JP4736692B2 - Photosensitive red coloring composition, color filter substrate using the same, and transflective liquid crystal display device - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a photosensitive red coloring composition suitable for use as a color filter material, a color filter substrate using the same, and a liquid crystal display device including the color filter substrate. Since a hole can be formed, the present invention relates to a liquid crystal display device with higher definition that can be obtained.

  A transflective liquid crystal display device (semi-transmissive LCD) has a transmissive display part that transmits light from the light emitting device from a backlight or the like in a relatively dark place where there is little outside light, such as indoors, and the outside, such as outdoors. In a place where light can be obtained, it is a system with a reflective display unit that reflects external light by a reflector provided on the array side and is widely used as a display device for mobile devices that are often used outdoors. .

  As shown in FIG. 1, the liquid crystal cell of the transflective LCD has a structure in which a liquid crystal 7 is sandwiched between a color filter substrate 4 and a substrate (array substrate) 8 on which pixel electrodes and circuits for driving the liquid crystal are formed. In the color filter substrate, a plurality of colored pixel layers 3 are formed on the substrate. The colored pixel layer 3 is for coloring light passing through the layer into a predetermined color, and is generally obtained by dispersing a colorant such as a color pigment in a transparent resin (hereinafter referred to as a colored pixel layer). (Referred to as RGB material layer).

  The transflective LCD color filter substrate has an RGB material layer for a transmissive display portion and an RGB material layer for a reflective display portion in one pixel. In the reflective display unit that reflects and displays the external light incident on the transmissive LCD, the external light incident from the color filter display surface passes through the RGB material layer constituting the color filter substrate twice. There have been problems such as the pixel display of the display section becoming dark and the color purity of the transmissive display section not matching.

As a method for solving the above problem, for example, the following methods have been proposed in the prior art.
That is, as shown in FIG. 1, the RGB material layer is simultaneously formed on the transmissive display unit 12 and the reflective display unit 11 using the same coloring material, but the through hole 13 ( This is a method of forming an RGB material layer having a high transmittance by patterning a penetrating region where no RGB material layer is provided. As the shape of the through hole 13 in the RGB material layer, a circular pattern or a stripe pattern that is relatively easy to manage the dimensions is widely used. By forming the through hole, the color characteristics of the RGB material layer It is a method of adjusting.

Next, a method for manufacturing the color filter substrate for the through-hole type transflective LCD will be described.
FIG. 2 is a manufacturing process diagram showing an example of a manufacturing method of a color filter substrate for through-hole type transflective LCD. First, a glass substrate 2 for a color filter made of a predetermined material and provided with a metal thin film (for a light shielding film) 19 on the entire surface on one side is put into the process.

(A) First, a light shielding film 15 having a predetermined pattern is formed on the glass substrate. That is, first, a photosensitive resist resin is applied on the metal thin film 19 to form a resist layer. Using a light-shielding film photomask having a light-shielding film pattern prepared in advance, a predetermined light source is irradiated and exposed, and a predetermined development process is performed, whereby the resist layer is formed into a resist layer 20 patterned for the light-shielding film.
Next, the exposed metal thin film portion is etched using the patterned resist layer 20 as a mask to form a pattern of the light shielding film 15 (see FIG. 2C). Here, each opening between the light shielding films 15 becomes one pixel.

(Ii) A first color RGB material layer is formed in the pixel. That is, a colored material of the first color, for example, an R material resist in which an R (red) color pigment is dispersed in a photosensitive resin is applied to the entire surface of the glass substrate on which the light shielding film is formed by a predetermined method. A coating layer of R material resist is formed on the entire surface.
Using an R material layer photomask provided with an R material layer pattern prepared in advance, the coating layer is irradiated with a predetermined light source, and the R material layer pattern is transferred to the coating layer, followed by a predetermined development process. Then, a patterned R (red) material layer 16 is formed (see FIG. 2E). The R material layer photomask includes an R material layer pattern. The R material layer pattern includes a pixel pattern of a reflective display unit and a pixel pattern of a transmissive display unit each having a predetermined through-hole pattern.

(C) Next, an RGB material layer of the second color is formed. That is, a second color material, for example, a G material resist in which a G (green) color pigment is dispersed in a photosensitive resin, is applied to the entire surface of the glass substrate on which the R (red) material layer is formed by a predetermined method. Coating is performed to form a coating layer of a G material resist on the entire surface of the glass substrate.
Using a G material layer photomask having a reflective display pixel pattern having a G material layer through-hole pattern and a transmissive display portion pixel pattern prepared in advance, the coating layer is irradiated with a predetermined light source and exposed to light. After transferring the G material layer pattern to the layer, a predetermined development process is performed to form a patterned G material layer 17 (see FIG. 2F). The G material layer is formed in a pixel adjacent to the R material layer.

(E) Next, the step of forming the RGB material layer of the third color is performed by the step of forming a color material of the third color on the entire surface of the glass substrate on which the G material layer is formed, for example, a B (blue) color pigment in a photosensitive resin. The B material resist in which is dispersed is applied by a predetermined method, and a coating layer of the B material resist is formed on the entire surface of the glass substrate.
Using a B material layer photomask having a pixel pattern of a reflective display portion and a pixel pattern of a transmissive display portion, which is prepared in advance with a through hole pattern for a B material layer, a predetermined light source is irradiated and exposed to the coating layer, After transferring the B material layer pattern to the coating layer, a predetermined development process is performed to form a patterned B material layer 18 (see FIG. 2G).

  The B material layer 18 is formed in a pixel between the R material layer 16 and the G material layer 17. As described above, the RGB material layer 3 arranged in the order of the R material layer 16, the G material layer 17, and the B material layer 18 is formed.

A through hole 13 is formed in the reflective display portion 11 of the RGB material layer 3. FIG. 3 is a cross-sectional view in the direction perpendicular to the plane of the drawing, taken along the line ZZ in FIG.
As shown in FIG. 3, a through hole 13 is formed in the reflective display portion 11 of the R material layer 16 formed on the glass substrate 2.
The R material layer photomask used to form the R material layer 16 includes an R material layer pattern composed of a pixel pattern of a reflective display portion and a pixel pattern of a transmissive display portion having a through-hole pattern. This is a through hole 13 formed corresponding to the through hole pattern of the reflective display portion.

  (O) Next, the optical path difference adjusting layer 6 made of a transparent resin layer is formed on the reflective display portion 11 of the RGB material layer 3, and the transparent electrode layer 5 is further formed on the entire surface of the glass substrate on which the optical path difference adjusting layer is formed. To obtain a through-hole type transflective LCD color filter substrate (see FIG. 1).

As described above, a photolithographic method is generally used as a method for manufacturing a color filter substrate for a through-hole type transflective LCD. Proximity aligner is used from the viewpoint of production throughput and initial cost of manufacturing equipment. In most cases, the RGB material layer is formed by the proximity exposure method.
That is, the quartz mask provided with the metal film pattern serving as the light shielding layer in advance and the glass substrate were brought close to each other at intervals of several tens to several hundreds of μm, and UV was irradiated through the quartz mask to be applied to the glass substrate. Photocuring of the photosensitive composition (material resist) is performed.

  While the proximity exposure method has advantages such as higher production throughput and lower initial cost of manufacturing equipment, it has the effect of UV light diffraction and the gap between the quartz mask and the color filter substrate. Therefore, the conventional photosensitive composition has a problem that it is difficult to form a fine through hole having a diameter of 10 μm or less.

  Transflective LCDs are widely used as display devices for mobile devices such as mobile phones and digital still cameras. However, in recent years, as the display devices have become higher in definition, the reflective display of the color filter substrate for transflective LCDs It is also necessary to increase the definition of the through-hole pattern of the part. For example, when the resolution of a conventional 2.4-inch mobile phone with QVGA (320 × 240 pixels) is VGA (640 × 480 pixels), the width of one pixel of the RGB material layer Is reduced from about 75 μm to about 25 μm. Therefore, the through-hole pattern formed in a pixel having a width of 25 μm needs to be smaller.

  Recently, in addition to the proximity exposure method, an exposure device for manufacturing color filters of the same size projection method using mirror projection or lens condensing has been put into practical use, and a pattern can be formed without being influenced by diffraction or gap amount. It has become possible to form.

  In the proximity exposure method, exposure is performed by shifting the relative position of the exposure mask having a mask pattern larger than the resolution limit and the substrate coated with the negative photosensitive coloring composition, so that the resolution is less than the resolution limit. A method of forming a narrow opening has been proposed (Patent Document 1).

  When these exposure apparatuses require special functions, there are problems such as an increase in the initial cost of the exposure apparatus and a decrease in production throughput compared to the normal proximity exposure method, which does not lead to cost reduction of the color filter substrate. There are many.

  A major factor affecting the resolution of the photosensitive composition (material resist) is the exposure sensitivity curve γ. That is, as shown in FIG. 4, in the exposure sensitivity curve in which the common logarithm of the irradiated exposure dose is plotted on the horizontal axis and the normalized developed film thickness is plotted on the development residual film ratio (%), the sensitivity is plotted. Assuming that the rising angle of the curve is θ, γ is defined as tan θ, and it is known that the larger this value, the greater the contrast between the exposed and unexposed areas and the better the resolution (non-patent literature). 1 and 2). (See FIG. 4).

However, in a fine pattern that cannot be resolved unless the curing by UV diffracted light is completely inhibited, the resolution is not sufficient if the contrast is large, and this factor alone cannot be solved. .
JP 2005-107356 A Ishikawa et al., “Latest Polymer Materials and Technology Overview”, Tech Publishing, 37 (1988) Taniguchi et al., “Organic Electronics Materials”, Science Forum, 15 (1986)

  The present invention has been made in view of the above circumstances, and is a pattern having good exposure sensitivity and developability, good pattern shape, substrate adhesion, chemical resistance, and heat resistance, and excellent resolution. It is an object of the present invention to provide a photosensitive red coloring composition capable of forming a color filter substrate, a color filter substrate using the same, and a transflective liquid crystal display device. As a result, it is possible to provide a high-definition color filter substrate having a reflective display portion having a through hole of 10 μm or less, and a transflective liquid crystal display device.

The present invention is a photosensitive red coloring composition comprising at least a photopolymerizable monomer, a non-photosensitive resin and / or a photosensitive resin, a dispersant, a polymerization initiator, a polymerization inhibitor, a pigment, and a solvent. The coating film of the photosensitive red coloring composition has an exposure sensitivity curve γ (contrast) of 1.5 or more, and the photosensitive coloring composition is a 1.25% sodium carbonate solution with a film thickness of 2 μm after drying. And a photosensitive red coloring composition having exposure sensitivity characteristics having no sensitivity at an exposure dose of 30% or less of the minimum exposure dose at which the residual film ratio after development under shower development conditions is 90% or more ,
From 48.5 parts of pigment dispersion, 11.5 parts of acrylic varnish, 7.1 parts of photopolymerizable monomer, 4.4 parts of photopolymerization initiator, 16.5 parts of cyclohexanone, and 11.9 parts of propylene glycol monomethyl ethyl acetate The photosensitive red coloring composition characterized by adding hydroquinone 1% anone solution in the range of 0.2 part to 1.0 part to the red coloring composition.

  Moreover, this invention is a photosensitive red coloring composition by the said invention, At least 1 or more types of oxime ester type | system | group polymerization initiators are contained as said polymerization initiator, It is a photosensitive red coloring composition characterized by the above-mentioned.

Moreover, this invention comprises the R (red) material layer formed using the photosensitive red coloring composition of Claim 1 or Claim 2 , It is a color filter substrate characterized by the above-mentioned.

The present invention also provides a transflective liquid crystal display device comprising the color filter substrate according to claim 3 .

  The present invention is a photosensitive red coloring composition comprising at least a photopolymerizable monomer, a non-photosensitive resin and / or a photosensitive resin, a dispersant, a polymerization initiator, a polymerization inhibitor, a pigment, and a solvent. The coating film of the red coloring composition has no sensitivity at an exposure amount of 30% or less of the minimum exposure amount at which γ (contrast) of the exposure sensitivity curve is 1.5 or more and the residual film ratio after development is 90% or more. Since it has exposure sensitivity characteristics, exposure sensitivity and developability are good, pattern shape, substrate adhesion, chemical resistance, heat resistance are all good, and photosensitivity that can form a pattern with excellent resolution. It becomes a red coloring composition. As a result, it is possible to provide a high-definition color filter substrate having a reflective display portion having a through hole of 10 μm or less, and a transflective liquid crystal display device.

Hereinafter, embodiments of the present invention will be described in detail.
The photosensitive red coloring composition of the present invention comprises at least a photopolymerizable monomer, a non-photosensitive resin and / or a photosensitive resin, a dispersant, a polymerization initiator, a polymerization inhibitor, a pigment, and a solvent. As a result of intensive studies, the present inventors have found that the above problems can be solved by using a specific amount of a polymerization inhibitor and a specific polymerization initiator, and have completed the present invention.

(Photopolymerizable monomer)
The photopolymerizable monomer is a monomer whose polymerization is induced by radicals. In the present invention, the photopolymerizable monomer is obtained by reacting a (meth) acrylate having a hydroxyl group with a polyfunctional isocyanate (meth). A polyfunctional urethane acrylate having an acryloyl group is used. The combination of the (meth) acrylate having a hydroxyl group and the polyfunctional isocyanate is arbitrary and is not particularly limited. Moreover, one type of polyfunctional urethane acrylate may be used alone, or two or more types may be used in combination.

  Here, as the (meth) acrylate having a hydroxyl group, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tri (meth) acrylate, ditrimethylol Propane tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol ethylene oxide modified penta (meth) acrylate, dipentaerythritol propylene oxide modified penta (meth) acrylate, dipentaerythritol caprocalactone modified penta (meth) ) Acrylate, glycerol acrylate methacrylate, glycerol dimethacrylate, 2-hydroxy-3-acryloylpropyl methacrylate, epoxy group-containing compound Carboxy (meth) reaction product of acrylate, hydroxyl group-containing polyol polyacrylate, and the like. Examples of the polyfunctional isocyanate include tolylene diisocyanate, hexamethylene diisocyanate, diphenylmethylene diisocyanate, isophorone diisocyanate, and polyisocyanate.

  Further, in the photosensitive red coloring composition of the present invention, from the viewpoint of its stability, developability, and tackiness after being applied on a substrate and dried, the content of the photopolymerizable monomer is determined by the photosensitive red coloring composition. It is preferable that it is 20 weight% or less with respect to 100 weight% of a thing. Further, from the viewpoints of exposure sensitivity, resolution of the resulting pattern, and solvent resistance, the content of the photopolymerizable monomer is preferably 1% by mass or more.

(Non-photosensitive resin and / or photosensitive resin)
In the photosensitive red coloring composition of the present invention, a non-photosensitive resin and / or a photosensitive resin is blended. At present, from the viewpoint of environmental problems, organic solvents are hardly used as a developer, and alkali development has become the mainstream, but when employing alkali development, it is preferable to include an alkali-soluble non-photosensitive resin. . Here, the alkali-soluble non-photosensitive resin means a resin that is soluble in an alkaline aqueous solution and does not have radical crosslinkability. For example, an acidic functional group such as a carboxyl group or a sulfone group. And a resin having a mass average molecular weight of 1,000 to 500,000, preferably 5,000 to 100,000.

  Specifically, acrylic resin, α-olefin / (anhydrous) maleic acid copolymer, styrene / (anhydrous) maleic acid copolymer, styrene / styrene sulfonic acid copolymer, ethylene / (meth) acrylic acid copolymer And isobutylene / (anhydrous) maleic acid copolymer. Among these, at least one resin selected from acrylic resins, α-olefin / (anhydrous) maleic acid copolymers, and styrene / styrene sulfonic acid copolymers is preferable. Among these, acrylic resins are preferably used because of their high heat resistance and transparency.

Further, the photosensitive resin suitable for use in the photosensitive red coloring composition of the present invention means a resin having radical crosslinkability, and is a mass average having at least one ethylenically unsaturated double bond. A resin having a molecular weight of 5,000 to 100,000 is preferably used.
Specifically, a linear polymer having a reactive functional group such as a hydroxyl group, a carboxyl group, or an amino group has a (meth) acryl having an isocyanate group, an aldehyde group, an epoxy group, or the like that can react with the reactive functional group. Examples thereof include resins in which an ethylenically unsaturated double bond is introduced into the linear polymer by reacting a compound, cinnamic acid, or the like.

  In addition, a linear polymer having a reactive functional group such as an isocyanate group, an aldehyde group, or an epoxy group has a (meth) acrylic compound having a hydroxyl group, a carboxyl group, an amino group, or the like that can react with the reactive functional group. Examples thereof include a resin obtained by reacting an acid or the like and introducing an ethylenically unsaturated double bond into the linear polymer. In addition, (meth) acrylic compounds having a linear polymer containing acid anhydrides such as styrene-maleic anhydride copolymer and α-olefin-maleic anhydride copolymer, and having a hydroxyl group such as hydroxyalkyl (meth) acrylate A half-esterified product is also used.

(Pigment)
Although content of a pigment is not specifically limited, It is preferable that it is about 1 to 20 weight% with respect to 100 weight% of a photosensitive red coloring composition. In addition, the main pigments are Red, Orange, and Yellow, and Green, Blue, and Violet can be included as complementary colors. Specific examples of organic pigments are shown by color index (CI) numbers below.

PigmentRed: <C. I> 1, 2, 3, 4, 5, 6, 7, 9, 10, 14, 17, 22, 23, 31, 38, 41, 48: 1, 48: 2, 48: 3, 48: 4 49, 49: 1, 49: 2, 52: 1, 52: 2, 53: 1, 57: 1, 60: 1, 63: 1, 66, 67, 81: 1, 81: 3, 81: x, 83, 88, 90, 97, 112, 119, 122, 123, 144, 146, 149, 166, 168, 169, 170, 171, 172, 175, 176, 177, 178, 179, 180, 184, 185 187,188,190,192,200,202,206,207,208,209,210,215,216,217,220,223,224,226,227,228,240,246,254,255,264 272, 279
Pigment Orange: <C. I> 2, 5, 13, 16, 17: 1, 31, 34, 36, 38, 43, 46, 48, 49, 51, 52, 55, 59, 60, 61, 62, 64, 71, 73
Pigment Yellow: <C. I> 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 20, 24, 31, 32, 34, 35, 35: 1, 36, 36: 1, 37, 37: 1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 86, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123, 125, 126, 127, 128, 129, 137, 138, 139, 144, 146,147,148,150,151,152,153,154,155,156,161,162,164,166,167,168,169,170,171,172,173,174,175,1 6,177,179,180,181,182,185,187,188,193,194,199,213,214
PigmentGreen: <C. I> 1,1: x, 2,2: x, 4, 7, 10, 36, 37 PigmentBlue: <C. I> 1, 1: 2, 1: x, 9: x, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 5, 15: 6, 16, 22, 24, 24: x, 56, 60, 61, 62, 80
PigmentViolet: <C. I> 1, 1: x, 3, 3: 3, 3: x, 5: 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, 50
In combination with the organic pigment, an inorganic pigment may be used in combination in order to ensure good coatability, sensitivity, developability and the like while balancing saturation and lightness. Inorganic pigments include yellow lead, zinc yellow, red bean (red iron oxide (III)), cadmium red, ultramarine, bitumen, chromium oxide green, cobalt green and other metal oxide powders, metal sulfide powders, metal powders, etc. Can be mentioned. Furthermore, for color matching, a dye can be contained within a range that does not lower the heat resistance.

(Dispersant)
When the pigment is contained, it is necessary to contain a dispersant for dispersing the pigment. As the dispersant, a surfactant, an intermediate of pigment, an intermediate of dye, Solsperse, or the like is used. The addition amount of the dispersant is not particularly limited, but is preferably 1 to 10% by weight with respect to 100% by weight of the pigment.

(Polymerization initiator)
As a polymerization initiator suitable for use in the photosensitive red coloring composition of the present invention, 1,2-octanedione, 1- [4-] is preferable in that high γ (contrast) is easily obtained in the exposure sensitivity curve at the time of exposure. (Phenylthio)-, 2- (O-benzoyloxime)], O- (acetyl) -N- (1-phenyl-2-oxo-2- (4′-methoxy-naphthyl) ethylidene) hydroxylamine and other oxime esters Compound. In addition, the following can also be used in combination. 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2- Acetophenone compounds such as benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzyldimethyl ketal Benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyldiphenylsal Benzophenone compounds such as fido, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, thioxanthone compounds such as 2,4-diisopropylthioxanthone, 2,4,6-trichloro-s -Triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-tolyl) ) -4,6-bis (trichloromethyl) -s-triazine, 2-pienyl-4,6-bis (trichloromethyl) -s-triazine, 2,4-bis (trichloromethyl) -6-styryl s-triazine 2- (naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-meth Cynaphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, 2,4-trichloromethyl (4'-methoxystyryl) ) -6-triazine and other triazine compounds,) bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and other phosphine compounds, 9,10-phenance Examples include quinone compounds such as lenquinone, camphorquinone, and ethylanthraquinone, borate compounds, carbazole compounds, imidazole compounds, and titanocene compounds.
These can be used singly or in combination of two or more. The amount of the photopolymerization initiator used is preferably 0.5 to 50% by weight, more preferably 3 to 30% by weight, based on the total solid content of the colored composition.

(Photosensitizer)
Moreover, it is preferable to use together a polymerization initiator and a photosensitizer. As photosensitizers, α-acyloxime esters, acylphosphine oxides, methylphenylglyoxylate, benzyl, 9,10-phenanthrenequinone, camphorquinone, ethylanthraquinone, 4,4′-diethylisophthalo Phenone, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, triethanolamine, methyldiethanolamine, triisopropanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, Isoamyl 4-dimethylaminobenzoate, 2-dimethylaminoethyl benzoate, 2-ethylhexyl 4-dimethylaminobenzoate, N, N-dimethylparatoluidine, 4,4′-bis (dimethylamino) benzophenone, 4,4 ′ -Bis (diethylamino) benzofe An amine compound such as non-4,4′-bis (ethylmethylamino) benzophenone can also be used in combination. These sensitizers can be used alone or in combination. The amount of the sensitizer used is preferably 0.5 to 60% by weight, more preferably 3 to 40% by weight based on the total amount of the photopolymerization initiator and the sensitizer.

A suitable polymerization inhibitor using the photosensitive red coloring composition of the present invention is hydroquinone. The hydroquinone-based polymerization inhibitor is excellent in compatibility with the photosensitive coloring composition and the alkaline developer, and can improve the resolution without reducing the exposure sensitivity during exposure.
In addition, hydroquinone type compounds such as methoquinone can be used, but combinations with pyrogallol, tert-butylcatechol, cuprous chloride, and 2,6-di-tert-butyl-p-cresol are also possible. The amount of the polymerization inhibitor used is preferably 0.001 to 0.050% by weight with respect to 100% by weight of the photosensitive red coloring composition. If it is 0.001% by weight or less, the effect of adding a polymerization inhibitor is insufficient, and if it exceeds 0.050% by weight, the sensitivity is lowered, which is an adverse effect.

  Furthermore, the multifunctional thiol which functions as a chain transfer agent can be contained in the photosensitive red coloring composition. The polyfunctional thiol may be a compound having two or more thiol groups. For example, hexanedithiol, decanedithiol, 1,4-butanediol bisthiopropionate, 1,4-butanediol bisthioglycolate, ethylene Glycol bisthioglycolate, ethylene glycol bisthiopropionate, trimethylolpropane tristhioglycolate, trimethylolpropane tristhiopropionate, trimethylolpropane tris (3-mercaptobutyrate), pentaerythritol tetrakisthioglycolate, Pentaerythritol tetrakisthiopropionate, tris (2-hydroxyethyl) isocyanurate trimercaptopropionate, 1,4-dimethylmercaptobenzene, 2,4,6-trimercapto-s-to Azine, 2- (N, N- dibutylamino) -4,6-dimercapto -s- triazine. These polyfunctional thiols can be used alone or in combination.

  The amount of the polyfunctional thiol used is preferably 0.1 to 30% by weight, more preferably 1 to 20% by weight, based on the total solid content of the photosensitive red coloring composition. If it is less than 0.1% by weight, the effect of adding a polyfunctional thiol is insufficient, and if it exceeds 30% by weight, the sensitivity is too high and the resolution is lowered.

(solvent)
The photosensitive red coloring composition of the present invention is blended with a solvent such as water or an organic solvent in order to enable uniform coating on the substrate. Further, when the photosensitive red coloring composition of the present invention is used for the RGB material layer or the light shielding film of the color filter substrate, the solvent also has a function of uniformly dispersing the pigment. Suitable organic solvents to be used include cyclohexanone, ethyl cellosolve acetate, butyl cellosolve acetate, 1-methoxy-2-propyl acetate, diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, ethylbenzene, ethylene glycol diethyl ether, xylene, ethyl cellosolve, methyl- nAmyl ketone, propylene glycol monomethyl ether toluene, methyl ethyl ketone, ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone, petroleum solvent, etc., depending on the monomer composition, type of polymerization initiator used, etc. Use alone or in combination.

[Method for preparing photosensitive red coloring composition]
The photosensitive red coloring composition of the present invention can be prepared by a known method. For example, the photosensitive red coloring composition of the present invention comprising a photopolymerizable monomer, a photosensitive resin, a dispersant, a polymerization initiator, a polymerization inhibitor, a pigment, and a solvent can be prepared by the following method.

  (1) A pigment composition prepared by mixing a pigment and a dispersant in advance is added to a photopolymerizable monomer and / or photosensitive resin, or a solution in which these are dissolved in a solvent, and dispersed, and the remaining components are added. To do. (2) A pigment and a dispersant are separately added and dispersed in a photopolymerizable monomer and / or photosensitive resin, or a solution in which these are dissolved in a solvent, and then the remaining components are added. (3) A pigment is dispersed in a photopolymerizable monomer and / or a photosensitive resin, or a solution in which these are dissolved in a solvent, a dispersant is added, and the remaining components are added. (4) Prepare two types of photopolymerizable monomer and / or photosensitive resin, or a solution in which these are dissolved in a solvent, disperse the pigment and the dispersant separately in advance, and then mix the remaining components. Added. One of the pigment and the dispersant may be dispersed only in the solvent.

  Here, the dispersion of the pigment or dispersant in the photopolymerizable monomer and / or photosensitive resin, or a solution in which these are dissolved in a solvent, is a three roll mill, a two roll mill, a sand mill, a kneader, a dissolver, a high speed mixer, It can be carried out using various dispersing devices such as a homomixer and an attritor. Moreover, in order to perform dispersion | distribution favorably, you may add and distribute various surfactants. In addition, when preparing a pigment composition by previously mixing a pigment and a dispersant, the powder pigment and the powder dispersant may be simply mixed, but (a) a kneader, a roll, an attritor, a super mill, etc. Mix mechanically with various pulverizers, (b) Disperse the pigment in the solvent, add a solution containing the dispersant, and adsorb the dispersant on the pigment surface. (C) Strong dissolving power such as sulfuric acid It is preferable to employ a mixing method in which the pigment and the dispersant are co-dissolved in the solvent that is held and then co-precipitated using a poor solvent such as water.

  By adopting the above configuration, the present inventor forms a pattern having good exposure sensitivity and developability, good pattern shape, substrate adhesion, chemical resistance and heat resistance, and excellent resolution. It has been found that a photosensitive red coloring composition that can be obtained can be obtained, thereby providing a high-definition transflective liquid crystal display device having a reflective display portion having a through hole of 10 μm or less.

[Color filter substrate]
The color filter substrate comprises a plurality of RGB material layers having different colors arranged in a predetermined pattern on the substrate and a light shielding film for shielding light between adjacent RGB material layers. In some cases, an overcoat layer for protecting these may be formed. Further, in a color filter substrate for a liquid crystal display device, columnar protrusions (photo spacers) for making the cell gap uniform on the light shielding film and / or the RGB material layer, and a raised layer for forming a step in the cell gap May be formed.

  Hereinafter, a method for forming an RGB material layer using the photosensitive red coloring composition of the present invention will be described. First, the photosensitive red coloring composition of the present invention is uniformly applied on a substrate by a spray coating method, a spin coating method, a roll coating or the like and dried. The layer formed in this step is referred to as “photosensitive composition layer”. As the substrate to be used, a transparent substrate is preferable, and specifically, a resin substrate such as a glass plate, polycarbonate, polymethyl methacrylate, polyethylene phthalate, or the like is preferably used.

  Next, the formed photosensitive composition layer is patterned by photolithography. That is, exposure is performed by irradiating active energy rays such as ultraviolet rays and electron beams through a photomask having a predetermined pattern, and then development is performed using a developer such as an organic solvent or an alkaline aqueous solution. Here, in the exposure step, the photopolymerizable monomer in the portion irradiated with the active energy ray is polymerized and cured. Further, when a photosensitive resin is contained, the resin is also crosslinked and cured.

  In order to improve exposure sensitivity, after forming a photosensitive composition layer, a solution of water-soluble or alkaline water-soluble resin (for example, polyvinyl alcohol, water-soluble acrylic resin, etc.) is applied and dried. Exposure may be performed after forming a film that suppresses polymerization inhibition. Then, in the development process, the portion not irradiated with the active energy ray is washed away with the developer. As the developer, an alkaline developer such as an aqueous solution such as sodium carbonate or caustic soda, or an organic alkali solution such as dimethylbenzylamine or triethanolamine is mainly used.

  Moreover, as a developing solution, what added the antifoamer and surfactant was used as needed. Finally, by baking, a light shielding film made of an RGB material layer on the substrate, a columnar projection for making the cell gap of the liquid crystal display device uniform, and a raised layer for forming a step in the cell gap can be formed. it can.

  Next, examples and comparative examples of the present invention will be specifically described, but the present invention is not limited to these examples without departing from the spirit of the present invention. In the examples and comparative examples, “parts” means “parts by weight”.

<Example 1>
[Preparation of photosensitive red coloring composition]
The photosensitive red coloring composition used for preparation of a color filter substrate was prepared in the following manner.
(Preparation of pigment dispersion (pigment composition))
The mixture having the following composition was stirred and mixed uniformly, then dispersed with an Eiger mill (“Mini Model M-250MKII” manufactured by Eiger Japan) for 2 hours using zirconia beads having a diameter of 1 mm, filtered through a 5 μm filter, and pigmented. A dispersion was prepared.
・ Diketopyrrolopyrrole pigment (CI Pigment Red254)
("IRGAZIN DPP RED BO" manufactured by Ciba Specialty Chemicals): 12.0 parts-Photosensitive transparent resin solution: 9.9 parts-Non-photosensitive transparent resin solution: 30.1 parts-Cyclohexanone: 48.0 parts ( Preparation of photosensitive red coloring composition)
Next, the mixture having the following composition was stirred and mixed so as to be uniform, and then filtered through a 1 μm filter to obtain a red colored composition having photosensitivity.
-Pigment dispersion: 48.5 parts-Acrylic varnish: 11.5 parts-Photopolymerizable monomer ("UT-606" manufactured by Osaka Organic Chemical Co., Ltd.): 7.1 parts-Photopolymerization initiator (Ciba Specialty) "Irg907" manufactured by Chemicals Co., Ltd.): 2.7 parts, photopolymerization initiator ("Irg379" manufactured by Ciba Specialty Chemicals Co., Ltd.): 1.7 parts, cyclohexanone: 16.5 parts, propylene glycol monomethyl ethyl acetate: 11. 9 copies

Then, 0.2 parts of hydroquinone 1% anone solution was added to the red coloring composition having photosensitivity and stirred to obtain the photosensitive red coloring composition of the present invention.

<Example 2>
Except for the addition amount of hydroquinone 1% anone solution being 0.5 parts, the same as in Example 1,
A photosensitive red coloring composition of the present invention was obtained.

<Example 3>
A mixture having the following composition was stirred and mixed so as to be uniform, and then filtered through a 1 μm filter to obtain a red colored composition having photosensitivity.
-Pigment dispersion: 48.5 parts-Acrylic varnish: 11.5 parts-Photopolymerizable monomer ("UT-606" manufactured by Osaka Organic Chemical Co., Ltd.): 7.1 parts-Photopolymerization initiator (Ciba Specialty) "Irg379" manufactured by Chemicals): 4.4 parts, cyclohexanone: 16.5 parts, propylene glycol monomethyl ethyl acetate: 11.9 parts

Thereafter, 0.8 part of a 1% anhydroquinone hydroquinone solution was added to the photosensitive red coloring composition and stirred to obtain a photosensitive red coloring composition of the present invention.

<Example 4>
A mixture having the following composition was stirred and mixed so as to be uniform, and then filtered through a 1 μm filter to obtain a red colored composition having photosensitivity.
-Pigment dispersion: 48.5 parts-Acrylic varnish: 11.5 parts-Photopolymerizable monomer ("UT-606" manufactured by Osaka Organic Chemical Co., Ltd.): 7.1 parts-Photopolymerization initiator (Ciba Specialty) "CGI242" manufactured by Chemicals): 4.4 parts, cyclohexanone: 16.5 parts, propylene glycol monomethyl ethyl acetate: 11.9 parts

A photosensitive red coloring composition of the present invention was obtained in the same manner as in Example 1 except that the amount of hydroquinone 1% anone solution added was 1.0 part.

<Example 5>
A photosensitive red coloring composition of the present invention was obtained in the same manner as in Example 1 except that the addition amount of the 1% methoquinone solution was 0.5 parts.

<Comparative Example 1>
A photosensitive red coloring composition of the present invention was obtained in the same manner as in Example 1 except that the hydroquinone 1% anone solution and the methoquinone 1% anone solution were not added.

<Comparative example 2>
A mixture having the following composition was stirred and mixed so as to be uniform, and then filtered through a 1 μm filter to obtain a red colored composition having photosensitivity.
-Pigment dispersion: 48.5 parts-Acrylic varnish: 11.5 parts-Photopolymerizable monomer ("UT-606" manufactured by Osaka Organic Chemical Co., Ltd.): 14.2 parts-Photopolymerization initiator (Ciba Specialty) Chemicals "CGI242"): 8.8 parts, cyclohexanone: 11.0 parts, propylene glycol monomethyl ethyl acetate: 6.0 parts (sensitivity evaluation)
Each photosensitive red coloring composition prepared in each example and comparative example was evaluated as follows. First, the obtained photosensitive red coloring composition was applied on a glass substrate by a spin coating method and then dried to form a photosensitive composition layer having a thickness of 2.0 μm. Next, after pre-baking at 70 ° C. for 20 minutes, ultraviolet exposure was performed through a mask having a 50 μm fine line pattern. Exposure amount was 9 levels of ^{10mJ / cm 2 ~300mJ / cm 2} .
Next, shower development was performed using a 1.25% by mass sodium carbonate solution, followed by washing with water to complete patterning. When the film thickness of the obtained filter segment (R (red) material layer) was set to 1 for the unexposed / undeveloped portion, the remaining film ratio after exposure / development at each exposure level was calculated. From the obtained remaining film rate curve, the exposure amount at the beginning of rising of the remaining film rate curve was defined as the rising exposure amount, and the minimum exposure amount at which the remaining film rate reached 90% or more was defined as the saturated exposure amount.

Further, the contrast (γ) and the sensitivity cut rate were obtained by the following equations.

Γ (contrast) of exposure sensitivity curve
= 0.90 / (Log ₁₀ (saturated exposure) -Log ₁₀ (rising exposure))

Sensitivity cut rate = rise exposure / saturation exposure

(Patternability evaluation)
Using a mask with an octagonal through-hole pattern of 6 to 20 μm, UV exposure is performed at an exposure amount of 100 mJ / cm ² , and development time with an alkaline developer is used to wash away the unexposed portions of each resist and coating film. Except for the appropriate time, after the substrate was fabricated in the same manner as the substrate fabrication in the sensitivity evaluation, heat treatment was performed at 230 ° C. for 60 minutes, and the through-holes obtained there were (1) through-hole width, (2) Evaluation was made by the cross-sectional shape of the through hole.

  About (1), it carried out using the optical microscope. The evaluation results are shown in Table 1. As for the evaluation rank, a case where a through-hole width equal to or larger than the pattern width was obtained with respect to the through-hole pattern on the mask and there was no color residue inside the through-hole was evaluated as ◯, and other cases were evaluated as x. (2) was evaluated using a scanning electron microscope (SEM). The rank of the evaluation was ◯: a forward tapered shape or a non-tapered shape, and X: an inverted tapered shape. The obtained results are shown in Table 1.

（結果）
表１に示すように、重合禁止剤としてハイドロキノンもしくはメトキノンの１％アノン溶液を添加して得られる感光性赤色着色組成物を調製した実施例１〜５では、感光性赤色着色組成物の露光感度曲線のγ（コントラスト）が１．５以上で、且つ現像後残膜率が９０％以上となる最小露光量の３０％以下の露光量での感度のない露光感度特性を有する感光性赤色着色組成物を得ることができ、パターンの形状は良好で、１０μｍ以下のホール幅を形成することが確認できた。
これに対して、ハイドロキノン系重合禁止剤を添加していない比較例１、比較例２では、感度、断面形状の特性は良好だが、γが１．５以上で、且つ現像後残膜率が９０％以上となる最小露光量の３０％以下の露光量での感度のない露光感度特性を有する赤色着色組成物は得られなかった。

(result)
As shown in Table 1, in Examples 1 to 5 in which photosensitive red colored compositions obtained by adding 1% anone solution of hydroquinone or methoquinone as a polymerization inhibitor were prepared, the exposure sensitivity of the photosensitive red colored composition Photosensitive red coloring composition having an insensitive sensitivity characteristic at an exposure amount of 30% or less of the minimum exposure amount in which γ (contrast) of the curve is 1.5 or more and a residual film ratio after development is 90% or more It was confirmed that the pattern shape was good and a hole width of 10 μm or less was formed.
In contrast, Comparative Example 1 and Comparative Example 2 to which no hydroquinone-based polymerization inhibitor was added had good sensitivity and cross-sectional shape characteristics, but γ was 1.5 or more and the residual film ratio after development was 90. A red coloring composition having an exposure sensitivity characteristic having no sensitivity at an exposure dose of 30% or less of the minimum exposure dose of at least% was not obtained.

  As described in the above examples, by adding a hydroquinone polymerization inhibitor, and by using a specific initiator, the exposure sensitivity and developability are good, and the pattern shape, substrate adhesion, chemical resistance, and heat resistance are good. It was confirmed that both patterns were good and excellent in resolution.

It is sectional drawing of an example of the liquid crystal cell of transflective LCD. It is a manufacturing process figure which shows an example of the manufacturing method of the color filter substrate for through-hole type transflective LCDs. It is sectional drawing of the paper surface perpendicular direction in the ZZ line of FIG.2 (g). It is explanatory drawing of the exposure sensitivity curve of a photosensitive composition (material resist).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 9 ... Polarizing plate 2 ... Glass substrate 3 ... RGB material layer 4 ... Color filter substrate 5 ... Transparent electrode layer 6 ... Optical path difference adjusting layer 7 ... Liquid crystal 8 ..Substrates with pixel electrodes or circuits (array substrates)
DESCRIPTION OF SYMBOLS 10 ... Back light 11 ... Reflection display part 12 ... Transmission display part 13 ... Through hole 15 ... Light shielding film 16 ... R (red) material layer 17 ... G material layer 18 ... B material layer 19 ... Metal thin film 20 ... Patterned resist layer 21 ... Reflector

Claims (4)

A photosensitive red coloring composition comprising at least a photopolymerizable monomer, a non-photosensitive resin and / or a photosensitive resin, a dispersant, a polymerization initiator, a polymerization inhibitor, a pigment, and a solvent, wherein the photosensitive red coloring composition The coating film of the product has an exposure sensitivity curve γ (contrast) of 1.5 or more, and the photosensitive coloring composition is subjected to shower development conditions with a 1.25% sodium carbonate solution having a film thickness of 2 μm after drying. minimum with the exposure amount of 30% or less of the exposure amount is a photosensitive red-colored composition having no exposure sensitivity characteristic sensitivity, pigment dispersion 48.5 parts after development residual film ratio of 90% or more in, Red colored group consisting of 11.5 parts of acrylic varnish, 7.1 parts of photopolymerizable monomer, 4.4 parts of photopolymerization initiator, 16.5 parts of cyclohexanone, and 11.9 parts of propylene glycol monomethyl ethyl acetate A photosensitive red coloring composition , wherein a hydroquinone 1% anone solution is added to the composition within a range of 0.2 part to 1.0 part .   The photosensitive red coloring composition according to claim 1, wherein the polymerization initiator contains at least one oxime ester polymerization initiator. A color filter substrate, characterized by comprising a photosensitive red coloring composition was formed using the R (red) material layer according to claim 1 or claim 2. A transflective liquid crystal display device comprising the color filter substrate according to claim 3 .

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