JP2013097145A - Contrast improving filter for pdp, method for manufacturing filter, and plasma display device using filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contrast improving filter for PDP (Plasma Display Panel), even when a neon light absorber layer is provided close to a contrast improving layer without a barrier layer interposed therebetween, preventing deterioration of a neon light absorbing function by residues of photoinitiator in the contrast improving layer, and to provide a manufacturing method therefor and a plasma display device using the same.SOLUTION: A contrast improving filter 10 for PDP includes: a light transmission part 2a formed on a transparent base material 1; and a neon light absorber layer 3 formed with its coming into contact with a contrast improving layer 2 that has a light absorbing part 2b. At least the light absorbing part of the contrast improving layer is formed from a hardened material formed by photopolymerizing a dark-color resin composition containing a light absorbing color material, a photopolymerizable compound, and a photoinitiator having 400 or more molecular weight.

Description

  The present invention provides a contrast enhancement filter for PDP which is arranged on the viewer side of a plasma display panel (also referred to as PDP) to prevent the contrast of an image displayed on the display panel from being reduced by external light, and the manufacture of this filter. The present invention relates to a method and a plasma display device using the filter. In particular, the present invention relates to a contrast enhancement filter for PDP that also has a function of absorbing neon light from a PDP and suppresses deterioration of the neon light absorption function over time, a manufacturing method thereof, and a plasma display device using the same.

  On the observer side such as a plasma display panel (PDP), a contrast enhancement filter that prevents a decrease in image contrast due to external light, an electromagnetic wave shielding filter that shields electromagnetic waves emitted from the display panel, and a near infrared absorption filter that shields near infrared rays Various filters such as a neon light absorption filter that blocks neon light, a color correction filter that adjusts a display image to a desired color tone, or an antireflection filter that prevents external light reflection are provided as required.

  The contrast enhancement filter for PDP usually has at least a transparent substrate made of a resin film and a contrast enhancement layer. In the contrast improving layer, usually, a number of strip-shaped light absorbing portions are arranged in a stripe shape, and a space between the light absorbing portions is used as a light transmitting portion. External light is absorbed by the light absorption part, and image light is transmitted by the light transmission part. Such a contrast improving layer is formed by using a mold and a photocurable resin as a transparent resin layer having a large number of concave portions corresponding to the shape of the light absorbing portion on the surface of the transparent substrate, for example. Then, a light transmission part is formed by photocuring by light irradiation such as ultraviolet rays, and then dark ink containing carbon black in a binder resin is filled only in the inside of the concave part and solidified to form a large number of light absorbing parts. By forming. The neon light absorption filter is realized by a neon light absorption layer in which a neon light absorption dye is contained in a binder resin.

  In particular, in a filter for a display panel, it is desired to realize a plurality of filter functions with a single filter from the viewpoint of reducing the thickness of the filter and reducing the cost. For this reason, in the contrast enhancement filter for PDP, in addition to the contrast enhancement function, a filter that combines an electromagnetic wave shielding function, a near infrared absorption function, a neon light absorption function, a color correction function, an antireflection function, etc. according to the required performance (See, for example, Patent Document 1).

JP 2008-146073 A

  However, if the contrast improving layer and the neon light absorbing layer that realizes the neon light absorbing function are provided adjacent to each other, the neon light absorbing function may deteriorate over time. This is because the residue of the photopolymerization initiator remaining in the cured product of the photocurable resin constituting the contrast improving layer moves into the neon light absorbing layer over time and degrades the neon light absorbing dye. it is conceivable that.

  In order to prevent this, a transparent resin film or the like is interposed as a barrier layer between the contrast improving layer and the neon light absorbing layer. However, since the transparent resin film has a role as a support for the contrast improving layer and a role as a protective layer, in terms of layer structure, the contrast improving layer is always provided on one side of the transparent resin film and the other side. A neon light absorption layer cannot be disposed. For example, in order from the viewer side, a neon light absorbing layer that also serves as a transparent substrate made of a transparent resin film that plays a role as a support and protective layer, a contrast improving layer, and an adhesive layer for attaching to a display panel. It is a layer structure.

  Further, the barrier layer function can be realized by a barrier layer formed by coating without using a transparent resin film. So, we examined a configuration in which a barrier layer made of a resin coating was provided between the contrast enhancement layer and a light absorption layer (wavelength filter layer) that absorbs neon light and near infrared rays. There is a problem in that an additional process for applying the resin coating is required, increasing the number of processes, and leading to a cost increase factor.

  That is, the problem of the present invention is that the neon light absorbing function of the neon light absorbing layer can be achieved even when the neon light absorbing layer is provided adjacent to the contrast improving layer without providing a barrier layer that leads to high costs together with the contrast improving layer. Is to provide a contrast enhancement filter for PDP which is prevented from being deteriorated by a photopolymerization initiator at the time of forming a contrast enhancement layer. Moreover, it is providing the manufacturing method of this filter, and the image display apparatus using this filter.

  As a result of intensive studies to solve the above problems, the present inventors have determined that at least the light absorbing portion of the contrast improving layer is a dark color containing a light absorbing colorant, a photopolymerizable compound, and a specific photopolymerization initiator. It has been found that by forming the resin composition by photopolymerization, elution of the photopolymerization initiator and / or its residue can be prevented and the above-mentioned problems can be solved. The present invention has been completed based on such findings.

That is, according to one aspect of the present invention,
A transparent substrate, a light transmitting portion formed on one surface of the transparent substrate and having a plurality of grooves arranged in the surface direction, and a light absorbing portion formed in the groove of the light transmitting portion A contrast enhancement filter for PDP comprising a contrast enhancement layer and a neon light absorption layer formed adjacent to the contrast enhancement layer and containing a neon light absorption dye,
Curing in which at least the light absorption part of the contrast enhancement layer is formed by photopolymerizing a dark resin composition containing a light absorbing colorant, a photopolymerizable compound, and a photopolymerization initiator having a molecular weight of 400 or more. A contrast enhancement filter for PDP made of an object is provided.

  In the embodiment of the present invention, the photopolymerization initiator preferably contains three or more phenyl groups or derivatives thereof in the chemical structure.

  In an embodiment of the present invention, the photopolymerization initiator includes 1- [4- (4-benzoylphenylsulfanyl) phenyl] -2-methyl-2- (4-methylphenylsulfonyl) propan-1-one, and oligo It is preferably selected from the group consisting of dimers and trimers of [2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propane].

  In the embodiment of the present invention, the dark resin composition preferably further contains an aminobenzoate polymerization accelerator.

  In the aspect of the present invention, the aminobenzoate polymerization accelerator is preferably at least one selected from the group consisting of ethyl-4- (dimethylamino) benzoate and ethylhexyl-4-dimethylaminobenzoate.

  In the embodiment of the present invention, the dark resin composition preferably further contains an ultraviolet absorber.

  In the embodiment of the present invention, the dark resin composition preferably further contains an antioxidant.

  In an aspect of the present invention, a functional layer is further provided at any one or more positions on the other surface of the transparent substrate, between the transparent substrate and the contrast improving layer, or on the surface of the neon light absorption layer. The functional layer comprises a near infrared absorption layer, an ultraviolet absorption layer, a color correction layer, an antireflection layer, an electromagnetic wave shielding layer, a surface protective layer, a hard coat layer, an antistatic layer, a contamination prevention layer, and an impact resistant layer. It is preferably at least one selected from the group consisting of a barrier layer and an adhesive layer.

According to another aspect of the invention,
A transparent substrate, a light transmitting portion formed on one surface of the transparent substrate and having a plurality of grooves arranged in the surface direction, and a light absorbing portion formed in the groove of the light transmitting portion A method for producing a contrast enhancing filter for PDP, comprising: a contrast improving layer; and a neon light absorbing layer formed adjacent to the contrast improving layer and containing a neon light absorbing dye.
(A) A resin composition containing a photopolymerizable compound and a photopolymerization initiator is cured by photopolymerization by light irradiation, and a light transmitting portion having a large number of concave portions having a concave and convex shape opposite to the light absorbing portion on the surface. Formed on a transparent substrate,
(B) Next, the concave portion is filled with a dark resin composition containing a light-absorbing colorant, a photopolymerizable compound, and a photopolymerization initiator having a molecular weight of 400 or more, and cured by photopolymerization by light irradiation. By forming a light absorption part, a contrast enhancement layer is formed,
(C) Next, a neon light absorbing layer containing a neon light absorbing dye is formed on the surface of the contrast improving layer.
A method of manufacturing a contrast enhancement filter for PDP is provided.

  In another aspect of the present invention, the photopolymerization initiator preferably contains three or more phenyl groups or derivatives thereof in the chemical structure.

  In another embodiment of the present invention, the photopolymerization initiator is 1- [4- (4-benzoylphenylsulfanyl) phenyl] -2-methyl-2- (4-methylphenylsulfonyl) propane-1- Preferably, it is selected from the group consisting of dimers and trimers of ON and oligo [2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propane].

  In another aspect of the present invention, the dark resin composition preferably further contains an aminobenzoate polymerization accelerator.

  In another aspect of the present invention, the aminobenzoate polymerization accelerator is at least one selected from the group consisting of ethyl-4- (dimethylamino) benzoate and ethylhexyl-4-dimethylaminobenzoate. Is preferred.

  Moreover, in the other aspect of this invention, it is preferable that the said dark color resin composition further contains a ultraviolet absorber.

  Moreover, in the other aspect of this invention, it is preferable that the said dark color resin composition further contains antioxidant.

According to yet another aspect of the present invention,
There is provided a plasma display device comprising the PDP contrast enhancement filter or the PDP contrast enhancement filter obtained by the production method on the observer side of the plasma display panel.

(1) According to the contrast enhancement filter for PDP according to the present invention, even if it is a neon light absorption layer disposed adjacent to the contrast enhancement layer, the neon light absorption layer by the photopolymerization initiator used at the time of forming the contrast enhancement layer Prevents deterioration of neon light-absorbing dye. For this reason, it can prevent that a neon light absorption function falls over time. In addition, it is not necessary to separately provide a barrier layer between the contrast enhancement layer and the neon light absorption layer, and there is no increase in the number of processes and production cost associated with the addition of the barrier layer, and a contrast enhancement filter for PDP that suppresses product cost I can do it. Further, by adding a functional layer, various functions such as a near infrared absorption function, a color correction function, an antireflection function, an electromagnetic wave shielding function, a surface protection function, an antistatic function, and an antifouling function can be further provided. .
(2) According to the method for producing a contrast enhancement filter for PDP according to the present invention, the neon light absorption performance is not deteriorated with time even if the neon light absorption layer is formed adjacent to the contrast enhancement layer. It is possible to easily manufacture a PDP contrast improving filter that can achieve the effects described in 1).
(3) According to the plasma display device of the present invention, it is possible to prevent deterioration in display image quality due to deterioration of neon light absorption performance over time.

It is the cross-sectional schematic which showed one Embodiment of the contrast improvement filter for PDP by this invention. It is the cross-sectional schematic which showed another embodiment (with a functional layer) of the contrast improvement filter for PDP by this invention. It is the cross-sectional schematic which showed the manufacturing method of the contrast improvement filter for PDP by this invention in one Embodiment. 1 is a schematic cross-sectional view illustrating an embodiment of a plasma display device according to the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are conceptual diagrams, and the scale relationships, aspect ratios, and the like of components may be exaggerated. In the present specification, the “surface direction” is a direction parallel to the sheet surface of the contrast enhancement filter for PDP, in other words, a direction parallel to the front and back surfaces of the contrast enhancement layer.

A. Contrast improvement filter for PDP:
First, referring to the cross-sectional view of FIG. 1, the contrast enhancement filter for PDP of the present invention will be described in an embodiment. The contrast enhancement filter 10 for PDP of the present invention in the form illustrated in FIG. 1 is formed on a transparent substrate 1 and one surface of the transparent substrate 1 (in the case of FIG. A contrast improving layer 2 having a light transmitting portion 2a in which the grooves are arranged in parallel, and a light absorbing portion 2b formed in the groove of the light transmitting portion 2a, and adjacent to the contrast improving layer 2, And a neon light absorbing layer 3 containing a neon light absorbing dye.

  The light transmitting portion 2a is basically not particularly limited as to the material thereof, but is preferably made of a cured product formed by photopolymerizing a resin composition containing a photopolymerizable compound and a photopolymerization initiator. . In a preferred embodiment, it is preferable to use a photopolymerization initiator similar to the light absorption part described below.

  The light absorption part 2b consists of the hardened | cured material formed by photopolymerizing the dark color resin composition containing a light absorptive color material, a photopolymerizable compound, and the photoinitiator which has a molecular weight of 400 or more. In the form in which the light absorbing portion 2b is in contact with the neon light absorbing layer 3 as shown in FIG. 1, the photopolymerization initiator in the light absorbing portion 2b has a molecular weight of 400 or more from the viewpoint of suppressing a decrease in neon light absorbing performance. By using a photopolymerization initiator, elution of the photopolymerization initiator and / or its residue can be prevented, and deterioration of the neon light absorbing dye in the neon light absorbing layer 3 can be prevented. For this reason, neon light absorption performance does not fall.

  The light absorbing portions 2b are usually arranged in a regular interval with the shape of the plan view being a band shape and extending in parallel with each other. For example, in the contrast improving layer 2 illustrated in the cross-sectional view of FIG. 1, the light absorbing portion 2 b has a triangular cross-sectional shape, a straight line shape in plan view, and extends perpendicularly from the front to the back of the paper. Yes. Further, the light transmission part 2a exists between the light absorption parts 2a in the left-right direction of the drawing, and also exists above the triangular top of the light absorption part 2b in the drawing.

  If the example of the shape and dimension of the light transmission part 2a and the light absorption part 2b is shown here, the light absorption part 2b is a columnar body of the cross-sectional shape of an isosceles triangle with a base of 20 μm and a height of 120 μm. A large number of light absorbing portions 2b are arranged in a fixed cycle with a plurality of extending directions of the columnar bodies parallel to the surface direction and spaced apart from each other. Therefore, the planar view shape of the light absorbing portion 2b is that in which straight lines are arranged in one direction at intervals. The arrangement period of the light absorbing portion 2b is 80 μm (the interval is 60 μm), and the thickness of the light transmitting portion 2a is 200 μm. In addition, this invention is not limited to the shape and dimension which were illustrated here.

  Hereinafter, each layer will be described in detail.

(Transparent substrate)
As the transparent substrate 1, a transparent substrate made of glass, resin or the like can be used. The resin of the transparent substrate 1 is, for example, a polyester resin such as polyethylene terephthalate, a polyolefin resin such as a cycloolefin polymer, a cellulose resin such as triacetyl cellulose, an acrylic resin, or a polycarbonate resin. These resins are used in the form of films, sheets, and plates. Note that “film”, “sheet”, and “plate” are generally roughly distinguished by thickness, but in the present invention, they are merely different in name and there is no particular distinction in meaning. In addition, the thickness of the transparent base material 1 is 12-500 micrometers in the case of a resin sheet, for example.

  The transparent substrate 1 may contain various known additives as necessary, such as improvement of physical properties. For example, antistatic agents, ultraviolet absorbers, fillers and the like.

[Contrast improvement layer]
The contrast enhancement layer 2 is a layer formed on at least one surface of the transparent substrate 1, and has a light transmission part 2a in which a plurality of grooves are arranged in parallel in the surface direction, and the grooves of the light transmission part 2a. It consists of the light absorption part 2b formed. The light absorbing part 2b absorbs external light, and the light transmitting part 2a between the light absorbing parts 2b secures the image light transparency, thereby suppressing the influence of the external light and improving the contrast.

  The thickness of the contrast enhancement layer 2 is equal to the thickness of the light transmission part 2a, and the thickness of the light transmission part 2a is usually equal to or greater than the thickness of the light absorption part 2b. Although the thickness of the light transmission part 2a is based also on a specification, it is about 50-300 micrometers, for example, Preferably it is about 50-250 micrometers.

[Light absorption part]
The light absorption part 2b is an optical element that absorbs external light, and is obtained by photopolymerizing a dark resin composition containing a light-absorbing color material, a photopolymerizable compound, and a photopolymerization initiator having a molecular weight of 400 or more. It consists of the formed cured product. The light absorbing color material may be an organic material or an inorganic material. As the organic material, a dark resin composition such as a paint (or ink) in which a light-absorbing color material is contained in a binder resin (photopolymerizable compound) can be used.

  As the light-absorbing color material, a dark color material having high light-absorbability and a dark color, that is, a chromatic or achromatic color with low brightness can be used. A representative example of the dark color is black, and an achromatic black color is preferable because it does not affect the color of the image display and the external light absorption is large. In addition, examples of low-lightness chromatic colors include brown, amber, rosy, and dark green. As the dark color material, a known color material, for example, black pigment such as carbon black or black iron oxide, black dye such as aniline black, or the like may be used. The dark color material may be dark resin particles obtained by coloring acrylic resin particles or the like with these dark color materials in a dark color. Further, a dark color material may be an achromatic color such as black or a chromatic dark color by mixing a plurality of kinds of chromatic color materials such as blue, yellow, and red, and mixing the colors. The addition amount of the light absorbing colorant is preferably 5 to 100% by mass with respect to the total amount of the photopolymerizable compound.

  The photopolymerizable compound is not particularly limited as long as it is a compound that can be cured by photopolymerization by irradiation with light such as ultraviolet rays or visible light in the presence of a photopolymerization initiator, and a known compound can be appropriately employed. . As such a photopolymerizable compound, one type or two or more types selected from the group of prepolymers (including oligomers) and monomers that can be cured by light irradiation are used. The photopolymerizable compound is used as a photopolymerizable resin composition in which one or more selected from these prepolymers and monomers are mixed with a photopolymerization initiator.

  As the prepolymer and monomer, specifically, a compound having a radical polymerizable unsaturated group such as a (meth) acryloyl group or a (meth) acryloyloxy group in the molecule can be used. For example, the (meth) acryloyl group means an acryloyl group or a methacryloyl group. Moreover, the following (meth) acrylates are the meanings of an acrylate or a methacrylate similarly. In addition, the acrylate compound and the methacrylate compound are collectively referred to simply as an acrylate (compound) or an acrylate compound.

  Examples of prepolymers having radically polymerizable unsaturated groups include acrylate-based prepolymers such as polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, melamine (meth) acrylate, and triazine (meth) acrylate. Etc. can be used.

  As an example of a monomer having a radical polymerizable unsaturated group, in the case of an acrylate monomer, as a monofunctional monomer, methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, phenoxyethyl (meth) acrylate, Acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, carboxypolycaprolactone (meth) acrylate, etc. System monomers and (meth) acrylamide. In addition, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate as polyfunctional monomers , Bifunctional monomers such as tripropylene glycol di (meth) acrylate, pentaerythritol di (meth) acrylate monostearate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethylene oxide tri ( Trifunctional monomers such as (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaeryth Penta (meth) acrylate, polyfunctional monomers such as four or more functional such as dipentaerythritol hexa (meth) acrylate.

  The photopolymerization initiator used for the dark resin composition has a molecular weight of 400 or more and a melting point of preferably 80 ° C. or more, more preferably 100 ° C. or more. By using a polymerization initiator having such a molecular weight and melting point, elution of the photopolymerization initiator and / or its residue can be prevented, and deterioration of the neon light absorbing dye in the neon light absorbing layer can be prevented. According to a preferred embodiment, the photopolymerization initiator is such that the photopolymerization initiator contains three or more phenyl groups or derivatives thereof in the chemical structure. According to a more preferred embodiment, the photopolymerization initiator is 1- [4- (4-benzoylphenylsulfanyl) phenyl] -2-methyl-2- (4-methylphenylsulfonyl) propan-1-one, and oligo [ It is selected from the group consisting of dimers and trimers of 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propane].

  The addition amount of the photopolymerization initiator is preferably 1 to 5% by mass and more preferably 2 to 3% by mass with respect to the total amount of the light-absorbing colorant and the photopolymerizable compound. When the addition amount is 1% by mass or more, the photopolymerizable compound can be sufficiently photopolymerized and sufficiently cured. Moreover, if the addition amount is 5% by mass or less, the cost can be reduced and the deterioration of the neon light-absorbing dye is suppressed.

  The dark resin composition preferably further contains an aminobenzoate polymerization accelerator. As the aminobenzoate polymerization accelerator, it is preferable to use at least one selected from the group consisting of ethyl-4- (dimethylamino) benzoate and ethylhexyl-4-dimethylaminobenzoate. In particular, it is more preferable to use ethyl-4- (dimethylamino) benzoate. By using a combination of the specific photopolymerization initiator and the aminobenzoate polymerization accelerator, curing of the photopolymerizable compound can be promoted and deterioration due to unreacted monomers can be suppressed.

  The dark resin composition preferably further contains an ultraviolet absorber. By containing the ultraviolet absorber, the deterioration of the neon light absorbing dye in the neon light absorbing layer can be further prevented. A known compound can be used as the ultraviolet absorber. Examples of such UV absorbers include organic UV absorbers such as benzotriazole, benzophenone, salicylate, and benzoate, and inorganic UV absorbers.

  Examples of the benzotriazole ultraviolet absorber in the organic ultraviolet absorber include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-5′-butylphenyl) benzotriazole, 2 -(2'-hydroxy-5'-t-butylphenyl) benzotriazole, 2- (2'-hydroxy-5'-t-octylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5' -Di-t-butylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole, 2- (2'-hydroxy-3'-t-butyl- 5′-methylphenyl) -5-chlorobenzotriazole or 2- (2′-hydroxy-3 ′, 5′-di-t-butylphenyl) 5-chloro-benzotriazole.

  Examples of benzophenone ultraviolet absorbers include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, and 2,2′-dihydroxy. Examples include -4-methoxybenzophenone or 2,2′-dihydroxy-4,4′-dimethoxybenzophenone.

  Examples of salicylate ultraviolet absorbers include phenyl salicylate, pt-butylphenyl salicylate, and p-octylphenyl salicylate. Examples of benzoate ultraviolet absorbers include hexadecyl-2,5-t-butyl-4-hydroxybenzoate, or 2,4-di-t-butylphenyl-3 ′, 5′-di-t-butyl-4′-. Examples thereof include hydroxybenzoate.

  Examples of inorganic ultraviolet absorbers include fine powders such as titanium oxide, zinc oxide, cerium oxide, iron oxide, and barium sulfate.

  The absorption wavelength of the ultraviolet absorbent is preferably over the entire wavelength range of 10 to 380 nm in the ultraviolet band. By containing an ultraviolet absorber in the contrast enhancement layer 2, the ultraviolet absorption performance as the contrast enhancement filter 10 can be set to a transmittance of 0.2% or less in the wavelength range of 10 to 380 nm. It becomes.

  The addition amount of the ultraviolet absorber is preferably 0.3 to 3% by mass, more preferably 0.5 to 2% by mass with respect to the total amount of the light-absorbing colorant and the photopolymerizable compound. . If the addition amount of the ultraviolet absorber is 0.3% by mass or more, sufficient ultraviolet absorbing ability can be exhibited, and if it is 3% by mass or less, the curing is hardly affected. However, in the present invention, since the ultraviolet absorber is included in the contrast improving layer 2 which is thick and usually 50 μm or more, in order to increase the ultraviolet absorption performance depending on the thickness, it is included in the thin layer. Compared to, the volume ratio can be reduced. For this reason, it is easy to balance the inhibition of photopolymerization and the ultraviolet absorption performance.

  In order to photopolymerize a resin composition containing a photopolymerizable compound and the specific photopolymerization initiator, it is preferable to irradiate ultraviolet rays or visible light. However, when light in the ultraviolet region is used when photopolymerizing the light absorbing portion 2b, the ultraviolet light on the long wavelength side at the boundary wavelength 380 nm side with the visible light region is not completely absorbed by the ultraviolet absorber. In addition, it may be left to the extent that it can contribute to photopolymerization. In addition, this is not the case when the photopolymerization is performed with light in the visible light region of 380 nm or more.

  The dark resin composition preferably further contains an antioxidant. By including an antioxidant in the dark resin composition, the color change in the visible light region and the color change in the near infrared region can be further suppressed. That is, there is a possibility that acid is generated from the residue of the photopolymerization initiator or the residue of the photopolymerizable compound due to ultraviolet rays and temperature, and the dye in the dye-containing light absorption layer is oxidized by this acid, and the dye may be deteriorated. is there. On the other hand, when the antioxidant is contained in the dark resin composition, the oxidation of the dye contained in the dye-containing light absorption layer can be suppressed by the antioxidant, so that the deterioration of the dye can be further suppressed. The color change in the visible light region and the color change in the near infrared region can be further suppressed.

  Examples of the antioxidant include phenol-based, amine-based, sulfur-based, and phosphorus-based antioxidants. Examples of phenolic antioxidants include 2,6-di-t-butyl-p-cresol (BHT), 2,2′-methylenebis (4-methyl-6-t-butylphenol), triethylene glycol-bis [3 -(3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], Pentaerythrityl tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenylpropionate), 3 , 5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester and the like.

  Examples of amine-based antioxidants include octyl diphenylamine, Nn-butyl-p-aminophenol, N, N-diisopropyl-p-phenylenediamine, n-butylamine, triethylamine, diethylaminomethyl methacrylate and the like.

  Examples of the sulfur-based antioxidant include dilauryl-3,3'-thiodipropionate (DLTDP), distearyl 3,3'-thiodipropionate (DSTDP), and the like. Examples of phosphorus antioxidants include triphenyl phosphite (TTP) and triisodecyl phosphite (TDP).

  The addition amount of the antioxidant is preferably 0.3 to 3% by mass and more preferably 0.5 to 2% by mass with respect to the total amount of the light-absorbing color material and the photopolymerizable compound. If the added amount of the antioxidant is 0.3% by mass or more, a sufficient antioxidant effect can be exhibited, and if it is 3.0% by mass or less, the antioxidant is hardly bleed out.

[Light transmission part]
The light transmission part 2a is a transparent optical element formed as a cured product of the resin composition by photopolymerizing and curing a resin composition containing a photopolymerizable compound and a photopolymerization initiator. . As the photopolymerizable compound and the photopolymerization initiator, those similar to the light absorption part can be used, and the details thereof are as described above.

  According to a preferred embodiment, as a photopolymerization initiator, 1- [4- (4-benzoylphenylsulfanyl) phenyl] -2-methyl-2- (4-methylphenylsulfonyl) propan-1-one, and oligo [2 By using at least one selected from the group consisting of a dimer and a trimer of -hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propane], a photopolymerization initiator and In addition, deterioration of the neon light absorbing dye in the neon light absorbing layer due to the residue can be further prevented.

  It is preferable that the resin composition for forming a light transmission part further includes at least one selected from the group consisting of an aminobenzoate polymerization accelerator, an ultraviolet absorber, and an antioxidant. As the aminobenzoate polymerization accelerator, the ultraviolet absorber, and the antioxidant, those similar to those of the light absorbing portion can be used, and the details thereof are as described above.

[Method for forming contrast enhancement layer]
The contrast improving layer 2 can be formed by a manufacturing method using a 2P method described later. Details will be described in the column of the manufacturing method.

[Neon light absorption layer]
The neon light absorbing layer 3 is a layer that absorbs neon light emitted from the PDP by including a neon light absorbing dye. The neon light absorbing dye absorbs an emission spectrum band of neon atoms, that is, a wavelength region of 550 to 640 nm (neon light region) and absorbs as much as possible in a visible light region of 380 nm to 780 nm excluding the wavelength region. And a dye having a sufficient light transmittance is used. For this reason, the neon light-absorbing dye has a neon light-absorbing dye and a neon light-absorbing dye in the layer so that the light transmittance at 590 nm is 50% or less if the center wavelength of the neon light region is 590 nm. It is preferable to set the addition amount in the layer, the thickness of the layer, and the like.
Specific examples of such neon light absorbing dyes include neon light absorbing dyes such as cyanine dyes, oxonol dyes, methine dyes, subphthalocyanine dyes, and porphyrin dyes. These dyes can be used alone or in combination of two or more.

  The neon light-absorbing layer 3 can be formed by applying a composition containing the neon light-absorbing dye in a binder resin to the surface of the contrast improving layer 2 and solidifying it by drying, curing, or the like. Alternatively, a pressure-sensitive adhesive layer, an adhesive layer, or the like that is applied and formed on another surface may be transferred and formed on the surface of the contrast improving layer 2 by transfer.

  As the resin of the binder resin, it is preferable to use thermoplastic resins such as acrylic resin, polyester resin, urethane resin, and styrene resin, and thermosetting resins such as urethane resin, epoxy resin, and acrylic resin. Further, when the neon light absorbing layer 3 is also used as a pressure-sensitive adhesive layer that is also a kind of functional layer described later, a pressure-sensitive adhesive such as acrylic resin or polyester resin can be used as the binder resin. In addition, when there exists a possibility of the pigment deterioration by a photoinitiator, you should avoid the photocurable resin containing a photoinitiator.

  In the PDP contrast enhancement filter, a specific photopolymerization initiator is also used for the light transmitting portion 2a of the contrast enhancement layer 2 in contact with the neon light absorption layer 3, so that the neon light absorption layer due to the residue of the photopolymerization initiator is used. The deterioration of the neon light-absorbing dye 3 can be further prevented.

[Other layers: Functional layers]
The PDP contrast enhancement filter 10 according to the present invention may appropriately include other layers other than the above-described layers. For example, a functional layer. As the functional layer, various functional layers in a display front filter such as a conventionally known contrast enhancement filter can be appropriately employed. Such functional layers can be broadly classified into an optical functional layer responsible for optical functions and a non-optical functional layer responsible for functions other than optical functions. Examples of optical functional layers include layers other than the neon light absorbing layer, such as a near infrared absorbing layer that absorbs near infrared rays, an ultraviolet absorbing layer that absorbs ultraviolet rays, or a display image that gives a visual effect. A color correction layer for correcting the color tone, an antireflection layer (antiglare, antireflection, antiglare and antireflection).

  Examples of non-optical functional layers include an electromagnetic wave shielding layer that shields electromagnetic waves from the display panel, a surface protective layer and a hard coat layer that protect the surface, an antistatic layer, a pollution prevention layer, an impact resistant layer, and two layers. There are a barrier layer for preventing mass transfer and an adhesive layer (including a pressure-sensitive adhesive layer) that adheres the two layers.

  Each layer of the optical functional layer and the non-optical functional layer may be a single layer that also functions, or may be shared between the optical functional layer and the non-optical functional layer. The functional layer may also be used as the light transmission part 2 a and the neon light absorption layer 3 in the contrast enhancement layer 2.

  Further, the functional layer includes the other surface of the transparent substrate 1 (the surface on which the contrast improving layer 2 is not formed), the surface of the neon light absorbing layer 3 between the transparent substrate 1 and the contrast improving layer 2, Any one or more positions can be provided. The configuration provided between the contrast enhancement layer 2 and the neon light absorption layer 3 does not correspond to the PDP contrast enhancement filter 10.

  For example, the contrast enhancement filter 10 for PDP illustrated in FIG. 2 is a form example having the functional layer 4 on the other surface above the transparent substrate 1, and the functional layer 4 is the outermost surface on the viewer V side. And an antireflection layer, a protective layer, and the like.

  Further, the PDP contrast enhancement filter 10 in the plasma display device 100 illustrated in FIG. 4 has a form in which the neon light absorption layer 3 also functions as an adhesive layer. Moreover, in the same figure, it is also an example which has the functional layer 4 as an antireflection layer etc. in the other surface above the drawing of the transparent base material 1.

B. Manufacturing method of contrast enhancement filter for PDP:
In the method for manufacturing a contrast improving filter for PDP according to the present invention, a transparent substrate 1 and a plurality of grooves formed in one surface of the transparent substrate 1 as illustrated in FIG. A contrast improving layer 2 having a light transmitting portion 2a arranged in parallel and a light absorbing portion 2b formed in the groove of the light transmitting portion, and a neon light absorbing dye formed adjacent to the contrast improving layer 2 A contrast enhancement filter 10 for PDP having the neon light absorption layer 3 is manufactured. Hereinafter, a description will be given with reference to FIG.

The method for manufacturing a contrast enhancement filter for PDP according to the present invention includes at least the following steps (a) to (c).
(A) A resin composition 2aa containing a photopolymerizable compound and a photopolymerization initiator is cured by photopolymerization by light irradiation using a molding die M, and the surface has a reverse concavo-convex shape opposite to the light absorbing portion 2b. Are formed on the transparent substrate 1 {see FIG. 3 (A) and FIG. 3 (B)}.
(B) Next, the concave portion 2bb is filled with a dark resin composition containing a light-absorbing colorant, a photopolymerizable compound, and a photopolymerization initiator having a molecular weight of 400 or more, and photopolymerization by light irradiation is performed. The contrast enhancing layer 2 is formed by curing to form the light absorbing portion 2b {see FIG. 3C}.
(C) Next, the neon light absorption layer 3 is formed on the surface of the contrast enhancement layer 2 to obtain the contrast enhancement filter 10 (see FIG. 3D).

  Since the composition and properties of the light transmission part, the light absorption part, and the neon light absorption layer are as described in the above-mentioned “A. Contrast improvement filter for PDP”, detailed description is omitted here.

  Except for this point, the formation method of the contrast enhancement layer 2 itself and the formation method of the neon light absorption layer 3 itself may be a conventionally known method. The contrast improving layer 2 is formed by a so-called photopolymer method (also called 2P method) formed by photopolymerizing a photopolymerizable compound. In the photopolymer method, if a cylindrical mold is used, the transparent base material 1 can be continuously molded while being supplied as a continuous sheet, and this is a molding method with excellent productivity.

  The method for forming the light absorbing portion 2b in the recess 2bb formed on the surface of the light transmitting portion 2a is not particularly limited, but can be easily formed using a so-called Wi-Pink method. Under the present circumstances, it is preferable to use the photoinitiator which has a molecular weight of 400 or more for the photoinitiator in the resin composition for forming the light transmissive part 2a similarly to the light absorption part 2b.

  The neon light-absorbing layer 3 is formed by applying a composition containing a neon light-absorbing dye in a binder resin to the surface of the contrast improving layer 2 and solidifying it by drying or curing.

[Other processes]
In the method for manufacturing a contrast enhancement filter for PDP according to the present invention, in addition to the above steps, other steps may be provided without departing from the gist of the present invention. For example, it is a step of forming other layers such as the above-described functional layer.

C. Plasma display device:
In the plasma display device according to the present invention, like the plasma display device 100 shown in the embodiment of FIG. 4, the PDP contrast enhancement filter 10 as described above is arranged on the surface of the plasma display panel 20 on the viewer V side. This is an image display device having a configuration.

  In addition to the plasma display panel 20 and the PDP contrast enhancement filter 10, the plasma display device 100 includes a display driving circuit, wiring for connecting the driving circuit and the display panel, and a chassis or a unit that integrates them into a panel module. Depending on the use of the frame and the display device, for example, in the case of a television receiver, various known input / output components such as a tuner can be provided, and a housing (cabinet) for storing these can be provided. . These other components are not particularly limited, and depend on the application.

  By using the plasma display device 100 having such a configuration, an effect based on the above-described contrast enhancement filter for PDP 10 can be obtained. As a result, the neon light absorption performance of the contrast enhancement filter for PDP 10 does not deteriorate with time, so that the display device with little deterioration in the quality of the display image with time is obtained.

D. Variations:
The contrast enhancement filter 10 for PDP, the manufacturing method thereof, and the plasma display device 100 using the same according to the present invention may include components other than those described above without departing from the gist of the present invention. Further, the above-described constituent elements may be modified other than the above.

  For example, the cross-sectional shape of the light absorbing portion 2b is a triangular shape having a straight line around the entire periphery in the embodiment illustrated in FIG. 1 and has a wedge shape, but may have other shapes. The cross-sectional shape may be a trapezoidal shape, a pentagonal shape, a hexagonal shape, or the like. Alternatively, a shape in which both or one of the triangles, trapezoids, etc. or one of the hypotenuses are bent or curved (convex shape or concave shape toward the outside of the light absorbing portion 2b), or the like may be used.

  Moreover, even if the transparent base material layer 1 side (upper side in FIG. 1) of the light absorbing portion 2b is rounded with a smooth continuous curve having no cusp in a convex shape toward the outside of the light absorbing portion 2b. good.

  Moreover, the light absorption part 2b is an isosceles triangular wedge shape, and the direction of the tip of the wedge shape may be the observer V side as shown in FIG. 1, or vice versa.

  Moreover, although the direction of the contrast improvement layer 2 and the transparent base material 1 illustrated the transparent base material 1 side in the observer V side in FIG. 1, this may be reverse.

  Further, in FIG. 1 and the like, the light absorbing portion 2b is a columnar object in a stereoscopic view, and the extending direction is parallel to the surface direction, and a large number of the light absorbing portions 2b are arranged at intervals. It may be configured in a lattice shape in the direction.

  As described above, the viewing angle is adjusted by adjusting the traveling direction of the image light from the display panel by variously adjusting the cross-sectional shape of the light absorbing portion 2b and the shape relationship between the light absorbing portion 2b and the light transmitting portion 2a. Or the amount of light absorption with respect to various angle components of external light can be adjusted.

  Further, the contrast improving layer 2 can have a contrast improving effect, but it is also possible to emit image light with a viewing angle narrowed down to a specific direction such as the front direction. Also, it may have a function as a peep prevention filter.

E. Use:
The contrast enhancement filter for PDP according to the present invention is suitably used for applications arranged on the observer side of a plasma display panel in various plasma display devices.

  Such a plasma display device according to the present invention is suitable as an image display device for television receivers, measuring equipment and instruments, office equipment, medical equipment, computer equipment, electronic signage, and game equipment.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not construed as being limited to the contents of the following examples.

Example 1
In the configuration as illustrated in FIG. 2, the transparent substrate 1, the contrast improving layer 2 formed on one surface of the transparent substrate 1, and neon light absorption formed adjacent to the contrast improving layer 2 A contrast improving filter 10 for PDP having the layer 3 and the functional layer 4 formed on the opposite surface of the transparent substrate 1 was produced as follows. The neon light absorbing layer 3 is a layer that also serves as an adhesive layer, and the functional layer 4 is an antireflection layer.

<Formation of antireflection layer>
First, as a transparent substrate 1, a transparent, biaxially stretched polyethylene terephthalate film (made by Teijin Ltd., Tetron (registered trademark) film, HB type) having a thickness of 100 μm is prepared. An antireflection layer composed of a high refractive index layer and a low refractive index layer was formed as a functional layer 4 on one side. Here, the high refractive index layer is a film in which a dry film thickness is 3 μm of a composition (trade name: KZ7973, manufactured by JSR Corporation) in which zirconia ultrafine particles are dispersed in a photocurable resin that is cured with ultraviolet rays. It is a cured product having a refractive index of 1.69 obtained by applying to a surface, drying, and irradiating with ultraviolet rays. On the other hand, the low refractive index resin layer is formed on the high refractive index layer so that the film thickness after drying a photo-curing resin (trade name: TM086, manufactured by JSR Corporation) that is cured with a fluororesin ultraviolet is 100 nm. It is a cured product having a refractive index of 1.41 obtained by applying to the substrate, drying, and irradiating with ultraviolet rays.

<Preparation of dark resin composition for forming light absorbing portion>
As a photocurable prepolymer, ethylene oxide, 2,2 ′-[(1-methylethylidene) bis (4,1-phenyleneoxymethylene)] bis-, homopolymer, 20.0 parts by mass of di-2-propenoate, As reactive diluent monomers, 20.0 parts by mass of 2-phenoxyethyl acrylate, 20.0 parts by mass of α-acryloyl-ω-phenoxypoly (oxyethylene), and 2- {2- [2- (acryloyloxy) ( Methyl) ethoxy] (methyl) ethoxy} (methyl) ethyl acrylate 13.0 parts by mass and, as a light-absorbing color material, acrylic crosslinked fine particles containing 25% carbon black having an average particle size of 4.0 μm (Gantz Kasei Co., Ltd.) 20.0 parts by mass) and a mold release agent, tetradecanol-ethylene oxide 10 mol adduct phosphorus 0.05 parts by mass of ester (monoester / diester = molar ratio 1/1), 0.05 parts by mass of 15 mol of stearylamine ethylene oxide adduct, and 1- [4- (4-benzoylphenyl) as a photopolymerization initiator Sulfanyl) phenyl] -2-methyl-2- (4-methylphenylsulfonyl) propan-1-one (molecular weight: 482, melting point: 110-113 ° C., DKSH Corporation, trade name: ESACURE1001M) 3 parts by mass and ethyl -4- (Dimethylamino) benzoate (manufactured by DKSH, trade name: Luna EDB) 1.5 parts by mass was mixed and homogenized to obtain a dark resin composition for forming a light absorption part. The composition excluding the light-absorbing colorant of the dark resin composition for forming the light-absorbing part was applied at a thickness of 10 μm, and cured by irradiating with 800 mJ / cm 2 of ultraviolet light from a high-pressure mercury lamp. It was 1.547 when the refractive index of 589 nm was measured using Abbe refractometer DR-M4 (product made from Atago Co., Ltd.).

<Preparation of resin composition for forming light transmitting portion>
In the preparation of the dark resin composition for forming the light absorbing portion, a resin composition for forming the light transmitting portion was obtained in the same manner except that the light absorbing colorant was not added.

<Formation of contrast enhancement layer>
On the other surface of the transparent substrate 1 on which the antireflection layer 4 is formed, a resin composition for forming a light transmission part is used to perform continuous molding with a molding die, and an ultraviolet source (Fusion UV Systems).・ Japan Corporation, D bulb, strong output in the vicinity of wavelength 350 nm to 450 nm) is irradiated with ultraviolet rays to form the light transmission part 2a and in parallel with a space on the surface of the light transmission part 2a. Many wedge-shaped grooves were formed.

  Next, after filling the wedge-shaped groove with the dark resin composition for forming the light absorbing portion obtained above and scraping off the excess dark resin composition with a metal doctor blade, the same ultraviolet light source ( The dark resin composition was cured by irradiating ultraviolet rays with a D bulb) to form a light absorbing portion 2b, and a contrast improving layer 2 was obtained.

<Formation of neon light absorption layer>
Acrylic adhesive (pressure-sensitive adhesive, solid content 27%, manufactured by Toyo Ink Manufacturing Co., Ltd., trade name: Olivevine BPS6271) 99.7 parts by mass, and curing agent (manufactured by Toyo Ink Manufacturing Co., Ltd., trade name: BXX5627) To 0.3 part by mass, 0.01 part by mass of a neon light absorbing compound (Yamada Chemical Industry Co., Ltd., trade name: TAP2) was blended. Further, 4 parts by weight of an ultraviolet absorber (made by Cytec, trade name: CyasorbUV24), 2 parts by weight of a light stabilizer (made by BASF Corp., trade name: TINUVINN144), and a layered clay mineral (made by Kunimine Industries, trade name) : Kunipia D36) 0.05 parts by mass was blended to obtain a mixture. This mixture was sufficiently stirred to prepare a resin composition for forming a neon light absorption layer.

  This resin composition was applied on a middle peelable release film (trade name: E7007, manufactured by Toyobo Co., Ltd.) with a thickness of 38 μm to a thickness of 25 μm, and dried at 100 ° C. for 2 minutes to form a coating film. After that, a 38 μm lightly peelable release film (trade name: E7005, manufactured by Toyobo Co., Ltd.) was laminated on this coating film to produce an optical filter layer having adhesiveness provided between the release films. .

<Preparation of contrast enhancement filter for PDP>
The light peelable release film of the optical filter layer was peeled off and bonded to the surface of the contrast improving layer 2 to produce a target contrast improving filter for PDP.

Example 2
Dimer of oligo [2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propane] as a photopolymerization initiator in the dark resin composition for forming a light absorption part of Example 1 (Molecular weight: 436, melting point: 100 to 110 ° C., manufactured by DKSH Corporation, trade name: ESACURE ONE) A contrast improving filter for PDP was produced in the same manner as in Example 1 except that 3 parts by mass were used.

Example 3
In the dark resin composition for forming a light absorbing portion of Example 1, a trimer of oligo [2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propane] as a photopolymerization initiator (Molecular weight: 639, manufactured by DKSH Corporation, trade name: ESACURE KIP150) A contrast improving filter for PDP was produced in the same manner as in Example 1 except that 3 parts by mass were used.

Example 4
In the dark resin composition for forming a light transmission part of Example 1, pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (BASF Corporation) as an antioxidant. Manufactured, trade name: Irganox 1010) A contrast improving filter for PDP was produced in the same manner as in Example 1 except that 1 part by mass was further added.

<< Comparative Example 1 >>
In the dark resin composition for forming the light absorption part of Example 1, 1-hydroxy-cyclohexyl-phenyl-ketone (molecular weight: 204.3, melting point: 45-49 ° C., manufactured by BASF Corporation, product as a photopolymerization initiator Name: Irgacure 184) A contrast improving filter for PDP was produced in the same manner as in Example 1 except that 3 parts by mass were used.

<< Comparative Example 2 >>
In the dark resin composition for forming the light absorption part of Example 1, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (molecular weight: 366.5, as a photopolymerization initiator) Melting point: 110 to 114 ° C., manufactured by BASF Corporation, trade name: Irgacure 369) A contrast improving filter for PDP was produced in the same manner as in Example 1 except that 3 parts by mass was used.

<Performance evaluation>
The durability of the neon light absorption layer was evaluated using the PDP contrast enhancement filters of Examples 1 to 4 and Comparative Examples 1 and 2. The evaluation was performed by a light resistance test. Then, the amount of change in transmittance in the neon light absorption band and the degree of change in transmission chromaticity of the filter before and after the start of the test were examined.

<Light resistance test>
A xenon lamp with an output of 550 W / m ² was irradiated onto the contrast enhancement filter for PDP and left in an environment of 63 ° C. for 140 hours.

<Spectroscopic evaluation and transmission chromaticity evaluation>
The transmittance before and after the test was measured using a spectrophotometer (trade name: UV2200, manufactured by Shimadzu Corporation), and the change in transmittance in the neon light absorption band was evaluated at a wavelength of about 592 nm, which is a substantially central wavelength. . The near-infrared absorption function was evaluated by the amount of change in transmittance before and after the test at a wavelength of 850 nm as a representative wavelength in the near-infrared absorption band. The amount of change in transmittance before and after the test was determined by the following formula.
Change in transmittance (%) = transmittance after test−transmittance before test

  In addition, the transmission chromaticity before and after the test was measured using a spectrophotometer (trade name: UV-3600, manufactured by Shimadzu Corporation), and the transmission chromaticity (Δx) according to JIS Z8701 was measured as a change in hue. , Δy), changes in Δx and Δy were also calculated. If the amount of change in Δx and Δy exceeds 0.015, color change due to long-term use is large, which is not preferable.

  The results of the performance evaluation are shown in Table 1.

DESCRIPTION OF SYMBOLS 1 Transparent base material 2 Contrast improvement layer 2a Light transmission part 2b Light absorption part 3 Neon light absorption layer 4 Functional layer 10 Contrast improvement filter for PDP 20 Display panel (PDP)
100 Plasma display device M Mold D V Observer

Claims (16)

A transparent base material, a light transmission part formed on one surface of the transparent base material, in which a plurality of grooves are arranged in parallel in the surface direction, and a light absorption part formed in the groove of the light transmission part A contrast enhancing filter for PDP, comprising: a contrast enhancing layer; and a neon light absorbing layer formed adjacent to the contrast enhancing layer and containing a neon light absorbing dye,
Curing in which at least the light absorption part of the contrast enhancement layer is formed by photopolymerizing a dark resin composition containing a light absorbing colorant, a photopolymerizable compound, and a photopolymerization initiator having a molecular weight of 400 or more. Contrast improvement filter for PDP which consists of things.   The contrast enhancement filter for PDP according to claim 1, wherein the photopolymerization initiator includes three or more phenyl groups or derivatives thereof in the chemical structure.   The photopolymerization initiator includes 1- [4- (4-benzoylphenylsulfanyl) phenyl] -2-methyl-2- (4-methylphenylsulfonyl) propan-1-one, and oligo [2-hydroxy-2- The contrast enhancement filter for PDP according to claim 1 or 2, selected from the group consisting of a dimer and a trimer of methyl-1- [4- (1-methylvinyl) phenyl] propane].   The contrast enhancement filter for PDP according to any one of claims 1 to 3, wherein the dark resin composition further comprises an aminobenzoate polymerization accelerator.   The contrast enhancement filter for PDP according to claim 4, wherein the aminobenzoate polymerization accelerator is at least one selected from the group consisting of ethyl-4- (dimethylamino) benzoate and ethylhexyl-4-dimethylaminobenzoate. .   The contrast enhancement filter for PDP according to any one of claims 1 to 5, wherein the dark resin composition further comprises an ultraviolet absorber.   The contrast enhancement filter for PDP according to any one of claims 1 to 6, wherein the dark resin composition further comprises an antioxidant.   The functional layer is further provided at any one or more positions on the other surface of the transparent substrate, between the transparent substrate and the contrast improving layer, or on the surface of the neon light absorbing layer. The layers are a near-infrared absorbing layer, an ultraviolet absorbing layer, a color correction layer, an antireflection layer, an electromagnetic wave shielding layer, a surface protective layer, a hard coat layer, an antistatic layer, an antifouling layer, an impact resistant layer, a barrier layer, and an adhesive. The contrast improvement filter for PDP according to any one of claims 1 to 7, which is at least one selected from the group consisting of layers. A transparent base material, a light transmission part formed on one surface of the transparent base material, in which a plurality of grooves are arranged in parallel in the surface direction, and a light absorption part formed in the groove of the light transmission part A method for producing a contrast enhancing filter for PDP, comprising: a contrast improving layer; and a neon light absorbing layer formed adjacent to the contrast improving layer and containing a neon light absorbing dye.
(A) A resin composition containing a photopolymerizable compound and a photopolymerization initiator is cured by photopolymerization by light irradiation, and a light transmitting portion having a large number of concave portions having a concave and convex shape opposite to the light absorbing portion on the surface. Formed on a transparent substrate,
(B) Next, the concave portion is filled with a dark resin composition containing a light-absorbing colorant, a photopolymerizable compound, and a photopolymerization initiator having a molecular weight of 400 or more, and cured by photopolymerization by light irradiation. By forming a light absorption part, a contrast enhancement layer is formed,
(C) Next, a neon light absorbing layer containing a neon light absorbing dye is formed on the surface of the contrast improving layer.
A method of manufacturing a contrast enhancement filter for PDP.   The method for producing a contrast enhancement filter for PDP according to claim 9, wherein the photopolymerization initiator includes three or more phenyl groups or derivatives thereof in a chemical structure.   The photopolymerization initiator includes 1- [4- (4-benzoylphenylsulfanyl) phenyl] -2-methyl-2- (4-methylphenylsulfonyl) propan-1-one, and oligo [2-hydroxy-2- The method for producing a contrast enhancement filter for PDP according to claim 9 or 10, wherein the method is selected from the group consisting of a dimer and a trimer of methyl-1- [4- (1-methylvinyl) phenyl] propane].   The method for producing a contrast enhancement filter for PDP according to any one of claims 9 to 11, wherein the dark resin composition further comprises an aminobenzoate polymerization accelerator.   The contrast enhancement filter for PDP according to claim 12, wherein the aminobenzoate polymerization accelerator is at least one selected from the group consisting of ethyl-4- (dimethylamino) benzoate and ethylhexyl-4-dimethylaminobenzoate. Manufacturing method.   The method for producing a contrast improving filter for PDP according to any one of claims 9 to 13, wherein the dark color resin composition further contains an ultraviolet absorber.   The manufacturing method of the contrast improvement filter for PDP as described in any one of Claims 9-14 in which the said dark color resin composition further contains antioxidant.   The PDP contrast enhancement filter according to any one of claims 1 to 8, or the PDP contrast enhancement filter obtained by the production method according to any one of claims 9 to 15, wherein the plasma display panel has a contrast enhancement filter. A plasma display device provided on the observer side.

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