JP2009061623A - Method for obtaining composite body by bonding light shielding film and opaque substrate with photo-setting adhesive resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for bonding a light shielding film and an opaque substrate by sufficiently setting a photo-setting adhesive resin under the light shielding film by only photoirradiation. <P>SOLUTION: The method for obtaining the composite body by bonding the light shielding film and the opaque substrate by photo-setting via the photo-setting adhesive resin is characterized in that the light shielding film is formed from the photo-setting light shielding resin composition containing a compound having a refractive index of ≥0.01 in the difference between with refractive indices of the photo-setting resin and the set matter of the photo-setting resin, and having incompatibility and dispersibility with/in the photo-setting resin. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method of obtaining a composite by bonding a light-shielding film and an opaque substrate by photocuring through a photocurable adhesive resin, and in particular, a light-shielding frame and a display panel on a transparent front plate are bonded to a photocurable adhesive resin. It is related with the method of bonding by photocuring through and obtaining a composite.

  Conventionally, to protect display panels such as mobile phones, PDAs, digital cameras, video LCDs, EL displays, and LED displays from external impacts, transparent front plates such as acrylic plates and glass plates are used as display panels. It was arranged with a space in front of it, and the periphery was fixed with an adhesive tape or an adhesive.

  In recent years, a method of directly bonding a front plate and a display panel with a transparent photo-curing adhesive resin has been taken for the purpose of improving display characteristics such as luminance and contrast and reducing the thickness. The front plate may be provided with a light-shielding frame by printing or the like in order to conceal the display element driving IC, wiring, and LCD frame sealant so that only the display area is visible and to improve the design. When this light shielding frame is present, the photocurable adhesive resin under the light shielding frame is blocked by light by the light shielding frame and is not cured without being exposed to light, resulting in insufficient adhesion.

  In order to solve this problem of insufficient adhesion due to uncured, a method of adjusting the light irradiation angle by irradiating light obliquely or from the side, or adding a thermosetting catalyst to the photocurable adhesive resin, In addition to curability, a method of imparting a thermosetting function and curing with light and heat has been performed.

  However, in the method of adjusting the light irradiation angle, if the width of the light shielding frame is widened, it becomes difficult to sufficiently cure all of the photocurable adhesive resin under the light shielding frame, and uncured portions are likely to remain. was there. Moreover, in the method of giving a thermosetting function to a photocurable adhesive resin and curing with light and heat, it is necessary to heat a display panel such as an LCD, an EL display, and an LED display at 60 to 80 ° C. for 30 to 60 minutes. For this reason, there is a problem in that there is a possibility that the quality is deteriorated and the product life is shortened.

  Therefore, the present invention has a problem that an uncured portion tends to remain when a photocurable adhesive resin under a light shielding film (especially a light shielding frame of a front plate) is cured, and an opaque substrate (particularly a display panel) due to heat curing. Solves the problem of deterioration of quality and the possibility of shortening the product life, and applies the photo-curable adhesive resin under the light shielding film (especially the light shielding frame on the front plate) from the top of the light shielding film (especially the light shielding frame on the front plate). It is an object of the present invention to provide a method for obtaining a composite by sufficiently curing only by light irradiation and adhering a light shielding film (especially a light shielding frame of a front plate) and an opaque substrate (particularly a display panel).

  As a result of diligent study to solve the above problems and achieve the above object, the inventor has found that the light shielding film formed from the specific photocurable light shielding resin composition has sufficient light shielding performance, and this light shielding. The present invention was completed by discovering that the film was sufficiently adhered to the opaque substrate by light irradiation from the upper part of the light-shielding film by the photocurable adhesive resin.

The present invention
(1) A method in which a light-shielding film and an opaque substrate are bonded by photocuring via a photocurable adhesive resin to obtain a composite, wherein the light-shielding film comprises a photocurable resin and a cured product of the photocurable resin. It is formed from a photocurable light-shielding resin composition containing a compound having a refractive index such that a difference in refractive index from the refractive index is 0.01 or more, and being incompatible with the photocurable resin and having dispersibility. A method characterized by:
(2) The method according to (1), wherein the light shielding film is a light shielding frame on a transparent front plate, and the opaque substrate is a display panel;
(3) The transparent front plate is a sheet or film made of acrylic resin, polycarbonate resin, polyester resin, COP cycloolefin polymer or COC cycloolefin copolymer, or a glass plate or a tempered glass plate (1) or (2) The method according to the description;
(4) The method according to any one of (1) to (3), wherein the display panel is an LCD, an EL display, an LED display, or electronic paper;
(5) The refractive index difference between the photocurable resin and the cured product of the photocurable resin is 0.01 or more, and is incompatible with the photocurable resin. A light-shielding film formed from a photocurable light-shielding resin composition containing a compound having dispersibility;
(6) A front panel for a display panel having the light shielding film according to (5) as a light shielding frame;
(7) A display panel having the front plate according to (6).

  According to the present invention, a light-shielding film having a sufficient light-shielding property (particularly a light-shielding frame having a sufficient light-shielding property on the front plate) and an opaque substrate (particularly a display panel) are combined with a light-shielding film (especially a light-shielding film frame on the front plate). ) Can be bonded only by light irradiation from the upper part, so that the manufacturing operation of the composite of the obtained light-shielding film (especially the light-shielding frame on the front plate) and the opaque substrate (particularly the display panel) can be simplified. There is no risk of quality degradation or shortening of product life.

  The photocurable light-shielding resin composition in the present invention provides a light-shielding cured product, that is, a light-shielding film when cured. The photocurable light-shielding resin composition has a refractive index such that a difference in refractive index between a photocurable resin as a base resin and a refractive index of a cured product of the photocurable resin is 0.01 or more, And a compound that is incompatible with the photocurable resin and has dispersibility (hereinafter sometimes referred to as “light-shielding compound”).

  The base resin means a resin that forms a continuous phase of the photocurable light-shielding resin composition. Therefore, a continuous phase can be formed even in a cured product obtained by curing the photocurable light-shielding resin composition. The photocurable resin that is the base resin is not particularly limited as long as it is a resin that is cured by light such as visible light and ultraviolet light. For example, (meth) acrylic resin, urethane acrylate resin, polyester acrylate resin, epoxy resin, oxetane resin Is mentioned. As a photocurable resin, Preferably, an acrylic modified resin and an epoxy resin are mentioned.

  The acrylic-modified resin is defined as a monofunctional and polyfunctional (meth) acrylate compound having an acryloyl group or a methacryloyl group. For example, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, t-butyl Acrylate, isobutyl acrylate, ethyl hexyl acrylate, isodecyl acrylate, n-hexyl acrylate, stearyl acrylate, lauryl acrylate, tridecyl acrylate, ethoxyethyl acrylate, methoxyethyl acrylate, glycidyl acrylate, butoxyethyl acrylate, 2-hydroxyethyl acrylate, 2- Hydroxypropyl acrylate, 2-methoxyethyl acrylate, 2-ethoxyethoxyethyl acrylate Methoxydiethylene glycol acrylate, ethoxydiethylene glycol acrylate, methoxydipropylene glycol acrylate, octafluoropentyl acrylate, N, N-dimethylaminoethyl acrylate, N, N-diethylaminoethyl acrylate, allyl acrylate, 1,3-butanediol acrylate, 1 , 4-butanediol acrylate, acryloyl morpholine, 1,6-hexanediol acrylate, polyethylene glycol diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, tripropylene glycol diacrylate, hydroxypivalate ester Neopentyl glycol diacrylate Trimethylolpropane diacrylate, 1,3-bis (hydroxyethyl) -5,5-dimethylhydantoin, 3-methylpentanediol acrylate, α, ω-diacrylbisdiethylene glycol phthalate, trimethylolpropane triacrylate, pentaerythritol acrylate Pentaerythritol hexaacrylate, dipentaerythritol monohydroxypentaacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, tri (meth) acrylate of trihydroxyethyl isocyanurate, dipentaerythritol hexaacrylate, and their EO and / or Or PO adduct, α, ω-tetraallylbistrimethylolpropane tetrahydrophthalate, 2-hydroxy ester Ruacryloyl phosphate, trimethylolpropane trimethacrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1, Examples thereof include 6-hexanediol di (meth) acrylate, neopentylglycol dimethacrylate, diacryloxyethyl phosphate, N-vinylpyrrolidone and oligomers having these photoreactive functional groups.

  The epoxy resin is defined as a compound having a molecular structure having one or more epoxy groups, for example, biphenol, bisphenol A, hydrogenated bisphenol A, bisphenol F, bisphenol AD, bisphenol S, tetramethylbisphenol A, tetramethylbisphenol F. Diglycidyl ethers of bisphenols such as tetrachlorobisphenol A and tetrabromobisphenol A, polyglycidyl ethers of novolac resins such as phenol novolak, cresol novolak, brominated phenol novolak, orthocresol novolak, ethylene glycol, polyethylene glycol, Polypropylene glycol, butanediol, 1,6-hexanediol, neopentyl glycol, trimethylolpropane, 1 Diglycidyl ethers of alkylene glycols such as 4-cyclohexanedimethanol, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, glycidyl such as glycidyl ester of hexahydrophthalic acid and diglycidyl ester of dimer acid Esters, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, 3,4-epoxycyclohexylethyl-3 ′, 4′-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methyl Cyclohexyl-3 ′, 4′-epoxy-6′-methylcyclohexanecarboxylate, vinylcyclohexene dioxide, 3,4-epoxy-4-methylcyclohexyl-2-propylene oxide, -(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-m-dioxane, bis (3,4-epoxycyclohexyl) adipate, bis (3,4-epoxycyclohexylmethyl) adipate, Lactone modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, methylene bis (3,4-epoxycyclohexane), ethylene bis (3,4-epoxycyclohexanecarboxylate), dicyclopentadiene diepoxide, Bis (3,4-epoxycyclohexyl) ether, bis (3,4-epoxycyclohexylmethyl) ether, tetra (3,4-epoxycyclohexylmethyl) butanetetracarboxylate, bis (3,4-epoxycyclohexyl) Examples thereof include alicyclic epoxy compounds such as (silmethyl) -4,5-epoxytetrahydrophthalate and bis (3,4-epoxycyclohexyl) diethylsiloxane, and oligomers having these photoreactive functional groups.

  The photocurable resin is not particularly limited by the refractive index after curing, and a photocurable resin that gives a cured product having an arbitrary refractive index can be used. The refractive index of the cured product of the photocurable resin is measured by D-line using an Abbe refractometer (manufactured by Atago Co., Ltd.). The photocurable resin is selected from the above resins as one or a mixture of two or more in consideration of the performance required at the site to be used.

  The photocurable light shielding resin composition in the present invention may contain a photopolymerization initiator. Photopolymerization initiators include generally commercially available radical or cationic initiators, such as carbonyl groups: benzophenone, diacetyl, benzyl, benzoin, ω-bromoacetophenone, chloroacetone, acetophenone, 2,2 -Diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetone, p-dimethylaminoacetophenone, p-dimethylaminopropiophenone, 2-chlorobenzophenone, p, p'-bisdiethylaminobenzophenone, Michler's ketone, benzoin methyl ether, Benzoin isobutyl ether, benzoin-n-butyl ether, benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-one, 1- (4-isopropyl Phenyl) -2-hydroxy-2-methylpropan-1-one, methylbenzoylformate, 2,2-diethoxyacetophenone, 4-N, N′-dimethylacetophenones; sulfide systems: diphenyl disulfide, dibenzyl disulfide; Examples include quinone series: benzoquinone, anthraquinone; azo series: azobisisobutyronitrile, 2,2′-azobispropane. A photoinitiator can be used in the quantity generally used, for example, the quantity of 1-10 weight part with respect to 100 weight part of photocurable resins. Irradiation light may be either visible light or ultraviolet light.

  Light-shielding compound (compound having a refractive index such that the difference in refractive index from the refractive index of the cured product of the photocurable resin is 0.01 or more, incompatible with the photocurable resin, and dispersible ) Is selected based on the refractive index of the cured product of the photocurable resin, and the incompatibility and dispersibility of the photocurable resin, and the refractive index is 0.01 or more larger than the refractive index of the cured product of the photocurable resin. The compound is roughly classified into a compound having a refractive index (high refractive index compound) and a compound having a refractive index smaller by 0.01 or more than the refractive index of the cured product of the photocurable resin (low refractive index compound). Compounds having different refractive indexes are organic compounds or inorganic compounds.

  “Incompatible” with the photocurable resin means that it does not dissolve uniformly with the photocurable resin, and “dispersible” with respect to the photocurable resin means immediately after stirring. It means not to separate into two layers.

Examples of the inorganic compound having a refractive index of 0.01 or more different from the base resin that can be used in the present invention include ZnO, TiO ₂ , CeO ₂ , Sb ₂ O ₅ , SnO ₂ , ITO, Y ₂ O ₃ , La ₂ O ₃ , ZrO ₂ , Al ₂ O ₃ , silica, opal, glass and white carbon are included, and preferred examples include alumina, a titanium compound and a zirconia compound having a refractive index of 1.60 or more. The surface of the inorganic compound may be coated with various inorganic / organic compounds. Further, the shape of the inorganic compound may be any shape such as a spherical shape, a needle shape, or a plate shape, and the particle diameter is not limited, but a smaller particle diameter is more preferable. The particle diameter is preferably 0.1 to 100 μm, more preferably 0.1 to 10 μm, and particularly 0.1 to 1 μm.

  The organic compound having a refractive index different by 0.01 or more from the base resin that can be used in the present invention may be any of a liquid or solid monomer, oligomer, or polymer compound, and may be a thermoplastic resin, a thermosetting resin, light. There is no problem with any of the curable resins, but it must be incompatible with the photocurable resin as the base resin and have good dispersibility. For example, (meth) acrylic resin, urethane acrylate resin, polyester acrylate resin, epoxy resin, oxetane resin, polystyrene resin such as polystyrene, polyethylene terephthalate, polyvinyl carbazole, polycarbonate of bisphenol A, polyvinyl chloride, polytetrabromobisphenol A glycidyl Ether, polybisphenol S glycidyl ether, polyvinyl pyridine, thiourethane resin, thioepoxy resin, fluorine-containing (meth) acrylates, fluorinated alkylene ether oligomers (average molecular weight: 4000 or less) monofunctional and bifunctional or more polyfunctional Crystalline polymers such as (meth) acrylates, silicon-containing (meth) acrylates, polyethylene and polytetrafluoroethylene are included.When the organic compound is solid, the shape thereof may be any shape such as a spherical shape, a needle shape, or a plate shape, and the particle size is not limited, but a smaller particle size is preferable. The particle diameter is preferably 0.1 to 100 μm, more preferably 0.1 to 10 μm, and particularly 0.1 to 1 μm. When the organic compound is in a liquid state, the compound is dispersed in a photocurable resin. The particle diameter of the dispersed particles is preferably 0.1 to 100 μm, more preferably 0.1 to 10 μm, particularly 0.1 to 1 μm.

The refractive index of some of the light-shielding compounds that can be used in the present invention is exemplified below.
ZnO (refractive index 1.90), TiO ₂ (refractive index 2.3 to 2.7), CeO ₂ (refractive index 1.95), Sb ₂ O ₅ (refractive index 1.71), SnO ₂ , ITO ( Refractive index 1.95), Y ₂ O ₃ (refractive index 1.87), La ₂ O ₃ (refractive index 1.95), ZrO ₂ (refractive index 2.05), Al ₂ O ₃ (refractive index 1. 63), melamine resin (1.6), nylon (1.53), polystyrene (1.6), polyethylene (1.53), polytetrafluoroethylene (1.35), methyl methacrylate resin (1.49) ), Vinyl chloride resin (1.54), silicone oil (1.4)

  The photocurable light-shielding resin composition in the present invention may contain one or a combination of two or more of organic and inorganic high refractive index compounds and organic and inorganic low refractive index compounds that are light shielding compounds. In the photocurable light-shielding resin composition of the present invention, the high-refractive index compound and / or the low-refractive index compound that is a light-shielding compound is, for example, 0.1 to 50 parts by weight with respect to 100 parts by weight of the photocurable resin. The amount is preferably 0.1 to 30 parts by weight, more preferably 1 to 20 parts by weight, and particularly preferably 1 to 10 parts by weight.

  In the present invention, the difference in refractive index between the light-shielding compound and the refractive index of the cured product of the photocurable resin is preferably 0.1 or more, and particularly preferably 0.15 or more.

  The photocurable light-shielding resin composition in the present invention may further include other known additives, for example, an antioxidant, an ultraviolet absorber, a light stabilizer, a silane coupling agent, a thermal polymerization inhibitor, depending on the purpose. Leveling agents, surfactants, colorants, storage stabilizers, plasticizers, lubricants, solvents, fillers, anti-aging agents, wettability improvers, mold release agents, and the like can be added. In addition, the photo-curable light-shielding resin composition is used to reduce the light transmittance and reflectance of the resin, and organic and inorganic coloring pigments other than the light-shielding compound (for example, carbon black, rhodamine red, fastlogen blue, etc.) For example, 2 parts by weight or less, particularly 1 part by weight or less can be added to 100 parts by weight of the photocurable resin.

  The photocurable light-shielding resin composition in the present invention can be produced by mixing the above-described components by a conventional method. The order of adding each component is not particularly limited. When the light-shielding compound is liquid, it is preferable to disperse the compound in a photocurable resin with a fine particle size.

The light-shielding film in the present invention can be obtained by curing the photocurable light-shielding resin composition with light such as visible light or ultraviolet light, and can have a wide range of film thickness, for example, 0.5 μm or more. . The light irradiation can be performed by an irradiator capable of irradiating light of 200 to 450 nm, such as a metal halide lamp, a high-pressure water lamp, a xenon lamp, a halogen lamp, an LED irradiator, and an LD irradiator. The photocuring conditions may vary depending on the composition and film thickness of the light-shielding resin composition. For example, in the case of base resin; urethane acrylate, high refractive index compound; alumina, film thickness; ˜3000 mJ / cm ² .

  The light-shielding film in the present invention may have a film thickness in the range of 0.5 μm to 3 mm, for example, and in this film thickness, the light transmittance at 300 to 800 nm is 1% or less, for example 0.5% or less, preferably , 0.1% or less, particularly 0.05% or less, and further 0.01% or less. The light shielding film in the present invention is excellent in light shielding properties and various properties such as strength, durability and moisture resistance.

  The light shielding film in the present invention can be preferably in the form of a light shielding frame formed on a transparent front plate for a display panel. The front plate is a plate-like object such as a transparent sheet or film for protecting an opaque substrate such as a display panel from an external impact or the like. The front plate is not particularly limited as long as it is transparent. For example, a sheet made of a resin such as acrylic resin, polycarbonate resin, polyester resin, COP cycloolefin polymer (Zeonex, Arton, etc.) or COC cycloolefin copolymer (Appel, etc.) It can be a film, a glass plate, or a tempered glass plate. The front plate is preferably colorless. Although the thickness of a front plate will not be specifically limited if it has a protective effect, For example, it is 0.1-3 mm, Preferably it is 0.5-1.5 mm.

  The light-shielding frame in the present invention can be formed by applying a photocurable light-shielding resin composition on the front plate and curing it by light irradiation. The coating can be performed, for example, by screen printing or offset printing. The light irradiation can be performed by an irradiator capable of irradiating light of 200 to 450 nm, such as a metal halide lamp, a high-pressure water lamp, a xenon lamp, a halogen lamp, an LED irradiator, and an LD irradiator.

  The opaque substrate in the present invention is not limited as long as it is an opaque substrate that requires a light-shielding film on its surface, and examples thereof include a display panel, a CCD or CMOS photosensor element, and the like.

  Although it will not specifically limit if it is a display body as a display panel in this invention, For example, LCD, EL display, LED display, various electronic paper etc. are mentioned.

  The photocurable adhesive resin in the present invention is not limited as long as it is a resin that is cured by light and exhibits adhesiveness. For example, urethane (meth) acrylate, polybutadiene (meth) acrylate, polyisoprene (meth) acrylate, poly Examples include an isobutylene (meth) acrylate adhesive.

  In the present invention, the light-shielding film and the opaque substrate are bonded by a conventional method, for example, a light-curable adhesive resin on one or both of the light-shielding film (especially a transparent front plate having a light-shielding frame) and the opaque substrate (especially a display panel). Can be performed by applying light from above the light shielding film and curing the photocurable adhesive resin. Photocuring can be performed by irradiation with light such as visible light or ultraviolet light. Thermosetting is not necessary. The photocurable adhesive resin can be applied by, for example, a dispenser or screen printing. The light irradiation can be performed by an irradiator capable of irradiating light of 200 to 450 nm, such as a metal halide lamp, a high-pressure water lamp, a xenon lamp, a halogen lamp, an LED irradiator, and an LD irradiator.

  By adhering a light shielding film (especially a transparent front plate having a light shielding frame) and an opaque substrate (especially a display panel), a light shielding film (especially a transparent front plate having a light shielding frame) and an opaque substrate (especially a display panel) are formed. A complex can be obtained.

[Example 1] Formation of light-shielding frame and light transmittance of light-shielding frame (1) Photocurable light-shielding resin composition 1 is a urethane acrylate resin (U-4HA manufactured by Shin-Nakamura Chemical Co., Ltd.), 100 parts by weight, a photopolymerization initiator. (CIBA SPECIAL CHEMICALS I-184) 2 parts by weight, titanium dioxide (Ishihara Sangyo Co., Ltd.) 3 parts by weight and carbon black (Mitsubishi Chemical Co., Ltd.) 0.05 part by weight were prepared. The photocurable light-shielding resin composition 2 is composed of 100 parts by weight of urethane acrylate resin (Shin Nakamura Chemical U-4HA), 2 parts by weight of a photopolymerization initiator (CIBA SPECIAL CHEMICALS I-184), titanium dioxide (Ishihara Sangyo) 3 parts by weight, 20 parts by weight of alumina (manufactured by KINSEI MATEC (particle size: 1 μm)) and 0.05 parts by weight of carbon black (manufactured by Mitsubishi Chemical) were prepared. For comparison, the photocurable light-shielding resin composition 3 was composed of 100 parts by weight of urethane acrylate resin (U-4HA manufactured by Shin-Nakamura Chemical Co., Ltd.), 2 parts by weight of photopolymerization initiator (CI-BA SPECIAL CHEMICALS I-184), and carbon black. It was prepared by mixing 5 parts by weight (manufactured by Mitsubishi Chemical Corporation). The refractive index of D-line (587.56 nm) of the used material was as follows.
Urethane acrylate resin (U-4HA) + photopolymerization initiator (I-184): 1.51
Titanium dioxide (made by Ishihara Sangyo Co., Ltd.): 2.6
Alumina (KINSEI MATEC Co., Ltd. (particle size: 1 μm): 1.73

The photocurable light-shielding resin composition 1 or 2 is applied to a glass plate (25 × 25 × 1 mm) with a width of 5 mm, a length of 10 mm, and a thickness of 50 μm, and a metal halide lamp (wavelength: 350 nm; irradiation amount: 200 mW / cm ² ). The front plate 1 or 2 having a light shielding frame was prepared by irradiation for 30 seconds and curing. The comparative photocurable light-shielding resin composition 3 was applied to a glass plate in the same manner and irradiated with light, but hardly cured. Therefore, the comparative photocurable light-shielding resin composition 3 was used as a thermosetting catalyst (Japan). After adding 2 parts by weight of Perfure O) manufactured by Yushi Co., Ltd., the same was applied to a glass plate, irradiated with light, and then thermally cured at 120 ° C. for 1 hour to prepare a front plate 3 having a light shielding frame. Table 1 shows the composition of the photocurable light-shielding resin composition. Table 2 shows the transmittance of light having a wavelength of 400 nm in the light shielding frames of the front plates 1 to 3.

  The light shielding frames 1 and 2 in the present invention had a light transmittance of about 400 nm, which was the same as that of the light shielding frame 3 made of carbon black, and thus had a light shielding property comparable to this.

[Example 2]
A polybutadiene acrylate photocurable resin (manufactured by Kyoritsu Chemical Industry Co., Ltd .: World Lock No. 8963) is used as the photocurable adhesive resin 1, and a polybutadiene acrylate photocurable resin (Kyoritsu) is used as the photocurable adhesive resin 2. A product obtained by mixing 3 parts by weight of a thermosetting catalyst (Nippon Yushi Co., Ltd. Percure O) with 106 parts by weight was used.

A photocurable adhesive resin 1 or 2 is applied to a glass plate different from the glass plate used in Example 1, and a light-shielding frame is formed on any of the front plates 1 to 3 created in Example 1 thereon. The laminated surfaces were bonded together with a thickness of 100 μm. A metal halide lamp (wavelength: 350 nm; irradiation amount: 200 mW / cm ² ) was irradiated for 30 seconds from the upper part of what was obtained by pasting together to cure and bond the photocurable adhesive. The adhesion between the glass plate and the front plate is peeled off, and the reaction rate of the adhesive resin under the light-shielding frame of the front plate is reduced by FT-IR to decrease the peak of absorption of 1640 cm ⁻¹ of the carbon-carbon double bond of the acryl group. Calculation was made by comparison with the group absorption of 1700 cm ⁻¹ . The front plate 3 prepared in Example 1 was photocured and then cured after photocuring and further cured at 80 ° C. for 1 hour, and then the glass plate and the front plate were peeled off. The reaction rate of the adhesive resin under the shading frame of the face plate was also measured. Furthermore, for comparison, the acrylic resin plate with light shielding printing of a commercially available mobile phone was used as a front plate with a light shielding frame, and similarly, the reaction rate of the adhesive resin when thermally cured after photocuring was measured. Table 3 shows the measurement results of the reaction rate.

  When the front plate 1 or 2 having a light-shielding frame made from the photo-curable light-shielding resin composition 1 or 2 is cured and adhered by irradiating light from the top using the photo-curable adhesive resin 1 or 2, 90% adhesive resin reaction rate was obtained only by curing, and curing proceeded sufficiently. The front plate 3 having a light-shielding frame prepared from a comparative photo-curable light-shielding resin composition 3 containing carbon black or an acrylic plate with light-shielding printing of a commercially available mobile phone is lighted with the photo-curable adhesive composition 1 or 2. When cured and cured / adhered, only 20% of the reaction rate was obtained by photocuring and remained liquid, but when using the photocurable adhesive 2 containing a thermosetting catalyst, When heat curing was performed after curing, the reaction rate became 80% (however, quality deterioration and product life could be reduced by heating).

  According to the present invention, a light-shielding film having a sufficient light-shielding property (particularly a light-shielding frame having a sufficient light-shielding property on the front plate) and an opaque substrate (particularly a display panel) are combined with a light-shielding film (especially a light-shielding film frame on the front plate). ) Can be bonded only by light irradiation from the upper part, and the manufacturing operation of the composite of the light-shielding film (especially a light-shielding frame having sufficient light-shielding properties on the front plate) and the opaque substrate (particularly the display panel) is simplified. It does not degrade the quality of the composite or shorten the product life.

Claims (7)

  A method of obtaining a composite by bonding a light shielding film and an opaque substrate by photocuring through a photocurable adhesive resin, wherein the light shielding film has a refractive index of the photocurable resin and a cured product of the photocurable resin. A refractive index difference of 0.01 or more is formed from a photocurable light-shielding resin composition containing a compound that is incompatible and dispersible with the photocurable resin. Feature method.   2. The method according to claim 1, wherein the light shielding film is a light shielding frame on a transparent front plate, and the opaque substrate is a display panel.   The transparent front plate is a sheet or film made of acrylic resin, polycarbonate resin, polyester resin, COP cycloolefin polymer or COC cycloolefin copolymer, or a glass plate or a tempered glass plate, according to claim 1 or 2. Method.   The method according to claim 1, wherein the display panel is an LCD, an EL display, an LED display, or electronic paper.   The refractive index difference between the photocurable resin and the cured product of the photocurable resin is 0.01 or more, and is incompatible and dispersible with the photocurable resin. The light shielding film formed from the photocurable light shielding resin composition containing the compound which has.   A front panel for a display panel having the light shielding film according to claim 5 as a light shielding frame.   A display panel having the front plate according to claim 6.