Film, polarizing sheet, heat bent molding, and sunglasses

Abstract

To provide a film with low light transmittance at wavelengths of 420nm or less and excellent heat resistance, and a polarizing sheet, a heat bent molding, and sunglasses.SOLUTION: A film includes: an aromatic polycarbonate resin; an ultraviolet absorber having a triazine structure; and a pigment that absorbs a specified wavelength and has a maximum absorption wavelength between 400 and 440 nm.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a film, a polarizing sheet, a heat-bent molded product, and sunglasses, and more particularly to a film containing a polycarbonate resin as a main component. [Background technology]

[0002] Polycarbonate resin is produced by the condensation polymerization of aromatic diols such as bisphenol A and carbonate precursors such as phosgene. It has excellent impact strength, numerical stability, heat resistance, and transparency, and is used in a wide range of fields, including exterior materials for electrical and electronic products, automotive parts, building materials, and optical components.

[0003] On the other hand, optical lenses used in sunglasses and the like are required to have a transmittance that does not affect the field of vision while preventing glare from external light sources. They also need to protect the eyes from harmful light rays of specific wavelengths, such as ultraviolet rays. Therefore, various technologies have been developed for using polycarbonate resin, which has excellent optical properties in addition to mechanical properties, in optical lenses for sunglasses and other outdoor activities (Patent Document 1, Patent Document 2, etc.). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-202542 [Patent Document 2] International Publication No. 2019 / 066493 Summary of the Invention [Problem to be solved by the invention]

[0005] As mentioned above, the incorporation of an ultraviolet absorber into the polycarbonate resin used in sunglasses lenses has been investigated. However, when attempting to provide sunglasses with vision correction capabilities, the lens thickness varies depending on the eyeglass prescription. Therefore, it is necessary to incorporate an ultraviolet absorber into a layer other than the lens. Here, sunglasses or eyeglasses have a layer structure, for example, as shown in FIG. 1, specifically, a lens 1 and a polarizing film 2, with polarizing film substrates 3 and 4 typically provided on both sides of the polarizing film 2. Here, if a UV absorber is not incorporated into lens 1, it is conceivable to incorporate an ultraviolet absorber into polarizing film substrate 3 or polarizing film substrate 4. On the other hand, to prevent cataracts, etc., it is necessary to block light in the wavelength range up to about 420 nm. Also, depending on the use of sunglasses, heat resistance may be required. The present invention aims to solve these problems by providing a film that has low light transmittance for wavelengths of 420 nm or less and excellent heat resistance, as well as a polarizing sheet, a heat-bent molded product, and sunglasses. [Means for solving the problem]

[0006] As a result of investigations conducted by the inventors in light of the above problems, the above problems were solved by the following means. [1] A film comprising an aromatic polycarbonate resin, an ultraviolet absorber having a triazine structure, and a specific wavelength absorbing dye having a maximum absorption wavelength in the wavelength range of 400 to 440 nm. [2] The film according to [1], wherein the thickness of the film is 200 to 500 μm. [3] The film according to [1] or [2], wherein the concentration of the specific wavelength absorbing dye is 2 to 50 ppm by mass per 100 parts by mass of the polycarbonate resin. [4] The film according to any one of [1] to [3], wherein the ultraviolet absorber having a triazine structure includes a compound represented by formula (UV-1). [ka] (In formula (UV-1), R 1is a hydrocarbon group having 1 to 10 carbon atoms or a group consisting of a combination of a hydrocarbon group having 1 to 10 carbon atoms and -O- and / or -C(=O)-, and R 2 ~R 4 are each independently a hydroxyl group, a hydrocarbon group having 1 to 10 carbon atoms, or a group formed by combining a hydrocarbon group having 1 to 10 carbon atoms with -O- and / or -C(=O)-, and n2 is an integer of 0 to 3, n3 and n4 each independently represent an integer of 0 to 4. [5] The film according to [4], wherein n3 and n4 are each independently an integer of 1 to 4. [6] The film according to any one of [1] to [3], wherein the ultraviolet absorber having a triazine structure includes a compound represented by formula (UV-2). [ka] (In formula (UV-2), R 11 and R 31 , R 41 are each independently an aliphatic hydrocarbon group having 3 to 10 carbon atoms, and R 2 , R 32 , and ,R 42 are each independently a hydroxyl group, a hydrocarbon group having 1 to 10 carbon atoms, or a group consisting of a combination of a hydrocarbon group having 1 to 10 carbon atoms and -O- and / or -C(=O)-, and n2, n3-1, and n4-1 are each independently an integer of 0 to 3. [7] The film according to any one of [1] to [3], wherein the ultraviolet absorber having a triazine structure includes a compound represented by formula (UV-3). [ka] (In formula (UV-3), R 11 and R 31 , R 41 are each independently an aliphatic hydrocarbon group having 3 to 10 carbon atoms. [8] The film according to any one of [1] to [7], wherein the film has a light transmittance of less than 15% at a wavelength of 420 nm. [9] The film according to any one of [1] to [8], wherein the film has a light transmittance of less than 15% at a wavelength of 380 nm.

[10] A polarizing sheet comprising the film according to any one of [1] to [9] and a polarizing film.

[11] A heat-bent product of the polarizing sheet according to

[10] .

[12] Sunglasses having the polarizing sheet described in

[10] . [Effects of the Invention]

[0007] The present invention makes it possible to provide a film that has low transmittance for light having a wavelength of 420 nm or less and excellent heat resistance, as well as a polarizing sheet, a heat-bent product, and sunglasses. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a schematic diagram illustrating an example of a layer structure of the heat-bent molded body of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. Note that the present embodiment is an example for explaining the present invention, and the present invention is not limited to only this embodiment. In this specification, the symbol "to" is used to mean that the numerical values ​​before and after it are included as upper and lower limits. "A to B" means that the range is A or more and B or less. In addition, any combination of the upper and lower limit values ​​of the numerical values ​​in this specification is an example of this embodiment.

[0010] In this specification, various physical properties and characteristic values ​​are those at 23°C unless otherwise specified.

[0011] In this specification, weight average molecular weights are measured by gel permeation chromatography unless otherwise specified. Specifically, the gel permeation chromatography apparatus used was an LC-20AD system (Shimadzu Corporation), and an LF-804 (Shodex Corporation) was connected to the column. The column temperature was set to 40°C. The detector used was an RID-10A (Shimadzu Corporation) RI detector. Chloroform was used as the eluent, and a calibration curve was prepared using standard polystyrene (Tosoh Corporation).

[0012] In this specification, unless otherwise specified, the glass transition temperature (Tg) is a value measured by differential scanning calorimetry (DSC) in accordance with ISO 11357. Two cycles of temperature increase and decrease are performed according to the conditions of the differential scanning calorimetry (DSC measurement), and the glass transition temperature during the second temperature increase cycle is measured. The intersection of the line drawn by extending the low-temperature baseline toward the high-temperature side and the tangent to the inflection point is the glass transition temperature (Tg). Measurement starting temperature: 30°C, heating rate: 10°C / min, final temperature: 250°C, cooling rate: 20°C / min. Units are °C. A differential scanning calorimeter (DSC, manufactured by Hitachi High-Tech Science Corporation, model number "DSC7020") can be used as the measuring device.

[0013] As used herein, the term "film" refers to a generally flat molded body that is thin relative to its length and width. The term "film" as used herein also includes "sheet." The film may be single-layered or multi-layered. In this specification, ppm means ppm by mass. If the measurement methods, etc. described in the standards shown in this specification change from year to year, they will be based on the standards in effect as of January 1, 2024, unless otherwise specified. If the measurement methods, etc. described in the standards shown in this specification are abolished as of January 1, 2024, they will be based on the standards in effect at the time of abolition. The scale of Figure 1 may not be consistent with reality.

[0014] The film of the present embodiment is characterized by containing an aromatic polycarbonate resin, an ultraviolet absorber having a triazine structure (sometimes referred to herein as a "triazine-based ultraviolet absorber"), and a specific wavelength absorbing dye having a maximum absorption wavelength in the wavelength range of 400 to 440 nm (sometimes referred to herein simply as a "specific wavelength absorbing dye (C)"). By adopting such a constitution, a film having low transmittance for light having a wavelength of 420 nm or less and excellent heat resistance can be obtained. The use of a yellow dye has been considered to block light with a wavelength of 420 nm. However, yellow dyes tend to make the resulting film too yellow and also tend to absorb light in wavelength regions where light blocking properties are not required. In particular, when polycarbonate resin films containing a yellow dye are laminated to both sides of a polarizing film, color change tends to occur more easily than with polycarbonate resin films that do not contain a yellow dye. The color change is particularly significant when the film is heated. In this embodiment, by using a UV absorber having a triazine structure in combination with a specific wavelength absorbing dye having a maximum absorption wavelength between 400 and 440 nm, it is possible to effectively block light up to wavelengths of about 420 nm while minimizing color change even when heated. This is presumably because the specific wavelength absorbing dye (C) exhibits a sharp absorption spectrum, and therefore can fully absorb light in the wavelength range of about 400 to 420 nm even in small amounts. Furthermore, it is presumed that the use of a triazine-based UV absorber can fully absorb light in the wavelength range of about 380 nm while minimizing color change due to heat resistance. Furthermore, the film of the present embodiment tends to be able to effectively suppress roll contamination caused by additives by using a triazine-based ultraviolet absorber and a specific wavelength absorbing dye (C).

[0015] Hereinafter, the embodiments of the present invention will be described in detail. However, the explanation of the constituent elements described below is an example of an embodiment of the present invention, and the present invention is not limited to these contents.

[0016] <Aromatic polycarbonate resin> The resin composition of the present embodiment contains an aromatic polycarbonate resin. The aromatic polycarbonate resin in this embodiment is, for example, a polycarbonate resin in which 80% by mass or more of the structural units constituting the polycarbonate resin are structural units derived from aromatic monomers. The proportion of structural units derived from aromatic monomers in the polycarbonate resin used in this embodiment is preferably 85% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and even more preferably 99% by mass or more. Examples of the aromatic monomer include bisphenol A, bisphenol C, and bisphenol AP, with bisphenol A and / or bisphenol AP being preferred, and bisphenol A being more preferred. An example of the aromatic polycarbonate resin used in this embodiment is a resin containing the structural unit represented by formula (A) in a proportion of 80 mass % or more of all structural units. The proportion of the structural unit represented by formula (A) in the aromatic polycarbonate resin used in this embodiment may be 100 mass % excluding the terminal groups. Formula (A) [ka] In the above formula (A), n is an arbitrary number.

[0017] In the present embodiment, examples of the diol component constituting the aromatic polycarbonate resin include 4,4'-isopropylidenediphenol, as well as bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)sulfoxide, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)ketone, 1,1-bis(4-hydroxyphenyl)ethane, bisphenol A, 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 2,2-bis(4-hydroxyphenyl)ethane, bisphenol A, 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 2,2-bis(4-hydroxyphenyl)ethane, bisphenol B, 2,2-bis(4-hydroxyphenyl)ethane, bisphenol C ... B, 2,2-bis(4-hydroxyphenyl)ethane, bisphenol B, 2,2-bis(4-hydroxyphenyl)ethane, bisphenol B, 2,2-bis(4-hydroxyphenyl)ethane, bisphenol B, 2,2-bis(4-hydroxyphenyl)ethane, bisphenol B, 2,2 Examples include 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-bis(4-hydroxy-3-chlorophenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, bis(4-hydroxyphenyl)diphenylmethane, and a,ω-bis[3-(ο-hydroxyphenyl)propyl]polydimethylsiloxane.

[0018] The molecular weight of the aromatic polycarbonate resin in this embodiment is not particularly limited, but is preferably 20,000 or more, more preferably 30,000 or more, in weight-average molecular weight. The weight-average molecular weight is preferably 100,000 or less, more preferably 70,000 or less. By setting the weight-average molecular weight at or above the lower limit, the strength of the resulting multilayer body for hot bending can be increased. By setting the weight-average molecular weight at or below the upper limit, moldability tends to be improved. In this embodiment, two or more aromatic polycarbonate resins in this embodiment having different weight-average molecular weights may be mixed and used, and in this case, the weight-average molecular weight is the weight-average molecular weight of the mixture.

[0019] The glass transition temperature (Tg) of the aromatic polycarbonate resin in this embodiment used in this embodiment is preferably 160° C. or lower, more preferably 155° C. or lower, even more preferably 154° C. or lower, even more preferably 153° C. or lower, even more preferably 152° C. or lower, and even more preferably 151° C. or lower. The glass transition temperature (Tg) of the aromatic polycarbonate resin in this embodiment used in this embodiment is, for example, 140° C. or higher, and may further be 143° C. or higher, 145° C. or higher, 147° C. or higher, or 148° C. or higher. When the resin composition in this embodiment contains two or more types of aromatic polycarbonate resins, the glass transition temperature of the aromatic polycarbonate resins is the sum of the values ​​obtained by multiplying the glass transition temperature of each aromatic polycarbonate resin by its mass fraction.

[0020] For details of the aromatic polycarbonate resin, reference can be made to paragraphs 0011 to 0020 of JP-A-2012-144604 and paragraphs 0014 to 0035 of JP-A-2019-002023, the contents of which are incorporated herein by reference, as long as they do not deviate from the spirit of this embodiment.

[0021] The content of the aromatic polycarbonate resin in the film of this embodiment is preferably 85% by mass or more, more preferably 90% by mass or more, even more preferably 94% by mass or more, even more preferably 96% by mass or more, and even more preferably 97% by mass or more, based on 100% by mass of the film. The content of the aromatic polycarbonate resin in the film of this embodiment is preferably such that all components other than the triazine-based ultraviolet absorber and the specific wavelength absorbing dye (C) are aromatic polycarbonate resins, based on 100% by mass of the film. When the film of the present embodiment contains two or more types of aromatic polycarbonate resins, the total amount thereof preferably falls within the above range.

[0022] <Ultraviolet absorber having a triazine structure> The film of the present embodiment contains a triazine-based ultraviolet absorber. The use of a triazine-based ultraviolet absorber can reduce the light transmittance in the wavelength range of 380 to 420 nm and further improve heat resistance, particularly effectively suppressing color change after heating the film. Furthermore, the use of a triazine-based ultraviolet absorber tends to effectively suppress roll contamination during film production. The triazine-based ultraviolet absorber used in the present embodiment is preferably a triazine-based ultraviolet absorber having a maximum absorption wavelength of preferably 300 nm or more, more preferably 310 nm or more, even more preferably 330 nm or more, still more preferably 350 nm or more, and preferably 420 nm or less, more preferably 400 nm or less, still more preferably 390 nm or less, and still more preferably 380 nm or less.

[0023] The triazine-based ultraviolet absorber used in the present embodiment is not particularly limited in terms of type, but preferably contains a compound represented by formula (UV-1), more preferably contains a compound represented by formula (UV-2), and even more preferably contains a compound represented by formula (UV-3). [ka] (In formula (UV-1), R 1 is a hydrocarbon group having 1 to 10 carbon atoms or a group consisting of a combination of a hydrocarbon group having 1 to 10 carbon atoms and -O- and / or -C(=O)-, and R 2 ~R 4 are each independently a hydroxyl group, a hydrocarbon group having 1 to 10 carbon atoms, or a group consisting of a combination of a hydrocarbon group having 1 to 10 carbon atoms and -O- and / or -C(=O)-, n2 is an integer of 0 to 3, and n3 and n4 are each independently an integer of 0 to 4.

[0024] R 1is a hydrocarbon group having 1 to 10 carbon atoms or a group formed by combining a hydrocarbon group having 1 to 10 carbon atoms with -O- and / or -C(=O)-, more preferably an aliphatic hydrocarbon group having 1 to 10 carbon atoms or a group formed by combining an aliphatic hydrocarbon group having 1 to 10 carbon atoms with -O- and / or -C(=O)-, even more preferably an aliphatic hydrocarbon group having 1 to 10 carbon atoms, still more preferably a straight-chain aliphatic hydrocarbon group having 3 to 10 carbon atoms, and even more preferably a straight-chain alkyl group having 3 to 10 carbon atoms. R 1 The number of carbon atoms in the hydrocarbon group (preferably an aliphatic hydrocarbon group, more preferably an alkyl group) as the aryl group is preferably 2 or more, more preferably 3 or more, even more preferably 4 or more, and still more preferably 5 or more, and is preferably 9 or less, more preferably 8 or less, and even more preferably 7 or less.

[0025] R 2 ~R 4 are each independently a hydroxyl group, a hydrocarbon group having 1 to 10 carbon atoms, or a group consisting of a combination of a hydrocarbon group having 1 to 10 carbon atoms and -O- and / or -C(=O)-, and R 2 ~R 4 At least one of R is a hydroxyl group, 2 ~R 4 At least one of the others is preferably a hydrocarbon group having 1 to 10 carbon atoms, or a group formed by combining a hydrocarbon group having 1 to 10 carbon atoms with -O- and / or -C(=O)-. R 2 ~R 4 The hydrocarbon group having 1 to 10 carbon atoms as may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and is preferably a straight-chain aliphatic hydrocarbon group (preferably a straight-chain alkyl group) or a phenyl group. R 2 ~R 4The number of carbon atoms in the hydrocarbon group having 1 to 10 carbon atoms as the alkyl group is preferably 2 or more, more preferably 3 or more, even more preferably 4 or more, and even more preferably 5 or more, and is preferably 9 or less, more preferably 8 or less, and even more preferably 7 or less.

[0026] n2 is an integer of 0 to 3, preferably an integer of 0 or greater, more preferably an integer of 1 or greater, and is preferably an integer of 2 or less, more preferably an integer of 1 or less. n3 and n4 are each independently an integer of 0 to 4, preferably an integer of 1 or greater, more preferably an integer of 2 or greater, even more preferably an integer of 3 or greater, and are preferably an integer of 4 or less.

[0027] [ka] (In formula (UV-2), R 11 and R 31 , R 41 are each independently an aliphatic hydrocarbon group having 3 to 10 carbon atoms, and R 2 , R 32 , and ,R 42 are each independently a hydroxyl group, a hydrocarbon group having 1 to 10 carbon atoms, or a group consisting of a combination of a hydrocarbon group having 1 to 10 carbon atoms and -O- and / or -C(=O)-, and n2, n3-1, and n4-1 are each independently an integer of 0 to 3.

[0028] R 11 , R 31 and R 41 are each independently an aliphatic hydrocarbon group having 3 to 10 carbon atoms, and the number of carbon atoms in the aliphatic hydrocarbon group is preferably 4 or more, and even more preferably 5 or more, and is preferably 9 or less, more preferably 8 or less, and even more preferably 7 or less. The aliphatic hydrocarbon group is preferably a straight-chain aliphatic hydrocarbon group, and more preferably a straight-chain alkyl group. The aliphatic hydrocarbon group is preferably a straight-chain aliphatic hydrocarbon group, more preferably a straight-chain alkyl group, and is preferably a propyl group, a butyl group, a pentyl group, or a hexyl group, more preferably a butyl group, a pentyl group, or a hexyl group.

[0029] R 2 , R 32 , and ,R 42 are each independently a hydroxyl group, a hydrocarbon group having 1 to 10 carbon atoms, or a group formed by combining a hydrocarbon group having 1 to 10 carbon atoms with -O- and / or -C(=O)-. R 2 The preferred range of R in formula (UV-1) is 2 is the same as: R 32 , and ,R 42 The preferred ranges of are each independently a hydroxyl group and an alkyl group having 1 to 3 carbon atoms, and more preferably a hydroxyl group and a methyl group. n2 is an integer of 0 to 3, preferably 1 or 2, and more preferably 1. n3-1 and n4-1 each independently represent an integer of 0 to 3, preferably 1 or 2, and more preferably 2.

[0030] [ka] (In formula (UV-3), R 11 and R 31 , R 41 are each independently an aliphatic hydrocarbon group having 3 to 10 carbon atoms.

[0031] R 11 and R 31 , R 41are each independently an aliphatic hydrocarbon group having 3 to 10 carbon atoms, and the number of carbon atoms in the aliphatic hydrocarbon group is preferably 4 or more, and even more preferably 5 or more, and is preferably 9 or less, more preferably 8 or less, and even more preferably 7 or less. The aliphatic hydrocarbon group is preferably a straight-chain aliphatic hydrocarbon group, and more preferably a straight-chain alkyl group. The aliphatic hydrocarbon group is preferably a straight-chain aliphatic hydrocarbon group, more preferably a straight-chain alkyl group, and is preferably a propyl group, a butyl group, a pentyl group, or a hexyl group, more preferably a butyl group, a pentyl group, or a hexyl group.

[0032] Examples of triazine-based ultraviolet absorbers that can be used in this embodiment are listed below. It goes without saying that the ultraviolet absorbers that can be used in this embodiment are not limited to these. [ka]

[0033] In this embodiment, it is particularly preferable to use the following triazine-based ultraviolet absorbers. [ka]

[0034] The molecular weight of the triazine-based UV absorber used in this embodiment is preferably 400 or more, more preferably 500 or more, even more preferably 513 or more, even more preferably 550 or more, even more preferably 610 or more, even more preferably 650 or more, even more preferably 660 or more, and particularly preferably 680 or more. By setting the molecular weight of the triazine-based UV absorber to the above-mentioned lower limit or more, the triazine-based UV absorber becomes less likely to volatilize, and roll contamination can be more effectively suppressed. Furthermore, the molecular weight of the triazine-based UV absorber used in this embodiment is preferably 1,000 or less, more preferably 900 or less, and even more preferably 800 or less. By setting the molecular weight of the triazine-based UV absorber to the above-mentioned upper limit or less, compatibility with polycarbonate resins tends to be further improved. As a result, roll contamination during film formation tends to be effectively suppressed. When the film of the present embodiment contains two or more triazine-based ultraviolet absorbers, the molecular weight of the triazine-based ultraviolet absorber is the molecular weight of the triazine-based ultraviolet absorber with the smallest molecular weight.

[0035] The melting point of the triazine-based ultraviolet absorber used in this embodiment is preferably 180° C. or lower, more preferably 160° C. or lower, even more preferably 140° C. or lower, still more preferably 130° C. or lower, still more preferably 120° C. or lower, still more preferably 115° C. or lower, and may be 110° C. or lower. The lower limit of the melting point of the triazine-based ultraviolet absorber is preferably 90° C. or higher, more preferably 95° C. or higher, and still more preferably 100° C. or higher. When the film of the present embodiment contains two or more triazine-based ultraviolet absorbers, the melting points of the triazine-based ultraviolet absorbers are the sum (weighted average) of the values ​​obtained by multiplying the melting points of the respective triazine-based ultraviolet absorbers by the mass fractions of the respective triazine-based ultraviolet absorbers.

[0036] The content of the triazine-based UV absorber in the film of this embodiment is preferably 0.3 parts by mass or more, more preferably 0.5 parts by mass or more, even more preferably 1.0 parts by mass or more, even more preferably 1.5 parts by mass or more, and even more preferably 1.8 parts by mass or more, relative to 100 parts by mass of the aromatic polycarbonate resin. By setting the content at or above the lower limit, the film tends to have a lower light transmittance at a wavelength of 380 nm. Furthermore, the upper limit of the content of the triazine-based UV absorber is preferably 3.0 parts by mass or less, more preferably 2.5 parts by mass or less, even more preferably 2.4 parts by mass or less, even more preferably 2.3 parts by mass or less, and even more preferably 2.2 parts by mass or less, relative to 100 parts by mass of the aromatic polycarbonate resin. By setting the content at or below the upper limit, the color change of the film when heated tends to be more effectively suppressed.

[0037] The content of the triazine-based ultraviolet absorber in the film of this embodiment is preferably 0.3% by mass or more, more preferably 0.5% by mass or more, even more preferably 1.0% by mass or more, even more preferably 1.2% by mass or more, and even more preferably 1.5% by mass or more, relative to 100% by mass of the film. By setting the content at or above the lower limit, the light transmittance of the film at a wavelength of 380 nm tends to be reduced. Furthermore, the upper limit of the content of the triazine-based ultraviolet absorber is preferably 3.0% by mass or less, more preferably 2.5% by mass or less, even more preferably 2.4% by mass or less, even more preferably 2.3% by mass or less, and even more preferably 2.2% by mass or less, relative to 100% by mass of the film. By setting the content at or below the upper limit, color change of the film when heated tends to be more effectively suppressed. The film of the present embodiment may contain only one type of triazine-based ultraviolet absorber, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0038] <Specific wavelength absorption dye with maximum absorption wavelength between 400 and 440 nm> In this embodiment, a specific wavelength absorbing dye (specific wavelength absorbing dye (C)) having a maximum absorption wavelength in the wavelength range of 400 to 440 nm is used. By using the specific wavelength absorbing dye (C), it is possible to fully exert the light absorbing function in the wavelength range of 400 to 440 nm even when a small amount is added. Furthermore, since the blending amount can be reduced, color change when the film is heated can be effectively suppressed. In particular, the inventors have conducted studies and found that the above-mentioned effect is significantly exerted when the specific wavelength absorbing dye (C) is used.

[0039] A specific wavelength absorbing dye is a dye that selectively absorbs light in a specific wavelength region, and specific wavelength region dyes for various wavelength regions are commercially available from Nagase Vita Co., Ltd., Yamada Chemical Industry Co., Ltd., Yamamoto Kasei Co., Ltd., Orient Chemical Industry Co., Ltd., and others. The specific wavelength absorption dye (C) used in the present embodiment has a maximum absorption wavelength between 400 and 440 nm, and the peak of the maximum absorption wavelength is preferably in a wavelength range of 410 nm or more, more preferably in a wavelength range of 415 nm or more, and is preferably in a wavelength range of 430 nm or less, and more preferably in a wavelength range of 425 nm or less.

[0040] Examples of the specific wavelength absorbing dye (C) used in this embodiment are shown below. (1) A dye that has a maximum absorption wavelength of 400 to 440 nm in its absorption spectrum. (2) A dye having an absorption spectrum with a half-width of 50 nm or less in the wavelength range of 400 to 440 nm. The half-width is preferably 30 nm or less, and practically 10 nm or more. The absorption spectrum is (3) A porphyrin dye having a maximum absorption wavelength in the wavelength range of 400 to 440 nm. It is empirically known that any of these dyes can be used as a specific wavelength absorbing dye (C). (4) A dye that satisfies two or three of the above (1) to (3)

[0041] The absorption spectrum of the specific wavelength absorbing dye (C) is a value measured by dissolving the dye in chloroform solvent and using a spectrophotometer. The half-value width is a value calculated from the light transmittance curve measured according to the above method. A dye that satisfies the above (1) to (3) tends to be less likely to discolor at the molding temperature of the aromatic polycarbonate resin, and tends to be able to effectively suppress color change.

[0042] The specific wavelength absorbing dye (C) may be either a dye or a pigment, but is usually a pigment.

[0043] When the resin composition of this embodiment contains the specific wavelength absorbing dye (C), the content thereof is preferably 2 ppm by mass or more, more preferably 4 ppm by mass or more, even more preferably 6 ppm by mass or more, even more preferably 8 ppm by mass or more, and even more preferably 10 ppm by mass or more, relative to 100 parts by mass of the aromatic polycarbonate resin, and is preferably 50 ppm by mass or less, more preferably 40 ppm by mass or less, even more preferably 30 ppm by mass or less, even more preferably 20 ppm by mass or less, and even more preferably 15 ppm by mass or less. By setting the content at or above the lower limit, light with a wavelength of 400 to 440 nm tends to be effectively blocked. On the other hand, by setting the content at or below the upper limit, light other than the target wavelength tends to be effectively blocked. The resin composition of the present embodiment may contain only one specific wavelength absorbing dye (C), or may contain two or more specific wavelength absorbing dyes (C). When two or more specific wavelength absorbing dyes (C) are contained, the total amount is preferably in the above range.

[0044] In the film of this embodiment, the mass ratio of the triazine-based ultraviolet absorber to the specific wavelength absorbing dye (C) (triazine-based ultraviolet absorber / specific wavelength absorbing dye (C)) is preferably 0.10 or more, more preferably 0.12 or more, and even more preferably 0.14 or more; preferably 0.30 or less, more preferably 0.27 or less, even more preferably 0.25 or less, still more preferably 0.24 or less, even more preferably 0.20 or less, and even more preferably 0.18 or less. By setting the content at or above the lower limit, light in the ultraviolet region tends to be effectively blocked, while by setting the content at or below the upper limit, roll contamination during molding tends to be effectively suppressed and improved.

[0045] <Other ingredients> The film of the present embodiment may or may not contain components other than the aromatic polycarbonate resin, the triazine-based ultraviolet absorber, and the specific wavelength absorbing dye (C). Examples of other components include antioxidants, release agents, heat stabilizers, flame retardants, flame retardant assistants, colorants other than those mentioned above, antistatic agents, fluorescent brighteners, antifogging agents, flow improvers, plasticizers, dispersants, antibacterial agents, antiblocking agents, impact improvers, sliding improvers, hue improvers, and acid trapping agents. In addition, the film of this embodiment can be blended with additives described in paragraphs 0047 to 0103 of International Publication No. 2021 / 241471 within the scope of the present invention, the contents of which are incorporated herein by reference. When other components are contained, the total content thereof is preferably 0.001 to 3% by mass of the film, more preferably 2% by mass or less, even more preferably 1% by mass or less, even more preferably 0.5% by mass or less, and even more preferably 0.1% by mass or less, and may be less than 0.01% by mass. The other component may be contained in only one kind or in two or more kinds. When two or more kinds of other components are contained, it is preferable that the total amount is in the above range.

[0046] The film of the present embodiment may be configured to be substantially free of triazine-based ultraviolet absorbers other than the compound represented by formula (UV-3). "Substantially free" means that the content of triazine-based ultraviolet absorbers other than the compound represented by formula (UV-3) contained in the film is less than 1% by mass, and preferably less than 0.1% by mass, of the content of the compound represented by formula (UV-3) contained in the film.

[0047] The film of the present embodiment may or may not contain an ultraviolet absorber other than the triazine-based ultraviolet absorber. In a first aspect of this embodiment, the film is substantially free of ultraviolet absorbers other than triazine-based ultraviolet absorbers. "Substantially free" means that the content of ultraviolet absorbers other than triazine-based ultraviolet absorbers is less than 1% by mass, preferably less than 0.1% by mass, of the content of triazine-based ultraviolet absorbers contained in the film. In a second aspect of this embodiment, the film is configured to be substantially free of a benzotriazole-based ultraviolet absorber. "Substantially free" means that the content of the benzotriazole-based ultraviolet absorber contained in the film is less than 1% by mass, preferably less than 0.1% by mass, of the content of the triazine-based ultraviolet absorber contained in the film. In a third aspect of this embodiment, the film contains both a triazine-based UV absorber and a benzotriazole-based UV absorber. In this third aspect, the benzotriazole-based UV absorber is preferably contained in an amount of 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and preferably 6.5 parts by mass or less, more preferably 7 parts by mass or less, and even more preferably 8 parts by mass or less, per 1 part by mass of the triazine-based UV absorber. In this third aspect, only one type of benzotriazole-based UV absorber may be used, or two or more types may be used. When two or more types are used, the total amount is preferably within the above range. For benzotriazole-based UV absorbers, the description in paragraphs 0023 to 0025 of JP 2023-025384 A can be referred to, and the contents thereof are incorporated herein by reference.

[0048] The film of the present embodiment may or may not contain a visible light absorber other than the triazine-based ultraviolet absorber and the specific wavelength absorbing dye (C). The film of this embodiment may also be configured to be substantially free of visible light absorbers other than the triazine-based ultraviolet absorber and the specific wavelength absorbing dye (C). Specifically, the content of the triazine-based ultraviolet absorber and the visible light absorber other than the specific wavelength absorbing dye (C) is preferably less than 0.01 mass %, more preferably less than 0.001 mass %, of the total content of the triazine-based ultraviolet absorber and the specific wavelength absorbing dye (C) contained in this embodiment. The film of the present embodiment may also be configured to be substantially free of a benzotriazole-based ultraviolet absorber. Specifically, the content of the benzotriazole-based ultraviolet absorber is preferably less than 0.01 mass %, more preferably less than 0.001 mass %, of the total content of the triazine-based ultraviolet absorber and the specific wavelength absorbing dye (C) contained in the present embodiment. The film of the present embodiment may also be configured to be substantially free of black pigment (and further, black colorant). Specifically, the content of the black pigment is preferably less than 0.01 mass %, more preferably less than 0.001 mass %, of the total content of the triazine-based ultraviolet absorber and the specific wavelength absorbing dye (C) contained in the present embodiment. The film of the present embodiment may also be configured to be substantially free of a yellow dye (or a yellow colorant). Specifically, the content of the yellow dye is preferably less than 0.01 mass %, more preferably less than 0.001 mass %, of the total content of the triazine-based ultraviolet absorber and the specific wavelength-absorbing dye (C) contained in the present embodiment.

[0049] <Film thickness> The film of this embodiment preferably has a thickness of 200 to 500 μm. By setting the thickness of the film to the lower limit or more, the light transmittance of the film at wavelengths of 420 nm or less tends to be reduced. By setting the thickness of the film to the upper limit or less, the heat bending processability tends to be improved. The thickness of the film is preferably 250 μm or more, more preferably 280 μm or more, and is preferably 550 μm or less, more preferably 510 μm or less, even more preferably less than 500 μm, even more preferably 450 μm or less, even more preferably 400 μm or less, and even more preferably 350 μm or less.

[0050] <Film light transmittance> The film of this embodiment preferably has low light transmittance in the range of 380 nm to 420 nm. The light transmittance of the film of this embodiment at a wavelength of 420 nm is preferably less than 15%. Although there is no particular lower limit for the light transmittance of the film of this embodiment at a wavelength of 420 nm, a value of 0.1% or more is practical, and even a value of 1% or more is sufficient to satisfy the required performance. The light transmittance of the film of this embodiment at a wavelength of 380 nm is preferably 3% or less, more preferably 2% or less, even more preferably 1% or less, even more preferably 0.6% or less, and even more preferably less than 0.1%. There is no particular lower limit for the light transmittance of the film of this embodiment at a wavelength of 380 nm, but a value greater than 0% is practical. A film satisfying the above-mentioned light transmittance can be achieved by blending a triazine-based ultraviolet absorber and a specific wavelength absorbing dye (C) as the ultraviolet absorber and dye into an aromatic polycarbonate resin.

[0051] <Wound body> The film of this embodiment can be wound around a core material to form a roll.

[0052] <Polarizing sheet> The film of this embodiment is preferably used as a polarizing sheet. In this embodiment, the polarizing sheet includes a film and a polarizing film. More specifically, the polarizing sheet is a sheet in which the film of this embodiment, a polarizing film, and a polarizing film substrate are laminated in this order. That is, the film of this embodiment is preferably used as at least one of the polarizing film substrates of the polarizing sheet. The polarizing film substrate is usually attached to the polarizing film via an adhesive. In this embodiment, one of the polarizing film substrates of the polarizing sheet may be the film of this embodiment or another polarizing film substrate. The other polarizing film substrate of the polarizing sheet may be a polarizing film substrate of a known polarizing sheet, and may be the same as the film of this embodiment. Known polarizing films can be used, and examples thereof include polyvinyl alcohol (PVA) films with iodine or a dichroic organic dye adsorbed or impregnated therein. The adhesive used to bond the film polarizing film substrate and the polarizing film of this embodiment can be a known adhesive, and examples thereof include acrylic adhesives, urethane adhesives, epoxy adhesives, silicone adhesives, polyvinyl alcohol adhesives, etc. Among these, urethane adhesives are preferred. The thickness of the adhesive is usually 1 μm or more and usually 30 μm or less. The polarizing sheet of this embodiment may further include a masking film or the like on the outer side of the polarizing film substrate.

[0053] In addition, in this embodiment, the polarizing sheet of this embodiment is preferably used for a heat-bent molded article obtained by heat bending processing, and is particularly preferably used as a polarizing film substrate for a polarizing sheet. When the film of this embodiment is used in a polarizing sheet, it may be provided on either side of a polarizing film, or on both sides. In the first mode, the film of this embodiment is disposed so that it is positioned on the concave side of the polarizing film after heat bending, for example, on the side of the polarizing film substrate 4 in FIG. In the second mode, the film of this embodiment is disposed so that it is positioned on the convex side of the polarizing film after heat bending, for example, on the side of the polarizing film substrate 3 in FIG. In the third embodiment, the film of this embodiment is positioned on both sides of the polarizing film, for example, both of the polarizing film substrates 3 and 4 in FIG. 1 are the film of this embodiment. In FIG. 1, the lens 1, polarizing film 2, and polarizing film substrates 3 and 4 of the polarizing sheet are bent, but it goes without saying that this embodiment also includes a case where they are not bent.

[0054] In this embodiment, the polarizing sheet is preferably used as a polarizing sheet for use in liquid crystal display devices, polarizing lenses (sunglasses lenses, ski goggles, prescription eyeglass lenses, camera viewfinder lenses), covers for various instruments, automobile glass, train glass, polarizing sheets for in-vehicle display panels and electronic device housings, etc., in-vehicle inner mirrors, silver mirrors for helmets, etc. In particular, the polarizing sheet of this embodiment is preferably used for sunglasses. [Example]

[0055] The present invention will be explained in more detail below with reference to examples. The materials, amounts used, ratios, processing details, processing procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. If the measuring instruments used in the examples are difficult to obtain due to discontinuation or the like, measurements can be made using other instruments with equivalent performance.

[0056] 1. Raw materials A1: Bisphenol A polycarbonate sheet resin, manufactured by Mitsubishi Gas Chemical Company, Inc., S-3000 B1: Triazine-based UV absorber, LA-F70, manufactured by ADEKA [ka] B2: Non-triazine UV absorber, LA-31, manufactured by ADEKA [ka]

[0057] C1: Specific wavelength absorption dye (C), maximum absorption wavelength is 420 nm, FDB-001, Yamada Chemical Co., Ltd. D1: Yellow dye, 8000, manufactured by Arimoto Chemical Industry Co., Ltd. D2: Yellow dye, 8005, manufactured by Arimoto Chemical Industry Co., Ltd.

[0058] Example 1, Comparative Examples 1 to 7 <Film manufacturing> A polycarbonate resin film was produced by the following method. The components listed in Table 1 were weighed out to the amounts listed in Table 1 (Table 1 shows the amounts in parts by mass, except for the specific wavelength absorbing dye (C) in ppm by mass). After mixing for 15 minutes in a tumbler, the mixture was extruded into a molten state using a T-die melt extruder consisting of a vented twin-screw segment extruder (Toyo Seiki Co., Ltd., "2D30W2") with a barrel diameter of 25 mm and a screw length / distance ratio of 30 mm at a throughput of 8 kg / h and a screw rotation speed of 100 rpm. The extruded material was then cooled and solidified using only the first roll of a film / sheet take-up device (Toyo Seiki Co., Ltd., "FT3W20") to produce a polycarbonate resin film. The cylinder / die head temperature was 280°C, and the roll temperature was 130°C. The final film thickness was adjusted to the thickness shown in Table 1 by changing the roll speed of the first roll.

[0059] <Light transmittance> The light transmittance of the obtained film at wavelengths of 420 nm and 380 nm was measured. Specifically, the light transmittance (unit: %) was measured using a spectrophotometer at a scan speed of 300 nm / min and a sampling interval of 1 nm. The measurement was carried out using a spectrophotometer U-4100 (manufactured by Hitachi High-Technologies Corporation). The light transmittance at 420 nm was evaluated according to the following classifications. <<Transmittance at 420 nm>> A: Less than 15% B: 1% to less than 50% C: 50% or more

[0060] <<Light transmittance of polarizing sheet>> The light transmittance at a wavelength of 420 nm of the resulting multilayer structure consisting of two overlapping films was measured. The results are shown in Table 1.

[0061] <Roll stains> The rolls used in the film production were visually inspected for contamination by five experts, who made a majority decision based on the following criteria: A: No dirt on the roll was found B: Roll contamination was confirmed

[0062] <Color change> The resulting multilayer body having two films stacked on top of each other was measured for hue, which was evaluated as a color change (ΔE) relative to the multilayer body using the film of Comparative Example 1. The hue was measured in accordance with JIS Z 8722 using a spectrophotometer under illumination and receiving light conditions of di:0° post-spectroscopic method. The spectrophotometer used was a "V-760" manufactured by JASCO Corporation.

[0063] <Heat resistance> The heat resistance of the obtained film was evaluated. Specifically, the multilayer body was heated at 120° C. for 100 hours, and the color change before and after heating was measured. The color change was evaluated as ΔE before and after heating. ΔE was measured using a spectrophotometer in accordance with JIS Z 8722 under illumination and light receiving conditions of di:0° post-spectrophotometric method. The spectrophotometer used was the SD-7000 manufactured by Nippon Denshoku Industries Co., Ltd.

[0064] [Table 1]

[0065] In Table 1 above, the transmittance at 420 nm, the transmittance at 380 nm, the heat resistance and the roll contamination are evaluations of the film alone, and the color change, the transmittance at 420 nm and the multilayer body of two films stacked together are evaluations.

[0066] Among the values ​​shown in the "Transmittance at 380 nm" column, "<0.1" indicates that the transmittance of light at a wavelength of 380 nm was less than 0.1%. It was found that the film of this embodiment can sufficiently block light rays with wavelengths of 380 nm to 420 nm. Furthermore, it was found that the film of this embodiment can also block light rays with a wavelength of 420 nm when made into a multilayer body. The film of this embodiment was able to effectively suppress roll contamination during production. Although the film of this embodiment contains an ultraviolet absorber and a dye, color change was small when it was made into a multilayer body. Although the film of this embodiment contains an ultraviolet absorber and a dye, when it is made into a multilayer body, the heat resistance (color change) is small. Comparative Example 6 is an example in which an ultraviolet absorber other than a triazine-based ultraviolet absorber was used, and the ultraviolet absorber was blended to a level where the light transmittance at a wavelength of 420 nm satisfied the evaluation "A." As a result, the heat resistance was poor and roll contamination occurred. On the other hand, in Comparative Example 7, the amount of the ultraviolet absorber in Comparative Example 6 was changed to the same amount as in Example 1, and the light transmittance at a wavelength of 420 nm was high.

[0067] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention. [Explanation of symbols]

[0068] 1 lens 2. Polarizing film 3. Polarizing film substrate 4. Polarizing film substrate

Claims

1. A film comprising an aromatic polycarbonate resin, an ultraviolet absorber having a triazine structure, and a specific wavelength absorbing dye having a maximum absorption wavelength in the wavelength range of 400 to 440 nm.

2. The film of claim 1, wherein the thickness of the film is 200 to 500 μm.

3. 3. The film according to claim 1, wherein the concentration of the specific wavelength absorbing dye is 2 to 50 ppm by mass relative to 100 parts by mass of the polycarbonate resin.

4. The film according to any one of claims 1 to 3, wherein the ultraviolet absorber having a triazine structure includes a compound represented by formula (UV-1): 【Chemistry 1】 (In formula (UV-1), R １ is a hydrocarbon group having 1 to 10 carbon atoms or a group consisting of a combination of a hydrocarbon group having 1 to 10 carbon atoms and —O— and / or —C(═O)—, and R ２ ~R ４ are each independently a hydroxyl group, a hydrocarbon group having 1 to 10 carbon atoms, or a group formed by combining a hydrocarbon group having 1 to 10 carbon atoms with —O— and / or —C(═O)—, and n2 is an integer of 0 to 3, n3 and n4 each independently represent an integer of 0 to 4.

5. 5. The film according to claim 4, wherein n3 and n4 each independently represent an integer of 1 to 4.

6. The film according to any one of claims 1 to 3, wherein the ultraviolet absorber having a triazine structure includes a compound represented by formula (UV-2): 【Chemistry 2】 (In formula (UV-2), R １１ and R ３１ , R ４１ are each independently an aliphatic hydrocarbon group having 3 to 10 carbon atoms, and R ２ , R ３２ , and R ４２ are each independently a hydroxyl group, a hydrocarbon group having 1 to 10 carbon atoms, or a group consisting of a combination of a hydrocarbon group having 1 to 10 carbon atoms and -O- and / or -C(=O)-, and n2, n3-1, and n4-1 are each independently an integer of 0 to 3.

7. The film according to any one of claims 1 to 3, wherein the ultraviolet absorber having a triazine structure includes a compound represented by formula (UV-3): 【Transformation 3】 (In formula (UV-3), R １１ and R ３１ , R ４１ are each independently an aliphatic hydrocarbon group having 3 to 10 carbon atoms.

8. The film according to any one of claims 1 to 7, wherein the film has a light transmittance of less than 15% at a wavelength of 420 nm.

9. The film according to any one of claims 1 to 8, wherein the film has a light transmittance of less than 15% at a wavelength of 380 nm.

10. A polarizing sheet comprising the film according to any one of claims 1 to 9 and a polarizing film.

11. A heat-bent product of the polarizing sheet according to claim 10.

12. Sunglasses comprising the polarizing sheet according to claim 10.

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