JP2012168436A - Photosensitive white composition for color filter, and color filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive white composition for color filter which can maintain excellent pattern adhesion without causing residues, and an applied film and a color filter formed using the photosensitive white composition for color filter.SOLUTION: A photosensitive white composition for color filter contains at least (A) transparent resin, (B) photopolymerizable monomer, (C) photoinitiator, (D) interfacial active agent, and (E) solvent, in which a contact angle of water to an applied film obtained by applying the photosensitive white composition for color filter onto a substrate for drying, is 65° or more and 85° or less.

Description

  The present invention relates to a white composition for a photosensitive color filter, a plurality of white pixels and a plurality of white pixels used for color filters such as liquid crystal displays, plasma displays, electroluminescence panels, color video cameras, and image sensors. The present invention relates to a color filter having colored pixels.

  In recent years, liquid crystal display devices have been used in TV monitor applications, personal computer monitor applications, mobile applications, etc., and the level of demand for various characteristics such as higher brightness, higher color purity, lower power consumption, and higher contrast has increased. ing. Above all, high color reproduction and high brightness are characteristics that depend on the backlight light source and color filter used in the liquid crystal display device, and it is difficult to achieve both high color reproducibility and high luminance in conventional liquid crystal display devices. Met. That is, for high color reproducibility, it is necessary to increase the saturation of the color filter, but there is a problem that the luminance decreases with the increase in saturation.

  In a color liquid crystal display device, light is transmitted through two polarizing plates, and the light from the backlight is usually less than 1/3 due to loss in the colored pixel layer and the optical unit for color display. Not used. In addition, since light from the backlight having uniform luminance is used on the entire display screen, there is no difference between the luminance when the entire display screen is white and the peak luminance when locally displaying white. On the other hand, in a self-luminous display such as a cathode ray tube, the luminance can be increased by reducing the display area of white, which is excellent in expressing local white display.

  In order to maintain the brightness of the color filter and achieve high color reproduction, it is effective to provide fourth, fifth, and sixth filter segments in addition to the conventional red, green, and blue filter segments. In addition to the conventional red, green and blue filter segments, a white pixel which is a four-color filter segment in which a filter segment such as white (W) (transparent) with high luminance is added, constitutes one pixel and is arranged. is there. By doing so, the luminance of each pixel is increased by the white pixel which is the filter segment of the fourth color, and the basic performance as a display device is improved (Patent Documents 1 to 3).

  The color filter manufacturing method includes an electrodeposition method, a dyeing method, a printing method, and a pigment dispersion method. Recently, the pigment dispersion method has become the mainstream. The pigment dispersion method is a method in which a color resist in which a pigment is dispersed in a photosensitive resin applied to a substrate or a color paste in which a pigment is dispersed in a non-photosensitive resin is patterned using a photolithography method, and the dyeing process is performed. Since it is unnecessary, the manufacturing process can be simplified, and the obtained colored pixel has the advantage that it has excellent light resistance and heat resistance and can form a highly accurate pixel.

  Furthermore, proposals have been made to prevent a decrease in color density while reducing the size of white pixels compared to other red, green, and blue pixels to improve luminance (Patent Documents 4 and 5).

  As described above, the resin composition for forming the white portion of the four-color filter and the method for producing the four-color filter have been disclosed, but the white pixel and the protective layer are simultaneously formed by the inkjet method. Therefore, it cannot be used for the photolithography method which is the mainstream as the current manufacturing method. In addition, there is no description about the adhesion with the equipment important as a color filter, which is a problem in actual use (Patent Document 6).

  The overcoat agent used as the protective layer is intended to improve adhesion by including an activator such as a silane coupling agent. However, when a large amount of a silane coupling agent is used in the photolithographic method, there arises a new problem that a development residue remains in an unexposed portion of the substrate.

  In order to solve this problem, there has been proposed a method of decomposing and removing the residue by applying ultraviolet rays and ozone to the substrate. However, this proposal has a problem that it takes a long time to remove the residue, and the colored pixels are deteriorated by ultraviolet rays and ozone. In addition, a method is proposed in which ozone treatment is performed after forming a black matrix on a substrate, and then cleaning treatment such as ultrasonic waves is performed with a cleaning liquid containing a nonionic surfactant. However, this method of removing the residue is not necessarily sufficient because it reduces the adhesion of the photosensitive white composition.

Japanese Patent Laid-Open No. 2-118521 JP 11-295717 A Japanese Patent Laid-Open No. 10-10998 JP 2004-102292 A JP 2005-62869 A JP 2007-264378 A

  Accordingly, an object of the present invention is to provide a photosensitive white composition for a color filter that can maintain good pattern adhesion without generating a residue. Another object is to provide a coating film and a color filter formed using the photosensitive white composition for a color filter.

  As means for solving the above-mentioned problems, the invention described in claim 1 includes at least (A) a transparent resin, (B) a photopolymerizable monomer, (C) a photopolymerization initiator, and (D) a surfactant. (E) A white composition for a photosensitive color filter containing a solvent. The contact angle of water to a coating film obtained by applying the white composition for a photosensitive color filter to a substrate and drying is 65 °. It is a white composition for photosensitive color filters characterized by being at least 85 °.

  According to a second aspect of the present invention, there is provided at least a black matrix on a substrate, a white pixel obtained using the white composition for a photosensitive color filter according to the first aspect, and a plurality of colored pixels. It is the color filter characterized by having.

  By adjusting the contact angle of water to the film of the photosensitive white composition forming the pixel of the color filter of the present invention so that the contact angle of water is 65 ° or more and 85 ° or less, adhesion in the development process of the photolithography method is achieved. It is possible to obtain a white composition for a color filter that is excellent in properties and does not leave a development residue, and a color filter that is excellent in adhesion and free from pinholes and foreign matter defects due to the development residue.

  Embodiments of the white composition for a photosensitive color filter of the present invention and a color filter having white pixels and a plurality of colored pixels will be described in detail.

  The color filter of the present invention has at least a black matrix, a plurality of colored pixels, and a white pixel on a substrate.

  As a method for forming colored pixels and a black matrix on a transparent substrate, a pigment dispersion method has become the mainstream. In the pigment dispersion method, a color filter is formed of a plurality of colored layers (red, green, blue, etc.) by patterning a coating layer of a photosensitive coloring composition in which a coloring material such as an organic pigment is dispersed by a known photolithography method. This is a method of forming a pixel. Similarly, the photosensitive white composition of the present invention is patterned by a photolithography method.

  As the transparent substrate, a glass plate such as soda lime glass, low alkali borosilicate glass, non-alkali alumino borosilicate glass or the like is used, and a black matrix shading pattern is first formed in advance on the transparent substrate as described above.

  Using a photosensitive white composition and a photosensitive coloring composition prepared as an alkali development type colored resist material, spray coating, spin coating, and slit coating on a transparent substrate on which BM (black matrix) has been formed for each color. The film is applied by a coating method such as roll coating so that the dry film thickness is 0.5 to 3 μm.

  If necessary, the dried film is exposed to ultraviolet light through a mask having a predetermined pattern provided in contact with or non-contact with the film. Thereafter, the filter is immersed in an aqueous alkaline developer such as sodium carbonate or sodium hydroxide, or sprayed with a developer or the like to remove uncured portions to form a desired pattern, and each color filter including white pixels A segment and a laminated PS (Photo Spacer) are formed.

  The laminated PS is a liquid crystal display device spacer formed by superposing colored layers. Usually, a plurality of photosensitive colored compositions are superimposed on a BM so as not to lower the aperture ratio of the color filter. It is formed. Furthermore, in order to accelerate the polymerization of the photosensitive white composition and the photosensitive coloring composition to form a film, heating (post-baking) is performed as necessary.

  Although there is no limitation on the color order of multiple colors, a transparent white pixel is first formed using the photosensitive white composition of the present invention after BM formation for the convenience of alignment and formability of laminated PS. Thereafter, through the steps of applying a colored layer, exposing, and developing, red pixels, green pixels, blue pixels, and the like are formed.

  In a normal color filter, the BM has a thickness of 0.5 to 3 μm and a width of 3 to 30 μm. This film thickness can be adjusted by the composition and coating method of the photosensitive white composition or the photosensitive coloring composition.

  BM is a thin light-shielding pattern that is formed using a black resin and is formed between pixels in order to increase the contrast of the liquid crystal display device. As the black color material, carbon black, titanium oxide, or a plurality of organic pigments can be used.

  As a method of forming the black matrix layer, a protective resist is formed by a photolithography method using a black non-photosensitive resin, and a matrix or stripe is formed by etching, or a photolithography method using a black photosensitive resin. There is a method of forming in a matrix shape or a stripe shape.

The transparent resin is a resin that disperses a black pigment, a colored pigment, or a transparent extender pigment, and is a resin in which an unexposed portion can be dissolved and removed by an alkaline developer during development after pixel pattern exposure.

  Specifically, acrylic monomers such as alkyl acrylates, cyclic acrylates, cyclic methacrylates, hydroxyethyl ethyl acrylates, hydroxyethyl methacrylates, acrylic transparent resins composed of radical polymerizable monomers having ethylenically unsaturated groups, fluorene skeletons Epoxy acrylate transparent resin having a functional group, and a resin of a type in which a radical polymerizable monomer having an ethylenically unsaturated group is added to a polyfunctional epoxy resin can be used, but the resin is not limited thereto.

  (B) As a photopolymerizable monomer, for example, the following monomers can be mixed or used alone. For example, monomers containing a hydroxyl group such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, Triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tetramethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaerythritol di (meth) ) Acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate , (Meth) acrylic esters such as dipentaerythritol hexa (meth) acrylate, glycerol (meth) acrylate, or pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecanyl Examples include (meth) acrylates, hexa (meth) acrylates of caprolactone adducts of dipentaerystol hexa (meth) acrylate, and melamine (meth) acrylates. A part of the polymerizable monomer is preferably a polymerizable monomer containing a carboxyl group-containing polyfunctional monomer, and may be, for example, pentaerythritol or a derivative thereof.

  Photoinitiators that generate active species that initiate the polymerization reaction of radically polymerizable monomers include tert-butylperoxy-iso-butarate, 2,5-dimethyl-2,5-bis (benzoyldioxy) hexane 1,4-bis [α- (tert-butyldioxy) -iso-propoxy] benzene, di-tert-butyl peroxide, 2,5-dimethyl-2,5-bis (tert-butyldioxy) hexene hydroperoxide, α- (Iso-propylphenyl) -iso-propyl hydroperoxide, 2,5-bis (hydroperoxy) -2,5-dimethylhexane, tert-butyl hydroperoxide, 1,1-bis (tert-butyldioxy) -3,3 , 5-trimethylcyclohexane, butyl-4,4-bis (t-butyl Dioxy) valerate, cyclohexanone peroxide, 2,2 ′, 5,5′-tetra (tert-butylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (ter-butylperoxycarbonyl) benzophenone, 3 , 3 ′, 4,4′-tetra (tert-amylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (tert-hexylperoxycarbonyl) benzophenone, 3,3′-bis (tert-butylperoxy) Carbonyl) -4,4'-dicarboxybenzophenone, tert-butylperoxybenzoate, t-butyldiperoxyisophthalate, and other organic peroxides, 9,10-anthraquinone, 1-chloroanthraquinone 2-chloroanthraquinone, octamethylanthraquinone, 1, - it can be exemplified and quinones such as benz anthraquinone, benzoin methyl, benzoin ethyl ether, alpha-methyl benzoin, and benzoin derivatives such as alpha-phenyl benzoin. Furthermore, examples of the photopolymerization initiator that can be used in the present invention include Irgacure 651, 184, 1173, 907, 369, 379, 819 manufactured by Ciba Specialty Chemicals, TPO manufactured by CGI124 and BASF, Nippon Kayaku In addition to Kayacure DTEX manufactured by Co., Ltd., or benzophenones such as 4,4′-diethylaminobenzophenone and 4,4′-dimethylaminobenzophenone, biimidazole compounds and triazine compounds can be used.

  The photosensitive coloring composition contains an organic solvent in order to sufficiently disperse the pigment in the composition and facilitate application on the substrate. Examples of the organic solvent include cyclohexanone, ethyl cellosolve acetate, butyl cellosolve acetate, 1-methoxy-2-propyl acetate, diethylene glycol dimethyl ether, ethylbenzene, ethylene glycol diethyl ether, xylene, ethyl cellosolve, methyl-n amyl ketone, propylene glycol monomethyl ether toluene, Examples include methyl ethyl ketone, ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone, petroleum solvent, and the like. These can be used alone or in combination.

  As the coloring pigment contained in the photosensitive coloring composition according to the color filter of the present invention, generally available organic pigments can be used. Moreover, a dye, a natural pigment, and an inorganic pigment can be used in combination according to the hue of the filter segment to be formed. As the organic pigment, those having high color developability and high heat resistance, particularly high heat decomposition resistance are preferably used. An organic pigment can be used individually by 1 type or in mixture of 2 or more types. Further, the organic pigment may be refined by salt milling, acid pasting or the like.

  Below, the specific example of the organic pigment which can be used for the photosensitive coloring composition which concerns on the color filter board | substrate of this invention is shown by a color index (CI) number. For the red pixel, for example, C.I. I. Pigment Red 7, 14, 41, 48: 2, 48: 3, 48: 4, 81: 1, 81: 2, 81: 3, 81: 4, 146, 168, 177, 178, 179, 184, 185, Red pigments such as 187, 200, 202, 208, 210, 246, 254, 255, 264, 270, 272, and 279 can be used, and a yellow pigment and an orange pigment can also be used in combination.

  Examples of yellow pigments include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 24, 31, 32, 34, 35, 735: 1, 36, 36: 1, 37, 37: 1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123, 126, 127, 128, 129, 138, 139, 147, 150, 151, 152, 153, 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 179, 18 , And the like 181,182,187,188,193,194,199,198,213,214. Examples of the orange pigment include C.I. I. Pigment Orange 36, 43, 51, 55, 59, 61, 71, 73, etc. can be used.

  In the case where the red pixel contains one or more of diketopyrrolopyrrole red pigment and anthraquinone red pigment among these pigments, it is easy to obtain an arbitrary Rth (retardation value), which is preferable. . This is because the diketopyrrolopyrrole red pigment can be made positive or negative by devising the finer treatment, and its absolute value can be controlled to some extent. In addition, anthraquinone-based red pigments easily obtain Rth close to 0 regardless of the refinement treatment.

The amount used is 10 to 90% by mass of the diketopyrrolopyrrole red pigment and 5 to 70% by mass of the anthraquinone red pigment based on the total mass of the pigment. From the viewpoint of contrast and the like. In particular, when focusing on contrast, it is more preferable that the diketopyrrolopyrrole red pigment is 25 to 75% by mass and the anthraquinone red pigment is 30 to 60% by mass.

  For example, C.I. I. Green pigments such as Pigment Green 7, 10, 36, 37, and 58 can be used, and a yellow pigment can be used in combination. As the yellow pigment, the same pigments as those used for the red pixel can be used.

  Examples of blue pixels include C.I. I. Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64, and the like can be used, and a purple pigment can be used in combination. Examples of purple pigments include C.I. I. PigmentViolet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, 50 and the like.

  When the blue pixel contains at least one of a metal phthalocyanine blue pigment and a dioxazine purple pigment among these pigments, it is easy to obtain a phase difference close to zero. The amount used is 40 to 100% by mass of the metal phthalocyanine blue pigment and 1 to 50% by mass of the dioxazine violet pigment based on the total mass of the pigment. It is preferable from the point. More preferably, the metal phthalocyanine blue pigment is 50 to 98% by mass, and the dioxazine violet pigment is 2 to 25% by mass. In the above, examples of the metal phthalocyanine blue pigment include C.I. I. Pigment Blue 15: 6, and dioxazine-based purple pigments include C.I. I. Pigment Violet 23 is preferable in terms of excellent light resistance, heat resistance, transparency, coloring power, and the like.

  When dispersing the pigment in the resin, a dispersant such as a surfactant, a resin-type pigment dispersant, and a dye derivative can be appropriately used. Further, additives such as a chain transfer agent, a surfactant, and a silane coupling agent may be added for the purpose of improving applicability, improving sensitivity, and improving adhesion.

  Examples of the surfactant include cationic, anionic, nonionic, amphoteric, silicone, and fluorine. Specific examples include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether; polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, and the like. Polyoxyethylene alkylphenyl ethers; polyethylene glycol diesters such as polyethylene glycol dilaurate and polyethylene glycol distearate; sorbitan fatty acid esters; fatty acid-modified polyesters; tertiary amine-modified polyurethanes; polyethyleneimines By name, KP (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow (manufactured by Kyoeisha Chemical Co., Ltd.), F-Top (manufactured by Tochem Products), Mega Fuck (large) This ink chemical industry), Florard (Sumitomo 3M), Asahi Guard, Surflon (Asahi Glass Co., Ltd.), Disperbyk (Bicchemy Japan Co., Ltd.), Solsperse (Generalca Co., Ltd.) )), EFKA (manufactured by EFKA Chemicals Beebuy (EFKA)), and the like. These surfactants can be used alone or in admixture of two or more.

  In the present invention, the contact angle of water with respect to the film obtained by applying a white composition for a photosensitive color filter to a substrate and drying it is effective within a certain range. It is considered that the water solubility (that is, affinity with water) of the dispersant affects the developability.

Therefore, it is an essential requirement to have an appropriate water solubility, and by containing the surfactant in the photosensitive white composition, the contact angle between the membrane and water is small, that is, the affinity for water is high. A coating film can be produced.

  If the contact angle is small, the affinity with water can be increased to prevent generation of residues in the development process, but there is a concern that the adhesion may be deteriorated. It is necessary to balance development adhesion and residue by adjusting the type and amount of the surfactant.

  The photosensitive coloring composition can be produced by mixing each component and making it fine using various dispersing means such as a shaker, a desper, a three-roll mill, a two-roll mill, a sand mill, a kneader, and an attritor. Further, the photosensitive coloring composition is obtained by means of centrifugal separation, sintered filter, membrane filter, or the like, coarse particles of 5 μm or more, preferably coarse particles of 1 μm or more, more preferably coarse particles of 0.5 μm or more, and It is preferable to remove the mixed dust.

  As described above, the photosensitive white composition according to the present invention comprises at least a transparent resin, a photopolymerization monomer, a photopolymerization initiator, and a solvent.

  In the color filter substrate of the present invention, a transparent protective layer may be further formed on the pixel. In a liquid crystal that requires electric field driving in the thickness direction of the liquid crystal cell gap by a transparent electrode, such as a vertically aligned liquid crystal, a liquid crystal called OCB (Optically Compensated Birefringence), a ferroelectric liquid crystal, or a liquid crystal called ECB (Electrically Controlled Birefringence) A step of forming a transparent conductive film can be added after the step of forming and and the step of forming the transparent protective layer.

  In this case, an insulating layer is formed on the transparent electrode on the laminated layer or at a site where the spacer of the counter substrate contacts. This insulating layer may be formed at the same time as the alignment regulating protrusion for the purpose of regulating liquid crystal alignment (alignment control) such as viewing angle and responsiveness improvement. The insulating layer can be omitted as a color filter, for example, in the case of an IPS (lateral electric field) type liquid crystal display device that does not require the formation of a transparent conductive film.

  For example, in a VA liquid crystal display device in which liquid crystal is aligned vertically, a transparent electrode is formed on a black matrix, a white pixel, a colored pixel layer, and a laminated PS in advance, and a transparent resin is further used on the transparent electrode. Alternatively, a spacer or an alignment control protrusion may be formed.

As a method for forming the transparent conductive film, vacuum deposition methods called vapor deposition, ion plating, and sputtering are generally used. For the transparent conductive film, a composite oxide of a metal oxide such as indium, tin, gallium, or zinc can be used.
<Embodiment>
Specific examples of the present invention will be described below. In addition, this invention is not limited to a following example, unless the summary is exceeded. In Examples and Comparative Examples, “part” and “%” mean “part by mass” and “% by mass”, respectively.

  The photosensitive white composition was prepared by stirring and mixing a transparent resin, a photopolymerizable monomer, a photopolymerization initiator, a surfactant, an extender pigment, and an organic solvent so as to be uniform, followed by filtration through a 1 μm filter. The developing agent and adhesiveness were evaluated by changing the contact ratio of the coating film with water by changing the addition ratio of the surfactant to the transparent resin.

  The transparent resin used for the photosensitive white composition is an acrylic resin solution, and the molecular weight of the resin is a weight average molecular weight in terms of polystyrene measured by GPC (gel permeation chromatography). The adjustment is shown below.

  (A) The transparent resin is made of an acrylic resin solution, and adjustment is performed by putting 370 parts of cyclohexanone into a reaction vessel, heating to 80 ° C. while injecting nitrogen gas into the vessel, and starting the following monomers and thermal polymerization at the same temperature. The mixture of the agents was added dropwise over 1 hour to carry out the polymerization reaction. The composition is 20.0 parts of methacrylic acid, 10.0 parts of methyl methacrylate, 55.0 parts of n-butyl methacrylate, 15.0 parts of 2-hydroxyethyl methacrylate, 4 of 2,2′azobisisobutyronitrile. 0.0 parts.

  After completion of the dropwise addition, the mixture was further reacted at 80 ° C. for 3 hours, then 1.0 part of azobisisobutyronitrile dissolved in 50 parts of cyclohexanone was added, and the reaction was further continued at 80 ° C. for 1 hour, An acrylic resin solution was obtained. The mass average molecular weight Mw of this acrylic resin was about 40000. After cooling to room temperature, about 2 g of the resin solution is sampled and heated to dryness at 180 ° C. for 20 minutes, and the non-volatile content is measured. Based on the measurement result, the previously synthesized acrylic resin solution has a non-volatile content of 30%. Cyclohexanone was added to to prepare an acrylic resin solution.

  In addition, (B) the photopolymerization monomer is “Aronix M402” manufactured by Toagosei Co., Ltd., (C) the photopolymerization initiator is “Irgacure 907” manufactured by Ciba Specialty Chemicals, and (D) the surfactant is Sumitomo 3M. A photosensitive white composition was obtained using Fluorad FC-430, (E) machine solvent EEP (ethyl-3-ethoxypropionate) / cyclohexanone.

  Six types of photosensitive white compositions were prepared. (A) 100 parts of a transparent resin, (B) 50 parts of a photopolymerizable monomer, (C) 39.9 parts of a photopolymerization initiator, and (E) 100 parts of an organic solvent. On the other hand, the addition amount of (D) surfactant was changed to 2.5 parts, 2.0 parts, 1.0 parts, 0.75 parts, 0.5 parts, and 0.4 parts.

The obtained photosensitive white composition was applied to a glass substrate by spinless coating so that the finished film thickness was 2.0 μm. After drying at 90 ° C. for 5 minutes, light from a high-pressure mercury lamp was irradiated through a striped photomask for forming a white pixel at 300 mJ / cm ² . Ion exchange water was dropped on the white coating film after exposure, and the contact angle after 10 seconds was measured.

  (D) The contact angle changed to 105 °, 96 °, 85 °, 70 °, 65 °, and 63 ° depending on the amount of the surfactant added.

The photosensitive white composition irradiated with light through the striped photomask was developed with an alkaline developer for 60 seconds to develop a white coating film for 60 seconds to obtain a striped white pixel. Thereafter, the film was hardened at 230 ° C. for 30 minutes to obtain a white pixel. The alkali developer was 1.5% by weight of sodium carbonate, 0.5% by weight of sodium hydrogen carbonate, an anionic surfactant (Kao Perirex NBL) was adjusted to 8.0% by weight and water was adjusted to 90.0% by mass.

  (D) The developability and adhesion of the photosensitive white composition with the contact angle varied depending on the amount of the surfactant added. Regarding the developability, the presence / absence of residues is visually confirmed and judged, and those with no residue are evaluated as “Good” for developability, and those with the occurrence of residue are determined as “Poor” for developability. . Regarding adhesion, the presence or absence of peeling was judged by visual inspection, and no peeling occurred, and “×” indicates poor adhesion, and “×” indicates poor adhesion. The results are shown in Table 1.

界面活性剤の量によって、白色塗膜に対する水の接触角を調整でき、界面活性剤の添加量が少なく、乾燥して得られた塗膜に対する水の接触角が６５°以下であると密着性が悪くなった。逆に、界面活性剤の添加量が多く、乾燥して得られた塗膜に対する水の接触角が８５°以上になると、現像性が悪くなり残渣の発生が見られることが分かった。

The contact angle of water with respect to the white coating film can be adjusted by the amount of the surfactant, the addition amount of the surfactant is small, and the contact angle of water with respect to the coating film obtained by drying is 65 ° or less. Became worse. On the contrary, it was found that when the amount of the surfactant added was large and the contact angle of water with respect to the coating film obtained by drying was 85 ° or more, the developability deteriorated and the generation of residues was observed.

  It has been shown that by reducing this contact angle, residues in development can be reduced, and if it is too low, there is an adverse effect on adhesion, so the contact angle of water on the coating film obtained by drying is It turned out that it is required as a white composition for photosensitive color filters that it is 65 degrees or more and 85 degrees or less.

  The color filter produced using the white composition for photosensitive color filters whose water contact angle with respect to the coating film obtained by drying is 65 ° or more and 85 ° or less is good without pinholes and foreign matter defects caused by foreign matter. I also found that I can display images.

Claims (2)

  A white composition for a photosensitive color filter containing at least (A) a transparent resin, (B) a photopolymerizable monomer, (C) a photopolymerization initiator, (D) a surfactant, and (E) a solvent. A white composition for a photosensitive color filter, wherein a contact angle of water to a coating film obtained by applying a white composition for a photosensitive color filter to a substrate and drying is 65 ° to 85 °.   A color filter comprising at least a black matrix, a white pixel obtained using the white composition for a photosensitive color filter according to claim 1, and a plurality of colored pixels.