JP2012116940A - Adhesive composition, and composite filter for plasma display - Google Patents

Abstract

A pressure-sensitive adhesive used for adhering a glass substrate of a PDP and a composite filter, which is excellent in adhesive force and has no adhesive residue and reworkability.
A pressure-sensitive adhesive composition for adhering a glass substrate disposed in front of a panel of a plasma display and a composite filter provided in front of the glass substrate, the peel strength of the pressure-sensitive adhesive with respect to the glass substrate Is 1.0 to 15.0 N / 25 mm, and the stress at break of the pressure-sensitive adhesive is 0.15 to 3.0 MPa.
[Selection] Figure 1

Description

  The present invention relates to a pressure-sensitive adhesive composition for adhering a glass substrate disposed on the front surface of a plasma display panel and a composite filter provided on the front surface of the glass substrate.

  As an image display device (also referred to as a display device) such as a monitor of a television or a personal computer, for example, a cathode ray tube (CRT) display device, a liquid crystal display device (LCD), a plasma display device (PDP), an electroluminescence (EL) display device Etc. are known. Among these display devices, plasma display devices that are attracting attention in the field of large-screen display devices use plasma discharge for light emission. Therefore, unnecessary electromagnetic waves in the 30 MHz to 1 GHz band leak to the outside and other devices ( For example, remote control devices, information processing apparatuses, etc.) may be affected. Therefore, it is common to provide a film-like electromagnetic wave shielding sheet for shielding electromagnetic waves leaking on the front side (observer side) of the plasma display panel used in the plasma display device.

  In addition, near infrared rays having a wavelength of 800 to 1,100 nm generated from the front of the display also cause other devices such as VTRs to malfunction, and need to be shielded. Further, there is a case where a function for shielding unnecessary light having a specific wavelength generated from the image display device or providing various functions necessary for the image display device is required. Therefore, in recent years, by laminating a plurality of optical filters such as an electromagnetic wave shielding sheet, a near-infrared absorption filter, and an antireflection filter, the unnecessary electromagnetic waves generated from the plasma display device and light of a specific wavelength are shielded, In addition, it has been proposed to provide a plate or sheet-like composite filter on the observer side of the plasma display panel, which can provide various functions required for the display device (JP 2007-243103 A, etc.). .

  A composite filter provided as a front plate of a plasma display panel is obtained by applying a pressure sensitive adhesive or adhering a composite panel provided with an adhesive sheet to a front glass substrate of a panel body of a plasma display device. And are fixed. Naturally, the pressure-sensitive adhesive or pressure-sensitive adhesive sheet needs to have strong adhesiveness so that the composite filter does not peel off from the glass substrate.

  In recent years, with the increase in the size and definition of plasma display panels, the positional accuracy of the glass substrate of the plasma display panel and the composite filter has increased, and the composite filter is peeled off when misalignment occurs. Then, re-stretching may be performed. In this case, depending on the pressure-sensitive adhesive used, a so-called “glue residue” in which the pressure-sensitive adhesive on the composite filter side remains on the glass substrate side may occur, and there is a problem that the glass substrate with the glue remaining cannot be reused.

JP 2007-243103 A

  The present inventors paid attention to the stress at break and the peel strength of the pressure-sensitive adhesive. If the stress at break and the peel strength are within a specific range, the adhesive strength is excellent, while no adhesive residue remains, It was found that an adhesive having excellent usability (hereinafter also referred to as reworkability) can be realized. The present invention is based on this finding.

  Therefore, the present invention is an adhesive used when adhering a glass substrate and a composite filter of a plasma display panel (hereinafter may be simply referred to as PDP), which is excellent in adhesive force, but has no adhesive residue. In addition, the present invention provides an adhesive having excellent reworkability.

  Another object of the present invention is to provide a composite filter for plasma display in which the above-mentioned pressure-sensitive adhesive is applied to one surface, and a plasma display provided with the composite filter.

The pressure-sensitive adhesive composition according to the present invention is a pressure-sensitive adhesive composition for adhering a glass substrate disposed on the front surface of a plasma display panel and a composite filter provided on the front surface of the glass substrate,
The peel strength with respect to the glass substrate is 1.0 to 15.0 N / 25 mm, and the stress at break is 0.15 to 3.0 MPa.

In the embodiment of the present invention, when the peel strength is P (N / 25 mm) and the stress at break is S (MPa), the S / P is 0.07 to 0.26 (2.5 × It is preferable to satisfy the relationship of 10 ² · m ⁻¹ ).

  In the aspect of the present invention, the glass substrate is preferably soda lime glass or high strain point glass having a thickness of 1 to 5 mm and a thickness deviation of 15 μm or less.

  Moreover, in the aspect of this invention, it is preferable that an adhesive is an acrylic resin-type adhesive.

In the embodiment of the present invention, it is preferable that a storage modulus at 25 ° C. is ^{1.3 × 10 5 Pa~4.0 × 10 5} Pa.

Moreover, in the aspect of this invention, it is preferable that the loss elastic modulus in 25 degreeC is 7.9 * 10 < ³ > Pa-1.8 * 10 < ⁵ > Pa.

  Moreover, in the aspect of this invention, it is preferable to contain at least 1 or more types of absorbers selected from the group which consists of a near-infrared absorber, a neon light absorber, a ultraviolet absorber, and a color tone adjustment pigment | dye.

  In another aspect of the present invention, a composite filter is also provided in which an adhesive layer comprising the above-mentioned adhesive composition is provided on one surface.

  Further, the composite filter according to the present invention is a group comprising an electromagnetic wave shielding function, a near infrared shielding function, a neon light shielding function, an ultraviolet shielding function, an antireflection function, an antiglare function, an anti-scratch function, an antifouling function, and an antistatic function. It is preferable to have at least one function selected from

  In another aspect of the present invention, there is also provided a plasma display in which the composite filter is attached to the front surface of a glass substrate.

  According to the present invention, an adhesive composition having a peel strength with respect to a glass substrate of 1.0 to 15.0 N / 25 mm and a stress at break of 0.15 to 3.0 MPa provides an adhesive strength. In addition, it is possible to realize a pressure-sensitive adhesive having no adhesive residue and excellent reworkability.

It is the schematic sectional drawing which showed one Embodiment of the composite filter by this invention. It is the schematic sectional drawing which showed other embodiment of the composite filter by this invention. It is the schematic sectional drawing which showed other embodiment of the composite filter by this invention. It is a schematic sectional drawing when the composite filter by this invention is stuck on the glass substrate for PDP.

<Adhesive composition>
The pressure-sensitive adhesive composition according to the present invention is for adhering a glass substrate disposed on the front surface of a plasma display panel and a composite filter provided on the front surface of the glass substrate, and has a peel strength with respect to the glass substrate. 1.0 to 15.0 N / 25 mm, and the stress at break is 0.15 to 3.0 MPa. When the peel strength and the stress at break are within the above ranges, the glass substrate and the composite filter can be firmly bonded via the adhesive layer, and the composite filter is peeled off from the glass substrate after bonding. However, it will be excellent in the rework property in which an adhesive does not remain on a glass substrate. The reason for this is not clear, but is considered as follows. That is, when the peel strength is 1.0 N / 25 mm or less, regardless of the breaking stress of the adhesive, the force for adhering the glass substrate and the composite filter is too weak, and the composite filter is used when using the PDP after attachment. May peel off. On the other hand, when the peel strength exceeds 15.0 N / 25 mm, the adhesive strength is strong, but when the composite filter is peeled from the glass substrate, the breakage occurs in the pressure-sensitive adhesive layer before the pressure-sensitive adhesive layer is peeled from the glass substrate. As a result, a part of the adhesive layer remains (adhesive residue) on the glass substrate. When the stress at break of the pressure-sensitive adhesive composition is less than 0.15 MPa, the pressure-sensitive adhesive layer easily breaks during the peeling. On the other hand, when the stress at break exceeds 3.0 MPa, the adhesive residue is suppressed, but a load is applied when the adhesive layer is punched and the workability is deteriorated. In addition, peeling strength means the value measured with the following measuring methods. An adhesive composition coated on one side of a 100 μm thick biaxially stretched polyethylene terephthalate film to a thickness of 25 g / m ² (when dried) was cut out to a length of 150 mm and a width of 25 mm. The pressure-sensitive adhesive composition coating layer faces the glass plate side, and is attached to a glass plate having a thickness of 10 mm with a degreased surface, and this is attached to a glass plate and a biaxially stretched polyethylene terephthalate film using a tensile tester. Means tensile strength when pulled and peeled in an atmosphere of 20 to 25 ° C. in a direction where the angle of both becomes 180 ° at a pulling speed of 300 mm / min. Further, the breaking stress means that the coating layer of the above-mentioned pressure-sensitive adhesive composition is peeled off from the biaxially stretched polyethylene terephthalate film so as to be in a state of only the coating layer, and this is rolled into a roll tester. It means the stress at break when gripped with a chuck and subjected to a tensile test in an atmosphere of 20 to 25 ° C. at a tensile speed of 100 mm / min. In addition, as a glass substrate to be used, it is preferable to use the glass substrate for PDP, especially a soda lime glass or a high strain point glass having a thickness of 1 to 5 mm and a thickness deviation of 15 μm or less.

In the present invention, when the adhesive composition has a peel strength of P (N / 25 mm) and the breaking stress is S (MPa), the S / P is 0.07 to 0.26 (2.5 It is preferable that the relationship of × 10 ² · m ⁻¹ ) is satisfied. By satisfying the above relationship, it is possible to realize a pressure-sensitive adhesive composition having a stronger sticking force and excellent reworkability.

In the present invention, it is preferable that a storage modulus at 25 ° C. of the adhesive composition is ^{1.3 × 10 5 Pa~4.0 × 10 5} Pa, 2.3 × 10 5 Pa~3. More preferably, it is 3 × 10 ⁵ Pa. When the storage elastic modulus is in the above range, it is possible to realize a pressure-sensitive adhesive that is further excellent in adhesive strength and has no adhesive residue and reworkability. Moreover, it is preferable that the loss elastic modulus in 25 degreeC is 7.9 * 10 < ³ > Pa-1.8 * 10 < ⁵ > Pa, and it is more preferable that it is 4.0 * 10 < ⁴ > Pa-1.1 * 10 < ⁵ > Pa. preferable. When the loss elastic modulus is in the above range, it is possible to realize a pressure-sensitive adhesive that is further excellent in adhesive force and has no adhesive residue and reworkability. In addition, the storage elastic modulus E ′ and the loss elastic modulus E ″ in the present invention are one of dynamic mechanical properties, and are values obtained by a torsional deformation mode as described in JIS-K-7244-1. . By applying a strain or stress that changes (vibrates) over time to the sample, and detecting the stress or strain generated by the strain or stress, it is stored inside the sample among the values obtained by measuring the mechanical properties of the sample. This value is called storage elastic modulus E ′, and the value lost due to internal friction is called loss elastic modulus E ″. The loss tangent tan δ is a ratio of loss elastic modulus E ″ / storage elastic modulus E ′.

  Examples of the pressure-sensitive adhesive composition having a peel strength and a stress at break within the above ranges include natural rubber, synthetic rubber, acrylic resin, polyvinyl ether resin, urethane resin, and silicone resin. Specific examples of synthetic rubbers include styrene-butadiene rubber, acrylonitrile-butadiene rubber, polyisobutylene rubber, isobutylene-isoprene rubber, styrene-isoprene block copolymer, styrene-butadiene block copolymer, styrene-ethylene-butylene block. A copolymer is mentioned. Specific examples of the silicone resin system include dimethylpolysiloxane. These pressure-sensitive adhesives can be used singly or in combination of two or more. Among these, an acrylic adhesive is preferable.

  The acrylic resin pressure-sensitive adhesive is a polymer containing at least a (meth) acrylic acid alkyl ester monomer. Generally, it is a copolymer of a (meth) acrylic acid alkyl ester monomer having an alkyl group having about 1 to 18 carbon atoms and a monomer having a carboxyl group. In addition, (meth) acrylic acid means acrylic acid and / or methacrylic acid. Examples of (meth) acrylic acid alkyl ester monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, sec-propyl (meth) acrylate, (meth) acrylic acid. n-butyl, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) acrylic acid Examples thereof include n-octyl, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, undecyl (meth) acrylate, and lauryl (meth) acrylate. Moreover, the said (meth) acrylic-acid alkylester is normally copolymerized in the ratio of 30-99.5 mass parts in the acrylic adhesive.

  Moreover, as a monomer which has a carboxyl group which forms acrylic resin adhesive, the monomer containing carboxyl groups, such as (meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, monobutyl maleate, and (beta) -carboxyethyl acrylate Can be mentioned.

  In addition to the above, the acrylic resin pressure-sensitive adhesive may be copolymerized with a monomer having another functional group within a range not impairing the characteristics of the acrylic resin pressure-sensitive adhesive. Examples of monomers having other functional groups include monomers containing hydroxyl groups such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and allyl alcohol; (meth) acrylamide, N-methyl Monomers containing amide groups such as (meth) acrylamide and N-ethyl (meth) acrylamide; Monomers containing amide groups and methylol groups such as N-methylol (meth) acrylamide and dimethylol (meth) acrylamide; Monomers having functional groups such as amino group-containing monomers such as meth) acrylate, dimethylaminoethyl (meth) acrylate and vinylpyridine; epoxy group-containing monomers such as allyl glycidyl ether and (meth) acrylic acid glycidyl ether -Etc. In addition, fluorine-substituted (meth) acrylic acid alkyl ester, (meth) acrylonitrile and the like, vinyl group-containing aromatic compounds such as styrene and methylstyrene, vinyl acetate, and vinyl halide compounds can be used.

  In the acrylic resin pressure-sensitive adhesive, in addition to the monomer having another functional group as described above, another monomer having an ethylenic double bond can be used. Examples of monomers having an ethylenic double bond include diesters of α, β-unsaturated dibasic acids such as dibutyl maleate, dioctyl maleate and dibutyl fumarate; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers A vinyl aromatic compound such as styrene, α-methylstyrene and vinyltoluene; (meth) acrylonitrile and the like. In addition to the monomer having an ethylenic double bond as described above, a compound having two or more ethylenic double bonds may be used in combination. Examples of such compounds include divinylbenzene, diallyl malate, diallyl phthalate, ethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, methylene bis (meth) acrylamide, and the like.

  Furthermore, in addition to the above-described monomers, monomers having an alkoxyalkyl chain can be used. Examples of (meth) acrylic acid alkoxyalkyl esters include 2-methoxyethyl (meth) acrylate, methoxyethyl (meth) acrylate, 2-methoxypropyl (meth) acrylate, and 3-methoxypropyl (meth) acrylate. , 2-methoxybutyl (meth) acrylate, 4-methoxybutyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-ethoxypropyl (meth) acrylate, 4-ethoxybutyl (meth) acrylate And so on.

  As an adhesive composition, the homopolymer of the (meth) acrylic-acid alkylester monomer other than the above-mentioned acrylic resin adhesive may be sufficient. For example, (meth) acrylic acid ester homopolymers include poly (meth) acrylate methyl, poly (meth) ethyl acrylate, poly (meth) acrylate propyl, poly (meth) acrylate butyl, poly (meth) Examples include octyl acrylate. As a copolymer containing 2 or more types of acrylate units, methyl (meth) acrylate- (meth) ethyl acrylate copolymer, (meth) methyl acrylate- (meth) butyl acrylate copolymer, ( Examples include methyl (meth) acrylate- (meth) acrylic acid 2-hydroxyethyl copolymer, methyl (meth) acrylate- (meth) acrylic acid 2-hydroxy-3-phenyloxypropyl copolymer, and the like. As a copolymer of (meth) acrylic acid ester and other functional monomers, (meth) methyl acrylate-styrene copolymer, (meth) methyl acrylate-ethylene copolymer, (meth) acrylic A methyl acid- (meth) acrylic acid 2-hydroxyethyl-styrene copolymer is mentioned.

  Commercially available pressure-sensitive adhesives may be used. For example, SK Dyne 2094 (manufactured by Soken Chemical Co., Ltd.), SK Dyne 2147 (manufactured by Soken Chemical Co., Ltd.), SK Dyne 1811L (manufactured by Soken Chemical Co., Ltd.), SK Dyne 1442 (manufactured by Soken Chemical Co., Ltd.) SK Dyne 1435 (manufactured by Soken Chemical Co., Ltd.), SK Dyne 1415 (manufactured by Soken Chemical Co., Ltd.), Olivevine EG-655 (manufactured by Toyo Ink Co., Ltd.), or As described above, the product name) can be preferably used.

  Moreover, you may use together a hardening | curing agent with the above-mentioned adhesive. By using a curing agent in combination, a crosslinked structure is formed, and a pressure-sensitive adhesive composition having a higher stress at break is obtained. Various curing agents can be used, for example, an isocyanate curing agent, an epoxy curing agent, an amine curing agent, a metal chelate curing agent, etc. Among them, an isocyanate curing agent is preferable. . As isocyanate curing agents, fats such as aromatic isocyanates such as tolylene diisocyanate, naphthylene-1,5-diisocyanate, diphenylmethane diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, trimethylolpropane diisocyanate And isocyanate compounds such as aliphatic isocyanates and alicyclic isocyanates. These isocyanate compounds may be used in the form of adducts and multimers. Commercially available curing agents may be used. For example, E-5XM (manufactured by Soken Chemical Co., Ltd.), E-5C (manufactured by Soken Chemical Co., Ltd.), TD75 (manufactured by Soken Chemical Co., Ltd.), BXX5627 (Toyo) (Manufactured by Ink Manufacturing Co., Ltd.), X-301-422SK (manufactured by Syden Chemical Co., Ltd.), etc. (above, trade names) can be suitably used.

<Composite filter>
In the composite filter 1 according to the present invention, as shown in FIG. 1, an adhesive layer 2 made of the above-mentioned adhesive composition is provided on one surface of a layer 3 made of an electromagnetic wave shielding filter and / or an optical filter described later. It is directly attached to the surface of the front glass substrate 9 of the PDP through the adhesive layer 2. Hereinafter, each layer constituting the composite filter will be described.

<Adhesive layer>
The pressure-sensitive adhesive layer 2 constituting the composite filter 1 is made of the above-mentioned pressure-sensitive adhesive composition. It can be formed by applying the above-mentioned pressure-sensitive adhesive composition to one surface of the layer 3 composed of the electromagnetic wave shielding filter 4 and / or the optical filter 5 and drying it. At the time of coating, the flowability may be improved by diluting the pressure-sensitive adhesive composition with a solvent in consideration of applicability. As the solvent, conventionally known solvents can be used. For example, hydrocarbon solvents such as toluene, ketone solvents such as acetone, and the like can be used. Moreover, as a coating method, conventionally well-known coating apparatuses, such as a roll coat, a gravure roll coat, a bar coat, a curtain flow coat, a die coat, a comma coat, a spray coat, can be adopted.

The composite filter 1 according to the present invention is attached to the PDP front glass substrate 9, but may be transported or stored after the composite filter is manufactured and before being attached to the PDP front glass substrate. Therefore, the adhesive layer 2 may be protected with a separator 6 on the surface of the adhesive layer 2 as shown in FIG. The separator 6 is peeled off when the composite filter 1 is attached to the surface of the PDP front glass substrate. Further, in order to protect not only the adhesive layer 2 but also the surface of the composite filter 1, the surface opposite to the surface on which the adhesive layer is provided may be protected by the separator 7. A conventionally well-known thing can be used as such a separator, for example, the resin sheet of about 20-100 micrometers in thickness, or the paper of a basic weight of 20-100 g / m < ² > is used. Examples of the resin sheet include polyester resin sheets such as polyethylene terephthalate and polyethylene naphthalate, and polyolefin resin sheets such as polypropylene and polymethylpentene. As the paper, high quality paper, parchment paper, glassine paper, sulfuric acid paper or the like that is as uniform as possible is used.

<Electromagnetic wave shielding filter / optical filter>
The composite filter adhered to the PDP front glass substrate 9 is at least one selected from the group consisting of an electromagnetic wave shielding function, a near infrared shielding function, a neon light shielding function, an ultraviolet shielding function, an antireflection function, and an antiglare function. A filter function and, if necessary, a function other than at least one filter selected from the group consisting of an anti-scratch function, an antifouling function, an impact resistance function, an antibacterial function, and an antistatic function It is. As a preferred embodiment of the present invention, the adhesive layer 2 described above is preferably provided on the conductive mesh layer 40 of the electromagnetic wave shielding filter 4 as shown in FIG. Since the surface of the conductive mesh layer 41 is uneven, the conductive mesh layer 41 is flattened by providing the adhesive layer 2, so that the electromagnetic wave shielding filter 4 can be directly attached to the PDP glass substrate. The adhesive layer 2 is preferably provided so as to expose only the peripheral portion 40A of the conductive mesh layer 40. By providing the peripheral portion 40A of the conductive mesh layer 40 with a portion where the adhesive layer 2 is not provided, the conductive mesh layer 40 can be used as a grounding region.

  As shown in FIG. 1, the composite filter 1 preferably has an optical filter 5 laminated on the surface of the electromagnetic wave shielding filter 4 opposite to the side on which the adhesive layer 2 is provided. As the optical filter 5, for example, it is preferable to provide a near infrared absorption layer 50 on the electromagnetic wave shielding filter 4 side and an ultraviolet absorption layer 51 on the observer side. By providing the near-infrared absorbing layer 50 and the ultraviolet absorbing layer 51 in this order, it is possible to more effectively suppress deterioration of the optical filter due to ultraviolet rays from external light (sunlight or illumination light).

  An antireflection film 52 may be further provided on the ultraviolet absorbing layer 51 (the surface on the observer side). The antireflection film 52 may also serve as a layer having an antiglare function and an anti-scratch function in addition to the function of reflecting external light. Further, as shown in FIG. 3, the ultraviolet absorbing layer 51 itself is anti-scratch. The antireflection film 52 may be provided under the ultraviolet absorbing layer 51 (on the PDP front glass substrate 9 side). In this case, the antireflection film 52 may have an antiglare function.

  The electromagnetic wave shielding filter 4 and the optical filter 5 are laminated via an adhesive layer 8. As a preferred embodiment of the present invention, a neon light absorbing dye and / or a color tone adjusting dye is contained in at least one of the above-mentioned pressure-sensitive adhesive layer 2, adhesive layer 8 or near infrared absorbing layer 50 to absorb neon light. You may make it function as a layer and / or a color tone adjustment layer. Hereinafter, each layer or filter described above will be described.

<Electromagnetic wave shielding filter>
The electromagnetic wave shielding filter 4 includes a transparent resin base material 41 and a conductive mesh layer 40 provided on one surface of the transparent resin base material 41. The transparent resin base material 41 is provided to reinforce the conductive mesh layer 40. As shown in FIG. 1, the conductive mesh layer 40 has a mesh area 40B (area provided with an opening) corresponding to an image display area of the PDP and an opening formed in the peripheral portion thereof. The peripheral edge portion 40A is not included. This peripheral portion 40A is provided as a grounding region so that it can be easily grounded when the composite filter is bonded to the PDP. The peripheral portion 40A is preferably a non-mesh region having no opening as shown in FIG. 1 in order to reduce the ground resistance, but it has a mesh form (not shown) similar to the mesh region 40B. It can also be.

  The conductive mesh layer 40 has a blackened layer 42 on the surface on the transparent resin base material 41 side. An adhesive layer (not shown) for attaching the conductive mesh layer 40 to the transparent resin base material 41 may be provided between the conductive mesh layer 40 and the transparent resin base material 41. Further, the conductive mesh layer 40 may include other layers (not shown) such as a rust prevention layer in addition to the blackening layer 42. Furthermore, the electromagnetic wave shielding filter 4 may be formed by laminating layers (not shown) having no conductivity on the front and back surfaces of the conductive mesh layer 40. As a layer which does not have electroconductivity, a rust prevention layer, a blackening layer, etc. are mentioned, for example. Even if it is a rust prevention layer, a blackening layer, etc., as long as it has electroconductivity, it is contained in an electroconductive mesh layer in this invention. The non-conductive layer further laminated on the front and back surfaces of the conductor layer is integrated with the conductive mesh layer to form a mesh region or a (non-mesh region) grounding region.

  The transparent resin substrate 41 needs to have a certain degree of mechanical strength and light transmittance as described above. For example, such resin base materials include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, terephthalic acid-isophthalic acid-ethylene glycol copolymer, polyesters such as terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer, etc. Resins, polyamide resins such as nylon 6, polyolefin resins such as polypropylene and polymethylpentene, acrylic resins such as polymethyl methacrylate, styrene resins such as polystyrene and styrene-acrylonitrile copolymers, and celluloses such as triacetyl cellulose Resin, imide resin, polycarbonate resin and the like.

  The transparent resin substrate may be a single resin as described above, or may be a plurality of types of mixed resins (including polymer alloys). Further, it may be a single layer or a laminate of two or more layers. In addition, the resin base material is more preferably uniaxially or biaxially stretched from a film or sheet made of the above-described resin from the viewpoint of mechanical strength. From these viewpoints, among the above-mentioned resins, polyester resin sheets such as polyethylene terephthalate and polyethylene naphthalate are preferable in terms of transparency, heat resistance, cost, and the like, and more preferably biaxially stretched polyethylene terephthalate is optimal. . In addition, although the transparency of a transparent resin base material is so good that it is good, Preferably biaxially-stretched polyethylene terephthalate with the light transmittance of 80% or more by visible light transmittance | permeability can be used conveniently.

  In the transparent resin base material, additives such as an ultraviolet absorber, a filler, a plasticizer, and an antistatic agent may be appropriately added as necessary. Moreover, although the thickness of a transparent resin base material can be suitably determined according to a use, it is about 12-500 micrometers normally, Preferably it is 50-200 micrometers, More preferably, it is 50-125 micrometers. If the thickness is less than 12 μm, the mechanical strength may be insufficient and warp, slack, breakage, and the like may occur. If the thickness exceeds 500 μm, the excess performance increases the cost and it is difficult to reduce the thickness.

  The transparent resin base material 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 on the surface. Also good.

  The conductive mesh layer 40 is a layer responsible for an electromagnetic wave shielding function, and is itself opaque, but by providing an opening with a mesh shape, both electromagnetic wave shielding performance and light transmittance are achieved. Is a layer. The conductive mesh layer is formed of a metal foil or the like, and a blackened layer is formed by a blackening process on the surface of the conductive mesh layer on the side to be bonded to the transparent resin base material.

  In general, the conductive mesh layer is typically formed by etching a metal foil, but even if it is other than this, the material and the forming method are not particularly limited, and conventionally known Various conductive mesh layers in the light-transmitting electromagnetic wave shielding filter can be appropriately employed. For example, a conductive mesh layer formed in the shape of a mesh on a transparent substrate from the beginning using printing of an ink made of a conductive composition or a metal pattern plating method, or initially on a transparent substrate Alternatively, the conductive layer may be formed on the entire surface using a physical / chemical forming method such as vapor deposition, sputtering, or plating, and then formed into a mesh shape by etching or the like. .

  The conductive mesh layer formed by etching can be formed into a mesh-like conductive mesh layer by patterning a single metal foil before lamination on a transparent resin substrate by etching. The conductive mesh layer of this single layer is laminated on the transparent resin substrate with an adhesive or the like. Among these, a transparent base sheet with an adhesive is used for the metal foil in that it is easy to handle a conductive mesh layer having a low mechanical strength, is excellent in productivity, and can use a commercially available metal foil. After being laminated, it is preferably processed into a mesh by etching. As the adhesive in this case, a known adhesive can be used.

  The conductive material forming the conductive mesh layer is not particularly limited as long as it is a substance having conductivity, and is usually a metal such as gold, silver, platinum, copper, iron, nickel, chromium, aluminum, etc. Is preferably used. A conductive mesh layer can be formed from these metals by a method such as vapor deposition, plating, or metal foil lamination. The metal may be an alloy, and the metal layer may be a single layer or multiple layers. For example, in the case of iron, low carbon steel such as low carbon rimmed steel and low carbon aluminum killed steel, Ni-Fe alloy, Invar alloy and the like are preferable. On the other hand, when the metal is copper, the metal material is copper or a copper alloy, and there are rolled copper foil and electrolytic copper foil as the copper foil, but the thinness and uniformity thereof, the adhesion with the blackened layer, etc. Is preferably an electrolytic copper foil. When the conductive mesh layer is formed by printing a conductive composition (conductive ink), the conductive material made of the metal or graphite is made into particles having an average particle size of about 0.1 to 10 μm, and acrylic resin or polyester resin. In a binder resin such as urethane resin, about 50 to 95% by mass is added and dispersed.

  The thickness of the conductive mesh layer is about 1 to 50 μm, preferably 2 to 15 μm. If the thickness is too thin, it will be difficult to obtain a sufficient electromagnetic wave shielding function due to an increase in electrical resistance. If the thickness is too thick, it will be difficult to obtain a high-definition mesh shape, and the uniformity of the mesh shape will be reduced. .

  The front and back surfaces of the metal layer serving as the conductive mesh layer may be roughened when it is necessary to improve the adhesion with adjacent layers such as a transparent adhesive layer for adhesion and lamination with the transparent substrate. Since the surface to be bonded to the transparent resin substrate side is blackened, the surface roughness is a ten-point average roughness of the contour curve when the roughness curve is adopted as the contour curve of the surface of the metal layer to be the conductive mesh layer. RzJIS (JIS B0601 (1994 edition)) is preferably about 0.5 to 1.5 μm.

  The blackened layer 42 (or the blackened surface) is for preventing light reflection on the surface of the conductive mesh layer 40, and the blackened surface formed by the blackening treatment causes the conductive mesh layer surface. This prevents the black level of the fluoroscopic image from being lowered due to external light reflection, and improves the bright room contrast of the fluoroscopic image, thereby improving the visibility of the image on the display. The blackened layer or the blackened surface is preferably provided on all surfaces of the line portion (linear portion) of the conductive mesh layer, but in the present invention, at least the side to be bonded to the transparent resin base material on the front and back surfaces is provided. It is preferable to use a blackened surface. The reason is that this surface side is the observer side as well as the outside light incident side. The surface opposite to the side to which the conductive mesh layer is bonded and the side surface (both sides or one side) may be further blackened. The blackening layer may be provided at least on the viewing side. However, when the blackening layer is also provided on the display surface side, stray light generated from the display can be suppressed, so that the visibility of the image is further improved. Note that the conductive mesh layer 40 may be positioned on the image observer side (in FIG. 1, the optical filter 5 side) in the opposite direction to FIG. 1. In this case, the blackening layer or the blackening treatment surface 42 is set so as to be located on the opposite side of the conductive mesh layer 40 from the transparent base material, that is, on the image observer side (not shown).

  The blackening treatment can be performed by roughening the surface of the conductive mesh layer or imparting light absorptivity (blackening) over the entire visible light spectrum. As a specific blackening treatment, in addition to providing a conductive mesh layer with a blackening layer by plating or the like, the layer itself constituting the surface from the surface toward the inside by etching or the like is changed to a blackening layer. Also good.

  The blackening layer is not particularly limited as long as it has a dark color such as black, dark gray, brown, dark blue, rosy, dark green, etc., and satisfies basic physical properties such as adhesion. obtain. Therefore, as the blackening layer, an inorganic material such as a metal, an organic material such as a black colored resin, or the like can be used. For example, as the inorganic material, a metal compound such as a metal, an alloy, a metal oxide, or a metal sulfide is used. It is formed as a metal-based layer. As a method for forming the metal layer, various conventionally known blackening methods can be appropriately employed. Especially, the blackening process by a plating method is preferable at adhesiveness, uniformity, ease, etc. As a material for the plating method, for example, a metal such as copper, cobalt, nickel, zinc, molybdenum, tin, or chromium, a metal compound, or the like is used. These are superior to the case of cadmium or the like in terms of adhesion and blackness.

  When the conductive mesh layer is made of copper, such as copper foil, as a preferable plating method for the blackening treatment for forming the blackened layer, a conductive mesh layer made of copper (if the conductive mesh layer is formed before forming the mesh, the previous There is a cathodic electrodeposition plating method in which the electroconductive layer) is subjected to cathodic electrolysis in an electrolytic solution made of sulfuric acid, copper sulfate, cobalt sulfate or the like, and cationic particles are adhered. According to this method, the rough surface can be obtained simultaneously with the black color by the adhesion of the cationic particles. Copper particles and copper alloy particles can be adopted as the cationic particles. The copper alloy particles are preferably copper-cobalt alloy particles, and the average particle diameter is preferably 0.001 to 1 μm. A blackened layer composed of a copper-cobalt alloy particle layer is obtained by the copper-cobalt alloy particles. The cathodic electrodeposition method is also preferable in that the average particle diameter of the cationic particles to be adhered is adjusted to 0.001 to 1 μm. When the average particle diameter exceeds the above range, the density of the adhered particles is reduced, blackness is reduced and unevenness occurs, and particle falling off (powder falling) is likely to occur. On the other hand, even if the average particle diameter is less than the above range, the blackness is lowered. In the cathodic electrodeposition method, when the treatment is performed at a high current density, the treated surface becomes cathodic, and activated by reducing hydrogen generation, the adhesion between the copper surface and the cationic particles is remarkably improved.

  As the blackening layer, black chrome, black nickel, nickel alloy and the like are also preferable, and examples of the nickel alloy include a nickel-zinc alloy, a nickel-tin alloy, and a nickel-tin-copper alloy. In particular, the nickel alloy has a good degree of blackness and conductivity, can also impart a rust prevention function to the blackened layer (becomes a blackened layer and a rustproof layer), and can omit the rustproof layer. In addition, since the particles of the blackened layer are usually needle-like, the appearance is likely to change due to external force, but the blackened layer made of nickel alloy is difficult to deform and the appearance is difficult to change in the post-processing step. Benefits. In addition, the formation method of a nickel alloy as a blackening layer may be a known electrolytic or electroless plating method, and the nickel alloy may be formed after nickel plating.

  When the conductive mesh layer is copper, there is also a method in which the conductive mesh layer is reacted with an alkaline solution to be oxidized and copper oxide fine particles are deposited on the surface. For example, as described in JP-A-2002-9484, a method of immersing a copper mesh layer in a mixed solution of a copper pyrophosphate aqueous solution, a potassium pyrophosphate aqueous solution, and an ammonia aqueous solution can be used.

  A preferable black density of the blackened layer is 0.6 or more. Note that the black density measurement method was set to COLORITSPM100-11 (product name) manufactured by COLORCONTROLLS, with an observation viewing angle of 10 degrees, an observation light source D50, and an illumination type of density standard ANSIT, and after white calibration. Measure the specimen. Further, the light reflectance of the blackened layer is preferably 5% or less. The light reflectance is measured using a haze meter HM150 (trade name, manufactured by Murakami Color Co., Ltd.) in accordance with JIS-K7105. In addition, instead of measuring the reflectance, the Y value of reflection may be expressed by a color difference meter. In this case, the Y value is preferably 10 or less.

  As the conductive mesh layer, other layers may be appropriately formed or processed as necessary. For example, when the durability against rust is insufficient, a rust prevention layer may be provided. As with the blackened layer, the rust preventive layer is included in the conductive mesh layer as long as the mesh shape is maintained.

  The rust preventive layer is not particularly limited as long as it is less likely to rust than the conductive mesh layer covered with it, such as an inorganic material such as metal, an organic material such as resin, or a combination thereof. In some cases, the blackened layer is also covered with a rust-preventing layer, so that the particles of the blackened layer can be prevented from falling off and deformed, and the blackness of the blackened layer can be increased. Therefore, in the present invention, it is preferable that a rust-preventing layer is provided on the blackening layer on the side to be bonded to the transparent resin base material from the standpoint of preventing the blackening layer from dropping or preventing alteration.

  A conventionally well-known thing should just be employ | adopted for a rust prevention layer suitably, for example, is a metal thru | or alloys, such as chromium, zinc, nickel, tin, copper, or the layer of a metal compound of a metal oxide. These can be formed by a known plating method or the like. Here, if it shows an example of a rust prevention layer preferable at points, such as a rust prevention effect and adhesiveness, the chromium compound layer obtained by carrying out a chromate process after galvanizing will be mentioned. In addition, the rust preventive layer may contain a silicon compound such as a silane coupling agent in order to improve acid resistance during etching or acid cleaning. The thickness of the rust preventive layer is usually about 0.001 to 2 μm, preferably 0.01 to 1 μm.

  The shape of the conductive mesh layer as a mesh shape is not particularly limited, but a square shape is typical as the shape of the opening of the mesh. The plan view shape of the opening is, for example, a triangle such as a regular triangle, a square such as a square, a rectangle, a rhombus, or a trapezoid, a polygon such as a hexagon, a circle, an ellipse, or the like. The mesh has a plurality of openings having these shapes, and the openings are usually line-shaped line portions having a uniform width. Normally, the openings and the line portions have the same shape and the same size on the entire surface. As an example of a specific size, the width of the line part between the openings is preferably about 5 to 100 μm in terms of the aperture ratio and the invisibility of the mesh. The size of the opening is obtained by subtracting the line width from the line interval or line pitch. The line interval or line pitch is 100 μm to 500 μm and the opening ratio (the total area of the openings / the total area of the mesh part) ) Is preferably 60 to 97% from the viewpoint of compatibility between light transmittance and electromagnetic wave shielding properties.

  Since the region of the peripheral edge portion 40A of the conductive mesh layer is located outside the mesh region 40B facing the image, it is a region where light transmittance is not required as a surface, and is normally used as a grounding region. From the viewpoint of reducing the ground resistance, the peripheral portion is preferably a non-mesh area. When the metal stay is made into a mesh by photoetching, the non-mesh part is easy to form, so the peripheral part is usually a non-mesh area. In addition, when forming a mesh by printing a conductive composition, it may be difficult to form a non-mesh region depending on the printing method and the thickness of the conductive composition. In that case, the peripheral edge is also mesh-shaped. Although the specific size of the peripheral portion 40A depends on how it is used, when the frame is in the shape of a ground or outer frame, the width of the frame is about 15 to 100 mm, and in particular, it is generally 30 to 40 mm. It is.

  An adhesive layer (not shown) may be interposed between the transparent resin substrate and the conductive mesh layer. The adhesive layer also preferably has etching resistance. Specific examples of such an adhesive include polyurethane resins such as polyester urethane, acrylic urethane, and polyether urethane, acrylic resins, polyester resins, and vinyl chloride-acetic acid. Examples thereof include vinyl copolymers, ethylene-vinyl acetate copolymers, and epoxy resins. The adhesive may be an ultraviolet curable type or a thermosetting type. In particular, an acrylic resin or a polyester resin is preferable from the viewpoint of adhesion to a transparent substrate.

  The film thickness of the adhesive layer is 1 μm to 50 μm, preferably 5 μm to 20 μm. Thereby, a transparent resin base material and a conductive mesh layer can be firmly adhered, and the transparent resin base material is made of an etching solution such as a ferric chloride aqueous solution during etching to form the conductive mesh layer. It can be prevented from being affected.

<Optical filter>
As shown in FIG. 1, the composite filter 1 according to the present invention may include an optical filter 5 on the electromagnetic wave shielding filter 4 (observer side). As the optical filter 5, a layer having an optical filter function such as an antireflection function, an antiglare function, a near infrared absorption function, an ultraviolet absorption function and the like, and if necessary, an anti-scratch function, an antifouling function, an antistatic function, It is preferable to use at least one or two or more layers selected from layers having functions other than an optical filter such as an impact resistance function and an antibacterial function. Further, in the optical filter 5, the inclusion of the ultraviolet absorber in the layers 51 and 52 disposed on the observation side with respect to the near infrared absorption layer 50 may cause deterioration of the near infrared absorption pigment in the near infrared absorption layer. It is preferable from the viewpoint of preventing it more effectively.

  The optical filter 5 has a transparent resin base material for each individual functional layer, and may be a laminate in which a plurality of individual optical filter functional layers having a transparent resin base material are bonded together. However, in order to reduce the total thickness and manufacturing cost, various functional layers are laminated on both sides of one transparent resin substrate by means of wet film formation methods such as coating and dry film formation methods such as sputtering. preferable. The transparent resin base material functions as a support for forming various functional layers. As will be described later, the transparent resin base material contains an ultraviolet absorber or the like, and the ultraviolet absorption layer 51 is contained. It is good also as a layer which serves as. As a transparent resin base material, the thing similar to the transparent resin base material which comprises an electromagnetic wave shielding filter can be used.

  The total film thickness of the optical filter can be made thin by substantially using one substrate, but it is in the range of 50 to 500 μm, preferably in the range of 100 to 200 μm. By setting it as such a range, it becomes possible to wind a continuous belt in a roll shape having a minimum diameter of 15 cm or less, and thus it is possible to bond the continuous belt optical filter and the continuous electromagnetic wave shielding sheet. , Improve production efficiency.

The following aspects are mentioned as a layer structure of an optical filter. “/” Indicates that the left and right layers are laminated and integrated.
From the observer side,
(1) Transparent resin substrate / near-infrared absorbing layer that also serves as an antireflection layer / ultraviolet absorbing layer,
(2) Transparent resin substrate / near-infrared absorbing layer that also serves as an antireflection layer / scratch resistant functional layer / ultraviolet absorbing layer,
(3) Transparent resin substrate / near-infrared absorbing layer that also serves as an antiglare layer / ultraviolet absorbing layer,
(4) Transparent resin substrate / near-infrared absorbing layer that also serves as an antiglare layer / scratch resistant functional layer / ultraviolet absorbing layer,
(5) Antireflection layer / transparent resin substrate / near infrared absorbing layer that also serves as an ultraviolet absorbing layer,
(6) Antireflection layer also used as an ultraviolet absorbing layer / Abrasion resistant functional layer / Transparent resin substrate / Near infrared absorbing layer,
(7) Antiglare layer / transparent resin substrate / near infrared absorbing layer that also serves as an ultraviolet absorbing layer,
(8) Antiglare layer / Abrasion-resistant functional layer / Transparent resin substrate / Near infrared absorbing layer that also serves as an ultraviolet absorbing layer,
(9) Antireflection layer / ultraviolet absorption layer / transparent resin substrate / near infrared absorption layer,
(10) Anti-scratch functional layer / transparent resin substrate / near infrared absorbing layer that also serves as an antireflection layer / ultraviolet absorbing layer,
(11) Antireflection layer / ultraviolet absorption layer / scratch resistant functional layer / transparent resin substrate / near infrared absorption layer,
(12) Antiglare layer / Ultraviolet absorption layer / Transparent resin substrate / Near infrared absorption layer,
(13) Anti-scratch functional layer / transparent resin substrate / near infrared absorbing layer that also serves as an antiglare layer / ultraviolet absorbing layer,
(14) Antiglare layer / Ultraviolet absorbing layer / Abrasion resistant functional layer / Transparent resin substrate / Near infrared absorbing layer,
(15) Antireflection layer / transparent resin substrate / ultraviolet absorption layer / near infrared absorption layer

  Among the layer configurations described above, the layer configurations (1) to (8) are preferable because the necessary optical functions can be obtained with a small number of layers. Hereinafter, each functional layer will be described.

<Near infrared absorbing layer>
The near-infrared absorbing layer 50 can be formed by a wet film-forming method such as coating on the transparent resin substrate by containing a near-infrared absorbing dye in the binder. As a near-infrared absorbing dye, when an optical filter is applied to the front surface of a plasma display panel, the plasma display panel has a near-infrared region generated when light is emitted using xenon gas discharge, that is, a wavelength region of 800 nm to 1100 nm. What absorbs, the near infrared transmittance of this band is preferably 20% or less, particularly preferably 10% or less. At the same time, the near-infrared absorbing layer preferably has a sufficient light transmittance in the visible light region, that is, in the wavelength region of 380 nm to 780 nm.

  Specific examples of near-infrared absorbing dyes include polymethine compounds, cyanine compounds, phthalocyanine compounds, naphthalocyanine compounds, naphthoquinone compounds, anthraquinone compounds, imonium compounds, diimonium compounds, aminium compounds, pyrylium. Compounds, cerium compounds, squarylium compounds, copper complexes, nickel complexes, dithiol metal complexes organic near infrared absorbing dyes, tin oxide, indium oxide, cesium-containing tungsten oxide, aluminum oxide, zinc oxide, oxidation One or more inorganic near-infrared absorbing dyes such as iron can be used in combination. As the binder resin, a resin such as a polyester resin, a polyurethane resin, an acrylic resin, or an epoxy resin is used. Binder resin drying and curing methods include a drying and solidification method by drying a solvent (or dispersion medium) from a solution (or emulsion), a polymerization method using heat, ultraviolet rays, electron beam energy, and a crosslinking reaction. Alternatively, a curing method using a reaction such as crosslinking or polymerization between a functional group such as a hydroxyl group or an epoxy group in a resin and an isocyanate group in a curing agent can be applied.

  In the present invention, the near-infrared absorbing layer 50 contains a neon light absorbing dye and / or a color tone adjusting dye as described in the above-mentioned adhesive layer, and also functions as a neon light absorbing function and / or a color tone adjusting function. May be.

<Antireflection layer>
The antireflection layer 52 (AR layer) is a single layer of a low refractive index layer or a multilayer structure in which a low refractive index layer and a high refractive index layer are alternately laminated so that the total low refractive index is located on the outermost surface. However, it can be formed by using a dry film formation method such as vapor deposition or sputtering, or a wet film formation method such as coating. Silicon oxide, magnesium fluoride, lithium fluoride, cryolite, fluorine-containing resin, etc. are used for the low refractive index layer, and titanium oxide, zinc sulfide, zirconium oxide, niobium oxide, etc. are used for the high refractive index layer. Used. Here, the high (low) refractive index layer has a relatively high (low) refractive index compared to a layer adjacent to these layers (for example, a transparent resin base material or a low (high) refractive index layer). Means that.

<Abrasion resistant layer (hard coat layer)>
The hard coat layer (HC layer) is, for example, a polyfunctional (meth) acrylate prepolymer such as polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, or trimethylolpropane tri (meth) acrylate, Ionizing radiation curing in which trifunctional or more polyfunctional (meth) acrylate monomers such as pentaerythritol tetra (meth) acrylate and dipentaerythritol hexa (meth) acrylate are used alone or in combination of two or more of these. It can be formed as a coating film using a conductive resin. In addition, (meth) acrylate is a composite notation meaning acrylate or methacrylate. The above-mentioned scratch-resistant layer (hard coat layer) is also diluted with a solvent as necessary, and coated on a transparent resin substrate by a coating method such as roll coating or bar coating. It can be formed by irradiating with ionizing radiation and crosslinking and curing.

<Anti-glare layer>
The anti-glare layer (AG layer) is provided with fine irregularities that irregularly reflect external light on the surface of the layer by forming a coating with an inorganic filler such as silica added to the resin binder or by forming using a shaping plate. Can be formed as a layer. As the resin of the resin binder, a curable acrylic resin, an ionizing radiation curable resin, or the like is preferably used in the same manner as the scratch-resistant layer because surface strength is desired as the surface layer.

<Ultraviolet absorbing layer>
The ultraviolet absorbing layer may be a layer arranged as an independent layer on the observation side than the above-mentioned near infrared absorbing layer, that is, on the incident side of external infrared rays such as sunlight, or more than the above-mentioned near infrared absorbing layer. The other functional layer arranged on the observation side may contain an ultraviolet absorbing layer, and the other functional layer may also serve as the ultraviolet absorbing layer. Moreover, what contained the ultraviolet absorber in the transparent resin base material may be used. Examples of the transparent resin base material containing an ultraviolet absorber include “Tetron film HB type” manufactured by Teijin Limited.
Examples of the ultraviolet absorber include organic compounds such as benzotriazole-based compounds and benzophenone-based compounds, and inorganic compounds composed of particulate zinc oxide, cerium oxide, and the like. As the binder resin used in the case of an independent layer, the resins listed in the near infrared absorption layer column can be used.

<Other layers>
Examples of the other layers include a neon light absorption layer, a color tone adjustment layer, and an antifouling layer. However, from the viewpoint of production efficiency, the neon light absorbing layer and the color tone adjusting layer are formed in the adhesive layer, the adhesive layer, and the near infrared absorbing layer as described above, rather than being formed as a single layer. It is preferable that a color tone adjusting dye is contained and used as a dual-use layer. Even when formed as a single layer, the neon light absorbing dye and the color tone adjusting dye may be those described above.

The antifouling layer is generally a water-repellent or oil-repellent coat, and a siloxane-based, fluorinated alkylsilyl compound or the like can be applied. A fluorine-based or silicone-based resin used as a water-repellent paint can be preferably used. For example, when the low refractive index layer of the antireflection layer is formed of SiO ₂ , a fluorosilicate water-repellent paint is preferably used.

  The optical filter layer described above can be bonded and integrated with the electromagnetic wave shielding filter layer via an adhesive. The adhesive may contain the neon light absorbing dye and / or the color tone adjusting dye described above, and may also have a neon light absorbing function and / or a color tone adjusting function. As the adhesive, the same adhesives as described above can be used.

<Plasma display>
The composite filter described above is a television receiver, a display unit for various measuring instruments and instruments, a display unit for various office equipment and computer equipment, a plasma display (PDP), a cathode ray tube display (CRT), a liquid crystal used for telephones, etc. It is suitable for a front filter of an image display device such as a display (LCD) or an electroluminescent (EL) display, and particularly suitable for a plasma display.

  The plasma display has a configuration in which a large number of discharge cells corresponding to the respective pixels of the plasma display are formed between two glass substrates arranged with a gap therebetween. Each discharge cell is filled with a rare gas such as helium, neon, argon, or xenon, and the inner wall of each discharge cell converts the infrared rays generated by the discharge into red, green, and blue visible rays. A phosphor is applied so that a voltage can be applied to each discharge cell. In the discharge cell to which voltage is applied, discharge occurs and ultraviolet rays are generated. The generated ultraviolet light hits the phosphor in the discharge cell, whereby visible light of the three primary colors red, green, and blue is emitted from each discharge cell. In this way, a desired image can be displayed by controlling the emission of visible light from each discharge cell.

  As shown in FIG. 4, the composite filter 1 according to the present invention is stuck on a glass substrate 9 (front glass substrate) on the observer side of the plasma display via the adhesive layer 2 described above. In the present invention, the pressure-sensitive adhesive layer 2 is made of the above-mentioned pressure-sensitive adhesive composition, so that when the bonding position is shifted, once the composite filter is peeled from the glass substrate, no adhesive residue occurs on the glass substrate, Since it is excellent in releasability and reworkability, the glass substrate can be reused.

<Preparation of pressure-sensitive adhesive composition>
The following six types of pressure-sensitive adhesives were prepared.

Example 1
To 100 parts by mass of acrylic pressure-sensitive adhesive (trade name: Sanbinol OC3949, solid content: 19.5%, manufactured by Seiden Chemical Co., Ltd.), curing agent (trade name: K-130, solid content: 80%, Seiden Chemical Co., Ltd.) 0.41 part by mass, 0.32 part by mass of a silane coupling agent (trade name: S-1, solid content: 6.3%, manufactured by Seiden Chemical Co., Ltd.), and diluted with 25 parts by mass of toluene. And sufficiently dispersed to prepare a coating solution for forming an adhesive layer.

Example 2
The curing agent (trade name: K-130, solid content: 80%, Seiden Chemical Co., Ltd.) with respect to 100 parts by mass of the acrylic pressure-sensitive adhesive (trade name: Cybinol OC3949, solid content: 19.5%, manufactured by Seiden Chemical Co., Ltd.) 0.41 part by mass, silane coupling agent (trade name: S-1, solid content: 6.3%, manufactured by Seiden Chemical Co., Ltd.) 0.32 part by mass, ultraviolet absorber (trade name: TINUVIN 109) , Solid content: 100%, manufactured by BASF Japan Ltd.), 25 parts by mass of toluene, diluted with 25 parts by mass of toluene, and sufficiently dispersed to prepare a coating solution for forming an adhesive layer.

Example 3
The curing agent (trade name: K-130, solid content: 80%, Seiden Chemical Co., Ltd.) with respect to 100 parts by mass of the acrylic pressure-sensitive adhesive (trade name: Cybinol OC3949, solid content: 19.5%, manufactured by Seiden Chemical Co., Ltd.) 0.41 part by mass, silane coupling agent (trade name: S-1, solid content: 6.3%, manufactured by Seiden Chemical Co., Ltd.) 0.32 part by mass, ultraviolet absorber (trade name: TINUVIN 109) , Solid content: 100%, manufactured by BASF Japan Ltd.), 75 parts by mass, diluted with 25 parts by mass of toluene, and sufficiently dispersed to prepare a coating solution for forming an adhesive layer.

Comparative Example 1
For 100 parts by mass of acrylic pressure-sensitive adhesive (trade name: SK Dyne 2094, solid content: 25%, manufactured by Soken Chemical Co., Ltd.), a curing agent (trade name: E-5XM, solid content: 5%, manufactured by Soken Chemical Co., Ltd.) ) Was mixed with 0.054 parts by mass, diluted with 25 parts by mass of toluene, and sufficiently dispersed to prepare a coating solution for forming an adhesive layer.

Comparative Example 2
Curing agent (trade name: K-200, solid content: 1%, Seiden Chemical Co., Ltd.) with respect to 100 parts by mass of acrylic pressure-sensitive adhesive (trade name: Cybinol ATR-340, solid content: 42%, manufactured by Seiden Chemical Co., Ltd.) Product) 2.38 parts by mass, silane coupling agent (trade name: M-2, solid content: 0.25%, manufactured by Seiden Chemical Co., Ltd.) 0.60 parts by mass, and diluted with 25 parts by mass of toluene. And sufficiently dispersed to prepare a coating solution for forming an adhesive layer.

Comparative Example 3
The curing agent (trade name: K-130, solid content: 80%, Seiden Chemical Co., Ltd.) with respect to 100 parts by mass of the acrylic pressure-sensitive adhesive (trade name: Cybinol OC3949, solid content: 19.5%, manufactured by Seiden Chemical Co., Ltd.) 0.41 part by mass, silane coupling agent (trade name: S-1, solid content: 6.3%, manufactured by Seiden Chemical Co., Ltd.) 0.32 part by mass, ultraviolet absorber (trade name: TINUVIN 109) , Solid content: 100%, manufactured by BASF Japan Ltd.) was mixed with 100 parts by weight, diluted with 25 parts by weight of toluene, and sufficiently dispersed to prepare a coating solution for forming an adhesive layer.

Easy adhesion of biaxially stretched polyethylene terephthalate film (PET film, trade name: Cosmo Shine A4100, film thickness: 100 μm, total light transmittance: 92%, manufactured by Toyobo Co., Ltd.) After coating on the surface side so as to have a film thickness of 25 g / m ² (when dried) and sufficiently drying, a release film (PET separator, trade name: Therapy BX9A (RX), film thickness: 38 μm, Toray Film Processing Co., Ltd.) was laminated to obtain an adhesive sheet. Furthermore, a glass plate having a thickness of 10 mm (PD200, manufactured by Asahi Glass Co., Ltd.) was cut out to a length of 150 mm and a width of 25 mm, and the surface was degreased so that the coating layer of the adhesive composition faced the glass plate side. Using a tensile tester, the glass plate and the biaxially stretched polyethylene terephthalate film were pulled in an atmosphere of 20 to 25 ° C. at a pulling speed of 300 mm / min in a direction where the angle between them was 180 °. The tensile strength at the time of peeling was measured.

Moreover, 25 g / m < ² > (at the time of drying) the prepared said adhesive on the peeling process surface side of a peeling film (PET separator, brand name: Therapy BX9A (RX), film thickness: 38 micrometers, Toray Film Processing Co., Ltd. product) After coating and drying sufficiently, a release film (PET separator, trade name: Therapeutic MFA (RX), film thickness: 38 μm, manufactured by Toray Film Processing Co., Ltd.) is laminated, and an adhesive sheet Got. The coating layer of each pressure-sensitive adhesive is peeled off from the separator so that only the coating layer is formed, and this is rolled into a roll shape and is gripped with a chuck of a tensile tester, and 20-25 at a tensile speed of 100 mm / min. The stress at break when a tensile test was performed in an atmosphere of ° C. was measured. The measurement results were as shown in Table 1 below.

<Production of composite filter>
First, as a metal foil to be a conductive mesh layer, a continuous strip-shaped electrolytic copper foil having a thickness of 10 μm in which a blackening layer made of copper-cobalt alloy particles was formed on one surface by electrolytic plating was prepared. After galvanizing, both sides of this copper foil were subjected to a known chromate treatment by a dipping method to form rust preventive layers on both front and back surfaces. In addition, a continuous strip-shaped uncolored transparent biaxially stretched polyethylene terephthalate film having a thickness of 100 μm and a polyester resin primer layer formed on one surface was prepared as a transparent resin substrate.

  Next, the copper foil is composed of 12 parts by mass of a polyester polyurethane polyol having an average molecular weight of 30,000 on the transparent resin substrate primer layer on the blackened layer surface side, and the curing agent is 1 part by mass of a xylene diisocyanate prepolymer. After being dry-laminated with a transparent two-component curable urethane resin adhesive, the film is cured at 50 ° C. for 3 days to form a 7 μm thick transparent adhesive layer between the copper foil (rust-proof layer) and the transparent resin substrate. A continuous strip-shaped electromagnetic wave shielding sheet was obtained.

  Next, the conductive layer, the blackened layer, and the rust preventive layer are etched on the continuous band-shaped electromagnetic wave shielding sheet by using a photolithographic method to form a frame-like mesh on the outer edge of the mesh-like region and the mesh-like region. A conductive mesh layer having an unformed grounding region was formed. Specifically, the etching was performed consistently from masking to etching using a production line for a color TV shadow mask. That is, a photosensitive etching resist is applied to the entire surface of the conductor layer, and then a desired mesh pattern is closely exposed, developed, hardened, baked to process the resist layer, and then conductive with ferric chloride aqueous solution. The body layer and the blackened layer were removed by etching to form a mesh-shaped opening, and then washing with water, stripping of the resist, washing, and drying were sequentially performed.

On the electroconductive mesh layer of the obtained electromagnetic wave shielding sheet, the above-mentioned pressure-sensitive adhesive was applied so as to have a film thickness of 25 g / m ² (when dried) to form a pressure-sensitive adhesive layer to obtain a composite filter.

<Adhesion evaluation>
A composite filter processed to a length of 150 mm and a width of 25 mm was attached to a glass substrate for PDP (PD200, manufactured by Asahi Glass Co., Ltd.) via an adhesive layer. Using a tensile tester, the glass substrate and the composite filter were pulled in an atmosphere of 20 to 25 ° C. in a direction where the angle between the glass substrate and the composite filter was 180 ° at a pulling speed of 300 mm / min, and the sticking force was measured. The measurement results were as shown in Table 2 below.

<Evaluation of reworkability>
The composite filter was peeled from the glass substrate for PDP, and the presence or absence of the adhesive layer remaining on the glass substrate was examined visually. Reworkability was evaluated according to the following criteria.
○: No adhesive remains on the glass substrate.
Δ: No adhesive remains on the glass substrate, but the sticking force is less than 1.0 N / 25 mm or more than 15.0 N / 25 mm.
X: A sticky substance remains on the glass substrate, and the sticky layer is cohesively broken.

The evaluation results were as shown in Table 1 below.

DESCRIPTION OF SYMBOLS 1 Composite filter 2 Adhesive layer 3 Electromagnetic wave shielding / optical filter 4 Electromagnetic wave shielding filter 5 Optical filter 6, 7 Separator 8 Adhesive layer 9 PDP front glass substrate

Claims (10)

A pressure-sensitive adhesive composition for adhering a glass substrate disposed on the front surface of a panel of a plasma display and a composite filter provided on the front surface of the glass substrate,
A pressure-sensitive adhesive composition having a peel strength of 1.0 to 15.0 N / 25 mm with respect to a glass substrate and a stress at break of 0.15 to 3.0 MPa. When the peel strength is P (N / 25 mm) and the stress at break is S (MPa), S / P is 0.07 to 0.26 (2.5 × 10 ² · m ⁻¹ ). The pressure-sensitive adhesive composition according to claim 1, wherein:   The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the glass substrate is soda lime glass or high strain point glass having a thickness of 1 to 5 mm and a thickness deviation of 15 µm or less.   The pressure-sensitive adhesive composition according to any one of claims 1 to 3, wherein the pressure-sensitive adhesive is an acrylic resin-based pressure-sensitive adhesive. A storage modulus at 25 ° C. is ^{1.3 × 10 5 Pa~4.0 × 10 5} Pa, the pressure-sensitive adhesive composition according to any one of claims 1-4. The adhesive composition as described in any one of Claims 1-5 whose loss elastic modulus in 25 degreeC is 7.9 * 10 < ³ > Pa-1.8 * 10 < ⁵ > Pa.   The pressure-sensitive adhesive according to any one of claims 1 to 6, comprising at least one absorber selected from the group consisting of a far-infrared absorber, a neon light absorber, an ultraviolet absorber, and a color tone adjusting dye. Agent composition.   The composite filter in which the adhesion layer which consists of an adhesive composition as described in any one of Claims 1-7 was provided in one surface.   At least one selected from the group consisting of an electromagnetic wave shielding function, a near infrared shielding function, a neon light shielding function, an ultraviolet shielding function, an antireflection function, an antiglare function, an anti-scratch function, an antifouling function, and an antistatic function The composite filter according to claim 8, comprising a function.   A plasma display in which the composite filter according to claim 8 or 9 is adhered to the front surface of a glass substrate.

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