JP7838366B2 - Resin composition, cured product, insulating material, and resist member - Google Patents

Description

This invention relates to resin compositions, cured products, insulating materials, and resist members.

Solder resist is widely used as an insulating material to prevent solder from adhering to areas other than the mounting area when soldering electronic components onto printed circuit boards, and to form a coating that semi-permanently prevents oxidation or corrosion of the wiring. Among the techniques for forming patterns on such solder resist, the photoresist method, which can accurately form fine patterns, is one example. In particular, due to environmental considerations, the alkali-developable liquid photoresist method has become the mainstream.

Furthermore, in recent years, printed circuit boards have been steadily becoming smaller, more multilayered, and single-board in order to achieve higher density of electronic components, and the mounting method has also shifted to surface mount technology (SMT). Therefore, there is an increasing demand for solder resist films that are finer, have high Tg, high resolution, high precision, and high reliability.

Here, since the resist film requires various properties, including heat resistance, it is crucial to manufacture it using appropriate materials that meet these properties. In this regard, maleimide resin is one resin that tends to exhibit excellent heat resistance in its cured form, and there is room for consideration regarding its application to the liquid photoresist method.

Conventionally, 4,4'-diphenylmethanebismaleimide type compounds are widely known as maleimide resins (see, for example, Patent Document 1).
Furthermore, 2,2-bis[4-(4-maleimidephenoxy)phenyl]propane-type compounds are also known as maleimide resins that are relatively easy to handle (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2-269716 Japanese Patent Application Publication No. 6-128225

However, when the aforementioned 4,4'-diphenylmethanebismaleimide-type maleimide resin is used in the photoresist method, problems arise such as insufficient photosensitivity and developability, as well as turbidity during compounding, resulting in poor appearance of the resulting cured coating film. In addition, further improvement in heat resistance is required.
Furthermore, the aforementioned 2,2-bis[4-(4-maleimidephenoxy)phenyl]propane-type maleimide resin did not meet current market demands in terms of various properties of the cured product, including heat resistance.

Therefore, the present invention aims to provide a resin composition that exhibits high photosensitivity and developability, and that can produce excellent heat resistance and coating appearance in the resulting cured product (cured coating film). Furthermore, the present invention aims to provide a cured product, an insulating material, and a resist member obtained using the said resin composition.

The inventors, in order to solve the above problems, conducted extensive research and discovered that a resin composition containing a specific maleimide resin and a resin having acidic groups and polymerizable unsaturated groups exhibits high photosensitivity and developability, and that the resulting cured product (cured coating film) exhibits excellent heat resistance and coating film appearance. This led to the completion of the present invention.

The resin composition of the present invention is a resin composition comprising a maleimide resin (A) and a resin (B) having acidic groups and polymerizable unsaturated groups,
The maleimide resin (A) contains the following general formula (1) in one molecule:
The first aromatic ring-maleimide skeleton shown by and the following general formula (2):
The resin composition is characterized by comprising a maleimide compound (a) having a second aromatic ring-maleimide skeleton represented by [wherein formulas (1) and (2), ^R1 to ^R4 each independently represent hydrogen, a methyl group, or an ethyl group, ^Ar1 and ^Ar2 each independently represent an aromatic ring which may have one or more substituents, and * represents a bond from the aromatic ring to another site, provided that ^Ar1 and ^Ar2 differ from each other in at least one of the type of substituent, the number of substituents, and the position of the substituents].

According to the present invention, it is possible to provide a resin composition that exhibits high photosensitivity and developability, and that can produce excellent heat resistance and coating appearance in the resulting cured product (cured coating film). Furthermore, according to the present invention, it is possible to provide cured products, insulating materials, and resist members obtained using the resin composition.

This is a GPC chart of the maleimide resin (A-1) obtained in Synthesis Example 1. This is a GPC chart of the maleimide resin (A-2) obtained in Synthesis Example 2. This is a GPC chart of the maleimide resin (A-3) obtained in Synthesis Example 3. This is a GPC chart of the maleimide resin (A-4) obtained in Synthesis Example 4. This is a GPC chart of the maleimide resin (A-5) obtained in synthesis example 5. This is a GPC chart of the maleimide resin (A-6) obtained in synthesis example 6.

(Explanation of terms)
Unless otherwise specified in this specification, the following definitions of terms apply.

In this specification, examples of "aryl group" include phenyl group, naphthyl group, phenalenyl group, phenantrenyl group, anthryl group, azlenyl group, indenyl group, indanyl group, tetralinyl group, and the like. Furthermore, the hydrogen atoms of the aromatic ring within the "aryl group" may be substituted with, for example, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a halogen atom.

In this specification, "aralkyl group" refers to, for example, a benzyl group, a diphenylmethyl group, a biphenyl group, a naphthylmethyl group, and the like.

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

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

In this specification, "halogen atoms" include, for example, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, and the like.

In this specification, examples of "alkylene group" include methylene group, ethylene group, propylene group, 1-methylmethylene group, 1,1-dimethylmethylene group, 1-methylethylene group, 1,1-dimethylethylene group, 1,2-dimethylethylene group, propylene group, butylene group, 1-methylpropylene group, 2-methylpropylene group, pentylene group, hexylene group, heptylene group, octylene group, nonylene group, decylene group, undecylene group, dodecylene group, and the like.

In this specification, "monovalent hydrocarbon group" refers, for example, to the alkyl group described above. In the alkyl group, one or more _-CH2- atoms may be substituted with -O- or -S- atoms such that they are not adjacent to each other, or one or more _-CH2 - _CH2- atoms may be substituted with -CH=CH- atoms such that they are not adjacent to each other.

In this specification, "divalent hydrocarbon group" refers to, for example, the alkylene group described above. In the alkylene group, one or more _-CH2- atoms may be substituted with -O- or -S- atoms such that they are not adjacent to each other, or one or more _-CH2 - _CH2- atoms may be substituted with -CH= _CH2- atoms such that they are not adjacent to each other.

In this specification, "maleimide resin" means a resin having a maleimide group. Furthermore, in this specification, "maleimide compound" means a compound having a maleimide group.

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

The following describes in detail embodiments of the present invention (which may be referred to as "these embodiments"). However, the present invention is not limited to the following description and can be implemented in various ways within the scope of its gist.

[Resin composition]
The resin composition of this embodiment is a resin composition containing a maleimide resin (A) and a resin (B) having an acid group and a polymerizable unsaturated group (hereinafter also simply referred to as "resin (B)"). The maleimide resin (A) contains the following general formula (1) in one molecule:
The first aromatic ring-maleimide skeleton shown by and the following general formula (2):
The compound comprises a maleimide compound (a) having a second aromatic ring-maleimide skeleton represented by . Herein, in formulas (1) and (2), ^R1 to ^R4 each independently represent hydrogen, a methyl group, or an ethyl group, ^Ar1 and ^Ar2 each independently represent an aromatic ring which may have one or more substituents, and * represents a bond from the aromatic ring to another site, provided that ^Ar1 and ^Ar2 differ from each other in at least one of the type of substituent, the number of substituents, and the position of the substituents.
Such resin compositions exhibit high light sensitivity and developability, and the resulting cured product (cured coating) can exhibit excellent heat resistance and coating appearance.

Furthermore, developability relates to the contrast between the exposed and unexposed areas, and "low developability" means that the above contrast is insufficient. One reason for low developability is that when a curable resin composition applied to a substrate is dried and then exposed, the unexposed areas remain after (alkaline) development due to heating during drying, which reduces the contrast. Therefore, in this invention, as described in the examples below, developability is evaluated by the drying control range (minutes). This drying control range defines the range of drying conditions (drying time) in which development defects are unlikely to occur due to coating drying, etc. Therefore, if development residue is unlikely to occur even if the drying time is extended (i.e., if the drying control range is large), it is considered that high developability will be exhibited.

The content of maleimide resin (A) in the total amount (100% by mass) of the resin composition of this embodiment is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and preferably 80% by mass or less, more preferably 50% by mass or less, and even more preferably 30% by mass or less, from the viewpoint of improving light sensitivity, developability, heat resistance, and coating film appearance in a balanced manner.

Furthermore, the content of resin (B) having acidic groups and polymerizable unsaturated groups in the total amount (100% by mass) of the resin composition of this embodiment is preferably 20% by mass or more, more preferably 40% by mass or more, even more preferably 50% by mass or more, preferably 99% 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 photosensitivity, developability, heat resistance, and coating film appearance in a balanced manner.

In the resin composition of this embodiment, the mass ratio of solids between the maleimide resin (A) and the resin having acidic groups and polymerizable unsaturated groups (B) [(A)/(B)] is preferably in the range of 1/100 to 100/100, from the viewpoint of improving photosensitivity, developability, heat resistance, and coating film appearance in a well-balanced manner. Similarly, from the same viewpoint, the above mass ratio [(A)/(B)] is more preferably 10/90 or higher, and more preferably 40/60 or lower.

The resin composition of this embodiment may consist substantially of maleimide resin (A) and resin (B) alone. Alternatively, the resin composition of this embodiment may further contain a compound having a polymerizable unsaturated group in addition to maleimide resin (A) and resin (B). Furthermore, the resin composition of this embodiment may further contain a photopolymerization initiator in addition to maleimide resin (A) and resin (B). Furthermore, the resin composition of this embodiment may further contain optional additives as optional components. Moreover, the resin composition of this embodiment may contain unavoidable impurities in addition to maleimide resin (A), resin (B), a compound having a polymerizable unsaturated group, a photopolymerization initiator, and optional additives, as long as the effects of this disclosure are not impaired.
The total content of maleimide resin (A) and resin (B) in the total amount (100% by mass) of the resin composition of this embodiment is preferably 40% by mass or more, more preferably 50% by mass or more, preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less, from the viewpoint of improving light sensitivity, developability, heat resistance and coating film appearance in a balanced manner.

The following will describe, in order, the maleimide resin (A), the resin having acidic groups and polymerizable unsaturated groups (B), the compound having polymerizable unsaturated groups, the photopolymerization initiator, and the optional additives.

(Maleimide resin (A))
Maleimide resin (A) is one of the essential components in the resin composition of this embodiment. As described above, maleimide resin (A) is a resin containing at least maleimide compound (a). Maleimide compound (a) contains the following general formula (1) in one molecule:
The first aromatic ring-maleimide skeleton shown by and the following general formula (2):
The maleimide compound has a second aromatic ring-maleimide skeleton represented by . Here, in formulas (1) and (2), ^R1 to ^R4 each independently represent hydrogen, a methyl group, or an ethyl group, ^Ar1 and ^Ar2 (hereinafter sometimes collectively referred to as "Ar") each independently represent an aromatic ring which may have one or more substituents, and * represents a bond from the aromatic ring to another site, provided that ^Ar1 and ^Ar2 differ from each other in at least one of the type of substituent, the number of substituents, and the position of the substituents (hereinafter sometimes collectively referred to as "substituent form"). Maleimide compound (a) may be a single compound or a combination of two or more compounds.
By using a maleimide compound (a) having two or more aromatic ring-maleimide skeletons with different substituent configurations, the crystallinity of the maleimide alone is reduced, and the compatibility of each component in the resin composition is improved. As a result, the photosensitivity, developability, heat resistance, and coating film appearance can be improved.

Furthermore, the maleimide resin (A) may contain, in addition to the maleimide compound (a), other maleimide compounds (for example, maleimide compounds having two or more aromatic ring-maleimide skeletons in which all substituents are identical).
Furthermore, while formulas (1) and (2) show only one * (bond from the aromatic ring to another part) for convenience, the number of such bonds * may be two or three.

In formulas (1) and (2), ^R1 to ^R4 are each independently hydrogen, a methyl group, or an ethyl group. From the viewpoint of the reactivity of maleimide, it is preferable that they be hydrogen or a methyl group, and more preferably that they are all hydrogen. Furthermore, from the viewpoint of ease of manufacture, it is preferable that the combination of ^R1 and ^R2 is the same as the combination of ^R3 and ^R4 .

Examples of aromatic rings for ^Ar1 and ^Ar2 in formulas (1) and (2) include benzene, naphthalene, anthracene, etc. The aromatic rings for ^Ar1 and ^Ar2 may be the same or different.

Examples of substituents that the aromatic rings of ^Ar1 and ^Ar2 may have include aliphatic hydrocarbon groups, alkyloxy groups, alkenyloxy groups, alkynyloxy groups, halogen atoms, aryl groups, aralkyl groups, hydroxyl groups, and the like.

The above aliphatic hydrocarbon group may be linear, branched, or cyclic, and may have unsaturated bonds in its structure. Specific examples of the above aliphatic hydrocarbon group include methyl, ethyl, vinyl, propyl, allyl, butyl, pentyl, hexyl, cyclohexyl, heptyl, octyl, and nonyl groups.
Examples of the alkyloxy groups mentioned above include methoxy groups, ethoxy groups, propyloxy groups, and butoxy groups.
Examples of the above-mentioned alkenyloxy group include allyloxy groups.
Examples of the halogen atoms mentioned above include fluorine atoms, chlorine atoms, and bromine atoms.
Examples of the aryl groups mentioned above include phenyl groups, naphthyl groups, anthryl groups, and groups in which the above aliphatic hydrocarbon groups, alkyloxy groups, or halogen atoms are substituted on the aromatic core of these groups.
Examples of the above-mentioned aralkyl groups include benzyl groups, phenylethyl groups, naphthylmethyl groups, naphthylethyl groups, and groups in which an alkyl group, or the alkyloxy group or halogen atom mentioned above, is substituted on the aromatic core of these groups.
In particular, it is preferable that both the ^Ar1 and ^Ar2 aromatic rings have an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and more preferably that they have an alkyl group having 1 to 4 carbon atoms (such as a methyl group, ethyl group, propyl group, or butyl group).

Furthermore, the number of substituents that the ^Ar1 and ^Ar2 aromatic rings may have can be 0, 1, 2, 3, or 4, and if the aromatic ring is not benzene, it may have 5 or more substituents. If there are two or more substituents, they may be the same or different. In particular, it is preferable that both the ^Ar1 and ^Ar2 aromatic rings have at least one substituent.

Furthermore, possible positions of substituents on the ^Ar1 and ^Ar2 aromatic rings include the carbon adjacent to the carbon to which the maleimide group is bonded (i.e., the ortho position in the case of benzene), the carbon two positions away from the carbon to which the maleimide group is bonded (i.e., the meta position in the above case), and the carbon three positions away from the carbon atom to which the maleimide group is bonded (i.e., the para position in the above case). In particular, it is preferable that both the ^Ar1 and ^Ar2 aromatic rings have substituents at least at the position (ortho position) of one or both carbons adjacent to the carbon to which the maleimide group is bonded.

When the aromatic rings of ^Ar1 and ^Ar2 are benzene, it is preferable that the bonds to other sites* extend from the para position relative to the maleimide group in the aromatic ring.

Furthermore, ^Ar1 and ^Ar2 in formulas (1) and (2) must be different from each other in at least one of the following ways: the type of substituent, the number of substituents, and the position of the substituents. Examples of "different from each other" are not limited to the following:
[1] Different types of substituents (Specific example: one Ar has a methyl group, the other Ar has an ethyl group)
[2] The number of substituents is different (specific example: one Ar has one substituent, and the other Ar has two)
[3] Different positions of substituents (Specific example: When the aromatic rings of ^Ar1 and ^Ar2 are benzene, one Ar is at the ortho position and the other is at the meta position)
[4] Any combination of [1] to [3] above (Specific example: When the aromatic rings of ^Ar1 and ^Ar2 are benzene, one Ar has one ethyl group on one ortho position relative to the maleimide group, and the other Ar has one methyl group on each ortho position relative to the maleimide group, for a total of two groups)

The number of aromatic ring-maleimide skeletons in one molecule of maleimide compound (a) must be two or more, but it may be two (i.e., a dinuclear component (bismaleimide compound)), three (i.e., a trinuclear component (trismaleimide compound)), four (i.e., a tetranuclear component), or five or more.
Herein, in this specification, "nuclear body number" refers to the number of aromatic ring-maleimide skeletons in one molecule. The above aromatic ring-maleimide skeleton is typically a skeleton derived from the aromatic monoamine compound that is the reaction raw material.

Specifically, the maleimide compound (a) is preferably a component with a relatively low molecular weight, such as a dinuclear component represented by formula (3-1), a trinuclear component represented by formula (3-2), a tetranuclear component represented by formula (3-3), or a tetranuclear component represented by formula (3-4).

[In the formula, A is the aromatic ring-maleimide skeleton, and B is an arbitrarily selected site. A and B in the formula may be the same or different.]

If a molecule contains three or more aromatic ring-maleimide skeletons, it is classified as maleimide compound (a) if the substituents on at least two of these aromatic rings are distinct from each other.

In particular, the maleimide resin (A) preferably contains a dinuclear component (bismaleimide compound). Furthermore, the proportion of the dinuclear component (bismaleimide compound) in the maleimide resin (A) is preferably 30% or more, and more preferably 50% or more.
The content of dinuclear components in maleimide resin (A) is calculated from the area ratio of the gel permeation chromatography (GPC) chart. The measurement conditions for gel permeation chromatography (GPC) are as shown in the examples described below.

The maleimide compound (a) is preferably an asymmetric bismaleimide compound in which the first aromatic ring-maleimide skeleton and the second aromatic ring-maleimide skeleton are bonded via an organic group having 1 to 200 carbon atoms. More specifically, the following general formula (3-5):
It is preferable that the compound is an asymmetric bismaleimide compound (a dinuclear component) represented by [In formulas (3-5), ^R1 to ^R4 , ^Ar1 and ^Ar2 are the same as defined in formulas (1) and (2), and Z is an organic group having 1 to 200 carbon atoms.]. In this embodiment, the asymmetric bismaleimide compound may be isolated and purified before use.

When the aromatic rings ^Ar1 and ^Ar2 in formula (3-5) are benzene, the position of the bond from the aromatic ring to Z is preferably the para position relative to the maleimide group.

In the above formula (3-5), Z is typically a site derived from the binder, which is the reaction raw material. Z is a divalent organic group having 1 to 200 carbon atoms, but it may also contain other atoms such as oxygen atoms or halogen atoms, as long as the number of carbon atoms is within the range of 1 to 200. Among these, Z is more preferably a divalent organic group having 1 to 20 carbon atoms. Specific examples of Z include, for example, the sites represented by the following general formulas (Z-1) to (Z-8).

In general formula (Z-1), ^R5 independently represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 4 carbon atoms, or an aromatic ring which may have substituents.
The above-mentioned aliphatic hydrocarbon group having 1 to 4 carbon atoms may be linear, branched, or cyclic, and may contain unsaturated bonds in its structure. Specific examples of the above-mentioned aliphatic hydrocarbon group having 1 to 4 carbon atoms include methyl, ethyl, vinyl, propyl, allyl, and butyl groups.
Examples of aromatic rings that may have the above substituents include phenyl groups, naphthyl groups, and structural sites having one or more substituents on these aromatic rings. Examples of the above substituents include aliphatic hydrocarbon groups, alkyloxy groups, alkenyloxy groups, halogen atoms, aryl groups, aralkyl groups, hydroxyl groups, and the like.
The above aliphatic hydrocarbon group may be linear, branched, or cyclic, and may have unsaturated bonds in its structure. Specific examples of the above aliphatic hydrocarbon group include methyl, ethyl, vinyl, propyl, allyl, butyl, pentyl, hexyl, cyclohexyl, heptyl, octyl, and nonyl groups.
Examples of the alkyloxy groups mentioned above include methoxy groups, ethoxy groups, propyloxy groups, and butoxy groups.
Examples of the above-mentioned alkenyloxy group include allyloxy groups.
Examples of the halogen atoms mentioned above include fluorine atoms, chlorine atoms, and bromine atoms.
Examples of the aryl groups mentioned above include phenyl groups, naphthyl groups, anthryl groups, and groups in which the above aliphatic hydrocarbon groups, alkyloxy groups, or halogen atoms are substituted on the aromatic core of these groups.
Examples of the above-mentioned aralkyl groups include benzyl groups, phenylethyl groups, naphthylmethyl groups, naphthylethyl groups, and groups in which an alkyl group, or the alkyloxy group or halogen atom mentioned above, is substituted on the aromatic core of these groups.

In general formulas (Z-2), (Z-3), and (Z-8), ^Ar3 independently represents an aromatic ring which may have substituents. Specifically, ^Ar3 can be a phenylene group, a naphthylene group, or a group having one or more substituents on these aromatic rings. Examples of substituents include aliphatic hydrocarbon groups, alkyloxy groups, alkenyloxy groups, halogen atoms, aryl groups, aralkyl groups, and hydroxyl groups.
The above aliphatic hydrocarbon group may be linear, branched, or cyclic, and may have unsaturated bonds in its structure. Specific examples of the above aliphatic hydrocarbon group include methyl, ethyl, vinyl, propyl, allyl, butyl, pentyl, hexyl, cyclohexyl, heptyl, octyl, and nonyl groups.
Examples of the alkyloxy groups mentioned above include methoxy groups, ethoxy groups, propyloxy groups, and butoxy groups.
Examples of the above-mentioned alkenyloxy group include the allyloxy group.
Examples of the halogen atoms mentioned above include fluorine atoms, chlorine atoms, and bromine atoms.
Examples of the aryl groups mentioned above include phenyl groups, naphthyl groups, anthryl groups, and groups in which the above aliphatic hydrocarbon groups, alkyloxy groups, or halogen atoms are substituted on the aromatic core of these groups.
Examples of the above-mentioned aralkyl groups include benzyl groups, phenylethyl groups, naphthylmethyl groups, naphthylethyl groups, and groups in which an alkyl group, or the alkyloxy group or halogen atom mentioned above, is substituted on the aromatic core of these groups.

In the above general formulas (Z-2) and (Z-3), R ⁶ independently represents either a hydrogen atom or an aliphatic hydrocarbon group having 1 to 4 carbon atoms. The above aliphatic hydrocarbon group having 1 to 4 carbon atoms may be linear, branched, or cyclic, and may have unsaturated bonds in its structure. Specific examples of the above aliphatic hydrocarbon group having 1 to 4 carbon atoms include methyl, ethyl, vinyl, propyl, allyl, and butyl groups.

In the general formula (Z-3) above, Y represents a single bond, a divalent aliphatic hydrocarbon group having 1 to 6 carbon atoms, an oxygen atom, a sulfur atom, or a sulfonyl group. The divalent aliphatic hydrocarbon group having 1 to 6 carbon atoms may be linear, branched, or cyclic, and may contain unsaturated bonds within its structure.

In the above general formula (Z-4), ^R8 is independently an aliphatic hydrocarbon group, an alkyloxy group, an alkenyloxy group, an alkynyloxy group, a halogen atom, an aryl group, or an aralkyl group, l is an integer from 0 to 3, and n is an integer of 1 or more.
The above aliphatic hydrocarbon group may be linear, branched, or cyclic, and may contain unsaturated bonds in its structure. Specific examples of the above aliphatic hydrocarbon group include methyl, ethyl, vinyl, propyl, allyl, butyl, pentyl, hexyl, cyclohexyl, heptyl, octyl, and nonyl groups.
Examples of the alkyloxy groups mentioned above include methoxy groups, ethoxy groups, propyloxy groups, and butoxy groups.
Examples of the above-mentioned alkenyloxy group include the allyloxy group.
Examples of the halogen atoms mentioned above include fluorine atoms, chlorine atoms, and bromine atoms.
Examples of the aryl groups mentioned above include phenyl groups, naphthyl groups, anthryl groups, and groups in which the above aliphatic hydrocarbon groups, alkyloxy groups, or halogen atoms are substituted on the aromatic core of these groups.
Examples of the above-mentioned aralkyl groups include benzyl groups, phenylethyl groups, naphthylmethyl groups, naphthylethyl groups, and groups in which an alkyl group, or the alkyloxy group or halogen atom mentioned above, is substituted on the aromatic core of these groups.

In the above general formula (Z-7), ^R7 represents a divalent aliphatic hydrocarbon group other than those represented by general formula (Z-1), an aromatic group which may have substituents, or a combination thereof. The above divalent aliphatic hydrocarbon group may be linear, branched, or cyclic, and may have unsaturated bonds in its structure.

<Manufacturing of Maleimide Resin (A)>
Maleimide resin (A) (i.e., a resin containing maleimide compound (a)) is obtained by reacting multiple types of aromatic monoamine compounds (i.e., compounds with different substituent configurations) with a binder to produce a polyamine compound, and then maleimidizing the polyamine compound. The structures of the multiple types of aromatic monoamine compounds contribute to the first aromatic ring-maleimide skeleton and the second aromatic ring-maleimide skeleton in the obtained maleimide compound (a).

As for the aromatic monoamine compound mentioned above, any compound having one _NH₂ group on the aromatic ring is acceptable, but there are no particular limitations on its other specific structures, and a wide variety of compounds can be used. Specifically, examples of the aromatic monoamine compound include compounds having one _NH₂ group on the aromatic ring, and compounds having one or more substituents in addition to the _NH₂ group on the aromatic ring.

Examples of the aromatic rings mentioned above include benzene, naphthalene, and anthracene.

Examples of the substituents mentioned above include aliphatic hydrocarbon groups, alkyloxy groups, alkenyloxy groups, alkynyloxy groups, halogen atoms, aryl groups, aralkyl groups, and hydroxyl groups. These substituents substantially correspond to the substituents on the ^Ar1 and ^Ar2 aromatic rings in the resulting maleimide compound (a). Therefore, specific examples of these substituents are as previously described.

Among aromatic monoamine compounds, it is preferable to use aniline, compounds having substituents at the 2-position of aniline, and/or compounds having substituents at the 2,6-positions of aniline. Furthermore, in the case of compounds having substituents at the 2-position and compounds having substituents at the 2,6-positions of aniline, the substituents are preferably aliphatic hydrocarbon groups having 1 to 4 carbon atoms, and more preferably alkyl groups having 1 to 4 carbon atoms (methyl group, ethyl group, propyl group, butyl group, etc.), as this results in a maleimide resin with excellent heat resistance in the cured product.

In this embodiment, as described above, multiple types of the above-mentioned aromatic monoamine compounds are used. This results in a maleimide resin that maintains the high heat resistance characteristic of maleimide resins while exhibiting low melting and softening points and excellent handling properties, thereby achieving the desired effects. The number of aromatic monoamine compounds used may be two or more, and while there is no particular upper limit, it is preferable to use two to five types, and more preferably two or three types, as this allows for relatively simple manufacturing.

Furthermore, the amount of each aromatic monoamine compound used is preferably at least 10% by mass, and more preferably 25% by mass, relative to the total amount of aromatic monoamine compounds, in order to fully exhibit the effects of improving photosensitivity, developability, heat resistance, and coating film appearance. Also, the amount of each aromatic monoamine compound used is preferably 90% by mass or less, and more preferably 75% by mass or less, relative to the total amount of aromatic monoamine compounds. In particular, when using two types of aromatic monoamine compounds, the mass ratio of the two is preferably in the range of 10/90 to 90/10, and more preferably in the range of 20/80 to 80/20.

As a binder, any compound that reacts with an aromatic monoamine compound and bonds the aromatic rings of the aromatic monoamine compound is acceptable, and its specific structure is not particularly limited; a variety of compounds can be used. The binder may be used alone or in combination of two or more types. Specific examples of the above-mentioned binders include, for example, aldehyde compounds (B-1) and ketone compounds (B-2).
Examples of aldehyde compounds (B-1) include aliphatic aldehyde compounds such as formaldehyde and acetaldehyde, and aromatic aldehyde compounds such as benzaldehyde and naphthaldehyde. Aldehyde compounds (B-1) may be used individually or in combination of two or more.
Examples of ketone compounds (B-2) include aliphatic ketone compounds such as acetone, methyl ethyl ketone, and diethyl ketone, and aromatic ketone compounds such as acetophenone. Ketone compounds (B-2) may be used individually or in combination of two or more.

Furthermore, specific examples of the above-mentioned binders include aromatic compounds represented by the following general formula (B-3) (B-3), aromatic compounds represented by the following general formula (B-4) (B-4), aromatic compounds represented by the following general formula (B-5) (B-5), aromatic compounds represented by the following general formula (B-6) (B-6), aromatic compounds represented by the following general formula (B-7) (B-7), aromatic compounds represented by the following general formula (B-8) (B-8), and the like.

In the above general formulas (B-3) to (B-6), ^Ar3 independently represents an aromatic ring that may have substituents. Specific examples of ^Ar3 include those similar to the ^Ar3 in the above general formulas (Z-2), (Z-3), and (Z-8).

In the above general formulas (B-3) and (B-5), R ⁹ is independently either a hydrogen atom or a methyl group.

In the above general formulas (B-4) and (B-6), R ¹⁰ independently represents either a hydrogen atom or an aliphatic hydrocarbon group having 1 to 4 carbon atoms. The above aliphatic hydrocarbon group having 1 to 4 carbon atoms may be linear, branched, or cyclic, and may have unsaturated bonds in its structure. Specific examples of the above aliphatic hydrocarbon group having 1 to 4 carbon atoms include methyl, ethyl, vinyl, propyl, allyl, and butyl groups.

In the above general formulas (B-7) and (B-8), R ⁸ independently represents an aliphatic hydrocarbon group, an alkyloxy group, an alkenyloxy group, an alkynyloxy group, a halogen atom, an aryl group, or an aralkyl group, and l is an integer from 0 to 3. Specific examples of R ⁸ include those similar to R ⁸ in the above general formula (Z-4).

In the above general formulas (B-4), (B-6), and (B-8), X represents a hydroxyl group, a halogen atom, or an alkyloxy group. Examples of alkyloxy groups include methoxy, ethoxy, propyloxy, and butoxy groups.

In the general formulas (B-5) and (B-6) above, Y represents a single bond, a divalent aliphatic hydrocarbon group having 1 to 6 carbon atoms, an oxygen atom, a sulfur atom, or a sulfonyl group. The divalent aliphatic hydrocarbon group having 1 to 6 carbon atoms may be linear, branched, or cyclic, and may contain unsaturated bonds.

One method for producing a polyamine compound by reacting multiple aromatic monoamine compounds with a binder is to react the multiple aromatic monoamine compounds with the binder under acidic catalytic conditions. In particular, it is preferable to add the binder in divided portions to the aromatic monoamine compounds, as this facilitates reaction control. This reaction may be carried out in a solvent as appropriate. Furthermore, the reaction can be efficiently advanced by heating to approximately 50-200°C. After the reaction is complete, the intermediate polyamine compound can be obtained by washing with an alkaline aqueous solution or distilled water.

Examples of the above-mentioned acidic catalysts include p-toluenesulfonic acid, dimethyl sulfuric acid, diethyl sulfuric acid, sulfuric acid, hydrochloric acid, oxalic acid, and activated clay. The acidic catalyst may be used alone or in combination of two or more types. The amount of acidic catalyst added is preferably in the range of 0.01 to 0.5 moles, and more preferably in the range of 0.1 to 0.3 moles, per 2 moles of the aromatic monoamine compound. If the number of moles cannot be defined, the amount is preferably in the range of 1% to 50% by mass relative to the total amount of the aromatic monoamine compound, binder, solvent, and acidic catalyst.

Examples of the solvents mentioned above include distilled water and organic solvents such as toluene and xylene. The solvent may be used alone or in combination of two or more. The amount of solvent used is preferably in the range of 5% to 100% by mass relative to the total amount of the aromatic monoamine compound and the binder.

Next, as a step to maleimide the intermediate polyamine compound (maleimide reaction), for example, a method of reacting the polyamine compound with an acid anhydride under acidic catalytic conditions can be used. In particular, since reaction control is easier, it is preferable to either add the acid anhydride to the polyamine compound in divided portions, or to dissolve the acid anhydride in a suitable solvent and add it dropwise. This reaction may also be carried out in a solvent as appropriate. The reaction procedure is to first stir the polyamine compound and acid anhydride at room temperature to obtain an amic acid intermediate, then add the acid catalyst, and preferably heat to 50 to 200°C, more preferably 70 to 150°C to allow the reaction to proceed. At this time, it is preferable to remove water from the system. After the reaction is complete, the desired maleimide resin (A) can be obtained by washing with an alkaline aqueous solution or distilled water, etc.

Examples of the above-mentioned acid anhydrides include maleic anhydride, citraconic anhydride, and 2,3-dimethylmaleic anhydride. The acid anhydrides may be used individually or in combination of two or more.

Examples of the above-mentioned acidic catalysts include p-toluenesulfonic acid, hydroxy-p-toluenesulfonic acid, methanesulfonic acid, sulfuric acid, and phosphoric acid. The acidic catalyst may be used alone or in combination of two or more. The amount of acidic catalyst added is typically 0.01 to 10 mol, preferably 0.03 to 3 mol, per 1 g/mol of the amino group equivalent of the polyamine compound.

The solvent described above is not particularly limited, as long as it can dissolve the polyamine compound and the acid anhydride. In particular, a mixed solvent of a nonpolar solvent such as toluene and an aprotic polar solvent such as dimethylformamide is preferred, as this allows for high solubility of the polyamine compound and acid anhydride and efficient reaction. Examples of nonpolar solvents include toluene, xylene, and chlorobenzene. Examples of aprotic polar solvents include dimethylformaldehyde and methyl ethyl ketone. The mixing ratio of the two solvents and the amount of solvent used can be appropriately adjusted depending on the solubility of the polyamine compound and acid anhydride. For example, the mass ratio of the nonpolar solvent to the aprotic solvent can be in the range of 1/99 to 99/1, and the total amount of solvent can be in the range of 0.5 to 80% by mass relative to the total amount of the polyamine compound, acid anhydride, and total solvent.

(Resin (B) having acidic groups and polymerizable unsaturated groups)
Resin (B), which has acidic groups and polymerizable unsaturated groups, is one of the essential components in the resin composition of this embodiment. Resin (B) only needs to have acidic groups and polymerizable unsaturated groups; other specific structures or molecular weights are not particularly limited, and a wide variety of resins can be used.

In this embodiment, examples of acidic groups in resin (B) include carboxyl groups, sulfonic acid groups, and phosphoric acid groups. Among these, carboxyl groups are preferred as acidic groups because they exhibit excellent alkali developability. Examples of polymerizable unsaturated groups in resin (B) include (meth)acryloyl groups, allyl groups, isopropenyl groups, 1-propenyl groups, styryl groups, styrylmethyl groups, maleimide groups, and vinyl ether groups.

Examples of the resin (B) having acidic groups and polymerizable unsaturated groups in this embodiment include the following [1] to [6]:
[1] Epoxy resin having acidic groups and polymerizable unsaturated groups (B1),
[2] Urethane resin having acidic groups and polymerizable unsaturated groups (B2)
[3] Acrylic resin having acidic groups and polymerizable unsaturated groups (B3),
[4] Amidoimide resin having acid groups and polymerizable unsaturated groups (B4)
[5] Acrylamide resin having acidic groups and polymerizable unsaturated groups (B5),
[6] Ester resin having acidic groups and polymerizable unsaturated groups (B6),
Examples include resins such as the above. The epoxy resin (B1) to ester resin (B6) will be described below in order.

<Epoxy resin (B1) having acidic groups and polymerizable unsaturated groups>
Examples of epoxy resins (B1) having acidic groups and polymerizable unsaturated groups include epoxy (meth)acrylate resins having acidic groups, which require epoxy resin (b1-1), unsaturated monobasic acid (b1-2), and polybasic acid anhydride (b1-3) as essential reaction raw materials, and epoxy (meth)acrylate resins having acidic groups and urethane bonds, which require epoxy resin (b1-1), unsaturated monobasic acid (b1-2), polybasic acid anhydride (b1-3), polyisocyanate compound (b1-4), and (meth)acrylate compound having hydroxyl groups (b1-5) as reaction raw materials.

The specific structure of the epoxy resin (b1-1) is not particularly limited, as long as it has multiple epoxy groups in the resin. Examples of the epoxy resin (b1-1) include bisphenol type epoxy resin, hydrogenated bisphenol type epoxy resin, biphenol type epoxy resin, hydrogenated biphenol type epoxy resin, phenylene ether type epoxy resin, naphthylene ether type epoxy resin, biphenyl type epoxy resin, triphenylmethane type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol novolac type epoxy resin, naphthol novolac type epoxy resin, naphthol-phenol copolymer novolac type epoxy resin, naphthol-cresol copolymer novolac type epoxy resin, phenol aralkyl type epoxy resin, naphthol aralkyl type epoxy resin, dicyclopentadiene-phenol addition reaction type epoxy resin, biphenyl aralkyl type epoxy resin, fluorene type epoxy resin, xanthene type epoxy resin, dihydroxybenzene type epoxy resin, trihydroxybenzene type epoxy resin, oxazolidone type epoxy resin, and the like. These epoxy resins may be used individually or in combination of two or more types.

Examples of the bisphenol-type epoxy resins mentioned above include bisphenol A type epoxy resin, bisphenol AP type epoxy resin, bisphenol B type epoxy resin, bisphenol BP type epoxy resin, bisphenol E type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin.
Examples of the above-mentioned hydrogenated bisphenol type epoxy resins include hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol B type epoxy resin, hydrogenated bisphenol E type epoxy resin, hydrogenated bisphenol F type epoxy resin, and hydrogenated bisphenol S type epoxy resin.
Examples of the above-mentioned 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 the above-mentioned hydrogenated biphenol-type epoxy resins include hydrogenated 4,4'-biphenol-type epoxy resin, hydrogenated 2,2'-biphenol-type epoxy resin, hydrogenated tetramethyl-4,4'-biphenol-type epoxy resin, and hydrogenated tetramethyl-2,2'-biphenol-type epoxy resin.
The epoxy resin (b1-1) may be used alone or in combination of two or more types.

Examples of unsaturated monobasic acids (b1-2) include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, α-cyanocinnamic acid, β-styrylacrylic acid, β-furfurylacrylic acid, etc. Acid halides and esters of the above unsaturated monobasic acids can also be used. Furthermore, as an unsaturated monobasic acid (b1-2), the following general formula (4):
Compounds represented by the above general formula (4) [In the above general formula (4), X ⁴¹ represents an alkylene chain, polyoxyalkylene chain, (poly)ester chain, aromatic hydrocarbon chain, or (poly)carbonate chain having 1 to 10 carbon atoms, and the hydrogen atoms in the structure of X ⁴¹ may be substituted with halogen atoms or alkoxy groups, and Y ⁴¹ is a hydrogen atom or a methyl group.] may also be used.

Examples of the polyoxyalkylene chains mentioned above include polyoxyethylene chains and polyoxypropylene chains.
Examples of the above (poly)ester chain include the following general formula (5):
Examples of (poly)ester chains represented by the above general formula (5) include those in which R ⁵¹ and R ⁵² represent alkylene groups having 1 to 10 carbon atoms, and n ⁵¹ represents an integer from 1 to 5.

Examples of the above-mentioned aromatic hydrocarbon chains include phenylene chains, naphthylene chains, biphenylene chains, phenylnaphthylene chains, or binaphthylene chains. In addition, hydrocarbon chains having aromatic rings such as benzene rings, naphthalene rings, anthracene rings, and phenanthrene rings as partial structures can also be used.
Examples of the above (poly)carbonate chains include the following general formula (6):
Examples of (poly)carbonate chains are those represented by the following general formula (6) above: [In the above general formula (6), R ⁶¹ represents an alkylene group having 1 to 10 carbon atoms, and n ⁶¹ represents an integer from 1 to 5.]

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

Unsaturated monobasic acids (b1-2) may be used individually or in combination of two or more.

Examples of polybasic acid anhydrides (b1-3) include aliphatic polybasic acid anhydrides, alicyclic polybasic acid anhydrides, aromatic polybasic acid anhydrides, acid halides of aliphatic polybasic acid anhydrides, acid halides of alicyclic polybasic acid anhydrides, and acid halides of aromatic polybasic acid anhydrides.

Examples of the above-mentioned aliphatic polybasic acid anhydrides include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, and acid anhydrides of 1,2,3,4-butanetetracarboxylic acid. Furthermore, the aliphatic hydrocarbon groups in the aliphatic polybasic acid anhydrides may be linear or branched, and may contain unsaturated bonds in their structure.

In this invention, the above-mentioned alicyclic polybasic acid anhydride is defined as one in which the acid anhydride group is bonded to an alicyclic structure, and the presence or absence of aromatic rings in other structural parts is irrelevant. Examples of the alicyclic polybasic acid anhydride include tetrahydrophthalic acid, hexahydrophthalic acid, methylhexahydrophthalic acid, cyclohexanetricarboxylic acid, cyclohexanetetracarboxylic acid, bicyclo[2.2.1]heptane-2,3-dicarboxylic acid, methylbicyclo[2.2.1]heptane-2,3-dicarboxylic acid, and the acid anhydride of 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid.

Examples of the above-mentioned aromatic polybasic acid anhydrides include phthalic acid, trimellitic acid, pyromellitic acid, naphthalenedicarboxylic acid, naphthalentricarboxylic acid, naphthalenetetracarboxylic acid, biphenyldicarboxylic acid, biphenyltricarboxylic acid, biphenyltetracarboxylic acid, and benzophenonetetracarboxylic acid acid anhydrides.

The polybasic acid anhydrides (b1-3) may be used individually or in combination of two or more. Among these, tetrahydrophthalic anhydride, succinic anhydride, and cyclohexanedicarboxylic acid anhydride are preferred from the viewpoint of more effectively improving photosensitivity, developability, heat resistance, and/or coating film appearance.

Examples of polyisocyanate compounds (b1-4) include aliphatic diisocyanate compounds such as butane diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate; alicyclic diisocyanate compounds such as norbornane diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated diphenylmethane diisocyanate; and tolylene diisocyanate. Aromatic diisocyanate compounds such as xylylene diisocyanate, tetramethyl xylylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-diisocyanato-3,3'-dimethylbiphenyl, and o-tolidine diisocyanate; polymethylene polyphenyl polyisocyanates having a repeating structure represented by the following general formula (7); and isocyanurate modified versions, biuret modified versions, allophanate modified versions, etc. of these.
The polyisocyanate compounds (b1-4) may be used individually or in combination of two or more.
[In the above general formula (7), R ⁷² and R ⁷³ each independently represent either a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, R ⁷¹ each independently represents an alkyl group having 1 to 4 carbon atoms, k ⁷¹ is 0 or an integer from 1 to 3, and n ⁷¹ is an integer of 1 or more.]

Examples of (meth)acrylate compounds having a hydroxyl group (b1-5) include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, trimethylolpropane (meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol (meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, ditrimethylolpropane (meth)acrylate, ditrimethylolpropane di(meth)acrylate, and ditrimethylolpropane tri(meth)acrylate. Furthermore, (poly)oxyalkylene modified compounds, in which (poly)oxyalkylene chains such as (poly)oxyethylene chains, (poly)oxypropylene chains, and (poly)oxytetramethylene chains are introduced into the molecular structure of the various hydroxyl group-containing (meth)acrylate compounds, and lactone modified compounds, in which a (poly)lactone structure is introduced into the molecular structure of the various hydroxyl group-containing (meth)acrylate compounds, can also be used.

Among these, those with a molecular weight of 1,000 or less are preferred from the viewpoint of more effectively improving light sensitivity, developability, heat resistance and/or coating film appearance. Furthermore, if the (meth)acrylate compound (b1-5) having a hydroxyl group is an oxyalkylene modified or lactone modified, it is preferable that its weight-average molecular weight (Mw) is 1,000 or less.
The (meth)acrylate compounds (b1-5) having a hydroxyl group may be used individually or in combination of two or more.

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

The method for producing the epoxy resin (B1) having acidic groups and polymerizable unsaturated groups is not particularly limited, as long as epoxy resin (b1-1), unsaturated monobasic acid (b1-2), and polybasic acid anhydride (b1-3) are essential reaction raw materials, or as long as epoxy resin (b1-1), unsaturated monobasic acid (b1-2), polybasic acid anhydride (b1-3), polyisocyanate compound (b1-4), and (meth)acrylate compound (b1-5) having hydroxyl groups are used as reaction raw materials. For example, the epoxy resin (B1) may be produced by reacting all the reaction raw materials together, or by reacting the reaction raw materials sequentially. Among these, the method of reacting the epoxy resin (b1-1) with the unsaturated monobasic acid (b1-2) first, and then with the polybasic acid anhydride (b1-3), is preferred because the reaction can be easily controlled. This reaction can be carried out, for example, by reacting an epoxy resin (b1-1) with an unsaturated monobasic acid (b1-2) in the presence of a basic catalyst at a temperature range of 100 to 150°C, then adding a polybasic acid anhydride (b1-3) to the reaction system and reacting at a temperature range of 80 to 140°C.

In this embodiment, the reaction ratio of the epoxy resin (b1-1) to the unsaturated monobasic acid (b1-2) is preferably in the range of 0.9 to 1.1 moles of unsaturated monobasic acid (b1-2) per mole of epoxy groups in the epoxy resin (b1-1). Furthermore, the reaction ratio of the polybasic acid anhydride (b1-3) is preferably in the range of 0.2 to 1.0 mole per mole of epoxy groups in the epoxy resin (b1-1).

Examples of the above organic solvents include hydrocarbon solvents such as toluene, xylene, heptane, hexane, and mineral spirits; ketone solvents such as methyl ethyl ketone, acetone, dimethylformamide, methyl isobutyl ketone, cyclohexanone, and dimethylacetamide; 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; and carbitol, cellosolve, methanol, ethanol, propanol, isopropanol, butanol, and cyclohexanone. Examples of organic solvents include alcohol solvents such as propylene glycol monomethyl ether; ether solvents such as propyl ether, methyl cellosolve, cellosolve, butyl cellosolve, and methyl carbitol; glycol ether solvents such as alkylene glycol monoalkyl ether, dialkylene glycol monoalkyl ether, and dialkylene glycol monoalkyl ether acetate; vegetable oils such as soybean oil, linseed oil, rapeseed oil, and safflower oil; and methoxypropanol, cyclohexanone, methyl cellosolve, diethylene glycol monoethyl ether acetate, and propylene glycol monomethyl ether acetate. These organic solvents may be used individually or in combination of two or more.

Furthermore, commercially available organic solvents can also be used, such as ENEOS Corporation's "Spindle Oil No. 1", "Solvent No. 3", "Solvent No. 4", "Solvent No. 5", "Solvent No. 6", "Naphthezol H", "Alken 56NT", "AF Solvent No. 4", "AF Solvent No. 5", "AF Solvent No. 6", "AF Solvent No. 7", Mitsubishi Chemical Corporation's "Diadol 13", "Dialen 168"; Nissan Chemical Corporation's "F Oxocol", "F Oxocol 180"; Idemitsu Kosan Co., Ltd.'s "Supersol LA35", "Supersol LA38"; ExxonMobil Examples include Chemical's "Exol D80,""ExolD110,""ExolD120,""ExolD130,""ExolD160,""ExolD100K,""ExolD120K,""ExolD130K,""ExolD280,""ExolD300," and "Exol D320."
In this embodiment, the amount of organic solvent used is preferably in the range of 0.1 to 5 times the total mass of the reaction raw materials, as this results in good reaction efficiency.

Examples of basic catalysts include amine compounds such as 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, tetramethylammonium hydroxide, etc.; trioctylmethylammonium chloride, trio Examples include quaternary ammonium salts such as ctylmethylammonium acetate; phosphines such as trimethylphosphine, tributylphosphine, and triphenylphosphine; phosphonium salts such as tetramethylphosphonium chloride, tetraethylphosphonium chloride, tetrapropylphosphonium chloride, tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, trimethyl(2-hydroxylpropyl)phosphonium chloride, triphenylphosphonium chloride, and benzylphosphonium chloride; organotin 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-dodecanoyldistanoxane; organometallic compounds such as zinc octoate and bismuth octoate; inorganic tin compounds such as tin octanoate; and inorganic metal compounds. Alkaline earth metal hydroxides, alkali metal carbonates, and alkali metal hydroxides can also be used.
The basic catalyst may be used alone or in combination of two or more types. Furthermore, the amount of basic catalyst added is preferably in the range of 0.001 to 5 parts by mass per 100 parts by mass of the total reaction raw materials.

The acid value of the epoxy resin (B1) having acidic groups and polymerizable unsaturated groups is preferably in the range of 30 to 150 mg KOH/g, and more preferably in the range of 40 to 120 mg KOH/g, from the viewpoint of more effectively improving photosensitivity, developability, heat resistance, and/or coating film appearance. In this disclosure, the acid value of the resin (B) having acidic groups and polymerizable unsaturated groups is the value measured by the neutralization titration method of JIS 0070 (1992).

<Urethane resin (B2) having acidic groups and polymerizable unsaturated groups>
As a urethane resin (B2) having acid groups and polymerizable unsaturated groups, for example, a resin obtained by reacting a polyisocyanate compound (b1-4), a hydroxyl group-containing (meth)acrylate compound (b1-5), a carboxyl group-containing polyol compound (b2-1), and, if necessary, a polybasic acid anhydride (b1-3), a polyol compound other than the carboxyl group-containing polyol compound (b2-2); polyisocyanate compound (b1-4) and hydroxyl group-containing ( Examples include resins obtained by reacting a meth)acrylate compound (b1-5) with a polybasic acid anhydride (b1-3) and a polyol compound other than a carboxyl group-containing polyol compound (b2-1) (b2-2); or resins obtained by reacting an epoxy resin (b1-1) with an unsaturated monobasic acid (b1-2), a polybasic acid anhydride (b1-3), a polyisocyanate compound (b1-4), and a hydroxyl group-containing (meth)acrylate compound (b1-5).

Examples of carboxyl group-containing polyol compounds (b2-1) include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, and 2,2-dimethylolvaleric acid. These carboxyl group-containing polyol compounds can be used individually or in combination of two or more.

Examples of polyol compounds other than the carboxyl group-containing polyol compound (b2-1) (b2-2) include aliphatic polyol compounds such as ethylene glycol, propylene glycol, butanediol, hexanediol, glycerin, trimethylolpropane, ditrimethylolpropane, pentaerythritol, and dipentaerythritol; aromatic polyol compounds such as biphenol and bisphenol; (poly)oxyalkylene modified compounds in which (poly)oxyalkylene chains such as (poly)oxyethylene chains, (poly)oxypropylene chains, and (poly)oxytetramethylene chains are introduced into the molecular structure of the various polyol compounds; and lactone modified compounds in which a (poly)lactone structure is introduced into the molecular structure of the various polyol compounds. The polyol compounds other than the carboxyl group-containing polyol compounds can be used individually or in combination of two or more.

The method for producing the urethane resin (B2) having acidic groups and polymerizable unsaturated groups is not particularly limited, and any method may be used. In the production of the urethane resin having acidic groups and polymerizable unsaturated groups, the process may be carried out in an organic solvent as needed, and a basic catalyst may also be used as needed.

The organic solvent described above can be the same as the organic solvent described in the section above for "Epoxy resin having acidic groups and polymerizable unsaturated groups (B1)," and the organic solvent can be used alone or in combination of two or more types. Furthermore, the basic catalyst described above can be the same as the basic catalyst described in the section above for "Epoxy resin having acidic groups and polymerizable unsaturated groups (B1)," and the basic catalyst can be used alone or in combination of two or more types.

<Acrylic resin (B3) having acidic groups and polymerizable unsaturated groups>
Examples of the acrylic resin (B3) having acidic groups and polymerizable unsaturated groups in this embodiment include a reaction product obtained by introducing (meth)acryloyl groups by further reacting an acrylic resin intermediate obtained by polymerizing an acrylic resin intermediate having a reactive functional group such as a hydroxyl group or a carboxyl group, isocyanate group, or glycidyl group with an acrylic resin intermediate having a reactive functional group that can react with these functional groups, or a resin obtained by reacting a polybasic acid anhydride (b1-3) with the hydroxyl groups in the reaction product.

In this embodiment, the acrylic resin intermediate may be copolymerized with other polymerizable unsaturated group-containing compounds as needed, in addition to the (meth)acrylate compound (α). Examples of such other polymerizable unsaturated group-containing compounds include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate; alicyclic structure-containing (meth)acrylates such as cyclohexyl (meth)acrylate, isobolonyl (meth)acrylate, and dicyclopentanyl (meth)acrylate; aromatic ring-containing (meth)acrylates such as phenyl (meth)acrylate, benzyl (meth)acrylate, and phenoxyethyl acrylate; silyl group-containing (meth)acrylates such as 3-methacryloxypropyltrimethoxysilane; and styrene derivatives such as styrene, α-methylstyrene, and chlorostyrene.
Other polymerizable unsaturated group-containing compounds can be used individually or in combination of two or more.

The above (meth)acrylate compound (β) is not particularly limited as long as it can react with the reactive functional group of the above (meth)acrylate compound (α), but from the viewpoint of reactivity, the following combinations are preferred. That is, when a hydroxyl group-containing (meth)acrylate is used as the (meth)acrylate compound (α), it is preferable to use an isocyanate group-containing (meth)acrylate as the (meth)acrylate compound (β). When a carboxyl group-containing (meth)acrylate is used as the (meth)acrylate compound (α), it is preferable to use a glycidyl group-containing (meth)acrylate as the (meth)acrylate compound (β). When an isocyanate group-containing (meth)acrylate is used as the (meth)acrylate compound (α), it is preferable to use a hydroxyl group-containing (meth)acrylate as the (meth)acrylate compound (β). When a glycidyl group-containing (meth)acrylate is used as the (meth)acrylate compound (α), it is preferable to use a carboxyl group-containing (meth)acrylate as the (meth)acrylate compound (β).
(Meth)acrylate compounds (β) can be used alone or in combination of two or more.

The method for producing the acrylic resin (B3) having acidic groups and polymerizable unsaturated groups in this embodiment is not particularly limited and may be produced by any method. The production of the acrylic resin (B3) having acidic groups and polymerizable unsaturated groups may be carried out in an organic solvent as needed, and a basic catalyst may also be used as needed.
The organic solvent can be the same as the organic solvent described in the section above for "Epoxy resin having acidic groups and polymerizable unsaturated groups (B1)," and the organic solvent can be used alone or in combination of two or more types.
As the basic catalyst, the same basic catalyst as described in the section above, "Epoxy resin having acidic groups and polymerizable unsaturated groups (B1)," can be used, and the basic catalyst can be used alone or in combination of two or more types.

In this embodiment, the acid value of the acrylic resin (B3) having acidic groups and polymerizable unsaturated groups is preferably in the range of 30 to 150 mg KOH/g, and more preferably in the range of 40 to 120 mg KOH/g, from the viewpoint of more effectively improving photosensitivity, developability, heat resistance, and/or coating film appearance.

<Amido-imide resin (B4) having acidic groups and polymerizable unsaturated groups>
In this embodiment, the amide-imide resin (B4) having an acid group and a polymerizable unsaturated group can be, for example, obtained by reacting an amide-imide resin (b4-1) having an acid group and/or an acid anhydride group with a (meth)acrylate compound (b1-5) having a hydroxyl group and/or an epoxy group with a compound having one or more reactive functional groups selected from the group consisting of a hydroxyl group, a carboxyl group, an isocyanate group, a glycidyl group, and an acid anhydride group. The compound having the reactive functional group may or may not have a (meth)acryloyl group.
The amide-imide resin (b4-1) having acid groups and/or acid anhydride groups may have only one of them, or both. From the viewpoint of reactivity and reaction control with (meth)acrylate compounds (1-5) having hydroxyl groups or epoxy compounds having (meth)acryloyl groups, it is preferable that the amide-imide resin (b4-1) has acid anhydride groups, and more preferably that it has both acid groups and acid anhydride groups. The solid content acid value of the amide-imide resin (b4-1) is preferably in the range of 60 to 350 mgKOH/g when measured under neutral conditions, i.e., conditions in which the acid anhydride groups are not ring-opened. On the other hand, it is preferable that the measured value is in the range of 61 to 360 mgKOH/g when measured under conditions in which the acid anhydride groups are ring-opened, such as in the presence of water.

Furthermore, the amide-imide resin (b4-1) can, if necessary, be used in combination with polybasic acids as reaction raw materials, in addition to polyisocyanate compounds (b1-4) and polybasic acid anhydrides (b1-3).

Any compound having two or more carboxyl groups in one molecule can be used as the polybasic acid mentioned above. For example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, methylhexahydrophthalic acid, citraconic acid, itaconic acid, glutaconic acid, 1,2,3,4-butanetetracarboxylic acid, cyclohexanetricarboxylic acid, cyclohexanetetracarboxylic acid, bicyclo[2.2.1]heptane-2,3 Examples of polybasic acids include dicarboxylic acids, methylbicyclo[2.2.1]heptane-2,3-dicarboxylic acid, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid, trimellitic acid, pyromellitic acid, naphthalenedicarboxylic acid, naphthalentricarboxylic acid, naphthalenetetracarboxylic acid, biphenyldicarboxylic acid, biphenyltricarboxylic acid, biphenyltetracarboxylic acid, and benzophenonetetracarboxylic acid. In addition, as the polybasic acid, for example, a copolymer of a conjugated diene vinyl monomer and acrylonitrile having a carboxyl group in its molecule can also be used.
The polybasic acids mentioned above can be used individually or in combination of two or more.

The above-mentioned (meth)acrylate compounds having an epoxy group are not particularly limited in their specific structure as long as they have a (meth)acryloyl group and an epoxy group in their molecular structure, and a wide variety of compounds can be used. For example, examples include glycidyl group-containing (meth)acrylate monomers such as glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, and epoxycyclohexylmethyl (meth)acrylate, as well as mono(meth)acrylate compounds of diglycidyl ether compounds such as hydroxybenzene diglycidyl ether, dihydroxynaphthalene diglycidyl ether, biphenol diglycidyl ether, and bisphenol diglycidyl ether.
The (meth)acrylate compounds having the epoxy group described above can be used alone or in combination of two or more.

Furthermore, the specific structure or manufacturing method of the amide-imide resin (b4-1) having acid groups and/or acid anhydride groups is not particularly limited, and general amide-imide resins can be widely used. The amide-imide resin (b4-1) in this embodiment is preferably obtained using a polyisocyanate compound (b1-4) and a polybasic acid anhydride (b1-3) as reaction raw materials.
Furthermore, in this embodiment, as the polyisocyanate compound (b1-4), a resin composition having acidic groups with high solvent solubility and polymerizable unsaturated groups can be obtained. Therefore, alicyclic diisocyanate compounds or modified versions thereof, aliphatic diisocyanate compounds or modified versions thereof are preferred, and alicyclic diisocyanates or their isocyanurate modified versions, aliphatic diisocyanates or their isocyanurate modified versions are more preferred.
In this embodiment, the total mass ratio of alicyclic diisocyanate compounds or their modified counterparts to aliphatic diisocyanate compounds or their modified counterparts in the total mass of the polyisocyanate compounds (b1-4) is preferably 70% by mass or more, and preferably 90% by mass or more.
Furthermore, when using an alicyclic diisocyanate compound or a modified version thereof in combination with an aliphatic diisocyanate compound or a modified version thereof, it is preferable that the mass ratio of the two (alicyclic diisocyanate compound or modified version thereof / aliphatic diisocyanate compound or modified version thereof) is in the range of 30/70 to 70/30.

The method for producing the amide-imide resin (B4) having acidic groups and polymerizable unsaturated groups is not particularly limited and can be any method. In producing the amide-imide resin (B4) having acidic groups and polymerizable unsaturated groups, the process may be carried out in an organic solvent as needed, and a basic catalyst may also be used as needed.
As the basic catalyst, the same basic catalyst as described in the section above, "<Epoxy resin having acidic groups and polymerizable unsaturated groups (B1)>", can be used, and the basic catalyst can be used alone or in combination of two or more types.
Furthermore, the organic solvent can be the same as the organic solvent described in the section above for "Epoxy resin having acidic groups and polymerizable unsaturated groups (B1)," and the organic solvent can be used alone or in combination of two or more types.

The amide-imide resin (B4) having acid groups and polymerizable unsaturated groups can be used in combination with other reaction materials in addition to the amide-imide resin (b4-1) having acid groups and/or acid anhydride groups, the hydroxyl group-containing (meth)acrylate compound (b1-5), and/or the epoxy group-containing (meth)acrylate compound (b4-2), depending on the desired resin performance. In this case, the total mass ratio of the components (b4-1) to (b4-2) in the total mass of the reaction materials for the resin (B4) having acid groups and polymerizable unsaturated groups is preferably 80% by mass or more, and more preferably 90% by mass or more.

The method for producing the amide-imide resin (B4) having acidic groups and polymerizable unsaturated groups is not particularly limited, and any method may be used. For example, it may be produced by reacting all the reaction materials, including the amide-imide resin (b4-1) and the hydroxyl group-containing (meth)acrylate compound (b1-5) and/or the epoxy group-containing (meth)acrylate compound (b4-2), all at once, or by reacting the reaction materials sequentially. Furthermore, for example, the reaction between the amide-imide resin (b4-1) and the hydroxyl group-containing (meth)acrylate compound (b1-5) can be carried out by heating and stirring under a temperature of approximately 80 to 140°C in the presence of a suitable basic catalyst. In the production of the amide-imide resin (B4) having acidic groups and polymerizable unsaturated groups, the process may be carried out in an organic solvent as needed, and a basic catalyst or an acidic catalyst may be used as needed.

The basic catalyst described above can be the same as the acidic catalyst and basic catalyst described in the section above, "Epoxy resin having acidic groups and polymerizable unsaturated groups (B1)," and these can be used individually or in combination of two or more.
Examples of the above-mentioned acidic catalysts include inorganic acids such as hydrochloric acid, sulfuric acid, and phosphoric acid; organic acids such as methanesulfonic acid, p-toluenesulfonic acid, and oxalic acid; and Lewis acids such as boron trifluoride, anhydrous aluminum chloride, and zinc chloride. Solid acid catalysts having strong acids such as sulfonyl groups can also be used. These acidic catalysts can be used individually or in combination of two or more types.

The acid value of the amide-imide resin (B4) having acid groups and polymerizable unsaturated groups is preferably in the range of 30 to 150 mg KOH/g, and more preferably in the range of 40 to 120 mg KOH/g, from the viewpoint of more effectively improving photosensitivity, developability, heat resistance, and/or coating film appearance.

<Acrylamide resin (B5) having acidic groups and polymerizable unsaturated groups>
Examples of the acrylamide resin (B5) having acidic groups and polymerizable unsaturated groups in this embodiment include a resin obtained by reacting a phenolic hydroxyl group-containing compound (b5-1), an alkylene carbonate (b5-2a) or alkylene oxide (b5-2b), an N-alkoxyalkyl (meth)acrylamide compound (b5-3), a polybasic acid anhydride (b1-3), and optionally an unsaturated monobasic acid (b1-2) as reaction raw materials.

In this embodiment, the phenolic hydroxyl group-containing compound (b5-1) refers to a compound having at least one phenolic hydroxyl group in its molecule. Examples of the phenolic hydroxyl group-containing compound (b5-1) include a compound represented by any of the following general formulas (8.1) to (8.5), a reaction product using an aromatic polyhydroxy compound (b5-4) and a compound represented by any of the following general formulas (9.1) to (9.5) as essential reaction raw materials, or a novolac-type phenolic resin using one or more aromatic polyhydroxy compounds (b5-4) or other compounds (b5-5) having one phenolic hydroxyl group in their molecule as reaction raw materials.
[In the above general formulas (8.1) to (8.5), R ⁸¹ to R ⁸⁴ and R ⁸⁷ each independently represent one of an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryl group, or a halogen atom; R ⁸⁵ and R ⁸⁶ each independently represent a hydrogen atom or a methyl group; j ⁸¹ to j ⁸⁵ each independently represent 0 or an integer of 1 or more, preferably 0 or an integer from 1 to 3, more preferably 0 or 1; ^{k 81} to k ⁸⁵ each independently represent an integer of 1 or more, preferably 2 or 3.]
Furthermore, the positions of the substituents on the aromatic rings in the above general formulas (8.1) to (8.5) are arbitrary. For example, in the naphthalene ring of general formula (8.2), the substituent may substitute for any hydrogen atom on the ring; in general formula (8.3), it may substitute for any hydrogen atom on the benzene ring present in one biphenyl molecule; in general formula (8.4), it may substitute for any hydrogen atom on the benzene ring present in one aralkyl molecule; and in general formula (8.5), it may substitute for any hydrogen atom on the benzene ring present in one molecule. This indicates that the number of substituents in one molecule is j ⁸¹ to j ⁸⁵ and k ⁸¹ to k ⁸⁵ .
[In the above general formulas (9.1) to (9.5), h ⁹¹ represents 0 or 1, R ⁹¹ to R ⁹⁶ each independently represent one of a monovalent aliphatic hydrocarbon group, alkoxy group, halogen atom, aryl group, aryloxy group, or aralkyl group, k ⁹¹ to k ⁹⁶ each independently represent 0 or an integer from 1 to 4, Z ⁹¹ to Z ⁹⁶ each independently represent one of a vinyl group, halomethyl group, hydroxymethyl group, or alkyloxymethyl group, Y ⁹¹ represents one of an alkylene group having 1 to 4 carbon atoms, an oxygen atom, a sulfur atom, or a carbonyl group, and n ⁹¹ represents an integer from 1 to 4.]
The compounds represented by the above general formulas (9.1) to (9.5) can be used individually or in combination of two or more.

Examples of aromatic polyhydroxy compounds (b5-4) include dihydroxybenzene, trihydroxybenzene, tetrahydroxybenzene, dihydroxynaphthalene, trihydroxynaphthalene, tetrahydroxynaphthalene, dihydroxyanthracene, trihydroxyanthracene, tetrahydroxyanthracene, biphenol, tetrahydroxybiphenyl, bisphenol, and compounds having one or more substituents on these aromatic nuclei. Furthermore, examples of substituents on the aromatic nucleus include monovalent aliphatic hydrocarbon groups such as methyl, ethyl, vinyl, propyl, butyl, pentyl, hexyl, cyclohexyl, heptyl, octyl, and nonyl groups; alkoxy groups such as methoxy, ethoxy, propyloxy, and butoxy groups; halogen atoms such as fluorine, chlorine, and bromine atoms; phenyl, naphthyl, and anthryl groups, and aryl groups on which the aliphatic hydrocarbon groups, alkoxy groups, halogen atoms, etc. are substituted on these aromatic nuclei; phenyloxy and naphthyloxy groups, and aryloxy groups on which the aliphatic hydrocarbon groups, alkoxy groups, halogen atoms, etc. are substituted on these aromatic nuclei; phenylmethyl, phenylethyl, naphthylmethyl, naphthylethyl groups, and aralkyl groups on which the aliphatic hydrocarbon groups, alkoxy groups, halogen atoms, etc. are substituted on these aromatic nuclei. These aromatic polyhydroxy compounds can be used individually or in combination of two or more. Among these, compounds that do not contain halogens are preferred because they yield resins with acidic groups and polymerizable unsaturated groups that have high insulating reliability.

Examples of the novolac-type phenolic resin mentioned above include resins obtained by reacting one or more compounds having one phenolic hydroxyl group in their molecule with an aldehyde compound under acidic catalyst conditions.

The above-mentioned compounds having one phenolic hydroxyl group in their molecule (b5-5) can be any aromatic compound having one hydroxyl group on its aromatic nucleus. Examples include phenol or phenol compounds having one or more substituents on the phenolic nucleus, naphthol or naphthol compounds having one or more substituents on the naphthol nucleus, anthracenol or anthracenol compounds having one or more substituents on the anthracenol nucleus, etc. Examples of substituents on the aromatic nucleus include monovalent aliphatic hydrocarbon groups, alkoxy groups, halogen atoms, aryl groups, aryloxy groups, aralkyl groups, etc., with specific examples given above. These compounds having one phenolic hydroxyl group can be used individually or in combination of two or more.

Examples of the above aldehyde compounds include formaldehyde; alkyl aldehydes such as acetaldehyde, propylaldehyde, butyraldehyde, isobutyraldehyde, pentylaldehyde, and hexylaldehyde; hydroxybenzaldehydes such as salicylaldehyde, 3-hydroxybenzaldehyde, 4-hydroxybenzaldehyde, 2-hydroxy-4-methylbenzaldehyde, 2,4-dihydroxybenzaldehyde, and 3,4-dihydroxybenzaldehyde; and 2-hydroxy-3-methoxybenzaldehyde and 3-hydroxy-4-methoxybenzaldehyde. Examples include aldehydes, benzaldehydes having both hydroxyl and alkoxy groups such as 4-hydroxy-3-methoxybenzaldehyde, 3-ethoxy-4-hydroxybenzaldehyde, and 4-hydroxy-3,5-dimethoxybenzaldehyde; alkoxybenzaldehydes such as methoxybenzaldehyde and ethoxybenzaldehyde; hydroxynaphthaldehydes such as 1-hydroxy-2-naphthaldehyde, 2-hydroxy-1-naphthaldehyde, and 6-hydroxy-2-naphthaldehyde; and halogenated benzaldehydes such as bromobenzaldehyde.

Examples of alkylene carbonates (b5-2a) include ethylene carbonate, propylene carbonate, butylene carbonate, and pentylene carbonate. Among these, ethylene carbonate or propylene carbonate are preferred from the viewpoint of the resin composition exhibiting higher photosensitivity and developability, and the resulting cured product (cured coating) exhibiting superior heat resistance and coating appearance. The alkylene carbonate can be used alone or in combination of two or more types.

Examples of alkylene oxides (b5-2b) include ethylene oxide, propylene oxide, butylene oxide, and pentylene oxide. Among these, ethylene oxide or propylene oxide are preferred from the viewpoint of the resin composition exhibiting higher photosensitivity and developability, and the resulting cured product (cured coating) exhibiting superior heat resistance and coating appearance. The alkylene oxide can be used alone or in combination of two or more types.

Examples of N-alkoxyalkyl(meth)acrylamide compounds (b5-3) include N-methoxymethyl(meth)acrylamide, N-ethoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, N-methoxyethyl(meth)acrylamide, N-ethoxyethyl(meth)acrylamide, and N-butoxyethyl(meth)acrylamide. Among these, N-methoxymethyl(meth)acrylamide is preferred from the viewpoint of the resin composition exhibiting higher photosensitivity and developability, and the resulting cured product (cured coating film) exhibiting better heat resistance and coating film appearance.
N-alkoxyalkyl(meth)acrylamide compounds (b5-3) can be used alone or in combination of two or more.

In this embodiment, when the N-alkoxyalkyl (meth)acrylamide compound (b5-3) is used as a reaction raw material for the acrylamide resin (B5) having acidic groups and polymerizable unsaturated groups, the equivalent ratio [(b5-3)/(b1-3)] of the N-alkoxyalkyl (meth)acrylamide compound (b5-3) to the polybasic acid anhydride (b1-3) is preferably in the range of 0.2 to 7, and more preferably in the range of 0.25 to 6.7, from the viewpoint of the resin composition exhibiting higher photosensitivity and developability, and the resulting cured product (cured coating film) exhibiting superior heat resistance and coating film appearance.

In this embodiment, the method for producing the acrylamide resin (B5) having acidic groups and polymerizable unsaturated groups is not particularly limited and can be used by any method. For example, it may be produced by reacting all the reaction materials at once, or by reacting the reaction materials sequentially. Among these, a preferred method is to first react a phenolic hydroxyl group-containing compound (b5-1) with an alkylene carbonate (b5-2a) or alkylene oxide (b5-2b) (for example, in the presence of a basic catalyst at a temperature range of 100 to 200°C), then react an unsaturated monobasic acid (b1-2) and/or an N-alkoxyalkyl (meth)acrylamide compound (b2-3b) (for example, in the presence of an acidic catalyst at a temperature range of 80 to 140°C), and finally react a polybasic acid anhydride (b1-3) (for example, at a temperature range of 80 to 140°C), as this method allows for easy control of the reaction.

The acrylamide resin (B5) having acidic groups and polymerizable unsaturated groups in this embodiment is a resin obtained from the above-mentioned reaction raw materials. For example, the acrylamide resin (B5) may be a resin having a resin structure in which structural units are repeatedly composed of structural units (I) represented by the following general formula (10.1) and structural units (II) represented by the following general formula (10.2), or a resin having a resin structure in which structural units are repeatedly composed of structural units (III) represented by the following formula (10.3) and structural units (IV) represented by the following formula (10.4).
[In the above formula (10.1) or (10.2), R ^b2 and R ^b8 each independently represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 4 carbon atoms, R ^b3 and R ^b9 each independently represent any of a hydrogen atom, a hydrocarbon group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom, n ¹ and n ² each independently represent 1 or 2, R ^b4 and R ^b10 each independently represent a methylene group or a structural part represented by any of the following general formulas (11.1) to (11.5), R ^b5 and R ^b6 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, provided that R ^b5 and R ^b6 are linked to form a saturated or unsaturated ring, R ^b11 represents a divalent hydrocarbon group having 1 to 12 carbon atoms, R ^b12 represents a hydrogen atom or a methyl group, and R ^b1 and R ^b7 are, independently, bond points where the groups represented by R ^b3 and R ^b9 , or structural site (I) represented by formula (10.1) or structural site (II) represented by formula (10.2), are connected via R ^b4 or R ^b10 , which are marked with an asterisk.
[In the above general formula (10.3) or (10.4), R ^b2 and R ^b8 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, R ^b3 and R ^b9 each independently represent any of a hydrogen atom, a hydrocarbon group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom, n ³ and n ⁴ each independently represent 1 or 2, R ^b4 and R ^b10 each independently represent a methylene group or a structural part represented by any of the following formulas (11.1) to (11.5), R ^b5 and R ^b6 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, provided that R ^b5 and R ^b6 are linked to form a saturated or unsaturated ring, R ^b11 represents a divalent hydrocarbon group having 1 to 12 carbon atoms, R ^b12 represents a hydrogen atom or a methyl group, and R ^b1 and R ^b7 are, independently, bond points where the groups represented by R ^b3 and R ^b9 , or structural site (III) represented by general formula (10.3) or structural site (IV) represented by general formula (10.4), are connected via R ^b4 or R ^b10 , which are marked with an asterisk.
[In the above general formulas (11.1) to (11.5), h ⁹¹ represents 0 or 1, R ⁹¹ to R ⁹⁶ each independently represent one of a monovalent aliphatic hydrocarbon group, alkoxy group, halogen atom, aryl group, or aralkyl group, n ⁹¹ to n ⁹⁶ each independently represent 0 or an integer from 1 to 4, Y ⁹¹ represents one of an alkylene group having 1 to 4 carbon atoms, an oxygen atom, a sulfur atom, or a carbonyl group, n ⁹¹ represents an integer from 1 to 4, R ¹¹¹ to R ¹¹⁶ each independently represent a hydrogen atom or a methyl group, and W represents the following formula (12.1) or (12.2).]
[In formulas (12.1) or (12.2) above, R ¹²¹ and R ¹²⁴ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, R ¹²² and R ¹²³ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, provided that R ¹²² and R ¹²³ are linked to form a saturated or unsaturated ring, R ¹²⁵ represents a divalent hydrocarbon group having 1 to 12 carbon atoms, and R ¹²⁶ represents a hydrogen atom or a methyl group.]

The acid value of the acrylamide resin (B5) having acidic groups and polymerizable unsaturated groups is preferably in the range of 30 to 150 mg KOH/g, and more preferably in the range of 40 to 120 mg KOH/g, from the viewpoint of the resin composition exhibiting higher photosensitivity and developability, and the resulting cured product (cured coating) exhibiting superior heat resistance and coating appearance.

<Ester resin (B6) having acidic groups and polymerizable unsaturated groups>
Examples of ester resins (B6) having acidic groups and polymerizable unsaturated groups include resins obtained by reacting a phenolic hydroxyl group-containing compound (b5-1) with an alkylene oxide (b5-2b) or alkylene carbonate (b5-2a) with an unsaturated monobasic acid (b1-2) and a polybasic acid anhydride (b1-3).

As the alkylene oxide (b5-2b), the same as those exemplified above as alkylene oxide (b5-2b) can be used. Among these, ethylene oxide or propylene oxide is preferred from the viewpoint of more effectively improving light sensitivity, developability, heat resistance and/or coating film appearance.
Alkylene oxide (b5-2b) can be used alone or in combination of two or more types.

As the alkylene carbonate (b5-2a) mentioned above, the same type as the example alkylene carbonate (b5-2a) described above can be used. Among these, ethylene carbonate or propylene carbonate is preferred from the viewpoint of more effectively improving light sensitivity, developability, heat resistance and/or coating film appearance.
Alkylene carbonate (b5-2a) can be used alone or in combination of two or more types.

The method for producing the ester resin (B6) having acidic groups and polymerizable unsaturated groups is not particularly limited and may be any method. The production of the ester resin having acidic groups and polymerizable unsaturated groups may be carried out in an organic solvent as needed, and basic catalysts and acidic catalysts may also be used as needed.

The above-mentioned organic solvent can be the same as those exemplified above, and it can be used alone or in combination of two or more types. The above-mentioned basic catalyst can be the same as those exemplified above, and it can be used alone or in combination of two or more types. The above-mentioned acidic catalyst can be the same as those exemplified above, and it can be used alone or in combination of two or more types.

(Compounds having polymerizable unsaturated groups)
The resin composition of this embodiment may further contain a compound having a polymerizable unsaturated group in addition to the maleimide resin (A) and resin (B). Such a compound having a polymerizable unsaturated group is typically a compound that does not have an acid group.

Examples of compounds having the polymerizable unsaturated group mentioned above include (meth)acrylate compounds, specifically, 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; alicyclic mono(meth)acrylate compounds such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and adamantyl mono(meth)acrylate; heterocyclic mono(meth)acrylate compounds such as glycidyl (meth)acrylate and tetrahydrofurfuryl acrylate; and benzyl (meth) Mono(meth)acrylate compounds such as aromatic mono(meth)acrylate compounds including acrylate, phenyl(meth)acrylate, phenylbenzyl(meth)acrylate, phenoxy(meth)acrylate, phenoxyethyl(meth)acrylate, phenoxyethoxyethyl(meth)acrylate, 2-hydroxy-3-phenoxypropyl(meth)acrylate, phenoxybenzyl(meth)acrylate, benzylbenzyl(meth)acrylate, phenylphenoxyethyl(meth)acrylate, etc.: (Poly)oxyalkylene compounds obtained by introducing polyoxyalkylene chains such as (poly)oxyethylene chains, (poly)oxypropylene chains, and (poly)oxytetramethylene chains into the molecular structure of the above-mentioned various mono(meth)acrylate monomers. Aliphatic mono(meth)acrylate compounds; lactone-modified mono(meth)acrylate compounds in which a (poly)lactone structure is introduced into the molecular structure of the above-mentioned 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, neopentyl glycol di(meth)acrylate; alicyclic di(meth)acrylate compounds such as 1,4-cyclohexanedimethanol di(meth)acrylate, norbornane di(meth)acrylate, norbornane dimethanol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate Meth)acrylate compounds; aromatic di(meth)acrylate compounds such as biphenol di(meth)acrylate and bisphenol di(meth)acrylate; polyoxyalkylene-modified di(meth)acrylate compounds obtained by introducing (poly)oxyalkylene chains such as (poly)oxyethylene chains, (poly)oxypropylene chains, and (poly)oxytetramethylene chains into the molecular structure of the various di(meth)acrylate compounds; lactone-modified di(meth)acrylate compounds obtained by introducing (poly)lactone structures into the molecular structure of the various di(meth)acrylate compounds; aliphatic tri(meth)acrylate compounds such as trimethylolpropane tri(meth)acrylate and glycerin tri(meth)acrylate; fractions of the aliphatic tri(meth)acrylate compounds (Poly)oxyalkylene-modified tri(meth)acrylate compounds having (poly)oxyalkylene chains such as (poly)oxyethylene chains, (poly)oxypropylene chains, and (poly)oxytetramethylene chains introduced into the molecular structure; lactone-modified tri(meth)acrylate compounds having a (poly)lactone structure introduced into the molecular structure of the aliphatic tri(meth)acrylate compound; tetrafunctional or more aliphatic poly(meth)acrylate compounds such as pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate; (poly)oxyalkylene chains such as (poly)oxyethylene chains, (poly)oxypropylene chains, and (poly)oxytetramethylene chains introduced into the molecular structure of the aliphatic poly(meth)acrylate compound; (Poly)oxyalkylene-modified poly(meth)acrylate compounds with four or more functions, in which (poly)oxyalkylene chains such as ion chains are introduced; lactone-modified poly(meth)acrylate compounds with four or more functions, in which a (poly)lactone structure is introduced into the molecular structure of the aliphatic poly(meth)acrylate compound; hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, trimethylolpropane (meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol (meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol (Meth)acrylate compounds having hydroxyl groups, such as thritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, ditrimethylolpropane(meth)acrylate, ditrimethylolpropanedi(meth)acrylate, and ditrimethylolpropanetri(meth)acrylate; (Poly)oxyalkylene modified compounds in which (poly)oxyalkylene chains such as (poly)oxyethylene chains, (poly)oxypropylene chains, and (poly)oxytetramethylene chains are introduced into the molecular structure of the hydroxyl group-containing (meth)acrylate compounds; lactone modified compounds in which a (poly)lactone structure is introduced into the molecular structure of the hydroxyl group-containing (meth)acrylate compounds; 2-acryloyl Examples include (meth)acrylate compounds having an isocyanate group, such as oxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, and 1,1-bis(acryloyloxymethyl)ethyl isocyanate; (meth)acrylate monomers having a glycidyl group, such as glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, and epoxycyclohexylmethyl (meth)acrylate; and (meth)acrylate compounds having an epoxy group, such as mono(meth)acrylates of diglycidyl ether compounds of droxybenzene diglycidyl ether, dihydroxynaphthalene diglycidyl ether, biphenol diglycidyl ether, and bisphenol diglycidyl ether.
Compounds having polymerizable unsaturated groups may be used individually or in combination of two or more.

(Photopolymerization initiator)
As described above, the resin composition of this embodiment may further contain a photopolymerization initiator in addition to the maleimide resin (A) and resin (B) (and any compound having a polymerizable unsaturated group). A resin composition containing a photopolymerization initiator is, in other words, a curable resin composition. The photopolymerization initiator may be used alone or in combination of two or more types.

The photopolymerization initiator can be selected and used appropriately depending on the type of active energy ray used for irradiation. It may also be used in combination with photosensitizers such as amine compounds, urea compounds, sulfur-containing compounds, phosphorus-containing compounds, chlorine-containing compounds, and nitrile compounds. Furthermore, the photopolymerization initiator is preferably a radical polymerization initiator. Specific examples of such photopolymerization initiators include alkylphenone-based photopolymerization initiators such as 1-hydroxycyclohexylphenyl-ketone, 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-trimethylbenzoyl-diphenylphosphine oxide; and intramolecular hydrogen abstraction type 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, thioxanthones and thioxanthone derivatives, 2,2'-dimethoxy-1,2-diphenylethane-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.

Examples of commercially available photopolymerization initiators include "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 "Omn Examples include "Irad-81" (manufactured by IGM), "KayaCure-DETX," "KayaCure-MBP," "KayaCure-DMBI," "KayaCure-EPA," and "KayaCure-OA" (manufactured by Nippon Kayaku Co., Ltd.), "ByCure-10" and "ByCure-55" (manufactured by Stauffa Chemicals), "Trigonal P1" (manufactured by Akzo), "Sandoz 1000" (manufactured by Sandoz), "Deep" (manufactured by Apjohn), "Quantacure-PDO," "Quantacure-ITX," and "Quantacure-EPD" (manufactured by Wardbrenkinsop), and "Runtecure-1104" (manufactured by Runtec).

When using a photopolymerization initiator, the content of the photopolymerization initiator in the resin composition of this embodiment is preferably 0.1 parts by mass or more and 10 parts by mass or less, based on 100 parts by mass of the total of the maleimide resin (A) and the resin (B) having acidic groups and polymerizable unsaturated groups.

(Optional addition ingredient)
As described above, the resin composition of this embodiment may further contain optional additives, as long as it does not deviate from its purpose. Examples of optional additives include curing agents, curing accelerators, other resins, organic solvents, polymerization inhibitors, antioxidants, flame retardants, fillers, pigments, defoamers, viscosity modifiers, leveling agents, UV stabilizers, and preservation stabilizers.

<Hardening agent>
Examples of curing agents include epoxy resins and other curing agents (amine curing agents, acid anhydride curing agents, phenolic resin curing agents, etc.), but epoxy resins are preferred among these.

The epoxy resin is not particularly limited, but is preferably a curable resin that contains two or more epoxy groups in its molecule and can be cured by forming a crosslinked network with the epoxy groups. The epoxy resin is not particularly limited, but may include novolac type epoxy resins such as phenol novolac type epoxy resin, cresol novolac type epoxy resin, α-naphthol novolac type epoxy resin, β-naphthol novolac type epoxy resin, bisphenol A novolac type epoxy resin, and biphenyl novolac type epoxy resin;
Aralkyl epoxy resins such as phenol aralkyl epoxy resins, naphthol aralkyl epoxy resins, and phenol biphenyl aralkyl epoxy resins;
Bisphenol-type epoxy resins such as bisphenol A type epoxy resin, bisphenol AP type epoxy resin, bisphenol AF type epoxy resin, bisphenol B type epoxy resin, bisphenol BP type epoxy resin, bisphenol C type epoxy resin, bisphenol E type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, tetrabromobisphenol A type epoxy resin, etc.
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 dicyclopentadienephenol-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;
Examples include benzopyran-type epoxy resins such as dibenzopyran, hexamethyldibenzopyran, and 7-phenylhexamethyldibenzopyran.
Of these epoxy resins, so-called glycidyl ether type epoxy resins obtained by epoxidizing phenol compounds are preferred, and among these, novolac type epoxy resins, aralkyl type epoxy resins, and dicyclopentadiene type epoxy resins are more preferred from the viewpoint of dielectric properties. The above epoxy resins may be used individually or in combination of two or more types.

The epoxy equivalent of the epoxy resin is preferably 120 to 400 g/eq, and more preferably 150 to 300 g/eq. A epoxy equivalent of 120 g/eq or more is preferred because it results in superior dielectric properties of the resulting cured product. On the other hand, a epoxy equivalent of 400 g/eq or less is preferred because it provides an excellent balance between the heat resistance and dielectric loss tangent of the resulting cured product.

The softening point of epoxy resin is preferably 20 to 200°C, and more preferably 40 to 150°C, from the viewpoint of achieving a good balance of light sensitivity, developability, heat resistance, and coating film appearance.

The amine curing agent is not particularly limited, but examples include aliphatic amines such as diethylenetriamine (DTA), triethylenetetramine (TTA), tetraethylenepentamine (TEPA), diproprendiamine (DPDA), diethylaminopropylamine (DEAPA), N-aminoethylpiperazine, mensendiamine (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, benzophenonetetracarboxylic anhydride, ethylene glycol bistrimellitate, glycerol trimellitate, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, methylbutenyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, succinic anhydride, and methylcyclohexenedicarboxylic anhydride.

Examples of phenolic resin curing agents 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 phenolic resin.
The other hardening agents mentioned above may be used individually or in combination of two or more.

When a curing agent is used, the curing agent content in the resin composition of this embodiment is preferably 10 to 40 parts by mass per 100 parts by mass of the total amount of maleimide resin (A) and resin (B). A content of 10 parts by mass or more can further improve heat resistance and curability, while a content of 40 parts by mass or less can result in a lower dielectric loss tangent and higher flexibility.

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

Examples of the phosphorus-based curing accelerators mentioned above include organic phosphine compounds such as triphenylphosphine, tributylphosphine, triparatlylphosphine, diphenylcyclohexylphosphine, and tricyclohexylphosphine; organic phosphite compounds such as trimethylphosphite and triethylphosphite; 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 above-mentioned amine-based curing accelerators 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-ethyl-4-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-methylimidazolin.

Examples of the above-mentioned 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]deca-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]deca-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-butylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, and 1-phenylbiguanide.

Examples of the above-mentioned urea-based curing accelerators 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 curing accelerators mentioned above, 2-ethyl-4-methylimidazole and N,N-dimethyl-4-aminopyridine (DMAP) are preferred.

When a curing accelerator is used, the content of the curing accelerator in the resin composition of this embodiment is preferably 0.01 to 5 parts by mass per 100 parts by mass of the total amount of maleimide resin (A) and resin (B). A curing accelerator content of 0.01 parts by mass or more can more reliably improve curability. On the other hand, a curing accelerator content of 5 parts by mass or less can maintain sufficiently good insulation reliability. From a similar viewpoint, the curing accelerator content is more preferably 0.1 parts by mass or more, and even more preferably 5 parts by mass or less, per 100 parts by mass of the total amount of maleimide resin (A) and resin (B).

<Other resins>
Other resins are not particularly limited, but include maleimide resins other than maleimide resin (A), polyphenylene ether resins, polyimide resins, cyanate ester resins, benzoxazine resins, triazine-containing cresol novolac resins, cyanate ester resins, styrene-maleic anhydride resins, allyl group-containing resins such as diallylbisphenol and triallyl isocyanurate, polyphosphate esters, phosphate ester-carbonate copolymers, and the like. These other resins may be used individually or in combination of two or more.

When other resins are used, it is preferable that the content of the other resins in the resin composition of this embodiment be 50% by mass or less of the total.

<Organic Solvents>
Organic solvents can have the function of adjusting the viscosity of the resin composition. Specific examples of organic solvents are not particularly limited, but include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether solvents such as diethyl ether and tetrahydrofuran; ester solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitols such as cellosolve and butyl carbitol; aromatic hydrocarbons such as toluene, xylene, ethylbenzene, mesitylene, 1,2,3-trimethylbenzene, and 1,2,4-trimethylbenzene; and amide solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. Organic solvents may be used individually or in combination of two or more types.

When using an organic solvent, the content of the organic solvent in the resin composition of this embodiment is preferably 90% by mass or less, more preferably 10 to 90% by mass, and even more preferably 20 to 80% by mass, based on the total amount (100% by mass) of the resin composition. An organic solvent content of 10% by mass or more is preferable due to its excellent handling properties. On the other hand, an organic solvent content of 90% by mass or less is preferable from an economic standpoint.

<Polymerization inhibitors>
Polymerization inhibitors are not particularly limited, but include phenol compounds such as p-methoxyphenol (methoquinone), p-methoxycresol, 4-methoxy-1-naphthol, 4,4'-dialkoxy-2,2'-bi-1-naphthol, 3-(N-salicyroyl)amino-1,2,4-triazole, N'1,N'12-bis(2-hydroxybenzoyl)dodecanedihydrazide, styrene-phenol, N-isopropyl-N'-phenylbenzene-1,4-diamine, 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline; quinone compounds such as hydroquinone, methylhydroquinone, p-benzoquinone, methyl-p-benzoquinone, 2,5-diphenylbenzoquinone, 2-hydroxy-1,4-naphthoquinone, anthraquinone, and diphenoquinone; melamine, p-phenylenediamine, 4-aminodiphenylamine, N. Amine compounds such as 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), styrene-diphenylamine, reaction products of styrene-diphenylamine and 2,4,4-trimethylpentene, reaction products of diphenylamine and 2,4,4-trimethylpentene; phenothiazine, distearylthiodipropionate, 2,2-bis({[3-(dodecylthio)propionyl]oxy}methyl)-1,3-propanediyl=bis[3-(dodecylthio)propionate], ditridecane-1-yl= Thioether compounds such as 3,3'-sulfandiyldipropanoate; N-nitrosodiphenylamine, N-nitrosophenylnaphthylamine, p-nitrosophenol, nitrosobenzene, p-nitrosodiphenylamine, α-nitroso-β-naphthol, N,N-dimethylp-nitrosoaniline, p-nitrosodiphenylamine, p-nitronedimethylamine, p-nitrone-N,N-diethylamine, N-nitrosoethanolamine, N-nitrosodi-n-butylamine, N-nitroso-N-n-butyl-4-butanolamine, N-nitrosodiisopropanolamine, N-nitroso-N-ethyl-4-butanolamine, 5-nitroso-8-hydroxyquinoline, N-nitrosomorpholine, N-nitroso-N-phenylhydroxylamine ammonium salt, nitrosobenzene, N- Nitroso compounds such as nitroso-N-methyl-p-toluenesulfonamide, N-nitroso-N-ethylurethane, N-nitroso-N-n-propylurethane, 1-nitroso-2-naphthol, 2-nitroso-1-naphthol, 1-nitroso-2-naphthol-3,6-sodium sulfonate, 2-nitroso-1-naphthol-4-sodium sulfonate, 2-nitroso-5-methylaminophenol hydrochloride, and 2-nitroso-5-methylaminophenol hydrochloride; esters of phosphoric acid and octadecane-1-ol, triphenyl phosphite, 3,9-dioctadecane-1-yl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, trisnonylphenyl phosphite, phosphorous acid-(1-methylethylidene)-di-4,1-phenylenetetra-C12-15-alkyl Examples include phosphate compounds such as esters, 2-ethylhexyl diphenyl phosphite, diphenylisodecyl phosphite, triisodecyl phosphite, and tris(2,4-di-tert-butylphenyl) phosphite; zinc compounds such as bis(dimethyldithiocarbamato-κ(2)S,S')zinc, diethyldithiocarbamate zinc, and dibutyldithiocarbamate zinc; nickel compounds such as bis(N,N-dibutylcarbamodithioato-S,S')nickel; and sulfur compounds such as 1,3-dihydro-2H-benzimidazole-2-thion, 4,6-bis(octylthiomethyl)-o-cresol, 2-methyl-4,6-bis[(octan-1-ylsulfanyl)methyl]phenol, dilaurylthiodipropionate, and 3,3'-thiodipropionate distearyl. Polymerization inhibitors may be used individually or in combination of two or more.

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

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

<Flame retardant>
There are no particular restrictions on the flame retardants used, but examples include inorganic phosphorus-based flame retardants, organophosphorus-based flame retardants, and halogen-based flame retardants. Flame retardants may be used individually or in combination of two or more types.

The inorganic phosphorus-based flame retardants mentioned above are not particularly limited, but examples include red phosphorus; ammonium phosphates such as monoammonium phosphate, diammonium phosphate, triammonium phosphate, and polyammonium phosphate; and phosphate amides.

The above 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; diphenylphosphine such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and diphenylphosphine oxide; and 10-(2,5-dihydroxyphenyl)-10H-9-oxa Phosphorus-containing phenols such as -10-phosphaphenanthrene-10-oxide, 10-(1,4-dioxynaphthalene)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, diphenylphosphenylhydroquinone, diphenylphosphenyl-1,4-dioxynaphthalene, 1,4-cyclooctylenephosphenyl-1,4-phenyldiol, 1,5-cyclooctylenephosphenyl-1,4-phenyldiol; 9,10-dihydro-9-oxa-10-phos Examples include cyclic phosphorus compounds such as phaphenanthrene-10-oxide, 10-(2,5-dihydrooxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, and 10-(2,7-dihydrooxynaphthyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide; and compounds obtained by reacting the aforementioned phosphate esters, diphenylphosphine, or phosphorus-containing phenols with epoxy resins, aldehyde compounds, or phenolic compounds.

The halogenated flame retardants mentioned above are not particularly limited, but examples 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.

When using a flame retardant, the amount of flame retardant used in the resin composition of this embodiment is preferably 0.1 to 50 parts by mass per 100 parts by mass of the total amount of maleimide resin (A) and resin (B). A flame retardant content of 0.1 parts by mass or more ensures more reliable flame retardancy. On the other hand, a flame retardant content of 50 parts by mass or less allows for flame retardancy while maintaining dielectric properties. From a similar viewpoint, 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 total amount of maleimide resin (A) and resin (B).

<Filler>
Examples of fillers include organic fillers and inorganic fillers. Organic fillers have functions such as improving elongation and improving mechanical strength. Inorganic fillers have functions such as reducing the coefficient of thermal expansion and providing flame retardancy. The above-mentioned fillers may be used individually or in combination of two or more types.

The above-mentioned organic filler is not particularly limited, but examples include polyamide particles.

The inorganic fillers mentioned above are not particularly limited, but examples include 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, and carbon black. Of these, silica is preferred. In this case, amorphous silica, fused silica, crystalline silica, synthetic silica, hollow silica, etc., can be used.

Furthermore, the above-mentioned filler may be surface-treated as needed. While there are no particular limitations on the surface treatment agents that can be used, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, organosilazane compounds, titanate coupling agents, etc., may be used. Specific examples of surface treatment agents include 3-glycidoxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, hexamethyldisilazane, etc. The above-mentioned fillers may be used individually or in combination of two or more types.

When using a filler, the amount of filler used in the resin composition of this embodiment is preferably 0.5 to 95 parts by mass per 100 parts by mass of the total amount of maleimide resin (A) and resin (B). A filler content of 0.5 parts by mass or more allows for sufficient application of the filler's effect. On the other hand, a filler content of 95 parts by mass or less suppresses deterioration of moldability due to increased viscosity of the compound. From a similar viewpoint, the filler content is more preferably 5 parts by mass or more, and even more preferably 80 parts by mass or less, per 100 parts by mass of the total amount of maleimide resin (A) and resin (B).

The method for producing the 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 roller.

[Cured product]
The cured product of this embodiment is a cured product of the resin composition (curable resin composition) described above. In other words, the cured product of this embodiment is obtained by curing the resin composition (curable resin composition) described above by irradiating it with active energy rays. The cured product of this embodiment can function as an insulating material with excellent heat resistance and coating appearance.

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

Specific sources of ultraviolet (UV) light include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, gallium lamps, metal halide lamps, and other UV lamps, as well as sunlight and LEDs. Among these, UV lamps are generally used due to their practicality and economic advantages.

The integrated light intensity 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 integrated light intensity is within the above range, the occurrence of uncured areas can be sufficiently prevented or suppressed. The irradiation of the active energy rays may be performed in one stage or in two or more stages.

Another method for obtaining a cured product by curing a curable resin composition is, for example, heat curing. While the heating temperature during heat curing is not particularly limited, it is preferably between 100 and 300°C, and the heating time is preferably between 1 and 24 hours.

Applications of the curable resin composition or cured product of this embodiment include printed circuit board materials, resin compositions for flexible wiring boards, interlayer insulating materials for build-up substrates, insulating materials for circuit boards such as build-up adhesive films, resin casting materials, adhesives, semiconductor encapsulation materials, semiconductor devices, prepregs, conductive pastes, build-up films, build-up substrates, fiber-reinforced composite materials, and molded products obtained by curing the above composite materials. Among these various applications, in the applications of printed circuit board materials, insulating materials for circuit boards, and build-up adhesive films, it can be used as an insulating material for so-called electronic component-embedded substrates, where passive components such as capacitors and active components such as IC chips are embedded within the substrate. Furthermore, taking advantage of the excellent heat resistance and coating appearance of the cured product, the curable resin composition or cured product of this embodiment can be suitably applied to semiconductor encapsulation materials, semiconductor devices, prepregs, flexible wiring boards, circuit boards, and build-up films, build-up substrates, multilayer printed circuit boards, fiber-reinforced composite materials, and molded products obtained by curing the above composite materials.

[Insulating materials]
The insulating material of this embodiment consists of the resin composition (curable resin composition) described above. Preferably, the insulating material of this embodiment is obtained by curing the resin composition (curable resin composition) described above by irradiation with active energy rays. The insulating material of this embodiment has excellent heat resistance and coating appearance, as well as excellent low dielectric properties and elongation.

Examples of insulating materials include the interlayer insulating material for build-up substrates, insulating materials for circuit boards such as build-up adhesive films, insulating materials for circuit boards, and insulating materials for substrates for embedding electronic components. For example, a method for manufacturing a build-up substrate from the above-mentioned curable resin composition is one that consists of the following three steps. The first step is to apply the curable resin composition, which is appropriately blended with rubber, fillers, etc., to a circuit board with a circuit formed on it using a spray coating method, a curtain coating method, etc., and then cure it. The second step is to then drill holes such as predetermined through-holes as needed, treat the surface with a roughening agent, wash the surface with hot water to form irregularities, and then plate it with a metal such as copper. The third step is to repeat these operations sequentially as desired to alternately build up and form a resin insulating layer and a conductor layer of a predetermined circuit pattern. It is preferable to drill the through-holes after the formation of the outermost resin insulating layer. The first step can be carried out not only by the solution coating method described above, but also by laminating a build-up film that has been pre-coated to a desired thickness and dried. Furthermore, the build-up substrate of the present invention can also be manufactured by forming a roughened surface and eliminating the plating process by heat-pressing a resin-coated copper foil, on which the resin composition has been partially cured, onto a wiring board with a circuit formed on it, at 170-250°C.

[Resist material]
The resist member of this embodiment consists of the resin composition (curable resin composition) described above. The resist member can be obtained, for example, by applying the curable resin composition described above onto a substrate, drying it in a suitable temperature range of 60 to 100°C, exposing it to active energy rays through a photomask on which a desired pattern has been formed, developing the unexposed areas with an alkaline aqueous solution, and further heating and curing it in a temperature range of 140 to 180°C. The resist member (resist film) of this embodiment has excellent heat resistance and coating appearance, as well as excellent low dielectric properties and elongation.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way to the examples described below. In the following, "parts" and "%" refer to mass unless otherwise specified.

The measurement conditions for gel permeation chromatography (GPC), high-performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC-MS), and amine equivalents are as follows:

<Measurement conditions for gel permeation chromatography (GPC)>
Measuring device: Tosoh Corporation "HLC-8320 GPC"
Column: Guard column "HXL-L" manufactured by Tosoh Corporation
+ TSK-GEL G2000HXL manufactured by Tosoh Corporation
+ TSK-GEL G2000HXL manufactured by Tosoh Corporation
+ TSK-GEL G3000HXL manufactured by Tosoh Corporation
+ TSK-GEL G4000HXL manufactured by Tosoh Corporation
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: In accordance with the measurement manual for the "GPC Workstation EcoSEC-WorkStation" mentioned above, the following monodisperse polystyrene with known molecular weight was used.
(Polystyrene used)
"A-500" manufactured by Tosoh Corporation
"A-1000" manufactured by Tosoh Corporation
Tosoh Corporation's "A-2500"
Tosoh Corporation's "A-5000"
"F-1" manufactured by Tosoh Corporation
"F-2" manufactured by Tosoh Corporation
"F-4" manufactured by Tosoh Corporation
Tosoh Corporation's "F-10"
Tosoh Corporation's "F-20"
Tosoh Corporation's "F-40"
Tosoh Corporation's "F-80"
Tosoh Corporation's "F-128"
Sample: A tetrahydrofuran solution containing 1.0% by mass (based on the solid content of the resin) was filtered through a microfilter (50 μl).

<Measurement conditions for high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS)>
Controller: Agilent Technologies 1260 Infinity II
Column: Agilent EC-C18 (4.6 x 50 mm, 2.7 μm)
Column temperature: 40°C
Pump flow rate: 1.0 ml/min Elution conditions: K1-water, K2-acetonitrile
K1/K2 = 0/100 → 30/70 (linear concentration change of 0-1.67 mins)
K1/K2 = 30/70 (1.67 - 5 minutes)
K1/K2 = 30/70 → 90/10 (5-8 minutes)
(Ratios are by volume)
Detection wavelengths: UV 254, 275, 300 nm
MS: Agilent Technologies InfinityLab LC/MSD

<Measurement of amine equivalents>
Approximately 2.5 g of the polyamine compound sample was placed in a 500 mL stoppered Erlenmeyer flask, and 7.5 g of pyridine, 2.5 g of acetic anhydride, and 7.5 g of triphenylphosphine were accurately weighed. A condenser was then attached, and the mixture was heated under reflux in an oil bath set to 120°C for 150 minutes.
After cooling, 5.0 mL of distilled water, 100 mL of propylene glycol monomethyl ether, and 75 mL of tetrahydrofuran were added, and the mixture was titrated with a 0.5 mol/L potassium hydroxide-ethanol solution by potentiometric titration. A blank test was performed in the same manner to correct for the result, and the amine equivalent was measured.
Amine equivalent (g/eq.) = (S × 2,000) / (Blank - A)
S: Amount of sample (g)
A: Consumption volume (mL) of 0.5 mol/L potassium hydroxide-ethanol solution
Blank: Consumption of 0.5 mol/L potassium hydroxide-ethanol solution in the blank test (mL)

Furthermore, the evaluation methods for light sensitivity, developability, heat resistance, and coating appearance are as follows:

<Evaluation of light sensitivity>
The resin compositions obtained in each example and comparative example were applied to a glass substrate to a thickness of 50 μm using an applicator, and then dried at 80°C for 30 minutes. Next, 5 kJ/ ^m² of ultraviolet light was irradiated using a metal halide lamp via a Kodak Step Tablet No. 2. This was then developed in a 1% by mass sodium carbonate aqueous solution (alkaline aqueous solution) for 180 seconds, and evaluated by the number of remaining stages. A higher number of remaining stages indicates higher photosensitivity.

<Evaluation of developability>
The resin compositions obtained in each example and comparative example were applied to a glass substrate to a thickness of 50 μm using an applicator, and then dried at 80°C for 50 minutes, 60 minutes, 70 minutes, 80 minutes, 90 minutes, 100 minutes, and 110 minutes to prepare samples with different drying times. These were developed in a 1% by mass sodium carbonate aqueous solution (alkaline aqueous solution) at 30°C for 180 seconds, and the drying time at 80°C for samples that left no residue on the substrate was evaluated as the drying control range (minutes). A longer drying control range (minutes) indicates higher developability.

<Evaluation of heat resistance>
The resin compositions obtained in each example and comparative example were applied to copper foil (Furukawa Sangyo Co., Ltd., electrolytic copper foil "F2-WS", 18 μm) using an applicator to a thickness of 50 μm, and dried at 80°C for 30 minutes. Next, 10 kJ/ ^m² of ultraviolet light was irradiated 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 the copper foil to obtain a cured product. A 6 mm × 35 mm test piece was cut from this cured product, and the temperature at which the change in elastic modulus was maximized was evaluated as the glass transition temperature (°C) using a viscoelasticity analyzer (DMA: Rheometric Inc. solid viscoelasticity analyzer "RSAII", tensile method: frequency 1 Hz, heating rate 3°C/min). A higher glass transition temperature (°C) indicates superior heat resistance.

<Evaluation of coating film appearance>
The resin compositions obtained in each example and comparative example were applied to a 125 μm PET film (Cosmoshine A4300, manufactured by Toyobo Co., Ltd.) using a bar coater (#12) and dried at 80°C for 5 minutes. Next, a 5 kJ/ ^m² ultraviolet light was irradiated using a metal halide lamp to obtain a cured coating with a thickness of 10 μm. The appearance of this coating was evaluated visually according to the following criteria.
○: No cloudiness ×: Cloudiness present

(Synthesis Example 1: Synthesis of maleimide resin (A-1))
In a 500 mL round-bottom flask attached to a rotary evaporator, 52.40 g (0.43 mol) of 2,6-xylidine, 64.52 g (0.43 mol) of 2,6-diethylaniline, 22.14 g of distilled water, and 22.73 g of p-toluenesulfonic acid were charged and heated to 70°C with stirring. After holding at 70°C for 30 minutes, 34.98 g (0.43 mol) of 37% formalin solution was added in four portions over 1 hour, and the mixture was reacted for 4 hours. After the reaction, the mixture was air-cooled to room temperature, and the reaction solution was transferred to a 2 L separable flask and diluted with 140 g of toluene. The diluted solution was washed once with 100 g of 10% sodium hydroxide aqueous solution and four times with 100 g of distilled water, and concentrated under reduced pressure to obtain 109.48 g of polyamine compound (1). The amine equivalent of polyamine compound (1) was 146 g/eq.

A 2 L flask equipped with a thermometer, condenser, Dean-Stark trap, and stirrer was charged with 78.35 g of polyamine compound (1) (0.54 mol in amine equivalent), 231.5 g of toluene, and 23.3 g of dimethylformamide, and stirred at room temperature. 59.53 g (0.61 mol) of maleic anhydride was added in four portions over 1 hour, and the reaction was continued at room temperature for another hour. 2.3 g of p-toluenesulfonic acid monohydrate was added, the reaction mixture was heated, and the azeotropic water and toluene were cooled and separated under reflux. Only the toluene was returned to the system, and the dehydration reaction was carried out for 6 hours. The solution, cooled to 60°C, was washed twice with 100 g of 5% sodium bicarbonate aqueous solution and seven times with 150 g of distilled water. During this process, 200 g of toluene was added to improve the liquid-liquid separation ability. The solution was concentrated under reduced pressure to obtain 105.7 g of maleimide resin (A-1). LC-MS spectroscopy revealed peaks with M+ = 432, 460, and 488. Each peak corresponds to an ammonia adduct of the compound described below (including maleimide compound (a)). Furthermore, the content of the dinuclear component (bismaleimide compound), calculated from the area ratio in the GPC chart, was 96%. The GPC chart for maleimide resin (A-1) is shown in Figure 1.

(Synthesis Example 2: Synthesis of Maleimide Resin (A-2))
In a 500 mL round-bottom flask attached to a rotary evaporator, 52.11 g (0.43 mol) of 2-ethylaniline, 64.17 g (0.43 mol) of 2,6-diethylaniline, 22.14 g of distilled water, and 22.73 g of p-toluenesulfonic acid were charged and heated to 70°C while stirring. After holding at 70°C for 30 minutes, 34.98 g (0.43 mol) of 37% formalin solution was added in four portions over 1 hour, and the mixture was reacted for 4 hours. After the reaction, the mixture was air-cooled to room temperature, and the reaction solution was transferred to a 2 L separable flask and diluted with 140 g of toluene. The diluted solution was washed once with 100 g of 10% sodium hydroxide aqueous solution and four times with 100 g of distilled water, and concentrated under reduced pressure to obtain 119.02 g of polyamine compound (2). The amine equivalent of polyamine compound (2) was 165 g/eq.

A 2 L flask equipped with a thermometer, condenser, Dean-Stark trap, and stirrer was charged with 87.45 g of polyamine compound (2) (0.53 mol in amine equivalent), 231.5 g of toluene, and 23.3 g of dimethylformamide, and stirred at room temperature. 59.53 g of maleic anhydride (0.61 mol) was added in four portions over 1 hour, and the reaction was continued at room temperature for another hour. 2.3 g of p-toluenesulfonic acid monohydrate was added, the reaction mixture was heated, and the azeotropic water and toluene were cooled and separated under reflux. Only the toluene was returned to the system, and the dehydration reaction was carried out for 6 hours. The solution, cooled to 60°C, was washed twice with 100 g of 5% sodium bicarbonate aqueous solution and seven times with 150 g of distilled water. During this process, 200 g of toluene was added to improve the liquid-liquid separation ability. The solution was concentrated under reduced pressure to obtain 123.36 g of maleimide resin (A-2). LC-MS spectroscopy revealed peaks with M+ = 432, 460, and 488. Each peak corresponds to an ammonia adduct of the compound described below (including maleimide compound (a)). Furthermore, the content of the dinuclear component (bismaleimide compound), calculated from the area ratio in the GPC chart, was 56%. The GPC chart for maleimide resin (A-2) is shown in Figure 2.

(Synthesis Example 3: Synthesis of Maleimide Resin (A-3))
In a 500 mL round-bottom flask attached to a rotary evaporator, 52.11 g (0.43 mol) of 2-ethylaniline, 52.11 g (0.43 mol) of 2,6-xylidine, 22.14 g of distilled water, and 22.73 g of p-toluenesulfonic acid were charged and heated to 70°C with stirring. After holding at 70°C for 30 minutes, 34.98 g (0.43 mol) of 37% formalin solution was added in four portions over 1 hour, and the mixture was reacted for 4 hours. After the reaction, the mixture was air-cooled to room temperature, and the reaction solution was transferred to a 2 L separable flask and diluted with 140 g of toluene. The diluted solution was washed once with 100 g of 10% sodium hydroxide aqueous solution and four times with 100 g of distilled water, and concentrated under reduced pressure to obtain 106.11 g of polyamine compound (3). The amine equivalent of polyamine compound (3) was 147 g/eq.

A 2 L flask equipped with a thermometer, condenser, Dean-Stark trap, and stirrer was charged with 77.91 g of polyamine compound (3) (0.53 mol in amine equivalent), 231.5 g of toluene, and 23.3 g of dimethylformamide, and stirred at room temperature. 59.53 g (0.61 mol) of maleic anhydride was added in four portions over 1 hour, and the reaction was continued at room temperature for another hour. 2.3 g of p-toluenesulfonic acid monohydrate was added, the reaction mixture was heated, and the azeotropic water and toluene were cooled and separated under reflux. Only the toluene was returned to the system, and the dehydration reaction was carried out for 6 hours. The solution, cooled to 60°C, was washed twice with 100 g of 5% sodium bicarbonate aqueous solution and seven times with 150 g of distilled water. During this process, 200 g of toluene was added to improve the liquid-liquid separation ability. The solution was concentrated under reduced pressure to obtain 113.09 g of maleimide resin (A-3). A peak with M+ = 432 was observed in the LC-MS spectrum. This peak corresponds to the ammonia adduct of the following compound (including maleimide compound (a)). Furthermore, the content of the dinuclear component (bismaleimide compound), calculated from the area ratio in the GPC chart, was 58%. The GPC chart for maleimide resin (A-3) is shown in Figure 3.

(Synthesis Examples 4-6: Synthesis of maleimide resins (A-4) to (A-6))
Maleimide resins (A-4) to (A-6) were synthesized using the same procedure as in Example 1, except that the type and amount (moles) of aromatic monoamine compounds were changed as shown in Table 1. The GPC charts for maleimide resins (A-4) to (A-6) are shown in Figures 4 to 6, respectively. The MS spectra of each maleimide resin confirmed that they contained an asymmetric bismaleimide compound (maleimide compound (a)). The content of the dinuclear component (bismaleimide compound) of each maleimide resin, calculated from the area ratio of the GPC chart, is shown in Table 1.

(Synthesis Example 7: Synthesis of a resin (B-1) having acidic groups and polymerizable unsaturated groups)
In a flask equipped with a thermometer, stirrer, and reflux condenser, 123 g of diethylene glycol monoethyl ether acetate was added, and 214 g of orthocresol novolac type epoxy resin "EPICLON N-680" (manufactured by DIC Corporation, softening point 86°C, epoxy equivalent: 214 g/eq) was dissolved. After adding 0.9 g of dibutylhydroxytoluene and 0.2 g of methoquinone, 72 g of acrylic acid and 1.4 g of triphenylphosphine were added, and the reaction was carried out at 120°C for 10 hours while blowing in air. Next, 72 g of diethylene glycol monoethyl ether acetate and 76 g of tetrahydrophthalic anhydride were added, and the reaction was carried out at 110°C for 3 hours to obtain a resin (B-1) having acidic groups and polymerizable unsaturated groups. The nonvolatile content of this resin (B-1) having acidic groups and polymerizable unsaturated groups was 65% by mass, and the solid content acid value was 80 mg KOH/g. The acid value was measured based on the neutralization titration method specified in JIS K 0070 (1992).

(Synthesis Example 8: Synthesis of a resin (B-2) having acidic groups and polymerizable unsaturated groups)
In a flask equipped with a thermometer, stirrer, and reflux condenser, 499.7 g of diethylene glycol monoethyl ether acetate was placed, and 244.3 g of isocyanurate-modified isophorone diisocyanate (VESTANAT T-1890/100, manufactured by EVONIK, NCO% = 17.2%) and 192.0 g of trimellitic anhydride were dissolved. Then, 1.0 g of dibutylhydroxytoluene was added. The mixture was reacted at 160°C for 6 hours under a nitrogen atmosphere, and it was confirmed that the NCO% was 0.1 or less. Next, 0.4 g of methoquinone was added as a thermal polymerization inhibitor, followed by 147.6 g of pentaerythritol polyacrylate mixture (Aronics M-306, manufactured by Toagosei Co., Ltd., hydroxyl value: 159.7 mg KOH/g) and 3.5 g of triphenylphosphine. The mixture was reacted at 110°C for 5 hours while blowing air into the mixture. Subsequently, 165.0 g of glycidyl methacrylate was added and the mixture was reacted at 110°C for 6 hours. Next, 110.4 g of succinic anhydride was added and the mixture was reacted at 110°C for 5 hours to obtain a resin (B-2) having acidic groups and polymerizable unsaturated groups. The non-volatile content of this resin (B-2) was 62% by mass, and the solids acid value was 80 mg KOH/g.

(Examples 1-12: Preparation of resin compositions (1)-(12))
A maleimide resin (A) obtained in the above synthesis example and a resin (B) having acidic groups and polymerizable unsaturated groups obtained in the above synthesis example were mixed in the composition ratios shown in Table 2 to obtain resin compositions (1) to (12), respectively. To this resin composition, orthocresol novolac type epoxy resin (DIC Corporation's "EPICLON N-680", epoxy equivalent: 214 g/eq) as a curing agent, diethylene glycol monoethyl ether acetate as an organic solvent, photopolymerization initiator (IGM Resins'"Omnirad907"), 2-ethyl-4-methylimidazole as a curing accelerator, dipentaerythritol hexaacrylate as a compound having polymerizable unsaturated groups, and phthalocyanine green as a pigment were mixed in the composition ratios shown in Table 2 to obtain resin compositions (1) to (12), respectively. The photosensitivity and developability of the obtained resin compositions (1) to (12) were evaluated. The results are shown in Table 2.

(Comparative Example 1: Preparation of resin composition (C1))
Resin composition (C1) was obtained by mixing in the same manner as in Example 1 above, except that 4,4'-diphenylmethanebismaleimide (BMI-1000, manufactured by Yamato Chemical Industries, Ltd.) was used instead of the maleimide resin (A) obtained in the above synthesis example, in the composition ratio shown in Table 2. Note that 4,4'-diphenylmethanebismaleimide is a maleimide compound having two identical aromatic ring-maleimide skeletons. The obtained resin composition (C1) was evaluated for photosensitivity and developability. The results are shown in Table 2.

(Examples 13-24: Preparation of resin compositions (13)-(24))
The maleimide resin (A) obtained in the above synthesis example and the resin (B) having acidic groups and polymerizable unsaturated groups obtained in the above synthesis example were mixed in the composition ratios shown in Table 3 to obtain a resin composition. To this resin composition, an orthocresol novolac type epoxy resin (DIC Corporation's "EPICLON N-680", epoxy equivalent: 214 g/eq), diethylene glycol monoethyl ether acetate as an organic solvent, and a photopolymerization initiator (IGM Resins'"Omnirad907") were mixed in the composition ratios shown in Table 3 to obtain resin compositions (13) to (24), respectively. The heat resistance and coating film appearance of the obtained resin compositions (13) to (24) were evaluated. The results are shown in Table 3.

(Comparative Example 2: Preparation of resin composition (C2))
Except for using 4,4'-diphenylmethanebismaleimide (BMI-1000, manufactured by Yamato Chemical Industries, Ltd.) instead of the maleimide resin (A) obtained in the above synthesis example, resin composition (C2) was obtained by mixing in the composition ratio shown in Table 3 in the same manner as in Example 13 above. The heat resistance and coating film appearance of the obtained resin composition (C2) were evaluated. The results are shown in Table 3.

Tables 2 and 3 show that the resin compositions of the examples exhibit higher photosensitivity and developability compared to the comparative examples, and that the resulting cured product (cured coating) exhibits excellent heat resistance and coating appearance.

According to the present invention, it is possible to provide a resin composition that exhibits high photosensitivity and developability, and that can produce excellent heat resistance and coating appearance in the resulting cured product (cured coating film). Furthermore, according to the present invention, it is possible to provide cured products, insulating materials, and resist members that can be obtained using the resin composition.

Claims (7)

A resin composition comprising a maleimide resin (A) and a resin (B) having acidic groups and polymerizable unsaturated groups,
The maleimide resin (A) contains the following general formula (1) in one molecule:
The first aromatic ring-maleimide skeleton shown by and the following general formula (2):
A resin composition comprising a maleimide compound (a) having a second aromatic ring-maleimide skeleton represented by [wherein formulas (1) and (2), ^R1 to ^R4 each independently represent hydrogen, a methyl group, or an ethyl group, ^Ar1 and ^Ar2 each independently represent an aromatic ring having one or more substituents, the substituents being aliphatic hydrocarbon groups having 1 to 4 carbon atoms, and * represents a bond from the aromatic ring to another site, provided that ^Ar1 and ^Ar2 differ from each other in at least one of the type of substituent , the number of substituents , and the position of the substituents ]. The resin composition according to claim 1, wherein the maleimide compound (a) is an asymmetric bismaleimide compound in which the first aromatic ring-maleimide skeleton and the second aromatic ring-maleimide skeleton are bonded via an organic group having 1 to 200 carbon atoms. The resin composition according to claim 1 or 2, wherein the mass ratio of the solid content of the maleimide resin (A) and the resin having the acid group and polymerizable unsaturated group (B) [(A)/(B)] is in the range of 1/100 to 100/100. The resin composition according to any one of claims 1 to 3, further comprising a photopolymerization initiator. A cured product of the resin composition described in claim 4. An insulating material characterized by comprising the resin composition described in claim 4. A resist member characterized by comprising the resin composition described in claim 4.