TWI876017B - Photosensitive resin composition, cured product thereof, and display device with that - Google Patents

Abstract

The present invention provides a photosensitive resin composition having flatness, extremely good low hygroscopicity, low gas generation, excellent transparency, and excellent developing characteristics, a cured product thereof, and a display device comprising the cured product. A photosensitive resin composition is characterized by comprising: (A) an alkali-soluble resin containing a polymerizable unsaturated group; (B) a photopolymerizable monomer having at least two ethylenic unsaturated bonds; (C) a siloxane epoxy compound; and (D) a photopolymerization initiator.

Description

Photosensitive resin composition, cured product thereof, and display device including the cured product

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

In display elements such as liquid crystal display elements, organic electroluminescent elements (organic EL (electroluminescence) elements), and electronic paper elements, there are hardened films such as protective films to prevent degradation or damage of electronic parts such as touch screens, interlayer insulation films to maintain insulation between wiring arranged in layers, and flattening films to increase the opening rate. In the past, a transparent hardened film (hereinafter also referred to as a protective film) was formed on the surface of the color filter used in the manufacture of a color liquid crystal display (LCD). The protective film of the color filter can be formed for the following purposes: to flatten the unevenness generated between pixels of the color filter, to improve the reliability of the color liquid crystal display, etc. As a protective film for color filters, it is required to have excellent flatness, developability, and transparency.

For example, as flatness, it is required to flatten the 1μm to 2μm high concavities and convexities generated by repeated coating of the coloring composition when forming pixels to less than 0.2μm. As for developing properties, it is required to form fine lines of about 20μm without pattern peeling or sawing. As for transparency, it is required that the protective film has no absorption in the visible light wavelength region and does not damage the color characteristics of the color filter.

In addition to the above-mentioned requirements for the protective film, as the LCD panel becomes more functional, a wide viewing angle and high-speed response are also required. In the process of using display methods such as the in-plane switching (IPS) mode, the requirements for the protective film are becoming more stringent. In display methods such as the IPS mode, if the gaseous or liquid components or water generated or bleeds out from the color filter layer enters the liquid crystal layer through the protective layer, the concentration of water or ionic impurities in the liquid crystal layer increases, or bubbles are formed in the liquid crystal, which will cause poor display. Therefore, in terms of preventing the passage of the impurity components, and in terms of the fact that the gas generation from the protective film in direct contact with the liquid crystal layer is directly related to poor display, low gas generation is particularly important. 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 flatness requirements for achieving flatness in thin films have also become stricter. In other words, the following situation has arisen: a new issue of balancing low gas generation and flatness has emerged.

As materials for color filter protective films, a large number of epoxy or acrylic compound compositions have been proposed so far (Patent Documents 1 to 5, etc.), but no material has been found that satisfies the required properties of low gas generation and flatness at the same time.

On the other hand, siloxane epoxy resins having 3,4-epoxyhexyl groups have been proposed (Patent Document 6) or the use of the materials as materials for forming cured films or as materials for color filters (Patent Documents 7 to 9, etc.), but the siloxane structure has not been focused on in detail, and low gas generation or flatness has not been discussed (Patent Documents 7 to 8, etc.).

[Prior art literature]

[Patent Literature]

[Patent Document 1] International Publication No. 96/34303

[Patent document 2] Japanese Patent Publication No. 2000-103937

[Patent document 3] Japanese Patent Publication No. 2000-143772

[Patent document 4] Japanese Patent Publication No. 2001-091732

[Patent document 5] Japanese Patent Publication No. 2004-069930

[Patent Document 6] WO2015/151957

[Patent Document 7] Japanese Patent Publication No. 2005-338790

[Patent Document 8] Japanese Patent Publication No. 2012-241118

[Patent Document 9] Japanese Patent Publication No. 2017-171748

As described above, the following situation exists: in the protective film of the color filter, on the basis of satisfying the required characteristics of low hygroscopicity, low gas generation and flatness, it is necessary to highly maintain the necessary characteristics of the protective film for the color filter, such as developability and transparency, and the application range of the protective film material that can satisfy the above situation as a composition is narrowed.

Furthermore, in recent years, color filters (RGBW method) have been developed that have white (W) pixels that are not coated with color filters in addition to red, green, and blue (RGB), and the protective film is also required to fill the W space that is not coated with the color composition while satisfying flatness. In other words, in addition to the previous 1μm~2μm bumps on the pixels, the larger 2μm~3μm concave spaces are gradually required to be flattened using a thin film with a film thickness of less than 2μm on the colored pixel formation part.

The present invention is made in view of the above-mentioned problems, and aims to provide a photosensitive resin composition that can form a protective film that satisfies the required properties of flatness, low moisture absorption, and low gas generation, and has excellent developability and transparency, a cured product obtained by curing the composition, and a display device using the cured product as a structural element.

The inventors of the present invention conducted research to understand and solve the problem required by the protective film of the color filter, and found that the problem can be solved by using a photosensitive resin composition with a specific formulation, thus completing the present invention.

That is, the gist of the present invention is as follows.

[1] A photosensitive resin composition, characterized by comprising: (A) an alkali-soluble resin containing a polymerizable unsaturated group; (B) a photopolymerizable monomer having at least two ethylenic unsaturated bonds; (C) a siloxane epoxy compound satisfying the following (i) to (iii); and (D) a photopolymerization initiator.

(i) having the following structure T1 showing a signal at -47ppm to -52ppm, the following structure T2 showing a signal at -55ppm to -61ppm, and the following structure T3 showing a signal at -62ppm to -72ppm in a ²⁹ Si-nuclear magnetic resonance (NMR) spectrum, and the area ratio of the signals is T1:T2:T3=0~1:1~10:1~100.

(ii) Weight average molecular weight is 750~20000.

(iii) The epoxy equivalent is less than 350.

[In structures T1 to T3, R is hydrogen, methyl, ethyl or phenyl, and X is (a) or (b) below, which may be the same or different. In each structure, at least one X is (a).

(a) 3,4-epoxycyclohexyl, or a group having a 3,4-epoxycyclohexyl at the end of an organic group having 1 to 6 carbon atoms

(b) Organic groups with 1 to 6 carbon atoms]

[2] The photosensitive resin composition according to [1], wherein the siloxane epoxy compound contains the following structure D1 showing a signal at -9ppm to -13ppm and the following structure D2 showing a signal at -15ppm to -24ppm in the ²⁹ Si-NMR spectrum.

[In structure D1~structure D2, R is hydrogen, methyl, ethyl or phenyl, and Y is (a) or (b) described above, which may be the same or different in each structure.]

[3] The photosensitive resin composition according to [1] or [2], characterized in that the solid content of the siloxane epoxy compound is greater than 3% by mass and less than 25% by mass relative to the total mass of the solid components.

[4] A photosensitive resin composition according to any one of [1] to [3], characterized in that it contains a non-silicone 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] is characterized in that the non-silicone type compound is an epoxy compound represented by the following formula (7).

[In formula (7), Ar is a divalent aromatic alkyl group having 6 to 12 carbon atoms. In addition, a portion of the hydrogen atoms of the divalent aromatic alkyl group represented by Ar may be substituted by a alkyl 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] A photosensitive resin composition according to any one of [1] to [5], characterized in that: the component (A) is an alkali-soluble resin containing a polymerizable unsaturated group represented by the general formula (1).

[Chemistry 4]

[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-, fluorene-9,9-diyl 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 a number of 1 or 2), and n represents an integer of 1 to 20.]

[7] A cured product obtained by curing the photosensitive resin composition described in any one of [1] to [6].

[8] A display device comprising the hardened material according to [7] as a structural element.

The photosensitive resin composition of the present invention can form a cured product (cured film) that satisfies the required properties of flatness, extremely good low moisture absorption, and low gas generation, and is also excellent in heat resistance, chemical resistance, electrical reliability, and transparency. The photosensitive resin composition of the present invention can of course be used as a protective film for color filters of LCDs including RGBW methods, and in particular, can also be used in display devices that require a transparent cured film with excellent flatness and low gas generation. That is, as a structural element of organic EL display devices other than LCDs, micro-light emitting diode (μLED) display devices, and display devices using quantum dots, it can be preferably used, especially in the case of a transparent film that needs to flatten bumps or steps. Furthermore, it can also be applied to sensors such as complementary metal oxide semiconductor (CMOS) equipped with color filter layers. In addition, it can also be used as an insulating film layer for semiconductor devices, multi-layer printed wiring boards, or touch screens, especially when flatness is required. Furthermore, it is widely used in various applications such as optical applications that require transparency, heat resistance, low moisture absorption, etc., optical device applications, mechanical parts materials, electrical and electronic parts materials, etc., automotive parts materials, civil engineering materials, molding materials, coatings or adhesives.

The photosensitive resin composition of the present invention contains the specified (A) alkali-soluble resin containing polymerizable unsaturated groups, (B) photopolymerizable monomers having at least two ethylenic unsaturated bonds, (C) epoxy compounds, and (D) photopolymerization initiators. In addition, the photosensitive resin composition may contain surfactants, solvents, etc. The details of these components are described in turn below.

<(A) Alkaline soluble resin containing polymerizable unsaturated groups>

The polymerizable unsaturated group-containing alkali-soluble resin as component (A) can be used without particular limitation as long as it has a polymerizable unsaturated group and an acidic group in the molecule. Here, as a representative example of the polymerizable unsaturated group, there are an acryl group or a methacrylic group, and as a representative example of the acidic group, there is a carboxyl group.

The preferred weight average molecular weight (Mw) and acid value range of the alkali-soluble resin containing polymerizable unsaturated groups vary depending on the resin skeleton, but Mw is preferably 2000~50000, and acid value is preferably 30mgKOH/g~120mgKOH/g. If Mw is less than 2000, the adhesion of the pattern during alkali development may be reduced, and if Mw exceeds 50000, the development property is significantly reduced, and it may not be possible to obtain a photosensitive resin composition with an appropriate development time. In addition, when the acid value is less than 30, residues are likely to remain during alkaline development. When the acid value is greater than 120, the alkaline developer penetrates too quickly, and the desired dissolution development may not be achieved, and peeling development may occur. Furthermore, it is more preferred that the Mw is 2000~25000 and the acid value is 40mgKOH/g~110mgKOH/g. Furthermore, the alkaline-soluble resin containing a polymerizable unsaturated group can be used alone or in combination of two or more.

The first preferred example of component (A) is an epoxy (meth)acrylate acid adduct, which is obtained by reacting a compound having two or more epoxy groups with (meth)acrylic acid (which means "acrylic acid and/or methacrylic acid") to obtain an epoxy (meth)acrylate compound having a hydroxyl group, and reacting (I) a dicarboxylic acid or tricarboxylic acid monoanhydride and/or (II) a tetracarboxylic dianhydride with the obtained epoxy (meth)acrylate compound having a hydroxyl group. As a compound having two or more epoxy groups from which an epoxy (meth)acrylate acid adduct is derived, a bisphenol type epoxy compound or a novolac type epoxy compound can be cited.

Bisphenol type epoxy compounds are epoxy compounds having two glycidyl ether groups obtained by reacting bisphenols with epichlorohydrin. Since the above reaction is generally accompanied by oligomerization of the diglycidyl ether compound, epoxy compounds having two or more bisphenol skeletons are included. Examples of bisphenols used in the reaction include bis(4-hydroxyphenyl)ketone, bis(4-hydroxy-3,5-dimethylphenyl)ketone, bis(4-hydroxy-3,5-dichlorophenyl)ketone, bis(4-hydroxyphenyl)sulfate, bis(4-hydroxy-3,5-dimethylphenyl)sulfate, bis(4-hydroxy-3,5-dichlorophenyl)sulfate, bis(4-hydroxyphenyl)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) 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-hydroxy-3-chlorophenyl)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 them, bisphenols having a fluorene-9,9-diyl group are particularly preferred.

As the (I) dicarboxylic acid or tricarboxylic acid monoanhydride to be reacted with epoxy (meth)acrylate, there can be used a monoanhydride of a chain alkyl dicarboxylic acid or tricarboxylic acid, a monoanhydride of alicyclic dicarboxylic acid or tricarboxylic acid, or a monoanhydride of an aromatic dicarboxylic acid or tricarboxylic acid, etc. Here, examples of the monoanhydride of the chain alkyl dicarboxylic acid or tricarboxylic acid include 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. In addition, examples of the monoanhydride of alicyclic dicarboxylic acids or tricarboxylic acids include monoanhydrides of cyclobutanedicarboxylic acid, cyclopentanedicarboxylic acid, hexahydrophthalic acid, tetrahydrophthalic acid, norbornanedicarboxylic acid, etc., and also include those in which any substituent is introduced. In addition, examples of the monoanhydride of aromatic dicarboxylic acids or tricarboxylic acids include monoanhydrides of phthalic acid, isophthalic acid, trimellitic acid, etc., and also include those in which any substituent is introduced.

In addition, as the (II) tetracarboxylic acid dianhydride to be reacted with epoxy (meth)acrylate, the dianhydride of a chain alkane tetracarboxylic acid, the dianhydride of alicyclic tetracarboxylic acid, or the dianhydride of an aromatic tetracarboxylic acid can be used. Here, examples of the dianhydride of the chain alkane tetracarboxylic acid include dianhydrides of butane tetracarboxylic acid, pentane tetracarboxylic acid, hexane tetracarboxylic acid, and the like, and further include those having any substituent introduced therein. In addition, examples of the dianhydride of alicyclic tetracarboxylic acid include dianhydrides of cyclobutane tetracarboxylic acid, cyclopentane tetracarboxylic acid, cyclohexane tetracarboxylic acid, cycloheptane tetracarboxylic acid, norbornane tetracarboxylic acid, and the like, and further include those having any substituent introduced therein. Furthermore, examples of the dianhydride of the aromatic tetracarboxylic acid include dianhydrides of pyromellitic acid, benzophenone tetracarboxylic acid, biphenyl tetracarboxylic acid, biphenyl ether tetracarboxylic acid, and the like, and further include those in which any substituent is introduced.

The molar ratio (I)/(II) of the acid monoanhydride of (I) dicarboxylic acid or tricarboxylic acid and the acid dianhydride of (II) tetracarboxylic acid that react with epoxy (meth)acrylate is preferably 0.01 to 10.0, 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 the optimal molecular weight for preparing a photosensitive resin composition with good photopatterning properties. Furthermore, the smaller the molar ratio (I)/(II), the larger the molecular weight, and the alkali solubility tends to decrease.

Epoxy (meth)acrylate acid adducts can be produced by known methods, such as the methods described in Japanese Patent Laid-Open No. 8-278629 or Japanese Patent Laid-Open No. 2008-9401. First, in an example of a method for reacting (meth)acrylic acid with an epoxy compound, there is a method in which (meth)acrylic acid is added to a solvent in an amount equimolar to the epoxy group of the epoxy compound, and the mixture is heated and stirred at 90°C to 120°C in the presence of a catalyst (triethylbenzylammonium chloride, 2,6-diisobutylphenol, etc.) while blowing air to react. Next, in an example of a method for reacting an acid anhydride with a hydroxyl group of an epoxy acrylate compound as a reaction product, there is a method in which a predetermined amount of an epoxy acrylate compound, an acid dianhydride, and an acid monoanhydride are added to a solvent, and the mixture is heated and stirred at 90°C to 130°C in the presence of a catalyst (tetraethylammonium bromide, triphenylphosphine, etc.) to react. The epoxy acrylate acid adduct obtained by the above method has a skeleton of the 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-, fluorene-9,9-diyl 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 a number of 1 or 2), and n represents an integer of 1 to 20.]

Another preferred example of the polymerizable unsaturated group-containing alkali-soluble resin as component (A) includes a resin having a (meth)acrylic group and a carboxyl group in a copolymer such as (meth)acrylic acid and (meth)acrylic ester. The resin is, for example, a polymerizable unsaturated group-containing alkali-soluble resin obtained as follows: as a first step, (meth)acrylic esters including (meth)acrylic acid glycidyl ester are copolymerized in a solvent to obtain a copolymer, as a second step, (meth)acrylic acid is reacted with the obtained copolymer, and in a third step, the copolymer is reacted with an anhydride of a dicarboxylic acid or a tricarboxylic acid. For examples of these copolymers that can be preferably used, reference can be made to the examples specifically shown in Japanese Patent Application No. 2017-33662. Another method for obtaining such a resin (copolymer) having a (meth)acrylic group and a carboxyl group may be the following method: as a first step, (meth)acrylic acid and (meth)acrylic ester are copolymerized in a solvent to obtain a copolymer, as a second step, (meth)acrylic acid glycidyl ester is reacted with the obtained copolymer, and in a third step, the copolymer is reacted with an anhydride of a dicarboxylic acid or a tricarboxylic acid.

As another example, a carbamate compound is obtained by reacting a polyol compound having an ethylenic 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 a resin of the above system, the resin shown in Japanese Patent Publication No. 2017-76071 can be referred to.

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

<(B) A 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, trihydroxymethylpropane tri(meth)acrylate, trihydroxymethylethane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, and tetramethylolpropane tri(meth)acrylate. (Meth)acrylates such as pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, glycerol tri(meth)acrylate, sorbitol penta(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, sorbitol hexa(meth)acrylate, phosphazene epoxide-modified hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, and (meth)acrylates, and dendrimers having (meth)acryloyl groups as compounds having ethylenic double bonds. 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 in crosslinking the molecules of the alkali-soluble resin containing a polymerizable unsaturated group. In order to play the role, it is preferred to use a monomer having three or more ethylenic double bonds. In addition, the acrylic acid equivalent obtained by dividing the molecular weight of the monomer by the number of (meth)acrylic groups in one molecule is preferably 50 to 300, and the acrylic acid equivalent is more preferably 80 to 200. In addition, component (B) does not have a free carboxyl group.

Examples of dendrimers having (meth)acrylic groups as compounds having ethylenic double bonds include dendrimers obtained by adding a polyhydric alkyl compound to a portion of the carbon-carbon double bonds in the (meth)acrylic ester group of a polyfunctional (meth)acrylic ester compound. Specifically, the dendrimers include those obtained by reacting the (meth)acrylic ester of a polyfunctional (meth)acrylic ester compound of the general formula (2) with the polyhydric alkyl compound of the general formula (3).

Here, R ₆ represents a hydrogen atom or a methyl group, and R ₇ represents the remainder after one of the p hydroxyl groups of R ₈ (OH) _p is provided to the ester bond in the formula. Preferably, R ₈ (OH) _p is a polyol based on a non-aromatic linear or branched hydrocarbon skeleton having 2 to 8 carbon atoms, or a polyol ether formed by dehydration condensation of a plurality of molecules of the polyol and linked via an ether bond, or an ester of these polyols or polyol ethers with a hydroxy acid. p and q independently represent integers of 2 to 20, and p≧q.

Here, R ₉ is a single bond or a divalent to hexavalent C1 to C6 hydrocarbon group. When R ₉ is a single bond, r is 2. When R ₉ is a divalent to hexavalent group, r represents an integer of 2 to 6.

Specific examples of the multifunctional (meth)acrylate compound represented by general formula (2) include (meth)acrylates such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, trihydroxymethylpropane tri(meth)acrylate, ethylene oxide-modified trihydroxymethylpropane 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 the polyolefin compounds represented by general formula (3) include trihydroxymethylpropane tri(olefin acetate), trihydroxymethylpropane tri(olefin propionate), pentaerythritol tetra(olefin acetate), pentaerythritol tri(olefin acetate), pentaerythritol tetra(olefin propionate), dipentaerythritol hexa(olefin acetate), dipentaerythritol hexa(olefin propionate), etc. These compounds may be used alone or in combination of two or more.

Here, the mixing ratio [(A)/(B)] of the above-mentioned component (A) and component (B) is preferably 20/80~90/10, and more preferably 40/60~70/30. Here, if the mixing ratio of the component (A) is too low, the cured product after the photocuring reaction becomes brittle, and the acid value of the coating on the unexposed part is low, so the solubility in the alkaline developer is reduced, resulting in problems such as the pattern edge shaking and not becoming sharp. On the contrary, if the mixing ratio of the component (A) is more than the above-mentioned range, the proportion of the photoreactive functional group in the photoreactive component (component (A) + component (B)) is small, and the cross-linked structure formed by the photocuring reaction may become insufficient.

<(C) Epoxides>

The epoxy compound of component (C) in the present invention is a siloxane epoxy resin having a siloxane-derived structure as shown below.

Here, the chemical shifts of the silicon-bonded units T and D in the ²⁹ Si-NMR spectrum are observed in the ranges of T unit: -45ppm~-80ppm, D unit: 0ppm~-40ppm. In the epoxy compound of the component (C) of the present invention, as the T unit, signals are shown in the ranges of -47ppm~-52ppm, -55ppm~-61ppm, and -62ppm~-72ppm, respectively, which indicate signals originating from the silicon-bonded units of the following structures T1 (-47ppm~-52ppm), T2 (-55ppm~-61ppm), and T3 (-62ppm~-72ppm).

[Wherein, R is hydrogen, methyl, ethyl, or phenyl, and X is (a) or (b) below, which may be the same or different, and at least one X in each structure is (a). The X will be described later.

(a) 3,4-epoxycyclohexyl, or a group having a 3,4-epoxycyclohexyl at the end of an organic group having 1 to 6 carbon atoms

(b) Organic groups with 1 to 6 carbon atoms]

The characteristics of the component (C) are as follows: it contains not only the signal indicating the T3 structure that can be observed in general silicone resins, but also the T2 structure and T1 structure. By having not only the T3 structure but also such T2 structure and T1 structure, it has heat resistance or chemical resistance derived from the T3 structure, and can improve the solubility in organic solvents or compatibility when used with other resins, and can widely design the required characteristics of the hardened material, and can also be applied to various processing processes used in photosensitive resin compositions. Moreover, for these structures T1~structure T3, the area ratio of the signal is preferably T1:T2:T3=0~1:1~10:1~100, preferably 0~1:1~10:1~50.

Furthermore, the component (C) preferably contains not only the T structure but also the following structure D1 showing a signal at -9ppm to -13ppm and the following structure D2 showing a signal at -15ppm to -24ppm in the ²⁹ Si-NMR spectrum. By having such specified structures D1 and D2, compatibility with organic solvents or other epoxy resins etc. is improved, which is preferred in this respect.

[In structure D1~structure D2, R is hydrogen, methyl, ethyl or phenyl, and Y is (a) or (b) described above, which may be the same or different in each structure.]

Furthermore, the area ratio of the signal of the T structure and the D structure is preferably (T1+T2+T3):(D1+D2)=10~1:5~0. From the perspective of low hygroscopicity of the cured product, it is more preferably (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 a siloxane resin in such a way that a large amount of T structure is introduced. In addition, for example, if there is a need to control various physical properties of the cured product and it is necessary to improve compatibility with other epoxy resins, it is necessary to design a siloxane resin containing a certain amount of D structure.

As a representative structure of component (C), the molecule has a group represented by the following formula (4) or formula (5).

[Chemistry 10]

In the above formula (4) and formula (5), j, k, s, and t satisfy

1≦j+k≦7(j≧0,k≧1)…(i)

2≦s+t≦100(s≧1,t≧1)…(ii)

Here, from the perspective of compatibility with other compounds, j+k is preferably 1 or more, and from the perspective of chemical resistance and adhesion of the coating, j+k is preferably 7 or less. That is, it is preferable to have a ring structure of an appropriate size that can satisfy such characteristics. j+k is more preferably 1 to 6, and further preferably 1 to 4. In addition, from the perspective of molecular weight control and compatibility with other compounds, s+t is preferably 2 or more and 100 or less. That is, it is preferable to be a compound in which a ring structure and a chain structure are bonded at an appropriate ratio, and the s+t is more preferably 2 to 99, and further preferably 3 to 75. * indicates a bond, and when linked, it constitutes a Si-O-Si bond.

X in formula (4) and formula (5) is the aforementioned (a) or (b), which may be the same or different, and include more than one (a). Furthermore, (a) only needs to exist somewhere in X in the T structure or Y in the D structure, and preferably, there are multiple (a)s, which exist in both the T structure and the D structure.

In the group having 3,4-epoxycyclohexyl at the end of the organic group having 1 to 6 carbon atoms, the "organic group having 1 to 6 carbon atoms" may include branched alkyl groups, cycloalkyl groups, phenyl groups, etc. The carbon number is preferably 1 to 4, and more preferably 1 to 3. Examples of such organic groups include methyl, ethyl, various propyl groups, various butyl groups, and cycloalkyl groups such as cyclopropyl groups. Furthermore, the so-called "various" refers to various isomers including normal-, second-, third-, and iso-.

In addition, as examples of when X in formula (4) and formula (5) is a alkyl group having 1 to 3 carbon atoms, methyl and ethyl groups are preferred.

Multiple Xs may be the same or different. From the perspective of curability, it is preferred that at least one X contains a 3,4-epoxycyclohexyl group, and that the group contains a 3,4-epoxycyclohexyl group at the end of an organic group with 1 to 6 carbon atoms. It is more preferred that the group containing a 3,4-epoxycyclohexyl group at the end of an organic group with 1 to 6 carbon atoms is 15 mol% or more relative to 100 mol% of Si, and more preferably 30 mol% or more. As the group containing a 3,4-epoxycyclohexyl group at the end of an organic group with 1 to 6 carbon atoms, β-(3,4-epoxycyclohexyl)ethyl is preferred.

On the other hand, R' in formula (4) and formula (5) is a hydroxyl group, a carbonyl 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).

Here, _RX in formula (6) is a hydroxyl group, an alkyl group having 1 to 3 carbon atoms, a phenyl group, a methoxy group, or an ethoxy group, and X is (a) or (b). Preferably, * represents a bond, and when linked, it forms a Si-O-Si bond, and the number of repeating units is 0 to 15000.

R' in formula (4) and formula (5) may be the same or different. When all R' are hydroxyl groups, the storage stability is poor and the low hygroscopicity of the cured film may be impaired depending on the formulation composition. Therefore, it is preferred that the content of hydroxyl groups is 30 mol% or less relative to 100 mol% of Si, and groups other than hydroxyl groups are more preferred.

In the above R' and _RX, the alkyl group having 1 to 3 carbon atoms is more preferably a methyl group or an ethyl group, whereby a cured film having high heat resistance can be obtained.

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

The weight average molecular weight is expressed as the polystyrene-equivalent weight average molecular weight (Mw) obtained by gel permeation chromatography (GPC). When Mw is less than 750, a film (cured product) with low crosslinking density and poor chemical resistance is formed, and it is easy to remain in the coating as unreacted products and become a factor that deteriorates the degassing characteristics of the coating. When Mw is greater than 20,000, there is a tendency for the flatness of the film (cured product) to deteriorate or the compatibility with other compounds to deteriorate. The preferred Mw is 1,000 to 15,000.

In addition, when the epoxy equivalent is 350 g/eq or more, the content of reactive groups decreases, the curability is insufficient, and there is a tendency for the crosslinking density to decrease, so the properties of the cured film such as chemical resistance deteriorate. It is preferred that the molecular weight is 150 or more and less than 350.

The photosensitive resin composition of the present invention can obtain a cured film with low hygroscopicity by containing the component (C) as described above. The details of the reason are not certain, but it is presumed that the epoxy group of conventional general siloxane epoxy resins is a structural unit derived from a glycidyl group with high hydrophilicity, while the siloxane epoxy resin containing a 3,4-epoxyepoxyhexyl group is a cyclohexyl epoxy group with high hydrophobicity. It is further speculated that the reason is that the general siloxane epoxy resin in the past is easy to generate or retain silanol groups (the group representing a hydroxyl group in R' in the above formula (4) and formula (5)) when manufactured by hydrolysis condensation, while the siloxane epoxy resin containing 3,4-epoxyhexyl groups in the present invention has fewer silanol groups.

Component (C) can be produced, for example, by the following method (c) or (d). That is, it can be produced by a known method such as (c) a method of hydrolyzing and condensing an alkoxysilane compound having a specific organic group or a mixture of an alkoxysilane having a specific organic group and other silane compounds in the presence of an appropriate organic solvent, acid and water, or (d) a method of adding a compound having a specific organic group and a double bond group to a polysiloxane having a hydrosilane structure, but method (c) is general and easy, and therefore preferred.

In the case of production by the method (c), it can be exemplified as follows: using a trialkoxysilane represented by the general formula Si(X ₁ )(OR ₁₀ ) ₃ as the alkoxysilane compound and hydrolyzing or hydrolytically condensing it, or hydrolyzing or hydrolytically condensing the Si(X ₁ )(OR ₁₀ ) ₃ and a dialkoxysilane represented by the general formula Si(X ₂ ) ₂ (OR ₁₁ ) _2. Wherein, X ₁ is a group represented by (a) or (b) and may be the same or different, but preferably one or more of (a) is included, wherein (a) 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 represented by (a) or (b) and may be the same or different, but one or more of (b) is included. _R10 and _R11 are independently an alkyl group having 1 to 3 carbon atoms or a phenyl group.

For this reaction, it is preferable to perform hydrolysis condensation under acidic conditions. 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 required for hydrolysis condensation. The amount of water is sufficient as long as it is more than the amount required for hydrolysis relative to the hydrolyzable groups of the silane compound, but it is preferably added in a manner of 0.3 times the molar amount to 1.5 times the number of hydrolyzable groups (theoretical amount).

Examples of the trialkoxysilane include methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltripropoxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltripropoxysilane, isobutyltrimethoxysilane, n-hexyltriethoxysilane, n-octyltrimethoxysilane, Silane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyl Triethoxysilane, p-phenylenediamine trimethoxysilane, p-phenylenediamine triethoxysilane, 3-glycidyloxypropyl trimethoxysilane, 3-glycidyloxypropyl triethoxysilane, 8-octenyl trimethoxysilane, 8-glycidyloxyoctyl trimethoxysilane, 8-methacryloyloxyoctyl trimethoxysilane, 2-(3,4-epoxy Trialkoxysilanes such as 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 are preferred. Among these, trialkoxysilanes having a 3,4-epoxycyclohexyl group are preferably used.

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, ,4-epoxycyclohexyl)ethylmethyldipropoxysilane, 2-(3,4-epoxycyclohexyl)diethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)diethyldiethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldipropoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyldipropoxysilane, ethylmethyldimethoxysilane, ethylmethyldiethoxysilane, ethylmethyldipropoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane and other dialkoxysilane compounds, etc.

Furthermore, these trialkoxy or dialkoxy silane compounds may be used alone or in combination of two or more.

In the present invention, the content of the 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 hygroscopicity of the cured product becomes sufficiently high. On the other hand, as its upper limit, it 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-dimethylaminoacetophenone, dichloroacetophenone, trichloroacetophenone, and p-tert-butylacetophenone; benzophenones such as benzophenone, 2-chlorobenzophenone, and p-, p-bis(dimethylaminobenzophenone); benzoyl, benzoin, benzoin methyl ether, Benzoin ethers such as benzoin isopropyl ether and benzoin isobutyl ether; α-aminophenyl alkyl ketones such as 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinylpropane-1-one and 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1; 2-(o-chlorophenyl)-4,5-phenylbiimidazole, 2-(o-chlorophenyl)-4,5-di(m-methyl)- Biimidazole compounds such as 2-(trichlorophenyl)-4,5-diphenylbiimidazole, 2-(trichlorophenyl)-4,5-diphenylbiimidazole, 2-(trimethoxyphenyl)-4,5-diphenylbiimidazole, and 2,4,5-triarylbiimidazole; halogenated methylthiazole compounds such as 2-trichloromethyl-5-phenylvinyl-1,3,4-oxadiazole, 2-trichloromethyl-5-(p-cyanostyryl)-1,3,4-oxadiazole, and 2-trichloromethyl-5-(p-methoxyphenylvinyl)-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, 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-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(3,4,5 Halogenated methyl-S-triazine compounds such as 2-(4-methylthiophenylphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 1,2-octanedione, 1-[4-(phenylthio)phenyl]-,2-(O-benzoyl oxime), 1-(4-phenylthiophenyl)- O-acyl oxime compounds such as 1-(4-methylphenyl)butane-1,2-dione-2-oxime-O-benzoate, 1-(4-methylphenyl)butane-1,2-dione-2-oxime-O-acetate, 1-(4-methylphenyl)butane-1-one oxime-O-acetate; benzoyl dimethyl ketal, thiothione, 2-chlorothiothione, 2,4-diethylthiothione, 2-methylthiothione Sulfur compounds such as thiophene, 2-isopropylthiophene; anthraquinones such as 2-ethylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-diphenylanthraquinone; organic peroxides such as azobisisobutyronitrile, benzoyl peroxide, isopropylbenzene peroxide, thiol compounds such as 2-butylbenzimidazole, 2-butylbenzoxazole, 2-butylbenzothiazole; tertiary amines such as triethanolamine and triethylamine, etc. Among them, especially when a photosensitive resin composition containing a colorant is prepared, O-acyl oxime compounds (including ketone oxime) are preferred. In addition, only one of these photopolymerization initiators can be used alone, or two or more can be used in combination. Furthermore, the photopolymerization initiator of the present invention contains a sensitizer.

The photosensitive resin composition of the present invention preferably contains 0.1 to 10 parts by mass of the photopolymerization initiator (D) relative to 100 parts by mass of the total of the components (A) and (B), and more preferably 1 to 5 parts by mass. If the amount is less than 0.1 parts by mass, the sensitivity cannot be fully obtained. If the amount is more than 10 parts by mass, the conical shape (the shape of the film thickness direction of the cross section of the developed pattern) will not become sharp, and it is easy to produce halo in a stretched and drooping state, and decomposition gas may be generated when exposed to high temperature in the subsequent steps.

<(E) Non-silicone compounds>

The photosensitive resin composition of the present invention may further include a non-silicone compound that does not include a siloxane structure. Such a non-silicone compound can be used without particular restrictions as long as it is compatible with the siloxane resin. By including the non-silicone compound, properties such as flatness or hardness can be further improved, or the viscosity can be adjusted, so it is preferred. As such a non-silicone compound, a compound that does not include a siloxane skeleton and has an epoxy group or a polymerizable unsaturated bond is used. Among these compounds, as long as they can be uniformly mixed with the addition of a solvent and are liquid at room temperature or solid at room temperature, they can be used without particular restrictions. Specific compounds are exemplified below.

Examples are given from compounds that do not contain a siloxane skeleton and have an epoxy group.

As chain aliphatic epoxy compounds that are liquid at room temperature, there are: trihydroxymethylpropane triglycidyl ether, trihydroxymethylethane triglycidyl ether, monoglycidyl ether or diglycidyl ether of branched alkyl esters, FOLDI series manufactured by Nissan Chemical, etc. Such chain aliphatic epoxy compounds increase the crosslinking density by reacting with the hardener, thereby contributing to the improvement of heat resistance. In particular, epoxy compounds with a viscosity of 30mPa.s~500mPa.s (25°C) can be preferably used.

In addition, examples of aliphatic 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 or bis(3,4-epoxycyclohexylmethyl)adipate, hydrogenated bisphenol A diglycidyl ether, 1,4-cyclohexanedimethanol-bis(3,4-epoxycyclohexanecarboxylate), etc. Epoxy compounds with a viscosity of 50mPa.s to 3500mPa.s (25°C) can be preferably used.

In addition, as aromatic epoxy compounds that are liquid at room temperature, low molecular weight compounds such as bisphenol A type epoxy compounds and bisphenol F type epoxy compounds can be listed.

In addition, as the epoxy compounds having a triazine skeleton that are liquid at room temperature, there can be listed polyfunctional epoxy compounds having a triazine skeleton (TEPIC-PAS, TEPIC-VL, TEPIC-UC, etc. manufactured by Nissan Chemical Co., Ltd.).

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

By using these liquid epoxy resins, the flatness of the film (cured product) can be further improved.

On the other hand, as the epoxy compound which is solid at room temperature, 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, 1,2-epoxy-4-(2-oxoheterocyclopropyl)cyclohexane adducts of 2,2-bis(hydroxymethyl)-1-butanol (e.g., "EHPE3150" manufactured by Daicel Corporation) and the like can be used without particular limitation. The epoxy compounds that are solid at room temperature include epoxides, copolymers of (meth)acrylates containing glycidyl (meth)acrylate as an essential component, epoxidized polybutadiene (e.g., "NISSO-PB.JP-100" manufactured by Nippon Soda Co., Ltd.), trifunctional epoxy compounds having a triazine skeleton (TEPIC SC-G, TEPIC S, TEPIC SS, TEPIC SP, etc. manufactured by Nissan Chemical Co., Ltd.), and the like. In addition, epoxy compounds that are waxy or finely divided at room temperature and have a low melting point, i.e., ε-caprolactam modified products of (3',4'-epoxyepoxyhexylmethyl) 3,4-epoxyepoxyhexanecarboxylate (TTA2081, TTA2083 manufactured by Tetrachem Co., Ltd.), etc. can also be used.

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

The following examples include (meth)acrylates other than glycidyl (meth)acrylate and other polymerizable unsaturated compounds used in the copolymer, but are not limited to these.

(Meth)acrylic acid esters can be obtained by condensing (meth)acrylic acid (the so-called (meth)acrylic acid refers to acrylic acid or methacrylic acid) with an alcohol (R ₁ OH) component. As the (R ₁ OH) component, a known component can be used without particular limitation. Specific examples of _R1 include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, t-butyl, pentyl, isopentyl, neopentyl, t-pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, cyclopropyl, cyclopentyl, cyclopentylethyl, cyclohexyl, cyclohexylmethyl, 4-methylcyclohexyl, adamantyl, isobornyl, dicyclopentanyl, dicyclopentenyl, vinyl, allyl, ethynyl, phenyl, tolyl, mesityl, naphthyl, anthracenyl, phenanthryl, benzyl, 2-phenylethyl, 2-phenylvinyl and the like saturated or unsaturated monovalent hydrocarbon groups, and pyridyl, piperidinyl, etc. The alkyl or heterocyclic group may be a structure in which a halogen atom, a carbonyl group, a thiocarbonyl group, a nitro group, a silane group, an ether group, a thioether group, an ester group, a thioester group, a dithioester group, a carbamate group, a thiocarbamate group, a urea group, a thiourea group, or the like is introduced as a substituent at any position. Such a monovalent group can be appropriately selected according to the structure of the target (meth)acrylate copolymer. In terms 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. Furthermore, the saturated or unsaturated monovalent hydrocarbon group may be a hydrocarbon group having a branched structure or a ring structure, and may be substituted by any substituent. Among them, the substituent preferably does not have a reactive structure such as an acidic group and an amide bond.

As other polymerizable unsaturated compounds, styrene and its derivatives can be cited. As specific compounds, compounds obtained by introducing alkyl groups, halogen atoms, hydroxyl groups, etc. into the aromatic rings of styrene, α-methylstyrene, or p-styrene can be used.

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

Among the copolymers exemplified above, preferred examples include copolymerization of glycidyl methacrylate, alkyl methacrylate (C1 to C4 alkyl), or further copolymerization of styrene, and having a softening point (Tg) of 10°C to 90°C. The more preferred range of Tg of the copolymer is 40°C to 90°C.

Among the epoxy compounds that are solid at room temperature, in particular, from the perspective of further improving heat resistance and low gas generation, the epoxy compounds represented by the following general formula (7) have an average value of l of 0 to 2.

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

The epoxy compound of the general formula (7) may be a bisphenol fluorene epoxy compound or a bis-naphthol fluorene epoxy compound. The epoxy compound is a component that has a relatively small effect on the viscosity of the photosensitive resin composition and is effective in imparting low gas generation or heat resistance. In particular, in order to impart low gas generation, a bis-naphthol fluorene epoxy resin is more preferred.

The average value of l in the general formula (7) can be 0 to 2. If it is greater than 0, the solubility can be improved, and if it exceeds 2, there is a tendency 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 based on the epoxy equivalent. For example, in the case of a bis-naphthol fluorene type epoxy compound, it can be calculated based on

(Epoxy equivalent)×2=(average value of l)×506.6+562.7

To calculate. In addition, in the case of bisphenol fluorene type epoxy compounds, it can be calculated according to

(Epoxy equivalent)×2=(average value of l)×406.5+462.5

To figure it out.

The epoxy compound of the general formula (7) can be synthesized by a known method such as the method described in Japanese Patent Laid-Open No. 9-328534. Generally, the most 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 set to the desired value by adjusting the molar ratio of the raw material compounds during synthesis or adjusting the reaction conditions.

Next, a compound having no siloxane skeleton and having a polymerizable unsaturated bond is exemplified as the component (E). Any epoxy acrylate compound obtained by reacting a monocarboxylic acid compound having a polymerizable unsaturated bond, such as acrylic acid or methacrylic acid, with the exemplified epoxy compound having no siloxane skeleton can be used without particular limitation as long as it can be uniformly mixed with the solvent. Furthermore, as other examples of monocarboxylic acid compounds having polymerizable unsaturated bonds, when (meth)acrylate represents acrylate or methacrylate, there can be listed half ester of 2-hydroxyethyl (meth)acrylate and succinic anhydride, half ester of 2-hydroxyethyl (meth)acrylate and phthalic anhydride, half ester of 2-hydroxyethyl (meth)acrylate and cyclohexane-1,2-dicarboxylic anhydride, 4-vinylbenzoic acid, etc. In addition, polymerizable monomers having polymerizable unsaturated bonds can be used without particular limitation as long as they can be uniformly mixed under the addition of a solvent.

Examples of polymerizable monomers include (meth)acrylates having a hydroxyl group such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate, or 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, trihydroxymethylpropane tri(meth)acrylate, trihydroxymethylethane tri(meth)acrylate, pentaerythritol di(meth)acrylate, and the like. (Meth)acrylates such as (meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, glycerol (meth)acrylate, sorbitol penta(meth)acrylate, dipentaerythritol penta(meth)acrylate, or dipentaerythritol hexa(meth)acrylate, sorbitol hexa(meth)acrylate, phosphazene epoxide-modified hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, etc., and one or more of these can be used.

In the present invention, it is preferred to contain 3% by mass or more of the above-mentioned non-silicone type compound, and more preferably 5% by mass or more. On the other hand, as its upper limit, it is preferably 20% by mass or less, and more preferably 15% by mass or less. If it is within the above range, the flatness or pattern linearity can be improved without damaging the moisture absorption of the cured product or the pattern adhesion and pattern fineness.

<Other ingredients>

The photosensitive resin composition of the present invention may contain other optional components as needed, for example, it may contain a coloring material, a filler, a resin, an additive, etc. Here, as coloring materials, there can be listed: dyes, organic pigments, inorganic pigments, carbon black pigments, etc., as fillers, there can be listed silica, talc, etc., as resins, there can be listed: vinyl resins, polyester resins, polyamide resins, polyimide resins, polyurethane resins, polyether resins, melamine resins, etc., as additives, there can be listed: dispersants, surfactants, silane coupling agents, viscosity adjusters, wetting agents, defoaming agents, antioxidants, ultraviolet absorbers, thermal free radical initiators, etc. As these arbitrary components, known compounds can be used without particular restrictions.

As coupling agents, for example, silane coupling agents (3-(glycidyloxy)propyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, and 3-ureidopropyltriethoxysilane, etc.), titanium-based coupling agents, and aluminum-based coupling agents can be used. As thermal radical initiators, examples include azo-based initiators such as 2,2-azobisisobutyronitrile, dimethyl 2,2-azobis-2-methylpropionate, 1,1'-azobis(1-acetyloxy-1-phenylethane), or peroxides such as benzoyl peroxide.

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

As the solvent, a known compound can be used. For example, ester solvents (butyl acetate, cyclohexyl acetate, etc.), ketone solvents (methyl isobutyl ketone, cyclohexanone, etc.), ether solvents (diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, etc.), alcohol solvents (3-methoxybutanol, ethylene glycol mono-tert-butyl ether, etc.), aromatic solvents (toluene, xylene, etc.), aliphatic solvents, amine solvents, and amide solvents can be used without particular limitation. In terms of safety, ester or ether solvents having a propylene glycol skeleton are preferred, 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. In addition, 3-methoxybutyl acetate, 3-methoxy-3-methylbutyl acetate, and 1,3-butanediol diacetate, which have structures similar to these, are also preferred.

In addition, the photosensitive resin composition of the present invention may optionally use a curing agent of an epoxy compound selected from the group consisting of polycarboxylic acids, polycarboxylic acid anhydrides and polycarboxylic acid pyrolyzable esters, or a known curing accelerating compound such as a curing accelerator, a curing catalyst or a latent curing agent for the epoxy compound. When a curing agent is used, it is preferably prepared in an amount of 1% to 20% by mass, more preferably 5% to 10% by mass, relative to the total mass of the solid components of the composition. If the amount is less than 1%, the curing agent is ineffective, and if it exceeds 20% by mass, the remaining curing agent that does not contribute to curing will have an adverse effect on gas generation. In addition, when using a compound that accelerates curing, it is preferably formulated in an amount of 0.005% to 2% by mass relative to the total mass of the solid components of the composition, and more preferably 0.01% to 1% by mass. If it is less than 0.005%, it lacks the effect as an accelerator, and if it exceeds 2%, sufficient storage stability cannot be obtained when the photosensitive resin composition is made into a solution, or it has an adverse effect on coloring when heated.

The polycarboxylic acid used as the hardener is a compound having two or more carboxyl groups in one molecule, for example, 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, etc.

In addition, the anhydride of the polycarboxylic acid used as the curing agent can be the anhydride of the polycarboxylic acid exemplified above, which can be an intermolecular anhydride, and generally an anhydride that is ring-closed within the molecule is used. As a preferred anhydride, trimellitic anhydride can be exemplified.

Furthermore, the thermally decomposable esters of polycarboxylic acids used as hardeners include tert-butyl esters, 1-(alkyloxy)ethyl esters, and 1-(alkylalkyl)ethyl esters of the polycarboxylic acids exemplified above (wherein the alkyl group described here represents a saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may have a branched structure or a ring structure and may be substituted by any substituent), etc.

In addition, as a hardener, a polymer or copolymer having two or more carboxyl groups may also be used. The carboxyl group of the polymer or copolymer may be an anhydride or a thermally decomposable ester. Examples of such polymers or copolymers include polymers or copolymers containing (meth)acrylic acid as a structural component, copolymers containing maleic anhydride as a structural component, compounds formed by reacting tetracarboxylic dianhydride with diamine or diol and ring-opening the anhydride, etc.

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

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

The photosensitive resin composition of the present invention can be formed by curing it by the following photodevelopment method. The following methods can be listed: First, the photosensitive resin composition is applied to a glass substrate, a plastic substrate, etc. and a substrate on which a pixel pattern of a color filter or an electrode pattern for pixel driving such as a thin film transistor (TFT) is formed, and then the solvent is dried (pre-baked), and a photoresist is placed on the film obtained in the above manner, and ultraviolet rays are irradiated to cure the exposed part, and then an alkaline aqueous solution is used to develop the unexposed part to form a pattern, and then post-baking (heat calcination) is performed as post-hardening.

As a transparent substrate for coating a solution of a photosensitive resin composition, in addition to a glass substrate, a substrate on which a transparent electrode such as indium tin oxide (ITO) or gold is evaporated or patterned on a transparent film (for example, polycarbonate, polyethylene terephthalate, polyether sulfide, etc.) can be exemplified. As a method for coating a solution of a photosensitive resin composition, in addition to the well-known solution immersion method and spraying method, any method such as a method using a roller coater, a land coater, or a rotator can also be used. Using these methods, after coating to the desired thickness, the solvent is removed (pre-baking) to form a film. Pre-baking is performed by heating using an oven, a hot plate, etc. The heating temperature and heating time in pre-baking can be appropriately selected according to the solvent used, for example, at a temperature of 60℃~110℃ for 1 minute to 5 minutes.

The exposure after pre-baking is performed using a UV exposure device, and the exposure is performed through the photoresist, so that only the part of the resist corresponding to the pattern is photosensitized. The exposure device and its exposure conditions can be appropriately selected, and the exposure is performed using a light source such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a metal halide lamp, and a far ultraviolet lamp, so that the black resist in the coating is photocured with a photosensitive resin composition.

Alkaline development after exposure is performed for the purpose of removing the anti-etching agent in the unexposed part, and the desired pattern is formed by the development. As a developer suitable for the alkaline development, for example, aqueous solutions of carbonates of alkali metals or alkali earth metals, aqueous solutions of hydroxides of alkali metals, etc. can be listed. In particular, it is preferable to use a weak alkaline aqueous solution containing 0.05% to 3% by mass of carbonates such as sodium carbonate, potassium carbonate, and lithium carbonate, and develop at a temperature of 23°C to 28°C. A commercially available developer or ultrasonic cleaning machine can be used to accurately form a fine image.

After development, it is preferred to perform heat treatment (post-baking) at a temperature of 80°C to 250°C (set to not exceed the heat resistance temperature of the substrate) and for 20 minutes to 90 minutes. The post-baking is performed for the purpose of improving the adhesion between the patterned resin film and the substrate. It is performed by heating using an oven, a hot plate, etc., as in pre-baking. The more preferred range of heat treatment conditions for post-baking is a temperature of 180°C to 230°C and a heating time of 30 minutes to 60 minutes. The patterned resin film of the present invention is formed by using each step of the above light development method.

The photosensitive resin composition of the present invention is useful for forming solder resist, anti-etching agent, etching anti-etching agent, or insulating film for multi-layering of wiring substrates carrying semiconductor elements, semiconductor gate insulating film, protective film and planarizing film for color filter, partition material for forming organic EL pixels (for the case of forming RGB by inkjet method, etc.), insulating film for touch screen, etc., and can be used for components for display devices such as liquid crystal or organic EL, for photographic elements, and for touch screens that include these resin film patterns as structural elements.

[Implementation example]

The present invention is described in more detail below through examples, but the present invention is not limited to these. The preparation example of the photosensitive resin composition of the present invention is described, and the evaluation results of the coating formed using the photosensitive resin composition are described.

First, the synthesis example of (A) an alkali-soluble resin containing a polymerizable unsaturated group is shown. The evaluation of the resin in the synthesis example is performed as follows.

[Solid content concentration]

1 g of the resin solution obtained in the synthesis example was immersed in a glass filter [weight: W ₀ (g)] and weighed [W ₁ (g)]. From the weight after heating at 160°C for 2 hours [W ₂ (g)], the molecular weight was determined according to the following formula.

Solid content concentration (weight %) = 100 × (W ₂ -W ₀ ) / (W ₁ -W ₀ )

[Acid value]

The resin solution was dissolved in dioxane and titrated in a 1/10N-KOH aqueous solution using a potentiometric titrator (manufactured by Hiranuma Sangyo Co., Ltd., trade name COM-1600) to obtain the result.

[Molecular weight]

The weight average molecular weight (Mw) was determined by using colloid permeation chromatography (GPC) [trade name: HLC-8220GPC manufactured by Tosoh Corporation, solvent: tetrahydrofuran, column: TSKgelSuperH-2000 (2 columns) + TSKgelSuperH-3000 (1 column) + TSKgelSuperH-4000 (1 column) + TSKgelSuper-H5000 (1 column) [manufactured by Tosoh Corporation], temperature: 40 ℃, speed: 0.6 ml/min] and converted to standard polystyrene [PS-Oligomer Kit manufactured by Tosoh Corporation] .

[ ²⁹ Si-NMR measurement conditions]

Device name: JNM-ECA400 manufactured by NEC Corporation

Observed nucleus: ²⁹ Si

Observation frequency: 79.43MHz

Measuring temperature: room temperature

Determination solvent: CDCl ₃

Pulse width: 8.75μsec (90°)

Pulse repetition time: 5.0sec

Cumulative times: 11,000 times

Sample concentration (sample/test solvent/buffering reagent): 200mg/0.7ml/10mg

Mitigating agent: Cr(acac) ₃

In addition, the abbreviations used in the synthesis examples are as follows.

BPFE: Bisphenol fluorene type epoxy compound〔Reaction product of 9,9-bis(4-hydroxyphenyl)fluorene and chloromethyloxycyclopropane. Epoxide equivalent 250g/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: Azobis(isobutyronitrile)

GMA: Glycidyl Methacrylate

TPP: triphenylphosphine

TBPC: 2,6-di-tert-butyl-p-cresol

<(A) Synthesis of alkali-soluble resin containing polymerizable unsaturated groups>

[Synthesis Example 1]

BPFE 114.4 g (0.23 mol), AA 33.2 g (0.46 mol), PGMEA 157 g and TEAB 0.48 g were placed in a 500 ml four-necked flask equipped with a reflux cooler, and stirred for 20 hours at 100°C to 105°C for reaction. Then, BPDA 35.3 g (0.12 mol) and THPA 18.3 g (0.12 mol) were placed in the flask, and stirred for 6 hours at 120°C to 125°C to obtain an alkali-soluble resin (A)-1 containing a polymerizable unsaturated group. The solid content concentration of the obtained resin solution was 56.1% by mass, the acid value (solid content conversion) was 103 mgKOH/g, and the Mw obtained by GPC analysis was 3600 (alkaline-soluble resin A-1 containing polymerizable unsaturated groups).

[Synthesis Example 2]

In a 1000ml four-necked flask with a nitrogen inlet and reflux tube, 51.65g of MAA (0.60 mol), 36.04g of MMA (0.36 mol), 40.38g of CHMA (0.24 mol), 5.91g of AIBN, and 360g of PGMEA were placed, and stirred at 80℃~85℃ and nitrogen flow for 8 hours to polymerize. Then, 61.41g of GMA (0.43 mol), 2.27g of TPP, and 0.086g of TBPC were placed in the flask, and stirred at 80℃~85℃ for 16 hours to obtain an alkali-soluble resin (A)-2 containing a polymerizable unsaturated group. The solid content concentration of the obtained resin solution was 35.7% by mass, the acid value (solid content conversion) was 50 mgKOH/g, and the Mw obtained by GPC analysis was 19600 (alkaline-soluble resin A-2 containing polymerizable unsaturated groups).

<(C) Synthesis of Siloxane Epoxy Resin>

[Synthesis Example 3]

In a reaction vessel including a stirring device, a dropping funnel, a thermometer and a stirrer, 25.0 g of 2-(3,4-epoxyhexyl)ethyltrimethoxysilane and 150.0 g of toluene were placed. After complete dissolution, 1.25 g of p-toluenesulfonic acid monohydrate as an acid catalyst was further mixed and stirred at room temperature for 30 minutes. 3.3 g of water was then added dropwise and stirred for 24 hours. After the reaction was completed, the mixture was washed with an aqueous solution of NaHCO ₃ , the organic layer was dried and filtered with MgSO ₄ , and the 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. Mw is 4100 (Silicone Epoxy Resin C-1).

[Synthesis Example 4]

In a reaction vessel including a stirring device, a dropping funnel, a thermometer and a stirrer, 20.0 g of 2-(3,4-epoxyhexyl)ethyltrimethoxysilane, 5.0 g of 2-(3,4-epoxyhexyl)ethylmethyldiethoxysilane and 150.0 g of toluene were placed. After complete dissolution, 1.25 g of p-toluenesulfonic acid monohydrate as an acid catalyst was further mixed and stirred at room temperature for 30 minutes. 3.1 g of water was then added dropwise and stirred for 24 hours. After the reaction was completed, the mixture was washed with an aqueous solution of NaHCO ₃ , the organic layer was dried and filtered with MgSO ₄ , and the 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. Mw was 3200 (Silicone Epoxy Resin C-2).

[Synthesis Example 5]

In a reaction vessel including a stirring device, a dropping funnel, a thermometer and a stirrer, 12.5 g of 2-(3,4-epoxyhexyl)ethyltrimethoxysilane, 12.5 g of 2-(3,4-epoxyhexyl)ethyltriethoxysilane and 150.0 g of toluene were placed. After complete dissolution, 1.25 g of p-toluenesulfonic acid monohydrate as an acid catalyst was further mixed and stirred at room temperature for 30 minutes. 3.0 g of water was then added dropwise and stirred for 24 hours. After the reaction was completed, the mixture was washed with an aqueous solution of NaHCO ₃ , the organic layer was dried and filtered with MgSO ₄ , and the volatile matter was 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 and the Mw was 5000 (Silicone Epoxy Resin C-3).

[Synthesis Example 6]

7.5 g of 2-(3,4-epoxyhexyl)ethyltriethoxysilane, 17.5 g of 2-(3,4-epoxyhexyl)ethylmethyldiethoxysilane, and 150.0 g of toluene were placed in a reaction container including a stirring device, a dropping funnel, a thermometer, and a stirrer. After complete dissolution, 1.25 g of p-toluenesulfonic acid monohydrate as an acid catalyst was further mixed and stirred at room temperature for 30 minutes. 2.6 g of water was then added dropwise and stirred for 24 hours. After the reaction was completed, the mixture was washed with an aqueous solution of NaHCO ₃ , the organic layer was dried and filtered with MgSO ₄ , 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. Mw was 3800 (Silicone Epoxy Resin C-4).

[Synthesis Example 7]

In a reaction vessel including a stirring device, a dropping funnel, a thermometer and a stirrer, 25.0 g of 2-(3,4-epoxyhexyl)ethyltriethoxysilane and 15.0 g of toluene were placed. After complete dissolution, 1.25 g of p-toluenesulfonic acid monohydrate as an acid catalyst was further mixed and stirred at room temperature for 30 minutes. 2.8 g of water was then added dropwise and stirred for 24 hours. After the reaction was completed, the mixture was washed with an aqueous solution of NaHCO ₃ , the organic layer was dried and filtered with MgSO ₄ , and the 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. Mw is 3500 (Silicone Epoxy Resin C-5).

[Synthesis Example 8]

In a reaction vessel including a stirring device, a dropping funnel, a thermometer and a stirrer, 12.5 g of 2-(3,4-epoxyhexyl)ethyltrimethoxysilane, 12.5 g of dimethyldiethoxysilane and 150.0 g of toluene were placed. After complete dissolution, 1.25 g of p-toluenesulfonic acid monohydrate as an acid catalyst was further mixed and stirred at room temperature for 30 minutes. 3.7 g of water was then added dropwise and stirred for 24 hours. After the reaction was completed, the mixture was washed with an aqueous solution of NaHCO ₃ , the organic layer was dried and filtered with MgSO ₄ , and the volatile matter was 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. Mw was 2900 (Silicone Epoxy Resin C-6).

[Synthesis Example 9]

In a reaction vessel including a stirring device, a dropping funnel, a thermometer and a stirrer, 15.0 g of 2-(3,4-epoxyhexyl)ethyltrimethoxysilane, 5.0 g of dimethyldiethoxysilane, 5.0 g of methacryloyloxypropyltrimethoxysilane and 150.0 g of toluene were placed. After complete dissolution, 1.25 g of p-toluenesulfonic acid monohydrate as an acid catalyst was further mixed and stirred at room temperature for 30 minutes. 3.5 g of water was then added dropwise and stirred for 24 hours. After the reaction was completed, the mixture was washed with an aqueous solution of NaHCO ₃ , the organic layer was dried and filtered with MgSO ₄ , and the volatile matter was 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. Mw was 2000 (Silicone Epoxy Resin C-7).

[Comparative Synthesis Example 1]

In a reaction vessel including a stirring device, a dropping funnel, a thermometer and a stirrer, 25.0 g of (3-glycidyloxypropyl)trimethoxysilane, 100.0 g of toluene and 50.0 g of 2-propanol (isopropyl alcohol, IPA) were placed. After they were completely dissolved, 7.5 g of a 5% tetramethylammonium hydroxide aqueous solution (TMAH (tetramethyl ammonium hydroxide) aqueous solution) as an alkaline catalyst was added and stirred at room temperature for 24 hours. After the reaction was completed, it was washed with a citric acid aqueous solution, the organic layer was dried with MgSO ₄ and filtered, and the 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. Mw is 28000 (silicone epoxy resin c-1).

(Preparation of photosensitive resin composition)

Prepare the photosensitive resin composition by mixing the compositions shown in Tables 1 to 4, stirring and mixing at room temperature for 3 hours, and dissolving the solid components in the solvent. The composition values are in parts by mass.

As a photosensitive resin composition, the components used in the formulation of the embodiments and comparative examples are shown below.

<(A) Alkaline soluble resin containing polymerizable unsaturated groups>

A-1: Resin solution obtained in Synthesis Example 1

A-2: Resin solution obtained in Synthesis Example 2

<(B) Photopolymerizable monomer>

B-1: A mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (trade name: DPHA manufactured by Nippon Kayaku Co., Ltd.)

<(C)Silicone 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 Hengqiao Industrial Co., Ltd., epoxy equivalent 295g/eq, Mw: 4,500)

c-1: Comparison of the siloxane epoxy resin prepared in Synthesis Example 1 (epoxy equivalent 169 g/eq, Mw: 28,000)

c-2: Siloxane epoxy resin with epoxyhexyl groups ("X-40-2669" manufactured by Shin-Etsu Chemical Co., Ltd., epoxy equivalent 191 g/eq, Mw: 383)

c-3: Siloxane epoxy resin with epoxyhexyl groups ("KR-470" manufactured by Shin-Etsu Chemical Co., Ltd., epoxy equivalent 200 g/eq, Mw: 737)

c-4: Silicone epoxy resin with methoxy, ethoxy and glycidyl groups ("X-41-1059A" manufactured by Shin-Etsu Chemical Industries, epoxy equivalent 350 g/eq, Mw: 2,500)

c-5: Siloxane epoxy resin having epoxyhexyl groups but no hydroxyl, methoxy, ethoxy or phenoxy groups ("Poly 200" manufactured by Arakawa Chemical Industries)

<(D) Photopolymerization initiator>

D-1: 1,2-octanedione, 1-[4-(phenylthio)phenyl]-,2-(O-benzoyl oxime) (manufactured by BASF, trade name: Irgacure OXE-01)

<(E) Non-silicone compounds>

E-1: Fluorene-based epoxy resin [manufactured by Nippon Steel Chemicals & Materials Co., Ltd., ESF-300C, epoxy equivalent 220g/eq~240g/eq]

E-2: 1,2-epoxy-4-(2-oxacyclopropyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol (produced by Daicel Co., Ltd., EHPE3150, epoxy equivalent: 170g/eq~190g/eq)

<Coupling agent>

F-1: 3-Glyceryloxypropyltrimethoxysilane

<Surfactant>

G-1: Megafac F-477 (manufactured by DIC Corporation)

<Solvent>

H-1: Propylene glycol monomethyl ether acetate (PGMEA)

H-2: Propylene glycol monomethyl ether (PGME)

H-3: diethylene glycol ethyl methyl ether (EDM)

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

For C-8, the area ratio of each signal is T1:T2:T3=1:7:15, D1:D2=4:26.

(Evaluation of photosensitive resin composition: flatness)

As a color filter substrate, a substrate having a black matrix and red/green/blue pixels and a mosaic pattern without blue pixels and a 2.5μm high concave-convex pattern on the pixels was prepared. The 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 coating conditions (rotation speed) were adjusted in such a way that a cured film with a film thickness of 1.5μm was obtained on the pixels. Next, ultraviolet rays of 50mJ/ ^cm2 were irradiated using an ultra-high pressure mercury lamp with an i-ray illuminance of 30mW/ ^cm2 to perform a photocuring reaction. Afterwards, 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.

The height of the unevenness at two points randomly selected on the surface of the cured film formed in a pixel-protecting manner was measured using a contact-type surface roughness meter (trade name: Fine Shape Tester ET-4000A, manufactured by Kosaka Laboratory Co., Ltd.), and a three-stage evaluation was performed based on the following criteria.

◎(Good): The height difference of the concave and convex is less than 0.20μm

○ (slightly good): The height difference of the concave and convex is more than 0.20μm and less than 0.30μm

△ (slightly bad): The height difference of the bumps exceeds 0.30μm and is less than 0.40μm

×(bad): The height difference of the bumps exceeds 0.40μm

(Evaluation of photosensitive resin composition: hygroscopicity)

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 (rotation speed) were adjusted in such a way that a cured film with a film thickness of 1.5 μm was obtained. Next, ultraviolet rays of 50 mJ/ ^cm2 were irradiated using an ultra-high pressure mercury lamp with an i-ray illumination of 30 mW/ ^cm2 to perform a photocuring reaction. Thereafter, the test piece was calcined 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 placed in a constant temperature and humidity device (Espec environmental tester SH-221) at 85°C and 85%RH for 24 hours to absorb moisture. 10 mg of the cured film of the test piece was cut and sampled, and the temperature was raised from room temperature to 150°C at 10°C/min in a nitrogen environment and kept at 150°C for 20 minutes. The weight loss at this time was defined as the weight change caused by moisture absorption of the film, and the weight was measured using a thermogravimetric analyzer (trade name: Differential Thermal Balance Dimoplus EVO2, manufactured by Rigaku Co., Ltd.), and a three-stage evaluation was performed based on the following criteria.

◎: Weight reduction is less than 0.5%

○: Weight reduction is 0.5% or more and less than 2%

△: Weight reduction is more than 2% and less than 3%

×: Weight reduction is more than 3%

(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 coating conditions (rotation speed) were adjusted in such a way that a cured film with a film thickness of 1.5 μm was obtained. Next, 50 mJ/ ^cm2 of ultraviolet light was irradiated using an ultra-high pressure mercury lamp with an i-ray illumination of 30 mW/ ^cm2 to perform a photocuring reaction. Thereafter, the test piece was calcined in a hot air oven at 230°C for 30 minutes to obtain a cured film of the photosensitive resin composition. 10 mg of the cured film of the test piece was cut and sampled, and the temperature was raised from room temperature to 120°C at 10°C/min under atmospheric air flow and maintained at 120°C for 30 minutes. Thereafter, the temperature was raised from 120°C to 230°C at 10°C/min and maintained at 230°C for 3 hours. The weight loss at this time was measured using a thermogravimetric analyzer (trade name: Differential Thermal Balance Dimoplus EVO2 manufactured by Rigaku Co., Ltd.), and a three-stage evaluation was performed based on the following criteria.

◎: Weight reduction is less than 5%

○: Weight reduction is 5% or more and less than 7%

△: Weight reduction is 7% or more and less than 10%

×: Weight reduction is more than 10%

(Evaluation of photosensitive resin composition: transparency)

A test piece with a cured film formed of a photosensitive resin composition was prepared in the same manner as the gas generation evaluation. The transmittance of the cured film at a wavelength of 400nm was measured using a spectrophotometer, and a three-stage evaluation was performed based on the following criteria.

◎: Transmittance is over 97%

○: Transmittance is above 95%

△: Transmittance is above 93% and below 95%

×: Transmittance is less than 93%

(Preparation of hardened film (coating film) for developing property evaluation)

The photosensitive resin composition shown in the table was applied to a 125 mm × 125 mm glass substrate "#1737" (manufactured by Corning) (hereinafter referred to as "glass substrate"), which had been previously cleaned by irradiating ultraviolet rays with a wavelength of 254 nm and an illumination of 1000 mJ/ ^cm2 using a low-pressure mercury lamp, using a spin coater so that the film thickness after heat curing treatment was 2.0 μm, and pre-baked at 90°C for 2 minutes using a hot plate to prepare a cured film (coating film). Next, the exposure gap is adjusted to 100 μm, a negative photoresist of 10 μm to 50 μm (with 5 μm as the scale) is covered on the cured film (coating), and 50 mJ/ ^cm2 of ultraviolet light is irradiated using an ultra-high pressure mercury lamp with an i-ray illumination of 30 mW/ ^cm2 to perform a photocuring reaction.

Next, the cured film (coating) after exposure was developed for 20 seconds using a 0.04% potassium hydroxide solution at 25°C and a spray pressure of 1 kgf/ ^cm2 from the development time (break time = BT) when the pattern began to appear, and then washed with a spray water of 5 kgf/ ^cm2 to remove the unexposed portion of the cured film (coating), thereby forming a cured film pattern on the glass substrate. Thereafter, the test piece was calcined in a hot air oven at 230°C for 30 minutes to obtain a cured film of the photosensitive resin composition.

[Development characteristics evaluation]

(Pattern adhesion)

(Evaluation method)

Observe the 20μm mask pattern after formal curing (post-baking) using an optical microscope. In addition, ○ or above is considered acceptable.

(Evaluation criteria)

◎: No peeling at all

○: Slightly peeled off

△: Partially peeled off

×: Mostly peeled off

(Linearity of pattern)

(Evaluation method)

Observe the 20μm mask pattern after formal curing (post-baking) under an optical microscope. In addition, ○ or above is considered acceptable.

(Evaluation criteria)

◎: No sawtooth is found at the edge of the pattern

○: Saw teeth are slightly visible on the edge of the pattern

△: Saw teeth are partially found on the edge of the pattern

×: Most of the saw teeth are found on the edge of the pattern

(Pattern detail)

(Evaluation method)

Observe the 10μm~50μm mask pattern after formal curing (post-baking) under an optical microscope. In addition, ○ or above is considered acceptable.

(Evaluation criteria)

◎: A pattern of 10μm~15μm is formed

○: A pattern of 16μm~24μm is formed

△: A pattern of 25μm~50μm is formed

×: No pattern formed

Claims (7)

A photosensitive resin composition, characterized in that it comprises: (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); and (D) a photopolymerization initiator, (i) having ^a In the Si-NMR spectrum, the following structure T1 shows a signal at -47ppm~-52ppm, the following structure T2 shows a signal at -55ppm~-61ppm, and the following structure T3 shows a signal at -62ppm~-72ppm, and the area ratio of the signals is T1:T2:T3=1:1~10:1~100; (ii) the weight average molecular weight is 750~20000; (iii) the epoxy equivalent 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 (a) or (b) below, which may be the same or different, and 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 end of an organic group having 1 to 6 carbon atoms; (b) an organic group having 1 to 6 carbon atoms; wherein the component (A) is an alkali-soluble resin containing a polymerizable unsaturated group represented by the 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-, fluorene-9,9-diyl 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 , and n represents an integer of 1 to 20, wherein Z represents a divalent or trivalent carboxylic acid residue, and m represents a number of 1 or 2. The photosensitive resin composition as claimed in claim 1, wherein the siloxane epoxy compound contains the following structure D1 showing a signal at -9ppm to -13ppm in the ²⁹ Si-nuclear magnetic resonance spectrum and the following structure D2 showing a signal at -15ppm to -24ppm,

In Structure D1 to Structure D2, R is hydrogen, methyl, ethyl or phenyl, and Y is (a) or (b) described above, and may be the same or different in each of Structure D1 to Structure D2. A photosensitive resin composition as described in claim 1 or claim 2, wherein the solid content of the siloxane epoxy compound is greater than 3% by mass and less than 25% by mass relative to the total mass of the solid content. The photosensitive resin composition as described in claim 1 or claim 2 contains a non-silicone compound that does not contain a siloxane skeleton and has an epoxy group or a polymerizable unsaturated bond. The photosensitive resin composition according to claim 4, wherein the non-silicone type compound is an epoxy compound represented by the following formula (7):

In formula (7), Ar is a divalent aromatic alkyl group having 6 to 12 carbon atoms; in addition, a portion of the hydrogen atoms of the divalent aromatic alkyl group represented by Ar may be substituted by a alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a halogen group; and the average value of l is 0 to 2. A cured product obtained by curing the photosensitive resin composition as described in any one of claim 1 to claim 5. A display device comprising a hardened object as described in claim 6 as a structural element.