JP2009244291A - Optical filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical filter for a PDP such that the display screen does not become white and display is viewed with high contrast. <P>SOLUTION: The optical filter is constituted by stacking at least two or more kinds of optical function layers with an adhesive layer interposed, wherein the optical function layers each comprises a base made of a polyester-based resin, or the base and a coating provided on its surface, at least one of the base, coating, and adhesive layer contains a material developing an optical function, and the adhesive layer is made of a polyester-based resin. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical filter, and more particularly, for a plasma display panel having one or more functions of antireflection, antiglare, ultraviolet absorption, near infrared absorption, neon light absorption, electromagnetic wave shielding, and color tone correction. It relates to an optical filter.

  In a plasma display panel (hereinafter sometimes abbreviated as PDP), ultraviolet rays hit phosphors in a line spectrum in an ultraviolet region or a near infrared region generated when xenon or neon filled in the PDP is excited by discharge. As a result, visible light is generated and image display is performed.

  As described above, near infrared light having a wavelength of 800 to 1000 nm is emitted from the PDP in addition to the visible region, which may cause malfunction of an infrared remote controller such as a display device or a video device.

  In addition, since PDP generates electromagnetic waves with a frequency of 30 to 130 MHz, it is said that it may affect surrounding computers and computer-utilized devices, and may adversely affect human bodies and animals. Therefore, it is desired that electromagnetic waves generated from the PDP are not leaked to the outside as much as possible.

  Furthermore, since the orange light emission is emitted from the neon filled in the PDP, the color tone of the display image may be out of order.

  In addition, when external light (for example, a fluorescent lamp) is inserted into the front surface of the PDP, the contrast of the image may be reduced by reflected light from the front surface, and the image may be difficult to see.

  In order to solve the above problems, in PDP, various functions such as an electromagnetic wave shielding layer, a near infrared absorption layer, an antireflection layer, a color tone correction layer, and a neon light absorption layer are provided on a transparent substrate such as glass and plastic. By placing the applied optical filter on the front surface of the PDP, electromagnetic wave and near-infrared leakage prevention, external light reflection prevention, color tone correction, and the like are performed (for example, Japanese Patent Application Laid-Open No. 2001-210988: Patent Documents). 1).

  Such an optical filter for plasma display is, for example, a transparent plastic substrate provided with a conductor mesh layer, a transparent plastic substrate containing a near infrared absorber, a plastic substrate provided with an antireflection film on the surface, etc. Each of these is laminated and integrated with each other via an adhesive layer to achieve a reduction in thickness and weight (for example, Japanese Patent Application Laid-Open No. 11-122024: Patent Document 2).

As the base material used for the optical filter, a polyester-based resin is usually preferably used from the viewpoints of light transmittance, strength, economy, and the like. Moreover, a near infrared absorber, a neon light absorber, etc. may be added also to an adhesive layer, In that case, it consists of (meth) acrylic-type resin so that an absorber may not deteriorate also in a high temperature environment. An adhesive is usually used (for example, JP-A-2003-82302).
JP 2001-210988 A Japanese Patent Laid-Open No. 11-12604 JP 2003-82302 A

  However, when the base materials made of polyester resin are laminated via the pressure-sensitive adhesive layer made of (meth) acrylic resin, the refractive index of the polyester resin is about 1.65, and (meth) acrylic resin Since the refractive index is approximately 1.49, external light is reflected at the interface between the layers, and the display screen may be whitened or the contrast of the image may be reduced.

  Therefore, an object of the present invention is to provide an optical filter for PDP in which the display screen of the PDP is not whitened and the display can be viewed with high contrast.

  Another object of the present invention is to provide a plasma display panel including the optical filter as described above.

  In order to solve the above-described problems, the adhesive layer for adhering each functional layer constituting the optical filter has a function layer and an adhesive layer for reducing light reflection at each layer interface. Focusing on the difference in refractive index of the pressure-sensitive adhesive layer, the inventors have intensively studied the material of the pressure-sensitive adhesive layer. As a result, the present invention has been completed.

The optical filter according to the present invention is an optical filter in which at least two types of optical functional layers are laminated via an adhesive layer,
The optical functional layer comprises a base material made of a polyester-based resin, or a base material and a coating provided on the surface thereof,
At least one of the base material, the coating film, or the pressure-sensitive adhesive layer contains a material that exhibits an optical function,
The pressure-sensitive adhesive layer is made of a polyester resin.

  In a preferred aspect of the present invention, the optical function is at least one selected from the group consisting of antireflection, antiglare, ultraviolet absorption, near infrared absorption, neon light absorption, electromagnetic wave shielding, and color correction. .

  In a preferred embodiment of the present invention, the refractive index difference between the optical functional layer and the pressure-sensitive adhesive layer is 0.1 or less.

  Moreover, in the aspect of this invention, it is preferable that a near-infrared absorber is contained in the said adhesive layer.

  Moreover, in the aspect of this invention, it is preferable that the said near-infrared absorber comprises at least 1 or more types in four types of phthalocyanine compounds (A)-(D) mentioned later.

  Furthermore, in the embodiment of the present invention, the optical filter preferably has a visible light transmittance of at least 30% or more.

  As a preferred embodiment of the present invention, the optical filter is used for a plasma display panel.

  In the present invention, a plasma display panel provided with the above optical filter is also provided.

  In the present invention, since at least two or more types of optical functional layers constituting the optical filter and the pressure-sensitive adhesive layer that bonds the optical functional layers are made of the same polyester-based resin, the refractive index of each layer The difference is small, so even if external light is incident on the optical filter, the reflection of incident light at the interface is reduced, which greatly improves the whitening problem of the PDP display screen and improves the image contrast. To do.

  Moreover, in this invention, durability (color difference) of a near-infrared absorber can be improved by adding the above-mentioned specific phthalocyanine compound to a polyester-type adhesive as a near-infrared absorber.

  The optical filter according to the present invention has a structure in which at least two kinds of optical functional layers are laminated via an adhesive layer, and the optical functional layer is a substrate made of a polyester resin, or the substrate and the substrate. A coating provided on the surface, and at least one of the substrate, the coating, or the pressure-sensitive adhesive layer contains a material that exhibits an optical function, and the pressure-sensitive adhesive layer is made of a polyester resin. It will be. Hereinafter, the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view showing an embodiment of an optical filter according to the present invention.

  The optical filter 1 according to the present invention has a structure in which an optical functional layer 2 composed of a polyester base material and another optical functional layer 2 ′ composed of a polyester base material are laminated via an adhesive layer 3. The pressure-sensitive adhesive layer 3 is made of a polyester resin. As described above, since each layer constituting the optical filter is made of a polyester-based resin, reflection at the interfaces A and B when light enters the optical filter is greatly reduced. As a result, when applied to a display element such as a plasma display panel, whitening of the display screen is reduced and image contrast is improved.

  FIG. 2 is a sectional view of an optical filter showing another embodiment of the present invention. In the present invention, an optical functional layer 2 ′ provided with an antireflection film or an antiglare layer as a coating 6 on the substrate 5 can be laminated with the pressure-sensitive adhesive layer 3. Moreover, it is good also as a base material which provided the antireflection function and / or the glare-proof function, without forming a film (not shown). As the optical functional layer, not only an antireflection film and an antiglare layer, but also at least one layer selected from an ultraviolet absorption layer, a near infrared absorption layer, a neon light absorption layer, an electromagnetic wave shielding layer, and a color tone correction layer is used. Can be used together.

  Since the optical filter is usually disposed on the front surface of the plasma display panel, a protective film (not shown) such as a hard coat layer may be provided on the front surface in order to protect the plasma display panel and the optical filter. Moreover, you may add a near-infrared absorber, a neon cut pigment | dye, a color correction pigment | dye, and another additive in an adhesive layer.

  In the present invention, an electromagnetic wave shielding layer may be provided as the optical functional layer of the optical filter. As shown in FIG. 3, the pressure-sensitive adhesive layer 3 can be provided by being bonded to the electromagnetic wave shielding layer 8.

  In addition, as shown in FIG. 3, various functional additives 5 such as an ultraviolet absorber, a neon light collecting agent, and a color toning agent are added to the base 5 of the optical functional layer 2 ′, so that various types of optical functional layers can be added. It is also possible to give this function. In addition to adding these functional additives into the base material, by forming a coating film (film) on the surface of the base material using a coating liquid obtained by adding the additive to the polyester resin composition. Needless to say, it can be an optical functional layer. Moreover, when forming a film, you may provide in the base-material surface. In the present invention, it is basically necessary that at least one or more positional relationships exist such that the polyester base material and the pressure-sensitive adhesive layer made of the polyester resin are in direct contact. However, when the refractive index of the third layer such as the optical functional layer is close to the refractive index of the polyester resin (that is, the refractive index difference is about 0.14, preferably 0.1 or less), the third layer is You may provide in the interface side of the adhesive layer which consists of a polyester base material and a polyester-type resin.

  Hereinafter, each layer constituting the optical filter will be described.

<Base material>
The substrate used for the optical filter according to the present invention is made of a polyester resin. The polyester resin is used for a conventional substrate for an optical film from the viewpoint of transparency, heat resistance, handleability, and low cost, and has a refractive index of about 1,65.

  Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyglycolic acid, poly (L-lactic acid), poly (3-hydroxybutyrate), and poly (3-hydroxybutyrate / hydroxy). Valerate), poly (ε-caprolactone), polyethylene succinate, polybutylene succinate, polybutylene succinate adipate, polybutylene succinate / lactic acid copolymer, polybutylene succinate / carbonate copolymer, polybutylene succinate / Terephthalate copolymer, polybutylene adipate / terephthalate copolymer, polytetramethylene adipate / terephthalate copolymer, polybutylene succinate / adipate / terephthalate, etc. Is polyethylene terephthalate having excellent heat resistance and toughness Among these, preferred.

  The substrate made of a polyester resin is not necessarily colorless and transparent, and may be a colored transparent substrate as long as the light transmittance is not extremely lowered.

  Moreover, as the polyester resin used as the substrate, usually, a stretched sheet or film is preferably used from the viewpoint of mechanical strength and the like, but an unstretched sheet or film can also be used. From the viewpoint of mechanical strength, it is preferable to use a uniaxially or biaxially stretched sheet or film.

  The thickness of the substrate is usually preferably about 10 to 300 μm from the viewpoint of workability.

  In the present invention, as shown in FIG. 3, an optical functional layer can be formed by adding an ultraviolet absorber, a near infrared absorber, or the like as described later to the base material made of the polyester resin.

  Further, the base material does not necessarily have to be a single layer, and for example, only a surface layer (coating) as shown in FIG. 2 may be an optical functional layer composed of a multilayer base material containing an ultraviolet absorber.

  In addition to the optical functional additive, additives such as a filler, a plasticizer, and an antistatic agent can be added to the substrate as desired.

  Further, the substrate is appropriately subjected to known easy adhesion treatment such as corona discharge treatment, plasma treatment, ozone treatment, flame treatment, primer treatment, pre-heat treatment, dust removal treatment, vapor deposition treatment, alkali treatment, etc. on the surface. be able to.

<Adhesive layer>
The pressure-sensitive adhesive layer constituting the optical filter according to the present invention is a layer for bonding the optical functional layers together, and uses a pressure-sensitive adhesive made of a polyester-based resin in the same manner as the base material of the optical functional layer.

  The pressure-sensitive adhesives used in conventional optical filters for plasma displays were preferably acrylic acid ester-based pressure-sensitive adhesives, urethane acrylate-based pressure-sensitive adhesives, epoxy acrylate-based pressure-sensitive adhesives, etc., but these acrylic pressure-sensitive adhesives Since the refractive index is about 1.49, when a polyester resin film having a refractive index of about 1.65 is used as a base material, a refractive index difference is generated at the interface.

  In the present invention, by using a polyester-based pressure-sensitive adhesive having a refractive index equivalent to that of the base material, the difference in refractive index between the base material (optical functional layer) and the pressure-sensitive adhesive layer is reduced, thereby reflecting at the interface. It suppresses.

  As such a polyester-based pressure-sensitive adhesive, one having a copolyester obtained by polycondensation of an acid component and a polyol component as its main component is used. The polycondensation reaction is performed by a general polyesterification reaction such as a direct esterification method or a transesterification method.

  Acid components include terephthalic acid, isophthalic acid, phthalic anhydride, α-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid or esters thereof, pimelic acid, suberic acid, azelaic acid, sebacin Aliphatic dicarboxylic acids such as acid, undecylenic acid, dodecanedicarboxylic acid or esters thereof, and alicyclic dicarboxylic acids such as 1,4-cyclohexahydrophthalic anhydride are used.

  Examples of polyol components that react with these acid components include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, and 1,5-pentane. Diol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, neopentyl glycol, 3-methylpentanediol, 2,2,3-trimethylpentanediol, diethylene glycol, triethylene glycol, di Aliphatic glycols such as propylene glycol, alicyclic glycols such as 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol, and aromatic glycols such as bisphenol A are used.

  Since the polyester-based pressure-sensitive adhesive has the chemical composition as described above, the refractive index is approximately 1.55 to 1.7, which is substantially the same as the polyester-based resin used as the base material.

  In the combination of the base material and the pressure-sensitive adhesive described above, it is preferable to select both appropriately so that the refractive index difference between them is 0.1 or less.

  The polyester-based pressure-sensitive adhesive used in the present invention is generally used as an organic solvent solution having a solid content concentration of about 10 to 60% by weight. Examples of the organic solvent include alcohols such as methanol and ethanol, fatty acid esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, and aromatic hydrocarbons such as toluene and xylene. Aliphatic or alicyclic hydrocarbons are also used. It is also used as an aqueous solution or an aqueous organic solvent solution.

  In addition, a commercially available polyester-based pressure-sensitive adhesive prepared with a water (sex) solution or an organic solvent solution, such as Polyester (manufactured by Nippon Synthetic Chemical), etc. can be diluted to an appropriate concentration and used.

  The pressure-sensitive adhesive layer is obtained by applying the above-mentioned polyester-based pressure-sensitive adhesive to the optical functional layer by a commonly used coating method such as transfer printing, knife coater, roll coater, comma coater, gravure coater, etc. It can be formed by heating and drying by the above.

  In addition, as shown in FIG. 2, before forming the pressure-sensitive adhesive layer, a pressure-sensitive adhesive having an optical function is obtained by applying and drying a polyester-based pressure-sensitive adhesive to which an optical functional agent as described later is added. It can be used as an agent layer.

  Moreover, you may use the adhesive sheet which coated the polyester-type adhesive as an adhesive layer.

<Antireflection layer and antiglare layer>
The antireflection layer is generally a layer in which a high refractive index layer and a low refractive index layer are laminated in order, but there are also layers having other laminated structures. High refractive index layer is, for example, a transparent resin film on which a thin film of ZnO or TiO ₂ material, or particles of these materials are dispersed. Further, the low refractive index layer, a thin film made of SiO ₂ or SiO ₂ gel film or a fluorine-containing, or a transparent resin film of fluorine and silicon-containing. By laminating the antireflection layer, it is possible to reduce reflection of unnecessary light such as external light on the laminated side, and to increase the contrast of the image or video of the display to be applied.

  The antireflection film can be formed by alternately laminating a low refractive index component and a high refractive component on a base material by a dry method such as vapor deposition or sputtering, or a wet method such as coating. Moreover, you may provide on the base material what formed the antireflection film in the sheet | seat or the film.

  Among the optical functional layers, the antiglare layer is for preventing scintillation occurring at a specific position and direction of the display when it is disposed on the front surface of the display due to the light spreading property of the layer. The anti-glare layer has fine irregularities that irregularly reflect external light by adding inorganic fillers such as silica or dispersing beads such as polystyrene resin or acrylic resin with a diameter of several μm in the substrate surface. Is formed. In addition to directly adding a filler or the like to the substrate, a film formed by adding an inorganic filler or the like to the transparent resin binder may be provided on the substrate. In this case, as the transparent resin binder to be used, an electron radiation curable resin or the like can be preferably used, but a polyester resin having no difference in refractive index from the substrate should be selected.

<Electromagnetic wave shielding layer>
The electromagnetic wave shielding layer shields electromagnetic waves generated from an electrical or electronic device, particularly a plasma display. As the electromagnetic wave shielding layer, a metal mesh layer and a transparent conductive thin film layer are used, and a metal mesh having high electromagnetic wave shielding properties is preferable. Since the metal mesh layer is formed by laminating a metal foil on a transparent base material and forming a mesh shape by etching, an adhesive layer may be interposed between the base material and the metal mesh as shown in FIG. It is normal.

  The metal mesh layer is not particularly limited as long as it has electromagnetic wave shielding ability. For example, copper, iron, nickel, chromium, aluminum, gold, silver, stainless steel, tungsten, chromium, Titanium or the like can be used, among which copper is preferable, and examples of the copper foil include a rolled copper foil and an electrolytic copper foil, and an electrolytic copper foil is particularly preferable. By selecting the electrolytic copper foil, the thickness can be improved to 10 μm or less, and the adhesion with chromium oxide or the like can be improved when blackened. Because it can.

  Here, in the present invention, it is preferable that one side or both sides of the metal mesh is blackened. The blackening treatment is a treatment for blackening the surface of the metal mesh with chromium oxide or the like, and when applied to the near-infrared absorbing film or a laminate thereof, the oxidation-treated surface becomes a surface on the observer side. Are arranged as follows. Since the external light on the surface of the metal mesh layer is absorbed by chromium oxide or the like formed on the surface of the metal mesh layer by this blackening treatment, it is possible to prevent light from being scattered on the surface of the metal mesh layer. .

  The aperture ratio of the metal mesh layer is preferably as low as possible from the viewpoint of electromagnetic wave shielding ability. However, since the light transmittance decreases as the aperture ratio decreases, the aperture ratio is preferably 50% or more.

  Moreover, since the opening part and the non-opening part have the unevenness | corrugation in a metal mesh layer, the planarization layer in which transparent resin was formed in the thickness more than the thickness of a metal mesh layer is laminated | stacked on the metal mesh layer. Also good.

<Near infrared absorbing layer>
As a near-infrared absorber used in the present invention, a conventionally known one can be used and is not particularly limited. Examples of near infrared absorbers include metal oxides such as iron oxide, cerium oxide, tin oxide, and antimony oxide, indium-tin oxide, tungsten hexachloride, tin chloride, cupric sulfide, chromium-cobalt complex, thiol- Infrared absorbers such as nickel complexes, aluminum compounds, dimonium compounds and phthalocyanine compounds can be suitably used.

  In the present invention, as described above, a material that exhibits an optical function may be contained in the pressure-sensitive adhesive layer. However, when a near-infrared absorber is contained in the pressure-sensitive adhesive layer, the following description will be given. It is more preferable to use the phthalocyanine compound. The durability (color difference) is further improved by combining the polyester-based pressure-sensitive adhesive with the following specific phthalocyanine compound.

式中、Ａ^１〜Ａ^１６は、各々独立に、水素原子、ハロゲン原子、水酸基、アミノ基、ヒドロキシスルホニル基、アミノスルホニル基、あるいは窒素原子、硫黄原子、酸素原子またはハロゲン原子を含んでも良い炭素数１〜２０の置換基を表し、かつ、隣り合う２個の置換基が連結基を介して繋がっていてもよい。また、Ｍ^１は、酸化バナジウムまたは銅を表す。 The phthalocyanine compound suitably used in combination with the polyester-based pressure-sensitive adhesive contains at least one of the following four types of phthalocyanine compounds (A) to (D).
Phthalocyanine compound (A):
A compound represented by the following formula [I] (provided that at least four of A ^{1 to} A ¹⁶ are substituents via a sulfur atom, and at least three have a chlorine atom. M ¹ is oxidized) Vanadium.)
Phthalocyanine compound (B):
A compound represented by the following formula [I] (provided that at least four of A ^{1 to} A ¹⁶ are substituents via a sulfur atom and substantially have no chlorine atom. M ¹ is Vanadium oxide.)
Phthalocyanine compound (C):
A compound represented by the following formula [I] (provided that at least four of A ^{1 to} A ¹⁶ are a substituent via a nitrogen atom and substantially free of a substituent via a sulfur atom). M ¹ is vanadium oxide.)
Phthalocyanine compound (D):
A compound represented by the following formula [I] (provided that at least four of A ^{1 to} A ¹⁶ are a substituent via a nitrogen atom and are substantially free of a substituent via a sulfur atom. ¹ is copper.)

In the formula, each of A ^{1 to} A ¹⁶ independently represents a hydrogen atom, a halogen atom, a hydroxyl group, an amino group, a hydroxysulfonyl group, an aminosulfonyl group, or a carbon atom that may contain a nitrogen atom, a sulfur atom, an oxygen atom, or a halogen atom. The substituents represented by Formulas 1 to 20 may be represented, and two adjacent substituents may be connected via a linking group. M ¹ represents vanadium oxide or copper.

  Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, a fluorine atom and a chlorine atom are particularly preferable.

Examples of the substituent having 1 to 20 carbon atoms that may contain a nitrogen atom, a sulfur atom, an oxygen atom, or a halogen atom include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, and an iso-butyl group. Linear, branched or cyclic alkyl such as a group, sec-butyl group, t-butyl group, n-pentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, etc. Group, methoxymethyl group, phenoxymethyl group, diethylaminomethyl group, phenylthiomethyl group, benzyl group, p-chlorobenzyl group, p-methoxybenzyl group, etc. -Aryl groups such as methoxyphenyl group, pt-butylphenyl group, p-chlorophenyl group, methoxy group, ethoxy group, n-propyl group Si group, iso-propyloxy group, n-butyloxy group, iso-butyloxy group, sec-butyloxy group, t-butyloxy group, n-pentyloxy group, n-hexyloxy group, cyclohexyloxy group, n-heptyloxy group N-octyloxy group, alkoxy group such as 2-ethylhexyloxy group, alkoxymethoxy group such as methoxyethoxy group and phenoxyethoxy group, hydroxyalkoxy group such as hydroxyethoxy group, benzyloxy group, p-chlorobenzyloxy group, aryloxy such as aralkyloxy group such as p-methoxybenzyloxy group, phenoxy group, p-methoxyphenoxy group, pt-butylphenoxy group, p-chlorophenoxy group, o-aminophenoxy group, p-diethylaminophenoxy group Group, acetyl Oxy group, ethylcarbonyloxy group, n-propylcarbonyloxy group, iso-propylcarbonyloxy group, n-butylcarbonyloxy group, iso-butylcarbonyloxy group, sec-butylcarbonyloxy group, t-butylcarbonyloxy group, n-pentylcarbonyloxy group, n-hexylcarbonyloxy group, cyclohexylcarbonyloxy group, n-heptylcarbonyloxy group, 3-heptylcarbonyloxy group, alkylcarbonyloxy group such as n-octylcarbonyloxy group, benzoyloxy group, p-chlorobenzoyloxy group, p-methoxybenzoyloxy group, p-ethoxybenzoyloxy group, p-t-butylbenzoyloxy group, p-trifluoromethylbenzoyloxy group, m-trifluoromethyl Arylbenzoyl group such as rubenzoyloxy group, o-aminobenzoyloxy group, p-diethylaminobenzoyloxy group, methylthio group, ethylthio group, n-propylthio group, iso-propylthio group, n-butylthio group, iso-butylthio group , Sec-butylthio group, t-butylthio group, n-pentylthio group, n-hexylthio group, cyclohexylthio group, n-heptylthio group, n-octylthio group, 2-ethylhexylthio group and other alkylthio groups, benzylthio group, p- Aralkylthio groups such as chlorobenzylthio group and p-methoxybenzylthio group, phenylthio group, p-methoxyphenylthio group, pt-butylphenylthio group, p-chlorophenylthio group, o-aminophenylthio group, o -(N-octylamino) pheny Arylthio groups such as thio group, o- (benzylamino) phenylthio group, o- (methylamino) phenylthio group, p-diethylaminophenylthio group, naphthylthio group, methylamino group, ethylamino group, n-propylamino group, n -Butylamino group, sec-butylamino group, n-pentylamino group, n-hexylamino group, n-heptylamino group, n-octylamino group, 2-ethylhexylamino group, dimethylamino group, diethylamino group, di- n-propylamino group, di-n-butylamino group, di-sec-butylamino group, di-n-pentylamino group, di-n-hexylamino group, di-n-heptylamino group, di-n- Alkylamino groups such as octylamino group, phenylamino group, p-methylphenylamino group, pt-butyl group Arylamino groups such as nylamino group, diphenylamino group, di-p-methylphenylamino group, di-pt-butylphenylamino group, acetylamino group, ethylcarbonylamino group, n-propylcarbonylamino group, iso- Propylcarbonylamino group, n-butylcarbonylamino group, iso-butylcarbonylamino group, sec-butylcarbonylamino group, t-butylcarbonylamino group, n-pentylcarbonylamino group, n-hexylcarbonylamino group, cyclohexylcarbonylamino Group, n-heptylcarbonylamino group, 3-heptylcarbonylamino group, alkylcarbonylamino group such as n-octylcarbonylamino group, benzoylamino group, p-chlorobenzoylamino group, p-methoxybenzoylamino group Arylcarbonylamino groups such as p-methoxybenzoylamino group, p-t-butylbenzoylamino group, p-chlorobenzoylamino group, p-trifluoromethylbenzoylamino group, m-trifluoromethylbenzoylamino group,
Hydroxycarbonyl group, methoxycarbonyl group, ethoxycarbonyl group, n-propyloxycarbonyl group, iso-propyloxycarbonyl group, n-butyloxycarbonyl group, iso-butyloxycarbonyl group, sec-butyloxycarbonyl group, t-butyl Alkoxycarbonyl groups such as oxycarbonyl group, n-pentyloxycarbonyl group, n-hexyloxycarbonyl group, cyclohexyloxycarbonyl group, n-heptyloxycarbonyl group, n-octyloxycarbonyl group, 2-ethylhexyloxycarbonyl group, methoxy Alkoxyalkoxycarbonyl groups such as ethoxycarbonyl group, phenoxyethoxycarbonyl group, hydroxyethoxycarbonyl group, benzyloxycarbonyl group, phenoxycarboni Group, p-methoxyphenoxycarbonyl group, p-t-butylphenoxycarbonyl group, p-chlorophenoxycarbonyl group, o-aminophenoxycarbonyl group, p-diethylaminophenoxycarbonyl group and other aryloxycarbonyl groups, aminocarbonyl group, methyl Aminocarbonyl group, ethylaminocarbonyl group, n-propylaminocarbonyl group, n-butylaminocarbonyl group, sec-butylaminocarbonyl group, n-pentylaminocarbonyl group, n-hexylaminocarbonyl group, n-heptylaminocarbonyl group N-octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dimethylaminocarbonyl group, diethylaminocarbonyl group, di-n-propylaminocarbonyl group, di-n-butylamino Alkyl such as rubonyl group, di-sec-butylaminocarbonyl group, di-n-pentylaminocarbonyl group, di-n-hexylaminocarbonyl group, di-n-heptylaminocarbonyl group, di-n-octylaminocarbonyl group Aminocarbonyl group, phenylaminocarbonyl group, p-methylphenylaminocarbonyl group, pt-butylphenylaminocarbonyl group, diphenylaminocarbonyl group, di-p-methylphenylaminocarbonyl group, di-pt-butylphenyl Arylcarbonyl group such as aminocarbonyl group, methylaminosulfonyl group, ethylaminosulfonyl group, n-propylaminosulfonyl group, n-butylaminosulfonyl group, sec-butylaminosulfonyl group, n-pentylaminosulfonyl group, n- F Xylaminosulfonyl group, n-heptylaminosulfonyl group, n-octylaminosulfonyl group, 2-ethylhexylaminosulfonyl group, dimethylaminosulfonyl group, diethylaminosulfonyl group, di-n-propylaminosulfonyl group, di-n-butylamino Alkyl such as sulfonyl group, di-sec-butylaminosulfonyl group, di-n-pentylaminosulfonyl group, di-n-hexylaminosulfonyl group, di-n-heptylaminosulfonyl group, di-n-octylaminosulfonyl group Aminosulfonyl group, phenylaminosulfonyl group, p-methylphenylaminosulfonyl group, pt-butylphenylaminosulfonyl group, diphenylaminosulfonyl group, di-p-methylphenylaminosulfonyl group, di-pt-butylphenyl And aryl aminosulfonyl group such sulfonyl aminosulfonyl group.

Examples of the substituent that two adjacent substituents may be linked via a linking group include a substituent that forms a 5-membered ring or a 6-membered ring via a heteroatom represented by the following formula or the like. Can be mentioned.

The “substituent through sulfur atom” in the phthalocyanine compounds (A) and (B), or the “substituent through nitrogen atom” in the phthalocyanine compounds (C) and (D) includes an amino group, an aminosulfonyl group, Examples thereof include an alkylthio group, an arylthio group, an alkylamino group, an arylamino group, an alkylcarbonylamino group, and an arylcarbonylamino group. The absorption wavelength of phthalocyanine is usually about 600 to 750 nm. However, when a substituent via a sulfur atom or a nitrogen atom is introduced, the absorption becomes longer, and the absorption reaches 800 nm or more. To that end, at least four of A ^{1 to} A ¹⁶ are a substituent via a sulfur atom and / or a substituent via a nitrogen atom, more preferably eight or more are a substituent via a sulfur atom and / or It is a substituent through a nitrogen atom.

  In this invention, when a polyester-type adhesive layer contains a near-infrared absorber, it is preferable as a phthalocyanine compound that at least 1 or more types of said 4 types of phthalocyanine compounds (A)-(D) are included. The method for selecting one or more phthalocyanine compounds, the combination of phthalocyanine compounds, the mixing ratio of each phthalocyanine compound, and the like are arbitrary. In addition, this invention does not exclude using together 2 or more types of compounds classified as the same kind of phthalocyanine compound. That is, for example, the case where two or more phthalocyanine compounds (A) belonging to the group of compounds classified as the phthalocyanine compound (A) are used in combination is not excluded. The same applies to the phthalocyanine compounds (B) to (D).

In the present invention, considering the specific contents of the substituents A ^{1 to} A ^{16 in} the phthalocyanine compound, the specific identification of the phthalocyanine compound thereby, particularly the infrared absorption characteristics, etc., combinations of phthalocyanine compounds, The mixing ratio and the total blending amount of all phthalocyanine compounds can be determined.

  As the above-mentioned four kinds of phthalocyanine compounds, commercially available ones can be used, for example, IR-12, IR-14, IR-17, IR-10, IR-910 (all manufactured by Nippon Shokubai Co., Ltd.) and the like. Can be mentioned.

  Moreover, in this invention, conventionally well-known near-infrared absorbers, such as a diimonium dye, can also be used together as a near-infrared absorber other than the above-mentioned phthalocyanine compound.

  In the present invention, the optical characteristics of the optical filter (for example, absorption wavelength region, light transmittance, etc.) can be changed by appropriately changing the specific types and combinations of the near-infrared absorber, the blending amount thereof, or the blending ratio thereof. ) Can be arbitrarily controlled, and the most preferable optical filter according to the specific use, purpose, etc. of the near infrared absorption function can be provided.

<Ultraviolet absorbing layer>
An optical functional material made of an organic compound, particularly a near infrared absorber such as a metal complex, may be decomposed by ultraviolet rays or heat to lower the durability of the optical functional layer. In the present invention, in order to improve the durability, an ultraviolet absorbing layer can be provided to improve the durability of a near infrared absorber or the like.

  A conventionally well-known thing can be used as a ultraviolet absorber, and it does not restrict | limit in particular. For example, as UV absorbers, stilbene compounds, benzimidazole compounds, benzoxazole compounds, benzophenone compounds, benzotriazole compounds, benzoate compounds, benzoxazinone compounds, triazine compounds, hydroxyphenyl triazine compounds, etc. Can be preferably used. Moreover, you may use light stabilizers, such as a hindered amine compound.

  The ultraviolet absorbing layer may be formed by adding an ultraviolet absorber to the substrate, as in the case of other optical functional layers. In addition, a transparent resin binder with an ultraviolet absorber added may be formed on the substrate. It may be coated and dried to form a coating.

<Neon light absorption layer and color tone correction layer>
The neon light shielding layer that can be added to the near-infrared absorbing layer itself or to the laminate constituting the optical filter is for cutting unnecessary light emission around 595 nm mainly emitted by excitation of neon gas in the PDP. What is necessary is just to carry out similarly to formation of the above-mentioned near-infrared absorption layer using the neon light-shielding pigment | dye and binder resin which have absorption maximum near this wavelength, and other additives etc. which are added as needed.

  As the neon light shielding dye, cyanine-based, oxonol-based, methine-based, subphthalocyanine-based, porphyrin-based, or tetraazaporphyrin-based compounds can be preferably used, and porphyrin-based compounds are particularly preferable from the viewpoint of durability.

  Moreover, you may add a well-known light stabilizer, antioxidant, etc. in a neon light absorption layer and / or a color tone correction layer.

<Plasma display panel>
The plasma display panel according to the present invention is characterized in that the optical filter 1 is disposed on the front surface side (observation surface side) of the display panel 10.

  When the optical filter according to the present invention is used for PDP, it is installed on the front surface of the display panel 10 with an adhesive 9 as shown in FIG. For this reason, when the visible light transmittance is low, the sharpness of the image is lowered. Therefore, the higher the visible light transmittance of the filter, the better. At least 30% or more, preferably 35% or more is necessary.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, these examples do not limit the scope of the present invention.

Example 1
Two polyethylene terephthalate resin films (PETA4100, manufactured by Toyobo Co., Ltd.) having a thickness of 100 μm were prepared. Next, on the surface of one of the films, a polyester-based pressure-sensitive adhesive (Polyester XI-1001, manufactured by Nippon Synthetic Chemical) and a curing agent (L-55E, manufactured by Nippon Synthetic Chemical) are set to a weight ratio of 100: 1. The pressure-sensitive adhesive mixed in was coated with an applicator so that the film thickness was 25 μm and dried in an oven at 70 ° C. for 2 minutes. Subsequently, after drying, the other polyethylene terephthalate resin film was laminated on the film to produce an optical filter 1 having a layer configuration of PET film layer / adhesive layer / PET film layer.

  The obtained optical filter 1 was evaluated for reflection performance as follows.

  The obtained optical filter was placed on a black acrylic resin plate, and an artificial solar light was irradiated to the optical filter at an illuminance of 2500 lux from an oblique upper angle of 45 degrees with respect to the normal line of the acrylic resin plate, and reflected light. Was visually observed from an angle of 30 degrees with respect to the normal.

Based on the optical filter 6 of Comparative Example 3 to be described later, a case where the gloss of the reflected light by visual observation is less than that of the optical filter 6 is indicated by “◯”, and a case where the gloss is equal to or higher than that of the optical filter 6 is indicated by “X”.
The evaluation results were as shown in Table 1 below.

Further, the durability (color difference) of the obtained optical filter was also evaluated. For the color difference, chromaticity (x, y) was measured using a spectrophotometer (UV-3100PC, manufactured by Shimadzu Corporation), and durability was evaluated according to the following criteria.
○: Δx, y <0.01
Δ: 0.01 ≦ Δx, y <0.02
×: Δx, y ≧ 0.02
The evaluation results were as shown in Table 1 below.

Example 2
An optical film 2 having near-infrared absorbing ability was produced in the same manner as in Example 1 except that the polyester-based pressure-sensitive adhesive used in Example 1 was added with a phthalocyanine dye and stirred. Three types of IR12, IR14, and IR910 (all manufactured by Nippon Shokubai Co., Ltd.) were used as phthalocyanine dyes. Moreover, as addition amount to an adhesive, IR12 was 0.27 weight%, IR14 was 0.5 weight%, and IR910 was 0.67 weight% with respect to 100 weight% of adhesive solid content.

The optical filter 2 obtained as described above was evaluated for reflection performance and durability in the same manner as in Example 1.
The evaluation results were as shown in Table 1 below.

Example 3
Instead of the near-infrared absorber used in Example 2, 0.85% by weight of IR12, 0.45% by weight of IR14, and 1.5% by weight of IRG068 (manufactured by Nippon Kayaku) which is a diimonium-based dye are used. An optical filter 3 having near-infrared absorbing ability was produced in the same manner as in Example 2 except that.

The optical filter 3 obtained as described above was evaluated for reflection performance and durability in the same manner as in Example 1.
The evaluation results were as shown in Table 1 below.

Comparative Example 1
Example 2 except that an acrylic adhesive (SK2094, manufactured by Soken Chemical) was used instead of the polyester adhesive used in Example 2, and an epoxy curing agent (E-5XM, manufactured by Soken Chemical) was used. In the same manner, an optical filter 4 was produced.

The optical filter 4 obtained as described above was evaluated for reflection performance and durability in the same manner as in Example 1.
The evaluation results were as shown in Table 1 below.

Comparative Example 2
Example 3 except that an acrylic adhesive (SK2094, manufactured by Soken Chemical) was used instead of the polyester adhesive used in Example 3, and an epoxy curing agent (E-5XM, manufactured by Soken Chemical) was used. In the same manner, an optical filter 5 was produced.

  The optical filter 5 obtained as described above was evaluated for reflection performance and durability in the same manner as in Example 1.

Comparative Example 3
Example 1 except that an acrylic adhesive (SK2094, manufactured by Soken Chemical) was used instead of the polyester adhesive used in Example 1, and an epoxy curing agent (E-5XM, manufactured by Soken Chemical) was used. In the same manner, an optical filter 6 was produced.

The optical filter 6 obtained as described above was evaluated for reflection performance and durability in the same manner as in Example 1.
The evaluation results were as shown in Table 1 below.

It is sectional drawing which showed one Embodiment of the optical filter of this invention. It is sectional drawing which showed other embodiment of the optical filter of this invention. It is sectional drawing which showed other embodiment of the optical filter of this invention. It is sectional drawing which showed one Embodiment of the plasma display panel provided with the optical filter of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical filter 2, 2 'Optical functional layer 3 Adhesive layer A, B Interface 4 Functional additive (near infrared absorber)
5 Substrate 6 Coating (Antireflection film or antiglare layer)
7 Functional additives (UV absorbers)
8 Electromagnetic wave shielding layer 9 Adhesive 10 Plasma display panel

Claims (9)

An optical filter for a plasma display panel in which at least two kinds of optical functional layers are laminated via an adhesive layer,
The optical functional layer comprises a base material made of a polyester-based resin, or a base material and a coating provided on the surface thereof,
At least one of the base material, the coating film, or the pressure-sensitive adhesive layer contains a material that exhibits an optical function,
The optical filter, wherein the adhesive layer is made of a polyester resin.   The optical filter according to claim 1, wherein the optical function is at least one selected from the group consisting of antireflection, antiglare, ultraviolet absorption, near infrared absorption, neon light absorption, electromagnetic wave shielding, and color correction.   The optical filter according to claim 1 or 2, wherein a difference in refractive index between the optical functional layer and the pressure-sensitive adhesive layer is 0.1 or less.   The optical filter according to claim 2 or 3, wherein the pressure-sensitive adhesive layer contains a near-infrared absorber. The optical filter according to claim 4, wherein the near-infrared absorber comprises at least one of the following four types of phthalocyanine compounds (A) to (D).
Phthalocyanine compound (A):
A compound represented by the following formula [I] (provided that at least four of A ^{1 to} A ¹⁶ are substituents via a sulfur atom, and at least three have a chlorine atom. M ¹ is oxidized) Vanadium.)
Phthalocyanine compound (B):
A compound represented by the following formula [I] (provided that at least four of A ^{1 to} A ¹⁶ are substituents via a sulfur atom and substantially have no chlorine atom. M ¹ is Vanadium oxide.)
Phthalocyanine compound (C):
A compound represented by the following formula [I] (provided that at least four of A ^{1 to} A ¹⁶ are a substituent via a nitrogen atom and substantially free of a substituent via a sulfur atom). M ¹ is vanadium oxide.)
Phthalocyanine compound (D):
A compound represented by the following formula [I] (provided that at least four of A ^{1 to} A ¹⁶ are a substituent via a nitrogen atom and are substantially free of a substituent via a sulfur atom. ¹ is copper.)

(In the formula, A ^{1 to} A ¹⁶ may each independently contain a hydrogen atom, a halogen atom, a hydroxyl group, an amino group, a hydroxysulfonyl group, an aminosulfonyl group, or a nitrogen atom, a sulfur atom, an oxygen atom, or a halogen atom. (It represents a substituent having 1 to 20 carbon atoms, and two adjacent substituents may be linked via a linking group. M ¹ represents vanadium oxide or copper.)   The optical filter according to any one of claims 1 to 5, wherein the visible light transmittance is at least 30% or more.   The optical filter according to any one of claims 1 to 6, which is used in a plasma display panel.   The plasma display panel provided with the optical filter as described in any one of Claims 1-7.   The plasma display panel according to claim 8, wherein the optical filter is provided on the entire surface of the panel.

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