JP2006337952A - Manufacturing method of color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of color filter capable of broadening the tolerance of alignment in a printing method and reducing defective prints such as level difference or clearance. <P>SOLUTION: In the manufacturing method of color filter having colored pixel patterns of respective colors of R(red), G(green), B(blue) and a black matrix on a substrate, the colored pixel patterns of the respective colors are formed on the substrate (process (1)) by applying a letterpress reverse offset printing method composed of a process (1a) of forming a coating layer by applying a colored resin composition on a coating layer forming substrate, a process (1b) of transferring a contact part of the coating layer to protrusion part surfaces of letterpress by pressing the letterpress having a prescribed pattern against the coating layer and removing the contact part and a process (1c) of transferring the coating layer remaining on a coating layer-forming substrate to the substrate after the process (1b), at every colors and, thereafter, the black matrix made of a black resin composition is self-alignedly formed on regions other than the colored pixel pattern on the substrate (process (2)). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a color filter, and more particularly, to a method for manufacturing a color filter having a plurality of colored pixel patterns and a black matrix on a substrate.

  In recent years, in the fields of liquid crystal display devices, sensors, color separation devices, and the like, color display has progressed and color filters have been frequently used. A dyeing method is conventionally known as a method for producing a color filter. In the dyeing method, a dyeable resin (for example, natural gelatin or casein) is applied on a substrate, and then patterned to form a desired pixel pattern, and the pixel pattern is dyed mainly using a dye. A colored pixel pattern is formed. However, color filters manufactured by such a dyeing method tend to be inferior in heat resistance and light resistance, because materials that can be used at the time of manufacture are restricted. Therefore, in recent years, a method using a photosensitive material in which a pigment is dispersed (pigment dispersion method) has attracted attention and various studies have been conducted. In the pigment dispersion method, a photosensitive material (resist) in which a pigment is dispersed on a substrate is applied, and then a colored pixel pattern is formed by performing exposure and development according to a photolithography method. The pigment dispersion method is more convenient than the dyeing method, and the manufactured color filter is preferable because it is excellent in heat resistance and light resistance and is stable and has a long life.

  However, there is a limit to manufacturing a large screen color filter by applying a pigment dispersion method accompanied by a photolithography method. For example, when a resist is applied to a large substrate of 1 m square or more, application by a spin coater becomes difficult, and thus a coating apparatus such as a slit coater is usually used. However, application by a slit coater tends to make it difficult to ensure the uniformity of the coating film. In particular, in the case of manufacturing a color filter having a light-shielding black matrix made of resin or thin film metal in addition to the colored pixel pattern, the colored pixel pattern is formed after the black matrix is formed. That is, since the resist is applied to the substrate surface with a step, it is difficult to ensure the uniformity of the colored pixel pattern coating film. Further, the photolithographic method requires expensive equipment such as an exposure machine and a developing device. In particular, when manufacturing a color filter having a large screen, a large exposure machine, a developing device, a baking furnace, and a large clean room in which these sections are installed are required, and the capital investment is huge. Therefore, it is desired to realize a large screen and high quality color filter by using an inexpensive method other than the photolithography method.

Printing methods and electrodeposition methods are known as methods other than the photolithographic method applicable to the production of color filters. Among these, the printing method is preferable in that it is inexpensive and can perform coating film formation and pixel pattern formation at the same time. However, since it is difficult to realize a color filter having a smooth and high-definition pattern size and shape by a printing method, various improvements have been studied. For example, Patent Documents 1 and 2 disclose that a high-definition and smooth image can be obtained by applying an offset printing method.
JP-A-11-58921 JP 2000-289320 A

  According to the offset printing method described in Patent Documents 1 and 2, three-color printing of colored pixel patterns of R (red), G (green), and B (blue), or these colored pixel patterns and a light shielding film (black matrix) By performing the four-color simultaneous printing, it is possible to expect a cost reduction effect in manufacturing the color filter. In order to manufacture a color filter by simultaneous printing, prior to printing on a substrate, it is necessary to accurately align the colored pixel patterns on the plate surface and further align the patterns and the black matrix. However, it is difficult to accurately perform alignment on the printing plate. In particular, advanced techniques are required for accurate alignment between the colored pixel pattern and the black matrix. If alignment is not appropriate, a step due to overcoating or a gap that causes light leakage occurs in the color filter, and it is difficult to manufacture a high-quality color filter. Therefore, a simpler method capable of realizing a large screen and high quality color filter at low cost is desired.

  Therefore, in view of the above-described situation, an object of the present invention is to provide a method for manufacturing a color filter capable of widening the margin of alignment in a printing method and reducing printing defects such as steps or gaps. .

  As a result of intensive studies to solve the above problems, the present inventors have formed a colored pixel pattern using a printing method, and then formed a black matrix in a self-aligned manner, thereby forming a colored pixel pattern and a black pixel pattern. It has been found that a high-quality color filter in which strict alignment with the matrix is not necessary and printing defects such as steps and gaps are reduced can be obtained, and the present invention has been completed. The present invention is as follows.

  The method for manufacturing a color filter according to the present invention is directed to manufacturing a color filter having a colored pixel pattern of each color of R (red), G (green), and B (blue) and a black matrix on a substrate. (I) (ia) a step of applying a colored resin composition on a substrate for forming a coating layer to form a coating layer; and (ib) pressing a relief plate having a predetermined pattern on the coating layer, A step of transferring and removing the contact portion of the coating layer on the convex surface of the relief printing; and (ic) a step of transferring the coating layer remaining on the coating layer forming substrate after the step (ib) to the substrate. A step of forming a colored pixel pattern of each color on the substrate by applying a relief reversal offset printing method for each color, and (ii) a black resin composition in a region other than the colored pixel pattern on the substrate Blackma made of things The Rikusu characterized by a step formed in a self-aligned manner.

  Here, the black matrix is preferably formed by applying a black resin composition to an area other than the colored pixel pattern on the substrate by using an inkjet printing method using the colored pixel pattern as a bank material. Alternatively, the black matrix may be formed by (iia) applying a photosensitive black resin composition to the surface of the substrate on which the colored pixel pattern is formed, and (iib) irradiating active light from the back surface of the substrate. The photosensitive black resin composition is preferably cured and (iic) is formed by removing the uncured photosensitive black resin composition on the colored pixel pattern by development.

  According to the method for manufacturing a color filter of the present invention, since the tolerance of alignment at the time of printing is widened, it is possible to provide a high-quality color filter with less defects such as steps and gaps with a high yield.

  Details of the present invention will be described below. The present invention is directed to a method of manufacturing a color filter having a colored pixel pattern of each color of R (red), G (green), and B (blue) and a black matrix on a substrate. A step of forming a colored pixel pattern of each color on the substrate by applying an offset printing method for each color; and (ii) a black matrix comprising a black resin composition in a region other than the colored pixel pattern on the substrate. In a self-aligned manner.

  An example of the relief printing offset printing method applied in the step (i) will be described with reference to FIG. The letterpress reverse offset printing method typically includes (ia) a step of applying the colored resin composition 20 on the coating layer forming substrate 10 to form the coating layer 20a, and (ib) the coating layer 20a. Pressing the relief plate 30 having a predetermined pattern to transfer and remove the contact portion 20b of the coating layer on the surface of the projection 30a of the relief plate 30, and (ic) forming the coating layer after the step (ib). And the step of transferring the coating layer 20c remaining on the base material 10 to the color filter substrate 40. Through such a process, first, a colored pixel pattern 20c ′ of the first color (R) as shown in FIG. 2A is formed on the substrate 40. In the present invention, the transfer position in the step (ic) is shifted for each color, and the relief reversal offset printing is repeated for each color. After forming the colored pixel pattern of the first color (for example, R), the above steps (ia) to (ic) are continuously repeated to transfer the colored pixel pattern of the second color and the third color (for example, G, B). As a result, a colored pixel pattern of three colors (RGB) as shown in FIG. 2B is finally obtained.

  The coating layer-forming substrate 10 that can be used in the above step (ia) is not particularly limited, but in consideration of the release property of the coating layer in the removal or transfer step, for example, a silicone rubber It is preferable to have a silicone resin surface such as a PET film having a release property imparting treatment. The shape of the base material is not particularly limited, and may be a roll shape or a stamp shape. In FIG. 1, the case where the offset blanket was provided in the main trunk | drum surface was shown as a typical example of a coating layer formation base material.

  In the said process (ia), application | coating of the colored resin composition on a coating layer forming base material is not specifically limited, It is possible to apply a well-known technique. For example, liquid colored resin composition by techniques such as capillary coater application, die coater application, roll coater application, spin coater application, spray application, dip coater application, curtain flow coater application, wire bar coater application, gravure coater application, air knife coater application, etc. There is a method of directly applying an object on a substrate. As another method, there is a method in which a liquid colored resin composition is once applied to a temporary support and then transferred onto a coating layer-forming substrate. As the temporary support, it is possible to use a PET film that has releasability or has been subjected to a releasability imparting treatment, or a member similar to the above-mentioned coating layer forming substrate.

  The colored resin composition that can be used in the present invention is not particularly limited, but can be prepared, for example, by dispersing an organic or inorganic pigment usually used in a pigment dispersion method in a resin. . From the viewpoint of color expression, it is preferable to use an organic pigment. Examples of organic pigments include azo, phthalocyanine, indigo, anthraquinone, perylene, quinacridone, methine / azomethine, and isoindolinone compounds. In order to obtain each color pixel pattern of RGB constituting the color filter, a pigment capable of imparting appropriate red, green, and blue colors to the colored resin composition is selected and used. .

  The red colored resin composition can be toned using a single red pigment system or a mixture of a red pigment system and a yellow pigment system. Examples of the red pigment system include a color index name, C.I. I. Pigment red 9, 123, 155, 168, 177, 180, 217, 220, 224, 254. Examples of the yellow pigment system include a color index name, C.I. I. Pigment yellow 17, 20, 24, 83, 93, 109, 110, 117, 125, 128, 129, 138, 139, 147, 150, 154, 180, 185. Two or more of these red pigment systems and yellow pigment systems can be used in combination. When using a mixture of a red pigment system and a yellow pigment system, the yellow pigment system is preferably used in an amount of 60 parts by weight or less with respect to 100 parts by weight of the total amount of the red pigment system and the yellow pigment system. .

  The green colored resin composition can be toned using a single green pigment system or a mixture of the green pigment system and the yellow pigment system. Examples of the green pigment system include color index names such as C.I. I. Pigment green 7, 36, 37. Two or more of these green pigment systems and yellow pigment systems can be mixed and used. In the case of using a mixture of a green pigment system and a yellow pigment system, the yellow pigment system is preferably used in an amount of 50 parts by weight or less with respect to 100 parts by weight of the total amount of the green pigment system and the yellow pigment system.

  The blue colored resin composition can be toned using a single blue pigment system or a mixture of a blue pigment system and a purple pigment system. Examples of the blue pigment system include a color index name, C.I. I. Pigment Blue 15, 15: 3, 15: 4, 15: 6, 22, and 60. Examples of purple pigments include the color index name, C.I. I. Pigment violet 19, 23, 29, 37, 50. Two or more of these blue pigment systems and purple pigment systems can be used in combination. In the case of using a mixture of a blue pigment system and a violet pigment system, the violet pigment system is preferably used in an amount of 50 parts by weight or less with respect to 100 parts by weight of the total amount of the blue pigment system and the violet pigment system.

  The resin that can be used for the colored resin composition is preferably one that has excellent pigment dispersibility, and further has film formability and visible light transparency. Examples of preferable resins that can be used in the present invention include acrylic resins, epoxy resins, melamine resins, polyester resins, urethane resins, and alkyd resins. Thermosetting resins such as epoxy resins, melamine resins, and urethane resins can be used alone, but other resins may be used in combination. Moreover, when using thermoplastic resins, such as an acrylic resin and a polyester resin, it is preferable to make a colored resin composition thermosetting by using together a polyfunctional acrylic monomer or the said thermosetting resin.

  Although not particularly limited, an acrylic resin is particularly preferable from the viewpoints of film formability and pigment dispersibility with respect to the coating layer forming substrate. As acrylic resin, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, glycidyl methacrylate, bis-glycidyl methacrylate, dimethylaminoethyl methacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, lauryl methacrylate, stearyl methacrylate, benzyl methacrylate, benzyl (Meth) acrylates such as acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl methacrylate, hexyl acrylate, octyl methacrylate, octyl acrylate, and phosphorus-containing methacrylate Homopolymers or copolymers of uric acid (meaning acrylic acid and methacrylic acid) esters, or copolymers of these (meth) acrylic acid esters with styrene, styrene derivatives, or other polymerizable monomers; ) A carboxyl group-containing polymerizable monomer such as acrylic acid, itaconic acid, maleic acid, maleic anhydride, maleic acid monoalkyl ester, citraconic acid, citraconic anhydride, citraconic acid monoalkyl ester, and (meth) acrylic acid ester, styrene, Styrene derivatives or copolymers with other polymerizable monomers can be used.

  As said maleic acid monoalkyl ester, that whose alkyl carbon number is 1-12 is preferable. Specifically, monomethyl maleate, monoethyl maleate, mono-n-propyl maleate, monoisopropyl maleate, mono-n-butyl maleate, mono-n-hexyl maleate, mono-n-octyl maleate, Examples thereof include mono-2-ethylhexyl maleate, mono-n-nonyl maleate, mono-n-dodecyl maleate and the like.

  As the citraconic acid monoalkyl ester, alkyl having 1 to 12 carbon atoms is preferable. Specifically, citraconic acid monomethyl, citraconic acid monoethyl, citraconic acid mono-n-propyl, citraconic acid monoisopropyl, citraconic acid mono-n-butyl, citraconic acid mono-n-hexyl, citraconic acid mono-n-octyl, Examples include citraconic acid mono-2-ethylhexyl, citraconic acid mono-n-nonyl, citraconic acid mono-n-dodecyl, and the like.

  Examples of the styrene derivative include α-methylstyrene, m- or p-methoxystyrene, p-hydroxystyrene, 2-methoxy-4-hydroxystyrene, and 2-hydroxy-4-methylstyrene.

Other polymerizable monomers include, for example, N-cyclohexylmaleimide, N-2-methylhexylmaleimide, N-2-ethylcyclohexylmaleimide, N-2-chlorocyclohexylmaleimide, N-phenylmaleimide, N-2-methylphenyl Maleimide, N-2-ethylphenylmaleimide, N-2-chlorophenylmaleimide, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, tricyclo [5.2.1.0 ^2,6 ] decanyl group (Meth) acrylic acid ester having

  When the colored resin composition is constituted using an acrylic resin, the weight average molecular weight of the acrylic resin is preferably in the range of 1,500 to 200,000, and more preferably in the range of 5,000 to 100,000. It is preferable that it is in the range of 10,000-50,000 especially. When the weight average molecular weight of the acrylic resin is 1,500 or less, the pigment dispersibility tends to decrease. On the other hand, when the weight average molecular weight is 200,000 or more, the solubility in the solvent tends to be lowered when the colored resin composition is applied and dissolved in a solvent to form a liquid. The term “weight average molecular weight” described in the present specification is a value measured by gel permeation chromatography and converted using a standard polystyrene calibration curve.

  The acrylic resin having a weight average molecular weight of 1,500 to 200,000 is a (meth) acrylic resin, specifically, (I) 2-hydroxyethyl methacrylate and (II) methacrylic acid or methyl methacrylate. Resin consisting of at least two monomer components, or (III) resin consisting of three monomers including (meth) acrylic monomer having one or more benzene rings in the unit molecule and copolymerizable, It is preferable from the viewpoint of dispersion stability.

  In addition, when a thermoplastic acrylic resin or polyester resin is used as the resin constituting the colored resin composition, it contains a polyfunctional monomer having two or more photopolymerizable unsaturated bonds in the molecule, A thermosetting resin composition can be obtained by using a thermosetting epoxy resin, urethane resin, melamine resin, or the like together. Furthermore, it is possible to make an ink composition by containing an organic solvent. In addition to the acrylic resin, when another resin or a monomer having two or more photopolymerizable unsaturated bonds in the molecule is used in combination, the resin or monomer is 200 weights with respect to 100 weight parts of the total amount of the acrylic resin. It is preferable to use in less than parts.

  Examples of monomers having two or more photopolymerizable unsaturated bonds in the molecule include, for example, ethylene oxide (EO) modified bisphenol A diacrylate, epichlorohydrin (ECH) modified bisphenol A diacrylate, bisphenol A dimethacrylate, 1,4-butanediol diacrylate, 1,3-butylene glycol diacrylate, diethylene glycol dimethacrylate, glycerol dimethacrylate, neopentyl glycol diacrylate, EO-modified phosphoric acid diacrylate, ECH-modified phthalic acid diacrylate, polyethylene glycol 400 Acrylate, polypropylene glycol 400 dimethacrylate, tetraethylene glycol diacrylate, ECH modified 1,6-hexanediol diacrylate, tri Tyrolpropane triacrylate, pentaerythritol triacrylate, EO-modified phosphoric acid triacrylate, EO-modified trimethylolpropane triacrylate, propylene oxide (PO) -modified trimethylolpropane triacrylate, tris (methacryloxyethyl) isocyanurate, pentaerythritol tetraacrylate Acrylates such as dipentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, and methacrylates corresponding to these. These monomers can be used alone or in combination of two or more.

  Moreover, you may use resin which has a light or a thermopolymerizable unsaturated bond as resin which comprises a colored resin composition. Preferable examples of such resins include high acid value carboxy group-containing acrylic resins, glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether, α-ethyl glycidyl acrylate, crotonyl glycidyl ether, itaconic acid monoalkyl glycidyl ether, etc. Or an allyl alcohol, 2-buten-4-ol, furfuryl alcohol, oleyl alcohol, cinnamyl alcohol, 2-hydroxyethyl acrylate, 2-hydroxyethyl Resin obtained by reacting a compound (unsaturated alcohol) having one hydroxyl group and an ethylenically unsaturated bond such as methacrylate or N-methylolacrylamide, a carboxyl group-containing tree having a hydroxyl group A resin obtained by reacting an unsaturated compound containing a free isocyanate group with a resin, a resin obtained by reacting an addition reaction product of an epoxy resin and an unsaturated carboxylic acid with a polybasic acid anhydride, a conjugated diene polymer or a conjugated diene copolymer. Examples include resins obtained by reacting a hydroxyl group-containing polymerizable monomer with an addition reaction product with a saturated dicarboxylic acid anhydride.

  The colored resin composition used in the present invention is prepared by dispersing a pigment in a resin. More specifically, a resin, an organic solvent, and a dispersant as necessary are mixed, and then a pigment is added and dispersed. The prepared composition is preferably further subjected to a dispersion treatment by kneading using a dispersion kneader such as an ultrasonic disperser, a triple roll, a ball mill, a sand mill, a bead mill, a homogenizer, or a kneader. When dispersing the pigment, it is possible to finely disperse the pigment relatively easily by using a high-boiling alkylene glycol ether as a solvent. When a hydrocarbon solvent is used, it is difficult to finely disperse the pigment.

  The ratio of the pigment to the resin in the colored resin composition is preferably at least 20 parts by weight of the resin with respect to 100 parts by weight of the pigment. When the ratio of the resin is too small, the dispersion stability of the pigment tends to decrease. The organic solvent is preferably used at least 100 parts by weight at the time of dispersion with respect to 100 parts by weight of the total amount of the pigment and resin at the time of dispersion. If the amount is less than 100 parts by weight, the viscosity at the time of dispersion is too high, and dispersion may be difficult particularly when dispersed by a ball mill, sand mill, bead mill or the like.

  The use of a dispersant is optional. However, it is preferable to use a dispersant from the viewpoint of dispersibility and dispersion stability of the pigment. Examples of the dispersant include anionic dispersants such as polycarboxylic acid type polymer surfactants and polysulfonic acid type polymer surfactants, nonionic dispersants such as polyoxyethylene / polyoxypropylene block polymers, anthraquinone type And organic dye derivatives in which a substituent such as a carboxyl group, a sulfonate group, a carboxylic acid amide group, or a hydroxyl group is introduced into an organic dye such as perylene, phthalocyanine, or quinacridone. These pigment dispersants and organic pigment derivatives are preferably used in an amount of 50 parts by weight or less based on 100 parts by weight of the pigment. When used in an amount exceeding 50 parts by weight, the chromaticity of the colored resin composition tends to change.

  In addition to the above components, various additives can be added to the colored resin composition as necessary. For example, when the colored resin composition is cured with ultraviolet rays, a photoinitiator may be added to the composition. Examples of the photoinitiator include benzophenone, N, N′-tetraethyl-4,4′-diaminobenzophenone, 4-methoxy-4′-dimethylaminobenzophenone, benzyl, 2,2-diethoxyacetophenone, benzoin, and benzoin methyl. Ether, benzoin isobutyl ether, benzyldimethyl ketal, α-hydroxyisobutylphenone, thioxanthone, 2-chlorothioxanthone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methiphenyl) -2-morpholino-1-propane , T-butylanthraquinone, 1-chloroanthraquinone thio), 2,3-dichloroanthraquinone, 3-chloro-2-methylanthraquinone, 2-ethylanthraquinone, 1,4-naphthoquinone, 9,10- Enantorakinon, 1,2-anthraquinone, 1,4-dimethyl anthraquinone, 2-phenyl anthraquinone, 2- (o-chlorophenyl) -4,5-diphenyl imidazole dimer and the like. These photoinitiators can be used alone or in combination of two or more.

  Moreover, in order to improve the adhesiveness of a board | substrate and a coating film, you may add a titanate coupling agent, a silane coupling agent, etc. Further, a surfactant (fluorine-based, silicone-based, hydrocarbon-based compound) may be added to improve the smoothness of the film. In addition, various additives such as ultraviolet absorbers and antioxidants can be used as necessary. At the time of application, the colored resin composition is adjusted to an appropriate viscosity using a solvent such as a hydrocarbon solvent, an ester solvent, an alcohol solvent, or a ketone solvent.

  The substrate that can be used in the step (ic) of the present invention is not particularly limited, and can be selected depending on the application. For example, transparent glass plates such as white plate glass, blue plate glass, silica coated blue plate glass, and sheets or films made of synthetic resin such as polyester resin, polycarbonate resin, acrylic resin, vinyl chloride resin, and aluminum plate, copper plate, nickel plate, stainless steel Examples thereof include a metal plate such as a plate, other ceramic plates, and a semiconductor substrate having a photoelectric conversion element. A colored pixel pattern is transferred onto these substrates. The thickness of the colored resin film constituting the colored pixel pattern can be appropriately changed depending on the application, but is preferably in the range of 0.1 to 10 μm, and more preferably in the range of 0.2 to 5 μm. preferable. The colored pixel pattern of each color formed by the relief inversion offset method including the steps (ia) to (ic) has good pattern sharpness (that is, high definition) and excellent flatness.

  In the method for producing a color filter according to the present invention, after forming a colored pixel pattern according to the above steps (ia) to (ic), a black matrix is formed as step (ii). Therefore, the pattern shape of the black matrix is clearly defined by the high-definition colored pixel pattern, and the black matrix can be formed in a self-aligning manner.

  As a method of forming a black matrix in a self-aligning manner, a method of applying a black resin composition to a region other than a colored pixel pattern on a substrate by using an ink-jet printing method using a previously formed colored pixel pattern as a bank material Can be mentioned. As another method, (iia) a photosensitive black resin composition is applied to the surface of a substrate on which a colored pixel pattern is formed, and (iib) the photosensitive black resin is irradiated with actinic rays from the back surface of the substrate. Examples of the method include curing the composition and (iic) removing the uncured photosensitive black resin composition on the colored pixel pattern by development. An example of the color filter obtained by the manufacturing method according to the present invention is shown in FIG. In the figure, 20c 'indicates RGB colored pixel patterns, and a black matrix 50 is formed in a region other than these patterns on the substrate. In the present invention, since the black matrix is formed in a self-aligning manner, it is possible to efficiently provide a high-quality color filter that is smooth and has no gaps without aligning the colored pixel pattern and the black matrix. .

  When forming a black matrix by the inkjet printing method, for example, a black resin composition composed of black pigments of carbon black, graphite, titanium carbon, black iron, and manganese dioxide and various resins described above is used. Further, the black resin composition used for forming the black matrix contains an inorganic filler composed of titanium oxide, zinc oxide, alumina, or silicon oxide and carbon as necessary for the purpose of coloring or improving the inkjet printability. But you can. Their content may be about 0.01 to 50 parts by weight with respect to 100 parts by weight of the total amount of the composition, and they are used alone or in combination of two or more.

The viscosity of the black resin composition is not particularly limited, in order to obtain the inkjet printability, at 22 ° C., it is preferably ^{1 × 10 -3 ~100 × 10 -3} Pa · sec, 2 × 10 - It is more preferably ^{3 to} 90 × 10 ⁻³ Pa · sec, and particularly preferably 3 × 10 ⁻³ to 80 × 10 ⁻³ Pa · sec.

  Ink jet devices are roughly classified into a piezo conversion method and a heat conversion method depending on the difference in the ink ejection method. In the present invention, it is preferable to apply a piezo conversion method device. The particle forming frequency of the colored resin composition used as the ink is preferably about 5 to 100 KHz. The nozzle diameter is preferably about 1 to 80 μm, and an apparatus in which 1 to 1,000 nozzles are incorporated in one head is suitable.

  On the other hand, when forming a black matrix by the method by the said process (iia)-(iic), the black resin composition which added the photocurable resin or the photoinitiator and provided photosensitivity is used. The photocurable resin and the photoinitiator are as described above. In the step (iia), it is possible to apply the photosensitive black resin composition to the surface of the substrate using a known method.

  In the step (iib), the colored pixel pattern can be used as a light shielding mask by irradiating actinic rays from the back surface of the substrate. As a result, only the photosensitive black resin composition in the region other than the colored pixel pattern can be cured. In order to obtain a sufficient light shielding effect by the colored pixel pattern, it is preferable to adjust the active light transmittance of these patterns to be less than 20%. When the actinic ray transmittance is 20% or more, the light shielding effect is insufficient, and the photosensitive black resin composition on the colored pixel pattern is also cured, making it difficult to efficiently form a black matrix.

  As actinic rays, infrared rays, visible rays, ultraviolet rays, electromagnetic waves having a longer wavelength than infrared rays, electromagnetic waves having a shorter wavelength than ultraviolet rays, laser light, and the like can be used. Especially, it is preferable to use an ultraviolet-ray from the viewpoint of the reactivity of the photosensitive black resin composition to be used and the prevalence of an apparatus. Examples of the ultraviolet irradiation device include a carbon arc lamp, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, a metal halide lamp, a fluorescent lamp, and a tungsten lamp. The irradiation amount and the irradiation time are not particularly limited, and are appropriately adjusted according to the sensitivity of the photosensitive black resin composition to be used.

  In the step (iic), unnecessary portions can be removed by development. More specifically, it is possible to remove the uncured photosensitive black resin composition on the colored pixel pattern. The development can be carried out by using a known developer such as an aqueous developer such as an alkaline aqueous solution or an organic solvent, and according to a known method such as spraying, rocking immersion, brushing, and scraping. The developer is not particularly limited, but an alkaline aqueous solution is preferable from the viewpoint of environment and safety.

  Examples of the base used in the alkaline aqueous solution include alkali hydroxide (such as lithium, sodium or potassium hydroxide), alkali carbonate (such as lithium, sodium or potassium carbonate or bicarbonate), alkali metal phosphate (phosphoric acid). Potassium, sodium phosphate, etc.), alkali metal pyrophosphates (sodium pyrophosphate, potassium pyrophosphate, etc.), tetramethylammonium hydroxide, triethanolamine and the like. Among these, a preferable base is tetramethylammonium hydroxide.

  The development temperature and time can be appropriately adjusted according to the developability of the photosensitive black resin composition. Further, a surfactant, an antifoaming agent, a small amount of an organic solvent for promoting development, and the like may be mixed in the alkaline aqueous solution.

  In order to remove the base of the alkaline aqueous solution remaining in the photosensitive black resin composition after photocuring after carrying out the above development, if necessary, using an organic acid, an inorganic acid or an aqueous solution of these acids, The acid treatment (neutralization treatment) may be performed according to a known method such as spraying, rocking dipping, brushing, scraping or the like. Furthermore, you may provide the process of washing with water after such an acid treatment (neutralization treatment).

  The method for manufacturing a color filter according to the present invention has been described above. In the present invention, in addition to forming a colored pixel pattern and a black matrix according to the above-described steps, a well-known technique may be applied as appropriate in color filter manufacturing. Is possible. For example, after forming a colored pixel pattern and a black matrix on a substrate, a step of forming a protective layer on the surface thereof may be added. In order to enhance the heat resistance and chemical resistance of the color filter required in such a post-process, it is preferable to provide a heating step in addition to steps (i) and (ii) of the production method according to the present invention. The heating conditions are not particularly limited, but are determined in consideration of the heat resistance of the substrate and the heat resistance of various colored resin compositions in addition to the post-process. For example, the heating step can be performed using a hot plate or an oven as a heating means, for example, under a heating condition of a temperature of 150 ° C. to 250 ° C. and a time of 3 minutes to 120 minutes. Such a heating process may be performed after a series of processes, or may be performed every time the colored pixel pattern and the black matrix are formed.

  The color filter obtained by the manufacturing method according to the present invention can be applied to various uses that require color display, including liquid crystal display devices. FIG. 4 shows an example of a liquid crystal display device to which the color filter according to the present invention is applied. The liquid crystal display device includes a glass substrate 70, a reflective base layer 71, a reflective film 72, a planarizing film 73, transparent electrodes 74a and 74b, alignment films 75a and 75b, a liquid crystal layer 76, a spacer 77, And a planarizing film 78. A color filter 60 having a colored pixel pattern 20 c ′ and a black matrix 50 is provided on the substrate 40. Furthermore, a retardation film 80 and a polarizing plate 90 are provided on the surface of the color filter as necessary. In the figure, reference numeral 100 is a sealing material. Since the color filter according to the present invention is high quality without step defects and gaps, the display device to which the color filter of the present invention as represented by FIG. 4 is applied does not leak light and realizes excellent contrast display. It becomes possible.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, the scope of the present invention is not restrict | limited by a following example.

Example 1
Using a cap coater, a colored resin composition of R (red) is applied on a blanket having a silicone resin surface (see FIG. 1) and dried for 1 minute to form a coating layer having a thickness of 1.0 μm. did. Next, a glass relief plate was pressed against the coating layer, the contact portion of the coating layer was transferred to the convex portion of the relief plate, and the coating layer of an unnecessary portion (non-contact portion) was removed. Subsequently, the relief printing plate with a part of the coating layer transferred was brought into contact with the glass substrate, and the coating layer was transferred onto the glass surface. In this way, an R colored pixel pattern of 40 μm × 160 μm (rectangular) was formed on the glass substrate. According to the same procedure, using G (green) and B (blue) colored resin compositions, the G and B colored pixel patterns are placed on the same glass substrate, and the R colored pixel pattern is spaced by 20 μm. It formed so that it might adjoin. The size of G and B color pixels is 40 μm × 160 μm. As described above, a color filter precursor in which colored pixel patterns of each color of 40 μm × 160 μm were arranged in the order of RGB at a cycle of 180 μm on the glass substrate was produced.

  Next, a black matrix was printed using the previously formed RGB color pixel pattern of the color filter precursor as a bank material. Specifically, the black resin composition was applied to a region other than the colored pixel pattern using a piezo conversion type inkjet printer, and the resin was further cured using an ultrahigh pressure mercury lamp exposure machine. The color filter thus produced was placed in an oven and heat-treated at 200 ° C. for 30 minutes to complete the color filter.

  When the surface smoothness of the obtained color filter was evaluated by a stylus type step gauge, the maximum step under the condition of a scanning distance of 0.3 mm was 0.28 μm. Moreover, as a result of observing the pattern surface of the color filter with an optical microscope, it was confirmed that a black matrix was formed around the RGB colored pixel pattern without any gap, and that the color filter was a good color filter.

(Example 2)
In the same manner as in Example 1, a color filter precursor in which colored pixel patterns of each color of 40 μm × 160 μm were arranged in the order of RGB in a cycle of 180 μm on a glass substrate was produced. The color filter precursor was placed in an oven and heated at 200 ° C. for 30 minutes.

  Next, a black matrix was printed in a region other than the RGB colored pixel pattern of the color filter precursor formed earlier. Specifically, the photosensitive black resin composition was applied to the surface of the color filter precursor that had been previously heat-treated using a spin coater under conditions of 500 rpm and 10 seconds. Next, ultraviolet rays were irradiated from the back surface of the substrate on which the RGB colored pixel pattern was not formed using an ultrahigh pressure mercury lamp parallel exposure machine under the condition of 150 mJ, and the photosensitive black resin composition surrounding the colored pixel pattern was photocured. . The color filter precursor thus provided with the photosensitive black resin composition is developed by immersing it in a 2.38% tetramethylammonium hydroxide solution for 45 seconds to develop an uncolored pixel pattern. The cured photosensitive black resin composition was removed to form a black matrix. The color filter thus produced was placed in an oven and heat-treated at 200 ° C. for 30 minutes to complete the color filter.

  When the surface smoothness of the obtained color filter was evaluated by a stylus type step gauge, the maximum step under the condition of a scanning distance of 0.3 mm was 0.6 μm. Moreover, as a result of observing the pattern surface of the color filter with an optical microscope, it was confirmed that a black matrix was formed around the RGB colored pixel pattern without any gap, and that the color filter was a good color filter.

It is a conceptual diagram explaining an example of the letterpress reverse offset printing method applied at the process (i) of the manufacturing method by this invention. It is a front view which shows an example of the colored pixel pattern obtained by the process (i) of the manufacturing method by this invention, (a) shows the pattern of the 1st color, (b) shows the pattern which added 2 or 3 colors. It is a front view which shows an example of the color filter obtained with the manufacturing method by this invention. It is typical sectional drawing which shows an example of the liquid crystal display device to which the color filter by this invention is applied.

Explanation of symbols

10 ... Base material for forming the coating layer (Blanket)
DESCRIPTION OF SYMBOLS 20 ... Colored resin composition, 20a, 20b, 20c ... Application layer, 20c '... Colored pixel pattern 30 ... Letterpress, 30a ... Projection of letterpress 40 ... Substrate 50 ... Black matrix 60 ... Color filter 70 ... Glass substrate, 71 ... Reflective underlayer, 72 ... reflective film, 73 ... flattened film,
74a, 74b ... transparent electrode, 75a, 75b ... alignment film, 76 ... liquid crystal layer, 77 ... spacer, 78 ... flattening film,
80 ... retardation film 90 ... polarizing plate 100 ... sealing material

Claims (3)

A method of manufacturing a color filter having a colored pixel pattern of each color of R (red), G (green), and B (blue) and a black matrix on a substrate,
(I) (ia) a step of forming a coating layer by applying a colored resin composition on a substrate for forming a coating layer; and (ib) pressing the relief plate having a predetermined pattern on the coating layer to form the relief plate. A step of transferring and removing the contact portion of the coating layer on the surface of the convex portion, and (ic) a step of transferring the coating layer remaining on the substrate for forming the coating layer to the substrate after the step (ib). A step of forming a colored pixel pattern of each color on a substrate by applying a relief reversal offset printing method for each color, and (ii) a black resin composition in a region other than the colored pixel pattern on the substrate And a step of forming a black matrix made of the material in a self-aligning manner.   2. The black matrix is formed by applying a black resin composition to an area other than the colored pixel pattern on the substrate by using an inkjet printing method using the colored pixel pattern as a bank material. The manufacturing method as described in.   (Iia) A photosensitive black resin composition is applied to the surface of the substrate on which the colored pixel pattern is formed, and (iib) the photosensitive black resin is irradiated with actinic rays from the back surface of the substrate. The manufacturing method according to claim 1, wherein the composition is cured and (iic) is formed by removing the uncured photosensitive black resin composition on the colored pixel pattern by development.

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