JP2018051894A - Laminated film and polarizing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated film which can maintain adhesion even after long-term use and can be preserved as a film roll in a good condition and to provide a polarizing plate which can be easily produced and has high durability.SOLUTION: There are provided: a laminated film which comprises a conductive hard coat layer, a base material layer and an urethane resin layer in this order, wherein the base material layer is a thermoplastic resin layer having an ultraviolet absorbing function; and a polarizing plate which comprises the laminated film and a polarizer layer provided on the surface of the urethane resin layer side of the laminated film through an adhesive layer.SELECTED DRAWING: None

Description

  The present invention relates to a laminated film and a polarizing plate, and more particularly to a laminated film having a conductive layer and usable for optical applications and a polarizing plate provided with the laminated film.

  An optical display device such as a liquid crystal display device or an organic electroluminescence display device may be provided with a film having various functions as a part of a layer constituting the display surface. Examples of such functions include various functions such as a function for protecting the device surface and a function as a retardation layer. As an example of a film that protects the surface of the apparatus, a hard coat film including a resin base layer and a hard coat layer provided on the surface is known. In forming such a hard coat layer, it is known that a primer layer is first provided on the surface of the base material layer, and a hard coat layer is provided thereon (see, for example, Patent Document 1). In addition, it has also been proposed to employ a conductive hard coat layer, that is, a hard coat layer containing a conductive material to impart a function of preventing the display device from being charged.

  In the production of a film, it is generally performed that a long film is continuously formed and stored and transported as a wound film roll, and the film is unwound from the film roll at the time of use. When the film is a film roll, the front surface and the back surface of the film come into contact with each other with a high pressure, so that a phenomenon occurs in which the films adhere to each other, and the film can be wound poorly. Such a phenomenon is called blocking. As a measure for preventing problems such as blocking when the film is made into a film roll, for example, it is known to provide an anti-blocking layer having irregularities on the surface of the film (see, for example, Patent Document 2).

JP 2004-284158 A International Publication No. 2015/147013

  When the primer layer is provided on the base material layer and the conductive hard coat layer is provided thereon, the adhesion between the base material layer and the conductive hard coat layer is expected to be improved. By adopting such a configuration, sufficient adhesion may not be obtained, and conversely, adhesion may be reduced. In particular, in actual use of the apparatus, the adhesion may be lowered after light irradiation for a long time.

  When a layer having a function of an anti-blocking layer is employed as the primer layer, a film having a layer structure of (base material) / (primer layer) can be stored in a good state as a film roll. However, after the hard coat layer is provided on the primer layer, the anti-blocking function is lost, so that the film having the layer structure of (base material) / (primer layer) / (hard coat layer) After the process, if the film is used as it is as a film roll, the quality of the film is deteriorated.

  Therefore, an object of the present invention is to provide a laminated film that can maintain adhesiveness even after long-term use and can be stored in a good state as a film roll, and a polarizing film that is easy to manufacture and highly durable. To provide a board.

As a result of studying to solve the above-mentioned problems, the present inventor adopted the specific one as the base material layer of the laminated film and specified the layer configuration of the laminated film to solve the above-mentioned plurality of problems. The present invention has been completed by finding that it can be solved at once.
That is, the present invention is as follows.

[1] A laminated film comprising a conductive hard coat layer, a base material layer, and a urethane resin layer in this order, wherein the base material layer is a layer of a thermoplastic resin having an ultraviolet absorbing function.
[2] The laminated film according to [1], wherein the urethane resin layer includes inorganic particles.
[3] The laminated film according to [1] or [2], wherein the thermoplastic resin includes a polymer containing an alicyclic structure.
[4] A resin (A) in which the base material layer includes a first outer layer made of a resin (B) containing a polymer containing an alicyclic structure, a polymer containing an alicyclic structure, and an ultraviolet absorber. ), And a second outer layer made of a resin (B ′) containing a polymer containing an alicyclic structure in this order. The laminated film according to [3].
[5] The laminated film according to any one of [1] to [4], and a polarizer layer provided on the urethane resin layer side surface of the laminated film via an adhesive layer. Polarizer.

  The laminated film of the present invention can maintain adhesion even after long-term use, and can be stored in a good state as a film roll. Moreover, since the polarizing plate of this invention is equipped with the laminated film of the said this invention, manufacture is easy and durability is high.

  Hereinafter, the present invention will be described in detail with reference to embodiments and examples. However, the present invention is not limited to the following embodiments and exemplifications, and can be implemented with any modifications without departing from the scope of the claims of the present invention and the equivalents thereof.

  In the following description, the “long” film refers to a film having a length of 5 times or more, preferably 10 times or more of the width, specifically, A film having such a length that it is wound up in a roll and stored or transported. Although the upper limit of the ratio of the length with respect to the width of a film is not specifically limited, For example, it may be 10,000 times or less.

  In the following description, the in-plane retardation Re of the film is a value represented by Re = (nx−ny) × d unless otherwise specified. Here, nx represents a refractive index in a direction (in-plane direction) perpendicular to the thickness direction of the film and giving the maximum refractive index. ny represents the refractive index in the in-plane direction and orthogonal to the nx direction. nz represents the refractive index in the thickness direction. d represents the thickness of the film. The measurement wavelength is 550 nm unless otherwise specified.

  In the following description, the expression “(meth) acryl” means acrylic, methacrylic, or a combination thereof. For example, “(meth) acrylate” means “acrylate”, “methacrylate” or a mixture thereof, and “(meth) acryloyl group” means “acryloyl group”, “methacryloyl group”, or a mixture thereof.

  In the following description, unless the direction of the component is “parallel” or “vertical”, an error within a range that does not impair the effect of the present invention, for example, within ± 5 °, is included unless otherwise specified. Good.

  In the following description, “polarizing plate” and “wave plate” include not only rigid members but also flexible members such as resin films, unless otherwise specified.

  In the following description, unless otherwise specified, the adhesive is not only a narrowly defined adhesive (an adhesive having a shear storage modulus of 1 MPa to 500 MPa at 23 ° C. after irradiation with energy rays or after heat treatment), A pressure-sensitive adhesive having a shear storage modulus at 23 ° C. of less than 1 MPa is also included.

[1. (Laminated film: Overview)
The laminated film of the present invention includes a conductive hard coat layer, a base material layer, and a urethane resin layer in this order. That is, the laminated film of the present invention has a layer structure of (conductive hard coat layer) / (ultraviolet ray absorbing thermoplastic resin layer) / (urethane resin layer). Therefore, the laminated film may have a structure in which the urethane resin layer is exposed on one surface. By having such a structure, undesirable phenomena such as blocking when the laminated film is used as a film roll can be suppressed. Moreover, when using a laminated film, adhesiveness with other members, such as a polarizing plate, can be improved. In particular, when the urethane resin layer contains particles such as inorganic particles, the function of preventing blocking can be expressed more effectively.

  Further, in the laminated film of the present invention, the base material layer is a thermoplastic resin layer having an ultraviolet absorbing function. Thereby, in the display device, the laminated film of the present invention is provided in such a manner that the surface on the conductive hard coat layer side becomes the display surface side of the device and the surface on the urethane resin layer side is bonded to another member of the device. In this case, the adhesion can be maintained even after long-term use. That is, since the base material layer is a layer of a thermoplastic resin having an ultraviolet absorbing function, when using the laminated film in the display device, the transmission of ultraviolet light from the outside of the device can be reduced in the base material layer, Thereby, the amount of ultraviolet light reaching the urethane resin layer can be reduced. As a result, the adhesiveness between the laminated film and other members and the adhesiveness between the layers in the laminated film can be maintained in a good state even after long-term use.

[2. Conductive hard coat layer)
The conductive hard coat layer is a hard coat layer, that is, a layer that imparts durability to the film surface, and is a conductive layer. The conductive hard coat layer may be a layer containing a conductive material. Examples of such conductive materials include various organic conductive materials and inorganic conductive materials. As a particularly preferable example of the conductive material, conductive metal oxide particles can be given.

  The conductive hard coat layer is usually provided directly on the surface of the base material layer. When the conductive hard coat layer includes metal oxide particles, in the conductive hard coat layer, the metal oxide particles can be aggregated so as to be connected in a chain shape to form a chain-like connected body. A conductive path is formed by this chain-like connected body, and conductivity can be expressed.

[2.1. Metal oxide particles)
In the present application, the metal oxide particles are particles containing a metal oxide. Examples of the metal oxide contained in the metal oxide particles include tin oxide; tin oxide doped with antimony, fluorine or phosphorus; indium oxide; indium oxide doped with antimony, tin or fluorine; antimony oxide; Examples include titanium oxide. In particular, tin oxide doped with antimony and indium oxide doped with antimony are preferable. Moreover, these may be used individually by 1 type and may be used combining two or more types by arbitrary ratios.

The average particle diameter of the metal oxide particles is preferably 2 nm or more, more preferably 4 nm or more, particularly preferably 5 nm or more, preferably 50 nm or less, more preferably 40 nm or less, and particularly preferably 10 nm or less. By setting the average particle diameter of the metal oxide particles to be equal to or greater than the lower limit of the above range, the metal oxide particles are less likely to be aggregated in a granular form. Moreover, since it can make the haze of an electroconductive hard-coat layer small by setting it as an upper limit or less, the transparency of an electroconductive hard-coat layer can be improved. Furthermore, metal oxide particles can be easily connected in a chain.
Here, the average particle diameter of the metal oxide particles indicates a particle diameter that maximizes the scattering intensity when it is assumed that the particle diameter distribution measured by the laser diffraction method shows a normal distribution.

  Moreover, it is preferable that the metal oxide particle is a modified particle in which the surface of the particle is modified with a hydrolyzable organosilicon compound. By performing such modification treatment, the chain connection of the metal oxide particles can be strengthened, and the dispersibility of the metal oxide particles can be improved.

  The conductive metal oxide particles (including modified particles) described above are preferably linked in a chain form in the dispersion or conductive agent containing the metal oxide particles. And since such a connection is maintained also in the conductive hard coat layer, a conductive path is formed in the conductive hard coat layer by the connected metal oxide particles. Therefore, the conductive hard coat layer can exhibit excellent conductivity.

  The average number of metal oxide particles connected is preferably 2 or more, more preferably 3 or more, and particularly preferably 5 or more. The conductivity of the conductive hard coat layer can be increased by setting the average number of connections of the metal oxide particles to the lower limit value or more. The upper limit of the average number of connections of the metal oxide particles is preferably 20 or less, more preferably 10 or less. By making the average number of metal oxide particles connected to the upper limit or less, chain-connected metal oxide particles can be easily produced.

  The average number of connected metal oxide particles can be determined by the following method. A photograph of the chain-like connected body of metal oxide particles is taken with a transmission electron microscope. From this photograph, the number of links in each chain linked body is determined for 100 chain linked bodies of metal oxide particles. And the average value of the connection number of each chain | strand-shaped connection body is calculated, and 1 digit below a decimal point is rounded off, and the average connection number of a metal oxide particle is obtained.

  In the conductive hard coat layer containing metal oxide particles as the conductive material, the amount of metal oxide particles is preferably 3% by weight or more, more preferably 5% by weight or more, and particularly preferably 10% by weight or more. Preferably it is 50 weight% or less, More preferably, it is 30 weight% or less, Most preferably, it is 20 weight% or less. By making the amount of the metal oxide particles equal to or more than the lower limit of the above range, the surface resistance value of the conductive hard coat layer can be reduced and the conductivity can be improved. Moreover, since the haze of an electroconductive hard-coat layer can be made small by setting it as an upper limit or less, the transparency of a laminated | multilayer film can be improved.

[2.2. Binder polymer)
The conductive hard coat layer may contain a binder polymer in addition to a conductive material such as metal oxide particles. By the binder polymer, the conductive material can be held in the conductive hard coat layer, and further, the function as the hard coat layer can be expressed.

  As the binder polymer, a polymer obtained by polymerizing a polymerizable monomer containing 50% by weight or more of a compound having 3 or more (meth) acryloyl groups in one molecule is preferable. By using such a polymer as a binder polymer, the surface resistance value of the conductive hard coat layer can be effectively lowered.

  Examples of the compound having three or more (meth) acryloyl groups in one molecule include pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta ( And (meth) acrylate and dipentaerythritol hexa (meth) acrylate.

  Moreover, the compound which has 3 or more of (meth) acryloyl groups in 1 molecule may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios. For example, a combination of pentaerythritol tri (meth) acrylate and pentaerythritol tetra (meth) acrylate, and dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate These combinations may be used as a polymerizable monomer for obtaining a binder polymer.

  Among the polymerizable monomers described above, a polymerizable monomer containing a total of 80% by weight or more of a compound having four (meth) acryloyl groups in one molecule, a compound having five, and a compound having six. Is preferably used.

  Moreover, as a polymerizable monomer for obtaining a binder polymer, any monomer compound may be used in combination with a compound having three or more (meth) acryloyl groups in one molecule as described above. Good. Examples of such an arbitrary monomer compound include trifunctional (meth) acrylates such as trimethylolpropane tri (meth) acrylate and pentaerythritol tri (meth) acrylate; ethylene glycol diacrylate and ethylene glycol dimethacrylate Polyfunctional unsaturated monomers such as diethylene glycol dimethacrylate, allyl methacrylate, diallyl phthalate, trimethylolpropane triacrylate, glyceryl diallyl ether, polyethylene glycol dimethacrylate, polyethylene glycol diacrylate; bisphenoxyethanol full orange acrylate, 2 -Propenoic acid [5,5 '-(9-fluorene-9-ylidene) bis (1,1'-biphenyl) -2- (polyoxyethylene) Steal], 2-propenoic acid [5,5′-4- (1,1′biphenylyl) methylenebis (1,1′-biphenyl) -2- (polyoxyethylene) ester] and the like (meta ) Compounds having an acryloyl group; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) And acrylic unsaturated monomers of alkyl (meth) acrylates having 1 to 30 carbon atoms such as acrylate, nonyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and the like. Moreover, these may be used individually by 1 type and may be used combining two or more types by arbitrary ratios.

  Further, as an arbitrary monomer compound, when a compound having a carboxyl group and a polymerizable carbon-carbon double bond is used in an amount of 0.01 wt% to 5 wt% in the total amount of the polymerizable monomer, This is preferable because the surface resistance value of the conductive hard coat layer can be effectively reduced. Examples of the compound having a carboxyl group and a polymerizable carbon-carbon double bond include acrylic acid, methacrylic acid, crotonic acid, fumaric acid, itaconic acid, muconic acid, and a half of maleic anhydride and monoalcohol. Esters; compounds in which a part of hydroxyl groups in acrylates having hydroxyl groups such as dipentaerythritol pentaacrylate and pentaerythritol triacrylate are added to the carbon-carbon double bond of acrylic acid; dipentaerythritol pentaacrylate and pentaerythritol tris And a compound obtained by reacting a hydroxyl group in an acrylate having a hydroxyl group such as acrylate with a dicarboxylic acid or carboxylic anhydride. One of these may be used alone, or two or more of these may be used in combination at any ratio.

  In the conductive hard coat layer, the amount of the binder polymer is preferably 50% by weight or more, more preferably 60% by weight or more, particularly preferably 70% by weight or more, preferably 100% by weight or less, more preferably 95%. % By weight or less, particularly preferably 90% by weight or less. By making the amount of the binder polymer within the above range, the adhesion between the conductive hard coat layer and the base material layer can be improved, and in the conductive hard coat layer of a conductive material such as metal oxide particles. The dispersibility of can be improved. Moreover, the thickness of the conductive hard coat layer can be made uniform.

[2.3. (Optional ingredients)
The conductive hard coat layer may contain an optional component in addition to the conductive material and the binder polymer. Moreover, arbitrary components may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

[2.4. Method for forming conductive hard coat layer]
The conductive hard coat layer can be formed by applying a conductive agent on the base material layer. The formation of the conductive hard coat layer may be performed before the formation of the urethane resin layer or may be performed after the formation of the urethane resin layer, but from the viewpoint of obtaining a conductive hard coat layer with good physical properties, It is preferable to carry out after the steps of forming the urethane resin layer and stretching the base material layer.

  The conductive agent may include a conductive material such as metal oxide particles, a binder polymer, and / or a polymerizable monomer that can form a binder polymer by polymerization. In addition, since the conductive agent is usually fluid at the time of application, it is preferable to perform a step of curing the applied conductive agent film after applying the conductive agent on the base material layer. When the polymerizable monomer is polymerized in the curing, the polymerization can be performed by irradiation with active energy rays such as ultraviolet rays.

  The conductive agent can be used as a conductive agent composition mixed with a solvent, if necessary. The solvent is preferably one that can dissolve the polymerizable monomer and can easily volatilize. Examples of such solvents include water; alcohols such as methanol, ethanol, propanol, butanol, isopropanol, diacetone alcohol, furfuryl alcohol, tetrahydrofurfuryl alcohol, ethylene glycol, hexylene glycol, and isopropyl glycol; methyl acetate Esters such as esters and acetic acid ethyl esters; ethers such as diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether and tetrahydrofuran; acetone , Methyl ethyl ketone, methyl isobutyl ketone, acetyl Acetone, acetoacetic acid esters, ketones such as cyclohexanone; methyl cellosolve, ethyl cellosolve, cellosolve such as butyl cellosolve; toluene, aromatic compounds such as xylene, isophorone, and the like. Moreover, a solvent may be used individually by 1 type and may be used combining two or more types by arbitrary ratios.

  The amount of the solvent is preferably set so that the solid content concentration of the conductive agent composition falls within a desired range. Here, the solid content concentration of the conductive agent composition is preferably 10% by weight or more, more preferably 20% by weight or more, preferably 70% by weight or less, more preferably 55% by weight or less. By keeping the solid content concentration in the conductive agent in the above range, the thickness of the conductive hard coat layer can be easily kept in an appropriate range, and a conductive hard coat layer having sufficient conductivity can be easily manufactured. Furthermore, normally, since the haze of the conductive hard coat layer can be lowered, the transparency of the laminated film can be improved. Moreover, the crack of a conductive hard-coat layer and the curvature of a base material layer can be suppressed normally. Furthermore, since the viscosity of the conductive agent can be lowered, the conductive agent can be applied satisfactorily. Therefore, the flatness of the surface of the conductive hard coat layer can be improved, and the occurrence of streak unevenness can be suppressed.

  As a conductive agent for forming the conductive hard coat layer, a commercially available conductive agent or a mixture of a commercially available conductive agent and a component such as a solvent can be used. Examples of such a conductive agent include “Pertron XJC-0639” (manufactured by Pernox Corporation).

[2.5. Structure and dimensions of conductive hard coat layer]
The conductive hard coat layer may have a multilayer structure including two or more layers, but preferably has a single-layer structure composed of only one layer. When the conductive hard coat layer has a single layer structure, the conductive hard coat layer can be easily manufactured, and the thickness of the laminated film can be reduced.

The thickness of the conductive hard coat layer is preferably 0.5 μm or more, more preferably 1.0 μm or more, still more preferably 1.3 μm or more, preferably 10.0 μm or less, more preferably 8.0 μm or less, and further Preferably it is 5.0 micrometers or less. By keeping the thickness of the conductive hard coat layer within the above range, curling of the laminated film can be suppressed, or the surface resistance value of the conductive hard coat layer can be lowered. Furthermore, usually, the scratch resistance of the conductive hard coat layer can be improved.
The thickness of the conductive hard coat layer can be measured with an interference film thickness meter ("F20 film thickness measurement system" manufactured by Filmetrics).

[2.6. Physical properties of conductive hard coat layer)
The surface resistance value of the conductive hard coat layer is preferably 1.0 × 10 ⁶ Ω / □ or more, more preferably 1.0 × 10 ⁷ Ω / □ or more, and even more preferably 1.0 × 10 ⁸ Ω / □. □ or more, preferably 1.0 × 10 ¹⁰ Ω / □ or less, more preferably 5.0 × 10 ⁹ Ω / □ or less, and even more preferably 1.0 × 10 ⁹ Ω / □ or less. When the conductive hard coat layer has such a surface resistance value, the conductivity of the laminated film can be increased. Therefore, for example, when a laminated film is incorporated in an in-cell type display device, it is possible to suppress the occurrence of drive unevenness due to charging during operation of the touch sensor.
The surface resistance value of the conductive hard coat layer can be determined by measuring the surface resistance value on the surface of the conductive hard coat protective film on the conductive hard coat layer side. Surface resistance is measured using Hiresta XP (Mitsubishi Eletech), probe URS, 500V, 10 seconds, or JIS K6911 digital super insulation / microammeter (Hioki Denki) "DSM-8104").

The refractive index of the conductive hard coat layer is preferably 1.500 or more, more preferably 1.510 or more, further preferably 1.520 or more, particularly preferably 1.530 or more, preferably 1.560 or less, More preferably, it is 1.555 or less, More preferably, it is 1.550 or less. By keeping the refractive index of the conductive hard coat layer in the above range, the refractive index of the conductive hard coat layer can be kept in the same range as the refractive index of the base material layer. This makes it difficult to visually recognize coating unevenness and spot unevenness of the conductive hard coat layer, so that it is easy to improve the appearance of the laminated film.
The refractive index of the conductive hard coat layer is subjected to Cauchy fitting based on values measured at three wavelengths of 407 nm, 532 nm, and 633 nm with a refractive index film thickness measuring device (“Prism Coupler” manufactured by Metricon). It is a numerical value obtained at a wavelength of 550 nm.

  The JIS pencil hardness of the conductive hard coat layer is preferably B or higher, more preferably HB or higher, and particularly preferably H or higher. By increasing the JIS pencil hardness of the conductive hard coat layer, the conductive hard coat layer can function as a hard coat layer, so that the scratch resistance of the laminated film can be improved. Here, in accordance with JIS K5600-5-4, the JIS pencil hardness is determined by tilting a pencil of various hardness by 45 °, applying a load of 500 g from above, scratching the surface of the layer, and starting scratching. Hardness.

  As for the scratch resistance of the conductive hard coat layer, use steel wool of # 0000, attach the steel wool to a cylindrical jig with a diameter of 25 mm, and load the conductive hard coat layer with the steel wool at the bottom of the jig. It can be evaluated by rubbing 10 reciprocations at 400 gf and a stroke of 50 mm, visually observing the surface after rubbing, and counting the number of scratches. In this case, the number of scratches is preferably 5 or less, more preferably 0. By improving the scratch resistance of the conductive hard coat layer, scratches due to inadvertent external factors in processing steps such as the production of a polarizing plate can be suppressed.

[3. (Base material layer)
The base material layer in the laminated film of the present invention is a thermoplastic resin layer having an ultraviolet absorbing function. The base material layer may be a layer including one or more layers of a thermoplastic resin including an ultraviolet absorber.

  In a preferred embodiment, the base material layer comprises a first outer layer made of a resin (B) containing a polymer containing an alicyclic structure, a resin containing a polymer containing an alicyclic structure and an ultraviolet absorber (A ) And a second outer layer made of a resin (B ′) containing a polymer containing an alicyclic structure in this order. Usually, the first outer layer and the intermediate layer are in contact with each other, and the intermediate layer and the second outer layer are in contact with each other.

  Since the base material layer has such a (first outer layer) / (intermediate layer) / (second outer layer) layer structure, excellent heat resistance and moisture resistance due to the alicyclic structure-containing polymer resin. The base material layer can exhibit the effect of weakening the ultraviolet light that passes through the base material layer, and the bleeding out of the ultraviolet absorber can be suppressed.

In this base material layer, the ratio “T _(A) / (T _{(B) )} of the thickness T _(A) of the intermediate layer to the total thickness T _(B) + T _{(B ′)} of the first outer layer and the second outer layer. + T _{(B ′)} ) ”is preferably within a predetermined range. Specifically, the ratio “T _(A) / (T _(B) + T _{(B ′)} )” is usually 0.3 or more, preferably 0.4 or more, and usually less than 1.5, preferably 1 .30 or less, more preferably 1.10 or less. When the thickness ratio “T _(A) / (T _(B) + T _{(B ′)} )” is above the lower limit of the above range, the base material layer is effective for ultraviolet rays that pass through the base material layer. The number of foreign matters generated by the kneading of the polymer and the ultraviolet absorber can be reduced by visual observation in the base material layer by being less than the upper limit of the above range. it can.

[3.1. (Middle layer)
The polymer containing an alicyclic structure constituting the intermediate layer is a polymer in which the structural unit of the polymer contains an alicyclic structure. A polymer containing an alicyclic structure is usually excellent in heat and moisture resistance. Therefore, by using a polymer containing an alicyclic structure, the moisture and heat resistance of the base material layer can be improved.

  The polymer containing an alicyclic structure may have an alicyclic structure in the main chain, and may have an alicyclic structure in the side chain. Among these, from the viewpoint of mechanical strength and heat resistance, a polymer containing an alicyclic structure in the main chain is preferable.

  Examples of the alicyclic structure include a saturated alicyclic hydrocarbon (cycloalkane) structure and an unsaturated alicyclic hydrocarbon (cycloalkene, cycloalkyne) structure. Among these, from the viewpoint of mechanical strength and heat resistance, a cycloalkane structure and a cycloalkene structure are preferable, and a cycloalkane structure is particularly preferable.

  The number of carbon atoms constituting the alicyclic structure is preferably 4 or more, more preferably 5 or more, preferably 30 or less, more preferably 20 or less, particularly preferably per alicyclic structure. Is a range of 15 or less. By setting the number of carbon atoms constituting the alicyclic structure within this range, the mechanical strength, heat resistance and moldability of the resin containing the polymer containing the alicyclic structure are highly balanced.

  In the polymer containing an alicyclic structure, the proportion of structural units having an alicyclic structure can be appropriately selected depending on the purpose of use. The proportion of structural units having an alicyclic structure in a polymer containing an alicyclic structure is preferably 55% by weight or more, more preferably 70% by weight or more, and particularly preferably 90% by weight or more. When the ratio of the structural unit having an alicyclic structure in the polymer containing the alicyclic structure is within this range, the transparency and heat resistance of the resin containing the polymer containing the alicyclic structure are improved.

  Examples of the polymer containing an alicyclic structure include a norbornene polymer, a monocyclic olefin polymer, a cyclic conjugated diene polymer, a vinyl alicyclic hydrocarbon polymer, and hydrides thereof. Can be mentioned. Among these, norbornene-based polymers are more preferable because of their good transparency and moldability.

  Examples of the norbornene-based polymer include a ring-opening polymer of a monomer having a norbornene structure and a hydrogenated product thereof; an addition polymer of a monomer having a norbornene structure and a hydrogenated product thereof. Examples of a ring-opening polymer of a monomer having a norbornene structure include a ring-opening homopolymer of one kind of monomer having a norbornene structure and a ring-opening of two or more kinds of monomers having a norbornene structure. Examples thereof include a copolymer and a ring-opening copolymer of a monomer having a norbornene structure and an arbitrary monomer copolymerizable therewith. Furthermore, examples of the addition polymer of a monomer having a norbornene structure include an addition homopolymer of one kind of monomer having a norbornene structure and an addition copolymer of two or more kinds of monomers having a norbornene structure. And addition copolymers of a monomer having a norbornene structure and an arbitrary monomer copolymerizable therewith. Among these, a hydrogenated product of a ring-opening polymer of a monomer having a norbornene structure is particularly preferable from the viewpoints of moldability, heat resistance, low hygroscopicity, dimensional stability and lightness.

Examples of the monomer having a norbornene structure include bicyclo [2.2.1] hept-2-ene (common name: norbornene), tricyclo [4.3.0.1 ^2,5 ] deca-3,7. -Diene (common name: dicyclopentadiene), 7,8-benzotricyclo [4.3.0.1 ^2,5 ] dec-3-ene (common name: methanotetrahydrofluorene), tetracyclo [4.4. 0.1 ^2,5 . ^{17, 10} ] dodec-3-ene (common name: tetracyclododecene), and derivatives of these compounds (for example, those having a substituent in the ring). Here, examples of the substituent include an alkyl group, an alkylene group, and a polar group. These substituents may be the same or different, and a plurality thereof may be bonded to the ring. One type of monomer having a norbornene structure may be used alone, or two or more types may be used in combination at any ratio.

  Examples of the polar group include a hetero atom or an atomic group having a hetero atom. Examples of the hetero atom include an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, and a halogen atom. Specific examples of the polar group include a carboxyl group, a carbonyloxycarbonyl group, an epoxy group, a hydroxyl group, an oxy group, an ester group, a silanol group, a silyl group, an amino group, a nitrile group, and a sulfonic acid group.

  Examples of the monomer capable of ring-opening copolymerization with a monomer having a norbornene structure include monocyclic olefins such as cyclohexene, cycloheptene, and cyclooctene and derivatives thereof; cyclic conjugated dienes such as cyclohexadiene and cycloheptadiene; Derivatives thereof; and the like. As the monomer having a norbornene structure and a monomer capable of ring-opening copolymerization, one kind may be used alone, or two or more kinds may be used in combination at any ratio.

  A ring-opening polymer of a monomer having a norbornene structure can be produced, for example, by polymerizing or copolymerizing a monomer in the presence of a ring-opening polymerization catalyst.

  Examples of monomers that can be copolymerized with a monomer having a norbornene structure include α-olefins having 2 to 20 carbon atoms such as ethylene, propylene, and 1-butene, and derivatives thereof; cyclobutene, cyclopentene, and cyclohexene. And non-conjugated dienes such as 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene; and the like. Among these, α-olefin is preferable and ethylene is more preferable. Moreover, the monomer which can carry out addition copolymerization with the monomer which has a norbornene structure may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  An addition polymer of a monomer having a norbornene structure can be produced, for example, by polymerizing or copolymerizing a monomer in the presence of an addition polymerization catalyst.

  The hydrogenated product of the ring-opening polymer and the addition polymer described above is, for example, a carbon-carbon in a solution of the ring-opening polymer and the addition polymer in the presence of a hydrogenation catalyst containing a transition metal such as nickel or palladium. Unsaturated bonds can be produced by hydrogenation, preferably 90% or more.

Among norbornene-based polymers, as structural units, X: bicyclo [3.3.0] octane-2,4-diyl-ethylene structure and Y: tricyclo [4.3.0.1 ^2,5 ] decane- Having a 9,9-diyl-ethylene structure, the amount of these structural units being 90% by weight or more based on the total structural units of the norbornene polymer, and the ratio of X and Y It is preferable that the ratio is 100: 0 to 40:60 by weight ratio of X: Y. By using such a polymer, the layer containing the norbornene-based polymer can be made long-term without dimensional change and excellent in optical property stability.

  The weight average molecular weight (Mw) of the polymer containing an alicyclic structure is preferably 10,000 or more, more preferably 15,000 or more, particularly preferably 20,000 or more, preferably 100,000 or less, More preferably, it is 80,000 or less, Most preferably, it is 50,000 or less. When the weight average molecular weight is in such a range, the mechanical strength and moldability of the layer containing the polymer containing the alicyclic structure are highly balanced.

  The molecular weight distribution (Mw / Mn) of the polymer containing an alicyclic structure is preferably 1.2 or more, more preferably 1.5 or more, particularly preferably 1.8 or more, preferably 3.5 or less. More preferably, it is 3.0 or less, and particularly preferably 2.7 or less. Here, Mn represents a number average molecular weight. By making molecular weight distribution more than the lower limit of the said range, productivity of a polymer can be improved and manufacturing cost can be suppressed. In addition, since the amount of the low-molecular component is reduced by setting it to the upper limit or less, the relaxation during high-temperature exposure can be suppressed and the stability of the layer containing the polymer containing the alicyclic structure can be improved. .

  The weight average molecular weight (Mw) and number average molecular weight (Mn) were determined by gel permeation chromatography using cyclohexane as a solvent (however, toluene may be used when the sample does not dissolve in cyclohexane). , Polyisoprene or polystyrene as a weight average molecular weight.

  The glass transition temperature of the polymer containing an alicyclic structure is preferably 100 ° C or higher, more preferably 110 ° C or higher, particularly preferably 120 ° C or higher, preferably 160 ° C or lower, more preferably 150 ° C or lower, Especially preferably, it is 140 degrees C or less. By setting the glass transition temperature of the polymer containing the alicyclic structure to be equal to or higher than the lower limit of the above range, the durability of the base material layer in a high temperature environment can be increased, and to be equal to or lower than the upper limit of the above range. Thus, the base layer can be easily stretched.

  The amount of the polymer containing an alicyclic structure in the resin (A) contained in the intermediate layer is preferably 84.0% by weight or more, more preferably 90.0% by weight or more, preferably 95.0% by weight. % Or less, more preferably 93.0% by weight or less. When the ratio of the polymer containing an alicyclic structure is within the above range, the heat and moisture resistance of the base material layer can be effectively improved.

  As the ultraviolet absorber, a compound capable of absorbing ultraviolet rays can be used. By using the ultraviolet absorber, it is possible to impart an ability to prevent the transmission of ultraviolet rays to the base material layer. Examples of the UV absorber include organic UV absorbers such as triazine UV absorbers, benzophenone UV absorbers, benzotriazole UV absorbers, and acrylonitrile UV absorbers.

  As the triazine-based ultraviolet absorber, for example, a compound having a 1,3,5-triazine ring is preferable. Specific examples of the triazine ultraviolet absorber include 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol, 2,4-bis. (2-hydroxy-4-butoxyphenyl) -6- (2,4-dibutoxyphenyl) -1,3,5-triazine and the like. Examples of commercially available products of such triazine-based ultraviolet absorbers include “Tinubin 1577” manufactured by Ciba Specialty Chemicals.

  Examples of the benzotriazole ultraviolet absorber include 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2 -(3,5-di-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (2H-benzotriazol-2-yl) -p-cresol, 2- (2H-benzotriazole-2) -Yl) -4,6-bis (1-methyl-1-phenylethyl) phenol, 2-benzotriazol-2-yl-4,6-di-tert-butylphenol, 2- [5-chloro (2H)- Benzotriazol-2-yl] -4-methyl-6- (tert-butyl) phenol, 2- (2H-benzotriazol-2-yl) -4,6-di-t rt-butylphenol, 2- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol, 2- (2H-benzotriazol-2-yl) -4-methyl -6- (3,4,5,6-tetrahydrophthalimidylmethyl) phenol, methyl 3- (3- (2H-benzotriazol-2-yl) -5-tert-butyl-4-hydroxyphenyl) propionate / Examples of the reaction product of polyethylene glycol 300 include 2- (2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl) -4-methylphenol. Examples of such commercially available triazole ultraviolet absorbers include “ADEKA STAB LA-31” manufactured by ADEKA.

  One type of ultraviolet absorber may be used alone, or two or more types may be used in combination at any ratio.

  The amount of the ultraviolet absorber in the resin (A) contained in the intermediate layer is preferably 5% by weight or more, more preferably 7% by weight or more, preferably 16% by weight or less, more preferably 10% by weight or less. . When the amount of the ultraviolet absorber is not less than the lower limit value of the above range, the ability of the base material layer to prevent the transmission of ultraviolet light can be particularly enhanced, and by being not more than the upper limit value of the above range, Transparency to visible light can be increased.

  The resin (A) contained in the intermediate layer may further contain optional components in combination with the polymer containing the alicyclic structure and the ultraviolet absorber. Examples of optional components include colorants such as pigments and dyes; plasticizers; fluorescent brighteners; dispersants; thermal stabilizers; light stabilizers; antistatic agents; antioxidants; Is mentioned. One of these may be used alone, or two or more of these may be used in combination at any ratio.

  The manufacturing method of resin (A) is arbitrary and can manufacture by mixing the polymer and ultraviolet absorber containing an alicyclic structure, and arbitrary components as needed. Usually, the resin (A) is produced by kneading a polymer containing an alicyclic structure and an ultraviolet absorber at a temperature at which the polymer containing the alicyclic structure can melt. For kneading, for example, a twin screw extruder can be used.

  The thickness of the intermediate layer is preferably 4.6 μm or more, more preferably 6.0 μm or more, particularly preferably 7.0 μm or more, preferably 22.0 μm or less, more preferably 20.0 μm or less, particularly preferably 18 0.0 μm or less. When the thickness of the intermediate layer is equal to or higher than the lower limit value of the range, the ability of the base material layer to prevent the transmission of ultraviolet rays can be particularly enhanced, and when the thickness of the intermediate layer is equal to or lower than the upper limit value of the range, the thickness of the base material layer It is possible to reduce the thickness of the base material layer and save space.

The thicknesses of the layers such as the intermediate layer, the first outer layer and the second outer layer included in the base material layer can be measured by the following method.
A base material layer is embedded with an epoxy resin, and a sample piece is prepared. This sample piece is sliced to a thickness of 0.05 μm using a microtome. Then, the thickness of each layer contained in the base material layer can be measured by observing the cross section that appears by slicing using a microscope.

[3.2. (First outer layer)
Examples of the polymer containing the alicyclic structure contained in the resin (B) constituting the first outer layer are the same as the polymer containing the alicyclic structure contained in the resin (A). Can be mentioned. Thereby, the advantage similar to having described by description of the polymer containing the alicyclic structure of resin (A) can be acquired. Especially, as a polymer containing the alicyclic structure contained in resin (B), it is preferable to use the same polymer as the polymer containing the alicyclic structure contained in resin (A). Thereby, it is easy to increase the adhesive strength between the intermediate layer and the first outer layer, or to suppress the reflection of light at the interface between the intermediate layer and the first outer layer.

  The amount of the polymer containing an alicyclic structure in the resin (B) is preferably 90.0 wt% to 100 wt%, more preferably 95.0 wt% to 100 wt%. By setting the amount of the polymer containing the alicyclic structure within the above range, the heat and moisture resistance and mechanical strength of the base material layer can be effectively increased.

  The resin (B) can contain an ultraviolet absorber, but the amount of the ultraviolet absorber in the resin (B) is preferably small, and the resin (B) more preferably does not contain the ultraviolet absorber. Since the resin (B) does not contain the ultraviolet absorber, the first outer layer does not contain the ultraviolet absorber, so that bleeding out of the ultraviolet absorber can be effectively suppressed.

  Resin (B) can further contain arbitrary components in combination with the polymer containing an alicyclic structure. As an arbitrary component, the same component as mentioned as an arbitrary component which resin (A) can contain is mentioned, for example. One of these may be used alone, or two or more of these may be used in combination at any ratio.

  The thickness of the first outer layer is preferably 4.0 μm or more, more preferably 5.0 μm or more, particularly preferably 6.0 μm or more, preferably 15.0 μm or less, more preferably 14.0 μm or less, and particularly preferably Is 13.0 μm or less. When the thickness of the first outer layer is not less than the lower limit of the above range, it is possible to effectively suppress bleeding out of the ultraviolet absorber contained in the intermediate layer to the outside of the film, and to detect foreign matter detected visually. The number can be effectively reduced, and by being below the upper limit of the above range, the thickness of the base material layer can be reduced, and the weight and space saving of the base material layer can be realized.

[3.3. (Second outer layer)
A 2nd outer side layer is a layer which consists of resin (B ') containing the polymer containing an alicyclic structure. Examples of the resin (B ′) are the same as the examples of the resin described as the resin (B). Thereby, the advantage similar to having described in description of resin (B) of a 1st outer side layer can be acquired.

  The resin (B ′) may be a resin different from the resin (B), or may be the same resin as the resin (B). Among these, it is preferable to use the same resin as the resin (B) and the resin (B ′). By using the same resin as the resin (B) and the resin (B ′), the manufacturing cost of the base material layer can be suppressed, and curling of the base material layer can be suppressed.

  The thickness of the second outer layer can be any thickness selected from the range described as the thickness range of the first outer layer. Thereby, the same advantage as described in the explanation of the thickness of the first outer layer can be obtained. Especially, in order to suppress curling of the base material layer, it is preferable that the thickness of the second outer layer is the same as that of the first outer layer.

[3.4. Base material layer thickness]
The thickness of the base material layer is preferably 20 μm or more, more preferably 21.0 μm or more, particularly preferably 22.0 μm or more, preferably 40 μm or less, more preferably 38.0 μm or less, particularly preferably 36.0 μm or less. It is. When the thickness of the base material layer is equal to or higher than the lower limit value of the range, the mechanical strength of the base material layer can be increased, and when the thickness is equal to or lower than the upper limit value of the range, the weight of the base material layer and space saving are reduced. Can be realized.

[3.5. Physical properties of substrate layer)
The specific light transmittance at a wavelength of 380 nm of the base material layer is preferably 10% or less, more preferably 8% or less, and particularly preferably 5% or less. Furthermore, it is preferable that the base material layer has a small light transmittance at a wavelength of 280 nm to 370 nm. The specific light transmittance at a wavelength of 280 nm to 370 nm of the base material layer is preferably 1.5% or less, more preferably 1% or less.

  The base material layer preferably has a high total light transmittance from the viewpoint of stably exhibiting the function as an optical member. The specific total light transmittance of the base material layer is preferably 85% to 100%, more preferably 87% to 100%, and particularly preferably 90% to 100%. The total light transmittance can be measured using a spectrophotometer according to JIS K0115.

  The substrate layer may be an optically isotropic film having substantially no in-plane retardation, and is an optically anisotropic film having an in-plane retardation having a size according to the application. Also good. For example, when the substrate layer is an optically isotropic film, the specific in-plane retardation Re of the substrate layer is preferably 0 nm to 20 nm, more preferably 0 nm to 10 nm, and particularly preferably 0 nm to 5 nm. sell. For example, when the base material layer is an optically anisotropic film that can function as a quarter-wave plate, the specific in-plane retardation Re of the base material layer is preferably 80 nm or more, more preferably 85 nm. In particular, the thickness may be 90 nm or more and preferably 180 nm or less, more preferably 160 nm or less, and particularly preferably 150 nm or less.

[3.6. Manufacturing method of base material layer]
There is no restriction | limiting in the manufacturing method of a base material layer. When the base material layer has a layer configuration of (first outer layer) / (intermediate layer) / (second outer layer), the resin (B), the resin (A), and the resin (B ′) can be arbitrarily molded. The base material layer can be produced by molding by the method. Examples of the forming method include a co-extrusion method and a co-casting method. Among these molding methods, the coextrusion method is preferable because it is excellent in production efficiency and hardly causes volatile components to remain in the base material layer.

  Moreover, the manufacturing method of a base material layer may include the extending process. By subjecting the base material layer obtained by molding the resin as described above to stretching, desired optical properties can be expressed in the base material layer.

[4. Urethane resin layer)
The urethane resin layer is a resin layer containing polyurethane or a reaction product thereof. Such a urethane resin layer is excellent in adhesiveness with other members. Furthermore, when the urethane resin layer includes particles, it is possible to stably suppress the dropping of the particles by polyurethane.

[4.1. Polyurethane)
As the polyurethane, for example, polyurethane obtained by reacting (i) a component containing an average of 2 or more active hydrogens in one molecule and (ii) a polyisocyanate component can be used. In addition, as the polyurethane, for example, the component (i) and the component (ii) are urethanated in an organic solvent which is inert to the reaction and has a high affinity with water under the condition of excess isocyanate group. A polyurethane produced by making a group-containing prepolymer, then neutralizing the prepolymer, chain extending with a chain extender, and adding water to form a dispersion may be used. Examples of the chain extension method for the isocyanate group-containing prepolymer include a method in which the isocyanate group-containing prepolymer and the chain extender are reacted in the presence of a catalyst, if necessary. In this case, water, water-soluble polyamine, glycols, etc. can be used as the chain extender.

  As said (i) component, what has a hydroxyl active hydrogen is preferable, for example, the compound which has an average of 2 or more hydroxyl groups in 1 molecule is preferable. Specific examples of the component (i) include the following (1) polyol compound, (2) polyether polyol, (3) polyester polyol, (4) polyether ester polyol, and (5) polycarbonate polyol.

(1) Polyol compound:
Examples of the polyol compound include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,4-butylene glycol, 1,5. -Pentanediol, neopentyl glycol, 1,6-hexane glycol, 2,5-hexanediol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, tricyclodecane dimethanol, 1,4 -Cyclohexanedimethanol, 2,2-dimethylpropanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octamethylenediol, glycerin, trimethylolpropane and the like.

(2) Polyether polyol:
Examples of the polyether polyol include (1) an alkylene oxide adduct of a polyol compound; a ring-opening copolymer of an alkylene oxide and a cyclic ether (for example, tetrahydrofuran); polyethylene glycol, polypropylene glycol, ethylene glycol-propylene glycol copolymer And glycols such as glycol, polytetramethylene glycol, polyhexamethylene glycol and polyoctamethylene glycol; and the like. Specific examples of the polyether polyol include poly (oxypropylene ether) polyol and poly (oxyethylene-propylene ether) polyol.

(3) Polyester polyol:
Examples of the polyester polyol include those obtained by polycondensation of a polyvalent carboxylic acid or an anhydride thereof and the above (1) polyol compound under hydroxyl-excess conditions. Examples of the polyvalent carboxylic acid include dicarboxylic acids such as adipic acid, succinic acid, sebacic acid, glutaric acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, and terephthalic acid; and tricarboxylic acids such as trimellitic acid. Is mentioned. Specific examples of polyester polyols include ethylene glycol-adipic acid condensate, butanediol-adipine condensate, hexamethylene glycol-adipic acid condensate, ethylene glycol-propylene glycol-adipic acid condensate, or glycol as an initiator. And polylactone diol obtained by ring-opening polymerization of lactone.

(4) Polyether ester polyol:
As the polyether ester polyol, for example, an ether group-containing polyol (for example, the (2) polyether polyol and diethylene glycol, etc.) or a mixture of this with another glycol can be used as a polyvalent carboxylic acid as exemplified in the above (3). Examples include those obtained by mixing with an acid or an anhydride thereof and reacting with an alkylene oxide. Specific examples of the polyether ester polyol include polytetramethylene glycol-adipic acid condensate.

(5) Polycarbonate polyol:
Examples of the polycarbonate polyol include, for example, the general formula HO—R— (O—C (O) —O—R) _X —OH (wherein R represents a saturated fatty acid polyol residue having 1 to 12 carbon atoms). In addition, X represents the number of molecular structural units, and is usually an integer of 5 to 50). These are a transesterification method in which a saturated aliphatic polyol and a substituted carbonate (for example, diethyl carbonate, diphenyl carbonate, etc.) are reacted under the condition that the hydroxyl group becomes excessive; the saturated aliphatic polyol and phosgene are reacted, or If necessary, it can be obtained by a method of further reacting a saturated aliphatic polyol thereafter.

  These (i) components may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

Examples of the component (ii) to be reacted with the component (i) (that is, the polyisocyanate component) include compounds containing an average of 2 or more isocyanate groups in one molecule. This compound may be an aliphatic compound, an alicyclic compound, or an aromatic compound.
The aliphatic polyisocyanate compound is preferably an aliphatic diisocyanate having 1 to 12 carbon atoms, and examples thereof include hexamethylene diisocyanate, 2,2,4-trimethylhexane diisocyanate, and hexane diisocyanate (HDI).
The alicyclic polyisocyanate compound is preferably an alicyclic diisocyanate having 4 to 18 carbon atoms, such as 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (HMDI), and the like. Is mentioned.
Examples of the aromatic polyisocyanate include tolylene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, and the like.

  These (ii) components may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  As the component (i) and the component (ii), appropriate ones can be arbitrarily selected according to the use of the laminated film. Among them, as the component (i), it is preferable to use a component having a bond that is difficult to hydrolyze. Specifically, (2) polyether polyol and (5) polycarbonate polyol are preferable, and (2) polyether polyol is particularly preferable. Particularly preferred.

  These polyurethanes may contain acid structures or other polar groups in their molecular structure. By including such a polar group, physical properties such as dispersibility in water are improved, and the production of the urethane resin layer can be facilitated. Moreover, the reactivity with a crosslinking agent can be improved.

  As polyurethane, you may use what is marketed as a water-based urethane resin. The water-based urethane resin is a composition containing polyurethane and water, and is usually a composition in which polyurethane and optional components contained as necessary are dispersed in water. Examples of water-based urethane resins include the “ADEKA BONTITER” series manufactured by ADEKA, the “Olestar” series manufactured by Mitsui Chemicals, the “Bondic” series manufactured by DIC, and the “Hydran (WLS201, WLS202, etc.)” series. Bayer's "Imprunil" series, Kao's "Poise" series, Sanyo Kasei's "Samprene" series, Daiichi Kogyo Seiyaku's "Superflex" series, Enomoto Kasei's " NEOREZ (Neoreds) series, “Sancure” series manufactured by Lubrizol, and the like can be used. In addition, one type of polyurethane may be used alone, or two or more types may be used in combination at any ratio.

[4.2. Urethane resin layer forming method: coating solution]
The urethane resin layer can be formed by applying and curing a coating liquid containing polyurethane such as those exemplified above on the base material layer. The coating liquid can contain an arbitrary component in addition to polyurethane. Examples of the optional component include those exemplified below. The optional component may be one that disappears or decreases in content in the step of forming the urethane resin layer using the coating liquid, such as a solvent. What existed may be included in the urethane resin layer as it is, for example, it may react with other components in the process of forming the urethane resin layer using a coating liquid, such as a crosslinking agent. Good.

[4.2.1. solvent〕
The coating liquid can contain a solvent. As a solvent that the coating liquid may contain, for example, water or a water-soluble solvent is used. Examples of the water-soluble solvent include methanol, ethanol, isopropyl alcohol, acetone, tetrahydrofuran, N-methylpyrrolidone, dimethyl sulfoxide, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, and the like. Among these, water is preferably used as the solvent. When water is used as the solvent, the coating liquid is usually an aqueous dispersion of a resin containing a polymer. A solvent may be used individually by 1 type and may be used combining two or more types by arbitrary ratios.

  The amount of the solvent is usually set so that the concentration of the solid content of the coating liquid can be within a desired range. Here, the solid content of the coating liquid refers to a component remaining after drying of the coating liquid. The desired range is preferably 1% by weight or more, more preferably 1.5% by weight or more, particularly preferably 2% by weight or more, preferably 10% by weight or less, more preferably 8% by weight or less, particularly Preferably it is 6 weight% or less. Thereby, since the viscosity of a coating liquid can be adjusted to a suitable range, the handleability and coating property of a coating liquid can be made favorable.

[4.2.2. Crosslinking agent]
The coating solution may further contain a crosslinking agent. The crosslinking agent can crosslink the polymer by reacting with a reactive group of the polymer to form a bond. Therefore, for example, by cross-linking the polymer after applying the coating liquid to the base material layer, the adhesiveness between the urethane resin layer and the base material layer, and the mechanical strength and heat and humidity resistance of the urethane resin layer are improved. Can be improved.

  Specific examples of the crosslinking agent include epoxy compounds, carbodiimide compounds, oxazoline compounds, and isocyanate compounds. Moreover, a crosslinking agent may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios. The coating liquid may also contain a curing accelerator and a curing aid in combination with a crosslinking agent.

[4.2.3. Nonvolatile base)
The coating solution may further contain a non-volatile base. Examples of the non-volatile base include a base that is substantially non-volatile under the treatment conditions when the coating liquid is applied to the base material layer and then dried (for example, when left at 80 ° C. for 1 hour). Here, being substantially non-volatile means that a decrease in non-volatile base is usually 80% or less. Such a non-volatile base can function as a neutralizing agent for neutralizing an acid structure contained in a polymer such as polyurethane.

  As the non-volatile base, an inorganic base or an organic base may be used. Among them, an organic base having a boiling point of 100 ° C. or higher is preferable, an amine compound having a boiling point of 100 ° C. or higher is more preferable, and an amine compound having a boiling point of 200 ° C. or higher is particularly preferable. The organic base may be a low molecular compound or a polymer.

  If the example of a non-volatile base is given, as an inorganic base, sodium hydroxide and potassium hydroxide will be mentioned, for example. Examples of the organic base include 2-amino-2-methyl-1-propanol (AMP), triethanolamine, triisopropanolamine (TIPA), monoethanolamine, diethanolamine, and tri [(2-hydroxy) -1 -Propyl] amine, 2-amino-2-methyl-1,3-propanediol (AMPD), 2-amino-2-hydroxymethyl-1,3-propane potassium hydroxide, γ-aminopropyltriethoxysilane, γ -Aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethyldimethoxysilane, N-methyl-3-aminopropyltrimethoxycarbon Acid dihydrazide, oxalic acid dihydrazide, malonic acid di Dolazide, succinic dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, dodecanedioic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, cyclohexylamine, hexamethylenediamine, N, N-dimethylformamide, ethylenediamine, diethylenetriamine, tetraethylenepentamine, Pentaethylenepentamine, isopropanolamine, N, N-diethylmethanolamine, N, N-dimethylethanolamine, aminoethylethanolamine, N-methyl-NN-diethanolamine, 1,2-propanediamine, 1,6- Examples include hexamethylenediamine and amino resins (for example, 1,3-dimethyl-4-chloro-melamine resin, urea resin, guanamine resin, etc.). Moreover, these may be used individually by 1 type and may be used combining two or more types by arbitrary ratios.

  The amount of the non-volatile base is preferably 0.5 parts by weight or more, more preferably 1 part by weight or more, particularly preferably 2 parts by weight or more, preferably 100 parts by weight of the polymer contained in the coating liquid. 30 parts by weight or less, more preferably 20 parts by weight or less, and particularly preferably 10 parts by weight or less. By setting the amount of the non-volatile base to be equal to or higher than the lower limit of the above range, sufficient adhesive strength can be obtained. Further, by setting the amount of the non-volatile base to be equal to or less than the upper limit of the above range, it is possible to prevent the color loss of the polyvinyl alcohol polarizer.

[4.2.4. particle〕
The coating liquid may further contain particles. The particles present in the coating liquid can be contained in the urethane resin layer as they are. As the particles, any of inorganic particles made of an inorganic material, organic particles made of an organic material, and composite particles containing a combination of an inorganic material and an organic material may be used. However, it is preferable to use water-dispersible particles from the viewpoint of easily forming the urethane resin layer. Moreover, it is preferable that an inorganic particle is included from a viewpoint of suppressing the blocking of a laminated film effectively. Examples of inorganic particles include inorganic oxides such as silica, titania, alumina, zirconia; calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, calcium phosphate Etc. Moreover, when the material of an organic particle is mentioned, a silicone resin, a fluororesin, an acrylic resin etc. will be mentioned, for example. One of these may be used alone, or two or more of these may be used in combination at any ratio.

  Of these exemplified particle materials, silica is preferred. Silica particles are excellent in ability to suppress the occurrence of blocking and transparency, hardly cause internal haze, and have no coloration, and therefore have little influence on the optical properties of the laminated film. Silica has good dispersibility and dispersion stability in the coating solution. Among the silica particles, amorphous colloidal silica particles are particularly preferable.

  Commercially available products may be used as the silica particles as described above. Examples of commercially available products include Eposter MX-050W (average particle size 80 nm), Seahoster KE-W10 (average particle size 110 nm), Eposter MX-100W (average particle size 150 nm to 200 nm) manufactured by Nippon Shokubai Co., Ltd .; Nissan Examples include Snowtex MP-2040 (average particle size: 150 nm to 200 nm) manufactured by Kagaku Co., Ltd. Unless otherwise specified, the particle size distribution of these particles is measured by laser diffraction method, and the measured particle size distribution adopts the particle size at which the cumulative volume calculated from the small diameter side is 50%. sell.

  When the coating liquid contains particles, protrusions can be formed on the surface of the urethane resin layer formed using the coating liquid by adjusting the diameter of the particles. By forming such protrusions, the slipperiness of the surface of the urethane resin layer can be improved, and blocking of the laminated film can be suppressed. At this time, since there is usually a correlation between the particle diameter and the height of the protrusion, the particle diameter can be set according to the slipperiness required for the surface of the coating liquid layer.

  Among these, it is preferable to use a combination of particles (S) having an average particle diameter of less than 150 nm and particles (L) having an average particle diameter of 150 nm or more.

  The average particle diameter of the particles (S) is preferably 20 nm or more, more preferably 30 nm or more, particularly preferably 40 nm or more, preferably less than 150 nm, more preferably 140 nm or less, particularly preferably 130 nm or less. By making the average particle diameter of the particles (S) equal to or greater than the lower limit of the above range, protrusions can be stably formed on the surface of the urethane resin layer, so that the slipperiness of the surface of the urethane resin layer can be effectively enhanced. it can. Moreover, the increase in the internal haze of the urethane resin layer by particle | grains can be suppressed by making the average particle diameter of particle | grains (S) below into the upper limit of the said range.

  The average particle diameter of the particles (S) is preferably at least 3 times, more preferably at least 4 times, particularly preferably at least 5 times, preferably at most 10 times, more preferably the thickness of the urethane resin layer. It is 8 times or less, particularly preferably 7 times or less. By making the average particle diameter of the particles (S) equal to or greater than the lower limit of the above range, protrusions can be stably formed on the surface of the urethane resin layer, so that the slipperiness of the surface of the urethane resin layer can be effectively enhanced. it can. Moreover, the increase in the internal haze of the urethane resin layer by particle | grains can be suppressed by making the average particle diameter of particle | grains (S) below into the upper limit of the said range.

  The amount of the particles (S) is preferably 2 parts by weight or more, more preferably 3 parts by weight or more, particularly preferably 5 parts by weight or more, preferably 24 parts by weight with respect to 100 parts by weight of the polymer contained in the coating liquid. Part or less, more preferably 20 parts by weight or less, and particularly preferably 18 parts by weight or less. By keeping the amount of the particles (S) within the above range, the slipperiness of the surface of the urethane resin layer can be enhanced while suppressing an increase in internal haze of the urethane resin layer.

  The average particle size of the particles (L) is preferably 150 nm or more, more preferably 160 nm or more, particularly preferably 170 nm or more, and preferably 250 nm or less, more preferably 230 nm or less, particularly preferably 200 nm or less. By making the average particle diameter of the particles (L) equal to or greater than the lower limit of the above range, the surface slipperiness of the urethane resin layer can be effectively enhanced. Moreover, the internal haze of a urethane resin layer can be made small by making the average particle diameter of particle | grains (L) below into the upper limit of the said range.

  The average particle diameter of the particles (L) is preferably 2 times or more, more preferably 3 times or more, particularly preferably 4 times or more, preferably 10 times or less, more preferably with respect to the thickness of the urethane resin layer. It is 8 times or less, particularly preferably 7 times or less. By making the average particle diameter of the particles (L) equal to or greater than the lower limit of the above range, the surface slipperiness of the urethane resin layer can be effectively enhanced. Moreover, the internal haze of a urethane resin layer can be made small by making the average particle diameter of particle | grains (L) below into the upper limit of the said range.

  The difference between the average particle size of the particles (S) and the average particle size of the particles (L) is preferably 70 nm or more, more preferably 100 nm or more, particularly preferably 120 nm or more, preferably 200 nm or less, more preferably 180 nm. Hereinafter, it is particularly preferably 160 nm or less. By keeping the difference between the average particle size of the particles (S) and the average particle size of the particles (L) within the above range, the increase in internal haze of the urethane resin layer is suppressed, and the slipping property of the surface of the urethane resin layer is reduced. Can be increased.

  The amount of the particles (L) is preferably 5 parts by weight or more, more preferably 6 parts by weight or more, particularly preferably 7 parts by weight or more, preferably 20 parts by weight, based on 100 parts by weight of the polymer contained in the coating liquid. Part or less, more preferably 18 parts by weight or less, and particularly preferably 15 parts by weight or less. By keeping the amount of the particles (L) within the above range, it is possible to improve the slipperiness of the surface of the urethane resin layer while suppressing an increase in internal haze of the urethane resin layer.

  The difference between the amount of the particles (L) and the amount of the particles (S) is preferably 0.5 parts by weight or more, more preferably 1 part by weight or more, particularly 100 parts by weight of the polymer contained in the coating liquid. The amount is preferably 2 parts by weight or more, preferably 25 parts by weight or less, more preferably 20 parts by weight or less, and particularly preferably 15 parts by weight or less. By keeping the difference between the amount of the particles (L) and the amount of the particles (S) within the above range, it is possible to improve the slipperiness of the surface of the urethane resin layer while suppressing an increase in internal haze of the urethane resin layer. it can.

[4.2.5. (Wetting agent)
The coating solution may further contain a wetting agent. By using the wetting agent, the coating property when the coating liquid is applied to the base material layer can be improved.

As the wetting agent, for example, an acetylene surfactant, a fluorine surfactant, or the like can be used. As the acetylene-based surfactant, for example, Surfynol series, Dynol series manufactured by Air Products and Chemicals, Inc. can be used. Moreover, as a fluorine-type surfactant, DIC Corporation mega-fac series, Neos company's tangent series, AGC company's Surflon series, etc. can be used, for example. As the wetting agent, it is preferable to use an acetylene surfactant from the viewpoint of overcoatability.
Moreover, these may be used individually by 1 type and may be used combining two or more types by arbitrary ratios.

  The amount of the wetting agent is preferably 0.01% by weight or more, more preferably 0.05% by weight or more, particularly preferably 0.1% by weight or more, preferably based on the solid content contained in the coating liquid. Is 5% by weight or less, more preferably 4 parts by weight or less, and particularly preferably 3% by weight or less. By setting the amount of the wetting agent to be equal to or higher than the lower limit of the above range, sufficient coatability can be obtained. Moreover, by setting the amount of the wetting agent to be equal to or less than the upper limit of the above range, wetting out of the wetting agent can be suppressed, and further, the overcoatability can be improved.

[4.2.6. (Other components of coating liquid)
The coating liquid may contain components other than those described above as long as the effects of the present invention are not significantly impaired. Examples of such components include heat stabilizers, weather stabilizers, leveling agents, surfactants, antioxidants, antistatic agents, slip agents, antiblocking agents, antifogging agents, lubricants, dyes, pigments, natural Oil, synthetic oil, wax and the like. One of these may be used alone, or two or more of these may be used in combination at any ratio.

[4.3. Urethane resin layer formation method: urethane resin layer formation with coating solution]
Prior to the application of the coating liquid to the base material layer, the base material layer can be pretreated as necessary. Examples of such pretreatment include preliminary stretching of the base material layer and surface treatment of the base material layer. Specific examples of the surface treatment include discharge treatment such as corona discharge treatment.

  Application | coating of the coating liquid to a base material layer can be performed using a known coating apparatus. Moreover, you may perform the scraping process which scrapes off the excess coating liquid after coating by a coating device. The thickness of the resulting coating liquid layer can be appropriately adjusted so that the finally formed urethane resin layer has a desired thickness.

  After the coating step, the urethane resin layer can be formed by curing the coating liquid layer on the base material layer. Simultaneously with the curing of the coating liquid layer, the substrate layer may be stretched. That is, the curing process and the stretching process may overlap part or all of the processes.

  The stretching temperature is preferably set to an appropriate temperature so that desired properties can be expressed in the base material layer by stretching and the coating liquid can be cured. The specific range of the stretching temperature can be set relative to the glass transition temperature Tg of the thermoplastic resin constituting the base material layer. The stretching temperature is preferably Tg + 3 ° C. or higher, more preferably Tg + 5 ° C. or higher, particularly preferably Tg + 8 ° C. or higher, preferably Tg + 30 ° C. or lower, more preferably Tg + 25 ° C. or lower, more preferably Tg + 20 ° C. or lower.

  The draw ratio can be arbitrarily set according to the characteristics desired to be manifested in the laminated film. For example, when producing a laminated film that can function as a retardation film, the specific range of the draw ratio is preferably 1.1 times or more, more preferably 1.2 times or more, and particularly preferably 1.3 times or more. Yes, preferably 5.0 times or less, more preferably 2.5 times or less, particularly preferably 2.0 times or less.

  When the laminated film is produced as a long film, the stretching direction when stretching the base material layer is the film longitudinal direction, the film width direction, the oblique direction that is neither parallel nor perpendicular to the film width direction, or these It can be a combination of stretching.

  The thickness of the urethane resin layer is preferably 10 nm or more, more preferably 15 nm or more, particularly preferably 20 nm or more, preferably 150 nm or less, more preferably 100 nm or less, particularly preferably 70 nm or less.

[5. Polarizer〕
The polarizing plate of the present invention includes the laminated film of the present invention and a polarizer layer provided on the surface of the laminated film on the urethane resin layer side via an adhesive layer. That is, the polarizing plate of the present invention has a layer structure of (conductive hard coat layer) / (thermoplastic resin layer having an ultraviolet absorption function) / (urethane resin layer) / (adhesive layer) / (polarizer). .

  Any polarizer can be used. As a polarizer, what is obtained by carrying out an extending | stretching process after doping iodine etc. to the polyvinyl alcohol-type film is common.

  The polarizing plate of this invention can be equipped with arbitrary layers in addition to a laminated film, an adhesive bond layer, and a polarizer layer as needed. For example, the protective film provided in the surface on the opposite side to a laminated | multilayer film of a polarizer can be provided. Such a protective film can also be provided via an adhesive layer, similarly to the laminated film.

  The polarizing plate of the present invention includes the laminated film of the present invention as a constituent element, and the laminated film can suppress undesired phenomena such as blocking when used as a film roll. Therefore, the polarizing plate of the present invention has a high degree of freedom in the process of preparing, storing and transporting its constituent elements and can be easily manufactured.

  Furthermore, when the polarizing plate of the present invention is provided in the display device in such a manner that the surface on the conductive hard coat layer side is the display surface side of the device, the adhesion can be maintained even after a long period of use. That is, when using a laminated film in a display device, transmission of ultraviolet light from the outside of the device can be reduced in the base material layer, thereby reducing the amount of ultraviolet light reaching the inside of the device from the urethane resin layer. be able to. As a result, even after a long period of use, the adhesiveness between the laminated film and the polarizer layer, the adhesiveness between the layers in the laminated film, and the adhesiveness between the layers inside the device from the base material layer is in a good state. Can be maintained.

  Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples, and can be implemented with any modifications without departing from the scope of the claims of the present invention and the equivalents thereof. In the following description, “%” and “part” representing amounts are based on weight unless otherwise specified. In addition, the operations described below were performed under normal temperature and normal pressure conditions unless otherwise specified.

[Evaluation method]
[Adhesion test after light irradiation load]
The polarizing plate for evaluation obtained in Examples and Comparative Examples was cut to a size of 50 mm × 50 mm, the polarizer side was bonded to the surface of a blue plate glass plate (thickness 0.7 mm) with an adhesive, and polarized light A plate-glass plate laminate was obtained. At this time, a double-sided adhesive tape (manufactured by Nitto Denko Corporation, product number “CS9621”) was used as the adhesive. The surface of the polarizing plate-glass plate laminate on the conductive hard coat layer side was irradiated with ultraviolet rays. Irradiation was performed using an ultraviolet auto fade meter (U48AUB: manufactured by Suga Test Instruments Co., Ltd.) under the conditions of 500 W / m ² and a black panel temperature of 63 ° C. In order to evaluate the adhesion between the conductive hard coat layer and the substrate 300 hours after the start of irradiation, in accordance with the JIS K5400 cross-cut test, 100 mm of 1 mm × 1 mm is cut into the conductive hard coat layer. A cross-cut test was conducted. In the case where the number of peeled cells was larger than 2 cells, it was determined as an adhesion failure.
Moreover, it cut | disconnected with the cutter from the edge part and surface of the polarizing plate-glass board laminated body 300 hours after the start of irradiation. And the polarizing plate-glass plate laminated body was pulled, and the cutter peeling test was implemented. As a result, when peeling occurred between the polarizer and the laminated film or within the laminated film, it was regarded as poor adhesion.
When the number of squares peeled off in the cross cut test was 2 squares or less and peeling occurred between the polarizer and the glass substrate in the cutter peeling test, the adhesion was considered good.

[Evaluation of roll winding property]
When the conductive hard coat side of the laminated film and the layer opposite to the conductive hard coat are brought into direct contact and wound into a roll of 500 m or more, the conductive hard coat side and the layer opposite to the conductive hard coat are in close contact with each other. Then, the one where blocking occurred was regarded as defective.

[Example 1]
(1-1. Production of conductive agent composition)
Methyl ethyl ketone was added as a diluent solvent to Pertron XJC-0639 (manufactured by Pernox Co., Ltd.), which is a conductive agent, to obtain an active energy ray-curable conductive agent composition having a solid content of 20% by weight.

(1-2. Production of Polarizer)
A polyvinyl alcohol film having a thickness of 80 μm was dyed in a 0.3% iodine aqueous solution. Thereafter, the dyed polyvinyl alcohol film was stretched up to 5 times in 4% boric acid aqueous solution and 2% potassium iodide aqueous solution, and then dried at 50 ° C. for 4 minutes to produce a polarizer.

(1-3. Preparation of urethane coating solution)
100 parts of an aqueous dispersion of polyether-based polyurethane ("Superflex 870" manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) in an amount of polyurethane, and 20 parts of an epoxy compound ("Denacol EX521" manufactured by Nagase ChemteX) as a crosslinking agent, 5 parts of adipic acid dihydrazide as a non-volatile base, 5 parts of silica particle water dispersion (Nissan Chemical “Snowtex MP2040”; average particle diameter 200 nm) as a lubricant and an amount of silica particles in water dispersion Liquid (Nissan Chemical “Snowtex XL”; average particle size 50 nm) is 8 parts by weight of silica particles, and acetylene surfactant (“Dynol 604” manufactured by Air Products and Chemicals) as a wetting agent is solid content. 1% by weight with respect to the total amount and water were blended to obtain a urethane coating solution having a solid concentration of 4%.

(1-4. Production of UV-absorbing thermoplastic resin)
A twin screw extruder (manufactured by Toshiba Corporation, ratio L / D = 42 of screw length L to screw diameter D) was prepared, which was provided with a screw having a total length of 1848 mm and a diameter of 44 mm. This screw had a total of three kneading zones at positions where the distance from the upstream end of the screw was 685 mm, 920 mm and 1190 mm. Here, the distance from the upstream end of the screw to the position of the kneading zone refers to the distance from the upstream end of the screw to the upstream end of the kneading zone. Further, upstream means upstream in the resin flow direction. Further, the ratio Lnx / D between the length Lnx of each kneading zone and the diameter D of the screw was Lnx / D = 4, Lnx / D = 2 and Lnx / D = 2 in order from the upstream kneading zone. It was.

  6. In this twin-screw extruder, 100 parts of a polymer containing an alicyclic structure (manufactured by Nippon Zeon Co., Ltd., glass transition temperature 126 ° C.) and a benzotriazole ultraviolet absorber (“LA-31” manufactured by ADEKA) 5 parts was added and kneaded to obtain a resin (A1) containing an ultraviolet absorber at a content of 7.0%.

(1-5. Production of unstretched film)
A double flight type single screw extruder (screw diameter D = 50 mm, screw length L to screw diameter D ratio L / D = 28) equipped with a leaf disk-shaped polymer filter with a mesh opening of 3 μm was prepared. . The resin (A1) was introduced into this single screw extruder, melted, and supplied to a single layer die through a feed block. The resin (A1) was introduced into the single screw extruder through a hopper loaded in the single screw extruder. Moreover, the surface roughness (arithmetic mean roughness Ra) of the die slip of the single-layer die was 0.1 μm. Furthermore, the extruder exit temperature of resin (A1) was 260 ° C.

  On the other hand, a single-screw extruder (screw diameter D = 50 mm, screw length L / screw diameter D ratio L / D = 30) having a leaf disk-shaped polymer filter with a mesh opening of 3 μm was prepared. . A polymer containing the same alicyclic structure as that contained in the resin (A1) (manufactured by Nippon Zeon Co., Ltd., glass transition temperature 126 ° C.) is introduced into this single-screw extruder as a resin (B1) and dissolved. And fed to the single-layer die through a feed block. The extruder outlet temperature of the resin (B1) was 260 ° C.

  Thereafter, the resin (A1) and the resin (B1) are discharged so as to be discharged into a film including three layers of a resin (B1) layer, a resin (A1) layer, and a resin (B1) layer. , And was discharged from a single-layer die in a molten state at 260 ° C. (coextrusion molding process). And the discharged resin was cast to a cooling roll whose temperature was adjusted to 100 ° C., and passed through a cooling roll whose temperature was adjusted to 50 ° C. to obtain a long unstretched film. When the resin was discharged from the single-layer die and cast onto a cooling roll, the air gap amount was set to 50 mm. Further, edge pinning was adopted as a method for casting the molten film-like resin to a cooling roll.

  The obtained unstretched film was a two-type three-layer film including a layer made of the resin (B1), a layer made of the resin (A1), and a layer made of the resin (B1) in this order. The total thickness of this unstretched film was 25 μm. The ratio of the thickness of the layer made of the resin (A1) to the total thickness of the two layers made of the resin (B1) was 0.92. Thereafter, both ends of the unstretched film were trimmed to a width of 1500 mm.

(1-6. Production of laminated film)
On the surface of the trimmed unstretched film obtained in (1-5) under the conditions of an output of 500 W, an electrode length of 1.35 m, and a conveyance speed of 15 m / min, using a corona treatment device (Kasuga Denki Co., Ltd.) Discharge treatment was performed. The urethane coating solution obtained in (1-3) was applied to the surface of the unstretched film subjected to the discharge treatment using a roll coater so that the coating thickness after drying was 45 nm. Then, using a tenter-type transverse stretching machine, the film is gripped by clips at both ends and continuously transported at a drying temperature of 140 ° C. at a stretching ratio of 1.0 (that is, transported through a transport path without stretching). In addition, both left and right ends were cut to a width of 1330 mm. By the operation so far, the unstretched film was stretched to become a UV-absorbing thermoplastic resin base material layer, and the urethane coating solution was cured to become a urethane resin layer containing inorganic particles. This obtained the elongate intermediate body laminate (1) which has a layer structure of (base material layer) / (urethane resin layer). The intermediate laminate (1) was wound so that the urethane resin layer was unwound to obtain a film roll.

Thereafter, the intermediate laminate (1) was fed out from the obtained film roll, and a corona treatment (output 0.4 kW, discharge amount 200 W · min / m ² ) was performed on the surface on the base material layer side. On this surface, the conductive agent composition obtained in (1-1) was applied using a die coater to form a film of the conductive agent composition. The conductive agent composition was applied in an environment with a relative humidity of 50%, and the thickness of the conductive agent composition film was adjusted so that the thickness of the conductive hard coat layer obtained after curing was 1.5 μm.

Then, after drying this conductive agent composition film at 80 ° C. for 1 minute, the conductive agent composition film was irradiated with 300 mJ / cm ² of light with a high-pressure mercury lamp to cure the conductive agent composition, A hard coat layer was formed. Thus, a laminated film having a layer configuration of (conductive hard coat layer) / (base material layer) / (urethane resin layer) was obtained.

  The obtained laminated film was wound into a roll shape in a state where the surface on the conductive hard coat side and the surface on the urethane resin layer side were in direct contact, and the roll winding property was evaluated. The roll winding property was good.

(1-7. Polarizing plate)
The laminated film obtained in (1-6) was cut into a rectangular laminated film of 80 mm × 80 mm. On the other hand, the polarizer manufactured in (1-2) was cut into a rectangular polarizer of 80 mm × 80 mm. Corona treatment was applied to the urethane resin layer side surface of the rectangular laminated film and one surface of the rectangular polarizer. The corona-treated surface of the rectangular laminated film was bonded to the corona-treated surface of the rectangular polarizer. Bonding was performed by applying an adhesive to both surfaces and combining the surfaces to which the adhesive was applied. At this time, UV adhesive CRB series (manufactured by Toyochem) was used as the adhesive. Thereafter, the bonded product was irradiated with ultraviolet rays to cure the adhesive. For ultraviolet irradiation, an electrodeless UV irradiation apparatus (manufactured by Heraeus) is used, the lamp is a D bulb, and the polarizer side is directed to the UV lamp side under the conditions of a peak illuminance of 100 mW / cm ² and an integrated light amount of 3000 mJ / cm ^2. This was performed by irradiating with ultraviolet rays. Thereby, a polarizing plate for evaluation having a layer configuration of (conductive hard coat layer) / (base material layer) / (urethane resin layer) / (adhesive layer) / (polarizer) was obtained. About the obtained polarizing plate, when the adhesiveness test after light irradiation load was done, adhesion was favorable.

[Example 2]
(2-1. Production of UV-absorbing thermoplastic resin)
A twin screw extruder (manufactured by Toshiba Corporation, ratio L / D = 42 of screw length L to screw diameter D) was prepared, which was provided with a screw having a total length of 1848 mm and a diameter of 44 mm. This screw had a total of three kneading zones at positions where the distance from the upstream end of the screw was 685 mm, 920 mm and 1190 mm. Here, the distance from the upstream end of the screw to the position of the kneading zone refers to the distance from the upstream end of the screw to the upstream end of the kneading zone. Further, upstream means upstream in the resin flow direction. Further, the ratio Lnx / D between the length Lnx of each kneading zone and the diameter D of the screw was Lnx / D = 4, Lnx / D = 2 and Lnx / D = 2 in order from the upstream kneading zone. It was.

  7. In this twin-screw extruder, 100 parts of a polymer containing an alicyclic structure (manufactured by ZEON Corporation, glass transition temperature 126 ° C.) and a benzotriazole ultraviolet absorber (“LA-31” made by ADEKA) 5 parts was added and kneaded to obtain a resin (C1) containing an ultraviolet absorber at a content of 7.8%.

(2-2. Production of unstretched film)
A double flight type single screw extruder (screw diameter D = 50 mm, screw length L to screw diameter D ratio L / D = 28) equipped with a leaf disk-shaped polymer filter with a mesh opening of 3 μm was prepared. . The resin (C1) was introduced into this single screw extruder, melted, and supplied to a single layer die through a feed block. The resin (C1) was introduced into the single screw extruder through a hopper loaded in the single screw extruder. Moreover, the surface roughness (arithmetic mean roughness Ra) of the die slip of the single-layer die was 0.1 μm. Furthermore, the extruder exit temperature of resin (C1) was 260 ° C.

  On the other hand, a single-screw extruder (screw diameter D = 50 mm, screw length L / screw diameter D ratio L / D = 30) having a leaf disk-shaped polymer filter with a mesh opening of 3 μm was prepared. . A polymer containing the same alicyclic structure as that contained in the resin (C1) (manufactured by Nippon Zeon Co., Ltd., glass transition temperature 126 ° C.) is introduced into this single-screw extruder as a resin (D1) and dissolved. And fed to the single-layer die through a feed block. The extruder outlet temperature of the resin (D1) was 260 ° C.

  Thereafter, the resin (C1) and the resin (D1) are discharged so as to be discharged into a film including three layers of a resin (D1) layer, a resin (C1) layer, and a resin (D1) layer. , And was discharged from a single-layer die in a molten state at 260 ° C. (coextrusion molding process). And the discharged resin was cast to a cooling roll whose temperature was adjusted to 100 ° C., and passed through a cooling roll whose temperature was adjusted to 50 ° C. to obtain a long unstretched film. When the resin was discharged from the single-layer die and cast onto a cooling roll, the air gap amount was set to 50 mm. Further, edge pinning was adopted as a method for casting the molten film-like resin to a cooling roll.

  The obtained unstretched film was a two-type three-layer film including a layer made of the resin (D1), a layer made of the resin (C1), and a layer made of the resin (D1) in this order. The total thickness of this unstretched film was 35 μm. The ratio of the thickness of the layer made of the resin (C1) to the total thickness of the two layers made of the resin (D1) was 1.06. Thereafter, both ends of the unstretched film were trimmed to a width of 1300 mm.

(2-3. Production of laminated film)
Using a corona treatment device (manufactured by Kasuga Denki Co., Ltd.), on the surface of the trimmed unstretched film obtained in (2-2) under the conditions of an output of 800 W, an electrode length of 1.35 m, and a conveyance speed of 30 m / min. Discharge treatment was performed. The urethane coating liquid obtained in (1-3) of Example 1 was applied to the surface of the unstretched film subjected to the discharge treatment using a roll coater so that the coating thickness after drying was 45 nm. Then, using a tenter-type stretching machine, the film is stretched at a stretch ratio of 1.4 times in an oblique direction that is neither parallel nor perpendicular to the longitudinal direction of the unstretched film, and the left and right ends are further stretched to a width of 1330 mm. Cut. By the operation so far, the unstretched film was stretched to become a UV-absorbing thermoplastic resin base material layer, and the urethane coating solution was cured to become a urethane resin layer containing inorganic particles. This obtained the elongate intermediate body laminate (2) which has the layer structure of (base material layer) / (urethane resin layer). The intermediate laminate (2) was wound so that the urethane resin layer was unwound to obtain a film roll.
Thereafter, the intermediate laminate (2) was fed out from the obtained film roll, and the surface on the base material layer side was subjected to corona treatment (output 0.4 kW, discharge amount 200 W · min / m ² ). On this surface, the conductive agent composition obtained in (1-1) of Example 1 was applied using a die coater to form a film of the conductive agent composition. The conductive agent composition was applied in an environment with a relative humidity of 50%, and the thickness of the conductive agent composition film was adjusted so that the thickness of the conductive hard coat layer obtained after curing was 1.5 μm.

Then, after drying this conductive agent composition film at 80 ° C. for 1 minute, the conductive agent composition film is irradiated with 300 mJ / cm ² of light with a high-pressure mercury lamp to cure the conductive agent composition film. A conductive hard coat layer was formed. Thus, a laminated film having a layer configuration of (conductive hard coat layer) / (base material layer) / (urethane resin layer) was obtained. The obtained laminated film was wound up in a roll shape.

  The obtained laminated film was wound into a roll shape in a state where the surface on the conductive hard coat side and the surface on the urethane resin layer side were in direct contact, and the roll winding property was evaluated. The roll winding property was good.

(2-4. Polarizing plate)
Instead of the laminated film obtained in Example 1 (1-6), except that the laminated film obtained in (2-3) was used, the same operation as in Example 1 (1-7) was carried out. A polarizing plate for evaluation was obtained and evaluated. As a result, the adhesion after the light irradiation load was good.

[Comparative Example 1]
(C1-1. Production of laminated film)
In the production of the laminated film of (1-6), except that the corona treatment and application of the conductive agent composition to the intermediate laminate (1) were performed on the surface of the urethane resin layer instead of the surface of the base material layer. Were evaluated by obtaining a laminated film by the same operation as (1-1) to (1-6) in Example 1. The obtained laminated film had a layer structure of (conductive hard coat layer) / (urethane resin layer) / (base material layer). The roll winding property was poor because blocking occurred between the conductive hard coat layer and the base material layer.

(C1-2. Polarizing plate)
Further, instead of the laminated film obtained in (1-6), the laminated film obtained in (C1-1) is used, and the laminated film is subjected to corona treatment on the surface on the base material layer side, and this surface is polarized. The polarizing plate was obtained and evaluated by the same operation as (1-7) of Example 1 except that it was bonded to the child. As a result, in the cross cut test, peeling occurred in more than 2 squares between the conductive hard coat layer and the urethane resin layer, resulting in poor adhesion.

[Comparative Example 2]
Example 1 except that in the production of the unstretched film of (1-5), the resin (B1) was used instead of the resin (A1), and as a result, a film made of only the resin (B1) was produced as the unstretched film. By the same operation as (1-1) to (1-3) and (1-5) to (1-7), a laminated film and a polarizing plate were obtained and evaluated.
The obtained laminated film had a layer configuration of (conductive hard coat layer) / (thermoplastic resin layer) / (urethane resin layer). The roll winding property was good.
As a result of evaluation of the polarizing plate, peeling occurred between the urethane resin layer and the polarizer in the cutter peeling test, resulting in poor adhesion.

  From the above results, it can be seen that in the laminated film and the polarizing plate having the specific layer configuration of the present invention, good roll winding property and good adhesion after light irradiation load can be obtained.

Claims (5)

  A laminated film comprising a conductive hard coat layer, a base material layer, and a urethane resin layer in this order, wherein the base material layer is a layer of a thermoplastic resin having an ultraviolet absorbing function.   The laminated film according to claim 1, wherein the urethane resin layer contains inorganic particles.   The laminated film according to claim 1 or 2, wherein the thermoplastic resin includes a polymer containing an alicyclic structure.   The base material layer comprises a first outer layer made of a resin (B) containing a polymer containing an alicyclic structure, and a resin (A) containing a polymer containing an alicyclic structure and an ultraviolet absorber. The laminated film according to claim 3, comprising an intermediate layer and a second outer layer made of a resin (B ′) containing a polymer containing an alicyclic structure in this order.   A polarizing plate provided with the laminated film of any one of Claims 1-4, and the polarizer layer provided in the surface by the side of the said urethane resin layer of the said laminated film through an adhesive bond layer.