JP5035309B2 - Photosensitive coloring composition, color filter formed using the same, and method for producing color filter - Google Patents

Description

  The present invention relates to a photosensitive coloring composition, a color filter for a transflective liquid crystal display device formed using the same, and a method for producing the same.

Since liquid crystal display devices are not self-luminous display devices, they require light from other sources for display, and are roughly classified into two types, transmissive liquid crystal display devices and reflective liquid crystal display devices, depending on the light source. The transmissive liquid crystal display device performs display using light from a backlight provided behind the transmissive liquid crystal display device, and is mainly used in a dark environment such as indoors. In addition, the reflective liquid crystal display device reflects external light from the surroundings when viewing the liquid crystal display device by a reflective layer provided behind the reflective liquid crystal display device, and performs display using the reflected light. It is used in such a very bright environment.
However, the transmissive liquid crystal display device has a drawback that its display is difficult to see in a very bright environment such as outdoors. In addition, the reflective liquid crystal display device is mainly used in a very bright environment such as outdoors, and has a drawback that its display is difficult to see in a dark environment such as indoors.

In order to eliminate the drawbacks of the transmissive liquid crystal display device and the reflective liquid crystal display device, a transflective liquid crystal display device having both functions of a transmissive type and a reflective type has been developed. This transflective liquid crystal display device can be used in a very bright environment such as outdoors or in a dark environment such as indoors, and is expected as a liquid crystal display device used in mobile devices.
The transflective liquid crystal display device includes a color filter, a transparent electrode formed on the color filter, a liquid crystal, a TFT substrate on which a TFT element is formed, a transparent electrode and a reflective electrode formed on the TFT substrate. . The color filter has a black matrix and colored pixels formed on a glass substrate. Further, the transparent electrode and the reflective electrode are connected to the drain electrode of the TFT element.

One colored pixel is composed of a light transmission region and a light reflection region, excluding the black matrix. The light transmissive area is an area that functions as a transmissive liquid crystal display device. In the light transmissive area, white light from the backlight passes through the TFT substrate, transparent electrode, liquid crystal, and transparent electrode, passes through the colored pixels, and becomes colored light. It comes to inject.
The light reflection area is an area that functions as a reflective liquid crystal display device. In the light reflection area, external light from the surroundings passes through the glass substrate and the colored pixels to become colored light, and then is reflected by the reflective electrode. It is designed to inject outside again. This transflective liquid crystal display device turns on the backlight to function as a transmissive liquid crystal display device in a dark environment such as indoors, and turns off the backlight in a very bright environment such as outdoors. Thus, it is used by functioning as a reflective liquid crystal display device.

  Colored pixels of a color filter constituting a transflective liquid crystal display device are (1) a method of providing a minute transparent region, that is, a hole in a part of a light reflecting region, or (2) light having a different film thickness in one pixel. It is formed by a method of providing a transmission region and a light reflection region. In the method (1) of providing holes, the difference between transmissive display and reflective display can be reduced by optimizing the shape and size of the holes. In addition, since holes can be formed at the same time when patterning colored pixels, an inexpensive color filter can be obtained without increasing the number of steps of coating formation.

  However, in the method of providing holes in (1), the flatness of the color filter is deteriorated when the unevenness difference of the colored pixels is increased, and there is a risk that display defects are likely to occur when the liquid crystal panel is used. The flatness of the color filter can be improved to some extent by applying an overcoat. However, if the hole size is small, the overcoat is difficult to flow into the hole and may not be sufficiently flattened. is there. Further, when the film thickness difference between the hole portion and the surrounding area is large, it is necessary to increase the overcoat film thickness. However, if the overcoat film thickness becomes too large, there is a concern that film thickness unevenness is likely to occur when a liquid crystal display element is formed due to a decrease in film hardness of the entire color filter, or cracks are likely to occur in the overcoat due to thermal stress. Therefore, an excessive increase in film thickness is not preferable.

  On the other hand, in the method (2), display defects due to poor flatness of the color filter are unlikely to occur. However, when the light transmission region and the light reflection region having different thicknesses are formed by laminating a plurality of color materials, the color material is applied twice or more to form a colored pixel, which is costly. Problems arise. Further, in the case where the light transmission region and the light reflection region having different film thicknesses are formed by changing the effective exposure amount in the region corresponding to each of the regions and exposing the coating film of the photosensitive coloring composition, it is costly. No problem arises, but the light-sensitive areas and light-reflective areas with different film thicknesses are formed even if the effective exposure amount is changed and exposed to the coating film of the photosensitive coloring composition containing one conventional photopolymerization initiator. It was difficult to do.

JP 2002-365422 A JP 2003-107232 A

The present invention is a color filter comprising a colored pixel composed of a colored layer for a light transmission region and a colored layer for a light reflection region formed using the same photosensitive colored resin composition, the color filter comprising the color filter When a transflective liquid crystal display device is used as a transmissive liquid crystal display device, a transmissive color display having excellent brightness and saturation is provided as a transmissive liquid crystal display device, and when used as a reflective liquid crystal display device. Another object of the present invention is to provide a color filter for a transflective liquid crystal display device capable of performing a reflective color display having brightness and saturation excellent as a reflective liquid crystal display device without becoming dark.
In addition, the present invention provides a colored layer consisting of a colored layer for a light transmitting region and a colored layer for a light reflecting region by irradiating and developing ultraviolet rays through a photomask having a total light shielding region, a semi-light shielding region, and a total transmission region. It is an object of the present invention to provide a photosensitive coloring composition capable of forming a pixel and capable of producing a color filter having excellent characteristics as described above.
In addition, the present invention uses a photomask having a total light-shielding region, a semi-light-shielding region, and a total transmission region, and easily and inexpensively manufactures a color filter for a transflective liquid crystal display device having the above-described excellent characteristics. It is an object to provide a method.

The photosensitive coloring composition of the present invention is a photosensitive coloring composition comprising a photopolymerization initiator, an ethylenically unsaturated monomer, an alkali-soluble resin, and a coloring agent,
The photopolymerization initiator has an ethyl 4--4- molar extinction coefficient of 8000 L / mol · cm or more and 60000 L / mol · cm or less in an acetonitrile solution at a wavelength where the molar extinction coefficient is maximum at a wavelength of 300 to 450 nm. Dimethylaminobenzoate, 2-ethylhexyl-4-dimethylaminobenzoate, 1,2-octadion-1- [4- (phenylthio)-, 2- (O-benzoyloxime)], 2-methyl-1- [4- ( Photopolymerization initiator selected from the group consisting of (methylthio) phenyl] -2-morpholinopropan-1-one and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one ( a1) and 2,2-dimethoxy-1,2-diphenylethane having a molar extinction coefficient at a wavelength where the molar extinction coefficient is maximum in the wavelength range is 5000 L / mol · cm or less in an acetonitrile solution. A photopolymerization initiator (a2) selected from the group consisting of -1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one,
The dried coating film of the photosensitive coloring composition was exposed to ultraviolet light with an illuminance of 22 mW / cm ² for 13 seconds using a super high pressure mercury lamp through a photomask having a light shielding part and an opening, and then the unexposed part was developed. The thickness of the coating film after t1 is set, and the dried coating film is exposed to ultraviolet rays with an illuminance of 12 mW / cm ² for 13 seconds using an ultra-high pressure mercury lamp, and then the unexposed portion is developed. When t2 is t2, t2 / t1 is 0.05 or more and 0.75 or less.
In addition, the color filter of the present invention is formed using a colored layer for a light transmission region formed using the photosensitive coloring composition of the present invention and the same photosensitive coloring composition as the photosensitive coloring composition. And a pixel composed of a colored layer for a light reflection region having a thickness of 5 to 75% with respect to the thickness of the colored layer for the light transmission region, and having a light transmission region and a light reflection region in one pixel. It is used for a transflective liquid crystal display device.
Further, the method for producing a color filter for a transflective liquid crystal display device of the present invention includes a step of applying and drying the photosensitive coloring composition of the present invention on a transparent substrate, and a total light shielding region and a color for a light reflecting region. In response to the formation of the layer, ultraviolet light is irradiated through a photomask having a semi-light-shielding region whose optical density is lower than the optical density of the whole light-shielding region and a total transmission region corresponding to the formation of the colored layer for the light transmission region. And a developing step.

  By using the photosensitive coloring composition of the present invention, the colored layer for the light transmission region and the colored layer for the light reflection region of the color filter for the transflective liquid crystal display device are manufactured with the same photosensitive coloring composition. Since it can be formed without increasing the number of steps, a color filter for a transflective liquid crystal display device with good visibility can be easily and inexpensively manufactured.

First, the photosensitive coloring composition of this invention is demonstrated.
The photosensitive coloring composition of the present invention is a photosensitive coloring composition comprising a photopolymerization initiator, an ethylenically unsaturated monomer, an alkali-soluble resin, and a coloring agent,
The photopolymerization initiator has an ethyl 4--4- molar extinction coefficient of 8000 L / mol · cm or more and 60000 L / mol · cm or less in an acetonitrile solution at a wavelength where the molar extinction coefficient is maximum at a wavelength of 300 to 450 nm. Dimethylaminobenzoate, 2-ethylhexyl-4-dimethylaminobenzoate, 1,2-octadion-1- [4- (phenylthio)-, 2- (O-benzoyloxime)], 2-methyl-1- [4- ( Photopolymerization initiator selected from the group consisting of (methylthio) phenyl] -2-morpholinopropan-1-one and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one ( a1) and 2,2-dimethoxy-1,2-diphenylethane having a molar extinction coefficient at a wavelength where the molar extinction coefficient is maximum in the wavelength range is 5000 L / mol · cm or less in an acetonitrile solution. A photopolymerization initiator (a2) selected from the group consisting of -1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one,
The dried coating film of the photosensitive coloring composition was exposed to ultraviolet light with an illuminance of 22 mW / cm ² for 13 seconds using a super high pressure mercury lamp through a photomask having a light shielding part and an opening, and then the unexposed part was developed. The thickness of the coating film after t1 is set, and the dried coating film is exposed to ultraviolet rays with an illuminance of 12 mW / cm ² for 13 seconds using an ultra-high pressure mercury lamp, and then the unexposed portion is developed. T2 / t1 is 0.05 or more and 0.75 or less, where t2 is t2.
When t2 / t1 is greater than 0.75, the thickness of the colored layer for the light reflection region increases, and the reflected color display of the liquid crystal display device becomes dark. On the other hand, if t2 / t1 is less than 0.05, the thickness of the colored layer for the light reflecting region becomes too small, and the colored layer for the light reflecting region may be peeled off in the development process.
In the present invention, the ultra-high pressure mercury lamp refers to a lamp composed of a lamp having a relative intensity of 5: 24: 100 of emission lines having wavelengths of 316 nm, 335 nm, and 365 nm. The illuminance refers to illuminance measured by a measuring instrument that measures the illuminance of a bright line having a wavelength of 365 nm.

  In the photosensitive coloring composition of the present invention, as a photopolymerization initiator, the molar extinction coefficient ε (λa) at a wavelength (λa) at which the molar extinction coefficient is maximum at a wavelength of 300 to 450 nm in an acetonitrile solution is 8000 L / mol · cm. More than 60000 L / mol · cm, more preferably 9500 L / mol · cm or more and 50000 L / mol · cm or less, a photopolymerization initiator (a1) and a molar extinction coefficient at 300 to 450 nm in acetonitrile solution. A photopolymerization initiator (a2) having a molar extinction coefficient ε (λb) of 5000 L / mol · cm or less at the maximum wavelength λb is used in combination.

Here, when only the photopolymerization initiator (a1) having a high molar extinction coefficient is used, the photosensitive coloring composition is cured more than necessary, so that the conditions of low illuminance and low exposure amount are provided through the semi-light-shielding portion of the photomask. The thickness of the colored layer for the reflective region formed by exposure below increases, and the reflected color display of the liquid crystal display device becomes dark. In addition, when only the photopolymerization initiator (a2) having a low molar extinction coefficient is used, the efficiency of generating radicals is lowered, so that it is difficult to obtain a sufficient cured coating film.
Use of a photopolymerization initiator having an ε (λa) greater than 60000 L / mol · cm is not preferable because light hardly penetrates to the deep part of the coating film of the photosensitive coloring composition.

As the photopolymerization initiator (a1), ethyl-4-dimethylaminobenzoate, 2-ethylhexyl-4-dimethylaminobenzoate, 1,2-octadion-1- [4- (phenylthio)-, 2- (O-benzoyl) Oxime)], 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane- It is a photopolymerization initiator selected from the group consisting of 1-one.
As the photopolymerization initiator (a2), 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propane-1- It is a photopolymerization initiator selected from the group consisting of ON.
The use amount of the photopolymerization initiator (a2) is preferably 1 to 90% by weight, more preferably 10 to 80% by weight, based on the use amount of the photopolymerization initiator (a1).

  The content of the photopolymerization initiator is usually preferably 0.5 to 20% by weight, more preferably 1 to 15% by weight based on the solid content of the photosensitive coloring composition. When the content of the photopolymerization initiator is less than 0.5% by weight, a sufficient cured coating film cannot be obtained by irradiation with ultraviolet rays, and when it exceeds 20% by weight, the colored layer for the reflective region is cured more than necessary. The thickness increases, and the reflected color display of the liquid crystal display device becomes dark.

  Examples of the photopolymerization initiator include methylphenylglyoxylate, benzyl, 9,10-phenanthrenequinone, camphorquinone, ethylanthraquinone, 4,4′-diethylisophthalophenone, 3,3 ′, 4,4. Compounds such as' -tetra (t-butylperoxycarbonyl) benzophenone and 4,4'-diethylaminobenzophenone can be used in combination as a sensitizer.

  The colorant contained in the photosensitive coloring composition of the present invention is not particularly limited in hue, is appropriately selected according to the use of the obtained color filter, and may be an organic colorant or an inorganic colorant. The organic colorant specifically means a dye, an organic pigment, a natural pigment, and the like, and the inorganic colorant specifically means an inorganic salt other than an inorganic pigment, an inorganic salt called an extender pigment, Since color filters require high-definition color development and heat resistance, the colorant is preferably a colorant having high color developability and high heat resistance, particularly a colorant having high heat decomposability, usually organic coloring. Agents, particularly preferably organic pigments, are used. The color index (C.I.) numbers of organic pigments classified as Pigment in the Color Index (C.I .; published by The Society of Dyers and Colorists) are shown below for each hue.

  Examples of yellow pigments include CI Pigment Yellow 1, CI Pigment Yellow 3, CI Pigment Yellow 12, CI Pigment Yellow 13, CI Pigment Yellow 14, CI Pigment Yellow 15, CI Pigment Yellow 16, CI Pigment Yellow 17, CI Pigment Yellow 20, CI Pigment Yellow 24, CI Pigment Yellow 31, CI Pigment Yellow 55, CI Pigment Yellow 60, CI Pigment Yellow 61, CI Pigment Yellow 65, CI Pigment Yellow 71, CI Pigment Yellow 73, CI Pigment Yellow 74, CI Pigment Yellow 81, CI Pigment Yellow 83, CI Pigment Yellow 93, CI Pigment Yellow 95, CI Pigment Yellow 97, CI Pigment Yellow 98, CI Pigment Yellow 100, CI Pigment Yellow 101, CI Pigment Yellow 104, CI Pigment Yellow 106, CI Pigment Yellow 108, CI Pigment Yellow 109, CI Pigment Yellow 110, CI Pigment Yellow 113, CI Pigment Yellow 114, CI Pigment Yellow 116, CI Pigment Yellow 117, CI Pigment Yellow 119, CI Pigment Yellow 120, CI Pigment Yellow 126, CI Pigment Yellow 127, CI Pigment Yellow 128, CI Pigment Yellow 129, CI Pigment Yellow 138, CI Pigment Yellow 139, CI Pigment Yellow 150, CI Pigment Yellow 151, CI Pigment Yellow 152, CI Pigment Yellow 153, CI Pigment Yellow 154, C.I. Pigment Yellow 155, C.I. Pigment Yellow 156, C.I. Pigment Yellow 166, C.I. Pigment Yellow 168, C.I. Pigment Yellow 175, and the like.

Examples of the orange pigment include CI pigment orange 1, CI pigment orange 5, CI pigment orange 13, CI pigment orange 14, CI pigment orange 16, CI pigment orange 17, CI pigment orange 24, CI pigment orange 34, CI pigment orange 36, CI Pigment Orange 38, CI Pigment Orange 40, CI Pigment Orange 43, CI Pigment Orange 46, CI Pigment Orange 49, CI Pigment Orange 51, CI Pigment Orange 61, CI Pigment Orange 63, CI Pigment Orange 64, CI Pigment Orange 71, CI pigment orange 73 and the like.
Examples of purple pigments include CI Pigment Violet 1, CI Pigment Violet 19, CI Pigment Violet 23, CI Pigment Violet 29, CI Pigment Violet 32, CI Pigment Violet 36, CI Pigment Violet 38, and the like.

  Examples of red pigments include CI Pigment Red 1, CI Pigment Red 2, CI Pigment Red 3, CI Pigment Red 4, CI Pigment Red 5, CI Pigment Red 6, CI Pigment Red 7, CI Pigment Red 8, CI Pigment Red 9, CI Pigment Red 10, CI Pigment Red 11, CI Pigment Red 12, CI Pigment Red 14, CI Pigment Red 15, CI Pigment Red 16, CI Pigment Red 17, CI Pigment Red 18, CI Pigment Red 19, CI Pigment Red 21, CI Pigment Red 22, CI Pigment Red 23, CI Pigment Red 30, CI Pigment Red 31, CI Pigment Red 32, CI Pigment Red 37, CI Pigment Red 38, CI Pigment Red 40, C .I. Pigment Red 41, CI Pigment Red 42, CI Pigment Red 48: 1, CI Pigment Red 48: 2, CI Pigment Red 48: 3, CI Pigment Red 48: 4, CI Pigment Red 49: 1, CI Pigment Red 49: 2, CI Pigment Red 50: 1, CI Pigment Red 52: 1, CI Pigment Red 53: 1, CI Pigment Red 57, CI Pigment Red 57: 1, CI Pigment Red 58: 2, CI Pigment Red 58: 4 CI Pigment Red 60: 1, CI Pigment Red 63: 1, CI Pigment Red 63: 1, CI Pigment Red 64: 1, CI Pigment Red 81: 1, CI Pigment Red 83, CI Pigment Red 88, CI Pigment Red 90 : 1, CI Pigment Red 97, CI CI Pigment Red 101, CI Pigment Red 102, CI Pigment Red 104, CI Pigment Red 105, CI Pigment Red 106, CI Pigment Red 108, CI Pigment Red 112, CI Pigment Red 113, CI Pigment Red 114, CI Pigment Red 122, CI CI Pigment Red 123, CI Pigment Red 144, CI Pigment Red 146, CI Pigment Red 149, CI Pigment Red 150, CI Pigment Red 151, CI Pigment Red 166, CI Pigment Red 168, CI Pigment Red 170, CI Pigment Red 171 and CI Pigment Red 172, CI Pigment Red 174, CI Pigment Red 175, CI Pigment Red 176, CI Pigment Red 177, CI CI Pigment Red 178, CI Pigment Red 179, CI Pigment Red 180, CI Pigment Red 185, CI Pigment Red 187, CI Pigment Red 188, CI Pigment Red 190, CI Pigment Red 193, CI Pigment Red 194, CI Pigment Red 202, CI CI Pigment Red 206, CI Pigment Red 207, CI Pigment Red 208, CI Pigment Red 209, CI Pigment Red 215, CI Pigment Red 216, CI Pigment Red 220, CI Pigment Red 224, CI Pigment Red 226, CI Pigment Red 242, CI Pigment Red 243, CI Pigment Red 245, CI Pigment Red 254, CI Pigment Red 255, CI Pigment Red 264, CI Pigment Red 265, and the like.

Examples of the blue pigment include CI pigment blue 15, CI pigment blue 15: 3, CI pigment blue 15: 4, CI pigment blue 15: 6, CI pigment blue 60, and the like.
Examples of green pigments include CI Pigment Green 7 and CI Pigment Green 36.
Examples of the brown pigment include CI pigment brown 23 and CI pigment brown 25.
Examples of black pigments include CI Pigment Black 1 and Pigment Black 7.
These organic pigments can be used alone or in admixture of two or more.

Specific examples of the inorganic colorant or extender include titanium oxide, barium sulfate, calcium carbonate, zinc white, lead sulfate, yellow lead, zinc yellow, red rose (red iron (III) oxide), cadmium red, ultramarine blue. , Bitumen, chromium oxide green, cobalt green, amber, titanium black, synthetic iron black, carbon black and the like. These inorganic colorants or extender pigments can be used alone or in admixture of two or more.
The content of the colorant is usually preferably 1 to 80% by weight, more preferably 2 to 70% by weight based on the solid content of the photosensitive coloring composition. If the content of the colorant is less than 1% by weight, the film thickness of the color filter becomes excessively thick, which is not preferable, and if it exceeds 70% by weight, a good dispersion state cannot be obtained.

Colorants can be used with dispersants if desired. Examples of the dispersant include a surfactant, a resin-type dispersant, and a pigment derivative.
Surfactants include sodium lauryl sulfate, polyoxyethylene alkyl ether sulfate, sodium dodecylbenzene sulfonate, alkali salt of styrene-acrylic acid copolymer, sodium stearate, sodium alkyl naphthalene sulfonate, sodium alkyl diphenyl ether disulfonate. , Lauryl sulfate monoethanolamine, lauryl sulfate triethanolamine, ammonium lauryl sulfate, monoethanolamine stearate, sodium stearate, sodium lauryl sulfate, monoethanolamine of styrene-acrylic acid copolymer, polyoxyethylene alkyl ether phosphate Anionic surfactants such as: polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene Nonionic surfactants such as nylphenyl ether, polyoxyethylene alkyl ether phosphate ester, polyoxyethylene sorbitan monostearate, polyethylene glycol monolaurate; chaotic properties such as alkyl quaternary ammonium salts and their ethylene oxide adducts Surfactants: Examples include amphoteric surfactants such as alkylbetaines such as alkyldimethylaminoacetic acid betaine and alkylimidazolines, and these can be used alone or in admixture of two or more. The amount of the surfactant used is usually 50 parts by weight or less, preferably 30 parts by weight or less with respect to 100 parts by weight of the colorant.

  The resin-type dispersant has a colorant-affinity part having the property of adsorbing to the colorant and a part compatible with the alkali-soluble resin, and adsorbs to the colorant to disperse the colorant into the alkali-soluble resin. It works to stabilize. Specific examples of resin-type dispersants include polycarboxylic acid esters such as polyurethane and polyacrylate, unsaturated polyamides, polycarboxylic acids, polycarboxylic acid (partial) amine salts, polycarboxylic acid ammonium salts, and polycarboxylic acid alkylamine salts. , Polysiloxane, long-chain polyaminoamide phosphate, hydroxyl group-containing polycarboxylic acid ester, modified products thereof, amides formed by reaction of poly (lower alkyleneimine) and polyester having a free carboxyl group, and salts thereof Water-soluble such as (meth) acrylic acid-styrene copolymer, (meth) acrylic acid- (meth) acrylic acid ester copolymer, styrene-maleic acid copolymer, polyvinyl alcohol, polyvinylpyrrolidone Resin, water-soluble polymer, polyester, Polyacrylate, ethylene oxide / propylene oxide addition compound, phosphate ester-based and the like are used, it can be used alone or in admixture of two or more. The amount of the resin-type dispersant used is usually 50 parts by weight or less, preferably 30 parts by weight or less with respect to 100 parts by weight of the colorant.

  The dye derivative is a compound in which a substituent is introduced into an organic dye, and the organic dye includes a light yellow aromatic polycyclic compound such as a naphthalene-based or anthraquinone-based compound that is not generally called a dye. Examples of the dye derivatives are described in JP-A-63-305173, JP-B-57-15620, JP-B-59-40172, JP-B-63-17102, JP-B-5-9469, and the like. These can be used alone or in combination of two or more. 0.1-30 weight part is preferable with respect to 100 weight part of coloring agents, and, as for the usage-amount of a pigment derivative, 0.5-20 weight part is more preferable. When the amount is less than 0.1 parts by weight, the effect of adding the pigment derivative is hardly exhibited, and when the amount is more than 30 parts by weight, the dispersion becomes unstable, which is not preferable.

Examples of the ethylenically unsaturated monomer contained in the photosensitive coloring composition of the present invention include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, and polyethylene glycol di (meth). ) Acrylates, pentaerythritol tri (meth) acrylates, dipentaerythritol hexa (meth) acrylates, tricyclodecanyl (meth) acrylates, melamine (meth) acrylates, epoxy (meth) acrylates and various acrylic and methacrylic esters , (Meth) acrylic acid, (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, styrene, vinyl acetate, acrylonitrile and the like.
The content of the ethylenically unsaturated monomer is usually preferably 1 to 80% by weight, more preferably 3 to 70% by weight based on the solid content of the photosensitive coloring composition. If the content of the ethylenically unsaturated monomer is less than 1% by weight, a sufficient cured coating film cannot be obtained by irradiation with ultraviolet rays, and if it exceeds 80% by weight, the colored layer for the reflective region is cured more than necessary. Therefore, the film thickness is increased and the reflected color display of the liquid crystal display device is darkened.

The alkali-soluble resin contained in the photosensitive coloring composition of the present invention is a resin having an acid value, and is used for making the photosensitive coloring composition of the present invention an alkali developing type. As the alkali-soluble resin, since a high-temperature heating process is performed in the manufacturing process of the color filter, it is preferable to use a resin having good resistance even in the heating process. Furthermore, in the color filter manufacturing process, treatment with various solvents and chemicals is also performed. Therefore, it is preferable to use a resin excellent in solvent resistance and chemical resistance.
Examples of the alkali-soluble resin include (meth) acrylic acid copolymers, styrene-maleic acid copolymers, and polyester resins having a carboxyl group.

In addition to the alkali-soluble resin, the photosensitive coloring composition of the present invention may contain a resin that does not have alkali solubility for the purpose of imparting characteristics such as heat resistance and adhesion.
Resins that do not have alkali solubility include thermoplastic resins, thermosetting resins, and photosensitive resins. Examples of the thermoplastic resin include butyral resin, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyurethane resin, polyester resin, acrylic resin, alkyd resin, Examples include styrene resins, polyamide resins, rubber resins, cyclized rubber resins, celluloses, polybutadiene, and polyimide resins. Moreover, as a thermosetting resin, an epoxy resin, a phenol resin, a benzoguanamine resin, a melamine resin, a urea resin etc. are mentioned, for example.

  As the photosensitive resin, a (meth) acrylic compound, cinnamic acid, or the like is bonded to a linear polymer having a reactive substituent such as a hydroxyl group, a carboxyl group, or an amino group via an isocyanate group, an aldehyde group, an epoxy group, or the like. A resin into which a photocrosslinkable group is introduced is used. Further, a linear polymer containing an acid anhydride such as a styrene-maleic anhydride copolymer or an α-olefin-maleic anhydride copolymer is converted into a (meth) acrylic compound having a hydroxyl group such as hydroxyalkyl (meth) acrylate. Half-esterified polymers can also be used.

  In the photosensitive coloring composition of the present invention, a colorant can be sufficiently dispersed, and a solvent can be contained in order to apply a desired film thickness on a transparent substrate. Examples of the 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, methyl ethyl ketone. , Ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone, petroleum solvent and the like, and these are used alone or in combination.

In addition to the above, the photosensitive coloring composition of the present invention includes a chain transfer agent, a surfactant, and other known substances for the purpose of improving the coating property of the photosensitive coloring composition, improving the sensitivity, and improving the adhesion. These additives may be added as necessary.
The photosensitive coloring composition is obtained by using a centrifugal separator, a sintered filter, a membrane filter, or the like to provide coarse particles of 5 μm or more, preferably coarse particles of 1 μm or more, more preferably 0.5 μm or more and coarse particles. Is preferably removed.

Next, the color filter of the present invention and the manufacturing method thereof will be described.
The color filter of the present invention is formed using a colored layer for a light transmission region formed using the photosensitive coloring composition of the present invention, and the same photosensitive coloring composition as the photosensitive coloring composition, A color filter comprising pixels comprising a light reflecting region colored layer having a thickness of 5 to 75 with respect to the thickness of the light transmitting region colored layer, wherein the light transmitting region and the light reflecting region are provided in one pixel. It is used for a transflective liquid crystal display device.
When the thickness of the colored layer for the light reflecting region is less than 5% with respect to the thickness of the colored layer for the light transmitting region, the thickness of the colored layer for the light reflecting region is extremely thin, and the coloring for the light reflecting region is performed in the development process. If the thickness of the colored layer for the light reflection region exceeds 75% of the thickness of the colored layer for the light transmission region, the reflected color display becomes dark. The object of the invention cannot be achieved.

The color of the pixels constituting the color filter of the present invention is selected from about 2 to 6 colors from blue, green, red, cyan, yellow, magenta, orange, purple and the like.
The color filter is formed with a black matrix that is a light shielding region for the purpose of improving the contrast of the liquid crystal display device. As the black matrix, a metal thin film (thickness of about 0.1 to 0.2 μm) such as Cr, Al, or Ni or a resin black matrix in which a light shielding material is dispersed in a resin is usually used.

The color filter of the present invention corresponds to the step of applying and drying the photosensitive coloring composition of the present invention on a transparent substrate, and the formation of the entire light-shielding region and the colored layer for the light reflection region, and the optical density thereof is all. It can be manufactured through a process of irradiating with ultraviolet rays through a photomask having a semi-light-shielding region lower than the optical density of the light-shielding region and a total transmission region corresponding to the formation of the colored layer for the light transmission region, and developing.
Specifically, the color filter of the present invention is formed by applying the photosensitive coloring composition of the present invention on a transparent substrate by a coating method such as spin coating, slit coating, roll coating, and the like, and drying it through a photomask. After irradiating with ultraviolet rays from the coated side of the coloring composition, the developer is immersed in a solvent or an alkali developer or sprayed with a developer to remove unexposed areas, i.e. uncured areas, and develop. It can manufacture by forming the pattern of. The coating thickness of the photosensitive coloring composition is preferably in the range of 0.2 to 6 μm (when dried), and more preferably in the range of 0.5 to 5 μm in terms of coating properties.

  The photomask has three types of regions. That is, it has a total light shielding region with a transmittance of 0%, a total transmission region with a transmittance of 100%, and a semi-light shielding region with a transmittance of 0 to 100% and an optical density lower than the optical density of the total light shielding region. When irradiating with ultraviolet rays, the total light shielding area is completely unexposed, the total transmission area is fully exposed, and the semi-light-shielding area is adjusted to be in an exposure state with a low illuminance and a low exposure amount compared to the total transmission area, Three types of regions having different solubility in the developer can be formed. For example, when a negative resist is used, the entire exposed region has low solubility, and a thick film region suitable for the light transmitting region of the color filter can be formed, and the unexposed region is completely dissolved. A part of the semi-light-shielding region is dissolved, and the film thickness of the coating film is smaller than that of the entire exposed portion. That is, a low film thickness region suitable for the reflective region of the color filter can be formed by half-etching the coating film. As a method for forming the semi-light-shielding region in the photomask, there is a method in which a part of the photomask is slit or meshed.

As the ultraviolet light, for example, light using a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, a gallium lamp, a xenon lamp, a carbon arc lamp, or the like as a light source can be used. Specifically, an ultra-high pressure mercury lamp or a xenon mercury lamp is often used because of the point light source and the stability of luminance. The amount of ultraviolet rays irradiated from the photosensitive coloring composition coated surface side, can be appropriately set within a range of 5~1000mJ / cm ^2, it is preferably in the range on the easy of 30~300mJ / cm ² management process.
As the alkali developer, an aqueous solution such as sodium carbonate or sodium hydroxide is used, and an organic alkali such as dimethylbenzylamine or triethanolamine can also be used. Moreover, an antifoamer and surfactant can also be added to a developing solution.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to the following Example. In the examples, “parts” and “%” represent “parts by weight” and “% by weight”, respectively.
[Measurement of molar extinction coefficient of photopolymerization initiator]
0.01 g of the photopolymerization initiator was dissolved in 100 mL of acetonitrile and filled in a quartz cell having an optical path length of 1 cm. By measuring the intensity of the incident light and the intensity of the transmitted light using a spectrophotometer, the molar extinction coefficient ε of the photopolymerization initiator in the wavelength range of 330 to 400 nm was determined based on Lambert-Beer's law. Next, ε (λ1) at a wavelength λ1 where ε is maximum in the wavelength range was determined. Table 1 shows the values of ε (λ1) of the photopolymerization initiators used in Examples and Comparative Examples.

イルガキュア９０７；２−メチル−1−[4−(メチルチオ)フェニル]−２−モルフォリノプロパン−1−オン
イルガキュア３６９；２−ベンジル−２−ジメチルアミノ−１−（４−モルフォリノフェニル）−ブタン−１−オン
イルガキュア１８４；１−ヒドロキシシクロヘキシルフェニルケトン

Irgacure 907; 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-oneylgacure 369; 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl)- Butan-1-oneylgacure 184; 1-hydroxycyclohexyl phenyl ketone

Example 1
・ (A1); Irgacure 369 (manufactured by Ciba-Geigy) 0.60 part ・ (a2); Irgacure 184 (manufactured by Ciba-Geigy) 0.50 part [adjustment of red photosensitive coloring composition]
The above photopolymerization initiator was charged with 3.02 parts of a red pigment “CI Pigment Red 254”, 2.51 parts of a yellow pigment “CI Pigment Yellow 150”, an acrylic resin (a copolymer of benzyl acrylate and methacrylic acid, benzyl acrylate and methacrylic acid, The copolymer weight ratio is 60/40, the weight average molecular weight is 31000] 6.00 parts, dipentaerythritol hexaacrylate “Kayarad DPHA” (manufactured by Nippon Kayaku Co., Ltd.), resin type dispersant “Disperbyk-161” (Big Chemie) (Mixed) 0.02 part and 80 parts of the solvent “cyclohexanone” were mixed to obtain a red photosensitive coloring composition.

[Adjustment of green photosensitive coloring composition]
The above photopolymerization initiator includes 3.02 parts of a green pigment “CI Pigment Green 36”, 2.05 parts of a yellow pigment “CI Pigment Yellow 150”, an acrylic resin [a copolymer of benzyl acrylate and methacrylic acid, benzyl acrylate and methacrylic acid, The copolymer weight ratio is 60/40, the weight average molecular weight is 31000] 5.00 parts, dipentaerythritol hexaacrylate “Kayarad DPHA” (manufactured by Nippon Kayaku Co., Ltd.), resin type dispersant “Disperbyk-174” (Bic Chemie) 0.08 part of a product) and 80 parts of a solvent “cyclohexanone” were mixed to obtain a green photosensitive coloring composition.
[Adjustment of blue photosensitive coloring composition]
4.68 parts of blue pigment “CI Pigment Blue 15: 6”, acrylic resin [copolymer of benzyl acrylate and methacrylic acid, copolymer weight ratio of benzyl acrylate and methacrylic acid is 60/40 The weight average molecular weight is 31000] 5.00 parts, dipentaerythritol hexaacrylate “Kayarad DPHA” (manufactured by Nippon Kayaku Co., Ltd.) 3.00 parts, resin type dispersant “Disperbyk-165” (manufactured by BYK Chemie) 0.03 parts, and solvent “cyclohexanone” And mixed with 80 parts to obtain a blue photosensitive coloring composition.

(Comparative Example 1)
Except having changed the photoinitiator into the following, it carried out similarly to Example 1, and obtained the photosensitive coloring composition of red, green, and blue.
・ (A1); Irgacure 907 (Ciba Geigy) 0.90 parts

(Comparative Example 2)
Except having changed the photoinitiator into the following, it carried out similarly to Example 1, and obtained the photosensitive coloring composition of red, green, and blue.
・ (A2); Irgacure 184 (Ciba Geigy) 0.90 parts

[Patterning of photosensitive coloring composition]
On a glass substrate (Corning 1737), the photosensitive coloring compositions obtained in Examples and Comparative Examples were applied by a spin coater, dried in an oven at 70 ° C. for 20 minutes, and a coating film having a thickness of 2.6 μm. After forming the photosensitive coloring composition by ultraviolet rays with an illuminance of 22 mW / cm ² using an ultra high pressure mercury lamp `` USH-2004MB '' (manufactured by USHIO INC) through a photomask having a total light shielding part and a total transmission part. The coating was exposed for 13 seconds. This substrate was spray-developed with a 2% aqueous sodium carbonate solution to remove the unexposed portions, and then washed with ion-exchanged water, and the film thickness (t1) of the developed coating film was measured.
After a dry coating film of the photosensitive coloring composition is formed by the same method, the photosensitive coloring composition is applied with ultraviolet rays having an illuminance of 12 mW / cm ² using an ultrahigh pressure mercury lamp “USH-2004MB” (USHIO INC). The film was exposed for 13 seconds. This substrate was spray-developed with a 2% aqueous sodium carbonate solution to remove unexposed portions, and then washed with ion-exchanged water, and the film thickness (t2) of the developed coating film was measured. The value of t2 / t1 was calculated from the values of t1 and t2. The results are shown in Table 2.

[Preparation of color filter]
A black matrix was patterned on a glass substrate, and the red photosensitive coloring compositions obtained in Examples and Comparative Examples were applied on the substrate with a spin coater. The coating film is passed through a halftone mask [photomask having a total light-shielding part, a semi-light-shielding part (optical density is 50% of the optical density of the total light-shielding part), and a total transmission part] “USH- 2004MB "(USHIO INC Co.) was 13 exposed with ultraviolet illuminance 22 mW / cm ² using. Next, spray development was performed with a developer composed of a 2% aqueous sodium carbonate solution to remove the unexposed portion, and then the substrate was washed with ion-exchanged water. The substrate was heated at 230 ° C. for 20 minutes to form a red pixel. After patterning the green photosensitive coloring compositions obtained in the examples and comparative examples by the same method and arranging the green pixels next to the red pixels, the blue photosensitive coloring compositions obtained in the examples and comparative examples The color filter was manufactured by arranging the blue pixel between the red pixel and the green pixel by patterning.
In the color filter, the thickness (Ct1) of the colored layer for the light transmission region formed by exposure at the full transmission portion of the halftone mask and the halftone mask formed by exposure at the half light shielding portion. The value of Ct2 / Ct1 was calculated from the thickness (Ct2) of the colored layer for the light reflection region. The results are shown in Table 2.

[Visibility evaluation of liquid crystal display]
The visibility of each of the transmissive display and the reflective display was evaluated by a liquid crystal display device using the produced color filter. The results are shown in Table 2.

  From Table 2, when the photosensitive coloring composition of the photopolymerization initiator composition of Example 1 was used, 0.05 ≦ t2 / t1 ≦ 0.75 and 0.05 ≦ Ct2 / Ct1 ≦ 0.75 were obtained, and the visibility of the liquid crystal display device was good. As a result, a color filter exhibiting an excellent color display was obtained. On the other hand, when the photosensitive coloring composition of the photopolymerization initiator composition of Comparative Example 1 was used, the thickness of the colored layer for the light reflection region was large and the reflection color display of the liquid crystal display device was dark. Further, when the photosensitive coloring composition of the photopolymerization initiator composition of Comparative Example 2 was used, the thickness of the colored layer for the light reflecting region was small, and the colored layer for the light reflecting region was peeled off during the development process. .

Claims (3)

A photosensitive coloring composition comprising a photopolymerization initiator, an ethylenically unsaturated monomer, an alkali-soluble resin, and a colorant,
The photopolymerization initiator has an ethyl 4--4- molar extinction coefficient of 8000 L / mol · cm or more and 60000 L / mol · cm or less in an acetonitrile solution at a wavelength where the molar extinction coefficient is maximum at a wavelength of 300 to 450 nm. Dimethylaminobenzoate, 2-ethylhexyl-4-dimethylaminobenzoate, 1,2-octadion-1- [4- (phenylthio)-, 2- (O-benzoyloxime)], 2-methyl-1- [4- ( Photopolymerization initiator selected from the group consisting of (methylthio) phenyl] -2-morpholinopropan-1-one and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one ( and a1), the molar extinction coefficient at wavelength at which the molar extinction coefficient of the maximum in the wavelength range, Ru der below 5000 L / mol · cm in acetonitrile solution 1 - hydroxycyclohexyl phenyl ketone 2-hydroxy-2-methyl-1-phenyl - and a photopolymerization initiator selected from the group consisting of propan-1-one (a2),
The dried coating film of the photosensitive coloring composition is exposed to ultraviolet light with an illuminance of 22 mW / cm ² using an ultrahigh pressure mercury lamp through a photomask having a light shielding part and an opening, and then the unexposed part is alkali-developed. The thickness of the coating film after development with the solution is set to t1, and the dried coating film is exposed to ultraviolet rays with an illuminance of 12 mW / cm ² for 13 seconds using an ultrahigh pressure mercury lamp, and then the unexposed portion is developed with an alkaline developer. A photosensitive coloring composition, wherein t2 / t1 is 0.05 or more and 0.75 or less, where t2 is the thickness of the coating film after being applied. A light-transmitting region colored layer formed using the photosensitive coloring composition according to claim 1 and the light-transmitting region-forming layer formed using the same photosensitive coloring composition as the photosensitive coloring composition. A transflective liquid crystal display device having a pixel comprising a colored layer for a light reflecting region having a thickness of 5 to 75% with respect to the thickness of the colored layer, and having a light transmitting region and a light reflecting region in one pixel Color filter used for It corresponds to the step of applying and drying the photosensitive coloring composition according to claim 1 on a transparent substrate, and the formation of a total light-shielding region and a colored layer for a light-reflecting region, the optical density of which is optical in the whole light-shielding region. A transflective liquid crystal display comprising a step of irradiating and developing ultraviolet rays through a photomask having a semi-light-shielding region lower than the density and a full-transmissive region corresponding to the formation of the colored layer for the light transmissive region. A method for producing a color filter for an apparatus.