JP2007094191A - Impact absorbing material for flat display, optical filter for plasma display, plasma display panel, and method of manufacturing impact absorbing material for flat display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impact absorbing material for a flat display which can be stuck directly on a front glass of the flat display, the impact absorbing material which is hardly peeled after being stuck, hardly swells, hardly falls and so on, enables the flat display to be recycled after being peeled, and can make manufacturing step simple and low-cost as a high-impact material and to provide an optical filter for a plasma display which uses the impact absorbing material. <P>SOLUTION: Disclosed are the impact absorbing material for the flat display which is a single layer of ≥100 μm in thickness and 3 to 15 N/25 mm in glass adhesive strength, and the optical filter for the plasma display including an impact resistant layer made of the impact absorbing material. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a shock-absorbing material for flat display, an optical filter for plasma display, a plasma display panel, and a method for producing a shock-absorbing material for flat display.

  In recent years, flat displays such as PDP (Plasma Display Panel), FED (Field Emission Display), and LCD (Liquid Crystal Display) capable of producing a large screen panel have attracted attention as display panels of various electronic devices. Such a flat display has a problem that the front glass of the display is thin and easily broken as the size of the flat display increases.

  Conventionally, in order to prevent damage to the front glass of a flat display such as a PDP, a protective plate made of acrylic resin or tempered glass is provided in front of the front glass at intervals of several millimeters, and an impact is applied to the flat display panel. It was preventing that. However, such a protective structure has a problem that obstructs the weight reduction and thickness reduction of the flat display panel. Furthermore, since there is a space between the front glass of the panel and the protective plate, there is a problem that image quality is deteriorated due to reflection of external light such as a fluorescent lamp, and image distortion is caused by slight vibration.

Accordingly, various techniques for directly attaching a protective plate or the like to the front glass have been studied as techniques for preventing the front glass of the flat display panel from being damaged. For example, Patent Document 1 proposes a structure in which a protective plate is bonded to the front glass of the panel through an adhesive layer. However, in this structure, the impact is easily transmitted to the front glass, and the front glass is sufficiently prevented from being damaged. There was a problem that could not be obtained. As another technique, Patent Document 2 discloses that a crack prevention layer (impact mitigation layer) B and a scattering prevention layer A thereon are transparent in this order via a transparent adhesive layer on the front glass of a flat display panel. Two layers made of synthetic resin are laminated, the scattering elastic layer A has a shear elastic modulus of 2 × 10 ⁸ Pa or more, and the anti-cracking layer B has a shear elastic modulus of 1 × 10 ⁴ to 2 × 10 ⁸ Pa. An impact relaxation laminate has been proposed. Patent Document 3 discloses an impact resistant film that is bonded to the front glass of a flat display panel body, and is made of a transparent synthetic resin having a shear modulus of 1 × 10 ³ Pa to 1 × 10 ⁶ Pa. A first layer on the front glass side of the display panel, a second synthetic layer made of a transparent synthetic resin having a shear modulus of 1 × 10 ⁸ Pa or more, and a shear layer having a shear modulus that is closer to the viewing side than the first layer. An impact-resistant film for a flat display panel, comprising a transparent synthetic resin of 1 × 10 ⁶ Pa or more and less than 1 × 10 ⁸ Pa and including a third layer on the visual recognition side with respect to the second layer. Proposed. However, according to these laminates, there are problems that the film thickness increases due to the increase in layers, the manufacturing process becomes complicated, and the cost increases.

  Patent Document 4 discloses a plasma display panel in which an optical filter having an antireflection film is attached to the front surface of a display via an adhesive layer, and the destruction energy by an impact test is 0.5 joules or more. A panel is proposed, and the thickness of the pressure-sensitive adhesive layer is described as 0.5 to 2.0 mm.

JP 2000-156182 A JP 2001-266759 A JP 2003-246015 A JP 2002-260539 A

  When a protective plate or the like is directly attached to the front glass, the protective plate or the like may be wrinkled or dust may enter between the front glass and the protective plate in the step of directly attaching. In such a case, there is a demand for removing the protective plate and reusing the flat display. However, it is difficult to peel off the protective plate or the like, and even if it is peeled off, a part of the adhesive remains on the front glass (hereinafter sometimes referred to as “glue residue”), and it has been difficult to reuse the flat display. For example, according to the pressure-sensitive adhesive layer disclosed in the example of Patent Document 4 described above, as shown in a comparative example described later, the adhesion strength is too strong and it is difficult for a person to pull and peel.

  The present invention has been made in consideration of the above-described problems, and is an impact resistant material that can be directly bonded to the front glass of a flat display, and peels off, swells, or falls off after bonding. It is difficult to recycle the flat display after peeling, and the shock-absorbing material for flat display that can simplify the manufacturing process and reduce the cost, the optical filter for plasma display using the shock-absorbing material, and the optical An object of the present invention is to provide a plasma display panel using a filter and a method for producing a shock-absorbing material for flat displays.

The present invention has been made to solve the above-mentioned problems by providing a shock-absorbing material for flat displays having a single layer thickness of 100 μm or more and a glass adhesion of 3 to 15 N / 25 mm.
The shock-absorbing material for flat display according to the present invention is a single layer having a thickness of 100 μm or more and a glass adhesion of 3 to 15 N / 25 mm. It is possible to peel off, swell, and slip off during use after bonding. On the other hand, since peeling is easy after bonding, the flat display after peeling can be reused. In addition, since it is a single layer, there is no increase in thickness due to an increase in the number of layers such as a laminate, and the manufacturing process is not complicated, so that the manufacturing process can be simplified and the cost can be reduced.

In the shock-absorbing material for flat display according to the present invention, the tensile elastic modulus is preferably 1 × 10 ⁴ to 1 × 10 ⁶ Pa · s at 25 ° C. from the viewpoint of shock absorption.

  Further, in the impact-resistant absorbent for flat display according to the present invention, it is preferable that the component having a molecular weight of 1000 or less is 3% by weight or less from the point of no adhesive residue at the time of peeling after bonding and the point of smell. .

  In the shock-absorbing material for flat display according to the present invention, the acrylic adhesive contains durability such as heat resistance, moist heat resistance, and light resistance, transparency, and low cost (high versatility. ) And high productivity in realizing the present invention.

  In addition, as the acrylic pressure-sensitive adhesive, at least one selected from the group consisting of 2-ethylhexyl (meth) acrylate, n-butyl (meth) acrylate, and lauryl (meth) acrylate is used. A polymerized polymer is preferable from the viewpoint of transparency and low cost.

  In the shock-absorbing material for flat display according to the present invention, the tackifier is less than 3% by weight, there is no adhesive residue at the time of peeling after bonding, transparency, and adhesiveness over time. It is preferable from the viewpoint that deterioration does not easily occur.

  The optical filter according to the present invention is an optical filter for being directly attached to a display surface of a plasma display panel, and includes an impact resistant layer made of the impact resistant absorbent material according to the present invention. To do.

  The optical filter according to the present invention includes a shock-resistant layer made of the shock-absorbing material according to the present invention, so that it has a good impact resistance with respect to the display surface. Compared with the optical filter which has, it can achieve considerable weight reduction and cost reduction.

  In the optical filter according to the present invention, it is preferable that the layer constituting the surface directly attached to the optical filter is an impact resistant layer made of the impact resistant absorbent material according to the present invention. In this case, the plasma display panel after peeling can be reused because it is easy to peel off while having adhesiveness with no problem in use on the display surface. In addition, the layer structure can be simplified and the manufacturing process can be simplified and the cost can be reduced as compared with the optical filter that is directly attached to the display surface of the conventional plasma display panel.

  In the optical filter for plasma display according to the present invention, it has a resin layer containing a near-infrared absorbing compound, and the transmittance in the wavelength range of 800 to 1100 nm is 40% or less. This is preferable from the viewpoint of blocking near-infrared rays that can cause malfunction of the device.

  Further, the optical filter for plasma display according to the present invention has a resin layer containing a neon light absorbing compound having a maximum absorption wavelength in the wavelength range of neon light 560 to 630 nm, and the transmittance of the maximum absorption wavelength in the wavelength range. Is preferably 30% or less from the viewpoint of blocking neon light emitted from the inside of the display and affecting the color tone.

  In the optical filter for plasma display according to the present invention, the transmittance in the wavelength range of 380 to 780 nm of visible light is preferably 40% or more from the viewpoint of obtaining a highly transparent optical filter.

  Further, in the optical filter for plasma display according to the present invention, having an electromagnetic wave shielding layer that shields static electricity and / or electromagnetic noise generated from the plasma display device reduces the intensity of electromagnetic wave emission to within the standard. It is preferable from the point.

Moreover, the plasma display panel according to the present invention is obtained by directly pasting the optical filter according to the present invention on a display surface.
In the plasma display panel according to the present invention, since the optical filter according to the present invention is directly attached to the display surface, there is no space between the front glass of the panel and the protective plate, thereby degrading the image quality and distorting the image. In addition, there is no problem of causing a reduction in weight, and a reduction in weight and thickness can be realized. Further, the manufacturing process can be simplified and the cost can be reduced.

Further, the method for producing a shock-absorbing material for flat display according to the present invention comprises a solvent-free coating material for forming a shock-absorbing material containing at least one photopolymerizable monomer and a polymer of the photopolymerizable monomer. applying the irradiation a coating step, and a weak irradiation step of irradiating the 20 to 180 seconds UV at 1 mW / cm ² or more 40 mW / cm ² below the illuminance, 0.1 and 20 seconds UV at 40 mW / cm ² or more illumination And a strong irradiation process. The method for producing a shock-absorbing material for flat display according to the present invention is a method suitable for obtaining the shock-absorbing material for flat display according to the present invention.
In the method for manufacturing a shock-absorbing material for flat display according to the present invention, the shock-absorbing material for flat display according to the present invention is such that the coating liquid for forming the shock-absorbing material is an acrylic adhesive. In order to obtain, it is preferable from a point of high productivity.

  The shock-absorbing material for flat display according to the present invention is an impact-resistant material that can be directly bonded to the front glass of the flat display, and is difficult to peel off, swell, slip off after bonding, and flat after peeling. The display can be reused, and the manufacturing process can be simplified and the cost can be reduced.

  The optical filter according to the present invention includes a shock-resistant layer made of the shock-absorbing material according to the present invention, so that it has a good impact resistance with respect to the display surface. Compared with the optical filter which has, it can achieve considerable weight reduction and cost reduction. In the optical filter according to the present invention, in particular, when the layer constituting the surface to which the optical filter is directly attached is the shock-absorbing material according to the present invention, the adhesive having no problem in use with respect to the display surface Since it is easy to peel off, the plasma display panel after peeling can be reused. In addition, the layer structure can be simplified and the manufacturing process can be simplified and the cost can be reduced as compared with the optical filter that is directly attached to the display surface of the conventional plasma display panel.

  The plasma display panel according to the present invention does not have a problem of image quality degradation or image distortion while having impact resistance, and can be reduced in weight and thickness. Further, the manufacturing process can be simplified and the cost can be reduced. Can be achieved.

  Moreover, according to the manufacturing method of the shock-resistant absorber for flat displays which concerns on this invention, productivity is high in obtaining the shock-resistant absorber for flat displays which concerns on the said this invention.

  The present invention includes a shock-absorbing material for flat displays, an optical filter using the same, a plasma display panel, and a method for producing a shock-absorbing material for flat displays. Each will be described in detail below.

A. Shock-resistant absorbent material for flat display The shock-resistant absorbent material for flat display according to the present invention is a single layer having a thickness of 100 μm or more and a glass adhesion of 3 to 15 N / 25 mm.
Here, the glass adhesion can be measured by bonding to sodium soda glass and peeling at 90 ° at a speed of 200 mm / min in accordance with the test of JIS Z0237-2000. If the glass adhesion is less than 3 N / 25 mm, the glass may peel off from the front glass of the flat display, bubbles may form over time, or partial peeling may occur. Also, if the glass adhesion exceeds 15 N / 25 mm, it is difficult to peel off even if a person pulls it after attaching to a glass surface such as a 42-inch size. It is difficult to peel off the absorbent material and reuse the flat display. The glass adhesion is more preferably 5 to 12 N / 25 mm.

  The shock-absorbing material for flat display according to the present invention has a single layer thickness of 100 μm or more and a glass adhesion of 3 to 15 N / 25 mm, so that it can be directly bonded to the front glass of the flat display. Even if there is, it absorbs and prevents the glass from breaking. In addition, peeling, swelling, slipping, and the like during use are less likely to occur after bonding, and the flat display after peeling can be reused because peeling is easy after bonding. In addition, since it is a single layer, there is no increase in thickness due to an increase in the number of layers such as a laminate, and the manufacturing process is not complicated, so that the manufacturing process can be simplified and the cost can be reduced.

The shock-absorbing material according to the present invention is a single layer when used as a shock-absorbing material, but at the time of distribution, a release film such as PET coated with a silicone resin or a fluorine-based resin is used. It may be affixed on both sides or one side of the layer.
The shock-resistant absorbent for flat display according to the present invention is a single layer and has a thickness of 100 μm or more from the viewpoint of shock absorption, but is preferably 1500 μm or less from the viewpoint of preventing thickening, From the standpoint of prevention of thickening, it is more preferable that the thickness is 500 μm to 1000 μm.

In the impact-resistant absorbent for flat display according to the present invention, the tensile elastic modulus is preferably 1 × 10 ⁴ to 1 × 10 ⁶ Pa · s at 25 ° C. from the viewpoint of impact absorption, and further 5 × 10 ^{4 to} 5 ×. It is preferably 10 ⁵ Pa · s. Here, the tensile elastic modulus refers to the mean square value of the viscosity term and the elastic term in the dynamic viscoelasticity measurement. The value of the tensile modulus can be measured using a dynamic viscoelasticity measuring device (Rheogel-E4000, manufactured by UBM Co., Ltd.), 25 ° C., distance between chucks 20 mm, width 5 mm, strain 10 μm, ascending. It is a value at a temperature rate of 2 ° C./min and a frequency of 10 Hz.

  The shock-absorbing material for flat display according to the present invention is appropriately selected from resin materials having adhesiveness that can satisfy a single layer thickness of 100 μm or more and glass adhesion of 3 to 15 N / 25 mm. Can be used. Examples of the resin material having adhesiveness include silicone resin, urethane resin, epoxy resin, polyester resin, and acrylic resin. Among them, it is possible to include an acrylic resin having adhesiveness (hereinafter referred to as an acrylic adhesive), durability such as heat resistance, moist heat resistance, and light resistance, transparency, and low cost (high versatility. ) And high productivity in realizing the present invention.

  The acrylic pressure-sensitive adhesive is a main component of adhesion, and is usually 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. It is common that. In the present invention, (meth) acrylic acid refers to acrylic acid and / or methacrylic acid.

  Examples of (meth) acrylic acid alkyl ester monomers used here include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, sec-propyl (meth) acrylate, N-butyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, Examples thereof include n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, undecyl (meth) acrylate, and lauryl (meth) acrylate. Among these, 2-ethylhexyl (meth) acrylate, n-butyl (meth) acrylate, and lauryl (meth) acrylate are preferably used in terms of transparency and low cost. The (meth) acrylic acid alkyl ester is usually copolymerized in an amount of 15 to 99.5 parts by weight in the acrylic pressure-sensitive adhesive, but in the acrylic pressure-sensitive adhesive used in the present invention, it is 15 to 80. More preferably, it is copolymerized in an amount of parts by weight.

  Moreover, as a monomer which has a carboxyl group which forms an acrylic adhesive, monomers containing a carboxyl group such as (meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, monobutyl maleate and β-carboxyethyl acrylate are used. Can be mentioned.

  Furthermore, it is preferable to contain a monomer having an alkoxyalkyl chain in addition to the monomer as described above from the viewpoint of high heat and humidity resistance. Examples of alkoxyalkyl esters of (meth) acrylic acid include 2-methoxyethyl (meth) acrylate, methoxyethyl (meth) acrylate, 2-methoxypropyl (meth) acrylate, 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.

  Furthermore, in addition to the above, the acrylic pressure-sensitive adhesive used in the present invention may be copolymerized with a monomer having another functional group within a range that does not impair the characteristics of the acrylic 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 monomers containing amino groups such as (meth) acrylate, dimethylaminoethyl (meth) acrylate and vinylpyridine; epoxy group-containing monomers such as allyl glycidyl ether and (meth) acrylic acid glycidyl ether Can be mentioned. In addition to these, 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.

  Furthermore, in the acrylic pressure-sensitive adhesive used in the present invention, in addition to the monomer having other functional groups 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 ether; vinyl aromatic compounds such as styrene, α-methylstyrene and vinyl toluene; (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.

  In the impact-absorbing material for flat display according to the present invention, in order to improve impact resistance, a cross-linking agent may be added in addition to the adhesive resin material. The cross-linking agent causes a cross-linking reaction by light or heat, and the shock-absorbing material includes a reaction product after the cross-linking reaction. Examples of the crosslinking agent include isocyanates such as tridiisocyanate, epoxy curing agents, polyfunctional monomers, etc. (polyfunctional is bifunctional or higher). Among these, it is preferable to use a crosslinking agent such as tolylene diisocyanate that can react with a carboxyl group contained in the acrylic pressure-sensitive adhesive from the viewpoints of improving impact resistance and heat resistance and light resistance. When adding a crosslinking agent, it is preferable to add 0.1 to 3 weight% in the shock-absorbing material for flat displays.

  In the impact-absorbing material for flat display according to the present invention, it is preferable that the component having a molecular weight of 1000 or less is 3% by weight or less from the point of no adhesive residue at the time of peeling after bonding and the smell. Furthermore, the component having a molecular weight of 1000 or less is desirably 1% by weight or less, preferably 0.5% by weight or less from the viewpoint of odor.

  Moreover, in the shock-absorbing material for flat displays according to the present invention, the tackifier (also referred to as “tackifier”) is preferably less than 3% by weight. In such a case, there is no adhesive residue at the time of peeling after bonding, and transparency is not deteriorated from the viewpoint of compatibility with the adhesive resin contained in the shock-absorbing material. Moreover, it is because a shift | offset | difference, a bubble, and peeling do not occur easily by a tackifier moving to an interface with time. In the impact-resistant absorbent for flat display according to the present invention, the tackifier is more preferably less than 1% by weight, and still more preferably not contained.

  The shock-resistant absorbent material for flat display according to the present invention is preferably highly transparent because it is attached to the display surface of the display, and preferably has a haze of 3 or less. Here, haze means a value measured by a method according to JIS K7105-1981. Specifically, an adhesive resin layer is bonded to a glass plate having a thickness of 1.2 mm, and an easy adhesion surface of a PET film, for example, Cosmo Shine A-4100 manufactured by Toyobo, is overlapped with the adhesive resin layer on the opposite side of the glass plate. The haze value can be measured using a sample prepared by bonding.

  It is desirable that the shock-resistant absorbent material for flat display according to the present invention has an impact resistance of 0.5 J or more, preferably 0.6 J or more, as a result of an impact test with respect to a plasma display panel. Here, the impact test is performed using an impact test apparatus shown in FIG. 6, and a steel ball 35 (weight 534 g) having a diameter of 9.6 cm to a diameter of 50.8 mm (specified in the steel ball for JIS B1501 ball bearing). This was done by measuring the breaking energy when the was dropped. As the test stand 31, a SUS base 32 and a glass plate 33 having a thickness of 10 mm bonded together were used. On the test bench 31, a high strain point glass plate (PD-200: trade name, thickness 2.8 mm) manufactured by Asahi Glass Co., Ltd. was placed as a front glass plate 34 for plasma display. PD-200 is a front glass plate 34 for plasma display that is commonly used by plasma display manufacturers. The reason for placing the front glass plate 34 directly on the test table 31 is to eliminate the cushioning property of the casing of the plasma display.

  The impact-resistant absorbent for flat display according to the present invention may further contain a sensitizer such as n-butylamine, a photopolymerization initiator and the like as long as the effects of the present invention are not impaired. Moreover, it is good also as what has 1 or more types of pigment | dyes, such as the near-infrared absorption pigment | dye and / or neon light absorption pigment | dye which are mentioned later, and also has a near-infrared and / or neon light absorption function and a color correction function. .

  The shock-absorbing material for flat display according to the present invention is suitable for being incorporated into a flat display and the manner of incorporation is not limited at times, but among them, the shock-absorbing material used by being directly attached to a flat display panel. Especially suitable for materials.

B. Method for producing shock-absorbing material for flat display The method for producing a shock-absorbing material for flat display according to the present invention is solvent-free and contains at least one photopolymerizable monomer and a polymer of the photopolymerizable monomer. a coating step of applying the shock absorber forming coating liquid, a weak irradiation step of irradiating the 20 to 180 seconds UV at 1 mW / cm ² or more 40 mW / cm ² below the illuminance, 0 40 mW / cm ² or more illumination A strong irradiation step of irradiating ultraviolet rays for 1 to 20 seconds.

The manufacturing method of the impact-absorbing material for a flat display according to the present invention will be specifically described with reference to the drawings. FIG. 1 is a process diagram showing an example of a method for producing a shock-resistant absorbent material for flat displays according to the present invention. As shown in FIG. 1 (a), first, a shock-absorbing material-forming coating solution containing no solvent and at least one photopolymerizable monomer and a polymer of the photopolymerizable monomer on the release film 1 is used. The application | coating process which apply | coats 2 is performed. Next, as shown in FIG. 1 (b), the impact-absorbing material-forming coating solution 2 applied by the application step is applied for 20 to 180 seconds at an illuminance of 1 mW / cm ² or more and less than 40 mW / cm ^2. The weak irradiation process of irradiating the weak ultraviolet rays 3 is performed. As a result, at least one photopolymerizable monomer contained in the coating liquid 2 slowly undergoes a polymerization reaction to form a large amount of a polymer having a high molecular weight in a straight chain, and the impact resistance has increased. The absorbent material-forming coating film 4 is formed. Next, as shown in FIG. 1 (c), the ultraviolet ray 5 is further applied to the layer 4 of the impact-resistant absorber-forming coating film 4 that has been polymerized at an illuminance of 40 mW / cm ² or more for 0.1 to 20 seconds. By performing the intense irradiation process to irradiate, the impact-resistant absorber 6 is formed as shown in FIG. By this intense irradiation process, the photopolymerizable monomer remaining in the impact-resistant absorbent-forming coating film 4 undergoes a polymerization reaction, and the residual monomer is reduced.

  The manufacturing method of the shock-absorbing material for flat display according to the present invention as described above is a manufacturing method suitable for obtaining the shock-absorbing material for flat display according to the present invention. The impact-resistant absorbent for flat display according to the present invention is not particularly limited as long as a predetermined physical property value is obtained, but since it is a single layer and a relatively thick film, for example, a coating solution containing a solvent The production of a large amount of solvent generates a large amount of solvent, and the recovery apparatus is costly. Further, it takes time for drying, and bubbles are easily formed during drying, resulting in poor productivity. On the other hand, in the manufacturing method according to the present invention, since the solventless coating liquid is applied for manufacturing, the above problem is solved.

  In addition, according to the method for producing a shock-absorbing material for flat display of the present invention as described above, since it has both a weak irradiation process and a strong irradiation process, the amount of residual monomer is reduced and it is directly attached to the glass surface. It is possible to easily produce an impact-resistant absorbent material that has no adhesive residue even if it is peeled later.

Hereinafter, the manufacturing method of the impact-resistant absorber for flat displays of this invention is demonstrated for every process.
1. Application Step The application step in the present invention is a step of applying a shock-absorbing material-forming coating solution that is solventless and contains at least one photopolymerizable monomer and a polymer of the photopolymerizable monomer.
The impact-absorbing material-forming coating solution used in the present invention does not contain a solvent, and contains at least one photopolymerizable monomer and a polymer of the photopolymerizable monomer. Other additives are added. Specific examples of such additives include a photopolymerization initiator, a sensitizer, and a crosslinking agent. In addition, in order to obtain a shock-absorbing material having a near-infrared and / or neon light absorption function and a color correction function as described above, a near-infrared absorption dye and / or a neon light absorption dye as described later are used. One or more dyes may be contained.

The coating liquid used in the present invention, which does not contain a solvent and contains at least one photopolymerizable monomer and a polymer of the photopolymerizable monomer, contains at least one photopolymerizable monomer. This is a so-called syrup-type coating solution in which a monomer polymer is dissolved. As such a syrup-type coating liquid, an acrylic syrup-type coating containing at least a (meth) acrylic acid alkyl ester monomer having an alkyl group, a monomer having a carboxyl group, and a copolymer thereof. A liquid is preferred. The alkyl group-containing (meth) acrylic acid alkyl ester monomer, the carboxyl group-containing monomer, and the copolymerizable monomer used in the acrylic syrup-type coating liquid are specifically the same as described above. Can be used.
The syrup-type coating liquid can be obtained, for example, by adding a polymerization initiator to at least one photopolymerizable monomer to advance the polymerization reaction, and performing forced cooling to stop the polymerization reaction halfway.

  The coating liquid used in the present invention is preferably adjusted to a viscosity that can be applied, and is preferably adjusted to about 500 to 20000 mPa · s, more preferably about 1000 to 5000 mPa · s.

  Further, in the coating liquid used in the present invention, the total content of the polymer with respect to the total weight of the polymer of at least one photopolymerizable monomer and the photopolymerizable monomer is not particularly limited. However, it is usually about 20 to 60% by weight, preferably about 40 to 50% by weight.

The coating method in this step is not particularly limited as long as it is a method capable of uniformly coating the coating liquid. Bar coating, blade coating, spin coating, die coating, slit reverse coating, three reverse coating Methods such as comma coating, roll coating, and dip coating can be used. In the present invention, among them, it is preferable to use die coating, slit reverse coating, three reverse coating, and comma coating, which are easy to apply a relatively thick film.
The thickness of the coating is preferably 100 μm to 1500 μm, and more preferably 500 μm to 1000 μm.

  Further, in the method for producing a shock-absorbing material for flat display according to the present invention, a release film is further applied on the coating liquid layer after the coating, preferably before the weak irradiation step. You may have the process to match. In this case, it is easy to flatten the coating liquid and hardly cause oxygen inhibition. Moreover, it is because it is easy to perform when performing the weak irradiation process and strong irradiation process which are mentioned later about both surfaces of a coating film. As the release film, it is preferable to use a film that is easy to peel off and has high transparency so as not to disturb the irradiation in the irradiation process described later. For example, PET coated with a silicone resin or a fluorine-based resin is preferable. Used.

2. Weak irradiation step and strong irradiation step In the present invention, after the coating step, the photopolymerizable monomer contained in the coating liquid for forming the retardation enhancement region applied in the coating step is polymerized to be polymerized. to strength radiation for irradiating a weak irradiation step of irradiating the 20 to 180 seconds UV at 1 mW / cm ² or more 40 mW / cm ² below the illuminance, 0.1 and 20 seconds UV at 40 mW / cm ² or more illumination A process is performed.
Photopolymerization contained in the coating by suppressing the radical generation amount of the photopolymerization initiator by the weak irradiation process of irradiating ultraviolet rays for 20 to 180 seconds with a weak illuminance of 1 mW / cm ² or more and less than 40 mW / cm ^2. It is presumed that the chain transfer of the functional monomer can be performed slowly and the polymer can be made into a straight chain. The illuminance in the weak irradiation process is further preferably 1 mW / cm ² or more and 20 mW / cm ² or less, particularly preferably 1 mW / cm ² or more and 10 mW / cm ² or less. Moreover, it is preferable that the irradiation time of a weak irradiation process is 60 to 120 second further. Such a weak irradiation step is preferably performed on the surface of the coating film formed by the coating step directly attached to the glass surface from the viewpoint of eliminating adhesive residue, but further irradiation is performed from one side of the coating film. In addition, it is preferable to irradiate from both sides in terms of impact resistance and durability.

On the other hand, by the strong irradiation process in which ultraviolet rays are irradiated for 0.1 to 20 seconds at an illuminance of 40 mW / cm ² or more, the remaining monomers in the coating film are completely polymerized particularly in the vicinity of the surface even after the weak irradiation process. It is possible to eliminate the residual monomer that causes adhesive residue. Furthermore the illuminance intensity irradiation step over 40 mW / cm ² or more 1200 mW / cm ² or less, and particularly preferably 400 mW / cm ² or more 600 mW / cm ² or less. Moreover, it is preferable that the irradiation time of a strong irradiation process is further 0.1 to 5 second. Such a strong irradiation step is preferably performed on the surface of the coating film formed by the coating step, which is directly attached to the glass surface from the viewpoint of eliminating adhesive residue, but further irradiation is performed from one side of the coating film. In addition, it is preferable to irradiate from both sides in terms of impact resistance and durability.

  When the coating solution contains a crosslinking agent that undergoes crosslinking by heat, it is preferable to have a heating step as appropriate in accordance with the used crosslinking agent after the irradiation step.

C. Optical filter An optical filter according to the present invention is an optical filter for being directly attached to a display surface of a plasma display panel, and includes an impact resistant layer made of the impact resistant absorbent material according to the present invention. To do.
The optical filter according to the present invention includes a shock-resistant layer made of the shock-absorbing material according to the present invention, so that it has a good impact resistance with respect to the display surface. Compared with the optical filter which has, it can achieve considerable weight reduction and cost reduction. In the optical filter according to the present invention, it is preferable that the layer constituting the surface directly attached to the optical filter is an impact resistant layer made of the impact resistant absorbent material according to the present invention. In this case, the plasma display panel after peeling can be reused because it is easy to peel off while having adhesiveness with no problem in use on the display surface. In addition, the layer structure can be simplified and the manufacturing process can be simplified and the cost can be reduced as compared with the optical filter that is directly attached to the display surface of the conventional plasma display panel.

  The optical filter according to the present invention can be constituted by laminating one or more layers having various functions in addition to the impact resistant layer made of the impact resistant absorbent material according to the present invention. Examples of the layer having these functions include an antireflection layer, an electromagnetic wave shielding layer that shields static electricity and / or electromagnetic noise generated from the plasma display device, a near infrared absorption layer made of a resin layer containing a near infrared absorption compound, and neon Examples thereof include a neon light absorption layer made of a resin layer containing a light absorption compound, a color tone correction layer, and an adhesive layer. The functions of these layers may be combined in one layer, for example, a dye-containing pressure-sensitive adhesive layer that has both a neon absorption function and a color tone correction function, a near infrared absorption layer that has both a neon absorption function and a color tone correction function, and a near infrared ray Layers having two or more functions such as an antireflection layer having an absorption function and / or an ultraviolet shielding function, and an electromagnetic wave shielding layer having a near infrared absorption function may be laminated.

  In the optical filter according to the present invention, the layer constituting the surface to which the optical filter is directly attached is preferably an impact resistant layer made of the impact resistant absorbent according to the present invention, and the impact resistant absorbent according to the present invention. It is preferable that one or more layers having various functions are stacked on one surface different from the surface directly attached to the display surface of the two surfaces of the impact resistant layer.

  FIG. 2 is a view showing an example of a laminated structure when the optical filter according to Embodiment 1 of the present invention is attached to the front surface of the plasma display panel. Reference numeral 11 denotes an impact resistant layer made of the impact resistant absorbent material according to the present invention. The electromagnetic wave shielding layer 12 is laminated on the impact resistant layer 11 via the pressure-sensitive adhesive layer 16. The near-infrared absorbing layer 13 is laminated on the electromagnetic wave shielding layer 12 with the adhesive layer 16 interposed therebetween. The antireflection layer 15 is laminated on the near-infrared absorption layer 13 through a dye-containing pressure-sensitive adhesive layer 14 having both a neon absorption function and a color tone correction function. Here, the pressure-sensitive adhesive layer 16 interposed between the electromagnetic wave shielding layer 12 and the near-infrared absorbing layer 13 is also filled in the irregularities of the mesh structure of the electromagnetic wave shielding layer 12 and contributes to flattening on the electromagnetic wave shielding layer 12. is doing. A film (shown by black solid coating) formed by the blackening treatment on the surface of the metal mesh in the electromagnetic wave shielding layer 12 is provided on the impact-resistant layer 11 side (plasma display panel body 10 affixing side). The laminate composed of these layers constitutes the optical filter 17 of the first embodiment. (Hereinafter, the layers having the above-described layer structure are arranged in the order of “impact resistant layer 11 / adhesive layer 16 / electromagnetic wave shielding layer 12 (blackening treatment is on the impact resistant layer 11 side) / adhesive layer 16 / near infrared ray”. Absorbing layer 13 / dye-containing pressure-sensitive adhesive layer 14 / antireflection layer 15 ”.) The optical filter 17 is further applied to the surface (front glass 19) of the plasma display panel body 10 according to the shock resistance according to the present invention. The impact-resistant layer 11 made of an absorbent material is directly attached and bonded.

The dye-containing pressure-sensitive adhesive layer 14 may be replaced with the position of any pressure-sensitive adhesive layer 16 in FIG. 2 and may be in the following mode.
Embodiment 2: Impact resistant layer 11 / Adhesive layer 16 / Electromagnetic wave shielding layer 12 (Blackening treatment is on the impact resistant layer 11 side) / Dye-containing adhesive layer 14 / Near-infrared absorbing layer 13 / Adhesive layer 16 / Antireflection Layer 15
Embodiment 3: Impact resistant layer 11 / dye-containing adhesive layer 14 / electromagnetic wave shielding layer 12 (blackening treatment is on the impact resistant layer 11 side) / adhesive layer 16 / near infrared absorbing layer 13 / adhesive layer 16 / antireflection Layer 15

  FIG. 3 is a view showing an example of a laminated structure when the optical filter according to Embodiment 4 of the present invention is attached to the front surface of the plasma display panel. In the optical filter of FIG. 3, the blackening treatment on the surface of the metal mesh in the electromagnetic wave shielding layer 12 in the optical filter in FIG. In addition, the pressure-sensitive adhesive layer 16 filled in the irregularities of the metal mesh structure of the electromagnetic wave shielding layer 12 is a pressure-sensitive adhesive layer 16 interposed between the impact resistant layer 11 and the electromagnetic wave shielding layer 12. 2 is the same as that of FIG. The dye-containing pressure-sensitive adhesive layer 14 in FIG. 2 may be replaced with the position of any pressure-sensitive adhesive layer 16 in FIG.

Embodiment 5: Impact resistant layer 11 / adhesive layer 16 / electromagnetic wave shielding layer 12 (blackening treatment is on the antireflection layer 15 side) / dye-containing adhesive layer 14 / near infrared absorbing layer 13 / adhesive layer 16 / antireflection Layer 15
Embodiment 6: Impact resistant layer 11 / dye-containing adhesive layer 14 / electromagnetic wave shielding layer 12 (blackening treatment is on the antireflection layer 15 side) / adhesive layer 16 / near infrared absorbing layer 13 / adhesive layer 16 / antireflection Layer 15

  Furthermore, the optical filter according to the present invention only needs to contain an impact resistant layer composed of the impact resistant absorbent material according to the present invention, and the impact resistant layer 11 composed of the impact resistant absorbent material according to the present invention is an optical filter. Instead of the layer constituting the surface to which the filter is directly attached, an aspect in which the filter is laminated inside the optical filter may be used.

  FIG. 4 is a view showing an example of a laminated structure when the optical filter 17 according to Embodiment 7 of the present invention is attached to the front glass 19 of the plasma display panel 10. The optical filter 17 of Embodiment 7 in FIG. 4 includes a dye-containing pressure-sensitive adhesive layer 14 / electromagnetic wave shielding layer 12 / flattened layer 16 ′ / impact resistant layer 11 / near-infrared absorbing layer 13 / pressure-sensitive adhesive layer 16 / antireflection layer 15. Are sequentially stacked. Here, the planarization layer 16 ′ interposed between the electromagnetic wave shielding layer 12 and the impact resistant layer 11 is filled in the irregularities of the mesh structure of the electromagnetic wave shielding layer 12 and contributes to planarization on the electromagnetic wave shielding layer 12. As described above, the pressure-sensitive adhesive layer 16 may be used, and a non-adhesive thermoplastic resin or radiation (including ultraviolet rays) curable resin is filled in the irregularities of the mesh structure to have no adhesiveness. It may be a layer. Since the impact-resistant layer 11 made of the impact-resistant absorbent according to the present invention has adhesiveness as described above, an adhesive layer is not necessarily provided between the planarizing layer 16 ′ and the impact-resistant layer 11 that do not have adhesiveness. 16 may be omitted. If necessary, the embodiment 7 may be an embodiment in which the pressure-sensitive adhesive layer 16 is interposed between the planarizing layer 16 ′ and the impact resistant layer 11.

The dye-containing pressure-sensitive adhesive layer 14 in FIG. 4 may be replaced with the position of the pressure-sensitive adhesive layer 16 in FIG. 4 and may be in the following mode.
Embodiment 8: Adhesive layer 16 / electromagnetic wave shielding layer 12 / flattening layer 16 ′ / impact resistant layer 11 / near infrared absorbing layer 13 / dye-containing adhesive layer 14 / antireflection layer 15

In each of the above embodiments, a color tone adjusting dye and / or a dye such as a neon light absorbing dye is contained in the dye-containing pressure-sensitive adhesive layer 14, but may be contained in any layer constituting the optical filter. Is possible. For example, the near-infrared absorbing layer 13 may contain a color tone-adjusting dye and a neon light-absorbing dye, and the dye-containing near-infrared absorbing layer 13 having both a neon absorbing function and a color tone correcting function may be used. For example, the following embodiments are mentioned.
Embodiment 9: Impact resistant layer 11 / adhesive layer 16 / electromagnetic wave shielding layer 12 / adhesive layer 16 / dye-containing near-infrared absorbing layer 13 / adhesive layer 16 / antireflection layer 15
Embodiment 10: Adhesive layer 16 / electromagnetic wave shielding layer 12 / flattening layer 16 ′ / impact resistant layer 11 / dye-containing near-infrared absorbing layer 13 / adhesive layer 16 / antireflection layer 15

  In Embodiments 7 to 10 described above, the blackening treatment layer in the electromagnetic wave shielding layer 12 may be the pigment-containing pressure-sensitive adhesive layer 14 or the pressure-sensitive adhesive layer 16 side (the front side of the plasma display panel), even on the antireflection layer 15 side. )

Hereinafter, each layer used for the layer structure of the optical filter when the optical filter of the present invention is applied to a plasma display panel will be described as an example.
1. Impact-resistant layer Since the impact-resistant layer in the optical filter of the present invention is a layer made of the impact-resistant absorbent according to the present invention, the description thereof is omitted here. As described above, the impact-resistant layer made of the impact-resistant absorber according to the present invention contains a near-infrared absorbing dye, a color tone adjusting dye, and / or a dye such as a neon light absorbing dye, an ultraviolet absorber, and the like. You may do it.

2. Electromagnetic wave shielding layer The electromagnetic wave shielding layer has a function of shielding electromagnetic waves generated from a plasma display or the like, and a transparent base material, an adhesive layer or an adhesive layer (not shown), and a metal mesh layer are laminated in this order. It has a laminated structure.

(Metal mesh layer)
The metal mesh layer is a part of a layer constituting the electromagnetic wave shielding layer having a laminated structure. Among the layers constituting the electromagnetic wave shielding layer, the metal mesh layer particularly has a function of shielding electromagnetic waves generated from a plasma display or the like. Such a metal mesh layer is formed by laminating a metal foil on a transparent base material, which will be described later, with an adhesive layer (or an adhesive layer) and etching the metal foil into a mesh shape. In the present invention, the metal mesh layer is not particularly limited as long as it has electromagnetic wave shielding properties. For example, copper, iron, nickel, chromium, aluminum, gold, silver, Stainless steel, tungsten, titanium, or the like can be used. In the present invention, among the above, copper is preferable from the viewpoints of electromagnetic shielding properties, etching processing suitability, and handling properties. Moreover, as a kind of copper foil used, although rolled copper foil, electrolytic copper foil, etc. are mentioned, it is especially preferable that it is electrolytic copper foil. As a result, a uniform metal mesh layer having a thickness of 10 μm or less can be obtained, and when the surface of the metal mesh layer is blackened, the adhesion with chromium oxide and the like is good. Because it can be.

  Here, in this invention, it is preferable that the one surface or both surfaces of the said metal foil are blackened. The blackening process is a process of blackening the surface of the metal mesh layer with chromium oxide or the like. In the optical filter, this oxidation-treated surface is the surface on the viewer side or the surface opposite to the viewer side. Are arranged as follows. In the electromagnetic wave shielding layer 12 of FIGS. 2 to 4, the portions that are solidly filled with black indicate the film formed by the blackening process. The external light on the surface of the optical filter is absorbed by chromium oxide or the like formed on the surface of the metal mesh layer by this blackening treatment, so that it is possible to prevent light from being scattered on the surface of the optical filter and to achieve good transmission. Therefore, the optical filter can be obtained. From the viewpoint of preventing light scattering, the oxidized surface is preferably on the surface on the viewer side. Such a blackening treatment can be performed by applying a blackening treatment liquid to the metal foil.

As a blackening treatment method, different oxycarboxylic acid compounds such as tartaric acid, malonic acid, citric acid, and lactic acid are added to a CrO ₂ aqueous solution or a chromic anhydride aqueous solution to convert a part of hexavalent chromium into trivalent chromium. The reduced solution or the like can be applied by a roll coating method, an air curtain method, an electrostatic atomization method, a squeeze roll coating method, a dipping method or the like and dried. In addition, this blackening process may be performed after a metal foil is bonded to a transparent substrate with an adhesive layer (or an adhesive layer) and etched into a mesh shape.

  The black density on the surface of the blackened metal foil is preferably 0.6 or more. This is because the non-visibility can be further improved. Here, the black density is set to an observation viewing angle of 10 °, an observation light source D50, and a density standard ANSI T as an illumination type using GRETAG SPM100-11 (manufactured by KIMOTO) of COLOR CONTROL SYSTEM. It is a value measured later.

  The film thickness of the metal foil is preferably in the range of 1 μm to 100 μm, more preferably in the range of 5 μm to 20 μm. If the film thickness is thicker than the above range, it is difficult to make the pattern line width fine and fine by etching, and if the film thickness is thinner than the above range, sufficient electromagnetic shielding properties cannot be obtained.

Furthermore, it is preferable that the said metal foil has the 10-point average roughness based on JISB0601 in the range of 0.5 micrometer-10 micrometers. When it is smaller than the above range, even when the blackening treatment is performed, the external light on the surface of the optical filter is specularly reflected, so that the visibility is deteriorated. This is because it becomes difficult to apply the resist or the resist.
Here, the etching of the metal foil is performed after the metal foil is bonded to the transparent base material to be described later via the adhesive layer (or the pressure-sensitive adhesive layer). This etching can be performed by an ordinary photolithography method. For example, the resist can be applied to the surface of the metal foil, dried, and then exposed to light with a pattern plate and developed.

The above-described metal mesh layer used in the present invention preferably has a surface resistance in the range of 10 ⁻⁶ Ω / □ to 5 Ω / □, and more preferably in the range of 10 ⁻⁴ Ω / □ to 3Ω / □. . In general, the electromagnetic wave shielding property can be measured by surface resistance. It can be said that the lower the surface resistance, the better the electromagnetic wave shielding property. Here, the value of the surface resistance is measured by the method described in JIS K7194 “Resistivity test method using 4-probe method of conductive plastics” by the surface resistance measuring device Lorester GP, manufactured by Dia Instruments Co., Ltd. Value.

  The metal mesh layer after the etching treatment is preferably in the range of 50 μm to 500 μm, more preferably in the range of 100 μm to 400 μm, particularly in the range of 200 μm to 300 μm, and the mesh line width is in the range of 5 μm to 20 μm. It is preferable to be within. When the mesh line width is finer than the above range, disconnection may occur, which is not preferable from the aspect of electromagnetic shielding properties, and when the mesh line width is thicker than the above range, the visible light transmittance is low, for example, This is because the brightness of the plasma display is not preferable.

(Transparent substrate)
The transparent substrate is a part of the layer that constitutes the electromagnetic wave shielding layer, and is a layer that serves as a substrate for laminating the metal mesh layer via the adhesive layer (or pressure-sensitive adhesive layer). If the transparent base material used for this invention has transparency and an adhesive bond layer (or adhesive layer) can be formed, the kind etc. will not be specifically limited, For example, a polyethylene terephthalate (PET) , Polyesters such as polyethylene naphthalate (PEN), polyolefins such as cyclic polyolefin, polyethylene, polypropylene and polystyrene, vinyl resins such as polyvinyl chloride and polyvinylidene chloride, polycarbonate, acrylic resin, triacetyl cellulose (TAC), A film made of polyethersulfone or polyetherketone, which has a light transmittance in the visible region of 80% or more.

  These films may be colored as long as they do not interfere with the object of the present invention, and can be used as a single layer, but may be used as a multilayer film in which two or more layers are combined. Among these, PET is most preferable from the viewpoints of transparency, heat resistance, cost, and handleability. It is desirable that the light transmittance in the visible region is as high as possible. However, since the light transmittance of 50% or more is required for the final product, even when at least two sheets are laminated, the transparent substrate has 80%. This is because it suits the purpose. Since the higher the transmittance, the more transparent substrates can be laminated, the light transmittance is preferably 85% or more, and most preferably 90% or more. Therefore, it is also an effective means to reduce the thickness. It is. The thickness of the transparent substrate is not particularly limited as long as the transparency is satisfied, but is preferably in the range of 12 μm to 300 μm from the viewpoint of workability. If the thickness is less than 12 μm, the film is too flexible, and the metal mesh layer, which is a conductive layer, is easily stretched and wrinkled due to the tension during film formation and processing. . If it exceeds 300 μm, the flexibility of the film decreases, and continuous winding in each step is difficult and unsuitable. Furthermore, when laminating a plurality of sheets, there is a problem that workability is greatly deteriorated.

(Adhesive layer or adhesive layer)
Although the adhesive layer (or pressure-sensitive adhesive layer) is not shown in the electromagnetic wave shielding layer of FIGS. 2 to 4, it is a layer used to bond the transparent substrate and the metal mesh layer. The type of adhesive layer (or pressure-sensitive adhesive layer) is not particularly limited as long as it is a layer capable of adhering the metal mesh layer and the transparent substrate. The metal foil and transparent substrate constituting the metal mesh layer are bonded together via an adhesive layer (or pressure-sensitive adhesive layer), and then the metal foil is meshed by etching, so that the adhesive layer (or pressure-sensitive adhesive layer) ) Also preferably has etching resistance. Specifically, acrylic resin, polyester resin, polyurethane resin, polyvinyl alcohol alone or partially saponified product thereof, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer, polyimide resin, epoxy resin, polyurethane ester resin Etc. The adhesive layer (or pressure-sensitive adhesive layer) used in the present invention may be an ultraviolet curable type or a thermosetting type. In particular, an acrylic resin or a polyester resin is preferable from the viewpoints of adhesion to a transparent substrate, compatibility with a near infrared absorbing dye and / or neon light absorbing dye, dispersibility, and the like.

  Further, the adhesive layer (or pressure-sensitive adhesive layer) may contain one or more near infrared absorbing dyes and / or neon light absorbing dyes. In that case, it is preferable that the light transmittance in the wavelength region of 800 nm to 1100 nm is 20% or less, especially 15% or less, and the light transmittance in the wavelength region of 560 to 630 nm is 30% or less, especially 25% or less. Furthermore, the hydroxyl value and acid value of the resin must each be 10 or less. Thereby, it is possible to prevent the near-infrared absorbing dye and / or the neon light-absorbing dye from reacting with the reactive group in the resin due to the hydroxyl group and acid contained in the resin, stably absorbing near-infrared light, and / or Or it can be a thing which can exhibit a neon light absorption function.

  The transparent substrate and the metal foil for forming the metal mesh layer can be bonded via the adhesive layer (or pressure-sensitive adhesive layer) by a dry lamination method or the like. Moreover, it is preferable that the film thickness of this adhesive bond layer (or adhesive layer) is in the range of 0.5 μm to 50 μm, especially 1 μm to 20 μm. As a result, the transparent base material and the metal mesh layer can be firmly bonded, and the transparent base material is prevented from being affected by an etching solution such as iron oxide during the etching to form the metal mesh layer. Because it can.

3. Near-infrared absorbing layer The near-infrared absorbing layer basically has a near-infrared absorbing dye that absorbs near-infrared rays in a transparent binder resin.
As the near-infrared absorbing dye, when an optical filter is applied to the front surface of a plasma display panel, which is a typical application, the plasma display panel 7 generates a near-infrared region generated when light is emitted using xenon gas discharge, that is, What absorbs a wavelength range of 800 nm to 1100 nm, and the near infrared transmittance of the band is preferably 20% or less, more preferably 15% or less. At the same time, the near-infrared absorbing layer desirably 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, dithiol compounds, imonium compounds, diimonium compounds, and aminium. Compounds, pyrylium compounds, cerium compounds, squarylium compounds, copper complexes, nickel complexes, dithiol metal complexes organic near infrared absorbing dyes, tin oxide, indium oxide, magnesium oxide, titanium oxide, chromium oxide Zirconium oxide, nickel oxide, aluminum oxide, zinc oxide, iron oxide, ammonium oxide, lead oxide, bismuth oxide, inorganic near-infrared absorbing dyes such as lanthanum oxide, etc. can be used alone or in combination of two or more. .

  The type and amount of addition may be appropriately selected according to the absorption wavelength and absorption coefficient of the near-infrared absorbing dye, the color tone, the transmittance required for the display front plate, and the like. For example, the addition amount of the near-infrared absorber is about 0.1 to 15% by weight in the layer, and in order to protect these near-infrared absorbers from ultraviolet rays, benzophenone type, benzotriazole type, etc. in the layer An ultraviolet absorber may be included, and the addition amount of the ultraviolet absorber is about 0.1 to 10% by weight in the layer.

  The transparent binder resin is preferably a thermoplastic resin, and more preferably a synthetic resin not having a highly polar functional group or a synthetic resin having a highly polar functional group and a small number of functional groups. Preferred thermoplastic resins are acrylic resins, acrylonitrile resins, urethane resins, or polyester resins. The thermoplastic resin is good in terms of the solubility and stability maintenance of the dye and the functional durability of the colorant. Furthermore, the hydroxyl value and / or acid value of the resin must be 10 or less, respectively. Thereby, it can prevent that a near-infrared absorption pigment | dye etc. react with the hydroxyl group and acid group which are contained in the said resin, and can make a near-infrared absorption function etc. stable.

The production method of the near infrared ray absorbing layer is such that a release film / near infrared ray absorption is achieved by applying a near infrared absorbing dye-containing ink on a release film such as a PET film by a gravure reverse method or the like (for example, 10 g / m ² ). A laminated sheet composed of a dye / release film is obtained.

4). Dye-containing adhesive layer:
As the dye-containing pressure-sensitive adhesive layer used in the optical filter of the present invention, a dye-containing pressure-sensitive adhesive layer containing one or more neon light absorbing dyes and / or color tone adjusting dyes is used. The near infrared ray absorbing dye as described above may be contained. Here, the color tone adjusting dye is contained to adjust the color of the display filter for the purpose of improving the color purity of the light emitted from the panel, the color reproduction range, the display color when the power is turned off, and the like.

When the neon light absorbing dye is contained, the light transmittance in the wavelength region of 560 to 630 nm is preferably 30% or less, particularly preferably 25% or less.
Neon light absorbing dyes include dyes conventionally used as dyes having an absorption maximum of light transmittance in a wavelength region of at least 570 to 610 nm, for example, cyanine-based, oxonol-based, methine-based, subphthalocyanine-based or porphyrin And the like.

  Examples of known dyes that can be used as color tone adjusting dyes are described in JP-A Nos. 2000-275432, 2001-188121, 2001-350013, and 2002-131530. These dyes can be preferably used. In addition, other dyes such as anthraquinone, naphthalene, azo, phthalocyanine, pyromethene, tetraazaporphyrin, squarylium, and cyanine that absorb visible light such as yellow light, red light, and blue light. Can be used.

In this invention, it is preferable that the glass transition point temperature (Tg) of resin used for a pigment | dye containing adhesive layer exists in the range of 30 degreeC-150 degreeC, especially in the range of 40 degreeC-120 degreeC. As a result, when the resin is dissolved in a solvent and the like, and the solvent is volatilized and dried after application, the surface irregularities are raised at a temperature equal to or higher than the Tg of the transparent substrate, for example, using a mirror roll or the like. It is because it can be set as a flat and high quality optical filter with high transparency by applying. The temperature and pressure in the step of flattening the dye-containing pressure-sensitive adhesive layer are appropriately selected depending on the type of the transparent resin, but are usually in the range of 50 ° C. to 170 ° C., and the pressure is 0 in linear pressure. It is preferably within the range of 1 kg / cm ^{2 to} 10 kg / cm ² .

  Specific examples of the resin having the above-described properties include acrylic resins, ester resins, polycarbonate resins, urethane resins, cyclic polyolefin resins, polystyrene resins, polyimide resins, or polytetrafluoroethylene. (PTFE), perfluoroalkoxy resin (PFA) made of a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether, tetrafluoroethylene and hexafluoropropylene copolymer (FEP), tetrafluoroethylene and perfluoroalkyl vinyl ether and hexafluoropropylene copolymer ( EPE), copolymer of tetrafluoroethylene and ethylene or propylene (ETFE), polychlorotrifluoroethylene resin (PCTFE), ethylene and chloroto Examples include fluororesins such as copolymers with fluorethylene (ECTFE), vinylidene fluoride resins (PVDF), and vinyl fluoride resins (PVF). Among them, acrylic resins and ester resins are preferred from the viewpoint of transparency. A polycarbonate resin is preferable. The average molecular weight of the resin is preferably in the range of 500 to 600,000, particularly 10,000 to 400,000. This is because a transparent resin having the above properties can be obtained. Further, the hydroxyl value and / or the acid value of the resin is preferably 10 or less. Thereby, it can prevent that a neon light absorption pigment | dye etc. react with the hydroxyl group and acid group which are contained in the said resin, and can exhibit a neon light absorption function etc. stably.

  In this invention, it is preferable that the film thickness of such a pigment | dye containing adhesive layer exists in the range of 10 micrometers-50 micrometers. This is because by setting the amount within this range, the metal mesh layer can be flattened particularly when the dye-containing pressure-sensitive adhesive layer is formed on the unevenness of the metal mesh layer.

5. Anti-reflective layer The anti-reflective layer is disposed on the uppermost layer of the optical filter of the present invention and, like frosted glass, diffuses or diffuses light to produce a bocus method and / or a layer with a high refractive index and a layer with a low refractive index. Are layers formed by a technique for preventing reflection of light on the surface.

  That is, in order to scatter or diffuse light in the former method, it is fundamental to roughen the light incident surface. In this roughening treatment, the surface of the substrate is directly applied by sandblasting or embossing. A method for roughening, a method for providing a roughening layer containing an inorganic filler such as silica or an organic filler such as resin particles in a resin that is cured by radiation or heat or a combination on the surface of the substrate, and a substrate A method of forming a porous film with a sea-island structure on the surface can be mentioned.

In addition, as a method of preventing the reflection of light on the latter surface, the reflection of the surface can be suppressed and the reflection can be improved by laminating a material having a high refractive index and a material having a low refractive index alternately and forming a multilayer (multi-coating). The prevention effect can be obtained. Usually, the antireflection layer is formed by a vapor phase method or the like in which a low refractive index material typified by SiO ₂ and a high refractive index material such as TiO ₂ or ZrO ₂ are alternately formed by vapor deposition.

In order to improve the antireflection effect, the refractive index of the low refractive index layer is preferably 1.45 or less. Examples of the material having these characteristics include LiF (refractive index n = 1.4), MgF ₂ (refractive index n = 1.4), 3NaF · AlF ₃ (refractive index n = 1.4), AlF ₃ ( Inorganic materials such as refractive index n = 1.4), Na ₃ AlF ₆ (refractive index n = 1.33), SiO ₂ (refractive index n = 1.45) are made into fine particles, and acrylic resin, epoxy resin, etc. Inorganic low-reflective materials, fluorine-based / silicone-based organic compounds, thermoplastic resins, thermosetting resins, radiation-curable resins, and the like can be used.

Furthermore, a material in which a sol obtained by dispersing ultrafine silica particles of 5 to 30 nm in water or an organic solvent and a fluorine-based film forming agent can be used. The sol in which the ultrafine silica particles of 5 to 30 nm are dispersed in water or an organic solvent can be obtained by a method of dealkalizing alkali metal ions in the alkali silicate salt by ion exchange or the like, or neutralizing the alkali silicate salt with a mineral acid. A known silica sol obtained by condensing active silicic acid known by the method, etc., a known silica sol obtained by condensing alkoxysilane with hydrolysis in the presence of a basic catalyst in an organic solvent, and the above-mentioned An organic solvent-based silica sol (organosilica sol) obtained by substituting water in the aqueous silica sol with an organic solvent by a distillation method or the like is used. These silica sols can be used in both aqueous and organic solvent systems. In producing the organic solvent-based silica sol, it is not necessary to completely replace water with an organic solvent. The silica sol contains solids 0.5 to 50% strength by weight as SiO _2. Various structures such as a spherical shape, a needle shape, and a plate shape can be used for the structure of the ultrafine silica particles in the silica sol. As the film forming agent, alkoxysilane, metal alkoxide, hydrolyzate of metal salt, or fluorine-modified polysiloxane can be used.

  The low refractive index layer is obtained by diluting the above-described material into a solvent, for example, a wet coating method such as spin coating, roll coating or printing, or a vapor phase method such as vacuum deposition, sputtering, plasma CVD, or ion plating. After being provided on the high refractive index layer and dried, it can be obtained by curing with heat or radiation (in the case of ultraviolet rays, the above-mentioned photopolymerization initiator is used).

  The high refractive index layer is formed by using a binder resin having a high refractive index in order to increase the refractive index, adding ultrafine particles having a high refractive index to the binder resin, or using these in combination. To do. The refractive index of the high refractive index layer is preferably in the range of 1.55 to 2.70.

  As the resin used for the high refractive index layer, any resin can be used as long as it is transparent, and a thermosetting resin, a thermoplastic resin, a radiation (including ultraviolet) curable resin, or the like can be used. Thermosetting resins include phenolic resin, melamine resin, polyurethane resin, urea resin, diallyl phthalate resin, guanamine resin, unsaturated polyester resin, aminoalkyd resin, melamine-urea cocondensation resin, silicon resin, polysiloxane resin, etc. A curing agent such as a crosslinking agent and a polymerization initiator, a polymerization accelerator, a solvent, a viscosity modifier and the like can be added to these resins as necessary.

As ultrafine particles having a high refractive index, for example, ZnO (refractive index n = 1.9), TiO ₂ (refractive index n = 2.3 to 2.7), which can also have an ultraviolet shielding effect, Fine particles of CeO ₂ (refractive index n = 1.95), antimony-doped SnO ₂ (refractive index n = 1.95) or antistatic effect, which can prevent dust adhesion Examples thereof include fine particles of ITO (refractive index n = 1.95). Other fine particles include Al ₂ O ₃ (refractive index n = 1.63), La ₂ O ₃ (refractive index n = 1.95), ZrO ₂ (refractive index n = 2.05), Y ₂ O _3. (Refractive index n = 1.87). These fine particles are used singly or in combination, and those in the form of a colloid dispersed in an organic solvent or water are good in terms of dispersibility, and the particle size is 1 to 100 nm, the transparency of the coating film To preferably 5 to 20 nm.

In order to provide the high refractive index layer, the material described above is diluted with a solvent, for example, provided on a substrate by a method such as spin coating, roll coating, or printing, dried, and then subjected to heat or radiation (in the case of ultraviolet rays, the above-mentioned). The photopolymerization initiator may be used for curing.
Further, the antireflection layer may contain one or more near infrared absorbing dyes and / or neon light absorbing dyes. In that case, the light transmittance in a wavelength region of 800 nm to 1100 nm is 20% or less, particularly 15% or less, and the light transmittance in a wavelength region of 560 to 630 nm is preferably 30% or less, particularly preferably 25% or less. Furthermore, the resin must have a hydroxyl value and an acid value not more than predetermined values. Thereby, it is possible to prevent the near-infrared absorbing dye and / or neon light absorbing dye from reacting due to the hydroxyl group and acid value contained in the resin, and the near-infrared absorbing ability and / or neon light can be stably stabilized. An absorption function can be exhibited. Moreover, it is preferable to contain an ultraviolet absorber in the antireflection layer from the viewpoint of providing the antireflection layer with an ultraviolet shielding function.

6). Adhesive layer The adhesive layer of the optical filter is a layer for adhering each layer in the optical filter. For example, a commercially available double-sided adhesive tape (eg, CS-9611: trade name, manufactured by Nitto Denko Corporation) is used. it can.

  As described above, each layer has been exemplified, but the optical filter for plasma display according to the present invention has a resin layer containing a near-infrared absorbing compound, and has a transmittance of 20% or less in a wavelength range of 800 to 1100 nm. It is preferable that it is 15% or less from the viewpoint of blocking near-infrared rays that are emitted from the inside of the display and may cause other devices to malfunction.

  Further, the optical filter for plasma display according to the present invention has a resin layer containing a neon light absorbing compound having a maximum absorption wavelength in the wavelength range of neon light 560 to 630 nm, and the transmittance of the maximum absorption wavelength in the wavelength range. Is preferably 30% or less, more preferably 25% or less, from the viewpoint of blocking neon light emitted from the inside of the display and affecting the color tone.

In the optical filter for plasma display according to the present invention, having an electromagnetic wave shielding layer that shields static electricity and / or electromagnetic noise generated from the plasma display device reduces the intensity of electromagnetic wave emission within the standard. preferable.
In the optical filter for plasma display according to the present invention, the transmittance in the wavelength range of 380 to 780 nm of visible light is preferably 30% or more, and more preferably 35% or more from the viewpoint of obtaining a highly transparent optical filter. .

  In addition, the optical filter for plasma display according to the present invention preferably has an impact resistance such that the breaking energy of the plasma display panel by an impact test is 0.5 J or more, preferably 0.6 J or more.

<Method for manufacturing optical filter>
The optical filter according to the present invention can be manufactured, for example, by bonding sheets constituting each layer. The bonding can be performed using, for example, a laminating machine as shown in FIG. A manufacturing example of the optical filter having the layer structure shown in FIG. 2 will be described below.

i) Production of Laminated Sheet Consisting of Antireflection Layer 15 / Dye-Containing Adhesive Layer 14 / Releasing Film The antireflection layer 15 is wound around the first paper feeding section 21 of the laminating machine in FIG. 2 A sheet obtained by winding up a laminated sheet composed of a release film / dye-containing pressure-sensitive adhesive layer 14 / release film is disposed in the paper feeding unit 22. Next, while feeding out the antireflection layer 15 from the first paper feed unit 21, on the other hand, a laminated sheet composed of the release film / dye-containing pressure-sensitive adhesive layer 14 / release film is fed out from the second paper feed unit 22 at the same time. The sheet is wound on the second release film winding roll 24 on the side, and the sheet made of the antireflection layer 15 and the dye-containing pressure-sensitive adhesive layer 14 / release film is laminated by the first laminating unit 25 at a laminating pressure of about 3 kgf / m. Then, the laminated sheet is laminated by the second laminating unit 26 at a laminating pressure of about 5 kgh / m, wound on a take-up roll 27, and made of an antireflection layer 1 / dye-containing pressure-sensitive adhesive layer 2 / release film. Get. At this time, the first release film winding roll 23 is not used because there is no release film to be wound.

ii) Production of laminated sheet consisting of antireflection layer 15 / dye-containing pressure-sensitive adhesive layer 14 / near-infrared absorbing layer 13 / release film Antireflection layer 15 / dye-containing pressure-sensitive adhesive layer 14 obtained in step i) A laminated sheet made of a mold film is arranged in the first paper feed unit 21. On the other hand, what wound up the lamination sheet which consists of a release film / near-infrared absorption layer 13 / release film in the 2nd paper supply part 22 is arrange | positioned. Lamination is performed in the same manner as in step i), and the film is wound on a take-up roll 27 to obtain a laminated sheet composed of the antireflection layer 15 / dye-containing pressure-sensitive adhesive layer 14 / near infrared absorption layer 13 / release film.

Thereafter, in the same manner, the laminated sheet obtained in the previous process is arranged in the first paper feeding unit 21, while the sheet to be newly laminated is arranged in the second paper feeding unit 22,
iii) Laminated sheet comprising antireflection layer 15 / dye-containing pressure-sensitive adhesive layer 14 / near infrared absorption layer 13 / pressure-sensitive adhesive layer 16 / release film,
iv) laminated sheet comprising antireflection layer 15 / dye-containing pressure-sensitive adhesive layer 14 / near-infrared absorbing layer 13 / pressure-sensitive adhesive layer 16 / electromagnetic wave shielding layer 12 / release film,
v) Laminated sheet comprising antireflection layer 15 / dye-containing pressure-sensitive adhesive layer 14 / near infrared absorption layer 13 / pressure-sensitive adhesive layer 16 / electromagnetic wave shielding layer 12 / pressure-sensitive adhesive layer 16 / release film,
vi) Obtaining a laminated sheet comprising the antireflection layer 15 / the dye-containing pressure-sensitive adhesive layer 14 / the near-infrared absorbing layer 13 / the pressure-sensitive adhesive layer 16 / the electromagnetic wave shielding layer 12 / the pressure-sensitive adhesive layer 16 / the impact resistant layer 11 / the release film. Thus, the optical filter according to the present invention can be obtained.

D. Plasma display panel The plasma display panel according to the present invention is a plasma display panel in which the optical filter according to the present invention is directly attached to a display surface.
In the plasma display panel according to the present invention, since the optical filter according to the present invention is directly attached to the display surface, there is no space between the front glass of the panel and the protective plate, thereby degrading the image quality and distorting the image. In addition, there is no problem of causing a reduction in weight, and a reduction in weight and thickness can be realized. Further, the manufacturing process can be simplified and the cost can be reduced.

  The plasma display panel of the present invention includes an optical filter according to the present invention as a constituent element of a general plasma display panel such as a glass substrate, gas, electrode, electrode lead material, thick film printing material, and phosphor. is there. Furthermore, a plasma display device is obtained by combining the housings. Two glass substrates, a front glass substrate and a back glass substrate, are used, electrodes and a dielectric layer are formed on the two glass substrates, and a phosphor layer is formed on the back glass substrate. A gas made of helium, neon, xenon, or the like is sealed between the two glass substrates. For example, as shown in FIG. 2, the plasma display panel 18 according to the present invention is optically disposed on the front glass 19 of the plasma display panel main body 10 via the impact resistant layer 11 made of the above-described impact resistant absorbent material according to the present invention. The filter 17 is joined.

The plasma display panel according to the present invention includes, for example, the antireflection layer 15 / dye-containing pressure-sensitive adhesive layer 14 / near infrared absorption layer 13 / pressure-sensitive adhesive layer 16 / electromagnetic wave shielding layer 12 / pressure-sensitive adhesive layer obtained in the step vi). 16 / Impact resistant layer 11 / Release film of a laminated sheet composed of a release film is peeled off, and the exposed impact resistant layer 11 can be bonded to the front glass 19 of the plasma display panel body 10 to be manufactured.
In addition, this invention is not limited to the said embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.

Hereinafter, the present invention will be specifically described with reference to examples.
Example 1
1. Preparation of coating solution for forming impact-resistant absorbent material In a 2-liter four-necked flask equipped with a stirrer, thermometer, nitrogen gas inlet tube, and cooling tube, 919 parts by weight of 2-ethylhexyl acrylate, acrylic 80 parts by weight of acid, 1 part by weight of 2-hydroxyethyl acrylate, and 0.6 g of n-dodecyl mercaptan were added and heated to 50 ° C. while the air in the flask was replaced with nitrogen. Next, 0.025 g of 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile as a polymerization initiator was added under stirring and mixed uniformly. After the polymerization initiator was added, the temperature of the reaction system rose, but when the polymerization reaction was continued without cooling, the temperature of the reaction system reached 119 ° C. and then gradually began to decrease. When the temperature of the reaction system dropped to 115 ° C., forced cooling was performed to obtain a syrup-type acrylic pressure-sensitive adhesive. This syrup-type acrylic pressure-sensitive adhesive contained 67% by weight of monomer and 33% by weight of polymer. The weight average molecular weight (Mw) of the polymer content measured by GPC was 210,000.
A photopolymerization initiator (Irgacure 184) was added to the obtained syrup-type acrylic pressure-sensitive adhesive so as to be 0.3 parts by weight with respect to 100 parts by weight of the syrup-type acrylic pressure-sensitive adhesive, and a crosslinking agent (tolylene diisocyanate). ) Was added so as to be 0.5 parts by weight with respect to 100 parts by weight of the syrup-type acrylic pressure-sensitive adhesive, to obtain a coating solution for forming an impact-resistant absorbent.

2. Coating process Apply the above-obtained coating solution for forming an impact-absorbing material on a release film (silicone-coated PET) at a thickness of 1000 μm so that no bubbles enter from the top 5 seconds after coating. A release film (PET coated with silicone) was bonded.

3. Weak irradiation and strong irradiation process About the coating film sandwiched on both sides by the release film obtained in 2. above, UV light is used for 120 seconds each on both sides with weak illuminance (5 mW / cm ² ). Irradiated. Thereafter, the coating film was irradiated with ultraviolet rays for 10 seconds each with a high intensity mercury lamp (500 mW / cm ² ) at a high illuminance (500 mW / cm ² ).

4). Heating Step The coating film sandwiched on both sides by the release film obtained in 3. above was heated in an oven at 60 ° C. for 1 week to obtain an impact resistant absorbent material according to the present invention.

[Evaluation]
(1) Glass adhesion One side of the release film of the shock-absorbing material obtained in Example 1 was peeled off, and sodium soda glass was attached. This was cut into a width of 25 mm, bonded based on the test of JIS Z0237-2000, and peeled at 90 degrees at a speed of 200 mm / min, and measured. As a result, the glass adhesion of the impact-resistant absorbent material obtained in Example 1 was 14 N / 25 mm.

(2) Adhesive residue test In the above evaluation of glass adhesion, there was no adhesive remaining on the glass when it was peeled off, and it was judged visually that there was no adhesive residue. Note that the edge of the adhesive may remain about 0.1 to 0.5 mm, but this was cut off because the shape of the adhesive on the cut surface and the internal stress were discontinuous. Since it does not affect the display when used in a panel, it is not regarded as glue residue.

(3) Tensile modulus 25 ° C., distance between chucks 20 mm, width 5 mm, strain 10 μm, temperature increase rate 2 ° C./min, frequency 10 Hz, dynamic viscoelasticity measuring instrument (Rheogel-, manufactured by UBM Co., Ltd.) E4000).

(4) Haze The haze was measured by a method based on JIS K7105-1981. The shock-absorbing material of Example 1 was bonded to a 1.2 mm thick glass plate, and the easy-adhesion surface of a PET film (Toyobo Cosmo Shine A-4100) was placed on the opposite side of the glass plate. A haze value was measured using a sample prepared by bonding so as to overlap the material. As a result, the haze value was 2.1%.

(5) Component amount having a molecular weight of 1000 or less The shock-absorbing material-forming coating solution obtained in Example 1 was dissolved in a solvent (tetrahydrofuran), and the obtained solution was subjected to liquid chromatography measurement. Tosoh Co., Ltd., HLC-8120 was used as the device, and G7000HXL (7.8 mmID × 30 cm), GMHXL (7.8 mmID × 30 cm), G2000HXL (7.8 mmID × 30 cm), 1 column. It measured using. As a result, the amount of components having a molecular weight of 1000 or less in the impact-resistant absorbent coating solution obtained in Example 1 was 2.1% by weight.

(6) Peeling after Display Bonding and Adhesive Residue After the impact-resistant absorbent material obtained in Example 1 was bonded to a 42-inch plasma display, peeling was attempted 30 minutes later. As a result, it was able to be peeled off without problems by human power. Further, there was no adhesive remaining on the front glass of the plasma display, and it was visually judged that “no adhesive residue”.

(7) Impact resistance A steel ball having a diameter of 50.8 mm was obtained by using the impact test apparatus shown in FIG. 6 and increasing the height so that the impact energy increased by 0.1 J in order from the height of 9.6 cm. 35 (weight 534 g) (specified in the steel ball for JIS B1501 ball bearing) was dropped. After this impact resistance test, it was visually confirmed whether or not the impact-absorbing material was broken (damaged or cracked), and the fracture energy was measured without any failure and no abnormality. As the test stand 31, a SUS base 32 and a glass plate 33 having a thickness of 10 mm bonded together were used. On the test bench 31, a high strain point glass plate (PD-200: trade name, thickness 2.8 mm) manufactured by Asahi Glass Co., Ltd. was placed as a front glass plate 34 for plasma display. The impact energy when the steel ball is dropped is, for example, when the height is 9.6 cm, the steel ball weight (Kg) × height (m) × 9.8 (m / s ² ) = 0.534. It is calculated | required as * 0.096 * 9.81 and is about 0.5J.
As a result, there was no failure up to 3.1 J and no abnormality was observed, and the shock-absorbing material of Example 1 had an impact resistance of 3.1 J as a breaking energy according to the impact test.

(Comparative Example 1)
Acetylacetone zinc salt as a metal compound with respect to 100 parts by weight of an acrylate copolymer obtained by copolymerizing 78.4% by weight of n-butyl acrylate, 19.6% by weight of 2-ethylhexyl acrylate and 2.0% by weight of acrylic acid : 0.5 parts by weight and acetylacetone aluminum salt: 0.7 parts by weight were melted and stirred, and then formed into a sheet with a predetermined thickness (0.5 mm) as the shock-resistant absorbent material of Comparative Example 1. This corresponds to the pressure-sensitive adhesive sheet of Example 1 in Patent Document 4 described above.

  It was 25 N / 25mm when the glass adhesiveness of the obtained impact-resistant absorber of the comparative example 1 was measured similarly to Example 1. FIG. Moreover, after pasting together on the 42-inch plasma display similarly to the impact-resistant absorber of Example 1, peeling was attempted after 30 minutes. As a result, it could not be peeled off by human power. Further, as a result of the same impact resistance test as that of the impact resistant absorbent material of Example 1, it had an impact resistance of 2.5 J.

It is process drawing which shows an example of the manufacturing method of the impact-resistant absorber of this invention. It is a figure which shows an example of the laminated structure at the time of sticking the optical filter of Embodiment 1 of this invention directly on the front surface of a plasma display panel. It is a figure which shows an example of the laminated structure at the time of sticking the optical filter of Embodiment 4 of this invention directly on the front surface of a plasma display panel. It is a figure which shows an example of the laminated structure at the time of sticking the optical filter of Embodiment 7 of this invention directly on the front surface of a plasma display panel. It is a figure which shows one example of the laminating machine for laminating each layer which comprises the optical filter of this invention. It is a figure which shows an impact test apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Release film 2 Coating liquid for impact-resistant absorber formation 3 Weak ultraviolet rays 4 Coating film for impact-resistant absorber formation 5 Strong ultraviolet rays 6 Impact-resistant absorber 10 Plasma display panel main body 11 Impact resistant layer 12 Electromagnetic wave shielding layer 13 Near infrared rays Absorbing layer 14 Dye-containing adhesive layer 15 Antireflection layer 16 Adhesive layer 17 Optical filter 18 Plasma display panel 19 Front glass 21 First paper supply unit 22 Second paper supply unit 23 First release film winding roll 24 Second Release film winding roll 25 First laminating unit 26 Second laminating unit 27 Winding roll 31 Test table 32 Base 33 Glass plate 34 Front glass plate 35 Steel ball

Claims (15)

  A shock-absorbing material for flat displays having a single layer thickness of 100 μm or more and a glass adhesion of 3 to 15 N / 25 mm. The shock-absorbing material for flat display according to claim 1, wherein the tensile elastic modulus is 1 x 10 ⁴ to 1 x 10 ⁶ Pa · s at 25 ° C.   The shock-absorbing material for flat display according to claim 1 or 2, wherein a component having a molecular weight of 1000 or less is 3% by weight or less.   The shock-absorbing material for flat display according to any one of claims 1 to 3, comprising an acrylic pressure-sensitive adhesive.   Polymer in which the acrylic pressure-sensitive adhesive is polymerized using at least one selected from the group consisting of 2-ethylhexyl (meth) acrylate, n-butyl (meth) acrylate, and lauryl (meth) acrylate. The shock-absorbing material for flat display according to claim 4, wherein   The shock-absorbing material for flat display according to any one of claims 1 to 5, wherein the tackifier is less than 3% by weight.   An optical filter for being directly attached to a display surface of a plasma display panel, comprising an impact resistant layer made of the impact resistant absorbent material according to any one of claims 1 to 6, wherein the plasma display is characterized in that Optical filter.   8. The plasma according to claim 7, wherein the layer constituting the surface directly attached to the optical filter is an impact resistant layer made of the impact resistant absorbent material according to any one of claims 1 to 6. Optical filter for display.   The optical filter for plasma display according to claim 7 or 8, wherein the optical filter for plasma display has a resin layer containing a near-infrared absorbing compound and has a transmittance in the wavelength range of 800 to 1100 nm of 40% or less.   It has a resin layer containing a neon light absorbing compound having a maximum absorption wavelength in a wavelength range of neon light 560 to 630 nm, and the transmittance of the maximum absorption wavelength in the wavelength range is 30% or less. The optical filter for plasma display according to any one of 7 to 9.   The optical filter for plasma display according to any one of claims 7 to 10, wherein transmittance in a wavelength range of visible light of 380 to 780 nm is 40% or more.   The optical filter for plasma display according to any one of claims 7 to 11, further comprising an electromagnetic wave shielding layer for shielding static electricity and / or electromagnetic wave noise generated from the plasma display device.   A plasma display panel, wherein the optical filter according to claim 7 is directly attached to a display surface. A coating step of applying a shock-absorbing material-forming coating solution that is solvent-free and contains at least one photopolymerizable monomer and a polymer of the photopolymerizable monomer, and 1 mW / cm ² or more and less than 40 mW / cm ² A method for producing a shock-absorbing material for flat displays, comprising a weak irradiation step of irradiating ultraviolet rays at an illuminance of 20 to 180 seconds and a strong irradiation step of irradiating ultraviolet rays at an illuminance of 40 mW / cm ² or more for 0.1 to 20 seconds. .   The manufacturing method of the impact-resistant absorber for flat displays of Claim 13 whose said coating liquid for impact-resistant absorber formation is an acrylic adhesive.

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