JP4736992B2 - Color filter substrate manufacturing method, color filter substrate, and transflective liquid crystal display device - Google Patents

Description

The present invention relates to a method for manufacturing a color filter substrate , a color filter substrate for a liquid crystal display device, and a transflective liquid crystal display device. In particular, a transflective liquid crystal that can display on the screen by transmitted light from a light source built in the liquid crystal display device, and can also reflect on external light such as sunlight or room light and display on the screen by this reflected light. The present invention relates to a display device.

  In general, the color liquid crystal display device is configured by enclosing a liquid crystal 181 between a color filter substrate 310 and an array substrate 320 as shown in FIG. The color filter substrate 310 is configured with the transparent substrate 111 as a structural support, and a polarizing film 171 is laminated on the screen observer side. Further, the opposite side (back side) is divided into a large number of pixel regions, and a light shielding pattern 121 is provided at a portion between pixels located at the boundary between the pixel region and the transparent colored pixels 131R between the light shielding patterns 121. , 131G, 131B are arranged. The transparent colored pixels 131R, 131G, and 131B are for coloring transmitted light for each pixel, and generally three colors of red (R), green (G), and blue (B) corresponding to the three primary colors of light are arranged. Yes. The light shielding pattern 121 prevents color mixing of transmitted light colored in these colors.

  The color filter substrate 310 is provided with an overcoat layer 141 for filling the steps of the transparent colored pixels 131R, 131G, and 131B, and then a transparent electrode 151 and an alignment film (not shown).

  On the other hand, the array substrate 320 is obtained by providing an electrode 161 and an alignment film (not shown) on one surface (liquid crystal side) of the transparent substrate 112 and a polarizing film 171 on the other surface.

  A voltage is applied between the transparent electrode 151 and the electrode 161 for each pixel to control the transmission / non-transmission of light, and the transmitted light is displayed on the screen as display light.

Various methods are known for forming the transparent colored pixels 131R, 131G, and 131B of the color filter substrate 310. Today, the most commonly used method is to use a negative photosensitive coloring composition. In this method, the photosensitive coloring composition is formed by exposure and development by a proximity exposure method using a proximity aligner.
That is, a photosensitive coloring composition is applied to the transparent substrate 111 on which the light shielding pattern 121 is formed to form a colored photosensitive layer, and patterning processing such as pattern exposure and development is performed with a proximity exposure apparatus as many times as necessary (here, three times). By repeating, the transparent colored pixels 131R, 131G, and 131B are formed between the light shielding patterns 121 on the transparent substrate 111.

The liquid crystal display device includes a device that uses light of a light source such as a backlight disposed on the back surface of the array substrate 320 as the display light, and a device that reflects external light such as outdoor light and uses it as display light. Broadly divided.
The former is called a transmissive liquid crystal display device, which can display a bright screen, but requires a built-in light source inside the device, and consumes a large amount of power.
On the other hand, the latter is called a reflective liquid crystal display device, which consumes less power, but it is difficult to obtain a bright display screen indoors where there is little external light.

Based on the above, taking advantage of the transmissive liquid crystal display device and the reflective liquid crystal display device, a bright screen is displayed using the light from the built-in light source as the display light indoors, and outside light is used outdoors. A liquid crystal display device that prevents power consumption has been proposed, and such a device is called a transflective liquid crystal display device.
Such transflective liquid crystal display devices have already been put into practical use as display devices for mobile devices such as mobile phones and digital still cameras.

  However, when the light from the light source is used as the display light, the display light is transmitted once through the transparent colored pixels 131R, 131G, and 131B, whereas the external light is reflected to display the screen as display light. This display light is transmitted twice through the transparent colored pixels 131R, 131G, and 131B. For this reason, when external light is reflected to display the screen as display light, light loss due to the transparent colored pixels 131R, 131G, and 131B increases, resulting in a darker display screen.

  Various methods for improving this and ensuring the brightness of the display screen are known. However, the pixel area is divided into two areas of the reflection part b and the transmission part a, and the reflected light is displayed on the screen as display light. In some cases, the reflection part b is used, and when the light source light is displayed on the screen as the display light, the transmission part a is used. That is, a reflection film is selectively provided on the reflection portion, and external light incident on this portion is used as display light, and light source light is transmitted from the back surface of the transmission portion a and used as display light.

Each transparent colored pixel region of the color filter substrate 310 of such a transflective liquid crystal display device is divided into a transmissive part a and a reflective part b as shown in FIG. 131G will be described.
A through hole 131x is provided in the reflection part b of the transparent green pixel 131G, and the transparent green pixel 131G does not exist in the through hole 131x. For this reason, there is no light loss based on the transparent green pixel 131G in the display light transmitted through the through hole 131x, and a bright display screen can be configured.
The through holes 131x are formed simultaneously with the formation of transparent colored pixels by patterning processing such as pattern exposure and development of the colored photosensitive layer.

  By the way, the display device of the mobile device is also required to have high definition, and it is also necessary to increase the definition of the through hole 131x formed in the colored pixel region. For example, when a 2.4 inch mobile phone has a conventional resolution of QVGA (320 × 240 pixels) but a resolution of VGA (640 × 480 pixels), the pixel width of each transparent colored pixel is about It will be narrowed from 75 μm to about 25 μm. Accordingly, a smaller through-hole formed in a pixel having a width of 25 μm is required, for example, a through-hole having a diameter of 10 μm or less.

  However, when trying to reproduce such a fine pattern shape, when a negative colored photosensitive layer is used, there is a problem that the through hole diameter cannot be accurately reproduced due to a diffraction phenomenon at the time of pattern exposure.

Since the intensity of diffracted light is generally smaller than the intensity of transmitted light (0th order diffracted light), a method of accurately controlling the through-hole diameter using this intensity difference is also conceivable. That is, when the exposure sensitivity curve is plotted with the common logarithm of the exposure amount for the negative colored photosensitive layer as the horizontal axis and the post-development residual film ratio as the vertical axis, the larger the tangent tan θ of the rising angle θ of the exposure sensitivity curve, A method is known in which the contrast between an exposed area and a non-exposed area after development is increased, and thus the resolution is improved (see, for example, Non-Patent Documents 1 and 2).
If this principle is used and exposure is performed with the minimum necessary exposure amount, the negative colored photosensitive layer is sensitive to transmitted light (0th order diffracted light), while it is not sensitive to diffracted light having a lower intensity. . If this is developed, transparent colored pixels having different remaining film ratios can be formed in the exposed area and the non-exposed area, and therefore it is possible to accurately form a through hole having a fine diameter. It is done.
Ishikawa et al .: Tech Publishing, “Latest Polymer Materials and Technology Overview”, 37 (1988) Taniguchi et al .: Science Forum “Organic Electronics Materials”, 15 (1986)

  However, according to the study of the present inventor, it was difficult to accurately form a through hole having a diameter of 10 μm or less by only controlling tan θ as described above. For example, if the sensitivity of the negative colored photosensitive layer is high, and therefore the necessary minimum exposure amount is small, it becomes easy to be sensitive to diffracted light, and therefore it is not possible to accurately form a through hole with a fine diameter. It was difficult.

Accordingly, an object of the present invention is to provide a method for producing a color filter substrate using a photosensitive coloring composition capable of reproducing a fine through hole having a diameter of 10 μm or less.

In addition, another object of the present invention is to provide a color filter substrate and a transflective liquid crystal display device manufactured by using this method for manufacturing a color filter substrate.

The invention according to claim 1 includes the steps of coating, drying, exposing and developing using a photosensitive coloring composition comprising a photopolymerizable monomer, a resin binder, a polymerization initiator, a colorant and a solvent. In the manufacturing method of the color filter substrate that passes,
In the exposure sensitivity curve in which the residual film ratio after development of the photosensitive coloring composition is plotted with the horizontal axis as the common logarithm of the exposure amount and the vertical axis as the residual film ratio after development, the rising angle of this exposure sensitivity curve is defined as θ. Γ (contrast) defined by the tangent of θ is 1.33 or more, and the photosensitive coloring composition has a thickness of 2.0 μm after drying and is 1.25% by mass with a sodium carbonate solution. an exposure amount of 23% or less after development residual film ratio minimum exposure amount becomes 85% or more in the shower development conditions, Ri 0% der developing after the residual film ratio, further said photosensitive coloring composition from hydroquinone And forming a transparent colored pixel having a through hole having a diameter of 6 μm to 10 μm through a process of coating, drying, exposing and developing the photosensitive coloring composition on a transparent substrate. With features That is obtained by the method for manufacturing a color filter substrate.

According to the first aspect of the present invention, since γ is 1.33 or more, the difference in intensity between transmitted light and diffracted light can be reflected sensitively in the remaining film ratio, and the remaining film ratio after development. Since the residual film ratio after development is 0% at an exposure amount of 23% or less of the minimum exposure amount that is 85% or more, curing by diffracted light with low intensity does not occur. For this reason, it is possible to accurately form transparent colored pixels having fine through holes.
On the other hand, if the residual film ratio after development is lower than 85%, a sufficiently stable coating film cannot be obtained depending on the process conditions such as exposure and development.

In order to control the exposure amount at which the γ is 1.33 or more and the post-development residual film ratio is 0%, an appropriate amount of a polymerization inhibitor may be added to the photosensitive coloring composition. Examples of the polymerization inhibitor, hydroquinone can be utilized.

Further, the invention according to claim 2, which has been made from such circumstances, i.e., in which the photosensitive coloring composition according to claim 1 containing a polymerization inhibitor you containing hydroquinone .

Also, an invention according to claim 2, which the photosensitive coloring composition, was a method of manufacturing the color filter substrate of claim 1 wherein the photosensitive coloring composition containing an oxime ester-based polymerization initiator It is.

The invention according to claim 3 is a color filter substrate comprising at least a black matrix, a plurality of transparent colored pixels, an overcoat layer, and a transparent electrode on a transparent substrate, wherein the transparent colored pixels are: The transmission part is divided into a transmission part and a reflection part. The transmission part is an area for coloring the transmitted light from the light source arranged on the back side of the liquid crystal display device, while the reflection part is external light incident from the observer side. The through-hole is provided in the reflection part, and the transparent coloring pixel is produced using the photosensitive coloring composition according to claim 1 or 2. The color filter substrate is characterized by the above.

According to a fourth aspect of the present invention, there is provided a transflective liquid crystal display device produced using the color filter substrate according to the third aspect.

  According to the present invention, the difference in intensity between transmitted light and diffracted light can be reflected sensitively in the residual film ratio, and further, there is no hardening caused by diffracted light having low intensity, so transparent with fine through-holes can be obtained. Colored pixels can be formed with high accuracy. As a result, it is possible to produce a high-resolution, high-definition transflective liquid crystal display device.

Hereinafter, embodiments of the present invention will be described.
The photosensitive coloring composition which concerns on this invention contains a photopolymerizable monomer, a resin binder, a polymerization initiator, a coloring agent, and a solvent as the essential component. In addition, it is desirable to contain a polymerization inhibitor. Moreover, you may contain additives, such as a dispersing agent, a photosensitizer, and a chain transfer agent.

Further, in the photosensitive coloring composition according to the present invention, in the exposure sensitivity curve in which the horizontal axis represents the common logarithm of the exposure amount and the vertical axis represents the residual film ratio after development, the rising angle of this exposure sensitivity curve is defined as θ. In this case, γ (contrast) defined by the tangent of θ needs to be 1.33 or more. This exposure sensitivity curve is obtained by irradiating a colored photosensitive layer obtained by coating a photosensitive coloring composition on a substrate with ultraviolet rays for exposure, developing with a developer, and determining the amount of exposure and the remaining film ratio after development. By plotting, it can be easily determined experimentally.
In addition, the photosensitive coloring composition according to the present invention needs to have a post-development residual film ratio of 0% at an exposure amount of 23% or less of the minimum exposure amount at which the post-development residual film ratio becomes 85% or more. These post-development residual film ratios can be obtained simultaneously with the exposure sensitivity curve.

Incidentally, by adding hydroquinone or it made a polymerization inhibitor, in the gamma (contrast) 1.33 or more, with an exposure amount of 23% or less of the minimum exposure amount is post-development film remaining ratio becomes 85% or more, It is possible to control the exposure amount at which the post-development remaining film ratio becomes 0%.

Next, each component which comprises the photosensitive coloring composition which concerns on this invention is demonstrated.
(Photopolymerizable monomer)
A photopolymerizable monomer is polymerized by irradiation with exposure light, and changes a colored photosensitive layer produced using the photosensitive coloring composition to be insoluble in a developer. Generally, it is a monomer whose polymerization is induced by radicals.

  As such a photopolymerizable monomer, a polyfunctional urethane acrylate obtained by reacting a (meth) acrylate having a hydroxyl group with a polyfunctional isocyanate can be used.

Examples of the (meth) acrylate having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tri (meth) acrylate, ditrimethylolpropane 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 Shi group-containing compound and the 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.

  From the viewpoint of tackiness, developability of the colored photosensitive layer formed using the photosensitive coloring composition of the present invention, and stability of the photosensitive coloring composition, the content of the photopolymerizable monomer is determined by the photosensitive coloring composition. It is preferable that it is 20 weight% or less with respect to 100 weight% of the total amount of a thing. Further, it is preferably 1% by weight or more from the viewpoint of exposure sensitivity, pattern resolution and solvent resistance.

(Resin binder)
The resin binder fixes the colored photosensitive layer formed using the photosensitive coloring composition to the transparent substrate and dissolves in the developer during development. A resin having no photosensitivity may be used, or a resin having photosensitivity may be used.

At present, as the developer, an alkaline developer having a small influence on the environment is often used. For this reason, it is desirable to use an alkali-soluble resin as the resin binder. For example, it is a non-photosensitive resin having an acidic functional group such as a carboxyl group or a sulfone group.
Examples of such non-photosensitive resins include acrylic resins, α-olefin- (anhydrous) maleic acid copolymers, styrene- (anhydrous) maleic acid copolymers, styrene-styrene sulfonic acid copolymers, and ethylene- (meth). An acrylic acid copolymer, an isobutylene- (anhydrous) maleic acid copolymer, etc. are mentioned. An acrylic resin, an α-olefin- (anhydrous) maleic acid copolymer, and a styrene-styrene sulfonic acid copolymer are preferable. Among these, acrylic resins are preferably used because of their high heat resistance and transparency. A resin having a weight average molecular weight of 1,000 to 500,000, preferably 5,000 to 100,000 can be preferably used.

  In addition, as a photosensitive resin, a linear polymer having a reactive functional group is reacted with a (meth) acrylic compound having a substituent capable of reacting with the reactive functional group, cinnamic acid, etc. Examples thereof include a resin in which a double bond is introduced into the linear polymer. In addition, a linear polymer having a substituent capable of reacting with the reactive functional group is reacted with a (meth) acrylic compound having a reactive functional group, cinnamic acid, or the like, to thereby form an ethylenically unsaturated double bond. Resin introduced into the polymer. Examples of the reactive functional group include a hydroxyl group, a carboxyl group, and an amino group, and examples of the substituent capable of reacting with the reactive functional group include an isocyanate group, an aldehyde group, and an epoxy group.

  In addition, a linear polymer containing an acid anhydride such as a styrene-maleic anhydride copolymer or an α-olefin-maleic anhydride copolymer is a (meth) acrylic compound having a hydroxyl group such as hydroxyalkyl (meth) acrylate. Those half-esterified with can be used as the photosensitive resin.

  These photosensitive resins preferably have a weight average molecular weight of 5,000 to 100,000.

(Coloring agent)
The colorant colors the transparent colored pixels and colors display light of the liquid crystal display device.
Although pigments and dyes can be used, it is desirable to use pigments because of their excellent durability. The pigment may be either an organic pigment or an inorganic pigment, but an organic pigment can be preferably used. Moreover, although the compounding quantity is not specifically limited, It is preferable that it is about 1-20 mass% with respect to 100 weight% of total amounts of the photosensitive coloring composition.

  In addition, although the color of a colorant may be arbitrary, when the color of a transparent coloring pixel is blue, the advantage of this invention can fully be utilized. For example, the main pigments are Blue or Violet pigments, and Red, Orange, Green, and Yellow are complementary colors.

Next, specific examples of organic pigments for the colored layer are shown by color index (CI) numbers.
Pigment Blue: <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
Pigment Violet: <C. I> 1, 1: x, 3, 3: 3, 3: x, 5: 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, 50
Pigment Green: <C. I> 1,1: x, 2,2: x, 4,7,10,36,37
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 Red: <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 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
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 pepper (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, it is also possible to add a dye within a range that does not lower the heat resistance.

(Dispersant)
When a pigment is used as the colorant, it is desirable 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. Although the addition amount of a dispersing agent is not specifically limited, It is preferable to set it as 1 to 10 weight% with respect to 100 weight% of compounding quantities of a pigment.

(Polymerization initiator)
The invention according to claim 3 is characterized in that the photosensitive coloring composition contains an oxime ester polymerization initiator.
As the polymerization initiator, an oxime ester polymerization initiator can be preferably used. For example, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], O- (acetyl) -N- (1-phenyl-2-oxo-2- (4 '-Methoxy-naphthyl) ethylidene) hydroxylamine.

  In addition to the oxime ester polymerization initiator, other polymerization initiators can be used in combination. Examples of such polymerization initiators include acetophenone compounds, benzoin compounds, benzophenone compounds, thioxanthone compounds, triazine compounds, phosphine compounds, quinone compounds, borate compounds, carbazole compounds, and imidazole compounds. And titanocene compounds.

  Examples of acetophenone compounds include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, and 1-hydroxy. Examples thereof include cyclohexyl phenyl ketone and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one.

  Examples of benzoin compounds include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzyl dimethyl ketal.

  Examples of the benzophenone compounds include benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and the like.

  Examples of the thioxanthone compound include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone and the like.

  Examples of triazine compounds include 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, and 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-methoxy-naphth-1) -Yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, 2,4-trichloromethyl (4'-me Kishisuchiriru) -6-triazine and the like.

  Examples of the phosphine compound include bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

  Examples of the quinone compound include 9,10-phenanthrenequinone, camphorquinone, and ethylanthraquinone.

The amount of the polymerization 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 photosensitive coloring composition.
(Photosensitizer)
In addition to the polymerization initiator, it is preferable to add a photosensitizer to the photosensitive coloring composition according to the present invention.
An example of the photosensitizer is an amine compound. For example, triethanolamine, methyldiethanolamine, triisopropanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 2-dimethylaminoethyl benzoate, 4-dimethylaminobenzoate 2-ethylhexyl acid, N, N-dimethylparatoluidine, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, 4,4′-bis (ethylmethylamino) benzophenone, etc. is there.

  Α-acyloxime ester, acylphosphine oxide, methylphenylglyoxylate, benzyl, 9,10-phenanthrenequinone, camphorquinone, ethylanthraquinone, 4,4′-diethylisophthalophenone, 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone or the like can also be used as a sensitizer.

  The amount of these sensitizers used is preferably 0.5 to 60% by weight, more preferably 3 to 40% by weight, based on the total amount of photopolymerization initiator and sensitizer.

(Polymerization inhibitor)
The invention according to claim 2 is characterized in that the photosensitive coloring composition contains a polymerization inhibitor represented by the following chemical formula (1). By adding the polymerization inhibitor represented by the chemical formula (1), the γ (contrast) and the residual film ratio after development can be controlled in relation to the exposure amount, and the addition is important.

Examples of the polymerization inhibitor is Haidorokino down.

  In addition to this, pyrogallol, tert-butylcatechol, cuprous chloride, 2,6-di-tert-butyl-p-cresol, and the like can be used in combination.

  The amount of the polymerization inhibitor used is preferably 0.001 to 0.050% by weight based on the total solid content of the photosensitive 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.

(Chain transfer agent)
Moreover, the photosensitive coloring composition which concerns on this invention can be made to contain the polyfunctional thiol which acts as a chain transfer agent. 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, trimercaptopropionic acid tris (2-hydroxyethyl) isocyanurate, 1,4-dimethylmercaptobenzene, 2,4,6-trimercap -s- triazine, 2- (N, N- dibutylamino) -4,6-dimercapto -s- triazine.

  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 colored 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 solvent has a function of optimizing the viscosity of the photosensitive coloring composition and uniformly dispersing the colorant. As the solvent, water, an organic solvent, or the like can be used. As organic solvents, 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-n amyl ketone, propylene Examples include glycol monomethyl ether toluene, methyl ethyl ketone, ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone, and petroleum solvents.

Next, the preparation method of the photosensitive coloring composition of this invention is demonstrated.
The photosensitive coloring composition of the present invention can be prepared by a known method. For example, the photosensitive blue color composition of the present invention comprising a photopolymerizable monomer, a resin binder, a pigment, a dispersant and a solvent can be prepared by any of the following methods (1) to (4).

  (1): A pigment composition prepared by mixing a pigment and a dispersant in advance is added to a solution obtained by dissolving a photopolymerizable monomer and / or resin binder in a solvent, and dispersed, and the remaining components are added. .

  (2): A pigment and a dispersant are separately added and dispersed in a solution in which a photopolymerizable monomer and / or resin binder or both are dissolved in a solvent, and then the remaining components are added.

  (3): After the pigment is dispersed in a solution in which the photopolymerizable monomer and / or resin binder or both are dissolved in a solvent, the pigment dispersant is added, and then the remaining components are added.

  (4): Prepare two types of solutions in which a photopolymerizable monomer or resin binder or both are dissolved in a solvent, disperse the pigment and dispersant separately in advance, then mix them and add the remaining components To do. One of the pigment and the dispersant may be dispersed only in the solvent.

  Here, the pigment and the dispersant can be dispersed using various dispersing devices such as a three-roll mill, a two-roll mill, a sand mill, a kneader, a dissolver, a high speed mixer, a homomixer, and an attritor.

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, or (b) Disperse the pigment in the solvent, then add a solution containing the dispersant to adsorb the dispersant on the pigment surface, or (c) Strongly dissolve sulfuric acid, etc. It is preferable to employ a mixing method in which the pigment and the dispersant are co-dissolved in a powerful solvent and then co-precipitated using a poor solvent such as water.

The invention according to claim 3 is a color filter substrate comprising, on a transparent substrate, at least a black matrix, a plurality of transparent colored pixels produced using the photosensitive coloring composition, an overcoat layer, and a transparent electrode. The transparent colored pixel is divided into a transmissive part and a reflective part, and a through hole is formed in the reflective part.

The method for producing the color filter substrate of the present invention will be described below.
FIG. 1 is a schematic configuration diagram showing an embodiment of a color filter substrate of the present invention. FIG. 2 is a schematic configuration diagram showing an embodiment of the transflective liquid crystal device of the present invention.
3A to 3F are schematic cross-sectional views illustrating an example of a method for manufacturing a color filter substrate of the present invention in the order of steps.
First, a photosensitive black composition in which a black pigment (for example, carbon black) is dispersed in a photosensitive resin is coated on the transparent substrate 11 by a roll coating method or the like to form a black photosensitive layer, and pattern exposure, development, etc. A black matrix 21 is formed at a predetermined position of the transparent substrate 11 by performing a patterning process (see FIG. 3A).
Here, as the transparent substrate 11, a glass substrate can be suitably used, and a resin substrate such as polycarbonate, polymethyl methacrylate, polyethylene phthalate, or the like can also be used.
The black matrix 21 may be a metal thin film pattern such as chromium.

Next, a red pigment (for example, a dianthraquinone pigment), a polymerization initiator (for example, an oxime ester polymerization initiator), a dispersant, and a photosensitizer (for example, an amine group) are added to an acrylic photosensitive resin. Compound), a polymerization inhibitor ( hydroquinone), and a solvent are mixed and dispersed in predetermined amounts to prepare a photosensitive red composition.

Next, the photosensitive red composition is applied on the transparent substrate 11 on which the black matrix 21 is formed by a roll coating method or the like, and prebaked to form a red photosensitive layer 31r (see FIG. 3B).
Here, a spray coating method, a spin coating method, or the like can be used as a coating method.

  Next, a patterning process such as pattern exposure and development is performed on the red photosensitive layer 31r using a photomask, and a transparent layer including a red reflecting portion 31Rb and a red transmitting portion 31Ra in which a through hole 31x is formed between the black matrixes 21 is formed. A red pixel 31R is formed (see FIG. 3C).

For the pattern exposure, a proximity exposure method using a proximity aligner is suitable, and the exposure is performed at an exposure amount at which the remaining film ratio after development is 85% or more.
In this case, the portion corresponding to the light shielding pattern of the photomask, that is, the non-exposed portion is not cured at all and is completely removed by development. In addition, when the residual film ratio after development exceeds the exposure amount of 85% or more, the part corresponding to the light shielding pattern of the photomask, that is, the non-exposed part is slightly exposed by the diffracted light. The part corresponding to the opening of the mask, that is, the exposed part can be sufficiently cured to form a transparent red pixel having a sufficient area.

Prior to pattern exposure, a solution of a water-soluble resin or an alkaline water-soluble resin (for example, polyvinyl alcohol or a water-soluble acrylic resin) may be applied onto the coating film.
By applying these resins, inhibition of polymerization due to oxygen in the atmosphere can be suppressed, and the sensitivity of the red photosensitive layer can be improved.

  Next, as the developer for the development process, an alkali developer such as an alkaline aqueous solution or an organic alkaline solution can be used. Examples of the alkaline aqueous solution include sodium carbonate and caustic soda, and examples of the organic alkaline solution include dimethylbenzylamine and triethanolamine. Moreover, you may use the developing solution to which the antifoamer and surfactant were added as needed.

Next, in substantially the same process as the transparent red pixel 31R, a green pigment (for example, phthalocyanine green pigment), a polymerization initiator (for example, oxime ester polymerization initiator), and a dispersant are added to the acrylic photosensitive resin. A photosensitizer (for example, an amine compound), a polymerization inhibitor ( hydroquinone), and a solvent are mixed and dispersed in predetermined amounts to prepare a photosensitive green composition.

  Next, the photosensitive green composition is applied on the transparent substrate 11 on which the black matrix 21 and the transparent red pixel 31R are formed by a roll coating method or the like, prebaked to form a green photosensitive layer, and a photomask is used. Then, the green photosensitive layer is subjected to patterning processing such as pattern exposure and development to form a transparent green pixel 31G including a green reflecting portion 31Gb and a green transmitting portion 31Ga in which a through hole 31x is formed between the black matrixes 21 (FIG. 3 (d)).

Next, in almost the same process as the transparent red pixel 31R, a blue pigment (for example, phthalocyanine blue pigment), a polymerization initiator (for example, an oxime ester polymerization initiator), and a dispersant are added to the acrylic photosensitive resin. Then, a photosensitizer (for example, an amine compound), a polymerization inhibitor ( hydroquinone), and a solvent are mixed and dispersed in a predetermined amount to prepare a photosensitive blue composition.

  Next, the photosensitive blue composition is applied by a roll coating method or the like on the transparent substrate 11 on which the black matrix 21, the transparent red pixel 31R, and the transparent green pixel 31G are formed, and a blue photosensitive layer is formed by prebaking. Then, the blue photosensitive layer is subjected to patterning processing such as pattern exposure and development using a photomask, and a transparent blue pixel 31B composed of a blue reflecting portion 31Bb and a blue transmitting portion 31Ba in which a through hole 31x is formed between the black matrixes 21. (See FIG. 3E).

  Further, an overcoat layer 41, a transparent electrode 51, and an alignment film (not shown) are formed to obtain the color filter substrate 100 of the present invention (see FIG. 3 (f)).

  The color filter substrate 100 and the array substrate 110 on which the electrode 61 is formed at a predetermined position of the transparent substrate 12 are bonded to form a cell, the liquid crystal 81 is enclosed, and the polarizing film 71 is provided. The transflective liquid crystal display device 200 of the present invention can be obtained (see FIG. 2).

Next, synthesis examples, examples and comparative examples relating to the photosensitive coloring composition of the present invention will be described in detail. In the examples and comparative examples, “parts” represents “parts by weight”.
[Preparation of colored composition]
The photosensitive blue composition used for color filter preparation was prepared in the following ways.
ε-type copper phthalocyanine pigment (CI Pigment Blue 15: 6) 11.0 parts (“Heliogen Blue L-6700F” manufactured by BASF)
1.0 part of a phthalocyanine pigment derivative represented by the following chemical formula (2)

Photosensitive transparent resin solution 9.9 parts Non-photosensitive transparent resin solution 30.1 parts Cyclohexanone 48.0 parts After stirring and mixing the mixture having the above composition uniformly, using a zirconia bead having a diameter of 1 mm, Eiger Mill (Eiger Japan) (Mini Model M-250 MKII)) for 2 hours and then filtered through a 5 μm filter to produce a pigment dispersion (1).

next,
Pigment dispersion (1) 52.0 parts Acrylic varnish 7.0 parts Photopolymerizable monomer ("Aronix M-402" manufactured by Toa Gosei Co., Ltd.) 3.5 parts Oxime ester photopolymerization initiator 1.0 part (Ciba Specialty Chemicals “IrgOXE01”)
Photopolymerization initiator (“Irg379” manufactured by Ciba Specialty Chemicals) 1.0 part sensitizer (“EAB-F” manufactured by Hodogaya Chemical Co., Ltd.) 0.2 part cyclohexanone 21.5 parts propylene glycol monomethyl ether acetate 13. 8 parts The mixture of the above composition was stirred and mixed uniformly, filtered through a 1 μm filter to prepare a photosensitive blue composition (former 1), and 0.5 part of hydroquinone (HQ) 1% anone solution was added. The mixture was stirred to obtain the photosensitive blue composition (1) of the present invention.

  0.8 parts hydroquinone (HQ) 1% anone solution was added to the photosensitive blue composition (original 1) of Example 1 and stirred to obtain the photosensitive blue composition (2) of the present invention.

next,
Pigment dispersion (1) 52.0 parts acrylic varnish 7.0 parts photopolymerizable monomer (“Aronix M-402” manufactured by Toa Gosei Co., Ltd.) 3.5 parts photopolymerization initiator (“Irg379” manufactured by Ciba Specialty Chemicals) "" 2.0 parts sensitizer ("EAB-F" manufactured by Hodogaya Chemical Co., Ltd.) 0.2 parts cyclohexanone 21.5 parts propylene glycol monomethyl ether acetate 13.8 parts Then, the mixture was filtered through a 1 μm filter to prepare a photosensitive blue composition (former 3), 1.0 part of 1% hydroquinone (HQ) anone solution was added and stirred, and the photosensitive blue composition of the present invention ( 3) was obtained.

next,
Pigment dispersion (1) 52.0 parts acrylic varnish 7.0 parts photopolymerizable monomer (“Aronix M-402” manufactured by Toa Gosei Co., Ltd.) 3.5 parts oxime ester photopolymerization initiator 2.0 parts (Ciba Specialty Chemicals “CGI242”)
Sensitizer ("EAB-F" manufactured by Hodogaya Chemical Co., Ltd.) 0.2 parts cyclohexanone 21.5 parts propylene glycol monomethyl ether acetate 13.8 parts The above composition mixture was stirred and mixed uniformly, and a 1 µm filter To produce a photosensitive blue composition (former 4), 1.5 parts of 1% hydroquinone (HQ) anone solution was added and stirred to obtain a photosensitive blue composition (4) of the present invention. .

0.8 parts of a 1% methoquinone (MQ) anone solution was added to the photosensitive blue composition (original 1) of Example 1 and stirred to obtain a photosensitive blue composition (5) of the present invention. This embodiment is a reference embodiment that is not included in the embodiment of the present invention.

1.0 part of 1% methoquinone (MQ) anone solution was added to the photosensitive blue composition (former 1) of Example 1 and stirred to obtain the photosensitive blue composition (6) of the present invention. This embodiment is a reference embodiment that is not included in the embodiment of the present invention.

(Comparative Example 1)
The photosensitive blue composition (Example 1) of Example 1 was used as the photosensitive blue composition (7) of Comparative Example 1.

(Comparative Example 2)
Pigment dispersion (1) 52.0 parts acrylic varnish 7.0 parts photopolymerizable monomer (“Aronix M-402” manufactured by Toa Gosei Co., Ltd.) 7.0 parts photopolymerization initiator (“CGI242” manufactured by Ciba Specialty Chemicals) "] 4.0 parts sensitizer (" EAB-F "manufactured by Hodogaya Chemical Co., Ltd.) 0.2 parts cyclohexanone 18.0 parts propylene glycol monomethyl ether acetate 11.8 parts Stir and mix the mixture of the above composition uniformly And it filtered with a 1 micrometer filter, and obtained the photosensitive blue composition (8) of the comparative example 2.

  About each photosensitive blue composition prepared by each said Example and comparative example, the sensitivity was evaluated as follows.

First, the photosensitive blue compositions (1) to (8) obtained in the above examples and comparative examples were applied on a glass substrate by spin coating and then dried to form a 2.0 μm-thick blue photosensitive layer. did.
Next, after prebaking at 70 ° C. for 20 minutes, UV exposure was performed through a photomask having a 50 μm fine line pattern by a proximity exposure method using a proximity aligner. 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.

The film thickness of the obtained filter segment was divided by the film thickness (2.0 μm) of the unexposed / undeveloped portion to calculate the remaining film ratio. Then, the exposure sensitivity curve was plotted with the horizontal axis representing the common logarithm of the exposure dose and the vertical axis representing the remaining film ratio after development. From the obtained exposure sensitivity curve, the exposure amount at the beginning of the rising of the exposure sensitivity curve is the rising exposure amount, and the minimum exposure amount at which the remaining film ratio reaches 85% or more is the saturated exposure amount. The sensitivity cut rate was calculated.

Γ (contrast) of exposure sensitivity curve = 0.85 / (Log ₁₀ (saturated exposure amount) −Log ₁₀ (rising exposure amount))
Sensitivity cut rate = rise exposure / saturation exposure (patterning evaluation)
About each photosensitive blue composition prepared in each Example and the comparative example, the patterning performance was evaluated as follows.
First, the photosensitive blue compositions (1) to (8) obtained in the above examples and comparative examples were applied by spin coating, pre-baked at 70 ° C. for 20 minutes, and a 2.0 μm-thick blue photosensitive material. A layer was formed.
Next, ultraviolet exposure was performed through a photomask provided with an octagonal hole pattern having a width of 6 to 20 μm in steps of 2 μm by a proximity exposure method using a proximity aligner. The exposure amount is 100 mJ / cm ² .
In Table 1 described later, only the through hole shape having a small diameter of 6 to 10 μm is described.

  Next, shower development was performed using a 1.25% by mass sodium carbonate solution, followed by washing with water to complete patterning. The development time was set to an appropriate time for washing away the unexposed coating film. Next, heat treatment was performed at 230 ° C. for 60 minutes to obtain an evaluation substrate.

  Then, the width of the through hole of the obtained transparent blue pixel was evaluated by (1): the width of the through hole of the transparent blue pixel with respect to the hole width of the photomask, and (2): the cross-sectional shape of the transparent blue pixel through hole.

  About (1), it carried out using the optical microscope. As for the evaluation rank, a case where a through hole having a width equal to or larger than the width of the through hole of the photomask was obtained and there was no color residue inside the through hole portion was evaluated as ◯, and other cases were evaluated as x.

Further, (2) was evaluated using a scanning electron microscope (SEM).
The rank of the evaluation is a forward taper shape in which the pattern end portion is a slope (slope) as shown in FIG. 6A or a non-taper shape in which the pattern end portion is vertically upright as shown in FIG. 6B. The shape was O, and the inverse taper shape as shown in FIG.

  The obtained results are shown in Table 1.

As shown in Table 1, in the photosensitive blue compositions of Examples 1 to 6 obtained by adding 1% anone solution of hydroquinone or methoquinone as a polymerization inhibitor, γ (contrast) of the exposure sensitivity curve of the blue photosensitive layer Was 1.33 or more, and it was confirmed that the post-development residual film ratio was 0% when the exposure quantity was 23% or less of the minimum exposure quantity at which the post-development residual film ratio was 85% or more.
When this condition was satisfied, it was confirmed that the patterning shape was good and a through hole having a diameter of 10 μm or less could be formed with high accuracy.

  On the other hand, in Comparative Example 1 and Comparative Example 2 in which no hydroquinone polymerization inhibitor was added, γ was 1.33 or more, and the minimum exposure amount of 23 at which the residual film ratio after development was 85% or more. When the exposure amount is not more than%, the residual film ratio after development does not become 0%, so it is difficult to form a through hole having a diameter of 10 μm or less.

It is a schematic cross section which shows one Example of the color filter substrate of this invention. It is a schematic cross section which shows one Example of the transflective liquid crystal device of this invention. (A)-(f) is a schematic cross section which shows an example of the manufacturing method of the color filter substrate of this invention in process order. It is a schematic block diagram which shows an example of a transflective liquid crystal device. It is explanatory drawing which shows the structural example of a color filter. It is explanatory drawing which shows an example of pattern shape evaluation.

Explanation of symbols

11, 12, 111, 112 ... transparent substrate 21 ... black matrix 31r ... red photosensitive layer 31R, 131R ... red pixel 31Ra ... red transmission part 31Rb ... red reflection part 31G, 131G ... green pixel 31Ga ... ... Green transmission part 31Gb ... Green reflection part 31B, 131B ... Blue pixel 31Ba ... Blue transmission part 31Bb ... Blue reflection part 31x, 131x ... Through hole 41, 141 ... Overcoat layers 51, 151 ... Transparent Electrodes 61, 161 ... Electrodes 71, 171 ... Polarizing films 81, 181 ... Liquid crystal 100, 310 ... Color filter substrate 110, 320 ... Array substrate 121 ... Light shielding pattern a ... Transmission part b ... Reflection part

Claims (4)

In the method for producing a color filter substrate that undergoes the steps of coating, drying, exposing and developing, using a photosensitive coloring composition comprising a photopolymerizable monomer, a resin binder, a polymerization initiator, a colorant and a solvent ,
In the exposure sensitivity curve in which the residual film ratio after development of the photosensitive coloring composition is plotted with the horizontal axis as the common logarithm of the exposure amount and the vertical axis as the residual film ratio after development, the rising angle of this exposure sensitivity curve is defined as θ. Γ (contrast) defined by the tangent of θ is 1.33 or more, and the photosensitive coloring composition has a thickness of 2.0 μm after drying and is 1.25% by mass with a sodium carbonate solution. an exposure amount of 23% or less after development residual film ratio minimum exposure amount becomes 85% or more in the shower development conditions, Ri 0% der developing after the residual film ratio, further said photosensitive coloring composition from hydroquinone And forming a transparent colored pixel having a through hole having a diameter of 6 μm to 10 μm through a process of coating, drying, exposing and developing the photosensitive coloring composition on a transparent substrate. With features Method of fabricating a color filter substrate of that. The photosensitive colored composition, method of manufacturing a color filter substrate according to claim 1, wherein the photosensitive coloring composition containing an oxime ester-based polymerization initiator. A color filter substrate comprising at least a black matrix, a plurality of transparent colored pixels, an overcoat layer, and a transparent electrode on a transparent substrate, wherein the transparent colored pixels are divided into a transmissive portion and a reflective portion. The transmission part is an area for coloring transmitted light from a light source arranged on the back side of the liquid crystal display device, while the reflection part is an area for reflecting external light incident from the observer side and coloring this reflected light. A through-hole is provided in the reflective portion, and the transparent colored pixel is produced using the method for producing a color filter substrate according to claim 1 or 2 . A transflective liquid crystal display device manufactured using the color filter substrate according to claim 3 .