JP5271474B2 - Display filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter for a display including an impact absorptive transparent tacky adhesive material layer which exhibits superior impact resistance and has appropriate tacky adhesive power, accompanied by repeelability with proper workability. <P>SOLUTION: The filter for the display includes the impact absorbing transparent tacky adhesive material layer, composed of tacky adhesive cured matter prepared by curing a composition containing a urethane-base (meth)acrylate compound (A-1) and a photopolymerization initiator (A-2), by the irradiation with UV rays and a protective function layer laminated on the impact absorptive transparent tacky adhesive material layer. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to a display filter.

  In recent years, flat panel displays have been rapidly developed. Among direct-view displays, non-light-emitting liquid crystal display devices (LCD) and self-light-emitting electroluminescence (EL) displays are digital still cameras, cell phones, Thinner and lighter weights are being mounted on PDAs, but the substrate has been made thinner to accommodate these small displays, and there are concerns about practical durability such as the liquid crystal panel being cracked by external impact. It was. In addition, when the display has been increased in size and used as a general home television, the display may be destroyed due to a child's accidental collision.

  The present inventors have previously proposed a configuration (Patent Document 1) in which an optical filter having an antireflection film is attached to the front surface of a display via an adhesive layer. However, development of miniaturization and weight reduction is progressing. When applied to a liquid crystal display, the thickness of the entire display is increased, which is undesirable because the thin feature is offset.

  On the other hand, self-luminous plasma display panels (PDPs) are also being commercialized, and development is progressing with regard to thinning and the accompanying impact resistance, large size, energy saving, and high contrast. A pasted optical filter having a visible light reflectance adjustment layer, a color tone adjustment layer, and an impact relaxation layer has been proposed (Patent Document 2) on a PDP display, but it was insufficient in terms of impact resistance.

  Further, as an optical filter for plasma display, a structure in which a protective panel is in close contact with a display through a transparent adhesive material having predetermined dynamic viscoelastic characteristics (Patent Document 3), and a specific storage elastic characteristic of the protective panel. A structure (Patent Document 4) in which the display is brought into close contact with a display via a transparent adhesive material having a thickness has been proposed, but when applied to a display, the interlayer film was crushed by impact and the glass substrate was also broken. On the other hand, in order to obtain a sufficient impact effect, the thickness of the entire filter must be increased, and the characteristics (thinness) of a thin display such as a liquid crystal display or an EL display cannot be utilized.

  Furthermore, when the optical filter is peeled off and used repeatedly, the adhesive strength is strong, and the optical filter is deformed at the time of peeling, so that it is necessary to realize an appropriate adhesive strength.

  That is, as a filter for liquid crystal displays, EL displays, and plasma displays, it has an appropriate adhesive force with satisfactory impact resistance and good removability while maintaining thinness and weight reduction. There was nothing.

JP 2002-260539 A Japanese Patent Laid-Open No. 2001-13877 JP 2003-29644 A JP 2003-29645 A

  The problem to be solved by the present invention is that, in view of the above-mentioned problems of the prior art, the thin display has an excellent impact resistance and has an appropriate adhesive force with good removability. It is an object of the present invention to provide a display filter having a shock absorbing transparent adhesive layer.

  As a result of intensive studies, the inventors of the present application have developed a cured product obtained by curing a composition containing a urethane-based (meth) acrylate compound and a photopolymerization initiator by ultraviolet irradiation, and exhibits excellent impact resistance performance. Discovered that it becomes a transparent adhesive material with suitable adhesive force with good removability with good workability, and exhibits excellent performance as a shock absorbing transparent adhesive layer of a display filter, and completed the present invention did.

  That is, the present invention provides an impact absorbing material comprising an adhesive cured product obtained by curing a composition containing a urethane-based (meth) acrylate compound (A-1) and a photopolymerization initiator (A-2) by ultraviolet irradiation. Provided is a display filter comprising a transparent adhesive layer and a protective functional layer laminated on the shock-absorbing transparent adhesive layer.

  According to the present invention, there is provided a novel display filter including an impact-absorbing transparent adhesive layer that exhibits an excellent impact resistance performance even when it is thin and has an appropriate adhesive force with good removability. It was. The display filter of the present invention exhibits excellent shock absorption even when it is thin, has an appropriate adhesive force, can be peeled off from the display surface without damaging the display, and peeled off from the display surface. However, the remaining adhesive material does not remain on the display surface. Therefore, the display filter of the present invention exhibits excellent performance as a display filter such as a PDP display, a liquid crystal display, and an EL display, for which development of thinning is in progress.

  As described above, the display filter of the present invention is a pressure-sensitive adhesive obtained by curing a composition containing a urethane (meth) acrylate compound (A-1) and a photopolymerization initiator (A-2) by ultraviolet irradiation. An impact-absorbing transparent adhesive layer made of a cured product is provided.

  Here, the “urethane (meth) acrylate compound (A-1)” has at least 1, preferably 2 to 4 urethane bonds in one molecule, and at least one in one molecule. Preferably, it means a compound having two (meth) acrylic acid residues. “(Meth) acrylic acid” means acrylic acid or methacrylic acid.

  Preferred examples of the urethane-based (meth) acrylate compound (A-1) used in the present invention include a dehydrogenation residue of at least one polyol selected from polyoxyalkylene polyol, aliphatic polyester polyol, and aliphatic polycarbonate polyol. And a urethane-based polyfunctional (meth) acrylate compound composed of a deisocyanate residue of an aliphatic isocyanate, and in particular, (1) produced by the following first method and represented by the following general formula [I] And (2) a compound produced by the following second method and represented by the following general formula [II].

That is, the first method is at least one polyol selected from polyoxyalkylene polyol, aliphatic polyester polyol, and aliphatic polycarbonate polyol, preferably a diol having two hydroxyl groups per molecule and an aliphatic polyisocyanate, preferably Is prepared by reacting an aliphatic diisocyanate having two isocyanate groups per molecule by a known urethanation reaction to synthesize an isocyanate group-terminated prepolymer and then reacting the terminal isocyanate group with the hydroxyl group of a hydroxyl group-containing acrylic compound. The urethane-type (meth) acrylate of the following general formula [I] is obtained by a two-stage urethanation reaction.
AH-I-O-I-AH [I]
(In the formula, AH is a dehydrogenation residue of a hydroxyl group of a hydroxyl group-containing acrylic compound. I is an aliphatic polyisocyanate residue. O is a dehydrogenation residue of a polyol.)

The second method comprises at least one polyol selected from polyoxyalkylene polyols, aliphatic polyester polyols and aliphatic polycarbonate polyols, preferably at least one polyol selected from diols having two hydroxyl groups per molecule. A hydroxyl group-containing acrylic compound obtained by polycondensation of a hydroxyl group at one end and a carboxyl group of carboxyl group-containing (meth) acrylic acid by a known esterification reaction, and an aliphatic polyisocyanate, preferably two per molecule. In this method, an aliphatic diisocyanate having an isocyanate group is reacted to obtain a urethane (meth) acrylate represented by the following general formula [II].
AC-O-I-O-AC [II]
(In the formula, AC is a dehydration acid residue of carboxyl group-containing (meth) acrylic acid, O is a dehydrogenation residue of polyol, and I is an aliphatic polyisocyanate residue.)

  The polyoxyalkylene glycol used in the present invention is polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, diol such as 1,4-butanediol, neopentyl glycol, 1,6-hexanediol or dioxane glycol and ethylene oxide. Or polyoxyalkylene glycols obtained by reaction with propylene oxide, and mixtures of two or more thereof. Polyoxyethylene glycol, polyoxypropylene glycol and polyoxytetramethylene glycol are preferable, and those having a molecular weight of 1,000 or more are particularly preferable from the viewpoint of impact absorption.

  The aliphatic polyester polyol used in the present invention includes a reaction product of a dihydric alcohol and a stoichiometrically short dicarboxylic acid or an anhydride or halide thereof. Suitable dihydric alcohols for the production of such polyesters are alkylene glycols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexane. Diols and dioxane glycols; oxyalkylene glycols such as reaction products of the above alkylene glycols or dihydric phenols with ethylene oxide or propylene oxide, diethylene glycol, triethylene glycol, higher polyoxyethylene glycol, dipropylene glycol, tripropylene glycol, higher poly Includes oxypropylene glycol and polyoxytetramethylene glycol (polytetrahydrofuran). Dicarboxylic acids and anhydrides suitable for the preparation of the above polyesters are fatty acids and anhydrides such as succinic acid, succinic anhydride, glutaric acid, glutaric anhydride, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic Acids, maleic anhydride and fumaric acid; cyclic fatty acids and anhydrides such as tetrahydrophthalic acid, hexahydrophthalic acid and their anhydrides.

  The aliphatic polycarbonate polyol used in the present invention is obtained by a reaction between a polyol and a carbonate compound such as dialkyl carbonate, alkylene carbonate, or diaryl carbonate. As the polyol used for the aliphatic polycarbonate, the dihydric alcohol exemplified above as a constituent component of the aliphatic polyester can be used. Examples of the dialkyl carbonate include dimethyl carbonate and diethyl carbonate, examples of the alkylene carbonate include ethylene carbonate, and examples of the diaryl carbonate include diphenyl carbonate.

  The aliphatic polyisocyanates used in the present invention include cycloaliphatic polyisocyanates, such as 1,2-propylene-diisocyanate, 1,3-propylene-diisocyanate, 1,2-butylene-diisocyanate, 1,4-butylene- Diisocyanates, pentamethylene-diisocyanates, hexamethylene-diisocyanates, 2,4,4-trimethylhexamethylene-diisocyanate, 2,2,4-trimethylhexamethylene-diisocyanate and dodecamethylene-diisocyanate; 1,3-cyclohexylene-diisocyanate and 1,4-cyclohexylene diisocyanate, methyl-2,4-cyclohexylene diisocyanate, methyl-2,6-cyclohexylene diisocyanate, 1,3-bis (isocyanate) Tomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate), and 4,4′-methylenebis (cyclohexyl isocyanate) Can do. Mixtures of two or more of the above diisocyanates can be used.

  Examples of the hydroxyl group-containing acrylic compound used in the first method for producing a urethane di (meth) acrylate in the present invention include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate. And the corresponding methacrylate. Particularly preferred compounds are 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate.

  The reaction between an isocyanate-terminated prepolymer and a hydroxyl group-containing acrylic compound to obtain a urethane-based (meth) acrylate, or the reaction between an aliphatic isocyanate compound and a hydroxyl group-containing alkylene acrylic compound is performed by a conventional method such as a polymerization inhibitor such as hydroquinone. It can be carried out by heating to 30 to 110 ° C. in the presence.

  The urethane-based (meth) acrylate compound (A-1) used in the present invention is commercially available, and these commercially available products can be preferably used in the present invention. As this commercial item, UN-9200A (manufactured by Negami Kogyo Co., Ltd.), NK oligo UA-334PZ, NK oligo UA-340P, NK oligo UA-160TM, NK oligo UA-170TX (manufactured by Shin-Nakamura Chemical Co., Ltd.) ) And the like.

  The photoinitiator (A-2) used in the present invention may be any known initiator for the photopolymerization of an acrylic substance, but is preferably a cleavage type initiator from the viewpoint of coloring the cured product. α-substituted acetophenone, thioxanthone and benzophenone as hydrogen abstraction type initiators, particularly preferred are intramolecular hydrogen abstraction type initiators, and commercially available oxy-phenyl-acetic acid 2- [2-oxo -2-Phenyl-acetoxy-ethoxy] -ethyl ester and oxy-phenyl-acetic acid 2- [2-hydroxy-ethoxy] -ethyl ester, IRUGACURE 754 (manufactured by Ciba Specialty Chemicals Co., Ltd.) It is done. The initiator may be a mixture of two or more. Further, when at least one of the above initiators is used as a main initiator, an initiator having absorption in a long wavelength region of 400 nm or longer, for example, a photopolymerization initiator such as bisacylphosphine oxide, monoacylphosphine oxide, The internal curability when the thickness is 0.3 mm or more can be improved. If the internal curability is insufficient, unreacted components may move to the surface of the adhesive material over time and become sticky. The addition amount of the initiator is a normal amount, generally 0.1 to 20% by weight, preferably 1 to 10% by weight of the content of the total urethane-based (meth) acrylate compound (A-1) of the adhesive. % Can be used. When using together the initiator which has absorption in the said 400 nm or more long wavelength area | region, it may be normally used in the range of 0.1 to 50 weight% of the initiator total amount.

  A reactive diluent may be added to the composition for forming the impact-absorbing transparent pressure-sensitive adhesive used in the present invention within a range that does not impair transparency for the purpose of adjusting viscosity and adjusting adhesiveness. As the diluent, a low molecular weight mono (meth) acrylate or di (meth) acrylate compound generally having a viscosity of 1,000 mPa · s / 25 ° C. or less can be used. Specific examples of the diluent include alkyl (meth) acrylates; for example, n-butyl (meth) acrylate, cyclohexyl (meth) acrylate, polyoxyalkylene mono (meth) acrylate, polyoxyalkylene di (meth) acrylate, and alkane. Diol di (meth) acrylate; for example, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 2,2′-butylethylpropanediol diacrylate, and the like. The addition amount of these reactive diluents is not particularly limited, but is usually about 1 to 100% by weight, preferably about 10 to 50% by weight, based on the content of the urethane (meth) acrylate compound (A-1).

  The thickness of the impact-absorbing transparent adhesive layer is preferably 0.3 mm or more. If the thickness is smaller than this, not only the impact resistance effect is low, but also air bubbles can easily enter when a protective functional layer is applied. , Handling during work becomes difficult, and shape retention after pasting becomes worse. The upper limit of the thickness is not particularly limited, but is preferably 3.0 mm or less from the viewpoint of taking advantage of the thin display. The thickness of the shock-absorbing transparent adhesive layer is preferably in the range of 0.3 to 1.0 mm from the viewpoint of display thickness and impact resistance when the protective functional layer and the shock-absorbing transparent adhesive layer are bonded together. preferable. The term “transparent” as used herein means that the image displayed on the display is transparent enough to be visually recognized when the filter of the present invention is attached.

  The impact-absorbing transparent adhesive material preferably has an adhesive performance for bonding to plastic or glass. The shock-absorbing transparent pressure-sensitive adhesive material itself may be sticky or may have a pressure-sensitive adhesive layer or adhesive formed on both sides or one side. The adhesive performance is not particularly limited as long as it can withstand the practical use of the product itself, but it is desirable to use a product that does not generate bubbles in the bonded portion when used in a high temperature state (35 to 100 ° C.). Further, by setting the 90 ° C. peel adhesive strength to 0.05 N / 25 mm width or more and 5 N / 25 mm width or less, preferably 0.1 N / 25 mm width or more and 3 N / 25 mm width or less, the plastic or glass to be deposited is used. Without being deformed, it can be easily used after being peeled off, and the adhesive material remaining on the display surface can be prevented. The test method is as follows.

  A. Shock-absorbing transparent adhesive layer, B. The filters laminated in the order of the protective functional layers were cut to a width of 25 mm, and the slide glass for microscope (76 mm (length) × 26 mm (width) × 1.0 mm (thickness)) Bond the shock-absorbing transparent adhesive surface. Next, using a tensile tester (for example, Autograph AGS500A (manufactured by Shimadzu Corporation)) in a 23 ° C. environment, the end of the filter is pulled 90 ° with respect to the glass at a speed of 50 mm / min. taking measurement. Further, the glass surface is observed after the test, and the presence or absence of the adhesive material remaining after peeling is confirmed by visual observation.

  As the protective functional layer used in the display filter of the present invention, a substrate used in a normal display filter can be used, and a glass flat plate, a plastic flat plate, a plastic film, and a plastic sheet are preferably used. In particular, those made of plastic are preferably used because they are not broken, light, easy to process, and easy to handle. The plastic here is not particularly limited, but acrylate, methacrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, phenyl (meth) acrylate, benzyl ( An acrylic resin composed of a homopolymer selected from (meth) acrylate, cyclo (meth) acrylate, cyclohexylmethylene (meth) acrylate, or a copolymer selected from two or more types, 4,4′-dihydroxyphenyl-2, 2-propane, 4,4′-dihydroxyphenyl-2,2-propane, 4,4′-dihydroxyphenyl-2,2-butane, 4,4′-dihydroxyphenyl-2,2-pentane, 4,4 ′ -Dihydroxyphenyl-1,1-cyclopentane Carbonate polymer obtained by phosgene method or transesterification method, dimethylene carbonate, trimethylene carbonate, tetramethylene carbonate, pentamethylene carbonate, hexamethylene carbonate, diethylene carbonate, triethylene carbonate, tetraethylene carbonate, pentaethylene carbonate, hexa Polycarbonate resin consisting of carbonate polymer obtained from dihydric alcohol such as ethylene carbonate and dialkyl carbonate, polyethylene, polypropylene, butadiene, isoprene, polystyrene, polyacrylate, polymethacrylate, poly-1-butene, poly-1-pentene , Polymethylpentene homopolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic Polyolefin resin composed of ester copolymer, polyether resin, polystyrene resin, polyester resin, polysulfone resin, polyamide resin, polysulfide resin, unsaturated polyester resin, epoxy resin, melamine resin, phenol resin, diallyl phthalate resin, polyimide resin, Menimide resin, polyphosphazene resin, polyvinyl resin, polyethylene terephthalate resin and the like can be mentioned. Of these, acrylic resin, polycarbonate resin, polyolefin resin, and polyethylene terephthalate resin are preferably used in terms of translucency and workability. In addition, as the protective functional layer, a resin selected from a triacetyl cellulose resin, a polyolefin resin, a polyvinyl alcohol resin, or the like, or a laminate of two or more kinds of resins may be used.

  The thickness of the protective functional layer in the display filter of the present invention is not particularly limited, but a thickness of 0.5 mm or less is preferable from the viewpoint of reduction in thickness and weight. On the other hand, in order to exert a display protection function, the thickness is preferably 0.05 mm or more. As the protective functional layer, a multilayered plastic film is also preferably used in order to improve breaking performance and impact resistance.

  The breaking energy of the display filter of the present invention by an impact test is preferably 0.5 J or more, more preferably 1.0 J or more. The test method is as follows.

  Place a sample for impact resistance test on a rubber rubber (Float glass (thickness 0.7mm, 30mm x 40mm) with a display filter bonded with a rubber roll through an adhesive sheet), and freely place a steel ball on the top surface of the protective functional layer Let it drop and visually check the state of breakage of the float glass. A steel ball having a mass of 66.7 g is dropped from a height of 70 cm from the surface of the laminate for impact test, and B is the one with no change in the float glass. 5 J, where cracks and cracks were observed was defined as C. Furthermore, the same steel ball is dropped from a height of 150 cm, and A is the one with no change in the float glass, and the fracture energy can be calculated as 1.0 J from the relationship between the height and the weight of the steel ball.

  On one or both sides of the protective functional layer of the display filter of the present invention, a hard coat film for preventing scratches or a hard coat film for preventing scratches and ensuring adhesion with an antireflection film may be provided. preferable. Particularly when the protective functional layer is made of plastic, it is preferably provided. As the material used for forming the hard coat film, a thermosetting organopolysiloxane hard coating agent or an ultraviolet curable acrylic hard coating agent is preferable. More preferably, a hard coat film having a refractive index equivalent to the refractive index of the base material is preferable because it becomes an optical filter in which light interference fringes are hardly visible. Also, a hard coat film containing inorganic fine particles is preferably used in order to improve the resistance to scratches on the surface. These hard coat films are well known in this field, and plastic plates having a hard coat film formed on the surface are commercially available (for example, “Lumirror” manufactured by Toray Industries, Inc. and trade name “Acrylite MR200 manufactured by Mitsubishi Rayon). Therefore, these commercially available plastic plates can be preferably used as the protective functional layer.

  Further, by forming an antireflection film on the protective functional layer or hard coat film of the display filter of the present invention, a more excellent contrast can be obtained. By forming the antireflection film, the reflectance of the surface of the display filter in visible light can be suppressed, and the visibility of the display can be improved. As the antireflection film, a laminated film of two or more layers composed of a low refractive index layer and a high refractive index layer is preferably used, but non-glare treatment that suppresses glare by irregularly reflecting the surface may be used. It is preferable to select either or both of these depending on the display environment and display performance, but the former is preferably used when higher contrast is required. For the formation of the antireflection film, the antireflection film may be formed directly on the surface of the display filter of the present invention by a known method such as vacuum deposition, sputtering, ion plating, or wet coating. A film provided with a prevention film may be attached.

Examples of the material constituting the antireflection film include SiO ₂ , MgF ₂ , AlF ₃ , BaF ₂ , LiF, Na ₃ AlF ₆ , Na ₅ Al ₃ F ₁₄ , NaF, SrF ₂ , ZrO ₂ , TiO ₂ , SiO , TiN, Y ₂ O ₃ , Yb ₂ O ₃ , Sb ₂ O ₃ , Sb ₂ O ₅ , SnO ₂ , In ₂ O ₃ , ITO, Ta ₂ O ₅ , CeO ₂ , MgO, HfO ₂ , Pr ₂ O _{3 , Pr 6 O 11, Bi 2} O 3, Cr 2 O 3, Eu 2 O 3, Fe 2 O 3, La 2 O 3, MoO 3, Nd 2 O 3, PbO, Sm 2 O 3, Sc 2 O 3 ZnO, CaF ₂ , SmF ₃ , ZnS, Ge, Si and the like. Among them, SiO ₂ and MgF ₂ are preferably used as the low refractive index layer in terms of transparency, film hardness, and film adhesion, and ZrO ₂ , TiO ₂ , Ta ₂ O ₅ , ZnO, ITO are used as the high refractive index layer. SnO ₂ , Y ₂ O ₃ , MgO and CeO ₂ are preferably used. The antireflection film can be provided directly on the protective functional layer, but it can also be formed by laminating a film provided with an antireflection film. The reflectance of the antireflection film formed on these protective functional layers is preferably 1.5% or less because higher contrast can be obtained.

  The antireflection film can also be formed by a wet coating method in which a paint is coated. For example, if a low refractive index layer mainly composed of an organosilicon compound and silica fine particles and a layer having a refractive index higher by 0.03 or more than the low refractive index layer are formed thereunder, an antireflection film Is obtained. Various coating methods can be selected depending on the purpose. For example, known methods such as a dip coating method, a spin coating method, a slit die coating method, a gravure coating method, a reverse coater method, a spray method, and a roll coating method can be used. In the case of a substrate having a thickness of 0.5 mm or more, a dip coating method or a slit die coating method is preferably used.

  Furthermore, it is possible to preferably form a water repellent layer on the outermost layer of the antireflection film in order to prevent contamination. Examples of the method for forming the water repellent layer include a wet coating method and a vacuum deposition method. When the antireflection film is formed by vacuum deposition, it is preferably formed by a vacuum deposition method from the viewpoint of production efficiency. For water repellency, the static contact angle with respect to water is preferably 60 degrees or more, and when it is less than 60 degrees, dirt is easily attached, and it is difficult to wipe off when wiping with a cloth or the like. For example, as a material for forming the water repellent layer, a polysiloxane compound having a silanol group at the end, a silazane compound, a compound having a perfluoroalkyl group and a reactive functional group can be preferably used.

In the display filter of the present invention, it is preferable that either or both of the protective functional layer and the impact-absorbing transparent adhesive material contain an ultraviolet absorbing compound or a dye for preventing deterioration of the liquid crystal display or EL display. In particular, various dyes and UV absorbers are preferably used to improve the weather resistance (light) of the display. Examples of UV absorbers include hindered phenols, benzotriazoles, benzophenones, benzoates, and cyanoacrylates. Is used. It is also preferable to add inorganic fine particles as a refractive index adjusting agent. For example, SiO ₂ , MgF ₂ , ZrO ₂ , TiO ₂ , SiO, TiN, Yb ₂ O ₃ , Sb ₂ O ₃ , Sb ₂ O ₅ , _{SnO 2, In 2 O 3,} ITO, Ta 2 O 5, CeO 2, MgO, Cr 2 O 3, Fe 2 O 3, MoO 3, PbO, ZnO, CaF 2 and the like. Among them, SiO ₂ and MgF ₂ are preferably used as the low refractive index agent, and ZrO ₂ , TiO ₂ , Ta ₂ O ₅ , ZnO, ITO, SnO ₂ , MgO, CeO _{2 and the} like are used as the high refractive index agent. Preferably used. As the dye, cyanine dye, merocyanine dye, (thio) pyrylium dye, naphtholactam dye, pentacene dye, oxyindolizine dye, quinoid dye, aminium dye, diimmonium dye, indoaniline dye, nickel thio complex dye, etc. are preferably used. It is done. The addition amount of these additives is not particularly limited and can be set as appropriate. Usually, the addition amount of each additive is 10% by weight with respect to the weight of the protective functional layer or the impact-absorbing transparent adhesive layer. % Or less.

  Depending on the display, it is necessary to shield near-infrared rays, so it is also preferable to add a near-infrared-absorbing compound to either or both of the protective functional layer and the impact-absorbing transparent adhesive material. Anthraquinone compounds, phthalocyanine compounds , Naphthalocyanine compounds, metal oxide fine powders, imonium compounds, diimonium compounds, aminium salt compounds, thiourea compounds, bisthiourea compounds, square acid compounds, metal complex compounds, and the like. The addition amount of the near-infrared absorbing compound is not particularly limited and can be appropriately set. Usually, the addition amount of the additive is 10% by weight with respect to the weight of the protective functional layer or the impact-absorbing transparent adhesive layer. It is as follows.

  The display to which the display filter of the present invention can be applied is not particularly limited, but preferred examples include self-luminous electroluminescence (EL), light-emitting diode (LED), which are direct-view flat panel displays, Known displays such as a PDP, a field emission display (FED), a fluorescent display tube (VFD), a non-light emitting LCD, and an electrochromic display (ECD) can be given. There is a high demand for weight reduction and thinning of these display panels, and the glass base material used for the base material of the display is also thinned. Because of its versatility such as mobile phones, digital still cameras, PDAs, and consumer displays, Since high product safety is required and high impact resistance is required, the display filter of the present invention can be used effectively. In particular, it can be used for a plasma display, an electroluminescence display, or a liquid crystal display in which the thickness of the substrate of the display is 3.0 mm or less, and more preferably used for a mobile phone, a digital still camera, or a PDA. The display substrate can be suitably used for an electroluminescence display or a liquid crystal display having a thickness of 1.0 mm or less.

Example 1
(1) Manufacturing method of transparent impact-absorbing pressure-sensitive adhesive material As urethane-based di (meth) acrylate compound (A-1), NK Oligo UA-334PZ (manufactured by Shin-Nakamura Chemical Co., Ltd., manufactured by Method 1 above) and used as the diol component Using polyoxypropylene glycol, 90 parts by weight of a molecular weight of about 10000), as a diluent, polyethylene glycol diacrylate (9 oxyethylene repeating units, molecular weight 508, trade name “NK Ester A-400” (Shin Nakamura Chemical Co., Ltd.) 10) parts by weight of oxy-phenyl-acetic acid 2- [2-oxo-2-phenyl-acetoxy-ethoxy] -ethyl ester and oxy-phenyl-acetic acid 2- Mixture of [2-hydroxy-ethoxy] -ethyl ester (trade name IRUGACUR 754 was applied to a polyester separator thickness 100μm (the Ciba Specialty Chemicals Co., Ltd.)) a UV-curable composition obtained by mixing 1 part by weight, under a nitrogen atmosphere, at an ultraviolet lamp 1,000 mJ / cm ² Ultraviolet light was irradiated and photopolymerized to produce a transparent shock absorbing adhesive material having a thickness of 0.5 mm.

(2) A polyethylene terephthalate resin plate (trade name “Lumirror” manufactured by Toray Industries, Inc., thickness 0.1 mm) having a hard coat film on both sides was cut into 30 mm × 40 mm to form a protective functional layer.

(3) Next, the transparent impact-absorbing pressure-sensitive adhesive material (thickness 0.5 mm, 30 mm × 40 mm) obtained in (1) above is applied to the hard coat film surface of the protective functional layer obtained in (2) above using a rubber roll. An affixed display filter was obtained.

(4) A display filter was bonded to a glass substrate (float glass, thickness 0.7 mm, 30 mm × 40 mm) with a rubber roll through an adhesive sheet to obtain a sample for an impact resistance test.

Example 2
(1) An acrylic resin plate (trade name “Acrylite MR200” manufactured by Mitsubishi Rayon, thickness 1.0 mm) having a hard coat film on both sides was cut into 30 mm × 40 mm to form a protective functional layer.

(2) Next, a display filter was obtained in which the transparent impact-absorbing adhesive material used in Example 1 was attached to the hard coat film surface of the protective functional layer obtained in (1) above using a rubber roll.

(3) A filter for display was attached to a glass substrate (float glass, thickness 0.7 mm, 30 mm × 40 mm) with a rubber roll through an adhesive sheet to obtain a sample for an impact resistance test.

Example 3
(1) Manufacturing method of transparent impact-absorbing pressure-sensitive adhesive material As urethane-based di (meth) acrylate compound (A-1), NK Oligo UA-340P (manufactured by Shin-Nakamura Chemical Co., Ltd., manufactured by the above-mentioned method 1 and used as a diol component) 95 parts by weight of polyoxypropylene glycol, molecular weight of about 13000), 5 parts by weight of 2-hydroxyethyl methacrylate as a diluent, and photopolymerization initiator as trade name IRUGACURE 754 (Ciba Specialty Chemicals) The ultraviolet curable composition mixed with 1 part by weight of the product manufactured by Co., Ltd. was applied to a polyester separator having a thickness of 100 μm, and irradiated with 1,000 mj / cm ² of ultraviolet light with a UV lamp in a nitrogen atmosphere. Polymerization was performed to prepare a transparent impact-absorbing adhesive material having a thickness of 0.5 mm.

(2) A polyethylene terephthalate resin plate (trade name “Lumirror” manufactured by Toray Industries, Inc., thickness 0.1 mm) having a hard coat film on both sides was cut into 30 mm × 40 mm to form a protective functional layer.

(3) Next, the transparent impact-absorbing pressure-sensitive adhesive material (thickness 0.5 mm, 30 mm × 40 mm) obtained in (1) above is applied to the hard coat film surface of the protective functional layer obtained in (2) above using a rubber roll. An affixed display filter was obtained.

(4) A display filter was bonded to a glass substrate (float glass, thickness 0.7 mm, 30 mm × 40 mm) with a rubber roll through an adhesive sheet to obtain a sample for an impact resistance test.

Example 4
(1) An acrylic resin plate (trade name “Acrylite MR200” manufactured by Mitsubishi Rayon, thickness 1.0 mm) having a hard coat film on both sides was cut into 30 mm × 40 mm to form a protective functional layer.

(2) Next, a display filter was obtained in which the transparent impact-absorbing adhesive material used in Example 3 was attached to the hard coat film surface of the protective functional layer obtained in (1) above using a rubber roll.

(3) A filter for display was attached to a glass substrate (float glass, thickness 0.7 mm, 30 mm × 40 mm) with a rubber roll through an adhesive sheet to obtain a sample for an impact resistance test.

Comparative Example 1
(1) Production method of transparent impact-absorbing pressure-sensitive adhesive material 100 parts of 2-ethylhexyl acrylate and 0.2 part of IRUGACURE 754 (manufactured by Ciba Specialty Chemicals Co., Ltd.) are mixed and a viscous liquid of a partial polymer is obtained by ultraviolet irradiation. It was. An ultraviolet curable composition obtained by mixing 0.2 part of trimethylolpropane triacrylate (internal crosslinking agent) and 0.2 part of IRUGACURE754 (manufactured by Ciba Specialty Chemicals Co., Ltd.) with this viscous liquid is a polyester system having a thickness of 100 μm. It was applied to a separator, and irradiated with 2,000 mj / cm ² of ultraviolet rays with a UV lamp in a nitrogen atmosphere to cause photopolymerization, thereby preparing a transparent impact-absorbing adhesive material having a thickness of 0.5 mm.

(2) A polyethylene terephthalate resin plate (trade name “Lumirror”, thickness 0.1 mm, manufactured by Toray Industries, Inc.) having hard coat films on both sides was cut to 30 mm × 40 mm to form a protective functional layer.

(3) Next, the transparent impact-absorbing pressure-sensitive adhesive material (thickness 0.5 mm, 30 mm × 40 mm) obtained in (1) above is applied to the hard coat film surface of the protective functional layer obtained in (2) above using a rubber roll. An affixed display filter was obtained.

Comparative Example 2
(1) In the same manner as in Example 1, a hard coat film was provided on both sides of a 1.5 mm thick acrylic resin plate (trade name Acrylite MR200, manufactured by Mitsubishi Rayon Co., Ltd., thickness 1.5 mm), and a protective functional layer was formed. Obtained.

(2) Next, one side of the protective functional layer obtained in (1) above as a double-sided adhesive tape (Industrial 3M Co., Ltd. industrial tape, Y-4905, acrylic foam type, thickness 0.5 mm, 30 mm × 40 mm) A display filter affixed using a rubber roll was obtained.

(3) A filter for display was bonded to a glass substrate similar to that of Example 1 with a rubber roll via a double-sided adhesive tape to obtain a sample for an impact resistance test.

Comparative Example 3
(1) The acrylic resin plate used in Example 1 was used as a protective functional layer.

(2) Next, using a double-sided pressure-sensitive adhesive tape (Industrial 3M Co., Ltd. industrial tape, Y-4905, acrylic foam type, thickness 0.5 mm), a 5 mm wide square frame having an outer periphery of 30 mm × 40 mm. Created. Using a rubber roll on one side of the protective functional layer obtained in (1) above, a display filter with a frame attached was obtained.

(3) A filter for display was bonded to a glass substrate similar to that of Example 1 with a rubber roll via a double-sided adhesive tape to obtain a sample for an impact resistance test.

  The impact test was performed by the above-described method for the samples for impact resistance test obtained in Examples 1 to 3 and Comparative Examples 1 to 3. Moreover, about the display filter produced in each example, 90 degree peeling adhesive force was measured by the said method, and the adhesive material remainder on the glass substrate after peeling was observed visually.

  The results are shown in Table 1 below. As shown in Table 1 below, the display filters of Examples 1 to 4 have good impact resistance, have moderate adhesive strength, and the remaining adhesive material did not remain on the glass surface after peeling. . On the other hand, the display filters of Comparative Examples 1 to 3 had too high adhesive strength, and the remaining adhesive material remained on the glass surface after peeling. Further, the display filters of Comparative Examples 2 and 3 also had insufficient impact resistance.

Claims (9)

Urethane (meth) acrylate compound (A-1) obtained by using polyoxyalkylene glycol having a molecular weight of 1000 or more as a raw material, and a low molecular weight mono (meth) acrylate having a viscosity of 1,000 mPa · s (25 ° C.) or less. Or a reactive diluent that is a di (meth) acrylate compound and an intramolecular hydrogen abstraction type photopolymerization initiator (A-2), and the urethane-based (meth) acrylate compound (A-1) An impact-absorbing transparent adhesive layer comprising an adhesive cured product obtained by curing the composition containing 5 to 10% by weight of the reactive diluent with respect to the total content of the reactive diluent by ultraviolet irradiation; A display filter comprising a protective functional layer laminated on a shock-absorbing transparent adhesive layer.   The photopolymerization initiator (A-2) contains oxy-phenyl-acetic acid 2- [2-oxo-2-phenyl-acetoxy-ethoxy] -ethyl ester and oxy-phenyl-acetic acid 2- [2- 2. A display filter according to claim 1, which is a mixture of hydroxy-ethoxy] -ethyl ester.   The display filter according to claim 1 or 2, wherein the impact-absorbing transparent viscous material layer has a thickness of 0.3 mm or more and 3.0 mm or less, and a fracture energy by an impact test of 0.5 J or more.   Either or both of the impact-absorbing transparent adhesive layer and the protective functional layer include at least one material selected from the group consisting of an ultraviolet absorbing compound, a near infrared absorbing compound, a dye, and a refractive index modifier. 4. The display filter according to any one of 1 to 3.   The display filter according to any one of claims 1 to 4, wherein the protective functional layer includes a plate-like plastic as a constituent component, and a hard coat film is provided on one side or both sides thereof.   The display filter according to any one of claims 1 to 5, wherein an antireflection film is provided on an upper surface of the protective functional layer or the hard coat film.   The display filter according to any one of claims 1 to 6, which is used for a plasma display, a liquid crystal display or an EL display. A shock-absorbing transparent adhesive layer for bonding the display surface and the protective functional layer of the display filter,
Urethane (meth) acrylate compound (A-1) obtained by using polyoxyalkylene glycol having a molecular weight of 1000 or more as a raw material, and a low molecular weight mono (meth) acrylate having a viscosity of 1,000 mPa · s (25 ° C.) or less. Or a reactive diluent that is a di (meth) acrylate compound and an intramolecular hydrogen abstraction type photopolymerization initiator (A-2), and the urethane-based (meth) acrylate compound (A-1) A shock-absorbing transparent adhesive for a display filter, comprising an adhesive cured product obtained by curing the composition containing 5 to 10% by weight of the reactive diluent with respect to the total content of the reactive diluent by ultraviolet irradiation. Material layer. A composition that is used as an impact-absorbing transparent adhesive layer for bonding a display surface and a protective functional layer of a display filter, and becomes an adhesive cured product by ultraviolet irradiation,
Urethane (meth) acrylate compound (A-1) obtained by using polyoxyalkylene glycol having a molecular weight of 1000 or more as a raw material, and a low molecular weight mono (meth) acrylate having a viscosity of 1,000 mPa · s (25 ° C.) or less. Or a reactive diluent that is a di (meth) acrylate compound and an intramolecular hydrogen abstraction type photopolymerization initiator (A-2), and the urethane-based (meth) acrylate compound (A-1) The ultraviolet curable composition for impact-absorbing transparent adhesive layers in which the reactive diluent is contained in an amount of 5 to 10% by weight based on the total content of the reactive diluent .