JP2019008161A - Resin composition for color correction optical filter and color correction optical filter containing resin composition - Google Patents

Abstract

To provide a resin composition for a color correction optical filter to be used in a liquid crystal display using an LED as a light source, the filter capable of selectively absorbing light with poor color purity in an unnecessary wavelength region transmitted through a color filter without decreasing brightness of the liquid crystal display.SOLUTION: A colored composition is provided, comprising a transparent resin and a squarylium compound represented by formula (1) and having such a property that in an ultraviolet-visible absorption spectrum of a solution prepared by dissolving the compound in a solvent, an absorption spectrum at λmax has a width of a specific value or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a resin composition for a color correction optical filter used in a liquid crystal display, a color correction optical filter containing the resin composition, and a liquid crystal display device equipped with the color correction optical filter.

  A display device as a display device starts with a cathode ray tube, and from around 2000, a liquid crystal display (LCD) and a plasma display (PDP) have started to spread in place of the cathode ray tube. At present, liquid crystal display devices are mainly used in a wide range of fields from the viewpoint of increasing size, thickness, weight, and power consumption.

  In 2012, the BT. 2020 was recommended and video parameters for 4K and 8K video were formulated. BT. With the establishment of a color gamut standard for ultra-high definition television by 2020, in recent years it has been strongly desired to develop a liquid crystal display having a wide color reproducibility adapted to this color gamut standard.

Unlike a self-luminous device such as an organic light emitting diode (OLED), a liquid crystal display widely used for color televisions, notebook computers, and the like uses a backlight unit disposed on the back of a liquid crystal panel as a light source. Conventionally, cold cathode fluorescent lamps (CCFLs) have been widely used as backlight sources for liquid crystal display devices, but in recent years light emitting diodes (LEDs) with significantly improved brightness and power consumption have been used instead of cold cathode fluorescent lamps. It came to be.
A white LED light source is used as an LED light source used in a liquid crystal display. As a typical method, (1) a white LED that combines three LEDs of red, green, and blue light emission to form a white light source. And (2) a white LED composed of a blue light emitting LED and a red and green light emitting phosphor, and (3) a white LED composed of a blue light emitting LED and a yellow light emitting phosphor. The method (1) has color reproducibility in a wider area than a liquid crystal display device using a cold cathode tube, but is not preferable in terms of power consumption and manufacturing cost because it uses three LEDs. In addition, the methods (2) and (3) are advantageous in terms of high luminous efficiency and low power consumption, but have a problem of poor color reproducibility.

  In a liquid crystal display, light emitted from a backlight light source is passed through a color filter, so that only the spectral ranges of red (R), green (G), and blue (B) are extracted to reproduce colors. However, each of the R, G, and B color filters has a region that cannot absorb all unnecessary light. Specifically, this corresponds to the intermediate wavelength region of R and G of the color filter (the portion hitting yellow light: around 590 nm) and the intermediate wavelength region of G and B (the portion hitting blue-green light: around 490 nm). That is, there is a region where part of yellow light is transmitted through the red color filter, part of yellow and blue-green light is transmitted through the green color filter, and part of blue-green light is transmitted through the blue color filter. Therefore, in the case of the methods (2) and (3), the color purity of the light transmitted through the color filter is lowered and the color reproducibility is deteriorated.

  In order to solve this problem, a method of increasing the color purity of the light source as much as possible can be considered. For example, Patent Document 1 proposes a backlight unit that combines a blue LED and a quantum dot (QD). Although quantum dots have a strong emission spectrum in a narrow wavelength band, they are effective in improving color reproducibility and reducing power consumption. In general, however, materials that form quantum dots include CdSe (cadmium selenide) and CdS (cadmium sulfide). ), Which is an environmentally problematic cadmium compound, is mainly used, and is not preferable in terms of manufacturing and disposal. In addition, although quantum dot materials that do not use cadmium compounds have been developed, no alternative material having satisfactory performance has been found from the viewpoint of luminous efficiency and durability.

  Therefore, as another method for improving the color reproducibility of the liquid crystal display, a method of introducing a color correction optical filter that absorbs light in an unnecessary area with poor color purity transmitted through the color filter into the liquid crystal display device has been proposed. ing. In the case of this method, a conventional LED light source can be used for the backlight unit only by using a color correction optical filter using an organic dye or the like that absorbs a predetermined wavelength, but it absorbs a specific wavelength. Organic dyes and the like are required not only to absorb light in unnecessary areas but also to absorb as little light as possible in order not to reduce the brightness of the liquid crystal display. For example, Patent Documents 2 and 3 describe a color correction optical filter using a squarylium compound having an indole ring as an organic dye. The color correction optical filter cuts off unnecessary neon light for a plasma display. In addition to the optimal light absorption wavelength range as a color correction filter for liquid crystal displays, there is no mention of light absorption in a necessary region. Patent Document 4 describes a squarylium compound having an indole ring, but as a result of the study by the present inventors, the shape of an ultraviolet-visible absorption spectrum when dissolved in a solvent is insufficient for use in a color correction optical filter. In the case where a color correction optical filter containing the compound is used for a liquid crystal display, there is a concern that the brightness of the display is lowered by absorbing light in a necessary wavelength region.

Special table 2013-539170 gazette JP 2003-35818 A WO2004 / 005981 Japanese Patent No. 4785541

  The present invention relates to a color correction optical filter used in a liquid crystal display using an LED as a light source, and transmits light in an unnecessary wavelength region having a poor color purity transmitted through the color filter without reducing the brightness of the liquid crystal display. An object of the present invention is to provide a resin composition for a color correction optical filter capable of selectively absorbing water, and a color correction optical filter containing the composition.

  As a result of intensive studies to solve the above problems, the inventor has expressed at least the following formula (1) as an organic dye in a color correction filter that absorbs unnecessary light with poor color purity that passes through the color filter. It was found that the above-mentioned problems can be solved by using a squarylium compound having an indole ring and a resin composition comprising a transparent resin having an ultraviolet-visible absorption spectrum having a specific parameter, and the present invention has been completed. It was.

That is, the present invention
(1) A resin composition for a color correction optical filter used in a liquid crystal display using an LED as a light source, which has the following formula (1)

(In Formula (1), R ¹ and R ² represent an alkyl group having 1 to 10 carbon atoms or a phenyl group, and a plurality of R ¹ may be the same or different from each other, and a plurality of R ² are The absorption spectrum width at the absorbance A / 2 is 40 nm or less, where A is the absorbance at λmax of the UV-visible absorption spectrum of the solution dissolved in the solvent. And a squarylium compound having an absorption spectrum width at an absorbance A / 8 of 100 nm or less, and a resin composition containing a transparent resin,
(2) The resin composition according to item (1), wherein R ¹ is an alkyl group having 1 to 10 carbon atoms,
(3) The resin composition as described in (1) or (2) above, wherein the transparent resin comprises a polymer or copolymer made from an acrylic acid alkyl ester monomer.
(4) The preceding item (3) wherein the acrylic acid alkyl ester monomer is at least one selected from the group consisting of n-butyl (meth) acrylate, t-butyl (meth) acrylate, and methyl (meth) acrylate. ) The resin composition according to
(5) A color correction optical filter comprising the resin composition according to any one of (1) to (4) above, and a color correction optical filter for a liquid crystal display using an LED as a light source, and (6) Liquid crystal display device equipped with the described color correction optical filter,
About.

  The resin composition of the present invention is excellent in selectively absorbing light in a poor color purity range (λmax 500 to 700 nm, particularly 570 to 610 nm) that is transmitted through the color filter, and the resin composition is used. Thus, it is possible to provide a color correction filter for a liquid crystal display that is excellent in color reproducibility without reducing the brightness of the liquid crystal display.

4 is a measurement result of spectral characteristics of the color correction optical filter 1 of the present invention obtained in Example 2. FIG.

  The resin composition of the present invention has an absorption spectrum width of 40 nm or less at an absorbance A / 2 and an absorption spectrum at an absorbance A / 8, where A is the absorbance at λmax of the UV-visible absorption spectrum of a solution dissolved in a solvent. Containing a squarylium compound represented by the formula (1) having a width of 100 nm or less and a transparent resin.

  As the solvent for dissolving the squarylium compound represented by the formula (1), an oil-soluble organic solvent can be used. Examples of the oil-soluble organic solvent used include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, pentanol, octanol, cyclohexanol, benzyl alcohol, and tetrafluoropropanol; ethylene glycol monoethyl Glycol derivatives such as ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monoethyl ether, ethylene glycol diacetate, propylene glycol diacetate ; Acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, etc. Ketones; ethers such as butyl phenyl ether, benzyl ether, hexyl ether; esters such as ethyl acetate, butyl acetate, ethyl benzoate, butyl benzoate, ethyl laurate, butyl laurate; acetonitrile, dimethylformamide (hereinafter, DMF), dimethyl sulfoxide, sulfolane, N-methylpyrrolidone (hereinafter referred to as NMP), 2-pyrrolidone and the like, and these solvents may be used alone. Two or more kinds may be mixed and used.

As the squarylium compound represented by the formula (1), it is preferable that unnecessary light with poor color purity transmitted through the color filter is selectively absorbed and at the same time, the necessary light is not absorbed as much as possible. That is, it is preferable that the width of the absorption spectrum when dissolved in a solvent is narrow (in other words, the absorption spectrum is sharp).
Specifically, when the absorbance at λmax of the ultraviolet-visible absorption spectrum of a solution obtained by dissolving the squarylium compound represented by the formula (1) in the above solvent is A, the width of the absorption spectrum at normal absorbance A / 2 is 40 nm or less, absorption spectrum width at absorbance A / 8 is 100 nm or less, absorption spectrum width at absorbance A / 2 is 35 nm or less, and absorption spectrum width at absorbance A / 8 is 80 nm or less. Is preferred.
The measuring device used for measuring the UV-visible absorption spectrum is not particularly limited as long as it is a commonly used UV-visible absorption spectrum measuring device, and the concentration of the solution used for the measurement is also the absorbance A / 2. As long as the width of the absorption spectrum at A / 8 can be discriminated, there is no particular limitation.

  Λmax of the UV-visible absorption spectrum of a solution in which the squarylium compound represented by the formula (1) is dissolved in a solvent is usually 500 to 700 nm, which is an intermediate wavelength region of the R and G color filters, and is 540 to 650 nm. The thickness is preferably 570 to 610 nm.

In the above formula (1), R ¹ and R ² represent an unsubstituted alkyl group having 1 to 10 carbon atoms or a phenyl group, and a plurality of R ¹ may be the same or different from each other, and a plurality of R ¹ exist. R ² may be the same as or different from each other.

The alkyl group having 1 to 10 carbon atoms represented by R ¹ and R ^{2 in} Formula (1) is not limited to any of linear, branched or cyclic as long as the alkyl group has 1 to 10 carbon atoms. Specific examples thereof are methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, t-butyl group, n-pentyl group, 1-methylbutyl. Group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylpropyl group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, 2,2-dimethylpropyl group, n-hexyl group, 1-methyl Pentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 1,1-dimethylbutyl group, 1,2-dimethylbutyl group, 1,3-dimethylbutyl group, 2,2-dimethylbutyl Group, 2,3-dimethylbutyl group, 3,3-dimethylbutyl group, 1-ethyl-1-methylpropyl group, heptyl group, octyl group, nonyl group, decyl group, cyclohexyl group, 2-methylcyclohexyl group , 2-ethylcyclohexyl group, cycloheptyl group, cyclooctyl group, etc., wherein a plurality of R ¹ are the same alkyl group having 1 to 10 carbon atoms or a phenyl group, and a plurality of R ² are the same. Preferably, it is an alkyl group having 1 to 10 carbon atoms or a phenyl group, and a plurality of R ¹ are the same linear alkyl group or phenyl group having 1 to 10 carbon atoms, and a plurality of R ² are the same carbon. number 1 is more preferably a straight chain alkyl group or a phenyl group 10, a straight-chain alkyl group of R ¹ is the same carbon number 1 to 10 there are a plurality of There, and more preferably R ² there are multiple are identical straight-chain alkyl group or a phenyl group having 1 to 10 carbon atoms, a straight-chain alkyl group of the plurality present R ¹ is the same carbon number 1 to 10 It is particularly preferable that a plurality of R ² groups are the same linear alkyl group having 1 to 4 carbon atoms or phenyl group.

  The content of the squarylium compound represented by the formula (1) and having a specific spectral width in the resin composition of the present invention is 0.000 in the total solid content (all components excluding the solvent) of the resin composition of the present invention. It is preferably 1 to 10% by mass, more preferably 0.3 to 5% by mass, and further preferably 0.5 to 2% by mass. If the content of the squarylium compound is less than 0.1% by mass, the desired effect may not be obtained. If the content of the squarylium compound is excessive, the squarylium compound precipitates in the resin composition and the color correction optics There is a possibility that the transparency of the filter and the adhesiveness between the resin composition and the substrate may be lowered.

The squarylium compound represented by the formula (1) contained in the resin composition of the present invention can be produced by various methods. For example, it can be produced by the following method with reference to the method described in Dies and Pigments, 49 (2001), pages 161-179. In the following formulas (A) to (E), R ¹ and R ² represent the same meaning as R ¹ and R ² in the above formula (1), respectively, and R ³ represents a halogen atom (for example, chlorine atom, bromine). Atom) or an unsubstituted alkoxy group having 1 to 4 carbon atoms (for example, a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, etc.).

  A commercially available product of a squaric acid derivative represented by the following formula (A) and a corresponding indole compound represented by the following formula (B) in an oil-soluble organic solvent at a predetermined temperature (for example, 20 ° C. to 150 ° C. C.), a semi-squarylium compound represented by the following formula (C) can be obtained. Next, a compound represented by the following formula (D) obtained by hydrolysis at a predetermined temperature (for example, 20 ° C. to 120 ° C.) in a mixed solvent of a water-soluble organic solvent and water, The squarylium compound represented by the formula (1) can be produced by reacting the compound represented by the formula (E) with a predetermined temperature (for example, 20 to 150 ° C.) in an oil-soluble organic solvent. .

  Examples of the oil-soluble organic solvent used in the reaction in the first step and the third step of the synthesis scheme exemplified above include methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, benzene, toluene, and the like. Xylene or the like is preferably used alone or in combination. The reaction temperature is preferably 20 to 150 ° C., more preferably 50 to 120 ° C., and still more preferably 70 to 105 ° C. As the water-soluble organic solvent used in the second-step reaction, for example, acetic acid and propion are preferably used. In the second-step hydrolysis reaction, an acid catalyst can be added as necessary. Examples of usable acid catalysts include inorganic acids such as hydrochloric acid and sulfuric acid, and Lewis acids such as aluminum chloride. be able to.

When the compounds represented by the formulas (B) and (E) are the same, that is, in the formula (1), a plurality of R ¹ are the same and a plurality of R ² are the same. In this case, the squarylium compound represented by the above formula (1) can also be produced by the production method shown below.

The manufacturing method illustrated below is demonstrated. An oil-soluble organic solvent comprising 3,4-dihydroxy-3-cyclobutene-1,2-dione represented by the following formula (F) available as a commercial product and the corresponding indole compound represented by the following formula (B) The compound represented by the above formula (1) can be produced by reacting at a predetermined temperature (for example, 20 ° C. to 150 ° C.).
The oil-soluble organic solvent used in the synthesis scheme exemplified below is, for example, methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, benzene, toluene, xylene, etc. alone or in combination. It is preferable to use it. The reaction temperature is preferably 20 to 150 ° C., more preferably 50 to 120 ° C., and still more preferably 70 to 105 ° C.

  Specific examples of the squarylium compound represented by the above formula (1) are shown below, but the present invention is not limited to these specific examples.

The transparent resin contained in the resin composition of the present invention is not particularly limited as long as it has high transparency and can dissolve or uniformly disperse the squarylium compound, but a polymer of an acrylic acid alkyl ester monomer and / or A transparent resin containing a copolymer of an acrylic acid alkyl ester monomer and another monomer is preferable.
The “transparent” in the transparent resin is not particularly limited as long as the light in the visible light region is transmitted. However, when the transparent resin is a thin film of 10 to 20 μm, the transmittance in the visible light region is 97% or more. Preferably there is.

Examples of the acrylic acid alkyl ester monomer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, i-propyl (meth) acrylate, n-propyl (meth) acrylate, i- (meth) acrylate. Examples thereof include alkyl esters having 1 to 12 carbon atoms of (meth) acrylic acid such as butyl, n-butyl (meth) acrylate, t-butyl (meth) acrylate and dodecyl (meth) acrylate. In the synthesis of the polymer, these may be used alone or in combination of a plurality of types, but a combination of a plurality of types is preferably used as a copolymer.
The acrylic acid alkyl ester monomer used for the synthesis of the polymer or copolymer is selected from the group consisting of n-butyl (meth) acrylate, t-butyl (meth) acrylate, and methyl (meth) acrylate. 1 type or 2 types are preferable, and two types of (meth) acrylate n-butyl and (meth) acrylate t-butyl are used in combination, or (meth) acrylate n-butyl, (meta It is more preferable to use a combination of t-butyl acrylate and methyl (meth) acrylate. In the present specification, for example, the description “(meth) acrylic acid” means “acrylic acid” and / or “methacrylic acid”.

  The amount of the acrylic acid alkyl ester monomer used when synthesizing the copolymer is preferably 50 to 100% by mass, more preferably 70 to 95% by mass, based on all monomer components used in the synthesis. By setting the content of the acrylic acid alkyl ester monomer to 50% by mass or more, the solubility of the squarylium compound in the transparent resin ((co) polymer) is enhanced, and a decrease in transmittance due to precipitation of the squarylium compound can be suppressed. . Furthermore, the color correction optical filter containing a resin composition containing a transparent resin can be improved in durability and light resistance at high temperatures and high humidity, and can be added to the resin composition as necessary, for example, generation of foaming and minute defects. Decrease in adhesion between the resin composition and the substrate such as glass or film due to precipitation of UV absorbers and transparency are difficult to occur, and discoloration and white turbidity of the color correction optical filter due to alteration of the transparent resin , And deterioration such as physical destruction can be reduced.

  Other monomers used for the synthesis of a copolymer of an acrylic acid alkyl ester monomer and another monomer are particularly limited as long as they have a carbon-carbon double bond copolymerizable with an acrylic acid alkyl ester monomer. However, for example, a polymerizable monomer having a hydroxyl group, a polymerizable monomer having an amide group, a polymerizable monomer having a carboxyl group, and the like may be used. For the synthesis of the copolymer, these may be used alone or in combination. It may be used.

  Examples of the polymerizable monomer having a hydroxyl group include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl acrylate, and 3-chloro-2- Examples thereof include hydroxyalkyl (meth) acrylates having 1 to 5 carbon atoms such as hydroxypropyl methacrylate, and diethylene glycol (meth) acrylates such as diethylene glycol monoacrylate and diethylene glycol monomethacrylate. The amount of the polymerizable monomer having a hydroxyl group when synthesizing the copolymer is preferably 0.5 to 7 parts by mass with respect to 100 parts by mass of the acrylic acid alkyl ester monomer, and 0.8 to 4 More preferably, it is 3 parts by mass. By using a copolymer of an acrylic acid-based alkyl ester monomer and a polymerizable monomer having a hydroxyl group as a transparent resin, the transparency of the transparent resin is increased and color correction optics including a resin composition containing the transparent resin The durability and light resistance of the filter at high temperature and high humidity can be improved.

  Examples of polymerizable monomers having an amide group include N, N-dimethylaminopropylacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, acryloylmorpholine, N-isopropylacrylamide, N-methylolacrylamide, and acrylamide. Examples include acrylamide monomers. The amount of the polymerizable monomer having an amide group used for synthesizing the copolymer is preferably 0.5 to 29 parts by mass with respect to 100 parts by mass of the acrylic acid alkyl ester monomer. More preferably, it is a part. By using a copolymer of an acrylic acid-based alkyl ester monomer and a polymerizable monomer having an amide group as a transparent resin, the transparency of the transparent resin is enhanced and the color correction includes a resin composition containing the transparent resin. The durability and light resistance of the optical filter at high temperature and high humidity can be improved.

Examples of the polymerizable monomer having a carboxyl group include acrylic acid, methacrylic acid, maleic acid and itaconic acid. The amount of the polymerizable monomer having a carboxyl group used for synthesizing the copolymer is preferably 0.5 to 7 parts by mass with respect to 100 parts by mass of the acrylic acid alkyl ester monomer. More preferably, it is 3 parts by mass. By making the use amount of the polymerizable monomer having a carboxyl group in the above range, the transparency of the transparent resin is increased, and the color correction optical filter including the resin composition containing the transparent resin has a high temperature and a high humidity. Durability and light resistance can be improved.
When the polymerizable monomer having a carboxyl group is used for copolymerization with an acrylic acid alkyl ester monomer in combination with a polymerizable monomer having an amide group, the compatibility with each other is not inhibited, and the transparency of the transparent resin is reduced. This is preferable.

For the synthesis of the copolymer, a polymerizable monomer having a functional group such as glycidyl methacrylate and allyl glycidyl ether may be used. The amount of the polymerizable monomer having a functional group used for synthesizing the copolymer is preferably 0.5 to 7 parts by mass with respect to 100 parts by mass of the acrylic acid alkyl ester monomer, and 0.8 to It is more preferable that it is 4.3 parts by mass.
For the synthesis of the copolymer, a polymerizable monomer having no functional group such as vinyl acetate, acrylonitrile and styrene may be used. The amount of the polymerizable monomer having no functional group for synthesizing the copolymer is preferably 0 to 43 parts by mass with respect to 100 parts by mass of the acrylic acid alkyl ester monomer. By using a copolymer of an acrylic acid alkyl ester monomer and a polymerizable monomer having no functional group as a transparent resin, the transparency of the transparent resin is enhanced and the resin composition used as a color correction optical filter The adhesion to the base material and the coating property to the base material can be improved.

  Polymers of acrylic acid alkyl ester monomers and copolymers of acrylic acid alkyl ester monomers and other monomers contain monomer units based on each monomer component used in the synthesis, and the content of each monomer unit is the content of each monomer component. It corresponds to the amount used. Accordingly, the polymer of acrylic acid alkyl ester monomer or the copolymer of acrylic acid alkyl ester monomer and other monomer preferably contains 50 to 100% by mass of monomer units based on acrylic acid alkyl ester monomer, and is optional. In particular, the monomer unit based on the polymerizable monomer having a hydroxyl group is preferably 0.5 to 7 parts by mass based on the polymerizable monomer having an amide group, based on 100 parts by mass of the monomer unit based on the acrylic acid alkyl ester monomer. Preferably 0.5 to 29 parts by weight of monomer units, preferably 0.5 to 7 parts by weight of monomer units based on a polymerizable monomer having a carboxyl group, and / or based on a polymerizable monomer having no functional group Contains 43 parts by mass or less of monomer units.

  In order to further improve the durability of the color correction optical filter containing the resin composition, 100 parts by mass of an acrylic acid alkyl ester monomer, 0.5 to 7 parts by mass of a polymerizable monomer having a hydroxyl group, and an amide group It is preferable to synthesize a copolymer using 0.5 to 29 parts by mass of a polymerizable monomer. By further adding 0.5 to 7 parts by weight of a polymerizable monomer having a carboxyl group to the above combination, durability at high temperature and high humidity, light resistance, transparency, adhesion to a substrate, etc. are further improved. Can be made.

  Polymers of acrylic acid alkyl ester monomers and copolymers of acrylic acid alkyl ester monomers and other monomers are prepared by dissolving the above monomer components in an organic solvent and radically polymerizing them in an organic solvent by a general method. Can be synthesized. Examples of the organic solvent used for polymerization include aromatic hydrocarbons such as toluene and xylene, esters such as ethyl acetate and butyl acetate, aliphatic alcohols such as n-propyl alcohol and i-propyl alcohol, and Examples thereof include ketones such as methyl ethyl ketone and methyl isobutyl ketone. Examples of the polymerization catalyst used for radical polymerization include azobisisobutyronitrile, benzoyl peroxide, di-t-butyl peroxide, cumene hydroperoxide, and the like, which are normal polymerization catalysts.

  The glass transition temperature of the polymer of the acrylic acid alkyl ester monomer and the copolymer of the acrylic acid alkyl ester monomer and the other monomer is usually −20 ° C. or lower, preferably −30 ° C. to −60 ° C., The weight average molecular weight is preferably 500,000 to 2,000,000, and more preferably 700,000 to 1,600,000.

  The resin composition of the present invention may contain a crosslinking agent. The crosslinking agent crosslinks a polymer of an acrylic acid alkyl ester monomer and / or a copolymer of an acrylic acid alkyl ester monomer and another monomer, and the resin composition of the present invention or a color correction optical filter including the resin composition There is an effect of further improving the durability of the. The type of the crosslinking agent can be appropriately selected by those skilled in the art. For example, polyisocyanate compounds such as aliphatic diisocyanate and aromatic diisocyanate, melamine compounds such as butyl etherified styrene melamine and trimethylol melamine, diamine compounds such as hexamethylenediamine or triethyldiamine, epoxy resin compounds such as bisphenol A type, Urea resin compounds and metal salts such as aluminum chloride, ferric chloride or aluminum sulfate are used as the crosslinking agent. The content of the crosslinking agent in the resin composition of the present invention is 0.001 to 10% by mass based on the polymer of the acrylic acid alkyl ester monomer and / or the copolymer of the acrylic acid alkyl ester monomer and another monomer. It is preferable that the content is 0.01 to 3% by mass. Depending on the type of the cross-linking agent, the cross-linking reaction occurs even at room temperature.

The resin composition of the present invention may contain components other than the squarylium compound represented by formula (1) and the transparent resin (hereinafter referred to as “other components”).
Other components include, for example, oil-soluble organic solvents and water-soluble organic solvents, and various additives. In the range that does not impair the effects of the resin composition, one or more of these are used. It can be used with no particular restrictions according to the usage.

  Specific examples of the oil-soluble organic solvent include alcohols such as methanol, ethanol, n-propanol, i-propanol, n-butanol, pentanol, octanol, cyclohexanol, benzyl alcohol, and tetrafluoropropanol; ethylene glycol monoethyl ether , Diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monoethyl ether, ethylene glycol diacetate, propylene glycol monomethyl ether acetate, propylene glycol di Glycol derivatives such as acetate; methyl ethyl ketone, cyclo Ketones such as xanone; ethers such as butylphenyl ether, benzyl ether, hexyl ether; esters such as ethyl acetate, butyl acetate, ethyl benzoate, butyl benzoate, ethyl laurate, butyl laurate; acetonitrile, DMF, Examples include polar organic solvents such as dimethyl sulfoxide, sulfolane, NMP, and 2-pyrrolidone.

  Examples of the water-soluble organic solvent include alcohols such as methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, t-butanol, pentanol, and benzyl alcohol; ethylene glycol, diethylene glycol, triethylene Polyhydric alcohols such as glycol, propylene glycol, polyethylene glycol, polypropylene glycol, glycerin, trimethylolpropane, 1,3-pentanediol and 1,5-pentanediol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl Ether, diethylene glycol monobutyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl Glycol derivatives such as ether and dipropylene glycol monomethyl ether; ethanolamine, diethanolamine, amines such as triethanolamine and morpholine; 2-pyrrolidone, NMP, 1,3-dimethyl - imidazolidinone.

  These solvents may be used alone or in combination of two or more. When the solvent is contained, the amount used is preferably 40 to 500 parts by mass, and more preferably 50 to 200 parts by mass with respect to 100 parts by mass of the total solid content of the resin composition.

Examples of other components other than the solvent that can be contained in the resin composition of the present invention include an antioxidant, a photo-oxidant, and an ultraviolet absorber.
Specific examples of the antioxidant include phenolic antioxidants; phosphorus antioxidants; sulfur antioxidants; amine antioxidants such as hindered amines, naphthylamines, and phenylenediamines.
Specific examples of the photo-oxidant include hindered amine light stabilizers.
Specific examples of UV absorbers include benzotriazole UV absorbers, benzophenone UV absorbers, triazine UV absorbers, cyanoacrylate UV absorbers, oxanilide UV absorbers, salicylate UV absorbers, and formamidines. An ultraviolet absorber etc. are mentioned.

  The color correction optical filter containing the resin composition of the present invention comprises at least a transparent substrate such as glass and various films, and a resin layer (adhesive layer) comprising the resin composition of the present invention provided on one or both sides of the transparent substrate. With. The resin layer may be disposed so as to be in direct contact with the substrate, or may be disposed on the substrate with a layer such as a protective layer provided on the substrate interposed therebetween. Although the film used as a transparent base material is not specifically limited, For example, a polarizing film or retardation film is mentioned. As a polarizing film, a film formed from a polyvinyl alcohol resin such as polyvinyl alcohol, polyvinyl formal, polyvinyl acetal, saponified ethylene-vinyl acetate copolymer is impregnated with a polarizing element such as iodine or a dichroic dye and stretched. Those imparted with polarization by being used are preferably used, but may be of other types. As the retardation film, a film provided with retardation by stretching a film produced from a resin such as polyvinyl alcohol, polycarbonate, cycloolefin, etc. is suitably used. May be a coated film or membrane.

  As the transparent substrate, it is preferable to use a plastic or the like that is excellent in transparency, mechanical strength, thermal stability, moisture shielding properties, etc., but on one or both sides of the color correction optical filter of the present invention, A plastic film having excellent properties described above may be further provided as a protective layer. Examples of the plastics excellent in the above properties include cellulose resins such as polyester resins and triacetyl cellulose; acetate resins, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins. And thermoplastic resins such as acrylic resins; thermosetting resins such as acrylic, urethane, acrylic urethane, epoxy, and silicone; and ultraviolet curable resins. The polyolefin-based resin may be an amorphous polyolefin-based resin having a polymerized unit of cyclic polyolefin such as norbornene-based or polycyclic norbornene-based monomer. Moreover, in addition to said plastic film, it replaces with said plastic film, and the cellulose-type protective layer may be provided in the single side | surface or both surfaces of the transparent base material. As the cellulose-based protective layer, a cellulose-based film, particularly cellulose triacetate or other transparent acetylcellulose-based film is generally used.

  The color correction optical filter of the present invention is a flow coating method, spray method, bar coating method, gravure coating method, roll coating method, blade coating method, air knife coating method, lip coating method, die coater method, etc. on a transparent substrate. After coating the resin composition of the present invention by a known coating method, the film is dried at a temperature of 60 to 140 ° C., preferably 80 to 120 ° C., if necessary (when the resin composition contains a solvent). It is obtained by providing a resin layer having a thickness of 60 μm.

The liquid crystal display device of the present invention includes a color correction optical filter including the resin composition of the present invention. The liquid crystal display device using the color correction optical filter of the present invention is not particularly limited as long as it is a liquid crystal display device, but is preferably a liquid crystal display device using an LED as a light source. By applying the color correction optical filter of the present invention to a liquid crystal display using LEDs as a light source, a liquid crystal display device with improved color reproducibility can be obtained.
The installation position of the color correction optical filter in the liquid crystal display device is not particularly limited as long as it is between the LED light source and the viewer, but viewing of the two polarizing films present in the liquid crystal display is not limited. It is preferable to be installed by being bonded to a polarizing film located on the person side.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples. In the examples, λmax was measured with a spectrophotometer “trade name UV-3150, manufactured by Shimadzu Corporation”. In the following description, “part” is based on mass unless otherwise specified.

Synthesis Example 1 (Synthesis of squarylium compound represented by Compound No. 1)
In a 200 ml four-necked flask equipped with a Dean-Stark apparatus, 0.5 part of 3,4-dihydroxy-3-cyclobutene-1,2-dione (Tokyo Chemical Industry Co., Ltd.) represented by the above formula (F) , 50 parts of toluene, 50 parts of n-butanol and 1.2 parts of 1,2-dimethylindole (manufactured by Tokyo Chemical Industry Co., Ltd.), and refluxed at 100 ° C. for 3 hours while removing water generated as the reaction progressed It was. After the reaction solution was cooled to room temperature, the precipitated crystals were collected by filtration, washed and dried. 1.4 parts of the squarylium compound represented by 1 was obtained.

Synthesis Example 2 (Synthesis of squarylium compound represented by Compound No. 4)
(Step 2-1)
In a 200 ml four-necked flask, 3.3 parts of 2-methylindole (manufactured by Tokyo Chemical Industry Co., Ltd.), 40 parts of tetrahydrofuran, 2.1 parts of potassium hydroxide, 0.5 parts of tetrabutylammonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.) And 5.8 parts of butyl p-toluenesulfonate were added and refluxed for 5 hours. After cooling the reaction solution to room temperature, water was poured into the reaction solution, and the organic layer was washed with water and saturated brine, and dried over anhydrous sodium sulfate. Furthermore, 5.0 parts of intermediate compounds (a) represented by following formula (100) were obtained by concentrating under reduced pressure.

(Process 2-2)
The same operation as in Synthesis Example 1 was performed except that 1,2-dimethylindole in Synthesis Example 1 was changed to 1.7 parts of the intermediate compound (a) obtained in Step 2-1 of Synthesis Example 2. No. in the above specific example. 1.3 parts of squarylium compound represented by 4 was obtained.

Synthesis Example 3 (Synthesis of squarylium compound represented by Compound No. 6)
(Step 3-1)
The same operation as in Step 2-1 of Synthesis Example 2 was performed, except that p-toluenesulfonate butyl in Step 2-1 of Synthesis Example 2 was changed to 7.5 parts of n-octyl p-toluenesulfonate. 6 parts of an intermediate compound (b) represented by the formula (101) was obtained.

(Step 3-2)
The same operation as in Synthesis Example 1 was performed except that 1,2-dimethylindole in Synthesis Example 1 was changed to 2.1 parts of the intermediate compound (b) obtained in Step 3-1 of Synthesis Example 3, and the above No. of specific example. 1.4 parts of the squarylium compound represented by 6 was obtained.

Synthesis Example 4 (Synthesis of squarylium compound represented by Compound No. 7)
(Step 4-1)
The same operation as in Step 2-1 of Synthesis Example 2 was performed except that butyl p-toluenesulfonate in Step 2-1 of Synthesis Example 2 was changed to 5.7 parts of 1-bromodecane (manufactured by Tokyo Chemical Industry Co., Ltd.). Then, 6.5 parts of an intermediate compound (c) represented by the following formula (102) was obtained.

(Step 4-2)
The same operation as in Synthesis Example 1 was performed except that 1,2-dimethylindole in Synthesis Example 1 was changed to 2.3 parts of the intermediate compound (c) obtained in Step 4-1 of Synthesis Example 4. No. in the above specific example. 1.7 parts of squarylium compound represented by 7 was obtained.

Synthesis Example 5 (Synthesis of Compound for Comparative Example)
According to the production method described in paragraph Nos. 0050 to 0051 of Patent Document 4, a comparative compound represented by the following formula (103) was obtained.

No. obtained in Synthesis Examples 1 to 4 The squarylium compound represented by 1, 4, 6 and 7 and the squarylium compound represented by the formula (103) obtained in Synthesis Example 5 are respectively dissolved in an amount of methanol in which the absorbance at the absorption maximum wavelength is 1, The UV-visible absorption spectrum of each methanol solution was measured.
From the measurement result of the UV-visible absorption spectrum, the width of the absorption spectrum at an absorbance of 1/2 (also referred to as half-value width) and the width of the absorption spectrum at an absorbance of 1/8 were calculated. The results are shown in Table 1.

  From the results in Table 1, the above-mentioned No. It is clear that the squarylium compounds represented by 1, 4, 6 and 7 have a narrow UV-visible absorption spectrum of a solution dissolved in methanol and absorb less light in the necessary wavelength region than the comparative compound. It is.

Example 1 (Preparation of resin composition 1 of the present invention)
No. obtained in Synthesis Example 4 7 parts of a copolymer (trade name PTR-104; manufactured by Nippon Kayaku Co., Ltd.) using a polymerizable monomer containing 0.01 part of a squarylium compound represented by 7 and an acrylic acid alkyl ester monomer as a raw material. It melt | dissolved in 12.5 parts of non, and produced the resin composition 1 of this invention.

Example 2 (Preparation of color correction optical filter of the present invention)
An easy-adhesive PET film (trade name: Cosmo Shine A4300; manufactured by Toyobo Co., Ltd.) was coated with the resin composition 1 of the present invention obtained in Example 1 in an amount such that the thickness of the resin layer after drying was 15 μm. After coating, the solvent was removed at a drying temperature of 100 ° C. to obtain the color correction optical filter 1 of the present invention.

(Spectral characteristics of the color correction optical filter of the present invention)
The result of measuring the transmission spectrum of the color correction optical filter 1 of the present invention obtained in Example 2 using a spectroscope (manufactured by Shimadzu Corporation, trade name UV-3150) is shown in FIG. The λmax of the color correction optical filter 1 of the present invention was 586 nm, and had the performance necessary for efficiently absorbing the intermediate wavelength region of R and G of the color filter.

The resin composition of the present invention is excellent in selectively absorbing light in a poor color purity range (λmax 500 to 700 nm, particularly 570 to 610 nm) that is transmitted through the color filter, and the resin composition is used. Thus, it is possible to provide a color correction filter for a liquid crystal display that is excellent in color reproducibility without reducing the brightness of the liquid crystal display.

Claims (6)

A coloring composition for a color correction optical filter used in a liquid crystal display using an LED as a light source, which has the following formula (1)

(In Formula (1), R ¹ and R ² represent an alkyl group having 1 to 10 carbon atoms or a phenyl group, and a plurality of R ¹ may be the same or different from each other, and a plurality of R ² are They may be the same or different.)
The absorption spectrum width at the absorbance A / 2 is 40 nm or less when the absorbance at λmax of the ultraviolet-visible absorption spectrum of the solution dissolved in the solvent is A, and the absorption spectrum width at the absorbance A / 8 is The resin composition containing the squarylium compound which is 100 nm or less, and transparent resin. The resin composition according to claim 1, wherein R ¹ is an alkyl group having 1 to 10 carbon atoms. The resin composition according to claim 1 or 2, wherein the transparent resin comprises a polymer or copolymer using an acrylic acid alkyl ester monomer as a raw material. The acrylic acid alkyl ester monomer is at least one selected from the group consisting of n-butyl (meth) acrylate, t-butyl (meth) acrylate, and methyl (meth) acrylate. Resin composition. A color correction optical filter comprising the resin composition according to claim 1, wherein the color correction optical filter is for a liquid crystal display using an LED as a light source. A liquid crystal display device equipped with the color correction optical filter according to claim 5.

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