JPH04123006A - Production of color filter for liquid crystal display - Google Patents

Abstract

PURPOSE:To improve display quality and to reduce a cost by laminating a photosensitive resin and a silicone rubber layer on a light transparent substrate formed with a patterned black matrix and forming the partition walls between picture elements by using these layers. CONSTITUTION:The photosensitive resin layer having pattern formability by photolithography and the silicone rubber layer having a large oil- and water- repelling effect are laminated in this order on the glass substrate on which the patterned light shielding films to constitute the black matrix are previously formed. These layers are used and are subjected to exposing through the black matrix by a photolithography method, then to development processing. The partition walls to prevent the blotting and spreading of printing ink or the ink applied by an ink jet method, etc., are produced simultaneously with the formation of the black matrix. The partition walls between the picture elements acting effectively in a coloring process are produced and the low-cost color filters for liquid crystal display having high display quality are obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of manufacturing a color filter for liquid crystal display with high display quality and at low cost.

[Prior Art] A color filter for a liquid crystal display is composed of a large number of picture elements, each picture element being a pixel of the three primary colors of red, green, and blue formed on a transparent substrate. A light shielding area (generally black and called a black matrix) having a certain width is provided between each pixel in order to enhance display contrast.

Color filters can be manufactured using low-cost methods such as dyeing a dyeable medium formed using photolithography, using a pigment-dispersed photosensitive composition, and electrodeposition using patterned electrodes. As a manufacturing method, there is a method of forming a colored portion by a printing method or an inkjet method.

Among conventional manufacturing methods, printing methods and inkjet methods that can provide low-cost color filters are manufactured using photolithography in advance in order to prevent pixels from bleeding in each colored area and achieve high-precision coloring. An attempt to utilize a black matrix that can be used has been proposed. Therefore, it is desired that the material forming the black matrix has the effect of preventing the colorant from spreading outside the intended coloring area.

For example, Japanese Unexamined Patent Publication No. 59-75205 discloses a technique using an inkjet method to arrange three colors of dyes on a substrate. In order to prevent the dye from spreading outside the target area, it is said that forming a diffusion prevention pattern using a substance with poor wettability is effective, but no specific technique is disclosed. In addition, Japanese Patent Application Laid-Open No. 6 (1983) related to a color filter manufacturing method using a printing method.
2-. Publication No. 106407 also recommends an ink that does not easily wet the partition wall in order to prevent printing ink from bleeding and improve printing accuracy. However, it is difficult to select an ink material that easily wets the substrate and does not easily wet the partition walls.

[Problems to be Solved by the Invention] The present invention provides a high-quality, low-cost color for liquid crystal display, which is characterized by producing a partition wall that works effectively in a coloring process such as a printing method or an inkjet method. A method for manufacturing a filter is provided.

[Means for Solving the Problems] The present invention involves laminating a photosensitive resin layer and a silicone rubber layer in this order on a light-transmitting substrate on which a patterned black matrix is formed, and applying the layers by photolithography. By exposing to light through a black matrix and performing a development process, a desired pattern is created in which only the silicone rubber layer or both the silicone rubber layer and the photosensitive resin layer below it are removed, and the removed areas are colored red, This is a method for manufacturing a color filter for liquid crystal display, which is characterized by coloring in the three primary colors of green and blue.

In the present invention, a patterned light-shielding film that becomes the black matrix of a color filter is formed in advance on a glass substrate, and a photosensitive resin layer that has pattern formation ability by photolithography and a highly oil- and water-repellent layer are used. Using a material in which silicone rubber layers are laminated in this order, a black matrix is formed, and a highly accurate color filter is manufactured by preventing printing ink or ink applied by an inkjet method from bleeding or spreading.

The black matrix on the light-transmitting substrate formed in the present invention can be formed by chromium sputtering, resist coating, pattern exposure, development and baking, chromium etching,
Finally, it is formed by removing the resist. The pattern shape can be arbitrarily selected, such as a stripe shape or a lattice shape, as required.

The composition of the photosensitive resin layer used in the present invention is exposed to light through a light-blocking black matrix formed in advance on a light-transmitting substrate, and the photosensitive resin layer in the light-blocked area and the silicone rubber layer thereon are exposed. must remain on the substrate,
For this purpose, it is essential that the exposed area has the property of changing and becoming soluble in the developing solvent. As a photosensitive resin composition suitable for such requirements, there is a positive resist used for manufacturing LSI. As a positive resist, for example, a cresol novolak resin mixed with a naphthoquinone diazide compound can be used, and a commercially available resist can also be used as is. The purpose of the present invention is to manufacture a color filter by manufacturing a partition wall having ink repellency at a position corresponding to a black matrix formed in advance on a light-transmitting substrate, and by coloring the area surrounded by the partition wall. This is what I am trying to do. During exposure and development, only the silicone rubber layer in the exposed area, or both the silicone rubber layer and the photosensitive resin layer below it, may be removed, but it is not necessary to modify the resin layer for coloring purposes or to impart necessary characteristics. Addition of various components is performed. For example, if only the exposed silicone rubber layer is removed during the development process, it will be easier to receive printing ink or ink components given by the inkjet method, and dye ink will be sprayed using the inkjet method to dye the resin layer. can do. As a means to make only the silicone rubber layer removable in this way,
The method disclosed in No. 54222 can be used. In order to dye a resin layer by jetting a dye ink using an inkjet method, it is necessary to provide a component having a dyeing site to the resin by means such as reaction or mixing. As a dyeing medium, known natural polymeric materials such as collagen, casein, gelatin, etc. can be used as a base and modified according to the purpose of the present invention.

It is essential that the silicone rubber layer coated on the surface layer has the effect of repelling the ink components, and includes, but is not limited to, the following repeating units with a molecular weight of several thousand to several tens of blades. The main component is linear organic polysiloxane.

(where n is an integer of 2 or more, and R is an alkyl group, alkenyl group, or phenyl group having 1 to 10 carbon atoms) A silicone rubber can be obtained by sparsely crosslinking such a linear organic polysiloxane. Crosslinking agents include acetoxysilane, ketoximesilane, alkoxysilane, aminosilane, amidosilane, acetoxysilane, etc., which are used in so-called room temperature (low temperature) curing silicone rubber, and are usually linear organic polysiloxanes with hydroxyl groups at the ends. When combined with other substances, they become acetic acid-free silicone rubber, oxime-free silicone rubber, alcohol-free silicone rubber, deaminated silicone rubber, deamidated silicone rubber, and ketone-free silicone rubber.

Additionally, a small amount of an organic tin compound or the like is added to the silicone rubber as a catalyst.

In order to bond the photosensitive resin layer and the silicone rubber layer, various adhesive layers may be used between the layers, and aminosilane compounds and organic titanate compounds are particularly preferred. Instead of providing an adhesive layer between the photosensitive resin layer and the silicone rubber layer, an adhesive component may be added to the silicone rubber layer. Aminosilane compounds and organic titanate compounds can also be used as this additional adhesive component.

The light-transmitting substrate of the present invention is not particularly limited, and glass, plastic films, sheets, etc. are preferably used.

The composition of the present invention can be produced, for example, as follows.

First, a transparent thin film that will serve as an adhesive layer or an ink receptivity improving layer is formed as needed on a light-transmissive substrate on which a black matrix has been formed in advance, and then a dip method is applied.
A composition solution constituting the photosensitive resin layer is applied, dried, and cured if necessary using a coater such as a roller, a rotary coating device such as a wheller, or a spinner. If necessary, apply an adhesive layer on the photosensitive resin layer in the same manner as above.
After drying, a silicone rubber layer is applied in the same manner and heat-treated at a temperature of usually 100 to 130° C. for several minutes to form a silicone rubber layer. If necessary, a protective cover film may be covered over the silicone rubber layer using a laminator or the like.

The protective film is provided to prevent damage to the surface silicone rubber layer during storage, transportation, handling, and work processes, and is generally made of polypropylene or polyester film. The thickness of the film is preferably about 100 μm or less. By exposing a black matrix previously formed on a light-transmitting substrate as a light-shielding pattern and developing it, only the silicone rubber layer or the silicone rubber layer and the photosensitive resin layer are removed to form concave silicone rubber-free areas. form. The mutual ratio between the size of the area without silicone rubber and the area where silicone rubber is held on the surface layer varies depending on the purpose of use.

The present invention aims to provide a color filter for a liquid crystal display element. The size of each pixel of the color filter is approximately 100 μm, and the line width of the light-shielding partition provided in each pixel, that is, the black matrix, is approximately 20 μm. These pixels may be of a so-called stripe type arranged in a line, or colored parts surrounded by a black matrix may be arranged in a grid pattern. The purpose of producing a color filter is achieved by supplying a coloring agent such as ink or a dye component for dyeing the area to these subdivided areas to be colored by a printing method, an inkjet method, or the like.

The embodiments of the present invention will be explained below with reference to Examples, but the present invention is not limited thereto.

[Example] Example 1 A chromium sputtered film of approximately 150 OA was formed on a glass plate, and a width of 30 μm was formed by photolithography using a resist.
A linear black matrix with an m1 interval of 150 μm was produced. On the same side of the glass substrate as the black matrix film, a phenol novolac resin with a degree of esterification of 45% ("Sumiresin" PR5023, manufactured by Jusumin Bakelite Co., Ltd.) is applied.
A 10% dioxane solution of naphthoquinone-1,2-diazide-5-sulfonic acid ester (molecular weight 1300) of 5) was applied and dried in hot air at 60°C to form a 2 μm thick photosensitive resin layer. .

On top of this, γ-aminopropyltriethoxysilane (t
A 0.5% by weight fi-hexane solution of LCC (1100) was applied and dried in hot air at 100°C. Further, a 10% by weight n-hebutane solution of a silicone rubber composition having the following composition was applied thereon and dried in hot air at 100°C to form a silicone rubber layer with a thickness of 2 μm.

Silicone rubber layer composition a. Polydimethylsiloxane (molecular weight approximately 80,000, both terminals O
For protection, a 13 μm polypropylene film was laminated on the silicone rubber layer for protection.

This laminate was set in an Idolfin 2000 exposure machine so that light was applied from the glass substrate side, and UV light was irradiated from a distance of 1 m for 59 seconds. Peel off the protective film and
The surface of silicone rubber is “isopar” (manufactured by ESSO).
When rubbed lightly with a cotton pad containing a 35/65 (weight ratio) mixture of ethanol and ethanol, the exposed silicone rubber layer and the photosensitive resin layer underneath were removed. On top of the black matrix there is a partition wall whose surface layer is a silicone rubber layer with high ink repulsion properties.

50 parts by weight of cyclopentadiene resin with a softening point of 145°C (Yatsuki Kagaku "Yatsukoku Neoresin" 540), 5 parts by weight of alkyd resin, petroleum solvent (Nippon Oil No. 5 Solvent)
45 parts by weight were mixed under nitrogen flow and heated to 200°C.
Varnish A was obtained by heating and stirring for 1 hour. This varnish A
80 parts by weight and 20 parts by weight of phthalocyanine blue were kneaded using three rolls to obtain blue ink. In the case of green ink, Phthalocyanine Green was used, and in the case of red ink, Brilliant Carmine 6B was used.

The laminate obtained above was colored by sequentially printing the three primary colors of red, green, and blue using a lithographic offset printing method using these inks and "Toshimizuless lithography."

The ink had good printability, was sufficiently repelled by the partition wall, and good coloring without color bleeding was achieved.

Example 2 In Example 1, 4. was added to 100 parts by weight of the polymer component of the photosensitive resin layer in order to leave the photosensitive resin layer.
30 parts by weight of 4'-diphenylmethane diisocyaner) and 0.2 parts by weight of dibutyltin dilaurate were added, coated on a glass substrate on which a black matrix had been formed in advance, and heat-treated at 120°C for 2n+in. Example 1
A solution prepared by adding 3 parts by weight of γ-aminopropyltriethoxysilane as an adhesive component to the silicone rubber composition was applied thereon and cured in the same manner. Exposure and development were performed in the same manner as in Example 1 to obtain a processed product with the photosensitive resin layer in the exposed area remaining on the glass substrate and a partition wall with a silicone rubber layer on the surface layer on the black matrix. Obtained. The exposed portion of the resin layer was colored with the three primary colors of red, green, and blue using the same printing method as in Example 1 to produce a color filter. The partition wall of the silicone rubber layer worked effectively, and no ink bleeding occurred, making it possible to obtain a color filter without color mixing.

Example 3 In the same manner as in Example 2, a processed product was obtained in which the photosensitive resin layer in the exposed area remained on the glass substrate and had a partition wall with a silicone rubber layer on the surface layer on the black matrix. .

The exposed portion of the resin layer was colored by spraying an inkjet ink having the ink composition shown below. The partition wall of the silicone rubber layer worked effectively, and no ink bleeding occurred, making it possible to obtain a color filter without color mixing.

Ink formulation stomach.

Urethane modified acrylate oligomer 150 parts by weight dipentaerythritol hexacrylate
15 parts by weight Benzyl dimethyl ketal 10 parts by weight 2-thalolthioxanthone 3 parts by weight Sodium thiocyanate 4 parts by weight Methyl ethyl ketone 200 parts by weight Dye 10 parts by weight Red: Solvent Red 132 Blue: Solvent Blue-67 Green: Solvent Blue-67/Solvent Yellow 89 Example 4 A lattice-shaped black matrix having a width of 30 μm and vertical and horizontal intervals of 150 μm was prepared in advance using a chromium sputter film on a glass substrate.

In Example 2, methyl methacrylate/hydroxyethyl methacrylate/dimethylaminopropyl methacrylate (30
/30/40 molar ratio) terpolymer naphthoquinone-1
, 2-diazide-5-sulfonic acid ester was used, and exposure and development were carried out in the same manner. An ink containing an acid dye was applied by spraying using an inkjet method, and a dyeing treatment was performed to color the silicone rubber layer removed portion in the three primary colors of red, green, and blue to obtain a color filter.

Because it is a top coat, the silicone rubber layer in the black matrix area becomes an obstacle, so the entire surface was exposed to light before coating, and then the silicone rubber layer was removed by rubbing that area with a cotton pad containing a solvent such as n-heptane. .

[Effects of the Invention] The method of the present invention exhibits great effects when producing colored regions for color filters by methods such as printing and inkjet methods.

It is an essential requirement to construct a black matrix, which is a light-blocking partition between the pixels of a color filter. The creation of resilient partition walls is also a necessary condition. The present invention
This invention discloses a method for obtaining a color filter for liquid crystal display that can easily and effectively implement these important elements and also has high display quality.

Claims (2)

[Claims] (1) A photosensitive resin layer and a silicone rubber layer are laminated in this order on a light-transmissive substrate on which a patterned black matrix is formed, and then exposed to light through the black matrix using a photolithography method and developed. ,
It is characterized by creating areas in a desired pattern by removing only the silicone rubber layer or both the silicone rubber layer and the photosensitive resin layer below, and then coloring the removed areas in the three primary colors of red, green, and blue. A method for manufacturing color filters for liquid crystal displays. (2) The color filter for liquid crystal display according to claim (1), characterized in that after being colored in the three primary colors of red, green, and blue, the entire surface is irradiated with light to remove the silicone rubber layer on the surface of the light-shielding film portion. Manufacturing method.