μm or less, even more preferably 3 μm or less, and particularly preferably 1 μm or less. (C) The lower limit of the average particle size of the inorganic filler is not particularly limited, but is preferably 0.005 μm or more, more preferably 0.01 μm or more, even more preferably 0.03 μm or more, even more preferably 0.05 μm or more, and particularly preferably 0.1 μm or more. (C) The average particle size of the inorganic filler can be measured by a laser diffraction/scattering method based on the Mie scattering theory. Specifically, the particle size distribution of the inorganic filler can be made on a volume basis using a laser diffraction scattering particle size distribution measuring device, and the average particle size can be measured by taking the median diameter as the average particle size. The measurement sample can be 100 mg of the inorganic filler and 10 g of methyl ethyl ketone weighed into a vial and dispersed ultrasonically for 10 minutes. Using the laser diffraction particle size distribution measuring device, the wavelength of the light source is set to blue and red, and the particle size distribution of the inorganic filler on a volume basis is measured by the flow cell method. The average particle size is calculated from the obtained particle size distribution in the form of the median diameter. Examples of laser diffraction particle size distribution measuring devices include the "LA-960" manufactured by Horiba, Ltd.

(C) The specific surface area of the inorganic filler is not particularly limited, but is preferably 0.1 m ² /g or more, more preferably 0.5 m ² /g or more, even more preferably 1 m ² /g or more, and particularly preferably 5 m ² /g or more. (C) The upper limit of the specific surface area of the inorganic filler is not particularly limited, but is preferably 50 m ² /g or less, more preferably 30 m ² /g or less, even more preferably 20 m ² /g or less, and particularly preferably 15 m ² /g or less. The specific surface area of the inorganic filler can be obtained by adsorbing nitrogen on the sample surface using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech) according to the BET method and calculating the specific surface area using the BET multipoint method.

The (C) inorganic filler is preferably surface treated with an appropriate surface treatment agent. By performing the surface treatment, the moisture resistance and dispersibility of the (C) inorganic filler can be improved. Examples of the surface treatment agent include vinyl trimethoxysilane, vinyl triethoxysilane and other vinyl silane coupling agents; epoxy silane coupling agents such as 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, 3-glycidyloxypropyl methyl dimethoxysilane, 3-glycidyloxypropyl trimethoxysilane, 3-glycidyloxypropyl methyl diethoxysilane, 3-glycidyloxypropyl triethoxysilane; styrene silane coupling agents such as p-styrene trimethoxysilane; 3-methacryloxypropyl methyl dimethoxysilane, 3-methylacryloxypropyl trimethoxysilane; Methacrylic silane coupling agents such as acryloyloxypropyl trimethoxysilane, 3-methacryloyloxypropyl methyldiethoxysilane, 3-methacryloyloxypropyl triethoxysilane, etc.; acrylic silane coupling agents such as 3-acryloyloxypropyl trimethoxysilane; N-2-(aminoethyl)-3-aminopropyl methyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyl trimethoxysilane, 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylene)propylamine, Amine-based silane coupling agents such as N-phenyl-3-aminopropyl trimethoxysilane, N-phenyl-8-aminooctyl trimethoxysilane, and N-(vinylbenzyl)-2-aminoethyl-3-aminopropyl trimethoxysilane; isocyanate-based silane coupling agents such as tris-(trimethoxysilylpropyl) isocyanate; urea-based silane coupling agents such as 3-ureidopropyl trialkoxysilane; 3-butyl propyl methyl dimethoxysilane, 3-butyl propyl trimethoxysilane; isocyanate-based silanes such as 3-isocyanate propyl triethoxysilane Coupling agent; silane coupling agent such as anhydride-based silane coupling agent such as 3-trimethoxysilylpropyl succinic anhydride; non-silane coupling-alkoxysilane compounds such as methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, 1,6-bis(trimethoxysilyl)hexane, trifluoropropyltrimethoxysilane, etc. Among them, amino-based silane coupling agents are particularly preferred. The surface treatment agent may be used alone or in combination of two or more in any ratio.

Commercially available surface treatment agents include, for example, "KBM-1003", "KBE-1003" (vinyl silane coupling agents); "KBM-303", "KBM-402", "KBM-403", "KBE-402", "KBE-403" (epoxy silane coupling agents); "KBM-1403" (styrene silane coupling agent); "KBM -502", "KBM-503", "KBE-502", "KBE-503" (methacrylic silane coupling agent); "KBM-5103" (acrylic silane coupling agent); "KBM-602", "KBM-603", "KBM-903", "KBE-903", "KBE-9103P", "KBM-573", "KBM-575" (amino "KBM-9659" (isocyanurate silane coupling agent); "KBE-585" (urea silane coupling agent); "KBM-802", "KBM-803" (methylene silane coupling agent); "KBE-9007N" (isocyanate silane coupling agent); "X-12-967C" (anhydride silane coupling agent); "KBM-13", "KBM-22 "KBM-103", "KBE-13", "KBE-22", "KBE-103", "KBM-3033", "KBE-3033", "KBM-3063", "KBE-3063", "KBE-3083", "KBM-3103C", "KBM-3066", "KBM-7103" (non-silane coupling-alkoxysilane compounds), etc.

The degree of surface treatment with the surface treatment agent is preferably within a specific range from the viewpoint of improving the dispersibility of the inorganic filler. Specifically, 100 mass% of the inorganic filler is preferably surface treated with 0.2 mass% to 5 mass% of the surface treatment agent, more preferably 0.2 mass% to 3 mass% of the surface treatment agent, and even more preferably 0.3 mass% to 2 mass% of the surface treatment agent.

The degree of surface treatment with the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. The amount of carbon per unit surface area of the inorganic filler is preferably 0.02 mg/ ^m2 or more, more preferably 0.1 mg/ ^m2 or more, and even more preferably 0.2 mg/ ^m2 or more from the viewpoint of improving the dispersibility of the inorganic filler. On the other hand, from the viewpoint of preventing the increase in the melt viscosity of the resin composition or the melt viscosity in the sheet form, it is preferably 1.0 mg/ ^m2 or less, more preferably 0.8 mg/m2 or ^less , and even more preferably 0.5 mg/m2 or ^less .

(C) The amount of carbon per unit surface area of the inorganic filler can be measured after the surface-treated inorganic filler is washed with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler that has been surface-treated with a surface treatment agent, and ultrasonically washed at 25°C for 5 minutes. After removing the supernatant and drying the solid components, a carbon analyzer can be used to measure the amount of carbon per unit surface area of the inorganic filler. The carbon analyzer that can be used is "EMIA-320V" manufactured by Horiba, Ltd.

The content of the (C) inorganic filler in the resin composition is less than 40% by mass, preferably 39% by mass or less, 38% by mass or less, more preferably 37% by mass or less, still more preferably 35% by mass or less, and particularly preferably 33% by mass or less, based on the non-volatile components in the resin composition as 100% by mass. The lower limit of the content of the (C) inorganic filler in the resin composition is not particularly limited, but preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 10% by mass or more, still more preferably 20% by mass or more, and particularly preferably 30% by mass or more, based on the non-volatile components in the resin composition as 100% by mass.

<(D) Epoxy resin> The resin composition of the present invention may contain (D) epoxy resin as an optional component. (D) Epoxy resin refers to a curable resin having an epoxy group.

(D) Epoxy resins include, for example, dimethylol type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, naphthol novolac type epoxy resins, phenol novolac type epoxy resins, tert-butyl-catechol type epoxy resins, naphthalene type epoxy resins, naphthol type epoxy resins, anthracene type epoxy resins, glycidylamine type epoxy resins, glycidyl ester type epoxy resins, Cresol novolac type epoxy resin, phenol aralkyl type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, epoxy resin with butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, epoxy resin containing spiro ring, oxalic acid type epoxy resin, oxalic acid dimethanol type epoxy resin, naphthyl ether type epoxy resin, trihydroxymethyl type epoxy resin, tetraphenylethane type epoxy resin, isocyanurate type epoxy resin, phenol benzyl formamide type epoxy resin, phenolphthalein type epoxy resin, etc. (D) Epoxy resins may be used alone or in combination of two or more.

The resin composition preferably contains an epoxy resin having two or more epoxy groups in one molecule as the epoxy resin (D). The proportion of the epoxy resin having two or more epoxy groups in one molecule relative to 100% by mass of the non-volatile component of the epoxy resin (D) is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more.

Epoxy resins include epoxy resins that are liquid at 20°C (hereinafter referred to as "liquid epoxy resins") and epoxy resins that are solid at 20°C (hereinafter referred to as "solid epoxy resins"). The resin composition of the present invention may contain only liquid epoxy resins, or only solid epoxy resins, or a combination of liquid epoxy resins and solid epoxy resins as epoxy resins. The epoxy resin in the resin composition of the present invention is preferably a solid epoxy resin, or a combination of a liquid epoxy resin and a solid epoxy resin; more preferably a solid epoxy resin.

The liquid epoxy resin is preferably a liquid epoxy resin having two or more epoxy groups in one molecule.

The liquid epoxy resin is preferably a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol AF type epoxy resin, a naphthalene type epoxy resin, a glycidyl ester type epoxy resin, a glycidyl amine type epoxy resin, a phenol novolac type epoxy resin, an alicyclic epoxy resin having an ester skeleton, a cyclohexane type epoxy resin, a cyclohexanedimethanol type epoxy resin, and an epoxy resin having a butadiene structure.

Examples of liquid epoxy resins include HP4032, HP4032D, and HP4032SS (naphthalene epoxy resins) manufactured by DIC Corporation; 828US, 828EL, jER828EL, 825, and Epikote manufactured by Mitsubishi Chemical Corporation; "828EL" (bisphenol A type epoxy resin); "jER807" and "1750" (bisphenol F type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER152" (phenol novolac type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "630", "630LSD", and "604" (glycidylamine type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "ED-523T" manufactured by ADEKA Corporation (Glycerol type epoxy resin); ADEKA's "EP-3950L", "EP-3980S" (glycidylamine type epoxy resin); ADEKA's "EP-4088S" (dicyclopentadiene type epoxy resin); Nippon Steel & Sumitomo Chemical's "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin); Nagase "EX-721" manufactured by ChemteX (glycidyl ester type epoxy resin); "Celloxide 2021P" manufactured by Daicel (aliphatic epoxy resin with ester skeleton); "PB-3600" manufactured by Daicel, "JP-100" and "JP-200" manufactured by Nippon Soda (epoxy resin with butadiene structure); "ZX1658" and "ZX1658GS" manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd. (liquid 1,4-glycidyl cyclohexane type epoxy resin), etc. These can be used alone or in combination of two or more.

The solid epoxy resin is preferably a solid epoxy resin having three or more epoxy groups in one molecule, and more preferably an aromatic solid epoxy resin having three or more epoxy groups in one molecule.

The solid epoxy resin is preferably a dimethylol epoxy resin, a naphthalene epoxy resin, a naphthalene tetrafunctional epoxy resin, a naphthol novolac epoxy resin, a cresol novolac epoxy resin, a dicyclopentadiene epoxy resin, a trisphenol epoxy resin, a naphthol epoxy resin, Resins, biphenyl type epoxy resins, naphthyl ether type epoxy resins, anthracene type epoxy resins, bisphenol A type epoxy resins, bisphenol AF type epoxy resins, phenol aralkyl type epoxy resins, tetraphenylethane type epoxy resins, phenol benzyl formamide type epoxy resins, phenolphthalein type epoxy resins.

Specific examples of solid epoxy resins include "HP4032H" (naphthalene-based epoxy resin) manufactured by DIC Corporation; "HP-4700" and "HP-4710" (naphthalene-based tetrafunctional epoxy resin) manufactured by DIC Corporation; "N-690" (cresol novolac-based epoxy resin) manufactured by DIC Corporation; "N-695" (cresol novolac-based epoxy resin) manufactured by DIC Corporation; "HP-7200", "HP-7200HH", "HP-7200H", and "HP-7200L" (dicyclopentadiene-based epoxy resin) manufactured by DIC Corporation; "E- XA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthyl ether type epoxy resin); "EPPN-502H" (triphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC7000L" (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC3000H", "NC3000", "NC3000L", "NC3000FH", "NC3100" (biphenyl type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; Nippon Steel Chemical "ESN475V" manufactured by Nippon Steel Chemical & Material Co., Ltd. (naphthalene type epoxy resin); "ESN485" manufactured by Nippon Steel Chemical & Material Co., Ltd. (naphthol type epoxy resin); "ESN375" manufactured by Nippon Steel Chemical & Material Co., Ltd. (dihydroxynaphthalene type epoxy resin); "YX4000H", "YX4000", "YX4000HK", "YL7890" manufactured by Mitsubishi Chemical Corporation (biphenyl type epoxy resin); "YL6121" manufactured by Mitsubishi Chemical Corporation (biphenyl type epoxy resin); "YX8800" manufactured by Mitsubishi Chemical Corporation (anthracene type epoxy resin); "YX7700" manufactured by Mitsubishi Chemical Corporation (phenol aralkyl type epoxy resin); large "PG-100" and "CG-500" manufactured by Hangas Chemical Co., Ltd.; "YL7760" manufactured by Mitsubishi Chemical Co., Ltd. (bisphenol AF type epoxy resin); "YL7800" manufactured by Mitsubishi Chemical Co., Ltd. (fluorene type epoxy resin); "jER1010" manufactured by Mitsubishi Chemical Co., Ltd. (bisphenol A type epoxy resin); "jER1031S" manufactured by Mitsubishi Chemical Co., Ltd. (tetraphenylethane type epoxy resin); "WHR991S" manufactured by Nippon Kayaku Co., Ltd. (benzyl methyl lactam type epoxy resin), etc. These can be used alone or in combination of two or more.

When a liquid epoxy resin and a solid epoxy resin are used in combination as component (D), the mass ratio of the solid epoxy resin to the liquid epoxy resin (solid epoxy resin/liquid epoxy resin) is not particularly limited, and is preferably 0.1 or more, more preferably 0.5 or more, even more preferably 1 or more, and particularly preferably 5 or more. The upper limit of the mass ratio of the solid epoxy resin to the liquid epoxy resin is not particularly limited, and is preferably 100 or less, more preferably 50 or less, even more preferably 30 or less, and particularly preferably 20 or less.

(D) The epoxy equivalent of the epoxy resin is preferably 50 g/eq. to 5,000 g/eq., more preferably 60 g/eq. to 2,000 g/eq., still more preferably 70 g/eq. to 1,000 g/eq., and still more preferably 80 g/eq. to 500 g/eq. The epoxy equivalent is the mass of the resin per 1 equivalent of epoxy group. The epoxy equivalent can be measured in accordance with JIS K7236.

(D) The weight average molecular weight (Mw) of the epoxy resin is preferably 100-5,000, more preferably 250-3,000, and even more preferably 400-1,500. The weight average molecular weight of the resin can be measured by gel permeation chromatography (GPC) as a value converted to polystyrene.

The content of the (D) epoxy resin in the resin composition is not particularly limited. When the non-volatile components in the resin composition are 100% by mass, it is preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, even more preferably 35% by mass or less, and particularly preferably 30% by mass or less. The lower limit of the content of the (D) epoxy resin in the resin composition is not particularly limited. When the non-volatile components in the resin composition are 100% by mass, for example, it is 0% by mass or more, 0.01% by mass or more; preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 10% by mass or more, even more preferably 20% by mass or more, and particularly preferably 25% by mass or more.

<(E) Hardener>

The resin composition of the present invention may further contain (E) a hardener. (E) The hardener has the function of hardening (D) the epoxy resin. The (E) hardener here is a component that is not equivalent to the (A) component ~ (D) component.

(E) The hardener is not particularly limited, and examples thereof include phenol hardeners, naphthol hardeners, anhydride hardeners, active ester hardeners, benzoxazine hardeners, and cyanate hardeners. A hardener may be used alone or in combination of two or more. (E) The hardener preferably includes a hardener selected from phenol hardeners, naphthol hardeners, and active ester hardeners; and particularly preferably includes an active ester hardener.

As the phenolic hardener and the naphthol hardener, from the viewpoint of heat resistance and water resistance, a phenolic hardener having a novolac structure or a naphthol hardener having a novolac structure is preferred. From the viewpoint of adhesion to the adherend, a nitrogen-containing phenolic hardener or a nitrogen-containing naphthol hardener is preferred, and a phenolic hardener containing a triazine skeleton or a naphthol hardener containing a triazine skeleton is more preferred. Among them, from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion, a phenolic novolac resin containing a triazine skeleton is preferred. Specific examples of phenolic hardeners and naphthol hardeners include "MEH-7700", "MEH-7810", "MEH-7851" manufactured by Wagaku Co., Ltd., "NHN", "CBN", "GPH" manufactured by Nippon Kayaku Co., Ltd., "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN-495", "SN-375", "SN-395" manufactured by Nippon Steel Chemical & Material Co., Ltd., "LA-7052", "LA-7054", "LA-3018", "LA-3018-50P", "LA-1356", "TD2090", "TD-2090-60M" manufactured by DIC Corporation, etc.

Examples of the acid anhydride curing agent include those having one or more acid anhydride groups in one molecule, and preferably those having two or more acid anhydride groups in one molecule. Specific examples of the acid anhydride curing agent include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnorbornenic anhydride, hydrogenated methylnorbornenic anhydride, trialkyltetrahydrophthalic anhydride, dodecenylsuccinic anhydride, 5-(2,5-dihydroxytetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, diphenyl Ketone tetracarboxylic dianhydride, biphenyl tetracarboxylic dianhydride, naphthalene tetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenylsulfonium tetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxy-3-furanyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(dehydrated trimellitic acid ester), styrene/maleic acid resin copolymerized with maleic acid, etc. Polymer type anhydrides, etc. Commercially available products of anhydride-based hardeners include "HNA-100" and "MH-700" manufactured by Shin Nippon Rika Co., Ltd.

There is no particular limitation on the active ester curing agent. Generally, it is preferred to use a compound having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxylamine esters, and esters of heterocyclic hydroxyl compounds. The active ester curing agent is preferably obtained by a condensation reaction of a carboxylic acid compound and/or a thiocarboxylic acid compound with a hydroxyl compound and/or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester curing agent obtained from a carboxylic acid compound and a hydroxyl compound is preferred; and an active ester curing agent obtained from a carboxylic acid compound and a phenolic compound and/or a naphthol compound is more preferred. Examples of carboxylic acid compounds include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of the phenolic compound or naphthol compound include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, pyrogallol, dicyclopentadiene-type diphenolic compounds, phenol novolac, etc. Here, "dicyclopentadiene-type diphenolic compounds" refers to diphenolic compounds obtained by condensing two molecules of phenol with one molecule of dicyclopentadiene.

Specifically, preferred are active ester compounds containing a dicyclopentadiene type diphenol structure, active ester compounds containing a naphthalene structure, active ester compounds containing acetylated phenol novolacs, and active ester compounds containing benzoylated phenol novolacs, and more preferred are active ester compounds containing a naphthalene structure and active ester compounds containing a dicyclopentadiene type diphenol structure. "Dicyclopentadiene type diphenol structure" refers to a divalent structural unit containing phenylene-dicyclopentalene-phenylene.

As commercially available active ester curing agents, for active ester compounds containing a dicyclopentadiene-type diphenol structure, there are "EXB9451", "EXB9460", "EXB9460S", "HPC-8000", "HPC-8000H", "HPC-8000-65T", "HPC-8000H-65TM", "EXB-8000L", "EXB-8000L-65M", "EXB-8000L-65TM" (manufactured by DIC Corporation); for active ester compounds containing a naphthalene structure, there are Examples include "EXB-9416-70BK", "EXB-8150-65T", "EXB-8100L-65T", and "EXB-8150L-65T" (manufactured by DIC Corporation); as for active ester hardeners of acetylated phenol novolacs, "DC808" (manufactured by Mitsubishi Chemical Corporation) can be cited; as for active ester hardeners of benzoylated phenol novolacs, "YLH1026" (manufactured by Mitsubishi Chemical Corporation), "YLH1030" (manufactured by Mitsubishi Chemical Corporation), and "YLH1048" (manufactured by Mitsubishi Chemical Corporation) can be cited.

Specific examples of benzoxazine-based hardeners include "JBZ-OP100D" and "ODA-BOZ" manufactured by JFE Chemicals, "HFB2006M" manufactured by Showa High Polymer, and "P-d" and "F-a" manufactured by Shikoku Chemicals.

Cyanate curing agents include, for example, bisphenol A dicyanate, polyphenol cyanate (oligo(3-methylene-1,5-phenylene cyanate)), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylenediphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanatephenylmethane) , bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylidene))benzene, bis(4-cyanatephenyl)sulfide, and bis(4-cyanatephenyl)ether; polyfunctional cyanate resins derived from phenol novolac and cresol novolac, and prepolymers of these cyanate resins partially triazone-treated. Specific examples of cyanate curing agents include "PT30" and "PT60" manufactured by Lonza Japan (both are phenol novolac-type polyfunctional cyanate resins), "BA230", "BA230S75" (prepolymers of bisphenol A dicyanate partially or completely triazone-treated to become trimers), etc.

When the resin composition contains (D) epoxy resin and (E) hardener, the amount ratio of (D) epoxy resin to (E) hardener is preferably 1:0.2 to 1:2, more preferably 1:0.3 to 1:1.5, and even more preferably 1:0.4 to 1:1.4, in terms of [number of epoxy groups of (D) epoxy resin]:[number of reactive groups of (E) hardener]. Here, the reactive group of (E) hardener is, for example, an aromatic hydroxyl group in the case of a phenolic hardener or a naphthol hardener, or an active ester group in the case of an active ester hardener, depending on the type of hardener.

(E) The reactive group equivalent of the curing agent is preferably 50 g/eq. to 3,000 g/eq., more preferably 100 g/eq. to 1,000 g/eq., still more preferably 100 g/eq. to 500 g/eq., and particularly preferably 100 g/eq. to 300 g/eq. The reactive group equivalent is the mass of the curing agent per 1 equivalent of reactive group.

When the (E) hardener contains an active ester hardener, the content thereof is not particularly limited, but is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, and particularly preferably 40% by mass or more, based on the total amount of the (E) hardener being 100% by mass.

The content of the (E) hardener in the resin composition is not particularly limited, and when the non-volatile components in the resin composition are 100% by mass, it is preferably 50% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, even more preferably 15% by mass or less, and particularly preferably 10% by mass or less. The lower limit of the content of the (E) hardener in the resin composition is not particularly limited, and when the non-volatile components in the resin composition are 100% by mass, it is, for example, 0% by mass or more, 0.01% by mass or more; preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 2% by mass or more, even more preferably 4% by mass or more, and particularly preferably 5% by mass or more.

<(F) Hardening accelerator> The resin composition of the present invention may contain (F) hardening accelerator as an optional component. (F) Hardening accelerator has the function of accelerating the hardening of (D) epoxy resin.

(F) The hardening accelerator is not particularly limited, and examples thereof include phosphorus-based hardening accelerators, urea-based hardening accelerators, amine-based hardening accelerators, imidazole-based hardening accelerators, guanidine-based hardening accelerators, and metal-based hardening accelerators. Among them, phosphorus-based hardening accelerators, amine-based hardening accelerators, imidazole-based hardening accelerators, and metal-based hardening accelerators are preferred; amine-based hardening accelerators and imidazole-based hardening accelerators are particularly preferred. The hardening accelerators may be used alone or in combination of two or more.

Phosphorus-based hardening accelerators include, for example, tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, di(tetrabutylphosphonium)benzene tetracarboxylate, tetrabutylphosphonium hexahydrophthalate, tetrabutylphosphonium cresol novolac trimer salt, di-tert-butyl aliphatic phosphonium salts such as methyl phosphonium tetraphenyl borate; methyl triphenyl phosphonium bromide, ethyl triphenyl phosphonium bromide, propyl triphenyl phosphonium bromide, butyl triphenyl phosphonium bromide, benzyl triphenyl phosphonium chloride, tetraphenyl phosphonium bromide, p-tolyl triphenyl phosphonium tetra-p-tolyl borate, tetraphenyl phosphonium tetraphenyl borate Aromatic phosphonium salts such as tetraphenylphosphonium tetra-p-tolyl borate, triphenylethylphosphonium tetraphenylborate, tris(3-methylphenyl)ethylphosphonium tetraphenylborate, tris(2-methoxyphenyl)ethylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate; aromatic phosphine/borane complexes such as triphenylphosphine/triphenylborane; aromatic phosphine/quinone addition reactants such as triphenylphosphine/p-benzoquinone addition reactants; tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, di-tert-butyl(2-butenyl)phosphine, di-tetraphenylphosphine, tri-tert-butyl(2-butenyl) ... aliphatic phosphines such as tert-butyl(3-methyl-2-butenyl)phosphine, tricyclohexylphosphine, etc.; dibutylphenylphosphine, di-tert-butylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, butyldiphenylphosphine, diphenylcyclohexylphosphine, triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tris(4-ethylphenyl)phosphine, tris(4-propylphenyl)phosphine, tris(4-isopropylphenyl)phosphine, tris(4-butylphenyl)phosphine, tris(4-tert-butylphenyl)phosphine, tris(2,4-dimethylphenyl)phosphine, tris(2,5-dimethylphenyl)phosphine, tris(2,6- Aromatic phosphines such as tris(2,4-dimethylphenyl)phosphine, tris(3,5-dimethylphenyl)phosphine, tris(2,4,6-trimethylphenyl)phosphine, tris(2,6-dimethyl-4-ethoxyphenyl)phosphine, tris(2-methoxyphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(4-ethoxyphenyl)phosphine, tris(4-tert-butoxyphenyl)phosphine, diphenyl-2-pyridylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, 1,2-bis(diphenylphosphino)acetylene, and 2,2'-bis(diphenylphosphino)diphenyl ether.

Urea-based hardening accelerators include, for example, 1,1-dimethylurea; aliphatic dimethylureas such as 1,1,3-trimethylurea, 3-ethyl-1,1-dimethylurea, 3-cyclohexyl-1,1-dimethylurea, and 3-cyclooctyl-1,1-dimethylurea; 3-phenyl-1,1-dimethylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3-(3-chloro-4-methylphenyl)-1,1-dimethylurea, 3-(2-methylphenyl)-1,1-dimethylurea, 3-(4-methylphenyl)-1,1-dimethylurea, 3-(3,4-dimethylphenyl)-1,1-dimethylurea; Aromatic dimethylureas such as dimethylurea, 3-(4-isopropylphenyl)-1,1-dimethylurea, 3-(4-methoxyphenyl)-1,1-dimethylurea, 3-(4-nitrophenyl)-1,1-dimethylurea, 3-[4-(4-methoxyphenoxy)phenyl]-1,1-dimethylurea, 3-[4-(4-chlorophenoxy)phenyl]-1,1-dimethylurea, 3-[3-(trifluoromethyl)phenyl]-1,1-dimethylurea, N,N-(1,4-phenylene)bis(N’,N’-dimethylurea), N,N-(4-methyl-1,3-phenylene)bis(N’,N’-dimethylurea) [toluenebisdimethylurea], etc.

Examples of the amine-based hardening accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine (DMAP), benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, etc., preferably 4-dimethylaminopyridine.

Examples of imidazole hardening accelerators include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazole trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-trimethylol 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazolyl isocyanuric acid adduct imidazole compounds such as 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, 2-phenylimidazoline, and adducts of imidazole compounds with epoxy resins.

As the imidazole-based hardening accelerator, a commercially available product may be used, for example, "P200-H50" manufactured by Mitsubishi Chemical Corporation.

Examples of guanidine-based hardening accelerators include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanidine, 1-ethylbiguanidine, 1-n-butylbiguanidine, 1-n-octadecylbiguanidine, 1,1-dimethylbiguanidine, 1,1-diethylbiguanidine, 1-cyclohexylbiguanidine, 1-allylbiguanidine, 1-phenylbiguanidine, and 1-(o-tolyl)biguanidine.

Examples of metal hardening accelerators include organic metal complexes or organic metal salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organic metal complexes include organic cobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, organic copper complexes such as copper (II) acetylacetonate, organic zinc complexes such as zinc (II) acetylacetonate, organic iron complexes such as iron (III) acetylacetonate, organic nickel complexes such as nickel (II) acetylacetonate, and organic manganese complexes such as manganese (II) acetylacetonate. Examples of the organic metal salt include zinc octylate, tin octylate, zinc cycloalkanoate, cobalt cycloalkanoate, tin stearate, zinc stearate, and the like.

The content of the (F) hardening accelerator in the resin composition is not particularly limited, and is preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 3% by mass or less, still more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less, based on 100% by mass of the non-volatile components in the resin composition. The lower limit of the content of the (F) hardening accelerator in the resin composition is not particularly limited, and is, for example, 0% by mass or more, 0.0001% by mass or more, preferably 0.001% by mass or more, more preferably 0.005% by mass or more, still more preferably 0.01% by mass or more, still more preferably 0.05% by mass or more, and particularly preferably 0.1% by mass or more, based on 100% by mass of the non-volatile components in the resin composition.

<(G) Other additives> The resin composition of the present invention may further contain any additive as a non-volatile component. Examples of such additives include organic fillers such as rubber particles, polyamide particles, and polysilicone particles; thermoplastic resins such as phenoxy resins, polyvinyl acetal resins, polyolefin resins, polysulfide resins, polyethersulfide resins, polyphenylene ether resins, polycarbonate resins, polyetheretherketone resins, and polyester resins; organic copper compounds, organic zinc compounds, and organic Organic metal compounds such as cobalt compounds; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, carbon black, etc.; polymerization inhibitors such as hydroquinone, catechol, gallic acid, phenothiazine, etc.; leveling agents such as polysilicone leveling agents and acrylic polymer leveling agents; thickening agents such as Benton (bentonite) and montmorillonite; polysilicone Defoaming agents, acrylic defoaming agents, fluorine defoaming agents, vinyl resin defoaming agents; UV absorbers such as benzotriazole UV absorbers; adhesion enhancers such as urea silane; adhesion enhancers such as triazole adhesion enhancers, tetrazole adhesion enhancers, triazine adhesion enhancers; hindered phenol antioxidants, hindered amine antioxidants Antioxidants such as stilbene derivatives, etc.; Fluorescent brighteners such as fluorine-based surfactants and polysilicone-based surfactants; Flame retardants such as phosphorus-based flame retardants (such as phosphate esters, hypophosphites, phosphazene compounds, and red phosphorus), nitrogen-based flame retardants (such as melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (such as antimony trioxide). The additives may be used alone or in combination of two or more in any ratio. (G) The content of other additives may be appropriately set by a person having ordinary knowledge in the relevant technical field.

<(H) Organic solvent> The resin composition of the present invention may contain any organic solvent as a volatile component in addition to the above-mentioned non-volatile component. (H) The organic solvent may be any known organic solvent, and its type is not particularly limited. (H) Organic solvents include, for example, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, and diphenyl ether; alcohol solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, methoxypropionic acid methyl ester; esters, etc.; ester alcohol solvents, such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether alcohol solvents, such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); amide solvents, such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfoxide solvents, such as dimethyl sulfoxide; nitrile solvents, such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents, such as hexane, cyclopentane, cyclohexane, and methylcyclohexane; aromatic hydrocarbon solvents, such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene. (H) Organic solvents may be used alone or in combination of two or more in any ratio.

<Manufacturing method of resin composition>

The resin composition of the present invention can be produced, for example, by adding part or all of (A) polyimide resin (preliminarily imidized), (B) carbodiimide resin, (C) inorganic filler, (D) epoxy resin as required, (E) hardener as required, (F) hardening accelerator as required, (G) other additives as required, and (H) organic solvent as required in any reaction container in any order and/or simultaneously, and mixing them. In addition, during the process of adding and mixing the components, the temperature can be appropriately set, and heating and/or cooling can be performed temporarily or all the time. In addition, during the process of adding and mixing the components, stirring or vibration can also be performed. Furthermore, when adding and mixing or thereafter, the resin composition may be stirred using a stirring device such as a mixer to make it uniformly dispersed.

<Characteristics of resin composition>

The resin composition of the present invention contains (A) polyimide resin, (B) carbodiimide resin, and (C) inorganic filler, and the content of component (C) is less than 40% by mass. Therefore, a hardened material can be obtained which can suppress the halo phenomenon and has excellent heat resistance and flexibility.

The cured product of the resin composition of the present invention can suppress the halo phenomenon, so for example, the halo ratio calculated as in the following test example 1 is preferably less than 40%, more preferably less than 35%, even more preferably less than 30%, and particularly preferably less than 25%.

The cured product of the resin composition of the present invention has excellent heat resistance. For example, as shown in the following Test Example 2, the change rate of the elongation at break of the cured product before and after the high temperature treatment at 200°C for 5 hours (obtained by formula (1) in Test Example 2) is preferably 50% or more, more preferably 60% or more, even more preferably 70% or more, and particularly preferably 80% or more.

The cured product of the resin composition of the present invention has excellent flexibility, so the number of folding times after the MIT folding test as described in Test Example 3 below is preferably more than 3,000 times, more preferably more than 5,000 times, more preferably more than 8,000 times, and particularly preferably more than 10,000 times.

<Uses of resin compositions>

The resin composition of the present invention can be used in a wide range of applications such as insulating materials, solder resists, primers, die bonding materials, semiconductor sealing materials, via-filling resins, and component embedding resins for printed circuit boards, multi-layer flexible substrates, etc. Printed circuit boards, multi-layer flexible substrates, etc. can be manufactured using, for example, thin sheet-like laminated materials such as resin sheets and prepregs.

<Resin sheet> The resin sheet of the present invention comprises a support body and a resin composition layer formed by the resin composition of the present invention and disposed on the support body.

The thickness of the resin composition layer is preferably 200 μm or less, more preferably 150 μm or less, even more preferably 100 μm or less, and particularly preferably 70 μm or less. The lower limit of the thickness of the resin composition layer is not particularly limited, and can usually be 1 μm or more, 1.5 μm or more, 2 μm or more, etc.

Examples of the support include films made of plastic materials, metal foils, and release paper, and films made of plastic materials and metal foils are preferred.

When a film containing a plastic material is used as a support, the plastic material may be, for example, polyesters such as polyethylene terephthalate (hereinafter referred to as "PET") and polyethylene naphthalate (hereinafter referred to as "PEN"), acrylics such as polycarbonate (hereinafter referred to as "PC") and polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, polyimide, etc. Among them, polyethylene terephthalate and polyethylene naphthalate are preferred, and polyethylene terephthalate, which is inexpensive, is particularly preferred.

When a metal foil is used as the support, the metal foil may be, for example, copper foil, aluminum foil, etc., preferably copper foil. As the copper foil, a single metal foil containing copper may be used, or an alloy foil containing copper and other metals (such as tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used.

The surface of the support body that is bonded to the resin composition layer may also be subjected to matte treatment, corona treatment, and anti-static treatment.

Furthermore, as the support, a support with a release layer having a release layer on the surface bonded to the resin composition layer may be used. The release agent used for the release layer of the support with a release layer may be, for example, one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. The support body with a release layer may be a commercially available product. For example, there may be PET films having a release layer with an alkyd resin release agent as the main component, such as "SK-1", "AL-5", and "AL-7" manufactured by Lintec, "Lumirror T60" manufactured by Toray, "Purex" manufactured by Teijin, and "Unipeel" manufactured by Unitika.

The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, and more preferably in the range of 10 μm to 60 μm. Furthermore, when a support with a release layer is used, the thickness of the entire support with a release layer is preferably in the above range.

In one embodiment, the resin sheet may further include other layers as needed. Such other layers may include, for example, a protective film that is provided on the surface of the resin composition layer that is not bonded to the support body (i.e., the surface opposite to the support body) and is equivalent to the support body. The thickness of the protective film is not particularly limited, and is, for example, 1 μm to 40 μm. By laminating the protective film, dust and the like can be prevented from adhering to or scratching the surface of the resin composition layer.

The resin sheet can be manufactured by applying the resin composition directly or, for example, a resin coating prepared by dissolving the resin composition in an organic solvent, onto a support using a die coater or the like, and further drying to form a resin composition layer.

The organic solvents that can be used when applied to the support include, for example, the same ones as those listed in the description of the organic solvents as components of the resin composition. The organic solvents may be used alone or in combination of two or more.

Drying can be carried out by known methods such as heating and hot air blowing. The drying conditions are not particularly limited, and the drying is carried out in such a manner that the content of the organic solvent in the resin composition layer becomes less than 10 mass %, preferably less than 5 mass %. Although it also varies depending on the boiling point of the organic solvent in the resin composition or resin coating, for example, when a resin composition or resin coating containing 30 mass % to 60 mass % of an organic solvent is used, the resin composition layer can be formed by drying at 50°C to 150°C for 3 minutes to 10 minutes.

The resin sheet can be stored by being rolled into a roll. If the resin sheet has a protective film, it can be used by peeling off the protective film.

<Laminated sheet> The laminated sheet may be a sheet produced by laminating and curing a plurality of resin composition layers. The laminated sheet includes a plurality of insulating layers which are cured products of the resin composition layers. Usually, the number of resin composition layers laminated to produce the laminated sheet is consistent with the number of insulating layers included in the laminated sheet. The specific number of insulating layers per laminated sheet is usually 2 or more, preferably 3 or more, particularly preferably 5 or more; preferably 20 or less, more preferably 15 or less, particularly preferably 10 or less.

The laminated sheet may be a sheet that is used by folding one side of the laminated sheet in a manner that the two sides thereof are mutually opposed. The minimum bending radius of the folded laminated sheet is not particularly limited, but is preferably 0.1 mm or more, more preferably 0.2 mm or more, and even more preferably 0.3 mm or more; preferably 5 mm or less, more preferably 4 mm or less, and particularly preferably 3 mm or less.

Holes may also be formed on each insulating layer included in the laminate sheet, and the holes may function as through holes or through-holes in the multi-layer flexible substrate.

The laminate sheet may further include arbitrary elements in addition to the insulating layer. For example, the laminate sheet may also have a conductive layer as an arbitrary element. The conductive layer is usually formed on the surface of the insulating layer or partially between the insulating layers. The conductive layer usually functions as a wiring in a multi-layer flexible substrate.

The conductive material used for the conductive layer is not particularly limited. In a suitable embodiment, the conductive layer includes one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin and indium. The conductive material may be a single metal or an alloy. The alloy may be, for example, an alloy of two or more metals selected from the above group (e.g., nickel/chromium alloy, copper/nickel alloy and copper/titanium alloy). Among them, from the viewpoints of versatility, cost, and ease of patterning in forming the conductive layer, single metals such as chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, and alloys such as nickel/chromium alloys, copper/nickel alloys, and copper/titanium alloys are preferred. Among them, single metals such as chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, and nickel/chromium alloys are more preferred, and single metals such as copper are more preferred.

The conductive layer may be a single layer structure or a composite structure including two or more single metal layers or alloy layers containing different types of metals or alloys. When the conductive layer is a composite structure, the layer adjacent to the insulating layer is preferably a single metal layer of chromium, zinc or titanium, or an alloy layer of nickel/chromium alloy.

The conductive layer may also be patterned in order to function as wiring.

The thickness of the conductive layer varies depending on the design of the multi-layer flexible substrate, but is preferably 3 μm to 35 μm, more preferably 5 μm to 30 μm, even more preferably 10 μm to 20 μm, and particularly preferably 15 μm to 20 μm.

The thickness of the laminated sheet is preferably 100 μm or more, more preferably 150 μm or more, particularly preferably 200 μm or more; preferably 2,000 μm or less, more preferably 1,000 μm or less, particularly preferably 500 μm or less.

<Method for producing laminated sheet> The laminated sheet can be produced by a production method comprising (a) preparing a resin sheet, and (b) laminating and curing a plurality of resin composition layers using the resin sheet. The order of laminating and curing the resin composition layers is arbitrary as long as the desired laminated sheet can be obtained. For example, after laminating all the plurality of resin composition layers, the laminated plurality of resin composition layers can be cured at once, depending on the components contained in the resin composition. Furthermore, for example, whenever another resin composition layer is laminated on a certain resin composition layer, the laminated resin composition layer may be hardened.

A preferred embodiment of step (b) is described below. In the embodiments described below, for the purpose of distinction, the resin composition layers are appropriately numbered with "first resin composition layer" and "second resin composition layer", and further, the insulating layers obtained by hardening the resin composition layers are also numbered with "first insulating layer" and "second insulating layer" in the same manner as the resin composition layers.

In a preferred embodiment, step (b) includes (II) hardening the first resin composition layer to form a first insulating layer, (VI) laminating the second resin composition layer on the first insulating layer, and (VII) hardening the second resin composition layer to form a second insulating layer. Furthermore, step (b) may also include any of the following steps as needed: (I) laminating a first resin composition layer on a thin sheet support substrate, (III) opening holes in the first insulating layer, (IV) roughening the first insulating layer, (V) forming a conductor layer on the first insulating layer, etc. Each step is described below.

Step (I) is a step of laminating a first resin composition layer on a thin sheet support substrate before step (II). The thin sheet support substrate is a removable member, for example, a plate, sheet or film-shaped member.

The lamination of the sheet support substrate and the first resin composition layer can be performed by vacuum lamination. In the vacuum lamination, the heating and pressing temperature is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C, the heating and pressing pressure is preferably in the range of 0.098MPa to 1.77MPa, more preferably in the range of 0.29MPa to 1.47MPa, and the heating and pressing time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. The lamination is preferably performed under reduced pressure conditions with a pressure of less than 26.7hPa.

Lamination can be performed by a commercially available vacuum laminator. Examples of commercially available vacuum laminators include a vacuum pressurizing laminator manufactured by Nobuaki Masakōsho, a vacuum applicator manufactured by Nikko Materials, and a batch vacuum pressurizing laminator.

When a resin sheet is used, the sheet support substrate and the first resin component layer can be laminated, for example, by pressing the resin sheet from the side of the support body and heating and pressing the first resin component layer of the resin sheet to the sheet support substrate. The member for heating and pressing the resin sheet to the sheet support substrate (hereinafter also appropriately referred to as "heating and pressing member") can be, for example, a heated metal plate (SUS mirror plate, etc.) or a metal roller (SUS roller). It is preferred that the first resin component layer be pressed by an elastic material such as heat-resistant rubber in such a way that the first resin component layer fully follows the surface irregularities of the sheet support substrate, rather than directly pressing the heated and pressed member on the resin sheet.

After lamination, the first resin component layer can also be smoothed by applying pressure under normal pressure (atmospheric pressure), for example, by using a heating and pressing member. For example, when a resin sheet is used, the first resin component layer of the resin sheet can be smoothed by applying pressure to the resin sheet from the side of the support body using a heating and pressing member. The pressurizing conditions for the smoothing treatment can be the same as the heating and pressing conditions for the above-mentioned lamination. The smoothing treatment can be performed by a commercially available laminating machine. The lamination and smoothing treatment can also be performed continuously using the above-mentioned commercially available vacuum laminating machine.

Step (II) is a step of hardening the first resin composition layer to form a first insulating layer. The hardening conditions of the first resin composition layer are not particularly limited, and the conditions used when forming the insulating layer of a printed circuit board can be arbitrarily applied. When the first resin composition layer contains a thermosetting resin, for example, it can be hardened by heat curing.

Generally, the specific heat curing conditions vary depending on the type of thermosetting resin. For example, the curing temperature is preferably 120°C to 240°C, more preferably 150°C to 220°C, and even more preferably 170°C to 210°C. Moreover, the curing time is preferably 5 minutes to 120 minutes, more preferably 10 minutes to 110 minutes, and even more preferably 20 minutes to 100 minutes.

Before the first resin composition layer is heat-cured, the first resin composition layer may be pre-heated at a temperature lower than the curing temperature. For example, before the first resin composition layer is heat-cured, the first resin composition layer may be pre-heated at a temperature of 50°C or higher and lower than 120°C (preferably 60°C or higher and 115°C or lower, more preferably 70°C or higher and 110°C or lower) for 5 minutes or more (preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes).

Step (III) is a step of opening holes in the first insulating layer. Through step (III), holes such as via holes and through holes can be formed in the first insulating layer. The opening can be performed by, for example, using a drill, laser, plasma, etc., depending on the composition of the resin composition. The size and shape of the hole can be appropriately set according to the design of the multi-layer flexible substrate.

Step (IV) is a step of roughening the first insulating layer. Usually, in step (IV), the scum is also removed. Therefore, the roughening treatment is also called the scum removal treatment. Examples of the roughening treatment include a swelling treatment with a swelling liquid, a roughening treatment with an oxidizing agent, and a neutralization treatment with a neutralizing liquid.

The swelling liquid is not particularly limited, and examples thereof include alkaline aqueous solutions such as sodium hydroxide aqueous solution and potassium hydroxide aqueous solution. Examples of commercially available swelling liquids include "Swelling Dip Securiganth P" and "Swelling Dip Securiganth SBU" manufactured by Atotech Japan. The swelling treatment with the swelling liquid can be performed, for example, by immersing the hardened body in a swelling liquid at 30 to 90°C for 1 to 20 minutes. From the viewpoint of suppressing the swelling of the resin of the insulating layer to an appropriate level, it is preferred to immerse the insulating layer in a swelling liquid at 40 to 80°C for 5 to 15 minutes.

The oxidizing agent is not particularly limited, and examples thereof include an aqueous sodium hydroxide solution and an alkaline permanganic acid solution in which permanganate is dissolved in an aqueous potassium hydroxide solution. The concentration of permanganate in the alkaline permanganic acid solution is preferably 5 mass % to 10 mass %. Commercially available oxidizing agents include alkaline permanganic acid solutions such as "Concentrate Compact P", "Concentrate Compact CP", and "Dosing solution Securiganth P" manufactured by Atotech Japan. Roughening treatment with an oxidizing agent can be performed by immersing the hardened body in an oxidizing agent solution heated to 60°C to 80°C for 10 minutes to 30 minutes.

In addition, an acidic aqueous solution can be used as the neutralizing solution. An example of a commercially available product is "Reduction solution Securiganth P" manufactured by Atotech Japan. The treatment with the neutralizing solution can be performed by immersing the hardened body in a neutralizing solution at 30°C to 80°C for 5 to 30 minutes. From the viewpoint of workability, it is preferred to immerse the hardened body in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes.

The arithmetic average roughness (Ra) of the surface of the first insulating layer after the roughening treatment is preferably 400 nm or less, more preferably 300 nm or less, and even more preferably 200 nm or less. The lower limit is not particularly limited, and may be 30 nm or more, 40 nm or more, or 50 nm or more.

Step (V) is a step of forming a conductive layer on the first insulating layer as required. The conductive layer can be formed by, for example, coating, sputtering, evaporation, etc., of which coating is particularly preferred. Suitable examples include a method of coating the surface of the first insulating layer by a suitable method such as a semi-additive method or a full-additive method to form a conductive layer having a desired wiring pattern. Of these, the semi-additive method is particularly preferred from the perspective of simplicity of manufacturing.

The following is an example of forming a conductive layer by a semi-additive method. First, a plating seed layer is formed on the surface of the first insulating layer by electroless plating. Then, a mask pattern is formed on the formed plating seed layer to expose a portion of the plating seed layer corresponding to the desired wiring pattern. After a metal layer is formed on the exposed plating seed layer by electrolytic plating, the mask pattern is removed. Thereafter, the unnecessary plating seed layer is removed by etching or the like, and a conductive layer having the desired wiring pattern can be formed.

After obtaining the first insulating layer in step (II), step (III), step (IV), and step (V) are performed as needed, and then step (VI) is performed. Step (VI) is a step of laminating a second resin composition layer on the first insulating layer. The lamination of the first insulating layer and the second resin composition layer can be performed by the same method as the lamination of the sheet support substrate and the first resin composition layer in step (I).

However, when the resin sheet is used to form the first resin composition layer, the support of the resin sheet is removed before step (VI). The support can be removed between step (I) and step (II), between step (II) and step (III), between step (III) and step (IV), or between step (IV) and step (V).

After step (VI), step (VII) is performed. Step (VII) is a step of hardening the second resin composition layer to form a second insulating layer. The hardening of the second resin composition layer can be performed by the same method as the hardening of the first resin composition layer in step (II). In this way, a laminated sheet including a plurality of insulating layers including a first insulating layer and a second insulating layer can be obtained.

In addition, in the method of the above-mentioned embodiment, the step (VIII) of opening a hole in the second insulating layer, the step (IX) of roughening the second insulating layer, and the step (X) of forming a conductive layer on the second insulating layer may be performed as needed. The opening of the second insulating layer in step (VIII) may be performed by the same method as the opening of the first insulating layer in step (III). In addition, the roughening of the second insulating layer in step (IX) may be performed by the same method as the roughening of the first insulating layer in step (IV). Furthermore, the formation of the conductive layer on the second insulating layer in step (X) can be performed by the same method as the formation of the conductive layer on the first insulating layer in step (V).

In the above-mentioned embodiments, the laminated sheet is manufactured by laminating and curing two resin composition layers, namely the first resin composition layer and the second resin composition layer. However, the laminated sheet can also be manufactured by laminating and curing three or more resin composition layers. For example, in the method of the above-mentioned embodiments, the laminated sheet can also be manufactured by repeatedly laminating and curing the resin composition layers in steps (VI) to (VII), and, if necessary, performing opening of the insulating layer, roughening of the insulating layer, and forming of the conductor layer on the insulating layer in steps (VIII) to (X). In this way, a laminated sheet including three or more insulating layers can be obtained.

Furthermore, the method of the aforementioned embodiment may also include any steps other than the aforementioned steps. For example, after performing step (I), a step of removing the sheet support substrate may also be performed.

<Multi-layer flexible substrate> The multi-layer flexible substrate includes a laminate sheet. The multi-layer flexible substrate may include only the laminate sheet or may include any component combined with the laminate sheet. The arbitrary component may include, for example, electronic components, a coverlay film, etc.

The multi-layered flexible substrate can be manufactured by a manufacturing method including the method of manufacturing the above-mentioned laminated sheet. Therefore, the multi-layered flexible substrate can be manufactured by a manufacturing method including (a) the step of preparing a resin sheet, and (b) the step of laminating a plurality of resin composition layers using the resin sheet and curing the layers.

The method for manufacturing a multi-layer flexible substrate may further include any steps combined with the aforementioned steps. For example, the method for manufacturing a multi-layer flexible substrate having electronic components may include the step of bonding the electronic components to the laminated sheet. The bonding conditions between the laminated sheet and the electronic components may be any conditions that allow the terminal electrodes of the electronic components to be conductively connected to the conductive layer as the wiring provided on the laminated sheet. Furthermore, for example, the method for manufacturing a multi-layer flexible substrate having a covering film may include the step of bonding the laminated sheet to the covering film.

The aforementioned multi-layer flexible substrate can usually be used by being folded in a manner that the surfaces of the laminated sheets included in the multi-layer flexible substrate are mutually opposed. For example, the multi-layer flexible substrate is stored in a housing of a semiconductor device in a state where the multi-layer flexible substrate is folded to reduce the size. In another example, the multi-layer flexible substrate is provided in a movable portion of a semiconductor device having a foldable movable portion.

<Semiconductor device> A semiconductor device having the aforementioned multi-layer flexible substrate. The semiconductor device, for example, has a multi-layer flexible substrate and a semiconductor chip mounted on the multi-layer flexible substrate. In many semiconductor devices, the multi-layer flexible substrate can be folded and stored in a housing of the semiconductor device in a manner such that the surfaces of one side of the laminated sheets included in the multi-layer flexible substrate face each other.

Examples of semiconductor devices include various semiconductor devices used in electrical products (such as computers, mobile phones, digital cameras, and televisions) and transportation vehicles (such as motorcycles, cars, trains, ships, and aircrafts).

The aforementioned semiconductor device can be manufactured by a manufacturing method including the steps of preparing a multi-layer flexible substrate, bending the multi-layer flexible substrate in a manner such that the surfaces of one side of the laminated sheet are opposite to each other, and housing the bent multi-layer flexible substrate in a housing. [Example]

The present invention is specifically described below by way of examples. The present invention is not limited to these examples. Furthermore, in the following, "parts" and "%" indicating amounts, unless otherwise specified, mean "parts by mass" and "% by mass", respectively. Furthermore, the operations described below, unless otherwise specified, are performed at room temperature and pressure (25°C, 1 atm).

<Synthesis Example 1: Synthesis of Polyimide Resin 1> 50 g of G-3000 (bifunctional hydroxyl-terminated polybutadiene, number average molecular weight = 5047 (GPC method), hydroxyl equivalent = 1798 g/eq., solid content 100 mass %: manufactured by Nippon Soda Co., Ltd.) and 23.5 g of Ipzole 150 (aromatic hydrocarbon mixed solvent: manufactured by Idemitsu Petrochemical Co., Ltd.) and 0.005 g of dibutyltin laurate were mixed and dissolved uniformly in a reaction container. When the mixture became uniform, the temperature was raised to 50°C, and further stirred, and 4.8 g of toluene-2,4-diisocyanate (isocyanate equivalent = 87.08 g/eq.) was added, and the mixture was reacted for about 3 hours. Next, the reaction product was cooled to room temperature, and then 8.96 g of benzophenone tetracarboxylic dianhydride (anhydride equivalent = 161.1 g/eq.), 0.07 g of triethylenediamine, and 40.4 g of ethyl diglycol acetate (produced by Daicel) were added thereto. The temperature was raised to 130°C while stirring, and the reaction was carried out for about 4 hours. The disappearance of the NCO peak at 2250 cm ^-1 was confirmed by FTIR. The disappearance of the NCO peak was considered as the end point of the reaction. After the reaction product was cooled to room temperature, it was filtered with a 100 mesh filter cloth to obtain a polyimide resin 1 having an imide skeleton, a urethane skeleton, and a butadiene skeleton. Viscosity: 7.5Pa･s (25℃, E-type viscometer) Acid value: 16.9mgKOH/g Solid content: 50% by mass Number average molecular weight: 13723 Glass transition temperature: -10℃ Content of polybutadiene structure: 50/(50+4.8+8.96)×100= 78.4% by mass

<Synthesis Example 2: Synthesis of Polyimide Resin 2> In a 500 ml separable flask equipped with a nitrogen inlet tube and a stirring device, 9.13 g (30 mmol) of 5-amino-1,1'-biphenyl-2-yl 4-aminobenzoate, 15.61 g (30 mmol) of 4,4'-(4,4'-isopropylidene diphenyloxy) diphthalic anhydride, 94.64 g of N-methyl-2-pyrrolidone, 0.47 g (6 mmol) of pyridine, and 10 g of toluene were added. The imidization reaction was carried out at 180°C for 4 hours under a nitrogen atmosphere while removing toluene from the system during the process, thereby obtaining a polyimide solution containing polyimide resin 2 (non-volatile component 20 mass %). In the polyimide solution, no precipitation of the synthesized polyimide resin 2 was observed. The weight average molecular weight of the polyimide resin 2 was 45,000.

<Synthesis Example 3: Synthesis of Polyimide Resin 3> In a reaction vessel equipped with a stirrer, a water separator, a thermometer, and a nitrogen inlet tube, 65.0 g of aromatic tetracarboxylic dianhydride ("BisDA-1000" manufactured by SABIC Japan, 4,4'-(4,4'-isopropylidene diphenoxy) diphthalic dianhydride), 266.5 g of cyclohexanone, and 44.4 g of methylcyclohexane were added, and the solution was heated to 60°C. Then, 43.7 g of dimer diamine ("PRIAMINE 1075" manufactured by Croda Japan) and 5.4 g of 1,3-bis(aminomethyl)cyclohexane were added dropwise, and an imidization reaction was carried out at 140°C for 1 hour. Thus, a polyimide solution (30 mass % of non-volatile components) containing polyimide resin 3 was obtained. The weight average molecular weight of polyimide resin 3 was 25,000.

<Synthesis Example 4: Synthesis of Polyimide Resin 4> A 500 mL separable flask equipped with a water dosing receiver connected to a circulation cooler, a nitrogen inlet tube, and a stirrer was prepared. 20.3 g of 4,4'-oxydiphthalic anhydride (ODPA), 200 g of γ-butyrolactone, 20 g of toluene, and 29.6 g of 5-(4-aminophenoxy)-3-[4-(4-aminophenoxy)phenyl]-1,1,3-trimethylindane were added to the flask and stirred at 45°C for 2 hours under a nitrogen flow to react. Then, the reaction solution was heated and maintained at about 160°C while azeotropically removing the condensed water and toluene under a nitrogen flow. Confirm that a specific amount of water has accumulated in the water quantitative receiver and that water no longer flows out. After confirmation, the reaction solution is further heated and stirred at 200°C for 1 hour. Thereafter, it is cooled to obtain a polyimide solution (non-volatile component 20% by mass) containing polyimide resin 4 having a 1,1,3-trimethylindane skeleton. The obtained polyimide resin 4 has a repeating unit represented by the following formula (X1) and a repeating unit represented by the following formula (X2). In addition, the weight average molecular weight of the aforementioned polyimide resin 4 is 12,000.

<Example 1: Preparation of Resin Composition 1> A mixed solvent of 5 parts of a bixylenol type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of about 185), 5 parts of a naphthalene type epoxy resin ("ESN475V" manufactured by Nippon Steel & Sumitomo Chemical Corporation, epoxy equivalent of about 332), 10 parts of a bisphenol AF type epoxy resin ("YL7760" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of about 238), 2 parts of a cyclohexane type epoxy resin ("ZX1658GS" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of about 135), 40 parts of the polyimide resin 1 obtained in Synthesis Example 1 (non-volatile components 50 mass %), and 10 parts of cyclohexanone was heated and dissolved while stirring. After cooling to room temperature, 4 parts of a cresol novolac hardener containing a triazine skeleton ("LA3018-50P" manufactured by DIC, a hydroxyl equivalent of about 151, a 2-methoxypropanol solution containing 50% of non-volatile components), 6 parts of an active ester hardener ("EXB-8000L-65M" manufactured by DIC, an active group equivalent of about 220, a MEK solution containing 65% of non-volatile components by mass), and spherical silica ("SC2500SQ" manufactured by Admatechs, an average particle size of 0.5 μm, a specific surface area of 11.2 ^m2) were mixed therewith. /g, with respect to 100 parts of silica, 25 parts of a surface-treated silica with 1 part of N-phenyl-3-aminopropyltrimethoxysilane ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.), 10 parts of a carbodiimide resin ("V-03" manufactured by Nisshinbo Co., Ltd., polycarbodiimide, a toluene solution containing 50% of non-volatile components), and 0.2 parts of an amine-based curing accelerator (4-dimethylaminopyridine (DMAP)) were uniformly dispersed with a high-speed rotary mixer and filtered with a filter cartridge ("SHP020" manufactured by ROKITECHNO Co., Ltd.) to prepare a resin composition 1.

<Example 2: Preparation of Resin Composition 2> Except that 100 parts of polyimide resin 2 (non-volatile component 20 mass %) obtained in Synthesis Example 2 was used instead of 40 parts of polyimide resin 1 (non-volatile component 50 mass %) obtained in Synthesis Example 1, the same operation as in Example 1 was performed to prepare resin composition 2.

<Example 3: Preparation of Resin Composition 3> Except that 66.7 parts of polyimide resin 3 (30% by mass of non-volatile components) obtained in Synthesis Example 3 were used instead of 40 parts of polyimide resin 1 (50% by mass of non-volatile components) obtained in Synthesis Example 1, the same operation as in Example 1 was performed to prepare resin composition 3.

<Example 4: Preparation of Resin Composition 4> Except that 100 parts of polyimide resin 4 (non-volatile component 20 mass %) obtained in Synthesis Example 4 was used instead of 40 parts of polyimide resin 1 (non-volatile component 50 mass %) obtained in Synthesis Example 1, the same operation as in Example 1 was performed to prepare resin composition 4.

<Comparative Example 1: Preparation of Resin Composition 5> The same operation as in Example 1 was performed to prepare Resin Composition 5, except that 10 parts of the carbodiimide resin ("V-03" manufactured by Nisshinbo Co., Ltd., polycarbodiimide, toluene solution containing 50% non-volatile components) of Example 1 was not used.

<Comparative Example 2: Preparation of Resin Composition 6> Except that 66 parts of phenoxy resin ("YX7553BH30" manufactured by Mitsubishi Chemical Corporation, solid content 30% by mass) were used instead of 40 parts of polyimide resin 1 (non-volatile content 50% by mass) obtained in Synthesis Example 1, the same operation as in Example 1 was performed to prepare resin composition 6.

<Test Example 1: Evaluation of the Suppression Characteristics of the Halo Phenomenon> (1) Copper-clad laminate A glass cloth-based epoxy double-sided copper-clad laminate with copper foil layers on both sides was prepared (copper foil thickness 3μm, substrate thickness 0.15mm, "HL832NSF LCA" manufactured by Mitsubishi Gas Chemical Co., Ltd., 255×340mm size) as a copper-clad laminate.

(2) Stacking of resin sheets with supporting bodies The resin sheets with supporting bodies prepared in the examples (resin sheet A or resin sheet B in the comparative example) were stacked on both sides of the copper-clad laminate using a batch vacuum pressurization laminator (2-stage build-up laminator, CVP700, manufactured by Nikko Materials) in such a way that the resin composition layer was adjacent to the copper-clad laminate. The stacking was performed by reducing the pressure for 30 seconds to a pressure of 13 hPa or less, and then pressing at 130°C and a pressure of 0.74 MPa for 45 seconds. Then, hot pressing was performed at 120°C and a pressure of 0.5 MPa for 75 seconds.

(3) Thermal curing of the resin composition layer The copper-clad laminate with the resin composition layer is placed in an oven at 100°C for 30 minutes, and then moved to an oven at 180°C for 30 minutes to thermally cure and form an insulating layer. This is the cured substrate A.

(4) Laser through-hole processing (through-hole formation) Using a _CO2 laser processing machine "605GTWIII(-P)" manufactured by Mitsubishi Electric, laser irradiation was performed from the support to form a through-hole with a top diameter (diameter) of 75μm in the insulating layer. The laser irradiation conditions were mask diameter 1mm, pulse width 16μs, energy 0.2mJ/shot, number of shots 2, and burst mode (10 kHz).

(5) Roughening treatment After the support body of the hardened substrate A with the through hole formed in the insulating layer is peeled off, a desmearing treatment as a roughening treatment is performed. In addition, as the desmearing treatment, the following wet desmearing treatment is performed.

Wet degumming treatment Immerse in a swelling solution ("Swelling Dip Securiganth P" manufactured by Atotech Japan, an aqueous solution of diethylene glycol monobutyl ether and sodium hydroxide at 60°C for 10 minutes, then in an oxidizing solution ("Concentrate Compact CP" manufactured by Atotech Japan, an aqueous solution of potassium permanganate with a concentration of about 6% and sodium hydroxide with a concentration of about 4%) at 80°C for 20 minutes, and finally in a neutralizing solution ("Reduction solution Securiganth P" manufactured by Atotech Japan, an aqueous solution of sulfuric acid) at 40°C for 5 minutes, and then dry at 80°C for 15 minutes. This is used as the roughened substrate A.

(6) Determination of via diameter after desmear treatment The roughened substrate A was subjected to cross-sectional observation using a FIB-SEM composite device ("SMI3050SE" manufactured by SII NanoTechnology). Specifically, the cross section of the laser via was scraped by FIB (focused ion beam), and the via diameter after desmear treatment was measured from the cross-sectional SEM image. The via top diameter after desmear treatment was measured from the cross-sectional SEM images of 5 randomly selected locations of each sample, and the average value was taken as the via top diameter Lt (μm), which is shown in Table 1 below.

(7) Determination of halo distance after roughening treatment The roughened substrate A was observed using an optical microscope ("KH8700" manufactured by Hirox Corporation). Specifically, the insulating layer around the through hole was observed from the top of the roughened substrate A using an optical microscope (CCD). The observation was performed by aligning the focus of the optical microscope with the top of the through hole. As a result of the observation, a halo portion in the shape of a donut was observed around the through hole, where the insulating layer changed color to white, starting from the edge of the through hole top. Therefore, from the observed image, the radius of the top of the through hole (equivalent to the inner radius of the halo part) r1 and the outer radius of the halo part r2 are measured, and the difference r2-r1 between the radius r1 and the radius r2 is calculated as the halo distance from the edge of the top of the through hole at the measurement point.

The above measurement was performed at 5 randomly selected through-holes. Then, the halo distances of the 5 through-holes were averaged and taken as the halo distance Wt (μm) from the edge of the through-hole top of the sample, and are shown in the following Table 1.

Based on the through-hole top diameter Lt and the halo distance Wt, the halo ratio Ht is calculated and shown in the following Table 1. The halo ratio Ht represents the ratio (Wt/(Lt/2)) of the halo distance Wt from the edge of the through-hole top after the roughening treatment to the radius (Lt/2) of the through-hole top of the through-hole after the roughening treatment. If the halo ratio Ht is 35% or less, it is judged as "○", and if the halo ratio Ht is greater than 35%, it is judged as "×".

<Test Example 2: Evaluation of Heat Resistance> (1) Preparation of Evaluation Cured Material The untreated surface of a release PET film ("501010" manufactured by Lintec, thickness 38 μm, 240 mm square) was placed on a glass cloth-based epoxy resin double-sided copper-coated laminate ("R5715ES" manufactured by Matsushita Electric Works, thickness 0.7 mm, 255 mm square) and the release PET film was fixed on all four sides with polyimide adhesive tape (width 10 mm).

The resin sheets (167×107 mm square) with supports prepared in the examples and comparative examples were laminated in the center using a batch vacuum pressure laminator (Nikko Materials, 2-stage build-up laminator, CVP700) in such a way that the resin composition layer and the release surface of the release PET film were adjacent to each other. The lamination process was carried out by reducing the pressure for 30 seconds to a pressure of 13 hPa or less, and then pressing at 100°C and a pressure of 0.74 MPa for 30 seconds.

Next, the support body is peeled off and the resin composition layer is thermally cured at 180°C for 90 minutes.

After thermal curing, the polyimide adhesive tape was peeled off and the cured layer was removed from the glass cloth substrate epoxy resin double-sided copper laminate. The release PET film was further peeled off from the cured layer to obtain a thin sheet of cured product (Evaluation Cured Product A). After the cured layer was further heated at 200°C for 5 hours, it was peeled off from the release PET film in the same manner as the Evaluation Cured Product A to obtain a thin sheet of cured product (Evaluation Cured Product B).

(2) Determination of elongation (fracture elongation) The evaluation hardened materials A and B were cut into dumbbell-shaped No. 1 test pieces to obtain test pieces. The test pieces were subjected to a tensile test of the evaluation hardened materials according to Japanese Industrial Standards (JIS K7127) using a Tensilon universal testing machine (manufactured by A&D Co., Ltd.) to measure their fracture elongation (%) at 23°C. This operation was performed 3 times, and the average values are shown in Table 1 below. The change rate of the average value A of the fracture elongation (%) of the evaluation hardened material A and the average value B of the fracture elongation (%) of the evaluation hardened material B was calculated by the following formula (1). Elongation at break variation rate (%) = {(B-A)/A} × 100   (1) If the elongation at break variation rate is 80% or more, it is evaluated as "○", and if it is less than 80%, it is evaluated as "×".

<Test Example 3: Evaluation of Softness (MIT Folding Resistance)> The evaluation hardened material A obtained in Test Example 2 was cut into test pieces with a width of 15 mm and a length of 110 mm. The MIT test device (MIT folding fatigue tester "MIT-DA" manufactured by Toyo Seiki Seisaku-sho) was used to measure the number of folding times until the hardened body broke according to JIS C-5016 under the test conditions of load 2.5N, bending angle 90 degrees, bending radius 1.0mm, and bending speed 175 times/minute. The test was performed on 5 samples, and the average value of the best 3 points was calculated. When the number of folding times was less than 8,000 times, it was evaluated as "×", and when it was more than 8,000 times, it was evaluated as "○".

The usage amounts of non-volatile components of the resin compositions of the Examples and Comparative Examples, the measurement results of the test examples, the evaluation results, etc. are shown in the following Table 1.

It is known that by using a resin composition containing (A) a polyimide resin, (B) a carbodiimide resin, and (C) an inorganic filler, wherein the content of the component (C) is less than 40% by mass, a cured product having excellent flexibility, anti-halation properties, and heat resistance can be obtained.

Claims (13)

A resin composition comprising (A) a polyimide resin, (B) a carbodiimide resin, (C) an inorganic filler, (D) an epoxy resin and (E) a hardener, wherein, when the non-volatile components in the resin composition are 100% by mass, the content of the component (A) is 15% by mass or more and 35% by mass or less, the content of the component (B) is 3% by mass or more and 15% by mass or less, the content of the component (C) is 20% by mass or more and less than 40% by mass, the content of the component (D) is 10% by mass or more and 35% by mass or less, the content of the component (E) is 2% by mass or more and 15% by mass or less, and the component (E) contains an active ester hardener. The resin composition of claim 1, wherein the weight average molecular weight of component (A) is greater than 1,000 and less than 100,000. The resin composition of claim 1, wherein component (B) is polycarbodiimide. In the resin composition of claim 1, the content of isocyanate groups in the molecule of component (B) is less than 0.2 mass %. The resin composition of claim 1, wherein the mass ratio of component (B) to component (A) (component (B)/component (A)) is greater than 0.1. The resin composition of claim 1, wherein the mass ratio of component (B) to component (A) (component (B)/component (A)) is less than 0.5. The resin composition of claim 1, wherein component (C) is silicon dioxide. In the resin composition of claim 1, the average particle size of component (C) is less than 1 μm. The resin composition of claim 1 is used to form an insulating layer of a multi-layer flexible substrate. A cured product of a resin composition as described in any one of claims 1 to 9. A resin sheet comprising a support body and a resin composition layer formed by a resin composition as described in any one of claims 1 to 9 and disposed on the support body. A multi-layer flexible substrate comprising an insulating layer formed by hardening a resin composition as described in any one of claims 1 to 9. A semiconductor device having a multi-layer flexible substrate as claimed in claim 12.