JP2006089724A - Red color conversion material composition and red color conversion membrane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a red color conversion material composition having excellent durability and suppressing deterioration of a color conversion membrane when a light source is continuously lit. <P>SOLUTION: The red color conversion material composition comprises (A) a methyl methacrylate-methacrylic acid copolymer and/or a benzyl methacrylate-methacrylic acid copolymer, (B) each fluorescent dye of (b-1) at least one kind of coumarin dye having a specific structure, (b-2) at least one kind of rhodamine dye having a specified structure and (b-3) at least one kind of rhodamine dye having a specific structure and (C) pentaerythritol triacrylate and/or trimethylolpropane triacrylate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a red color conversion material composition and a red color conversion film. More specifically, the present invention relates to a red conversion material composition that can reduce deterioration of a color conversion film when a light source is continuously turned on and has little deterioration with time of color development, and a red conversion film using the same.

  The color conversion film converts light emitted from a light source such as an organic electroluminescence element (hereinafter abbreviated as EL) into light having a longer wavelength and emits light, and is used in combination with a light source. Various display devices are formed.

As the color conversion material composition, for example, Patent Document 1 discloses a color conversion material composition using a basic resin such as a vinylpyridine derivative or an aminostyrene derivative.
Patent Document 2 discloses a color conversion material composition using an ethylenically unsaturated carboxylic acid copolymer.
Further, Patent Document 3 discloses an unsaturated group-containing compound obtained by reacting a reaction product of an epoxy compound with acrylic acid or methacrylic acid with a polybasic acid carboxylic acid or an anhydride thereof, and a fluorescent dye. And a color conversion material composition containing at least one phosphor selected from fluorescent pigments.

  However, in these color conversion material compositions, particularly when the color conversion film containing the rhodamine dye is continuously irradiated with the blue light emission of the organic EL element, the emission intensity from the rhodamine dye deteriorates very quickly. Depending on the composition, rhodamine may be denatured into a leuco body, and the desired luminescence cannot be obtained, and it reacts with rhodamine to increase the viscosity of the composition and impair the processability of the color conversion film. There was a problem.

  In response to this problem, the present inventors disclosed in Patent Document 4 a binder resin (component A) composed of a methacrylic acid ester-methacrylic acid copolymer having a specific structure, and at least one fluorescent dye (component B). The color conversion material composition containing the monomer and / or oligomer (C component) which have a photopolymerizable ethylenically unsaturated group is disclosed. By using this composition, the deterioration of the color conversion film can be reduced, the increase in the viscosity of the composition can be prevented, and the modification of rhodamine can be prevented.

However, there is a demand for a color conversion film that is more durable and can stably develop color even after continuous and long-term use.
Japanese Patent Laid-Open No. 9-208944 JP-A-9-106888 JP 2000-119645 A JP 2003-64135 A

  This invention is made | formed in view of the above-mentioned problem, It aims at providing the red conversion material composition which is more durable and can suppress deterioration of the color conversion film at the time of lighting a light source continuously.

［式中、Ｒ^１及びＲ^２は、直鎖状、分岐状又は環状の炭素数２〜１０のアルキル基を示し、Ｒ^３及びＲ^４は、直鎖状、分岐状又は環状の炭素数２〜８のアルキル基を示す。Ｒ^３及びＲ^４は結合して環を形成してもよい。］

［式中、Ｒ^５及びＲ^６は、直鎖状、分岐状又は環状の炭素数２〜８のアルキル基を示す。Ｘ⁻は、

である。］

［式中、Ｒ^７、Ｒ^９、及びＲ^１０は、直鎖状、分岐状又は環状の炭素数２〜８のアルキル基を示し、Ｒ^８は直鎖状の炭素数４〜８のアルキル基を示す。Ｘ⁻は、

である。］ As a result of further research on the color conversion material composition of Patent Document 4 described above, the present inventor has found that the combination of a specific binder resin, a fluorescent dye, and a photopolymerizable acrylate ester is extremely high. The present inventors have found that a red color conversion material composition having good performance and light resistance can be obtained.
According to the present invention, the following red color conversion material composition and red color conversion film are provided.
1. (A) methyl methacrylate-methacrylic acid copolymer and / or benzyl methacrylate-methacrylic acid copolymer, (B) each of the fluorescent dyes (b-1) to (b-3) shown below, C) A red color conversion material composition comprising pentaerythritol triacrylate and / or trimethylolpropane triacrylate.
(B-1) At least one coumarin dye having a structure of any one of the following formulas (1) to (3) (b-2) At least one rhodamine having a structure of the following formula (4) or (5) Dye (b-3) At least one rhodamine dye having the structure of any one of the following formulas (6) to (9)

[Wherein, R ¹ and R ² represent a linear, branched or cyclic alkyl group having 2 to 10 carbon atoms, and R ³ and R ⁴ represent a linear, branched or cyclic carbon number 2 -8 alkyl groups are shown. R ³ and R ⁴ may combine to form a ring. ]

[Wherein, R ⁵ and R ⁶ represent a linear, branched or cyclic alkyl group having 2 to 8 carbon atoms. X ⁻ is

It is. ]

[Wherein R ⁷ , R ⁹ and R ¹⁰ represent a linear, branched or cyclic alkyl group having 2 to 8 carbon atoms, and R ⁸ represents a linear alkyl group having 4 to 8 carbon atoms. Indicates. X ⁻ is

It is. ]

2. 45% to 65% by weight of the component (A), 0.3% to 5% by weight of the component (B), and (C) the component (A) 2) The red color conversion material composition according to 1, which contains 10 to 200 parts by weight per 100 parts by weight of the component.
3. A red conversion film comprising the red conversion material composition as described in 1 or 2 above.

  Since the red color conversion material composition of the present invention is not easily deteriorated even when the light source is continuously turned on, stable light emission can be obtained for a long time. Therefore, a stable image with little color change with time can be displayed by using it as a red pixel for a full color display or the like.

Hereinafter, the red color conversion material composition and the red color conversion film of the present invention will be specifically described.
The red color conversion material composition of the present invention includes the following components (A) to (C).
(A) Methyl methacrylate-methacrylic acid copolymer and / or benzyl methacrylate-methacrylic acid copolymer (B) Fluorescent dyes of the following (b-1) to (b-3) (b-1) 1) at least one coumarin dye having the structure of (3) (b-2) at least one rhodamine dye having the structure of the following formula (4) or (5) (b-3) the following formula (6) At least one rhodamine dye having a structure of any one of (9) (C) pentaerythritol triacrylate and / or trimethylolpropane triacrylate

［式中、Ｒ^１及びＲ^２は、直鎖状、分岐状又は環状の炭素数２〜１０のアルキル基を示し、Ｒ^３及びＲ^４は、直鎖状、分岐状又は環状の炭素数２〜８のアルキル基を示す。Ｒ^３及びＲ^４は結合して環を形成してもよい。］

[Wherein, R ¹ and R ² represent a linear, branched or cyclic alkyl group having 2 to 10 carbon atoms, and R ³ and R ⁴ represent a linear, branched or cyclic carbon number 2 -8 alkyl groups are shown. R ³ and R ⁴ may combine to form a ring. ]

［式中、Ｒ^５及びＲ^６は、直鎖状、分岐状又は環状の炭素数２〜８のアルキル基を示す。Ｘ⁻は、

である。］

[Wherein, R ⁵ and R ⁶ represent a linear, branched or cyclic alkyl group having 2 to 8 carbon atoms. X ⁻ is

It is. ]

［式中、Ｒ^７、Ｒ^９、及びＲ^１０は、直鎖状、分岐状又は環状の炭素数２〜８のアルキル基を示し、Ｒ^８は直鎖状の炭素数４〜８のアルキル基を示す。Ｘ⁻は、

である。］

[Wherein R ⁷ , R ⁹ and R ¹⁰ represent a linear, branched or cyclic alkyl group having 2 to 8 carbon atoms, and R ⁸ represents a linear alkyl group having 4 to 8 carbon atoms. Indicates. X ⁻ is

It is. ]

Hereinafter, each component will be described.
(A) Methyl methacrylate-methacrylic acid copolymer and / or benzyl methacrylate-methacrylic acid copolymer Methyl methacrylate-methacrylic acid copolymer and / or benzyl methacrylate-methacrylic acid copolymer used in the present invention There is no restriction | limiting in particular, What was generally obtained or what superposed | polymerized by the conventional method can be used.

  The weight average molecular weight (Mw) of the component (A) is preferably in the range of 5,000 to 100,000, and more preferably 10,000 to 50,000. If it is less than 5,000, there exists a possibility that the intensity | strength of the color conversion film formed from a red conversion material composition may become low. On the other hand, when it exceeds 100,000, the viscosity of the color conversion material composition becomes high, and when the color conversion film is formed, thickness unevenness may occur.

  The content of methyl methacrylate units or benzyl methacrylate units in the copolymer is preferably in the range of 0.4 to 0.9 (molar ratio), and in the range of 0.6 to 0.8. Further preferred. If the content is less than 0.4, the patterning accuracy of the color conversion film formed from the color conversion material composition may be reduced. If it exceeds 0.9, patterning may not be possible by photolithography.

  The component (A) is preferably contained in an amount of 45 to 65% by weight, more preferably 50 to 60% by weight, based on the total amount of the red color conversion material composition. If it is less than 45% by weight, there is a risk of causing a problem in the tackiness of the film before the coin.

［式中、Ｒ^１及びＲ^２は、直鎖状、分岐状又は環状の炭素数２〜１０のアルキル基を示し、Ｒ^３及びＲ^４は、直鎖状、分岐状又は環状の炭素数２〜８のアルキル基を示す。Ｒ^３及びＲ^４は結合して環を形成してもよい。］ (B) Fluorescent dye (b-1) Coumarin dye having a specific structure The coumarin dye used in the present invention has a structure of any one of the following formulas (1) to (3).

[Wherein, R ¹ and R ² represent a linear, branched or cyclic alkyl group having 2 to 10 carbon atoms, and R ³ and R ⁴ represent a linear, branched or cyclic carbon number 2 -8 alkyl groups are shown. R ³ and R ⁴ may combine to form a ring. ]

Preferred alkyl groups as R ¹ and R ² include an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, a 2-ethylhexyl group, a cyclohexylmethyl group, and a neopentyl group. In particular, it is preferable that ^one of R ¹ or R ² is a linear alkyl group and the other is a branched or cyclic alkyl group. Thereby, the balance between the solubility and durability of the pigment can be improved.

Preferred alkyl groups as R ³ and R ⁴ include an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, and a 2-ethylhexyl group. In particular, a butyl group and a hexyl group are preferable.

R ³ and R ⁴ may be bonded to each other to form a ring. Examples of the ring include 2-methylpiperidino group, piperidino group, pyrodino group, 2-methylpyrrolidino group and the like. In particular, 2-methylpiperidino group and piperidino group are preferable.

  The compounds of the above formulas (1) to (3) can be synthesized according to known coumarin dye synthesis methods represented by coumarin 6.

(B-2) Rhodamine dye having a specific structure The rhodamine dye used in the present invention has a structure represented by the following formula (4) or (5).

［式中、Ｒ^５及びＲ^６は、直鎖状、分岐状又は環状の炭素数２〜８のアルキル基を示す。Ｘ⁻は、

である。］

[Wherein, R ⁵ and R ⁶ represent a linear, branched or cyclic alkyl group having 2 to 8 carbon atoms. X ⁻ is

It is. ]

Preferred alkyl groups for R ⁵ include ethyl, propyl, butyl, hexyl, isobutyl, octyl and 2-ethylhexyl groups. In particular, an ethyl group, a propyl group, a butyl group, and a hexyl group are preferable.

Preferred alkyl groups for R ⁶ include ethyl, propyl, butyl, hexyl, octyl, 2-ethylhexyl, and cyclohexyl groups. In particular, a butyl group, a hexyl group, and an octyl group are preferable.

  The compounds of the above formulas (4) to (5) can be synthesized according to known rhodamine dye synthesis methods represented by rhodamine 6G.

(B-3) Rhodamine dye having a specific structure The rhodamine dye used in the present invention has a structure of any one of the following formulas (6) to (9).

［式中、Ｒ^７、Ｒ^９、及びＲ^１０は、直鎖状、分岐状又は環状の炭素数２〜８のアルキル基を示し、Ｒ^８は直鎖状の炭素数４〜８のアルキル基を示す。Ｘ⁻は、

である。］

[Wherein R ⁷ , R ⁹ and R ¹⁰ represent a linear, branched or cyclic alkyl group having 2 to 8 carbon atoms, and R ⁸ represents a linear alkyl group having 4 to 8 carbon atoms. Indicates. X ⁻ is

It is. ]

Preferred alkyl groups as R ⁷ include an ethyl group, a propyl group, a butyl group, a hexyl group, an isobutyl group, and a 2-ethylhexyl group. In particular, an ethyl group, a propyl group, a butyl group, and a hexyl group are preferable.

Preferred alkyl groups for R ⁸ include butyl, pentyl, hexyl, heptyl, and octyl groups.

Preferred alkyl groups as R ⁹ and R ¹⁰ include an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, and a 2-ethylhexyl group. In particular, a butyl group and a hexyl group are preferable.

  The compounds of the above formulas (6) to (9) can be synthesized according to a known rhodamine dye synthesis method represented by rhodamine B or according to the description of JP-A No. 2001-164245.

The component (B) is preferably contained in an amount of 0.1 to 10% by weight, more preferably 0.2 to 5% by weight, based on the total amount of the red color conversion material composition. If the concentration is less than 0.1% by weight, the formed color conversion film may not be sufficiently color-converted. If the concentration exceeds 10% by weight, the color conversion efficiency is lowered due to concentration quenching, and high-definition patterning cannot be performed. There is a case.
In addition, the smaller the fluorescent dye contained, the smaller the degree of deterioration of light emission when blue light from a light source is continuously irradiated. Therefore, it is preferable to set the lowest concentration in the concentration range that emits fluorescence most.

The ratio of (b-1) to (b-3) in the component (B) is appropriately adjusted so that the color purity of red is increased.
The ratio of the fluorescent dye (b-1) to the red conversion material composition is preferably 0.1 to 2% by weight, and more preferably 0.5 to 1.0% by weight. preferable.
The proportion of the fluorescent dye in (b-2) is preferably 0.1 to 1.5% by weight, and more preferably 0.2 to 0.7% by weight.
The proportion of the fluorescent dye in (b-3) is preferably 0.1 to 1.5% by weight, and more preferably 0.2 to 0.7% by weight.

(C) Pentaerythritol acrylate and / or trimethylolpropane triacrylate As the pentaerythritol triacrylate and / or trimethylolpropane triacrylate used in the present invention, those commercially available or those synthesized by a conventional method can be used.
Component (C) is preferably contained in an amount of 10 to 200 parts by weight, more preferably 30 to 150 parts by weight, per 100 parts by weight of component (A). When the amount of the component (C) is less than 10 parts by weight, the formed color conversion film may be inferior in solvent resistance, and when it exceeds 200 parts by weight, there is a possibility of causing a problem in tackiness after pre-curing.

  The red color conversion material composition of the present invention preferably contains 0.1 to 15% by weight of a compound having an epoxy group (component D) in addition to the components A to C described above, based on the total amount of the composition. More preferably, the content is 5 to 7% by weight. By containing the D component, the red color conversion material composition of the present invention can suppress an increase in the viscosity of the composition and prevent denaturation of rhodamine. As the component D, a phenol novolac type epoxy compound, a cresol novolac type epoxy compound, or the like can be suitably used. By applying heat after the photopolymerization of the component C, the photocrosslinked product and the epoxy resin of the component D are further added. Crosslinking can increase the crosslink density of the membrane.

  The red conversion material composition of this invention can add a photoinitiator or a sensitizer as needed. This photopolymerization initiator or sensitizer is not only used for the photocuring reaction of the component (A), but also is not photopolymerizable such as a (meth) acrylic monomer or a (meth) acrylic oligomer that is blended as necessary. It is also used as a polymerization initiator for saturated compounds. As the photopolymerization initiator, for example, acetophenones, benzophenones, benzoin ethers, sulfur compounds, anthraquinones, organic peroxides and thiols are preferably used.

Examples of acetophenones include acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, p-t-butylacetophenone, and the like.
Examples of benzophenones include benzophenone, 2-chlorobenzophenone, p, p′-bisdimethylaminobenzophenone, and the like.

Examples of benzoin ethers include benzyl, benzoin, benzoin methyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.
Examples of the sulfur compound include benzylmethyl ketal, thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone and the like.
Examples of anthraquinones include 2-ethylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-diphenylanthraquinone and the like.

Examples of the organic peroxide include azobisisobutylnitrile, benzoyl peroxide, cumene peroxide, and the like.
Examples of thiols include 2-mercaptobenzoxazole and 2-mercaptobenzothiazole.
These photopolymerization initiators and sensitizers can be used alone or in combination of two or more.

  Moreover, although it does not act as a photopolymerization initiator or a sensitizer by itself, a compound that can increase the ability of the photopolymerization initiator or the sensitizer when used in combination with the above-mentioned compounds can be added. Examples of such compounds include tertiary amines such as triethanolamine which are effective when used in combination with benzophenone.

  The amount of the photopolymerization initiator and sensitizer used is not particularly limited, and usually 10 parts by weight or less is preferably used with respect to 100 parts by weight of component (C). When the amount exceeds 10 parts by weight, the light is difficult to reach the inside, so an uncured part is generated, resulting in a decrease in physical properties, for example, poor adhesion between the substrate and the resin, or a decrease in the fluorescence of the dye. Such a problem may occur.

  In the present invention, it is also possible to blend a resin having a large dielectric constant in order to improve the fluorescence yield of the fluorescent dye. Specific examples include melanin resin, phenol resin, alkyd resin, polyurethane resin, polyester resin, polyamide resin oligomer or polymer, polyvinyl alcohol, polyvinyl hydrin, hydroxyethyl cellulose, carboxyl methyl cellulose, aromatic sulfonamide resin, urea resin and benzoguanamine. Examples thereof include transparent resins such as resins. Among these, melanin resin and benzoguanamine resin can be particularly preferably used.

  These resins may be used as long as the properties of the composition of the present invention and the cured product thereof are not impaired, and the amount used is not particularly limited, but is usually 200 with respect to 100 parts by weight of component (A). It is preferable that it is below the weight part. If the amount used exceeds 200 parts by weight, there is a risk of problems in tackiness after precure. The amount is particularly preferably 100 parts by weight or less.

If necessary, the color conversion material composition of the present invention may further contain additives such as a curing accelerator, a thermal polymerization inhibitor, a plasticizer, a filler, a solvent, an antifoaming agent, and a leveling agent.
Examples of the curing accelerator include perbenzoic acid derivatives, peracetic acid, and benzophenones. Examples of the thermal polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, pyrogallol, t-butylcatechol, and phenothiazine. Examples of the agent include dibutyl phthalate, dioctyl phthalate, and tricresyl. Examples of the filler include glass fiber, silica, mica, and alumina. Examples of the antifoaming agent and leveling agent include silicon. Fluorine-based and acrylic-based compounds are preferably used.

  In accordance with the method for producing the color conversion film, the above-described various additive components forming the red conversion material composition can be dissolved in a solvent. Examples of the solvent include ketones, cellosolves, or lactones. Specific examples of the ketones include methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of the cellosolves include methyl cellosolve, ethyl cellosolve, Examples thereof include butyl cellosolve and cellosolve acetate. As the lactone, γ-butyrolactone and the like are preferable.

  The red color conversion material composition of the present invention becomes a red color conversion material composition with extremely high performance and good light resistance by using the above-mentioned specific binder resin, fluorescent dye and photopolymerizable acrylic ester in combination. .

Next, the red conversion film of the present invention will be described.
The red conversion film of the present invention absorbs light from a light source and emits red light having a longer wavelength, and is formed using the above-described red conversion material composition. As a method for forming a film, there is a method of curing the composition or forming it by a photolithography method or the like. In particular, it is preferably formed by a photolithography method.
An example of the method for producing the red color conversion film of the present invention will be described below.

  First, the photosensitive color conversion material composition is applied as a solution to the substrate surface. Next, the solvent is dried by pre-cure (pre-baking), a photomask is applied on the obtained film, and the exposed portion is cured by irradiating with actinic rays. Then, a pattern is formed by performing the development which elutes an unexposed part using weak alkali aqueous solution. After pattern formation, post-baking is performed as post-drying to produce a red conversion film.

The substrate to which the solution of the red color conversion material composition of the present invention is applied is preferably a smooth substrate having a light transmittance in the visible region of 400 to 700 nm of 50% or more. Specifically, a glass substrate or a polymer plate is used.
Examples of the glass substrate include soda lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz.
Examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone.

  As a method for applying the solution of the color conversion material composition to the substrate, any method such as a method using a roller coater machine, a land coater machine, or a spinner machine can be used in addition to the known solution immersion method and spray method. After applying to a desired thickness by these methods, the film is formed by removing the solvent (pre-baking).

Pre-baking is performed by heating with an oven, a hot plate, or the like. The heating temperature and heating time in the pre-baking are appropriately selected according to the solvent to be used, and are performed at a temperature of 80 to 150 ° C. for 1 to 30 minutes, for example. The exposure performed after pre-baking is performed by an exposure machine, and only the resist corresponding to the pattern is exposed by exposing through a photomask. The exposure machine and exposure irradiation conditions can be selected as appropriate, and as the light to be irradiated, for example, visible light, ultraviolet light, X-rays, electron beams and the like can be used. The irradiation amount is not particularly limited, but is selected in the range of, for example, 1 to 3000 mJ / cm ² .

  The alkali development after the exposure is performed for the purpose of removing the resist in the unexposed portions, and a desired pattern is formed by this development. As a developer suitable for this alkali development, for example, an aqueous solution of an alkali metal or alkaline earth metal carbonate can be used. In particular, development is performed at a temperature of 10 to 50 ° C., preferably 20 to 40 ° C. using a weakly alkaline aqueous solution containing 1 to 3% by weight of a carbonate such as sodium carbonate, potassium carbonate or lithium carbonate. A fine image can be accurately formed using a developing machine, an ultrasonic cleaning machine, or the like.

  After the development as described above, heat treatment (post-bake) is usually performed under conditions of 80 to 220 ° C. and 10 to 120 minutes. This post-baking is performed in order to improve the adhesion between the patterned color conversion film and the substrate. This is performed by heating with an oven, a hot plate or the like, as in the pre-baking. The patterned color conversion film of the present invention is formed by a so-called photolithography method through the above steps.

  The film thickness of the color conversion film of the present invention needs to be appropriately selected as the film thickness necessary for converting the incident light from the light source into a desired wavelength, but is usually selected in the range of 1 to 100 μm. A film thickness of 1 to 20 μm is particularly preferable.

Hereinafter, the present invention will be described more specifically with reference to examples.
Example 1
(1) Synthesis of methyl methacrylate-methacrylic acid copolymer (component A) 10 g of methyl methacrylate, 2.5 g of methacrylic acid, and 0.12 g of azobisisobutyronitrile were dissolved in 30 g of toluene and replaced with nitrogen gas. The mixture was heated and stirred at 80 ° C. for 2 hours, and then heated and stirred at 100 ° C. for 1 hour. After cooling to room temperature, the mixture was concentrated under reduced pressure. The residue was poured into methanol and precipitated to obtain a methyl methacrylate-methacrylic acid copolymer (component A) (yield 95%). The weight average molecular weight was 20,000, and the methyl methacrylate unit content (molar ratio) was 0.78 as determined by NMR measurement.

(2) Synthesis of rhodamine dye represented by formula (4-A) 1,2-dichlorobenzene (31.2 parts by weight), zinc chloride (1.14 parts by weight), neopentylamine (1.00 parts by weight) 3,6-dichloro-2,7-di-n-hexylfluorane (1.29 parts by weight) was added, and the mixture was stirred and reacted at 170 ° C. for 25 hours. After cooling the reaction mixture to 100 ° C., steam distillation was performed, and 48% sodium hydroxide (1.29 parts by weight) and toluene (44.6 parts by weight) were added to the distillation residue. The organic layer was separated, washed and concentrated to obtain a crude product. By recrystallizing this crude product from a toluene / hexane mixed solvent, 2,7-di-n-hexyl-3,6-di- (neopentylamino) fluorane was obtained in a yield of 0.987 parts by weight and a yield of 64%. It was.

  The obtained 2,7-di-n-hexyl-3,6-di- (neopentylamino) fluorane (1.00 parts by weight) was dissolved in 31.2 parts by weight of ethanol, and hydrochloric acid was heated under reflux. Gas was blown in. Toluene was added to the reaction mixture for extraction, and the toluene layer was washed and concentrated to obtain a crude product. The crude product was purified by silica gel column chromatography to obtain 0.538 parts by weight of a fluorane compound ethyl ester chloride in a yield of 48%.

  This ethyl ester (1.00 part by weight) was dissolved in 11.7 parts by weight of methanol, and an aqueous perchloric acid solution (1.92 parts by weight) was added and stirred. The reaction mixture was discharged into water, and the resulting dark red precipitate was collected by suction filtration to obtain the desired dye compound in a yield of 1.07 parts by weight, a yield of 97%, and a purity of 98% (LC).

  (3) 1.9 g of the methyl methacrylate-methacrylic acid copolymer synthesized above, (b-1), 23 mg of a coumarin fluorescent dye of the following formula (3-A), and (b-2) of the following formula (4) -A) Rhodamine fluorescent dye 10 mg, (b-3) as rhodamine fluorescent dye 10 mg of the following formula (7-A), and pentaerythritol triacrylate (Aronix M-305, manufactured by Toagosei Co., Ltd.) as component C 4 g of a photopolymerization initiator (manufactured by Ciba Specialty Chemicals Co., Ltd., Irgacure 907) was dissolved in 5.0 g of 2-acetoxy-1-methoxypropane to obtain a red conversion material composition solution.

In the formula, Et represents an ethyl group, and Bu represents an n-butyl group.
1 ml of this solution was applied onto a 50 mm × 50 mm glass substrate by a spin coater. The conditions at this time were a rotation speed of 1000 rpm and a processing time of 10 seconds.
The coating film was dried using a hot plate at 120 ° C. and then cured by irradiation with ultraviolet light of 365 nm at 300 mJ / cm ² . Then, the red conversion film was produced by post-curing (200 degreeC, 1 hour) using oven.
Table 1 shows the composition of Example 1 and Examples 2 to 4 described later, and Table 2 shows the composition of Comparative Examples 1 and 2.

Examples 2 to 4 Comparative Examples 1 and 2
A red conversion film was produced in the same manner as in Example 1 except that the materials used for each component were changed as shown in Table 1.
The benzyl methacrylate-methacrylic acid copolymer was synthesized by the method described in JP-A No. 2003-64135.

In the formulas (4-B) and (11), Hex represents an n-hexyl group.
About the red conversion film produced in each example, a colored organic EL device using a blue organic EL device having a peak wavelength at 470 nm shown in FIG. 1 was formed, and relative fluorescence intensity and durability were evaluated by the following methods. .
1 includes a glass substrate 1, a color conversion film 2, an anode 3, an organic EL light emitting layer 4, and a cathode 5 when viewed from the light extraction side. Since the organic EL light emitting layer 4 is easily deteriorated in the presence of moisture and oxygen, the organic EL light emitting layer 4 is sealed using the counter glass substrate 7 from the sealing material 6 and the cathode 5 side so as to cover all the element portions including the color conversion film. It has stopped.

(1) Evaluation of Relative Fluorescence Intensity of Red Conversion Film A color conversion film is superimposed on a blue organic EL element having a peak wavelength at 470 nm, and a spectrum of transmitted light obtained through the color conversion film is measured with a spectral luminance meter (Minolta). CS1000) and measured twice in the visual field. And the relative fluorescence intensity of the color conversion film was computed with the following formula, compared with the emission spectrum of a blue organic EL element.
Relative fluorescence intensity = (peak intensity of transmitted light obtained through color conversion film) / (peak intensity of blue organic EL element)

(2) Durability evaluation of color conversion film A 1,000 hour continuous lighting test was performed, and the relative fluorescence intensity of the red conversion film before and after the test was compared. The durability of the color conversion film itself was evaluated.
Performance retention rate = (1,000 hours of continuous lighting relative fluorescence intensity / initial relative fluorescence intensity) × 100
In the colored organic EL element of FIG. 1, since the organic EL light emission itself, which is excitation light, has a certain half life, it is difficult to measure the temporal change in fluorescence of the color conversion film itself. Therefore, a blue LED having a peak at a wavelength of 470 nm was used as an excitation light source for the continuous lighting test, and a color conversion film was disposed so as to be in contact with the light source in a dry nitrogen atmosphere. And after lighting blue LED continuously at 400 nits for 1,000 hours, the color conversion organic film after a test was used and the colored organic EL element shown in FIG. 1 was comprised, and the relative fluorescence intensity was measured.
Table 3 shows the measurement results.

  As is clear from the evaluation results, the red conversion films of Examples 1 to 4 have high initial relative fluorescence intensity and high performance retention, whereas the red conversion film of Comparative Example 1 has high initial relative fluorescence intensity. However, the performance retention was low, and the red relative conversion film of Comparative Example 2 had a low initial relative fluorescence intensity.

  Since the red conversion film obtained from the red conversion material composition of the present invention suppresses the deterioration of the color conversion film even when the light source is continuously turned on, the change in emission color with time is small. Therefore, the red color conversion film of the present invention can be suitably used as a color conversion film for forming a full color display device in combination with a light source such as an organic EL element or a light emitting diode element.

It is a schematic diagram which shows the cross section of a colored organic EL element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Red conversion film 3 Anode 4 Organic electroluminescent light emitting layer 5 Cathode 6 Sealing material 7 Opposite glass substrate

Claims (3)

(A) methyl methacrylate-methacrylic acid copolymer and / or benzyl methacrylate-methacrylic acid copolymer;
(B) Each of the fluorescent dyes (b-1) to (b-3) shown below,
(C) A red color conversion material composition comprising pentaerythritol triacrylate and / or trimethylolpropane triacrylate.
(B-1) At least one coumarin dye having a structure of any one of the following formulas (1) to (3) (b-2) At least one rhodamine having a structure of the following formula (4) or (5) Dye (b-3) At least one rhodamine dye having the structure of any one of the following formulas (6) to (9)

[Wherein, R ¹ and R ² represent a linear, branched or cyclic alkyl group having 2 to 10 carbon atoms, and R ³ and R ⁴ represent a linear, branched or cyclic carbon number 2 -8 alkyl groups are shown. R ³ and R ⁴ may combine to form a ring. ]

[Wherein, R ⁵ and R ⁶ represent a linear, branched or cyclic alkyl group having 2 to 8 carbon atoms. X ⁻ is

It is. ]

[Wherein R ⁷ , R ⁹ and R ¹⁰ represent a linear, branched or cyclic alkyl group having 2 to 8 carbon atoms, and R ⁸ represents a linear alkyl group having 4 to 8 carbon atoms. Indicates. X ⁻ is

It is. ]   45% to 65% by weight of the component (A), 0.3% to 5% by weight of the component (B), and (C) the component (A) 2) The red color conversion material composition according to claim 1, comprising 10 to 200 parts by weight per 100 parts by weight of the component.   A red conversion film comprising the red conversion material composition according to claim 1.

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