Resin composition, film, polarizing sheet, and sunglasses

Abstract

To provide a resin composition capable of yielding a film that has superior transparency and can prevent roll contamination effectively during film manufacturing, as well as to provide a film, a polarizing sheet, and sunglasses.SOLUTION: A resin composition comprises a polyamide resin containing an alicyclic diamine unit and an aliphatic dicarboxylic acid unit having 7 to 20 carbon atoms, and a release agent, wherein the release agent contains a fatty acid ester and / or a fatty acid amide, and the fatty acid constituting the fatty acid ester and / or the fatty acid amide is a fatty acid having 7 to 30 carbon atoms.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a resin composition, a film, a polarizing sheet, and sunglasses, and in particular to a resin composition containing a polyamide resin as a main component. [Background technology]

[0002] Polyamide resins have excellent mechanical properties such as rigidity and strength, as well as excellent heat resistance, and are therefore used in a wide range of applications, including electrical and electronic applications, automobiles, machinery, and building materials (Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-129271 A [Patent Document 2] JP 2013-001906 A [Patent Document 3] JP 2012-131977 A Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, polyamide resins are used in a wide variety of fields, but they are generally poor in transparency and have not been used in applications where transparency is required. Under such circumstances, the present inventors have investigated the use of polyamide resins for transparent applications such as protective films for polarizing films, etc. However, when polyamide resins are molded into a film, there are cases in which the rolls are stained during the production of the film. The present invention aims to solve such problems, and to provide a resin composition capable of providing a film that has excellent transparency and can effectively suppress roll contamination during film production, as well as a film, a polarizing sheet, and sunglasses. [Means for solving the problem]

[0005] In view of the above problems, the present inventors have conducted research and found that the above problems can be solved by blending a release agent which is an ester or amide of a fatty acid having 7 to 30 carbon atoms with a specific polyamide resin. Specifically, the above problems were solved by the following means. <1> A polyamide resin containing an alicyclic diamine unit and an aliphatic dicarboxylic acid unit having 7 to 20 carbon atoms, and a release agent, the release agent comprises a fatty acid ester and / or a fatty acid amide; The resin composition, wherein the fatty acid constituting the fatty acid ester and / or fatty acid amide is a fatty acid having 7 to 30 carbon atoms. <2> The aliphatic dicarboxylic acid unit having 7 to 20 carbon atoms includes a sebacic acid unit and / or a dodecanedioic acid unit. <1> The resin composition according to claim 1. <3> The alicyclic diamine constituting the alicyclic diamine unit contains two substituted or unsubstituted cyclohexane rings. <1> or <2> The resin composition according to claim 1. <4> The alicyclic diamine unit includes a unit represented by formula (PA-1): <1> or <2> The resin composition according to claim 1. [ka] (In formula (PA-1), R 1 are each independently an alkyl group having 1 to 5 carbon atoms, and each n1 is independently an integer of 0 to 3. * is a bonding site with another unit or a terminal group. <5> The content of the release agent in the resin composition is 0.001 to 10% by mass. <1> ~ <4> 10. The resin composition according to claim 9 . <6> the aliphatic dicarboxylic acid unit having 7 to 20 carbon atoms contains a sebacic acid unit and / or a dodecanedioic acid unit, The alicyclic diamine unit includes a unit represented by formula (PA-1), The content of the release agent in the resin composition is 0.001 to 10% by mass. <1> ~ <5> 10. The resin composition according to claim 9 . [ka] (In formula (PA-1), R 1 are each independently an alkyl group having 1 to 5 carbon atoms, and each n1 is independently an integer of 0 to 3. * is a bonding site with another unit or a terminal group. <7> The polyamide resin is an amorphous resin. <1> ~ <6> 10. The resin composition according to claim 9 . <8> When the resin composition is molded into a film having a thickness of 300 μm, the haze is 3.0% or less. <1> ~ <7> 10. The resin composition according to claim 9 . <9> When the resin composition is molded into a film having a thickness of 300 μm, the total light transmittance is 80% or more. <1> ~ <8> 10. The resin composition according to claim 9 . <10> For use as a protective film for polarizing sheets. <1> ~ <9> 10. The resin composition according to claim 9 . <11> <1> ~ <10> 2. A film formed from the resin composition according to claim 1. <12> <11> A polarizing sheet comprising the film according to claim 1 and a polarizing film. <13> <12> Sunglasses comprising the polarizing sheet according to claim 1. Effect of the Invention

[0006] It has become possible to provide a resin composition capable of providing a film that is excellent in transparency and can effectively suppress roll contamination during the production of the film, as well as a film, a polarizing sheet, and sunglasses. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a schematic diagram for explaining an example of a layer structure of the hot-bent molded body of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of 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 the present embodiment. In this specification, the word "to" is used to mean that the numerical values ​​before and after the word "to" are included as the upper and lower limits. In addition, any combination of the upper and lower limit values ​​of the numerical values ​​in this specification is an example of this embodiment. In this specification, various physical properties and characteristic values ​​are those at 23° C. unless otherwise specified. In the description of groups (atomic groups) in this specification, when the description does not indicate whether the group is substituted or unsubstituted, the description also includes groups (atomic groups) that have a substituent as well as groups (atomic groups) that have no substituent. For example, the term "alkyl group" includes not only alkyl groups that have no substituent (unsubstituted alkyl groups), but also alkyl groups that have a substituent (substituted alkyl groups). In this specification, when the description does not indicate whether the group is substituted or unsubstituted, the description is preferably unsubstituted. Examples of the substituent in this specification are preferably a halogen atom, a cyano group, a nitro group, a hydroxy group, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a heterocyclic group, a heterocyclic oxy group, an alkenyl group, an alkylsulfanyl group, an arylsulfanyl group, an acyl group, or an amino group, more preferably a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an alkenyl group, or an acyl group, even more preferably an alkyl group, an aryl group, an aryloxy group, or an alkenyl group, and even more preferably an alkyl group. The formula weight of these substituents is preferably 15 or more, and preferably 200 or less. The formula weight is, for example, the formula weight of a methyl group (-CH 3 ) is 15. These substituents may further have a substituent, but it is preferable that they have no substituent.

[0009] The term "film" as used herein refers to a generally flat molded body having a small thickness relative to its length and width, and is intended to include a sheet. The term "film" as used herein may be either a single layer or a multilayer, with a single layer being preferred. If the measurement methods, etc. described in the standards shown in this specification vary from year to year, they will be based on the standards as of January 1, 2023, unless otherwise stated. Figure 1 may not be to scale and may not correspond to reality.

[0010] The resin composition of the present embodiment comprises a polyamide resin containing an alicyclic diamine unit and an aliphatic dicarboxylic acid unit having 7 to 20 carbon atoms, and a release agent, the release agent containing a fatty acid ester and / or a fatty acid amide, and the fatty acid constituting the fatty acid ester and / or fatty acid amide is a fatty acid having 7 to 30 carbon atoms. By adopting such a configuration, a resin composition capable of providing a film having excellent transparency and capable of effectively suppressing roll staining during the production of the film can be obtained. It is presumed that roll staining is caused, for example, by the polyamide resin remaining in the die during extrusion molding and adhering to the metal wall surface, which causes the polyamide resin to decompose. The inventors of the present invention have conducted research and found that by using a release agent containing an ester bond or an amide bond and derived from a fatty acid having 7 to 30 carbon atoms as a release agent, it is possible to effectively suppress the polyamide resin from remaining in the die, and as a result, it is possible to effectively suppress roll staining. It is presumed that this is because the inclusion of an ester bond or an amide bond allows for moderate compatibility with the polyamide resin, and the inclusion of a release agent derived from a fatty acid having 7 to 30 carbon atoms makes it easier for the aliphatic group of the release agent to be present on the metal wall surface side in the die in the resin composition. It is presumed that the use of a release agent having such characteristics allows for a resin composition capable of providing a film that can effectively suppress roll staining during the production of the film while maintaining transparency. The details of this embodiment will be described below.

[0011] <Polyamide resin containing alicyclic diamine units and aliphatic dicarboxylic acid units having 7 to 20 carbon atoms> The resin composition of the present embodiment contains a polyamide resin containing an alicyclic diamine unit and an aliphatic dicarboxylic acid unit having 7 to 20 carbon atoms (sometimes referred to as "polyamide resin (A)" in this specification). The alicyclic structure of the polyamide resin (A) improves the transparency of the polyamide resin itself, and the aliphatic dicarboxylic acid unit having 7 to 20 carbon atoms increases the compatibility with the release agent, thereby improving the transparency of the resulting resin composition.

[0012] In this embodiment, the alicyclic diamine constituting the alicyclic diamine unit is preferably a diamine containing a 5-membered alicyclic ring and / or a 6-membered alicyclic ring. The 5-membered ring and / or the 6-membered ring may or may not have a substituent. In addition, the alicyclic diamine is preferably composed only of an aliphatic hydrocarbon group containing an alicyclic structure, except for the terminal amino group. The alicyclic diamine unit more preferably contains 2 to 3 or more substituted or unsubstituted cyclohexane rings, and further preferably contains 2 substituted or unsubstituted cyclohexane rings, in one unit. The alicyclic diamine unit preferably does not contain a carbon-carbon double bond or a carbon-carbon triple bond. The molecular weight of the alicyclic diamine constituting the alicyclic diamine unit is preferably 195 or more, more preferably 200 or more, and is preferably 500 or less, more preferably 400 or less, and even more preferably 300 or less.

[0013] In this embodiment, it is more preferable that the alicyclic diamine unit contains at least one type represented by formula (PA-0). [ka] (In formula (PA-0), R is each independently a substituent, and n is each independently an integer of 0 to 5. L is a single bond or a divalent linking group. * is a bonding site with another unit or a terminal group.) In formula (PA-0), each R is independently a substituent, and is preferably an aliphatic group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, even more preferably a linear or branched alkyl group having 1 to 6 carbon atoms, still more preferably a methyl group, an ethyl group or a propyl group, and even more preferably a methyl group. In formula (PA-0), each n is independently an integer of 0 to 5, preferably an integer of 1 or greater, and more preferably an integer of 4 or less, more preferably an integer of 3 or less, even more preferably an integer of 2 or less, and still more preferably an integer of 1 or less. In formula (PA-0), L is a single bond or a divalent linking group, more preferably a single bond or a divalent aliphatic hydrocarbon group, more preferably a single bond or a divalent alkylene group, even more preferably a single bond or an alkylene group having 1 to 3 carbon atoms, still more preferably a single bond, a methylene group, an ethylene group, or an isopropylene group, and even more preferably a methylene group. * is a bonding site with other units or terminal groups, i.e., usually bonding with -C(=O)- to form an amide bond together with NH in formula (PA-0), bonding with a hydrogen atom to form a terminal amino group together with NH in formula (PA-0), or bonding with a terminal group.

[0014] In this embodiment, the alicyclic diamine unit is more preferably represented by formula (PA-1). [ka] (In formula (PA-1), R 1 are each independently an alkyl group having 1 to 5 carbon atoms, and each n1 is independently an integer of 0 to 3. * is a bonding site with another unit or a terminal group.

[0015] In formula (PA-1), R 1is an alkyl group having 1 to 5 carbon atoms, preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a methyl group, an ethyl group or a propyl group, and even more preferably a methyl group. In formula (PA-1), n1 is an integer of 0 to 3, preferably an integer of 1 or more, and more preferably an integer of 2 or less, with 1 being more preferable.

[0016] Specific examples of alicyclic diamines include 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis(4-aminocyclohexyl)methane, bis(4-amino-3-methylcyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, 2,2-bis(4-amino-3-methylcyclohexyl)propane, bis(aminomethyl)decalin, and bis(aminomethyl)tricyclodecane.

[0017] The polyamide resin (A) contains alicyclic diamine units in a proportion of preferably 75 mol % or more, more preferably 80 mol % or more, even more preferably 85 mol % or more, still more preferably 90 mol % or more, still more preferably 95 mol % or more, particularly preferably 99 mol % or more, and 100 mol % or less of the diamine units constituting the polyamide resin (A). The alicyclic diamine units may be one type or a combination of two or more types.

[0018] Examples of diamines other than alicyclic diamines that can be used as the raw diamine component of the polyamide resin (A) include aliphatic diamines such as tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethyl-hexamethylenediamine, and 2,4,4-trimethylhexamethylenediamine, and diamines having an aromatic ring such as xylylenediamine, bis(4-aminophenyl)ether, paraphenylenediamine, and bis(aminomethyl)naphthalene, and these can be used alone or in combination of two or more.

[0019] On the other hand, in this embodiment, the aliphatic dicarboxylic acid having 7 to 20 carbon atoms constituting the aliphatic dicarboxylic acid unit having 7 to 20 carbon atoms is preferably a linear or branched aliphatic dicarboxylic acid having 7 to 20 carbon atoms, more preferably a linear aliphatic dicarboxylic acid having 7 to 20 carbon atoms, and even more preferably an α,ω-linear aliphatic dicarboxylic acid having 7 to 20 carbon atoms. The number of carbon atoms constituting the linear aliphatic dicarboxylic acid having 7 to 20 carbon atoms is preferably 8 or more, more preferably 9 or more, and even more preferably 10 or more, and is preferably 18 or less, more preferably 16 or less, even more preferably 14 or less, even more preferably 13 or less, and even more preferably 12 or less. The aliphatic dicarboxylic acid having 7 to 20 carbon atoms is preferably HOOC-(CH 2 ) n It is preferably represented by —COOH, where n is an integer of 5 to 18. The aliphatic dicarboxylic acid unit having 7 to 20 carbon atoms that can be used in the present embodiment preferably contains at least one of a sebacic acid unit, an undecanedioic acid unit, and a dodecanedioic acid unit, and more preferably contains a sebacic acid unit and / or a dodecanedioic acid unit.

[0020] The polyamide resin (A) contains aliphatic dicarboxylic acid units having 7 to 20 carbon atoms in a proportion of preferably 75 mol % or more, more preferably 80 mol % or more, even more preferably 85 mol % or more, still more preferably 90 mol % or more, still more preferably 95 mol % or more, particularly preferably 99 mol % or more, and 100 mol % or less of the dicarboxylic acid units constituting the polyamide resin. The aliphatic dicarboxylic acid units having 7 to 20 carbon atoms may be one type or a combination of two or more types.

[0021] Examples of dicarboxylic acid components other than the aliphatic dicarboxylic acids having 7 to 20 carbon atoms include phthalic acid compounds such as isophthalic acid, terephthalic acid, and orthophthalic acid, and isomers of naphthalenedicarboxylic acids such as 1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid. These can be used alone or in combination of two or more kinds.

[0022] The polyamide resin (A) used in the present embodiment may further contain an aminocarboxylic acid unit, which tends to improve the color of the molded product. The type of amino carboxylic acid constituting the amino carboxylic acid unit is not particularly limited, and any known amino carboxylic acid can be used. The amino carboxylic acid is preferably composed only of aliphatic hydrocarbon groups, except for the terminal amino groups and carboxylic acid groups. The molecular weight of the amino carboxylic acid constituting the amino carboxylic acid unit is preferably 180 or more, more preferably 190 or more, and is preferably 400 or less, more preferably 300 or less, and even more preferably 250 or less.

[0023] The amino carboxylic acid constituting the amino carboxylic acid unit is preferably represented by formula (PA-2). [ka] (In formula (PA-2), n is an integer of 5 to 20.) In formula (PA-2), n is an integer from 5 to 20, preferably 6 or more, more preferably 7 or more, even more preferably 8 or more, still more preferably 9 or more, and even more preferably 10 or more, and preferably 18 or less, more preferably 16 or less, even more preferably 14 or less, still more preferably 13 or less, and even more preferably 12 or less.

[0024] It goes without saying that the polyamide resin (A) does not completely exclude monomer units other than diamine units and dicarboxylic acid units as the main components, and may contain lactam units such as ε-caprolactam and laurolactam, and aliphatic aminocarboxylic acid units such as aminocaproic acid and aminoundecanoic acid. In particular, the polyamide resin (A) used in the present embodiment preferably contains aminocarboxylic acid units. In this embodiment, among the monomer units constituting the polyamide resin (A), the total number of diamine units, dicarboxylic acid units, and aminocarboxylic acid units, which are included as necessary, accounts for preferably 90 mass% or more of all monomer units, more preferably 95 mass% or more, even more preferably 97 mass% or more, and even more preferably 99 mass% or more. In the polyamide resin (A), the molar ratio of diamine units to dicarboxylic acid units is preferably from 40:60 to 60:40, and more preferably from 45:55 to 55:45. In addition, in this embodiment, the proportion of aminocarboxylic acid units among all monomer units constituting the polyamide resin (A) is preferably 1 mol % or more, more preferably 5 mol % or more, and is preferably 50 mol % or less, more preferably 40 mol % or less.

[0025] The polyamide resin (A) is preferably an amorphous resin. An amorphous resin is a resin that does not have a clear melting point, specifically, a crystalline melting enthalpy ΔHm of less than 5 J / g, preferably 3 J / g or less, more preferably 1 J / g or less. The crystalline melting enthalpy ΔHm is measured in the heating process according to JIS K7121 and K7122. Specifically, the polyamide resin is heated in a nitrogen gas flow from room temperature to 250° C. at a heating rate of 10° C. / min using a differential scanning calorimeter (DSC), immediately cooled to below room temperature, and then heated again from room temperature to 250° C. at a heating rate of 10° C. / min. The value is the value measured.

[0026] It is also preferable to use polyamide resin (A) manufactured using biomass raw materials (biomass polyamide resin). By using biomass polyamide resin, it is possible to reduce the environmental impact. For polyamide resin (A), mass balance certified (ISCC PLUS) monomer raw materials can also be used. Mass balance certification means that the amount of renewable raw materials and bio raw materials used in each factory or production facility and the amount of products produced or shipped are quantified and guaranteed together with the quality. In addition, the polyamide resin (A) may be a recycled product (including recovered products, material recycled products, chemical recycled products, etc.), a rejected product, or scraps generated during molding of the polyamide resin (A) or the resin composition of the present embodiment.

[0027] The content of the polyamide resin (A) in the resin composition of this embodiment is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 97% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more, based on 100% by mass of the resin composition. By making it equal to or more than the lower limit, the glass transition temperature tends to be higher. In addition, the content of the polyamide resin (A) in the resin composition of this embodiment is preferably 99.999% by mass or less, based on 100% by mass of the resin composition. By making it equal to or less than the upper limit, the transparency of the obtained film tends to be further improved. In addition, the resin composition of this embodiment may be composed of all components other than the release agent (B) as polyamide resin (A). The resin composition of the present embodiment may contain only one type of polyamide resin (A), or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0028] The resin composition of the present embodiment may or may not contain a polyamide resin other than the polyamide resin (A). Examples of polyamide resins other than the polyamide resin (A) include aliphatic polyamide resins and aromatic polyamide resins other than the polyamide resin (A). Examples of aliphatic polyamide resins include polyamide 4, polyamide 46, polyamide 6, polyamide 66, polyamide 666, polyamide 610, polyamide 11, polyamide 116, polyamide 12, polyamide 612, and the like. Examples of aromatic polyamide resins include polyhexamethylene terephthalamide (polyamide 6T), polyhexamethylene isophthalamide (polyamide 6I), polyamide 66 / 6T, polyamide 9T, polyamide 9MT, polyamide 10T, polyamide 6I / 6T, xylylenediamine-based polyamide resins (such as MXD6), and the like.

[0029] As the aliphatic polyamide resins and aromatic polyamide resins other than the polyamide resin (A), it is also preferable to use recycled resins or polyamide resins produced using biomass raw materials (biomass thermoplastic resins). In addition, the resin composition of the present embodiment preferably does not substantially contain any polyamide resin other than the polyamide resin (A). Specifically, the content of polyamide resins other than the polyamide resin (A) contained in the resin composition of the present embodiment is preferably less than 10 mass%, more preferably less than 5 mass%, even more preferably less than 3 mass%, even more preferably less than 1 mass%, and even more preferably less than 0.1 mass%, based on 100 mass% of the resin composition.

[0030] <Release agent> The resin composition of the present embodiment contains a release agent (hereinafter sometimes referred to as "release agent (B)") that contains a fatty acid ester and / or a fatty acid amide, and the fatty acid constituting the fatty acid ester and / or the fatty acid amide is a fatty acid having 7 to 30 carbon atoms. By using such a release agent in combination with the polyamide resin (A), a resin composition that can provide a film that is excellent in transparency and can effectively suppress roll contamination during film production can be obtained.

[0031] Fatty acid esters are usually composed of fatty acids and alcohols, while fatty acid amides are, for example, composed of fatty acids and ammonia and / or amines, or are obtained by ammonolysis of fatty acid esters. It goes without saying that the fatty acid esters and / or fatty acid amides used in this embodiment are not limited to these.

[0032] In this embodiment, the carbon number of the fatty acid constituting these fatty acid esters or fatty acid amides is 7 or more, preferably 8 or more, more preferably 9 or more, even more preferably 10 or more, even more preferably 11 or more, and 30 or less, preferably 28 or less, more preferably 26 or less, even more preferably 24 or less, even more preferably 22 or less, and even more preferably 20 or less. By making it equal to or more than the lower limit, the release agent tends to bleed out easily onto the resin surface during molding, and the effect of suppressing roll contamination tends to be improved. In addition, by making it equal to or less than the upper limit, the compatibility with the resin tends to be improved, and the release agent itself tends to be effectively suppressed from becoming roll contamination. The fatty acid may be a straight-chain fatty acid, a branched fatty acid, or a fatty acid having an alicyclic structure, but is preferably a straight-chain fatty acid and / or a branched fatty acid. The fatty acid may be a saturated fatty acid or an unsaturated fatty acid. The fatty acid may be a hydroxycarboxylic acid. The number of carboxy groups (-COOH) contained in one fatty acid molecule is preferably 1-10, and more preferably 1-4.

[0033] Here, the fatty acid ester will be described in detail. The number of ester bonds (-C(=O)O-) in one molecule of the fatty acid ester is preferably 1 to 10, and more preferably 1 to 4. The fatty acid ester used in this embodiment is preferably a full ester (a fatty acid ester that does not contain unesterified COOH). The alcohol constituting the fatty acid ester is preferably an aliphatic alcohol. The aliphatic alcohol may be a straight-chain aliphatic alcohol, a branched aliphatic alcohol, or an aliphatic alcohol having an alicyclic structure, but is preferably a straight-chain aliphatic alcohol and / or a branched aliphatic alcohol. The aliphatic alcohol may be a saturated aliphatic alcohol or an unsaturated aliphatic alcohol, but is preferably a saturated aliphatic alcohol. The aliphatic alcohol is preferably a monohydric to decahydric alcohol, and more preferably a monohydric to tetrahydric alcohol. The number of carbon atoms in the aliphatic alcohol is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more, and is preferably 30 or less, more preferably 25 or less, even more preferably 20 or less, even more preferably 15 or less, and even more preferably 10 or less.

[0034] In the present embodiment, the aliphatic ester is preferably at least one of monoesters, diesters, triesters, and tetraesters composed of a fatty acid having 7 to 30 carbon atoms and a monohydric to tetrahydric alcohol. The fatty acid ester is preferably a full ester. The molecular weight of the fatty acid ester is preferably 100 or more and 2,000 or less.

[0035] Specific examples of fatty acid esters used in the present embodiment include those exemplified in the Examples described later, as well as methyl laurate, methyl stearate, methyl oleate, butyl stearate, isopropyl myristate, isopropyl palmitate, 2-ethylhexyl palmitate, 2-ethylhexyl stearate, 2-ethylhexyl oleate, cetyl myristate, myristyl myristate, stearyl stearate, behenyl behenate, and montanic acid wax.

[0036] Next, the fatty acid amide will be described in detail. The number of amide bonds (-C(=O)NH-) in one molecule of the fatty acid amide is preferably 1-10, and more preferably 1-4. The fatty acid amide is preferably composed of a fatty acid and an amine. The amine constituting the fatty acid amide is preferably an aliphatic amine. The aliphatic amine may be a linear aliphatic amine, a branched aliphatic amine, or an aliphatic amine having an alicyclic structure, but is preferably a linear aliphatic amine and / or a branched aliphatic amine. The aliphatic amine may be a saturated aliphatic amine or an unsaturated aliphatic amine, but is preferably a saturated aliphatic amine. Moreover, the aliphatic amine preferably has 1 to 10 amino groups, and more preferably has 1 to 4 amino groups, in one molecule.

[0037] In the present embodiment, the aliphatic amide is preferably at least one of monoamides, diamides, triamides, and tetraamides, each of which is composed of a fatty acid having 7 to 30 carbon atoms and an amine having 1 to 4 amino groups in one molecule. 2 ) is preferably a fatty acid amide that does not have The molecular weight of the fatty acid amide is preferably 100 or more and 1,000 or less.

[0038] Specific examples of the fatty acid amide used in the present embodiment include those exemplified in the examples described later, as well as stearic acid amide, oleic acid amide, erucic acid amide, behenic acid amide, palmitic acid amide, ethylene bisoleic acid amide, and ethylene biserucic acid amide.

[0039] When the resin composition of the present embodiment contains a release agent (B), the content is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, even more preferably 0.01% by mass or more, even more preferably 0.1% by mass or more, even more preferably 0.3% by mass or more, and preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 3% by mass or less, even more preferably 2% by mass or less, and even more preferably 1% by mass or less, based on 100% by mass of the resin composition. By making the content equal to or more than the lower limit, roll contamination during molding tends to be effectively suppressed. Also, by making the content equal to or less than the upper limit, the decrease in glass transition temperature and toughness tends to be more effectively suppressed. In the resin composition of the present embodiment, the total amount of the polyamide resin (A) and the release agent (B) does not exceed 100% by mass. The resin composition of the present embodiment may contain only one type of release agent (B), or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range. In addition, the resin composition of the present embodiment preferably does not substantially contain a release agent other than the release agent (B). Specifically, the content of the release agent other than the release agent (B) contained in the resin composition of the present embodiment is preferably less than 10 parts by mass, more preferably less than 5 parts by mass, even more preferably less than 3 parts by mass, even more preferably less than 1 part by mass, and even more preferably less than 0.1 parts by mass, relative to 100 parts by mass of the release agent (B).

[0040] <Other ingredients> The resin composition of the present embodiment may or may not contain components other than the polyamide resin (A) and the release agent (B). Examples of other components include ultraviolet absorbers, antioxidants, heat stabilizers, flame retardants, flame retardant assistants, colorants, 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 resin composition of this embodiment may contain additives described in paragraphs 0047 to 0103 of International Publication No. 2021 / 241471 and additives described in paragraphs 0041 to 0056 of JP-A-2023-61203, within the scope of the spirit of the present invention, and the contents of these are incorporated herein by reference.

[0041] When other components are contained, the total content thereof is preferably 0.001 to 3 mass% of the resin composition, more preferably less than 2 mass%, even more preferably less than 1 mass%, even more preferably less than 0.5 mass%, even more preferably less than 0.1 mass%, and may be less than 0.01 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.

[0042] <Physical properties of resin composition> The resin composition of the present embodiment preferably has excellent transparency. Specifically, the resin composition of the present embodiment has a total light transmittance of preferably 80% or more, more preferably 85% or more, and even more preferably 90% or more when molded to a thickness of 300 μm. The upper limit of the total light transmittance is preferably 100%, but the required performance is satisfied even if it is 99% or less. Furthermore, the resin composition of this embodiment has a haze of preferably 3.0% or less, more preferably 2.0% or less, even more preferably 1.5% or less, even more preferably 1.0% or less, even more preferably 0.7% or less, even more preferably 0.5% or less, and even more preferably less than 0.3%, 0.28% or less, or 0.25% or less when molded to a thickness of 300 μm. The lower limit of the haze is preferably 0%, but the required performance is satisfied even if it is 0.001% or more. The total light transmittance and haze are measured according to the description in the Examples section below.

[0043] <Method of producing resin composition> As a method for producing the resin composition of the present embodiment, any method may be adopted. For example, it can be obtained by adding polyamide resin (A) and release agent (B) and melt-kneading them. More specifically, the polyamide resin (A), release agent (B), and other components added as necessary are mixed using a mixing means such as a V-type blender to prepare a lump-sum blend, which is then melt-kneaded in a vented extruder and pelletized.

[0044] <Film> The film of this embodiment is formed from the film of this embodiment. The thickness of the film in this embodiment is preferably 10 μm or more, more preferably 50 μm or more, and even more preferably 100 μm or more, and is preferably 1000 μm or less, more preferably 800 μm or less, even more preferably 700 μm or less, even more preferably 600 μm or less, and even more preferably 500 μm or less.

[0045] The film of the present embodiment preferably has excellent transparency. Specifically, the film of the present embodiment has a total light transmittance of preferably 80% or more, more preferably 85% or more, and even more preferably 90% or more. The upper limit of the total light transmittance of the film is preferably 100%, but the required performance is satisfied even if it is 99% or less. The haze of the film of the present embodiment is preferably 3.0% or less, more preferably 2.5% or less, even more preferably less than 2.0%, even more preferably 1.8% or less, even more preferably 1.7% or less, and even more preferably 1.5% or less. The lower limit of the haze of the film is preferably 0%, but the required performance is satisfied even if it is 0.001% or more. The total light transmittance and haze are measured according to the description in the Examples section below.

[0046] <Wound body> The film of the present embodiment can be wound around a core material to form a roll.

[0047] <Polarizing sheet> A film formed from the resin composition of the present embodiment or the film of the present embodiment is preferably used as a protective film for a polarizing sheet (a film that protects a polarizing film). In this embodiment, the polarizing sheet preferably includes the film of this embodiment and a polarizing film, and is a sheet laminated in this order of the polarizing film and the protective film. That is, the film of this embodiment is preferably used as at least one of the protective films of the polarizing sheet. The protective film is usually attached to the polarizing film via an adhesive. In this embodiment, one of the protective films of the polarizing sheet may be the film of this embodiment, or may be another protective film. The other protective film of the polarizing sheet may be a known protective film of a polarizing sheet, and may be the same as the film of this embodiment. The polarizing film may be a known one, and an example thereof is a polyvinyl alcohol (PVA) film in which iodine or a dichroic organic dye is adsorbed or impregnated. The adhesive for bonding the film / protective film and the polarizing film of the present embodiment can be a known adhesive, and examples of such adhesives 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. In addition, the polarizing sheet of the present embodiment may further include a masking film or the like provided on the outer side of the protective film.

[0048] In this embodiment, the polarizing sheet of this embodiment is preferably used for a heat-bent product that has been subjected to heat bending processing. When the film of the present embodiment is used in a polarizing sheet, it may be provided on either side of a polarizing film, or on both sides. The first mode is that the film of this embodiment is disposed so as to be located on the convex side of the polarizing film after heat bending processing, for example, on the side of protective film 4 in FIG. In the second embodiment, the film of this embodiment is disposed so as to be located on the concave side of the polarizing film after heat bending processing, for example, on the side of protective film 3 in FIG. In the third embodiment, the film of this embodiment is positioned on both sides of a polarizing film, for example, both of protective films 3 and 4 in FIG. 1 are the film of this embodiment. In FIG. 1, the lens 1, the polarizing film 2, and the protective films 3 and 4 are bent, but it goes without saying that this embodiment also includes polarizing sheets that are not bent. The protective film used in the polarizing sheet of the present embodiment may be stretched or may not be stretched. In the first embodiment, it is preferably stretched. In the second embodiment, it is preferably not stretched.

[0049] In this embodiment, the polarizing sheet is preferably used as a polarizing sheet for use in liquid crystal display devices, polarizing lenses (sunglasses, ski goggles, prescription eyeglass lenses, camera viewfinder lenses), covers for various instruments, glass for automobiles, glass for trains, polarizing sheets for in-vehicle display panels and electronic device housings, etc., in-vehicle inner mirrors, silver mirrors for helmets, etc., and is particularly preferably used as sunglasses. EXAMPLES

[0050] The present invention will be described in more detail below with reference to examples. The materials, amounts, ratios, processing contents, 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.

[0051] 1.Raw materials A1: G850, manufactured by Arkema, a polyamide resin synthesized from bis(4-amino-3-methylcyclohexyl)methane, sebacic acid, and aminoundecanoic acid (the ratio of aminoundecanoic acid is 17 mol% relative to 100 mol% of the raw material monomer), amorphous polyamide resin A2: XE4205, manufactured by EMS, a polyamide resin synthesized from bis(4-amino-3-methylcyclohexyl)methane and sebacic acid, amorphous polyamide resin

[0052] B1: S-100A, Riken Vitamin Co., Ltd., fatty acid ester [ka] B2: EB-P, Kao Corporation, fatty acid amide [ka] B3: OHG, manufactured by Dainichi Chemical Industry Co., Ltd., a mixture mainly composed of fatty acid esters composed of castor hardened oil, ricinoleic acid and glycerin B4:H-476, manufactured by NOF Corporation, fatty acid ester [ka] B5: Tokyo Chemical Industry Co., Ltd., butyl laurate [ka] B6: OHC, Dainichi Chemical Industry Co., Ltd., fatty acid metal salt, calcium 12-hydroxystearate B7: Ethyl hexanoate, manufactured by Tokyo Chemical Industry Co., Ltd. B8: Tokyo Chemical Industry Co., Ltd., 12-hydroxystearic acid B9: JP-518-O, manufactured by Johoku Chemical Co., Ltd., phosphoric acid ester, oleyl acid phosphate

[0053] 2. Examples 1 to 10 and Comparative Examples 1 to 6 <Production of resin pellets> The components were blended in a tumbler to obtain the compositions shown in Tables 1 to 3 below (contents are shown in parts by mass in Tables 1 to 3), and the blend was fed into the base of a twin-screw extruder (TEX30α, manufactured by Japan Steel Works, Ltd.) and melt-kneaded at a cylinder temperature of 280°C to produce pellets for the examples and comparative examples.

[0054] <Film manufacturing> The pellets obtained above were extruded in a molten state using a T-die melt extruder consisting of a vented twin-screw extruder (manufactured by Shibaura Machine Co., Ltd., "TEM-26DS") with a screw nominal diameter of 28 mm and a screw L / D=40 at a discharge rate of 15 kg / h and a screw rotation speed of 250 rpm, and the extrusion was pressed with a first roll and a second roll, and then cooled and solidified to produce a film. The cylinder temperature and die temperature were 280°C, and the first roll and second roll temperatures were 120°C. A film with a thickness of 300 μm was obtained. Details of the first roll and second roll used are as follows. First roll: Shibaura Machine Co., Ltd., UM roll Dimensions: Outer diameter 180mm x roll width 400mm Second roll: Shibaura Machine Co., Ltd., rigid metal roll (surface: chrome-treated) Dimensions: Outer diameter 180mm x roll width 400mm

[0055] <Roll stains> The second roll after consuming 30 kg of raw material in the case of evaluation of Polyamide A1 and 90 kg of raw material in the case of using Polyamide A2 to produce a film was visually evaluated as follows: The evaluation was carried out by five experts and judged by majority vote. A: No roll staining was observed, or some roll staining was observed but at a level that was acceptable for practical use. B: Roll contamination occurred, beyond the practical level.

[0056] <Haze and total light transmittance measurements> The haze (%) and total light transmittance (%) of the 300 μm thick film obtained above were measured using a haze meter under conditions of a D65 light source and a 10° visual field. The haze meter used was "HM-150" manufactured by Murakami Color Research Laboratory.

[0057] [Table 1]

[0058] [Table 2]

[0059] [Table 3]

[0060] As is clear from the results in Tables 1 to 3, in the present invention, roll contamination was effectively suppressed and a film with excellent transparency was obtained. In contrast, when no release agent was included (Comparative Examples 1 and 2), or when a release agent was included but was other than the release agent specified in the present invention (Comparative Examples 3 to 6), roll contamination occurred. [Explanation of symbols]

[0061] 1 Lens 2. Polarizing film 3 Protective film 4 Protective film

Claims

1. The present invention includes a polyamide resin including an alicyclic diamine unit and an aliphatic dicarboxylic acid unit having 7 to 20 carbon atoms, and a release agent, the release agent comprises a fatty acid ester and / or a fatty acid amide; The resin composition, wherein the fatty acid constituting the fatty acid ester and / or fatty acid amide is a fatty acid having 7 to 30 carbon atoms.

2. The resin composition according to claim 1, wherein the aliphatic dicarboxylic acid unit having 7 to 20 carbon atoms includes a sebacic acid unit and / or a dodecanedioic acid unit.

3. The resin composition according to claim 1 or 2, wherein an alicyclic diamine constituting the alicyclic diamine unit contains two substituted or unsubstituted cyclohexane rings.

4. The resin composition according to claim 1 or 2, wherein the alicyclic diamine unit includes a unit represented by formula (PA-1). 【Chemistry 1】 (In formula (PA-1), R １ are each independently an alkyl group having 1 to 5 carbon atoms, and each n1 is independently an integer of 0 to 3. * is a bonding site with another unit or a terminal group.

5. The resin composition according to any one of claims 1 to 4, wherein the content of the release agent contained in the resin composition is 0.001 to 10 mass%.

6. The aliphatic dicarboxylic acid unit having 7 to 20 carbon atoms includes a sebacic acid unit and / or a dodecanedioic acid unit, The alicyclic diamine unit includes a unit represented by formula (PA-1), The resin composition according to any one of claims 1 to 5, wherein the content of the release agent contained in the resin composition is 0.001 to 10 mass%. 【Chemistry 2】 (In formula (PA-1), R １ are each independently an alkyl group having 1 to 5 carbon atoms, and each n1 is independently an integer of 0 to 3. * is a bonding site with another unit or a terminal group.

7. The resin composition according to any one of claims 1 to 6, wherein the polyamide resin is an amorphous resin.

8. The resin composition according to any one of claims 1 to 7, wherein the haze of the resin composition when molded into a film having a thickness of 300 µm is 3.0% or less.

9. The resin composition according to any one of claims 1 to 8, wherein the resin composition has a total light transmittance of 80% or more when molded into a film having a thickness of 300 µm.

10. The resin composition according to any one of claims 1 to 9, which is for use as a protective film for a polarizing sheet.

11. A film formed from the resin composition according to any one of claims 1 to 10.

12. A polarizing sheet comprising the film according to claim 11 and a polarizing film.

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

Images