JP2021051296A - Color filter substrate and electronic paper using the same - Google Patents

Abstract

To provide a color filter substrate which offers good visibility from a short distance and bright and vivid display, and a display device using the color filter substrate.SOLUTION: A color filter substrate for electronic paper is provided, comprising at least red pixels, green pixels, and blue pixels arranged on a substrate, where the length of the minimum repeating unit is in a range of 100 to 160 μm, inclusive.SELECTED DRAWING: None

Description

The present invention relates to color filter substrates and electronic paper.

Liquid crystal display devices are used in various applications such as televisions, notebook computers, personal digital assistants, smartphones, and digital cameras, taking advantage of their characteristics such as light weight, thinness, and low power consumption. The liquid crystal display device is required to have optimum colors of 3 to 6 primary colors depending on the application, and a color filter substrate having various color performances is used.

In recent years, there are increasing opportunities for electronic paper to be used as a display device different from a liquid crystal display device. Electronic paper has the characteristics of low power consumption and is easy on the eyes, and efforts are being made toward colorization. A color ink method and a color filter method are being studied for colorization, but the color filter method is drawing attention from the viewpoint of display switching speed.

Unlike a general liquid crystal display device, electronic paper does not adjust the brightness by backlight light, but uses external light for the display principle, so that there is a problem that the display becomes dark. In the case of colorized electronic paper of the color filter method, there is a problem that the display becomes darker because the pixels of the color filter absorb light. Further, electronic paper using a color filter has a problem of color mixing due to a misalignment between the color filter and the display layer, and there is a demand for a color filter substrate that is excellent in display even if the misalignment occurs.

In order to improve the vividness of the display, an electronic paper excluding the black matrix between pixels has been reported (for example, Patent Document 1). Further, in order to suppress the misalignment of bonding, a method of forming colored pixels on the display layer using an inkjet device has been proposed (for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2003-107234 International Publication No. 2013/0473360

In particular, when electronic paper is used as an electronic book such as an electronic textbook, it is necessary that the display characteristics are excellent and the visibility at a close distance is good. However, no clear design guideline has been given for the pixel size and pixel arrangement of color electronic paper using a color filter substrate. In the case of electronic paper having a color filter substrate without a black matrix as described in Patent Document 1, the pixel size affects the visibility and display characteristics from a short distance together with the inter-pixel distance, so there is a problem with those characteristics. was there. Further, in the case of electronic paper in which a color filter layer is formed by an inkjet method as described in Patent Document 2, coating unevenness or the like occurs when forming colored pixels, which causes display defects and pixel formation accuracy. In that respect, it was not suitable for miniaturization of pixels. Therefore, there is a problem in visibility from a short distance and its display characteristics.

In view of such a situation, it is an object of the present invention to provide a color filter substrate having good visibility from a short distance, bright display, and vivid color, and a display device using such a color filter substrate.

The present invention is a color filter substrate having at least red pixels, green pixels, and blue pixels on the substrate, and the length of the minimum repeating unit is 100 μm or more and 160 μm or less.

According to the color filter substrate for electronic paper of the present invention, it is possible to provide a display device having good visibility from a short distance, bright display, and vivid display.

It is an example of arrangement of a red pixel, a green pixel, and a blue pixel, and is a figure which shows the minimum repeating unit. It is an example of the arrangement of a red pixel, a green pixel, a blue pixel, and a fourth sub-pixel, and is a figure which shows the minimum repeating unit. It is an example of arrangement of a red pixel, a green pixel, a blue pixel, and a yellow pixel, and is a figure which shows the minimum repeating unit. It is an example of arrangement of a red pixel, a green pixel, and a blue pixel having a hexagonal shape, and is a figure which shows the minimum repeating unit. It is an example of the arrangement of the red pixel, the green pixel, the blue pixel, and the fourth sub-pixel whose shape is hexagonal, and is the figure which shows the minimum repeating unit. It is an example of arrangement of a red pixel, a green pixel, a blue pixel, and a yellow pixel having a hexagonal shape, and is a figure which shows the minimum repeating unit. It is an example of the arrangement of the red pixel, the green pixel, the blue pixel, and the fourth sub-pixel which is the hexagonal shape which extended two sides among the six sides of a regular hexagon, and is the figure which shows the minimum repetition unit.

The color filter substrate for electronic paper of the present invention is a color filter substrate for electronic paper having at least red pixels, green pixels and blue pixels on the substrate, and the length of the minimum repeating unit is 100 μm or more and 160 μm or less. It is a color filter substrate for. By setting the length of the minimum repeating unit to 100 μm or more and 160 μm or less, it is possible to perform color display having excellent visibility and brightness on electronic paper.

The minimum repeating unit referred to here is a structural unit including at least red pixels, green pixels, and blue pixels, and refers to the smallest unit among the structural units that are repeatedly arranged on the surface of the color filter substrate. For example, when red pixel 1 (pixel shape is square), green pixel 2 (pixel shape is square), and blue pixel 3 (pixel shape is square) are repeatedly arranged as shown in FIG. 1, the minimum repetition unit 4 It becomes as follows. The arrangement of the red pixel, the green pixel, and the blue pixel is not particularly limited to the arrangement shown in FIG.

As shown in FIG. 2, when the red pixel 5 (pixel shape is square), the green pixel 6 (pixel shape is square), the blue pixel 7 (pixel shape is square), and the fourth sub-pixel are repeatedly arranged. The minimum repetition unit is 8. The arrangement of the red pixel, the green pixel, the blue pixel, and the fourth sub-pixel is not particularly limited to the arrangement shown in FIG. The fourth sub-pixel is an area provided so that the red pixel, the green pixel, and the blue pixel do not exist.

As shown in FIG. 3, red pixel 9 (pixel shape is square), green pixel 10 (pixel shape is square), blue pixel 11 (pixel shape is square), and yellow pixel 12 (pixel shape is square) are repeatedly arranged. If so, the minimum repetition unit is 13. The arrangement of the red pixel, the green pixel, the blue pixel, and the yellow pixel is not particularly limited to the arrangement shown in FIG.

As shown in FIG. 4, when the red pixel 14 (pixel shape is a regular hexagon), the green pixel 15 (pixel shape is a regular hexagon), and the blue pixel 16 (pixel shape is a regular hexagon) are repeatedly arranged, the minimum repetition unit. It becomes as shown in 17. The arrangement of the red pixel, the green pixel, and the blue pixel is not particularly limited to the arrangement shown in FIG.

As shown in FIG. 5, a red pixel 18 (pixel shape is a regular hexagon), a green pixel 19 (pixel shape is a regular hexagon), a blue pixel 20 (pixel shape is a regular hexagon), and a fourth sub-pixel are repeatedly arranged. If so, the minimum repetition unit 21 is set. The arrangement of the red pixel, the green pixel, the blue pixel, and the fourth sub-pixel is not particularly limited to the arrangement shown in FIG. The fourth sub-pixel is an area provided so that the red pixel, the green pixel, and the blue pixel do not exist.

As shown in FIG. 6, red pixel 22 (pixel shape is regular hexagon), green pixel 23 (pixel shape is regular hexagon), blue pixel 24 (pixel shape is regular hexagon), yellow pixel 25 (pixel shape is regular hexagon). When is repeatedly arranged, the minimum repetition unit is 26. The arrangement of the red pixel, the green pixel, the blue pixel, and the yellow pixel is not particularly limited to the arrangement shown in FIG.

FIG. 7 describes the definition of the minimum repeating unit for hexagonal pixels. FIG. 7 shows a hexagonal side and a parallel line drawn from it, and the parallel line is a figure composed of a straight line located in the center between each pixel such as a red pixel, a green pixel, a blue pixel, and a fourth sub-pixel. is there. Regarding the length of each pixel such as red pixel, green pixel, and blue pixel in FIG. 7, when the length of four sides of the six sides is A, the remaining two sides are "A + ((2.5 x A x)". Route 3) -3.5A) / 2 "(however, A is a positive number).

Further, the length of the minimum repeating unit means the length of one side when the minimum repeating unit is a square. In the case of a rectangle, it refers to the length of the long side. If the minimum repeating unit is different from the rectangle, the length of the minimum repeating unit is the length of the long side of the rectangle that can contain the minimum repeating unit (if the minimum rectangle is a square, one side). Length). From the viewpoint of visibility, the length of the minimum repeating unit is preferably 160 μm or less, more preferably 150 μm or less. Further, from the viewpoint of bonding accuracy between the array substrate and the color filter substrate, the length of the minimum repeating unit is preferably 100 μm or more, more preferably 120 μm or more. By setting the length of the minimum repeating unit to 100 μm or more, it is possible to suppress the difference in the tint of the display color when the bonding misalignment occurs.

As the substrate, for example, a plate of inorganic glass such as soda glass, non-alkali glass, borosilicate glass, quartz glass, aluminum borosilicate glass, aluminosilicate glass, alkaline aluminosilicate glass, and soda lime glass whose surface is silica-coated. And organic plastic films and sheets. A black matrix may be formed on these substrates.

Examples of the material constituting the pixel include a cured colored photosensitive composition containing a coloring material, a binder resin such as an acrylic resin or a polyimide resin, and a radically polymerizable compound. From the viewpoint of improving color purity, the pixel film thickness is preferably 0.5 μm or more, more preferably 1.0 μm or more, and even more preferably 1.4 μm or more. On the other hand, from the viewpoint of improving the flatness, pattern processability and reliability of the color filter substrate, 3.0 μm or less is preferable, and 2.8 μm or less is more preferable.

Examples of the coloring material contained in the colored photosensitive composition include organic pigments, inorganic pigments, dyes and the like, and two or more of these may be contained. Among these, organic pigments and dyes are preferable from the viewpoint of further improving the transmittance.

Examples of the red color material include C.I. I. Pigment Red (hereinafter "PR") 9, PR48, PR97, PR122, PR123, PR144, PR149, PR166, PR168, PR177, PR179, PR180, PR192, PR209, PR215, PR216, PR217, PR220, PR223, PR224, PR226 , PR227, PR228, PR240, PR254, diketopyrrolopyrrole coloring material having a bromine group, and the like. PR254, PR177, and diketopyrrolopyrrole colorant having a bromine group are preferable from the viewpoint of pixel brightness characteristics, and diketopyrrolopyrrole colorant having a bromine group is preferable from the viewpoint of brightness and vividness of the red display of electronic paper. Is preferably used. Further, from the viewpoint of the brightness, vividness, and display color of the red display of the electronic paper, the proportion of the diketopyrrolopyrrole color material having a bromine group in the color material contained in the red pixel is 70% by mass or more. Is preferable.

Examples of the green color material include C.I. I. Pigment Green (hereinafter referred to as "PG") PG1, PG2, PG4, PG7, PG8, PG10, PG13, PG14, PG15, PG17, PG18, PG19, PG26, PG36, PG38, PG39, PG45, PG48, PG50, PG51 , PG54, PG55, PG58, PG59 and the like. From the viewpoint of pixel brightness characteristics, PG58 and PG59 are preferable.

Examples of the yellow color material include C.I. I. Pigment Yellow (hereinafter, "PY") 12, PY13, PY17, PY20, PY24, PY83, PY86, PY93, PY95, PY109, PY110, PY117, PY125, PY129, PY137, PY138, PY139, PY147, PY148, PY150 , PY154, PY166, PY168, PY185 and the like. From the viewpoint of color purity, transmittance and contrast ratio, PY129, PY138, PY139 and PY150 are preferable, PY138 and PY150 are more preferable, and PY150 is further preferable.

Examples of the orange color material include C.I. I. Pigment orange (hereinafter, "PO") 13, PO31, PO36, PO38, PO40, PO42, PO43, PO51, PO55, PO59, PO61, PO64, PO65, PO71 and the like.

Examples of the blue pigment include C.I. I. Pigment blue (hereinafter, “PB”) 15, PB15: 3, PB15: 4, PB15: 6, PB21, PB22, PB60, PB64 and the like.

Examples of the purple pigment include C.I. I. Pigment Violet (hereinafter "PV") 19, PV23, PV29, PV30, PV32, PV37, PV40, PV50 and the like (all of the above numbers are color index Nos.).

Examples of the dye include oil-soluble dyes, acid dyes, direct dyes, basic dyes, and acid mordant dyes. Further, the dye may be raked, or may be used as a salt-forming compound of the dye and a nitrogen-containing compound.

Examples of red, green, blue, purple or yellow dyes include direct dyes, acid dyes, basic dyes and the like. Specific examples of these dyes include azo dyes, benzoquinone dyes, naphthoquinone dyes, anthraquinone dyes, xanthene dyes, cyanine dyes, squarylium dyes, croconium dyes, merocyanine dyes, and stillben dyes. Examples thereof include diarylmethane dyes, triarylmethane dyes, fluorane dyes, spiropyran dyes, phthalocyanine dyes, indigo dyes, flugide dyes, nickel complex dyes, and azulene dyes. The dye may be dissolved in the coloring composition or dispersed as particles.

Examples of the radically polymerizable compound contained in the colored photosensitive composition include the following.
Dipentaerythritol Penta (meth) acrylate, tetratrimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, penta (meth) acryloyloxydipentaerythritol monosuccinate, di Ethylene oxide-modified or propylene oxide-modified products such as pentaerythritol hexa (meth) acrylate, styrene derivatives, polyfunctional maleimide compounds, poly (meth) acrylate carbamate,
Bifunctional (meth) acrylates such as tripropylene glycol di (meth) acrylate and 1,6-hexanediol di (meth) acrylate,
Examples thereof include trimethylolpropane tri (meth) acrylate, triacrylic formal, bisphenoxyethanol full orange acrylate, dicyclopentanedienyldiacrylate, alkyl modified products thereof, alkyl ether modified products and alkyl ester modified products. Two or more of these may be contained.

Among these, a compound having a (meth) acryloyl group is preferable, and a polyfunctional compound having three or more (meth) acryloyl groups is preferable from the viewpoint of solubility and patterning property. By using a polyfunctional compound having three or more (meth) acryloyl groups, a film having excellent heat resistance and being sufficiently cured can be formed. Further, from the viewpoint of alkali developability, a compound having a carboxyl group is preferable. A compound having three or more (meth) acryloyl groups and a carboxyl group is more preferable. Examples of such a compound include penta (meth) acryloyloxydipentaerythritol monosuccinate.

The content of the radically polymerizable compound is preferably 40% by mass or more in the solid content from the viewpoint of patterning property. On the other hand, from the viewpoint of suppressing film thickness unevenness during film formation and suppressing pattern deformation due to flow during firing, the content of the radically polymerizable compound is preferably 90% by mass or less, preferably 70% by mass, based on the solid content. The following is more preferable, and 60% by mass or less is further preferable. From the viewpoint of patterning property, the content of the radically polymerizable compound having three or more (meth) acryloyl groups and a carboxyl group is preferably 50% by mass or more, and more preferably 60% by mass or more in the radically polymerizable compound. preferable.

In addition to the colored photosensitive composition, a binder resin, a dispersant, a photopolymerization initiator, a chain transfer agent, a sensitizer, an organic solvent, a polymerization inhibitor, an adhesion improver, a surfactant, an organic acid, an organic amino compound, It may contain a curing agent or the like.

Examples of the binder resin contained in the colored photosensitive composition include acrylic resin, epoxy resin, polyimide resin, urethane resin, urea resin, polyvinyl alcohol resin, melamine resin, polyamide resin, polyamideimide resin, polyester resin, and polyolefin resin. And so on. Two or more of these may be contained. Acrylic resin is preferably used from the viewpoint of stability.

As the acrylic resin, a copolymer of an unsaturated carboxylic acid and an ethylenically unsaturated compound is preferable.

Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinyl acetate, and acid anhydrides thereof. Two or more of these may be used.

The following are exemplified as ethylenically unsaturated compounds.
Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, sec-butyl (meth) acrylate, (meth) ) Iso-butyl acrylate, tert-butyl (meth) acrylate, n-pentyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, unsaturated carboxylic acid alkyl esters such as benzyl (meth) acrylate,
Aromatic vinyl compounds such as styrene, p-methylstyrene, o-methylstyrene, m-methylstyrene, α-methylstyrene,
Unsaturated carboxylic acid aminoalkyl esters such as aminoethyl acrylates,
Unsaturated carboxylic acid glycidyl esters such as glycidyl acrylate, glycidyl methacrylate,
Carboxylic acid vinyl esters such as vinyl acetate and vinyl propionate,
Vinyl cyanide compounds such as acrylonitrile, methacrylonitrile, α-chloroacrylonitrile,
Examples thereof include aliphatic conjugated diene such as 1,3-butadiene and isoprene, polystyrene having a (meth) acryloyl group at the terminal, polymethylacrylate, polymethylmethacrylate, polybutylacrylate, polybutylmethacrylate, macromonomer such as silicone and the like. .. Two or more of these may be used.

The acrylic resin preferably has an ethylenically unsaturated group in the side chain, which can improve the cross-linking rate of the polymer. Examples of the ethylenically unsaturated group include a vinyl group, an allyl group, an acrylic group, a methacrylic group and the like. Examples of the acrylic resin having an ethylenically unsaturated group in the side chain include "Cyclomer" (registered trademark) P (Daicel Chemical Industry Co., Ltd.) and an alkali-soluble cardo resin.

The weight average molecular weight of the binder resin is preferably 3,000 or more, more preferably 9,000 or more, from the viewpoint of the strength of the cured film. On the other hand, from the viewpoint of the stability of the coloring composition, the weight average molecular weight of the binder resin is preferably 200,000 or less, more preferably 100,000 or less. Here, the weight average molecular weight of the binder resin refers to a standard polystyrene-equivalent value measured by gel permeation glomatography.

The content of the binder resin is preferably 10% by mass or more, more preferably 20% by mass or more, and further preferably 30% by mass or more in the solid content from the viewpoint of suppressing uneven film thickness during film formation. On the other hand, from the viewpoint of patterning property, the content of the binder resin is preferably 60% by mass or less, more preferably 50% by mass or less in the solid content.

The color material contained in the color filter substrate for electronic paper of the present invention is subjected to mass spectrometry by laser Raman spectroscopy (Ar + laser (457.9 nm)), MALDI mass spectrometer or time-of-flight secondary ion mass spectrometer. Can be identified.

Examples of the dispersant that can be contained in the colored photosensitive composition include polyester, polyalkylamine, polyallylamine, polyimine, polyamide, polyurethane, polyacrylate, polyimide, polyamideimide, and copolymers thereof. .. Two or more of these may be contained. Among these polymer dispersants, those having an amine value of 5 to 200 mgKOH / g in terms of solid content and an acid value of 1 to 100 mgKOH / g are preferable. Among them, a polymer dispersant having a basic group is preferable, and the storage stability of the pigment dispersion liquid and the coloring composition can be improved. Commercially available polymer dispersants having a basic group include, for example, "Solspers" (registered trademark) (manufactured by Abyssia), "EFKA" (registered trademark) (manufactured by EFKA), and "Ajispar" (registered trademark). ) (Ajinomoto Fine-Techno Co., Ltd.), "BYK" (registered trademark) (manufactured by Big Chemie). Two or more of these may be contained. Among them, "Solspers" (registered trademark) 24000 (manufactured by Abyssia), "EFKA" (registered trademark) 4300, 4330 (manufactured by Fuka), 4340 (manufactured by Fuka), "Ajispar" (registered trademark) PB821, PB822 (Ajinomoto) Fine Techno Co., Ltd., "BYK" (registered trademark) 161 to 163, 2000, 2001, 6919, 21116 (manufactured by Big Chemie) are preferable.

Examples of the photopolymerization initiator that can be contained in the colored photosensitive composition include an oxime ester compound, a benzophenone compound, an acetophenone compound, an oxantone compound, an anthraquinone compound, an imidazole compound, and a benzothiazole compound. Examples thereof include benzoxazole-based compounds, carbazole-based compounds, triazine-based compounds, phosphorus-based compounds, and titanosen-based compounds.

More specifically, examples of the oxime ester compound include 1,2-octanedione, 1- [4- (phenylthio) phenyl]-, 2- (O-benzoyloxime), etanone, 1- [9-ethyl. -6- (2-methylbenzoyl) -9H-carbazole-3-yl]-, 1- (O-acetyloxime), etanone, 1- [9-ethyl-6- (2-methyl-4-tetrahydrofuranylmethoxy) Benzoyl) -9H-carbazole-3-yl]-, 1- (O-acetyloxime), etanone, 1- [9-ethyl-6- {2-methyl-4- (2,2-dimethyl-1,3) -Dioxolanyl) methoxybenzoyl} -9H-carbazole-3-yl]-, 1- (O-acetyloxime), 1,2-octanedione, 1- [4- (phenylthio) -2- (O-benzoyloxime) ], "Adeca Arculus" (registered trademark) N-1919, NCI-930 (manufactured by ADEKA Co., Ltd.), "IRGACURE" (registered trademark) OXE01, OXE02 (manufactured by BASF Co., Ltd.) and the like.

Examples of the benzophenone compound include benzophenone, N, N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone and the like.

Examples of the acetophenone compound include 2,2-diethoxyacetophenone, benzoin, benzoin methyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, α-hydroxyisobutylphenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1- [. 4- (Methylthio) phenyl] -2-morpholino-1-propane, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2- (dimethylamino) -2-[(4-4-) Methylphenyl) Methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one, "IRGACURE "(Registered trademark) 369, 379, 907 (manufactured by BASF Co., Ltd.) and the like.

Examples of anthraquinone compounds include t-butyl anthraquinone, 1-chloroanthraquinone, 2,3-dichloroanthraquinone, 3-chloro-2-methylanthraquinone, 2-ethylanthraquinone, 1,4-naphthoquinone, and 9,10-fe. Examples thereof include nantraquinone, 1,2-benzoanthraquinone, 1,4-dimethylanthraquinone and 2-phenylanthraquinone. Examples of the imidazole compound include 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer.

Examples of the benzothiazole-based compound include 2-mercaptobenzothiazole. Examples of the benzoxazole-based compound include 2-mercaptobenzoxazole. Examples of the triazine-based compound include 4- (p-methoxyphenyl) -2,6-di- (trichloromethyl) -s-triazine.

Two or more of these may be contained.

From the viewpoint of sensitivity, patterning property, and processability, the content of the photopolymerization initiator is preferably 1% by mass or more, more preferably 2% by mass or more, and 5% by mass, based on the solid content of the coloring composition excluding the coloring material. The above is more preferable. On the other hand, the content of the photopolymerization initiator is preferably 30% by mass or less, more preferably 20% by mass or less, based on the solid content of the coloring composition excluding the coloring material, from the viewpoints of sensitivity, patterning property, processability, and heat resistance. It is preferable, and 15% by mass or less is more preferable.

Examples of the polymerization chain transfer agent that can be contained in the colored photosensitive composition include thioglycolic acid, thioapple acid, thiosalicylic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 3-mercaptobutyric acid, and N- (2). -Mercaptopropionyl) glycine, 2-mercaptonicotinic acid, 3- [N- (2-mercaptoethyl) carbamoyl] propionic acid, 3- [N- (2-mercaptoethyl) amino] propionic acid, N- (3-mercapto) Propionyl) alanine, 2-mercaptoethanesulfonic acid, 3-mercaptopropanesulfonic acid, 4-mercaptobutanesulfonic acid, dodecyl (4-methylthio) phenyl ether, 2-mercaptoethanol, 3-mercapto-1,2-propanediol, 1-mercapto-2-propanol, 3-mercapto-2-butanol, mercaptophenol, 2-mercaptoethylamine, 2-mercaptoimidazole, 2-mercapto-3-pyridinol, 2-mercaptobenzothiazole, mercaptoacetic acid, trimethylpropanthris (3-Mercaptopropionate), 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione), penta Ellislitol tetrakis (3-mercaptopropionate), 1,4-bis (3-mercaptobutyryloxy) butane, "Karenzu" (registered trademark) MT PE-1 (manufactured by Showa Denko Co., Ltd.), "Karenzu" ( A mercapto compound such as MT NR-1 (manufactured by Showa Denko Co., Ltd.), "Karenzu" (registered trademark) MT BD-1 (manufactured by Showa Denko Co., Ltd.), etc., obtained by oxidizing the mercapto compound. Examples thereof include alkyl iodide compounds such as disulfide compounds, iodoacetic acid, iodopropionic acid, 2-iodoethanol, 2-iodoethanesulfonic acid and 3-iodopropanesulfonic acid. Two or more of these may be contained.

Examples of the sensitizer that can be contained in the colored photosensitive composition include thioxanthone-based sensitizers, aromatic or aliphatic tertiary amines, and the like. Examples of the thioxanthone-based sensitizer include thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthene-9-one, "KAYACURE" (registered trademark) DETX-S (manufactured by Nippon Kayaku Co., Ltd.), and the like. Can be mentioned. Two or more of these may be contained.

In the color filter substrate for electronic paper of the present invention, when the area of the minimum repeating unit is M, the colored area of the red pixel is R, the colored area of the green pixel is G, and the colored area of the blue pixel is B, G. It is preferable that <R and B <R are satisfied and R / M> is 0.175. By satisfying these conditions, it is possible to perform a display having excellent saturation and brightness at the time of displaying each color and brightness at the time of displaying white. When the sizes of the green pixels and the blue pixels are large, color mixing between the pixels is likely to occur from the viewpoint of the bonding accuracy of the array substrate and the color filter substrate, and in order to display a more vivid red color, G <R and B < R is preferable. Further, by setting G <R and B <R, not only the red display can be made bright and vivid, but also the decrease in brightness at the time of white display can be suppressed. Further, from the viewpoint of the vividness and brightness of the red display, R / M> 0.175 is preferable, R / M> 0.180 is more preferable, and R / M> 0.185 is more preferable. Further, from the viewpoint of the brightness of the white display of the electronic paper, R / M <0.4 is preferable, R / M <0.3 is more preferable, and R / M <0.2 is more preferable. The shape of the colored portion may be any of a rectangle such as a square or a rectangle, a circle or an ellipse, a hexagon or a regular hexagon. Further, it is preferable that the distance between the colored portions is wide from the viewpoint of the bonding accuracy between the array substrate and the color filter substrate. From the viewpoints of the R / M range, the bonding accuracy between the array substrate and the color filter substrate, and the spacing between the colored portions, it is preferable that the pixels are arranged in the center as shown in FIG. It is preferably square. Further, from the viewpoint of the R / M range, the bonding accuracy between the array substrate and the color filter substrate, and the spacing between the colored portions, it is preferable that the pixels are arranged in the center as shown in FIG. The shape is more preferably a regular hexagon. The area M of the minimum repeating unit 8 refers to the average of the areas of 50 minimum repeating units in the center and its vicinity in the region having the red pixel 5, the green pixel 6, and the blue pixel 7. The center here refers to the central portion of an area in which color pixels such as red pixels, green pixels, and blue pixels are repeatedly formed. Further, the colored area R of the red pixel refers to the average of the areas of 50 red pixels in the center and its vicinity in the region where the red pixel is located. Similarly, the colored area G of the green pixel is the average area of 50 green pixels in the center and its vicinity in the region with the green pixel, and the colored area B of the blue pixel is the region with the blue pixel. Among them, it refers to the average area of 50 blue pixels near the center. Further, the area M of the minimum repeating unit 17 refers to the average of the areas of 50 minimum repeating units in the center and its vicinity in a certain area of the red pixel 14, the green pixel 15, and the blue pixel 16. The center here refers to the central portion of an area in which color pixels such as red pixels, green pixels, and blue pixels are repeatedly formed. Further, the colored area R of the red pixel refers to the average of the areas of 50 red pixels in the center and its vicinity in the region where the red pixel is located. Similarly, the colored area G of the green pixel is the average area of 50 green pixels in the center and its vicinity in the region with the green pixel, and the colored area B of the blue pixel is the region with the blue pixel. Among them, it refers to the average area of 50 blue pixels near the center.

The color filter substrate for electronic paper of the present invention may have a fourth sub-pixel in addition to the red pixel, the green pixel, and the blue pixel. As for the hue of the fourth sub-pixel, the chromaticity coordinates (a *, b *) in the L * a * b * color system chromaticity diagram measured by the D65 light source are -5 <a * <7, -7. It is preferable to satisfy <b * <5. The hue of the fourth sub-pixel is -5 <a * <7, -7 in the chromaticity coordinates (a *, b *) in the L * a * b * chromaticity diagram measured with the D65 light source. By satisfying <b * <5, the white display of the electronic paper can be brightened, which is preferable.

Even when the color filter substrate for electronic paper of the present invention has a fourth sub-pixel, the area of the minimum repeating unit is M, the colored area of the red pixel is R, the colored area of the green pixel is G, and the area of the blue pixel is When the colored area is B, it is preferable that G <R and B <R are satisfied and R / M> 0.175. By satisfying these conditions, it is possible to perform a display having excellent saturation and brightness at the time of displaying each color and brightness at the time of displaying white. When the sizes of the green pixels and the blue pixels are large, color mixing between the pixels is likely to occur from the viewpoint of the bonding accuracy of the array substrate and the color filter substrate, and in order to display a more vivid red color, G <R and B < R is preferable. Further, by setting G <R and B <R, not only the red display can be made bright and vivid, but also the decrease in brightness at the time of white display can be suppressed. Further, from the viewpoint of the vividness and brightness of the red display, R / M> 0.175 is preferable, R / M> 0.180 is more preferable, and R / M> 0.185 is more preferable. Further, from the viewpoint of the brightness of the red display of the electronic paper, R / M <0.25 is preferable, R / M <0.21 is more preferable, and R / M <0.20 is more preferable. Further, from the viewpoint of the brightness of the white display of the electronic paper, R / M <0.3 is preferable, R / M <0.25, more preferably R / M <0.21, and even more preferably. R / M <0.20. The shape of the colored portion may be any of a rectangle such as a square or a rectangle, a circle or an ellipse, a hexagon or a regular hexagon. Further, it is preferable that the distance between the colored portions is wide from the viewpoint of the bonding accuracy between the array substrate and the color filter substrate. From the viewpoints of the R / M range, the bonding accuracy between the array substrate and the color filter substrate, and the spacing between the colored portions, it is preferable that the pixels are arranged in the center as shown in FIG. It is preferably square. Further, from the viewpoint of the R / M range, the bonding accuracy between the array substrate and the color filter substrate, and the spacing between the colored portions, it is preferable that the pixels are arranged in the center as shown in FIG. The shape is more preferably a regular hexagon.

Even when the fourth sub-pixel is provided, the area M of the minimum repeating unit refers to the average of the areas of 50 minimum repeating units in the center and its vicinity. Further, the colored area R of the red pixel refers to the average of the areas of 50 red pixels in the center and its vicinity in the region where the red pixel is located. Similarly, the colored area G of the green pixel is the average of the areas of 50 green pixels in the center and its vicinity in the area with the green pixel, and the colored area B of the blue pixel is the area with the blue pixel. Refers to the average of the areas of 50 blue pixels in and near the center.

The color filter substrate for electronic paper of the present invention may have yellow pixels in addition to red pixels, green pixels, and blue pixels. For example, the minimum repeating unit when red pixels (pixel shape is square), green pixels (pixel shape is square), blue pixels (pixel shape is square), and yellow pixels (pixel shape is square) are repeatedly arranged is shown in the figure. Shown in 3. The arrangement of the red pixel, the green pixel, the blue pixel, and the yellow pixel is not particularly limited to the arrangement shown in FIG.

From the viewpoint of widening the color gamut of electronic paper and the vividness of the yellow display of electronic paper, the hue of yellow pixels is the hue coordinates (a) in the L * a * b * color system chromaticity diagram measured with a D65 light source. It is preferable that * and b *) have a yellow hue satisfying -50 <a * <-20 and 80 <b * <100. When b * ≦ 80, the color gamut of the electronic paper is narrowed, and when b * ≧ 100, the brightness of the display is lowered.

When the color filter substrate for electronic paper of the present invention has red pixels, green pixels, blue pixels and yellow pixels, the area of the minimum repeating unit is M, the colored area of the red pixel is R, and the colored area of the green pixel is colored. When the area is G, the colored area of the blue pixel is B, and the colored area of the yellow pixel is Y, R <B, G <B and Y <B are satisfied, and B / M> 0.16. However, it is preferable from the viewpoint of the brightness and hue of the white display of the electronic paper. Further, from the viewpoint of the vividness and brightness of the red display of the electronic paper, G <R and Y <R are preferable. By satisfying these conditions, it is possible to perform a display having excellent saturation and brightness at the time of displaying each color and brightness at the time of displaying white. Further, in order to make the white display of the electronic paper brighter, it is preferable to satisfy R <B, G <B and Y <B. Further, from the viewpoint of the brightness of the white display of the electronic paper, B / M> 0.16 is preferable, and B / M> 0.17 is more preferable. Further, from the viewpoint of the brightness of the white display of the electronic paper, B / M <0.3 is preferable, R / M <0.25, and even more preferably R / M <0.2. The shape of the colored portion may be any of a rectangle such as a square or a rectangle, a circle or an ellipse, a hexagon or a regular hexagon. Further, it is preferable that the distance between the colored portions is wide from the viewpoint of the bonding accuracy between the array substrate and the color filter substrate. From the viewpoint of the B / M range, the bonding accuracy between the array substrate and the color filter substrate, and the spacing between the colored portions, it is preferable that the pixels are arranged in the center as shown in FIG. It is preferably square. Further, from the viewpoint of the R / M range, the bonding accuracy between the array substrate and the color filter substrate, and the spacing between the colored portions, it is preferable that the pixels are arranged in the center as shown in FIG. The shape is more preferably a regular hexagon. The area M of the minimum repeating unit refers to the average area of 50 minimum repeating units near the center in a region having red pixels, green pixels, blue pixels, and yellow pixels. Further, the colored area R of the red pixel refers to the average area of 50 red pixels near the center in the region where the red pixel is located. Similarly, the colored area G of the green pixel is the average area of 50 green pixels near the center in the area with the green pixel, and the colored area B of the blue pixel is the colored area B of the blue pixel in the area with the blue pixel. , The average area of 50 blue pixels near the center and the colored area Y of the yellow pixels refer to the average area of 50 yellow pixels near the center in the area with the yellow pixels.

In the color filter substrate for electronic paper of the present invention, the hue of red pixels is 70 <, and the hue coordinates (a *, b *) in the L * a * b * color system chromaticity diagram measured with a D65 light source are 70 <. It is preferable to satisfy a * <80 and 30 <b * <40. By satisfying these conditions, it is possible to display the electronic paper in red with excellent saturation and brightness. Further, from the viewpoint of display brightness, the L * in the L * a * b * color chromaticity diagram obtained by measuring the red pixels with a D65 light source is preferably 55 or more, more preferably 60 or more.

In the color filter substrate for electronic paper of the present invention, the hue of green pixels is -80 in the chromaticity coordinates (a *, b *) in the L * a * b * color system chromaticity diagram measured with a D65 light source. It is preferable to satisfy <a * <-70 and 40 <b * <60. By satisfying these conditions, it is possible to display the electronic paper in green with excellent saturation and brightness. Further, from the viewpoint of display brightness, L * in the L * a * b * color system chromaticity diagram obtained by measuring green pixels with a D65 light source is preferably 80 or more, and more preferably 85 or more.

In the color filter substrate for electronic paper of the present invention, the hue of blue pixels is 20 <, and the hue coordinates (a *, b *) in the L * a * b * color system chromaticity diagram measured with a D65 light source are 20 <. It is preferable to satisfy a * <30 and -80 <b * <-70. By satisfying these conditions, it is possible to perform a display having excellent saturation and brightness in the blue display of the electronic paper. Further, from the viewpoint of display brightness, L * in the L * a * b * color chromaticity diagram obtained by measuring blue pixels with a D65 light source is preferably 40 or more, and more preferably 45 or more.

When the color filter substrate for electronic paper of the present invention has yellow pixels, the hue of the yellow pixels is the chromaticity coordinates (a *, b *) in the L * a * b * color system chromaticity diagram measured by the D65 light source. ) Satisfies -50 <a * <-20 and 80 <b * <100. By satisfying these conditions, it is possible to display the electronic paper in yellow with excellent saturation and brightness. Further, from the viewpoint of display brightness, the L * in the L * a * b * color chromaticity diagram obtained by measuring the yellow pixels with a D65 light source is preferably 85 or more, more preferably 90 or more.

Regarding the arrangement of pixels of the color filter substrate for electronic paper of the present invention, when the color filter substrate has red pixels, green pixels, and blue pixels, red pixels 1, green pixels 2, and blue pixels are shown as shown in FIGS. 1 and 4. The arrangement of 3 and the arrangement of the red pixel 14, the green pixel 15, and the blue pixel 16 are exemplified, but the arrangement is not limited to those shown in FIGS. 1 and 4. Further, the shape of the pixel is not limited to a square, and may be a rectangle such as a rectangle. Further, it may be a polygon such as a hexagon or a circle. When the color filter substrate has a red pixel, a green pixel, a blue pixel, and a fourth sub-pixel, the red pixel 5, the green pixel 6, the blue pixel 7, and the fourth sub-pixel are shown in FIGS. 2, 5, and 7. Arrangement of 4 sub-pixels, arrangement of red pixel 18, green pixel 19, blue pixel 20, and 4th sub-pixel, arrangement of red pixel 27, green pixel 28, blue pixel 29, and 4th sub-pixel However, the arrangement is not limited to that shown in FIGS. 2, 5, and 7. Further, the shape of the pixel is not limited to a square, and may be a rectangle such as a rectangle. Further, it may be a polygon such as a hexagon or a circle. When the color filter substrate has red pixels, green pixels, blue pixels, and yellow pixels, for example, the arrangement of the red pixels, green pixels, blue pixels, and yellow pixels as shown in FIGS. 3 and 6 can be considered. , Is not limited to the arrangement of FIGS. 3 and 6. Further, the shape of the pixel is not limited to a square, and may be a rectangle such as a rectangle. Further, it may be a polygon such as a hexagon or a circle. Further, from the viewpoint of bonding accuracy between the array substrate and the color filter substrate, the pixel shape is preferably square, more preferably hexagonal, and even more preferably regular hexagon.

The color filter substrate for electronic paper of the present invention may further include a black matrix, an overcoat layer, a transparent electrode, a diffusion plate, and the like.

The black matrix prevents a decrease in contrast and color purity due to light leakage between pixels, and may be arranged between pixels, a part between pixels, or a frame portion. Examples of the material constituting the black matrix include a photosensitive composition containing a binder resin such as an acrylic resin and a polyimide resin and a radically polymerizable compound, and a non-photosensitive resin composition colored in black. The film thickness of the black matrix is preferably 0.5 μm or more, more preferably 1.0 μm or more, from the viewpoint of light-shielding property. On the other hand, from the viewpoint of workability, 2.0 μm or less is preferable, and 1.5 μm or less is more preferable.

The overcoat layer suppresses the transmission of impurities from the pixels of the color filter substrate and flattens the steps caused by the pixels of the color filter substrate. Examples of the material constituting the overcoat layer include an epoxy resin, an acrylic epoxy resin, an acrylic resin, a siloxane resin, a polyimide resin, and a photosensitive or non-photosensitive material commercially available as a flattening material. The film thickness of the overcoat layer is preferably 0.5 μm or more, more preferably 1.0 μm or more, from the viewpoint of workability. On the other hand, from the viewpoint of flatness of the color filter substrate, 5.0 μm or less is preferable, and 3.0 μm or less is more preferable.

Examples of the material constituting the transparent electrode include metals such as aluminum, chromium, tantalum, titanium, neodymium or molybdenum, Indium-Tin-Oxide (ITO), Indium-Zinc-Oxide (InZNO) and the like.

Examples of the method for manufacturing the color filter substrate include a method of forming a pattern of pixels made of a resin composition on the substrate. Hereinafter, a manufacturing method will be described using a color filter substrate having pixels made of a photosensitive coloring composition as an example. The photosensitive coloring composition of the present invention is applied onto a substrate, patterned by selective exposure and development using a photomask, and fired to form pixels, whereby a color filter substrate can be obtained.

Examples of the method of applying the colored photosensitive composition for forming the pixels on the substrate include a spin coater, a bar coater, a blade coater, a roll coater, a die coater, an inkjet printing method, a screen printing method, and a colored photosensitive composition of the substrate. Examples thereof include a method of immersing in the sex composition and a method of spraying the colored photosensitive composition onto the substrate. Subsequently, the substrate coated with the colored photosensitive composition is dried to form a coating film of the colored photosensitive composition on the substrate. Examples of the drying method include air drying, heat drying, vacuum drying and the like. Two or more of these may be combined, and for example, it is preferable to perform vacuum drying and then heat drying. The heat-drying temperature is preferably 80 to 130 ° C., and the heat-drying device is preferably a hot air oven or a hot plate. In the case of a color filter substrate having a black matrix, it is preferable to form a coating film of the colored photosensitive composition on the substrate on which the black matrix is formed in advance.

Next, a photomask is placed on the coating film of the colored photosensitive composition, and exposure is selectively performed. Examples of the exposure machine include a proximity exposure machine, a mirror projection exposure machine, a lens scan exposure machine, a stepper, and the like. From the viewpoint of accuracy, a lens scan exposure machine is preferable. Examples of the light source used for exposure include an ultra-high pressure mercury lamp, a chemical lamp, and a high pressure mercury lamp.

Then, the unexposed portion is removed by development with an alkaline developer to form a coating film pattern. Examples of the alkaline substance used in the alkaline developing solution include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine and the like. Examples thereof include primary amines, secondary amines such as diethylamine and di-n-propylamine, tertiary amines such as triethylamine and methyldiethylamine, and organic alkalis such as tetramethylammonium hydroxide. Examples of the alkaline developer include 0.02 to 1% by mass of potassium hydroxide or tetramethylammonium hydroxide. Examples of the developing method include a method of immersing the coating film after exposure in an alkaline developer for 20 to 300 seconds.

Then, the obtained coating film pattern is heat-treated to obtain a color filter substrate in which the pixels are patterned. The heat treatment may be performed in air, in a nitrogen atmosphere, or in vacuum. The heating temperature is preferably 150 to 350 ° C, more preferably 180 to 250 ° C. The heating time is preferably 5 minutes to 5 hours. As the heat treatment apparatus, a hot air oven and a hot plate are preferable. The heat treatment may be performed continuously or stepwise.

Pixels are sequentially formed for each of the 3 to 6 color pixels of the color filter substrate by the above method. The formation order of each color is not particularly limited.

The electronic paper of the present invention is characterized by comprising the color filter substrate for the electronic paper of the present invention and an electrophoresis display layer. The electrophoresis display layer refers to a member having a display medium that switches between black and white display by moving white particles and black particles by an electric field. Examples of the electrophoresis display layer include those in which microcapsules containing white particles and black particles in a dispersion liquid made of a transparent dispersion medium are fixed with a binder resin. As the transparent dispersion medium, for example, various organic compounds such as an alcohol solvent and an aliphatic hydrocarbon can be used. As the white particles, for example, a white pigment such as titanium dioxide can be used, and as the black particles, for example, a black pigment such as carbon black or titanium black can be used. As a material for forming the wall film of the microcapsules, for example, a urethane resin, a urea resin, a composite film of gum arabic / gelatin, or the like can be used. As the binder resin, one having good affinity for the wall film of the microcapsules and having insulating properties can be used. Such an electrophoresis display layer can be formed, for example, by coating microcapsules dispersed in a binder resin and inked. The electronic paper may have an optical film, a surface protective film, a barrier layer, a touch panel layer, and the like for improving visibility and light reflection characteristics.

The electronic paper of the present invention has a fourth sub-pixel in addition to the red pixel, green pixel, and blue pixel, and the fourth sub-pixel hue is an L * a * b * table measured by a D65 light source. When the color filter substrate in which the chromaticity coordinates (a *, b *) in the chromaticity diagram satisfy -5 <a * <7 and -7 <b * <5 is provided, the white display of the electronic paper is more suitable. In order to display a display close to white, it is preferable that the reflectance of the red pixel portion of the electronic paper is smaller than the reflectance of the green pixel portion and the reflectance of the red pixel portion is smaller than the reflectance of the blue pixel portion. The white display referred to here refers to a display used as a background of the characters when displaying the characters on electronic paper. By controlling the reflectance of the red pixel portion, the green pixel portion, and the blue pixel portion in this way, it is possible to perform a white display closer to white while making the colors at the time of red, green, and blue display vivid.

When the electronic paper of the present invention has a color filter substrate having yellow pixels in addition to the red pixels, green pixels, and blue pixels, the red of the electronic paper is displayed in order to display a display closer to white in the white display of the electronic paper. It is preferable that the reflectance of the pixel portion is smaller than the reflectance of the green pixel portion and the reflectance of the red pixel portion is smaller than the reflectance of the blue pixel portion. The white display referred to here refers to a display used as a background of the characters when displaying the characters on electronic paper. By controlling the reflectance of the red pixel part, the green pixel part, the blue pixel part, and the yellow pixel part in this way, the white display closer to white can be obtained while making the colors when displaying red, green, blue, and yellow vivid. It can be carried out.

The present invention will be described below with reference to examples, but the present invention is not limited to these examples. First, the evaluation methods in Examples and Comparative Examples will be described.

<Visibility evaluation>
It has red pixel 5 (pixel shape is square), green pixel 6 (pixel shape is square), blue pixel 7 (pixel shape is square), and a transparent fourth sub-pixel shown in FIG. 2, and the minimum repetition unit is square. The color (L *, a *, b *) of each color pixel in the L * a * b * color system chromaticity diagram measured with the D65 light source is the red pixel (62.6, 70.2). , 33.4), green pixel (85.8, -77.3, 50.7), blue pixel (48.6, 27.5, -71.7), fourth sub-pixel (99.4, In 5.2 and -5.5), the distance at which the pixel shape can be confirmed with a visual visual value of 0.5 was evaluated in pixel arrangements in which the length of the minimum repeating unit and the colored pixel size are different. The evaluation criteria were as follows. Those with a small number of evaluation ranks are preferable.
1: Confirmable distance is less than 30 cm 2: Confirmable distance is 30 cm or more and less than 40 cm 3: Confirmable distance is 40 cm or more and less than 50 cm 4: Confirmable distance is 50 cm or more <Display evaluation>
It has red pixel 5 (pixel shape is square), green pixel 6 (pixel shape is square), blue pixel 7 (pixel shape is square), and a transparent fourth sub-pixel shown in FIG. 2, and the minimum repetition unit is square. The colors (L *, a *, b *) of each color pixel in the L * a * b * color chromaticity diagram measured with the D65 light source are red pixels (62.6, 70.2). , 33.4), green pixel (85.8, -77.3, 50.7), blue pixel (48.6, 27.5, -71.7), fourth sub-pixel (99.4, L when the color filter substrate showing 5.2 and -5.5) and the array substrate are bonded together, the reflection intensity of the red pixel portion is maximized, and the reflection intensity of other regions is minimized (hereinafter, red display). * And saturation were evaluated. Further, the color change (ΔEab) of the red display when the bonding of the color filter substrates was deviated by 10 μm in each of the X direction and the Y direction was evaluated.

Production Example 1 (Preparation of dispersion liquid (A1))
112 g of a diketopyrrolopyrrole pigment having a bromine group (formula (1)) was obtained in the same manner as described in JP-A-2016-176058, specification [0116] to [0120].

100 g of the obtained diketopyrrolopyrrole pigment having a bromine group, 50 g of a polymer dispersant (“BYK-6919” manufactured by Big Chemie Japan Co., Ltd.), a binder polymer (manufactured by Daicel Co., Ltd., “Cyclomer®”) 66.7 g of P ”, ACA250, 45% by mass solution) and 450 g of PGME were mixed to prepare a slurry. A beaker containing the slurry was connected to a dyno mill with a tube, and zirconia beads having a diameter of 0.5 mm were used as a medium for dispersion treatment at a peripheral speed of 14 m / s for 8 hours to disperse diketopyrrolopyrrole pigment having a bromine group. Liquid (A1) was prepared.

Production Example 2 (Preparation of dispersion liquid (A2))
C. I. Pigment Red 177 (manufactured by Dainichi Seika Kogyo Co., Ltd., "Chromofine (registered trademark) Red 6125EC") 150 g, polymer dispersant ("BYK-6919" manufactured by Big Chemie Japan Co., Ltd.) 75 g, binder polymer ((( A slurry was prepared by mixing 100 g of "Cyclomer (registered trademark) P", ACA250, 45% by mass solution) and PGME 675 g manufactured by Daicel Co., Ltd. A beaker containing the slurry is connected to a dyno mill with a tube, and zirconia beads having a diameter of 0.5 mm are used as a medium for dispersion treatment at a peripheral speed of 14 m / s for 8 hours to prepare Pigment Red 177 dispersion (A2). did.

Production Example 3 (Preparation of dispersion (A3))
C. I. Pigment Green 58 150g, Polymer Dispersant ("BYK-6919" manufactured by Big Chemie Japan Co., Ltd.), Binder Polymer (manufactured by Daicel Co., Ltd., "Cyclomer (registered trademark) P", ACA250, 45% by mass solution ) 100 g and PGME 675 g were mixed to prepare a slurry. A beaker containing the slurry is connected to a dyno mill with a tube, and zirconia beads having a diameter of 0.5 mm are used as a medium to carry out dispersion treatment at a peripheral speed of 14 m / s for 8 hours to prepare Pigment Green 58 dispersion (A3). did.

Production Example 4 (Preparation of dispersion (A4))
C. I. Pigment Yellow 150 150g, Polymer Dispersant (“BYK-6919” manufactured by Big Chemie Japan Co., Ltd.), 75g, Binder Polymer (manufactured by Daicel Co., Ltd., “Cyclomer® P”, ACA250, 45% by mass solution ) 100 g and PGME 675 g were mixed to prepare a slurry. A beaker containing the slurry is connected to a dyno mill with a tube, and zirconia beads having a diameter of 0.5 mm are used as a medium for dispersion treatment at a peripheral speed of 14 m / s for 8 hours to prepare Pigment Yellow 150 dispersion (A4). did.

Production Example 5 (Preparation of dispersion (A5))
C. I. Pigment Blue 15: 6 150 g, Polymer Dispersant (“BYK-6919” manufactured by Big Chemie Japan Co., Ltd.) 75 g, Binder Polymer (manufactured by Daicel Co., Ltd., “Cyclomer® P”, ACA250, 45 mass % Solution) 100 g and PGME 675 g were mixed to prepare a slurry. A beaker containing the slurry was connected to a dyno mill with a tube, and zirconia beads having a diameter of 0.5 mm were used as a medium for dispersion treatment at a peripheral speed of 14 m / s for 8 hours. Pigment Blue 15: 6 dispersion (A5) Was prepared.

Production Example 6 (Preparation of dispersion (A6))
C. I. Pigment Violet 23 150g, Polymer Dispersant ("BYK-6919" manufactured by Big Chemie Japan Co., Ltd.), Binder Polymer (manufactured by Daicel Co., Ltd., "Cyclomer (registered trademark) P", ACA250, 45% by mass solution ) 100 g and PGME 675 g were mixed to prepare a slurry. A beaker containing the slurry is connected to a dyno mill with a tube, and zirconia beads having a diameter of 0.5 mm are used as a medium to carry out dispersion treatment at a peripheral speed of 14 m / s for 8 hours to prepare Pigment Violet 23 dispersion (A6). did.

Production Example 7 (Synthesis of binder resin solution (B1))
Methyl methacrylate 33 g (0.3 mol), styrene 33 g (0.3 mol), methacrylic acid 34 g (0.4 mol), 2,2'-azobis (2-methylbutyronitrile) 3 g (0) in a 500 mL three-necked flask. .02 mol) and 150 g of propylene glycol monomethyl ether acetate (PGMEA) were charged, and the mixture was stirred at 90 ° C. for 2 hours, the internal temperature was raised to 100 ° C., and the mixture was further stirred for 1 hour to obtain a reaction solution. To the obtained reaction solution, 33 g (0.2 mol) of glycidyl methacrylate, 1.2 g (0.009 mol) of dimethylbenzylamine and 0.2 g (0.002 mol) of p-methoxyphenol were added, and 4 at 90 ° C. After stirring for a time, 50 g of PGMEA was added to obtain a binder resin solution (B1) having a solid content concentration of 40% by mass. When the acid value of the binder resin was measured for a 0.1 mol / L potassium hydroxide / ethanol solution using an automatic potential difference measuring device AT-610 manufactured by Kyoto Denshi Kogyo Co., Ltd., the acid value was 80.0 (mgKOH / mgKOH /). g). Moreover, when the polystyrene-equivalent weight average molecular weight was calculated using a GPC apparatus, the weight average molecular weight was 22,000.

Production Example 8
In a 50 mL plastic bottle, 5.42 g of the dispersion liquid A1 obtained in Production Example 1, 0.11 of the dispersion liquid obtained in Production Example 4, 3.11 g of the binder resin solution B1 obtained in Production Example 7, and penta ( Meta) Acryloyloxydipentaerythritol monosuccinic acid ester (C1) 1.49 g, N-1919 (manufactured by ADEKA Corporation) 0.12 g, dipropylene glycol methyl ether acetate (hereinafter, DPMA) 19.75 g were added, and 3 Stirring for hours prepared a colored composition. The obtained coloring composition was applied by spin coating, and then heat-dried at 90 ° C. for 10 minutes. The obtained colored composition coating film was exposed to an i-line of 200 mJ / cm2 via a negative photomask, and then developed with a 0.3% by mass tetramethylammonium hydroxide aqueous solution at 23 ° C. .. Subsequently, heat treatment was performed at 230 ° C. for 30 minutes, and the colors (L *, a *, b *) of each color pixel in the L * a * b * color system chromaticity diagram measured with a D65 light source were (62.6). , 70.2, 33.4) formed red pixels.

Manufacturing example 9
In a 50 mL plastic bottle, 6.40 g of the dispersion liquid A3 obtained by Production Example 3, 1.03 g of the dispersion liquid A4 obtained by Production Example 4, 3.11 g of the binder resin solution B1 obtained by Production Example 7, and penta ( Meta) Add 1.05 g of acryloyloxydipentaerythritol monosuccinate (C1), 0.04 g of N-1919 (manufactured by ADEKA Corporation), and 18.35 g of DPMA, and stir for 3 hours to prepare a coloring composition. did. The obtained coloring composition was applied by spin coating, and then heat-dried at 90 ° C. for 10 minutes. The obtained colored composition coating film was exposed to an i-line of 200 mJ / cm2 via a negative photomask, and then developed with a 0.3% by mass tetramethylammonium hydroxide aqueous solution at 23 ° C. .. Subsequently, heat treatment was performed at 230 ° C. for 30 minutes, and the colors (L *, a *, b *) of each color pixel in the L * a * b * color system chromaticity diagram measured with a D65 light source were (85.8). , -77.3, 50.7) green pixels were formed.

Production Example 10
In a 50 mL plastic bottle, 2.09 g of the dispersion liquid A5 obtained by Production Example 5, 1.12 g of the dispersion liquid A6 obtained by Production Example 6, 3.24 g of the binder resin solution B1 obtained by Production Example 7, and penta ( Meta) Add 0.95 g of acryloyloxydipentaerythritol monosuccinate (C1), 0.07 g of N-1919 (manufactured by ADEKA Corporation), and 21.36 g of DPMA, and stir for 3 hours to prepare a coloring composition. did. The obtained coloring composition was applied by spin coating, and then heat-dried at 90 ° C. for 10 minutes. The obtained colored composition coating film was exposed to an i-line of 200 mJ / cm2 via a negative photomask, and then developed with a 0.3% by mass tetramethylammonium hydroxide aqueous solution at 23 ° C. .. Subsequently, heat treatment was performed at 230 ° C. for 30 minutes, and the colors (L *, a *, b *) of each color pixel in the L * a * b * color chromaticity diagram measured with a D65 light source were (48.6). , 27.5, -71.7).

Production Example 11
In a 50 mL plastic bottle, 8.68 g of the dispersion liquid A2 obtained in Production Example 2, 2.61 g of the binder resin solution B1 obtained in Production Example 7, penta (meth) acryloyloxydipentaerythritol monosuccinate (C1). 1.35 g, manufactured by ADEKA Corporation, N-1919, 0.12 g, and 17.26 g of DPMA were added, and the mixture was stirred for 3 hours to prepare a coloring composition. The obtained coloring composition was applied by spin coating, and then heat-dried at 90 ° C. for 10 minutes. The obtained colored composition coating film was exposed to an i-line of 200 mJ / cm2 via a negative photomask, and then developed with a 0.3% by mass tetramethylammonium hydroxide aqueous solution at 23 ° C. .. Subsequently, heat treatment was performed at 230 ° C. for 30 minutes, and the colors (L *, a *, b *) of each color pixel in the L * a * b * color chromaticity diagram measured with a D65 light source were (59.3). , 69.3, 6.5) formed red pixels.

Production Example 12
In a 50 mL plastic bottle, 4.34 g of the dispersion liquid A1 obtained by Production Example 1, 4.34 g of the dispersion liquid A2 obtained by Production Example 2, 2.61 g of the binder resin solution B1 obtained by Production Example 7, and penta ( Meta) Acryloyloxydipentaerythritol monosuccinic acid ester (C1) 1.35 g, N-1919 (manufactured by ADEKA Corporation) 0.12 g, DPMA 17.26 g were added and stirred for 3 hours to prepare a coloring composition. did. The obtained coloring composition was applied by spin coating, and then heat-dried at 90 ° C. for 10 minutes. The obtained colored composition coating film was exposed to an i-line of 200 mJ / cm2 via a negative photomask, and then developed with a 0.3% by mass tetramethylammonium hydroxide aqueous solution at 23 ° C. .. Subsequently, heat treatment was performed at 230 ° C. for 30 minutes, and the colors (L *, a *, b *) of each color pixel in the L * a * b * color system chromaticity diagram measured with a D65 light source were (59.4). , 70.1, 18.6) formed red pixels.

Production Example 13
In a 50 mL plastic bottle, 4.34 g of the dispersion liquid A1 obtained by Production Example 1, 4.34 g of the dispersion liquid A4 obtained by Production Example 4, 2.61 g of the binder resin solution B1 obtained by Production Example 7, and penta ( Meta) Acryloyloxydipentaerythritol monosuccinic acid ester (C1) 1.35 g, N-1919 (manufactured by ADEKA Corporation) 0.12 g, DPMA 17.26 g were added and stirred for 3 hours to prepare a coloring composition. did. The obtained coloring composition was applied by spin coating, and then heat-dried at 90 ° C. for 10 minutes. The obtained colored composition coating film was exposed to an i-line of 200 mJ / cm2 via a negative photomask, and then developed with a 0.3% by mass tetramethylammonium hydroxide aqueous solution at 23 ° C. .. Subsequently, heat treatment was performed at 230 ° C. for 30 minutes, and the colors (L *, a *, b *) of each color pixel in the L * a * b * color system chromaticity diagram measured with a D65 light source were (69.9). , 46.4, 62.3) formed red pixels.

Example 1
According to the procedure of the visibility evaluation, the pixel arrangement having the length of the minimum repeating unit of 150 μm was confirmed, and the distance at which the pixel shape could be confirmed was about 25.8 cm.

Examples 2-4, Comparative Examples 1-4
The length of the minimum repeating unit is changed as shown in Table 1, and the results evaluated by the above method are summarized in Table 1.

Example 5
In the display evaluation, when the length of the minimum repeating unit is 150 μm, the red pixel size is 45 μm, the green pixel size is 45 μm, the blue pixel size is 45 μm, and the R / M is 0.090, L * and saturation at the time of red display are displayed. Was 36.1 and 5.1, respectively. In addition, the color change of the red display when the color filter substrates were misaligned was 0.

Examples 6 to 15, Comparative Example 5
The length of the minimum repeating unit, the colored pixel size, and the R / M are changed as shown in Table 2, and the results evaluated by the above method are summarized in Table 2.

Example 16
The colors (L *, a *, b *) of each color pixel in the L * a * b * color chromaticity diagram measured with the D65 light source are red pixels (59.3, 69.3, 6.5). When the display was evaluated in the same manner as in Example 8, L * and saturation at the time of red display were 28.9 and 9.0, respectively. In addition, the color change of the red display when the color filter substrates were misaligned was 0.80.

Example 17
The colors (L *, a *, b *) of each color pixel in the L * a * b * color chromaticity diagram measured with the D65 light source are red pixels (59.3, 69.3, 6.5). When the display was evaluated in the same manner as in Example 12, L * and saturation at the time of red display were 29.1 and 9.1, respectively. In addition, the color change of the red display when the color filter substrates were misaligned was 0.77.

Example 18
The colors (L *, a *, b *) of each color pixel in the L * a * b * color chromaticity diagram measured with the D65 light source are red pixels (59.4, 69.9, 18.5). When the display was evaluated in the same manner as in Example 12, L * and saturation at the time of red display were 29.4 and 9.2, respectively. In addition, the color change of the red display when the color filter substrates were misaligned was 0.74.

Example 19
The colors (L *, a *, b *) of each color pixel in the L * a * b * color chromaticity diagram measured with the D65 light source are red pixels (69.9, 46.4, 62.3). When the display was evaluated in the same manner as in Example 12, L * and saturation at the time of red display were 30.6 and 9.8, respectively. In addition, the color change of the red display when the color filter substrates were misaligned was 0.73.

Example 20
It has red pixel 5 (pixel shape is square), green pixel 6 (pixel shape is square), blue pixel 7 (pixel shape is square), and a transparent fourth sub-pixel shown in FIG. 2, and the minimum repetition unit is square. The size of the red pixel, the green pixel, and the blue pixel are 60 μm, 60 μm, 60 μm, respectively, and the color of each color pixel (L *) in the L * a * b * color system chromaticity diagram measured by the D65 light source. , A *, b *) are red pixels (62.6, 70.2, 33.4), green pixels (85.8, -77.3, 50.7), blue pixels (48.6, 27.). In 5, -71.7) and the fourth sub-pixel (99.4, 5.2, -5.5), the reflection intensity of the green pixel portion, the blue pixel portion, and the fourth sub-pixel portion is maximized (16). When the white display was evaluated when the reflection intensity of the red pixel portion was set to 16/16 (= 1), L *, a *, and b * were 53.2, -1.30, respectively. It was 0.67.

Examples 21-29
Table 3 summarizes the evaluation results in the same manner as in Example 20 except that the length of the minimum repeating unit, each colored pixel size, R / M, and the reflection intensity of each pixel portion were changed as described in Table 3. ..

Example 30
It has a red pixel 9 (pixel shape is square), a green pixel 10 (pixel shape is square), a blue pixel 11 (pixel shape is square), and a yellow pixel 12 (pixel shape is square) shown in FIG. Is a square pixel arrangement, the length of the minimum repeating unit is 150 μm, and the sizes of red pixels, green pixels, blue pixels, and yellow pixels are 60 μm, 60 μm, 60 μm, 60 μm, and L * a * measured with a D65 light source, respectively. The colors (L *, a *, b *) of each color pixel in the b * color system chromaticity diagram are red pixels (62.6, 70.2, 33.4) and green pixels (85.8, -77.). 3,50.7), blue pixels (48.6, 27.5, -71.7), yellow pixels (94.8, -38.6, 83.3), red pixel part, green pixel part, When the white display when the reflection intensity of the blue pixel part and the yellow pixel part was maximized (16/16) was evaluated, L *, a *, and b * were 50.7, -5.94, and 9. It was 75.

Example 31
The minimum repeating unit is a square pixel arrangement, the length of the minimum repeating unit is 150 μm, and the color of each color pixel (L *, a *, in the L * a * b * color system chromaticity diagram measured with a D65 light source. b *) are red pixels (62.6, 70.2, 33.4), green pixels (85.8, -77.3, 50.7), blue pixels (48.6, 27.5, -71). .7), yellow pixel (94.8, -38.6, 83.3), R / M = 0.133, B / M = 0.212, G / M = 0.083, Y / M = 0 In 0.088, when the white display when the reflection intensity of the red pixel portion, the green pixel portion, the blue pixel portion, and the yellow pixel portion was maximized (16/16) was evaluated, L *, a *, and b * were found to be. It was 48.2, -1.21 and 0.72, respectively.

Example 32
Red pixel 27 (pixel shape is hexagonal, four-sided length is 28.4 μm, R / M = 0.176) and green pixel 28 (pixel shape is hexagonal, four-sided length is 28.4 μm) shown in FIG. ), Blue pixel 29 (pixel shape is hexagonal, four-sided length is 28.4 μm), has a transparent fourth sub-pixel, and has a pixel arrangement with a minimum repeating unit of 30 (minimum repeating unit length). 150 μm), and the colors (L *, a *, b *) of each color pixel in the L * a * b * color chromaticity diagram measured with the D65 light source are red pixels (62.6, 70.2). , 33.4), green pixel (85.8, -77.3, 50.7), blue pixel (48.6, 27.5, -71.7), fourth sub-pixel (99.4, When the color filter substrate showing 5.2 and -5.5) and the array substrate are bonded together, the reflection intensity of the red pixel portion is maximized, and the reflection intensity of the other regions is minimized, L * is 30.8. The saturation was 10.2. Further, the color change (ΔEab) of the red display when the bonding of the color filter substrates was deviated by 10 μm in each of the X direction and the Y direction was 0.74.

1 Red pixel 2 Green pixel 3 Blue pixel 4 Minimum repeat unit 5 Red pixel 6 Green pixel 7 Blue pixel 8 Minimum repeat unit 9 Red pixel 10 Green pixel 11 Blue pixel 12 Yellow pixel 13 Minimum repeat unit 14 Red pixel 15 Green pixel 16 Blue Pixel 17 Minimum repeat unit 18 Red pixel 19 Green pixel 20 Blue pixel 21 Minimum repeat unit 22 Red pixel 23 Green pixel 24 Blue pixel 25 Yellow pixel 26 Minimum repeat unit 27 Red pixel 28 Green pixel 29 Blue pixel 30 Minimum repeat unit

The color filter substrate of the present invention can be suitably used for electronic paper.

Claims (19)

A color filter substrate having at least red pixels, green pixels, and blue pixels on the substrate.
A color filter substrate for electronic paper having a minimum repeating unit length of 100 μm or more and 160 μm or less. When the area of the minimum repeating unit is M, the colored area of the red pixel is R, the colored area of the green pixel is G, and the colored area of the blue pixel is B, G <R and B <R are satisfied and R. The color filter substrate for electronic paper according to claim 1, wherein / M> 0.175. Further, the fourth sub-pixel has a fourth sub-pixel, and the chromaticity coordinates (a *, b *) in the L * a * b * color system chromaticity diagram measured by the D65 light source are the hues of the fourth sub-pixel. , -5 <a * <7, -7 <b * <5. The color filter substrate for electronic paper according to claim 1 or 2. Further, the hue of the yellow pixel having yellow pixels is -50 <a *) in the chromaticity coordinates (a *, b *) in the L * a * b * color system chromaticity diagram measured by the D65 light source. The color filter substrate for electronic paper according to claim 1, which has a yellow hue satisfying <-20 and 80 <b * <100. The color filter substrate for electronic paper according to claim 4, wherein the area of the minimum repetition unit is M, the colored area of the red pixel is R, the colored area of the green pixel is G, and the colored area of the blue pixel is B. The color filter substrate for electronic paper according to claim 4, wherein when the colored area of the yellow pixel is Y, R <B, G <B and Y <B are satisfied, and B / M> 0.16. Further, the color filter substrate for electronic paper according to claim 4 or 5, wherein G <R and Y <R. The color filter substrate for electronic paper according to any one of claims 1 to 6, wherein the proportion of the diketopyrrolopyrrole color material having a bromine group in the color material contained in the red pixel is 70% by mass or more. The hue of the red pixel is 70 <a * <80, 30 <b * <the chromaticity coordinates (a *, b *) in the L * a * b * color system chromaticity diagram measured with the D65 light source. The color filter substrate for electronic paper according to any one of claims 1 to 7, which has a red hue satisfying 40. The hue of the green pixel is -80 <a * <-70, 40 <b in the chromaticity coordinates (a *, b *) in the L * a * b * color system chromaticity diagram measured with the D65 light source. * The color filter substrate for electronic paper according to any one of claims 1 to 8, which has a green hue satisfying 60. The hue of the blue pixel is 20 <a * <30, -80 <b *) in the chromaticity coordinates (a *, b *) in the L * a * b * color system chromaticity diagram measured with the D65 light source. The color filter substrate for electronic paper according to any one of claims 1 to 9, which has a blue hue satisfying <-70. The color filter substrate for electronic paper according to any one of claims 1 to 10, wherein the shape of any of the red pixel, the green pixel, and the blue pixel is a hexagon. The color filter substrate for electronic paper according to any one of claims 1 to 11, wherein the shapes of the red pixel, the green pixel, and the blue pixel are hexagonal. The color filter substrate for electronic paper according to any one of claims 2 to 3 and 7 to 12, wherein the shape of the fourth sub-pixel is hexagonal. The color filter substrate for electronic paper according to any one of claims 4 to 12, wherein the shape of the yellow pixel is hexagonal. An electronic paper having the color filter substrate for electronic paper and the electrophoresis display layer according to any one of claims 1 to 14. The chromaticity coordinates (a *, b *) in the L * a * b * color system chromaticity diagram measured by the D65 light source and having the fourth sub-pixel and the fourth sub-pixel hue are The reflectance of the red pixel portion of the electronic paper according to claim 15, which uses a color filter substrate for electronic paper satisfying -5 <a * <7 and -7 <b * <5, is smaller than the reflectance of the green pixel portion. A white display method in which the reflectance of the red pixel portion is made smaller than the reflectance of the blue pixel portion. The reflectance of the red pixel portion of the electronic paper according to claim 15, which uses a color filter substrate for electronic paper having yellow pixels, is smaller than the reflectance of the green pixel portion, and the reflectance of the red pixel portion is set to that of the blue pixel portion. A white display method that makes it smaller than the reflectance. A method for displaying white electronic paper using a color filter substrate having at least red pixels, green pixels, blue pixels, and a fourth sub-pixel on the substrate, wherein the color filter substrate has an area of a minimum repetition unit of M. When the colored area of the red pixel is R, the colored area of the green pixel is G, and the colored area of the blue pixel is B, G <R and B <R, and R / M> 0.175, and the above. The fourth sub-pixel hue is the chromaticity coordinates (a *, b *) in the L * a * b * color system chromaticity diagram measured with the D65 light source, and the chromaticity coordinates (a *, b *) are -5 <a * <7, -7 <. B * <5 is satisfied, and the reflectance of the red pixel portion of the electronic paper using the color filter substrate is made smaller than the reflectance of the green pixel portion, and the reflectance of the red pixel portion is made smaller than the reflectance of the blue pixel portion. White display method. A white display method for electronic paper using a color filter substrate having at least red pixels, green pixels, blue pixels, and yellow pixels on the substrate, wherein the color filter substrate has an area of a minimum repetition unit of M, and the red pixels. When the colored area is R, the colored area of the green pixel is G, the colored area of the blue pixel is B, and the colored area of the yellow pixel is Y, R <B, G <B and Y <B, and B / M> 0.16 is satisfied, the reflectance of the red pixel portion of the electronic paper using the color filter substrate is smaller than the reflectance of the green pixel portion, and the reflectance of the red pixel portion is the reflectance of the blue pixel portion. White display method to make it smaller.

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