JP2009205141A - Adhesive polarizing plate, image display device, and method for manufacturing them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive polarizing plate having a transparent protective film only on one face of a polarizer and having an adhesive layer on the other face, and excellently maintaining adhesion with time between the polarizer and the adhesive layer even if placed in conditions of high temperature and high humidity. <P>SOLUTION: The adhesive polarizing plate is provided with the transparent protective film E only on one face of the polarizer P through a first adhesive layer G1, and the adhesive layer B on the other face of the polarizer P through a second adhesive layer G2. The second adhesive layer G2 is formed by solidifying an adhesive G2' after laminating the polarizer P and the adhesive layer B in the unsolidified state of the adhesive G2' forming the second adhesive layer G2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an adhesive polarizing plate in which a transparent protective film is provided only on one side of a polarizer and an adhesive layer is laminated on the other side, and a method for producing the same. Furthermore, the present invention relates to an image display device using the adhesive polarizing plate. Furthermore, the present invention relates to a method for manufacturing the image display device.

  In the liquid crystal display device, it is indispensable to dispose polarizing plates on both sides of the glass substrate on which the liquid crystal panel surface is formed because of the image forming method. In general, a polarizing plate is made of a polyvinyl alcohol-based film and a transparent protective film for a polarizer using triacetyl cellulose or the like on one or both sides of a polarizer made of a dichroic material such as iodine. What was bonded together with the agent is used.

  When adhering the polarizing plate to a liquid crystal cell or the like, an adhesive is usually used. In addition, the adhesive is provided as an adhesive layer in advance on one side of the polarizing plate because it has the merits of being able to fix the polarizing plate instantly and not requiring a drying step to fix the polarizing plate. . That is, an adhesive polarizing plate is generally used for attaching the polarizing plate.

  Necessary characteristics required for the pressure-sensitive adhesive layer include that the polarizing plate is attached to the liquid crystal panel when the polarizing plate is bonded to the liquid crystal cell in the case where the bonding position is wrong or foreign matter is caught in the bonding surface. It is required that it can be peeled off from the surface and pasted (reworked) again. Various types of pressure-sensitive adhesive layers that improve the reworkability have been proposed (Patent Document 1).

JP 2004-20896 A

  The said adhesive layer is normally applied to the polarizing plate which provided the transparent protective film on both surfaces of the polarizer, and the adhesive layer is laminated | stacked on the transparent protective film in the said polarizing plate. On the other hand, from the viewpoint of thinning, a polarizing plate provided with a transparent protective film only on one side of the polarizer is used. In the polarizing plate, an adhesive layer is provided on the other side of the polarizer. However, the adhesiveness between the pressure-sensitive adhesive layer and the polarizer is worse than that of the transparent protective film. Therefore, if rework is performed when the thin polarizing plate is used, adhesive residue or the like is generated on the liquid crystal panel, and the efficiency of rework is poor. In order to improve the adhesion, an undercoat layer may be provided in advance as an easy-adhesion layer on the polarizer side, and an adhesive layer may be bonded to the undercoat layer. However, even when the undercoat layer is provided, it is difficult to sufficiently satisfy the adhesiveness over time under high temperature and high humidity conditions.

  The present invention is a pressure-sensitive adhesive polarizing plate having a transparent protective film only on one side of the polarizer and having an adhesive layer on the other side, and when placed under conditions of high temperature and high humidity, It is an object of the present invention to provide a pressure-sensitive adhesive polarizing plate that can maintain good adhesion over time between a polarizer and a pressure-sensitive adhesive layer.

  Another object of the present invention is to provide an image display device having the pressure-sensitive adhesive polarizing plate and a method for producing the same.

  As a result of intensive studies, the inventors of the present application have found that the above-mentioned problems can be solved by the following pressure-sensitive adhesive polarizing plate, and have reached the present invention.

That is, in the present invention, the transparent protective film (E) is provided only on one side of the polarizer (P) via the first adhesive layer (G1), and on the other side of the polarizer (P), An adhesive polarizing plate in which the adhesive layer (B) is provided via the second adhesive layer (G2),
The second adhesive layer (G2) includes the polarizer (P) and the pressure-sensitive adhesive layer (B) in a state where the adhesive (G2 ′) forming the second adhesive layer (G2) is not solidified. The present invention relates to a pressure-sensitive adhesive polarizing plate characterized by being formed by solidifying the adhesive (G2 ′) after bonding.

  In the pressure-sensitive adhesive polarizing plate, the adhesive forming the second adhesive layer (G2) is preferably a polyvinyl alcohol adhesive, an isocyanate adhesive, a cyanoacrylate adhesive, or an aziridine adhesive.

In the present invention, the transparent protective film (E) is provided only on one side of the polarizer (P) via the first adhesive layer (G1), and on the other side of the polarizer (P), A method for producing an adhesive polarizing plate in which an adhesive layer (B) is provided via a second adhesive layer (G2),
In the lamination of the polarizer (P) and the pressure-sensitive adhesive layer (B), the adhesive (G2 ′) is not solidified by the adhesive (G2 ′) forming the second adhesive layer (G2). It is related with the manufacturing method of the adhesion type polarizing plate characterized by sticking a polarizer (P) and an adhesive layer (B) in the state, and solidifying the said adhesive agent (G2 ') after that.

  In the manufacturing method of the pressure-sensitive adhesive polarizing plate, the adhesive forming the second adhesive layer (G2) is a polyvinyl alcohol-based adhesive, an isocyanate-based adhesive, a cyanoacrylate-based adhesive, or an aziridine-based adhesive. Is preferred.

  The present invention also relates to an image display device having the pressure-sensitive adhesive polarizing plate.

  Further, the present invention is a method for manufacturing the image display device, a roll raw fabric preparation step of preparing a long sheet of the pressure-sensitive adhesive polarizing plate as a roll raw fabric, a sheet product is fed out from the roll raw fabric, and cut A cutting step of cutting the pressure-sensitive adhesive polarizing plate into a predetermined size using means, and a bonding step of bonding to the optical display unit via the pressure-sensitive adhesive layer (B) of the pressure-sensitive adhesive polarizing plate after the cutting step; The present invention relates to a method for manufacturing an image display apparatus having

  The adhesive polarizing plate of the present invention has a transparent protective film (E) only on one side of the polarizer (P), and a thin type having an adhesive layer (B) on the other side of the polarizer (P). Although it is an adhesive type polarizing plate, a second adhesive layer (G2) is provided between the adhesive layer (B) and the polarizer (P), and the adhesive layer (B) and the polarizer ( P) has good adhesion. The second adhesive layer (G2) is not formed on the polarizer (P) in advance and then bonded to the pressure-sensitive adhesive layer (B), but the second adhesive layer (G2) is formed. The adhesive (G2 ′) is formed by applying to the polarizer (P) and the pressure-sensitive adhesive layer (B) in a state where the adhesive (G2 ′) is not solidified, and solidifying them after bonding them together. In the present invention, the adhesion between the pressure-sensitive adhesive layer (B) and the polarizer (P) is further improved by the second adhesive layer (G2), and the polarizer and the pressure-sensitive adhesive layer even under conditions of high temperature and high humidity. The adhesiveness over time can be maintained, and rework can be performed well over time.

  In addition, since the pressure-sensitive adhesive polarizing plate of the present invention can be easily reworked, work efficiency is high when manufacturing an image display device using the pressure-sensitive adhesive polarizing plate. In particular, it is suitable in the manufacturing method of the image display apparatus which performs from the roll original fabric preparation process of an adhesion type polarizing plate to a cutting process and the bonding process bonded together to an optical display unit as a series of processes.

It is a schematic sectional drawing of the adhesion type polarizing plate by preferable embodiment of this invention. It is a schematic sectional drawing of an example of the manufacturing method of the adhesion type polarizing plate of this invention. It is a schematic sectional drawing of an example of the manufacturing method of the adhesion type polarizing plate of this invention. It is a flowchart which shows an example of the manufacturing method of the conventional optical display unit. It is a flowchart of an example of the manufacturing method of the image display apparatus of this invention. It is a flowchart of an example of the manufacturing method of the image display apparatus of this invention. It is a figure for demonstrating an example of a structure of the manufacturing system of an image display apparatus. It is a figure for demonstrating an example of a structure of the manufacturing system of an image display apparatus.

  Hereinafter, the pressure-sensitive adhesive polarizing plate of the present invention will be described with reference to FIG. In the pressure-sensitive adhesive polarizing plate of the present invention, for example, as shown in FIG. 1, the transparent protective film (E) is provided only on one side of the polarizer (P) via the first adhesive layer (G1). On the other surface of the polarizer (P), a pressure-sensitive adhesive layer (B) is provided via a second adhesive layer (G2). Although not shown, the pressure-sensitive adhesive polarizing plate of the present invention is provided with an easy-adhesion layer or an activation treatment on the transparent protective film (E), and the easy-adhesion layer and the adhesive layer (G1). ) Can be pasted together. Although not shown, a release sheet can be provided on the pressure-sensitive adhesive layer (B).

[Polarizer]
A polarizer refers to a film that can be converted from natural light or polarized light into arbitrary polarized light. Any appropriate polarizer may be adopted as the polarizer used in the present invention, but a polarizer that converts natural light or polarized light into linearly polarized light is preferably used.

  In the polarizing plate of this invention, arbitrary appropriate things can be employ | adopted as a polarizer (P) according to the objective. For example, dichroic substances such as iodine and dichroic dyes are adsorbed on hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films. And a polyene-based oriented film such as a uniaxially stretched product, a polyvinyl alcohol dehydrated product or a polyvinyl chloride dehydrochlorinated product. Further, a guest / host type O-type polarizer in which a liquid crystalline composition containing a dichroic substance and a liquid crystalline compound disclosed in US Pat. No. 5,523,863 is aligned in a certain direction, US Pat. An E-type polarizer or the like in which lyotropic liquid crystals disclosed in US Pat. No. 6,049,428 are aligned in a certain direction can also be used.

  Among such polarizers, from the viewpoint of having a high degree of polarization, a polarizer made of a polyvinyl alcohol film containing iodine is preferably used. Polyvinyl alcohol or a derivative thereof is used as a material for the polyvinyl alcohol film applied to the polarizer. Derivatives of polyvinyl alcohol include polyvinyl formal, polyvinyl acetal, and the like, olefins such as ethylene and propylene, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and their alkyl esters and acrylamide. Things. Polyvinyl alcohol having a polymerization degree of about 1000 to 10000 and a saponification degree of about 80 to 100 mol% is generally used.

  The polyvinyl alcohol film may contain an additive such as a plasticizer. Examples of the plasticizer include polyols and condensates thereof, and examples thereof include glycerin, diglycerin, triglycerin, ethylene glycol, propylene glycol, and polyethylene glycol. The amount of the plasticizer used is not particularly limited, but is preferably 20% by weight or less in the polyvinyl alcohol film.

  The polyvinyl alcohol film (unstretched film) is at least subjected to uniaxial stretching treatment and iodine dyeing treatment according to a conventional method. Furthermore, boric acid treatment and iodine ion treatment can be performed. Moreover, the polyvinyl alcohol film (stretched film) subjected to the treatment is dried according to a conventional method to form a polarizer.

  The stretching method in the uniaxial stretching treatment is not particularly limited, and either a wet stretching method or a dry stretching method can be employed. Examples of the stretching means of the dry stretching method include an inter-roll stretching method, a heated roll stretching method, and a compression stretching method. Stretching can also be performed in multiple stages. In the stretching means, the unstretched film is usually heated. Usually, the unstretched film has a thickness of about 30 to 150 μm. The stretch ratio of the stretched film can be appropriately set according to the purpose, but the stretch ratio (total stretch ratio) is about 2 to 8 times, preferably 3 to 6.5 times, more preferably 3.5 to 6 times. Is desirable. The thickness of the stretched film is preferably about 5 to 40 μm.

  The iodine staining treatment is performed by immersing the polyvinyl alcohol film in an iodine solution containing iodine and potassium iodide. The iodine solution is usually an iodine aqueous solution, and contains iodine and potassium iodide as a dissolution aid. The iodine concentration is about 0.01 to 1% by weight, preferably 0.02 to 0.5% by weight. The potassium iodide concentration is about 0.01 to 10% by weight, and further 0.02 to 8% by weight. It is preferable to use it.

  In the iodine dyeing treatment, the temperature of the iodine solution is usually about 20 to 50 ° C, preferably 25 to 40 ° C. The immersion time is usually about 10 to 300 seconds, preferably 20 to 240 seconds. In the iodine dyeing treatment, the iodine content and potassium content in the polyvinyl alcohol film are within the above ranges by adjusting the conditions such as the concentration of the iodine solution, the immersion temperature of the polyvinyl alcohol film in the iodine solution, and the immersion time. Adjust as follows. The iodine dyeing process may be performed at any stage before the uniaxial stretching process, during the uniaxial stretching process, or after the uniaxial stretching process.

  The boric acid treatment is performed by immersing a polyvinyl alcohol film in an aqueous boric acid solution. The boric acid concentration in the boric acid aqueous solution is about 2 to 15% by weight, preferably 3 to 10% by weight. The aqueous boric acid solution can contain potassium ions and iodine ions with potassium iodide. The potassium iodide concentration in the boric acid aqueous solution is preferably about 0.5 to 10% by weight, more preferably 1 to 8% by weight. A boric acid aqueous solution containing potassium iodide can provide a lightly colored polarizer, that is, a so-called neutral gray polarizer having a substantially constant absorbance over almost the entire wavelength range of visible light.

  For the iodine ion treatment, for example, an aqueous solution containing iodine ions with potassium iodide or the like is used. The potassium iodide concentration is preferably about 0.5 to 10% by weight, more preferably 1 to 8% by weight. In the iodine ion impregnation treatment, the temperature of the aqueous solution is usually about 15 to 60 ° C, preferably 25 to 40 ° C. The immersion time is usually about 1 to 120 seconds, preferably 3 to 90 seconds. The stage of iodine ion treatment is not particularly limited as long as it is before the drying process. It can also be performed after water washing described later.

  The polarizer can also contain zinc. Inclusion of zinc in the polarizer is preferable in terms of suppressing hue deterioration under a heating environment. The zinc content in the polarizer is preferably adjusted so that the zinc element is contained in the polarizer in an amount of 0.002 to 2% by weight. Furthermore, it is preferable to adjust to 0.01 to 1 weight%. When the zinc content in the polarizer is within the above range, the durability improving effect is good, which is preferable for suppressing the deterioration of the hue.

  A zinc salt solution is used for the zinc impregnation treatment. As the zinc salt, an inorganic salt compound of an aqueous solution such as zinc halides such as zinc chloride and zinc iodide, zinc sulfate, and zinc acetate is preferable. Among these, zinc sulfate is preferable because the retention rate of zinc in the polarizer can be increased. Various zinc complex compounds can be used for the zinc impregnation treatment. The concentration of zinc ions in the zinc salt aqueous solution is about 0.1 to 10% by weight, preferably 0.3 to 7% by weight. The zinc salt solution is preferably an aqueous solution containing potassium ions and iodine ions with potassium iodide or the like because zinc ions are easily impregnated. The potassium iodide concentration in the zinc salt solution is preferably about 0.5 to 10% by weight, more preferably 1 to 8% by weight.

  In the zinc impregnation treatment, the temperature of the zinc salt solution is usually about 15 to 85 ° C, preferably 25 to 70 ° C. The immersion time is usually about 1 to 120 seconds, preferably 3 to 90 seconds. In the zinc impregnation treatment, the zinc content in the polyvinyl alcohol film can be adjusted by adjusting conditions such as the concentration of the zinc salt solution, the immersion temperature of the polyvinyl alcohol film in the zinc salt solution, and the immersion time. The stage of the zinc impregnation treatment is not particularly limited, and may be before the iodine dyeing treatment, before the immersion treatment in the boric acid aqueous solution after the iodine dyeing treatment, during the boric acid treatment, or after the boric acid treatment. Further, it may be carried out simultaneously with the iodine dyeing treatment in the presence of a zinc salt in the iodine dyeing solution. The zinc impregnation treatment is preferably performed together with boric acid treatment. Moreover, a uniaxial stretching process can also be performed with a zinc impregnation process. Moreover, you may perform a zinc impregnation process in multiple times.

  The treated polyvinyl alcohol film (stretched film) can be subjected to a water washing step and a drying step according to a conventional method.

  The water washing step is usually performed by immersing a polyvinyl alcohol film in pure water. The water washing temperature is usually in the range of 5 to 50 ° C, preferably 10 to 45 ° C, more preferably 15 to 40 ° C. The immersion time is usually about 10 to 300 seconds, preferably about 20 to 240 seconds.

  Arbitrary appropriate drying methods, for example, natural drying, ventilation drying, heat drying, etc., can be adopted as the drying step. For example, in the case of heat drying, the drying temperature is typically 20 to 80 ° C., preferably 25 to 70 ° C., and the drying time is typically about 1 to 10 minutes. Further, the moisture content of the polarizer after drying is preferably 10 to 30% by weight, more preferably 12 to 28% by weight, and even more preferably 16 to 25% by weight. When the moisture content is excessively large, a laminated laminate in which a polarizer is bonded to an optical element or an isotropic film through an adhesive layer as described later, that is, when the polarizing plate is dried, the polarizer is dried. Accordingly, the degree of polarization tends to decrease. In particular, the orthogonal transmittance increases in a short wavelength region of 500 nm or less, that is, light of a short wavelength leaks, so that black display tends to be colored blue. On the other hand, if the moisture content of the polarizer is excessively small, problems such as local uneven defects (knic defects) are likely to occur.

  Arbitrary appropriate thickness may be employ | adopted as thickness of the polarizer (P) used for the polarizing plate of this invention. The thickness of the polarizer is typically 5 to 80 μm, preferably 10 to 50 μm, and more preferably 20 to 40 μm. If it is said range, it is excellent in an optical characteristic and mechanical strength.

[Transparent protective film]
As a material constituting the transparent protective film, for example, a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like is used. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) acrylic resins, cyclic Examples thereof include polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof.

  In addition, 1 or more types of arbitrary appropriate additives may be contained in the transparent protective film. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a release agent, a coloring inhibitor, a flame retardant, a nucleating agent, an antistatic agent, a pigment, and a coloring agent. The content of the thermoplastic resin in the transparent protective film is preferably 50 to 100% by weight, more preferably 50 to 99% by weight, still more preferably 60 to 98% by weight, and particularly preferably 70 to 97% by weight. . When content of the said thermoplastic resin in a transparent protective film is 50 weight% or less, there exists a possibility that the high transparency etc. which a thermoplastic resin originally has cannot fully be expressed.

  Moreover, as a transparent protective film, the polymer film as described in Unexamined-Japanese-Patent No. 2001-343529 (WO01 / 37007), for example, (A) thermoplastic resin which has a substituted and / or unsubstituted imide group in a side chain, ( B) Resin compositions containing thermoplastic resins having substituted and / or unsubstituted phenyl and nitrile groups in the side chains. A specific example is a film of a resin composition containing an alternating copolymer composed of isobutylene and N-methylmaleimide and an acrylonitrile / styrene copolymer. As the film, a film made of a mixed extruded product of the resin composition or the like can be used. Since these films have a small phase difference and a small photoelastic coefficient, problems such as unevenness due to the distortion of the polarizing plate can be eliminated, and since the moisture permeability is small, the humidification durability is excellent.

  Although the thickness of a transparent protective film can be determined suitably, generally it is about 1-500 micrometers from points, such as workability | operativity, such as intensity | strength and handleability, and thin layer property. 1-300 micrometers is especially preferable, 5-200 micrometers is more preferable, Furthermore, 5-150 micrometers, especially 20-100 micrometers is especially suitable in the case of a thin type.

  As the transparent protective film of the present invention, it is preferable to use at least one selected from cellulose resin, polycarbonate resin, cyclic polyolefin resin, and (meth) acrylic resin.

  Cellulose resin is an ester of cellulose and fatty acid. Specific examples of the cellulose ester resin include triacetyl cellulose, diacetyl cellulose, tripropionyl cellulose, dipropionyl cellulose and the like. Among these, triacetyl cellulose is particularly preferable. Many products of triacetylcellulose are commercially available, which is advantageous in terms of availability and cost. Examples of commercially available products of triacetyl cellulose include trade names “UV-50”, “UV-80”, “SH-80”, “TD-80U”, “TD-TAC”, and “UZ” manufactured by Fujifilm Corporation. -TAC "and" KC series "manufactured by Konica. In general, these triacetyl celluloses have an in-plane retardation (Re) of almost zero, but a thickness direction retardation (Rth) of about 60 nm.

  In addition, the cellulose resin film with a small thickness direction phase difference is obtained by processing the said cellulose resin, for example. For example, a base film such as polyethylene terephthalate, polypropylene, and stainless steel coated with a solvent such as cyclopentanone and methyl ethyl ketone is bonded to a general cellulose film and dried by heating (for example, at 80 to 150 ° C. for about 3 to 10 minutes). ) And then peeling the base film; a solution obtained by dissolving norbornene resin, (meth) acrylic resin, etc. in a solvent such as cyclopentanone, methyl ethyl ketone, etc. is applied to a general cellulose resin film and dried by heating ( For example, a method of peeling the coated film after 80 to 150 ° C. for about 3 to 10 minutes is mentioned.

  Moreover, as a cellulose resin film with a small thickness direction retardation, the fatty acid cellulose resin film which controlled the fat substitution degree can be used. Generally used triacetyl cellulose has an acetic acid substitution degree of about 2.8. Preferably, the Rth can be reduced by controlling the acetic acid substitution degree to 1.8 to 2.7. Rth can be controlled to be small by adding a plasticizer such as dibutyl phthalate, p-toluenesulfonanilide, acetyltriethyl citrate to the fatty acid-substituted cellulose resin. The addition amount of the plasticizer is preferably 40 parts by weight or less, more preferably 1 to 20 parts by weight, and still more preferably 1 to 15 parts by weight with respect to 100 parts by weight of the fatty acid cellulose resin.

  Specific examples of the cyclic polyolefin resin are preferably norbornene resins. The cyclic olefin-based resin is a general term for resins that are polymerized using a cyclic olefin as a polymerization unit, and is described in, for example, JP-A-1-240517, JP-A-3-14882, JP-A-3-122137, and the like. Resin. Specific examples include ring-opening (co) polymers of cyclic olefins, addition polymers of cyclic olefins, cyclic olefins and α-olefins such as ethylene and propylene (typically random copolymers), And graft polymers obtained by modifying them with an unsaturated carboxylic acid or a derivative thereof, and hydrides thereof. Specific examples of the cyclic olefin include norbornene monomers.

  Various products are commercially available as the cyclic polyolefin resin. As specific examples, trade names “ZEONEX” and “ZEONOR” manufactured by ZEON CORPORATION, product names “ARTON” manufactured by JSR Corporation, “TOPAS” manufactured by TICONA, and product names manufactured by Mitsui Chemicals, Inc. “APEL”.

  The (meth) acrylic resin preferably has a Tg (glass transition temperature) of 115 ° C. or higher, more preferably 120 ° C. or higher, still more preferably 125 ° C. or higher, and particularly preferably 130 ° C. or higher. When Tg is 115 ° C. or higher, the polarizing plate can be excellent in durability. Although the upper limit of Tg of the (meth) acrylic resin is not particularly limited, it is preferably 170 ° C. or lower from the viewpoint of moldability and the like. From the (meth) acrylic resin, a film having in-plane retardation (Re) and thickness direction retardation (Rth) of almost zero can be obtained.

  As the (meth) acrylic resin, any appropriate (meth) acrylic resin can be adopted as long as the effects of the present invention are not impaired. 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.). Preferably, poly (meth) acrylate C1-6 alkyl such as poly (meth) acrylate methyl is used. More preferred is a methyl methacrylate resin containing methyl methacrylate as a main component (50 to 100% by weight, preferably 70 to 100% by weight).

  Specific examples of (meth) acrylic resins include (meth) acrylic resins having a ring structure in the molecule described in, for example, Acrypet VH and Acrypet VRL20A manufactured by Mitsubishi Rayon Co., Ltd., and JP-A-2004-70296. And a high Tg (meth) acrylic resin system 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. 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. No. 146084 and the like.

  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. No. 131898, JP 2006-206881 A, JP 2006-265532 A, JP 2006-283013 A, JP 2006-299005 A, JP 2006-335902 A, and the like. It is done.

  In addition, as the (meth) acrylic resin, a thermoplastic resin having a glutarimide unit, a (meth) acrylic 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. -337492, JP-A-2006-337493, JP-A-2006-337569, and the like.

(Phase difference value of transparent protective film)
As the transparent protective film (E), a film having a small front refraction of less than 40 nm and a thickness direction retardation of less than 80 nm can be used as having a small birefringence and not converting the polarization state. Thus, an unstretched film is used suitably as a transparent protective film with small birefringence.

  The front phase difference Re is represented by Re = (nx−ny) × d. The thickness direction retardation Rth is represented by Rth = (nx−nz) × d. The Nz coefficient is represented by Nz = (nx−nz) / (nx−ny). [However, the refractive indexes in the slow axis direction, the fast axis direction, and the thickness direction of the film are nx, ny, and nz, respectively, and d (nm) is the thickness of the film. The slow axis direction is the direction that maximizes the refractive index in the film plane. ].

  On the other hand, by using a transparent protective film having a front retardation of 40 nm or more and / or a thickness direction retardation of 80 nm or more, the polarizer protective film can also function as a retardation plate. In that case, the front retardation and the thickness direction retardation can be appropriately adjusted to values required for optical compensation as a retardation plate. As such a retardation plate, a stretched transparent protective film can be suitably used.

  The retardation plate has a relationship of nx = ny> nz, nx> ny> nz, nx> ny = nz, nx> nz> ny, nz = nx> ny, nz> nx> ny, nz> nx = ny. Those satisfying the above are selected and used according to various applications. Note that ny = nz includes not only the case where ny and nz are completely the same, but also the case where ny and nz are substantially the same.

  For example, in a phase difference plate that satisfies nx> ny> nz, a surface plate having a front phase difference of 40 to 100 nm, a thickness direction phase difference of 100 to 320 nm, and an Nz coefficient of 1.8 to 4.5 is used. Is preferred. For example, for a retardation plate (positive A plate) that satisfies nx> ny = nz, it is preferable to use a retardation plate that satisfies a front phase difference of 100 to 200 nm. For example, for a retardation plate (negative A plate) that satisfies nz = nx> ny, it is preferable to use a retardation plate that satisfies a front phase difference of 100 to 200 nm. For example, in a retardation plate satisfying nx> nz> ny, it is preferable to use a retardation plate having a front phase difference of 150 to 300 nm and an Nz coefficient exceeding 0 and satisfying 0.7 or less. Further, as described above, for example, nx = ny> nz, nz> nx> ny, or nz> nx = ny can be used.

  Further, as the transparent protective film (E), any of those having a small birefringence that does not convert the polarization state and those that act as a retardation plate can be used.

  When using what acts as a phase difference plate for a transparent protective film (E), as the polymer material, for example, polyvinyl alcohol, polyvinyl butyral, polymethyl vinyl ether, polyhydroxyethyl acrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose , Polycarbonate, polyarylate, polysulfone, polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyphenylene sulfide, polyphenylene oxide, polyallylsulfone, polyamide, polyimide, polyolefin, polyvinyl chloride, cellulose resin, cyclic olefin resin (norbornene resin) ), Or these binary and ternary copolymers, graft copolymers, blends, etc. That. These polymer materials become an oriented product (stretched film) by stretching or the like.

  Examples of the liquid crystal polymer include various main chain types and side chain types in which a conjugated linear atomic group (mesogen) imparting liquid crystal alignment is introduced into the main chain or side chain of the polymer. . Specific examples of the main chain type liquid crystal polymer include a nematic orientation polyester liquid crystal polymer, a discotic polymer, and a cholesteric polymer having a structure in which a mesogenic group is bonded at a spacer portion that imparts flexibility. Specific examples of the side chain type liquid crystal polymer include polysiloxane, polyacrylate, polymethacrylate, or polymalonate as a main chain skeleton, and a nematic alignment-providing para-substitution through a spacer portion composed of a conjugated atomic group as a side chain. The thing etc. which have a mesogen part which consists of a cyclic compound unit are mentioned. These liquid crystal polymers, for example, develop a solution of a liquid crystal polymer on an alignment treatment surface such as a surface of a thin film such as polyimide or polyvinyl alcohol formed on a glass plate, or an oblique deposition of silicon oxide. Then, the heat treatment is performed.

  The retardation plate may have an appropriate retardation according to the purpose of use, such as those for the purpose of compensating for coloring, viewing angle, etc. due to birefringence of various wavelength plates and liquid crystal layers. It may be a laminate in which retardation plates are stacked to control optical characteristics such as retardation. In addition, the film which has the said phase difference can be separately bonded together to the transparent film which does not have a phase difference, and the said function can also be provided.

  In addition, an optically compensated phase difference plate in which an alignment layer of a liquid crystal polymer, particularly an optically anisotropic layer composed of a tilted alignment layer of a discotic liquid crystal polymer, is supported by a triacetyl cellulose film in order to achieve a wide viewing angle with good visibility. Etc. can also be used.

[First adhesive layer]
The transparent protective film (E) and the polarizer (P) are laminated via the first adhesive layer (G1). At this time, it is desirable to laminate both of them with an adhesive layer without an air gap. The first adhesive layer (G1) is formed of an adhesive (G1 ′). The kind in particular of adhesive (G1 ') is not restrict | limited, A various thing can be used.

  The first adhesive layer (G1) used for laminating the polarizer (P) and the transparent protective film (E) is not particularly limited as long as it is optically transparent, water-based, solvent-based, hot-melt-based, radical curing. Various types of molds are used, and water-based adhesives or radical curable adhesives are preferred.

  The water-based adhesive forming the adhesive layer (G1) is not particularly limited, and examples thereof include vinyl polymer, gelatin, vinyl latex, polyurethane, isocyanate, polyester, and epoxy. It can be illustrated. Such an adhesive layer composed of an aqueous adhesive can be formed as an aqueous solution coating / drying layer, etc., but when preparing the aqueous solution, a catalyst such as a crosslinking agent, other additives, and an acid can be used as necessary. Can be blended. As the water-based adhesive, an adhesive containing a vinyl polymer is preferably used, and the vinyl polymer is preferably a polyvinyl alcohol resin. The polyvinyl alcohol-based resin can contain a water-soluble crosslinking agent such as boric acid, borax, glutaraldehyde, melamine, or oxalic acid. In particular, when a polyvinyl alcohol polymer film is used as the polarizer, it is preferable from the viewpoint of adhesiveness to use an adhesive containing a polyvinyl alcohol resin. Furthermore, an adhesive containing a polyvinyl alcohol-based resin having an acetoacetyl group is more preferable from the viewpoint of improving durability.

  Polyvinyl alcohol resin is polyvinyl alcohol obtained by saponifying polyvinyl acetate; a derivative thereof; a saponified product of a copolymer of vinyl acetate and a monomer having copolymerizability; Examples thereof include modified polyvinyl alcohols that have been converted into ethers, ethers, grafts, or phosphoric esters. 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 polyvinyl alcohol resins can be used singly or in combination of two or more.

  The polyvinyl alcohol-based resin is not particularly limited, but from the viewpoint of adhesiveness, the average degree of polymerization is about 100 to 5000, preferably 1000 to 4000, the average saponification degree is about 85 to 100 mol%, preferably 90 to 100 mol%. It is.

  A polyvinyl alcohol-based resin containing an acetoacetyl group is obtained by reacting a polyvinyl alcohol-based resin with diketene by a known method. For example, a method in which a polyvinyl alcohol resin is dispersed in a solvent such as acetic acid and diketene is added thereto, and a polyvinyl alcohol resin is previously dissolved in a solvent such as dimethylformamide or dioxane, and diketene is added thereto. And the like. Another example is a method in which diketene gas or liquid diketene is brought into direct contact with polyvinyl alcohol.

  The degree of acetoacetyl group modification of the polyvinyl alcohol-based 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 is insufficient and unsuitable. The degree of acetoacetyl group modification is preferably about 0.1 to 40 mol%, more preferably 1 to 20 mol%, and particularly preferably 2 to 7 mol%. When the acetoacetyl group modification degree exceeds 40 mol%, the effect of improving water resistance is small. The degree of acetoacetyl modification is a value measured by NMR.

  As a crosslinking agent, what is used for the polyvinyl alcohol-type adhesive agent can be especially used without a restriction | limiting. A compound having at least two functional groups having reactivity with the polyvinyl alcohol resin can be used. For example, alkylene diamines having two alkylene groups and two amino groups such as ethylenediamine, triethylenediamine, hexamethylenediamine; tolylene diisocyanate, hydrogenated tolylene diisocyanate, trimethylolpropane tolylene diisocyanate adduct, triphenylmethane triisocyanate, methylene bis (Isocyanates such as 4-phenylmethane triisocyanate, isophorone diisocyanate and their ketoxime block product or phenol block product; ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin di or triglycidyl ether, 1,6-hexane Diol diglycidyl ether, trimethylolpropane triglycidyl ether, jig Epoxys such as sidylaniline and diglycidylamine; monoaldehydes such as formaldehyde, acetaldehyde, propionaldehyde, and butyraldehyde; Aldehydes: amino-formaldehyde resins such as methylol urea, methylol melamine, alkylated methylol urea, alkylated methylolated melamine, acetoguanamine, condensate of benzoguanamine and formaldehyde; further sodium, potassium, magnesium, calcium, aluminum, iron And salts of divalent metals such as nickel or trivalent metals and oxides thereof, among which amino-formaldehyde resins and dia Dehydrates are preferred, amino-formaldehyde resins are preferably compounds having a methylol group, and dialdehydes are preferably glyoxal, particularly methylol melamine, which is a compound having a methylol group. As the crosslinking agent, a coupling agent such as a silane coupling agent or a titanium coupling agent can be used.

  The amount of the crosslinking agent can be appropriately designed according to the type of polyvinyl alcohol resin, etc., but is usually about 4 to 60 parts by weight, preferably 10 to 55 parts by weight with respect to 100 parts by weight of the polyvinyl alcohol resin. Degree, more preferably 20 to 50 parts by weight. In such a range, good adhesiveness can be obtained.

  In order to improve the durability, a polyvinyl alcohol resin containing an acetoacetyl group is used. Also in this case, the crosslinking agent is used in the range of about 4 to 60 parts by weight, preferably about 10 to 55 parts by weight, and more preferably 20 to 50 parts by weight, as described above, with respect to 100 parts by weight of the polyvinyl alcohol resin. Is preferred. When the amount of the crosslinking agent is too large, the reaction of the crosslinking agent proceeds in a short time and the adhesive tends to gel. As a result, the pot life as an adhesive is extremely shortened, making industrial use difficult. From this point of view, the blending amount of the crosslinking agent is used in the above blending amount. However, since the resin solution of the present invention contains the metal compound colloid, the blending amount of the crosslinking agent is large as described above. Even if it exists, it can be used with good stability.

  As the adhesive, a resin solution containing a polyvinyl alcohol resin, a crosslinking agent, and a metal compound colloid having an average particle size of 1 to 100 nm is preferably used. The resin solution is usually used as an aqueous solution. The concentration of the resin solution is not particularly limited, but is 0.1 to 15% by weight, preferably 0.5 to 10% by weight in consideration of coating properties and storage stability.

  The metal compound colloid is one in which fine particles are dispersed in a dispersion medium, and is electrostatically stabilized due to mutual repulsion of the same kind of charge of the fine particles, and has permanent stability. The average particle diameter of the metal compound colloid (fine particles) is 1 to 100 nm. When the average particle diameter of the colloid is within the above range, the metal compound can be dispersed substantially uniformly in the adhesive layer, the adhesiveness can be ensured, and the nick can be suppressed. The range of the average particle diameter is considerably smaller than the wavelength range of visible light, and even if the transmitted light is scattered by the metal compound in the formed adhesive layer, the polarization characteristics are not adversely affected. The average particle size of the metal compound colloid is preferably 1 to 100 nm, more preferably 1 to 50 nm.

  Various types of metal compound colloids can be used. For example, colloids of metal compounds such as alumina, silica, zirconia, titania, tin oxide, aluminum silicate, calcium carbonate, and magnesium silicate; colloids of metal salts such as zinc carbonate, barium carbonate, and calcium phosphate And colloids of minerals such as celite, talc, clay and kaolin.

  The metal compound colloid is dispersed in a dispersion medium and exists in a state of a colloid solution. The dispersion medium is mainly water. In addition to water, other dispersion media such as alcohols can also be used. The solid content concentration of the metal compound colloid in the colloid solution is not particularly limited, but is generally about 1 to 50% by weight, and more preferably 1 to 30% by weight. In addition, as the metal compound colloid, those containing an acid such as nitric acid, hydrochloric acid, and acetic acid as a stabilizer can be used.

  Metal compound colloids are electrostatically stabilized and can be classified into those having a positive charge and those having a negative charge. Metal compound colloids are non-conductive materials. Positive charge and negative charge are distinguished by the charge state of the colloidal surface charge in the solution after the adhesive preparation. The charge of the metal compound colloid can be confirmed, for example, by measuring the zeta potential with a zeta potential measuring machine. The surface charge of a metal compound colloid generally varies with pH. Therefore, the charge in the state of the colloidal solution of the present application is affected by the pH of the adjusted adhesive solution. The pH of the adhesive solution is usually set in the range of 2 to 6, preferably 2.5 to 5, more preferably 3 to 5, and further 3.5 to 4.5. In the present invention, a metal compound colloid having a positive charge has a greater effect of suppressing the occurrence of nicks than a metal compound colloid having a negative charge. Examples of positively charged metal compound colloids include alumina colloids, zirconia colloids, titania colloids, and tin oxide colloids. Among these, alumina colloid is particularly preferable.

  A metal compound colloid is mix | blended in the ratio (converted value of solid content) of 200 weight part or less with respect to 100 weight part of polyvinyl alcohol-type resin. In addition, by setting the blending ratio of the metal compound colloid within the above range, the occurrence of nicks while ensuring the adhesion between the polarizer and the first transparent protective film (for example, the second transparent protective film on the other surface) Can be suppressed. The compounding ratio of the metal compound colloid is preferably 10 to 200 parts by weight, more preferably 20 to 175 parts by weight, and further preferably 30 to 150 parts by weight. When the compounding ratio of the metal compound colloid exceeds 200 parts by weight with respect to 100 parts by weight of the polyvinyl alcohol resin, the ratio of the polyvinyl alcohol resin in the adhesive is reduced, which is not preferable from the viewpoint of adhesiveness. The mixing ratio of the metal compound colloid is not particularly limited, but is preferably set to the lower limit of the above range in order to effectively suppress nicks.

  The viscosity of the resin solution that is an adhesive is not particularly limited, but a resin solution in the range of 1 to 50 mPa · s is used. The nick generated in the production of the polarizing plate tends to increase as the viscosity of the resin solution decreases. However, according to the polarizing plate adhesive of the present invention, a range of 1 to 20 mPa · s can be obtained. Even in the low viscosity range, the occurrence of nicks can be suppressed, and the occurrence of nicks can be suppressed regardless of the viscosity of the resin solution. A polyvinyl alcohol resin containing an acetoacetyl group cannot be increased in polymerization degree compared to a general polyvinyl alcohol resin and has been used at a low viscosity as described above. Even when a polyvinyl alcohol-based resin containing an acetyl group is used, the occurrence of nicks caused by the low viscosity of the resin solution can be suppressed.

  The method for preparing the resin solution that is an adhesive is not particularly limited. In general, a resin solution is prepared by mixing a polyvinyl alcohol resin and a crosslinking agent and blending a metal compound colloid with a mixture having an appropriate concentration. In addition, when a polyvinyl alcohol resin containing an acetoacetyl group is used as the polyvinyl alcohol resin or when the amount of the crosslinking agent is large, the polyvinyl alcohol resin and the metal are considered in consideration of the stability of the solution. After mixing the compound colloid, the cross-linking agent can be mixed in consideration of the use time of the resulting resin solution. In addition, the density | concentration of the resin solution which is an adhesive agent for polarizing plates can also be adjusted suitably after preparing a resin solution.

  When the adhesive layer (G1) is formed of a water-based adhesive or the like, the thickness of the adhesive layer (G1) is about 10 to 300 nm. The thickness of the adhesive layer is more preferably 10 to 200 nm, and still more preferably 20 to 150 nm, from the viewpoint of obtaining a uniform in-plane thickness and obtaining a sufficient adhesive force. As described above, the thickness of the adhesive layer (G1) is preferably designed to be larger than the average particle diameter of the metal compound colloid contained in the polarizing plate adhesive.

  After applying the water-based adhesive, the polarizer (P) and the transparent protective film (E) are bonded together using a roll laminator or the like. Application | coating of the said adhesive agent may be performed to any of a transparent protective film and a polarizer, and may be performed to both. After the bonding, a drying process is performed to form an adhesive layer composed of a coating dry layer. A drying temperature is about 5-150 degreeC, Preferably it is 30-120 degreeC, is 120 second or more, Furthermore, it is 300 second or more.

  Examples of the radical curable adhesive include various active energy ray curable types such as an electron beam curable type and an ultraviolet ray curable type, and a thermosetting type. preferable. In particular, an electron beam curable type is preferable. An electron beam curable adhesive can be used. By using an electron beam for the adhesive curing method used for laminating the polarizer and the transparent protective film (that is, dry lamination), a heating step such as an ultraviolet curing method is unnecessary, and the productivity is extremely high. can do.

  On the other hand, when the adhesive layer (G1) is formed of a curable adhesive (electron beam curable adhesive), the thickness of the adhesive layer (G1) is preferably 0.1 to 20 μm. Preferably, it is 0.2-10 micrometers, More preferably, it is 0.3-8 micrometers. When the thickness is small, the cohesive force of the adhesive force itself cannot be obtained, and the adhesive strength may not be obtained. If the thickness of the adhesive layer (G1) exceeds 20 μm, the cost increases and the shrinkage of the adhesive itself is affected, which may adversely affect the optical properties of the polarizing plate.

  After apply | coating an adhesive agent (G1 '), a polarizer (P) and a transparent protective film (E) are bonded together by a roll laminator. As described above, the moisture content of the polarizer used in this bonding step is preferably 10 to 30% by weight, more preferably 12 to 28% by weight, and 16 to 25% by weight. Is more preferable. By setting the moisture content within the above range, the degree of polarization can be kept high, and the occurrence of nicks and unevenness in appearance can be prevented.

  Furthermore, from the viewpoint of stabilizing optical properties such as the degree of polarization and hue, it is preferable that the transparent protective film (E) is bonded to the polarizer (P) and then dried at an appropriate drying temperature. From the viewpoint of optical properties, the drying temperature is preferably 90 ° C. or lower, more preferably 85 ° C. or lower, and further preferably 80 ° C. or lower. Moreover, although there is no minimum in drying temperature, when the efficiency and practicality of a process are considered, it is preferable that it is 50 degreeC or more. In addition, the drying temperature can be increased in stages within the above temperature range.

[Adhesive layer]
An appropriate pressure-sensitive adhesive can be used for forming the pressure-sensitive adhesive layer (B), and the type thereof is not particularly limited. Adhesives include rubber adhesives, acrylic adhesives, silicone adhesives, urethane adhesives, vinyl alkyl ether adhesives, polyvinyl alcohol adhesives, polyvinyl pyrrolidone adhesives, polyacrylamide adhesives, Examples thereof include cellulose-based pressure-sensitive adhesives.

  Among these pressure-sensitive adhesives, those having excellent optical transparency, suitable wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties, and excellent weather resistance and heat resistance are preferably used. An acrylic pressure-sensitive adhesive is preferably used as one exhibiting such characteristics.

  The acrylic pressure-sensitive adhesive is based on an acrylic polymer having a monomer unit of (meth) acrylic acid alkyl ester as a main skeleton. The (meth) acrylic acid alkyl ester refers to an acrylic acid alkyl ester and / or a methacrylic acid alkyl ester, and (meth) in the present invention has the same meaning. Examples of the (meth) acrylic acid alkyl ester constituting the main skeleton of the acrylic polymer include linear or branched alkyl groups having 1 to 20 carbon atoms. For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, (meth) acrylic Illustrative examples include isononyl acid, isomyristyl (meth) acrylate, and lauryl (meth) acrylate. These can be used alone or in combination. The average carbon number of these alkyl groups is preferably 3-9.

  In the acrylic polymer, one or more kinds of copolymerization monomers can be introduced by copolymerization for the purpose of improving adhesiveness and heat resistance. Specific examples of such copolymerization monomers include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, (meth) acrylic acid 6 Hydroxyl group-containing monomers such as hydroxyhexyl, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate and (4-hydroxymethylcyclohexyl) -methyl acrylate Carboxyl group-containing monomers such as (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid and crotonic acid; acid anhydrides such as maleic anhydride and itaconic anhydride Monomer-containing monomer; Caprolac of acrylic acid Adducts such as styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid, etc. And sulfonic acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate.

  In addition, (N-substituted) amides such as (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, etc. Monomer; (meth) acrylic acid aminoethyl, (meth) acrylic acid N, N-dimethylaminoethyl, (meth) acrylic acid t-butylaminoethyl and other (meth) acrylic acid alkylaminoalkyl monomers; (meth) acrylic (Meth) acrylic acid alkoxyalkyl monomers such as methoxyethyl acid and ethoxyethyl (meth) acrylate; N- (meth) acryloyloxymethylenesuccinimide, N- (meth) acryloyl-6-oxyhexamethylenesuccinimide, N- ( (Meta) acryloyl- -Succinimide monomers such as oxyoctamethylene succinimide and N-acryloylmorpholine; Maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide and N-phenylmaleimide; N-methylitaconimide, N-ethyl Itaconimide monomers such as itaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, N-laurylitaconimide, etc. are listed as examples of monomers for modification purposes. It is done.

  Further, as modifying monomers, vinyl acetate, vinyl propionate, N-vinyl pyrrolidone, methyl vinyl pyrrolidone, vinyl pyridine, vinyl piperidone, vinyl pyrimidine, vinyl piperazine, vinyl pyrazine, vinyl pyrrole, vinyl imidazole, vinyl oxazole, vinyl morpholine, N- Vinyl monomers such as vinylcarboxylic acid amides, styrene, α-methylstyrene, N-vinylcaprolactam; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; epoxy group-containing acrylic monomers such as glycidyl (meth) acrylate; (Meth) acrylic acid polyethylene glycol, (meth) acrylic acid polypropylene glycol, (meth) acrylic acid methoxyethylene glycol, (meth) acrylic acid meth Glycol acrylic ester monomers such as polypropylene glycol; acrylic acid ester monomers such as tetrahydrofurfuryl (meth) acrylate, fluorine (meth) acrylate, silicone (meth) acrylate and 2-methoxyethyl acrylate may also be used. it can.

  The acrylic polymer has (meth) acrylic acid alkyl ester as a main component in the weight ratio of all constituent monomers, and the ratio of the copolymer monomer in the acrylic polymer is not particularly limited, but the ratio of the copolymer monomer is The weight ratio of all the constituent monomers is preferably about 0 to 20%, about 0.1 to 15%, and more preferably about 0.1 to 10%.

  Among these copolymer monomers, a hydroxyl group-containing monomer and a carboxyl group-containing monomer are preferably used from the viewpoint of adhesiveness and durability. These monomers serve as reaction points with the crosslinking agent. Since a hydroxyl group-containing monomer, a carboxyl group-containing monomer, and the like are rich in reactivity with an intermolecular crosslinking agent, they are preferably used for improving the cohesiveness and heat resistance of the resulting pressure-sensitive adhesive layer.

  In the case of containing a hydroxyl group-containing monomer and a carboxyl group-containing monomer as the copolymerization monomer, these copolymerization monomers are used in the proportion of the copolymerization monomer, but the carboxyl group-containing monomer is 0.1 to 10% by weight and the hydroxyl group It is preferable to contain 0.01 to 2 weight% of containing monomers. The carboxyl group-containing monomer is more preferably 0.2 to 8% by weight, and further preferably 0.6 to 6% by weight. The hydroxyl group-containing monomer is more preferably 0.03 to 1.5% by weight, and even more preferably 0.05 to 1% by weight.

  The average molecular weight of the acrylic polymer is not particularly limited, but the weight average molecular weight is preferably about 300,000 to 2.5 million. The acrylic polymer can be produced by various known methods. For example, a radical polymerization method such as a bulk polymerization method, a solution polymerization method, or a suspension polymerization method can be appropriately selected. As the radical polymerization initiator, various known azo and peroxide initiators can be used. The reaction temperature is usually about 50 to 80 ° C., and the reaction time is 1 to 8 hours. Among the above production methods, the solution polymerization method is preferable, and ethyl acetate, toluene and the like are generally used as the solvent for the acrylic polymer. The solution concentration is usually about 20 to 80% by weight.

  The pressure-sensitive adhesive is preferably a pressure-sensitive adhesive composition containing a crosslinking agent. Examples of the polyfunctional compound that can be blended in the pressure-sensitive adhesive include organic crosslinking agents and polyfunctional metal chelates. Examples of the organic crosslinking agent include an epoxy crosslinking agent, an isocyanate crosslinking agent, an imine crosslinking agent, a peroxide crosslinking agent, and an aziridine crosslinking agent. These crosslinking agents can be used alone or in combination of two or more. As the organic crosslinking agent, an isocyanate crosslinking agent is preferable. A polyfunctional metal chelate is one in which a polyvalent metal 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 give. 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.

  The blending ratio of the base polymer such as the acrylic polymer and the crosslinking agent is not particularly limited, but is usually preferably about 0.001 to 20 parts by weight of the crosslinking agent (solid content) with respect to 100 parts by weight of the base polymer (solid content). Furthermore, about 0.01-15 weight part is preferable. As said crosslinking agent, an isocyanate type crosslinking agent is preferable. The isocyanate-based crosslinking agent is preferably about 0.001 to 2 parts by weight, more preferably about 0.01 to 1.5 parts by weight with respect to 100 parts by weight of the base polymer (solid content).

  Furthermore, the pressure-sensitive adhesive may include a tackifier, a plasticizer, glass fiber, glass beads, metal powder, other inorganic powders, a pigment, a colorant, a filler, an antioxidant, if necessary. Various additives may be used as appropriate, such as an agent, an ultraviolet absorber, a silane coupling agent, and the like without departing from the object of the present invention. Moreover, it is good also as an adhesive layer etc. which contain microparticles | fine-particles and show light diffusibility.

  As the additive, a silane coupling agent is suitable, and the silane coupling agent (solid content) is preferably about 0.001 to 10 parts by weight with respect to 100 parts by weight of the base polymer (solid content). It is preferable to add about 005 to 5 parts by weight. As the silane coupling agent, those conventionally known can be used without particular limitation. For example, epoxy groups such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, 2- (3,4 epoxycyclohexyl) ethyltrimethoxysilane -Containing silane coupling agent, 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N- (1,3-dimethylbutylidene) propylamine Amino group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane, (meth) acrylic group-containing silane coupling agents such as 3-methacryloxypropyltriethoxysilane, and isocyanates such as 3-isocyanatopropyltriethoxysilane Base It can be exemplified a silane coupling agent.

  The pressure-sensitive adhesive layer (B) is usually provided by applying a pressure-sensitive adhesive solution on a release sheet and drying the pressure-sensitive adhesive solution. The pressure-sensitive adhesive solution is prepared, for example, as a solution of about 10 to 40% by weight in which the composition is dissolved or dispersed in a solvent composed of a single solvent or a mixture of appropriate solvents such as toluene and ethyl acetate. As a coating method, a roll coating method such as reverse coating or gravure coating, a spin coating method, a screen coating method, a fountain coating method, a dipping method, or a spray method can be adopted. The release sheet provided with the pressure-sensitive adhesive layer (B) is used by a method for transferring the release sheet.

  The thickness of the pressure-sensitive adhesive layer (B) is usually about 3 to 100 μm, preferably 5 to 50 μm, and more preferably 10 to 40 μm.

  As a constituent material of the release sheet, paper, polyethylene, polypropylene, polyethylene terephthalate and other synthetic resin films, rubber sheets, paper, cloth, non-woven fabric, nets, foam sheets and metal foils, and appropriate thin leaf bodies such as laminates thereof Etc. In order to improve the peelability from the pressure-sensitive adhesive layer, the surface of the release sheet may be subjected to a low-adhesive release treatment such as silicone treatment, long-chain alkyl treatment, and fluorine treatment as necessary.

[Second adhesive layer]
The said polarizer (P) and the adhesive layer (B) are laminated | stacked by the 2nd adhesive bond layer (G2). As the adhesive (G2 ′) that forms the second adhesive layer (G2), for example, a polyvinyl alcohol-based adhesive, an isocyanate-based adhesive, a cyanoacrylate-based adhesive, or an aziridine-based adhesive is used.

  As a polyvinyl alcohol-type adhesive agent, the thing similar to what was demonstrated in said 1st adhesive bond layer (G1) can be used.

  Examples of the isocyanate-based adhesive include those used as a crosslinking agent in the formation of the pressure-sensitive adhesive layer (B). As the isocyanate-based crosslinking agent, a compound having at least two isocyanate groups can be used. For example, the polyisocyanate compound can be used as an isocyanate-based crosslinking agent. Specifically, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, 1,3-bisisocyanatomethylcyclohexane, hexamethylene diisocyanate, tetramethylxylylene diisocyanate, m-isopropenyl-α, α-dimethylbenzyl isocyanate, methylene bis 4-phenyl isocyanate, p-phenylene diisocyanate or dimers thereof, trimers such as isocyanuric acid tris (6-inocyanate hexyl), and also biuret and trimethylolpropane Examples include those reacted with polyhydric alcohols and polyhydric amines. Moreover, as an isocyanate type crosslinking agent, what has 3 or more isocyanate groups, such as isocyanuric acid tris (6-inocyanate hexyl), is preferable.

  In addition, the said isocyanate type crosslinking agent can also use what provided the protective group to the terminal isocyanate group. Protecting groups include oximes and lactams. In the case where the isocyanate group is protected, the protecting group is dissociated from the isocyanate group by heating, and the isocyanate group reacts.

  Further, a reaction catalyst can be used to increase the reactivity of the isocyanate group. The reaction catalyst is not particularly limited, but a tin-based catalyst or an amine-based catalyst is suitable. The reaction catalyst can use 1 type (s) or 2 or more types. The amount of the reaction catalyst used is usually 5 parts by weight or less with respect to 100 parts by weight of the isocyanate-based crosslinking agent. When the amount of the reaction catalyst is large, the crosslinking reaction rate increases and foaming of the adhesive occurs. Even if an adhesive after foaming is used, sufficient adhesion cannot be obtained. Usually, when using a reaction catalyst, 0.01-5 weight part, Furthermore, 0.05-4 weight part is preferable.

  As the tin-based catalyst, both inorganic and organic catalysts can be used, but an organic catalyst is preferable. Examples of the inorganic tin-based catalyst include stannous chloride and stannic chloride. The organic tin-based catalyst is preferably one having at least one organic group such as an aliphatic group or alicyclic group having a skeleton such as a methyl group, an ethyl group, an ether group or an ester group. For example, tetra-n-butyltin, tri-n-butyltin acetate, n-butyltin trichloride, trimethyltin hydroxide, dimethyltin dichloride, dibutyltin dilaurate and the like can be mentioned.

  The amine catalyst is not particularly limited. For example, those having at least one organic group such as an alicyclic group such as quinoclidine, amidine, diazabicycloundecene are preferable. In addition, examples of the amine catalyst include triethylamine. Examples of reaction catalysts other than the above include cobalt naphthenate and benzyltrimethylammonium hydroxide.

  The isocyanate adhesive is usually used as a solution. The solution may be a solvent system or an aqueous system such as an emulsion, a colloidal dispersion, or an aqueous solution. The organic solvent is not particularly limited as long as the components constituting the adhesive are uniformly dissolved. Examples of the organic solvent include toluene, methyl ethyl ketone, ethyl acetate and the like. In addition, also when using it as an aqueous system, alcohols, such as n-butyl alcohol and isopropyl alcohol, and ketones, such as acetone, can also be mix | blended, for example. In the case of using an aqueous system, a dispersant is used, or an isocyanate-based crosslinking agent, a functional group having low reactivity with an isocyanate group such as a carboxylate, a sulfonate, or a quaternary ammonium salt, or an aqueous dispersion such as polyethylene glycol. It can carry out by introduce | transducing a sex component.

  Examples of the cyanoacrylate adhesive include alkyl-α-cyanoacrylates such as methyl-α-cyanoacrylate, ethyl-α-cyanoacrylate, butyl-α-cyanoacrylate, octyl-α-cyanoacrylate, and cyclohexyl-α-cyanoacrylate. And methoxy-α-cyanoacrylate.

  Examples of the aziridine-based adhesive include those used as a crosslinking agent in the formation of the pressure-sensitive adhesive layer (B). An aziridine-based crosslinking agent is a compound having two or more aziridine ring structures in the molecule. Examples of such aziridine-based crosslinking agents include diphenylmethane-4,4′-bis (1-aziridinecarboxamide), trimethylolpropane tri-β-aziridinylpropionate, and tetramethylolmethanetri-β-aziridini. Lupropionate, toluene-2,4-bis (1-aziridinecarboxamide), triethylenemelamine, bisisophthaloyl-1- (2-methylaziridine), tris-1- (2-methylaziridine) phosphine, and And trimethylolpropane tri-β- (2-methylaziridine) propionate. In addition, 1,1 '-(methylene-di-p-phenylene) bis-3,3-aziridylurea, 1,1'-(hexamethylene) bis-3,3-aziridylurea, 2,4,6-triaziridinyl -1,3,5-triazine, trimethylolpropane-tris- (2-aziridinylpropionate), N, N-hexamethylene-1,6-bis (1-aziridinecarboxamide), 2,2 And aziridine compounds such as -bishydroxymethylbutanol-tris (3- (1-aziridinyl) propionate). The aziridine adhesive can be used in the same usage manner as the isocyanate adhesive.

  The adhesive (G2 ′) 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, and a hydrolysis stabilizer. A stabilizer such as can also be blended. These stabilizers and the like can be blended in the adhesive (G1 ′) as well.

  The polarizer (P) and the pressure-sensitive adhesive layer (B) are in a state where the second adhesive layer (G2) has not solidified the adhesive (G2 ′) that forms the second adhesive layer (G2). It is formed by solidifying after applying them together. The adhesive (G2 ′) is used for bonding the polarizer (P) and the pressure-sensitive adhesive layer (B) before solidification, so that the functional group in the adhesive, the polarizer (P) and the pressure-sensitive adhesive are used. It is considered that the reaction with the functional group of the layer (B) was efficiently performed and the adhesion between the polarizer (P) and the pressure-sensitive adhesive layer (B) was improved.

  When the polarizer (P) and the pressure-sensitive adhesive layer (B) are bonded together, the pressure-sensitive adhesive layer (B) usually used is provided on the release sheet. The adhesive (G2 ′) forming the second adhesive layer (G2) may be supplied to either the polarizer (P) or the pressure-sensitive adhesive layer (B), or may be supplied to both. Further, the adhesive may be supplied to the bonding surface of the polarizer (P) and the pressure-sensitive adhesive layer (B), and the supply method is not particularly limited. Examples of the method for supplying the adhesive (G2 ′) include a dropping method, a coating method, and a spraying method. For these supply methods, nozzles, sprays, coaters, dies and the like are appropriately selected and used. In supplying the adhesive, the viscosity of the adhesive (G2 ′) can be adjusted according to the type of the adhesive so that the supply can be easily performed. The viscosity can be adjusted by dissolving or diluting the adhesive with water or an organic solvent.

  The adhesive (G2 ′) has a thickness of the second adhesive layer (G2) after solidification of about 0.01 to 5 μm, preferably 0.05 to 3 μm, more preferably 0.1 to 1 μm. Do as follows. The thickness of the second adhesive layer (G2) is preferably adjusted to the above range from the viewpoint of uniformly forming a coating film and affecting the optical properties.

  The polarizer (P) and the pressure-sensitive adhesive layer (B) are bonded together promptly from the supply of the adhesive (G2 ′) so that the adhesive (G2 ′) does not solidify. Usually, it is preferable to perform the bonding within 5 seconds, further within 2 seconds, further within 1 second, and further within 0.5 seconds from the supply of the adhesive (G2 ′). If the time until the bonding is too long, the adhesive may be solidified.

  After the polarizer (P) and the pressure-sensitive adhesive layer (B) are bonded together with the adhesive (G2 ′), the adhesive is solidified to form the second adhesive layer (G2). The means for solidifying the adhesive (G2 ′) can be appropriately selected according to the type of the adhesive, but is usually about 30 to 100 ° C., preferably 50 to 80 ° C., for 0.5 to 15 minutes. Perform by drying to a certain extent.

  The bonding and solidification of the polarizer (P) and the pressure-sensitive adhesive layer (B) with the adhesive (G2 ′) are preferably performed continuously. Moreover, it is preferable to also perform continuously the bonding by the 1st adhesive bond layer (G1) of the said polarizer (P) and a transparent protective film (E). Moreover, the said bonding can also be performed continuously from manufacture of a polarizer.

  The case where the manufacturing method of the adhesion type polarizing plate of this invention is manufactured continuously is demonstrated referring FIG. 2A and B below. 2A and 2B, a method of supplying the adhesive (G1 ′) is described for forming the first adhesive layer (G1). However, the first adhesive layer (G1) is transparent in advance. What was formed in the protective film (E) may be bonded to the polarizer (P). Moreover, in FIG. 2A and B, although only the adhesive layer (B) is described and description of the release sheet is omitted, the adhesive layer (B) is usually provided on the release sheet. Are used so that the release sheet side is the roll side.

  In FIG. 2A, adhesive (G1 ′) is supplied to one surface of the polarizer (P) and the bonding surface of the transparent protective film (E), and these are bonded by passing between the first rolls (R1). After matching, the adhesive (G2 ′) is supplied to the other surface of the polarizer (P) and the bonding surface of the pressure-sensitive adhesive layer (B), and these are passed between the second rolls (R2). In this case, the first adhesive layer (G1) and the second adhesive layer (G2) are formed by bonding. On the other hand, FIG. 2B shows that the adhesive (G1 ′) is supplied to one surface of the polarizer (P) and the bonding surface of the transparent protective film (E), and the other surface of the polarizer (P) and the adhesive layer ( The adhesive (G2 ′) is supplied to the bonding surface of B), and these are simultaneously bonded by passing between the first rolls (R1), and the first adhesive layer (G1) and the second adhesive are bonded. This is a case where the agent layer (G2) is formed. According to the embodiment of FIG. 2, the first adhesive layer (G1) and the second adhesive layer (G2) can be formed simultaneously, which is efficient.

  The roll is not particularly limited as long as the polarizer (P) and the transparent protective film (E) or the pressure-sensitive adhesive layer (B) can be bonded by roll pressure when passing through the pair of rolls. There is no. For example, a laminate nip roll is used. The material of the roll is not particularly limited, and may be made of rubber or metal.

  The transport speed of the polarizer (P) and the transparent protective film (E) or the pressure-sensitive adhesive layer (B) is not particularly limited, but is usually about 0.03 to 1.0 m / s, preferably 0.08 to 0.8 m. / S, and more preferably about 0.11 to 0.6 m / s.

  The supply amount of the adhesive (G1 ′) or the adhesive (G2 ′) is appropriately determined in consideration of the thickness, transport speed, film width, etc. of the first adhesive layer (G1) or the second adhesive layer (G2). Adjusted to

  2A and 2B, the adhesive (G1 ′) or the adhesive (G2 ′) is supplied to the bonding surface of the polarizer (P) and the transparent protective film (E) or the pressure-sensitive adhesive layer (B). However, the supply location of the adhesive (G1 ′) or the adhesive (G2 ′) can be changed to the polarizer (P), the transparent protective film (E) or the pressure-sensitive adhesive layer (B) before bonding. . Further, a plurality of supply points of the adhesive (G1 ′) or the adhesive (G2 ′) can be provided.

[Other optical layers]
(Formation of surface treatment layer)
In the pressure-sensitive adhesive polarizing plate of the present invention, an optional optical layer can be added to the transparent protective film (E) on the side where the polarizer (P) is not bonded to the first adhesive layer (G1). As such an optical layer, a hard coat layer, an antireflection treatment, an anti-sticking treatment, or a treatment subjected to treatment for diffusion or anti-glare can be used.

  The hard coat treatment is performed for the purpose of preventing scratches on the surface of the polarizing plate. For example, the above-mentioned transparent protective film is cured with excellent hardness and sliding properties by an appropriate UV curable resin such as acrylic or silicone. It can form by the system etc. which are added to the surface of a film (E). The antireflection treatment is performed for the purpose of preventing the reflection of external light on the surface of the polarizing plate, and can be achieved by forming an antireflection film or the like according to the prior art. In addition, the sticking prevention treatment is performed for the purpose of preventing adhesion with an adjacent layer (for example, a backlight-side diffusion plate).

  The anti-glare treatment is applied for the purpose of preventing the outside light from being reflected on the surface of the polarizing plate and obstructing the visibility of the light transmitted through the polarizing plate. For example, the surface is roughened by a sandblasting method or an embossing method. It can be formed by imparting a fine concavo-convex structure to the surface of the transparent protective film (E) by an appropriate method such as a compounding method of transparent fine particles. The fine particles to be included in the formation of the surface fine concavo-convex structure are, for example, conductive materials made of silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide or the like having an average particle diameter of 0.5 to 20 μm. In some cases, transparent fine particles such as inorganic fine particles, organic fine particles composed of a crosslinked or uncrosslinked polymer, and the like are used. When forming the surface fine uneven structure, the amount of fine particles used is generally about 2 to 70 parts by weight, preferably 5 to 50 parts by weight, based on 100 parts by weight of the transparent resin forming the surface fine uneven structure. The antiglare layer may also serve as a diffusion layer (viewing angle expanding function or the like) for diffusing the light transmitted through the polarizing plate to expand the viewing angle or the like.

  The antireflection layer, the antisticking layer, the diffusion layer, the antiglare layer, and the like can be provided on the transparent protective film (E), or can be provided separately as separate optical layers.

  In addition, examples of the optical layer that can be applied to the polarizing plate of the present invention include a brightness enhancement film, a reflective layer, a retardation plate, and the like.

(Brightness enhancement film)
The brightness enhancement film reflects the linearly polarized light with a predetermined polarization axis or the circularly polarized light in a predetermined direction when natural light is incident due to a backlight of a liquid crystal display device or the like or reflection from the back side, and transmits other light. In the case where a brightness enhancement film is laminated with a polarizing plate, light from a light source such as a backlight is incident to obtain transmitted light in a predetermined polarization state, and light other than the predetermined polarization state is reflected without being transmitted. . The light reflected by the brightness enhancement film is further inverted through a reflective layer provided behind the brightness enhancement film and re-incident on the brightness enhancement film, and part or all of the light is transmitted as light in a predetermined polarization state to improve brightness. Luminance can be improved by increasing the amount of light transmitted through the film and increasing the amount of light that can be used for image display such as liquid crystal display by supplying polarized light that is difficult to absorb to the polarizer. A polarizing plate obtained by bonding a polarizing plate and a brightness enhancement film is often used by being provided on the backlight side of a liquid crystal cell. However, as disclosed in WO 2006/038404, an international pamphlet is used. It can also be provided on the viewing side.

  As a brightness enhancement film, for example, a multi-layer thin film of dielectric material or a multi-layer laminate of thin film films having different refractive index anisotropy, which shows a characteristic of transmitting linearly polarized light with a predetermined polarization axis and reflecting other light Such as a cholesteric liquid crystal polymer alignment film or a film substrate having the alignment liquid crystal layer supported on a film substrate, which reflects either left-handed or right-handed circularly polarized light and transmits other light, etc. Any appropriate one can be used.

(Reflective layer)
By providing a reflective layer on the polarizing plate of the present invention, a reflective polarizing plate can be obtained. The reflective polarizing plate is used to form a liquid crystal display device or the like that reflects incident light from the viewing side (display side) on the polarizing plate, and can eliminate the incorporation of a light source such as a backlight. Thus, the liquid crystal display device can be easily thinned. The reflective polarizing plate can be formed by an appropriate method such as a method in which a reflective layer made of metal or the like is provided on one surface of the polarizing plate via the transparent protective film (E) as necessary.

  The semi-transmissive polarizing plate can be obtained by using a semi-transmissive reflective layer such as a half mirror that reflects and transmits light with the reflective layer. A transflective polarizing plate is usually provided on the back side (backlight side) of a liquid crystal cell, and reflects incident light from the viewing side (display side) when a liquid crystal display device is used in a relatively bright atmosphere. In a relatively dark atmosphere, a liquid crystal display device of a type that displays an image using a built-in light source such as a backlight built in the back side of the transflective polarizing plate can be formed. In other words, the transflective polarizing plate is useful for forming a liquid crystal display device of a type that can save the energy of using a light source such as a backlight in a bright atmosphere and can be used with a built-in light source even in a relatively dark atmosphere. It is.

[Phase difference plate]
As the retardation plate, a birefringent film obtained by uniaxially or biaxially stretching a polymer material, a liquid crystal polymer alignment film, a liquid crystal polymer alignment layer supported by a film, or the like described above may be used. Can do.

  As an example of the laminated polarizing plate in which the retardation plate is laminated on the polarizing plate, an elliptically polarizing plate or a circularly polarizing plate will be described. A phase difference plate or the like is used when changing linearly polarized light to elliptically polarized light or circularly polarized light, changing elliptically polarized light or circularly polarized light to linearly polarized light, or changing the polarization direction of linearly polarized light. In particular, a so-called quarter-wave plate (also referred to as a λ / 4 plate) is used as a retardation plate that changes linearly polarized light into circularly polarized light or changes circularly polarized light into linearly polarized light. A half-wave plate (also referred to as a λ / 2 plate) is usually used when changing the polarization direction of linearly polarized light.

  The elliptically polarizing plate is effectively used to compensate (prevent) the coloration (blue or yellow) caused by the birefringence of the liquid crystal layer of the super twist nematic (STN) type liquid crystal display device, and to display black and white without the color. It is done. Further, the one in which the three-dimensional refractive index is controlled is preferable because it can compensate (prevent) coloring that occurs when the screen of the liquid crystal display device is viewed from an oblique direction. The circularly polarizing plate is effectively used, for example, when adjusting the color tone of an image of a reflective liquid crystal display device in which the image is displayed in color, and also has an antireflection function.

  The elliptically polarizing plate and the reflective elliptically polarizing plate are obtained by laminating a polarizing plate or a reflective linearly polarizing plate and a retardation plate in an appropriate combination. Such an elliptically polarizing plate or the like can also be formed by sequentially laminating them sequentially in the manufacturing process of the liquid crystal display device so as to be a combination of a (reflection type) polarizing plate and a retardation plate. An optical compensation polarizing plate such as a polarizing plate has an advantage that it can improve the production efficiency of a liquid crystal display device and the like because of excellent quality stability and lamination workability.

  The viewing angle compensation film is a film for widening the viewing angle so that an image can be seen relatively clearly even when the screen of the liquid crystal display device is viewed from a slightly oblique direction rather than perpendicular to the screen. As such a viewing angle compensation phase difference plate, for example, a phase difference plate, an alignment film such as a liquid crystal polymer, or an alignment layer such as a liquid crystal polymer supported on a transparent base material is used. A normal retardation plate uses a birefringent polymer film uniaxially stretched in the plane direction, whereas a retardation plate used as a viewing angle compensation film stretches biaxially in the plane direction. Birefringent polymer film, biaxially stretched film such as a polymer having a birefringence with a controlled refractive index in the thickness direction that is uniaxially stretched in the plane direction and stretched in the thickness direction, and a tilted orientation film Used. Examples of the inclined alignment film include a film obtained by bonding a heat shrink film to a polymer film and stretching or / and shrinking the polymer film under the action of the contraction force by heating, or a film obtained by obliquely aligning a liquid crystal polymer. Can be mentioned. The raw material polymer of the phase difference plate is the same as the polymer described in the previous phase difference plate, preventing coloration due to a change in the viewing angle based on the phase difference by the liquid crystal cell, expanding the viewing angle for good visual recognition, etc. An appropriate one for the purpose can be used.

[Lamination of optical layer]
Optical layers such as a brightness enhancement film, a reflective layer, and a retardation plate can be formed by sequentially laminating them sequentially in the manufacturing process of a liquid crystal display device, etc. Further, there is an advantage that the manufacturing process of the liquid crystal display device and the like can be improved because of excellent quality stability and assembly work. For the lamination, an appropriate adhesive means such as an adhesive layer can be used. In these laminations, the optical axis (the slow axis of the retardation film, the absorption axis of the polarizer, etc.) of each optical layer can be set to an appropriate arrangement angle according to the target retardation characteristics and the like.

(Adhesive layer)
An adhesive layer may be provided on each optical layer. The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is not particularly limited. For example, an acrylic polymer, silicone-based polymer, polyester, polyurethane, polyamide, polyether, fluorine-based or rubber-based polymer is appropriately selected. Can be used. In particular, those having excellent optical transparency, such as an acrylic pressure-sensitive adhesive, exhibiting appropriate wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties, and having excellent weather resistance, heat resistance and the like can be preferably used.

  In addition to the above, from the viewpoints of prevention of foaming and peeling phenomenon due to moisture absorption, deterioration of optical characteristics due to thermal expansion difference and the like, prevention of warpage of liquid crystal cells, and formation of liquid crystal display devices with high quality and excellent durability. An adhesive layer having a low moisture absorption rate and excellent heat resistance is preferred.

  In the present invention, each of the polarizer, the transparent protective film and other optical layers, the adhesive, the adhesive layer and the like forming the above-mentioned adhesive-type polarizing plate is, for example, a salicylic acid ester compound, a benzophenol compound, or a benzotriazole. It may be one having a UV-absorbing ability by a method such as a method of treating with a UV absorber such as a compound, a cyanoacrylate compound or a nickel complex salt compound.

[Image display device]
The pressure-sensitive adhesive polarizing plate of the present invention can be preferably used for forming an image display device such as a liquid crystal display device or an organic EL display device.

(Liquid crystal display device)
The liquid crystal display device can be formed according to the conventional method. That is, the liquid crystal display device generally has a liquid crystal cell, a polarizing plate, and, if necessary, appropriate elements such as a diffusion plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffusion plate, a backlight, and the like. It is formed by arranging one or more parts at appropriate positions and incorporating a drive circuit. The formation of the liquid crystal display device is not particularly limited except that the pressure-sensitive adhesive polarizing plate according to the present invention is used, and can be based on the conventional one. As the liquid crystal cell, any type of liquid crystal cell such as a TN type, STN type, or π type can be used.

  The pressure-sensitive adhesive polarizing plate of the present invention can be installed on one side or both sides of a liquid crystal cell. When providing an adhesive polarizing plate on both sides, they may be the same or different.

[Method for forming liquid crystal display device]
[Conventional Method for Forming Liquid Crystal Display]
By the way, in forming an image display device such as a liquid crystal display device or an organic EL display device, a transparent protective film (E) is laminated only on one side of the polarizer (P) like the pressure-sensitive adhesive polarizing plate of the present invention. In the case of a structure, the stress provided to the film interface of a polarizer (P) may differ in the main surface by which the transparent protective film (E) is laminated | stacked, and the other main surface. That is, since the layer structure is different between the front and back of the polarizer (P), the external stress applied to the polarizer may be different between the front and back of the film. Due to this difference in external stress, the film tends to have a curvature. Such a film that is easily bent is difficult to be processed into an image display device in the conventional manufacturing process as described below.

  As shown conceptually in FIG. 3, the conventional manufacturing process of an image device is roughly divided into a manufacturing process in an optical film manufacturer and a manufacturing process in a panel processing manufacturer. First, an optical film manufacturer manufactures an optical film such as a polarizing plate as a roll of a long (band-shaped) sheet product (# 1). Next, the original roll is slit to a predetermined size (a size according to the size of the optical display unit) (# 2). Next, the slit raw material is cut to a fixed length in accordance with the size of the optical display unit to be bonded, such as a liquid crystal cell or an organic EL panel (# 3). Next, an appearance inspection is performed on the sheet-shaped product (optical film) that has been cut into pieces (# 4). Examples of the inspection method include visual defect inspection and inspection using a known defect inspection apparatus. The defect means, for example, surface or internal dirt, scratches, a dent-like defect including a foreign object, an uneven defect, a bubble, a foreign object, or the like. Next, the finished product is inspected (# 5). The finished product inspection is an inspection that complies with quality standards that are more stringent than the appearance inspection. Next, the end surfaces of the four end surfaces of the sheet-like product are processed (# 6). This is performed to prevent the adhesive or the like from protruding from the end face during transportation. Next, in a clean room environment, the single sheet product is clean-wrapped (# 7). Next, packaging for transportation (transport packaging) (# 8). A sheet-like product is manufactured as described above and transported to a panel processing manufacturer.

  The panel processing manufacturer unpacks and disassembles the sheet-like product that has been transported (# 11). Next, an appearance inspection is performed in order to inspect for scratches, dirt, etc. that occur during transportation or at the time of unpacking (# 12). The sheet-like product that has been determined to be non-defective in the inspection is conveyed to the next process. Note that this appearance inspection may be omitted. An optical display unit (for example, a liquid crystal cell that is a glass substrate unit in which a liquid crystal cell is sealed) to which a sheet-like product is bonded is manufactured in advance, and the optical display unit is washed before the bonding step ( # 13).

  Next, the single sheet product and the optical display unit (liquid crystal cell) are bonded together (# 14). The release film is peeled off from the sheet-like product leaving a pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer is bonded to one surface of the optical display unit as a bonding surface. Further, it can be similarly bonded to the other surface of the optical display unit. In the case of bonding to both, an optical film having the same configuration may be bonded to each surface of the optical display unit, or an optical film having a different configuration may be bonded to each other. Next, the bonded state and defect inspection are performed (# 15). The optical display unit determined to be non-defective in this inspection is transported to the mounting process and mounted on the image display device (# 16). On the other hand, the optical display unit determined to be defective is subjected to a rework process (# 17). In the rework process, the optical film is peeled from the optical display unit. An optical film is newly bonded to the reworked optical display unit (# 14).

  When the conventional manufacturing process as described above is applied to a film that is easily bent, a polarizing plate is present in a roll shape (# 1), (# 2), and is stretched between transport lines. Therefore, the bending behavior is suppressed by the tension. However, when this is cut to a regular length (# 3), the tension that suppresses the bending behavior of the polarizing plate is released, so that bending occurs, and the appearance inspection (# 4) to bonding with the liquid crystal cell (# 14) ) Is difficult to handle. Furthermore, in the case of the conventional manufacturing process, in addition to the above-mentioned problem of handling due to the curvature, there is a problem that the manufacturing cost increases because it is a multi-process such as inspection and packing.

[Continuous manufacturing method]
The film formed in such a long roll shape is continuously bonded to the liquid crystal cell while being fed out in the presence of tension, so that the bending can be suppressed and this problem can be solved. In other words, by performing continuous cutting (# 3) and bonding to a liquid crystal cell (# 14), which were conventionally performed separately by an optical film manufacturer and a panel processing manufacturer, in one place, an appearance inspection (# 4). Finished product inspection (# 5), end face processing (# 6), clean packaging (# 7) transport packaging (# 8), packaging dismantling (# 11), appearance inspection (# 12) are not required, and curved The problem of handling due to can be solved.

  Formation of such an image display device by a continuous method uses a roll original fabric preparation step in which the long sheet of the polarizing plate of the present invention is prepared as a roll original fabric, a sheet product is fed out from the roll original fabric, and a cutting means is used. A cutting step of cutting the polarizing plate into a predetermined size, and a bonding step of bonding the polarizing plate to the optical display unit via the adhesive layer after the cutting step. One example is shown below.

[Embodiment 1 by continuous method (normal cutting method)]
(1) 1st roll original fabric preparation process (FIG. 4, S1)
The polarizing plate of the present invention formed into a long shape is prepared as a first roll raw material. This polarizing plate has a first optical film 11 in which a transparent protective film (E) and a polarizer (P) are laminated, a first adhesive layer 14, and a first release film 12. The first optical film 11 may include an optical layer other than the transparent protective film and the polarizer. The first optical film 11 has a first adhesive layer 14 and a first release film 12 on the surface of the first optical film 11 on the polarizer (P) side.

(2) First cutting step (FIG. 4, S2)
Next, the first sheet product is fed out from the first roll prepared and installed, and the first optical film 11 and the first pressure-sensitive adhesive layer without cutting the first release film 12 using a cutting means. 14 is cut into a predetermined size. Thereby, the 1st optical film 11 and the 1st adhesive layer 14 can be cut | disconnected, without cut | disconnecting the 1st release film 12. FIG. Therefore, since the first optical film 11 is still formed on the first release film 12 via the first pressure-sensitive adhesive layer 14, the first optical film 11 is not curved. Examples of the cutting means include a laser device, a cutter, and other known cutting means.

(3) 1st optical film bonding process (FIG. 4, S3)
Next, after the first cutting step, the first optical film 11 from which the first release film 12 has been removed is removed through the first pressure-sensitive adhesive layer 14 while removing the first release film 12. Affix to A. Therefore, even if the 1st release film 12 is peeled, the 1st optical film 11 can be bonded together to the optical display unit A in the state by which the curvature of the 1st optical film 11 was suppressed. Examples of the optical display unit A include a glass substrate unit of a liquid crystal cell and an organic EL light emitting unit. In addition, the optical display unit A is cleaned in advance before bonding.

  Each process of these 1st roll original fabric preparation processes, the 1st cutting process, and the 1st optical film pasting process is performed with the continuous production line. In the series of manufacturing steps described above, the first optical film 11 is bonded to one surface of the optical display unit A. Below, the manufacturing process which bonds the 2nd optical film 21 on another surface is demonstrated.

(4) Second roll stock preparation step (FIG. 4, S4)
A long second sheet product 2 is prepared as a second roll material. The laminated structure of the second sheet product 2 includes a second optical film 21, a second adhesive layer 24, and a second release film 22, as in the case of the first optical film. In addition, as an 2nd optical film, although arbitrary optical films can be used, it is preferable that it is a polarizing plate containing a polarizer.

(5) Second cutting step (FIG. 4, S5)
Subsequently, the second sheet product is fed out from the prepared second roll raw material, and the second optical film 21 and the second optical film 21 are cut without cutting the second release film 22 as in the case of the first optical film. 2 The adhesive layer 24 is cut into a predetermined size.

(6) 2nd optical film bonding process (FIG. 4, S6)
Next, after the second cutting step, while removing the second release film 22, the second optical film 21 from which the second release film 22 has been removed is optically coupled via the second pressure-sensitive adhesive layer 24. The first optical film 11 of the display unit A is bonded to a surface different from the surface to which the first optical film 11 is bonded. Therefore, even if it peels off the 2nd release film 22, the 2nd optical film 21 can be bonded together to the optical display unit A in the state by which the curve of the 2nd optical film 21 was suppressed. Thus, an optical display unit in which the first optical film 11 is bonded to one surface of the optical display unit A, the second optical film 21 is bonded to the other surface, and the optical films are provided on both surfaces can be manufactured.

  And each process of the 1st roll original fabric preparation process, the 1st cutting process, the 1st optical film pasting process, the 2nd roll original fabric preparation process, the 2nd cutting process, and the 2nd optical film pasting process was continued. Run on the production line.

(7) Inspection process Furthermore, it is preferable to have an inspection process (FIG. 4, S7) as a continuous process. Examples of the inspection process include an inspection process for inspecting the bonding state and an inspection process for inspecting defects after bonding, but only one of the inspections may be performed, but it is preferable to perform both inspections.

(8) Mounting process In the inspection process, the optical display unit A determined to be non-defective is mounted on an image display device. If a defective product is determined, a rework process is performed, a new optical film is applied, and then inspected.If a good product is determined, the process proceeds to a mounting process. Dispose of.

  In the embodiment described above, the polarizing plate of the present invention is used as the first optical film 11, but the polarizing plate of the present invention can also be used as the second optical film 21. Further, the polarizing plate of the present invention can be used for both the first optical film 11 and the second optical film 21.

[Embodiment 2 by Skip Method (Skip Cut Method)]
Next, an embodiment of cutting by the skip cut method, in which the embodiments of the first cutting step and the second cutting step in the embodiment of cutting by the above-described normal method are modified, will be described.

  At one end in the width direction of the first and second rolls, defect information (defect coordinates, defect type, size, etc.) of the first and second sheet products is provided in a predetermined pitch unit (for example, 1000 mm). It may be attached as code information (for example, QR code, barcode). In such a case, the code information is read and analyzed at a stage prior to cutting, and cut into a predetermined size in the first and second cutting steps (sometimes referred to as skip cut) so as to avoid the defective portion. Then, the defective part is configured to be removed or bonded to a member that is not an optical display unit, and a non-defective sheet-shaped product cut into a predetermined size is configured to be bonded to the optical display unit. . As a result, the yield of the optical display unit can be greatly improved, and the frequency with which the rework process (# 17) is required can be reduced. FIG. 5 shows a flowchart of a manufacturing method of an image display device to which this cutting method (skip cut method) is applied.

(1) 1st roll original fabric preparation process (FIG. 5, S1)
As in the case of the normal cutting method, the polarizing plate of the present invention including the first adhesive layer 14 and the first release film 12 is prepared as a first roll raw fabric.

(2) First release film removal step (FIG. 5, S61)
Next, the first sheet product is fed out from the first roll prepared and installed, and the first release film 12 is removed. As a method for removing the first release film 12, for example, a method in which the peeled film is continuously wound around a roll, or only the first release film is cut into a predetermined size unit and peeled off with an adhesive tape. And removal methods of other methods.

(3) First defect inspection process (FIG. 5, S62)
Next, after the first release film removing step, defect inspection is performed. The defect inspection of the first optical film 11 can be performed without the need to consider defects such as foreign matter and scratches attached to or existing in the first release film 12, or the phase difference inherent in the first release film. A known method can be applied to the defect inspection.

(4) 2nd release film bonding process (FIG. 5, S63)
Next, the second release film 12 a is bonded to the first optical film 11 via the first adhesive layer 14 on the first defect inspection process trace. In order to maintain flatness, it is preferable to perform the bonding so that bubbles such as bubbles do not occur.

(5) First cutting step (FIG. 5, S64)
Next, after the second release film bonding step, the first optical film 11 and the first pressure-sensitive adhesive layer 14 are cut into a predetermined size without cutting the second release film 12a using a cutting means. Thereby, the 1st optical film 11 and the 1st adhesive layer 14 can be cut | disconnected, without cut | disconnecting the 2nd release film 12a. Therefore, since the first optical film 11 remains formed on the second release film 12a via the first pressure-sensitive adhesive layer 14, the first optical film 11 is not curved. Examples of the cutting means include a laser device, a cutter, and other known cutting means.

(6) 1st optical film bonding process (FIG. 5, S65)
Next, the first optical film 11 is bonded to the optical display unit A while removing the second release film 12a as in the case of the normal cutting method.

  Each process of these 1st roll original fabric preparation processes, the 1st mold release film removal process, the 1st fault inspection process, the 2nd mold release film pasting process, the 1st cutting process, and the 1st optical film pasting process is Performed on a continuous production line. In the series of manufacturing steps described above, the first optical film 11 is bonded to one surface of the optical display unit A.

(7) Second roll original fabric preparation step (FIG. 5, S4)
A long second sheet product 2 is prepared as a second roll material. The laminated structure of the second sheet product 2 includes a second optical film 21, a third release film 22, and a surface protective film 23, as in the case of the first optical film.

(8) Third release film removing step (FIG. 5, S66)
Next, the second sheet material is fed out from the prepared second roll raw material, and the third release film 22 is removed in the same manner as the first optical film.

(9) Second defect inspection process (FIG. 5, S67)
Next, after the third release film removing step, defect inspection is performed in the same manner as in the case of the first optical film.

(10) Fourth release film bonding step (FIG. 5, S68)
Next, after the second defect inspection step, the fourth release film 22 a is bonded to the second optical film 21 through the second pressure-sensitive adhesive layer 24 in the same manner as in the case of the first optical film.

(11) Second cutting step (FIG. 5, S69)
Next, after the fourth release film laminating step, the second optical film 21 and the second optical film 21a and the second optical film 21a are cut without using the cutting means to cut the fourth release film 22a in the same manner as the first optical film. 2 The adhesive layer 24 is cut into a predetermined size.

(12) 2nd optical film bonding process (FIG. 5, S70)
Then, after the second cutting step, the second optical film 21 from which the fourth release film 22a has been removed while removing the fourth release film 22a in the same manner as in the case of the normal cutting method, The second adhesive layer 24 is bonded to a surface different from the surface to which the first optical film 11 of the optical display unit A is bonded.

  And the 1st roll original fabric preparation process, the 1st mold release film removal process, the 1st fault inspection process, the 2nd mold release film pasting process, the 1st cutting process, the 1st optical film pasting process, the 2nd roll original The anti-preparation process, the third release film removal process, the second defect inspection process, the fourth release film bonding process, the second cutting process, and the second optical film bonding process are performed on a continuous production line. To do.

(13) Inspection process Furthermore, it is preferable to have an inspection process (FIG. 5, S7) as a continuous process similarly to the case of the said normal cutting system.

(14) Mounting process In the inspection process, the optical display unit A determined to be non-defective is mounted on an image display device. If a defective product is determined, a rework process is performed, a new optical film is applied, and then inspected.If a good product is determined, the process proceeds to a mounting process. Dispose of.

[Manufacturing system suitable for manufacturing image display device by continuous method]
6A and 6B show a schematic configuration of a manufacturing system for an example of an embodiment that realizes the first embodiment (manufacturing method including a cutting process using a skip cut method).

  As shown in FIGS. 6A and 6B, the manufacturing system attaches the second optical member to a surface different from the substrate surface to which the first optical member is bonded, and the first manufacturing section that bonds the first optical member to the substrate. 2 production departments.

  The first manufacturing unit includes a first installation unit that installs the first roll raw material of the long first sheet product 1, and a first conveyance unit that feeds and conveys the first sheet product 1 from the first roll raw material. The first release film removing means for removing the first release film from the conveyed first sheet product 1, the first defect inspection means for inspecting the defect after the removal of the first release film, and the first defect After the inspection, after the second release film laminating means for laminating the second release film to the first sheet product 1 via the first adhesive and the second release film, the second release film The first cutting means for cutting the other members of the first sheet product 1 while leaving the film, and the other of the cut first sheet product 1 while removing the second release film after the first cutting process First bonding means for bonding the member to the substrate via the first adhesive, and And first control means for controlling these means to be interlocked.

  The second manufacturing unit includes a second installation unit that installs the second roll original of the long second sheet product 2, and a second conveyance unit that feeds and conveys the second sheet product 2 from the second roll original. , A third release film removing means for removing the third release film from the conveyed second sheet product 2, a second defect inspection means for inspecting defects after removing the third release film, and a second defect After the inspection, after the fourth release film is bonded to the second sheet product 2 via the second pressure-sensitive adhesive and the fourth release film are bonded, the fourth release film is bonded. The second cutting means for cutting the other members of the second sheet product 2 while leaving the film, and the other of the cut second sheet product 2 while removing the fourth release film after the second cutting process The first optical member of the substrate is bonded to the member through the second adhesive. A second bonding means for bonding to a surface different from the surface to be bonded, and a second control means for controlling the respective means to be interlocked.

  The first manufacturing unit and the second manufacturing unit may be driven independently, but may be driven so as to be interlocked with each other. The first control means and the second control means can be configured to drive and control a series of processing steps in conjunction with each other. In addition, in the manufacturing method by the normal system which does not employ | adopt skip cut like the said Embodiment 1, the structure by which the release film removal means, the defect inspection means, and the release film bonding means were abbreviate | omitted is employable. .

(First Production Department)
The first installation means 301 is configured by a roller mount device that is installed with a first roll of the long first sheet product 1 and is linked to a motor or the like so as to rotate freely or at a constant rotational speed. . The rotation speed is set by the first control means, and the drive is controlled.

  The 1st conveyance means 302 pays out the 1st sheet product 1 from the 1st roll original fabric, and conveys the 1st sheet product 1 to each processing process. Install tension controls at key points in each process. The first transport unit 302 is controlled by the first control unit 307.

  A 1st release film removal means is the structure which peels and removes a 1st release film from the conveyed 1st sheet | seat product 1, and winds up in roll shape. The winding speed on the roll is controlled by the first control means. As the peeling mechanism (see FIG. 6B), the tip has a sharp knife edge, and the first release film is wound around the knife edge and transferred in reverse, thereby peeling and removing the first release film, It is comprised so that the 1st sheet product 1 after peeling a 1st release film may be conveyed in a conveyance direction.

  The first defect inspection means 303 performs defect inspection after removing the first release film. The first defect inspection means 303 is a CCD camera or a CMOS camera, and the acquired image data is transmitted to the first control means. The first control means analyzes the image data, detects a defect, and calculates its position coordinates. The position coordinates of this defect are provided for the skip cut by the first cutting means described later.

  The second release film bonding means bonds the second release film to the first sheet product via the first adhesive after the first defect inspection. As shown in FIG. 6A, the second release film is unwound from the original roll of the second release film, and the second release film and the first sheet product are sandwiched by one or a plurality of roller pairs, and the roller pair Apply a predetermined pressure and stick together. The rotation speed, pressure control, and conveyance control of the roller pair are controlled by the first control means.

  The 1st cutting means 304 cuts the other member of the 1st sheet product 1, leaving the said 2nd mold release film, after bonding the 2nd mold release film. The first cutting means 304 is a laser device. Based on the position coordinates of the defect detected in the first defect inspection process, the first cutting means 304 cuts to a predetermined size so as to avoid the defect portion. That is, a cut product including a defective portion is excluded as a defective product in a subsequent process. Or the 1st cutting means 304 may ignore the presence of a fault and may cut continuously to a predetermined size. In this case, in the bonding process described later, the portion can be removed without bonding or bonded to the temporary plate unit. The control in this case also depends on the function of the first control means.

  The first cutting means 304 has a holding table for sucking and holding the first sheet product 1 from the back surface, and a laser device is provided above the first sheet product 1. Move horizontally so as to scan the laser in the width direction of the first sheet product 1, leave the second release film at the bottom, the surface protection film, the adhesive layer, the first optical member, the first adhesive Cut at a predetermined pitch in the transport direction. In addition, the laser device collects gas (smoke) generated from the air nozzle that blows warm air toward the cutting site and the cutting site conveyed by the hot air so as to be sandwiched from the width direction of the first sheet product 1. It is preferable that the smoke collecting duct that smokes is configured integrally. When the first sheet product 1 is sucked by the holding table, the step rollers 302a and 302b of the transport mechanism move in the vertical direction so as not to stop the continuous transport of the first sheet product 1 on the downstream side and the upstream side. It is configured as follows. This operation is also controlled by the first control means.

  A 1st bonding means affixes the other member of the 1st sheet product 1 cut | disconnected above on the board | substrate W through a 1st adhesive, removing a 2nd release film after a 1st cutting process. Match. As shown in FIG. 6B, when bonding, the first sheet product 1 is bonded to the substrate W surface by the pressing roller 305 and the guide roller 3051 while being pressed. The pressing pressure and operation of the pressing roller 305 are controlled by the first control means. The peeling mechanism has a knife edge N1 having a sharp tip, and the second release film H1 is wound around the knife edge N1 and transferred in reverse, thereby peeling and removing the second release film H1. It is comprised so that the 1st sheet product 1 after peeling the 2 release film H1 may be sent out to the board | substrate W surface. At this time, a state in which a tension of 150 N / m or more and 1000 N / m or less is applied to the second release film H1 and / or the first sheet product 1 on the substrate W surface after the second release film H1 is removed. By performing the time until pressure contact within 3 seconds, the bonding accuracy of the first sheet product 1 can be improved. If the tension is less than 150 N / m, the delivery position of the first sheet product 1 is not stable, and if it is more than 1000 N / m, the second release film H1 may stretch and break, and the time until press contact is 3 seconds. If it is longer, the end portion of the first sheet product 1 peeled off from the second release film H1 may be bent and folds or bubbles may be generated. The laminating mechanism includes a pressing roller 305 and a guide roller 3051 arranged to face the pressing roller 305. The guide roller 3051 is composed of a rubber roller driven by a motor, and a pressing roller 305 made of a metal roller driven by a motor is disposed directly above the guide roller 3051 so that the substrate W can be sent to a bonding position. The pressing roller 305 is raised to a position higher than its upper surface so as to open a roller interval. Note that both the guide roller 3051 and the pressing roller 305 may be rubber rollers or metal rollers. The substrate W is previously cleaned and stocked. The suction conveyance unit 306 is arranged in the conveyance mechanism. This control is also controlled by the first control means.

(Second manufacturing department)
In each step of the second manufacturing department, the second installation means, the second transport means, the third release film removing means, the second defect inspection means, the fourth release film laminating means, the second cutting means, the second sticking The combination unit has the same configuration as the corresponding unit of the first manufacturing unit, and thus description thereof is omitted.

  The substrate W1 manufactured in the first manufacturing unit is transferred to the second manufacturing unit. In the transfer process or in the second manufacturing unit, the substrate W1 is turned upside down. The upside down means (not shown) is configured to suck the substrate W1 from the upper surface by the suction means, lift it, turn it upside down, and place it again on the transport mechanism. This control depends on the function of the second control means. As another embodiment, a configuration in which the upside down process is not performed is also possible. In this case, in the second manufacturing section, the second sheet product 2 is processed differently from the normal one in an inverted state (with the release film on the upper surface), and the second optical member is mounted on the substrate W1. It is configured to stick together from the bottom. When the second optical member is bonded to the first optical member in a 90 ° relationship (crossed Nicols relationship), the second optical member is bonded after the substrate W1 is rotated 90 °.

  A 1st control means and a 2nd control means control so that the said means of each process may be interlocked. Each operation timing is calculated by arranging a sensor at a predetermined position or detecting a rotating member of the transport mechanism with a rotary encoder or the like. The first and second control means may be realized by the cooperation of a software program and a hardware resource such as a CPU and a memory. In this case, the program software, processing procedure, various settings, etc. are stored in the memory in advance. ing. Further, it can be configured by a dedicated circuit or firmware.

(Another embodiment)
In the above embodiment, the sheet product including the defective portion is collected by being bonded to the temporary plate unit. However, the sheet product may be bonded to the strip-shaped separator and wound and recovered.

  A known defect inspection method can be applied to the defect inspection. Examples of the defect inspection method include an automatic inspection device and a visual inspection by an inspector. The automatic inspection apparatus is an apparatus that automatically inspects defects (also referred to as defects) of a sheet product. The automatic inspection apparatus emits light, and the reflected light image and the transmitted light image are image sensors such as a line sensor and a two-dimensional TV camera. The defect detection is performed based on the acquired image data. Further, the image data is acquired in a state where the inspection polarizing filter is interposed in the optical path between the light source and the imaging unit. Usually, the polarization axis (for example, the polarization absorption axis) of the polarizing filter for inspection is arranged to be in a state (crossed Nicols) orthogonal to the polarization axis (for example, the polarization absorption axis) of the polarizing plate to be inspected. . By arranging in crossed Nicols, a black image is input from the imaging unit if there is no defect, but if there is a defect, that part will not be black (recognized as a bright spot). Therefore, a defect can be detected by setting an appropriate threshold value. In such bright spot detection, defects such as surface deposits and internal foreign matter are detected as bright spots. In addition to this bright spot detection, there is also a method of detecting a foreign object by CCD imaging a transmitted light image on an object and analyzing the image. There is also a method for detecting a surface-attached foreign substance by subjecting an object to a reflected light image by CCD imaging and analyzing the image.

  The present invention will be described below with reference to examples, but the present invention is not limited to the examples shown below.

[Creating a polarizer]
A polyvinyl alcohol film having an average degree of polymerization of 2700 and a thickness of 75 μm was stretched and conveyed while being dyed between rolls having different peripheral speeds. First, it was immersed in a 30 ° C. water bath for 1 minute to swell the polyvinyl alcohol film and stretched 1.2 times in the conveying direction, and then a 30 ° C. potassium iodide concentration of 0.03% by weight and an iodine concentration of 0.3 By immersing in a weight% aqueous solution for 1 minute, the film was stretched 3 times in the transport direction with reference to a film (original length) that was not stretched at all while dyeing. Next, the film was stretched 6 times based on the original length in the conveying direction while being immersed in an aqueous solution having a boric acid concentration of 4% by weight and a potassium iodide concentration of 5% by weight for 30 seconds. Next, the obtained stretched film was dried at 70 ° C. for 2 minutes to obtain a polarizer. The polarizer had a thickness of 30 μm and a moisture content of 14.3% by weight.

[Adhesive applied to transparent protective film]
Polyvinyl alcohol resin having an acetoacetyl group (average polymerization degree 1200, saponification degree 98.5% mol%, acetoacetyl group modification degree 5 mol%) 100 parts by weight, 50 parts by weight of methylol melamine at 30 ° C. It melt | dissolved in the pure water under temperature conditions, and prepared the aqueous solution with a solid content density | concentration of 3.7 weight%. A metal colloid-containing adhesive aqueous solution was prepared by adding 18 parts by weight of an aqueous solution containing a positively charged alumina colloid (average particle diameter of 15 nm) at a solid concentration of 10% by weight to 100 parts by weight of this aqueous solution. The viscosity of the adhesive solution was 9.6 mPa · s, the pH was in the range of 4 to 4.5, and the compounding amount of the alumina colloid was 74 parts by weight with respect to 100 parts by weight of the polyvinyl alcohol resin. The average particle diameter of the alumina colloid is measured by a dynamic light scattering method (light correlation method) using a particle size distribution meter (manufactured by Nikkiso, product name “Nanotrack UAP150”).

[Formation of adhesive layer]
<Preparation of acrylic polymer>
In a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer, 100 parts of butyl acrylate, 3 parts of acrylic acid, 0.1 part of 2-hydroxyethyl acrylate and 2,2′-azobisisobutyrate A solution was prepared by adding 0.3 parts of ronitrile with ethyl acetate. Next, the solution was stirred while blowing nitrogen gas and reacted at 55 ° C. for 8 hours to obtain a solution containing an acrylic polymer having a weight average molecular weight of 2.2 million. Furthermore, the acrylic polymer solution which added ethyl acetate to the solution containing this acrylic polymer and adjusted solid content concentration to 30% was obtained.

  As a cross-linking agent, 100 parts by weight of the solid content of the acrylic polymer solution is a cross-linking agent mainly composed of a compound having an isocyanate group of 0.5 part (manufactured by Nippon Polyurethane Co., Ltd., trade name “Coronate L”). And 0.075 parts of γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KMB-403”) as a silane coupling agent in this order, Was prepared. The pressure-sensitive adhesive solution was applied to the surface of a release sheet composed of a peeled polyethylene terephthalate film (thickness 38 μm) so that the thickness after drying was 25 μm, and dried to form a pressure-sensitive adhesive layer.

[Transparent protective film]
A 80 μm thick triacetylcellulose film (trade name “TD-TAC” manufactured by Fuji Film Co., Ltd.) was used.

Example 1
[Creation of polarizing plate]
A roll machine is used on one side of the polarizer, with the adhesive applied to one side of the transparent protective film so that the thickness of the adhesive layer after drying is 80 nm. Were bonded together and dried at 70 ° C. for 6 minutes to prepare a polarizing plate having a transparent protective film only on one side.

[Adhesive applied to the adhesive layer]
As an isocyanate-based adhesive, a solution obtained by diluting Aquanate 200 (manufactured by Nippon Polyurethane Industry Co., Ltd.) with water to 10% by weight was used.

[Creation of adhesive-type polarizing plate]
The isocyanate adhesive was applied to the polarizer surface of the polarizing plate (the polarizer surface not provided with a transparent protective film) so that the thickness after drying was 0.8 μm with a gravure coater. Immediately after that, the pressure-sensitive adhesive layer formed on the release-treated surface of the release sheet was bonded, and then dried at 70 ° C. for 5 minutes to solidify the adhesive, thereby preparing a pressure-sensitive adhesive polarizing plate.

Example 2
Example 1 except that the polyvinyl alcohol adhesive solution used as an adhesive applied to the transparent protective film was used instead of the isocyanate adhesive as the adhesive applied to the pressure-sensitive adhesive layer in Example 1. In the same manner, an adhesive polarizing plate was prepared.

Example 3
[Adhesive applied to the adhesive layer]
As a cyanoacrylate adhesive, Aron Alpha (manufactured by Toa Gosei Co., Ltd.) was used.

[Creation of adhesive-type polarizing plate]
The thickness of the polarizer after drying with a slot die is 1 μm on one side of the polarizer of the polarizing plate obtained in Example 1 (polarizer side not provided with a transparent protective film). It was applied as follows. Immediately after that, the pressure-sensitive adhesive layer formed on the release-treated surface of the release sheet was bonded, and then dried at 70 ° C. for 5 minutes to solidify the adhesive, thereby preparing a pressure-sensitive adhesive polarizing plate.

Comparative Example 1
[Creation of adhesive-type polarizing plate]
The pressure-sensitive adhesive layer formed on the release-treated surface of the release sheet was bonded to the polarizer surface (polarizer surface not provided with a transparent protective film) of the polarizing plate obtained in Example 1, and the pressure-sensitive adhesive type. A polarizing plate was created.

Comparative Example 2
[Creation of adhesive-type polarizing plate]
After drying a urethane base coat (manufactured by Toyo Tire & Rubber Co., Ltd., Soflan Primer U-006) on the polarizer surface (polarizer surface not provided with a transparent protective film) of the polarizing plate with a gravure coater. After coating so that the thickness of the film was 0.2 μm, it was dried at 70 ° C. for 5 minutes to form an undercoat layer on the polarizer surface. The pressure-sensitive adhesive layer formed on the release treatment surface of the release sheet was transferred to the undercoat layer to prepare a pressure-sensitive adhesive polarizing plate.

Comparative Example 3
[Creation of adhesive-type polarizing plate]
Polyvinyl alcohol-based primer (Denkapoval B-17, manufactured by Denki Kagaku Kogyo Co., Ltd.) is dried on the polarizer surface of the polarizing plate (polarizer surface not provided with a transparent protective film) with a gravure coater. After coating so that the subsequent thickness was 0.2 μm, it was dried at 70 ° C. for 5 minutes to form an undercoat layer on the polarizer surface. The pressure-sensitive adhesive layer formed on the release treatment surface of the release sheet was transferred to the undercoat layer to prepare a pressure-sensitive adhesive polarizing plate.

  The following evaluation was performed about the adhesive polarizing plate obtained by the said Example and comparative example. The results are shown in Table 1.

(Adhesive residue)
The pressure-sensitive adhesive polarizing plate is cut to a size of 25 mm × 150 mm, and the pressure-sensitive adhesive layer surface thereof is bonded onto a clean glass plate (5 cm × 5 cm), and the environment is 23 ° C./50% RH, 60 ° C. / After being left for 100 hours in an environment of 92% RH and 80 ° C., the adhesive polarizing plate was peeled from the glass plate. The adhesive residue on the glass surface after peeling was observed with the naked eye and an optical microscope (50 times), and evaluated according to the following criteria.
○: No adhesive residue was observed with the naked eye and under a microscope.
Δ: No adhesive residue in visual observation. There is adhesive residue in microscopic observation.
X: Adhesive residue is observed with the naked eye and under a microscope.

P Polarizer E Transparent protective film H Easy adhesion layer G1 Adhesive layer (transparent protective film side)
G2 Adhesive layer (adhesive layer side)
B Adhesive layer W Substrate

Claims (6)

A transparent protective film (E) is provided only on one side of the polarizer (P) via a first adhesive layer (G1), and a second adhesive layer is provided on the other side of the polarizer (P). An adhesive polarizing plate in which the adhesive layer (B) is provided via (G2),
The second adhesive layer (G2) includes the polarizer (P) and the pressure-sensitive adhesive layer (B) in a state where the adhesive (G2 ′) forming the second adhesive layer (G2) is not solidified. A pressure-sensitive adhesive polarizing plate formed by solidifying the adhesive (G2 ′) after bonding together.   The adhesive (G2 ') forming the second adhesive layer (G2) is a polyvinyl alcohol adhesive, an isocyanate adhesive, a cyanoacrylate adhesive, or an aziridine adhesive. 1. The pressure-sensitive adhesive polarizing plate according to 1. A transparent protective film (E) is provided only on one side of the polarizer (P) via a first adhesive layer (G1), and a second adhesive layer is provided on the other side of the polarizer (P). (G2) is a method for producing a pressure-sensitive adhesive polarizing plate in which the pressure-sensitive adhesive layer (B) is provided,
In the lamination of the polarizer (P) and the pressure-sensitive adhesive layer (B), the adhesive (G2 ′) is not solidified by the adhesive (G2 ′) forming the second adhesive layer (G2). A method for producing an adhesive polarizing plate, comprising: bonding a polarizer (P) and an adhesive layer (B) in a state, and then solidifying the adhesive (G2 ′).   The adhesive (G2 ') forming the second adhesive layer (G2) is a polyvinyl alcohol adhesive, an isocyanate adhesive, a cyanoacrylate adhesive, or an aziridine adhesive. 3. A method for producing an adhesive polarizing plate according to 3.   An image display device comprising the pressure-sensitive adhesive polarizing plate according to claim 1. A method for manufacturing an image display device according to claim 5,
A roll original fabric preparation step of preparing the long sheet of the pressure-sensitive adhesive polarizing plate according to claim 1 or 2 as a roll original fabric,
A cutting step of drawing out the sheet product from the raw roll and cutting the adhesive polarizing plate into a predetermined size using a cutting means;
After the cutting step, a bonding step of bonding to the optical display unit via the pressure-sensitive adhesive layer (B) of the pressure-sensitive adhesive polarizing plate;
A method for manufacturing an image display device having

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