JPH10239515A - Manufacture of color filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a protruding defect and prevent the generation of common short circuit at the time of laminating a color filter and a TFT array, by forming a black matrix and picture element images of red, green and blue colors on a glass substrate rid of glass cullet of a specified size or larger. SOLUTION: After a photopolymerized composition with black material such as carbon black dispersed is applied onto a non-alkali glass substrate, treatment of heat drying, image exposure, development and heat curing is applied to form a black matrix. Photopolymerized compositions with red, green, and blue dye pigments respectively dispersed are used and applied to a black matrix-formed face, and treatment of heat drying, image exposure and heat curing is applied to form picture element images of the respective colors. In this case, a glass substrate rid of glass cullet of 5μm or more, disirably 3μm or more, using brush cleaning and ultrasonic cleaning jointly in an alkaline washing solution, is used as the glass substrate.

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, and more particularly, to the use of a specific glass substrate to reduce the number of projection defects, and thus to cause the color filter to be stuck to a TFT array. The present invention relates to a method of manufacturing a color filter that solves the problem of common shorts.

[0002]

2. Description of the Related Art A color filter is manufactured by forming a black matrix and pixel images of red, green and blue colors on a glass substrate. Then, it is disposed to face a driving substrate provided with a thin film transistor array and the like, and is used when a liquid crystal is accommodated between the substrates to assemble a liquid crystal cell.

[0003]

However, one of the problems in the method of manufacturing a color filter is a pixel defect. Pixel defects are roughly classified into three types: white defects, black defects, and protrusion defects. The white defect and the black defect are regarded as defective if there is a defect that can be visually confirmed, and the projection defect is the most hated defect to cause a common short at the time of bonding with the TFT array. It is required that no defect of 5 to 10 μm be present on the entire surface of the color filter.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to reduce the number of protrusion defects and to solve the problem of a common short circuit caused when a color filter is bonded to a TFT array. It is to provide a manufacturing method of.

The present inventor has conducted intensive studies in order to achieve the above object, and as a result, obtained the following findings. That is, the glass substrate for a color filter is usually shipped after being polished by a glass maker. Is caused. Moreover, it is extremely difficult to completely remove a glass cullet that is large enough to cause a common short, and can be efficiently removed only by a specific cleaning method.

[0006]

SUMMARY OF THE INVENTION The present invention has been completed based on the above findings, and its gist is to form a black matrix and a pixel image of each color of red, green and blue on a glass substrate. In the method for producing a color filter, a glass substrate from which a glass cullet of 5 μm or more is removed is used as the glass substrate.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
First, for convenience of description, an outline of a method for manufacturing a color filter will be described. There are pigment dispersion methods, dyeing methods, electrodeposition methods, printing methods, etc., as color filter production methods. Widely adopted. As a method for forming a black matrix, a method using a photosensitive resin in which a black material is dispersed has been proposed in addition to a method using a metal light-shielding film. According to this method, equipment such as sputtering and chromium disposal treatment are not required, and there is an advantage that significant cost reduction can be realized.

Accordingly, in the present invention, after the photopolymerizable composition in which the black material is dispersed is applied on a glass substrate,
Each step of heat drying, image exposure, development and heat curing is performed to form a black matrix, and then, using a photopolymerizable composition in which red, green, and blue materials are respectively dispersed, the above black matrix formation is performed. A method of forming each pixel image of each color by performing each processing of coating, heat drying, image exposure, and heat curing on the surface is preferably adopted.

As the glass substrate, non-alkali glass is preferably used. The surface of the glass substrate is subjected to a corona discharge treatment, an ozone treatment, a silane coupling agent or a urethane to improve the surface properties such as adhesiveness. A thin film forming treatment of various polymers such as a polymer can be performed. The thickness of the glass substrate is generally in the range of 0.05 to 10 mm, preferably 0.1 to 7 mm. Further, when performing a thin film forming process of various polymers, the film thickness is usually 0.01 to
The range is 10 μm, preferably 0.05 to 5 μm.

In the present invention, carbon black is usually used as the black material, and red, green, and blue dyes and pigments are usually used as the other color materials. White pigments, fluorescent pigments and the like can also be used.

Specific examples of carbon black and dyes and pigments include Mitsubishi Carbon Black M1000, Mitsubishi Carbon Black MA-100, Mitsubishi Carbon Black # 40,
Victoria Pure Blue (42595), Auramine O
(41000), Catillon Brilliant Flavin (Basic 13), Rhodamine 6 GCP (45160), Rhodamine B (45170), Sakuranin OK 70: 1
00 (50240), Erioglaucine X (4208)
0), NO. 120 / Lionol Yellow (2109
0), Lionol Yellow GRO (21090), Shimura First Yellow GRO (21090), Shimura First Yellow 8GF (21105), Benzidine Yellow 4J-564D (21095), Shimla First Red 4015 (12355), Lionol Red 7B4401 (15850). ), First Gen Blue J
GR-L (74160), Lionol Blue SM (26
150), Lionol Blue ES (Pigment Blue 1)
5: 6, Pigment Blue 1536), Lionogen Red GD (Pigment Red 168, Pigment Red 108), Lionol Green 2YS (Pigment Green 36) and the like (the numbers in parentheses above indicate the color index (C.I. I.)).

The amount of the color material dispersed in the photopolymerizable composition is usually in the range of 10 to 70% by weight, preferably 20 to 60% by weight based on the total solid content. The composition is required to have a high adhesiveness to a glass substrate and a function of giving a high quality color material pixel image in such a state of a high color material content.

In the present invention, the photopolymerizable composition includes, in addition to the color material, a photopolymerization initiation system that absorbs light to generate a radical, and an addition-polymerizable ethylenic polymer that is induced to polymerize by the radical. A compound having at least one saturated double bond (hereinafter referred to as “ethylenic compound”),
Further, in order to improve the photopolymerizable layer such as compatibility, film forming property, developing property, adhesiveness, etc., it contains an organic polymer substance as a binder.

The above-mentioned photopolymerization initiation system includes the following compounds. That is, since the black photopolymerizable layer is image-exposed through the pattern mask from above the photopolymerizable layer, the photopolymerization initiation system used for the black photopolymerizable composition is sensitive from ultraviolet to visible. Are appropriately used, and an exposure light source corresponding thereto is used for image exposure.

In each of the red, green, and blue photopolymerizable layers, red, green, and blue photopolymerizable layers are also exposed to light through a pattern mask of each color or by other methods, so that red, green, and blue are interposed between the black matrix patterns.
In order to form green and blue pixel image patterns, as in the case of the black matrix pattern, the photopolymerization initiation system is a compound having sensitivity from ultraviolet to visible light, preferably 450 nm or less, more preferably 400 nm or less. Use compounds with sensitivity.

As a photopolymerization initiation system which absorbs ultraviolet light having the above-mentioned wavelength and generates radicals, for example, "Fine Chemical" (March 1, 1991, vol. 20, N.K.)
o. 4), pages 16 to 26, dialkylacetophenones, benzoin, thioxanthone derivatives and the like, JP-A-58-403023, and JP-B-45-3.
No. 7377, hexaarylbiimidazole type, S-trihalomethyltriazine type, JP-A-4-22
1958 and JP-A-4-219756, a system in which a titanocene is combined with a xanthene dye, an addition-polymerizable ethylenically saturated double bond-containing compound having an amino group or a urethane group, and the like.

The ethylene compound may be any of a monomer and a polymer having an ethylenically unsaturated double bond in a side chain or a main chain. Specifically, an ester of an aliphatic polyhydroxy compound and an unsaturated carboxylic acid (for example,
Ethylenic compounds such as ethylene glycol diacrylate, pentaerythritol triacrylate, and dipentaerythritol hexaacrylate) or monomers of acrylate or methacrylate are preferably used.

The organic polymer substance used as a binder of the photopolymerizable composition includes methyl (meth) acrylic acid,
Examples include polymers composed of alkyl esters of (meth) acrylic acid such as benzyl (meth) acrylic acid, vinyl acetate, and acrylonitrile.
From the viewpoint of substrate adhesion, a copolymer containing a copolymerizable monomer having a phenyl group such as styrene, α-methylstyrene, or benzyl (meth) acrylate, or 1 to 50 mol% of epoxy (meth) ) Acrylate-added reactants are preferably used.

The amounts of the above components are as follows.
That is, the photopolymerizable starting system is usually 0.1 to 40% by weight, preferably 0.2 to 30% by weight, and the ethylenic compound is usually 20 to 90% by weight, preferably 30 to 80% by weight, and the organic polymer substance is usually 10 to 80% by weight, preferably 2 to 80% by weight.
0 to 60% by weight. In the present invention, the photopolymerizable composition may contain 0.1 to 10% by weight of a silane coupling agent on the same basis as described above.

The above photopolymerizable composition is used as a coating solution prepared with a suitable solvent. As the solvent, methyl cellosolve, ethyl cellosolve, diethylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl ethyl ketone,
Examples include methyl isobutyl ketone, cyclohexanone, toluene, methanol, butanol, tetrahydrofuran and the like.

In the formation of the red, green and blue pixel image patterns, in order to prevent a decrease in sensitivity of the photopolymerizable layer due to oxygen during the exposure of the photopolymerizable layer, a polyvinyl film is formed on the photopolymerizable layer. An oxygen barrier layer such as an alcohol layer may be applied. When the oxygen barrier layer is not provided, the monomer having an aromatic hydrogen group is usually used as a copolymerizable component of the photopolymerizable composition in an amount of 5 to 50 mol% (preferably 10 to 50 mol%).
To 30 mol%), or the use of an organic polymer substance in the photopolymerizable composition.
It is preferable that the diazo compound described in JP-A-5-195453 and JP-A-5-19453 is contained in an amount of 1 to 20% by weight (preferably 2 to 10% by weight). As a result, a decrease in sensitivity due to oxygen can be suppressed, and an oxygen blocking layer can be eliminated.

In the formation of the black matrix,
After the photopolymerizable composition (coating liquid) in which the black material is dispersed is applied on a glass substrate, each of heating, drying, image exposure, development, and heat curing is performed. Then, in a preferred embodiment of the present invention, most of the solvent in the coating film is removed by performing preliminary drying prior to the heat drying treatment.

As the coating device, a spinner, a wire bar, a flow coater, a die coater, a roll coater,
A spray or the like is used. Pre-drying conditions are appropriately selected depending on the type of the solvent.
The duration is from 2 seconds to 5 minutes, preferably from 30 seconds to 3 minutes at a temperature of 50-70 ° C.

The heating and drying conditions are preferably higher than the preliminary drying temperature and at a temperature of 50 to 160 ° C. for 15 seconds to 10 minutes, and at a temperature of 70 to 130 ° C. for 15 seconds to 30 seconds to 5 minutes. Is particularly preferred. In addition, the thickness of the photopolymerizable layer (dried coating film) after drying is usually 0.5 to 3 μm,
Preferably, it is in the range of 1-2 μm.

The image exposure is performed by introducing a negative matrix pattern on the black photopolymerizable layer and irradiating an ultraviolet or visible light source through the mask pattern. At this time, if necessary, in order to prevent a decrease in sensitivity of the photopolymerizable layer due to oxygen, exposure may be performed after forming an oxygen barrier layer such as a polyvinyl alcohol layer on the photopolymerizable layer.

The development is carried out using an alkaline developer by a method such as immersion development, spray development, brush development, or ultrasonic development. Thereby, a black matrix pattern is formed on the glass substrate. Examples of the alkali developer include inorganic alkali agents such as sodium carbonate, potassium carbonate, sodium silicate, potassium silicate, sodium hydroxide, and potassium hydroxide; and organic solvents such as diethanolamine, triethanolamine, and tetraalkylammonium hydroxide salts. Use an aqueous solution containing an alkali agent and, if necessary, a surfactant, a water-soluble organic solvent, a low molecular compound having a hydroxyl group or a carboxylic acid group, etc. for the purpose of improving image quality and shortening the development time. Can be done.

Examples of the surfactant include sodium naphthalenesulfonate group, anionic surfactant having a sodium benzenesulfonate group, nonionic surfactant having a polyalkyleneoxy group, and cationic surfactant having a tetraalkylammonium group. No. Examples of the water-soluble organic solvent include ethanol, propion alcohol, butanol, methyl cellosolve, butyl cellosolve, ethylene glycol, propylene glycol, and propylene glycol monomethyl ether.
Examples of the low molecular weight compound having a hydroxyl group or a carboxy group include 1-naphthol, 2-naphthol, pyrogallol,
Benzoic acid, succinic acid, glutaric acid and the like can be mentioned.

The temperature as a developing condition is usually from 20 to 40.
It is selected from the range of ° C. The conditions for the heat curing treatment are usually 1
It is 5 to 60 minutes at 00 to 280 ° C. This allows
The formation of the black matrix image ends.

In forming the red, green, and blue pixel image patterns, the black matrix forming surface obtained by the above method is used by using each photopolymerizable composition in which red, green, and blue materials are dispersed. Then, the respective processes of coating, heating and drying, image exposure, development, and thermosetting are performed to form a pixel image of each color.

That is, after the photopolymerizable composition containing one of red, green and blue is applied to the entire surface of the glass substrate on which the black matrix is formed, pre-drying is performed in the same manner as in the case of forming the black matrix. Thereafter, a heat-drying treatment is performed to form a photopolymerizable layer. After that, an exposure process is performed through a pixel image pattern mask, an alkali development and a thermosetting process are performed, and a first color pixel image is formed between black matrix images. Hereinafter, by performing the same operation, the pixel images of the second color and the third color are sequentially formed between the black matrix images.

Light sources used for the above image exposure include lamp light sources such as xenon lamps, halogen lamps, tungsten lamps, high-pressure mercury lamps, metal halide lamps, medium-pressure mercury lamps, low-pressure mercury lamps, argon ion lasers, YAG lasers, and excimer lasers. And a laser light source such as a nitrogen laser. These light sources include:
An optical filter can be used as appropriate according to the required wavelength range of the irradiation light.

A color filter produced by forming black, red, green, and blue pixel images on a glass substrate forms an ITO (transparent electrode) on the image in this state, and forms one of the components of a color display. Although it is used as a part, a top coat layer of polyamide, polyimide, or the like can be provided on the image as needed to enhance surface smoothness and durability.

A feature of the present invention resides in that, in the above-described method for producing a color filter, a glass substrate from which a glass cullet of 5 μm or more has been removed is used. The size of the glass cullet to be removed is preferably 4 μm or more, more preferably 3 μm or more.
Such removal of the glass cullet is not always easy, and can be achieved by brush cleaning and ultrasonic cleaning in an alkaline cleaning liquid, and cannot be achieved by a single treatment of these cleanings.

NaOH or KOH is preferably used for preparing the alkaline cleaning solution. PH of alkaline cleaning solution
Is not particularly limited, but is preferably 13 or more. The temperature of the alkaline cleaning liquid (cleaning liquid temperature) is usually 3
The temperature is 0 ° C or higher, preferably 40 ° C or higher. Brush cleaning and ultrasonic cleaning can be performed simultaneously or before and after.

The brush cleaning is a cleaning method in which a large number of synthetic fibers are implanted on a peripheral surface of a cylindrical body by a sliding brush. The rotating brushes usually face each other so as to sandwich a passing glass substrate. Are arranged as a set in a shower cleaning device or an immersion tank. As synthetic fibers of the rotating brush, for example, nylon, nylon 6,
Nylon 6, 6, etc. are used, and synthetic fibers are usually 100
It is planted in an arbitrary pattern such as a spiral shape at a density of １，1,000 / cm ² .

The rotating speed of the rotating brush is usually 100 to 50.
0 rpm, and the pressing amount is usually 0.5 to 3 m
m. Here, the pressing amount of the rotating brush means the pressing amount when the tip of the synthetic fiber just touches the glass substrate without bending, and the length when the rotating brush is brought closer to the glass substrate from that position ( mm).

The ultrasonic cleaning is a cleaning method using ultrasonic waves by an ultrasonic vibrator, and the ultrasonic vibrator is disposed between a shower cleaning device and a glass substrate or in an immersion tank. The range of the ultrasonic wave is usually 10 to 100 KHz, preferably 30 to 80 KHz.

The cleaning time in the ultrasonic cleaning and the brush cleaning described above is usually 5 m when expressed by the amount of fluid contact.
It is 1 / cm ² or more, preferably 10 ml / cm ² or more. Here, the fluid contact amount is defined as an amount obtained by dividing the amount of fluid applied to one glass substrate by the area of the support when each of the above-described cleanings is performed by a shower method. When performed, it is defined as the amount obtained by dividing the amount of fluid in the immersion tank by the number and area of glass substrates washed with the fluid.

In the present invention, after the above-described brush cleaning and ultrasonic cleaning, a rinsing cleaning process is performed. As the rinsing fluid, a liquid having a high dissolving power for alkali is preferable. Usually, water is used, and water heated to 30 ° C. or higher is preferable. Shower rinsing,
Running water rinsing, immersion rinsing and the like are preferably employed. The fluid contact amount in the rinsing process is selected from the same range as described above.

In the present invention, a cleaning liquid from which contained foreign matter is removed is used in both of the alkaline cleaning and the rinsing. Preferably, the number of particles having a particle size of 0.2 μm or more is 10 particles / ml or less. Preferably, a washing solution of 5 / ml or less is used. Further, in the present invention, it is preferable that each of the above-mentioned cleaning treatments is performed while the transparent support is introduced one by one into the cleaning area by the transfer means and sequentially transferred.

[0041]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. In the following Examples and Comparative Examples, the following components (1) to (4) shown in Table 1 and the color materials shown in Table 2 were used. Each photopolymerizable coating solution containing each color material has a blending amount shown in the following Table 3, and a paint containing 3.6 weight times zirconia beads (diameter 0.5 mm) with respect to the total amount. It was prepared by performing a dispersion treatment for 7 hours using a shaker. Also,
The measuring methods adopted in the following examples and comparative examples are as follows.

(1) Number of glass cullets: After observing the transmitted light with a CCD camera, performing image processing, and specifying the position and number of foreign substances on the surface by an inspection device capable of automatically identifying foreign substances, optically controlling all foreign substances. Review with a microscope and count the number of glass cullet.

(2) Number of protrusion defects in the color filter:
The reflected light is observed by a CCD camera, image processing is performed, and the number of protrusion defects on the surface is measured by an inspection device that can automatically identify protrusion defects.

(3) Yield of color filter: 100
Inspection device capable of automatically identifying pixel defects (white defect: 100 μm in diameter, black defect: 40 μm in diameter, protrusion defect: 5 μm in height) by observing transmitted / reflected light with a CCD camera for the color filters and performing image processing. , The pixel yield is measured to determine the yield.

[0045]

[Table 1]

[0046]

Embedded image (A: b: c: d = 55: 15: 20: 10 (mol%), Mw: 12,000)

[0047]

Embedded image

[0048]

[Table 2]

[0049]

[Table 3]

Example 1 Alkali-free glass substrate (“AN-63” manufactured by Asahi Glass Co., Ltd.)
5) 400 × 500 × 0.7 mmt) was subjected to brush cleaning and ultrasonic cleaning under the conditions shown in Table 4, followed by rinsing to remove alkali components, followed by air knife drying.
Hot air drying was performed at 200 ° C. for 10 minutes.

For the above-described brush cleaning, an apparatus was used in which a rotating brush was arranged so as to face the glass substrate transport path below the shower cleaning apparatus so as to sandwich the substrate. As the rotating brush, 0.1mmφ ×
A rotating brush in which 15 mm nylon 6,6 was implanted in a spiral at a density of 700 / cm ² was used. The number of rotations is 300 rpm and the pressing amount of the rotating brush is 1.2 mm
And For the above ultrasonic cleaning, a frequency of 50
A device in which an ultrasonic vibrator of Hz was arranged was used.

For the above rinsing, a shower cleaning device using water was used. In any of the washings, the washing temperature was 40 ° C., and the fluid contact amount was 20 ml / c.
It was m ^2. The number of residual glass cullets (≧ 5 μmφ) per 100 glass substrates after the cleaning treatment was determined, and the results are shown in Table 4. In addition, it was confirmed by a separate test that the number of such residual glass cullets corresponds to the number of protrusion defects described later of the color filter to be manufactured.

Next, a black photopolymerizable coating solution was applied to the above glass substrate by a spin coater so that the dry film thickness became 0.7 μm. Then, after drying at 60 ° C for 1 minute,
It was dried by heating at 110 ° C. for 2 minutes. Thereafter, an aqueous solution of polyvinyl alcohol was applied on the photopolymerizable layer so as to have a dry film thickness of 1.5 μm, and then dried to form an oxygen barrier layer.

Next, a width of 30 μm, a length of 330 μm, and a width of 1
Using a negative photomask for a black matrix that is repeated at a pitch of 10 μm,
The exposure processing was performed at an exposure amount of 00 mJ / cm ² . Then, as a development process, polyethyleneoxy-β-naphthyl ether (“Newcol B-1” manufactured by Nippon Emulsifier Co., Ltd.)
0 "), immersed in a developer consisting of an aqueous solution containing 2% by weight of potassium carbonate and 0.5% by weight of potassium carbonate at 25 ° C. for 30 seconds, and then spray-washed at a water pressure of 3 kg / cm ² for 30 seconds. A black matrix was formed. Thereafter, a thermosetting treatment was performed at 200 ° C. for 7 minutes.

Next, each photopolymerizable coating solution containing each of the red, green, and blue coloring materials was used sequentially, and the coating,
Each process of preliminary drying, heating drying, exposure, development, washing with water, and heat curing was performed to form a pattern of each color, and a color filter was manufactured. However, the exposure amount is 500 mJ / c for each color.
It was m ^2. The number of protrusion defects and the yield of the obtained color filter were measured, and the results are shown in Table 4.

Examples 2 to 4 and Comparative Examples 1 to 4 A color filter was manufactured in the same manner as in Example 1, except that the cleaning conditions for the glass substrate were changed as shown in Table 4. . The cleaning liquid “N” in Comparative Example 2 was used.
"CW-601A" represents a commercially available detergent-containing cleaning solution (manufactured by Wako Pure Chemical Industries, Ltd.).

[0057]

[Table 4]

[0058]

According to the present invention described above, the glass cullet adhered to the glass substrate is removed, and a color filter which does not cause a common short can be manufactured in high yield. Is big.

Claims (5)

[Claims] In a method of manufacturing a color filter for forming a black matrix and pixel images of red, green and blue on a glass substrate, a glass substrate from which a glass cullet of 5 μm or more has been removed is used as the glass substrate. A method for producing a color filter, comprising: 2. After applying a photopolymerizable composition in which a black material is dispersed on a glass substrate, heat drying, image exposure, development, and heat curing are performed to form a black matrix. Using a photopolymerizable composition in which green and blue materials are each dispersed, the above black matrix forming surface is coated, heated and dried, and subjected to image exposure and heat curing to obtain red, green and blue. 2. The method according to claim 1, wherein pixel images of each color are formed. 3. The production method according to claim 1, wherein a glass substrate which has been subjected to brush cleaning and ultrasonic cleaning in an alkaline cleaning liquid is used. 4. The production method according to claim 3, wherein the pH of the alkaline cleaning liquid is 13 or more. 5. The method according to claim 3, wherein an alkaline cleaning solution containing NaOH or KOH is used.