Composition

Abstract

A composition comprising a block copolymer, an antioxidant (I), an antioxidant (II), and an antioxidant (III), wherein: the block copolymer includes a polymer block (a) including a structural unit derived from an aromatic vinyl compound and a polymer block (b) including a structural unit derived from a conjugated diene compound; the antioxidant (I) is a compound represented by general formula (1); the antioxidant (II) is a compound (excluding the antioxidant (I)) including a sulfur atom; the antioxidant (III) is a compound (excluding the antioxidant (I) and the antioxidant (II)) including a hydroxyphenyl group and at least one selected from an acryloyl group and a methacryloyl group; the content of the antioxidant (I) is 0.01-1.00 part by mass with respect to 100 parts by mass of the block copolymer; the content of the antioxidant (II) is 0.05-1.00 part by mass with respect to 100 parts by mass of the block copolymer; and the content of the antioxidant (III) is 0.05-1.00 part by mass with respect to 100 parts by mass of the block copolymer.

Description

composition

[0001] This invention relates to a composition.

[0002] It is already known that copolymers containing polymer blocks with structural units derived from aromatic vinyl compounds, such as styrene elastomers, and polymer blocks containing structural units derived from conjugated diene compounds exhibit excellent vibration damping and reactivity. These copolymers are used in various fields, and their development is actively underway.

[0003] For example, Patent Document 1 describes a block copolymer containing aromatic vinyl monomer units and conjugated diene monomer units, a composition containing three types of antioxidants having a predetermined structure, and an adhesive composition containing the composition.

[0004] Japanese Patent Publication No. 2020-117663

[0005] Copolymers containing polymer blocks with structural units derived from aromatic vinyl compounds and polymer blocks with structural units derived from conjugated diene compounds have the advantage of excellent vibration damping and reactivity. However, because these copolymers have a high vinyl bond content, they are prone to deterioration over time and have low storage stability. Therefore, there has been a need for a method to suppress deterioration over time in these copolymers and improve their storage stability.

[0006] The present invention has been made in view of the above circumstances, and aims to provide a composition with excellent storage stability in which the deterioration over time of a block copolymer comprising a polymer block (a) containing structural units derived from an aromatic vinyl compound and a polymer block (b) containing structural units derived from a conjugated diene compound is suppressed.

[0007] As a result of diligent research by the present inventors, we have found that the above problems can be solved by providing a composition containing a block copolymer comprising a polymer block (a) containing structural units derived from an aromatic vinyl compound and a polymer block (b) containing structural units derived from a conjugated diene compound, and a predetermined amount of antioxidants (I) to (III) having a specific structure, which led to the present invention. That is, the present invention is as follows. [1] A composition comprising a block copolymer, an antioxidant (I), an antioxidant (II), and an antioxidant (III), wherein the block copolymer comprises a polymer block (a) containing structural units derived from an aromatic vinyl compound and a polymer block (b) containing structural units derived from a conjugated diene compound, the antioxidant (I) is a compound represented by the following general formula (1), the antioxidant (II) is a compound containing a sulfur atom (except for antioxidant (I)), the antioxidant (III) is a compound comprising at least one selected from an acryloyl group and a methacryloyl group and a hydroxyphenyl group (except for antioxidant (I) and antioxidant (II)), the content of antioxidant (I) is 0.01 to 1.00 parts by mass per 100 parts by mass of the block copolymer, and the content of antioxidant (II) is 0.05 to 1.00 parts by mass per 100 parts by mass of the block copolymer. A composition wherein the content of the aforementioned antioxidant (III) is 0.05 to 1.00 parts by mass per 100 parts by mass of the block copolymer. (In formula (1), R １ , R ２ , and R ４ One of the selected R groups is a methyl group, and R is not a methyl group. １ ~R ４ One of the selected groups is an organic group, and the methyl group and R which is not an organic group １ ~R ４Two of the atoms selected from are hydrogen atoms.) [2] The composition according to [1], wherein the amount of vinyl bond in the polymer block (b) is 30 to 80 mol%. [3] The composition according to [1] or [2], wherein the weight-average molecular weight of the block copolymer is 40,000 to 500,000. [4] The composition according to any one of [1] to [3], wherein the content of polymer block (a) in the block copolymer is 1 to 50% by mass. [5] The composition according to any one of [1] to [4], wherein the block copolymer is a triblock copolymer. [6] The composition according to any one of [1] to [5], wherein the conjugated diene compound is isoprene. [7] In formula (1), the R １The composition according to any one of [1] to [6] above, wherein is a methyl group. [8] The composition according to any one of [1] to [7] above, wherein the hydrogenation rate of the block copolymer is 20 mol% or less. [9] The composition according to any one of [1] to [8] above, wherein the organic group in formula (1) comprises a hydroxyphenyl group.

[10] The composition according to [9] above, wherein in the hydroxyphenyl group, one of the two ortho positions of the hydroxyl group bonded to the benzene ring is substituted with a t-butyl group.

[11] The composition according to any one of [1] to

[10] above, wherein the antioxidant (II) is a compound comprising at least one selected from a thioether bond (-S-), a thioester bond (-S-C(=O)-), a sulfinyl group (-S(=O)-), and a thiol group (-SH).

[12] The composition according to any one of [1] to

[11] , wherein in the hydroxyphenyl group contained in the antioxidant (III), at least one of the two ortho positions of the hydroxyl group bonded to the benzene ring is substituted with an organic group having 2 or more carbon atoms.

[13] The composition according to any one of [1] to

[12] , wherein the total content of the antioxidant (I), the antioxidant (II), and the antioxidant (III) is 0.11 to 3.00 parts by mass per 100 parts by mass of the block copolymer.

[14] The composition according to any one of claims [1] to

[13] , wherein the content of the antioxidant (I) is 0.05 to 0.50 parts by mass per 100 parts by mass of the block copolymer, the content of the antioxidant (II) is 0.10 to 0.50 parts by mass per 100 parts by mass of the block copolymer, and the content of the antioxidant (III) is 0.10 to 0.50 parts by mass per 100 parts by mass of the block copolymer.

[15] The composition according to any one of claims [1] to

[114] , which is used as at least one selected from home appliances, electronic components, building materials, automobile parts, sporting goods, medical products, shoes, adhesives, coatings, and sealing materials.

[0008] According to the present invention, it is possible to provide a composition with excellent storage stability in which the deterioration of a block copolymer over time is suppressed, and which comprises a polymer block (a) containing structural units derived from an aromatic vinyl compound and a polymer block (b) containing structural units derived from a conjugated diene compound.

[0009] The following description is based on an example of an embodiment of the present invention. However, the embodiments shown below are illustrative examples for realizing the technical concept of the present invention, and the present invention is not limited to the following description. In this specification, preferred forms of embodiments are shown, but combinations of two or more individual preferred forms are also preferred forms. If there are several numerical ranges for matters indicated by numerical ranges, a preferred form can be obtained by selectively combining their lower and upper limits. Also, when a numerical range is described as "XX to YY", it means "XX or more and YY or less". In this specification, the "weight-average molecular weight (Mw)", "number-average molecular weight (Mn)", and "molecular weight distribution (Mw / Mn)" of the block copolymer and each polymer block refer to the weight-average molecular weight (Mw), number-average molecular weight (Mn), and molecular weight distribution (Mw / Mn) on a standard polystyrene basis, determined by gel permeation chromatography (GPC) measurement, and more specifically, the values ​​measured according to the method described in the examples.

[0010] [Composition] The composition of the present embodiment is a composition comprising a block copolymer, an anti-aging agent (I), an anti-aging agent (II), and an anti-aging agent (III), wherein the block copolymer comprises a polymer block (a) containing a structural unit derived from an aromatic vinyl compound and a polymer block (b) containing a structural unit derived from a conjugated diene compound, the anti-aging agent (I) is a compound represented by the following general formula (1), the anti-aging agent (II) is a compound containing a sulfur atom (excluding anti-aging agent (I)), the anti-aging agent (III) is a compound containing at least one selected from the group consisting of an acryloyl group and a methacryloyl group, and a hydroxyphenyl group (excluding the anti-aging agent (I) and the anti-aging agent (II)), the content of the anti-aging agent (I) is 0.01 to 1.00 parts by mass based on 100 parts by mass of the block copolymer, the content of the anti-aging agent (II) is 0.05 to 1.00 parts by mass based on 100 parts by mass of the block copolymer, and the content of the anti-aging agent (III) is 0.05 to 1.00 parts by mass based on 100 parts by mass of the block copolymer.

[0011] (In formula (1), R １ , R ２ , and R ４ one selected from is a methyl group, and R which is not the methyl group １ to R ４ one selected from is an organic group, and R which is neither the methyl group nor the organic group １ to R ４ two selected from are hydrogen atoms.)

[0012] <Block Copolymer> The block copolymer in the present embodiment comprises a polymer block (a) containing a structural unit derived from an aromatic vinyl compound and a polymer block (b) containing a structural unit derived from a conjugated diene compound.

[0013] The weight-average molecular weight (Mw) of the block copolymer is preferably 40,000 or more, more preferably 60,000 or more, and even more preferably 80,000 or more, from the viewpoint of the mechanical strength of the block copolymer, and preferably 500,000 or less, more preferably 400,000 or less, and even more preferably 300,000 or less, from the viewpoint of the processability of the block copolymer. The weight-average molecular weight (Mw) of the block copolymer is preferably 40,000 to 500,000, more preferably 60,000 to 400,000, and even more preferably 80,000 to 300,000.

[0014] The molecular weight distribution (Mw / Mn) of the block copolymer is preferably 1.00 or higher, may be 1.10 or higher, or 1.15 or higher. Preferably it is 4.00 or lower, more preferably 3.00 or lower, even more preferably 2.00 or lower, even more preferably 1.50 or lower, even more preferably 1.30 or lower, and even more preferably 1.25 or lower. The molecular weight distribution (Mw / Mn) of the block copolymer is preferably 1.00 to 4.00, more preferably 1.00 to 3.00, even more preferably 1.00 to 2.00, even more preferably 1.00 to 1.50, and even more preferably 1.10 to 1.25. When the molecular weight distribution is within the above range, the mechanical strength of the block copolymer is high. It may also be 1.10 to 3.00, 1.10 to 2.00, 1.15 to 1.50, or 1.15 to 1.30.

[0015] The melt flow rate (MFR) of the block copolymer is preferably 10.0 g / 10 min or less, more preferably 6.0 g / 10 min or less, preferably 0.5 g / 10 min or more, and preferably 1.0 g / 10 min or more. When the melt flow rate (MFR) is within the above range, the block copolymer is easy to handle. The melt flow rate (MFR) of the block copolymer is preferably 0.5 to 10.0 g / 10 min, more preferably 1.0 to 6.0 g / 10 min. In this specification, the "melt flow rate (MFR)" is the value measured under conditions of 190°C and a load of 2.16 kg in accordance with JIS K7210:1999.

[0016] The block copolymer may be an unmodified block copolymer or a modified block copolymer in which a functional group has been introduced. Examples of functional groups that can be introduced include amino groups, alkoxysilyl groups, hydroxyl groups, epoxy groups, carboxyl groups, carbonyl groups, mercapto groups, isocyanate groups, chloro groups, and acid anhydrides.

[0017] The hydrogenation rate of the block copolymer is preferably 20 mol% or less, more preferably 10 mol% or less, even more preferably 5 mol% or less, and may be 0 mol% from the viewpoint of reactivity. The hydrogenation rate of the block copolymer is preferably 0 to 20 mol%, more preferably 0 to 10 mol%, and even more preferably 0 to 5 mol%. The hydrogenation rate of the block copolymer indicates the proportion of carbon-carbon double bonds in the block copolymer that are converted to saturated bonds by hydrogenation. １ It is calculated by comparing the 1H-NMR spectra. Specifically, the hydrogenation rate is calculated by subtracting the peak area of ​​the carbon-carbon double bond after hydrogenation from the peak area of ​​the carbon-carbon double bond before hydrogenation, dividing the result by the peak area of ​​the carbon-carbon double bond before hydrogenation, and multiplying the result by 100.

[0018] (Polymer block (a)) Polymer block (a) contains structural units derived from an aromatic vinyl compound. Examples of the aromatic vinyl compound include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, 4-t-butylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 2,4,6-trimethylstyrene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, 1-vinylnaphthalene, 2-vinylnaphthalene, vinylanthracene, N,N-diethyl-4-aminoethylstyrene, vinylpyridine, 4-methoxystyrene, monochlorostyrene, dichlorostyrene, and divinylbenzene. These aromatic vinyl compounds may be used individually or in combination of two or more. Among these, at least one selected from styrene, α-methylstyrene, and 4-methylstyrene is preferred, with styrene being more preferred. The content of structural units derived from the aromatic vinyl compound in polymer block (a) is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and may be 100% by mass. The content of structural units derived from the aromatic vinyl compound in polymer block (a) is preferably 70 to 100% by mass, more preferably 80 to 100% by mass, even more preferably 85 to 100% by mass, even more preferably 90 to 100% by mass, and even more preferably 95 to 100% by mass.

[0019] As long as it does not hinder the objectives and effects of the present invention, polymer block (a) may or may not contain structural units derived from compounds other than aromatic vinyl compounds. Examples of such other compounds include butadiene, isoprene, 2,3-dimethylbutadiene, 1,3-pentadiene, 1,3-hexadiene, isobutylene, methyl methacrylate, methyl vinyl ether, N-vinylcarbazole, β-pinene, 8,9-p-menthene, dipentene, methylenenorbornene, and 2-methylenetetrahydrofuran. When polymer block (a) contains structural units derived from such other compounds, the bonding configuration is not particularly limited and may be random or tapered. The content of structural units derived from such other compounds in polymer block (a) is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less, even more preferably 10% by mass or less, and even more preferably 5% by mass or less, and may be 0% by mass. The content of structural units derived from the other compound in polymer block (a) is preferably 0 to 30% by mass, more preferably 0 to 20% by mass, even more preferably 0 to 15% by mass, even more preferably 0 to 10% by mass, and even more preferably 0 to 5% by mass.

[0020] The weight-average molecular weight (Mw) of polymer block (a) is preferably 5,000 or more, more preferably 7,000 or more, even more preferably 9,000 or more, and even more preferably 15,000 or more, from the viewpoint of the mechanical strength of the block copolymer, and preferably 60,000 or less, more preferably 50,000 or less, even more preferably 40,000 or less, and even more preferably 30,000 or less, from the viewpoint of the processability of the block copolymer. The weight-average molecular weight (Mw) of polymer block (a) is preferably 5,000 to 60,000, more preferably 7,000 to 50,000, even more preferably 9,000 to 40,000, and even more preferably 15,000 to 30,000. If the block copolymer has two or more polymer blocks (a), the weight-average molecular weight (Mw) of the polymer blocks (a) is the sum of the weights of each polymer block (a).

[0021] The weight average molecular weight (Mw) of the polymer block (a) can be determined by measuring the sampled solution each time the polymerization of each polymer block is completed in the production process. For example, when a triblock copolymer having an a1-b-a2 structure is synthesized by sequential polymerization in the order of a1, b, and a2, the weight average molecular weight (Mw) of the first polymer block (a1) can be determined by performing GPC measurement on a solution sampled when the polymerization of the polymer block (a1) is completed. In addition, the weight average molecular weight (Mw) of the polymer block (a2) can be obtained by performing GPC measurement on a solution sampled when the polymerization of the polymer block (a2) is completed to obtain the weight average molecular weight (Mw) of the triblock copolymer having the a1-b-a2 structure, and then subtracting the weight average molecular weight (Mw) of the diblock copolymer having the a1-b structure from the obtained value.

[0022] From the viewpoint of mechanical strength, the content of the polymer block (a) in the block copolymer is preferably 1% by mass or more, more preferably 5% by mass or more, and still more preferably 10% by mass or more; from the viewpoint of processability, it is preferably 50% by mass or less, more preferably 40% by mass or less, and still more preferably 30% by mass or less. The content of the polymer block (a) in the block copolymer is preferably 1 to 50% by mass, more preferably 5 to 40% by mass, and still more preferably 10 to 30% by mass. The content of the polymer block (a) in the block copolymer is that of the block copolymer １ In the 1H-NMR spectrum, it is calculated by dividing the peak intensity derived from the polymer block (a) by the sum of the peak intensities derived from the polymer block (a), the polymer block (b), and the polymer block (c) described below, and then multiplying the obtained value by 100.

[0023] The block copolymer only needs to have at least one polymer block (a). When the block copolymer has two or more polymer blocks (a), these polymer blocks (a) may be the same or different. The statement that a plurality of polymer blocks (a) contained in the block copolymer are different means that when the polymer block (a) has one type of structural unit, at least one of the weight-average molecular weight (Mw) and stereoregularity of the structural units constituting the polymer block (a) is different. When the polymer block (a) has a plurality of types of structural units, it means that at least one of the ratio of each structural unit and the mode of copolymerization (random, tapered, block) is different. From the viewpoint of mechanical strength, the block copolymer preferably has two polymer blocks (a), and these polymer blocks (a) are preferably the same.

[0024] (Polymer Block (b)) The polymer block (b) contains a structural unit derived from a conjugated diene compound. Examples of the conjugated diene compound include butadiene, isoprene, 2,3-dimethylbutadiene, 2-phenyl-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 1,3-octadiene, 1,3-cyclohexadiene, 2-methyl-1,3-octadiene, 1,3,7-octatriene, myrcene, farnesene, chloroprene, and the like. These may be used alone in one type or in combination of two or more types. Farnesene may be α-farnesene or β-farnesene, and is preferably β-farnesene. Among these, at least one conjugated diene compound selected from the group consisting of butadiene, isoprene, myrcene, and farnesene is preferred, at least one conjugated diene compound selected from the group consisting of butadiene and isoprene is more preferred, and isoprene is even more preferred.

[0025] The content of structural units derived from the conjugated diene compound in polymer block (b) is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass or more, and may be 100% by mass. The content of structural units derived from the conjugated diene compound in polymer block (b) is preferably 60 to 100% by mass, more preferably 70 to 100% by mass, even more preferably 80 to 100% by mass, and even more preferably 90 to 100% by mass. The content of polymer block (b) in the block copolymer is １ In the H-NMR spectrum, the peak intensity originating from polymer block (b) is calculated by dividing the peak intensity originating from polymer block (a), polymer block (b), and polymer block (c), described later, by the sum of these values ​​and multiplying by 100.

[0026] The weight-average molecular weight (Mw) of polymer block (b) is preferably 5,000 or more, more preferably 10,000 or more, even more preferably 50,000 or more, and even more preferably 75,000 or more, from the viewpoint of mechanical strength, and preferably 1,500,000 or less, more preferably 500,000 or less, and even more preferably 350,000 or less, from the viewpoint of processability. The weight-average molecular weight (Mw) of polymer block (a) is preferably 5,000 to 1,500,000, more preferably 10,000 to 500,000, even more preferably 50,000 to 350,000, and 75,000 to 180,000. If the block copolymer has two or more polymer blocks (b), the weight-average molecular weight (Mw) of the polymer blocks (b) is the sum of the weight-average molecular weights of each polymer block (b).

[0027] The weight-average molecular weight (Mw) of polymer block (b) can be determined by measuring a sampled solution each time polymerization of each polymer block is completed during the manufacturing process. For example, when synthesizing a triblock copolymer having an a1-b-a2 structure by sequentially polymerizing a1, b, and a2 in that order, the weight-average molecular weight (Mw) of polymer block (b) can be determined by measuring the sampled solution at the end of polymerization of polymer block (b) using GPC to determine the weight-average molecular weight (Mw) of the diblock copolymer with the a1-b structure, and then subtracting the weight-average molecular weight (Mw) of polymer block a1 from that value.

[0028] The amount of vinyl bonding in polymer block (b) is preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 20 mol% or more, even more preferably 30 mol% or more, even more preferably 40 mol% or more, even more preferably 50 mol% or more, and even more preferably 60 mol% or more, from the viewpoint of vibration damping and reactivity, and preferably 95 mol% or less, more preferably 90 mol% or less, even more preferably 85 mol% or less, even more preferably 80 mol% or less, and even more preferably 75 mol% or less. The amount of vinyl bonding in polymer block (b) is preferably 5 to 95 mol%, more preferably 10 to 90 mol%, even more preferably 20 to 85 mol%, even more preferably 30 to 80 mol%, even more preferably 40 to 80 mol%, even more preferably 50 to 80 mol%, even more preferably 60 to 80 mol%, and even more preferably 60 to 75 mol%. When the conjugated diene compound is anything other than farnesene, the amount of vinyl bonds in polymer block (b) refers to the total mole percent of structural units derived from the conjugated diene compound that are bonded by 1,2- and 3,4- bonds, relative to 100 mol% of the total structural units constituting polymer block (b). Also, when the conjugated diene compound is anything other than farnesene, the amount of vinyl bonds in polymer block (b) refers to the total mole percent of structural units derived from the conjugated diene compound that are bonded by means other than 1,4- bonds, relative to 100 mol% of the total structural units constituting polymer block (b). When the conjugated diene compound is farnesene, the amount of vinyl bonds in polymer block (b) refers to the total mole percent of structural units derived from farnesene that are bonded by 3,13- bonds, relative to 100 mol% of the total structural units constituting polymer block (b). Furthermore, when the conjugated diene compound is farnesene, the amount of vinyl bonds in polymer block (b) represents the total mole percent of farnesene-derived structural units that are bonded by means other than 1,13-bonds, relative to 100 mole percent of the total structural units constituting polymer block (b).In other words, in this specification, "vinyl bond" means a 1,2-bond derived from butadiene when the conjugated diene compound is butadiene, a 1,2-bond and a 3,4-bond derived from isoprene when the conjugated diene compound is isoprene, and a 3,13-bond when the conjugated diene compound is farnesene. Furthermore, "amount of vinyl bonds in polymer block (b)" means the content (mol%) of structural units derived from the conjugated diene compound derived from the vinyl bond in 100 mol% of the total amount of monomer units constituting polymer block (b). In this specification, the amount of vinyl bonds in polymer block (b) is the value measured by the method described in the examples.

[0029] A block copolymer only needs to have at least one polymer block (b). If a block copolymer has two or more polymer blocks (b), these polymer blocks (b) may be the same or different. When multiple polymer blocks (b) contained in a block copolymer are different, if a polymer block (b) has one type of structural unit, it means that at least one of the weight-average molecular weight (Mw) and stereoregularity of the structural unit constituting the polymer block (b) is different. If a polymer block (b) has multiple types of structural units, it means that at least one of the ratio of each structural unit and the copolymerization form (random, tapered, block) is different. From the viewpoint of processability, it is preferable that a block copolymer has one polymer block (b).

[0030] The total content of polymer blocks (a) and (b) in the block copolymer is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, and may be 100% by mass. The total content of polymer blocks (a) and (b) in the block copolymer is preferably 50 to 100% by mass, more preferably 60 to 100% by mass, even more preferably 70 to 100% by mass, even more preferably 80 to 100% by mass, and even more preferably 90 to 100% by mass.

[0031] (polymer block (c)) The block copolymer may contain polymer block (c) composed of other monomers in addition to polymer block (a) and polymer block (b), or it may not contain polymer block (c) composed of other monomers, as long as it does not hinder the effects of the present invention. Other monomers include, for example, unsaturated hydrocarbon compounds such as propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, and 1-eicosene; and functional group-containing unsaturated compounds such as acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, acrylonitrile, methacrylonitrile, maleic acid, fumaric acid, crotonic acid, itaconic acid, 2-acryloylethanesulfonic acid, 2-methacryloylethanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-methacrylamido-2-methylpropanesulfonic acid, vinylsulfonic acid, vinyl acetate, and methyl vinyl ether. These may be used individually or in combination of two or more. The content of polymer blocks (c) in the block copolymer is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, even more preferably 20% by mass or less, even more preferably 10% by mass or less, and may be 0% by mass. The content of polymer blocks (c) in the block copolymer is preferably 0 to 50% by mass, more preferably 0 to 40% by mass, even more preferably 0 to 30% by mass, even more preferably 0 to 20% by mass, and even more preferably 0 to 10% by mass. The content of polymer blocks (c) in the block copolymer is １ In the 1H-NMR spectrum, the peak intensity originating from polymer block (c) is calculated by dividing the peak intensity originating from polymer block (a), polymer block (b), and polymer block (c) by the sum of the peak intensities originating from polymer block (a), polymer block (b), and polymer block (c), and then multiplying the result by 100.

[0032] (Mass ratio of polymer block (a) to polymer block (b)) The mass ratio of polymer block (a) to polymer block (b) in the block copolymer [(a) / (b)] is preferably 1 / 99 to 50 / 50. When the content of polymer block (a) is above the lower limit, it is easier to obtain a block copolymer with excellent mechanical strength. On the other hand, when the content of polymer block (a) is below the upper limit, it is easy to obtain a block copolymer with excellent processability. From these viewpoints, the mass ratio of polymer block (a) to polymer block (b) [(a) / (b)] is preferably 5 / 95 to 40 / 60, more preferably 8 / 92 to 30 / 70, and even more preferably 10 / 90 to 30 / 70.

[0033] (Bonding configuration of polymer block (a) and polymer block (b)) The bonding configuration of polymer block (a) and polymer block (b) contained in the block copolymer is not particularly limited and may be linear, branched, radial, or a combination of two or more thereof. Among these, a configuration in which each block is bonded linearly is preferred, and when polymer block (a) is represented as a and polymer block (b) as b, (a-b) ｌ a-(b-a) ｍ or b - (a - b) ｎ A bonding configuration represented by [b-a-b-a] or [a-b-a-b] is preferred. Hereinafter, l, m, and n each independently represent an integer of 1 or more. From the viewpoint of mechanical strength and processability, at least one of triblock copolymers, tetrablock copolymers, and pentablock copolymers is preferred as the bonding configuration. Hereinafter, a triblock copolymer is a block copolymer in which three polymer blocks are linked, a tetrablock copolymer is a block copolymer in which four polymer blocks are linked, and a pentablock copolymer is a block copolymer in which five different polymer blocks are linked. Specifically, a tetrablock copolymer represented by [b-a-b-a] or [a-b-a-b], or a triblock copolymer represented by [a-b-a] or [b-a-b] is preferred, and a triblock copolymer represented by [a-b-a] is more preferred.

[0034] (Method for producing block copolymers) Block copolymers can be produced by solution polymerization or by methods described in Japanese Patent Publication No. 2012-502135 and Japanese Patent Publication No. 2012-502136. Solution polymerization is preferred, and known methods such as ionic polymerization such as anionic polymerization and cationic polymerization, and radical polymerization can be applied. Anionic polymerization is preferred. In the anionic polymerization method, aromatic vinyl compounds, conjugated diene compounds, etc., are sequentially added in the presence of a solvent, an anionic polymerization initiator, and optionally a Lewis base to obtain a block copolymer. Examples of anionic polymerization initiators include compounds containing alkali metals such as lithium, sodium, and potassium; alkaline earth metals such as beryllium, magnesium, calcium, strontium, and barium; and lanthanide rare earth metals such as lanthanum and neodymium. Alkali metals and compounds containing alkali metals are preferred, and organic alkali metal compounds are more preferred.

[0035] Examples of the aforementioned organoalkali metal compounds include organolithium compounds such as methyllithium, ethyllithium, n-butyllithium, sec-butyllithium, t-butyllithium, hexyllithium, phenyllithium, stilbenithium, dilithithiomethane, dilithionaphthalene, 1,4-dilithiobutane, 1,4-dilithio-2-ethylcyclohexane, and 1,3,5-trilithiobenzene; sodium naphthalene, potassium naphthalene, etc. Among these, organolithium compounds are preferred, with n-butyllithium and sec-butyllithium being more preferred, and sec-butyllithium being even more preferred. The organoalkali metal compounds may also be reacted with secondary amines such as diisopropylamine, dibutylamine, dihexylamine, and dibenzylamine to be used as organoalkali metal amides. The amount of organoalkali metal compound used in polymerization varies depending on the molecular weight of the block copolymer, but is usually in the range of 0.01 to 3% by mass relative to the total amount of aromatic vinyl compounds and conjugated diene compounds.

[0036] There are no particular restrictions on the solvent as long as it does not adversely affect the anionic polymerization reaction. Examples include saturated aliphatic hydrocarbons such as n-pentane, isopentane, n-hexane, n-heptane, and isooctane; saturated alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane; and aromatic hydrocarbons such as benzene, toluene, and xylene. These may be used individually or in combination of two or more. There are no particular restrictions on the amount of solvent used.

[0037] Lewis bases play a role in controlling the microstructure of structural units derived from conjugated diene compounds. Examples of Lewis bases include ether compounds such as dibutyl ether, diethyl ether, tetrahydrofuran, dioxane, ethylene glycol diethyl ether, and ditetrahydrofurylpropane; pyridine; tertiary amines such as N,N,N',N'-tetramethylethylenediamine and trimethylamine; alkali metal alkoxides such as potassium t-butoxide; and phosphine compounds. When using Lewis bases, the amount is usually preferably in the range of 0.01 to 1000 molar equivalents per mole of anionic polymerization initiator.

[0038] The polymerization reaction temperature is typically -80 to 150°C, preferably 0 to 100°C, and more preferably 10 to 90°C. The polymerization reaction can be carried out in batches or continuously. Block copolymers can be produced by continuously or intermittently supplying each monomer to the polymerization reaction solution so that the amounts of aromatic vinyl compounds and conjugated diene compounds in the polymerization reaction system are within a specific range, or by sequentially polymerizing each monomer in the polymerization reaction solution so that they are in a specific ratio. The polymerization reaction can be stopped by adding an alcohol such as methanol or isopropanol as a polymerization stopper. The block copolymer can be isolated by pouring the obtained polymerization reaction solution into a poor solvent such as methanol to precipitate the block copolymer, or by washing the polymerization reaction solution with water, separating it, and then drying it.

[0039] In this polymerization step, an unmodified block copolymer may be obtained as described above, or a modified block copolymer may be obtained by introducing functional groups into the block copolymer. Examples of functional groups that can be introduced include amino groups, alkoxysilyl groups, hydroxyl groups, epoxy groups, carboxyl groups, carbonyl groups, mercapto groups, isocyanate groups, chloro groups, acid anhydrides, etc. Methods for modifying the block copolymer include, for example, adding a modifying agent that can react with the polymerization active end, such as tin tetrachloride, tetrachlorosilane, dichlorodimethylsilane, dimethyldiethoxysilane, tetramethoxysilane, tetraethoxysilane, 3-aminopropyltriethoxysilane, tetraglycidyl-1,3-bisaminomethylcyclohexane, 2,4-tolidyleneisocyanate, 4,4'-bis(diethylamino)benzophenone, N-vinylpyrrolidone, or other modifying agents described in Japanese Patent Application Publication No. 2011-132298, before adding a polymerization inhibitor. Furthermore, the copolymer after isolation can be grafted with maleic anhydride or the like. The functional group may be introduced at the polymerization end of the block copolymer or at the side chain. The functional group may be used alone or in combination of two or more types. The modifier is usually preferably in the range of 0.01 to 10 molar equivalents relative to the anionic polymerization initiator.

[0040] <Anti-aging agent (I)> The anti-aging agent (I) in this embodiment is a compound represented by the following general formula (1).

[0041]

[0042] In formula (1), R １ , R ２ , and R ４ One of the selected R groups is a methyl group, and R is not a methyl group. １ ~R ４ One of the selected groups is an organic group, and the methyl group and R which is not an organic group １ ~R ４ The two atoms selected are hydrogen atoms. Because the antioxidant (I) has a hydroxyl group, it captures reactive oxygen species that cause deterioration of the block copolymer over time, thereby suppressing deterioration of the block copolymer over time and improving the storage stability of the composition.

[0043] From the viewpoint of efficiently capturing reactive oxygen species to further suppress the deterioration of block copolymers over time and to create a composition with superior storage stability, R １ It is preferable that R is a methyl group. Furthermore, from the viewpoint of further suppressing the deterioration of the block copolymer over time and obtaining a composition with better storage stability, ３ It is preferable that the group is an organic group. Furthermore, from the viewpoint of further suppressing the deterioration of the block copolymer over time and obtaining a composition with better storage stability, R ２ and R ４ Preferably, is a hydrogen atom. Anti-aging agent (I) is R in general formula (1). １ is a methyl group, R ３ is an organic group, R ２ and R ４ It is more preferable that the compound is a hydrogen atom.

[0044] From the viewpoint of further suppressing the deterioration of the block copolymer over time and providing a composition with superior storage stability, the aforementioned organic group preferably contains a hydroxyphenyl group, and more preferably, in the hydroxyphenyl group, one of the two ortho positions of the hydroxyl group bonded to the benzene ring is substituted with a t-butyl group.

[0045] Examples of the anti-aging agent (I) include 3,9-bis{2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propynyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane, 4,4',4''-(1-methylpropanyl-3-ylidene)tris(6-t-butyl-m-cresol), and ethylenebis(oxyethylene)bis-(3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate). Among these, 3,9-bis{2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propynyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane is preferred. Examples of preferred commercially available products include Adeka Stab AO-80 (manufactured by ADEKA Corporation), Irganox 245 (manufactured by BASF Japan Ltd.), and Sumirizer GA-80 (manufactured by Sumitomo Chemical Co., Ltd.).

[0046] <Anti-aging agent (II)> Anti-aging agent (II) in this embodiment is a compound containing a sulfur atom, excluding anti-aging agent (I). From the viewpoint of further suppressing the deterioration of the block copolymer over time and providing a composition with better storage stability, anti-aging agent (II) is preferably a compound containing at least one selected from a thioether bond (-S-), a thioester bond (-S-C(=O)-), a sulfinyl group (-S(=O)-), and a thiol group (-SH), and more preferably at least one selected from a compound containing a thioether bond (-S-) and a hindered phenol group, and a compound containing a thioether bond (-S-) and an ester bond (-C(=O)-O-). For example, anti-aging agent (II) is more preferably at least one selected from mercaptoimidazole-based anti-aging agents, dithiocarbamate-based anti-aging agents, organic thioacid-based anti-aging agents, and thioether-based anti-aging agents.

[0047] The aforementioned hindered phenol group refers to a group in which at least one of the two ortho positions of a hydroxyl group bonded to a benzene ring is substituted with a bulky substituent. Examples of bulky substituents include the t-butyl group. Examples of the aforementioned hindered phenol group include a hydroxyphenyl group in which at least one of the two ortho positions of a hydroxyl group bonded to a benzene ring is substituted with a group containing two or more carbon atoms (excluding hydroxyphenyl groups in which one ortho position is substituted with a t-butyl group and the other ortho position and one of the two meta positions are substituted with a methyl group).

[0048] Examples of anti-aging agents (II) include 2-mercaptobenzimidazole, zinc salt of 2-mercaptobenzimidazole, nickel dibutyldithiocarbamate, 4,6-bis(dodecylthiomethyl)-o-cresol, 4,6-bis(octylthiomethyl)-o-cresol, didodecyl 3,3'-thiodipropionate, and pentaerythritol tetra(3-dodecylthiopropionate). Among these, compounds containing a thioether bond and a hindered phenol group, such as 4,6-bis(dodecylthiomethyl)-o-cresol and 4,6-bis(octylthiomethyl)-o-cresol, and compounds containing a thioether bond (-S-) and an ester bond (-C(=O)-O-), such as didodecyl 3,3'-thiodipropionate and pentaerythritol tetra(3-dodecylthiopropionate), are preferred, with pentaerythritol tetra(3-dodecylthiopropionate) being more preferred. Examples of preferred commercially available products include Nocrack MB, Nocrack MBZ, Nocrack NBC-P, Nocrack 400 (manufactured by Ouchi Shinko Chemical Industry Co., Ltd.), Sandant NBC (manufactured by Sanshin Chemical Industry Co., Ltd.), Irganox 1520 (manufactured by BASF Japan Ltd.), and Sumirizer TP-D (manufactured by Sumitomo Chemical Co., Ltd.).

[0049] <Anti-aging agent (III)> Anti-aging agent (III) in this embodiment is a compound comprising at least one selected from an acryloyl group and a methacryloyl group, and a hydroxyphenyl group. However, this excludes anti-aging agent (I) and anti-aging agent (II). Anti-aging agent (III) functions as a polymer alkyl radical scavenger. A polymer alkyl radical scavenger is a compound that captures alkyl radicals generated from polymer components. The alkyl radical may be an alkyl radical generated when the main chain or side chains of polymer components such as block copolymers are cleaved by heat, light, etc.

[0050] From the viewpoint of more effectively capturing alkyl radicals and further suppressing the deterioration of block copolymers over time, it is preferable that in the hydroxyphenyl group contained in the antioxidant (III), at least one of the two ortho positions of the hydroxyl group bonded to the benzene ring is substituted with an organic group having 2 or more carbon atoms (however, excluding hydroxyphenyl groups in which one ortho position is substituted with a t-butyl group and the other one ortho position and one of the two meta positions are substituted with a methyl group).

[0051] Examples of the anti-aging agent (III) include 2-(1-(2-hydroxy3,5-di-t-pentylphenyl)ethyl)-4,6-di-t-pentylphenyl acrylate and 2-t-butyl-4-methyl-6-(2-hydroxy-3-t-butyl-5-methylbenzyl)phenyl acrylate. Among these, 2-t-butyl-4-methyl-6-(2-hydroxy-3-t-butyl-5-methylbenzyl)phenyl acrylate is preferred. Examples of preferred commercially available products include Sumirizer GS and Sumirizer GM (manufactured by Sumitomo Chemical Co., Ltd.).

[0052] <Content of each component in the composition> In this embodiment, the composition contains 0.01 to 1.00 parts by mass of antioxidant (I) per 100 parts by mass of the block copolymer, 0.05 to 1.00 parts by mass of antioxidant (II) per 100 parts by mass of the block copolymer, and 0.05 to 1.00 parts by mass of antioxidant (III) per 100 parts by mass of the block copolymer. By having the contents of antioxidant (I), antioxidant (II), and antioxidant (III) within the above ranges, the deterioration of the block copolymer over time is suppressed, and the composition has excellent storage stability. Furthermore, it is preferable, from a balance between storage stability and suppression of bleed-out, that the content of antioxidant (I) is 0.05 to 0.50 parts by mass per 100 parts by mass of the block copolymer, the content of antioxidant (II) is 0.10 to 0.50 parts by mass per 100 parts by mass of the block copolymer, and the content of antioxidant (III) is 0.10 to 0.50 parts by mass per 100 parts by mass of the block copolymer. The content of the block copolymer in the composition is preferably 97.1 to 99.9 parts by mass, more preferably 98.0 to 99.9 parts by mass, and even more preferably 99.0 to 99.9 parts by mass.

[0053] From the viewpoint of further suppressing the deterioration of the block copolymer over time and obtaining a composition with superior storage stability, the content of the antioxidant (I) in the composition is preferably 0.03 parts by mass or more, more preferably 0.04 parts by mass or more, and even more preferably 0.05 parts by mass or more, per 100 parts by mass of the block copolymer, and from the viewpoint of suppressing the bleed-out of the antioxidant (I), it is preferably 0.80 parts by mass or less, more preferably 0.60 parts by mass or less, and even more preferably 0.50 parts by mass or less. In other words, the content of the antioxidant (I) in the composition is preferably 0.03 to 0.80 parts by mass, more preferably 0.04 to 0.60 parts by mass, and even more preferably 0.05 to 0.50 parts by mass, per 100 parts by mass of the block copolymer.

[0054] The content of the antioxidant (I) in the composition is preferably 0.03% by mass or more, more preferably 0.04% by mass or more, and even more preferably 0.05% by mass or more, from the viewpoint of further suppressing the deterioration of the block copolymer over time and obtaining a composition with better storage stability, and preferably 0.80% by mass or less, more preferably 0.60% by mass or less, and even more preferably 0.50% by mass or less, from the viewpoint of suppressing the bleed-out of the antioxidant (I). In other words, the content of the antioxidant (I) in the composition is preferably 0.03 to 0.80% by mass, more preferably 0.04 to 0.60% by mass, and even more preferably 0.05 to 0.50% by mass.

[0055] From the viewpoint of further suppressing the deterioration of the block copolymer over time and obtaining a composition with superior storage stability, the content of the antioxidant (II) in the composition is preferably 0.07 parts by mass or more, more preferably 0.09 parts by mass or more, and even more preferably 0.10 parts by mass or more, per 100 parts by mass of the block copolymer. From the viewpoint of suppressing the bleed-out of the antioxidant (II), it is preferably 0.80 parts by mass or less, more preferably 0.60 parts by mass or less, and even more preferably 0.50 parts by mass or less. In other words, the content of the antioxidant (II) in the composition is preferably 0.03 to 0.80 parts by mass, more preferably 0.04 to 0.60 parts by mass, and even more preferably 0.05 to 0.50 parts by mass, per 100 parts by mass of the block copolymer.

[0056] The content of the antioxidant (II) in the composition is preferably 0.07% by mass or more, more preferably 0.09% by mass or more, and even more preferably 0.10% by mass or more, from the viewpoint of further suppressing the deterioration of the block copolymer over time and obtaining a composition with better storage stability, and preferably 0.80% by mass or less, more preferably 0.60% by mass or less, and even more preferably 0.50% by mass or less, from the viewpoint of suppressing the bleed-out of the antioxidant (II). That is, the content of the antioxidant (II) in the composition is preferably 0.03 to 0.80% by mass, more preferably 0.04 to 0.60% by mass, and even more preferably 0.05 to 0.50% by mass.

[0057] From the viewpoint of further suppressing the deterioration of the block copolymer over time and obtaining a composition with superior storage stability, the content of the antioxidant (III) in the composition is preferably 0.07 parts by mass or more, more preferably 0.09 parts by mass or more, and even more preferably 0.10 parts by mass or more, per 100 parts by mass of the block copolymer, and from the viewpoint of suppressing the bleed-out of the antioxidant (III), it is preferably 0.80 parts by mass or less, more preferably 0.60 parts by mass or less, and even more preferably 0.50 parts by mass or less. In other words, the content of the antioxidant (III) in the composition is preferably 0.03 to 0.80 parts by mass, more preferably 0.04 to 0.60 parts by mass, and even more preferably 0.05 to 0.50 parts by mass, per 100 parts by mass of the block copolymer.

[0058] The content of the antioxidant (III) in the composition is preferably 0.07% by mass or more, more preferably 0.09% by mass or more, and even more preferably 0.10% by mass or more, from the viewpoint of further suppressing the deterioration of the block copolymer over time and obtaining a composition with better storage stability, and preferably 0.80% by mass or less, more preferably 0.60% by mass or less, and even more preferably 0.50% by mass or less, from the viewpoint of suppressing the bleed-out of the antioxidant (III). That is, the content of the antioxidant (III) in the composition is preferably 0.03 to 0.80% by mass, more preferably 0.04 to 0.60% by mass, and even more preferably 0.05 to 0.50% by mass.

[0059] The total content of antioxidant (I), antioxidant (II), and antioxidant (III) in the composition is 0.11 to 3.00 parts by mass per 100 parts by mass of block copolymer. From the viewpoint of further suppressing the deterioration of the block copolymer over time and providing a composition with superior storage stability, the total content of antioxidant (I), antioxidant (II), and antioxidant (III) in the composition is preferably 0.12 parts by mass or more, more preferably 0.13 parts by mass or more, and even more preferably 0.14 parts by mass or more, per 100 parts by mass of block copolymer. From the viewpoint of suppressing the bleed-out of antioxidant (I), antioxidant (II), and antioxidant (III), it is preferably 2.50 parts by mass or less, more preferably 2.20 parts by mass or less, and even more preferably 2.00 parts by mass or less. In other words, the total content of antioxidant (I), antioxidant (II), and antioxidant (III) in the composition is preferably 0.12 to 2.50 parts by mass, more preferably 0.13 to 2.20 parts by mass, and even more preferably 0.14 to 2.00 parts by mass, per 100 parts by mass of block copolymer.

[0060] The total content of antioxidant (I), antioxidant (II), and antioxidant (III) in the composition is preferably 0.12% by mass or more, more preferably 0.13% by mass or more, and even more preferably 0.14% by mass or more, from the viewpoint of further suppressing deterioration of the block copolymer over time and obtaining a composition with superior storage stability, and preferably 2.50% by mass or less, more preferably 2.20% by mass or less, and even more preferably 2.00% by mass or less, from the viewpoint of suppressing bleed-out of antioxidant (I), antioxidant (II), and antioxidant (III). In other words, the total content of antioxidant (I), antioxidant (II), and antioxidant (III) in the composition is preferably 0.12 to 2.50% by mass, more preferably 0.13 to 2.20% by mass, and even more preferably 0.14 to 2.00% by mass.

[0061] <Other Components> The composition of this embodiment may or may not contain other components besides the block copolymer, antioxidant (I), antioxidant (II), and antioxidant (III). Examples of other components include polymers other than the block copolymer, blocking inhibitors, antioxidants, light stabilizers, processing aids, colorants such as pigments and dyes, antistatic agents, ultraviolet absorbers, antibacterial agents, antifungal agents, fragrances, etc. These other components may be used individually or in combination of two or more.

[0062] Examples of the blocking inhibitor include inorganic particles and organic particles. Examples of the inorganic particles include oxides, hydroxides, sulfides, nitrogen compounds, halides, carbonates, sulfates, acetates, phosphates, phosphites, organic carboxylates, silicates, titanates, borates and their hydrated compounds, as well as composite compounds centered thereon and natural mineral particles. More specifically, examples include silica, calcium carbide, amorphous aluminosilicate, zeolite, diatomaceous earth, talc, feldspar, mica, gypsum, titania, zirconia, alumina, and kaolin. Examples of the above-mentioned organic particles include higher fatty acid metal salts, higher fatty acid amides, polystyrene, acrylic resins, methacrylic resins, silicone resins, fluororesins, melamine resins, styrene-divinylbenzene copolymers, acrylic silicone resins and their crosslinked products, polyolefin resins, polytetrafluoroethylene resins, and resins incompatible with resin components contained in hydrogenated compositions. Examples of the above-mentioned higher fatty acid metal salts include calcium stearate, magnesium stearate, and zinc stearate. Examples of the above-mentioned higher fatty acid amides include saturated aliphatic amides such as stearamide, unsaturated fatty acid amides such as oleamide, and bis-fatty acid amides. Examples of polyolefin resins include low molecular weight polyethylene and low molecular weight polypropylene. These anti-blocking agents can be used individually or in combination of two or more.

[0063] The shape of the blocking inhibitor is not limited as long as the effects of the present invention are not impaired, and spherical, plate-shaped, columnar, amorphous, etc., can all be used. The average particle size of the blocking inhibitor is preferably 0.1 to 20 μm, more preferably 0.5 to 15 μm, and even more preferably 0.8 to 10 μm. The average particle size of the blocking inhibitor can be measured, for example, using a laser diffraction particle size distribution analyzer. Commercially available products can also be used as blocking inhibitors. When using a commercially available blocking inhibitor, the average particle size can be determined by referring to the catalog value.

[0064] If the composition of this embodiment contains other components besides the block copolymer, antioxidant (I), antioxidant (II), and antioxidant (III), the content of the other components in the composition is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less.

[0065] [Method for producing the composition] The method for producing the composition is not limited as long as the effects of the present invention are achieved. For example, it can be obtained by mixing a block copolymer, an antioxidant (I), an antioxidant (II), and an antioxidant (III).

[0066] [Uses of the Composition] The composition of this embodiment can be used for a variety of purposes. The composition can be used, for example, for home appliances, electronic components, building materials, automobile parts, sporting goods, medical products, shoes, adhesives, coatings, and sealants, and is preferably used for these purposes. When the composition is used for the above purposes, it may further contain plasticizers, flame retardants, polyolefin resins, polyester resins, styrene resins (excluding the block copolymer of this embodiment), polyphenylene ether resins, polycarbonate resins, polyamide resins, polyurethane resins, acrylic resins, polyoxymethylene resins, vinyl chloride resins, etc. The polyolefin resin is not particularly limited as long as it is a resin polymerized with olefin as a monomer. However, the olefin is excluded from aromatic vinyl compounds. The polyolefin resin may be a homopolymer of α-olefin, a copolymer of two or more α-olefins, or a copolymer of α-olefin and a monomer other than α-olefin. Modified versions of these polymers may also be used. Specific examples of polyolefin resins include polyethylene, polypropylene, polybutene-1, polyhexene-1, poly-3-methyl-butene-1, poly-4-methyl-pentene-1, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, and olefin-based dynamically crosslinked thermoplastic elastomers (TPVs). The polyester resin is not particularly limited as long as it is a resin obtained by condensation polymerization of a polycarboxylic acid and a polyol. Specific examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate.

[0067] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these.

[0068] [Synthesis of Block Copolymers] The physical properties of the block copolymers and compositions obtained in the production examples were measured by the following method.

[0069] <Weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn)> The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the block copolymer, calculated in polystyrene terms, were determined by gel permeation chromatography (GPC) measurement under the following conditions, and the molecular weight distribution (Mw / Mn) was calculated from these values. (GPC measurement device and measurement conditions) ・Device: GPC device "HLC-8020" (manufactured by Tosoh Corporation) ・Separation column: Two "TSKgel superHZ4000" columns manufactured by Tosoh Corporation were connected in series. ・Eluent: Tetrahydrofuran ・Eluent flow rate: 0.35 mL / min ・Sample concentration: 5 mg / 10 mL ・Column temperature: 40°C ・Detector: Differential refractive index (RI) detector ・Calibration curve: Created using standard polystyrene

[0070] <Vinyl Bonding Amount> The block copolymer was dissolved in deuterated chloroform solvent and measured at a temperature of 30°C using Bruker Japan Co., Ltd.'s "AVANCE 400 Nano bay". 1 ¹H-NMR was measured. When polymer block (b) contained isoprene, the amount of vinyl bonds in polymer block (b) (total content of 3,4-bonding units and 1,2-bonding units) was calculated from the total peak area of ​​structural units derived from isoprene and the ratio of 3,4-bonding units to 1,2-bonding units in structural units derived from isoprene. When polymer block (b) did not contain isoprene, the amount of vinyl bonds in polymer block (b) was calculated from the total peak area of ​​structural units not derived from isoprene.

[0071] <Production Example 1: Production of Block Copolymer X-1> In a nitrogen-purged and dried pressure vessel, 50 kg of cyclohexane was charged as the solvent, and 0.101 kg of a cyclohexane solution of sec-butyllithium at a concentration of 10.5% by mass (actual amount of sec-butyllithium added: 10.6 g) was charged as an anionic polymerization initiator. After raising the temperature inside the pressure vessel to 50°C, 1.7 kg of styrene (1) was added and polymerization was carried out for 1 hour. After lowering the temperature inside the vessel to 40°C, 65 g of N,N,N',N'-tetramethylethylenediamine (TMEDA) was added as a Lewis base, 13.3 kg of isoprene was added over 5 hours and polymerization was carried out for 2 hours, and then 1.7 kg of styrene (2) was added and polymerization was carried out for 1 hour. Finally, 200 ml of methanol was added to stop the reaction, and a reaction solution containing block copolymer X-1, which is a polystyrene-polyisoprene-polystyrene triblock copolymer, was obtained. The above physical properties of the obtained block copolymer X-1 were measured. The results are shown in Table 1.

[0072] <Production Example 2: Production of Block Copolymer X-2> In the same manner as in Production Example 1, except that tetrahydrofuran was used instead of TMEDA as the Lewis base, a reaction solution containing block copolymer X-2, which is a polystyrene-polyisoprene-polystyrene triblock copolymer, was obtained. The above physical properties of the obtained block copolymer X-2 were measured. The results are shown in Table 1.

[0073]

[0074] [Production Preparation] The following were used to prepare the composition: • Anti-aging agent (I): "ADEKA STAB AO-80" (manufactured by ADEKA Corporation, 3,9-bis{2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propynyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane) • Anti-aging agent (II): "SUMILIZER TP-D" (manufactured by Sumitomo Chemical Co., Ltd., pentaerythritol tetra(3-dodecylthiopropionate)) • Anti-aging agent (III): "SUMILIZER GM" (manufactured by Sumitomo Chemical Co., Ltd., 2-t-butyl-4-methyl-6-(2-hydroxy-3-t-butyl-5-methylbenzyl)phenyl acrylate) • Anti-aging agent (I'): "ADEKA STAB AO-60 (manufactured by ADEKA Corporation, pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate])

[0075] <Example 1> 40 g of the reaction solution obtained in Production Example 1 was weighed out, and antioxidant (I), antioxidant (II), and antioxidant (III) were added to the reaction solution in the amounts shown in Table 2, and mixed to obtain a mixed solution. Subsequently, the mixed solution was washed with water to remove the catalysts (sec-butyllithium and TMEDA). The mixed solution after washing was poured into a mold and vacuum dried to obtain a sheet-like composition measuring 10 cm in length, 10 cm in width, and 1 mm in thickness.

[0076] <Examples 2-6> Sheet compositions were obtained in the same manner as in Example 1, except that the amounts of antioxidant (I), antioxidant (II), and antioxidant (III) added were as shown in Tables 2 and 3.

[0077] <Example 7> A sheet-like composition was obtained in the same manner as in Example 1, except that block copolymer X-2 was used instead of block copolymer X-1, and the amounts of antioxidant (I), antioxidant (II), and antioxidant (III) added were as shown in Table 2.

[0078] <Comparative Example 1> A sheet-like composition was obtained in the same manner as in Example 1, except that the antioxidant (I) was not added.

[0079] <Comparative Example 2> A sheet-like composition was obtained in the same manner as in Example 1, except that antioxidant (I') was used instead of antioxidant (I).

[0080] <Comparative Example 3> A sheet-like composition was obtained in the same manner as in Comparative Example 1, except that the amounts of antioxidant (II) and antioxidant (III) added were as shown in Table 2.

[0081] <Comparative Example 4> A sheet-like composition was obtained in the same manner as in Example 1, except that block copolymer X-2 was used instead of block copolymer X-1 and the antioxidant (I) was not added.

[0082] <Storage Stability Test> The sheet-like compositions obtained in the examples and comparative examples were heated in a gear oven at 140°C for 110 hours. The molecular weight distribution (Mw / Mn) of the sheet-like compositions was then calculated using the same method as in <Weight-Average Molecular Weight (Mw) and Molecular Weight Distribution (Mw / Mn)> in [Synthesis of Block Copolymers]. The calculated molecular weight distribution is shown in Table 2. A higher molecular weight distribution (Mw / Mn) value indicates greater degradation, while a lower value indicates less degradation. In other words, a higher molecular weight distribution (Mw / Mn) value indicates greater deterioration over time and poorer storage stability, while a lower value indicates suppressed deterioration over time and superior storage stability.

[0083]

[0084] In Comparative Example 1, attempts were made to measure the weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the composition obtained after the storage stability test. However, the composition was severely degraded and did not dissolve in tetrahydrofuran, making gel permeation chromatography (GPC) measurement impossible. The composition obtained in Comparative Example 1 appears to have undergone significant deterioration. In Comparative Examples 2 to 4, the difference between the molecular weight distribution after the storage stability test and the molecular weight distribution before the storage stability test was large, whereas in the composition of the present invention, the difference between the molecular weight distribution after the storage stability test and the molecular weight distribution before the storage stability test was small. The "molecular weight distribution before the storage stability test" refers to the molecular weight distribution of the sheet-like composition before the storage stability test, and refers to the molecular weight distribution of each block copolymer listed in Table 1. From these findings, it can be seen that the composition of the present invention exhibits excellent storage stability with suppressed deterioration of the block copolymer over time.

[0085] <Example 8> A sheet-like composition was obtained in the same manner as in Example 1.

[0086] <Comparative Example 5> A sheet-like composition was obtained in the same manner as in Comparative Example 1.

[0087] <Preliminary test of accelerated degradation> The sheet-like composition of Example 1 was heated using a gear oven, and samples were taken at elapsed time intervals. The MFR of the sampled sheet-like composition was measured using a melt indexer (TM20-A1A, manufactured by Tateyama Kagaku Co., Ltd.) in accordance with JIS K7210:1999, under conditions of a temperature of 190°C and a load of 2.16 kg, and the strand surface was visually observed after the test. The strand after the test was dissolved in tetrahydrofuran, and the molecular weight distribution (Mw / Mn) of the block copolymer contained in the sheet, in terms of polystyrene, was calculated using the same method as in <Weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn)> in [Synthesis of block copolymer] above. It was found that the smoothness of the strand surface was lost when Mw / Mn was 1.45 or higher. Thus, the elapsed time when Mw / Mn reached 1.45 was defined as the timing of degradation.

[0088] <Accelerated Degradation Test> A sheet-like composition was heated in a gear oven at 50°C, 70°C, or 90°C, and samples were taken at elapsed times. The sampled sheets were dissolved in tetrahydrofuran, and the number of days until the polystyrene-based molecular weight distribution (Mw / Mn) of the block copolymer contained in the sheet reached 1.45 was measured using the same method as in <Weight-Average Molecular Weight (Mw) and Molecular Weight Distribution (Mw / Mn)> in [Synthesis of Block Copolymer] above. The natural logarithm of the number of days until Mw / Mn reached 1.45 was plotted on the vertical axis, and the reciprocal of the test temperature was plotted on the horizontal axis. The slope (-Ea / R) and intercept (InA) in the Arrhenius equation (2) below were determined, and the predicted number of days until Mw / Mn reached 1.45 (predicted number of days until the smoothness of the strand surface after MFR measurement is lost) was calculated under an environment of 23°C. k: reaction rate constant (cm) ３ ・mol －１ ・s －１ ) A: Frequency factor (cm ３ ・mol －１ ・s －１ ) Ea: Activation energy (J・mol) －１ Table 3 shows the number of days it takes for the Mw / Mn to reach 1.45 when the sheet-like composition is heated at 50°C, 70°C, or 90°C, and the predicted number of days it takes for the Mw / Mn to reach 1.45 in an environment of 23°C.

[0089]

[0090] Table 3 shows that the composition of the present invention exhibits excellent storage stability, as it suppresses the deterioration of the block copolymer over time even under a 23°C environment, which is a typical storage environment.

Claims

1. A composition comprising a block copolymer, an anti-aging agent (I), an anti-aging agent (II), and an anti-aging agent (III), wherein the block copolymer comprises a polymer block (a) containing a structural unit derived from an aromatic vinyl compound and a polymer block (b) containing a structural unit derived from a conjugated diene compound, the anti-aging agent (I) is a compound represented by the following general formula (1), the anti-aging agent (II) is a compound containing a sulfur atom (excluding the anti-aging agent (I)), the anti-aging agent (III) is a compound containing at least one selected from an acryloyl group and a methacryloyl group, and a hydroxyphenyl group (excluding the anti-aging agent (I) and the anti-aging agent (II)), the content of the anti-aging agent (I) is 0.01 to 1.00 parts by mass based on 100 parts by mass of the block copolymer, the content of the anti-aging agent (II) is 0.05 to 1.00 parts by mass based on 100 parts by mass of the block copolymer, and the content of the anti-aging agent (III) is 0.05 to 1.00 parts by mass based on 100 parts by mass of the block copolymer. (In formula (1), R １ , R ２ , and R ４ one selected from is a methyl group, and R which is not the methyl group １ to R ４ one selected from is an organic group, and R which is neither the methyl group nor the organic group １ to R ４ two selected from are hydrogen atoms.) 2. The composition according to claim 1, wherein the amount of vinyl bond in the polymer block (b) is 30 to 80 mol%.

3. The composition according to claim 1 or 2, wherein the weight-average molecular weight of the block copolymer is 40,000 to 500,000.

4. The composition according to any one of claims 1 to 3, wherein the content of polymer block (a) in the block copolymer is 1 to 50% by mass.

5. The composition according to any one of claims 1 to 4, wherein the block copolymer is a triblock copolymer.

6. The composition according to any one of claims 1 to 5, wherein the conjugated diene compound is isoprene.

7. In equation (1), the R １ The composition according to any one of claims 1 to 6, wherein is a methyl group.

8. The composition according to any one of claims 1 to 7, wherein the hydrogenation rate of the block copolymer is 20 mol% or less.

9. The composition according to any one of claims 1 to 8, wherein the organic group in formula (1) comprises a hydroxyphenyl group.

10. The composition according to claim 9, wherein in the hydroxyphenyl group, one of the two ortho positions of the hydroxyl group bonded to the benzene ring is substituted with a t-butyl group.

11. The composition according to any one of claims 1 to 10, wherein the anti-aging agent (II) is a compound comprising at least one selected from a thioether bond (-S-), a thioester bond (-S-C(=O)-), a sulfinyl group (-S(=O)-), and a thiol group (-SH).

12. The composition according to any one of claims 1 to 11, wherein in the hydroxyphenyl group contained in the anti-aging agent (III), at least one of the two ortho positions of the hydroxyl group bonded to the benzene ring is substituted with an organic group having 2 or more carbon atoms.

13. The composition according to any one of claims 1 to 12, wherein the total content of the antioxidant (I), the antioxidant (II), and the antioxidant (III) is 0.11 to 3.00 parts by mass per 100 parts by mass of the block copolymer.

14. The composition according to any one of claims 1 to 13, wherein the content of the antioxidant (I) is 0.05 to 0.50 parts by mass per 100 parts by mass of the block copolymer, the content of the antioxidant (II) is 0.10 to 0.50 parts by mass per 100 parts by mass of the block copolymer, and the content of the antioxidant (III) is 0.10 to 0.50 parts by mass per 100 parts by mass of the block copolymer.

15. The composition according to any one of claims 1 to 14, which is used as at least one selected from home appliances, electronic components, building materials, automobile parts, sporting goods, medical products, shoes, adhesives, coatings, and sealing materials.

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