JP2012027089A - Optical filter for display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical filter for a display which exhibits a sufficient near infrared ray shield effect or the like, and is suppressed in deterioration of pigment without an expensive cost, and includes an adhesive layer containing the predetermined pigment for a near infrared ray shield or the like.SOLUTION: An optical filter 20 for a display comprises an phthalocyanine-based pigment, a fine particle 19 having an average particle diameter of 0.1-20 μm, and an adhesive layer 12 containing an adhesive.

Description

  The present invention relates to an optical filter for a display used in an image display unit of a display such as a plasma display panel (PDP), a cathode ray tube (CRT) display, a liquid crystal display, an organic EL (electroluminescence) display, and in particular, has a near infrared shielding function. The present invention relates to an optical filter for display.

  In a display such as a plasma display panel (PDP), an optical filter is usually installed on the front surface (viewer side). The optical filter is used for the purpose of cutting near infrared rays, improving color reproducibility (emission color purity improvement), electromagnetic wave shielding, improving bright contrast (antireflection), protecting the light emitting panel, blocking heat from the light emitting panel, and the like.

  In particular, the near-infrared light emitted from the PDP light-emitting panel needs to be reduced in order to avoid malfunctioning a remote controller used for home television, video, or the like. In addition, the electromagnetic waves emitted by the PDP light-emitting panel must be suppressed in order to avoid adverse effects on the human body and precision equipment. Further, in order to make the light emitted from the light emitting panel of the PDP feel a natural color for human vision, there is a demand for improvement in color reproducibility (light emission color purity improvement) by correction with a filter. Furthermore, it is desirable that the display on the display be visually recognized with sufficient contrast without being hindered by reflection of light from the outside even in a bright place such as a bright room. In addition, even when the display product is directly touched by hand, it is desirable that the heat generated by the light emitting panel of the PDP is cut off in order to avoid a situation where the user is surprised by the high temperature.

  As an optical filter for PDP that meets the above-mentioned purpose, it is generally a function to cut off unnecessary light (light having a wavelength of 560 to 610 nm) due to neon emission for antireflection, near infrared shielding, electromagnetic wave shielding, and color reproducibility improvement. Optical filters having various functions such as (neon cut function) are used. For example, those having a near-infrared shielding function that can shield near-infrared rays in a wide range of wavelengths and that contain cesium-containing tungsten oxide with high visible light transmittance, and those that contain cyanine dyes or phthalocyanine dyes have been developed. (Patent Documents 1 and 2). Moreover, what contains the squarylium type compound and azaporphyrin type compound which have the selective absorption function of a specific wavelength as what has a neon cut function is disclosed (patent document 3).

  In general, an optical filter for PDP is applied to a functional layer having various functions (generally, a coating solution in which the above-described compound or the like is dispersed or dissolved in a thermosetting resin composition, an ultraviolet curable resin composition, or the like is applied on a film. , Cured and formed) a plurality of times and laminated, or an optical filter having one or a plurality of functions is appropriately combined and bonded via an adhesive layer. When the structure of the optical filter becomes complicated in this way, the process of laminating and applying various functional layers and the process of bonding a plurality of optical filters become complicated, which not only increases the manufacturing cost but also increases the optical filter. This will increase the weight and thickness.

  In recent years, optical filters have been required to be lighter and thinner. As a means for that, it is conceivable to reduce the number of functional layers to be laminated in the optical filter and the number of filters to be bonded to simplify the configuration. For example, Patent Document 4 discloses a technique for containing a dye or the like in an adhesive layer. By providing a function to the pressure-sensitive adhesive layer that is always used for bonding the optical filter, the configuration of the optical filter can be simplified.

JP 2007-21998 A JP 2003-114323 A Japanese Patent Laid-Open No. 2005-92196 JP 2009-271514 A JP 2010-60617 A

  However, as a result of studies by the present inventors, it has been found that when a pigment or the like is included in the pressure-sensitive adhesive layer, the pigment or the like may be easily deteriorated as compared with the case where it is blended with the above-described thermosetting resin or the like. . In general, it is considered that in a pressure-sensitive adhesive layer having a low glass transition point, deterioration of a pigment or the like is likely to occur due to contact with a pressure-sensitive adhesive component, a residue component, a decomposition component, or the like.

  Patent Document 5 discloses a technique for stabilizing a dye by using resin fine particles containing a near-infrared absorbing dye or the like in a hard coat layer or an adhesive layer. However, in this method, the production of resin fine particles containing a dye is complicated and expensive, and the dispersibility of the dye depends on the dispersibility of the fine particles. The point becomes.

  Accordingly, an object of the present invention is an optical filter for a display having a pressure-sensitive adhesive layer containing a specific dye for shielding near infrared rays, which exhibits a sufficient near infrared shielding effect and costs high. An object of the present invention is to provide an optical filter for display in which the deterioration of the pigment is suppressed without any problems.

  The above-described object is achieved by an optical filter for display, comprising an adhesive layer containing a phthalocyanine dye, fine particles having an average particle diameter of 0.1 to 20 μm, and an adhesive.

  By blending a phthalocyanine dye, a sufficient near-infrared shielding function is imparted to the pressure-sensitive adhesive layer. And by mix | blending the microparticles | fine-particles of said average particle diameter, deterioration of a phthalocyanine series pigment | dye can be suppressed, without using a complicated means. Although the mechanism of this action is not clear, the presence of fine particles suppresses the decomposition of the adhesive component and residue component due to heat, etc., and the contact area between the phthalocyanine dye and the adhesive decreases, resulting in adhesion It is conceivable that the degradation of the phthalocyanine dye due to the decomposition product of the adhesive component and the residue component is suppressed, and that fine particles adsorb the decomposition product of the adhesive component and the residue component. Moreover, if it is microparticles | fine-particles of the said average particle diameter, the raise of the haze (cloudiness value) of the optical filter for displays will be suppressed.

  Preferred embodiments of the optical filter for display according to the present invention are as follows.

(1) The fine particles are transparent resin fine particles or silica fine particles. Thereby, the raise of the haze by microparticles | fine-particles can further be suppressed.
(2) The transparent resin fine particles are at least one kind of fine particles selected from the group consisting of cross-linked (meth) acrylic resin fine particles, cross-linked styrene resin fine particles, cross-linked (meth) acryl-styrene copolymer fine particles, and melamine resin fine particles. is there.
(3) The content of the fine particles is 0.1 to 20% by mass based on the nonvolatile content of the pressure-sensitive adhesive layer. Thereby, deterioration of a phthalocyanine pigment | dye can further be suppressed and the fall of the adhesive force of the adhesive layer by containing microparticles | fine-particles hardly arises.
(4) The phthalocyanine dye has a maximum absorption wavelength at 750 to 950 nm.
Thereby, a more effective near-infrared shielding effect can be obtained.
(5) The pressure-sensitive adhesive is an acrylic resin-based pressure-sensitive adhesive.
(6) For plasma display panels.

  According to the optical filter for display of the present invention, since a phthalocyanine dye is blended in the pressure-sensitive adhesive layer, a sufficient near-infrared shielding function is obtained with a simplified layer structure. Further, since the deterioration of the phthalocyanine dye is suppressed without increasing the haze of the optical filter by blending the predetermined fine particles, it is possible to obtain an optical filter for display with high weather resistance without incurring high costs. .

It is a schematic sectional drawing which shows a typical example of the optical filter for displays of this invention. It is a schematic sectional drawing which shows an example of the suitable aspect of the optical filter for displays of this invention.

  The optical filter of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view showing a typical example of an optical filter for display according to the present invention.

  As shown in FIG. 1, the optical filter for display 20 of the present invention includes a phthalocyanine dye, fine particles 19 having an average particle diameter of 0.1 to 20 μm, and an adhesive on the surface of a rectangular transparent plastic film 11. Layer 12 is formed.

  The phthalocyanine-based dye is useful as a near-infrared shielding agent in that it can perform near-infrared shielding without deteriorating the color tone of an image because it has a large absorption in the near-infrared region and a small absorption in the visible light region. Usually, when using a phthalocyanine-type pigment | dye, a near-infrared shielding layer is separately formed by coating and hardening using the coating liquid mix | blended with the thermosetting resin composition. By providing the pressure-sensitive adhesive layer with a near-infrared shielding function as in the present invention, the layer configuration can be simplified. However, when a phthalocyanine dye is blended in the pressure-sensitive adhesive layer, the phthalocyanine dye may be easily deteriorated. This is considered to be because, in a pressure-sensitive adhesive layer generally having a low glass transition point, the phthalocyanine dye is deteriorated by contact with a pressure-sensitive adhesive component, a residue component, a decomposition component, or the like.

  In the present invention, the blending of the fine particles 19 suppresses the deterioration of the phthalocyanine dye. Although this mechanism of action is not clear, the presence of the fine particles 19 in the pressure-sensitive adhesive layer 12 suppresses the decomposition of the pressure-sensitive adhesive component and the residual component due to heat and light, and the phthalocyanine dye and the pressure-sensitive adhesive. It is conceivable that the contact area is reduced, the degradation of the phthalocyanine dye due to the decomposition product of the pressure-sensitive adhesive component and the residue component is suppressed, and the fine particles adsorb the decomposition product of the pressure-sensitive adhesive component and the residue component.

  If the pressure-sensitive adhesive layer 12 does not deteriorate the effect of, for example, impairing the stability of the phthalocyanine dye, a near-infrared shielding agent other than the phthalocyanine dye, a neon cut dye, a color tone adjusting agent, a transmittance adjusting agent, etc. May be included.

  Further, as shown in FIG. 1, the adhesive layer 12 is generally formed on the surface of a transparent substrate such as a transparent plastic film 11 and bonded to a display panel body such as a PDP, a glass substrate, and another plastic film. Used for However, the optical filter for display according to the present invention only needs to have the pressure-sensitive adhesive layer 12 containing a phthalocyanine-based pigment and the like, and the transparent plastic film 11 may be omitted. For example, release sheets may be provided on both sides of the pressure-sensitive adhesive layer 12 and used as an independent optical filter for display in the form of a pressure-sensitive adhesive sheet.

  Usually, as will be described later, other functional layers having various functions are combined and used as an optical filter for display according to the application.

[Fine particles]
In the present invention, the fine particles 19 may have an average particle diameter of 0.1 to 20 μm as described above. Fine particles having this average particle diameter exhibit an effect of suppressing deterioration of the phthalocyanine dye, and suppress an increase in haze of the optical filter for display. When the average particle size of the fine particles is larger than 20 μm, the haze of the display optical filter 20 may increase due to light scattering. The average particle size of the fine particles 19 is preferably 0.1 to 10 μm, and more preferably 0.5 to 5 μm.

  The fine particles are not particularly limited, and organic or inorganic fine particles can be used as appropriate. Organic fine particles include crosslinked or non-crosslinked acrylic resins (polymethyl methacrylate (PMMA), etc.), styrene resins, (meth) acrylate-styrene copolymers, melamine resins (melamine-formaldehyde condensates (usually) And fine particles such as polycarbonate resin and urethane resin. Examples of the inorganic fine particles include fine particles of silica, alumina, aluminosilicate, kaolinite, calcium carbonate, barium sulfate, glass and the like. These fine particles may have either hydrophobic or hydrophilic surface characteristics, and may be used alone or in combination.

  These fine particles preferably have no reactivity with the phthalocyanine dye so as not to promote deterioration of the phthalocyanine dye or increase haze.

  In the present invention, since the fine particles do not increase haze more, transparent fine particles are preferable, and transparent resin fine particles or silica fine particles are preferable. Further, the refractive index of the fine particles is preferably close to the refractive index of the pressure-sensitive adhesive (for example, the refractive index difference is about ± 0.1).

  In the case of transparent resin fine particles, those made of a resin having a crosslinked structure are preferable so as not to dissolve in the composition of the pressure-sensitive adhesive layer. That is, fine particles such as a crosslinked acrylic resin, a crosslinked styrene resin, a crosslinked (meth) acrylate-styrene copolymer, and a melamine resin are preferable.

  Examples of the silica fine particles include silica fine particles such as amorphous fumed silica, hydrophobic fumed silica, hydrophilic fumed silica, hydrophobic wet method silica, and hydrophilic wet method silica.

  Although there is no restriction | limiting in particular in the content rate of the microparticles | fine-particles 19, 0.1-20 mass% is preferable on the basis of the non volatile matter of the adhesive layer 12. FIG. Thereby, deterioration of a phthalocyanine pigment | dye can further be suppressed. When the content of the fine particles 19 is less than 0.1% by mass, the effect may not be obtained. When the content is more than 20% by mass, the adhesiveness of the pressure-sensitive adhesive layer 12 may decrease. The content of the fine particles 19 is more preferably 1 to 10% by mass, and particularly preferably 1 to 5% by mass based on the nonvolatile content of the pressure-sensitive adhesive layer 12.

[Phthalocyanine dye]
In the present invention, the phthalocyanine dye is not particularly limited, but a phthalocyanine dye represented by the following formula (I) is preferable.

In formula (I), A ^{1 to} A ¹⁶ are each independently a hydrogen atom, a halogen atom, a hydroxyl group, an amino group, a carboxyl group, a hydroxysulfonyl group, an aminosulfonyl group, a thiol group, and may be substituted. It represents any of substituents such as an alkyl group having 1 to 20 carbon atoms, an alkoxy group, an aryl group having 6 to 20 carbon atoms, and an aryloxy group. The substituent having 1 to 20 carbon atoms may contain at least one of a nitrogen atom, a sulfur atom, an oxygen atom, and a halogen atom. Moreover, two adjacent substituents may be connected via a linking group. However, at least four of A ^{1 to} A ¹⁶ are at least one of a substituent via a sulfur atom and a substituent via a nitrogen atom. M ¹ represents any one of two hydrogen atoms, a divalent metal atom, a trivalent or tetravalent substituted metal atom, and an oxy metal.

Examples of the halogen atom of A ^{1 to} A ¹⁶ in the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group include linear, branched or branched groups such as methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, t-butyl group, n-hexyl group, cyclohexyl group and 2-ethylhexyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propyloxy group, an iso-propyloxy group, an n-butyloxy group, a t-butyloxy group, an n-hexyloxy group, and a cyclohexyloxy group. , A straight chain, branched or cyclic alkoxy group such as 2-ethylhexyloxy group, and the aryl group includes a phenyl group, a naphthyl group, and the like. In addition, examples of the substituent include aryloxy groups such as phenoxy group and naphthoxy group, aralkyl groups such as benzyl group and phenethyl group, aralkyloxy groups such as benzyloxy group and phenethyloxy group, methylthio group, n-pentylthio group, and cyclohexyl. Alkylthio groups such as thio groups, arylthio groups such as phenylthio groups, aralkylthio groups such as benzylthio groups and phenethylthio groups, methylsulfonyl groups, ethylsulfonyl groups, n-propylsulfonyl groups, t-butylsulfonyl groups, cyclohexylsulfonyl groups, Aralkyl sulfo groups such as alkylsulfonyl groups such as n-heptylsulfonyl group and 2-ethylhexylsulfonyl group, arylsulfonyl groups such as phenylsulfonyl group and naphthylsulfonyl group, benzylsulfonyl groups and phenethylsulfonyl groups Alkyl group, methylcarbonyl group, ethylcarbonyl group, t-butylcarbonyl group, cyclohexylcarbonyl group, 2-ethylhexylcarbonyl group, etc., arylcarbonyl group, alkoxycarbonyl group, aryloxycarbonyl group, alkylcarbonyloxy Groups, arylcarbonyloxy groups, aralkylcarbonyloxy groups, pyrrole groups, imidazole groups, piperidine groups, morpholine groups and other heterocyclic groups.

Examples of the divalent metal atom as the metal M ¹ include Cu (II), Co (II), Zn (II), Fe (II), Ni (II), Ru (II), and Rh (II). ), Pd (II), Pt (II), Mn (II), Mg (II), Ti (II), Be (II), Ca (II), Ba (II), Cd (II), Hg (II ), Pb (II), Sn (II) and the like. Examples of the trivalent substituted metal atom include Al-F, Al-Cl, Al-Br, Al-I, Fe-Cl, Ga-F, Ga-Cl, Ga-I, Ga-Br, and In-F. , In-Cl, In-Br , In-I, Tl-F, Tl-Cl, Tl-Br, Tl-I, Al-C 6 H 5, Al-C 6 H 4 (CH 3), In-C _{6 H 5, In-C 6} H 4 (CH 3), In-C 6 H 5, Mn (OH), Mn (OC 6 H 5), Mn [OSi _{(CH 3)} 3], Ru-Cl, etc. is Can be mentioned. Examples of tetravalent substituted metal atoms include CrCl ₂ , SiF ₂ , SiCl ₂ , SiBr ₂ , SiI ₂ , ZrCl ₂ , GeF ₂ , GeCl ₂ , GeBr ₂ , GeI ₂ , SnF ₂ , SnCl ₂ , SnBr ₂ , TiF ₂ , TiCl ₂ , TiBr ₂ , Ge (OH) ₂ , Mn (OH) ₂ , Si (OH) ₂ , Sn (OH) ₂ , Zr (OH) ₂ , Cr (R ₁ ) ₂ , Ge (R ₁ ) ₂ , Si (R ₁ ) ₂ , Sn (R ₁ ) ₂ , Ti (R ₁ ) ₂ {R ₁ represents an alkyl group, a phenyl group, a naphthyl group, or a derivative thereof} Cr (OR ₂ ) ₂ , _{Ge (OR 2) 2, Si} (OR 2) 2, Sn (OR 2) 2, Ti (OR 2) 2, {R 2 is an alkyl group, a phenyl group, a naphthyl group, a trialkylsilyl group, a dialkyl Alkoxysilyl represents a group or a derivative _{thereof}, Sn (SR 3) 2} , Ge (SR 3) 2 {R 3 is an alkyl group, a phenyl group, a naphthyl group or a derivative thereof}, and the like. Examples of the oxymetal include VO, MnO, TiO and the like. However, it is not limited to these.

  In the present invention, the maximum absorption wavelength of the phthalocyanine dye is not particularly limited, but a phthalocyanine dye having a maximum absorption wavelength at 750 to 950 nm is preferred for use as a near-infrared shielding agent.

[Adhesive]
In the present invention, the adhesive may be any resin as long as it is an adhesive resin. For example, acrylic resin, polyester resin, urethane resin, epoxy resin, phenol resin, silicone resin, polyvinyl butyral (PVB) resin, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, partially saponified ethylene-vinyl acetate Ethylene copolymers such as copolymers, carboxylated ethylene-vinyl acetate copolymers, ethylene- (meth) acryl-maleic anhydride copolymers, ethylene-vinyl acetate- (meth) acrylate copolymers ( “(Meth) acryl” means “acryl or methacryl”), rubber-based adhesives, thermoplastic elastomers such as SEBS and SBS, and the like. In particular, an acrylic resin adhesive is preferable.

  As the constituent component (monomer) of the preferred acrylic resin, the following (meth) acrylic acid alkyl ester, (meth) acrylic acid alkoxyalkyl ester, aromatic ring-containing monomer, hydroxyl group-containing monomer, monomer having a carboxyl group in the molecule, amino Examples thereof include compounds such as group-containing monomers.

Preferable examples of (meth) acrylic acid alkyl ester; (meth) acrylate having a linear or branched alkyl group having 1 to 12 carbon atoms in the molecule, for example, methyl (meth) acrylate, ethyl (meta ) Acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) ) Acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate ((meth) acrylate means both acrylate and methacrylate)In particular, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate are preferable.

Particularly preferred examples of the (meth) acrylic acid alkoxyalkyl ester include methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate.

  Preferred examples of aromatic ring-containing monomers (copolymerizable compounds containing an aromatic group in the molecular structure) include: phenyl acrylate, phenoxyethyl (meth) acrylate, benzyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, ethylene Examples thereof include oxide-modified nonylphenol (meth) acrylate, hydroxyethylated β-naphthol acrylate, biphenyl (meth) acrylate, styrene, vinyltoluene, α-methylstyrene, and the like. In particular, phenyl acrylate, phenoxyethyl (meth) acrylate, benzyl (meth) acrylate, and phenoxydiethylene glycol (meth) acrylate are preferable.

  Examples of hydroxyl-containing monomers include: 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) ) Acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate, chloro-2-hydroxypropyl acrylate, diethylene glycol mono (meth) acrylate, allyl alcohol and the like. In particular, 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are preferable.

  Furthermore, preferable examples of the monomer having a carboxyl group in the molecule include (meth) acrylic acid, 2-carboxyethyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, 4-carboxybutyl (meth) acrylate, and itacon. Examples thereof include acid, crotonic acid, maleic acid, fumaric acid and maleic anhydride. In particular, (meth) acrylic acid is preferred.

  Preferred examples of the amino group-containing monomer include aminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, vinyl pyridine and the like. In particular, dimethylaminoethyl (meth) acrylate is preferable.

  The monomer component is appropriately employed according to the required physical properties.

  In this invention, the compounding quantity of the preferable structural component (monomer) mixture of an acrylic resin is (meth) acrylic-acid alkylester and / or (meth) acrylic-acid alkoxyalkylester: 4.5-89 mass% (especially 22), for example. .7 to 69% by mass), aromatic ring-containing monomer: 10 to 85% by mass (particularly 30 to 70% by mass), hydroxyl group-containing monomer: 1 to 10% by mass (particularly 0.05 to 0.5% by mass), carboxyl Monomers having groups: 0 to 10% by mass (especially 0 to 5% by mass), and amino group-containing monomers 0 to 0.5% by mass (particularly 0 to 0.3% by mass).

  Other monomers may be mixed in the monomer mixture as necessary. Examples of other monomers include epoxy group-containing (meth) acrylates such as glycidyl (meth) acrylate; acetoacetyl group-containing (meth) acrylates such as acetoacetoxyethyl (meth) acrylate; vinyl acetate, vinyl chloride and ( And (meth) acrylonitrile. The mixing ratio of other monomers can be included at a ratio of 0 to 10% by mass.

  The acrylic resin can be produced by a conventionally known polymerization method such as a solution polymerization method, a bulk polymerization method, an emulsion polymerization method and a suspension polymerization method, but does not contain a polymerization stabilizer such as an emulsifier or a suspending agent. What was manufactured by the polymerization method and the block polymerization method is preferable. Moreover, the weight average molecular weight (Mw) by the gel permeation chromatography (GPC) of the said acrylic polymer is 800,000-1,600,000, Preferably it is 800,000-1,500,000. If the Mw is less than 800,000, the cohesive strength of the pressure-sensitive adhesive is not sufficient even when the curing agent is blended in a suitable range, and foaming tends to occur under high temperature conditions, exceeding 1.6 million. And the stress relaxation property of an adhesive tends to fall. It is preferable that ratio (Mw / Mn) of a weight average molecular weight and a number average molecular weight (Mn) is 10-50. Furthermore, it is suitable that it is 20-50. If the ratio (Mw / Mn) becomes too large, the low molecular weight polymer increases and foaming tends to occur. Conversely, if the ratio (Mw / Mn) becomes too small, the stress relaxation property tends to decrease.

  The acrylic resin (adhesive) is preferably used together with a curing agent. Examples of the curing agent include an epoxy compound-based crosslinking agent, an isocyanate compound-based crosslinking agent, a metal chelate compound-based crosslinking agent, an aziridine compound-based crosslinking agent, and an amino resin-based crosslinking agent. Among them, an epoxy compound-based crosslinking agent having two or more epoxy groups in the molecule, an isocyanate compound-based crosslinking agent having two or more isocyanate groups in the molecule, and an aziridine compound-based crosslinking agent are preferable. A crosslinking agent is preferred.

  Examples of the epoxy compound-based crosslinking agent having two or more epoxy groups in the molecule include 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-m— Xylylenediamine, N, N, N ′, N′-tetraglycidylaminophenylmethane, triglycidyl isocyanurate, m-N, N-diglycidylaminophenyl glycidyl ether, N, N-diglycidyl toluidine, N, N -Compounds having two or more epoxy groups such as diglycidyl aniline, pentaerythritol polyglycidyl ether, 1,6-hexanediol diglycidyl ether are preferred.

  Examples of isocyanate compounds include isocyanate monomers such as tolylene diisocyanate, chlorophenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, and the like. Isocyanate compounds, isocyanurates, and burette type compounds obtained by adding these isocyanate monomers with trimethylolpropane and the like, and urethane prepolymer type of addition reaction such as polyether polyol, polyester polyol, acrylic polyol, polybutadiene polyol, polyisoprene polyol, etc. An isocyanate etc. can be mentioned.

  Further, examples of the aziridine compound-based crosslinking agent include trimethylolpropane tri-β-aziridinylpropionate, trimethylolpropane tri-β- (2-methylaziridine) propionate, tetramethylolmethanetri-β-aziridinini. Examples include lupropionate and triethylenemelamine.

  It is preferable that the compounding quantity of the said crosslinking agent is 0.0001-2.0 mass parts with respect to 100 mass parts of acrylic resins. However, when using an epoxy compound type crosslinking agent, 0.0001-0.1 mass part is preferable, and 0.001-0.05 mass part is especially preferable.

  In the present invention, the pressure-sensitive adhesive composition has a transparency, visibility, and an effect that does not impair the effects of the present invention. You may mix | blend provision resin, a plasticizer, an antifoamer, a wettability preparation agent, etc.

[Optical filter for display]
FIG. 2 is a schematic sectional view showing an example of a preferred embodiment of the optical filter for display according to the present invention. The display optical filter shown in FIG. 2 is particularly preferably used as an optical filter for a PDP in which high-frequency pulse discharge is performed on a light emitting portion for image display.

  As shown in the figure, in the display optical filter 30, a mesh-like conductive layer 23 is formed over the entire surface of the rectangular transparent plastic film 21. A hard coat layer 24 made of an ultraviolet curable resin composition is formed thereon, and a high refractive index layer 25 and a low refractive index layer 26 are further formed thereon as an antireflection layer. And the adhesive layer 22 containing the phthalocyanine pigment | dye, the microparticles | fine-particles 29 with an average particle diameter of 0.1-20 micrometers, and an adhesive is formed in the other surface of the surface in which the conductive layer 23 of the transparent plastic film 21 was formed. . As described above, by imparting a near-infrared shielding function to the pressure-sensitive adhesive layer 22, the layer configuration of the display optical filter can be simplified, and deterioration of the phthalocyanine dye due to heat or the like is suppressed.

  The display optical filter 30 has a conductive layer exposed by removing a functional layer such as a hard coat layer around the display optical filter 30 by laser irradiation or the like in order to conduct electricity from the conductive layer 23 to the outside. Or a structure in which a conductive adhesive tape is sandwiched between conductive layers and grounded to the outside (not shown). Moreover, you may provide a peeling sheet on the adhesive layer 22 for handling property improvement.

  In general, the display optical filter 30 is directly attached to the surface of the PDP via the pressure-sensitive adhesive layer 22, or is attached to a glass plate via the pressure-sensitive adhesive layer 22 and disposed on the front surface of the PDP. In the optical filter 30 for display which is a preferred embodiment of the present invention, the adhesive layer 22 contains a phthalocyanine dye and is provided with a near-infrared shielding function. However, as described above, the phthalocyanine dye is deteriorated by heat or the like. It is an optical filter for display that is suppressed and has high weather resistance.

  In general, when the optical filter for display is directly attached to the surface of the PDP, the pressure-sensitive adhesive layer is easily affected by heat generated from the PDP. Even if it exists, degradation of the phthalocyanine pigment | dye contained in the adhesive layer 22 can be suppressed.

  The display optical filter of the present invention may have any configuration as long as it includes the pressure-sensitive adhesive layer 22, and has a configuration other than that shown in FIG. 2, for example, the layers shown above. The position may be changed as appropriate, or one or both of the antireflection layers (the high refractive index layer 25 and the low refractive index layer 26) may be omitted depending on the application. Furthermore, you may provide functional layers, such as a neon cut layer, a color tone adjustment layer, and a transmittance | permeability adjustment layer.

  Any known material may be used for the optical filter for display of the present invention as long as the effects of the present invention are not impaired. An example of the material used below will be described.

[Transparent plastic film]
The material for the transparent plastic film is not particularly limited as long as it is a transparent plastic film (meaning “transparent to visible light”). For example, polyester [eg, polyethylene terephthalate (PET), polybutylene terephthalate], polymethyl methacrylate (PMMA), acrylic resin, polycarbonate (PC), polystyrene, triacetate resin, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polyethylene, Examples thereof include ethylene-vinyl acetate copolymer, polyvinyl butyral, metal ion crosslinked ethylene-methacrylic acid copolymer, polyurethane, cellophane and the like. Among these, polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), etc. are highly resistant to loads during processing (heat, solvent, bending, etc.) and particularly highly transparent. preferable. In particular, PET is preferable because it has excellent processability. You may provide the easily bonding layer for improving the adhesiveness of each functional layer on the surface of a transparent base material. The easy-adhesion layer is, for example, a thermosetting resin such as a copolyester resin and a polyurethane resin, or a metal oxide fine particle such as SiO ₂ , ZrO ₂ , TiO ₂ , or Al ₂ O ₃ , preferably an average. What adjusted the refractive index by mix | blending metal oxide fine particles with a particle size of 1-100 nm is used.

  The thickness of the transparent substrate varies depending on the use of the optical filter and the like, but generally 1 μm to 10 mm, 1 μm to 5 mm, particularly 25 to 250 μm is preferable.

[Conductive layer]
The conductive layer is set so that the surface resistance value of the obtained optical filter is generally 10Ω / □ or less, preferably in the range of 0.001 to 5Ω / □, particularly 0.005 to 5Ω / □. It may be a mesh (lattice) metal conductive layer or a layer obtained by a vapor deposition method (a transparent conductive thin film of metal oxide (ITO or the like)). Further, it may be an alternate laminate of a metal oxide dielectric film such as ITO and a metal layer such as Ag (eg, ITO / silver / ITO / silver / ITO laminate).
The mesh-like metal conductive layer is made of metal fibers and metal-coated organic fibers made of a metal, or a copper foil layer on a transparent substrate is etched into a mesh to provide openings, on a transparent substrate Examples thereof include a conductive ink printed in a mesh shape. Further, dots are formed on the film surface by a material soluble in the solvent, a conductive material layer made of a conductive material insoluble in the solvent is formed on the film surface, and the film surface is brought into contact with the solvent to form dots and A mesh-like metal conductive layer obtained by removing the conductive material layer on the dots may be used. Examples of the metal conductive material include copper, stainless steel, aluminum, nickel, titanium, tungsten, tin, lead, iron, silver, carbon, or alloys thereof, preferably copper, stainless steel, and nickel.

  In order to improve conductivity, a metal plating layer such as copper or copper alloy may be further provided on the mesh-like metal conductive layer. In order to impart antiglare performance, the surface of the conductive layer may be subjected to blackening treatment prevention by oxidation treatment of a metal film, black plating of a chromium alloy or the like, application of black or dark ink, or the like.

[Hard coat layer]
The hard coat layer is a resin composition layer mainly composed of a synthetic resin such as an acrylic resin layer, an epoxy resin layer, a urethane resin layer, or a silicon resin layer. Usually, the thickness of the hard coat layer is 1 to 50 μm from the transparent substrate surface, and preferably 5 to 20 μm in order to obtain high flatness without increasing the layer thickness. Synthetic resins are generally thermosetting resins such as phenol resins, resorcinol resins, urea resins, melamine resins, epoxy resins, acrylic resins, urethane resins, furan resins, silicone resins, or ultraviolet curable resins, as described above. An ultraviolet curable resin is preferable because it can be cured in a short time and is excellent in productivity. When an ultraviolet curable resin is used, it is used as an ultraviolet curable resin composition (consisting of an ultraviolet curable resin, a photopolymerization initiator, etc.).

Further, the hard coat layer may contain a small amount of an ultraviolet absorber, an infrared absorber, an anti-aging agent, a paint processing aid, a colorant and the like. In particular, it is preferable to contain an ultraviolet absorber (for example, a benzotriazole-based ultraviolet absorber or a benzophenone-based ultraviolet absorber), whereby yellowing of the filter can be efficiently prevented. The amount thereof is generally 0.1 to 10% by mass, preferably 0.1 to 5% by mass, based on the resin composition.
[Antireflection layer]
Among the antireflection layers, the high refractive index layer is doped with ITO, ATO, Sb ₂ O ₃ , SbO ₂ , In ₂ O ₃ , SnO ₂ , ZnO, and Al in a polymer (preferably UV curable resin). A layer (cured layer) in which conductive metal oxide fine particles (inorganic compounds) such as ZnO and TiO ₂ are dispersed is preferably used. The metal oxide fine particles preferably have an average particle size of 10 to 10,000 nm, preferably 10 to 50 nm. In particular, ITO (especially having an average particle diameter of 10 to 50 nm) is preferable. The film thickness is generally in the range of 10 to 500 nm, preferably 20 to 200 nm.

  Among the antireflection layers, the low refractive index layer is composed of fine particles such as silica and fluororesin, preferably 10 to 40% by weight (preferably 10 to 30% by weight) of hollow silica in the polymer (preferably UV curable resin). A layer dispersed in (hardened layer) is preferable. The film thickness is generally in the range of 10 to 500 nm, preferably 20 to 200 nm. As the hollow silica, those having an average particle diameter of 10 to 100 nm, preferably 10 to 50 nm, and a specific gravity of 0.5 to 1.0, preferably 0.8 to 0.9 are preferable.

  When composed of the hard coat layer and the above two layers, for example, the total thickness of the hard coat layer is 5 to 20 μm, the thickness of the high refractive index layer is 50 to 150 nm, and the thickness of the low refractive index layer is 50 to 50 μm. It is preferable that it is 150 nm.

  In order to form each layer, for example, as described above, the above-mentioned fine particles are blended with a polymer (preferably an ultraviolet curable resin) as necessary, and the obtained coating liquid is made into a transparent material such as the rectangular transparent plastic film. The coating may be applied to the surface of the substrate, then dried, and then cured by irradiation with ultraviolet rays. In this case, each layer may be applied and cured one by one, or all the layers may be applied and then cured together. In the case of continuous processing, the coating surface may be damaged unless it is cured after coating of each layer. Therefore, it is preferable to coat and cure each layer one by one.

  As a specific method of coating, a coating solution in which an ultraviolet curable resin containing an acrylic monomer or the like is made into a solution with a solvent such as toluene, n-hexane, or methyl ethyl ketone is coated with a gravure coater, and then dried. Next, a method of curing with ultraviolet rays can be mentioned. This wet coating method has the advantage that the film can be uniformly formed at high speed at low cost. After this coating, for example, by irradiating with ultraviolet rays and curing, effects of improving adhesion and increasing the hardness of the film can be obtained.

  In the case of ultraviolet curing, many light sources that emit light in the ultraviolet to visible range can be used as the light source, such as ultra-high pressure, high pressure, low pressure mercury lamp, chemical lamp, xenon lamp, halogen lamp, mercury lamp, carbon arc lamp, incandescent lamp. And laser light. The irradiation time cannot be determined unconditionally depending on the type of lamp and the intensity of the light source, but is about several seconds to several minutes. Moreover, in order to accelerate curing, the laminate may be preheated to 40 to 120 ° C. and irradiated with ultraviolet rays.

[Peeling sheet]
When a release sheet is provided on the pressure-sensitive adhesive layer, the release sheet is preferably a transparent polymer having a glass transition temperature of 50 ° C. or higher. Examples of such a material include polyethylene terephthalate, polycyclohexylene terephthalate, and polyethylene naphthalate. Polyester resins such as nylon 46, modified nylon 6T, nylon MXD6, polyamide resins such as polyphthalamide, ketone resins such as polyphenylene sulfide and polythioether sulfone, and sulfone resins such as polysulfone and polyether sulfone. Other polymers such as polyether nitrile, polyarylate, polyether imide, polyamide imide, polycarbonate, polymethyl methacrylate, triacetyl cellulose, polystyrene, polyvinyl chloride, etc. It is possible to use a resin as a main component. Of these, polycarbonate, polymethyl methacrylate, polyvinyl chloride, polystyrene, and polyethylene terephthalate can be suitably used. The thickness is preferably 10 to 200 μm, particularly preferably 30 to 100 μm.

Hereinafter, the present invention will be described with reference to examples.
[Example 1]

1. Formation of pressure-sensitive adhesive layer (1) Preparation of liquid A The following formulation:
Acrylic adhesive (SK Dyne 2094 (Soken Chemical Co., Ltd.), solid content 25%); 1000 parts by mass Epoxy curing agent (E-AX (Soken Chemical Co., Ltd.), solid content 45%); 5 parts by mass Toluene; Liquid A was prepared by mixing and stirring 100 parts by mass.
(2) Preparation of liquid B Next, using another container, the following formulation:
Cross-linked acrylic resin fine particles (average particle size: 2.6 μm) (Lyosphere RSP-3009 (manufactured by cross-linked PMMA) (manufactured by Toyo Ink)); 0.25 parts by mass Phthalocyanine dye (IR-10A (manufactured by Nippon Shokubai Co., Ltd.)) 0.30 parts by mass Toluene; 100 parts by mass Methyl ethyl ketone; 100 parts by mass Ethyl acetate; 10 parts by mass were mixed and stirred to prepare Liquid B.
(3) Preparation of pressure-sensitive adhesive composition Subsequently, liquid B was added to liquid A and mixed and stirred for 30 minutes to prepare a pressure-sensitive adhesive composition.
(4) Formation of pressure-sensitive adhesive layer The pressure-sensitive adhesive composition was coated on a separator film (film binder 75E-0010 No. 23 (manufactured by Fujimori Kogyo Co., Ltd.)) using an applicator having a gap of 300 μm, and then in an oven. Drying and heat curing were performed at 100 ° C. for 3 minutes to form an adhesive layer. The thickness of the pressure-sensitive adhesive layer was 23 μm.

2. Production of Optical Filter Sample The pressure-sensitive adhesive layer formed on the separator film was bonded to a PET film (Diafoil T680E100-W07 (Mitsubishi Resin Co., Ltd.) thickness: 100 μm) using a hand roller. Next, the separator film was removed from the pressure-sensitive adhesive layer, and a PET film (same as above) was bonded onto the exposed pressure-sensitive adhesive layer using a hand roller. This PET / adhesive layer / PET laminate was cured in an oven at 40 ° C. for 3 days to prepare an optical filter sample.

[Example 2]
An optical filter sample was produced in the same manner as in Example 1 except that the amount of the crosslinked acrylic resin fine particles in Example 1 (2) was 5.0 parts by mass.

[Example 3]
An optical filter sample was produced in the same manner as in Example 1 except that the amount of the crosslinked acrylic resin fine particles in Example 1 (2) was 62.5 parts by mass.

[Example 4]
Except that the crosslinked acrylic resin fine particles of Example 1 (2) were changed to crosslinked acrylic resin fine particles (average particle size; 20 μm) (Techpolymer SSX-120 (produced by crosslinked PMMA) (produced by Sekisui Plastics Co., Ltd.)). An optical filter sample was prepared in the same manner as in Example 1.

[Example 5]
An optical filter sample was produced in the same manner as in Example 4 except that the amount of the crosslinked acrylic resin fine particles in Example 4 was 5.0 parts by mass.

[Example 6]
An optical filter sample was produced in the same manner as in Example 4 except that the amount of the crosslinked acrylic resin fine particles in Example 4 was 62.5 parts by mass.

[Example 7]
The crosslinked acrylic resin fine particles of Example 1 (2) were converted into melamine resin fine particles (average particle size: 0.1 to 0.3 μm) (Eposter (registered trademark) S (manufactured by melamine-formaldehyde condensate) (manufactured by Nippon Shokubai Co., Ltd.). An optical filter sample was produced in the same manner as in Example 1 except that.

[Example 8]
An optical filter sample was produced in the same manner as in Example 7 except that the blending amount of the melamine resin fine particles in Example 7 was 5.0 parts by mass.

[Example 9]
An optical filter sample was produced in the same manner as in Example 7 except that the blending amount of the melamine resin fine particles in Example 7 was 62.5 parts by mass.

[Example 10]
Except that the crosslinked acrylic resin fine particles of Example 1 (2) were silica fine particles (average particle size; 0.08 to 0.14 μm) (made of amorphous silica) (Seahoster KE-P10 (made by Nippon Shokubai Co., Ltd.)) An optical filter sample was produced in the same manner as in Example 1.

[Example 11]
An optical filter sample was prepared in the same manner as in Example 10 except that the amount of silica fine particles in Example 10 was 5.0 parts by mass.

[Example 12]
An optical filter sample was produced in the same manner as in Example 10 except that the amount of silica fine particles in Example 10 was 62.5 parts by mass.

[Comparative Example 1]
An optical filter sample was produced in the same manner as in Example 1 except that the crosslinked acrylic resin fine particles of Example 1 (2) were not blended.

[Evaluation methods]
(1) Transmittance In order to evaluate the deterioration of the phthalocyanine dye, a storage test (temperature of 80 ° C., temperature of 60 ° C., humidity of 90%) was performed, and transmittance at a wavelength of 825 nm after the initial and storage tests was measured.
The measurement was performed based on JIS-R-3106 using a spectrophotometer U-4100 (manufactured by Hitachi High-Tech).

[Evaluation results]
Table 1 shows the evaluation results of Examples 1 to 12 and Comparative Example 1.

  As shown in Table 1, Examples 1 to 12 in which fine particles having an average particle diameter of 0.1 to 20 μm were blended showed a change in transmittance after a storage test as compared with Comparative Example 1 in which fine particles were not blended. It was small. Therefore, it was shown that the deterioration of the phthalocyanine pigment blended in the pressure-sensitive adhesive layer is suppressed according to the present invention.

  In addition, this invention is not limited to the structure and Example of said embodiment, A various deformation | transformation is possible within the range of the summary of invention.

  According to the present invention, it is possible to provide an optical filter for a display having a sufficient near-infrared shielding effect, a simplified configuration, low cost, and high weather resistance, which is effective for a PDP or the like.

11, 21 Transparent base material 12, 22 Adhesive layer 19, 29 Fine particles 20, 30 Optical filter for display 23 Conductive layer 24 Hard coat layer 25 High refractive index layer 26 Low refractive index layer

Claims (7)

  An optical filter for display, comprising an adhesive layer containing a phthalocyanine dye, fine particles having an average particle size of 0.1 to 20 μm, and an adhesive.   The optical filter for display according to claim 1, wherein the fine particles are transparent resin fine particles or silica fine particles.   The transparent resin fine particles are at least one kind of fine particles selected from the group consisting of cross-linked acrylic resin fine particles, cross-linked styrene resin fine particles, cross-linked (meth) acrylate-styrene copolymer fine particles, and melamine resin fine particles. The optical filter for display as described.   The optical filter for display according to any one of claims 1 to 3, wherein the content of the fine particles is 0.1 to 20% by mass based on the nonvolatile content of the pressure-sensitive adhesive layer.   The optical filter for display according to any one of claims 1 to 4, wherein the phthalocyanine dye has a maximum absorption wavelength at 750 to 950 nm.   The optical filter for display according to any one of claims 1 to 5, wherein the pressure-sensitive adhesive is an acrylic resin-based pressure-sensitive adhesive.   It is an object for plasma display panels, The optical filter for displays of any one of Claims 1-6.

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