Modified product of hydrogenated block copolymer, resin composition, and molded body

Abstract

A modified product (A) of a hydrogenated block copolymer (X), wherein: a modifier of the modified product (A) is an unsaturated carboxylic acid or a derivative thereof; the hydrogenated block copolymer (X) is a hydrogenated product of a block copolymer (x) that comprises a block (x1) which contains more than 30 mass% of a unit derived from a conjugated diene compound and a block (x2) which contains more than 70 mass% of a unit derived from a vinyl aromatic compound; and the content of the unit derived from a vinyl aromatic compound with respect to the total mass of the modified product (A) is 52.0-64.5 mass%.

Description

Modified hydrogenated block copolymers, resin compositions, and molded articles

[0001] The present invention relates to modified hydrogenated block copolymers, resin compositions, and molded articles.

[0002] Hydrogenated block copolymers are materials that possess rubber elasticity at room temperature and can be easily molded and processed by heating, as they plasticize and melt. Furthermore, due to their excellent balance of flexibility and mechanical properties, they are used in a wide range of fields, including automotive parts, home appliances, wire insulation, medical components, general merchandise, and footwear. In recent years, they have also attracted attention as an alternative material to polyvinyl chloride resin in response to environmental concerns.

[0003] In applications where it is necessary to improve the compatibility between hydrogenated block copolymers and polar resins, etc., it is common practice to use modified hydrogenated block copolymers that have been modified with unsaturated carboxylic acids, etc.

[0004] Furthermore, there is a known technique for improving the mechanical strength of a resin by adding a modifier, such as a modified hydrogenated block copolymer, to the resin. In these techniques, bringing the refractive index of the modifier and the resin closer together is important from the viewpoint of improving the physical properties of the resin, such as transparency.

[0005] For example, Patent Document 1 describes a technique for obtaining a resin composition in which mechanical properties are improved without impairing the transparency of the transparent polyamide by adding a modified styrene-based thermoplastic elastomer to the transparent polyamide.

[0006] Japanese Patent Publication No. 2018-119100

[0007] The technology described in Patent Document 1 shows room for further improvement in terms of improving the refractive index of the modified styrene-based thermoplastic elastomer and mechanical properties such as tensile elongation at fracture.

[0008] The present invention aims to provide a modified hydrogenated block copolymer having a high refractive index and an excellent balance between elongation and stress (tensile fracture elongation and tensile fracture stress), a resin composition containing the modified copolymer, and a molded article containing the composition.

[0009] In other words, the present invention and means for solving the above problems relate, for example, to the following matters [1] to

[22] . [1] A modified product (A) of a hydrogenated block copolymer (X), wherein the modifier of the modified product (A) is an unsaturated carboxylic acid or a derivative thereof, the hydrogenated block copolymer (X) is a hydrogenated product of a block copolymer (x) comprising a block (x1) containing more than 30% by mass of units derived from a conjugated diene compound and a block (x2) containing more than 70% by mass of units derived from a vinyl aromatic compound, and the content of units derived from the vinyl aromatic compound relative to the total mass of the modified product (A) is 52.0 to 64.5% by mass, the modified product (A) of a hydrogenated block copolymer (X).

[0010] [2] The modified product (A) according to [1], wherein the block (x1) is a copolymer block (x1-a) further containing units derived from a vinyl aromatic compound.

[0011] [3] The modified product (A) according to [2], wherein the hydrogenated block copolymer (X) is a triblock copolymer consisting of a styrene polymer block, a hydrogenated styrene-butadiene random copolymer block, and a styrene polymer block.

[0012] [4] A modified product (A) according to any one of [1] to [3], wherein the hydrogenated block copolymer (X) is a mixture containing 40 to 95% by mass of a hydrogenated block copolymer (X-1) that satisfies the following requirement (1), and 60 to 5% by mass of a hydrogenated block copolymer (X-2) that satisfies the following requirement (2) (provided that the total amount of the block copolymers (X-1) and (X-2) is 100% by mass). Requirement (1): The content of units derived from the vinyl aromatic compound relative to the total mass of the block copolymer (X-1) is greater than 59% by mass and 75% by mass or less. Requirement (2): The content of units derived from the vinyl aromatic compound relative to the total mass of the block copolymer (X-2) is 43 to 59% by mass.

[0013] [5] The modified product (A) according to any one of [1] to [4], wherein the content of the unit derived from the vinyl aromatic compound with respect to the total mass of the modified product (A) is 54.0% by mass or more and less than 62.0% by mass.

[0014] [6] The modified product (A) according to any one of [1] to [5], wherein the content of the unit derived from the vinyl aromatic compound with respect to the total mass of the modified product (A) is 56.0 to 64.5% by mass.

[0015] [7] The modified product (A) according to any one of [1] to [6], wherein the content of the unit derived from the vinyl aromatic compound with respect to the total mass of the modified product (A) is 56.0% by mass or more and less than 62.0% by mass.

[0016] [8] The modified product (A) according to any one of [1] to [7], wherein the content of the unit derived from the vinyl aromatic compound with respect to the total mass of the modified product (A) is 56.0 to 64.5% by mass, and the hydrogenated block copolymer (X) is a triblock copolymer composed of a styrene polymer block - a hydrogenated styrene / butadiene random copolymer block - a styrene polymer block.

[0017] [9] The modified product (A) according to any one of [1] to [8], wherein the MFR (230 °C, 2.16 kg load) of the modified product (A) is 35 g / 10 min or less.

[0018]

[10] The modified product (A) according to any one of [1] to [9], wherein the content of the unit derived from an unsaturated carboxylic acid or its derivative with respect to the total mass of the modified product (A) is 0.05 to 10.0% by mass.

[0019]

[11] The modified product (A) according to any one of [1] to

[10] , wherein the content of the unit derived from an unsaturated carboxylic acid or its derivative with respect to the total mass of the modified product (A) is 0.05 to 1.0% by mass.

[0020]

[12] The modified product (A) according to any one of [1] to

[11] , wherein the content of units derived from an unsaturated carboxylic acid or its derivative, relative to the total mass of the modified product (A), is 0.05 to 1.0% by mass, and the content of units derived from the vinyl aromatic compound, relative to the total mass of the modified product (A), is 56.0 to 64.5% by mass.

[0021]

[13] The modified product (A) according to any one of [1] to

[12] , wherein the content of units derived from an unsaturated carboxylic acid or its derivative with respect to the total mass of the modified product (A) is 0.05 to 1.0% by mass, and the hydrogenated block copolymer (X) is a triblock copolymer consisting of a styrene polymer block, a hydrogenated styrene-butadiene random copolymer block, and a styrene polymer block.

[0022]

[14] The modified product (A) according to any one of [1] to

[13] , wherein the refractive index of the modified product (A) is 1.549 or greater.

[0023]

[15] The modified material (A) has a refractive index of 1.549 or more, and when the balance between the tensile fracture stress and the tensile fracture elongation of the modified material (A) is expressed as a first balance index shown in the following formula (1), the first balance index is 90 or more, as described in any of [1] to

[14] . First balance index = (Tensile fracture stress (MPa) × Tensile fracture elongation (%)) / 100 ... Formula (1)

[0024]

[16] A modified product (A) according to any one of [1] to

[15] , for modifying polyamide resins having a refractive index of 1.543 or higher.

[0025]

[17] A resin composition comprising a modified product (A) of a hydrogenated block copolymer (X) described in any of [1] to

[16] and a polyamide resin (B).

[0026]

[18] The resin composition according to

[17] , wherein the hydrogenated block copolymer (X) is a triblock copolymer consisting of a styrene polymer block, a hydrogenated styrene-butadiene random copolymer block, and a styrene polymer block.

[0027]

[19] The resin composition according to

[17] or

[18] , wherein the refractive index of the resin composition is 1.550 or more.

[0028]

[20] A resin composition according to any one of

[17] to

[19] , comprising the modified product (A) in an amount of 2 to 40% by mass and the polyamide resin (B) in an amount of 98 to 60% by mass (provided that the total amount of the modified product (A) and the polyamide resin (B) is 100% by mass).

[0029]

[21] The resin composition according to any one of

[17] to

[20] , wherein the content of units derived from an unsaturated carboxylic acid or its derivative with respect to the total mass of the modified product (A) is 0.05 to 10.0% by mass.

[0030]

[22] A molded article comprising the resin composition described in any of

[17] to

[21] .

[0031] According to the present invention, it is possible to provide a modified hydrogenated block copolymer having a high refractive index and an excellent balance between elongation and stress (tensile fracture elongation and tensile fracture stress), a resin composition containing the modified copolymer, and a molded article containing the composition.

[0032] The present invention will now be described in detail, specifically an example of a preferred embodiment. These descriptions and examples are illustrative of embodiments and do not limit the scope of embodiments. In this specification, a combination of two or more preferred embodiments is a more preferred embodiment. In this specification, a numerical range expressed using "~" means a range that includes the numbers before and after "~" as the lower and upper limits. In numerical ranges described stepwise in this specification, the upper or lower limit stated in one numerical range may be replaced with the upper or lower limit of another numerical range described stepwise. Also, in numerical ranges described in this specification, the upper or lower limit stated in one numerical range may be replaced with the value shown in the example. In this specification, the amount of each component in a composition means the total amount of multiple substances present in the composition if there are multiple substances corresponding to each component in the composition, unless otherwise specified. In this specification, "%" indicating the amount of contained components is on a mass basis unless otherwise specified.

[0033] [Modified product (A) of hydrogenated block copolymer (X)] The modified product (A) of hydrogenated block copolymer (X) of the present invention (hereinafter also referred to as "modified product (A)") is characterized in that the modifying agent of the modified product (A) is an unsaturated carboxylic acid or a derivative thereof, and the hydrogenated block copolymer (X) is a hydrogenated product of a block copolymer (x) comprising a block (x1) containing more than 30% by mass of units derived from a conjugated diene compound and a block (x2) containing more than 70% by mass of units derived from a vinyl aromatic compound, and the content of units derived from the vinyl aromatic compound relative to the total mass of the modified product (A) is 52.0 to 64.5% by mass.

[0034] <Hydrogenated Block Copolymer (X)> Hydrogenated block copolymer (X) (hereinafter also referred to as "copolymer (X)") is a hydrogenated product of block copolymer (x) containing a block (x1) containing more than 30% by mass of units derived from a conjugated diene compound and a block (x2) containing more than 70% by mass of units derived from a vinyl aromatic compound. One type of copolymer (X) may be used, or two or more types may be used.

[0035] Block (x1) Block (x1) contains more than 30% by mass, preferably 40% by mass or more, and more preferably 45% by mass or more, units derived from the conjugated diene compound.

[0036] Examples of conjugated diene compounds that serve as units derived from conjugated diene compounds include 1,3-butadiene, isoprene (2-methyl-1,3-butadiene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, and 1,3-hexadiene. Among these conjugated dienes, 1,3-butadiene and isoprene are preferred, with 1,3-butadiene being more preferred because it allows for easy acquisition of a modified product (A) with a high refractive index and an excellent balance between elongation and stress. One or more of these conjugated dienes may be used.

[0037] The above block (x1) may contain units derived from monomers other than those derived from the conjugated diene compound. Examples of other monomers include vinyl aromatic compounds and C4-C10 alkenes such as isobutylene. Examples of vinyl aromatic compounds include vinyl aromatic compounds similar to those that form the units of block (x2) described later, but styrene is preferred because it is easy to obtain a modified product (A) with a high refractive index and an excellent balance between elongation and stress.

[0038] The above block (x1) may contain only units derived from a conjugated diene compound, but a copolymer block (x1-a) containing units derived from both a conjugated diene compound and a vinyl aromatic compound is preferred, as it allows for easy acquisition of a modified product (A) with a high refractive index and excellent balance between elongation and stress, and a more preferred embodiment is that the copolymer block is a random copolymer. When the above block (x1) contains units derived from a vinyl aromatic compound, the content of units derived from the vinyl aromatic compound is usually less than 70% by mass, preferably 60% by mass or less, and more preferably 55% by mass or less.

[0039] The ratio of the total amount of 1,2-vinyl bonds and 3,4-vinyl bonds to the ethylenic double bonds in the units derived from the conjugated diene compound in block (x1) is preferably 5% or more and less than 60%, more preferably 25 to 55%, even more preferably 25 to 50%, and particularly preferably 35 to 48%, from the viewpoint of excellent rigidity, impact resistance, and chemical resistance. Here, the total amount of 1,2-vinyl bonds and 3,4-vinyl bonds (total vinyl bond amount) refers to the ratio of the sum of the amount of 1,2-vinyl bonds and 3,4-vinyl bonds in the units derived from the conjugated diene compound in block (x1) containing units derived from the conjugated diene compound before hydrogenation, to the sum of the amount of 1,2-vinyl bonds, 3,4-vinyl bonds, and 1,4-conjugated bonds. The total vinyl bond amount is measured using an infrared spectrophotometer, and Analytical Chemistry, Volume 21, No. 8. It can be calculated in accordance with the method described in August 1949.

[0040] The content of block (x1) in copolymer (X) is preferably 40 to 85% by mass, more preferably 45 to 85% by mass, and even more preferably 49 to 82% by mass. The content of block (x1) can be controlled by adjusting the amount of monomer feed.

[0041] If there are two or more blocks (x1) in the copolymer (X), each block (x1) may have the same structure or a different structure.

[0042] Block (x2) Each block (x2) contains more than 70% by mass, preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 100% by mass of units derived from a vinyl aromatic compound. Examples of block (x2) include a homopolymer block of a vinyl aromatic compound and a copolymer block of a vinyl aromatic compound and a conjugated diene compound.

[0043] Examples of vinyl aromatic compounds include styrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylethylene, N,N-dimethyl-p-aminoethylstyrene, and N,N-diethyl-p-aminoethylstyrene. Among these vinyl aromatic compounds, styrene is preferred because it has a high refractive index and allows for easy acquisition of a modified product (A) with an excellent balance of elongation and stress. One or more of these vinyl aromatic compounds may be used.

[0044] The content of blocks (x2) in the copolymer (X) is preferably 5 to 60% by mass, more preferably 6 to 55% by mass, and even more preferably 7 to 50% by mass, from the viewpoint of mechanical strength. The content of blocks (x2) can be controlled by adjusting the amount of monomer feed.

[0045] The content of block (x2) is defined by the following formula, using the mass of vinyl aromatic compound polymer blocks obtained by the method of oxidative decomposition of the copolymer before hydrogenation with tert-butyl hydroperoxide using osmium tetroxide as a catalyst (the method described in I.M. Kolthoff, et al., J. Polym. Sci. 1, 429 (1946), hereinafter also referred to as the "osmium tetroxide decomposition method") (where vinyl aromatic compound polymers with an average degree of polymerization of approximately 30 or less are excluded): Content of block (x2) (mass%) = (mass of vinyl aromatic compound polymer blocks in the copolymer before hydrogenation / mass of the copolymer before hydrogenation) × 100

[0046] If there are two or more blocks (x2) in the copolymer (X), each block (x2) may have the same structure or a different structure.

[0047] <Specific Examples of Hydrogenated Block Copolymers (X)> Specific examples of copolymers (X) include, for example, diblock copolymers (SEB) consisting of a styrene polymer block and a hydrogenated butadiene (ethylenebutylene) polymer block, triblock copolymers (SEBS) consisting of a styrene polymer block, a hydrogenated butadiene (ethylenebutylene) polymer block, and a styrene polymer block, and other block copolymers having a styrene polymer block and a hydrogenated butadiene (ethylenebutylene) polymer block; diblock copolymers (SEP) consisting of a styrene polymer block and a hydrogenated isoprene (ethylenepropylene) polymer block, triblock copolymers (SEPS) consisting of a styrene polymer block, a hydrogenated isoprene (ethylenepropylene) polymer block, and a styrene polymer block; Examples include block copolymers having styrene polymer blocks and hydrogenated butadiene / isoprene random copolymer blocks, such as diblock copolymers (SEEP) consisting of styrene polymer blocks and hydrogenated butadiene / isoprene random copolymer blocks, and triblock copolymers (SEEPS) consisting of styrene polymer blocks, hydrogenated butadiene / isoprene random copolymer blocks, and styrene polymer blocks; and block copolymers having styrene polymer blocks and hydrogenated styrene butadiene random copolymer blocks, such as diblock copolymers consisting of styrene polymer blocks and hydrogenated styrene / butadiene random copolymer blocks, and triblock copolymers consisting of styrene polymer blocks, hydrogenated styrene / butadiene random copolymer blocks, and styrene polymer blocks.

[0048] Among these hydrogenated block copolymers, block copolymers having a styrene polymer block and a hydrogenated butadiene polymer block, and block copolymers having a styrene polymer block and a hydrogenated styrene-butadiene random copolymer block are preferred because they allow for easier acquisition of a modified product (A) with a high refractive index and an excellent balance of elongation and stress. Triblock copolymers consisting of a styrene polymer block, a hydrogenated butadiene polymer block, and a styrene polymer block, and triblock copolymers consisting of a styrene polymer block, a hydrogenated styrene-butadiene random copolymer block, and a styrene polymer block are preferred, and triblock copolymers consisting of a styrene polymer block, a hydrogenated styrene-butadiene random copolymer block, and a styrene polymer block are even more preferred.

[0049] As the copolymer (X), a mixture containing two or more copolymers (X) can also be used.

[0050] A preferred embodiment of the above mixture is a mixture containing 40 to 95% by mass of a hydrogenated block copolymer (X-1) satisfying the following requirement (1), and 60 to 5% by mass of a hydrogenated block copolymer (X-2) satisfying the following requirement (2) (provided that the total amount of block copolymers (X-1) and (X-2) is 100% by mass). Requirement (1): The content of units derived from the vinyl aromatic compound relative to the total mass of the block copolymer (X-1) is greater than 59% by mass and less than or equal to 75% by mass. Requirement (2): The content of units derived from the vinyl aromatic compound relative to the total mass of the block copolymer (X-2) is 43 to 59% by mass. By using such a mixture as the copolymer (X), a modified product (A) with a high refractive index and an excellent balance of elongation and stress can be easily obtained. The content of units derived from the vinyl aromatic compound in requirements (1) and (2) can be measured by the method described in the examples below.

[0051] In the above mixture, when the total amount of block copolymer (X-1) and (X-2) is 100% by mass, the content of block copolymer (X-1) is preferably 45 to 90% by mass, more preferably 50 to 85% by mass, even more preferably 55 to 82% by mass, and particularly preferably 65 to 75% by mass, and the content of block copolymer (X-2) is preferably 55 to 10% by mass, more preferably 50 to 15% by mass, even more preferably 45 to 18% by mass, and particularly preferably 35 to 25% by mass. When the ratio of block copolymer (X-1) to (X-2) is within the above range, a modified product (A) with a high refractive index and an excellent balance of elongation and stress can be easily obtained.

[0052] In requirement (1), the content of units derived from vinyl aromatic compounds is preferably 61 to 73% by mass, more preferably 63 to 71% by mass, and even more preferably 65 to 69% by mass, in that it is possible to easily obtain a modified product (A) that has a high refractive index and an excellent balance between elongation and stress.

[0053] In requirement (2), the content of units derived from vinyl aromatic compounds is preferably 45 to 57% by mass, more preferably 47 to 55% by mass, and even more preferably 48 to 53% by mass, in that it is possible to easily obtain a modified product (A) that has a high refractive index and an excellent balance between elongation and stress.

[0054] Copolymer (X) may be a polymer using only biomass-derived raw materials, a polymer using only fossil fuel-derived raw materials, or a polymer using both biomass-derived and fossil fuel-derived raw materials. Fossil fuels include petroleum, coal, natural gas, shale gas, or fuels that combine these. Biomass includes all renewable natural raw materials and their residues, such as those of plant or animal origin, including fungi, yeasts, algae, and bacteria.

[0055] <Method for producing hydrogenated block copolymer (X)> The block copolymer (x) before hydrogenation can be produced by conventionally known methods depending on the units derived from the monomers contained in each block. For example, it can be produced by polymerizing the monomers constituting each polymer block by anionic polymerization, cationic polymerization, etc. The hydrogenated block copolymer (X) can be produced by hydrogenating the block copolymer (x). The hydrogenation reaction is usually carried out using a catalyst, but there are no particular restrictions on such a catalyst as long as it can hydrogenate units derived from conjugated diene compounds, and conventionally known catalysts can be used.

[0056] <Physical Properties of Hydrogenated Block Copolymer (X)> In copolymer (X), the hydrogenation rate to the unsaturated bonds contained in the units derived from the conjugated diene compound is preferably 75 mol% or more, more preferably 85 mol% or more, even more preferably 90 mol% or more, and particularly preferably 95 mol% or more. A hydrogenation rate within the above range is preferable because it improves the impact resistance of the modified product (A). The hydrogenation rate can be determined, for example, by quantifying the amount of remaining unsaturated bonds in the block (x1) by NMR measurement.

[0057] The content of units derived from the vinyl aromatic compound relative to the total mass of the copolymer (X) is preferably 53.5 to 66.5% by mass, more preferably 54.0 to 66.0% by mass, even more preferably 57.0 to 65.0% by mass, even more preferably 60.0 to 64.0% by mass, and particularly preferably 60.5 to 62.5% by mass, in that it is possible to easily obtain a modified product (A) with a high refractive index and an excellent balance of elongation and stress. The content of units derived from the vinyl aromatic compound can be measured by the method described in the examples below.

[0058] The density of the copolymer (X) is preferably 860 to 1,200 kg / m³. 3 More preferably 890 to 1,100 kg / m 3 More preferably 910 to 1,050 kg / m 3 Particularly preferred is 980 to 1,040 kg / m 3 That is the case.

[0059] The upper limit of the MFR (at 230°C and 2.16 kg load) of the copolymer (X), as measured in accordance with ASTM D1238, is preferably 100 g / 10 min or less, more preferably 50 g / 10 min or less, even more preferably 20 g / 10 min or less, and particularly preferably 10 g / 10 min or less. On the other hand, the lower limit of the MFR is not particularly limited, but may be, for example, 0.1 g / 10 min or more, or 0.2 g / 10 min or more. When the MFR is within the above range, the handling properties during the preparation of the resin composition are excellent.

[0060] The weight-average molecular weight of copolymer (X) (measured using gel permeation chromatography (GPC) in terms of polystyrene equivalent) is preferably 5,000 to 300,000, more preferably 8,000 to 250,000, and even more preferably 10,000 to 200,000, from the viewpoint of handling during the preparation of the resin composition.

[0061] <Modified product (A) of hydrogenated block copolymer (X)> The modified product (A) of the present invention is obtained by modifying the copolymer (X) using a modifying agent. Examples of the modifying agent include unsaturated carboxylic acids or their derivatives. One or more of these modifying agents may be used. Examples of unsaturated carboxylic acids include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, and isocrotonic acid; and unsaturated dicarboxylic acids such as maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, and nadic acid (registered trademark) (endosis-bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylic acid).

[0062] Examples of derivatives of unsaturated carboxylic acids include acid halide compounds, amide compounds, imide compounds, acid anhydrides, and ester compounds of the aforementioned unsaturated carboxylic acids. Specific examples of derivatives of unsaturated carboxylic acids include malenyl chloride, maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, and glycidyl maleate.

[0063] Among these unsaturated carboxylic acids or their derivatives, unsaturated dicarboxylic acids or their acid anhydrides are preferred, maleic acid, nadic acid (registered trademark), or their acid anhydrides are more preferred, and maleic acid or maleic anhydride is even more preferred.

[0064] The content of units derived from an unsaturated carboxylic acid or its derivative, relative to the total mass of the modified product (A), is preferably 0.05 to 10.0% by mass, more preferably 0.1 to 5.0% by mass, and even more preferably 0.2 to 3.0% by mass. In one embodiment, the content of units derived from the unsaturated carboxylic acid or its derivative may also be in the range of preferably 0.05 to 1.0% by mass. When the content of units derived from the unsaturated carboxylic acid or its derivative is within the above range, a modified product (A) with a high refractive index and an excellent balance between elongation and stress can be obtained. The content of units derived from the unsaturated carboxylic acid or its derivative can be measured by the method described in the examples below.

[0065] Methods for modifying the hydrogenated block copolymer (X) are not particularly limited, but examples include modification using esterification reactions and crosslinking reactions, as well as graft modification.

[0066] In one preferred embodiment, the modified product (A) of the present invention is a graft-modified product obtained by graft-modifying a hydrogenated block copolymer (X). Graft modification can be carried out by various conventionally known methods, for example, the following methods: (1) A method of graft modification (graft copolymerization) by melting the hydrogenated block copolymer (X) and adding an unsaturated carboxylic acid or the like. (2) A method of graft modification (graft copolymerization) by dissolving the hydrogenated block copolymer (X) in a solvent and adding an unsaturated carboxylic acid or the like.

[0067] In order to efficiently perform graft modification (graft copolymerization) of unsaturated carboxylic acids and the like, it is preferable to perform graft modification in the presence of a radical polymerization initiator. The radical polymerization initiator may be one type or two or more types.

[0068] Examples of the radical polymerization initiators include benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(peroxidebenzoate)-3-hexine, 1,4-bis(tert-butylperoxyisopropyl)benzene, lauroyl peroxide, tert-butyl peracetate, and 2,5-dimethyl-2,5-di-(tert-butylperoxide)-3-hexine. Examples of radical polymerization initiators include organic peroxides such as 2,5-dimethyl-2,5-di(tert-butylperoxide)hexane, tert-butylperbenzoate, tert-butylperphenylacetate, tert-butylperisobutyrate, tert-butylper-sec-octoate, tert-butylperpivalate, cumylperpivalate, and tert-butylperdiethylacetate; and azo compounds such as azobisisobutyronitrile and dimethylazoisobutyrate. Among these radical polymerization initiators, dialkyl peroxides such as dicumylperoxide, di-tert-butylperoxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)-3-hexine, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 1,4-bis(tert-butylperoxyisopropyl)benzene are preferred.

[0069] The radical polymerization initiator is typically used in an amount of 0.001 to 1 part by mass, preferably 0.005 to 0.5 parts by mass, and more preferably 0.01 to 0.3 parts by mass, per 100 parts by mass of the hydrogenated block copolymer (X).

[0070] The reaction temperature during graft modification is typically in the range of 60 to 350°C, preferably 150 to 300°C.

[0071] The content of units derived from the vinyl aromatic compound relative to the total mass of the modified product (A) is 52.0 to 64.5% by mass, preferably 53.0 to 64.3% by mass, more preferably 54.0 to 64.0% by mass, even more preferably 56.0 to 63.0% by mass, even more preferably 58.0 to 62.5% by mass, particularly preferably 59.0 to 62.0% by mass, and especially preferably 60.0 to 62.0% by mass. In one embodiment, the content of units derived from the vinyl aromatic compound may be preferably in the range of 54.0% by mass or more and less than 62.0% by mass, and even more preferably 56.0% by mass or more and less than 62.0% by mass. Furthermore, in one embodiment, the content of units derived from the vinyl aromatic compound may be preferably in the range of 56.0 to 64.5% by mass. When the content of units derived from the vinyl aromatic compound is within the above range, a modified product (A) with a high refractive index and an excellent balance between elongation and stress can be obtained. The content of units derived from the vinyl aromatic compound can be measured by the method described in the examples below. Furthermore, whether a single copolymer (X) is used as the raw material for the modified product (A), or a mixture containing two or more copolymers (X) is used, the content of units derived from vinyl aromatic compounds is measured according to the same method.

[0072] The upper limit of the MFR (at 230°C and 2.16 kg load) of the modified product (A), as measured in accordance with ASTM D1238, is preferably 100 g / 10 min or less, more preferably 75 g / 10 min or less, even more preferably 50 g / 10 min or less, and particularly preferably 35 g / 10 min or less. On the other hand, the lower limit of the MFR is not particularly limited, but may be, for example, 0.1 g / 10 min or more, or 0.3 g / 10 min or more. When the MFR is within the above range, the resin composition exhibits excellent dispersibility with respect to the polyamide resin.

[0073] The lower limit of the refractive index of the modified product (A) is preferably 1.543 or more, more preferably 1.546 or more, still more preferably 1.549 or more, even more preferably 1.552 or more, and particularly preferably 1.555 or more. On the other hand, the upper limit of the refractive index is not particularly limited, and for example, it may be 1.590 or less, or may be 1.580 or less. When the refractive index is within the above range, the difference from the refractive index of the polyamide resin in the resin composition can be reduced. The refractive index can be measured by the method described in the examples below.

[0074] The density of the modified product (A) is preferably 860 to 1,200 kg / m 3 , more preferably 890 to 1,100 kg / m 3 , still more preferably 910 to 1,050 kg / m 3 , particularly preferably 980 to 1,040 kg / m 3 . When the density is within the above range, the dispersibility in the polyamide resin in the resin composition is excellent.

[0075] The modified product (A) of the present invention is preferably for modifying a polyamide resin having a refractive index of 1.543 or more, more preferably for modifying a polyamide resin having a refractive index of 1.553 or more, still more preferably for modifying a polyamide resin having a refractive index of 1.563 or more, and particularly preferably for modifying a polyamide resin having a refractive index of 1.568 or more. Incidentally, "for modification" means that the refractive index in the resin composition described below is 1.550 or more, and the temperature balance of the Charpy impact strength ((T) × (U) × (V)) 1 / 3 is 6.0 or more.

[0076] The lower limit of the tensile breaking stress of the modified product (A) of the present invention is preferably 13 MPa or more, more preferably 14 MPa or more, still more preferably 15 MPa or more, even more preferably 16 MPa or more, and particularly preferably 17 MPa or more. On the other hand, the upper limit of the tensile breaking stress is not particularly limited, and for example, it may be 40 MPa or less, or may be 30 MPa or less. The tensile breaking stress can be measured by the method described in the examples below.

[0077] The lower limit of the tensile elongation at break of the modified product (A) of the present invention is preferably 400% or more, more preferably 430% or more, even more preferably 460% or more, even more preferably 490% or more, and particularly preferably 520% ​​or more. On the other hand, the upper limit of the tensile elongation at break is not particularly limited, but may be, for example, 1,000% or less, or 900% or less. The tensile elongation at break can be measured by the method described in the examples below.

[0078] The balance between tensile fracture stress and tensile fracture elongation is evaluated using the first balance index shown in the following formula (1): First balance index = (Tensile fracture stress (MPa) × Tensile fracture elongation (%)) / 100 ... Formula (1)

[0079] The lower limit of the first balance index is preferably 90 or higher, more preferably 90.5 or higher, even more preferably 91 or higher, even more preferably 92 or higher, and particularly preferably 95 or higher. On the other hand, the upper limit of the first balance index is not particularly limited, but may be, for example, 150 or lower, or 120 or lower. When the first balance index is within the above range, the balance between tensile fracture elongation and tensile fracture stress is excellent.

[0080] [Resin Composition] The resin composition according to the present invention comprises a modified product (A) of the hydrogenated block copolymer (X) and a polyamide resin (B).

[0081] <Polyamide Resin (B)> Polyamide resin (B) is typically a transparent polyamide resin, and as the transparent polyamide resin, at least one polyamide resin selected from the group consisting of amorphous polyamide resins and microcrystalline polyamide resins can be suitably used. Polyamide resin (B) may be one type or two or more types.

[0082] For example, monomers having an asymmetric chemical structure, raw material monomers having an aromatic ring structure, and raw material monomers having an alicyclic structure can be used as raw materials for the polyamide resin (B). One type of these raw material monomer may be used, or two or more types may be used.

[0083] By introducing an asymmetric chemical structure, transparent amorphous or microcrystalline polyamide resins can be obtained. The raw material monomers having an asymmetric chemical structure are not particularly limited, but examples include branched aliphatic diamines such as 2-methyl-1,5-pentanediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, and 1,2-propylenediamine.

[0084] Furthermore, transparent amorphous or microcrystalline polyamide resins can be obtained by introducing an aromatic ring structure into the polyamide resin. The raw material monomer having an aromatic ring structure is not particularly limited, but examples include aromatic dicarboxylic acids having 8 to 22 carbon atoms, such as 4,4'-diphenylmethanedicarboxylic acid, isophthalic acid, tributylisophthalic acid, terephthalic acid, 1,4-naphthalinedicarboxylic acid, 1,5-naphthalinedicarboxylic acid, 2,6-naphthalinedicarboxylic acid, 2,7-naphthalinedicarboxylic acid, diphenic acid, and diphenyl ether-4,4'-dicarboxylic acid.

[0085] Furthermore, transparent amorphous or microcrystalline polyamide resins can also be obtained by introducing an alicyclic structure into the polyamide resin. The raw material monomer having an alicyclic structure is not particularly limited, but examples include 1,4- or 1,3-bis(aminomethyl)cyclohexane, 4,4'-diaminodicyclohexylmethane, 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, 4,4'-diamino-3,3'-dimethyldicyclohexylpropane, and alicyclic diamines such as isophorone diamine.

[0086] Other raw material monomers, though not particularly limited, include, for example, aliphatic, alicyclic, or aromatic diamines, dicarboxylic acids, lactams, and / or aminocarboxylic acids having 6 to 36 carbon atoms.

[0087] Specific examples of polyamide resin (B) include polyamide PA12 / MACMI (PA12 / 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, isophthalic acid), PA12 / MACMT (PA12 / 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, terephthalic acid), PA MACM 12 (4,4'-diamino-3,3-dimethyldicyclohexylmethane, decanedicarboxylic acid or laurolactam), PA MC 12 (PA12, 1,3-bis(aminomethyl)cyclohexane), PA6I / 6T, PA6I / 6T / MACMI, PA MACM PACM 12 (4,4'-diamino-3,3'-dimethyldicyclohexylmethane, 4,4'-diaminodicyclohexylmethane, decanedicarboxylic acid or laurolactam). The notation for the polyamide resin follows JIS K6920-1.

[0088] The polyamide resin (B) may be a resin made using only biomass-derived raw materials, a resin made using only fossil fuel-derived raw materials, or a resin made using both biomass-derived and fossil fuel-derived raw materials.

[0089] As the polyamide resin (B), commercially available products can be used, for example, Tragamid® T5000 manufactured by Daicel Evonik.

[0090] The refractive index of the polyamide resin (B) is preferably 1.543 or higher, more preferably 1.553 or higher, even more preferably 1.563 or higher, and particularly preferably 1.568 or higher. When the refractive index is within the above range, the polyamide resin (B) tends to be transparent. The refractive index of the polyamide resin (B) can be adjusted to the above range, for example, by changing the raw material monomers that constitute the polyamide resin (B) (for example, monomers having an asymmetric chemical structure, raw material monomers having an aromatic ring structure, and raw material monomers having an alicyclic structure, etc.).

[0091] The density of the polyamide resin (B) is preferably 900 to 1,500 kg / m³. 3 More preferably 950 to 1,400 kg / m 3More preferably 1,000 to 1,300 kg / m 3 Therefore, when the density is within the aforementioned range, a modified material (A) with an excellent balance of elongation and stress can be easily obtained, and the resin composition exhibits excellent dispersibility with respect to the modified material (A).

[0092] The number-average molecular weight of the polyamide resin (B) may be, for example, 8,000 to 200,000, preferably 9,000 to 150,000, and more preferably 10,000 to 100,000. The number-average molecular weight can be measured using GPC or the like with polystyrene or the like as a standard substance.

[0093] If the polyamide resin (B) has a melting point, the melting point is not particularly limited, but is preferably 150°C or higher, more preferably 160°C or higher, even more preferably 170°C or higher, preferably 350°C or lower, more preferably 300°C or lower, and even more preferably 270°C or lower. The melting point (or softening point) of the polyamide resin (B) may also be equal to or higher than the molding temperature of the composition [for example, the curing temperature of the curable resin (e.g., epoxy resin) as the matrix resin] (or a temperature higher than the molding temperature of the composition).

[0094] The aforementioned resin composition, by containing the modified product (A) and the polyamide resin (B), maintains the transparency of the polyamide resin while exhibiting excellent impact strength over a wide temperature range. The reason why the resin composition exhibits the aforementioned effect is not entirely clear, but it is presumed to be as follows: In the resin composition, it is assumed that the modified product of the hydrogenated block copolymer exists in a dispersed state, and the diffuse reflection of light at these interfaces may cause clouding. By introducing an unsaturated carboxylic acid or its derivative that can chemically react with the resin component into the modified product (A), the dispersion diameter of the modified product is reduced, and the refractive index of the modified product (A) is increased, reducing the difference with the refractive index of the resin component, thereby reducing the degree of light refraction and making it possible to maintain the transparency of the polyamide resin.

[0095] Furthermore, it is believed that the modified material (A) is responsible for energy absorption when an impact is applied. By including a block (x1) containing units derived from a conjugated diene compound that exhibits high molecular chain mobility even at low temperatures, and by introducing an unsaturated carboxylic acid or its derivative that can chemically react with the resin component, it is possible to reduce the dispersion diameter of the modified material and enhance the impact resistance modification effect, thereby improving impact strength over a wide temperature range.

[0096] In the resin composition, it is preferable to include a modified substance (A) in an amount of 2 to 40% by mass and a polyamide resin (B) in an amount of 98 to 60% by mass (provided that the total amount of the modified substance (A) and the polyamide resin (B) is 100% by mass). With respect to the total amount of the modified substance (A) and the polyamide resin (B) of 100% by mass, the content of the modified substance (A) is more preferably 4 to 35% by mass, even more preferably 6 to 30% by mass, even more preferably 7 to 25% by mass, and particularly preferably 8 to 18% by mass, and the content of the polyamide resin (B) is more preferably 96 to 65% by mass, even more preferably 94 to 70% by mass, even more preferably 93 to 75% by mass, and particularly preferably 92 to 82% by mass. By including the modified substance (A) and the polyamide resin (B) in such a ratio, a resin composition can be obtained that maintains the transparency of the polyamide resin while exhibiting excellent impact strength over a wide temperature range.

[0097] <Additives> In addition to the polyamide resin (B) and the modified product (A) of the hydrogenated block copolymer (X), the resin composition may contain additives such as antioxidants, ultraviolet absorbers, photoprotective agents, phosphate-based heat stabilizers, peroxide decomposing agents, basic auxiliary stabilizers, nucleating agents, plasticizers, lubricants, antistatic agents, flame retardants, pigments, dyes, and fillers, to the extent that they do not impair the effects of the present invention. Furthermore, the resin composition may contain other polymers other than the polyamide resin (B) and the modified product (A) of the hydrogenated block copolymer (X), to the extent that they do not impair the effects of the present invention. These additives and other polymers may be one type or two or more types.

[0098] <Physical Properties of the Resin Composition> The lower limit of the refractive index of the resin composition is preferably 1.550 or higher, more preferably 1.555 or higher, even more preferably 1.560 or higher, and particularly preferably 1.565 or higher. On the other hand, the upper limit of the refractive index is not particularly limited, but may be, for example, 1.590 or lower, or 1.580 or lower. The refractive index can be measured by the method described in the examples below.

[0099] The lower limit of the flexural modulus of the resin composition is preferably 1,550 MPa or more, more preferably 1,555 MPa or more, even more preferably 1,560 MPa or more, and particularly preferably 1,565 MPa or more. On the other hand, the upper limit of the flexural modulus is not particularly limited, but may be, for example, 5,000 MPa or less. The flexural modulus can be measured by the method described in the examples below.

[0100] The lower limit of the bending strength of the resin composition is preferably 58 MPa or higher, more preferably 62 MPa or higher, even more preferably 66 MPa or higher, even more preferably 70 MPa or higher, and particularly preferably 72 MPa or higher. On the other hand, the upper limit of the bending strength is not particularly limited, but may be, for example, 100 MPa or lower. The bending strength can be measured by the method described in the examples below.

[0101] The lower limit of the Charpy impact strength (T) of the resin composition at 23°C is preferably 18 kJ / m 2 Above, a comfortable 20 kJ / m³ 2 More preferably 22 kJ / m 2 More preferably, 24 kJ / m 2 In particular, 26 kJ / m is preferred. 2 That concludes the explanation. On the other hand, there is no particular upper limit to the Charpy impact strength (T), but for example, 50 kJ / m 2 The following is also acceptable. Furthermore, the lower limit of the Charpy impact strength (U) of the resin composition at 0°C is preferably 8 kJ / m 2 The above is a more efficient 9 kJ / m 2 More preferably 10 kJ / m 2Furthermore, to make it even more comfortable, 12 kJ / m 2 The above is particularly preferably 14 kJ / m 2 That concludes the explanation. On the other hand, the upper limit of the Charpy impact strength (U) is not particularly limited, but for example, 50 kJ / m 2 The following is also possible. Furthermore, the lower limit of the Charpy impact strength (V) of the resin composition at -40°C is preferably 2.5 kJ / m 2 More preferably, 2.6 kJ / m 2 More preferably, 2.7 kJ / m 2 Furthermore, a more preferable rate is 2.8 kJ / m 2 That concludes the explanation. On the other hand, the upper limit of the Charpy impact strength (V) is not particularly limited, but for example, 5 kJ / m 2 The following may also apply. The Charpy impact strength can be measured by the method described in the embodiments below.

[0102] The balance of Charpy impact strength at 23°C, 0°C, and -40°C is evaluated using the second balance index shown in the following formula (2). Second balance index (kJ / m 2 ) = ([Charpy impact strength with notch at 23°C (T)] × [Charpy impact strength with notch at 0°C (U)] × [Charpy impact strength with notch at -40°C (V)]) 1 / 3 ...Formula (2)

[0103] The lower limit of the second balance index is preferably 6 kJ / m 2 More preferably 7 kJ / m 2 More preferably 8 kJ / m 2 Furthermore, more preferably 9 kJ / m 2 The above is particularly preferably 10 kJ / m 2 More preferably, the value is 11 kJ / m 2 That concludes the explanation. On the other hand, there is no particular upper limit to the second balance index, but for example, 30 kJ / m³ 2 The following is also acceptable. When the second balance index is within the above range, the balance of Charpy impact strength at each temperature is excellent.

[0104] <Method for preparing the resin composition> The resin composition is prepared by melt-mixing a modified product (A) of a hydrogenated block copolymer (X), a polyamide resin (B), and additives as needed, using various conventionally known methods. For example, the resin composition is obtained by simultaneously or sequentially introducing each of the above components into a mixer such as a Henschel mixer, V-type blender, tumbler mixer, or ribbon blender and mixing them, and then melt-kneading the resulting mixture in a melt-kneading device such as a single-screw extruder, multi-screw extruder, kneader, or Banbury mixer. Among these melt-kneading devices, using a device with excellent kneading performance, such as a multi-screw extruder, kneader, or Banbury mixer, will yield a high-quality resin composition in which each component is more uniformly dispersed. Furthermore, the above additives, such as antioxidants, may be added as needed at any stage of mixing or melt-kneading.

[0105] [Molded Article] The molded article according to the present invention is not particularly limited as long as it includes the resin composition, and is a molded article formed using any known molding method depending on the application. Examples of molding methods include injection molding, extrusion molding, compression molding, and foam molding. Injection molding is preferred from the viewpoint of productivity and the ability to easily form complex shapes.

[0106] The upper limit of the total haze of the molded article obtained from the resin composition, as measured in accordance with JIS K7136, is preferably 92% or less, more preferably 90% or less, even more preferably 88% or less, even more preferably 80% or less, particularly preferably 75% or less, and especially preferably 60% or less. On the other hand, the lower limit of the total haze is not particularly limited, but may be, for example, 2% or more. When the total haze of the molded article is 92% or less, the appearance of the molded article becomes transparent. Here, "total haze" refers to haze including haze due to the shape of the outer surface of the molded article.

[0107] The upper limit of the internal haze of the molded article obtained from the resin composition, as measured in accordance with JIS K7136, is preferably 80% or less, more preferably 78% or less, even more preferably 76% or less, even more preferably 74% or less, particularly preferably 70% or less, and especially preferably 60% or less. On the other hand, the lower limit of the internal haze is not particularly limited, but may be, for example, 5% or more. When the internal haze of the molded article is 80% or less, the external appearance of the molded article becomes transparent. Here, "internal haze" refers to the haze excluding the haze caused by the shape of the outer surface of the molded article.

[0108] The balance between the total haze and internal haze is evaluated using the third balance index shown in the following formula (3): Third Balance Index (%) = ((Total Haze (%)) × (Internal Haze (%)) 1 / 2 ...Formula (3) The upper limit of the third balance index is preferably 86% or less, more preferably 84% or less, even more preferably 82% or less, even more preferably 80% or less, particularly preferably 78% or less, and especially preferably 68% or less. On the other hand, the lower limit of the third balance index is not particularly limited, but may be, for example, 5% or more. When the third balance index is 86% or less, there is a good balance between total haze and internal haze.

[0109] The lower limit of the total light transmittance of the molded article obtained from the resin composition, as measured in accordance with JIS K7361, is preferably 40% or more, more preferably 43% or more, even more preferably 46% or more, even more preferably 49% or more, particularly preferably 52% or more, and especially preferably 55% or more. On the other hand, the upper limit of the total light transmittance is not particularly limited, but may be, for example, 100% or less. When the total light transmittance of the molded article is 40% or more, the appearance of the molded article becomes transparent. Here, "total light transmittance" refers to the light transmittance including the influence of the shape of the outer surface of the molded article.

[0110] The lower limit of the internal light transmittance of the molded article obtained from the resin composition, as measured in accordance with JIS K7361, is preferably 35% or more, more preferably 38% or more, even more preferably 41% or more, even more preferably 44% or more, particularly preferably 50% or more, and especially preferably 60% or more. On the other hand, the upper limit of the internal light transmittance is not particularly limited, but may be, for example, 100% or less. When the internal light transmittance of the molded article is 35% or more, the exterior of the molded article becomes transparent. Here, "internal light transmittance" refers to the light transmittance excluding the influence of the shape of the outer surface of the molded article.

[0111] The balance between the total light transmittance and the internal light transmittance is evaluated using the fourth balance index shown in the following formula (4): Fourth balance index (%) = ((Total light transmittance (%)) × (Internal light transmittance (%))) 1 / 2 ...Formula (4) The lower limit of the fourth balance index is preferably 40% or more, more preferably 43% or more, even more preferably 46% or more, even more preferably 49% or more, particularly preferably 55% or more, and especially preferably 60% or more. On the other hand, the upper limit of the fourth balance index is not particularly limited, but may be, for example, 100% or less. When the fourth balance index is 40% or more, there is an excellent balance between the total light transmittance and the internal light transmittance.

[0112] The molded articles can be used in food products, daily necessities, toys and sporting goods, stationery, automotive interior and exterior applications, civil engineering and construction applications, home appliance applications, clothing and footwear applications, medical applications, hygiene products, packaging and transport materials, and electric wire applications, among others. Among these, they are widely used in the automotive, electrical and electronic, and industrial parts sectors. Examples of industrial articles include battery cases, oil gauges, and breaker housings. Examples of daily necessities include eyeglass lenses, eyeglass frames, sunglasses, and goggles. They are particularly suitable for use in eyeglass frames or watch band components.

[0113] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples. The materials, amounts used, proportions, and processing procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention.

[0114] <Hydrogenated Block Copolymer (X)> 1. Hydrogenated Block Copolymer (X-1) Asahi Kasei Corporation S.O.E. (Registered Trademark) S1605 (Styrene polymer block - Hydrogenated styrene-butadiene random copolymer block - Styrene polymer block), Content of units derived from vinyl aromatic compounds (hereinafter also referred to as "vinyl aromatic compound content"): 66% by mass, MFR (according to ASTM D1238, 230°C, 2.16 kg load): 3.5 g / 10 min, Density: 1,000 kg / m³ 3 ) was used. 2. Hydrogenated block copolymer (X-2) Asahi Kasei Corporation S.O.E. (registered trademark) S1606 (styrene polymer block - hydrogenated styrene-butadiene random copolymer block - styrene polymer block, vinyl aromatic compound content: 50% by mass, MFR (according to ASTM D1238, 230℃, 2.16 kg load): 4 g / 10 min, density: 960 kg / m³ 3 ) was used. 3. Hydrogenated block copolymer (X-3) Asahi Kasei Corporation's ToughTec (registered trademark) H1043 (styrene polymer block - hydrogenated styrene-butadiene random copolymer block, refractive index: 1.548, vinyl aromatic compound content: 67% by mass, MFR (according to ASTM D1238, 230℃, 2.16 kg load): 2 g / 10 min, density: 970 kg / m³ 3 ) was used.

[0115] 4. Content (mass%) of units derived from vinyl aromatic compounds relative to the total mass of hydrogenated block copolymer (X) Proton nuclear magnetic resonance ( 1The vinyl aromatic compound content was measured by 1H-NMR. Specifically, a JNM-LA400 (JEOL) was used as the measuring instrument, deuterated chloroform as the solvent, and tetramethylsilane as the chemical shift standard. The measurement was performed at a sample concentration of 50 mg / mL, an observation frequency of 400 MHz, a pulse delay of 2.904 seconds, 64 scans, a pulse width of 45°, and a measurement temperature of 26°C. The vinyl aromatic compound content was calculated using the integrated value of the total styrene aromatic signal in the spectrum from 6.2 to 7.5 ppm.

[0116] 5. Hydrogenation rate (mol%) of hydrogenated block copolymer (X) Using the same apparatus and conditions as in the measurement of the vinyl aromatic compound content above, 1 1H-NMR spectra were obtained. The hydrogenation rate was calculated by determining the integral value of the signal originating from the remaining double bond and the signal originating from the hydrogenated conjugated diene in the spectrum from 4.5 to 5.5 ppm, and then taking the ratio of these values.

[0117] <Modified product (A) of hydrogenated block copolymer (X)> [Example A1] 10 kg of a mixture consisting of 60% by mass of hydrogenated block copolymer (X-1) and 40% by mass of hydrogenated block copolymer (X-2) was blended with 120 g of maleic anhydride (MAH) and a solution of 6 g of 2,5-dimethyl-2,5-di-(t-butylperoxy)-3-hexine (trade name: Perhexine 25B) dissolved in acetone. The resulting blend was then fed into the hopper of a twin-screw extruder with a screw diameter of 30 mm and an L / D ratio of 42, and extruded in strand form at a resin temperature of 250°C, a screw rotation speed of 180 rpm, and a discharge rate of 10 kg / hr. After the obtained strand was sufficiently cooled, it was granulated to obtain modified product (A-1) of hydrogenated block copolymer. The results of the physical property measurement of the obtained modified product (A-1) of hydrogenated block copolymer are shown in Table 1.

[0118] [Examples A2, A4-A5, and Comparative Examples A6-A7] Modified products (A-2) and (A-4) to (A-7) of the hydrogenated block copolymer (X) were obtained in the same manner as in Example A1, except that the composition ratios of hydrogenated block copolymers (X-1) and (X-2) were as shown in Table 1. The results of the physical property measurements of the obtained modified products (A-2) and (A-4) to (A-7) are shown in Table 1.

[0119] [Example A3 and Comparative Example A8] Modified hydrogenated block copolymers (A-3) and (A-8) were obtained in the same manner as in Example A1, except that the amount of maleic anhydride (MAH) added was changed to 80 g, the amount of 2,5-dimethyl-2,5-di-(t-butylperoxy)-3-hexine added was changed to 4 g, and the composition ratio of hydrogenated block copolymers (X-1) to (X-3) was as shown in Table 1. The results of the physical property measurements of the obtained modified products (A-3) and (A-8) are shown in Table 1.

[0120] 《Content (mass%) of units derived from vinyl aromatic compounds relative to the total mass of modified product (A) of hydrogenated block copolymer (X)》 Proton nuclear magnetic resonance ( 1 The vinyl aromatic compound content was measured by ¹H-NMR. Specifically, the measuring instrument was AVANCE III (Bruker), and the solvent was 1,1,2,2-tetrachloroethane-d ２ The measurement was performed using 1,1,2,2-tetrachloroethane as the chemical shift reference, with a sample concentration of 20 mg / 0.6 mL, an observation frequency of 500 MHz, 64 scans, a pulse width of 45°, and a measurement temperature of 120°C. The vinyl aromatic compound content was calculated using the integrated value of the total styrene signal in the spectrum from 6.2 to 7.5 ppm. As a pretreatment of the measurement sample, the sample was dissolved and held at 250°C for 5 minutes using a hot press, and then cooled and solidified at room temperature.

[0121] 《Content (mass%) of the modifying agent (units derived from unsaturated carboxylic acid or its derivatives) relative to the total mass of the modified product (A) of the hydrogenated block copolymer (X)》 Wavenumber 1780 cm⁻¹ assigned to the carbonyl group of the modified product (A) of the hydrogenated block copolymer (X) by FT-IR -1Based on the peak intensity, the amount of denaturation was determined from a calibration curve created separately.

[0122] <Evaluation of Physical Properties of Modified Product (A) of Hydrogenated Block Copolymer (X)> Modified products (A-1) to (A-8) obtained in the examples and comparative examples were pressure-formed into sheets at 7.5 MPa using a hydraulic hot press manufactured by Shinto Metal Industries Co., Ltd. set to 190°C. After preheating without load for 5 minutes, the sheets were pressurized at 7.5 MPa for 2 minutes, then compressed at 7.5 MPa using another hydraulic hot press manufactured by Shinto Metal Industries Co., Ltd. set to 20°C, and cooled for 5 minutes to prepare samples for measurement. A 5 mm thick brass plate was used as the heating plate. The samples prepared by the above method were used for the following various physical property evaluation samples.

[0123] 《MFR (g / 10 min)》 The melt flow rate (MFR) was measured in accordance with ASTM D1238 under conditions of 230°C and a 2.16 kg load.

[0124] 《Density (kg / m 3 The density of the strand resin that leaked out during the MFR measurement described above was measured using the density gradient pipe method in accordance with ASTM D1505.

[0125] 《Refractive Index》 Using a 0.5 mm thick test specimen prepared by the method described above, the refractive index (D line, 589 nm, 23°C) was measured in accordance with JIS K7142 using an Abbe refractometer (instrument name: DR-M2, manufactured by Atago Corporation). Methylene iodide was used as an intermediate solution for the measurement, and the measurement was performed in the thickness direction of the test specimen.

[0126] 《Tensile Breaking Stress (R) and Tensile Breaking Elongation (S)》 Using a 2 mm thick press sheet prepared by the method described above, dumbbell-shaped test specimens were prepared in accordance with JIS K7161. Tensile tests were conducted using an Instron 3380 universal tensile testing machine under the conditions of a tensile speed of 50 mm / min and a measurement temperature of 23°C, and the tensile breaking stress (R) and tensile breaking elongation (S) were measured.

[0127] 《Balance between tensile fracture stress (R) and tensile fracture elongation (S)》 The following formula (1) was created as an index (first balance index) to show the balance between tensile fracture stress (R) and tensile fracture elongation (S). First balance index = (tensile fracture stress (R) [MPa] × tensile fracture elongation (S) [%]) / 100 ... Formula (1) The balance between tensile fracture stress (R) and tensile fracture elongation (S) was calculated using the above first balance index.

[0128]

[0129] <Resin Composition> Polyamide resin (B-1) (PA6 / 3T polyamide, manufactured by Daicel Evonik, Trogamid® T5000, heat distortion temperature (load 1.8 MPa): 130°C, density: 1,120 kg / m³) 3 A polyamide resin (refractive index: 1.57) was used. The refractive index of polyamide resin (B-1) was measured using an Abbe refractometer (device name: DR-M2, manufactured by Atago Co., Ltd.) in accordance with JIS K7142, using a 2 mm thick square plate injection-molded at 270°C in the cylinder and 80°C in the mold, to obtain the refractive index (D line, 589 nm, 23°C). Methylene iodide was used as the intermediate liquid. Measurements were taken in the thickness direction of the test piece.

[0130] [Example P1] 90 parts by mass of polyamide resin (B-1) and 10 parts by mass of a modified hydrogenated block copolymer (X) (A-1) were mixed using a Henschel mixer to prepare a dry blend. Next, this dry blend was supplied to a twin-screw extruder (L / D = 42, 30 mmφ) set to 270°C to prepare resin composition pellets. The obtained resin composition pellets were dried at 80°C for 12 hours, and then injection molded under the following conditions to produce test specimens for physical property testing. (Injection molding conditions) Cylinder temperature: 270°C Injection pressure: 400 kg / cm 2 Mold temperature: 80°C

[0131] Next, the physical properties of the polyamide resin composition were evaluated using the method described below. The results are shown in Table 2.

[0132] Refractive Index: A 2 mm thick square plate, injection-molded at 270°C in the cylinder and 80°C in the mold, was used to measure the refractive index (D-line, 589 nm, 23°C) using an Abbe refractometer (device name: DR-M2, manufactured by Atago Corporation) in accordance with JIS K7142. Methylene iodide was used as an intermediate solution for the measurement, and measurements were taken in the thickness direction of the test piece.

[0133] 《Tensile Yield Stress》 Using ISO dumbbell test specimens injected using the method described above and cured for 3 days at 23°C and 50% humidity, tensile tests were performed at a speed of 50 mm / min according to ISO 527-1 and ISO 527-2, and the tensile yield stress was measured.

[0134] 《Flexural Modulus and Bending Strength》 Using samples of the body of an ISO dumbbell test specimen, which was injection molded using the method described above, and cured at 23°C and 50% humidity for 3 days, the flexural modulus and bending strength were measured according to ISO 178.

[0135] 《Charpy Impact Strength》 Using samples of ISO dumbbell test pieces injected using the method described above, the body was cured at 23°C and 50% humidity for 3 days. The Charpy impact strength of notched dumbbells was measured at -40°C, 0°C, and 23°C according to ISO 179.

[0136] Balance of Charpy impact strength at each measurement temperature: Notched Charpy impact strength (kJ / m) at 23°C, 0°C, and -40°C. 2 As an indicator showing the balance of (second balance indicator), the following formula (2) was created. Second balance indicator (kJ / m 2 ) = ([Charpy impact strength with notch at 23°C (T)] × [Charpy impact strength with notch at 0°C (U)] × [Charpy impact strength with notch at -40°C (V)]) 1 / 3 ...Equation (2) The second balance index above is used to determine the notched Charpy impact strength (kJ / m) at 23°C, 0°C, and -40°C. 2 The balance of ) was calculated.

[0137] Transparency (Total Haze (W)) Using a 2 mm thick rectangular plate test specimen injection-molded by the method described above, and using a D65 light source, the total haze (W) was measured in accordance with JIS K7136. (Internal Haze (X)) Using a 2 mm thick rectangular plate test specimen injection-molded by the method described above, and using a D65 light source, the internal haze (X) was measured in accordance with JIS K7136. Cyclohexanol was used as the immersion solvent.

[0138] (Balance between total haze (W) and internal haze (X)) The following formula (3) was created as an indicator (third balance indicator) showing the balance between total haze (W) and internal haze (X). Third balance indicator (%) = ((Total haze (W) [%]) × (Internal haze (X) [%])) 1 / 2 ...Equation (3) The balance between total haze (W) and internal haze (X) was calculated using the above third balance index.

[0139] (Total light transmittance (Y)) Using a 2 mm thick rectangular plate test specimen injection-molded by the method described above, the total light transmittance (Y) was measured in accordance with JIS K7361-1, using the same apparatus and conditions as those used for measuring the total haze (W) described above. (Internal light transmittance (Z)) Using a 2 mm thick rectangular plate test specimen injection-molded by the method described above, and using D65 as the light source, the internal light transmittance (Z) was measured in accordance with JIS K7361-1. Cyclohexanol was used as the immersion solvent.

[0140] (Balance between total light transmittance (Y) and internal light transmittance (Z)) The following formula (4) was created as an index (fourth balance index) that shows the balance between total light transmittance (Y) and internal light transmittance (Z). Fourth balance index (%) = ((Total light transmittance (Y) [%]) × (Internal light transmittance (Z) [%])) 1 / 2 ...Equation (4) The balance between total light transmittance (Y) and internal light transmittance (Z) was calculated using the above fourth balance index.

[0141] [Examples P2 to P6, Comparative Examples P7 to P9] Resin compositions were prepared in the same manner as in Example P1, except that the composition ratio of the polyamide resin (B) and the modified product (A) of the hydrogenated block copolymer (X) was changed as shown in Table 2. The results of the physical property measurements are shown in Table 2.

[0142] [Reference Example 1] This example was prepared in the same manner as in Example P1, except that only polyamide resin (B) was used. The results of the physical property measurements are shown in Table 2.

[0143]

[0144] The disclosure of Japanese Patent Application No. 2025-006452, filed on 16 January 2025, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted to be incorporated by reference.

Claims

1. A modified product (A) of a hydrogenated block copolymer (X), wherein the modifier of the modified product (A) is an unsaturated carboxylic acid or a derivative thereof, the hydrogenated block copolymer (X) is a hydrogenated product of a block copolymer (x) comprising a block (x1) containing more than 30% by mass of units derived from a conjugated diene compound and a block (x2) containing more than 70% by mass of units derived from a vinyl aromatic compound, and the content of units derived from the vinyl aromatic compound relative to the total mass of the modified product (A) is 52.0 to 64.5% by mass.

2. The modified product (A) according to claim 1, wherein the block (x1) is a copolymer block (x1-a) further containing units derived from a vinyl aromatic compound.

3. The modified product (A) according to claim 2, wherein the hydrogenated block copolymer (X) is a triblock copolymer consisting of a styrene polymer block, a hydrogenated styrene-butadiene random copolymer block, and a styrene polymer block.

4. Modified product (A) according to claim 1 or 2, wherein the hydrogenated block copolymer (X) is a mixture comprising 40 to 95% by mass of a hydrogenated block copolymer (X-1) satisfying the following requirement (1), and 60 to 5% by mass of a hydrogenated block copolymer (X-2) satisfying the following requirement (2) (provided that the total amount of the block copolymers (X-1) and (X-2) is 100% by mass). Requirement (1): The content of units derived from the vinyl aromatic compound relative to the total mass of the block copolymer (X-1) is greater than 59% by mass and 75% by mass or less. Requirement (2): The content of units derived from the vinyl aromatic compound relative to the total mass of the block copolymer (X-2) is 43 to 59% by mass.

5. The modified product (A) according to claim 1 or 2, wherein the content of units derived from the vinyl aromatic compound relative to the total mass of the modified product (A) is 54.0% by mass or more and less than 62.0% by mass.

6. The modified product (A) according to claim 1 or 2, wherein the content of units derived from the vinyl aromatic compound relative to the total mass of the modified product (A) is 56.0 to 64.5% by mass.

7. The modified product (A) according to claim 1 or 2, wherein the content of units derived from the vinyl aromatic compound relative to the total mass of the modified product (A) is 56.0% by mass or more and less than 62.0% by mass.

8. The modified product (A) according to claim 1 or 2, wherein the content of units derived from the vinyl aromatic compound relative to the total mass of the modified product (A) is 56.0 to 64.5% by mass, and the hydrogenated block copolymer (X) is a triblock copolymer consisting of a styrene polymer block, a hydrogenated styrene-butadiene random copolymer block, and a styrene polymer block.

9. The modified product (A) according to claim 1 or 2, wherein the MFR (at 230°C, with a 2.16 kg load) of the modified product (A) is 35 g / 10 min or less.

10. The modified product (A) according to claim 1 or 2, wherein the content of units derived from an unsaturated carboxylic acid or its derivative, relative to the total mass of the modified product (A), is 0.05 to 10.0% by mass.

11. The modified product (A) according to claim 1 or 2, wherein the content of units derived from an unsaturated carboxylic acid or its derivative, relative to the total mass of the modified product (A), is 0.05 to 1.0% by mass.

12. The modified product (A) according to claim 1 or 2, wherein the content of units derived from an unsaturated carboxylic acid or its derivative, relative to the total mass of the modified product (A), is 0.05 to 1.0% by mass, and the content of units derived from the vinyl aromatic compound, relative to the total mass of the modified product (A), is 56.0 to 64.5% by mass.

13. The modified product (A) according to claim 1 or 2, wherein the content of units derived from an unsaturated carboxylic acid or its derivative, relative to the total mass of the modified product (A), is 0.05 to 1.0% by mass, and the hydrogenated block copolymer (X) is a triblock copolymer consisting of a styrene polymer block, a hydrogenated styrene-butadiene random copolymer block, and a styrene polymer block.

14. The modified product (A) according to claim 1 or 2, wherein the refractive index of the modified product (A) is 1.549 or greater.

15. The modified material (A) according to claim 1 or 2, wherein the refractive index of the modified material (A) is 1.549 or greater, and when the balance between the tensile fracture stress and the tensile fracture elongation of the modified material (A) is expressed as a first balance index shown in the following formula (1), the first balance index is 90 or greater. First balance index = (Tensile fracture stress (MPa) × Tensile fracture elongation (%)) / 100 ... Formula (1) 16. Modified product (A) according to claim 1 or 2, for modifying polyamide resin having a refractive index of 1.543 or higher.

17. A resin composition comprising a modified product (A) of a hydrogenated block copolymer (X) according to claim 1 or 2, and a polyamide resin (B).

18. The resin composition according to claim 17, wherein the hydrogenated block copolymer (X) is a triblock copolymer consisting of a styrene polymer block, a hydrogenated styrene-butadiene random copolymer block, and a styrene polymer block.

19. The resin composition according to claim 17, wherein the refractive index of the resin composition is 1.550 or higher.

20. The resin composition according to claim 17, comprising the modified substance (A) in an amount of 2 to 40% by mass and the polyamide resin (B) in an amount of 98 to 60% by mass (provided that the total amount of the modified substance (A) and the polyamide resin (B) is 100% by mass).

21. The resin composition according to claim 17, wherein the content of units derived from an unsaturated carboxylic acid or its derivative, relative to the total mass of the modified product (A), is 0.05 to 10.0% by mass.

22. A molded article comprising the resin composition described in claim 17.

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