KR102585415B1 - Photosensitive resin composition, light-shielding film thereof, and manufacturing process of lcd with that film - Google Patents

Abstract

(Problem) To provide a photosensitive resin composition that maintains light-shielding and insulating properties, has excellent spacer properties such as compression ratio, elastic recovery rate, and fracture strength, and is capable of forming a step of ΔH and obtaining a spacer having an excellent pattern shape.
(Solutions) This invention relates to a photosensitive resin composition. The photosensitive resin composition of the present invention is a photosensitive resin composition for a light-shielding film having a spacer function, characterized in that it contains components (A) to (E) as essential components, including (A) an alkali-soluble resin containing a polymerizable unsaturated group; , (B) a photopolymerizable monomer having at least three ethylenically unsaturated bonds, (C) a photopolymerization initiator, (D) an insulating carbon having a surface resistivity of ¹ The pencil hardness of the cured product of the composition excluding the light-shielding component containing black, the solvent (E), and the component (D) is HB or higher.

Description

Photosensitive resin composition, light shielding film, liquid crystal display device, and method of manufacturing a liquid crystal display device {PHOTOSENSITIVE RESIN COMPOSITION, LIGHT-SHIELDING FILM THEREOF, AND MANUFACTURING PROCESS OF LCD WITH THAT FILM}

The present invention relates to a photosensitive resin composition and a light-shielding film obtained by curing the same, and more specifically, to a photosensitive resin composition capable of forming a black column spacer having both a spacer function and a black matrix function in a liquid crystal display device by a photolithography method. It relates to a resin composition and its cured film. The present invention also relates to a liquid crystal display device using the black column spacer obtained by curing the above. The present invention also relates to a method of manufacturing the above liquid crystal display device.

In recent years, color liquid crystal displays (LCDs) have been used in all fields, such as liquid crystal televisions, liquid crystal monitors, and color liquid crystal mobile phones. Among them, in order to improve the performance of LCDs, improvements aimed at improving characteristics such as viewing angle, contrast, and response speed are being actively made, and various panel structures are also being developed for thin-film transistor (TFT)-LCDs, which are currently widely used. It is being developed. For TFT-LCD, the conventional method of manufacturing an array substrate and a color filter substrate on which the TFT is formed separately and bonding the two substrates together while maintaining them at a constant interval with a spacer has been mainly adopted.

As for the spacer, which functions to keep the thickness of the liquid crystal layer constant (in the conventional method, the gap between the array substrate and the color filter (CF) substrate), which is a factor affecting the performance of LCD, conventionally, it has a constant particle size. The method used was to insert a ball spacer in between. However, this method has a problem in that the dispersion state of the ball spacers becomes non-uniform, causing the amount of light transmitted for each pixel to become inconsistent. To solve this problem, a method of forming a column spacer using a photolithography method is adopted. However, column spacers formed by photolithography are often transparent, and such column spacers have a problem in that light incident from an oblique direction affects the electrical characteristics of the TFT and deteriorates display quality. In response to this problem, an LCD panel structure using a light-shielding column spacer, which is a light-shielding film with a spacer function formed by a photolithography method, has been proposed (Patent Document 1).

This light-shielding column spacer requires 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 with different heights can be formed simultaneously at the point where the TFT is formed and at other points. In addition, light-shielding column spacers are also required to have appropriate ranges of elastic modulus, deformation amount, elastic recovery rate, etc. as spacer functions (Patent Document 3). In addition, 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 influence of impurities in the colorant, etc. (Patent Document 4).

Japanese Patent Publication No. 08-234212 US Patent Application Publication No. 2009/0303407 Specification Japanese Patent Publication No. 2009-031778 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 disclosed. Although mixed-color organic pigments are more effective in lowering dielectric constant than inorganic pigments such as carbon black, they often have low light blocking properties. In addition, since it is necessary to form spacers of different heights at the same time, the light-shielding column spacer is also required to have mechanical properties such as compression ratio, elastic recovery ratio, and breaking strength. The shape and mechanical properties of such spacers are greatly influenced by the light-shielding component, making it difficult to design a photosensitive resin composition for a light-shielding film. Therefore, the shape and mechanical properties of spacers using carbon black or mixed-color organic pigments are still not satisfactory, and further improvements are required.

Additionally, as described above, the light-shielding column spacer is manufactured with a film thickness of approximately 1 to 7 μm. With the recent miniaturization of liquid crystal display elements, there is a demand for a light-shielding column spacer to be able to form a fine spacer shape even if the film thickness is about 1 to 7 μm. In addition, after providing the functions of a black matrix and a spacer, two substrates sandwiching the liquid crystal layer are bonded with good precision, that is, in order to increase alignment precision, two types of heights of the light-shielding spacer are formed (step difference in ΔH) formation), and furthermore, there are many demands for patterning characteristics, such as forming light-shielding spacers that stand up from the glass substrate as vertically as possible, making it difficult to satisfy all the required characteristics.

The present invention was made in consideration of the above problems, and enables the formation of a light-shielding film with high light-shielding and insulating properties and a spacer function with excellent compression rate, elastic recovery rate, and fracture strength, and is also capable of forming a step of ΔH and has excellent The object is to provide a photosensitive resin composition capable of forming a pattern shape, a light-shielding film having a spacer function formed using the same, and a liquid crystal display device containing the light-shielding film as a component.

The present inventors conducted studies to solve the problems in the photosensitive resin composition for a light-shielding film as described above, and as a result found that a specific colorant was preferable as a light-shielding component of the target photosensitive resin composition for a light-shielding film, and the present invention was completed.

(1) The present invention is a photosensitive resin composition for a light-shielding film having a spacer function, characterized in that it contains the following components (A) to (E) as essential components, comprising: (A) an alkali-soluble resin containing a polymerizable unsaturated group; , (B) a photopolymerizable monomer having at least 3 ethylenically unsaturated bonds, (C) a photopolymerization initiator, (D) a film formed to have an optical density of 4/㎛, and the surface resistivity of the film is 1 × 10 ⁸ Ω/ □ A photosensitive resin composition characterized in that the pencil hardness of the cured product of the composition excluding the light-shielding component containing insulating carbon black, (E) solvent, and component (D) is HB or higher.

(2) The present invention also provides component (B) in an amount of 5 to 400 parts by mass based on 100 parts by mass of component (A), and component (C) in an amount of 0.1 parts by mass based on 100 parts by mass of the total amount of component (A) and component (B). Contains ~40 parts by mass of component (B), which becomes a solid content after photocuring, and contains 5 to 60 mass% of component (D) based on the solid content excluding component (E), respectively, based on the total amount of solid content. The photosensitive resin composition according to (1), characterized in that:

(3) The present invention is also a photosensitive resin composition characterized by using, as component (A), an alkali-soluble resin containing a polymerizable unsaturated group represented by general formula (II).

[Formula 1]

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, R ₅ represents a hydrogen atom or a methyl group, and X is - CO-, -SO ₂ -, -C(CF ₃ ) ₂ -, -Si(CH ₃ ) ₂ -, -CH ₂ -, -C(CH ₃ ) ₂ -, -O-, fluorene-9,9 -Represents a diyl group or a direct bond, Y represents a tetravalent carboxylic acid residue, and Z is each independently a hydrogen atom or -OC-W-(COOH) _l (provided that W is a divalent or trivalent carboxylic acid represents a residue, l represents a number from 1 to 2), and n represents a number from 1 to 20.

(4) The present invention also provides a light-shielding film having an optical density OD of 0.5/μm or more and 4/μm or less, a volume resistivity of 1 × 10 ⁹ Ω·cm or more when a voltage of 10 V is applied, and a dielectric constant of 2 to 10. The photosensitive resin composition according to any one of (1) to (3), characterized in that it can be formed.

(5) The present invention is also characterized in that it is possible to form a light-shielding film that satisfies at least one of the following (i) to (iii) in a load-unload test using a microhardness tester. The photosensitive resin composition according to any one of items to 4. (i) Compression rate is 40% or less, (ii) Elastic recovery rate is 30% or more, (iii) Breaking strength is 200 mN or more.

(6) The present invention is also a light-shielding film with a spacer function, which is formed by curing the photosensitive resin composition according to any one of (1) to (5).

(7) The present invention is also a liquid crystal display device characterized by having the light-shielding film according to (6) as a black column spacer (BCS).

(8) The present invention is the liquid crystal display device according to (7), further comprising a thin film transistor (TFT).

(9) The present invention further provides a method for producing a light-shielding film formed on a substrate, comprising applying the photosensitive resin composition according to any one of (1) to (5) to a substrate and curing the photosensitive resin composition by light irradiation. In this case, with respect to the film thickness H1 for keeping the optical density as a light-shielding film from 0.5/㎛ to 4/㎛ and the film thickness H2 of the light-shielding film that performs the spacer function, when H2 is 1 to 7 ㎛, ΔH = H2 - H1 This is a method of manufacturing a light-shielding film, characterized by simultaneously forming a light-shielding film with a film thickness of 0.1 to 6.9 H1 and a film thickness H2.

(10) The present invention is also a method of manufacturing a liquid crystal display device, characterized in that the light-shielding film manufactured by the method described in (9) is used as a black column spacer.

(11) The present invention is the manufacturing method according to (10), wherein the liquid crystal display device has a thin film transistor (TFT).

Since the photosensitive resin composition for a light-shielding film according to the present invention contains specific insulating carbon black as a colorant, a cured product having excellent compressibility, elastic recovery rate, and fracture strength can be obtained while maintaining light-shielding properties and insulating properties compared to conventional photosensitive resin compositions. You can. In addition, the photosensitive resin composition for a light-shielding film according to the present invention can form a fine spacer shape even if the film thickness is about 1 to 7 μm.

Hereinafter, the present invention will be described in detail.

The alkali-soluble resin containing a polymerizable unsaturated group of component (A) can be any resin having an acidic group in the molecule, such as a polymerizable unsaturated double bond contributing to the photocuring reaction and a carboxyl group contributing to alkali developability, without any particular limitation. Among them, the first example preferably used is an epoxy compound having two glycidyl ether groups derived from bisphenols, preferably an epoxy compound represented by general formula (I), and (meth)acrylic acid (this is "acrylic acid") and/or methacrylic acid") to a hydroxyl group-containing compound (c) containing a polymerizable unsaturated group, (a) tetracarboxylic acid or its acid dianhydride, and (b) dicarboxylic acid. It is an alkali-soluble resin obtained by reacting carboxylic acid or tricarboxylic acid or their acid anhydrides, and has a carboxyl group and a polymerizable unsaturated group in one molecule. Since component (A) has both a polymerizable unsaturated double bond and a carboxyl group, it imparts excellent photocurability, good developability, and patterning properties to the photosensitive resin composition, thereby improving the physical properties of the light shielding film.

[Formula 2]

However, in general formula (I), R ₁ , R ₂ , R ₃ and R ₄ independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom or a phenyl group, and ₂ -, -C(CF ₃ ) ₂ -, -Si(CH ₃ ) ₂ -, -CH ₂ -, -C(CH ₃ ) ₂ -, -O-, or fluorene-9,9-diyl group Alternatively, it represents a single bond, and the average value of m is in the range of 0 to 10, preferably 0 to 3.

Bisphenols that provide epoxy compounds of general formula (I) include bis(4-hydroxyphenyl)ketone, bis(4-hydroxy-3,5-dimethylphenyl)ketone, and bis(4-hydroxy-3). , 5-dichlorophenyl) ketone, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxy-3,5-dimethylphenyl) sulfone, bis (4-hydroxy-3,5-dichlorophenyl) sulfone, Bis(4-hydroxyphenyl)hexafluoropropane, Bis(4-hydroxy-3,5-dimethylphenyl)hexafluoropropane, Bis(4-hydroxy-3,5-dichlorophenyl)hexafluoropropane , bis(4-hydroxyphenyl)dimethylsilane, bis(4-hydroxy-3,5-dimethylphenyl)dimethylsilane, bis(4-hydroxy-3,5-dichlorophenyl)dimethylsilane, bis(4- Hydroxyphenyl)methane, bis(4-hydroxy-3,5-dichlorophenyl)methane, bis(4-hydroxy-3,5-dibromophenyl)methane, 2,2-bis(4-hydroxy Phenyl) 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-bromophenyl) fluorene, 9,9-bis (4 -Hydroxy-3-fluorophenyl)fluorene, 9,9-bis(4-hydroxy-3-methoxyphenyl)fluorene, 9,9-bis(4-hydroxy-3,5-dimethylphenyl) ) Fluorene, 9,9-bis (4-hydroxy-3,5-dichlorophenyl) fluorene, 9,9-bis (4-hydroxy-3,5-dibromophenyl) fluorene, 4, 4'-biphenol, 3,3'-biphenol, etc. can be mentioned. These bisphenols may be used alone or in combination of multiple compounds. Among these, bisphenols in which X in the general formula (I) is a fluorene-9,9-diyl group can be used particularly preferably.

The compound of general formula (I) to be derived from the alkali-soluble resin of (A) is an epoxy compound having two glycidyl ether groups obtained by reacting the above bisphenols with epichlorhydrin. This reaction generally involves oligomerization of the diglycidyl ether compound, and m is an integer from 0 to 10 for each molecule, and is usually an average value because molecules of multiple values are mixed. It can be from 0 to 10 (not limited to an integer), but the preferred average value of m is from 0 to 3. If the average value of m exceeds the upper limit, when using a photosensitive resin composition using an alkali-soluble resin synthesized using the epoxy compound, the viscosity of the composition may become too large, making coating difficult, or alkali solubility cannot be sufficiently provided, resulting in alkali Developability becomes very poor.

Next, the hydroxyl group-containing compound (c) containing a polymerizable unsaturated group obtained from the reaction of an epoxy compound and (meth)acrylic acid is reacted with an acid component to produce an alkali-soluble resin having a carboxyl group and a polymerizable unsaturated group in one molecule. You can get it. As the acid component, it is recommended to use tetracarboxylic acid or its acid dianhydride (a), which can react with a hydroxyl group-containing compound, and dicarboxylic acid or tricarboxylic acid, or its acid monoanhydride (b). good night. The carboxylic acid residue of this acid component may have either saturated hydrocarbon or unsaturated hydrocarbon. Additionally, these carboxylic acid residues may contain a bond containing a hetero element such as -O-, -S-, or carbonyl group.

Specific examples of the acid component are shown below, but dianhydrides and monoanhydrides of the exemplified polyhydric carboxylic acids can also be used.

First, examples of (a) tetracarboxylic acid include chain hydrocarbon tetracarboxylic acid, alicyclic tetracarboxylic acid, or aromatic polyhydric carboxylic acid. Here, examples of chain hydrocarbon tetracarboxylic acids include butane tetracarboxylic acid, pentane tetracarboxylic acid, and hexane tetracarboxylic acid, and may also be tetracarboxylic acids into which arbitrary substituents have been introduced. do. Moreover, examples of alicyclic tetracarboxylic acids include cyclobutane tetracarboxylic acid, cyclopentane tetracarboxylic acid, cyclohexane tetracarboxylic acid, cycloheptane tetracarboxylic acid, and norbornane tetracarboxylic acid. etc., and further may be tetracarboxylic acid into which an arbitrary substituent has been introduced. Examples of aromatic tetracarboxylic acids include pyromellitic acid, benzophenone tetracarboxylic acid, biphenyl tetracarboxylic acid, and biphenyl ether tetracarboxylic acid, and further include optional substituents. It may be tetracarboxylic acid into which is introduced. These (a) tetracarboxylic acids may be used only as one type of compound, or may be used in combination of plurality.

Additionally, (b) dicarboxylic acid or tricarboxylic acid includes chain hydrocarbon dicarboxylic acid or tricarboxylic acid, alicyclic dicarboxylic acid or tricarboxylic acid, aromatic dicarboxylic acid or tricarboxylic acid. Boxylic acid is used. Here, the chain hydrocarbon dicarboxylic acid or tricarboxylic acid includes, for example, succinic acid, acetylsuccinic acid, maleic acid, adipic acid, itaconic acid, azelaic acid, citramalic acid, malonic acid, glutaric acid, Citric acid, tartaric acid, oxoglutaric acid, pimelic acid, sebacic acid, suberic acid, diglycolic acid, etc. may be used, and may also be dicarboxylic acid or tricarboxylic acid with an arbitrary substituent introduced. In addition, examples of alicyclic dicarboxylic acids or tricarboxylic acids include cyclobutanedicarboxylic acid, cyclopentanedicarboxylic acid, hexahydrophthalic acid, tetrahydrophthalic acid, and norbornanedicarboxylic acid. Furthermore, it may be dicarboxylic acid or tricarboxylic acid into which an arbitrary substituent is introduced. Furthermore, aromatic dicarboxylic acids or tricarboxylic acids include, for example, phthalic acid, isophthalic acid, trimellitic acid, etc., and may also be dicarboxylic acids or tricarboxylic acids into which arbitrary substituents have been introduced. . These (b) dicarboxylic acids or tricarboxylic acids may be used as one type of compound or in combination of multiple compounds.

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 in the alkali-soluble resin of (A) is, It is 0.01 to 0.5, preferably 0.02 or more and less than 0.1. If the molar ratio (b)/(a) deviates from the above range, it is not preferable because the optimal molecular weight for producing the photosensitive resin composition of the present invention with high light blocking and high resistance and good light patterning properties cannot be obtained. Additionally, the smaller the molar ratio (b)/(a), the higher the alkali solubility and the higher the molecular weight tends to be.

Regarding the ratio of reacting the hydroxyl group-containing compound (c) containing the above-mentioned polymerizable unsaturated group with the acid components (b) and (a), the molar ratio of each component is preferably such that the terminal of the compound is a carboxyl group ( It is preferable to carry out the reaction quantitatively so that c) : (b) : (a) = 1 : 0.2 ~ 1.0 : 0.01 ~ 1.0. In this case, the reaction is carried out quantitatively so that the molar ratio of the total amount of the acid component to the hydroxyl group-containing compound (c) containing a polymerizable unsaturated group is (c)/[(b)/2 + (a)] = 0.5 to 1.0. It is desirable. If this molar ratio is less than 0.5, the terminal of the alkali-soluble resin becomes an acid anhydride, and the content of unreacted acid dianhydride increases, raising concerns about a decrease in the stability of the alkali-soluble resin composition over time. On the other hand, when the molar ratio exceeds 1.0, the content of the hydroxyl group-containing compound containing unreacted polymerizable unsaturated groups increases, and there is concern about a decrease in the stability over time of the alkali-soluble resin composition. The molar ratio of each component (a), (b), and (c) can be arbitrarily changed within the above-mentioned range for the purpose of adjusting the acid value and molecular weight of the alkali-soluble resin.

The alkali-soluble resin of (A) can be manufactured by a known method, for example, a method described in Japanese Patent Application Laid-Open No. 8-278629 or Japanese Patent Application Publication No. 2008-9401, etc., using the procedures described above. First, as a method of reacting (meth)acrylic acid with an epoxy compound of general formula (I), for example, (meth)acrylic acid, which is equimolar to the epoxy group of the epoxy compound, is added to a solvent, and a catalyst (triethylbenzylammonium chloride) is added to the solvent. , 2,6-diisobutylphenol, etc.), by heating and stirring to 90 to 120°C while blowing air to cause the reaction. Next, as a method of reacting an acid anhydride with the hydroxyl group of the epoxy acrylate compound, which is a reaction product, a predetermined amount of the epoxy acrylate compound and acid dianhydride and acid monoanhydride are added to a solvent, and a catalyst (tetraethylammonium bromide, There is a method of reacting by heating and stirring at 90 to 140°C in the presence of (triphenylphosphine, etc.).

The alkali-soluble resin of (A) produced in this way has, for example, a structure represented by general formula (II).

[Formula 3]

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, R ₅ represents a hydrogen atom or a methyl group, and X is - CO-, -SO ₂ -, -C(CF ₃ ) ₂ -, -Si(CH ₃ ) ₂ -, -CH ₂ -, -C(CH ₃ ) ₂ -, -O-, fluorene-9,9 -Represents a diyl group or a direct bond, Y represents a tetravalent carboxylic acid residue, and Z is each independently a hydrogen atom or -OC-W-(COOH) _l (provided that W is a divalent or trivalent carboxylic acid represents a residue, l represents a number from 1 to 2), and n represents a number from 1 to 20.

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

As a second example of the alkali-soluble resin containing an unsaturated group as component A, an alkali-soluble resin obtained by radical polymerization of (meth)acrylic acid and various (meth)acrylic acid esters is further reacted with glycidyl (meth)acrylate. Examples include an alkali-soluble resin containing a polymerizable unsaturated group, which is obtained by

Examples of (meth)acrylic acid esters copolymerized with the above-mentioned (meth)acrylic acid include (meth)acrylic acid esters, (meth)acrylic acid amide, styrene and its derivatives, maleic anhydride and its derivatives, vinyl ethers, olefins, etc. can be mentioned.

(meth)acrylic acid esters or amides are 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), and known ones can be used without particular limitation. there is. 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 group, etc. Monovalent alkyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, 4-methylcyclohexyl group, adamantyl group, isobornyl group, dicyclofentanyl group, dicyclopentanyl group, which may be substituted in a linear, branched or alicyclic structure. Monovalent alicyclic hydrocarbon groups such as clopentenyl group, monovalent aromatic hydrocarbon groups such as phenyl group, tolyl group, mesityl group, naphthyl group, anthryl group, benzyl group, 2-phenylethyl group, pyridyl group, piperidyl group, pipe Ridino group, pyrrolyl group, pyrrolidinyl group, imidazolyl group, imidazolidinyl group, prolyl group, tetrahydrofuryl group, thienyl group, tetrahydrothienyl group, morpholinyl group, morpholino group, quinolyl group, etc. and saturated or unsaturated monovalent heterocyclic groups. In addition, at any position of the above-mentioned hydrocarbon group and heterocyclic group, a halogen atom, hydroxyl group, sulfanyl group, carbonyl group, thiocarbonyl group, carboxyl group, thiocarboxyl group, dithiocarboxyl group, formyl group, 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, Structures in which a thiourei group or the like is introduced as a substituent can also be mentioned.

The weight average molecular weight (Mw) of the alkali-soluble resin of (A) in terms of polystyrene as measured by gel permeation chromatography (GPC) is usually 1,000 to 50,000, and is preferably 2,000 to 15,000. If the weight average molecular weight is less than 1000, the adhesion of the pattern during alkali development may decrease, and if the weight average molecular weight exceeds 50000, the developability may decrease or the desired hardness may not be achieved when cured with light or heat. There is a risk that it may become difficult to form a composition. In addition, in the case of an alkali-soluble resin of general formula (II), the preferred weight average molecular weight is 2000 to 10000, more preferably 3000 to 7000.

Moreover, the preferable range of the acid value of the alkali-soluble resin of (A) is 30 to 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, penetration of the alkaline developer becomes too fast and a peeling phenomenon occurs, so neither is preferable. In addition, as for the alkali-soluble resin containing a polymerizable unsaturated group (A), only one type may be used, or a mixture of two or more types may be used.

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

Next, (B) photopolymerizable monomers having at least three ethylenically unsaturated bonds include, for example, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, and pentaerythritol tri( Meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, sorbitol penta(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa (meth)acrylic acid esters such as (meth)acrylate, sorbitol hexa(meth)acrylate, alkylene oxide-modified hexa(meth)acrylate of phosphazene, and caprolactone-modified dipentaerythritol hexa(meth)acrylate, Examples include vinyl benzyl ether compounds of polyhydric alcohols (pentaerythritol, dipentaerythritol, etc.) and polyhydric phenols (phenol novolac, etc.), and addition polymers of divinyl compounds such as divinylbenzene. These (B) photopolymerizable monomers having at least three ethylenically unsaturated bonds may be used as one type of compound or may be used in combination of plurality. Additionally, (B) the photopolymerizable monomer having at least three ethylenically unsaturated bonds does not have a free carboxyl group.

The mixing ratio of component (B) is preferably 5 to 400 parts by mass, and preferably 10 to 150 parts by mass, based on 100 parts by mass of component (A). If the mixing ratio of component (B) is more than 400 parts by mass with respect to 100 parts by mass of component (A), the cured product after photocuring becomes brittle, and the acid value of the coating film in the unexposed area is low, so the solubility in an alkaline developer is low. This causes problems such as the pattern edges becoming jagged and not sharp. On the other hand, if the mixing ratio of component (B) is less than 5 parts by mass with respect to 100 parts by mass of component (A), the proportion of photoreactive functional groups in the resin is small and the formation of a crosslinked structure is not sufficient, and furthermore, the resin component Since the acid value is high, the solubility in the alkaline developer in the exposed area increases, so there is a risk that problems such as the formed pattern becoming thinner than the target line width or pattern missing easily occur.

In addition, the photopolymerization initiator of component (C) includes, for example, acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, and trichloroacetophenone. , acetophenones such as p-tert-butylacetophenone, benzophenones such as benzophenone, 2-chlorobenzophenone, and p,p'-bisdimethylaminobenzophenone, benzyl, benzoin, benzoin methyl ether, benzo Benzoin ethers such as phosphorus isopropyl ether and benzoin isobutyl ether, 2-(o-chlorophenyl)-4,5-phenylbiimidazole, 2-(o-chlorophenyl)-4,5-di ( m-methoxyphenyl)biimidazole, 2-(o-fluorophenyl)-4,5-diphenylbiimidazole, 2-(o-methoxyphenyl)-4,5-diphenylbiimidazole, Biimidazole-based compounds such as 2,4,5-triarylbiimidazole, 2-trichloromethyl-5-styryl-1,3,4-oxadiazole, 2-trichloromethyl-5-( Halomethyldiazole compounds such as p-cyanostyryl)-1,3,4-oxadiazole and 2-trichloromethyl-5-(p-methoxystyryl)-1,3,4-oxadiazole Logistics, 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(trichloro Methyl)-1,3,5-triazine, 2-(4-methoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(3,4, 5-trimethoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methylthiostyryl)-4,6-bis(trichloromethyl) -Halomethyl-s-triazine compounds such as 1,3,5-triazine, 1,2-octanedione, 1-[4-(phenylthio)phenyl]-,2-(O-benzoyloxime), 1-(4-phenylsulfanylphenyl)butane-1,2-dione-2-oxime-O-benzoate, 1-(4-methylsulfanylphenyl)butane-1,2-dione-2-oxime-O -Acetate, 1-(4-methylsulfanylphenyl)butan-1-one oxime-O-acetate, ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3- 1]-,1-(0-acetyloxime), methanone,(9-ethyl-6-nitro-9H-carbazol-3-yl)[4-(2-methoxy-1-methylethoxy)- 2-methylphenyl]-, 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 O-acyloxime compounds such as -7-nitro-9H-fluoren-2-yl)-, 1-O-acetyloxime, benzyldimethyl ketal, thioxanthone, 2-chlorothioxanthone, 2,4 -Sulfur compounds such as diethylthioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, 2-ethylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-di Anthraquinones such as phenylanthraquinone, organic peroxides such as azobisisobutylnitrile, benzoyl peroxide, cumene peroxide, 2-mercaptobenzoimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole Thiol compounds such as these can be mentioned. Among these, it is preferable to use O-acyloxime-based compounds from the viewpoint of easily obtaining a highly sensitive photosensitive resin composition for a light-shielding film. These (C) photopolymerization initiators may be used only as one type of compound or may be used in combination of plurality. In addition, the photopolymerization initiator as used in the present invention is used to include a sensitizer.

These photopolymerization initiators and sensitizers can be used individually or in combination of two or more. In addition, compounds that do not act as a photopolymerization initiator or sensitizer by themselves but can increase the ability of the photopolymerization initiator or sensitizer by using them in combination can also be added. Examples of such compounds include tertiary amines such as triethanolamine and triethylamine, which are effective when used in combination with benzophenone.

The amount of the photopolymerization initiator of component (C) used is preferably 0.1 to 40 parts by mass, preferably 1 to 25 parts by mass, based on a total of 100 parts by mass of component (A) and component (B). If the mixing ratio of component (C) is less than 0.1 parts by mass, the speed of photopolymerization slows and sensitivity decreases, while if it exceeds 40 parts by mass, sensitivity becomes too strong and the pattern line width becomes thick compared to the pattern mask. There is a risk that problems may occur, such as not being able to faithfully reproduce the line width on the mask, or the pattern edges becoming jagged and not sharp.

The (D) component has a film thickness of 10 to 1.5 μm and an optical density of a composition containing 5 to 20 mass% of the (D) component and 5 to 15 mass% of the (A) component in the (E) component. It is a light-shielding component containing insulating carbon black whose surface resistivity of the film formed to be 4/㎛ is 1 × 10 ⁸ Ω/□ or more. The insulating carbon black that may be contained in such a light-shielding component needs to be insulated on the surface of the carbon black by various methods, but the insulating treatment method is not particularly limited. Examples of insulating treatment methods include coating with resin (e.g., Japanese Patent Application Laid-Open No. 9-95625), and oxidizing treatment with an oxidizing agent (e.g., Japanese Patent Application Laid-Open No. 11-181326). , a method of grafting with a polymer compound having a reactive group (e.g., Japanese Patent Application Laid-Open No. 9-265006), a method of chemical modification with an organic group (e.g., Japanese Patent Application Publication No. 2008-517330), grafting A method of combining reaction and coating with a resin (for example, Japanese Patent Application Laid-Open No. 2002-249678), a method of coating with a pigment (for example, International Publication No. 2013/129555), etc. are known.

As the D component, two or more types of insulating carbon black can be used, black organic pigments such as perylene black, aniline black, cyanine black, and lactam black, and red, blue, green, purple, yellow, cyanine, and magenta pigments. Organic pigments can also be used together. The selection of the light-shielding component containing these carbon blacks as an essential ingredient needs to be made taking into account insulation, heat resistance, light resistance, solvent resistance, etc., and in some cases, a combination of light-shielding components can be selected so that black can be made achromatic. .

In addition, solvents for component (E) include, for example, methanol, ethanol, n-propanol, isopropanol, ethylene glycol, propylene glycol, 3-methoxy-1-butanol, ethylene glycol monobutyl ether, and 3-hydroxy. -Alcohols such as 2-butanone and diacetone alcohol, terpenes such as α- or β-terpineol, etc., ketones such as acetone, methyl ethyl ketone, cyclohexanone, and N-methyl-2-pyrrolidone. , aromatic hydrocarbons such as toluene, xylene, tetramethylbenzene, cellosolve, methyl cellosolve, ethyl cellosolve, carbitol, methylcarbitol, ethylcarbitol, butylcarbitol, propylene glycol monomethyl ether, propylene Glycol ethers such as glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monomethyl ether, and triethylene glycol monoethyl ether, ethyl acetate, butyl acetate, ethyl lactate, 3-meth Toxybutyl acetate, 3-methoxy-3-methylbutyl acetate, cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, carbitol acetate, ethyl carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether Examples include esters such as acetate and propylene glycol monoethyl ether acetate, and by dissolving and mixing them, a uniform solution-like composition can be obtained. Two or more types of these solvents may be used to achieve necessary properties such as coating properties.

The light-shielding component containing these insulating carbon blacks as an essential component is preferably dispersed in advance with a dispersant (F) in a solvent to form a carbon black dispersion, and then blended as a photosensitive resin composition for a light-shielding film. Here, since the dispersing solvent becomes a part of component (E), any solvent listed in the above-mentioned component (E) can be used. For example, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, etc. are preferable. It is used widely. The mixing ratio of the insulating carbon black (D) forming the carbon black dispersion is preferably in the range of 5 to 60% by mass based on the total solid content of the photosensitive resin composition for a light-shielding film of the present invention. In addition, the solid content means components other than component (E) in the composition. The solid content also includes component (B), which becomes solid 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 serves as the original binder, decreases, causing the undesirable problem of impeding development characteristics and impairing film-forming ability.

The average particle size (hereinafter referred to as “average secondary particle size”) of the light-shielding component in this 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 together, it is preferable that the average secondary particle size of the dispersed particles is 20 to 500 nm. Also, in the photosensitive resin composition for a light-shielding film prepared by blending these carbon black dispersions, it is preferable that these light-shielding components have the same average secondary particle size.

Additionally, as the (F) dispersant, known dispersants such as various polymer dispersants can be used. Examples of dispersants include known compounds conventionally used for dispersing pigments (compounds sold under the names of dispersants, dispersion wetting agents, dispersion accelerators, etc.) without particular restrictions, for example, cationic polymer-based dispersants, Examples include ionic polymeric dispersants, nonionic polymeric dispersants, and pigment derivative-type dispersants (dispersing aids). In particular, as an adsorption point to the pigment, it has a cationic functional group such as an imidazolyl group, pyrrolyl group, pyridyl group, primary, secondary or tertiary amino group, and has an amine value of 1 to 100 mgKOH/g, water A cationic polymer-based dispersant having an average molecular weight in the range of 10,000 to 100,000 is preferable. The blending amount of this dispersant is preferably 1 to 30% by mass, preferably 2 to 25% by mass, relative to the light-shielding component containing insulating carbon black as an essential component.

In addition, when preparing a carbon black dispersion, a portion of the alkali-soluble resin containing a polymerizable unsaturated group of component (A) is co-dispersed in addition to the above-mentioned dispersant, so that exposure sensitivity can be maintained at high sensitivity when used as a photosensitive resin composition for a light-shielding film. It can be made with a photosensitive resin composition that is easy to use, has good adhesion during development, and does not easily cause residue problems. The compounding amount of component (A) is preferably 2 to 20% by mass, and more preferably 5 to 15% by mass, based on the carbon black dispersion liquid. If the component (A) is less than 2% by mass, codispersed effects such as improved sensitivity, improved adhesion, and reduced residue cannot be obtained. Moreover, if it is 20% by mass or more, especially when the content of the light-shielding component containing insulating carbon black as an essential component is large, the viscosity of the carbon black dispersion is high, and it is difficult or very time-consuming to uniformly disperse it. It becomes difficult to obtain a photosensitive resin composition to obtain a coating film in which insulating carbon black is dispersed.

The carbon black dispersion obtained in this way consists of component (A) (if component (A) is codispersed when preparing the carbon black dispersion, the remaining component (A)), component (B), component (C), and the remainder. By mixing with (E) component, it can be used as a photosensitive resin composition for a light-shielding film.

Additionally, additives such as a curing accelerator, a thermal polymerization inhibitor, an antioxidant, a plasticizer, a filler, a leveling agent, an antifoaming agent, a coupling agent, and a surfactant can be added to the photosensitive resin composition of the present invention as needed. Examples of thermal polymerization inhibitors and antioxidants include hydroquinone, hydroquinone monomethyl ether, pyrogallol, tert-butylcatechol, phenothiazine, hindered phenol compounds, etc., and plasticizers include dibutyl phthalate. , dioctyl phthalate, tricresyl phosphate, etc., fillers include glass fiber, silica, mica, alumina, etc., and leveling agents and antifoaming agents include silicone-based, fluorine-based, and acrylic compounds. . Additionally, coupling agents include 3-(glycidyloxy)propyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, and 3-ureidopropyltriethoxy. Silane coupling agents such as silane can be used, and examples of surfactants include fluorine-based surfactants and silicone-based surfactants.

The photosensitive resin composition of the present invention may be used in combination with other resin components that polymerize or harden by heat. As other resin components, (G) an epoxy resin or epoxy compound having two or more epoxy groups is preferable, such as 3,3',5,5'-tetramethyl-4,4'-biphenol type epoxy resin, bisphenol A-type epoxy resin, bisphenol fluorene-type epoxy resin, phenol novolak-type epoxy resin, 3,4-epoxycyclohexenylmethyl-3',4'-epoxycyclohexenecarboxylate, 2,2-bis(hydroxymethyl )-1-butanol's 1,2-epoxy-4-(2-oxilanyl)cyclohexane adduct, epoxy silicone resin, etc. As for these additional components, only one type of compound may be used, or a plurality of compounds may be used in combination.

The photosensitive resin composition of the present invention contains the above components (A) to (E) as main components. In the solid content, it is preferable that components (A) to (D) are contained in a total of 70% by mass, preferably 80% by mass or more. (E) Although the amount of the solvent changes depending on the target viscosity, it is preferably contained in the photosensitive resin composition in the range of 60 to 90 mass%. When the (G) component is used together, the ratio (mass %) of (G)/{(A) + (B) + (G)} is preferably 5 to 30%, and more preferably 10 to 20%. desirable.

The photosensitive resin composition of the present invention is characterized in that the hardness of the cured film of the composition excluding the insulating carbon black (component D), which is a light-shielding component, is set to a certain level or higher. The film forming conditions for the cured film for measuring this hardness are photocuring conditions and heat curing conditions used when obtaining a desired pattern using the photosensitive resin composition of the present invention. For example, the composition for hardness measurement consisting of components (A) to (C) and (E) is spin coated on a glass substrate with a spinner, dried by heating at a temperature of 60 to 110 ° C. for 1 to 3 minutes, and then dried under ultra-high pressure. Using an exposure apparatus equipped with a mercury lamp, a predetermined amount of exposure is performed without a photomask, and the cured film for hardness measurement is manufactured by further thermal curing at 180 to 250°C for 20 to 60 minutes. And when the pencil hardness of the cured film is measured, it is good to obtain a cured film with a pencil hardness of HB or higher. More preferably, components (A) to (C) and, as appropriate, additives such as (G) an epoxy resin or epoxy compound or a curing accelerator are added to obtain a pencil hardness of H or higher, thereby forming the photosensitive resin composition of the present invention. good night. If the pencil hardness is softer than HB, there is a possibility that problems such as insufficient elastic recovery rate in mechanical properties as a spacer may occur. In particular, when the content of light-blocking components such as carbon black is small, the effect may be significant.

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

In order to strengthen the hardness of the cured film, crosslinking between molecules of the alkali-soluble resin containing a polymerizable unsaturated group ((A) component) formed during photocuring and crosslinking between the (A) component and the polymerizable monomer ((B) component) It is necessary to design the selection of component (A) and the selection and mixing ratio of component (B) so that the crosslinking of is more than a certain amount. When the molecular weight of component (A) increases and the content of polymerizable unsaturated groups per molecule decreases, it becomes difficult to increase the amount of crosslinking. If the molecular weight of component (A) is too large, there is a tendency for it to become difficult to increase the amount of crosslinking formed between components (A) and between components (A) and (B), even if the content of polymerizable unsaturated groups in one molecule is large. There is a need to consider. Additionally, unless component (B) has three or more polymerizable unsaturated groups, it is difficult to increase the amount of crosslinking. In addition, since the physical properties of the cured product are influenced by the structure of the alkali-soluble resin and the structure of the polymerizable monomer, these factors are also taken into consideration to select the components (A) and (B) to be combined and design the mixing ratio.

The photosensitive resin composition for a light-shielding film in the present invention is excellent as a photosensitive resin composition for forming, for example, a light-shielding film with a spacer function. A method of forming a light-shielding film having a spacer function includes the following photolithography method. First, the photosensitive resin composition for a light-shielding film according to the present invention is applied onto a substrate, the solvent is then dried (prebaked), a photomask is placed on the film thus obtained, and the exposed area is cured by irradiating ultraviolet rays. Then, development is performed to elute the unexposed area using an aqueous alkaline solution to form a pattern, and further post-baking (thermal baking) is performed as post-drying.

The substrate may be a transparent substrate, or may be a substrate other than a transparent substrate, such as an alignment film formed on a pixel after forming RGB pixels, on a flattening film on a pixel, or on a flattening film on a pixel. The type of substrate on which the light-shielding film having a spacer function is formed varies depending on the design of the liquid crystal display device.

Transparent substrates to which the photosensitive resin composition is applied include, in addition to glass substrates, transparent electrodes such as ITO or gold deposited or patterned on transparent films (e.g., polycarbonate, polyethylene terephthalate, polyethersulfone, etc.). can be exemplified. As a method of applying a solution of the photosensitive resin composition on a transparent substrate, in addition to the known solution dipping method and spraying method, any method such as a method using a roller coater, a land coater, a slit coater, or a spinner can be adopted. there is. By these methods, a film is formed by applying to the desired thickness and then removing the solvent (prebaking). Prebaking is performed by heating using an oven, hot plate, etc. The heating temperature and heating time in prebaking are appropriately selected depending on the solvent to be used, and are performed, for example, at a temperature of 60 to 110°C for 1 to 3 minutes.

Exposure performed after prebaking is performed using an ultraviolet exposure device, and only the portion of the resist corresponding to the pattern is exposed through a photomask. The exposure apparatus and its exposure irradiation conditions are appropriately selected, 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 deep ultraviolet ray, and the photosensitive resin composition in the coating film is photocured.

Alkaline development after exposure is performed for the purpose of removing resist in unexposed areas, and a desired pattern is formed through this development. Examples of developing solutions suitable for this alkaline phenomenon include aqueous solutions of carbonates of alkali metals and alkaline earth metals, and aqueous solutions of hydroxides of alkali metals. In particular, carbonates such as sodium carbonate, potassium carbonate, and lithium carbonate are used in an amount of 0.05 to 3 mass. It is recommended to develop at a temperature of 23 to 28°C using a slightly alkaline aqueous solution containing %, and a fine image can be precisely formed using a commercially available developer or ultrasonic cleaner.

After development, heat treatment (post-baking) is preferably performed under conditions of 180 to 250°C and 20 to 60 minutes. This post-bake is performed for the purpose of increasing the adhesion between the patterned light shielding film and the substrate. Similar to prebake, this is done by heating using an oven, hot plate, etc. The patterned light-shielding film of the present invention is formed through each process by the photolithography method described above.

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

In addition, according to the above method, with respect to the film thickness H1 for setting the optical density as a light-shielding film to 0.5/μm or more and 4/μm or less, and the film thickness H2 of the light-shielding film that performs the spacer function, when H2 is 1 to 7 μm, ΔH = H2 - H1 is 0.1 to 6.9, and a light-shielding film with a film thickness of H1 and a light-shielding film with a film thickness of H2 can be formed simultaneously. A more preferable range is the optical density as a light shielding film of 0.5/μm to 3/μm, H2 of 2 to 5 μm, and ΔH of 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 for a liquid crystal display device, and can preferably be used as a black column spacer. According to the cured film in which ΔH is in the above range, black column spacers with different heights can be formed at once from the same material, so the liquid crystal display device can be manufactured more efficiently. At this time, for example, the cured film with a film thickness of H2 can function as a spacer, and the cured film with a film thickness of H1 can also function as a black matrix. In addition, the height H2 of the spacer and the thickness H1 of the light-shielding film are determined as appropriate values by the design of the two substrates sandwiching the liquid crystal layer, and the appropriate range of H1, or ΔH, is determined in accordance with the value of H2.

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

The liquid crystal display device having the light-shielding film or cured film has high light-shielding and insulating properties, and further has a spacer function with excellent elastic modulus, deformation amount, and elastic recovery rate, and can form a fine spacer shape even when the film thickness is about 1 to 7 μm. can do.

[Example]

Hereinafter, embodiments of the present invention will be specifically described based on Examples and Comparative Examples, but the present invention is not limited to these.

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

[Solids concentration]

1 g of the resin solution obtained in the synthesis example was impregnated and weighed in a glass filter [weight: W0 (g)], and the weight [W2 (g)] after heating at 160°C for 2 hours was calculated from the following formula. Saved.

Solids concentration (% by weight) = 100 × (W2 - W0)/(W1 - W0).

[Sanga]

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

[Molecular Weight]

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

In addition, the symbols used in synthesis examples and comparative synthesis examples are as follows.

BPFE: Reaction product of 9,9-bis(4-hydroxyphenyl)fluorene and chloromethyloxirane. In the compound of general formula (I), X is fluorene-9,9-diyl, R ₁ , R ₂ are hydrogen.

BPDA: 3,3',4,4'-biphenyltetracarboxylic acid dianhydride

BTDA: 3,3',4,4'-benzophenone tetracarboxylic dianhydride

THPA: 1,2,3,6-tetrahydrophthalic anhydride

TPP: Triphenylphosphine

PGMEA: Propylene glycol monomethyl ether acetate

[Synthesis Example 1]

Into a 1 L four-necked flask equipped with a reflux condenser, 116.7 g (0.23 mol) of BPFE, 33.1 g (0.46 mol) of acrylic acid, 0.60 g of TPP, and 161.0 PGMEA were charged and stirred for 12 hr under heating at 100 to 105°C. The reaction product was obtained.

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, and stirred for 6 hr under heating at 115 to 120°C to obtain an alkali-soluble resin solution containing a polymerizable unsaturated group (A)- got 1 The solid content concentration of the obtained resin solution was 56.5 wt%, the acid value (converted to solid content) was 102 mgKOH/g, and the Mw according to GPC analysis was 3600.

[Comparative Synthesis Example 1]

In a 1000 mL four-neck 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, and azobisisobutyro 5.91 g of nitrile and 370 g of diethylene glycol dimethyl ether were added and polymerized by stirring at 80 to 85°C under a nitrogen stream for 8 hours. Additionally, 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 into the flask, stirred at 80 to 85°C for 16 hr, Alkali-soluble resin solution (A)-2 was obtained. The solid content concentration of the obtained resin solution was 32% by mass, the acid value (converted to solid content) was 110 mgKOH/g, and the Mw according to GPC analysis was 18100.

(Alkali-soluble resin containing polymerizable unsaturated group)

(A)-1 Component: Alkali-soluble resin solution obtained in Synthesis Example 1 above

(A)-2 Component: Alkali-soluble resin solution obtained in Comparative Synthesis Example 1 above

(Photopolymerizable monomer)

(B): Mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (manufactured by Nippon Gunpowder Co., Ltd., brand 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 Ir) Gacure OXE02)

(carbon black dispersion)

(D)-1: PGMEA dispersion (solid content 30.0%) with a resin-coated carbon black concentration of 25.0 mass% and a dispersant concentration of 5.0 mass%.

(D)-2: PGMEA dispersion containing 20.0% by mass of carbon black and 5.0% by mass of polymer dispersant (solid content: 25%)

(solvent)

(E)-1:PGMEA

(E)-2: 3-methoxy-3-methyl-1-butylacetate

(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 (Product name: KBM-803: manufactured by Shin-Etsu Chemical Co., Ltd.)

(Surfactants)

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

[Evaluation of composition components]

<Preparation of composition for evaluating the properties of carbon black>

The resin solution (component (A)-1), the carbon black dispersion (component (D)-1 or (D)-2) and the solvent (component (E)-1) are mixed to a solid content concentration of 20%, A composition for measuring carbon black was prepared. The carbon black concentration was adjusted while measuring the optical density (OD), and a composition capable of forming a cured film with OD = 4/μm was prepared. The composition used for surface resistivity measurement is shown in Table 1.

＜Optical density＞

The composition for measuring carbon black obtained above was applied to a glass substrate with a thickness of 1.2 mm using a spin coater so that the film thickness after heat curing was 1.1 μm, and prebaked at 90°C for 1 minute. After that, heat curing 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 as 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 Analytical Co., Ltd.). The measurement results are shown in Table 1.

<Preparation of a composition for evaluating the properties of photocurable components>

Photocuring components shown in Table 2 using a resin solution (component (A)-1), a photopolymerizable monomer (component (B)), a photopolymerization initiator (component (C)), and a solvent (component (E)-1). A composition for evaluating properties was prepared.

＜Measurement of pencil hardness＞

Each photosensitive resin composition obtained above was applied to a glass substrate having a thickness of 1.2 mm using a spin coater so that the film thickness after heat curing was 1.2 μm, and prebaked at 90° C. for 1 minute. After that, without a photomask, 100 mJ/cm 2 of ultraviolet rays were irradiated with an ultra-high pressure mercury lamp with a wavelength of 365 nm and an illuminance of 30 mW/cm 2 to perform a photocuring reaction. After that, heat curing was performed at 230°C for 30 minutes using a hot air dryer to obtain a cured film of the photocurable component.

For this cured film, in accordance with the 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 Hiuni”.

Evaluation as a photosensitive resin composition having a spacer function was performed by mixing the above-described mixing components in the ratios shown in Table 3 to prepare the photosensitive resin compositions of Examples 1 to 5 and Comparative Examples 1 to 3. In addition, all numerical values in Table 3 represent parts by mass. In addition, (E)-1 in the solvent column is PGMEA (same as (E)-1) in the unsaturated group-containing resin solution (alkali-soluble resin solution containing polymerizable unsaturated group), and PGMEA ((( E) Same as -1) is the amount that does not contain.

[Evaluation of composition for light-shielding film]

The evaluation described below was performed using the photosensitive resin composition for light shielding films of Examples 1 to 5 and Comparative Examples 1 to 3. These evaluation results are shown in Table 4.

＜Phenomena characteristics＞

Each of the photosensitive resin compositions obtained above was thermally cured on a glass substrate with a thickness of 1.2 mm using a spin coater so that the film thickness was 3.0 µm (Examples 1, 2, 4 and Comparative Example 3) or 1.5 µm (Example). 3, 5 and Comparative Examples 1 and 2) were applied and prebaked at 90°C for 1 minute. After that, the photomask was brought into close contact, and ultraviolet rays of 100 mJ/cm 2 were irradiated with an ultra-high pressure mercury lamp with a wavelength of 365 nm and an illuminance of 30 mW/cm 2 to perform a photocuring reaction of the photosensitive portion.

Next, the glass substrate after this exposure was developed for 60 seconds at 24°C and a pressure of 0.1 MPa using a 0.05% potassium hydroxide aqueous solution, and the unexposed portion of the coating film was removed. After that, heat curing was performed at 230°C for 30 minutes using a hot air dryer, and a cured film of the photosensitive resin composition was obtained.

The formation of fine lines in the obtained cured film pattern was confirmed under an optical microscope and evaluated in the following three steps. The results are shown in Table 4.

○: A pattern with L/S of 10 ㎛/10 ㎛ or more is formed without residue.

△: A pattern with L/S of 30 ㎛/30 ㎛ or more is formed without residue.

×: A pattern with L/S of less than 50 ㎛/50 ㎛ is not formed, or the shape of the pattern is collapsed or residues are prominent.

＜Volume resistivity＞

Each of the photosensitive resin compositions obtained above was applied to the Cr-deposited 1.2 mm thick glass substrate except for the electrode using a spin coater so that the film thickness after heat curing was 3.5 ㎛, and prebaked at 90°C for 1 minute. did. After that, heat curing was performed at 230°C for 30 minutes using a hot air dryer to obtain a cured film of the photosensitive resin composition. Afterwards, an aluminum electrode was formed on the cured film to prepare a substrate for measuring volume resistivity. Next, the volume resistivity at an applied voltage of 1 V to 10 V was measured using an electrometer (“Type 6517A” manufactured by Castle Ray). It was measured under the condition of maintaining the voltage for 60 seconds at each applied voltage in 1 V steps, and the volume resistivity when 10 V was applied is shown in Table 4.

＜Dielectric constant＞

Each of the photosensitive resin compositions obtained above was applied to the Cr-deposited 1.2 mm thick glass substrate except for the electrode using a spin coater so that the film thickness after heat curing was 3.5 ㎛, and prebaked at 90°C for 1 minute. did. After that, heat curing was performed at 230°C for 30 minutes using a hot air dryer to obtain a cured film of the photosensitive resin composition. Afterwards, an aluminum electrode was formed on the cured film to prepare a substrate for measuring dielectric constant. Next, the electric capacitance at a frequency of 1 Hz to 100000 Hz was measured using an electrometer (“Type 6517 A” manufactured by Case Ray), and the dielectric constant was calculated from the electric capacitance. The calculated dielectric constants are shown in Table 4.

＜Halftone (HT) characteristics of spacer＞

Each of the photosensitive resin compositions obtained above was thermally cured on a glass substrate with a thickness of 1.2 mm using a spin coater so that the film thickness was 3.0 µm (Examples 1, 2, 4 and Comparative Example 3) or 1.5 µm (Example). 3, 5 and Comparative Examples 1 and 2) were applied and prebaked at 90°C for 1 minute. After that, a photomask with a dot pattern is placed in close contact, and ultraviolet rays of 5 mJ/cm2 or 100 mJ/cm2 are irradiated with an ultra-high pressure mercury lamp with a wavelength of 365 nm and an illuminance of 30 mW/cm2 to perform a photocuring reaction of the photosensitive portion. did.

Next, the glass substrate after this exposure was developed for 60 seconds at 24°C and a pressure of 0.1 MPa using a 0.05% potassium hydroxide aqueous solution, and the unexposed portion of the coating film was removed. After that, heat curing was performed at 230°C for 30 minutes using a hot air dryer, and a cured film of the photosensitive resin composition was obtained.

The halftone characteristics of the spacer are calculated by calculating the difference (ΔH) between the film thickness of the light-shielding film (H1) at an exposure dose of 5 mJ/cm2 and the film thickness (H2) of the spacer at an exposure dose of 100 mJ/cm2, and 3 below. It was evaluated in stages. The results are shown in Table 4.

○: When ΔH is 1.0 ㎛ to 2.0 ㎛

△: When ΔH is 0.1 ㎛ to 2.9 ㎛

×: When ΔH is less than 0.1 ㎛ or greater than 2.9 ㎛

＜Compression rate, elastic recovery rate, and breaking strength of spacer＞

Each of the photosensitive resin compositions obtained above was applied to a glass substrate with a thickness of 1.2 mm using a spin coater so that the film thickness after heat curing was 3.0 μm, and prebaked at 90°C for 1 minute. After that, a photomask with a dot pattern was brought into close contact, and ultraviolet rays of 100 mJ/cm 2 were irradiated with an ultra-high pressure mercury lamp with a wavelength of 365 nm and an illuminance of 30 mW/cm 2 to perform a photocuring reaction of the photosensitive portion.

Next, the glass substrate after this exposure was developed for 60 seconds at 24°C and a pressure of 0.1 MPa using a 0.05% potassium hydroxide aqueous solution, and the unexposed portion of the coating film was removed. After that, heat curing was performed at 230°C for 30 minutes using a hot air dryer, and a cured film of the photosensitive resin composition was obtained.

The spacer properties of the obtained cured film pattern were evaluated using an ultra-micro hardness tester (Fisher Scope HM2000Xyp, manufactured by Fisher Instruments). A flat indenter measuring 100 μm in width and height was pressed in at a loading speed of 5.0 mN/sec, and a load of up to 50 mN was applied, then unloaded at an unloading speed of 5.0 mN/sec to create a displacement curve.

The compression ratio was calculated from the following equation, with L1 being the amount of displacement under a load of 50 mN.

Compression rate (%) = L1/height of spacer × 100

The elastic recovery rate was calculated from the following equation, with the displacement amount under a load of 50 mN at the time of load being L1 and the displacement amount at the time of unloading being L2.

Elastic recovery rate (%) = (L1 - L2)/L1 × 100

The breaking strength was evaluated using an ultramicro hardness meter (Fisher Scope HM2000Xyp, manufactured by Fisher Instruments). A flat indenter measuring 100 ㎛ by 100 ㎛ was pressed in at a load speed of 5.0 mN/sec, and a load of up to 300 mN was applied to measure the load when the spacer was destroyed, and evaluated in the following four steps. The results are shown in Table 4.

○: When the breaking strength is 300 mN or more

△: When the breaking strength is less than 200 mN and less than 300 mN

×: When the breaking strength is 100 mN or less and less than 200 mN

＜Shape of spacer＞

Each of the photosensitive resin compositions obtained above was applied to a glass substrate with a thickness of 1.2 mm using a spin coater so that the film thickness after heat curing was 3.0 μm, and prebaked at 90°C for 1 minute. After that, a photomask with a dot pattern was brought into close contact, and ultraviolet rays of 100 mJ/cm 2 were irradiated with an ultra-high pressure mercury lamp with a wavelength of 365 nm and an illuminance of 30 mW/cm 2 to perform a photocuring reaction of the photosensitive portion.

Next, the glass substrate after this exposure was developed for 60 seconds at 24°C and a pressure of 0.1 MPa using a 0.05% potassium hydroxide aqueous solution, and the unexposed portion of the coating film was removed. After that, heat curing was performed at 230°C for 30 minutes using a hot air dryer, and a cured film of the photosensitive resin composition was obtained.

The shape of the spacer was evaluated by the internal angle (taper angle) of the end of the spacer using a scanning electron microscope. When the taper angle was 70° or more and 90° or less, it was marked as ◎, when it was 50° or more but less than 70°, it was marked as ○, when it was 50° or less, it was marked as △, and when it was 90° or more, it was marked as ×.

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

Claims (11)

A photosensitive resin composition for a light-shielding film having a spacer function, characterized in that it contains components (A) to (E) as essential components,
(A) alkali-soluble resin containing a polymerizable unsaturated group,
(B) a photopolymerizable monomer having at least three ethylenically unsaturated bonds (however, excluding (meth)acrylate monomers having an acidic group),
(C) photopolymerization initiator,
(D) A light-shielding component containing insulating carbon black having a surface resistivity of ¹ A light-shielding component, which is a cured film obtained by curing the composition prepared by mixing, and
(E) solvent;
(D) A photosensitive resin composition characterized in that the cured product of the composition excluding the component has a pencil hardness of HB or more. According to claim 1,
5 to 400 parts by mass of component (B) based on 100 parts by mass of component (A),
The component (C) is 0.1 to 40 parts by mass based on 100 parts by mass of the total amount of component (A) and component (B), and the components excluding component (E), which contains component (B) that becomes a solid content after photocuring, are added as solid content. When doing so,
(D) 5 to 60 mass% of the total solid content,
A photosensitive resin composition characterized by containing each. According to claim 1,
(A) A photosensitive resin composition characterized by using, as a component, an alkali-soluble resin containing a polymerizable unsaturated group represented by general formula (II).
[Formula 1]

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, R ₅ represents a hydrogen atom or a methyl group, and X is -CO- , -SO ₂ -, -C(CF ₃ ) ₂ -, -Si(CH ₃ ) ₂ -, -CH ₂ -, -C(CH ₃ ) ₂ -, -O-, fluorene-9,9-di represents a single group or a direct bond, Y represents a tetravalent carboxylic acid residue, and Z is each independently a hydrogen atom or -OC-W-(COOH) _l (however, W represents a divalent or trivalent carboxylic acid residue , l represents a number from 1 to 2), and n represents a number from 1 to 20. According to claim 1,
A light-shielding film having an optical density OD of 0.5/㎛ or more and 4/㎛ or less, characterized in that it is possible to form a light-shielding film having a volume resistivity of 1 × 10 ⁹ Ω·cm or more when a voltage of 10 V is applied and a dielectric constant of 2 to 10. Photosensitive resin composition. According to claim 1,
A photosensitive resin composition capable of forming a light-shielding film that satisfies at least one of the following (i) to (iii) in a load-unload test using a microhardness tester.
(i) Compression ratio of 40% or less
(ii) Elastic recovery rate of 30% or more
(iii) A breaking strength of 200 mN or more. A light-shielding film having a spacer function, which is formed by curing the photosensitive resin composition according to any one of claims 1 to 5. A liquid crystal display device comprising the light-shielding film according to claim 6 as a black column spacer (BCS). According to claim 7,
A liquid crystal display device further comprising a thin film transistor (TFT). A method for producing a light-shielding film formed on a substrate, comprising applying the photosensitive resin composition according to any one of claims 1 to 5 to a substrate and curing the photosensitive resin composition by light irradiation, wherein the optical density as the light-shielding film is OD Regarding the film thickness H1 to be 0.5/㎛ or more and 4/㎛ or less, and the film thickness H2 of the light-shielding film that performs the spacer function, when H2 is 1 to 7 ㎛, ΔH = H2 - H1 is 0.1 to 6.9. A method of manufacturing a light-shielding film, characterized by simultaneously forming a light-shielding film with a thickness H1 and a film thickness H2. A method of manufacturing a liquid crystal display device, characterized in that the light-shielding film manufactured by the method according to claim 9 is used as a black column spacer. According to claim 10,
A method of manufacturing a liquid crystal display device, characterized in that the liquid crystal display device has a thin film transistor (TFT).