JP2006310136A - Red conversion filter, its patterning method, multi-color conversion filter containing the red conversion filter and organic el display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color conversion layer with excellent durability having high color conversion efficiency and suppressing a reaction of fluorescent dye in an excited state and a resin which is one of key factors reducing durability of the color conversion layer with high probability, and to provide a color conversion filter using it. <P>SOLUTION: This red conversion filter comprises a transparent supporting substrate and the color conversion layer comprising at least two layers including a first color conversion layer and a second color conversion layer. The first color conversion layer contains at least one kind of rhodamine dye and a silicone polymer or a resin modified silicone polymer, and the second color conversion layer contains at least one kind of coumarin dye. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a red color conversion filter excellent in light resistance and a patterning method thereof. The present invention also relates to a multicolor conversion filter and an organic EL display that include the red color conversion filter and enable multicolor display with high definition, excellent environmental resistance, and excellent productivity. The red color conversion filter, the multicolor conversion filter and the organic EL display of the present invention include an image sensor, a personal computer, a word processor, a facsimile, a television, an audio, a video, a car navigation system, a vehicle display device, a telephone, a portable terminal, and an industrial measuring instrument. It can also be used for medical display devices.

  The full-color display manufacturing method using electroluminescent elements includes the “three-color light emitting method” in which red, blue, and green light emitting elements are arranged by applying an electric field, and white light emission is cut with a color filter. "Color filter method" that expresses red, blue, and green, and fluorescent dye that absorbs near-ultraviolet light, blue light, blue-green light, or white light and performs wavelength distribution conversion to emit light in the visible light range A “color conversion method” has been proposed that uses a filter as a filter.

  Among them, the color conversion method can achieve high color reproducibility and efficiency, and unlike the three-color light emission method, it is said that the difficulty of making a large screen is low because the electroluminescent element may be a single color. Promising as a candidate for next generation display.

  As a color conversion layer used in a color conversion system, a structure in which one or more fluorescent dyes are dispersed in a resin (hereinafter referred to as “mixed type”; see Patent Document 1), a plurality of types of fluorescent dyes are separately resinized To form a pigment particle, a structure in which the plurality of pigment particles are dispersed in a resin (hereinafter referred to as “pigmented mixed type”; see Patent Document 2), and each of a plurality of fluorescent dyes are separately provided. A structure in which a layer containing one kind of dye is dispersed in a resin and the layers are laminated (hereinafter referred to as “lamination type”; see Patent Document 3) has been proposed.

  The requirements necessary for applying the color conversion filter to the display include high stability as well as high color reproducibility and efficiency. However, in a color conversion layer in which a fluorescent dye, which is an organic substance, is dispersed in a polymer resin, it is known that the tendency brightness of the fluorescent dye decreases with irradiation of light having a wavelength that excites the pigment ( (See Patent Document 4). This phenomenon is caused by the fact that the dye in the excited state does not fluoresce and transition to the ground state, but the dye in the excited state reacts with the polymer resin component to deactivate, or the dye in the excited state (or It is presumed that this is caused by the fact that the decomposition product of the dye) reacts with a healthy dye and deactivates. The reaction between the dye and the resin occurs when there are many highly reactive sites (such as unsaturated functional groups) in the resin. On the other hand, the reaction between the dyes occurs in a situation where even if the resin is inactive, the interaction between the dye and the resin is weak and the dyes tend to aggregate near each other, or in a region where the dye concentration is high.

JP 2000-230172 A Japanese Patent Laid-Open No. 08-286033 Japanese Patent Laid-Open No. 11-066751 Japanese Patent No. 2795932 JP 2000-212554 A Japanese Patent Laid-Open No. 08-005829 JP 07-333418 A

  Since the strength of interaction between the dye and the resin varies greatly depending on the dye and resin used, it is difficult to stably disperse a plurality of dyes in one kind of resin as in the mixed color conversion layer. The types of dyes and resins that can be used are greatly limited.

  On the other hand, in the case of a laminated color conversion layer, there is an advantage that an optimum resin can be selected for each of a plurality of fluorescent dyes, but an attempt is made to achieve film thickness and color conversion characteristics equivalent to those of a mixed color conversion layer. Then, it is necessary to increase the concentration of each fluorescent dye. Specifically, the color conversion characteristics equivalent to those of a mixed color conversion layer having a thickness of 10 μm in which dye A and dye B are dispersed will be achieved by a two-layer color conversion layer having a thickness of 5 μm. In this case, for each of the dye A and the dye B, the same amount as in the mixed type is dispersed in a layer having a film thickness of ½, and the dye concentration in the unit volume is doubled. This increase in the dye concentration causes a reaction between the dyes. In the case of a stacked color conversion layer, it is necessary to perform patterning (for example, by a photolithography method) on each layer to be stacked, which may increase the number of steps and thus increase the manufacturing cost.

  In the case of a pigmented curable color conversion layer, it is necessary to maintain the concentration of the dye in the resin used for pigmentation at a low level in order to suppress the reaction between the dyes. In order to further disperse such pigment particles in the resin, the film thickness of the color conversion layer increases in order to obtain equivalent color conversion characteristics. This increase in the thickness of the color conversion layer may adversely affect the viewing angle dependency when used as a display.

  Further, for the purpose of preventing the deactivation of the fluorescent dye, a structure in which fine particles of an inert material including a fluorescent dye are dispersed in a polymer resin has been proposed (see Patent Document 5). However, even in this structure, the reaction between the fluorescent dye and the resin near the surface of the fine tooth teeth has not been completely prevented, and for applications requiring durability of tens of thousands of hours, such as large-screen TVs. At present, a color conversion layer having sufficient durability cannot be realized.

  Therefore, an object of the present invention is to suppress the reaction between the excited fluorescent dye and the resin, which is one of the main factors that reduce the durability of the color conversion layer, with a high probability, and to provide a color conversion layer excellent in durability. It is to provide a color conversion filter using the same.

  As a result of intensive studies in view of the above-mentioned problems, the present inventors are able to stably disperse rhodamine dyes for the purpose of wavelength conversion from yellow to red in a silicone polymer or a resin-modified silicone polymer at a high concentration. I found. Moreover, since the coumarin type | system | group pigment | dye aiming at wavelength conversion from blue to yellow has low compatibility with a silicone polymer and a resin modified silicone polymer, it was disperse | distributed in the polymer resin with higher compatibility. Therefore, the red color conversion filter according to the first embodiment of the present invention includes a transparent support substrate and a color conversion layer including at least two layers including a first color conversion layer and a second color conversion layer. The one color conversion layer includes at least one rhodamine dye and a silicone polymer or a resin-modified silicone polymer, and the second color conversion layer includes at least one coumarin dye. In the second color conversion layer, a non-photosensitive thermosetting resin, a thermoplastic resin, or a photocurable resin can be used as the polymer resin for dispersing the coumarin dye. Since the coumarin dye is weak to radicals generated during patterning by a photo process and easily decomposes, the resin used for the second color conversion layer must be a non-photosensitive thermosetting resin or a thermoplastic resin. Is desirable.

  Furthermore, when the red color conversion filter of the first embodiment is patterned with high definition, the first color conversion layer is patterned by wet etching or dry etching using the second color conversion layer as an upper layer as a mask. As a result, the manufacturing process can be simplified. That is, in the patterning method for a red color conversion filter according to the second embodiment of the present invention, a first layer containing at least one rhodamine dye and a silicone polymer or a resin-modified silicone polymer is formed on a transparent support substrate. Forming a second color conversion layer having a predetermined pattern shape on the upper surface of the first color conversion layer and including at least one coumarin dye; and using the second color conversion layer as a mask And patterning the first layer to form a first color conversion layer. Here, the step of forming the second color conversion layer may include a step of printing a composition containing at least one type of coumarin dye using a printing method. Alternatively, in the step of forming the second color conversion layer, the second layer is formed by applying a composition containing at least one coumarin dye and a photocurable resin to the entire upper surface of the first layer. And a step of patterning the second layer to form a second color conversion layer having a predetermined pattern shape.

  The multicolor conversion filter according to the third embodiment of the present invention includes a transparent support substrate and subpixels having at least three output wavelength distributions that are separated and arranged, and having a first output wavelength distribution. The pixel includes a first color conversion layer including at least one rhodamine dye and a silicone polymer or a resin-modified silicone polymer, a second color conversion layer including at least one coumarin dye, and a second output. A sub-pixel having a wavelength distribution includes the second color conversion layer. That is, the subpixel having the first output wavelength distribution of the present embodiment is configured by the red color conversion filter of the first embodiment. In the present embodiment, the second color conversion layer may further include a non-photosensitive thermosetting resin or thermoplastic resin, or may further include a photocurable resin.

  An organic EL display according to a fourth embodiment of the present invention includes the multicolor conversion filter according to the third embodiment and an organic EL element having a transparent electrode, an organic EL layer, and a reflective electrode.

  By adopting the above configuration, the red conversion filter of the present invention uses a matrix resin optimized for each of the rhodamine dye and the coumarin dye, and in particular, the color conversion efficiency of the color conversion layer containing the rhodamine dye. In addition, by improving durability, high color conversion efficiency and durability are realized as a whole. Furthermore, high color conversion efficiency and durability can be realized also in a multicolor conversion filter having the red color conversion filter as a partial structure and an organic EL display using the multicolor conversion filter. Further, high-definition patterning of the red color conversion filter can be performed with a simple process.

  A red color conversion filter according to the first embodiment of the present invention is shown in FIG. A red conversion filter, a transparent support substrate 1, and a color conversion layer including at least two layers including the first color conversion layer 3 and the second color conversion layer 5, and the first color conversion layer 3 includes at least one kind The rhodamine dye and a silicone polymer or a resin-modified silicone polymer, and the second color conversion layer 5 contains at least one coumarin dye. Here, the first color conversion layer 3 is disposed closer to the support substrate 1 than the second color conversion layer 5.

[Transparent support substrate 1]
The transparent support substrate 1 is excellent in visible light transmittance, and may be any material that does not cause deterioration in performance of the color conversion filter or the multicolor light emitting device in the process of forming the color conversion filter and the multicolor light emitting device. Examples include a glass substrate, various plastic substrates, and various films.

[First color conversion layer 3]
The rhodamine dye used in the first color conversion layer 3 is a dye containing a rhodamine skeleton (wherein X represents O or S) as a partial structure. The first color conversion layer 3 is a layer that absorbs light in the blue-green to green region and converts the wavelength distribution to emit light in the red region.

  Examples of rhodamine dyes that emit fluorescence in the red region that can be used in the present invention include rhodamine B, rhodamine 6G, rhodamine 3B, rhodamine 101, rhodamine 110, sulforhodamine, basic violet 11, and basic red 2.

  If necessary, the first color conversion layer 3 may be a cyanine dye, 1-ethyl-2- [4- (p-dimethylaminophenyl) -1,3-butadienyl] -pyridium-perchlorate (pyridine 1), or the like. A non-rhodamine dye such as pyridine dye or oxazine dye may be further included. Furthermore, various dyes (direct dyes, acid dyes, basic dyes, disperse dyes, etc.) can be added to the first color conversion layer on the condition that they are fluorescent.

  Hereinafter, the straight silicone polymer and the modified resin silicone polymer that can be used as the matrix of the first color conversion layer 3 will be described in detail.

  The straight type silicone polymer is composed of only silicone as the active ingredient. Like other silicone products, it has -Si-O-Si- bond as the main chain, and alkyl group such as methyl group or aromatic group such as phenyl group. Has a group in the side chain. After curing, there are advantages such as a very high crosslinking density, a three-dimensional crosslinked structure, and a hard film.

The straight type silicone polymer is obtained by dehydration condensation polymerization using a silane derivative represented by the following formula (IV) as a monomer, and has a branched structure. Here, in the monomer (IV), by containing many trifunctional monomers (in the case of n = 1) and tetrafunctional monomers (in the case of n = 0), a branched structure is developed, Crosslinking density can be improved.
_{X n Si (OR) 4-} n (IV)

  In the formula, X represents a methyl group or a phenyl group, and R represents a hydrogen atom, an alkyl group, an aryl group, or an aryl group which may have a substituent. When a plurality of X and R are present in the monomer of formula (IV), X and R may be the same or different. An integer of n = 0 to 2, preferably n = 1 to 2, is desirable. In general, as n decreases, the number of cross-linking sites increases and the hardness also increases.

The obtained straight silicone polymer is a polymer containing structural units of the following formulas (I), (II) and / or (III) (wherein R _{1 to} R ₃ are each an alkyl group or a phenyl group) ). The straight type silicone polymer may contain a plurality of structural units of the formulas (I) to (III).

The methylsilicone polymer in which R _{1 to} R ₃ are methyl groups is a polymer formed from the monomer of formula (IV) in which X is a methyl group. The methylsilicone polymer can contain a large amount of silanol group Si—OH obtained by hydrolysis of Si—OR in the monomer (IV), and has an affinity for water-alcohol. Such a methyl silicone-based polymer forms an extremely hard film by combining silica sol or alumina sol in a solution, and is used as a hard coating agent for plastic surface hardening. The phenyl silicone polymer in which R _{1 to} R ₃ are phenyl groups is a polymer formed from the monomer of the formula (IV) in which X is a phenyl group, and has excellent film strength as compared with methyl silicone polymers. Have.

  Specific examples of the straight silicone resin include KP-854, KP-64, X-12-2206, X-12-2396, X-12-2397 (manufactured by Shin-Etsu Chemical Co., Ltd.), SH804, SH805, There are SH806A, SH840, SR2400 (manufactured by Toray Dow Corning Silicone Co., Ltd.), but is not limited thereto.

  In general, the resin-modified silicone polymer is obtained by block copolymerization or graft copolymerization of a crosslinked silicone and an organic resin, or by polycondensation via an ether bond. More specifically, an organic resin having a reactive functional group such as —OH group, —COOH group, —O— (epoxy) group, and various molecular weights, relatively many silanol groups, methoxy groups, etc. It is a reaction product with a silicone resin having an alkoxy group. As the organic resin, acrylic resin, urethane resin, epoxy resin, alkyd resin, polyester resin, polystyrene resin, polyacrylonitrile resin, polycarbonate resin, or the like can be used.

  Resin-modified silicone polymers combine the properties of organic resins such as flexibility, adhesion, water resistance, film formation, and electrical insulation, in addition to the excellent heat resistance and environmental stability of silicone resins. Known as an organic-inorganic hybrid material, specifically, an imide-modified silicone resin (see Patent Document 6), a silicone-modified polyester resin (see Patent Document 7), and the like have been proposed. The resin-modified silicone polymer is useful as a matrix that is compatible with both ionic and non-ionic dyes. However, since the organic resin reacts with the dye in the excited state and deactivates the dye function, the addition amount should be kept to a minimum. Specifically, the solid content ratio based on the total weight of the polymer is preferably about 5% by weight to 30% by weight.

  As an example, after preparing an organic resin using a monomer having an alkoxysilyl group, the alkoxysilyl group is reacted with the monomer of the formula (IV) to obtain a resin-modified silicone polymer. It can also be formed. Here, the alkoxysilyl group may have 1 to 3 alkoxy groups.

Alternatively, generally, organic and inorganic hybridization can be easily performed by using a silane compound having a structure represented by the following formula (V), which is called a silane coupling agent.
Y _n Si (OR) _4-n (V)

  Here, Y is an organic group having a substituent capable of reacting with an organic resin such as a mercapto group, an azide group, an amino group, an epoxy group, an acrylic group, a methacryl group, an acryloxy group, or a methacryloxy group, and R is a hydrogen atom An atom, an alkyl group, an aryl group, or an aryl group which may have a substituent is represented. n shows the integer of 1-3, Preferably it is 2-3. First, the organic resin and the silane compound of formula (V) are reacted at the substituent on Y, and then bonded to the silicone resin by the Si-OR group derived from formula (V).

  As an example of these silane compounds having the structure of the formula (V), for example, SH6020, SZ6030, SH6040, SZ6075 (manufactured by Toray Dow Corning Silicone Co., Ltd.), etc., which are commercialized by several companies are used. However, it is not limited to these.

  Specific examples of the resin-modified silicone polymer include SR2107, SR2115, SR2145 (manufactured by Toray Dow Corning Silicone Co., Ltd.), but are not limited thereto.

  The first color conversion layer 3 can be formed by any method known in the art such as spin coating, dip coating, air knife coating, curtain coating, roller coating, wire bar coating, and gravure coating. The method can be used by applying a coating mixture comprising at least one rhodamine dye and a silicone polymer or resin-modified silicone polymer on a transparent support substrate. When the patterning of the first color conversion layer 3 is required, it can be carried out by performing patterning using an ordinary method such as photolithography after coating. Alternatively, the first color conversion layer 3 having a predetermined pattern may be formed from the above-described coating mixture using a printing method such as screen printing or ink jet printing.

[Second color conversion layer 5]
The coumarin dye used in the second color conversion layer 5 is a dye containing a coumarin skeleton as a partial structure. The second color conversion layer 5 is a layer that absorbs light in the blue to blue-green region and converts the wavelength distribution to emit light in the green region.

  Examples of the coumarin-based dye that emits fluorescence in the green region that can be used in the present invention include 3- (2′-benzothiazolyl) -7-diethylaminocoumarin (coumarin 6) and 3- (2′-benzoimidazolyl) -7-N. , N-diethylaminocoumarin (coumarin 7), 3- (2′-N-methylbenzimidazolyl) -7-N, N-diethylaminocoumarin (coumarin 30), 2,3,5,6-1H, 4H-tetrahydro-8 -Including trifluoromethylquinolidine (9,9a, 1-gh) coumarin (coumarin 153) and the like.

  If necessary, the second color conversion layer 5 may further include a non-coumarin dye such as a naphthalimide dye such as Solvent Yellow 11 and Solvent Yellow 116. Furthermore, various dyes (direct dyes, acid dyes, basic dyes, disperse dyes, etc.) can be added to the second color conversion layer 5 on the condition that they are fluorescent.

  The second color conversion layer 5 can be formed using a non-photosensitive thermosetting resin, a thermoplastic resin, or a photocurable resin as a matrix. It is more preferable to use a non-photosensitive thermosetting resin or a thermoplastic resin as a matrix to suppress decomposition of the coumarin dye dispersed therein by radicals. When using a photocurable resin that is photosensitive as a matrix, the polymerization initiator and reactive unsaturated functional groups remaining after curing should be reduced to a sufficiently low level to suppress the decomposition of the coumarin dye. is there. In addition, when using a thermosetting resin and a photocurable resin, it is a cured product of these resins that functions as a matrix in the completed red conversion filter.

  Non-photosensitive thermosetting resins that can be used in the second conversion layer 5 are epoxy resins, phenol resins, urethane resins, acrylic resins, vinyl ester resins, imide resins, urethane resins, urea resins, melamine resins. Etc. These resins may further contain a thermosetting initiator that initiates curing by heating, or a crosslinking agent for crosslinking between the resins.

  The thermoplastic resin that can be used in the second color conversion layer 5 is polycarbonate (PC), polyethylene terephthalate (PET), polyethersulfone, polyvinyl butyral, polyphenylene ether, polyamide, polyetherimide, norbornene resin, acrylic. Including resin, methacrylic resin, isobutylene maleic anhydride copolymer resin, cyclic olefin resin and the like.

  The photocurable resin that can be used in the second color conversion layer 5 may be a resin that starts curing only by light irradiation, or it is a so-called one that starts curing by receiving light irradiation and heating. A photothermal combination type curable resin may be used. Specifically, the photocurable or photothermal combination curable resin that can be used in the present invention includes (1) an acrylic polyfunctional monomer and oligomer having a plurality of acroyl groups and methacryloyl groups, and a photo or thermal polymerization initiator. (2) a composition comprising polyvinyl cinnamate and a sensitizer (cured by dimerization or crosslinking), (3) a chain Or a composition comprising a cyclic olefin and a bisazide (nitrene is generated from the bisazide to crosslink the olefin); (4) a composition comprising a monomer having an epoxy group and a photoacid generator (acid generated from a photoacid generator ( Polymerized and cured by cations). In particular, the acrylic photocurable or photothermal combination curable resin (1) can be patterned with high definition, and is preferable in terms of reliability such as solvent resistance and heat resistance.

  The second color conversion layer 5 is composed of a composition containing at least one coumarin-based dye and a matrix selected from a thermoplastic resin, a non-photosensitive thermosetting resin, or a photocurable resin. A predetermined pattern shape or the entire upper surface of the first color conversion layer 3 can be formed by using a printing method such as jet printing. When using a photocurable resin (particularly a photocurable resin that can be used as a photoresist) as a matrix, the photomask is applied after applying the above-described composition to the entire surface of the first color conversion layer 3 by the application method described later. The second color conversion layer 5 having a predetermined pattern shape may be formed by performing patterning by position-selective curing through exposure.

  Alternatively, when forming the second color conversion layer 5 formed on the entire upper surface of the first color conversion layer 3, a spin coating method, a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, You may implement by apply | coating the above-mentioned composition on the 1st color conversion layer 3 using arbitrary methods known in the said techniques, such as a wire bar coat method and a gravure coat method.

  A patterning method for a red color conversion filter according to a second embodiment of the present invention is a patterning method for a red color conversion filter using a photocurable resin as a matrix of a second color conversion layer, and (1) on a transparent support substrate A step of forming a first layer comprising at least one rhodamine dye and a silicone polymer or a resin-modified silicone polymer; (2) comprising at least one coumarin dye on the upper surface of the first color conversion layer; Forming a second color conversion layer having a predetermined pattern shape; and (3) patterning the first layer using the second color conversion layer as a mask to form a first color conversion layer. Including.

  The formation of the first layer in step (1) is known in the art such as spin coating, dip coating, air knife coating, curtain coating, roller coating, wire bar coating, and gravure coating. It can be carried out by applying the application mixture using any method.

  The formation of the second color conversion layer 5 having a predetermined shape in the step (2) is performed by using (2a) a step of printing a composition containing at least one coumarin-based dye by using a printing method. Also good. Alternatively, (2b) a step of applying a composition containing at least one coumarin dye and a photocurable resin to the entire upper surface of the first layer to form a second layer; and (2c) a second layer. And a step of forming a second color conversion layer having a predetermined pattern shape.

  The formation of the second color conversion layer 5 having a predetermined pattern shape in the step (2a) is selected from at least one coumarin dye, a thermoplastic resin, a non-photosensitive thermosetting resin, or a photocurable resin. The composition containing the matrix can be carried out by printing at a predetermined position on the upper surface of the first layer using a printing method such as screen printing or ink jet printing.

  The step of forming the second layer on the entire upper surface of the first layer in the step (2b) is performed by applying a composition containing at least one coumarin dye and a photocurable resin to a spin coating method, a dip coating method, an air knife. The coating can be carried out by applying by any method known in the art, such as a coating method, a curtain coating method, a roller coating method, a wire bar coating method, or a gravure coating method. The photocurable resin used in this step is more preferably a resin that can be used as a photoresist in order to enable high-definition patterning in the later-described step (2c).

  In the patterning of the second layer in the step (2c), for example, the second layer is exposed using a mask having an opening of a predetermined pattern, the photocurable resin at the position corresponding to the opening is cured, It can be carried out by removing the exposed portion to obtain a second color conversion layer having a predetermined pattern. The light source used for exposure depends on the type of the photocurable resin, but any light source known in the art such as a mercury lamp or a laser can be used. In addition, when the photocurable resin is a photothermal combination curable resin, it is desirable that the resin be completely cured by heating after removal of the unexposed portion.

  The patterning of the first layer in the step (3) can be performed, for example, by dry etching such as plasma etching or ion beam etching, or wet etching using the second color conversion layer having a predetermined pattern as a mask. . It is preferable to use dry etching. In the case of using non-selective etching that simultaneously etches not only the first layer but also the second color conversion layer used as a mask, the second layer (that is, the second color conversion layer used as a mask) is used as a completed red conversion filter. It may be formed thicker than the thickness of the second color conversion layer. In this case, when the portion of the first layer not covered with the second color conversion layer is completely removed, the thickness of the remaining second color conversion layer becomes the thickness of the red conversion filter finished product. It is preferable to set the etching conditions as described above.

  By adopting the method of this embodiment, patterning of the first layer using an optical tool (mask, patterned resist, etc.) can be omitted. Further, when the second layer is formed, the first layer is not patterned, and the upper surface thereof is flat. Therefore, the second layer can be patterned with high definition, and the first layer is patterned. The necessity of forming the second layer while aligning with the pattern of the first layer, which may be necessary if it has been done, can also be eliminated. Therefore, the method of the present embodiment is effective for simplifying the manufacturing process and thus reducing the manufacturing cost.

  The multicolor conversion filter according to the third embodiment of the present invention has a transparent support substrate and subpixels having at least three output wavelength distributions separated and arranged; subpixels having the first output wavelength distribution Includes a first color conversion layer containing at least one rhodamine dye and a silicone polymer or a resin-modified silicone polymer; and a second color conversion layer containing at least one coumarin dye; A sub-pixel having a distribution includes the second color conversion layer. FIG. 2 shows an example of the multicolor conversion filter 100 having subpixels having three types of output wavelength distributions. In the configuration of FIG. 2, a sub-pixel 110 having a first output wavelength distribution including a red color filter 2, a first color conversion layer 3, and a second color conversion layer 5 on a transparent support substrate 1; green color A sub-pixel 120 having a second output wavelength distribution including the filter 4 and the second color conversion layer 5; and a sub-pixel having a third output wavelength distribution including the blue color filter 6 are formed. A set of pixels is formed. Furthermore, in the configuration of FIG. 2, a protective layer 7, which may be optionally provided, is provided so as to cover each subpixel. The transparent support substrate 1, the first color conversion layer 3, and the second color conversion layer 5 in the present embodiment are the same as those described in the first embodiment.

  The sub-pixel 110 having the first output wavelength distribution in the present embodiment is a sub-pixel that emits red light including the first color conversion layer 3 and the second color conversion layer, and optionally including the red color filter 2. is there. In addition, the subpixel 120 having the second output wavelength distribution in the present embodiment is a subpixel that emits green light including the second color conversion layer 5 and optionally including the green color filter 4. The red color filter 2 and the green color filter 4 are layers for improving the color purity of red light or green light converted in the first color conversion layer 3 or the second color conversion layer 5.

  Furthermore, the sub-pixel 130 having the third output wavelength distribution in the present embodiment is a sub-pixel that emits blue light including the blue color filter 6. Depending on the light source to be used, the sub-pixel 130 may be used in combination with a color conversion layer containing a color conversion dye that converts near-ultraviolet to violet light into blue light. Alternatively, a clear layer may be laminated on the blue color filter 6 for the purpose of eliminating or reducing the level difference from the layer forming the other subpixels (110, 120). The clear layer is an optically transparent layer, and can be formed using a matrix that can be used for the first color conversion layer 3 or the second color conversion layer 5 described above.

  Each color filter (2, 4, 6) does not have a function of wavelength distribution conversion, but has a function of transmitting light of each color region and blocking light of other regions. Each color filter (2, 4, 6) is generally a pigment dispersed in a polymer binder. In the present invention, a display filter such as a liquid crystal display can be applied. .

  As the name suggests, the protective layer 7 is optionally disposed for the purpose of protecting the color conversion layer and the color filter and for the purpose of smoothing the film surface. The protective layer 7 must be formed by selecting a process that is formed of a material having high light transmittance and that does not deteriorate the color conversion filter. Further, when a transparent conductive film or the like used as an inorganic gas barrier film or an electrode is formed on the upper surface of the protective layer 7, the protective layer 7 is further required to have sputtering resistance.

  As described above, since the protective layer 7 also has the purpose of smoothing, it is generally formed by a coating method. At that time, applicable materials include a straight silicone polymer, a resin-modified silicone polymer, a non-photosensitive thermosetting resin that can be used as a matrix of the first color conversion layer 3 or the second color conversion layer 5, A thermoplastic resin or a photocurable resin can be used.

When the multicolor conversion filter of the present invention is combined with an organic EL element, a gas barrier layer 8 (see FIG. 3) is laminated on the upper surface of the protective layer 7 for the purpose of protecting the organic EL element from moisture generated from the color conversion filter. Also good. The gas barrier layer 8 is required to be a transparent and dense film without pinholes. For example, inorganic oxide or inorganic nitride such as SiO _x , SiN _x , SiN _x O _y , AlO _x , TiO _x , TaO _x , ZnO _x , etc. Can be used. There is no restriction | limiting in particular as a formation method of the gas barrier layer 8, It can form by usual methods, such as a sputtering method, CVD method, a vacuum evaporation method, a dip method.

  An organic EL display according to a fourth embodiment of the present invention includes the multicolor conversion filter according to the third embodiment and an organic EL element including a transparent electrode, an organic EL layer, and a reflective electrode. FIG. 3 shows an example of an organic EL display in which an organic EL element 200 in which the transparent electrode 9, the organic EL layer 10, and the reflective electrode 11 are laminated in this order on the multicolor conversion filter 100 is shown.

The organic EL layer 10 includes at least an organic light emitting layer and has a structure in which a hole injection layer, a hole transport layer, an electron transport layer and / or an electron injection layer are interposed as required. Alternatively, a hole injection / transport layer having both hole injection and transport functions and an electron injection / transport layer having both electron injection and transport functions may be used. Specifically, an organic EL element having the following layer structure is employed.
(1) Anode / organic light emitting layer / cathode (2) Anode / hole injection layer / organic light emitting layer / cathode (3) Anode / organic light emitting layer / electron injection layer / cathode (4) Anode / hole injection layer / organic Light emitting layer / electron injection layer / cathode (5) Anode / hole transport layer / organic light emitting layer / electron injection layer / cathode (6) Anode / hole injection layer / hole transport layer / organic light emitting layer / electron injection layer / Cathode (7) Anode / hole injection layer / hole transport layer / organic light emitting layer / electron transport layer / electron injection layer / cathode

  In the above layer configuration, the anode and the cathode are either the transparent electrode 9 or the reflective electrode 11, respectively. In this technique, it is known that it is easy to make the anode transparent. In the present invention, it is desirable to use the transparent electrode 9 as an anode and the reflective electrode 11 as a cathode. The transparent electrode 9 is desirably transparent in the wavelength range of light emitted from the organic EL layer 10, and emits light through the transparent electrode 9 to make the light enter the multicolor conversion filter 100.

  Known materials are used as the material for each of the above layers. For example, in order to obtain blue to blue-green light emission as an organic light emitting layer, for example, fluorescent brighteners such as benzothiazole, benzimidazole, and benzoxazole, metal chelated oxonium compounds, styrylbenzene compounds, aromatics Dimethylidin compounds and the like are preferably used.

  The transparent electrode 9 preferably has a transmittance of 50% or more, more preferably 85% or more with respect to light having a wavelength of 400 to 800 nm. The transparent electrode 9 is made of ITO (In—Sn oxide), NESA film, Sn oxide, In oxide, IZO (In—Zn oxide), Zn oxide, Zn—Al oxide, Zn—Ga oxide, Alternatively, a conductive transparent metal oxide in which a dopant such as F or Sb is added to these oxides can be used. The transparent electrode 9 is formed using a vapor deposition method, a sputtering method (including a reactive sputtering method) or a chemical vapor deposition (CVD) method, and preferably formed using a sputtering method (including a reactive sputtering method). The When the transparent electrode 9 is used as a cathode, it is desirable to provide a buffer layer at the interface with the organic EL layer 10 to improve electron injection efficiency. As the material of the buffer layer, alkali metals such as Li, Na, K, or Cs, alkaline earth metals such as Ba and Sr, alloys containing them, rare earth metals, or fluorides of these metals can be used. However, it is not limited to them. The film thickness of the buffer layer can be appropriately selected in consideration of the driving voltage, transparency, and the like, but in a normal case, it is preferably 10 nm or less.

  The reflective electrode 11 is preferably formed using a highly reflective metal, amorphous alloy, or microcrystalline alloy. High reflectivity metals include Al, Ag, Mo, W, Ni, Cr, and the like. High reflectivity amorphous alloys include NiP, NiB, CrP, CrB, and the like. High reflectivity microcrystalline alloys include NiAl and the like. The reflective electrode 11 may be used as a cathode or an anode. When the reflective electrode 11 is used as a cathode, the aforementioned buffer layer may be provided at the interface between the reflective electrode 11 and the organic EL layer 10 to improve the efficiency of electron injection into the organic EL layer 10. Alternatively, when the reflective electrode 11 is used as a cathode, an alkali metal such as lithium, sodium, or potassium, which is a material having a low work function, calcium, magnesium, or the like, which is a material having a low work function compared to the above-described high reflectivity metal, amorphous alloy, or microcrystalline alloy Further, an alkaline earth metal such as strontium can be added and alloyed to improve electron injection efficiency. When the reflective electrode 11 is used as an anode, the conductive transparent metal oxide layer described above is provided at the interface between the reflective electrode 11 and the organic EL layer 10 to improve the efficiency of hole injection into the organic EL layer 10. May be.

  The reflective electrode 11 can be formed using any means known in the art such as vapor deposition (resistance heating or electron beam heating), sputtering, ion plating, laser ablation, etc., depending on the material used. . As will be described later, when the reflective electrode 11 composed of a plurality of partial electrodes is required, the reflective electrode 11 composed of a plurality of partial electrodes may be formed using a mask giving a desired shape, or vice versa. The reflective electrode 11 including a plurality of partial electrodes may be formed using a separation partition wall having a tapered cross-sectional shape.

  In FIG. 3, the transparent electrode 9 and the reflective electrode 11 are each formed from a plurality of parallel stripe-shaped portions, and the stripe forming the transparent electrode 9 and the stripe forming the reflective electrode 11 intersect each other (preferably orthogonal) ). Therefore, the organic EL element 200 can perform matrix driving, that is, when a voltage is applied to a specific stripe of the transparent electrode 9 and a specific stripe of the reflective electrode 11, the organic EL element 200 is organic at a portion where the stripes intersect. The EL layer 10 emits light. Alternatively, a plurality of partial electrodes in which one electrode (for example, transparent electrode 9) is a uniform planar electrode having no stripe pattern and the other electrode (for example, reflective electrode 11) corresponds to each subpixel. It may be patterned. In that case, a plurality of switching elements corresponding to each subpixel are provided and connected to the partial electrodes corresponding to each subpixel on a one-to-one basis, so-called active matrix driving can be performed.

[Example 1]
Using a CR7001, CG7001, and CB7001 manufactured by FUJIFILM Electronics Materials Co., Ltd. on a Corning 1737 glass as the substrate 1, a width of 0.10 mm and a pitch of 0.33 mm so as not to overlap each other by photolithography. R, G, B stripe patterns were formed. The film thickness of each color filter (2, 4, 6) was 1.0 μm. Furthermore, a transparent stripe pattern having a film thickness of 10 μm, a width of 0.10 mm, and a pitch of 0.33 mm was formed by photolithography using only Nippon Steel Chemical's V259PAP5 on the upper surface of CB7001, which is the blue color filter 6. . In this case, when the color conversion layer is formed on the red and green sub-pixels (110, 120), it is formed so as not to cause a film thickness difference for each color sub-pixel.

  Rhodamine 6G (0.5 parts by weight) and basic violet 11 (0.5 parts by weight) as fluorescent dyes were added to 100 parts by weight of silicone polymer KP854 manufactured by Shin-Etsu Chemical Co., Ltd. to obtain a coating solution. Using this coating solution, a pattern having a width of 0.1 mm, a pitch of 0.33 mm, and a film thickness of 5 μm was formed on the red color filter 2 by screen printing to obtain a first color conversion layer 3.

  Next, coumarin 6 (0.9 parts by weight) as a fluorescent dye was dissolved in 120 parts by weight of a solvent, propylene glycol monoethyl acetate (PGMEA). To this solution, 100 parts by weight of V259PAP5 manufactured by Nippon Steel Chemical Co., Ltd. was added and dissolved to obtain a coating solution. Using this coating solution, a pattern having a width of 0.1 mm, a pitch of 0.33 mm, and a film thickness of 5 μm is formed on the upper surface of the green color filter 4 and the first color conversion layer 3 by a photolithographic method. A conversion layer 5 was obtained. And it heated to 180 degreeC over 30 minutes, and V259PAP5 in the 2nd color conversion layer 5 was hardened completely.

  Through the above steps, the sub-pixel 110 (red) having the first output wavelength distribution composed of a laminate of the red color filter 2, the first color conversion layer 3, and the second color conversion layer 5; the green color filter 4 and the first color filter A subpixel 120 (green) having a second output wavelength distribution made of a laminate of the two-color conversion layer 5; and a subpixel 130 having a third output wavelength distribution made of a laminate of the blue color filter 6 and the clear layer ( Blue) was formed.

  A protective layer 7 was formed on the upper surface of the subpixel formed as described above using V259PAP5 manufactured by Nippon Steel Chemical. When the thickness of the protective layer 7 is 2 μm from the surface of the second color conversion layer 5 forming the red subpixel, the unevenness of the surface of the protective layer 7 is within 1 μm, and the upper surface of the protective layer 7 is flat. It was.

A gas barrier layer made of a 0.5 μm SiOx film was obtained by sputtering. The sputtering apparatus RF- brake Na magnetron target was used SiO _2. Ar was used as the sputtering gas during film formation. The substrate temperature at the time of formation was 80 ° C.

  On the multicolor conversion filter 100 manufactured as described above, transparent electrode 9 (anode) / organic EL layer 10 (four layers of hole injection layer / hole transport layer / organic light emitting layer / electron injection layer) / The reflective electrode 11 (cathode) was sequentially formed to form an organic EL element 200 as shown in FIG. 3 to obtain an organic EL display.

  First, the entire surface of the transparent electrode 9 (ITO) was formed by sputtering on the upper surface of the gas barrier layer forming the outermost layer of the multicolor conversion filter 100. After applying a resist agent “OFRP-800” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) on ITO, patterning is performed by a photolithography method, and the width of each subpixel (red, green, and blue) is 0. A transparent electrode 9 (anode) having a stripe pattern of 0.094 mm, a pitch of 0.10 mm, and a film thickness of 100 nm was obtained.

Next, the substrate on which the anode was formed was mounted in a resistance heating vapor deposition apparatus, and a hole injection layer, a hole transport layer, an organic light emitting layer, and an electron injection layer were sequentially formed without breaking the vacuum. During film formation, the internal pressure of the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa. As the hole injection layer, copper phthalocyanine (CuPc) was laminated to a thickness of 100 nm. As the hole transport layer, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (α-NPD) was laminated to 20 nm. The light emitting layer was formed by laminating 30 nm of 4,4′-bis (2,2′-diphenylvinyl) biphenyl (DPVBi). The electron injection layer was formed by laminating aluminum chelate (Alq ₃ ) at 20 nm.

  Thereafter, using a mask that can obtain a stripe pattern having a width of 0.30 mm and a pitch of 0.33 mm perpendicular to the transparent electrode 9 (ITO) line without breaking the vacuum, a 200 nm thick Mg / Ag ( A 10: 1 weight ratio) layer was deposited to form the reflective electrode 11 (cathode).

  The organic EL display thus obtained was sealed using a sealing glass (not shown) and a UV curable adhesive in a dry nitrogen atmosphere in the group box (both oxygen and moisture concentrations were 10 ppm or less).

[Example 2]
An organic EL display was formed by the same procedure as in Example 1 except that the formation of the second color conversion layer 5 was changed as follows.

  Coumarin 6 (0.9 parts by weight) was dissolved in 120 parts by weight of propylene glycol monoethyl acetate (PGMEA) as a solvent. 100 parts by weight of a thermosetting epoxy resin (NLD-SL-1101: manufactured by Sanyu Rec Co., Ltd.) was added to the solution and dissolved to obtain a coating solution. A second color conversion layer having a pattern with a width of 0.1 mm, a pitch of 0.33 mm, and a film thickness of 5 μm is printed by printing the coating liquid on the upper surfaces of the green color filter 4 and the first color conversion layer 3 using a printing method. 5 was obtained.

[Example 3]
An organic EL display was formed by the same procedure as in Example 1 except that the formation of the first color conversion layer 3 and the second color conversion layer 5 was changed as follows.

  Rhodamine 6G (0.5 parts by weight) and basic violet 11 (0.5 parts by weight) as fluorescent dyes were added to 100 parts by weight of silicone polymer KP854 manufactured by Shin-Etsu Chemical Co., Ltd. to obtain a first coating solution. This first coating solution was applied by spin coating to form a first layer on the entire surface of the substrate.

  Coumarin 6 (0.9 parts by weight) was dissolved in 120 parts by weight of propylene glycol monoethyl acetate (PGMEA) as a solvent. 100 parts by weight of V259PAP5 manufactured by Nippon Steel Chemical Co., Ltd. was added to the solution and dissolved to obtain a second coating solution. A second color having a pattern with a width of 0.1 mm, a pitch of 0.33 mm, and a film thickness of 15 μm at the position corresponding to the red color filter 2 on the surface of the first layer by the photolithography method using the second coating liquid. A conversion layer 5 was formed. And it heated to 180 degreeC over 30 minutes, and V259PAP5 in the 2nd color conversion layer 5 was hardened completely.

Further, using the second color conversion layer 5 formed as described above as a mask, the first layer is etched by RIE plasma etching using SF ₆ gas at a pressure of 10 Pa, a substrate temperature of 50 ° C., and an RF input power of 3 kW. The first layer was divided into patterns having a width of 0.1 mm and a pitch of 0.33 mm. As a result, a red color conversion layer composed of a laminate of a first color conversion layer 3 having a thickness of 5 μm and a second color conversion layer 5 having a thickness of 5 μm is formed on the red color filter 2, and the first output wavelength A sub-pixel 110 (red) having a distribution was obtained.

  Next, the second color conversion layer 5 having a pattern with a width of 0.1 mm, a pitch of 0.33 mm, and a film thickness of 10 μm is formed on the green color filter 4 by the photolithography method using the second coating liquid. As a result, a sub-pixel 120 (green) having a second output wavelength distribution was obtained. And it heated to 180 degreeC over 30 minutes, and V259PAP5 in the 2nd color conversion layer 5 was hardened completely.

[Example 4]
An organic EL display was formed by the same procedure as in Example 1 except that the formation of the first color conversion layer 3 and the second color conversion layer 5 was changed as follows.

  Rhodamine 6G (0.5 parts by weight) and basic violet 11 (0.5 parts by weight) as fluorescent dyes were added to 100 parts by weight of silicone polymer KP854 manufactured by Shin-Etsu Chemical Co., Ltd. to obtain a first coating solution. This first coating solution was applied by spin coating to form a first layer on the entire surface of the substrate.

  Coumarin 6 (0.9 parts by weight) and 100 parts by weight of polystyrene resin are mixed, and the viscosity is adjusted by adding propylene glycol monoethyl acetate (PGMEA) as a solvent to obtain a printing composition having a viscosity of 5 Pa · s. Obtained. A printing composition is printed using a screen printing method, and a second pattern having a width of 0.1 mm, a pitch of 0.33 mm, and a film thickness of 15 μm is formed at a position corresponding to the red color filter 2 on the surface of the first layer. A color conversion layer 5 was formed.

  Further, using the second color conversion layer 5 having a predetermined pattern shape as a mask, the first layer is etched by the same RIE plasma etching method as described in Example 3, and the first layer has a width of 0.1 mm. It divided | segmented into the pattern of pitch 0.33mm. As a result, a red color conversion layer composed of a laminate of a first color conversion layer 3 having a thickness of 5 μm and a second color conversion layer 5 having a thickness of 5 μm is formed on the red color filter 2, and the first output wavelength A sub-pixel 110 (red) having a distribution was obtained.

  Next, coumarin 6 (0.9 parts by weight) was dissolved in 120 parts by weight of propylene glycol monoethyl acetate (PGMEA) as a solvent. 100 parts by weight of V259PAP5 manufactured by Nippon Steel Chemical Co., Ltd. was added to the solution and dissolved to obtain a second coating solution. A second color conversion layer 5 having a pattern with a width of 0.1 mm, a pitch of 0.33 mm, and a film thickness of 10 μm is formed on the green color filter 4 by photolithography using a second coating solution, A sub-pixel 120 (green) having an output wavelength distribution of 2 was obtained. And it heated to 180 degreeC over 30 minutes, and V259PAP5 in the 2nd color conversion layer 5 was hardened completely.

[Comparative Example 1]
An organic EL display was formed by the same procedure as in Example 3 except that the sub-pixel 110 (red) having the first output wavelength distribution was formed as follows.

  Rhodamine 6G (0.3 parts by weight), basic violet 11 (0.3 parts by weight) and coumarin 6 (0.5 parts by weight) as fluorescent dyes are added to 100 parts by weight of Nippon Steel Chemical V259PAP5 and dissolved. A coating solution was obtained. A red conversion layer having a pattern with a width of 0.1 mm, a pitch of 0.33 mm, and a film thickness of 5 μm is formed on the red color filter 2 by a photolithographic method using this coating solution, and has a first output wavelength distribution. A subpixel 110 (red) was obtained.

[Evaluation]
The organic EL displays formed in the example and the comparative example are driven under the same conditions, and the initial luminance and chromaticity of the sub-pixel 110 (red) having the first output wavelength distribution, and the luminance retention after 1000 hours of driving. Compared. The results are shown in Table 1.

  From the results of Table 1, in addition to the red subpixels of the organic EL displays of Examples 1 to 4 according to the present invention emitting red light having a chromaticity substantially equivalent to the red subpixel of the display of Comparative Example 1 It can be seen that the initial luminance is 20% higher than that of Comparative Example 1, and the color conversion efficiency of the red color conversion layer, which is a laminate of the first color conversion layer 3 and the second color conversion layer 5, is improved. Furthermore, in the comparison of the luminance retention after driving for 1000 hours, a luminance decrease of 25% was observed in Comparative Example 1, whereas the luminance decrease in Examples 1 to 4 was less than 10% in any case. It can be seen that the red color conversion layer of the present invention has excellent durability.

  From the above, by using a resin optimized according to the type of color conversion dye as a matrix, the amount of color conversion dye added can be increased to improve color conversion efficiency, and the color conversion dye and resin It is thought that this is a result of suppressing the reaction with and imparting high durability.

It is sectional drawing which shows the red color conversion filter of this invention. It is sectional drawing which shows the multicolor conversion filter (for 1 pixel) of this invention. It is sectional drawing which shows the organic electroluminescent display (for 1 pixel) of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent support substrate 2 Red color filter 3 1st color conversion layer 4 Green color filter 5 2nd color conversion layer 6 Blue color filter 7 Protective layer 8 Gas barrier layer 9 Transparent electrode 10 Organic EL layer 11 Reflective electrode 100 Multicolor conversion filter 110, 120, 130 (first, second, third) sub-pixel 200 having output wavelength distribution of organic EL element

Claims (10)

  A red conversion filter comprising a transparent support substrate and a color conversion layer comprising at least two layers including a first color conversion layer and a second color conversion layer, wherein the first color conversion layer comprises at least one rhodamine A red conversion filter comprising: a system dye and a silicone polymer or a resin-modified silicone polymer, wherein the second color conversion layer includes at least one coumarin dye.   The red color conversion filter according to claim 1, wherein the second color conversion layer further includes a non-photosensitive thermosetting resin or a thermoplastic resin.   The red color conversion filter according to claim 1, wherein the second color conversion layer further includes a photocurable resin. Forming a first layer comprising at least one rhodamine dye and a silicone polymer or a resin-modified silicone polymer on a transparent support substrate;
Forming a second color conversion layer having a predetermined pattern shape on the upper surface of the first color conversion layer, including at least one coumarin dye;
And patterning the first layer using the second color conversion layer as a mask to form a first color conversion layer.   5. The red color conversion filter according to claim 4, wherein the step of forming the second color conversion layer includes a step of printing a composition containing at least one coumarin-based pigment using a printing method. Patterning method.   Forming the second color conversion layer by applying a composition containing at least one coumarin dye and a photocurable resin to the entire upper surface of the first layer to form a second layer; 5. The method for patterning a red color conversion filter according to claim 4, further comprising: patterning the second layer to form a second color conversion layer having a predetermined pattern shape. A multicolor conversion filter in which a transparent support substrate and subpixels having at least three types of output wavelength distribution are separated and arranged,
A second color in which the sub-pixel having the first output wavelength distribution includes a first color conversion layer including at least one rhodamine dye and a silicone polymer or a resin-modified silicone polymer, and at least one coumarin dye. Including a conversion layer,
A multi-color conversion filter, wherein a sub-pixel having a second output wavelength distribution includes the second color conversion layer.   The multicolor conversion filter according to claim 7, wherein the second color conversion layer further includes a non-photosensitive thermosetting resin or a thermoplastic resin.   The multicolor conversion filter according to claim 7, wherein the second color conversion layer further includes a photocurable resin. An organic EL display comprising the multicolor conversion filter according to claim 7 and an organic EL element having a transparent electrode, an organic EL layer, and a reflective electrode.

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