JP6630736B2 - Block copolymer, method for producing the same, and use thereof - Google Patents

Description

The present specification relates to a block copolymer and a method for producing the same, and more particularly, to a block copolymer useful as an elastomer having excellent heat resistance, oil resistance and moldability, and a method for producing the same.
(Cross-reference of related applications)
This application is based on Japanese Patent Application No. 2015-210708 filed on Oct. 27, 2015 and Japanese Patent Application No. 2006-108516 filed on May 31, 2016. All claims are hereby incorporated by reference in their entirety.

Various elastomers such as nitrile rubber, acrylic rubber, silicone rubber, fluororubber and ethylene tetrafluoride resin (PTFE) are widely used as seal materials in industrial use. Among them, acrylic rubber is a rubber-like elastic material mainly composed of acrylic acid ester, and has excellent heat resistance and oil resistance. Therefore, various hose materials, adhesives, coatings, including packing and sealing materials for automobiles Widely used as materials such as materials.
On the other hand, especially in automotive applications, the engine room tends to heat up due to the increase in engine output and the installation of soundproofing materials for quietness, etc., and there is a demand for improved heat resistance and oil resistance for elastomers. Is growing.

Against this background, several elastomer compositions having high heat resistance and oil resistance have been proposed. Patent Document 1 discloses a specific graft copolymer comprising an epoxy group-containing acrylic rubber (component (A)), a thermoplastic polyester resin (component (B)), and an olefin-based polymer segment and a vinyl-based copolymer segment. A thermoplastic elastomer composition comprising a polymer or a precursor thereof (component (C)), which is obtained by crosslinking the component (A), is disclosed. Patent Document 2 discloses an acrylic rubber composition obtained by mixing at least one kind of a filler and a foil-like filler with a carboxyl group-containing acrylic rubber.
However, even the compositions described in Patent Literatures 1 and 2 are not sufficiently satisfactory for uses requiring high heat resistance and oil resistance. Furthermore, there were concerns about fluidity and moldability.

As an elastomer composition having excellent fluidity and moldability, an elastomer composition containing a block copolymer is known. Patent Document 3 discloses that (A) a (meth) acrylic copolymer, (B) a transesterification catalyst, and (C) a thermoplastic resin as essential components, and the (meth) acrylic copolymer comprises (a) A thermoplastic elastomer composition comprising a methacrylic polymer block and (b) a block copolymer (E) containing an acrylic polymer block is disclosed.
Patent Document 4 discloses a block copolymer containing one or more methacrylic copolymer blocks (A) and one or more acrylic copolymer blocks (B), and a methacrylic copolymer ( A) is a random copolymer block containing a repeating unit derived from a methacrylate monomer and a repeating unit derived from two types of N-substituted maleimide monomers, and the acrylic copolymer block (B) is And an acrylic thermoplastic resin containing a repeating unit derived from an acrylate monomer.

JP 2007-45885 A JP 2011-144364 A JP 2003-261733 A JP 2014-12772 A

However, the thermoplastic elastomer composition described in Patent Literature 3 may not be sufficiently satisfied in terms of heat resistance and oil resistance depending on applications, and further improvement in performance is required. The thermoplastic resin described in Patent Document 4 exhibits good heat resistance and oil resistance, and can withstand applications under severe conditions from the viewpoint of heat and oil resistance. However, there is still room for improvement in terms of fluidity and moldability.
As described above, an elastomer composition exhibiting high heat resistance and oil resistance and having excellent moldability has not yet been described. Further, members such as O-rings and gaskets are strongly required to have a property of recovering the deformation when the force is released after the force is applied for a long period of time and then the force is released. It has been demanded.

  The technology disclosed in this specification has been made in view of such circumstances. That is, an object of the present invention is to provide an elastomer material having excellent heat resistance and oil resistance, exhibiting good fluidity, and having excellent moldability, and a method for producing the same. Yet another object of the technology disclosed herein is to provide an elastomeric material with low compression set.

  As a result of intensive studies to solve the above problems, the present inventors have found that a block copolymer having a polymer block containing a structural unit derived from styrenes and a maleimide compound as a hard segment is excellent in the above-described various performances. I got the knowledge. Also, they have found that the above block copolymer can be efficiently obtained by utilizing the living radical polymerization method. The present invention has been completed based on these findings.

〔式中、Ｒ^１は水素、炭素数１〜３のアルキル基又はＰｈＲ^２を表す。ただし、Ｐｈはフェニル基を表し、Ｒ^２は水素、ヒドロキシ基、炭素数１〜２のアルコキシ基、アセチル基又はハロゲンを表す。〕
〔５〕前記重合体ブロック（Ａ）が、さらに、アミド基含有ビニル化合物に由来する構造単位を有する前記〔１〕〜〔４〕のいずれか一に記載のブロック共重合体。
〔６〕前記重合体ブロック（Ａ）及びアクリル系重合体ブロック（Ｂ）の少なくともいずれかに架橋性官能基を有する前記〔１〕〜〔５〕のいずれか一に記載のブロック共重合体。
〔７〕前記架橋性官能基が架橋性単量体に由来するものであり、前記重合体ブロック（Ａ）の全構造単位に対して前記架橋性単量体に由来する構造単位を０．０１モル％以上６０モル％以下有する前記〔６〕に記載のブロック共重合体。
〔８〕数平均分子量が、１００００以上５０００００以下である前記〔１〕〜〔７〕のいずれか一に記載のブロック共重合体。
〔９〕スチレン類及びマレイミド化合物に由来する構造単位を含む重合体ブロック（Ａ）、並びに、アクリル系重合体ブロック（Ｂ）を有するブロック共重合体を、リビングラジカル重合法により製造する方法であって、
前記重合体ブロック（Ａ）は、該重合体ブロック（Ａ）の全構造単位に対してマレイミド化合物に由来する構造単位を３０質量％以上９９質量％以下有し、且つ、Ｔｇが１５０℃以上の重合体であり、
前記アクリル系重合体ブロック（Ｂ）は、溶解パラメータ（ＳＰ値）が９．９以上、且つ、Ｔｇが２０℃以下の重合体である、
方法。
〔１０〕第一重合工程として、スチレン類１質量％以上７０質量％以下、及びマレイミド化合物３０質量％以上９９質量％以下を含む単量体を重合して前記ブロック（Ａ）を得る工程、
次いで、第二重合工程として、アクリル系単量体を重合して前記重合体ブロック（Ｂ）を得る工程、
さらに第三重合工程として、スチレン類１質量％以上７０質量％以下、及びマレイミド化合物３０質量％以上９９質量％以下を含む単量体を重合して前記ブロック（Ａ）を得る工程を含む、
前記〔９〕に記載のブロック共重合体の製造方法。
〔１１〕第一重合工程として、アクリル系単量体を重合して前記ブロック（Ｂ）を得る工程、並びに、
第二重合工程として、前記スチレン類１質量％以上７０質量％以下、及び前記マレイミド化合物３０質量％以上９９質量％以下を含む単量体を重合して前記重合体ブロック（Ａ）を得る工程を含む、
前記〔９〕に記載のブロック共重合体の製造方法。
〔１２〕前記〔１〕〜〔８〕のいずれか一に記載のブロック共重合体を含むエラストマー。
〔１３〕前記〔１〕〜〔８〕のいずれか一に記載のブロック共重合体を含む自動車用エラストマー。The present invention is as follows.
[1] A block copolymer having a polymer block (A) containing a structural unit derived from a styrene and a maleimide compound, and an acrylic polymer block (B),
The polymer block (A) has a structural unit derived from a maleimide compound in an amount of 30% by mass or more and 99% by mass or less based on all structural units of the polymer block (A), and has a glass transition temperature (Tg). Is a polymer of 150 ° C. or higher,
A block copolymer, wherein the acrylic polymer block (B) is a polymer having a solubility parameter (SP value) of 9.9 or more and a Tg of 20 ° C. or less.
[2] The block copolymer according to [1], wherein the polymer block (A) has a solubility parameter (SP value) of 10.0 or more.
[3] The above-mentioned [1] or [1], wherein the polymer block (A) has a structural unit derived from the styrene in an amount of 1% by mass to 70% by mass with respect to all structural units of the polymer block (A). The block copolymer according to 2).
[4] The block copolymer according to any one of [1] to [3], wherein the maleimide compound contains at least one compound represented by the general formula (1).

[In the formula, R ¹ represents hydrogen, an alkyl group having 1 to 3 carbon atoms, or PhR ² . However, Ph represents a phenyl group, R ² represents hydrogen, hydroxy group, an alkoxy group having 1 to 2 carbon atoms, an acetyl group or a halogen. ]
[5] The block copolymer according to any one of [1] to [4], wherein the polymer block (A) further has a structural unit derived from an amide group-containing vinyl compound.
[6] The block copolymer according to any one of [1] to [5], wherein at least one of the polymer block (A) and the acrylic polymer block (B) has a crosslinkable functional group.
[7] The crosslinkable functional group is derived from a crosslinkable monomer, and the amount of the structural unit derived from the crosslinkable monomer is 0.01 to the total structural units of the polymer block (A). The block copolymer according to the above [6], which has a molar percentage of 60 mol% or more and 60 mol% or less.
[8] The block copolymer according to any one of [1] to [7], wherein the number average molecular weight is 10,000 to 500,000.
[9] A method for producing a block copolymer having a polymer block (A) containing a structural unit derived from styrenes and a maleimide compound, and a block copolymer having an acrylic polymer block (B) by a living radical polymerization method. hand,
The polymer block (A) has a structural unit derived from a maleimide compound in an amount of 30% by mass or more and 99% by mass or less based on all structural units of the polymer block (A), and has a Tg of 150 ° C or more. A polymer,
The acrylic polymer block (B) is a polymer having a solubility parameter (SP value) of 9.9 or more and a Tg of 20 ° C. or less.
Method.
[10] As a first polymerization step, a step of polymerizing a monomer containing 1% to 70% by mass of styrenes and 30% to 99% by mass of a maleimide compound to obtain the block (A),
Next, as a second polymerization step, a step of polymerizing an acrylic monomer to obtain the polymer block (B),
The third polymerization step further includes a step of polymerizing a monomer containing 1% to 70% by mass of styrenes and 30% to 99% by mass of a maleimide compound to obtain the block (A).
The method for producing a block copolymer according to the above [9].
[11] As a first polymerization step, a step of polymerizing an acrylic monomer to obtain the block (B), and
The second polymerization step includes a step of polymerizing a monomer containing 1% to 70% by mass of the styrenes and 30% to 99% by mass of the maleimide compound to obtain the polymer block (A). Including,
The method for producing a block copolymer according to the above [9].
[12] An elastomer containing the block copolymer according to any one of [1] to [8].
[13] An automotive elastomer comprising the block copolymer according to any one of [1] to [8].

According to the block copolymer disclosed in the present specification, an elastomer material exhibiting extremely high heat resistance and oil resistance can be obtained. In addition, since it has good fluidity, it is excellent in moldability and can provide a high-quality molded article. Further, an elastomer material having a small compression set can be obtained.
Furthermore, according to the production method disclosed in the present specification, the block copolymer can be obtained easily and efficiently.

  Hereinafter, typical and non-limiting specific examples of the present disclosure will be described in detail with reference to the drawings as appropriate. This detailed description is merely intended to provide those skilled in the art with details for carrying out the preferred embodiments of the present disclosure and is not intended to limit the scope of the present disclosure. Also, the additional features and disclosures disclosed below can be used separately or together with other features and disclosures to provide further improved block copolymers and methods of making the same.

  In addition, the combination of features and steps disclosed in the following detailed description is not essential in practicing the present disclosure in the broadest sense, and is particularly only for describing a typical specific example of the present disclosure. It is described. Furthermore, various features of the above and below representative embodiments, as well as those of the independent and dependent claims, are set forth in providing additional and useful embodiments of the present disclosure. It is not necessary to combine them according to the specific examples given or in the order listed.

  All features set forth in the specification and / or the claims, apart from constructions of the features set forth in the examples and / or the claims, are individually described as limitations on the disclosure as originally filed and on the particulars claimed. And are intended to be disclosed independently of one another. Further, all numerical ranges and group or group descriptions are intended to disclose the intermediary configuration as a disclosure of the application as originally filed, as well as limitations on the claimed subject matter.

  Hereinafter, various embodiments of the technology disclosed in this specification will be described in detail. In the present specification, “(meth) acryl” means acryl and methacryl, and “(meth) acrylate” means acrylate and methacrylate. Further, “(meth) acryloyl group” means an acryloyl group and a methacryloyl group.

  The block copolymer disclosed in the present specification has at least one polymer block (A) containing a structural unit derived from styrenes and a maleimide compound, and at least one acrylic polymer block (B). When the block copolymer has two or more polymer blocks (A) and / or acrylic polymer blocks (B), the structure of each block may be the same or different.

<Polymer block (A)>
As described above, the polymer block (A) has structural units derived from styrenes and a maleimide compound.
The styrenes include styrene and its derivatives. Specific compounds include styrene, α-methylstyrene, β-methylstyrene, vinyltoluene, vinylxylene, vinylnaphthalene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-ethylstyrene, and m-methylstyrene. Ethyl styrene, p-ethyl styrene, pn-butyl styrene, p-isobutyl styrene, pt-butyl styrene, o-methoxy styrene, m-methoxy styrene, p-methoxy styrene, o-chloromethyl styrene, p- Examples thereof include chloromethylstyrene, o-chlorostyrene, p-chlorostyrene, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, and divinylbenzene, and one or more of these may be used. it can. By polymerizing a monomer containing styrene, a structural unit derived from styrene can be introduced into the polymer block (A).
Among them, styrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, o-hydroxystyrene, m-hydroxystyrene, and p-hydroxystyrene are preferable from the viewpoint of polymerizability. Further, α-methylstyrene, β-methylstyrene, and vinylnaphthalene are preferable in that Tg of the polymer block (A) can be increased and a block polymer having excellent heat resistance can be obtained.

In the polymer block (A), the proportion occupied by the styrene-derived structural units is preferably 1% by mass or more and 70% by mass or less based on all the structural units of the polymer block (A). It is more preferably from 5% by mass to 70% by mass, further preferably from 10% by mass to 70% by mass, and still more preferably from 20% by mass to 60% by mass. Further, for example, it may be 20% by mass or more and 40% by mass or less.
When the structural unit derived from styrenes is 1% by mass or more, a block copolymer excellent in moldability can be obtained. On the other hand, when the content is 70% by mass or less, a required amount of a structural unit derived from a maleimide compound described later can be secured, so that a block copolymer excellent in heat resistance and oil resistance can be obtained.

〔式中、Ｒ^１は水素、炭素数１〜３のアルキル基又はＰｈＲ^２を表す。ただし、Ｐｈはフェニル基を表し、Ｒ^２は水素、ヒドロキシ基、炭素数１〜２のアルコキシ基、アセチル基又はハロゲンを表す。〕The maleimide compound includes a maleimide and an N-substituted maleimide compound. Examples of the N-substituted maleimide compound include N-methylmaleimide, N-ethylmaleimide, Nn-propylmaleimide, N-isopropylmaleimide, Nn-butylmaleimide, N-isobutylmaleimide, and N-tert-butylmaleimide. N-alkyl-substituted maleimide compounds such as N-pentylmaleimide, N-hexylmaleimide, N-heptylmaleimide, N-octylmaleimide, N-laurylmaleimide and N-stearylmaleimide; N-cyclopentylmaleimide, N-cyclohexylmaleimide and the like. N-cycloalkyl-substituted maleimide compounds; N-phenylmaleimide, N- (4-hydroxyphenyl) maleimide, N- (4-acetylphenyl) maleimide, N- (4-methoxyphenyl) maleimide, N- (4- N-aryl-substituted maleimide compounds such as toxicphenyl) maleimide, N- (4-chlorophenyl) maleimide, N- (4-bromophenyl) maleimide, N-benzylmaleimide, etc., and one or two of them. The above can be used. By polymerizing a monomer containing a maleimide compound, a structural unit derived from the maleimide compound can be introduced into the polymer block (A).
Among the above, the compounds represented by the following general formula (1) are preferable in that the obtained block copolymer has more excellent oil resistance.

[In the formula, R ¹ represents hydrogen, an alkyl group having 1 to 3 carbon atoms, or PhR ² . However, Ph represents a phenyl group, R ² represents hydrogen, hydroxy group, an alkoxy group having 1 to 2 carbon atoms, an acetyl group or a halogen. ]

In the polymer block (A), the proportion occupied by the structural units derived from the maleimide compound is 30% by mass or more and 99% by mass or less based on all the structural units of the polymer block (A). It is preferably from 30% by mass to 95% by mass, more preferably from 30% by mass to 90% by mass, further preferably from 40% by mass to 80% by mass. In addition, for example, it may be 50% by mass or more, and for example, may be 60% by mass or more. Further, for example, it may be 75% by mass or less, and further may be, for example, 70% by mass or less. Further, for example, it may be 50% by mass or more and 75% by mass or less, or may be 60% by mass or more and 70% by mass or less.
When the structural unit derived from the maleimide compound is less than 30% by mass, the resulting block copolymer may not have sufficient heat resistance and oil resistance. On the other hand, when the content exceeds 99% by mass, the structural units derived from the styrenes become insufficient, so that fluidity and moldability may become insufficient.

  The case where the polymer block (A) contains a crosslinkable functional group is preferable in that a block copolymer having a small value of compression set is easily obtained. For the introduction of the crosslinkable functional group, for example, styrenes and / or a maleimide compound having a functional group such as a hydroxy group may be used, or may be introduced by copolymerizing a vinyl compound having a crosslinkable functional group. Can be. Examples of the vinyl compound having a crosslinkable functional group include unsaturated carboxylic acids, unsaturated acid anhydrides, hydroxy group-containing vinyl compounds, epoxy group-containing vinyl compounds, primary or secondary amino group-containing vinyl compounds, and reactive silicon group-containing And the like. These compounds may be used alone or in combination of two or more.

  Examples of unsaturated carboxylic acids include (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, cinnamic acid, and monoalkyl esters of unsaturated dicarboxylic acids (maleic acid, fumaric acid, itaconic acid). Acids, citraconic acid, maleic anhydride, itaconic anhydride, monoalkyl esters such as citraconic anhydride) and the like. These compounds may be used alone or in combination of two or more.

  Examples of the unsaturated acid anhydride include maleic anhydride, itaconic anhydride, citraconic anhydride and the like. These compounds may be used alone or in combination of two or more.

  Examples of the hydroxy group-containing vinyl compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and (meth) acrylate. ) 3-hydroxybutyl acrylate, 4-hydroxybutyl (meth) acrylate, and mono (meth) acrylates of polyalkylene glycols such as polyethylene glycol and polypropylene glycol. These compounds may be used alone or in combination of two or more.

  Examples of the epoxy group-containing vinyl compound include glycidyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether, and 3,4-epoxycyclohexylmethyl (meth) acrylate. These compounds may be used alone or in combination of two or more.

  Examples of the primary or secondary amino group-containing vinyl compound include amino groups such as aminoethyl (meth) acrylate, aminopropyl (meth) acrylate, N-methylaminoethyl (meth) acrylate, and N-ethylaminoethyl (meth) acrylate. (Meth) acrylic acid ester; amino group-containing (meth) acrylamide such as aminoethyl (meth) acrylamide, aminopropyl (meth) acrylamide, N-methylaminoethyl (meth) acrylamide, N-ethylaminoethyl (meth) acrylamide And the like.

  Examples of the reactive silicon group-containing compound include vinylsilanes such as vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane, and vinyldimethylmethoxysilane; trimethoxysilylpropyl (meth) acrylate, and trimethoxy (meth) acrylate. Silyl group-containing (meth) acrylates such as ethoxysilylpropyl, methyldimethoxysilylpropyl (meth) acrylate, and dimethylmethoxysilylpropyl (meth) acrylate; silyl group-containing vinyl ethers such as trimethoxysilylpropyl vinyl ether; Examples thereof include vinyl esters containing a silyl group such as vinyl methoxysilylundecanoate. These compounds may be used alone or in combination of two or more.

  In addition to the above, an oxazoline group or an isocyanate group can be introduced as a crosslinkable functional group by copolymerizing an oxazoline group-containing monomer or an isocyanate group-containing monomer.

  Furthermore, a polymerizable unsaturated group is introduced as a crosslinkable functional group into the polymer block (A) by copolymerizing a polyfunctional polymerizable monomer having two or more polymerizable unsaturated groups in the molecule. obtain. The polyfunctional polymerizable monomer is a compound having two or more polymerizable functional groups such as a (meth) acryloyl group and an alkenyl group in a molecule, and is a polyfunctional (meth) acrylate compound, a polyfunctional alkenyl compound, A compound having both a (meth) acryloyl group and an alkenyl group is exemplified. Among these, allyl (meth) acrylate, isopropenyl (meth) acrylate, butenyl (meth) acrylate, pentenyl (meth) acrylate, 2- (2-vinyloxyethoxy) ethyl (meth) acrylate, etc. When a compound having both a (meth) acryloyl group and an alkenyl group in the molecule of is used, the polymer block (A) is effectively polymerized unsaturated due to the difference in the reactivity of the polymerizable unsaturated group. It is preferable in that a group can be introduced. These compounds may be used alone or in combination of two or more.

  When the polymer block (A) has a crosslinkable functional group, the amount of the crosslinkable functional group to be introduced is preferably 0.01 mol% or more based on all structural units of the polymer block (A). It is preferably at least 0.1 mol%, more preferably at least 1.0 mol%, particularly preferably at least 2.0 mol%. When the introduction amount of the crosslinkable functional group is 0.01 mol% or more, it becomes easy to obtain a block copolymer having a small value of compression set. On the other hand, from the viewpoint of controllability of the crosslinking reaction, the upper limit of the amount of the crosslinkable functional group to be introduced is preferably 60 mol% or less, more preferably 40 mol% or less, further more preferably 20 mol% or less. Preferably it is 10 mol% or less. The introduction amount of the crosslinkable functional group can be in the range of 0.01 mol% to 60 mol%, preferably 0.1 mol% to 40 mol%, based on the total structural units of the polymer block (A). %, More preferably from 1.0 mol% to 20 mol%.

The polymer block (A) may have a structural unit derived from another monomer copolymerizable therewith, in addition to the above-mentioned monomer units, as long as the effects of the present disclosure are not impaired. Good. Examples of other monomers include (meth) acrylic acid alkyl ester compounds, (meth) acrylic acid alkoxyalkyl ester compounds, and amide group-containing vinyl compounds. These compounds may be used alone or in combination of two or more.
Among these, an amide group-containing vinyl compound is preferable because a block copolymer having more excellent oil resistance can be obtained.
In the polymer block (A), the proportion occupied by the structural units derived from the other monomers is in the range of 0% by mass or more and 50% by mass or less based on all the structural units of the polymer block (A). Is preferred. More preferably, it is 5% by mass or more and 45% by mass or less, and further preferably 10% by mass or more and 40% by mass or less.

Specific examples of the alkyl (meth) acrylate compound include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-propyl (meth) acrylate, and n- (meth) acrylate. -Butyl, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate Linear or branched alkyl ester compounds of (meth) acrylic acid such as n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate and dodecyl (meth) acrylate;
Cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, tert-butylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, (meth) acrylate Examples thereof include aliphatic cyclic ester compounds of (meth) acrylic acid such as dicyclopentenyl acrylate and dicyclopentanyl (meth) acrylate.

  Examples of the alkoxyalkyl (meth) acrylate compound include methoxymethyl (meth) acrylate, ethoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, and n- (meth) acrylate. -Propoxyethyl, n-butoxyethyl (meth) acrylate, methoxypropyl (meth) acrylate, ethoxypropyl (meth) acrylate, n-propoxypropyl (meth) acrylate, n-butoxypropyl (meth) acrylate, Examples include methoxybutyl (meth) acrylate, ethoxybutyl (meth) acrylate, n-propoxybutyl (meth) acrylate, and n-butoxybutyl (meth) acrylate.

  Examples of the amide group-containing vinyl compound include (meth) acrylamide, tert-butyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, and N-isopropyl (meth) acrylamide. (Meth) acrylamide derivatives such as N, N, N-dimethylaminopropyl (meth) acrylamide and (meth) acryloylmorpholine; and N-vinylamide-based compounds such as N-vinylacetamide, N-vinylformamide and N-vinylisobutylamide And the like.

  Other monomers other than the above include N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, and the like.

In the present disclosure, the polymer constituting the polymer block (A) preferably has a glass transition temperature (Tg) of 150 ° C. or higher. Since Tg can contribute to heat resistance, it may be, for example, 170 ° C. or higher, 180 ° C. or higher, 190 ° C. or higher, or 200 ° C. or higher. Furthermore, it may be 210 ° C. or higher, 220 ° C. or higher, or 230 ° C. or higher. When Tg is lower than 150 ° C., the heat resistance and oil resistance of the obtained block copolymer may be insufficient. The upper limit of Tg is 350 ° C. from the limitation of usable constituent monomer units. Tg may also be, for example, 280 ° C. or lower, or 270 ° C. or lower, for example, 260 ° C. or lower.
In addition, the value of Tg can be obtained by differential scanning calorimetry (DSC) as described in Examples described later. It can also be determined by calculation from the monomer units constituting the polymer block.

When the solubility parameter (SP value) of the polymer block (A) is 10.0 or more, it is preferable in that the oil resistance of the block copolymer becomes better. The SP value is more preferably 11.0 or more, further preferably 12.0 or more, and still more preferably 13.0 or more.
The upper limit of the SP value of the polymer block (A) is not particularly limited, but is usually 30 or less. Further, for example, the SP value may be 20.0 or less, and may be, for example, 18.0 or less.

δ ：ＳＰ値（（ｃａｌ／ｃｍ^３）^１／２）
ΔＥ_ｖａｐ ：各原子団のモル蒸発熱（ｃａｌ／ｍｏｌ）
Ｖ ：各原子団のモル体積（ｃｍ^３／ｍｏｌ）Regarding the above SP value, R. F. It can be calculated by the calculation method described in “Polymer Engineering and Science” written by Fedors, 14 (2), 147 (1974). Specifically, the calculation is performed according to the calculation method shown in Expression (1).

δ: SP value ((cal / cm ³ ) ^1/2 )
ΔE _vap : molar evaporation heat of each atomic group (cal / mol)
V: molar volume of each atomic group (cm ³ / mol)

<Acrylic polymer block (B)>
The acrylic polymer block (B) can be obtained by polymerizing a monomer containing an acrylic monomer. The acrylic monomer refers to an unsaturated compound having an acryloyl group such as acrylic acid and an acrylate compound. Examples of the acrylate compound include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, hexyl acrylate, and acrylate 2- Alkyl acrylate compounds such as ethylhexyl, octyl acrylate, nonyl acrylate, decyl acrylate, lauryl acrylate, and stearyl acrylate;
Aliphatic cyclic ester compounds of acrylic acid such as cyclohexyl acrylate, methylcyclohexyl acrylate, tert-butylcyclohexyl acrylate, cyclododecyl acrylate;
Methoxymethyl acrylate, ethoxymethyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, n-propoxyethyl acrylate, n-butoxyethyl acrylate, methoxypropyl acrylate, ethoxypropyl acrylate, n-propoxypropyl acrylate And alkoxyalkyl acrylate compounds such as n-butoxypropyl acrylate, methoxybutyl acrylate, ethoxybutyl acrylate, n-propoxybutyl acrylate and n-butoxybutyl acrylate. In addition, an acrylate compound having a functional group such as an amide group, an amino group, a carboxy group, and a hydroxy group may be used.
Among them, an alkyl acrylate compound having an alkyl group having 1 to 12 carbon atoms or an alkoxyalkyl group having 2 to 8 carbon atoms is preferable in that a block copolymer having excellent flexibility is obtained. When the heat resistance and oil resistance are taken into consideration, the acrylic monomer contains an alkyl acrylate compound having an alkyl group having 1 to 3 carbon atoms or an alkoxyalkyl group having 2 to 3 carbon atoms. Is more preferable.

In the acrylic polymer block (B), the ratio occupied by the structural units derived from the acrylic monomer is in the range of 20% by mass or more and 100% by mass or less based on all the structural units of the acrylic polymer block (B). Is preferably 50% by mass or more and 100% by mass or less, more preferably 80% by mass or more and 100% by mass or less, and still more preferably 90% by mass or more and 100% by mass or less.
In the acrylic polymer block (B), when the structural unit derived from the acrylic monomer is within the above range, a block copolymer excellent in mechanical properties tends to be obtained.

  In the acrylic polymer block (B), a monomer other than the acrylic monomer can be used as a constituent monomer unit as long as the effects exerted by the present disclosure are not hindered. As the monomer other than the acrylic monomer, a monomer having an unsaturated group other than an acryloyl group can be used, and a methacryloyl group-containing compound such as methacrylic acid ester, and an alkyl vinyl ester, an alkyl vinyl ether and Examples thereof include aliphatic or aromatic vinyl compounds such as styrenes.

In the present disclosure, the Tg of the polymer constituting the acrylic polymer block (B) is preferably 20 ° C. or less. Further, for example, the temperature may be 10 ° C. or less. Tg is preferably 0 ° C or lower, more preferably -10 ° C or lower. When Tg exceeds 20 ° C., the flexibility of the obtained block copolymer may be insufficient. The lower limit of Tg is -80 ° C due to the limitation of usable constituent monomer units.
Further, when Tg is -20 ° C or lower, it is preferable because flexibility is ensured even in a low temperature environment. When cold resistance is taken into consideration, the temperature is more preferably -30 ° C or lower, and further preferably -40 ° C or lower.

Further, when the SP value of the acrylic polymer block (B) is 9.9 or more, it is preferable in that the oil resistance of the block copolymer becomes better. The SP value is more preferably 10.0 or more, further preferably 10.1 or more, and particularly preferably 10.2 or more.
The upper limit of the SP value of the acrylic polymer block (B) is not particularly limited, but is usually 20 or less.

Further, the polymer block (B) may contain a crosslinkable functional group, which is preferable in that a block copolymer having high oil resistance is easily obtained. The crosslinkable functional group can be introduced by, for example, copolymerizing a vinyl compound having a crosslinkable functional group. Examples of the vinyl compound having a crosslinkable functional group include unsaturated carboxylic acids, unsaturated acid anhydrides, hydroxy group-containing vinyl compounds, epoxy group-containing vinyl compounds, primary or secondary amino group-containing vinyl compounds, and reactive silicon group-containing And the like. These compounds may be used alone or in combination of two or more.
When the polymer block (B) has a crosslinkable functional group, the amount of the crosslinkable functional group to be introduced is preferably 0.01 mol% or more based on all structural units of the polymer block (B). It is preferably at least 0.1 mol%, more preferably at least 0.5 mol%. When the introduction amount of the crosslinkable functional group is 0.01 mol% or more, it becomes easy to obtain a block copolymer having high oil resistance. On the other hand, from the viewpoint of flexibility, the upper limit of the amount of the crosslinkable functional group introduced is preferably 20 mol% or less, more preferably 10 mol% or less, and further preferably 5 mol% or less. The introduction amount of the crosslinkable functional group can be in the range of 0.01 mol% or more and 20 mol% or less, preferably 0.1 mol% or more and 10 mol% or less based on all structural units of the polymer block (B). %, More preferably from 0.5 mol% to 5 mol%.

<Block copolymer>
The block copolymer of the present disclosure has at least one polymer block (A) and one or more acrylic polymer blocks (B). When the block copolymer has two or more polymer blocks (A) and / or acrylic polymer blocks (B), the structures of the blocks may be the same or different.
There is no particular limitation on the structure of the block copolymer, and various linear or branched block copolymers such as an AB-type diblock polymer or ABA- and ABC-type triblock polymers can be used. In terms of obtaining good performance as an elastomer material, A- (BA) such as an ABA triblock copolymer composed of a polymer block (A) -acrylic polymer block (B) -polymer block (A) Those having an n-type structure are preferred.

In the block copolymer, the polymer block (A) acts as a hard segment, and the acrylic polymer block (B) acts as a soft segment. As a result, the block copolymer of the present disclosure exhibits excellent performance in mechanical properties such as elongation at break and breaking strength, and is a material useful as an elastomer.
The proportion of the polymer block (A) in the block copolymer is preferably from 10% by mass to 60% by mass, more preferably from 20% by mass to 50% by mass.
The proportion of the acrylic polymer block (B) in the block copolymer is preferably from 40% by mass to 90% by mass, and more preferably from 50% by mass to 80% by mass.

  When the block copolymer of the present disclosure is used as an elastomer material, the SP value of the polymer block (A) and the SP value of the acrylic polymer block (B) preferably have a difference of 0.1 or more. When the SP value differs by 0.1 or more, the two are appropriately phase-separated in the block copolymer, so that it is possible to exhibit excellent performance in mechanical strength. The difference between the SP values is more preferably 0.3 or more, still more preferably 0.5 or more, further preferably 0.8 or more, and particularly preferably 1.0 or more. . In addition, from the viewpoint of manufacturing and the like, the difference in SP value is preferably 10 or less, and more preferably 5.0 or less.

  In the case where the polymer block (A) has a crosslinkable functional group, crosslinking is utilized to obtain an elastomer material having a smaller compression set value. The cross-linking may be caused by a reaction between cross-linkable functional groups introduced into the polymer block (A), or as described later, a cross-linking agent having a functional group capable of reacting with the cross-linkable functional group is added. You may go. In the case of the reaction between the crosslinkable functional groups introduced into the polymer block (A), if a reactive silicon group is used as the crosslinkable functional group, the polymerization reaction for producing the block copolymer and the subsequent crosslink reaction can be efficiently performed. Can be done

The number average molecular weight (Mn) of the block copolymer of the present disclosure is preferably in the range of 10,000 to 500,000. When the number average molecular weight is 10,000 or more, sufficient strength as an elastomer material can be exhibited. In addition, if it is 500,000 or less, good moldability can be secured. The number average molecular weight is more preferably in the range of 20,000 to 400,000, more preferably 50,000 to 200,000.
The molecular weight distribution (Mw / Mn) obtained by dividing the value of the weight average molecular weight (Mw) of the block copolymer by the value of the number average molecular weight (Mn) is 1.5 or less in terms of moldability. Preferably, there is. It is more preferably at most 1.4, further preferably at most 1.3, even more preferably at most 1.2. The lower limit of the molecular weight distribution is 1.0.

<Production method of block copolymer>
The block copolymer of the present disclosure is not particularly limited as long as a block copolymer having the polymer block (A) and the acrylic polymer block (B) is obtained. Can be adopted. For example, a method using various control polymerization methods such as living radical polymerization and living anion polymerization, a method of coupling polymers having a functional group, and the like can be used. Among them, the living radical polymerization method is preferred because the operation is simple and the method can be applied to a wide range of monomers.

The living radical polymerization may employ any process such as a batch process, a semi-batch process, a dry continuous polymerization process, and a continuous stirred tank process (CSTR). Further, the polymerization method can be applied to various aspects such as bulk polymerization without using a solvent, solvent-based solution polymerization, aqueous-based emulsion polymerization, mini-emulsion polymerization, and suspension polymerization.
There is no particular limitation on the type of living radical polymerization method, and reversible addition-fragmentation chain transfer polymerization method (RAFT method), nitroxy radical method (NMP method), atom transfer radical polymerization method (ATRP method), organic tellurium compound , A polymerization method using an organic antimony compound (SBRP method), a polymerization method using an organic bismuth compound (BIRP method), and an iodine transfer polymerization method. Among these, the RAFT method, the NMP method, and the ATRP method are preferred from the viewpoint of controllability of polymerization and easiness of implementation.

In the RAFT method, controlled polymerization proceeds through a reversible chain transfer reaction in the presence of a specific polymerization controller (RAFT agent) and a general free radical polymerization initiator. As the RAFT agent, various known RAFT agents such as dithioester compounds, xanthate compounds, trithiocarbonate compounds, and dithiocarbamate compounds can be used.
As the RAFT agent, a monofunctional agent having only one active site may be used, or a bifunctional or higher functional agent may be used. It is preferable to use a bifunctional RAFT agent from the viewpoint that the block copolymer having the A- (BA) n-type structure is easily obtained efficiently.
The amount of the RAFT agent used is appropriately adjusted depending on the type of the monomer and the RAFT agent to be used.

Known radical polymerization initiators such as azo compounds, organic peroxides and persulfates can be used as the polymerization initiator used in the polymerization by the RAFT method. An azo compound is preferable in that a side reaction hardly occurs.
Specific examples of the azo compound include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), and 2,2′-azobis (4-methoxy-2, 4-dimethylvaleronitrile), dimethyl-2,2'-azobis (2-methylpropionate), 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane-1-) Carbonitrile), 2,2′-azobis [N- (2-propenyl) -2-methylpropionamide], 2,2′-azobis (N-butyl-2-methylpropionamide) and the like.
The radical polymerization initiator may be used alone or in combination of two or more.

  The use ratio of the radical polymerization initiator is not particularly limited, but from the viewpoint of obtaining a polymer having a smaller molecular weight distribution, the amount of the radical polymerization initiator to be used is preferably 0.5 mol or less per 1 mol of the RAFT agent. .2 mol or less is more preferable. Further, from the viewpoint of stably performing the polymerization reaction, the lower limit of the amount of the radical polymerization initiator to be used per 1 mol of the RAFT agent is 0.01 mol. Therefore, the amount of the radical polymerization initiator used per 1 mol of the RAFT agent is preferably in the range of 0.01 mol to 0.5 mol, and more preferably in the range of 0.05 mol to 0.2 mol.

  The reaction temperature at the time of the polymerization reaction by the RAFT method is preferably from 40 ° C to 100 ° C, more preferably from 45 ° C to 90 ° C, and further preferably from 50 ° C to 80 ° C. When the reaction temperature is at least 40 ° C., the polymerization reaction can proceed smoothly. On the other hand, when the reaction temperature is 100 ° C. or lower, side reactions can be suppressed, and restrictions on the initiator and the solvent that can be used are relaxed.

｛式中、Ｒ^１は炭素数１〜２のアルキル基又は水素原子であり、Ｒ^２は炭素数１〜２のアルキル基又はニトリル基であり、Ｒ^３は−（ＣＨ_２）ｍ−、ｍは０〜２であり、Ｒ^４、Ｒ^５は炭素数１〜４のアルキル基である。｝In the NMP method, a specific alkoxyamine compound having a nitroxide or the like is used as a living radical polymerization initiator, and polymerization proceeds via a nitroxide radical derived therefrom. In the present disclosure, the type of nitroxide radical to be used is not particularly limited, but from the viewpoint of polymerization control when polymerizing a monomer containing an acrylate, a compound represented by the general formula (2) may be used as a nitroxide compound. Is preferred.

In the formula, R ¹ is an alkyl group having 1 to 2 carbon atoms or a hydrogen atom, R ² is an alkyl group having 1 to ² carbon atoms or a nitrile group, and R ³ is-(CH ₂ ) m-, m Is 0 to 2, and R ⁴ and R ⁵ are an alkyl group having 1 to 4 carbon atoms. ｝

The nitroxide compound represented by the general formula (2) is primarily dissociated by heating at about 70 to 80 ° C., and causes an addition reaction with the vinyl monomer. At this time, a polyfunctional polymerization precursor can be obtained by adding a nitroxide compound to a vinyl monomer having two or more vinyl groups. Then, the vinyl monomer can be subjected to living polymerization by secondary dissociation of the polymerization precursor under heating.
In this case, since the polymerization precursor has two or more active sites in the molecule, a polymer having a narrower molecular weight distribution can be obtained. From the viewpoint of efficiently obtaining the block copolymer having the A- (BA) n-type structure, it is preferable to use a bifunctional polymerization precursor having two active sites in the molecule.
The amount of the nitroxide compound to be used is appropriately adjusted depending on the type of the monomer and the nitroxide compound used.

｛式中、Ｒ^４、Ｒ^５は炭素数１〜４のアルキル基である。｝When the block copolymer of the present disclosure is produced by the NMP method, the nitroxide radical represented by the general formula (3) is used in an amount of 0.001 to 0.2 mol per 1 mol of the nitroxide compound represented by the general formula (2). May be added in the range described above for polymerization.

中 In the formula, R ⁴ and R ⁵ are an alkyl group having 1 to 4 carbon atoms. ｝

  By adding 0.001 mol or more of the nitroxide radical represented by the general formula (3), the time required for the concentration of the nitroxide radical to reach a steady state is reduced. As a result, the polymerization can be controlled to a higher degree, and a polymer having a narrower molecular weight distribution can be obtained. On the other hand, if the amount of the nitroxide radical is too large, polymerization may not proceed. A more preferable addition amount of the nitroxide radical per 1 mol of the nitroxide compound is in the range of 0.01 to 0.5 mol, and a still more preferable addition amount is in the range of 0.05 to 0.2 mol.

  The reaction temperature in the NMP method is preferably from 50 ° C to 140 ° C, more preferably from 60 ° C to 130 ° C, further preferably from 70 ° C to 120 ° C, particularly preferably from 80 ° C to 120 ° C. It is as follows. When the reaction temperature is 50 ° C. or higher, the polymerization reaction can proceed smoothly. On the other hand, when the reaction temperature is 140 ° C. or lower, side reactions such as radical chain transfer tend to be suppressed.

  In the ATRP method, a polymerization reaction is generally performed using an organic halide as an initiator and a transition metal complex as a catalyst. As the organic halide as the initiator, a monofunctional one or a bifunctional or higher one may be used. It is preferable to use a bifunctional compound from the viewpoint that the block copolymer having the A- (BA) n-type structure is easily obtained efficiently. Further, as the kind of halogen, bromide and chloride are preferable.

  The reaction temperature in the ATRP method is preferably from 20 ° C to 200 ° C, more preferably from 50 ° C to 150 ° C. When the reaction temperature is 20 ° C. or higher, the polymerization reaction can proceed smoothly.

An A- (BA) n-type structure, such as an ABA triblock copolymer, comprising a polymer block (A) -acrylic polymer block (B) -polymer block (A) is obtained by a living radical polymerization method. In this case, for example, the desired block copolymer may be obtained by sequentially polymerizing each block. In this case, first, as a first polymerization step, a monomer containing 1% by mass to 70% by mass of styrenes and 30% by mass to 99% by mass of a maleimide compound is polymerized to obtain a polymer block (A). . Next, as a second polymerization step, an acrylic monomer is polymerized to obtain an acrylic polymer block (B). Further, as a third polymerization step, an ABA triblock copolymer is obtained by polymerizing a monomer containing 1% to 70% by mass of styrenes and 30% to 99% by mass of a maleimide compound. Can be. In this case, it is preferable to use the above-mentioned monofunctional polymerization initiator or polymerization precursor as the polymerization initiator. By repeating the second polymerization step and the third polymerization step, a higher-order block copolymer such as a tetrablock copolymer can be obtained.
In addition, it is preferable to produce the target product more efficiently by a method including the following two-stage polymerization step, since the target product can be obtained more efficiently. That is, as a first polymerization step, an acrylic monomer is polymerized to obtain an acrylic polymer block (B), and then, as a second polymerization step, 1% to 70% by weight of styrenes, and a maleimide compound A polymer containing 30% by mass or more and 99% by mass or less is polymerized to obtain a polymer block (A). Thereby, an ABA triblock copolymer consisting of the polymer block (A) -acrylic polymer block (B) -polymer block (A) can be obtained. In this case, it is preferable to use a bifunctional polymerization initiator or a polymerization precursor as the polymerization initiator. According to this method, the process can be simplified as compared with a case where each block is sequentially polymerized and manufactured. Further, by repeating the first polymerization step and the second polymerization step, a higher-order block copolymer such as a tetrablock copolymer can be obtained.

In the present disclosure, the polymerization of the block copolymer may be performed in the presence of a chain transfer agent, if necessary, regardless of the polymerization method.
As the chain transfer agent, known compounds can be used, and specifically, ethanethiol, 1-propanethiol, 2-propanethiol, 1-butanethiol, 2-butanethiol, 1-hexanethiol, 2-hexane Thiol, 2-methylheptane-2-thiol, 2-butylbutane-1-thiol, 1,1-dimethyl-1-pentanethiol, 1-octanethiol, 2-octanethiol, 1-decanethiol, 3-decanethiol, 1-undecanethiol, 1-dodecanethiol, 2-dodecanethiol, 1-tridecanethiol, 1-tetradecanethiol, 3-methyl-3-undecanethiol, 5-ethyl-5-decanethiol, tert-tetradecanethiol, -Hexadecanethiol, 1-heptadecanethiol and 1- In addition to alkylthiol compounds having an alkyl group having 2 to 20 carbon atoms, such as kutadecanethiol, mercaptoacetic acid, mercaptopropionic acid, 2-mercaptoethanol, and the like, and one or more of these can be used. Can be.

  In the present disclosure, a known polymerization solvent can be used in living radical polymerization. Specifically, aromatic compounds such as benzene, toluene, xylene and anisole; ester compounds such as methyl acetate, ethyl acetate, propyl acetate and butyl acetate; ketone compounds such as acetone and methyl ethyl ketone; dimethylformamide, acetonitrile, dimethyl sulfoxide, Alcohol, water and the like. Further, the polymerization may be carried out in the form of bulk polymerization without using a polymerization solvent.

<Elastomer composition>
The block copolymer of the present disclosure can be used alone or as an elastomer material, but may be in the form of a composition containing known additives and the like as necessary. In particular, when the block copolymer of the present disclosure includes a crosslinkable functional group in at least one of the polymer block (A) and the acrylic polymer block (B), a crosslinking agent capable of reacting with the functional group and crosslinking promotion. It is preferable that an elastomer having a small value of compression set can be obtained by blending an agent or the like and performing a heat treatment or the like as necessary.

When the block copolymer of the present disclosure includes a structural unit derived from a crosslinkable monomer having a carboxyl group, a polyamine, a polyfunctional isocyanate, or the like is preferably used as a crosslinker.
Examples of the polyvalent amine include aliphatic diamine compounds such as hexamethylene diamine, hexamethylene diamine carbamate, N, N'-dicinnamylidene-1,6-hexanediamine; and alicyclic compounds such as 4,4'-methylenebiscyclohexylamine carbamate. Diamine compound: 4,4'-methylenedianiline, m-phenylenediamine, 4,4'-diaminodiphenylether, 4,4 '-(m-phenylenediisopropylidene) diaaniline, 4,4'-(p-phenylenediamine Isopropylidene) diaaniline, 2,2'-bis [4- (4-aminophenoxy) phenyl] propane, 4,4'-diaminobenzanilide, m-xylylenediamine, p-xylylenediamine, 1,3,5 -Aromatic compounds such as benzenetriamine and 1,3,5-benzenetriaminomethyl; Family diamine compounds and the like.
Examples of the polyfunctional isocyanate include hexamethylene diisocyanate, dimethyl diphenylene diisocyanate, and isophorone diisocyanate.

  When a polyvalent amine is used, guanidine compounds such as 1,3-di-o-tolylguanidine and 1,3-diphenylguanidine; imidazole compounds such as 2-methylimidazole and 2-phenylimidazole; phosphoric acid, carbonic acid, bicarbonate Salts of weak acids, such as alkali metal salts (Li, Na, K) of acids such as acetic acid, stearic acid and lauric acid; third salts such as triethylenediamine, 1,8-diazabicyclo- [5.4.0] undecene-7; Tertiary phosphine compounds such as triphenylphosphine and tri (methyl) phenylphosphine; crosslinking assistants such as quaternary onium salts such as tetrabutylammonium bromide, tetrabutylammonium chloride and octadecyltri-n-butylammonium bromide Is preferably used in combination.

When the block copolymer of the present disclosure includes a structural unit derived from a crosslinkable monomer having an epoxy group, as a crosslinking agent, an organic carboxylic acid ammonium salt, a dithiocarbamate, a polyvalent carboxylic acid or an anhydride. , Quaternary ammonium salts or phosphonium salts are preferably used.
Examples of the organic ammonium carboxylate include ammonium benzoate.
Examples of the dithiocarbamate include zinc salts, such as dimethyldithiocarbamic acid, diethyldithiocarbamic acid, and dibenzyldithiocarbamic acid, iron salts, and tellurium salts.
Examples of the polycarboxylic acid include malonic acid, succinic acid, adipic acid, sebacic acid, dodecandioic acid, maleic acid, citric acid, tartaric acid, and phthalic acid. Examples of the quaternary ammonium salt include tetraethylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium bromide, n-dodecyltrimethylammonium bromide, octadecyltrimethylammonium bromide and the like. Examples of the phosphonium salt include triphenylbenzylphosphonium chloride, triphenylbenzylphosphonium bromide, triphenylbenzylphosphonium iodide, triethylbenzylphosphonium chloride, and tetrabutylphosphonium bromide.

When the block copolymer of the present disclosure includes a structural unit derived from a crosslinkable monomer having a hydroxyl group, a polyfunctional isocyanate or the like is preferably used as the crosslinking agent.
When the block copolymer of the present disclosure includes a structural unit derived from a crosslinkable monomer having a primary or secondary amino group, a polyfunctional isocyanate and a polyfunctional glycidyl compound are preferably used as the crosslinking agent.
When the block copolymer of the present disclosure contains a polymerizable unsaturated group, dithiol compounds such as 1,2-ethanedithiol, 1,4-butanethiol, 1,10-decanethiol, and 1,4-benzenethiol; Alternatively, an ene-thiol reaction with a polyvalent thiol such as a trithiol compound such as ethane-1,1,1-trithiol or 1,3,5-benzenetrithiol can be used.
When the crosslinkable group of the block copolymer of the present disclosure is a reactive silicon group, a crosslinking reaction occurs due to moisture, so that it is not necessary to add a crosslinking agent or the like.

  In addition, examples of the additives include a plasticizer, an oil, an antioxidant, an inorganic filler, a pigment, an antioxidant, and an ultraviolet absorber. The amount of the additive is preferably from 0% by mass to 10% by mass, more preferably from 0% by mass to 5% by mass, and still more preferably from 0% by mass to 2% by mass, based on the block copolymer. % By mass or less.

  A thermoplastic resin may be added for the purpose of adjusting the performance or processability of the elastomer composition containing the block copolymer of the present disclosure. Specific examples of the thermally active resin include polyolefin resins such as polyethylene and polypropylene, styrene resins such as polystyrene, vinyl resins such as polyvinyl chloride, polyester resins, and polyamide resins. Further, another elastomer may be added and mixed.

  The elastomer composition containing the block copolymer of the present disclosure exhibits good fluidity when heated to about 200 ° C. or more and 250 ° C. or less. For this reason, it can be applied to molding processing by various methods such as extrusion molding, injection molding, and casting molding.

Hereinafter, the present disclosure will be specifically described based on examples. Note that the present disclosure is not limited by these examples. In the following, “parts” and “%” mean parts by mass and% by mass, respectively, unless otherwise specified.
The methods for analyzing the polymers obtained in Production Examples, Examples and Comparative Examples are described below.

<Molecular weight measurement>
The obtained polymer was subjected to gel permeation chromatography (GPC) measurement under the following conditions to obtain a number average molecular weight (Mn) and a weight average molecular weight (Mw) in terms of polystyrene. The molecular weight distribution (Mw / Mn) was calculated from the obtained values.
○ Measurement conditions Column: Tosoh TSKgel SuperMultipore HZ-M x 4 Solvent: tetrahydrofuran Temperature: 40 ° C
Detector: RI
Flow rate: 600 μL / min

<Composition ratio of polymer>
The composition ratio of the obtained polymer was identified and calculated from ¹ H-NMR measurement.

<Glass transition temperature (Tg)>
The glass transition temperature (Tg) of the obtained polymer was determined from the intersection of the baseline of the heat flux curve obtained using a differential scanning calorimeter and the tangent at the inflection point. The heat flux curve was obtained by cooling about 10 mg of the sample to −50 ° C., maintaining the temperature for 5 minutes, increasing the temperature to 300 ° C. at 10 ° C./min, subsequently cooling to −50 ° C., maintaining the temperature for 5 minutes, The temperature was raised to 350 ° C. in min.
Measuring equipment: DSC6220 manufactured by SII Nanotechnology Inc.
Measurement atmosphere: under a nitrogen atmosphere The inflection points corresponding to the polymer block (A) and the polymer block (B) were obtained by performing differential scanning calorimetry of the block copolymers obtained in Examples and Comparative Examples. From which the Tg of each polymer block can be determined.

  Next, methods for evaluating elastomers in Examples and Comparative Examples are described below.

<Initial tensile properties>
100 parts of the block copolymer and 0.3 parts of Irganox 1010 (manufactured by BASF) as an antioxidant were dissolved in tetrahydrofuran (THF) to prepare a solution having a polymer concentration of 10%. This was poured into a mold, and THF was dried and distilled off to prepare a cast film having a thickness of about 1 mm.
Using the film obtained above as a sample, the tensile strength at break and the elongation at break under normal conditions (25 ° C.) were measured in accordance with JIS K6251.

<Heat aging resistance>
For the sample, a film having the same initial tensile properties was used.
The sample punched into a dumbbell type was put into an explosion-proof dryer at 150 ° C., and after 1000 hours, the sample was taken out. Next, the tensile strength at break and elongation at break under normal conditions (25 ° C.) were measured according to JIS K6251. The heat aging resistance was evaluated by calculating the elongation at break and the retention of the breaking strength with respect to the initial measured values.

<Oil resistance>
For the sample, a film having the same initial tensile properties was used.
The sample punched into a dumbbell type was immersed in engine oil (Nissan genuine engine oil “Motor Oil Extra Save X 10W-30 SJ”), heated to 150 ° C., and taken out after 1000 hours. Next, the taken-out sample was allowed to cool, and the swelling rate was evaluated from the weight change rate after gently wiping. Further, the same sample was measured for tensile strength at break and elongation at break under normal conditions (25 ° C.) in accordance with JIS K6251. The elongation at break and the retention of the breaking strength with respect to the initial measured values were calculated.

<Moldability>
The following items were evaluated for moldability.
(1) Fluidity The sample used was the same film as the initial tensile properties.
The evaluation was made according to the conditions of the heating temperature and the load when the melt flow rate (MFR) measured according to ASTM D1239 was 0.1 g / 10 min or more. It was judged that the one having the above-mentioned melt flow rate under low temperature and low load conditions had better fluidity.
(2) Deterioration of Resin The molecular weight of the sample before and after the MFR measurement was measured to calculate the rate of change, and evaluated based on the following criteria.
：: Change rate of less than 10% ×: Change rate of 10% or more (3) Appearance A molded article of 125 mm × 125 mm × 2 mm in thickness was injection-molded under the following conditions, and the obtained molded article was visually observed based on the following criteria. Was used to evaluate the appearance.
：: No wrinkles, irregularities or defects such as sacrifices are observed on the surface ×: Injection molding machine with defects such as wrinkles, irregularities or sacrifices on the surface: 100MSIII-10E (trade name, manufactured by Mitsubishi Heavy Industries, Ltd.)
Injection molding temperature: 240 ° C
Injection pressure: 30%
Injection time: 3sec
Mold temperature: 40 ° C

<Measurement of compression set>
Each composition obtained by the composition shown in Table 11 was measured according to the following procedure.
A film sample having a thickness of 2 mm was prepared according to the sample preparation procedure in the above initial tensile properties, and a disc-shaped molded body produced by laminating seven pieces cut into a disc shape having a diameter of 29 mm was hot-pressed at 200 ° C. The test piece having a height adjusted to 12.5 mm ± 0.5 mm was used as a test piece and measured by a compression set test specified in JIS K6262.
Specifically, at a standard temperature (23.2 ± 2 ° C.), the diameter and thickness of the test piece are 29.0 ± 0.5 mm (diameter) and 12.5 mm ± 0.5 mm (thickness), respectively. After confirming that there was, the test piece was sandwiched between compression plates provided with spacers having a thickness of 9.3 to 9.4 mm. After the specimen was held at 70 ° C. for 24 hours under the condition that the compression ratio of the specimen was 25% by volume, the thickness of the central part of the specimen after the compression plate was removed at 23 ° C. and left for 30 minutes was measured.
The measurement results were applied to the following compression set calculation formula to calculate the value of compression set (%).
Compression set _{(%) = (t 0 -t} 2) / (t 0 -t 1) × 100
(Where t ₀ is the original thickness (mm) of the test piece, t ₁ is the thickness of the spacer (mm), and t ₂ is the thickness (mm) of the test piece 30 minutes after being removed from the compression device. Indicates)
After the compression release, the value of the compression set when the test piece completely returns to the size and shape before compression is 0%, and the size and shape do not return to the original shape even after release from compression. Since the value of the compression set in this case is 100%, the smaller the value of the compression set is between 0% and 100%, the better the recovery.

<D hardness>
A film having a thickness of 2 mm prepared in the same procedure as the compression set described above was allowed to stand in a thermo-hygrostat (temperature 23 ° C., relative humidity 50%) for 24 hours or more to stabilize the state. Again, the D hardness was measured according to JIS K 7215 “Durometer hardness test method for plastics”.

<< Synthesis of RAFT agent >>
Synthesis Example 1
(Synthesis of 1,4-bis (n-dodecylsulfanylthiocarbonylsulfanylmethyl) benzene)
1-dodecanethiol (42.2 g), a 20% aqueous KOH solution (63.8 g), and trioctylmethylammonium chloride (1.5 g) were added to an eggplant-shaped flask, and the mixture was cooled in an ice bath, and carbon disulfide (15.9 g) was added. ) And tetrahydrofuran (hereinafter also referred to as “THF”) (38 ml), and the mixture was stirred for 20 minutes. A THF solution (170 ml) of α, α'-dichloro-p-xylene (16.6 g) was added dropwise over 30 minutes. After reacting at room temperature for 1 hour, the mixture was extracted from chloroform, washed with pure water, dried over anhydrous sodium sulfate, and concentrated with a rotary evaporator. The obtained crude product is purified by column chromatography and then recrystallized from ethyl acetate to give 1,4-bis (n-dodecylsulfanylthiocarbonylsulfanylmethyl) benzene represented by the following formula (4). (Hereinafter also referred to as "DLBTTC") in a yield of 80%. ^{From 1} H-NMR measurement, peaks of the target compound were confirmed at 7.2 ppm, 4.6 ppm, and 3.4 ppm.

<< Production of acrylic polymer block (B) >>
Production Example 1
(Production of polymer A)
RAFT agent (DLBTTC) (4.28 g) obtained in Synthesis Example 1 and 2,2′-azobis-2-methylbutyronitrile (hereinafter also referred to as “ABN-E”) in a 1 L flask equipped with a stirrer and a thermometer. (0.25 g), ethyl acrylate (651 g) and anisole (287 g) were charged, sufficiently degassed by nitrogen bubbling, and polymerization was started in a thermostat at 60 ° C. After 3 hours and 30 minutes, the reaction was stopped by cooling to room temperature. The above polymer solution was purified by reprecipitation from hexane and vacuum dried to obtain a polymer A. The molecular weight of the obtained polymer A was Mn69200, Mw75500, and Mw / Mn1.09 by GPC (gel permeation chromatography) measurement (polystyrene conversion).

Production Examples 2, 6, 7
(Production of polymers B, F and G)
Polymers B, F, and G were obtained by performing the same operations as in Production Example 1 except that the amounts of DLBTTC, ABN-E, and anisole used were as shown in Table 1 and the reaction time was appropriately adjusted. The molecular weight of each polymer was measured and is shown in Table 1.

Production Example 3
(Production of polymer C)
Polymer C was obtained in the same manner as in Production Example 1 except that methyl acrylate was used instead of ethyl acrylate, and the amount charged was changed as shown in Table 1 and the reaction time was appropriately adjusted. The molecular weight of polymer C was measured and is shown in Table 1.

Production Example 4
(Production of polymer D)
Using n-butyl acrylate and 2-methoxyethyl acrylate in addition to ethyl acrylate, the same operation as in Production Example 1 was performed, except that the amount charged was changed as shown in Table 1 and the reaction time was appropriately adjusted. Then, a polymer D was obtained. The molecular weight of Polymer D was measured and is shown in Table 1. Further, when the composition ratio of ethyl acrylate, n-butyl acrylate and 2-methoxyethyl acrylate in the polymer was determined from ¹ H-NMR measurement, ethyl acrylate / n-butyl acrylate / 2-acrylate acrylate was determined. Methoxyethyl was 49/25/26 wt%.

Production Example 5
(Production of polymer E)
In addition to ethyl acrylate, n-butyl acrylate was used, the charge amount was changed as shown in Table 1, and the same operation as in Production Example 1 was performed except that the reaction time was appropriately adjusted. Obtained. The molecular weight of polymer J was measured and is shown in Table 1. Further, when the composition ratio of ethyl acrylate and n-butyl acrylate in the polymer was determined from ¹ H-NMR measurement, it was determined that ethyl acrylate / n-butyl acrylate = 25/75 wt%.

Production Example 8
(Production of polymer H)
In a 1 L flask equipped with a stirrer and a thermometer, 2-methyl-2- [N-tert-butyl-N- (1-diethylphosphono-2,2-dimethylpropyl) -N-oxyl] propionic acid (2.48 g) ), Hexanediol diacrylate (0.72 g) and isopropyl alcohol (20 g) were charged, sufficiently degassed by nitrogen bubbling, and the reaction was started in a thermostat at 100 ° C. One hour later, after cooling to room temperature, the solvent was distilled off under reduced pressure. The residue was charged with N-tert-butyl-1-diethylphosphono-2,2-dimethylpropyl nitroxide (0.03 g), ethyl acrylate (651 g) and anisole (289 g), and sufficiently degassed with nitrogen bubbling. Polymerization was started in a constant temperature bath at ℃. After 8 hours, the reaction was stopped by cooling to room temperature. The above polymer solution was purified by reprecipitation from hexane and vacuum dried to obtain a polymer H. The molecular weight of the obtained polymer H was measured and is shown in Table 1.

Production Example 9
(Production of Polymer I)
A 1 L flask equipped with a stirrer and a thermometer was charged with copper (I) bromide (4.28 g), pentamethyldiethylenetriamine (7.90 g), ethyl acrylate (651 g), and anisole (280 g), and sufficiently removed by nitrogen bubbling. I noticed. After adding ethylene bis (2-bromoisobutyrate) (1.27 g), polymerization was started in a constant temperature bath at 70 ° C. After 6 hours, the reaction was stopped by cooling to room temperature. The above polymer solution was purified by reprecipitation from hexane and vacuum dried to obtain a polymer I. The molecular weight of the obtained polymer I was measured and is shown in Table 1.

Production Example 10
(Production of polymer J)
In place of ethyl acrylate, n-butyl acrylate was used, the charge amount was changed as shown in Table 1, and the same operation as in Production Example 1 was performed except that the reaction time was appropriately adjusted. Obtained. The molecular weight of polymer J was measured and is shown in Table 1.

The details of the compounds shown in Table 1 are as follows.
MA: methyl acrylate EA: ethyl acrylate C-1: 2-methoxyethyl acrylate nBA: n-butyl acrylate SG1-MAA: 2-methyl-2- [N-tert-butyl-N- (1-diethyl) [Phosphono-2,2-dimethylpropyl) -N-oxyl] propionic acid (Nitroxide compound manufactured by Arkema)
SG1: N-tert-butyl-1-diethylphosphono-2,2-dimethylpropyl nitroxide (Nitroxide radical manufactured by Arkema)
ABN-E: 2,2'-azobis (2-methylbutyronitrile)

≫Manufacture of block copolymer≫
Example 1
(Production of block copolymer 1)
In a 1 L flask equipped with a stirrer and a thermometer, polymer A (87.0 g), ABN-E (0.10 g), N-phenylmaleimide (14.6 g), styrene (49.8 g) obtained in Production Example 1 were placed. ) And anisole (342 g) were charged, sufficiently degassed by nitrogen bubbling, and polymerization was started in a 60 ° C. constant temperature bath. After 3 hours, the reaction was stopped by cooling to room temperature. The above polymerization solution was purified by reprecipitation from methanol and vacuum dried to obtain a block copolymer 1. As a result of measuring the molecular weight of the obtained block copolymer 1, Mn98500, Mw109000, and Mw / Mn were 1.11.
The block copolymer 1 is a triblock copolymer having a structure of polymer block (A) -acrylic polymer block (B) -polymer block (A). ^When the composition ratio of N-phenylmaleimide and styrene in the polymer block (A) was determined from ¹ H-NMR measurement, it was found that N-phenylmaleimide / styrene = 32/68 wt%, and the polymer block (A) and acryl The composition ratio of the system polymer block (B) was (A) / (B) = 30/70 wt%. The block copolymer 1 was evaluated as an elastomer, and the results are shown in Table 8.

Examples 2 to 24 and Comparative Examples 1 to 4
The same operation as in Example 1 was performed except that the types and amounts of the raw materials charged in the flask were changed as described in Tables 2 to 4 and the reaction time was appropriately adjusted, and the block copolymers 2 to 24 and 26 were used. ~ 29 was obtained. Molecular weight of each block copolymer, composition ratio of polymer block (A) by ¹ H-NMR measurement, and composition ratio of polymer block (A) and acrylic polymer block (B) in block copolymer Are described in Tables 5 to 7.

The SP value of the polymer block (A) and that of the acrylic polymer block (B) were determined by the composition ratio of the polymer block (A) and the composition ratio of the acrylic polymer block (B) measured by ¹ H-NMR. It was used and calculated from the above-mentioned calculation formula (Equation 1) and described in Tables 5 to 7. In addition, based on the differential scanning calorimetry of the block copolymers 1 to 24 and 26 to 29, the Tg of the polymer block (A) and the acrylic polymer block (B) were determined and are shown in Tables 5 to 7.

Example 25
In a 1 L flask equipped with a stirrer and a thermometer, 2-{[(2-carboxyethyl) sulfanylthiocarbonyl] sulfanyl} propanoic acid (0.80 g), ABN-E (0.12 g), and N-phenylmaleimide (27. 3 g), styrene (16.4 g) and anisole (89.4 g) were charged, sufficiently degassed by nitrogen bubbling, and polymerization was started in a 70 ° C. constant temperature bath. Two hours later, after cooling to room temperature to stop the reaction, ethyl acrylate (220.8 g) and anisole (34.4 g) were charged, sufficiently degassed by nitrogen bubbling, and polymerization was started in a constant temperature bath at 70 ° C. . After 6 hours, the reaction was cooled to room temperature to stop the reaction, N-phenylmaleimide (27.3 g), styrene (16.4 g) and anisole (159.3 g) were charged, and the mixture was sufficiently degassed by bubbling with nitrogen. The polymerization was started in a constant temperature bath. Eight hours later, anisole (195.9 g) was charged, and the reaction was stopped by cooling to room temperature. The above polymerization solution was purified by reprecipitation from methanol and vacuum dried to obtain a block copolymer 25. As a result of measuring the molecular weight of the obtained block copolymer 25, Mn86500, Mw124000, and Mw / Mn were 1.43.
The above 2-{[(2-carboxyethyl) sulfanylthiocarbonyl] sulfanyl} propanoic acid is a monofunctional RAFT agent, and the obtained polymer is a polymer block (A) -acrylic polymer block (B) -A triblock copolymer having the structure of the polymer block (A). ^When the composition ratio of N-phenylmaleimide and styrene in the polymer block (A) was determined from ¹ H-NMR measurement, it was found that N-phenylmaleimide / styrene = 62/38 wt%, and the polymer block (A) and acryl The composition ratio of the system polymer block (B) was (A) / (B) = 31/69 wt%. The SP value of the polymer block (A) was 13.0 and Tg was 210 ° C., and the SP value of the acrylic polymer block (B) was 10.2 and Tg was −20 ° C.

Details of the compounds shown in Tables 2 to 7 are as follows.
PhMI: N-phenylmaleimide MI: (N-unsubstituted) maleimide EtMI: N-ethylmaleimide BuMI: Nn-butylmaleimide St: Styrene αMeSt: α-methylstyrene ACMO: Acryloylmorpholine IBXA: Isobornyl acrylate MMA: Methacryl Methyl acrylate MAh: Maleic anhydride AA: Acrylic acid GMA: Glycidyl methacrylate KBM-503: 3-methacryloxypropyltrimethoxysilane (trade name, manufactured by Shin-Etsu Silicone Co., Ltd.)

  For each block copolymer, the mechanical properties at the initial stage and after the heat resistance and oil resistance tests were evaluated. The results are shown in Tables 8 to 10 together with the swelling ratio and moldability after the oil resistance test.

Examples 1 to 25 correspond to the block copolymer of the present disclosure, and all showed good values in both initial breaking elongation and breaking strength. Further, it was confirmed that even under severe conditions of 150 ° C. and 1000 hours, excellent heat resistance and oil resistance were exhibited. Above all, Examples 9 and 10 using (unsubstituted) maleimide and N-ethylmaleimide as the maleimide compound, Examples 13 and 14 in which the polymer block (A) has a structural unit derived from an amide group-containing vinyl compound, and No. 14 showed an extremely low swelling ratio and excellent oil resistance.
On the other hand, Comparative Example 1 was insufficient in heat resistance and oil resistance, and Comparative Example 2 was insufficient in oil resistance because the structural units derived from the maleimide compound in the polymer block (A) were small. Was. In Comparative Example 3, the polymer block (A) has no structural unit derived from styrenes. The fluidity was not sufficient, and the moldability was poor.

Experimental Examples 1 to 6
Each raw material was blended as shown in Table 11 to obtain an elastomer composition. However, for Experimental Examples 1 to 4, each raw material component was charged into a batch type kneader “Plastograph EC50” (manufactured by Brabender) heated to 170 ° C. for the purpose of causing a crosslinking reaction, and 100 rpm / min. The mixture was melt-kneaded at a rotation speed for 10 minutes. The entire amount of the kneaded material in the molten state was taken out and cooled at room temperature to obtain an elastomer composition.
The blending of the elastomer composition includes hexamethylene diamine carbamate “Cheminox AC-6” (trade name) manufactured by Unimatex, zinc dimethyldithiocarbamate “Noxeller PZ” (trade name) manufactured by Ouchi Shinko Chemical Co., Ltd., and dimethyldithiocarbamic acid Nikko "Noxeller TTFE" (trade name) was used.

  In Experimental Examples 1 to 5 using a block copolymer having a crosslinkable functional group in the polymer block (A), after performing a crosslinking reaction under the conditions shown in Table 11, compression set of the obtained cured product was obtained. Was evaluated. On the other hand, for Experimental Example 6 using a block copolymer having no crosslinkable functional group in the polymer block (A), the compression set was evaluated without performing any special treatment such as heating. Table 11 shows the results.

  As is clear from Table 11, in Examples 1 to 5 in which the block copolymer having a crosslinkable functional group was crosslinked in the polymer block (A), the block polymer 3 having no crosslinkable functional group was used. As compared with Experimental Example 6, a result excellent in compression set was observed.

The block copolymer of the present disclosure exhibits good rubber elasticity and also has excellent moldability. For this reason, it can be widely applied in fields such as packing materials, gaskets or hose materials of automobile parts, electric appliances and medical products, adhesive raw materials, architectural / civil engineering materials, daily necessities and the like.
Further, according to the block copolymer of the present disclosure, an elastomer material exhibiting extremely high heat resistance and oil resistance can be obtained. Therefore, among the above, for example, in automotive applications, it is suitably used as a sealing material, a packing, a tube, a hose, an engine cover, a tank cap, and the like, particularly as parts in an engine room. As an electric material, it is suitably used for heat-generating home appliances such as an oven, a toaster, an IH heater, an electric heater, and a hot air heater.
The elastomer composition containing the block copolymer of the present disclosure can be molded and processed into a desired shape to produce an automobile part, a home appliance / OA equipment part, a medical equipment part, a packaging material, a civil engineering building material, an electric wire, It can be suitably used as a material in a wide range of fields such as miscellaneous goods.

Claims (16)

A block copolymer having a polymer block (A) containing a structural unit derived from styrenes and a maleimide compound, and an acrylic polymer block (B),
The block copolymer has an A- (BA) n structure,
The polymer block (A) has a structural unit derived from a maleimide compound in an amount of 30% by mass or more and 99% by mass or less based on all structural units of the polymer block (A), and has a glass transition temperature (Tg). Is a polymer of 150 ° C. or higher,
A block copolymer, wherein the acrylic polymer block (B) is a polymer having a solubility parameter (SP value) of 9.9 or more and a Tg of 20 ° C. or less.   The block copolymer according to claim 1, wherein the solubility parameter (SP value) of the polymer block (A) is 10.0 or more.   3. The block copolymer according to claim 1, wherein the polymer block (A) has 1% by mass to 70% by mass of structural units derived from styrene based on all structural units of the polymer block (A). 4. Polymer. The block copolymer according to any one of claims 1 to 3, wherein the maleimide compound contains at least one compound represented by the general formula (1).

[In the formula, R ¹ represents hydrogen, an alkyl group having 1 to 3 carbon atoms, or PhR ² . However, Ph represents a phenyl group, R ² represents hydrogen, hydroxy group, an alkoxy group having 1 to 2 carbon atoms, an acetyl group or a halogen. ]   The block copolymer according to any one of claims 1 to 4, wherein the polymer block (A) further has a structural unit derived from an amide group-containing vinyl compound.   The block copolymer according to any one of claims 1 to 5, wherein at least one of the polymer block (A) and the acrylic polymer block (B) has a crosslinkable functional group.   The crosslinkable functional group is derived from a crosslinkable monomer, and the structural unit derived from the crosslinkable monomer is at least 0.01 mol% based on all structural units of the polymer block (A). The block copolymer according to claim 6, which has a content of 60 mol% or less.   The block copolymer according to any one of claims 1 to 7, wherein the number average molecular weight is 10,000 or more and 500,000 or less. The block copolymer according to claim 8, wherein the number average molecular weight is from 50,000 to 200,000. The block copolymer according to any one of claims 1 to 9, wherein the weight average molecular weight / number average molecular weight is 1.5 or less. The block copolymer according to any one of claims 1 to 10, wherein the glass transition temperature of the polymer block (B) is -10C or lower. A method for producing a polymer block (A) containing a structural unit derived from styrenes and a maleimide compound and a block copolymer having an acrylic polymer block (B) by a living radical polymerization method,
The block copolymer has an A- (BA) n structure,
The polymer block (A) has a structural unit derived from a maleimide compound in an amount of 30% by mass or more and 99% by mass or less based on all structural units of the polymer block (A), and has a Tg of 150 ° C or more. A polymer,
The acrylic polymer block (B) is a polymer having a solubility parameter (SP value) of 9.9 or more and a Tg of 20 ° C. or less.
Method. A step of polymerizing a monomer containing 1% to 70% by mass of styrenes and 30% to 99% by mass of a maleimide compound to obtain the block (A) as a first polymerization step;
Next, as a second polymerization step, a step of polymerizing an acrylic monomer to obtain the polymer block (B),
The third polymerization step further includes a step of polymerizing a monomer containing 1% to 70% by mass of styrenes and 30% to 99% by mass of a maleimide compound to obtain the block (A).
A method for producing the block copolymer according to claim 12 . A step of polymerizing an acrylic monomer to obtain the block (B) as a first polymerization step;
The second polymerization step includes a step of polymerizing a monomer containing 1% to 70% by mass of styrenes and 30% to 99% by mass of a maleimide compound to obtain the polymer block (A).
A method for producing the block copolymer according to claim 12 . An elastomer comprising the block copolymer according to any one of claims 1 to 11 . An automotive elastomer comprising the block copolymer according to any one of claims 1 to 11 .