JP2017173349A - Photosensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition exhibiting a high whiteness degree, a less yellowish hue, high resolution, and excellent adhesiveness in a cured product.SOLUTION: The photosensitive resin composition is alkali-developable and comprises, as essential components, a hydrophilic resin (A) having a radically polymerizable organic group, a colorant (B), a polyfunctional (meth)acrylate monomer (C), a photopolymerization initiator (D), and a white pigment (E), in which the colorant (B) is a metal salt (B1) of a (meth)acrylic acid or a metal salt (B2) of a compound having a (meth)acryloyl group and an acidic group.SELECTED DRAWING: None

Description

The present invention relates to a photosensitive resin composition containing a colorant.
More specifically, the present invention relates to a photosensitive resin composition that has an alkali development step during film formation of an opaque touch panel member such as a touch panel bezel and a backlight member such as a reflector, and forms a pattern in the alkali development step. .

In recent years, the use of touch panels has become common. In particular, the commercialization and rapid development of smartphones and tablet computers have led to the popularization and development of touch panels. In addition to the concept of touching and inputting, the touch panel device includes a concept that reflects the user's intuitive experience in the interface and further diversifies feedback for touch. In addition to being able to save space, touch panel devices can improve operability and simplicity, can easily change specifications, and are highly recognized by users. There are many advantages of being easily linked.

Due to such advantages, electronic devices can be used easily and quickly using a touch panel, and thus are widely used in various fields such as industry, transportation, service, medical care, and mobile. Such a touch panel device has been thinned in recent years, and for example, a front light-shielding layer called a bezel has also been thinned (Patent Document 1).

Recently, as a coating material for the bezel part, a light color coating composition such as white or pink having a low light shielding degree has been used. However, if the light shielding degree is low, the inside of the display is easily exposed through the bezel part. In order to obtain a sufficient light shielding degree there is a problem, a method of adding a step of thickening the film has been developed (Patent Document 2). However, since this method adds an extra step, a normal touch panel manufacturing process There is a problem that the coating film is not suitable and the coating film becomes yellow.

JP 2011-194799 A JP 2013-152039 A

An object of the present invention is to provide a photosensitive resin composition having a high degree of whiteness of a cured product, low yellowness, high resolution, and excellent adhesion.

The inventors of the present invention have reached the present invention as a result of studies to achieve the above object.
That is, the present invention relates to a hydrophilic resin (A) having a radical polymerizable organic group, a colorant (B), a polyfunctional (meth) acrylate monomer (C), a photopolymerization initiator (D), and a white pigment. A photosensitive resin composition containing (E) as an essential component, wherein the colorant (B) contains a (meth) acrylic acid metal salt (B1) or a (meth) acryloyl group and an acidic group.

The photosensitive resin composition of the present invention has an effect that a whiteness (L * value) is high, a yellowness (b * value) is low, a resolution is high, and a pattern having excellent adhesion can be formed. .

  The photosensitive resin composition of the present invention comprises a hydrophilic resin (A) having a radical polymerizable organic group, a colorant (B), a polyfunctional (meth) acrylate monomer (C), and a photopolymerization initiator (D ) And a white pigment (E) as essential components, wherein the colorant (B) is a (meth) acrylic acid metal salt (B1) or a (meth) acryloyl group and an acidic group. It is a metal salt (B2) of the compound containing this.

In this specification, “(meth) acrylate” means “acrylate or methacrylate”, “(meth) acrylic acid” means “acrylic acid or methacrylic acid”, and “(meth) acrylic resin” means “ “Acrylic resin or methacrylic resin”, “(meth) acryloyl group” means “acryloyl group or methacryloyl group”, and “(meth) acryloyloxy group” means “acryloyloxy group or methacryloyloxy group”.

In the present invention, the term “alkaline developable” means that the uncured portion can be removed cleanly with an alkaline aqueous solution of the developer in the step of removing the uncured portion using a developer.

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

The hydrophilicity index in the hydrophilic resin (A) having a radically polymerizable group, which is the first essential component in the present invention, is defined by HLB. Generally, the larger this value, the higher the hydrophilicity.
The HLB value of the hydrophilic resin (A) of the present invention is preferably 4 to 19, more preferably 5 to 19, and particularly preferably 6 to 19. When it is 4 or more, the developing property is further improved when developing the photospacer, and when it is 19 or less, the water resistance of the cured product is further improved.

Here, “HLB” is an index indicating a balance between hydrophilicity and lipophilicity, and is described in, for example, “Introduction to Surfactants” (published by Sanyo Chemical Industries, Ltd., 2007, Takehiko Fujimoto), page 212. It is known as the calculated value by the Oda method, not the 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.
The organic value and the inorganic value for deriving HLB = 10 × inorganic / organic HLB can be calculated by using the values in the table described in “Introduction of Surfactant” on page 213.

Further, the solubility parameter (hereinafter referred to as SP value) [(unit is (cal / cm ³ ) ^1/2 ]) of the hydrophilic resin (A) is preferably 7 to 14, more preferably 8 to 13, particularly preferably. Is from 9 to 13. If it is 7 or more, the developability can be further improved, and if it is 14 or less, the water resistance of the cured product is further improved.

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 hydrophilic resin (A) of the present invention has a radical polymerizable group contained in the molecule, and as the radical polymerizable group, from the viewpoint of photocurability, a (meth) acryloyl group, a vinyl group, and an allyl group. Is more preferable, and a (meth) acryloyl group is more preferable.

In addition, the functional group contributing to the hydrophilicity contained in the molecule of the hydrophilic resin (A) having a radical polymerizable group of the present invention is a carboxyl group, an epoxy group, a sulfonic acid group, a phosphorus group from the viewpoint of alkali developability. An acid group is preferable, and a carboxyl group is more preferable.

Specific examples of the hydrophilic resin (A) that can be used in the present invention include a hydrophilic epoxy resin (A1) having a radical polymerizable group and a hydrophilic (meth) acrylic resin (A2) having a radical polymerizable group. ) And the like.

The hydrophilic epoxy resin (A1) having a radical polymerizable group of the present invention is synthesized by reacting a commercially available epoxy resin with a compound having a radical polymerizable group and further reacting with a compound having a hydrophilic functional group. can do.
For example, a novolac type epoxy resin having an epoxy group in the molecule is reacted with (meth) acrylic acid, and further reacted with a polyvalent carboxylic acid such as phthalic acid or phthalic anhydride, or a polyvalent carboxylic acid anhydride.

  The hydrophilic (meth) acrylic resin (A2) having a radically polymerizable group of the present invention can be obtained by polymerizing a (meth) acrylic acid derivative by an existing method and further reacting a compound having a radically polymerizable group. it can.

As a method for producing the hydrophilic (meth) acrylic resin (A2), radical polymerization is preferable, and a solution polymerization method is preferable because the molecular weight can be easily adjusted.

  Examples of the monomer used for producing the hydrophilic (meth) acrylic resin (A2) include (meth) acrylic acid (a21) and (meth) acrylic acid ester (a22).

  Examples of the (meth) acrylate ester (a22) include methyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylate-2-ethylhexyl, hydroxyethyl (meth) acrylate, isobornyl (meth) acrylate, and the like. Preferably, it is methyl (meth) acrylate.

The number average molecular weight of the hydrophilic resin (A) of the present invention is usually 3,000 to 100,000, preferably 3,000 to 50,000.

The content of the hydrophilic resin (A) in the photosensitive resin composition of the present invention is 8 to 55% by weight, preferably 15 to 5% based on the total weight of (A) to (E) from the viewpoint of developability. 50% by weight.

The colorant (B), which is the second essential component of the present invention, is a metal salt (B1) of (meth) acrylic acid or a metal salt (B2) of a compound (b) containing a (meth) acryloyl group and an acidic group. However, as the metal salt, from the viewpoint of yellowness, a copper salt and a cobalt salt are preferable, and a copper salt is more preferable. In addition, the metal salt (B1) of (meth) acrylic acid itself is excluded from the classification of the metal salt (B2) of the compound (b) containing a (meth) acryloyl group and an acidic group.

In addition, the acidic group of the compound (b) having a (meth) acryloyl group and an acidic group, which is a constituent component of the metal salt (B2) of the present invention, is preferably a carboxyl group, a sulfonic acid group, or a phosphoric acid group, more preferably. It is a carboxyl group.

As the compound (b) containing a (meth) acryloyl group and an acidic group, examples of the compound having a carboxyl group in the acidic group include an epoxy resin and an acrylic resin containing a carboxyl group, and a sulfonic acid group in the acidic group. Examples of the compound having 2-acrylamido-2-methylpropanesulfonic acid include 2-acrylamido-2-methylpropanesulfonic acid, and examples of the compound having a phosphate group in the acidic group include 2- (meth) acryloyloxyethyl acid phosphate.

As the colorant of the present invention, an inorganic metal salt such as copper acetate (II) or basic copper carbonate (II) is reacted with a compound containing a (meth) acrylic acid or (meth) acryloyl group and an acidic group. Can be synthesized.

The content of the colorant (B) in the photosensitive resin composition of the present invention is 0.01 to 10% by weight based on the total weight of (A) to (E) from the viewpoints of transmittance and yellowness. Preferably it is 0.05-5 weight%.

The polyfunctional (meth) acrylate monomer (C), which is the third essential component of the present invention, is particularly limited as long as it is a monomer having a molecular weight of less than 3,000 and having two or more (meth) acryloyl groups. Used without.
As such a polyfunctional (meth) acrylate monomer (C), bifunctional (meth) acrylate (C1), trifunctional (meth) acrylate (C2), 4-6 functional (meth) acrylate (C3) and 7- 10 functional (meth) acrylate (C4) is mentioned.

Examples of the bifunctional (meth) acrylate (C1) include esterified products of polyhydric alcohol and (meth) acrylic acid [for example, di (meth) acrylate of glycol, di (meth) acrylate of glycerin, dimethyl of trimethylolpropane. (Meth) acrylate, di (meth) acrylate of 3-hydroxy-1,5-pentanediol, di (meth) acrylate of 2-hydroxy-2-ethyl-1,3-propanediol]; alkylene oxide of polyhydric alcohol Adducts and esterified products of (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) acryl Esters of acids and hydroxy carboxylic acids [e.g. hydroxypivalic acid neopentyl glycol di (meth) acrylate], and the like.
In addition, it is not necessary to make all the hydroxyl groups of a polyhydric alcohol react with (meth) acrylic acid, an alkylene oxide adduct, etc., and unreacted hydroxyl groups may remain.

Trifunctional (meth) acrylate (C2) includes tri (meth) acrylate of glycerin, tri (meth) acrylate of trimethylolpropane, tri (meth) acrylate of pentaerythritol; and trioxide of ethylene oxide adduct of trimethylolpropane. (Meth) acrylate etc. are mentioned.

Examples of tetra- to hexa-functional (meth) acrylate (C3) include pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate; dipentaerythritol ethylene oxide addition Tetra (meth) acrylate of a product, penta (meth) acrylate of an ethylene oxide adduct of dipentaerythritol, penta (meth) acrylate of a propylene oxide adduct of dipentaerythritol, and the like.

  Examples of the 7-10 functional (meth) acrylate compound include a compound obtained by reaction of dipentaerythritol penta (meth) acrylate and hexamethylene diisocyanate, and the like by reaction of a diisocyanate compound and a hydroxyl group-containing polyfunctional (meth) acrylate compound. Can be obtained.

  Of the polyfunctional (meth) acrylate monomer (C), from the viewpoint of curability, it is preferably a trifunctional or higher functional (meth) acrylate monomer, and more preferably a trifunctional or higher functional group having a glycerin, pentaerythritol or dipentaerythritol skeleton. It is a (meth) acrylate monomer.

The number average molecular weight of the polyfunctional (meth) acrylate monomer (C) is usually less than 3,000, preferably 500 to 2500.

  The content of the polyfunctional (meth) acrylate monomer (C) in the photosensitive resin composition of the present invention is 10 to 50% by weight based on the total weight of (A) to (E) from the viewpoint of curability. Preferably it is 20 to 45 weight%.

As the photoinitiator (D) which is the fourth essential component of the present invention, polymerization of the polymerizable unsaturated compound is initiated by exposure to radiation such as visible light, ultraviolet light, far infrared light, charged particle beam and X-ray. Any component that can generate a free radical may be used.

As the photopolymerization initiator (D), α-hydroxyalkylphenone type (D1) (for example, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, etc.); α- Aminoalkylphenone type (D2) (for example, (2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4- Morpholinophenyl) -butanone-1 etc .; thioxanthone compound type (D3) (eg (isopropylthioxanthone, diethylthioxanthone etc.); phosphate ester type (D4) (eg (2,4,6-trimethylbenzoyldiphenylphosphine) Oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide Acyl oxime type (D5) (for example, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], ethanone, 1- [9-ethyl- 6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime) etc.); benzyldimethyl ketal type (D6) etc .; benzophenone type (D7) (eg benzophenone, 4 -Benzoyl-4'-methyldiphenyl sulfide).

Of these, α-aminoalkylphenone is preferable from the viewpoint of curability of the cured product, and 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one is more preferable. 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1.

The usage-amount of a photoinitiator (D) is 2-15 weight% from a viewpoint of sclerosis | hardenability and coloring of hardened | cured material based on the sum total of (A)-(E), Preferably it is 5-10 weight%.

  The white pigment (E), which is the fifth essential component in the photosensitive resin composition of the present invention, is not limited in its type, but titanium oxide is generally used from the viewpoint of whiteness. Other white pigments commonly used in this field include C.I. I. Pigment white 4, 5, 6, 6: 1, 7, 18, 18: 1, 19, 20, 22, 25, 26, 27, 28, 32, and the like.

Since titanium oxide has different whiteness depending on the production method, it is preferable to select titanium oxide having high whiteness in order to improve reflectivity. Impurities of heavy metals and metal oxides mixed during the purification of titanium oxide have an adverse effect on whiteness, and coloring with Fe, Cr, Cu, Mn, V, Nb, etc. is particularly harmful. Therefore, it is preferable to limit heavy metal and metal oxide impurities to 0.1 wt% or less as impurities.

Titanium oxide having an impurity content of 0.1% by weight or less can be prepared by surface-treating rutile titanium oxide preferably made by a chlorine method with alumina, silica, zirconia, titania, organic matter, or the like.
The volume average particle diameter of the primary particles of the white pigment effective for improving the reflectance is 100 nm to 400 nm, preferably 150 to 350 nm. When the volume average particle size is less than 100 nm, the whiteness deteriorates, and when it exceeds 400 nm, the adhesion deteriorates.
In addition, the value measured with the laser diffraction / scattering type particle size distribution measuring apparatus is employ | adopted for the volume average particle diameter of the primary particle of this invention.

Examples of the chlorinated titanium oxide include Taipur R900 and R920 (manufactured by DuPont), Taipaque CR50, CR58, CR67, PFC-105 and PFC-107 (manufactured by Ishihara Sangyo).

Based on the content of (A) to (E) in the photosensitive resin composition of the present invention, the content of the white pigment (E) is 30 to 75% by weight, preferably 35 to 70% by weight.
If it is 30% by weight or more, the reflectance is good, and if it is 75% by weight or less, the handling property during coating can be further improved.

In addition to (A) to (E), the photosensitive resin composition of the present invention preferably further uses a compound (F) having a hydrolyzable alkoxy group for the purpose of further improving the adhesion.

Examples of the compound (F) having a hydrolyzable alkoxy group that can be used for this purpose include compounds having an alkoxy group such as alkoxytitanium, alkoxysilane, alkoxysiloxane, alkoxyaluminum, and alkoxyzirconia, and condensates thereof.

  Among them, for the purpose of improving adhesion, the compound (F) having a hydrolyzable alkoxy group is preferably alkoxysilane or alkoxysiloxane, more preferably a silane compound (F1) represented by the following general formula (1). And a siloxane compound (F2) which is a condensate thereof.

In the formula (1), R ¹ is one or more selected from the group consisting of a (meth) acryloyloxyalkyl group, a glycidoxyalkyl group, a mercaptoalkyl group, and an aminoalkyl group, and the carbon of the alkyl group An organic group having a number of 1 to 6 is represented.

R ² in formula (1) represents an alkyl group, an alicyclic saturated hydrocarbon group, or an aromatic hydrocarbon.

R ² alkyl groups include straight chain alkyl groups such as methyl, ethyl, n-propyl, n-butyl, n-octyl and n-dodecyl groups; branched groups such as isopropyl, isobutyl, sec-butyl and 2-ethylhexyl groups. An alkyl group is 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.

Examples of the aromatic hydrocarbon group include an aryl group, an aralkyl group, and an alkylaryl group.
Examples of the aryl group include phenyl, biphenyl, and naphthyl groups; examples of the aralkyl group include tolyl, xylyl, and examples of the mesitylalkylaryl group include methylphenyl and ethylphenyl groups.

R ² is preferably a linear alkyl group, branched alkyl group and aryl group from the viewpoint of curing reactivity, more preferably a linear alkyl group and an aryl group, particularly preferably a methyl group, an ethyl group, a phenyl group and These are combined.

R ³ in the formula (1) represents an alkyl group having 1 to 4 carbon atoms, and when there are a plurality thereof, they may be the same or different. M is 0 or 1.
Examples of R ³ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a sec-butyl group, and a methyl group and an ethyl group are preferable from the viewpoint of thermosetting reactivity. .

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

When m is 1, that is, as a trifunctional silane compound having two alkoxy groups, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-acryloyloxypropylmethyldimethoxysilane , 3-acryloyloxypropylmethyldiethoxysilane and the like.

Examples of the silane compound having a glycidoxyalkyl group as R ¹ include the following compounds.
Examples of the trifunctional silane compound having 3 alkoxy groups when m is 0 include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and the like.
When m is 1, that is, as a trifunctional silane compound having two alkoxy groups, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane and the like can be mentioned.

Examples of the silane compound having a mercaptoalkyl group as R ¹ include the following compounds.
When m is 0, that is, examples of the trifunctional silane compound having three alkoxy groups include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and the like.
When m is 1, that is, examples of the trifunctional silane compound having two alkoxy groups include 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, and the like.

Examples of the silane compound having an aminoalkyl group as R ¹ include the following compounds.
When m is 0, that is, as a trifunctional silane compound having three alkoxy groups, N-2 aminoethyl γ-aminopropyltrimethoxysilane, N-2 aminoethyl γ-aminopropyltriethoxysilane, 3-aminopropyl Examples include trimethoxysilane and 3-aminopropyltriethoxysilane.
When m is 1, that is, as a trifunctional silane compound having two alkoxy groups, N-2 aminoethyl γ-aminopropylmethyldimethoxysilane, N-2 aminoethyl γ-aminopropylmethyldiethoxysilane, 3-amino Examples thereof include propylmethyldimethoxysilane and 3-aminopropylmethyldiethoxysilane.

Among the silane compounds (F1) represented by the general formula (1), a trifunctional silane compound having a (meth) acryloyloxyalkyl group having three alkoxy groups and (meth) acryloyloxyalkyl is preferable. A condensate having a trifunctional silane compound having a group as an essential constituent monomer and a condensate having a trifunctional silane compound having a glycidoxyalkyl group having three alkoxy groups as an essential constituent monomer, and more preferable. Is a condensate containing 3- (meth) acryloxypropyltrimethoxysilane and 3- (meth) acryloyloxypropyltrimethoxysilane as essential constituent monomers.

The polysiloxane compound (F2) of the present invention is a condensate of the silane compound (F1) represented by the general formula (1) and can be obtained by a known method such as a condensation reaction using an acid catalyst. .
As the raw material silane compound, one kind may be used alone, or two or more kinds may be used in combination.

The amount of the compound (F) having a hydrolyzable alkoxy group is 0.1 to 20% by weight, preferably 1 to 15% by weight based on the total of (A) to (E) from the viewpoint of adhesion. is there.

A monofunctional (meth) acrylate (G) may be used in combination with the photosensitive resin composition of the present invention.
As such a monofunctional (meth) acrylate (G), a monofunctional (meth) acrylate having a phosphate group, a carboxyl group, or a hydroxyl group in the molecule is preferable, and more preferably a monofunctional (meth) having a phosphate group. Acrylate.
Examples of the (meth) acrylate having a phosphoric acid group include 2- (meth) acryloyloxyethyl acid phosphate. Examples of the (meth) acrylate containing a hydroxyl group include hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate.

  The photosensitive resin composition of the present invention may contain a leveling agent (H), an anionic surfactant, a cationic surfactant, a nonionic surfactant, an amphoteric surfactant, a fluorine-based interface. Examples include activators and silicon surfactants. Of these, fluorine surfactants and silicon surfactants are preferable from the viewpoint of coatability, and surfactants having an oxyalkyl chain are preferable from the viewpoint of compatibility.

  The photosensitive resin composition of the present invention may contain an antioxidant (I), and examples thereof include phenol-based antioxidants, sulfur-based antioxidants, and amine-based antioxidants. Among these, from the viewpoint of photocurability and antioxidant ability, phenolic antioxidants are preferable, and 2,6-di-t-butyl-4-methylphenol (BHT) and 2-t-butyl are particularly preferable. -6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2- [1- (2-hydroxy-3,5-di-t-pentylphenyl) ethyl]- 4,6-di-t-pentylphenyl acrylate, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) -propionate (Irganox 1076), thiodiethylene bis [3- (3 , 5-di-t-butyl-4-hydroxyphenyl) propionate (Irganox 1035), ethylenebis (oxyethylene) bis [3- (5-tert Butyl-4-hydroxy-m-tolyl) propionate] (Irganox 245), hexamethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate (Irganox 259), pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (Irganox 1010).

  The photosensitive resin composition of the present invention may contain a solvent, such as a ketone solvent (such as cyclohexanone), an ether solvent (including an ether ester solvent and an ether alcohol solvent) (such as propylene glycol monomethyl ether acetate and methoxybutyl acetate). , Ester solvents (such as butyl acetate), ether solvents (such as ether ester solvents and ether alcohol solvents), alcohol solvents (including ketone alcohol solvents) (such as 1.3-butylene glycol and diacetone alcohol), ester solvents (ethyl lactate) Etc.), ketone solvents (acetone, methyl ethyl ketone, etc.) and the like.

The photosensitive resin composition 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 has a viscosity of 1 to 200 mPa · s, preferably 2 to 150 mPa · s at 25 ° C.

A preferable forming step of obtaining a cured product from the photosensitive resin composition of the present invention is a step of applying a photosensitive resin composition on a substrate, irradiating with light, forming a pattern by alkali development, and performing post-baking. .
Although formation of hardened | cured material is normally performed at the process of (1)-(5) below, it is not limited to this.

The process coating method for applying the photosensitive resin composition of the present invention on a substrate includes roll coating, spin coating, spray coating, slit coating, and the like. Examples of the coating apparatus include a spin coater, an air knife coater, Examples include roll coaters, bar coaters, die coaters, curtain coaters, gravure coaters, and comma coaters.
The film thickness is preferably 0.5 to 100 μm.

(2) The applied photosensitive resin composition layer is dried by applying heat as necessary (prebaking). The drying temperature is preferably 20 to 120 ° C, more preferably 30 to 110 ° C.
The drying time is preferably 0.5 to 10 minutes, more preferably 1 to 8 minutes, and particularly preferably 1 to 5 minutes. Drying may be performed under reduced pressure or normal pressure.

(3) The process actinic ray that exposes the photosensitive resin composition layer with actinic rays through a predetermined photomask includes, for example, visible rays, ultraviolet rays, and laser rays.
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.
Although it does not specifically limit as an exposure amount, Preferably it is 20-300 mJ / cm < ² >, and 20-100 mJ / cm < ² > is more preferable from a viewpoint of production cost. In the step of performing exposure, a component having a (meth) acryloyl group in the photosensitive resin composition reacts to undergo photocuring reaction.

(4) After light irradiation, an unexposed portion is removed with a developer and development is performed. 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 20 to 45 ° 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 150 ° C, preferably 100 to 120 ° C, more preferably 110 to 130 ° C.
The post-baking time is 5 minutes to 2 hours, preferably 10 minutes to 1 hour, and more preferably 15 minutes to 45 minutes.

  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 Example 1 [Production of hydrophilic acrylic resin (A-1) having a methacryloyl group]
172 parts of propylene glycol monomethyl ether acetate was charged into a glass Kolben equipped with a heating / cooling / stirring device, a reflux condenser, a dropping funnel, and a nitrogen introduction tube, and heated to 90 ° C. A solution in which 177 parts of methacrylic acid, 13 parts of methyl methacrylate, 395 parts of isobornyl methacrylate, and 207 parts of propylene glycol monomethyl ether acetate were uniformly mixed, and dimethyl-2,2′-azobis (2-methylpropionate) A solution in which 5 parts and 12 parts of propylene glycol monomethyl ether acetate were uniformly mixed was dropped, and radical polymerization was performed in glass Kolben to obtain a reaction product.
The reaction product was further charged with 19 parts of glycidyl methacrylate, reacted at 90 ° C. for 5 hours, and then diluted with propylene glycol monomethyl ether acetate so that the resin concentration became 50% by weight to have the methacryloyl group of the present invention. A 50% propylene glycol monomethyl ether acetate solution of the hydrophilic acrylic resin (A-1) was obtained.
The acid value in terms of pure content of this resin was 100.2. The number average molecular weight (Mn) by GPC was 5,800. The SP value was 10.5 and the HLB value was 5.8.

Production Example 2 [Production of hydrophilic epoxy resin (A-2) having acryloyl group]
A glass Kolben equipped with a heating / cooling / stirring device, a reflux condenser, a dropping funnel and a nitrogen introduction tube, cresol novolac type epoxy resin “EOCN-102S” (Epoxy equivalent 200 from 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 mole part) of tetrahydrophthalic anhydride, reacted at 90 ° C. for 5 hours, and then diluted with propylene glycol monomethyl ether acetate to a resin concentration of 50% by weight. A 50% propylene glycol monomethyl ether acetate solution of a hydrophilic carboxyl group-containing cresol novolac type epoxy resin (A-2) having an acryloyl group of the present invention was obtained.
The acid value in terms of pure content of this resin was 88.4. The number average molecular weight (Mn) by GPC was 3,200. The SP value was 11.3 and the HLB value was 6.4.

Comparative Production Example 1 [Production of hydrophilic acrylic resin (A′-1) having no radically polymerizable group]
172 parts of propylene glycol monomethyl ether acetate was charged into a glass Kolben equipped with a heating / cooling / stirring device, a reflux condenser, a dropping funnel, and a nitrogen introduction tube, and heated to 90 ° C.
A solution in which 177 parts of methacrylic acid, 13 parts of methyl methacrylate, 395 parts of isobornyl methacrylate, and 207 parts of propylene glycol monomethyl ether acetate were uniformly mixed, and dimethyl-2,2′-azobis (2-methylpropionate) A solution in which 5 parts and 12 parts of propylene glycol monomethyl ether acetate were uniformly mixed was dropped, and radical polymerization was performed in glass Kolben to obtain a reaction product.
Thereafter, the resin was diluted with propylene glycol monomethyl ether acetate so that the resin concentration became 50% by weight to obtain a 50% propylene glycol monomethyl ether acetate solution of acrylic resin (A′-1). In addition, this acrylic resin (A'-1) does not have a radically polymerizable group.
The acid value in terms of pure content of this resin was 100.2. The number average molecular weight (Mn) by GPC was 5,500. The SP value was 135.7 and the HLB value was 5.5.

Production Example 3 [Production of Acrylic Acid Copper Salt (B1-1)]
A glass Kolben equipped with a heating / cooling / stirring device is mixed with 10.0 parts of basic copper carbonate (II) and 151.0 parts of acrylic acid as a copper salt and heated to 90 ° C. to heat the copper salt of acrylic acid. A blue liquid (B1-1) was obtained.

Production Example 4 [Metal salt having acryloyl group and carboxyl group (B2-1)]
A glass Kolben equipped with a heating / cooling / stirring device is mixed with 100 parts of basic copper carbonate (II) as a copper salt and 100 parts of a hydrophilic epoxy resin (A-2) having an acryloyl group and heated to 90 ° C. Thus, a blue liquid of a metal salt (B2-1) having an acryloyl group and a carboxyl group was obtained.

Production Example 5 [Metal salt having methacryloyl group and phosphate group (B2-2)]
A glass Kolben equipped with a heating / cooling / stirring device, 100 parts of copper (II) acetate as a copper salt, a compound having a methacryloyl group and a phosphate group, a methacryl-modified phosphate (trade name: KAYAMER PM-21, Japan 600 parts of Kayaku Co., Ltd.) were mixed and heated to 90 ° C. to obtain a blue liquid of a metal salt (B2-2) having a methacryloyl group and a phosphate group.

Production Example 6 [Production of Titanium Oxide Dispersion (E-1)]
A SUS flask equipped with a stirrer was charged with 500 parts of propylene glycol monomethyl ether acetate and 80 parts of phosphoric acid polyester (trade name: DISPERBYK-111, manufactured by Big Chemie Japan Co., Ltd.) as a dispersing agent. Here, 420 parts of titanium oxide (trade name: PFC-107, volume average particle diameter of primary particles according to catalog description value: 250 nm, manufactured by Ishihara Sangyo Co., Ltd.) whose surface was treated with an inorganic material were charged and stirred and dispersed.
This dispersed liquid was transferred to a 250 mL plastic container, and zirconia beads having a particle diameter of 1 mm were further charged therein and dispersed for 1 hour using a paint shaker.
After completion of the dispersion, the zirconia beads were removed by filtration with 300 mesh to obtain a 50% titanium oxide dispersion (E-1).

Production Example 7 [Production of Titanium Oxide Dispersion (E-2)]
Except that the titanium oxide of Production Example 6 was changed from a surface inorganic treatment product to a surface organic treatment product (trade name: D-2667, volume average particle diameter of primary particles according to catalog description value: 260 nm, manufactured by Sakai Chemical Co., Ltd.) Was a method similar to Production Example 3 to obtain a 50% titanium oxide dispersion (E-2).

Example 1
(A-1), (B1-1), (C-1), (D-1), (D-2), (E-1) in a glass container according to the number of parts (parts by weight) in Table 1. ), (G-1), (H-1), (I-1), and a solvent were added and stirred until uniform to obtain a photosensitive resin composition of Example 1.

Examples 2-7 and Comparative Examples 1-6
By the same operation, photosensitive resin compositions of Examples 2 to 7 and Comparative Examples 1 to 6 were obtained with the number of blending parts in Table 1.

The details of the abbreviated chemicals in Table 1 are as follows.
(B′-1): Basic copper carbonate (II)
(C-1): “Neomer DA-600” [Dipentaerythritol pentaacrylate: manufactured by Sanyo Chemical Industries, Ltd .; 6 functional groups]
(C-2): “Neomer EA-300” [Pentaerythritol tetraacrylate: manufactured by Sanyo Chemical Industries, Ltd .; 4 functional groups]
(C-3): “SR-9035” [ethoxylated (15) trimethylolpropane triacrylate: manufactured by Sartomer; functional group number: 3]

(D-1): “Irgacure 819” [Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide: manufactured by BASF Corporation)]
(D-2): “Irgacure 907” [2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one: manufactured by BASF Corporation]
(D-3): “Lucirin TPO” [(2,4,6-trimethylbenzoyl) -diphenylphosphine oxide: manufactured by BASF Corporation)]
(F1-1): “Silane coupling agent KBM-5103” (3-acryloxypropyltrimethoxysilane: manufactured by Shin-Etsu Chemical Co., Ltd.)
(F2-1): “KR-513” (acryl-modified alkoxypolysiloxane: manufactured by Shin-Etsu Chemical Co., Ltd.)
(G-1): “Light acrylate PO-A” [phenoxyethyl acrylate: manufactured by Kyoeisha Chemical Co., Ltd .; one functional group]
(G-2): “KAYAMER PM-21” [acrylic modified phosphate (2-acryloyloxyethyl acid phosphate): manufactured by Nippon Kayaku Co., Ltd .; one functional group]
(H-1): “KF-352A” [polydimethylsiloxane having an oxyalkylene chain: manufactured by Shin-Etsu Chemical Co., Ltd.]
(H-2): “Surflon S-386” [fluorine compound having an oxyalkylene chain: manufactured by AGC Seimi Chemical Co., Ltd.]
(I-1): Pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] [“Irganox 1010”: manufactured by BASF Japan Ltd.]

The physical property measurement and performance evaluation of the whiteness, yellowness, resolution, and adhesiveness of the cured products of the photosensitive resin compositions of Examples 1 to 7 and Comparative Examples 1 to 6 were performed.

<Evaluation of whiteness and yellowness>
[Creation of substrates for measuring whiteness and yellowness]
It apply | coated with the spin coater on the 10 cm x 10 cm square glass substrate, and the coating film with a dry film thickness of 20 micrometers was formed. This coating film was completely dried under reduced pressure and then heated on a hot plate at 80 ° C. for 3 minutes.
The obtained coating film is cured by irradiation with light of an ultrahigh pressure mercury lamp at 100 mJ / cm ² (illuminance 22 mW / cm ^{2 in} terms of i-line), and further heated at 230 ° C. for 30 minutes to obtain whiteness and yellowness. A measurement substrate was prepared.

Using the spectrocolorimeter ("Konica Minolta's" CM3700d "manufactured by Konica Minolta, light source C) used for measuring the object color in accordance with JIS Z 8722, the above cured product was measured for whiteness (L *) and yellowness ( b *) was measured.
When used for the bezel portion of the touch panel, if L * is 90 or more, sufficient whiteness is obtained. If b * is 0 or less, the yellowness is sufficiently low and there is no practical problem.

<Evaluation of resolution>
[Preparation of resolution confirmation cured pattern]
A 10 cm × 10 cm square glass substrate was coated with a spin coater and dried to form a coating film having a dry film thickness of 5 μm. This coating film was heated on a hot plate at 80 ° C. for 3 minutes to completely evaporate the solvent.
The dried coating film thus obtained was irradiated with 100 mJ / cm ^{2 of} light from an ultrahigh pressure mercury lamp through a line forming mask in which 100 openings having a length of about 2 cm and a width of 50 μm were cut every 100 μm (line i). Illuminance 22 mW / cm ^{2 in} terms of conversion). In addition, the exposure (exposure gap) between the mask and the substrate was 100 μm.
Thereafter, alkali development was performed using a 0.05% aqueous KOH solution. After washing with water, post-baking was performed at 150 ° C. for 30 minutes to form 100 rectangular patterns on a glass substrate every 100 μm.

[Resolution evaluation]
The resolution was evaluated by measuring the width of the pattern and how close it was to the mask opening diameter of 50 μm. In this evaluation method and conditions (mask opening diameter), generally 80 μm or less is required.

<Evaluation of adhesion>
In accordance with JIS K 5600-5-6, the conductive cured film is cut into a 1 mm width with a cutter knife so as to form 100 (10 × 10) cells, and the resin adhesion is measured.
The measurement result is “the grid remaining on the base film after the test / 100” and is represented by the following criteria.
○: The squares remaining on the film after the test are 100/100
X: The grid remaining on the film after the test was 99/100 or less

As shown in Table 1, the photosensitive resin compositions of Examples 1 to 7 of the present invention are excellent in all points of whiteness, yellowness, resolution, and adhesion.
On the other hand, in Comparative Example 1 in which a hydrophilic resin (A) having a radical polymerizable group is not used, and in Comparative Example 2 in which a hydrophilic resin not containing a polymerizable group is used instead of (A), resolution and adhesion are poor. is there. In Comparative Example 3 using a metal salt that does not contain a (meth) acryloyl group, the yellowness deteriorates. In Comparative Example 4 in which the polyfunctional (meth) acrylate (C) is not used and in Comparative Example 5 in which a monofunctional methacrylate is used instead of the polyfunctional (meth) acrylate, adhesion is poor. In Comparative Example 6 in which the white pigment (E) is not used, the whiteness is deteriorated.

Since the photosensitive resin composition of the present invention is excellent in whiteness, yellowness, resolution and adhesion, it is suitable as an opaque touch panel member such as a bezel for a touch panel and a backlight member such as a reflector used in a display. Can be used for

Claims (7)

  The hydrophilic resin (A) having a radical polymerizable organic group, a colorant (B), a polyfunctional (meth) acrylate monomer (C), a photopolymerization initiator (D), and a white pigment (E) are essential. A photosensitive resin composition contained as a component, wherein the colorant (B) is a metal salt (B1) of (meth) acrylic acid or a metal salt (B2) of a compound containing a (meth) acryloyl group and an acidic group A photosensitive resin composition characterized by being.   The photosensitive resin composition of Claim 1 whose metal of the metal salt of a coloring agent (B) is copper or cobalt.   The photosensitive resin composition according to claim 1 or 2, wherein the content of the colorant (B) is 0.01 to 10% by weight based on the total weight of (A) to (E). Furthermore, the photosensitive resin composition in any one of Claims 1-3 containing the compound (F) which has a hydrolysable alkoxy group. The photosensitive resin composition according to claim 4, wherein the hydrolyzable alkoxy group-containing compound (F) is a silane compound (F1) represented by the following general formula (1) or a polysiloxane compound (F2) that is a condensate thereof. object.
[Wherein, R ¹ is one selected from the group consisting of a (meth) acryloyloxyalkyl group, a glycidylalkyl group, a mercaptoalkyl group, and an aminoalkyl group, and the alkyl group has 1 to 6 carbon atoms. Represents an organic group. R ² represents an alkyl group, an alicyclic saturated hydrocarbon group, or an aromatic hydrocarbon group. R ³ represents an alkyl group having 1 to 4 carbon atoms, and when there are a plurality of R ^{3 s} , they may be the same or different. m is an integer of 0 or 1. ] The photosensitive resin composition according to any one of claims 1 to 5, wherein the primary particle diameter of the white pigment (E) is 100 nm to 400 nm. Hardened | cured material formed by hardening the photosensitive resin composition in any one of Claims 1-6.