Polyamide-imide resin

Abstract

To provide a resin which gives a cured product exhibiting excellent dielectric characteristics and heat resistance.SOLUTION: In a polyamide-imide resin, at least one of the main chain terminals is a maleimide group. In one embodiment, the polyamide-imide resin is represented by the following formula (X-4). (In the formula (X-4), n represents an integer of 1 or more; each A independently represents a trivalent organic group; each R independently represents a divalent organic group; and each ring Ar independently represents a C6-10 aromatic carbon ring which may have a substituent selected from C1-10 alkyl groups and C1-10 aryl groups.)SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyamide-imide resin. The present invention further relates to a curable resin, a resin composition, a resin sheet, a prepreg, a cured product, a circuit board, a semiconductor chip package, and a semiconductor device obtained using the polyamide-imide resin, as well as a method for producing the polyamide-imide resin. [Background technology]

[0002] Resin compositions containing a curable resin such as a maleimide resin or an epoxy resin and a curing agent for the resin produce cured products with excellent insulating properties, heat resistance, adhesion, etc., and have therefore been widely used as materials for electronic components such as semiconductor chip packages and printed wiring boards. For example, Patent Document 1 describes a thermosetting resin composition containing a maleimide compound of a specific structure having a melting point of 40°C or less, an epoxy compound, a cyanate ester compound, and an inorganic filler. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-010964 Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, in high-speed communications such as the fifth-generation mobile communications system (5G), transmission loss becomes an issue when operating in a high-frequency environment. This requires insulating materials with excellent dielectric properties (low dielectric constant, low dielectric dissipation factor). Furthermore, electronic components tend to generate more heat when operating in a high-frequency environment, so insulating materials used in high-speed communications applications must also have improved heat resistance.

[0005] The resin composition described in Patent Document 1 has an improved glass transition temperature (heat resistance) of the cured product compared to conventional resin compositions, but it is still not at a satisfactory level, and there is no mention of the dielectric properties.

[0006] The present invention has been made in view of the above problems, and has an object to provide a resin that provides a cured product exhibiting excellent dielectric properties and heat resistance. [Means for solving the problem]

[0007] As a result of extensive research, the present inventors have found that the above problems can be solved by using a polyamide-imide resin in which at least one of the ends of the main chain is a maleimide group, and have thus completed the present invention.

[0008] That is, the present invention includes the following. [1] A polyamide-imide resin in which at least one end of the main chain is a maleimide group. [2] The polyamide-imide resin according to [1], wherein both ends of the main chain are maleimide groups. [3] The polyamide-imide resin according to [1] or [2], which has a structure derived from a tricarboxylic acid anhydride and a structure derived from a diisocyanate. [4] The polyamide-imide resin according to any one of [1] to [3], which has a urethane bond in the main chain. [5] The polyamideimide resin according to any one of [1] to [4], wherein at least one of the terminals of the main chain is a maleimide aryloxy group. [6] The polyamide-imide resin according to any one of [1] to [5], which has a number average molecular weight (Mn) of 3,000 or less. [7] The polyamideimide resin according to any one of [1] to [6], which has a maleimide group equivalent of 100 to 1500 g / eq. [8] The polyamideimide resin according to any one of [1] to [7], which has a structural unit represented by the following formula (X-1) and a structural unit represented by the following formula (X-2): [ka] (In formula (X-1), each A independently represents a trivalent organic group. In formula (X-2), each R independently represents a divalent organic group.) [9] The polyamideimide resin according to any one of [1] to [8], which has a structural unit represented by the following formula (X-3): [ka] (In formula (X-3), each A independently represents a trivalent organic group. Each R independently represents a divalent organic group.)

[10] The polyamideimide resin according to any one of [1] to [9], represented by the following formula (X-4): [ka] (In formula (X-4), n represents an integer of 1 or more. Each A independently represents a trivalent organic group. Each R independently represents a divalent organic group. Each ring Ar independently represents an aromatic carbocyclic ring having 6 to 10 carbon atoms which may have a substituent selected from an alkyl group having 1 to 10 carbon atoms and an aryl group having 1 to 10 carbon atoms.)

[11] The polyamideimide resin according to any one of [8] to

[10] , wherein in formula (X-1), A is a trivalent organic group having 3 to 20 carbon atoms and having a 6-membered ring.

[12] The polyamideimide resin according to any one of [8] to

[11] , wherein in formula (X-2), R is an alkylene group having 1 to 20 carbon atoms which may have a substituent selected from an alkyl group having 1 to 6 carbon atoms and an aryl group having 1 to 10 carbon atoms, an arylene group having 1 to 20 carbon atoms which may have a substituent selected from an alkyl group having 1 to 6 carbon atoms and an aryl group having 1 to 10 carbon atoms, or a divalent group having 2 to 30 carbon atoms consisting of a combination thereof.

[13] The polyamide-imide resin according to any one of

[10] to

[12] , wherein in formula (X-4), the ring Ar is a benzene ring.

[14] The polyamideimide resin according to any one of

[10] to

[13] , wherein in formula (X-4), n is an integer of 1 to 20.

[15] (1) A step of reacting a tricarboxylic acid anhydride with a diisocyanate to obtain a polyamide-imide resin having an isocyanate group at the end; and (2) reacting a polyamideimide resin having an isocyanate group at its terminal with an N-(hydroxyaryl)maleimide; A method for producing a polyamideimide resin, comprising:

[16] The method for producing a polyamideimide resin according to

[15] , wherein the product polyamideimide resin is the polyamideimide resin according to any one of [1] to

[14] .

[17] A curable resin comprising the polyamideimide resin according to any one of [1] to

[14] .

[18] A resin composition containing the polyamideimide resin according to any one of [1] to

[14] .

[19] The resin composition according to

[18] , further comprising (b) a polymerization initiator.

[20] The resin composition according to

[18] or

[19] , further comprising (c1) an epoxy resin.

[21] The resin composition according to any one of

[18] to

[20] , further comprising (d1) an epoxy resin curing agent.

[22] The resin composition according to any one of

[18] to

[21] , further comprising (e) a curing accelerator.

[23] The resin composition according to any one of

[18] to

[22] , further comprising (f) a thermoplastic resin.

[24] The resin composition according to any one of

[18] to

[23] , further comprising (g) an inorganic filler.

[25] The resin composition according to any one of

[18] to

[24] , further comprising (h) an organic solvent.

[26] The resin composition according to any one of

[18] to

[25] , which is for use in an insulating layer of a circuit board.

[27] The resin composition according to any one of

[18] to

[25] , which is used for semiconductor encapsulation.

[28] A resin sheet comprising a support and a layer of the resin composition according to any one of

[18] to

[27] provided on the support.

[29] The resin sheet according to

[28] , wherein the support is a thermoplastic resin film or a metal foil.

[30] A prepreg obtained by impregnating a sheet-like fiber substrate with the resin composition according to any one of

[18] to

[27] .

[31] A cured product of the resin composition according to any one of

[18] to

[27] .

[32] A circuit board comprising an insulating layer made of a cured product of the resin composition according to any one of

[18] to

[26] .

[33] A semiconductor chip package comprising an encapsulating layer made of a cured product of the resin composition according to any one of

[18] to

[25] and

[27] .

[34] The semiconductor chip package according to

[33] , which is a fan-out type package.

[35] A semiconductor device comprising the circuit board according to

[32] .

[36] A semiconductor device comprising the semiconductor chip package according to

[33] . [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a polyamideimide resin that produces a cured product exhibiting excellent dielectric properties and heat resistance, a curable resin obtained using the polyamideimide resin, a resin composition, a resin sheet, a prepreg, a cured product, a circuit board, a semiconductor chip package, and a semiconductor device, as well as a method for producing a polyamideimide resin. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples described below, and can be implemented with any modifications within the scope of the claims and their equivalents.

[0011] In the following description, unless otherwise specified, the expressions "XX to YY" or "XX to YY" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints. When a numerical range is described in stages, the upper and lower limits of each numerical range can be combined in any way.

[0012] In the following description, "dielectric constant" refers to "relative dielectric constant" unless otherwise specified.

[0013] In the following description, unless otherwise specified, the term "optionally substituted" in reference to a compound or group means both a case where the hydrogen atoms of the compound or group are not substituted with a substituent and a case where some or all of the hydrogen atoms of the compound or group are substituted with a substituent. Furthermore, when the number of constituent atoms or carbon atoms of the compound or group is stated, the number of constituent atoms or carbon atoms does not include the number of constituent atoms or carbon atoms of substituents, unless otherwise specified.

[0014] In the following description, the term "organic group" refers to a group containing at least carbon atoms as skeletal atoms, and may be linear, branched, or cyclic. In this specification, unless otherwise specified, the number of skeletal atoms in an organic group is preferably 1 to 3,000, more preferably 1 to 1,000, even more preferably 1 to 100, still more preferably 1 to 50, and particularly preferably 1 to 30 or 1 to 20. Examples of organic groups include groups containing one or more skeletal atoms (including at least a carbon atom) selected from carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms.

[0015] In the following description, the term "aromatic ring" refers to a ring conforming to Hückel's rule, in which the number of electrons contained in the π-electron system on the ring is 4r+2 (r is a natural number), and includes monocyclic aromatic rings and fused aromatic rings in which two or more monocyclic aromatic rings are fused. Unless otherwise specified, the aromatic ring is preferably a monocyclic aromatic ring. The aromatic ring may be an aromatic carbocyclic ring having only carbon atoms as ring-constituting atoms, or an aromatic heterocyclic ring having heteroatoms such as oxygen atoms, nitrogen atoms, and sulfur atoms as ring-constituting atoms in addition to carbon atoms. Unless otherwise specified, the aromatic ring is preferably an aromatic carbocyclic ring. The number of carbon atoms in the aromatic ring is preferably 3 or more, more preferably 4 or more or 5 or more, and even more preferably 6 or more, unless otherwise specified, and the upper limit is preferably 24 or less, more preferably 18 or less or 14 or less, and even more preferably 10 or less. The number of carbon atoms does not include the number of carbon atoms of substituents.

[0016] Examples of the monocyclic aromatic ring include a benzene ring, a furan ring, a thiophene ring, a pyrrole ring, a pyrazole ring, an oxazole ring, an isoxazole ring, a furazan ring, a thiazole ring, an isothiazole ring, a thiadiazole ring, an imidazole ring, a triazole ring, a tetrazole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, and a pyridazine ring. Examples of fused aromatic rings in which two or more monocyclic aromatic rings are fused include a naphthalene ring, an anthracene ring, a phenanthrene ring, a benzofuran ring, an isobenzofuran ring, an indole ring, an isoindole ring, a benzothiophene ring, a benzimidazole ring, an indazole ring, a benzoxazole ring, a benzisoxazole ring, a benzothiazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, an acridine ring, a quinazoline ring, a cinnoline ring, a phthalazine ring, a pyridothiazole ring, a benzotriazole ring, an imidazopyridine ring, a triazopyridine ring, a purine ring, etc. Unless otherwise specified, the aromatic ring is preferably a benzene ring or a naphthalene ring, more preferably a benzene ring.

[0017] [Polyamide-imide resin] The polyamideimide resin of the present invention is a polyamideimide resin in which at least one of the main chain termini is a maleimide group. The polyamideimide resin of the present invention in which at least one of the main chain termini is a maleimide group can produce a cured product exhibiting dramatically superior dielectric properties and heat resistance compared to conventional maleimide resins. This is believed to be due to the polyamideimide skeleton. The present inventors have also confirmed that the polyamideimide resin of the present invention in which at least one of the main chain termini is a maleimide group has higher solubility in solvents and compatibility with other resins compared to conventional maleimide resins. This is presumably due to the asymmetric polyamideimide structure. The present inventors have also confirmed that the polyamideimide resin of the present invention can produce a cured product that is excellent in smear removal during via hole formation and can suppress the haloing phenomenon. Here, the haloing phenomenon refers to the phenomenon in which the insulating layer resin around the via hole deteriorates during via hole formation. The deteriorated portion where the haloing phenomenon occurs is easily corroded by chemicals such as roughening solutions, causing delamination between the insulating layer and the inner layer substrate, which in turn results in a deterioration in electrical conductivity reliability.

[0018] In the polyamide-imide resin of the present invention, both ends of the main chain are preferably maleimide groups, from the viewpoint of further reducing the dielectric constant and dielectric loss tangent of the cured product.

[0019] In one embodiment, the polyamide-imide resin can be obtained by reacting a tricarboxylic acid anhydride with a diisocyanate. That is, the polyamide-imide resin of the present invention preferably has a structure derived from a tricarboxylic acid anhydride and a structure derived from a diisocyanate.

[0020] The polyamide-imide resin of the present invention preferably has a urethane bond in the main chain. As described above, when a polyamide-imide resin is obtained by reacting a tricarboxylic acid anhydride with a diisocyanate, the terminal may be an isocyanate group (-NCO). When the isocyanate group reacts with a compound having a hydroxy group, a urethane bond may be formed.

[0021] In one embodiment, the polyamideimide resin of the present invention preferably has a maleimide aryloxy group at least one end of the main chain. The maleimide aryloxy group is a monovalent group represented by the following formula (Y-1). Furthermore, the polyamideimide resin of the present invention more preferably has a maleimide aryloxy group at both ends of the main chain. [ka] (In the formula, the ring Ar represents an aromatic ring which may have a substituent, and * represents a bond.)

[0022] As described above, when a polyamide-imide resin is obtained by reacting a tricarboxylic acid anhydride with a diisocyanate, the terminals may be isocyanate groups (-NCO). Reaction of the isocyanate groups with an N-(hydroxyaryl)maleimide can produce urethane bonds. The present inventors have discovered that the heat resistance of the cured product is further improved when at least one of the terminals of the main chain of the polyamide-imide resin is a maleimide aryloxy group. This is presumably because, while typical urethane bonds formed from an isocyanate group and a phenol are prone to thermal decomposition, the electronic state of the urethane bond is changed by the phenol having a maleimide group as a substituent, improving stability.

[0023] Furthermore, since at least one or both of the ends of the main chain of the polyamideimide resin of the present invention are maleimidearyloxy groups, the increase in molecular weight of the polyamideimide resin of the present invention can be suppressed, and the solubility in solvents and compatibility with other resins can be further improved.

[0024] When the polyamide-imide resin of the present invention has a structure derived from a tricarboxylic acid anhydride having an asymmetric structure represented by the following formula (XA-1) and a structure derived from a diisocyanate having an asymmetric structure represented by the following formula (XB-1), the structural units of the polyamide-imide resin of the present invention may be four types of positional isomers represented by the following formulae (XAB-1) to (XAB-4). [ka] (wherein the trivalent group X A The numbers 1 to 3 attached to the bond represent the trivalent group X A is asymmetric, meaning that three bonds can be distinguished.)

[0025] In the following description, the polyamideimide resin of the present invention may be described using structural formulas. Unless otherwise specified, the expression of any one of formulas (XAB-1) to (XAB-4) is considered to encompass all structures of formulas (XAB-1) to (XAB-4). That is, a "polyamideimide resin having a structural unit represented by formula (XAB-1)" means a "polyamideimide resin having one or more structural units selected from formulas (XAB-1) to (XAB-4)." In the case of a polyamideimide resin having two or more structural units selected from formulas (XAB-1) to (XAB-4), this also includes polyamideimide resins in which the two or more structural units are bonded in any manner. Examples of bonding modes include random copolymerization, alternating copolymerization, block copolymerization, graft copolymerization, and ordered copolymerization.

[0026] Furthermore, even when the repeat number nx of the structural unit is explicitly stated, as in the following formula (XAB-5), "a polyamideimide resin represented by formula (XAB-5)" means "a polyamideimide resin having one or more structural units selected from formulas (XAB-1) to (XAB-4)." In the case of a polyamideimide resin having two or more structural units selected from formulas (XAB-1) to (XAB-4), this also includes polyamideimide resins in which the two or more structural units are bonded in any manner. Examples of bonding modes include random copolymerization, alternating copolymerization, block copolymerization, graft copolymerization, and ordered copolymerization. Furthermore, the repeat number nx refers to the sum of the repeat number of the structural unit represented by formula (XAB-1), the repeat number of the structural unit represented by formula (XAB-2), the repeat number of the structural unit represented by formula (XAB-3), and the repeat number of the structural unit represented by formula (XAB-4). [ka]

[0027] Similarly, as in the above formula (XAB-6), the number of repeating structural units nx, the terminal group X E1 and terminal group X E2 Even when the formula (XAB-6) is explicitly stated, "a polyamide-imide resin represented by formula (XAB-6)" means "a polyamide-imide resin having one or more structural units selected from formulas (XAB-1) to (XAB-4), each of which has X at its terminal. E1 and X E2 The term "polyamideimide resin having two or more structural units selected from formulae (XAB-1) to (XAB-4)" refers to a polyamideimide resin in which the two or more structural units are bonded in any manner. Examples of the bonding manner include random copolymerization, alternating copolymerization, block copolymerization, graft copolymerization, and ordered copolymerization. The repeat number nx refers to the sum of the repeat number of the structural unit represented by formula (XAB-1), the repeat number of the structural unit represented by formula (XAB-2), the repeat number of the structural unit represented by formula (XAB-3), and the repeat number of the structural unit represented by formula (XAB-4). In other words, the polyamideimide resin represented by formula (XAB-6) has a maximum of 4 nx The term "polyamide-imide resin represented by formula (XAB-6)" encompasses the positional isomers.

[0028] In one embodiment, the polyamideimide resin of the present invention preferably has a structural unit represented by the following formula (X-1) and a structural unit represented by the following formula (X-2). [ka] (In formula (X-1), each A independently represents a trivalent organic group. In formula (X-2), each R independently represents a divalent organic group.)

[0029] In formula (X-1), each A independently represents a trivalent organic group. A is preferably a trivalent organic group having 3 to 40 carbon atoms. The lower limit of the number of carbon atoms of A is more preferably 4 or more, and even more preferably 5 or more. The upper limit of the number of carbon atoms of the trivalent organic group is more preferably 36 or less, 32 or less, or 28 or less, even more preferably 24 or less, 20 or less, 16 or less, or 12 or less, and particularly preferably 10 or less, 9 or less, 8 or less, or 7 or less. In one embodiment, A is preferably a trivalent organic group having 3 to 20 carbon atoms.

[0030] A is preferably a trivalent organic group having constituent atoms selected from carbon, oxygen, hydrogen, nitrogen, sulfur, and fluorine atoms, more preferably a trivalent organic group having constituent atoms selected from carbon, oxygen, and hydrogen atoms, and even more preferably a trivalent organic group having constituent atoms of carbon and hydrogen atoms.

[0031] In one embodiment, A preferably has a ring structure. The number of skeletal atoms constituting the ring is preferably 3 to 20. The lower limit of the number of constituent atoms constituting the ring is more preferably 4 or more, and even more preferably 5 or more. The upper limit of the number of constituent atoms constituting the ring is preferably 20 or less, 16 or less, or 12 or less, more preferably 10 or less or 9 or less, and even more preferably 8 or less or 7 or less. In one embodiment, A is preferably a trivalent organic group having a 6-membered ring.

[0032] The ring structure in A includes an aromatic ring and an alicyclic structure.

[0033] The aromatic ring includes a monocyclic aromatic ring and a fused aromatic ring in which two or more monocyclic aromatic rings are fused, and the monocyclic aromatic ring is preferred.The aromatic ring also includes an aromatic carbocycle having only carbon atoms as ring-constituting atoms, and an aromatic heterocycle having heteroatoms such as oxygen atoms, nitrogen atoms, and sulfur atoms as ring-constituting atoms in addition to carbon atoms, and the aromatic carbocycle is preferred.Among these, the aromatic ring is preferably a benzene ring or a naphthalene ring, and more preferably a benzene ring.

[0034] The alicyclic structure includes a monocyclic structure and a fused ring structure in which two or more monocyclic structures are fused, with a monocyclic structure being preferred.The alicyclic structure also includes an alicyclic hydrocarbon structure having only carbon atoms as ring-constituting atoms, and an alicyclic heterocyclic structure having heteroatoms such as oxygen atoms, nitrogen atoms, and sulfur atoms as ring-constituting atoms in addition to carbon atoms, with a alicyclic hydrocarbon structure being preferred.The alicyclic hydrocarbon structure includes a cyclopentane structure, a cyclohexane structure, a cycloheptane structure, a decahydronaphthalene structure, and the like, with a cyclohexane structure being preferred.

[0035] Specific examples of A include the following groups (i) to (xxii): In the formula, * represents a bond. A is preferably group (i) or group (xiii). [ka]

[0036] The trivalent organic group may have a substituent. Examples of the substituent include linear, branched, or cyclic alkyl groups having 1 to 10 carbon atoms, such as methyl, ethyl, n-propyl, 2-propyl, n-butyl, s-butyl, i-butyl, t-butyl, cyclopentyl, and cyclohexyl; halogen atoms such as fluorine, chlorine, bromine, and iodine; alkoxy groups having 1 to 10 carbon atoms, such as methoxy, ethoxy, propoxy, t-butoxy, and phenoxy; hydroxy groups; halogen-substituted alkyl groups such as trifluoromethyl; cycloalkyloxy groups; aryl groups; arylalkyl groups; monovalent heterocyclic groups; alkylidene groups; amino groups; silyl groups; acyl groups; acyloxy groups; carboxy groups; sulfo groups; cyano groups; nitro groups; mercapto groups; and oxo groups, with alkyl groups being preferred. The above-mentioned substituents may further have a substituent (hereinafter sometimes referred to as a "secondary substituent"). The substituent may be contained alone or in combination of two or more kinds.

[0037] In formula (X-2), each R independently represents a divalent organic group. R is preferably a divalent organic group having constituent atoms selected from carbon, oxygen, hydrogen, nitrogen, fluorine, chlorine, and sulfur atoms, more preferably a divalent organic group having constituent atoms selected from carbon, oxygen, and hydrogen atoms, and even more preferably a divalent organic group having constituent atoms of carbon and hydrogen atoms.

[0038] The number of constituent atoms of R is preferably 1 to 50. The lower limit of the number of constituent atoms of R is preferably 2 or more or 3 or more, more preferably 5 or more, even more preferably 8 or more, and particularly preferably 10 or more. The upper limit of the number of constituent atoms of R is preferably 45 or less, more preferably 40 or less, even more preferably 35 or less, and particularly preferably 30 or less.

[0039] The number of carbon atoms in R is preferably 1 to 30. The lower limit of the number of carbon atoms in R is preferably 2 or more, more preferably 3 or more, 4 or more, or 5 or more, and even more preferably 6 or more. The upper limit is preferably 28 or less, more preferably 25 or less, even more preferably 20 or less, and particularly preferably 15 or less or 12 or less.

[0040] R is preferably a divalent aliphatic hydrocarbon group which may have a substituent, a divalent aromatic group which may have a substituent, or a divalent group consisting of a combination thereof. "Combinations of these" may be a combination of two or more. Furthermore, "combinations of these" include combinations of two or more "divalent aliphatic hydrocarbon groups which may have a substituent," combinations of two or more "divalent aromatic groups which may have a substituent," and combinations of two or more including both "divalent aliphatic hydrocarbon groups which may have a substituent" and "divalent aromatic groups which may have a substituent."

[0041] The "divalent aliphatic hydrocarbon group" in R refers to a "group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon compound." The divalent aliphatic hydrocarbon group may be linear or branched, and may also be a divalent alicyclic hydrocarbon group containing a ring structure. Examples of divalent aliphatic hydrocarbon groups include divalent unsaturated aliphatic hydrocarbon groups having an unsaturated bond and divalent saturated aliphatic hydrocarbon groups having no unsaturated bond, with a divalent saturated aliphatic hydrocarbon group being preferred. The "divalent alicyclic hydrocarbon group" refers to a "group obtained by removing two hydrogen atoms from an alicyclic hydrocarbon compound." The "divalent unsaturated aliphatic hydrocarbon group" refers to a "group obtained by removing two hydrogen atoms from an unsaturated aliphatic hydrocarbon compound." The "divalent saturated aliphatic hydrocarbon group" refers to a "group obtained by removing two hydrogen atoms from a saturated aliphatic hydrocarbon compound."

[0042] Examples of the divalent aliphatic hydrocarbon group for R include an alkylene group and an alkenylene group, with an alkylene group being preferred.

[0043] The alkylene group in R is a chain (straight-chain or branched) alkylene group or a cyclic alkylene group. The alkylene group preferably has 1 to 20 carbon atoms. The lower limit of the number of carbon atoms of the alkylene group is more preferably 2 or more or 3 or more, even more preferably 4 or more, and particularly preferably 5 or more. The upper limit of the number of carbon atoms of the alkylene group is more preferably 18 or less or 16 or less, even more preferably 14 or less or 12 or less. The number of carbon atoms does not include the number of carbon atoms of substituents. Examples of chain alkylene groups include a methylene group, an ethylene group, a propylene group, a butylene group, an isobutylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, and a decylene group. A pentylene group or a hexylene group is preferred, and a hexylene group is more preferred. Examples of the cyclic alkylene group include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a decahydronaphthalene group, a norbornanylene group, a dicyclopentanylene group, and an adamantanylene group, with a cyclohexylene group being preferred.

[0044] The alkenylene group in R is a chain (straight-chain or branched) alkenylene group or a cyclic alkenylene group. The alkenylene group preferably has 2 to 20 carbon atoms. The lower limit of the number of carbon atoms of the alkenylene group is more preferably 3 or more, even more preferably 4 or more, and particularly preferably 5 or more. The upper limit of the number of carbon atoms of the alkenylene group is more preferably 18 or less or 16 or less, even more preferably 14 or less or 12 or less. The number of carbon atoms does not include the number of carbon atoms of substituents. Examples of alkenylene groups include ethenylene, propenylene, butenylene, pentenylene, and hexenylene groups. Examples of cyclic alkenylene groups include cyclopropenylene, cyclobutenylene, cyclopentenylene, cyclohexenylene, and norbornenylene groups.

[0045] The divalent aromatic group for R is a group obtained by removing two hydrogen atoms on an aromatic ring from an aromatic compound, and is also called an "arylene group." The number of carbon atoms in the arylene group is preferably 1 to 20. The lower limit of the number of carbon atoms in the arylene group is preferably 3 or more or 4 or more, more preferably 5 or more, and even more preferably 6 or more. The upper limit of the number of carbon atoms in the arylene group is more preferably 16 or less or 12 or less, and even more preferably 10 or less. Examples of the arylene group include a phenylene group, a naphthylene group, a biphenylene group (—C6H4—C6H4—), a thienylene group, a pyrrolylene group, a furanylene group, a furylene group, a pyridylene group, a pyridazinylene group, a pyrimidylene group, a pyrazinylene group, a triazinylene group, a pyrrolylene group, a piperidylene group, a quinolylene group, and an isoquinolylene group. A phenylene group, a naphthylene group, or a biphenylene group is preferred, a phenylene group or a naphthylene group is more preferred, and a phenylene group is even more preferred.

[0046] The lower limit of the number of carbon atoms in the divalent group in R consisting of a combination of a divalent aliphatic hydrocarbon group which may have a substituent and a divalent aromatic group which may have a substituent is 2 or more, preferably 3 or more, 4 or more, or 5 or more, more preferably 6 or more, and particularly preferably 7 or more. The upper limit is preferably 30 or less, more preferably 25 or less, even more preferably 20 or less, and particularly preferably 15 or less or 12 or less. Examples of divalent groups consisting of a combination of a divalent aliphatic hydrocarbon group which may have a substituent and a divalent aromatic group which may have a substituent include those shown below. [ka] (In the formula, * represents a bond.)

[0047] When the divalent organic group in R can have two bonds at multiple positions, the bonds may be at any position. Furthermore, a structure in which the bonds are formed by removing hydrogen atoms in the substituent in R may also be used. For example, when R is a hexylene group, it may be any of a 1,2-hexylene group, a 1,3-hexylene group, a 1,4-hexylene group, a 1,5-hexylene group, and a 1,6-hexylene group (hexamethylene group), with a 1,6-hexylene group (hexamethylene group) being preferred. For example, when R is a phenylene group, examples include a 1,2-phenylene group, a 1,3-phenylene group, and a 1,4-phenylene group, with a 1,3-phenylene group being preferred.

[0048] Examples of the substituent that the divalent aliphatic hydrocarbon group and divalent aromatic group for R have include an alkyl group, a halogen atom, an alkoxy group, a hydroxy group, a halogen atom-substituted alkyl group, an alkyloxy group, an aryl group, an arylalkyl group, a monovalent heterocyclic group, an alkylidene group, an amino group, a silyl group, an acyl group, an acyloxy group, a carboxy group, a sulfo group, a cyano group, a nitro group, a mercapto group, and an oxo group, and an alkyl group or an aryl group is preferred.

[0049] The alkyl group as a substituent in R is a chain (straight-chain or branched) alkyl group or a cyclic alkyl group. The number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 1 to 6, even more preferably 1 to 5 or 1 to 3, and particularly preferably 1. Examples of the chain alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, an n-pentyl group, an isopentyl group, a hexyl group, a 2-ethylhexyl group, an octyl group, and a decyl group. Preferred are a methyl group, an ethyl group, an n-propyl group, or an isopropyl group, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. Examples of the cyclic alkyl group include a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.

[0050] The number of carbon atoms in the aryl group as a substituent in R is preferably 1 to 10, more preferably 3 to 10, further preferably 5 to 10, and particularly preferably 6 to 10. Examples of the aryl group include a phenyl group, a naphthyl group, a thienyl group, a pyrrolyl group, a furanyl group, a furyl group, a pyridyl group, a pyridazinyl group, a pyrimidyl group, a pyrazinyl group, a triazinyl group, a pyrrolidyl group, a piperidyl group, a quinolyl group, and an isoquinolyl group, among which a phenyl group or a naphthyl group is preferred, and a phenyl group is more preferred.

[0051] Among these, R is preferably an alkylene group having 1 to 20 carbon atoms which may have a substituent selected from an alkyl group having 1 to 6 carbon atoms and an aryl group having 1 to 10 carbon atoms, an arylene group having 1 to 20 carbon atoms which may have a substituent selected from an alkyl group having 1 to 6 carbon atoms and an aryl group having 1 to 10 carbon atoms, or a divalent group having 2 to 30 carbon atoms which is a combination thereof. Examples of R which satisfy this requirement include divalent groups represented by the following formula: [ka] (In the formula, * represents a bond.)

[0052] In one embodiment, the polyamideimide resin of the present invention preferably has a structural unit represented by the following formula (X-3). [ka] (In formula (X-3), each A independently represents a trivalent organic group. Each R independently represents a divalent organic group.)

[0053] In formula (X-3), each A independently represents a trivalent organic group and is the same as A in formula (X-1).

[0054] In formula (X-3), each R independently represents a divalent organic group and is the same as R in formula (X-2).

[0055] In one embodiment, the polyamide-imide resin of the present invention is preferably a polyamide-imide resin represented by the following formula (X-4). [ka] (In formula (X-4), n represents an integer of 1 or more. Each A independently represents a trivalent organic group. Each R independently represents a divalent organic group. Each ring Ar independently represents an aromatic carbocyclic ring having 6 to 10 carbon atoms which may have a substituent selected from an alkyl group having 1 to 10 carbon atoms and an aryl group having 1 to 10 carbon atoms.)

[0056] In formula (X-4), n represents an integer of 1 or greater. From the viewpoint of further improving solubility in solvents and compatibility with other resins, the upper limit of n is preferably 100 or less or 50 or less, more preferably 40 or less, 30 or less, or 20 or less, even more preferably 18 or less, 16 or less, 14 or less, or 12 or less, and particularly preferably 10 or less, 8 or less, or 7 or less. The lower limit of n may be 2 or more, 3 or more, 4 or more, etc. In one embodiment, n may be 1. Furthermore, the polyamideimide resin of the present invention may be an oligomer.

[0057] When the polyamideimide resin of the present invention is a mixture of compounds represented by formula (X-4) having different values ​​of n, the average value of n is preferably 0.1 to 100. From the viewpoint of further improving solubility in solvents and compatibility with other resins, the upper limit of the average value of n is preferably 100 or 50, more preferably 40 or 30 or 20, even more preferably 18 or 16 or 14 or 12, and particularly preferably 10 or 8 or 7. The lower limit of the average value of n can be 0.2 or more, 0.5 or more, 0.8 or more, 1 or more, 1.1 or more, 1.2 or more, 1.5 or more, 2 or more, 3 or more, 4 or more, etc.

[0058] In formula (X-4), each A independently represents a trivalent organic group and is the same as A in formula (X-1). The n As in formula (X-4) may be the same or different, and are preferably the same.

[0059] In formula (X-4), each R independently represents a divalent organic group and is the same as R in formula (X-2). The n+1 Rs in formula (X-4) may be the same or different from one another, and it is preferable that at least two of the n+1 Rs are the same, and it is more preferable that all of the n+1 Rs are the same.

[0060] In formula (X-4), each ring Ar independently represents an aromatic carbocyclic ring having 6 to 10 carbon atoms, which may have a substituent selected from an alkyl group having 1 to 10 carbon atoms and an aryl group having 1 to 10 carbon atoms. Examples of the aromatic carbocyclic ring having 6 to 10 carbon atoms include a benzene ring and a naphthalene ring, with a benzene ring being preferred. The two rings Ar in formula (X-4) may be the same or different, and are preferably the same.

[0061] The alkyl group as a substituent in the ring Ar is a chain (straight-chain or branched) alkyl group or a cyclic alkyl group. The alkyl group has 1 to 10 carbon atoms, preferably 1 to 6, more preferably 1 to 5, still more preferably 1 to 3, and particularly preferably 1. Examples of the chain alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, an n-pentyl group, an isopentyl group, a hexyl group, a 2-ethylhexyl group, an octyl group, and a decyl group. Preferred are a methyl group, an ethyl group, an n-propyl group, or an isopropyl group, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. Examples of the cyclic alkyl group include a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.

[0062] An aryl group is a group in which one hydrogen atom on an aromatic ring has been removed from an aromatic compound. The number of carbon atoms in the aryl group as a substituent in the ring Ar is 1 to 10, preferably 3 to 10, more preferably 5 to 10, and even more preferably 6 to 10. Examples of the aryl group include a phenyl group, a naphthyl group, a thienyl group, a pyrrolyl group, a furanyl group, a furyl group, a pyridyl group, a pyridazinyl group, a pyrimidyl group, a pyrazinyl group, a triazinyl group, a pyrrolidyl group, a piperidyl group, a quinolyl group, and an isoquinolyl group. A phenyl group or a naphthyl group is preferred, and a phenyl group is more preferred.

[0063] In one embodiment, it is preferred that ring Ar has no substituents other than the urethane bond and maleimide group specified in formula (X-4).

[0064] In one embodiment, the ring Ar is preferably a benzene ring. When the ring Ar is a benzene ring, the relationship between the oxygen atom of the urethane bond and the substitution position of the maleimide group in formula (X-4) may be any of the ortho position, meta position, and para position, and the para position is preferred.

[0065] Specific examples of the compound represented by formula (X-4) include compounds represented by the following formulas. [ka]

[0066] The maleimide group equivalent of the polyamideimide resin of the present invention in which at least one of the main chain terminals is a maleimide group is preferably 30 to 5000 g / eq. The lower limit of the maleimide group equivalent is more preferably 75 g / eq or more or 100 g / eq or more, even more preferably 200 g / eq or more, and particularly preferably 300 g / eq or more or 400 g / eq or more. The upper limit of the maleimide group equivalent is more preferably 4000 g / eq or less, 3000 g / eq or less, or 2500 g / eq or less, even more preferably 2000 g / eq or less or 1500 g / eq or less, and particularly preferably 1000 g / eq or less or 800 g / eq or less.

[0067] The number average molecular weight (Mn) of the polyamideimide resin of the present invention is preferably 5000 or less, more preferably 4500 or less or 4000 or less, even more preferably 3500 or less or 3000 or less, and particularly preferably 2500 or less or 2000 or less. The lower limit is preferably 100 or more or 200 or more, more preferably 300 or more or 400 or more, even more preferably 500 or more or 600 or more, and particularly preferably 700 or more or 800 or more.

[0068] The weight average molecular weight (Mw) of the polyamideimide resin of the present invention is preferably 10,000 or less, more preferably 9,000 or less or 8,000 or less, even more preferably 7,000 or less or 6,000 or less, and particularly preferably 5,000 or less or 4,000 or less. The lower limit is preferably 200 or more or 400 or more, more preferably 600 or more or 800 or more, even more preferably 1,000 or more or 1,200 or more, and particularly preferably 1,400 or more or 1,600 or more.

[0069] When the number average molecular weight of the polyamideimide resin of the present invention is Mn and the weight average molecular weight is Mw, the ratio of Mw to Mn (Mw / Mn) is preferably greater than 1. The lower limit of Mw / Mn is more preferably 1.1 or 1.2 or more, even more preferably 1.3 or 1.4 or more, and particularly preferably 1.5 or more. The upper limit of Mw / Mn is preferably 10 or 5 or less, more preferably 4.5 or 4.3 or less, even more preferably 4.0 or less, 3.9 or 3.8 or less, and particularly preferably 3.7 or 3.6 or less. Mw, Mn, and Mw / Mn can be calculated by gel permeation chromatography (GPC).

[0070] [Method of manufacturing polyamide-imide resin] The method for producing a polyamide-imide resin of the present invention comprises the steps of: (1) a step of reacting a tricarboxylic acid anhydride with a diisocyanate to obtain a polyamide-imide resin having an isocyanate group at the end; and (2) reacting a polyamideimide resin having an isocyanate group at its terminal with an N-(hydroxyaryl)maleimide; Includes.

[0071] <Structure of raw materials> The tricarboxylic acid anhydride is preferably a compound represented by the following formula (Y-2). [ka] (In formula (Y-2), A represents a trivalent organic group.)

[0072] In formula (Y-2), A represents a trivalent organic group and is the same as A in formula (X-1).

[0073] Specific examples of tricarboxylic acid anhydrides include trimellitic anhydride, cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride, 1,2,3-propanetricarboxylic acid-1,2-anhydride, 1,2,5-naphthalenetricarboxylic acid-1,2-anhydride, and 1,4,5-naphthalenetricarboxylic acid-4,5-anhydride, and trimellitic anhydride or cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride is preferred.

[0074] The diisocyanate is preferably a compound represented by the following formula (Y-3). [ka] (In formula (Y-3), R represents a divalent organic group.)

[0075] In formula (Y-3), R represents a divalent organic group and is the same as R in formula (X-2).

[0076] Specific examples of diisocyanates include isophorone diisocyanate, tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-pentane diisocyanate, 1,6-hexane diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 1,4-cyclohexane diisocyanate, dicyclohexylmethane 4,4'-diisocyanate, m-xylene diisocyanate, and p-xylene. Examples of the diisocyanate include diisocyanate, 1,5-naphthylene diisocyanate, 3,3'-bitrylene-4,4'-diisocyanate, paraphenylene diisocyanate, and 1,3-bis(isocyanatomethyl)cyclohexane. Preferred are isophorone diisocyanate, tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,6-hexane diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate.

[0077] As the N-(hydroxyaryl)maleimide, a compound represented by the following formula (Y-4) is preferred. [ka] (In formula (Y-4), the ring Ar represents an aromatic carbocyclic ring having 6 to 10 carbon atoms which may have a substituent selected from an alkyl group having 1 to 10 carbon atoms and an aryl group having 1 to 10 carbon atoms.)

[0078] In formula (Y-4), ring Ar represents an aromatic carbocyclic ring having 6 to 10 carbon atoms which may have a substituent selected from an alkyl group having 1 to 10 carbon atoms and an aryl group having 1 to 10 carbon atoms, and is the same as ring Ar in formula (X-4).

[0079] In one embodiment, the ring Ar in formula (Y-4) is preferably a benzene ring. When the ring Ar is a benzene ring, the substitution positions of the hydroxy group and the maleimide group in formula (Y-4) may be any of the ortho position, meta position, and para position, and the para position is preferred.

[0080] Specific examples of N-(hydroxyaryl)maleimides include N-(4-hydroxyphenyl)maleimide, N-(3-hydroxyphenyl)maleimide, N-(2-hydroxyphenyl)maleimide, and N-(4-hydroxynaphthyl)maleimide, with N-(4-hydroxyphenyl)maleimide being preferred.

[0081] <Process (1)> In step (1), a tricarboxylic acid anhydride is reacted with a diisocyanate to obtain a polyamide-imide resin having an isocyanate terminal group. Adjusting the ratio of the tricarboxylic acid anhydride to the diisocyanate allows for adjustment of the value of n in formula (X-4) above, as well as the number-average molecular weight and weight-average molecular weight of the polyamide-imide resin. Furthermore, when the ratio of the number of moles of diisocyanate charged to the number of moles of tricarboxylic acid anhydride charged (diisocyanate / tricarboxylic acid anhydride) is greater than 1, a polyamide-imide resin having an isocyanate terminal group can be easily produced. The lower limit of the ratio of the number of moles of diisocyanate charged to the number of moles of tricarboxylic acid anhydride charged (diisocyanate / tricarboxylic acid anhydride) is preferably 1 or more or more, more preferably 1.01 or more, even more preferably 1.05 or more or 1.1 or more, and particularly preferably 1.15 or more or 1.2 or more. The upper limit is preferably 2.5 or less, more preferably 2.1 or less, even more preferably 2 or less, and particularly preferably 1.8 or less.

[0082] The reaction in step (1) proceeds without a catalyst, but it is preferable to use a catalyst. A base catalyst is preferred, with an amine catalyst being more preferred. Examples of amine catalysts include amidine catalysts, imidazole catalysts, pyridine catalysts, and trialkylamine catalysts. Amidine catalysts or trialkylamine catalysts are preferred, with trialkylamine catalysts being more preferred. Examples of amidine catalysts include 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 1,5-diazabicyclo[4.3.0]-5-nonene (DBN), with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) being preferred. Examples of imidazole catalysts include N-methylimidazole (NMZ), 2-ethyl-4-methylimidazole (2E4MZ), and the like. Examples of pyridine catalysts include pyridine, N,N-dimethylaminopyridine (DMAP), and 2,6-lutidine. Examples of trialkylamine catalysts include 1,4-diazabicyclo[2.2.2]octane (DABCO), 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30), triethylamine, tributylamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'',N''-pentamethyldiethylenetriamine, N-ethylmorpholine, and bis(2-morpholinoethyl)ether, with 1,4-diazabicyclo[2.2.2]octane (DABCO) being preferred. The catalysts may be used alone or in combination of two or more.

[0083] The reaction in step (1) may be carried out in a solvent-free system without using a solvent, or in an organic solvent system using an organic solvent. Examples of organic solvents used in the reaction include ketone solvents such as acetone, ethyl methyl ketone (MEK), methyl isobutyl ketone, and cyclohexanone; acetate ester solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and diethylene glycol monoethyl ether acetate (carbitol acetate); carbitol solvents such as cellosolve and butyl carbitol; aromatic hydrocarbon solvents such as toluene and xylene; and amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. The organic solvents may be used alone or in combination of two or more.

[0084] The reaction temperature in step (1) is not particularly limited as long as the reaction proceeds, and may be, for example, in the range of 0 to 180° C. The reaction time is also not particularly limited as long as the reaction proceeds sufficiently, and may be, for example, in the range of 30 minutes to 20 hours.

[0085] After the reaction in step (1), the polyamideimide resin having an isocyanate group at the end may be purified, or may be used in the step (2) described below without purification.

[0086] <Process (2)> In step (2), the polyamideimide resin having an isocyanate group at its terminal, produced in step (1), is reacted with N-(hydroxyaryl)maleimide. In step (2), the isocyanate group at the terminal of the polyamideimide resin produced in step (1) reacts with the hydroxy group of the N-(hydroxyaryl)maleimide, presumably to produce a urethane bond.

[0087] In step (2), it is preferable to use a catalyst. Examples of the catalyst include base catalysts and metal catalysts, with base catalysts being preferred. Examples of the base catalyst include amine catalysts. Examples of the amine catalyst include amidine catalysts, imidazole catalysts, pyridine catalysts, and trialkylamine catalysts, with amidine catalysts and trialkylamine catalysts being preferred, and trialkylamine catalysts being more preferred. Examples of the amidine catalyst include 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 1,5-diazabicyclo[4.3.0]-5-nonene (DBN), with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) being preferred. Examples of the imidazole catalyst include N-methylimidazole (NMZ), 2-ethyl-4-methylimidazole (2E4MZ), and the like. Examples of pyridine catalysts include pyridine, N,N-dimethylaminopyridine (DMAP), and 2,6-lutidine. Examples of trialkylamine catalysts include 1,4-diazabicyclo[2.2.2]octane (DABCO), 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30), triethylamine, tributylamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'',N''-pentamethyldiethylenetriamine, N-ethylmorpholine, and bis(2-morpholinoethyl)ether, with 1,4-diazabicyclo[2.2.2]octane (DABCO) being preferred. Examples of metal catalysts include potassium salt catalysts and tin catalysts. Examples of potassium salt catalysts include potassium acetate and potassium octoate. Examples of tin catalysts include dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dichloride, dibutyltin diacetylacetonate, dimethyltin dilaurate, dioctyltin diacetate, dioctyltin dilaurate, dioctyltin diacetylacetonate, etc. When a base catalyst is used in step (1) and the polyamideimide resin having isocyanate groups at its terminals is used in step (2) without purification, the base catalyst used in step (1) may remain in the reaction solution, and the remaining base catalyst may be used as the catalyst in step (2).

[0088] The reaction in step (2) may be carried out in a solvent-free system without using a solvent, or in an organic solvent system using an organic solvent. Examples of organic solvents used in the reaction include ketone solvents such as acetone, ethyl methyl ketone (MEK), methyl isobutyl ketone, and cyclohexanone; acetate ester solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and diethylene glycol monoethyl ether acetate (carbitol acetate); carbitol solvents such as cellosolve and butyl carbitol; aromatic hydrocarbon solvents such as toluene and xylene; and amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. The organic solvents may be used alone or in combination of two or more.

[0089] The reaction temperature is not particularly limited as long as the reaction proceeds, and may be, for example, in the range of 0 to 100° C., preferably 10 to 80° C., and more preferably 20 to 70° C. The reaction time is also not particularly limited as long as the reaction proceeds sufficiently, and may be, for example, in the range of 30 minutes to 96 hours, preferably 1 to 72 hours, more preferably 8 to 64 hours, and even more preferably 16 to 56 hours.

[0090] After the reaction in step (2), the resulting polyamide-imide resin may be purified. For example, after the reaction, a purification step such as water washing or microfiltration may be performed to remove by-product salts and excess starting materials from the system. Specifically, after the reaction, an amount of water necessary to dissolve the by-product salts is added, and the mixture is allowed to stand and separated, and the aqueous layer is discarded. If necessary, an acid is further added for neutralization, and water washing is repeated. Thereafter, impurities are removed and purified through a dehydration step using a chemical or azeotropic method, microfiltration, or the like, and the organic solvent is then removed by distillation, if necessary, to obtain a polyamide-imide resin. The organic solvent may also be used as it is as the organic solvent for the resin composition without being completely removed.

[0091] [Curable resin] The polyamideimide resin of the present invention can provide a cured product exhibiting excellent dielectric properties and heat resistance, and can achieve the low transmission loss and heat resistance required for 5G applications. The inventors have also confirmed that the polyamideimide resin of the present invention can provide a cured product that is excellent in smear removal during via hole formation and can suppress the halo phenomenon. In a preferred embodiment, the maleimide resin of the present invention can be suitably used as a curable resin. That is, in a preferred embodiment, the curable resin of the present invention comprises a polyamideimide resin in which at least one end of the main chain is a maleimide group.

[0092] [Resin composition] The polyamideimide resin of the present invention can be used to produce a resin composition, and the present invention also provides such a resin composition.

[0093] The resin composition of the present invention contains the polyamideimide resin of the present invention, i.e., a polyamideimide resin in which at least one of the main chain termini is a maleimide group. Hereinafter, the polyamideimide resin in which at least one of the main chain termini is a maleimide group contained in the resin composition will also be referred to as "component (a)" and may be expressed as "(a) polyamideimide resin in which at least one of the main chain termini is a maleimide group." Preferred embodiments of the polyamideimide resin in which at least one of the main chain termini is a maleimide group contained in the resin composition are as explained above in the section [Polyamideimide Resin].

[0094] The resin composition of the present invention may further contain, as an optional component, a curable resin other than a polyamideimide resin in which at least one end of the main chain is a maleimide group (hereinafter simply referred to as "(c) other curable resin"). The resin composition of the present invention may also contain further optional components. Examples of optional components include (b) a polymerization initiator, (d) a curing agent, (e) a curing accelerator, (f) a thermoplastic resin, (g) an inorganic filler, (h) an organic solvent, and (i) other additives. Each component contained in the resin composition will be described in detail below.

[0095] <(a) Polyamide-imide resin in which at least one of the ends of the main chain is a maleimide group> The resin composition of the present invention contains (a) a polyamideimide resin in which at least one terminal of the main chain is a maleimide group. The (a) component may be used alone or in combination of two or more. To produce a cured product exhibiting excellent dielectric properties and heat resistance, the content of the (a) component in the resin composition is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, 20% by mass or more, 22% by mass or more, or 23% by mass or more, based on 100% by mass of the resin components in the resin composition. The upper limit of the content is not particularly limited and may be determined depending on the properties required of the resin composition. For example, the upper limit may be 100% by mass, or 99.5% by mass or less, 99% by mass or less, 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, 50% by mass or less, 40% by mass or less, or 30% by mass or less. In the present invention, the term "resin component" in relation to the resin composition refers to the non-volatile components constituting the resin composition excluding the inorganic filler described below.

[0096] From the viewpoint of producing a cured product exhibiting excellent dielectric properties and heat resistance, the content of component (a) in the resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, and particularly preferably 4% by mass or more, based on 100% by mass of the nonvolatile components in the resin composition. The upper limit of the content is not particularly limited and may be determined depending on the properties required of the resin composition, but may be, for example, 100% by mass, or 99.5% by mass or less, 99% by mass or less, 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, 50% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, or 10% by mass or less.

[0097] <(b) Polymerization initiator> The resin composition of the present invention may contain (b) a polymerization initiator as an optional component, and preferably contains (b) a polymerization initiator. Even when the resin composition of the present invention contains only (a) a polyamideimide resin in which at least one of the main chain terminals is a maleimide group, it can be polymerized and cured by thermal radicals generated by heating, etc., but by containing (b) a polymerization initiator, the polymerization reaction proceeds more efficiently, resulting in a cured product exhibiting better dielectric properties and heat resistance. The (b) polymerization initiator may be used alone or in combination of two or more.

[0098] From the viewpoint of providing a cured product exhibiting better dielectric properties and heat resistance, the one-hour half-life temperature of the (b) polymerization initiator is preferably 100°C or higher, more preferably 110°C or higher, and even more preferably 120°C or higher. The upper limit is preferably 250°C or lower, more preferably 200°C or lower, and even more preferably 180°C or lower. The one-hour half-life indicates that it takes one hour for the amount of the polymerization initiator to be reduced to half, and the one-hour half-life temperature indicates the decomposition temperature of the polymerization initiator at which the one-hour half-life is obtained.

[0099] The polymerization initiator may be a compound capable of generating radicals upon heating, such as a peroxide-based polymerization initiator, an azo compound-based polymerization initiator, a persulfate compound-based polymerization initiator, or a redox-based polymerization initiator.

[0100] Examples of the peroxide polymerization initiator include hydroperoxide compounds such as 1,1,3,3-tetramethylbutyl hydroperoxide, p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, cumene hydroperoxide, and tert-butyl hydroperoxide; tert-butylcumyl peroxide, di-tert-butyl peroxide, di-tert-hexyl peroxide, dicumyl peroxide, and 1,4-bis(1-tert-butylperoxide). Dialkyl peroxide compounds such as 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,2-di(tert-butylperoxy)butane, di(2-tert-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexyne-3, and 2,3-dimethyl-2,3-diphenylbutane; dilauroyl peroxide, dide diacyl peroxide compounds such as hexanoyl peroxide, dicyclohexyl peroxydicarbonate, and bis(4-tert-butylcyclohexyl) peroxydicarbonate; tert-butyl peroxyacetate, tert-butyl peroxybenzoate, tert-hexyl peroxybenzoate, tert-butyl peroxyisopropyl monocarbonate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyneodecanoate, and tert-hexyl Examples of the peroxyester compounds include peroxyisopropyl monocarbonate, tert-butyl peroxylaurate, (1,1-dimethylpropyl) 2-ethylperhexanoate, tert-butyl 2-ethylperhexanoate, tert-butyl 3,5,5-trimethylperhexanoate, tert-butylperoxy-2-ethylhexyl monocarbonate, tert-butylperoxymaleic acid, and n-butyl-4,4-di(tert-butylperoxy)valerate.

[0101] The peroxide-based polymerization initiator is preferably either a hydroperoxide compound or a dialkyl peroxide compound, more preferably a dialkyl peroxide compound, and further preferably dicumyl peroxide.

[0102] Examples of the azo compound polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2-methylpropionitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4,4-trimethylpentane), 2,2'-azobis(2-methylpropane), 1,1'-azobis(cyclohexanecarbonitrile), and dimethyl-2,2'-azobisisobutyrate, with 2,2'-azobisisobutyronitrile being preferred.

[0103] Examples of the persulfate compound-based polymerization initiator include potassium persulfate.

[0104] Commercially available polymerization initiators can be used. Examples of commercially available polymerization initiators include "Perhexyl I", "Perbutyl 355", "Perbutyl L", "Perbutyl I", "Perbutyl E", "Perhexyl Z", "Perhexa 25Z", "Perbutyl A", "Perhexa 22", "Perbutyl Z", "Perhexa V", "Perbutyl P", "Percumyl D", "Perhexyl D", "Perhexa 25B", "Perbutyl C", "Perbutyl D", "Permenta H", "Perhexyne 25B", "Percumyl D", "Percumyl P", "Perocta H", "Percumyl H", "Perbutyl H", and "Nofumer BC", all manufactured by NOF Corporation.

[0105] When the resin composition of the present invention contains (b) a polymerization initiator, the content of (b) a polymerization initiator is, from the viewpoint of significantly obtaining the effects of the present invention, preferably 0.01% by mass or more or 0.05% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.15% by mass or more or 0.2% by mass or more, particularly preferably 0.3% by mass or more, 0.5% by mass or more, or 0.8% by mass or more, based on 100% by mass of the resin component of the resin composition. The upper limit is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, 3% by mass or less, or 2% by mass or less, and particularly preferably 1.5% by mass or less or 1% by mass or less.

[0106] When the resin composition of the present invention contains (b) a polymerization initiator, the content of (b) a polymerization initiator is, from the viewpoint of significantly achieving the effects of the present invention, preferably 0.0001% by mass or more or 0.001% by mass or more, more preferably 0.01% by mass or more, even more preferably 0.02% by mass or more or 0.04% by mass or more, based on 100% by mass of the non-volatile components of the resin composition. The upper limit is preferably 5% by mass or less, more preferably 3% by mass or less or 2% by mass or less, even more preferably 1.5% by mass or less or 1% by mass or less, and particularly preferably 0.5% by mass or less, 0.1% by mass or less, or 0.08% by mass or less.

[0107] When the resin composition of the present invention contains a polymerization initiator (b), the mass ratio of the polymerization initiator (b) to the component (a) [component (b) / component (a)] is, from the viewpoint of significantly achieving the effects of the present invention, preferably 0.0001 or more or 0.001 or more, more preferably 0.002 or more or 0.005 or more, and even more preferably 0.008 or more or 0.01 or more. The upper limit is preferably 1 or less, more preferably 0.5 or less or 0.1 or less, and even more preferably 0.08 or less, 0.05 or less, or 0.02 or less.

[0108] When the resin composition of the present invention contains a polymerization initiator (b), the total content of the components (a) and (b) is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, 20% by mass or more, 22% by mass or more, or 23% by mass or more, based on 100% by mass of the resin components of the resin composition. The upper limit of the content is not particularly limited and may be determined depending on the properties required of the resin composition. For example, it may be 100% by mass, or 99.5% by mass or less, 99% by mass or less, 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, 50% by mass or less, 40% by mass or less, or 30% by mass or less.

[0109] <(c) Other curable resins> The resin composition of the present invention may contain (c) another curable resin as an optional component. The type of (c) another curable resin is not particularly limited as long as it can be cured, but from the viewpoint of being able to produce a cured product exhibiting better dielectric properties and heat resistance, it is preferable that it be one or more types selected from the group consisting of thermosetting resins and radically polymerizable resins. The (c) other curable resin may be used alone or in combination of two or more types.

[0110] Examples of thermosetting resins include epoxy resins (hereinafter, the epoxy resin contained in the resin composition is also referred to as "component (c1)" and sometimes written as "(c1) epoxy resin"), benzocyclobutene resins, epoxy acrylate resins, urethane acrylate resins, urethane resins, cyanate resins, polyimide resins, benzoxazine resins, unsaturated polyester resins, and melamine resins, with (c1) epoxy resins being preferred. Epoxy resins are curable resins having epoxy groups and an epoxy equivalent of 5,000 g / eq. or less. Thermosetting resins may be used singly or in combination of two or more.

[0111] The type of (c1) epoxy resin is not particularly limited as long as it has one or more (preferably two or more) epoxy groups in one molecule. Examples of (c1) epoxy resins include bixylenol-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 resins, phenol aralkyl-type epoxy resins, and biphenyl-type epoxy resins. Examples of the epoxy resin include biphenylaralkyl-type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexane-type epoxy resins, cyclohexanedimethanol-type epoxy resins, naphthylene ether-type epoxy resins, trimethylol-type epoxy resins, tetraphenylethane-type epoxy resins, isocyanurate-type epoxy resins, phenolphthalimidine-type epoxy resins, glycerol-type epoxy resins, alkyleneoxy skeleton-containing epoxy resins, fluorene structure-containing epoxy resins, and halogenated epoxy resins, with bisphenol A-type epoxy resins and biphenylaralkyl-type epoxy resins being preferred. (c1) The epoxy resin may be used alone or in combination of two or more.

[0112] The resin composition of the present invention preferably contains, as component (c1), an epoxy resin having two or more epoxy groups per molecule. From the viewpoint of significantly achieving the desired effects of the present invention, the proportion of the epoxy resin having two or more epoxy groups per molecule relative to 100% by mass of the epoxy resin (c1) is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more.

[0113] The (c1) epoxy resin includes an epoxy resin that is liquid at a temperature of 20°C (hereinafter sometimes referred to as a "liquid epoxy resin") and an epoxy resin that is solid at a temperature of 20°C (hereinafter sometimes referred to as a "solid epoxy resin"). The resin composition of the present invention may contain, as component (c1), only a liquid epoxy resin, only a solid epoxy resin, or a combination of a liquid epoxy resin and a solid epoxy resin. In one embodiment, the resin composition of the present invention preferably contains a combination of a liquid epoxy resin and a solid epoxy resin.

[0114] The liquid epoxy resin is preferably a liquid epoxy resin having two or more epoxy groups in one molecule.

[0115] Examples of liquid epoxy resins include glycerol-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol AF-type epoxy resins, naphthalene-type epoxy resins, glycidyl ester-type epoxy resins, glycidyl amine-type epoxy resins, phenol novolac-type epoxy resins, alicyclic epoxy resins having an ester skeleton, cyclohexanedimethanol-type epoxy resins, cyclic aliphatic glycidyl ethers, epoxy resins having a butadiene structure, dicyclopentadiene-type epoxy resins, alkyleneoxy-skeleton-containing epoxy resins, and fluorene-structure-containing epoxy resins, with bisphenol A-type epoxy resins being preferred.

[0116] Specific examples of liquid epoxy resins include "EX-992L" manufactured by Nagase ChemteX Corporation, "YX7400" manufactured by Mitsubishi Chemical Corporation, "HP4032", "HP4032D", and "HP4032SS" (naphthalene-type epoxy resins) manufactured by DIC Corporation; "828US", "jER828EL", "828EL", "825", and "Epikote 828EL" manufactured by Mitsubishi Chemical Corporation, and "850S" (bisphenol A-type epoxy resin) manufactured by DIC Corporation; and "jER8" manufactured by Mitsubishi Chemical Corporation. 07, 1750 (bisphenol F type epoxy resin); Mitsubishi Chemical Corporation's jER152 (phenol novolac type epoxy resin); Mitsubishi Chemical Corporation's 630, 630LSD, and 604 (glycidylamine type epoxy resin); ADEKA Corporation's ED-523T (glycirol type epoxy resin); ADEKA Corporation's EP-3950L and EP-3980S (glycidylamine type epoxy resin); ADEKA Corporation's EP-4088S (dicyclopentadiene type epoxy resin); Nippon Steel Chemical & Material Corporation's ZX-1059 (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin); Nagase ChemteX Corporation's EX-721 (glycidyl ester type epoxy resin); Nagase ChemteX Corporation's EX-991L (alkyleneoxy skeleton-containing epoxy resin); Daicel Corporation's Celloxide 2021P (alicyclic epoxy resin with ester skeleton) epoxy resins); "PB-3600" manufactured by Daicel Corporation, "JP-100" and "JP-200" manufactured by Nippon Soda Co., Ltd. (epoxy resins having a butadiene structure); "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane-type epoxy resins) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "EG-280" (fluorene structure-containing epoxy resin) manufactured by Osaka Gas Chemicals Co., Ltd.; and "EX-201" (cyclic aliphatic glycidyl ether) manufactured by Nagase ChemteX Corporation. These may be used alone or in combination of two or more.

[0117] As the solid epoxy resin, a solid epoxy resin having two or more epoxy groups in one molecule is preferred, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is more preferred.

[0118] Examples of solid epoxy resins include bixylenol-type epoxy resins, naphthalene-type epoxy resins, naphthalene-type tetrafunctional epoxy resins, naphthol novolac-type epoxy resins, cresol novolac-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol-type epoxy resins, biphenyl-type epoxy resins, biphenylaralkyl-type epoxy resins, naphthylene ether-type epoxy resins, anthracene-type epoxy resins, bisphenol A-type epoxy resins, bisphenol AF-type epoxy resins, phenolaralkyl-type epoxy resins, tetraphenylethane-type epoxy resins, phenolphthalimidine-type epoxy resins, and fluorene-structure-containing epoxy resins, with biphenylaralkyl-type epoxy resins being preferred.

[0119] Specific examples of solid epoxy resins include "HP4032H" (naphthalene-type epoxy resin) manufactured by DIC Corporation; "HP-4700" and "HP-4710" (naphthalene-type tetrafunctional epoxy resins) manufactured by DIC Corporation; "N-690" and "N-695" (cresol novolac-type epoxy resins) manufactured by DIC Corporation; "HP-7200", "HP-7200HH", "HP-7200H", and "HP-7200L" (dicyclopentadiene-type epoxy resins) manufactured by DIC Corporation; and "EXA-7311", "EXA-7311-G3", and "EXA-7311-G4" manufactured by DIC Corporation. "," "EXA-7311-G4S," "HP-6000," and "HP-6000L" (naphthylene ether type epoxy resins); "EPPN-502H" (trisphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC7000L" (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC3000," "NC3000L," "NC3000FH," and "NC3100" (biphenyl type epoxy resins) manufactured by Nippon Kayaku Co., Ltd.; "NC3000H" (biphenyl aralkyl type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ESN475V" manufactured by Nippon Steel Chemical & Material Co., Ltd. "," ESN4100V" (naphthalene-type epoxy resin); "ESN485" (naphthol-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ESN375" (dihydroxynaphthalene-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YX4000", "YX4000HK", "YL7890" (bixylenol-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL6121" (biphenyl-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX8800" (anthracene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; Examples include "YX7700" (phenol aralkyl type epoxy resin); "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals Co., Ltd.; "YL7760" (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL7800" (fluorene structure-containing epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1010" (bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical Corporation; and "WHR991S" (phenolphthalimidine type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.These may be used alone or in combination of two or more.

[0120] The epoxy equivalent of the (c1) epoxy resin is preferably 50 to 5000 g / eq. The lower limit of the epoxy equivalent is more preferably 60 g / eq. or more, even more preferably 80 g / eq. or more, and particularly preferably 110 g / eq. or more. The upper limit of the epoxy equivalent is preferably 3000 g / eq. or less, more preferably 2000 g / eq. or less, even more preferably 1000 g / eq. or less, and particularly preferably 500 g / eq. or less. The epoxy equivalent is the mass of an epoxy resin containing one equivalent of epoxy groups, and can be measured in accordance with JIS K7236.

[0121] The weight average molecular weight (Mw) of the (c1) epoxy resin is preferably 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500. The weight average molecular weight (Mw) of the epoxy resin can be measured by the GPC method as a polystyrene-equivalent value.

[0122] The radical polymerizable resin is not particularly limited as long as it has one or more (preferably two or more) radical polymerizable unsaturated groups per molecule. Examples of the radical polymerizable resin include resins having one or more radical polymerizable unsaturated groups selected from maleimide, vinyl, allyl, styryl, vinylphenyl, acryloyl, methacryloyl, fumaroyl, and maleoyl groups. However, those corresponding to component (a) are excluded. In particular, from the viewpoint of producing a cured product with exceptionally excellent dielectric and mechanical properties, it is preferable that the radical polymerizable resin further contains one or more selected from other maleimide resins, (meth)acrylic resins, and styryl resins. Here, "other maleimide resins" means "resins having a maleimide group other than (a) polyamideimide resins in which at least one terminal of the main chain is a maleimide group." "(Meth)acrylic resin" means a resin having an acryloyl or methacryloyl group. The term "styryl resin" refers to a resin having a styryl group or a vinylphenyl group. The radical polymerizable resin may be used alone or in combination of two or more.

[0123] The other maleimide resin is not particularly limited in type as long as it has one or more (preferably two or more) maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl groups) in one molecule and does not fall under component (a). Examples of maleimide resins include maleimide resins containing an aliphatic skeleton with 36 carbon atoms derived from dimer diamine, such as "BMI-3000J," "BMI-5000," "BMI-1400," "BMI-1500," "BMI-1700," and "BMI-689" (all manufactured by Designer Molecules Inc.); maleimide resins containing an indane skeleton, as described in the Japan Institute of Invention and Innovation's Technical Disclosure Bulletin No. 2020-500211; and maleimide resins containing an aromatic ring skeleton directly bonded to the nitrogen atom of the maleimide group, such as "MIR-3000-70MT" (manufactured by Nippon Kayaku Co., Ltd.), "BMI-4000" (manufactured by Daiwa Kasei Co., Ltd.), and "BMI-80" (manufactured by Keiai Kasei Co., Ltd.).

[0124] The (meth)acrylic resin may be a monomer or an oligomer, and is not particularly limited as long as it has one or more (preferably two or more) (meth)acryloyl groups in one molecule. Here, the term "(meth)acryloyl group" is a general term for acryloyl groups and methacryloyl groups. Examples of (meth)acrylic resins include "A-DOG" (manufactured by Shin-Nakamura Chemical Co., Ltd.), "DCP-A" (manufactured by Kyoeisha Chemical Co., Ltd.), "NPDGA," "FM-400," "R-687," "THE-330," "PET-30," and "DPHA" (all manufactured by Nippon Kayaku Co., Ltd.).

[0125] The styryl resin is not particularly limited in type, and may be a monomer or oligomer, as long as it has one or more (preferably two or more) styryl groups or vinylphenyl groups in one molecule. Examples of the styryl resin include styryl resins such as "OPE-2St," "OPE-2St 1200," and "OPE-2St 2200" (all manufactured by Mitsubishi Gas Chemical Company, Inc.).

[0126] The resin composition of the present invention may further include, as (c) other curable resin, only a thermosetting resin, only a radical polymerizable resin, or a combination of a thermosetting resin and a radical polymerizable resin. In one embodiment, the resin composition of the present invention preferably includes, as (c) other curable resin, a thermosetting resin, and more preferably includes (c1) an epoxy resin.

[0127] When the resin composition of the present invention contains (c) another curable resin, the content of (c) another curable resin in the resin composition is, from the viewpoint of significantly obtaining the effects of the present invention, preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, 20% by mass or more, 25% by mass or more, or 30% by mass or more, and particularly preferably 32% by mass or more, or 34% by mass or more, based on 100% by mass of the resin components in the resin composition. The upper limit is preferably 60% by mass or less or 55% by mass or less, more preferably 50% by mass or less or 45% by mass or less, and even more preferably 40% by mass or less or 35% by mass or less.

[0128] When the resin composition of the present invention contains (c) another curable resin, the content of (c) another curable resin in the resin composition is, from the viewpoint of significantly obtaining the effects of the present invention, preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, particularly preferably 4% by mass or more, 5% by mass or more, or 6% by mass or more, based on 100% by mass of the nonvolatile components in the resin composition. The upper limit is preferably 30% by mass or less or 25% by mass or less, more preferably 20% by mass or less or 15% by mass or less, and even more preferably 10% by mass or less or 8% by mass or less.

[0129] When the resin composition of the present invention contains another curable resin (c), the mass ratio of the other curable resin (c) to the component (a) [component (c) / component (a)] is, from the viewpoint of significantly obtaining the effects of the present invention, preferably 0.05 or more, 0.1 or more, or 0.3 or more, more preferably 0.5 or more or 0.8 or more, even more preferably 1 or more or 1.2 or more, and particularly preferably 1.3 or more or 1.4 or more. The upper limit is preferably 50 or less, 20 or less, or 10 or less, more preferably 8 or less or 5 or less, even more preferably 4 or less or 3 or less, and particularly preferably 2 or less, 1.8 or less, 1.6 or less, or 1.5 or less.

[0130] When the resin composition of the present invention contains (b) a polymerization initiator and (c) another curable resin, the mass ratio of (c) another curable resin to (b) the polymerization initiator [(c) component / (b) component] is, from the viewpoint of significantly obtaining the effects of the present invention, preferably 10 or more or 20 or more, more preferably 30 or more or 50 or more, even more preferably 60 or more, 80 or more, or 100 or more. The upper limit is preferably 10,000 or less or 5,000 or less, more preferably 1,000 or less or 500 or less, even more preferably 400 or less, 300 or less or 200 or less, and particularly preferably 150 or less or 120 or less.

[0131] When the resin composition of the present invention contains (c) another curable resin, the total content of the components (a) and (c) in the resin composition is, from the viewpoint of significantly achieving the effects of the present invention, preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, 40% by mass or more, 45% by mass or more, or 50% by mass or more, and particularly preferably 55% by mass or more, based on 100% by mass of the resin components in the resin composition. The upper limit is not particularly limited and may be determined depending on the properties required of the resin composition. For example, it may be 100% by mass, or may be 99.5% by mass or less, 99% by mass or less, 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, etc.

[0132] When the resin composition of the present invention contains (b) a polymerization initiator and (c) another curable resin, the total content of the (a), (b), and (c) components in the resin composition is, from the viewpoint of significantly achieving the effects of the present invention, preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, 40% by mass or more, 45% by mass or more, or 50% by mass or more, and particularly preferably 55% by mass or more, based on 100% by mass of the resin components in the resin composition. The upper limit is not particularly limited and may be determined depending on the properties required of the resin composition. For example, it may be 100% by mass, or may be 99.5% by mass or less, 99% by mass or less, 90% by mass or less, 80% by mass or less, 70% by mass or less, or 60% by mass or less.

[0133] When the resin composition of the present invention contains (c1) an epoxy resin as (c) other curable resin, preferred aspects of the content of (c1) epoxy resin and the mass ratio to other components are the same as the preferred aspects of the content of (c) other curable resin and the mass ratio to other components.

[0134] <(d) Hardener> The resin composition of the present invention may further contain (d) a curing agent as an optional component. The (d) curing agent has the function of curing the resin composition by reacting with (a) a polyamideimide resin having a maleimide group at least on one end of the main chain or (c) another curable resin. The (d) curing agent may be used alone or in combination of two or more.

[0135] Even when the resin composition of the present invention contains only (a) a polyamideimide resin in which at least one end of the main chain is a maleimide group, it can be polymerized and cured by thermal radicals generated by heating, etc. However, by including a (d) curing agent, the curing reaction proceeds more efficiently, resulting in a cured product exhibiting superior dielectric properties and heat resistance. Furthermore, when the resin composition of the present invention contains (c) another curable resin, it can be cured by reaction between the (c) other curable resins without including a (d) curing agent. However, by including a (d) curing agent, the curing reaction proceeds more efficiently, resulting in a cured product exhibiting superior dielectric properties and heat resistance. In one embodiment, when the resin composition of the present invention contains (c1) an epoxy resin, it is preferable to include a (d1) epoxy resin curing agent as the (d) curing agent.

[0136] The reactive group equivalent of the (d) curing agent is preferably 50 g / eq. to 3,000 g / eq., more preferably 100 g / eq. to 1,000 g / eq., even 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 (d) curing agent per equivalent of the reactive group.

[0137] From the viewpoint of producing a cured product exhibiting excellent dielectric properties, the resin composition of the present invention preferably contains an active ester resin as the curing agent (d). The active ester resin can function as an epoxy resin curing agent (d1). When an active ester resin is used as the curing agent (d), good dielectric properties are easily obtained, but smear removability during via hole formation may be impaired. In contrast, the resin composition of the present invention containing the polyamide-imide resin (a) in which at least one end of the main chain is a maleimide group can produce a cured product with excellent smear removability even when an active ester resin is used as the curing agent. This, combined with the good dielectric properties inherently exhibited by the active ester resin, allows for the realization of a cured product that combines excellent dielectric properties and smear removability. Therefore, in a preferred embodiment, the curing agent (d) in the resin composition of the present invention contains an active ester resin.

[0138] As the active ester resin, a compound having one or more active ester groups per molecule can be used. Among them, preferred active ester resins are compounds having two or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. The active ester resin is preferably one obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester resin obtained from a carboxylic acid compound and a hydroxy compound is preferred, and an active ester resin obtained from a carboxylic acid compound and a phenol compound and / or a naphthol compound is more preferred.

[0139] Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.

[0140] Examples of phenol compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalene, 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, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, and phenol novolak. Here, "dicyclopentadiene-type diphenol compounds" refers to diphenol compounds obtained by condensing one dicyclopentadiene molecule with two phenol molecules.

[0141] Specific preferred examples of the active ester resin include an active ester resin containing a dicyclopentadiene-type diphenol structure (hereinafter also referred to as "dicyclopentadiene-type active ester resin"), an active ester resin containing a naphthalene structure, a phosphorus-containing active ester resin, an active ester resin containing an acetylated product of phenol novolac, and an active ester resin containing a benzoylated product of phenol novolac. Among these, an active ester resin containing a naphthalene structure and an active ester resin containing a dicyclopentadiene-type diphenol structure are preferred, and an active ester resin containing a dicyclopentadiene-type diphenol structure is more preferred. The "dicyclopentadiene-type diphenol structure" refers to a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

[0142] Commercially available activated ester resins include "EXB9451", "EXB9460", "EXB9460S", "HPC-8000-62T", "HPC-8000-65T", "HPC-8000H", "HPC-8000H-65TM", and "EXB-8000L-65TM" (manufactured by DIC Corporation) as activated ester resins containing a dicyclopentadiene-type diphenol structure; and "HP-B-8151-62T", "EXB-9416-70BK", "EXB-8100L-65T", "EXB-8150L-65T", "EXB-8150-65T", "HPC-8150-60T", and "HPC-8150-62" as naphthalene-type activated ester resins containing a naphthalene structure. Examples of active ester resins that can be used include "HPC-8100L-65T", "HPB-8151-62T", "EXB-8" (manufactured by DIC Corporation), "PC1300-02-65T", and "PC1300-02-65MA" (manufactured by Air Water Inc.); phosphorus-containing active ester resins include "EXB-9401" (manufactured by DIC Corporation); active ester resins containing acetylated phenol novolac include "DC808" (manufactured by Mitsubishi Chemical Corporation); and active ester resins that are benzoylated phenol novolac include "YLH1026" (manufactured by Mitsubishi Chemical Corporation), "YLH1030" (manufactured by Mitsubishi Chemical Corporation), "YLH1048" (manufactured by Mitsubishi Chemical Corporation), and "EXB-8500-65T" (manufactured by DIC Corporation).

[0143] When the resin composition of the present invention contains an active ester resin, the content of the active ester resin in the resin composition is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, 20% by mass or more, 25% by mass or more, 26% by mass or more, 28% by mass or more, 30% by mass or more, or 32% by mass or more, based on 100% by mass of the resin components in the resin composition, from the viewpoint of obtaining a cured product exhibiting excellent dielectric properties. The upper limit of the content is preferably 70% by mass or less or 60% by mass or less, more preferably 50% by mass or less or 45% by mass or less, and even more preferably 40% by mass or less or 35% by mass or less, based on 100% by mass of the resin components in the resin composition, from the viewpoint of obtaining a cured product exhibiting good mechanical properties.

[0144] When the resin composition of the present invention contains an active ester resin, the content of the active ester resin in the resin composition is preferably 1% by mass or more or 2% by mass or more, more preferably 3% by mass or more or 4% by mass or more, and even more preferably 5% by mass or more or 6% by mass or more, based on 100% by mass of the nonvolatile components in the resin composition, from the viewpoint of obtaining a cured product exhibiting excellent dielectric properties. The upper limit of the content is preferably 70% by mass or less or 60% by mass or less, more preferably 50% by mass or less, 45% by mass or less or 40% by mass or less, even more preferably 30% by mass or less or 20% by mass or less, and particularly preferably 15% by mass or less, 10% by mass or less or 8% by mass or less, based on 100% by mass of the nonvolatile components in the resin composition, from the viewpoint of obtaining a cured product exhibiting good mechanical properties.

[0145] When the resin composition of the present invention contains an active ester resin, the mass ratio of the active ester resin to component (a) [active ester resin / component (a)] is preferably 0.1 or more, 0.2 or more, or 0.3 or more, more preferably 0.5 or more, even more preferably 0.6 or more, 0.7 or more, 0.8 or more, 0.9 or more, or 1 or more, and particularly preferably 1.1 or more, 1.2 or more, 1.3 or more, or 1.4 or more, from the viewpoint of providing a cured product exhibiting even better dielectric properties and excellent mechanical properties. The upper limit of this mass ratio [active ester resin / component (a)] is preferably 50 or less, 20 or less, or 10 or less, more preferably 8 or less, 5 or less, even more preferably 4 or less, or 3 or less, and particularly preferably 2 or less, 1.8 or less, 1.6 or less, or 1.5 or less.

[0146] The resin composition of the present invention may further contain a curing agent other than the active ester resin. Examples of the curing agent other than the active ester resin include a phenol-based curing agent, a carbodiimide-based curing agent, an acid anhydride-based curing agent, an amine-based curing agent, a benzoxazine-based curing agent, a cyanate ester-based curing agent, and a thiol-based curing agent. The phenol-based curing agent, the carbodiimide-based curing agent, the acid anhydride-based curing agent, the amine-based curing agent, the benzoxazine-based curing agent, the cyanate ester-based curing agent, and the thiol-based curing agent can function as the (d1) epoxy resin curing agent.

[0147] As the phenolic curing agent, a curing agent having one or more, preferably two or more, hydroxyl groups (phenolic hydroxyl groups) bonded to an aromatic ring such as a benzene ring or a naphthalene ring per molecule can be used. From the viewpoint of heat resistance and water resistance, phenolic curing agents having a novolac structure are preferred. Furthermore, from the viewpoint of adhesion to the adherend, nitrogen-containing phenolic curing agents are preferred, and triazine skeleton-containing phenolic curing agents are more preferred. Among these, triazine skeleton-containing phenolic novolac resins are preferred from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion.

[0148] Specific examples of phenolic curing agents include "MEH-7700," "MEH-7810," "MEH-7851," "MEH-7600," "MEH-7851," and "MEH-8000H" manufactured by UBE Corporation; "NHN," "CBN," "GPH," "GPH-65," and "GPH-103" manufactured by Nippon Kayaku Co., Ltd.; "SN-170," "SN-180," "SN-190," "SN-475," "SN-485," "SN-495," "SN-375," and "SN-395" manufactured by Nippon Steel Chemical & Material Co., Ltd.; and "LA-7052," "LA-7054," "LA-3018," "LA-3018-50P," "LA-1356," "TD-2090," "TD2131," "TD-2090-60M," and "KA-1160" manufactured by DIC Corporation. These may be used alone or in combination of two or more.

[0149] Examples of carbodiimide curing agents include curing agents having one or more, preferably two or more, carbodiimide structures in one molecule, such as aliphatic biscarbodiimides such as tetramethylene-bis(t-butylcarbodiimide) and cyclohexane-bis(methylene-t-butylcarbodiimide); biscarbodiimides such as aromatic biscarbodiimides such as phenylene-bis(xylylcarbodiimide); aliphatic polycarbodiimides such as polyhexamethylenecarbodiimide, polytrimethylhexamethylenecarbodiimide, polycyclohexylenecarbodiimide, poly(methylenebiscyclohexylenecarbodiimide), and poly(isophoronecarbodiimide); Examples of suitable polycarbodiimides include aromatic polycarbodiimides such as poly(phenylenecarbodiimide), poly(naphthylenecarbodiimide), poly(tolylenecarbodiimide), poly(methyldiisopropylphenylenecarbodiimide), poly(triethylphenylenecarbodiimide), poly(diethylphenylenecarbodiimide), poly(triisopropylphenylenecarbodiimide), poly(diisopropylphenylenecarbodiimide), poly(xylylenecarbodiimide), poly(tetramethylxylylenecarbodiimide), poly(methylenediphenylenecarbodiimide), and poly[methylenebis(methylphenylene)carbodiimide]. These may be used alone or in combination of two or more.

[0150] Commercially available carbodiimide curing agents include, for example, "Carbodilite V-02B," "Carbodilite V-03," "Carbodilite V-04K," "Carbodilite V-07," and "Carbodilite V-09" manufactured by Nisshinbo Chemical Inc.; and "Stavaxol P," "Stavaxol P400," and "Hykasil 510" manufactured by Lanxess AG. These may be used alone or in combination of two or more.

[0151] The acid anhydride curing agent may be a curing agent having one or more acid anhydride groups in one molecule, and a curing agent having two or more acid anhydride groups in one molecule is preferred. Specific examples of the acid anhydride curing agent include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic dianhydride. Examples of suitable acid anhydrides include anhydrides, biphenyltetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(anhydrotrimellitate), and polymeric acid anhydrides such as styrene-maleic acid resins, which are copolymers of styrene and maleic acid. These may be used alone or in combination of two or more.

[0152] Commercially available acid anhydride curing agents include "HNA-100," "MH-700," "MTA-15," "DDSA," and "OSA" manufactured by New Japan Chemical Co., Ltd.; "YH-306" and "YH-307" manufactured by Mitsubishi Chemical Corporation; "HN-2200" and "HN-5500" manufactured by Resonac Corporation; and "EF-30," "EF-40," "EF-60," and "EF-80" manufactured by Cray Valley Chemical Industries, Ltd. These may be used alone or in combination of two or more.

[0153] Examples of amine-based curing agents include curing agents having one or more, preferably two or more, amino groups in one molecule. The amino group of the amine-based curing agent is preferably a primary amino group or a secondary amino group, more preferably a primary amino group. Examples of amine-based curing agents include aliphatic amines, polyether amines, alicyclic amines, and aromatic amines, and among these, aromatic amines are preferred from the viewpoint of achieving the desired effects of the present invention. The amine-based curing agent is preferably a primary amine or a secondary amine, more preferably a primary amine.

[0154] Specific examples of amine-based curing agents include 4,4'-methylenebis(2,6-dimethylaniline), 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, and 2,2-bis(3-amino-4-hydroxyphenyl)propane. propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, bis(4-(3-aminophenoxy)phenyl)sulfone, and the like. Commercially available amine-based curing agents may be used, and examples thereof include "SEIKACURE-S" manufactured by Seika Corporation, "KAYABOND C-200S," "KAYABOND C-100," "KAYAHARD AA," "KAYAHARD AB," and "KAYAHARD AS" manufactured by Nippon Kayaku Co., Ltd., "Epicure W" manufactured by Mitsubishi Chemical Corporation, and "DTDA" manufactured by Sumitomo Seika Chemicals Co., Ltd. These may be used alone or in combination of two or more.

[0155] Specific examples of benzoxazine curing agents include "JBZ-OP100D" and "ODA-BOZ" manufactured by JFE Chemical Corporation, "HFB2006M" manufactured by Showa Polymer Co., Ltd., and "Pd" and "Fa" manufactured by Shikoku Chemicals Corporation. These may be used alone or in combination of two or more.

[0156] Examples of cyanate ester curing agents include bifunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate (oligo(3-methylene-1,5-phenylene cyanate)), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylidene diphenyl 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)thioether, and bis(4-cyanatephenyl)ether; multifunctional cyanate resins derived from phenol novolac and cresol novolac; and prepolymers in which these cyanate resins are partially converted to triazine. Specific examples of cyanate ester curing agents include "PT30" and "PT60" (both phenol novolac type multifunctional cyanate ester resins) manufactured by Arxada, "BA230" and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate is triazinated to form a trimer), etc. These may be used alone or in combination of two or more.

[0157] Examples of thiol-based curing agents include trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), tris(3-mercaptopropyl)isocyanurate, etc. These may be used alone or in combination of two or more.

[0158] When the resin composition of the present invention contains a curing agent other than the active ester resin, the content of the curing agent other than the active ester resin in the resin composition may be determined depending on the properties required of the resin composition, but is preferably 40% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less, based on 100% by mass of the resin component in the resin composition. The lower limit can be 0.01% by mass or more, 0.05% by mass or more, 0.1% by mass or more, etc.

[0159] When the resin composition of the present invention contains a (d) curing agent, the content of the (d) curing agent in the resin composition is, from the viewpoint of significantly obtaining the effects of the present invention, preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, 20% by mass or more, 25% by mass or more, 26% by mass or more, 28% by mass or more, 30% by mass or more, or 32% by mass or more, based on 100% by mass of the resin components in the resin composition. The upper limit of the content is preferably 70% by mass or less or 60% by mass or less, more preferably 50% by mass or less or 45% by mass or less, and even more preferably 40% by mass or less or 35% by mass or less.

[0160] When the resin composition of the present invention contains a (d) curing agent, the content of the (d) curing agent in the resin composition is, from the viewpoint of significantly achieving the effects of the present invention, preferably 1% by mass or more or 2% by mass or more, more preferably 3% by mass or more or 4% by mass or more, and even more preferably 5% by mass or more or 6% by mass or more, based on 100% by mass of the nonvolatile components in the resin composition. The upper limit of the content is preferably 70% by mass or less or 60% by mass or less, more preferably 50% by mass or less, 45% by mass or less or 40% by mass or less, even more preferably 30% by mass or less or 20% by mass or less, and particularly preferably 15% by mass or less, 10% by mass or less or 8% by mass or less.

[0161] When the resin composition of the present invention contains a (d) curing agent, the mass ratio of the (d) curing agent to the (a) component [(d) / component (a)] is, from the viewpoint of significantly achieving the effects of the present invention, preferably at least 0.1, 0.2, or 0.3, more preferably at least 0.5, even more preferably at least 0.6, 0.7, 0.8, 0.9, or 1, and particularly preferably at least 1.1, 1.2, 1.3, or 1.4. The upper limit of the mass ratio [component (d) / component (a)] is preferably 50, 20, or 10, more preferably 8 or 5, even more preferably 4 or 3, and particularly preferably 2, 1.8, 1.6, or 1.5.

[0162] When the resin composition of the present invention contains a (b) polymerization initiator and a (d) curing agent, the mass ratio of the (d) curing agent to the (b) polymerization initiator [(d) component / (b) component], from the viewpoint of significantly obtaining the effects of the present invention, is preferably 10 or more or 20 or more, more preferably 30 or more or 50 or more, even more preferably 60 or more, 80 or more, or 100 or more. The upper limit is preferably 10,000 or less or 5,000 or less, more preferably 1,000 or less or 500 or less, even more preferably 400 or less, 300 or less or 200 or less, and particularly preferably 150 or less or 120 or less.

[0163] When the resin composition of the present invention contains (c) another curable resin and (d) a curing agent, the mass ratio of the (d) curing agent to the (c) another curable resin [(d) component / (c) component] is, from the viewpoint of significantly achieving the effects of the present invention, preferably at least 0.1, at least 0.2, or at least 0.3, more preferably at least 0.5, even more preferably at least 0.6, at least 0.7, at least 0.8, or at least 0.9. The upper limit of the mass ratio [(d) component / (c) component] is preferably at most 50, at most 20, or at most 10, more preferably at most 8 or at most 5, even more preferably at most 4 or at most 3, and particularly preferably at most 2, at most 1.5, or at most 1.2.

[0164] When the resin composition of the present invention contains (b) a polymerization initiator, (c) another curable resin, and (d) a curing agent, the total content of components (a), (b), (c), and (d) is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, 80% by mass or more, 85% by mass or more, or 90% by mass or more, based on 100% by mass of the resin components of the resin composition. The upper limit of the content is not particularly limited and may be determined depending on the properties required of the resin composition. For example, it may be 100% by mass, or may be 99.9% by mass or less, 99.5% by mass or less, 99% by mass or less, 98% by mass or less, 96% by mass or less, or 95% by mass or less.

[0165] When the resin composition of the present invention contains (d1) an epoxy resin curing agent as (d) a curing agent, preferred aspects of the content of (d1) an epoxy resin curing agent and the mass ratio to other components are the same as the preferred aspects of the content of (d) a curing agent and the mass ratio to other components.

[0166] <(e) Curing accelerator> The resin composition of the present invention may contain, as an optional component, (e) a curing accelerator (c) which functions as a curing catalyst to accelerate the curing of (a) a polyamide-imide resin having a maleimide group at least on one end of its main chain and (c) another curable resin.

[0167] Examples of the (e) curing accelerator include phosphorus-based curing accelerators, urea-based curing accelerators, guanidine-based curing accelerators, imidazole-based curing accelerators, metal-based curing accelerators, and amine-based curing accelerators. The (e) curing accelerator preferably includes an amine-based curing accelerator. The (c) curing accelerators may be used alone or in combination of two or more.

[0168] Examples of the amine curing accelerator include trialkylamines such as triethylamine and tributylamine, pyridines such as 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene, among which pyridines are preferred, and 4-dimethylaminopyridine is more preferred. These may be used alone or in combination of two or more.

[0169] As the amine-based curing accelerator, commercially available products may be used, such as "MY-25" manufactured by Ajinomoto Fine-Techno Co., Ltd. and "DMAP" manufactured by Koei Chemical Industry Co., Ltd.

[0170] Examples of the phosphorus-based curing accelerator include aliphatic phosphonium salts such as tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, bis(tetrabutylphosphonium)pyromellitate, tetrabutylphosphonium hydrogenhexahydrophthalate, tetrabutylphosphonium 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenolate, and di-tert-butylmethylphosphonium tetraphenylborate; methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, p-tolyltriphenylphosphonium tetra-p-tolylborate, and tetraphenylphosphonium bromide. aromatic phosphonium salts such as tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, triphenylethylphosphonium tetraphenylborate, tris(3-methylphenyl)ethylphosphonium tetraphenylborate, tris(2-methoxyphenyl)ethylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate; aromatic phosphine-borane complexes such as triphenylphosphine-triphenylborane; aromatic phosphine-quinone adducts such as triphenylphosphine-p-benzoquinone adduct; aliphatic phosphines such as tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, di-tert-butyl(2-butenyl)phosphine, di-tert-butyl(3-methyl-2-butenyl)phosphine, and tricyclohexylphosphine;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-dimethylphenyl)phosphine Examples of aromatic phosphines include 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. These may be used alone or in combination of two or more.

[0171] Examples of the urea-based curing accelerator include 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, and 3-(3,4-dimethylphenyl)-1,1-dimethylurea. and aromatic dimethylureas such as toluenebis(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), and N,N-(4-methyl-1,3-phenylene)bis(N',N'-dimethylurea) [toluenebisdimethylurea]. These may be used alone or in combination of two or more.

[0172] Examples of guanidine curing 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-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, and 1-(o-tolyl)biguanide. These may be used alone or in combination of two or more.

[0173] Examples of the imidazole curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 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-phenylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, and 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine. 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-phenylimidazole isocyanuric acid adduct, 2-phenyl- Examples include imidazole compounds such as 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, and 2-phenylimidazoline, as well as adducts of imidazole compounds with epoxy resins.

[0174] Commercially available imidazole curing accelerators include, for example, "1B2PZ," "2E4MZ," "2MZA-PW," "2MZ-OK," "2MA-OK," "2MA-OK-PW," "2P4MZ," "2PHZ," "2PHZ-PW," "Cl1Z," "Cl1Z-CN," "Cl1Z-CNS," and "C11Z-A" manufactured by Shikoku Chemical Industry Co., Ltd.; and "P200-H50" manufactured by Mitsubishi Chemical Corporation. These may be used alone or in combination of two or more.

[0175] Examples of metal-based curing accelerators include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic 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 organometallic salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate. These may be used alone or in combination of two or more.

[0176] When the resin composition of the present invention contains (e) a curing accelerator, the content of (e) the curing accelerator in the resin composition may be determined depending on the properties required of the resin composition, but is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 1% by mass or less, particularly preferably 0.7% by mass or less or 0.5% by mass or less, when the resin components in the resin composition are taken as 100% by mass. The lower limit is preferably 0.001% by mass or more, more preferably 0.01% by mass or more or 0.05% by mass or more, even more preferably 0.1% by mass or more or 0.2% by mass or more, particularly preferably 0.3% by mass or more.

[0177] When the resin composition of the present invention contains (e) a curing accelerator, the content of (e) the curing accelerator in the resin composition may be determined depending on the properties required of the resin composition, but is preferably 5% by mass or less, more preferably 1% by mass or less, even more preferably 0.5% by mass or less, particularly preferably 0.1% by mass or less or 0.08% by mass or less, based on 100% by mass of the non-volatile components in the resin composition. The lower limit is preferably 0.0001% by mass or more, more preferably 0.001% by mass or more, even more preferably 0.01% by mass or more, particularly preferably 0.02% by mass or more, 0.04% by mass or more, or 0.06% by mass or more.

[0178] When the resin composition of the present invention contains (e) a curing accelerator, the mass ratio of (e) the curing accelerator to (a) component [(e) component / (a) component] is, from the viewpoint of significantly achieving the effects of the present invention, preferably 0.0001 or more, more preferably 0.001 or more, even more preferably 0.005 or more, and particularly preferably 0.01 or more or 0.015 or more. The upper limit is preferably 0.5 or less or 0.1 or less, more preferably 0.05 or less or 0.03 or less, and even more preferably 0.02 or less.

[0179] When the resin composition of the present invention contains a (b) polymerization initiator and an (e) curing accelerator, the mass ratio of the (e) curing accelerator to the (b) polymerization initiator [component (e) / component (b)] is, from the viewpoint of significantly achieving the effects of the present invention, preferably at least 0.05, at least 0.1, or at least 0.3, more preferably at least 0.5 or at least 0.8, and even more preferably at least 1 or at least 1.2. The upper limit is preferably at most 50, at most 20, or at most 10, more preferably at most 8 or at most 5, even more preferably at most 4 or at most 3, and particularly preferably at most 2, at most 1.5, or at most 1.3.

[0180] When the resin composition of the present invention contains (c) other curable resins and (e) curing accelerators, the mass ratio of the (e) curing accelerator to the (c) other curable resins [component (e) / component (c)] is, from the viewpoint of significantly achieving the effects of the present invention, preferably 0.0001 or more, more preferably 0.001 or more, even more preferably 0.005 or more, and particularly preferably 0.01 or more. The upper limit is preferably 0.5 or less or 0.1 or less, more preferably 0.05 or less or 0.03 or less, and even more preferably 0.02 or less or 0.015 or less.

[0181] When the resin composition of the present invention contains a (d) curing agent and a (e) curing accelerator, the mass ratio of the (e) curing accelerator to the (d) curing agent [(e) component / (d) component] is, from the viewpoint of significantly achieving the effects of the present invention, preferably 0.0001 or more, more preferably 0.001 or more, even more preferably 0.005 or more, and particularly preferably 0.01 or more. The upper limit is preferably 0.5 or less or 0.1 or less, more preferably 0.05 or less or 0.03 or less, and even more preferably 0.02 or less or 0.015 or less.

[0182] <(f) Thermoplastic resin> The resin composition of the present invention may further contain (f) a thermoplastic resin as an optional component.

[0183] Examples of thermoplastic resins include phenoxy resins, polyvinyl acetal resins, polyolefin resins, polybutadiene resins, polyimide resins, polyamideimide resins, polyetherimide resins, polysulfone resins, polyethersulfone resins, polyphenylene ether resins, polycarbonate resins, polyetheretherketone resins, and polyester resins. Among these, phenoxy resins are preferred from the viewpoint of achieving significant effects of the present invention. The phenoxy resins described here are components other than those corresponding to epoxy resins. Furthermore, the thermoplastic resins may be used alone or in combination of two or more.

[0184] Examples of phenoxy resins include phenoxy resins having one or more skeletons selected from the group consisting of bisphenol A, bisphenol F, bisphenol S, bisphenolacetophenone, novolac, biphenyl, fluorene, dicyclopentadiene, norbornene, naphthalene, anthracene, adamantane, terpene, and trimethylcyclohexane. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group.

[0185] Specific examples of phenoxy resins include "1256" and "4250" manufactured by Mitsubishi Chemical Corporation (both of which are phenoxy resins containing a bisphenol A skeleton); "YX8100" manufactured by Mitsubishi Chemical Corporation (phenoxy resin containing a bisphenol S skeleton); "YX6954" manufactured by Mitsubishi Chemical Corporation (phenoxy resin containing a bisphenol acetophenone skeleton); "FX280" and "FX293" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YL6954BH30," "YL7500BH30," "YX6954BH30," "YX7553," "YX7553BH30," "YL7769BH30," "YL6794," "YL7213," "YL7290," "YL7482," and "YL7891BH30" manufactured by Mitsubishi Chemical Corporation.

[0186] Examples of polyvinyl acetal resins include polyvinyl formal resins and polyvinyl butyral resins, with polyvinyl butyral resins being preferred. Specific examples of polyvinyl acetal resins include S-LEC BH series, BX series (e.g., BX-5Z), KS series (e.g., KS-1), BL series, and BM series manufactured by Sekisui Chemical Co., Ltd.

[0187] Examples of polyolefin resins include ethylene copolymer resins such as low-density polyethylene, very low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl acrylate copolymer; and polyolefin polymers such as polypropylene and ethylene-propylene block copolymer.

[0188] Specific examples of polyimide resins include "Rikacoat SN20" and "Rikacoat PN20" manufactured by New Japan Chemical Co., Ltd.

[0189] Specific examples of polyamide-imide resins include "Vylomax HR11NN" and "Vylomax HR16NN" manufactured by Toyobo Co., Ltd. Specific examples of polyamide-imide resins also include modified polyamide-imides such as "KS9100" and "KS9300" (polysiloxane skeleton-containing polyamide-imides) manufactured by Resonac Corporation.

[0190] A specific example of the polyethersulfone resin is "PES5003P" manufactured by Sumitomo Chemical Co., Ltd.

[0191] Specific examples of polysulfone resins include polysulfones "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

[0192] Examples of polyester resins include polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polybutylene naphthalate resin, polytrimethylene terephthalate resin, polytrimethylene naphthalate resin, and polycyclohexane dimethyl terephthalate resin.

[0193] From the viewpoint of significantly obtaining the effects of the present invention, the weight average molecular weight (Mw) of the thermoplastic resin is preferably 8,000 or more, more preferably 10,000 or more, particularly preferably 20,000 or more, and preferably 70,000 or less, more preferably 60,000 or less, particularly preferably 50,000 or less.

[0194] When the resin composition of the present invention contains a thermoplastic resin (f), the content of the thermoplastic resin (f) in the resin composition may be determined depending on the properties required of the resin composition, but is preferably 0.1% by mass or more, 1% by mass or more, or 2% by mass or more, more preferably 3% by mass or more, or 4% by mass or more, and even more preferably 5% by mass or more, or 6% by mass or more, based on 100% by mass of the resin components in the resin composition. The upper limit is preferably 30% by mass or less, or 20% by mass or less, more preferably 15% by mass or less, or 10% by mass or less, and even more preferably 9% by mass or less, or 8% by mass or less.

[0195] When the resin composition of the present invention contains a thermoplastic resin (f), the content of the thermoplastic resin (f) in the resin composition may be determined depending on the properties required of the resin composition, but is preferably 0.01 mass% or more, 0.1 mass% or more, or 0.2 mass% or more, more preferably 0.5 mass% or more, or 0.8 mass% or more, and even more preferably 1 mass% or more, or 1.2 mass% or more, based on 100 mass% of the nonvolatile components in the resin composition. The upper limit is preferably 10 mass% or less, or 8 mass% or less, more preferably 6 mass% or less, 5 mass% or less, or 4 mass% or less, and even more preferably 3 mass% or less, 2 mass% or less, or 1.5 mass% or less.

[0196] When the resin composition of the present invention contains the thermoplastic resin (f), the mass ratio of the thermoplastic resin (f) to the component (a) [component (f) / component (a)] is, from the viewpoint of significantly achieving the effects of the present invention, preferably 0.001 or more, more preferably 0.01 or more or 0.02 or more, even more preferably 0.05 or more or 0.08 or more, and particularly preferably 0.1 or more, 0.15 or more, 0.2 or more, or 0.25 or more. The upper limit is preferably 10 or less, more preferably 5 or less, 2 or less, or 1 or less, and even more preferably 0.5 or less, 0.4 or less, or 0.35 or less.

[0197] When the resin composition of the present invention contains (b) a polymerization initiator and (f) a thermoplastic resin, the mass ratio of the (f) thermoplastic resin to the (b) polymerization initiator [(f) component / (b) component], from the viewpoint of significantly obtaining the effects of the present invention, is preferably 1 or more, more preferably 2 or more or 5 or more, even more preferably 10 or more or 15 or more, and particularly preferably 18 or more, 20 or more, or 22 or more. The upper limit is preferably 1,000 or less, more preferably 500 or less, 200 or less, or 100 or less, even more preferably 50 or less, 40 or less, or 30 or less, and particularly preferably 25 or less.

[0198] When the resin composition of the present invention contains (c) other curable resin and (f) thermoplastic resin, the mass ratio of the (f) thermoplastic resin to the (c) other curable resin [(f) component / (c) component] is, from the viewpoint of significantly obtaining the effects of the present invention, preferably 0.001 or more, more preferably 0.01 or more or 0.02 or more, even more preferably 0.05 or more or 0.08 or more, and particularly preferably 0.1 or more, 0.15 or more, or 0.18 or more. The upper limit is preferably 10 or less, more preferably 5 or less, 2 or less, or 1 or less, and even more preferably 0.5 or less, 0.4 or less, 0.3 or less, or 0.25 or less.

[0199] When the resin composition of the present invention contains a (d) curing agent and a (f) thermoplastic resin, the mass ratio of the (f) thermoplastic resin to the (d) curing agent [(f) component / (d) component] is, from the viewpoint of significantly achieving the effects of the present invention, preferably 0.001 or more, more preferably 0.01 or more or 0.02 or more, even more preferably 0.05 or more or 0.08 or more, and particularly preferably 0.1 or more, 0.15 or more, or 0.18 or more. The upper limit is preferably 10 or less, more preferably 5 or less, 2 or less, or 1 or less, and even more preferably 0.5 or less, 0.4 or less, 0.3 or less, or 0.25 or less.

[0200] When the resin composition of the present invention contains an (e) curing accelerator and a (f) thermoplastic resin, the mass ratio of the (f) thermoplastic resin to the (e) curing accelerator [component (f) / component (e)] is, from the viewpoint of significantly obtaining the effects of the present invention, preferably at least 1, more preferably at least 2 or 5, even more preferably at least 10 or 15, and particularly preferably at least 16. The upper limit is preferably 1,000 or less, more preferably 500 or less, 200 or less, or 100 or less, even more preferably 50 or less, 40 or less, or 30 or less, and particularly preferably 25 or less, or 20 or less.

[0201] <(g) Inorganic filler> The resin composition of the present invention may further contain (g) an inorganic filler as an optional component, which can further reduce the linear thermal expansion coefficient and the dielectric loss tangent.

[0202] (g) Inorganic compounds can be used as the inorganic filler material. Examples of (g) inorganic fillers include silica, alumina, aluminosilicate, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, 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 titanate zirconate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica is preferred. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Furthermore, spherical silica is preferred. (g) The inorganic filler may be used alone or in combination of two or more kinds in any ratio.

[0203] (g) Examples of commercially available inorganic fillers include "SP60-05" and "SP507-05" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YC100C", "YA050C", "YA050C-MJE", "YA010C", "SC2500SQ", "SO-C4", "SO-C2", "SO-C1", "SC2300-SVJ", "SC2050-SXF", and "180nmSX-C1" manufactured by Admatechs Co., Ltd.; "UFP-30", "DAW-03", and "FB-105FD" manufactured by Denka Co., Ltd.; "Silfil NSS-3N", "Silfil NSS-4N", and "Silfil NSS-5N" manufactured by Tokuyama Corporation; and "CellSpheres" and "MGH-005" manufactured by Taiheiyo Cement Corporation.

[0204] The average particle size of the (g) inorganic filler is preferably 10 μm or less, more preferably 5 μm or less, even more preferably 2 μm or less, even more preferably 1 μm or less, and particularly preferably 0.7 μm or less or 0.5 μm or less, from the viewpoint of achieving low surface roughness of the cured product (insulating layer) and facilitating the formation of fine wiring. The lower limit of the average particle size of the (g) inorganic filler is not particularly limited, but is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.1 μm or more, and particularly preferably 0.15 μm or more or 0.2 μm or more. The average particle size of the (g) inorganic filler can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, the particle size distribution of the inorganic filler is prepared on a volume basis using a laser diffraction / scattering particle size distribution analyzer, and the median diameter is used as the average particle size. A measurement sample can be prepared by weighing 100 mg of inorganic filler and 10 g of methyl ethyl ketone into a vial and dispersing it ultrasonically for 10 minutes. The wavelength of the light source used in the laser diffraction particle size distribution analyzer can be blue or red, and the measurement can be performed using a flow cell system. Examples of the laser diffraction particle size distribution analyzer include the "LA-960" manufactured by Horiba, Ltd.

[0205] (g) The specific surface area of ​​the inorganic filler is not particularly limited, but is preferably 0.1 m 2 / g or more, more preferably 0.5m 2 / g or more, more preferably 1m 2 / g or more or 3m 2 The upper limit of the specific surface area of ​​the inorganic filler (g) is not particularly limited, but is preferably 100 m 2 / g or less, more preferably 70m 2 / g or less, more preferably 50m 2 / g or less, particularly preferably 40m 2 / g or less or 30m 2 The specific surface area of ​​the inorganic filler can be calculated according to the BET method by adsorbing nitrogen gas onto the surface of a sample using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech Co., Ltd.) and then using the BET multipoint method.

[0206] The (g) inorganic filler is preferably surface-treated with a surface treatment agent. The surface treatment can improve the moisture resistance and dispersibility of the (g) inorganic filler. Examples of the surface treatment agent include vinyl-based silane coupling agents such as vinyltrimethoxysilane and vinyltriethoxysilane; epoxy-based silane coupling agents such as 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane; and styryl-based silane coupling agents such as p-styryltrimethoxysilane. coupling agents; methacrylic silane coupling agents such as 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane; acrylic silane coupling agents such as 3-acryloxypropyltrimethoxysilane; N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane; Amino-based silane coupling agents such as propyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-8-aminooctyltrimethoxysilane, and N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane; isocyanurate-based silane coupling agents such as tris(trimethoxysilylpropyl)isocyanurate; ureido-based silane coupling agents such as ureidopropyltrialkoxysilane; mercapto-based silane coupling agents such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane; isocyanate-based silane coupling agents such as 3-isocyanatepropyltriethoxysilane; acid anhydride-based silane coupling agents such as 3-trimethoxysilylpropylsuccinic anhydride; sulfide silane-based coupling agents such as bis(triethoxysilylpropyl)tetrasulfide;Examples of suitable surface treatment agents include silane coupling agents such as methyltrimethoxysilane and phenyltrimethoxysilane, non-silane coupling alkoxysilane compounds such as methyltrimethoxysilane and phenyltrimethoxysilane, organosilazane compounds, and titanate-based coupling agents. The surface treatment agents may be used alone or in combination of two or more in any ratio. In one embodiment, the inorganic filler (g) is preferably surface-treated with an amino-based silane coupling agent, and more preferably surface-treated with N-phenyl-3-aminopropyltrimethoxysilane.

[0207] When the resin composition of the present invention contains (g) an inorganic filler, the content of (g) the inorganic filler, relative to the nonvolatile components of the resin composition taken as 100% by mass, is preferably 5% by mass or more or 10% by mass or more, more preferably 20% by mass or more, 30% by mass or more, or 40% by mass or more, even more preferably 50% by mass or more, 60% by mass or more, 70% by mass or more, or 80% by mass or more, from the viewpoint of further reducing the dielectric loss tangent of the cured product. The upper limit is preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 88% by mass or less, and particularly preferably 86% by mass or less, 85% by mass or less, or 84% by mass or less.

[0208] When the resin composition of the present invention contains (g) an inorganic filler, the mass ratio of (g) the inorganic filler to (a) component [(g) component / (a) component] is, from the viewpoint of significantly obtaining the effects of the present invention, preferably at least 1, more preferably at least 2 or 5, even more preferably at least 10 or 15, and particularly preferably at least 16. The upper limit is preferably 1,000 or less, more preferably 500 or less, 200 or less, or 100 or less, even more preferably 50 or less, 40 or less, or 30 or less, and particularly preferably 25 or less, or 22 or less.

[0209] When the resin composition of the present invention contains (b) a polymerization initiator and (g) an inorganic filler, from the viewpoint of significantly achieving the effects of the present invention, the mass ratio of the inorganic filler (g) to the polymerization initiator (b) [(g) component / (b) component] is preferably at least 10, 100, or 200, more preferably at least 300 or 500, even more preferably at least 800 or 1000, and particularly preferably at least 1200 or 1400. The upper limit of the mass ratio [(g) component / (b) component] is preferably at most 100,000, 50,000, or 20,000, more preferably at most 10,000, 8,000, or 6,000, and even more preferably at most 4,000, 3,000, 2,500, 2,000, or 1,600.

[0210] When the resin composition of the present invention contains (c) other curable resins and (g) inorganic fillers, the mass ratio of the (g) inorganic filler to the (c) other curable resins [(g) component / (c) component], from the viewpoint of significantly obtaining the effects of the present invention, is preferably 1 or more, more preferably 2 or more or 5 or more, even more preferably 6 or more or 8 or more, and particularly preferably 10 or more or 12 or more. The upper limit is preferably 1000 or less, more preferably 500 or less, 200 or less or 100 or less, even more preferably 50 or less, 40 or less or 30 or less, and particularly preferably 25 or less, 20 or less or 15 or less.

[0211] When the resin composition of the present invention contains a (d) curing agent and a (g) inorganic filler, the mass ratio of the (g) inorganic filler to the (d) curing agent [(g) component / (d) component], from the viewpoint of significantly obtaining the effects of the present invention, is preferably 1 or more, more preferably 2 or more or 5 or more, even more preferably 6 or more or 8 or more, and particularly preferably 10 or more or 12 or more. The upper limit is preferably 1,000 or less, more preferably 500 or less, 200 or less or 100 or less, even more preferably 50 or less, 40 or less or 30 or less, and particularly preferably 25 or less, 20 or less or 15 or less.

[0212] When the resin composition of the present invention contains an (e) curing accelerator and a (g) inorganic filler, from the viewpoint of significantly achieving the effects of the present invention, the mass ratio of the (g) inorganic filler to the (e) curing accelerator [(g) component / (e) component] is preferably at least 10, 100 or 200, more preferably at least 300 or 500, even more preferably at least 800 or 1000, and particularly preferably at least 1100. The upper limit of the mass ratio [(g) component / (e) component] is preferably at most 100,000, 50,000 or 20,000, more preferably at most 10,000, 8,000 or 6,000, even more preferably at most 4,000 or 3,000, and particularly preferably at most 2,500, 2,000 or 1,500.

[0213] When the resin composition of the present invention contains a (f) thermoplastic resin and a (g) inorganic filler, from the viewpoint of significantly achieving the effects of the present invention, the mass ratio of the (g) inorganic filler to the (f) thermoplastic resin [(g) component / (f) component] is preferably 0.1 or more, 0.5 or more, 1 or more, or 2 or more, more preferably 5 or more, or 10 or more, even more preferably 20 or more, or 30 or more, and particularly preferably 40 or more, 50 or more, or 60 or more. The upper limit of the mass ratio [(g) component / (f) component] is preferably 1,000 or less, 500 or less, or 200 or less, more preferably 180 or less, 160 or less, or 150 or less, even more preferably 140 or less, 120 or less, or 100 or less, and particularly preferably 80 or less.

[0214] <(h) Organic solvent> The resin composition of the present invention may further contain (h) an organic solvent as an optional component. By adding (h) an organic solvent to the resin composition, a resin composition with an appropriate viscosity can be obtained. (h) The organic solvent may be used alone or in combination of two or more.

[0215] Examples of (h) organic solvents include organic solvents composed of atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, phosphorus atoms, sulfur atoms, halogen atoms, and hydrogen atoms. From the viewpoint of safety, (h) organic solvents are preferably organic solvents composed of atoms selected from carbon atoms, oxygen atoms, and hydrogen atoms, and more preferably organic solvents composed of carbon atoms, oxygen atoms, and hydrogen atoms.

[0216] Examples of (h) organic solvents include glycol-based organic solvents, glycol ether-based organic solvents, glycol ether ester-based organic solvents, ketone-based organic solvents, ester-based organic solvents, ether-based organic solvents, alcohol-based organic solvents, aliphatic hydrocarbon-based organic solvents, aromatic organic solvents, nitrogen-based organic solvents, sulfur-based organic solvents, and halogen-based organic solvents. Examples of nitrogen-based organic solvents include amide-based organic solvents, urea-based organic solvents, and nitrile-based organic solvents. From the viewpoint of safety, (h) organic solvents are preferably ester-based organic solvents, ketone-based organic solvents, glycol-based organic solvents, glycol ether-based organic solvents, or glycol ether ester-based organic solvents, more preferably ester-based organic solvents, glycol ether ester-based organic solvents, or ketone-based organic solvents, and particularly preferably glycol ether ester-based organic solvents or ketone-based organic solvents.

[0217] Examples of glycol-based organic solvents include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, and trimethylene glycol.

[0218] Examples of glycol ether organic solvents include cellosolves such as ethylene glycol monomethyl ether (also known as methyl cellosolve), ethylene glycol monoethyl ether (also known as cellosolve), ethylene glycol monopropyl ether (also known as propyl cellosolve), ethylene glycol monobutyl ether (also known as butyl cellosolve), ethylene glycol monoisobutyl ether (also known as isobutyl cellosolve), ethylene glycol mono-tert-butyl ether (also known as tert-butyl cellosolve), and ethylene glycol monohexyl ether; diethylene glycol monomethyl ether (also known as methyl carbitol), diethylene glycol monoethyl ether ( carbitols such as diethylene glycol monopropyl ether (also known as propyl carbitol) and diethylene glycol monobutyl ether (DB) (also known as butyl carbitol); propylene glycol ethers such as propylene glycol monomethyl ether (PGM), propylene glycol monoethyl ether, propylene glycol monopropyl ether and propylene glycol monobutyl ether; and dipropylene glycol ethers such as dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether and dipropylene glycol monobutyl ether.

[0219] Examples of glycol ether ester organic solvents include cellosolve esters such as ethylene glycol monomethyl ether acetate (also known as methyl cellosolve acetate), ethylene glycol monoethyl ether acetate (also known as cellosolve acetate), and ethylene glycol monobutyl ether acetate (also known as butyl cellosolve acetate); carbitol esters such as diethylene glycol monoethyl ether acetate (EDGAc) (also known as carbitol acetate) and diethylene glycol monobutyl ether acetate (also known as butyl carbitol acetate); propylene glycol ether esters such as propylene glycol monomethyl ether acetate (PGMEAc) and propylene glycol monoethyl ether acetate; and dipropylene glycol ether esters such as dipropylene glycol monomethyl ether acetate, with carbitol esters being preferred and more preferred than diethylene glycol monoethyl ether acetate.

[0220] Examples of ketone-based organic solvents include aliphatic acyclic ketones such as acetone, methyl ethyl ketone (MEK), diethyl ketone, 2-pentanone, methyl isobutyl ketone, 2-hexanone, 2-heptanone (MAK), and diisobutyl ketone; aliphatic cyclic ketones such as cyclopentanone, cyclohexanone (ANONE), and 2-methylcyclohexanone; and aromatic ketones such as acetophenone. Methyl ethyl ketone (MEK) or cyclohexanone is preferred, and cyclohexanone is more preferred. The lower limit of the number of carbon atoms in the ketone-based organic solvent is preferably 2 or more, more preferably 3 or more, and even more preferably 4 or more. The upper limit of the number of carbon atoms in the ketone-based organic solvent is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less.

[0221] Ester-based organic solvents are organic solvents having an ester structure that do not fall under the category of glycol ether ester-based organic solvents. Examples include fatty acid alkyl esters such as methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, tert-butyl acetate, n-pentyl acetate, isopentyl acetate, ethyl propionate, propyl propionate, and isopropyl propionate; hydroxy acid alkyl esters such as methyl lactate, ethyl lactate, and butyl lactate; keto acid alkyl esters such as methyl acetoacetate and ethyl acetoacetate; lactones such as γ-butyrolactone and α-acetyl-γ-butyrolactone; and aromatic esters such as methyl benzoate and ethyl benzoate. Lactones are preferred as ester-based organic solvents. Furthermore, the number of carbon atoms in the ester-based organic solvent is preferably 3 to 9.

[0222] The ether-based organic solvent is an organic solvent having an ether structure that does not fall under the category of glycol ether-based organic solvents or glycol ether ester-based organic solvents, and examples thereof include aliphatic acyclic ethers such as dimethyl ether, diethyl ether, methyl ethyl ether, diisopropyl ether, dibutyl ether, methyl tert-butyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and triethylene glycol dimethyl ether; aliphatic cyclic ethers such as tetrahydrofuran, 1,4-dioxane, and 1,3-dioxolane; and aromatic ethers such as anisole and phenetole. The number of carbon atoms in the ether-based organic solvent is preferably 2 to 9.

[0223] Alcohol-based organic solvents are organic solvents having an alcohol structure that does not fall under the category of glycol-based organic solvents and glycol ether-based organic solvents, and examples thereof include aliphatic acyclic alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, n-pentyl alcohol, isopentyl alcohol, sec-pentyl alcohol, tert-pentyl alcohol, neopentyl alcohol, n-hexyl alcohol, n-heptyl alcohol, isoheptyl alcohol, n-octyl alcohol, and 2-ethylhexyl alcohol; aliphatic cyclic alcohols such as cyclohexanol; and aromatic alcohols such as benzyl alcohol and phenethyl alcohol.

[0224] Examples of aliphatic hydrocarbon organic solvents include n-pentane, n-hexane, 2-methylpentane (also known as isohexane), n-heptane, n-octane, cyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane, decalin, etc. The aliphatic hydrocarbon organic solvent preferably has 5 to 10 carbon atoms.

[0225] Examples of aromatic organic solvents include C benzene, toluene, o-xylene, m-xylene, p-xylene, and ethylbenzene. 6-8 Aromatic hydrocarbons: C9 aromatic hydrocarbons such as 1,2,3-trimethylbenzene, 1,3,5-trimethylbenzene (also known as mesitylene), 1,2,4-trimethylbenzene, 4-ethyltoluene, 3-ethyltoluene, and 2-ethyltoluene; C1 aromatic hydrocarbons such as 1,2-diethylbenzene, 1,3-diethylbenzene, 1,4-diethylbenzene, 3-ethyl-o-xylene, 4-ethyl-o-xylene, 2-ethyl-p-xylene, 1,2,3,5-tetramethylbenzene, and tetralin. 10 Examples include aromatic hydrocarbons and aromatic heterocyclic compounds such as pyridine, furan, thiophene, etc. The aromatic organic solvent preferably has 6 to 10 carbon atoms.

[0226] Examples of amide-based organic solvents include aliphatic acyclic amides such as N,N-dimethylacetamide and N,N-dimethylformamide, lactams such as N-methyl-2-pyrrolidone and N-cyclohexyl-2-pyrrolidone, and phosphoric acid amides such as hexamethylphosphoramide. The number of carbon atoms in the amide-based organic solvent is preferably 2 to 10.

[0227] Examples of urea-based organic solvents include tetramethylurea and 1,3-dimethyl-2-imidazolinone.

[0228] Examples of the nitrile organic solvent include acetonitrile, propionitrile, benzonitrile, etc. The nitrile organic solvent preferably has 2 to 10 carbon atoms.

[0229] An example of the sulfur-based organic solvent is dimethyl sulfoxide.

[0230] Examples of halogen-based organic solvents include chloroform, methylene chloride, carbon tetrachloride, 1,2-dichloroethane, etc. The halogen-based organic solvent preferably has 1 to 10 carbon atoms.

[0231] Among these, γ-butyrolactone, methyl ethyl ketone (MEK), cyclopentanone, cyclohexanone, propylene glycol, diethylene glycol monoethyl ether acetate, or propylene glycol monomethyl ether acetate is preferred, methyl ethyl ketone (MEK), cyclohexanone, diethylene glycol monoethyl ether acetate, or γ-butyrolactone is more preferred, methyl ethyl ketone (MEK), cyclohexanone, or diethylene glycol monoethyl ether acetate is even more preferred, and cyclohexanone is particularly preferred.

[0232] When the resin composition of the present invention contains (h) an organic solvent, the content of (h) the organic solvent in the resin composition may be determined depending on the properties and viscosity required of the resin composition, but when all components in the resin composition are taken as 100% by mass, it may be, for example, 70% by mass or less, 60% by mass or less, 50% by mass or less, 20% by mass or less, 16% by mass or less, etc. The lower limit may be 0.1% by mass or more, 1% by mass or more, 10% by mass or more, etc.

[0233] When the resin composition of the present invention contains an organic solvent (h), the mass ratio of the organic solvent (h) to the component (a) [component (h) / component (a)], from the viewpoint of significantly achieving the effects of the present invention, is preferably 0.1 or more or 0.3 or more, more preferably 0.5 or more or 0.8 or more, even more preferably 1 or more, 1.5 or more or 2 or more, particularly preferably 2.5 or more, 3 or more, 3.5 or more, or 4 or more. The upper limit is preferably 50 or less, 20 or less, or 10 or less, more preferably 8 or less or 6 or less, and even more preferably 5 or less or 4.5 or less.

[0234] The resin composition of the present invention may further contain (i) other additives. Examples of such additives include organic fillers such as rubber particles; organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt compounds; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; leveling agents such as silicone-based leveling agents and acrylic polymer-based leveling agents; thickeners such as bentone and montmorillonite; antifoaming agents such as silicone-based antifoaming agents, acrylic-based antifoaming agents, fluorine-based antifoaming agents, and vinyl resin-based antifoaming agents; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; adhesion improvers such as urea silane; triazole-based adhesion promoters, tetrazole-based adhesion promoters, triazine-based adhesion promoters, and the like. Examples of additives include adhesion promoters such as phenol-based adhesion promoters; antioxidants such as hindered phenol-based antioxidants; fluorescent brighteners such as stilbene derivatives; surfactants such as fluorine-based surfactants and silicone-based surfactants; flame retardants such as phosphorus-based flame retardants (e.g., phosphate ester compounds, phosphazene compounds, phosphinic acid compounds, and red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (e.g., antimony trioxide); dispersants such as phosphate ester-based dispersants, polyoxyalkylene-based dispersants, acetylene-based dispersants, silicone-based dispersants, anionic dispersants, and cationic dispersants; and stabilizers such as borate-based stabilizers, titanate-based stabilizers, aluminate-based stabilizers, zirconate-based stabilizers, isocyanate-based stabilizers, carboxylic acid-based stabilizers, and carboxylic anhydride-based stabilizers. The content of such additives may be determined depending on the properties required of the resin composition. Furthermore, the components (a) to (h) may have the functions of an organic filler, an organometallic compound, a colorant, a polymerization inhibitor, a thickener, an antifoaming agent, an ultraviolet absorber, an adhesion improver, an adhesion imparting agent, an antioxidant, a fluorescent brightener, a flame retardant, a dispersant, a stabilizer, etc. In such cases, such components are considered to be components (a) to (h) rather than component (i).

[0235] The resin composition of the present invention can be prepared by appropriately mixing the necessary components among the above components (a) to (i), and kneading or mixing them as needed using kneading means such as a triple roll mill, ball mill, bead mill, or sand mill, or stirring means such as a super mixer or planetary mixer.

[0236] When a resin diluted with a solvent is used as a component of the resin composition of the present invention, the solid resin obtained by removing the solvent may be used, or the resin diluted with the solvent may be used as is, and the solvent portion may be used as (h) organic solvent.

[0237] <Physical properties and applications of resin compositions> In one embodiment, the cured product of the resin composition of the present invention is characterized by a low dielectric constant (Dk). For example, when measured at 5.8 GHz and 23°C as described in the "Dielectric Properties" section below, the dielectric constant (Dk) of the cured product of the resin composition of the present invention is preferably 3.5 or less, 3.4 or less, 3.3 or less, 3.2 or less, 3.1 or less, 3.0 or less, or 2.9 or less. The lower limit is not particularly limited, but may be 0.1 or more, 1.0 or more, etc.

[0238] In one embodiment, the cured product of the resin composition of the present invention is characterized by a low dielectric dissipation factor (Df). For example, when measured at 5.8 GHz and 23°C as described in the "Dielectric Properties" section below, the dielectric dissipation factor (Df) of the cured product of the resin composition of the present invention may be preferably 0.010 or less, 0.008 or less, 0.006 or less, 0.005 or less, 0.004 or less, 0.0035 or less, 0.0034 or less, 0.0032 or less, 0.003 or less, 0.0028 or less, 0.0027 or less, or 0.0026 or less. The lower limit is not particularly limited, but may be 0.0001 or more, 0.001 or more, etc.

[0239] In one embodiment, a cured product of the resin composition of the present invention is characterized by high heat resistance. For example, as described in the "Heat Resistance" section below, when measured using a dynamic viscoelasticity measuring device under measurement conditions of a load of 200 mN and a heating rate of 2°C / min, the glass transition temperature (Tg) may be preferably 180°C or higher, 190°C or higher, 200°C or higher, 210°C or higher, 220°C or higher, or 230°C or higher. The upper limit is not particularly limited, but may be 400°C or lower, 300°C or lower, etc.

[0240] In one embodiment, the cured product of the resin composition of the present invention is characterized by excellent smear removability. For example, as described in the "Smear Removability" section below, when a via hole is formed and the periphery of the bottom of the via hole (via bottom) is observed with a scanning electron microscope (SEM), the maximum smear length can be less than 5 mm.

[0241] In one embodiment, a cured product of the resin composition of the present invention exhibits the property of suppressing haloing. For example, as described in the "Haloing" section below, when a via hole is formed and its cross section is observed using a FIB-SEM composite instrument, the haloing ratio Hb can be 0.5 or less.

[0242] As described above, the resin composition of the present invention can produce a cured product exhibiting excellent dielectric properties and heat resistance, thereby achieving the low transmission loss and heat resistance required for 5G applications. Therefore, the resin composition of the present invention can be suitably used as a resin composition for forming an insulating layer of a printed wiring board (resin composition for an insulating layer of a printed wiring board), and more suitably used as a resin composition for forming an interlayer insulating layer of a printed wiring board (resin composition for an interlayer insulating layer of a printed wiring board). The resin composition of the present invention can also be suitably used when the printed wiring board is a circuit board with built-in components. The resin composition of the present invention can also be suitably used as a resin composition for a rewiring formation layer (resin composition for a rewiring formation layer) as an insulating layer for forming a rewiring layer in a semiconductor chip package, i.e., for forming an insulating layer of a rewiring substrate of a semiconductor chip package (insulating layer of a rewiring substrate). In the present invention, printed wiring boards and rewiring substrates are collectively referred to as "circuit boards," and therefore the resin composition of the present invention can be suitably used as an insulating layer for a circuit board.

[0243] The resin composition of the present invention can also be suitably used as a resin composition for encapsulating a semiconductor chip (a resin composition for semiconductor encapsulation) in a semiconductor chip package.

[0244] The resin composition of the present invention can also be used in a wide range of applications requiring a resin composition, such as sheet-like laminate materials such as resin sheets and prepregs, solder resists, underfill materials, die bonding materials, hole filling resins, and component embedding resins.

[0245] [Sheet-type laminated materials (resin sheets, prepregs)] The resin composition of the present invention can be used as it is, but may also be used in the form of a sheet-like laminate material containing the resin composition.

[0246] As the sheet-like laminate material, the following resin sheets and prepregs are preferred.

[0247] In one embodiment, the resin sheet includes a support and a layer of a resin composition (hereinafter simply referred to as a "resin composition layer") provided on the support, and is characterized in that the resin composition layer is formed from the resin composition of the present invention.

[0248] The thickness of the resin composition layer varies depending on the application, and may be appropriately determined depending on the application. For example, from the viewpoint of thinning printed wiring boards and semiconductor chip packages, the thickness of the resin composition layer is preferably 200 μm or less, more preferably 150 μm or less, 120 μm or less, 100 μm or less, 80 μm or less, 60 μm or less, or 50 μm or less. The lower limit of the thickness of the resin composition layer is not particularly limited, but can usually be 1 μm or more, 5 μm or more, etc.

[0249] Examples of the support include a thermoplastic resin film, a metal foil, and a release paper, and a thermoplastic resin film or a metal foil is preferred. Therefore, in a preferred embodiment, the support is a thermoplastic resin film or a metal foil.

[0250] When a thermoplastic resin film is used as the support, examples of the thermoplastic resin include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), acrylics such as polycarbonate (PC) and polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, polyimide, etc. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, with inexpensive polyethylene terephthalate being particularly preferred.

[0251] When a metal foil is used as the support, examples of the metal foil include copper foil and aluminum foil, with copper foil being preferred. The copper foil may be a foil made of a single metal, copper, or an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

[0252] The support may be subjected to a matte treatment, a corona treatment, or an antistatic treatment on the surface that will be bonded to the resin composition layer. Alternatively, a support with a release layer, which has a release layer on the surface that will be bonded to the resin composition layer, may be used. Examples of the release agent used in the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. Commercially available release agents include "SK-1," "AL-5," and "AL-7" manufactured by Lintec Corporation. Alternatively, a commercially available support with a release layer may be used, such as "Lumirror T60" manufactured by Toray Industries, Inc., "Purex" manufactured by Teijin Limited, or "Uni-Peel" manufactured by Unitika Limited, which are PET films having a release layer primarily composed of an alkyd resin-based release agent.

[0253] The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, more preferably 10 μm to 60 μm. When a support with a release layer is used, it is preferable that the thickness of the entire support with a release layer is in the above range.

[0254] When a metal foil is used as the support, a metal foil with a support substrate may be used, which is a thin metal foil with a peelable support substrate attached thereto. In one embodiment, the metal foil with a support substrate includes a support substrate, a release layer provided on the support substrate, and a metal foil provided on the release layer. When a metal foil with a support substrate is used as the support, the resin composition layer is provided on the metal foil.

[0255] In the metal foil with a supporting substrate, the material of the supporting substrate is not particularly limited, but examples thereof include copper foil, aluminum foil, stainless steel foil, titanium foil, and copper alloy foil. When copper foil is used as the supporting substrate, it may be electrolytic copper foil or rolled copper foil. Furthermore, the release layer is not particularly limited as long as it allows the metal foil to be released from the supporting substrate, and examples thereof include an alloy layer of an element selected from the group consisting of chromium (Cr), nickel (Ni), cobalt (Co), iron (Fe), molybdenum (Mo), titanium (Ti), tungsten (W), and phosphorus (P); an organic coating, and the like.

[0256] In the metal foil with a supporting substrate, the material of the metal foil is preferably, for example, copper foil or copper alloy foil.

[0257] In the metal foil with a supporting substrate, the thickness of the supporting substrate is not particularly limited, but is preferably in the range of 10 μm to 150 μm, more preferably in the range of 10 μm to 100 μm. The thickness of the metal foil may be, for example, in the range of 0.1 μm to 10 μm.

[0258] In one embodiment, the resin sheet may further include an optional layer, if necessary. Examples of such optional layers include a protective film provided on the surface of the resin composition layer that is not bonded to the support (i.e., the surface opposite the support). The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. By laminating the protective film, adhesion of dust and the like to the surface of the resin composition layer and scratches can be suppressed.

[0259] The resin sheet can be produced, for example, by preparing a liquid resin composition as is or a resin composition varnish by dissolving the resin composition in an organic solvent, applying this to a support using a die coater or the like, and then drying to form a resin composition layer.

[0260] Examples of the organic solvent include the same organic solvents as those described as components of the resin composition in the section <(h) Organic solvent>. The organic solvents may be used alone or in combination of two or more.

[0261] Drying may be carried out by known methods such as heating or hot air blowing. Drying conditions are not particularly limited, but drying is carried out so that the content of organic solvent in the resin composition layer becomes 10% by mass or less, preferably 5% by mass or less. Although this varies depending on the boiling point of the organic solvent in the resin composition or resin varnish, for example, when a resin composition or resin varnish containing 10% by mass to 60% by mass of organic solvent is used, the resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0262] The resin sheet can be stored in a rolled state. When the resin sheet has a protective film, it can be used by peeling off the protective film.

[0263] In one embodiment, the prepreg is formed by impregnating a sheet-like fiber substrate with the resin composition of the present invention.

[0264] The sheet-like fiber substrate used for the prepreg is not particularly limited, and commonly used prepreg substrates such as glass cloth, aramid nonwoven fabric, and liquid crystal polymer nonwoven fabric can be used. From the viewpoint of thinning printed wiring boards and semiconductor chip packages, the thickness of the sheet-like fiber substrate is preferably 50 μm or less, more preferably 40 μm or less, even more preferably 30 μm or less, and particularly preferably 20 μm or less. There is no particular lower limit to the thickness of the sheet-like fiber substrate. It is usually 10 μm or more.

[0265] The prepreg can be produced by a known method such as a hot melt method or a solvent method.

[0266] The thickness of the prepreg may be in the same range as that of the resin composition layer in the resin sheet described above.

[0267] The sheet-like laminate material of the present invention can be suitably used to form an insulating layer of a printed wiring board (for an insulating layer of a printed wiring board), and more suitably used to form an interlayer insulating layer of a printed wiring board (for an interlayer insulating layer of a printed wiring board). The sheet-like laminate material of the present invention can also be suitably used to form an insulating layer of a rewiring board of a semiconductor chip package (for an insulating layer of a rewiring board). That is, the sheet-like laminate material of the present invention can be suitably used as an insulating layer of a circuit board. The sheet-like laminate material of the present invention can also be suitably used to encapsulate a semiconductor chip (for semiconductor encapsulation).

[0268] [Circuit board] The resin composition of the present invention can be used to form an insulating layer for a circuit board. The present invention also provides such a circuit board, i.e., a circuit board comprising an insulating layer made of a cured product of the resin composition of the present invention.

[0269] <Printed wiring board> In one embodiment, the circuit board of the present invention is a printed wiring board. The printed wiring board of the present invention includes an insulating layer made of a cured product of the resin composition of the present invention.

[0270] The printed wiring board can be produced, for example, by using the above-mentioned resin sheet by a method including the following steps (I) and (II). (I) A step of laminating a resin sheet on an inner layer substrate so that the resin composition layer of the resin sheet is bonded to the inner layer substrate. (II) Step of thermally curing the resin composition layer to form an insulating layer

[0271] In step (I), a resin sheet is laminated on an inner layer substrate so that the resin composition layer of the resin sheet is bonded to the inner layer substrate. The "inner layer substrate" used in step (I) is a member that serves as the substrate of a printed wiring board, and examples thereof include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. The substrate may have a conductor layer on one or both sides, and this conductor layer may be patterned. An inner layer substrate having a conductor layer (circuit) formed on one or both sides of the substrate may be referred to as an "inner layer circuit board." In addition, an intermediate product on which an insulating layer and / or a conductor layer is to be further formed during the production of a printed wiring board is also included in the "inner layer substrate" referred to in the present invention. When the printed wiring board is a circuit board with built-in components, an inner layer substrate with built-in components may be used.

[0272] The inner layer substrate and the resin sheet can be laminated, for example, by thermocompression bonding the resin sheet to the inner layer substrate from the support side. Examples of a member for thermocompression bonding the resin sheet to the inner layer substrate (hereinafter also referred to as a "thermocompression bonding member") include a heated metal plate (such as a SUS end plate) or a metal roll (SUS roll). The thermocompression bonding member may be pressed directly onto the resin sheet, or may be pressed via an elastic material such as heat-resistant rubber so that the resin sheet can sufficiently conform to the surface irregularities of the inner layer substrate.

[0273] The lamination of the inner layer substrate and the resin sheet may be carried out by a vacuum lamination method. In the vacuum lamination method, the thermocompression temperature is preferably in the range of 60°C to 160°C, more preferably 80°C to 140°C, the thermocompression pressure is preferably in the range of 0.098MPa to 1.77MPa, more preferably 0.29MPa to 1.47MPa, and the thermocompression time is preferably in the range of 10 seconds to 400 seconds, more preferably 20 seconds to 300 seconds. The lamination may be carried out under reduced pressure conditions, preferably at a pressure of 26.7hPa or less.

[0274] The lamination can be performed using a commercially available vacuum laminator, such as a vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nikko Materials Co., Ltd., or a batch vacuum pressure laminator.

[0275] After lamination, the laminated resin sheets may be smoothed under normal pressure (atmospheric pressure), for example, by pressing a thermocompression member from the support side. The pressing conditions for the smoothing treatment may be the same as the thermocompression conditions for lamination. The smoothing treatment may be performed using a commercially available laminator. Note that lamination and smoothing treatment may be performed consecutively using the commercially available vacuum laminator.

[0276] The support may be removed between step (I) and step (II), or after step (II). When a metal foil is used as the support, the conductor layer may be formed using the metal foil without peeling off the support. When a metal foil with a supporting substrate is used as the support, the supporting substrate (and the release layer) may be peeled off. Then, the conductor layer can be formed using the metal foil.

[0277] In step (II), the resin composition layer is thermally cured to form an insulating layer made of a cured product of the resin composition. The curing conditions for the resin composition layer are not particularly limited, and conditions typically employed for forming insulating layers for printed wiring boards may be used.

[0278] For example, the thermal curing conditions for the resin composition layer vary depending on the type of resin composition, but in one embodiment, the curing temperature is preferably 120° C. to 250° C., more preferably 150° C. to 240° C., and even more preferably 180° C. to 230° C. The curing time is preferably 5 minutes to 240 minutes, more preferably 10 minutes to 150 minutes, and even more preferably 15 minutes to 120 minutes.

[0279] Before thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature lower than the curing temperature. For example, prior to thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature of 50°C to 120°C, preferably 60°C to 115°C, more preferably 70°C to 110°C 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.

[0280] When manufacturing a printed wiring board, the following steps may be further performed: (III) drilling holes in the insulating layer, (IV) roughening the insulating layer, and (V) forming a conductor layer. These steps (III) to (V) may be performed according to various methods known to those skilled in the art and used in manufacturing printed wiring boards. When the support is removed after step (II), the support may be removed between steps (II) and (III), between steps (III) and (IV), or between steps (IV) and (V). Furthermore, if necessary, the formation of the insulating layer and the conductor layer in steps (I) to (V) may be repeated to form a multilayer wiring board.

[0281] In another embodiment, the printed wiring board of the present invention can be produced using the above-mentioned prepreg. The production method is basically the same as when a resin sheet is used.

[0282] Step (III) is a step of drilling holes in the insulating layer, thereby forming holes such as via holes and through holes in the insulating layer. Step (III) may be performed using, for example, a drill, a laser, plasma, or the like, depending on the composition of the resin composition used to form the insulating layer. The dimensions and shape of the holes may be determined appropriately depending on the design of the printed wiring board.

[0283] Step (IV) is a step of roughening the insulating layer. Usually, in this step (IV), smear removal (desmear) is also performed. The procedure and conditions of the roughening treatment are not particularly limited, and known procedures and conditions commonly used in forming insulating layers for printed wiring boards can be adopted. For example, the insulating layer can be roughened by performing a swelling treatment with a swelling liquid, a roughening treatment with an oxidizing agent, and a neutralization treatment with a neutralizing liquid in this order.

[0284] The swelling liquid used in the roughening treatment is not particularly limited, but examples thereof include alkaline solutions and surfactant solutions, and is preferably an alkaline solution, with sodium hydroxide solution and potassium hydroxide solution being more preferred. Commercially available swelling liquids include "Swelling Dip Securigance P" and "Swelling Dip Securigance SBU" manufactured by Atotech Japan. The swelling treatment using a swelling liquid is not particularly limited, but can be carried out by, for example, immersing the insulating layer in a swelling liquid at 30°C to 90°C for 1 to 20 minutes. To keep the swelling of the resin in the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in a swelling liquid at 40°C to 80°C for 5 to 15 minutes.

[0285] The oxidizing agent used in the roughening treatment is not particularly limited, but examples include alkaline permanganate solutions prepared by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. Roughening treatment using an oxidizing agent such as alkaline permanganate solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP," "Concentrate Compact P," and "Dosing Solution Securigance P" manufactured by Atotech Japan.

[0286] The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution, and examples of commercially available products include "Reduction Solution Securigant P" manufactured by Atotech Japan.

[0287] Treatment with a neutralizing solution can be carried out by immersing the surface that has been roughened with an oxidizing agent in a neutralizing solution at 30° C. to 80° C. for 5 to 30 minutes. From the standpoint of workability, etc., a method in which the object that has been roughened with an oxidizing agent is immersed in a neutralizing solution at 40° C. to 70° C. for 5 to 20 minutes is preferred.

[0288] Step (V) is a step of forming a conductor layer, and the conductor layer is formed on the insulating layer. The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer contains 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 conductor layer may be a single metal layer or an alloy layer. Examples of alloy layers include layers formed from alloys of two or more metals selected from the above group (e.g., nickel-chromium alloys, copper-nickel alloys, and copper-titanium alloys). Among these, from the viewpoints of versatility in forming the conductor layer, cost, ease of patterning, etc., a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy, a copper-nickel alloy, or a copper-titanium alloy is preferred, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy is more preferred, and a single metal layer of copper is even more preferred.

[0289] The conductor layer may have a single layer structure or a multi-layer structure in which two or more single metal layers or alloy layers made of different types of metals or alloys are laminated. When the conductor layer has a multi-layer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc, or titanium, or an alloy layer of a nickel-chromium alloy.

[0290] The thickness of the conductor layer depends on the desired design of the printed wiring board, but is generally 3 μm to 35 μm, preferably 5 μm to 30 μm.

[0291] In one embodiment, the conductor layer may be formed by plating. For example, a conductor layer having a desired wiring pattern can be formed by plating the surface of the insulating layer using a conventionally known technique such as a semi-additive method or a full-additive method. From the viewpoint of ease of production, it is preferable to form the conductor layer by a semi-additive method. An example of forming the conductor layer by a semi-additive method will be described below.

[0292] First, a plating seed layer is formed on the surface of an insulating layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer, exposing 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, unnecessary plating seed layer is removed by etching or the like, thereby forming a conductor layer having the desired wiring pattern.

[0293] In another embodiment, the conductor layer may be formed using a metal foil. When a metal foil is used to form the conductor layer, step (V) is preferably performed between steps (I) and (II). For example, after step (I), the support is removed, and a metal foil is laminated on the exposed surface of the resin composition layer. The resin composition layer and the metal foil may be laminated by a vacuum lamination method. The lamination conditions may be the same as those described for step (I). Next, step (II) is performed to form an insulating layer. Thereafter, a conductor layer having a desired wiring pattern can be formed using the metal foil on the insulating layer by a conventionally known technique such as a subtractive method or a modified semi-additive method.

[0294] The metal foil can be produced by a known method such as an electrolytic method, a rolling method, etc. Examples of commercially available metal foils include "HLP Foil" and "JXUT-III Foil" manufactured by JX Nippon Mining & Smelting Co., Ltd., and "3EC-III Foil" and "TP-III Foil" manufactured by Mitsui Mining & Smelting Co., Ltd.

[0295] Alternatively, when a metal foil or a metal foil with a supporting substrate is used as the support for the resin sheet, the conductor layer may be formed using the metal foil, as described above.

[0296] <Rewiring substrate for semiconductor chip packages> In one embodiment, the circuit board of the present invention is a rewiring substrate for a semiconductor chip package. Hereinafter, a method for manufacturing the semiconductor chip package will be described.

[0297] [Semiconductor chip package] The semiconductor chip package of the present invention includes a sealing layer made of a cured product of the resin composition of the present invention. As described above, the semiconductor chip package of the present invention may also include an insulating layer (rewiring formation layer) of a rewiring substrate made of a cured product of the resin composition of the present invention.

[0298] A semiconductor chip package can be produced, for example, by a method including the following steps (1) to (6) using the resin composition and resin sheet of the present invention. The resin composition and resin sheet of the present invention can be used to form the sealing layer in step (3) or the rewiring formation layer in step (5). An example of forming a sealing layer or a rewiring formation layer using a resin composition or a resin sheet will be shown below. However, techniques for forming sealing layers and rewiring formation layers for semiconductor chip packages are known, and a person skilled in the art can produce a semiconductor package using the resin composition and resin sheet of the present invention according to known techniques. (1) a step of laminating a temporary fixing film on a substrate; (2) a step of temporarily fixing a semiconductor chip on a temporary fixing film; (3) forming an encapsulation layer on the semiconductor chip; (4) peeling the substrate and the temporary fixing film from the semiconductor chip; (5) forming a rewiring formation layer as an insulating layer on the surface of the semiconductor chip from which the base material and the temporary fixing film have been peeled off; and (6) A step of forming a rewiring layer as a conductor layer on the rewiring formation layer.

[0299] <Process (1)> The material used for the substrate is not particularly limited. Examples of the substrate include a silicon wafer, a glass wafer, a glass substrate, a metal substrate such as copper, titanium, stainless steel, or cold-rolled steel sheet (SPCC), a substrate made of glass fiber impregnated with epoxy resin or the like and subjected to a thermosetting treatment (e.g., an FR-4 substrate), and a substrate made of bismaleimide triazine resin (BT resin).

[0300] The material of the temporary fixing film is not particularly limited as long as it can be peeled off from the semiconductor chip in step (4) and can temporarily fix the semiconductor chip. Commercially available products can be used as the temporary fixing film. Examples of commercially available products include Riva Alpha manufactured by Nitto Denko Corporation.

[0301] <Process (2)> The semiconductor chips can be temporarily fixed using known devices such as a flip chip bonder, a die bonder, etc. The layout and number of semiconductor chips to be arranged can be appropriately set depending on the shape and size of the temporary fixing film, the number of semiconductor packages to be produced, etc., and for example, the semiconductor chips can be temporarily fixed by arranging them in a matrix of multiple rows and multiple columns.

[0302] <Process (3)> The resin composition layer of the resin sheet of the present invention is laminated on a semiconductor chip, or the resin composition of the present invention is applied to a semiconductor chip and cured (for example, thermally cured) to form a sealing layer.

[0303] For example, lamination of a semiconductor chip and a resin sheet can be performed by removing the protective film from the resin sheet and then thermocompressing the resin sheet to the semiconductor chip from the support side. Examples of a member for thermocompressing the resin sheet to the semiconductor chip (hereinafter also referred to as a "thermocompression member") include a heated metal plate (such as a SUS plate) or a metal roll (SUS roll). It is preferable to press the thermocompression member not directly onto the resin sheet, but via an elastic material such as heat-resistant rubber, so that the resin sheet can adequately conform to the surface irregularities of the semiconductor chip. The semiconductor chip and resin sheet can also be laminated by a vacuum lamination method, and the lamination conditions and preferred ranges are the same as those described in relation to the method for manufacturing a printed wiring board.

[0304] After lamination, the resin composition is thermally cured to form the sealing layer under the same conditions as those described in relation to the method for producing a printed wiring board.

[0305] The support of the resin sheet may be peeled off after the resin sheet is laminated on the semiconductor chip and thermally cured, or the support may be peeled off before the resin sheet is laminated on the semiconductor chip.

[0306] When forming a sealing layer by applying the resin composition of the present invention, the application conditions are the same as the application conditions when forming the resin composition layer described in relation to the resin sheet of the present invention, and the preferred ranges are also the same.

[0307] <Process (4)> The method for peeling off the substrate and the temporary fixing film can be changed as appropriate depending on the material of the temporary fixing film, etc., and examples include a method in which the temporary fixing film is heated and foamed (or expanded) to peel it off, and a method in which ultraviolet light is irradiated from the substrate side to reduce the adhesive strength of the temporary fixing film and peel it off.

[0308] In the method of heating and foaming (or expanding) the temporary fixing film to peel it off, the heating conditions are usually 100 to 250°C for 1 to 90 seconds or 5 to 15 minutes. In the method of irradiating ultraviolet light from the substrate side to reduce the adhesive strength of the temporary fixing film to peel it off, the irradiation dose of ultraviolet light is usually 10 mJ / cm. 2 ~1000mJ / cm 2 is.

[0309] <Process (5)> The material for forming the rewiring formation layer (insulating layer) is not particularly limited as long as it has insulating properties when the rewiring formation layer (insulating layer) is formed, and from the viewpoint of ease of manufacturing a semiconductor chip package, ultraviolet-curable resins and thermosetting resins are preferred. The rewiring formation layer may be formed using the resin composition or resin sheet of the present invention.

[0310] After forming the redistribution layer, via holes may be formed in the redistribution layer to connect the semiconductor chip to a conductor layer (described later). The via holes may be formed by a known method depending on the material of the redistribution layer.

[0311] <Process (6)> The formation of the conductor layer on the rewiring formation layer may be carried out in the same manner as in step (V) described in relation to the method for producing a printed wiring board. Note that steps (5) and (6) may be repeated to alternately stack (build up) the conductor layer (rewiring layer) and the rewiring formation layer (insulating layer).

[0312] The manufacturing of the semiconductor chip package may further include the steps of (7) forming a solder resist layer on the conductor layer (rewiring layer), (8) forming bumps, and (9) dicing the plurality of semiconductor chip packages into individual semiconductor chip packages. These steps may be performed according to various methods known to those skilled in the art for use in manufacturing semiconductor chip packages.

[0313] By forming an encapsulating layer and a rewiring formation layer using the resin composition and resin sheet of the present invention, which produce a cured product exhibiting excellent dielectric properties, a semiconductor chip package with extremely low transmission loss can be realized, regardless of whether the semiconductor package is a fan-in package or a fan-out package. In one embodiment, the semiconductor chip package of the present invention is a fan-out package. The resin composition and resin sheet of the present invention can be applied to both a fan-out panel level package (FO-PLP) and a fan-out wafer level package (FO-WLP). In one embodiment, the semiconductor package of the present invention is a fan-out panel level package (FOPLP). In another embodiment, the semiconductor package of the present invention is a fan-out wafer level package (FOWLP).

[0314] [Semiconductor Devices] The semiconductor device of the present invention includes a layer made of a cured product of the resin composition of the present invention, and includes the circuit board or semiconductor chip package of the present invention.

[0315] Examples of semiconductor devices include various semiconductor devices used in electrical appliances (for example, computers, mobile phones, digital cameras, and televisions) and vehicles (for example, motorcycles, automobiles, trains, ships, and aircraft). [Example]

[0316] The present invention will be described in more detail below using examples, but the present invention is not limited to these examples. In the following description, unless otherwise specified, "parts" and "%" mean "parts by mass" and "% by mass", respectively.

[0317] Example 1: Synthesis of polyamide-imide resin (1) [ka]

[0318] A 1-liter four-necked round flask equipped with a stirrer, thermometer, condenser, dropping funnel, and Dean-Stark trap was charged with 66.60 g (0.30 mol) of isophorone diisocyanate (reagent), 28.80 g (0.15 mol) of trimellitic anhydride (reagent), 0.50 g of 1,4-diazabicyclo[2.2.2]octane (reagent) as a catalyst, and 100 g of diethylene glycol monoethyl ether acetate as a reaction solvent, in a composition ratio such that the average n value in the theoretical structural formula was 1.0 and the maleimide group equivalent was 464 g / eq., and the mixture was stirred at 30°C. The mixture was then heated to 120°C and reacted at 120°C for 2 hours. The mixture was then heated to 150°C and reacted at 150°C for 8 hours, after which it was cooled to 30°C.

[0319] 56.70 g (0.30 mol) of N-(4-hydroxyphenyl)maleimide (reagent) was added to the reaction solution and dissolved at 30° C. The temperature was then raised to 60° C., and the reaction was carried out at 60° C. for 48 hours. The solution was microfiltered to remove impurities, and then diluted with diethylene glycol monoethyl ether acetate to obtain 250 g of a brown solution with a solid content of 50%.

[0320] Measurements were carried out by gel permeation chromatography (GPC) and infrared spectroscopy (IR) under the following GPC measurement conditions and IR measurement conditions, and the resin was confirmed to be polyamideimide resin (1) (measured molecular weight Mn=930).

[0321] (GPC measurement conditions) Measuring device: Tosoh Corporation "HLC-8420GPC" Column: Tosoh Corporation guard column "HXL-L" + Tosoh Corporation "TSK-GEL SuperHZ2000" + Tosoh Corporation "TSK-GEL SuperHZ2000" + Tosoh Corporation "TSK-GEL SuperHZ3000" + Tosoh Corporation "TSK-GEL SuperHZ4000" Detector: RI (differential refractometer) Data processing: Tosoh Corporation's "GPC Workstation EcoSEC-WorkStation" Column temperature: 40℃ Developing solvent: tetrahydrofuran Flow rate: 0.35mL / min Standard: The following monodisperse polystyrenes with known molecular weights were used in accordance with the measurement manual for the GPC Workstation EcoSEC-WorkStation. TSKgel F-10, F-4, F-1, A-5000, A-1000, A-500 (manufactured by Tosoh Corporation) Sample: 10 μL of a tetrahydrofuran solution containing 0.2% by mass of resin solids filtered through a microfilter

[0322] (IR measurement conditions) Measuring device: JASCO Corporation "FT / IR-4600"

[0323] Example 2: Synthesis of polyamide-imide resin (2) [ka]

[0324] A 1-liter four-necked round flask equipped with a stirrer, thermometer, condenser, dropping funnel, and Dean-Stark trap was charged with 66.60 g (0.30 mol) of isophorone diisocyanate (reagent), 49.37 g (0.26 mol) of trimellitic anhydride (reagent), 0.50 g of 1,4-diazabicyclo[2.2.2]octane (reagent) as a catalyst, and 100 g of diethylene glycol monoethyl ether acetate as a reaction solvent, in a composition ratio such that the average n value in the theoretical structural formula was 6.0 and the maleimide group equivalent was 1279 g / eq., and the mixture was stirred at 30°C. The mixture was then heated to 120°C and reacted at 120°C for 2 hours. The mixture was then heated to 150°C and reacted at 150°C for 8 hours, after which it was cooled to 30°C.

[0325] 16.20 g (0.09 mol) of N-(4-hydroxyphenyl)maleimide (reagent) was added to the reaction solution and dissolved at 30° C. The temperature was then raised to 60° C. and the reaction was carried out at 60° C. for 48 hours. The solution was microfiltered to remove impurities, and then diluted with diethylene glycol monoethyl ether acetate to obtain 197 g of a brown solution with a solid content of 50%.

[0326] Measurements were carried out by gel permeation chromatography (GPC) and infrared spectroscopy (IR) under the above GPC measurement conditions and IR measurement conditions, and it was confirmed that the resin was polyamideimide resin (2) (measured molecular weight Mn=2560).

[0327] Example 3: Synthesis of polyamide-imide resin (3) [ka]

[0328] In Example 1, 28.80 g (0.15 mol) of trimellitic anhydride (reagent) was changed to 29.70 g (0.15 mol) of cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride (reagent), so that the maleimide group equivalent was 467 g / eq., and the same procedure as in Example 1 was repeated to obtain 252 g of a brown solution with a solid content of 50%.

[0329] Measurements were carried out by gel permeation chromatography (GPC) and infrared spectroscopy (IR) under the above GPC measurement conditions and IR measurement conditions, and the resin was confirmed to be polyamideimide resin (3) (measured molecular weight Mn=930).

[0330] Example 4: Synthesis of polyamide-imide resin (4) [ka]

[0331] In Example 1, 28.80 g (0.15 mol) of trimellitic anhydride (reagent) was replaced with 29.70 g (0.15 mol) of cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride (reagent) and 66.60 g (0.30 mol) of isophorone diisocyanate (reagent) were replaced with 52.20 g (0.30 mol) of tolylene diisocyanate (reagent, a mixture of approximately 80% tolylene-2,4-diisocyanate and approximately 20% tolylene-2,6-diisocyanate), so that the maleimide group equivalent was 418 g / eq., and 226 g of a brown solution with a solid content of 50% was obtained in the same manner as in Example 1, except that the composition was changed so that the maleimide group equivalent was 418 g / eq.

[0332] Measurements were carried out by gel permeation chromatography (GPC) and infrared spectroscopy (IR) under the above GPC measurement conditions and IR measurement conditions, and the resin was confirmed to be polyamideimide resin (4) (measured molecular weight Mn=840).

[0333] Example 5: Synthesis of polyamide-imide resin (5) [ka]

[0334] A 1-liter four-necked round flask equipped with a stirrer, thermometer, condenser, dropping funnel, and Dean-Stark trap was charged with 52.20 g (0.30 mol) of tolylene diisocyanate (a mixture of approximately 80% tolylene-2,4-diisocyanate and approximately 20% tolylene-2,6-diisocyanate), 44.55 g (0.23 mol) of cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride (reagent), 0.50 g of 1,4-diazabicyclo[2.2.2]octane (reagent) as a catalyst, and 100 g of diethylene glycol monoethyl ether acetate as a reaction solvent, in a composition ratio such that the average n value in the theoretical structural formula was 3.0 and the maleimide group equivalent was 703 g / eq., and the mixture was stirred at 30 °C. The mixture was then heated to 120 °C and reacted at 120 °C for 2 hours. The temperature was further increased to 150°C, and the reaction was carried out at 150°C for 8 hours, after which the mixture was cooled to 30°C.

[0335] 56.70 g (0.30 mol) of N-(4-hydroxyphenyl)maleimide (reagent) was added to the reaction solution and dissolved at 30° C. The temperature was then raised to 60° C., and the reaction was carried out at 60° C. for 48 hours. The solution was microfiltered to remove impurities, and then diluted with diethylene glycol monoethyl ether acetate to obtain 215 g of a brown solution with a solid content of 50%.

[0336] Measurements were carried out by gel permeation chromatography (GPC) and infrared spectroscopy (IR) under the above GPC measurement conditions and IR measurement conditions, and the resin was confirmed to be polyamideimide resin (5) (measured molecular weight Mn=1410).

[0337] Example 6: Synthesis of polyamide-imide resin (6) [ka]

[0338] In Example 1, 260 g of a brown solution with a solid content of 50% was obtained in the same manner as in Example 1, except that 66.60 g (0.30 mol) of isophorone diisocyanate (reagent) was changed to 75.00 g (0.30 mol) of 4,4'-diphenylmethane diisocyanate, so that the maleimide group equivalent was 491 g / eq.

[0339] Measurements were carried out by gel permeation chromatography (GPC) and infrared spectroscopy (IR) under the above GPC measurement conditions and IR measurement conditions, and the resin was confirmed to be polyamideimide resin (6) (measured molecular weight Mn=980).

[0340] Example 7: Synthesis of polyamide-imide resin (7) [ka]

[0341] In Example 1, 220 g of a brown solution with a solid content of 50% was obtained in the same manner as in Example 1, except that 66.60 g (0.30 mol) of isophorone diisocyanate (reagent) was changed to 50.40 g (0.30 mol) of 1,6-hexane diisocyanate, so that the maleimide group equivalent was 409 g / eq.

[0342] Measurements were carried out by gel permeation chromatography (GPC) and infrared spectroscopy (IR) under the above GPC measurement conditions and IR measurement conditions, and the resin was confirmed to be polyamideimide resin (7) (measured molecular weight Mn=820).

[0343] Example 8: Synthesis of polyamide-imide resin (8) [ka] (In the formula, R 1 and R 2 is a hydrogen atom or a methyl group, and the adjacent R 1 and R 2 One is a hydrogen atom and the other is a methyl group.)

[0344] A 1-liter four-necked round flask equipped with a stirrer, thermometer, condenser, dropping funnel, and Dean-Stark trap was charged with 63.00 g (0.30 mol) of trimethylhexamethylene diisocyanate (reagent, 2,2,4- and 2,4,4-mixture), 46.08 g (0.24 mol) of trimellitic anhydride (reagent), 0.50 g of 1,4-diazabicyclo[2.2.2]octane (reagent) as a catalyst, and 100 g of diethylene glycol monoethyl ether acetate as a reaction solvent, in a composition ratio such that the average n value in the theoretical structural formula was 4.0 and the maleimide group equivalent was 923 g / eq., and the mixture was stirred at 30 °C. The mixture was then heated to 120 °C and reacted at 120 °C for 2 hours. The mixture was then heated to 150 °C and reacted at 150 °C for 8 hours, after which it was cooled to 30 °C.

[0345] 22.68 g (0.12 mol) of N-(4-hydroxyphenyl)maleimide (reagent) was added to the reaction solution and dissolved at 30° C. The temperature was then raised to 60° C. and the reaction was carried out at 60° C. for 48 hours. The solution was microfiltered to remove impurities, and then diluted with diethylene glycol monoethyl ether acetate to obtain 198 g of a brown solution with a solid content of 50%.

[0346] Measurements were carried out by gel permeation chromatography (GPC) and infrared spectroscopy (IR) under the above GPC measurement conditions and IR measurement conditions, and it was confirmed that the resin was polyamideimide resin (8) (measured molecular weight Mn=1850).

[0347] Comparative Example 1: Synthesis of polyamide-imide resin (C1) A 1-liter four-necked round flask equipped with a stirrer, thermometer, condenser, dropping funnel, and Dean-Stark trap was charged with 66.60 g (0.30 mol) of isophorone diisocyanate (reagent), 57.60 g (0.30 mol) of trimellitic anhydride (reagent), and 100 g of diethylene glycol monoethyl ether acetate as a reaction solvent, and the mixture was stirred at 30°C. The mixture was then heated to 120°C and reacted at 120°C for 5 hours, after which it was cooled to 30°C.

[0348] 70.41 g of Aronix M-305 (manufactured by Toagosei Co., Ltd., a mixture of compounds represented by the following formula, hydroxyl value 120 mgKOH / g) was added to the reaction solution and dissolved at 30°C. The temperature was then raised to 80°C, and the reaction was carried out at 80°C for 10 hours. The solution was microfiltered to remove impurities, and 310 g of a pale yellow solution with a solids content of 50% was obtained as polyamideimide resin (C1) not terminated with a maleimide group. [ka]

[0349] <Examples 9 to 16 and Comparative Example 2> (1) Preparation of resin composition A resin composition was prepared by mixing a 50% solids solution of the synthesized polyamideimide resins (1) to (8), a 50% solids solution of (C1), dicumyl peroxide (NOF Corporation's "Percumyl D"), and cyclohexanone according to the composition shown in Table 1. [Table 1]

[0350] (2) Preparation of resin sheet The prepared resin composition was applied to a polyimide film using a die coater so that the thickness of the resin composition layer after drying would be 50 μm, and then dried at 100° C. for 5 minutes to prepare a resin sheet.

[0351] (3) Manufacturing of cured products The prepared resin sheet was heated in an oven under a nitrogen atmosphere at 200°C for 120 minutes to thermally cure the resin composition layer, and then the polyimide film was peeled off to obtain a sheet-like cured product.

[0352] (4) Evaluation of the cured product The sheet-like cured products produced in Examples 9 to 16 and Comparative Example 2 were subjected to evaluation tests in the following manner. The results are shown in Table 1.

[0353] [Dielectric properties] The cured sheet was cut into test pieces of a specified size, and the dielectric constant (Dk) and dielectric loss tangent (Df) were measured at a measurement frequency of 5.8 GHz and 23°C using a split cylinder resonator (EM Lab "CR-710") and a PNA microwave network analyzer (Keysight "N5227B"). For each cured product, measurements were taken on five test pieces (n=5), and the average value was calculated.

[0354] [Heat resistance] The sheet-like cured product was cut into test pieces of a predetermined size, and the glass transition temperature (Tg) was measured using a dynamic viscoelasticity measuring device ("EXSTAR6100" manufactured by SII Nano Technology Co., Ltd.) under the measurement conditions of a load of 200 mN and a heating rate of 2°C / min.

[0355] <Examples 17 to 24 and Comparative Example 3> (1) Preparation of resin composition The solid resins (referred to as "HPC-" in Table 2) were obtained by removing the solvent from a 50% solid solution of the synthesized polyamide-imide resins (1) to (8), a 50% solid solution of (C1), dicumyl peroxide (NOF Corp.'s "Percumyl D"), a bisphenol liquid A-type epoxy resin (DIC Corp.'s "850S"), a biphenyl aralkyl epoxy resin (Nippon Kayaku Corp.'s "NC3000H"), and an activated ester resin (DIC Corp.'s "HPC-8000-62T"), each having the composition shown in Table 2. A resin composition was prepared by mixing methyl acrylate acrylate copolymer (labeled "8000" and having an active ester group equivalent of 220 g / eq.), 4-dimethylaminopyridine ("DMAP" manufactured by Koei Chemical Co., Ltd.), phenoxy resin ("YL6954BH30" manufactured by Mitsubishi Chemical Corporation, solid content 30% by mass), spherical silica ("SO-C2" manufactured by Admatechs Co., Ltd., average particle size 0.50 μm, treated with N-phenyl-3-aminopropyltrimethoxysilane), methyl ethyl ketone (MEK), and cyclohexanone. [Table 2]

[0356] (2) Preparation of resin sheet The prepared resin composition was applied to a polyethylene terephthalate film (thickness 38 μm, hereinafter referred to as "PET film") using a die coater so that the thickness of the resin composition layer after drying would be 40 μm, and the film was dried at 80°C to 120°C (average 100°C) for 6 minutes to produce a resin sheet.

[0357] (3) Manufacturing of cured products The prepared resin sheet was heated in an oven under a nitrogen atmosphere at 200°C for 120 minutes to thermally cure the resin composition layer, and then the PET film was peeled off to obtain a sheet-like cured product.

[0358] (4) Evaluation of the cured product The sheet-like cured product was subjected to evaluation tests in the following manner.

[0359] [Dielectric properties] The sheet-like cured products produced in Examples 17 to 24 and Comparative Example 3 were subjected to a dielectric property evaluation test in the same manner as in Examples 9 to 16 and Comparative Example 2.

[0360] [Smear removal] (Surface treatment for interior substrates) A glass cloth-based epoxy resin double-sided copper-clad laminate (copper foil thickness: 18 μm, substrate thickness: 0.8 mm, Panasonic "R1515A") was prepared as the inner layer substrate. The copper foil on the surface of this inner layer substrate was roughened by etching using a microetching agent (MEC "CZ8101") to remove 1 μm of copper. The substrate was then dried at 190°C for 30 minutes.

[0361] (Lamination and curing of resin sheets) The resin sheets obtained in Examples 17 to 24 and Comparative Example 3 were laminated onto both sides of the inner layer substrate using a batch-type vacuum pressure laminator (a two-stage build-up laminator "CVP700" manufactured by Nikko Materials Co., Ltd.) so that the resin composition layer was bonded to the inner layer substrate. This lamination was performed by reducing the pressure to 13 hPa or less for 30 seconds, and then pressing at a temperature of 100°C and a pressure of 0.74 MPa for 30 seconds.

[0362] The laminated resin sheet was then heat-pressed at atmospheric pressure at 100°C and a pressure of 0.5 MPa for 60 seconds to smooth it. It was then placed in a 130°C oven and heated for 30 minutes, and then transferred to a 170°C oven and heated for 30 minutes. The heating cured the resin composition layer, yielding an insulating layer containing a cured resin composition. Thus, the above procedure yielded an intermediate substrate having a layer structure of PET film / insulating layer / inner layer substrate / insulating layer / PET film.

[0363] (Via hole formation) The insulating layer was processed using a CO2 laser processing machine (LK-2K212 / 2C) manufactured by Via Mechanics, Inc., to form via holes in the insulating layer. The processing was performed under the following conditions: frequency 2000 Hz, pulse width 3 μs, output 0.95 W, and number of shots 3. The formed via holes had a top diameter (diameter) of 50 μm on the insulating layer surface and a diameter of 40 μm on the insulating layer bottom. The top diameter refers to the diameter of the opening of the via hole. The PET film was then peeled off.

[0364] (roughening treatment) The intermediate substrate was immersed in a swelling solution, Swelling Dip Securiganth P (manufactured by Atotech Japan), at 60°C for 10 minutes. Next, the intermediate substrate was immersed in a roughening solution, Concentrate Compact P (aqueous solution of KMnO4: 60 g / L, NaOH: 40 g / L) (manufactured by Atotech Japan), at 80°C for 20 minutes. After that, the intermediate substrate was immersed in a neutralizing solution, Reduction Solution Securiganth P (manufactured by Atotech Japan), at 40°C for 5 minutes. The resulting intermediate substrate is called evaluation substrate A.

[0365] (Evaluation of smear removal) The area around the bottom of the via hole (via bottom) of evaluation substrate A was observed using a scanning electron microscope (SEM). From the image obtained by this observation, the maximum smear length from the wall surface of the via hole bottom was measured and evaluated according to the following criteria. The maximum smear length represents the length of the longest smear formed at the bottom of the via hole. "○": Maximum smear length is less than 5 μm. "×": Maximum smear length is 5 μm or more.

[0366] [Helloing] A cross-section of evaluation substrate A was observed using a FIB-SEM hybrid system (SII Nanotechnology Corporation's "SMI3050SE"). Specifically, the insulating layer was removed using a focused ion beam (FIB) to reveal a cross section that was parallel to the thickness direction of the insulating layer and passed through the center of the via bottom of the via hole. This cross section was observed using an SEM. The bottom diameter and top diameter of the via hole were measured from the observed image. The bottom diameter refers to the diameter of the bottom of the via hole, and the top diameter refers to the diameter of the opening of the via hole.

[0367] Furthermore, in the image observed by SEM, a gap was observed that continued from the edge of the via bottom, where the insulating layer had peeled off from the copper foil of the inner layer substrate. From the observed image, the distance r1 from the center of the via bottom to the edge of the via bottom (corresponding to the inner radius of the gap) and the distance r2 from the center of the via bottom to the far end of the gap (corresponding to the outer radius of the gap) were measured, and the difference r2 - r1 between these distances r1 and r2 was calculated as the halo distance from the edge of the via bottom at that measurement point.

[0368] The above measurement was performed on five randomly selected via holes. The average of the top diameters of the five measured via holes was used as the top diameter Lt of the sample after the roughening treatment. The average of the bottom diameters of the five measured via holes was used as the bottom diameter Lb of the sample after the roughening treatment. Furthermore, the average of the halo distances of the five measured via holes was used as the halo distance Wb from the edge of the via bottom of the sample.

[0369] From the measurement results, the haloing ratio Hb (the ratio of the haloing distance Wb from the edge of the via bottom after the roughening treatment to the radius (Lb / 2) of the via bottom of the via hole after the roughening treatment, "Wb / (Lb / 2)") was calculated. If the haloing ratio Hb was 0.5 or less, it was judged as "◯", and if the haloing ratio Hb was greater than 0.5, it was judged as "X".

[0370] As shown in Tables 1 and 2, it was confirmed that when the polyamideimide resin of the present invention in which at least one end of the main chain is a maleimide group is used as a component of the resin composition, excellent dielectric properties are exhibited and heat resistance is improved.

Claims

1. A polyamide-imide resin in which at least one end of the main chain is a maleimide group.

2. The polyamideimide resin according to claim 1 , wherein both ends of the main chain are maleimide groups.

3. The polyamide-imide resin according to claim 1, which has a structure derived from a tricarboxylic acid anhydride and a structure derived from a diisocyanate.

4. The polyamideimide resin according to claim 1, which has a urethane bond in the main chain.

5. The polyamideimide resin according to claim 1 , wherein at least one of the terminals of the main chain is a maleimidearyloxy group.

6. 2. The polyamideimide resin according to claim 1, having a number average molecular weight (Mn) of 3,000 or less.

7. 2. The polyamideimide resin according to claim 1, wherein the maleimide group equivalent is 100 to 1500 g / eq.

8. The polyamideimide resin according to claim 1, having a structural unit represented by the following formula (X-1) and a structural unit represented by the following formula (X-2): 【Chemical 1】 (In formula (X-1), each A independently represents a trivalent organic group. In formula (X-2), each R independently represents a divalent organic group.)

9. The polyamideimide resin according to claim 1, having a structural unit represented by the following formula (X-3): 【Chemistry 2】 (In formula (X-3), each A independently represents a trivalent organic group. Each R independently represents a divalent organic group.)

10. The polyamide-imide resin according to claim 1, represented by the following formula (X-4): 【Chemistry 3】 (In formula (X-4), n represents an integer of 1 or more. Each A independently represents a trivalent organic group. Each R independently represents a divalent organic group. Each ring Ar independently represents an aromatic carbocyclic ring having 6 to 10 carbon atoms which may have a substituent selected from an alkyl group having 1 to 10 carbon atoms and an aryl group having 1 to 10 carbon atoms.)

11. 9. The polyamideimide resin according to claim 8, wherein in formula (X-1), A is a trivalent organic group having 3 to 20 carbon atoms and having a 6-membered ring.

12. The polyamide-imide resin according to claim 8, wherein in formula (X-2), R is an alkylene group having 1 to 20 carbon atoms which may have a substituent selected from an alkyl group having 1 to 6 carbon atoms and an aryl group having 1 to 10 carbon atoms, an arylene group having 1 to 20 carbon atoms which may have a substituent selected from an alkyl group having 1 to 6 carbon atoms and an aryl group having 1 to 10 carbon atoms, or a divalent group having 2 to 30 carbon atoms which is a combination thereof.

13. The polyamideimide resin according to claim 10, wherein in formula (X-4), ring Ar is a benzene ring.

14. The polyamideimide resin according to claim 10, wherein in formula (X-4), n is an integer of 1 to 20.

15. (1) a step of reacting a tricarboxylic acid anhydride with a diisocyanate to obtain a polyamide-imide resin having an isocyanate group at the end; and (2) reacting a polyamideimide resin having an isocyanate group at its terminal with an N-(hydroxyaryl)maleimide; A method for producing a polyamideimide resin, comprising:

16. The method for producing a polyamideimide resin according to claim 15, wherein the polyamideimide resin product is the polyamideimide resin according to any one of claims 1 to 14.

17. A curable resin comprising the polyamideimide resin according to any one of claims 1 to 14.

18. A resin composition comprising the polyamideimide resin according to any one of claims 1 to 14.

19. The resin composition according to claim 18, further comprising (b) a polymerization initiator.

20. The resin composition according to claim 18, further comprising (c1) an epoxy resin.

21. The resin composition according to claim 18, further comprising (d1) an epoxy resin curing agent.

22. The resin composition according to claim 18, further comprising (e) a curing accelerator.

23. The resin composition according to claim 18, further comprising (f) a thermoplastic resin.

24. The resin composition according to claim 18, further comprising (g) an inorganic filler.

25. The resin composition according to claim 18, further comprising (h) an organic solvent.

26. The resin composition according to claim 18, which is used for an insulating layer of a circuit board.

27. The resin composition according to claim 18, which is used for semiconductor encapsulation.

28. A resin sheet comprising a support and a layer of the resin composition according to claim 18 provided on the support.

29. The resin sheet according to claim 28, wherein the support is a thermoplastic resin film or a metal foil.

30. A prepreg obtained by impregnating a sheet-like fiber substrate with the resin composition according to claim 18.

31. A cured product of the resin composition according to claim 18.

32. A circuit board comprising an insulating layer made of a cured product of the resin composition according to claim 18.

33. A semiconductor chip package comprising an encapsulating layer made of a cured product of the resin composition according to claim 18.

34. 34. The semiconductor chip package of claim 33, which is a fan-out type package.

35. A semiconductor device comprising the circuit board of claim 32.

36. 34. A semiconductor device comprising the semiconductor chip package of claim 33.

Images