WO2024122353A1 - Film multicouche et procédé de fabrication d'un tel film multicouche - Google Patents

Film multicouche et procédé de fabrication d'un tel film multicouche Download PDF

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Publication number
WO2024122353A1
WO2024122353A1 PCT/JP2023/042085 JP2023042085W WO2024122353A1 WO 2024122353 A1 WO2024122353 A1 WO 2024122353A1 JP 2023042085 W JP2023042085 W JP 2023042085W WO 2024122353 A1 WO2024122353 A1 WO 2024122353A1
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Prior art keywords
easy
layer
film
polymer
adhesion layer
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PCT/JP2023/042085
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English (en)
Japanese (ja)
Inventor
祐二 柴田
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日本ゼオン株式会社
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Publication of WO2024122353A1 publication Critical patent/WO2024122353A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
    • B29C55/02—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
    • B32B27/20—Layered products comprising a layer of synthetic resin characterised by the use of special additives using fillers, pigments, thixotroping agents
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements

Definitions

  • the present invention relates to a multilayer film and a method for producing the same.
  • Multilayer films that have a base film and a resin layer that contains particles are known (see Patent Documents 1 to 3).
  • the adhesion between the substrate film and the functional layer, such as the optical functional layer may be insufficient.
  • an easy-adhesion layer may be provided on the substrate film to improve the adhesion with the functional layer.
  • particles may be included in the easy-adhesion layer.
  • the film has an easy-adhesion layer containing particles, the adhesion between the base film and the functional layer may be insufficient. Therefore, there is a need for a multilayer film having good adhesion between the base film and other functional layers; and a method for producing such a multilayer film having good adhesion.
  • the present inventors have conducted extensive research to solve the above problems, and have found that the above problems can be solved by a multilayer film including a base film, a specific easy-adhesion layer, an anchor layer, and a top layer, in which the total thickness (T1+T2) of the easy-adhesion layer thickness T1 and the anchor layer thickness T2 is a predetermined value or more, and have completed the present invention. That is, the present invention provides the following.
  • a multilayer film comprising a base film, an easy-adhesion layer provided in direct contact with one surface of the base film, an anchor layer provided in direct contact with the surface of the easy-adhesion layer, and a top layer provided in direct contact with the surface of the anchor layer,
  • the total thickness (T1 + T2) of the thickness T1 of the easy-adhesion layer and the thickness T2 of the anchor layer is 150 nm or more
  • the easy-adhesion layer contains organic particles (NP) having an average particle diameter T3 equal to or greater than the thickness T1 of the easy-adhesion layer, Multi-layer film.
  • the easy-adhesion layer is a cured product of an easy-adhesion layer material containing the organic particles (NP), a polymer (P1) having a (meth)acrylic acid ester unit, and a crosslinking agent (1).
  • NP organic particles
  • P1 polymer having a (meth)acrylic acid ester unit
  • a crosslinking agent (1) any one of the multilayer film described.
  • the anchor layer is a cured product of an anchor layer material containing a polymer (P2) having a (meth)acrylic acid ester unit and a crosslinking agent (2).
  • the easy-adhesion layer is a cured product of an easy-adhesion layer material containing the organic particles (NP), a polymer (P1) having a (meth)acrylic acid ester unit, and a crosslinking agent (1)
  • the anchor layer is a cured product of an anchor layer material containing a polymer (P2) having a (meth)acrylic acid ester unit and a crosslinking agent (2)
  • the multilayer film according to any one of [1] to [6], wherein the polymer (P1) and the polymer (P2) have a common (meth)acrylic acid ester unit.
  • a method for producing the multilayer film according to any one of [1] to [9], A step (1) of preparing a long substrate film; A step (2-1) of applying a liquid adhesive layer material onto the substrate film to form a coating film of the adhesive layer material; A step (2-2) of drying the coating film of the easy-adhesion layer material to form an easy-adhesion layer and obtain a multilayer body (I) having the base film and the easy-adhesion layer; A step (3) of stretching the multi-layered product (I) to obtain a multi-layered product (II); A step (4) of winding up the laminate (II); A step (5-1) of unwinding the wound multilayer material (II) and applying a liquid anchor layer material onto the easy-adhesion layer of the multilayer material (II) to form a coating film of the anchor layer material; A step (5-2) of drying the coating film of the anchor layer material to form an anchor layer, thereby obtaining a multilayer body (III) having the base film, the easy-a
  • the present invention provides a multilayer film having good adhesion between the base film and other functional layers; and a method for producing such a multilayer film having good adhesion.
  • a "long" film refers to a film that is 5 times or more longer than its width, and preferably 10 times or more longer, specifically a film long enough to be wound into a roll for storage or transportation. There is no particular upper limit to the length of the film, and it can be, for example, 100,000 times or less than its width.
  • the slow axis of a film or layer refers to the slow axis in the plane of the film or layer, unless otherwise specified.
  • orientation angle of a film or layer refers to the angle that the slow axis of the film or layer makes with the longitudinal direction of the film or layer.
  • the angle between the optical axes (slow axis, transmission axis, absorption axis, etc.) of each layer in a component having multiple layers represents the angle when the layer is viewed from the thickness direction, unless otherwise specified.
  • the diagonal direction of a long film refers to an in-plane direction of the film that is neither parallel nor perpendicular to the longitudinal direction of the film.
  • nx represents the refractive index in the direction perpendicular to the thickness direction of the layer (in-plane direction) that gives the maximum refractive index.
  • ny represents the refractive index in the in-plane direction of the layer that is perpendicular to the direction of nx.
  • d represents the thickness of the layer.
  • the measurement wavelength is 550 nm, unless otherwise specified.
  • the directions of elements as “parallel,” “vertical,” and “orthogonal” may include an error within a range that does not impair the effect of the present invention, for example, within the range of ⁇ 3°, ⁇ 2°, or ⁇ 1°.
  • a "resin with positive inherent birefringence” refers to a resin whose refractive index in the stretching direction is greater than the refractive index in the direction perpendicular to the stretching direction.
  • a “polymer with positive inherent birefringence” refers to a polymer whose refractive index in the stretching direction is greater than the refractive index in the direction perpendicular to the stretching direction, unless otherwise specified.
  • (meth)acrylic includes “acrylic", “methacrylic” and combinations thereof.
  • (meth)acrylic acid encompasses “acrylic acid,”"methacrylicacid,” and combinations thereof.
  • (meth)acrylonitrile includes “acrylonitrile", “methacrylonitrile”, and combinations thereof.
  • (meth)acrylate encompasses “acrylate,”"methacrylate,” and combinations thereof.
  • a polymerized unit having a structure formed by polymerization of a certain monomer may be expressed using the name of that monomer.
  • a unit having a structure formed by polymerization of a (meth)acrylic acid ester may be referred to as a "(meth)acrylic acid ester unit.”
  • a unit having a structure formed by polymerization of a styrene-based monomer may be referred to as a "styrene-based monomer unit.”
  • a polymer containing a styrene-based monomer unit may simply be referred to as a styrene-based polymer.
  • the structure of the molecule and its components is not limited by the manufacturing method.
  • a layer A is provided in direct contact with one surface of a layer B" means that there is no other layer between one surface of layer B and layer A.
  • a multilayer film according to one embodiment of the present invention includes a substrate film, an easy-adhesion layer provided directly on one surface of the substrate film, an anchor layer provided directly on the surface of the easy-adhesion layer, and a top layer provided directly on the surface of the anchor layer.
  • the total thickness (T1+T2) of the easy-adhesion layer thickness T1 and the anchor layer thickness T2 is 150 nm or more, and the easy-adhesion layer contains organic particles (NP) whose average particle diameter T3 is equal to or greater than the thickness T1 of the easy-adhesion layer.
  • the multilayer film having one each of an easy-adhesion layer, an anchor layer, and a top layer will be mainly described as an example.
  • the present invention is not limited thereto.
  • the multilayer film may have an easy-adhesion layer, an anchor layer, and a top layer provided on both main surfaces of a single-layer base film.
  • the multilayer film has the above-mentioned structure, making it possible to produce a film with good adhesion.
  • adhesion is an index of resistance to peeling between the base film and the top layer.
  • the laminate of the base film and the easy-adhesion layer produced in the middle has good slip properties, so that the laminate is less likely to be scratched even if it is rolled up during production, and can be smoothly unrolled. Therefore, a multilayer film with good adhesion can be easily produced.
  • the total thickness (T1+T2) is preferably 80 nm or more, more preferably 100 nm or more, even more preferably 110 nm or more, even more preferably 150 nm or more, even more preferably 160 nm or more, even more preferably 165 nm or more, and from the viewpoint of minimizing the effect on the optical properties of the multilayer film, it is preferably 800 nm or less, more preferably 700 nm or less, even more preferably 500 nm or less.
  • the thickness of the layers in the multilayer film can be measured using a spectroscopic reflection film thickness measuring device (e.g., the F20 spectroscopic reflection film thickness measuring system manufactured by Filmetrics).
  • a spectroscopic reflection film thickness measuring device e.g., the F20 spectroscopic reflection film thickness measuring system manufactured by Filmetrics.
  • the ratio (T1/T3) of the thickness T1 of the easy-adhesion layer to the average particle diameter T3 of the organic particles (NP) is usually 1/1 or less (i.e., 1 or less), preferably 0.8 or less, more preferably 0.6 or less, and even more preferably 0.46 or less, and may usually be greater than 0, for example, 0.1 or more.
  • T1/T3 is within the above range, both the adhesion of the multilayer film and the surface condition of the multilayer film can be improved.
  • the average particle diameter T3 of the organic particles (NP) is, for example, 100 nm or more, for example, 150 nm or more, and is, for example, 1000 nm or less, for example, 800 nm or less.
  • the average particle diameter T3 of the organic particles (NP) is the weight average particle diameter measured by dynamic light scattering.
  • the base film may be a film containing a thermoplastic resin.
  • the thermoplastic resin that may be contained in the base film may be referred to as a thermoplastic resin (s).
  • the base film may be a film made of only the thermoplastic resin (s).
  • the thermoplastic resin (s) is a thermoplastic resin containing a polymer and further containing an optional component as necessary.
  • a resin having a negative inherent birefringence may be used as the thermoplastic resin (s)
  • a resin having a positive inherent birefringence is preferred from the viewpoint of easily manufacturing a multilayer film as a broadband wavelength film.
  • Resins having positive intrinsic birefringence usually include polymers having positive intrinsic birefringence.
  • polymers having positive intrinsic birefringence include polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyarylene sulfides such as polyphenylene sulfide; polyvinyl alcohol; polycarbonate; polyarylate; cellulose ester polymers; polyethersulfone; polysulfone; polyarylsulfone; polyvinyl chloride; alicyclic structure-containing polymers such as norbornene-based polymers; rod-shaped liquid crystal polymers, and the like. These polymers may be used alone or in combination of two or more types in any ratio. The polymers may be homopolymers or copolymers.
  • Examples of cycloolefin-based polymers that contain an alicyclic structure include (1) norbornene-based polymers, (2) monocyclic olefin polymers, (3) cyclic conjugated diene polymers, (4) vinyl alicyclic hydrocarbon polymers, and hydrogenated products thereof. Of these, norbornene-based polymers are preferred. Examples of norbornene-based polymers include ring-opening polymers of norbornene monomers, ring-opening copolymers of norbornene monomers and other monomers that can be copolymerized by ring-opening, and hydrogenated products thereof; addition polymers of norbornene monomers, and addition copolymers of norbornene monomers and other monomers that can be copolymerized. Of these, hydrogenated products of ring-opening polymers of norbornene monomers are particularly preferred from the viewpoint of transparency.
  • the alicyclic structure-containing polymer is selected from the polymers disclosed in, for example, JP-A-2002-32
  • the polymer ratio in the thermoplastic resin (s) is preferably 50% to 100% by weight, more preferably 70% to 100% by weight, and particularly preferably 90% to 100% by weight. When the polymer ratio is within the above range, a multilayer film with excellent heat resistance and transparency can be produced.
  • the thermoplastic resin (s) may further contain optional components other than the polymer in combination with the polymer.
  • optional components include colorants such as pigments and dyes; plasticizers; fluorescent whitening agents; dispersants; heat stabilizers; light stabilizers; UV absorbers; antistatic agents; antioxidants; fine particles; surfactants, etc.
  • colorants such as pigments and dyes; plasticizers; fluorescent whitening agents; dispersants; heat stabilizers; light stabilizers; UV absorbers; antistatic agents; antioxidants; fine particles; surfactants, etc.
  • One of these components may be used alone, or two or more may be used in combination in any ratio.
  • the glass transition temperature TgA of the thermoplastic resin (s) is preferably 100°C or higher, more preferably 110°C or higher, particularly preferably 120°C or higher, and is preferably 190°C or lower, more preferably 180°C or lower, particularly preferably 170°C or lower.
  • the glass transition temperature TgA of the thermoplastic resin (s) is equal to or higher than the lower limit of the above range, the durability of the substrate film in a high-temperature environment can be improved.
  • the glass transition temperature TgA of the thermoplastic resin (s) is equal to or lower than the upper limit of the above range, the stretching process can be easily performed.
  • the glass transition temperature can be measured using a differential scanning calorimeter (manufactured by SII Nanotechnology, product name: DSC6220) at a heating rate of 10°C/min according to JIS-K7121.
  • thermoplastic resin (s) preferably does not contain particles.
  • "not containing" particles can also include the case where the resin does not substantially contain particles.
  • the case where the resin does not substantially contain particles means that the thermoplastic resin (s) contains particles, and the increase in haze of the base film compared to a state where the resin does not contain any particles is within a range of 0.05% or less.
  • the thickness of the base film is preferably 30 ⁇ m or more, more preferably 35 ⁇ m or more, particularly preferably 40 ⁇ m or more, and preferably 60 ⁇ m or less, more preferably 55 ⁇ m or less, particularly preferably 50 ⁇ m or less.
  • the output of the corona treatment is preferably set to a condition that minimizes damage to the surface to be treated, specifically, it is preferably 0.02 kW or more, more preferably 0.04 kW or more, and is preferably 5 kW or less, more preferably 2 kW or less.
  • the easy-adhesion layer contains organic particles (NP), and preferably contains a polymer in addition to the organic particles (NP).
  • the easy-adhesion layer is more preferably a cured product of the easy-adhesion layer material.
  • the easy-adhesion layer is provided to improve the slipperiness of a film produced intermediately in the production of a multilayer film.
  • the material preferably comprises a polymer (P1) and a cross-linking agent (1).
  • the (meth)acrylic monomer unit is a structural unit having a structure that can be obtained by polymerizing a (meth)acrylic monomer.
  • the (meth)acrylic monomer means (meth)acrylic acid and a derivative of (meth)acrylic acid.
  • Examples of the derivative of (meth)acrylic acid include (meth)acrylic acid esters, (meth)acrylamide, and (meth)acrylonitrile, and (meth)acrylic acid esters are preferred.
  • Examples of (meth)acrylic acid esters include alkyl (meth)acrylates, and the alkyl group in the alkyl (meth)acrylate may or may not have a substituent such as a hydroxyl group or a halogen atom.
  • the (meth)acrylic polymer may contain any monomer unit in addition to the (meth)acrylic monomer unit.
  • the (meth)acrylic polymer is preferably a crosslinked polymer containing a crosslinkable monomer unit.
  • the crosslinkable monomer unit is a unit that can be obtained by polymerizing a crosslinkable monomer.
  • crosslinkable monomer examples include polyfunctional monomers containing two or more polymerizable groups per molecule, specifically, divinylbenzene, ethylene glycol di(meth)acrylate, hexanediol di(meth)acrylate, pentaerythritol triacrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetraacrylate, diallyl phthalate, and triallyl cyanurate.
  • the crosslinkable monomer may be used alone or in combination of two or more types at any ratio.
  • particles containing (meth)acrylic acid ester units are preferred, and particles of a polymethyl methacrylate-based crosslinked polymer containing methyl methacrylate units and crosslinkable monomer units are more preferred.
  • organic particles may be used.
  • examples of commercially available organic particles include Nippon Shokubai's "Eposter (registered trademark) MX Series” (particles of polymethyl methacrylate-based cross-linked polymer), Soken Chemical Industry's “Chemisnow MP Series” (acrylic polymer particles), Soken Chemical Industry's “Chemisnow MX Series” (styrene-acrylic resin particles), and Sekisui Chemical Industry's "Techpolymer.”
  • the average particle diameter of the organic particles is usually equal to or larger than the thickness T1 of the easy-adhesion layer, preferably less than 450 nm, more preferably 400 nm or less, and even more preferably 350 nm or less.
  • the average particle diameter of the organic particles is within the above range, the organic particles are less likely to fall off from the easy-adhesion layer.
  • the slipperiness of the laminate of the substrate film and the easy-adhesion layer produced in the middle is improved.
  • the content of the organic particles in the easy-adhesion layer is usually the same as the weight ratio of the organic particles contained in the easy-adhesion material when the total amount of solids in the easy-adhesion layer material for forming the easy-adhesion layer is 100% by weight.
  • urethane resin a resin containing polyurethane or its crosslinked product as the polymer (P1) can be used.
  • polyurethane include polyurethanes derived from various polyols and polyisocyanates.
  • polyols include any one of aliphatic polyester polyols, polyether polyols, polycarbonate polyols, and polyethylene terephthalate polyols obtained by the reaction of a polyol compound with a polybasic acid; and mixtures thereof.
  • the polyol compound include ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, glycerin, trimethylolpropane, and the like.
  • polybasic acid examples include polybasic carboxylic acids such as polybasic carboxylic acids including dicarboxylic acids and tricarboxylic acids, or anhydrides thereof.
  • dicarboxylic acids include adipic acid, succinic acid, sebacic acid, glutaric acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, and the like.
  • tricarboxylic acids include trimellitic acid, and the like.
  • polyether polyol examples include poly(oxypropylene ether) polyol and poly(oxyethylene-propylene ether) polyol.
  • the unreacted hydroxyl groups remaining can be used as polar groups capable of crosslinking with the functional groups in the crosslinking agent.
  • a polycarbonate-based polyurethane derived from a polycarbonate-based polyol and polyisocyanate and containing a carbonate structure in its skeleton is preferred.
  • JP 2016-182568 A the description in JP 2016-182568 A can be referred to, for example.
  • water-based urethane resins are compositions containing polyurethane and water, and usually polyurethane and optional components contained as necessary are dispersed in water.
  • water-based urethane resins examples include the "ADEKA BONTITOR” series manufactured by ADEKA Corporation, the “OLESTAR” series manufactured by Mitsui Chemicals, Inc., the “BONDIC” series manufactured by DIC Corporation, the “HYDRAN (WLS201, WLS202, etc.)” series manufactured by Bayer, the "POISE” series manufactured by Kao Corporation, the "SANPRENE” series manufactured by Sanyo Chemical Industries, Ltd., the "SUPERFLEX” series manufactured by Daiichi Kogyo Seiyaku Co., Ltd., the "NEOREZ” series manufactured by Kusumoto Chemicals, Inc., and the "SANCURE” series manufactured by Lubrizol Corporation.
  • olefin resin a resin containing an acid-modified polyolefin or its crosslinked product having an unsaturated carboxylic acid component content of 0.1% by weight to 10% by weight as the polymer (P1) can be used.
  • Preferred examples of the olefin component that is the main component of the acid-modified polyolefin include alkenes having 2 to 6 carbon atoms, such as ethylene, propylene, isobutylene, 2-butene, 1-butene, 1-pentene, and 1-hexene, and mixtures thereof.
  • alkenes having 2 to 4 carbon atoms such as ethylene, propylene, isobutylene, and 1-butene
  • examples of the unsaturated carboxylic acid component that is the modified component of the acid-modified polyolefin include acrylic acid, methacrylic acid, maleic acid (anhydride), itaconic acid (anhydride), fumaric acid, crotonic acid, half esters of unsaturated dicarboxylic acids, and half amides.
  • acrylic acid, methacrylic acid, and maleic acid are preferred, and acrylic acid and maleic acid (anhydride) are particularly preferred, since they can increase the adhesion of the layer formed of the resin (hereinafter also referred to as the resin layer) and suppress cracking.
  • the unsaturated carboxylic acid component is usually copolymerized in the acid-modified polyolefin, and the form is not particularly limited. Examples of the copolymerization state include random copolymerization, block copolymerization, and graft copolymerization (graft modification).
  • the description in JP-A-2014-240174 can be referred to, for example.
  • aqueous dispersions include the "Arrowbase (Arrowbase SA-1200, Arrowbase SB-1200, Arrowbase SE-1200, Arrowbase SB-1010)" series (manufactured by Unitika Ltd.).
  • the polyester resin a resin containing a polyester or its crosslinked product obtained by the reaction of the polyol compound with the polybasic acid can be used as the polymer (P1).
  • the polyester for example, after the reaction between the polyol compound and the polybasic acid is completed, the unreacted hydroxyl group and carboxyl group remaining can be used as a polar group capable of crosslinking with a crosslinking agent.
  • the polyester may also be a copolymer of the polyol compound and the polybasic acid with a copolymer component having a polar group such as a hydroxyl group or a carboxyl group.
  • the polyester resin preferably further contains an acrylic polymer in combination with the polyester or its crosslinked product in order to improve the adhesion of the resin layer.
  • the description in JP 2015-024511 A may be referred to.
  • polyester commercially available products may be used.
  • examples of commercially available water-soluble or water-dispersible polyester products include the "Nichigo Polyester (Nichigo Polyester W-0030, Nichigo Polyester W-0005S30WO, Nichigo Polyester WR-961, etc.)” series (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and the "PES Resin A (PES Resin A-210, PES Resin A-520, PES Resin A-684G, PES Resin A-695GE, etc.)” series (manufactured by Takamatsu Oil Co., Ltd.).
  • any epoxy resin can be used, such as a one-component curing type epoxy resin or a two-component curing type epoxy resin.
  • those containing a water-soluble epoxy polymer as the polymer (P1) are preferable.
  • a preferable example of a water-soluble epoxy polymer is polyamide epoxy polymer.
  • This polyamide epoxy polymer is obtained by reacting epichlorohydrin with polyamide polyamine obtained by reacting polyalkylene polyamine such as diethylenetriamine or triethylenetetramine with dicarboxylic acid such as adipic acid.
  • Commercially available products of such polyamide epoxy polymers include "Sumirez Resin 650 (30)" and “Sumirez Resin 675" manufactured by Sumika Chemtech Co., Ltd.
  • This polyvinyl alcohol includes not only partially saponified polyvinyl alcohol and fully saponified polyvinyl alcohol, but also modified polyvinyl alcohols such as carboxyl group-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, methylol group-modified polyvinyl alcohol, and amino group-modified polyvinyl alcohol.
  • modified polyvinyl alcohols such as carboxyl group-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, methylol group-modified polyvinyl alcohol, and amino group-modified polyvinyl alcohol.
  • An example of a commercially available polyvinyl alcohol is "KL-318," an anionic group-containing polyvinyl alcohol manufactured by Kuraray Co., Ltd.
  • the (meth)acrylic resin a resin containing a (meth)acrylic polymer or a crosslinked product thereof can be used as the polymer (P1).
  • examples of the (meth)acrylic polymer include a homopolymer of a (meth)acrylic monomer, a copolymer of two or more types of (meth)acrylic monomers, and a copolymer of one or more types of (meth)acrylic monomers with other monomers.
  • examples of the (meth)acrylic monomer include acrylic acid, acrylic acid esters such as alkyl acrylates, acrylamide, acrylonitrile, methacrylic acid, methacrylic acid esters such as alkyl methacrylates, methacrylamide, and methacrylonitrile.
  • the polymer (P1) a polymer having a (meth)acrylic acid ester unit is preferable, and a homopolymer or copolymer of an acrylic monomer selected from the group consisting of an acrylic acid ester and a methacrylic acid ester is more preferable.
  • Particularly preferable examples include a homopolymer or copolymer of an acrylic monomer selected from the group consisting of an acrylic acid ester and a methacrylic acid ester having an alkyl group having 1 to 6 carbon atoms.
  • the acrylic polymer is preferably a copolymer of a copolymerization component having a polar group such as a hydroxyl group or a carboxyl group in combination with the acrylic monomer so as to be capable of reacting (crosslinking reaction) with the functional group of the crosslinking agent.
  • a copolymerization component having a polar group such as a hydroxyl group or a carboxyl group in combination with the acrylic monomer so as to be capable of reacting (crosslinking reaction) with the functional group of the crosslinking agent.
  • a polar group such as a hydroxyl group or a carboxyl group
  • the weight proportion of the (meth)acrylic acid ester units in the polymer (P1) is preferably 1% by weight or more, more preferably 5% by weight or more, and even more preferably 10% by weight or more, and is usually 100% by weight or less, assuming that the total of the monomer units contained in the polymer (P1) is 100% by weight.
  • the polymer (P1) contained in the easy-adhesion layer material is preferably a copolymer of an alkyl ester of methacrylic acid and an alkyl ester of acrylic acid.
  • the number of carbon atoms in the alkyl group constituting the alkyl ester is preferably 1 to 6, and particularly preferably 1 to 4.
  • the polymer (P1) is a copolymer of methyl methacrylate and butyl acrylate.
  • the polymer (P1) constituting the easy-adhesion layer material may be one type, or two or more types. Therefore, the easy-adhesion layer material may be a composite resin containing two or more types of the above-mentioned polyurethane, polyolefin, polyester, epoxy polymer, and (meth)acrylic polymer in combination. For example, it may be a resin containing a combination of polyurethane and acid-modified polyolefin, or a resin containing a combination of polyester and acrylic polymer.
  • the proportion of polymer (P1) in the solid content (total amount of components other than the solvent) of the easy-adhesion layer material is preferably 50% by weight to 99% by weight, more preferably 70% by weight to 99% by weight, and particularly preferably 90% by weight to 97% by weight.
  • the proportion of polymer (P1) is within the above range, the resulting easy-adhesion layer can exhibit the desired adhesion.
  • the easy-adhesion layer which is a cured product of the easy-adhesion layer material, can be a layer containing a polymer having a crosslinked structure.
  • the crosslinking agent (1) a compound having two or more functional groups in the molecule capable of reacting with a functional group such as a polar group contained in the polymer to form a bond, a polymer crosslinking agent in which a monomer composition containing the compound is polymerized to form a polymer having a functional group capable of forming a bond, or a mixture thereof can be used.
  • crosslinking agent compound examples include an epoxy compound, a carbodiimide compound, an oxazoline compound, an isocyanate compound, and the like.
  • the crosslinking agent compound may be used alone or in combination of two or more types in any ratio.
  • epoxy compound a multifunctional epoxy compound having two or more epoxy groups in the molecule can be used. This allows the crosslinking reaction to proceed, effectively improving the mechanical strength of the resin layer.
  • epoxy compounds those that are soluble in water or can be dispersed in water to form an emulsion are preferred from the viewpoint of ease of use.
  • examples of epoxy compounds include diepoxy compounds obtained by etherifying 1 mole of glycols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexylene glycol, and neopentyl glycol with 2 moles of epichlorohydrin; polyepoxy compounds obtained by etherifying 1 mole of polyhydric alcohols such as glycerin, polyglycerin, trimethylolpropane, pentaerythritol, and sorbitol with 2 moles or more of epichlorohydrin; diepoxy compounds obtained by esterifying 1 mole of dicarboxylic acid such as phthalic acid, terephthalic acid, oxalic acid, and adipic acid with 2
  • preferred epoxy compounds include 1,4-bis(2',3'-epoxypropyloxy)butane, 1,3,5-triglycidyl isocyanurate, 1,3-diglycidyl-5-( ⁇ -acetoxy- ⁇ -oxypropyl)isocyanurate, sorbitol polyglycidyl ethers, polyglycerol polyglycidyl ethers, pentaerythritol polyglycidyl ethers, diglycerol polyglycidyl ethers, glycerol polyglycidyl ethers, and trimethylolpropane polyglycidyl ethers.
  • Specific examples of commercially available products include the "Denacol (Denacol EX-521, EX-614B, etc.)" series manufactured by Nagase ChemteX Corporation.
  • an addition-polymerizable oxazoline compound can be used as the oxazoline compound.
  • Specific examples include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline. These compounds may be used alone or in combination of two or more at any ratio. Among these, 2-isopropenyl-2-oxazoline is preferred because it is easily available industrially.
  • a crosslinking agent (1-o) that is a polymer of an addition-polymerizable oxazoline compound and an arbitrary unsaturated monomer is particularly preferred.
  • the arbitrary unsaturated monomer other than the oxazoline compound that constitutes the crosslinking agent (1-o) any monomer that is copolymerizable with the addition-polymerizable oxazoline and does not react with the oxazoline group can be used.
  • Such an arbitrary unsaturated monomer can be arbitrarily selected from the monomers described above.
  • a specific example of a preferred unsaturated monomer is a methacrylic acid ester such as methyl methacrylate.
  • the crosslinking agent (1-o) a copolymer of 2-isopropenyl-2-oxazoline and a methacrylic acid ester is particularly preferred in terms of achieving the desired effects such as good adhesion.
  • the amount of addition-polymerizable oxazoline used in the production of the crosslinking agent (1-o) is preferably 5 parts by weight or more per 100 parts by weight of the total monomer components used in the production of the oxazoline compound.
  • Crossing agents (1-o) that are commercially available can be used.
  • water-soluble crosslinking agents (1-o) include Epocross WS-500 and WS-700 manufactured by Nippon Shokubai Co., Ltd.
  • emulsion-type crosslinking agents (1-o) include Epocross K-2010, K-2020, and K-2030 manufactured by Nippon Shokubai Co., Ltd.
  • Crosslinking agent (1-o) and other crosslinking agents (1) may be used alone or in combination of two or more in any ratio.
  • the ratio of the crosslinking agent (1) to the polymer (P1) in the easy-adhesion layer can be adjusted appropriately to a range in which the desired adhesion and other effects are achieved.
  • the ratio of the crosslinking agent (1) to a total of 100 parts by weight of the polymer (P1) and the crosslinking agent (1) is preferably 1 part by weight or more, more preferably 3 parts by weight or more, while it is preferably 30 parts by weight or less, more preferably 20 parts by weight or less.
  • the easy-adhesion layer material may contain a solvent. By containing a solvent, the easy-adhesion layer material can be made into a liquid composition, and the operation of forming the easy-adhesion layer, such as coating, can be facilitated.
  • a solvent water, an organic solvent, or a mixture thereof can be appropriately selected.
  • organic solvents examples include methyl acetate, ethyl acetate, acetone, methyl ethyl ketone, 3-methyl-2-butanone, methyl isopropyl ketone, methyl isobutyl ketone, tetrahydrofuran, cyclopentyl methyl ether, acetylacetone, cyclohexanone, 2-methylcyclohexanone, 1,3-dioxolane, 1,4-dioxane, 2-pentanone, and N,N-dimethylformamide.
  • the solvent may be used alone or in combination of two or more kinds in any ratio. Water can be preferably used as the solvent because of its good volatility and high ability to dissolve other components.
  • the proportion of the solvent contained in the easy-adhesion layer material can be adjusted as appropriate to obtain physical properties suitable for the operation of forming the easy-adhesion layer, such as coating. Specifically, the proportion can be adjusted so that the solids concentration (proportion of components other than the solvent, including organic particles (NP)) is preferably 1% by weight to 20% by weight, more preferably 2% by weight to 10% by weight.
  • the solids concentration proportion of components other than the solvent, including organic particles (NP)
  • the easy-adhesion layer material may further include any optional components, such as a curing accelerator, a curing assistant, particles other than organic particles (NPs), a heat stabilizer, a weather stabilizer, a leveling agent, a surfactant, an antioxidant, an antistatic agent, a slip agent, an antiblocking agent, an antifogging agent, a lubricant, a dye, a pigment, a natural oil, a synthetic oil, and a wax.
  • a curing accelerator such as a curing assistant, particles other than organic particles (NPs), a heat stabilizer, a weather stabilizer, a leveling agent, a surfactant, an antioxidant, an antistatic agent, a slip agent, an antiblocking agent, an antifogging agent, a lubricant, a dye, a pigment, a natural oil, a synthetic oil, and a wax.
  • NPs organic particles
  • the anchor layer is preferably a cured product of the anchor layer material.
  • the anchor layer is provided to enhance adhesion between the base film and the top layer.
  • the anchor layer material includes a polymer (P2) and a crosslinking agent (2).
  • Anchor layer material polymer (P2)
  • various resins including polymers can be used.
  • the resin include the same examples as those of the resin that can be contained in the easy-adhesion layer material.
  • the polymer (P2) contained in the anchor layer material is preferably a polymer having a (meth)acrylic acid ester unit.
  • the polymer (P2) is preferably a polymer having a (meth)acrylic acid ester unit, and more preferably a homopolymer or copolymer of an acrylic monomer selected from the group consisting of acrylic acid esters and methacrylic acid esters.
  • Particularly preferred examples include homopolymers and copolymers of acrylic monomers selected from the group consisting of acrylic acid esters and methacrylic acid esters having an alkyl group having 1 to 6 carbon atoms.
  • the acrylic polymer is preferably a copolymer of a copolymerization component having a polar group such as a hydroxyl group or a carboxyl group in combination with the acrylic monomer so as to be capable of reacting (crosslinking reaction) with the functional group of the crosslinking agent.
  • the weight proportion of the (meth)acrylic acid ester units in the polymer (P2) may be in the same range as the weight proportion of the (meth)acrylic acid ester units in the polymer (P1) when the polymer (P1) has (meth)acrylic acid ester units.
  • the polymer (P2) contained in the anchor layer material is preferably a copolymer of an alkyl ester of methacrylic acid and an alkyl ester of acrylic acid.
  • the number of carbon atoms in the alkyl group constituting the alkyl ester is preferably 1 to 6, and particularly preferably 1 to 4.
  • the polymer (P2) is a copolymer of methyl methacrylate and butyl acrylate.
  • the proportion of polymer (P2) in the solid content (total amount of components other than the solvent) of the anchor layer material is preferably 50% by weight to 99% by weight, more preferably 70% by weight to 99% by weight, and particularly preferably 90% by weight to 99% by weight.
  • the proportion of polymer (P2) is within the above range, the resulting anchor layer can exhibit the desired adhesion.
  • the anchor layer which is a cured product of the anchor layer material, can be a layer containing a polymer having a crosslinked structure.
  • the crosslinking agent (2) include the same examples as the examples of the crosslinking agent (1) that can be included in the easy-adhesion layer material.
  • the ratio of the crosslinking agent (2) to the polymer (P2) in the anchor layer can be adjusted appropriately to a range in which the desired adhesion and other effects are achieved. Specifically, it can be in the same range as the ratio of the crosslinking agent (1) to the polymer (P1) in the easy-adhesion layer.
  • the anchor layer material may contain a solvent.
  • a solvent By containing a solvent, the anchor layer material can be made into a liquid composition, and the operation of forming the anchor layer, such as coating, can be facilitated.
  • the solvent include the same examples as those of the solvent that the easy-adhesion layer material may contain.
  • the solvent may be used alone or in combination of two or more types in any ratio. Water is preferably used as the solvent because of its good volatility and high ability to dissolve other components.
  • the proportion of the solvent in the anchor layer material can be adjusted as appropriate to obtain properties suitable for the operation of forming the anchor layer, such as coating. Specifically, the proportion can be adjusted so that the solids concentration (proportion of components other than the solvent) is preferably 1% by weight to 20% by weight, and more preferably 2% by weight to 15% by weight.
  • the anchor layer material may further contain optional components.
  • optional components include the same examples as the optional components that may be contained in the easy-adhesion layer material.
  • One type of optional component may be used alone, or two or more types may be used in combination in any ratio.
  • the polymer (P2) that can be contained in the anchor layer material and the polymer (P1) that can be contained in the easy-adhesion layer material preferably have a common monomer unit. It is more preferable that the anchor layer material contains a polymer containing a (meth)acrylic acid ester unit as the polymer (P2), and the easy-adhesion layer material contains a polymer containing a (meth)acrylic acid ester unit as the polymer (P1), and that the polymer (P1) and the polymer (P2) have a common (meth)acrylic acid ester unit.
  • Polymer (P1) and Polymer (P2) having common (meth)acrylic acid ester units means that both Polymer (P1) and Polymer (P2) have common acrylic acid ester units and/or common methacrylic acid ester units.
  • common (meth)acrylic acid ester units it is preferable for the "common (meth)acrylic acid ester units” to have methacrylic acid ester units, and it is even more preferable for them to have methyl methacrylate units.
  • both polymer (P1) and polymer (P2) are preferably polymers having methyl methacrylate units and butyl acrylate units, and more preferably copolymers of methyl methacrylate and butyl acrylate.
  • crosslinking agent (2) that can be contained in the anchor layer material and the crosslinking agent (1) that can be contained in the easy-adhesive material are preferably the same crosslinking agent. More specifically, it is more preferable that both the crosslinking agent (1) and the crosslinking agent (2) are copolymers of methyl methacrylate and 2-isopropenyl oxazoline.
  • the top layer is preferably a cured product of the top layer material.
  • the top layer is preferably a coated layer formed by coating the top layer material.
  • the top layer material is preferably a material containing a polymer (P3).
  • top Layer Material Polymer (P3))
  • P3 polymer having positive intrinsic birefringence
  • a polymer having negative intrinsic birefringence is preferred.
  • polymers having negative intrinsic birefringence include homopolymers of styrene or styrene derivatives, and styrene-based polymers including copolymers of styrene or styrene derivatives with any monomer (e.g., polystyrene, poly(2-vinylnaphthalene)); polyacrylonitrile polymers; polymethyl methacrylate polymers; multicomponent copolymers thereof; and cellulose compounds such as cellulose ester polymers. These polymers may be used alone or in combination of two or more types in any ratio.
  • polymers having styrene-based monomer units or cellulose ester polymers are preferred, and polymers having styrene-based monomer units are more preferred.
  • styrene-based monomer refers to styrene monomers, styrene derivative monomers, and combinations thereof.
  • optional monomers that copolymerize with styrene or styrene derivatives include acrylonitrile, maleic anhydride, methyl methacrylate, and butadiene. These polymers may be used alone or in combination of two or more in any ratio.
  • styrene derivatives include derivatives having substituents at one or more substitution positions selected from the benzene ring, ⁇ -position, or ⁇ -position of styrene, and hydrogenated versions of these.
  • substituents include halogen atoms, alkyl groups, alkenyl groups, aromatic groups, alkoxy groups, and alkoxycarbonyl groups. When the substituents are carbon-containing groups, the number of carbon atoms per substituent may be 1 to 6.
  • Styrene derivatives also include derivatives having a structure in which substituents at multiple substitution positions on the benzene ring are bonded to form a ring (e.g., vinylnaphthalene).
  • styrene monomers include styrene, halogenated styrene, halogenated alkylstyrene, alkylstyrene, alkenylstyrene, alkoxystyrene, alkoxycarbonylstyrene, and hydrogenated versions of these.
  • halogenated styrenes examples include chlorostyrene, bromostyrene, and fluorostyrene.
  • An example of a halogenated alkylstyrene is chloromethylstyrene.
  • alkylstyrenes examples include methylstyrene, ethylstyrene, isopropylstyrene, t-butylstyrene, and 2,4-dimethylstyrene.
  • alkenylstyrenes examples include vinylstyrene.
  • alkoxystyrenes examples include methoxystyrene and ethoxystyrene.
  • alkoxycarbonylstyrenes examples include vinyl benzoate.
  • styrene monomers include phenylstyrene and vinylnaphthalene.
  • a cellulose ester polymer with negative intrinsic birefringence is a cellulose ester polymer in which an appropriate aryl group has been introduced into cellulose by acylation.
  • a particularly preferred example of the polymer (P3) constituting the top layer material is a copolymer of styrene or a styrene derivative and maleic anhydride.
  • a copolymer of styrene or a styrene derivative and maleic anhydride is particularly preferred from the viewpoint of high heat resistance.
  • the amount of maleic anhydride units is preferably 5 parts by weight or more, more preferably 10 parts by weight or more, particularly preferably 15 parts by weight or more, and preferably 30 parts by weight or less, more preferably 28 parts by weight or less, particularly preferably 26 parts by weight or less, per 100 parts by weight of the styrene-based polymer.
  • a maleic anhydride unit refers to a structural unit having a structure formed by polymerizing maleic anhydride.
  • the proportion of polymer (P3) in the solid content (total amount of components other than the solvent) of the top layer material is preferably 50% by weight to 100% by weight, more preferably 70% by weight to 100% by weight, and particularly preferably 90% by weight to 100% by weight.
  • the top layer can exhibit appropriate optical properties.
  • the top layer material may contain a solvent.
  • the top layer material By containing a solvent, the top layer material can be a liquid composition, and the operation of forming the top layer, such as coating, can be facilitated.
  • the solvent include the same examples as those of the solvent that can be contained in the easy-adhesion layer material.
  • the solvent may be used alone or in combination of two or more types in any ratio. Ketones such as methyl ethyl ketone, methyl isobutyl ketone, or mixtures thereof can be preferably used as the solvent because of their good volatility and high ability to dissolve other components.
  • the proportion of solvent in the top layer material can be adjusted as appropriate to obtain physical properties suitable for the operation of forming the top layer, such as coating. Specifically, the proportion can be adjusted so that the solids concentration (proportion of components other than the solvent) is preferably 5% to 25% by weight, more preferably 10% to 20% by weight.
  • the top layer material may further contain an optional additive (t).
  • the additive (t) is a separate component that is usually contained in a smaller weight ratio than the polymer (P3), which is the main component.
  • the additive (t) is preferably a substance that is compatible with the polymer (P3). Specifically, when the additive (t) is contained, it is preferable to appropriately select the type of additive (t) so as to satisfy the haze requirements of the resulting multilayer film.
  • Additive (t) can perform functions such as adjusting the degree of optical anisotropy of the top layer to a desired range.
  • Additive (t) can perform functions such as adjusting the degree of optical anisotropy of the top layer to a desired range.
  • the thickness of the top layer suitable for obtaining the desired optical properties of the final stretched multilayer film is excessively thin, the molding precision decreases and the surface unevenness of the top layer may become large.
  • additive (t) having positive intrinsic birefringence to the top layer material in combination with polymer (P3) having negative intrinsic birefringence, it is possible to improve the surface unevenness of the top layer.
  • additives (t) include polymers such as (meth)acrylic polymers, styrene polymers, (meth)acrylic-styrene copolymers, polyesters, polycarbonates, and olefin polymers. These polymers may be used alone or in combination of two or more in any ratio, or may be copolymers of each resin. In particular, (meth)acrylic polymers, styrene polymers, and (meth)acrylic-styrene copolymers are preferred because they are highly likely to be compatible with the polymer (P3) having a negative intrinsic birefringence value.
  • P3 polymer having a negative intrinsic birefringence value
  • a particularly preferred example of additive (t) from the viewpoint of compatibility with the preferred polymer (P3), and of satisfactorily satisfying the above-mentioned additive properties and other requirements of the present invention is a copolymer containing (meth)acrylic acid ester units and styrene-based monomer units (for example, product name "TX-100S", manufactured by Denka Co., Ltd., a copolymer of methyl methacrylate and styrene).
  • the ratio of additive (t) to polymer (P3) can be adjusted appropriately to a range in which the desired optical effects and other effects are achieved, such as adjusting the degree of optical anisotropy of the top layer to a desired range.
  • the ratio of additive (t) to 100 parts by weight of polymer (P3) is preferably more than 0 parts by weight, preferably 5 parts by weight or more, and preferably 75 parts by weight or less, more preferably 70 parts by weight or less, even more preferably 50 parts by weight or less, and even more preferably 25 parts by weight or less.
  • top layer material other ingredients
  • the top layer material may further include optional components.
  • optional components include the same optional components as those included in the thermoplastic resin (s).
  • the optional components may be used alone or in combination of two or more in any ratio.
  • the easy-adhesion layer is usually a cured product of the easy-adhesion layer material described above
  • the anchor layer is usually a cured product of the anchor layer material described above
  • the top layer is usually a cured product of the top layer material described above.
  • the method of forming the easy-adhesion layer, anchor layer, and top layer from the easy-adhesion layer material, anchor layer material, and top layer material, respectively, is not particularly limited, and any known method can be appropriately selected and used.
  • the easy-adhesion layer can be formed by applying the easy-adhesion layer material to the surface of the base film to form a coating film of the easy-adhesion layer material and drying the coating film.
  • the anchor layer can be formed by applying the anchor layer material to the surface of the easy-adhesion layer to form a coating film of the anchor layer material and drying the coating film.
  • the top layer can be formed by applying the top layer material to the surface of the anchor layer to form a coating film of the top layer material and drying the coating film.
  • the easy-adhesion layer material, anchor layer material, and top layer material may each contain a solvent. When forming the easy-adhesion layer, anchor layer, and top layer, these solvents may volatilize and disappear in part or in whole from the layers.
  • the easy-adhesion layer material and anchor layer material may contain reactive materials such as crosslinking agents. When forming the easy-adhesion layer and anchor layer, these reactive materials may react and become elements that form part of the structure of polymer molecules, such as crosslinking.
  • the multilayer film of this embodiment can be manufactured by any method.
  • the multilayer film can be manufactured by a manufacturing method including the following steps (1), (2-1), (2-2), (3), (4), (5-1), (5-2), (6-1), (6-2), and (7) in this order.
  • the manufacturing method for the multilayer film may include any steps in addition to the steps below.
  • Step (1) A step of preparing a long base film.
  • Step (2-1) A step of applying a liquid adhesive layer material onto the base film to form a coating film of the adhesive layer material.
  • Step (2-2) A step of drying the coating film of the easy-adhesion layer material to form an easy-adhesion layer and obtain a multilayer body (I) having the base film and the easy-adhesion layer.
  • Step (3) A step of stretching the multi-layered product (I) to obtain a multi-layered product (II).
  • Step (5-1) A step of unwinding the wound multilayer material (II) and applying a liquid anchor layer material onto the easy-adhesion layer of the multilayer material (II) to form a coating film of the anchor layer material.
  • Step (5-2) A step of drying the coating film of the anchor layer material to form an anchor layer, thereby obtaining a multilayer body (III) having the base film, the easy-adhesion layer, and the anchor layer in this order.
  • Step (6-1) A step of applying a liquid top layer material onto the anchor layer of the multilayer structure (III) to form a coating film of the top layer material.
  • a base film is prepared.
  • the base film is usually formed by molding a thermoplastic resin (s).
  • the base film is usually formed as a film. From the viewpoint of efficient production of the multilayer film, it is preferable that the base film is formed as a long film.
  • the base film is cut along its longitudinal direction. The substrate can then be transported onto a transport line, and subsequent steps can be carried out continuously downstream of the transport line.
  • the method for forming the substrate film is not particularly limited.
  • methods for forming the substrate film include melt molding and solution casting. More specific examples of melt molding include extrusion molding, press molding, inflation molding, injection molding, blow molding, and stretch molding. Among these methods, from the viewpoint of obtaining a substrate film with excellent mechanical strength and surface precision, extrusion molding, inflation molding, and press molding are preferred, and among these, extrusion molding is particularly preferred from the viewpoint of being able to efficiently and easily produce a substrate film.
  • step (2-1) In the step (2-1), a liquid adhesive layer material is applied onto the base film to form a coating film of the adhesive layer material.
  • liquid adhesive layer materials examples include curtain coating, extrusion coating, roll coating, spin coating, dip coating, bar coating, spray coating, slide coating, print coating, gravure coating, die coating, and gap coating.
  • the coating thickness of the easy-adhesion layer material can be adjusted so that the easy-adhesion layer has the desired thickness T1 in the multilayer film produced.
  • step (2-2) the coating film of the easy-adhesion layer material is dried to form an easy-adhesion layer, and a multilayer body (I) including the base film and the easy-adhesion layer is obtained.
  • the coating film of the easy-adhesion layer material can be dried by a drying method such as natural drying, heat drying, reduced pressure drying, reduced pressure heat drying, etc.
  • a treatment for promoting crosslinking may be optionally performed on the coating film of the easy-adhesion layer material.
  • Such a treatment can promote the crosslinking reaction of the crosslinking agent (1) and improve the mechanical strength and solvent resistance of the easy-adhesion layer.
  • crosslinking treatments include heating treatment and irradiation with active energy rays such as ultraviolet rays.
  • Step (3) In the step (3), the multi-layered product (I) is stretched to obtain a multi-layered product (II).
  • the angle that the stretching direction makes with the width direction of the base film is preferably 35° or more, more preferably 37° or more, even more preferably 40° or more, particularly preferably 42° or more, and is preferably 55° or less, more preferably 53° or less, even more preferably 50° or less, particularly preferably 48° or less.
  • the stretching ratio in step (3) is preferably 1.1 times or more, more preferably 1.2 times or more, and is preferably 2.5 times or less, more preferably 2.0 times or less.
  • the stretching ratio is equal to or greater than the lower limit of the range, the refractive index in the stretching direction can be increased.
  • the stretching ratio is equal to or less than the upper limit of the range, the direction of the slow axis of the stretched substrate film can be easily controlled.
  • the stretching temperature in step (3) is preferably TgA or higher, more preferably (TgA+2)°C or higher, particularly preferably (TgA+5)°C or higher, and is preferably (TgA+40)°C or lower, more preferably (TgA+35)°C or lower, particularly preferably (TgA+30)°C or lower.
  • TgA represents the glass transition temperature of the thermoplastic resin (s).
  • the direction of the slow axis of the laminate (II) is preferably in an oblique direction that is neither parallel nor perpendicular to the width direction of the laminate (II).
  • the orientation angle of the laminate (II) is preferably 25° or more, more preferably 30° or more, even more preferably 35° or more, and is preferably less than 55°, more preferably less than 50°, even more preferably less than 48°.
  • the optical properties such as retardation of the multilayer material (II) can be set according to the optical properties desired to be expressed in the multilayer film.
  • the in-plane retardation Re of the multilayer material (II) is preferably 180 nm or more, more preferably 190 nm or more, particularly preferably 200 nm or more, and is preferably 250 nm or less, more preferably 240 nm or less, particularly preferably 230 nm or less.
  • the thickness of the multilayer material (II) can be set arbitrarily within the range in which the desired multilayer film can be obtained.
  • the specific thickness is preferably 30 ⁇ m or more, more preferably 35 ⁇ m or more, particularly preferably 40 ⁇ m or more, and is preferably 80 ⁇ m or less, more preferably 70 ⁇ m or less, particularly preferably 60 ⁇ m or less.
  • step (4) the laminate (II) is wound up.
  • a base film and organic particles (NP) provided directly on one surface of the base film are A multi-layered product (II) having an easy-adhesion layer which is a cured product of an easy-adhesion layer material containing the organic particles (NP) can be obtained. Therefore, even when the multi-layered material (II) is wound up, the wound multi-layered material (II) is not scratched due to friction between the layers of the multi-layered material (II). Furthermore, in the step (5-1) described below, the multi-layered product (II) can be smoothly unwound.
  • the coefficient of dynamic friction between the base film and the easy-adhesion layer of the multilayered product (II) is preferably 0.8 or less, more preferably 0.75 or less, since this can more effectively reduce defects.
  • the coefficient of dynamic friction between the base film and the easy-adhesion layer can be measured by the following method.
  • step (5-1) the wound multilayered product (II) is unwound, and a liquid anchor layer material is applied onto the adhesive layer of the multilayered product (II), and the anchor layer A coating film of the material is formed.
  • the coating method of the liquid anchor layer material include the same examples as those given as examples of the coating method of the liquid easy-adhesion layer material in step (2-1). .
  • the coating thickness of the anchor layer material can be adjusted so that the anchor layer has the desired thickness T2 in the multilayer film produced.
  • step (5-2) the coating film of the anchor layer material is dried to form an anchor layer, and a multilayer body (III) having the base film, the easy-adhesion layer, and the anchor layer in this order is obtained. obtain.
  • the method for drying the coating film of the anchor layer material include the same methods as those given as examples of the method for drying the coating film of the easy-adhesion layer material in the step (2-2).
  • step (6-1) a liquid top layer material is applied onto the anchor layer of the multi-layered product (III) to form a coating film of the top layer material.
  • Examples of the method include the same methods as those given as examples of the coating method of the liquid easy-adhesion layer material in the step (2-1).
  • the coating thickness of the top layer material can be adjusted so that the top layer has the desired thickness in the resulting multilayer film.
  • step (6-2) the coating film of the top layer material is dried to form a top layer, and a multilayer structure having the base film, the easy-adhesion layer, the anchor layer, and the top layer in this order is obtained.
  • step (IV) is obtained.
  • the method for drying the coating film of the top layer material include the same methods as those given as examples of the method for drying the coating film of the easy-adhesion layer material in step (2-2), and preferably, drying the coating film using an oven. The heat drying method used was
  • step (7) the multilayer product (IV) is stretched to obtain a multilayer film.
  • the stretching of the laminate (IV) in the step (7) is usually carried out in an oven.
  • the stretching direction in step (7) can be set according to the optical properties to be expressed in the multilayer film.
  • the stretching direction in step (7) is the same as that of the multilayer (IV). It is preferable that the stretching direction is substantially parallel to the longitudinal direction.
  • the angle between the stretching direction and the width direction of the laminate (IV) is preferably 85° or more, more preferably 87° or more. It is more preferably 89° or more, and is preferably 95° or less, more preferably 93° or less, further preferably 91° or less, and particularly preferably 90°.
  • the stretching in step (7) may be performed as free uniaxial stretching.
  • Free uniaxial stretching refers to stretching in a certain direction in which no restraining force is applied in any direction other than the direction of stretching.
  • free uniaxial stretching in a direction substantially parallel to the longitudinal direction of the multi-layered product (IV) can be stretching in the longitudinal direction without restraining the ends of the multi-layered product (IV) in the width direction.
  • the stretching ratio in step (7) is preferably 1.1 times or more, more preferably 1.15 times or more, particularly preferably 1.2 times or more, and is preferably 2.0 times or less, more preferably 1.8 times or less, particularly preferably 1.6 times or less.
  • the stretching ratio in step (7) is within the above range, a multilayer film having the desired optical properties can be easily obtained.
  • the film of the present embodiment can be a film with good adhesion.
  • adhesion is an index of resistance to peeling between the base film and the top layer.
  • the adhesion can be measured by a cross-cut test defined in JIS K5600-5-6 (1999). Specifically, the top layer, anchor layer, and easy-adhesion layer of the multilayer film sample are cut at 1 mm intervals in a range of 5 mm x 5 mm to create 25 squares with a side of 1 mm.
  • the adhesion can be evaluated by attaching cellophane tape to the surface of the top layer side of the sample, peeling the cellophane tape, and measuring the number of squares that remain attached to the base film of the multilayer film without peeling. The more squares that remain, the higher the adhesion. In this embodiment, this test can produce an adhesion of 20/25 or more.
  • the good adhesion of the multilayer film can improve the durability of a display device incorporating the multilayer film. In addition, it can facilitate rework during the manufacturing process of the display device. For example, if the multilayer film is attached to a panel containing a display element (such as a liquid crystal cell of a liquid crystal display device) and then it is discovered that there is a defect in the attachment, and the multilayer film is peeled off to reuse the panel, it can reduce the occurrence of defects such as only part of the layers of the multilayer film remaining on the panel.
  • a display element such as a liquid crystal cell of a liquid crystal display device
  • the multilayer film preferably has high transparency. Therefore, it is preferable that the multilayer film has high total light transmittance.
  • the specific total light transmittance of the multilayer film is preferably 80% or more, more preferably 85% or more, and particularly preferably 88% or more.
  • the light transmittance can be measured in the wavelength range of 400 nm to 700 nm using a spectrophotometer in accordance with JIS K0115.
  • the overall thickness of the multilayer film is preferably 30 ⁇ m or more, more preferably 35 ⁇ m or more, and particularly preferably 40 ⁇ m or more, and is preferably 100 ⁇ m or less, more preferably 90 ⁇ m or less, and particularly preferably 80 ⁇ m or less.
  • the multilayer film preferably has a long shape.
  • the width of the long multilayer film is preferably 1300 mm or more, more preferably 1400 mm or more, particularly preferably 1500 mm or more, and is preferably 2000 mm or less, more preferably 1800 mm or less.
  • the multilayer film as a broadband wavelength film may be laminated with a linear polarizer and used to manufacture a circular polarizing plate. Since the above-mentioned multilayer film has small variation in in-plane retardation, a circular polarizing plate equipped with the multilayer film can suppress variation in the polarization state of the circularly polarized light that passes through the circular polarizing plate. Therefore, this circular polarizing plate can be used as a reflection-suppressing film that suppresses light reflection with high uniformity.
  • the weight average particle size of the particles was measured by dynamic light scattering using "Nanotrac UPA-EX150” manufactured by Microtrac Corporation, USA.
  • In-plane retardation Re The in-plane retardation Re of the sample film was measured by a phase difference meter (Axometrics'"AxoScan").
  • the adhesion was evaluated by a cross-cut test according to JIS K5600-5-6 (1999).
  • the top layer, anchor layer, and easy-adhesion layer of the multilayer film sample were cut at 1 mm intervals in a range of 5 mm x 5 mm to create 25 squares with a side of 1 mm.
  • Cellophane tape was attached to the surface of the top layer side of the sample, and the cellophane tape was peeled off.
  • the number of squares remaining on the base film of the multilayer film without peeling off was counted, and was also evaluated according to the following evaluation criteria. Good: The number of remaining squares is between 20/25 and 25/25. Poor: 19/25 or less squares remaining.
  • the multilayer film was placed on a blackboard and the surface condition was visually observed under a fluorescent lamp.
  • the multilayer film was observed in an area of 1 m x 1 m, and foreign matter with a maximum diameter of 100 ⁇ m or more was counted as a defect.
  • Example 1 (1-1. Base Film) Pellet-shaped norbornene-based resin (manufactured by Zeon Corporation; glass transition temperature 126° C.) was dried for 5 hours at 100° C. The dried resin was fed to an extruder, passed through a polymer pipe and a polymer filter, and extruded from a T-die onto a casting drum in the form of a sheet, thereby carrying out extrusion molding. The molded resin was cooled to obtain a long substrate film (i) having a thickness of 70 ⁇ m.
  • the easy-adhesion layer material 1 obtained in (1-2) was applied to the corona-treated surface of the base film (i) to form a coating of the easy-adhesion layer material.
  • the application was performed using a roll coater under conditions such that the coating would have a thickness of 0.1 ⁇ m after drying.
  • the coating of the easy-adhesion layer material was heated at a temperature of 110°C for 60 seconds to form an easy-adhesion layer (i) on the base film (i).
  • the resulting multilayered product (I) was wound up on a roll and collected.
  • the laminate (I) was unwound from the roll.
  • the unwound multilayered product (I) was continuously supplied to a tenter stretching machine, and the multilayered product (I) was stretched by the tenter stretching machine.
  • the stretching direction was a direction forming an angle of 45° with respect to the width direction of the multilayered product (I).
  • the stretching temperature was 135°C, and the stretching ratio was 1.5 times.
  • the substrate film (ii) is a layer obtained as a result of stretching the substrate film (i), and the easy adhesion layer (ii) is a layer obtained as a result of stretching the easy adhesion layer (i).
  • the orientation angle of the substrate film (ii) in the multilayered product (II) with respect to the film width direction was 45°, and the in-plane retardation Re of the multilayered product (II) was 215 nm.
  • the thickness of the base film (ii) in the multilayered product (II) was 47 ⁇ m, and the thickness of the easy-adhesion layer (ii) was 0.085 ⁇ m.
  • the obtained multilayered product (II) was wound around a roll and collected.
  • the laminate (II) obtained in (1-4) was unwound from the roll.
  • the anchor layer material 1 obtained in (1-5) was applied to the surface of the base film (ii) of the unwound multilayered product (II) (i.e., the surface of the easy-adhesion layer (ii)) to form a coating film of the anchor layer material 1.
  • the coating was performed using a reverse gravure that rotates in the opposite direction to the film transport direction.
  • Laminated material (IV) A styrene-maleic anhydride copolymer resin ("Dylark D332" manufactured by Nova Chemical Co.) was prepared as a resin having a negative intrinsic birefringence. A mixed solvent of methyl ethyl ketone and methyl isobutyl ketone (weight ratio 8:2) was also prepared. 100 parts of styrene-maleic anhydride copolymer resin was dissolved in a mixed solvent, and 5 parts of triphenyl phosphate was further added as a plasticizer to obtain a liquid top layer material 1 having a solid content concentration of 15% by weight.
  • Top layer material 1 was applied by die coating to the surface of the resulting anchor layer (i) side to form a coating of top layer material 1.
  • the coating film of the top layer material 1 thus formed was dried at 120°C to form the top layer (i).
  • a long multilayered product (IV) having a layer structure of (top layer (i))/(anchor layer (i))/(easy adhesion layer (ii))/(base film (ii)) was obtained.
  • the thickness of the top layer (i) in the obtained multilayered product (IV) was 8 ⁇ m.
  • the obtained multilayered product (IV) was laminated with a masking film, and then wound up on a roll and collected.
  • the unwound multilayered material (IV) was continuously supplied to a longitudinal stretching machine, and the multilayered material (IV) was stretched by the longitudinal stretching machine.
  • the stretching was performed by free uniaxial stretching in the longitudinal direction of the multilayered material (IV).
  • the stretching temperature was 127°C, and the stretching ratio was 1.4 times.
  • the top layer (ii) is a layer obtained as a result of stretching the top layer (i)
  • the anchor layer (ii) is a layer obtained as a result of stretching the anchor layer (i)
  • the easy adhesion layer (iii) is a layer obtained as a result of stretching the easy adhesion layer (ii)
  • the base film (iii) is a layer obtained as a result of stretching the base film (ii).
  • the appearance of the resulting multilayer film was visually inspected, and the presence or absence of foreign matter in the film was evaluated.
  • the resulting multi-layer film was also evaluated for adhesion and found to have all squares in good adhesion (25/25).
  • Example 2 In (1-3), the coating conditions using a roll coater were adjusted to change the thickness of the coating of the adhesive layer material so that the thickness of the adhesive layer in the multilayer film was as shown in the table. Except for the above, the same procedure as in Example 1 was repeated to obtain a multilayer film and evaluate it.
  • Example 3 In (1-2), as the organic particles (NP), "Eposter MX100W” (weight average particle diameter 150 nm, solid content concentration 10%) manufactured by Nippon Shokubai Co., Ltd. was used instead of “Eposter MX200W” (weight average particle diameter 300 nm) manufactured by Nippon Shokubai Co., Ltd. Except for the above, the same procedure as in Example 1 was repeated to obtain a multilayer film and evaluate it.
  • *1 indicates that when unrolling the laminate (II) in (1-6), wrinkles occurred in the laminate (II), making it impossible to apply the anchor layer material, and therefore no laminate film could be obtained, and therefore evaluation was not possible.
  • the multilayer films according to Examples 1 to 3 are evaluated as having good adhesion.
  • the multilayer film according to Example 1 in which T1/T3 is 0.6 or less, has zero defects, and it is understood that the multilayer film can achieve high standards of adhesion and fewer defects.
  • the multilayer film manufacturing methods according to Examples 1 to 3 can provide multilayer films with excellent adhesion.
  • the desired multilayer film cannot be obtained in the method for producing a multilayer film according to Comparative Example 3, in which T3 is less than T1, i.e., T1/T3 is greater than 1. This is presumably because the slipperiness of the multilayer material (II) obtained in the middle is insufficient.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Laminated Bodies (AREA)

Abstract

L'invention concerne un film multicouche comprenant un film de base, une couche aisément adhérente disposée en contact direct avec une surface du film de base, une couche d'ancrage disposée en contact direct avec la surface de la couche aisément adhérente et une couche supérieure disposée en contact direct avec la surface de la couche d'ancrage. L'épaisseur totale (T1 + T2) de l'épaisseur T1 de la couche aisément adhérente et l'épaisseur T2 de la couche d'ancrage est de 150 nm ou plus. La couche aisément adhésive comprend des particules organiques (NP) ayant un diamètre moyen de particule T3 égal ou supérieur à l'épaisseur T1 de la couche aisément adhésive.
PCT/JP2023/042085 2022-12-07 2023-11-22 Film multicouche et procédé de fabrication d'un tel film multicouche WO2024122353A1 (fr)

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JP2022-195456 2022-12-07
JP2022195456 2022-12-07

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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007127823A (ja) * 2005-11-04 2007-05-24 Nippon Kayaku Co Ltd 光学フィルム及びその製造法
JP2015141674A (ja) * 2014-01-30 2015-08-03 日東電工株式会社 両面透明導電性フィルム及びその巻回体、並びにタッチパネル
JP2015214053A (ja) * 2014-05-09 2015-12-03 日東電工株式会社 積層体
JP2016216063A (ja) * 2015-05-15 2016-12-22 旭化成株式会社 プレススルーパック包装用蓋材及びプレススルーパック包装体
JP2017052203A (ja) * 2015-09-10 2017-03-16 株式会社東芝 熱転写リボン及びｉｄカード
WO2018030461A1 (fr) * 2016-08-10 2018-02-15 株式会社日本触媒 Film de résine stratifié
WO2018186241A1 (fr) * 2017-04-03 2018-10-11 富士フイルム株式会社 Corps multicouche, article anti-réfléchissant à surface incurvée tridimensionnelle, et procédé de fabrication d'un article anti-réfléchissant
JP2021109954A (ja) * 2020-01-15 2021-08-02 スリーエム イノベイティブ プロパティズ カンパニー 粘着シート及びその製造方法

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007127823A (ja) * 2005-11-04 2007-05-24 Nippon Kayaku Co Ltd 光学フィルム及びその製造法
JP2015141674A (ja) * 2014-01-30 2015-08-03 日東電工株式会社 両面透明導電性フィルム及びその巻回体、並びにタッチパネル
JP2015214053A (ja) * 2014-05-09 2015-12-03 日東電工株式会社 積層体
JP2016216063A (ja) * 2015-05-15 2016-12-22 旭化成株式会社 プレススルーパック包装用蓋材及びプレススルーパック包装体
JP2017052203A (ja) * 2015-09-10 2017-03-16 株式会社東芝 熱転写リボン及びｉｄカード
WO2018030461A1 (fr) * 2016-08-10 2018-02-15 株式会社日本触媒 Film de résine stratifié
WO2018186241A1 (fr) * 2017-04-03 2018-10-11 富士フイルム株式会社 Corps multicouche, article anti-réfléchissant à surface incurvée tridimensionnelle, et procédé de fabrication d'un article anti-réfléchissant
JP2021109954A (ja) * 2020-01-15 2021-08-02 スリーエム イノベイティブ プロパティズ カンパニー 粘着シート及びその製造方法

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