JP2006091699A - Protective member, protective member laminate using the same, and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protective member having a light weight and good impact resistance.
A resin material obtained by polymerizing 15 to 89.9 parts by weight of an acrylic acid derivative using 0.1 to 5 parts by weight of a polymerization initiator in the presence of 10 to 80 parts by weight of an acrylic acid derivative polymer. A protective member comprising The acrylic acid derivative polymer preferably has a weight average molecular weight of 100,000 or more, and the polymerization initiator is a photopolymerization initiator or a thermal polymerization initiator. The glass transition temperature of the protective member is preferably 0 ° C. or lower, the protective member itself has adhesiveness, and the visible light transmittance is preferably 80% or higher.
[Selection figure] None

Description

  The present invention relates to a protective member capable of preventing cracking of a transparent base material such as glass and plastic, and preventing scattering when the glass is broken, and in particular, CRT (cathode ray tube), PDP (plasma display). Panel), liquid crystal panel, EL (electroluminescence) display glass or plastic on the front side of the display or glass or plastic on the front plate for these displays is prevented from being broken or damaged, and such glass or plastic is broken. The present invention relates to a protective member that can prevent scattering of the protective member, a protective member laminate using the protective member, and a display device.

Glass cathode ray tubes (CRTs) are determined to be anti-scattering and not penetrated by an impact resistance test by dropping a steel ball in accordance with UL standards or radio wave control methods for televisions and displays. Therefore, in order to satisfy this standard, it is necessary to design the CRT glass to be thick, and the weight of the CRT is increased. Then, the method of laminating | stacking the synthetic resin protective film which has a self-restoration property on glass as a means to give scattering prevention property without making glass thick is proposed (refer patent document 1 and patent document 2). However, although this proposal is characterized by anti-scattering properties, it does not have a function of preventing glass from breaking.
On the other hand, in a plasma display (PDP) which is one of flat panel displays (FPD), a space of about 1 to 5 mm is provided from the PDP panel in order to prevent cracking of the PDP panel, and the front of glass or the like having a thickness of about 3 mm. A face plate is provided on the front surface (viewing surface side). For this reason, as the PDP is increased in size, the area of the front plate is also increased, which increases the weight of the PDP.

Japanese Patent Laid-Open No. 06-333515 Japanese Patent Laid-Open No. 06-333517

  In view of the above, the present invention provides a protective member that is lightweight and effective in preventing cracking of the front surface of a display or a display front plate or preventing scattering in the case of cracking, and a protective member laminate and a display device using the protective member. For the purpose.

The present invention relates to the following.
1. A resin material obtained by polymerizing 15 to 89.9 parts by weight of an acrylic acid derivative with 0.1 to 5 parts by weight of a polymerization initiator in the presence of 10 to 80 parts by weight of an acrylic acid derivative polymer. A protective member.
2. Item 2. The protective member according to Item 1, wherein the acrylic acid derivative polymer has a weight average molecular weight of 100,000 or more.
3. Item 3. The protective member according to any one of Items 1 and 2, wherein the polymerization initiator is a photopolymerization initiator.
4). Item 4. The protective member according to any one of Items 1 to 3, wherein the glass transition temperature is 0 ° C or lower.
5. Item 5. The protective member according to any one of Items 1 to 4, which has adhesiveness.
6). Item 6. The protective member according to any one of Items 1 to 5, wherein the visible light transmittance is 80% or more.
7). Item 8. A protective member laminate comprising the protective member according to any one of Items 1 to 7 and an antireflection layer or an electromagnetic wave shielding layer.
8). The display apparatus formed by bonding the protection member laminated body of claim | item 7 to the surface.
9. Item 9. The display device according to Item 8, wherein the display to which the protective member laminate is bonded is a plasma display panel.

  The protective member of the present invention does not tear even when subjected to a strong impact, and therefore effectively works to prevent cracking of the front surface of the display or the display front plate or to prevent scattering. In addition, the protective member in the present invention serves to prevent scratches on the front surface of the display or the display front plate, and also functions as an impact absorbing material because of its absorbability against impact. The protective material laminate having this protective member has the functions of the laminated layers in addition to the above-described effects, for example, electromagnetic wave shielding properties, antireflection properties, etc., and the protective member or protective member laminate is bonded. The displayed display device or its front plate is not easily broken even when subjected to an impact and is safe. In addition, even when broken, scattering of the fragments is prevented or reduced.

  The acrylic acid derivative polymer in the present invention is obtained by polymerizing an acrylic acid derivative, and its weight average molecular weight (measured using a standard polystyrene calibration curve by gel permeation chromatography) is 100,000. The above is preferable. The acrylic acid derivative polymer may be a polymer obtained by polymerization using a monomer other than the acrylic acid derivative.

  Examples of the acrylic acid derivatives include acrylic acid or methacrylic acid, and derivatives thereof. Specifically, monomers having one polymerizable unsaturated bond in the molecule include methyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, 2-ethylhexyl methacrylate, isononyl methacrylate, n-octyl methacrylate, and lauryl methacrylate. , Alkyl methacrylates such as stearyl methacrylate, methyl acrylate, n-butyl acrylate, i-butyl acrylate, 2-ethylhexyl acrylate, isononyl acrylate, alkyl acrylates such as n-octyl acrylate, aralkyl methacrylates such as benzyl methacrylate, benzyl acrylate, etc. Alkoxyalkyl methacrylates such as aralkyl acrylate and butoxyethyl methacrylate, butoxyethyl acrylate Alkoxyalkyl acrylates such as N, N-dimethylaminoethyl methacrylate, aminoalkyl methacrylates such as N, N-dimethylaminoethyl acrylate, aminoalkyl acrylates such as N, N-dimethylaminoethyl acrylate, methacrylate esters of (diethylene glycol ethyl ether), (triethylene glycol butyl ether) ) Methacrylic acid ester, (dipropylene glycol methyl ether) methacrylic acid ester, etc. (polyalkylene glycol alkyl ether) methacrylic acid ester, (diethylene glycol ethyl ether) acrylic acid ester, (triethylene glycol butyl ether) acrylic acid Esters (polyalkylene glycol alkyls such as acrylic acid esters of (dipropylene glycol methyl ether)) (Polyalkylene glycol aryl) such as (polyether glycol aryl ether), methacrylic acid ester of (polyalkylene glycol aryl ether) such as methacrylic acid ester of (hexaethylene glycol pheny ether), acrylic acid ester of (hexaethylene glycol pheny ether) Ether) acrylic acid esters, cyclohexyl methacrylate, cyclohexyl acrylate, dicyclopentanyl methacrylate, dicyclopentanyl acrylate, isobornyl methacrylate, methoxylated cyclodecatriene methacrylate, isobornyl acrylate, methoxylated cyclodecatriene acrylate, etc. Methacrylic acid ester or acrylic acid ester having an alicyclic group, heptadecafluorodecyl methacrylate Fluorinated alkyl methacrylates such as heptadecafluorodecyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, 4 -Methacrylic acid ester or acrylic acid ester having a hydroxyl group such as hydroxybutyl acrylate, glycerol methacrylate or glycerol acrylate, methacrylic acid ester or acrylic acid ester having a carboxyl group such as acrylic acid or methacrylic acid, glycidyl such as glycidyl methacrylate or glycidyl acrylate Methacrylic acid ester or acrylic acid ester having a group, acrylamide, etc. That. These can be used alone or in combination of two or more.

  These monomers having one polymerizable unsaturated bond in the molecule can be used alone or in combination of two or more.

  A monomer having two or more polymerizable unsaturated bonds in the molecule can be used together with the monomer having one polymerizable unsaturated bond in the molecule. Such monomers include bisphenol A dimethacrylate 1,4-butanediol dimethacrylate, 1,3-butylene glycol dimethacrylate, diethylene glycol dimethacrylate, glycerol dimethacrylate, neopentyl glycol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol. Dimethacrylate, tetraethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, tris (methacryloxyethyl) isocyanurate, pentaerythritol tetramethacrylate, dipentaerythritol tetramethacrylate, dipentaerythritol hexamethacrylate, dipentaerythritol pen Tame Acrylate, bisphenol A diacrylate, 1,4-butanediol diacrylate, 1,3-butylene glycol diacrylate, diethylene glycol diacrylate, glycerol diacrylate, neopentyl glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, Tetraethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, tris (acryloxyethyl) isocyanurate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, etc. Can be mentioned.

（ただし、式中、Ｒはエチレン基又はプロピレン基を示し、ｍ及びｎはそれぞれ独立に、１〜２０の整数を示す）で示されるビスフェノールＡのアルキレンオキシド付加物のジアクリレート、一般式（ｂ）

（ただし、式中、ｍ及びｎはそれぞれ独立に、１〜１０の整数を示す）で示されるビスフェノールＡのエピクロルヒドリン変性物とアクリル酸の付加エステル化物、ビスフェノールＡジメタクリレート、１，４−ブタンジオールジアクリレート、１，３−ブチレングリコールジアクリレート、ジエチレングリコールジメタクリレート、グリセロールジメタクリレート、ネオペンチルグリコールジアクリレート、一般式（ｃ）

（ただし、式中、Ｒはエチレン基又はプロピレン基を示し、ｍ及びｎはそれぞれ独立に、１〜２０の整数を示す）で示されるリン酸のアルキレンオキシド付加物のジアクリレート、一般式（ｄ）

（ただし、式中、ｍ及びｎはそれぞれ独立に、１〜１０の整数を示す）で示されるフタル酸のエピクロリン変性物とアクリル酸の付加エステル化物、ポリエチレングリコールのジアクリレート、ポリプロピレングリコールのジメタクリレート、テトラエチレングリコールジアクリレート、一般式（ｅ）

（ただし、式中、ｍ及びｎはそれぞれ独立に、１〜２０の整数を示す）で示される１，６−ヘキサンジオールのエピクロリン変性物とアクリル酸の付加エステル化物（アクイリル基を一分子中に２個有するもの）、トリメチロールプロパントリアクリレート、ペンタエリスリトールトリアクリレート、一般式（ｆ）

（ただし、式中、Ｒはエチレン基又はプロピレン基を示し、３個のｍはそれぞれ独立に、１〜２０の整数を示す）で示されるリン酸のアルキンオキシド付加物のトリアクリレート、一般式（ｇ）

（ただし、式中、Ｒはエチレン基又はプロピレン基を示し、ｍ、ｍ′及びｍ″はそれぞれ独立に、１〜２０の整数を示す）で示されるトリメチロールプロパンのアルキレンオキシド付加物のトリアクリレート、トリス（メタクリロキシエチル）イソシアヌレート、ペンタエリスリトールテトラアクリレート、ジペンタエリスリトールテトラアクリレート、ジペンタエリスリトールヘキサアクリレート、ジペンタエリスリトールペンタアクリレートなどが挙げられる。これらのモノマーは、単独で又は２種以上を組み合わせて用いることができる。 Examples of the monomer having two or more polymerizable unsaturated bonds in the molecule further include the general formula (a)

(Wherein, R represents an ethylene group or a propylene group, and m and n each independently represents an integer of 1 to 20), a diacrylate of an alkylene oxide adduct of bisphenol A, represented by the general formula (b )

(Wherein m and n each independently represents an integer of 1 to 10), an epichlorohydrin modified product of bisphenol A and an addition esterified product of acrylic acid, bisphenol A dimethacrylate, 1,4-butanediol Diacrylate, 1,3-butylene glycol diacrylate, diethylene glycol dimethacrylate, glycerol dimethacrylate, neopentyl glycol diacrylate, general formula (c)

(Wherein, R represents an ethylene group or a propylene group, and m and n each independently represents an integer of 1 to 20) diacrylate of an alkylene oxide adduct of phosphoric acid represented by the general formula (d )

(Wherein m and n each independently represents an integer of 1 to 10), an epichlorine modified product of phthalic acid and an addition ester of acrylic acid, diacrylate of polyethylene glycol, dimethacrylate of polypropylene glycol , Tetraethylene glycol diacrylate, general formula (e)

(Wherein m and n each independently represents an integer of 1 to 20) 1,6-hexanediol epichlorine modified product and acrylic acid addition esterified product (acylyl group in one molecule) 2), trimethylolpropane triacrylate, pentaerythritol triacrylate, general formula (f)

(Wherein R represents an ethylene group or a propylene group, and three m's each independently represents an integer of 1 to 20), a triacrylate of an alkyne oxide adduct of phosphoric acid represented by the general formula ( g)

(Wherein R represents an ethylene group or a propylene group, and m, m ′, and m ″ each independently represents an integer of 1 to 20), a triacrylate of an alkylene oxide adduct of trimethylolpropane. , Tris (methacryloxyethyl) isocyanurate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, etc. These monomers may be used alone or in combination of two or more. Can be used.

In addition to the above acrylic acid derivatives, monomers having one polymerizable unsaturated bond in the molecule such as acrylonitrile, styrene, vinyl acetate, ethylene, propylene can be used. In addition, monomers other than the acrylic acid derivatives described above and having two or more polymerizable unsaturated bonds in the molecule (such as divinylbenzene) can also be used.
In the above, in order to obtain the effect in the present invention, the use amount of the monomer other than the acrylic acid derivative is preferably 90% by weight or less, more preferably 50% by weight or less, and more preferably 20% by weight. % By weight or less is preferred.
The amount of the monomer having two or more polymerizable unsaturated bonds in the molecule is preferably 10% by weight or less, more preferably 5% by weight or less, based on the total amount of the monomers used. When 10 wt% or more is used, the protective member tends to tear easily due to impact.

  The resin material in the present invention can be obtained by polymerizing the acrylic acid derivative described above in the presence of the acrylic acid derivative polymer. The acrylic acid derivative used at this time is as described above, and the monomers other than the acrylic acid derivative and the preferred use amount thereof are as described above, and the polymerizable unsaturated bond that can be used is a molecule. The monomer having two or more in the same and the preferred use amount thereof are the same as described above.

  15 to 89.9 parts by weight of acrylic acid derivative is used for 10 to 80 parts by weight of the acrylic acid derivative polymer, and the polymerization initiator is used in an amount of 0.1 to 5 parts by weight and 100 parts by weight as a whole. It is preferred that The blending is more preferably 30 to 50 parts by weight of an acrylic acid derivative polymer, 45 to 69.9 parts by weight of an acrylic acid derivative, and 0.1 to 5 parts by weight of a polymerization initiator.

  As a polymerization method of the above-mentioned monomer, known polymerization methods such as solution polymerization, emulsion polymerization and bulk polymerization can be used. These methods can also be used for the synthesis of the acrylic acid derivative polymer.

As the polymerization initiator, a photopolymerization initiator can be used, and it can be selected from known materials such as benzophenone, anthraquinone, benzoin, sulfonium salt, diazonium salt, onium salt and the like.
More specifically, as a photopolymerization initiator, benzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone (Michler ketone), N, N-tetraethyl-4,4′-diaminobenzophenone, 4-methoxy -4'-dimethylaminobenzophenone, α-hydroxyisobutylphenone, 2-ethylanthraquinone, t-butylanthraquinone, 1,4-dimethylanthraquinone, 1-chloroanthraquinone, 2,3-dichloroanthraquinone, 3-chloro-2-methyl Aromatic ketone compounds such as anthraquinone, 1,2-benzoanthraquinone, 2-phenylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, thioxanthone, 2-chlorothioxanthone, 1-hydroxycyclohexyl phenyl ketone Benzoin compounds such as benzoin, methylbenzoin and ethylbenzoin, benzoin ether compounds such as benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether and benzoin phenyl ether, benzyl, 2,2-diethoxyacetophenone, benzyldimethyl ketal, β- ( Acridine-9-yl) acrylic acid diester compounds, 9-phenylacridine, 9-pyridylacridine, acridine compounds such as 1,7-diacridinoheptane, 2- (o-chlorophenyl) -4,5-diphenylimidazole 2-mer, 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o -Methoxy Enyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, 2,4-di (p-methoxyphenyl) 5-phenylimidazole dimer 2,4,5-tria such as 2- (2,4-dimethoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methylmercaptophenyl) -4,5-diphenylimidazole dimer Reel imidazole dimer, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1 -Propane etc.

  A thermal polymerization initiator may be used as the polymerization initiator. The thermal polymerization initiator is an initiator that generates radicals by heat, and specifically includes benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl. Peroxydicarbonate, di (2-ethoxyethyl) peroxydicarbonate, t-butylperoxyneodecanoate, t-butylperoxybivalate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl Examples thereof include organic peroxides such as peroxide and diacetyl peroxide. Also, 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane-1-carbonyl). 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2′-azobis (2-methylpropionate) ), 4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis (2-hydroxymethylpropionitrile), 2,2′-azobis [2- (2-imidazolin-2-yl) ) Propane].

The resin material used in the present invention preferably has a glass transition temperature (Tg) of 0 ° C. or lower. When the glass transition temperature exceeds 0 ° C., the protective member becomes hard and the protective member is easily torn by impact. Tg is more preferably -20 to -60 ° C.
The weight average molecular weight of the resin material used in the present invention is preferably 100,000 or more, and more preferably 200,000 to 700,000.
For the purpose of increasing the adhesiveness, it is preferable to add a polar group to the polymer molecule used as the resin material used in the present invention. There are polar groups such as hydroxyl group, carboxyl group, cyano group, glycidyl group, etc., as polar groups that increase the adhesion to glass. These groups are introduced by copolymerizing monomers having such groups. can do.
In order to use the protective member in the present invention for a display device, the protective member preferably has a visible light transmittance of 80% or more. For that purpose, it is preferable that the visible light transmittance of the mixed solution of the monomer as a raw material and the polymerization initiator is 80% or more (the same applies to the production of the acrylic acid derivative polymer).

  The protective member in the present invention is preferably a film or sheet having a thickness of 0.5 mm to 3 mm. This can be produced by casting a mixture of the monomer raw material and the polymerization initiator. Moreover, it can manufacture by applying desired thickness using a general purpose coating machine, and irradiating an ultraviolet-ray or an electron beam.

A protective member is laminated | stacked with an antireflection layer or an electromagnetic wave shielding layer, and can add another function as a multilayered object.
As the electromagnetic wave shielding layer, a known electromagnetic wave can be used as long as it has an electromagnetic wave shielding property with a visible light transmittance of 60% or more. A transparent conductive film, a conductive fiber mesh, a mesh made of a conductive ink, or the like can be used, but a metal mesh is most preferable from the viewpoint of high transparency and high electromagnetic shielding properties. The metal mesh is produced by applying an adhesive to one or both of a transparent base material such as a polyester film and a conductive metal foil such as copper foil or aluminum foil, and then bonding the two together, and then the metal foil is subjected to a chemical etching process. Obtained by etching. At this time, it is preferable to use a surface-roughened conductive metal foil. Lamination is performed such that the roughened surface faces the adhesive layer. If a metal mesh is produced by the above etching, a resin is applied thereon, particularly preferably a resin that can be cured by ultraviolet rays or electron beams, and by curing by irradiation with ultraviolet rays or electron beams, It is preferable to make the adhesive layer to which the roughened surface has been transferred transparent.
Further, the antireflection layer may be a layer having antireflection properties such that the visible light reflectance is 5% or less, and is processed by a known antireflection method on a transparent substrate such as a transparent plastic film. Layers can be used.
The electromagnetic wave shielding layer and the antireflection layer can be appropriately laminated and used. In this case, the electromagnetic wave shielding layer and the antireflection layer may be laminated on one side of the transparent substrate, or may be laminated separately on both sides of the transparent substrate. When the electromagnetic wave shielding layer and the antireflection layer are laminated on one of the transparent substrates, the lamination order of the electromagnetic wave shielding layer and the antireflection layer is arbitrary.
The protective member in the present invention has the antireflection layer or electromagnetic wave shielding layer of the transparent substrate formed on the antireflection layer or electromagnetic wave shielding layer formed on the transparent substrate as described above. It can be used as a multifunctional multi-layered product by laminating on the surface opposite to the surface. It is preferable that the layer made of the protective member in the present invention is the outermost layer.
These layers can be laminated | stacked with a roll laminating or a single wafer bonding machine through the adhesion layer between each layer. Furthermore, the multilayer material laminated | stacked with the roll lamination and the sheet | seat bonding machine can be bonded to the display front surface or the display front board using a roll laminator or a sheet bonding machine. In this case, it is preferable that the layer made of the protective member of the present invention is bonded so as to face the display front surface or the display front plate.

Into a reaction vessel equipped with a condenser, a thermometer, a stirrer, a dropping funnel and a nitrogen injection tube, 100 parts by weight of 2-ethylhexyl acrylate and 80 parts by weight of toluene were placed, and while bubbling nitrogen at a volume of 100 ml / min, toluene 20 0.5 parts by weight of azobisoisobutyronitrile dissolved in parts by weight was added dropwise. After completion of the dropwise addition, a polymerization reaction was performed for 2 hours. The polymerization reaction was performed at 70 ° C. Thereafter, toluene was removed to obtain a 2-ethylhexyl acrylate polymer having a weight average molecular weight of 200,000.
10 parts by weight of the obtained 2-ethylhexyl acrylate polymer, 50 parts by weight of 2-ethylhexyl acrylate, 1 part by weight of 1,6-hexanediol diacrylate, and 0.5 parts by weight of Irgacure 184 (manufactured by Ciba-Geigy Japan) are added. And stirred to obtain a homogeneous solution. The solution was put in a non-alkali glass mold and irradiated with 2J of ultraviolet light to prepare a protective member. In addition, the thickness of the produced protection member was 1 mm.

  In Example 1, a protective member was produced in the same manner as in Example 1 except that the blending amount of 2-ethylhexyl acrylate polymer was changed to 30 parts by weight.

  In Example 1, a protective member was produced in the same manner as in Example 1 except that the blending amount of 2-ethylhexyl acrylate polymer was changed to 50 parts by weight.

  In Example 1, a protective member was produced in the same manner as in Example 1 except that toluene was changed to ethyl acetate. The obtained 2-ethylhexyl acrylate polymer had a weight average molecular weight of 500,000.

  In Example 4, a protective member was produced in the same manner as in Example 4 except that the amount of 2-ethylhexyl acrylate polymer was changed to 30 parts by weight.

  In Example 4, a protective member was produced in the same manner as in Example 4 except that the blending amount of 2-ethylhexyl acrylate polymer was changed to 50 parts by weight.

  100 parts by weight of 2-ethylhexyl acrylate and 100 parts by weight of toluene were placed in a reaction vessel equipped with a cooling tube, a thermometer, a stirrer, a dropping funnel and a nitrogen injection tube, and bubbling nitrogen at a volume of 100 ml / min. 1 part by weight of isobutyronitrile was added and a polymerization reaction was carried out for 2 hours. Thereafter, toluene was removed to obtain 2-ethylhexyl acrylate polymer having a weight average molecular weight of 50,000. A protective member was produced in the same manner as in Example 1 except that this polymer was used in place of the 2-ethylhexyl acrylate polymer having a weight average molecular weight of 200,000.

(Comparative Example 1)
99 parts by weight of 2-ethylhexyl acrylate, 1 part by weight of 1,6-hexanediol diacrylate, and 0.5 parts by weight of Irgacure 184 (manufactured by Ciba-Geigy Japan) were added and stirred to obtain a uniform solution. The solution was put in a non-alkali glass mold and irradiated with ultraviolet rays to produce a protective member. In addition, the thickness of the produced protection member was 1 mm.

(Comparative Example 2)
A protective member was produced in the same manner as in Comparative Example 2 except that 2-ethylhexyl acrylate was changed to lauryl acrylate in Comparative Example 1.

(Comparative Example 3)
The impact resistance was evaluated with a glass having a thickness of 3 mm without bonding a protective member.

The characteristics of the protective member obtained above were measured as follows.
(Glass-transition temperature)
The glass transition temperature was measured with a thermomechanical analyzer (RSA2 type manufactured by Scientific FE). The heating rate was measured at 5 ° C./min.
(Visible light transmittance)
The transmittance of the produced electromagnetic wave shielding member was measured with a spectrocolorimeter CM-508d manufactured by Minolta.
(Adhesive force)
According to JIS Z 0237, the produced electromagnetic wave shielding member was bonded to glass, and then measured by a 90 ° peeling test. Measurement was performed at a pulling speed of 50 mm / min and a sample width of 25 mm.
(Impact resistance)
The 3 mm glass bonded with the produced protective member was placed on the surface plate. Thereafter, a steel ball having a weight of 500 g was dropped from an arbitrary height, the maximum height h (m) at which the glass bonded with the protective member was not broken was measured, and the durable impact force was calculated using the following formula. . Moreover, the crack of the protective member was also evaluated at the same time. In addition, the antireflection layer (100 micrometers) and the electromagnetic wave absorption layer (150 micrometers) were bonded to the upper surface (opposite surface of glass bonding) of the protective member.

Durability impact force (J) = weight of steel ball (0.5 kg) × gravity acceleration (9.8 m / m ² ) × height of falling steel ball (hm)

表１に示すように、実施例１〜７は透明性、耐久衝撃力に優れ０．５Ｊの衝撃でも保護部材がさけることがなく、その保護能力が優れる。

As shown in Table 1, Examples 1 to 7 are excellent in transparency and durability impact force, and the protective member is not avoided even by an impact of 0.5 J, and the protective ability is excellent.

Claims (9)

A resin material obtained by polymerizing 15 to 89.9 parts by weight of an acrylic acid derivative using 0.1 to 5 parts by weight of a polymerization initiator in the presence of 10 to 80 parts by weight of an acrylic acid derivative polymer. Protective member. The protective member according to claim 1, wherein the acrylic acid derivative polymer has a weight average molecular weight of 100,000 or more. The protective member according to claim 1, wherein the polymerization initiator is a photopolymerization initiator. The protective member according to claim 1, which has a glass transition temperature of 0 ° C. or lower. The protective member according to claim 1, which has adhesiveness. The protective member according to claim 1, wherein the visible light transmittance is 80% or more. A protective member laminate comprising the protective member according to claim 1 and an antireflection layer or an electromagnetic wave shielding layer. The display apparatus formed by bonding the protection member laminated body of Claim 7 on the surface. The display device according to claim 8, wherein the display to which the protective member laminate is bonded is a plasma display panel.