KR20040017552A - Glass crack-resistant structure and plasma display unit - Google Patents

Abstract

PURPOSE: A glass crack-resistant structure and a plasma display device are provided to reduce the weight and thickness of the plasma display device by directly bonding a glass crack-resistant member to a glass substrate and removing an air layer. CONSTITUTION: A glass crack-resistant structure comprises a surface glass crack-resistant member, a glass substrate, a metal plate, and an inner glass crack-resistant member interposed between the glass substrate and the metal plate. The inner glass crack-resistant member is made of an elastic or visco-elastic material having a dynamic shear elasticity of 1x10¬9Pa or lower. The breakdown impact energy generated when a steel member having a diameter of 50mm and a weight of 500g is dropped on the surface glass crack-resistant member, is 1.2 times or more higher than the breakdown impact energy for the glass crack-resistant structure which is not provided with the inner glass crack-resistant member.

Description

GLASS CRACK-RESISTANT STRUCTURE AND PLASMA DISPLAY UNIT}

The present invention relates to a glass crack preventing structure, and a plasma display panel (hereinafter referred to as PDP) apparatus employing the same.

Glass cathode ray tube (cathode ray tube) is a safety standard (UL standard, radio wave control method, etc.) for television and display device. It is not scattered or penetrated by impact test by dropping steel ball. It was necessary to design the panel glass thickly.

Japanese Patent Laid-Open Publication Nos. 94-333515, 94-333517, and the like regarding such CRT glass panels include a synthetic resin protective film (thermosetting urethane resin and polyester film) having self-resilience as a light weighting means without thickening the glass panel. Disclosed is a glass CRT made of a laminated glass tube. However, this is characterized by anti-scattering properties, there is no description of the crack prevention of the glass panel substrate, it does not combine with the crack prevention.

In addition, Japanese Patent Laid-Open Publication No. 99-174206 as a protective filter includes a front protective plate for installing a transparent resin sheet within 10 mm of the display device to protect the inner glass substrate of a flat panel display device (various LCDs, PDPs). It is described to protect its own glass. However, this configuration has many problems such as double glazing of external light, increase in reflectance, and deterioration of image quality due to parallax due to the presence of an air layer between the glass panel and the protective plate. There was a problem such that dust, cigarettes, etc. accumulated on the surface make cleaning difficult.

In addition, in PDPs where size and weight are important, there is a tendency to thin the panel thickness itself, so it is counterproductive to install a protective filter away from the panel. As a result, the known technology is not a protective filter for preventing the breakage of the panel while being thin and light in a large size display device such as a PDP.

In addition, the PDP generates a discharge in a rare gas enclosed inside the panel, particularly a neon-based gas, and emits R, G, and B phosphors installed in the cells inside the panel by the vacuum ultraviolet rays generated at that time. During the process, unnecessary electromagnetic waves and near-infrared rays are emitted simultaneously for PDP operation. In particular, since electromagnetic radiation is regulated by VCCI, FCC, etc., and the adverse effects on the human body are concerned recently, it is necessary to shield electromagnetic waves emitted from the PDP.

In addition, with respect to near infrared rays, the wavelength range of emitted near infrared rays is about 800-1,200 nm. On the other hand, the light receiving element of the infrared sensor used for remote control devices, such as a household telephone product, a karaoke base material, and an audio visual apparatus, has many peaks of a light reception sensitivity with about 700-1,300 nm. For this reason, there is a problem that the near infrared rays emitted from the PDP malfunction the remote controller, and it is necessary to block the near infrared rays generated from the PDP.

Against this background, filters for blocking electromagnetic waves and near infrared rays generated from PDPs are examined. For example, a metal mesh is provided in the filter which shields an electromagnetic wave; Glass plates or acrylic plates subjected to patterning mesh processing by etching; Attaching a metal mesh or a film subjected to patterning mesh processing by etching to a glass plate or an acrylic plate; BACKGROUND ART A transparent multilayer thin film laminate having a multilayer structure in which a metal thin film layer is sandwiched with a transparent thin film layer is known. Moreover, the filter etc. which combined the near-infrared absorbing material by the pigment | dye which absorbs near-infrared, Cu complex phosphate ester type polymer, etc. are already examined by the filter which shields near-infrared.

However, such a shielding filter is generally disposed as a front protection plate at a position within 10 mm from the PDP, and is not directly adhered to the PDP panel through a transparent adhesive. This is because the glass substrate of the PDP panel is very fragile, so that the glass substrate of the PDP panel is placed at a position of several mm to 10 mm away from the PDP panel to function as a front protective filter.

The present invention, in view of the above circumstances, unlike the conventional PDP front plate, a structure that directly adheres a transparent anti-breaking material to a glass substrate, such as a PDP panel, and eliminates the air layer, there is no double shine of external light, light weight and thinning It is an object of the present invention to provide a glass-breaking structure capable of adding a function of shielding electromagnetic waves and near-infrared rays as well as having a large glass-breaking effect, and a PDP device employing the same.

MEANS TO SOLVE THE PROBLEM As a result of examining the example in order to achieve the said objective, when designing the glass crack prevention structure which arrange | positioned the surface glass crack prevention material (1), a glass substrate, and a metal plate in this order, Due to the direct sticking structure, there is no air layer between the glass substrate and the glass cracking preventing material, and thus there is no problem such as double reflection of external light, thereby obtaining a glass cracking preventing structure that can be lightened and thinned. By interposing the inner glass crack prevention material 2 of a specific configuration between the glass substrate and the metal plate in addition, the glass break prevention effect is remarkably increased, and if necessary, shielding of electromagnetic waves or near infrared rays to the surface glass crack prevention material 1 itself. Function, anti-reflection function to reduce external light shining, function to adjust color of visible region, etc. A glass member having a surface adjacent to the installation when the crack preventing member (1) and completed the invention by finding that these functions are added to obtain the number of the glass breakage prevention structure.

That is, this invention is an elastic body to viscoelasticity whose dynamic shear modulus is 1 * 10 <^9> Pa or less between a glass substrate and a metal plate in the glass fracture prevention structure which arrange | positioned the surface glass antibreak material 1, a glass substrate, and a metal plate in this order. The glass break prevention structure characterized by interposing the inner glass break prevention material (2) which consists of a sieve, Especially when the steel ball of diameter 50mm and weight 500g falls on the surface glass break prevention material (1) The breakdown impact energy B at which the substrate breaks is 1.2 times or more of the above breakdown impact energy A with respect to the glass break prevention structure having the same structure except that the internal glass break prevention material 2 is not interposed. It relates to a glass crack prevention structure. Moreover, this invention relates to the PDP apparatus characterized by having the glass shatterproof structure of the said structure.

In addition, when said "breaking impact energy (A) and (B)" is h, when height of glass substrate is destroyed by falling of steel ball, "weight of steel ball (0.5 kg) x h (m) x 9.8 (m) / Second ² ) ". In addition, said "glass substrate is destroyed" means that a glass substrate is broken and a crack, gold, etc. generate | occur | produce, or these cause a malfunction on a device, such as a light emission defect.

The glass shatterproof structure of the present invention is essentially an inner glass further between the glass substrate and the metal plate, in addition to the basic configuration in which the surface glass shatterproof material 1, the glass substrate (corresponding to the PDP) and the metal plate are arranged in this order. It takes the structure which interposed the crack prevention material 2. Each of these components is explained in full detail below.

Since the surface glass crack preventing material 1 is provided on the viewer side of the glass substrate, that is, on the PDP surface side where the image of the display device is displayed when applied to the PDP device, the visible light transmittance is 30% or more, preferably 40%. The visible light reflectivity may be 5% or less. In addition, the thickness may range from 0.05 to 10 mm. If too thin, the glass panel substrate is not effective in preventing cracking and scattering, which causes safety problems. In addition, if the thickness is too thick, the quality of the PDP is deteriorated or the weight and thickness of the PDP panel are reduced.

The structure, composition, and thickness of the surface glass crack preventing material 1 are not limited, and in addition to having the visible light transmittance and the visible light reflectivity, the surface glass crack preventing material 1 may have a shock relieving property that mitigates adhesion to the glass substrate and external impact. It comprises a single layer or a multilayered structure made of a material that combines adhesion to a glass substrate and shock resistance; The multilayer structure of the layer which consists of a material which has adhesiveness with respect to a glass substrate, and the layer which consists of a material which has impact relieving property, etc. are mentioned.

As a material which has the adhesiveness with respect to a glass substrate, and shock relaxation property, adhesives, such as an acryl type, rubber type, and polyester type, especially the acrylic adhesive with high transparency are used preferably. This acrylic pressure sensitive adhesive contains an appropriate additive as necessary in the acrylic polymer, and may be a thermal crosslinking type or a light (ultraviolet or electron beam) crosslinking type in addition to the non-crosslinking type.

The acrylic polymer mainly contains one or two or more kinds of alkyl (meth) acrylic acid esters having a glass transition point (Tg) of 60 ° C. or lower to impart proper wettability or flexibility, and a functional group-containing monomer or the like, if necessary. One or two or more types of copolymerizable monomers are obtained by polymerizing by a polymerization method such as solution polymerization, emulsion polymerization, bulk polymerization (particularly by ultraviolet irradiation), suspension polymerization or the like using an appropriate polymerization catalyst. Will be.

In addition to the pressure-sensitive adhesive, natural polymer glue, starch, semi-synthetic polymer cellulose acetate, synthetic polymer polyvinyl acetate, polyvinyl chloride, epoxy resin, urethane resin, polychloroprene, acrylonitrile-butadiene copolymer, melamine resin, acrylic Adhesives based on resins, ethylene-vinyl acetate copolymers, polyester resins, polyamide resins, and the like can also be used. These can also be used as adhesives of various curing types such as room temperature curing, heat curing, ultraviolet ray, electron beam, laser irradiation curing type.

In addition, the material having a shock-absorbing property is a resin having good transparency, mechanical strength, heat resistance, and the like, and a polyester resin, (meth) acrylic resin, polycarbonate resin, polyethylene naphthalate resin, polyethylene terephthalate resin, triacetyl cellulose, aton resin , Epoxy resin, polyimide resin, polyetherimide resin, polyamide resin, polysulfone, polyphenylene sulfide, polyether sulfone and the like can be used.

As other materials, ionomer resins obtained by crosslinking molecules of an ethylene-methacrylic acid copolymer with metal ions (Na ⁺ , Zn ^2+, etc.); Thermoplastic resins such as ethylene-vinyl acetate copolymer, polyvinyl chloride resin, ethylene-acrylate copolymer, polyethylene, polypropylene, polybutyral resin and polystyrene resin; Or polystyrene-based, polyolefin-based, polydiene-based, polyvinyl chloride-based, polyurethane-based, polyester-based, polyamide-based, fluorine-based, chlorinated polyethylene-based, polynorbornene-based, polystyrene-polyolefin-based copolymer, (hydrogenated) polystyrene Thermoplastic elastomers, such as butadiene-based copolymers and polystyrene-vinyl polyisoprene-based copolymers, are used. In addition, the thing which mix | blended the said thermoplastic elastomer with polyolefin, such as polyethylene and a polypropylene, etc. can also be used.

The surface glass crack preventing material 1 is, for example, polyolefin (polyethylene or polypropylene) / thermoplastic (ethylene-vinyl acetate copolymer) / polyolefin, polyolefin (polyethylene or polypropylene) / polyolefin + thermoplastic elastomer / polyolefin (polyethylene or polyolefin). Propylene), a multilayered body having a compounding ratio of polyolefin + thermoplastic elastomer, polypropylene / polyethylene / polypropylene, nylon / ethylene-vinyl acetate copolymer / nylon, copolymerized nylon / ethylene adhesive / ethylene-vinyl acetate copolymer / ethylene Various multilayer structures, such as adhesive agent / copolymer nylon, can be made. Moreover, it can also be set as the multilayer structure of core / shell type resin which consists of the core of a thermoplastic elastomer, and the shell structure of an acrylic resin.

In the present invention, the surface glass crack preventing material 1 has a function of shielding electromagnetic waves and near infrared rays (800 to 1,200 nm) on its own (for example, a film layer made of the material having the above shock-absorbing property), if necessary, These functions can be provided by adding desired functions such as an antireflection function that reduces external light reflection, a function of adjusting color tone in the visible range, or by providing a member having these functions adjacent to the surface glass crack preventing material 1. It can be set as the glass crack prevention structure added at least one.

For the electromagnetic shielding function, the radiation field strength from a 42-inch PDP monolith is 40 to 50 dBμV / m at 30 to 1,000 MHz, in particular at 30 to 230 MHz, the VCCI limit (10 m method) is 40 dBμV / m for Class A. Hereinafter, considering the margin of 6 to 7 dB, the shielding effect may be 10 dB or more, preferably 20 dB. The surface resistivity required for this is 10 Ω / cm ² or less, preferably 3 Ω / cm ² or less. In addition, the near-infrared shielding function may prevent the malfunction of home appliances or optical communication, and the transmittance of the near infrared rays (800 to 1,200 nm) may be 20% or less, preferably 10% or less.

When a metal mesh or a patterned metal mesh is used for electromagnetic shielding, since the near-infrared transmittance is 20% or less, it is preferable to use many pigment | dyes which consist of a near-infrared absorption dye and a pigment. Alternatively, the near-infrared absorbing dye or pigment is added to an infrared reflecting material obtained by dispersing conductive fine particles made of an indium composite oxide that reflects infrared rays in various resins such as thermoplastic resins, thermosetting resins, ultraviolet rays or electron beam curable resins. It can also be compounded.

Particularly preferred for shielding electromagnetic waves and near-infrared rays is a transparent laminate in which n units (2 ≦ n ≦ 5) are laminated with a metal layer composed of a transparent thin film layer and a silver-based transparent conductor layer as one unit, specifically, a metal layer / transparent thin film layer, It is a transparent laminated body which repeated these 2 or more times based on the structure of a transparent thin film layer / metal layer / transparent thin film layer, or a metal layer / transparent thin film layer / metal layer. These transparent laminates can be installed directly on a film layer made of the above-mentioned shock-absorbing material constituting the surface glass break prevention material 1, and are formed on a transparent substrate separately to form the surface glass break prevention material 1. It can also stick to.

In the above transparent laminate, any material having optical transparency can be widely used as the transparent thin film layer material. The refractive index of a transparent thin film layer can select the thing which is easy to achieve desired optical characteristic in an optical design, and the material and refractive index of each layer of two or more transparent thin film layers may differ, respectively. In addition, it may be a single material or a material obtained by sintering a plurality of materials. Moreover, the material which has the effect of preventing the movement of a metal thin film layer, or water and oxygen barrier effect is more preferable. Preferred materials for such a transparent thin film layer include indium oxide, tin oxide, titanium dioxide, cerium oxide, zirconium oxide, zinc oxide, tantalum oxide, niobium pentoxide, silicon dioxide, silicon nitride, aluminum oxide, magnesium fluoride and magnesium oxide. A species or 2 or more types of compound are mentioned.

Among the above materials of the transparent thin film layer, a small amount of titanium dioxide, tin oxide, cerium oxide, etc. containing indium oxide as a main component is effective in preventing electrical deterioration of the metal thin film layer and having electrical conductivity. desirable. These transparent thin film layers can be formed by a vacuum drying method such as sputtering method, vacuum deposition method, ion plating method, wet method or the like. The sputtering method is most preferable in view of controllability and uniformity of the film thickness. The transparent thin film layer thickness may be 10 to 100 nm.

The metal thin film material consists of silver alone or an alloy containing silver as a main component, and is 80% by weight or more of silver; And a material composed of one or two or more elements selected from gold, copper, palladium, platinum, manganese, and cadmium, but having 80 to 99% by weight of silver and 20 to 1% by weight of the metal. Do. In particular, solid solution of 1 to 20% by weight of gold in silver is preferable from the viewpoint of preventing deterioration of silver. Incorporation of more than 20% by weight of gold tends to impair transparency due to coloring, and less than 1% by weight of silver tends to occur. As a means for forming a silver transparent conductor film, vacuum drying methods, such as sputtering, can be used. The thickness of the silver transparent conductor film is preferably 1 to 30 nm, more preferably 5 to 20 nm.

According to the transparent laminate formed of the transparent thin film layer and the metal thin film layer, the electromagnetic shielding effect can be easily set to 10 dB or more, the near infrared (800 to 1,200 nm) transmittance of 20% or less, and the visible light transmittance can be maintained at 30% or more. . In addition, in order to increase the adhesion to the adherend, such as a transparent substrate to form a transparent laminate, a separate metal layer is formed on the adherend to a thickness of 10 nm or less that does not reduce the transparency, or the corona treatment, plasma on the adherend surface A well-known reverse adhesion process, such as a process, can also be performed. Further, in order to reduce the reflectance, a low refractive index layer having a refractive index of 1.50 or less may be formed between the adherends with an optical thickness of λ / 4n ± 15%.

In addition, in order to obtain an electromagnetic wave shielding effect, an electrode is provided in an electromagnetic wave shielding layer such as a transparent laminate or a metal mesh and electrically connected to the PDP housing or the like. The electrode material is preferably excellent in conductivity, corrosion resistance, moisture resistance, moisture resistance, and adhesion to a shielding layer. Specifically, one or more metals selected from silver paste, gold, silver, copper, platinum, palladium, and the like alloy; Mixing the same metal or alloy with an organic coating material; A conductive double-sided tape etc. which are manufactured by impregnating an adhesive in a copper mesh, etc. are mentioned. Electrodes made of such a material can be formed by directly adhering to the four sides of the electromagnetic shielding layer in a conductive double-sided tape, and wet methods such as screen printing and microgravure coating methods in silver paste, various alloy materials, and alloy mixed materials; Dry methods such as vacuum deposition and sputtering; It can be formed by a plating method or the like.

In addition, in the antireflection function for reducing the reflection of external light and the like, in order to suppress deterioration of the image display of the PDP, antireflection treatment is performed in which the visible light reflectance is 5% or less, preferably 4% or less, or as haze prevention The anti-glare treatment which becomes 5% or less can be performed. In addition, the antifouling treatment can be performed on these treatment surfaces to prevent dirt, such as fingerprints. Moreover, as a surface protection function, the hard-coating process which surface (pencil) hardness becomes H or more can also be given. Further, in order to achieve good image display of the PDP, dye materials such as dyes and pigments may be used to adjust the color in the visible region. These treatments can be carried out directly on the film layer made of the material having the impact relieving property constituting the surface glass crack preventing material 1, and the transparent functional film subjected to the treatment is produced in advance and the surface glass crack preventing material ( It can also stick to 1).

In the anti-reflection treatment, a low refractive index layer having a refractive index of less than 1.50, preferably 1.45 or less can be formed. An inorganic or organic material having good visible light transmittance, durability, adhesion and the like is used here. Examples of the organic material include a fluorine-containing polymer obtained by polymerizing fluoroethylene, vinylidene fluoride, tetrafluoroethylene and the like; Partial or fully fluorinated alkyl esters of (meth) acrylic acid; And fluorine-containing silicones. Examples of the inorganic material include MgF ₂ , CaF ₂ , and SiO ₂ . The low refractive index layer may be wetted such as microgravure coating; It can form by dry methods, such as a vacuum vapor deposition method and a sputtering method. It is preferable that the thickness of this low refractive index layer is 1 micrometer or less normally, and it is more preferable that it is 0.5 micrometer or less.

In addition, an antifouling treatment layer may be further provided on the low refractive index layer. Examples of the antifouling treatment layer material include a cured product made of an organic polysiloxane polymer and a perfluoroalkyl-containing polymer; An alkoxy silane compound having a perfluoroalkyl group; Compounds having a perfluoropolyether group and a reactive silyl group; And monosilane or disilane compounds containing polyfluoroalkyl groups. The thickness of the anti-fouling treatment layer is preferably 0.001 to 0.5 µm, and more preferably 0.002 to 0.1 µm.

In addition, a high refractive index layer (to a high refractive index antiglare layer) having a refractive index of 1.5 or more, preferably 1.6 or more may be formed as an antireflection treatment different from the above. An inorganic or organic material having good visible light transmittance, durability, adhesion and the like is used here. As an organic type material, multifunctional compounds containing two or more (meth) acryloyl groups, such as a urethane (meth) acrylate, polyester (meth) acrylate, and polyether (meth) acrylate, are active energy, such as an ultraviolet-ray and an electron beam. Polymer-cured by wire; Or crosslinking-curing a crosslinkable resin raw material of silicone, melamine or epoxy type with heat. Inorganic materials include indium oxide as a main component, titanium dioxide, tin oxide or cerium oxide in small amounts, and CeF ₃ , Al ₂ O ₃ , MgO, TiO ₂ , ZnO and the like. Further, inorganic fine particles made of metal oxide particles such as aluminum, titanium, zirconium, antimony and the like may be dispersed in the organic material. Such a high refractive index layer (or a high refractive index antiglare layer) can be formed by a wet method such as a microgravure coating method or a dry method such as a vacuum deposition method or a sputtering method. It is preferable that the thickness of the said layer is 50 micrometers or less, and it is more preferable that it is 10 micrometers or less.

In the hard coating treatment, an ultraviolet curing type material, an electron beam curing type material or a thermosetting type material is used. The ultraviolet curing type includes a material in which a photopolymerization initiator is mixed with monomers and oligomers such as esters, acrylics, urethanes, acrylic urethanes, amides, silicones, epoxys, and acrylics and epoxides. In the electron beam curing type, the mixing of the photopolymerization initiator is unnecessary. The thermosetting type includes a material in which a crosslinking agent, a polymerization initiator, a polymerization accelerator, a solvent, a viscosity modifier, and the like are mixed with resins such as phenolic, urea, melamine, unsaturated polyester, polyurethane, and epoxy, as necessary. . Furthermore, inorganic / organic hybrid resin which chemically bonded silicone resin with acrylic resin; The material which disperse | distributed inorganic fine particles, such as a silicon oxide, a zirconia oxide, an indium tin oxide, a tin oxide, in the said resin to the extent which does not impair transparency can also be used. To these materials, an additive containing a carboxyl group, a phosphoric acid group, a hydroxyl group, an amino group, an isocyanate group, or the like may be added to increase adhesion to the adherend, and a leveling agent, an antistatic agent, an ultraviolet absorber, or the like may be added. . 0.1-20 micrometers is suitable for the thickness of a hard-coat layer, and it is more preferable that it is 1-10 micrometers.

In the present invention, a transparent protective layer having good mechanical strength, heat resistance, or the like is further provided on the exposed surface side of the surface glass crack preventing material 1 in order to prevent scattering of the glass when the PDP panel is destroyed. It can also be set as the structure arrange | positioned 2 or more layers. As such a transparent protective layer, polyester resin, (meth) acrylic resin, polycarbonate resin, polyethylene naphthalate resin, polyethylene terephthalate resin, triacetyl cellulose, atone resin, epoxy resin, polyimide resin, polyetherimide resin, polyamide A film made of resin, polysulfone, polyphenylene sulfide, polyether sulfone, or the like, a molded plate, or a glass plate having scattering resistance can be used.

In the present invention, the glass substrate may be used for plasma display devices such as soda-lime glass and high strain point glass, but is not particularly limited. The thickness of the glass substrate is usually about 0.5 to 5 mm. In addition, the structure of a glass substrate may be single-layered constitution of one piece of glass, and multilayer constitutions, such as two pieces of glass, may be sufficient as it. In a large display device, a double glass structure composed of two glass plates is usually used as in a PDP panel.

In this invention, a metal plate is arrange | positioned inside a glass substrate in display apparatuses, such as a PDP, and fulfills functions, such as fixing of various components or a glass substrate. The kind of metal is not specifically limited, Any thing used for PDP etc. can be used. In the case of a display device, since hardness, strength, etc. are required, materials, such as aluminum or its alloy type, stainless type, are used preferably. The thickness is not limited and may be a thickness used in the display device.

In the present invention, the surface glass crack preventing material (1), the glass substrate and the metal plate are arranged in this order, and the inner glass crack preventing material (2) having a specific configuration is further provided between the glass substrate and the metal plate with this as a basic configuration. It is a big feature to interpose, and the glass shatterproof effect can be improved significantly compared with the glass shatterproof structure which is not interposed by this.

The inner glass crack preventing material 2 is made of an elastic or viscoelastic material having a dynamic shear modulus of 1 × 10 ⁹ Pa or less, and preferably has a thickness of 0.01 to 50 mm. When the dynamic shear modulus exceeds the above value, the impact relieving property is poor, and it is difficult to improve the glass breaking effect. The above-mentioned "dynamic shear modulus" is a measurement of the dynamic shear modulus (G) at 25 ± 3 ° C under a fixed condition of frequency 1 Hz using a dynamic viscoelasticity measuring device DMS 120 manufactured by Seiko Instruments Co., Ltd. (dynamic storage Shear elastic modulus (G '). In general, there is a relationship between tensile modulus and E = 3G (dynamic shear modulus), and tensile modulus (E) is about three times the dynamic shear modulus (G).

Since the inner glass crack preventing material 2 is provided inside the glass substrate, i.e., on the back side of the image display of the PDP panel, unlike the surface glass crack preventing material 1, transparency is not necessary and has the dynamic shear modulus. It can be used widely if it is a material which consists of an elastic body or viscoelastic body. As such a material, first, adhesives, such as an acryl type, rubber type, and polyester type, especially an acrylic type adhesive, are used preferably. The acrylic pressure-sensitive adhesive is an acrylic polymer containing an appropriate additive as necessary, and may be a thermal crosslinking type or a light (ultraviolet or electron beam) crosslinking type in addition to the non-crosslinking type.

The acrylic polymer mainly contains one or two or more kinds of (meth) acrylic acid alkyl esters having a glass transition point (Tg) of 60 ° C. or lower, in order to impart proper wettability or flexibility, and a functional group-containing monomer or the like, if necessary. One or two or more types of copolymerizable monomers are obtained by polymerizing by a polymerization method such as solution polymerization, emulsion polymerization, bulk polymerization (particularly by ultraviolet irradiation), suspension polymerization or the like using an appropriate polymerization catalyst. Will be.

In addition to the pressure-sensitive adhesive, natural polymer glue, starch, semi-synthetic polymer cellulose acetate, synthetic polymer polyvinyl acetate, polyvinyl chloride, epoxy resin, urethane resin, polychloroprene, acrylonitrile-butadiene copolymer, melamine resin, acrylic Adhesives based on resins, ethylene-vinyl acetate copolymers, polyester resins, polyamide resins, and the like can also be used. These may be used as adhesives of various curing types such as room temperature curing, heat curing, ultraviolet ray, electron beam or laser irradiation curing type.

Moreover, polyester resin, (meth) acrylic resin, polycarbonate resin, triacetyl cellulose, atone resin, epoxy resin, polyimide resin, polyetherimide as a resin material which is excellent in shock resistance and excellent in mechanical strength, heat resistance, etc. Resins, polyamide resins, polysulfones, polyphenylene sulfides, polyethersulfones and the like can also be used.

Furthermore, ionomer resin which bridge | crosslinked the molecule | numerator of ethylene-methacrylic-acid copolymer with metal ion (Na ⁺ , Zn2 ⁺ etc.) as materials other than these; Thermoplastic resins such as ethylene-vinyl acetate copolymer, polyvinyl chloride resin, ethylene-acrylate copolymer, polyethylene, polypropylene, polybutyral resin and polystyrene resin; Or polystyrene-based, polyolefin-based, polydiene-based, polyvinyl chloride-based, polyurethane-based, polyester-based, polyamide-based, fluorine-based, chlorinated polyethylene-based, polynorbornene-based, polystyrene-polyolefin-based copolymer, (hydrogenated) polystyrene Thermoplastic elastomers, such as butadiene type copolymer and a polystyrene vinyl polyisoprene type copolymer, are used. In addition, what mix | blended the said thermoplastic elastomer with polyolefin, such as polyethylene and a polypropylene, etc. are used.

In addition, as a combination structure of the above materials, polyolefin (polyethylene or polypropylene) / thermoplastic (ethylene-vinyl acetate copolymer) / polyolefin, polyolefin (polyethylene or polypropylene) / polyolefin + thermoplastic elastomer / polyolefin (polyethylene or polypropylene) , Polypropylene + polyethylene / polypropylene, nylon / ethylene-vinyl acetate copolymer / nylon, copolymerized nylon / ethylene-based adhesive / ethylene-vinyl acetate copolymer / ethylene-based adhesive / Various multilayer structures, such as copolymerized nylon, can also be used. Moreover, it can also be set as the multilayer structure of the core / shell type resin which consists of the core of a thermoplastic elastomer, and the shell structure of an acrylic resin.

As the rubber material, natural or synthetic fluorine, silicone, acrylic, ethylene-acrylic, chlorinated polyethylene, olefin, urethane, epichlorohydrin, chlorosulfonated polyethylene, acrylonitrile-butadiene, nitrile rubber, One kind or two or more kinds of styrene-butadiene rubber series, polyvinyl chloride series, and ethylene-propylene-diene terpolymer series can be used. These may be either vulcanized or unvulcanized. Moreover, as a material of that excepting the above, acryl type, urethane type, silicone type, etc. can also be used as various gel materials, The kind of material is not specifically limited.

The inner glass crack preventing material 2 includes various additives, inorganic fillers, antioxidants, antioxidants, ultraviolet absorbers for imparting flame retardancy or thermal conductivity to the resin material or rubber material composed of the above-mentioned elastomer or viscoelastic material as necessary. Various compounding agents, such as a lubricating agent, a softener, a pigment, a crosslinking agent, a vulcanizing agent, a coloring agent, a plasticizer, a mold release agent, a preservative, a coupling agent, oil, can also be added.

The internal glass crack prevention material 2 may be interposed over the whole surface between a glass substrate and a metal plate, and may be partially interposed. As a form, Forms, such as a sheet and a film; Amorphous materials such as liquid phase and gel phase; And combinations thereof, and the amorphous form is interposed so as not to leak between the above. It can also be used by impregnating a nonwoven fabric etc. as needed. The layer structure may be a single layer or a multi-layer, and in the case of a multi-layer, even when the dynamic shear modulus exceeds 1 × 10 ⁹ Pa, the multi-layer can be used in the present invention as long as it is equal to or less than the above value. When adhesiveness with respect to a glass substrate or a metal plate is required and this cannot be satisfied, you may perform appropriate adhesive provision process to one side or both surfaces. In addition, when the inner glass crack preventing material 2 needs to fix or maintain the glass substrate and the metal plate, it may be mechanically fixed or maintained using screws, springs, etc., rather than adhesives or adhesives.

The glass crack prevention structure of this invention which consists of the above components can be made by arbitrary methods according to the kind, composition, etc. of each component, and the manufacturing method is not limited. For example, the surface glass crack prevention material 1 which used the adhesive etc. was laminated | stacked on the surface side of a glass substrate, and the metal plate is adhere | attached on the back surface side through the internal glass crack prevention material 2 which consists of an adhesive etc. Method and the like.

The glass crack preventing structure of the present invention composed of the above components has a structure in which the transparent surface glass crack preventing material 1 is directly adhered to the glass substrate, and thus there is no air layer between the glass substrate and the surface glass crack preventing material 1. Therefore, there is no problem such as double glazing of external light, and can be used as a glass crack preventing structure that can be reduced in weight and thickness, and at the same time, a large glass crack is prevented by the inner glass crack preventing material 2 interposed between the glass substrate and the metal plate. The effect can be obtained.

That is, the glass breakage prevention structure of the present invention has a fracture impact energy (B) in which a glass substrate is broken when a steel sphere having a diameter of 50 mm and a weight of 500 g is dropped on the surface glass breakage prevention material (1). Except for not interposing the ashes 2, the breakage impact energy A of the glass crack preventing structure having the same structure is increased to 1.2 times or more, preferably 1.5 times or more, so that the breakage of the glass substrate due to external impact is considerably increased. It is difficult to happen.

For this reason, the glass shatterproof structure of this invention is especially suitable for PDP, The PDP apparatus which has this glass shatterproof structure is a reflection which reduces the shielding function of electromagnetic waves or near-infrared rays, and the reflection of external light to the surface glass shatterproof material 1 By adding a prevention function, a function of adjusting the color of the visible region, or the like, or by installing a member having these functions adjacent to the surface glass crack prevention material 1, the PDP apparatus having the above-described advantages as well as the above-described respective functions is further added. It can be used as.

Example

Next, examples of the present invention will be described in more detail. In addition, what is negative in the following shall mean a weight part. In addition, the dynamic shear elastic modulus of the surface glass crack prevention material 1 and the internal glass crack prevention material 2 is measured in the sample 5 mm x 10 mm in size by the method as described in a main body.

Example 1

The main component is an acrylic polymer having 2-ethylhexyl acrylate as a main monomer on the back side of a polyethylene terephthalate film (trade name "rear look 1200" manufactured by Nippon Yushi Co., Ltd.) subjected to antireflection so that the reflectance is 4% or less. An ultraviolet curable acrylic pressure sensitive adhesive (dynamic shear modulus: 3 × 10 ⁴ Pa) having a glass transition point (Tg) of about 40 ° C. was applied to form a surface glass crack preventing material 1 having a thickness of 1 mm.

Two pieces of high strain point glass ["PD 200" by Asahi Glass Co., Ltd., thickness 2.8mm] of 30cm * 30cm are used as a glass substrate, and glass paste ["ASF 2300A" by Asahi Glass Co., Ltd. product) 4 sides were fixed, and plastic bonding was carried out so that thickness might be about 150 micrometers and width about 5 mm, and the surrogate model of the PDP panel was produced. The surface glass crack prevention material 1 was stuck on this.

In contrast, an aluminum sheet having a thickness of 1 mm is used as the metal plate, and an ultraviolet curable acrylic system having a glass transition point (Tg) having a main component of an acrylic polymer containing 2-ethylhexyl acrylate as the main monomer is about 40 ° C. An adhesive (dynamic shear modulus: 3 × 10 ⁴ Pa) was applied to form an inner glass crack preventing material 2 having a thickness of 1 mm. The glass cracking prevention structure was created by sticking the surface opposite to the surface glass cracking prevention material 1 of the said glass substrate on this internal glass cracking prevention material 2.

Comparative Example 1

According to Example 1, a glass crack preventing structure was formed except that the inner glass crack preventing material 2 was not formed.

Comparative Example 2

According to Example 1, a glass crack prevention structure was produced except that the inner glass crack preventing material 2 was composed of a polyethylene terephthalate film having a thickness of 1 mm (dynamic shear modulus: 2 × 10 ⁹ Pa).

Example 2

According to Example 1, a glass crack preventing structure was formed except that the thickness of the surface glass crack preventing material 1 was 2 mm.

Example 3

According to Example 1, a glass crack preventing structure was formed except that the thickness of the surface glass crack preventing material 1 was 3 mm.

Example 4

As the inner glass crack preventing material (2), an ultraviolet curable acrylic pressure sensitive adhesive (dynamic shear modulus: 1 × 10 ⁶ Pa) having a glass transition point (Tg) mainly composed of a copolymer of isononyl acrylate and acrylic acid as about −20 ° C. was used. According to Example 1, the glass crack prevention structure was created except having used to make thickness 1mm.

Example 5

Example 1 except that the inner glass crack preventing material 2 was made to have a thickness of 1 mm by using sulfur-free modified urethane ("DUS 605" manufactured by Shidome Co., Ltd., dynamic shear modulus: 7 x 10 ⁷ Pa). According to the present invention, a glass crack prevention structure was made.

Example 6

100 parts of ethylene-propylene-diene terpolymers ("EPDM 4021" by Mitsui Chemicals Co., Ltd.) as the internal glass crack preventing material (2), 3 parts of carbon ["# 50" by Asahi Carbon Co., Ltd.), 3 parts of stearic acid (manufactured by Nippon Yushi Co., Ltd.), 500 parts of aluminum hydroxide ["Hyzilite H-34" manufactured by Showa Denko Co., Ltd.) and paraffinic oil ("Diana of Idemitsu Kosan Co., Ltd.") Process PW-380 "] The compound consisting of 80 parts was kneaded with a pressure kneader and rolled with a calender roll to obtain a thickness of 1 mm using an unvulcanized rubber material (dynamic shear modulus: 2 x 10 ⁶ Pa). According to Example 1, a glass crack preventing structure was made.

Example 7

A glass crack preventing structure was made in accordance with Example 1 except that a 42-inch actual PDP panel was used as the glass substrate.

Dropping height (cm) of the steel ball when the glass substrate was broken by performing a steel ball drop test according to the following method for each of the glass crack preventing structures of Examples 1 to 7 and Comparative Examples 1 and 2, and breaking at that time Impact energy (J) was measured. These results were as showing in Table 1. In addition, in Table 1, the dynamic shear modulus of the glass crack preventing material (1) and (2) is described together for reference.

<Steel ball drop test>

Each glass shatterproof structure was placed directly on the floor with the surface glass shatterproof material 1 on the upper side and electromagnet fixed in its upper position at the center of the surface glass shatterproof material 1 with a weight of 500 g of copper. The height until the sphere was dropped and the glass substrate was broken was measured at 1 cm intervals. As a crack evaluation, it confirmed visually whether the crack and the crack generate | occur | produced in a glass substrate.

As apparent from the above results, according to the glass break preventing structure of Examples 1 to 7 of the present invention, the fracture impact of 1.2 times or more larger than that of the glass break preventing structure of Comparative Example 1 in which the inner glass break preventing material 2 was not formed. It can be seen that the energy is increased and the glass breaking effect is increased. In addition, in the glass break prevention structure of the comparative example 2 which used the material whose dynamic shear modulus exceeded 1x10 <^9> Pa as internal glass break prevention material 2, the said glass break prevention effect cannot be acquired.

As described above, the present invention arranges the surface glass crack preventing material (1), the glass substrate and the metal plate in this order, and is composed of an elastomer or a viscoelastic body having a dynamic shear modulus of 1 × 10 ⁹ Pa or less between the glass substrate and the metal plate. By interposing the inner glass crack preventing material (2), unlike the conventional PDP front panel, there is no air layer, so there is no double glazing of external light, it is possible to reduce the weight and thickness, and to prevent the glass cracking effect, and to shield electromagnetic waves and near infrared rays. It is possible to provide a glass crack preventing structure that can be arbitrarily added, and a PDP device employing the same.

Claims (3)

In the glass-breaking structure in which the surface glass-breaking preventing material 1, the glass substrate and the metal plate are arranged in this order, the internal glass cracking made of an elastomer or viscoelastic material having a dynamic shear modulus of 1 × 10 ⁹ Pa or less between the glass substrate and the metal plate. The glass crack prevention structure characterized by interposing the prevention material (2). The method of claim 1, Except that the impact glass (B) that breaks the glass substrate when the steel ball having a diameter of 50 mm and a weight of 500 g is dropped on the surface glass crack preventing material 1 does not interpose the inner glass crack preventing material 2. The glass break prevention structure which is 1.2 times or more of the said breaking impact energy (A) with respect to the glass break prevention structure which has the same structure. A plasma display device having the glass crack preventing structure according to claim 1.