KR20030057103A - Photosensitive resin composition for color filter - Google Patents

Abstract

PURPOSE: Provided is a photosensitive resin composition for color filter, which retains excellent chemical resistance and processability of pattern, as well as improved film strength. CONSTITUTION: The composition comprises (1) 0.5-20 wt% of carboxyl group-containing acrylic binder resin, (2) 0.5-20 wt% of epoxy novolac acrylic carboxylate resin, (3) 0.5-20 wt% of photopolymerizable acrylic monomer, (4) 0.1-10 wt% of photopolymerization initiator, (5) 0.1-40 wt% of pigment, and (6) 20-90 wt% of solvent. The epoxy novolac acrylic carboxylate resin has a structure of formula 1, and a molecular weight of 3,000-30,000. In the formula 1, R represents an alkyl group of C1-C12.

Description

Photosensitive resin composition for color filters {PHOTOSENSITIVE RESIN COMPOSITION FOR COLOR FILTER}

The present invention relates to an alkali aqueous developing photosensitive resin composition used in a color filter, and more particularly, a color containing high hardenability and alkali-soluble epoxy novolac acrylic carboxylate resin to express excellent chemical resistance and process characteristics. It relates to a photosensitive resin composition for filters.

The color filter is used in a liquid crystal display device, an optical filter of a camera, and the like, and is manufactured by coating a fine region colored with three or more colors on a solid state imaging device or a transparent substrate. Such colored thin films are usually formed by dyeing, printing, electrodeposition, pigment dispersion, or the like.

In the dyeing method, an image having a dye-based base material such as natural photosensitive resin such as gelatin, amine-modified polyvinyl alcohol, amine-modified acrylic resin, etc. is formed on a substrate in advance and then dyed with a dye such as a direct dye to form a colored thin film. In order to form a multi-colored thin film on the same substrate, it is necessary to perform flameproof processing every time the color is changed, so that the process is very complicated and the time is delayed. In addition, the clarity and dispersibility of the commonly used dyes and resins themselves are good, but there are disadvantages in that light resistance, moisture resistance and heat resistance, which are the most important characteristics, are poor. For example, although Korean Patent Publication No. 91-4717 and Korean Patent Publication No. 94-7778 use azo compounds and azide compounds as dyes, they have disadvantages in that heat resistance and durability are inferior to pigment type.

In the printing method, printing is performed using the ink which disperse | distributed the pigment to thermosetting or photocurable resin, and a colored thin film is formed by hardening with heat or light. According to this method, the material cost can be reduced compared to other methods, but it is difficult to form highly precise and detailed images, and the thin film layer formed is not uniform. Republic of Korea Patent Publication No. 95-703746 and Republic of Korea Patent Publication No. 96-11513 propose a method of manufacturing a color filter using the inkjet method, the color resist sheet composition sprayed from the nozzle for the printing of a delicate and accurate pigment Since it is a mold, durability and heat resistance are inferior as in the dyeing method.

In contrast, Korean Patent Publication No. 93-700858, Korean Patent Publication No. 96-29904, and Korean Patent Publication No. 96-29904 propose an electrodeposition method using an electroprecipitation method. It can be formed, and because it uses a pigment, it has excellent heat resistance and light resistance, but when the pixel size is precise and the electrode pattern becomes fine in the future, colored stains due to electrical resistance appear on both ends or the thickness of the colored film becomes thick, It is difficult to apply to color filters that require a high degree of precision.

On the other hand, the pigment dispersion method is a method in which a colored thin film is formed by repeating a series of processes of coating-exposure-developing-thermosetting a photopolymerizable composition containing a colorant on a transparent substrate provided with a black matrix. The pigment dispersion method has the advantage of improving heat resistance and durability, which are the most important properties of the color filter, and maintaining the thickness of the film uniformly. For example, Korean Patent Publication No. 92-702502, Korean Patent Publication No. 94-5617, Korean Patent Publication No. 95-11163, Korean Patent Publication No. 95-700359, and the like, propose a method for producing a color resist using pigment dispersion. have.

The colored photosensitive resin composition used for manufacturing the color filter by the pigment dispersion method generally consists of a binder resin, a photopolymerizable monomer, a photoinitiator, an epoxy resin, a solvent, other additives, etc. As the binder resin, for example, Japanese Patent Laid-Open Nos. Hei 7-140654 and Hei 10-254133 use a carboxyl group-containing acrylic copolymer.

However, in recent years, the direction of color filter development requires high color reproducibility and high brightness, which leads to high concentration and fineness of pigment. As a result, the content of the acrylic binder resin which does not have reactivity itself is reduced, thereby not being able to maintain sufficient film strength, as well as reducing the sensitivity due to the increase of the pigment content, lowering the chemical resistance, and the like. The use of non-reactive acrylic binder resin has become difficult. As an alternative to this, Japanese Patent Laid-Open No. 2000-154207 has proposed a method of imparting reactivity to an acrylic binder resin.

The present invention is to solve the problems of the prior art as described above, excellent curing performance in the photosensitive resin composition for color filters using a carboxyl group-containing acrylic copolymer having good miscibility with the pigment dispersion as a binder resin, By introducing an epoxy novolac acrylic carboxylate resin having developability, an object thereof is to improve film strength while maintaining excellent chemical resistance and process characteristics of a pattern.

That is, the present invention provides a photosensitive resin composition for color filters comprising the following components:

(1) 0.5 to 20% by weight of carboxyl group-containing acrylic binder resin;

(2) 0.5 to 20% by weight epoxy novolac acrylic carboxylate resin;

(3) 0.5 to 20% by weight of an acrylic photopolymerizable monomer;

(4) 0.1 to 10% by weight of photopolymerization initiator;

(5) 0.1 to 40% by weight of pigment; And

(6) 20-90 weight% of solvents.

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

The carboxyl group-containing acrylic binder resin (component 1) used in the present invention is a copolymer of an ethylenically unsaturated monomer having one or more carboxyl groups and other ethylenically unsaturated monomers copolymerizable therewith. At this time, the weight ratio of the carboxyl group-containing ethylenically unsaturated monomer is in the range of 5 to 50%, preferably 10 to 40% of the total copolymer. The molecular weight (Mw) of the carboxyl group-containing acrylic binder resin is 3,000 to 150,000, preferably 5,000 to 50,000.

Examples of the carboxyl group-containing ethylenically unsaturated monomers include acrylic acid, methacrylic acid, maleic acid, itaconic acid, and fumaric acid, and the carboxyl group-containing acrylic binder resin used in the present invention includes at least one monomer thereof. do. As another ethylenically unsaturated monomer copolymerizable with the said carboxyl group-containing ethylenically unsaturated monomer, For example, styrene, (alpha) -methyl styrene, vinyltoluene, vinyl benzyl methyl ether, methyl acrylate, methyl methacrylate, ethyl acrylate, Ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-hydroxy ethyl acrylate, 2-hydroxy ethyl methacrylate, 2-hydroxy butyl acrylate, 2-hydroxy butyl methacrylate, benzyl acryl Unsaturated carboxylic acid esters such as latex, benzyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, phenyl acrylate and phenyl methacrylate; Unsaturated carboxylic acid amino alkyl esters such as 2-amino ethyl acrylate, 2-amino ethyl methacrylate, 2-dimethyl amino ethyl acrylate and 2-dimethyl amino ethyl methacrylate; Carboxylic acid vinyl esters such as vinyl acetate and vinyl benzoate; Unsaturated carboxylic acid glycidyl esters such as glycidyl acrylate and glycidyl methacrylate; Vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; Unsaturated amides such as acryl amide and methacryl amide, and the like, and the carboxyl group-containing acrylic binder resin used in the present invention contains at least one of these monomers.

Specific examples of the carboxyl group-containing acrylic binder resin composed of such monomers include methacrylic acid / benzyl methacrylate copolymer, methacrylic acid / benzyl methacrylate / styrene copolymer, methacrylic acid / benzyl methacryl Late / 2-hydroxy ethyl methacrylate copolymer, methacrylic acid / benzyl methacrylate / styrene / 2-hydroxy ethyl methacrylate copolymer, and the like.

It is preferable that the usage-amount of the said component (1) is 0.5-20 weight% with respect to the whole composition. If the content of component (1) is less than 0.5% by weight, a problem occurs in which the developer is not developed in the alkaline developer, while in excess of 20% by weight, there is a disadvantage in that the surface roughness is increased due to the lack of crosslinkability.

In the present invention, the epoxy novolac acrylic carboxylate resin (component 2) used for the purpose of improving the chemical resistance and curing property of the pattern is a resin having the structure of the following Chemical Formula 1, and preferably has a molecular weight of 3,000 to 30,000. This resin is excellent in curing performance and soluble in an alkaline developer.

In the formula, R represents an alkyl group having 1 to 12 carbon atoms.

It is preferable that the usage-amount of the said component (2) is 0.5-20 weight% with respect to the whole composition. If the content of component (2) is less than 0.5% by weight, the object of the present invention may not be achieved, whereas if it is more than 20% by weight, the formation of a pattern may be impossible.

The acrylic photopolymerizable monomer (component 3) used in the present invention is a monomer generally used in the photosensitive resin composition for color filters, for example, ethylene glycol diacrylate, triethylene glycol diacrylate, 1,4-butanediol di Acrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, dipentaerythritol diacrylate, dipentaerythritol triacrylate, Dipentaerythritol pentaacrylate, pentaerythritol hexaacrylate, bisphenol A diacrylate, trimethylolpropane triacrylate, novolac epoxy acrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, tri Ethylene Glycol Dimethacrylate, Propylene Glycol Dimethacrylate, 1,4-Butanedi Old dimethacrylate, 1,6-hexanediol dimethacrylate, and the like.

It is preferable that the usage-amount of the said component (3) is 0.5-20 weight% with respect to the whole composition. If the content of component (3) is less than 0.5% by weight, the corners of the pattern will not be formed cleanly, while if the content of component (3) is more than 20% by weight, the problem will not develop in the alkaline developer.

The photoinitiator (component 4) used in this invention is a photoinitiator generally used for the photosensitive resin composition, For example, an acetophenone type compound, a benzophenone type compound, a thioxanthone type compound, a benzoin type compound, a triazine type compound Etc. can be used.

It is preferable that the usage-amount of the said component (4) is 0.1-10 weight% with respect to the whole composition. If the content of component (4) is less than 0.1% by weight, photopolymerization does not sufficiently occur during exposure in the pattern forming process, whereas if it exceeds 10% by weight, the unreacted initiator remaining after photopolymerization has a disadvantage in decreasing transmittance.

Specific examples of the acetophenone-based compound used as the photopolymerization initiator include 2,2'-diethoxyacetophenone, 2,2'-dibutoxyacetophenone, 2-hydroxy-2-methylproriophenone, and pt-butyl Trichloroacetophenone, pt-butyldichloroacetophenone, benzophenone, 4-chloroacetophenone, 4,4'-dimethylaminobenzophenone, 4,4'-dichlorobenzophenone, 3,3'-dimethyl-2-meth Methoxybenzophenone, 2,2'-dichloro-4-phenoxyacetophenone, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropan-1-one, 2-benzyl-2 -Dimethylamino-1- (4-morpholinophenyl) -butan-1-one and the like.

As the benzophenone compound, benzophenone, benzoyl benzoic acid, benzoyl benzoic acid methyl, 4-phenyl benzophenone, hydroxy benzophenone, acrylated benzophenone, 4,4'-bis (dimethyl amino) benzophenone, 4,4'-bis (Diethyl amino) benzophenone and the like.

Examples of thioxanthone compounds include thioxanthone, 2-chloro thioxanthone, 2-methyl thioxanthone, isopropyl thioxanthone, 2,4-diethyl thioxanthone, and 2,4-diisopropyl thioke Acid, 2-chloro thioxanthone, and the like.

Benzoin-based compounds include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyldimethyl ketal and the like.

Triazine compounds include 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 (trichloromethyl) -s-triazine, 2- (p-tril) -4,6-bis (trichloromethyl) -s-triazine, 2- Fiphenyl-4,6-bis (trichloromethyl) -s-triazine, bis (trichlorobetayl) -6-styryl-s-triazine, 2- (naphtho 1-yl) -4,6- Bis (trichloro methyl) -s-triazine, 2- (4-methoxy naphtho 1-yl) -4,6-bis (trichloro methyl) -s-triazine, 2-4-trichloro methyl ( Piperonyl) -6-triazine, 2-4-trichloro methyl (4'-methoxy styryl) -6-triazine and the like.

In addition, carbazole compounds, diketone compounds, sulfonium borate compounds, diazo compounds, biimidazole compounds, and the like can also be used.

In the present invention, as the pigment (component 5), inorganic pigments such as carbon black may be used in addition to organic pigments such as anthraquinone pigments, condensed polycyclic pigments, phthalocyanine pigments, and azo pigments. May be used alone or in combination of two or more thereof.

It is preferable that the usage-amount of the said component (5) is 0.1-40 weight% with respect to the whole composition. If the content of component (5) is less than 0.1% by weight, the coloring effect is insignificant, while if it is more than 40% by weight, the developing performance is sharply lowered.

In the present invention, a dispersant may be used as necessary to uniformly disperse the pigment component in the solvent, and for this purpose, both nonionic, anionic or cationic dispersants may be used, for example, polyalkylene glycol and esters thereof, Polyoxyalkylenes, polyhydric alcohol ester alkylene oxide adducts, alcohol alkylene oxide adducts, sulfonic acid esters, sulfonates, carboxylic acid esters, carboxylates, alkylamide alkylene oxide adducts, alkylamines and the like can be used. These dispersants can be used individually by 1 type or in combination of 2 or more types as appropriate.

Solvents (component 6) usable in the present invention include ethylene glycol acetate, ethyl cellosolve, propylene glycol methyl ether acetate, ethyl lactate, polyethylene glycol, cyclohexanone, propylene glycol methyl ether and the like. May be used alone or in combination of two or more thereof.

It is preferable that the usage-amount of the said component (6) is 20 to 90 weight% with respect to the whole composition. If the content of component (6) is less than 20% by weight, application of the resin composition is difficult, and if it exceeds 90% by weight, it is difficult to maintain flatness in a film having a thickness of 3 µm or more.

The photosensitive resin composition of this invention is apply | coated in thickness of 0.5-10 micrometers, for example using suitable methods, such as spin coating, roller coating, and spray coating, on the glass substrate for color filters. After application, the active line is irradiated to form a pattern required for the color filter. As a light source used for irradiation, UV ray of 190-450 nm, Preferably 200-400 nm area | region is irradiated, for example, electron beam and X-ray irradiation are also suitable. After irradiating the light, the coating layer is treated with an alkaline developer, so that the unilluminated portion of the coating layer is dissolved and a pattern necessary for the color filter is formed. By repeating this process in accordance with the required number of colors, a color filter having a desired pattern can be obtained. Further, in the above process, crack resistance, solvent resistance, and the like can be further improved by heating the image pattern obtained by development again or curing by active ray irradiation or the like.

Hereinafter, the present invention will be described in more detail with reference to examples, but these examples are for illustrative purposes only and should not be construed as limiting the present invention.

Example 1

(1) Carboxyl group-containing acrylic binder resin 6.45 g

(A ') / (B') = 30/70 (w / w), molecular weight (Mw) = 25,000

(A '): methacrylic acid

(B '): benzyl methacrylate

(2) 0.7 g of epoxy novolac acrylic carboxylate resin

In Formula 1, R is CH ₂ , the molecular weight of 5,000 resin

(3) acrylic photopolymerizable monomer

5.5 g of dipentaerythritol hexaacrylate

(4) photopolymerization initiator

TAZ-110 (made by Midori Kagaku Corporation) 0.5 g

Igacure 907 (Shiba-Gaigi Co., Ltd.) 0.2g

4,4'-bis (diethylamino) benzophenone (manufactured by Hodogaya Corporation) 0.6 g

(5) pigment

Diketo-Pyrrollo-Pyrole Red 6g

(6) solvent

Propylene Glycol Monomethyl Ether Acetate 65g

15 g of cyclohexanone

(7) dispersant

Fluorinated Dispersant (FC-430, 3M) 0.05g

Using the above components, a photosensitive resin composition was prepared as follows:

(1) After dissolving a photoinitiator in a solvent, it stirred at room temperature for 2 hours.

(2) Carboxyl group-containing acrylic binder resin, epoxy novolac acrylic carboxylate resin, and photopolymerizable monomer were added and stirred at room temperature for 2 hours.

(3) The pigment was added and stirred at room temperature for 1 hour.

(4) A dispersant was added and stirred at room temperature for 1 hour.

(5) Three times of filtration was performed to remove impurities.

Example 2

A photosensitive resin composition was prepared in the same manner as in Example 1, except that the amounts of the carboxyl group-containing acrylic binder resin and the epoxy novolac acrylic carboxylate resin were adjusted to 4.9 g and 2.1 g, respectively.

Example 3

The photosensitive resin composition was manufactured in the same manner as in Example 1, except that the amount of the carboxyl group-containing acrylic binder resin and the epoxy novolac acrylic carboxylate resin was adjusted to 3.5 g each.

Comparative Example 1

A photosensitive resin composition was prepared in the same manner as in Example 1, except that an epoxy novolac acrylic carboxylate resin was not used and only 7 g of a carboxyl group-containing acrylic binder resin was used instead.

Characterization of the pattern formed using the photosensitive colored resin composition prepared in Examples 1 to 3 and Comparative Example 1 was performed as follows:

-Chemical resistance

The photosensitive resin composition was applied to a thickness of 1 to 2 μm on a 0.7 mm thick glass substrate washed with degreasing, and dried in a hot air circulation drying furnace at 80 ° C. for 1 minute to obtain a coating film. Subsequently, irradiated with an ultra-high pressure mercury lamp having a wavelength of 365 nm, developing at 30 ° C. and atmospheric pressure for 60 seconds using a 1% KOH-based aqueous solution, and then drying at 220 ° C. for 40 minutes in a hot air circulation drying furnace. A pattern was obtained. Each of these patterns was prepared for each Example and 5 Comparative Examples, each pattern was immersed in 5% HCl aqueous solution, 5% NaOH aqueous solution, N-methylpyrrolidone (NMP), xylene or IPA (isopropyl alcohol) for 60 minutes After the drying, the pattern change and the color difference were observed. If any of the five solutions did not pass, it was determined to be defective.

○: No change in pattern, color difference (ΔE) is 3.0 or less

(Triangle | delta): There is little change of a pattern, or color difference ((DELTA) E) is 3.0-5.0

X: many pattern changes or color difference ((DELTA) E) is 5.0 or more

(※ change of pattern: swelling, peeling, melting of pattern)

Developability

Applying the photosensitive resin composition to a thickness of 1 ~ 2μm on a 1mm thick chromium coated glass substrate degreased, and after the EBR (Edge Bead Remover) treatment, dried for 1 minute at 80 ℃ in a hot air circulation drying furnace to obtain a coating film It was. Subsequently, a photomask was placed on the coating film and exposed using a high-pressure mercury lamp having a wavelength of 365 nm, followed by developing at 30 ° C. and atmospheric pressure for 60 seconds using a 1% KOH-based aqueous solution, followed by hot air circulation drying. Dry at 220 ° C. for 40 minutes to obtain a pattern. Then, the presence or absence of the residue was visually examined under a halogen lamp.

○: Excellent processability-No residue or EBR residue on the pattern.

(Triangle | delta): Good processability-There exist some residue and EBR residue on a pattern.

X: poor processability-Many residues remain on the pattern.

Pattern surface roughness

The photosensitive resin composition was applied to a thickness of 1 to 2 μm on a 1 mm thick chromium-coated glass substrate, and dried for 1 minute at 80 ° C. in a hot air circulation drying furnace to obtain a coating film. Subsequently, a photomask was placed on the coating film and exposed using a high-pressure mercury lamp having a wavelength of 365 nm, and then developed at 30 ° C. and 1 atmosphere using a 1% KOH-based aqueous solution, followed by hot air circulation drying. Drying in the furnace at 220 ° C. for 40 minutes yielded a pattern. Then, the shape of the pattern of 100μm size was observed using P-10 manufactured by TENCO.

○: roughness of pattern surface is less than 40Å

Δ: roughness of the surface of the pattern is 40 kPa to 80 kPa

×: roughness of pattern surface is 80Å or more

The results according to the above evaluation method are shown in Table 1 below.

Chemical resistance Developability Surface roughness Example 1 △ ○ △ Example 2 ○ ○ ○ Example 3 ○ △ ○ Comparative Example 1 × ○ △

As described in detail above, the photosensitive resin composition of the present invention is excellent in chemical resistance, curability, and process characteristics, and when the resin composition of the present invention is used, a high quality color filter can be produced.

Claims (3)

Photosensitive resin composition for color filters comprising the following components: (1) 0.5 to 20% by weight of carboxyl group-containing acrylic binder resin; (2) 0.5 to 20% by weight epoxy novolac acrylic carboxylate resin; (3) 0.5 to 20% by weight of an acrylic photopolymerizable monomer; (4) 0.1 to 10% by weight of photopolymerization initiator; (5) 0.1 to 40% by weight of pigment; And (6) 20-90 weight% of solvents. The photosensitive resin composition for color filters according to claim 1, wherein the epoxy novolac acrylic carboxylate resin has a structure represented by the following Chemical Formula 1, and has a molecular weight of 3,000 to 30,000. [Formula 1] In the formula, R represents an alkyl group having 1 to 12 carbon atoms. The color filter manufactured by forming a pattern from the photosensitive resin composition of Claim 1 or 2.