JP2011203577A - Photosensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition for a photospacer having superior alkali developability, exposure sensitivity and resolution, a cured product thereof exhibiting superior adhesion to a substrate and superior elastic recovery characteristics even when a low temperature treatment is adopted.SOLUTION: The photosensitive resin composition is an alkali-developable negative photosensitive resin composition (Q) for a photospacer comprising a polyfunctional (meth)acrylate monomer (A) containing various acid groups or salts thereof, a siloxane compound (B) having two or more hydrolyzable alkoxy groups, and a photoradical polymerization initiator (C), wherein an acid value of the photosensitive resin composition based on the total weight of the components (A) to (C) is 10-110 KOHmg/g, and a content of carbon-carbon double bonds (C=C) in (meth)acryloyl groups in the photosensitive resin composition based on the total weight of the components (A) to (C) is 6.5-10.0 mmol/g.

Description

  The present invention relates to a negative photosensitive resin composition that is cured by light irradiation and is capable of alkali development, and a photospacer provided for maintaining a gap in a liquid crystal cell formed using the composition. . More specifically, it has excellent elastic recovery characteristics and adhesion to the substrate, and can exhibit excellent elastic recovery characteristics and adhesion to the substrate even when post-baking treatment at low temperature is adopted after curing by light irradiation. The present invention relates to a photo spacer.

In recent years, liquid crystal display devices have attracted attention, and photosensitive resins are frequently used in the manufacturing process. For example, the portion corresponding to the pixel on the color filter is a color pigment dispersion resist, and the resist is also used for the black matrix.
As a resist used for such a portion, a so-called negative resist is often used in which only a portion irradiated with light is hardened when exposed through a mask and an unexposed portion is peeled off by development.
In the liquid crystal display device technology, in order to maintain the thickness of the liquid crystal layer between the substrate on the color filter side and the substrate on the thin film transistor (TFT) side, glass or resin called a spacer is disposed inside the cell.
For example, a method of forming a columnar resin spacer on a black matrix in a lattice pattern located at a desired position, for example, between pixels by a photolithography method using a photosensitive resin and partial pattern exposure and development Has been proposed. Since such a spacer (hereinafter referred to as a photo spacer) can be formed at a position that does not overlap with the pixel, there is no problem that adversely affects display quality such as light leakage caused by mixing of liquid crystal and spacer in the pixel. The improvement of quality can be expected.

On the other hand, in recent years, as mother glass for LCD (Liquid Crystal Display) manufacture becomes larger, a drop method (ODF method) (ODF: One Drop Fill) has been proposed instead of the conventional liquid crystal inflow method (vacuum suction method). Yes. In the ODF method, after a predetermined amount of liquid crystal is dropped onto the substrate and then sandwiched between the substrates, the liquid crystal is injected, so that the number of processes and the process time can be reduced as compared with the conventional liquid crystal inflow method.

However, in the ODF system, when a predetermined amount of liquid crystal calculated from the cell gap is dropped and held, a delicate pressure difference is applied in the surface. It is desired that the photo spacer itself has elastic properties.
That is, a photo spacer having a high total deformation amount and a high elastic recovery characteristic is required for pressing and unloading when a panel for holding a liquid crystal between substrates is produced. Photo spacers that do not have such characteristics may cause bubbles in the liquid crystal when the panel is produced, and the cell gap is not uniform, and the liquid crystal display device has problems such as uneven color.

As a material for forming a photospacer having a characteristic that solves this problem, there has been proposed improvement by increasing the amount of monomer (for example, Patent Document 1).

However, when many polyfunctional monomers like the above proposal are used, there is a problem that the adhesion between the spacer and the substrate deteriorates.

In recent years, LCDs have become smaller and more precise, and the pixel size has been reduced to maintain display quality. Therefore, exposure sensitivity and resolution require patterning with a size of 10 μm or less. Has been.
In addition, since the ground contact area between the substrate and the spacer has been reduced, further adhesion is required, and since the spacer diameter has been reduced, further elastic recovery characteristics have been required.
However, it is known that the elastic recovery characteristic is lowered when trying to improve the adhesion.

In recent years, with the widespread use of portable personal computers, mobile phones, personal digital assistants (PDAs), portable game machines, etc., the required performance of display quality has become stricter and the weight of color liquid crystal display devices has been reduced. There is an increasing demand for reduction in manufacturing costs.
Therefore, an attempt has been made to use a resinous substrate instead of a conventionally used glass substrate.

However, when a conventionally known photosensitive resin composition for spacers is used to form spacers on a resin substrate, a high temperature is required during post-baking in the spacer forming step, so that deformation or yellowing of the substrate may occur. There was a problem that happened.
If the temperature during post-baking in the spacer formation process is lowered to avoid deformation and yellowing of the resin substrate and reduce the manufacturing cost, the elastic recovery characteristics of the formed spacer will decrease, and the adhesion to the substrate will decrease. There was a problem that a problem occurred.

As a material for forming a photospacer having the characteristics to solve these problems, a method using a polymerizable compound having an ethylenically unsaturated bond having a specific cyclic structure (Patent Document 2) or a specific onium-based phosphoric acid Proposals have been made to improve elastic recovery characteristics and adhesion to a substrate even when the temperature during post-baking is 200 ° C. or less by using a salt and a polymerizable compound having an ethylenically unsaturated bond in combination (Patent Document 3). Yes.

By the way, it is known that when the spacer diameter is reduced, the elastic recovery characteristic and the adhesion to the substrate are lowered.

Therefore, in the improvements as described in Patent Documents 2 and 3, when the spacer diameter is reduced to obtain a spacer diameter of 10 μm or less, that is, a high-resolution photo spacer, It had the subject that adhesiveness was inadequate.

Thus, with regard to the negative-type photosensitive resin composition that can be developed in the past, after curing by light irradiation, excellent elastic recovery even when post-baking treatment is adopted at a low temperature of 200 ° C. or lower Nothing that can exhibit the characteristics and adhesion to the substrate is known.

JP 2002-174812 A JP 2009-186838 A JP 2009-75284 A

Therefore, the alkali developability is good, the sensitivity is high, the resolution is high, and even when a low temperature treatment of 200 ° C. or lower is adopted after curing by light irradiation, the cured product and the substrate have excellent adhesion, and It is an object of the present invention to provide a photosensitive resin composition for a photospacer having excellent elastic recovery characteristics, and to provide a photospacer having excellent adhesiveness with a substrate and having excellent elastic recovery characteristics.

  The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the above problems. That is, the present invention provides a polyfunctional (meth) acrylate monomer (A) containing at least one functional group selected from the group consisting of a carboxyl group, a sulfo group, a phosphate group, and a phosphate ester group, or a salt thereof. A negative photosensitive resin composition capable of alkali development, containing a siloxane compound (B) having two or more hydrolyzable alkoxy groups, and a radical photopolymerization initiator (C) as essential components. In the (meth) acryloyl group having an acid value based on the total weight of (A) to (C) of the composition of 10 to 110 g / g and based on the total weight of (A) to (C) of the photosensitive resin composition The photosensitive resin composition (Q) for a photospacer, wherein the content of carbon-carbon double bond (C = C) is 6.5 to 10.0 mmol / g; Formed And a photo spacer provided for holding the gap in the liquid crystal cell.

The photosensitive resin composition of the present invention and the photospacer obtained therefrom have the following effects.
-The photosensitive resin composition is excellent in alkali developability.
-The photosensitive resin composition is excellent in resolution.
-The photo spacer has excellent adhesion to the substrate and excellent elastic recovery characteristics.
-Even when a low temperature treatment of 200 ° C. or lower is adopted after curing by light irradiation, the photo spacer obtained in the present invention has excellent adhesion to the substrate and excellent elastic recovery characteristics.

The photosensitive resin composition (Q) for photospacers of the present invention comprises a polyfunctional (meth) acrylate monomer (A) having a specific acidic group or a salt thereof, and a siloxane compound having two or more hydrolyzable alkoxy groups ( B), and a photo-radical polymerization initiator (C) as essential components, and a negative photosensitive resin composition (Q) for photospacer that is excellent in alkali developability and resolution. Furthermore, the photosensitive resin composition (Q) of the present invention has an acid value based on the total weight of (A) to (C) of the photosensitive resin composition of 10 to 110 KOHmg / g, and the photosensitive resin composition. The content (mmol / g) of the carbon-carbon double bond (C = C) in the (meth) acryloyl group based on the total weight of (A) to (C) of 6.5 to 10.0 mmol / g is there. Moreover, specific acidic groups are a carboxyl group, a sulfo group, a phosphate group, and a phosphate ester group.
When the photosensitive resin composition (Q) of the present invention is cured, even when a low temperature treatment of 200 ° C. or lower is adopted after curing by light irradiation, it is a photo excellent in adhesion to the substrate and elastic recovery characteristics. Spacers can be provided.

In the present specification, the expression “(meth) acrylate” with (meth) means “acrylate or methacrylate”.
Further, “content of carbon-carbon double bond (C═C) in (meth) acryloyl group” may be simply referred to as “(meth) acryloyl group concentration”.

In this specification, “(meth) acryloyl group concentration” means the number of carbon-carbon double bonds (C═C) in (meth) acryloyl groups per gram of sample excluding the solvent when the sample contains a solvent. The content (mmol / g) is meant.

  Below, (A)-(C) which is an essential structural component of the photosensitive resin composition of this invention is demonstrated in order.

If the polyfunctional (meth) acrylate monomer (A) which has an acidic group or these salts of this invention is a polyfunctional (meth) acrylate monomer which has a specific acidic group or its salt mentioned later as an essential component below, it will be. It is used without being particularly limited.

  (A) has a structure in which at least one of acidic groups or salt sites thereof is directly bonded to a specific site of polyfunctional (meth) acrylate by a covalent bond, and details thereof will be described below.

As the acidic group in the polyfunctional (meth) acrylate monomer (A), usually, a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phosphoric acid group, a phosphoric ester group, and two or more of these The combined use of an acidic group is mentioned. From the viewpoint of easy availability of raw materials, a carboxyl group is preferred.

The salt moiety in (A) is not particularly limited as long as it is a known salt in which the anion moiety in the above acidic group and a known cation are paired.
Known cations include alkali metal ions (potassium ions, sodium ions, lithium ions, etc.), quaternary ammonium ions (tetraethylammonium, triethylmethylammonium, dimethyldidecylammonium, etc.), amidinium cations (imidazolium cations, tetrahydros). Pyrimidinium cation, dihydropyrimidinium cation, etc.) are preferred.

As the polyfunctional (meth) acrylate part in (A), there are a bifunctional (meth) acrylate part (a1), a trifunctional (meth) acrylate part (a2), and a 4-6 functional (meth) acrylate part (a3). Can be mentioned.

Examples of the bifunctional (meth) acrylate moiety (a1) include esterified products of polyhydric alcohol and (meth) acrylic acid [for example, di (meth) acrylate of glycerin, di (meth) acrylate of trimethylolpropane, 3-hydroxy Di (meth) acrylate of 1,5-pentanediol, di (meth) acrylate of 2-hydroxy-2-ethyl-1,3-propanediol]; alkylene oxide adduct of polyhydric alcohol and (meth) acrylic acid [For example, di (meth) acrylate of trimethylolpropane ethylene oxide adduct, di (meth) acrylate of glycerin ethylene oxide adduct]; OH group-containing both-end epoxy acrylate; polyhydric alcohol and (meth) acrylic Esthetic acid and hydroxycarboxylic acid Iodide [e.g. hydroxypivalic acid neopentyl glycol di (meth) acrylate], and the like.
Of these (a1), from the viewpoint of improving the adhesion between the cured product and the substrate and ease of introduction of acidic groups, OH group-containing both-end epoxy acrylates are preferred.

Examples of the trifunctional (meth) acrylate (a2) include pentaerythritol tri (meth) acrylate, dipentaerythritol triacrylate; pentaerythritol ethylene oxide adduct tri (meth) acrylate, and the like.
Among these (a2), from the viewpoint of photocuring reactivity as the photosensitive resin composition, pentaerythritol triacrylate and dipentaerythritol triacrylate are preferable, and adhesion between the cured product and the substrate is improved. From the viewpoint of ease of introduction, pentaerythritol triacrylate is more preferable.

Examples of the 4-6 functional (meth) acrylate moiety (a3) include dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate; dipentaerythritol For example, tetra (meth) acrylate of an ethylene oxide adduct, penta (meth) acrylate of an ethylene oxide adduct of dipentaerythritol, penta (meth) acrylate of a propylene oxide adduct of dipentaerythritol, and the like.
Among these (a3), from the viewpoint of photocuring reactivity as the photosensitive resin composition, pentaacrylate of dipentaerythritol, hexaacrylate of dipentaerythritol, and pentaacrylate of propylene adduct of dipentaerythritol are preferable. From the viewpoint of improving the adhesion between the cured product and the substrate and ease of introduction of acidic groups, dipentaerythritol pentaacrylate is more preferable.

Of these polyfunctional (meth) acrylate moieties in (A), preferred are (a2) and (a3), and more preferred is (a3) from the viewpoint of photocuring reactivity.

  As (A) which has the polyfunctional (meth) acrylate of this invention comprised by the above-mentioned specific acidic group or salt site | part and polyfunctional (meth) acrylate part (a1)-(a3), it has a carboxyl group. Polyfunctional (meth) acrylate (A1), polyfunctional (meth) acrylate (A2) having a sulfo group, polyfunctional (meth) acrylate (A3) having a phosphate group, polyfunctional (meth) having a phosphate ester group The mixture containing 2 or more types of acrylate (A4), the polyfunctional (meth) acrylate (A5) which has the salt site | part of these acid groups, and (A1)-(A5) is mentioned.

As the polyfunctional (meth) acrylate (A1) having a carboxyl group, for example, succinic acid adduct of pentaerythritol triacrylate, succinic acid adduct of dipentaerythritol pentaacrylate, pentaerythritol triacrylate maleic acid adduct, dipenta Maleic acid adduct of erythritol pentaacrylate, dicarboxylic acid adduct of dipentaerythritol tetraacrylate, maleic acid adduct of EO 6 mol addition pentaerythritol triacrylate, cyclohexenyl carboxylic acid adduct of EO 10 mol addition dipentaerythritol pentaacrylate, etc. Can be mentioned.

Examples of the polyfunctional (meth) acrylate (A2) having a sulfo group include a sulfonate ester of pentaerythritol triacrylate, a sulfonate ester of dipentaerythritol pentaacrylate, and the like.

Examples of the polyfunctional (meth) acrylate (A3) having a phosphoric acid group include phosphoric acid of pentaerythritol triacrylate, phosphoric acid of jantaerythritol pentaacrylate, and the like.

Examples of the polyfunctional (meth) acrylate (A4) having a phosphoric ester group include a phosphoric ester of pentaerythritol triacrylate, a phosphoric ester of zintaerythritol pentaacrylate, and the like.

Examples of the polyfunctional (meth) acrylate (A5) having a salt moiety of the acid group include those obtained by neutralizing the anion moiety in the acidic group with the aforementioned known cation.
For example, pentaerythritol triacrylate succinic acid adduct sodium salt, dipentaerythritol pentaacrylate succinic acid adduct tetraethylammonium salt, pentaerythritol triacrylate maleic acid adduct ethyl methyl imidazolium salt, dipentaerythritol pentaacrylate maleic acid adduct ethyl Examples thereof include methyl imidazolium salt.

  Among these (A1) to (A5), succinic acid adducts of pentaerythritol triacrylate, succinic acid adducts of dipentaerythritol pentaacrylate, and pentaerythritol triacrylate from the viewpoint of elastic recovery characteristics and availability of raw materials Maleic acid adducts of dipentaerythritol pentaacrylate and maleic acid adducts of pentaerythritol triacrylate and maleic acid of dipentaerythritol pentaacrylate are more preferred.

The method for producing (A) having the polyfunctional (meth) acrylate of the present invention is not particularly limited, and a known method or the like can be used.
When a carboxyl group is introduced into a polyfunctional (meth) acrylate, it can be produced using, for example, a condensation reaction, an oxidation reaction, a hydrolysis reaction of a carboxylic acid derivative, a transfer reaction, or the like.
For example, a pentaerythritol triacrylate succinic acid adduct can be produced by reacting a hydroxyl group of pentaerythritol triacrylate with succinic anhydride.

When the sulfo group is introduced into the polyfunctional (meth) acrylate, for example, a sulfonating agent [concentrated sulfuric acid, fuming sulfuric acid, chlorosulfuric acid, sulfuric anhydride complex, etc.] can be used.
For example, dipentaerythritol pentaacrylate can be produced by reacting dipentaerythritol pentaacrylate with chlorosulfuric acid.

Moreover, when introduce | transducing a phosphoric acid group into polyfunctional (meth) acrylate, it can introduce | transduce using phosphoric anhydride etc., for example.
For example, glycerin diacrylate and phosphoric anhydride can be reacted to produce glycerin diacrylate phosphoric acid.

Moreover, when introduce | transducing a phosphate ester group into polyfunctional (meth) acrylate, it can introduce | transduce, for example using monoalkyl phosphate ester etc.
For example, pentaerythritol triacrylate and monodecyl phosphate can be reacted to produce pentaerythritol triacrylate monodecyl phosphate.

A method for purifying the obtained polyfunctional (meth) acrylate having an acidic group is not particularly limited, and a known purification method or the like can be used. For example, when the polyfunctional (meth) acrylate having an acidic group is solid, the obtained polyfunctional (meth) acrylate having an acidic group is filtered, washed with a solvent such as water or an organic solvent, and dried. Can be purified. In addition, when the polyfunctional (meth) acrylate having an acidic group is oily, when the oily product and the solvent are separated into two phases, the solvent is separated into two phases to dissolve in the solvent. In this case, the solvent can be purified by evaporation. Alternatively, water is added to a reaction solution containing a polyfunctional (meth) acrylate having an acidic group, and if necessary, an alkali component is added and dissolved. After separating into an organic solvent phase and an aqueous phase, acid deposition from the aqueous phase. It is also possible to obtain a precipitate by a method such as salting out or the like, and to collect the resulting precipitate by filtration, wash it with an organic solvent and dry it, and then purify it.

The content of the polyfunctional (meth) acrylate (A) based on the total weight of (A) to (C) in the photosensitive resin composition (Q) is usually 30 to 95% by weight, preferably 40 to 95% by weight. More preferably, it is 50 to 95% by weight, particularly preferably 60 to 95% by weight. Within this range, alkali developability, elastic recovery properties, and adhesion to the substrate can be exhibited well, and the water resistance and solvent resistance of the cured product can also be exhibited well.

The siloxane compound (B) having two or more hydrolyzable alkoxy groups, which is the second essential component of the present invention, is composed of, for example, a silane compound (b1) represented by the following general formula (1) as an essential constituent monomer. And a condensate obtained by polymerizing a part or all of the alkoxy group [OR ³ part in the general formula (1)] through a condensation reaction. However, it may be a siloxane compound having a hydrolyzable alkoxy group having another chemical structure.

The “hydrolyzable alkoxy group” as used herein is an alkoxy group having 1 to 8 carbon atoms such as methoxy group, ethoxy group, propyloxy group, isopropyloxy group, butyloxy group, sec-butyloxy group, t -A butyloxy group, a pentyloxy group, a heptyloxy group, and an octyloxy group are mentioned.
On the other hand, phenoxy groups generally do not hydrolyze.

In the general formula (1), R ¹ is selected from the group consisting of a (meth) acryloylalkyl group, a glycidoxyalkyl group, a mercaptoalkyl group, and an aminoalkyl group (the alkyl group has 1 to 6 carbon atoms). One kind of organic group. R ² is an alkyl group having 1 to 12 carbon atoms, an alicyclic saturated hydrocarbon group having 1 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 12 carbon atoms; R ³ is an alkyl group having 1 to 4 carbon atoms. It is an alkyl group. m is 0 or 1.

R ¹ in formula (1) is one organic group selected from the group consisting of a (meth) acryloylalkyl group, a glycidoxyalkyl group, a mercaptoalkyl group, and an aminoalkyl group. Carbon number is 1-6.

Here, when an alkylene group having 1 to 6 carbon atoms is represented by —R ⁴ — or —R ⁶ —, the (meth) acryloylalkyl group is represented by the following general formula (2); the glycidoxyalkyl group is represented by the following general formula ( 3); a mercaptoalkyl group is represented by —R ⁴ —SH; and an aminoalkyl group is represented by —R ⁴ —NH ₂ .

R ⁵ in the formula (2) is a hydrogen atom or a methyl group. -R < ⁴ >-is an alkylene group of 1-6 as above-mentioned.

-R < ⁶ >-in Formula (3) is an alkylene group of 1-6 similarly to -R < ⁴ >-of Formula (2).

In the general formula (1), specific examples of the silane compound having a (meth) acryloylalkyl group in R ¹ include the following compounds in which m is 0 or 1.
Examples of the trifunctional silane compound in which m is 0, that is, three alkoxy groups include 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3- Examples include acryloyloxypropyltriethoxysilane.

  Examples of the trifunctional silane compound in which m is 1, that is, two alkoxy groups include 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-acryloyloxypropylmethyldimethoxysilane, 3 -Acryloyloxypropylmethyldiethoxysilane and the like.

Specific examples of the silane compound having a glycidoxyalkyl group in R ¹ include the following compounds in which m is 0 or 1.
Examples of the trifunctional silane compound in which m is 0, that is, three alkoxy groups include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and the like.

  Examples of the trifunctional silane compound in which m is 1, that is, two alkoxy groups include 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and the like.

Specific examples of the silane compound having a mercaptoalkyl group in R ¹ include the following compounds in which m is 0 or 1.
Examples of the trifunctional silane compound in which m is 0, that is, three alkoxy groups include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and the like.

  Examples of the trifunctional silane compound in which m is 1, that is, two alkoxy groups include 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, and the like.

Specific examples of the silane compound having an aminoalkyl group in R ¹ include the following compounds in which m is 0 or 1.
Examples of trifunctional silane compounds in which m is 0, that is, three alkoxy groups include N-2 aminoethyl γ-aminopropyltrimethoxysilane, N-2 aminoethyl γ-aminopropyltriethoxysilane, and 3-aminopropyltrimethoxy. Silane, 3-aminopropyltriethoxysilane, etc. are mentioned.

  Examples of trifunctional silane compounds in which m is 1, that is, two alkoxy groups include N-2 aminoethyl γ-aminopropylmethyldimethoxysilane, N-2 aminoethyl γ-aminopropylmethyldiethoxysilane, and 3-aminopropylmethyl. Examples include dimethoxysilane and 3-aminopropylmethyldiethoxysilane.

R ¹ does not react in the condensation reaction step of the silane compound (b1) and remains in the siloxane compound (B) after the condensation reaction, and the photosensitive resin composition of the present invention is exposed to light or thermally cured. It is a functional group that contributes to the curing reaction.
Preferred as R ¹ are a (meth) acryloylalkyl group and a glycidoxyalkyl group from the viewpoint of curability.

^{R 2} in the formula (1) represents an alkyl group, an alicyclic saturated hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, having 1 to 12 carbon atoms. The number m is 0 or 1.

Of R ² , examples of the aliphatic saturated hydrocarbon group include a linear alkyl group and a branched alkyl group.
Examples of the linear alkyl group include methyl, ethyl, n-propyl, n-butyl, n-octyl and n-dodecyl groups. Examples of the branched alkyl group include isopropyl, isobutyl, sec-butyl and 2-ethylhexyl groups. Can be mentioned.

Examples of the alicyclic saturated hydrocarbon group include a cyclohexyl group, a cyclooctyl group, a cyclohexylmethyl group, a cyclohexylethyl group, and a methylcyclohexyl group.

Among R ² , examples of the aromatic hydrocarbon group include an aryl group, an aralkyl group, and an alkylaryl group.
As aryl groups, phenyl, biphenyl, naphthyl groups and their deuterium, fluorine or chlorine substituents; As aralkyl groups, tolyl, xylyl, mesityl and their deuterium, fluorine or chloride; and as alkylaryl groups Examples include methylphenyl and ethylphenyl groups.

Among R ^2, a linear alkyl group, a branched alkyl group and an aryl group are preferable from the viewpoint of curing reactivity, and a linear alkyl group and an aryl group are more preferable. Particularly preferred are a methyl group, an ethyl group, a phenyl group and a combination thereof.

Examples of R ³ in the formula (1) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a sec-butyl group. Preferred is methyl from the viewpoint of thermosetting reactivity. Group and ethyl group.
The number of OR ³ groups bonded to the Si atom is (3-m), specifically, 3 or 2.

Among the silane compounds (b1) represented by the general formula (1), R ¹ in the general formula (1) preferably has a (meth) acryloylalkyl group or a glycidoxyalkyl group from the viewpoint of curing reactivity. Silane compound.
More preferred are (meth) acryloyloxyalkyl group-containing trifunctional silane compounds having 3 alkoxy groups, and glycidoxyalkyl group-containing trifunctional silane compounds having 3 alkoxy groups, and particularly preferred are 3-acryloyloxypropyltrimethoxysilane and 3-glycidoxypropyltrimethoxysilane.

  As the siloxane compound (B) having two or more hydrolyzable alkoxy groups, a homocondensation polymer consisting only of the silane compound (b1) represented by the general formula (1), and (b1) and (b1) Examples thereof include cocondensates of one or more other silane compounds capable of cocondensation.

Examples of such other silane compounds include silane compounds represented by the following general formula (4).

R ⁷ _n Si (OR ⁸ ) _4-n (4)

In formula (4), R ⁷ is an alkyl group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, R ⁸ is an alkyl group having 1 to 4 carbon atoms, and n is 0 to 0. It is an integer of 2.

Of R ^7, a linear alkyl group, a branched alkyl group, and an aryl group are preferable, a linear alkyl group and an aryl group are more preferable, and a methyl group, an ethyl group, a phenyl group, and a combination thereof are particularly preferable.
R ⁸ is preferably a methyl group or an ethyl group.

In the general formula (4), n is 0, that is, examples of the tetrafunctional silane compound having four alkoxy groups include tetramethoxysilane and tetraethoxysilane.
Examples of the trifunctional silane compound in which n is 1, that is, three alkoxy groups include phenyltrimethoxysilane, phenyltriethoxysilane, methyltrimethoxysilane, and methyltriethoxysilane.
Examples of the bifunctional silane compound in which n is 2, that is, two alkoxy groups include diphenyldimethoxysilane, diphenyldiethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyldimethoxysilane, and phenylmethyldiethoxysilane. .
From the viewpoint of forming a uniform network of polysiloxane (B), n is preferably 1, that is, a trifunctional silane compound.

  From the viewpoint of curing reactivity, the charging ratio of the other silane compound is preferably 0.1 to 6.0 mol, more preferably 0.2 to 4 with respect to 1 mol of (b1). 0.0 mole is good.

  The siloxane compound (B) is, for example, about 10 to 20 ° C. at 20 to 100 ° C. in a dry atmosphere while stirring a predetermined amount of water and, if necessary, the catalyst in the silane compound (b1) and other silane compounds used as necessary. It can be obtained by performing a condensation reaction by dropping over a period of 60 minutes to 60 minutes and then aging for 1 to 12 hours at a temperature below the boiling point of the by-produced alcohol (for example, 0 to 150 ° C.).

If the amount of water added in the condensation reaction is X mol and the number of moles of alkoxy groups in the silane compound (b1) and other silane compounds is Y, the yield and molecular weight of the condensate will decrease if X / Y is too small. To do.
On the other hand, when X / Y is too large, the molecular weight becomes too large and the storage stability tends to decrease.
From this, it is preferable to carry out in the range of 0.1 <X / Y <5, preferably in the range of 0.3 <X / Y <3.
As the water to be added, ion exchange water or distilled water is usually used. Moreover, the silane compound which has one alkoxy group can also be added for the purpose of molecular weight adjustment. Examples of the silane compound having one alkoxy group include phenyltrimethoxysilane and methyltrimethoxysilane.

  Condensation reaction catalysts include formic acid, acetic acid, succinic acid, lactic acid, malonic acid, citric acid, tartaric acid, malic acid, succinic acid, fumaric acid, phthalic acid, pyromellitic acid, p-toluenesulfonic acid, methanesulfonic acid, trifluoro Monovalent, divalent or trivalent organic acids such as acetic acid and trifluoromethanesulfonic acid; inorganic acids such as hydrochloric acid, phosphoric acid, nitric acid, hydrofluoric acid, bromic acid, chloric acid and perchloric acid; alkali metal hydroxides; Alkaline earth hydroxides, quaternary alkylammonium hydroxides and carbonates and alkali salts such as primary to tertiary amines; quaternary alkylammonium halides; sodium hypochlorite; tin, zirconium, titanium Alkoxides of metals other than silicon, such as aluminum and boron, and their chelate complexes; Organic acid among inorganic acids, metal alkoxide, an acid catalyst is preferable, chelate compounds of a metal alkoxide, an organic acid is particularly preferred.

The addition amount of the catalyst is 0.0001 to 10 parts by weight, preferably 0.001 to 1 part by weight with respect to 100 parts by weight of the total of the silane compound (b1) and other silane compounds. The method for adding the catalyst is not particularly limited, but it is preferably added as an aqueous solution. Moreover, preferable reaction temperature is 20 to 100 degreeC.

The absolute value of the difference in SP value between the siloxane compound (B) and the polyfunctional (meth) acrylate monomer (A) having an acidic group described above is preferably 0 to 0 from the viewpoint of compatibility and elastic recovery properties of the cured product. It is 2.0, more preferably 0 to 1.9, particularly preferably 0 to 1.5, and particularly preferably 0 to 1.0.

The SP value of the siloxane compound (B) is preferably 7.0 to 13.0, more preferably 8.0 to 12.0, particularly preferably 8.0 to 11.0, and particularly preferably 8.0. ~ 10.5.

The SP value in the present invention is calculated by the method described in the following document proposed by Fedors et al.
"POLYMER ENGINEERING AND SCIENCE, February, 1974, Vol. 14, No. 2, Robert F. Fedors. (Pp. 147-154)"

  The content of (B) based on the total weight of (A) to (C) of the photosensitive resin composition (Q) is usually preferably 1 to 40% by weight, more preferably 1 to 30% by weight, particularly preferably. 5 to 30% by weight. Within this range, the elastic recovery property and the adhesion to the substrate can be exhibited more satisfactorily, and the compatibility can also be exhibited better.

  The number average molecular weight (hereinafter referred to as Mn) of the siloxane compound (B) is preferably 500 to 100,000, more preferably 1 from the viewpoint of elastic recovery characteristics when it becomes a photo spacer and adhesion to the substrate. 1,000 to 50,000, particularly preferably 2,000 to 20,000.

Mn is a value in terms of polystyrene measured by the GPC method using a GPC measuring device (HLC-8120GPC, manufactured by Tosoh Corporation) and a column (2 TSKgel GMHXL + TSKgel Multipore HXL-M, manufactured by Tosoh Corporation). As sought.

The photo radical polymerization initiator (C) is composed of a component that generates a radical capable of initiating polymerization of the polymerizable unsaturated compound by exposure to radiation such as visible light, ultraviolet light, far infrared light, charged particle beam, and X-ray. Examples of such radical photopolymerization initiators include acetophenone derivative (C1), acylphosphine oxide derivative (C2), titanocene derivative (C3), triazine derivative (C4), bisimidazole derivative (C5), O-acyloxy (Oxime ester) derivative (C6), benzophenone derivative (C7), thioxanthone derivative (C8), α-diketone derivative (C9), anthraquinone derivative (C10), acridine derivative (C11), these (C1) to (C11) And a mixture containing two or more of them.

Examples of the acetophenone derivative (C1) include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, benzyldimethyl ketal, 2-hydroxy-2-methylpropiophenone, 4-isopropyl-2-hydroxy-2-methylpropiophenone, 2 -Methyl-1- (4- (methylthio) phenyl) -2-morpholino-1-propanone, dimethylbenzyl ketal, methylbenzoylformate, 2-benzyl-2-dimethylamino-1- (4-morpholino Eniru) - butan-1-one] and the like.

Examples of the acylphosphine oxide derivative (C2) include trimethylbenzoyldiphenylphosphine oxide.

Examples of the titanocene derivative (C3) include bis (η ⁵ -2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium. It is done.

Examples of the triazine derivative (C4) include trichloromethyltriazine and benzyl-2,4,6- (trihalomethyl) triazine.

Examples of the bisimidazole derivative (C5) include 2- (o-chlorophenyl) -4,5-diphenylimidazolyl dimer.

Examples of the O-acyloxime (oxime ester) derivative (C6) include 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], ethanone, 1- [9. -Ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime).

Examples of the benzophenone derivative (C7) include benzophenone, 4,4-bis (dimethylamino) benzophenone, 3,3-dimethyl-4-methoxy-benzophenone, and Michler's ketone.

Examples of the thioxanthone derivative (C8) include isopropylthioxanthone, 2-chlorothioxanthone, diethylthioxanthone, isopropylthioxanthone, and diisopropylthioxanthone.

Examples of the α-diketone derivative (C9) include camphorquinone.

Examples of the anthraquinone derivative (C10) include anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, and tert-butylanthraquinone.

Examples of the acridine derivative (C11) include 9-phenylacridine, 1,7-bis (9-acridinyl) heptane, 1,5-bis (9-acridinyl) pentane, and 1,3-bis (9-acridinyl) propane. Can be mentioned.

  Of these (C1) to (C11), from the viewpoint of ease of synthesis, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholino-1-propanone and 2-benzyl-2-dimethylamino -1- (4-morpholinophenyl) -butan-1-one is preferred, and 2-methyl-1- (4- (methylthio) phenyl) -2-morpholino-1-propanone is more preferred from the viewpoint of reactivity.

(C) can be easily obtained commercially, for example, 2-methyl-1- (4- (
As methylthio) phenyl) -2-morpholino-1-propanone, Irgacure 9
Examples of 07, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one include Irgacure 369 (Ciba Specialty Chemicals).

The content of (C) based on the total weight of (A) to (C) of the photosensitive resin composition (Q) is preferably 1 to 15% by weight, more preferably 3 to 12% by weight, particularly preferably 5 -10% by weight. If it is 1% by weight or more, curing reactivity and elastic recovery characteristics can be exhibited more satisfactorily, and if it is 15% by weight or less, mask stain reduction and compatibility during photoexposure can be further exhibited.

The acid value of the photosensitive resin composition (Q) is usually from 10 to 110 KOHmg / g, preferably from 25 to 90 KOHmg / g, based on the total weight of the photosensitive resin composition (A) to (C). Preferably it is 40-80KOHmg / g, Most preferably, it is 50-75KOHmg / g. Within this range, the developability is more easily exhibited, and the water resistance of the cured product can be further improved.

The acid value in the present invention can be measured by an indicator titration method using an alkaline titration solution. The method is as follows.
(I) About 1 g of a sample is precisely weighed and placed in an Erlenmeyer flask, and then a neutral methanol / acetone solution (a mixture of acetone and methanol at 1: 1 (volume ratio)) is added and dissolved.
(Ii) Add several drops of phenolphthalein indicator and titrate with 0.1 mol / L potassium hydroxide titration solution. The end point of neutralization is defined as the time when the indicator is slightly red for 30 seconds.
(Iii) Determine using the following equation.
Acid value (KOHmg / g) = (A × f × 5.61) / S
Where A is the number of mL of the 0.1 mol / L potassium hydroxide titration solution, f is the titer of the 0.1 mol / L potassium hydroxide titration solution, S is the sampled amount (g) [where the sample is the solvent Is included, the amount excluding the solvent (g)].

  The content (mmol / g) of the carbon-carbon double bond (C = C) in the (meth) acryloyl group based on the total weight of (A) to (C) of the photosensitive resin composition is usually 6.5. It is-10.0 mmol / g, Preferably it is 7.0-10.0 mmol / g, More preferably, it is 7.5-9.5 mmol / g, Most preferably, it is 8.0-9.5 mmol / g. Within this range, the elastic recovery characteristics can be satisfactorily exhibited.

Here, the content (mmol / g) of the carbon-carbon double bond in the (meth) acryloyl group in the present invention refers to the acryloyl group or methacryloyl group in the photosensitive resin composition (Q) of the present invention. This refers to the content (mmol / g) of the resulting carbon-carbon double bond (C = C).

The concentration of the double bond can be measured by a titration method using an addition reaction (Michael addition) of an amine to a double bond of a (meth) acryloyl group.
The specific measurement method is as follows.

(1) About 1 g of a sample is precisely weighed and placed in an Erlenmeyer flask, and then about 10 ml of acetone is added and dissolved.
(2) Add 10 ml of morpholine standard solution [mixed formolin and methanol 1: 4 (volume ratio)], and then add 50% acetic acid standard solution [acetic acid and ion-exchanged water 1: 1 (volume ratio) After adding 1.5 ml and shaking well, leave it at room temperature for 15 minutes.
(3) Add 15 ml of acetonitrile and 10 ml of acetic anhydride to the Erlenmeyer flask and shake well.
(4) Titrate with a 0.5 mol / L acetic acid / methanol titration solution using a recording type automatic titrator.
(5) A blank test is performed at the same time, and the following formula is used.

Double bond concentration (mmol / g) = f × (A−B) / 2S
However, A is the number of ml of 0.5 mol / L acetic acid / methanol titration solution required for the titration of the sample, B is the number of ml of 0.5 mol / L acetic acid / methanol titration solution required for the blank test, f Represents the titer of a 0.5 mol / L acetic acid / methanol titration solution, and S represents the sample collection amount (g) [when the sample contains a solvent, the amount excluding the solvent (g)].

Furthermore, the higher the hydroxyl group concentration in the photosensitive resin composition (Q), the better the adhesion between the cured product of the photosensitive resin composition (Q) and the substrate.
From the viewpoint of improving adhesion, the hydroxyl group concentration based on the total weight of (A) to (C) of the photosensitive resin composition is preferably 1.5 to 5.0 mmol / g, and 2.0 to 5.0 mmol / g. Is more preferable, and 2.5 to 5.0 mmol / g is particularly preferable. Within this range, the adhesion and water resistance between the cured product of the photosensitive resin composition (Q) and the substrate can be further improved.

The hydroxyl group concentration (mmol / g) refers to the hydroxyl group content (mmol / g) in the photosensitive resin composition (Q) of the present invention.
Examples of the hydroxyl group include alcoholic hydroxyl groups, phenolic hydroxyl groups, hydroxyl groups in carboxyl groups, hydroxyl groups in sulfonic acid groups, hydroxyl groups in phosphoric acid groups, and the like. Of these hydroxyl groups, an alcoholic hydroxyl group and a hydroxyl group within a carboxyl group are preferred, and an alcoholic hydroxyl group is more preferred.

This hydroxyl group concentration can be measured by calculating from the hydroxyl value obtained by the phthalic anhydride method (based on JIS K1557) utilizing a dehydration condensation reaction between a hydroxyl group and phthalic anhydride.
The specific measurement method is as follows.

(I) About 1 g of a sample is precisely weighed and placed in an Erlenmeyer flask, and dissolved in 5 ml of an acetylating agent [mixture of phthalic anhydride and pyridine at 1: 4 (volume ratio)].
(Ii) Heat at 100 ° C. for 2 hours, add 1 ml of water, vibrate well, and leave at room temperature for 10 minutes.
(Iii) Titration is performed using phenolphthalein as an indicator and KOH aqueous solution (0.5 mol / L) as a titrant.
(Iv) The acid value is measured for the same sample.
(V) A blank test is performed at the same time, and the hydroxyl value is calculated by the following formula.
Hydroxyl value (KOHmg / g) = (BA) × f × 28.05 / S + C
However, A is the number of ml of the 0.5 mol / L potassium hydroxide titration solution required for the titration of the sample, B is the number of ml of the 0.5 mol / L potassium hydroxide titration solution required for the blank test, f Is the force value of the 0.5 mol / L potassium hydroxide titration solution, S is the amount of sample collected (g [amount excluding the solvent (g) if the sample contains a solvent)], C is the acid value [the measurement method is As described above].
(Vi) Using the hydroxyl value obtained by the above equation, the hydroxyl group concentration is calculated by the following equation.
Hydroxyl concentration (mmol / g) = hydroxyl value / 56.1

  In addition to the essential components (A) to (C) of the photosensitive resin composition (Q) of the present invention, the elastic recovery characteristics are impaired for the purpose of further improving the developability and the adhesion between the cured product and the substrate. The hydrophilic epoxy resin (D) can be added within a range that does not exist.

  The hydrophilic epoxy resin (D) is a hydrophilic epoxy resin having one or more (meth) acryloyl groups and one or more carboxyl groups as essential components in the molecule.

The hydrophilicity index in the hydrophilic epoxy resin (D) of the present invention is defined by HLB. Generally, the larger this value, the higher the hydrophilicity.
The preferred range of the HLB value of the hydrophilic epoxy resin (D) varies depending on the resin skeleton of the hydrophilic epoxy resin (D) (for example, vinyl resin, epoxy resin, polyester resin, etc.), preferably 4 to 19, More preferably, it is 5-18, Most preferably, it is 6-17. When it is 4 or more, the developing property is further improved when developing the photo spacer, and when it is 19 or less, the water resistance of the cured product is further improved.

Here, “HLB” is an index indicating the balance between hydrophilicity and lipophilicity, and is calculated by the Oda method described in “Introduction to Surfactants” (2007, Takehiko Fujimoto), item 212. And is not a calculated value by the Griffin method.
The HLB value can be calculated from the ratio between the organic value and the inorganic value of the organic compound.
HLB≈10 × Inorganic / Organic values for deriving organic HLB and inorganic values are described in “Introduction to Surfactant” (2007, Takehiko Fujimoto), page 213. It can be calculated.

  Moreover, the solubility parameter (henceforth SP value) of hydrophilic epoxy resin (D) becomes like this. Preferably it is 7-14, More preferably, it is 8-13, Most preferably, it is 11-13. When it is 7 or more, the developability can be further improved, and when it is 14 or less, the water resistance of the cured product is further improved.

The hydrophilicity of the hydrophilic epoxy resin (D) is exhibited by having a hydrophilic group at the side chain and / or terminal of the polymer.

  The hydrophilic group possessed by the hydrophilic epoxy resin (A) of the present invention includes, in addition to the essential carboxyl group, a hydroxyl group, amino group, amide group, urethane group, urea group, epoxy group, polyether group, sulfonic acid group, sulfuric acid group. Examples thereof include an ester group, a phosphoric acid group, and a phosphoric acid ester group. Furthermore, you may contain more carboxyl groups. Of these hydrophilic groups, from the viewpoint of alkali developability, an epoxy group, a sulfonic acid group, and an additional carboxyl group are preferable, and a carboxyl group is more preferable.

The carboxyl group content of the hydrophilic epoxy resin is indicated by an acid value. The acid value of the hydrophilic epoxy resin (D) is preferably 10 to 500 mgKOH / g, more preferably 15 to 300 mgKOH / g, and particularly preferably 20 to 150 mgKOH / g. Within this range, the developability is more easily exhibited, and the water resistance of the cured product can be further improved.

  The HLB value of (D) is preferably 4 to 14, more preferably 5 to 13, and particularly preferably 6 to 12. If the HLB of (D) is 4 or more, the developability can be satisfactorily exhibited.

A preferred method for producing a hydrophilic epoxy resin (D) having at least one (meth) acryloyl group and a carboxyl group in the molecule includes (meth) acryloyl group in the epoxy group in the raw material epoxy resin (D ₀ ). The monocarboxylic acid (d) is reacted to open the epoxy group to form a hydroxyl group, and a polyvalent carboxylic acid or polyvalent carboxylic acid is added to a part of the hydroxyl group of the (meth) acrylic acid adduct of (D ₀ ). In this method, the anhydride (e) is reacted.

Examples of the epoxy resin (D ₀ ) include aliphatic epoxy resins [eg, Epototo YH-300, PG-202, PG-207 (all manufactured by Toto Kasei Co., Ltd.)] and alicyclic epoxy resins [eg, CY-179, CY. -177, CY-175 (both manufactured by Asahi Kasei Epoxy Co., Ltd.)] and aromatic epoxy resins [for example, phenol novolac epoxy resin, cresol novolac epoxy resin, bisphenol A epoxy resin, biphenyl type epoxy resin, glycidyl-modified polyvinylphenol, etc.] Is mentioned.
Among these, aromatic epoxy resins are preferable from the viewpoint of curability.

Examples of the (meth) acryloyl group-containing monocarboxylic acid (d) used for the production of (D) include acrylic acid, methacrylic acid, and 2-acryloyloxyethyl succinic acid.

The polyvalent carboxylic acid and polyvalent carboxylic acid anhydride (e) used in the production of (D) include unsaturated polyvalent carboxylic acids and their anhydrides, and saturated polyvalent (2-6 valent) carboxylic acids. (For example, aliphatic saturated polycarboxylic acids such as oxalic acid, succinic acid, phthalic acid, adipic acid, dodecanedioic acid, dodecenyl succinic acid, pentadecenyl succinic acid, octadecenyl succinic acid; tetrahydrophthalic acid, hexahydro Phthalic acid, methyltetrahydrophthalic acid, trimellitic acid, pyromellitic acid, biphenyltetracarboxylic acid, aromatic polycarboxylic acid such as naphthalenetetracarboxylic acid), and their anhydrides (for example, succinic anhydride, dodecenyl succinic anhydride) Aliphatic saturated polycarboxylic acid anhydrides such as pentadecenyl succinic anhydride and octadecenyl succinic anhydride; phthalic anhydride , Aromatic polycarboxylic anhydrides such as tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, biphenyltetracarboxylic anhydride, naphthalenetetracarboxylic anhydride ) And the like.
Of these, saturated polyvalent carboxylic acid anhydrides are preferable from the viewpoints of reactivity and developability.

In the preparation of (D), the charged weight ratio of (meth) acryloyl group-containing monocarboxylic acid (d) / (D ₀ ) is preferably such that the concentration of (D) (meth) acryloyl group is 1.0 mmol. It is a preparation weight ratio which becomes more than / g.
From the above viewpoint, the weight ratio of (meth) acryloyl group-containing monocarboxylic acid / (D ₀ ) is preferably 0.072 or more / 1, and more preferably 0.079 to 0.72 / 1. Further, the weight ratio of the (meth) acryloyl group-containing monocarboxylic acid is preferably 0.092 or more / 1, more preferably 0.10 to 0.92 / 1, from the above viewpoint.

The reaction temperature in the reaction of the aforementioned (D ₀ ) and the (meth) acryloyl group-containing monocarboxylic acid (d) is not particularly limited, but is preferably 70 to 110 ° C. The reaction time is not particularly limited, but is preferably 5 to 30 hours. If necessary, a catalyst (for example, triphenylphosphine) and a radical polymerization inhibitor (hydroquinone, p-methoxyphenol, etc.) may be used.

Further, the charged equivalent of the polyvalent carboxylic acid or polyvalent carboxylic acid anhydride (e) relative to the weight of the (meth) acrylic acid adduct of (D ₀ ) is preferably the acid value of (D1), preferably 10 The charge equivalent of (e) such that it is ˜500 mg KOH / g. For example, when (e) is a divalent carboxylic acid or an anhydride thereof, the charge equivalent of (e) / (meth) of (D ₀ ) From the above viewpoint, the weight of the acrylic acid adduct is preferably 0.18 to 8.9 meq / g, more preferably 0.53 to 7.1 meq / g.

The reaction temperature in the reaction of the raw material (D ₀ ) (meth) acrylic acid adduct and (e) is not particularly limited, but is preferably 70 to 110 ° C. The reaction time is not particularly limited, but is preferably 3 to 10 hours.

  Mn in the above (D) is usually 500 to 3,000, preferably 1,000 to 2,800, particularly preferably 1,500, from the viewpoint of photocuring reactivity and developability as the photosensitive resin composition. ~ 2,500.

The content of (D) based on (A) to (D) of the photosensitive resin composition (Q) is usually 5 to 35% by weight, preferably 5 to 30% by weight, more preferably 10 to 25% by weight, Particularly preferred is 10 to 20% by weight. Within this range, alkali developability and adhesion to the substrate can be satisfactorily exhibited.

When the photosensitive resin composition (Q) contains the above-mentioned (D), the acid value based on the total weight of (A) to (D) in the photosensitive resin composition is usually 10 to 110 KOHmg / g, and photosensitive. The content (mmol / g) of the carbon-carbon double bond (C = C) in the (meth) acryloyl group based on the total weight of (A) to (D) of the conductive resin composition is usually 6.5 to 10 0.0 mmol / g.
From the viewpoint of developability and water resistance, the acid value based on the total weight of the photosensitive resin compositions (A) to (D) is preferably 25 to 90 KOHmg / g, more preferably 40 to 80 KOHmg / g, and particularly preferably 50. -75 KOH mg / g. Within this range, developability and water resistance of the cured product are further improved.
Further, from the viewpoint of elastic recovery properties, the content of the carbon-carbon double bond (C = C) in the (meth) acryloyl group based on the total weight of the photosensitive resin compositions (A) to (D) (mmol / g) is preferably 6.5 to 10.0 mmol / g, more preferably 7.5 to 9.5 mmol / g, and particularly preferably 8.0 to 9.5 mmol / g. If it is 6.5 mmol / g or more, the elastic recovery property can be further improved. Moreover, in the case of 6.0 mmol / g or less, although adhesiveness improves further, there exists a problem that an elastic recovery rate falls.

Furthermore, the photosensitive resin composition (Q) may contain other polyfunctional (meth) acrylates (E) other than (A) as long as developability and elastic recovery properties are not impaired.
Such a polyfunctional (meth) acrylate (E) is not particularly limited as long as it is a known polyfunctional (meth) acrylate monomer, and is used without limitation, bifunctional (meth) acrylate (E1), trifunctional (meta) ) Acrylate (E2), 4-6 functional (meth) acrylate (E3), and a mixture containing two or more thereof.

As the bifunctional (meth) acrylate (E1), an esterified product of a dihydric alcohol and (meth) acrylic acid [for example, di (meth) acrylate of ethylene glycol, di (meth) acrylate of diethylene glycol, di (meth) of propylene glycol Acrylate, di (meth) acrylate of dipropylene glycol]; esterified product of polyalkylene oxide of dihydric alcohol and (meth) acrylic acid [for example, di (meth) acrylate of polyethylene glycol, di (meth) acrylate of polypropylene glycol]; Trivalent or higher polyhydric alcohol and esterified product of (meth) acrylic acid [for example, di (meth) acrylate of neopentyl glycol, di (meth) acrylate of glycerin]; linear aliphatic diol and (meth) acrylic acid No Tellurides [for example, di (meth) acrylate of 1,4-butanediol, di (meth) acrylate of 1,6-hexanediol, di (meth) acrylate of 1,9-nonanediol, 1,10-decanediol Di (meth) acrylate]; esterified product of aliphatic diol having a side chain and (meth) acrylic acid [for example, di (meth) acrylate of 3-methyl-1,5-pentanediol, 2-butyl-2-ethyl- 1,3-propanediol di (meth) acrylate]; esterified product of alicyclic hydrocarbon diol and (meth) acrylic acid [for example, dimethylol-tricyclodecane di (meth) acrylate]; aromatic hydrocarbon Esterified product of diol and (meth) acrylic acid [for example, di (meth) acrylate of bisphenol A]; polyvalent alcohol And (meth) acrylic acid esterified products [for example, di (meth) acrylate of ethylene oxide adduct of bisphenol A, di (meth) acrylate of propylene oxide adduct of bisphenol A, di (meth) acrylate of ethylene oxide adduct of pentaerythritol ) Acrylate]; esterified product of polyhydric alcohol, (meth) acrylic acid and hydroxycarboxylic acid [for example, hydroxypivalic acid neopentyl glycol di (meth) acrylate]; OH group-containing both-end epoxy acrylate and the like.
Among these (E1), polypropylene glycol diacrylate and OH group-containing both-end epoxy acrylate are preferable from the viewpoint of improving the adhesion between the cured product and the substrate.

Trifunctional (meth) acrylate (E2) includes glycerol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, and tri (meth) acrylate of trimethylolpropane ethylene oxide adduct Etc.
Among these (E2), pentaerythritol triacrylate and trimethylolpropane triacrylate are preferred from the viewpoint of photocuring reactivity as the photosensitive resin composition, and from the viewpoint of adhesion to the substrate and photocuring reactivity, More preferred is pentaerythritol triacrylate.

Examples of the 4- to 6-functional (meth) acrylate (E3) include pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and poly (meta) of these alkylene oxide adducts. ) Acrylate and the like.
Among these (E3), from the viewpoint of photocuring reactivity as the photosensitive resin composition, dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate of a propylene adduct are preferable. From the viewpoints of adhesion and photocuring reactivity, dipentaerythritol pentaacrylate is more preferable.

Among the other polyfunctional (meth) acrylate monomers (E), preferred are (E2) and (E3), and more preferred are hydrophilic groups described later from the viewpoint of compatibility with (A) to (D). And those containing no hydrophilic group. Particularly preferred are dipentaerythritol pentaacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, and combinations thereof.

As (E) which can be easily obtained from the market, for example, Aronix M-403 (manufactured by Toagosei Co., Ltd .: pentaerythritol triacrylate), light acrylate PE-3A (manufactured by Kyoeisha Chemical Co., Ltd .: pentaerythritol triacrylate) , Neomer DA-600 (manufactured by Sanyo Chemical Industries, Ltd .: a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate) and the like.

Of the polyfunctional (meth) acrylate monomer (E), examples of the hydrophilic group possessed by the polyfunctional (meth) acrylate monomer (E) containing a hydrophilic group include a hydroxyl group, an amino group, and a polyether group. Of these hydrophilic groups, a hydroxyl group and a polyether group are preferable, and a hydroxyl group is more preferable.

In addition, (E) in the present invention may be used in combination with the photosensitive acrylic oligomer (E4) in addition to the above (E1) to (E3).
Examples of the photosensitive acrylic oligomer (E4) include urethane acrylate and polyester acrylate having Mn of 1,000 or less and having two or more acryloyl groups in one molecule.

The content of (E4) in (E) is preferably 50% by weight or less, more preferably 30% by weight or less.

The content of (E) based on (A) to (E) of the photosensitive resin composition (Q) is usually 50% by weight or less, preferably 5 to 40% by weight, more preferably 5 to 30% by weight, particularly Preferably, it is 5 to 20% by weight. Within this range, alkali developability, elastic recovery characteristics of the cured product, and adhesion to the substrate can be satisfactorily exhibited.

When the photosensitive resin composition (Q) contains the above-mentioned (E), the acid value based on the total weight of (A) to (E) in the photosensitive resin composition is usually 10 to 110 KOHmg / g, and photosensitive The content (mmol / g) of the carbon-carbon double bond (C = C) in the (meth) acryloyl group based on the total weight of (A) to (E) of the conductive resin composition is usually 6.5 to 10 0.0 mmol / g.
From the viewpoint of developability and water resistance, the acid value based on the total weight of the photosensitive resin compositions (A) to (E) is preferably 25 to 90 KOHmg / g, more preferably 40 to 80 KOHmg / g, and particularly preferably 50. -75 KOH mg / g. Within this range, developability and water resistance of the cured product are further improved.
Further, from the viewpoint of elastic recovery properties, the content of the carbon-carbon double bond (C = C) in the (meth) acryloyl group based on the total weight of the photosensitive resin compositions (A) to (E) (mmol / g) is preferably 6.5 to 10.0 mmol / g, more preferably 7.5 to 9.5 mmol / g, and particularly preferably 8.0 to 9.5 mmol / g. If it is 6.5 mmol / g or more, the elastic recovery property can be further improved. Moreover, in the case of 6.0 mmol / g or less, although adhesiveness improves further, there exists a problem that an elastic recovery rate falls.

The photosensitive resin composition (Q) may further contain other components as necessary.
Other components include inorganic fine particles, sensitizers, polymerization inhibitors, solvents, thickeners, surface conditioners, and other additives (eg, inorganic pigments, silane coupling agents, dyes, fluorescent brighteners, Yellowing inhibitors, antioxidants, antifoaming agents, deodorants, fragrances, bactericides, antibacterial agents, fungicides, etc.).

The photosensitive resin composition (Q) of the present invention can be obtained, for example, by mixing the above-described components with a known mixing device such as a planetary mixer. The photosensitive resin composition is usually liquid at room temperature, and its viscosity is 0.1 to 10,000 mPa · s, preferably 1 to 8,000 mPa · s at 25 ° C.

  The photosensitive resin composition (Q) of the present invention has good alkali developability, is excellent in the elastic recovery characteristics of the cured product and the adhesion to the substrate, and is subjected to a post-bake treatment at a temperature of 200 ° C. or lower, which is lower than usual. Even when it is adopted, the cured product is excellent in the elastic recovery characteristics and the adhesion to the substrate, and is particularly suitable as a photosensitive resin composition for a photospacer provided for maintaining a gap in a liquid crystal cell.

In general, the elastic recovery characteristic of a photospacer can be evaluated by the “elastic recovery rate” when a certain pressure is applied, and the higher the elastic recovery rate, the better the elastic recovery characteristic.
And the elastic recovery rate becomes small, so that pressurization is large.

By the way, when a conventionally known photosensitive resin composition is cured by light irradiation and a post-bake treatment is employed at a temperature higher than 200 ° C., for example, 230 ° C., 0.3 mN / μm ^{2 of the} formed photo spacer. The elastic recovery rate under the pressure condition is usually about 70%.
However, when the pressure condition is increased to 0.5 mN / μm ² , the elastic recovery rate is greatly reduced.
Furthermore, when post-baking is employed at 200 ° C. or lower, for example, 150 ° C., only a recovery elastic modulus of about 30% can be obtained under a pressure condition of 0.5 mN / μm ² .

However, the photosensitive resin composition (Q) of the present invention is 0.5 mN / μm of the formed photo spacer even when the photosensitive resin composition is cured by light irradiation and a low temperature treatment of 200 ° C. or less is adopted. The elastic recovery rate under the pressure condition of ² is usually 50% to 100%, preferably 60 to 100%, more preferably 70 to 100%, and particularly preferably 80 to 100%.
When the elastic recovery rate is 70% or more, the elastic recovery characteristic can be further improved, and there is a high possibility that it can be used practically without any problem as a spacer for holding the liquid crystal cell gap. When it is 45% or less, the adhesion is further improved, but the elastic recovery characteristic is low, and there is a high possibility that it will be a practical problem that the liquid crystal cell gap cannot be maintained.

The photo spacer of the present invention will be described below.
The photospacer of the present invention is a photospacer that is formed by curing the photosensitive resin composition (Q) and is provided for maintaining a gap in the liquid crystal cell.
The photo spacer determines the gap of the liquid crystal cell when the color filter substrate and the TFT substrate are bonded together, and plays an important role for display quality. The height of the photo spacer usually has a constant height in the range of about 2 to 5 μm, and its uniformity is required. In addition to the height, the shape, size, density, and the like required for the photo spacer are appropriately determined depending on the design of the liquid crystal display device.

The preferable formation process of the photospacer of the present invention is a process in which a photosensitive resin composition is applied onto a substrate, irradiated with light, subjected to alkali development to form a pattern, and further post-baked.
The formation of the photo spacer is usually performed in the following steps (1) to (5).

(1) The process of apply | coating the photosensitive resin composition of this invention on the transparent common electrode provided on the colored layer of a board | substrate. Examples of the coating method include roll coating, spin coating, spray coating, and slit coating. Examples of the coating apparatus include spin coater, air knife coater, roll coater, bar coater, curtain coater, gravure coater, and comma coater. It is done.
The film thickness is usually 0.5 to 10 μm, preferably 1 to 5 μm.

(2) A step of drying (prebaking) the applied photosensitive resin composition layer by applying heat as necessary. The drying temperature is preferably 10 to 120 ° C, more preferably 12 to 90 ° C, particularly 15 to 60 ° C, particularly 20 to 50 ° C. The drying time is preferably 0.5 to 10 minutes, more preferably 1 to 8 minutes, and particularly preferably 2 to 5 minutes. Drying may be performed under reduced pressure or normal pressure, but reduced pressure is preferred. Moreover, although it may carry out in air or in an inert gas, it is preferably in an inert gas.

(3) A step of exposing the photosensitive resin composition layer with actinic rays through a predetermined photomask. If the photosensitive resin composition of the present invention, even in mask openings having a diameter of about 4 to 10 [mu] m ⁽² about area 12～100Myuemu), accurately, i.e. the diameter 5~12μm of (area 20 to 120 ²⁾ A pattern can be formed in a range.
Examples of the active light include visible light, ultraviolet light, and laser light. Examples of the light source include sunlight, a high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, and a semiconductor laser.
The exposure amount is not particularly limited, preferably 20~300mJ / cm ^2, more preferably 20~100mJ / cm ² from the viewpoint of production cost, 20~60mJ / cm ² is particularly preferred. In the step of performing exposure light, a component having a (meth) acryloyl group in the photosensitive resin composition reacts to undergo photocuring reaction.

(4) A step of developing after removing the unexposed portion with a developer after light irradiation. As the developer, an alkaline aqueous solution is usually used. Examples of the alkaline aqueous solution include aqueous solutions of alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; aqueous solutions of carbonates such as sodium carbonate, potassium carbonate and sodium hydrogencarbonate; hydroxytetramethylammonium and hydroxytetraethylammonium. And an aqueous solution of an organic alkali. These can be used alone or in combination of two or more kinds, and a surfactant such as an anionic surfactant, a cationic surfactant, an amphoteric surfactant and a nonionic surfactant can be added and used.
As a developing method, there are a dip method and a shower method, but the shower method is preferable. The temperature of the developer is preferably 25 to 40 ° C. The development time is appropriately determined according to the film thickness and the solubility of the photosensitive resin composition.

(5) Post-heating (post-baking) step. The post-baking temperature is 50 to 280 ° C, preferably 100 to 250 ° C, more preferably 120 to 240 ° C, and particularly preferably 140 to 230 ° C.
The post-bake time is 5 minutes to 2 hours.

Post bake may be performed under reduced pressure or normal pressure, but reduced pressure is preferred. Moreover, although it may carry out in air or in an inert gas, it is preferably in an inert gas.
By performing post-baking, the elastic recovery characteristics of the photo spacer are further improved.
In this post-heating (post-baking) step, it is presumed that the component having a thermosetting functional group in the photosensitive resin composition reacts and thermosets. As the thermosetting functional group, for example, among the hydrolyzable alkoxy group in (B) and the (meth) acryloyl group in (A) or (D), a trace amount remaining in the above exposure step (Meth) acryloyl group is mentioned.

Hereinafter, although an example and a comparative example explain the present invention further, the present invention is not limited to these. Hereinafter, unless otherwise specified, “%” represents “% by weight” and “parts” represents “parts by weight”.

[Production of polyfunctional (meth) acrylate having carboxylate]
Production Example 1
1-ethyl-3-methylimidazolium monomethyl carbonate was synthesized according to the method described in JP-A No. 2001-316372.
A polyfunctional acrylate having a carboxyl group [trade name “TO-1382”, manufactured by Toagosei Co., Ltd.] and the above 1-ethyl-3-methylimidazolium monomethyl carbonate are mixed in equimolar amounts to give 1-ethyl. -3-Methylimidazolium polyfunctional acrylate carboxylate salt (A-3) was obtained.

[Production of siloxane compound (B-1) having two or more hydrolyzable alkoxy groups]
Production Example 2
In a glass Kolben equipped with a heating / cooling / stirring measure, a reflux condenser, a dropping funnel and a nitrogen introduction pipe, 46 parts (0.2 mole part) 3-acryloyloxypropyltrimethoxysilane, 160 parts diphenyldimethoxysilane (0 .65 mol parts), 45 g (2.5 mol parts) of ion-exchanged water, and 0.1 part (0.001 mol parts) of oxalic acid, and heated and stirred at 60 ° C. for 6 hours. The methanol produced as a by-product by hydrolysis was removed under reduced pressure of 6.7 kPa over 2 hours to obtain acrylate-modified polysiloxane (B-1) (Mn: 2,100).

[Production of hydrophilic epoxy resin solution (D-1)]
Production Example 3
Glass Kolben equipped with heating / cooling / stirring measures, reflux condenser, dropping funnel and nitrogen inlet, cresol novolac epoxy resin “EOCN-102S” (Epoxy equivalent 200, Nippon Kayaku Co., Ltd.) and propylene 245 parts of glycol monomethyl ether acetate was charged and heated to 110 ° C. to dissolve uniformly. Subsequently, 76 parts of acrylic acid (1.07 mol part), 2 parts of triphenylphosphine and 0.2 part of p-methoxyphenol were charged and reacted at 110 ° C. for 10 hours.
The reaction product was further charged with 91 parts (0.60 mol part) of tetrahydrophthalic anhydride and further reacted at 90 ° C. for 5 hours. After that, propylene glycol monomethyl ether acetate was added, and the content of hydrophilic epoxy resin was 50%. Was diluted to obtain a 50% solution (D-1) of a hydrophilic epoxy resin having an acryloyl group and a carboxyl group.
In addition, it was number average molecular weight (Mn) by GPC as resin solid content conversion: 2,200, SP value: 11.3, HLB value: 6.4, and acid value: 91 mgKOH / g.

[Production of methacrylic acid copolymer solution]
Comparative production example 1
According to the method described in Synthesis Example 1 of JP-A-2009-75284, methacrylic acid, tricyclodecan-8-yl methacrylate, styrene, butadiene, and glycidyl methacrylate are reacted to produce these methacrylic acid copolymers. Of diethylene glycol methyl ethyl ether (F-1) was synthesized.

Comparative production example 2
According to the method described in Example 1 of JP2009-186838, methacrylic acid, dimethylbutyrolactone acrylate, and glycidyl methacrylate, these methacrylic acid copolymers 1-methoxy-2-propanol / 1-methoxy- A 2-propyl acetate solution (F-2) was synthesized.

[Production of cationic polymerization initiator solution]
Comparative production example 3
4- (Phenylthio) phenyldiphenylsulfonium tris (pentafluoroethyl) trifluorophosphate (F-3) was synthesized according to the method described in Examples of WO05 / 116038 pamphlet.

[Production of photosensitive resin composition]
Examples 1-14 and Comparative Examples 1-7
In accordance with the number of parts in Table 1 and Table 2, each component is charged into a glass container, stirred until uniform, and further diluted with propylene glycol monomethyl ether acetate so that the active ingredient concentration is 35%. The photosensitive resin composition of Examples 1-14 of this invention and the photosensitive resin composition of Comparative Examples 1-7 were obtained.

The symbols in Tables 1 and 2 are as follows.
(A-1): Polyfunctional (meth) acrylate having a carboxyl group: “Aronix M520” (manufactured by Toagosei Co., Ltd.)
(A-2): Polyfunctional (meth) acrylate having a carboxyl group: “Aronix M510” (manufactured by Toagosei Co., Ltd.)
(A-4): Polyfunctional (meth) acrylate having a phosphate group: “Light Ester P-2M” (manufactured by Kyoeisha Chemical Co., Ltd.)
(C-1): Photoradical polymerization initiator: “Irgacure 907” (2-methyl-1- (4- (methylthio) phenyl) -2-morpholino-1-propanone: manufactured by Ciba Specialty Chemicals Co., Ltd. )
(C-2): Photoradical polymerization initiator: “Irgacure OX02” (ethanone, 1- (9-ethyl-6- (2-methylbenzoyl) -9, H, -carbazol-3-yl)-, 1- (O-acetyloxime): Ciba Specialty Chemicals Co., Ltd.)
(C-3): Photoradical polymerization initiator: “Irgacure 379” (2-dimethylamino-2- (4-methyl-benzyl) -1- (4-morpholin-4-yl-phenyl) -butane-1- ON: Ciba Specialty Chemicals Co., Ltd.)
(C-4): Photoradical polymerization initiator: “CGI242” (1- (9- (2-methylbenzoyl) -9, H, -carbazol-3-yl) -1- (9- (2-methylbenzoyl) ) -9, H, -carbazol-3-yl) -ethanone, 1- (O-acetyloxime): Ciba Specialty Chemicals Co., Ltd.)
(E-1): Multifunctional (meth) acrylate: “NK ester A-TMM-3Lnew” (pentaerythritol triacrylate: manufactured by Shin-Nakamura Chemical Co., Ltd.)
(E-2): Multifunctional (meth) acrylate: “DA600” (mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate: manufactured by Sanyo Chemical Industries, Ltd.)

  About the photosensitive resin composition of Examples 1-14 of this invention, and the photosensitive resin composition of Comparative Examples 1-7, it is a method which shows alkali developability, adhesiveness with a board | substrate, an elastic recovery characteristic, and the resolution below. Measured and evaluated. The results are shown in Tables 1 and 2.

[Evaluation of alkali developability]
The photosensitive resin composition was spin-coated on a glass substrate so that the finished film thickness was 5 μm, and dried at 80 ° C. for 3 minutes. Light from a high-pressure mercury lamp was irradiated at 60 mJ / cm ² through a photomask having a pattern having many openings with a diameter of 6 to 20 μm. Note that the exposure (gap) between the photomask and the substrate was 100 μm.
Thereafter, shower development was performed for 30 seconds using a 1% sodium carbonate aqueous solution. After washing with water, post-baking was performed at 230 ° C. for 30 minutes to form a large number of photo spacers on the substrate.

Depending on the amount of residue (gel, solid such as oligomers and monomers remaining in 1% sodium carbonate aqueous solution) on the surface of these glass substrates on which photo spacers have been formed, developability is determined according to the following criteria. evaluated.
The substrate obtained by the above operation was photographed, and the residue on the substrate was quantitatively confirmed by image data processing. Judgment criteria are as follows.

◎: No residue on substrate ○: Residue on substrate is recognized but less than 5% △: Area covering residue of substrate on substrate is less than 5% to less than 75% × ⁽¹⁾ : Residue on substrate The area covering the substrate of the object is 75% or more × ⁽²⁾ : The spacer itself is washed away and hardly remains.

[Production of photo spacer]
The photosensitive resin composition was spin-coated on a glass substrate so that the finished film thickness was 5 μm, and dried at 80 ° C. for 3 minutes. Light from a high-pressure mercury lamp was irradiated at 60 mJ / cm ² through a photomask having a pattern having openings with a diameter of 6 μm to 20 μm. Note that the exposure (gap) between the photomask and the substrate was 100 μm.
Thereafter, shower development was performed for 60 seconds using a 1% aqueous sodium carbonate solution. After washing with water, post-baking was performed at 230 ° C. for 30 minutes to form a large number of photo spacers on the substrate.
In Comparative Examples 1 and 2, the alkali developability was poor and the spacer could not be formed. Therefore, the post-baking and subsequent processes were not performed, and the following evaluation was not performed.

In addition to the above photo spacers, the post-baking temperature was changed to 200 ° C., 150 ° C., 100 ° C., and 50 ° C., respectively. A large number of photo spacers were formed.

The lower base diameter of the photo spacer is the diameter of the portion where the spacer contacts the substrate, and the upper base diameter of the photo spacer is the diameter at a position 90% of the height of the spacer, respectively. Measurement was performed using a microscope VK-8700 (manufactured by Keyence Corporation).
The lower base diameters of the photo spacers prepared using the photosensitive resin compositions of Examples 1 to 14 and Comparative Examples 1 to 7 are in the range of 7 to 21 μm depending on the size of the mask. The upper base diameter was in the range of 4 to 19 μm.

[Evaluation of adhesion]
With the miniaturization and high definition of LCD, a size of 10 μm or less is required for the size of a photo spacer manufactured on a substrate. However, the smaller the ground contact area between the substrate and the photo spacer, the higher the adhesion is required. That is, a photo spacer having higher adhesion is more excellent in performance of being less likely to be peeled off by rubbing or the like even when the lower bottom diameter of the spacer is reduced. Therefore, the adhesiveness was evaluated by setting the lower bottom diameter of the spacer at two levels of 15 μm and 8 μm, and the following swab rubbing test.

A large number of photo spacers were formed on the substrate in the same manner as the photo spacers described above. Of these spacers, 100 arbitrary spacers were selected for determination with respect to photo spacers having a bottom diameter of 15 μm and 8 μm, respectively.
A cotton swab soaked in acetone was rubbed against the substrate on which the spacers were formed at a speed of 2 cm / second, 10 times in each direction, and then the peeling state of 100 arbitrary spacers existing on the substrate was observed with an optical microscope. Observed and evaluated for adhesion.
Judgment criteria are as follows.
A: No. of peeled spacers 0: No. of peeled spacers 1 to 3 Δ: No. of peeled spacers 4 to 89 x: No. of peeled spacers 90 to 100

[Resolution evaluation]
As the size and resolution of LCDs have been reduced and the pixel size has been reduced, patterning with a resolution of 10 μm or less has been required as a resolution. That is, the higher the resolution, the better the performance of forming a spacer having the same size as the remaining mask pattern even if the remaining mask pattern is smaller.
Therefore, the resolution was evaluated by setting the remaining pattern of the mask to a diameter of 10 μm and performing the following test.

A large number of photospacers were formed on a substrate in the same manner as in the production of the photospacer except that a photomask having a pattern having an opening having a diameter of 10 μm was used as the photomask. The lower base diameter of the photo spacer was measured with a laser microscope, and this was used as an evaluation of resolution. It can be said that the smaller the bottom diameter, the higher the resolution.

Criteria based on the lower base diameter of the spacer are as follows. The results are shown in Tables 1 and 2.
○: Less than 11 μm Δ: 11-13 μm
×: 13 μm or more

[Evaluation of elastic recovery characteristics]
The elastic recovery characteristic of the photo spacer can be evaluated by the “elastic recovery rate” when a certain pressure is applied. The higher the elastic recovery rate (%), the better the elastic recovery characteristics.
Further, when the pressure applied to the photospacer is large, the higher the elastic recovery rate, the better the elastic recovery characteristic.
In the present invention, the elastic recovery properties can be the following method is assessed by measuring the elastic recovery at pressure conditions of 2 levels of 0.3 mN / [mu] m ² and 0.5 mN / [mu] m ^2.

The photospacer obtained as described above was subjected to a constant load at 25 ° C. by using a Fischerscope H-100 (Fischer Instruments) hardness meter and a square indenter (50 μm × 50 μm) in cross section. speed (if pressure is ^{0.3mN / μm 2 0.010mN / μm 2} · sec, when the pressure of ^{0.5mN / μm 2 0.017mN / μm 2} · second), to a predetermined pressure over 30 seconds under pressure was maintained for 5 seconds, a constant unloading speed (if the pressure of ^{0.3mN / μm 2 0.010mN / μm 2} · sec, when the pressure of 0.5mN / μm ² 0.017mN / μm pressure over 30 seconds ² · sec) was unloading to 0, determine the total deformation amount T _{0 ([mu]} m) from the hysteresis curve of the load and the spacer deformation amount when held for 5 seconds, further plastic deformation T ([Mu] m) and asked to calculate elastic recovery at a given pressure (%) by the following equation.

Elastic recovery rate (%) = [(T ₀ −T ₁ ) / T ₀ ] × 100
As a pressure, a hysteresis curve was measured at a pressure of 0.3 mN / μm ² or 0.5 mN / μm ² , an elastic recovery rate was calculated, and an elastic recovery characteristic was evaluated.
The criteria for determining the elastic recovery rate are as follows.
A: 80% or more B: 70-80%
Δ: 60-70%
X: Less than 60%

As shown in Examples 1 to 14, the photosensitive resin composition for a photospacer of the present invention is excellent in all aspects of alkali developability, exposure sensitivity, resolution, adhesion to a substrate, and elastic recovery characteristics. Further, even when a low temperature treatment of 200 ° C. or lower is adopted after curing by light irradiation, the photospacer obtained by the present invention has excellent adhesion to the substrate and excellent elastic recovery characteristics.
On the other hand, in Comparative Example 1 in which the acid value of the photosensitive resin composition is low, there is a large amount of development residue, and a spacer cannot be formed. Spacers cannot be formed.
Further, even when the polyfunctional (meth) acrylate monomer of the present invention is used, Comparative Example 3 having a low (meth) acryloyl group concentration in the photosensitive resin composition is not satisfactory because of its low elastic recovery property. In Comparative Example 4 in which the polysiloxane compound which is an essential component of the present invention is not used, the adhesion to the substrate and the elastic recovery characteristics are low, which is not satisfactory. Similarly, even if the (meth) acryloyl group concentration is high, Comparative Example 5 in which the siloxane compound of the invention is not used is not satisfactory because of its low adhesion to the substrate and elastic recovery characteristics. In Comparative Examples 6 and 7, which do not use the polyfunctional (meth) acrylate monomer or siloxane compound of the invention, the adhesion to the substrate and the elastic recovery characteristics are low, which is not satisfactory. Moreover, when any of Comparative Examples 1 to 7 employs a low-temperature treatment, sufficient adhesion to the substrate and elastic recovery characteristics cannot be obtained, which is not satisfactory.

Since the photosensitive resin composition for photospacers of the present invention is excellent in alkali developability, exposure sensitivity, resolution, adhesion to a substrate, and elastic recovery characteristics, it is an overcoat agent for color filters, and other resist materials. For example, it is also useful as a photosensitive resin composition for uses such as a photo solder resist, a photosensitive resist film, a photo adhesive, or a hard coat agent.
Furthermore, even when low-temperature treatment is adopted, it has excellent adhesion to the substrate and elastic recovery characteristics, so it can be used as an overcoat agent for flexible displays, partition walls for organic EL elements, photosensitive insulating films for organic EL elements, organic It is also useful as a photosensitive resin composition for uses such as an overcoat agent for a moisture-proof barrier film of an EL element.

Claims (6)

  One or more functional groups selected from the group consisting of a carboxyl group, a sulfo group, a phosphate group, and a phosphate ester group, or a polyfunctional (meth) acrylate monomer (A) containing these salts, two or more A negative photosensitive resin composition capable of alkali development containing a siloxane compound (B) having a hydrolyzable alkoxy group and a radical photopolymerization initiator (C) as essential components. A carbon-carbon double bond in a (meth) acryloyl group having an acid value based on the total weight of (C) of 10 to 110 KOH mg / g and based on the total weight of (A) to (C) of the photosensitive resin composition Content of (C = C) is 6.5-10.0 mmol / g, The photosensitive resin composition (Q) for photospacers characterized by the above-mentioned. The photosensitive resin composition (Q) for a photospacer according to claim 1, wherein the elastic recovery rate of the photospacer formed by post-baking the cured product by light irradiation at 200 ° C or lower is 50% or more.   The photosensitive resin composition (Q) according to claim 1 or 2, wherein the siloxane compound (B) further contains a (meth) acryloyl group.   Based on the total weight of (A) to (C) of the photosensitive resin composition, the polyfunctional (meth) acrylate monomer (A) is 30 to 95% by weight, and the siloxane compound (B) is 1 to 40% by weight. The photosensitive resin composition (Q) according to any one of claims 1 to 3, comprising 1 to 15% by weight of the radical photopolymerization initiator (C).   Furthermore, the hydrophilic epoxy resin (D) having one or more (meth) acryloyl groups and one or more carboxyl groups in the molecule is based on the total weight of (A) to (D) of the photosensitive resin composition. And containing a carbon-carbon double bond (C = C) in the (meth) acryloyl group based on the total weight of (A) to (D) of the photosensitive resin composition. The amount (mmol / g) is 6.5-10.0 mmol / g, The photosensitive resin composition (Q) in any one of Claims 1-4.   A photospacer formed by curing the photosensitive resin composition according to claim 1.