JPH11174459A - Spacer film for color liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spacer film for a photosensitive color liquid crystal display device which is developable by an aq. org. acid soln., allows easy formation of spacers of fine patterns and has an excellent adhesion property. SOLUTION: This film is used to form spacers for holding the inter-substrate spacing of the color liquid crystal display device holding liquid crystals between two substrates and consists of at least a base film and a photosensitive resin layer developable by the aq. org. acid soln. The photosensitive resin layer of the spacer film is not particularly limited, insofar as the resin is exposed with UV rays, and is developable with the aq. org. acid soln. and more preferably the photosensitive resin layer contg. (A) org. high-polymer compd. of a mol.wt. of 20,000 to 300,000 having an amino group, (B) a photopolymerizable compd. having at least two ethylenic unsatd. group and (C) a photopolymn. initiator is used. The thickness of the photosensitive resin layer is preferably about 4 to 7 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spacer film for a color liquid crystal display for forming a spacer used in a color liquid crystal display or the like, and more particularly to a spacer film for a color liquid crystal display having high adhesion.

[0002]

2. Description of the Related Art Liquid crystal color televisions, computers for liquid crystal color display, and the like have been put to practical use. In these liquid crystal display devices, a transparent substrate such as glass provided with a transparent electrode is provided with an interval of about 1 to 10 μm. Then, a liquid crystal material is sealed in the meantime, the liquid crystal material is oriented by the voltage applied between the electrodes, and the density is displayed. Furthermore, for color display, two or more kinds of very fine stripe or mosaic patterns having different hues are spaced at regular intervals on the surface of an optically transparent substrate such as glass, and are parallel or intersected. Color filters are arranged.

A color filter is usually formed in the order of a transparent substrate, a colored pattern, a protective film, and a transparent electrode. The coloring pattern is composed of an extremely fine stripe or mosaic pattern having two or more different hues.

If the distance between a transparent substrate such as a glass substrate provided with a color filter and the transparent substrate facing the transparent substrate is not accurately maintained, a difference occurs in the thickness of the liquid crystal layer, resulting in color unevenness and abnormal contrast. Therefore, in order to accurately maintain the distance between the transparent substrates, a spacer called 3 to 10 μm
Of silica, alumina, synthetic resin and the like are dispersed and used.

[0005] It is extremely difficult to uniformly disperse the spacers, which leads to a decrease in the yield of a display device having no color unevenness. Therefore, Japanese Patent Application Laid-Open No.
As disclosed in Japanese Unexamined Patent Application Publication No. 3 (1999), various devices have been devised for dispersion and introduction. As a fundamental solution to these problems, a method is known in which a black matrix provided between colored patterns of a color filter is made thicker and used as a spacer (Japanese Patent Laid-Open No.
3-237032, JP-A-3-184022, JP-A-4-122914) have been proposed, but since the black matrix of the thickened portion is formed by coating, it is difficult to control the thickness. Has become.

[0006] Further, by overlapping the colored patterns,
It is also considered to secure the thickness and use it as a spacer (Japanese Unexamined Patent Publication No. 63-82405), but it is difficult to control the film thickness because it is also applied by coating. Further, even if they are stacked, the desired thickness may not be obtained, which is a difficult method.

It has also been proposed that, when a colored pattern is formed, a spacer is formed by forming a colored pattern on a black matrix by a coating method (Japanese Patent Application Laid-Open No. Sho 63-163).
However, it is difficult to obtain a uniform film thickness as described above.

As a method for solving these problems, it has been proposed to use a photosensitive film having a support film and a photosensitive resin layer to form a spacer (Japanese Patent Application Laid-Open No. Hei 7 (1999)).
-325298). Certainly, it is a method that can control the film thickness and can form a uniform spacer, but since it is developed using an inorganic alkali such as sodium carbonate,
The sodium ions adversely affect the liquid crystal, resulting in display failure, and have poor adhesion to the resin black matrix or polyimide alignment film, making it difficult to form spacers with fine patterns.

[0009]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and can be developed with an aqueous solution of an organic acid and can form a fine pattern spacer easily. A spacer film for a display device is provided.

[0010]

According to the present invention, at least a support film and an organic acid are used for forming a spacer for maintaining a distance between substrates of a color liquid crystal display device in which a liquid crystal is sandwiched between two substrates. The present invention relates to a spacer film for a color liquid crystal display device, comprising a photosensitive resin layer developable with an aqueous solution.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The support film of the spacer film in the present invention is not particularly limited, and a known film can be used. Usually, a polyester film of about 10 to 100 μm, for example, Tetron film manufactured by Teijin, manufactured by DuPont. A polyester film such as a Mylar film is preferably used.

The photosensitive resin layer of the spacer film is not particularly limited as long as it can be exposed to ultraviolet light and can be developed with an organic acid aqueous solution.
Molecular weight of 20,000 to 300,000 having an amino group
And a photosensitive resin layer containing (B) a photopolymerizable compound having at least two ethylenically unsaturated groups and (C) a photopolymerization initiator. The thickness of the photosensitive resin layer is preferably about 4 to 7 μm.

(A) a molecular weight of 20,000 having an amino group
The organic polymer compound having 0 to 300,000 is preferably represented by a general formula -NR ¹ R ² (wherein R ¹ and R ² are each independently hydrogen or an alkyl group having 1 to 4 carbon atoms). A compound having an amino group is used. The concentration of the amino group is preferably from 0.29 to 1.46 mmol /
g. If it is less than 0.29 mmol / g, the developability tends to decrease, and if it exceeds 1.46 mmol / g, the resistance tends to decrease, and the resist surface tends to be roughened or peeled off. Molecular weight of 20,000 to 3 having amino group
Specific examples of the organic polymer compound of 00000 include, for example, a copolymer of an alkyl (meth) acrylate and dimethylaminoethyl (meth) acrylate (where (meth) acrylic acid is acrylic acid or methacrylic acid). And the same shall apply hereinafter), and a copolymer of (meth) acrylic acid alkyl ester, (meth) acrylic acid dimethylaminoethyl ester and a vinyl monomer copolymerizable therewith. Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate,
2-ethylhexyl (meth) acrylate and the like. Examples of the vinyl monomer copolymerizable with the alkyl (meth) acrylate or (meth) acrylic acid include tetrahydrofurfuryl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate ( (Meth) acrylate means methacrylate or acrylate, the same shall apply hereinafter.), 2,2,3,3
-Tetrafluoropropyl (meth) acrylate, acrylamide, diacetone acrylamide, styrene, vinyltoluene and the like. Further, instead of dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dipropylaminoethyl (meth) acrylate and the like can also be used. The copolymerization amount of a copolymer component having an amino group, for example, dimethylaminoethyl (meth) acrylate,
The total amount of the copolymer components is preferably 10 to 30 parts by weight. 1
If the amount is less than 0 parts by weight, development becomes difficult. If the amount exceeds 30 parts by weight, development control becomes difficult, and the formed spacer has poor moisture resistance. Methacrylic acid dimethylaminoethyl ester as a copolymer component having an amino group,
It is preferable in that it has excellent developability and is easily available.

The molecular weight of the organic high molecular compound is 20,000.
If it is less than 10, the fluidity and adhesive strength of the photosensitive resin layer are significantly increased, and the adhesion to the transparent support film becomes too strong, so that it is difficult to peel off at the interface between the photosensitive resin layer and the transparent support film, or it is difficult to remove. Tends to be possible. Alternatively, since the solubility in a developing solution is extremely increased, the developing solution resistance of the photosensitive resin layer after the exposure is greatly reduced, and the photosensitive resin layer tends to be unusable as a resist. When the molecular weight exceeds 300,000, the fluidity and adhesive strength of the photosensitive resin layer are remarkably reduced, and the photosensitive resin layer does not stick to the substrate at the time of lamination, or when the film is cut into the substrate size, a minute cut of the photosensitive resin layer Debris tends to be generated, and there is a tendency for problems such as contamination of peripheral devices to occur. In addition, this molecular weight means the weight average molecular weight measured by the GPC method and converted using a standard polystyrene calibration curve.

[0015] The compounding amount of the component (A) is the combination of the component (A) and the component (B).
Preferably 30 to 70 parts by weight based on 100 parts by weight of the total amount of the components.
Parts by weight. If the amount is less than 30 parts by weight, the coating properties tend to be insufficient, and the developability tends to decrease.
If the amount exceeds 0 parts by weight, the film properties of the cured product tend to deteriorate.

As the photopolymerizable compound (B) having at least two ethylenically unsaturated groups, for example, a compound obtained by adding an α, β-unsaturated carboxylic acid to a polyhydric alcohol (trimethylolpropane diamine) (Meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc.), and a glycidyl group-containing compound with an α, β-unsaturated carboxylic acid (Trimethylolpropane triglycidyl ether triacrylate, bisphenol A diglycidyl ether di (meth) acrylate, etc.), a compound having a polyvalent carboxylic acid (phthalic anhydride, etc.) and a hydroxyl group and an ethylenically unsaturated group (β -Hydroxyethyl (meth) acrylate Ester compound with
Alkyl (meth) acrylate (methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, etc.), trimethylhexamethylene diisocyanate and divalent Examples thereof include a urethane diacrylate compound obtained by reacting an alcohol with a (meth) acrylic acid hydroxymonoester, and 2,2-bis (4-methacryloxypolyethoxyphenyl) propane. Two or more of these compounds may be used.

The amount of the component (B) is between (A) and (B).
Preferably 30 to 70 parts by weight based on 100 parts by weight of the total amount of the components.
Parts by weight. If the amount is less than 30 parts by weight, the photosensitivity is insufficient, the film properties of the cured product are reduced, and it becomes difficult to use as a spacer. If the amount exceeds 70 parts by weight, the coating properties and developability tend to be insufficient.

(C) Examples of the photopolymerization initiator include benzophenone, 4,4'-dimethylaminobenzophenone (Michler's ketone), 4,4'-diethylaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, Aromatic ketones such as ethylanthraquinone and phenanthrenequinone; benzoin such as benzoin methyl ether, benzoin ethyl ether and benzoin phenyl ether; 2- (o-chlorophenyl)-
4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl)
-4,5-diphenylimidazole dimer, 2- (o-
(Fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer Body, 2, 4
-Di (p-methoxyphenyl) -5-phenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-
2,4,5-triarylimidazole dimer and the like such as diphenylimidazole dimer and 2- (p-methylmercaptophenyl) -4,5-diphenylimidazole dimer are used.

The amounts of component (C) and component (A) and component (B)
Preferably 0.1 to 1 with respect to 100 parts by weight of the total amount of the components.
0 parts by weight. When the amount is less than 0.1 part by weight, the photosensitivity becomes insufficient. When the amount exceeds 10 parts by weight, light absorption on the surface of the photosensitive resin layer at the time of exposure increases, and the internal light curing becomes insufficient. Tend.

In addition, the photosensitive resin layer may contain coloring agents such as pigments and dyes, polymer beads, inorganic fillers, stabilizers for thermopolymerizable components, and thermosetting resins such as melamine resins.

It is preferable to use a protective film for protecting the photosensitive resin layer. As the protective film, for example, a polyester film, a polyolefin film or the like is used, and from the viewpoints of price, flexibility, strength, hardness and the like, a polyolefin film, especially a polyethylene film or a polypropylene film is preferable. The thickness is preferably from 10 to 40 μm, and if it is less than 10 μm, the handleability tends to be inferior.
If it exceeds m, the cost tends to increase.

The spacer film of the present invention forms a photosensitive resin layer by coating a photosensitive resin solution on a support film surface with a roll coater, comma coater, gravure coater, air knife coater, die coater, bar coater, etc. After that, it is manufactured by laminating a protective film.

The spacer film of the present invention is used to form a spacer for maintaining a distance between substrates of a color liquid crystal display device in which a liquid crystal is sandwiched between two substrates. The substrate is not particularly limited as long as it is transparent, and examples of the material include glass and plastic. The liquid crystal is not particularly limited, and a known liquid crystal is used. Although a black matrix is usually provided on the substrate, the black matrix is not particularly limited, and a known black matrix is used. For example, a black matrix can be provided on a substrate by sputtering metal such as chromium and then etching it in a pattern.

A spacer using the spacer film of the present invention is manufactured as follows. First, a black matrix, a colored pattern, a protective flattening film, a transparent electrode, and an alignment film are formed on a transparent substrate, and if necessary, the substrate is heated (100 to 200 ° C., 3 to 30 ° C.).
Minutes), the photosensitive resin layer is laminated (laminated) while the protective film of the spacer film is peeled off on the substrate, and the support film on the surface of the photosensitive resin layer is peeled off. A negative mask having a predetermined pattern is placed and exposed. Lamination may be performed before the formation of the transparent electrode or the alignment film. Then, the exposed portion is developed with a developing solution to form a spacer (pattern). The laminating step is performed while heating and softening the photosensitive resin layer by a heatable roll generally called a hot roll or a heating jacket called a heat shoe and a roll called a laminating roll.

In the exposure step, there is generally a dedicated exposure machine,
This is performed using a contact or non-contact type. As the lamp, a lamp that effectively emits ultraviolet light, such as a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, or a xenon lamp, can be used.

Examples of the developing method include a dip method and a spray method, and a high-pressure spray method is most suitable for high resolution. As the developer, an organic acid aqueous solution is used, and it is preferable to use an aqueous acetic acid solution of 2 to 10% by weight. If the concentration is less than 2% by weight, development tends to be difficult, and if it exceeds 10% by weight, the resist tends to peel off. Besides, formic acid, citric acid, oxalic acid, malonic acid, succinic acid and the like can also be used.

[0027]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

EXAMPLE A chromium metal having a thickness of 0.1 μm was formed on a glass substrate by sputtering, and was etched using a photoresist to obtain a grid-like black matrix. Then, red, green and blue patterns were prepared using a photosensitive film type pigment dispersion resin. A protective layer of an acrylic resin was formed thereon using a spin coater, and planarization was performed. A transparent electrode ITO is formed thereon by sputtering,
An alignment film of polyimide was formed thereon. This board is
After heating at 00 ° C. for 10 minutes, a solution of the photosensitive resin composition shown in Table 1 was evenly applied on a polyethylene terephthalate film (support film 20 μm thick) on the substrate, and a hot air convection dryer at 100 ° C. After drying for about 10 minutes to form a photosensitive resin layer of 5.5 μm thickness, a spacer film (photosensitive film) laminated with a 30 μm thick polypropylene film as a protective film is peeled off while removing the polypropylene film. The resin layer was laminated at a speed of 1.0 m / min using a pressurized roll at a roll temperature of 100 ° C. Next, exposure was carried out by an exposure machine HMW-590 (3 KW, ultra high pressure mercury lamp, manufactured by Oak Manufacturing Co., Ltd.) through a negative mask having a predetermined pattern. Thereafter, the polyethylene terephthalate film was removed, and 5% by weight at 30 ° C.
Unexposed portions were removed by spray development with an acetic acid aqueous solution for 30 seconds to form a spacer. The thickness of the spacer was 5.0 μm. The minimum pattern obtained is 6 μm
The corners were excellent.

Next, a color liquid crystal display device was manufactured by sealing the electrode substrate facing the color filter side substrate on which the spacer was formed with a sealing material and injecting liquid crystal. This color liquid crystal display had a bright and excellent display without display unevenness.

Comparative Example Table 2 shows the composition of the photosensitive resin layer of the spacer film used.
Was carried out in the same manner as in Example except that the development was carried out at 30 ° C. for 15 seconds with 0.1% by weight of sodium carbonate. As a result, the film thickness was 5.0 μm, but the obtained minimum pattern was 10 μm square.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

By using the photosensitive spacer film of the present invention, a spacer having a fine pattern can be formed, and a bright and excellent quality color liquid crystal display device can be easily manufactured with good workability due to little light shielding. .

Claims (3)

[Claims] 1. A photosensitive resin developable with at least a support film and an organic acid aqueous solution, which is used to form a spacer for maintaining a distance between substrates of a color liquid crystal display device in which a liquid crystal is sandwiched between two substrates. A spacer film for a color liquid crystal display device, comprising a layer. 2. A photosensitive resin layer comprising: (A) an organic polymer compound having an amino group and a molecular weight of 20,000 to 300,000; and (B) a photopolymerizable compound having at least two ethylenically unsaturated groups. 2. The spacer film for a color liquid crystal display device according to claim 1, further comprising (C) a photopolymerization initiator and developable with an organic acid aqueous solution. (A) a molecular weight of 20,0 having an amino group
3. The spacer film for a color liquid crystal display device according to claim 2, wherein the organic polymer compound having a dimethylaminoethyl group derived from dimethylaminoethyl methacrylate has a molecular weight of from 00 to 300,000.