JP2009151245A - Liquid crystal display and color filter used for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display obtaining a luminous red chromaticity having deepness even though a white LED is adopted for a backlight, and to provide a color filter having red color reproducibility matched with the backlight and provided with a red pixel having a satisfactory pattern shape. <P>SOLUTION: The liquid crystal display includes: the backlight provided with a white LED device in which a blue LED, a red color emitting fluorescent body and a green color emitting fluorescent body are combined; and the color filter provided with colored pixels of a plurality of colors including the red pixel on a transparent substrate, wherein the light emitting spectrum of the white LED device has first, second and third peak wavelengths, the red pixel is formed of a cured product of a red photosensitive coloring composition containing 0.1 to 20 wt.% multifunctional thiol based on the total solid content of the red photosensitive coloring composition and the red chromaticity of the liquid crystal display is in the range formed by connecting four points in a chromaticity coordinates xy. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a liquid crystal display device, and in particular, a white LED combining a blue LED and a red light emitting phosphor / green light emitting phosphor is used as a backlight, and a color material excellent in red reproducibility matching the backlight. The present invention provides a liquid crystal display device excellent in red reproducibility using a color filter having a red colored layer using, and a color filter used therefor. The present invention is particularly preferably used for an in-vehicle liquid crystal display device.

  Currently, in-vehicle liquid crystal display devices are rapidly spreading mainly in car navigation devices and rear seat monitors. In addition, in recent years, there has been a movement to mount a liquid crystal display device on an instrument panel, and by adding a liquid crystal, it is possible to provide added value different from that of a conventional analog meter.

  In a conventional in-vehicle liquid crystal display device, a cold cathode fluorescent tube (CCFL) as used in a conventional liquid crystal device is used as a backlight for both a car navigation device and a rear seat monitor. However, the cold cathode fluorescent tube has problems such as poor responsiveness, weakness against vibration and shock, and poor environmental resistance because it contains mercury.

In addition, the ELV (End of Life vehicles directive) was enforced in the European Union (EU) in October 2000 for automotive parts, and passenger cars, buses, trucks, etc. registered in the EU market by this regulation in 2003 After July 1, Pb and Hg,
It was enacted to reduce Cr ⁶⁺ usage to 1000 ppm or less and Cd usage to 100 ppm or less. This aims to promote the use, recycling, and regeneration of waste from scrap cars.

  In-vehicle displays are also subject to this regulation, and instead of conventional cold cathode fluorescent tubes containing mercury, replacement with LEDs (light-emitting diodes) that are mercury-free is progressing.

  As LED backlight unit, three-wavelength white LED using three-color LED light source of red, green and blue, and light emitted from blue LED are passed through phosphor such as YAG (yttrium, aluminum, garnet). There are mixed white LEDs and the like, and among them, white LEDs are widely used in mobile-related small liquid crystal display devices in recent years.

  At present, because of the individual differences and price of backlight LEDs, the three-color LED has little cost merit, so pseudo-white LEDs are the mainstream, and replacement of cold cathode fluorescent tubes for in-vehicle use should be replaced with white LEDs. Is predicted.

However, when a white LED is used for the backlight, the white LED does not have a light emission peak in the long wavelength region, so that there is a problem that the color reproducibility of the red display of the liquid crystal display device is remarkably deteriorated. In other words, there is a problem that the brightness of red is insufficient or a dark orange display is unsuitable as a warning color. On the other hand, the reproducibility of red color is very important for in-vehicle use displays such as warning display. There is a strong demand for deep red reproducibility particularly in an in-vehicle liquid crystal display device that is an environmentally friendly mercury-free backlight and simultaneously uses a cost-effective LED light source for the backlight.
JP 2007-477181 A

  The present invention solves the above-mentioned problems, a liquid crystal display device that can obtain a bright and deep red chromaticity while adopting a white LED for the backlight, and a red reproduction that matches the backlight. An object of the present invention is to provide a color filter having red pixels with good pattern shape.

  In order to solve the above problems, a first aspect of the present invention is a backlight including a white LED device in which a blue LED, a red light emitting phosphor and a green light emitting phosphor are combined, and a plurality of red pixels on a transparent substrate. A liquid crystal display device comprising a color filter provided with a colored pixel, wherein the emission spectrum of the white LED device has a first peak wavelength of 440 nm to 470 nm, a second peak wavelength of 510 nm to 550 nm, and 630 nm. Red photosensitive coloring having a third peak wavelength of 670 nm or less and the red pixel containing 0.1% by weight or more and 20% by weight or less of polyfunctional thiol with respect to the total solid content of the red photosensitive coloring composition The red chromaticity of the liquid crystal display device formed of a cured product of the composition has the following four points (0.620, 0.280), ( .620,0.300), to provide a liquid crystal display device which is characterized in that in the chromaticity range connecting (0.680,0.315), and (0.680,0.280).

  The red pixel of the color filter has an organic pigment CI. Of 80% or more of the total organic pigment of solid content. It can be formed from a cured product of a red photosensitive coloring composition containing pigment number PR177.

  The following can be used for the phosphor used in the white LED device relating to the liquid crystal display device of the present invention.

  The red light-emitting phosphor is a nitride phosphor that is activated by Eu and contains a group II element M, Si, Al, B, and N, and absorbs ultraviolet light or blue light and emits red light. A red light-emitting phosphor represented by the following general formula (I).

^{_{M 1 w Al x Si y B}} z N ((2/3) w + x + (4/3) y + z): Eu 2+ (I)
(In the formula, M ¹ is at least one selected from the group consisting of Mg, Ca, Sr, and Ba, and w, x, y, and z are 0.056 ≦ w ≦ 9, x = 1,. (056 ≦ y ≦ 18, 0 ≦ z ≦ 0.5)
The green light emitting phosphor is a phosphor represented by the following general formula (II).

^{_{Ba 5-x-y Eu x}} M 2 y Si m O 5 + 2m (II)
(In the formula, M ² is at least one of Ca and Sr, and x, y, and m are 0.0001 ≦ x ≦ 0.3, 0 ≦ y ≦ 0.8, 2.5 <m <3. 5)
The green light emitting phosphor is a phosphor represented by the following general formula (III).

(M ³ _1-y R _y ) _a MgM ⁴ _b M ⁵ _c O _{a + 2b + (3/2) c} X ₂ (III)
(Wherein M ³ is at least one selected from the group consisting of Ca, Sr, Ba, Zn, and Mn, M ⁴ is at least one selected from the group consisting of Si, Ge, and Sn, and M ⁵ is B , Al, Ga, and In, at least one selected from the group consisting of In, X is at least one selected from the group consisting of F, Cl, Br, and I, and R must be Eu selected from rare earth elements At least one, y, a, b and c are 0.0001 ≦ y ≦ 0.3, 7.0 ≦ a <10.0, 3.0 ≦ b <5.0, 0 ≦ c <1 .0.)
The green light emitting phosphor is a phosphor represented by the following general formula (IV) or (V).

^{_{L X M 6 Y O Z N}} ((2/3) X + (4/3) Y- (2/3) Z): R (IV)
Or ^{_{L X M 6 Y Q T O}} Z N ((2/3) X + (4/3) Y + T- (2/3) Z): R (V)
(Wherein L is at least one group II element selected from the group consisting of Be, Mg, Ca, Sr, Ba, and Zn, and M ⁶ is C, Si, Ge, Sn, Ti, At least one Group IV element selected from the group consisting of Zr and Hf, R is a rare earth element, and X, Y, T, and Z are 0.5 <X <1.5; (5 <Y <2.5, 0 <T <0.5, 1.5 <Z <2.5.)
Moreover, what is represented by the following general formula (V) can be used as said green light emission fluorescent substance.

(M ⁷ _1-X Eu _X ) ₂ Si _{Y 2} O _{+ 2} (V)
(Wherein M ⁷ is at least one group II element selected from the group consisting of Be, Mg, Ca, Sr, Ba, and Zn, and X and Y are 0.001 ≦ X ≦ 0.2, 0.9 ≦ Y ≦ 1.1.)
According to a second aspect of the present invention, there is provided a color filter comprising a plurality of colored pixels including a red pixel on a transparent substrate and being used in the above liquid crystal display device.

  According to the present invention, a white LED that combines a blue LED, a red light emitting phosphor, and a green light emitting phosphor is used as a backlight, and a warning color display is provided by using a color filter having red reproducibility matched with the backlight. A liquid crystal display device suitable for the above can be obtained. In addition, a liquid crystal display device using a color filter having a deep red color reproducibility can be obtained. Furthermore, since the backlight is a white LED that combines a mercury-free blue LED excellent in environmental friendliness and a phosphor, it is possible to promote waste use, recycling, and regeneration of the liquid crystal display device.

  Hereinafter, embodiments of the present invention will be described in detail.

  The liquid crystal display device according to the first embodiment of the present invention uses, as a backlight, a white LED device in which a blue LED, a red light emitting phosphor, and a green light emitting phosphor are combined and mixed, and a red color used for a red pixel. 80% or more of the total organic pigment in the solid content of the photosensitive coloring composition is PR177. The red chromaticity of such a liquid crystal display device has a first peak wavelength of 440 nm to 470 nm, a second peak wavelength of 510 nm to 550 nm, and a third peak wavelength of 630 nm to 670 nm.

  The white LED device used in this embodiment has an emission spectrum characteristic as shown in FIG. 1, and this emission spectrum characteristic is a cold cathode fluorescent tube (used in the conventional liquid crystal display device shown in FIG. CCFL) and the emission spectrum characteristics of white LEDs in which light emitted from a blue LED shown in FIG. 3 is mixed through a phosphor such as YAG (yttrium, aluminum, garnet).

  CCFLs are being replaced as a response to the environment. White LEDs, which are a mixture of blue LEDs having the emission characteristics shown in FIG. 3 and yellow light-emitting phosphors such as YAG, are mixed in the long wavelength range, unlike CCFLs. Since it does not have a peak, it is a two-wavelength light source, and when the color filter is the same as that used in the conventional CCFL, the red reproducibility is particularly degraded, and the original red display is orange. There was a problem of being perceived.

  In contrast, a white LED having a light emission characteristic as shown in FIG. 1 in which a blue LED, a red light emitting phosphor, and a green light emitting phosphor are mixed and mixed has a light emission peak of three wavelengths, and the blue LED, YAG, etc. Compared with a white LED mixed with a yellow light emitting phosphor, a red color reproducibility is greatly improved and a color filter substrate having a plurality of colors including a red colored layer excellent in red reproducibility is used. Further, a deep red display can be obtained.

  As described above, particularly in a liquid crystal display device for in-vehicle use, red reproducibility is important as a dangerous color display. Therefore, it is strongly desired that red and orange can be distinguished.

  Therefore, in the liquid crystal display device according to the present embodiment, a white LED in which a blue LED, a red light emitting phosphor, and a green light emitting phosphor are combined and mixed is used for the backlight, and a color material having excellent red reproducibility is used. By using a color filter having a red colored layer, the following four points (0.620, 0.280), (0.620, 0.300), (0.680, 0.315) and (0.680, 0.280), a deep red chromaticity within the chromaticity range can be realized, thus solving the above problem.

  The above red chromaticity range was evaluated by changing the pigment type and composition of the red coloring material forming the red colored layer, and when the color reproduction range was NTSC 50% to 95%, This is based on the knowledge that a chromaticity range is necessary.

  When the y value is larger than this range, it is perceived as vermilion to orange, and when the y value is smaller than this range, it is perceived as magenta.

  In addition, the color filter substrate used in the liquid crystal display device according to the present embodiment includes pixels of a plurality of colors including red on at least a transparent substrate, and these pixels of the plurality of colors mainly include an organic pigment and a transparent resin. The plurality of colors include a combination of red, green, blue (R, G, B), a combination of yellow, magenta, cyan (Y, M, C), or a combination obtained by adding orange. .

  The color filter substrate used in the present embodiment can be particularly preferably applied to a color filter having red pixels (that is, an RGB system). In addition to R, G, and B, the present invention can also be applied to a color filter that arranges Y, M, and C on the same substrate.

  Further, the color filter substrate used in the present embodiment, when combined with a white LED, has the following four points (0.620, 0.280), (0.620, 0.300) in the xy chromaticity coordinate system, A deep red chromaticity within a range connecting (0.680, 0.315) and (0.680, 0.280) is realized. Therefore, the pigment characteristic in the red photosensitive coloring composition used for forming the red colored layer necessary for that purpose is that of the total organic pigment in the solid content of the red photosensitive coloring composition.

  When the pigment ratio of PR177 is 80% or more, a bright and deep red color can be reproduced in a liquid crystal display device using a white LED as a backlight. However, the higher the content ratio of PR177 in the red photosensitive coloring composition used for forming the red colored layer of the color filter substrate, the more the absorption wavelength region of the curing system component (initiator) is inhibited, and the color filter manufacturing process. Can cause difficult problems.

  When the pigment ratio of PR177 is 80% or more, the tendency of the red pixel to peel off becomes strong.

  That is, there is a problem that the taper shape of the cross section of the red pixel cannot be maintained in the development process after the exposure process which is the main process of photolithography. There is a case in which the substrate surface side dimension of the red pixel formed on the transparent substrate is small (reverse taper), and the red pixel is easily peeled off in the development process.

  Thus, in order to solve the problem which arises newly, the color filter which concerns on this embodiment contains 0.1 to 20 weight% of polyfunctional thiol with respect to the total solid of a red photosensitive coloring composition. It is desirable. When the polyfunctional thiol content is less than 0.1% by weight, the effect of addition is insufficient, and the cross-sectional shape at the time of forming the colored layer is reverse paper. Moreover, when it adds exceeding 20 weight%, an effect will become excessive, a sensitivity will become high and the resolution will fall.

  The polyfunctional thiol that can be used in the present embodiment may be a compound containing two or more thiol groups, such as hexanedithiol, decanedithiol, 1,4-butanediol bisthiopropionate, 1,4- Butanediol bisthioglycolate, ethylene glycol bisthioglycolate, ethylene glycol bisthiopropionate, trimethylolpropane tristhioglycolate, trimethylolpropane tristhiopropionate, trimethylolpropane tris (3-mercaptobutyrate) , Pentaerythritol tetrakisthioglycolate, pentaerythritol tetrakisthiopropionate, tris (2-hydroxyethyl) isocyanurate trimercaptopropionate, 1,4-dimethylmercaptobenzene, 2, 4, - trimercapto -s- triazine, 2- (N, N- dibutylamino) -4,6-dimercapto -s- triazine. Such polyfunctional thiol can be used individually by 1 type or in mixture of 2 or more types.

  Further, the color filter used in the present embodiment has the following four points (0.620, 0.280), (0.620, 0.300), (0.680, 0) in the xy chromaticity coordinate system in red display. .315) and (0.680, 0.280), within a range in which chromaticity can be realized, the red photosensitive coloring composition used for forming the red colored layer includes a red pigment such as PR254, C.I. L. Yellow pigments such as pigment numbers PY150, PY139, PY138, PY185, and PY13 may also be included.

  Hereinafter, the color filter used in the liquid crystal display device according to the present embodiment will be described in more detail.

  The transparent substrate used for the color filter preferably has a certain transmittance with respect to visible light, and more preferably has a transmittance of 80% or more. In general, it may be one used in a liquid crystal display device, and examples thereof include a plastic substrate such as PET and glass, but a glass substrate is usually preferable. In the case of using a light shielding pattern, a pattern in which a metal thin film such as chromium or a light shielding resin is previously formed on a transparent substrate by a known method may be used.

  The pixel may be formed on the transparent substrate by any known method such as an inkjet method, a printing method, a photoresist method, or an etching method. However, in consideration of high definition, controllability and reproducibility of spectral characteristics, the photoresist method is preferable. In the photoresist method, a colored layer in which a pigment is dispersed in a transparent resin together with a photoinitiator and a polymerizable monomer in an appropriate solvent is coated on a transparent substrate to form a colored layer. Is subjected to pattern exposure and development to form one color pixel, and these steps are repeated for each color to produce a color filter.

  When forming the colored layer which comprises the pixel of a color filter by the photolithographic method, the following method is followed, for example. A pigment serving as a colorant is dispersed in a transparent resin, and then mixed with an appropriate solvent together with a photoinitiator and a polymerizable monomer. There are various methods such as a mill base, three rolls, and a jet mill as a method for dispersing the pigment as the colorant and the transparent resin, but the method is not particularly limited thereto.

  Specific examples of organic pigments that can be used for the coloring composition forming the pixels of the color filter are shown below by color index numbers. Examples of red pigments include C.I. I. In addition to Pigment Red 254 and PR177, C.I. I. Pigment Red 7, 9, 14, 41, 48: 1, 48: 2, 48: 3, 48: 4, 81: 1, 81: 2, 81: 3, 97, 122, 123, 146, 149, 168, 177, 178, 179, 180, 184, 185, 187, 192, 200, 202, 208, 210, 215, 216, 217, 220, 223, 224, 226, 227, 228, 240, 246, 255, 264, 272, 279 and the like.

  Examples of yellow pigments include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 20, 24, 31, 32, 34, 35, 35: 1, 36, 36: 1, 37, 37: 1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 86, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123, 125, 126, 127, 128, 129, 137, 138, 139, 144, 146, 147, 148, 150, 151, 152, 153, 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 171, 172, 1 3,174,175,176,177,179,180,181,182,185,187,188,193,194,199,213,214, and the like.

  Examples of orange pigments include C.I. I. Pigment Orange 36, 43, 51, 55, 59, 61, 71, 73 and the like.

  Examples of green pigments include C.I. I. Pigment Green 7, 10, 36, 37 and the like.

  Examples of blue pigments include C.I. I. Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64, 80 and the like.

  Examples of purple pigments include C.I. I. Pigment Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, 50 and the like.

  The above pigments can be used alone or in combination of two or more depending on the pixel.

  In combination with the organic pigment, an inorganic pigment may be used in combination in order to ensure good coatability, sensitivity, developability and the like while balancing saturation and lightness. Inorganic pigments include yellow lead, zinc yellow, red pepper (red iron oxide (III)), cadmium red, ultramarine, bitumen, chromium oxide green, cobalt green, and other metal oxide powders, metal sulfide powders, metal powders, etc. Can be mentioned. Furthermore, for color matching, a dye can be contained within a range that does not lower the heat resistance.

  The transparent resin used for the coloring composition is a resin having a transmittance of preferably 80% or more, more preferably 95% or more in the entire wavelength region of 400 to 700 nm in the visible light region. The transparent resin includes a thermoplastic resin, a thermosetting resin, and a photosensitive resin. If necessary, the transparent resin can be used alone or in admixture of two or more monomers or oligomers that are precursors thereof that are cured by irradiation with radiation to produce a transparent resin.

  Examples of the thermoplastic resin include butyral resin, styrene-maleic acid copolymer, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyurethane resin, and polyester resin. , Acrylic resins, alkyd resins, polystyrene, polyamide resins, rubber resins, cyclized rubber resins, celluloses, polyethylene, polybutadiene, polyimide resins, and the like. Examples of the thermosetting resin include epoxy resins, benzoguanamine resins, rosin-modified maleic acid resins, rosin-modified fumaric acid resins, melamine resins, urea resins, and phenol resins.

  Examples of the photosensitive resin include (meth) acrylic compounds having a reactive substituent such as an isocyanate group, an aldehyde group, and an epoxy group on a linear polymer having a reactive substituent such as a hydroxyl group, a carboxyl group, or an amino group, A resin obtained by reacting an acid and introducing a photocrosslinkable group such as a (meth) acryloyl group or a styryl group into the linear polymer is used. In addition, linear polymers containing acid anhydrides such as styrene-maleic anhydride copolymer and α-olefin-maleic anhydride copolymer can be obtained from (meth) acrylic compounds having hydroxyl groups such as hydroxyalkyl (meth) acrylate. Half-esterified products are also used.

  Examples of polymerizable monomers that can be used as a photocrosslinking agent include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and ethylene oxide-modified trimethylolpropane tri (meth). Representative examples include various acrylic esters and methacrylic esters such as acrylate and propylene oxide-modified trimethylolpropane tri (meth) acrylate.

  These can be used alone or in admixture of two or more. Further, for the purpose of keeping the photocurability properly, other polymerizable monomers and oligomers can be mixed and used as necessary.

  Other polymerizable monomers and oligomers include methyl (meth) acrylate, ethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, β-carboxyethyl (Meth) acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, triethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate , Pentaerythritol tri (meth) acrylate, 1,6-hexanediol diglycidyl ether di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate , Neopentyl glycol diglycidyl ether di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecanyl (meth) acrylate, ester acrylate, (meth) acrylic acid ester of methylolated melamine, epoxy (meth) acrylate , Various acrylates and methacrylates such as urethane acrylate, (meth) acrylic acid, styrene, vinyl acetate, hydroxyethyl vinyl ether, ethylene glycol divinyl ether, pentaerythritol trivinyl ether, (meth) acrylamide, N-hydroxymethyl (meth) ) Acrylamide, N-vinylformamide, acrylonitrile and the like.

  Also about these, it can use individually or in mixture of 2 or more types.

When the colored composition is cured by ultraviolet irradiation, a photopolymerization initiator or the like is added to the colored composition. As photopolymerization initiators, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- Acetophenone compounds such as hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl Benzoin compounds such as dimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3 Benzophenone compounds such as 3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, 2,4- Thioxanthone compounds such as diethylthioxanthone, 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) -4,6 -Bis (trichloromethyl) -s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2-piperonyl-4,6-bis (trichloromethyl) -s-triazine 2,4-bis (trichloromethyl) -6-styryl-s-triazine, 2- (naphth-1-yl) -4,6-bis (trichloro) Methyl) -s-triazine, 2- (4-methoxy-naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, Triazine compounds such as 2,4-trichloromethyl (4′-methoxystyryl) -6-triazine, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], Oxime ester compounds such as O- (acetyl) -N- (1-phenyl-2-oxo-2- (4′-methoxy-naphthyl) ethylidene) hydroxylamine, bis (2,4,6-trimethylbenzoyl) phenyl Phosphine compounds such as phosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 9,10-phenanthrenequinone, camphorquinone, ethyl anthraquino Quinone compounds such as borate compounds, carbazole compounds, imidazole compounds, titanocene compounds and the like.

  These photopolymerization initiators can be used alone or in combination of two or more. The amount of the photopolymerization initiator used is preferably 0.5 to 50% by mass, more preferably 3 to 30% by mass, based on the total solid content of the colored composition.

  Further, as sensitizers, triethanolamine, methyldiethanolamine, triisopropanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 2-dimethylaminoethyl benzoate, 2-Ethylhexyl 4-dimethylaminobenzoate, N, N-dimethylparatoluidine, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, 4,4′-bis (ethylmethyl) Amine-based compounds such as amino) benzophenone can also be used in combination.

  These sensitizers can be used alone or in combination of two or more. The amount of the sensitizer used is preferably 0.5 to 60% by mass, more preferably 3 to 40% by mass based on the total amount of the photopolymerization initiator and the sensitizer.

  Moreover, as needed, as a thermal crosslinking agent, a melamine resin, an epoxy resin, etc. are mentioned, for example. Examples of the melamine resin include alkylated melamine resins (methylated melamine resin, butylated melamine resin, etc.), mixed etherified melamine resins, and the like, which may be a high condensation type or a low condensation type. Examples of the epoxy resin include glycerol / polyglycidyl ether, trimethylolpropane / polyglycidyl ether, resorcin / diglycidyl ether, neopentyl glycol / diglycidyl ether, 1,6-hexanediol / diglycidyl ether, ethylene glycol (polyethylene). Glycol) and diglycidyl ether.

  Any of these may be used alone or in admixture of two or more.

  The coloring composition can contain an organic solvent as necessary. Examples of the organic solvent include cyclohexanone, ethyl cellosolve acetate, butyl cellosolve acetate, 1-methoxy-2-propyl acetate, diethylene glycol dimethyl ether, ethylbenzene, ethylene glycol diethyl ether, xylene, ethyl cellosolve, methyl-n amyl ketone, propylene glycol monomethyl ether toluene, Examples include methyl ethyl ketone, ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone, petroleum solvent, and the like. These can be used alone or in combination.

  In manufacturing a color filter substrate used in the liquid crystal display device according to the present embodiment, first, a photosensitive coloring composition containing the above-described components is applied on a transparent substrate and prebaked. Spin coating, dip coating, die coating and the like are usually used as the means for coating, but the coating means is not limited to these as long as it can be coated with a uniform film thickness on a substrate of about 40 to 60 cm square. Prebaking is preferably performed at 50 to 120 ° C. for about 10 to 20 minutes. The coating film thickness is arbitrary, but considering the spectral transmittance and the like, the film thickness after pre-baking is usually about 2 μm.

  Thus, exposure is performed through a pattern mask with respect to the board | substrate which apply | coated the photosensitive coloring composition and formed the colored layer. A normal high-pressure mercury lamp or the like may be used as the light source.

  Subsequently, development is performed on the exposed colored layer. An alkaline aqueous solution is used as the developer. Examples of the alkaline aqueous solution include a sodium carbonate aqueous solution, a sodium hydrogen carbonate aqueous solution, a mixed aqueous solution of the two, or a mixture obtained by adding an appropriate surfactant to them.

  After developing, it is washed with water and dried to obtain a pixel of any one color.

  By repeating the above-described series of steps by changing the photosensitive coloring composition and pattern and repeating the necessary number of colors, a colored pattern in which the necessary number of colors are combined, that is, a color filter including a plurality of color pixels can be obtained. it can.

  The red light-emitting phosphor and the green light-emitting phosphor used for producing a white LED device as a backlight constituting a liquid crystal display device in combination with the color filter substrate exhibiting the above excellent characteristics will be described in detail below. .

(Red light emitting phosphor)
The red light-emitting phosphor is a nitride phosphor represented by the following general formula (I) that is activated by Eu and includes a group II element M ¹ , Si, Al, B, and N. A material that absorbs light and emits red light can be preferably used.

^{_{M 1 w Al x Si y B}} z N ((2/3) w + x + (4/3) y + z): Eu 2+ (I)
In the above formula (I), M ¹ is at least one selected from the group consisting of Mg, Ca, Sr, and Ba, and w, x, y, and z are preferably 0.056 ≦ w ≦ 9, x = 1, 0.056 ≦ y ≦ 18, 0.0005 ≦ z ≦ 0.5, more preferably 0.04 ≦ w ≦ 3, x = 1, 0.143 ≦ y ≦ 8.7, 0 ≦ z ≦ 0.5, most preferably 0.05 ≦ w ≦ 3, x = 1, 0.167 ≦ y ≦ 8.7, and 0.0005 ≦ z ≦ 0.5.

  Further, z is preferably 0.5 or less, more preferably 0.3 or less, and desirably 0.0005 or more. More preferably, the molar concentration of boron is set to 0.001 or more and 0.2 or less.

  Such a nitride phosphor is activated by Eu, but a part of Eu is Sc, Tm, Yb, Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Substitution with at least one rare earth element selected from the group consisting of Lu is also possible.

Preferred nitride phosphors include those represented by the general formula M ¹ _1-z AlSiB _z N _{((2/3) (1-z) + (7/3) + z)} : Eu ²⁺ . In the formula, M ¹ is at least one selected from the group consisting of Mg, Ca, Sr, and Ba, the range of x is 0.001 ≦ x ≦ 0.3, and the range of z is 0 ≦ z ≦. 0.5.

Another preferred nitride phosphor is represented by the general formula M ¹ _w AlSiB _z N _{((2/3) w + (7/3) + z)} : Eu ²⁺ . In the formula, M ¹ is at least one selected from the group consisting of Mg, Ca, Sr, and Ba, and the ranges of w and z are 0.04 ≦ w ≦ 3 and 0 ≦ z ≦ 0.5. .

When using a Ca as M ^1, Ca is preferably used alone. However, a part of Ca can be replaced by Sr, Mg, Ba, Sr and Ba, or the like. By replacing a part of Ca with Sr, the peak of the emission wavelength of the nitride phosphor can be adjusted.

  Si is also preferably used alone, but a part of it can be substituted with Group IV elements C and Ge. In the case where only Si is used, a nitride phosphor that is inexpensive and has good crystallinity can be obtained.

  Eu as an activator is preferably used alone, but a part of Eu is Sc, Tm, Yb, Y, La, Ce, PR, Nd, Sm, Gd, Tb, Dy, Ho, Er, You may substitute by Lu. When a part of Eu is substituted with another element, the other element acts as a co-activator. By doing so, the color tone can be changed, and the light emission characteristics can be adjusted.

When using a mixture in which Eu is essential, the blending ratio can be changed as desired. Europium mainly has bivalent and trivalent energy levels, but the nitride phosphor used in the present embodiment uses Eu ²⁺ as an activator with respect to the base Ca. Eu ²⁺ is easily oxidized and is commercially available with a trivalent Eu ₂ O ₃ composition. However, in commercially available Eu ₂ O ₃ , O is greatly involved and it is difficult to obtain a good phosphor. Therefore, it is preferable to use a material obtained by removing O from Eu ₂ O ₃ out of the system. For example, it is preferable to use europium alone or europium nitride.

  The nitride phosphor further includes a group I element composed of Cu, Ag, Au, a group III element composed of Ga, In, a group IV element composed of Ti, Zr, Hf, Sn, Pb, P, Sb, 1-500 ppm or less of at least 1 sort (s) of elements chosen from the group V element which consists of Bi, and the group VI element which consists of S can also be included. The luminous efficiency can be adjusted by adding these elements.

In the nitride phosphor, Fe, Ni, Cr, Ti, Nb, molar concentration of Sm and Yb is preferably 0.01 or less with respect to the molar concentration of ^{M 1.} This is because when a large amount of Fe, Ni, Cr, Ti, Nb, Sm, and Yb is contained, the light emission luminance is lowered.

  The elements to be added to the above-described nitride phosphor are usually added as oxides or oxide hydroxides, but are not limited thereto, and are not limited to metals, nitrides, imides, amides, or other inorganic substances. A salt may be sufficient and the state previously contained in the other raw material may be sufficient.

  Oxygen is contained in the composition of the nitride phosphor. It is conceivable that oxygen is introduced from various oxides as raw materials, or oxygen is mixed during firing. This oxygen is considered to promote the effects of Eu diffusion, grain growth, and crystallinity improvement. That is, even if one compound used as a raw material is replaced with metal, nitride, or oxide, the same effect can be obtained, but rather the effect when using an oxide may be great.

(Green light emitting phosphor 1)
Examples of the green light emitting phosphor include those represented by the following general formula (II).

^{_{Ba 5-x-y Eu x}} M 2 y Si m O 5 + 2m (II)
(In the formula, M ² is at least one of Ca and Sr, and x, y, and m are 0.0001 ≦ x ≦ 0.3, 0 ≦ y ≦ 0.8, 2.5 <m <3. 5)
This silicate phosphor has low excitation efficiency with light having a wavelength longer than about 485 nm. Therefore, the light is efficiently excited by light on the short wavelength side of 485 nm or less. Among them, it is excited with high efficiency especially by light on the short wavelength side of 460 nm or less.

  When the silicate phosphor is excited, light having an emission peak wavelength in the region from 495 nm to 584 nm is emitted. The emission peak wavelength of the silicate phosphor can be changed by variously changing the composition of the phosphor and changing the excitation wavelength.

  In the composition of the silicate phosphor, x, y, m are in the range of 0.0001 ≦ x ≦ 0.3, 0 ≦ y ≦ 0.8, and 2.5 <m <3.5. A high-luminance phosphor having an emission peak wavelength from 495 nm to 584 nm and emitting light from green to yellow is obtained. Among these, x is more preferably in the range of 0.1 ≦ x ≦ 0.5. This is because higher luminance can be achieved by setting this range. Further, m is preferably in the range of 2.5 <m ≦ 3.2. This is because higher luminance can be achieved by setting this range. Note that phosphors having various color tones can be obtained by changing y.

(Green light emitting phosphor 2)
Examples of the green light emitting phosphor include those represented by the following general formula (III).

(M ³ _1-y R _y ) _a MgM ⁴ _b M ⁵ _c O _{a + 2b + (3/2) c} X ₂ (III)
(Wherein M ³ is at least one selected from the group consisting of Ca, Sr, Ba, Zn, and Mn, M ⁴ is at least one selected from the group consisting of Si, Ge, and Sn, and M ⁵ is B , Al, Ga, and In, at least one selected from the group consisting of In, X is at least one selected from the group consisting of F, Cl, Br, and I, and R must be Eu selected from rare earth elements And y, a, b and c are 0.0001 ≦ y ≦ 0.3, 7.0 ≦ a <10.0, 3.0 ≦ b <5.0, 0 ≦ c <. 1.0.)
This phosphor contains at least one element selected from the group consisting of Ca, Sr, Ba, Zn, and Mn, more preferably Ca. When Ca is contained, a part of Ca may be substituted with Mn, Sr, or Ba.

  This phosphor contains at least one element selected from the group consisting of Si, Ge, and Sn, more preferably Si. When Si is included, a part of Si may be substituted with Ge or Sn.

  The phosphor includes at least one element selected from the group consisting of F, Cl, Br, and I, more preferably Cl. When Cl is contained, a part of Cl may be substituted with F, Br, or I.

  This phosphor contains at least one rare earth element which essentially requires Eu. Rare earth is a collective term for a total of 17 elements of scandium, yttrium, and lanthanoid elements, of which Eu is most preferred. What substituted a part of Eu with Ce, Pr, Nd, Sm, Tb, Dy, Ho, Er, Tm, and Yb may be used. More preferably, Eu may be partially substituted with Ce, PR, Nd, Sm, Tb, Dy, Ho, Tm.

If it becomes the said composition, a raw material will not be specifically limited. For example, a simple substance, an oxide, carbonate or nitride can be used. Specifically, M ³ CO ₃ , M ³ O, M ³ , MgO, MgCO ₃ , Mg, M ⁴ (CO ₃ ) ₂ , M ⁴ O ₂ , M ⁴ , M ⁵ ₂ (CO ₃ ) ₃ M ⁵ ₂ O ₃ , M ⁵ , M ³ X ₂ , HX, X _{2 and the} like can be used.

  The green phosphor represented by the general formula (III) has an emission peak wavelength in a wavelength range from a green region of 495 nm to 584 nm to a yellow region. For example, in the case of having an element of Ca, Eu, Mg, Si, O, Cl, in the vicinity of 500 nm to 520 nm, in the case of having an element of Ca, Mn, Eu, Mg, Si, O, Cl, in the vicinity of 530 nm to 570 nm, Some have an emission peak wavelength. However, this emission peak wavelength varies depending on the amount and composition of elements contained.

(Green light emitting phosphor 3)
Examples of the green light emitting phosphor include those represented by the following general formula (IV).

^{_{L X M 6 Y O Z N}} ((2/3) X + (4/3) Y- (2/3) Z): R (IV)
Or ^{_{L X M 6 Y Q T O}} Z N ((2/3) X + (4/3) Y + T- (2/3) Z): R (V)
(Wherein L is at least one group II element selected from the group consisting of Be, Mg, Ca, Sr, Ba, and Zn, and M ⁶ is C, Si, Ge, Sn, Ti, At least one group IV element selected from the group consisting of Zr and Hf, and Q is at least one group III element selected from the group consisting of B, Al, Ga, and In; Is a rare earth element, and X, Y, T, and Z are 0.5 <X <1.5, 1.5 <Y <2.5, 0 <T <0.5, 1.5 <Z <. 2.5.)
The oxynitride phosphor represented by the general formula (IV) or (V) is configured to include a crystal in which elements are arranged at least in part according to a certain rule, and the high luminance is efficiently generated from the crystal. Light is emitted. In the above general formula, by setting 0.5 <X <1.5, 1.5 <Y <2.5, 0 <T <0.5, 1.5 <Z <2.5, the light emitting part The crystal phase can be formed relatively easily, and the phosphor having high luminous efficiency and high luminance can be obtained.

  In addition, when it is desired to set the ratio of the crystals contained for the purpose of adjusting the emission luminance to a desired value, the adjustment can be made by the values of X, Y, and Z in the general formula (IV). However, the said range is a preferable range, and this invention is not limited to the said range.

  In addition, this green phosphor can change the ratio of O and N. Further, the molar ratio of the cation and the anion represented by (L + M) / (O + N) can be changed, whereby the emission spectrum and intensity can be finely adjusted. This can be achieved, for example, by desorbing N or O by a process such as vacuum, and the present invention is not limited to this method.

  In the composition of this phosphor, at least one or more of Li, Na, K, Rb, Cs, Mn, Re, Cu, Ag, and Au may be contained, and by adding these, luminance, Luminous efficiency such as quantum efficiency can be adjusted. Further, other elements may be contained to such an extent that the characteristics are not impaired.

  Part of the Group II element contained in this phosphor is replaced with the activator R. The amount of the activator R with respect to the mixed amount of the Group II element and the activator R is (mixed amount of the Group II element and the activator R) :( amount of the activator R) = 1: 0. A molar ratio of 0.001 to 1: 0.8 is preferred.

  L is at least one Group II element selected from the group consisting of Be, Mg, Ca, Sr, Ba, and Zn. L may be a simple substance such as Ca and Sr, but may be a combination of a plurality of elements such as Ca and Sr, Ca and Ba, Sr and Ba, and Ca and Mg. When L is a combination of a plurality of elements, the composition ratio can be changed. In particular, L is preferably a Group II element that is at least one of Ca, Sr, and Ba selected from the group consisting of Mg, Ca, Sr, Ba, and Zn.

M ⁶ is a Group IV element that is at least one selected from the group consisting of C, Si, Ge, Sn, Ti, Zr, and Hf. M ⁶ may be a simple substance such as Si or Ge, or may be a combination of a plurality of elements such as Si and C. In the present invention, the above-mentioned group IV elements can be used, but it is particularly preferable to use Si or Ge. By using Si or Ge, an inexpensive phosphor with good crystallinity can be provided. In particular, M ⁶ is preferably a Group IV element that is at least one element that essentially includes Si selected from the group consisting of C, Si, Ge, Sn, Ti, and Hf.

  Q is a Group III element that is at least one selected from the group consisting of B, Al, Ga, and In.

Metal, oxide, imide, amide, nitride, various salts, and the like can be used for L, M ⁶ , and Q as the main component of the phosphor base material.

  R is a rare earth element. Specifically, R is one or more elements selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. In the present invention, among these rare earth elements, Eu is preferably used. Further, Eu and one or more rare earth elements may be included. In that case, it is preferable that Eu is contained as R in an amount of 50% by mass or more, more preferably 70% or more. That is, the activator R is at least one selected from the group consisting of La, Ce, PR, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, essential to Eu. It is preferable that it is a rare earth element. Elements other than Eu act as a co-activator.

(Green light emitting phosphor 4)
Examples of the green light emitting phosphor include those represented by the following general formula (VI).

(M ⁷ _1-X Eu _X ) ₂ Si _{Y 2} O _{+ 2} (VI)
(In the formula, M ⁷ is at least one group II element selected from the group consisting of Be, Mg, Ca, Sr, Ba, and Zn. X and Y are 0.001 ≦ X ≦ 0. 2, 0.9 ≦ Y ≦ 1.1.)
This silicate phosphor has low excitation efficiency with light having a wavelength longer than about 490 nm. Therefore, the light is efficiently excited by light on the short wavelength side of 490 nm or less. Among them, it is excited with high efficiency especially by light on the short wavelength side of 460 nm or less.

  When this silicate phosphor is excited, it has an emission peak wavelength in the region of 490 nm to 580 nm. The emission peak wavelength of the silicate phosphor can be changed by variously changing the composition of the silicate phosphor and changing the excitation wavelength.

The x and y in the composition of the silicate phosphor are preferably in the range of 0.001 ≦ X ≦ 0.2 and 0.9 ≦ Y ≦ 1.1. In this range, the phosphor has a light emission peak wavelength from 490 nm to 580 nm, and becomes a high-luminance phosphor that emits light from green to yellow. Among these, 0.005 ≦ x ≦ 0.1 is preferable. This is because higher luminance can be achieved by setting this range. It is possible to provide a phosphor having a different color tone by changing the M ^7.

  A white LED or a blue LED and a red light emitting phosphor used for a yellow light emitting phosphor and a red light emitting phosphor mixed with a combination of a blue LED, a red light emitting phosphor and a green light emitting phosphor of a backlight for a liquid crystal display device of the present invention And the manufacturing method of green light-emitting fluorescent substance is explained in full detail.

(Green light-emitting phosphor 5)
Examples of the green light emitting phosphor include those represented by the following general formula (VII).

^{_{M 8 X A Y X Z (}} VII)
(Wherein M ⁸ is at least one element selected from the group consisting of Mn, Ce, Eu, and A is selected from the group consisting of C, Si, Ge, Sn, B, Al, Ga, In) At least one element selected from the group consisting of O and N, and X, Y, and Z are 0.00001 ≦ X ≦ 0.1, 0.38 ≦ Y ≦ 0.46, 0.54 ≦ Z ≦ 0.62 and X + Y + Z = 1.)
This phosphor contains a solid solution of a nitride or oxynitride crystal phase having a β-type Si ₃ N ₄ crystal structure as a main component, has a high emission intensity in a wavelength range of 500 nm to 600 nm, and has a green color. Excellent as a phosphor. Examples of the green light emitting phosphor include those represented by the following general formula (VI). X represents the amount of the element M added as the emission center, and it is preferable that the atomic ratio be 0.00001 or more and 0.1 or less. If the X value is smaller than 0.00001, the number of Ms as the light emission centers is small, so that the light emission luminance is lowered. If it is greater than 0.1, concentration quenching occurs due to interference between M ions, and the luminance decreases. Y is the amount of the metal element constituting the host crystal, and it is preferable that the atomic ratio be 0.38 or more and 0.46 or less. Preferably, Y = 0.429 is good. When the Y value is out of this range, the bonds in the crystal become unstable, the generation rate of crystal phases other than the β-type Si ₃ N ₄ structure increases, and the green emission intensity decreases. Z is the amount of the nonmetallic element constituting the host crystal, and it is preferable that the atomic ratio be 0.54 or more and 0.62 or less. Preferably, Z = 0.571 is good. When the Z value is out of this range, the bonds in the crystal become unstable, the generation rate of crystal phases other than the β-type Si ₃ N ₄ structure increases, and the green emission intensity decreases.

(Phosphor production method)
The raw materials are weighed so as to have a predetermined composition ratio. In consideration of the possibility of scattering during the manufacturing process, the raw material may be required in a larger amount than a predetermined composition ratio.

  The weighed raw materials are mixed with a mixer or the like. The mixer can be pulverized using a pulverizer such as a vibration mill, a roll mill, a jet mill, or the like, in addition to a ball mill that is usually used industrially, to increase the specific surface area. In addition, in order to keep the specific surface area of the powder within a certain range, it is classified using a wet classifier such as a sedimentation tank, a hydrocyclone, and a centrifugal separator, which are usually used in industry; a dry classifier such as a cyclone and an air separator. You can also

  The mixed raw material is packed in a crucible made of SiC, quartz, alumina or the like, and fired in a reducing atmosphere of N 2 and H 2. As the firing atmosphere, an argon atmosphere, an ammonia atmosphere, or the like can also be used. Firing is performed at a predetermined temperature for several hours.

  The fired product is pulverized, dispersed, filtered, etc. to obtain the desired phosphor powder. Solid-liquid separation can be performed by industrially used methods such as filtration, suction filtration, pressure filtration, centrifugation, and decantation. Drying can be performed by industrially used apparatuses such as a vacuum dryer, a hot-air heating dryer, a conical dryer, and a rotary evaporator.

  The structure of the white LED device backlight used in the liquid crystal display device according to one embodiment of the present invention will be described in detail below.

  As an example of the structure of the white LED device backlight used in the liquid crystal display device according to the embodiment of the present invention, a structure as shown in an assembly diagram shown in FIG. 4 can be given. That is, in a metal frame (or resin frame), a reflective sheet, a light guide plate having a plurality of LEDs (surface mount type light emitting devices) arranged on the side surface, a diffusion sheet, and two prism sheets are sequentially laminated to form a white LED A device backlight is configured. A plurality of LEDs (surface mounted light emitting devices) are attached to the substrate.

  An example of the structure of the LED is shown in FIG. The LED shown here is a surface-mounted light emitting device, but is not limited to this, and a conventionally used insertion type light emitting device can also be used. In the surface mount type light emitting device, a light emitting element 2 is attached to a bottom surface of a concave portion of a light emitting element mounting housing 1 having a concave portion opened upward, and a phosphor 3 is dispersed on the light emitting element 2. The translucent resin 4 covered. The upper electrode of the light emitting element 2 is connected to the first external electrode 6 by the first wire 5, and the lower electrode is connected to the second external electrode 8 by the second wire 7. The light reflecting material 9 is coated on the inner surface of the concave portion of the light emitting element mounting housing 1.

The light-emitting element described above has a light-emitting layer made of a gallium nitride-based compound semiconductor, emits the first peak wavelength in the emission spectrum of the white LED device used in the present embodiment, and the red light emission described above. It serves as an excitation light source for the phosphor and the green-emitting phosphor. Nitride-based compound semiconductors (general formula In _i Ga _j Al _k N, where 0 ≦ i, 0 ≦ j, 0 ≦ k, i + j + k = 1) include various types including InGaN and GaN doped with various impurities. There are things. This element is formed by growing a semiconductor such as InGaN or GaN as a light emitting layer on a substrate by MOCVD or the like.

  Examples of the semiconductor structure include a homostructure having a MIS junction, a PI junction, a PN junction, etc., a heterostructure, or a double heterostructure. The nitride semiconductor layer can have various emission wavelengths depending on the material and the degree of mixed crystal. Moreover, it can also be set as the single quantum well structure and multiquantum well structure which formed the semiconductor active layer with the thin film which produces a quantum effect.

  An example of the configuration of the liquid crystal display device including the white LED device and the color filter obtained as described above will be described below.

  FIG. 6 is a schematic cross-sectional view of a liquid crystal display device according to an embodiment of the present invention. The liquid crystal display device shown in FIG. 6 is a typical example of a TFT drive type liquid crystal display device, and includes transparent substrates 11 and 21 that are arranged to be spaced apart from each other, and liquid crystal (LC) is sealed between them. Yes. A liquid crystal display device according to an embodiment of the present invention includes TN (Twisted Nematic), STN (Super Twisted Nematic), IPS (In-Planes Switching), VA (Vertical Alignment), OCB (Optically Compensated Birefringence), ferroelectric A liquid crystal such as a conductive liquid crystal can be applied.

  A TFT (Thin Film Transistor) array 12 is formed on the inner surface of the first transparent substrate 11, and a transparent electrode layer 13 made of, for example, ITO is formed thereon. An alignment layer 14 is provided on the transparent electrode layer 13. A polarizing plate 15 is formed on the outer surface of the transparent substrate 11.

  On the other hand, a color filter 22 is formed on the inner surface of the second transparent substrate 21. The red, green and blue filter segments constituting the color filter 22 are separated by a black matrix (not shown). A transparent protective film (not shown) is formed as needed to cover the color filter 22, and a transparent electrode layer 23 made of, for example, ITO is formed thereon, and the alignment layer 24 covers the transparent electrode layer 23. Is provided. A polarizing plate 25 is formed on the outer surface of the transparent substrate 21. A backlight unit 30 is provided below the polarizing plate 15.

  The present invention is specifically described by the following examples, but the present invention is not limited thereto.

[Production of backlight]
(White LED device backlight production example 1)
A molten polyphthalamide resin is poured into a mold closed with a pair of positive and negative external electrodes inserted and closed from the gate on the lower surface facing the main surface of the housing, and cured to form the housing. . The housing has an opening that can accommodate the light emitting element, and the positive and negative external electrodes are integrally formed so that one main surface is exposed from the bottom of the opening.

  The outer lead portions of the positive and negative external electrodes exposed from the side surface of the housing are bent inward at both ends of the surface opposite to the light emitting surface. An LED chip having a dominant wavelength peak of 455 nm is die-bonded to the bottom surface of the opening formed in this way with an epoxy resin, and is electrically connected to each external electrode with a wire.

Next, a nitride phosphor CaAlSiBN ₃ having about 0.25 g of halosilicate Ca ₈ MgSi ₄ O ₁₆ Cl ₂ : Eu having an emission peak near 525 nm and an emission peak near 660 nm with respect to 3 g of the silicone resin composition. : Add about 0.06 g Eu and mix.

The translucent resin thus obtained is filled in the housing opening to the same plane line as the upper surface of both ends of the opening. Finally, heat treatment is performed at 70 ° C. for 3 hours and further at 150 ° C. for 1 hour. Thus, the backlight (1) which is a white LED apparatus was obtained (white LED backlight preparation example 2).
In the production of a white LED device, about 0.22 g of a silicate phosphor (Br, Sr) ₂ SiO ₄ : Eu having an emission peak in the vicinity of 530 nm and an emission peak in the vicinity of 660 nm with respect to 3 g of the silicone resin composition. A backlight (2), which is a white LED device, was obtained in the same manner as in Preparation Example 1 except that about 0.04 g of nitride phosphor CaAlSiBN ₃ : Eu was added and mixed.

  For the backlight (1) and the backlight (2), the relative emission intensity spectrum when the maximum emission intensity is 1 is shown in FIG.

The red photosensitive coloring composition for producing a red colored layer of a color filter combined with the above two backlights uses PR254, PR177, and PY150 as organic pigments, and trimethylolpropane tris (3-mercaptobutyrate) as a polyfunctional thiol. (Rate) (hereinafter referred to as TPMB) was shaken to obtain red photosensitive coloring compositions 1 to 9 having a pigment ratio and a TPMB amount (weight ratio in solid content) as shown in Table 1 below.

  Using the red photosensitive coloring compositions 1, 4, 5, 8, and 9 shown in Table 1 above, the film thickness was adjusted so that x = 0.620 when combined with the backlight (1). The colored layers 1 to 5 were formed, and the combination of the backlight (1) and the red colored layers 1 to 5 was taken as Examples 1 to 5.

  The spectral transmittance characteristics of the red colored layers 1 to 5 used in Examples 1 to 5 are shown in FIG.

  Using the red photosensitive coloring composition used in Examples 1 to 5, when combined with the backlight (1), the film thickness was adjusted to x = 0.680 to form red colored layers 6 to 10 And the combination with the backlight (1) was made into Examples 6-10.

  The spectral transmittance characteristics of the red colored layers 6 to 10 used in Examples 6 to 10 are shown in FIG.

  Further, the red photosensitive coloring composition 1 was used, and when combined with the backlight (2), the film thickness was adjusted so that x = 0.620, the red colored layer 11 was formed, and the backlight (2) And a combination of the red colored layer 11 and Comparative Example 1.

  The red photosensitive coloring composition 6 was used, and when combined with the backlight (2), the film thickness was adjusted so that x = 0.620, the red colored layer 13 was formed, and the backlight (2) and red The combination with the colored layer 13 was referred to as Comparative Example 2.

  Using red photosensitive coloring compositions 2, 3, and 7, when combined with the backlight (1), the film thickness was adjusted so that x = 0.620, red colored layers 14 to 16 were formed, and the back The combination of the light (1) and the red colored layers 14 to 16 was set as Comparative Examples 3 to 5.

  The spectral transmittance of the red colored layers 11 to 16 used in Comparative Examples 1 to 5 is shown in FIG.

  In the same combination as the red photosensitive coloring composition and the backlight used in Comparative Examples 1 to 5, the film thickness was adjusted to x = 0.680 to form red colored layers 17 to 22, and the combination Were set as Comparative Examples 6 to 10.

  The spectral transmittance of the red colored layers 17 to 22 used in Comparative Examples 6 to 10 is shown in FIG.

  Hereinafter, evaluation items of Examples and Comparative Examples will be described.

[ Evaluation item ]
(Crimson in backlight)
I: A white LED in which a blue LED, a red light emitting phosphor and a green light emitting phosphor are combined and mixed, and a first peak wavelength 450 to 470 nm, a second peak wavelength 510 to 550 nm, and a third peak wavelength A backlight which is a white LED with three wavelengths of 630 to 670 nm.

  II: A two-wavelength white LED backlight in which a yellow LED is combined with a blue LED.

(Red photosensitive coloring composition used for color filter red coloring layer formation: deep redness in pigment)
A: The red photosensitive coloring composition used for forming the red coloring layer contains PR177 in an amount of 80% or more of the total organic pigment in the solid content.

  B: The red photosensitive coloring composition used for forming the red coloring layer contains PR177 less than 80% of the total organic pigment in the solid content.

(Red photosensitive coloring composition used for color filter red coloring layer formation: polyfunctional thiol)
(1) The red photosensitive coloring composition used for forming the red coloring layer contains 0.1% by weight or more and 20% by weight or less of polyfunctional thiol (TPMB) with respect to the total solid content of the red photosensitive coloring composition.

  (2) The red photosensitive coloring composition used for forming the red coloring layer does not contain polyfunctional thiol (TPMB) or less than 0.1% by weight based on the total solid content of the red photosensitive coloring composition.

  (3) The red photosensitive coloring composition used for forming the red coloring layer contains polyfunctional thiol (TPMB) in an amount of more than 20% by weight based on the total solid content of the red photosensitive coloring composition.

(Red display perception evaluation)
◯: The chromaticity value of the red colored layer is (0.620, 0.280), (0.620, 0.300), (0.680, 0.315), and (0. 680, 0.280) and is perceived as red.

  X: The chromaticity value of the red colored layer is (0.620, 0.280), (0.620, 0.300), (0.680, 0.315), and (0. 680, 0.280) is not perceived as red outside the chromaticity range connecting 680, 0.280).

(If the y value is larger than the range, it is perceived as vermilion to orange. If the y value is smaller than the range, it is perceived as magenta.)
(Cross sectional shape evaluation)
○: Cross-sectional shape is forward tapered ×: Cross-sectional shape is reverse tapered (resolution evaluation)
○: Stripe pattern with 20 μm pitch can be resolved ×: Stripe pattern with 20 μm pitch cannot be resolved
[ Evaluation results ]
Table 2 shows the evaluation results of Examples 1 to 5, Table 3 shows the evaluation results of Examples 6 to 10, Table 4 shows the results of Comparative Examples 1 to 5, and Table 5 shows the results of Comparative Examples 6 to 10. Show.

  From the results of Tables 2 and 3 above, a backlight (backlight evaluation: I) composed of a white LED in which a blue LED, a red light-emitting phosphor and a green light-emitting phosphor are combined and mixed, and a pigment PR177 having a high crimson property. In the total solid content of the organic pigment (Pigment evaluation: A) When combined with a color filter formed using a red photosensitive coloring composition (Examples 1 to 5), all display in red The characteristics were good.

  Further, a backlight (backlight evaluation: I) composed of a white LED in which a blue LED, a red light-emitting phosphor and a green light-emitting phosphor are combined and mixed, and a pigment PR177 having a high crimson property are included in the total solid content of the organic pigment. Including 80% or more (Pigment Evaluation: A) When combined with a color filter formed using a red photosensitive coloring composition, even if the organic pigment contains the yellow pigment PY150 (Example 3), red display The characteristics were good within the specified chromaticity range. As described above, the present invention can be carried out even when a yellow pigment is included as a toning. However, since the deep redness is inferior to the system that does not include the toning with the yellow pigment, it is not desirable to contain it excessively.

  As shown in Tables 4 and 5 above, when a backlight composed of a white LED (backlight evaluation: II) in which a blue LED and a yellow light-emitting phosphor are combined and mixed, a pigment PR177 having a high crimson property is used. Even if the color filter formed using the red photosensitive coloring composition is used (Comparative Examples 1 and 6), the red display characteristics are poor. Met.

  Regardless of the type of the backlight, the color filter formed using the red photosensitive coloring composition containing less than 80% of the pigment PR177 having a high deep redness in the total solid content of the organic pigment (pigment evaluation: B) Was used (pigment evaluation: B) (Comparative Examples 2 and 9), the red display characteristics were poor.

  From the above results, the backlight is a white LED in which a blue LED, a green light emitting phosphor and a red light emitting phosphor are mixed, and the red photosensitive coloring composition forming the red colored layer of the color filter has a high crimson property. When 80% or more of the pigment PR177 is contained, four points (0.620, 0.280), (0.620, 0.300), (0.680, 0.315) are displayed in the xy chromaticity coordinate system when displaying red. ) And (0.680, 0.280), it has been found that it is possible to achieve a crimson chromaticity that can be perceived as red within the chromaticity range connecting (0.680, 0.280).

The characteristic view which shows the light emission characteristic of white LED which mixed blue LED, the red light emission fluorescent substance, and the green light emission fluorescent substance and was mixed. The characteristic view which shows the light emission characteristic of a cold cathode fluorescent tube (CCFL). The characteristic view which shows the light emission characteristic of pseudo white LED. The figure which shows the structure of LED backlight. Sectional drawing which shows the structure of a white LED apparatus. FIG. 3 is a schematic cross-sectional view illustrating a structure example of a liquid crystal display device. The characteristic view which shows the light emission characteristic of backlight (1) and (2). The characteristic view which shows the spectral transmittance of the red colored layers 1-5. The characteristic view which shows the spectral transmittance of the red colored layers 6-10. The characteristic view which shows the spectral transmittance of the red colored layers 11-16. The characteristic view which shows the spectral transmittance of the red colored layers 17-22.

Claims (9)

  A liquid crystal display device comprising a backlight having a white LED device in which a blue LED, a red light emitting phosphor and a green light emitting phosphor are combined, and a color filter having a plurality of colored pixels including red pixels on a transparent substrate. The emission spectrum of the white LED device has a first peak wavelength at 440 nm to 470 nm, a second peak wavelength at 510 nm to 550 nm, a third peak wavelength at 630 nm to 670 nm, and the red pixel The red color of the liquid crystal display device is formed from a cured product of a red photosensitive color composition containing 0.1% by weight or more and 20% by weight or less of polyfunctional thiol with respect to the total solid content of the red photosensitive color composition. The degrees are the following four points (0.620, 0.280), (0.620, 0.300), (0.680, 0.3) in the xy chromaticity coordinate system. 5), and (a liquid crystal display device which is characterized in that in the chromaticity range connecting the 0.680,0.280).   The red pixel has an organic pigment CI. Of 80% or more of the total organic pigment of solid content. 2. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is formed of a cured product of a red photosensitive coloring composition containing pigment number PR177. The red light emitting phosphor is a nitride phosphor represented by the following general formula (I) that is activated by Eu and includes the Group II elements M, Si, Al, B, and N, and is capable of emitting ultraviolet or blue light. The liquid crystal display device according to claim 1, wherein the liquid crystal display device emits red light.
^{_{M 1 w Al x Si y B}} z N ((2/3) w + x + (4/3) y + z): Eu 2+ (I)
(In the formula, M ¹ is at least one selected from the group consisting of Mg, Ca, Sr, and Ba, and w, x, y, and z are 0.056 ≦ w ≦ 9, x = 1,. (056 ≦ y ≦ 18, 0 ≦ z ≦ 0.5) The liquid crystal display device according to claim 1, wherein the green light emitting phosphor is represented by the following general formula (II).
^{_{Ba 5-x-y Eu x}} M 2 y Si m O 5 + 2m (II)
(In the formula, M ² is at least one of Ca and Sr, and x, y, and m are 0.0001 ≦ x ≦ 0.3, 0 ≦ y ≦ 0.8, 2.5 <m <3. 5) The liquid crystal display device according to claim 1, wherein the green light emitting phosphor is represented by the following general formula (III).
(M ³ _1-y R _y ) _a MgM ⁴ _b M ⁵ _c O _{a + 2b + (3/2) c} X ₂ (III)
(Wherein M ³ is at least one selected from the group consisting of Ca, Sr, Ba, Zn, and Mn, M ⁴ is at least one selected from the group consisting of Si, Ge, and Sn, and M ⁵ is B , Al, Ga, and In, at least one selected from the group consisting of In, X is at least one selected from the group consisting of F, Cl, Br, and I, and R must be Eu selected from rare earth elements At least one, y, a, b and c are 0.0001 ≦ y ≦ 0.3, 7.0 ≦ a <10.0, 3.0 ≦ b <5.0, 0 ≦ c <1 .0.) The liquid crystal display device according to claim 1, wherein the green light-emitting phosphor is represented by the following general formula (IV) or (V).
^{_{L X M 6 Y O Z N}} ((2/3) X + (4/3) Y- (2/3) Z): R (IV)
Or ^{_{L X M 6 Y Q T O}} Z N ((2/3) X + (4/3) Y + T- (2/3) Z): R (V)
(Wherein L is at least one group II element selected from the group consisting of Be, Mg, Ca, Sr, Ba, and Zn, and M ⁶ is C, Si, Ge, Sn, Ti, And at least one group IV element selected from the group consisting of Zr and Hf, and Q is at least one group III element selected from the group consisting of B, Al, Ga, and In, and R Is a rare earth element, and X, Y, T, and Z are 0.5 <X <1.5, 1.5 <Y <2.5, 0 <T <0.5, 1.5 <Z <. 2.5.) The liquid crystal display device according to claim 1, wherein the green light emitting phosphor is represented by the following general formula (VI).
(M ⁷ _1-X Eu _X ) ₂ Si _{Y 2} O _{+ 2} (VI)
(Wherein M ⁷ is at least one group II element selected from the group consisting of Be, Mg, Ca, Sr, Ba, and Zn, and X and Y are 0.001 ≦ X ≦ 0.2. 0.9 ≦ Y ≦ 1.1.) The liquid crystal display device according to claim 1, wherein the green light emitting phosphor is represented by the following general formula (VII).
^{_{M 8 X A Y X Z (}} VII)
(Wherein M ⁸ is at least one element selected from the group consisting of Mn, Ce, Eu, and A is selected from the group consisting of C, Si, Ge, Sn, B, Al, Ga, In) At least one element selected from the group consisting of O and N, and X, Y, and Z are 0.00001 ≦ X ≦ 0.1, 0.38 ≦ Y ≦ 0.46, 0.54 ≦ Z ≦ 0.62 and X + Y + Z = 1.)   A color filter comprising a plurality of colored pixels including a red pixel on a transparent substrate, the color filter being used for a liquid crystal display device according to claim 1.

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