TWI679459B - Laminate and liquid crystal display device - Google Patents

Abstract

The present invention provides a laminated body which does not generate a solvent crack in a protective film constituting a polarizing plate, and also provides a liquid crystal display device having excellent visibility combined with such a laminated body.

A laminated body is a laminated body having a substrate, an active energy ray-curable adhesive layer, and a polarizing plate in order. The polarizing plate is a polarizing plate having a polarizer and a protective film of a cyclic olefin resin, and satisfies the following formula. : Re (550) ≧ -38.37ln (S) -434.4 δ + 8063. The S system refers to the solubility of the polymerizable monomer contained in the active energy ray-curable adhesive composition that forms the active energy ray-curable adhesive layer with respect to 100 g of water at 25 ° C. Re (550) represents an in-plane retardation value of a protective film of a cyclic olefin-based resin having a wavelength of 550 nm. The δ system indicates the SP value.

Description

Laminated body and liquid crystal display device

The present invention relates to a laminated body and a liquid crystal display device.

Liquid crystal display devices are various devices incorporated in mobile devices such as mobile phones, personal computers, and large televisions. In mobile devices such as mobile phones, a cover glass and a cover glass with a touch sensor module (hereinafter referred to as a touch panel) are arranged on the visible side surface. Liquid optically clear adhesives (hereinafter referred to as LOCA) are arranged between the liquid crystal panels, and many of them are hardened. By using LOCA, it is possible to suppress air bubbles from biting between the liquid crystal panel, the cover glass and the touch panel, thereby reducing light loss due to reflection.

However, when the LOCA is disposed between the cover glass, the touch panel and the liquid crystal panel, the following cases may occur: the main surface of the protective film of the polarizing plate constituting one of the outermost members of the liquid crystal panel is in contact with the LOCA, or Since the LOCA is a liquid, the liquid of the LOCA flows down to the side of the polarizing plate. Furthermore, it is known that the main surface and side surfaces of the polarizing plate are in contact with LOCA, and the adhesive component of the LOCA causes the protective film constituting the surface of the polarizing plate to be dissolved. The agent is cracked, and visibility of the display device is reduced.

Patent Document 1 discloses a method for forming a cationically polymerizable protective film on both sides of a protective film constituting a polarizing plate, and increasing the in-plane retardation value Re of the protective film to 50 nm or more to improve solvent crack resistance .

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2014-32270

Depending on the type of the polymerizable monomer contained in the adhesive, the content ratio of the polymerizable monomer, and the type of the protective film constituting the polarizing plate, the problem of cracking of the solvent and lowering the visibility of the liquid crystal display device still occurs. Even if a cationically polymerizable protective film is formed on both sides of the protective film, contact between the side surface of the polarizing plate and the adhesive cannot be avoided, and the problem of solvent cracking at the ends of the polarizing plate still exists.

The present invention includes the following matters.

S_k係表示相對於25℃的水100g，在形成前述活性能量線硬化型接著劑層之活性能量線硬化型接著劑組成物所含有之第k個聚合性單體之溶解度，a_k係表示前述第k個聚合性單體的重量份，Re(550)係表示在波長550nm之環狀烯烴系樹脂的保護膜的面內相位差值，δ係表示依照Y-MB法所計算得到之前述環狀烯烴系樹脂的保護膜的SP值，又，S的單位係設作g，Re(550)的單位係設作nm，δ的單位係設作(MPa)^1/2]。 [1] A laminated body, which is a laminated body having a substrate, an active energy ray-curable adhesive layer, and a polarizing plate in order. The polarizing plate is a polarizing plate having a polarizer and a protective film of a cyclic olefin resin. The following formula Re (550) ≧ -38.37ln ( S ) -434.4 δ + 8063 (1) [In formula (1), S is represented by

S _k represents the system with respect to water of 100g 25 ℃, followed by forming the hardened solubility of the active agent contained in the layer of energy ray curable adhesive composition of polymerizable monomers k of active energy ray, represented by line A _k The weight part of the k-th polymerizable monomer, Re (550) represents an in-plane retardation value of a protective film of a cyclic olefin resin having a wavelength of 550 nm, and δ represents the foregoing calculated by the Y-MB method. The SP value of the protective film of the cyclic olefin resin, the unit of S is set to g, the unit of Re (550) is set to nm, and the unit of δ is set to (MPa) ^1/2 ].

[2] The laminated body according to [1], wherein the active energy ray-curable adhesive layer is a layer covering a main surface and a side surface of the polarizing plate.

[3] The laminate according to [1] or [2], wherein the active energy ray-curable adhesive composition contains a radical polymerizable compound.

[4] The laminated body according to any one of [1] to [3], wherein the protective film of the cyclic olefin-based resin has an SP value of 17 to 19.

[5] The laminated body according to any one of [1] to [4], wherein the shape of the laminated body is rectangular, the length of the long side is 5 cm or more, and the length of the short side is 3 cm or more.

[6] A liquid crystal display device comprising the multilayer body according to any one of [1] to [5].

According to the present invention, it is possible to provide a laminated body that does not cause solvent cracks in the protective film constituting the polarizing plate, and to provide a liquid crystal display device having excellent visibility by incorporating the laminated body.

1‧‧‧ substrate

2‧‧‧ Active Energy Ray Hardening Adhesive Layer

3‧‧‧Protective film for cyclic olefin resin

4‧‧‧ polarizer

5‧‧‧ Other protective film

6‧‧‧ Adhesive

7‧‧‧ LCD cell

8‧‧‧ Customized Polarizer

10‧‧‧ polarizing plate

11‧‧‧ polarizer with adhesive

20‧‧‧ LCD panel

100‧‧‧Laminated body

FIG. 1 is a schematic diagram showing an example of a layer structure of a laminated body of the present invention.

Fig. 2 is a schematic diagram showing an example of a layer structure of a laminated body of the present invention.

FIG. 3 is a graph showing the relationship between the in-plane retardation value Re (550) and the solubility S according to the SP value of the protective film of the cyclic olefin-based resin in the examples and comparative examples.

The laminated body of the present invention has a substrate, an active energy ray-curable adhesive layer, and a polarizing plate in this order. The polarizing plate is a protective film having a polarizer and a cyclic olefin resin. Hereinafter, each member which comprises the laminated body of this invention is demonstrated.

[Substrate]

The substrate used in the laminated body of the present invention is preferably an optically transparent substrate. Optically transparent means having a transmittance of 85% in a wavelength range of 460 to 720 nm. The substrate thickness is generally 0.5 to 5 mm. The refractive index of the substrate is preferably close to the refractive index of the active energy ray-curable adhesive layer and the liquid crystal panel, and more preferably 1.4 to 1.7.

The substrate may be a glass substrate or a resin substrate. Examples of the glass forming the glass substrate include borosilicate acid and soda lime. Specific examples include EAGLE XG (registered trademark) (Corning) and JADE (registered trademark) (Corning). Examples of the resin substrate include acrylic resin films such as polyester films such as polyethylene terephthalate, polycarbonate films, and polymethyl methacrylate films.

The substrate may be a touch panel. The touch panel can be a conventional one, and usually includes a conductive layer disposed between two transparent substrates. Examples of the two transparent substrates include the aforementioned glass substrates, and examples of the conductive layer include indium tin oxide.

[Active energy ray hardening type adhesive layer]

The active energy ray-curable adhesive layer is a layer formed between the substrate and the polarizing plate, and is used to fill the air gap between the substrate and the polarizing plate, and is a layer adhering the substrate and the polarizing plate. By filling the air gap with an active energy ray-curable adhesive layer, it is possible to improve impact resistance or reduce light loss due to reflection. The active energy ray-curable adhesive layer can be formed by irradiating the active energy ray-curable adhesive composition with an active energy ray to harden it. The active energy ray-curable adhesive layer may be formed on a polarizing plate described later, but the liquid composition of the adhesive composition causes vertical liquid flow, and is usually also formed on the side surface of the polarizing plate. That is, the active energy ray-curable adhesive layer is mostly provided so as to cover the surface of a polarizing plate described later.

The thickness of the active energy ray-curable adhesive layer is generally 30 to 200 μm, preferably 50 to 200 μm, and more preferably 80 to 150 μm. The active energy ray hardening type adhesive layer is preferably optically transparent. The term "optically transparent" means that it has a transmittance of 85% in the range of 460 to 720 nm. The refractive index of the active energy ray-curable adhesive layer is preferably close to the refractive index of the substrate and the liquid crystal panel, and more preferably 1.4 to 1.7.

[Active energy ray hardening type adhesive composition]

The active energy ray-curable adhesive composition is liquid and contains a polymerizable monomer. Examples of the polymerizable monomer include a cationic polymerizable compound and a radical polymerizable compound, and a radical polymerizable compound is preferred. Examples of the cationically polymerizable compound include compounds having at least one oxetane ring (4-membered cyclic ether) in the molecule (hereinafter, referred to as oxetane compounds), and having at least one epoxy in the molecule. Compounds of ethane ring (3-membered cyclic ether) (hereinafter referred to as epoxy compounds) and the like. As the radical polymerizable compound, a compound (hereinafter, referred to as a (meth) acrylic compound) having at least one (meth) acryloxy group in the molecule is preferable. In the present specification, the meaning of (meth) acryloxy is methacryloxy or acryloxy, and the other terms (meth) are the same.

Examples of the (meth) acrylic compound include a (meth) acrylic acid ester monomer having at least one (meth) acryloxy group in the molecule, and at least two (meth) acryloxy groups in the molecule. (Meth) acrylate oligomers and the like. These systems can be used alone or in combination of two or more. When two or more types are used in combination, the number of (meth) acrylate monomers may be two or more, and the number of (meth) acrylate oligomers may be two or more. Of course, one type of (meth) acrylate monomer may be used. These are used in combination with one or more kinds of (meth) acrylate oligomers.

Examples of the (meth) acrylic acid ester monomer include A monofunctional (meth) acrylate monomer having one (meth) acryloxy group in a molecule, a bifunctional (meth) acrylate monomer having two (meth) acryloxy groups in a molecule, and A polyfunctional (meth) acrylate monomer having three or more (meth) acryloxy groups in the molecule.

Examples of the monofunctional (meth) acrylate monomer include tetrahydrofuran methyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2- or 3-hydroxypropyl (meth) acrylate, ( 2-hydroxybutyl meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, methyl (meth) acrylate, (meth) Ethyl acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, tertiary butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate Ester, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecy (meth) acrylate, dodecyl (meth) acrylate, (meth) acrylic ring Hexyl ester, 1,4-cyclohexanedimethanol monoacrylate, dicyclopentyl (meth) acrylate, dicyclopentenyl (meth) acrylate, benzyl (meth) acrylate, (meth) acrylic acid Isoamyl ester, phenoxyethyl (meth) acrylate, dicyclopentenyloxy (meth) acrylate, dimethylaminoethyl (meth) acrylate, ethyl carbitol (methyl ) Acrylic ester, trimethylolpropane- (meth) propane Acrylates, neopentyl alcohol (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate, and the like.

As the monofunctional (meth) acrylate monomer, a carboxyl group-containing (meth) acrylate monomer can be used. Examples of the carboxyl group-containing monofunctional (meth) acrylate monomer include 2- (meth) acryloxyethyl phthalic acid, 2- (meth) acryloxyethyl hexahydrophthalic acid, Carboxyethyl (meth) acrylate, 2- (meth) acryloxyethyl succinic acid, N- (meth) acryloxy -N ', N'-dicarboxymethyl-p-phenylenediamine, 4- (meth) propenyloxyethyl trimellitic acid, and the like.

烷-2,5-二基二(甲基)丙烯酸酯[別名：二

烷二醇二(甲基)丙烯酸酯]、羥基三甲基乙醛與三羥甲基丙烷的縮醛化合物[化學名：2-(2-羥基-1,1-二甲基乙基)-5-乙基-5-羥甲基-1,3-二

烷]的二(甲基)丙烯酸酯、三(羥乙基)異三聚氰酸酯二(甲基)丙烯酸酯等。 Examples of the bifunctional (meth) acrylate monomer include ethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, and 1,4-butanediol di (meth) acrylate. (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trihydroxy Methyl propane di (meth) acrylate, neopentaerythritol di (meth) acrylate, bistrimethylolpropane di (meth) acrylate, diethylene glycol di (meth) acrylate, three Ethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) Acrylate, polytetramethylene glycol di (meth) acrylate, silicone di (meth) acrylate, bis (meth) acrylate of neopentyl glycol trimethylacetate, 2,2- Bis [4- (meth) propenyloxyethoxyethoxyphenyl] propane, 2,2-bis [4- (meth) propenyloxyethoxyethoxycyclohexyl] propane, Hydrogenated dicyclopentadienyl di (meth) acrylate, tricyclodecane dimethanol di (meth) propane Enoate, 1,3-di

Alkane-2,5-diyldi (meth) acrylate [alias: di

Alkanediol di (meth) acrylate], acetal compound of hydroxytrimethylacetaldehyde and trimethylolpropane [chemical name: 2- (2-hydroxy-1,1-dimethylethyl)- 5-ethyl-5-hydroxymethyl-1,3-di

Alkanes] di (meth) acrylate, tris (hydroxyethyl) isotricyanate di (meth) acrylate, and the like.

Examples of the trifunctional or higher polyfunctional (meth) acrylate monomers include glycerol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, and bistrimethylolpropane tri ( (Meth) acrylate, bistrihydroxy Methylpropane tetra (meth) acrylate, neopentaerythritol tri (meth) acrylate, neopentaerythritol tetra (meth) acrylate, dinepentaerythritol tetra (meth) acrylate, dixin Poly (meth) acrylates of pentaerythritol penta (meth) acrylate and dinepentaerythritol hexa (meth) acrylate with tri- or more functional aliphatic polyols. In addition, poly (meth) acrylates of tri- or higher-functional halogen-substituted polyols, tri (meth) acrylates of alkylene oxide adducts of glycerol, and alkylene oxide additions of trimethylolpropane can be cited. Tris (meth) acrylate, 1,1,1-tris [(meth) acryloxyethoxyethoxyethoxy] propane, tris (hydroxyethyl) isotricyanate tris (methyl) Based) acrylates and the like.

Examples of the (meth) acrylate oligomer include a urethane (meth) acrylate oligomer, a polyester (meth) acrylate oligomer, and an epoxy (meth) acrylate oligomer Things.

The so-called urethane (meth) acrylate oligomer is a compound having a urethane bond (-NHCOO-) and at least two (meth) acrylic acid groups in the molecule. Specifically, it is a product of a urethanization reaction of a hydroxyl-containing (meth) acrylate monomer having at least one (meth) acryloxy group and at least one hydroxyl group in a molecule, and a polyisocyanate, The isocyanate-containing urethane compound at the terminal obtained by reacting a polyol with a polyisocyanate, and a (meth) acrylate having at least one (meth) acryloxy group and at least one hydroxyl group each in the molecule A product of a monomer and a urethane reaction.

Examples of the hydroxyl-containing (meth) acrylate monomer used in the urethanation reaction include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and (methyl) ) 2-hydroxybutyl acrylate, (meth) 2-hydroxy-3-phenoxypropyl acrylate, glycerol di (meth) acrylate, trimethylolpropane di (meth) acrylate, neopentyl alcohol tri (meth) acrylate, dineopentyl Tetraol penta (meth) acrylate and the like.

Examples of the polyisocyanate supplied to the urethanization reaction with such a hydroxyl-containing (meth) acrylate monomer include hexamethylene diisocyanate, lysine diisocyanate, and isophorone di Isocyanates, dicyclohexylmethane diisocyanates, toluene diisocyanates, xylylene diisocyanates, and diisocyanates obtained by hydrogenating aromatic isocyanates in these diisocyanates (e.g., hydrogenated toluene diisocyanates, hydrogenated xylylenes) Diisocyanate, etc.), diphenyl or tri-isocyanate such as triphenylmethane triisocyanate, dibenzylbenzene triisocyanate, and the polyisocyanate obtained by quantifying the above-mentioned diisocyanate.

In addition, examples of the polyhydric alcohol used to form a terminal isocyanate-containing urethane compound by reaction with a polyisocyanate include aromatic, aliphatic, and alicyclic polyols, and polyesters. Polyols, polyether polyols, and the like. Examples of the aromatic polyol include 1,4-benzenedimethanol, 1,3-benzenedimethanol, 1,2-benzenedimethanol, 4,4'-naphthalenedimethanol, and 3,4'-naphthalenedimethanol. Methanol and so on. Examples of the aliphatic and alicyclic polyols include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and neopentyl glycol. , Trimethylolethane, trimethylolpropane, ditrimethylolpropane, neopentaerythritol, dinepentaerythritol, dimethylol heptane, dimethylolpropanoic acid, dimethylol Butyric acid, glycerol, hydrogenated bisphenol A, etc.

Polyester polyols can be obtained by the dehydration condensation reaction of the above-mentioned polyols with a polycarboxylic acid or its anhydride. As polycarboxylic acids or their anhydrides, Purine acid, succinic anhydride, adipic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, trimellitic acid, trimellitic anhydride, pyromelic acid, pyromellar anhydride, Phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, hexahydrophthalic acid, hexahydrophthalic anhydride, etc.

Examples of the polyether polyols include polyalkylene glycols, and polyoxyalkylene-modified polyols obtained by reacting the above-mentioned polyols or dihydroxybenzenes with alkylene oxides.

The so-called polyester (meth) acrylate oligomer is a compound having at least two ester bonds in the molecule and at least two (meth) acryloxy groups. Specifically, it can be obtained by the dehydration condensation reaction of (meth) acrylic acid, a polycarboxylic acid or its anhydride, and a polyhydric alcohol. Examples of the polycarboxylic acid or its anhydride used in the dehydration condensation reaction include succinic acid, succinic anhydride, adipic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, trimellitic acid Formic acid, trimellitic anhydride, pyromelic acid, pyromellar anhydride, hexahydrophthalic acid, hexahydrophthalic anhydride, phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, etc. Examples of the polyhydric alcohol used in the dehydration condensation reaction include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and neopentyl Alcohol, trimethylolethane, trimethylolpropane, bistrimethylolpropane, neopentaerythritol, dinepentaerythritol, dimethylol heptane, dimethylolpropionic acid, dimethylol Butyric acid, glycerol, hydrogenated bisphenol A, etc.

The epoxy (meth) acrylate oligomer has at least two (meth) acryloxy groups in the molecule and can be obtained by addition reaction of poly (glycidyl) ether with (meth) acrylic acid. Examples of the polyglycidyl ether used in the addition reaction include ethylene glycol diglycidyl ether and propylene glycol diglycidyl Ether, tripropylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, bisphenol A diglycidyl ether, and the like.

The total amount of the radical polymerizable compound is preferably 20 to 80 parts by weight, and more preferably 30 to 70 parts by weight based on 100 parts by weight of the active energy ray-curable adhesive composition.

The active energy ray-curable adhesive composition preferably contains a polymerization initiator. When a radical polymerizable compound is contained as the polymerizable monomer, it is preferable to include a radical polymerization initiator, and when a cationic polymerizable compound is contained as the polymerizable monomer, it is preferable to include a cationic polymerization initiator. The cationic polymerization initiator may be one capable of generating a cationic species or a Lewis acid by irradiating an active energy ray to start a polymerization reaction of a cationic polymerizable monomer including an epoxy compound as a representative example. The radical polymerization initiator may be one that can start polymerization of a radically polymerizable compound such as a (meth) acrylic compound by irradiating an active energy ray, and a conventional one can be used. Examples of the radical polymerization initiator include acetophenone, 3-methylacetophenone, benzyldimethylketal, and 1- (4-isopropylphenyl) -2-hydroxy-2-methyl Propane-1-one, 2-methyl-1- [4- (methylthio) phenyl-2-N-morpholinylpropane-1-one, and 2-hydroxy-2-methyl-1-benzene Acetophenone-based initiators for propan-1-one; such as diphenylketones, 4-chlorodiphenylketones, and 4,4'-diaminodiphenylketones ; Benzoin ether based initiators such as benzoin propyl ether and benzoin ethyl ether; such as thioxanthone based initiators in 4-isopropylthioanthone; and others Xanthone, fluorenone, camphorquinone, benzaldehyde, anthraquinone, etc.

Free-radical polymerization initiators can be easily obtained commercially For example, "IRGACURE (registered trademark) 184", "IRGACURE (registered trademark) 907", "DAROCUR (registered trademark) 1173", "LUCIRIN (registered trademark) TPO", etc., which are manufactured by BASF Corporation, can be cited under their respective product names. .

The content of the radical polymerization initiator is generally 0.5 to 20 parts by weight, and preferably 1 to 6 parts by weight based on 100 parts by weight of the total amount of the radical polymerizable compound such as a (meth) acrylic compound. When the blending amount of the radical polymerization initiator is small, the curing is insufficient, and the adhesion between the active energy ray-curable adhesive layer and the polarizing plate tends to decrease.

The content of the cationic polymerization initiator is generally 0.5 to 20 parts by weight, and preferably 1 to 6 parts by weight based on 100 parts by weight of the total amount of the cation polymerizable compound such as an epoxy compound.

When the blending amount of the cationic polymerization initiator is small, curing is insufficient, and the adhesion between the active energy ray-curable adhesive layer and the polarizing plate tends to decrease.

The active energy ray hardening type adhesive agent composition system may contain a plasticizer, a photosensitizer, a leveling agent, an antioxidant, a stabilizer, a flame retardant, a viscosity adjuster, a foam suppressant, and an antistatic agent.

[Polarizer]

The polarizing plate constituting the laminated body of the present invention is a protective film having a polarizer and a cyclic olefin resin. The protective film of the cyclic olefin resin may be disposed on at least one side of the polarizer, or may be disposed on both sides. Moreover, a protective film may be provided only on one side of a polarizer, and this protective film may be used as a protective film of a cyclic olefin resin. A protective film of a cyclic olefin resin is disposed on the polarizer. For both sides, the protective film system of the cyclic olefin resin may be formed of the same resin or different resins. The protective film of a cyclic olefin resin is preferably one laminated on a polarizer.

The polarizing plate constituting the laminated body of the present invention may be a polarizing plate with an adhesive having an adhesive layer on its surface. The thickness of the adhesive layer is generally 3 to 30 μm, and preferably 5 to 25 μm. When the polarizing plate has an adhesive layer, the polarizing plate can be adhered to the liquid crystal cell by this.

The adhesive layer can be formed of an adhesive composition, and can include resins such as (meth) acrylic, rubber, urethane, ester, silicone, and polyvinyl ether as a main component. It consists of an adhesive composition. In particular, an adhesive composition using a (meth) acrylic resin having excellent transparency, weather resistance, and heat resistance as a matrix polymer is preferred. The adhesive composition may be an active energy ray hardening type or a thermosetting type.

The adhesive composition may contain a cross-linking agent, a polymerization initiator, a sensation agent, fine particles for imparting light-scattering properties, beads (resin particles, glass particles, etc.), glass fibers, adhesion-imparting agents, and filler (Metal powder and other inorganic powders, etc.), antioxidants, ultraviolet absorbers, dyes, pigments, colorants, defoamers, corrosion inhibitors, photopolymerization initiators and other additives.

[Polarizer]

The polarizer is preferably an optical film having the following properties: absorbing linearly polarized light having a vibration plane parallel to the optical axis, and transmitting linearly polarized light having a vibration plane orthogonal to the optical axis; specifically, A dichroic pigment (iodine or dichroic organic dye) is a polarizing plate formed by adsorbing and aligning a polyvinyl alcohol resin film.

The thickness of the polarizer is generally 2 μm or more and 30 μm or less, preferably 25 μm or less, more preferably 15 μm or less, even more preferably 10 μm or less, and particularly preferably 7 μm or less. In addition, in the case where a polarizing plate is used in which a dichroic dye is adsorbed and aligned on a polyvinyl alcohol-based resin layer, the polyvinyl alcohol-based resin can be extended, or a solution of the polyvinyl alcohol-based resin can be applied to the substrate. After it is allowed to dry, it is extended simultaneously with the substrate and the substrate is removed. When stretched simultaneously with the substrate, it is easy to manufacture a polarizer having a thickness of 7 μm or less.

Examples of the substrate include a polyethylene terephthalate film, a polycarbonate film, a cellulose triacetate film, a norbornene film, a polyester film, and a polystyrene film.

As the polyvinyl alcohol-based resin constituting the polyvinyl alcohol-based resin layer, a polyvinyl acetate-based resin can be saponified. Examples of the polyvinyl acetate-based resin include polyvinyl acetate, a homopolymer of vinyl acetate, and a copolymer of vinyl acetate and other monomers copolymerizable therewith. Examples of other monomers that can be copolymerized with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamide having an ammonium group.

The saponification degree of the polyvinyl alcohol resin is generally 80 mol% or more, preferably 90 to 99.5 mol%, and more preferably 94 to 99 mol%. When the degree of saponification is less than 80 mol%, the water resistance and humidity and heat resistance of the obtained polarizing plate are reduced. When the degree of saponification is more than 99.5 mol%, the dyeing speed becomes slower and productivity decreases, and a polarizer having sufficient polarizing performance cannot be obtained.

Polyvinyl alcohol resins can be partially modified modified polymers Vinyl alcohol can be used, for example, by modification with olefins such as ethylene and propylene; modification with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; and modification with alkyl esters of unsaturated carboxylic acids or acrylamide. And so on. The modification ratio of the polyvinyl alcohol resin is preferably less than 30 mol%, and more preferably less than 10%. When the modification is performed at more than 30 mol%, the dichroic pigment tends to be difficult to be adsorbed, and a polarizer having sufficient polarizing performance may not be obtained.

The average degree of polymerization of the polyvinyl alcohol resin is preferably about 100 to 10,000, more preferably 1500 to 8000, and even more preferably 2000 to 5000.

When the average polymerization degree is less than 100, it is difficult to obtain better polarizing performance. When the average polymerization degree is more than 10,000, the solubility of the solvent is deteriorated and it is difficult to form a polyvinyl alcohol resin layer.

As a polyvinyl alcohol-type resin, an appropriate commercial item can be used. As a suitable commercially available product, each of them is a trade name, and examples thereof include "PVA124" and "PVA117" manufactured by KURARAY Co., Ltd. (both are saponification degree: 98 to 99 mol%), "PVA624" (degree of saponification: 95 to 96 mole%), "PVA617" (degree of saponification: 94.5 to 95.5 mole%); "N-300" and "NH-18" made by Japan Synthetic Chemical Industry Co., Ltd. (Each one has a degree of saponification: 98 to 99 mol%), "AH-22" (degree of saponification: 97.5 to 98.5 mol%), "AH-26" (degree of saponification: 97 to 98.8 mol%) ,; "JC-33" (Saponification degree: 99 mol% or more), "JF-17", "JF-17L", and "JF-20" (any one is Saponification degree: 98 to 99 mole%), "JM-26" (degree of saponification: 95.5 to 97.5 mole%), "JM-33" (degree of saponification: 93.5 to 95.5 mole%), "JP-45" (degree of saponification : 86.5 to 89.5 mole%) and so on.

Examples of the dichroic dye contained in the polarizer (adsorption alignment) include iodine, dichroic organic dye, and the like. Examples of the dichroic organic dye include red BR, red LR, red R, pink LB, magenta BL, bay red GS, sky blue LG, lemon yellow, blue BR, blue 2R, sea halo blue RY, green LG, Purple LB, Purple B, Black H, Black B, Black GSP, Yellow 3G, Yellow R, Orange LR, Orange 3R, Scarlet GL, Scarlet KGL, Congo Red, Bright Purple BK, Super Blue G, Super Blue GL, Fresh Orange (SUPRA ORANGE) GL, Direct Sky Blue (DIRECT SKYBLUE), Direct Fast Orange (S), Direct Black (FAST BLACK). The dichroic pigments may be used alone or in combination of two or more.

[Protective film of cyclic olefin resin]

The protective film of a cyclic olefin-based resin included in the polarizing plate can be formed of a cyclic olefin-based resin. Examples of the monomer constituting the cyclic olefin resin include norbornene. To give examples of norbornene substitutes, the double bond position of norbornene is set to 1,2-position, and there are 3-substituted, 4-substituted, 4,5-disubstituted, etc. Pentadiene, dimethyl bridge octahydronaphthalene, etc. can also be used as a monomer constituting the cyclic olefin resin.

A cyclic olefin-based resin using norbornene-based monomers as a structural unit may or may not have a norbornane ring in its main chain. As the norbornene-based monomer formed in a cyclic olefin-based resin having no norbornane ring in the main chain, for example, a person who becomes a 5-membered ring by ring opening can be exemplified. Examples of the properties include norbornene, dicyclopentadiene, 1- or 4-methyl norbornene, and 4-phenylnorbornene. When the cyclic olefin-based resin is a copolymer, the arrangement state of the molecules is not particularly limited, and may be a random copolymer, a block copolymer, or a graft copolymer.

More specific examples of the cyclic olefin resin include a ring-opening polymer of a norbornene-based monomer, a ring-opening copolymer of a norbornene-based monomer and other monomers, and a maleic acid Modified polymer of addition, cyclopentadiene addition, etc., polymer or copolymer obtained by hydrogenating these, addition polymer of norbornene monomer, norbornene monomer Addition copolymers of polymer and other monomers. Examples of other monomers used in the copolymer include α-olefins, cycloolefins, and non-conjugated diene. Among these, the cyclic olefin-based resin is preferably a resin obtained by hydrogenating a ring-opening polymer using a norbornene-based monomer.

Cyclic olefin-based resins can be stretched to form a retardation film on the embryonic membrane formed by the cyclic olefin resin, and can also be made uniform by bonding a shrinkable film having a predetermined shrinkage ratio and applying heat shrinkage treatment. Higher retardation film with larger retardation value.

As cyclic olefin resins obtained by polymerizing norbornene-based monomers, there are "ZEONEX (registered trademark)" and "ZEONOR (registered trademark)" sold by Japan Zeon Co., Ltd. and JSR Corporation. "ARTON (registered trademark)" and so on. These cyclic olefin-based resin films and stretched films can also be obtained on the market, such as "ZEONOR film (registered trademark)" sold by Japan Zeon Co., Ltd., both of which are trade names, Sold by JSR Corporation "ARTON (registered trademark) film" sold, "ESUSHINA (registered trademark) retardation film" sold by Sekisui Chemical Industry Co., Ltd., and the like.

Further, as the protective film of the cyclic olefin resin, a film composed of a mixed resin containing two or more types of cyclic olefin resins and olefin resins, or a mixture of a cyclic olefin resin and another thermoplastic resin can be used. Thin film made of resin. For example, as a mixed resin containing two or more types of cyclic olefin-based resin and olefin-based resin, a mixture of the above-mentioned cyclic olefin-based resin and a chain aliphatic olefin-based resin may be mentioned. When a mixed resin of a cyclic olefin-based resin and another thermoplastic resin is used, another thermoplastic resin may be selected as appropriate according to the purpose. Specific examples include polyvinyl chloride resin, cellulose resin, polystyrene resin, acrylonitrile / butadiene / styrene copolymer resin, acrylonitrile / styrene copolymer resin, (methyl ) Acrylic resin, polyvinyl acetate resin, polyvinylidene chloride resin, polyamide resin, polyacetal resin, polycarbonate resin, modified polyphenylene ether resin, Polybutylene terephthalate resin, Polyethylene terephthalate resin, Polyphenylene sulfide resin, Polyfluorene resin, Polyetherfluorene resin, Polyetheretherketone resin, Polyaromatic Ester (polyarylate) resin, liquid crystal resin, polyimide resin, polyimide resin, polytetrafluoroethylene resin, etc. The thermoplastic resin may be used alone or in combination of two or more kinds. The thermoplastic resin may be used by any appropriate polymer modification. Examples of the polymer modification include copolymerization, cross-linking, modification of molecular terminals, and provision of stereoregularity.

Use of cyclic olefin resin and other thermoplastic resins When the resin is mixed, the content of other thermoplastic resins is generally 50% by weight or less, and more preferably 40% by weight or less, relative to the entire resin. By setting the content of other thermoplastic resins within this range, it is possible to obtain a retardation film having a small absolute value of the photoelastic coefficient, exhibiting good wavelength dispersion characteristics, and having excellent durability, mechanical strength, and transparency.

The protective film of a cyclic olefin resin may contain components, such as a residual solvent, a stabilizer, a plasticizer, an antioxidant, an antistatic agent, an ultraviolet absorber, a leveling agent, as needed.

The protective film of the cyclic olefin-based resin used in the present invention is preferably a retardation film having an in-plane retardation. Here, the in-plane retardation value Re is the refractive index of the in-plane slow axis direction of the film as nx, the refractive index of the in-plane fast axis direction as ny, the refractive index in the thickness direction as nz, and the film The thickness is set to d and defined by the following formula (2).

Re = (nx-ny) × d (2)

The phase difference also has a thickness direction phase difference value Rth, which is defined by the following formula (3). The Nz coefficient of the biaxiality standard of the retardation film is defined by the following formula (4).

Rth = [(nx + ny) / 2-nz] × d (3)

Nz coefficient = (nx-nz) / (nx-ny) (4)

When the Nz coefficient is 1, the stretched alignment system of the retardation film becomes completely uniaxial, and the solvent crack resistance effect obtained according to the present invention becomes the maximum. As the Nz coefficient becomes larger and becomes a biaxial alignment, the solvent crack resistance effect obtained according to the present invention becomes less likely to appear. Therefore, the protective film of the cyclic olefin-based resin used in the present invention has a Nz-based The number system is preferably in the range of 1 or more and 3 or less, and more preferably in the range of 1 or more and 2 or less. The phase difference value and the Nz coefficient may be values of a wavelength near the center of visible light, and in this specification, unless otherwise stated, values at a wavelength of 550 nm.

The protective film of the cyclic olefin-based resin having the refractive index anisotropy as described above can be obtained by using a film of the cyclic olefin-based resin to adopt a free-end longitudinal uniaxial extension, a tenter transverse uniaxial extension, and a double It can be obtained by extending in an appropriate manner such as axial extension, successive biaxial extension, etc. In addition to appropriately adjusting the extension magnification and extension speed, the pre-heating temperature, extension temperature, heat fixing temperature, And various changes in the cooling temperature and the respective change methods to obtain a protective film that imparts the required refractive index anisotropy.

The protective film of a cyclic olefin resin may be composed of a plurality of layers provided with a protective layer on the surface. The protective layer may be provided on one side or both sides of the protective film, but in terms of improving productivity, The protective film is preferably a protective film with a protective layer on one side or a single layer without a protective layer on the surface. Examples of the protective layer include a hard coat layer, an antiglare layer, an anti-reflection layer, an antistatic layer, and an antifouling layer.

[Other protective film]

When the polarizing plate of the laminated body of the present invention has a protective film of a cyclic olefin resin only on one side, a protective film made of a resin other than the protective film of a cyclic olefin resin (hereinafter, (Some cases called other protective films). At this time, the other protective films are preferably those laminated on the polarizer. In this specification, a protective film of a cyclic olefin resin and other materials are used. The case of a protective film is collectively referred to as a protective film.

As other protective films, cellulose acetate-based resins, chain olefin-based resins, acrylic resins, polyimide-based resins, polycarbonate-based resins, and polyester-based resins can be widely used in this field. A thermoplastic resin film formed of a material for forming a protective film. From the viewpoint of mass productivity and adhesiveness, the protective film is preferably a cellulose acetate resin film.

The cellulose acetate-based resin film is a film composed of cellulose partially or completely acetated, and examples thereof include a cellulose triacetate film and a cellulose diacetate film.

A commercially available cellulose acetate-based resin film can be used. Suitable commercially available products include "FUJITAC (registered trademark) TD80", "FUJITAC (registered trademark) TD80UF", "FUJITAC (registered trademark) TD80UZ") sold by Fuji Film Co., Ltd., and Konica Minolta Opto "KC8UX2M", "KC8UY" (both above, any of which are trade names) sold by the company limited by shares.

The chain olefin-based resin is a polymer having a chain olefin such as ethylene and propylene as a main monomer, and may be a homopolymer or a copolymer. Especially a homopolymer of propylene and a copolymer obtained by copolymerizing propylene with a small amount of ethylene are preferred.

Acrylic resin is a polymer using methyl methacrylate as the main monomer. It can be a homopolymer of methyl methacrylate, or it can be a copolymer of methyl methacrylate and acrylate such as methyl acrylate. Thing.

Polyimide resins are polymers having a fluorene imine bond in the main chain, and examples include polyamic acid (polyamic acid) that becomes a precursor of polyfluorene by polymerizing a tetracarboxylic dianhydride and a diamine. acid), and then dehydrated. Obtained by a cyclization reaction.

Polycarbonate resin-based polymers having a carbonate bond in the main chain include those obtained by condensation polymerization of bisphenol A and phosgene.

The polyester resin is a polymer obtained by condensation polymerization of a dibasic acid and a diol, and examples thereof include polyethylene terephthalate.

In addition, on the surface farther from the polarizer of other protective films, surface treatments such as anti-glare treatment, hard coating treatment, antistatic treatment, and anti-reflection treatment can be performed, and liquid crystal compounds and other high molecular weight compounds can be formed. And other coatings.

When the thickness of the protective film is too thin, the strength tends to decrease and the workability tends to be poor. When it is too thick, the transparency decreases, or the weight of the polarizing plate tends to increase. The thickness of the protective film of the polarizing plate of the present invention is generally 5 to 100 μm, preferably 10 to 80 μm, more preferably 50 μm or less, and particularly preferably 30 μm or less.

[Adhesive]

When a protective film and a polarizer are laminated, an adhesive can be used for bonding the protective film and the polarizer. Examples of the adhesive include an active energy ray-curable adhesive composition and an aqueous adhesive.

The active-energy-ray-curable adhesive composition may be the same as or different from the active-energy-ray-curable adhesive composition provided between the substrate and the polarizing plate.

Examples of the water-based adhesive include an adhesive composition containing a polyvinyl alcohol resin and a urethane resin as main components.

The thickness of the adhesive layer obtained after drying or hardening is generally 0.01 to 5 μm. When a water-based adhesive is used, the thickness can be 1 μm or less. On the other hand, when an active energy ray hardening type adhesive is used, it is preferably set to 2 μm or less, and more preferably set to 1 μm or less. When the adhesive layer is too thin, the adhesive layer may become insufficient. When the adhesive layer is too thick, the polarizing plate may have a poor appearance.

The present inventors have conducted investigations and studies on the entire protective film of the active energy ray-curable adhesive composition and the cyclic olefin-based resin, and found that the polymerizable monomer contained in the active energy ray-curable adhesive composition And the in-plane retardation value of the protective film of the cyclic olefin resin constituting the polarizing plate, in accordance with the solubility parameter (hereinafter referred to as the SP value) of the protective film of the cyclic olefin resin and satisfying the following formula (1) Choose to effectively prevent solvent cracking. Those skilled in the art can appropriately select a polymerizable monomer in accordance with the adhesive force, transmittance, and the like of the target active energy ray-curable adhesive layer, so as to satisfy the formula (1).

S_k係表示相對於25℃的水100g，在形成活性能量線硬化型接著劑層之活性能量線硬化型接著劑組成物中含有之第k 個聚合性單體的溶解度，a_k係表示活性能量線硬化型接著劑組成物中含有之第k個聚合性單體的重量份。Re(550)係表示波長550nm之環狀烯烴系樹脂的保護膜的面內相位差值。δ係表示使用Y-MB法所計算得到之環狀烯烴系樹脂的保護膜之SP值。又，關於用以決定代入各式時的數值之單位，係將S的單位設為g，將Re(550)的單位設為nm，將δ的單位設為(MPa)^1/2]。 Re (550) ≧ -38.37ln ( S ) -434.4 δ + 8063 (1) [In formula (1), S is the solubility of the polymerizable monomer and is expressed by the following formula:

S _k represents the system with respect to water of 100g 25 ℃, hardened and then formed solubility of the active agent layer containing the energy ray curable adhesive composition is the k polymerizable monomers active energy ray, represented by A _k-based activity A weight part of the k-th polymerizable monomer contained in the energy ray-curable adhesive composition. Re (550) is an in-plane retardation value of a protective film of a cyclic olefin-based resin having a wavelength of 550 nm. δ represents the SP value of the protective film of the cyclic olefin-based resin calculated by the Y-MB method. Regarding the unit for determining the numerical value when substituted into each formula, the unit of S is g, the unit of Re (550) is nm, and the unit of δ is (MPa) ^1/2 ].

When a protective film of a cyclic olefin resin is disposed on both sides of the polarizer, among the above-mentioned formula (1), Re (550) is set as the in-plane retardation value of the protective film of a pair of cyclic olefin resins. The smaller the absolute value is the in-plane retardation value of the protective film of the cyclic olefin-based resin.

When a protective film of a cyclic olefin-based resin is disposed on both sides of the polarizer, among the above-mentioned formula (1), δ is the in-plane retardation value of the protective film provided as a pair of cyclic olefin-based resins, and the absolute value is Δ of the protective film of the smaller cyclic olefin-based resin. Although it also depends on the functional group of the cyclic olefin structure, the SP value of the cyclic olefin-based resin is preferably 17 to 19 (MPa) ^1/2 .

In the formula (1), the polymerizable monomer refers to an additive such as a compound that can participate in polymerization by irradiating active energy rays, and an antistatic agent that does not participate in the polymerization reaction, and is not included in the polymerizable monomer. When a radically polymerizable compound is used as the polymerizable monomer, the solubility of the radically polymerizable compound in 100 g of water at 25 ° C. is shown in the following table, for example. By. From the viewpoint of a protective film that can use a wider variety of cyclic olefin-based resins, in formula (1), S is preferably 10 or more, more preferably 50 or more, and 100 or more. In addition, S is usually 1500 or less.

Even if the polymerizable monomer is a hardened active energy ray-curable adhesive layer, the hardened material can be decomposed into monomer units by using a heating fluid, a supercritical fluid, and the like, and liquid chromatography and gas chromatography can be used. Determined after analysis.

[Laminated body manufacturing method 1

The laminated body of the present invention is capable of curing the active energy ray-curable adhesive composition by applying the active energy ray-curable adhesive composition to a polarizing plate and / or a substrate, and bonding the polarizing plate and the substrate to each other. Manufacturing. A liquid crystal panel having a polarizing plate may be bonded to the substrate instead of the polarizing plate.

The shape of the laminated body of the present invention is not particularly limited, and a rectangular shape is preferred. By making the shape of the laminated body rectangular, it is easy to arrange an active energy ray-curable adhesive composition, and a liquid crystal display device having superior visibility can be obtained. Incorporate general laminates such as mobile phones or In the case of a small liquid crystal display device at the input terminal, compared with the case of incorporating a large liquid crystal display device such as a television, because the end area is relatively large to the screen area, solvent cracks occur at the ends of the polarizing plate. At this time, it is easier for the user to perceive the part with reduced visibility. Since the laminated body of the present invention does not cause solvent cracks at the ends of the polarizing plate, even a small liquid crystal display device can be suitably incorporated. When the size of the laminated body included in such a small-sized liquid crystal display device is rectangular, the length of the long side is preferably 5 cm or more, or 10 cm or more, and generally 30 cm or less. The short side length is preferably 3 cm or more, may be 5 cm or more, and is generally 20 cm or less. The term “end portion” refers to a region from the edge of the protective film of the cyclic olefin resin to 5 mm.

As a method for applying an active energy ray-curable adhesive composition on a polarizing plate and / or a substrate, known methods such as die coating, doctor blade coating, and curtain coating can be used.

The active energy ray-curable adhesive composition may be applied to the entire surface of the main surface of the polarizing plate and / or the substrate, or may be applied to a part of the main surface of the polarizing plate and / or the substrate so that an uncoated portion remains. As a comprehensive method for coating the main surface of the polarizing plate and / or the substrate, a method of coating such that the active energy ray-curable adhesive composition is in contact with the ends and side surfaces of the polarizing plate can be mentioned. As a method of applying so that an uncoated portion remains on a part of the main surface of the polarizing plate and / or substrate, for example, a method of leaving an uncoated portion on an end portion of the main surface of the polarizing plate and / or substrate may be mentioned.

After the active energy ray-curable adhesive composition is coated on a polarizing plate and / or a substrate, the polarizing plate and the substrate can be bonded to obtain Fitting. At this time, in order to adjust the thickness of the active energy ray-curable adhesive layer, the distance between the polarizing plate and the substrate may be maintained by a support rod, a spacer, or the like.

The laminated body of the present invention can be obtained by irradiating the adherend with an active energy ray to harden the active energy ray-curable adhesive composition into an active energy ray-curable adhesive layer.

Examples of the active energy ray irradiated to the active energy ray-curable adhesive composition include visible light, ultraviolet rays, X-rays, and electron rays, and ultraviolet rays are particularly preferred. Examples of active energy ray light sources include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, halogen lamps, carbon arc lamps, tungsten lamps, gallium lamps, excimer lasers, and a wavelength range of 380 to 440 nm Luminous LED light source, chemical lamp, black light lamp, microwave excited mercury lamp, metal halide lamp.

The intensity of the active energy ray irradiated to the active energy ray-curable adhesive composition is generally 0.1 to 100 mW / cm ² . When the active energy ray-curable adhesive composition contains a polymerization initiator, the intensity of the active energy ray in a wavelength region effective for activation of the polymerization initiator is preferably set to 0.1 to 100 mW / cm ² . When the intensity of the active energy ray is within the above range, in addition to shortening the reaction time, it is also possible to suppress yellowing of the active energy ray-curable adhesive layer due to radiant heat and reaction heat and deterioration of the protective film of the cyclic olefin resin.

The cumulative amount of light expressed as the product of the intensity of the active energy ray and the irradiation time is preferably set to 10 to 5000 mJ / cm ² . When the cumulative light amount is in the above range, in addition to being able to generate a sufficient amount of active species of the polymerization initiator, the irradiation time of the active energy ray can be shortened and productivity can be improved.

The layer structure of the laminated body of this invention manufactured in this way is demonstrated. FIG. 1 (a) shows a laminated body 100, which is obtained by laminating a polarizing plate 10 and a substrate 1 through an active energy ray-curable adhesive layer 2. The polarizing plate has a ring shape on both sides of a polarizer 4. Protective film 3 of olefin resin. FIG. 1 (b) shows a laminated body 100, which is obtained by laminating a polarizing plate 10 and a substrate 1 through an active energy ray-curable adhesive layer 2. The polarizing plate has a ring shape on one side of a polarizer 4. The protective film 3 of the olefin-based resin has another protective film 5 on the other side. The structure shown in FIG. 1B is laminated so that the main surface of the protective film 3 of the cyclic olefin resin and the main surface of the active energy ray-curable adhesive layer 2 are in contact with each other. Fig. 1 (c) shows the laminated body 100 in the same way as Fig. 1 (b), which is obtained by laminating a polarizing plate 10 and a substrate 1 through an active energy ray-curable adhesive layer 2. The polarizing plate is The polarizer 4 has a protective film 3 of a cyclic olefin resin on one side and another protective film 5 on the other side. The structure shown in FIG. 1 (c) is laminated so that the main surface of the other protective film 5 is in contact with the main surface of the active energy ray-curable adhesive layer 2.

The laminated body of the present invention can be formed by laminating a liquid crystal panel and a substrate through an active energy ray-curable adhesive, wherein the liquid crystal panel is formed by bonding a liquid crystal cell to a polarizing plate through an adhesive. The surface on which the laminated body of the present invention is bonded to a liquid crystal cell is the surface on the opposite side, and is usually a laminated polarizing plate. This polarizing plate can be applied to a conventionally known polarizing plate. In FIG. 2, the liquid crystal panel 20 and the substrate are passed through the active energy ray-curable adhesive layer 2. Laminated body made of 1 layer. The liquid crystal panel 20 has a structure in which a protective film 3 of a cyclic olefin resin is provided on both sides of the polarizer 4, and a polarizing plate 11 having an adhesive with an adhesive 6 and a liquid crystal cell 7 are bonded through an adhesive layer 6. Furthermore, a conventional polarizing plate 8 is bonded to the surface of the liquid crystal cell and the surface of the polarizing plate 11 to which the adhesive is adhered is the opposite surface.

The laminated body of the present invention is formed by suppressing solvent cracking of the polymerizable monomer contained in the adhesive composition, and therefore has excellent visibility and can be suitably incorporated in various liquid crystal display devices.

[Example]

Hereinafter, the present invention will be described with examples, but the present invention is not limited to these examples at all.

[Calculation method of solubility parameter (SP value)]

The SP value of the protective film of a cyclic olefin resin is calculated using the Y-MB method using a software called HSPiP.

[Production of active energy ray-curable adhesive composition]

As described in Table 2 below, polymerizable monomers were mixed to obtain compositions 1 to 12. The solubility S of the polymerizable monomer contained in each composition is obtained in accordance with the following formula and is also described in Table 2.

S_k係表示對25℃的水100g之在形成活性能量線硬化型接著劑層之活性能量線硬化型接著劑組成物所含有之第k個聚合性單體的溶解度，a_k係表示在活性能量線硬化型接著劑組成物所含有之第k個聚合性單體的重量份。

_K represents S based on 100g of water at 25 deg.] C the solubility is formed comprising the active energy ray curable adhesive layer and then the active energy ray curable adhesive composition of polymerizable monomers k, a _k are diagrams activity A weight part of the k-th polymerizable monomer contained in the energy ray-curable adhesive composition.

The abbreviations in Table 2 indicate the following compounds, and the solubility in 100 g of water at 25 ° C is shown in Table 1.

IBOA: isoamyl acrylate

BA: Butyl acrylate

EA: ethyl acrylate

MA: methyl acrylate

2HEA: 2-hydroxyethyl acrylate

[Manufacture of polarizing plate]

The average degree of polymerization is about 2400, the degree of saponification is 99.9 mol% or more, and the thickness The 75 μm polyvinyl alcohol film was stretched about 5 times in a dry uniaxial direction, and kept under tension, immersed in pure water at 60 ° C for 1 minute, and then immersed in 28% of iodine / potassium iodide / water weight ratio of 0.05 / 5/100 aqueous solution for 60 seconds. Subsequently, it was immersed in an aqueous solution of potassium iodide / boric acid / water weight ratio of 8.5 / 8.5 / 100 at 72 ° C. for 300 seconds. Next, it was washed with pure water at 26 ° C for 20 seconds, and then dried at 65 ° C to obtain a polarizing film made of polyvinyl alcohol with iodine adsorption alignment.

3 parts of carboxyl-modified polyvinyl alcohol ["KL-318" obtained from KURARAY Co., Ltd.] was dissolved in 100 parts of water, and 1.5 parts of a water-soluble epoxy resin of polyamine epoxy system was added to the aqueous solution The additive [an aqueous solution with a trade name of "Sumirez Resin (registered trademark) 650 (30)" and a solid content concentration of 30% obtained from Taoka Chemical Industry Co., Ltd.] was used as an aqueous adhesive.

Using the aforementioned water-based adhesive, a protective film of an unstretched cyclic olefin-based resin with a thickness of 23 μm and a phase difference value of 0 nm (manufactured by ZEON Corporation, ZEONOR film (registered trademark), ZF14-023, SP value: 18.0 (MPa) ^1/2 ) was bonded to both surfaces of the polarizing film to obtain a polarizing plate 1. Before bonding, the bonding surface of the protective film of the cyclic olefin resin is subjected to a corona discharge treatment. After the bonding, the polarizing plate 1 was dried at 80 ° C. for 5 minutes and aged at 40 ° C. for 168 hours.

In addition to replacing the protective film of a cyclic olefin resin with a protective film of a horizontal uniaxially stretched cyclic olefin resin with a phase difference of 90 nm and a thickness of 25 μm (manufactured by ZEON Corporation, ZEONOR film (registered trademark)) , ZT12-090079-F1330, SP value: 18.0 (MPa) ^1/2 ), the same procedure as in the polarizing plate 1 was performed to obtain the polarizing plate 2.

In addition to replacing the protective film of a cyclic olefin resin with a protective film of a horizontal uniaxially-extended cyclic olefin resin with a phase difference of 125 nm and a thickness of 20 μm (manufactured by Japan Zeon Corporation, SP value: 18.0 (MPa The polarizing plate 3 was obtained in the same manner as in the polarizing plate 1 except for) ^1/2 ).

In addition to replacing the protective film of a cyclic olefin resin with a protective film of an inclined cyclic olefin resin having a retardation value of 141 nm and a thickness of 23 μm (manufactured by ZEON Corporation, ZEONOR film (registered trademark), ZD12 Other than -141158-A1330, SP value: 18.0 (MPa) ^1/2 ), the same procedure as in the polarizing plate 1 was performed to obtain the polarizing plate 4.

In addition to replacing the protective film of a cyclic olefin resin with a protective film (arton (registered trademark) film, RJT1150, SP value: 17.8 (MPa) The polarizing plate 5 was obtained in the same manner as in the polarizing plate 1 except for) ^1/2 ).

[Evaluation of solvent crack resistance of polarizing plate]

The combination of the polarizing plates and active energy ray-curable adhesive compositions shown in Tables 3 and 4 below was evaluated for solvent crack resistance using the method described below.

The polarizing plate was cut into a square of 10 cm × 10 cm. Permeable pressure-sensitive adhesive sheet (thickness: 25 μ, butyl acrylate as the main component, acrylic copolymer copolymerized with a small amount of 2-hydroxyethyl acrylate and acrylic acid) The enoic resin was blended with an isocyanate-based crosslinking agent and a silane compound), and the cut polarizer was attached to a glass substrate (CORNING, EAGLE XG (registered trademark)) having a thickness of 0.4 mm as a sample for evaluation. Subsequently, in order to remove air bubbles between the glass substrate and the sample for evaluation, an autoclave was used for treatment at 0.5 MPa and 50 ° C. for 20 minutes, and a film was subjected to heat treatment at 105 ° C. for 30 minutes in order to deform the film to the maximum.

An active energy ray-curable adhesive composition was applied onto the main surface of the polarizing plate so that the thickness became 100 μm, and a cover glass was placed thereon. When a cover glass is mounted, the side surface of the polarizing plate is covered with an active energy ray-curable adhesive composition.

After standing at room temperature for 24 hours, it was visually observed whether cracks occurred in the protective film of the cyclic olefin-based resin of the evaluation sample. The determination criteria of the solvent crack evaluation shown in Tables 3 and 4 are as follows.

○: No cracking occurs in the protective film of the cyclic olefin resin.

×: One or more cracks occurred in the protective film of the cyclic olefin resin.

As shown in Tables 3 and 4, the polymerizable monomer contained in the active energy ray-curable adhesive composition is appropriately selected so that the SP value of the protective film of the cyclic olefin resin satisfies the formula (1). In the experimental example of the type of the body, the blending ratio, and the in-plane retardation value of the protective film of the cyclic olefin-based resin, the protective film of the cyclic olefin-based resin constituting the polarizing plate did not cause solvent cracking. Therefore, the laminated body obtained by the combination of the active energy ray-curable adhesive composition and the polarizing plate without generating a solvent crack can obtain a liquid crystal display device which does not generate a solvent crack and has excellent visibility.

[Industrial availability]

According to the present invention, it is useful to provide a laminated body that does not cause solvent cracks in the protective film constituting the polarizing plate, and to provide a liquid crystal display device having excellent visibility incorporating the laminated body.

Claims (6)

A laminated body is a laminated body having a substrate, an active energy ray-curable adhesive layer, and a polarizing plate in order. The polarizing plate is a polarizing plate having a polarizer and a protective film of a cyclic olefin resin, and satisfies the following formula. Re (550) ≧ -38.371n ( S ) -434.4δ + 8063 (1) [In formula (1), S is represented by S _k represents the system with respect to water of 100g 25 ℃, followed by forming the hardened solubility of the active agent contained in the layer of energy ray curable adhesive composition of polymerizable monomers k of active energy ray, represented by line A _k The weight part of the k-th polymerizable monomer, Re (550) represents an in-plane retardation value of a protective film of a cyclic olefin resin having a wavelength of 550 nm, and δ represents the foregoing calculated by the Y-MB method. The SP value of the protective film of the cyclic olefin resin, the unit of S is set to g, the unit of Re (550) is set to nm, and the unit of δ is set to (MPa) ^1/2 ]. The laminated body according to item 1 of the scope of patent application, wherein the active energy ray-curable adhesive layer is a layer covering the main surface and the side surface of the polarizing plate. The laminated body according to item 1 or 2 of the scope of application for a patent, wherein the active energy ray-curable adhesive composition contains a radical polymerizable compound. The laminated body according to item 1 or 2 of the scope of patent application, wherein the protective film of the cyclic olefin resin has an SP value of 17 to 19. The laminated body according to item 1 or 2 of the scope of patent application, wherein the laminated body has a rectangular shape, the length of the long side is 5 cm or more, and the length of the short side is 3 cm or more. A liquid crystal display device includes the laminated body according to any one of claims 1 to 5.