JPH11202124A - Method for manufacturing color filter substrate, color filter substrate manufactured by same method, and liquid crystal element using same substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the manufacture which manufactures the color filter sub strate having no density unevenness in good yields through simple processes. SOLUTION: On a substrate, partition walls are formed and ink with 20-60 dyn/cm surface tension is given in areas between the partition walls and cured to obtain the color filter 5. In this case, the volume of the ink given to one area is less than 3 to 10 times as large as the capacity of the area. This liquid crystal element is formed by sandwiching liquid crystal between a couple of substrates and the color filter substrate manufactured as mentioned above is used as one of the said substrates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a color filter substrate used for a color television, a personal computer, and the like, a color filter substrate manufactured by the method, and a liquid crystal device using the substrate. is there.

[0002]

2. Description of the Related Art In recent years, the development of personal computers,
In particular, with the development of portable personal computers, the demand for liquid crystal displays, especially color liquid crystal displays, tends to increase. However, cost reduction is necessary for further popularization, and in particular, there is an increasing demand for cost reduction of color filters having a high specific gravity.

Conventionally, various methods have been tried to satisfy the above requirements while satisfying the required characteristics of the color filter, but no method has yet been established which satisfies all the required characteristics. The respective methods will be described below.

The first method is a pigment dispersion method. In this method, first, a photosensitive resin layer in which a pigment is dispersed is formed on a substrate, and a monochromatic pattern is obtained by patterning the photosensitive resin layer. Further, by repeating this step three times, R,
G and B color filters are formed.

[0005] The second method is a dyeing method. This method
First, a water-soluble polymer material, which is a material for dyeing, is formed on a substrate, and is patterned into a desired shape by a photolithography process. Then, the obtained pattern is immersed in a dye bath to form a colored pattern. obtain. By repeating this three times, R, G, and B color filters are formed.

A third method is an electrodeposition method. In this method, a transparent electrode is first patterned on a substrate, and a pigment,
The first color is electrodeposited by dipping in an electrodeposition coating solution containing a resin, an electrolytic solution or the like. This process is repeated three times to form R, G, and B color filters, and finally fired.

A fourth method is to form a colored layer by dispersing a pigment in a thermosetting resin, repeating R, G, and B by repeating printing three times, and then thermosetting the resin. , A color filter.

In any of the above methods, a protective film is generally formed on a color filter.

[0009]

The common feature of the above-mentioned methods is that the same process must be repeated three times in order to color the three colors R, G, and B, which increases the cost. is there. Also, there is a problem that the yield decreases as the number of processes increases. Further, in the electrodeposition method, since the pattern shape that can be formed is limited, it is difficult to apply the current technology for TFT. Further, the printing method is not suitable for forming a fine pitch pattern because of poor resolution.

In order to compensate for these drawbacks, Japanese Patent Application Laid-Open No.
9-75205, JP-A-63-235901, JP-A-1-217302 and the like,
Still not enough.

In particular, in the conventional method of applying ink to an ink receiving layer, the heat resistance and solvent resistance of the ink receiving layer are low, so that the process of forming the ITO and the alignment film is limited by the process. This makes it difficult to form a highly reliable liquid crystal element. As a method for solving such a problem, a method of forming a color filter by directly applying a curable ink onto a substrate has been proposed. FIG.
FIG. 2 is a schematic sectional view showing the steps of this method. In the figure, 1 is a transparent substrate, 2 is a partition between color filters, 3 is an ink jet recording device, 4 is a curable ink, 5 is a color filter, and 6 is a protective film.

As shown in FIG. 3, a partition 2 having ink repellency is formed on a transparent substrate, and a curable ink 4 is applied from an ink jet recording apparatus 3 to a region surrounded by the partition 2 (see FIG. 3). 3 (a)), the curable ink 4 is cured by light irradiation or heat treatment to form a color filter 5 (FIG. 3).
(C)) Then, if necessary, a protective film 6 is formed (FIG. 3D).

In this step, it is necessary to distribute the curable ink throughout the region surrounded by the partition wall 2 without any loss. Normally, the uncured ink 4 forms a curved surface by surface tension as shown in FIG. In the subsequent ink drying step, the solvent of the ink evaporates, and only the solids such as the coloring material, the resin, and the additives contained in the ink remain, and the curing process forms a colored cured composition, that is, a color filter. . In the drying step, the curvature of the ink surface changes as the solvent evaporates, and the surface shape of each color filter is determined by the final curvature. Therefore, when the final curvature is large, a large difference in film thickness may occur in the color filter. Since the unevenness of the film thickness of the color filter directly becomes the unevenness of the density of the color filter and affects the display characteristics, it is required to minimize the difference in the film thickness.

An object of the present invention is to provide a method for manufacturing a color filter substrate having no density unevenness in a simple process with a high yield.

Still another object of the present invention is to provide a color filter substrate having no unevenness in density manufactured by this manufacturing method, and a liquid crystal element having excellent color display characteristics using the color filter substrate.

[0016]

According to the present invention, there is provided a method of manufacturing a color filter substrate, comprising the steps of: forming a partition on the substrate;
A surface tension of 20 to 60 dyn is applied to a region between the partition walls.
a step of applying e / cm ink and a step of curing the ink to form a color filter, wherein the volume of the ink applied to one area is at least three times the volume of one area. It is characterized by being 10 times or less.

Further, the liquid crystal element of the present invention comprises a pair of substrates with liquid crystal interposed therebetween, and uses a color filter substrate manufactured by the above-described manufacturing method for one of the substrates.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic sectional view showing the steps of one embodiment of a method for manufacturing a color filter substrate according to the present invention. The reference numerals in the figure are the same as those in FIG. 3 described above.

As the transparent substrate 1 used in the present invention, a glass substrate is generally used, but other materials may be used as long as they satisfy required characteristics such as transparency and mechanical strength as a color filter substrate. Can be.

FIG. 1A shows a step of forming a partition 2 having ink repellency on a transparent substrate 1 and applying a curable ink 4 by an ink jet recording apparatus 3.
In the present invention, the partition wall 2 is a member provided to form a concave portion for receiving the curable ink 4 and to prevent mixing of inks of different colors between adjacent color filters.
The partition 2 can be easily formed by patterning a photosensitive resist, for example. However, the partition can also be used as a black matrix or a black stripe. In this case, the black resist may be patterned.

In the present invention, the barrier ribs 2 may be formed directly on the transparent substrate 1, but may be formed on a substrate on which a layer having another function is formed as required, for example, on an active matrix substrate on which a TFT array is formed. You may. In either case, the surface of the color filter forming surface may be subjected to some surface treatment in order to enhance the diffusibility of the curable ink.

The curable ink 4 used in the present invention is an ink that is cured by light irradiation, heat treatment, or a combination thereof. The curable ink 4 is used to suppress the difference in film thickness of a color filter formed with this ink to 0.2 μm or less. , Its surface tension is 20 to 60 dyne / cm, and furthermore, 40 to 60 dyne
yne / cm, especially 50 dyne / cm to 60 dyne
/ Cm. In the present invention, the surface tension is a value measured by a vertical plate method (a Wilhelmy method).

As the curable ink 4, both liquid ink and solid ink can be used within a range satisfying the above conditions, and both pigment and dye can be used. The ink 4 contains a resin component, a coloring material, an organic solvent, and water that are cured by light irradiation, heat treatment, or a combination thereof.

As the coloring material, any of pigments and dyes can be used. Examples of the dye include C.I. I. Ac
id Red 118, C.I. I. Acid Red 2
54, C.I. I. Acid Green 25, C.I. I.
Acid Blue 113, C.I. I. Acid Bl
ue 185, C.I. I. Acid Blue 7 and pigments such as C.I. I. Pigment Re
d177, C.I. I. Pigment Red 5,
C. I. Pigment Red 12, C.I. I. Pi
gment Green 36, C.I. I. Pigmen
t Blue 209, C.I. I. Pigment Bl
ue 16, etc. are preferably used. The content of the coloring material is preferably 0.1 to 15% by weight based on the ink.

As the curing component, commercially available resins and curing agents can be used, and specifically, acrylic resins, epoxy resins, melamine resins, and the like are suitably used. The content of these resin components is preferably from 0.1 to 15% by weight, and more preferably from 5 to 10% by weight, so that the surface tension falls within the above range.

Examples of the organic solvent include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-
C1-C4 alkyl alcohols such as butyl alcohol and tert-butyl alcohol; amides such as dimethylformamide and dimethylacetamide; acetone;
Ketones or keto alcohols such as diacetone alcohol; ethers such as tetrahydrofuran and dioxane;
Polyalkylene glycols such as polyethylene glycol and polypropylene glycol; ethylene glycol;
Alkylene glycols having an alkylene group containing 2 to 6 carbon atoms, such as propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, diethylene glycol; glycerin; ethylene glycol Lower alkyl ethers of polyhydric alcohols such as monomethyl (or ethyl) ether, diethylene glycol methyl (or ethyl) ether, and triethylene glycol monomethyl (or ethyl) ether; N-methyl-2-pyrrolidone, 2-pyrrolidone, 1, 3 -Dimethyl-2-imidazolidinone.

The amount of the organic solvent to be added to the ink is preferably 5 to 50% by weight in view of the initial discharge performance of the ink, the continuous discharge stability and the like.

In the present invention, the applied amount of the curable ink 4 is 3 to 10 times, preferably 8 times or less, of the volume of the area surrounded by the partition wall 2, and when it is 8 times or less, the amount of the color filter is reduced. The difference in in-plane film thickness can be suppressed within 0.1 μm. If the applied amount of the curable ink 4 is more than 10 times the volume of the corresponding area, the difference in the in-plane film thickness of the color filter becomes larger than 0.2 μm, which is not preferable because the density unevenness occurs. If it is less than three times, a predetermined amount of film thickness cannot be obtained, which is not preferable.

After applying the curable ink 4 to each region between the partition walls (FIG. 1 (b)), a drying process is performed if necessary.
The ink is cured by light irradiation or heat treatment, or a combination thereof to form a color filter 5 (FIG. 1).
(C)).

If necessary, a protective film 6 is formed on the color filter 5 (FIG. 1D). As the protective film 6, a resin material curable by light irradiation or heat treatment, or a combination thereof, or an inorganic film formed by vapor deposition or sputtering can be used. In the case of forming a liquid crystal element, any process that can withstand an ITO film forming process, an alignment film forming process, or the like can be used.

Next, FIG. 2 is a schematic cross-sectional view of one embodiment of a liquid crystal element constituted by using the color filter substrate manufactured in the above steps. In the figure, 8 is a common electrode, 9 is an alignment film,
11 is a counter substrate, 12 is a pixel electrode, 13 is an alignment film, 14
Is a liquid crystal compound.

The present embodiment relates to an active matrix type color liquid crystal element using TFTs, and a color filter 5.
This is formed by combining the substrate on which is formed with the counter substrate 11 and sealing the liquid crystal compound 14 in a gap (about 2 to 5 μm) between the substrates. A TFT (not shown) and pixel electrodes 12 are formed in a matrix on a counter substrate 11, and a color filter 5 is formed on the other substrate 1 at a position facing the pixel electrodes 12, and a transparent common electrode 8 is formed thereon. Are formed. Furthermore, alignment films 9 and 13 are provided in the plane of both substrates.
Are formed, and by subjecting them to a rubbing treatment, liquid crystal molecules can be arranged in a certain direction.

A polarizing plate is adhered to the outside of both substrates of the liquid crystal element of the present embodiment, and a display is realized by functioning as an optical shutter for changing the transmittance of light from a backlight combining a fluorescent lamp and a scattering plate. Do.

In the present invention, the conventional materials and forming methods can be applied to members other than the members described in the above embodiment.

[0035]

[Example 1] Black resist (trade name: CK-
S171B (manufactured by Fuji Hunt), and a black matrix was formed on the glass substrate by photolithography. The size of one opening of this black matrix was 70 μm × 220 μm, and the film thickness was 1 μm. Therefore, the volume of the area to which the curable ink is applied is 15400 μm.
m is ^3. Therefore, eight times this volume is 123000μ
m ³ , 10 times is 154000 μm ³ .

An ink was applied to each opening of the black matrix using an ink jet recording apparatus under the condition that the amount of ink applied to one opening was 12000 μm ³ (120 pl). As the curable ink, a dye, a water-soluble organic solvent, water, a resin composition comprising a binary copolymer of N-methylolacrylamide and methyl methacrylate, a surfactant for adjusting surface tension, and a resin concentration of 5 were used.
Wt%, dye component is 5 wt%, surface tension is 60 dyne
/ Cm.

Red dyes include C.I. I. Acid
Red 158 was used. As a Green dye,
C. I. Direct Blue (DBL) 86 to C.I.
I. What was toned with Acid Yellow (AY) 23 was used. As a Blue dye, DBL86 is C.I.
I. Acid Red (AR) 289 was used.

As a water-soluble organic solvent, ethylene glycol was used in an amount of 20% by weight, thiodiglycol was added in an appropriate amount, and all inks had a surface tension of 60 dyne / c.
m. The surface tension was measured using an automatic surface tensiometer CBVP-Z type (manufactured by Kyowa Interface Science Co., Ltd.) in all examples.

The ejection of the curable ink from the ink jet recording apparatus was good for inks of all colors. After applying the curable ink, the ink was cured by heat treatment at 200 ° C. for 1 hour.

The surface shape of the color filter substrate produced as described above was measured using a surface roughness measuring device (trade name: P10,
As a result, the thickness of the color filter was 0.6 μm on average, and the thickness unevenness was 0.1 μm or less. In addition, problems such as color mixing and density unevenness were not observed.

Further, a series of operations such as formation of a protective film, formation of an ITO (electrode), formation of an alignment film, and sealing of a liquid crystal material were performed on the color filter substrate to produce a liquid crystal element for color display. When this liquid crystal element was driven continuously in a temperature range of -20 ° C to 60 ° C for 1000 hours, no display problem occurred.

Example 2 The procedure of Example 1 was repeated except that the resin composition of the curable ink was a terpolymer of N-methylolacrylamide, methyl methacrylate and hydroxyethyl methacrylate. To produce a color filter substrate. The surface tension was adjusted to 60 dyne / cm by adjusting the amount of thiodiglycol contained.

Also in this example, the dischargeability of the curable ink by the ink jet was good. When the surface shape of the color filter substrate of this example was measured in the same manner as in Example 1, the average thickness of the color filter was 0.6 μm.
m and the film thickness unevenness were 0.1 μm or less. Also, mixed colors,
No problems such as uneven density were observed.

Using the above color filter substrate, a liquid crystal element was produced in the same manner as in Example 1, and the liquid crystal element was driven in a temperature range of -20 ° C. to 60 ° C. for 1000 hours. As a result, no display problem occurred. .

Example 3 In the curable ink of Example 1, the surface tension of each curable ink was adjusted to 50 dyne / cm by changing the amount of thiodiglycol added. A color filter substrate was manufactured in exactly the same manner as in Example 1.

Also in the present embodiment, the dischargeability of the curable ink by the ink jet was good. When the surface shape of the color filter substrate of this example was measured in the same manner as in Example 1, the average thickness of the color filter was 0.6 μm.
m and the film thickness unevenness were 0.1 μm or less. Also, mixed colors,
No problems such as uneven density were observed.

Using the above-mentioned color filter substrate, a liquid crystal element was produced in the same manner as in Example 1, and was driven continuously at a temperature in the range of -20 ° C. to 60 ° C. for 1,000 hours. As a result, no display problem occurred. .

Example 4 A color filter substrate was prepared in exactly the same manner as in Example 1 except that the concentration of the resin component of the curable ink was set to 7% by weight for each color ink and the dye component was set to 3% by weight. Was prepared. At this time, the surface tension of each ink was 50 dyne / cm.

Also in the present embodiment, the dischargeability of the curable ink by the ink jet was good. When the surface shape of the color filter substrate of this example was measured in the same manner as in Example 1, the average thickness of the color filter was 0.8 μm.
m, the film thickness unevenness was 0.2 μm or less. Also, mixed colors,
No problems such as uneven density were observed.

Using the above-mentioned color filter substrate, a liquid crystal element was produced in the same manner as in Example 1, and the liquid crystal element was driven in a temperature range of -20.degree. C. to 60.degree. C. for 1,000 hours. .

Example 5 The amount of curable ink applied was 15
A color filter substrate was produced in exactly the same manner as in Example 1 except that the thickness was changed to 0000 μm ³ .

When the surface shape of the color filter substrate of this example was measured in the same manner as in Example 1, the thickness of the color filter was 0.6 μm on average, and the thickness unevenness was 0.19 μm or less. In addition, problems such as color mixing and density unevenness were not observed.

Using the above color filter substrate, a liquid crystal element was prepared in the same manner as in Example 1, and was driven continuously for 1000 hours in a temperature range of -20 ° C. to 60 ° C., and no display problem occurred. .

Example 6 Positive resist (trade name: OF
PR-800) was formed on a glass substrate so as to have a film thickness of 1 μm, and a color filter substrate was produced in exactly the same manner as in Example 1 except that a partition was formed by patterning by photolithography.

When the surface shape of the color filter substrate of this example was measured in the same manner as in Example 1, the thickness of the color filter was 0.6 μm on average and the thickness unevenness was 0.1 μm or less. In addition, problems such as color mixing and density unevenness were not observed.

The above color filter substrate was used. As the counter substrate, a substrate in which a resin black matrix was formed on a TFT array was used.
A series of operations such as enclosing a liquid crystal material were performed to produce a color display liquid crystal element. When this liquid crystal element was driven continuously in a temperature range of -20 ° C to 60 ° C for 1000 hours, no display problem occurred.

Example 7 A black matrix (trade name: CK-S171B, manufactured by Fuji Hunt Co.) was used on a substrate on which a TFT array was formed. A color filter substrate was manufactured in exactly the same manner as in Example 1.

When the surface shape of the color filter substrate of this example was measured in the same manner as in Example 1, the thickness of the color filter was 0.6 μm on average, and the thickness unevenness was 0.1 μm or less. In addition, problems such as color mixing and density unevenness were not observed.

Using the above-mentioned color filter substrate and a transparent glass substrate as a counter substrate, a series of operations such as formation of ITO, formation of an alignment film, enclosing of a liquid crystal material were performed, and a liquid crystal element for color display was produced. This liquid crystal element is
When the device was driven for 1000 hours in a temperature range of 60 ° C., no display problem occurred.

[Comparative Example 1] The applied amount of the curable ink was 19
A color filter substrate was manufactured in the same manner as in Example 1 except that the thickness was changed to 0000 μm ³ (190 pl). When the surface shape of the color filter substrate was measured in the same manner as in Example 1, the thickness of the color filter was 1.0 μm on average, and the thickness unevenness was 0.3 to 0.45 μm.

Comparative Example 2 The curable ink had a surface tension of 1
A color filter substrate was produced in the same manner as in Example 1 except that the color filter substrate was set to 5 dyne / cm. When the surface shape of the color filter substrate was measured in the same manner as in Example 1, the thickness of the color filter was 1.0 μm on average, and the thickness unevenness was 0.25 μm.
m.

[0062]

As described above, according to the present invention,
A color filter substrate without density unevenness can be provided in a simple process with a good yield. By using the color filter substrate, a highly reliable liquid crystal element having excellent color display characteristics can be provided at low cost. .

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing the steps of one embodiment of a method for manufacturing a color filter substrate of the present invention.

FIG. 2 is a schematic sectional view of one embodiment of the liquid crystal element of the present invention.

FIG. 3 is a schematic cross-sectional view illustrating an example of a conventional process for manufacturing a color filter substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Partition wall 3 Ink jet recording device 4 Curable ink 5 Color filter 6 Protective film 8 Common electrode 9 Alignment film 11 Opposite substrate 12 Pixel electrode 13 Alignment film 14 Liquid crystal compound

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Koichiro Nakazawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yasushi Takatori 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside (72) Inventor Takeshi Ken Miyazaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (9)

[Claims] 1. A step of forming a partition on a substrate, and a surface tension of 20 to 60 dyne / c in a region between the partition and the partition.
m, and a step of curing the ink to form a color filter, wherein the volume of the ink applied to one of the areas is three times or more and ten times the volume of one of the areas. A method for manufacturing a color filter substrate, comprising: 2. The method according to claim 1, wherein the surface tension is 40 to 60 dyne /
2. The method for producing a color filter substrate according to claim 1, wherein 3. The method according to claim 2, wherein the surface tension is 50 to 60 dyne /
2. The method for producing a color filter substrate according to claim 1, wherein 4. The method according to claim 1, wherein the resin component contained in the ink is 0.1 to 15% by weight based on the ink. 5. The method for producing a color filter substrate according to claim 1, wherein the resin component contained in the ink is 5 to 15% by weight based on the ink. 6. The method for manufacturing a color filter substrate according to claim 1, wherein the volume of the ink applied to one of the regions is at least three times and at most eight times the volume of one of the regions. 7. The method according to claim 1, wherein the substrate is an active matrix substrate having a TFT array, and the partition is a black matrix formed by patterning a black resist. 8. A color filter substrate manufactured by the manufacturing method according to claim 1. 9. A liquid crystal element in which liquid crystal is sandwiched between a pair of substrates, wherein one of the substrates uses the color filter substrate according to claim 8.