JPH0713010A - Production of color filter for liquid crystal display - Google Patents

Abstract

PURPOSE:To provide a production method of a color filter by which a color filter can be stably formed with a high degree of freedom of colors by an easy electrodeposition method. CONSTITUTION:The electrodeposition liquid used is a dispersion of fine particles in water. The particle contains polyester 1 as the base polymer which is colored with a dye or pigment and includes unsatd. acid, unsatd. glycol or the like as a part of monomers and 20-1000eq/ton ionic groups. Further, the base polymer contains monomers containing at least one group which reacts with the base polymer, photopolymn. initiator to polymerize the monomer, and sensitizer which sensitizes the initiator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a method for manufacturing a color filter for a liquid crystal display device.

[0002]

2. Description of the Related Art In recent years, various displays have been actively researched due to downsizing of computers and appearance of high-definition television. Under such circumstances, liquid crystal display devices have been attracting attention as the most promising candidates for flat panel displays. There are a TFT array and a color filter array as the main parts of a liquid crystal display device, and a color filter is an extremely important part in a display device that performs color display. Various materials have been proposed as conventional color filter materials, and examples thereof are shown below.

(A) Gelatin dyeing type This is a colorant which is obtained by adding ammonium dichromate to a natural substance, gelatin, to impart photosensitivity, patterning using photolithography, and then dyeing the gelatin to obtain a color filter. Is. The most classic filter,
Gelatin has characteristics such as good heat resistance.

(B) Pigment Dispersion Type A photosensitive polymer previously colored with a pigment is patterned by photolithography, or a colored polymer having no photosensitivity is formed on a substrate and then a photoresist is further applied. Patterning is applied. It is a material that is often used these days, and since the polymer is colored from the beginning, the steps such as dyeing can be omitted.

(C) Printing type An ink formed of a pigment or the like is transferred and formed on a glass substrate by an offset printing method. There is a possibility that it can be manufactured at high speed, which may reduce the cost.

(D) Electrodeposition type A glass substrate having a transparent conductive film is dipped in a solution containing a pigment and a dispersed and charged resin, and a voltage is applied to deposit the resin and the pigment on the transparent conductive film. is there. It has a feature that a large area can be easily manufactured.

[0007]

Each of the color filters described above has the following drawbacks. For (a), gelatin must be dyed every time, and the process is complicated. (B) Since the pigment is dispersed, the sensitivity becomes low. Further, the film swells during development, the dispersion of the pigment is disturbed, and the transparency is lowered. In the case of (c), it is possible that the film can be formed at a high speed, but if the pattern becomes fine, peeling occurs, the production speed cannot be increased, and the merit cannot be utilized. In (d), a pigment is generally used, and a high degree of dispersion control is required to obtain transparency. In addition, a dye or the like is not selected, and the degree of freedom of color is small.

[0008]

SUMMARY OF THE INVENTION The present invention provides a color filter which is stable and has a large degree of freedom of color in the electrodeposition method which is easy to manufacture. That is, the present invention includes, as an electrodeposition liquid used in an electrodeposition method for producing a color filter, an unsaturated acid or an unsaturated glycol colored with a dye or a pigment as one component of a monomer, and 20 As a base polymer, a polyester containing an ionic group in the range of about 1000 eq / ton,
An aqueous dispersion of fine particles containing a monomer having at least one group capable of reacting with the base polymer, a photoinitiator for polymerizing the monomer, and a sensitizer for sensitizing the initiator in the base polymer. Is a method for producing a color filter for liquid crystal display, which is produced using the electrodeposition liquid.

In the present invention, a polyester resin is used as a coloring material used when a color filter is manufactured by the electrodeposition method. The resin has excellent dyeability and pigment dispersibility. Further, since the resin has an ionic group, an aqueous dispersion can be easily manufactured, and
Since it is negatively charged, it is also suitable for anion electrodeposition. The resin electrodeposited on the substrate may be heated and fixed to the substrate. If necessary, a protective film made of resin may be formed thereon for the purpose of protecting the filter or flattening it. Furthermore, when the conductivity is insufficient, ITO may be formed into a film.

Since the present invention uses an unreacted group in the polymer chain and contains a monomer and a photoinitiator that react with the unreacted group, the film produced by electrodeposition uses the photolithography method. Can be directly patterned. Further, since the dispersion of the present invention has a hydrophilic group, water can be used for the development treatment during photolithography. As a result, the filter can be formed at any place even if the ITO on the glass substrate is not patterned. Further, it is possible to easily manufacture a mosaic color filter which has been difficult by the conventional electrodeposition method.

The polyester resin used in the polyester colored particles of the present invention is a polyvalent carboxylic acid and a polyvalent alcohol.
Consists of Examples of the polyvalent carboxylic acids used for the polyester resin include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, diphenic acid, sulfoterephthalic acid, 5- Sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7dicarboxylic acid, 5 [4-sulfophenoxy] isophthalic acid, sulfoterephthalic acid, and / or aromatic dicarboxylic acids such as metal salts and ammonium salts thereof, Aromatic oxycarboxylic acids such as p-oxybenzoic acid and p- (hydroxyethoxy) benzoic acid, aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid and dodecanedicarboxylic acid, fumaric acid, maleic acid Acid, itaconic acid, hexahydrophthalic acid, tetrahydrofuran Le acids, unsaturated aliphatic etc., and the alicyclic dicarboxylic acids, etc., and trimellitic acid are other as polycarboxylic acid, trimesic acid,
Examples thereof include trivalent or higher polyvalent carboxylic acids such as pyromellitic acid.

Examples of the polyvalent alcohols used in the polyester resin include aliphatic polyvalent alcohols, alicyclic polyvalent alcohols, aromatic polyvalent alcohols and the like.
Examples of the aliphatic polyhydric alcohols include ethylene glycol
, Propylene glycol, 1,3-propanedioe
2,3-butanediol, 1,4-butanediol
1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol
, Dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, polyethylene glycol
Examples include aliphatic diols such as propylene, polypropylene glycol and polytetramethylene glycol, triols such as trimethylolethane, trimethylolpropane, glycerin, pentaerythritol and tetraols. it can.

The alicyclic polyvalent alcohols are 1,4-
Cyclohexanediol, 1,4-cyclohexanedimethanol, spiroglycol, hydrogenated bisphenol A, ethylene oxide adduct and propylene oxide adduct of hydrogenated bisphenol A, tricyclodecanediol, Examples thereof include tricyclodecane dimethanol. As aromatic polyhydric alcohols, paraxylene glycol, metaxylene glycol, orthoxylene glycol, 1,4-phenylene glycol, and ethylene oxide adduct of 1,4-phenylene glycol. , Bisphenol A, ethylene oxide adduct of bisphenol A, propylene oxide adduct and the like.

Further, as polyester polyol, ε
Examples thereof include lactone-based polyester polyols obtained by ring-opening polymerization of lactones such as caprolactone. In addition to these, a monofunctional monomer may be introduced into the polyester for the purpose of blocking polar groups at the ends of the polyester polymer. Examples of monofunctional monomers include benzoic acid, chlorobenzoic acid, bromobenzoic acid, parahydroxybenzoic acid, sulfobenzoic acid monoammonium salt, sulfobenzoic acid monosodium salt, cyclohexylaminocarbonylbenzoic acid, n-dodecylaminocarbonylbenzoic acid. Acid, tert-butylbenzoic acid, naphthalenecarboxylic acid, 4-methylbenzoic acid, 3-methylbenzoic acid, salicylic acid, thiosalicylic acid, phenylacetic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, octanecarboxylic acid, lauric acid, stearyl acid , And monocarboxylic acids such as lower alkyl esters thereof, or aliphatic alcohols
Mono alcohols such as alcohol, aromatic alcohol and alicyclic alcohol can be used.

In the present invention, the unsaturated monomer is used as an essential component among these, and the other components are appropriately selected depending on the glass transition temperature of the polyester resin, compatibility with the monomer, and the like.

As the ionic group introduced into the polyester, a mono- or dicarboxylic acid having an alkali metal sulfonate or ammonium sulfonate can be preferably used. For example, an alkali metal carboxylate or ammonium carboxylate can be used. Having a monomer, a sulfuric acid group, a phosphoric acid group, a phosphonic acid group, a phosphinic acid group or an anionic group such as an ammonium salt or a metal salt thereof, or a cationic group such as a primary to tertiary amine group. You can use a quantity etc.

When introducing an alkali metal carboxylate or ammonium carboxylate, a polyvalent carboxylic acid such as trimellitic acid is introduced into the system at the final stage of polymerization of polyester to add a carboxyl group to the polymer terminal. Then, a method of exchanging it with a carboxylate group by neutralizing it with ammonia, sodium hydroxide or the like can be used. Further, by containing a mono- or dicarboxylic acid having an alkali metal sulfonate or ammonium sulfonate, these ionic groups can be introduced into the polyester resin. As salts, ammonium-based ions, Li, Na,
Examples thereof include salts of K, Mg, Ca, Cu, Fe and the like, and particularly preferred are K salt or Na salt. In the present invention, 5-
It is preferable to use sodium sulfoisophthalic acid or metasodium sulfobenzoic acid.

More specific examples other than the unsaturated component and the ionic group-containing component of the polyester resin in the present invention include those shown below. a) a polyvalent carboxylic acid containing 80 mol% or more of an aromatic monomer, and b) a polyester resin obtained from 0 to 90 mol% of ethylene glycol and 100 to 10 mol% of propylene glycol, or a) A polyester resin obtained from polyvalent carboxylic acids containing 80 mol% or more of an aromatic monomer, and b) 2,3-butanediol 5-80 mol% and ethylene glycol 20-95 mol%, or a ) Polyvalent carboxylic acids containing 80 mol% or more of aromatic monomers, b) 70 to 95 mol% of C2 to C4 aliphatic glycols, and c) mono- or polyvalent compounds having a tricyclodecane skeleton. A polyester resin obtained from 5 to 30 mol% of alcohols, or a) a polyvalent carboxylic acid containing 80 mol% or more of an aromatic monomer, and b) a C2 to C4 aliphatic glycol 70-95 mol%, c) hydroxymethyl Polyester resins obtained from cyclodecane 5 to 30 mol%, or,

A) polyvalent carboxylic acids containing 80 mol% or more of an aromatic monomer, b) 70 to 95 mol% of C2 to C4 aliphatic glycols, and c) tricyclodecane dimethanoe. Polyester resin obtained from 5 to 30 mol%, or a) polyvalent carboxylic acid containing 80 mol% or more of an aromatic monomer, and b) 70 to 95 mol of C2 to C4 aliphatic glycols. %, C) a polyester resin obtained from 5 to 30 mol% of mono- or polyvalent alcohols having a cyclohexane skeleton,
Or a) polyvalent carboxylic acids containing 80 mol% or more of an aromatic monomer, b) 70 to 95 mol% of C2 to C4 aliphatic glycols, and c) 5 to 30 mol% of cyclohexanediol. Or a) a) polyvalent carboxylic acid containing 80 mol% or more of an aromatic monomer, b) C2 to C4 aliphatic glycols 70 to 95 mol%, c) water Polyester resin obtained from 5 to 30 mol% of added biphenol, or

A) polycarboxylic acids containing 80 mol% or more of an aromatic monomer, b) 70 to 95 mol% of C2 to C4 aliphatic glycols, and c) hydrogenated bisphenol A5 From 30 to 30 mol%, or a) a polycarboxylic acid containing 80 mol% or more of an aromatic monomer containing 1 to 20 mol% of a mono- or divalent carboxylic acid having a naphthalene skeleton, b) C2 to C4 aliphatic glycols 70 to 100 mol
%, C) Polyvalent alcohol containing 0 to 30 mol% of alicyclic monomer
Examples thereof include polyester resins obtained from and the like. Further, the "a) aromatic monomer" shown here is preferably terephthalic acid or isophthalic acid. The ratio of terephthalic acid and isophthalic acid is terephthalic acid content rate / isophthalic acid content rate = 90-40 /
10 to 60 [mol%] is preferable, and terephthalic acid content / isophthalic acid content = 80 to 50/20 to 50
[Mol%], and furthermore, terephthalic acid content / isophthalic acid content = 85-60 / 15-40 [mol%] is preferable.

When an ionic group-containing monomer is introduced into a polyester resin to give an ionic group to the polyester resin, the polyester resin exhibits water dispersibility. As the ionic group-containing monomer, a mono- or dicarboxylic acid having the above-mentioned alkali metal sulfonate or ammonium sulfonate can be preferably used. For example, a monomer having an alkali metal carboxylate or ammonium carboxylate can be used. Anionic group such as a monomer, a sulfate group, a phosphoric acid group, a phosphonic acid group, a phosphinic acid group or an ammonium salt or a metal salt thereof, or a first
A cationic group monomer such as a primary to tertiary amine group can be used. When an alkali metal carboxylate or ammonium carboxylate is introduced, a polyvalent carboxylic acid such as trimellitic acid is introduced into the system at the final stage of polymerization of polyester to add a carboxyl group to the polymer terminal, It is possible to use a method of neutralizing this with ammonia, sodium hydroxide or the like to exchange it for a carboxylate group.

Note that these alkali metal carboxylates or ammonium carboxylates are not included in the above-mentioned "acid value" (acid value is carboxyl group value, carboxylate salt is not included). The amount is 1 with respect to the polyester resin, including sulfonic acid groups and / or salts thereof.
0-1000 m equivalent / 1000 g, preferably 20-5
00 m equivalent / 1000 g, more preferably 50 to 200
It is m equivalent / 1000 g. When the content of the ionic group is less than the predetermined amount, sufficient water dispersibility cannot be obtained.

As the dye, "a dye insoluble in water at room temperature"
Is preferably used. These are generally classified as disperse dyes or oil-soluble dyes. More specifically, C.I. I. Disperse Yellow 198 C.I. I. Disperse Yellow 42 C.I. I. Disperse Blue 60 C.I. I. Disperse Blue 87 C.I. I. Solvent Green 3 C.I. I. Disperse Red 88 C.I. I. Disperse Red 206 C.I. I. Disperse Blue 56 C.I. I. Disperse Blue 81-C.I. I. Disperse Blue 149 C.I. I. Disperse Blue 197 C.I. I. Disperse Blue 211 C.I. I. Disperse Blue 214 C.I. I. Solvent Blue 25 C.I. I. Solvent Blue 35 C.I. I. Solvent Blue 55 C.I. I. A combination of dyes selected from Solvent Blue 70 is preferred. These are particularly excellent in light fastness, sublimation fastness, hue, and saturation, and are preferable as the three primary colors of red, green, and blue. In addition, known dyes and pigments may be used in combination for fine adjustment of hue.

As a method for incorporating the dye into the polyester resin, a high temperature dispersion dyeing method can be used. The method of directly kneading the dye base material into the resin is not preferable in consideration of the damage of the dye due to heating. Since the polyester resin of the present invention exhibits good stable dispersibility in water due to the action of ionic groups, it is possible to perform high-density dyeing while maintaining the particulate state.

[0025]

Example 1 An ionic group-containing unsaturated polyester resin having the composition shown in Table 1 below was prepared and used as a base polymer, the monomer was divinylbenzene, and the photoinitiator was Irgacur 651. The composition ratio of each material is shown in Table 2 below. Materials shown in Table 2 and dyes C.I. I. So
After dissolving lvent Blue 25 concentrated cake in a mixed solvent of 2 butanone and tetrahydrofuran at 80 ° C., water at 80 ° C. was added to obtain an aqueous microdispersion of a polyester resin having a particle diameter of about 0.15 μm. Further, the obtained water-based microdispersion was placed in a distillation flask and distilled until the distillation temperature reached 100 ° C. After cooling, water was added to make the solid content concentration 30%. Further, the dyes were changed to obtain red and green aqueous microdispersions.

[0026]

[Table 1]

[0027]

[Table 2] Next, the glass substrate with ITO was electrodeposited using the apparatus shown in FIG. The electrodeposition solution was prepared by diluting the previously prepared emulsion solution with water to a solid content concentration of 5% and using ITO.
Was applied as an anode, 5 V was applied, and electrodeposition was performed for about 1 minute. Then, it was washed with water, dried at 100 ° C. for 1 hour, exposed to a mercury lamp at an arbitrary place with a photomask, and further washed with water to wash away unnecessary portions. The above process is repeated three times by changing the electrodeposition liquid, and the color filter is completed.
The color filter manufactured in this way was very transparent. Similarly, instead of dyes,
An aqueous microdispersion using a pigment was also produced, and a color filter could be formed using this.

[0028]

According to the present invention, a color filter which is stable and has a large degree of freedom in color can be manufactured by an electrodeposition method which is simple in manufacturing method.

[Brief description of drawings]

FIG. 1 is a schematic view showing an electrodeposition method for producing a color filter of the present invention.

[Explanation of symbols] 1. Colored polyester particles 1. Glass with ITO 3. Counter electrode 4. Power supply 5. Electroplating tank

Claims (1)

[Claims] 1. An electrodeposition liquid used in an electrodeposition method for producing a color filter, which contains an unsaturated acid or an unsaturated glycol colored with a dye or a pigment as one component of a monomer, and 20 ~ 1000eq / ton
Of a polyester having an ionic group in the range of 1 to 4, a monomer having at least one group reactive with the base polymer, a photoinitiator for polymerizing the monomer, and a sensitization for sensitizing the initiator A method for producing a color filter for liquid crystal display, which comprises using an electrodeposition liquid, which is an aqueous dispersion of fine particles containing the agent in the base polymer.