JP7629273B2 - Photosensitive resin composition, cured product thereof, and display device including the cured product - Google Patents

Description

The present invention relates to a photosensitive resin composition, a cured product thereof, and a display device including the cured product.

Display elements such as liquid crystal display elements, organic electroluminescence elements (organic EL elements), and electronic paper elements are provided with hardened films such as protective films to prevent deterioration and damage to electronic components including touch panels, interlayer insulating films to maintain insulation between wiring arranged in layers, and flattening films to increase the aperture ratio. Conventionally, a transparent hardened film (hereinafter also referred to as a protective film) has been formed as a protective layer on the surface of a color filter used in the manufacture of a color liquid crystal display (LCD). The protective film of a color filter is formed for the purpose of flattening the unevenness that occurs between the pixels of the color filter and improving the reliability of the color liquid crystal display. The protective film of a color filter is required to have excellent flatness, developability, transparency, etc.

For example, in terms of flatness, it is required that unevenness of about 1 to 2 μm in height that occurs when the coloring composition is applied in layers to form pixels be flattened to 0.2 μm or less. In terms of developability, it is required that thin lines of about 20 μm can be formed without peeling or jagged edges in the pattern. In terms of transparency, it is required that the protective film does not absorb in the visible light wavelength range so as not to impair the color characteristics of the color filter.

In addition to the above-mentioned required characteristics for the protective film, the high performance of LCD panels has led to the demand for a wide viewing angle and high-speed response, and as display methods such as IPS (In-plane Switching) mode have come to be used, the required characteristics for the protective film have also become stricter. In display methods such as IPS mode, if gaseous or liquid components or water generated or bleed out from the color filter layer enter the liquid crystal layer through the protective layer, the concentration of moisture or ionic impurities in the liquid crystal layer increases, or bubbles form in the liquid crystal, causing display defects. For this reason, it is particularly important to prevent the passage of the above-mentioned impurity components, as well as to have low gas generation properties, since gas generation from the protective film in direct contact with the liquid crystal layer directly leads to display defects. In addition, in recent years, there has been a demand for thinner LCD panels, so there is also a demand for thinner protective films, and the demand for flatness, such as achieving flatness under a thin film, is also becoming stricter. In other words, a new challenge has arisen, such as achieving both low gas generation and flatness.

As materials for protective films of color filters, many compositions of epoxy or acrylic compounds have been proposed (e.g., Patent Documents 1 to 5), but no material has been found that simultaneously satisfies the required properties of low gas generation and flatness.
On the other hand, siloxane epoxy resins having 3,4-epoxycyclohexyl groups (Patent Document 6) and materials using the same for forming cured films or as materials for color filters (Patent Documents 7 to 9, etc.) have been proposed, but they do not focus on the siloxane structure in detail, and there is no discussion of low gas generation or flatness (Patent Documents 7 to 8, etc.).

WO 96/34303 JP 2000-103937 A JP 2000-143772 A JP 2001-091732 A JP 2004-069930 A WO2015/151957 JP 2005-338790 A JP 2012-241118 A JP 2017-171748 A

As mentioned above, protective films for color filters must meet the required characteristics of low moisture absorption, low gas generation, and flatness, while also maintaining high levels of essential properties for protective films for color filters, such as developability and transparency. However, the range of application of protective film materials that can satisfy these requirements is narrowing as compositions.

Furthermore, in recent years, in addition to RGB, color filters (RGBW type) have been developed that have white (W) pixels to which no coloring composition for the color filter pixels is applied, and the protective film is required to satisfy flatness while filling the W space to which no coloring composition is applied. That is, in addition to the conventional unevenness on the pixel of about 1 to 2 μm, it is now required to flatten even larger concave spaces of 2 to 3 μm with a thin film of 2 μm or less on the color pixel formation area.

The present invention has been made in consideration of the above problems, and aims to provide a photosensitive resin composition capable of forming a protective film that is excellent in developability and transparency while satisfying the required characteristics of flatness, low moisture absorption, and low gas generation, a cured product obtained by curing the photosensitive resin composition, and a display device that uses the cured product as a component.

As a result of investigations conducted by the inventors to solve the problems required for protective films for color filters, as described above, they discovered that the above problems could be solved by using a photosensitive resin composition with a specific formulation, and thus completed the present invention.

〔構造Ｔ１～Ｔ３中、Ｒは水素基、メチル基、エチル基又はフェニル基であり、Ｘは、次の(a)又は(b)であって、同一であっても異なっていてもよいが、各構造において少なくとも１つのＸは(a)である。
(a)３，４－エポキシシクロヘキシル基、又は、炭素数１～６の有機基の末端に３，４－エポキシシクロヘキシル基を有する基
(b)炭素数１～６の有機基〕
〔２〕前記シロキサンエポキシ化合物が、²⁹Si-ＮＭＲスペクトルにおいて、－９ｐｐｍ～－１３ｐｐｍにシグナルを示す下記の構造Ｄ１と－１５ｐｐｍ～－２４ｐｐｍにシグナルを示す下記の構造Ｄ２とを含有することを特徴とする〔１〕に記載の感光性樹脂組成物。

〔構造Ｄ１～Ｄ２中、Ｒは水素基、メチル基、エチル基又はフェニル基であり、Ｙは、前記の(a)又は(b)であって、各構造において同一であっても異なっていてもよい。〕
〔３〕固形分の全質量に対して、前記シロキサンエポキシ化合物の固形分含有量が３質量％以上２５質量％以下であることを特徴とする〔１〕又は〔２〕に記載の感光性樹脂組成物。
〔４〕シロキサン骨格を含まず且つエポキシ基又は重合性不飽和結合を有する非シロキサン型化合物を含有することを特徴とする〔１〕～〔３〕のいずれかに記載の感光性樹脂組成物。
〔５〕非シロキサン型化合物が、下記式（７）で表されるエポキシ化合物であることを特徴とする〔４〕に記載の感光性樹脂組成物。

〔式（７）中、Ａｒは炭素数６～１２の２価の芳香族炭化水素基である。また、Ａｒで表される２価の芳香族炭化水素基の水素原子の一部は、炭素数１～１０の炭化水素基、炭素数１～５のアルコキシ基又はハロゲン基で置換されていてもよい。ｌの平均値は０～２である。〕
〔６〕前記（Ａ）成分は、一般式（１）で表される重合性不飽和基含有アルカリ可溶性樹脂であることを特徴とする〔１〕～〔５〕のいずれかに記載の感光性樹脂組成物。

〔式（１）中、Ｒ_１、Ｒ_２、Ｒ_３及びＲ_４は、それぞれ独立して水素原子、炭素数１～５のアルキル基、ハロゲン原子又はフェニル基を表し、Ｒ_５は、水素原子又はメチル基を表し、Ａは、－ＣＯ－、－ＳＯ_２－、－Ｃ（ＣＦ_３）_２－、－Ｓｉ（ＣＨ_３）_２－、－ＣＨ_２－、－Ｃ（ＣＨ_３）_２－、－Ｏ－、フルオレン－９，９－ジイル基又は直結合を表し、Ｘ_１は４価のカルボン酸残基を表し、Ｙ_１及びＹ_２は、それぞれ独立して水素原子又は－ＯＣ－Ｚ－（ＣＯＯＨ）_ｍ（但し、Ｚは２価又は３価カルボン酸残基を表し、ｍは１又は２の数を表す）を表し、ｎは１～２０の整数を表す。〕
〔７〕前記〔１〕～〔６〕のいずれかに記載の感光性樹脂組成物を硬化してなる硬化物。
〔８〕前記〔７〕に記載の硬化物を構成要素として含む表示装置。 That is, the gist of the present invention is as follows.
[1] (A) an alkali-soluble resin containing a polymerizable unsaturated group;
(B) a photopolymerizable monomer having at least two ethylenically unsaturated bonds;
(C) a siloxane epoxy compound satisfying the following (i) to (iii):
(D) a photopolymerization initiator;
A photosensitive resin composition comprising:
(i) In a ^29Si -NMR spectrum, it has the following structure T1 which shows a signal at -47 ppm to -52 ppm, the following structure T2 which shows a signal at -55 ppm to -61 ppm, and the following structure T3 which shows a signal at -62 ppm to -72 ppm, and the signal area ratio is T1:T2:T3=0-1:1-10:1-100.
(ii) The weight average molecular weight is 750 to 20,000.
(iii) The epoxy equivalent weight is less than 350.

[In structures T1 to T3, R is a hydrogen group, a methyl group, an ethyl group, or a phenyl group, and X is the following (a) or (b), which may be the same or different, but in each structure, at least one X is (a).
(a) a 3,4-epoxycyclohexyl group, or a group having a 3,4-epoxycyclohexyl group at the terminal of an organic group having 1 to 6 carbon atoms
(b) an organic group having 1 to 6 carbon atoms]
[2] The photosensitive resin composition according to [1], characterized in that the siloxane epoxy compound contains the following structure D1, which shows a signal at -9 ppm to -13 ppm in the ²⁹ Si-NMR spectrum, and the following structure D2, which shows a signal at -15 ppm to -24 ppm.

[In structures D1 and D2, R is a hydrogen group, a methyl group, an ethyl group, or a phenyl group, and Y is either (a) or (b) as defined above, and may be the same or different in each structure.]
[3] The photosensitive resin composition according to [1] or [2], wherein the solid content of the siloxane epoxy compound is 3 mass% or more and 25 mass% or less based on the total mass of the solid content.
[4] The photosensitive resin composition according to any one of [1] to [3], which contains a non-siloxane type compound that does not contain a siloxane skeleton and has an epoxy group or a polymerizable unsaturated bond.
[5] The photosensitive resin composition according to [4], wherein the non-siloxane type compound is an epoxy compound represented by the following formula (7):

[In formula (7), Ar is a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. Some of the hydrogen atoms of the divalent aromatic hydrocarbon group represented by Ar may be substituted with a hydrocarbon group having 1 to 10 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a halogen group. The average value of l is 0 to 2.]
[6] The photosensitive resin composition according to any one of [1] to [5], wherein the component (A) is a polymerizable unsaturated group-containing alkali-soluble resin represented by general formula (1).

[In formula (1), R ₁ , R ₂ , R ₃ and R ₄ each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom or a phenyl group; R ₅ represents a hydrogen atom or a methyl group; A represents -CO-, -SO ₂ -, -C(CF ₃ ) ₂ -, -Si(CH ₃ ) ₂ -, -CH ₂ -, -C(CH ₃ ) ₂ -, -O-, a fluorene-9,9-diyl group or a direct bond; X ₁ represents a tetravalent carboxylic acid residue; Y ₁ and Y ₂ each independently represent a hydrogen atom or -OC-Z-(COOH) _m (wherein Z represents a divalent or trivalent carboxylic acid residue and m represents the number 1 or 2); and n represents an integer of 1 to 20.]
[7] A cured product obtained by curing the photosensitive resin composition according to any one of [1] to [6] above.
[8] A display device comprising the cured product according to [7] above as a component.

The photosensitive resin composition of the present invention satisfies the required characteristics of flatness, extremely good low moisture absorption, and low gas generation, and enables the formation of a cured product (cured film) that is also excellent in heat resistance, chemical resistance, electrical reliability, and transparency. The photosensitive resin composition of the present invention can be applied not only as a protective film for the color filter of an LCD including an RGBW type, but also to a display device that requires a transparent cured film that is particularly excellent in flatness and low gas generation. That is, it can be suitably applied as a component of an organic EL display device other than an LCD, a μLED display device, or a display device to which quantum dots are applied, especially when a transparent film that flattens unevenness or steps is required. Furthermore, it can be applied to sensors such as CMOS equipped with a color filter layer. It can also be publicly used as an insulating film layer for semiconductor devices, multilayer printed wiring boards, touch panels, etc., especially when flatness is required. Furthermore, it is widely used in various applications such as optical applications, optodevice applications, machine part materials, electrical and electronic part materials, automobile part materials, civil engineering materials, molding materials, paints, and adhesives, etc., where transparency, heat resistance, low moisture absorption, etc. are required.

The photosensitive resin composition of the present invention contains a predetermined (A) alkali-soluble resin containing a polymerizable unsaturated group, (B) a photopolymerizable monomer having at least two ethylenically unsaturated bonds, (C) an epoxy compound, and (D) a photopolymerization initiator. The photosensitive resin composition may also contain a surfactant, a solvent, and the like. The details of these components will be described below in order.

<(A) Alkali-soluble resin containing polymerizable unsaturated group>
The polymerizable unsaturated group-containing alkali-soluble resin of component (A) can be any resin having a polymerizable unsaturated group and an acidic group in the molecule without any particular limitation. Representative examples of the polymerizable unsaturated group include an acrylic group or a methacrylic group, and a representative example of the acidic group includes a carboxyl group.

The preferred weight average molecular weight (Mw) and acid value range of this polymerizable unsaturated group-containing alkali-soluble resin varies depending on the resin skeleton, but Mw is preferably 2000 to 50,000, and the acid value is preferably 30 to 120 mgKOH/g. If Mw is less than 2000, the adhesion of the pattern during alkaline development may decrease, and if Mw exceeds 50,000, the developability may decrease significantly, making it impossible to obtain a photosensitive resin composition with an appropriate development time. In addition, if the acid value is less than 30, residues are likely to remain during alkaline development, and if the acid value is greater than 120, the penetration of the alkaline developer may be too fast, resulting in peeling development rather than the desired dissolution development. It is more preferable that Mw is 2000 to 25,000, and the acid value is 40 to 110 mgKOH/g. In addition, the polymerizable unsaturated group-containing alkali-soluble resin may be used alone or in combination of two or more types.

A first preferred example of component (A) is an epoxy (meth)acrylate acid adduct obtained by reacting a compound having two or more epoxy groups with (meth)acrylic acid (meaning "acrylic acid and/or methacrylic acid"), and then reacting the resulting epoxy (meth)acrylate compound having a hydroxy group with (I) an acid monoanhydride of a dicarboxylic acid or tricarboxylic acid and/or (II) a tetracarboxylic acid dianhydride. Examples of compounds having two or more epoxy groups that can be derived into epoxy (meth)acrylate acid adducts include bisphenol-type epoxy compounds and novolac-type epoxy compounds.

Bisphenol-type epoxy compounds are epoxy compounds having two glycidyl ether groups obtained by reacting bisphenols with epichlorohydrin. This reaction generally involves oligomerization of diglycidyl ether compounds, and therefore contains epoxy compounds containing two or more bisphenol skeletons. Examples of bisphenols used in this reaction include bis(4-hydroxyphenyl)ketone, bis(4-hydroxy-3,5-dimethylphenyl)ketone, bis(4-hydroxy-3,5-dichlorophenyl)ketone, bis(4-hydroxyphenyl)sulfone, bis(4-hydroxy-3,5-dimethylphenyl)sulfone, bis(4-hydroxy-3,5-dichlorophenyl)sulfone, bis(4-hydroxyphenyl)hexafluoropropane, bis(4-hydroxy-3,5-dimethylphenyl)hexafluoropropane, bis(4-hydroxy-3,5-dimethylphenyl)hexafluoropropane, bis(4- hydroxy-3,5-dichlorophenyl)hexafluoropropane, bis(4-hydroxyphenyl)dimethylsilane, bis(4-hydroxy-3,5-dimethylphenyl)dimethylsilane, bis(4-hydroxy-3,5-dichlorophenyl)dimethylsilane, bis(4-hydroxyphenyl)methane, bis(4-hydroxy-3,5-dichlorophenyl)methane, bis(4-hydroxy-3,5-dibromophenyl)methane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl) Propane, 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3-chlorophenyl)propane, bis(4-hydroxyphenyl)ether, bis(4-hydroxy-3,5-dimethylphenyl)ether, bis(4-hydroxy-3,5-dichlorophenyl)ether, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-bromophenyl)fluorene, 9,9-bis(4-hydroxy-3-fluorophenyl)fluorene, 9,9-bis(4-hydroxy-3-methoxyphenyl)fluorene, 9,9-bis(4-hydroxy-3,5-dimethylphenyl)fluorene, 9,9-bis(4-hydroxy-3,5-dichlorophenyl)fluorene, 9,9-bis(4-hydroxy-3,5-dibromophenyl)fluorene, 4,4'-biphenol, 3,3'-biphenol, etc. Among these, bisphenols having a fluorene-9,9-diyl group are particularly preferred.

As the (I) dicarboxylic acid or tricarboxylic acid monoanhydride to be reacted with the epoxy (meth)acrylate, an acid monoanhydride of a chain hydrocarbon dicarboxylic acid or tricarboxylic acid, an acid monoanhydride of an alicyclic dicarboxylic acid or tricarboxylic acid, or an acid monoanhydride of an aromatic dicarboxylic acid or tricarboxylic acid, etc., is used. Here, examples of the acid monoanhydride of a chain hydrocarbon dicarboxylic acid or tricarboxylic acid include acid monoanhydrides of succinic acid, acetylsuccinic acid, maleic acid, adipic acid, itaconic acid, azelaic acid, citramalic acid, malonic acid, glutaric acid, citric acid, tartaric acid, oxoglutaric acid, pimelic acid, sebacic acid, suberic acid, diglycolic acid, etc., and also include those having any substituent introduced therein. Examples of monoanhydrides of alicyclic dicarboxylic or tricarboxylic acids include monoanhydrides of cyclobutanedicarboxylic acid, cyclopentanedicarboxylic acid, hexahydrophthalic acid, tetrahydrophthalic acid, norbornanedicarboxylic acid, etc., and also include those into which an arbitrary substituent has been introduced. Examples of monoanhydrides of aromatic dicarboxylic or tricarboxylic acids include monoanhydrides of phthalic acid, isophthalic acid, trimellitic acid, etc., and also include those into which an arbitrary substituent has been introduced.

As the tetracarboxylic acid dianhydride (II) to be reacted with the epoxy (meth)acrylate, a chain hydrocarbon tetracarboxylic acid dianhydride, an alicyclic tetracarboxylic acid dianhydride, or an aromatic tetracarboxylic acid dianhydride is used. Examples of the chain hydrocarbon tetracarboxylic acid dianhydride include butane tetracarboxylic acid, pentane tetracarboxylic acid, hexane tetracarboxylic acid, and other acid dianhydrides, and further include those having any substituent introduced therein. Examples of the alicyclic tetracarboxylic acid dianhydride include cyclobutane tetracarboxylic acid, cyclopentane tetracarboxylic acid, cyclohexane tetracarboxylic acid, cycloheptane tetracarboxylic acid, norbornane tetracarboxylic acid, and other acid dianhydrides, and further include those having any substituent introduced therein. Examples of the aromatic tetracarboxylic acid dianhydride include pyromellitic acid, benzophenone tetracarboxylic acid, biphenyl tetracarboxylic acid, biphenyl ether tetracarboxylic acid, and other acid dianhydrides, and further include those having any substituent introduced therein.

The molar ratio (I)/(II) of the dicarboxylic or tricarboxylic acid anhydride (I) and the tetracarboxylic acid dianhydride (II) to be reacted with the epoxy (meth)acrylate is preferably 0.01 to 10.0, and more preferably 0.02 or more and less than 3.0. If the molar ratio (I)/(II) deviates from the above range, it may not be possible to obtain an optimal molecular weight for obtaining a photosensitive resin composition with good photopatterning properties. Note that the smaller the molar ratio (I)/(II), the larger the molecular weight and the lower the alkali solubility.

Epoxy (meth)acrylate acid adducts can be produced by known methods, such as those described in JP-A-8-278629 and JP-A-2008-9401. First, an example of a method for reacting an epoxy compound with (meth)acrylic acid is to add an equimolar amount of (meth)acrylic acid to the epoxy group of the epoxy compound to a solvent, and react by heating and stirring at 90 to 120°C while blowing in air in the presence of a catalyst (triethylbenzylammonium chloride, 2,6-diisobutylphenol, etc.). Next, an example of a method for reacting an acid anhydride with the hydroxyl group of an epoxy acrylate compound, which is a reaction product, is to add a predetermined amount of an epoxy acrylate compound, an acid dianhydride, and an acid monoanhydride to a solvent, and react by heating and stirring at 90 to 130°C in the presence of a catalyst (tetraethylammonium bromide, triphenylphosphine, etc.). The epoxy acrylate acid adduct obtained by this method has a skeleton of general formula (1).

〔式（１）中、Ｒ₁、Ｒ₂、Ｒ₃及びＲ₄は、それぞれ独立して水素原子、炭素数１～５のアルキル基、ハロゲン原子又はフェニル基を表し、Ｒ₅は、水素原子又はメチル基を表し、Ａは、－ＣＯ－、－ＳＯ₂－、－Ｃ（ＣＦ₃）₂－、－Ｓｉ（ＣＨ₃）₂－、－ＣＨ₂－、－Ｃ（ＣＨ₃）₂－、－Ｏ－、フルオレン－９，９－ジイル基又は直結合を表し、Ｘ_１は４価のカルボン酸残基を表し、Ｙ_１及びＹ_２は、それぞれ独立して水素原子又は－ＯＣ－Ｚ－（ＣＯＯＨ）_m（但し、Ｚは２価又は３価カルボン酸残基を表し、ｍは１又は２の数を表す）を表し、ｎは１～２０の整数を表す。〕

[In formula (1), R ₁ , R ₂ , R ₃ and R ₄ each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom or a phenyl group; R ₅ represents a hydrogen atom or a methyl group; A represents -CO-, -SO ₂ -, -C(CF ₃ ) ₂ -, -Si(CH ₃ ) ₂ -, -CH ₂ -, -C(CH ₃ ) ₂ -, -O-, a fluorene-9,9-diyl group or a direct bond; X ₁ represents a tetravalent carboxylic acid residue; Y ₁ and Y ₂ each independently represent a hydrogen atom or -OC-Z-(COOH) _m (wherein Z represents a divalent or trivalent carboxylic acid residue and m represents the number 1 or 2); and n represents an integer of 1 to 20.]

Another preferred example of the polymerizable unsaturated group-containing alkali-soluble resin, which is the component (A), is a copolymer of (meth)acrylic acid, (meth)acrylic acid esters, etc., and includes a resin having a (meth)acrylic group and a carboxyl group. The above resin is, for example, a polymerizable unsaturated group-containing alkali-soluble resin obtained by reacting a copolymer obtained by copolymerizing (meth)acrylic acid esters containing glycidyl (meth)acrylate in a solvent in the first step with the copolymer obtained, in the second step, with (meth)acrylic acid, and in the third step with an anhydride of a dicarboxylic acid or tricarboxylic acid. For examples of these copolymers that can be preferably used, refer to those specifically shown in Japanese Patent Application No. 2017-33662. As another method for obtaining such a resin (copolymer) having a (meth)acrylic group and a carboxyl group, it is also possible to react a copolymer obtained by copolymerizing (meth)acrylic acid and (meth)acrylic acid esters in a solvent in the first step with glycidyl (meth)acrylate in the second step, and in the third step with an anhydride of a dicarboxylic acid or tricarboxylic acid.

Another example includes a urethane compound obtained by reacting a polyol compound having an ethylenically unsaturated bond in the molecule as the first component, a diol compound having a carboxyl group in the molecule as the second component, and a diisocyanate compound as the third component. As examples of resins of this type, those shown in JP 2017-76071 A can be referred to.

In the present invention, among these (A) components, it is preferable to use the epoxy (meth)acrylate acid adduct shown as the first example, and more preferably, the one shown in the above general formula (1).

<(B) Photopolymerizable monomer having at least two ethylenically unsaturated bonds>
Examples of the photopolymerizable monomer having at least two ethylenically unsaturated bonds in the component (B) include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tetramethylene glycol di(meth)acrylate, glycerol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra ... Examples of the photopolymerizable monomer include (meth)acrylic acid esters such as glycerol tri(meth)acrylate, sorbitol penta(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, sorbitol hexa(meth)acrylate, alkylene oxide modified hexa(meth)acrylate of phosphazene, and caprolactone modified dipentaerythritol hexa(meth)acrylate, and dendritic polymers having a (meth)acrylic group as a compound having an ethylenic double bond. Only one of these monomers may be used alone, or two or more may be used in combination. In addition, the photopolymerizable monomer can play a role of crosslinking the molecules of the alkali-soluble resin containing a polymerizable unsaturated group, and in order to exert this function, it is preferable to use one having three or more ethylenic double bonds. Furthermore, the acrylic equivalent, calculated by dividing the molecular weight of the monomer by the number of (meth)acrylic groups in one molecule, is preferably from 50 to 300, and more preferably from 80 to 200. The component (B) does not have a free carboxy group.

An example of a dendritic polymer having a (meth)acrylic group as a compound having an ethylenic double bond is a dendritic polymer obtained by adding a polyvalent mercapto compound to a part of the carbon-carbon double bond in the (meth)acrylate group of a polyfunctional (meth)acrylate compound. Specifically, it includes a dendritic polymer obtained by reacting the (meth)acrylate of a polyfunctional (meth)acrylate compound of general formula (2) with a polyvalent mercapto compound of general formula (3).

Here, R ₆ represents a hydrogen atom or a methyl group, R ₇ represents the remaining portion of R ₈ (OH) _p where one of the p hydroxyl groups is donated to the ester bond in the formula, and preferred R ₈ (OH) _p is a polyhydric alcohol based on a non-aromatic straight or branched hydrocarbon skeleton having 2 to 8 carbon atoms, a polyhydric alcohol ether formed by linking multiple molecules of the polyhydric alcohol via ether bonds by dehydration condensation of the alcohol, or an ester of such a polyhydric alcohol or polyhydric alcohol ether with a hydroxy acid. p and q independently represent integers of 2 to 20, provided that p≧q.

Here, R ₉ is a single bond or a divalent to hexavalent C1 to C6 hydrocarbon group, r is 2 when R ₉ is a single bond, and r is an integer from 2 to 6 when R ₉ is a divalent to hexavalent group.

Specific examples of polyfunctional (meth)acrylate compounds represented by general formula (2) include (meth)acrylic acid esters such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethylene oxide modified trimethylolpropane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and caprolactone modified pentaerythritol tri(meth)acrylate. These compounds may be used alone or in combination of two or more.

Specific examples of polyvalent mercapto compounds represented by general formula (3) include trimethylolpropane tri(mercaptoacetate), trimethylolpropane tri(mercaptopropionate), pentaerythritol tetra(mercaptoacetate), pentaerythritol tri(mercaptoacetate), pentaerythritol tetra(mercaptopropionate), dipentaerythritol hexa(mercaptoacetate), dipentaerythritol hexa(mercaptopropionate), etc. These compounds may be used alone or in combination of two or more.

Here, the blending ratio of the above-mentioned (A) and (B) components [(A)/(B)] is preferably 20/80 to 90/10, and more preferably 40/60 to 70/30. Here, if the blending ratio of the (A) component is low, the cured product after the photocuring reaction becomes brittle, and the acid value of the coating film in the unexposed areas is low, so that the solubility in an alkaline developer decreases, resulting in problems such as the pattern edges becoming loose and not sharp. Conversely, if the blending ratio of the (A) component is higher than the above range, the proportion of photoreactive functional groups in the photoreactive components ((A) component + (B) component) is low, and the formation of a crosslinked structure by the photocuring reaction may not be sufficient.

<(C) Epoxy Compound>
The epoxy compound of component (C) in the present invention is a siloxane epoxy resin having a siloxane-derived structure shown below.
Here, the chemical shifts of the silicon-containing bonding units T and D in the ²⁹ Si-NMR spectrum are observed in the ranges of -45 ppm to -80 ppm for T units and 0 ppm to -40 ppm for D units, whereas in the epoxy compound of component (C) of the present invention, the T units show signals in the ranges of -47 ppm to -52 ppm, -55 ppm to -61 ppm, and -62 ppm to -72 ppm, respectively, which represent the signals derived from the silicon-containing bonding units of the following structures T1 (-47 ppm to -52 ppm), T2 (-55 ppm to -61 ppm), and T3 (-62 ppm to -72 ppm), respectively.

〔但し、Ｒは水素基、メチル基、エチル基、フェニル基であり、Ｘは、次の(a)又は(b)であって、同一であっても異なっていてもよいが、各構造において少なくとも１つのＸは(a)である。このＸについては後述する。
(a)３，４－エポキシシクロヘキシル基、又は、炭素数１～６の有機基の末端に３，４－エポキシシクロヘキシル基を有する基
(b)炭素数１～６の有機基〕

(wherein R is a hydrogen group, a methyl group, an ethyl group, or a phenyl group, and X is the following (a) or (b), which may be the same or different, but at least one X in each structure is (a). This X will be described later.
(a) a 3,4-epoxycyclohexyl group, or a group having a 3,4-epoxycyclohexyl group at the terminal of an organic group having 1 to 6 carbon atoms
(b) an organic group having 1 to 6 carbon atoms]

This component (C) is characterized by containing the above-mentioned T2 and T1 structures in addition to the signal indicating the T3 structure that can be observed in general siloxane resins. By having such T2 and T1 structures in addition to the T3 structure, it is possible to provide the heat resistance and chemical resistance derived from the T3 structure, and to improve solubility in organic solvents and compatibility when used in combination with other resins, making it possible to widely design the required properties of the cured product and to apply it to various processing processes using tourist resin compositions. And, for these structures T1 to T3, the area ratio of the signals is preferably T1:T2:T3=0-1:1-10:1-100, preferably 0-1:1-10:1-50.

〔構造Ｄ１～Ｄ２中、Ｒは水素基、メチル基、エチル基又はフェニル基であり、Ｙは、前記の(a)又は(b)であって、各構造において同一であっても異なっていてもよい。〕 Furthermore, in addition to the above T structure, the component (C) preferably contains the following structure D1, which shows a signal at -9 ppm to -13 ppm in the ²⁹ Si-NMR spectrum, and the following structure D2, which shows a signal at -15 ppm to -24 ppm in the 29 Si-NMR spectrum. By having such specific D1 and D2 structures, it is preferable in that the compatibility with organic solvents and other epoxy resins and the like is improved.

[In structures D1 and D2, R is a hydrogen group, a methyl group, an ethyl group, or a phenyl group, and Y is either (a) or (b) as defined above, and may be the same or different in each structure.]

Furthermore, the area ratio of the signals of the T structure and the D structure is preferably (T1+T2+T3):(D1+D2)=10-1:5-0. From the viewpoint of low moisture absorption of the cured product, it is more preferable that (T1+T2+T3):(D1+D2)=10-1:2-0. For example, if there is a need to improve heat resistance (low gas generation), it is necessary to design the siloxane resin so that a large amount of T structures is introduced. Also, for example, if there is a need to control the physical properties of the cured product and improve compatibility with other epoxy resins, etc., it is necessary to design a siloxane resin that contains a certain amount of D structures.

A representative structure of the component (C) is one having a group represented by the following formula (4) or (5) in the molecule.

In the above formulas (4) and (5), j, k, s, and t are
1≦j+k≦7 (j≧0, k≧1) ... (i)
2≦s+t≦100 (s≧1, t≧1) ... (ii)
Here, j+k is preferably 1 or more from the viewpoint of compatibility with other compounds, while it is preferably 7 or less from the viewpoint of chemical resistance and adhesion of the coating film. That is, it is preferable that there is a cyclic structure of an appropriate size that can satisfy such characteristics. j+k is more preferably 1 to 6, and even more preferably 1 to 4. Also, s+t is preferably 2 to 100 from the viewpoint of molecular weight control and compatibility with other compounds. That is, it is preferable that the compound has a cyclic structure and a chain structure bonded at an appropriate ratio, and this s+t is more preferably 2 to 99, and even more preferably 3 to 75. * represents a bond, and when linked, forms a Si-O-Si bond.

X in formula (4) and formula (5) is (a) or (b) as described above, and may be the same or different, but contains one or more (a). (a) may be present anywhere in X in the T structure or Y in the D structure, but it is preferable that (a) exists multiple times and exists in both the T structure and the D structure.

In the above group having a 3,4-epoxycyclohexyl group at the end of an organic group having 1 to 6 carbon atoms, the "organic group having 1 to 6 carbon atoms" may include an alkyl group, a cycloalkyl group, a phenyl group, etc., which may be branched. The number of carbon atoms is preferably 1 to 4, and more preferably 1 to 3. Examples of such organic groups include alkyl groups such as a methyl group, an ethyl group, various propyl groups, various butyl groups, and cycloalkyl groups such as a cyclopropyl group. Note that "various" refers to various isomers including n-, sec-, tert-, and iso-.

When X in formula (4) and formula (5) is a hydrocarbon group having 1 to 3 carbon atoms, preferred examples are a methyl group and an ethyl group.

Multiple X's may be the same or different, but from the viewpoint of curability, it is preferable that at least one of them contains a 3,4-epoxycyclohexyl group, and that the organic group having 1 to 6 carbon atoms contains a group having a 3,4-epoxycyclohexyl group at the end thereof, and more preferably, the amount of groups having a 3,4-epoxycyclohexyl group at the end thereof, relative to 100 mol % of Si, is 15 mol % or more, more preferably 30 mol % or more. As the group having a 3,4-epoxycyclohexyl group at the end thereof, a β-(3,4-epoxycyclohexyl)ethyl group is preferable.

ここで、式（６）中のＲ_Ｘは、水酸基、炭素数１～３の炭化水素基、フェニル基、メトキシ基、又はエトキシ基であり、Ｘは、前記した(a)又は(b)である。＊は結合手を表し、連結する場合はSi-O-Si結合を構成し、繰り返し単位が０～１５０００であることが好ましい。 On the other hand, R' in formula (4) and formula (5) is a hydroxyl group, a hydrocarbon group having 1 to 3 carbon atoms, a phenyl group, a methoxy group, an ethoxy group, or a group represented by the following formula (6).

In the formula (6), R _X is a hydroxyl group, a hydrocarbon group having 1 to 3 carbon atoms, a phenyl group, a methoxy group, or an ethoxy group, and X is the above-mentioned (a) or (b). * represents a bond, and when linked, forms a Si-O-Si bond, and it is preferable that the number of repeating units is 0 to 15,000.

R' in formulas (4) and (5) may be the same or different, but if all R' are hydroxyl groups, the storage stability will be poor and, depending on the compounding composition, the low moisture absorption of the cured film may be impaired. Therefore, it is preferable that the content of hydroxyl groups is 30 mol % or less relative to 100 mol % of Si, and more preferably, it is a group other than hydroxyl groups.

Of the above R' and R _X , the hydrocarbon group having 1 to 3 carbon atoms is preferably a methyl group or an ethyl group, which provides a cured film with high heat resistance.

The weight average molecular weight of this component (C) is 750 to 20,000, and the epoxy equivalent is less than 350 g/eq.

The weight average molecular weight is expressed as the weight average molecular weight (Mw) converted into polystyrene by gel permeation chromatography (GPC). If the Mw is below 750, the resulting film (cured product) will have a low crosslink density and poor chemical resistance, and will tend to remain in the coating film as unreacted matter, causing the coating film to have poor degassing properties. If the Mw is greater than 20,000, the resulting film (cured product) will tend to have poor flatness and poor compatibility with other compounds. It is preferable that the Mw is between 1,000 and 15,000.

In addition, if the epoxy equivalent is 350 g/eq or more, the reactive group content decreases, resulting in insufficient curing and a tendency for the crosslinking density to be low, which deteriorates the properties of the cured film, such as chemical resistance. It is preferable that the molecular weight is 150 or more and less than 350.

The photosensitive resin composition of the present invention, by containing the above-mentioned component (C), can obtain a cured film with low moisture absorption. Although the details of the reason for this are unclear, it is speculated that the reason is that the epoxy groups of conventional general siloxane epoxy resins are structural units derived from highly hydrophilic glycidyl, whereas siloxane epoxy resins containing 3,4-epoxycyclohexyl groups are highly hydrophobic cyclohexyl epoxy groups. Furthermore, it is speculated that the reason is that conventional general siloxane epoxy resins, when produced by hydrolysis condensation or the like, tend to generate or remain silanol groups [groups showing hydroxyl groups in R' in the above formulas (4) and (5)], whereas the siloxane epoxy resins of the present invention containing 3,4-epoxycyclohexyl groups have fewer silanol groups.

The component (C) can be produced, for example, by the following method (c) or (d).
(c) A method of obtaining an alkoxysilane compound having a specific organic group or a mixture of an alkoxysilane having a specific organic group and another silane compound by hydrolysis and polycondensation in the presence of a suitable organic solvent, acid and water,
(d) The polysiloxane having a hydrosilane structure can be produced by a known method such as adding a compound having a specific organic group and a double bond group to the polysiloxane having a hydrosilane structure. However, the method (c) is preferred because it is common and easy.

In the case of producing by the method (c), trialkoxysilane represented by the general formula Si(X ¹ )(OR ₁₀ ) ₃ is used as the alkoxysilane compound, and this trialkoxysilane is hydrolyzed or hydrolyzed and condensed, or this Si(X ¹ )(OR ₁₀ ) ₃ is hydrolyzed or hydrolyzed and condensed with dialkoxysilane represented by the general formula Si(X ² ) ₂ (OR ₁₁ ) _2. However, X ¹ is a group shown in (a) or (b) above, and may be the same or different, but at least one of them includes (a), and among (a), it is preferable that it contains a group having a 3,4-epoxycyclohexyl group at the end of an organic group having 1 to 6 carbon atoms. X ² is a group shown in (a) or (b) above, and may be the same or different, but at least one of them has a group shown in (b). R ₁₀ and R ₁₁ are each independently an alkyl group or a phenyl group having 1 to 3 carbon atoms.

For such a reaction, it is preferable to carry out hydrolysis and condensation under acidic conditions, for example. Organic or inorganic acids such as hydrogen fluoride, hydrochloric acid, nitric acid, formic acid, propionic acid, oxalic acid, citric acid, maleic acid, benzoic acid, malonic acid, glutaric acid, glycolic acid, methanesulfonic acid, and toluenesulfonic acid can be used. The presence of water is necessary for hydrolysis and the amount of water should be sufficient to hydrolyze the hydrolyzable groups of the silane compound, but it is preferable to add water in an amount of 0.3 to 1.5 times the number of hydrolyzable groups (theoretical amount).

The above trialkoxysilanes include methyltrimethoxysilane, methyltriethoxysilane, methyltrippropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrippropoxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltrippropoxysilane, isobutyltrimethoxysilane, n-hexyltriethoxysilane, n-octyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltrippropoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltriethoxysilane, 3-acryloxypropyltriethoxysilane, Examples of trialkoxysilane include alkoxysilanes such as oxysilane, p-styryltrimethoxysilane, p-styryltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 8-octenyltrimethoxysilane, 8-glycidoxyoctyltrimethoxysilane, 8-methacryloxyoctyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltripropoxysilane, 3,4-epoxycyclohexylmethyltrimethoxysilane, 3,4-epoxycyclohexylmethyltrimethoxysilane, and 2-(3,4-epoxycyclohexyl)methyltripropoxysilane. Among these, it is preferable to use a trialkoxysilane having a 3,4-epoxycyclohexyl group.

Examples of the dialkoxysilane include dimethyldimethoxysilane, diethyldiethoxysilane, phenylmethyldimethoxysilane, diphenyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, cyclohexylmethyldimethoxysilane, vinylmethyldiethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethylmethyldimethoxysilane, Examples of the silane compounds include dialkoxysilane compounds such as 2-(3,4-epoxycyclohexyl)ethylmethyldipropoxysilane, 2-(3,4-epoxycyclohexyl)diethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)diethyldiethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldipropoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyldipropoxysilane, ethylmethyldimethoxysilane, ethylmethyldiethoxysilane, ethylmethyldipropoxysilane, 3-methacryloxypropylmethyldimethoxysilane, and 3-methacryloxypropylmethyldiethoxysilane.
These trialkoxy or dialkoxy silane compounds can be used alone or in combination of two or more.

In the present invention, the content of the above component (C) in the solid content of the photosensitive resin composition is preferably 3% by mass or more, more preferably 5% by mass or more. If it is within the above range, the low moisture absorption of the cured product will be sufficiently high. On the other hand, the upper limit is preferably 25% by mass or less, more preferably 20% by mass or less.

<(D) Photopolymerization initiator>
Examples of the photopolymerization initiator (D) include acetophenones such as acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, and p-tert-butylacetophenone; benzophenones such as benzophenone, 2-chlorobenzophenone, and p,p'-bisdimethylaminobenzophenone; benzoin ethers such as benzyl, benzoin, benzoin methyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; α-aminoalkylphenones such as 2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropan-1-one and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1; 2-(o-chlorophenyl)-4,5-phenylbiimidazole, 2-(o-chlorophenyl)-4,5-phenylbiimidazole, biimidazole compounds such as 2-(o-chlorophenyl)-4,5-diphenylbiimidazole, 2-(o-methoxyphenyl)-4,5-diphenylbiimidazole, 2-(o-methoxyphenyl)-4,5-diphenylbiimidazole, and 2,4,5-triarylbiimidazole; 2-trichloromethyl-5-styryl-1,3,4-oxadiazole, 2-trichloromethyl-5-(p-cyanostyryl)-1,3, halomethylthiazole compounds such as 4-oxadiazole and 2-trichloromethyl-5-(p-methoxystyryl)-1,3,4-oxadiazole; 2,4,6-tris(trichloromethyl)-1,3,5-triazine, 2-methyl-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-phenyl-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-chlorophenyl)-4,6-bis (trichloromethyl)-1,3,5-triazine, 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(3,4,5-trimethoxystyryl)-4,6-bis(trichloromethyl) halomethyl-S-triazine compounds such as 2-(4-methylthiostyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine; 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(O-benzoyloxime), 1-(4-phenylsulfanylphenyl)butane-1,2-dione-2-oxime-O-benzoate, 1-(4-methylsulfanylphenyl)butane-1,2-dione-2-oxime-O-benzoate, 1-(4-methylsulfanylphenyl)butane-1,2-dione-2-oxime-O-benzoate, O-acyloxime compounds such as 1-(4-methylsulfanylphenyl)butane-1-one oxime-O-acetate and 1-(4-methylsulfanylphenyl)butan-1-one oxime-O-acetate; sulfur compounds such as benzyl dimethyl ketal, thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2-methylthioxanthone, and 2-isopropylthioxanthone; anthraquinones such as 2-ethylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, and 2,3-diphenylanthraquinone; organic peroxides such as azobisisobutylnitrile, benzoyl peroxide, and cumene peroxide, thiol compounds such as 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, and 2-mercaptobenzothiazole; and tertiary amines such as triethanolamine and triethylamine. Among these, O-acyloxime compounds (including ketoximes) are preferred, particularly when a photosensitive resin composition containing a colorant is to be prepared. These photopolymerization initiators may be used alone or in combination of two or more. The photopolymerization initiator of the present invention contains a sensitizer.

In the photosensitive resin composition of the present invention, the photopolymerization initiator (D) is preferably 0.1 to 10 parts by mass, and more preferably 1 to 5 parts by mass, per 100 parts by mass of the total of the components (A) and (B). If it is less than 0.1 part by mass, sufficient sensitivity cannot be obtained, and if it exceeds 10 parts by mass, halation is likely to occur in which the tapered shape (the shape in the film thickness direction of the cross section of the developed pattern) becomes weak and has a trailing edge, and decomposition gas may be generated when exposed to high temperatures in a later process.

<(E) Non-siloxane type compound>
The photosensitive resin composition of the present invention may further contain a non-siloxane type compound that does not contain a siloxane structure. Such a non-siloxane type compound may be used without particular limitation as long as it is compatible with the above-mentioned siloxane resin, and is preferable because it can further improve properties such as flatness and hardness and adjust viscosity by containing it. As such a non-siloxane type compound, a compound that does not contain a siloxane skeleton and has an epoxy group or a polymerizable unsaturated bond is used. Among these compounds, a compound that is liquid at room temperature or solid at room temperature may be used without particular limitation as long as it can be uniformly mixed with the addition of a solvent. Specific compounds are exemplified below.

Examples will be given starting from compounds that do not contain a siloxane skeleton and have an epoxy group.
Examples of the chain aliphatic epoxy compounds that are liquid at room temperature include trimethylolpropane triglycidyl ether, trimethylolethane triglycidyl ether, mono- or diglycidyl ether of branched alkyl ester, FOLDI series manufactured by Nissan Chemical Industries, etc. Such chain aliphatic epoxy compounds contribute to improving heat resistance by improving crosslink density through reaction with a curing agent. In particular, epoxy compounds with a viscosity of 30 to 500 mPa·s (25°C) can be preferably used.

Also, examples of alicyclic epoxy compounds that are liquid at room temperature include (3',4'-epoxycyclohexylmethyl) 3,4-epoxycyclohexanecarboxylate, 2-(3,4-epoxy)cyclohexyl-5,1-spiro(3,4-epoxy)cyclohexyl-m-dioxane, bis(3,4-epoxycyclohexylmethyl)adipate, hydrogenated bisphenol A diglycidyl ether, and 1,4-cyclohexanedimethanol-bis 3,4-epoxycyclohexanecarboxylate. Epoxy compounds with a viscosity of 50 to 3500 mPa·s (25°C) can be preferably used.

Examples of aromatic epoxy compounds that are liquid at room temperature include low molecular weight compounds such as bisphenol A type epoxy compounds and bisphenol F type epoxy compounds.

Examples of epoxy compounds having a triazine skeleton that are liquid at room temperature include polyfunctional epoxy compounds having a triazine skeleton (manufactured by Nissan Chemical Industries, Ltd., TEPIC-PAS, TEPIC-VL, TEPIC-UC, etc.).

Among these epoxy compounds that are liquid at room temperature, low molecular weight liquid compounds such as (3',4'-epoxycyclohexylmethyl) 3,4-epoxycyclohexanecarboxylate and bisphenol A type epoxy resins can be more preferably used.

The use of these liquid epoxy resins can further improve the flatness of the film (cured product).

On the other hand, examples of epoxy compounds that are solid at room temperature include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, phenol novolac type epoxy compounds, cresol novolac type epoxy compounds, glycidyl ethers of polyhydric alcohols, glycidyl esters of polycarboxylic acids, alicyclic epoxy compounds such as 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol (e.g., Daicel Corporation's "EHPE3150"), copolymers of (meth)acrylic acid esters containing glycidyl (meth)acrylate as an essential component, epoxidized polybutadiene (e.g., Nippon Soda Co., Ltd.'s "NISSO-PB JP-100"), and trifunctional epoxy compounds having a triazine skeleton (Nissan Chemical Industries, Ltd.'s TEPICSC-G, S, SS, SP, etc.), and other known epoxy compounds that are solid at room temperature can be used without particular restriction. In addition, epoxy compounds that are waxy or granular at room temperature and have a low melting point, such as ε-caprolactam modified (3',4'-epoxycyclohexylmethyl) 3,4-epoxycyclohexanecarboxylate (TTA2081, TTA2083, manufactured by Tetrachem), can also be used.

Among these, the copolymer of two or more (meth)acrylic acid esters containing glycidyl (meth)acrylate as an essential component is, for example, a compound obtained by radical copolymerization of glycidyl (meth)acrylate with (meth)acrylic esters and other polymerizable unsaturated compounds by a conventional method. In the above radical copolymerization, a known radical polymerization initiator such as an azo compound or a peroxide can be used. In addition, the degree of polymerization may be controlled so that the weight average molecular weight is 900 to 20,000 by using a known chain transfer agent or polymerization inhibitor.

Examples of (meth)acrylic esters other than glycidyl (meth)acrylate and other polymerizable unsaturated compounds used in the above copolymer are given below, but are not limited to these.

(Meth)acrylic acid esters can be obtained by a condensation reaction between (meth)acrylic acid ((meth)acrylic acid refers to acrylic acid or methacrylic acid) and an alcohol (R ¹ OH) component. As the (R ¹ OH) component, any known compound can be used without any particular limitation. Specific examples of R ¹ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a hexyl group, a heptyl group, an octyl group, a 2-ethylhexyl group, a nonyl group, a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group, an octadecyl group, an icosyl group, a cyclopropyl group, a cyclopentyl group, a cyclopentylethyl group, a cyclohexyl group, a cyclohexylmethyl group, a 4-methylcyclohexyl group, an adamantyl group, an isobornyl group, a dicyclopentamethyl group, a cyclopentyl ... Examples of the alkyl group include saturated or unsaturated monovalent hydrocarbon groups such as a pyridyl group, a piperidyl group, a piperidino group, a pyrrolyl group, a pyrrolidinyl group, an imidazolyl group, an imidazolidinyl group, a furyl group, a tetrahydrofuryl group, a thienyl group, a tetrahydrothienyl group, a morpholinyl group, a morpholino group, and a quinolyl group. The above-mentioned hydrocarbon group or heterocyclic group may have a structure in which a halogen atom, a carbonyl group, a thiocarbonyl group, a nitro group, a silyl group, an ether group, a thioether group, an ester group, a thioester group, a dithioester group, a urethane group, a thiourethane group, a ureido group, a thioureido group, or the like is introduced as a substituent at any position. Such a monovalent group may be appropriately selected depending on the structure of the desired (meth)acrylic acid ester copolymer, but from the viewpoint of performance and economy, it is preferably a saturated or unsaturated monovalent hydrocarbon group having 1 to 20 carbon atoms, and more preferably a saturated or unsaturated monovalent hydrocarbon group having 1 to 6 carbon atoms. The saturated or unsaturated monovalent hydrocarbon group may be a hydrocarbon group having a branched structure or a ring structure, and may further be substituted with any substituent. However, it is preferable that the above-mentioned substituent does not have a reactive structure such as an acidic group or an amide bond.

Other polymerizable unsaturated compounds include styrene and its derivatives. Specific compounds that can be used include styrene, α-methylstyrene, and compounds in which an alkyl group, a halogen atom, a hydroxyl group, etc. is introduced into the aromatic ring of styrene.

In addition to the above, epoxy group-containing polymerizable unsaturated compounds other than glycidyl methacrylate (e.g., glycidyl acrylate, (meth)acrylate [4-(glycidyloxy)butyl], (meth)acrylate [(3,4-epoxycyclohexyl)methyl], and 4-(glycidyloxymethyl)styrene, etc.), as well as alkoxysilyl group-containing polymerizable unsaturated compounds (e.g., (meth)acrylate [3-(trimethoxysilyl)propyl], (meth)acrylate [3-(triethoxysilyl)propyl], and 4-(trimethoxysilyl)styrene, etc.) may also be copolymerized.

Among the copolymers listed above, preferred examples include copolymers of glycidyl methacrylate, alkyl methacrylate esters (C1-C4 alkyl groups), and copolymers of styrene, which have a softening point (Tg) of 10-90°C. The more preferred range for the Tg of the copolymer is 40-90°C.

Among the epoxy compounds that are solid at room temperature, those that are particularly suitable for further improving heat resistance and low gas generation are those represented by the following general formula (7) in which the average value of l is 0 to 2.

In general formula (7), Ar is a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. In addition, some of the hydrogen atoms of the divalent aromatic hydrocarbon group represented by Ar may be substituted with a hydrocarbon group having 1 to 10 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a halogen group.

The epoxy compound of general formula (7) can be a bisphenolfluorene type epoxy compound or a bisnaphtholfluorene type epoxy compound. This epoxy compound has a relatively small effect on the viscosity of the curable resin composition and is an effective component for imparting low gas generation and heat resistance. In particular, for imparting low gas generation, a bisnaphtholfluorene type epoxy resin is more preferable.

In general formula (7), l may have an average value of 0 to 2. If it is 0 or more, the solubility can be increased, and if it exceeds 2, it tends to affect the curability of the cured film. The average value of l is preferably 0.01 to 1. The average value of l can be calculated from the epoxy equivalent, and for example, in the case of a bisnaphtholfluorene type epoxy compound,
(Epoxy equivalent) x 2 = (average value of l) x 506.6 + 562.7
In the case of a bisphenol fluorene type epoxy compound, the following can be calculated:
(Epoxy equivalent) x 2 = (average value of l) x 406.5 + 462.5
It can be calculated from:

The epoxy compound of general formula (7) can be synthesized by known methods such as the method described in JP-A-9-328534, but the most common and preferred method is to condense 9,9-bis(4-hydroxyphenyl)fluorene or 9,9-bis(4-hydroxynaphthyl)fluorene with epichlorohydrin in the presence of an alkali. The value of l can be adjusted to the desired value by adjusting the molar ratio of the raw material compounds during synthesis or by adjusting the reaction conditions.

Next, as the component (E), a compound having a polymerizable unsaturated bond that does not contain a siloxane skeleton is exemplified. An epoxy acrylate compound obtained by reacting the above-exemplified epoxy compound not containing a siloxane skeleton with a monocarboxylic acid compound having a polymerizable unsaturated bond, such as acrylic acid or methacrylic acid, can be used without any particular restrictions, as long as it can be mixed uniformly with the addition of a solvent. Other examples of monocarboxylic acid compounds having a polymerizable unsaturated bond, where (meth)acrylate represents acrylate or methacrylate, include half esters of 2-hydroxyethyl (meth)acrylate and succinic anhydride, half esters of 2-hydroxyethyl (meth)acrylate and phthalic anhydride, half esters of 2-hydroxyethyl (meth)acrylate and cyclohexane-1,2-dicarboxylic anhydride, and 4-vinylbenzoic acid. In addition, a polymerizable monomer having a polymerizable unsaturated bond can also be used without any particular restrictions, as long as it can be mixed uniformly with the addition of a solvent.

Examples of polymerizable monomers include (meth)acrylic acid esters having a hydroxyl group, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate; ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tetramethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol di(meth)acrylate, and ethylene glycol di(meth)acrylate. Examples of (meth)acrylic acid esters include taerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, glycerol (meth)acrylate, sorbitol penta(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, sorbitol hexa(meth)acrylate, alkylene oxide-modified hexa(meth)acrylate of phosphazene, and caprolactone-modified dipentaerythritol hexa(meth)acrylate. One or more of these can be used.

In the present invention, the non-siloxane type compound is preferably contained in an amount of 3% by mass or more, more preferably 5% by mass or more. On the other hand, the upper limit is preferably 20% by mass or less, more preferably 15% by mass or less. Within the above range, it is possible to improve flatness and pattern linearity without impairing the moisture absorption, pattern adhesion, and pattern definition of the cured product.

＜Other ingredients＞

The photosensitive resin composition of the present invention may contain other optional components as necessary, such as coloring materials, fillers, resins, additives, etc. Examples of coloring materials include dyes, organic pigments, inorganic pigments, carbon black pigments, etc.; fillers include silica, talc, etc.; resins include vinyl resins, polyester resins, polyamide resins, polyimide resins, polyurethane resins, polyether resins, melamine resins, etc.; and additives include dispersants, surfactants, silane coupling agents, viscosity modifiers, wetting agents, defoamers, antioxidants, ultraviolet absorbers, thermal radical initiators, etc. Known compounds can be used as these optional components without any particular restrictions.

Examples of coupling agents that can be used include silane coupling agents (such as 3-(glycidyloxy)propyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, and 3-ureidopropyltriethoxysilane), titanium-based coupling agents, and aluminum-based coupling agents. Examples of thermal radical initiators include azo-based initiators such as 2,2-azobisisobutyronitrile, dimethyl 2,2-azobis 2-methylpropionate, and 1,1'-azobis(1-acetoxy-1-phenylethane), and peroxides such as benzoyl peroxide.

When used as a protective film for a color filter, surfactants (fluorine-based surfactants, silicone-based surfactants, etc.) may be used. As the surfactant, known surfactants such as silicone-based and fluorine-based surfactants can be used without any particular limitation. Examples of silicone-based surfactants include side-chain modified polydimethylsiloxane, both-end modified polydimethylsiloxane, one-end modified polydimethylsiloxane, and both-end modified polydimethylsiloxane. Examples of fluorine-based surfactants include perfluoroalkyl sulfonic acid compounds, perfluoroalkyl carboxylic acid compounds, perfluoroalkyl phosphate ester compounds, perfluoroalkyl ethylene oxide adducts, and polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups on the side chain. In addition, only one of these surfactants may be used alone, or two or more of them may be used in combination. The amount of surfactant added can be adjusted depending on the surface tension of the photosensitive resin composition, and the range of the amount added is 0.001 to 0.1 mass% in the photosensitive resin composition. The range of the amount added also varies depending on the type of surfactant, and is usually in the range of 0.001 to 0.01 mass% for silicone-based surfactants and 0.01 to 0.1 mass% for fluorine-based surfactants.

In addition, known compounds can be used as the solvent. For example, ester-based solvents (butyl acetate, cyclohexyl acetate, etc.), ketone-based solvents (methyl isobutyl ketone, cyclohexanone, etc.), ether-based solvents (diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, etc.), alcohol-based solvents (3-methoxybutanol, ethylene glycol mono-t-butyl ether, etc.), aromatic solvents (toluene, xylene, etc.), aliphatic solvents, amine-based solvents, and amide-based solvents can be used without particular restrictions. From the viewpoint of safety, ester-based and ether-based solvents having a propylene glycol skeleton, such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene glycol diacetate are preferred. Also preferred are 3-methoxybutyl acetate, 3-methoxy-3-methylbutyl acetate, and 1,3-butylene glycol diacetate, which have a similar structure.

In addition, in the photosensitive resin composition of the present invention, if necessary, a curing agent for an epoxy compound selected from the group consisting of polycarboxylic acids, anhydrides of polycarboxylic acids, and thermally decomposable esters of polycarboxylic acids, a curing accelerator for an epoxy compound, a curing catalyst, a latent curing agent, or other known curing-accelerating compounds can be used. When a curing agent is used, it is preferable to mix it in an amount of 1 to 20 mass% based on the total mass of the solid content of the composition, and more preferably to mix it in an amount of 5 to 10 mass%. If it is less than 1 mass%, it is poorly effective as a curing agent, and if it exceeds 20 mass%, the excess curing agent that does not contribute to curing has a negative effect on gas generation. In addition, when a compound that accelerates curing is used, it is preferable to mix it in an amount of 0.005 to 2 mass% based on the total mass of the solid content of the composition, and more preferably to mix it in an amount of 0.01 to 1 mass%. If it is less than 0.005 mass%, it is poorly effective as an accelerator, and if it exceeds 2 mass%, sufficient storage stability cannot be obtained when the curable resin composition is made into a solution, or coloring during heating is adversely affected.

The polyvalent carboxylic acid used as the curing agent is a compound having two or more carboxy groups in one molecule, such as succinic acid, maleic acid, cyclohexane-1,2-dicarboxylic acid, cyclohexene-1,2-dicarboxylic acid, cyclohexene-4,5-dicarboxylic acid, norbornane-2,3-dicarboxylic acid, phthalic acid, benzene-1,2,4-tricarboxylic acid, cyclohexane-1,2,4-tricarboxylic acid, benzene-1,2,4,5-tetracarboxylic acid, cyclohexane-1,2,4,5-tetracarboxylic acid, and butane-1,2,3,4-tetracarboxylic acid.

In addition, examples of polycarboxylic acid anhydrides that can be used as curing agents include the acid anhydrides of the polycarboxylic acids exemplified above. These may be intermolecular acid anhydrides, but acid anhydrides that are ring-closed within a molecule are generally used. An example of a preferred acid anhydride is trimellitic anhydride.

Furthermore, examples of the thermally decomposable esters of polycarboxylic acids as curing agents include t-butyl esters, 1-(alkyloxy)ethyl esters, and 1-(alkylsulfanyl)ethyl esters of the above-listed polycarboxylic acids (wherein alkyl represents a saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms, and such a hydrocarbon group may have a branched or cyclic structure, and may be substituted with any substituent).

As the curing agent, a polymer or copolymer having two or more carboxy groups can also be used. The carboxy groups of the polymer or copolymer may be an anhydride or a thermally decomposable ester. Examples of such polymers or copolymers include a polymer or copolymer containing (meth)acrylic acid as a constituent component, a copolymer containing maleic anhydride as a constituent component, and a compound obtained by reacting a tetracarboxylic dianhydride with a diamine or diol to open the ring of the acid anhydride.

Examples of compounds that accelerate the curing include tertiary amines, quaternary ammonium salts, tertiary phosphines, quaternary phosphonium salts, borate esters, Lewis acids, organometallic compounds, and imidazoles, with 1,8-diazabicyclo[5.4.0]undec-7-ene or 1,5-diazabicyclo[4.3.0]non-5-ene or salts thereof being particularly preferred.

In addition, there is no particular restriction on the solid content concentration of the photosensitive resin composition of the present invention, but for example, for use as a protective film for a color filter, the solid content concentration, which is the total amount of components other than the solvent, is generally adjusted to a range of 10 to 30 mass%. In addition, in order to improve the flatness of the protective film for the color filter, it is preferable to control the drying property of the photosensitive resin composition by using 40 to 90 mass% of a solvent having a boiling point of less than 150°C at normal pressure and 10 to 60 mass% of a solvent having a boiling point of 150°C or more at normal pressure in combination. In addition, it is desirable that the solid content excluding the solvent (solid content includes monomers that become solid content after curing) contains a total of 80 mass% of components (A) to (D), preferably 90 mass% or more. The amount of solvent varies depending on the target viscosity, but it is preferable that it is contained in the photosensitive resin composition in the range of 70 to 90 mass%.

The photosensitive resin composition of the present invention can be formed by curing it using the following photolithography method. First, the photosensitive resin composition is applied onto a glass substrate, a plastic substrate, or the like, or onto a substrate on which a pixel pattern of a color filter or an electrode pattern for driving pixels such as TFTs is formed, and then the solvent is dried (prebaked). After that, a photomask is placed on the film thus obtained, and the exposed parts are cured by irradiating with ultraviolet light. Development is then performed using an alkaline aqueous solution to dissolve the unexposed parts to form a pattern, and post-baking (thermal firing) is further performed as a post-curing method.

Examples of transparent substrates onto which the solution of the photosensitive resin composition is applied include glass substrates and transparent films (e.g., polycarbonate, polyethylene terephthalate, polyethersulfone, etc.) on which transparent electrodes such as ITO or gold are vapor-deposited or patterned. As a method for applying the solution of the photosensitive resin composition, any method such as the well-known solution immersion method, spray method, and methods using a roller coater, land coater, or spinner machine can be used. After applying the solution to the desired thickness by these methods, the solvent is removed (prebaking) to form a film. Prebaking is performed by heating in an oven, hot plate, etc. The heating temperature and heating time in prebaking are appropriately selected depending on the solvent used, and are performed for example at a temperature of 60 to 110°C for 1 to 5 minutes.

The exposure performed after pre-baking is performed using an ultraviolet exposure device, and only the resist in the area corresponding to the pattern is exposed by exposing through a photomask. The exposure device and its exposure irradiation conditions are appropriately selected, and exposure is performed using a light source such as an ultra-high pressure mercury lamp, high pressure mercury lamp, metal halide lamp, or far ultraviolet lamp, to photocure the photosensitive resin composition for black resist in the coating film.

After exposure, alkaline development is carried out in order to remove the unexposed portions of the resist, and the desired pattern is formed by this development. Examples of developers suitable for this alkaline development include aqueous solutions of carbonates of alkali metals or alkaline earth metals, and aqueous solutions of hydroxides of alkali metals. In particular, it is preferable to use a weakly alkaline aqueous solution containing 0.05 to 3 mass % of carbonates such as sodium carbonate, potassium carbonate, or lithium carbonate at a temperature of 23 to 28°C, and fine images can be precisely formed using a commercially available developing machine or ultrasonic cleaner.

After development, a heat treatment (post-baking) is preferably performed at a temperature of 80 to 250°C (set so as not to exceed the heat resistance temperature of the substrate) for 20 to 90 minutes. This post-baking is performed for the purpose of increasing the adhesion between the patterned resin film and the substrate. As with the pre-baking, this is performed by heating in an oven, hot plate, or the like. More preferred ranges for the heat treatment conditions for post-baking are a temperature of 180 to 230°C and a heating time of 30 to 60 minutes. The patterned resin film of the present invention is formed through each of the steps of the photolithography method described above.

The photosensitive composition of the present invention is useful for forming solder resists, plating resists, etching resists, insulating films for multilayering of wiring boards on which semiconductor elements are mounted, gate insulating films for semiconductors, protective films and planarizing films for color filters, partition materials for forming organic EL pixels (for forming RGB by the inkjet method, etc.), insulating films for touch panels, etc., and can be used for display devices such as liquid crystal and organic EL devices that contain these resin film patterns as components, imaging devices, and touch panels.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these. We will start with a preparation example of the photosensitive resin composition of the present invention, and then explain the evaluation results of the coating film formed using the photosensitive resin composition.

First, a synthesis example of (A) an alkali-soluble resin containing a polymerizable unsaturated group will be described. The resin in the synthesis example was evaluated as follows.
[Solid content]
1 g of the resin solution obtained in Synthesis Example was impregnated into a glass filter (weight: _W0 (g)), weighed [ _W1 (g)], and the weight after heating at 160°C for 2 hours [ _W2 (g)] was calculated from the following formula.
Solid content concentration (wt%) = 100 x (W ₂ - W ₀ )/(W ₁ - W ₀ )

[Acid value]
The resin solution was dissolved in dioxane and titrated with a 1/10N KOH aqueous solution using a potentiometric titrator (manufactured by Hiranuma Sangyo Co., Ltd., product name COM-1600) to determine the content.

[Molecular weight]
Measurement was performed using gel permeation chromatography (GPC) [manufactured by Tosoh Corporation, product name: HLC-8220GPC, solvent: tetrahydrofuran, columns: TSKgelSuperH-2000 (2 columns) + TSKgelSuperH-3000 (1 column) + TSKgelSuperH-4000 (1 column) + TSKgelSuper-H5000 (1 column) [manufactured by Tosoh Corporation], temperature: 40° C., rate: 0.6 ml/min], and the weight average molecular weight (Mw) was calculated as a value converted into a standard polystyrene [PS-oligomer kit manufactured by Tosoh Corporation].

[ ²⁹ Si-NMR measurement conditions]
Device name: JNM-ECA400 manufactured by JEOL Ltd.
Observed nucleus: ^29Si
Observation frequency: 79.43MHz
Measurement temperature: room temperature Measurement solvent: CDCl ₃
Pulse width: 8.75 μsec (90°)
Pulse repetition time: 5.0 sec
Number of times of accumulation: 11,000 times Sample concentration (sample/measurement solvent/relaxation reagent): 200 mg/0.7 ml/10 mg
Relaxation agent: Cr(acac) ₃

The abbreviations used in the synthesis examples are as follows.
BPFE: Bisphenol fluorene type epoxy compound [a reaction product of 9,9-bis(4-hydroxyphenyl)fluorene and chloromethyloxirane. Epoxy equivalent: 250 g/eq]
AA: Acrylic acid PGMEA: Propylene glycol monomethyl ether acetate TEAB: Tetraethylammonium bromide BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride THPA: Tetrahydrophthalic anhydride MAA: Methacrylic acid MMA: Methyl methacrylate CHMA: Cyclohexyl methacrylate AIBN: Azobisisobutyronitrile GMA: Glycidyl methacrylate TPP: Triphenylphosphine TBPC: 2,6-di-tert-butyl-p-cresol

<(A) Synthesis of Alkali-Soluble Resin Having Polymerizable Unsaturated Group>
[Synthesis Example 1]
114.4g (0.23 mol) of BPFE, 33.2g (0.46 mol) of AA, 157g of PGMEA and 0.48g of TEAB were charged into a 500ml four-neck flask equipped with a reflux condenser, and the mixture was stirred for 20 hours while heating at 100 to 105 ° C. to react. Next, 35.3g (0.12 mol) of BPDA and 18.3g (0.12 mol) of THPA were charged into the flask, and the mixture was stirred at 120 to 125 ° C. for 6 hours to obtain a polymerizable unsaturated group-containing alkali-soluble resin (A)-1. The solid content concentration of the obtained resin solution was 56.1% by mass, the acid value (solid content equivalent) was 103 mgKOH/g, and the Mw by GPC analysis was 3600. (Polymerizable unsaturated group-containing alkali-soluble resin A-1)

[Synthesis Example 2]
In a 1000 ml four-neck flask equipped with a nitrogen inlet tube and a reflux condenser, 51.65 g (0.60 mol) of MAA, 36.04 g (0.36 mol) of MMA, 40.38 g (0.24 mol) of CHMA, 5.91 g of AIBN, and 360 g of PGMEA were charged, and polymerization was carried out by stirring for 8 hours under a nitrogen stream at 80 to 85 ° C. Further, 61.41 g (0.43 mol) of GMA, 2.27 g of TPP, and 0.086 g of TBPC were charged in the flask, and the mixture was stirred for 16 hours at 80 to 85 ° C. to obtain a polymerizable unsaturated group-containing alkali-soluble resin (A)-2. The solid content concentration of the obtained resin solution was 35.7 mass%, the acid value (solid content equivalent) was 50 mg KOH / g, and the Mw by GPC analysis was 19600. (Polymerizable unsaturated group-containing alkali-soluble resin A-2)

<(C) Synthesis of Siloxane Epoxy Resin>
[Synthesis Example 3]
25.0 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and 150.0 g of toluene were charged into a reaction vessel equipped with a stirrer, a dropping funnel, a thermometer, and a stirrer, and after complete dissolution, 1.25 g of p-toluenesulfonic acid monohydrate was further mixed as an acid catalyst and stirred at room temperature for 30 minutes. 3.3 g of water was further added dropwise and stirred for 24 hours. After the reaction was completed, the mixture was washed with an aqueous NaHCO ₃ solution, the organic layer was dried with MgSO ₄ , filtered, and volatiles were removed under reduced pressure to obtain 18.8 g of a transparent viscous resin. The epoxy equivalent of the obtained resin was 250 g/eq. The Mw was 4100 (Siloxane Epoxy Resin C-1).

[Synthesis Example 4]
20.0 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 5.0 g of 2-(3,4-epoxycyclohexyl)ethylmethyldiethoxysilane, and 150.0 g of toluene were charged into a reaction vessel equipped with a stirrer, a dropping funnel, a thermometer, and a stirrer, and after complete dissolution, 1.25 g of p-toluenesulfonic acid monohydrate was further mixed as an acid catalyst and stirred at room temperature for 30 minutes. 3.1 g of water was further added dropwise and stirred for 24 hours. After the reaction was completed, the mixture was washed with an aqueous NaHCO ₃ solution, the organic layer was dried with MgSO ₄ , filtered, and volatiles were removed under reduced pressure to obtain 20.3 g of a transparent viscous resin. The epoxy equivalent of the obtained resin was 270 g/eq. The Mw was 3200 (siloxane epoxy resin C-2).

[Synthesis Example 5]
12.5 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 12.5 g of 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, and 150.0 g of toluene were charged into a reaction vessel equipped with a stirrer, a dropping funnel, a thermometer, and a stirrer, and after complete dissolution, 1.25 g of p-toluenesulfonic acid monohydrate was further mixed as an acid catalyst and stirred at room temperature for 30 minutes. 3.0 g of water was further added dropwise and stirred for 24 hours. After the reaction was completed, the mixture was washed with an aqueous NaHCO ₃ solution, the organic layer was dried with MgSO ₄ , filtered, and volatiles were removed under reduced pressure to obtain 19.7 g of a transparent viscous resin. The epoxy equivalent of the obtained resin was 230 g/eq. The Mw was 5000 (Siloxane Epoxy Resin C-3).

[Synthesis Example 6]
7.5 g of 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 17.5 g of 2-(3,4-epoxycyclohexyl)ethylmethyldiethoxysilane, and 150.0 g of toluene were charged into a reaction vessel equipped with a stirrer, a dropping funnel, a thermometer, and a stirrer, and after complete dissolution, 1.25 g of p-toluenesulfonic acid monohydrate was further mixed as an acid catalyst and stirred at room temperature for 30 minutes. 2.6 g of water was further added dropwise and stirred for 24 hours. After the reaction was completed, the mixture was washed with an aqueous NaHCO ₃ solution, the organic layer was dried with MgSO ₄ , filtered, and volatiles were removed under reduced pressure to obtain 19.7 g of a transparent viscous resin. The epoxy equivalent of the obtained resin was 290 g/eq. The Mw was 3800 (Siloxane Epoxy Resin C-4).

[Synthesis Example 7]
25.0 g of 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane and 15.0 g of toluene were charged into a reaction vessel equipped with a stirrer, a dropping funnel, a thermometer, and a stirrer, and after complete dissolution, 1.25 g of p-toluenesulfonic acid monohydrate was further mixed as an acid catalyst and stirred at room temperature for 30 minutes. 2.8 g of water was further added dropwise and stirred for 24 hours. After the reaction was completed, the mixture was washed with an aqueous NaHCO ₃ solution, the organic layer was dried with MgSO ₄ , filtered, and volatiles were removed under reduced pressure to obtain 20.1 g of a transparent viscous resin. The epoxy equivalent of the obtained resin was 340 g/eq. The Mw was 3500 (Siloxane Epoxy Resin C-5).

[Synthesis Example 8]
12.5 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 12.5 g of dimethyldiethoxysilane, and 150.0 g of toluene were charged into a reaction vessel equipped with a stirrer, a dropping funnel, a thermometer, and a stirrer, and after complete dissolution, 1.25 g of p-toluenesulfonic acid monohydrate was further mixed as an acid catalyst and stirred at room temperature for 30 minutes. 3.7 g of water was further added dropwise and stirred for 24 hours. After the reaction was completed, the mixture was washed with an aqueous NaHCO ₃ solution, the organic layer was dried with MgSO ₄ , filtered, and volatiles were removed under reduced pressure to obtain 20.0 g of a transparent viscous resin. The epoxy equivalent of the obtained resin was 310 g/eq. The Mw was 2900 (Siloxane Epoxy Resin C-6).

[Synthesis Example 9]
15.0 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 5.0 g of dimethyldiethoxysilane, 5.0 g of methacryloxypropyltrimethoxysilane, and 150.0 g of toluene were charged into a reaction vessel equipped with a stirrer, a dropping funnel, a thermometer, and a stirrer, and after complete dissolution, 1.25 g of p-toluenesulfonic acid monohydrate was further mixed as an acid catalyst and stirred at room temperature for 30 minutes. 3.5 g of water was further added dropwise and stirred for 24 hours. After the reaction was completed, the mixture was washed with an aqueous NaHCO ₃ solution, the organic layer was dried with MgSO ₄ , filtered, and volatiles were removed under reduced pressure to obtain 20.0 g of a transparent viscous resin. The epoxy equivalent of the obtained resin was 260 g/eq. The Mw was 2000 (Siloxane Epoxy Resin C-7).

[Comparative Synthesis Example 1]
25.0 g of (3-glycidoxypropyl)trimethoxysilane, 100.0 g of toluene, and 50.0 g of 2-propanol (IPA) were charged into a reaction vessel equipped with a stirrer, dropping funnel, thermometer, and stirrer, and after complete dissolution, 7.5 g of a 5% aqueous solution of tetramethylammonium hydroxide (aqueous solution of TMAH) was added as a basic catalyst and stirred at room temperature for 24 hours. After the reaction was completed, the mixture was washed with an aqueous solution of citric acid, and the organic layer was dried over MgSO ₄ and filtered, after which volatiles were removed under reduced pressure to obtain 20.4 g of a transparent viscous resin. The epoxy equivalent of the obtained resin was 169 g/eq and Mw was 28,000 (siloxane epoxy resin c-1).

(Preparation of Photosensitive Resin Composition)
The compositions shown in Tables 1 to 4 were mixed and stirred at room temperature for 3 hours to dissolve the solid components in the solvent, thereby preparing photosensitive resin compositions. The composition values are in parts by mass.

The components used in the photosensitive resin composition in the examples and comparative examples are shown below.
<(A) Alkali-soluble resin containing polymerizable unsaturated group>
A-1: Resin solution obtained in Synthesis Example 1 A-2: Resin solution obtained in Synthesis Example 2 <(B) Photopolymerizable monomer>
B-1: Mixture of dipentaerythritol pentaacrylate and hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., product name: DPHA)
<(C) Siloxane Epoxy Resin>
C-1: Siloxane epoxy resin prepared in Synthesis Example 3 C-2: Siloxane epoxy resin prepared in Synthesis Example 4 C-3: Siloxane epoxy resin prepared in Synthesis Example 5 C-4: Siloxane epoxy resin prepared in Synthesis Example 6 C-5: Siloxane epoxy resin prepared in Synthesis Example 7 C-6: Siloxane epoxy resin prepared in Synthesis Example 8 C-7: Siloxane epoxy resin prepared in Synthesis Example 9 C-8: Condensate of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and dimethyldimethoxysilane ("6730D" manufactured by Tsunehashi Sangyo, epoxy equivalent 295/eq, Mw: 4,500)
c-1: Siloxane epoxy resin prepared in Comparative Synthesis Example 1 (epoxy equivalent: 169 g/eq, Mw: 28,000)
c-2: Siloxane epoxy resin having an epoxycyclohexyl group ("X-40-2669" manufactured by Shin-Etsu Chemical Co., Ltd., epoxy equivalent 191 g/eq, Mw: 383)
c-3: Siloxane epoxy resin having an epoxycyclohexyl group ("KR-470" manufactured by Shin-Etsu Chemical Co., Ltd., epoxy equivalent 200 g/eq, Mw: 737)
c-4: Siloxane epoxy resin having a methoxy group, an ethoxy group, and a glycidyl group ("X-41-1059A" manufactured by Shin-Etsu Chemical Co., Ltd., epoxy equivalent 350 g/eq, Mw: 2,500)
c-5: Siloxane epoxy resin having an epoxycyclohexyl group but no hydroxyl group, methoxy group, ethoxy group, or phenoxy group ("POLY200" manufactured by Arakawa Chemical Industries, Ltd.)
<(D) Photopolymerization initiator>
D-1: 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(O-benzoyloxime) (manufactured by BASF, trade name: Irgacure OXE-01)
<(E) Non-siloxane type compound>
E-1: Fluorene-type epoxy resin (manufactured by Nippon Steel Chemical & Material Co., Ltd., ESF-300C, epoxy equivalent 220 to 240/eq)
E-2: 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol (manufactured by Daicel Corporation, EHPE3150, epoxy equivalent: 170 to 190 g/eq)
<Coupling Agent>
F-1: 3-glycidoxypropyltrimethoxysilane <surfactant>
G-1: Megafac F-477 (manufactured by DIC)
<Solvent>
H-1: Propylene glycol monomethyl ether acetate (PGMEA)
H-2: Propylene glycol monomethyl ether (MMPG)
H-3: Diethylene glycol ethyl methyl ether (EDM)

The siloxane epoxy resin component (C) used in the formulation was subjected to ^29Si -NMR measurement under the above conditions using a nuclear magnetic resonance apparatus (JNM-ECA 400 manufactured by JEOL Ltd.). As a result, in components C-1 to C-8 and components c-1 and c-4, signals at 47 ppm to -52 ppm, -55 ppm to -61 ppm, and -62 ppm to -72 ppm, which are derived from the structures T1, T2, and T3, were observed. In components C-2, C-4, C-6, and C-7, signals at -6 ppm to -13 ppm and -15 ppm to -24 ppm, which are derived from the structures D1 and D2, were further observed.
The area ratios of each signal were as follows: for C -8, T1:T2:T3=1:7:15, and D1:D2=4:26.

(Evaluation of Photosensitive Resin Composition: Flatness)
A color filter substrate was prepared in which a black matrix, red, green, and blue pixels, and a mosaic pattern without blue pixels were formed, and unevenness of 2.5 μm in height was generated on the pixels. The above-mentioned photosensitive resin composition was applied to the color filter substrate using a spin coater, and dried on a hot plate at 90 ° C for 2 minutes to prepare a test piece. At this time, the application conditions (spin rotation speed) were adjusted so that a cured film with a film thickness of 1.5 μm was obtained on the pixel. Next, ultraviolet rays of 50 mJ/cm ² were irradiated from an ultra-high pressure mercury lamp with an i-line illuminance of 30 mW/cm ² to perform a photocuring reaction. The test piece was then baked in a hot air oven at 230 ° C for 30 minutes to obtain a cured film of the curable resin composition.

The height of the unevenness at two arbitrarily selected points on the surface of the cured film formed to protect the pixels was measured with a contact surface roughness meter (product name: Microprofile Measuring Instrument ET-4000A, manufactured by Kosaka Laboratory Co., Ltd.), and evaluated into three levels according to the following criteria.
◎ (Good): The height difference between the projections and recesses is 0.20 μm or less. ○ (Fair): The height difference between the projections and recesses is more than 0.20 μm and 0.30 μm or less. △ (Fair): The height difference between the projections and recesses is more than 0.30 μm and 0.40 μm or less. × (Fail): The height difference between the projections and recesses is more than 0.40 μm.

(Evaluation of Photosensitive Resin Composition: Moisture Absorption)
The photosensitive resin composition was applied to an alkali-free glass substrate using a spin coater, and dried on a hot plate at 90 ° C for 2 minutes to prepare a test piece. At this time, the coating conditions (spin rotation speed) were adjusted so that a cured film with a film thickness of 1.5 μm was obtained. Next, a photocuring reaction was carried out by irradiating ultraviolet light of 50 mJ / cm ² from an ultra-high pressure mercury lamp with an i-line illuminance of 30 mW / cm ^2. Thereafter, the test piece was baked in a hot air oven at 230 ° C for 30 minutes to obtain a cured film of the photosensitive resin composition. Next, the substrate with the cured film was left to stand for 24 hours in a constant temperature and constant room device (Espec environmental tester SH-221) under an environment of 85 ° C and humidity 85% RH to absorb moisture. A 10 mg sample was scraped off from the cured film of this test piece, and this sample was heated from room temperature to 150°C at a rate of 10°C/min in a nitrogen atmosphere and held at 150°C for 20 minutes. The weight loss when this was measured as the weight change due to moisture absorption of the film using a thermogravimetric analyzer (product name: Thermo plus EVO2 differential thermobalance, manufactured by Rigaku Corporation) and evaluated on a three-level scale according to the following criteria:
◎: Weight loss is less than 0.5%. ○: Weight loss is 0.5% or more and less than 2%. △: Weight loss is 2% or more and less than 3%. ×: Weight loss is 3% or more.

(Evaluation of Photosensitive Resin Composition: Gas Generation)
The photosensitive resin composition was applied to an alkali-free glass substrate using a spin coater, and dried on a hot plate at 90°C for 2 minutes to prepare a test piece. At this time, the application conditions (spin rotation speed) were adjusted so that a cured film with a film thickness of 1.5 μm was obtained. Next, a photocuring reaction was carried out by irradiating ultraviolet rays of 50 mJ/ ^cm2 from an ultra-high pressure mercury lamp with an i-line illuminance of 30 mW/ ^cm2 . Thereafter, the test piece was baked in a hot air oven at 230°C for 30 minutes to obtain a cured film of the curable resin composition. A sample of 10 mg of the cured film was scraped off from the test piece, and this was sampled in an air flow, heated from room temperature to 120°C at a rate of 10°C/min, held at 120°C for 30 minutes, and then heated from 120°C to 230°C at a rate of 10°C/min and held at 230°C for 3 hours. The weight loss during this period was measured using a thermogravimetric analyzer (product name: Thermo plus EVO2 differential thermobalance, manufactured by Rigaku Corporation) and evaluated on a three-level scale according to the following criteria.
◎: Weight loss is less than 5%. ○: Weight loss is 5% or more but less than 7%. △: Weight loss is 7% or more but less than 10%. ×: Weight loss is 10% or more.

(Evaluation of Photosensitive Resin Composition: Transparency)
Test pieces each having a cured film of the photosensitive resin composition formed thereon were prepared in the same manner as in the gas generation evaluation described above. The transmittance of the cured film at a wavelength of 400 nm was measured with a spectrophotometer and evaluated on a three-level scale according to the following criteria.
◎: Transmittance is 97% or more. ○: Transmittance is 95% or more. △: Transmittance is 93% or more but less than 95%. ×: Transmittance is less than 93%.

(Creation of cured film (coating film) for evaluating development characteristics)
The photosensitive resin composition shown in the table was applied to a 125 mm x 125 mm glass substrate "#1737" (manufactured by Corning) (hereinafter referred to as "glass substrate"), the surface of which had been cleaned by irradiating it with ultraviolet light having a wavelength of 254 nm and an illuminance of 1000 mJ/ ^cm2 from a low pressure mercury lamp, using a spin coater so that the film thickness after heat curing treatment would be 2.0 μm, and a hardened film (coating film) was produced by pre-baking for 2 minutes at 90°C using a hot plate. Next, the exposure gap was adjusted to 100 μm, and a negative photomask of 10 to 50 μm (in 5 μm increments) was placed on the cured film (coating film), and ultraviolet light of 50 mJ/ ^cm2 was irradiated from an ultra-high pressure mercury lamp with an i-line illuminance of 30 mW/ ^cm2 to carry out a photocuring reaction.

Next, the exposed cured film (coating film) was developed at 25°C with a 0.04% potassium hydroxide solution at a shower pressure of 1 kgf/ ^cm2 for 20 seconds from the development time (break time = BT) at which a pattern began to appear, and then washed with water sprayed at 5 kgf/ ^cm2 to remove the unexposed parts of the cured film (coating film) to form a cured film pattern on the glass substrate. Thereafter, the test piece was baked in a hot air oven at 230°C for 30 minutes to obtain a cured film of the curable resin composition.

[Evaluation of Development Characteristics]
(Pattern Adhesion)
(Evaluation Method)
After the main curing (post-baking), the 20 μm mask pattern was observed under an optical microscope.

(Evaluation Criteria)
◎: No peeling at all ○: Slight peeling △: Partial peeling ×: Most of the peeling

(Pattern Linearity)
(Evaluation Method)
After the main curing (post-baking), the 20 μm mask pattern was observed under an optical microscope.

(Evaluation Criteria)
⊚: No jagged edges at all observed on the pattern edges ◯: Slight jagged edges observed on the pattern edges
△: Jagged edges are partially observed at the edge of the pattern. ×: Jagged edges are mostly observed at the edge of the pattern.

(Pattern definition)
(Evaluation Method)
After the main curing (post-baking), the 10 to 50 μm mask pattern was observed under an optical microscope.

(Evaluation Criteria)
◎: A pattern of 10 to 15 μm is formed. ○: A pattern of 16 to 24 μm is formed. △: A pattern of 25 to 50 μm is formed. ×: No pattern is formed.

Claims (6)

(A) an alkali-soluble resin containing a polymerizable unsaturated group represented by the following general formula (1),
(B) a photopolymerizable monomer having at least two ethylenically unsaturated bonds;
(C) a siloxane epoxy compound which satisfies the following (i) to (iii) or satisfies the following (i) to (iv) and has a group represented by the following formula (4) or (5):
(D) a photopolymerization initiator;
Including,
The (C) is obtained by hydrolyzing or hydrolyzing and condensing a trialkoxysilane represented by the general formula Si(X ¹ )(OR ₁₀ ) ₃ , or by hydrolyzing or hydrolyzing and condensing this Si(X ¹ )(OR ₁₀ ) ₃ with a dialkoxysilane represented by the general formula Si(X ² ) ₂ (OR ₁₁ ) ₂ (wherein, the X ¹ is a group shown in (a) or (b) below, which may be the same or different, but at least one of them includes (a). The X ² is a group shown in (a) or (b) below, which may be the same or different, but at least one of them has the group shown in (b). R ₁₀ and R ₁₁ are each independently an alkyl group or a phenyl group having 1 to 3 carbon atoms) .
A photosensitive resin composition comprising:
(i) In a ^29Si -NMR spectrum, it has the following structure T1 which shows a signal at -47 ppm to -52 ppm, the following structure T2 which shows a signal at -55 ppm to -61 ppm, and the following structure T3 which shows a signal at -62 ppm to -72 ppm, and the signal area ratio of T1:T2:T3 is 1:1 to 10:1 to 100.
(ii) The weight average molecular weight is 750 to 20,000.
(iii) The epoxy equivalent weight is less than 350.
(iv) In the ²⁹ Si-NMR spectrum, it contains the following structure D1 which exhibits a signal at -9 ppm to -13 ppm and the following structure D2 which exhibits a signal at -15 ppm to -24 ppm.

[In Structures T1 to T3, R is a hydrogen group, a methyl group, an ethyl group, or a phenyl group, and X is the following (a) or (b), which may be the same or different, but at least one X in each of Structures T1 to T3 is (a).
(a) a 3,4-epoxycyclohexyl group, or a group having a 3,4-epoxycyclohexyl group at the terminal of an organic group having 1 to 6 carbon atoms
(b) an organic group having 1 to 6 carbon atoms]

[In formula (1), R ₁ , R ₂ , R ₃ and R ₄ each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom or a phenyl group; R ₅ represents a hydrogen atom or a methyl group; A represents -CO-, -SO ₂ -, -C(CF ₃ ) ₂ -, -Si(CH ₃ ) ₂ -, -CH ₂ -, -C(CH ₃ ) ₂ -, -O-, a fluorene-9,9-diyl group or a direct bond; X ₁ represents a tetravalent carboxylic acid residue; Y ₁ and Y ₂ each independently represent a hydrogen atom or -OC-Z-(COOH) _m (wherein Z represents a divalent or trivalent carboxylic acid residue and m represents the number 1 or 2); and n represents an integer of 1 to 20.]

[In the above formulas (4) and (5), j, k, s, and t are
1≦j+k≦7 (j≧0, k≧1)
2≦s+t≦100 (s≧1, t≧1)
The symbol * represents a bond, which constitutes a Si-O-Si bond when linked. In addition, X in formula (4) and formula (5) is the above-mentioned (a) or (b), and may be the same or different, but contains one or more of (a). Furthermore, R' in formula (4) and formula (5) is a hydroxyl group, a hydrocarbon group having 1 to 3 carbon atoms, a phenyl group, a methoxy group, an ethoxy group, or a group represented by the following formula (6).

[In formula (6), R _X is a hydroxyl group, a hydrocarbon group having 1 to 3 carbon atoms, a phenyl group, a methoxy group, or an ethoxy group, and X is the above-mentioned (a) or (b). * represents a bond, and when linked together, forms a Si-O-Si bond.]

[In structures D1 and D2, R is a hydrogen group, a methyl group, an ethyl group, or a phenyl group, and Y is either (a) or (b) as defined above, and may be the same or different in each of structures D1 and D2.] 2. The photosensitive resin composition according to claim 1 , wherein the solid content of the siloxane epoxy compound is 3% by mass or more and 25% by mass or less based on the total mass of the solid contents. 3. The photosensitive resin composition according to claim 1, further comprising a non-siloxane compound that does not contain a siloxane skeleton and has an epoxy group or a polymerizable unsaturated bond. 4. The photosensitive resin composition according to claim 3 , wherein the non-siloxane compound is an epoxy compound represented by the following formula (7):

[In formula (7), Ar is a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. Some of the hydrogen atoms of the divalent aromatic hydrocarbon group represented by Ar may be substituted with a hydrocarbon group having 1 to 10 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a halogen group. The average value of l is 0 to 2.] A cured product obtained by curing the photosensitive resin composition according to any one of claims 1 to 4 . A display device comprising the cured product according to claim 5 as a component.