JPH0834876A - Photosensitive resin composition - Google Patents

Abstract

PURPOSE:To reduce the transmittance by incorporating an electrolyte into a pseudo-black photosensitive resin composition. CONSTITUTION:In a ball mill, a dispersant comprising a surfactant such as a polyoxyethylene alkylphenyl ether is mixed with water and then with each pigment in a specific amount to form a dispersion, thus producing each coloring composition. At least two of the black, red, green, purple and yellow coloring compositions are mixed at a specific ratio to form a pseudo-black composition. The pseudo-black composition is then mixed with a binder resin, such as an arylic resin or polyacrylamide, and a photo-crosslinking agent comprising, e.g. p-diazophenylamine in an amount of about 1-30wt.% based on the binder resin to produce a pseudo-black photosensitive resin composition. This composition is mixed with at most about 10wt.%, especially pref. about 0.05-2wt.%, electrolyte such as NaCl to provide a pseudo-black photosensitive resin composition reduced in transmittance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a pseudo blackening photosensitive resin composition used for producing a color filter, and more particularly,
The present invention relates to a pseudo-blackening photosensitive resin composition for producing a black matrix.

[0002]

2. Description of the Related Art A color resist in which a pigment is dispersed in a photosensitive resin composition (resist) is disclosed in JP-A-4-63870.
There is one described in the publication. This is obtained by coating a resist on a transparent substrate by a method such as a spin coater in the same manner as an ordinary colored color resist, and then forming a pattern using the photolithography method, that is,
It is a color resist type black matrix.

Since the color resist type black matrix has a light-shielding property, when a pattern is formed by the photolithography method, the amount of light at the photoreactive site in the coating film is small and the crosslinking efficiency is low. If the amount of light required for photocrosslinking is not obtained, the pattern will be dissolved during development and peeled off. Further, if the photocrosslinking efficiency is low (color resist having low crosslinkage efficiency), the exposure amount required for forming the pattern of the color filter becomes large, so that it takes a considerable time to form the pattern (exposure amount is Is proportional to the exposure time). This becomes more remarkable as the light-shielding property becomes higher, that is, as the transmittance is lowered, and a normal black color resist requires an exposure amount 3 to 10 times that of a colored color resist.

On the other hand, if the transmittance is increased, the photocrosslinking efficiency is improved, but the light-shielding property is deteriorated, so that it is not suitable for the purpose of improving the contrast which is the purpose of the light-shielding color resist.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, the present invention aims to provide a photosensitive resin composition capable of producing a black matrix with a low exposure amount without lowering the light-shielding property. And

[0006]

As a result of intensive research based on the above problems, the present inventors succeeded in developing the photosensitive resin composition described below, and completed the present invention. It was That is, the present invention provides a pseudo-blackening photosensitive resin composition prepared by using at least two kinds of pigments of black, red, green, purple and yellow, wherein the photosensitive resin composition contains an electrolyte substance. This is a pseudo-blackening photosensitive coloring composition.

Hereinafter, the present invention will be described in detail. The pseudo-blackening photosensitive resin composition of the present invention is prepared as follows. At least two types are selected from black, red, green, violet and yellow pigments, and each color is individually dispersed in water by using a dispersant. Examples of black pigments used include carbon black, acetylene black, ivory black, graphite,
Examples include aniline black, mineral black, iron black, titanium black, cyanine black and the like. Examples of red pigments include red iron oxide, red lead, silver vermilion, cadmium red,
Examples thereof include inorganic pigments such as antimony vermilion, organic pigments such as permanent red, chromophthal red, quinacridone red, and thioindigo red. Examples of blue pigments include inorganic pigments such as ultramarine blue, navy blue, cobalt blue, and cerulean blue, and organic pigments such as phthalocyanine blue, indanthrene blue, and indigo. Examples of green pigments include inorganic pigments such as chrome green, viridian, emerald green, cobalt green and zinc green, and organic pigments such as naphthol green and phthalocyanine green. Examples of purple pigments include inorganic pigments such as cobalt purple and manganese purple, and organic pigments such as dioxazine violet and indanthrene brilliant violet. Yellow pigments include yellow lead, zinc yellow, cadmium yellow, barium chromate, titanium yellow, lead cyanamide, and other inorganic pigments, disazo yellow, naphthol yellow, hansa yellow, benzidine yellow, permanent yellow, balkan fast yellow, chromov. Examples include organic pigments such as tar yellow, quinoline yellow, anthragen yellow, and anthrapyridine yellow.

Examples of the dispersant to be used include cationic surfactants, anionic surfactants, ionic surfactants such as amphoteric surfactants, polyoxyethylene alkyl ethers, polyoxyethylene alkyl esters, sorbitan alkyl. There are nonionic surfactants such as esters and polyoxyethylene sorbitan alkyl esters, and various water-soluble polymers. The surfactant used to disperse the pigment in water is highly hydrophilic, that is, H
A surfactant having a high LB value (14 or more) is preferable.

Examples of the cationic surfactant include aliphatic amines, quaternary ammonium salts, alkylpyridinium salts and the like. Examples of anionic surfactants include fatty acid salts, sulfates, sulfonates,
Examples thereof include phosphoric acid esters. Examples of the amphoteric surfactant include amino acid salts and the like.

Examples of water-soluble polymers are polymers or copolymers of butyral resin, polyvinyl alcohol, polyvinylpyrrolidone, acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate and the like. Examples of the acrylic resin include polyacrylamide.

The above dispersant is mixed with water to disperse the pigment. A commercially available sand mill, ball mill, homogenizer, or the like is used to disperse the pigment. The coloring compositions of the respective colors in which the pigments are dispersed are mixed at an appropriate ratio to give a pseudo black color. In order to obtain a pseudo black color, it is only necessary to mix colors having a complementary color relationship, and by such mixing (subtractive color mixture), a color close to black is obtained, and subsequent fine adjustment of the color can be performed with another color.

A photosensitive polymer is added to the obtained black composition. As the photosensitive polymer, a binder resin and a photocrosslinking agent are used in combination. Examples of the binder resin include polyvinyl alcohol, polyvinylpyrrolidone, acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate,
Examples thereof include acrylic resins and polyacrylamides made of polymers or copolymers such as 2-hydroxypropyl methacrylate.

As examples of the photo-crosslinking agent, diazo compounds and azide compounds are preferably used. The diazo compound in the present invention means one having one diazo salt, preferably two or more diazo salts in one molecule, and preferably an aromatic diazo compound is used. Specific examples of this include p-diazodiphenylamine, 2,5-dimethoxy-4-p-tolylmercaptonbenzenediazonium or 2,5-
A condensate of dimethoxy-4-morpholinobenzenediazonium and formaldehyde can be mentioned.

In the present invention, the azide compound means one having one, preferably two or more azide salts in one molecule. The azide compound is usually used in the form of sulfonic acid or sulfonate. 4,4-diazido sturben-
Sodium 2,2'-disulfonate, 2,6-bis (4
-Azidobenzal) acetone 2-sulfonic acid, 2,6
-Bis (4-azidobenzal) acetone 2,2'-disulfonic acid, 2,6-bis (4-azidobenzal) cyclohexanone-2,2'-disulfonic acid, 2,6-bis (4-azidobene Zar) methylcyclohexanone-
2,2'-disulfonic acid and the like can be mentioned.

Too much diazo compound or azide compound
If this happens, the pigment dispersibility will decrease, so the binder solid
It is preferable to add 1 to 30% by weight to the form. Light rack
Since the cross-linking agent is highly reactive, add it just before using it.
Is preferable. Pseudo black produced as described above
An electrolyte substance is added to the colored photosensitive resin composition. The present invention
Electrolyte substance in is a substance that dissolves in water and ionizes.
Say. Examples of electrolyte substances are NaCl, KCl, LiCl, KB
r, KI, Na₂SO_Four, CaCl₂, MgSO_Four, CuSO _Four, CdSO_Four, AlCl₃
Etc.

The amount of the electrolyte added to the pseudo blackening photosensitive resin composition varies depending on the ζ potential of the pigment surface, but is preferably 10% by weight of the pseudo blackening photosensitive resin composition.
It is below, and more preferably from 0.05 to 2% by weight. If it exceeds 10% by weight, the pigment will completely agglomerate and become a coating film.

[0017]

When the pigment particles are dispersed in water, a zeta potential exists on the surface of the pigment. The larger the absolute value of this ζ potential, the stronger the repulsive force of the particles, and the more the dispersion stability of the pigment increases. At this time, when an electrolyte is added to the pigment dispersion liquid, counter ions are adsorbed on the pigment surface, and the ζ potential on the pigment surface decreases. As a result, the pigment particles become agglomerated. Therefore, the amount of electrolyte added is adjusted to add an amount of electrolyte that causes light aggregation. At that time, the surface of the coating film becomes a little rough. That is, the unevenness of the surface of the resist becomes larger than that of a normal coating film, the surface area of the coating film increases, and the reaction sites involved in exposure increase. Also, because the surface becomes rough, the scattering effect occurs,
The transmittance of the coating film decreases. Therefore, the resist added with the electrolyte has a larger number of reaction sites than the resist not added with the electrolyte, so that the pattern can be formed with a small exposure amount, and the formed pattern has a transmittance due to the scattering of the surface. Can be kept low.

In the present invention, by adding an electrolyte to the resist, the pigment particles in the resist are caused to cause a light agglomeration, the surface of the coating film formed from this resist is roughened, and the surface area of the coating film is increased to react. It is possible to reduce the amount of exposure required to form a pattern by increasing the number of areas related to the pattern. In addition, since the surface of the coating film is rough, the transmittance can be reduced due to the effect of surface scattering.

[0019]

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. [Example 1] Phthalocyanine blue, disazo yellow, dioxazine violet and carbon black were selected as the blue, yellow, purple and black pigments, respectively, and dispersed using a sand mill according to the following formulation.

Pigment 20% Polyoxyethylene alkylphenyl ether 5% Water 75% The above color compositions are mixed in the following composition ratios. Blue: yellow: purple: black = 12: 9: 1: 4 To 100 parts by weight of the above colored resin composition was added 50 parts by weight of a 10% aqueous solution of 2-hydroxyethylmethacrylamide, and further 1 part by weight of p-diazodiphenylamine. .

Sodium chloride was added as an electrolyte substance to the photosensitive resin composition thus prepared in an amount of 0.
1 wt% was added. The above sample was applied onto a glass substrate by a spin coater. The film thickness is 1.0 μm and the maximum transmittance is
It was 2.0% at 700 nm. This coating film was pre-baked at 50 ° C. for 3 minutes and exposed at 400 mJ / cm ² through a test pattern whose resolution was understood by a high pressure mercury lamp. After exposure, it was developed with a 1% aqueous solution of malic acid.

At this time, the pattern was formed without flowing up to 10 μm lines by the development. [Comparative Example 1] As a comparative example, a composition obtained by adding no electrolyte substance to the composition of the above-described example was prepared and evaluated in the same manner. The above sample was applied onto a glass substrate by a spin coater. The film thickness was 1.0 μm and the maximum transmittance was 3.0% at 700 nm.

Thereafter, prebaking, exposure and development were performed in the same manner as in Example 1. As a result, at an exposure dose of 400 mJ / cm ^2, the photocrosslinking reaction was incomplete due to insufficient exposure, and the pattern flowed during development. Where in the test pattern
It was found that the exposure amount was 2000 mJ / cm ² when the exposure amount was increased to the point where the 10 μm line was formed.

From the above, it was found that the amount of UV irradiation required for forming a pattern can be reduced by adding an electrolyte substance to the pseudo-blackening photosensitive resin composition.

[0025]

According to the present invention, it is possible to provide a pseudo-blackening photosensitive resin composition which can reduce the transmittance and improve the crosslinking efficiency. According to the present invention, the transmittance is lowered by adding an electrolyte substance and roughening the surface of the coating film, so that the film thickness can be made smaller than that of the coating film without adding the electrolyte. This is extremely useful when incorporated in a liquid crystal module.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G03F 7/038

Claims (1)

[Claims] 1. A pseudo-blackening photosensitive resin composition prepared by using at least two kinds of pigments of black, red, green, violet, and yellow, wherein the photosensitive resin composition contains an electrolyte substance. A pseudo-blackening photosensitive coloring composition comprising: