TW202118637A - Layered body, layered body manufacturing method, and polarizing plate manufacturing method - Google Patents

Abstract

This layered body includes: a support body; and a light-transmitting resin layer disposed on the surface of the support body so as to be removeable therefrom. The light-transmitting resin layer contains: a (meth) acrylic resin having a weight-average molecular weight of at least 1,000,000; and rubber particles. The layered body has a tensile elastic modulus, at 25 DEG C, of 2.0-6.0GPa.

Description

Laminated body, laminated body manufacturing method, polarizing plate manufacturing method

The present invention relates to a laminated body, a method of manufacturing a laminated body, and a method of manufacturing a polarizing plate.

A polarizing plate used in a display device such as a liquid crystal display device or an organic EL display device includes a polarizer and a protective film for protecting it. In recent years, display devices used for mobile applications such as smartphones and tablet terminals have been required to be thinner, and the polarizing plates and protective films of the components are also required to be thinner.

The protective film system is generally produced by a method (solution casting method) of dissolving resin in a solvent, casting a solution called dope, and then drying it (solution casting method). Then, the obtained protective film is bonded to the polarizer to manufacture a polarizing plate.

On the other hand, as a method of manufacturing a polarizing plate with a thinner protective film, there is a proposal from a peelable laminate film (laminated body) having a base film (support) and a translucent film (translucent resin layer). ), a method of manufacturing a polarizing plate by bonding a light-transmitting resin layer to a polarizer and peeling off the base film (see Patent Documents 1 to 3). [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Publication No. 2018-41028 [Patent Document 2] Japanese Patent Application Publication No. 2018-45220 [Patent Document 3] JP 2013-134336 A

[The problem to be solved by the invention]

However, the laminates shown in Patent Documents 1 to 3 are formed by coating a light-transmitting resin layer paint on a belt-shaped support, or combining the material for the support and the material for the light-transmitting resin layer. The solution is co-cast and manufactured. In addition, the obtained laminated system is transported or stored in a rolled-up state, and is used after being rolled out of the roll body when manufacturing the polarizing plate.

However, during conveyance or storage of the roll body of the laminated body, deformation of the roll body (winding deformation) is likely to occur, and there is a problem that the deformation is easily transferred to the surface of the light-transmitting resin layer. The deformation of such a roll body is that the longer the length and the wider the width of the laminated body, the more likely it is to occur remarkably. The same problem occurs during the transportation or storage of the obtained polarizing plate roll body.

In addition, since the thickness of the light-transmitting resin layer is as thin as 10 μm or less, for example, it is required that the light-transmitting resin layer does not break even when the laminate is conveyed by a roller or the like while applying tension to the laminate.

The present invention was completed in view of the above circumstances, and its object is to provide a place that prevents breakage during transportation of the laminate, and can suppress the winding deformation when the laminate or polarizing plate is wound into a roll and stored for a certain period of time. A laminate with accompanying surface defects and its manufacturing method, and a method for manufacturing a polarizing plate using the laminate. [Means to solve the problem]

The above-mentioned problem can be solved by the following configuration.

The laminate system of the present invention has a laminate of a support and a light-transmitting resin layer releasably disposed on the surface thereof, and the light-transmitting resin layer contains a (meth)acrylic resin having a weight average molecular weight of 1 million or more With rubber particles, the tensile elastic modulus of the aforementioned laminate at 25°C is 2.0 to 6.0 GPa.

The manufacturing method of the laminate of the present invention includes the steps of obtaining a solution for a translucent resin layer containing a (meth)acrylic resin having a weight average molecular weight of 1 million or more, rubber particles, and a solvent; The step of applying a solution to the surface of the support; and, removing the solvent from the solution for the translucent resin layer provided above to form a translucent resin layer, and obtaining a tensile modulus of elasticity at 25° C. Steps for the lamination of 2.0～6.0GPa.

The manufacturing method of the polarizing plate of the present invention includes: laminating the transparent resin layer of the laminate of the present invention on the surface of the polarizing lens; and peeling off the transparent resin layer on the opposite side of the polarizing lens The step of the aforementioned supporting body disposed on the surface. [Effects of the invention]

According to the present invention, it is possible to provide a layer that can suppress surface defects caused by winding deformation when the laminate or polarizing plate is wound into a roll and stored for a certain period of time while suppressing breakage during transportation of the laminate A composite body, a manufacturing method thereof, and a manufacturing method of a polarizing plate using the laminate body.

[The form of implementing the invention]

The inventors of the present inventors intensively studied the results and found that by appropriately increasing the tensile elastic modulus of the entire laminate and containing high-molecular-weight (meth)acrylic resin and rubber particles in the light-transmitting resin layer, it is possible to While suppressing the breakage of the translucent resin layer during transportation, it suppresses the deformation during winding into a roll.

Although the reason for this is not clear, it is estimated as follows. For example, by adjusting the monomer composition of the (meth)acrylic resin contained in the translucent resin layer, etc., the tensile elastic modulus of the laminate is appropriately increased, and the laminate system is moderately hardened, so it is not easy to Deformation of the reel body has occurred.

On the other hand, if the tensile modulus of the laminate is increased excessively, the light-transmitting resin layer is likely to be broken when being conveyed under tension. In contrast, by setting the (meth)acrylic resin contained in the translucent resin layer to a high molecular weight, not only the toughness can be improved, but also by further containing rubber particles in the translucent resin layer, it can be made Follow the tension softly. Therefore, when the laminate is conveyed, the light-transmitting resin layer can be prevented from breaking due to conveying tension, and conveying stability can be improved. In addition, since the light-transmitting resin layer contains rubber particles, even when the roll body of the laminate is deformed, the restoring force of the rubber particles can easily return the light-transmitting resin layer to its original shape. Not easy to remain. In the roll body of the polarizing plate, the roll body is not easily deformed, and the light-transmitting resin layer can be easily returned to its original shape.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1. Laminated body Fig. 1 is a cross-sectional view of a laminate showing an embodiment of the present invention. As shown in FIG. 1, the laminated body 100 of this embodiment has the support body 110 and the translucent resin layer 120 arrange|positioned peelably on the surface.

Furthermore, the tensile elastic modulus G of the laminate is preferably 2.0 to 6.0 GPa. If the tensile elastic modulus G of the laminate is 2.0 GPa or more, during storage of the roll body of the laminate or the roll body of the polarizing plate obtained therefrom, the winding deformation is unlikely to occur. If the tensile elastic modulus G of the laminate is 6.0 GPa or less, when conveying the laminate while applying conveying tension to the laminate, the translucent resin layer is less likely to be broken, and conveying stability can be improved. From the same viewpoint, the tensile elastic modulus G of the laminate is more preferably 3.5 to 5.5 GPa.

The tensile elastic modulus G of the laminate can be measured by the following procedure. (1) Cut out 1 cm×10 cm from the laminate and use it as a sample. The sample was humidity-conditioned for 24 hours under an environment of 25°C and 60%RH. (2) Next, the tensile modulus of the obtained sample is measured by the tensile test method described in JIS K7127:1999 (ISO 527-3:1995). Specifically, the sample is set in a tensile testing device (for example, a universal testing machine manufactured by ORIENTEC), a tensile test is performed under the conditions of a distance between chucks of 50.0 mm and a tensile speed of 50 mm/min, and the tensile modulus of elasticity is measured . The measurement is performed at 25°C and 60%RH.

The tensile elastic modulus G of the laminate can be adjusted by the tensile elastic modulus G1 of the support and the tensile elastic modulus G2 of the translucent resin layer. The tensile elastic modulus G1 of the support can be adjusted by the material of the support, heat treatment, and extension treatment. The tensile modulus G2 of the translucent resin layer can be adjusted by the composition of the translucent resin layer (especially the monomer composition or weight average molecular weight of the (meth)acrylic resin).

1-1. Support The support is not particularly limited as long as it can support the light-transmitting resin layer, but it can usually contain a resin film.

Examples of resin films include polyester resin films (such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), Polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), etc.), cycloolefin resin film (COP), acrylic film, cellulose resin film (e.g. triacetyl cellulose Film (TAC) etc.). Among them, from the viewpoint of versatility and high tensile elastic modulus, PET film, triacetyl cellulose film (TAC), and cycloolefin resin film are preferred.

The resin film can be thermally relaxed or stretched.

Thermal relaxation can reduce the degree of crystallinity and orientation by heat-treating the support. Therefore, the tensile elastic modulus G1 of the resin film and the support can be reduced. The thermal relaxation temperature is not particularly limited, but when the glass transition temperature of the resin constituting the resin film is regarded as Tg, it can be performed at (Tg+60) to (Tg+180)°C. Thermal relaxation may be performed before forming the release layer, or may be performed after forming the release layer.

The stretching treatment improves the orientation of the resin molecules by stretching the resin film, thereby increasing the tensile elastic modulus G1 of the resin film and the support. The stretching treatment may be performed in the uniaxial direction of the support, or may be performed in the biaxial direction, for example. The stretching treatment can be performed under arbitrary conditions, for example, the stretching ratio can be about 120 to 900%. The stretch magnification is the value obtained by multiplying the stretch magnification in each direction. Whether or not the resin film is stretched (whether it is a stretched film) can be confirmed by, for example, whether there is an in-plane slow axis (the axis that stretches in the direction where the refractive index becomes the largest).

The support body preferably further has a release layer provided on the surface of the resin film. The release layer can easily peel the light-transmitting resin layer from the support when producing the polarizing plate.

The release layer may contain a well-known release agent, and is not particularly limited. Examples of the release agent contained in the release layer include a silicone release agent and a non-silicone release agent.

Examples of silicone-based release agents include well-known silicone-based resins. Examples of non-silicone-based release agents include long-chain alkyl pendant polymers formed by reacting long-chain alkyl isocyanates with polyvinyl alcohol or ethylene-vinyl alcohol copolymers, and olefin-based resins (e.g., copolymers). Polyethylene, cyclic polyolefin, polymethylpentene), polyarylate resin (e.g. polycondensate of aromatic dicarboxylic acid component and dihydric phenol component), fluororesin (e.g. polytetrafluoroethylene (PTFE)) , Polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), PFA (copolymer of tetrafluoroethylene and perfluoroalkoxyethylene), FEP (copolymer of tetrafluoroethylene and hexafluoropropylene), ETFE ( Copolymer of tetrafluoroethylene and ethylene)) etc.

The release layer may further contain additives as necessary. Examples of additives include fillers, lubricants (wax, fatty acid esters, fatty acid amides, etc.), stabilizers (antioxidants, heat stabilizers, light stabilizers, etc.), flame retardants, viscosity regulators, and Adhesive, defoamer, UV absorber.

The thickness of the release layer is not particularly limited as long as it can exhibit the desired releasability, but for example, it is preferably 0.1 to 1.0 μm.

(Tensile elastic modulus G1) The tensile elastic modulus G1 of the support body may be set so that the tensile elastic modulus G of the laminate satisfies the above-mentioned range, and is not particularly limited, but may be 2.0 to 6.0 GPa, for example. If the tensile elastic modulus G1 of the support is 2.0 GPa or more, the winding deformation can be less likely to occur during the storage of the roll body of the laminate or the roll body of the polarizing plate. If the tensile elastic modulus G1 of the support is 6.0 GPa or less, when the laminate is conveyed while applying tension to the laminate, it is difficult to break the support or the laminate, and the conveyance stability can be improved. The tensile elastic modulus G1 of the support is the same as the above, which can be carried out by Measured by the tensile test described in JIS K7127:1999 (ISO 527-3:1995). When the support has anisotropy, prepare two types of samples in the alignment direction (in-plane slow axis direction, such as the TD direction) and the orthogonal direction (such as the MD direction), and measure each to obtain their average value. .

(thickness) The thickness of the support is not particularly limited, but for example, it is preferably 10-100 μm, more preferably 25-50 μm.

1-2. Translucent resin layer The translucent resin layer is arranged on the support. The light-transmitting resin layer is peeled from the support and bonded with a polarizer to form a polarizing plate, and may have a function of an optical film such as a protective film (including a retardation film).

The light-transmitting resin layer contains high-molecular-weight (meth)acrylic resin and rubber particles.

1-2-1. (Meth) acrylic resin The weight average molecular weight (Mw) of the (meth)acrylic resin is preferably 1 million or more. If the weight average molecular weight of the (meth)acrylic resin is 1 million or more, the toughness of the obtained translucent resin layer can be improved. Therefore, even if the tensile elastic modulus of the laminate is increased, the light-transmitting resin layer is less likely to be broken due to the conveying tension. In addition, since the tensile modulus of elasticity of the light-transmitting resin layer can also be increased, the winding deformation may not easily occur. From the same viewpoint, the weight average molecular weight of the (meth)acrylic resin is more preferably 1.5 million to 3 million.

The weight average molecular weight (Mw) of the (meth)acrylic resin can be measured in terms of polystyrene by gel permeation chromatography (GPC). Specifically, HLC8220GPC manufactured by Tosoh Corporation, pipe string (TSK-GEL G6000HXL-G5000HXL-G5000HXL- manufactured by Tosoh Corporation in series) can be used. G4000HXL-G3000HXL) for measurement. The measurement conditions can be the same as in the examples described later.

The (meth)acrylic resin whose weight average molecular weight satisfies the above-mentioned range contains at least a structural unit (U1) derived from methyl methacrylate. Among them, from the viewpoint of increasing the tensile elastic modulus G2 of the light-transmitting resin layer and preventing the winding deformation of the roll body during storage in the roll body, the (meth)acrylic resin is more preferable to contain the source The structural unit (U2) derived from the phenylmaleimide, from the viewpoint of improving the brittleness caused by the inclusion of the structural unit (U2), etc., it is more preferable to further include the structural unit derived from the alkyl acrylate (U3 ).

That is, the (meth)acrylic resin preferably contains a structural unit (U1) derived from methyl methacrylate, a structural unit (U2) derived from phenylmaleimide, and a structural unit derived from alkyl acrylate. Structural unit (U3).

The content of the structural unit (U1) derived from methyl methacrylate relative to all the structural units constituting the (meth)acrylic resin is preferably 50 to 95% by mass, more preferably 70 to 90% by mass.

Since the structural unit (U2) derived from phenylmaleimide has a relatively rigid structure, the tensile modulus G2 of the translucent resin layer can be increased. In addition, the structural unit (U2) derived from phenylmaleimide has a relatively bulky structure and has microvoids that enable the rubber particles to move in the resin matrix. Therefore, the rubber particles can be easily biased to exist in the light-transmitting matrix. The surface part of the resin layer.

The content of the structural unit (U2) derived from phenylmaleimide relative to all structural units constituting the (meth)acrylic resin is preferably 1 to 25% by mass. If the content of the structural unit (U2) derived from phenylmaleimide is 1% by mass or more, it is easy to increase the tensile modulus G2 of the translucent resin layer, and if it is 25% by mass or less, it is not easy to be excessive The brittleness of the translucent resin layer is impaired. Based on the above viewpoint, the content of the structural unit (U2) derived from phenylmaleimide is more preferably 7 to 15% by mass.

Since the structural unit (U3) derived from alkyl acrylate can impart moderate flexibility to the resin, for example, the brittleness caused by containing the structural unit (U2) derived from phenylmaleimide can be improved.

The number of carbon atoms in the alkyl portion of the alkyl acrylate is preferably from 1 to 7, more preferably from 1 to 5 alkyl acrylate. Examples of alkyl acrylate include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-hydroxyethyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, and the like.

The content of the structural unit (U3) derived from alkyl acrylate is preferably 1 to 25% by mass relative to all the structural units constituting the (meth)acrylic resin. If the content of the structural unit (U3) derived from alkyl acrylate is 1% by mass or more, moderate flexibility can be imparted to the (meth)acrylic resin, so the translucent resin layer does not become excessively brittle and is not easily broken . If the content of the structural unit (U3) derived from alkyl acrylate is 25% by mass or less, the Tg of the translucent resin layer does not become too low, so the heat resistance or tensile elastic modulus G2 of the translucent resin layer is not easy Excessive reduction. Based on the above viewpoint, the content of the structural unit derived from alkyl acrylate is more preferably 5 to 15% by mass.

The ratio of the structural unit (U2) derived from phenylmaleimid to the total amount of the structural unit derived from phenylmaleimid (U2) and the structural unit derived from alkyl acrylate (U3) Preferably it is 20-70 mass %. If the ratio is 20% by mass or more, it is easy to increase the tensile modulus G2 of the translucent resin layer, and if it is 70% by mass or less, the translucent resin layer is not excessively brittle.

The glass transition temperature (Tg) of the (meth)acrylic resin is preferably 100°C or higher, more preferably 120 to 150°C. If the Tg of the (meth)acrylic resin is within the above range, the heat resistance of the light-transmitting resin layer can be easily improved. In order to adjust the Tg of the (meth)acrylic resin, for example, it is preferable to adjust the content of the structural unit (U2) derived from phenylmaleimide or the structural unit (U3) derived from alkyl acrylate.

With respect to the translucent resin layer, the content of the (meth)acrylic resin is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more.

1-2-2. Rubber particles The rubber particles may have a function of imparting toughness (flexibility) to the translucent resin layer.

The rubber particles are particles containing rubber-like polymers. The rubbery polymer is a soft crosslinked polymer with a glass transition temperature of 20°C or less. Examples of such cross-linked polymers include butadiene-based cross-linked polymers, (meth)acrylic-based cross-linked polymers, and organosiloxane-based cross-linked polymers. Among them, from the viewpoint that the refractive index difference with the (meth)acrylic resin is small and the transparency of the translucent resin layer is not easily impaired, the (meth)acrylic crosslinked polymer is preferred, and the acrylic is more preferred. Cross-linked polymer (acrylic rubber-like polymer).

That is, the rubber particles are preferably particles containing the acrylic rubber-like polymer (a).

Regarding acrylic rubber-like polymer (a): The acrylic rubber-like polymer (a) is a crosslinked polymer containing a structural unit derived from acrylate as a main component. Included as a main component means that the content of the structural unit derived from acrylate is in the range described later. The acrylic rubber-like polymer (a) preferably contains a structural unit derived from an acrylate, a structural unit derived from another monomer copolymerizable therewith, and a structural unit derived from having two or more radically polymerizable groups in one molecule. (Non-conjugated reactive double bond) is a cross-linked polymer of the structural unit of a multifunctional monomer.

The acrylate is preferably methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, second butyl acrylate, isobutyl acrylate, benzyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate , N-octyl acrylate and other alkyl acrylates with 1-12 carbon atoms. There may be one type of acrylate, or two or more types.

The content of the acrylate-derived structural unit relative to all the structural units constituting the acrylic rubber-like polymer (a1) is preferably 40 to 90% by mass, more preferably 50 to 80% by mass. If the content of the acrylate is within the above range, it is easy to impart sufficient toughness to the protective film.

Other monomers that can be copolymerized are those other than polyfunctional monomers among the monomers that can be copolymerized with acrylate. That is, the copolymerizable monomer does not have two or more radical polymerizable groups. Examples of copolymerizable monomers include methacrylates such as methyl methacrylate; styrenes such as styrene and methyl styrene; (meth)acrylonitrile; (meth)acrylic acid Amides; (meth)acrylic acid. Among them, other copolymerizable monomers preferably include styrenes. The other monomers that can be copolymerized may be one type or two or more types.

The content of the structural unit derived from other copolymerizable monomers is preferably 5 to 55% by mass, more preferably 10 to 45% by mass relative to all the structural units constituting the acrylic rubber-like polymer (a).

Examples of multifunctional monomers include allyl (meth)acrylate, triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, and malic acid Diallyl ester, divinyl adipate, divinylbenzene, ethylene glycol di(meth)acrylate, diethylene glycol (meth)acrylate, triethylene glycol di(meth)acrylate , Trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, dipropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate.

The content of the structural unit derived from the polyfunctional monomer is preferably from 0.05 to 10% by mass, and more preferably from 0.1 to 5% by mass, relative to all the structural units constituting the acrylic rubber-like polymer (a). If the content of the polyfunctional monomer is 0.05% by mass or more, it is easy to increase the degree of crosslinking of the acrylic rubber-like polymer (a) obtained, so the hardness and rigidity of the obtained translucent resin layer are not excessively impaired. When the content is 10% by mass or less, the toughness of the translucent resin layer is less likely to be impaired.

The composition of the monomers constituting the acrylic rubber-like polymer (a) can be measured by, for example, the peak area ratio detected by thermal decomposition GC-MS.

The glass transition temperature (Tg) of the rubber-like polymer is preferably 0°C or lower, more preferably -10°C or lower. If the glass transition temperature (Tg) of the rubbery polymer is 0°C or less, appropriate toughness can be imparted to the film. The glass transition temperature (Tg) of the rubber-like polymer is measured by the same method as described above.

The glass transition temperature (Tg) of the rubber-like polymer can be adjusted by the composition of the rubber-like polymer. For example, in order to lower the glass transition temperature (Tg) of the acrylic rubber-like polymer (a), it is preferable to increase the acrylic rubber-like polymer (a) whose alkyl group has 4 or more carbon atoms. The mass ratio of other monomers to be polymerized (for example, 3 or more, preferably 4-10).

The particles containing the acrylic rubber-like polymer (a) may be particles composed of the acrylic rubber-like polymer (a), or may be a hard crosslinked polymer having a glass transition temperature of 20°C or higher (c ) Formed by the hard layer and the particles of the soft layer formed by the acrylic rubber-like polymer (a) arranged around it (also referred to as "elastomers"); it can also be made of acrylic rubber In the presence of the polymer (a), the acrylic graft copolymer obtained by polymerizing a mixture of monomers such as methacrylate in at least one stage. The particles formed from the acrylic graft copolymer may be core-shell particles having a core containing the acrylic rubber-like polymer (a) and a shell covering it.

Regarding core-shell rubber particles containing acrylic rubber-like polymers: (Core) The core part contains an acrylic rubber-like polymer (a), and may further contain a hard crosslinked polymer (c) if necessary. That is, the core may have a soft layer made of an acrylic rubber-like polymer and a hard layer made of a hard cross-linked polymer (c) arranged inside the soft layer.

The crosslinked polymer (c) may be a crosslinked polymer mainly composed of methacrylate. That is, the crosslinked polymer (c) preferably contains a structural unit derived from alkyl methacrylate, a structural unit derived from another monomer copolymerizable therewith, and a structural unit derived from a polyfunctional monomer. Cross-linked polymer.

The alkyl methacrylate may be the aforementioned alkyl methacrylate; the other monomers that can be copolymerized may be the aforementioned styrenes or acrylic esters, etc.; the polyfunctional monomers may be those exemplified as the aforementioned polyfunctional monomers same.

The content of the structural unit derived from alkyl methacrylate may be 40 to 100% by mass relative to all the structural units constituting the crosslinked polymer (c). The content of the structural units derived from other monomers that can be copolymerized may be 60 to 0% by mass relative to all the structural units constituting the other crosslinked polymer (c). The content of the structural unit derived from the polyfunctional monomer may be 0.01-10% by mass relative to all the structural units constituting the other crosslinked polymer.

(Shell) The shell part contains a methacrylic polymer (b) (other polymer) graft-bonded to the acrylic rubber-like polymer (a) and containing a methacrylate-derived structural unit as a main component. What is contained as a main component means that the content of the structural unit derived from methacrylate is in the range mentioned later.

The methacrylate constituting the methacrylic polymer (b) is preferably an alkyl methacrylate having 1 to 12 carbon atoms in an alkyl group such as methyl methacrylate. There may be one type of methacrylate, or two or more types.

The content of methacrylate is preferably 50% by mass or more with respect to all the structural units constituting the methacrylic polymer (b). If the content of the methacrylate is 50% by mass or more, it is easy to obtain compatibility with a methacrylic resin containing a structural unit derived from methyl methacrylate as a main component. Based on the above viewpoint, the content of methacrylate is more preferably 70% by mass or more with respect to all the structural units constituting the methacrylic polymer (b).

The methacrylic polymer (b) may further include structural units derived from other monomers copolymerizable with methacrylate. Examples of other monomers that can be copolymerized include acrylates such as methyl acrylate, ethyl acrylate, n-butyl acrylate, etc.; benzyl (meth)acrylate, dicyclopentyl (meth)acrylate, (meth) (Meth)acrylic monomers (cyclic (meth)acrylic monomers) having an alicyclic, heterocyclic, or aromatic ring such as phenoxyethyl acrylate and the like.

The content of the structural unit derived from the copolymerizable monomer is preferably 50% by mass or less, and more preferably 30% by mass or less with respect to all the structural units constituting the methacrylic polymer (b).

The ratio (grafting ratio) of the graft component in the rubber particles is preferably from 10 to 250% by mass, more preferably from 15 to 150% by mass. If the grafting rate is constant or higher, the grafting component, that is, the ratio of the methacrylic polymer (b) mainly composed of methacrylate-derived structural units, is moderately large, and therefore it is easy to increase the rubber particles and The compatibility of methacrylic resin makes rubber particles less likely to agglomerate. In addition, it is unlikely to impair the rigidity of the film. If the graft ratio is constant or less, the ratio of the acrylic rubber-like polymer (a) does not decrease excessively, and therefore it is difficult to impair the toughness or brittleness improvement effect of the film.

The grafting rate is measured by the following method. (1) Dissolve 2 g of core-shell particles in 50 ml of methyl ethyl ketone, and use a centrifugal separator (CP60E manufactured by Hitachi Koki Co., Ltd.) to centrifuge at 30,000 rpm and a temperature of 12°C for 1 hour to separate Insoluble and soluble components (a total of 3 sets of centrifugal separation operations). (2) Apply the following formula to the weight of the obtained insolubles to calculate the grafting rate. Grafting rate (mass%)=[{(mass of methyl ethyl ketone insoluble content)-(mass of acrylic rubber-like polymer (a)))/(mass of acrylic rubber-like polymer (a)) ]×100

The shape of the rubber particles is not particularly limited, but it is preferably a shape close to a true spherical shape. The shape close to a true spherical shape refers to a shape in which the aspect ratio of the rubber particles is in the range of about 1 to 2 when the cross section or surface of the translucent resin layer is observed. In this way, the rubber particles having a spherical shape are strong against deformation of the laminate due to contact with the roller during transportation or against internal stress during winding, and are easily resistant to deformation.

The average particle diameter of the rubber particles is preferably 100 to 400 nm. If the average particle diameter of the rubber particles is 100 nm or more, it is easy to impart sufficient toughness or stress relaxation to the light-transmitting resin layer, and if it is 400 nm or less, the transparency of the light-transmitting resin layer is less likely to be impaired. From the same viewpoint, the average particle diameter of the rubber particles is more preferably 150 to 300 nm.

The average particle size of rubber particles can be calculated by the following method. The average particle size of the rubber particles can be measured as the average value of the circle-equivalent diameter of 100 particles obtained by SEM photography or TEM photography on the surface or slice of the laminate. The circle equivalent diameter can be obtained by converting the projected area of the particles obtained by photography into the diameter of a circle having the same area. At this time, the rubber particles observed by SEM observation and/or TEM observation at a magnification of 5000 times are used for the calculation of the average particle diameter.

The content of the rubber particles is not particularly limited, but it is preferably 5-50% by mass, more preferably 5-40% by mass, and particularly preferably 5-50% by mass relative to the (meth)acrylic resin contained in the translucent resin layer 7-30% by mass.

(Distribution of rubber particles) The rubber particles may be uniformly dispersed in the thickness direction of the light-transmitting resin layer, or they may be present in a biased manner. Specifically, in the cross section along the thickness direction of the light-transmitting resin layer, the area of the light-transmitting resin layer opposite to the support from the surface of the light-transmitting resin layer that is 20% or less of the thickness of the light-transmitting resin layer is regarded as the area A, the area where the thickness of the transparent resin layer from the support side of the transparent resin layer is less than 20% of the thickness of the transparent resin layer is taken as area B, and the area ratio per unit area of the rubber particles in area A is taken as R _A , when the area ratio per unit area of the rubber particles in the region B is regarded as R _B , R _A /R _B can be 1.0 to 1.1.

Among them, from the viewpoint that stress is less likely to occur when the laminate is curled, or from the viewpoint of improving the adhesion to the polarizer, the rubber particles are preferably present in the surface layer portion of the translucent resin layer (the surface layer portion on the side opposite to the support) ). _{Specifically, the R A} /R _{B of the} translucent resin layer is more preferably 1.05 to 1.1. If R _A /R _B is 1.05 or more, the rubber particles are eccentrically present in the surface layer part of the light-transmitting resin layer. Therefore, since the flexibility or toughness of the surface layer of the light-transmitting resin layer can be improved, not only is it easy to highly suppress breakage during transportation, but also during storage of the roll body of the laminate, no winding deformation occurs. Deformation is transferred to the translucent resin layer, and it can easily return to its original shape. In addition, if R _A /R _B is 1.1 or less, since the difference in toughness between the surface portion and the inside of the translucent resin layer is not excessively large, it is less likely to cause cracks during transportation due to the difference in stress.

Area per unit area of the rubber particles in region A R _A system rate represented by the following formula (1). Formula (1): area ratio per unit area of the area of the rubber particles B × 100 region area ratio R _A (%) = the total area of the rubber particles in the area A / area A in R _B are also defined in the same manner.

R _A light-transmissive resin layer / R _B lines can be measured by the following method of. (1) Cut the translucent resin layer with a microtome, and observe the cut surface perpendicular to the surface of the translucent resin layer by TEM. Observation conditions can be set as acceleration voltage (electron energy irradiated to the sample): 30kV, working distance (distance between the lens and the sample): 8.6mm×magnification: 3.00k. The observation area is an area including the entire thickness direction of the translucent resin layer. (2) After removing the brightness gradient of the obtained TEM image using image processing software of NiVision (manufactured by National Instruments), the cut-off process is performed to detect the contrast difference between the bulk and the rubber particles. Thus, the distribution state of rubber particles is defined. (3) In the image after the image processing obtained in (2) above, in the thickness direction of the translucent resin layer, calculate the area ratio R _A per unit area of the rubber particles in the area A and the area ratio of the rubber particles in the area B. _{The area ratio R B} per unit area of rubber particles. _{(4) Calculate R A} /R _{B from} the results obtained in (3) above.

There are no particular restrictions on the method of biasing the presence of rubber particles, but it can be based on the type of solvent of the transparent resin layer solution or the drying conditions of the coating film (drying temperature or environmental solvent concentration), and the (meth)acrylic resin Composition and so on. In order to facilitate the presence of rubber particles on the surface portion (region A) of the translucent resin layer, as described later, it is preferable to use a solvent with high affinity for rubber particles (for example, ketones such as acetone) as the solvent. It is preferable to increase the drying temperature, and it is preferable to reduce the solvent concentration in the environment. In addition, the (meth)acrylic resin containing a moderately large amount of the structural unit (U2) derived from phenylmaleimide has many microvoids and is likely to cause the rubber particles to diffuse and move. The content of the structural unit (U2) from the phenylmaleimide can also easily bias the presence of rubber particles.

1-2-3. Other ingredients The light-transmitting resin layer may further contain other components than the above as necessary. Examples of other components include matting agents (fine particles), ultraviolet absorbers, and the like.

From the viewpoint of imparting sliding properties to the film, a matting agent may be added. In the case of the matting agent, inorganic fine particles such as silica particles, and organic fine particles having a glass transition temperature of 80°C or higher are included.

Examples of ultraviolet absorbers include benzotriazole-based ultraviolet absorbers, diphenylketone-based ultraviolet absorbers, and triphenyl ketone-based ultraviolet absorbers.

1-2-4. Physical properties (Tensile elastic modulus G2) The tensile elastic modulus G2 of the light-transmitting resin layer may be set so that the tensile elastic modulus G of the laminate satisfies the above-mentioned range, and is not particularly limited, but may be 2.0 to 3.0 GPa, for example. If the tensile elastic modulus G2 of the light-transmitting resin layer is 2.0 GPa or more, the winding deformation can be less likely to occur during the storage of the laminate or the roll body of the polarizing plate. If the tensile modulus G2 of the light-transmitting resin layer is 3.0 GPa or less, it is difficult to break the light-transmitting resin layer when conveying the laminate while applying conveying tension to the laminate, and the conveying stability can be improved.

The tensile modulus G2 of the translucent resin layer can be adjusted mainly by the composition or weight average molecular weight of the (meth)acrylic resin. When increasing the tensile modulus G2 of the translucent resin layer, for example, it is preferable to increase the structural unit (U2) derived from phenylmaleimide in the (meth)acrylic resin, and it is preferable to increase Weight average molecular weight.

The tensile modulus G2 of the translucent resin layer can be measured in the same manner as described above. That is, after peeling the light-transmitting resin layer from the support, the tensile elastic modulus G2 of the light-transmitting resin layer is measured by the same method as described above. Furthermore, when the light-transmitting resin layer has anisotropy, prepare two types of samples in the alignment direction (in-plane slow axis direction) and the direction orthogonal to the two types of samples, measure each of them, and obtain their average value.

The difference ΔG (G1-G2) between the tensile elastic modulus G1 of the support and the tensile elastic modulus G2 of the translucent resin layer is preferably 3.5 GPa or less, more preferably 2.5 GPa or less. If ∆G is 3.5 GPa or less, for example, when coiling tension is applied, the difference in the amount of deformation due to tension due to wrinkles is small, so peeling and breakage due to peeling are less likely to occur.

(Internal Haze) The internal haze of the translucent resin layer is preferably 1.0% or less, more preferably 0.1% or less, and particularly preferably 0.05% or less. The internal haze of the translucent resin layer can be measured by the same method as described above. The internal haze of the translucent resin layer can be adjusted by the content of rubber particles.

(Phase difference Ro and Rt) For the light-transmitting resin layer, for example, from the viewpoint of being used as a retardation film for IPS mode, the phase difference Ro in the in-plane direction measured in an environment with a measurement wavelength of 550nm and 23°C 55%RH is preferably 0-10nm , More preferably 0-5nm. The retardation Rt in the thickness direction of the translucent resin layer is preferably -20 to 20 nm, more preferably -10 to 10 nm.

(式中， nx表示透光性樹脂層之面內慢軸方向(折射率成為最大的方向)的折射率， ny表示與透光性樹脂層之面內慢軸正交的方向之折射率， nz表示透光性樹脂層之厚度方向的折射率， d表示透光性樹脂層之厚度(nm))。Ro and Rt are each defined by the following formula.

(In the formula, nx represents the refractive index in the in-plane slow axis direction (the direction in which the refractive index becomes the maximum) of the translucent resin layer, and ny represents the refractive index in the direction orthogonal to the in-plane slow axis of the translucent resin layer, nz represents the refractive index in the thickness direction of the translucent resin layer, and d represents the thickness (nm) of the translucent resin layer).

The in-plane slow axis system of the translucent resin layer can be confirmed with an automatic birefringence meter Axo Scan (Axo Scan Mueller Matrix Polarimeter: manufactured by AXOMETRICS).

Ro and Rt can be measured by the following method. (1) The light-transmitting resin layer is humidified for 24 hours in an environment of 23°C and 55% RH. The average refractive index of this film was measured with an Abbe refractometer, and the thickness d was measured with a commercially available micrometer. (2) Use automatic birefringence meter Axo Scan (Axo Scan Mueller Matrix Polarimeter: manufactured by AXOMETRICS), measured the hysteresis Ro and Rt of the film after humidity control at a measurement wavelength of 550 nm under an environment of 23° C. and 55% RH.

The phase difference Ro and Rt of the light-transmitting resin layer can be adjusted by, for example, the type of resin, stretching conditions, and drying conditions.

(Amount of residual solvent) The light-transmitting resin layer is obtained by applying a solution for the light-transmitting resin layer, and the solvent (for example, ketones or alcohols) derived from the solution may remain. The amount of residual solvent with respect to the translucent resin layer is preferably 700 ppm or less, more preferably 30 to 700 ppm. The content of the residual solvent can be adjusted by the drying conditions of the solution for the translucent resin layer applied to the support in the manufacturing step of the translucent resin layer.

The amount of residual solvent in the translucent resin layer can be measured by headspace phase chromatography. In the headspace phase chromatography method, the sample is enclosed in a container, heated, and the container is filled with volatile components. The gas in the container is quickly injected into the gas chromatograph for mass analysis to identify the compound. The volatile components are quantified. In the headspace method, the full peaks of volatile components can be observed by gas chromatograph. At the same time, by using the analysis method using electromagnetic interaction, it is also possible to quantify volatile substances or monomers together with high precision. .

(thickness) The thickness of the translucent resin layer is not particularly limited, but from the viewpoint of achieving thinning of the polarizing plate, it is usually thinner than the thickness of the support, specifically, for example, preferably 0.1 to 35 μm, more preferably 1 ~15μm.

The ratio T2/T1 of the thickness T1 of the support to the thickness T2 of the translucent resin layer is preferably 0.01 to 1, more preferably 0.1 to 0.7.

1-3. Other layers The laminated system of this embodiment may further have another layer arranged between the support and the light-transmitting resin layer as necessary.

1-4. The shape of the laminated body Moreover, the form of the laminated body of this embodiment may be a belt shape. That is, the laminated system of this embodiment can be wound into a roll shape in the direction orthogonal to the width direction, and can become a roll body.

2. Manufacturing method of laminated body [Production method] The manufacturing method of the laminated body of this embodiment has: (1) the step of obtaining a solution for the translucent resin layer, (2) the step of applying the obtained translucent resin layer solution to the surface of the support, and (3) The step of removing the solvent from the provided solution for the translucent resin layer to form the translucent resin layer.

Regarding the step of (1) (the step of obtaining a solution for the translucent resin layer) A solution for a translucent resin layer containing the (meth)acrylic resin, the rubber particles, and a solvent is prepared.

The solvent used in the solution for the translucent resin layer is not particularly limited as long as it can disperse the (meth)acrylic resin or rubber particles well. In the example of solvents, alcohols such as methanol, ethanol, propanol, n-butanol, 2-butanol, tert-butanol, cyclohexanol, methyl ethyl ketone, methyl isobutyl ketone, and acetone are included. Ketones, ethyl acetate, methyl acetate, ethyl lactate, isopropyl acetate, amyl acetate, ethyl butyrate and other esters, glycol ethers (propylene glycol mono(C1～C4) alkyl ether (Specifically, propylene glycol monomethyl ether (PGME), propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol monoisopropyl ether, propylene glycol monobutyl ether, etc.), propylene glycol mono(C1～C4) alkane Base ether ester (propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate), toluene, benzene, cyclohexane, n-hexane and other hydrocarbons. Among them, from the viewpoints that the (meth)acrylic resin is easy to dissolve, has a relatively high affinity with rubber particles, has a low boiling point, and is easy to improve the drying speed and productivity, the solvent preferably contains ketones, since it is easy to form a flat surface. From the viewpoint of a high-performance translucent resin layer, it is preferable to further contain alcohols.

That is, the solvent preferably contains ketones and alcohols. The content ratio of ketones and alcohols is not particularly limited, but from the viewpoint of the compatibility of drying speed and flatness, ketones/alcohols=95/5 to 10/90 (mass ratio) are more preferable. Preferably it is 95/5～60/40 (mass ratio), more preferably 95/5～80/20 (mass ratio). If the ratio of ketones is moderately high, it is easy to improve dryness and productivity is also likely to increase. If the ratio of alcohols is moderately high, it is easy to improve the flatness of the coating film.

From the viewpoint of easy adjustment of the viscosity to the range described later, the resin concentration of the solution for the translucent resin layer is preferably 1.0 to 20% by mass, for example.

The viscosity of the solution for the light-transmitting resin layer is not particularly limited as long as it can form a desired thickness of the light-transmitting resin layer. For example, it is preferably 5 to 5000 cP. If the viscosity of the translucent resin layer solution is 5 cP or more, it is easy to form a light translucent resin layer with an appropriate thickness, and if it is 5000 cP or less, it is possible to suppress the occurrence of uneven thickness due to the increase in the viscosity of the solution. From the same viewpoint, the viscosity of the solution for the translucent resin layer is more preferably 100 to 1000 cP. The viscosity of the transparent resin layer solution can be measured with an E-type viscometer at 25°C.

Regarding the step (2) (the step of imparting a solution for the translucent resin layer) Next, the obtained solution for a translucent resin layer is applied to the surface of the support. Specifically, the obtained solution for a translucent resin layer is applied to the surface of the support.

The coating method of the solution for the translucent resin layer is not particularly limited. For example, well-known methods such as back roll coating method, gravure coating method, spin coating method, wire bar coating method, and roll coating method can be used. . Among them, the back coating method is preferred from the viewpoint of forming a thin and uniform thickness of the coating film.

Regarding the step (3) (the step of forming a translucent resin layer) Next, the solvent is removed from the solution for the translucent resin layer applied to the support to form the translucent resin layer.

Specifically, the solution for the translucent resin layer provided to the support is dried. Drying can be performed by blowing or heating, for example. Among them, from the viewpoint of easily suppressing curling of the laminate, etc., drying by blowing air is preferred.

By adjusting the drying conditions (for example, drying temperature, solvent concentration in the environment, drying time, etc.), the amount of residual solvent in the translucent resin layer after drying can be made constant or less. In addition, the distribution state of the rubber particles in the translucent resin layer can be adjusted by drying conditions. Specifically, from the viewpoint that it is easy to bias the presence of rubber particles, it is preferable to use a solvent with good affinity for rubber particles, and to increase the drying temperature, and the solvent concentration in the environment is preferably low.

When the drying temperature takes the boiling point of the solvent as Tb(°C), it is preferably (Tb-50)～(Tb+50)℃, more preferably (Tb-40)～(Tb+40)℃. If the drying temperature is higher than the lower limit value, the evaporation rate of the solvent can be increased, and therefore rubber particles are likely to be unevenly present. If the drying temperature is lower than the upper limit value, the solvent concentration in the environment may not become excessively high. For example, when a mixed solvent of acetone/methanol is used, the drying temperature can be set to 40°C or higher.

The solvent concentration in the environment during drying is preferably 0.10 to 0.30% by mass, more preferably 0.10 to 0.20% by mass. If the solvent concentration in the environment is 0.1% by mass or more, the solvent does not evaporate excessively, so cracking or the like is unlikely to occur in the coating film. If the solvent concentration is 0.3% by mass or less, it is easy to appropriately increase the evaporation rate of the solvent from the coating film, and therefore it is easy to cause the rubber particles to be concentrated on the surface. The solvent concentration in the environment can be adjusted by the drying temperature and the dew point temperature in the drying oven. In addition, the solvent concentration in the environment can be measured with an infrared gas concentration meter.

The laminated system of this embodiment may be belt-shaped as described above. Therefore, the manufacturing method of the laminated body of this embodiment preferably further includes (4) the step of winding the belt-shaped laminated body into a roll shape to form a roll body.

Regarding the step (4) (winding the laminate to obtain the roll body) The obtained belt-shaped laminated body was wound into a roll shape in the direction orthogonal to the width direction, and it became a roll body.

The length of the belt-like laminate is not particularly limited, but it may be, for example, about 100 to 10,000 m. In addition, the width of the belt-shaped laminate is preferably 1 m or more, more preferably 1.3 to 4 m.

[Manufacturing Equipment] The manufacturing method of the laminated body of this embodiment can be performed by the manufacturing apparatus shown in FIG. 2, for example.

Fig. 2 is a model diagram of a manufacturing apparatus 200 for implementing a method of manufacturing a laminate according to an embodiment of the present invention. The manufacturing apparatus 200 has a supply unit 210, a coating unit 220, a drying unit 230, a cooling unit 240, and a winding unit 250. a to d indicate the conveyance rollers of the conveyance support 110.

The supply unit 210 has a delivery device (not shown) that delivers the roll body 201 of the belt-shaped support 110 wound on the winding core.

The coating section 220 is a coating device. It has a support roller 221 that holds the support 110, a coating head 222 that coats the transparent resin layer solution on the support 110 held by the support roller 221, and the coating head A decompression chamber 223 provided on the upstream side of 222.

The flow rate of the solution for the translucent resin layer discharged from the coating head 222 can be adjusted by a pump (not shown). The flow rate of the solution for the translucent resin layer discharged from the coating head 222 is set to be able to stably form a coating layer with a specified thickness when the coating head 222 is continuously coated under the conditions of the coating head 222 adjusted in advance. the amount.

The decompression chamber 223 is a mechanism for stabilizing the beads (retention of the coating liquid) formed between the solution for the translucent resin layer from the coating head 222 and the support 110 during coating. Pressure degree. The decompression chamber 223 is connected to a decompression blower (not shown), and can decompress the inside. The decompression chamber 223 is in a state where there is no air leakage, and the gap with the support roller is also adjusted narrowly, so that stable coating liquid beads can be formed.

The drying unit 230 is a drying device that dries the coating film applied on the surface of the support 110, and has a drying chamber 231, an inlet 232 for drying gas, and an outlet 233. The temperature and the air volume of the drying wind can be appropriately determined according to the type of the coating film and the type of the support 110. By setting conditions such as the temperature, air volume, and drying time of the drying air in the drying section 230, the residual solvent content of the coating film after drying can be adjusted. The residual solvent amount of the dried coating film can be measured by comparing the unit mass of the dried coating film with the mass after the coating film is fully dried.

The cooling unit 240 cools the temperature of the support 110 having the coating film (translucent resin layer 120) dried by the drying unit 230 and adjusts it to an appropriate temperature. The cooling unit 240 has a cooling chamber 241, a cooling air inlet 242 and a cooling air outlet 243. The temperature and air volume of the cooling air can be appropriately determined according to the type of the coating film and the type of the support 110. In addition, when the appropriate cooling temperature can be achieved without providing the cooling unit 240, the cooling unit 240 may not be provided.

The winding part 250 is a winding device (not shown) for winding the support body 110 (laminated body 100) on which the light-transmitting resin layer 120 is formed to obtain a roll body 251.

3. Polarizing plate The polarizing plate has a polarizer and a translucent resin layer arranged on at least one surface thereof. The polarizer and the translucent resin layer are preferably adhered via an adhesive layer.

FIG. 3 is a cross-sectional view of a polarizing plate 300 according to an embodiment of the present invention.

As shown in FIG. 3, the polarizing plate 300 of this embodiment has a polarizer 310 (polarizer), a translucent resin layer 120 (protective film) arranged on one side, and a protective film 320 (other protective film) arranged on the other side. ), and two adhesive layers 330 (adhesive layers) arranged between the translucent resin layer 120 or the protective film 320 and the polarizer 310.

In addition, the polarizing plate 300 may further have an adhesive layer 340 arranged on the surface of the translucent resin layer 120 opposite to the polarizer 310. The adhesive layer 340 is a layer for attaching the polarizing plate 300 to a display element (not shown) such as a liquid crystal cell. The surface of the adhesive layer 340 is usually protected by a release film (not shown).

3-1. Polarizing lens The polarizer is an element that only passes the light of the polarization plane in a certain direction. The polarizer can usually be a polyvinyl alcohol-based polarizing film. Examples of polyvinyl alcohol-based polarizing films include those dyed with iodine or dichroic dyes.

The polyvinyl alcohol-based polarizing film can be a polyvinyl alcohol-based film that is uniaxially stretched and then dyed with iodine or a dichroic dye (preferably a film that has been subjected to durability treatment with a boron compound); or The polyvinyl alcohol-based film is dyed with iodine or a dichroic dye and then uniaxially stretched (preferably, a film that has been subjected to durability treatment with a boron compound). The absorption axis of the polarizer is usually parallel to the maximum extension direction.

The thickness of the polarizer is preferably 5 to 30 μm, and from the viewpoint of reducing the thickness of the polarizing plate, it is more preferably 5 to 20 μm.

3-2. Translucent resin layer and other protective films On at least one surface of the polarizer, a translucent resin layer is arranged. The light-transmitting resin layer transfers the light-transmitting resin layer of the aforementioned laminate to the surface of the polarizer, and can function as a protective film. In this embodiment, a translucent resin layer is arranged on one surface of the polarizer, and another protective film is arranged on the other surface.

Examples of other protective films include (meth)acrylic resins, polyester resins, cycloolefin resins, and cellulose ester resins, preferably (meth)acrylic resins and polyester resins.

3-3. Adhesive layer The adhesive layer is respectively arranged between the translucent resin layer and the polarizer and between the other protective film and the polarizer. The adhesive layer arranged between the translucent resin layer and the polarizer may be the same or different from the adhesive layer arranged between the other protective film and the polarizer.

The adhesive layer may be a layer obtained from a fully saponified polyvinyl alcohol aqueous solution (water paste), or may be a cured product layer of an active energy ray-curable adhesive. From the viewpoint of high affinity with the translucent resin layer and easy adhesion, the adhesive layer is preferably a cured layer of an active energy ray-curable adhesive.

The active energy ray curable adhesive may be a photo-radical polymerizable composition or a photocationically polymerizable composition. Among them, a photocationically polymerizable composition is preferred.

The photocationic polymerizable composition contains an epoxy compound and a photocationic polymerization initiator.

The epoxy compound is a compound having one or more, preferably two or more epoxy groups in the molecule. Examples of epoxy compounds include hydrogenated epoxy compounds obtained by reacting epichlorohydrin with alicyclic polyols (glycidyl ethers of alicyclic ring polyols); aliphatic Aliphatic epoxy compounds such as polyol or its alkylene oxide adducts such as polyglycidyl ether; alicyclic epoxy having more than one epoxy group bonded to the alicyclic ring in the molecule Department of compounds. The epoxy compound system may use only 1 type, and may use 2 or more types together.

The photocationic polymerization initiator may be, for example, an aromatic diazonium salt; an onium salt such as an aromatic iodonium salt or an aromatic sulfonium salt; an iron-aromatic hydrocarbon complex, and the like.

The photocationic polymerization initiator may further include cationic polymerization accelerators such as oxetane and polyols, photosensitizers, ion traps, antioxidants, chain transfer agents, tackifiers, thermoplastic resins, Additives such as fillers, flow regulators, plasticizers, defoamers, antistatic agents, leveling agents, solvents, etc.

The thickness of the adhesive layer is not particularly limited, but each is preferably 0.01 to 10 μm, more preferably 0.01 to 5 μm.

3-4. Adhesive layer The adhesive layer is a layer for bonding the polarizing plate and the display element such as the liquid crystal cell, and can be arranged on the surface of the translucent resin layer on the opposite side of the polarizer.

The adhesive layer is preferably one obtained by drying and partially crosslinking an adhesive composition including a base polymer, a prepolymer and/or a crosslinkable monomer, a crosslinking agent, and a solvent. That is, at least a part of the adhesive composition may be cross-linked.

In the example of the adhesive composition, it includes an acrylic adhesive composition with a (meth)acrylic polymer as the base polymer, and a silicone adhesive composition with a silicone polymer as the base polymer It is a rubber-based adhesive composition with rubber as the base polymer. Among them, from the viewpoints of transparency, weather resistance, heat resistance, and processability, an acrylic adhesive composition is preferred.

The (meth)acrylic polymer contained in the acrylic adhesive composition may be a copolymer of alkyl (meth)acrylate and a monomer containing a functional group that can be crosslinked with a crosslinking agent.

The alkyl (meth)acrylate is preferably an alkyl acrylate having 2 to 14 carbon atoms in the alkyl group.

Examples of monomers containing functional groups that can be crosslinked with a crosslinking agent include monomers containing amide groups, monomers containing carboxyl groups (acrylic acid, etc.), and monomers containing hydroxyl groups (hydroxyethyl acrylate, etc.) .

Examples of the crosslinking agent contained in the acrylic adhesive composition include epoxy-based crosslinking agents, isocyanate-based crosslinking agents, peroxide-based crosslinking agents, and the like. The content of the crosslinking agent in the adhesive composition is usually 0.01-10 parts by mass relative to 100 parts by mass of the base polymer (solid content).

If necessary, the adhesive composition may further include tackifiers, plasticizers, glass fibers, glass beads, metal powders, other fillers, pigments, colorants, fillers, antioxidants, ultraviolet absorbers, silane coupling agents, etc. Various additives.

The thickness of the adhesive layer is usually about 3-100 μm, preferably 5-50 μm.

The surface of the adhesive layer is protected by a release film applied with mold release treatment. In the example of the release film, plastic films such as acrylic film, polycarbonate film, polyester film, and fluororesin film are included.

4. Manufacturing method of polarizing plate The polarizing plate of this embodiment can be manufactured through the steps of laminating the translucent resin layer of the aforementioned laminate on at least one surface of the polarizer, and peeling off the support at the same time. The bonding of the light-transmitting resin layer can be performed on only one side of the polarizer, or on both sides. From the viewpoint of transmittance, it is preferable to laminate the light-transmitting resin layer on one side of the polarizer, and on the other side. Laminate the other protective film on one side.

That is, the polarizing plate can be manufactured through the following steps: (1) On one surface of the polarizer, the light-transmitting resin layer of the above-mentioned laminate is attached, and at the same time, the light-transmitting resin layer is placed on the opposite side of the polarizer. The step of peeling off the support configured above, and (2) the step of attaching other protective films on the other side of the polarizer.

Regarding the step (1) (the bonding step of the translucent resin layer), On one surface of the polarizer, the translucent resin layer of the above-mentioned laminate was bonded via an adhesive. The surface of the pasted translucent resin layer or the surface on one side of the polarizer may be subjected to pretreatment such as corona treatment if necessary.

For example, when an active energy ray-curable adhesive is used as the adhesive, the surface of the light-transmitting resin layer of the laminate may be subjected to surface treatment such as corona treatment as necessary. Then, on one surface of the polarizer, the light-transmitting resin layer of the laminate is laminated via the active energy ray curable adhesive, and then the support arranged on the side of the light-transmitting resin layer opposite to the bonding surface The body is peeled off. Next, the exposed light-transmitting resin layer is irradiated with active energy rays to harden the active energy ray curable adhesive. Therefore, the polarizer and the translucent resin layer are bonded together via the cured product layer of the active energy ray curable adhesive.

About the step of (2) (the bonding step of the protective film) In addition, on the other side of the polarizer, another protective film is attached. Specifically, for the surface of other protective films, surface treatment such as corona treatment is required. Next, after laminating the protective film on the other side of the polarizer through an active energy ray curable adhesive, the active energy ray is irradiated to harden the active energy ray curable adhesive. Therefore, the polarizer and the other protective film are bonded to each other through the cured material layer of the active energy ray curable adhesive.

The steps (1) and (2) can be carried out simultaneously or successively. From the viewpoint of improving manufacturing efficiency, the steps (1) and (2) are preferably performed simultaneously.

In addition, the manufacturing method of the polarizing plate of this embodiment may further have the step of (3) forming an adhesive layer after the step (2) if necessary.

Regarding the step (3) (the step of forming an adhesive layer) Next, the adhesive layer and its release film were further bonded to the surface of the translucent resin layer of the obtained laminate on the side opposite to the polarizer. Specifically, the adhesive layer can be formed by a method such as transferring a release film provided with an adhesive layer on the translucent resin layer.

Furthermore, the polarizing plate of this embodiment may be in the shape of a strip. Therefore, the steps (1) and (2) are preferably to roll out the light-transmitting resin layer of the belt-shaped laminate, the belt-shaped polarizer, and the belt-shaped other protective film (opposing film) from the roll body. , Carried out by roll-to-roll bonding.

Moreover, it is preferable to further perform the step of (4) winding the strip-shaped polarizing plate into a roll shape to form a roll body. In this step, the length or width of the strip-shaped polarizing plate is the same as the length or width of the strip-shaped laminate in the step (4) of the manufacturing method of the laminate.

5. Display device The display device of this embodiment has a display element such as a liquid crystal cell or an organic EL element, and a polarizing plate manufactured by the above-mentioned manufacturing method. Among them, the display device of this embodiment is preferably a liquid crystal display device having a liquid crystal cell and a polarizing plate manufactured by the above-mentioned manufacturing method.

That is, the liquid crystal display device includes a liquid crystal cell, a first polarizing plate arranged on one side of the liquid crystal cell, and a second polarizing plate arranged on the other side of the liquid crystal cell. Moreover, at least one of the first polarizing plate and the second polarizing plate is the polarizing plate of this embodiment.

The display mode of the liquid crystal cell can be STN (Super- Twisted Nematic, TN (Twisted Nematic), OCB (Optically Compensated Bend), HAN (Hybridaligned Nematic), VA (Vertical Alignment), MVA (Multi-domain Vertical Alignment, multi-domain vertical alignment), PVA (Patterned Vertical Alignment, patterned vertical alignment), IPS (In-Plane- Switching, in-plane switching) and so on. For example, in a liquid crystal display device for portable equipment, the IPS mode is preferred.

The first polarizer is arranged on the surface of the liquid crystal cell on the visually recognizable side through the adhesive layer. The first polarizing plate includes a first polarizer, a protective film (F1) arranged on the surface of the first polarizer on the visible side of the first polarizer, and a protective film (F2) arranged on the surface of the liquid crystal cell side of the first polarizer. ), and two adhesive layers arranged between the first polarizer and the protective film (F1) and between the first polarizer and the protective film (F2).

The second polarizing plate is arranged on the backlight side of the liquid crystal cell through the adhesive layer. The second polarizing plate includes a second polarizer, a protective film (F3) arranged on the surface of the second polarizer on the liquid crystal cell side, a protective film (F4) arranged on the surface of the second polarizer on the backlight side, And two adhesive layers arranged between the second polarizer and the protective film (F3) and between the second polarizer and the protective film (F4).

The absorption axis of the first polarizer and the absorption axis of the second polarizer are preferably orthogonal (to be crossed Nicols).

In addition, at least one of the first polarizing plate and the second polarizing plate is the polarizing plate of this embodiment. That is, when the first polarizing plate is the aforementioned polarizing plate, the protective film (F1) is the protective film 320 of FIG. 3, the protective film (F2) is the translucent resin layer 120 of FIG. 3, and the adhesive layer may be the one of FIG. 3. Adhesive layer 340. Similarly, when the second polarizing plate is the aforementioned polarizing plate, the protective film (F4) is the protective film 320 of FIG. 3, the protective film (F3) is the translucent resin layer 120 of FIG. 3, and the adhesive layer may be as shown in FIG. 3. The adhesive layer 340. [Example]

Hereinafter, the present invention will be explained in more detail through examples, but the present invention is not limited by these.

1. Laminated material 1-1. Support ＜PET-1＞ A polyethylene terephthalate film (TZ200 manufactured by Toyobo Co., Ltd., with a release layer (containing a silicone-based release agent, thickness 50 μm)) was used.

＜PET-2＞ A polyethylene terephthalate film (TN100 manufactured by Toyobo Co., Ltd., with a release layer (containing non-polysiloxane release agent, thickness 50μm)) was stretched 50% in the TD direction at 140°C (additional stretch) .

＜PET-3＞ A polyethylene terephthalate film (TN100 manufactured by Toyobo Co., Ltd., with a release layer (containing a non-polysiloxane release agent, thickness 50μm)) was stretched at 140°C in the TD direction and MD direction by 50% each (Additional extension).

＜TAC＞ Cellulose triacetate film (KC4UA manufactured by Konica-Minolta, no release layer, thickness 40 μm).

＜COP＞ Cycloolefin resin film (RX4500 manufactured by JSR Corporation, no release layer, thickness 50 μm).

＜HDPE＞ High-density polyethylene film (thickness 50μm)

The tensile elastic modulus G1 of these supports was measured by the following method.

(Tensile elastic modulus G1) Cut out 1cm×10cm from the support and use it as a sample, and adjust the humidity for 24 hours under an environment of 25°C and 60%RH. Then, the tensile modulus of the obtained sample was measured by the tensile test method described in JIS K7127. Specifically, the sample is set in a tensile testing device, a universal testing machine (Tensilon) manufactured by ORIENTEC Corporation, and the tensile elastic modulus is measured when the tensile test is performed under the conditions of a distance between chucks of 50.0 mm and a tensile speed of 50 mm/min. number. The measurement is performed at 25°C and 60%RH. Moreover, the measurement of the tensile modulus of elasticity is carried out in both the MD direction and the TD direction. The average value of the tensile modulus of elasticity in the MD direction and the tensile modulus of the TD direction is regarded as the "tensile modulus of G1".

1-2. Solution for translucent resin layer (1) Preparation of materials ＜Resin＞ Resin 1: PMMA, Mw: 1 million, Tg: 109°C Resin 2: MMA/PMI/MA copolymer (85/10/5 mass ratio), Mw: 1 million, Tg: 122°C Resin 3: MMA/PMI/MA copolymer (85/10/5 mass ratio), Mw: 2 million, T: 122°C Resin 4: MMA/PMI/MA copolymer (50/25/25 mass ratio), Mw: 1 million, Tg: 134°C Resin 5: MMA/PMI/MA copolymer (85/10/5 mass ratio), Mw: 500,000, Tg: 122°C Furthermore, the abbreviation means the following. MMA: methyl methacrylate PMI: Phenylmaleimide MA: methyl acrylate

The glass transition temperature and weight average molecular weight of resins 1 to 5 were measured by the following methods.

(Glass transition temperature) The glass transition temperature (Tg) of the resin uses DSC (Differential Scanning Colorimetry: Differential scanning calorimetry), based on JIS K7121-2012 is measured.

(Weight average molecular weight) The weight average molecular weight (Mw) of the resin is based on a gel permeation chromatograph (HLC8220GPC manufactured by Tosoh Corporation) and a column (tandem TSK-GEL G6000HXL-G5000HXL-G5000HXL-G4000HXL- manufactured by Tosoh Corporation). G3000HXL) for measurement. 20 mg±0.5 mg of the sample was dissolved in 10 ml of tetrahydrofuran, and filtered with a 0.45 mm filter. 100 ml of this solution was injected into the column (temperature 40°C), and the measurement was performed at a detector RI temperature of 40°C, and a value converted from styrene was used.

＜Rubber particles＞ The rubber particles R1 prepared by the following method are used. Add the following materials to the 8L polymerization device with agitator. Deionized water 180 parts by mass Polyoxyethylene lauryl ether phosphoric acid 0.002 parts by mass Boric acid 0.4725 parts by mass Sodium carbonate 0.04725 parts by mass Sodium hydroxide 0.0076 parts by mass After fully replacing the inside of the polymerization machine with nitrogen, the internal temperature was set to 80°C, and 0.021 parts by mass of potassium persulfate was added as a 2% aqueous solution. Next, the monomers composed of 84.6% by mass of methyl methacrylate, 5.9% by mass of butyl acrylate, 7.9% by mass of styrene, 0.5% by mass of allyl methacrylate, and 1.1% by mass of n-octyl mercaptan were added. A mixed solution of 0.07 parts by mass of polyoxyethylene lauryl ether phosphoric acid was added to 21 parts by mass of the mixture (c'), and it was continuously added to the above solution for 63 minutes. Furthermore, by continuing the polymerization reaction for 60 minutes, the innermost hard polymer (c) was obtained.

Then, 0.021 parts by mass of sodium hydroxide as a 2% by mass aqueous solution and 0.062 parts by mass of potassium persulfate as a 2% by mass aqueous solution were added separately. Next, 39 parts by mass of a monomer mixture (a') composed of 80.0% by mass of butyl acrylate, 18.5% by mass of styrene, and 1.5% by mass of allyl methacrylate were added with polyoxyethylene lauryl ether phosphoric acid. 0.25 parts by mass of the mixed solution was added continuously for 117 minutes. After the addition, 0.012 parts by mass of potassium persulfate was added as a 2% by mass aqueous solution, and the polymerization reaction was continued for 120 minutes to obtain a soft layer (a layer made of an acrylic rubber-like polymer (a)). The glass transition temperature (Tg) of the soft layer is -30°C. The glass transition temperature of the soft layer is calculated by averaging the glass transition temperature of the homopolymer of each monomer constituting the acrylic rubber-like polymer (a) in accordance with the composition ratio.

Then, 0.04 parts by mass of potassium persulfate was added as a 2% by mass aqueous solution, and 26.1 parts by mass of the monomer mixture (b') composed of 97.5% by mass of methyl methacrylate and 2.5% by mass of butyl acrylate was added continuously for 78 minutes. Add to. The polymerization reaction was continued for 30 minutes to obtain polymer (b).

Put the obtained polymer into a 3% by mass sodium sulfate warm aqueous solution to salt out and solidify. Next, after repeating dehydration and washing, it was dried to obtain acrylic graft copolymer particles (rubber particles R1) having a three-layer structure. The average particle diameter of the resulting rubber particles R1 was 200 nm.

The average particle diameter of the rubber particles is measured by the following method.

(The average particle size) A zeta potential and particle size measurement system (ELSZ-2000ZS manufactured by Otsuka Electronics Co., Ltd.) was used to measure the dispersed particle size of the rubber particles in the resulting dispersion.

(2) Preparation of solution for translucent resin layer <Production of Solution 101 for Translucent Resin Layer> The following components are mixed to obtain a solution for a translucent resin layer. Acetone (ketones): 1012.5 parts by mass Methanol (alcohols): 112.5 parts by mass Resin 1 ((meth)acrylic resin): 100 parts by mass Rubber particles: 25 parts by mass

＜Preparation of solution 102～109 for translucent resin layer＞ Except having changed to the composition shown in Table 1, it carried out similarly to the solution 101 for translucent resin layers, and obtained the solutions 102-109 for translucent resin layers.

Table 1 shows the composition and viscosity of the obtained solutions 101 to 109 for the translucent resin layer. In addition, the viscosity of the solution for the light-transmitting resin layer at 25°C was measured with a Toki Sangyo Co., Ltd. E-type viscometer.

2. Production and evaluation of laminated body ＜Production of laminated body 201＞ As a support, a PET film (TN100 manufactured by Toyobo Co., Ltd., thickness 50 μm, with a release layer containing a non-silicone-based release agent, PET-1 in the table) was prepared. On the release layer of this PET film, the translucent resin layer solution 101 was coated with a die by the back coating method, and then dried at 80°C in an environment with a solvent concentration of 0.18% to form a thickness of 10μm The light-transmitting resin layer of, and the laminated body 201 was obtained.

<Making of laminated bodies 202-203, 205, 210, 212, 213, 216, 217, and 219> Except having changed the kind of the solution for the light-transmitting resin layer as shown in Table 2, laminates 202 to 203, 205, 210, 212, 213, 217, and 219 were obtained in the same manner as the laminate 201.

＜Production of laminated body 204＞ Except that the solvent concentration of the environment was changed to be as shown in Table 2, a laminated body 204 was obtained in the same manner as in the laminated body 202.

＜Production of laminated body 211 and 214＞ Except that the type of support body was changed to that shown in Table 2, laminated bodies 211 and 214 were obtained in the same manner as the laminated body 202.

＜Production of laminated body 215 and 218＞ Except having changed the thickness of the light-transmitting resin layer to be as shown in Table 2, laminates 215 and 218 were obtained in the same manner as laminate 202.

＜Evaluation＞ The following methods were used to evaluate the distribution of rubber particles in the translucent resin layer of the obtained laminates 201 to 219, the tensile elastic modulus G of the laminate, the transport stability, and the winding deformation of the polarizing plate.

[Distribution of rubber particles] The following methods, distribution (R _A / R _B) of the rubber particles of the translucent resin layer was measured in the laminate. (1) Cut the laminated body with a microtome, and observe the cut surface perpendicular to the surface of the translucent resin layer by TEM. The observation conditions are set as acceleration voltage: 30kV, working distance: 8.6mm×magnification: 3.00k. The observation area is an area including the entire thickness direction of the translucent resin layer. (2) After removing the brightness gradient of the obtained TEM image using image processing software of NiVision (manufactured by National Instruments), the cut-off process is performed to detect the contrast difference between the bulk and the rubber particles. Thus, the distribution state of rubber particles is defined. (3) In the image after the image processing obtained in (2) above, in the thickness direction of the light-transmitting resin layer, calculate the thickness of the light-transmitting resin layer from the opposite side of the support to 20% or less. per unit area of the area ratio of rubber particles in region a R _a, the support side of the light-transmitting resin layer from the surface area ratio of rubber particles per unit area of the region B 20% less of the thickness of the R _B. (4) From the results of (3) obtained from the above calculated rubber particles of area A per unit area of the area ratio R _A per unit area of the area ratio of rubber particles in the region B than the _B of R & lt (R _A /R _B ).

[Tensile modulus of elasticity] As for the laminate, a tensile test was performed in accordance with JIS K7127 in the same manner as described above. That is, 1 cm (TD direction)×10 cm (MD direction) was cut out from the laminate and used as a sample, and the humidity was adjusted for 24 hours in an environment of 25° C. and 60% RH. The obtained sample was set in a universal testing machine manufactured by ORIENTEC Corporation, a tensile testing device, and a tensile test was performed to measure the tensile elastic modulus G (the tensile elastic modulus of the laminate). The measurement conditions are also the same as those described above (the distance between the chucks is 50.0 mm, the stretching speed is 50 mm/min, and at 25° C. and 60% RH).

Furthermore, regarding the light-transmitting resin layer, after peeling the light-transmitting resin layer from the support, the tensile modulus G2 of the light-transmitting resin layer was measured by the same method as described above.

[Transportation stability] The transport stability of the laminate was evaluated by applying a transport tension of 350 N/m while confirming whether there were breaks or breaks when transported by rollers in the production line. Then, evaluate the transportation stability based on the following criteria. ◎: The translucent resin layer does not break and can be transported ○: Cracks occur in the light-transmitting resin layer, but can be transported without breaking ○△: Very small scratches and cracks occur in the translucent resin layer, but it can be transported △: Tiny scratches and cracks occur in the translucent resin layer, but it can be transported ×: The light-transmitting resin layer is cracked or broken If △ or more, it is judged to be good.

[Laminated body winding deformation defect] The obtained roll body was stored in a constant temperature bath at 40°C and 90%RH for 8 days. Then, the roll body was taken out of the thermostatic bath, and the appearance of the roll body was evaluated, specifically, whether the roll body had a depression or other winding deformation such as a depression in the center portion in the width direction of the roll body. Then, the winding deformation was evaluated based on the following criteria. ◎: No deformation of winding shape ○: There are some deformations of the winding shape, but it is at a level that can be used, and there is no sticking ○△: There are some deformations of the winding shape, and some sticking is seen, but it is a level that can be used △: There are some deformation or sticking of the winding shape, but it is a level that can be used ×: The deformation of the winding shape is significant, which is an unusable level If △ or more, it is judged to be good.

[Wound deformation defect of polarizing plate] (Making of polarizer) Swell a polyvinyl alcohol-based film with a thickness of 25 μm with water at 35°C. The resulting film was immersed in an aqueous solution of 0.075 g of iodine, 5 g of potassium iodide, and 100 g of water for 60 seconds, and then immersed in an aqueous solution of 3 g of potassium iodide, 7.5 g of boric acid, and 100 g of water for 60 seconds. The resulting film was stretched uniaxially under the conditions of a stretching temperature of 55°C and a stretching ratio of 5 times. After washing the uniaxially stretched film with water, it was dried to obtain a polarizer with a thickness of 12 μm.

(Preparation of UV curable adhesive composition) After mixing the following components, defoaming is performed to prepare an ultraviolet curable adhesive composition. 3,4-Epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate: 45 parts by mass Epolead GT-301 (alicyclic epoxy resin manufactured by DAICEL): 40 parts by mass 1,4-Butanediol diglycidyl ether: 15 parts by mass Triaryl hexafluorophosphate: 2.3 parts by mass (solid content) 9,10-Dibutoxyanthracene: 0.1 parts by mass 1,4-diethoxynaphthalene: 2.0 parts by mass Furthermore, the triarylsulfonium hexafluorophosphate is blended as a 50% propylene carbonate solution.

(Making of polarizing plate) The surface of the translucent resin layer of the laminate produced above was subjected to corona discharge treatment at a corona output intensity of 2.0 kW and a linear velocity of 18 m/min. Similarly, as another protective film (a facing film), triacetyl cellulose (thickness 25 μm) was prepared, and the surface was subjected to corona treatment under the same conditions as above.

Then, on one side of the polarizer produced above, a light-transmitting resin layer was pasted through a 3μm-thick ultraviolet curable adhesive layer, and on the other side, a 3μm-thick UV curable adhesive layer was pasted. Other protective films, to obtain laminates. The bonding was performed so that the absorption axis of the polarizer and the slow axis of the protective film became orthogonal.

Next, the obtained laminate was irradiated with ultraviolet rays so that the ^{accumulated light quantity became 750mJ/cm 2} by using an ultraviolet irradiation device with a conveyor belt (the lamp was a D bulb manufactured by FUSION UV Systems Co., Ltd.) to make the ultraviolet curable adhesion The agent layer was cured to obtain a roll body of the polarizing plate 201 having a laminated structure of a facing film/adhesive layer/polarizer/adhesive layer/translucent resin layer with a length of 3000 m and a width of 1.5 m.

(Winding deformation defect) The winding deformation defects of the obtained reel were evaluated by the same method and criteria as the winding deformation defects of the reel of the laminate.

Table 2 shows the production conditions of the obtained laminates 201 to 219, and Table 3 shows the evaluation results. Furthermore, in Table 2, 80°C of ketone/alcohol (90/10 mass ratio) is equivalent to about Tb°C, 40°C of ketone/alcohol (10/90 mass ratio) is equivalent to about Tb-40°C, ethyl acetate The 110°C is equivalent to Tb+30°C.

As shown in Table 3, it can be seen that the laminates 201 to 210 and 215 to 219 do not break during transportation and have good transportation stability. In addition, it can be seen that even if the laminates 201-210 and 215-219 are wound into a roll shape and stored for a certain period of time, the winding deformation is less likely to remain in the translucent resin layer, and the winding storage stability is also excellent. In addition, it can be seen that the roll body of the polarizing plate obtained by using such a laminate does not easily remain in the translucent resin layer even if it is stored for a certain period of time.

In addition, it can be seen that by increasing the weight average molecular weight of the (meth)acrylic resin, the winding deformation can be further reduced (comparison of laminate 202 and 203).

In addition, it can be seen that if the drying temperature is increased, rubber particles tend to be eccentrically present in the surface layer (comparison of laminates 202 and 209). It is believed that this is because the drying speed becomes higher. In addition, it can be seen that by setting the ratio of acetone to methanol to be rich in acetone, rubber particles tend to be eccentrically present on the surface layer (comparison of laminates 202 and 210). It is believed that this system is because the drying speed becomes higher, and because the affinity of acetone and rubber particles is high, the rubber particles tend to move together with the solvent.

On the other hand, it can be seen that the laminated body 211 with an excessively high tensile modulus of the support body is easily broken, and the transport stability is poor. On the other hand, it can be seen that the laminate 214 having an excessively low tensile elastic modulus of the support is prone to winding deformation of the laminate, and therefore the deformation is easily transferred to the translucent resin layer. Furthermore, it can be seen that the laminated body 213 in which the light-transmitting resin layer does not contain rubber particles does not easily disappear due to winding deformation. In addition, it can be seen that the laminated body 212 with a low molecular weight of the resin contained in the light-transmitting resin layer is likely to break when the light-transmitting resin layer is transported, and the transport stability is low.

This application claims to be filed on November 1, 2019 Priority based on PCT/JP2019/043116. The contents recorded in the description of the application and the drawings are all quoted in the description of the case. [Industrial Utilization Possibility]

According to the present invention, it is possible to provide a layer that can suppress surface defects caused by winding deformation when the laminate or polarizing plate is wound into a roll and stored for a certain period of time while suppressing breakage during transportation of the laminate A composite body, a manufacturing method thereof, and a manufacturing method of a polarizing plate using the laminate body.

100: laminated body 110: Support 120: Translucent resin layer 200: Manufacturing device 210: Supply Department 220: Coating Department 230: Dry Section 240: Cooling part 250: Coiling section 300: Polarizing plate 310: Polarizer 320: Protective film (other protective films) 330: Adhesive layer 340: Adhesive layer

[Fig. 1] is a cross-sectional view of a laminate showing an embodiment of the present invention. [Fig. 2] is a model diagram of a manufacturing apparatus for implementing a method of manufacturing a laminate according to an embodiment of the present invention. Fig. 3 is a cross-sectional view of a polarizing plate showing an embodiment of the present invention.

100: laminated body

110: Support

120: Translucent resin layer

Claims (13)

A laminate having a support and a light-transmitting resin layer releasably arranged on the surface of the support, The aforementioned light-transmitting resin layer contains (meth)acrylic resin having a weight average molecular weight of 1 million or more and rubber particles, The tensile elastic modulus of the aforementioned laminate at 25°C is 2.0 to 6.0 GPa. The laminate of claim 1, wherein the (meth)acrylic resin contains 50 to 95% by mass of a structure derived from methyl methacrylate relative to all the structural units constituting the (meth)acrylic resin Unit, a copolymer of 1-25% by mass of structural units derived from phenylmaleimide and 1-25% by mass of structural units derived from alkyl acrylate. The laminate of claim 1 or 2, wherein in the cross section of the light-transmitting resin layer, the surface of the light-transmitting resin layer opposite to the support is raised to 20% of the thickness of the light-transmitting resin layer The following area is referred to as area A, and the area of 20% or less of the thickness of the light-transmitting resin layer from the surface of the support side of the light-transmitting resin layer is taken as area B, and the rubber in the above-mentioned area A when the area ratio per unit area of the particles as R _a, per unit area of the area ratio of rubber particles in as region B R _B, R _a / R _B is 1.0 to 1.1. Such as the laminated body of claim 3, where R _A /R _B is 1.05 to 1.1. The laminate according to any one of claims 1 to 4, wherein the content of the rubber particles in the light-transmitting resin layer is 5-40% by mass relative to the light-transmitting resin layer. The laminate according to any one of claims 1 to 5, wherein the thickness of the translucent resin layer is 0.1 to 35 μm. The laminate according to any one of claims 1 to 6, wherein the support includes a film containing a polyester resin, a cellulose ester resin, or a cycloolefin resin. A method for manufacturing a laminated body, which has: The step of obtaining a solution for a translucent resin layer containing a (meth)acrylic resin having a weight average molecular weight of 1 million or more, rubber particles, and a solvent, The step of applying the aforementioned solution for the translucent resin layer to the surface of the support, and The step of removing the solvent from the provided solution for the translucent resin layer to form a translucent resin layer, and obtaining a laminate having a tensile modulus of elasticity of 2.0 to 6.0 GPa at 25°C. The method for producing a laminate according to claim 8, wherein the (meth)acrylic resin contains 50 to 95% by mass of methyl methacrylate relative to all the structural units constituting the (meth)acrylic resin. A copolymer of ester structural units, 1-25% by mass of phenylmaleimide-derived structural units and 1-25% by mass of alkyl acrylate-derived structural units. The method for producing a laminate according to claim 8 or 9, wherein the aforementioned solvent contains ketones and alcohols. The method for manufacturing a laminate according to any one of claims 8 to 10, wherein in the step of forming the aforementioned light-transmitting resin layer, When the boiling point of the solvent is regarded as Tb (°C), the solution for the translucent resin layer that has been applied to the surface of the support is dried at a temperature of (Tb-50) to (Tb+50)°C. The method for producing a laminate according to any one of claims 8 to 11, wherein the thickness of the translucent resin layer is 0.1 to 35 μm. A method for manufacturing a polarizing plate, which has the aforementioned translucent resin layer of the laminate of any one of claims 1 to 7 attached to at least one surface of the polarizer, and peeling off the aforementioned translucent resin layer The step of the support body arranged on the surface opposite to the polarizer.

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