JP3055928B2 - Color filter image formation method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for forming a color image of a color filter, and particularly to a method suitable for use in a liquid crystal display panel and for manufacturing a color filter.

<Related Art> In recent years, color filters have been widely used in the field of liquid crystal color display devices. This color filter usually has blue (B), red (R) and green (G) as color elements, and arranges these dyes on the surface of a transparent substrate, for example, in a mosaic, stripe or triangle color element. It is made.

Currently, colored images used for these color filters are mainly produced by a dyeing method.

The dyeing method is to impart photosensitivity to soluble water-soluble polymers such as gelatin, fish glue, casein, and polyacrylamide by adding a dichromate or a water-soluble azide compound, and then exposing through a photomask. Then, after developing with water to obtain a relief pattern, the relief pattern is dyed to form a colored image. By repeating such a process three times,
It forms blue, red and green filters. And
Between the steps of each color, color mixing is prevented by, for example, performing an anti-dyeing treatment with tannic acid or providing an intermediate layer of a urethane resin or an acrylic resin.

By the way, such conventional dyeing methods involve complicated processes, difficult control of the dyeing bath, poor heat resistance of the dyeing medium (water-soluble polymer), poor heat resistance and poor weather resistance of the dye, and the like. There are drawbacks.

Therefore, in order to overcome the above drawbacks, recently, for example, color filters have been actively developed by a printing method, a pigment dispersion method, or the like.

This printing method is a method in which a colored image is formed by sequentially printing on a transparent substrate using an ink in which a pigment is dispersed in an organic vehicle. Although this printing method can perform film formation and patterning simultaneously, it is simple in process and excellent in cost and durability. However, new problems such as poor dimensional accuracy in which patterns can be fringed and poor surface smoothness are found. is there.

On the other hand, the pigment dispersion method is a method in which the above-mentioned problems are improved. In this method, a pigment is dispersed in a photosensitive resin,
A colored image is formed by coating, drying, exposing and developing on a transparent substrate, and has the advantage that a color filter colored image can be formed by a simple process as compared with the dyeing method. . Examples of the photosensitive resin used in the pigment dispersion method include stilbazolium-based pendant polyvinyl alcohol disclosed in JP-A-60-124736, JP-A-60-237403 and
Japanese Patent Application Laid-Open No. 1-152449, photosensitive polyimides and polyamides disclosed in JP-A-212603, photosensitive resins comprising an acrylic polymer and a bisdiazide compound disclosed in JP-A-1-200353, and the like. Various radical polymerization type photosensitive resins comprising a polyfunctional acrylate monomer, an organic polymer binder and a photopolymerization initiator have been proposed.

<Problem to be Solved by the Invention> However, the colored image forming method using a photosensitive resin according to the above-described pigment dispersion method has the following problems depending on the photosensitive resin used.

Stilbazolium-based pendant polyvinyl alcohol has a drawback of low heat resistance. To improve this, a stilbazolium-based pendant polyvinyl alcohol having a betaine structure disclosed in JP-A-2-160807 has been proposed, but the heat resistance is still insufficient.

Those using photosensitive polyimide or polyamide have high heat resistance, but have problems such as development with an organic solvent having low sensitivity in which the resin is colored.

A system using a bisazide compound as a photosensitive agent has problems such as being affected by oxygen at the time of low-sensitivity exposure.

A system using radical polymerization has high sensitivity, but has a problem that it is affected by oxygen during exposure.

Further, in order to avoid these effects, it is necessary to perform exposure in an inert gas atmosphere or to provide an oxygen barrier film, which leads to problems such as an increase in the cost of an apparatus or a complicated process. is there.

The present invention is highly sensitive in view of the circumstances described above,
Using a photosensitive colored resin composition having various characteristics such that the sensitivity does not change even under the influence of oxygen and development is aqueous, a pattern is sequentially formed, and a color filter for forming a color image of a color filter is formed. An object of the present invention is to provide a colored image forming method.

<Means for Solving the Problems> A method for forming a colored image of a color filter according to the present invention, which achieves the above object, comprises: (a) forming a resin containing phenol and a crosslinking agent having an N-methylol structure on a transparent substrate; A resin-based material curable by an acid, (b) a photoacid generator comprising either a halomethyl-S-triazine compound or a halomethyloxadiazole compound, and (c) a pigment. Coating and drying a photosensitive colored resin composition containing the photosensitive resin composition at a ratio of: a pattern exposure of the colored resin layer in an oxygen atmosphere; and an exposed colored resin layer. And a step of developing the exposed and heated colored resin layer with an alkali developer to form a colored image on the transparent substrate. It is characterized in that a colored image is formed.

 Hereinafter, the contents of the present invention will be described in detail.

The photosensitive colored resin layer composition used in the present invention,
A material containing (a) a resin-based material curable by an acid, (b) a photoacid generator, and (c) a pigment as essential components.

Here, the resin material curable by the acid (a) in the present invention includes, for example, a crosslinking agent having an N-methylol structure such as an amino resin such as a urea resin or a melamine resin and a phenolic hydroxyl group or a carboxyl group. Resin-based material with resin, resin-based material with epoxy resin and phenolic resin, or J.Photopolym.Sci.Technol.Vol.
3 No. 3 (1990) P235-247
Copolymers having a hydroxystyrene structure of hydroxystyrene and p-acetoxymethylstyrene can be exemplified, and those having a property of being cured by an acid.

In the above resin-based material, examples of the crosslinking agent having an N-methylol structure include methylolated urea, urea resin, methylolated melamine, methylolated guanamine,
Methylolated glyoxal diurein, methylolated uron, methylolated tetrahydropyrimidone derivative,
Methylolated triazones or their alkyl ethers can be mentioned. Among them, it is preferable to use an alkyl ether because of high storage stability.
The alkyl group of this alkyl ether has 1 carbon atom.
Particularly preferred are alkyl groups of 5 to 5.

In the resin-based material, as the resin having a phenolic hydroxyl group, for example, an alkali-soluble phenol resin, a novolak resin, a polymer having a hydroxystyrene structure, a polymer having a structure represented by the following general formula (I), Examples thereof include alkali-soluble polyimides having a phenolic hydroxyl group.

(Wherein, R ₁ represents a hydrogen, an alkyl group or an aryl group, R ₂ represents a hydrogen, a halogen, an alkyl group or an alkoxy group, and n represents an integer of 0 to 6). And a ketone in the presence of an acid catalyst. Phenols used at this time include, for example, phenol,
Cresol, ethylphenol, butylphenol, xylenol, phenylphenol, hydroquinone, catechol, resorcinol, pyrogallol, naphthol,
Bisphenol A and the like can be mentioned. These phenols are used alone or in combination of two or more. Examples of the ketones include formaldehyde, paraformaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, acetone, and methyl ethyl ketone.

In the above resin-based material, the polymer having a hydroxystyrene structure can be obtained, for example, by copolymerizing hydroxystyrene or α-methyl-hydroxystyrene alone, two or more kinds, or styrene or an acrylic monomer. Examples of the acrylic monomer as the copolymerization component include acrylic ester, methacrylic ester, acrylamide, methacrylamide, acrylonitrile, and the like.

Examples of the polymer containing the maleimide derivative structure represented by the above general formula (I) include, for example, JP-A-61-162039.
And Japanese Patent Application Laid-Open Nos. Sho 62-151408 and 62-151409.

As an alkali-soluble polyimide having a phenolic hydroxyl group, for example, J. Photopolym.Sci.Technol.Vol3N
o.3 (1990) pp. 275-280.

In the above resin-based material, the resin having a carboxyl group may be, for example, an unsaturated organic acid compound such as acrylic acid, methacrylic acid, or vinylbenzoic acid, and an unsaturated compound such as acrylic acid ester, methacrylic acid ester, or acrylonitrile. And the like.

In the resin-based material, examples of the epoxy resin include a novolak type epoxy resin, a bisphenol A type epoxy resin, a brominated bisphenol A type epoxy resin, and an alicyclic epoxy resin.

On the other hand, the photoacid generator (b) in the present invention refers to a compound that generates an acid upon irradiation with light, and many known compounds and mixtures thereof may be used. ^{_{-, BF 4 -, PF 6}} -, AsF 6 -, SbF 6 -, SiF 6 -, ClO 4
^-, CF ₃ SO ₄ ^- salts such as; (ii) organic halogen compounds; (ii
i) naphthoquinonediazidesulfonic acid compound and (iv)
Light sulfonic acid generating compounds and the like are suitable.

More specifically, (i) examples of ammonium salts as onium salts are described in U.S. Pat. Nos. 4,069,055 and 4,069,056; examples of diazonium salts include Photogr. Sci. Eng., 18 , 387 (1974), J.Macrom
ol.Sci., Chem., A 21 , 1695 (1984), and Polymer. 21, 423
(1980); Examples of iodonium salts include Macromol
ecules, 10 , 1307 (1977). Chem., & Eng. News, Nov. 28, P3
1 (1988), and EP 0,104,143; examples of sulfonium salts include Polymer J., 17 , 73.
(1985), Polymer Bull., 14 , 279 (1985), J. Polymer Sc
i., 17 , 977 (1979), J. Org. Chem., 43 , 3055 (1978).
g. Chem., 50 , 4360 (1985), JP-A-57-18723, JP-A-56-8428, U.S. Patent No. 4,760,013, U.S. Patent No. 4,139,655, U.S. Patent No. 4,734,444 And EP 0297,433; examples of phosphonium salts include US Pat. Nos. 4,069,055,
4,069,056 and Macromolecules, 17 , 2469 (1984)
Examples of selenonium salts include Macromolecules, 10 ,
1307 (1977) and J. Polymer Sci., Polymer Chem. Ed., 1
7, 1047 (1979); examples of arsonium salts include Pr.
oc. Conf. Rad. Curing ASIA p478 Tokyo. Oct. (1988).

Examples of (ii) organic halogen compounds capable of generating an acid upon irradiation with light include carbon tetrabromide, iodoform, tribromoacetophenone, a phenyltrihalomethylsulfone compound described in JP-B-46-4605, and the like. JP-B-48-36281, JP-A-53-133428, JP-A-Sho-6
No. 0-105667, JP-A-60-239736, halomethyl-S-triazine compounds, Angew. Physik.
24, 381 (1918) .J.Phys.Chem. , 66 .2449 (1962), JP 54-74728, JP-Sho 55-77742, JP-Sho 59
JP-148784, JP-A-60-3626, JP-A-60-13
And halomethyloxadiazole compounds described in JP-A-8539 and JP-A-60-239473.

(Iii) Examples of the naphthoquinonediazide compound include 1,2-naphthoquinone- (2) -diazido-4-sulfonyl chloride.

(Iv) Examples of the photosulfonic acid generating compound include 1,2
-Naphthoquinone- (2) -diazide-4-sulfonic acid ester or amide compound, Polymer Preprints. Ja
β-ketosulfone compounds described in Pan 35 , 2406 (1986), Macromolecules. 21 , 2001 (1988), JP-A 64-1814.
No. 3, an ester compound of nitrobenzyl alcohol and an arylsulfonic acid, described in European Patent No. 0,04
No. 4,155, an ester compound of an oxime and an arylsulfonic acid described in No. 0,199,672, U.S. Pat.
No. 8,121, No. 4,371,605, ester compounds of N-hydroxyamide or imide and sulfonic acid described in No. 4,618,564, European Patent No. 84515, benzoin and sulfone described in No. 199,672. Examples thereof include an ester compound with an acid.

Among these photoacid generators, the organic halogen compound (ii), particularly the halomethyl-S-triazine compound, the halomethyloxadiazole compound and the photosulfonic acid generating compound (iv) are preferred because of their good crosslinking efficiency.

These photoacid generators may be used alone or as a mixture. The amount of the photoacid generator is 0.1 to 50% by weight based on the solid content of the resin-based material curable by the acid (a). Preferably, it is 0.5 to 30% by weight. This is 0.1
If the amount is less than 50% by weight, the amount of generated acid is so small that a crosslinking reaction hardly occurs. Also, if the amount exceeds 50% by weight, a further effect of increasing the amount cannot be expected, and the developability deteriorates, and both are not preferred.

The photoacid generator can be used in combination with a sensitizer for increasing the acid generation efficiency as required.

Known sensitizers can be used as such a sensitizer,
For example, anthracene, phenanthrene, perylene, pyrene, chrysene, 1,2-benzoanthracene, coronene, 1,6-diphenyl-1,3,5-hexatriene, 1,1,4,
4-tetraphenyl-1,3-butadiene, 2,3,4,5-tetraphenylfuran, 2,5-diphenylthiophene, thioxanthone, 2-chlorothioxanthone, phenothiazine, 1,3-diphenylpyrazoline, 1,3 -Diphenylisobenzofuran, xanthone, benzophenone, 4-hydroxybenzophenone, anthrone, ninhydrin, 9
-Fluorenone, nitropyrene, 2,4,7-trinitrofluorenone, indanone, phenanthraquinone, tetralone, 7-methoxy-4-methylcoumarin, 3-keto-
Bis (7-diethylaminocoumarin), fluorocene,
Sensitizers such as eosin, rhodamine S and triphenylpyrylium perchlorate can be mentioned.

The molar ratio of these sensitizers to the photoacid generator (b) is 0.01 / 1 to 10/1, preferably 0.1 / 1 to 5/1.
/ 1.

The sensitivity of the composition of the present invention can be enhanced by selecting the type of such a sensitizer according to the pigment used.

The pigment (c) in the present invention means a colored powder that is hardly soluble in water or an organic solvent, and is preferably one having excellent heat resistance, light resistance and solvent resistance. Such pigments include, for example, azo, anthraquinone, isoindolinone, indigo, indathrone, xanthene, quinacridone, quinophthalone, dioxazine, thioindigo, pyranthrone, phthalocyanine, perinone, perylene-based pigments. , Benzoindazolone-based organic pigments and inorganic pigments such as Miroli blue, ultramarine blue, cobalt blue, emerald green, carbon, titanium carbon, iron oxide, and the like. Can be

When the above pigment is used for a color filter or the like,
From the viewpoints of light transmittance, uniformity of the formed film, and the like, the particle size is preferably 1 μm or less.

The weight ratio of the following formula (1) in the present invention is: 95/5 to 10/90, preferably 90/10 to 40/60. This is because when the weight ratio is less than 95/5, the film thickness for obtaining a desired color density becomes too thick, and
If the ratio exceeds / 90, the dispersion stability of the pigment and the ability to form a film are impaired, which are both undesirable.

In the photosensitive colored resin composition of the present invention, the component (a) of the resin-based material curable by the acid and the component (b) of the photoacid generator are dissolved in a solvent capable of dissolving, and the pigment is dispersed. It is used as a solution that has been made to fall.

Examples of such solvents include dioxane, diethoxyethane, diethylene glycol dimethyl ether, methyl cellosolve, ethyl cellosolve, ethylene glycol monoisopropyl ether, propylene glycol monomethyl ether, ethers such as propylene glycol monoethyl ether, acetone, methyl ethyl ketone, methyl Ketones such as isobutyl ketone, cyclopentanone, cyclohexanone, ethyl acetate, butyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, dimethyl oxalate, methyl lactate, ethyl lactate Esters, such as N, N-dimethylformamide, N, N-dimethylacetamide, etc. S, pyrrolidones such as N- methylpyrrolidone, lactones such as γ- butyrolactone, and the like sulfoxides such as dimethyl sulfoxide. These solvents may be used alone or in combination of two or more.
And the concentration in the above components (total solids including additives)
It is suitably from 2 to 70% by weight, more preferably from 5 to 50% by weight.

In the photosensitive colored resin composition of the present invention, if necessary, the viscosity of the composition is adjusted, the dispersion stability of the pigment is improved, the coating property is improved, the adhesion of the coating film to the substrate is improved, and the coating film is flattened. Other additives can be added for the purpose of improving the developing property and the developing characteristics.

As a transparent substrate for applying the photosensitive resin composition,
For example, a glass plate, a plastic plate or a plastic film can be used.

An example of a method for forming a colored image using the photosensitive colored resin composition described above will be described.

In the method for forming a colored image of a color filter according to the present invention, the photosensitive colored resin composition having the above configuration is applied on the transparent substrate and dried to form a colored resin layer, and then irradiated with light according to a predetermined pattern. The layer is heated in the range of about 50 to 200 ° C., and then developed with a developer to form a colored image on a transparent substrate. Thus, a colored image of a color filter of a plurality of colors such as blue (B), red (R), and green (G) is formed.

As the above-mentioned coating method, conventionally known methods, for example, spin coating, wire bar coating, dip coating, air knife coating, roll coating, blade coating, curtain coating,
Screen printing application and the like can be mentioned.

The drying when forming the above colored resin layer is about
It is about 30 seconds to 30 minutes at 50 to 150 ° C.

Can be used, for example, visible light, ultraviolet light, X-rays, and electron beams.

Next is a heat treatment for heating the resin layer,
The heat treatment after the exposure crosslinks and cures the resin in the exposed portion so that it does not dissolve in the developer. This heat treatment is carried out at a temperature in the range of about 50 to 200 ° C, preferably 70 to 160 ° C.

Examples of the developer include alkaline aqueous solutions such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium metasilicate, potassium metasilicate, dibasic sodium phosphate, tribasic sodium phosphate, and ammonia. Alkylamines such as alkali, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine and methyldiethylamine; alcoholamines such as diethanolamine and triethanolamine; tetramethylammonium hydroxide; tetraethylammonium hydroxide; An aqueous solution of a quaternary ammonium salt such as trimethyl (2-hydroxyethyl) ammonium hydroxide or a cyclic amine such as pyrrole or piperidine can be used.

If necessary, other additives such as a surfactant, a wetting agent, a stabilizer and a small amount of an organic solvent can be added to the developer.

The first pattern is formed by developing using the developing solution as described above. Next, in the space between the first patterns, the second and third patterns are sequentially formed by repeating the above-described series of steps to obtain a BRG color filter colored image.

It should be noted that the provision of a light-shielding film between the colors of the colored image does not affect the colored image forming method of the present invention.

<Example> Next, the present invention will be described in more detail with reference to an example.

Example 1 A resin-based material curable by an acid (a) having the following composition 1 and a photoacid generator (b) were dissolved in a solvent.
Using a photosensitive colored resin composition consisting of
The film was applied to a soda glass substrate on which an O ₂ film was formed by a spinner so as to have a film thickness of 1 μm, and dried at 80 ° C. for 10 minutes.

The colored photosensitive resin layer was exposed to an air atmosphere with a metal halide lamp through a mask having a predetermined shape.

Subsequently, the colored photosensitive resin layer subjected to pattern exposure was
Heated in oven at 0 ° C. for 10 minutes. Thereafter, development was performed with a 2.38% aqueous solution of tetramethylammonium hydroxide to obtain a colored pattern.

The coloring pattern thus obtained is uniform,
No thickness unevenness was observed, and the edge was sharp.

Example 2 A photosensitive colored resin composition of the following composition 2 was applied on a glass substrate on which the colored pattern obtained in Example 1 was formed by a spinner, and dried at 90 ° C. for 10 minutes.

After exposing with a metal halide lamp through a photomask, it was heated in an oven at 140 ° C. for 10 minutes.

Subsequently, as a result of development with a 2.38% aqueous solution of tetramethylammonium hydroxide, R and G colored images were formed.

Example 3 A photosensitive colored resin composition of the following composition 3 was applied on a glass substrate on which a colored pattern obtained in Example 2 was formed by a spinner and dried at 80 ° C. for 10 minutes.

After exposing with a metal halide lamp through a photomask, it was heated in an oven at 140 ° C. for 10 minutes.

Subsequently, development with a 2.38% aqueous solution of tetramethylammonium hydroxide revealed that RGB color development was formed.

The pattern of each color element of the obtained colored image was uniform and clear, and the color density and hue were sufficiently satisfactory.

Further, even when the colored image was heated at 230 ° C. for 1 hour, its spectral transmission characteristics hardly changed.

<Effects of the Invention> As described in detail with the examples above, according to the method of the present invention, it has high sensitivity, is not affected by oxygen at the time of exposure, has excellent heat resistance, and can be used in an aqueous developer. By repeating a series of image forming steps using a developable photosensitive coloring composition, a colored image of a color filter having good heat resistance without color unevenness can be easily formed in a simple step.

Therefore, according to the method of the present invention, a high-quality and high-reliability liquid crystal color display, a liquid crystal color television, a color image sensor, and the like can be easily manufactured.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hideo Kikuchi 563 Yonegasaki-cho, Funabashi-shi, Chiba Pref. Photographic Materials Research Laboratories, Toyo Kasei Kogyo Co., Ltd. (56) References JP-A-1-80905 (JP, A) JP-A-61-180202 (JP, A) JP-A-60-263143 (JP, A) JP-A-62-164045 (JP, A) JP-A-2-38411 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) G02B 5/20 101 G02F 1/1335 505

Claims (1)

(57) [Claims] 1. A resin material curable by an acid comprising a resin containing phenol and a crosslinking agent having an N-methylol structure, and (b) a halomethyl-S-triazine compound or halo. A photoacid generator comprising any one of a methyloxadiazole compound; and (c) a pigment. Coating and drying a photosensitive colored resin composition containing the photosensitive resin composition at a ratio of: a pattern exposure of the colored resin layer in an oxygen atmosphere; and an exposed colored resin layer. And a step of developing the exposed and heated colored resin layer with an alkali developer to form a colored image on the transparent substrate. A method for forming a colored image of a color filter, comprising forming a colored image of a color.