KR102377333B1 - A photosensitive resin composition for flexible substrate, color filter and display device comprising the same - Google Patents

Abstract

The present invention relates to a photosensitive resin composition for flexible substrates containing an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator, and a solvent with a polarity of 3.5 to 8, and exhibits excellent adhesion to a flexible substrate.

Description

Photosensitive resin composition for flexible substrate, color filter and display device comprising the same {A photosensitive resin composition for flexible substrate, color filter and display device comprising the same}

The present invention relates to a photosensitive resin composition for flexible substrates, a color filter containing the same, and a display device, and more specifically, to a photosensitive resin composition for flexible substrates containing an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator, and a solvent having a polarity of 3.5 to 8. It relates to a photosensitive resin composition, a color filter containing the same, and a display device.

Color filters are widely used in imaging devices, liquid crystal displays (LCDs), etc., and their application range is rapidly expanding. Color filters used in color liquid crystal displays or imaging devices are usually made by applying a colored photosensitive resin composition containing pigments corresponding to each color of red, green, and blue uniformly by spin coating on a substrate on which a black matrix pattern is formed. Afterwards, the formed coating film is heated and dried (hereinafter sometimes referred to as “pre-baking”), exposed, developed, and, if necessary, further heated and hardened (hereinafter sometimes referred to as “post-baking”) for each color. It is manufactured by repeatedly forming pixels of each color. Here, the black matrix on which the pattern is formed is usually formed of a black photosensitive resin composition.

Recently, display methods have changed from the conventional CRT (Cathode Ray Tube) to flat panel displays such as plasma displays (Plasma display panel (PDP), liquid crystal displays (LCD), organic light emitting diodes (OLED), etc. In particular, research is being actively conducted around the world to realize these flat displays as flexible displays in the future.

The flat display as described above basically uses a glass substrate as a substrate. In general flat displays, high temperature heat treatment is required as a condition for forming a TFT (thin film transistor), so a glass substrate was used as the most suitable material for this.

However, since glass substrates are fundamentally too hard, there is a problem in that they are not suitable as substrates for flexible displays due to their low flexibility.

Generally, plastic substrates such as polycarbonate (PB) or polyimide (PI) are used as substrates for flexible displays. However, when a color filter is manufactured using the above substrate, problems arise as the conventional colored photosensitive resin composition has poor adhesion to the flexible substrate, and cracks occur when the flexible substrate is bent after application. .

Therefore, there is a need to develop a photosensitive resin composition with excellent adhesion to a flexible substrate.

The purpose of the present invention is to provide a photosensitive resin composition for flexible substrates with excellent adhesion to the flexible substrate.

Additionally, the present invention aims to provide a color filter and a liquid crystal display device manufactured using the photosensitive resin composition for a flexible substrate.

In order to achieve the above purpose,

The present invention provides a photosensitive resin composition for a flexible substrate containing an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator, and a solvent having a polarity of 3.5 to 8.

Additionally, the present invention provides a color filter containing the photosensitive resin composition for flexible substrates.

Additionally, the present invention provides a display device including the color filter.

The photosensitive resin composition for a flexible substrate of the present invention has excellent adhesion to a flexible substrate, and has the advantage of not generating cracks when the flexible substrate is bent after applying the photosensitive resin composition for a flexible substrate to the flexible substrate. there is.

Additionally, flexible color filters and display devices can be manufactured using the photosensitive resin composition for flexible substrates of the present invention.

Figure 1 is a graph showing the results of X-ray Photoelectron Spectroscopy (XPS) analysis of Experimental Example 2.
Figure 2 is a graph showing the results of X-ray Photoelectron Spectroscopy (XPS) analysis of a polyimide substrate coated with an N-methylpyrrolidone solution containing silver nanoparticles of Experimental Example 2.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a photosensitive resin composition for a flexible substrate containing an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator, and a solvent having a polarity of 3.5 to 8.

The photosensitive resin composition for flexible substrates of the present invention has excellent adhesion to flexible substrates and can be applied to flexible substrates.

In general, flexible substrates use polymer substrates such as polycarbonate (PB) or polyimide (PI). These flexible substrates have a melting problem if the photosensitive resin composition has high polarity, and the flexible substrate and the photosensitive resin composition have a melting problem. It has the disadvantage of poor adhesion between resin compositions.

Accordingly, the present invention was intended to solve the above problems and improve adhesion to the flexible substrate by using a solvent with a polarity of 3.5 to 8.

Hereinafter, the photosensitive resin composition of the present invention will be described in detail for each component.

(A) Alkali soluble resin

In the present invention, the alkali-soluble resin includes one or more structural units selected from the group consisting of the following formulas 1 to 4.

[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

One or more structural units selected from the group consisting of Formulas 1 to 4 are included in an amount of 3 to 80 mol%, preferably 5 to 70 mol%, based on the total number of moles of the alkali-soluble resin.

When at least one structural unit selected from the group consisting of Formulas 1 to 4 is included in an amount of 3 to 80 mol% based on the total number of moles of the alkali-soluble resin, the sensitivity and adhesion of the photosensitive resin composition are improved, so that the pattern during the development process of the color filter is improved. Peeling does not occur and solvent resistance is excellent.

Additionally, the alkali-soluble resin may be prepared by copolymerizing at least one structural unit selected from the group consisting of Formulas 1 to 4 with a monomer containing an unsaturated bond.

The type of monomer containing the unsaturated bond is not particularly limited, and specific examples include tyrene, vinyltoluene, α-methylstyrene, p-chlorostyrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, o-vinylbenzyl methyl ether, m-vinylbenzyl methyl ether, p-vinylbenzyl methyl ether, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether and p-vinylbenzyl glycidyl ether. Aromatic vinyl compounds such as cidyl ether;

Methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, Alkyl (meth)acrylates such as sec-butyl (meth)acrylate and t-butyl (meth)acrylate;

Cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-methylcyclohexyl (meth)acrylate, tricyclo[5.2.1.0 2,6]decan-8-yl(meth)acrylate, 2- Alicyclic (meth)acrylates such as dicyclofentanyloxyethyl (meth)acrylate and isobornyl (meth)acrylate;

Aryl (meth)acrylates such as phenyl (meth)acrylate and benzyl (meth)acrylate;

Hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate;

N-cyclohexylmaleimide, N-benzylmaleimide, N-phenylmaleimide, N-o-hydroxyphenylmaleimide, N-m-hydroxyphenylmaleimide, N-p-hydroxyphenylmaleimide, N-o-methylphenylmaleimide, N-m -N-substituted maleimide compounds such as methylphenylmaleimide, N-p-methylphenylmaleimide, N-o-methoxyphenylmaleimide, N-m-methoxyphenylmaleimide, and N-p-methoxyphenylmaleimide;

unsaturated amide compounds such as (meth)acrylamide and N,N-dimethyl (meth)acrylamide;

3-(methacryloyloxymethyl)oxetane, 3-(methacryloyloxymethyl)-3-ethyloxetane, 3-(methacryloyloxymethyl)-2-trifluoromethyloxetane, 3-(methacryloyloxymethyl)-2-phenyloxetane, 2-(methacryloyloxymethyl)oxetane and 2-(methacryloyloxymethyl)-4-trifluoromethyloxetane, etc. unsaturated oxetane compounds; etc. can be mentioned.

The monomers containing the above unsaturated bonds can be used individually or in combination of two or more types.

In addition, as the alkali-soluble resin, if necessary, known alkali-soluble resins commonly used in the art may be additionally used.

The alkali-soluble resin has a weight average molecular weight of 3,000 to 100,000, preferably 5,000 to 50,000.

If the weight average molecular weight is less than 3,000, the molecular weight of the alkali-soluble resin is too small, so the surface of the pattern made from the photosensitive resin composition is found to be uneven, and if the weight average molecular weight exceeds 100,000, the problem of slow development speed occurs. .

In addition, the alkali-soluble resin has an acid value of 30 to 250 (KOH mg/g), preferably 50 to 200, and more preferably 60 to 150.

When the acid value of the alkali-soluble resin is 30 to 250, solubility in a developer and residual film rate are improved. On the other hand, if the acid value of the alkali-soluble resin is less than 30, development is difficult, and if it exceeds 250, hydrophilicity increases and other reliability problems occur.

The acid value is a value measured in mg of potassium hydroxide required to neutralize 1 g of acrylic polymer, and can usually be obtained by titration using an aqueous potassium hydroxide solution.

In the present invention, the alkali-soluble resin is included in an amount of 5 to 15% by weight, preferably 5 to 10% by weight, based on the total weight of the photosensitive resin composition for a flexible substrate of the present invention.

Within the range of 5 to 15% by weight, the solubility of the developer is sufficient to facilitate pattern formation, and film reduction of the pixel portion of the exposed area is prevented during development, thereby improving the omission of non-pixel portions.

(B) photopolymerizability compound

In the present invention, a photopolymerizable compound refers to a material that polymerizes and hardens upon exposure to light such as ultraviolet rays, and must be a compound that can be polymerized by the action of a photopolymerization initiator (C), which will be described later.

The number of functional groups of the photopolymerizable compound is not particularly limited, but monofunctional monomers, difunctional monomers, or polyfunctional monomers may be used, preferably bifunctional monomers.

Specific examples of the monofunctional monomer include nonylphenylcarbitol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-ethylhexylcarbitol acrylate, 2-hydroxyethyl acrylate, or N-vinylpy. Lolidon, etc., but is not limited thereto.

The bifunctional photopolymerizable compounds include, for example, 1,6-hexanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, and triethylene glycol di(meth)acrylate. Acrylate, bis(acryloyloxyethyl) ether of bisphenol A, or 3-methylpentanediol di(meth)acrylate.

In addition, the trifunctional or more multifunctional photopolymerizable compounds include, for example, trimethylol propane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, and propoxylated trimethylolpropane tri(meth)acrylate. ) Acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, ethoxylated dipentaerythritol hexa(meth)acrylate, Propoxylated dipentaerythritol hexa(meth)acrylate or dipentaerythritol hexa(meth)acrylate.

The photopolymerizable compound is contained in an amount of 5 to 15% by weight, preferably 7 to 10% by weight, based on the total weight of the photosensitive resin composition for a flexible substrate of the present invention.

The photopolymerizable compound can improve the strength and flatness of the pixel portion in the range of 5 to 15% by weight.

(C) light curing initiator

The photopolymerization initiator can be used without particular restrictions as long as it can polymerize the photopolymerizable compound (B). In particular, the photopolymerization initiator (C) is an acetophenone-based compound, a benzophenone-based compound, a triazine-based compound, a thioxanthone-based compound, an oxime-based compound, etc. from the viewpoint of polymerization characteristics, initiation efficiency, absorption wavelength, availability, price, etc. It is preferable to use at least one compound selected from the group consisting of benzoin-based compounds, anthracene-based compounds, anthraquinone-based compounds, and biimidazole-based compounds.

The acetophenone-based compounds specifically include, for example, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 2-hydroxy-1-[4-( 2-hydroxyethoxy)phenyl]-2-methylpropan-1-one, 1-hydroxycyclohexylphenylketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1 -one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one and 2-hydroxy-2-methyl[4-(1-methylvinyl)phenyl]propane-1 -one oligomers, etc. are mentioned, and among them, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one is preferable.

The benzophenone-based compounds specifically include, for example, benzophenone, benzoyl benzoic acid, methyl benzoyl benzoate, 4-phenyl benzophenone, hydroxy benzophenone, acrylated benzophenone, 4,4'-bis(dimethyl amino)benzophenone, and 4,4'-bis(diethylamino)benzophenone, etc. can be mentioned.

The triazine-based compound specifically includes, for example, 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2-(3′ ,4′-dimethoxy styryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4′-methoxy naphthyl)-4,6-bis(trichloromethyl)-s -triazine, 2-(p-methoxy phenyl)-4,6-bis(trichloro methyl)-s-triazine, 2-(p-tryl)-4,6-bis(trichloro methyl)-s -Triazine, 2-biphenyl-4,6-bis(trichloromethyl)-s-triazine, bis(trichloromethyl)-6-styryl-s-triazine, 2-(naphtho 1-yl )-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxynaphtho 1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2, Examples include 4-trichloromethyl(piperonyl)-6-triazine and 2,4-trichloromethyl(4'-methoxy styryl)-6-triazine.

The thioxanthone-based compounds specifically include, for example, 2-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, and 1-chloro-4-propoxythioxanthone. Santon, etc. can be mentioned.

Specific examples of the oxime-based compounds include o-ethoxycarbonyl-α-oxyimino-1-phenylpropan-1-one, and commercially available products include Ciba's OXE-01 and OXE-02. am.

Specific examples of the benzoin-based compound include benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, and benzyldimethyl ketal.

The anthracene-based compounds specifically include, for example, 9,10-dimethoxyanthracene, 2-ethyl-9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, and 2-ethyl-9,10-diethoxyanthracene. etc. can be mentioned.

Specific examples of the anthraquinone-based compounds include 2-ethyl anthraquinone, octamethyl anthraquinone, 1,2-benz anthraquinone, and 2,3-diphenyl anthraquinone.

The biimidazole-based compounds specifically include, for example, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenylbiimidazole, 2,2'-bis(2 ,3-dichlorophenyl)-4,4′,5,5′-tetraphenylbiimidazole, 2,2′-bis(2-chlorophenyl)-4,4′,5,5′-tetra(alkoxyphenyl) ) Biimidazole, 2,2′-bis(2-chlorophenyl)-4,4′,5,5′-tetra(trialkoxyphenyl)biimidazole and phenyl group at 4,4′,5,5′ positions Examples include imidazole compounds substituted with a carboalkoxy group.

In addition, the photopolymerization initiator may further include a photopolymerization initiation auxiliary agent in order to improve the sensitivity of the photosensitive resin composition for a flexible substrate of the present invention. By including a photopolymerization initiation aid, the photosensitive resin composition for a flexible substrate according to the present invention can further improve sensitivity and increase productivity when forming a column spacer for maintaining a cell gap.

The photopolymerization initiation aid may preferably be, for example, one or more compounds selected from the group consisting of amine-based compounds, alkoxyanthracene-based compounds, and thioxanthone-based compounds.

The amine-based compounds specifically include, for example, triethanolamine, methyldiethanolamine, triisopropanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, and benzoic acid-2- Dimethylaminoethyl, 4-dimethylaminobenzoic acid 2-ethylhexyl, N,N-dimethylparatoluidine, 4,4'-bis(dimethylamino)benzophenone (common name, Michler's ketone), 4,4'-bis( Diethylamino)benzophenone and 4,4'-bis(ethylmethylamino)benzophenone are included, and among these, 4,4'-bis(diethylamino)benzophenone is preferable.

The alkoxyanthracene-based compounds specifically include, for example, 9,10-dimethoxyanthracene, 2-ethyl-9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, and 2-ethyl-9,10-diethoxy. Anthracene, etc. can be mentioned.

The thioxanthone-based compounds specifically include, for example, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, and 1-chlorothioxanthone. -4-propoxythioxanthone, etc. can be mentioned.

In addition, the photopolymerization initiation aid can be used as a commercially available product, for example, the EAB-F series (Hodogaya Chemical Co., Ltd.) can be used.

In the present invention, the photopolymerization initiator may be included in an amount of 0.01 to 10% by weight, preferably 0.01 to 5% by weight, based on the total weight of the photosensitive resin composition for a flexible substrate of the present invention.

If the photopolymerization initiator is included in an amount of less than 0.01% by weight, the polymerization rate may be low and the overall process time may be prolonged, and if it is included in more than 10% by weight, the reaction may occur excessively and the physical properties of the coating film may be reduced due to a crosslinking reaction. .

In addition, when the photopolymerization initiation auxiliary agent is additionally used, the photopolymerization initiation auxiliary agent is included in an amount of 0.01 to 5 moles, preferably 0.01 to 3 moles, per 1 mole of the photopolymerization initiator.

When the photopolymerization initiation aid is included in an amount of 0.01 to 5 mol, polymerization efficiency is improved and productivity is improved.

(D)Solvent

In the present invention, a solvent having a polarity index of 3.5 to 8 is used.

By using the above solvent, adhesion to the flexible substrate can be improved.

Generally, flexible substrates use polymer substrates such as polycarbonate (poly carbonate, PB) or polyimide (PI). The flexible substrate melts when the polarity is high, but since the solvent of the photosensitive resin composition for a flexible substrate of the present invention has a polarity of 3.5 to 8, it can prevent the above phenomenon from occurring.

Solvents having a polarity of 3.5 to 8 include n-butyl alcohol (3.9), isopropyl alcohol (3.9), n-butyl acetate (4.0), and isobutyl alcohol ( isobutyl alcohol, 4.0), methyl isoamyl ketone, 4.0, n-propyl alcohol, 4.0, tetrahydrofuran, 4.0, chloroform, 4.1, methyl iso Butyl ketone (methyl isobutyl ketone, 4.2), ethyl acetate (4.4), methyl n-propyl ketone (4.2), methylethyl ketone (4.7), 1,4-dioxene (1,4-dioxane, 4.8), acetone (5.1), methanol (5.1), 2-methoxyethanol (2-methoxyethanol 5.5), acetonitrile (5.8), propylene carbonate , 6.1), and at least one selected from the group consisting of solvents containing nitrogen and solvents containing sulfur.

In addition, solvents containing nitrogen (N) with a polarity of 3.5 to 8 include dimethylacetamide (6.5), dimethylformamide (6.4), formamide (7.3), and N-methyl-2. -Includes at least one member selected from the group consisting of N-methyl-2-pyrrolidone (6.7) and pyridine (5.3).

In addition, the solvent containing sulfur (S) with a polarity of 3.5 to 8 includes at least one selected from the group consisting of dimethyl sulfoxide (7.2) and dimethyl sulfone (6.5).

The solvent having a polarity of 3.5 to 8 is included in a residual amount so that the total weight of the photosensitive resin composition for a flexible substrate of the present invention is 100% by weight.

In addition, the solvent of the present invention can be used in addition to a solvent having a polarity of 3.5 to 8.

The type of solvent that can be additionally used is not particularly limited as long as it can dissolve or disperse the photosensitive resin composition for a flexible substrate of the present invention, but specifically, alkylene glycol monoalkyl ethers, diethylene glycol alkyl ethers, and alkyl ethers. Examples include ren glycol alkyl ether acetates, aromatic hydrocarbons, ketones, alcohols, and cyclic esters.

Specific examples of the alkylene glycol monoalkyl ethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether.

Specific examples of the diethylene glycol dialkyl ethers include diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, and diethylene glycol dibutyl ether.

The alkylene glycol alkyl ether acetates specifically include, for example, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, and methoxy. Butyl acetate, methoxypentyl acetate, etc. are mentioned.

Specific examples of the aromatic hydrocarbons include benzene, toluene, xylene, and mesitylene.

Specific examples of the ketones include methyl amyl ketone and cyclohexanone.

Specific examples of the alcohols include ethanol, hexanol, cyclohexanol, ethylene glycol, and glycerin.

Specific examples of the cyclic esters include ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, and γ-butyrolactone.

The solvents exemplified above can be used individually or in combination of two or more.

In addition, in terms of applicability and drying properties, among the above solvents, a solvent having a boiling point of 100 to 200° C. is preferably used, and specific examples include alkylene glycol alkyl ether acetates, ketones, and esters, and more specifically, propylene. Glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, cyclohexanone, ethyl 3-ethoxypropionate, or methyl 3-methoxypropionate. The above solvents can be used individually or in combination of two or more types.

In addition, when the solvent of the present invention is mixed with a solvent having a polarity of 3.5 to 8 and other solvents, they are mixed at a weight ratio of 9:1 to 1:9, preferably 4:1 to 1:4. and use it.

When mixed and used at a weight ratio of 9:1 to 1:9, maximum mass productivity can be achieved in the existing process.

(E) Colorant

The photosensitive resin composition for a flexible substrate of the present invention may further include a colorant.

The colorant is characterized in that it contains one or more pigments, one or more dyes, or mixtures thereof.

( e1 )Pigment

The pigment may be an organic pigment or an inorganic pigment commonly used in the field. In addition, the pigment may be subjected to resin treatment, surface treatment using pigment derivatives into which acidic or basic groups are introduced, etc., grafting treatment of the pigment surface with a polymer compound, atomization treatment by sulfuric acid atomization method, etc., as necessary, and treatment to remove impurities. Washing treatment with an organic solvent or water, or removal treatment of ionic impurities using an ion exchange method, etc. may be performed.

The organic pigment can be a variety of pigments used in printing ink, inkjet ink, etc. Specifically, water-soluble azo pigment, insoluble azo pigment, phthalocyanine pigment, quinacridone pigment, isoindolinone pigment, isoindoline pigment, Perirene pigment, perrinone pigment, dioxazine pigment, anthraquinone pigment, dianthraquinonyl pigment, anthrapyrimidine pigment, antanthrone pigment, indanthrone pigment, pravanthrone pigment, pyranthrone pigment, diketopyrroropyrrole pigment etc. can be mentioned.

In addition, as the inorganic pigment, metal compounds such as metal oxides and metal complex salts can be used, and specifically, iron, cobalt, aluminum, cadmium, lead, copper, titanium, magnesium, chromium, zinc, antimony, carbon black, organic Examples include metal oxides or complex metal oxides such as black pigments, titanium black, and pigments that produce black color by mixing red, green, and blue.

In particular, the organic pigments and inorganic pigments include compounds classified as pigments in the color index (published by The Society of Dyers and Colourists).

The pigment is included in an amount of 5 to 60% by weight, preferably 10 to 45% by weight, based on the total weight of solids in the photosensitive resin composition for a flexible substrate. When the pigment is included in an amount of 5 to 60% by weight, the color density of the pixel is sufficient even when forming a thin film, and the missingness of the non-pixel portion is not reduced during development, so no residue is generated, which is preferable.

It is preferable to use a pigment dispersion in which the pigment particle size is uniformly dispersed. Examples of methods for uniformly dispersing the particle size of the pigment include dispersion treatment by containing a pigment dispersant (e2). According to the above method, a pigment dispersion in which the pigment is uniformly dispersed in the solution can be obtained. there is.

( e2 )Pigment dispersant

The pigment dispersant is added to deagglomerate the pigment and maintain stability. Specific examples of the pigment dispersant include surfactants such as cationic, anionic, nonionic, amphoteric, polyester, and polyamine types. , these can be used individually or in combination of two or more types.

Specific examples of the cationic surfactant include amine salts such as stearylamine hydrochloride and lauryltrimethylammonium chloride, or quaternary ammonium salts.

Specific examples of the anionic surfactant include higher alcohol sulfate ester salts such as sodium lauryl alcohol sulfate and sodium oleyl alcohol sulfate, alkyl sulfates such as sodium lauryl sulfate and ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, and Alkylaryl sulfonates, such as sodium dodecylnaphthalenesulfonate, etc. are mentioned.

Specific examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene aryl ether, polyoxyethylene alkylaryl ether, other polyoxyethylene derivatives, oxyethylene/oxypropylene block copolymer, sorbitan fatty acid ester, Examples include polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, glycerol fatty acid ester, polyoxyethylene fatty acid ester, and polyoxyethylene alkylamine.

In addition, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyethylene glycol diesters, sorbitan fatty acid esters, fatty acid-modified polyesters, tertiary amine-modified polyurethanes, and polyethylene imines. there is.

In addition, the pigment dispersant preferably includes an acrylate-based dispersant (hereinafter referred to as an acrylate-based dispersant) including butyl methacrylate (BMA) or N,N-dimethylaminoethyl methacrylate (DMAEMA). Commercially available products of the acrylate-based dispersant include DISPER BYK-2000, DISPER BYK-2001, DISPER BYK-2070, or DISPER BYK-2150, and the acrylate-based dispersant can be used alone or in a mixture of two or more types. You can.

In addition to the acrylate-based dispersant, other resin-type pigment dispersants may be used as the pigment dispersant. The other resin-type pigment dispersants include known resin-type pigment dispersants, especially polyurethanes, polycarboxylic acid esters represented by polyacrylates, unsaturated polyamides, polycarboxylic acids, and (partially) of polycarboxylic acids. Amine salts, ammonium salts of polycarboxylic acids, alkylamine salts of polycarboxylic acids, polysiloxanes, long-chain polyaminoamide phosphate salts, esters of hydroxyl-containing polycarboxylic acids and their modified products, or free ) Oily dispersants such as amides or salts thereof formed by the reaction of polyester having a carboxyl group and poly(lower alkyleneimine); Water-soluble resins or water-soluble polymer compounds such as (meth)acrylic acid-styrene copolymer, (meth)acrylic acid-(meth)acrylate ester copolymer, styrene-maleic acid copolymer, polyvinyl alcohol, or polyvinyl pyrrolidone; Polyester; modified polyacrylate; Adduct of ethylene oxide/propylene oxide; and phosphate ester.

Commercially available pigment dispersants of other resin types include cationic resin dispersants, for example, BYK Chemistry's brand names: DISPER BYK-160, DISPER BYK-161, DISPER BYK-162, DISPER BYK-163, DISPER. BYK-164, DISPER BYK-166, DISPER BYK-171, DISPER BYK-182,DISPER BYK-184; BASF's product names: EFKA-44, EFKA-46, EFKA-47, EFKA-48, EFKA-4010, EFKA-4050, EFKA-4055, EFKA-4020, EFKA-4015, EFKA-4060, EFKA-4300, EFKA- 4330, EFKA-4400, EFKA-4406, EFKA-4510, EFKA-4800 ; Lubirzol's brand names: SOLSPERS-24000, SOLSPERS-32550, NBZ-4204/10; Kawaken Fine Chemical Company's product names: HINOACT T-6000, HINOACT T-7000, HINOACT T-8000; Ajinomoto's product names: AJISPUR PB-821, AJISPUR PB-822, AJISPUR PB-823; Product names of Kyoeisha Chemical Company: FLORENE DOPA-17HF, FLORENE DOPA-15BHF, FLORENE DOPA-33, FLORENE DOPA-44, etc. are mentioned.

In addition to the acrylate-based dispersant described above, other resin-type pigment dispersants can be used alone or in a mixture of two or more types, and can also be used in combination with the acrylate-based dispersant.

The pigment dispersant is included in an amount of 5 to 60 parts by weight, preferably 15 to 50 parts by weight, based on 100 parts by weight of solid content in the pigment. If the content of the pigment dispersant exceeds 60 parts by weight, the viscosity increases, and if it is less than 5 parts by weight, it may be difficult to atomize the pigment or cause problems such as gelation after dispersion.

( e3 )dyes

The dye can be used without limitation as long as it has solubility in organic solvents. It is preferable to use a dye that has solubility in organic solvents and can ensure reliability such as solubility in alkaline developers, heat resistance, and solvent resistance.

The dye may be selected from acid dyes having an acidic group such as sulfonic acid or carboxylic acid, salts of acid dyes and nitrogen-containing compounds, sulfonamides of acid dyes, and their derivatives. In addition, azo-based, xanthene-based, and phthalocyanine Acidic dyes and their derivatives may also be selected. Preferably, the dye may be a compound classified as a dye in the color index (published by The Society of Dyers and Colourists) or a known dye described in a dyeing note (color dyeing yarn).

The content of dye in the colorant is 0.5 to 80% by weight, preferably 0.5 to 60% by weight, and more preferably 1 to 50% by weight, based on the total weight of solids in the colorant. If the content of the dye in the colorant is 0.5 to 80% by weight, it is possible to prevent the reliability problem of the dye being eluted by the organic solvent after forming the pattern and increase sensitivity.

The content of the colorant is 5 to 60% by weight, preferably 10 to 45% by weight, based on the total weight of solids in the photosensitive resin composition for flexible substrates. When the colorant is included in the amount of 5 to 60% by weight, the color density of the pixel is sufficient when forming a thin film, and the missingness of the non-pixel portion is not reduced during development, making it difficult to generate residue.

In the present invention, the solid weight in the photosensitive resin composition for a flexible substrate refers to the total weight of the remaining components of the photosensitive resin composition excluding the solvent.

(F) Additives

The additive may be selectively added as needed, and may include, for example, one or more selected from the group consisting of adhesion promoters, surfactants, dispersants, antioxidants, ultraviolet absorbers, thermal polymerization inhibitors, and leveling agents. .

The adhesion promoter includes methacryloyloxy propyltrimethoxy silane, methacryloyloxy propyl dimethoxy silane, methacryloyloxy propyltriethoxy silane, and methacryloyloxy propyldimethoxy silane. One or more types selected from the group consisting of lowyl silane coupling agents can be used, and selected from the group consisting of alkyl trimethoxy silanes such as octyltrimethoxy silane, dodecyltrimethoxy silane, and octadecyltrimethoxy silane. One or more types can be used.

The surfactant may be used as a commercial product such as MCF 350SF, F-475, F-488, and F-552 (manufactured by DIC), but is not limited thereto.

The dispersing agent and leveling agent may be any of those commonly used in the industry.

As the antioxidant, 2,2-thiobis(4-methyl-6-t-butylphenol) and 2,6-g,t-butylphenol can be used.

As the ultraviolet absorber, 2-(3-t-butyl-5-methyl-2-hydroxyphenyl)-5-chloro-benzotriazole and alkoxy benzophenone can be used.

The thermal polymerization inhibitors include hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4-thiobis(3-methyl-6- t-butylphenol), 2,2-methylenebis(4-methyl-6-t-butylphenol), and 2-mercaptoimidazole can be used.

Additionally, in addition to the above additives, functional binder resins, monomers, radiation-sensitive compounds, etc. can be additionally used.

The production of the photosensitive resin composition of the present invention is not particularly limited in the present invention, and the photosensitive resin composition can be produced by a known method.

Additionally, the present invention provides a color filter manufactured from the photosensitive resin composition for a flexible substrate of the present invention and a display device equipped with the same.

First, the photosensitive resin composition for flexible substrates is applied onto the substrate or a previously formed layer made of solid content of the photosensitive resin composition for flexible substrates, and then heated and dried to remove volatile components such as solvents to obtain a smooth coating film.

Here, the flexible substrate is polycarbonate (PB), polyimide (PI), acryl, polyethylene terephthalate (PET), polyether sulfide (PES), liquid crystal polymer ( One or more polymer substrates selected from the group consisting of liquid polymer and poly sulfone (PS) are used.

The application method may be, for example, spin coating, flexible coating, roll coating, slit and spin coating, or slit coating. After application, it is heated and dried (prebake), or dried under reduced pressure and then heated to volatilize volatile components such as solvents. Here, the heating temperature is usually 70 to 200°C, preferably 80 to 150°C, and the heating time is 1 to 30 minutes.

The thickness of the coating film after heat drying is usually about 1 to 8 μm. The coating film thus obtained is irradiated with ultraviolet rays through a mask to form the desired pattern. At this time, it is desirable to use a device such as a mask aligner or stepper so that parallel light is uniformly irradiated to the entire exposure area and the mask and the substrate are accurately aligned. When ultraviolet rays are irradiated, curing occurs in the area irradiated with ultraviolet rays.

As the ultraviolet rays, g-rays (wavelength: 436 nm), h-rays, i-rays (wavelength: 365 nm), etc. can be used. The irradiation amount of ultraviolet rays can be appropriately selected according to need, and is not limited to this in the present invention. A spacer having the desired pattern shape can be obtained by contacting the cured coating film with a developing solution to dissolve the non-exposed portion and developing it.

The development method is not particularly limited to liquid addition method, dipping method, spray method, etc. Additionally, the substrate may be tilted at an arbitrary angle during development. The developer is usually an aqueous solution containing an alkaline compound and a surfactant.

The alkaline compound is not particularly limited to an inorganic or organic alkaline compound. The inorganic alkaline compounds include, for example, sodium hydroxide, potassium hydroxide, disodium hydrogen phosphate, sodium dihydrogen phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, potassium dihydrogen phosphate, sodium silicate, potassium silicate, sodium carbonate, Potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium borate, potassium borate, and ammonia can be mentioned.

In addition, organic alkaline compounds include, for example, tetramethylammonium hydroxide, 2-hydroxyethyltrimethylammonium hydroxide, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, and triethylamine. , monoisopropylamine, diisopropylamine, and ethanolamine.

The inorganic or organic alkaline compounds can be used individually or in combination of two or more. The concentration of the alkaline compound in the developer is 0.01 to 10% by weight, preferably 0.03 to 5% by weight, based on the total weight of the developer.

The surfactant in the developer may be one or more selected from the group consisting of the above-mentioned nonionic surfactants, anionic surfactants, and cationic surfactants. The concentration of the surfactant in the developer is 0.01 to 10% by weight, preferably 0.05 to 8% by weight, and more preferably 0.1 to 5% by weight, based on the total weight of the developer. After development, it may be washed with water and, if necessary, post-baked at 150 to 230°C for 10 to 60 minutes.

The post-bake is performed to increase the adhesion between the patterned resin pattern and the substrate, and is performed by heat treatment at a temperature of 80 to 220 ° C. for 10 to 120 minutes. Additionally, the post-bake is performed using an oven or a hot plate.

Using the photosensitive resin composition for a flexible substrate of the present invention, a specific pattern can be formed on the substrate through each process as described above.

The photosensitive resin pattern obtained through the above method has a size sufficient to maintain high light sensitivity and enable excellent fine pattern formation, and is formed with a thickness of several to several thousand microns, preferably 0.1 to 100 μm, and more preferably 1 to 50 μm. do.

The photosensitive resin pattern not only has excellent adhesion to the flexible substrate, but also has excellent heat resistance and solvent resistance, thereby improving the reliability of the display device.

Hereinafter, the present invention will be described in detail with reference to examples. However, the embodiments according to the present invention may be modified into various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described in detail below. Examples of the present invention are provided to more completely explain the present invention to those with average knowledge in the art.

<Alkali-soluble resin production>

Synthesis example One.

A flask equipped with a stirrer, thermometer reflux cooling pipe, dropping lot, and nitrogen introduction pipe was prepared.

As a monomer dropping lot, a mixture of 3,4-epoxytricyclodecan-8-yl(meth)acrylate and 3,4-epoxytricyclodecan-9-yl(meth)acrylate at a molar ratio of 50:50 40 Parts by weight, 50 parts by weight of methyl methacrylate, 40 parts by weight of acrylic acid, 70 parts by weight of vinyl toluene, 4 parts by weight of t-butylperoxy-2-ethylhexanoate, 40 parts by weight of propylene glycol monomethyl ether acetate (PGMEA). Addition was prepared for stirring.

As a chain transfer agent dropping tank, 6 parts by weight of n-dodecanethiol and 24 parts by weight of propylene glycol monomethyl ether acetate (PGMEA) were added and stirred.

Afterwards, 395 parts by weight of propylene glycol monomethyl ether acetate (PGMEA) was added to the flask, the atmosphere in the flask was changed from air to nitrogen, and the temperature of the flask was raised to 90° C. while stirring.

Next, the monomer and chain transfer agent were started dropwise from the dropping lot. The dropping was carried out for 2 hours while maintaining 90°C, and after 1 hour, the temperature was raised to 110°C and maintained for 5 hours to obtain a resin with a solid acid value of 100 mgKOH/g.

The prepared resin was kept in an oven at 120°C for 50 hours to prepare an alkali-soluble resin from which the solvent was removed.

Measurement of the weight average molecular weight (Mw) and number average molecular weight (Mn) of the alkali-soluble resin was performed using the GPC method under the following conditions, and the ratio of the obtained weight average molecular weight and number average molecular weight was calculated as the molecular weight distribution (Mw/ Mn).

Device: HLC-8120GPC (manufactured by Tosoh Co., Ltd.)

Column: TSK-GELG4000HXL + TSK-GELG2000HXL (serial connection)

Column temperature: 40℃

Mobile phase solvent: tetrahydrofuran

Flow rate: 1.0 mL/min

Injection volume: 50 ㎕

Detector: RI

Measured sample concentration: 0.6% by weight (solvent = tetrahydrofuran)

Standard materials for calibration: TSK STANDARD POLYSTYRENE F-40, F-4, F-1, A-2500, A-500 (manufactured by Tosoh Co., Ltd.)

The weight average molecular weight measured under the above conditions was 17,000, and the molecular weight distribution was 2.3.

< flexible Manufacturing photosensitive resin composition for substrate>

Example 1 to 8 and Comparative example 1 to 2.

Photosensitive resin compositions for flexible substrates of Examples 1 to 8 and Comparative Examples 1 to 2 were prepared using the compositions shown in Table 1 below.

(Unit: weight%) alkali
Availability
profit photopolymerizability
compound light curing
initiator solvent D-1 D-2 D-3 D-4 D-5 D-6 Example 1 10.3 6.8 0.8 82.1 - - - - - Example 2 10.3 6.8 0.8 - 82.1 - - - - Example 3 10.3 6.8 0.8 - - 82.1 - - - Example 4 10.3 6.8 0.8 - - - 82.1 - - Example 5 10.3 6.8 0.8 - - 32.8 - 49.3 - Example 6 12.0 5.1 0.8 - 65.7 - - 16.4 - Example 7 13.7 3.4 0.8 - - - 32.8 49.3 - Example 8 6.3 12.9 0.9 - - 20.0 20.0 39.9 - Comparative Example 1 9.0 7.3 0.8 - - - - 82.9 - Comparative example 2 9.0 7.3 0.8 - - - - - 82.9

Alkali-soluble resin: Alkali-soluble resin prepared in Synthesis Example 1

Photopolymerizable compound: Dipentaerythritol hexaacrylate (KAYARAD DPHA, manufactured by Nippon Kayaku Co., Ltd.)

Photopolymerization initiator: Ethanone-1-[9-ethyl-6-(2-methyl-4-tetrahydropyranyloxybenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime) (Irgacure OXE-02, manufactured by Ciba Specialty Chemical)

solvent

D-1: Methyl ethyl ketone

D-2: N-methylpyrrolidone

D-3: dimethyl sulfoxide

D-4: N,N-dimethylformamide

D-5: Propylene glycol monomethyl ether acetate

D-6: Toluene

Experiment example One. flexible Adhesion measurement of photosensitive resin compositions for substrates

A Sumitomo liquid crystal polymer film measuring 5 × 5 cm was washed with water and dried.

The photosensitive resin compositions for flexible substrates of Examples 1 to 8 and Comparative Examples 1 to 2 were applied to the liquid crystal polymer substrate by spin coating, placed on a heating plate, and dried at a temperature of 80 to 120° C. for 1 to 2 minutes. The solvent was removed.

Afterwards, the liquid crystal polymer film coated with the photosensitive resin composition for a flexible substrate was irradiated with ultraviolet rays. At this time, an ultra-high pressure mercury lamp (product name: USH-250D) manufactured by Ushio Denki Co., Ltd. was used as the ultraviolet light source, and the pattern was formed by irradiating with an exposure dose (365 nm) of 40 to 150 mJ/cm2 in an atmospheric atmosphere.

The liquid crystal polymer film was developed by immersing it in a KOH aqueous developing solution of pH 10.5 for 2 minutes.

The liquid crystal polymer film coated with the photosensitive resin composition for a flexible substrate was washed with distilled water, dried by blowing nitrogen gas, and heated in a heating oven at 130 to 200° C. for 10 to 30 minutes to prepare a pattern. The thickness of the film prepared above was 2.0 μm.

The pattern of the polymer film coated with the photosensitive resin compositions of Examples 1 to 8 and Comparative Examples 1 to 2 prepared above was evaluated for bending characteristics (adhesion characteristics) using a bending tester (cyclic bending testet, Kobo Technology). .

Measurements were judged based on the number of patterns with no abnormalities based on 100 patterns based on 100,000 measurements.

The evaluation criteria are as follows, and the evaluation results are listed in Table 2 below.

<Evaluation criteria>

◎: Maintain more than 95 patterns

○: Maintain more than 90 but less than 95 patterns.

△: Maintain more than 60 but less than 90 patterns.

X: Maintain more than 9 but less than 60 patterns

division Banding evaluation Example 1 ◎ Example 2 ◎ Example 3 ◎ Example 4 ◎ Example 5 ○ Example 6 ○ Example 7 ○ Example 8 △ Comparative Example 1 X Comparative Example 2 X

From the results in Table 2, it was found that the photosensitive resin compositions for flexible substrates of Examples 1 to 8 of the present invention using solvents with a polarity of 3.5 to 8 had very excellent adhesion to the liquid crystal polymer film, which is a flexible substrate.

More specifically, the photosensitive resin compositions for flexible substrates of Examples 1 to 4 using only solvents with a polarity of 3.5 to 8 had very excellent adhesion to the liquid crystal polymer film, and the solvents with a polarity of 3.5 to 8 and other solvents had excellent adhesion to the liquid crystal polymer film. The photosensitive resin compositions for flexible substrates of Examples 5 to 8 mixed with a solvent also had excellent adhesion to the liquid crystal polymer film, but were not as good as those of Examples 1 to 4.

On the other hand, the photosensitive resin compositions of Comparative Examples 1 and 2 using solvents that did not correspond to the above polarity showed poor adhesion to the liquid crystal polymer film, which is a flexible substrate.

Accordingly, it was found that the photosensitive resin composition for flexible substrates using a solvent with a polarity of 3.5 to 8 of the present invention improves adhesion to the flexible substrate.

Experiment example 2. Measurement of solvent adhesion

0.1 g of silver nanoparticles were added to 100 g each of propylene glycol monomethyl ether acetate (solution 1) and N-methyl pyrrolidone (solution 2) having a polarity in the range of 3.5 to 8 and mixed.

Each of the above mixed solutions was applied to the polyimide substrate and left for 5 minutes. Then, the surface was wiped with a pure solution for 10 minutes and the surface of the polyimide substrate was observed.

On the polyimide substrate to which solution 2 was applied, a new peak that was not observed in the polyimide substrate to which solution 1 was applied was observed (Figure 1).

Additionally, as a result of observing the polyimide substrate onto which Solution 2 was applied, a silver (Ag) peak was observed, which can be seen as silver nanoparticles penetrating into the polyimide substrate.

That is, the solvent with a polarity of 3.5 to 8 has excellent adhesion to the polyimide substrate, which is a flexible substrate, into which the silver nanoparticles penetrate, and the solvent in Solution 1 has poor adhesion to the polyimide substrate, which is a flexible substrate, so the silver nanoparticles penetrate. It can be seen that penetration was not achieved.

Claims (12)

It contains an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator, and a solvent having a polarity of 3.5 to 8,
Solvents having a polarity of 3.5 to 8 include n-butylacetate, methyl isoamyl ketone, tetrahydrofuran, chloroform, methyl isobutyl ketone, ethyl acetate, methyl n-propyl ketone, methyl ethyl ketone, and 2-methoxyethanol. , a photosensitive resin composition for a flexible substrate, comprising at least one member selected from the group consisting of acetonitrile, propylene carbonate, formamide, pyridine, and dimethyl sulfone. delete delete delete The method of claim 1, wherein the total weight of the alkali-soluble resin is 5 to 15% by weight, the photopolymerizable compound is 5 to 15% by weight, the photopolymerization initiator is 0.01 to 10% by weight, and the total weight of the photosensitive resin composition is 100% by weight, based on the total weight of the photosensitive resin composition. A photosensitive resin composition for a flexible substrate, characterized in that it contains a residual amount of a solvent having a polarity of 3.5 to 8. The photosensitive resin composition for a flexible substrate according to claim 1, wherein the photosensitive resin composition further includes a solvent other than a solvent having a polarity of 3.5 to 8. The photosensitive resin composition for a flexible substrate according to claim 6, wherein the solvent having a polarity of 3.5 to 8 and the additional solvent are mixed at a weight ratio of 1:9 to 9:1. The photosensitive resin composition for a flexible substrate according to claim 1, wherein the photosensitive resin composition further includes a colorant. The photosensitive resin composition for a flexible substrate according to claim 1, wherein the photosensitive resin composition further includes an additive. The photosensitive resin composition for a flexible substrate according to claim 1, wherein the flexible substrate is at least one selected from the group consisting of polycarbonate, polyimide, acrylic, polyethylene terephthalate, polyether sulfide, liquid crystal polymer, and polysulfone. A color filter comprising the photosensitive resin composition for a flexible substrate of claim 1. A display device including the color filter of claim 11.

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