JP2021167905A - Photosensitive composition, patterned cured film production method, and patterned cured film - Google Patents

Abstract

To provide: a photosensitive composition capable of forming a cured product patterned well and having a low dielectric constant; a cured product of the photosensitive composition; and a method of producing a cured product using the photosensitive composition.SOLUTION: A photosensitive composition comprises an alkali-soluble resin (A), a photopolymerizable compound (B), and a photoinitiator (C). A polyfunctional compound with 3 or 4 (meth)acryloyl groups is used as the photopolymerizable compound (B). An oxime ester compound with a specific structure is used as the photoinitiator (C).SELECTED DRAWING: None

Description

The present invention relates to a photosensitive composition, a cured product of the photosensitive composition, and a method for producing a cured product using the photosensitive composition.

In a display device such as a liquid crystal display device, a material such as an insulating film needs to efficiently transmit light emitted from a light source such as a backlight. Therefore, in order to form an insulating film, a material capable of forming a film having excellent transparency is required.

Such a transparent insulating film is usually patterned on the substrate. As a method for forming a patterned transparent insulating film, for example, a negative photosensitive resin containing an alkali-soluble resin having an oxetane ring, a polymerizable polyfunctional compound, and an α-aminoalkylphenone-based photopolymerization initiator is included. A method using a composition (see Patent Document 1) is known.

By the way, in recent years, the production volume of color filters has also increased in line with the increase in the production volume of liquid crystal display, and from the viewpoint of further improving productivity, the pattern can be formed with a low exposure amount. There is a demand for sensitive photosensitive compositions.
However, where various functional films contained in the color filter contain a colorant, when the photosensitive composition contains a colorant, the α-aminoalkylphenone-based photopolymerization described in Patent Document 1 is initiated. There is a problem that it is difficult to obtain sufficiently high sensitivity when an agent is used.
Under such circumstances, the applicant has proposed as a highly sensitive photosensitive composition a highly sensitive photosensitive composition containing an oxime ester compound having a specific structure as a photopolymerization initiator (Patent Document 2). And 3).

Japanese Unexamined Patent Publication No. 2012-173678 Japanese Unexamined Patent Publication No. 2012-189996 Japanese Unexamined Patent Publication No. 2012-18997

However, in a photosensitive composition containing an oxime ester compound as a photopolymerization initiator, while the sensitivity is good, it is difficult to form a cured product having a low relative permittivity, or a well-patterned cured product is formed. There is a problem that it is difficult.

The present invention has been made in view of the above problems, and is a photosensitive composition having a low relative permittivity and capable of forming a well-patterned cured product, a cured product of the photosensitive composition, and the photosensitive composition. It is an object of the present invention to provide a method for producing a cured product using a sex composition.

In a photosensitive composition containing an alkali-soluble resin (A), a photopolymerizable compound (B), and a photopolymerization initiator (C), the present inventors have 3 or 3 as the photopolymerizable compound (B). We have found that the above problems can be solved by using a polyfunctional compound having 4 (meth) acryloyl groups and an oxime ester compound having a specific structure as a photopolymerization initiator (C), and to complete the present invention. I arrived. More specifically, the present invention provides the following.

（式（１）中、Ｒ^ｃ１は水素原子、ニトロ基又は１価の有機基であり、Ｒ^ｃ２及びＲ^ｃ３は、それぞれ、置換基を有してもよい鎖状アルキル基、置換基を有してもよい環状有機基、又は水素原子であり、Ｒ^ｃ２とＲ^ｃ３とは相互に結合して環を形成してもよく、Ｒ^ｃ４は１価の有機基であり、Ｒ^ｃ５は、水素原子、置換基を有してもよい炭素原子数１以上１１以下のアルキル基、又は置換基を有してもよいアリール基であり、ｎ１は０以上４以下の整数であり、ｎ２は０又は１である。） The first aspect of the present invention comprises an alkali-soluble resin (A), a photopolymerizable compound (B), and a photopolymerization initiator (C).
The photopolymerizable compound (B) comprises a polyfunctional compound having 3 or 4 (meth) acryloyl groups.
The photopolymerization initiator (C) is a photosensitive composition containing a compound represented by the following formula (1).

(In the formula (1), R ^c1 is a hydrogen atom, a nitro group or a monovalent organic group, and R ^c2 and R ^c3 each have a chain alkyl group and a substituent which may have a substituent. It may be a cyclic organic group or a hydrogen atom, and R ^c2 and R ^c3 may be bonded to each other to form a ring, R ^c4 is a monovalent organic group, and R ^c5 is hydrogen. An atom, an alkyl group having 1 or more and 11 or less carbon atoms which may have a substituent, or an aryl group which may have a substituent, n1 is an integer of 0 or more and 4 or less, and n2 is 0 or It is 1.)

A second aspect of the present invention is a cured product of the photosensitive composition according to the first aspect.

A third aspect of the present invention is to mold the photosensitive composition according to the first aspect according to the shape of the cured product to be formed.
Exposure to the molded photosensitive composition and
A method for producing a cured product including.

According to the present invention, a photosensitive composition having a low relative permittivity and capable of forming a well-patterned cured product, a cured product of the photosensitive composition, and a method for producing a cured product using the photosensitive composition. And can be provided.

≪Photosensitive composition≫
The photosensitive composition contains an alkali-soluble resin (A), a photopolymerizable compound (B), and a photopolymerization initiator (C). The photopolymerizable compound (B) comprises a polyfunctional compound having 3 or 4 (meth) acryloyl groups. Further, the photopolymerization initiator (C) contains an oxime ester compound represented by the following formula (1). By incorporating the above-mentioned photopolymerizable compound (B) and the photopolymerization initiator (C) in combination in the photosensitive composition, a cured product having a low relative permittivity and well-patterned can be formed.

（式（１）中、Ｒ^ｃ１は、各々独立に、水素原子、ニトロ基、又は１価の有機基であり、Ｒ^ｃ２及びＲ^ｃ３は、それぞれ、置換基を有してもよい鎖状アルキル基、置換基を有してもよい鎖状アルコキシ基、置換基を有してもよい環状有機基、又は水素原子であり、Ｒ^ｃ２とＲ^ｃ３とは相互に結合して環を形成してもよく、Ｒ^ｃ４は１価の有機基であり、Ｒ^ｃ５は、水素原子、置換基を有してもよい炭素原子数１以上２０以下の脂肪族炭化水素基、又は置換基を有してもよいアリール基であり、ｎ１は０以上４以下の整数であり、ｎ２は０又は１である。）

(In the formula (1), R ^c1 is independently a hydrogen atom, a nitro group, or a monovalent organic group, and R ^c2 and R ^c3 are chain alkyls which may each have a substituent. It is a group, a chain alkoxy group which may have a substituent, a cyclic organic group which may have a substituent, or a hydrogen atom, and R ^c2 and R ^c3 are bonded to each other to form a ring. R ^c4 is a monovalent organic group, and R ^c5 has a hydrogen atom, an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, or a substituent. It is also a good aryl group, n1 is an integer of 0 or more and 4 or less, and n2 is 0 or 1.)

Hereinafter, essential or arbitrary components contained in the photosensitive composition and a method for producing the photosensitive composition will be described in order.

<Alkali-soluble resin (A)>
The photosensitive composition contains an alkali-soluble resin (A). The alkali-soluble resin (A) is not particularly limited, and can be appropriately selected from the alkali-soluble resins conventionally blended in various photosensitive compositions.
Here, in the present specification, the alkali-soluble resin (A) refers to a resin having a functional group (for example, a phenolic hydroxyl group, a carboxy group, a sulfonic acid group, etc.) having alkali solubility in the molecule.

Examples of the resin suitable as the alkali-soluble resin (A) include resins (a-I) having a cardo structure (hereinafter, also referred to as "cardo resin (a-I)").
When a resin (a-I) having a cardo structure is used as the alkali-soluble resin, it is easy to obtain a photosensitive composition having excellent resolution, and the photosensitive composition is used to form a cured film that does not easily flow excessively by heating. Cheap. Therefore, it is easy to form a cured film having a good shape.

[Resin having a cardo structure (a-I)]
As the resin (a-I) having a cardo skeleton, a resin having a cardo skeleton in its structure and having a predetermined alkali solubility can be used. The cardo skeleton is a skeleton in which a second cyclic structure and a third cyclic structure are bonded to one ring carbon atom constituting the first cyclic structure. The second annular structure and the third annular structure may have the same structure or different structures.
A typical example of a cardo skeleton is a skeleton in which two aromatic rings (for example, a benzene ring) are bonded to a carbon atom at the 9-position of the fluorene ring.

The cardo resin (a-I) is not particularly limited, and conventionally known resins can be used. Among them, the resin represented by the following formula (a-1) is preferable.

In the formula (a-1), X ^a represents a group represented by the following formula (a-2). m1 represents an integer of 0 or more and 20 or less.

In the above formula (a-2), R ^a1 independently represents a hydrogen atom, a hydrocarbon group having 1 or more and 6 or less carbon atoms, or a halogen atom, and R ^a2 independently represents a hydrogen atom or a methyl group. ^{shown, R a3} each independently represent an alkylene group of straight or branched chain, m2 represents 0 or 1, ^{W a} represents a group represented by the following formula (a3).

In the formula (a-2), ^{as Ra3} , an alkylene group having 1 or more and 20 or less carbon atoms is preferable, an alkylene group having 1 or more and 10 or less carbon atoms is more preferable, and an alkylene group having 1 or more and 6 or less carbon atoms is preferable. Is particularly preferable, and ethane-1,2-diyl group, propane-1,2-diyl group, and propane1,3-diyl group are most preferable.

Ring A in formula (a-3) represents an aliphatic ring that may be condensed with an aromatic ring or may have a substituent. The aliphatic ring may be an aliphatic hydrocarbon ring or an aliphatic heterocycle.
Examples of the aliphatic ring include monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane and the like.
Specific examples thereof include monocycloalkanes such as cyclopentane, cyclohexane, cycloheptane and cyclooctane, and adamantane, norbornane, isobornane, tricyclodecane and tetracyclododecane.
The aromatic ring that may be condensed with the aliphatic ring may be an aromatic hydrocarbon ring or an aromatic heterocycle, and an aromatic hydrocarbon ring is preferable. Specifically, a benzene ring and a naphthalene ring are preferable.

Preferable examples of the divalent group represented by the formula (a-3) include the following groups.

^{The divalent group X a} in the formula (a-1) is a cardo by reacting a tetracarboxylic dianhydride giving the residue Z ^a with a diol compound represented by the following formula (a-2a). It is introduced into the resin (a-I).

In the formula (a-2a), R ^a1 , R ^a2 , R ^a3 , and m2 are as described in the formula (a-2). The ring A in the formula (a-2a) is as described in the formula (a-3).

The diol compound represented by the formula (a-2a) can be produced, for example, by the following method.
First, the hydrogen atom in the phenolic hydroxyl group of the diol compound represented by the following formula (a-2b) is replaced with a group represented by ^{−R a3 −OH according to a conventional method, if necessary.} Glysidylation is performed using epichlorohydrin or the like to obtain an epoxy compound represented by the following formula (a-2c).
Then, the epoxy compound represented by the formula (a-2c) is reacted with acrylic acid or methacrylic acid to obtain a diol compound represented by the formula (a-2a).
In the formulas (a-2b) and (a-2c), ^Ra1 , ^Ra3 , and m2 are as described in the formula (a-2). The ring A in the formula (a-2b) and the formula (a-2c) is as described in the formula (a-3).
The method for producing the diol compound represented by the formula (a-2a) is not limited to the above method.

Preferable examples of the diol compound represented by the formula (a-2b) include the following diol compounds.

In the formula ^{(a-1), R a0} is a group represented by hydrogen or a ^-CO-Y a -COOH. Here, ^{Y a} represents the residue obtained by removing dicarboxylic acid anhydride from the acid anhydride group (-CO-O-CO-). Examples of dicarboxylic acid anhydrides are phthalic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, chlorendic anhydride, methyltetrahydro. Examples thereof include phthalic anhydride and glutaric anhydride.

Further, in the above formula ^(a-1), Z a represents a residue obtained by removing two acid anhydride groups from a tetracarboxylic acid dianhydride. Examples of tetracarboxylic acid dianhydrides include tetracarboxylic acid dianhydride represented by the following formula (a-4), pyromellitic acid dianhydride, benzophenone tetracarboxylic acid dianhydride, and biphenyltetracarboxylic acid dianhydride. Examples thereof include biphenyl ether tetracarboxylic acid dianhydride.
Further, in the above equation (a-1), m represents an integer of 0 or more and 20 or less.

（式（ａ−４）中、Ｒ^ａ４、Ｒ^ａ５、及びＲ^ａ６は、それぞれ独立に、水素原子、炭素原子数１以上１０以下のアルキル基及びフッ素原子からなる群より選択される１種を示し、ｍ３は、０以上１２以下の整数を示す。）

(In the formula (a-4), R ^a4 , R ^a5 , and R ^a6 are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, and a fluorine atom. Indicated, m3 indicates an integer of 0 or more and 12 or less.)

^{The alkyl group that can be selected as Ra4} in the formula (a-4) is an alkyl group having 1 or more and 10 or less carbon atoms. By setting the number of carbon atoms contained in the alkyl group in this range, the heat resistance of the obtained carboxylic acid ester can be further improved. When R ^a4 is an alkyl group, the number of carbon atoms thereof is preferably 1 or more and 6 or less, more preferably 1 or more and 5 or less, and further preferably 1 or more and 4 or less, from the viewpoint that a cardo resin having excellent heat resistance can be easily obtained. 1 or more and 3 or less are particularly preferable.
When R ^a4 is an alkyl group, the alkyl group may be linear or branched.

^{As R a4} in the formula (a-4), a hydrogen atom or an alkyl group having 1 or more and 10 or less carbon atoms is more preferable independently from the viewpoint that a cardo resin having excellent heat resistance can be easily obtained. ^{R a4} in the formula (a-4) is more preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group or an isopropyl group, and particularly preferably a hydrogen atom or a methyl group.
^{The plurality of Ra4s} in the formula (a-4) are preferably the same group because it is easy to prepare a high-purity tetracarboxylic dianhydride.

M3 in the formula (a-4) represents an integer of 0 or more and 12 or less. Purification of the tetracarboxylic dianhydride can be facilitated by setting the value of m3 to 12 or less.
The upper limit of m3 is preferably 5 and more preferably 3 because the tetracarboxylic dianhydride can be easily purified.
From the viewpoint of the chemical stability of the tetracarboxylic dianhydride, the lower limit of m3 is preferably 1 and more preferably 2.
The m3 in the formula (a-4) is particularly preferably 2 or 3.

The alkyl groups having 1 or more and 10 or less carbon atoms that can be selected as ^{R a5} and R ^a6 in the formula (a-4) are the same as the alkyl groups having 1 or more and 10 or less carbon atoms that can be selected as ^{R a4.} ..
R ^a5 and R ^a6 have a hydrogen atom or a carbon atom number of 1 or more and 10 or less (preferably 1 or more and 6 or less, more preferably 1 or more and 5 or less, because the tetracarboxylic acid dianhydride can be easily purified. More preferably, it is 1 or more and 4 or less, particularly preferably 1 or more and 3 or less), and it is particularly preferable that it is a hydrogen atom or a methyl group.

Examples of the tetracarboxylic acid dianhydride represented by the formula (a-4) include norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'', 6,6''-Tetracarboxylic acid dianhydride (also known as "norbornane-2-spir-2'-cyclopentanone-5'-spiro-2"-norbornane-5,5'', 6,6'' -Tetracarboxylic acid dianhydride "), methylnorbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-(methylnorbornane) -5,5", 6,6 "-tetra Norbornane dianhydride, norbornane-2-spiro-α-cyclohexanone-α'-spiro-2''-norbornane-5,5'', 6,6''-tetracarboxylic acid dianhydride (also known as "norbornane-" 2-Spiro-2'-Cyclohexanone-6'-Spiro-2 "-norbornane-5,5", 6,6 "-tetracarboxylic acid dianhydride"), methylnorbornane-2-spiro-α- Cyclohexanone-α'-spiro-2''- (methylnorbornane) -5,5'', 6,6''-tetracarboxylic acid dianhydride, norbornane-2-spiro-α-cyclopropanol-α'- Spiro-2''-norbornane-5,5'', 6,6''-tetracarboxylic acid dianhydride, norbornane-2-spiro-α-cyclobutanone-α'-spiro-2''-norbornane-5, 5'', 6,6''-tetracarboxylic acid dianhydride, norbornane-2-spiro-α-cycloheptanone-α'-spiro-2''-norbornane-5,5'', 6,6' '-Tetracarboxylic dianhydride, norbornane-2-spiro-α-cyclooctanone-α'-spiro-2''-norbornane-5,5'', 6,6''-tetracarboxylic acid dianhydride , Norbornane-2-spiro-α-cyclononanonone-α'-spiro-2''-norbornane-5,5'', 6,6''-tetracarboxylic acid dianhydride, norbornane-2-spiro-α-cyclodecanone -Α'-Spiro-2''-norbornane-5,5'', 6,6''-tetracarboxylic acid dianhydride, norbornane-2-spiro-α-cycloundecanone-α'-spiro-2' '-Norbornane-5,5'', 6,6''-Tetracarboxylic acid dianhydride, Norbornane-2-spiro-α-cyclododecanone-α'-Spyro-2''-norbornane-5,5' ', 6, 6''-Tetracarboxylic acid dianhydride, Norbornane Nan-2-spiro-α-cyclotridecanone-α'-spiro-2''-norbornane-5,5'', 6,6''-tetracarboxylic acid dianhydride, norbornane-2-spiro-α- Cyclotetradecanone-α'-spiro-2''-norbornane-5,5'', 6,6''-tetracarboxylic acid dianhydride, norbornane-2-spiro-α-cyclopentadecanone-α' -Spiro-2 "-norbornane-5,5", 6,6 "-tetracarboxylic acid dianhydride, norbornane-2-spiro-α- (methylcyclopentanone) -α'-spiro-2' '-Norbornane-5,5'', 6,6''-Tetracarboxylic acid dianhydride, Norbornane-2-spiro-α- (methylcyclohexanone) -α'-Spiro-2''-norbornane-5,5 '', 6,6''-Tetracarboxylic acid dianhydride and the like can be mentioned.

The weight average molecular weight of the cardo resin (a-I) is preferably 1000 or more and 40,000 or less, more preferably 1500 or more and 30,000 or less, and further preferably 2000 or more and 10000 or less. Within the above range, sufficient heat resistance and mechanical strength can be obtained for the cured film formed by using the photosensitive composition while obtaining good developability.

[Novolak resin (a-II)]
It is also preferable that the alkali-soluble resin (A) contains the novolak resin (a-II) from the viewpoint that a cured product that does not easily flow excessively by heating is easily formed.
As the novolak resin (a-II), various novolak resins conventionally blended in the photosensitive composition can be used. The novolak resin (a-II) is preferably one obtained by addition-condensing an aromatic compound having a phenolic hydroxyl group (hereinafter, simply referred to as "phenols") and aldehydes under an acid catalyst.

(Phenols)
Examples of the phenols used in producing the novolak resin (a-II) include phenols; cresols such as o-cresol, m-cresol, and p-cresol; 2,3-xylenol, and 2,4-xylenol. , 2,5-Xylenol, 2,6-Xylenol, 3,4-Xylenol, 3,5-Xylenol and other xylenols; o-ethylphenol, m-ethylphenol, p-ethylphenol and other ethylphenols; 2 Alkylphenols such as -isopropylphenol, 3-isopropylphenol, 4-isopropylphenol, o-butylphenol, m-butylphenol, p-butylphenol, and p-tert-butylphenol; 2,3,5-trimethylphenol, and 3,4 , 5-Trialkylphenols such as trimethylphenol; polyhydric phenols such as resorcinol, catechol, hydroquinone, hydroquinone monomethyl ether, pyrogallol, and fluoroglycinol; alkyl polyhydric phenols such as alkylresorcin, alkylcatechol, and alkylhydroquinone. (Each alkyl group has 1 or more and 4 or less carbon atoms.); Α-naphthol; β-naphthol; hydroxydiphenyl; and bisphenol A and the like. These phenols may be used alone or in combination of two or more.

Among these phenols, m-cresol and p-cresol are preferable, and it is more preferable to use m-cresol and p-cresol in combination. In this case, various properties such as heat resistance of the cured film formed by using the photosensitive composition can be adjusted by adjusting the blending ratio of both.
The blending ratio of m-cresol and p-cresol is not particularly limited, but the molar ratio of m-cresol / p-cresol is preferably 3/7 or more and 8/2 or less. By using m-cresol and p-cresol in a ratio within such a range, it is easy to obtain a photosensitive composition capable of forming a cured film having excellent heat resistance.

A novolak resin produced by using m-cresol and 2,3,5-trimethylphenol in combination is also preferable. When such a novolak resin is used, it is particularly easy to obtain a photosensitive composition capable of forming a cured film having excellent heat resistance.
The mixing ratio of m-cresol and 2,3,5-trimethylphenol is not particularly limited, but the molar ratio of m-cresol / 2,3,5-trimethylphenol is 70/30 or more and 95/5 or less. Is preferable.

(Aldehydes)
Examples of aldehydes used in producing the novolak resin (a-II) include formaldehyde, paraformaldehyde, furfural, benzaldehyde, nitrobenzaldehyde, and acetaldehyde. These aldehydes may be used alone or in combination of two or more.

(Acid catalyst)
Acid catalysts used in the preparation of novolak resin (a-II) include, for example, inorganic acids such as hydrochloric acid, sulfuric acid, nitrate, phosphoric acid, and phosphoric acid; formic acid, oxalic acid, acetic acid, diethylsulfate, and Examples include organic acids such as paratoluene sulfonic acid; and metal salts such as zinc acetate. These acid catalysts may be used alone or in combination of two or more.

(Molecular weight)
The polystyrene-equivalent weight average molecular weight (Mw; hereinafter, also simply referred to as “weight average molecular weight”) of the novolak resin (a-II) is determined from the viewpoint of the heat resistance of the cured film formed by using the photosensitive composition. The lower limit is 2000, more preferably 5000, particularly preferably 10000, further preferably 15,000, most preferably 20000, the upper limit is 50,000, more preferably 45,000, even more preferably 40,000, and most preferably 35,000.

As the novolak resin (a-II), at least two types having different polystyrene-equivalent weight average molecular weights can be used in combination. By using a combination of large and small materials having different weight average molecular weights, it is possible to balance the developability of the photosensitive composition and the heat resistance of the cured film formed by using the photosensitive composition.

[Modified epoxy resin (a-III)]
The alkali-soluble resin (A) is a polybasic anhydride (a-3c) adduct (a-3) of a reaction product of an epoxy compound (a-3a) and an unsaturated group-containing carboxylic acid (a-3b). May include. Such an adduct is also referred to as "modified epoxy resin (a-III)".
In the specification of the present application and claims, a compound that falls under the above definition and does not fall under the above-mentioned resin (a-I) having a cardo structure is a modified epoxy resin (a-III). ).

Hereinafter, the epoxy compound (a-3a), the unsaturated group-containing carboxylic acid (a-3b), and the polybasic acid anhydride (a-3c) will be described.

<Epoxy compound (a-3a)>
The epoxy compound (a-3a) is not particularly limited as long as it is a compound having an epoxy group, and may be an aromatic epoxy compound having an aromatic group or an aliphatic epoxy compound containing no aromatic group. Often, aromatic epoxy compounds having an aromatic group are preferred.
The epoxy compound (a-3a) may be a monofunctional epoxy compound or a bifunctional or higher functional epoxy compound, and a polyfunctional epoxy compound is preferable.

Specific examples of the epoxy compound (a-3a) include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AD type epoxy resin, naphthalene type epoxy resin, and biphenyl type epoxy resin. Functional epoxy resin; glycidyl ester type epoxy resin such as dimer acid glycidyl ester and triglycidyl ester; tetraglycidyl aminodiphenylmethane, triglycidyl-p-aminophenol, tetraglycidyl metaxylylene diamine, tetraglycidyl bisaminomethylcyclohexane and the like. Glycidylamine type epoxy resin; heterocyclic epoxy resin such as triglycidyl isocyanurate; fluoroglycinol triglycidyl ether, trihydroxybiphenyl triglycidyl ether, trihydroxyphenylmethane triglycidyl ether, glycerin triglycidyl ether, 2- [4- (2,3-Epoxy propoxy) phenyl] -2- [4- [1,1-bis [4- (2,3-epoxy propoxy) phenyl] ethyl] phenyl] propane, and 1,3-bis [4- [1- [4- (2,3-epoxypropoxy) phenyl] -1- [4- [1- [4- (2,3-epoxypropoxy) phenyl] -1-methylethyl] phenyl] ethyl] phenoxy] Trifunctional epoxy resins such as -2-propanol; tetrafunctional epoxy resins such as tetrahydroxyphenylethane tetraglycidyl ether, tetraglycidyl benzophenone, bisresorcinol tetraglycidyl ether, and tetraglycidoxybiphenyl can be mentioned.

Further, as the epoxy compound (a-3a), an epoxy compound having a biphenyl skeleton is preferable.
The epoxy compound having a biphenyl skeleton preferably has at least one biphenyl skeleton represented by the following formula (a-3a-1) in the main chain.
The epoxy compound having a biphenyl skeleton is preferably a polyfunctional epoxy compound having two or more epoxy groups.
By using an epoxy compound having a biphenyl skeleton, it is easy to obtain a photosensitive composition capable of forming a cured film having an excellent balance between sensitivity and developability and excellent adhesion to a substrate.

（式（ａ−３ａ−１）中、Ｒ^ａ７は、それぞれ独立に、水素原子、炭素原子数１以上１２以下のアルキル基、ハロゲン原子、又は置換基を有してもよいフェニル基であり、ｊは１以上４以下の整数である。）

(In the formula (a-3a-1), R ^a7 is a phenyl group which may independently have a hydrogen atom, an alkyl group having 1 or more and 12 or less carbon atoms, a halogen atom, or a substituent. j is an integer of 1 or more and 4 or less.)

When R ^a7 is an alkyl group having 1 or more carbon atoms and 12 or less carbon atoms, specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and sec-butyl. Group, tert-butyl group, n-pentyl group, isopentyl group, sec-pentyl group, tert-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, isooctyl group, sec-octyl group, tert- Examples thereof include an octyl group, an n-nonyl group, an isononyl group, an n-decyl group, an isodecyl group, an n-undecyl group, and an n-dodecyl group.

When R ^a7 is a halogen atom, specific examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

When R ^a7 is a phenyl group which may have a substituent, the number of substituents on the phenyl group is not particularly limited. The number of substituents on the phenyl group is 0 or more and 5 or less, preferably 0 or 1.
Examples of substituents are an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an aliphatic acyl group having 2 to 4 carbon atoms, a halogen atom, a cyano group, and a nitro group. The group is mentioned.

（式（ａ−３ａ−２）中、Ｒ^ａ７及びｊは、式（ａ−３ａ−１）と同様であり、ｋは括弧内の構成単位の平均繰り返し数であって０以上１０以下である。） The epoxy compound (a-3a) having a biphenyl skeleton represented by the above formula (a-3a-1) is not particularly limited, and examples thereof include an epoxy compound represented by the following formula (a-3a-2). be able to.

(In the formula (a-3a-2), R ^a7 and j are the same as those in the formula (a-3a-1), and k is the average number of repetitions of the constituent units in parentheses and is 0 or more and 10 or less. .)

（式（ａ−３ａ−３）中、ｋは、式（ａ−３ａ−２）と同様である。） Among the epoxy compounds represented by the formula (a-3a-2), it is particularly easy to obtain a photosensitive composition having an excellent balance between sensitivity and developability, and therefore, it is represented by the following formula (a-3a-3). Compounds are preferred.

(In the formula (a-3a-3), k is the same as the formula (a-3a-2).)

(Unsaturated group-containing carboxylic acid (a-3b))
In preparing the modified epoxy compound (a-3), the epoxy compound (a-3a) is reacted with an unsaturated group-containing carboxylic acid (a-3b).
As the unsaturated group-containing carboxylic acid (a-3b), a monocarboxylic acid containing a reactive unsaturated double bond such as an acrylic group or a methacryl group in the molecule is preferable. Examples of such unsaturated group-containing carboxylic acids include acrylic acid, methacrylic acid, β-styrylacrylic acid, β-flufurylacrylic acid, α-cyanocinnamic acid, and cinnamic acid. Further, the unsaturated group-containing carboxylic acid (a-3b) may be used alone or in combination of two or more.

The epoxy compound (a-3a) and the unsaturated group-containing carboxylic acid (a-3b) can be reacted by a known method. As a preferable reaction method, for example, the epoxy compound (a-3a) and the unsaturated group-containing carboxylic acid (a-3b) are mixed with a tertiary amine such as triethylamine or benzylethylamine, dodecyltrimethylammonium chloride, tetramethylammonium chloride, or the like. Using a quaternary ammonium salt such as tetraethylammonium chloride or benzyltriethylammonium chloride, pyridine, or triphenylphosphine as a catalyst, the reaction is carried out in an organic solvent at a reaction temperature of 50 ° C. or higher and 150 ° C. or higher for several hours or more and several tens of hours or less. The method can be mentioned.

The ratio of the amounts used in the reaction of the epoxy compound (a-3a) and the unsaturated group-containing carboxylic acid (a-3b) is the epoxy equivalent of the epoxy compound (a-3a) and the unsaturated group-containing carboxylic acid (a-3b). The ratio of a-3b) to the carboxylic acid equivalent is usually preferably 1: 0.5 to 1: 2, more preferably 1: 0.8 to 1: 1.25, and 1: 0.9 to 1: 1. .1 is particularly preferable.
When the ratio of the amount of the epoxy compound (a-3a) used and the amount of the unsaturated group-containing carboxylic acid (a-3b) used is 1: 0.5 to 1: 2 in the above equivalent ratio, the crosslinking efficiency Is preferable because it tends to improve.

(Polybasic acid anhydride (a-3c))
Polybasic acid anhydride (a-3c) is an anhydride of a carboxylic acid having two or more carboxy groups.
The polybasic acid anhydride (a-3c) is not particularly limited, and for example, phthalic anhydride, succinic anhydride, phthalic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride are used. Phthalic anhydride, methyltetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic dianhydride, 3-methylhexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, 3-ethylhexa Hydrophthalic anhydride, 4-ethylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, 3-methyltetrahydrophthalic anhydride, 4-methyltetrahydrophthalic anhydride, 3-ethyltetrahydrophthalic anhydride, 4-ethyltetrahydrophthalic anhydride , The compound represented by the following formula (a-3c-1), and the compound represented by the following formula (a-3c-2) can be mentioned. Further, the polybasic acid anhydride (a-3c) may be used alone or in combination of two or more.

（式（ａ−３ｃ−２）中、Ｒ^ａ８は、炭素原子数１以上１０以下の置換基を有してもよいアルキレン基を示す。）

(In the formula (a-3c-2), R ^a8 represents an alkylene group which may have a substituent having 1 or more and 10 or less carbon atoms.)

The polybasic acid anhydride (a-3c) is preferably a compound having two or more benzene rings because it is easy to obtain a photosensitive composition having an excellent balance between sensitivity and developability. Further, the polybasic acid anhydride (a-3c) contains at least one of the compound represented by the above formula (a-3c-1) and the compound represented by the above formula (a-3c-2). Is more preferable.

The method of reacting the epoxy compound (a-3a) with the unsaturated group-containing carboxylic acid (a-3b) and then the polybasic acid anhydride (a-3c) can be appropriately selected from known methods.
The amount used is the number of moles of OH groups in the component after the reaction between the epoxy compound (a-3a) and the unsaturated group-containing carboxylic acid (a-3b), and the polybasic acid anhydride (a-3c). ), The equivalent ratio of the acid anhydride groups is usually 1: 1 to 1: 0.1, preferably 1: 0.8 to 1: 0.2. Within the above range, it is easy to obtain a photosensitive composition having good developability.

The acid value of the modified epoxy resin (a-III) is preferably 10 mgKOH / g or more and 150 mgKOH / g or less, and more preferably 70 mgKOH / g or more and 110 mgKOH / g or less in terms of resin solid content. Sufficient solubility in a developing solution can be obtained by setting the acid value of the resin to 10 mgKOH / g or more, and sufficient curability can be obtained by setting the acid value to 150 mgKOH / g or less to improve the surface property. Can be good.

The weight average molecular weight of the modified epoxy resin (a-III) is preferably 1000 or more and 40,000 or less, and more preferably 2000 or more and 30,000 or less. When the weight average molecular weight is 1000 or more, it is easy to form a cured film having excellent heat resistance and strength. Further, when it is 40,000 or less, it is easy to obtain a photosensitive composition showing sufficient solubility in a developing solution.

[Acrylic resin (a-IV)]
Acrylic resin (a-IV) is also preferable as a component constituting the alkali-soluble resin (A). The alkali-soluble resin (A) preferably contains an acrylic resin (a-IV) because it is easy to achieve both the formation of a cured product having a low dielectric constant and good patterning characteristics.

The ratio of the mass of the acrylic resin (a-IV) to the total mass of the alkali-soluble resin (A) is typically preferably 70% by mass or more, more preferably 80% by mass or more, and further 90% by mass or more. Preferably, 95% by mass or more is even more preferable, and 100% by mass is particularly preferable.

As the acrylic resin (a-IV), a resin containing a structural unit derived from (meth) acrylic acid and / or a structural unit derived from another monomer such as (meth) acrylic acid ester can be used. The (meth) acrylic acid is acrylic acid or methacrylic acid. As the other monomer, a compound represented by the following formula (a-4-1) is typically preferably used.

In the above formula (a-4-1), R ^a9 is a hydrogen atom or a methyl group. ^Ra10 is a monovalent organic group. This organic group may contain a bond or a substituent other than the hydrocarbon group such as a hetero atom in the organic group. Further, the organic group may be linear, branched or cyclic. R ^a11 is a group represented by −O− or −NR ^{a12−. Ra12} is a hydrogen atom or an alkyl group having 1 or more and 6 or less carbon atoms.

The substituent other than a hydrocarbon group in the organic group R ^a10, the effect is not particularly limited as long as they do not impair the present invention, a halogen atom, a hydroxyl group, a mercapto group, a sulfide group, a cyano group, an isocyano group, a cyanato group , Isocyanato group, thiocyanato group, isothiocyanato group, silyl group, silanol group, alkoxy group, alkoxycarbonyl group, carbamoyl group, thiocarbamoyl group, nitro group, nitroso group, carboxy group, carboxylate group, acyl group, acyloxy group, sulfino Group, sulfo group, sulfonate group, phosphino group, phosphinyl group, phosphono group, phosphonato group, hydroxyimino group, alkyl ether group, alkyl thioether group, aryl ether group, aryl thioether group, amino group (-NH ₂ , -NHR, -NRR': R and R'independently indicate a hydrocarbon group) and the like. The hydrogen atom contained in the above substituent may be substituted with a hydrocarbon group. The hydrocarbon group contained in the substituent may be linear, branched or cyclic.

The organic group as R ^a10 is acryloyloxy group, methacryloyloxy group, an epoxy group, may have a reactive functional group such as oxetanyl group.
Acyl groups having unsaturated double bonds, such as acryloyloxy groups and methacryloyloxy groups, can be added to at least a part of epoxy groups in an acrylic resin (a-IV) containing a structural unit having an epoxy group, for example. It can be produced by reacting an unsaturated carboxylic acid such as acrylic acid or methacrylic acid.
An unsaturated carboxylic acid may be reacted with at least a part of the epoxy group, and then the polybasic acid anhydride may be reacted with the group produced by the reaction.

Specific examples of polybasic acid anhydrides include phthalic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methylhexahydrophthalic anhydride, and methyltetrahydrophthalic anhydride. Trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic dianhydride, 3-methylhexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, 3-ethylhexahydrophthalic anhydride, 4-ethylhexa Examples thereof include hydrophthalic anhydride, tetrahydrophthalic anhydride, 3-methyltetrahydrophthalic anhydride, 4-methyltetrahydrophthalic anhydride, 3-ethyltetrahydrophthalic anhydride, 4-ethyltetrahydrophthalic anhydride and the like.

As a specific example, when acrylic acid is reacted with a structural unit derived from glycidyl methacrylate, a structural unit having a hydroxyl group shown in the following reaction formula is generated. By reacting a polybasic acid anhydride such as tetrahydrophthalic acid with the structural unit having such a hydroxyl group, a structural unit having an carboxy group and an unsaturated double bond and imparting alkali solubility to the resin is generated.

Further, by reacting a constituent unit derived from an unsaturated carboxylic acid such as acrylic acid or methacrylic acid possessed by the acrylic resin (a-IV) with a compound having an epoxy group and an unsaturated double bond. , An unsaturated double bond can be introduced into the acrylic resin (a-IV). As the compound having an epoxy group and an unsaturated double bond, for example, glycidyl (meth) acrylate or a compound represented by the formulas (a-4-1a) to (a-4-1o) described later is used. Can be done.

As R ^a10 , an alkyl group, an aryl group, a cycloalkyl group, a polycycloalkyl group, a cycloalkylalkyl group, a polycycloalkylalkyl group, an aralkyl group, or a heterocyclic group is preferable, and these groups are a halogen atom and a hydroxyl group. , An alkyl group, or a heterocyclic group may be substituted, and an oxygen atom may be bonded to these groups to form an epoxy group. When these groups contain an alkylene moiety, the alkylene moiety may be interrupted by an ether bond, a thioether bond, or an ester bond.

When the alkyl group is linear or branched, the number of carbon atoms thereof is preferably 1 or more and 20 or less, more preferably 1 or more and 15 or less, and particularly preferably 1 or more and 10 or less. Examples of suitable alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, sec. -Pentyl group, tert-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, isooctyl group, sec-octyl group, tert-octyl group, n-nonyl group, isononyl group, n-decyl group, Examples include an isodecyl group.

In the cycloalkyl group, polycycloalkyl group, cycloalkylalkyl group, polycycloalkylalkyl group, and alicyclic group-containing groups other than these groups, a preferable example of the alicyclic group contained in these groups is , Cyclopentyl group, cyclopentyl group and other monocyclic alicyclic groups, adamantyl group, norbornyl group, isobornyl group, tricyclononyl group, tricyclodecyl group, tetracyclododecyl group, bicyclo- [2.1.1] -Hexyl group, bicyclo- [2.2.1] -heptyl group, bicyclo- [2.2.2] -octyl group, bicyclo- [3.3.0] -octyl group, bicyclo- [4.3. Examples thereof include polycycloalkyl groups such as 0] -nonyl group and bicyclo- [44.0] -decyl group.

Preferable for a compound represented by the formula (a4-1) and having a cycloalkyl group, a polycycloalkyl group, a cycloalkylalkyl group, a polycycloalkylalkyl group, and an alicyclic group-containing group other than these groups as ^Ra10. Examples thereof include compounds represented by the following formulas (a-4-1a) to (a-4-1h). Among these, in order to obtain appropriate developability, compounds represented by the following formulas (a-4-1c) to (a-4-1h) are preferable, and the following formulas (a-4-1c), Alternatively, a compound represented by the following formula (a-4-1d) is more preferable.

In the above formulas, R ^a20 represents a hydrogen atom or a methyl group, R ^a21 is a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms, R ^a22 is the number of hydrogen atoms or carbon atoms 1 Shows up to 5 alkyl groups. As ^Ra21 , a single bond, linear or branched alkylene group, for example, a methylene group, an ethylene group, a propylene group, a tetramethylene group, an ethylethylene group, a pentamethylene group, or a hexamethylene group is preferable. As R ^a22 , for example, a methyl group and an ethyl group are preferable.

The alkali-soluble resin (A) preferably contains an acrylic resin containing a structural unit (A-1) derived from polycycloalkyl (meth) acrylate from the viewpoint of easily forming a cured product having a low dielectric constant.
That is, the acrylic resin is represented by any one of the above formulas (a4-1c) ~ ^(a4-1h), preferably includes a structural unit derived from a compound having a single bond as ^{R a21.} Since the easily particularly a cured product having a low dielectric constant, an acrylic resin has the formula (a4-1c), represented by formula (a4-1d), or Formula ^(a4-1g), a single bond as ^{R a21} It is more preferable to include the structural unit derived from the compound having the compound as the structural unit (A-1).

The amount of the above-mentioned structural unit (A-1) in the acrylic resin is not particularly limited as long as the object of the present invention is not impaired. The amount of the above-mentioned structural unit (A-1) in the acrylic resin is preferably 10% by mass or more and 50% by mass or more, and is 20% by mass or more and 40% by mass or less with respect to the amount of all the structural units. Is more preferable, and 22% by mass or more and 35% by mass or less is further preferable.

The compound represented by the formula (a-4-1) is, in a case having a chain groups having an epoxy group as R ^a10, specific examples of the compound represented by the formula (a-4-1) is, Examples thereof include (meth) acrylic acid epoxyalkyl esters such as glycidyl (meth) acrylate, 2-methylglycidyl (meth) acrylate, 3,4-epoxybutyl (meth) acrylate, and 6,7-epoxyheptyl (meth) acrylate. ..

Further, the compound represented by the formula (a-4-1) may be an alicyclic epoxy group-containing (meth) acrylic acid ester. The alicyclic group constituting the alicyclic epoxy group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic group include cycloalkyl groups such as cyclopentyl group and cyclohexyl group. Examples of the polycyclic alicyclic group include polycycloalkyl groups such as norbornyl group, isobornyl group, tricyclononyl group, tricyclodecyl group and tetracyclododecyl group.

The alkali-soluble resin (A) preferably contains a structural unit (A-2) derived from a (meth) acrylate containing an alicyclic epoxy group, from the viewpoint of easily forming a cured product having a low dielectric constant.
Specific examples of the case where the compound represented by the formula (a-4-1) is a (meth) acrylate containing an alicyclic epoxy group include the following formulas (a-4-1i) to (a-4-1). Examples thereof include the compound represented by 1w). Among these, in order to obtain appropriate developability, compounds represented by the following formulas (a-4-1i) to (a-4-1m) are preferable, and the following formulas (a-4-1i) to (a-4-1i) to The compound represented by (a-4-1k) is more preferable.

In the above formula, Ra ²³ represents a hydrogen atom or a methyl group, Ra ²⁴ represents a divalent aliphatic saturated hydrocarbon group having 1 or more and 6 or less ^{carbon atoms, and Ra 25} represents 2 having 1 or more and 10 or less carbon atoms. It indicates a valent hydrocarbon group, and t indicates an integer of 0 or more and 10 or less. As ^Ra24 , a linear or branched alkylene group, for example, a methylene group, an ethylene group, a propylene group, a tetramethylene group, an ethylethylene group, a pentamethylene group, or a hexamethylene group is preferable. ^{Examples of Ra25} include a methylene group, an ethylene group, a propylene group, a tetramethylene group, an ethylethylene group, a pentamethylene group, a hexamethylene group, a phenylene group, a cyclohexylene group, and -CH ₂ -Ph-CH _2- (Ph is (Indicating a phenylene group) is preferable.

The amount of the structural unit (A-2) derived from the (meth) acrylate containing an alicyclic epoxy group in the acrylic resin (a-IV) is not particularly limited as long as the object of the present invention is not impaired. It is preferably mass% or more and 75 mass% or less, and more preferably 50 mass% or more and 73 mass% or less. When such a resin is used, it is possible to cause a self-reaction between the carboxyl group contained in the resin and the alicyclic epoxy group. Therefore, when a photosensitive composition containing such a resin is used, a film formed by causing a self-reaction between a carboxyl group and an alicyclic epoxy group by using a method of heating the film or the like. It is possible to improve mechanical properties such as hardness of.

Further, the acrylic resin (a-IV) may be obtained by polymerizing a monomer other than the (meth) acrylic acid ester. Examples of such a monomer include (meth) acrylamides, unsaturated carboxylic acids, allyl compounds, vinyl ethers, vinyl esters, styrenes and the like. These monomers can be used alone or in combination of two or more.

Examples of (meth) acrylamides include (meth) acrylamide, N-alkyl (meth) acrylamide, N-aryl (meth) acrylamide, N, N-dialkyl (meth) acrylamide, N, N-aryl (meth) acrylamide, and N. Examples thereof include -methyl-N-phenyl (meth) acrylamide and N-hydroxyethyl-N-methyl (meth) acrylamide.

Examples of unsaturated carboxylic acids include monocarboxylic acids such as crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, and itaconic acid; and anhydrides of these dicarboxylic acids.

Examples of the allyl compound include allyl esters such as allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, and allyl lactate; allyloxyethanol; and the like. Can be mentioned.

Examples of vinyl ethers include hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethyl hexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinyl ether and hydroxyethyl vinyl ether. , Diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether and other alkyl vinyl ethers; vinyl phenyl ether, vinyl trill ether, vinyl chlorophenyl ether, vinyl-2,4-dichlorophenyl ether. , Vinyl aryl ethers such as vinyl naphthyl ethers and vinyl anthranyl ethers; and the like.

Examples of vinyl esters include vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl ballerate, vinyl caproate, vinyl chloro acetate, vinyl dichloro acetate, vinyl methoxy acetate, vinyl butoxy acetate, and vinyl phenyl. Examples thereof include acetate, vinyl acetoacetate, vinyl lactate, vinyl-β-phenylbutyrate, vinyl benzoate, vinyl salicylate, vinyl chlorobenzoate, vinyl tetrachlorobenzoate, vinyl naphthoate and the like.

Examples of styrenes include styrene; methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, isopropylstyrene, butylstyrene, hexylstyrene, cyclohexylstyrene, decylstyrene, benzylstyrene, chloromethylstyrene, trifluoromethylstyrene, ethoxy. Alkylstyrene such as methylstyrene and acetoxymethylstyrene; alkoxystyrene such as methoxystyrene, 4-methoxy-3-methylstyrene and dimethoxystyrene; chlorostyrene, dichlorostyrene, trichlorostyrene, tetrachlorostyrene, pentachlorostyrene, bromostyrene, Examples thereof include halostyrene such as dibromostyrene, iodostyrene, fluorostyrene, trifluorostyrene, 2-bromo-4-trifluoromethylstyrene, and 4-fluoro-3-trifluoromethylstyrene.

The amount of the structural unit derived from (meth) acrylic acid and the amount of the structural unit derived from other monomers in the acrylic resin (a-IV) are not particularly limited as long as the object of the present invention is not impaired. The amount of the structural unit derived from (meth) acrylic acid in the acrylic resin (a-IV) is 5% by mass or more and 50% by mass with respect to the number of moles of all the structural units of the acrylic resin (a-IV). The following is preferable, and 10% by mass or more and 30% by mass or less is more preferable.

When the acrylic resin (a-IV) has a structural unit having an unsaturated double bond, the amount of the structural unit having an unsaturated double bond in the acrylic resin (a-IV) is the acrylic resin (a). -IV) is preferably 1% by mass or more and 50% by mass or less, more preferably 1% by mass or more and 30% by mass or more, and particularly preferably 1% by mass or more and 20% by mass or less with respect to the number of moles of all the constituent units.
Since the acrylic resin (a-IV) contains a structural unit having an unsaturated double bond in an amount within the above range, the acrylic resin can be incorporated into the cross-linking reaction in the resist film and homogenized, so that the cured film can be made uniform. It is effective in improving heat resistance and mechanical properties.

The weight average molecular weight of the acrylic resin (a-IV) is not particularly limited as long as it does not impair the object of the present invention. The weight average molecular weight of the acrylic resin (a-IV) is preferably 9000 or more, more preferably 9000 or more and 50,000 or less, further preferably 9100 or more and 30,000 or less, further preferably 9200 or more and 20000 or less, and particularly preferably 9500 or more and 15000 or less. preferable. Within the above range, the film-forming ability of the photosensitive composition and the developability after exposure tend to be easily balanced.

The content of the alkali-soluble resin (A) is preferably 20% by mass or more and 85% by mass or less with respect to the mass (total solid content) of the photosensitive composition excluding the mass of the organic solvent (S) described later. , 25% by mass or more and 75% by mass or less is more preferable. Within the above range, it is easy to obtain a photosensitive composition having excellent developability.

<Photopolymerizable compound (B)>
As the photopolymerizable compound (B), a monomer having an ethylenically unsaturated group can be preferably used. The photopolymerizable compound contains, as the monomer having an ethylenically unsaturated group, a polyfunctional compound having 3 or 4 (meth) acryloyl groups. By curing such a polyfunctional compound with a specific photopolymerization initiator (C) described later, it is easy to form a well-patterned cured product having a low dielectric constant.

The photopolymerizable compound (B) may contain other photopolymerizable compounds other than the polyfunctional compound having 3 or 4 (meth) acryloyl groups as long as the object of the present invention is not impaired. The other photopolymerizable compound may be a monofunctional compound or a bifunctional compound, or may be a polyfunctional compound having five or more functionalities. The ratio of the mass of the polyfunctional compound having 3 or 4 (meth) acryloyl groups to the mass of the photopolymerizable compound (B) is preferably 80% by mass or more, more preferably 90% by mass or more, and 95% by mass or more. More preferably, 100% by mass is particularly preferable.

Specific examples of the polyfunctional compound having 3 or 4 (meth) acryloyl groups include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and glycerin tri (meth). ) Acrylate and the like can be mentioned. These polyfunctional monomers can be used alone or in combination of two or more.

From the viewpoint of easily forming a cured product having a low dielectric constant, the polyfunctional compound having 3 or 4 (meth) acryloyl groups preferably contains a compound having a partial skeleton represented by the following formula (B1). Typically, the partial skeleton represented by formula (B1) is derived from trimethylolpropane.

（式（Ｂ２）中、Ｒ^ｂ１は、それぞれ独立に水素原子又はメチル基であり、Ｒ^ｂ２は２価の連結基であり、ａ１は０又は１であり、ａ２は０又は１である。） The photopolymerizable compound (B) preferably contains a compound represented by the following formula (B2) as a polyfunctional compound having a partial skeleton represented by the formula (B1).

(In the formula (B2), R ^b1 is an independent hydrogen atom or a methyl group, R ^b2 is a divalent linking group, a1 is 0 or 1, and a2 is 0 or 1.)

In the formula (B2), when a1 is 0, the compound represented by the formula (B2) is a trifunctional compound. When a1 is 1, the compound represented by the formula (B2) is a tetrafunctional compound.

^{R b2} in the formula (B2) is a divalent linking group. The linking group may be a hydrocarbon group or an organic group containing a hetero atom. Heteroatoms that the linking group may contain include, for example, O, N, S, Se, P, Si, B, and halogen atoms.

Preferred examples of the divalent linking ^{group, -CO -, - R b3 -} , - CO-R b3 -CO -, - R b3 -CO -, - R b4 -O-R b4 -, - R b4 ^{-S-R b4} -, and ^{-R b4 -CO-R} b4 - group represented by the like. R ^b3 is a divalent hydrocarbon group having 1 or more and 10 or less carbon atoms. R ^b4 is a divalent hydrocarbon group having 1 or more and 6 or less carbon atoms.
^{Among the groups described above, -CO-, -R b3-} , and -CO-R ^b3- CO- are preferable because the compound represented by the formula (B2) can be easily synthesized and obtained.

Preferred specific examples of the linking group are -CO-, -CH _2- , -CH ₂ CH _2- , -CH = CH-, -CH ₂ CH ₂ CH _2- , -CH ₂ C (CH ₃ ) H-. , -CO-CH _2- CO-,-CO-CH ₂ CH _2- CO-, -CO-CH = CH- _{CO-, -CO-CH 2} CH ₂ CH _2- CO-, -CO-CH ₂ CH _2- and groups having the following structures can be mentioned.

Particularly preferable specific examples of the polyfunctional compound having 3 or 4 (meth) acryloyl groups include the following compounds. In the following formula, R ^b1 is independently a hydrogen atom or a methyl group.

When the photopolymerizable compound (B) contains other photopolymerizable compounds other than the polyfunctional compound having 3 or 4 (meth) acryloyl groups, the other photopolymerizable compounds hinder the object of the present invention. It is not particularly limited as long as it does not. The other photopolymerizable compound may be a monofunctional compound or a bifunctional or pentafunctional or higher functional compound.

Examples of the monofunctional compound include (meth) acrylamide, methylol (meth) acrylamide, methoxymethyl (meth) acrylamide, ethoxymethyl (meth) acrylamide, propoxymethyl (meth) acrylamide, butoxymethoxymethyl (meth) acrylamide, and N-methylol ( Meta) acrylamide, N-hydroxymethyl (meth) acrylamide, (meth) acrylic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, crotonic acid, 2-acrylamide- 2-Methylpropanesulfonic acid, tert-butylacrylamide sulfonic acid, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-hydroxyethyl (Meta) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-phenoxy-2-hydroxypropyl (meth) acrylate, 2- (meth) acryloyloxy-2-hydroxypropylphthalate, Glycerin mono (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, dimethylaminoethyl (meth) acrylate, glycidyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3 -Tetrafluoropropyl (meth) acrylate, half (meth) acrylate of phthalic acid derivative and the like can be mentioned. These monofunctional compounds can be used alone or in combination of two or more.

Examples of the divalent or pentavalent or higher polyfunctional compound include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, and polypropylene glycol di (meth) acrylate. ) Acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexane glycol di (meth) acrylate, glycerin di (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipenta Elythritol hexa (meth) acrylate, pentaerythritol di (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 2,2-bis (4- (meth) acryloxidiethoxyphenyl) Propane, 2,2-bis (4- (meth) acryloxypolyethoxyphenyl) propane, 2-hydroxy-3- (meth) acryloyloxypropyl (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, diethylene glycol Diglycidyl ether di (meth) acrylate, diglycidyl phthalate ester di (meth) acrylate, urethane (meth) acrylate (that is, tolylene diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, etc. and 2-vidroxyethyl (meth) acrylate. , Methylenebis (meth) acrylamide, (meth) acrylamide methylene ether, polyfunctional compounds such as condensates of polyhydric alcohol and N-methylol (meth) acrylamide, triacrylic formal and the like. These polyfunctional compounds can be used alone or in combination of two or more.

Among these other photopolymerizable compounds having an ethylenically unsaturated group, the photosensitive composition has five or more functionalities because it tends to increase the adhesion of the photosensitive composition to the substrate and the strength of the photosensitive composition after curing. Polyfunctional monomers are more preferred.

The content of the photopolymerizable compound (B) in the photosensitive composition is 1% by mass or more and 50% by mass with respect to the mass (total solid content) of the photosensitive composition excluding the mass of the organic solvent (S) described later. % Or less is preferable, and 5% by mass or more and 40% by mass or less is more preferable. Within the above range, it tends to be easy to balance sensitivity, developability, and resolution.

（式（１）中、Ｒ^ｃ１は水素原子、ニトロ基又は１価の有機基であり、Ｒ^ｃ２及びＲ^ｃ３は、それぞれ、置換基を有してもよい鎖状アルキル基、置換基を有してもよい環状有機基、又は水素原子であり、Ｒ^ｃ２とＲ^ｃ３とは相互に結合して環を形成してもよく、Ｒ^ｃ４は１価の有機基であり、Ｒ^ｃ５は、水素原子、置換基を有してもよい炭素原子数１以上１１以下のアルキル基、又は置換基を有してもよいアリール基であり、ｎ１は０以上４以下の整数であり、ｎ２は０又は１である。） <Photopolymerization initiator (C)>
The photosensitive composition contains a compound represented by the following formula (1) as the photopolymerization initiator (C).
By curing the above-mentioned photopolymerizable compound (B) by exposure in the presence of a photopolymerization initiator (C) containing the compound represented by the formula (1), a cured product having a low dielectric constant is satisfactorily patterned. can do.

(In the formula (1), R ^c1 is a hydrogen atom, a nitro group or a monovalent organic group, and R ^c2 and R ^c3 each have a chain alkyl group and a substituent which may have a substituent. It may be a cyclic organic group or a hydrogen atom, and R ^c2 and R ^c3 may be bonded to each other to form a ring, R ^c4 is a monovalent organic group, and R ^c5 is hydrogen. An atom, an alkyl group having 1 or more and 11 or less carbon atoms which may have a substituent, or an aryl group which may have a substituent, n1 is an integer of 0 or more and 4 or less, and n2 is 0 or It is 1.)

In formula (1), R ^c1 is a hydrogen atom, a nitro group or a monovalent organic group. R ^c1 is attached to a 6-membered aromatic ring on the fluorene ring in the formula (1), which is different from the 6-membered aromatic ring attached to the group represented by _{− (CO) n2-.} In the formula (1), the ^{binding position of R c1} with respect to the fluorene ring is not particularly limited. When the compound represented by the formula (1) has 1 or more R ^{c1 , one of the 1 or more R c1} is a fluorene ring because the compound represented by the formula (1) can be easily synthesized. It is preferable to bind to the 2-position of the inside. If R ^c1 is more, the plurality of R ^c1 may be the same or different.

When R ^c1 is an organic group, R ^c1 is not particularly limited as long as it does not interfere with the object of the present invention, and is appropriately selected from various organic groups. Preferable examples of the case where R ^c1 is an organic group include an alkyl group, an alkoxy group, a cycloalkyl group, a cycloalkoxy group, a saturated aliphatic acyl group, a saturated aliphatic acyloxy group, an alkoxycarbonyl group and a substituent. A phenyl group which may have a substituent, a phenoxy group which may have a substituent, a benzoyl group which may have a substituent, a phenoxycarbonyl group which may have a substituent, and a benzoyloxy which may have a substituent. A group, a phenylalkyl group which may have a substituent, a naphthyl group which may have a substituent, a naphthoxy group which may have a substituent, a naphthoyl group which may have a substituent, and a substituent. It has a naphthoxycarbonyl group which may have a substituent, a naphthyloxy group which may have a substituent, a naphthylalkyl group which may have a substituent, a heterocyclyl group which may have a substituent, and a substituent. Examples thereof include a heterocyclylcarbonyl group, an amino group substituted with one or two organic groups, a morpholin-1-yl group, a piperazine-1-yl group and the like.

When R ^c1 is an alkyl group, the number of carbon atoms of the alkyl group is preferably 1 or more and 20 or less, and more preferably 1 or more and 6 or less. When R ^c1 is an alkyl group, it may be a straight chain or a branched chain. Specific examples of the case where R ^c1 is an alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group and an n-pentyl group. , Isopentyl group, sec-pentyl group, tert-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, isooctyl group, sec-octyl group, tert-octyl group, n-nonyl group, isononyl group, Examples thereof include an n-decyl group and an isodecyl group. When R ^c1 is an alkyl group, the alkyl group may contain an ether bond (−O−) in the carbon chain. Examples of the alkyl group having an ether bond in the carbon chain include a methoxyethyl group, an ethoxyethyl group, a methoxyethoxyethyl group, an ethoxyethoxyethyl group, a propyloxyethoxyethyl group, a methoxypropyl group and the like.

When R ^c1 is an alkoxy group, the number of carbon atoms of the alkoxy group is preferably 1 or more and 20 or less, and more preferably 1 or more and 6 or less. When R ^c1 is an alkoxy group, it may be a straight chain or a branched chain. Specific examples of the case where R ^c1 is an alkoxy group include a methoxy group, an ethoxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, an isobutyloxy group, a sec-butyloxy group, a tert-butyloxy group and n. -Pentyloxy group, isopentyloxy group, sec-pentyloxy group, tert-pentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, isooctyloxy group, sec-octyloxy group , Trt-octyloxy group, n-nonyloxy group, isononyloxy group, n-decyloxy group, isodecyloxy group and the like. When R ^c1 is an alkoxy group, the alkoxy group may contain an ether bond (−O−) in the carbon chain. Examples of the alkoxy group having an ether bond in the carbon chain include methoxyethoxy group, ethoxyethoxy group, methoxyethoxyethoxy group, ethoxyethoxyethoxy group, propyloxyethoxyethoxy group, methoxypropyloxy group and the like.

When R ^c1 is a cycloalkyl group or a cycloalkoxy group, the number of carbon atoms of the cycloalkyl group or cycloalkoxy group is preferably 3 or more and 10 or less, and more preferably 3 or more and 6 or less. Specific examples of the case where R ^c1 is a cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group and the like. Specific examples of the case where R ^c1 is a cycloalkoxy group include a cyclopropyloxy group, a cyclobutyloxy group, a cyclopentyloxy group, a cyclohexyloxy group, a cycloheptyloxy group, a cyclooctyloxy group and the like.

When R ^c1 is a saturated aliphatic acyl group or a saturated aliphatic acyloxy group, the number of carbon atoms of the saturated aliphatic acyl group or the saturated aliphatic acyloxy group is preferably 2 or more and 21 or less, and more preferably 2 or more and 7 or less. Specific examples of the case where R ^c1 is a saturated aliphatic acyl group include an acetyl group, a propanoyl group, an n-butanoyl group, a 2-methylpropanoyl group, an n-pentanoyl group, a 2,2-dimethylpropanoyl group and n. -Hexanoyl group, n-heptanoyl group, n-octanoyl group, n-nonanoyl group, n-decanoyl group, n-undecanoyl group, n-dodecanoyl group, n-tridecanoyl group, n-tetradecanoyl group, n-pentadeca Examples thereof include a noyl group and an n-hexadecanoyl group. Specific examples of the case where R ^c1 is a saturated aliphatic acyloxy group include an acetyloxy group, a propanoyloxy group, an n-butanoyloxy group, a 2-methylpropanoyloxy group, an n-pentanoyloxy group, 2, 2-Dimethylpropanoyloxy group, n-hexanoyloxy group, n-heptanoyloxy group, n-octanoyloxy group, n-nonanoyloxy group, n-decanoyloxy group, n-undecanoyloxy group, n -Dodecanoyloxy group, n-tridecanoyloxy group, n-tetradecanoyloxy group, n-pentadecanoyloxy group, n-hexadecanoyloxy group and the like can be mentioned.

When R ^c1 is an alkoxycarbonyl group, the number of carbon atoms of the alkoxycarbonyl group is preferably 2 or more and 20 or less, and more preferably 2 or more and 7 or less. Specific examples of the case where R ^c1 is an alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, an n-propyloxycarbonyl group, an isopropyloxycarbonyl group, an n-butyloxycarbonyl group, an isobutyloxycarbonyl group, and sec-butyl. Oxycarbonyl group, tert-butyloxycarbonyl group, n-pentyloxycarbonyl group, isopentyloxycarbonyl group, sec-pentyloxycarbonyl group, tert-pentyloxycarbonyl group, n-hexyloxycarbonyl group, n-heptyloxycarbonyl group Group, n-octyloxycarbonyl group, isooctyloxycarbonyl group, sec-octyloxycarbonyl group, tert-octyloxycarbonyl group, n-nonyloxycarbonyl group, isononyloxycarbonyl group, n-decyloxycarbonyl group, and Examples thereof include an isodecyloxycarbonyl group.

When R ^c1 is a phenylalkyl group, the number of carbon atoms of the phenylalkyl group is preferably 7 or more and 20 or less, and more preferably 7 or more and 10 or less. When R ^c1 is a naphthylalkyl group, the number of carbon atoms of the naphthylalkyl group is preferably 11 or more and 20 or less, and more preferably 11 or more and 14 or less. Specific examples of the case where R ^c1 is a phenylalkyl group include a benzyl group, a 2-phenylethyl group, a 3-phenylpropyl group, and a 4-phenylbutyl group. Specific examples of the case where R ^c1 is a naphthylalkyl group include α-naphthylmethyl group, β-naphthylmethyl group, 2- (α-naphthyl) ethyl group, and 2- (β-naphthyl) ethyl group. .. When R ^c1 is a phenylalkyl group or a naphthylalkyl group, ^Rc1 may further have a substituent on the phenyl group or the naphthyl group.

When R ^c1 is a heterocyclyl group, the heterocyclyl group is a 5- or 6-membered monocycle containing one or more N, S, O, or the monocycles are fused together, or the monocycle and the benzene ring are condensed. Heterocyclyl group. When the heterocyclyl group is a fused ring, the number of rings of the monocycle constituting the fused ring is 3 or less. The heterocyclyl group may be an aromatic group (heteroaryl group) or a non-aromatic group. Examples of the heterocycle constituting the heterocyclyl group include furan, thiophene, pyrrol, oxazole, isooxazole, thiazole, thiadiazol, isothiazole, imidazole, pyrazole, triazole, pyridine, pyrazine, pyrimidine, pyridazine, benzofuran, benzothiophene, and indol. Isoindole, indridin, benzimidazole, benzotriazole, benzoxazole, benzothiazole, carbazole, purine, quinoline, isoquinoline, quinazoline, phthalazine, cinnoline, quinoxaline, piperidine, piperazine, morpholine, piperidine, tetrahydropyran, tetrahydrofuran and the like. Be done. When R ^c1 is a heterocyclyl group, the heterocyclyl group may further have a substituent.

When R ^c1 is a heterocyclylcarbonyl group, the heterocyclyl group contained in the heterocyclylcarbonyl group is the same as when ^Rc1 is a heterocyclyl group.

When R ^c1 is an amino group substituted with 1 or 2 organic groups, suitable examples of the organic group are an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, and the like. Saturated aliphatic acyl group having 2 or more and 21 or less carbon atoms, phenyl group which may have a substituent, benzoyl group which may have a substituent, and 7 or more and 20 carbon atoms which may have a substituent. The following phenylalkyl groups, naphthyl groups which may have substituents, naphthoyl groups which may have substituents, naphthylalkyl groups which may have substituents and have 11 to 20 carbon atoms, and heterocyclyl. The group etc. can be mentioned. Specific examples of these suitable organic groups are the same as for R ^c1 . Specific examples of the amino group substituted with the organic group 1 or 2 include a methylamino group, an ethylamino group, a diethylamino group, an n-propylamino group, a di-n-propylamino group, an isopropylamino group, and an n-. Butylamino group, di-n-butylamino group, n-pentylamino group, n-hexylamino group, n-heptylamino group, n-octylamino group, n-nonylamino group, n-decylamino group, phenylamino group, Naftylamino group, acetylamino group, propanoylamino group, n-butanoylamino group, n-pentanoylamino group, n-hexanoylamino group, n-heptanoylamino group, n-octanoylamino group, n- Examples thereof include a decanoylamino group, a benzoylamino group, an α-naphthoylamino group, and a β-naphthoylamino group.

When ^{the phenyl group, naphthyl group, and heterocyclyl group contained in R c1} further have a substituent, the substituents include an alkyl group having 1 to 6 carbon atoms and an alkoxy group having 1 to 6 carbon atoms. Saturated aliphatic acyl group with 2 to 7 carbon atoms, alkoxycarbonyl group with 2 to 7 carbon atoms, saturated aliphatic acyloxy group with 2 to 7 carbon atoms, alkyl group with 1 to 6 carbon atoms Examples thereof include a monoalkylamino group having, a dialkylamino group having an alkyl group having 1 or more and 6 or less carbon atoms, a morpholin-1-yl group, a piperazine-1-yl group, a halogen, a nitro group, a cyano group and the like. When ^{the phenyl group, naphthyl group, and heterocyclyl group contained in R c1} further have a substituent, the number of the substituent is not limited as long as the object of the present invention is not impaired, but is preferably 1 or more and 4 or less. When ^{the phenyl group, the naphthyl group, and the heterocyclyl group contained in R c1} have a plurality of substituents, the plurality of substituents may be the same or different.

Among the groups described above, as R ^c1 , a nitro group or ^{a group represented by R c10} −CO− tends to improve the sensitivity and is preferable. R ^c10 is not particularly limited as long as it does not interfere with the object of the present invention, and can be selected from various organic groups. Examples of a suitable group as R ^c10 include an alkyl group having 1 to 20 carbon atoms, a phenyl group which may have a substituent, a naphthyl group which may have a substituent, and a substituent. Heterocyclyl groups may be mentioned. Among these groups, 2-methylphenyl group, thiophen-2-yl group, and α-naphthyl group are particularly preferable as R ^c10.
Further, when R ^c1 is a hydrogen atom, the transparency tends to be good, which is preferable. If R ^c1 is a hydrogen atom and R ^c4 is a group represented by the formula (1a) or (1b) described later, the transparency tends to be better.

In the formula (1), R ^c2 and R ^c3 are a chain alkyl group which may have a substituent, a cyclic organic group which may have a substituent, or a hydrogen atom, respectively. R ^c2 and R ^c3 may be coupled to each other to form a ring. Among these groups, a chain alkyl group which may have a substituent is preferable as ^{R c2} and R ^c3. When R ^c2 and R ^c3 are chain alkyl groups which may have a substituent, the chain alkyl group may be a linear alkyl group or a branched alkyl group.

When R ^c2 and R ^c3 are chain alkyl groups having no substituent, the number of carbon atoms of the chain alkyl group is preferably 1 or more and 20 or less, more preferably 1 or more and 10 or less, and particularly preferably 1 or more and 6 or less. preferable. Specific examples of cases where R ^c2 and R ^c3 are chain alkyl groups include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. , N-Pentyl group, Isopentyl group, sec-Pentyl group, tert-Pentyl group, n-Hexyl group, n-Heptyl group, n-octyl group, isooctyl group, sec-octyl group, tert-octyl group, n-nonyl Examples thereof include a group, an isononyl group, an n-decyl group, and an isodecyl group. Further, when R ^c2 and R ^c3 are alkyl groups, the alkyl group may contain an ether bond (-O-) in the carbon chain. Examples of the alkyl group having an ether bond in the carbon chain include a methoxyethyl group, an ethoxyethyl group, a methoxyethoxyethyl group, an ethoxyethoxyethyl group, a propyloxyethoxyethyl group, a methoxypropyl group and the like.

When R ^c2 and R ^c3 are chain alkyl groups having a substituent, the number of carbon atoms of the chain alkyl group is preferably 1 or more and 20 or less, more preferably 1 or more and 10 or less, and particularly preferably 1 or more and 6 or less. .. In this case, the number of carbon atoms of the substituent is not included in the number of carbon atoms of the chain alkyl group. The chain alkyl group having a substituent is preferably linear.
The substituent that the alkyl group may have is not particularly limited as long as it does not impair the object of the present invention. Preferable examples of the substituent include a cyano group, a halogen atom, a cyclic organic group, and an alkoxycarbonyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Among these, a fluorine atom, a chlorine atom and a bromine atom are preferable. Examples of the cyclic organic group include a cycloalkyl group, an aromatic hydrocarbon group, and a heterocyclyl group. Specific examples of the cycloalkyl group are the same as in the preferred example when ^{R c1 is a cycloalkyl group.} Specific examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, a biphenylyl group, an anthryl group, a phenanthryl group and the like. Specific examples of the heterocyclyl group are the same as in the preferred example when ^{R c1 is a heterocyclyl group.} When R ^c1 is an alkoxycarbonyl group, the alkoxy group contained in the alkoxycarbonyl group may be linear or branched, preferably linear. The number of carbon atoms of the alkoxy group contained in the alkoxycarbonyl group is preferably 1 or more and 10 or less, and more preferably 1 or more and 6 or less.

When the chain alkyl group has a substituent, the number of the substituent is not particularly limited. The number of preferred substituents depends on the number of carbon atoms in the chain alkyl group. The number of substituents is typically 1 or more and 20 or less, preferably 1 or more and 10 or less, and more preferably 1 or more and 6 or less.

When R ^c2 and R ^c3 are cyclic organic groups, the cyclic organic group may be an alicyclic group or an aromatic group. Examples of the cyclic organic group include an aliphatic cyclic hydrocarbon group, an aromatic hydrocarbon group, and a heterocyclyl group. When R ^c2 and R ^c3 are cyclic organic groups, the substituents that the cyclic organic group may have are the same as when R ^c2 and R ^c3 are chain alkyl groups.

When R ^c2 and R ^c3 are aromatic hydrocarbon groups, is the aromatic hydrocarbon group a phenyl group or a group formed by bonding a plurality of benzene rings via a carbon-carbon bond? , It is preferable that the group is formed by condensing a plurality of benzene rings. When the aromatic hydrocarbon group is a phenyl group or a group formed by bonding or condensing a plurality of benzene rings, the number of rings of the benzene ring contained in the aromatic hydrocarbon group is not particularly limited. 3 or less is preferable, 2 or less is more preferable, and 1 is particularly preferable. Preferred specific examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, a biphenylyl group, an anthryl group, a phenanthryl group and the like.

When R ^c2 and R ^c3 are aliphatic cyclic hydrocarbon groups, the aliphatic cyclic hydrocarbon group may be monocyclic or polycyclic. The number of carbon atoms of the aliphatic cyclic hydrocarbon group is not particularly limited, but is preferably 3 or more and 20 or less, and more preferably 3 or more and 10 or less. Examples of monocyclic cyclic hydrocarbon groups include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, norbornyl group, isobornyl group, tricyclononyl group, tricyclodecyl group, Examples thereof include a tetracyclododecyl group and an adamantyl group.

When R ^c2 and R ^c3 are heterocyclyl groups, the heterocyclyl group is a 5- or 6-membered monocycle containing one or more N, S, O, such monocyclic rings, or such monocyclic and benzene rings. Is a heterocyclyl group condensed with. When the heterocyclyl group is a fused ring, the number of rings of the monocycle constituting the fused ring is 3 or less. The heterocyclyl group may be an aromatic group (heteroaryl group) or a non-aromatic group. Examples of the heterocycle constituting the heterocyclyl group include furan, thiophene, pyrrol, oxazole, isooxazole, thiazole, thiadiazol, isothiazole, imidazole, pyrazole, triazole, pyridine, pyrazine, pyrimidine, pyridazine, benzofuran, benzothiophene, and indol. Isoindole, indridin, benzimidazole, benzotriazole, benzoxazole, benzothiazole, carbazole, purine, quinoline, isoquinoline, quinazoline, phthalazine, cinnoline, quinoxaline, piperidine, piperazine, morpholine, piperidine, tetrahydropyran, tetrahydrofuran and the like. Be done.

R ^c2 and R ^c3 may be coupled to each other to form a ring. The group consisting of the ring formed by ^{R c2} and R ^{c3 is preferably a cycloalkylidene group.} When R ^c2 and R ^c3 are bonded to form a cycloalkylidene group, the ring constituting the cycloalkylidene group is preferably a 5-membered ring or a 6-membered ring, and more preferably a 5-membered ring.

When ^{the group formed by combining R c2} and R ^c3 is a cycloalkylidene group, the cycloalkylidene group may be condensed with one or more other rings. Examples of rings that may be fused with a cycloalkylene group include a benzene ring, a naphthalene ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, a cyclooctane ring, a furan ring, a thiophene ring, a pyrrole ring, and a pyridine. Rings, pyrazine rings, pyrimidine rings and the like can be mentioned.

Examples of suitable groups among ^{R c2} and R ^c3 described above include groups represented by the ^{formula −A 1} −A ^2. In the formula, A ¹ is a linear alkylene group, and A ² is an alkoxy group, a cyano group, a halogen atom, an alkyl halide group, a cyclic organic group, or an alkoxycarbonyl group.

The ^{number of carbon atoms of the linear alkylene group of A 1} is preferably 1 or more and 10 or less, and more preferably 1 or more and 6 or less. When A ² is an alkoxy group, the alkoxy group may be linear or branched, preferably linear. The number of carbon atoms of the alkoxy group is preferably 1 or more and 10 or less, and more preferably 1 or more and 6 or less. When A ² is a halogen atom, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom are preferable, and a fluorine atom, a chlorine atom and a bromine atom are more preferable. When A ² is an alkyl halide group, the halogen atom contained in the alkyl halide group is preferably a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and more preferably a fluorine atom, a chlorine atom or a bromine atom. The alkyl halide group may be linear or branched, and is preferably linear. When A ² is a cyclic organic group, examples of the cyclic organic group are the same as those of the cyclic organic group that ^{R c2} and R ^{c3 have as substituents.} When A ² is an alkoxycarbonyl group, examples of the alkoxycarbonyl group are similar to those of the alkoxycarbonyl group that ^{R c2} and R ^{c3 have as substituents.}

Preferable specific examples of R ^c2 and R ^c3 include alkyl groups such as ethyl group, n-propyl group, n-butyl group, n-hexyl group, n-heptyl group, and n-octyl group; 2-methoxyethyl. Group, 3-methoxy-n-propyl group, 4-methoxy-n-butyl group, 5-methoxy-n-pentyl group, 6-methoxy-n-hexyl group, 7-methoxy-n-heptyl group, 8-methoxy -N-octyl group, 2-ethoxyethyl group, 3-ethoxy-n-propyl group, 4-ethoxy-n-butyl group, 5-ethoxy-n-pentyl group, 6-ethoxy-n-hexyl group, 7- Alkyl alkyl groups such as ethoxy-n-heptyl group and 8-ethoxy-n-octyl group; 2-cyanoethyl group, 3-cyano-n-propyl group, 4-cyano-n-butyl group, 5-cyano-n Cyanalkyl groups such as −pentyl group, 6-cyano-n-hexyl group, 7-cyano-n-heptyl group, and 8-cyano-n-octyl group; 2-phenylethyl group, 3-phenyl-n-propyl Phenyl such as group, 4-phenyl-n-butyl group, 5-phenyl-n-pentyl group, 6-phenyl-n-hexyl group, 7-phenyl-n-heptyl group, and 8-phenyl-n-octyl group. Alkyl group; 2-cyclohexylethyl group, 3-cyclohexyl-n-propyl group, 4-cyclohexyl-n-butyl group, 5-cyclohexyl-n-pentyl group, 6-cyclohexyl-n-hexyl group, 7-cyclohexyl-n -Heptyl group, 8-cyclohexyl-n-octyl group, 2-cyclopentylethyl group, 3-cyclopentyl-n-propyl group, 4-cyclopentyl-n-butyl group, 5-cyclopentyl-n-pentyl group, 6-cyclopentyl- Cycloalkylalkyl groups such as n-hexyl group, 7-cyclopentyl-n-heptyl group, and 8-cyclopentyl-n-octyl group; 2-methoxycarbonylethyl group, 3-methoxycarbonyl-n-propyl group, 4-methoxy Carbonyl-n-butyl group, 5-methoxycarbonyl-n-pentyl group, 6-methoxycarbonyl-n-hexyl group, 7-methoxycarbonyl-n-heptyl group, 8-methoxycarbonyl-n-octyl group, 2-ethoxy Carbonyl ethyl group, 3-ethoxycarbonyl-n-propyl group, 4-ethoxycarbonyl-n-butyl group, 5-ethoxycarbonyl-n-pentyl group, 6-ethoxycarbonyl-n-hexyl group, 7-etoki An alkoxycarbonylalkyl group such as a sicarbonyl-n-heptyl group and an 8-ethoxycarbonyl-n-octyl group; 2-chloroethyl group, 3-chloro-n-propyl group, 4-chloro-n-butyl group, 5- Chloro-n-pentyl group, 6-chloro-n-hexyl group, 7-chloro-n-heptyl group, 8-chloro-n-octyl group, 2-bromoethyl group, 3-bromo-n-propyl group, 4- Bromo-n-butyl group, 5-bromo-n-pentyl group, 6-bromo-n-hexyl group, 7-bromo-n-heptyl group, 8-bromo-n-octyl group, 3,3,3-tri Examples thereof include a fluoropropyl group and an alkyl halide group such as 3,3,4,4,5,5,5-heptafluoro-n-pentyl group.

Among the above-mentioned suitable groups as R ^c2 and R ^c3 are ethyl group, n-propyl group, n-butyl group, n-pentyl group, 2-methoxyethyl group, 2-cyanoethyl group and 2-phenylethyl group. 2-Cyclohexylethyl group, 2-methoxycarbonylethyl group, 2-chloroethyl group, 2-bromoethyl group, 3,3,3-trifluoropropyl group, and 3,3,4,5,5,5-hepta It is a fluoro-n-pentyl group.

Examples of suitable organic groups for R ^c4 include alkyl groups, alkoxy groups, cycloalkyl groups, cycloalkoxy groups, saturated aliphatic acyl groups, alkoxycarbonyl groups, saturated aliphatic acyloxy groups and substituents ^{, as in R c1.} A phenyl group which may have a substituent, a phenoxy group which may have a substituent, a benzoyl group which may have a substituent, a phenoxycarbonyl group which may have a substituent, and a substituent. A good benzoyloxy group, a phenylalkyl group which may have a substituent, a naphthyl group which may have a substituent, a naphthoxy group which may have a substituent, a naphthoyl group which may have a substituent, A naphthoxycarbonyl group which may have a substituent, a naphthyloxy group which may have a substituent, a naphthylalkyl group which may have a substituent, a heterocyclyl group which may have a substituent, and a substituent. Examples thereof include a heterocyclylcarbonyl group which may have a group, an amino group substituted with one or two organic groups, a morpholin-1-yl group, a piperazine-1-yl group and the like. Specific examples of these groups are similar to those described for ^{R c1.} Further, as R ^c4 , a cycloalkylalkyl group, a phenoxyalkyl group which may have a substituent on the aromatic ring, and a phenylthioalkyl group which may have a substituent on the aromatic ring are also preferable. The substituents that the phenoxyalkyl group and the phenylthioalkyl group may have are the same as the substituents that the phenyl group contained ^{in R c1 may have.}

Among the organic groups, R ^c4 includes an alkyl group, a cycloalkyl group, a phenyl group which may have a substituent, or a cycloalkylalkyl group, and a phenylthio which may have a substituent on the aromatic ring. Alkyl groups are preferred. As the alkyl group, an alkyl group having 1 to 20 carbon atoms is preferable, an alkyl group having 1 to 8 carbon atoms is more preferable, an alkyl group having 1 to 4 carbon atoms is particularly preferable, and a methyl group is the most preferable. preferable. Among the phenyl groups that may have a substituent, a methylphenyl group is preferable, and a 2-methylphenyl group is more preferable. The number of carbon atoms of the cycloalkyl group contained in the cycloalkylalkyl group is preferably 5 or more and 10 or less, more preferably 5 or more and 8 or less, and particularly preferably 5 or 6. The number of carbon atoms of the alkylene group contained in the cycloalkylalkyl group is preferably 1 or more and 8 or less, more preferably 1 or more and 4 or less, and particularly preferably 2. Among the cycloalkylalkyl groups, a cyclopentylethyl group is preferable. The number of carbon atoms of the alkylene group contained in the phenylthioalkyl group which may have a substituent on the aromatic ring is preferably 1 or more and 8 or less, more preferably 1 or more and 4 or less, and particularly preferably 2. Among the phenylthioalkyl groups that may have a substituent on the aromatic ring, a 2- (4-chlorophenylthio) ethyl group is preferable.

^As the ^{R c4,} the group represented by -A 3 ^{-CO-O-A 4} are also preferred. A ³ is a divalent organic group, preferably a divalent hydrocarbon group, and preferably an alkylene group. A ⁴ is a monovalent organic group is preferably a monovalent hydrocarbon group.

When A ³ is an alkylene group, the alkylene group may be linear or branched, preferably linear. When A ³ is an alkylene group, the number of carbon atoms of the alkylene group is preferably 1 or more and 10 or less, more preferably 1 or more and 6 or less, and particularly preferably 1 or more and 4 or less.

Preferred examples of A ^4, the number 1 to 10 alkyl group carbon atoms, having 7 or more carbon atoms and 20 or less aralkyl group, and an aromatic hydrocarbon group having 6 to 20 carbon atoms. Specific preferable examples of A ⁴ is methyl group, ethyl group, n- propyl group, an isopropyl group, n- butyl group, isobutyl group, sec- butyl group, tert- butyl group, n- pentyl group, n- hexyl Examples thereof include a group, a phenyl group, a naphthyl group, a benzyl group, a phenethyl group, an α-naphthylmethyl group, a β-naphthylmethyl group and the like.

Preferable specific examples of the group represented by −A ³ −CO—O—A ⁴ include 2-methoxycarbonylethyl group, 2-ethoxycarbonylethyl group, 2-n-propyloxycarbonylethyl group, 2-n. -Butyloxycarbonylethyl group, 2-n-pentyloxycarbonylethyl group, 2-n-hexyloxycarbonylethyl group, 2-benzyloxycarbonylethyl group, 2-phenoxycarbonylethyl group, 3-methoxycarbonyl-n-propyl Group, 3-ethoxycarbonyl-n-propyl group, 3-n-propyloxycarbonyl-n-propyl group, 3-n-butyloxycarbonyl-n-propyl group, 3-n-pentyloxycarbonyl-n-propyl group , 3-n-hexyloxycarbonyl-n-propyl group, 3-benzyloxycarbonyl-n-propyl group, 3-phenoxycarbonyl-n-propyl group and the like.

（式（１ａ）及び式（１ｂ）中、Ｒ^ｃ７及びＲ^ｃ８はそれぞれ有機基であり、ｎ３は０以上４以下の整数であり、Ｒ^ｃ７及びＲ^ｃ８がベンゼン環上の隣接する位置に存在する場合、Ｒ^ｃ７とＲ^ｃ８とが互いに結合して環を形成してもよく、ｎ４は１以上８以下の整数であり、ｎ５は１以上５以下の整数であり、ｎ６は０以上（ｎ５＋３）以下の整数であり、Ｒ^ｃ９は有機基である。） ^Having described ^{R c4,} as the ^{R c4,} preferably a group represented by the following formula (1a) or the following formula (1b).

(In formulas (1a) and (1b), R ^c7 and R ^c8 are organic groups, respectively, n3 is an integer of 0 or more and 4 or less, and R ^c7 and R ^c8 are present at adjacent positions on the benzene ring. If you ^may be bonded with ^{R c7} and ^{R c8} each other to form a ring, n4 is 1 to 8 integer, n5 is 1 to 5 integer, n6 is 0 or more (n5 + 3 ) It is the following integer, and R ^c9 is an organic group.)

Examples of organic groups for ^{R c7} and R ^{c8 in} formula (1a) are similar to ^{R c1.} As R ^c7 , an alkyl group or a phenyl group is preferable. When R ^c7 is an alkyl group, the number of carbon atoms thereof is preferably 1 or more and 10 or less, more preferably 1 or more and 5 or less, particularly preferably 1 or more and 3 or less, and most preferably 1. That is, R ^c7 is most preferably a methyl group. When R ^c7 and R ^c8 combine to form a ring, the ring may be an aromatic ring or an aliphatic ring. Preferable examples of the group represented by the formula (1a) in which R ^c7 and R ^c8 form a ring include a naphthalene-1-yl group and 1,2,3,4-. Examples thereof include a tetrahydronaphthalene-5-yl group. In the above formula (1a), n3 is an integer of 0 or more and 4 or less, preferably 0 or 1, and more preferably 0.

In the above formula (1b), R ^c9 is an organic group. Examples of the organic group include groups similar to the organic group described for ^{R c1.} Among the organic groups, an alkyl group is preferable. The alkyl group may be linear or branched. The number of carbon atoms of the alkyl group is preferably 1 or more and 10 or less, more preferably 1 or more and 5 or less, and particularly preferably 1 or more and 3 or less. As R ^c9 , a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group and the like are preferably exemplified, and among these, a methyl group is more preferable.

In the above formula (1b), n5 is an integer of 1 or more and 5 or less, preferably an integer of 1 or more and 3 or less, and more preferably 1 or 2. In the above formula (1b), n6 is 0 or more (n5 + 3) or less, an integer of 0 or more and 3 or less is preferable, an integer of 0 or more and 2 or less is more preferable, and 0 is particularly preferable. In the above formula (1b), n4 is an integer of 1 or more and 8 or less, an integer of 1 or more and 5 or less is preferable, an integer of 1 or more and 3 or less is more preferable, and 1 or 2 is particularly preferable.

In the formula (1), R ^c5 is a hydrogen atom, an alkyl group having 1 to 11 carbon atoms which may have a substituent, or an aryl group which may have a substituent. As the ^{substituent which may be possessed when R c5} is an alkyl group, a phenyl group, a naphthyl group and the like are preferably exemplified. Further, ^{as the substituent which may be possessed when R c1} is an aryl group, an alkyl group having 1 or more and 5 or less carbon atoms, an alkoxy group, a halogen atom and the like are preferably exemplified.

In the formula (1), as R ^c5 , a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a phenyl group, a benzyl group, a methylphenyl group, a naphthyl group and the like are preferably exemplified. Of these, a methyl group or a phenyl group is more preferable.

Preferable specific examples of the compound represented by the formula (1) include the following PI-1 to PI-41.

The photosensitive composition may contain, as the photopolymerization initiator (C), another photopolymerization initiator in addition to the compound represented by the above formula (1). The other photopolymerization initiator is not particularly limited as long as it is a photopolymerization initiator that does not correspond to the compound represented by the above formula (1).

Suitable examples of other photopolymerization initiators are commercially available as 2- (benzoyloxyimino) -1- [4- (phenylthio) phenyl] -1-octanone (eg, OXE-01 (manufactured by BASF)). ), And O-acetyl-1- [6- (2-methylbenzoyl) -9-ethyl-9H-carbazole-3-yl] etanone oxime (eg, OXE-02 (manufactured by BASF)). An oxime ester compound having a structure not corresponding to the above formula (C1), such as 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butane-1-one, 2-methyl-1-. [4- (Methylthio) phenyl] -2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1- (4-dimethylaminophenyl) butane-1-one, 2- (4-methylbenzyl) -2-Diethylamino-1- (4-morpholinophenyl) butane-1-one, 2-methyl-1-phenyl-2-morpholinopropane-1-one, 2-methyl-1- [4- (hexyl) phenyl] Α-Aminoketone compounds such as -2-morpholinopropane-1-one, 2-ethyl-2-dimethylamino-1- (4-morpholinophenyl) butane-1-one; 1-phenyl-2-hydroxy-2-one Methylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane-1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, Α-Hydroxyketone photopolymerization initiators such as 1-hydroxycyclohexylphenyl ketone; benzoin photopolymerization initiators such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether and benzyl methyl ketal; benzophenone, benzoyl benzoic acid, Benzoyl-based photopolymerization initiators such as methyl benzoyl benzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylicized benzophenone, 4-benzoyl, 4'-methyldiphenylsulfide, 4,4'-bisdiethylaminobenzophenone; thioxanthone, 2-chloro Thioxanthone-based photopolymerization initiators such as thioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone; 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -S-Triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2-pipenyl-4 .6-bis (trichloromethyl) -s-triazine, 2,4-bis (trichloromethyl) -6-styryl-s-triazine, 2- (naphth-1-yl) -4,6-bis (trichloromethyl) −S-triazine, 2- (4-methoxy-naphtho-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, 2, 4-Trichloromethyl- (4'-methoxystyryl) -6-triazine, 2- [4- (4-methoxystyryl) phenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, etc. Triazine-based photopolymerization initiator; Carbazole-based photopolymerization initiator; 2,2'-bis (2-chlorophenyl) -4,4', 5,5'-tetrakis (4-ethoxycarbonylphenyl) -1,2'- Biimidazole, 2,2'-bis (2-bromophenyl) -4,4', 5,5'-tetrakis (4-ethoxycarbonylphenyl) -1,2'-biimidazole, 2,2'-bis ( 2-Chlorophenyl) -4,4', 5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis (2,4-dichlorophenyl) -4,4', 5,5'- Tetraphenyl-1,2'-biimidazole, 2,2'-bis (2,4,6-trichlorophenyl) -4,4', 5,5'-tetraphenyl-1,2'-biimidazole, 2 , 2'-bis (2-bromophenyl) -4,4,5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis (2,4-dibromophenyl) -4,4 ', 5,5'-Tetraphenyl-1,2'-biimidazole, 2,2'-bis (2,4,6-tribromophenyl) -4,4', 5,5'-tetraphenyl-1 , 2'-Bimidazole-based photopolymerization initiator such as biimidazole; benzimidazoline-based photopolymerization initiator as represented by the following formula is exemplified.

Suitable specific examples of the compound represented by the above formula (1) other than the above include the following compounds.

The ratio of the mass of the compound represented by the above formula (1) to the mass of the photopolymerization initiator (C) is not particularly limited as long as it does not impair the object of the present invention. The ratio of the compound represented by the above formula (1) to the mass of the photopolymerization initiator (C) is preferably 50% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, and 90% by mass. It is even more preferably mass% or more, and particularly preferably 100% by mass.

The content of the photopolymerization initiator (C) is preferably 0.1% by mass or more and 30% by mass or less, more preferably 0.5% by mass or more and 20% by mass or less, based on the total mass of the solid content of the photosensitive composition. preferable. By setting the content of the photopolymerization initiator (C) in the above range, it is possible to obtain a photosensitive composition having good curability and less likely to have a defective pattern shape.

<Organic solvent (S)>
The photosensitive composition may typically contain an organic solvent (S) for the purpose of adjusting the coatability or the like. Examples of the organic solvent (S) include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol-n-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol mono-n. -Propyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n- (Poly) such as butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, etc. ) Alkylene glycol monoalkyl ethers; (poly) alkylene such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, etc. Glycol monoalkyl ether acetates; Other ethers such as diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, tetrahydrofuran; Ketones such as methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-heptanone; Methyl 2-hydroxypropionate, Lactate alkyl esters such as ethyl 2-hydroxypropionate; ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, 3-ethoxypropionic acid Ethyl, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybuty Lupropionate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, n-pentyl formate, isopentyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, n-butyl butyrate , Methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl 2-oxobutanoate and other esters; aromatic hydrocarbons such as toluene and xylene; N-methylpyrrolidone , N, N-dimethylformamide, N, N-dimethylacetamide and other amides and the like. These solvents may be used alone or in combination of two or more.

The amount of the organic solvent (S) used can be appropriately determined depending on the use of the photosensitive composition. As an example, the amount of the organic solvent (S) used is an amount in which the solid content concentration of the photosensitive composition is in the range of 1% by mass or more and 50% by mass or less.

<Other ingredients>
The photosensitive composition may contain various other additives, if necessary. Specific examples thereof include dispersion aids, fillers, fillers, adhesion promoters, antioxidants, ultraviolet absorbers, anti-aggregation agents, thermal polymerization inhibitors, defoamers, surfactants and the like.

Examples of the thermal polymerization inhibitor used in the photosensitive composition include hydroquinone and hydroquinone monoethyl ether. Further, examples of the defoaming agent include silicone-based and fluorine-based compounds, and examples of the surfactant include anionic, cationic and nonionic compounds.

<Method for preparing photosensitive composition>
The photosensitive composition is prepared by uniformly mixing each of the above-mentioned components in a desired amount. When the prepared photosensitive composition does not contain an insoluble component such as a pigment, the photosensitive composition may be filtered using a filter so as to be uniform.

≪Manufacturing method of cured product≫
The photosensitive compositions described above typically have
Molding the photosensitive composition according to the shape of the cured product,
Exposure to the molded photosensitive composition and
It is made into a cured product by a method including.

The cured product produced by the above method preferably has a relative permittivity of 2.86 or less, more preferably 2.84 or less, still more preferably 2.80 or less, and particularly preferably 2.77 or less. Therefore, the produced cured product can be used for applications requiring a low dielectric constant, for example, an insulating film or the like. Further, since the produced cured product has high transparency, it is useful for display devices such as OLEDs, organic ELs, and liquid crystal displays, and is useful for flattening films, interlayer insulating films, protective films for color filters, and liquid crystal display devices. It can be suitably used as a spacer for keeping the thickness of the liquid crystal layer constant in the above, a microlens in a solid-state image sensor, or the like.

The method for molding the photosensitive composition is not particularly limited, and is appropriately selected depending on the shape of the cured product. The shape of the cured product is not limited to these, and examples thereof include a film shape, a lens shape, a line shape, and a prism shape. Among these shapes, the film shape is preferable.
The method for molding the photosensitive composition is not particularly limited. When the shape of the cured product is a lens shape, a prism shape, or the like, the photosensitive composition may be filled in a mold according to the shape of the cured product using a squeegee or the like.
When the shape of the cured product is a line shape or the like, the photosensitive composition may be applied onto the substrate according to the shape of the cured product. Examples of the coating method include a printing method such as an inkjet method.
As a method of applying the photosensitive composition to the film shape, a contact transfer type coating device such as a roll coater, a reverse coater, or a bar coater, or a non-contact type coating device such as a spinner (rotary coating device) or a curtain flow coater is used. The method can be mentioned. Further, the photosensitive composition can be applied to the film shape by a printing method such as an inkjet method.

The thickness of the coating film is not particularly limited. The thickness of the coating film is preferably 0.05 μm or more, more preferably 1 μm or more. The thickness of the coating film may be, for example, 7 μm or more, and may be 10 μm or more. There is no particular upper limit to the thickness of the coating film, but it may be, for example, 50 μm or less, or 20 μm or less. The thickness of the coating film is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 2 μm or less.
The range of the thickness of the coating film is preferably 0.05 μm or more and 10 μm or less, more preferably 1 μm or more and 5 μm or less, and further preferably 1 μm or more and 2 μm or less.

The coating film is then dried, if necessary. The drying method is not particularly limited. Examples of the drying method include (1) drying on a hot plate at a temperature of 80 ° C. or higher and 120 ° C. or lower, preferably 90 ° C. or higher and 100 ° C. or lower for 60 seconds or longer and 120 seconds or lower, and (2) room temperature. Examples include a method of leaving the mixture for several hours to several days, and (3) a method of removing the solvent by putting it in a warm air heater or an infrared heater for several tens of minutes to several hours.

A cured film is formed by exposing such a coating film.

The light source is not particularly limited in the exposure, and examples thereof include a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a xenon lamp, a carbon arc lamp, and an LED. Using such a light source, ArF excimer laser coating film, KrF excimer laser, _{F 2} excimer laser, extreme ultraviolet (EUV), vacuum ultraviolet (VUV), electron beams, X-rays, soft X-ray, g-line, i-line , H-rays, j-rays, k-rays and the like, or electromagnetic waves can be applied to expose the coating film.

Exposure dose varies depending on the composition of the photosensitive composition, for example, 10 mJ / cm ² or more 2000 mJ / cm ² or less are preferred, 100 mJ / cm ² or more 1500 mJ / cm ² and more preferably less, 200 mJ / cm ² or more 1200 mJ / cm ² or less is more preferable. The exposure illuminance varies depending on the composition of the photosensitive composition, but is preferably in the range of ^{1 mW / cm 2} or more and 50 mW / cm ^{2 or less.}

The cured film cured by exposure may be heated. The temperature at the time of heating is not particularly limited, and is preferably 180 ° C. or higher and 280 ° C. or lower, more preferably 200 ° C. or higher and 260 ° C. or lower, and particularly preferably 220 ° C. or higher and 250 ° C. or lower. The heating time is typically preferably 1 minute or more and 60 minutes or less, more preferably 10 minutes or more and 50 minutes or less, and particularly preferably 20 minutes or more and 40 minutes or less.

On the other hand, the coating film may be exposed to position selection. In this case, the coating film is exposed position-selectively through a negative mask having a light-transmitting portion having a shape corresponding to the pattern shape of the cured film.
The exposure method is the same as the above-mentioned exposure method except that a negative mask is used.

The exposed coating film is then developed with a developer to form a patterned cured film. The developing method is not particularly limited, and for example, a dipping method, a spraying method, or the like can be used. Examples of the developing solution include organic ones such as monoethanolamine, diethanolamine and triethanolamine, and aqueous solutions such as sodium hydroxide, potassium hydroxide, sodium carbonate, ammonia and quaternary ammonium salts.

The patterned cured film obtained after development may be heated in the same manner as in the method of exposing the patterned coating film described above.

By using the above-mentioned photosensitive composition, a pattern having a desired shape can be satisfactorily formed even when a fine pattern is formed.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[Examples 1 to 4, Comparative Examples 1 to 5]
In Examples and Comparative Examples, the acrylic resin P1 having the following structure and the acrylic resin P2 having the following structure were used as the alkali-soluble resin (A). The polystyrene-equivalent weight average molecular weights of the resin P1 and the resin P2 are both 10,000.

In Examples and Comparative Examples, the following B-1 to B-4 were used as the photopolymerizable compound (B).
B-1: Trimethylolpropane triacrylate B-2: Ditrimethylolpropane tetraacrylate B-3: Dipentaerythritol hexaacrylate B-4: ε-caprolactone-modified dipentaerythritol hexaacrylate (KAYARAD DPCA-120, Nippon Kayaku Co., Ltd.) Made)

In Examples and Comparative Examples, the following C-1 and C-2 were used as the photopolymerization initiator (C).

13.73 parts by mass of the alkali-soluble resin (A) (component (A)) of the type shown in Table 1 and 6.8 parts by mass of the photopolymerizable compounds (B) (component (B)) of the type shown in Table 1. Parts, 1.22 parts by mass of photopolymerizable compounds (C) (component (C)) of the types shown in Table 1, 31.2 parts by mass of diethylene glycol methyl ethyl ether, and 46.7 parts by mass of propylene glycol monomethyl ether acetate. 0.2 parts by mass of 3-glycidyloxypropyltrimethoxysilane, 0.05 parts by mass of a surfactant (BYK-310, manufactured by Big Chemie), and an antioxidant (IR1010, manufactured by BASF Japan) 0. 1 part by mass was mixed to obtain a photosensitive composition of each Example and each Comparative Example.

Using the obtained photosensitive composition, the relative permittivity and the patterning property were evaluated according to the following method. The results of these evaluations are shown in Table 1.

<Relative permittivity measurement>
The mercury probe method was used as a method for measuring the relative permittivity. SSM-495 (manufactured by Nippon Semilab Co., Ltd.) was used as an apparatus capable of measuring the relative permittivity by the mercury probe method. By the following steps 1) to 4), a film-like cured product having a film thickness of 1 μm was formed using the compositions of each Example and Comparative Example. Then, the relative permittivity of the formed cured product was measured.
1) A curing composition is applied onto a silicon wafer to form a coating film.
2) The formed coating film is heated at 100 ° C. for 120 seconds.
3) The coating film is exposed at an exposure amount of ^{1 J / cm 2.}
4) The exposed coating film is heated at 230 ° C. for 20 minutes.

<Evaluation of patterning property>
The curable compositions of each Example and Comparative Example were applied onto a glass substrate using a spin coater and heated at 100 ° C. for 120 seconds to form a coating film. Next, using a proximity exposure machine (product name: TME-150RTO, manufactured by Topcon Co., Ltd.), ultraviolet rays (i-rays) were applied to the coating film at 50 mJ / cm via a negative mask for forming a hole pattern of 20 μm × 20 μm. Irradiation was performed with an exposure amount of ^2. The exposed coating film was developed with a 2.38 mass% TMAH aqueous solution at 25 ° C. for 50 seconds and then post-baked at 230 ° C. for 30 minutes to form a hole pattern. The obtained pattern was observed with an optical microscope, and the hole shape was evaluated according to the following criteria.
〇: The square shape of the light-shielding part of the mask is reproduced in the holes in the hole pattern, and the mask transferability is good.
X: The square shape of the light-shielding part of the mask is not reproduced in the holes in the hole pattern, and the mask transferability is poor.

According to Table 1, the photosensitive composition of the example containing a combination of a polyfunctional compound having 3 or 4 acryloyl groups and C-1 corresponding to the compound represented by the formula (1) is used. It can be seen that the formation of a cured product having a low relative permittivity and good patterning property can be achieved at the same time.
On the other hand, the photosensitive composition of the comparative example containing no combination of the polyfunctional compound having 3 or 4 acryloyl groups and the compound represented by the formula (1) is good in forming a cured product having a low dielectric constant. It was not possible to achieve both good patterning properties.

Claims (8)

It contains an alkali-soluble resin (A), a photopolymerizable compound (B), and a photopolymerization initiator (C).
The photopolymerizable compound (B) contains a polyfunctional compound having 3 or 4 (meth) acryloyl groups.
A photosensitive composition in which the photopolymerization initiator (C) contains a compound represented by the following formula (1).

(In the formula (1), R ^c1 is a hydrogen atom, a nitro group or a monovalent organic group, and R ^c2 and R ^c3 each have a chain alkyl group and a substituent which may have a substituent. It may be a cyclic organic group or a hydrogen atom, and R ^c2 and R ^c3 may be bonded to each other to form a ring, R ^c4 is a monovalent organic group, and R ^c5 is hydrogen. An atom, an alkyl group having 1 or more and 11 or less carbon atoms which may have a substituent, or an aryl group which may have a substituent, n1 is an integer of 0 or more and 4 or less, and n2 is 0 or It is 1.) The photosensitive composition according to claim 1, wherein the polyfunctional compound having 3 or 4 (meth) acryloyl groups comprises a compound having a partial skeleton represented by the following formula (B1).

The photosensitive composition according to claim 2, wherein the polyfunctional compound having 3 or 4 (meth) acryloyl groups contains a compound represented by the following formula (B2).

(In the formula (B2), R ^b1 is an independent hydrogen atom or a methyl group, R ^b2 is a divalent linking group, a1 is 0 or 1, and a2 is 0 or 1.) The photosensitive composition according to any one of claims 1 to 3, wherein the alkali-soluble resin (A) contains an acrylic resin. The photosensitive composition according to claim 4, wherein the acrylic resin contains a structural unit (A-1) derived from polycycloalkyl (meth) acrylate. The photosensitive composition according to claim 5, wherein the acrylic resin contains a structural unit (A-2) derived from a (meth) acrylate containing an alicyclic epoxy group. The cured product of the photosensitive composition according to any one of claims 1 to 6. The photosensitive composition according to any one of claims 1 to 6 is molded according to the shape of the cured product to be formed.
Exposure to the molded photosensitive composition and
A method for producing a cured product including.