JP2024040963A - Curable resin composition, cured product, and article - Google Patents

Abstract

The present invention provides a curable resin composition capable of obtaining a cured product having a low elastic modulus, high adhesion to adjacent members, and excellent dielectric properties. [Solution] A compound containing an active ester resin (A) and a resin (B) having a polymerizable unsaturated group, wherein the active ester resin (A) has one phenolic hydroxyl group in its molecular structure. (a1), a phenolic hydroxyl group-containing resin (a2) containing a phenolic hydroxyl group-containing compound (a2-1) and a divinyl compound (a2-2) as essential reaction raw materials, and an aromatic polycarboxylic acid or its acid halide This is a curable resin composition characterized by using (a3) as an essential reaction raw material. [Selection diagram] None

Description

The present invention relates to a curable resin composition, a cured product, and an article.

Conventionally, when electronic components are mounted and soldered onto a printed wiring board, a film is formed to prevent solder from adhering to areas other than the mounting area, and to semi-permanently prevent oxidation and corrosion of wiring. Solder resist is widely used as a material. Technologies for forming such solder resist patterns include photoresist methods that can accurately form fine patterns; among these, alkaline-developed liquid photoresist methods are mainstream due to environmental considerations. It becomes.

For example, as an alkali-soluble photosensitive resin used in an alkaline-developable liquid photoresist method, a reaction product (acid Pendant type epoxy acrylate) is widely used, and a solder resist film is formed from a curable resin composition containing the alkali-soluble photosensitive resin (for example, see Patent Document 1). In addition to solder resists, curable resin compositions are also widely used in fields such as inks, paints, coating agents, adhesives, and optical members.

Furthermore, in recent years, it has been proposed to form a solder resist film by an inkjet method. When a solder resist film is formed by an inkjet method, development is not required, so the number of steps, time, and consumables can be reduced compared to the above-described alkaline development type liquid photoresist method. It is essential for ink for inkjet printing to have a low viscosity and not thicken, but the problem is that lowering the viscosity greatly reduces physical properties such as heat resistance and chemical resistance required for solder resists. was there. In contrast, epoxy acrylate, which is made by converting a part of epoxy resin into acrylate and can be cured by ultraviolet rays or heat, has been proposed as a material compatible with the inkjet method.

Special Publication No. 1-54390

On the other hand, in order to improve the reliability of mounting, the solder resist film is also required to have excellent adhesion to adjacent components (copper foil, etc.), and it is also required to have low elasticity so that it can follow the adjacent components. It is also important that there is.
Furthermore, as transmission signals become faster, a solder resist film exhibiting a low dielectric constant and a low dielectric loss tangent is required from the viewpoint of reducing time delay due to the use of high frequencies (gigahertz band).

In response to these demands, the above-mentioned epoxy acrylate has a hydroxyl group generated by acrylating an epoxy resin, and therefore has a high dielectric constant, making it difficult to apply to high frequency applications.
Furthermore, cured products obtained by curing conventional curable resin compositions containing alkali-soluble photosensitive resins have a high elastic modulus and are poor in adhesion to adjacent members and dielectric properties, leaving room for improvement.

Therefore, the present invention solves the problems of the prior art described above, and provides a cured product that has a low elastic modulus, high adhesion to adjacent members (copper foil, etc.), and excellent dielectric properties (low dielectric constant and dielectric loss tangent). An object of the present invention is to provide a curable resin composition that can be obtained.
A further object of the present invention is to provide a cured product that has a low elastic modulus, high adhesion to adjacent members, and excellent dielectric properties, and an article having a coating film made of such a cured product.

As a result of intensive studies to solve the above problems, the present inventors have cured a curable resin composition containing a specific active ester resin (A) and a resin having a polymerizable unsaturated group (B). It was discovered that the cured product obtained by this method has a low elastic modulus, high adhesion to adjacent members, and excellent dielectric properties, and the present invention has been completed.
That is, the gist of the present invention for solving the above problems is as follows.

[1] Contains an active ester resin (A) and a resin (B) having a polymerizable unsaturated group,
The active ester resin (A) contains a compound (a1) having one phenolic hydroxyl group in its molecular structure, a phenolic hydroxyl group-containing compound (a2-1), and a divinyl compound (a2-2) as essential reaction raw materials. A curable resin composition comprising a phenolic hydroxyl group-containing resin (a2) and an aromatic polycarboxylic acid or its acid halide (a3) as essential reaction raw materials.

[2] The number of moles of hydroxyl groups possessed by the compound (a1) having one phenolic hydroxyl group in the molecular structure (a1 _OH ) and the number of moles of hydroxyl groups possessed by the phenolic hydroxyl group-containing resin (a2) (a2 _OH ). The curable resin composition according to [1], wherein the ratio [(a1 _OH )/(a2 _OH )] is 10/90 to 75/25.

[3] The number of moles of hydroxyl groups possessed by the compound (a1) having one phenolic hydroxyl group in the molecular structure (a1 _OH ) and the number of moles of hydroxyl groups possessed by the phenolic hydroxyl group-containing resin (a2) (a2 _OH ). is 0.95 to 1.05 mol per 1 mol of the carboxyl groups or acid halide groups of the aromatic polycarboxylic acid or its acid halide (a3), [1] or [ 2].

[4] The curable resin composition according to any one of [1] to [3], wherein the active ester resin (A) has a weight average molecular weight (Mw) of 600 to 5,000.

[5] The solid content mass ratio [(A)/(B)] of the active ester resin (A) and the polymerizable unsaturated group-containing resin (B) is 5/95 to 50/50. , the curable resin composition according to any one of [1] to [4].

[6] The curable resin composition according to any one of [1] to [5], further containing a photopolymerization initiator.

[7] A cured product obtained by curing the curable resin composition according to any one of [1] to [6].

[8] An article comprising a coating film made of the cured product according to [7].

According to the present invention, a curable resin composition is capable of obtaining a cured product having a low elastic modulus, high adhesion to adjacent members (copper foil, etc.), and excellent dielectric properties (low dielectric constant and dielectric loss tangent). can provide things.
Further, according to the present invention, it is possible to provide a cured product having a low elastic modulus, high adhesion to adjacent members, and excellent dielectric properties, and an article having a coating film made of such a cured product.

Below, the curable resin composition, cured product, and article of the present invention will be illustrated in detail based on the embodiments thereof.

(Explanation of terms)
Unless otherwise specified in this specification, the following terminology is applicable.

In this specification, "alkyl group" includes, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, group, tert-pentyl group, neopentyl group, 1,2-dimethylpropyl group, n-hexyl group, isohexyl group, (n-)heptyl group, (n-)octyl group, (n-)nonyl group, (n- ) decyl group, (n-) undecyl group, (n-) dodecyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, or cyclononyl group.

In this specification, examples of the "aryl group" include a phenyl group, a naphthyl group, a phenalenyl group, a phenanthrenyl group, an anthryl group, an azulenyl group, an indenyl group, an indanyl group, a tetralinyl group, and the like. In addition, the "aryl group" means that the hydrogen atom of the aromatic ring in the aryl group is substituted with, for example, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a halogen atom. Good too.

In this specification, examples of the "aralkyl group" include a benzyl group, a diphenylmethyl group, a biphenyl group, a naphthylmethyl group, and the like.

In this specification, examples of "alkoxy groups (alkyloxy groups)" include methoxy groups, ethoxy groups, propoxy groups, isopropoxy groups, butoxy groups, pentyloxy groups, hexyloxy groups, 2-ethylhexyloxy groups, octyloxy groups, and nonyloxy groups.

In this specification, examples of the "halogen atom" include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like.

In this specification, "alkylene group" includes, for example, methylene group, ethylene group, propylene group, 1-methylmethylene group, 1,1-dimethylmethylene group, 1-methylethylene group, 1,1-dimethylethylene group. , 1,2-dimethylethylene group, propylene group, butylene group, 1-methylpropylene group, 2-methylpropylene group, pentylene group, hexylene group, heptylene group, octylene group, nonylene group, decylene group, undecylene group, dodecylene group etc.

In this specification, the "monovalent hydrocarbon group" includes, for example, the above alkyl group, and one or more -CH ₂ -s in the alkyl group are arranged so that -O- or It may be substituted with -S-, or one or more -CH ₂ -CH ₂ - in the alkyl group may be substituted with -CH=CH- so that they are not adjacent to each other.

In this specification, the "divalent hydrocarbon group" includes, for example, the above-mentioned alkylene group, and _-O- or It may be substituted with -S-, or one or more -CH ₂ -CH ₂ - in the alkylene group may be substituted with -CH=CH- so that they are not adjacent to each other.

As used herein, "(meth)acrylate" means acrylate and/or methacrylate. Moreover, in this specification, "(meth)acryloyl" means acryloyl and/or methacryloyl. Furthermore, in this specification, "(meth)acrylic" means acrylic and/or methacryl.

<Curable resin composition>
The curable resin composition of this embodiment contains an active ester resin (A) and a resin (B) having a polymerizable unsaturated group. In the curable resin composition of the present embodiment, the active ester resin (A) contains a compound (a1) having one phenolic hydroxyl group in its molecular structure, a phenolic hydroxyl group-containing compound (a2-1), and a divinyl A phenolic hydroxyl group-containing resin (a2) containing the compound (a2-2) as an essential reaction raw material, and an aromatic polycarboxylic acid or its acid halide (a3) as an essential reaction raw material.

In the curable resin composition of this embodiment, by using an active ester resin (A) using a phenolic hydroxyl group-containing resin (a2) as a reaction raw material and using a divinyl compound (a2-2) as a reaction raw material, the curable resin composition can be cured. By reducing the polarity of the cured product obtained by curing the polyurethane resin composition, the dielectric constant and the dielectric loss tangent are reduced, and the dielectric properties are improved.
In addition, since the active ester resin (A) using the divinyl compound (a2-2) as the reaction raw material and the phenolic hydroxyl group-containing resin (a2) as the reaction raw material has a low curing shrinkage rate, the curable resin composition of this embodiment A cured product obtained by curing a material has high adhesion to adjacent members (copper foil, etc.).
Furthermore, a cured product obtained by curing a curable resin composition containing an active ester resin (A) and a resin having a polymerizable unsaturated group (B) does not become too hard and has a low elastic modulus.

(Active ester resin (A))
The curable resin composition of this embodiment contains an active ester resin (A). The active ester resin (A) is
・Compound (a1) having one phenolic hydroxyl group in its molecular structure,
・A phenolic hydroxyl group-containing resin (a2) containing a phenolic hydroxyl group-containing compound (a2-1) and a divinyl compound (a2-2) as essential reaction raw materials, and ・Aromatic polycarboxylic acid or its acid halide (a3 )
is an essential reaction raw material.

--Compound (a1) having one phenolic hydroxyl group in its molecular structure--
The compound (a1) having one phenolic hydroxyl group in the molecular structure may be any aromatic compound having one hydroxyl group on the aromatic ring, and other specific structures are not particularly limited. The compound (a1) having one phenolic hydroxyl group in its molecular structure may be used singly or in combination of two or more. Specifically, the compound (a1) having one phenolic hydroxyl group in the molecular structure is a phenol compound having one or more substituents on phenol or the aromatic nucleus of phenol, naphthol, or a phenol compound having one or more substituents on the aromatic nucleus of phenol. Examples include naphthol compounds having one or more substituents, anthracenol or anthracenol compounds having one or more substituents on the aromatic nucleus of anthracenol. Substituents on the aromatic nucleus include, for example, aliphatic carbonization such as methyl group, ethyl group, vinyl group, propyl group, butyl group, pentyl group, hexyl group, cyclohexyl group, heptyl group, octyl group, nonyl group, etc. Hydrogen groups; alkoxy groups such as methoxy, ethoxy, propyloxy, and butoxy; halogen atoms such as fluorine, chlorine, and bromine; phenyl, naphthyl, and anthryl groups; Aliphatic hydrocarbon groups, alkoxy groups, aryl groups substituted with halogen atoms, etc.; phenylmethyl groups, phenylethyl groups, naphthylmethyl groups, naphthylethyl groups, and the above aliphatic hydrocarbon groups or alkoxy groups on these aromatic nuclei. , an aralkyl group substituted with a halogen atom, etc. Among these, naphthol compounds are preferred, and 1-naphthol or 2-naphthol is particularly preferred, since they provide an active ester resin with a low curing shrinkage rate and excellent dielectric properties in the cured product.

--Phenolic hydroxyl group-containing resin (a2)--
Regarding the phenolic hydroxyl group-containing resin (a2), the phenolic hydroxyl group-containing compound (a2-1) may be any aromatic compound having a hydroxyl group on an aromatic ring, and other specific structures are not particularly limited. . Specifically, compounds similar to the various compounds exemplified as the compound (a1) having one phenolic hydroxyl group in the molecular structure may be mentioned, and compounds having multiple phenolic hydroxyl groups in the molecular structure (multiple) may be mentioned. Functional phenols) can also be used. Here, examples of compounds having multiple phenolic hydroxyl groups in the molecular structure include hydroquinone, resorcinol, catechol, bisphenol A, bisphenol F, bisphenol S, bisphenol B, bisphenol AD, bisphenol Z, tetrabromobisphenol A, dihydroxydiphenyl ether, and phenol. Phthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, polyhydroxynaphthylene ether, dihydroxybenzophenone, trihydroxy Examples include benzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, and the like. Further, the phenolic hydroxyl group-containing compound (a2-1) may be used alone or in combination of two or more. Among these, naphthol compounds are preferred, and 1-naphthol or 2-naphthol is particularly preferred, since they provide active ester resins with low curing shrinkage and excellent dielectric properties in the cured product.

（式中、Ｒ^１は、それぞれ独立して脂肪族炭化水素基、アルコキシ基、ハロゲン原子、アリール基、アラルキル基の何れかであり、ｉは、０又は１～４の整数である。Ｙは、炭素原子数１～４のアルキレン基、酸素原子、硫黄原子、カルボニル基の何れかである。ｊは、１～４の整数である。）の何れかで表される化合物等が挙げられる。 The divinyl compound (a2-2) has at least two vinyl groups (-CH=CH ₂ ), and reacts with the phenolic hydroxyl group-containing compound (a2-1) to form the phenolic hydroxyl group-containing compound (a2). -1) Any compound may be used as long as it can bind the two together, and other specific structures are not particularly limited. Further, the divinyl compound (a2-2) may be used alone or in combination of two or more. Among these, compounds having an aromatic ring or cyclo ring in their molecular structure are preferred because they provide an active ester resin with a low curing shrinkage rate and excellent dielectric properties in the cured product. More preferable specific structures of the divinyl compound (a2-2) include, for example, the following structural formulas (1-1) to (1-4):

(In the formula, R ¹ is each independently an aliphatic hydrocarbon group, an alkoxy group, a halogen atom, an aryl group, or an aralkyl group, and i is 0 or an integer from 1 to 4. Y is , an alkylene group having 1 to 4 carbon atoms, an oxygen atom, a sulfur atom, or a carbonyl group (j is an integer of 1 to 4).

R ¹ in the structural formulas (1-1) to (1-4) are each independently an aliphatic hydrocarbon group, an alkoxy group, a halogen atom, an aryl group, or an aralkyl group, and specifically, is an aliphatic hydrocarbon group such as methyl group, ethyl group, vinyl group, propyl group, butyl group, pentyl group, hexyl group, cyclohexyl group, heptyl group, octyl group, nonyl group; methoxy group, ethoxy group , propyloxy group, butoxy group; halogen atoms such as fluorine atom, chlorine atom, bromine atom; phenyl group, naphthyl group, anthryl group; , an aryl group substituted with a halogen atom, etc.; a phenylmethyl group, a phenylethyl group, a naphthylmethyl group, a naphthylethyl group, and an aralkyl group substituted with the above-mentioned aliphatic hydrocarbon group, alkoxy group, halogen atom, etc. on the aromatic nucleus thereof; Examples include groups.

Among the compounds represented by any of the structural formulas (1-1) to (1-4), the active ester resin has a low curing shrinkage rate and has excellent dielectric properties in the cured product. A compound represented by formula (1-1) is preferred.

［式中、Ｘは、下記構造式（Ｘ－１）～（Ｘ－４）：

（式中、Ｒ^１は、それぞれ独立して脂肪族炭化水素基、アルコキシ基、ハロゲン原子、アリール基、アラルキル基の何れかであり、ｉは、０又は１～４の整数である。Ｙは、炭素原子数１～４のアルキレン基、酸素原子、硫黄原子、カルボニル基の何れかである。ｊは、１～４の整数である。）の何れかで表される構造部位である。］で表される構造部位（α）で結節された分子構造を有するものとなる。 When a compound represented by any of the structural formulas (1-1) to (1-4) is used as the divinyl compound (a2-2), the phenolic hydroxyl group-containing resin (a2) has a phenolic hydroxyl group. The containing compound (a2-1) has the following structural formula (2):

[Wherein, X is the following structural formulas (X-1) to (X-4):

(In the formula, R ¹ is each independently an aliphatic hydrocarbon group, an alkoxy group, a halogen atom, an aryl group, or an aralkyl group, and i is 0 or an integer from 1 to 4. Y is , an alkylene group having 1 to 4 carbon atoms, an oxygen atom, a sulfur atom, or a carbonyl group. j is an integer of 1 to 4). ] It has a molecular structure that is knotted at the structural site (α).

In addition to the phenolic hydroxyl group-containing compound (a2-1) and the divinyl compound (a2-2), other compounds may be used as reaction raw materials for the phenolic hydroxyl group-containing resin (a2). Other compounds include, for example, a compound (a2-2') which is a compound other than the divinyl compound (a2-2) and can bind the phenolic hydroxyl group-containing compound (a2-1), such as various aldehyde compounds; Substituent introduction agent (a2-3) for introducing an aliphatic hydrocarbon group, alkoxy group, halogen atom, aryl group, or aralkyl group as a substituent on the aromatic ring in the phenolic hydroxyl group-containing resin (a2-1) etc.

When the compound (a2-2') is used, the effects of low curing shrinkage and low dielectric loss tangent in the cured product are fully exhibited. The divinyl compound (a2-2) preferably accounts for 50% by mass or more, more preferably 80% by mass or more, based on the total amount of the divinyl compound (a2-2').

Examples of the substituent-introducing agent (a2-3) include aralkyl group-introducing agents such as phenylmethanol compounds, phenylmethyl halide compounds, naphthylmethanol compounds, naphthylmethyl halide compounds, and styrene compounds.

The method for producing the phenolic hydroxyl group-containing resin (a2) is not particularly limited, but it is preferable to adjust the ratio of reaction raw materials so that the number of phenolic hydroxyl groups per molecule is 2 or more. For example, the phenolic hydroxyl group-containing compound (a2-1) is used in an amount of 2 to 10 mol per 1 mol of the divinyl compound (a2-2), under acid catalytic conditions and at a temperature of about 80 to 180°C. It can be produced by a method of heating and stirring. The reaction may be carried out in an organic solvent if necessary. After the reaction is completed, an excess amount of the phenolic hydroxyl group-containing compound (a2-1) may be distilled off, if desired. Further, the unreacted phenolic hydroxyl group-containing compound (a2-1) in the reaction product may be used as it is as the compound (a1) having one phenolic hydroxyl group in its molecular structure.

Examples of the acid catalyst include para-toluenesulfonic acid, dimethyl sulfuric acid, diethyl sulfuric acid, sulfuric acid, hydrochloric acid, and oxalic acid. Each of these may be used alone or in combination of two or more. The amount of the acid catalyst added is preferably in the range of 0.01 to 10% by mass based on the phenolic hydroxyl group-containing compound (a2-1).

Examples of the organic solvent include ketone solvents such as acetone, methyl ethyl ketone, and cyclohexanone, acetate ester solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate, and carbitols such as cellosolve and butyl carbitol. Solvents include aromatic hydrocarbon solvents such as toluene and xylene, dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. Each of these may be used alone or as a mixed solvent of two or more.

As an example of the specific structure of the phenolic hydroxyl group-containing resin (a2), for example, when naphthol is used as the phenolic hydroxyl group-containing compound (a2-1) and divinylbenzene is used as the divinyl compound (a2-2), A structural example is shown in the following structural formula (2-1). Note that the following structural formula (2-1) is only an example of a specific structure of the phenolic hydroxyl group-containing resin (a2), and does not exclude other resin structures.

［式（２－１）中、ｎは、１～１０の整数である。Ｒは、それぞれ独立に水素原子又は下記構造式（Ｒ－１）：

で表される構造部位である。また、式（Ｒ－１）中、Ｒは、上記式（２－１）中のＲと同義であり、ｍは、１～１０の整数である。］

In formula (2-1), n is an integer of 1 to 10. Each R is independently a hydrogen atom or a group represented by the following structural formula (R-1):

In addition, in formula (R-1), R has the same meaning as R in formula (2-1) above, and m is an integer of 1 to 10.

Furthermore, commercially available divinylbenzene may contain a portion of ethylstyrene. In this case, a structure represented by the following structural formula (R-2) may be partially introduced as R in the above structural formula (2-1).

The hydroxyl equivalent of the phenolic hydroxyl group-containing resin (a2) is preferably in the range of 130 to 300 g/equivalent, since the active ester resin has high solvent solubility and is easy to use for various purposes.

--Aromatic polycarboxylic acid or its acid halide (a3)--
The aromatic polycarboxylic acid or its acid halide (a3) reacts with the phenolic hydroxyl group of the compound (a1) having one phenolic hydroxyl group in its molecular structure and the phenolic hydroxyl group-containing resin (a2). The specific structure is not particularly limited, and any compound may be used as long as it is an aromatic compound that can form an ester bond. Specific examples include benzenedicarboxylic acids such as isophthalic acid and terephthalic acid, benzenetricarboxylic acids such as trimellitic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-2,3-dicarboxylic acid, and naphthalene-2,6-dicarboxylic acid. - dicarboxylic acid, naphthalene dicarboxylic acid such as naphthalene-2,7-dicarboxylic acid, acid halides thereof, and compounds in which the above-mentioned aliphatic hydrocarbon group, alkoxy group, halogen atom, etc. are substituted on the aromatic nucleus thereof, etc. Can be mentioned. Examples of acid halides include acid chlorides, acid bromides, acid fluorides, and acid iodides. Each of these may be used alone or in combination of two or more. Among these, benzene dicarboxylic acids such as isophthalic acid and terephthalic acid or their acid halides are preferred because they provide active ester resins with high reaction activity and excellent curability.

--Production method--
The active ester resin (A) is, for example, a compound (a1) having one phenolic hydroxyl group in the molecular structure, the phenolic hydroxyl group-containing resin (a2), and the aromatic polycarboxylic acid or its acid halide. It can be produced by a method in which a reaction raw material that requires (a3) is heated and stirred in the presence of an alkali catalyst at a temperature of about 40 to 65°C. The reaction may be carried out in an organic solvent if necessary. Further, after the reaction is completed, the reaction product may be purified by washing with water, reprecipitation, etc., as desired.

Examples of the alkali catalyst include sodium hydroxide, potassium hydroxide, triethylamine, and pyridine. Each of these may be used alone or in combination of two or more. It may also be used as an aqueous solution of about 3.0 to 30%. Among these, sodium hydroxide or potassium hydroxide, which has high catalytic ability, is preferred.

Examples of the organic solvent include ketone solvents such as acetone, methyl ethyl ketone, and cyclohexanone; acetate ester solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; and carboxylic acid solvents such as cellosolve and butyl carbitol. Examples include toll solvents, aromatic hydrocarbon solvents such as toluene and xylene, dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. Each of these may be used alone or as a mixed solvent of two or more.

The reaction ratio of the compound (a1) having one phenolic hydroxyl group in the molecular structure, the phenolic hydroxyl group-containing resin (a2), and the aromatic polycarboxylic acid or its acid halide (a3) is determined according to the desired molecular structure. It can be changed as appropriate depending on the design. Among these, since the active ester resin has high solvent solubility and is easy to use for various purposes, the number of moles of hydroxyl group (a1 _OH ) of the compound (a1) having one phenolic hydroxyl group in the molecular structure The ratio of the number of moles of hydroxyl groups (a2 _OH ) possessed by the phenolic hydroxyl group-containing resin (a2) [(a1 _OH )/(a2 _OH )] is preferably a ratio of 10/90 to 75/25. , a ratio of 25/75 to 50/50 is more preferable.

Furthermore, the number of moles of hydroxyl groups (a1 _OH ) possessed by the compound (a1) having one phenolic hydroxyl group in the molecular structure and the number of moles of hydroxyl groups possessed by the phenolic hydroxyl group-containing resin (a2) (a2 _OH ). The total amount is preferably 0.95 to 1.05 mol per 1 mol of the carboxyl groups or acid halide groups possessed by the aromatic polycarboxylic acid or its acid halide (a3).

--Ester compound (a1-a3)--
The active ester resin (A) is an ester compound (a1-a3) of the compound (a1) having one phenolic hydroxyl group in the molecular structure and the aromatic polycarboxylic acid or its acid halide (a3). may partially contain. The ester compounds (a1-a3) include, for example, the compound (a1) having one phenolic hydroxyl group in the molecular structure, the phenolic hydroxyl group-containing resin (a2), and the aromatic polycarboxylic acid or its acid halogen. By adjusting the reaction ratio of compound (a3), it can be produced as one component of the active ester resin.

As an example of the specific structure of the ester compound (a1-a3), for example, a naphthol compound is used as the compound (a1) having one phenolic hydroxyl group in the molecular structure, and the aromatic polycarboxylic acid or its acid halide is used. A structural example when benzenedicarboxylic acid or its acid halide is used as (a3) is shown in the following structural formula (3). Note that the following structural formula (3) is only an example of a specific structure of the ester compounds (a1-a3), and does not exclude diester compounds having other molecular structures.

（式中、Ｒ^２は、それぞれ独立して脂肪族炭化水素基、アルコキシ基、ハロゲン原子、アリール基、アラルキル基の何れかであり、ナフタレン環を形成するどの炭素原子に結合していても良い。ｐは０又は１～３の整数である。）

(In the formula, R ² is each independently an aliphatic hydrocarbon group, an alkoxy group, a halogen atom, an aryl group, or an aralkyl group, and may be bonded to any carbon atom forming the naphthalene ring. .p is 0 or an integer from 1 to 3.)

When the active ester resin (A) contains the ester compounds (a1-a3), the content is such that the active ester resin has a low curing shrinkage rate and has excellent curability. It is preferably less than 40%, particularly preferably 10% or more and less than 35%.

The content of the ester compounds (a1-a3) in the active ester resin (A) is a value calculated from the area ratio of the GPC chart measured under the following conditions.

Measuring device: “HLC-8320 GPC” manufactured by Tosoh Corporation,
Column: Guard column “HXL-L” manufactured by Tosoh Corporation
+ “TSK-GEL G4000HXL” manufactured by Tosoh Corporation
+ “TSK-GEL G3000HXL” manufactured by Tosoh Corporation
+ “TSK-GEL G2000HXL” manufactured by Tosoh Corporation
+ “TSK-GEL G2000HXL” manufactured by Tosoh Corporation
Detector: RI (differential refractometer)
Data processing: “GPC Workstation EcoSEC-WorkStation” manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40℃
Developing solvent Tetrahydrofuran
Flow rate: 1.0 mL/min Standard: In accordance with the measurement manual for "GPC-8320", the following monodisperse polystyrene with a known molecular weight was used.
(Polystyrene used)
"A-500" manufactured by Tosoh Corporation
"A-1000" manufactured by Tosoh Corporation
"A-2500" manufactured by Tosoh Corporation
"A-5000" manufactured by Tosoh Corporation
"F-1" manufactured by Tosoh Corporation
"F-2" manufactured by Tosoh Corporation
"F-4" manufactured by Tosoh Corporation
"F-10" manufactured by Tosoh Corporation
"F-20" manufactured by Tosoh Corporation
"F-40" manufactured by Tosoh Corporation
"F-80" manufactured by Tosoh Corporation
"F-128" manufactured by Tosoh Corporation
Sample: A 1.0% by mass tetrahydrofuran solution (calculated as resin solid content) filtered through a microfilter (50μL)

--Physical properties--
The weight average molecular weight (Mw) of the active ester resin (A) is preferably in the range of 600 to 5,000, and preferably in the range of 800 to 3,000, since the active ester resin has a low curing shrinkage rate. It is particularly preferable that there be. Here, the weight average molecular weight (Mw) of the active ester resin (A) is a polystyrene equivalent value measured by GPC under the same conditions as when determining the content of the ester compounds (a1-a3).

The softening point of the active ester resin (A) is preferably in the range of 80 to 180°C, more preferably in the range of 85 to 160°C, as measured based on JIS K7234.

The functional group equivalent of the active ester resin (A) is preferably in the range of 100 to 500 g/equivalent, and 100 to 400 g, since the active ester resin has a low curing shrinkage rate and has excellent curability. /equivalent, and particularly preferably from 200 to 300 g/equivalent. Further, the ester group equivalent of the active ester resin (A) is preferably in the range of 200 to 500 g/equivalent, and 200 The range is more preferably 400 g/equivalent, and particularly preferably 200 to 300 g/equivalent. Here, the functional group in the active ester resin (A) refers to the ester bond site and the phenolic hydroxyl group in the active ester resin (A). Further, the functional group equivalent and ester group equivalent of the active ester resin (A) are values calculated from the charged amounts of reaction raw materials.

--Content--
The content of the active ester resin (A) in the total amount (100% by mass) of the curable resin composition of this embodiment is determined from the viewpoint of improving adhesiveness and dielectric properties in a well-balanced manner while lowering the elastic modulus. (nonvolatile content) is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, even more preferably 15% by mass or more, and preferably 80% by mass or less, and 60% by mass. % or less, more preferably 40% by mass or less.

(Resin (B) having a polymerizable unsaturated group)
The curable resin composition of this embodiment contains a resin (B) having a polymerizable unsaturated group. The resin (B) only needs to have a polymerizable unsaturated group, and other specific structures or molecular weights are not particularly limited, and a wide variety of resins can be used. Note that the resin (B) having a polymerizable unsaturated group has a polymerizable unsaturated group, but preferably does not have an acid group.

Examples of the polymerizable unsaturated group that the resin (B) has include a (meth)acryloyl group, an allyl group, an isopropenyl group, a 1-propenyl group, a styryl group, a styrylmethyl group, a maleimide group, and a vinyl ether group. It will be done.

Examples of the resin (B) having a polymerizable unsaturated group include the following [1] to [6]:
[1] Epoxy resin (B1) having a polymerizable unsaturated group,
[2] Urethane resin (B2) having a polymerizable unsaturated group,
[3] Acrylic resin (B3) having a polymerizable unsaturated group,
[4] Amidimide resin (B4) having a polymerizable unsaturated group,
[5] Acrylamide resin (B5) having a polymerizable unsaturated group,
[6] Ester resin (B6) having a polymerizable unsaturated group,
etc.
Among these, the epoxy resin (B1) having a polymerizable unsaturated group is preferable, and the effect of the present invention can be achieved by combining the active ester resin (A) and the epoxy resin (B1) having a polymerizable unsaturated group. noticeable. Further, as the resin (B) having a polymerizable unsaturated group, epoxy resins having a polymerizable unsaturated group described in Synthesis Example 7 and Synthesis Example 8 described in the Examples below are more preferable, and these resins have a polymerizable unsaturated group. The effects of the present invention are most noticeable when an epoxy resin having unsaturated groups is used.

--Epoxy resin (B1) having a polymerizable unsaturated group--
As the epoxy resin (B1) having a polymerizable unsaturated group, for example, an epoxy (meth)acrylate resin obtained by reacting an epoxy resin, an unsaturated monobasic acid, and, if necessary, a polybasic acid anhydride. ; Epoxy (meth)acrylate having a urethane group obtained by reacting an epoxy resin, an unsaturated monobasic acid, a polyisocyanate compound, a (meth)acrylate compound having a hydroxyl group, and, if necessary, a polybasic acid anhydride. Examples include resin; and the like. Note that, as described above, polybasic acid anhydride can be used as a reaction raw material for resin (B1), but it is preferable not to use it. The resin (B1) has a polymerizable unsaturated group, but preferably does not have an acid group. Moreover, it is preferable that the epoxy resin (B1) having a polymerizable unsaturated group has a polymerizable unsaturated group and an epoxy group in the same molecular chain. When the epoxy resin (B1) having a polymerizable unsaturated group has a polymerizable unsaturated group and an epoxy group in the same molecular chain, the epoxy group and the active ester group of the active ester resin (A) In response, the effects of the present invention are more prominently exhibited.

Examples of the epoxy resin include bisphenol type epoxy resin, hydrogenated bisphenol type epoxy resin, biphenol type epoxy resin, hydrogenated biphenol type epoxy resin, phenylene ether type epoxy resin, naphthylene ether type epoxy resin, biphenyl type epoxy resin, Triphenylmethane type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol novolac type epoxy resin, naphthol novolak type epoxy resin, naphthol-phenol cocondensed novolak type epoxy resin, naphthol-cresol cocondensed novolac type epoxy resin , phenol aralkyl type epoxy resin, naphthol aralkyl type epoxy resin, dicyclopentadiene-phenol addition reaction type epoxy resin, biphenylaralkyl type epoxy resin, fluorene type epoxy resin, xanthene type epoxy resin, dihydroxybenzene type epoxy resin, trihydroxybenzene type Examples include epoxy resins and oxazolidone-type epoxy resins. These epoxy resins may be used alone or in combination of two or more.

Examples of the bisphenol type epoxy resin include bisphenol A type epoxy resin, bisphenol AP type epoxy resin, bisphenol B type epoxy resin, bisphenol BP type epoxy resin, bisphenol E type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin. Examples include resin.
Examples of the hydrogenated bisphenol epoxy resin include hydrogenated bisphenol A epoxy resin, hydrogenated bisphenol B epoxy resin, hydrogenated bisphenol E epoxy resin, hydrogenated bisphenol F epoxy resin, and hydrogenated bisphenol S epoxy. Examples include resin.
Examples of the biphenol epoxy resin include 4,4'-biphenol epoxy resin, 2,2'-biphenol epoxy resin, tetramethyl-4,4'-biphenol epoxy resin, and tetramethyl-2,2' -Biphenol type epoxy resins, etc.
Examples of the hydrogenated biphenol epoxy resin include hydrogenated 4,4'-biphenol epoxy resin, hydrogenated 2,2'-biphenol epoxy resin, and hydrogenated tetramethyl-4,4'-biphenol epoxy resin. , hydrogenated tetramethyl-2,2'-biphenol type epoxy resin, and the like.

［上記一般式（４）中、Ｘ^４１は、炭素数１～１０のアルキレン鎖、ポリオキシアルキレン鎖、（ポリ）エステル鎖、芳香族炭化水素鎖、又は（ポリ）カーボネート鎖を表し、Ｘ^４１の構造中の水素原子がハロゲン原子又はアルコキシ基に置換されてもよく、Ｙ^４１は、水素原子又はメチル基である。］で表される化合物等も用いることができる。不飽和一塩基酸は、１種単独で用いてもよく、２種以上を組み合わせて用いてもよい。 Examples of the unsaturated monobasic acid include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, α-cyanocinnamic acid, β-styrylacrylic acid, β-furfurylacrylic acid, and the like. Furthermore, esters, acid halides, acid anhydrides, and the like of the unsaturated monobasic acids can also be used. Furthermore, as the unsaturated monobasic acid, the following general formula (4):

[In the above general formula (4), X ⁴¹ represents an alkylene chain, polyoxyalkylene chain, (poly)ester chain, aromatic hydrocarbon chain, or (poly)carbonate chain having 1 ^to 10 carbon atoms, The hydrogen atom in the structure may be substituted with a halogen atom or an alkoxy group, and Y ⁴¹ is a hydrogen atom or a methyl group. ] Compounds represented by the following can also be used. One type of unsaturated monobasic acid may be used alone, or two or more types may be used in combination.

［上記一般式（５）中、Ｒ^５１及びＲ^５２は、炭素原子数１～１０のアルキレン基を表し、ｎ^５１は１～５の整数を表す。］で表される（ポリ）エステル鎖が挙げられる。
前記芳香族炭化水素鎖としては、例えば、フェニレン鎖、ナフチレン鎖、ビフェニレン鎖、フェニルナフチレン鎖又はビナフチレン鎖等が挙げられる。また、部分構造として、ベンゼン環、ナフタレン環、アントラセン環、フェナントレン環等の芳香環を有する炭化水素鎖も用いることができる。
前記（ポリ）カーボネート鎖としては、例えば、下記一般式（６）：

［上記一般式（６）中、Ｒ^６１は、炭素原子数１～１０のアルキレン基を表し、ｎ^６１は１～５の整数を表す。］で表される（ポリ）カーボネート鎖が挙げられる。 Examples of the polyoxyalkylene chain include a polyoxyethylene chain and a polyoxypropylene chain.
As the (poly)ester chain, for example, the following general formula (5):

[In the above general formula (5), R ⁵¹ and R ⁵² represent an alkylene group having 1 to 10 carbon atoms, and n ⁵¹ represents an integer of 1 to 5. ] Examples include (poly)ester chains represented by the following.
Examples of the aromatic hydrocarbon chain include a phenylene chain, a naphthylene chain, a biphenylene chain, a phenylnaphthylene chain, and a binaphthylene chain. Further, as a partial structure, a hydrocarbon chain having an aromatic ring such as a benzene ring, a naphthalene ring, an anthracene ring, or a phenanthrene ring can also be used.
As the (poly)carbonate chain, for example, the following general formula (6):

[In the above general formula (6), R ⁶¹ represents an alkylene group having 1 to 10 carbon atoms, and n ⁶¹ represents an integer of 1 to 5. ] Examples include (poly)carbonate chains represented by the following.

Examples of the polybasic acid anhydrides include aliphatic polybasic acid anhydrides, alicyclic polybasic acid anhydrides, aromatic polybasic acid anhydrides, and the like. One type of polybasic acid anhydride may be used alone, or two or more types may be used in combination.

Examples of the aliphatic polybasic acid anhydrides include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, citraconic acid, and itaconic acid. Examples include acid anhydrides of acids, glutaconic acid, and 1,2,3,4-butanetetracarboxylic acid. Moreover, the aliphatic hydrocarbon group of the aliphatic polybasic acid anhydride may be either a linear type or a branched type, and may have an unsaturated bond in the structure.
In this specification, as the alicyclic polybasic acid anhydride, those in which an acid anhydride group is bonded to an alicyclic structure are referred to as alicyclic polybasic acid anhydrides; It does not matter whether the Examples of the alicyclic polybasic acid anhydride include tetrahydrophthalic acid, hexahydrophthalic acid, methylhexahydrophthalic acid, cyclohexanetricarboxylic acid, cyclohexanetetracarboxylic acid, bicyclo[2.2.1]heptane-2, 3-dicarboxylic acid, methylbicyclo[2.2.1]heptane-2,3-dicarboxylic acid, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene- Examples include acid anhydrides of 1,2-dicarboxylic acids.
Examples of the aromatic polybasic acid anhydrides include phthalic acid, trimellitic acid, pyromellitic acid, naphthalenedicarboxylic acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, biphenyldicarboxylic acid, biphenyltricarboxylic acid, biphenyltetracarboxylic acid, Examples include acid anhydride of benzophenone tetracarboxylic acid.

［上記一般式（７）中、Ｒ^７２及びＲ^７３はそれぞれ独立して、水素原子又は炭素原子数１～６の一価の炭化水素基のいずれかを表し、Ｒ^７１はそれぞれ独立して、炭素原子数１～４のアルキル基を表し、ｋ^７１は０又は１～３の整数であり、ｎ^７１は１以上の整数である。］で表される繰り返し構造を有するポリメチレンポリフェニルポリイソシアネート；これらのイソシアヌレート変性体、ビウレット変性体、アロファネート変性体等が挙げられる。前記ポリイソシアネート化合物は、１種単独で用いてもよく、２種以上を組み合わせて用いてもよい。 Examples of the polyisocyanate compound include aliphatic diisocyanate compounds such as butane diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate; norbornane diisocyanate, isophorone diisocyanate, Alicyclic diisocyanate compounds such as hydrogenated xylylene diisocyanate and hydrogenated diphenylmethane diisocyanate; tolylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-diisocyanate-3 , 3'-dimethylbiphenyl, o-toridine diisocyanate and other aromatic diisocyanate compounds; the following general formula (7):

[In the above general formula (7), R ⁷² and R ⁷³ each independently represent either a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, and R ⁷¹ each independently, It represents an alkyl group having 1 to 4 carbon atoms, k ⁷¹ is 0 or an integer of 1 to 3, and n ⁷¹ is an integer of 1 or more. ] A polymethylene polyphenyl polyisocyanate having a repeating structure represented by the following: isocyanurate-modified products, biuret-modified products, allophanate-modified products, etc. thereof. The polyisocyanate compounds may be used alone or in combination of two or more.

Examples of the (meth)acrylate compound having a hydroxyl group include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, trimethylolpropane (meth)acrylate, trimethylolpropane di(meth)acrylate, and pentaerythritol (meth)acrylate. acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol(meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate ) acrylate, dipentaerythritol penta(meth)acrylate, ditrimethylolpropane(meth)acrylate, ditrimethylolpropane di(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, and the like. In addition, (poly)oxyalkylene chains such as (poly)oxyethylene chains, (poly)oxypropylene chains, (poly)oxytetramethylene chains, etc. are introduced into the molecular structures of the (meth)acrylate compounds having various hydroxyl groups. (Poly)oxyalkylene modified products and lactone modified products in which a (poly)lactone structure is introduced into the molecular structure of the (meth)acrylate compounds having various hydroxyl groups can also be used.

The method for producing the epoxy resin (B1) having a polymerizable unsaturated group is not particularly limited, and any method may be used. The production of the epoxy resin (B1) having a polymerizable unsaturated group may be carried out in an organic solvent if necessary, and a basic catalyst may be used if necessary.

Examples of the organic solvent include hydrocarbon solvents such as toluene, xylene, heptane, hexane, and mineral spirits; ketone solvents such as methyl ethyl ketone, acetone, dimethyl formamide, methyl isobutyl ketone, cyclohexanone, and dimethyl acetamide; and tetrahydrofuran and dioxolane. Cyclic ether solvents; ester solvents such as methyl acetate, ethyl acetate, and butyl acetate; aromatic solvents such as toluene, xylene, and solvent naphtha; alicyclic solvents such as cyclohexane and methylcyclohexane; carbitol, cellosolve, methanol, ethanol, and propanol , isopropanol, butanol, cyclohexanol, propylene glycol monomethyl ether; ether solvents such as propyl ether, methyl cellosolve, cellosolve, butyl cellosolve, methyl carbitol; alkylene glycol monoalkyl ether, dialkylene glycol monoalkyl ether, di- Glycol ether solvents such as alkylene glycol monoalkyl ether acetate; vegetable oils and fats such as soybean oil, linseed oil, rapeseed oil, and safflower oil; methoxypropanol, cyclohexanone, methyl cellosolve, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, etc. It will be done. These organic solvents may be used alone or in combination of two or more.
Further, as the organic solvent, commercially available products can be used, and examples of the commercially available products include "No. 1 Spindle Oil", "No. 3 Solvent", "No. 4 Solvent", and "No. 5 Solvent" manufactured by ENEOS Corporation. "Solvent", "Solvent No. 6", "Naftesol H", "Alkene 56NT", "AF Solvent No. 4", "AF Solvent No. 5", "AF Solvent No. 6", "AF Solvent No. 7", manufactured by Mitsubishi Chemical Corporation "Diadol 13", "Diyaren 168";"FOxocol","F Oxocol 180" manufactured by Nissan Chemical Co., Ltd.; "Supersol LA35", "Supersol LA38" manufactured by Idemitsu Kosan Co., Ltd.; "Exsol D80" manufactured by ExxonMobil Chemical Co., Ltd. ”, “Exor D110”, “Exor D120”, “Exor D130”, “Exor D160”, “Exor D100K”, “Exor D120K”, “Exor D130K”, “Exor D280”, “Exor D300”, “Exor D320” ”; etc.

Examples of the basic catalyst include N-methylmorpholine, pyridine, 1,8-diazabicyclo[5.4.0]undecene-7 (DBU), and 1,5-diazabicyclo[4.3.0]nonene- 5 (DBN), 1,4-diazabicyclo[2.2.2]octane (DABCO), tri-n-butylamine or dimethylbenzylamine, butylamine, octylamine, monoethanolamine, diethanolamine, triethanolamine, imidazole, 1 -Methylimidazole, 2,4-dimethylimidazole, 1,4-diethylimidazole, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(N-phenyl)aminopropyltrimethoxysilane, 3-( Amine compounds such as 2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropylmethyldimethoxysilane, and tetramethylammonium hydroxide; class ammonium salts; phosphines such as trimethylphosphine, tributylphosphine, triphenylphosphine; tetramethylphosphonium chloride, tetraethylphosphonium chloride, tetrapropylphosphonium chloride, tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, trimethyl(2-hydroxylpropyl)phosphonium Phosphonium salts such as chloride, triphenylphosphonium chloride, benzylphosphonium chloride; dibutyltin dilaurate, octyltin trilaurate, octyltin diacetate, dioctyltin diacetate, dioctyltin dineodecanoate, dibutyltin diacetate, tin octylate, Organotin compounds such as 1,1,3,3-tetrabutyl-1,3-dodecanoyldistanoxane; Organometallic compounds such as zinc octylate and bismuth octylate; Inorganic tin compounds such as tin octoate; Inorganic metal compounds Examples include. Furthermore, alkaline earth metal hydroxides, alkali metal carbonates, alkali metal hydroxides, and the like can also be used. The basic catalysts may be used alone or in combination of two or more.

--Urethane resin (B2) having polymerizable unsaturated group--
As the urethane resin (B2) having a polymerizable unsaturated group, for example, a polyisocyanate compound, a (meth)acrylate compound having a hydroxyl group, and optionally a polyol compound and/or a polybasic acid anhydride are reacted. Examples include those obtained. Note that, as described above, polybasic acid anhydride can be used as a reaction raw material for resin (B2), but it is preferable not to use it. The resin (B2) has a polymerizable unsaturated group, but preferably does not have an acid group.

The polyisocyanate compound, the (meth)acrylate compound having a hydroxyl group, and the polybasic acid anhydride are the same as those already described for the resin (B1) and the like.

Examples of the polyol compounds include aliphatic polyol compounds such as ethylene glycol, propylene glycol, butanediol, hexanediol, glycerin, trimethylolpropane, ditrimethylolpropane, pentaerythritol, and dipentaerythritol; aromatic polyols such as biphenol and bisphenol; Polyol compound; (poly)oxyalkylene in which a (poly)oxyalkylene chain such as a (poly)oxyethylene chain, (poly)oxypropylene chain, or (poly)oxytetramethylene chain is introduced into the molecular structure of the various polyol compounds mentioned above. Modified products; lactone modified products in which a (poly)lactone structure is introduced into the molecular structure of the various polyol compounds mentioned above, 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolvaleric acid etc. The polyol compounds may be used alone or in combination of two or more.

The method for producing the urethane resin (B2) having a polymerizable unsaturated group is not particularly limited, and any method may be used. The production of the urethane resin (B2) having a polymerizable unsaturated group may be carried out in an organic solvent if necessary, and a basic catalyst may be used if necessary. In that case, the organic solvent and basic catalyst are the same as those already described for the resin (B1) and the like.

--Acrylic resin having polymerizable unsaturated group (B3)--
As the acrylic resin (B3) having a polymerizable unsaturated group, for example, a (meth)acrylate compound (α) having a reactive functional group such as a hydroxyl group, a carboxyl group, an isocyanate group, or a glycidyl group is polymerized as an essential component. A reaction obtained by introducing a (meth)acryloyl group by further reacting the resulting acrylic resin intermediate with a (meth)acrylate compound (β) having a reactive functional group that can react with these functional groups. Examples include those obtained by reacting a polybasic acid anhydride with a hydroxyl group in the product and, if necessary, in the reaction product. Note that, as described above, the polybasic acid anhydride can be used as a reaction raw material for the resin (B3), but it is preferable not to use it. The resin (B3) has a polymerizable unsaturated group, but preferably does not have an acid group.

In addition to the (meth)acrylate compound (α), the acrylic resin intermediate may be one obtained by copolymerizing other compounds having polymerizable unsaturated groups as necessary. Examples of the other compounds having polymerizable unsaturated groups include (meth)acrylate, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. ) Acrylic acid alkyl ester; alicyclic structure-containing (meth)acrylates such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate; phenyl (meth)acrylate, benzyl (meth)acrylate, Examples include aromatic ring-containing (meth)acrylates such as phenoxyethyl acrylate; (meth)acrylates having a silyl group such as 3-methacryloxypropyltrimethoxysilane; and styrene derivatives such as styrene, α-methylstyrene, and chlorostyrene. The other compounds having polymerizable unsaturated groups may be used alone or in combination of two or more.

The (meth)acrylate compound (β) is not particularly limited as long as it can react with the reactive functional group possessed by the (meth)acrylate compound (α), but from the viewpoint of reactivity it should be the following combination: is preferred. That is, when water (meth)acrylate is used as the (meth)acrylate compound (α), it is preferable to use a (meth)acrylate having an isocyanate group as the (meth)acrylate compound (β). When a (meth)acrylate having a carboxyl group is used as the (meth)acrylate compound (α), it is preferable to use a (meth)acrylate having a glycidyl group as the (meth)acrylate compound (β). When a (meth)acrylate having an isocyanate group is used as the (meth)acrylate compound (α), it is preferable to use water (meth)acrylate as the (meth)acrylate compound (β). When a (meth)acrylate having a glycidyl group is used as the (meth)acrylate compound (α), it is preferable to use a (meth)acrylate having a carboxyl group as the (meth)acrylate compound (β). The (meth)acrylate compound (β) may be used alone or in combination of two or more.

The polybasic acid anhydride is the same as that already described for the resin (B1) and the like.

The method for producing the acrylic resin (B3) having a polymerizable unsaturated group is not particularly limited, and any method may be used. The production of the acrylic resin (B3) having a polymerizable unsaturated group may be carried out in an organic solvent if necessary, and a basic catalyst may be used if necessary. In that case, the organic solvent and basic catalyst are the same as those already described for the resin (B1) and the like.

--Amidimide resin (B4) having a polymerizable unsaturated group--
The amide-imide resin (B4) having a polymerizable unsaturated group is, for example, an amide-imide resin having an acid group and/or an acid anhydride group, and a (meth)acrylate compound having a hydroxyl group and/or a (meth)acrylate compound having an epoxy group. ) Those obtained by reacting an acrylate compound with a compound having one or more reactive functional groups selected from the group consisting of a hydroxyl group, a carboxyl group, an isocyanate group, a glycidyl group, and an acid anhydride group, if necessary. can be mentioned. Note that the compound having a reactive functional group may or may not have a (meth)acryloyl group. Note that the resin (B4) has a polymerizable unsaturated group, but preferably does not have an acid group.

The amide-imide resin having an acid group and/or an acid anhydride group may have either one of the acid group or the acid anhydride group, or may have both. However, from the viewpoint of reactivity and reaction control with a (meth)acrylate compound having a hydroxyl group or an epoxy compound having a (meth)acryloyl group, the amide-imide resin having an acid group and/or an acid anhydride group may be an acid anhydride. It is preferable to have a chemical group, and more preferably to have both an acid group and an acid anhydride group. The solid content acid value of the amide-imide resin is preferably in the range of 60 to 350 mgKOH/g as measured under neutral conditions, ie, under conditions where the acid anhydride group is not ring-opened. On the other hand, it is preferable that the value measured under conditions where the acid anhydride group is ring-opened, such as in the presence of water, is in the range of 61 to 360 mgKOH/g.

Examples of the amide-imide resin having an acid group and/or an acid anhydride group include those obtained by using a polyisocyanate compound and a polybasic acid anhydride as reaction raw materials. In that case, the polyisocyanate compound and polybasic acid anhydride are the same as those already described for the resin (B1) and the like. Note that, as described above, polybasic acid anhydride can be used as a reaction raw material for resin (B4), but it is preferable not to use it. Furthermore, as a reaction raw material for the amide-imide resin having an acid group and/or an acid anhydride group, a polybasic acid can be used in combination with the polyisocyanate compound and polybasic acid anhydride, if necessary.

Any compound having two or more carboxyl groups in one molecule can be used as the polybasic acid. For example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydro Phthalic acid, methylhexahydrophthalic acid, citraconic acid, itaconic acid, glutaconic acid, 1,2,3,4-butanetetracarboxylic acid, cyclohexanetricarboxylic acid, cyclohexanetetracarboxylic acid, bicyclo[2.2.1]heptane- 2,3-dicarboxylic acid, methylbicyclo[2.2.1]heptane-2,3-dicarboxylic acid, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydro Examples include naphthalene-1,2-dicarboxylic acid, trimellitic acid, pyromellitic acid, naphthalenedicarboxylic acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, biphenyldicarboxylic acid, biphenyltricarboxylic acid, biphenyltetracarboxylic acid, benzophenonetetracarboxylic acid, etc. It will be done. Further, as the polybasic acid, for example, a copolymer of a conjugated diene vinyl monomer and acrylonitrile, which has a carboxyl group in its molecule, can also be used. These polybasic acids may be used alone or in combination of two or more.

The (meth)acrylate compound having a hydroxyl group is the same as that already described for the resin (B1) and the like.

Examples of the (meth)acrylate compound having an epoxy group include (meth)acrylates having a glycidyl group such as glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, and epoxycyclohexylmethyl (meth)acrylate. Monomers include mono(meth)acrylates of diglycidyl ether compounds such as dihydroxybenzene diglycidyl ether, dihydroxynaphthalene diglycidyl ether, biphenol diglycidyl ether, and bisphenol diglycidyl ether. The (meth)acrylate compound having an epoxy group may be used alone or in combination of two or more.

The method for producing the amide-imide resin (B4) having a polymerizable unsaturated group is not particularly limited, and any method may be used. In the production of the amide-imide resin (B4) having a polymerizable unsaturated group, it may be carried out in an organic solvent as necessary, and a basic catalyst may be used as necessary. In that case, the organic solvent and basic catalyst are the same as those already described for the resin (B1) and the like.

--Acrylamide resin having polymerizable unsaturated group (B5)--
The acrylamide resin (B5) having a polymerizable unsaturated group includes, for example, a compound having a phenolic hydroxyl group, an alkylene oxide or an alkylene carbonate, an N-alkoxyalkyl (meth)acrylamide compound, and, if necessary, a polybase. Examples include those obtained by reacting acid anhydrides and unsaturated monobasic acids. Note that, as described above, polybasic acid anhydride can be used as a reaction raw material for resin (B5), but it is preferable not to use it. The resin (B5) has a polymerizable unsaturated group, but preferably does not have an acid group.

The compound having a phenolic hydroxyl group refers to a compound having at least one phenolic hydroxyl group in the molecule. Examples of the compound having at least one phenolic hydroxyl group in the molecule include compounds represented by the following general formulas (8.1) to (8.5).

［上記一般式（８．１）～（８．５）中、Ｒ^８１～Ｒ^８４及びＲ^８７はそれぞれ独立して、炭素原子数１～２０のアルキル基、炭素原子数１～２０のアルコキシ基、アリール基又はハロゲン原子のいずれかを表し、Ｒ^８５及びＲ^８６はそれぞれ独立して、水素原子又はメチル基を表し、ｊ^８１～ｊ^８４及びｊ^８７はそれぞれ独立して、０又は１以上の整数を表し、好ましくは０又は１～３の整数であり、より好ましくは０又は１である。ｋ^８１～ｋ^８４及びｋ^８７はそれぞれ独立して、１以上の整数を表し、好ましくは、２又は３である。］
なお、上記一般式（８．１）～（８．５）における芳香環上の置換基の位置については、任意であり、例えば、一般式（８．２）のナフタレン環においてはいずれの環上の水素原子と置換してもよく、一般式（８．３）では、ビフェニル１分子中に存在するベンゼン環のいずれの水素原子に置換してもよく、一般式（８．４）では、アラルキル１分子中に存在するベンゼン環のいずれかの水素原子と置換してもよく、一般式（８．５）では、１分子中に存在するベンゼン環のいずれの水素原子と置換していてもよいことを示し、１分子中における置換基の個数がｊ^８１～ｊ^８４、ｊ^８７及びｋ^８１～ｋ^８４、ｋ^８７であることを示している。

[In the above general formulas (8.1) to (8.5), R ⁸¹ to R ⁸⁴ and R ⁸⁷ are each independently an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, , represents either an aryl group or a halogen atom, R ⁸⁵ and R ⁸⁶ each independently represent a hydrogen atom or a methyl group, and j ⁸¹ to j ⁸⁴ and j ⁸⁷ each independently represent 0 or one or more It represents an integer, preferably 0 or an integer from 1 to 3, more preferably 0 or 1. k ⁸¹ to k ⁸⁴ and k ⁸⁷ each independently represent an integer of 1 or more, preferably 2 or 3. ]
In addition, the position of the substituent on the aromatic ring in the above general formulas (8.1) to (8.5) is arbitrary. For example, in the naphthalene ring of the general formula (8.2), the position of the substituent on any ring In general formula (8.3), any hydrogen atom in the benzene ring present in one biphenyl molecule may be substituted, and in general formula (8.4), aralkyl It may be substituted with any hydrogen atom of the benzene ring present in one molecule, and in general formula (8.5), it may be substituted with any hydrogen atom of the benzene ring present in one molecule. This shows that the number of substituents in one molecule is j ⁸¹ to j ⁸⁴ , j ⁸⁷ and k ⁸¹ to k ⁸⁴ , k ⁸⁷ .

Further, as the compound having a phenolic hydroxyl group, for example, a compound having at least one phenolic hydroxyl group in the molecule, a compound represented by any of the following general formulas (9.1) to (9.5), and Examples include reaction products that use formaldehyde and/or formaldehyde as an essential reaction raw material. Further, a novolac type phenol resin, etc., which uses one or more kinds of compounds having at least one phenolic hydroxyl group in the molecule as a reaction raw material can also be used.

［上記一般式（９．１）～（９．５）中、ｈ^９１は、０又は１を表し、Ｒ^９１～Ｒ^９６はそれぞれ独立して、一価の脂肪族炭化水素基、アルコキシ基、ハロゲン原子、アリール基、アリールオキシ基又はアラルキル基のいずれかを表し、ｋ^９１～ｋ^９６はそれぞれ独立して、０又は１～４の整数を表し、Ｚ^９１～Ｚ^９６はそれぞれ独立して、ビニル基、ハロメチル基、ヒドロキシメチル基又はアルキルオキシメチル基のいずれかを表し、Ｙ^９１は、炭素原子数１～４のアルキレン基、酸素原子、硫黄原子又はカルボニル基のいずれかを表し、ｎ^９１は１～４の整数を表す。］

[In the above general formulas (9.1) to (9.5), h ⁹¹ represents 0 or 1, and R ⁹¹ to R ⁹⁶ each independently represent a monovalent aliphatic hydrocarbon group, an alkoxy group, represents either a halogen atom, an aryl group, an aryloxy group or an aralkyl group, k ⁹¹ to k ⁹⁶ each independently represent 0 or an integer of 1 to 4, Z ⁹¹ to Z ⁹⁶ each independently, Represents either a vinyl group, halomethyl group, hydroxymethyl group, or alkyloxymethyl group, Y ⁹¹ represents any one of an alkylene group having 1 to 4 carbon atoms, an oxygen atom, a sulfur atom, or a carbonyl group, n ⁹¹ represents an integer from 1 to 4. ]

Specific examples of the compound having a phenolic hydroxyl group include phenol, cresol, xylenol; dialkylphenol such as dimethylphenol and diethylphenol; trialkylphenol such as trimethylphenol and triethylphenol; diphenylphenol, triphenylphenol, catechol, resorcinol, Hydroquinone, 3-methylcatechol, 4-methylcatechol, 4-allylpyrocatechol, tetramethylbisphenol A, 1,2,3-trihydroxybenzene, 1,2,4-trihydroxybenzene, 1-naphthol, 2-naphthol , 1,3-naphthalene diol, 1,5-naphthalene diol, 2,6-naphthalene diol, 2,7-naphthalene diol, polyphenylene ether diol, polynaphthylene ether diol, phenol novolac resin, cresol novolac resin, bisphenol Examples include novolac type resins, naphthol novolak type resins, phenol aralkyl type resins, naphthol aralkyl type resins, and phenol resins having a cyclo ring structure. The compounds having a phenolic hydroxyl group may be used alone or in combination of two or more.

Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, and pentylene oxide. The alkylene oxides may be used alone or in combination of two or more. Among these, ethylene oxide or propylene oxide is preferable as the alkylene oxide.

Examples of the alkylene carbonate include ethylene carbonate, propylene carbonate, butylene carbonate, pentylene carbonate, and the like. The alkylene carbonates may be used alone or in combination of two or more. Among these, ethylene carbonate or propylene carbonate is preferable as the alkylene carbonate.

Examples of the N-alkoxyalkyl (meth)acrylamide compounds include N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide, and N-methoxyethyl (meth)acrylamide. , N-ethoxyethyl (meth)acrylamide, N-butoxyethyl (meth)acrylamide, and the like. The N-alkoxyalkyl (meth)acrylamide compounds may be used alone or in combination of two or more.

The polybasic acid anhydride and unsaturated monobasic acid are the same as those already described for the resin (B1) and the like.

The method for producing the acrylamide resin (B5) having a polymerizable unsaturated group is not particularly limited, and any method may be used. In the production of the acrylamide resin (B5) having a polymerizable unsaturated group, it may be carried out in an organic solvent as necessary, and a basic catalyst and an acidic catalyst may be used as necessary. In that case, the organic solvent and basic catalyst are the same as those already described for the resin (B1) and the like.

Examples of the acidic catalyst include inorganic acids such as hydrochloric acid, sulfuric acid, and phosphoric acid; organic acids such as methanesulfonic acid, p-toluenesulfonic acid, and oxalic acid; and Lewis acids such as boron trifluoride, anhydrous aluminum chloride, and zinc chloride. Examples include. Furthermore, a solid acid catalyst having a strong acid such as a sulfonyl group can also be used. These acidic catalysts may be used alone or in combination of two or more.

--Ester resin (B6) having polymerizable unsaturated group--
The ester resin (B6) having a polymerizable unsaturated group includes, for example, a compound having a phenolic hydroxyl group, an alkylene oxide or an alkylene carbonate, an unsaturated monobasic acid, and, if necessary, a polybasic acid anhydride. Examples include those obtained by reaction. Note that, as described above, polybasic acid anhydride can be used as a reaction raw material for resin (B6), but it is preferable not to use it. The resin (B6) has a polymerizable unsaturated group, but preferably does not have an acid group.

The compound having a phenolic hydroxyl group, alkylene oxide, alkylene carbonate, unsaturated monobasic acid, and polybasic acid anhydride are the same as those already described for resin (B1), resin (B5), and the like.

The method for producing the ester resin (B6) having a polymerizable unsaturated group is not particularly limited, and any method may be used. In the production of the ester resin (B6) having a polymerizable unsaturated group, it may be carried out in an organic solvent as necessary, and a basic catalyst and an acidic catalyst may be used as necessary. In that case, the organic solvent, basic catalyst, and acidic catalyst are the same as those already described for resin (B1), resin (B5), and the like.

--Content--
The content of the resin (B) having a polymerizable unsaturated group in the total amount (100% by mass) of the curable resin composition of the present embodiment is such that it improves adhesion and dielectric properties in a well-balanced manner while lowering the elastic modulus. From this point of view, the solid content (non-volatile content) is preferably 20% by mass or more, more preferably 40% by mass or more, even more preferably 60% by mass or more, and preferably 99% by mass or less, more preferably 95% by mass or less. , more preferably 90% by mass or less, even more preferably 85% by mass or less.

Further, in the curable resin composition of the present embodiment, the solid content (nonvolatile content) mass ratio [(A)/( B)] is preferably 5/95 to 50/50, more preferably 10/90 to 30/70, from the viewpoint of improving adhesion and dielectric properties in a well-balanced manner while lowering the elastic modulus. preferable.

The curable resin composition of the present embodiment may be composed only of the active ester resin (A) and the polymerizable unsaturated group-containing resin (B), but may further contain a photopolymerization initiator, etc., which will be described later. You may.
The total content of the active ester resin (A) and the polymerizable unsaturated group-containing resin (B) in the total amount (100% by mass) of the curable resin composition of the present embodiment is such that the elastic modulus is low, and From the viewpoint of improving adhesion and dielectric properties in a well-balanced manner, the content is preferably 50% by mass or more, more preferably 60% by mass or more, and preferably 95% by mass or less, and more preferably 90% by mass or less.

(Photopolymerization initiator)
It is preferable that the curable resin composition of this embodiment further contains a photopolymerization initiator. When the curable resin composition contains a photopolymerization initiator, the curing reaction (polymerization) by light is easily initiated. The photopolymerization initiators may be used alone or in combination of two or more.

The photopolymerization initiator can be appropriately selected and used depending on the type of active energy ray to be irradiated. Further, it may be used in combination with a photosensitizer such as an amine compound, a urea compound, a sulfur-containing compound, a phosphorus-containing compound, a chlorine-containing compound, or a nitrile compound. Further, the photopolymerization initiator is preferably a radical polymerization initiator.

Specific examples of the photopolymerization initiator include 1-hydroxycyclohexyl-phenyl-ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone, and 1,2-(dimethylamino). Alkylphenone photopolymerization initiator such as -2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone; 2,4,6-trimethylbenzoyl-diphenyl- Examples include acylphosphine oxide photopolymerization initiators such as phosphine oxide; and intramolecular hydrogen abstraction type photopolymerization initiators such as benzophenone compounds. Further, specific examples of the photopolymerization initiator include 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2- Methyl-1-propan-1-one, thioxanthone and thioxanthone derivatives, 2,2'-dimethoxy-1,2-diphenylethan-1-one, diphenyl(2,4,6-trimethoxybenzoyl)phosphine oxide, bis( Also included are 2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, and the like.
Commercially available photopolymerization initiators include, for example, "Omnirad-1173", "Omnirad-184", "Omnirad-127", "Omnirad-2959", "Omnirad-369", "Omnirad-379", " Omnirad-907”, “Omnirad-4265”, “Omnirad-1000”, “Omnirad-651”, “Omnirad-TPO”, “Omnirad-819”, “Omnirad-2022”, “Omnirad-2100”, “Omnirad - 754'', ``Omnirad-784'', ``Omnirad-500'', ``Omnirad-81'' (manufactured by IGM), ``Kayacure-DETX'', ``Kayacure-MBP'', ``Kayacure-DMBI'', ``Kayacure-EPA'', “Kayacure-OA” (manufactured by Nippon Kayaku Co., Ltd.), “Bicure-10”, “Bicure-55” (manufactured by Stouffer Chemical Co., Ltd.), “Trigonal P1” (manufactured by Akzo Co., Ltd.), “Sandray 1000” (manufactured by Sandoz Co., Ltd.) ), "Deep" (manufactured by Upjohn), "Quantacure-PDO", "Quantacure-ITX", "Quantacure-EPD" (manufactured by Ward Blenkinsop), "Runtecure-1104" (manufactured by Runtec) ) etc.

When the photopolymerization initiator is used, the content of the photopolymerization initiator in the curable resin composition of the present embodiment is determined based on the amount of the photopolymerization initiator in the solid state of the active ester resin (A) and the polymerizable unsaturated group-containing resin (B). It is preferable that the content is 0.1 parts by mass or more and 10 parts by mass or less, based on a total of 100 parts by mass of non-volatile components.

(Optional addition ingredient)
The curable resin composition of this embodiment may further contain optional additive components within a range that does not deviate from the purpose. Examples of optional additive components include compounds having polymerizable unsaturated groups, curing agents, curing accelerators, other resins, organic solvents, polymerization inhibitors, antioxidants, flame retardants, fillers, pigments, and antifoaming agents. , viscosity modifiers, leveling agents, ultraviolet light stabilizers, storage stabilizers, and other various additives.

--Compound having a polymerizable unsaturated group--
Examples of the compound having a polymerizable unsaturated group include (meth)acrylate compounds, specifically, for example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and butyl (meth)acrylate. Aliphatic mono(meth)acrylate compounds such as acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate; cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, Alicyclic mono(meth)acrylate compounds such as adamantyl mono(meth)acrylate; heterocyclic mono(meth)acrylate compounds such as glycidyl(meth)acrylate and tetrahydrofurfuryl acrylate; benzyl(meth)acrylate, phenyl(meth)acrylate Acrylate, phenylbenzyl (meth)acrylate, phenoxy (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxyethoxyethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, phenoxybenzyl (meth)acrylate, Mono(meth)acrylate compounds such as aromatic mono(meth)acrylate compounds such as benzylbenzyl(meth)acrylate and phenylphenoxyethyl(meth)acrylate: (poly) in the molecular structure of the various mono(meth)acrylate monomers mentioned above. (Poly)oxyalkylene-modified mono(meth)acrylate compounds into which polyoxyalkylene chains such as oxyethylene chains, (poly)oxypropylene chains, and (poly)oxytetramethylene chains have been introduced; A lactone-modified mono(meth)acrylate compound with a (poly)lactone structure introduced into its molecular structure;
Aliphatic di(meth)acrylate compounds such as ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butanediol di(meth)acrylate, hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, etc. ;1,4-Cyclohexane dimethanol di(meth)acrylate, norbornane di(meth)acrylate, norbornane dimethanol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate Alicyclic di(meth)acrylate compounds such as; aromatic di(meth)acrylate compounds such as biphenol di(meth)acrylate and bisphenol di(meth)acrylate; Polyoxyalkylene-modified di(meth)acrylate compounds into which a (poly)oxyalkylene chain such as a (poly)oxyethylene chain, (poly)oxypropylene chain, or (poly)oxytetramethylene chain is introduced; the various di(meth)acrylate compounds mentioned above A lactone-modified di(meth)acrylate compound with a (poly)lactone structure introduced into the molecular structure of the acrylate compound;
Aliphatic tri(meth)acrylate compounds such as trimethylolpropane tri(meth)acrylate and glycerin tri(meth)acrylate; (poly)oxyethylene chain, (poly) in the molecular structure of the aliphatic tri(meth)acrylate compound; A (poly)oxyalkylene-modified tri(meth)acrylate compound into which a (poly)oxyalkylene chain such as an oxypropylene chain or a (poly)oxytetramethylene chain is introduced; A lactone-modified tri(meth)acrylate compound with a poly)lactone structure;
Tetrafunctional or higher functional aliphatic poly(meth)acrylate compounds such as pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate; Tetrafunctional or higher (poly)oxyalkylene-modified poly(meth) with (poly)oxyalkylene chains such as (poly)oxyethylene chains, (poly)oxypropylene chains, (poly)oxytetramethylene chains introduced into the molecular structure Acrylate compound; a tetrafunctional or higher-functional lactone-modified poly(meth)acrylate compound in which a (poly)lactone structure is introduced into the molecular structure of the aliphatic poly(meth)acrylate compound;
Hydroxyethyl (meth)acrylate, Hydroxypropyl (meth)acrylate, Trimethylolpropane (meth)acrylate, Trimethylolpropane di(meth)acrylate, Pentaerythritol (meth)acrylate, Pentaerythritol di(meth)acrylate, Pentaerythritol tri( meth)acrylate, dipentaerythritol (meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, ditrimethylol (Meth)acrylate compounds having a hydroxyl group such as propane (meth)acrylate, ditrimethylolpropane di(meth)acrylate, and ditrimethylolpropane tri(meth)acrylate; ) A (poly)oxyalkylene modified product into which a (poly)oxyalkylene chain such as an oxyethylene chain, a (poly)oxypropylene chain, or a (poly)oxytetramethylene chain is introduced; the molecular structure of the (meth)acrylate compound having the hydroxyl group. Lactone modified product with a (poly)lactone structure introduced inside;
(meth)acrylate compounds having an isocyanate group such as 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, 1,1-bis(acryloyloxymethyl)ethyl isocyanate;
(meth)acrylate monomers having a glycidyl group such as glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, epoxycyclohexylmethyl (meth)acrylate, droxybenzene diglycidyl ether, dihydroxynaphthalene diglycidyl ether , biphenol diglycidyl ether, and mono(meth)acrylate compounds of diglycidyl ether compounds of bisphenol diglycidyl ether.
The compounds having a polymerizable unsaturated group may be used alone or in combination of two or more.

--Curing agent--
Examples of the curing agent include epoxy resins and other curing agents (amine curing agents, acid anhydride curing agents, phenolic resin curing agents, etc.), and among these, epoxy resins are preferred. When the curing agent is an epoxy resin, the epoxy group of the epoxy resin and the active ester group of the active ester resin (A) react, and the effects of the present invention are more pronounced.

The epoxy resin is not particularly limited, but is preferably a curable resin that contains two or more epoxy groups in its molecule and can be cured by forming a crosslinked network with the epoxy groups. Examples of epoxy resins include, but are not limited to, phenol novolak epoxy resins, cresol novolac epoxy resins, α-naphthol novolac epoxy resins, β-naphthol novolac epoxy resins, bisphenol A novolak epoxy resins, biphenyl novolac epoxy resins. Novolac type epoxy resins such as; aralkyl type epoxy resins such as phenol aralkyl type epoxy resins, naphthol aralkyl type epoxy resins, phenol biphenylaralkyl type epoxy resins; bisphenol A type epoxy resins, bisphenol AP type epoxy resins, bisphenol AF type epoxy resins, Bisphenol type epoxy resins such as bisphenol B type epoxy resin, bisphenol BP type epoxy resin, bisphenol C type epoxy resin, bisphenol E type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, tetrabromobisphenol A type epoxy resin; Biphenyl-type epoxy resins such as biphenyl-type epoxy resins, tetramethylbiphenyl-type epoxy resins, epoxy resins having a biphenyl skeleton and diglycidyloxybenzene skeleton; naphthalene-type epoxy resins; binaphthol-type epoxy resins; binaphthyl-type epoxy resins; dicyclopentadiene phenol dicyclopentadiene type epoxy resin such as type epoxy resin; glycidylamine type epoxy resin such as tetraglycidyldiaminodiphenylmethane type epoxy resin, triglycidyl-p-aminophenol type epoxy resin, glycidylamine type epoxy resin of diaminodiphenylsulfone; 2, Diglycidyl ester type epoxy resins such as 6-naphthalene dicarboxylic acid diglycidyl ester type epoxy resins and glycidyl ester type epoxy resins of hexahydrophthalic anhydride; benzopyran types such as dibenzopyran, hexamethyldibenzopyran, and 7-phenylhexamethyldibenzopyran Examples include epoxy resin. Among these epoxy resins, so-called glycidyl ether type epoxy resins obtained by epoxidizing a phenol compound are preferred, and among these, novolac type epoxy resins, aralkyl type epoxy resins, and dicyclopentadiene type epoxy resins are preferred because of their dielectric properties. It is more preferable from the viewpoint of The above-mentioned epoxy resins may be used alone or in combination of two or more.

The epoxy equivalent of the epoxy resin is preferably 120 to 400 g/eq, more preferably 150 to 300 g/eq. When the epoxy equivalent of the epoxy resin is 120 g/eq or more, it is preferable because the dielectric properties of the obtained cured product are better. On the other hand, when the epoxy equivalent of the epoxy resin is 400 g/eq or less, the heat resistance of the obtained cured product improves. This is preferable because it has an excellent balance between properties and dielectric loss tangent.
The softening point of the epoxy resin is preferably 20 to 200°C, more preferably 40 to 150°C, from the viewpoint of improving dielectric properties and adhesion in a well-balanced manner.

The amine curing agent is not particularly limited, but includes diethylenetriamine (DTA), triethylenetetramine (TTA), tetraethylenepentamine (TEPA), dipropylene diamine (DPDA), diethylaminopropylamine (DEAPA), and N-aminoethyl. Aliphatic amines such as piperazine, menzendiamine (MDA), isophoronediamine (IPDA), 1,3-bisaminomethylcyclohexane (1,3-BAC), piperidine, N,N,-dimethylpiperazine, triethylenediamine; m-xylene diamine (XDA), methanephenylene diamine (MPDA), diaminodiphenylmethane (DDM), diaminodiphenylsulfone (DDS), benzylmethylamine, 2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethyl) Examples include aromatic amines such as (aminomethyl) phenol.
Examples of the acid anhydride curing agent include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bis trimellitate, glycerol tris trimellitate, maleic anhydride, tetrahydrophthalic anhydride, Methyltetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, methylbutenyltetrahydrophthalic anhydride, dodecenylsuccinic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, succinic anhydride, Examples include methylcyclohexenedicarboxylic anhydride.
Examples of the phenolic resin curing agent include phenol novolak resin, cresol novolak resin, naphthol novolak resin, bisphenol novolak resin, biphenyl novolak resin, dicyclopentadiene-phenol addition type resin, phenol aralkyl resin, naphthol aralkyl resin, and triphenol methane type resin. , tetraphenolethane type resin, aminotriazine modified phenol resin, and the like.
Any of the other curing agents mentioned above may be used alone or in combination of two or more.

When using the curing agent, the content of the curing agent in the curable resin composition of the present embodiment is determined based on the solid content (nonvolatile content) of the active ester resin (A) and the resin (B) having a polymerizable unsaturated group. ) is preferably 10 to 40 parts by weight based on 100 parts by weight of the total amount. When the amount is 10 parts by mass or more, heat resistance and curability can be further improved, and when it is 40 parts by mass or less, a lower dielectric loss tangent and higher flexibility can be obtained.

--Curing accelerator--
Examples of the curing accelerator include, but are not particularly limited to, phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, urea-based curing accelerators, and the like. One type of curing accelerator may be used alone, or two or more types may be used in combination.

Examples of the phosphorus curing accelerator include organic phosphine compounds such as triphenylphosphine, tributylphosphine, triparatolylphosphine, diphenylcyclohexylphosphine, and tricyclohexylphosphine; organic phosphite compounds such as trimethylphosphite and triethylphosphite; ethyltriphenyl; Phosphonium bromide, benzyltriphenylphosphonium chloride, butylphosphonium tetraphenylborate, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, triphenylphosphine triphenylborane, tetraphenylphosphonium thiocyanate, tetraphenylphosphonium dicyanamide, Examples include phosphonium salts such as butylphenylphosphonium dicyanamide and tetrabutylphosphonium decanoate.
Examples of the amine curing accelerator include triethylamine, tributylamine, N,N-dimethyl-4-aminopyridine (DMAP), 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo[5, Examples thereof include 4,0]-undecene-7 (DBU) and 1,5-diazabicyclo[4,3,0]-nonene-5 (DBN).
Examples of the imidazole curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecyl imidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and 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-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2-phenylimidazole isocyanuric acid adduct , 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2 -Methyl-3-benzylimidazolium chloride, 2-methylimidazoline and the like.
Examples of the guanidine-based curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 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-butylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, and the like.
Examples of the urea-based curing accelerator include 3-phenyl-1,1-dimethylurea, 3-(4-methylphenyl)-1,1-dimethylurea, chlorophenylurea, 3-(4-chlorophenyl)-1,1 -dimethylurea, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, and the like.
Among the above-mentioned curing accelerators, it is preferable to use 2-ethyl-4-methylimidazole and N,N-dimethyl-4-aminopyridine (DMAP).

When the curing accelerator is used, the content of the curing accelerator in the curable resin composition of the present embodiment is determined by the solid content ( The amount is preferably 0.01 to 5 parts by weight based on 100 parts by weight of the total amount of nonvolatile components. When the content of the curing accelerator is 0.01 part by mass or more, curability can be more reliably improved. On the other hand, when the content of the curing accelerator is 5 parts by mass or less, insulation reliability can be maintained sufficiently well. From the same viewpoint, the content of the curing accelerator is based on 100 parts by mass of the total solid content (nonvolatile content) of the active ester resin (A) and the polymerizable unsaturated group-containing resin (B). It is more preferably 0.1 parts by mass or more, and more preferably 5 parts by mass or less.

--Other resins--
Examples of the other resins include, but are not limited to, maleimide resins, polyphenylene ether resins, polyimide resins, cyanate ester resins, benzoxazine resins, triazine-containing cresol novolak resins, cyanate ester resins, styrene-maleic anhydride resins, diallyl bisphenol. Examples include allyl group-containing resins such as and triallyl isocyanurate, polyphosphoric acid esters, and phosphoric acid ester-carbonate copolymers. These other resins may be used alone or in combination of two or more.
When using the other resin, the content of the other resin in the curable resin composition of this embodiment is preferably 50% by mass or less of the total.

--Organic solvent--
The organic solvent can have a function of adjusting the viscosity of the curable resin composition. Specific examples of organic solvents include, but are not limited to, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether solvents such as diethyl ether and tetrahydrofuran; ethyl acetate, butyl acetate, cellosolve acetate, and propylene glycol monomethyl. Ester solvents such as ether acetate and carbitol acetate; carbitols such as cellosolve and butyl carbitol; toluene, xylene, ethylbenzene, mesitylene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, etc. Examples include aromatic hydrocarbons, amide solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. The organic solvents may be used alone or in combination of two or more.
When using the organic solvent, the content of the organic solvent in the curable resin composition of the present embodiment is preferably 90% by mass or less based on the total amount (100% by mass) of the curable resin composition, and 10 to 10% by mass. It is more preferably 90% by mass, and even more preferably from 20 to 80% by mass. It is preferable that the content of the organic solvent is 10% by mass or more because it provides excellent handling properties. On the other hand, it is preferable from the viewpoint of economic efficiency that the content of the organic solvent is 90% by mass or less.

--Polymerization inhibitor--
The polymerization inhibitor is not particularly limited, but includes p-methoxyphenol (methoquinone), p-methoxycresol, 4-methoxy-1-naphthol, 4,4'-dialkoxy-2,2'-bi-1- Naphthol, 3-(N-salicyloyl)amino-1,2,4-triazole, N'1,N'12-bis(2-hydroxybenzoyl)dodecane dihydrazide, styrenated phenol, N-isopropyl-N'-phenylbenzene -1,4-diamine, phenolic compounds such as 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline;
Quinone compounds such as hydroquinone, methylhydroquinone, p-benzoquinone, methyl-p-benzoquinone, 2,5-diphenylbenzoquinone, 2-hydroxy-1,4-naphthoquinone, anthraquinone, diphenoquinone;
Melamine, p-phenylenediamine, 4-aminodiphenylamine, N,N'-diphenyl-p-phenylenediamine, Ni-propyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine, diphenylamine, 4,4'-dicumyl-diphenylamine, 4,4'-dioctyl-diphenylamine, poly(2,2,4-trimethyl-1,2-dihydroquinoline), styrene amine compounds such as styrenated diphenylamine, reaction products of styrenated diphenylamine and 2,4,4-trimethylpentene, and reaction products of diphenylamine and 2,4,4-trimethylpentene;
Phenothiazine, distearylthiodipropionate, 2,2-bis({[3-(dodecylthio)propionyl]oxy}methyl)-1,3-propanediylbis[3-(dodecylthio)propionate], ditridecane-1- yl=3,3'-sulfanediyl dipropanoate and other thioether compounds;
N-nitrosodiphenylamine, N-nitrosophenylnaphthylamine, p-nitrosophenol, nitrosobenzene, p-nitrosodiphenylamine, α-nitroso-β-naphthol, N,N-dimethyl p-nitrosoaniline, p-nitrosodiphenylamine, p-nitrone Dimethylamine, p-nitrone-N,N-diethylamine, N-nitrosoethanolamine, N-nitrosodi-n-butylamine, N-nitroso-Nn-butyl-4-butanolamine, N-nitroso-diisopropanolamine, N-nitroso-N-ethyl-4-butanolamine, 5-nitroso-8-hydroxyquinoline, N-nitrosomorpholine, N-nitroso-N-phenylhydroxylamine ammonium salt, nitrosobenzene, N-nitroso-N-methyl- p-Toluenesulfonamide, N-nitroso-N-ethylurethane, N-nitroso-Nn-propylurethane, 1-nitroso-2-naphthol, 2-nitroso-1-naphthol, 1-nitroso-2-naphthol- Nitroso compounds such as sodium 3,6-sulfonate, sodium 2-nitroso-1-naphthol-4-sulfonate, 2-nitroso-5-methylaminophenol hydrochloride, 2-nitroso-5-methylaminophenol hydrochloride;
Ester of phosphoric acid and octadecane-1-ol, triphenylphosphite, 3,9-dioctadecan-1-yl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, tris Nonylphenyl phosphite, phosphorous acid-(1-methylethylidene)-di-4,1-phenylenetetra-C12-15-alkyl ester, 2-ethylhexyl diphenyl phosphite, diphenylisodecyl phosphite, triisodecyl phosphite phosphite compounds such as phyto, tris(2,4-di-tert-butylphenyl) phosphite;
Zinc compounds such as bis(dimethyldithiocarbamato-κ(2)S,S')zinc, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate;
Nickel compounds such as bis(N,N-dibutylcarbamodithioato-S,S')nickel;
1,3-dihydro-2H-benzimidazole-2-thione, 4,6-bis(octylthiomethyl)-o-cresol, 2-methyl-4,6-bis[(octan-1-ylsulfanyl)methyl] Examples include sulfur compounds such as phenol, dilaurylthiodipropionate, and distearyl 3,3'-thiodipropionate.
The polymerization inhibitors may be used alone or in combination of two or more.

--Antioxidant--
The antioxidant is not particularly limited, but compounds similar to those exemplified as polymerization inhibitors can be used. The antioxidants may be used alone or in combination of two or more.

Examples of commercially available polymerization inhibitors and antioxidants include "Q-1300" and "Q-1301" manufactured by Wako Pure Chemical Industries, Ltd., "Sumilizer BBM-S" and "Sumilizer GA" manufactured by Sumitomo Chemical Co., Ltd. -80ga'', etc.

--Flame retardants--
Examples of the flame retardant include, but are not particularly limited to, inorganic phosphorus flame retardants, organic phosphorus flame retardants, halogen flame retardants, and the like. The flame retardants may be used alone or in combination of two or more.

Examples of the inorganic phosphorus flame retardant include, but are not limited to, red phosphorus; ammonium phosphates such as monoammonium phosphate, diammonium phosphate, triammonium phosphate, and ammonium polyphosphate; and phosphoric acid amides.
The organic phosphorus flame retardant is not particularly limited, but includes methyl acid phosphate, ethyl acid phosphate, isopropyl acid phosphate, dibutyl phosphate, monobutyl phosphate, butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, and bis(2-ethylhexyl). Phosphate, monoisodecyl acid phosphate, lauryl acid phosphate, tridecyl acid phosphate, stearyl acid phosphate, isostearyl acid phosphate, oleyl acid phosphate, butyl pyrophosphate, tetracosyl acid phosphate, ethylene glycol acid phosphate, (2-hydroxyethyl ) Phosphoric acid esters such as methacrylate acid phosphate; 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, diphenylphosphine such as diphenylphosphine oxide; 10-(2,5-dihydroxyphenyl)-10H- 9-Oxa-10-phosphaphenanthrene-10-oxide, 10-(1,4-dioxynaphthalene)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, diphenylphosphinylhydroquinone, diphenylphos Phosphorus-containing phenols such as phenyl-1,4-dioxynaphthalene, 1,4-cyclooctylenephosphinyl-1,4-phenyldiol, and 1,5-cyclooctylenephosphinyl-1,4-phenyldiol ;9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 10 -(2,7-dihydroxynaphthyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide and other cyclic phosphorus compounds; the phosphoric acid ester, the diphenylphosphine, the phosphorus-containing phenol, and an epoxy resin or Examples include compounds obtained by reacting with aldehyde compounds and phenol compounds.
The halogen flame retardant is not particularly limited, but includes brominated polystyrene, bis(pentabromophenyl)ethane, tetrabromobisphenol A bis(dibromopropyl ether), 1,2,-bis(tetrabromophthalimide), 2, Examples include 4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine and tetrabromophthalic acid.

When using the flame retardant, the amount of the flame retardant used in the resin composition of the present embodiment is determined based on the solid content (nonvolatile content) of the active ester resin (A) and the polymerizable unsaturated group-containing resin (B). The amount is preferably 0.1 to 50 parts by weight based on 100 parts by weight of the total amount. When the content of the flame retardant is 0.1 part by mass or more, flame retardancy can be imparted more reliably. On the other hand, when the content of the flame retardant is 50 parts by mass or less, flame retardancy can be imparted while maintaining dielectric properties. From the same viewpoint, the content of the flame retardant is 1 part by mass based on 100 parts by mass of the total solid content (nonvolatile content) of the active ester resin (A) and the polymerizable unsaturated group-containing resin (B). It is more preferably at least 30 parts by mass, and more preferably at most 30 parts by mass.

--filler--
Examples of the filler include organic fillers and inorganic fillers. The organic filler has a function of improving elongation, a function of improving mechanical strength, and the like. Inorganic fillers have functions such as reducing the coefficient of thermal expansion and imparting flame retardancy. The above-mentioned fillers may be used alone or in combination of two or more.

The organic filler is not particularly limited, but includes polyamide particles and the like.
The inorganic filler is not particularly limited, but includes silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, and nitride. Boron, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate , calcium zirconate, zirconium phosphate, zirconium tungstate phosphate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, carbon black and the like. Among these, it is preferable to use silica. In this case, as the silica, amorphous silica, fused silica, crystalline silica, synthetic silica, hollow silica, etc. can be used.

Further, the filler may be surface-treated if necessary. At this time, surface treatment agents that can be used include, but are not particularly limited to, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, organosilazane compounds, titanate coupling agents, etc. A ring agent or the like may be used. Specific examples of surface treatment agents include 3-glycidoxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, and hexamethyldimethoxysilane. Examples include silazane. In addition, the above-mentioned fillers may be used alone or in combination of two or more.

When the filler is used, the amount of the filler used in the resin composition of the present embodiment is based on the solid content (nonvolatile content) of the active ester resin (A) and the resin (B) having a polymerizable unsaturated group. The amount is preferably 0.5 to 95 parts by weight based on 100 parts by weight of the total amount. When the content of the filler is 0.5 parts by mass or more, the effect of the filler can be sufficiently imparted. On the other hand, when the content of the filler is 95 parts by mass or less, deterioration of moldability due to the increase in the viscosity of the compound can be suppressed. From the same point of view, the filler content is 5 parts by mass based on 100 parts by mass of the total solid content (nonvolatile content) of the active ester resin (A) and the polymerizable unsaturated group-containing resin (B). It is more preferably at least 80 parts by mass, and more preferably at most 80 parts by mass.

The method for producing the curable resin composition of this embodiment is not particularly limited, and can be produced by kneading the various components described above using a kneader such as a roll.

<Cured product>
The cured product of this embodiment is characterized by being formed by curing the above-mentioned curable resin composition. The cured product of this embodiment has a low elastic modulus, high adhesion to adjacent members, excellent dielectric properties, and can suitably function as an insulating material or a resist member.
The cured product of this embodiment is preferably obtained by curing a curable resin composition by irradiating it with active energy rays.

Examples of the active energy ray include ionizing radiation such as ultraviolet rays, electron beams, α rays, β rays, and γ rays. Furthermore, when ultraviolet rays are used as the active energy rays, in order to efficiently perform the curing reaction by ultraviolet rays, the irradiation may be performed in an inert gas atmosphere such as nitrogen gas, or in an air atmosphere.

Examples of sources of ultraviolet light include ultraviolet lamps such as low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, gallium lamps, and metal halide lamps, sunlight, and LEDs. Ultraviolet lamps are commonly used from the viewpoint of performance and economy.

The cumulative light amount of the active energy rays is not particularly limited, but is preferably 0.1 to 50 kJ/m ² , more preferably 0.5 to 10 kJ/m ² . When the cumulative light amount is within the above range, the occurrence of uncured portions can be sufficiently prevented or suppressed. Note that the irradiation with active energy rays may be performed in one step, or may be performed in two or more steps.

Further, as another method for obtaining a cured product by subjecting the curable resin composition to a curing reaction, for example, heat curing can be mentioned. The heating temperature during heat curing is not particularly limited, but it is preferably 100 to 300°C, and the heating time is preferably 1 to 24 hours.

The curable resin composition or cured product of this embodiment is used for circuit boards such as printed wiring board materials, resin compositions for flexible wiring boards, interlayer insulation materials for build-up boards, and adhesive films for build-up. Insulating materials, resin casting materials, adhesives, semiconductor encapsulation materials, semiconductor devices, prepregs, conductive pastes, build-up films, build-up substrates, fiber-reinforced composite materials, molded products made by curing the above composite materials, etc. Can be mentioned. Among these various applications, printed wiring board materials, insulating materials for circuit boards, and build-up adhesive films are used for so-called electronic component embedded substrates in which passive components such as capacitors and active components such as IC chips are embedded within the substrate. It can be used as an insulating material. Furthermore, among the above, the curable resin composition or cured product of this embodiment can be used as a semiconductor encapsulation material, semiconductor device, prepreg, flexible material, etc. by taking advantage of the characteristics that the cured product has excellent heat resistance and coating film appearance. It can be suitably applied to rubble wiring boards, circuit boards, build-up films, build-up boards, multilayer printed wiring boards, fiber-reinforced composite materials, and molded products obtained by curing the composite materials.

<Goods>
The article of this embodiment is characterized by having a coating film made of the above-mentioned cured product. In the article of this embodiment, the coating film has a low elastic modulus, high adhesion to adjacent members, and can function as an insulating material with excellent dielectric properties.

The article of the present embodiment is typically a printed wiring board or a semiconductor package substrate on which a solder resist film (the coating film) is formed at an appropriate location on the surface layer.

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to the Examples below. The descriptions of "parts" and "%" in the examples are based on mass unless otherwise specified. Note that the GPC measurement conditions in this example are as follows.

[GPC measurement conditions]
Measuring device: “HLC-8320 GPC” manufactured by Tosoh Corporation,
Column: Guard column “HXL-L” manufactured by Tosoh Corporation
+ “TSK-GEL G4000HXL” manufactured by Tosoh Corporation
+ “TSK-GEL G3000HXL” manufactured by Tosoh Corporation
+ “TSK-GEL G2000HXL” manufactured by Tosoh Corporation
+ “TSK-GEL G2000HXL” manufactured by Tosoh Corporation
Detector: RI (differential refractometer)
Data processing: “GPC Workstation EcoSEC-WorkStation” manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40℃
Developing solvent Tetrahydrofuran
Flow rate: 1.0 mL/min Standard: In accordance with the measurement manual for "GPC-8320", the following monodisperse polystyrene with a known molecular weight was used.
(Polystyrene used)
"A-500" manufactured by Tosoh Corporation
"A-1000" manufactured by Tosoh Corporation
"A-2500" manufactured by Tosoh Corporation
"A-5000" manufactured by Tosoh Corporation
"F-1" manufactured by Tosoh Corporation
"F-2" manufactured by Tosoh Corporation
"F-4" manufactured by Tosoh Corporation
"F-10" manufactured by Tosoh Corporation
"F-20" manufactured by Tosoh Corporation
"F-40" manufactured by Tosoh Corporation
"F-80" manufactured by Tosoh Corporation
"F-128" manufactured by Tosoh Corporation
Sample: A 1.0% by mass tetrahydrofuran solution (calculated as resin solid content) filtered through a microfilter (50μL)

(Synthesis Example 1: Synthesis of active ester resin (A-1))
In a flask equipped with a thermometer, dropping funnel, cooling tube, fractionating tube, and stirrer, 209 parts by mass of 1-naphthol, 350 parts by mass of toluene, divinylbenzene ("DVB-810" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., divinylbenzene purity) 81% (containing 19% ethylstyrene)) and 1 part by mass of p-toluenesulfonic acid monohydrate were charged. The contents of the flask were heated to 115° C. while stirring, and the mixture was stirred at 115° C. for 1 hour to react. After the reaction was completed, 0.6 parts by mass of a 49% aqueous sodium hydroxide solution was added to neutralize the mixture, 400 parts by mass of toluene was added, and the mixture was washed three times with 200 parts by mass of water. Toluene and the like were distilled off under heating and reduced pressure conditions to obtain 250 parts by mass of a mixture (M-1) containing unreacted 1-naphthol and a phenolic hydroxyl group-containing resin. The hydroxyl equivalent of the obtained mixture (M-1) was 177 g/equivalent, and the number of moles of hydroxyl groups in unreacted 1-naphthol (a1 _OH ) and the number of moles of hydroxyl groups in the phenolic hydroxyl group-containing resin (a2 _OH ) [(a1 _OH )/(a2 _OH )] was 1.45/1.41.
Next, 147 parts by mass of isophthalic acid chloride and 1000 parts by mass of toluene were charged into a flask equipped with a thermometer, a dropping funnel, a condenser tube, a fractionator tube, and a stirrer, and the mixture was dissolved while purging the system with nitrogen under reduced pressure. Next, 250 parts by mass of the mixture (M-1) obtained above was charged and dissolved while purging the system with nitrogen under reduced pressure. Here, the number of moles of hydroxyl groups in the mixture (M-1) is 0.98 moles per mole of acid halide groups that isophthalic acid chloride has. 0.5 g of tetrabutylammonium bromide was added, and 299 parts by mass of a 20% aqueous sodium hydroxide solution was added dropwise over 3 hours while controlling the inside of the reaction system to 60° C. or lower while purging with nitrogen gas. After the dropwise addition was completed, stirring was continued for 1 hour to allow reaction. After the reaction was completed, the reaction mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. After adding water to the remaining organic layer and stirring and mixing for about 15 minutes, the mixture was allowed to stand to separate the layers, and the aqueous layer was removed. After repeating this operation until the pH of the aqueous layer became 7, toluene and the like were distilled off under heating and reduced pressure conditions to obtain 320 parts by mass of active ester resin (A-1). The functional group equivalent of the active ester resin (A-1) was 241 g/equivalent, and the softening point measured based on JIS K7234 was 130°C. The weight average molecular weight (Mw) of the active ester resin (A-1) calculated from the area ratio of the GPC chart was 1236.

(Synthesis Example 2: Synthesis of active ester resin (A-2))
In a flask equipped with a thermometer, dropping funnel, cooling tube, fractionating tube, and stirrer, 200 parts by mass of 1-naphthol, 350 parts by mass of toluene, divinylbenzene ("DVB-960" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., divinylbenzene purity) 96% (containing 4% ethylstyrene) and 1 part by mass of para-toluenesulfonic acid monohydrate were charged. The contents of the flask were heated to 115° C. while stirring, and the mixture was stirred at 115° C. for 1 hour to react. After the reaction was completed, 0.6 parts by mass of a 49% aqueous sodium hydroxide solution was added to neutralize the mixture, 400 parts by mass of toluene was added, and the mixture was washed three times with 200 parts by mass of water. Toluene and the like were distilled off under heating and reduced pressure conditions to obtain 254 parts by mass of a mixture (M-2) containing unreacted 1-naphthol and a phenolic hydroxyl group-containing resin. The hydroxyl equivalent of the obtained mixture (M-2) was 187 g/equivalent, and the number of moles of hydroxyl groups in unreacted 1-naphthol (a1 _OH ) and the number of moles of hydroxyl groups in the phenolic hydroxyl group-containing resin (a2 _OH ) [(a1 _OH )/(a2 _OH )] was 1.39/1.36.
Next, 140 parts by mass of isophthalic acid chloride and 1000 parts by mass of toluene were charged into a flask equipped with a thermometer, dropping funnel, condenser tube, fractionator tube, and stirrer, and dissolved while purging the system with nitrogen under reduced pressure. Next, 254 parts by mass of the mixture (M-2) obtained above was charged and dissolved while purging the system with nitrogen under reduced pressure. Here, the number of moles of hydroxyl groups in the mixture (M-2) is 0.98 moles per mole of acid halide groups that isophthalic acid chloride has. 0.5 g of tetrabutylammonium bromide was added, and 286 parts by mass of a 20% aqueous sodium hydroxide solution was added dropwise over 3 hours while controlling the inside of the reaction system to 60° C. or lower while purging with nitrogen gas. After the dropwise addition was completed, stirring was continued for 1 hour to allow reaction. After the reaction was completed, the reaction mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. After adding water to the remaining organic layer and stirring and mixing for about 15 minutes, the mixture was allowed to stand to separate the layers, and the aqueous layer was removed. After repeating this operation until the pH of the aqueous layer reached 7, toluene and the like were distilled off under heating and reduced pressure conditions to obtain 320 parts by mass of active ester resin (A-2). The functional group equivalent of the active ester resin (A-2) was 252 g/equivalent, and the softening point measured based on JIS K7234 was 165°C. The weight average molecular weight (Mw) of the active ester resin (A-2) calculated from the area ratio of the GPC chart was 2,772.

(Synthesis Example 3: Synthesis of active ester resin (A-3))
In a flask equipped with a thermometer, dropping funnel, cooling tube, fractionating tube, and stirrer, 200 parts by mass of 1-naphthol, 350 parts by mass of toluene, divinylbenzene ("DVB-960" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., divinylbenzene purity) 96% (containing 4% ethylstyrene)) and 1 part by mass of para-toluenesulfonic acid monohydrate were charged. The contents of the flask were heated to 115° C. while stirring, and the mixture was stirred at 115° C. for 1 hour to react. After the reaction was completed, 0.6 parts by mass of a 49% aqueous sodium hydroxide solution was added to neutralize the mixture, 400 parts by mass of toluene was added, and the mixture was washed three times with 200 parts by mass of water. Toluene and the like were distilled off under heating and reduced pressure conditions to obtain 245 parts by mass of a mixture (M-3) containing unreacted 1-naphthol and a phenolic hydroxyl group-containing resin. The hydroxyl equivalent of the obtained mixture (M-3) was 181 g/equivalent, and the number of moles of hydroxyl groups in unreacted 1-naphthol (a1 _OH ) and the number of moles of hydroxyl groups in the phenolic hydroxyl group-containing resin (a2 _OH ) [(a1 _OH )/(a2 _OH )] was 1.39/1.35.
Next, 140 parts by mass of isophthalic acid chloride and 1000 parts by mass of toluene were charged into a flask equipped with a thermometer, dropping funnel, condenser tube, fractionator tube, and stirrer, and dissolved while purging the system with nitrogen under reduced pressure. Next, 245 parts by mass of the mixture (M-3) obtained above was charged and dissolved while purging the system with nitrogen under reduced pressure. Here, the number of moles of hydroxyl groups in the mixture (M-3) is 0.98 moles per mole of acid halide groups that isophthalic acid chloride has. 0.5 g of tetrabutylammonium bromide was added, and 286 parts by mass of a 20% aqueous sodium hydroxide solution was added dropwise over 3 hours while controlling the inside of the reaction system to 60° C. or lower while purging with nitrogen gas. After the dropwise addition was completed, stirring was continued for 1 hour to allow reaction. After the reaction was completed, the reaction mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. After adding water to the remaining organic layer and stirring and mixing for about 15 minutes, the mixture was allowed to stand to separate the layers, and the aqueous layer was removed. After repeating this operation until the pH of the aqueous layer became 7, toluene and the like were distilled off under heating and reduced pressure conditions to obtain 312 parts by mass of active ester resin (A-3). The functional group equivalent of the active ester resin (A-3) was 245 g/equivalent, and the softening point measured based on JIS K7234 was 150°C. The weight average molecular weight (Mw) of the active ester resin (A-3) calculated from the area ratio of the GPC chart was 1377.

(Synthesis Example 4: Synthesis of active ester resin (A-4))
In a flask equipped with a thermometer, dropping funnel, cooling tube, fractionating tube, and stirrer, 255 parts by mass of orthophenylphenol, 400 parts by mass of toluene, divinylbenzene ("DVB-810" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., divinylbenzene purity) 81% (containing 19% ethylstyrene) and 1 part by mass of para-toluenesulfonic acid monohydrate were charged. The contents of the flask were heated to 115° C. while stirring, and the mixture was stirred at 115° C. for 1 hour to react. After the reaction was completed, 0.6 parts by mass of a 49% aqueous sodium hydroxide solution was added to neutralize the mixture, 400 parts by mass of toluene was added, and the mixture was washed three times with 200 parts by mass of water. Toluene and the like were distilled off under heating and reduced pressure conditions to obtain 295 parts by mass of a mixture (M-4) containing unreacted orthophenylphenol and a phenolic hydroxyl group-containing resin. The hydroxyl equivalent of the obtained mixture (M-4) was 203 g/equivalent, and the number of moles of hydroxyl groups possessed by unreacted orthophenylphenol (a1 _OH ) and the number of moles of hydroxyl groups possessed by the phenolic hydroxyl group-containing resin (a2 _OH ) [(a1 _OH )/(a2 _OH )] was 1.50/1.45.
Next, 151 parts by mass of isophthalic acid chloride and 800 parts by mass of toluene were charged into a flask equipped with a thermometer, a dropping funnel, a cooling tube, a fractionating tube, and a stirrer, and the mixture was dissolved while purging the system with nitrogen under reduced pressure. Next, 295 parts by mass of the mixture (M-4) obtained above was charged and dissolved while purging the system with nitrogen under reduced pressure. Here, the number of moles of hydroxyl groups in the mixture (M-4) is 0.98 moles per mole of acid halide groups that isophthalic acid chloride has. 0.5 g of tetrabutylammonium bromide was added, and 308 parts by mass of a 20% aqueous sodium hydroxide solution was added dropwise over 3 hours while controlling the inside of the reaction system to 60° C. or lower while purging with nitrogen gas. After the dropwise addition was completed, stirring was continued for 1 hour to allow reaction. After the reaction was completed, the reaction mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. After adding water to the remaining organic layer and stirring and mixing for about 15 minutes, the mixture was allowed to stand to separate the layers, and the aqueous layer was removed. After repeating this operation until the pH of the aqueous layer reached 7, toluene and the like were distilled off under heating and reduced pressure conditions to obtain 365 parts by mass of active ester resin (A-4). The functional group equivalent of the active ester resin (A-4) was 267 g/equivalent, and the softening point measured based on JIS K7234 was 94°C. The weight average molecular weight (Mw) of the active ester resin (A-4) calculated from the area ratio of the GPC chart was 1181.

(Synthesis Example 5: Synthesis of active ester resin (A-5))
In a flask equipped with a thermometer, dropping funnel, cooling tube, fractionating tube, and stirrer, 245 parts by mass of orthophenylphenol, 400 parts by mass of toluene, divinylbenzene ("DVB-810" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., divinylbenzene purity) 81% (containing 19% ethylstyrene) and 1 part by mass of para-toluenesulfonic acid monohydrate were charged. The contents of the flask were heated to 115° C. while stirring, and the mixture was stirred at 115° C. for 1 hour to react. After the reaction was completed, 0.6 parts by mass of a 49% aqueous sodium hydroxide solution was added to neutralize the mixture, 400 parts by mass of toluene was added, and the mixture was washed three times with 200 parts by mass of water. Toluene and the like were distilled off under heating and reduced pressure conditions to obtain 300 parts by mass of a mixture (M-5) containing unreacted orthophenylphenol and a phenolic hydroxyl group-containing resin. The hydroxyl equivalent of the obtained mixture (M-5) was 213 g/equivalent, and the number of moles of hydroxyl groups possessed by unreacted orthophenylphenol (a1 _OH ) and the number of moles of hydroxyl groups possessed by the phenolic hydroxyl group-containing resin (a2 _OH ) [(a1 _OH )/(a2 _OH )] was 1.44/1.41.
Next, 145 parts by mass of isophthalic acid chloride and 800 parts by mass of toluene were charged into a flask equipped with a thermometer, a dropping funnel, a cooling tube, a fractionating tube, and a stirrer, and the mixture was dissolved while purging the system with nitrogen under reduced pressure. Next, 300 parts by mass of the mixture (M-5) obtained above was charged and dissolved while purging the system with nitrogen under reduced pressure. Here, the number of moles of hydroxyl groups in the mixture (M-5) is 0.99 moles per 1 mole of acid halide groups that isophthalic acid chloride has. 0.5 g of tetrabutylammonium bromide was added, and 297 parts by mass of a 20% aqueous sodium hydroxide solution was added dropwise over 3 hours while controlling the inside of the reaction system to 60° C. or lower while purging with nitrogen gas. After the dropwise addition was completed, stirring was continued for 1 hour to allow reaction. After the reaction was completed, the reaction mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. After adding water to the remaining organic layer and stirring and mixing for about 15 minutes, the mixture was allowed to stand to separate the layers, and the aqueous layer was removed. After repeating this operation until the pH of the aqueous layer became 7, toluene and the like were distilled off under heating and reduced pressure conditions to obtain 365 parts by mass of active ester resin (A-5). The functional group equivalent of the active ester resin (A-5) was 278 g/equivalent, and the softening point measured based on JIS K7234 was 102°C. The weight average molecular weight (Mw) of the active ester resin (A-5) calculated from the area ratio of the GPC chart was 1795.

(Synthesis Example 6: Production of active ester resin (C-1))
In a flask equipped with a thermometer, dropping funnel, cooling tube, fractionating tube, and stirrer, 165 parts by mass of an addition reaction product of dicyclopentadiene and phenol (hydroxyl equivalent: 165 g/equivalent, softening point: 85°C), 1-naphthol. 72 parts by mass and 630 parts by mass of toluene were charged and dissolved while purging the system with nitrogen under reduced pressure. Next, 152 parts by mass of isophthaloyl chloride was charged and dissolved while purging the system with nitrogen under reduced pressure. While purging with nitrogen gas, the inside of the system was controlled at 60° C. or lower, and 300 parts by mass of a 20% aqueous sodium hydroxide solution was added dropwise over 3 hours. After the dropwise addition was completed, stirring was continued for 1 hour to allow reaction. After the reaction was completed, the reaction mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. After adding water to the remaining organic layer and stirring and mixing for about 15 minutes, the mixture was allowed to stand to separate the layers, and the aqueous layer was removed. After repeating this operation until the pH of the aqueous layer reached 7, toluene and the like were distilled off under heating and reduced pressure conditions to obtain active ester resin (C-1). The functional group equivalent of the active ester resin (C-1) was 223 g/equivalent, and the softening point measured based on JIS K7234 was 150°C.

(Synthesis Example 7: Production of resin (B-1) having a polymerizable unsaturated group)
A flask equipped with a thermometer, a stirrer, and a reflux condenser was charged with 188 parts by mass of bisphenol A epoxy resin ("EPICLON 850-S" manufactured by DIC Corporation, epoxy equivalent: 188 g/equivalent), and 0.0 parts by mass of dibutylhydroxytoluene was charged. After adding 3 parts by mass and 0.1 parts by mass of methoquinone as a thermal polymerization inhibitor, 72 parts by mass of acrylic acid and 1.3 parts by mass of triphenylphosphine were added, and the reaction was carried out at 120°C for 8 hours while blowing air. A resin (B-1) having a polymerizable unsaturated group was obtained.

(Synthesis Example 8: Production of epoxy resin (B-2) having a polymerizable unsaturated group)
A flask equipped with a thermometer, a stirrer, and a reflux condenser was charged with 346 parts by mass of a bisphenol A epoxy resin ("EPICLON 850CRP" manufactured by DIC Corporation, epoxy equivalent: 173 g/eq), and dibutylhydroxytoluene was added as an antioxidant. After adding 0.21 parts by mass and 0.21 parts by mass of methoquinone as a thermal polymerization inhibitor, 72 parts by mass of acrylic acid and 0.21 parts by mass of triphenylphosphine were added and esterified at 100°C for 10 hours while blowing air. The reaction was carried out. Next, after confirming that the acid value was 1 mgKOH/g or less, 0.21 parts by mass of oxalic acid was added and stirred at 70°C for 3 hours to prepare an epoxy resin (B-2) having a polymerizable unsaturated group. I got it. The epoxy equivalent of this resin (B-2) was 450 g/eq.

(Examples 1 to 6, Comparative Example 1)
Each component was mixed in the proportions shown in Table 1 below to obtain curable resin compositions (1) to (6) and (C1). The following tests were conducted on the obtained curable resin composition.

[Method of measuring elastic modulus]
The curable resin compositions obtained in Examples and Comparative Examples were applied onto copper foil (manufactured by Furukawa Sangyo Co., Ltd., electrolytic copper foil "F2-WS" 18 μm) using a 50 μm applicator, and then heated at 10 kJ/cm using a metal halide lamp. After irradiating with m ² of ultraviolet light, it was heated at 160° C. for 1 hour. The cured product was peeled off from the copper foil to obtain test piece 1 (cured product). Using this test piece 1, the elastic modulus (MPa) was measured under the condition of 2 mm/min in accordance with JIS K7181. The smaller the value, the lower the elasticity.

[Adhesion evaluation method]
Adhesion was evaluated by measuring peel strength. Specifically, the curable resin compositions obtained in Examples and Comparative Examples were applied onto copper foil (manufactured by Furukawa Sangyo Co., Ltd., electrolytic copper foil "F2-WS" 18 μm) using a 50 μm applicator, and a metal halide lamp was applied. After irradiating with 10 kJ/m ² of ultraviolet rays using a 10 kJ/m 2 ultraviolet ray, the sample was heated at 160° C. for 1 hour to obtain a test piece 2 (cured product). This test piece 2 was cut out to a size of 1 cm wide and 12 cm long, and the 90° peel strength (N/cm) was measured using a peel tester (“A&D Tensilon” manufactured by A&D Co., Ltd., peeling speed 50 mm/min). It was measured. The larger the value, the better the adhesion.

[Measurement method of dielectric constant]
The curable resin compositions obtained in each example and comparative example were applied onto a glass substrate using an applicator to a film thickness of 50 μm, and dried at 80° C. for 30 minutes. Next, after irradiating with ultraviolet rays of 10 kJ/m ² using a metal halide lamp, the film was heated at 160° C. for 1 hour to obtain a cured coating film. Next, the cured coating film was peeled off from the glass substrate to obtain a cured product. Next, the test piece was stored in a room at a temperature of 23°C and a humidity of 50% for 24 hours, and the permittivity of the test piece at 1 GHz was determined by the cavity resonance method using "Network Analyzer E8362C" manufactured by Agilent Technologies. It was measured.

[Measurement method of dielectric loss tangent]
The curable resin compositions obtained in each example and comparative example were applied onto a glass substrate using an applicator to a film thickness of 50 μm, and dried at 80° C. for 30 minutes. Next, after irradiating with ultraviolet rays of 10 kJ/m ² using a metal halide lamp, the film was heated at 160° C. for 1 hour to obtain a cured coating film. Next, the cured coating film was peeled off from the glass substrate to obtain a cured product. Next, the test piece was stored in a room at a temperature of 23°C and a humidity of 50% for 24 hours, and the dielectric loss tangent of the test piece at 1 GHz was measured using the cavity resonance method using "Network Analyzer E8362C" manufactured by Agilent Technologies. It was measured.

*1 Active ester resin (A-1): Active ester resin obtained in Synthesis Example 1, active ester resin using divinyl compound (a2-2) as a reaction raw material and phenolic hydroxyl group-containing resin (a2) as a reaction raw material, Nonvolatile content (solid content) = 100% by mass
*2 Active ester resin (A-2): Active ester resin obtained in Synthesis Example 2, active ester resin using divinyl compound (a2-2) as a reaction raw material and phenolic hydroxyl group-containing resin (a2) as a reaction raw material, Nonvolatile content (solid content) = 100% by mass
*3 Active ester resin (A-3): Active ester resin obtained in Synthesis Example 3, active ester resin using divinyl compound (a2-2) as a reaction raw material and phenolic hydroxyl group-containing resin (a2) as a reaction raw material, Nonvolatile content (solid content) = 100% by mass
*4 Active ester resin (A-4): Active ester resin obtained in Synthesis Example 4, active ester resin using divinyl compound (a2-2) as a reaction raw material and phenolic hydroxyl group-containing resin (a2) as a reaction raw material, Nonvolatile content (solid content) = 100% by mass
*5 Active ester resin (A-5): Active ester resin obtained in Synthesis Example 5, active ester resin using divinyl compound (a2-2) as a reaction raw material and phenolic hydroxyl group-containing resin (a2) as a reaction raw material, Nonvolatile content (solid content) = 100% by mass
*6 Active ester resin (C-1): Active ester resin obtained in Synthesis Example 6, active ester resin that uses divinyl compound (a2-2) as a reaction raw material but does not use phenolic hydroxyl group-containing resin (a2) as a reaction raw material, Nonvolatile content (solid content) = 100% by mass
*7 Resin having a polymerizable unsaturated group (B-1): Resin having a polymerizable unsaturated group obtained in Synthesis Example 7, epoxy resin having a polymerizable unsaturated group, nonvolatile content (solid content) = 100 mass %
*8 Resin having a polymerizable unsaturated group (B-2): Resin having a polymerizable unsaturated group obtained in Synthesis Example 8, epoxy resin having a polymerizable unsaturated group, nonvolatile content (solid content) = 100 mass %
*9 Organic solvent: Diethylene glycol monoethyl ether acetate *10 Photopolymerization initiator: Manufactured by IGM Resins, trade name "Omnirad 907"

From Table 1, it can be seen that the cured products obtained by curing the curable resin compositions of Examples 1 to 6 according to the present invention reacted with the phenolic hydroxyl group-containing resin (a2) using the divinyl compound (a2-2) as a reaction raw material. It can be seen that the cured product of Comparative Example 1 using an active ester resin not used as a raw material has a lower elastic modulus, higher adhesion, and excellent dielectric properties (lower permittivity and dielectric loss tangent).

The curable resin composition and cured product of the present invention can be used for various articles such as printed wiring boards and semiconductor package substrates.

Claims (8)

Contains an active ester resin (A) and a resin (B) having a polymerizable unsaturated group,
The active ester resin (A) contains a compound (a1) having one phenolic hydroxyl group in its molecular structure, a phenolic hydroxyl group-containing compound (a2-1), and a divinyl compound (a2-2) as essential reaction raw materials. A curable resin composition comprising a phenolic hydroxyl group-containing resin (a2) and an aromatic polycarboxylic acid or its acid halide (a3) as essential reaction raw materials. The ratio between the number of moles of hydroxyl groups (a1 _OH ) possessed by the compound (a1) having one phenolic hydroxyl group in the molecular structure and the number of moles (a2 OH ) of hydroxyl groups possessed by the phenolic hydroxyl group-containing resin ( _a2 ) [ The curable resin composition according to claim 1, wherein (a1 _OH )/(a2 _OH )] is 10/90 to 75/25. The total number of moles of hydroxyl groups (a1 _OH ) possessed by the compound (a1) having one phenolic hydroxyl group in the molecular structure and the number of moles (a2 _OH ) of hydroxyl groups possessed by the phenolic hydroxyl group-containing resin (a2) is , the curability according to claim 1, which is 0.95 to 1.05 mol per 1 mol of carboxyl groups or acid halide groups in the aromatic polycarboxylic acid or its acid halide (a3). Resin composition. The curable resin composition according to claim 1, wherein the active ester resin (A) has a weight average molecular weight (Mw) of 600 to 5,000. A solid content mass ratio [(A)/(B)] of the active ester resin (A) and the polymerizable unsaturated group-containing resin (B) is 5/95 to 50/50. 1. The curable resin composition according to 1. The curable resin composition according to claim 1, further comprising a photopolymerization initiator. A cured product obtained by curing the curable resin composition according to any one of claims 1 to 6. An article comprising a coating film made of the cured product according to claim 7.