JP6384985B2 - Polarizing plate, functional laminate, liquid crystal display device, and manufacturing method of polarizing plate - Google Patents

Description

  The present invention relates to a polarizing plate having a glycol ester component on a specific surface, a functional laminate including the polarizing plate, and a liquid crystal display device including the functional laminate. The present invention also relates to a method for easily producing the polarizing plate.

  In liquid crystal display devices and organic EL display devices, for example, in liquid crystal display devices, it is indispensable to dispose polarizing elements on both sides of the liquid crystal cell, and in general, polarizing plates are attached. Has been.

  The polarizing plate is obtained by laminating a transparent protective film on at least one surface of a polarizer, and may add value by further laminating a functional film on the transparent protective film via an adhesive layer. . Specifically, for example, a polarizing plate on which a 3D-compatible FPR film (film / pattern / retarder film) or a brightness enhancement film is laminated is known.

  Thus, when laminating | stacking a functional film on a polarizing plate through an adhesive layer, the adhesiveness of a polarizing plate and the said adhesive layer is needed. As a method for improving the adhesion between the polarizing plate and the pressure-sensitive adhesive layer, for example, the surface of the polarizing plate is subjected to a pretreatment such as a saponification treatment or a corona treatment, or a plasma irradiation method (for example, see Patent Document 1). ) Etc. are known.

JP 2003-121646 A

  In recent years, when a polarizing plate is transported, it may be exposed to a humidified environment. When a laminate in which a functional film is laminated on a polarizing plate via an adhesive layer is exposed to a humidified environment, the functional film is Sometimes it peeled off.

  In the method of Patent Document 1, although the adhesiveness between the polarizing plate and the pressure-sensitive adhesive layer laminated on the polarizing plate is improved, the adhesiveness in a humidified environment has not been studied and is not sufficient. .

  Accordingly, an object of the present invention is to provide a polarizing plate that can exhibit high adhesion even in a humidified environment, a functional laminate including the polarizing plate, and a liquid crystal display device including the functional laminate. . Another object of the present invention is to provide a method by which the polarizing plate can be easily produced.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by the polarizing plate shown below, and have completed the present invention.

That is, the present invention includes a polarizing plate, a pressure-sensitive adhesive layer, and a functional film in which a transparent protective film is laminated on at least one surface of a polarizer in this order, and the pressure-sensitive adhesive layer is the transparent protective film of the polarizing plate. A polarizing plate used for the functional laminate laminated on the top,
The present invention relates to a polarizing plate having a glycol ester component on the surface of the transparent protective film in contact with the pressure-sensitive adhesive layer.

（式中、Ｒ^１及びＲ^２は、それぞれ独立して炭素数１〜２０のアルキル基またはアリール基であり、Ｒ^３は、水素またはメチル基を示し、ｎは、２〜２０の整数である）
で示される化合物であることが好ましい。 The glycol ester component is represented by the following formula (1):

(In the formula, R ¹ and R ² are each independently an alkyl group or an aryl group having 1 to 20 carbon atoms, R ³ represents hydrogen or a methyl group, and n is an integer of 2 to 20) )
It is preferable that it is a compound shown by these.

  Moreover, this invention relates to the functional laminated body by which the functional film is laminated | stacked through the adhesive layer on the transparent protective film which has the glycol-type ester component of the said polarizing plate.

  The present invention also relates to a liquid crystal display device comprising at least a liquid crystal cell and the functional laminate.

Furthermore, the present invention provides a step of preparing a polarizing plate in which a transparent protective film is laminated on at least one side of a polarizer,
Forming a transfer sheet having a layer containing a glycol ester component on a substrate;
A step of bonding the polarizing plate and the transfer sheet to form a laminate so that the layer containing the glycol ester component of the transfer sheet is in contact with the transparent protective film of the polarizing plate; and
And a step of peeling the transfer sheet from the laminate.

  Since the polarizing plate of the present invention has a glycol-based ester component on the transparent protective film surface on which the functional film is laminated via the pressure-sensitive adhesive layer, even without forming an easy adhesion treatment layer or the like, even in a humidified environment, High adhesiveness can be expressed with respect to the pressure-sensitive adhesive layer. Therefore, the functional laminate in which the functional film is laminated on the polarizing plate of the present invention via the pressure-sensitive adhesive layer can suppress the functional film from being peeled off in a humidified environment. Further, the present invention provides a very simple method in which a transfer sheet having a layer containing a glycol ester component is bonded to a polarizing plate, and the glycol ester component is transferred onto the polarizing plate, even in a humidified environment. A polarizing plate that can exhibit high adhesion to the pressure-sensitive adhesive layer can be produced.

It is a conceptual diagram which shows the one aspect | mode of the liquid crystal display device of this invention.

1. Polarizing plate The polarizing plate of the present invention comprises a polarizing plate in which a transparent protective film is laminated on at least one surface of a polarizer, an adhesive layer, and a functional film in this order, and the adhesive layer is the same as that of the polarizing plate. A polarizing plate used for a functional laminate laminated on a transparent protective film,
The transparent protective film has a glycol ester component on the surface in contact with the pressure-sensitive adhesive layer.

  In the polarizing plate of the present invention, a transparent protective film serving as a protective layer is appropriately laminated on one side or both sides of a polarizer via an adhesive layer. When the polarizing plate is a single-sided protective polarizing plate having a transparent protective film only on one side of the polarizer, the polarizing plate of the transparent protective film only needs to have a glycol ester component on the surface to which the polarizer is not bonded. However, in the case of a double-sided protective polarizing plate having a transparent protective film on both sides of the polarizer, it is only necessary to have a glycol ester component on the surface of either one of the transparent protective films to which the polarizer is not adhered.

(1) Polarizer The polarizer is not particularly limited, and various types can be used. Examples of the polarizer include hydrophilic polymer films such as polyvinyl alcohol (PVA) resin films, partially formalized PVA resin films, ethylene / vinyl acetate copolymer partially saponified films, iodine and dichroic dyes. And uniaxially stretched by adsorbing a dichroic material such as PVA, and polyene-based oriented films such as PVA dehydrated products and polyvinyl chloride dehydrochlorinated products. Among these, a PVA polarizer comprising a PVA resin film and a dichroic substance such as iodine is preferable.

  As the PVA polarizer, a PVA resin film is dyed with a dichroic substance (typically iodine or a dichroic dye) and uniaxially stretched. The polymerization degree of the PVA resin constituting the PVA resin film is preferably 100 to 10,000, and more preferably 1000 to 5,000. If the degree of polymerization is too low, the film tends to be stretched when performing predetermined stretching, and if the degree of polymerization is too high, tension may be abnormally required for stretching, and mechanical stretching may not be possible. Moreover, it is preferable that the average saponification degree of PVA resin is about 85-100 mol%, and it is more preferable that it is 90-100 mol%.

  The PVA-based resin film constituting the polarizer can be formed by any appropriate method (for example, a casting method in which a solution obtained by dissolving a resin in water or an organic solvent is cast, a casting method, an extrusion method). it can. The thickness of the PVA-based resin film is usually about 10 to 300 μm, and preferably about 30 to 75 μm.

  As a manufacturing method of the polarizer, any appropriate method is adopted depending on the purpose, material used, conditions, and the like. For example, the system which uses the said PVA-type resin film for a series of manufacturing processes including a swelling, dyeing | staining, bridge | crosslinking, extending | stretching, water washing, and a drying process is employ | adopted normally. In each processing step excluding the drying step, the treatment can be performed by immersing the PVA resin film in a liquid containing the solution used in each step. The order, number of times, and presence / absence of each treatment of swelling, dyeing, crosslinking, stretching, washing with water, and drying can be appropriately set according to the purpose, materials used, conditions, and the like. For example, several processes may be performed simultaneously in one step, and a swelling process, a dyeing process, and a crosslinking process may be performed simultaneously. In addition, for example, it is possible to appropriately employ the crosslinking treatment before and after the stretching treatment. For example, the water washing process may be performed after all the processes, or may be performed only after a specific process.

  The thickness of the polarizer is not particularly limited, but is preferably about 1 to 35 μm, and more preferably about 15 to 35 μm. When the thickness of the polarizer is too thin, there is a tendency to be easily damaged when bonded to the transparent protective film. On the other hand, if the thickness of the polarizer is too thick, the drying efficiency tends to deteriorate, which is not preferable in terms of productivity.

(2) Transparent protective film As the transparent protective film, various types can be used. Moreover, when providing a transparent protective film on both surfaces of a polarizer, the same transparent protective film may be sufficient and a different transparent protective film may be sufficient.

  Examples of the material constituting the transparent protective film include thermoplastic resins that are excellent in transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, and the like. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose (TAC), polyester resins such as polyethylene terephthalate (PET), polyethersulfone resins, polysulfone resins, polycarbonate resins, and polyamides. Resin, polyimide resin, polyolefin resin, cycloolefin resin, (meth) acrylic resin, polyarylate resin, polystyrene resin, PVA resin, and mixtures thereof. Further, thermosetting resins such as (meth) acrylic resins, urethane resins, acrylic urethane resins, epoxy resins, and silicone resins, or ultraviolet curable resins may be used. Among these, a cellulose resin and a (meth) acrylic resin are preferable.

  A commercially available product can also be used as the film containing the cellulose resin. Examples of commercially available triacetyl cellulose films include trade names “UV-50”, “UV-80”, “SH-80”, “TD-80U”, and “TD-TAC” manufactured by FUJIFILM Corporation. , “TD-60UL”, “UZ-TAC”, “KC series” manufactured by Konica Minolta, and the like.

  Any appropriate (meth) acrylic resin can be adopted as the (meth) acrylic resin within a range not impairing the effects of the present invention. For example, poly (meth) acrylic acid ester such as polymethyl methacrylate, methyl methacrylate- (meth) acrylic acid copolymer, methyl methacrylate- (meth) acrylic acid ester copolymer, methyl methacrylate-acrylic acid ester- (Meth) acrylic acid copolymer, (meth) methyl acrylate-styrene copolymer (MS resin, etc.), a polymer having an alicyclic hydrocarbon group (for example, methyl methacrylate-cyclohexyl methacrylate copolymer, Methyl methacrylate- (meth) acrylate norbornyl copolymer, etc.). Among these, poly (meth) acrylic acid ester obtained by polymerizing (meth) acrylic acid ester having an alkyl group having 1 to 6 carbon atoms can be mentioned.

  Specific examples of the (meth) acrylic resin include, for example, “Acrypet VH”, “Acrypet VRL20A” manufactured by Mitsubishi Rayon Co., Ltd., and a ring structure in the molecule described in JP-A-2004-70296 ( Examples thereof include a (meth) acrylic resin and a high Tg (meth) acrylic resin obtained by intramolecular crosslinking or intramolecular cyclization reaction.

  As the (meth) acrylic resin, a (meth) acrylic resin having a lactone ring structure can also be used. It is because it has high mechanical strength by high heat resistance, high transparency, and biaxial stretching. Examples of the (meth) acrylic resin having a lactone ring structure include JP 2000-230016, JP 2001-151814, JP 2002-120326, JP 2002-254544, and JP 2005. Examples thereof include (meth) acrylic resins having a lactone ring structure described in Japanese Patent No. 146084.

  As the (meth) acrylic resin, an acrylic resin having a structural unit of unsaturated carboxylic acid alkyl ester and a structural unit of glutaric anhydride can be used. Examples of the acrylic resin include Japanese Patent Application Laid-Open Nos. 2004-70290, 2004-70296, 2004-163924, 2004-292812, 2005-314534, and 2006. Examples described in JP-A-131898, JP-A-2006-206881, JP-A-2006-265532, JP-A-2006-283013, JP-A-2006-299005, JP-A-2006-335902, and the like. It is done.

  Moreover, as a (meth) acrylic-type resin, the thermoplastic resin which has a glutarimide unit, a (meth) acrylic acid ester unit, and an aromatic vinyl unit can be used. Examples of the thermoplastic resin include JP 2006-309033 A, JP 2006-317560 A, JP 2006-328329 A, JP 2006-328334 A, JP 2006-337491 A, and JP 2006. -337374, JP 2006-337493 A, JP 2006-337569 A, and the like.

  Furthermore, as the (meth) acrylic resin, an acrylic resin having an N-substituted maleimide unit or a structural unit of maleic anhydride can be used.

  Among them, an acrylic resin group having a ring structure in the main chain is preferable, and the ring structure is selected from a lactone ring structure, a glutaric anhydride structure, a glutarimide structure, an N-substituted maleimide structure, and a maleic anhydride structure. An acrylic resin that is at least one kind is more preferable.

  The thickness of the transparent protective film is not particularly limited, but is generally about 1 to 500 μm and 10 to 300 μm from the viewpoint of workability such as strength and handleability, and thin layer properties. Preferably, it is 20-200 micrometers, It is more preferable that it is 30-100 micrometers.

  Further, as the transparent protective film, a retardation plate having a retardation with a front retardation of 40 nm or more and / or a thickness direction retardation of 80 nm or more can be used. The front phase difference is usually controlled in the range of 40 to 200 nm, and the thickness direction phase difference is usually controlled in the range of 80 to 300 nm. When a retardation plate is used as the transparent protective film, the retardation plate functions also as a transparent protective film, so that the thickness can be reduced.

  Examples of the retardation plate include a birefringent film formed by uniaxially or biaxially stretching a polymer material, a liquid crystal polymer alignment film, and a liquid crystal polymer alignment layer supported by a film. The thickness of the retardation plate is not particularly limited, but is generally about 20 to 150 μm.

  In addition, the film which has the said phase difference can be separately bonded to the transparent protective film which does not have a phase difference, and the said function can also be provided.

  Further, the surface of the transparent protective film to which the polarizer is not adhered may be subjected to a hard coat treatment, an antireflection treatment, an antisticking treatment, a brightness enhancement treatment, a treatment for diffusion or antiglare, and these treatment layers. Can be provided as an optical layer separately from the transparent protective film. However, the polarizing plate of the present invention preferably does not have these layers from the viewpoint of thinning.

(3) Adhesive The adhesive used for laminating the polarizer and the transparent protective film is not particularly limited as long as it is optically transparent, and water-based, solvent-based, hot-melt-based, and radical-curable types. However, water-based adhesives and radical curable adhesives are suitable.

  Examples of aqueous adhesives include PVA adhesives, gelatin adhesives, vinyl latex adhesives, polyurethane adhesives, isocyanate adhesives, polyester adhesives, and epoxy adhesives. The adhesive may contain various crosslinking agents. In addition, a stabilizer such as a catalyst, a coupling agent, various tackifiers, an ultraviolet absorber, an antioxidant, a heat stabilizer, and a hydrolysis stabilizer can be added to the adhesive. The solid content of the adhesive is generally 0.1 to 20% by weight.

  PVA-based resin is a PVA obtained by saponifying polyvinyl acetate; a derivative thereof; a saponified product of a copolymer with vinyl acetate and a copolymerizable monomer; acetalization, urethanization, ether of PVA Modified PVA that has been modified, grafted, or phosphorylated. Examples of the monomer include unsaturated carboxylic acids such as (anhydrous) maleic acid, fumaric acid, crotonic acid, itaconic acid, (meth) acrylic acid, and esters thereof; α-olefins such as ethylene and propylene, (meth) Examples include allyl sulfonic acid (soda), sulfonic acid soda (monoalkyl malate), disulfonic acid soda alkyl maleate, N-methylol acrylamide, acrylamide alkyl sulfonic acid alkali salt, N-vinyl pyrrolidone, N-vinyl pyrrolidone derivatives, and the like. . These PVA resins can be used alone or in combination of two or more.

  The average degree of polymerization of the PVA-based resin is not particularly limited, but is preferably about 100 to 3000, and more preferably about 500 to 3000 from the viewpoint of adhesiveness. Moreover, it is preferable that an average saponification degree is about 85-100 mol%, and it is more preferable that it is 90-100 mol%.

  Moreover, PVA resin which has an acetoacetyl group can be used as PVA-type resin. A PVA resin having an acetoacetyl group is a PVA adhesive having a highly reactive functional group, and is preferable because durability of the polarizing plate is improved.

  The degree of acetoacetyl modification of the PVA resin containing an acetoacetyl group is not particularly limited as long as it is 0.1 mol% or more. If it is less than 0.1 mol%, the water resistance of the adhesive layer tends to be insufficient. The degree of acetoacetyl group modification is preferably about 0.1 to 40 mol%, more preferably 1 to 20 mol%, and even more preferably 2 to 7 mol%. If the degree of acetoacetyl modification exceeds 40 mol%, the effect of improving water resistance tends to be small. The degree of acetoacetyl group modification can be measured by a nuclear magnetic resonance (NMR) device.

  As a crosslinking agent, what is used for the PVA-type adhesive agent can be especially used without a restriction | limiting. As the crosslinking agent, a compound having at least two functional groups having reactivity with the PVA resin can be used. For example, alkylenediamines having two amino groups such as ethylenediamine, triethylenediamine, hexamethylenediamine, and the like; Such as diisocyanate, hydrogenated tolylene diisocyanate, trimethylolpropane tolylene diisocyanate adduct, triphenylmethane triisocyanate, methylenebis (4-phenylmethane) triisocyanate, isophorone diisocyanate, and their ketoxime block or phenol block Isocyanates; ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin di (or tri) glycidyl ether, 1,6- Epoxys such as xanthdiol diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl aniline, diglycidyl amine; monoaldehydes such as formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde; glyoxal, malondialdehyde, succindialdehyde, Dialdehydes such as glutardialdehyde, maleindialdehyde, phthaldialdehyde; amino-formaldehyde resins such as methylol urea, methylol melamine, alkylated methylol urea, alkylated methylolated melamine, acetoguanamine, condensates of benzoguanamine and formaldehyde Further divalent metals such as sodium, potassium, magnesium, calcium, aluminum, iron, nickel, or trivalent Salts and oxides of the genus and the like. Among these, melamine-based crosslinking agents are preferable, and methylol melamine is more preferable.

  The amount of the crosslinking agent is preferably about 0.1 to 60 parts by weight and more preferably 10 to 55 parts by weight with respect to 100 parts by weight of the PVA resin. In particular, when a PVA-based resin containing an acetoacetyl group is used, the crosslinking agent is preferably used in an amount of more than 30 parts by weight, and more preferably in a range of more than 30 parts by weight and 55 parts by weight or less. From the viewpoint of

  Examples of the radical curable adhesive include an active energy ray curable type such as an electron beam curable type and an ultraviolet ray curable type, and a thermosetting type, but an active energy ray curable type that can be cured in a short time. Is preferable, and an ultraviolet curable adhesive is more preferable.

  Examples of the curable component of the radical curable adhesive include a compound having a (meth) acryloyl group and a compound having a vinyl group. These curable components may be monofunctional or bifunctional or higher. Moreover, these curable components can be used individually by 1 type or in combination of 2 or more types. As these curable components, compounds having a (meth) acryloyl group are preferred.

  Specific examples of the compound having a (meth) acryloyl group include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, 2-methyl-2- Nitropropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, t-pentyl (meta ) Acrylate, 3-pentyl (meth) acrylate, 2,2-dimethylbutyl (meth) acrylate, n-hexyl (meth) acrylate, cetyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) Acrylate, 4-methyl-2 Propyl pentyl (meth) acrylate, n- octadecyl (meth) (meth) acrylic acid (20 carbon atoms) acrylate such as alkyl esters.

  Examples of the compound having a (meth) acryloyl group include cycloalkyl (meth) acrylate (for example, cyclohexyl (meth) acrylate, cyclopentyl (meth) acrylate, etc.), aralkyl (meth) acrylate (for example, benzyl (meth) Acrylates), polycyclic (meth) acrylates (for example, 2-isobornyl (meth) acrylate, 2-norbornylmethyl (meth) acrylate, 5-norbornen-2-yl-methyl (meth) acrylate, 3-methyl -2-norbornylmethyl (meth) acrylate, etc.), hydroxyl group-containing (meth) acrylic acid esters (for example, hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2,3-dihydroxypropylmethyl) -Buchi (Meth) methacrylate), alkoxy group or phenoxy group-containing (meth) acrylic acid esters (2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-methoxymethoxyethyl (meth) acrylate, 3 -Methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, etc.), epoxy group-containing (meth) acrylic acid esters (for example, glycidyl (meth) acrylate etc.), halogen-containing (meta ) Acrylic acid esters (for example, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, hexafluoropropyl (meth)) Acryle DOO, octafluoropentyl (meth) acrylate, heptadecafluorodecyl (meth) acrylate), alkylaminoalkyl (meth) acrylates (e.g., dimethylaminoethyl (meth) acrylate etc.) and the like.

  Examples of the compound having a (meth) acryloyl group other than the above include amide group-containing monomers such as hydroxyethyl acrylamide, N-methylol acrylamide, N-methoxymethyl acrylamide, N-ethoxymethyl acrylamide, (meth) acrylamide, and the like. It is done. Moreover, nitrogen-containing monomers, such as acryloyl morpholine, etc. are mentioned.

  Examples of the curable component of the radical curable adhesive include a compound having a plurality of polymerizable double bonds such as a (meth) acryloyl group and a vinyl group, and the compound is bonded as a crosslinking component. It can also be mixed with the agent component. Examples of the curable component that becomes such a crosslinking component include tripropylene glycol diacrylate, 1,9-nonanediol diacrylate, tricyclodecane dimethanol diacrylate, cyclic trimethylolpropane formal acrylate, dioxane glycol diacrylate, and EO. Modified diglycerin tetraacrylate, Aronix M-220 (manufactured by Toagosei Co., Ltd.), light acrylate 1,9ND-A (manufactured by Kyoeisha Chemical Co., Ltd.), light acrylate DGE-4A (manufactured by Kyoeisha Chemical Co., Ltd.), light Examples thereof include acrylate DCP-A (manufactured by Kyoeisha Chemical Co., Ltd.), SR-531 (manufactured by Sartomer), CD-536 (manufactured by Sartomer) and the like. Moreover, various epoxy (meth) acrylates, urethane (meth) acrylates, polyester (meth) acrylates, various (meth) acrylate monomers, and the like are included as necessary.

  The radical curable adhesive contains the curable component, and in addition to the component, a radical polymerization initiator is added according to the type of curing. When the adhesive is used as an electron beam curable type, it is not particularly necessary that the adhesive contains a radical polymerization initiator, but when it is used as an ultraviolet curable type or a thermosetting type, radical polymerization is started. An agent is used. The usage-amount of a radical polymerization initiator is about 0.1-10 weight part normally per 100 weight part of sclerosing | hardenable components, and it is preferable that it is 0.5-3 weight part. In addition, a photosensitizer capable of increasing the curing speed and sensitivity of the electron beam represented by a carbonyl compound or the like can be added to the radical curable adhesive as necessary. The usage-amount of a photosensitizer is about 0.001-10 weight part normally per 100 weight part of sclerosing | hardenable components, and it is preferable that it is 0.01-3 weight part.

  Among the adhesives, a PVA adhesive containing a PVA resin and a crosslinking agent and an ultraviolet curable adhesive are preferable.

  The adhesive further includes a coupling agent such as a silane coupling agent and a titanium coupling agent, various tackifiers, an ultraviolet absorber, an antioxidant, a heat stabilizer, a stabilizer such as a hydrolysis stabilizer, and the like. Can also be blended.

  The adhesive may contain a metal compound filler. The fluidity of the adhesive can be controlled by the metal compound filler, and a polarizing plate having a good appearance with a stable film thickness and uniform adhesion within the surface can be obtained.

  Various types of metal compound fillers can be used. Examples of the metal compound include metal oxides such as alumina, silica, zirconia, titania, aluminum silicate, calcium carbonate and magnesium silicate; metal salts such as zinc carbonate, barium carbonate and calcium phosphate; celite, talc, clay and kaolin And the like. Further, these metal compound fillers may be those having a surface modified.

  The average particle size of the metal compound filler is preferably about 1 to 1000 nm, more preferably about 1 to 500 nm, still more preferably about 10 to 200 nm, and particularly preferably 10 to 100 nm. . If the average particle diameter of the metal compound filler is within the above range, the metal compound can be dispersed substantially uniformly in the adhesive layer, ensuring adhesion, and having a good appearance and in-plane uniform adhesion. You can get sex.

  The compounding amount of the metal compound filler is preferably 100 parts by weight or less, more preferably 1 to 100 parts by weight, further preferably 2 to 50 parts by weight, and 5 to 50 parts by weight with respect to 100 parts by weight of the curable resin component. Particularly preferred. In addition, by setting the blending ratio of the metal compound filler in the above range, in-plane uniform adhesiveness can be obtained with a good appearance while ensuring the adhesiveness between the polarizer and the transparent protective film. When the blending ratio of the metal compound filler exceeds 100 parts by weight, the ratio of the curable resin component in the adhesive is decreased, which is not preferable from the viewpoint of adhesiveness.

  Application | coating of the said adhesive agent may be performed to whichever side of the said polarizer and a transparent protective film, and may be performed to both. The application operation is not particularly limited, and various means such as a roll method, a spray method, and an immersion method can be employed.

  Moreover, you may provide an undercoat layer, an easily bonding process layer, etc. between the said adhesive bond layer, a transparent protective film, or a polarizer.

  The thickness of the adhesive layer formed by the adhesive or the like is not particularly limited, but when the adhesive layer is formed by an aqueous adhesive or the like, the thickness of the adhesive layer is 10 to 300 nm. It is preferable that it is a grade. The thickness of the adhesive layer is more preferably from 10 to 200 nm, and even more preferably from 20 to 150 nm, from the viewpoint of obtaining a uniform in-plane thickness and sufficient adhesive strength. Further, as described above, the thickness of the adhesive layer is preferably designed so as to be larger than the average particle diameter of the metal compound colloid contained in the aqueous adhesive. On the other hand, when the adhesive layer is formed of a curable adhesive, the thickness of the adhesive layer is preferably 0.1 to 20 μm, more preferably 0.2 to 10 μm, and 0 It is particularly preferably 3 to 8 μm.

  After applying the adhesive, the polarizer and the transparent protective film are bonded together with a roll laminator or the like. Then, it dries and forms an adhesive bond layer. When using an aqueous adhesive, the drying is performed at a temperature of about 20 to 80 ° C, preferably 40 to 80 ° C, and preferably performed for about 1 to 10 minutes.

(4) Glycol ester component As described above, the polarizing plate of the present invention is a glycol ester on the surface of the transparent protective film on which the functional film is laminated via the pressure-sensitive adhesive layer (that is, the surface in contact with the pressure-sensitive adhesive layer). It has ingredients.

  The glycol-based ester component only needs to be present on a part or all of the surface of the transparent protective film on which the pressure-sensitive adhesive layer is laminated, and the presence form is not particularly limited. That is, it may exist uniformly on the surface of the transparent protective film on which the pressure-sensitive adhesive layer is laminated, or may be unevenly distributed. Further, it may exist as a layer containing a glycol ester component.

  The abundance of the glycol ester component on the surface of the transparent protective film on which the pressure-sensitive adhesive layer is laminated can be measured by elemental analysis on the surface of the transparent protective film. The amount of the glycol ester component present on the surface of the transparent protective film is preferably 5 atomic% or more, and preferably 5 to 50 atomic%. If the amount of the glycol ester component is less than 5 atomic%, the adhesion to the pressure-sensitive adhesive layer may not be sufficient.

（式中、Ｒ^１及びＲ^２は、それぞれ独立して炭素数１〜２０のアルキル基またはアリール基であり、Ｒ^３は、水素またはメチル基を示し、ｎは、２〜２０の整数である）
で示される化合物であることが好ましい。 The glycol ester component is obtained, for example, by a reaction between a polyalkylene glycol such as triethylene glycol, tetraethylene glycol, or tripropylene glycol and an organic acid. In the present invention, the glycol ester component includes the following formula (1):

(In the formula, R ¹ and R ² are each independently an alkyl group or an aryl group having 1 to 20 carbon atoms, R ³ represents hydrogen or a methyl group, and n is an integer of 2 to 20) )
It is preferable that it is a compound shown by these.

  Examples of the compound represented by the general formula (1) include diethylene glycol di-2-ethylhexanoate, tetraethylene glycol di-2-ethylhexanoate, polyethylene glycol di-2-ethylhexanoate, and triethylene. Glycol diethyl butyrate, polyethylene glycol diethyl butyrate, polypropylene glycol diethyl hexanoate, triethylene glycol dibenzoate, polyethylene glycol dibenzoate, polypropylene glycol dibenzoate, polyethylene glycol-2-ethylhexanoate benzoate In the present invention, these can be used alone or in combination.

  Since the polarizing plate of the present invention has the glycol ester component on the surface of the transparent protective film on which the functional film is laminated via the pressure-sensitive adhesive layer, it is not necessary to separately form an easy adhesion treatment layer or the like in a humidified environment. Can exhibit high adhesive strength.

2. Functional laminate The functional laminate of the present invention is characterized in that a functional film is laminated on the transparent protective film having the glycol ester component of the polarizing plate via an adhesive layer. is there. Here, “the functional film is laminated on the transparent protective film via the pressure-sensitive adhesive layer” means that the surface of the transparent protective film on which the polarizer is not adhered is in contact with the pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer is laminated, and further, a functional film is laminated on the side of the pressure-sensitive adhesive layer that is not in contact with the transparent protective film.

  About the said polarizing plate, the above-mentioned thing can be used.

  The functional film is not particularly limited, and a commonly used film can be used. For example, a retardation film, a hard coat film, an antireflection film, an FPR (Film Patterned Retarder) film, a luminance An improvement film, a UV cut film, etc. can be mentioned.

  The pressure-sensitive adhesive layer is not particularly limited and is preferably formed from a pressure-sensitive adhesive composition containing a base polymer and a crosslinking agent, for example. The pressure-sensitive adhesive composition can be an acrylic, synthetic rubber-based, rubber-based, or silicone-based pressure-sensitive adhesive, but from the viewpoint of transparency, heat resistance, etc., a (meth) acrylic polymer is a base polymer. An acrylic pressure-sensitive adhesive is preferred. A conventionally well-known thing can be used as an acrylic adhesive. In addition, for example, as the (meth) acrylic polymer and the cross-linking agent, those described in the pressure-sensitive adhesive composition containing a glycol-based ester component described later can be used, and the blending ratio is also within the range described later. It can be adopted as appropriate.

  Although it does not specifically limit as thickness of the said adhesive layer, For example, it is preferable that it is 1-50 micrometers, and it is more preferable that it is 5-30 micrometers.

  Although the functional laminated body of this invention is demonstrated referring FIG. 1, it is not limited to the structure of FIG. For example, in the functional laminate 7 of the present invention, the functional film 6 is laminated on the transparent protective film 2 of the viewing side polarizing plate 1 via the pressure-sensitive adhesive layer 5.

3. Liquid crystal display device The liquid crystal display device of the present invention comprises at least a liquid crystal cell and the functional laminate of the present invention.

  An example of the liquid crystal display device of the present invention will be described with reference to FIG. 1, but is not limited to the configuration of FIG. For example, the liquid crystal display device 14 of the present invention includes the functional laminate 7, the liquid crystal cell 8, the back side polarizing plate 9, and the backlight 13. Moreover, the functional laminated body 7 contains the visual recognition side polarizing plate 1, the adhesive layer 5, and the functional film 6 as above-mentioned.

  The viewing side polarizing plate 1 is disposed on the viewing side of the liquid crystal cell 8, and the back side polarizing plate 9 is disposed on the other surface of the liquid crystal cell 8. Further, the viewing side polarizing plate 1 and the back side polarizing plate 9 can be disposed in the liquid crystal cell 8 through an adhesive layer (not shown).

  The viewing side polarizing plate 1 and the back side polarizing plate 9 are both transparent protective films (2, 4, 10,...) Via adhesive layers (not shown) on both sides of the polarizer (3, 11). 12) are pasted together.

  The liquid crystal display device 14 of the present invention is characterized by using the functional laminate 7. Moreover, although the surface which contacts the adhesive layer of the transparent protective film in the polarizing plate of this invention has a glycol-type ester component, the said "surface which contacts the adhesive layer of a transparent protective film" is A in FIG. It is the surface shown by. Since the polarizing plate of the present invention has a glycol ester component on the surface indicated by A, the pressure-sensitive adhesive layer 5 and the viewing-side polarizing plate 1 can be bonded together with high adhesion, and even in a humid environment. It can suppress that the film 6 peels from the visual recognition side polarizing plate 1. FIG.

  Other liquid crystal display device members other than the functional laminate 7 of the present invention, such as the back-side polarizing plate 9, the liquid crystal cell 8, and the backlight 13, and adhesives, pressure-sensitive adhesives, etc. used for bonding them. A conventionally well-known thing can be used. In addition to the above, the liquid crystal display device of the present invention can further include, for example, appropriate components such as a diffusion sheet and a protective plate in one or more layers at appropriate positions. As the liquid crystal cell, any appropriate one can be adopted. For example, an arbitrary type such as a TN type, STN type, or π type can be used.

4). Manufacturing method of polarizing plate The manufacturing method of the polarizing plate of the present invention includes a step of preparing a polarizing plate in which a transparent protective film is laminated on at least one side of a polarizer, a transfer sheet having a layer containing a glycol ester component on a substrate. Forming a laminate by bonding the polarizing plate and the transfer sheet so that the layer containing the glycol ester component of the transfer sheet and the transparent protective film of the polarizing plate are in contact with each other, and And a step of peeling the transfer sheet from the laminate.

(1) Process of preparing a polarizing plate The process of preparing the polarizing plate by which the transparent protective film was laminated | stacked on the at least single side | surface of the polarizer is as above-mentioned.

(2) Step of forming transfer sheet The transfer sheet used in the production method of the present invention has a layer containing a glycol ester component on a substrate. The glycol ester component is as described above.

  Although it does not specifically limit as said base material, For example, the sheet | seat or paper which consists of polyester resins, such as a polyethylene terephthalate (PET) and a polybutylene terephthalate (PBT), polyolefin, polyamide, a polycarbonate, an acrylic resin, polyvinyl chloride, etc. And the like. Among these, a PET film is preferable. In addition, these base materials are within the range that does not affect the effect of the present invention, other additives such as pigments, dyes, antioxidants, deterioration inhibitors, fillers, ultraviolet absorbers, antistatic agents, And / or the electromagnetic wave inhibitor may be included.

  Although the thickness of a base material is not specifically limited, It is preferable that it is about 10-50 micrometers. In addition, the base material may be subjected to an easy adhesion treatment such as a corona treatment, a plasma treatment, or a blast treatment, if necessary.

  The thickness of the layer containing the glycol ester component on the substrate is, for example, preferably about 1 to 200 μm, more preferably 3 to 100 μm, and still more preferably 5 to 50 μm.

  Although it does not specifically limit as a formation method of the layer containing the said glycol type ester component, For example, the adhesive composition containing a glycol type ester component can be apply | coated and formed on a base material. A known method can be applied as the coating method, and examples thereof include a roller coating method, a brush coating method, a spray coating method, a die coater, a bar coater, and a knife coater. And said application layer can be normally dried and bridge | crosslinked by heating conditions at 60-120 degreeC and about 0.5 to 3 minutes with a hot air dryer, and a transfer sheet can be obtained.

  Also, a release sheet can be laminated on the surface of the transfer sheet containing the glycol ester component for convenience of handling. As such a releasable sheet, a known sheet can be used. For example, a sheet obtained by applying a silicone-based release agent to the surface of a plastic sheet can be used. In some cases, a film with low adhesiveness such as a polyolefin-based film can be used untreated.

  Although it does not specifically limit as an adhesive composition containing the said glycol-type ester component, For example, the adhesive composition containing an acrylic polymer, the said glycol-type ester component, and a crosslinking agent can be mentioned.

  The acrylic polymer is a polymer obtained by polymerizing a monomer component mainly composed of (meth) acrylic acid ester. Here, a main component means that it is 70 weight% or more in all the monomer components which comprise an acryl-type polymer, and it is preferable that 90 weight% or more is contained. In addition, (meth) acrylic acid ester means acrylic acid ester and / or methacrylic acid ester, and (meth) of the present invention has the same meaning.

  Although it does not specifically limit as (meth) acrylic acid ester, For example, (meth) acrylic acid methyl, (meth) acrylic acid ethyl, (meth) acrylic acid n-butyl, (meth) acrylic acid i- Butyl, n-octyl (meth) acrylate, i-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, i-nonyl (meth) acrylate, (meth) Examples include (meth) acrylic acid esters having a linear or branched alkyl group having 1 to 18 carbon atoms such as n-decyl acrylate, n-dodecyl (meth) acrylate, and stearyl (meth) acrylate. These can be used individually by 1 type or in mixture of 2 or more types.

  The monomer component forming the (meth) acrylic polymer can contain a hydroxyl group-containing monomer, and the content thereof is preferably about 0.1 to 10% by weight in the monomer component, and 1 to 8 More preferably, it is 3% by weight, and still more preferably 3-7% by weight.

  The type of the hydroxyl group-containing monomer is not particularly limited as long as it is a monomer containing a hydroxyl group, and examples thereof include (meth) acrylic acid ester containing a hydroxyl group and other monomers. Examples of the (meth) acrylic acid ester containing a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth). Acrylate, 3-methyl-3-hydroxybutyl (meth) acrylate, 1,1-dimethyl-3-hydroxybutyl (meth) acrylate, 1,3-dimethyl-3-hydroxybutyl (meth) acrylate, 2,2,4 -Trimethyl-3-hydroxypentyl (meth) acrylate, 2-ethyl-3-hydroxyhexyl (meth) acrylate, glycerin mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate Poly (ethylene glycol - propylene glycol) mono (meth) acrylate, and N- methylol acrylamide. Examples of other monomers include allyl alcohol and methallyl alcohol. Among these, 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are preferable.

  The monomer component may contain a copolymerization monomer in addition to the (meth) acrylic acid ester and the hydroxyl group-containing monomer. Examples of the copolymerization monomer include saturated fatty acid vinyl esters such as vinyl formate, vinyl acetate, vinyl propionate, and “vinyl versatate” (trade name); aromatic vinyl units such as styrene, α-methylstyrene, and vinyltoluene. Bodies; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; dimethyl malate, di-N-butyl malate, di-2-ethylhexyl malate, di-N-octyl malate, dimethyl fumarate, di-N- Mention may be made of maleic acid or fumaric acid diesters such as butyl fumarate, di-2-ethylhexyl fumarate and di-N-octyl fumarate.

  Furthermore, as a monomer that can be contained in the monomer component, a monomer having at least one functional group in addition to one radical polymerizable unsaturated group in the molecule, and a monomer other than the hydroxyl group-containing monomer , If necessary.

  Examples of the monomer include monomers having a functional group such as a carboxyl group, an amide group or a substituted amide group, an amino group or a substituted amino group, a lower alkoxyl group, or an epoxy group. A monomer having two or more radically polymerizable unsaturated groups can also be used.

  The carboxyl group-containing monomer is not particularly limited as long as it is a monomer having a carboxyl group. For example, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, itaconic acid, citracone Acid, cinnamic acid, succinic acid monohydroxyethyl (meth) acrylate, maleic acid monohydroxyethyl (meth) acrylate, fumarate monohydroxyethyl (meth) acrylate, phthalic acid monohydroxyethyl (meth) acrylate, 1,2-di Examples thereof include carboxycyclohexane monohydroxyethyl (meth) acrylate, (meth) acrylic acid dimer, ω-carboxy-polycaprolactone mono (meth) acrylate and the like.

  Specific examples of the monomer having an amide group or a substituted amide group, an amino group or a substituted amino group as the above functional group include, for example, acrylamide, methacrylamide, diacetone acrylamide, N-methylol acrylamide, N-methylol methacrylamide, N Amide group or substituted amide group-containing monomers such as butoxymethylacrylamide, Ni-butoxymethylacrylamide, N, N-dimethylacrylamide, N-methylacrylamide (preferably acrylamide, methacrylamide); Acrylate, N, N-dimethylaminoethyl acrylate, N, N-diethylaminoethyl acrylate, N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, etc. And an amino group or substituted amino group-containing monomer.

  Examples of the monomer having a lower alkoxyl group or an epoxy group as the functional group include 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-n-butoxyethyl (meth) acrylate, and 2-methoxy. Lower alkoxyl group-containing monomers such as ethoxyethyl (meth) acrylate, 2-ethoxyethoxyethyl (meth) acrylate, 2-N-butoxyethoxyethyl (meth) acrylate, methoxypolyethylene glycol mono (meth) acrylate; glycidyl (meta ) Epoxy group-containing monomers such as acrylate, glycidyl allyl ether, glycidyl methallyl ether and the like can be mentioned.

  Examples of the monomer having two or more radically polymerizable unsaturated groups in the molecule include divinylbenzene, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, ethylene glycol di (meth) acrylate, 1,2-propylene. Glycol di (meth) acrylate, 1,3-propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) Mention may be made of monomers having two or more radically polymerizable unsaturated groups such as acrylate, trimethylolpropane tri (meth) acrylate and allyl (meth) acrylate.

  The content of the monomer other than the (meth) acrylic acid ester and the hydroxyl group-containing monomer is not particularly limited and can be appropriately added within a range not impairing the effects of the present invention. For example, in the monomer component It is preferably about 10% by weight or less, more preferably about 7% by weight or less, and further preferably about 5% by weight or less.

  The glass transition point (Tg) of the acrylic polymer is preferably −60 to −40 ° C. The weight average molecular weight (Mw) of the acrylic polymer is preferably 300,000 or more, more preferably 350,000 or more, and further preferably 400,000 to 1,000,000. Moreover, the ratio Mw / Mn of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the acrylic polymer is preferably 15 or less, and more preferably 12 or less. In addition, the value measured by the gel permeation chromatography (GPC) method according to the usual method is used for the value of the said weight average molecular weight (Mw) and number average molecular weight (Mn) in this specification.

  The polymerization method of the acrylic polymer used in the present invention is not particularly limited, and polymerization can be performed by a known method such as solution polymerization, emulsion polymerization, suspension polymerization, etc. Among them, solution polymerization is preferable.

  In solution polymerization, a predetermined organic solvent, a monomer, a polymerization initiator, and a chain transfer agent used as necessary are generally charged in a polymerization tank, and the number is stirred in a nitrogen stream or at the reflux temperature of the organic solvent. The reaction is performed by heating for a period of time. In this case, at least a part of the organic solvent, the monomer and / or the polymerization initiator may be sequentially added.

  Examples of the organic solvent for polymerization include aromatics such as benzene, toluene, ethylbenzene, N-propylbenzene, t-butylbenzene, o-xylene, m-xylene, p-xylene, tetralin, decalin, and aromatic naphtha. Hydrocarbons; for example, aliphatic or alicyclic hydrocarbons such as n-hexane, n-heptane, n-octane, i-octane, n-decane, dipentene, petroleum spirit, petroleum naphtha, turpentine oil; , Ethyl acetate, n-butyl acetate, n-amyl acetate, 2-hydroxyethyl acetate, 2-butoxyethyl acetate, 3-methoxybutyl acetate, methyl benzoate and the like; for example, acetone, methyl ethyl ketone, methyl-i- Ketones such as butyl ketone, isophorone, cyclohexanone, methylcyclohexanone; For example, glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether; for example, methyl alcohol, ethyl alcohol, n-propyl alcohol, i -Alcohols such as propyl alcohol, n-butyl alcohol, i-butyl alcohol, s-butyl alcohol, t-butyl alcohol; These organic solvents can be used alone or in admixture of two or more.

  As said polymerization initiator, it is possible to use the organic peroxide, an azo compound, etc. which can be used by normal solution polymerization. Examples of such organic peroxides include t-butyl hydroperoxide, cumene hydroxide, dicumyl peroxide, benzoyl peroxide, lauroyl peroxide, caproyl peroxide, and di-i-propyl peroxydicarbonate. , Di-2-ethylhexyl peroxydicarbonate, t-butyl peroxybivalate, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, 2,2-bis (4,4- Di-t-amylperoxycyclohexyl) propane, 2,2-bis (4,4-di-t-octylperoxycyclohexyl) propane, 2,2-bis (4,4-di-α-cumylperoxycyclohexyl) ) Propane, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) ) Butane, 2,2-bis (4,4-di-t-octylperoxycyclohexyl) butane, and the like. Examples of the azo compound include 2,2′-azobis-i-butyronitrile, 2,2 ′. -Azobis-2,4-dimethylvaleronitrile, 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, etc. can be mentioned.

  Usually, the amount of the polymerization initiator used is preferably 0.01 to 2.0 parts by weight, more preferably 0.1 to 1.0 parts by weight with respect to 100 parts by weight of the monomer component.

  In the production of the (meth) acrylic polymer used in the present invention, it is normal not to use a chain transfer agent. However, it should be used as necessary within the range that does not impair the object and effect of the present invention. Is possible. A conventionally well-known thing can be used suitably as such a chain transfer agent.

  As superposition | polymerization temperature, it is 30-180 degreeC normally, It is preferable that it is 40-150 degreeC, and it is more preferable that it is 50-90 degreeC.

  The pressure-sensitive adhesive composition containing a glycol ester component used in the present invention preferably contains 0.1 to 3.0 parts by weight of the glycol ester component with respect to 100 parts by weight of the (meth) acrylic polymer. 0.2 to 1.5 parts by weight is more preferable, and 0.2 to 1.0 part by weight is further preferable. When the content of the glycol ester component is within the above range, it is preferable from the viewpoint of adhesion.

  A crosslinking agent can be added to the pressure-sensitive adhesive composition containing the glycol ester component used in the present invention.

  As the cross-linking agent, a polyfunctional compound is used, and an organic cross-linking agent and a polyfunctional metal chelate are exemplified. Examples of the organic crosslinking agent include an epoxy crosslinking agent, an isocyanate crosslinking agent, a carbodiimide crosslinking agent, an imine crosslinking agent, an oxazoline crosslinking agent, an aziridine crosslinking agent, and a peroxide crosslinking agent. A polyfunctional metal chelate is one in which a polyvalent metal atom is covalently or coordinately bonded to an organic compound. Examples of polyvalent metal atoms include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti, and the like. Can be mentioned. Examples of the atom in the organic compound that is covalently bonded or coordinated include an oxygen atom, and examples of the organic compound include an alkyl ester, an alcohol compound, a carboxylic acid compound, an ether compound, and a ketone compound. These crosslinking agents can be used alone or in combination of two or more. Among these, an isocyanate type crosslinking agent is preferable.

  Examples of the isocyanate crosslinking agent include aromatic polyisocyanates such as xylylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate, and tolylene diisocyanate; for example, hexamethylene diisocyanate, isophorone diisocyanate, and hydrogenation of the aromatic polyisocyanate compound. Polyisocyanate compounds derived from various polyisocyanates such as aliphatic or alicyclic polyisocyanates such as products; dimers or trimers of these polyisocyanates or adducts of these polyisocyanates and polyols such as trimethylolpropane Among these isocyanate compounds, hexamethylene diisocyanate is particularly preferable.

  These isocyanate compounds are manufactured by Nippon Polyurethane Industry Co., Ltd. “Coronate HX”, “Coronate HL-S”, “Coronate 2234” “Aquanate 200”, “Aquanate 210”, manufactured by Sumitomo Bayer Urethane Co., Ltd. “Death Module N3400”, “Duranate E-405-80T”, “Duranate 24A-100”, “Duranate TSE-100” manufactured by Asahi Kasei Co., Ltd., “Takenate D-110N” manufactured by Mitsui Takeda Chemical Co., Ltd. What is marketed by brand names, such as "Takenate D-120N", "Takenate M-631N", "MT-Oresta-NP1200", can be used conveniently.

  The amount of the crosslinking agent having an isocyanate group is preferably 0.1 to 1.5 equivalent, more preferably 0.3 to 1.2 equivalent as an isocyanate group with respect to the hydroxyl equivalent of the (meth) acrylic polymer. Preferably, 0.3 to 1.0 equivalent is more preferable.

  The pressure-sensitive adhesive composition containing the glycol ester component used in the present invention contains the crosslinking agent having the isocyanate group, and may further contain a crosslinking catalyst. As the cross-linking catalyst, a metal catalyst can be used, and a general isocyanate cross-linking catalyst such as a Sn (tin) -based catalyst can be used as the metal catalyst. Dibutyltin dilaurate or the like has pot life and catalytic effect. Can be preferably used.

  In addition, the pressure-sensitive adhesive composition containing a glycol ester component used in the present invention usually has a (meth) acrylic polymer, a glycol ester component, and a crosslinking agent having an isocyanate group, if necessary, usually. Formulations blended in the pressure-sensitive adhesive composition, for example, solvents, weather resistance stabilizers, tackifiers, softeners, dyes, pigments, inorganic fillers and the like can be blended as appropriate. These are preferably 30 parts by weight or less, more preferably 20 parts by weight or less, and particularly preferably 10 parts by weight or less based on 100 parts by weight of the (meth) acrylic polymer.

  The pressure-sensitive adhesive composition containing the glycol ester component used in the present invention can be made to have a non-volatile content of 20 to 50% by containing a solvent. The solvent is not particularly limited as long as it does not react with the constituents of the pressure-sensitive adhesive composition, dissolves the (meth) acrylic polymer, and is applied and dried at an appropriate rate after the pressure-sensitive adhesive composition is applied. The viscosity of the pressure-sensitive adhesive composition containing the glycol ester component used in the present invention is preferably about 300 to 5000 mPa · s from the viewpoint of coating properties and the like.

(3) Step of forming a laminate A roll laminator or the like connects the polarizing plate and the transfer sheet so that the layer containing the glycol ester component of the obtained transfer sheet is in contact with the transparent protective film of the polarizing plate. A laminated body is formed by bonding. The laminate has a layer structure composed of a substrate of a transfer sheet / a layer containing a glycol ester component / a transparent protective film / a polarizer / a transparent protective film. Moreover, when a transfer sheet has a peeling sheet, it is necessary to peel the said peeling sheet before bonding.

  The temperature at the time of bonding is not particularly limited, and may be room temperature. The pressure at the time of bonding is not particularly limited and can be determined as appropriate.

(4) Step of peeling the transfer sheet from the laminate The glycol ester component can be transferred onto the polarizing plate by peeling the transfer sheet from the laminate. As described above, the transferred glycol ester component only needs to be present on part or all of the surface of the transparent protective film that comes into contact with the pressure-sensitive adhesive layer, and its presence form is not particularly limited. It may exist uniformly on the surface of the transparent protective film that comes into contact with or may be unevenly distributed. Further, it may exist as a layer containing a glycol ester component.

  After peeling the base material of the transfer sheet, the amount of glycol ester component transferred can be confirmed by performing elemental analysis of the surface of the polarizing plate. The amount of transfer can be confirmed by the method described in the examples.

  In the production method of the present invention, the adhesive layer can be applied to the pressure-sensitive adhesive layer even in a humid environment by a very simple method of transferring the glycol ester component onto the polarizing plate from the transfer sheet having a layer containing the glycol ester component. Thus, a polarizing plate that can exhibit high adhesion can be produced.

  Further, in the production method of the present invention, as described above, the transfer sheet is used to transfer the glycol ester component on the transparent protective film of the polarizing plate, but on the transparent protective film of the polarizing plate, You may form a glycol type ester component as a layer containing a glycol type ester component by apply | coating the adhesive composition containing the said glycol type ester component directly. The glycol ester component can also be obtained by spraying the glycol ester component on the transparent protective film of the polarizing plate or by wiping the surface of the polarizing plate with a material containing the glycol ester component (for example, waste). Can be present on the transparent protective film of the polarizing plate.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and Comparative Examples.

Production Example 1 Production of Polarizing Plate (1) (Production of Polarizer)
A 75 μm-thick polyvinyl alcohol film (polymerization degree: 2300, saponification degree: 99.9 mol%, width: 1000 mm, thickness: 75 μm, manufactured by Kuraray Co., Ltd .: VF-PS7500) in pure water at 30 ° C. The film was stretched to a stretch ratio of 2.5 times while being immersed for 60 seconds. Subsequently, it dye | stained for 45 second in the iodine aqueous solution (weight ratio: pure water / iodine (I) / potassium iodide (KI) = 100 / 0.01 / 1) of 30 degreeC. Thereafter, the film was stretched in a 4 wt% boric acid aqueous solution so that the stretching ratio was 5.8 times. After stretching, the film was immersed in pure water for 10 seconds and then dried at 50 ° C. for 3 minutes while maintaining the film tension to obtain a polarizer. This polarizer had a thickness of 25 μm and a moisture content of 14% by weight.

(Preparation of aqueous adhesive solution (1))
100 parts by weight of polyvinyl alcohol-based resin containing acetoacetyl group (average polymerization degree: 1200, saponification degree: 98.5 mol%, acetoacetyl group modification degree: 5 mol%), 50 parts by weight of methylol melamine, pure water An aqueous solution prepared by dissolving in (water temperature: 30 ° C.) and adjusting the solid content concentration to 3.7% by weight was prepared. An aqueous adhesive solution was prepared by adding 18 parts by weight of an alumina colloid aqueous solution (average particle size: 15 nm, solid content concentration: 10% by weight, positive charge) to 100 parts by weight of the aqueous solution. The viscosity of the adhesive aqueous solution was 9.6 mPa · s. The pH of the adhesive aqueous solution was in the range of 4 to 4.5. This is designated as an adhesive aqueous solution (1).

(Preparation of polarizing plate)
The adhesive aqueous solution (1) is applied to one side of a TAC film (trade name: TD-60UL, manufactured by Fuji Film Co., Ltd.), which is a transparent protective film, so that the thickness of the adhesive layer after drying is about 55 nm. And the transparent protective film with an adhesive bond layer was produced. Thereafter, the transparent protective film with an adhesive layer is bonded to both sides of the polarizer under a temperature condition of 23 ° C. by a roll machine so that the adhesive layer of the protective film and the polarizer are in contact with each other, and laminated. The body. The laminate was dried at 70 ° C. for 10 minutes to produce a polarizing plate (1).

Production Example 2 Production of Polarizing Plate (2) (Production of Acrylic Resin Film)
An acrylic resin (trade name: Acrypet VH, Tg: 113 ° C., manufactured by Mitsubishi Rayon Co., Ltd.) was vacuum-dried at 100 ° C. to deaerate moisture and residual oxygen. A twin screw extruder (equipment) in which a mixture obtained by adding 30 parts by weight of acrylic rubber (trade name: AR12, manufactured by Nippon Zeon Co., Ltd.) to 100 parts by weight of degassed acrylic resin was replaced with nitrogen from the raw material hopper to the extruder. Name: TEM35B, manufactured by Toshiba Machine Co., Ltd.), melted at a cylinder set temperature of 230 to 270 ° C., and pelletized to obtain raw material pellets. The raw material pellets were vacuum-dried at 100 ° C. and supplied to a single screw extruder (device name: SE-65, manufactured by Toshiba Machine Co., Ltd.) in which the material hopper to the extruder were replaced with nitrogen, and cylinder sets 230 to 270 After melting at ℃ and passing through a coat hanger type T-die, cooling with a chrome-plated casting roll at 120 ℃ and a cooled chrome-plated casting roll at 90 ℃, an acrylic system is used with a film winder A resin film (thickness: 40 μm) was obtained.

(Preparation of polarizing plate)
A polarizing plate (2) was produced in the same manner as in Production Example 1 except that the obtained acrylic resin film was used instead of the TAC film as the transparent protective film.

Production Example 3 Production of pressure-sensitive adhesive composition solution (A) (production of acrylic polymer solution (A))
In a reaction vessel equipped with a thermometer, a stirrer, a nitrogen introduction tube, and a reflux condenser, 100 parts by weight of acetone and 100 parts by weight of toluene were placed. In another container, 95.0 parts by weight of butyl acrylate (BA) and 5.0 parts by weight of 4-hydroxybutyl acrylate (4HBA) were placed and mixed to obtain a monomer mixture. 25 parts by weight of 25% of the obtained monomer mixture was added to the reaction vessel. Next, after the air in the reaction vessel was replaced with nitrogen gas, 0.05 part by weight of azobisbutyronitrilo (AIBN) was added as a polymerization initiator, and the temperature of the mixture in the reaction vessel in a nitrogen atmosphere with stirring. Was heated to 70 ° C. to initiate the initial reaction. After the initial reaction was almost completed, 75% by weight of the remaining monomer mixture, 75 parts by weight, 80 parts by weight of acetone, 40 parts by weight of toluene, and 0.5 parts by weight of AIBN were sequentially added. The reaction was allowed to proceed for 5 hours, followed by a further 1.5 hours. Thereafter, a solution prepared by dissolving 1.0 part by weight of t-butyl peroxypivalate (trade name: perbutyl PV, manufactured by NOF Corporation) in 100 parts by weight of toluene was added dropwise over 1 hour, and then 1.5 Reacted for hours. After completion of the reaction, the reaction mixture was diluted with 300 parts by weight of methyl ethyl ketone to obtain an acrylic polymer solution (A) having a solid content of 35.8% by weight.

  The viscosity of the obtained acrylic polymer solution (A) is 1580 mPa · s, and the acrylic polymer contained in the acrylic polymer solution (A) has a glass transition temperature (Tg) of −55.9 ° C., weight. The average molecular weight (Mw) was about 440,000, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) was about 4.

(Preparation of pressure-sensitive adhesive composition solution (A))
To 100 parts by weight of the solid content of the resulting acrylic polymer solution (A), 0.5 parts by weight of tetraethylene glycol di-2-ethylhexanoate as a glycol ester component, hexamethylene diisocyanate crosslinking agent (trade name) : Coronate HX, NCO content: 21.3%, manufactured by Nippon Polyurethane Industry Co., Ltd. 2.5 parts by weight (number of equivalents of NCO relative to hydroxyl group equivalent of acrylic polymer in acrylic polymer solution (A)) 0.43 equivalents) was added and stirred sufficiently to obtain an adhesive composition solution (A). The obtained pressure-sensitive adhesive composition solution (A) had a solid content of about 35.0% by weight and a viscosity of 1500 mPa · s.

Production Example 4 Production of Adhesive Composition Solution (B) Tetraethylene glycol di-2-ethylhexano was added as a glycol ester component to 100 parts by weight of the solid content of the acrylic polymer solution (A) produced in Production Example 3. 1.0 parts by weight of ate, hexamethylene diisocyanate crosslinking agent (trade name: Coronate HX, NCO content: 21.3%, manufactured by Nippon Polyurethane Industry Co., Ltd.) (acrylic polymer solution (A)) Equivalent number of NCO: 0.43 equivalent) was added to the hydroxyl group equivalent of the acrylic polymer in the mixture, and stirred sufficiently to obtain an adhesive composition solution (B). The obtained pressure-sensitive adhesive composition solution (B) had a solid content of about 35.0% by weight and a viscosity of 1500 mPa · s.

Production Example 5 Production of Adhesive Composition Solution (C) To 100 parts by weight of the solid content of the acrylic polymer solution (A) produced in Production Example 3, hexamethylene diisocyanate crosslinking agent (trade name: Coronate HX, NCO content : 21.3%, manufactured by Nippon Polyurethane Industry Co., Ltd.) 2.5 parts by weight (the number of NCO equivalents: 0.43 equivalents relative to the hydroxyl group equivalent of the acrylic polymer in the acrylic polymer solution (A)) And sufficiently stirred to obtain a pressure-sensitive adhesive composition solution (C). The obtained pressure-sensitive adhesive composition solution (C) had a solid content of about 35.0% by weight and a viscosity of 1500 mPa · s.

Production Example 6 Production of Transfer Sheet (A) The above pressure-sensitive adhesive so that the coating amount after drying on a PET film (trade name: E5001, film thickness: 38 μm, manufactured by Toyobo Co., Ltd.) is 10 g / m ^2. The composition solution (A) was applied and dried at 70 ° C. for 60 seconds with a hot air circulation dryer to form an adhesive layer. After that, it was placed on a release paper surface-treated with a silicone release agent so that the pressure-sensitive adhesive layer surface was in contact with it, and was pressed and bonded through a pressure nip roll, and then bonded at 23 ° C. and 50% RH for 10 days. Curing was performed to obtain a transfer sheet (A).

Production Example 7 Production of Transfer Sheet (B) In Production Example 6, the transfer was performed in the same manner as in Production Example 6 except that the pressure-sensitive adhesive composition solution (B) was used instead of the pressure-sensitive adhesive composition solution (A). A sheet (B) was obtained.

Production Example 8 Production of Transfer Sheet (C) In Production Example 6, the transfer was performed in the same manner as in Production Example 6 except that the adhesive composition solution (C) was used instead of the adhesive composition solution (A). Sheet (C) was obtained.

Example 1
The release paper is peeled from the transfer sheet (A) obtained in Production Example 6, and the pressure-sensitive adhesive layer of the transfer sheet (A) is in contact with one transparent protective film of the polarizing plate (1) obtained in Production Example 1. As described above, the transfer sheet (A) and the polarizing plate (1) were bonded together with a roller and allowed to stand at room temperature for 5 minutes. Thereafter, the transfer sheet was peeled off from the polarizing plate to transfer the glycol ester component to obtain a polarizing plate to which the glycol ester component was transferred.

Examples 2 to 4, Comparative Examples 1 and 2
Except having changed the kind of a transfer sheet and a polarizing plate as shown in Table 1, the polarizing plate by which the glycol type ester component was transcribe | transferred by the method similar to Example 1 was obtained.

  The following evaluation was performed about the polarizing plate produced in Examples 1-4 and Comparative Examples 1 and 2. FIG. The results are shown in Table 1.

<Adhesion test under humidified environment>
Regarding the polarizing plates obtained in Examples 1 to 4 and Comparative Examples 1 and 2, a laminated film (3D FPR film) cut to 5 cm × 2.5 cm on the surface of the polarizing plate from which the transfer sheet was peeled off was as follows. It was made to adhere | attach using the solution of the acrylic adhesive composition produced by the method, and it was set as the measurement sample. The thickness of the pressure-sensitive adhesive layer formed from the acrylic pressure-sensitive adhesive composition was 20 μm. The obtained measurement sample was measured at 60 ° C. and 95% R.D. H. It was put in the environment for 6 hours, and the confirmation of peeling was evaluated according to the following criteria.
○: There is no lifting at the end of the laminated film.
X: The end of the laminated film is lifted.

(Preparation of acrylic pressure-sensitive adhesive composition)
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser, 100 parts by weight of butyl acrylate, 5 parts by weight of acrylic acid, 1 part by weight of 2-hydroxyethyl acrylate, 2, 2 as a polymerization initiator After charging 0.1 parts by weight of '-azobisisobutyronitrile with 100 parts by weight of ethyl acetate and introducing nitrogen gas with gentle stirring to replace nitrogen, the liquid temperature in the flask was kept at around 55 ° C. Then, a polymerization reaction was performed for 8 hours to prepare an acrylic polymer solution having a weight average molecular weight of 2.2 million.
0.30 parts of an isocyanate crosslinking agent (adduct of tolylene diisocyanate of trimethylolpropane, trade name: Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.) per 100 parts of the solid content of the obtained acrylic polymer solution A solution of an acrylic pressure-sensitive adhesive composition having a solid content of 11% by weight was prepared by blending.

<Confirmation of transfer amount of glycol ester component>
About the polarizing plate obtained in Examples 1-4 and Comparative Examples 1 and 2, the elemental analysis of the surface of the polarizing plate which peeled off the transfer sheet was performed, and the transfer amount of the glycol-type ester component was confirmed. The amount of transfer was confirmed by TOF-SIMS (TOF-SIMS5, manufactured by ION-TOF). The measurement conditions were as follows.
(Measurement condition)
Analysis device: TOF-SIMS5, ION-TOF irradiated primary ions: Bi ₃ ²⁺
Primary ion acceleration voltage: 25 kV
Measurement area: 300 μm square (uses a charge correction electron gun for measurement)

DESCRIPTION OF SYMBOLS 1 View side polarizing plate 2 Transparent protective film 3 Polarizer 4 Transparent protective film 5 Adhesive layer 6 Functional film 7 Functional laminated body 8 Liquid crystal cell 9 Back side polarizing plate 10 Transparent protective film 11 Polarizer 12 Transparent protective film 13 Back Light 14 Liquid crystal display device A Surface in contact with adhesive layer of transparent protective film

Claims (2)

A polarizing plate having a transparent protective film laminated on at least one surface of a polarizer, an adhesive layer, and a functional film are provided in this order, and the adhesive layer is laminated on the transparent protective film of the polarizing plate. A method for producing a polarizing plate used in a functional laminate,
Preparing a polarizing plate in which a transparent protective film is laminated on at least one surface of a polarizer,
Forming a transfer sheet having a layer containing a glycol ester component on a substrate;
A step of bonding the polarizing plate and the transfer sheet to form a laminate so that the layer containing the glycol ester component of the transfer sheet is in contact with the transparent protective film of the polarizing plate;
as well as,
Look including the step of peeling the transfer sheet from the laminate,
Has a glycol ester component to a surface in contact with the adhesive layer of the transparent protective film, the abundance of glycol ester component of the transparent protective film surface is polarized you characterized in that at least 5 atomic% Manufacturing method of light plate. The glycol ester component is represented by the following formula (1):

(Wherein R ¹ And R ² Are each independently an alkyl or aryl group having 1 to 20 carbon atoms, and R ³ Represents hydrogen or a methyl group, and n is an integer of 2 to 20)
The manufacturing method of the polarizing plate of Claim 1 characterized by the above-mentioned.

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