JP7739870B2 - Resin composition having polymerizable unsaturated group, curable resin composition, cured product, and article - Google Patents

Description

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

When mounting and soldering electronic components on a printed wiring board, solder resist is widely used as an insulating material to prevent solder from adhering to areas other than the mounted area and to form a coating that semi-permanently prevents oxidation or corrosion of the wiring. One technique for forming such solder resist patterns is the photoresist method, which allows for the accurate formation of fine patterns. Of these, the alkaline-developable liquid photoresist method is the most popular due to environmental considerations, among other factors.

For example, Patent Document 1 discloses a photosensitive resin composition containing an active ester curing agent and a carboxyl group-containing radical polymerizable compound as a material used in an alkali-developable photoresist method.

JP 2013-214057 A

Recently, a new method for forming solder resist films using an inkjet method has been proposed. This method does not require the development process required for the alkaline development method described above, making it possible to reduce the number of steps, time, and consumables.

However, if the viscosity of the ink used in the inkjet method decreases, the physical properties required for the solder resist film, such as heat resistance and chemical resistance, tend to deteriorate significantly. For this reason, it is important that the ink used in the inkjet method has low viscosity and does not thicken. As a material (oligomer) compatible with the inkjet method, epoxy acrylate, which is made by partially acrylated epoxy resin and can be cured by ultraviolet light or heat, has been proposed.

However, the epoxy acrylates mentioned above contain hydroxyl groups generated by the acrylate conversion of epoxy resins, which increases their dielectric constant, making it difficult to deploy them in high-frequency applications when used alone.

In addition, solder resist films are required to have excellent adhesion to wiring or substrates, low elasticity, and flexibility (elongation) in order to prevent defects such as cracking and peeling.

The present invention therefore aims to provide a resin composition that can be used to obtain insulating materials with excellent adhesion, low elasticity, dielectric properties, and elongation. It also aims to provide a curable resin composition containing such a resin composition, a cured product thereof, and an article using such a cured product.

The inventors conducted extensive research to solve the above-mentioned problems and discovered that by using a composition containing a specific aromatic ester compound and an epoxy resin having a specific polymerizable unsaturated group, the resulting cured product exhibits excellent dielectric properties, elongation, adhesion, and low elasticity, leading to the completion of the present invention.

The resin composition of the present invention is a resin composition having a polymerizable unsaturated group, which contains an aromatic ester compound (A) and an epoxy resin (B) having a polymerizable unsaturated group,
the aromatic ester compound (A) is a compound obtained by reacting an aromatic polycarboxylic acid, an acid halide thereof, and/or an ester thereof (a1), a monohydroxyaromatic compound (a2), and a polyhydric alcohol compound (a3) as essential reaction raw materials;
the hydroxyl group equivalent of the polyhydric alcohol compound (a3) is 270 g/eq or more,
the epoxy resin (B) having a polymerizable unsaturated group is a resin containing an epoxy resin (b1) and an unsaturated monobasic acid (b2) as essential reaction raw materials;
It is characterized by:

In this embodiment, the aromatic ester compound (A) is represented by the following general formula (1):
[In the above general formula (1), ^Q11 and ^Q12 each independently represent a group derived from the aromatic polycarboxylic acid, its acid halide and/or its ester (a1), ^Ar11 and ^Ar12 each independently represent a group derived from the monohydroxy aromatic compound (a2), A each independently represent a group derived from the polyhydric alcohol compound (a3), and ^p11 represents an average repeat number of 0.01 or more.]

In this embodiment, in the general formula (1), each A independently represents a linear or branched alkylene group, or a linear or branched alkylene ether group,
^Q11 and ^Q12 each independently represent a divalent aromatic group; ^p11 represents an average repeat number of 0.01 or more;
Ar ¹¹ and Ar ¹² each independently represent the following general formula (2) or (3):
[In the general formula (2) and the general formula (3), * represents a bond to the oxygen atom bonding to Ar ¹¹ or Ar ¹² in the general formula (1),
R ²¹ and R ³¹ each independently represent a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, or an aralkyl group, k ²¹ represents an integer of 0 to 7, and k ³¹ represents an integer of 0 to 5.

The present invention provides a resin composition that can be used to obtain an insulating material with excellent adhesion, low elasticity, dielectric properties, and elongation. The present invention also provides a curable resin composition containing such a resin composition, a cured product thereof, and an article using such a cured product.

1 is a GPC chart of the diphenyl isophthalate derivative (a'-1) obtained in the example.

The following describes in detail an embodiment of the present invention (sometimes referred to as the "present embodiment"); however, the present invention is not limited to the following description and can be implemented in various modifications within the scope of its gist.

[Resin composition having a polymerizable unsaturated group]
The resin composition having a polymerizable unsaturated group of this embodiment is a resin composition having a polymerizable unsaturated group, which contains an aromatic ester compound (A) (hereinafter also referred to as component (A)) and an epoxy resin (B) having a polymerizable unsaturated group (hereinafter also referred to as component (B)). The aromatic ester compound (A) is a compound containing, as essential reaction raw materials, an aromatic polycarboxylic acid, its acid halide and/or its ester (a1), a monohydroxyaromatic compound (a2), and a polyhydric alcohol compound (a3). The hydroxyl group equivalent of the polyhydric alcohol compound (a3) is 270 g/eq or more. The epoxy resin (B) having a polymerizable unsaturated group is a resin containing, as essential reaction raw materials, an epoxy resin (b1) and an unsaturated monobasic acid (b2).
By using such a resin composition having a polymerizable unsaturated group, it is possible to obtain an insulating material having excellent adhesion, low elasticity, excellent dielectric properties and excellent elongation.

The content of the aromatic ester compound (A) in the total amount (100% by mass) of the resin composition having a polymerizable unsaturated group of the present embodiment is, from the viewpoint of improving adhesion, low elasticity, dielectric properties, and elongation in a balanced manner, preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, and is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less.
From the viewpoint of improving adhesion, low elasticity, dielectric properties, and elongation in a balanced manner, the content of the epoxy resin (B) having a polymerizable unsaturated group in the total amount (100% by mass) of the resin composition having a polymerizable unsaturated group of the present embodiment is preferably 20% by mass or more, more preferably 40% by mass or more, and even more preferably 50% by mass or more, and is preferably 99% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less.

In the resin composition having a polymerizable unsaturated group of this embodiment, the mass ratio of the solids of the aromatic ester compound (A) to the epoxy resin (B) having a polymerizable unsaturated group [(A)/(B)] is preferably in the range of 10/90 to 90/10, from the viewpoint of achieving a balanced improvement in adhesion, low elasticity, dielectric properties, and elongation. From the same viewpoint, the mass ratio [(A)/(B)] is more preferably 10/90 or more, and more preferably 40/60 or less.

The resin composition having a polymerizable unsaturated group of this embodiment may further contain an optional additional component as an optional component. Furthermore, the resin composition having a polymerizable unsaturated group of this embodiment may be substantially composed of only the component (A), the component (B), and the optional additional component. The resin composition having a polymerizable unsaturated group of this embodiment may be composed of only the component (A) and the component (B). The resin composition having a polymerizable unsaturated group of this embodiment may contain inevitable impurities in addition to the component (A), the component (B), and the optional additional component, as long as the effects of the present disclosure are not impaired.
From the viewpoint of improving adhesion, low elasticity, dielectric properties, and elongation in a balanced manner, the total content of the (A) component and the (B) component in the total amount (100% by mass) of the resin composition having a polymerizable unsaturated group of the present embodiment is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 40% by mass or more, and is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less.

Below, we will explain the main terms used in this specification, followed by an explanation of the components contained in the resin composition having a polymerizable unsaturated group of this embodiment: the aromatic ester compound (A), the epoxy resin having a polymerizable unsaturated group (B), and the optional additional components.

(Explanation of terms)
Unless otherwise specified herein, the following terms apply.

The "aromatic group" referred to herein preferably has an aromatic ring having 3 to 30 carbon atoms. Furthermore, the "aromatic group" referred to herein may have a hydrogen atom in the aromatic ring substituted with a substituent, such as an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a halogen atom.

Examples of the aromatic ring include a monocyclic aromatic ring, a fused aromatic ring, and an agglomerated aromatic ring. Examples of the monocyclic aromatic ring include benzene, furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, isothiazole, pyridine, pyrimidine, pyridazine, pyrazine, and triazine. Examples of the fused aromatic ring include naphthalene, anthracene, phenalene, phenanthrene, quinoline, isoquinoline, quinazoline, phthalazine, pteridine, coumarin, indole, benzimidazole, benzofuran, and acridine. Examples of the agglomerated aromatic ring include biphenyl, binaphthalene, bipyridine, bithiophene, phenylpyridine, phenylthiophene, terphenyl, diphenylthiophene, and quaterphenyl.

A monovalent aromatic group refers to a group in which one hydrogen atom has been removed from an "aromatic group," a divalent aromatic group refers to a group in which two hydrogen atoms have been removed from an "aromatic group," and a trivalent to hexavalent aromatic group refers to a group in which three to six hydrogen atoms have been removed from an "aromatic group."

As used herein, "aryl groups" include, for example, phenyl groups, naphthyl groups, phenalenyl groups, phenanthrenyl groups, anthryl groups, azulenyl groups, indenyl groups, indanyl groups, and tetralinyl groups. Furthermore, the hydrogen atoms of the aromatic rings in the "aryl groups" may be substituted with, for example, alkyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 10 carbon atoms, or halogen atoms.

As used herein, "aralkyl groups" include, for example, benzyl groups, diphenylmethyl groups, biphenyl groups, and naphthylmethyl groups.

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

As used herein, "alkenyl groups" include ethynyl groups, 1-propynyl groups, 2-propynyl groups, 2-butynyl groups, pentynyl groups, hexynyl groups, vinyl groups, allyl groups, and isopropenyl groups.

As used herein, "alkoxy groups" include, for example, methoxy groups, ethoxy groups, propoxy groups, isopropoxy groups, butoxy groups, pentyloxy groups, hexyloxy groups, 2-ethylhexyloxy groups, octyloxy groups, and nonyloxy groups.

As used herein, "halogen atom" includes, for example, fluorine atom, chlorine atom, bromine atom, iodine atom, etc.

As used herein, "linear or branched alkylene groups" include, for example, methylene, ethylene, propylene, 1-methylmethylene, 1,1-dimethylmethylene, 1-methylethylene, 1,1-dimethylethylene, 1,2-dimethylethylene, propylene, butylene, 1-methylpropylene, 2-methylpropylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, and dodecylene groups.

As used herein, "linear or branched alkylene ether group" includes, for example, an oxymethylene group, an oxypropylene group, an oxy(1-methylmethylene) group, an oxy(1,1-dimethylmethylene) group, an oxy(1-methylethylene) group, an oxy(1,1-dimethylethylene) group, an oxy(1,2-dimethylethylene) group, an oxybutylene group, an oxy(1-methylpropylene) group, an oxy(2-methylpropylene) group, an oxypentylene group, an oxyhexylene group, an oxyheptylene group, an oxyoctylene group, an oxynonylene group, an oxydecylene group, an oxyundecylene group, and an oxydodecylene group.

The "monovalent hydrocarbon group" in this specification refers to an alkyl group (for example, the alkyl groups described above), in which one or more -CH ₂ - groups may be substituted with -O- or -S- so that they are not adjacent to each other, or one or more -CH ₂ -CH ₂ - groups may be substituted with -CH═CH- so that they are not adjacent to each other. The hydrocarbon group may be linear or branched, and may be an alkyl group having 1 to 20 carbon atoms.

The "divalent hydrocarbon group" in this specification refers to an alkylene group (for example, the above-mentioned straight-chain or branched-chain alkylene group), in which one or more -CH ₂ - groups may be substituted with -O- or -S- so that they are not adjacent to each other, or one or more -CH ₂ -CH ₂ - groups may be substituted with -CH═CH- so that they are not adjacent to each other. The hydrocarbon group may be straight-chain or branched, and may be an alkylene group having 1 to 20 carbon atoms.

The term "trivalent to hexavalent hydrocarbon group" as used herein refers to an alkyl group (for example, the above-mentioned linear or branched alkyl group) in which two to five hydrogen atoms have been removed from any position, and in which one or more -CH ₂ - groups in the alkyl group may be substituted with -O- or -S- so that they are not adjacent to each other, or one or more -CH ₂ -CH ₂ - groups in the alkyl group may be substituted with -CH═CH- so that they are not adjacent to each other. The hydrocarbon group may be linear or branched and may have 1 to 20 carbon atoms.

In this specification, "(meth)acrylate" means acrylate and/or methacrylate. Also, in this specification, "(meth)acryloyl" means acryloyl and/or methacryloyl. Furthermore, in this specification, "(meth)acrylic" means acrylic and/or methacrylic.

(Aromatic ester compound (A))
The aromatic ester compound (A) is one of the essential components of the resin composition having a polymerizable unsaturated group of this embodiment, and is obtained from an aromatic polycarboxylic acid, its acid halide and/or its ester (a1), a monohydroxyaromatic compound (a2), and a polyhydric alcohol compound (a3) as essential reaction raw materials.
The reaction raw material may further contain a compound (e.g., a polyhydroxy aromatic compound (a4)) that is reactive with the aromatic polycarboxylic acid, its acid halide and/or its ester (a1), or the monohydroxy aromatic compound (a2). That is, the aromatic ester compound (A) of this embodiment may be a compound used as a reaction raw material that contains the aromatic polycarboxylic acid, its acid halide and/or its ester (a1), the monohydroxy aromatic compound (a2), the polyhydric alcohol compound (a3), and the polyhydroxy aromatic compound (a4).
In principle, the aromatic ester compound (A) obtained from the reaction raw materials has no or almost no hydroxyl groups in the molecule, but the aromatic ester compound (A) may contain a compound having a hydroxyl group as a by-product of the reaction product, within a range that does not impair the effects of the present disclosure.

In this specification, "aromatic polycarboxylic acids, their acid halides, and/or their esters (a1)" may be abbreviated as "aromatic polycarboxylic acids (a1)" hereinafter.

Before describing the reaction raw materials, aromatic polycarboxylic acids (a1), monohydroxyaromatic compounds (a2), and polyhydric alcohol compounds (a3), the structure and properties of aromatic ester compound (A) will be described in detail below.

<Structure of aromatic ester compound (A)>
In terms of structure, the aromatic ester compound (A) of the present embodiment can contain a residue of an aromatic polycarboxylic acid, an acid halide thereof, and/or an ester thereof (aromatic polycarboxylic acids) (a1), a residue of a monohydroxyaromatic compound (a2), and a residue of a polyhydric alcohol compound (a3).

From the standpoint of another structure, the aromatic ester compound (A) of this embodiment can contain residues of an aromatic polycarboxylic acid, its acid halide, and/or its ester (aromatic polycarboxylic acids) (a1), residues of a monohydroxy aromatic compound (a2), residues of a polyhydric alcohol compound (a3), and residues of a polyhydric hydroxy aromatic compound (a4).

Furthermore, the aromatic ester compound (A) of the present embodiment can have a structure in which an ester bond is formed between a carboxylic acid (or an acid halide or an ester thereof) in the aromatic polycarboxylic acid (a1) and a hydroxyl group in the monohydroxyaromatic compound (a2).
Similarly, the aromatic ester compound (A) of the present embodiment can have a structure in which an ester bond is formed between a carboxylic acid (or an acid halide thereof, or an ester thereof) in the aromatic polycarboxylic acid (a1) and a hydroxyl group in the polyhydric alcohol compound (a3).
Furthermore, the aromatic ester compound (A) of the present embodiment can have a structure in which an ester bond is formed between a carboxylic acid (or an acid halide or an ester thereof) in the aromatic polycarboxylic acid (a1) and a hydroxyl group in the polyhydroxyaromatic compound (a4).

In this specification, the term "aromatic polycarboxylic acid, its acid halide and/or its ester (a1)" refers to a compound having an aromatic group to which two or more atomic groups containing a carbonyl group (-C(=O)-X (X represents a hydrogen atom, a halogen atom, a hydroxyl group, or a monovalent hydrocarbon group)) are bonded.
In this specification, the term "residue of an aromatic polycarboxylic acid, an acid halide thereof, and/or an ester thereof (a1)" refers to a partial structure of the aromatic polycarboxylic acid, an acid halide thereof, and/or an ester thereof (a1) that remains in the molecule of the aromatic ester compound (A) produced by a reaction or polymerization, and is composed of a chemical bond formed by the reaction or polymerization and a group derived from the aromatic polycarboxylic acid, an acid halide thereof, and/or an ester thereof (a1) other than the chemical bond.
Furthermore, in this specification, the term "group derived from" refers to a partial structure other than the structure of the chemical bond involved in the reaction or polymerization in the product compound formed by the reaction or polymerization. Therefore, the term "group derived from the aromatic polycarboxylic acid, its acid halide and/or its ester (a1)" refers to a divalent or higher group obtained by removing an atomic group containing a carbonyl group (-C(=O)-X (X is a hydrogen atom, a halogen atom, a hydroxyl group, or a monovalent hydrocarbon group)) from the aromatic polycarboxylic acid, its acid halide and/or its ester (a1), and may be, for example, a divalent or higher aromatic group.

Aromatic polycarboxylic acids, their acid halides, and/or their esters (a1) are represented by the following general formula (a1):

In this case, Q ^a1 represents a group derived from an aromatic polycarboxylic acid, an acid halide thereof, and/or an ester thereof (a1); X represents a hydrogen atom, a halogen atom, a hydroxyl group, or a monovalent hydrocarbon group; n ^a1 represents an integer of 2 or more and 6 or less; and the dashed line portion represents a residue of an aromatic polycarboxylic acid, an acid halide thereof, and/or an ester thereof (a1).

In this specification, the term "residue of a monohydroxy aromatic compound (a2)" refers to a monovalent group obtained by removing a hydrogen atom or a hydroxyl group from a monohydroxy aromatic compound (a2). The "monohydroxy aromatic compound (a2)" is a compound represented by the following general formula (a2):
In this case, Ar ^a2 represents a group derived from the monohydroxy aromatic compound (a2), i.e., a monovalent group obtained by removing a hydroxy group from the monohydroxy aromatic compound (a2), and the dashed line portion represents a residue of the monohydroxy aromatic compound (a2).

In this specification, the term "residue of polyhydric alcohol compound (a3)" refers to a divalent or higher polyvalent group obtained by removing two or more hydrogen atoms or hydroxyl groups from polyhydric alcohol compound (a3). The "polyhydric alcohol compound (a3)" is represented by the following general formula (a3):
In this case, A ^a3 represents a group derived from the polyhydric alcohol compound (a3), and is an n ^a3 -valent group obtained by removing a hydrogen atom or a hydroxyl group from the polyhydric alcohol compound (a3), and n ^a3 represents an integer of 2 or more and 6 or less. n ^a3 is preferably 2.
The polyhydric hydroxy aromatic compound (a4) is a compound in which only two or more hydrogen atoms in the aromatic ring of the aromatic group are substituted with hydroxyl groups, whereas the polyhydric alcohol compound (a3) is a polyhydric alcohol other than the polyhydric hydroxy aromatic compound (a4).

In this specification, the term "residue of polyhydroxy aromatic compound (a4)" refers to a divalent or higher polyvalent group obtained by removing a hydrogen atom or a hydroxyl group from polyhydroxy aromatic compound (a4). The "polyhydroxy aromatic compound (a4)" is represented by the following general formula (a4):
In this case, Ar ^a4 represents a group derived from the polyvalent hydroxy aromatic compound (a4), and is an n-valent group obtained by removing n ^a4 hydrogen atoms or hydroxyl groups from the polyvalent hydroxy aromatic compound (a4), and n ^a4 represents an integer of 2 to 6. n ^a4 is preferably 2.
The polyvalent hydroxy aromatic compound (a4) is a compound in which only 2 to 6 hydrogen atoms in the aromatic ring of the aromatic group are substituted with hydroxyl groups.

Note that the terms "monovalent" and "divalent" used here simply indicate the number of bonds, and correspond to the number of ester bonds contributed by one molecule of each compound.

The group derived from the aromatic polycarboxylic acid (a1) in the aromatic ester compound (A) may be divalent to hexavalent. In other words, the aromatic ester compound (A) may have a structure in which 2 to 6 carboxylic acids (or acid halides thereof, or esters thereof) contained in one molecule of the aromatic polycarboxylic acid (a1) contribute to an ester bond.
Similarly, the group derived from the polyhydric alcohol compound (a3) in the aromatic ester compound (A) may be divalent to hexavalent. In other words, the aromatic ester compound (A) may have a structure in which 2 to 6 hydroxyl groups contained in one molecule of the polyhydric alcohol compound (a3) contribute to an ester bond.

More specifically, the aromatic ester compound (A) of this embodiment may have a chemical structure in which a partial structure represented by the following general formula (i), in which identical or different aromatic rings are linked together via an ester bond, a residue of a polyhydric alcohol compound (a3) (for example, a divalent to hexavalent hydrocarbon group having at least carbon and hydrogen in the molecule of the polyhydric alcohol compound (a3) (examples of the divalent to hexavalent hydrocarbon group are alkylene chains or alkylene ether chains (however, the —CH ₂ — group in the alkylene chain or the alkylene ether chain may be substituted with a divalent aromatic group))) and an optional residue of a polyvalent hydroxy aromatic compound (a4) are linked together.

(In the above general formula (i), Ar ⁱ¹ represents a monovalent aromatic group, Ar ⁱ² represents a divalent aromatic group, and the dashed line in the above general formula (i) represents a bond to another atom.)

The same or different aromatic rings correspond to the aromatic rings in the molecule of the aromatic polycarboxylic acid (a1) or the monohydroxy aromatic compound (a2). More specifically, the monovalent aromatic group Ar ⁱ¹ in the general formula (i) corresponds to the aromatic ring in the molecule of the monohydroxy aromatic compound (a2), and the divalent aromatic group Ar ⁱ² in the general formula (i) corresponds to the aromatic polycarboxylic acid (a1).

As a result of the above, the aromatic ring, which is a rigid mesogenic skeleton, and the alkylene chain, which is a flexible segment, coexist with a certain regularity (repeating unit) within the same molecule of the aromatic ester compound (A), making it possible to form a cured product that serves as an insulating material with excellent adhesion, low elasticity, dielectric properties, and elongation.

The aromatic ester compound (A) of the present embodiment is represented by the following general formula (1):
[In the above general formula (1), ^Q11 and ^Q12 each independently represent a group derived from an aromatic polycarboxylic acid, an acid halide thereof and/or an ester thereof (a1); ^Ar11 and ^Ar12 each independently represent a group derived from a monohydroxy aromatic compound (a2); A each independently represent a group derived from a polyhydric alcohol compound (a3); and ^p11 represents an average repeat number of 0.01 or more.]
For convenience of explanation, the above-mentioned "group derived from" is a term that indicates the correspondence between the symbols in general formula (1) and each raw material component, and does not indicate all structural moieties derived from each reaction raw material that remain in aromatic ester compound (A) after the reaction.

^Q11 and ^Q12 in the general formula (1) each independently represent a group derived from an aromatic polycarboxylic acid, its acid halide, and/or its ester (a1) (hereinafter also referred to as a group derived from aromatic polycarboxylic acids (a1)). The group derived from aromatic polycarboxylic acids (a1) is preferably, for example, a divalent aromatic group, more preferably an unsubstituted divalent aromatic group. ^Q11 and ^Q12 in the general formula (1) are preferably divalent aromatic groups. Examples of such divalent aromatic groups include groups in which two hydrogen atoms have been removed from the above-mentioned examples of aromatic rings having 3 to 30 carbon atoms. Among these, ^Q1 and ^Q2 are more preferably either a phenylene group, a naphthalenediyl group, or an anthracenediyl group. Furthermore, ^Q11 and ^Q12 may be the same or different from each other. Among these, from the viewpoints of industrial availability of raw materials and solubility, Q ¹¹ and Q ¹² are more preferably phenylene groups.

A in the above general formula (1) represents a group derived from a polyhydric alcohol compound (a3) and may contain at least one bond structure selected from the group consisting of a hydrocarbon bond (divalent to hexavalent hydrocarbon group), a carbonate bond, an ester bond, an ether bond, a urethane bond, and a siloxane bond.

The group derived from the polyhydric alcohol compound (a3) preferably has 2 to 20 carbon atoms, more preferably 4 to 18 carbon atoms. When the number of carbon atoms of A corresponding to the flexible segment in the general formula (1) is within the above range, the aromatic ester compound (A) has excellent compatibility, which is a preferred embodiment. Furthermore, the residue of the polyhydric alcohol compound (a3) is preferably linear or branched, more preferably linear.
Furthermore, the group derived from the polyhydric alcohol compound (a3) is a linear or branched alkylene group, or a linear or branched alkylene ether group, and -CH ₂ - in the alkylene group or alkylene ether group may be substituted with -O- or -S- so as not to be adjacent to each other, or one or more -CH ₂ -CH ₂ - in the alkylene group may be substituted with at least one bond selected from the group consisting of -CH═CH-, a carbonate ester bond, an ester bond, an ether bond, a urethane bond, and a siloxane bond so as not to be adjacent to each other.

Ar ¹¹ and Ar ¹² in the above general formula (1) each independently represent a group derived from the monohydroxy aromatic compound (a2), and are represented by the following general formula (2) or (3):
[In the general formula (2) and the general formula (3), * represents a bond to the oxygen atom bonding to Ar ¹¹ or Ar ¹² in the general formula (1),
R ²¹ and R ³¹ each independently represent a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, or an aralkyl group, k ²¹ represents an integer of 0 to 7, and k ³¹ represents an integer of 0 to 5.

In the general formula (1), Ar ¹¹ is preferably a group having a structure represented by the general formula (3). In the general formula (1), Ar ¹² is preferably a group having a structure represented by the general formula (3).

R ²¹ in the above general formula (2) is preferably any one of a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, and an aralkyl group, and among these, from the viewpoints of dielectric properties, workability, and flexibility of the obtained cured product, it is more preferably an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an aralkyl group such as a benzyl group, a diphenylmethyl group, or a naphthylmethyl group, or an arylene group such as a phenyl group, a naphthyl group, a phenalenyl group, a phenanthrenyl group, or an anthryl group.

R ³¹ in the above general formula (3) is preferably any one of a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, and an aralkyl group, and among these, from the viewpoints of dielectric properties, workability, and flexibility of the obtained cured product, it is more preferably an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an aralkyl group such as a benzyl group, a diphenylmethyl group, or a naphthylmethyl group, or an arylene group such as a phenyl group, a naphthyl group, a phenalenyl group, a phenanthrenyl group, or an anthryl group.

In the general formula (2), ^k21 represents an integer of 0 to 7, but from the viewpoint of reactivity or the flexibility of the resulting cured product, it is more preferably an integer of 0 to 5, and even more preferably an integer of 0 to 4. In addition, in the general formula (3), ^k31 represents an integer of 0 to 5, but from the viewpoint of reactivity or the flexibility of the resulting cured product, it is more preferably an integer of 0 to 4.

In the general formula (1), ^p11 is an average repeat number of 0.01 or more, and from the viewpoints of workability and flexibility of the resulting cured product, it is more preferable that the average repeat number is 0.1 to 5, and even more preferably 0.2 to 5.

The average repeat number ^p1 of the aromatic ester compound (A) is calculated from the charge ratio using the following formula (1).
Formula (1): (average repeat number p ¹ in the obtained aromatic ester compound (A))=(number of moles of hydroxyl groups in the polyhydric alcohol compound (a3))/[(number of moles of active ester groups in the active ester group-containing intermediate product (a′) produced from the reaction raw materials)−(number of moles of hydroxyl groups in the polyhydric alcohol compound (a3)]
The active ester group-containing intermediate product (a') is a reaction product obtained by reacting an aromatic polycarboxylic acid, its acid halide and/or its ester (a1) with a monohydroxy aromatic compound (a2) as reaction raw materials.

Another embodiment of the aromatic ester compound (A) of this embodiment is represented by the following general formula (1'):
[In the above general formula (1'), Q ¹¹ , Q ¹² and Q ¹³ each independently represent a group derived from an aromatic polycarboxylic acid, an acid halide thereof and/or an ester thereof (a1); Ar ¹¹ and Ar ¹² each independently represent a group derived from a monohydroxy aromatic compound (a2); Ar ¹³ each independently represent a group derived from a polyhydric hydroxy aromatic compound (a4); each A independently represent a group derived from a polyhydric alcohol compound (a3); and p ¹¹ is an average repeat number of 0.01 or more.]

<Reaction raw materials for aromatic ester compound (A)>
The reaction raw materials for the aromatic ester compound (A) will be described below.

-Aromatic polycarboxylic acid, its acid halide and/or ester (a1)-
In this embodiment, the aromatic polycarboxylic acid, its acid halide and/or ester (a1) (a compound having a partial structure represented by ^Q11 and/or ^Q12 in the above general formula (1)) is a carboxylic acid having two or more carboxyl groups or a derivative thereof, specifically, a carboxylate, an acid halide, or an ester. By using the aromatic polycarboxylic acids (a1), the monohydroxy aromatic compound (a2) described below (a compound having a partial structure represented by Ar ¹¹ and/or Ar ¹² in the general formula (1) above), and the polyhydric alcohol compound (a3) (a compound having a partial structure represented by A in the general formula (1) above) as reaction raw materials, an ester structure can be formed in the structure of the aromatic ester compound (A) that contains both a structural moiety having flexibility derived from the polyhydric alcohol compound (a3) (e.g., A in the general formula (1) above) and an ester group (specifically, a polyaryloxycarbonyl structure) having an aromatic ring at the end (e.g., Q ¹¹ and/or Q ¹² and Ar ¹¹ and/or Ar ¹² in the general formula (1) above), thereby having high reactivity.

Aromatic polycarboxylic acids (a1) are typically compounds in which at least two carboxyl groups or the like are bonded to a substituted or unsubstituted aromatic ring. However, the carboxyl group or the like moiety may be, in addition to a carboxyl group, an acyl halide group such as an acyl fluoride group, an acyl chloride group, or an acyl bromide group; an alkyloxycarbonyl group such as a methyloxycarbonyl group or an ethyloxycarbonyl group; or an aryloxycarbonyl group such as a phenyloxycarbonyl group or a naphthyloxycarbonyl group. In other words, when the carboxyl group or the like moiety is an acyl halide group, the aromatic polycarboxylic acid (a1) is an acid halide. Similarly, when the carboxyl group or the like moiety is an alkyloxycarbonyl group or an aryloxycarbonyl group, the aromatic polycarboxylic acid (a1) is an esterified product. The aromatic polycarboxylic acids (a1) preferably have a carboxyl group, an acyl halide group, or an aryloxycarbonyl group, more preferably have a carboxyl group or an acyl halide group, and even more preferably have a carboxyl group, an acyl chloride group, or an acyl bromide group.

The aromatic ring is not particularly limited, but examples include monocyclic aromatic rings, fused aromatic rings, ring-assembly aromatic rings, and aromatic rings linked by alkylene chains. From the standpoints of flexibility of the resulting cured product, ease of industrial availability of raw materials, and workability, the aromatic ring is preferably a monocyclic aromatic ring or a fused aromatic ring.

The valence (number) of the carboxyl groups in the aromatic polycarboxylic acids (a1) is preferably divalent to tetravalent, and more preferably divalent.

Specific examples of aromatic polycarboxylic acids (a1) include benzenedicarboxylic acids such as isophthalic acid, terephthalic acid, 5-allylisophthalic acid, and 2-allylterephthalic acid; benzenetricarboxylic acids such as trimellitic acid and 5-allyltrimellitic acid; naphthalene dicarboxylic acids such as naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,3-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, 3-allylnaphthalene-1,4-dicarboxylic acid, and 3,7-diallylnaphthalene-1,4-dicarboxylic acid; pyridinetricarboxylic acids such as 2,4,5-pyridinetricarboxylic acid; triazinecarboxylic acids such as 1,3,5-triazine-2,4,6-tricarboxylic acid; and acid halides and esters of these.

Of the above-mentioned examples, from the viewpoints of flexibility of the obtained cured product, ease of industrial availability of raw materials, and workability, the aromatic polycarboxylic acids (a1) are preferably benzenedicarboxylic acid, benzenetricarboxylic acid, naphthalenedicarboxylic acid, and acid halides thereof, more preferably isophthalic acid, terephthalic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,3-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, 1,3,5-benzenetricarboxylic acid, and acid halides thereof, and even more preferably isophthalic acid chloride and terephthalic acid chloride.
The aromatic polycarboxylic acids (a1) may be used alone or in combination of two or more.

-Monohydroxy aromatic compound (a2)-
The monohydroxy aromatic compound (a2) is an aromatic compound having one aromatic hydroxyl group. Specific examples of the monohydroxy aromatic compound (a2) include alkylphenols such as phenol, o-cresol, m-cresol, p-cresol, 2,4-xylenol, 2,6-xylenol, and tertiary butylphenol; aralkylphenols such as o-phenylphenol, p-phenylphenol, 2-benzylphenol, 4-benzylphenol, styrenated phenol, and 4-(α-cumyl)phenol; and naphthol compounds such as 1-naphthol and 2-naphthol. Among these, o-cresol and naphthol are preferred as the monohydroxy aromatic compound (a2) from the viewpoint of superior dielectric properties.
The monohydroxy aromatic compound (a2) may be used alone or in combination of two or more kinds.

-Polyhydric alcohol compound (a3)-
In this embodiment, the polyhydric alcohol compound (a3) is a compound having at least two hydroxyl groups and belongs to a group of compounds also called polyols. Furthermore, the polyhydric alcohol compound (a3) in this embodiment is required to have a hydroxyl equivalent of 270 g/eq or more. By setting the hydroxyl equivalent to 270 g/eq or more, the properties derived from the polyhydric alcohol compound (a3) are more easily exhibited, and the flexibility of the cured product can be improved. From the same viewpoint, the hydroxyl equivalent of the polyhydric alcohol compound (a3) is preferably 300 g/eq or more. Furthermore, the hydroxyl equivalent of the polyhydric alcohol compound (a3) is not particularly limited, but can be 10,000 g/eq or less. The hydroxyl equivalent is a value measured in accordance with JIS K 0070.

The valence (number) of the hydroxyl groups in the polyhydric alcohol compound (a3) is preferably from divalent to hexavalent, and more preferably divalent.

The polyhydric alcohol compound (a3) may or may not contain an aromatic ring. The optional polyhydric hydroxy aromatic compound (a4) is a compound in which only two to six hydrogen atoms of the aromatic ring in the aromatic group are substituted with hydroxyl groups, while the polyhydric alcohol compound (a3) contains a polyol other than the polyhydric hydroxy aromatic compound (a4).
The polyhydric alcohol compound (a3) is preferably a polyol having an aliphatic hydroxyl group. The segment derived from the polyol having an aliphatic hydroxyl group has low polarity and is more flexible, and therefore can effectively improve the low dielectric properties and flexibility of the resulting aromatic ester compound (A).
The polyhydric alcohol compound (a3) may be used alone or in combination of two or more kinds.

Examples of the polyol having an aliphatic hydroxyl group include hydrocarbon polyols (a3-1), polycarbonate polyols (a3-2), polyester polyols (a3-3), polyether polyols (a3-4), polyurethane polyols (a3-5), and polysiloxane polyols (a3-6). Among these, hydrocarbon polyols (a3-1), polycarbonate polyols (a3-2), polyester polyols (a3-3), polyether polyols (a3-4), and polysiloxane polyols (a3-6) are preferred as polyols having an aliphatic hydroxyl group from the viewpoints of flexibility and heat resistance.

--Hydrocarbon polyol (a3-1)--
Examples of the hydrocarbon polyol (a3-1) include hydrocarbon monomer polyols containing hydrocarbon monomers such as ethylene, propylene, butadiene, and styrene as essential constituent monomers; diol compounds synthesized from dimer acids; etc. Among these, from the viewpoint of flexibility, hydrocarbon monomer polyols are preferred as the hydrocarbon polyol (a3-1), and butadiene polyols containing butadiene monomers as essential constituent monomers are more preferred.

The hydrocarbon monomer polyol may also be copolymerized with other polymerizable monomers. Examples of other polymerizable monomers include aliphatic monoolefin compounds such as butylene, pentene, 2-methyl-1-pentene, hexene, 3-methyl-1-hexene, and 3-methyl-2-hexene; alicyclic monoolefin compounds such as cyclohexene; styrene compounds such as 4-methylstyrene and α-methylstyrene; and acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and 2-(dimethylamino)ethyl (meth)acrylate. vinyl ester compounds such as vinyl acetate and vinyl propionate; vinyl ether compounds such as vinyl methyl ether and vinyl ethyl ether; vinyl ketone compounds such as vinyl methyl ketone and methyl isopropenyl ketone; ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, and itaconic anhydride; nitrogen-containing compounds such as (meth)acrylonitrile, (meth)acrylamide, vinylpyridine, and vinylpyrrolidone; and halogen-containing compounds such as vinyl chloride, vinylidene chloride, and vinyl fluoride. These other polymerizable monomers may be used alone or in combination of two or more.

Commercially available hydrocarbon monomer polyols may be used. Examples of commercially available products include the G series manufactured by Nippon Soda Co., Ltd. ("G-1000" number average molecular weight (Mn) 1,400, hydroxyl value 68 to 78 mg KOH/g, "G-2000" number average molecular weight (Mn) 1,900, hydroxyl value 35 to 55 mg KOH/g, "G-3000" number average molecular weight (Mn) 3,000, hydroxyl value 27 mg KOH/g or more, all of which are hydroxyl-terminated polybutadienes).

Commercially available diol compounds may be used as diol compounds synthesized from dimer acids. Examples of commercially available products include Pripol 2033 (hydroxyl value 202-212 mgKOH/g) from Croda Japan.

The number average molecular weight (Mn) of the hydrocarbon polyol (a3-1) is preferably 500 to 10,000, more preferably 700 to 6,000, and even more preferably 900 to 4,000. When the number average molecular weight is within the above range, the dielectric properties and workability of the resulting aromatic ester compound (A) can be further improved.
In this specification, the number average molecular weight (Mn) is a value published by the manufacturer or a value obtained by measurement using gel permeation chromatography (GPC).

--Polycarbonate polyol (a3-2)--
Examples of the polycarbonate polyol (a3-2) include polyols obtained by adding hydroxyl groups to the terminals of the reaction product of a carbonate ester and/or phosgene with a low molecular weight polyol.

Examples of carbonate esters include methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, and diphenyl carbonate.

From the viewpoint of imparting flexibility, the number of carbon atoms in the low molecular weight polyol is preferably 2 to 20, and more preferably 4 to 18. Specific examples of low molecular weight polyols include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 2,5-hexanediol, 1,7-heptanediol, and 1,8-octanol. Examples include hexanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, 1,4-cyclohexanedimethanol, hydroquinone, resorcinol, bisphenol A, bisphenol F, and 4,4'-biphenol.

Examples of polycarbonate polyols (a3-2) include aliphatic polycarbonate polyols and alicyclic polycarbonate polyols (for example, those obtained by reacting cyclohexanedimethanol and its derivatives). Of these, aliphatic polycarbonate polyols are preferred as polycarbonate polyols (a3-2) from the standpoint of flexibility.

The number average molecular weight (Mn) of the polycarbonate polyol (a3-2) is preferably 500 to 5,000, and more preferably 800 to 3,000. Having a number average molecular weight within the above range further improves the workability of the resulting aromatic ester compound (A).

Commercially available polycarbonate polyols (a3-2) may be used. Examples of commercially available products include the Kuraray Polyol Series "C-2090" and "PHC" manufactured by Kuraray Co., Ltd., and the polycarbonate diol "Duranol" manufactured by Asahi Kasei Corporation.

--Polyester polyol (a3-3)--
Examples of the polyester polyol (d-3) include polyester polyols obtained by reacting a dibasic acid such as terephthalic acid, isophthalic acid, adipic acid, azelaic acid, or sebacic acid, or a dialkyl ester thereof, or a mixture thereof, with glycols such as ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, neopentyl glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 3,3'-dimethylolheptane, polyoxyethylene glycol, polyoxypropylene glycol, or polytetramethylene ether glycol, or a mixture thereof; and polyester polyols obtained by ring-opening polymerization of lactones such as polycaprolactone, polyvalerolactone, or poly(β-methyl-γ-valerolactone).

The number average molecular weight (Mn) of the polyester polyol (a3-3) is preferably 500 to 5,000, and more preferably 800 to 3,000. When the number average molecular weight is within the above range, the dielectric properties and workability of the resulting aromatic ester compound (A) can be further improved.

Commercially available polyester polyols (a3-3) may be used. Examples of commercially available products include the Polylite series manufactured by DIC Corporation.

--Polyether polyol (a3-4)--
Examples of the polyether polyol (a3-4) include polyether polyols obtained by polymerizing an oxirane compound such as ethylene oxide, propylene oxide, butylene oxide, or tetrahydrofuran using water or a low-molecular-weight polyol such as ethylene glycol, propylene glycol, trimethylolpropane, glycerin, or bisphenol A as an initiator.

The number average molecular weight (Mn) of the polyether polyol (a3-4) is preferably 500 to 5,000, and more preferably 800 to 3,000. When the number average molecular weight is within the above range, the dielectric properties and workability of the resulting aromatic ester compound (A) can be further improved.

Commercially available polyether polyols (a3-4) may be used. Examples of commercially available products include Sannix GP-400, GP-600, GP-1000, GP-1500, GP-3000, GP-4000V, GA-5000S, FA-908, FA-961, FA-921, FA-703, and FA-757 manufactured by Sanyo Chemical Co., Ltd.; and Actcoal G-28 and MN-5000 manufactured by Mitsui Chemicals, Inc. , MN-4000, P-31, MN-1500; AGC Inc.'s Excelnol 1030, 4030, 5030, 230, 828, 837, Preminol 3005, 3010, 3015, 3020, 7001, 7006, 7012, Preminol S3006, 3011, and Preminol 7021 (tetrafunctional); etc.

--Polyurethane polyol (a3-5)--
Examples of the polyurethane polyol (a3-5) include polyurethane polyols obtained by reacting the various polyols described above with polyisocyanate at an NCO/OH ratio of less than 1. The NCO/OH ratio is more preferably 0.9 or less.

Examples of the polyisocyanate include aromatic polyisocyanates such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, and triphenylmethane triisocyanate; aliphatic polyisocyanates such as 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), lysine diisocyanate, trimethylhexamethylene diisocyanate, and 1,3-(isocyanatomethyl)cyclohexane; polyisocyanate derivatives (modified products) such as biurets of these aromatic or aliphatic polyisocyanates or isocyanurates of these aromatic or aliphatic polyisocyanates; and adducts of these aromatic or aliphatic polyisocyanates modified with trimethylolpropane.

The number average molecular weight (Mn) of the polyurethane polyol (a3-5) is preferably 500 to 5,000, and more preferably 800 to 3,000. When the number average molecular weight is within the above range, the dielectric properties and workability of the resulting aromatic ester compound (A) can be further improved.

Commercially available polyurethane polyols may be used as polyurethane polyols (a3-5).

--Polysiloxane polyol (a3-6)--
Examples of the polysiloxane polyol (a3-6) include dimethylpolysiloxane having a hydroxyl group terminal, and methylphenylpolysiloxane having a hydroxyl group terminal.

The number average molecular weight (Mn) of the polysiloxane polyol (a3-6) is preferably 500 to 5,000, and more preferably 800 to 3,000. When the number average molecular weight is within the above range, the dielectric properties and workability of the resulting aromatic ester compound (A) can be further improved.

Commercially available polysiloxane polyols (a3-6) may be used. Examples of commercially available products include "KF-6000," "KF-6001," "KF-6002," "KF-6003," "X-22-176DX," "X-22-176F," and "X-22-176-GX-A" manufactured by Shin-Etsu Chemical Co., Ltd., and "Silaplane FM-4411," "Silaplane FM-4421," and "Silaplane FM-4425" manufactured by JNC Corporation.

- Compounds showing reactivity with aromatic polycarboxylic acids (a1) or monohydroxy aromatic compounds (a2) -
The reaction raw materials for the aromatic ester compound (A) may optionally further contain a compound that is reactive with the aromatic polycarboxylic acids (a1) or the monohydroxy aromatic compound (a2). Examples of such compounds include polyhydroxy aromatic compounds (a4), such as dihydroxy aromatic compounds, trihydroxy aromatic compounds, tetrahydroxy aromatic compounds, pentahydroxy aromatic compounds, and hexahydroxy aromatic compounds. Preferred polyhydroxy aromatic compounds (a4) include m-dihydroxybenzene, 2,4-toluenediol, 3,5-toluenediol, p-xylene-2,6-diol, m-xylene-4,6-diol, p-dihydroxybenzene, 2,5-toluenediol, and p-xylene-2,5-diol.
The polyhydroxy aromatic compound (a4) may be used alone or in combination of two or more kinds.

<Preferred Form of Aromatic Ester Compound (A)>
The aromatic ester compound (A) of the present embodiment is represented by the following general formula (1):
[In the above general formula (1), each A independently represents a linear or branched alkylene group, or a linear or branched alkylene ether group,
Q ¹¹ and Q ¹² each independently represent a divalent aromatic group;
Ar ¹¹ and Ar ¹² each independently represent the following general formula (2) or (3):
[In the general formula (2) and the general formula (3), * represents a bond to the oxygen atom bonding to Ar ¹¹ or Ar ¹² in the general formula (1),
R ²¹ and R ³¹ each independently represent a halogen atom, an alkyl group, an alkenyl group (such as an allyl group), an alkoxy group, an aryl group, or an aralkyl group, k ²¹ represents an integer of 0 to 7, and k ³¹ represents an integer of 0 to 5.
p ¹¹ represents an average number of repetitions of 0.01 or more.]

The aromatic ester compound (A) represented by the above general formula (1) contains a chain-like alkylene group or alkylene ether group with multiple ester bonds and relatively low polarity, making it more likely to function as a flexible segment, and is useful for producing a cured product with excellent flexibility and low dielectric properties.

A more preferred example of the aromatic ester compound (A) of the present embodiment is represented by the general formula (1) above. In the general formula (1), each A independently represents a linear or branched alkylene group (an alkylene group having 1 to 30 carbon atoms) or a linear or branched alkylene ether group (an alkylene ether group having 1 to 30 carbon atoms); Q ¹¹ and Q ¹² independently represent a 1,3-phenylene group or a 1,4-phenylene group; p ¹¹ represents an average repeat number of 0.01 or more and 10 or less;
Ar ¹¹ and Ar ¹² each independently represent a structure represented by the above general formula (2) or (3),
* in the general formula (2) and the general formula (3) represents a bond to the oxygen atom bonded to Ar ¹¹ or Ar ¹² in the general formula (1),
R ²¹ and R ³¹ each independently represent any one of a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, and an aralkyl group, k ³¹ represents an integer of 0 to 7, and k ²¹ represents an integer of 0 to 5.

In the above general formula (1), A is preferably a linear or branched alkylene group or a linear or branched alkylene ether group, more preferably a linear alkylene group or a linear alkylene ether group, and from the standpoint of thermal decomposition resistance, it is even more preferable that it contains a linear alkylene ether group.

<Another preferred embodiment of aromatic ester compound (A)>
Another preferred embodiment of the aromatic ester compound (A) of the present embodiment is a reaction product obtained by using an ester compound (a′) (also referred to as intermediate product (a′)) and a polyhydric alcohol compound (a3) as reaction raw materials (I), and the ester compound (a′) may be a reaction product obtained by using an aromatic polycarboxylic acid, an acid halide thereof and/or an ester thereof (a1) and a monohydroxy aromatic compound (a2) as reaction raw materials (II).

An aromatic polycarboxylic acid (a1) is reacted with a monohydroxy aromatic compound (a2) to form an ester bond to give an ester compound (a'). On the other hand, an ester exchange reaction occurs when the ester compound (a') is reacted with a polyhydric alcohol compound (a3), to give an aromatic ester compound (A) having a terminal aromatic ring-containing group (e.g., an aryloxycarbonyl group).
Therefore, the aromatic ester compound (A) of the present embodiment is preferably a reaction product obtained by reacting a reaction product of an aromatic polycarboxylic acid (a1) and a monohydroxy aromatic compound (a2) with a polyhydric alcohol compound (a3) (e.g., a compound having two or more hydroxyl groups and a linear or branched alkylene chain or a linear or branched alkylene ether chain).

In the resin composition having a polymerizable unsaturated group of this embodiment, the use of an aromatic ester compound (A) results in a cured product having a low dielectric loss tangent and excellent adhesion, low elasticity, dielectric properties, and elongation, which is a preferred embodiment. The reason for this is not entirely clear, but the aromatic ester compound (A) contains an aryloxycarbonyl group (e.g., a partial structure represented by the general formula (i) above, more specifically, an ester structure having Q ¹¹ and/or Q ¹² and Ar ¹¹ and/or Ar ¹² in the general formula (1) above) at its terminal, and therefore exhibits high reactivity with epoxy groups, etc., contained in the component (B) or curing agent described below. This high reactivity can prevent or suppress, for example, the generation of hydroxyl groups resulting from ring-opening of the epoxy group, which is a preferred embodiment. By using a polyhydric alcohol compound (a3) having a flexible segment structure (e.g., A in the above general formula (1)), an alkylene chain (e.g., a divalent aliphatic hydrocarbon group) or an alkylene ether chain (oxyalkylene group) derived from the polyhydric alcohol compound (a3) can be introduced into the structure of the resulting aromatic ester compound (A). This makes it possible to impart flexibility to a cured product obtained using the aromatic ester compound (A), and furthermore, since a structure with low polarity is introduced, the product has excellent low dielectric properties, which is a preferred embodiment.

Furthermore, as described above, the aromatic ester compound (A) does not have, or substantially does not have, hydroxyl groups in its molecule. Therefore, even in the cured product obtained by the reaction of the aromatic ester compound (A), it does not have, or substantially does not have, hydroxyl groups derived from the aromatic ester compound (A). Such an aromatic ester compound (A) can prevent or suppress the generation of hydroxyl groups during curing. In this regard, it is generally known that hydroxyl groups have high polarity and increase the dielectric loss tangent. However, by using the aromatic ester compound (A) of this embodiment, a low dielectric loss tangent can be achieved in the cured product.
Furthermore, since the aromatic ester compound (A) has two or more reactive ester bonds, the crosslink density of the cured product is increased, and the heat resistance can be improved.

<Characteristics of aromatic ester compound (A)>
When the aromatic activated ester group in the aromatic ester compound (A) is used as the functional group, the functional group equivalent of the aromatic ester compound (A) is preferably in the range of 160 to 3000 g/eq. In this case, a cured product having better curability and a lower dielectric constant and dielectric dissipation factor (low dielectric characteristics) can be obtained. From the same viewpoint, the functional group equivalent of the aromatic ester compound (A) is more preferably 180 g/eq or more, even more preferably 200 g/eq or more, and more preferably 2800 g/eq or less, even more preferably 2600 g/eq or less.

The number average molecular weight (Mn) of the aromatic ester compound (A) is preferably 320 to 6000. A number average molecular weight (Mn) of 320 or more can improve the dielectric tangent, and a number average molecular weight (Mn) of 6000 or less can improve moldability. From the same perspective, the number average molecular weight (Mn) of the aromatic ester compound (A) is more preferably 360 or more, even more preferably 400 or more, and more preferably 5600 or less, even more preferably 5200 or less.

In this embodiment, the aromatic ester compound (A) preferably has a softening point of 200°C or less, and more preferably 180°C or less, from the viewpoints of achieving a better balance between handleability when preparing the curable resin composition described below and the heat resistance and dielectric properties of the cured product.

The aromatic ester compound (A) of this embodiment has a flexible segment such as an alkylene chain or an alkylene ether chain, and is free of or substantially free of hydroxyl groups, resulting in a low-polarity structure. This allows for the production of curable resin compositions (e.g., epoxy resin compositions containing an epoxy resin) that can exhibit excellent flexibility (elongation), low elasticity, heat resistance, adhesion to copper foil and the like due to their flexibility, and low dielectric properties in the resulting cured product. Furthermore, semiconductor encapsulating materials, semiconductor devices, prepregs, circuit boards, build-up films, and the like that use the curable resin compositions can be provided.

<Synthesis of aromatic ester compound (A)>
The method for synthesizing the aromatic ester compound (A) is not particularly limited, except that the aromatic polycarboxylic acid (a1), the monohydroxy aromatic compound (a2), and the polyhydric alcohol compound (a3) are used as raw materials and reacted. However, in the synthesis of the aromatic ester compound (A),
(1) a first reaction step in which an aromatic polycarboxylic acid (a1) is reacted with a monohydroxy aromatic compound (a2) to obtain an intermediate product (a'); and
(2) a second reaction step in which the intermediate product (a′) is reacted with a polyhydric alcohol compound (a3) to obtain an aromatic ester compound (A) as a reaction product;
It is preferable to use a method including the steps of:
In this case, in the first reaction step, an ester compound in which an ester bond is formed is obtained as an intermediate product (a'), and in the subsequent second reaction step, an ester exchange reaction occurs to obtain an aromatic ester compound (A) containing an aryloxycarbonyl group structure at its terminal.

The conditions for the first reaction step are not particularly limited, but can be, for example, performed in the presence of an alkali catalyst at a temperature of 60°C or less for a reaction time of 1 to 24 hours. Examples of alkali catalysts include sodium hydroxide, potassium hydroxide, triethylamine, and pyridine. These alkali catalysts may be used alone or in combination of two or more. Among these, sodium hydroxide or potassium hydroxide is preferred as the alkali catalyst due to its high reaction efficiency. The alkali catalyst may be used as a 3 to 30% aqueous solution. In this case, a phase transfer catalyst may be used to improve reaction efficiency. Examples of phase transfer catalysts include alkylammonium salts and crown ethers. These phase transfer catalysts may be used alone or in combination of two or more.

The first reaction step is preferably carried out in an organic solvent, as this facilitates reaction control. Examples of the organic solvent include hydrocarbon solvents such as pentane and hexane; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether solvents such as diethyl ether and tetrahydrofuran; acetate ester solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitol solvents such as cellosolve and butyl carbitol; aromatic hydrocarbon solvents such as toluene and xylene; and amide solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. These organic solvents may be used alone or in combination.

The reaction ratio of the aromatic polycarboxylic acids (a1) and the monohydroxyaromatic compound (a2) can be varied as appropriate depending on the desired molecular design. However, from the perspective of achieving a balanced improvement in adhesion, low elasticity, dielectric properties, and elongation, the ratio of the monohydroxyaromatic compound (a2) to 1 mole of the aromatic polycarboxylic acids (a1) is preferably in the range of 2.0 to 5.0 moles, more preferably in the range of 2.0 to 4.0 moles, and even more preferably in the range of 2.0 to 3.0 moles.

After the reaction in the first reaction step is complete, if an aqueous solution is used in the presence of an alkaline catalyst, it is preferable to allow the reaction solution to stand and separate, remove the aqueous layer, and then wash the remaining organic layer with water, repeating this process until the aqueous layer becomes nearly neutral (pH of about 7). This reduces the content of inorganic salts in the resulting intermediate product (a'), which have a negative effect on insulating properties.

Next, in the second reaction step, the intermediate product (a') obtained in the first reaction step is reacted with a polyhydric alcohol compound (a3). The conditions for the second reaction step are not particularly limited, but for example, the reaction can be carried out at a temperature of 50 to 250°C with stirring for 1 to 24 hours. Furthermore, in the second reaction step, the reaction can be accelerated by adding an alkaline catalyst, particularly an amine catalyst (alkylamines such as triethylamine, arylamines such as triphenylamine, fused amines such as DBU and DBN, or heterocyclic amines such as imidazole and pyridine).

During the reaction in the second reaction step, an antioxidant may be used to prevent deterioration due to contamination with trace amounts of oxygen. Specific examples of the antioxidant include p-methoxyphenol, 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, 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, "4-[[4,6-bis(octylthio) phenolic compounds such as 1,3,5-triazin-2-yl]amino]-1,6-di-tert-butylphenol, quinone compounds such as hydroquinone, methylhydroquinone, p-benzoquinone, methyl-p-benzoquinone, 2,5-diphenylbenzoquinone, 2-hydroxy-1,4-naphthoquinone, anthraquinone, and diphenoquinone, melamine, p-phenylenediamine, 4-aminodiphenylamine, N,N'-diphenyl-p-phenylenediamine, N-i-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), styrenated diphenylamine, reaction products of styrenated diphenylamine and 2,4,4-trimethylpentene, reaction products of diphenylamine and 2,4,4-trimethylpentene, amine compounds such as phenothiazine, distearyl thiodipropionate, 2,2-bis({[3 -(dodecylthio)propionyl]oxy}methyl)-1,3-propanediyl bis[3-(dodecylthio)propionate], ditridecan-1-yl 3,3'-sulfanediyldipropanoate and other thioether compounds; N-nitrosodiphenylamine, N-nitrosophenylnaphthylamine, p-nitrosophenol, nitrosobenzene, p-nitrosodiphenylamine, α-nitroso-β-naphthol and the like; N,N-dimethyl p-nitrosoaniline, p-nitrosodiphenylamine, p-nitrosodimethylamine; p-nitroso-N,N-diethylamine, N-nitrosoethanolamine, N-nitrosodi-n-butylamine, N-nitroso-N-n-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 compounds such as 1-nitroso-N-n-propylurethane, 1-nitroso-2-naphthol, 2-nitroso-1-naphthol, sodium 1-nitroso-2-naphthol-3,6-sulfonate, sodium 2-nitroso-1-naphthol-4-sulfonate, 2-nitroso-5-methylaminophenol hydrochloride, and 2-nitroso-5-methylaminophenol hydrochloride; esters of phosphoric acid and octadecan-1-ol, triphenyl phosphite, 3,9-dioctadecan-1-yl-2,4,8,10-tetraoxa-3,9-di Phosphite compounds such as phosphaspiro[5.5]undecane, trisnonylphenyl phosphite, phosphorous acid-(1-methylethylidene)-di-4,1-phenylenetetra-C12-15-alkyl ester, 2-ethylhexyl diphenyl phosphite, diphenyl isodecyl phosphite, triisodecyl phosphite, tris(2,4-di-tert-butylphenyl) phosphite, bis(dimethyldithiocarbamato-κ(2)S,S')zinc, zinc diethyldithiocarbamate, dibutyl dithiocarbamate, zinc compounds such as zinc phosphate, nickel compounds such as bis(N,N-dibutylcarbamodithioato-S,S')nickel, and sulfur compounds such as 1,3-dihydro-2H-benzimidazole-2-thione, 4,6-bis(octylthiomethyl)-o-cresol, 2-methyl-4,6-bis[(octan-1-ylsulfanyl)methyl]phenol, dilauryl thiodipropionate, and distearyl 3,3'-thiodipropionate. These antioxidants can be used alone or in combination of two or more.
Examples of commercially available antioxidants include "Q-1300" and "Q-1301" manufactured by Wako Pure Chemical Industries, Ltd., and "Sumilizer BBM-S" and "Sumilizer GA-80" manufactured by Sumitomo Chemical Co., Ltd.

In the second reaction step, the same solvent as used in the first reaction step can be used.

The reaction ratio of intermediate product (a') and polyhydric alcohol compound (a3) can be changed as appropriate depending on the desired molecular design. However, from the perspective of obtaining an aromatic ester compound (A) with greater workability and flexibility, the hydroxyl group equivalent of polyhydric alcohol compound (a3) per equivalent of active ester groups in intermediate product (a') is preferably in the range of 0.01 to 0.9 mol, more preferably in the range of 0.05 to 0.9 mol, and even more preferably in the range of 0.1 to 0.8 mol.

After completion of the reaction in the second reaction step, it is preferable to perform atmospheric distillation or reduced pressure distillation (e.g., 0.9 to 0.01 atmospheres) to remove excess monohydroxyaromatic compound (a2). This increases the purity of the resulting aromatic ester compound (A).

(Epoxy resin (B) having a polymerizable unsaturated group)
The epoxy resin (B) having a polymerizable unsaturated group is one of the essential components of the resin composition having a polymerizable unsaturated group of this embodiment. The epoxy resin (B) having a polymerizable unsaturated group is a resin obtained from an epoxy resin (b1) and an unsaturated monobasic acid (b2) as essential reaction raw materials. Typically, the epoxy resin (B) having a polymerizable unsaturated group can be obtained by reacting the epoxy group of the epoxy resin (b1) with the acid group of the unsaturated monobasic acid (b2).

The epoxy resin (B) having a polymerizable unsaturated group preferably has an epoxy group and a (meth)acryloyl group. In this case, a better balance of adhesion, low elasticity, dielectric properties, and elongation can be achieved. This can be achieved, for example, by appropriately adjusting the relative amounts of the epoxy resin (b1) and the unsaturated monobasic acid (b2) used so that the epoxy groups of the epoxy resin (b1) remain even after the reaction.

The acid value of the epoxy resin (B) having a polymerizable unsaturated group can be, for example, 50 mgKOH/g or less, 30 mgKOH/g or less, 10 mgKOH/g or less, 5 mgKOH/g or less, or 1 mgKOH/g or less. The acid value is measured by the neutralization titration method of JIS K 0070.

The reaction raw materials for epoxy resin (B) having a polymerizable unsaturated group are described below.

<Epoxy resin (b1)>
The specific structure of the epoxy resin (b1) is not particularly limited as long as it has a plurality of epoxy groups in the resin and is capable of reacting with the unsaturated monobasic acid (b2).

Examples of epoxy resins (b1) include bisphenol-type epoxy resins, biphenol-type epoxy resins, phenylene ether-type epoxy resins, naphthylene ether-type epoxy resins, naphthalene-type epoxy resins, biphenyl-type epoxy resins, triphenylmethane-type epoxy resins, phenol novolac-type epoxy resins, cresol novolac-type epoxy resins, bisphenol novolac-type epoxy resins, naphthol novolac-type epoxy resins, naphthol-phenol co-condensed novolac-type epoxy resins, naphthol-cresol co-condensed novolac-type epoxy resins, phenol aralkyl-type epoxy resins, naphthol aralkyl-type epoxy resins, dicyclopentadiene-phenol addition reaction-type epoxy resins, biphenyl aralkyl-type epoxy resins, fluorene-type epoxy resins, xanthene-type epoxy resins, dihydroxybenzene-type epoxy resins, trihydroxybenzene-type epoxy resins, and oxazolidone-type epoxy resins, as well as hydrogenated versions of these. Among these, from the viewpoint of achieving a balanced improvement in adhesion, low elasticity, dielectric properties, and elongation, bisphenol-type epoxy resins, hydrogenated bisphenol-type epoxy resins, biphenol-type epoxy resins, hydrogenated biphenol-type epoxy resins, naphthalene-type epoxy resins, and dihydroxybenzene-type epoxy resins are preferred as the epoxy resin (b1), with bisphenol-type epoxy resins, hydrogenated bisphenol-type epoxy resins, and naphthalene-type epoxy resins being more preferred. These epoxy resins (b1) may be used alone or in combination of two or more.

Examples of bisphenol-type epoxy resins include bisphenol A-type epoxy resins, bisphenol AP-type epoxy resins, bisphenol B-type epoxy resins, bisphenol BP-type epoxy resins, bisphenol E-type epoxy resins, bisphenol F-type epoxy resins, and bisphenol S-type epoxy resins.

Examples of hydrogenated bisphenol epoxy resins include hydrogenated bisphenol A epoxy resins, hydrogenated bisphenol B epoxy resins, hydrogenated bisphenol E epoxy resins, hydrogenated bisphenol F epoxy resins, and hydrogenated bisphenol S epoxy resins.

Examples of biphenol-type epoxy resins include 4,4'-biphenol-type epoxy resin, 2,2'-biphenol-type epoxy resin, tetramethyl-4,4'-biphenol-type epoxy resin, and tetramethyl-2,2'-biphenol-type epoxy resin.

Examples of hydrogenated biphenol-type epoxy resins include hydrogenated 4,4'-biphenol-type epoxy resins, hydrogenated 2,2'-biphenol-type epoxy resins, hydrogenated tetramethyl-4,4'-biphenol-type epoxy resins, and hydrogenated tetramethyl-2,2'-biphenol-type epoxy resins.

When the epoxy resin (b1) is any of a bisphenol-type epoxy resin, a hydrogenated bisphenol-type epoxy resin, a biphenol-type epoxy resin, a hydrogenated biphenol-type epoxy resin, and a dihydroxybenzene-type epoxy resin, the epoxy equivalent of the epoxy resin (b1) is preferably in the range of 110 to 400 g/eq, from the viewpoint of obtaining a resin composition having polymerizable unsaturated groups with excellent heat resistance and dielectric properties.

<Unsaturated monobasic acid (b2)>
The unsaturated monobasic acid (b2) refers to a compound having an acid group and a polymerizable unsaturated bond in one molecule. In this specification, the term "polymerizable unsaturated bond" refers to an unsaturated bond that can be radically polymerized.

Examples of the acid group include a carboxyl group, a sulfonic acid group, and a phosphate group.

Examples of unsaturated monobasic acids (b2) include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, α-cyanocinnamic acid, β-styrylacrylic acid, β-furfurylacrylic acid, and their esters, acid halides, and acid anhydrides. Also, examples of unsaturated monobasic acids (b2) include those represented by the following general formula (4):

It is also possible to use a compound represented by the following general formula (4): [In the above general formula (4), X ⁴¹ represents an alkylene chain having 1 to 10 carbon atoms, a polyoxyalkylene chain, a (poly)ester chain, an aromatic hydrocarbon chain, or a (poly)carbonate chain, a hydrogen atom in the structure of X ⁴¹ may be substituted with a halogen atom or an alkoxy group, and Y ⁴¹ represents a hydrogen atom or a methyl group.]

Examples of the polyoxyalkylene chain include polyoxyethylene chains and polyoxypropylene chains.

The (poly)ester chain may, for example, be represented by the following general formula (5):

[In the above general formula (5), R ⁵¹ and R ⁵² each independently represent an alkylene group having 1 to 10 carbon atoms, and q ⁵¹ represents an integer of 1 to 5.]

Examples of the aromatic hydrocarbon chain include a phenylene chain, naphthylene chain, biphenylene chain, phenylnaphthylene chain, and binaphthylene chain. Hydrocarbon chains having aromatic rings such as benzene rings, naphthalene rings, anthracene rings, and phenanthrene rings as partial structures can also be used.

The (poly)carbonate chain may, for example, be represented by the following general formula (6):

In the above general formula (6), R ⁶¹ represents an alkylene group having 1 to 10 carbon atoms, and q ⁶¹ represents an integer of 1 to 5.

The molecular weight of the compound represented by formula (4) above is preferably in the range of 100 to 500, and more preferably in the range of 150 to 400.

These unsaturated monobasic acids (b2) may be used alone or in combination of two or more.

The amount of unsaturated monobasic acid (b2) used when obtaining epoxy resin (B) having a polymerizable unsaturated group is preferably in the range of 0.2 to 0.8 moles per mole of epoxy resin (b1), from the viewpoint of ensuring that the resulting epoxy resin (B) having a polymerizable unsaturated group contains an epoxy group and a (meth)acryloyl group, thereby achieving a balanced improvement in adhesion, low elasticity, dielectric properties, and elongation.

Furthermore, the number of moles of acid groups in the unsaturated monobasic acid (b2) per mole of epoxy groups in the epoxy resin (b1) is preferably in the range of 0.2 to 0.8. In this case, the resulting epoxy resin (B) having a polymerizable unsaturated group contains epoxy groups and (meth)acryloyl groups, achieving a balanced improvement in adhesion, low elasticity, dielectric properties, and elongation.

The epoxy resin (B) having a polymerizable unsaturated group may be produced by any method without particular limitations. For example, it may be produced by reacting all of the reactant materials containing the epoxy resin (b1) and unsaturated monobasic acid (b2) at once, or by reacting the reactant materials sequentially. In particular, because this method makes it easier to control the reaction, it is preferred to produce the epoxy resin (b1) and unsaturated monobasic acid (b2) by reacting them in the presence of a basic catalyst at a temperature of 80 to 140°C, followed by adding an acidic compound and mixing at a temperature of 50 to 100°C to deactivate the basic catalyst.

Examples of basic catalysts include N-methylmorpholine, pyridine, 1,8-diazabicyclo[5.4.0]undecene-7 (DBU), 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-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropylmethyldimethoxysilane, and amine compounds such as tetramethylammonium hydroxide; trioctylmethylammonium chloride, trioctylmethylammonium chloride, and trioctylmethylammonium chloride. quaternary ammonium salts such as octylmethylammonium acetate; phosphines such as trimethylphosphine, tributylphosphine, and triphenylphosphine; phosphonium salts such as tetramethylphosphonium chloride, tetraethylphosphonium chloride, tetrapropylphosphonium chloride, tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, trimethyl(2-hydroxypropyl)phosphonium chloride, triphenylphosphonium chloride, and benzylphosphonium chloride; organic tin compounds such as dibutyltin dilaurate, octyltin trilaurate, octyltin diacetate, dioctyltin diacetate, dioctyltin dineodecanoate, dibutyltin diacetate, tin octoate, and 1,1,3,3-tetrabutyl-1,3-dodecanoyldistannoxane; organic metal compounds such as zinc octoate and bismuth octoate; inorganic tin compounds such as tin octoate; and inorganic metal compounds. In addition, alkaline earth metal hydroxides, alkali metal carbonates, alkali metal hydroxides, etc. can also be used.
These basic catalysts may be used alone or in combination of two or more.

From the viewpoint of obtaining a resin composition having polymerizable unsaturated groups with excellent adhesion, low elasticity, dielectric properties, and elongation, the amount of the basic catalyst used is preferably in the range of 0.01 to 0.5 parts by mass, and more preferably in the range of 0.01 to 0.4 parts by mass, per 100 parts by mass of the epoxy resin (b1) and unsaturated monobasic acid (b2) combined.

The reaction between the epoxy resin (b1) and the unsaturated monobasic acid (b2) can also be carried out in an organic solvent, if necessary. Examples of organic solvents include ketone solvents such as methyl ethyl ketone, acetone, dimethylformamide, and methyl isobutyl ketone; cyclic ether solvents such as tetrahydrofuran and dioxolane; 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; alcohol solvents such as carbitol, cellosolve, methanol, isopropanol, butanol, and propylene glycol monomethyl ether; glycol ether solvents such as alkylene glycol monoalkyl ethers, dialkylene glycol monoalkyl ethers, and dialkylene glycol monoalkyl ether acetates; methoxypropanol, cyclohexanone, methyl cellosolve, diethylene glycol monoethyl ether acetate, and propylene glycol monomethyl ether acetate. These organic solvents may be used alone or in combination. Additionally, the amount of organic solvent used is preferably in the range of approximately 0.1 to 5 times the total mass of the reaction raw materials, as this improves reaction efficiency.

Examples of acidic compounds include inorganic acids such as hydrochloric acid, sulfuric acid, and phosphoric acid; and organic acids such as methanesulfonic acid, paratoluenesulfonic acid, and oxalic acid. These acidic compounds may be used alone or in combination of two or more.

In addition, in the reaction between the epoxy resin (b1) and the unsaturated monobasic acid (b2) in the presence of a basic catalyst, instead of deactivating the basic catalyst with an acidic compound after the reaction, a method of separating and removing the basic catalyst may be used.

The above are the essential components contained in the resin composition having a polymerizable unsaturated group of this embodiment.

(Optional addition ingredient)
Furthermore, the resin composition having a polymerizable unsaturated group of the present embodiment may contain various known additives such as an ultraviolet stabilizer and a storage stabilizer in addition to the above-mentioned compounds or resins.

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

[Curable resin composition]
The curable resin composition of this embodiment is characterized by containing at least the resin composition having a polymerizable unsaturated group described above and a photopolymerization initiator. In other words, the curable resin composition of this embodiment is characterized by containing at least the aromatic ester compound (A) described above, the epoxy resin (B) having a polymerizable unsaturated group described above, and a photopolymerization initiator.
The photopolymerization initiator may be used alone or in combination of two or more.

(Photopolymerization initiator)
The photopolymerization initiator can be selected appropriately depending on the type of active energy ray to be irradiated, etc. It may also 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. The photopolymerization initiator is preferably a radical polymerization initiator. Specific examples of such photopolymerization initiators include alkylphenone-based photopolymerization initiators such as 1-hydroxycyclohexylphenylketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, and 1,2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone; acylphosphine oxide-based photopolymerization initiators such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide; and intramolecular hydrogen abstraction photopolymerization initiators such as benzophenone compounds.

Furthermore, specific examples of photopolymerization initiators 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(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one.

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", and "Omnirad-4265". Examples include "irad-81" (manufactured by IGM), "Kayacure-DETX", "Kayacure-MBP", "Kayacure-DMBI", "Kayacure-EPA", and "Kayacure-OA" (manufactured by Nippon Kayaku Co., Ltd.), "Baicure-10", "Baicure-55" (manufactured by Stauffer Chemical Co., Ltd.), "Trigonal P1" (manufactured by Akzo), "Sandray 1000" (manufactured by Sandoz), "Deep" (manufactured by Upjohn), "Quantacure-PDO", "Quantacure-ITX", and "Quantacure-EPD" (manufactured by Ward-Blenkinsop), and "Runtecure-1104" (manufactured by Runtec).

The content of the photopolymerization initiator in the curable resin composition of this embodiment is preferably 0.1 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the aromatic ester compound (A) and the epoxy resin (B) having a polymerizable unsaturated group combined.

((Meth)acrylate Monomer)
Furthermore, the curable resin composition of the present embodiment preferably further contains a (meth)acrylate monomer ((meth)acrylate compound) in addition to the aromatic ester compound (A) and the epoxy resin (B) having a polymerizable unsaturated group. In this case, adhesion, low elasticity, dielectric properties, and elongation can be improved in a balanced manner.

Specific examples of the (meth)acrylate monomer include aliphatic mono(meth)acrylate compounds such as methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate, pentyl(meth)acrylate, hexyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, and octyl(meth)acrylate; cyclohexyl(meth)acrylate, isobornyl(meth)acrylate, and adamantyl mono(meth)acrylate. alicyclic mono(meth)acrylate compounds such as glycidyl (meth)acrylate and tetrahydrofurfuryl acrylate; heterocyclic mono(meth)acrylate compounds such as benzyl (meth)acrylate, phenyl (meth)acrylate, phenylbenzyl (meth)acrylate, phenoxy (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxyethoxyethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, phenoxybenzyl ... Mono(meth)acrylate compounds such as aromatic mono(meth)acrylate compounds such as diethyl (meth)acrylate, benzyl benzyl (meth)acrylate, and phenylphenoxyethyl (meth)acrylate; (poly)oxyalkylene-modified mono(meth)acrylate compounds in which a polyoxyalkylene chain such as a (poly)oxyethylene chain, a (poly)oxypropylene chain, or a (poly)oxytetramethylene chain has been introduced into the molecular structure of the above-mentioned various mono(meth)acrylate monomers; lactone-modified mono(meth)acrylate compounds in which a (poly)lactone structure has been introduced into the molecular structure of the above-mentioned various mono(meth)acrylate compounds; 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, and neopentyl glycol di(meth)acrylate; 1,4-cyclohexanedimethanol di(meth)acrylate, norbornane di(meth)acrylate, and the like. alicyclic di(meth)acrylate compounds such as norbornane dimethanol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, and tricyclodecane dimethanol di(meth)acrylate; aromatic di(meth)acrylate compounds such as biphenol di(meth)acrylate and bisphenol di(meth)acrylate; and the above-mentioned various di(meth)acrylate compounds having a (poly)oxyethylene chain, a (poly)oxypropylene chain, a (poly)oxytetramethylene chain, or the like in the molecular structure thereof. polyoxyalkylene-modified di(meth)acrylate compounds having introduced therein a (poly)oxyalkylene chain such as a (poly)oxyalkylene chain; lactone-modified di(meth)acrylate compounds having introduced therein a (poly)lactone structure in the molecular structure of the above-mentioned various di(meth)acrylate compounds; aliphatic tri(meth)acrylate compounds such as trimethylolpropane tri(meth)acrylate and glycerin tri(meth)acrylate; aliphatic tri(meth)acrylate compounds having introduced therein a (poly)oxyethylene chain, a (poly)oxypropane tri(meth)acrylate ... lactone-modified tri(meth)acrylate compounds in which a (poly)oxyalkylene chain such as a propylene chain or a (poly)oxytetramethylene chain has been introduced; lactone-modified tri(meth)acrylate compounds in which a (poly)lactone structure has been introduced into the molecular structure of the aliphatic tri(meth)acrylate compound; tetra- or higher functional aliphatic poly(meth)acrylate compounds such as pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate; tetra- or higher functional (poly)oxyalkylene-modified poly(meth)acrylate compounds in which a (poly)oxyalkylene chain such as a (poly)oxyethylene chain, a (poly)oxypropylene chain, or a (poly)oxytetramethylene chain has been introduced into the molecular structure of the aliphatic poly(meth)acrylate compound; and tetra- or higher functional lactone-modified poly(meth)acrylate compounds in which a (poly)lactone structure has been introduced into the molecular structure of the aliphatic poly(meth)acrylate compound.
The (meth)acrylate monomers may be used alone or in combination of two or more.

The content of the (meth)acrylate monomer is preferably 10 parts by mass or more and 500 parts by mass or less per 100 parts by mass of the aromatic ester compound (A) and the epoxy resin having a polymerizable unsaturated group (B) combined.

(Other various additives)
The curable resin composition of the present embodiment may contain appropriate amounts of various additives, such as other curing agents, curing accelerators, organic solvents, flame retardants, fillers, pigments, antifoaming agents, viscosity modifiers, leveling agents, storage stabilizers, etc., as needed, within the scope of the purpose. However, it is preferable that the curable resin composition of the present embodiment does not contain an organic solvent.

<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.), with epoxy resins being preferred.

The epoxy resin is not particularly limited, but is preferably a curable resin that contains two or more epoxy groups in the molecule and can be cured by forming a crosslinked network with the epoxy groups. The epoxy resin is not particularly limited, but may be a novolac epoxy resin such as a phenol novolac epoxy resin, a cresol novolac epoxy resin, an α-naphthol novolac epoxy resin, a β-naphthol novolac epoxy resin, a bisphenol A novolac epoxy resin, or a biphenyl novolac epoxy resin;
aralkyl-type epoxy resins such as phenol aralkyl-type epoxy resins, naphthol aralkyl-type epoxy resins, and phenol biphenyl aralkyl-type epoxy resins;
bisphenol-type epoxy resins such as bisphenol A-type epoxy resins, bisphenol AP-type epoxy resins, bisphenol AF-type epoxy resins, bisphenol B-type epoxy resins, bisphenol BP-type epoxy resins, bisphenol C-type epoxy resins, bisphenol E-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, and tetrabromobisphenol A-type epoxy resins;
biphenyl-type epoxy resins such as biphenyl-type epoxy resins, tetramethylbiphenyl-type epoxy resins, and epoxy resins having a biphenyl skeleton and a diglycidyloxybenzene skeleton;
Naphthalene-type epoxy resin;
Binaphthol-type epoxy resin; Binaphthyl-type epoxy resin;
dicyclopentadiene-type epoxy resins such as dicyclopentadiene-phenol-type epoxy resins;
glycidylamine-type epoxy resins such as tetraglycidyldiaminodiphenylmethane-type epoxy resins, triglycidyl-p-aminophenol-type epoxy resins, and diaminodiphenylsulfone-type glycidylamine-type epoxy resins;
diglycidyl ester type epoxy resins such as 2,6-naphthalenedicarboxylic acid diglycidyl ester type epoxy resins and hexahydrophthalic anhydride glycidyl ester type epoxy resins;
Benzopyran-type epoxy resins such as dibenzopyran, hexamethyldibenzopyran, and 7-phenylhexamethyldibenzopyran are included.
Among these epoxy resins, so-called glycidyl ether type epoxy resins obtained by epoxidizing a phenol compound are preferred, and among them, novolac type epoxy resins, aralkyl type epoxy resins, and dicyclopentadiene type epoxy resins are more preferred from the viewpoint of dielectric properties. The above-mentioned epoxy resins may be used alone or in combination of two or more kinds.

The epoxy equivalent of the epoxy resin is preferably 120 to 400 g/eq, and more preferably 150 to 300 g/eq. An epoxy equivalent of 120 g/eq or more is preferred because the resulting cured product will have better dielectric properties. On the other hand, an epoxy equivalent of 400 g/eq or less is preferred because the resulting cured product will have an excellent balance of adhesion, low elasticity, dielectric properties, and elongation.

From the perspective of achieving a balanced improvement in adhesion, low elasticity, dielectric properties, and elongation, the softening point of the epoxy resin is preferably 20 to 200°C, and more preferably 40 to 150°C.

Regarding the amount of epoxy resin used, when the ester group in the aromatic ester compound (A) is considered to be the functional group, the functional group equivalent ratio of the aromatic ester compound (A) to the amount of epoxy resin used (aromatic ester compound (A)/epoxy resin) is preferably 0.2 to 2, and more preferably 0.4 to 1.5. A functional group equivalent ratio of 0.2 or more is preferred because the resulting cured product can have a lower dielectric tangent and higher flexibility. If the functional group equivalent ratio exceeds 2, heat resistance and curability decrease, so it is preferable to use it within the above range.

Amine curing agents include, but are not limited to, aliphatic amines such as diethylenetriamine (DTA), triethylenetetramine (TTA), tetraethylenepentamine (TEPA), dipropylenediamine (DPDA), diethylaminopropylamine (DEAPA), N-aminoethylpiperazine, menthenediamine (MDA), isophoronediamine (IPDA), 1,3-bisaminomethylcyclohexane (1,3-BAC), piperidine, N,N-dimethylpiperazine, and triethylenediamine; and aromatic amines such as m-xylenediamine (XDA), methanephenylenediamine (MPDA), diaminodiphenylmethane (DDM), diaminodiphenylsulfone (DDS), benzylmethylamine, 2-(dimethylaminomethyl)phenol, and 2,4,6-tris(dimethylaminomethyl)phenol.

Examples of acid anhydride curing agents include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bistrimellitate, glycerol tristrimellitate, maleic anhydride, tetrahydrophthalic anhydride, methyl tetrahydrophthalic anhydride, endomethylene tetrahydrophthalic anhydride, methyl endomethylene tetrahydrophthalic anhydride, methylbutenyl tetrahydrophthalic anhydride, dodecenyl succinic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, succinic anhydride, and methylcyclohexene dicarboxylic anhydride.

Examples of the phenol resin curing agent include phenol novolac resin, cresol novolac resin, naphthol novolac resin, bisphenol novolac resin, biphenyl novolac resin, dicyclopentadiene-phenol addition type resin, phenol aralkyl resin, naphthol aralkyl resin, triphenolmethane type resin, tetraphenolethane type resin, and aminotriazine-modified phenol resin.
The other curing agents mentioned above may be used alone or in combination of two or more.

Regarding the amount of other curing agents (amine curing agents, acid anhydride curing agents, phenolic resin curing agents) used, when the ester groups in the aromatic ester compound (A) are considered functional groups, the functional group equivalent ratio (aromatic ester compound (A)/other curing agents) relative to the amount of the other curing agents used is preferably 0.2 to 2, more preferably 0.4 to 1.5. A functional group equivalent ratio of 0.2 or greater is preferred because the resulting cured product can have a lower dielectric tangent and higher flexibility. If the functional group equivalent ratio exceeds 2, heat resistance and curability decrease, so it is preferable to use them within the above range.

<Curing accelerator>
The curing accelerator is not particularly limited, but examples thereof include phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, urea-based curing accelerators, etc. The above-mentioned curing accelerators may be used alone or in combination of two or more.

Examples of the phosphorus-based curing accelerator include organic phosphine compounds such as triphenylphosphine, tributylphosphine, tripartylphosphine, diphenylcyclohexylphosphine, and tricyclohexylphosphine; organic phosphite compounds such as trimethyl phosphite and triethyl phosphite; and phosphonium salts such as ethyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, butylphosphonium tetraphenylborate, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, triphenylphosphinetriphenylborane, tetraphenylphosphonium thiocyanate, tetraphenylphosphonium dicyanamide, butylphenylphosphonium dicyanamide, and tetrabutylphosphonium decanoate.

Examples of the amine-based curing accelerator include triethylamine, tributylamine, N,N-dimethyl-4-aminopyridine (DMAP), 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo[5,4,0]-undecene-7 (DBU), and 1,5-diazabicyclo[4,3,0]-nonene-5 (DBN).

The above-mentioned imidazole-based curing accelerators include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, and 1-cyanoethyl-2-methylimidazole. Examples include ethyl-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-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, and 2-methylimidazoline.

Examples of the guanidine-based curing accelerators 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, and 1-phenylbiguanide.

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, and 3-(3,4-dichlorophenyl)-1,1-dimethylurea.

Of the above-mentioned curing accelerators, it is preferable to use 2-ethyl-4-methylimidazole and N,N-dimethyl-4-aminopyridine (DMAP).

The content of the curing accelerator in the curable resin composition of this embodiment can be adjusted as needed to achieve the desired curability, but is preferably 0.01 to 5 parts by mass per 100 parts by mass of the combined total of the (A) and (B) components. A content of 0.01 part by mass or more of the curing accelerator can more reliably enhance curability. On the other hand, a content of 5 parts by mass or less of the curing accelerator can maintain sufficiently good insulation reliability. From the same perspective, the content of the curing accelerator is more preferably 0.1 part by mass or more, and more preferably 3 parts by mass or less, per 100 parts by mass of the combined total of the (A) and (B) components.

<Flame retardants>
The flame retardant is not particularly limited, and examples thereof include inorganic phosphorus-based flame retardants, organic phosphorus-based flame retardants, halogen-based flame retardants, etc. The above-mentioned flame retardants may be used alone or in combination of two or more.

The inorganic phosphorus-based flame retardant is not particularly limited, but examples include red phosphorus; ammonium phosphates such as monoammonium phosphate, diammonium phosphate, triammonium phosphate, and ammonium polyphosphate; and phosphoric acid amides.

The above-mentioned organophosphorus flame retardants are not particularly limited, but include methyl acid phosphate, ethyl acid phosphate, isopropyl acid phosphate, dibutyl phosphate, monobutyl phosphate, butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, bis(2-ethylhexyl) phosphate, monoisodecyl acid phosphate, lauryl acid phosphate, tridecyl acid phosphate, and stearyl acid phosphate. phosphate esters such as isostearyl acid phosphate, oleyl acid phosphate, butyl pyrophosphate, tetracosyl acid phosphate, ethylene glycol acid phosphate, and (2-hydroxyethyl) methacrylate acid phosphate; diphenylphosphines such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and diphenylphosphine oxide; 10-(2,5-dihydroxyphenyl)-10H-9-oxa phosphorus-containing phenols such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(1,4-dioxynaphthalene)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, diphenylphosphinylhydroquinone, diphenylphosphinyl-1,4-dioxynaphthalene, 1,4-cyclooctylenephosphinyl-1,4-phenyldiol, and 1,5-cyclooctylenephosphinyl-1,4-phenyldiol; Examples include cyclic phosphorus compounds such as 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, and 10-(2,7-dihydroxynaphthyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide; and compounds obtained by reacting the above-mentioned phosphate esters, diphenylphosphine, or phosphorus-containing phenols with epoxy resins, aldehyde compounds, or phenol compounds.

The above-mentioned halogen-based flame retardants are not particularly limited, but include brominated polystyrene, bis(pentabromophenyl)ethane, tetrabromobisphenol A bis(dibromopropyl ether), 1,2-bis(tetrabromophthalimide), 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine, and tetrabromophthalic acid.

The amount of flame retardant used in the curable resin composition of this embodiment is preferably 0.1 to 50 parts by mass per 100 parts by mass of the combined total of the (A) and (B) components. When the flame retardant content is 0.1 parts by mass or more, flame retardancy can be more reliably imparted. On the other hand, when the flame retardant content is 50 parts by mass or less, flame retardancy can be imparted while maintaining dielectric properties. From the same perspective, the flame retardant content is more preferably 1 part by mass or more, and more preferably 30 parts by mass or less, per 100 parts by mass of the combined total of the (A) and (B) components.

<Filler>
Examples of fillers include organic fillers and inorganic fillers. Organic fillers have functions such as improving elongation and mechanical strength. 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 examples include polyamide particles.

The inorganic filler may be, but is not limited to, silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, zirconium tungstate phosphate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, carbon black, etc. Among these, silica is preferred. Examples of silica that can be used include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica.

The filler may also be surface-treated as needed. In this case, there are no particular limitations on the surface treatment agent that can be used, but examples include aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, organosilazane compounds, and titanate coupling agents. Specific examples of surface treatment agents include 3-glycidoxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, and hexamethyldisilazane. The fillers described above may be used alone or in combination of two or more.

The amount of filler used in the curable resin composition of this embodiment is preferably 0.5 to 95 parts by mass per 100 parts by mass of the combined total of the (A) and (B) components. When the filler content is 0.5 parts by mass or more, the filler's effects can be fully imparted. On the other hand, when the filler content is 95 parts by mass or less, deterioration of moldability due to an increase in the viscosity of the blend can be suppressed. From the same perspective, the filler content is more preferably 5 parts by mass or more, and more preferably 80 parts by mass or less, per 100 parts by mass of the combined total of the (A) and (B) components.

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

[Cured product]
The cured product of this embodiment is a cured product of the above-described curable resin composition. In other words, the cured product of this embodiment is obtained by irradiating the above-described curable resin composition with active energy rays to cure it. The cured product of this embodiment can function as an insulating material with excellent adhesion, low elasticity, dielectric properties, and elongation.

Examples of active energy rays include ultraviolet rays, electron beams, alpha rays, beta rays, gamma rays, and other ionizing radiation. Furthermore, when ultraviolet rays are used as active energy rays, irradiation may be carried out in an inert gas atmosphere such as nitrogen gas, or in an air atmosphere, in order to efficiently carry out the ultraviolet curing reaction.

Specific examples of ultraviolet light sources 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, as well as sunlight and LEDs. Of these, ultraviolet lamps are commonly used due to their practicality and economical efficiency.

The cumulative light dose of the active energy rays is not particularly limited, but is preferably 0.1 to 50 kJ/ ^m² , and more preferably 0.5 to 10 kJ/ ^m² . When the cumulative light dose is within the above range, the occurrence of uncured portions can be sufficiently prevented or suppressed. The irradiation of the active energy rays may be carried out in one step, or in two or more steps.

Another method for subjecting a curable resin composition to a curing reaction to obtain a cured product is, for example, heat curing. The heating temperature for heat curing is not particularly limited, but is preferably 100 to 300°C, and the heating time is preferably 1 to 24 hours.

[Goods]
The article of the present embodiment is characterized by having a coating film made of the above-described cured product. In such an article of the present embodiment, the coating film can function as an insulating material that has excellent adhesion, low elasticity, dielectric properties, and elongation.

The article of this embodiment is typically a printed wiring board or a substrate for a semiconductor package, with a solder resist film (the coating film described above) formed in appropriate locations on the surface layer.

The present invention will be explained in more detail below using examples, but the present invention is not limited to the following examples in any way.

In the examples, the instruments and conditions used to measure various properties are as follows:

(GPC measurement)
Measurements were performed using the following measuring equipment and under the following conditions to obtain GPC charts of the diphenyl isophthalate derivatives and aromatic ester compounds obtained in the following Synthesis Examples and Examples. From the results of the GPC charts, it was confirmed that the target products (diphenyl isophthalate derivatives and aromatic ester compounds) were produced, based on the decrease and disappearance of the raw material peaks.
Measuring device: Tosoh Corporation "HLC-8320 GPC"
Column: Tosoh Corporation guard column "HXL-L" + Tosoh Corporation "TSK-GEL G2000HXL" + Tosoh Corporation "TSK-GEL G2000HXL" + Tosoh Corporation "TSK-GEL G3000HXL" + Tosoh Corporation "TSK-GEL G4000HXL"
Detector: RI (differential refractometer)
Data processing: Tosoh Corporation's "GPC Workstation EcoSEC-WorkStation"
Measurement conditions: column temperature 40°C
Developing solvent: Tetrahydrofuran
Flow rate: 1.0 ml/min. Standard: The following monodisperse polystyrene with known molecular weight was used in accordance with the measurement manual for the "GPC Workstation EcoSEC-Workstation."
(Polystyrene used)
"A-500" manufactured by Tosoh Corporation
"A-1000" manufactured by Tosoh Corporation
Tosoh Corporation "A-2500"
Tosoh Corporation "A-5000"
"F-1" manufactured by Tosoh Corporation
"F-2" manufactured by Tosoh Corporation
Tosoh Corporation "F-4"
"F-10" manufactured by Tosoh Corporation
"F-20" manufactured by Tosoh Corporation
Tosoh Corporation "F-40"
"F-80" manufactured by Tosoh Corporation
Tosoh Corporation "F-128"
Sample: A tetrahydrofuran solution (50 μl) of 1.0% by mass (solid content equivalent) of the diphenyl isophthalate derivatives and aromatic ester compounds obtained in the Synthesis Examples and Examples was filtered through a microfilter and used.

Synthesis Example 1: Synthesis of Isophthalic Acid Diphenyl Derivative (a'-1) 808.0 parts by mass of isophthalic acid chloride as component (a1) and 4140.0 parts by mass of toluene were charged into a flask equipped with a thermometer, dropping funnel, condenser, fractionating column, and stirrer, and the system was purged with nitrogen under reduced pressure to allow dissolution. Next, 864.0 parts by mass of o-cresol as component (a2) was charged, and the system was purged with nitrogen to allow dissolution. Thereafter, 2.07 parts by mass of tetrabutylammonium bromide was dissolved, and while purging with nitrogen gas, the system was controlled to 60°C or less, and 1648.0 parts by mass of a 20% aqueous sodium hydroxide solution was added dropwise over 3 hours. Stirring was then continued under these conditions for 1 hour. After completion of the reaction, the mixture was allowed to stand for separation, and the aqueous layer was removed. Furthermore, water was added to the toluene layer in which the reactant was dissolved, and the mixture was stirred and mixed for approximately 15 minutes, and the mixture was allowed to stand for separation, and the aqueous layer was removed. This operation was repeated until the pH of the aqueous layer reached 7. Thereafter, water and toluene were removed by decanting, yielding a crystalline compound (intermediate product (a')), a diphenyl isophthalate derivative (a'-1). FIG. 1 shows a GPC chart of the obtained diphenyl isophthalate derivative (a'-1).

Synthesis Example 2: Synthesis of aromatic ester compound (A-1) A flask equipped with a thermometer, a dropping funnel, a condenser, a fractionating column, and a stirrer was charged with 200 parts by mass of polybutadiene having hydroxyl groups at both ends as component (a3) (trade name: G-1000, manufactured by Nippon Soda Co., Ltd., hydroxyl value: 74.2 mg KOH/g, hydroxyl equivalent: 756 g/eq), 91.5 parts by mass of the diphenyl isophthalate derivative (a′-1) as intermediate product (a′) obtained in Synthesis Example 1, 0.29 parts by mass of 1,8-diazabicyclo[5,4,0]-undecene-7 (hereinafter abbreviated as “DBU”), and 4-[[4,6-bis(octylthio)-1,3,5-triazin-2-yl]amino]-1,6-di-tert-butylphenol (trade name: IRGANOX, manufactured by BASF Japan Ltd.). 0.29 parts by mass of 565) was charged, and the system was purged with nitrogen under reduced pressure, then the temperature was raised to 180°C and stirred until the reaction was complete. The completion point of the reaction was confirmed by GPC. Thereafter, o-cresol was removed by distillation under reduced pressure to obtain aromatic ester compound (A-1). The functional group equivalent of the obtained aromatic ester compound (A-1) was 995 g/eq based on the charge ratio, and the average repeat number p ¹¹ (see general formula (1) above) was 1 based on the charge ratio. The structure of the obtained aromatic ester compound (A-1) is shown below.

Synthesis Example 3: Synthesis of aromatic ester compound (A-2) [0046] The same procedure as in Synthesis Example 2 was carried out, except that IRGANOX 565 was removed, 200.0 parts by mass of polycarbonate polyol (Kuraray Co., Ltd., product name: C-2090, hydroxyl value: 56.8 mg KOH/g, hydroxyl equivalent: 988 g/eq) was used instead of G-1000, the amount of diphenyl isophthalate derivative (a'-1) obtained in Synthesis Example 2 was changed from 91.5 parts by mass to 70.0 parts by mass, and DBU was changed from 0.29 parts by mass to 0.27 parts by mass, to obtain aromatic ester compound (A-2). The functional group equivalent of this aromatic ester compound (A-2) was 1194 g/eq based on the feed ratio, and the average repeat number p ¹¹ (see general formula (1) above) was 1 based on the feed ratio. The structure of the obtained aromatic ester compound (A-2) was a structure satisfying the above general formula (1).

(Synthesis Example 4): Synthesis of aromatic ester compound (A-3) In Synthesis Example 2, IRGANOX 565 was removed, and instead of G-1000, polyester polyol (manufactured by Croda Japan Co., Ltd., trade name: PRIPLAST 1837LQGD, hydroxyl value 110 mg KOH/g, hydroxyl equivalent: 510 g/eq) was used at 50.0 parts by mass, the amount of isophthalic acid diphenyl derivative (a'-1) obtained in Synthesis Example 2 was changed from 91.5 parts by mass to 34.0 parts by mass, and DBU was changed from 0.29 parts by mass to 0.084 parts by mass, except that the same operation as in Synthesis Example 2 was performed to obtain aromatic ester compound (A-3). The functional group equivalent of this aromatic ester compound (A-3) was 748 g/eq from the feed ratio, and the average repeat number p ¹¹ (see general formula (1) above) was 1 from the feed ratio. The structure of the obtained aromatic ester compound (A-3) was a structure satisfying the above general formula (1).

(Synthesis Example 5: Production of epoxy resin (B-1) 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 bisphenol A epoxy resin (DIC Corporation "EPICLON 850CRP," epoxy equivalent 173 g/eq. hereinafter referred to as "bisphenol A epoxy resin (1)") as the epoxy resin (b1), and 0.21 parts by mass of dibutylhydroxytoluene as an antioxidant and 0.21 parts by mass of methoquinone as a thermal polymerization inhibitor were added. Then, 72 parts by mass of acrylic acid as the unsaturated monobasic acid (b2) and 0.21 parts by mass of triphenylphosphine were added, and an esterification reaction was carried out at 100 ° C. for 10 hours while blowing air. Next, after confirming that the acid value was 1 mg KOH/g or less, 0.21 parts by mass of oxalic acid was added, and the mixture was stirred at 70 ° C. for 3 hours to obtain an epoxy resin (epoxy acrylate resin) (B-1) having a polymerizable unsaturated group. The epoxy equivalent of this epoxy acrylate resin (B-1) was 450 g/eq. The number of moles of acid groups in the acrylic acid relative to 1 mole of epoxy groups in the bisphenol A epoxy resin (1) was 0.5.

(Synthesis Example 6: Production of epoxy resin (B-2) having a polymerizable unsaturated group)
A flask equipped with a thermometer, stirrer, and reflux condenser was charged with 346 parts by mass of bisphenol A epoxy resin (1) as the epoxy resin (b1), and 0.18 parts by mass of dibutylhydroxytoluene as an antioxidant and 0.18 parts by mass of methoquinone as a thermal polymerization inhibitor were added. Then, 22 parts by mass of acrylic acid as the unsaturated monobasic acid (b2) and 0.18 parts by mass of triphenylphosphine were added, and the esterification reaction was carried out at 100 ° C. for 5 hours while blowing in air. Next, after confirming that the acid value was 1 mg KOH/g or less, 0.18 parts by mass of oxalic acid was added, and the mixture was stirred at 70 ° C. for 3 hours to obtain an epoxy resin (epoxy acrylate resin) (B-2) having a polymerizable unsaturated group. The epoxy equivalent of this epoxy acrylate resin (B-2) was 241 g/eq. Furthermore, the number of moles of acid groups in the acrylic acid per mole of epoxy groups in the bisphenol A epoxy resin (1) was 0.15.

(Synthesis Example 7: Production of epoxy resin (B-3) having polymerizable unsaturated group)
A flask equipped with a thermometer, stirrer, and reflux condenser was charged with 346 parts by mass of bisphenol A epoxy resin (1) as the epoxy resin (b1), and 0.19 parts by mass of dibutylhydroxytoluene as an antioxidant and 0.19 parts by mass of methoquinone as a thermal polymerization inhibitor were added. Then, 43 parts by mass of acrylic acid as the unsaturated monobasic acid (b2) and 0.19 parts by mass of triphenylphosphine were added, and the esterification reaction was carried out at 100°C for 8 hours while blowing in air. Next, after confirming that the acid value was 1 mgKOH/g or less, 0.19 parts by mass of oxalic acid was added, and the mixture was stirred at 70°C for 3 hours to obtain an epoxy resin (epoxy acrylate resin) (B-3) having a polymerizable unsaturated group. The epoxy equivalent of this epoxy acrylate resin (B-3) was 301 g/eq. Furthermore, the number of moles of acid groups in the acrylic acid per mole of epoxy groups in the bisphenol A epoxy resin (1) was 0.3.

(Synthesis Example 8: Production of epoxy resin (B-4) having polymerizable unsaturated group)
A flask equipped with a thermometer, stirrer, and reflux condenser was charged with 346 parts by mass of bisphenol A epoxy resin (1) as the epoxy resin (b1), and 0.22 parts by mass of dibutylhydroxytoluene as an antioxidant and 0.22 parts by mass of methoquinone as a thermal polymerization inhibitor were added. Then, 101 parts by mass of acrylic acid as the unsaturated monobasic acid (b2) and 0.44 parts by mass of triphenylphosphine were added, and an esterification reaction was carried out at 100°C for 10 hours while blowing in air. Next, after confirming that the acid value was 1 mgKOH/g or less, 0.22 parts by mass of oxalic acid was added, and the mixture was stirred at 70°C for 3 hours to obtain an epoxy resin (epoxy acrylate resin) (B-4) having a polymerizable unsaturated group. The epoxy equivalent of this epoxy acrylate resin (B-4) was 785 g/eq. Furthermore, the number of moles of acid groups in the acrylic acid per mole of epoxy groups in the bisphenol A epoxy resin (1) was 0.7.

(Synthesis Example 9: Production of epoxy resin (B-5) having polymerizable unsaturated group)
A flask equipped with a thermometer, stirrer, and reflux condenser was charged with 346 parts by mass of bisphenol A epoxy resin (1) as the epoxy resin (b1), and 0.23 parts by mass of dibutylhydroxytoluene as an antioxidant and 0.23 parts by mass of methoquinone as a thermal polymerization inhibitor were added. Then, 122 parts by mass of acrylic acid as the unsaturated monobasic acid (b2) and 0.46 parts by mass of triphenylphosphine were added, and the esterification reaction was carried out at 100°C for 20 hours while blowing in air. Next, after confirming that the acid value was 1 mgKOH/g or less, 0.23 parts by mass of oxalic acid was added, and the mixture was stirred at 70°C for 3 hours to obtain an epoxy resin (epoxy acrylate resin) (B-5) having a polymerizable unsaturated group. The epoxy equivalent of this epoxy acrylate resin (B-5) was 1603 g/eq. Furthermore, the number of moles of acid groups in the acrylic acid relative to 1 mole of epoxy groups in the bisphenol A epoxy resin (1) was 0.85.

(Synthesis Example 10: Production of epoxy resin (B-6) having polymerizable unsaturated group)
A flask equipped with a thermometer, stirrer, and reflux condenser was charged with 282 parts by mass of a naphthalene-type epoxy resin (Epiclon 4032D manufactured by DIC Corporation, epoxy equivalent 141 g/eq. hereinafter referred to as "naphthalene-type epoxy resin (1)") as the epoxy resin (b1). 0.18 parts by mass of dibutylhydroxytoluene as an antioxidant and 0.18 parts by mass of methoquinone as a thermal polymerization inhibitor were added. Then, 72 parts by mass of acrylic acid as the unsaturated monobasic acid (b2) and 0.18 parts by mass of triphenylphosphine were added, and an esterification reaction was carried out at 100°C for 10 hours while blowing in air. Next, after confirming that the acid value was 1 mgKOH/g or less, 0.18 parts by mass of oxalic acid was added, and the mixture was stirred at 70°C for 3 hours to obtain an epoxy resin (epoxy acrylate resin) (B-6) having a polymerizable unsaturated group. The epoxy equivalent of this epoxy acrylate resin (B-6) was 388 g/eq. The number of moles of acid groups in the acrylic acid relative to 1 mole of epoxy groups in the naphthalene-type epoxy resin (1) was 0.50.

(Comparative Synthesis Example 1: Synthesis of phenolic hydroxyl group-containing resin (a'-2))
A flask equipped with a thermometer and a stirrer was charged with 127 parts by mass of diglycidyl ether of 1,6-hexanediol (manufactured by DIC Corporation: trade name: SR-16HL, epoxy equivalent: 127 g/eq) and 228 parts by mass of bisphenol A (hydroxyl equivalent: 114 g/eq), and the temperature was raised to 140 °C over 30 minutes. Next, 1.8 parts by mass of a 4% aqueous sodium hydroxide solution was charged into the flask, and the temperature inside the flask was raised to 150 °C over 30 minutes, followed by a further reaction at 150 °C for 5 hours. Thereafter, a neutralizing amount of sodium phosphate was added to the flask, yielding a phenolic hydroxyl group-containing resin (a'-2). The production of the phenolic hydroxyl group-containing resin (a'-2) was confirmed from a GPC chart (not shown), and the hydroxyl group equivalent of the resin (a'-2) was confirmed to be 300 g/eq.

(Comparative Synthesis Example 2: Synthesis of aromatic ester compound (A-4))
A flask equipped with a thermometer, dropping funnel, condenser, fractionating column, and stirrer was charged with 300 parts by mass of the phenolic hydroxyl-containing resin (a'-2) (hydroxyl equivalent: 300 g/eq) obtained in Comparative Synthesis Example 1 and 1,212 parts by mass of methyl isobutyl ketone (hereinafter abbreviated as "MIBK"). The system was purged with nitrogen under reduced pressure to dissolve the phenolic hydroxyl-containing resin (a'-2). Next, 140.5 parts by mass (1.0 mol) of benzoyl chloride was charged into the flask. Then, while purging with nitrogen gas, the system was controlled to 60°C or below, and 216 parts by mass of a 20% aqueous sodium hydroxide solution was added dropwise over 3 hours. Stirring was continued under the above conditions for 1 hour. After completion of the reaction, the mixture was allowed to stand for separation, and the aqueous layer was removed. Water was then added to the MIBK phase containing the dissolved reactants, and the mixture was stirred and mixed for approximately 10 minutes. The mixture was then allowed to stand for separation, and the aqueous layer was removed. This operation was repeated until the pH of the aqueous layer reached 7. Thereafter, water was removed by decanting, and then MIBK was removed by dehydration under reduced pressure to obtain aromatic ester compound (A-4). The functional group equivalent of the obtained aromatic ester (A-4) was 404 g/eq based on the charge ratio.

(Example 1: Preparation of curable resin composition (1))
20 parts by mass of the aromatic ester compound (A-1) obtained in Synthesis Example 2, 80 parts by mass of the resin (B-1) having a polymerizable unsaturated group obtained in Synthesis Example 5, 2 parts by mass of a photopolymerization initiator ("Omnirad 907" manufactured by IGM Resins), 1.6 parts by mass of 2-ethyl-4-methylimidazole, and 0.4 parts by mass of 4-dimethylaminopyridine were mixed to obtain a curable resin composition (1).

(Examples 2 to 13: Preparation of curable resin compositions (2) to (13))
Curable resin compositions (2) to (13) were obtained in the same manner as in Example 1 using the blending ratios shown in Table 1.

(Comparative Example 1: Preparation of curable resin composition (C1))
20 parts by mass of the aromatic ester compound (A-4) obtained in Comparative Synthesis Example 2, 80 parts by mass of the epoxy resin (B-1) having a polymerizable unsaturated group obtained in Synthesis Example 5, 2 parts by mass of a photopolymerization initiator (Omnirad 907 manufactured by IGM Resins), 1.6 parts by mass of 2-ethyl-4-methylimidazole, and 0.4 parts by mass of 4-dimethylaminopyridine were mixed to obtain a curable resin composition (C1).

(Comparative Example 2: Preparation of curable resin composition (C2))
A curable resin composition (C1) was obtained by mixing 80 parts by mass of the aromatic ester compound (A-1) obtained in Synthesis Example 2, 20 parts by mass of an acrylate monomer, 2 parts by mass of a photopolymerization initiator (Omnirad 907 manufactured by IGM Resins), 0.4 parts by mass of 2-ethyl-4-methylimidazole, and 1.64 parts by mass of 4-dimethylaminopyridine.

The following evaluations were carried out using the curable resin compositions (1) to (13), as well as (C1) and (C2) obtained in the above examples and comparative examples.

[Method for evaluating adhesion]
Adhesion was evaluated by measuring peel strength. Specifically, the curable resin compositions obtained in the Examples and Comparative Examples were applied to copper foil (electrolytic copper foil "F2-WS" 18 μm, manufactured by Furukawa Sangyo Co., Ltd.) using a 50 μm applicator, irradiated with 10 kJ/ ^m2 of ultraviolet light using a metal halide lamp, and then heated at 160°C for 1 hour. The cured product was peeled from the copper foil to obtain test piece 1 (cured product). This test piece 1 was cut into 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., peel speed 50 mm/min). A higher value indicates better adhesion.

[Method for measuring elastic modulus]
Using the same test piece 1 (cured product) as above, the elastic modulus (MPa) was measured at 2 mm/min in accordance with JIS K 7181. A smaller value indicates lower elasticity.

[Method for measuring elongation]
The elongation was measured based on a tensile test. Specifically, the same test piece 1 (cured product) as above was cut into a size of 10 mm x 80 mm, and a tensile test was performed on the test piece 1 using a precision universal testing machine autograph "AG-IS" manufactured by Shimadzu Corporation under the following measurement conditions. The elongation (%) until the test piece broke was measured.
Measurement conditions: temperature 23°C, humidity 50%, distance between gauge lines 20mm, distance between fulcrums 20mm, tensile speed 10mm/min

[Method for measuring dielectric constant]
The curable resin compositions obtained in each example and comparative example were applied to a glass substrate using an applicator to a film thickness of 50 μm, and then dried at 80°C for 30 minutes. Next, the composition was irradiated with 10 kJ/ ^m2 ultraviolet light using a metal halide lamp, and then heated at 160°C for 1 hour to obtain a cured coating film. The cured coating film was then peeled off from the glass substrate to obtain a cured product. The specimens were then stored in a room at a temperature of 23°C and a humidity of 50% for 24 hours to prepare test specimens, and the dielectric constant of the test specimens at 1 GHz was measured by a cavity resonance method using a Network Analyzer E8362C manufactured by Agilent Technologies, Inc.

[Method for measuring dielectric loss tangent]
The curable resin compositions obtained in each example and comparative example were applied to a glass substrate using an applicator to a film thickness of 50 μm, and then dried at 80°C for 30 minutes. Next, the composition was irradiated with 10 kJ/ ^m2 ultraviolet light using a metal halide lamp, and then heated at 160°C for 1 hour to obtain a cured coating film. The cured coating film was then peeled off from the glass substrate to obtain a cured product. The specimens were then stored in a room at 23°C and 50% humidity for 24 hours to prepare test pieces, and the dielectric loss tangent of the test pieces at 1 GHz was measured by the cavity resonance method using a Network Analyzer E8362C manufactured by Agilent Technologies, Inc.

The compositions and evaluation results of the curable resin compositions (1) to (13) obtained in Examples 1 to 13 and the curable resin compositions (C1) and (C2) obtained in Comparative Examples 1 and 2 are shown in Table 1.

Table 1 shows that the resin compositions of the examples have a high level of balance in adhesion, low elasticity, dielectric properties, and elongation compared to the comparative examples.

The present invention provides a resin composition that can be used to obtain an insulating material with excellent adhesion, low elasticity, dielectric properties, and elongation. The present invention also provides a curable resin composition containing such a resin composition, a cured product thereof, and an article using such a cured product.

Claims (9)

A resin composition having a polymerizable unsaturated group, comprising an aromatic ester compound (A) and an epoxy resin (B) having a polymerizable unsaturated group,
the aromatic ester compound (A) is a compound obtained by reacting an aromatic polycarboxylic acid, an acid halide thereof and/or an ester thereof (a1), a monohydroxyaromatic compound (a2), and a polyhydric alcohol compound (a3) as essential reaction raw materials;
the hydroxyl group equivalent of the polyhydric alcohol compound (a3) is 270 g/eq or more,
the polyhydric alcohol compound (a3) is at least one selected from the group consisting of hydrocarbon polyols, polycarbonate polyols, and polyester polyols;
the epoxy resin (B) having a polymerizable unsaturated group is a resin containing an epoxy resin (b1) and an unsaturated monobasic acid (b2) as essential reaction raw materials,
the epoxy resin (B) having a polymerizable unsaturated group is a resin having an epoxy group and a (meth)acryloyl group;
A resin composition having a polymerizable unsaturated group, characterized in that: The aromatic ester compound (A) is represented by the following general formula (1):
[In the above general formula (1), ^Q11 and ^Q12 each independently represent a group derived from the aromatic polycarboxylic acid, its acid halide and/or its ester (a1); ^Ar11 and ^Ar12 each independently represent a group derived from the monohydroxy aromatic compound (a2); A each independently represent a group derived from the polyhydric alcohol compound (a3); and ^p11 represents an average repeat number of 0.01 or more.]. The resin composition having a polymerizable unsaturated group according to claim 1, Ar ¹¹ and Ar ¹² in the general formula (1) each independently represent the following general formula (2) or (3):
[In the general formula (2) and the general formula (3), * represents a bond to the oxygen atom bonding to Ar ¹¹ or Ar ¹² in the general formula (1),
R ²¹ and R ³¹ each independently represent a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, or an aralkyl group; k ²¹ represents an integer of 0 to 7; and k ³¹ represents an integer of 0 to 5. 4. The resin composition having a polymerizable unsaturated group according to claim 1, wherein the number of moles of acid groups in the unsaturated monobasic acid (b2) relative to 1 mole of epoxy groups in the epoxy resin ( b1 ) is in the range of 0.2 to 0.8. 5. The resin composition having a polymerizable unsaturated group according to claim 1, wherein a mass ratio [(A)/(B)] of solid contents of the aromatic ester compound (A) to the epoxy resin ( B ) having a polymerizable unsaturated group is in the range of 10/90 to 90/10. A curable resin composition comprising the resin composition having a polymerizable unsaturated group according to any one of claims 1 to 5 and a photopolymerization initiator. The curable resin composition according to claim 6 , further comprising a (meth)acrylate monomer. A cured product of the curable resin composition according to claim 6 or 7 . An article having a coating film comprising the cured product according to claim 8 .