Resin film and manufacturing method of processed film

Abstract

To provide a resin film capable of suppressing an occurrence of a crack extending in a thickness direction when processing an outer shape.SOLUTION: The resin film has a Charpy tensile impact strength of 400 kJ / m2 or more.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for producing a resin film and a processed film. [Background technology]

[0002] Resin films are widely used in various industrial products, and are generally processed into shapes according to the intended use. For example, it has been proposed to process the outer shape of an acrylic resin film into a desired shape (see, for example, Patent Document 1). However, when the acrylic resin film described in Patent Document 1 is subjected to contour processing, cracks extending in the thickness direction may occur on the edge faces of the acrylic resin film. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-213401 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention has been made to solve the above-mentioned conventional problems, and its main object is to provide a resin film that can suppress the occurrence of cracks extending in the thickness direction during contour processing. [Means for solving the problem]

[0005] [1] The Charpy tensile impact strength of the resin film according to one embodiment of the present invention is 400 kJ / m 2 That's all. [2] The resin film described in [1] above may be made of a polycarbonate resin. [3] In a method for producing a processed film according to another aspect of the present invention, the resin film described in [1] or [2] above is subjected to contour processing. Effect of the Invention

[0006] According to an embodiment of the present invention, a resin film can be realized that can suppress the occurrence of cracks extending in the thickness direction during contour processing. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic cross-sectional view of a resin film according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic cross-sectional view of an embodiment of a polarizing plate including the resin film of FIG. [Diagram 3] FIG. 3 is a schematic cross-sectional view of another embodiment of a polarizing plate including the resin film of FIG. [Figure 4] FIG. 4 is a schematic plan view of a processed film produced from the resin film of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Representative embodiments of the present invention will be described below, but the present invention is not limited to these embodiments. In addition, in order to clarify the description, the width, thickness, shape, etc. of each part may be shown in a schematic manner compared to the embodiment, but these are merely examples and do not limit the interpretation of the present invention.

[0009] (Definition of terms and symbols) The definitions of terms and symbols used in this specification are as follows. (1) Refractive index (nx, ny, nz) "nx" is the refractive index in the direction in which the in-plane refractive index is maximum (i.e., the slow axis direction), "ny" is the refractive index in the direction perpendicular to the slow axis in the plane (i.e., the fast axis direction), and "nz" is the refractive index in the thickness direction. (2) In-plane phase difference (Re) "Re(λ)" is the in-plane retardation measured with light of wavelength λ nm at 23° C. For example, "Re(550)" is the in-plane retardation measured with light of wavelength 550 nm at 23° C. Re(λ) is calculated by the formula: Re(λ)=(nx-ny)×d, where d(nm) is the thickness of the layer (film). (3) Retardation in the thickness direction (Rth) "Rth(λ)" is the retardation in the thickness direction measured with light of wavelength λ nm at 23° C. For example, "Rth(550)" is the retardation in the thickness direction measured with light of wavelength 550 nm at 23° C. Rth(λ) is calculated by the formula: Rth(λ)=(nx-nz)×d, where d(nm) is the thickness of the layer (film).

[0010] A. Overall composition of resin film FIG. 1 is a schematic cross-sectional view of a resin film according to one embodiment of the present invention. As shown in FIG. 1, the Charpy tensile impact strength of the resin film 1 is 400 kJ / m 2 The Charpy tensile impact strength of the resin film is 400 kJ / m or more. 2 If this is the case, even if the resin film is subjected to the contour processing described below, the occurrence of cracks extending in the thickness direction (longitudinal direction) on the end faces of the resin film (processed film) after the contour processing can be suppressed.

[0011] The Charpy tensile impact strength of the resin film 1 is, for example, 700 kJ / m 2 Less than 600 kJ / m 2 Less than or equal to 500 kJ / m 2 The Charpy tensile impact strength is measured, for example, in accordance with JIS K 7160. If the Charpy tensile impact strength of the resin film is within this range, cracks extending in a direction perpendicular to the thickness direction (plane direction, horizontal direction) can be more stably suppressed at the end face of the resin film (processed film) after outer shape processing. In addition, if the Charpy tensile impact strength of the resin film is equal to or less than this upper limit, the resin film can be processed smoothly.

[0012] The shear fracture strength of the resin film 1 (the force required to cut and break a sample) is, for example, 1.0 N or more, preferably 2.5 N or more, more preferably 3.0 N or more, and even more preferably 3.5 N or more. On the other hand, the shear fracture strength of the resin film 1 is, for example, 7.0 N or less, preferably 6.0 N or less, and more preferably 5.0 N or less. The shear fracture strength is measured, for example, in accordance with the surface-interface cutting method (SAICAS method). If the shear fracture strength of the resin film is within this range, it is possible to suppress the occurrence of cracks extending in a direction perpendicular to the thickness direction (plane direction, horizontal direction) at the end face of the resin film (processed film) after external processing.

[0013] The thickness of the resin film 1 is, for example, 10 μm or more, preferably 30 μm or more, and more preferably 40 μm or more. On the other hand, the thickness of the resin film 1 is, for example, 130 μm or less, preferably 100 μm or less, and more preferably 80 μm or less. If the thickness of the resin film is within this range, the occurrence of cracks during external processing can be stably suppressed.

[0014] The resin film will be described in detail below.

[0015] B. Resin film The resin film 1 contains any suitable resin material as a main component. Specific examples of the resin material include transparent resins such as cycloolefin (COP) resins such as polynorbornene resins, polyester resins such as polyethylene terephthalate (PET) resins, cellulose resins such as triacetyl cellulose (TAC), polycarbonate (PC) resins, (meth)acrylic resins, polyvinyl alcohol resins, polyamide resins, polyimide resins, polyethersulfone resins, polysulfone resins, polystyrene resins, polyolefin resins, and acetate resins. In addition, the resin may be a thermosetting resin or an ultraviolet-curing resin such as a (meth)acrylic resin, a urethane resin, a (meth)acrylic urethane resin, an epoxy resin, or a silicone resin. The term "(meth)acrylic resin" refers to an acrylic resin and / or a methacrylic resin. In addition, glassy polymers such as siloxane polymers may also be used. The polymer film described in JP-A-2001-343529 (WO01 / 37007) may also be used. The material of this film may be, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in the side chain, and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in the side chain, such as a resin composition having an alternating copolymer of isobutene and N-methylmaleimide, and an acrylonitrile-styrene copolymer. The polymer film may be, for example, an extrusion product of the above resin composition. The materials of the resin film may be used alone or in combination.

[0016] Of these resin materials, preferably, PC-based resins are used.

[0017] The PC resin contains at least a structural unit derived from a dihydroxy compound having a bond structure represented by the following structural formula (1), and is produced by reacting a dihydroxy compound containing at least a dihydroxy compound having at least one bond structure -CH2-O- in the molecule with a carbonate diester in the presence of a polymerization catalyst. In other words, the PC resin contains a structural unit derived from a dihydroxy compound and a carbonate group derived from a carbonate diester. [ka]

[0018] Here, as the dihydroxy compound having a bond structure represented by structural formula (1), any compound can be used as long as it has two alcoholic hydroxyl groups, contains a structure having a linking group -CH2-O- in the molecule, and can react with a carbonate diester in the presence of a polymerization catalyst to produce a polycarbonate, and multiple types of compounds can be used in combination.

[0019] In addition, a dihydroxy compound not having the bond structure represented by the above structural formula (1) may be used in combination as a dihydroxy compound for use in a PC resin. Hereinafter, a dihydroxy compound having the bond structure represented by structural formula (1) may be abbreviated as dihydroxy compound (A), and a dihydroxy compound not having the bond structure represented by structural formula (1) may be abbreviated as dihydroxy compound (B).

[0020] (Dihydroxy compound (A)) The "linking group -CH2-O-" in the dihydroxy compound (A) means a structure that bonds with atoms other than hydrogen atoms to form a molecule. In this linking group, the atom to which at least an oxygen atom can be bonded or the atom to which a carbon atom and an oxygen atom can be bonded simultaneously is preferably a carbon atom. The number of "linking groups -CH2-O-" in the dihydroxy compound (A) is preferably 1 or more, more preferably 2 to 4.

[0021] Specific examples of the dihydroxy compound (A) include 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-methylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-isopropylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-isobutylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-tert-butylphenyl)fluorene, and 9,9-bis(4-(2-hydroxyethoxy)-3-tert-butylphenyl)fluorene. )-3-cyclohexylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-phenylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3,5-dimethylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-tert-butyl-6-methylphenyl)fluorene, and 9,9-bis(4-(3-hydroxy-2,2-dimethylpropoxy)phenyl)fluorene;Bis[4-(2-hydroxyethoxy)phenyl]methane, bis[4-(2-hydroxyethoxy)phenyl]diphenylmethane, 1,1-bis[4-(2-hydroxyethoxy)phenyl]ethane, 1,1-bis[4-(2-hydroxyethoxy)phenyl]-1-phenylethane, 2,2-bis[4-(2-hydroxyethoxy)phenyl]propane, 2,2-bis[4-(2-hydroxyethoxy)-3-methylphenyl]propane, 2,2-bis[3,5-dimethyl-4-(2-hydroxyethoxy)phenyl] 1,1-bis[4-(2-hydroxyethoxy)phenyl]propane, 1,1-bis[4-(2-hydroxyethoxy)phenyl]-3,3,5-trimethylcyclohexane, 1,1-bis[4-(2-hydroxyethoxy)phenyl]cyclohexane, 1,4-bis[4-(2-hydroxyethoxy)phenyl]cyclohexane, 1,3-bis[4-(2-hydroxyethoxy)phenyl]cyclohexane, 2,2-bis[4-(2-hydroxyethoxy)-3-phenylphenyl]propane, 2,2-bis[(2-hydroxyethoxy)-3-phenylphenyl]propane, isopropylphenyl]propane, 2,2-bis[3-tert-butyl-4-(2-hydroxyethoxy)phenyl]propane, 2,2-bis[4-(2-hydroxyethoxy)phenyl]butane, 2,2-bis[4-(2-hydroxyethoxy)phenyl]-4-methylpentane, 2,2-bis[4-(2-hydroxyethoxy)phenyl]octane, 1,1-bis[4-(2-hydroxyethoxy)phenyl]decane, 2,2-bis[3-bromo-4-(2-hydroxyethoxy)phenyl]propane bis(hydroxyalkoxyaryl)alkanes, such as 2,2-bis[3-cyclohexyl-4-(2-hydroxyethoxy)phenyl]propane; bis(hydroxyalkoxyaryl)cycloalkanes, such as 1,1-bis[4-(2-hydroxyethoxy)phenyl]cyclohexane, 1,1-bis[3-cyclohexyl-4-(2-hydroxyethoxy)phenyl]cyclohexane, and 1,1-bis[4-(2-hydroxyethoxy)phenyl]cyclopentane;Dihydroxyalkoxy diaryl ethers, such as 4,4'-bis(2-hydroxyethoxy)diphenyl ether and 4,4'-bis(2-hydroxyethoxy)-3,3'-dimethyldiphenyl ether; bishydroxyalkoxy aryl sulfides, such as 4,4'-bis(2-hydroxyethoxyphenyl) sulfide and 4,4'-bis[4-(2-dihydroxyethoxy)-3-methylphenyl] sulfide; bishydroxyalkoxy aryl sulfoxides, such as 4,4'-bis(2-hydroxyethoxyphenyl) sulfone and 4,4'-bis[4-(2- bishydroxyalkoxyarylsulfones, such as 1,4-bishydroxyethoxybenzene, bishydroxyalkoxybenzenes, such as 1,3-bis[2-[4-(2-hydroxyethoxy)phenyl]propyl]benzene, 1,4-bis[2-[4-(2-hydroxyethoxy)phenyl]propyl]benzene, 4,4'-bis(2-hydroxyethoxy)biphenyl, 1,3-bis[4-(2-hydroxyethoxy)phenyl]-5,7-dimethyladamantane, anhydrous sugar alcohols, such as dihydroxy compounds represented by the following formula (2), and compounds having a cyclic ether structure, such as spiro glycols, such as those represented by the following general formula (3). The dihydroxy compounds (A) may be used alone or in combination.

[0022] [ka]

[0023] [ka]

[0024] Of these dihydroxy compounds (A), preferred is the dihydroxy compound represented by the above formula (2). Examples of the dihydroxy compound represented by the above formula (2) include isosorbide, isomannide, and isoidite, which are stereoisomeric, and these may be used alone or in combination of two or more. Among the dihydroxy compounds (A), isosorbide obtained by dehydration condensation of sorbitol produced from various starches, which are abundant and easily available as resources, is most preferred in terms of availability, ease of production, optical properties, and moldability.

[0025] The ratio of the structural units derived from the dihydroxy compound (A) to the total structural units derived from the dihydroxy compounds contained in the PC resin is, for example, 10 mol% or more, preferably 40 mol% or more, and more preferably 60 mol% or more. On the other hand, the ratio of the structural units derived from the dihydroxy compound (A) is, for example, 100 mol% or less, preferably 90 mol% or less, more preferably 80 mol% or less, and even more preferably 70 mol% or less. When the ratio of the dihydroxy compound (A) is within the above range, the Charpy tensile impact strength of the resin film can be stably adjusted to the above range.

[0026] (Dihydroxy Compound (B)) As the dihydroxy compound that is the structural unit of the PC resin, dihydroxy compound (A) and dihydroxy compound (B) can be used together. By using dihydroxy compounds (A) and (B) in combination, the Charpy tensile impact strength of the resin film can be more stably adjusted to the above range.

[0027] The dihydroxy compound (B) is typically a dihydroxy compound other than the dihydroxy compound (A). Examples of the dihydroxy compound (B) include alicyclic dihydroxy compounds, aliphatic dihydroxy compounds, oxyalkylene glycols, aromatic dihydroxy compounds, and diols having a cyclic ether structure. The dihydroxy compounds (B) may be used alone or in combination. Of the dihydroxy compounds (B), preferably, alicyclic dihydroxy compounds are used.

[0028] The alicyclic dihydroxy compound is not particularly limited, but preferably includes a compound having a 5-membered ring structure or a 6-membered ring structure. The 6-membered ring structure may be fixed to a chair or boat shape by a covalent bond. When the alicyclic dihydroxy compound has a 5-membered ring or a 6-membered ring structure, the heat resistance of the resulting PC resin can be improved. The number of carbon atoms contained in the alicyclic dihydroxy compound is, for example, 70 or less, preferably 50 or less, more preferably 30 or less.

[0029] Specific examples of the alicyclic dihydroxy compound containing a 5-membered ring structure or a 6-membered ring structure include alicyclic dihydroxy compounds represented by the following general formula (I) or (II). HOCH2-R 1 -CH2OH (I) H.O.R. 2 -OH (II) (In formulas (I) and (II), R 1 and R 2 Each of represents a cycloalkylene group having 4 to 20 carbon atoms.

[0030] Cyclohexanedimethanol, which is an alicyclic dihydroxy compound represented by the above general formula (I), is 1 is represented by the following general formula (Ia) (wherein R 3 represents an alkyl group having 1 to 12 carbon atoms or a hydrogen atom. Specific examples of such isomers include 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, and 1,4-cyclohexanedimethanol.

[0031] [ka]

[0032] The alicyclic dihydroxy compound represented by the above general formula (I), tricyclodecane dimethanol or pentacyclopentadecanedimethanol, is represented by the general formula (I), 1 is represented by the following general formula (Ib) (wherein n is 0 or 1):

[0033] [ka]

[0034] Decalin dimethanol or tricyclotetradecane dimethanol, which is an alicyclic dihydroxy compound represented by the above general formula (I), is a compound represented by the general formula (I) 1 is represented by the following general formula (Ic) (wherein m is 0 or 1). Specific examples of such isomers include 2,6-decalin dimethanol, 1,5-decalin dimethanol, and 2,3-decalin dimethanol.

[0035] [ka]

[0036] Norbornane dimethanol, which is an alicyclic dihydroxy compound represented by the above general formula (I), is 1 The isomers include various isomers represented by the following general formula (Id): Specific examples of such isomers include 2,3-norbornane dimethanol and 2,5-norbornane dimethanol.

[0037] [ka]

[0038] Adamantane dimethanol, which is an alicyclic dihydroxy compound represented by general formula (I), is 1The isomers include various isomers represented by the following general formula (Ie): A specific example of such isomers is 1,3-adamantanedimethanol.

[0039] [ka]

[0040] Cyclohexanediol, which is an alicyclic dihydroxy compound represented by the above general formula (II), is 2 is represented by the following general formula (IIa) (wherein R 3 represents an alkyl group having 1 to 12 carbon atoms or a hydrogen atom. Specific examples of such isomers include 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, and 2-methyl-1,4-cyclohexanediol.

[0041] [ka]

[0042] The alicyclic dihydroxy compound represented by the above general formula (II), tricyclodecanediol or pentacyclopentadecanediol, is a compound represented by the general formula (II), 2 is represented by the following general formula (IIb) (wherein n is 0 or 1):

[0043] [ka]

[0044] Decalindiol or tricyclotetradecanediol, which is an alicyclic dihydroxy compound represented by the above general formula (II), is a compound represented by the general formula (II) in which R 2is represented by the following general formula (IIc) (wherein m is 0 or 1). Specific examples of such isomers include 2,6-decalindiol, 1,5-decalindiol, and 2,3-decalindiol.

[0045] [ka]

[0046] Norbornanediol, which is an alicyclic dihydroxy compound represented by the above general formula (II), is 2 The isomers include various isomers represented by the following general formula (IId): Specific examples of such isomers include 2,3-norbornanediol and 2,5-norbornanediol.

[0047] [ka]

[0048] The adamantanediol, which is an alicyclic dihydroxy compound represented by the above general formula (II), is represented by the following general formula (II): 2 is represented by the following general formula (IIe): A specific example of such an isomer is 1,3-adamantanediol.

[0049] [ka]

[0050] Among the specific examples of the alicyclic dihydroxy compound described above, preferred are cyclohexanedimethanols, tricyclodecane dimethanols, adamantanediols, and pentacyclopentadecanedimethanols. From the viewpoints of availability and ease of handling, more preferred are 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, and tricyclodecane dimethanol, and even more preferred is tricyclodecane dimethanol.

[0051] The ratio of the structural units derived from the dihydroxy compound (B) to the total structural units derived from the dihydroxy compounds contained in the PC resin is, for example, 0 mol% or more, preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 30 mol% or more. On the other hand, the ratio of the structural units derived from the dihydroxy compound (B) is, for example, 90 mol% or less, preferably 60 mol% or less, and more preferably 40 mol% or less.

[0052] Details of these PC resins are described, for example, in JP 2012-31370 A (Patent No. 5448264), the disclosure of which is incorporated herein by reference.

[0053] In one embodiment, the PC resin contains a structural unit derived from the dihydroxy compound (A) represented by the above formula (2), a structural unit derived from the alicyclic dihydroxy compound (B) represented by the above general formula (I), and a carbonate group linking them together. When a PC resin containing these structural units is applied to a resin film, the Charpy tensile impact strength of the resin film can be adjusted to the above range more stably. In such a PC resin, the molar ratio (A:B) of the structural unit derived from the dihydroxy compound (A) represented by the above formula (2) to the structural unit derived from the alicyclic dihydroxy compound (B) represented by the above general formula (I) is, for example, 5:5 to 9:1, and preferably 6:4 to 8:2. In such a PC resin, the combination of the dihydroxy compound (A) represented by the above formula (2) and the alicyclic dihydroxy compound (B) represented by the above general formula (I) is preferably a combination of isosorbide and tricyclodecane dimethanol.

[0054] The resin film 1 may contain any suitable additive in addition to the above-mentioned resin material. Examples of the additive include antioxidants, ultraviolet absorbers, light stabilizers, nucleating agents, fillers, pigments, surfactants, and antistatic agents. Any suitable surface treatment layer may be provided on the surface of the resin film 1. Examples of the surface treatment layer include a hard coat layer, an easy-adhesion layer, an easy-slip layer, an antiblocking layer, an antistatic layer, an antireflection layer, and an oligomer prevention layer.

[0055] The resin film 1 typically has optical isotropy. In this specification, the term "optically isotropic" means that the in-plane retardation Re(550) and the retardation Rth(550) in the thickness direction are within the following ranges. The in-plane retardation Re(550) of the resin film 1 is, for example, 10 nm or less, preferably 5 nm or less, and more preferably 3 nm or less. On the other hand, the lower limit of the in-plane retardation Re(550) of the resin film 1 is typically 0 nm. The resin film 1 has a thickness direction retardation Rth(550) of, for example, −10 nm to +10 nm, and preferably −5 nm to +5 nm.

[0056] The resin film 1 has a total light transmittance of, for example, 80% or more, preferably 85% or more, more preferably 90% or more, and even more preferably 95% or more. The haze value of the resin film 1 is, for example, 2.0% or less, preferably 1.5% or less, more preferably 1.0% or less, even more preferably 0.7% or less, particularly preferably 0.5% or less, and particularly preferably 0.3% or less. The lower limit of the haze value of the resin film 1 is typically 0.05%. If the total light transmittance and / or haze value of the resin film is within such range, the resin film can be suitably used for optical applications.

[0057] C. Applications of resin films The resin films described in the above items A and B can be applied to various industrial products, such as optical members such as polarizing plates, decorative films, and product protection films. The above-mentioned resin film is particularly suitable for use as a polarizing plate and a decorative film.

[0058] C-1.Decorative film Although not shown, in one embodiment, the resin film 1 is applied to a decorative film. More specifically, the resin film 1 can be used as a substrate of the decorative film. The decorative film includes the resin film 1 as a substrate, an adhesive layer provided on one surface of the resin film 1, and a printed layer provided on the surface of the adhesive layer opposite the substrate. Such a decorative film is attached to the surface of an adherend so that the printed layer is in contact with the adherend. The decorative film is then heated as necessary and then peeled off from the surface of the adherend. The printed layer is then transferred to the surface of the adherend, and the desired design can be imparted to the adherend.

[0059] C-2.Polarizing plate As shown in Figs. 2 and 3, the resin film 1 may be applied to a polarizing plate 100. More specifically, the resin film 1 may be employed as a protective layer for a polarizer 2. The polarizing plate 100 includes a polarizer 2 and a resin film 1 serving as a protective layer. The resin film 1 is disposed on at least one side of the polarizer 2. The resin film 1 is typically attached to the polarizer 2 via any appropriate adhesive layer (adhesive layer or pressure-sensitive adhesive layer). As shown in Fig. 3, the resin film 1 serving as a protective layer may be provided on both sides of the polarizer 2.

[0060] C-2-1.Polarizer Any appropriate polarizer may be adopted as the polarizer 2. For example, the resin film forming the polarizer may be composed of a single-layer resin film, or may be prepared using a laminate of two or more layers.

[0061] Specific examples of polarizers made of a single-layer resin film include hydrophilic polymer films such as polyvinyl alcohol (PVA) films, partially formalized PVA films, and partially saponified ethylene-vinyl acetate copolymer films that have been dyed with a dichroic substance such as iodine or a dichroic dye and stretched, and polyene-based oriented films such as dehydrated PVA films and dehydrochlorinated polyvinyl chloride films. A polarizer obtained by dyeing a PVA film with iodine and uniaxially stretching it is preferable because of its excellent optical properties.

[0062] Specific examples of polarizers obtained using a laminate include a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a polarizer obtained using a laminate of a resin substrate and a PVA-based resin layer formed by coating on the resin substrate. A polarizer obtained using a laminate of a resin substrate and a PVA-based resin layer formed by coating on the resin substrate can be produced by, for example, applying a PVA-based resin solution to the resin substrate and drying the resin substrate to form a PVA-based resin layer on the resin substrate to obtain a laminate of the resin substrate and the PVA-based resin layer; stretching and dyeing the laminate to make the PVA-based resin layer into a polarizer. In one embodiment of the present invention, a polyvinyl alcohol-based resin layer containing a halide and a polyvinyl alcohol-based resin is preferably formed on one side of the resin substrate. The stretching typically includes immersing the laminate in an aqueous boric acid solution to stretch it. Furthermore, the stretching may further include, as necessary, stretching the laminate in air at a high temperature (for example, 95° C. or higher) before stretching in the aqueous boric acid solution. In addition, in one embodiment of the present invention, the laminate is preferably subjected to a drying shrinkage treatment in which the laminate is heated while being transported in the longitudinal direction to shrink the laminate by 2% or more in the width direction. Typically, the manufacturing method of this embodiment includes subjecting the laminate to an air-assisted stretching treatment, a dyeing treatment, an underwater stretching treatment, and a drying shrinkage treatment in this order. By introducing the auxiliary stretching, even when PVA is applied onto a thermoplastic resin, it is possible to increase the crystallinity of PVA, and to achieve high optical properties. At the same time, by increasing the orientation of PVA in advance, problems such as a decrease in the orientation of PVA or dissolution when immersed in water in the subsequent dyeing step or stretching step can be prevented, and high optical properties can be achieved. Furthermore, when the PVA-based resin layer is immersed in a liquid, the disorder of the orientation of polyvinyl alcohol molecules and the decrease in the orientation can be suppressed compared to when the PVA-based resin layer does not contain a halide. This can improve the optical properties of a polarizer obtained through a treatment step in which the laminate is immersed in a liquid, such as a dyeing treatment and an underwater stretching treatment. Furthermore, the optical properties can be improved by shrinking the laminate in the width direction through drying shrinkage treatment.The obtained laminate of resin substrate / polarizer may be used as it is (i.e., the resin substrate may be used as a protective layer for the polarizer), or the resin substrate may be peeled off from the laminate of resin substrate / polarizer, and any suitable protective layer may be laminated on the peeled surface depending on the purpose. Details of the method for producing such a polarizer are described in, for example, JP2012-73580A and JP6470455A. The entire disclosures of these publications are incorporated herein by reference.

[0063] The dyeing with iodine is carried out, for example, by immersing the PVA-based film in an aqueous iodine solution. The stretching ratio of the uniaxial stretching is preferably 3 to 7 times. The stretching may be carried out after the dyeing treatment, or may be carried out while dyeing. Alternatively, the film may be stretched and then dyed. If necessary, the PVA-based film may be subjected to a swelling treatment, a crosslinking treatment, a washing treatment, a drying treatment, or the like. For example, by immersing the PVA-based film in water and washing it with water before dyeing, it is possible to wash off dirt and antiblocking agents on the surface of the PVA-based film, and also to swell the PVA-based film and prevent uneven dyeing.

[0064] The thickness of the polarizer 2 is, for example, 1 μm to 80 μm, preferably 1 μm to 15 μm, more preferably 1 μm to 12 μm, and further preferably 3 μm to 12 μm. When the thickness of the polarizer is within this range, curling during heating can be well suppressed and good appearance durability during heating can be obtained.

[0065] The polarizer 2 typically exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The single transmittance of the polarizer 2 is, for example, 41.5% to 46.0%, preferably 43.0% to 46.0%, and more preferably 44.5% to 46.0%. The degree of polarization of the polarizer 2 is preferably 97.0% or more, more preferably 99.0% or more, and even more preferably 99.9% or more.

[0066] D. External shape processing In one embodiment, the resin film described in A and B above, or the product including the resin film described in C above is processed to have a desired shape. This produces a processed film 3 (or a product including the processed film 3) having a desired outer shape.

[0067] Any suitable method may be used for the external processing. Examples of the external processing include punching using a punching blade, cutting using a spindle, and laser processing. Among these external processing, laser processing is preferable. Various conditions in the external processing can be adjusted arbitrarily and appropriately.

[0068] The outer shape of the processed film 3 (or the product including the processed film 3) is not particularly limited. Examples of such shapes include a rectangular shape and irregular shapes other than a rectangular shape. Examples of irregular shapes include a polygonal shape other than a square shape, a circular shape, an elliptical shape, and a shape having an irregularly shaped portion.

[0069] 4, in one embodiment, the processed film 3 (or a product including the processed film 3) has a contoured portion 31. Examples of the contoured portion 31 include a recess recessed inward from the outer edge of the processed film 3 and a through hole penetrating the processed film 3. In the illustrated example, the processed film 3 has a recess 31a as a contoured portion. The shape of the recess is not particularly limited, and examples thereof include a V-shape and a U-shape.

[0070] When a resin film (or a product containing a resin film) is processed into an irregular shape, cracks extending in the thickness direction are more likely to occur on the end faces of the resin film than when the resin film (or a product containing a resin film) is processed into a rectangular shape. On the other hand, in one embodiment, the Charpy tensile impact strength of the resin film is 400 kJ / m 2 For the above reasons, even if the resin film (or a product containing a resin film) is contour-processed into an irregular shape as described above, the occurrence of cracks extending in the thickness direction on the edge faces of the processed film can be stably suppressed. EXAMPLES

[0071] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. The methods for measuring the various properties are as follows.

[0072] (1) Measurement of Charpy tensile impact strength of resin film The Charpy tensile impact strength of the resin films obtained in the examples and comparative examples was measured in accordance with JIS K7160 Method A. The results are shown in Table 1. More specifically, the resin film was cut into three shapes (length 80 mm, width 15 mm) to prepare samples. Then, both ends of the sample were fixed to a support so that the sample would not move due to the impact when punching with a hammer, and the energy required to break the film (i.e., impact absorption energy) was measured as the Charpy tensile impact strength using a digital impact tester DG-UB (manufactured by Toyo Seiki Seisakusho Co., Ltd.) with a nominal pendulum energy of 2.0 J and a lifting angle of 150 degrees (i.e., impact absorption energy). The greater this impact absorption energy, the more resistant the film is to crack.

[0073] (2) Presence or absence of cracks in the resin film during processing into different shapes The resin films obtained in the examples and comparative examples were processed using a punching tool to obtain processed films having recesses as irregularly shaped parts. The end faces of the processed films were then checked for the presence or absence of cracks extending in the thickness direction (vertical direction). The results are shown in Table 1.

[0074] [Example 1] 81.98 parts by mass of isosorbide (ISB), 47.19 parts by mass of tricyclodecane dimethanol (TCDDM), 175.1 parts by mass of diphenyl carbonate (DPC), and 0.979 parts by mass of cesium carbonate 0.2% by mass aqueous solution as a catalyst were charged into a reaction vessel, and in a nitrogen atmosphere, the temperature of the heating vessel was heated to 150°C as the first step of the reaction, and the raw materials were dissolved (about 15 minutes) while stirring as necessary. Next, the pressure was changed from normal pressure to 13.3 kPa, and the temperature of the heating vessel was raised to 190°C in one hour, while the generated phenol was extracted outside the reaction vessel. After the entire reaction vessel was kept at 190°C for 15 minutes, the pressure in the reaction vessel was changed to 6.67 kPa, the temperature of the heating vessel was raised to 230°C in 15 minutes, and the generated phenol was extracted outside the reaction vessel as the second step. As the stirring torque of the stirrer increased, the temperature was raised to 250°C in 8 minutes, and the pressure in the reaction vessel was allowed to reach 0.200 kPa or less in order to remove the phenol that was generated. After reaching a predetermined stirring torque, the reaction was terminated, and the reaction product was extruded into water to obtain pellets of PC-based resin. The obtained PC-based resin was vacuum-dried at 100°C for 12 hours, and then a PC-based resin film with a thickness of 40 μm was produced using a film-forming device equipped with a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., cylinder setting temperature: 250°C), a T-die (width 1700 mm, setting temperature: 250°C), a cast roll (setting temperature: 60°C) and a winder. The in-plane retardation Re (550) of the PC-based resin film was 3.0 nm.

[0075] [Comparative Example 1] An acrylic resin film (manufactured by Kaneka Corporation, product name "HTX-Z") having a thickness of 40 μm was prepared.

[0076] [Table 1]

[0077] [evaluation] As is clear from Table 1, the Charpy tensile impact strength of the resin film is 400 kJ / m 2It can be seen that the above can suppress the occurrence of cracks extending in the vertical direction on the end faces of the resin film during contour processing. [Industrial Applicability]

[0078] The resin film of the present invention can be applied to various industrial products, and can be particularly suitably used for optical members such as decorative films and polarizing plates. [Explanation of symbols]

[0079] 1 Resin film 2 Polarizer 3. Processed Film

Claims

1. Charpy tensile impact strength is 400 kJ / m ２ That's it, the resin film.

2. The resin film according to claim 1 , which is made of a polycarbonate-based resin.

3. A method for producing a processed film, comprising processing the resin film according to claim 1 or 2 into an outer shape.

Images