JP2018173631A - Photosensitive resin composition, light-shielding film, liquid crystal display device, and method for manufacturing liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition capable of obtaining a spacer which is excellent in spacer characteristics such as a compression ratio, an elastic recovery ratio and breaking strength while maintaining light shielding properties and insulation properties, enables formation of a step of ΔH, and has an excellent pattern shape.SOLUTION: A photosensitive resin composition contains components (A) to (E) as essential components. The photosensitive resin composition for a light-shielding film having a spacer function contains (A) a polymerizable unsaturated group-containing alkali soluble resin, (B) a photopolymerizable monomer having at least three ethylenic unsaturated bonds, (C) a photopolymerization initiator, (D) a light-shielding component containing insulating carbon black having surface resistivity of a film produced so that optical density is 4/μm of 1×10Ω/sq. or more, and (E) a solvent, and pencil hardness of a cured product of the composition excluding the component (D) is HB or higher.SELECTED DRAWING: None

Description

  The present invention relates to a photosensitive resin composition and a light-shielding film obtained by curing the photosensitive resin composition. Specifically, in a liquid crystal display device, a black column spacer having a spacer function and a black matrix function can be formed by a photolithography method. The present invention relates to a photosensitive resin composition and a cured film thereof. The present invention further relates to a liquid crystal display device using a black column spacer obtained by curing. The present invention further relates to a method for manufacturing the liquid crystal display device.

  In recent years, color liquid crystal display devices (LCDs) have been used in various fields such as liquid crystal televisions, liquid crystal monitors, and color liquid crystal mobile phones. Among these, in order to improve the performance of LCDs, improvements aimed at improving characteristics such as viewing angle, contrast, response speed, etc. are being actively carried out, and there are various thin film transistors (TFT) -LCDs that are widely used at present. Panel structures have been developed. As for TFT-LCD, a method of manufacturing an array substrate and a color filter substrate on which a conventional TFT is formed and bonding the substrates while keeping them at a constant interval with a spacer has been mainly employed.

  The spacer that functions to keep the thickness of the liquid crystal layer (the distance between the array substrate and the color filter (CF) substrate in the conventional method), which is one factor affecting the performance of the LCD, constant is conventionally constant. A method of sandwiching a ball spacer having a particle size was used. However, this method has a problem that the amount of transmitted light for each pixel is not constant because the dispersion state of the ball spacers is not uniform. In order to solve this problem, a method of forming column spacers by photolithography is employed. However, column spacers formed by photolithography are often transparent, and light incident from an oblique direction affects the electrical characteristics of TFTs and degrades display quality. There is a problem. To solve such a problem, an LCD panel structure using a light-shielding column spacer, which is a light-shielding film having a spacer function formed by a photolithography method, has been proposed (Patent Document 1).

  This light-shielding column spacer needs a film thickness of about 1 to 7 μm in order to function as a spacer. In addition, it is necessary that light-shielding column spacers having different heights can be formed at the same time at locations where TFTs are formed and other locations. Further, the light-shielding column spacer is also required to have an elastic modulus, a deformation amount, an elastic recovery rate and the like within a proper range as a spacer function (Patent Document 3). Furthermore, light-shielding column spacers are also required to improve the reduction of curable components by adding a light-shielding component (colorant) to the spacer and the loss of electrical properties due to the effects of impurities in the colorant. (Patent Document 4).

Japanese Patent Application Laid-Open No. 08-234212 US Patent Application Publication No. 2009/030303407 JP 2009-031778 A International Publication No. 2013/062011

  In Patent Document 4, a mixed color organic pigment is used, but the optical density of the light-shielding column spacer is not shown. Mixed color organic pigments are more effective in lowering the dielectric constant than inorganic pigments such as carbon black, but often have low light shielding properties. Further, since it is necessary to form spacers having different heights at the same time, the light-shielding column spacer is further required to have mechanical properties such as a compressibility, an elastic recovery rate, and a breaking strength. Since the shape and mechanical characteristics of such a spacer are greatly affected by the light shielding component, it is difficult to design a photosensitive resin composition for the light shielding film. For this reason, the shape and mechanical properties of spacers using carbon black, mixed color organic pigments, etc. are still not sufficient, and further improvements are necessary.

  As described above, the light-shielding column spacer is manufactured with a film thickness of about 1 to 7 μm. With recent miniaturization of liquid crystal display elements, it is desired that a light-shielding column spacer can be formed in a fine spacer shape even when the film thickness is about 1 to 7 μm. In addition, in order to bond the two substrates sandwiching the liquid crystal layer with high accuracy, that is, with the functions of a black matrix and a spacer, that is, in order to increase alignment accuracy, two types of light-shielding spacer heights are provided (steps of ΔH There are many demands for patterning characteristics such as forming a light-shielding spacer that is as vertical as possible from the glass substrate, and it is difficult to satisfy all the required characteristics.

  The present invention has been made in view of the above problems, and it is possible to form a light-shielding film having a high light-shielding property and insulating property, and having a spacer function excellent in compressibility, elastic recovery rate, and breaking strength. A photosensitive resin composition capable of forming a step difference of ΔH and capable of forming an excellent pattern shape, a light shielding film having a spacer function formed using the same, and a liquid crystal display device including the light shielding film as a constituent element It is to provide.

  As a result of investigations to solve the above-described problems in the photosensitive resin composition for the light shielding film, the present inventors have determined that the specific colorant is the light shielding material for the photosensitive resin composition for the light shielding film. It was found that it is suitable as a component, and the present invention was completed.

(1) The present invention is a photosensitive resin composition for a light-shielding film having a spacer function, comprising the following components (A) to (E) as essential components: Saturated group-containing alkali-soluble resin, (B) a photopolymerizable monomer having at least three ethylenically unsaturated bonds, (C) a photopolymerization initiator, and (D) an optical density of 4 / μm. The pencil hardness of the cured product of the composition excluding the light-shielding component including insulating carbon black having a surface resistivity of 1 × 10 ⁸ Ω / □ or more and (E) solvent and (D) component is HB or more. It is a photosensitive resin composition characterized by being.
(2) In the present invention, the component (B) is 5 to 400 parts by mass with respect to 100 parts by mass of the component (A), and the component (C) is added to 100 parts by mass of the total amount of the components (A) and (B). On the other hand, 0.1 to 40 parts by mass, including the component (B) that becomes a solid content after photocuring, and the component excluding the component (E) as a solid content, the component (D) is included in the total amount of the solid content. The photosensitive resin composition according to (1), which is contained in an amount of 5 to 60% by mass.
(3) The present invention also uses a polymerizable unsaturated group-containing alkali-soluble resin represented by the general formula (II) as the component (A), as described in (1) or (2) It is a photosensitive resin composition.

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

(4) The photosensitive resin according to any one of (1) to (3), further comprising (G) an epoxy resin or an epoxy compound having two or more epoxy groups. It is a composition.
(5) The present invention is also a light-shielding film having an optical density OD of 0.5 / μm or more and 4 / μm or less, having a volume resistivity of 1 × 10 ⁹ Ω · cm or more when a voltage of 10 V is applied, and a dielectric The photosensitive resin composition according to any one of (1) to (4), wherein a light-shielding film having a rate of 2 to 10 can be formed.
(6) The present invention is also characterized in that a light-shielding film satisfying at least one of the following (i) to (iii) can be formed in a load-unloading test using a microhardness meter: It is the photosensitive resin composition in any one of 5). (I) The compression rate is 40% or less, (ii) The elastic recovery rate is 30% or more, and (iii) The fracture strength is 200 mN or more.
(7) The present invention is also a light-shielding film having a spacer function, which is formed by curing the photosensitive resin composition according to any one of (1) to (6).
(8) The present invention also provides a liquid crystal display device comprising the light shielding film according to (7) as a black column spacer (BCS).
(9) The present invention is also the liquid crystal display device according to (8), further comprising a thin film transistor (TFT).
(10) The present invention is also formed on a substrate, wherein the photosensitive resin composition according to any one of (1) to (6) is applied to a substrate, and the photosensitive resin composition is cured by light irradiation. In the manufacturing method of the light shielding film, for the film thickness H1 for setting the optical density as the light shielding film to 0.5 / μm or more and 4 / μm or less, and for the film thickness H2 of the light shielding film having the spacer function, H2 is 1 to 1. When the thickness is 7 μm, a light shielding film having a film thickness H1 and a film thickness H2 having ΔH = H2−H1 of 0.1 to 6.9 is formed at the same time.
(11) The present invention is also a method for manufacturing a liquid crystal display device, wherein the light-shielding film manufactured by the method according to (10) is used as a black column spacer.
(12) The present invention is also the manufacturing method according to (11), wherein the liquid crystal display device includes a thin film transistor (TFT).

  Since the photosensitive resin composition for a light-shielding film according to the present invention contains a specific insulating carbon black as a colorant, the compression ratio is maintained while maintaining light-shielding properties and insulating properties as compared with conventional photosensitive resin compositions. A cured product excellent in elastic recovery rate and breaking strength can be obtained. Furthermore, the photosensitive resin composition for a light-shielding film according to the present invention can form a fine spacer shape even when the film thickness is about 1 to 7 μm.

Hereinafter, the present invention will be described in detail.
The polymerizable unsaturated group-containing alkali-soluble resin of component (A) is a resin having in its molecule an acidic group such as a polymerizable unsaturated double bond that contributes to a photocuring reaction and a carboxyl group that contributes to alkali developability. It can be used without limitation. Among them, a first example preferably used is an epoxy compound having two glycidyl ether groups derived from bisphenols, preferably an epoxy compound represented by the general formula (I), (meth) Hydroxyl group-containing compound (c) containing a polymerizable unsaturated group obtained by reacting acrylic acid (which means “acrylic acid and / or methacrylic acid”), (a) tetracarboxylic acid or It is an alkali-soluble resin having a carboxyl group and a polymerizable unsaturated group in one molecule obtained by reacting the acid dianhydride and (b) a dicarboxylic acid or tricarboxylic acid or an acid anhydride thereof. Since the component (A) has both a polymerizable unsaturated double bond and a carboxyl group, it provides excellent photocurability, good developability, and patterning characteristics to the photosensitive resin composition, and improves the physical properties of the light-shielding film.

However, in general formula (I), R < ₁ >, R < ₂ >, R < ₃ > and R < ₄ > show a hydrogen atom, a C1-C5 alkyl group, a halogen atom, or a phenyl group, and X is -CO-. _{, -SO 2 -, - C (} CF 3) 2 -, - Si (CH 3) 2 -, - CH 2 -, - C (CH 3) 2 -, - O-, or, 9,9- A diyl group or a single bond is shown, and the average value of m is 0 to 10, preferably 0 to 3.

  Bisphenols that give epoxy compounds of general formula (I) include bis (4-hydroxyphenyl) ketone, bis (4-hydroxy-3,5-dimethylphenyl) ketone, bis (4-hydroxy-3,5-dichlorophenyl). ) Ketone, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxy-3,5-dimethylphenyl) sulfone, bis (4-hydroxy-3,5-dichlorophenyl) sulfone, bis (4-hydroxyphenyl) hexafluoro Propane, bis (4-hydroxy-3,5-dimethylphenyl) hexafluoropropane, bis (4-hydroxy-3,5-dichlorophenyl) hexafluoropropane, bis (4-hydroxyphenyl) dimethylsilane, bis (4-hydroxy -3,5-dimethylphenyl) dimethylsilane, bis (4-hydroxy-3,5-dichlorophenyl) dimethylsilane, bis (4- Loxyphenyl) methane, bis (4-hydroxy-3,5-dichlorophenyl) methane, bis (4-hydroxy-3,5-dibromophenyl) methane, 2,2-bis (4-hydroxyphenyl) propane, 2,2 -Bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) propane 2,2-bis (4-hydroxy-3-chlorophenyl) propane, bis (4-hydroxyphenyl) ether, bis (4-hydroxy-3,5-dimethylphenyl) ether, bis (4-hydroxy-3,5 -Dichlorophenyl) ether, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis (4-hydroxy-3-chlorophenyl) fluorene 9, 9-bis (4-hydroxy-3-bromophene) Fluorene, 9,9-bis (4-hydroxy-3-fluorophenyl) fluorene, 9,9-bis (4-hydroxy-3-methoxyphenyl) fluorene, 9,9-bis (4-hydroxy-3, 5-Dimethylphenyl) fluorene, 9,9-bis (4-hydroxy-3,5-dichlorophenyl) fluorene, 9,9-bis (4-hydroxy-3,5-dibromophenyl) fluorene, 4,4'-biphenol 3,3′-biphenol and the like. These bisphenols may use only one type of compound, or may be used in combination. Among these, bisphenols in which X in the general formula (I) is a fluorene-9,9-diyl group can be particularly preferably used.

  The compound of the general formula (I) for derivatizing into the alkali-soluble resin (A) is an epoxy compound having two glycidyl ether groups obtained by reacting the bisphenols with epichlorohydrin. The reaction generally involves oligomerization of the diglycidyl ether compound, and m is an integer of 0 to 10 for each molecule, and since a plurality of molecules are usually mixed, an average value of 0 to 10 ( The average value of m is preferably 0-3. When the average value of m exceeds the upper limit value, the viscosity of the composition becomes too high when the photosensitive resin composition using an alkali-soluble resin synthesized using the epoxy compound is used, and coating may not be performed successfully. In addition, sufficient alkali solubility cannot be imparted, and alkali developability becomes very poor.

  Next, the hydroxyl group-containing compound (c) containing a polymerizable unsaturated group obtained by the reaction between the epoxy compound and (meth) acrylic acid is reacted with the acid component, so that a carboxyl group and An alkali-soluble resin having a polymerizable unsaturated group can be obtained. As the acid component, it is preferable to use a tetracarboxylic acid or acid dianhydride (a) thereof capable of reacting with a hydroxyl group-containing compound, and a dicarboxylic acid or tricarboxylic acid or acid monoanhydride (b) thereof. The carboxylic acid residue of this acid component may have either a saturated hydrocarbon or an unsaturated hydrocarbon. These carboxylic acid residues may contain a bond containing a hetero element such as —O—, —S—, or a carbonyl group.

  Although the specific example of an acid component is shown below, the dianhydride and monoanhydride of the polyvalent carboxylic acid illustrated can also be used.

  First, examples of (a) tetracarboxylic acid include chain hydrocarbon tetracarboxylic acid, alicyclic tetracarboxylic acid, and aromatic polycarboxylic acid. Here, examples of the chain hydrocarbon tetracarboxylic acid include butanetetracarboxylic acid, pentanetetracarboxylic acid, hexanetetracarboxylic acid, and the like, and tetracarboxylic acid into which an arbitrary substituent is introduced may be used. Examples of the alicyclic tetracarboxylic acid include cyclobutanetetracarboxylic acid, cyclopentanetetracarboxylic acid, cyclohexanetetracarboxylic acid, cycloheptanetetracarboxylic acid, norbornanetetracarboxylic acid, and any substituent. The tetracarboxylic acid introduced may be used. Furthermore, examples of the aromatic tetracarboxylic acid include pyromellitic acid, benzophenone tetracarboxylic acid, biphenyl tetracarboxylic acid, and biphenyl ether tetracarboxylic acid, and even tetracarboxylic acids having an arbitrary substituent introduced therein. Good. These (a) tetracarboxylic acids may use only one type of compound, and may use them in combination.

  As (b) dicarboxylic acid or tricarboxylic acid, chain hydrocarbon dicarboxylic acid or tricarboxylic acid, alicyclic dicarboxylic acid or tricarboxylic acid, aromatic dicarboxylic acid or tricarboxylic acid is used. Here, as the chain hydrocarbon dicarboxylic acid or tricarboxylic acid, for example, succinic acid, acetyl succinic acid, maleic acid, adipic acid, itaconic acid, azelaic acid, citramalic acid, malonic acid, glutaric acid, citric acid, tartaric acid, There are oxoglutaric acid, pimelic acid, sebacic acid, suberic acid, diglycolic acid and the like, and further, dicarboxylic acid or tricarboxylic acid into which an arbitrary substituent is introduced may be used. In addition, examples of the alicyclic dicarboxylic acid or tricarboxylic acid include cyclobutane dicarboxylic acid, cyclopentane dicarboxylic acid, hexahydrophthalic acid, tetrahydrophthalic acid, norbornane dicarboxylic acid, and an arbitrary substituent group. Dicarboxylic acid or tricarboxylic acid may be used. Furthermore, examples of the aromatic dicarboxylic acid or tricarboxylic acid include phthalic acid, isophthalic acid, trimellitic acid, and the like, and further, dicarboxylic acid or tricarboxylic acid into which an arbitrary substituent is introduced may be used. These (b) dicarboxylic acids or tricarboxylic acids may be used alone or in combination.

  The molar ratio (b) / (a) of (a) tetracarboxylic acid or its acid dianhydride and (b) dicarboxylic acid or tricarboxylic acid or its acid anhydride used for the alkali-soluble resin of (A) is: It is 0.01 to 0.5, preferably 0.02 or more and less than 0.1. When the molar ratio (b) / (a) deviates from the above range, the optimum molecular weight for obtaining a photosensitive resin composition having high light-shielding and high resistance and good photopatterning property of the present invention cannot be obtained. Therefore, it is not preferable. In addition, there exists a tendency for alkali solubility to become large and molecular weight to become large, so that molar ratio (b) / (a) is small.

  Regarding the ratio of reacting the hydroxyl group-containing compound (c) containing the polymerizable unsaturated group and the acid components (b) and (a), preferably, each of the compounds is such that the end of the compound is a carboxyl group. It is desirable to cause the components to react quantitatively so that the molar ratio of the components is (c) :( b) :( a) = 1: 0.2 to 1.0: 0.01 to 1.0. In this case, the molar ratio of the total amount of the acid component to the hydroxyl group-containing compound (c) containing a polymerizable unsaturated group (c) / [(b) / 2 + (a)] = 0.5 to 1.0. It is desirable to make it react quantitatively. When this molar ratio is less than 0.5, the end of the alkali-soluble resin becomes an acid anhydride, and the content of unreacted acid dianhydride increases, and there is a concern that the stability over time of the alkali-soluble resin composition may decrease. Is done. On the other hand, when the molar ratio exceeds 1.0, the content of the hydroxyl group-containing compound containing an unreacted polymerizable unsaturated group is increased, and there is a concern that the temporal stability of the alkali-soluble resin composition may be lowered. The molar ratio of each component of (a), (b) and (c) can be arbitrarily changed within the above range for the purpose of adjusting the acid value and molecular weight of the alkali-soluble resin.

  The alkali-soluble resin (A) can be produced by a known method, for example, a method described in JP-A-8-278629, JP-A-2008-9401, or the like, according to the above-described procedure. First, as a method of reacting the epoxy compound of the general formula (I) with (meth) acrylic acid, for example, an epoxy group of the epoxy compound and equimolar (meth) acrylic acid are added to a solvent, and a catalyst (triethylbenzyl) is added. In the presence of ammonium chloride, 2,6-diisobutylphenol, etc., there is a method of reacting by heating and stirring at 90 to 120 ° C. while blowing air. Next, as a method of reacting an acid anhydride with a hydroxyl group of an epoxy acrylate compound as a reaction product, a predetermined amount of an epoxy acrylate compound, an acid dianhydride, and an acid monoanhydride is added to a solvent, and a catalyst (odor In the presence of tetraethylammonium bromide, triphenylphosphine, etc.), the reaction is carried out by heating and stirring at 90 to 140 ° C.

  The alkali-soluble resin (A) thus produced has a structure represented by the general formula (II), for example.

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

  The compound group represented by the general formula (II) is an epoxy acrylate adduct using a bisphenol type epoxy compound as a raw material, but instead of the bisphenol type epoxy compound, a novolak type epoxy compound, an epoxidized product of a phenol aralkyl compound, and a naphthol aralkyl. Epoxidized compounds and epoxidized biphenol aralkyl compounds can also be used as raw materials. In addition, when an acid component is added to an epoxy acrylate compound, an unsaturated compound obtained by coexisting a polyol compound having two or more alcoholic hydroxyl groups or a compound having two or more isocyanate groups. It is also possible to design a cured product having desired physical properties when the group-containing alkali-soluble resin is cured.

As a second example of the unsaturated group-containing alkali-soluble resin as the component (A), an alkali-soluble resin obtained by radical polymerization of (meth) acrylic acid and various (meth) acrylic acid esters, A polymerizable unsaturated group-containing alkali-soluble resin obtained by reacting methacrylic acid glycidyl can be exemplified.
Examples of the (meth) acrylic acid ester copolymerized with the (meth) acrylic acid include (meth) acrylic acid ester, (meth) acrylic acid amide, styrene and its derivatives, maleic anhydride and its derivatives, vinyl ether. And olefins.

(Meth) acrylic acid ester or amide is a group of compounds having a structure obtained by reacting (meth) acrylic acid with an alcohol (R ₆ OH) component or an amine (R ₇ R ₈ NH). Can be used without any particular restrictions. Specific examples of R ₆ , R ₇ and R ₈ include methyl group, ethyl group, propyl group, isopropyl group, butyl group, tert-butyl group, pentyl group, neopentyl group, 2-cyclopentylethyl group, cyclohexylmethyl. Monovalent alkyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, 4-methylcyclohexyl group, adamantyl group, isobornyl group, dicyclopentanyl which may be substituted with a linear, branched or alicyclic structure such as a group Group, monovalent alicyclic hydrocarbon group such as dicyclopentenyl group, monovalent aromatic hydrocarbon such as phenyl group, tolyl group, mesityl group, naphthyl group, anthryl group, benzyl group, 2-phenylethyl group Group, pyridyl group, piperidyl group, piperidino group, pyrrolyl group, pyrrolidinyl group, imidazolyl group, imidazolidini And a saturated or unsaturated monovalent heterocyclic group such as a sulfur group, a furyl group, a tetrahydrofuryl group, a thienyl group, a tetrahydrothienyl group, a morpholinyl group, a morpholino group, and a quinolyl group. Furthermore, at any position such as the above hydrocarbon group and heterocyclic group, a halogen atom, a hydroxy group, a sulfanyl group, a carbonyl group, a thiocarbonyl group, a carboxy group, a thiocarboxy group, a dithiocarboxy group, a formyl group, a cyano group , Nitro group, nitroso group, sulfo group, amino group, imino group, silyl group, ether group, thioether group, ester group, thioester group, dithioester group, amide group, thioamide group, urethane group, thiourethane group, ureido group Moreover, the structure which introduce | transduced the thioureido group etc. as a substituent can also be mentioned.

  The weight average molecular weight (Mw) in terms of polystyrene as measured by gel permeation chromatography (GPC) of the alkali-soluble resin (A) is usually 1000 to 50000, and preferably 2000 to 15000. If the weight average molecular weight is less than 1000, the adhesion of the pattern at the time of alkali development may be reduced. If the weight average molecular weight exceeds 50000, the developability may be reduced or desired when cured by light or heat. There is a risk that it may be difficult to obtain a composition having hardness. In addition, the preferable weight average molecular weight in the case of alkali-soluble resin of general formula (II) is 2000-10000, More preferably, it is 3000-7000.

  Moreover, the preferable range of the acid value of (A) alkali-soluble resin is 30-200 mgKOH / g. If this value is less than 30 mgKOH / g, residues are likely to remain during alkali development, and if it exceeds 200 mgKOH / g, the alkali developer will permeate too quickly and release development will occur. In addition, the polymerizable unsaturated group-containing alkali-soluble resin (A) can be used alone or in a mixture of two or more.

  In the present invention, the weight average molecular weight of the component (A) is a value obtained by dissolving the sampled solution in tetrahydrofuran, measuring the molecular weight distribution with HLC-8220 GPC manufactured by Tosoh Corporation, and calculating the weight average molecular weight in terms of standard polystyrene. The acid value of component (A) is a value obtained by dissolving the sampled solution in dioxane, neutralizing with a 0.1 N aqueous potassium hydroxide solution, and calculating the acid value in terms of solid content of the sample solution from the equivalence point. Is used.

  Next, (B) as the photopolymerizable monomer having at least three ethylenically unsaturated bonds, for example, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaerythritol tri (meth) Acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, sorbitol penta (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, sorbitol hexa (meth) acrylate (Meth) acrylic acid esters such as phosphazene alkylene oxide modified hexa (meth) acrylate and caprolactone modified dipentaerythritol hexa (meth) acrylate Ethers, polyhydric alcohols (pentaerythritol, dipentaerythritol, etc.) vinylbenzyl ether compounds and polyhydric phenols (phenol novolac), can be mentioned an addition polymer such as a divinyl compound such as divinylbenzene. These (B) photopolymerizable monomers having at least three ethylenically unsaturated bonds may use only one type of compound, or may be used in combination. Note that (B) the photopolymerizable monomer having at least three ethylenically unsaturated bonds does not have a free carboxy group.

  The blending ratio of the component (B) is preferably 5 to 400 parts by mass, and preferably 10 to 150 parts by mass with respect to 100 parts by mass of the component (A). When the blending ratio of the component (B) is more than 400 parts by mass with respect to 100 parts by mass of the component (A), the cured product after photocuring becomes brittle, and the acid value of the coating film is low in the unexposed area. There arises a problem that the solubility in an alkaline developer is lowered and the pattern edge is not jagged and sharp. On the other hand, when the blending ratio of the component (B) is less than 5 parts by mass with respect to 100 parts by mass of the component (A), the ratio of the photoreactive functional group in the resin is small and the formation of the crosslinked structure is not sufficient. In addition, since the acid value in the resin component is high, the solubility in the alkaline developer in the exposed area is increased, and thus the problem is that the formed pattern becomes thinner than the target line width or the pattern is easily lost. May occur.

  Examples of the photopolymerization initiator of component (C) include acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, p-tert-butyl. Acetophenones such as acetophenone, benzophenone, 2-chlorobenzophenone, benzophenones such as p, p'-bisdimethylaminobenzophenone, benzoin ethers such as benzyl, benzoin, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2- (o-chlorophenyl) -4,5-phenylbiimidazole, 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl) biimidazole, 2- (o-fluorophenyl) -4,5-diphenyl Biimidazole, 2- (o-methoxyphenyl) -4,5-diphenylbi Biimidazole compounds such as imidazole, 2,4,5-triarylbiimidazole, 2-trichloromethyl-5-styryl-1,3,4-oxadiazole, 2-trichloromethyl-5- (p-cyano Halomethyldiazole compounds such as styryl) -1,3,4-oxadiazole, 2-trichloromethyl-5- (p-methoxystyryl) -1,3,4-oxadiazole, 2,4,6 -Tris (trichloromethyl) -1,3,5-triazine, 2-methyl-4,6-bis (trichloromethyl) -1,3,5-triazine, 2-phenyl-4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-chlorophenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-methoxyphenyl) -4,6-bis ( Trichloromethyl) -1,3,5-triazine, 2- (4-methoxynaphthyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-methoxystyryl) -4, 6-bis (trichlorome ) -1,3,5-triazine, 2- (3,4,5-trimethoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-methylthiostyryl) ) -4,6-bis (trichloromethyl) -1,3,5-triazine and other halomethyl-s-triazine compounds, 1,2-octanedione, 1- [4- (phenylthio) phenyl]-, 2 -(O-benzoyloxime), 1- (4-phenylsulfanylphenyl) butane-1,2-dione-2-oxime-O-benzoate, 1- (4-methylsulfanylphenyl) butane-1,2-dione -2-oxime-O-acetate, 1- (4-methylsulfanylphenyl) butan-1-one oxime-O-acetate, ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole- 3-yl]-, 1- (0-acetyloxime), methanone, (9-ethyl-6-nitro-9H-carbazol-3-yl) [4- (2-methoxy-1-methylethoxy) -2- Mechi Ruphenyl]-, O-acetyloxime, methanone, (2-methylphenyl) (7-nitro-9,9-dipropyl-9H-fluoren-2-yl)-, acetyloxime, ethanone, 1- [7- (2 -Methylbenzoyl) -9,9-dipropyl-9H-fluoren-2-yl]-, 1- (O-acetyloxime), ethanone, 1-(-9,9-dibutyl-7-nitro-9H-fluorene- O-acyloxime compounds such as 2-yl)-, 1-O-acetyloxime, benzyldimethyl ketal, thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2-methylthioxanthone, Sulfur compounds such as 2-isopropylthioxanthone, anthraquinones such as 2-ethylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-diphenylanthraquinone, azobisisobutylnitrile, benzoyl peroxide De, organic peroxides such as cumene peroxide, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, and 2-mercaptobenzothiazole thiol compounds are exemplified. Among these, from the viewpoint of easily obtaining a photosensitive resin composition for a light-sensitive light-shielding film, it is preferable to use O-acyloxime compounds. These (C) photopolymerization initiators may use only one type of compound, or may be used in combination. In addition, the photoinitiator as used in the field of this invention is used by the meaning containing a sensitizer.

  These photopolymerization initiators and sensitizers can be used alone or in combination of two or more. Moreover, although it does not act as a photopolymerization initiator or a sensitizer by itself, a compound capable of increasing the ability of the photopolymerization initiator or the sensitizer can be added by using in combination. Examples of such compounds include tertiary amines such as triethanolamine and triethylamine which are effective when used in combination with benzophenone.

  (C) The usage-amount of the photoinitiator of a component should be 0.1-40 mass parts on the basis of a total of 100 mass parts of (A) component and (B) component, Preferably it is 1-25 mass. Good part. When the blending ratio of the component (C) is less than 0.1 parts by mass, the rate of photopolymerization is slowed and the sensitivity is lowered. On the other hand, when it exceeds 40 parts by mass, the sensitivity is too strong, The pattern line width becomes thicker than the pattern mask, and there is a possibility that a line width that is faithful to the mask cannot be reproduced, or the pattern edge does not become jagged and sharp.

The component (D) has a film thickness of 10 to 1.5 μm from a composition containing 5 to 20% by mass of the (D) component and 5 to 15% by mass of the (A) component in the (E) component. The light-shielding component containing insulating carbon black has a surface resistivity of 1 × 10 ⁸ Ω / □ or more. The insulating carbon black that can be contained in such a light shielding component needs to be subjected to an insulating treatment on the surface of the carbon black by various methods, but the method of the insulating treatment is not particularly limited. Examples of the insulating treatment method include a method of coating with a resin (for example, JP-A-9-95625), a method of oxidizing with an oxidizing agent (for example, JP-A-11-181326), and a polymer compound having a reactive group. (For example, JP-A-9-265006), a method for chemically modifying with an organic group (for example, JP-T-2008-517330), a method for using a graft reaction and coating with a resin together (for example, JP-A-2002-51730). No. 249678), a method of coating with a dye (for example, International Publication No. 2013/129555), and the like are known.

  As the component (D), two or more kinds of insulating carbon black can be used, black organic pigments such as perylene black, aniline black, cyanine black, lactam black, red, blue, green, purple, yellow, cyanine Organic pigments such as magenta can also be used in combination. The selection of the light-shielding component containing carbon black as an essential component is necessary in consideration of insulation, heat resistance, light resistance, solvent resistance, etc. In some cases, black may be achromatic. A combination of light shielding components can be selected as possible.

  Examples of the solvent for component (E) include methanol, ethanol, n-propanol, isopropanol, ethylene glycol, propylene glycol, 3-methoxy-1-butanol, ethylene glycol monobutyl ether, 3-hydroxy-2-butanone, Alcohols such as diacetone alcohol, terpenes such as α- or β-terpineol, etc., ketones such as acetone, methyl ethyl ketone, cyclohexanone, N-methyl-2-pyrrolidone, aromatic carbonization such as toluene, xylene, tetramethylbenzene Hydrogen, cellosolve, methyl cellosolve, ethyl cellosolve, carbitol, methyl carbitol, ethyl carbitol, butyl carbitol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene group Glycol ethers such as coal monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, ethyl acetate, butyl acetate, ethyl lactate, 3-methoxybutyl acetate, 3-methoxy-3- Examples include methyl butyl acetate, cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, carbitol acetate, ethyl carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and the like. A uniform solution-like composition can be obtained by dissolving and mixing the composition. Two or more kinds of these solvents may be used in order to obtain necessary characteristics such as coatability.

  The light-shielding component containing these insulating carbon blacks as essential components is preferably pre-dispersed in a solvent together with the (F) dispersant to obtain a carbon black dispersion, and then a photosensitive resin composition for a light-shielding film. It is better to mix as Here, since the solvent to be dispersed becomes a part of the component (E), any of those listed above as the component (E) can be used. For example, propylene glycol monomethyl ether acetate, 3-methoxybutyl Acetate or the like is preferably used. About the compounding ratio of the insulating carbon black of (D) which forms a carbon black dispersion liquid, it is used in 5-60 mass% with respect to the total solid of the photosensitive resin composition for light shielding films of this invention. It is good. In addition, the said solid content means a component except (E) component among compositions. The solid content includes a component (B) that becomes a solid content after photocuring. If it is less than 5% by mass, the desired light-shielding property cannot be set. If it exceeds 60% by mass, the content of the photosensitive resin, which is the original binder, decreases, so that undesired problems occur in that the development characteristics are impaired and the film forming ability is impaired.

  The average particle diameter (hereinafter referred to as “average secondary particle diameter”) of the light-shielding component in the light-shielding dispersion measured with a laser diffraction / scattering particle size distribution meter is preferably as follows. For the insulating carbon black and the organic pigment used in combination, the average secondary particle size of the dispersed particles is preferably 20 to 500 nm. In addition, also in the photosensitive resin composition for light shielding films prepared by blending these carbon black dispersions, these light shielding components preferably have the same average secondary particle size.

  As the dispersant (F), known dispersants such as various polymer dispersants can be used. As examples of the dispersant, known compounds conventionally used for pigment dispersion (compounds marketed under the names of dispersants, dispersion wetting agents, dispersion accelerators, etc.) can be used without particular limitation. Examples thereof include cationic polymer dispersants, anionic polymer dispersants, nonionic polymer dispersants, pigment derivative dispersants (dispersion aids), and the like. In particular, it has a cationic functional group such as an imidazolyl group, pyrrolyl group, pyridyl group, primary, secondary or tertiary amino group as an adsorption point to the pigment, an amine value of 1 to 100 mgKOH / g, and a number average molecular weight Is preferably a cationic polymer dispersant having a molecular weight of 1,000 to 100,000. The blending amount of the dispersant is 1 to 30% by mass, preferably 2 to 25% by mass, based on the light shielding component containing insulating carbon black as an essential component.

  Furthermore, when preparing a carbon black dispersion, a part of the polymerizable unsaturated group-containing alkali-soluble resin (A) component is co-dispersed in addition to the dispersant, thereby forming a photosensitive resin composition for a light-shielding film. When the product is made into a product, the exposure sensitivity can be easily maintained at a high sensitivity, and a photosensitive resin composition having good adhesion during development and hardly causing a problem of residue can be obtained. The amount of component (A) is preferably 2 to 20% by mass in the carbon black dispersion, and more preferably 5 to 15% by mass. When the component (A) is less than 2% by mass, it is not possible to obtain co-dispersed effects such as improved sensitivity, improved adhesion, and reduced residue. Further, when the content is 20% by mass or more, the viscosity of the carbon black dispersion is high, particularly when the content of the light shielding component containing the insulating carbon black as an essential component is large, and it is difficult or very difficult to disperse uniformly. Therefore, it is difficult to obtain a photosensitive resin composition for obtaining a coating film in which insulating carbon black is uniformly dispersed.

  The carbon black dispersion thus obtained is composed of the component (A) (the remaining component (A) when the component (A) is co-dispersed when the carbon black dispersion is prepared), (B) It can be set as the photosensitive resin composition for light shielding films by mixing with a component, (C) component, and the remaining (E) component.

  In addition, the photosensitive resin composition of the present invention includes a curing accelerator, a thermal polymerization inhibitor and an antioxidant, a plasticizer, a filler, a leveling agent, an antifoaming agent, a coupling agent, and a surfactant as necessary. Etc. can be mix | blended. Examples of thermal polymerization inhibitors and antioxidants include hydroquinone, hydroquinone monomethyl ether, pyrogallol, tert-butylcatechol, phenothiazine, hindered phenol compounds, and the like, and plasticizers include dibutyl phthalate, dioctyl phthalate, phosphorus Examples of the filler include glass fiber, silica, mica, and alumina. Examples of the leveling agent and antifoaming agent include silicone, fluorine, and acrylic compounds. be able to. As coupling agents, silane coupling agents such as 3- (glycidyloxy) propyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, and 3-ureidopropyltriethoxysilane are used. Examples of the surfactant include a fluorine-based surfactant and a silicone-based surfactant.

  The photosensitive resin composition of the present invention may be used in combination with other resin components that are polymerized or cured by heat. As other resin components, (G) an epoxy resin or an epoxy compound having two or more epoxy groups is preferable, and 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol type epoxy resin, bisphenol Type A epoxy resin, bisphenolfluorene type epoxy resin, phenol novolac type epoxy resin, 3,4-epoxycyclohexenylmethyl-3 ', 4'-epoxycyclohexenecarboxylate, 2,2-bis (hydroxymethyl) -1-butanol 1,2-epoxy-4- (2-oxiranyl) cyclohexane adduct, epoxy silicone resin and the like. As these additional components, only one kind of compound may be used, or a plurality thereof may be used in combination.

  The photosensitive resin composition of this invention contains the said (A)-(E) component as a main component. In the solid content, the components (A) to (D) are 70% by mass in total, preferably 80% by mass or more. (E) Although the quantity of a solvent changes with target viscosity, it is good to make it contain in the range of 60-90 mass% in the photosensitive resin composition. When the component (G) is used in combination, the ratio of (G) / {(A) + (B) + (G)} is preferably 5 to 30% by mass, and preferably 10 to 20% by mass. More preferred.

  The photosensitive resin composition of the present invention is characterized in that the hardness of the cured film of the composition excluding insulating carbon black (component (D)), which is a light shielding component, is at a certain level or higher. The film forming conditions of the cured film for measuring the hardness are photocuring conditions and heat curing conditions used when a desired pattern is obtained using the photosensitive resin composition of the present invention. For example, the composition for hardness measurement comprising the components (A) to (C) and (E) is spin-coated on a glass substrate with a spinner machine, and heated and dried at a temperature of 60 to 110 ° C. for 1 to 3 minutes. Using an exposure apparatus equipped with a high-pressure mercury lamp, a predetermined amount of exposure is performed without using a photomask, and further, thermosetting is performed at 180 to 250 ° C. for 20 to 60 minutes, thereby producing a hardness measurement cured film. When the pencil hardness of the cured film is measured, a cured film having a pencil hardness of HB or higher is preferably obtained. More preferably, the components (A) to (C), and further (G) an epoxy resin or an additive such as an epoxy compound or a curing accelerator are appropriately composed so that the pencil hardness is H or higher, and the photosensitive resin of the present invention. A composition is preferred. When the pencil hardness is softer than HB, there is a possibility that inconveniences such as insufficient recovery of elasticity in mechanical properties as a spacer may occur. In particular, when the content of a light-shielding component such as carbon black is small, the effect may be significant.

  The method for obtaining a cured film having a pencil hardness of HB or higher is not particularly limited. For example, the component (A) and the component (B) can be selected in consideration of the following points.

  In order to increase the hardness of the cured film, crosslinking between molecules of the polymerizable unsaturated group-containing alkali-soluble resin (component (A)) formed during photocuring and the component (A) and the polymerizable monomer ((B)) It is necessary to design the selection of the component (A), the selection of the component (B), and the blending ratio so that the cross-linking between the components) becomes a certain amount or more. When the molecular weight of the component (A) increases and the content of the polymerizable unsaturated group in one molecule decreases, it becomes difficult to increase the amount of crosslinking. When the molecular weight of the component (A) is too large, the amount of crosslinks between the components (A) and between the components (A) and (B) is increased even if the content of the polymerizable unsaturated group in one molecule is large. It is also necessary to consider that things tend to be difficult. Moreover, it is difficult to increase the amount of crosslinking unless the polymerizable unsaturated group of the component (B) is 3 or more. In addition, the physical properties of the cured product are also affected by the structure of the alkali-soluble resin and the structure of the polymerizable monomer. Therefore, the components (A) and (B) to be combined are selected in consideration of these points, and the blending ratio is designed. Will do.

  The photosensitive resin composition for a light shielding film in the present invention is excellent as a photosensitive resin composition for forming a light shielding film having a spacer function, for example. As a method for forming a light shielding film having a spacer function, the following photolithography methods are available. First, a photosensitive resin composition for a light-shielding film in the present invention is applied onto a substrate, and then the solvent is dried (prebaked), and then a photomask is applied on the coating thus obtained, and ultraviolet rays are applied. May be used to cure the exposed area, further develop an elution of the unexposed area using an alkaline aqueous solution to form a pattern, and perform post-baking (thermal baking) as post-drying.

  The substrate may be a transparent substrate, or a transparent substrate such as an alignment film formed on a pixel, a planarizing film on the pixel, or a planar film on the pixel after forming a pixel such as RGB. Other base materials may be used. The substrate on which the light-shielding film having the spacer function is formed varies depending on the design of the liquid crystal display device.

  As a transparent substrate to which the photosensitive resin composition is applied, in addition to a glass substrate, a transparent film (for example, polycarbonate, polyethylene terephthalate, polyether sulfone, etc.) is deposited or patterned with a transparent electrode such as ITO or gold. Can be illustrated. As a method of applying the solution of the photosensitive resin composition on the transparent substrate, in addition to a known solution dipping method and spray method, any method such as a roller coater machine, a land coater machine, a slit coater machine, or a spinner machine can be used. Methods can also be employed. After applying to a desired thickness by these methods, the film is formed by removing the solvent (pre-baking). Pre-baking is performed by heating with an oven, a hot plate or the like. The heating temperature and heating time in the pre-baking are appropriately selected according to the solvent to be used, and are performed at a temperature of 60 to 110 ° C. for 1 to 3 minutes, for example.

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

  The alkali development after the exposure is performed for the purpose of removing the resist in the unexposed portion, and a desired pattern is formed by this development. Examples of the developer suitable for the alkali development include, for example, an aqueous solution of an alkali metal or alkaline earth metal carbonate, an aqueous solution of an alkali metal hydroxide, and the like. Particularly, sodium carbonate, potassium carbonate, lithium carbonate, and the like. It is better to develop at a temperature of 23 to 28 ° C. using a weakly alkaline aqueous solution containing 0.05 to 3% by mass of carbonate such as a commercially available developing machine or ultrasonic cleaner. It can be formed precisely.

  After the development, heat treatment (post-bake) is preferably performed at a temperature of 180 to 250 ° C. and a condition of 20 to 60 minutes. This post-baking is performed for the purpose of improving the adhesion between the patterned light-shielding film and the substrate. This is performed by heating with an oven, a hot plate or the like, as in the pre-baking. The patterned light-shielding film of the present invention is formed through each step by the above photolithography method.

According to the above method, a light-shielding film having an optical density OD of 0.5 / μm to 4 / μm, preferably 1.5 / μm to 2.5 / μm can be formed. Further, according to the above method, it is possible to form a light-shielding film having a volume resistivity of 1 × 10 ⁹ Ω · cm or more, preferably 1 × 10 ¹² Ω · cm or more when a voltage of 10 V is applied. Further, according to the above method, a light shielding film having a dielectric constant of 2 to 10, preferably 2 to 8 can be formed. Further, according to the above method, in the mechanical property test, it is possible to form a light-shielding film satisfying a fracture strength of 200 mN or more, an elastic recovery rate of 30% or more, and / or a compression rate of 40% or less. . The light-shielding film formed by the above method can be used as a column spacer of a liquid crystal display device, and can be preferably used as a black column spacer.

  Further, according to the above method, H2 is 1 to 2 for the film thickness H1 for setting the optical density as the light-shielding film to 0.5 / μm or more and 4 / μm or less and the film thickness H2 of the light-shielding film serving as a spacer function. When the thickness is 7 μm, a light-shielding film with a film thickness H1 and a light-shielding film with a film thickness H2 with ΔH = H2−H1 of 0.1 to 6.9 can be formed simultaneously. A more preferable range is an optical density of 0.5 / μm to 3 / μm as a light shielding film, H2 is 2 to 5 μm, and ΔH is 0.1 to 2.9. As a more preferable range, the optical density as a light-shielding film is 0.5 / μm to 2 / μm, H2 is 2 to 4 μm, and ΔH is 1.0 to 2.0. The cured film formed by the above method can be used as a column spacer of a liquid crystal display device, and can be preferably used as a black column spacer. According to the cured film having the above ΔH in the above range, the black column spacers having different heights can be formed from the same material at the same time, so that the liquid crystal display device can be manufactured more efficiently. At this time, for example, the cured film having the thickness H2 can function as a spacer, and the cured film having the thickness H1 can function as a black matrix. The spacer height H2 and the light-shielding film thickness H1 are determined appropriately by the design of the two substrates sandwiching the liquid crystal layer, and the appropriate H1 corresponding to the value of H2, that is, ΔH The range is to be determined.

  The liquid crystal display device having the light shielding film or the cured film is preferably a TFT-LCD provided with a thin film transistor.

  The liquid crystal display device having the light-shielding film or the cured film has high light-shielding properties and insulating properties, and further has a spacer function excellent in elastic modulus, deformation amount, and elastic recovery rate, and has a film thickness of about 1 to 7 μm. Even so, a fine spacer shape can be formed.

  Hereinafter, although an embodiment of the present invention is described concretely based on an example and a comparative example, the present invention is not limited to these.

  First, a synthesis example of the (A) polymerizable unsaturated group-containing alkali-soluble resin of the present invention is shown. Evaluation of the resin in the synthesis example was performed as follows.

[Solid content]
1 g of the resin solution obtained in the synthesis example was impregnated into a glass filter [weight: W0 (g)] and weighed [W1 (g)], and the weight after heating at 160 ° C. for 2 hours [W2 (g)] From the following equation.
Solid content concentration (% by weight) = 100 × (W2−W0) / (W1−W0).

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

[Molecular weight]
Gel permeation chromatography (GPC) [trade name HLC-8220 GPC manufactured by Tosoh Corporation, solvent: tetrahydrofuran, column: TSKgelSuperH-2000 (2) + TSKgelSuperH-3000 (1) + TSKgelSuperH-4000 (1) + TSKgelSuper-H5000 (One) [made by Tosoh Corporation], temperature: 40 ° C., speed: 0.6 ml / min], and weight average molecular weight (Mw) as a converted value of standard polystyrene [PS-oligomer kit made by Tosoh Corporation] Asked.

Abbreviations used in the synthesis examples and comparative synthesis examples are as follows.
BPFE: a reaction product of 9,9-bis (4-hydroxyphenyl) fluorene and chloromethyloxirane. In the compound of the general formula (I), a compound in which X is fluorene-9,9-diyl, R ₁ and R ₂ are hydrogen.
BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride BTDA: 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride THPA: 1,2,3,6-tetrahydrophthal Acid anhydride TPP: Triphenylphosphine PGMEA: Propylene glycol monomethyl ether acetate

[Synthesis Example 1]
BPFE 116.7 g (0.23 mol), acrylic acid 33.1 g (0.46 mol), TPP 0.60 g, and PGMEA 161.0 were charged into a 1 L four-necked flask equipped with a reflux condenser. The reaction product was obtained by stirring for 12 hours under heating.

  Next, 33.8 g (0.12 mol) of BPDA and 17.5 g (0.12 mol) of THPA were added to the obtained reaction product, stirred for 6 hours under heating at 115 to 120 ° C., and an alkali-soluble resin containing a polymerizable unsaturated group. Solution (A) -1 was obtained. The obtained resin solution had a solid content concentration of 56.5 wt%, an acid value (in terms of solid content) of 102 mgKOH / g, and a Mw of 3600 by GPC analysis.

[Comparative Synthesis Example 1]
In a 1000 ml four-necked flask equipped with a nitrogen introduction tube and a reflux tube, 51.65 g (0.60 mol) of methacrylic acid, 38.44 g (0.38 mol) of methyl methacrylate, 38.77 g (0.22 mol) of benzyl methacrylate, azo Bisisobutyronitrile (5.91 g) and diethylene glycol dimethyl ether (370 g) were charged, and polymerization was carried out by stirring for 8 hours at 80 to 85 ° C. in a nitrogen stream. Further, 39.23 g (0.28 mol) of glycidyl methacrylate, 1.44 g of TPP, and 0.055 g of 2,6-di-tert-butyl-p-cresol were charged in the flask, and the mixture was stirred at 80 to 85 ° C. for 16 hours. A soluble resin solution (A) -2 was obtained. The obtained resin solution had a solid content concentration of 32% by mass, an acid value (in terms of solid content) of 110 mgKOH / g, and an Mw of 18100 by GPC analysis.

(Polymerizable unsaturated group-containing alkali-soluble resin)
(A) -1 component: alkali-soluble resin solution obtained in Synthesis Example 1 (A) -2 component: alkali-soluble resin solution obtained in Comparative Synthesis Example 1

(Photopolymerizable monomer)
(B): Mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (manufactured by Nippon Kayaku Co., Ltd., trade name DPHA)

(Photopolymerization initiator)
(C): Ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime) (manufactured by BASF Japan, product name Irgacure OXE02 )

(Carbon black dispersion)
(D) -1: PGMEA dispersion having a resin-coated carbon black concentration of 25.0% by mass and a dispersant concentration of 5.0% by mass (solid content: 30.0%)
(D) -2: PGMEA dispersion (carbon solid content 25%) of carbon black 20.0% by mass and polymer dispersant 5.0% by mass

(solvent)
(E) -1: PGMEA
(E) -2: 3-methoxy-3-methyl-1-butyl acetate

(Epoxy resin)
(G): 1,2-epoxy-4- (2-oxiranyl) cyclohexane adduct of 2,2-bis (hydroxymethyl) -1-butanol (“EHPE3150” manufactured by Daicel)

(Silane coupling agent)
(H): 3-mercaptopropyltrimethoxysilane (trade name: KBM-803: manufactured by Shin-Etsu Chemical Co., Ltd.)

(Surfactant)
(I): PGMEA solution (1.0% solid content) of BYK-330 (manufactured by Big Chemie)

[Evaluation of composition components]
<Preparation of carbon black property evaluation composition>
Resin solution (component (A) -1), carbon black dispersion (component (D) -1 or component (D) -2) and solvent (component (E) -1) are adjusted to a solid content concentration of 20%. A composition for measuring carbon black was prepared by mixing. A carbon black concentration was adjusted while measuring the optical density (OD) to prepare a composition capable of forming a cured film having an OD = 4 / μm. Table 1 shows the compositions used for measuring the surface resistivity.

<Optical density>
The composition for measuring carbon black obtained above was applied on a glass substrate having a thickness of 1.2 mm using a spin coater so that the film thickness after thermosetting treatment was 1.1 μm, and 1 at 90 ° C. Pre-baked for a minute. Thereafter, heat curing treatment was performed at 230 ° C. for 30 minutes using a hot air dryer to obtain a cured film of the composition. Next, the optical density of the obtained cured film was measured using a Macbeth transmission densitometer, and evaluated by the optical density per unit film thickness.

<Surface resistivity measurement>
The surface resistivity of the cured film whose optical density was measured was measured at a voltage of 10 V using a surface resistivity meter (Hiresta UP manufactured by Mitsubishi Chemical Analytech Co., Ltd.). The measurement results are shown in Table 1.

<Preparation of composition for evaluating characteristics of photocuring component>
Resin solution ((A) -1 component), photopolymerizable monomer ((B) component), photopolymerization initiator ((C) component), solvent ((E) -1 component), and epoxy resin ((G) The composition for property evaluation of the photocuring component shown in Table 2 was prepared using the component.

<Measurement of pencil hardness>
Each photosensitive resin composition obtained above was applied onto a glass substrate having a thickness of 1.2 mm using a spin coater so that the film thickness after the thermosetting treatment was 1.2 μm, and 1 at 90 ° C. Pre-baked for a minute. Then, ultraviolet rays of 100 mJ / cm ² were irradiated with an ultrahigh pressure mercury lamp having an illuminance of 30 mW / cm ² with a wavelength of 365 nm without performing a photomask to perform a photocuring reaction. Then, the heat curing process was performed for 30 minutes at 230 degreeC using the hot air dryer, and the cured film of the photocuring component was obtained.

  For this cured film, according to JIS-K5400 test method, the highest pencil hardness at which the coating film was not damaged when a load of 500 g was applied using a pencil hardness tester was taken as the measured value. The pencil used is "Mitsubishi High Uni".

  The evaluation as a photosensitive resin composition having a spacer function is to prepare the photosensitive resin compositions of Examples 1 to 5 and Comparative Examples 1 to 3 by blending the above-mentioned blending components in the ratio shown in Table 3. Evaluation was performed. In addition, all the numerical values in Table 3 represent parts by mass. Moreover, (E) -1 in the column of a solvent is PGMEA (same as (E) -1) in unsaturated group containing resin solution (polymerizable unsaturated group containing alkali-soluble resin solution), and carbon black dispersion It is an amount not containing PGMEA in the same (same as (E) -1).

[Evaluation of composition for light shielding film]
Using the photosensitive resin compositions for light shielding films of Examples 1 to 5 and Comparative Examples 1 to 3, the following evaluations were performed. These evaluation results are shown in Table 4.

<Development characteristics>
Each photosensitive resin composition obtained above has a thickness of 3.0 μm after heat curing using a spin coater on a 1.2 mm thick glass substrate (Examples 1, 2, 4 and Comparative Examples). 3) or 1.5 μm (Examples 3 and 5 and Comparative Examples 1 and 2) were applied and prebaked at 90 ° C. for 1 minute. Thereafter, a photomask was brought into close contact, and an ultraviolet ray of 100 mJ / cm ² was irradiated with an ultra-high pressure mercury lamp having a wavelength of 365 nm and an illuminance of 30 mW / cm ² to perform photocuring reaction of the photosensitive portion.

Next, the exposed glass substrate was developed with 0.05% aqueous potassium hydroxide solution at 24 ° C. and a pressure of 0.1 MPa for 60 seconds to remove unexposed portions of the coating film. Then, the heat curing process was performed for 30 minutes at 230 degreeC using the hot air dryer, and the cured film of the photosensitive resin composition was obtained.
Formation of fine lines of the obtained cured film pattern was confirmed with an optical microscope and evaluated in the following three stages. The results are shown in Table 4.
○: Pattern with L / S of 10 μm / 10 μm or more formed without residue Δ: Pattern with L / S of 30 μm / 30 μm or more formed without residue ×: L / S less than 50 μm / 50 μm Pattern is not formed, or the bottom of the pattern or residue is conspicuous

<Volume resistivity>
Each photosensitive resin composition obtained above has a film thickness of 3.5 μm after thermosetting using a spin coater on the portion excluding the electrode on the 1.2 mm thick glass substrate on which Cr is deposited. And then prebaked at 90 ° C. for 1 minute. Thereafter, heat curing treatment was performed at 230 ° C. for 30 minutes using a hot air dryer to obtain a cured film of the photosensitive resin composition. Thereafter, an aluminum electrode was formed on the cured film to produce a volume resistivity measurement substrate. Next, the volume resistivity at an applied voltage of 1 V to 10 V was measured using an electrometer (“6517A type” manufactured by Keithley). Measurements were performed under the condition that voltage was held for 60 seconds at each applied voltage in 1 V step, and Table 4 shows the volume resistivity when 10 V was applied.

<Dielectric constant>
Each photosensitive resin composition obtained above has a film thickness of 3.5 μm after thermosetting using a spin coater on the portion excluding the electrode on the 1.2 mm thick glass substrate on which Cr is deposited. And then prebaked at 90 ° C. for 1 minute. Thereafter, heat curing treatment was performed at 230 ° C. for 30 minutes using a hot air dryer to obtain a cured film of the photosensitive resin composition. Thereafter, an aluminum electrode was formed on the cured film to produce a dielectric constant measurement substrate. Next, using a electrometer (“6517A type” manufactured by Keithley), the electric capacity at a frequency of 1 Hz to 100,000 Hz was measured, and the dielectric constant was calculated from the electric capacity. The calculated dielectric constant is shown in Table 4.

<Halftone (HT) characteristics of spacer>
Each photosensitive resin composition obtained above has a thickness of 3.0 μm after heat curing using a spin coater on a 1.2 mm thick glass substrate (Examples 1, 2, 4 and Comparative Examples). 3) or 1.5 μm (Examples 3 and 5 and Comparative Examples 1 and 2) were applied and prebaked at 90 ° C. for 1 minute. Then, is adhered a photomask having a dot pattern, is irradiated with ultraviolet light of 5 mJ / cm ² or 100 mJ / cm ² by an ultra-high pressure mercury lamp of wavelength 365nm illumination 30 mW / cm ^2, it was subjected to photocuring reaction of the photosensitive portion .
Next, the exposed glass substrate was developed with 0.05% aqueous potassium hydroxide solution at 24 ° C. and a pressure of 0.1 MPa for 60 seconds to remove unexposed portions of the coating film. Then, the heat curing process was performed for 30 minutes at 230 degreeC using the hot air dryer, and the cured film of the photosensitive resin composition was obtained.

Halftone characteristics of the spacer, the exposure amount calculating a difference ([Delta] H) of the thickness of the spacer (H2) in 5 mJ / cm thickness of the light-shielding film in ² (H1) and 100 mJ / cm ^2, the following three steps evaluated. The results are shown in Table 4.
○: When ΔH is 1.0 μm to 2.0 μm Δ: When ΔH is 0.1 μm to 2.9 μm ×: When ΔH is less than 0.1 μm or larger than 2.9 μm

<Spacer compression rate, elastic recovery rate, fracture strength>
Each photosensitive resin composition obtained above was applied on a glass substrate having a thickness of 1.2 mm using a spin coater so that the film thickness after the thermosetting treatment was 3.0 μm, and 1 at 90 ° C. Pre-baked for a minute. Thereafter, a photomask having a dot pattern was brought into close contact, and an ultraviolet ray of 100 mJ / cm ² was irradiated with an ultra-high pressure mercury lamp having a wavelength of 365 nm and an illuminance of 30 mW / cm ² to perform photocuring reaction of the photosensitive portion.

Next, the exposed glass substrate was developed with 0.05% aqueous potassium hydroxide solution at 24 ° C. and a pressure of 0.1 MPa for 60 seconds to remove unexposed portions of the coating film. Then, the heat curing process was performed for 30 minutes at 230 degreeC using the hot air dryer, and the cured film of the photosensitive resin composition was obtained.
The spacer property of the obtained cured film pattern was evaluated using an ultra-micro hardness meter (Fischer Instruments, Fisherscope HM2000Xyp). A 100 μm square planar indenter was pushed in at a loading speed of 5.0 mN / sec, and a load of up to 50 mN was applied. Then, the unloading speed was 5.0 mN / sec, and a displacement curve was created.
The compression rate was calculated from the following equation, with the amount of displacement at a load of 50 mN at the time of load being L1.
Compression rate (%) = L1 / spacer height × 100

The elastic recovery rate was calculated from the following equation, assuming that the displacement amount at a load of 50 mN at the time of loading was L1, and the displacement amount at the time of unloading was L2.
Elastic recovery rate (%) = (L1-L2) / L1 × 100

The fracture strength was evaluated using an ultra-micro hardness meter (Fischer Instruments, Fisherscope HM2000Xyp). A 100 μm square planar indenter was pushed in at a load speed of 5.0 mN / sec, a load up to 300 mN was applied to measure the load when the spacer was broken, and the following four stages were evaluated. The results are shown in Table 4.
○: When the breaking strength is 300 mN or more Δ: When the breaking strength is 200 mN or less and less than 300 mN ×: When the breaking strength is 100 mN or less and less than 200 mN

<Spacer shape>
Each photosensitive resin composition obtained above was applied on a glass substrate having a thickness of 1.2 mm using a spin coater so that the film thickness after the thermosetting treatment was 3.0 μm, and 1 at 90 ° C. Pre-baked for a minute. Thereafter, a photomask having a dot pattern was brought into close contact, and an ultraviolet ray of 100 mJ / cm ² was irradiated with an ultra-high pressure mercury lamp having a wavelength of 365 nm and an illuminance of 30 mW / cm ² to perform photocuring reaction of the photosensitive portion.

Next, the exposed glass substrate was developed with 0.05% aqueous potassium hydroxide solution at 24 ° C. and a pressure of 0.1 MPa for 60 seconds to remove unexposed portions of the coating film. Then, the heat curing process was performed for 30 minutes at 230 degreeC using the hot air dryer, and the cured film of the photosensitive resin composition was obtained.
The shape of the spacer was evaluated by the internal angle (taper angle) of the spacer end using a scanning electron microscope. When the taper angle is 70 ° or more and 90 ° or less, ◎, when the taper angle is 50 ° or more and less than 70 °, ◯, when it is 50 ° or less, Δ, and when it is 90 ° or more, ×.

  From the results of Examples 1 to 5 and Comparative Examples 1 to 3, the volume resistivity is maintained by using (D) insulating carbon black and setting the hardness of the cured film excluding the component (D) to HB or higher. It can be seen that the spacer characteristics such as the light shielding property, the dielectric constant, and the elastic recovery rate can be improved.

Claims (12)

A photosensitive resin composition for a light-shielding film having a spacer function, comprising (A) to (E) as essential components,
(A) a polymerizable unsaturated group-containing alkali-soluble resin,
(B) a photopolymerizable monomer having at least three ethylenically unsaturated bonds,
(C) a photopolymerization initiator,
(D) a light-shielding component comprising an insulating carbon black whose surface resistivity is 1 × 10 ⁸ Ω / □ or more, and (E) a solvent;
(D) The photosensitive resin composition characterized by the pencil hardness of the hardened | cured material of the composition except a component being HB or more. (B) component is 5-400 mass parts with respect to 100 mass parts of (A) component,
(C) 0.1-40 mass parts with respect to 100 mass parts of total amounts of (A) component and (B) component,
When (B) component which becomes solid content after photocuring is included, and the component except (E) component is solid content,
(D) A component is 5-60 mass% in the total amount of solid content,
The photosensitive resin composition according to claim 1, comprising each of them. (A) The photosensitive resin composition of Claim 1 or 2 using the polymerizable unsaturated group containing alkali-soluble resin represented by general formula (II) as a component.

In the formula, R ₁ , R ₂ , R ₃ and R ₄ each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom or a phenyl group, and R ₅ represents a hydrogen atom or a methyl group. X represents —CO—, —SO ₂ —, —C (CF ₃ ) ₂ —, —Si (CH ₃ ) ₂ —, —CH ₂ —, —C (CH ₃ ) ₂ —, —O—, A fluorene-9,9-diyl group or a direct bond; Y represents a tetravalent carboxylic acid residue; Z is independently a hydrogen atom or —OC—W— (COOH) ₁ (where W is Represents a divalent or trivalent carboxylic acid residue, l represents a number of 1 to 2, and n represents a number of 1 to 20.   The photosensitive resin composition according to claim 1, further comprising (G) an epoxy resin or an epoxy compound having two or more epoxy groups. A light-shielding film having an optical density OD of 0.5 / μm or more and 4 / μm or less, and having a volume resistivity of 1 × 10 ⁹ Ω · cm or more and a dielectric constant of 2 to 10 when a voltage of 10 V is applied. The photosensitive resin composition according to claim 1, wherein a film can be formed. 6. The light-shielding film satisfying at least one of the following (i) to (iii) can be formed in a load-unloading test using a micro hardness tester, according to claim 1: Photosensitive resin composition.
(I) The compressibility is 40% or less (ii) The elastic recovery rate is 30% or more (iii) The fracture strength is 200 mN or more.   A light-shielding film having a spacer function, which is formed by curing the photosensitive resin composition according to claim 1.   A liquid crystal display device comprising the light-shielding film according to claim 7 as a black column spacer (BCS).   The liquid crystal display device according to claim 8, further comprising a thin film transistor (TFT).   In the manufacturing method of the light shielding film formed on the board | substrate which apply | coats the photosensitive resin composition of any one of Claims 1-6 to a board | substrate, and hardens the said photosensitive resin composition by light irradiation, ΔH = H2 when H2 is 1 to 7 μm with respect to the film thickness H1 for setting the optical density OD as the light shielding film to 0.5 / μm or more and 4 / μm or less and the film thickness H2 of the light shielding film serving as the spacer function. A method for producing a light-shielding film, comprising simultaneously forming a light-shielding film having a film thickness H1 and a film thickness H2 in which H1 is 0.1 to 6.9.   A method for producing a liquid crystal display device, wherein the light shielding film produced by the method according to claim 10 is used as a black column spacer.   The method according to claim 11, wherein the liquid crystal display device includes a thin film transistor (TFT).