JPH10274709A - Coloring composition for color filter, color filter, and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color filter which is excellent in display quality by using a laser processing method, which has excellent spectral characteristics, contrast, heat resistance, has colored pixels with extremely small shoulder sag. SOLUTION: In a coloring composition for a color filter containing a coloring agent, a binder, and a solvent as essential components, the coloring agent is a dye, and the binder is at 200 ° C.
A coloring composition for a color filter, which is a thermosetting binder having the above curing temperature, a color filter in which a colored pixel formed of the coloring composition is formed, and a laser processing method using the coloring composition. Manufacturing method of color filter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coloring composition for a color filter used in a color liquid crystal display device, a color filter having a colored coating film formed by using the coloring composition, and a method for using the coloring composition. And a method for manufacturing a color filter.

[0002]

2. Description of the Related Art A color liquid crystal display device is provided with a color filter in which two or three or more types of colored pixels having different hues are formed in a pattern on a transparent substrate.
Generally, three primary colors of red, blue, and green are used as the hues of the colored pixels. If desired, pixels of the fourth color or higher and a black matrix may be formed. Conventionally, as a method for manufacturing a color filter, for example, a method using an ultraviolet curable resin containing an organic dye has been proposed (Japanese Patent Application Laid-Open No. 58-7608). In this method, a step of applying a positive resist on a substrate, a step of exposing and developing the positive resist through a mask pattern to form a predetermined pattern, and forming an organic resist on the substrate on which the positive resist pattern is formed. A step of applying a UV-curable resin containing a dye on the entire surface, a step of exposing the entire surface to UV light to cure the UV-curable resin and exposing a positive resist pattern, and a step of exposing the exposed positive resist pattern to the UV-curable Colored pixels of each color are formed by repeating the respective steps of forming a filter pattern made of an ultraviolet curable resin that is removed by being removed together with the resin.

In order to increase the transparency of a colored image (colored pixel) in which a pigment is dispersed, a pigment having a particle size distribution such that particles having a particle size of 1 μm or more account for 10% by weight or less of all particles is used. There has been proposed a method for producing a color filter for forming a patterned transparent colored image of a plurality of colors on a support using a resin composition dispersed in a photosensitive resin (Japanese Patent Publication No. 4-39041). . In this method, a coating film of a photosensitive resin composition in which a pigment of a first hue is dispersed is formed on a substrate, the coating film is exposed to light through a mask pattern, and developed to form a first coating. Is formed, and the same steps are repeated thereon to form colored pixels of the second and third hues.

[0004] These conventional methods are photolithographic methods, and in each case, after exposure, development is performed using a developing solution such as water or an organic solvent to remove exposed or unexposed portions that are dissolved in the developing solution. Thus, a colored pixel is obtained. In such a method, waste liquid treatment of the developing solution is necessary, and furthermore, undissolved substances, dust, and the like from the developing solution are mixed in the colored pixels, which causes pixel defects. Further, in the method using a colored photosensitive resin, there is a difference in sensitivity and resolution depending on the performance of the photosensitive component and the resin component, or the light absorption characteristics of the coloring agent (dye or pigment). Therefore, in order to obtain desired sensitivity and resolution, it is necessary to select each component of the colored photosensitive resin composition. Therefore, the colored photosensitive resin composition had to be expensive. In addition, in this method, the number of steps for obtaining a colored pixel is large, causing a decrease in yield and an increase in manufacturing cost.

When the sensitivity and the resolution are adjusted by adjusting the contents of the photosensitive component and the resin component, the thickness of the colored pixel of each hue is different, and a step is generated. If a step occurs between the colored pixels, the flatness of the color filter is impaired. If a voltage is applied between the electrodes during mounting, a difference occurs in the voltage, causing display failure. In a liquid crystal display, a voltage is applied to the liquid crystal to align the liquid crystal molecules, but the voltage that maximizes the contrast changes depending on the cell gap. If the thickness of each colored pixel of the color filter is different, the cell gap changes, and the optimal voltage changes for each color. Therefore, there arises a problem that the contrast is lowered and the color balance at the time of off is lost. Furthermore, if there is a step between the colored pixels of the color filter, the rubbing process in which the surface of the alignment film is rubbed in a certain direction and the liquid crystal molecules are arranged in the rubbing direction does not rub the pixel boundary portion, and the liquid crystal is aligned with the liquid crystal. Failure occurs and the contrast is reduced.

Recently, the present inventors have conceived a method of manufacturing a color filter by removing a colored coating film formed on a substrate by irradiating it with a laser beam while leaving a portion serving as a pixel. did. In this method, a colored coating film of a first color is formed on a substrate, and a portion other than a region serving as a pixel of the first color is irradiated with a laser beam to evaporate only a portion to be irradiated. A colored pixel is formed, and then a colored coating film of the second color is formed on the entire surface of the substrate from above the colored pixel of the first color, and a laser beam is applied to a portion other than a region to be the colored pixel of the second color. Evaporating the coating film on the irradiated portion, and controlling the output of the laser light (the amount of irradiation energy) (including the control of the number of shots of the pulsed light) to leave the colored pixel of the first color. The second color pixel is formed by evaporating the second color coating film coated thereon, and the third color pixel is formed in the same manner.

By employing this laser processing method, the above-mentioned problems associated with the use of a photosensitive resin can be solved, and a high-definition color filter can be manufactured. However, this laser processing method has the following problems. That is, in the laser processing method, a colored coating film and a colored pixel are usually formed using a colored composition containing an organic pigment, a binder, and a solvent as essential components. However, when an organic pigment is used as a coloring agent, spectral characteristics and contrast are inferior to those when a dye is used. On the other hand, when a dye is used as a colorant, heat resistance is inferior to a case where an organic pigment is used. In addition, when the colored pixel is formed by the laser processing method, the cross-sectional shape is liable to cause a shoulder sag (a slope formed at the end of the evaporated portion of the colored coating film) a as shown in FIG. Display quality on the LCD is reduced.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a color filter which is excellent in spectral characteristics, contrast and heat resistance, has colored pixels with extremely small shoulder sag, and is excellent in display quality by a laser processing method. To provide.
Another object of the present invention is to provide a coloring composition for a color filter which can provide a color filter having such excellent characteristics, and a method for producing a color filter by a laser processing method. The present inventors have conducted intensive studies to overcome the problems of the prior art. As a result, while using a dye as a coloring agent of a coloring composition for a color filter, a thermosetting resin having a curing temperature of 200 ° C. or more as a binder was used. It has been found that the above objects can be achieved by using a binder.

When a dye is used as a coloring agent, a color filter having excellent spectral characteristics and contrast can be obtained. On the other hand, the lack of heat resistance of the dye can be compensated for by using a thermosetting binder having a curing temperature of 200 ° C. or more as a binder, and when forming a colored pixel by a laser processing method, a shoulder is formed. It becomes possible to make dripping extremely small. According to the laser processing method, compared to the photolithographic method, since the colored pixel forming step is a dry process, there is no need for waste liquid treatment, there is no contamination in the wet process,
There are advantages in that pixel defects can be reduced, the yield of color filters can be improved, and photosensitivity is unnecessary, so that the cost is low. The present invention has been completed based on these findings.

[0010]

According to the present invention, in a coloring composition for a color filter containing a colorant, a binder, and a solvent as essential components, the colorant is a dye, and the binder is at 200 ° C. or higher. A coloring composition for a color filter, which is a thermosetting binder having a curing temperature of Further, according to the present invention, in a color filter in which a plurality of colored coating films having different hues are formed in a pattern on a transparent substrate, each colored coating film is a dye, a heat having a curing temperature of 200 ° C. or more. There is provided a color filter formed using a coloring composition containing a curable binder and a solvent as essential components.

Further, according to the present invention, (A) a coating film made of the first-colored composition is formed on the transparent substrate, and then a laser beam is applied to a portion other than the region to be the first-colored pixel. Forming a colored pixel of the first color by irradiating the film to be irradiated and evaporating the coating film in the irradiated portion;
A coating film made of the second color composition is formed on the entire surface of the substrate including the color pixel, and then a laser beam is applied to a portion other than the region where the second color pixel is formed, so as to be irradiated. The second color pixel is formed by evaporating the coating film of the second color. At this time, the output of the laser beam is controlled to leave the first color pixel and the second color pixel coated thereon. Evaporating the coating film of (C) and, if necessary,
A method for manufacturing a color filter in which at least two colored pixels are formed in a pattern, including the steps of forming colored pixels of the required number of colors after the third color by the same steps as the step (B). In the above, there is provided a method for producing a color filter, wherein a coloring composition containing a dye, a thermosetting binder having a curing temperature of 200 ° C. or more, and a solvent as essential components is used as a coloring composition for each color. You.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

(Coloring composition) The coloring composition of the present invention is a dye, 200 ° C
It contains a thermosetting binder having the above curing temperature and a solvent as essential components. 1. Dye The dye used in the present invention is not particularly limited, but an organic solvent-soluble dye and an acid dye are preferable. Multiple dyes may be blended to achieve the desired color. The primary hues of red, green and blue are usually obtained by adjusting the hue of the dye. Hereinafter, typical dyes used in the present invention will be exemplified. The numerical display is a color index. Solvent Red (7, 8, 46, 68, 90,
91, 92, 109, 111, 118, 119, 12
2, 125, 127, 130, 132, 207), Solvent Yellow (21, 25, 33, 42, 56, 6)
3, 79, 82, 83, 88, 89, 138, 146,
163), Solvent Orange (11, 23, 59,
62), Solvent Green (3, 25), Solvent Blue (4, 5, 14, 25, 35, 37, 38,
44, 45, 48, 49, 67, 70), azide blue (9, 40), solvent violet (13, 1
4, 23, 24), azide violet (17, 4
9).

2. Binder As the binder used in the present invention, a binder having high heat resistance is used in order to supplement the heat resistance of the dye. For this purpose, a thermosetting binder having a curing temperature of 200 ° C. or higher is used. The curing temperature is preferably 230 ° C. or higher.
Examples of such a high heat-resistant binder material include polyimide, polybutadiene, aromatic polyamide,
Highly heat-resistant polymers (including precursors) such as polybenzimidazole are mentioned. As the inorganic material, a sol-gel glass made of a metal alkoxide may be used. Organic /
Examples of the inorganic hybrid material include silicone. In general, the high heat-resistant binder as described above also has hardness at a temperature near room temperature, so that it can sufficiently withstand the explosive impact force at the time of evaporation due to laser beam irradiation, and suppresses shoulder dripping of colored pixels. Is done. In addition, such a high heat-resistant binder has a high binding energy between molecules, and is originally difficult to evaporate by irradiation with laser light,
By containing a dye that is a laser light absorption source,
Easily transpired.

3. Solvent As the solvent, a solvent having good compatibility with the dye and the binder is appropriately selected. Not only a single solvent but also a mixed solvent can be used. Preferred solvents include, for example, N-methyl-2-pyrrolidone, diethylene glycol dimethyl ether and the like. If necessary, various additives such as a leveling agent, an antifoaming agent, a fluidity improving agent, and a dispersant may be added to the coloring composition of the present invention.

(Method for Producing a Color Filter) A method for producing a color filter using the coloring composition of the present invention will be described with reference to FIG. (A) First Step As shown in FIG. 2A, a first color coating film 2 is formed on a substrate 1. The substrate is usually transparent, and a glass substrate, a resin substrate such as a film, or the like is used. A substrate on which a black matrix is formed can also be used as the substrate. The black matrix fills or covers the gaps between the colored pixels with a light-shielding substance to improve the contrast of the color filter. Examples of the material of the black matrix include chromium, chromium oxide, carbon black, graphite, and a resin composition mixed with a light-shielding substance. Alternatively, a black matrix may be formed by overlapping pixels of two or more colors by using a transparent substrate. Here, the first color is one of the three primary colors required for the color filter, and the second color is hereinafter referred to as the second color.
The eye color and the third color are the remaining colors, respectively. Usually, red, green, and blue (abbreviations, R, G, and B, respectively) are used as the three primary colors.

The formation of the colored coating film is carried out by applying the coloring composition to a substrate and drying it. As a coating film forming method,
Examples include spin coating, roll coating, bar coating, and dipping. The thickness of the coating film varies depending on the concentration of the dye, but is usually 0.5 to 2 μm. After application, the coating is dried and cured. Usually, both drying and curing are performed by baking. As an example of the method, there is a method of placing on a hot plate or placing in an oven.
The baking conditions are appropriately selected depending on the vapor pressure of the solvent during drying and the heat resistance of the binder during curing, but the drying temperature is from room temperature to 200 ° C., and the curing temperature is from 200 ° C. to 300 ° C. Is suitable. As shown in FIGS. 2B and 2C, the colored film 2 thus obtained is irradiated with a laser beam 3 on a portion other than the region where the first colored pixel 5 is formed. The illuminated portion evaporates to form the first colored pixel 5. The size of the colored pixel formed here is about 100 × 300 μm, and the pixel interval is about 30 μm.
It is. However, it is not limited to this.

The laser used here must have a sufficiently short wavelength so that the coating film is irradiated with a laser beam and evaporates. Therefore, an excimer laser having a wavelength in the ultraviolet region is preferable. Excimer lasers used include XeCl, KrF and ArF. However, even if the wavelength is infrared light such as a CO ₂ or YAG laser, it is possible to obtain the wavelength by using the second and third harmonics by using a nonlinear optical material. In this case, the laser light must have a sufficient energy density. The energy density of the laser beam is usually 0.2 to 3 J / cm ² , and particularly preferably 0.5 to ² J / cm ² . If the energy density is too high, not only the coating film but also the underlying substrate will evaporate. If the energy density is too low, the coating will not evaporate. It is necessary to control the output of the laser light to form pixels of the second color and thereafter. At this time, it is desirable that the laser light is pulsed light. Processing control in the depth direction of the coating film becomes possible by the number of shots of the pulse light. Therefore, in the present invention, the control of the output of the laser beam includes not only the control of the irradiation energy but also the control of the number of shots of the pulse light (the number of irradiation pulses).

There are two methods for irradiating a laser beam to obtain colored pixels in a pattern. One is to irradiate a certain area with laser light by surface exposure 3 through a photomask 4 as shown in FIG.
The substrate is moved by a stage or the like and irradiated with laser light again to form pixels. By repeating this process, colored pixels can be formed on the entire surface of the substrate 1.
In this case, the exposure area is preferably as large as possible because the processing time is shortened and shortened. However, if the area is increased too much, the irradiation energy density becomes small and transpiration does not occur. It is preferable to widen the irradiation area of the laser beam with an energy density at which the evaporation occurs at a minimum. In this method, 1
Since a region where a pixel is formed at a time is large, the entire processing time can be shortened. In another method, a colored pixel is formed by narrowing down a laser beam and scanning it. It is preferable that the size of the spot of the laser beam is at least 30 μm or less in either the vertical or horizontal direction of the spot. As a method of scanning with a laser beam, X
There is a method in which the substrate itself is moved by a Y stage or the like, or laser light is scanned by an optical system. This method does not require a photomask, and is advantageous for fine processing. When an excimer laser is used as a light source, a method using a photomask is more advantageous in order to take advantage of its surface light source characteristics. As described above, the first colored pixel 5 is formed.

(B) Second Step As shown in FIG. 1D, the coloring composition of the second color is applied to the first color.
It is applied to the entire surface of the substrate on which the color pixels 5 are formed and dried to form a second color coating film 6. At this time, due to the fluidity of the coating liquid, the thickness of the second color coating film 61 on the first color pixel 5 is usually smaller than the thickness of the second color coating film 6 on the substrate which is a concave portion. . In this case, the better to the coating film thickness d ₂ on the substrate of the second color and slightly thinner than the coating thickness d ₁ of the first color is easy to align the pixel thickness, the ease of process control Considering that the viscosity of the coating liquid is uniform, the coating may be performed under the same conditions. In this case, the first color and the second color often have the same thickness.

Next, as shown in FIGS. 2 (e) and 2 (f), the laser beam 3 is applied to a region other than the region where the second color pixel is formed, in the same manner as when the first color pixel is formed. To form colored pixels 7 of the second color. Here, the depth of evaporation of the second color coating per one shot of the laser pulse, that is, the etch rate r ₂ is measured in advance, and the film thickness d ₂ of the second color coating is measured. The number n of shots required to evaporate the second color coating film 6 on the substrate is obtained from (Equation 1) n = d ₂ / r ₂ (Equation 1), and laser light pulses are irradiated by the number of shots. Unnecessary second color coating on the substrate is evaporated.

At this time, the thickness d ₂ ′ of the second color coating 61 on the first color pixel 5 is usually smaller than the thickness d ₂ of the second color coating 6 on the substrate. Therefore, the pixel 5 of the first color is exposed before the laser light pulse is irradiated for all shots. Therefore, the evaporation rate r ₁ of the first color coating film with respect to the laser beam is made sufficiently smaller than the evaporation rate r _{2 of} the second color coating film to minimize the amount of evaporation of the first color pixels 5. As a result, the thicknesses of the pixels of the first color and the second color can be made uniform. At this time, the thickness of the pixel is d _{2 for} the second color and d ₁ ′ represented by (Equation 2) for the first color, which is slightly smaller than d ₁ . d ₁ ′ = d ₁ − (d ₂ −d ₂ ′) · (r ₁ / r ₂ ) (Equation 2)

From the equation (2), the transpiration rate r ₁ of the first color coating film with respect to the laser beam is made sufficiently smaller than the transpiration rate r _{2 of} the second color coating film to obtain the first color and the second color coating film. It can be seen that the amount of reduction in the pixels of the first color when the coating thickness of the color is equal can be minimized. In this case, the evaporation rate of the first color coating film with respect to the laser beam is preferably one-tenth or more and six tenths or less, particularly one-fifth or more of the evaporation rate of the second color coating film. Less than one third is more preferred. If it is larger than 6/10, the amount of transpiration of the exposed first color pixel is large, and the step between the first color and the second color pixel becomes large. If the ratio is smaller than 1/10, the level difference between the pixels of the first color and the second color is sufficiently small. However, when forming the pixels of the first color in the first step, it is difficult to evaporate. It costs.

On the other hand, in order to make the pixel thicknesses of the first color and the second color after processing uniform, it is sufficient to substitute d ₁ ′ = d ₂ in (Equation 2). Then, d ₁ may be set as (Equation 3) d ₁ = d ₁ + (d ₂ −d ₂ ′) · (r ₁ / r ₂ ) (Equation 3). Also in this case, the evaporation rate r ₁ of the first color coating film with respect to the laser beam is made sufficiently smaller than the evaporation rate r _{2 of} the second color coating film so that the thickness of the first color coating film becomes minimum. Material cost can be reduced.

(C) Third Step Next, as shown in FIG.
Is formed in the same manner as the first and second color coating films. FIG.
As shown in (h) and (i), in the same manner as when forming the second color pixel, the laser light 3 is irradiated to the area other than the area where the third color pixel is formed, and Is formed. In this step, only the third color coating film 81 on the first and second color pixels is evaporated, and the thickness d ₃ ′ of the third color film is determined based on the fluidity of the coating liquid. It is smaller than the coating thickness d ₃ on the substrate. Therefore, by adjusting d ₃ to the thickness of the colored pixels of the first color and the second color, the thicknesses of the pixels of the three colors can be easily made uniform. For this purpose, the depth of transpiration per laser pulse shot, that is, the etch rate is measured in advance, and the film thickness of the third color coating film is measured to make the pixel thicknesses of the three colors uniform. Find the required number of shots, irradiate pulses for that number of shots,
Only the color coating film of the third color on the first color and the second color, or in some cases, the color pixels of the first color and the second color are evaporated. As described above, _three colored pixels in which the thickness of each colored pixel is substantially equal to d ₃ can be formed on the substrate, and as a result, as shown in FIG. Color filters can be easily obtained.

(Function) According to the present invention, since a dye is used as a colorant, the spectral characteristics and contrast when a colored pixel is formed are remarkably superior to those using a pigment. Further, since a material having excellent heat resistance is used as the binder and the dye is dispersed therein, the dye does not fade even when the coating film is cured at a high temperature of 200 ° C. or higher. In addition, since the composition has passed a high temperature of 200 ° C. or more during curing, the heat resistance as a colored pixel can be maintained even if it is subjected to a further thermal cycle. At the same time, since the binder also has hardness, it can withstand an explosive impact force at the time of evaporation and the shoulder droop of each colored pixel can be made extremely small.

[0026]

EXAMPLES Preferred embodiments of the present invention will now be described more specifically with reference to examples and comparative examples. [Example 1] (1) Preparation of coloring composition Red (R) Solvent Red 132 6% by weight Solvent Yellow 897% by weight Polyamic acid (pyromellitic dianhydride and oxydianiline were reacted) 17% by weight-N-methyl-2-pyrrolidone (NMP) 40% by weight-Diethylene glycol dimethyl ether (diglyme) 30% by weight Green (G)-Solvent Blue 38 10% by weight-Solvent Yellow 146 8% by weight-Polyamic Acid (a reaction of benzophenonetetracarboxylic dianhydride with 16% by weight of 4-aminophenylsulfone) N-methyl-2-pyrrolidone 37% by weight Diethylene glycol dimethyl ether 29% by weight Blue (B) Solvent Blue 38 2% by weight・ Blue 496% by weight ・ Polyamic acid (reacted benzophenonetetracarboxylic dianhydride with 14% by weight 4-aminophenylsulfone) ・ N-methyl-2-pyrrolidone 32% by weight ・ Diethylene glycol dimethyl ether 46% by weight The mixture of each color was uniformly dissolved by stirring for several hours. Undissolved material was removed by passing through a filter.

(2) Preparation of Colored Coating Film Each of the above coloring compositions was spin-coated on a glass substrate to form a coating film having a thickness of 1 μm. Each coating was baked on a hot plate at 100 ° C. for 90 seconds. Each coating was then baked in a convection oven at 250 ° C. for 1 hour. Polyamic acid is a polyimide precursor and is imidized by baking.

(3) Evaluation of film Spectral characteristics: Micro color analyzer (Tokyo Denshoku Co., Ltd.)
TC-1800M), CIE color coordinates x,
y and the tristimulus value Y were measured. Contrast: A glass substrate with a colored coating film was sandwiched between two polarizing plates and placed on a light box. When the front luminance was measured with a luminance meter (LS-110 manufactured by Minolta Co., Ltd.),
Luminance (parallel to the polarization direction of the polarizer) / luminance (perpendicular to the polarization direction of the polarizer) was defined as contrast. Heat resistance: After baking at 230 ° C. for 1 hour in a convection oven, color characteristics before and after the baking were measured by a micro color analyzer, and a color difference ΔE (u, v) was calculated. If ΔE <3,
Passed. Laser workability: A 1 μm thick colored coating film is coated with a KrF excimer laser (reduction magnification 10 times, irradiation intensity 1 J / c)
m ² ), the size of the shoulder sag when processed into a pattern of 100 μm × 300 μm is defined as shown in FIG. 1A. The cross-sectional shape of the coating film was measured with a stylus type surface roughness meter (DEKTAK manufactured by Sloan). Table 1 shows the results.

[0029]

[Table 1]

Example 2 (1) Preparation of Coloring Composition Red (R) • Solvent Red 132 6% by weight • Solvent Yellow 82 7% by weight • Tetraethoxysilane 17% by weight • Hydrochloric acid aqueous solution (0.036 wt.) 8% by weight ・ 62% by weight of 1-butanol Green (G) ・ Solvent Blue 449% by weight ・ Solvent Yellow 146 9% by weight ・ Tetraethoxysilane 16% by weight ・ Hydrochloric acid aqueous solution (0.036% by weight) 7% -1-butanol 59% by weight Blue (B)-Solvent Blue 44 2% by weight-Solvent Blue 496 6% by weight-Tetraethoxysilane 14% by weight-Hydrochloric acid aqueous solution (0.036wt%) 7% by weight-1- Butanol 71% by weight The mixture of each color described above is stirred for several hours to dissolve uniformly. It was. Undissolved material was removed by passing through a filter.

(2) Preparation of Colored Film Each of the above colored compositions was vitrified by a sol-gel method. That is, each coloring composition was spin-coated on a glass substrate to form a coating film having a thickness of 1 μm. Each coating was placed on a hot plate at 100 ° C for 90
Bake for 2 seconds. Each coating was then placed in a convection oven for 24 hours.
It was baked and hardened by baking at 0 ° C. for 1 hour. Table 2 shows the evaluation results of the films.

[0032]

[Table 2]

Example 3 (1) Production of Color Filter A coating film was formed on a 10 cm square alkali-free glass substrate using the coloring composition B of Example 1 as a first color.
At this time, the thickness of the dried coating film was 1.01 μm.
The obtained colored coating film of B is irradiated with a KrF excimer laser [L5837: Hamamatsu Photonics Co., Ltd.] to a portion other than the region to be a colored pixel, and the irradiated portion evaporates.
Of colored pixels were formed. At this time, a 100 × 300 μm B pixel was formed by reducing the pattern of the photomask of laser light to one-tenth by the reduction optical system and irradiating the laser light while moving the substrate by the XY stage. The energy density of the laser at this time was 1 J / cm ² . Next, the coloring composition G of Example 1 was applied from above the substrate on which the pixels of B were formed under application conditions such that the thickness was smaller than that of B, thereby obtaining a coating film of G. At this time, the film thickness of G was 0.8 μm on the substrate.
Thus, it was 0.5 μm on the B pixel. That is, B
And G were found to have a thickness of 1.51 μm. The vaporization depth per unit pulse of the coating film of B at a laser power of the intensity to evaporate the coating film of G on the substrate in one shot, that is, the etch rate was previously measured, and G was 0.8 μm / pulse. B was 0.56 μm / pulse. Adjusting the intensity of the laser beam so that unnecessary G on the substrate evaporates in one shot, and moving the XY stage, irradiate one shot at a time to a part other than the area where the G pixels are formed, and Then, a 100 × 300 μm G pixel was formed. At this time, the thickness of the pixel was 0.8 μm for both G and B.

Finally, the coloring composition R of Example 1 was formed under the same conditions as for G. At this time, the thickness of the R coating film was 0.8 μm on the substrate, and 0.5 μm on both the B and G coating films. That is, two layers of B and R and G
And R were both 1.3 μm. 1
By adjusting the intensity of the laser beam so as to evaporate unnecessary R in the shot, and moving the XY stage, irradiate one shot at a time to a portion other than the region where the R pixel is formed,
R 100 × 300 μm pixels were formed on the entire substrate.
The thickness of each pixel of the color filter thus manufactured was 0.8 μm for each of R, G, and B. At this time, the shoulder droop of the colored pixel was small, and the display quality was not affected.

Comparative Example 1 (1) Evaluation of Film Each color of a conventionally known commercially available colored composition [RW-301 (R, G, B) manufactured by Sekisui Fine Chemical Co., Ltd.] was spun on a glass substrate. Coating was performed to form a coating film having a thickness of 1 μm. Each coating was baked on a hot plate at 80 ° C. for 60 seconds. Each coating was then cured by baking in a convection oven at 150 ° C. for 30 minutes. Table 3 shows the evaluation results of the films.

[0036]

[Table 3]

(2) Production of Color Filter A color filter was produced in the same manner as in Example 3 using each of the coloring compositions described above. Dropped. That is, when the screen was made brighter, the whole became whitish, and when it became darker, the whole became blackish.

[0038]

According to the present invention, the following remarkable effects can be obtained. (1) Since the colored pixel forming process is a dry process,
No waste liquid treatment is required unlike the photoresist method. In addition, it is possible to reduce pixel defects without mixing impurities in the wet process. As a result, the yield of the color filters can be improved. (2) The coloring composition is inexpensive because it does not require photosensitivity. (3) A color filter having excellent spectral characteristics, contrast, and heat resistance can be manufactured, and furthermore, shoulder droop of colored pixels due to laser processing can be extremely reduced, so that a liquid crystal display with good display quality can be obtained. An apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a shape of a colored pixel formed by a laser processing method.

FIG. 2 is a schematic diagram of a color filter manufacturing process by a laser processing method.

[Explanation of symbols]

 a: Size of shoulder dripping of colored pixel 1: Substrate 2: First color coloring film 3: Laser light 4: Photomask 5: First color pixel 6: Second color coloring film (on substrate) 61: First color Second color paint film (on pixel) 7: Second color pixel 8: Third color paint film (on substrate) 81: Third color paint film (on pixel) 9: Third color pixel

Claims (3)

[Claims] 1. A color filter coloring composition containing a colorant, a binder and a solvent as essential components, wherein the colorant is a dye and the binder is at 200 ° C.
A coloring composition for a color filter, which is a thermosetting binder having the above curing temperature. 2. A color filter in which a plurality of colored films having different hues are formed in a pattern on a transparent substrate, wherein each of the colored films is a dye, a thermosetting binder having a curing temperature of 200 ° C. or more. And a color filter formed using a coloring composition containing a solvent as an essential component. (A) forming a coating film comprising a first-colored composition on a transparent substrate;
A step of forming a first color pixel by irradiating a portion other than a region to be a color pixel to evaporate a coating film of a portion to be irradiated, and (B) a substrate including the first color pixel Forming a coating film of the second color composition on the entire surface, and then irradiating the laser light to a portion other than the region serving as the second color pixel to evaporate the coating film of the irradiated portion. Thereby, a colored pixel of the second color is formed.
A step of controlling the output of the laser beam to evaporate the coating film of the second color coated thereon while leaving the colored pixel of the first color; and (C) optionally, the step (B) In the method for manufacturing a color filter in which at least two colored pixels are formed in a pattern, the method includes the steps of forming colored pixels of a required number of colors from the third color onward by the same steps as described above. A method for producing a color filter, comprising using a coloring composition containing a dye, a thermosetting binder having a curing temperature of 200 ° C. or higher, and a solvent as essential components.