JP2006189890A - Colored picture forming material for color filter, method of manufacturing colored picture forming material for color filter and color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color filter having improved transmittance, in other words heightened brightness, achieving low electric power consumption, besides not lowering chroma and permitting reproduction of sharp color tone. <P>SOLUTION: In a colored picture forming material for the color filter which contains a binder resin (a), an ethylenic compound (b), a photo-polymerization initiating system (c), a solvent (d) and a red pigment (e), and (f) on the coloring material for the color filter other rhan at least one or more sorts of red, di-pentaerythritol hexa(metha)acrylate is used as the ethyenic compound (b), propylene glycol monomethly ether acetate is used as the solvent (d) and a color of C.I. (color index) PR254 is used as the red pigment (e). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a colored image forming material for a color filter used for a liquid crystal color display or the like, specifically, a colored image forming material for a color filter for a red pixel, a method for producing a colored image forming material for a color filter, and a color Regarding filters.

  In order to reduce the power consumption of a transmissive display element such as a liquid crystal color display, it is effective to improve the light utilization efficiency of the backlight. One of the means is to increase the transmittance of the color filter. Conceivable. However, when the transmittance of the color filter is increased over the entire wavelength, the saturation of the display color is lowered, so that it is difficult to achieve both improved transmittance and clear color tone reproducibility. When the saturation is low, there is a problem that the chromaticity range of colors that can be displayed is narrowed, which is not practical and a color filter that satisfies both is not found.

  An object of the present invention is to provide a color filter that can improve the transmittance, that is, increase the brightness, achieve low power consumption, and can reproduce a clear color tone without reducing the saturation.

In order to solve the above problems, the present invention provides (a) a binder resin, (b) an ethylenic compound, (c) a photopolymerization initiation system, (d) a solvent, (e) a red pigment, and (f) at least In a colored image forming material for a color filter containing one or more dyes other than red, (b) dipentaerythritol hexa (meth) acrylate is used as the ethylenic compound, and (d) propylene glycol monomethyl ether acetate is used as the solvent. (E) As a red pigment, C.I. I. (Color Index) A colored image forming material for a color filter characterized by using PR254 is provided.
In addition, the present invention is applied to a transparent substrate by spin coating to a thickness of 1 to 2 μm, dried at 70 ° C. for 3 minutes, cured by irradiation with 100 mj / cm ² , patterned with an alkali developer, and subjected to a high-pressure mercury lamp. The colored image forming material for a color filter, wherein the transmittance of a red pixel formed by irradiating an ultraviolet ray of 5000 mj / cm ² by heat treatment at 200 ° C. for 10 minutes is 10% or less at 560 nm and 80% or more at 600 nm (E) a red pigment, and (f) at least one pigment other than red is mixed with (g) a dispersant and (d) a part of the solvent, and subjected to a dispersion treatment to obtain an ink. A color dispersion comprising: (b) an ethylenic compound, (c) a photopolymerization initiation system, and (d) the remainder of the solvent are added and mixed to make a uniform mixture. A method for producing a colored image forming material for a router is provided.
The present invention also provides a color filter having red, green and blue pixels on a substrate, wherein the red pixels are formed of the colored image forming material for color filters. .

  According to the present invention, there is provided a color filter that can improve the transmittance, that is, increase the brightness, achieve low power consumption, and can reproduce a clear color tone without reducing the saturation.

  The inventors have noted that the most important factor that determines the color tone (brightness and saturation) of the red pixel is the transmittance curve of the red pigment used. That is, if the ratio of the transmittance at 560 nm and 600 nm is as large as possible and the rise of the transmittance curve between them is as steep as possible, the transmittance of the red pixel by the material using such a dye is also a steep curve. Therefore, it is based on the knowledge that it is possible to realize a color filter that improves the lightness but does not decrease the saturation.

  The greatest feature of the present invention is that when the transmittance of the red pigment as a colored transmission film is 10% at 560 nm as the pigment for the red pixel of the color filter, it is 40% or more at 580 nm and 80 at 600 nm. % Pigment or more. That is, when a colored permeable membrane containing only a red pigment is formed as a pigment and the pigment concentration and film thickness are adjusted so that the transmittance at 560 nm is 10%, the transmittance of the colored permeable membrane is measured. In this case, it means that a dye that is 40% or more at 580 nm and 80% or more at 600 nm is used. When forming such a colored permeable membrane for transmittance measurement, the composition other than the dye, such as resin and photopolymerization initiator, is the same type used when forming pixels such as actual color filters. And amounts are preferably used. In other words, since the concentration of the dye is different, the required amount of the dispersant is changed, and other colors are not mixed, and the mixture is mixed in the same material and quantity ratio as the actual pixel image forming material. It is preferable to form a film.

  The transmittance is more preferably 50% or more at 580 nm and 85% or more at 600 nm. The dye may be either a dye or a pigment. However, since the pigment is applicable to a method for producing a color filter by a known pigment dispersion method, such a pigment is suitable. I. (Color index) PR254 and PR209 are used.

  In addition, the red pixel of the present invention usually contains at least one kind of dye other than the above-mentioned specific red dye, which is used for the purpose of adjusting chromaticity and is a dye suitable for such purpose. Any pigment may be used, but a pigment is preferable for the same reason as described above, and orange, yellow, and other pigments are generally used. I. PO71, PY181, PY139 etc. are mentioned.

  The colored image forming material for a color filter of the present invention usually contains at least a red pigment as described above, at least one pigment other than red and a resin. The resin is not particularly limited, and any known resin can be used as the color filter forming resin. Examples thereof include acrylic resins, styrene resins, polyimide resins, and polyamide resins.

  More specifically, it is preferable that the photopolymerizable composition containing a binder resin, an ethylenic compound, and a photopolymerization initiation system contains the specific red dye as described above and at least one dye other than red. is there. Examples of the binder resin include the resins exemplified above, and these may have a photosensitive group in this structure.

  The ethylenic compound may be an ethylenic compound in which polymerization is induced by the above photopolymerization initiation system. For example, a polyfunctional (meta) compound such as dipentaerythritol hexa (meth) acrylate or trimethylolpropane tri (meth) acrylate may be used. ) Acrylate and bisphenol derivatives can be used ("(meth) acrylate" means "acrylate or methacrylate"). Moreover, two or more of these ethylenic compounds can be used in combination as required.

  Examples of the photopolymerization initiation system include titanocene, biimidazole, benzothiazole, benzophenone, thioxanthone, benzotriazole, and salicylate ultraviolet absorbers, which may be used in combination as necessary. You can also. Preferable examples include titanocene and biimidazole, more preferably those using these in combination. Moreover, a photopolymerization accelerator can also be used together as needed. Examples of photopolymerization accelerators include KAYACURE EPA manufactured by Nippon Kayaku Co., Ltd., and benzoic acid derivatives such as KAYACURE DMBI.

  When the colored image forming material for a color filter of the present invention contains a photopolymerizable composition, the blending ratio is usually 5 to 100 parts by weight of the ethylenic compound and 0 in the photopolymerization initiation system with respect to 100 parts by weight of the binder resin. Used in the range of 0.01 to 30 parts. Further, the blending ratio of the red pigment of the present invention and other pigments is not particularly limited as long as the desired transmittance curve can be achieved. Usually, the red pigment is a colored image for the color filter of the present invention. 20 to 40% by weight based on the total solid content of the forming material, and pigments other than red are used at 5 to 20% by weight based on the total solid content.

  In addition, when using a pigment as a coloring matter, it is preferable to use a dispersant. In this case, the dispersant is effective if it is effective for pigment dispersion, such as a surfactant, a low molecular dispersant, and a polymer dispersant. Either is fine. Examples of the surfactant include an anionic surfactant. Examples of the low molecular weight dispersant include Solsperse series manufactured by Zeneca Co., Ltd. and Disperbyk series manufactured by Big Chemie. As the polymer dispersant, either a thermosetting resin or a thermoplastic resin can be used.

  Further, the color filter of the present invention is a color filter having red, green, and blue pixels on a substrate, wherein the red pixels are formed using the color image forming material for color filters, The red pixel has a transmittance of 10% or less at 560 nm and 80% or more at 600 nm. As the transparent substrate, various glass plates, plastic sheets such as polyester such as polyethylene terephthalate, and polyolefin such as polypropylene and polyethylene can be used.

  Examples of a method for producing a color filter using the color image forming material for a color filter of the present invention include conventionally known pigment dispersion methods, dye dispersion methods, electrodeposition methods, and dyeing methods. When manufacturing a color filter, the procedure is as follows in the case of a pigment dispersion method using a photopolymerizable resin. First, the pigment is mixed with a dispersant and a part of the solvent, and after sufficiently dispersing to prepare an ink-like dispersion, an ethylenic compound, a photopolymerization initiator and the remainder of the solvent are added to the dispersion and mixed. Thus, a uniform color resist solution is obtained. Next, it is applied onto a substrate using a coating method such as a spin coat method, and after drying, the necessary portion is irradiated with light using a mask, developed and dried, and subjected to heat treatment and ultraviolet treatment to thereby apply the one color. Form a filter. By repeating this process for the other two colors, a color filter is obtained.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited at all by the following examples.
Examples and Comparative Examples First, 10.0 g of the red pigment described below was mixed, 13.3 g of BYK-161 manufactured by BYK-Chemie Co., Ltd. as a dispersant, and 35.7 g of propylene glycol monomethyl ether acetate as a solvent were mixed. 180 g of glass beads with a diameter of 0.5 mm were added and shaken for 5 hours with a paint conditioner to obtain a red dispersion. A yellow dispersion liquid for adjusting chromaticity was obtained by the same method.

As a clear resist, 4.0 g of an acrylic resin having a repeating unit represented by the following formula (1) as a binder, 4.0 g of dipentaerythritol hexaacrylate as an ethylenic compound, and 2- (2 as a photopolymerization initiator -Chlorophenyl) -4,5-diphenylimidazole dimer 0.4 g, 4,4'-bis (diethylamino) benzophenone 0.2 g, 2-methylbenzothiazole 0.4 g, propylene glycol monomethyl ether acetate 34. 5 g was mixed and stirred uniformly.

The above pigment dispersion and clear resist were stirred and mixed, and then filtered to obtain a uniform color resist. This is coated on a transparent substrate to a thickness of 1 to 2 μm by spin coating, dried on a hot plate at 70 ° C. for 3 minutes, and then cured by irradiating 100 mj / cm ² with ultraviolet light using a photomask, and an alkali developer. Then, patterning was performed. Subsequently, ultraviolet rays of 5000 mj / cm ² were irradiated with a high pressure mercury lamp, and further heat-treated in an oven at 200 ° C. for 10 minutes to produce a color filter.

  In Examples and Comparative Examples, color filters were prepared using the following pigments.

Example 1
As a red pigment, C.I. I. 5.0g of ink using PR254 ("Chromophthal DPP Red BP" manufactured by Ciba Geigy Co., Ltd.), 1.2g of ink using yellow pigment PY139 ("Paliotol 1841D" manufactured by BASF) for adjusting chromaticity, and clear resist A color filter prepared with a color resist prepared by mixing 18.3 g with a film thickness of 1.0 μm.
(Example 2)
10.0 g of ink using PR209 (“HOSTAPERM Red EG TRANS” manufactured by Hoechst Industry Co., Ltd.) as a red pigment, 0.3 g of ink using yellow pigment PY139 (same as above) for adjusting chromaticity, and clear resist 9 A color filter prepared to a thickness of 2.0 μm with a color resist prepared by mixing 4 g.
(Comparative Example 1)
5.0 g of ink using PR177 (“Chromophthal Red A2B” manufactured by Ciba Geigy) as a red pigment, 1.1 g of ink using yellow pigment PY139 (same as above) for adjusting the chromaticity, and clear resist 14 A color filter prepared with a color resist prepared by mixing 3 g with a thickness of 1.5 μm.

  The lightness and saturation were evaluated and compared for the red pixel of each color filter created. Table 1 shows the transmittance at each wavelength of the colored transmission film formed using the red pigment used in Examples and Comparative Examples, and the chromaticity and brightness of the red pixel of the actually produced color filter. Here, the transmittance of the colored permeable membrane formed using the red pigment is 2.0 g of the red pigment dispersion and 4.8 g of the clear resist, and each is individually color-registered by the method described above, A sample having a film thickness of 1 to 2 μm on a transparent substrate was prepared and measured.

実施例１、２および比較例１のカラーフィルターの透過率曲線をそれぞれ図１、２、３に示す。実施例１のカラーフィルターの透過率曲線からは、５６０ｎｍで２％、６００ｎｍで９５％の透過率を有し、また比較例１と同様な色度でありながら大幅に明度が向上していることがわかる。実施例２についても同様に５６０ｎｍで９％６００ｎｍで８５％の透過率を有し、また大幅な明度向上が達成されている。

The transmittance curves of the color filters of Examples 1 and 2 and Comparative Example 1 are shown in FIGS. From the transmittance curve of the color filter of Example 1, it has a transmittance of 2% at 560 nm and 95% at 600 nm, and the brightness is greatly improved while having the same chromaticity as Comparative Example 1. I understand. Similarly, Example 2 also has a transmittance of 9% at 560 nm and a transmittance of 85% at 600 nm, and a significant improvement in brightness is achieved.

  On the other hand, in Comparative Example 1, the transmittance is 560 nm, 7%, 600 nm, and 76%, and the lightness is not comparable to that of the example. The above results show that there is a slight difference in effect depending on the type of complementary color pigment for adjusting chromaticity, and it is desirable that the transmittance curve of the complementary color pigment is as close as possible to that of the red pigment. For example, by changing the complementary color pigment from PY139 to PO71 (“DPP Orange TR” manufactured by Ciba Geigy), the Y value can be further improved by about 1 as compared with the above-described embodiment.

  Further, the above example is a result when the color is adjusted to red with chromaticity (x = 0.55, y = 0.33). However, the effect of the present invention is not limited to the above case, and the chromaticity range (x ≧ 0.51, The same applies to the red color reproduction of y ≦ 0.36).

  According to the present invention, it is possible to provide a color filter that can improve the transmittance, that is, increase the brightness, achieve low power consumption, and can reproduce a clear color tone without reducing the saturation. Therefore, industrial applicability is very high in the field of colored image forming materials for color filters and color filters.

FIG. 4 is a diagram illustrating a transmittance curve of a red pixel by the color filter according to the first embodiment. FIG. 10 is a diagram illustrating a transmittance curve of a red pixel by the color filter according to the second embodiment. FIG. 6 is a diagram showing a transmittance curve of red pixels by the color filter of Comparative Example 1;

Claims (7)

  (A) binder resin, (b) ethylenic compound, (c) photopolymerization initiation system, (d) solvent, (e) red pigment, and (f) at least one or more pigments other than red In the colored image forming material, (b) dipentaerythritol hexa (meth) acrylate is used as the ethylenic compound, (d) propylene glycol monomethyl ether acetate is used as the solvent, and (e) red pigment is C.I. I. (Color index) Color image forming material for color filter using PR254.   The colored image forming material for a color filter according to claim 1, wherein the repeating molecular unit contains at least one group containing a nitroxyl or hydroxylamino group or a side containing a nitroxyl or hydroxylamino group. (E) a red dye, and (f) at least a condensation polymer or addition polymer substituted by a chain group, or a copolymer thereof with other homogenous compounds or components containing no nitroxyl or hydroxylamine A colored image forming material for a color filter, characterized in that a pigment containing 0.01 to 100% by weight based on a pigment contained in one or more pigments other than red is excluded.   The amount of (b) ethylenic compound used in the range of 5 to 100 parts by weight and (c) the photopolymerization initiation system in the range of 0.01 to 30 parts relative to 100 parts by weight of the binder resin (1) or 2 The coloring image forming material for color filters as described.   The colored image forming material for a color filter according to any one of claims 1 to 3, further comprising (g) a dispersant. Was coated to a thickness of 1~2μm by spin coating on a transparent substrate, after 3 minutes drying at 70 ℃, 100mj / cm ² irradiated to cure, and patterned with an alkali developer, a high-pressure mercury lamp of 5000 mJ / cm ² The color according to any one of claims 1 to 4, wherein the transmittance of a red pixel formed by irradiating with ultraviolet rays and heat-treating at 200 ° C for 10 minutes is 10% or less at 560 nm and 80% or more at 600 nm. Colored image forming material for filters. 6. A method for producing a colored image forming material for a color filter according to claim 5, further comprising the following steps (1) and (2):
(1) (e) a red pigment, and (f) at least one or more pigments other than red are mixed with (g) a dispersant and a part of (d) a solvent and subjected to a dispersion treatment to form an ink-like dispersion. (2) The step of adding and mixing (b) the ethylenic compound, (c) the photopolymerization initiation system, and (d) the remainder of the solvent to homogenize the mixture 6. A color filter having red, green and blue pixels on a substrate, wherein the red pixels are formed from the colored image forming material for a color filter according to any one of claims 1 to 5. Color filter.

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