JP7478391B2 - Polar group-containing olefin copolymer - Google Patents

Description

Subject to Article 30, Paragraph 2 of the Patent Act Publisher: Wiley-VCH Verlag GmbH & Co. KGaA Publication Name: Angew. Chem. Int. Ed. 2019, 58, 12955-12959 Issue date: July 19, 2019

This disclosure relates to an olefin copolymer that is easily decomposed.

Polyolefin resins such as polyethylene and polypropylene are widely used in various industrial fields because they are stable against light, oxygen, acids, and alkalis. However, sometimes their high stability can be a problem. For example, if polyolefins are accidentally dumped in the natural environment, they will remain there almost indefinitely without being naturally decomposed. In recent years, this has come to be called "marine plastic," and there has been growing criticism that it is an environmental disaster that damages the ecosystem.
Condensation polymerization polymers, such as polyesters such as polylactic acid, are well known as easily degradable polymers. However, these polymers have a structure containing heteroatoms such as carbon-oxygen bonds in the polymer backbone, and therefore cannot be used in the same way as conventional polyolefins.
For this reason, research has been conducted into how to make polyolefin resins more easily decomposable naturally (for example, Patent Documents 1 and 2). However, the reality is that no sufficient technology has yet been developed.

On the other hand, as polyolefins having a polar functional group in the main chain, copolymers obtained by copolymerization of α-olefins with carbon monoxide are known. In this case, copolymers with olefins having a carbonyl group introduced in the main chain are obtained as shown in FIG. 6 (for example, Patent Documents 3 and 4).
On the other hand, polar group-containing olefin copolymers include copolymers having ethylene and vinyl ketones, such as acrylic esters, as polar functional groups, in which the polar functional groups are introduced into the side chains of the polymer chains, as shown in FIG. 7 (Patent Document 5).

U.S. Pat. No. 5,321,065 Chinese Patent No. 1205260 U.S. Pat. No. 3,694,412 U.S. Pat. No. 3,689,460 Patent No. 6309206

The present application aims to provide a polar group-containing olefin copolymer that has a structure similar to that of conventional polyolefin resins but can be easily decomposed under specific conditions such as light irradiation, and a resin composition using the olefin copolymer.

The polar group-containing olefin copolymer of the present disclosure comprises a structural unit (A) derived from one or more monomers selected from the group consisting of ethylene and olefins having 3 to 20 carbon atoms;
A structural unit (B) represented by the following general formula (I),
The present invention is characterized by comprising:

（一般式（Ｉ）中、Ｒ^ｘおよびＲ^ｙは、それぞれ独立して、酸素原子、硫黄原子、ハロゲン原子、及び窒素原子からなる群より選ばれる少なくとも１種を含む官能基及び脂肪族炭化水素基からなる群より選ばれる少なくとも１種の置換基で置換されていても良い、炭素数６～３０の芳香族炭化水素基または炭素数２～８の芳香族複素環基であり、Ｒ^ｘとＲ^ｙは－Ｏ－、－Ｓ－、－ＮＲ^ｚ－（ここでＲ^ｚは水素原子、炭素数１～６のアシル基又は炭素数１～６の脂肪族炭化水素基）、脂肪族炭化水素基、若しくはこれらの組み合わせを介して互いに結合して７～１０員環の環を形成していても良い。）

(In general formula (I), R ^x and R ^y each independently represent an aromatic hydrocarbon group having 6 to 30 carbon atoms or an aromatic heterocyclic group having 2 to 8 carbon atoms which may be substituted with at least one substituent selected from the group consisting of a functional group containing at least one selected from the group consisting of an oxygen atom, a sulfur atom, a halogen atom, and a nitrogen atom, and an aliphatic hydrocarbon group, and R ^x and R ^y may be bonded to each other via -O-, -S-, -NR ^z - (wherein R ^z is a hydrogen atom, an acyl group having 1 to 6 carbon atoms, or an aliphatic hydrocarbon group having 1 to 6 carbon atoms), an aliphatic hydrocarbon group, or a combination thereof to form a 7-10-membered ring.)

In the polar group-containing olefin copolymer of the present disclosure, it is preferable from the viewpoint of the production efficiency of the copolymer that the structural unit (B) represented by the general formula (I) is derived from one or more monomers selected from the group consisting of polar group-containing monomers represented by the following general formula (1).

（一般式（１）中、Ｒ^ｘおよびＲ^ｙは、それぞれ独立して、酸素原子、硫黄原子、ハロゲン原子、及び窒素原子からなる群より選ばれる少なくとも１種を含む官能基及び脂肪族炭化水素基からなる群より選ばれる少なくとも１種の置換基で置換されていても良い、炭素数６～３０の芳香族炭化水素基または炭素数２～８の芳香族複素環基であり、Ｒ^ｘとＲ^ｙは－Ｏ－、－Ｓ－、－ＮＲ^ｚ（ここでＲ^ｚは水素原子、炭素数１～６のアシル基又は炭素数１～６の脂肪族炭化水素基）－、脂肪族炭化水素基、若しくはこれらの組み合わせを介して互いに結合して７～１０員環の環を形成していても良い。）

(In general formula (1), R ^x and R ^y are each independently an aromatic hydrocarbon group having 6 to 30 carbon atoms or an aromatic heterocyclic group having 2 to 8 carbon atoms which may be substituted with at least one substituent selected from the group consisting of a functional group containing at least one selected from the group consisting of an oxygen atom, a sulfur atom, a halogen atom, and a nitrogen atom, and an aliphatic hydrocarbon group, and R ^x and R ^y may be bonded to each other via -O-, -S-, -NR ^z (wherein R ^z is a hydrogen atom, an acyl group having 1 to 6 carbon atoms, or an aliphatic hydrocarbon group having 1 to 6 carbon atoms)-, an aliphatic hydrocarbon group, or a combination thereof to form a 7-10-membered ring.)

The polar group-containing olefin copolymer of the present disclosure may further contain structural units (C) derived from one or more monomers selected from the group consisting of polar group-containing monomers (c-1) represented by the following general formula (2) and polar group-containing monomers (c-2) represented by the following general formula (3):

（一般式（２）中、Ｒ^１とＲ^２は、それぞれ独立して、水素原子、炭素数１～３０のエステル基、炭素数１～３０のアシルオキシ基、炭素数１～３０のアルコキシ基、炭素数６～３０のアリールオキシ基、シアノ基、炭素数１～３０の炭化水素基で置換されていても良いアミノ基、炭素数１～３０の炭化水素基で置換されていても良いアミド基、炭素数１～３０の炭化水素基で置換されていても良いイミノ基、炭素数１～３０のハロゲン置換炭化水素基、又は、酸素原子、硫黄原子、窒素原子及びリン原子からなる群より選ばれる少なくとも１種を含む官能基で置換されていても良い炭素数１～３０の炭化水素基であり、Ｒ^１とＲ^２の少なくとも１つは、酸素原子及び窒素原子の少なくとも１種を含む基である。）

(In the general formula (2), R ¹ and R ² are each independently a hydrogen atom, an ester group having 1 to 30 carbon atoms, an acyloxy group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, a cyano group, an amino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, an amide group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, an imino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, a halogen-substituted hydrocarbon group having 1 to 30 carbon atoms, or a hydrocarbon group having 1 to 30 carbon atoms which may be substituted with a functional group containing at least one selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom, and a phosphorus atom, and at least one of R ¹ and R ² is a group containing at least one of an oxygen atom and a nitrogen atom.)

（一般式（３）中、Ｒ^３～Ｒ^１０は、それぞれ独立して、水素原子、ハロゲン原子、又は、炭素数１～２０の炭化水素基である。ｎは０又は正の整数を示し、ｎが２以上の場合には、Ｒ^７～Ｒ^１０は、それぞれの繰り返し単位の中で、それぞれ同一でも異なっていてもよい。Ｒ^１１～Ｒ^１４は、それぞれ独立して、水素原子、炭素数１～３０のエステル基、炭素数１～３０のアシルオキシ基、炭素数１～３０のアルコキシ基、炭素数６～３０のアリールオキシ基、シアノ基、炭素数１～３０の炭化水素基で置換されていても良いアミノ基、炭素数１～３０の炭化水素基で置換されていても良いアミド基、炭素数１～３０の炭化水素基で置換されていても良いイミノ基、又は、酸素原子、硫黄原子、窒素原子及びリン原子からなる群より選ばれる少なくとも１種を含む官能基で置換されていても良い炭素数１～３０の炭化水素基であり、Ｒ^１１～Ｒ^１４の少なくとも１つは、酸素原子及び窒素原子の少なくとも１種を含む基である。Ｒ^１１及びＲ^１２、並びに、Ｒ^１３及びＲ^１４は、各々一体化して２価の有機基を形成してもよく、Ｒ^１１又はＲ^１２と、Ｒ^１３又はＲ^１４とは、互いに環を形成していてもよい。）

(In general formula (3), R ³ to R ¹⁰ are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms. n is 0 or a positive integer, and when n is 2 or more, R ⁷ to R ¹⁰ may be the same or different in each repeating unit. R ¹¹ to R ¹⁴ are each independently a hydrogen atom, an ester group having 1 to 30 carbon atoms, an acyloxy group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, a cyano group, an amino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, an amide group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, an imino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, ^or a hydrocarbon group having 1 to 30 carbon atoms which may be substituted with a functional group containing at least one selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom, and a phosphorus atom; and At least one ^of R ¹¹ and R ¹² and R 13 and R ¹⁴ is a group containing at least one of an oxygen atom and a nitrogen atom. R 11 and R ¹² , and R ¹³ and R 14 may be bonded together to form a divalent organic group, and R ¹¹ or R 12 and R ¹³ or R ¹⁴ may form a ring together.

In the polar group-containing olefin copolymer of the present disclosure, it is preferable that the structural unit (A) is a structural unit derived from ethylene from the viewpoint of polymer production efficiency.

The polar group-containing olefin copolymer of the present disclosure may be an easily decomposable resin material.
The polar group-containing olefin copolymer of the present disclosure may be a photodegradable resin material.

The resin composition of the present disclosure is characterized by containing the polar group-containing olefin copolymer of the present disclosure.

According to the present disclosure, it is possible to provide a polar group-containing olefin copolymer that has a structure similar to that of conventional polyolefin resins, but can be easily decomposed under specific conditions such as light irradiation, and a resin composition using the olefin copolymer.

FIG. 1 shows a schematic diagram of the structure of the polar group-containing olefin copolymer of the present disclosure. FIG. 2 shows the results of ¹³ C-NMR measurement of the polar group-containing olefin copolymer 1 of Examples 1 and 2. FIG. 3 shows the results of ¹³ C-NMR measurement of the polar group-containing olefin copolymer 2 of Example 3. FIG. 4 shows the results of ¹³ C-NMR measurement of the comparative polar group-containing olefin copolymer i of Comparative Example 1. FIG. 5 shows the results of ¹³ C-NMR measurement of the comparative polar group-containing olefin copolymer ii of Comparative Example 2. FIG. 6 shows a schematic diagram of the structure of a conventional ethylene-carbon monoxide copolymer. FIG. 7 shows a schematic diagram of the structure of a conventional ethylene and acrylate copolymer. FIG. 8 shows the results of ¹ H-NMR measurement of the polar group-containing olefin copolymer 2 of Example 3 before and after ultraviolet irradiation.

Hereinafter, the polar group-containing olefin copolymer of the present disclosure will be described in detail for each item. In this specification, "(meth)acrylic acid" refers to each of acrylic acid and methacrylic acid, and "(meth)acryloyl" refers to each of acryloyl and methacryloyl. In addition, in this specification, "to" indicating a numerical range is used to mean that the numerical values written before and after it are included as the lower limit and upper limit.

I. Polar Group-Containing Olefin Copolymer The polar group-containing olefin copolymer of the present disclosure comprises a structural unit (A) derived from one or more monomers selected from the group consisting of ethylene and olefins having 3 to 20 carbon atoms;
and a structural unit (B) represented by the following general formula (I):

（一般式（Ｉ）中、Ｒ^ｘおよびＲ^ｙは、それぞれ独立して、酸素原子、硫黄原子、ハロゲン原子、及び窒素原子からなる群より選ばれる少なくとも１種を含む官能基及び脂肪族炭化水素基からなる群より選ばれる少なくとも１種の置換基で置換されていても良い、炭素数６～３０の芳香族炭化水素基または炭素数２～８の芳香族複素環基であり、Ｒ^ｘとＲ^ｙは－Ｏ－、－Ｓ－、－ＮＲ^ｚ（ここでＲ^ｚは水素原子、炭素数１～６のアシル基又は炭素数１～６の脂肪族炭化水素基）－、脂肪族炭化水素基、若しくはこれらの組み合わせを介して互いに結合して７～１０員環の環を形成していても良い。）

(In general formula (I), R ^x and R ^y each independently represent an aromatic hydrocarbon group having 6 to 30 carbon atoms or an aromatic heterocyclic group having 2 to 8 carbon atoms which may be substituted with at least one substituent selected from the group consisting of a functional group containing at least one selected from the group consisting of an oxygen atom, a sulfur atom, a halogen atom, and a nitrogen atom, and an aliphatic hydrocarbon group, and R ^x and R ^y may be bonded to each other via -O-, -S-, -NR ^z (wherein R ^z is a hydrogen atom, an acyl group having 1 to 6 carbon atoms, or an aliphatic hydrocarbon group having 1 to 6 carbon atoms)-, an aliphatic hydrocarbon group, or a combination thereof to form a 7-10-membered ring.)

As shown in FIG. 1 , the polar group-containing olefin copolymer of the present disclosure is a polar group-containing olefin copolymer having, as the structural unit (B), an enone structure, which is an unsaturated bond structure constituting a conjugated system of an alkene and a ketone substituted with two aromatic groups, in the main chain of the polymer. Therefore, while having a structure similar to that of conventional polyolefin resins, it can be easily decomposed under specific conditions such as light irradiation.
An enone structure in which both ends of an unsaturated bond are substituted with aromatic groups (aromatic hydrocarbon groups or aromatic heterocyclic groups) has high reactivity to light including ultraviolet light, and therefore it is believed that the polar group-containing olefin copolymer of the present disclosure can cleave itself and reduce the molecular weight in response to irradiation with light including ultraviolet light.

The polar group-containing olefin copolymer of the present disclosure can be easily decomposed artificially or by natural actions because a specific enone structure introduced as a structural unit into the main chain is cleaved by itself in response to light including ultraviolet light, and therefore the copolymer can be used as a decomposable resin.
The polar group-containing olefin copolymer of the present disclosure is itself an easily decomposable resin material and a photodecomposable resin material. Furthermore, the polar group-containing olefin copolymer of the present disclosure can also function as a decomposability imparting agent or a disintegrating agent that imparts decomposability to a resin composition mixed with other materials by decomposing itself.
The polar group-containing olefin copolymer of the present disclosure is expected to be a promising functional material, mainly in the recycling field. In addition, since the polar group-containing olefin copolymer of the present disclosure is expected to be decomposed by ultraviolet light in natural sunlight, it is expected to be one of the measures to address environmental plastic problems and marine plastic problems.

(1) Structural unit (A)
The structural unit (A) is a structural unit derived from one or more monomers (A) selected from the group consisting of ethylene and olefins having 3 to 20 carbon atoms.
The monomer (A) used in the present disclosure is at least one selected from the group consisting of ethylene and olefins having 3 to 20 carbon atoms. The olefins having 3 to 20 carbon atoms may be linear olefins or cyclic olefins, and examples thereof include at least one selected from the group consisting of α-olefins having 3 to 20 carbon atoms and cyclic olefins having 4 to 20 carbon atoms.
The α-olefin having 3 to 20 carbon atoms used in the present disclosure is an α-olefin having 3 to 20 carbon atoms represented by the structural formula CH ₂ ═CHR ¹⁸ (R ¹⁸ is a hydrocarbon group having 1 to 18 carbon atoms, which may have a linear structure or may be branched), and more preferably an α-olefin having 3 to 12 carbon atoms.
Examples of the cyclic olefin having 4 to 20 carbon atoms include cyclobutene, cyclopentene, cyclohexene, and norbornene.
Specific examples of the monomer (A) include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 3-methyl-1-butene, 4-methyl-1-pentene, and norbornene, etc. From the viewpoint of the production efficiency of the polymer, the monomer (A) is preferably at least one selected from the group consisting of ethylene, propylene, 1-butene, and norbornene, and more preferably ethylene.
The structural unit (A) may be of one type alone or of two or more types.

Examples of combinations of the two types include structural units derived from ethylene-propylene, ethylene-1-butene, ethylene-1-hexene, ethylene-1-octene, propylene-1-butene, propylene-1-hexene, propylene-1-octene, and ethylene-norbornene.
Examples of combinations of the three types include structural units derived from ethylene-propylene-1-butene, ethylene-propylene-1-hexene, ethylene-propylene-1-octene, propylene-1-butene-hexene, and propylene-1-butene-1-octene.

In the present disclosure, the monomer (A) used in the structural unit (A) preferably contains ethylene as an essential component and may further contain one or more α-olefins having 3 to 20 carbon atoms as necessary.
The amount of ethylene in the monomer (A) may be 65 to 100 mol % or 70 to 100 mol % relative to 100 mol % of the total amount of the monomer (A).

(2) Structural unit (B)
The structural unit (B) is a structural unit represented by the following general formula (I).

（一般式（Ｉ）中、Ｒ^ｘおよびＲ^ｙは、それぞれ独立して、酸素原子、硫黄原子、ハロゲン原子、及び窒素原子からなる群より選ばれる少なくとも１種を含む官能基及び脂肪族炭化水素基からなる群より選ばれる少なくとも１種の置換基で置換されていても良い、炭素数６～３０の芳香族炭化水素基または炭素数２～８の芳香族複素環基であり、Ｒ^ｘとＲ^ｙは－Ｏ－、－Ｓ－、－ＮＲ^ｚ（ここでＲ^ｚは水素原子、炭素数１～６のアシル基又は炭素数１～６の脂肪族炭化水素基）－、脂肪族炭化水素基、若しくはこれらの組み合わせを介して互いに結合して７～１０員環の環を形成していても良い。）

(In general formula (I), R ^x and R ^y each independently represent an aromatic hydrocarbon group having 6 to 30 carbon atoms or an aromatic heterocyclic group having 2 to 8 carbon atoms which may be substituted with at least one substituent selected from the group consisting of a functional group containing at least one selected from the group consisting of an oxygen atom, a sulfur atom, a halogen atom, and a nitrogen atom, and an aliphatic hydrocarbon group, and R ^x and R ^y may be bonded to each other via -O-, -S-, -NR ^z (wherein R ^z is a hydrogen atom, an acyl group having 1 to 6 carbon atoms, or an aliphatic hydrocarbon group having 1 to 6 carbon atoms)-, an aliphatic hydrocarbon group, or a combination thereof to form a 7-10-membered ring.)

In formula (I), the aromatic hydrocarbon group having 6 to 30 carbon atoms is preferably an aromatic hydrocarbon group having 6 to 16 carbon atoms, and more preferably an aromatic hydrocarbon group having 6 to 12 carbon atoms.
Specific examples of the aromatic hydrocarbon group include a phenyl group, a biphenyl group, a naphthyl group, an anthracenyl group, and a fluorenyl group.

In formula (I), the aromatic heterocyclic group having 2 to 8 carbon atoms is preferably an aromatic heterocyclic group having 2 to 6 carbon atoms, and more preferably an aromatic heterocyclic group having 2 to 5 carbon atoms.
Specific examples of the heterocyclic group include a pyridyl group, a furanyl group, a thienyl group, an oxazoyl group, a thiazolyl group, an imidazolyl group, and a pyrimidyl group.

In general formula (I), the aromatic hydrocarbon group or the aromatic heterocyclic group may be substituted with at least one substituent selected from the group consisting of a functional group containing at least one selected from the group consisting of an oxygen atom, a sulfur atom, a halogen atom, and a nitrogen atom, and an aliphatic hydrocarbon group.

In general formula (I), examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

Examples of functional groups containing at least one selected from the group consisting of oxygen atoms, sulfur atoms, and nitrogen atoms include hydroxyl groups, formyl groups, epoxy groups, ester groups having 1 to 30 carbon atoms, acyloxy groups having 1 to 30 carbon atoms, acyl groups having 1 to 30 carbon atoms, alkoxy groups having 1 to 30 carbon atoms, aryloxy groups having 6 to 30 carbon atoms, alkylthio groups having 1 to 30 carbon atoms, arylthio groups having 6 to 30 carbon atoms, cyano groups, nitro groups, amino groups which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, amide groups which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, sulfonyl groups having 1 to 30 carbon atoms, sulfoxide groups having 1 to 30 carbon atoms, and sulfonate ester groups having 1 to 30 carbon atoms.

The ester group having 1 to 30 carbon atoms is a monovalent group represented ^by -COORa, where R ^a represents a hydrocarbon group having 1 to 30 carbon atoms. The number of carbon atoms in the ester group does not include the number of carbon atoms in the carbonyl group and refers to the number of carbon atoms in R ^a , with the lower limit being 1 or more and optionally 2 or more, and the upper limit being 30 or less, and optionally 20 or less, or optionally 10 or less.
Examples of the hydrocarbon group having 1 to 30 carbon atoms for R ^a include linear, branched, and cyclic saturated or unsaturated aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and combinations thereof. Preferred examples of the alkyl group having 1 to 30 carbon atoms include, in addition to the examples of the alkyl group having 1 to 30 carbon atoms described below, alkenyl groups such as ethenyl, propenyl, butenyl, and pentenyl groups, aryl groups such as phenyl, methylphenyl, n-propylphenyl, i-propylphenyl, n-butylphenyl, i-butylphenyl, s-butylphenyl, t-butylphenyl, n-hexylphenyl, trimethylphenyl, pentamethylphenyl, biphenyl, naphthyl, anthracenyl, fluorenyl, and tolyl groups, and aralkyl groups such as benzyl, phenylethyl, phenylpropyl, naphthylmethyl, diphenylmethyl, and triphenylmethyl groups.
The alkyl group having 1 to 30 carbon atoms may be, for example, linear, branched, or cyclic, and includes, for example, a methyl group, an ethyl group, a 1-propyl group, a 1-butyl group, a 1-pentyl group, a 1-hexyl group, a 1-heptyl group, a 1-octyl group, a 1-nonyl group, a 1-decyl group, a t-butyl group, a tricyclohexylmethyl group, an isopropyl group, a 1-dimethylpropyl group, a 1,1,2-trimethylpropyl group, a 1,1-diethylpropyl group, an isobutyl group, a 1,1-dimethylbutyl group, a 2-pentyl group, Preferred examples of the aryl group include aryl, aryl and aryl groups, such as aryl, ...
The hydrocarbon group may further have a substituent, and examples of the substituent include a halogen atom, an epoxy group, an amino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, a hydroxyl group, etc. The number of carbon atoms contained in the substituent is not included in the above carbon number.
The hydrocarbon group for R ^a is preferably a hydrocarbon group having 1 to 8 carbon atoms, more preferably a hydrocarbon group having 1 to 6 carbon atoms, and even more preferably an unsubstituted hydrocarbon group having 1 to 6 carbon atoms.
Suitable specific examples of the ester group having 1 to 30 carbon atoms include a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an isopropoxycarbonyl group, an n-butoxycarbonyl group, a t-butoxycarbonyl group, a cyclohexyloxycarbonyl group, a 2-ethylhexyloxycarbonyl group, a benzyloxycarbonyl group, and a phenoxycarbonyl group.

The acyloxy group having 1 to 30 carbon atoms is a monovalent group represented by -OCOR ^b , where R ^b represents a hydrocarbon group having 1 to 30 carbon atoms. The number of carbon atoms in the acyloxy group does not include the number of carbon atoms in the carbonyl group, and refers to the number of carbon atoms in R ^b , with the lower limit being 1 or more and optionally 2 or more, and the upper limit being 30 or less, and optionally 20 or less, or optionally 10 or less.
Examples of the hydrocarbon group having 1 to 30 carbon atoms include the same as those mentioned above for R ^a .
Suitable specific examples of the acyloxy group having 1 to 30 carbon atoms include an acetyloxy group, a propionyloxy group, a (meth)acryloyloxy group, and a benzoyloxy group.

The acyl group having 1 to 30 carbon atoms is a monovalent group represented by ^-CORc , where ^Rc represents a hydrocarbon group having 1 to 30 carbon atoms. The number of carbon atoms in the acyl group does not include the number of carbon atoms in the carbonyl group, and refers to the number of carbon atoms in ^Rc , with the lower limit being 1 or more and optionally 2 or more, and the upper limit being 30 or less, and optionally 20 or less, or optionally 10 or less.
Examples of the hydrocarbon group having 1 to 30 carbon atoms for R ^c include the same as those for R ^a .
Suitable specific examples of the acyl group having 1 to 30 carbon atoms include an acetyl group, a propionyl group, a (meth)acryloyl group, and a benzoyl group.

The alkoxy group having 1 to 30 carbon atoms is a monovalent group represented by ^-ORd , where ^Rd represents an alkyl group having 1 to 30 carbon atoms or an aralkyl group having 7 to 30 carbon atoms. The number of carbon atoms in the alkoxy group may be 1 or more, or may be 2 or more, and may be 30 or less, or may be 20 or less, or may be 10 or less.
Examples of the alkyl group having 1 to 30 carbon atoms and the aralkyl group having 7 to 30 carbon atoms for ^Rd include the same as those for R ^a .
Suitable specific examples of the alkoxy group having 1 to 30 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, an i-butoxy group, an s-butoxy group, a t-butoxy group, an n-pentoxy group, an n-hexoxy group, a cyclopropoxy group, a cyclopentoxy group, a cyclohexyloxy group, an n-octoxy group, an n-deoxy group, and a benzyloxy group.
The aryloxy group having 6 to 30 carbon atoms is a monovalent group represented by -OR ^d' , where R ^d' represents an aryl group having 6 to 30 carbon atoms. The lower limit of the number of carbon atoms in the aryl group may be 6 or more, or may be 8 or more, and the upper limit may be 30 or less, or may be 20 or less, or may be 12 or less.
Examples of the aryl group having 6 to 30 carbon atoms for R ^d' include those corresponding to the aryl groups having 6 to 30 carbon atoms for the above-mentioned R ^a .
Specific examples of the aryloxy group having 6 to 30 carbon atoms include a phenoxy group, a methylphenoxy group, an ethylphenoxy group, a butylphenoxy group, a naphthyloxy group, a fluorenyloxy group, and an anthracenyloxy group.

The alkylthio group having 1 to 30 carbon atoms is a monovalent group represented by -SR ^e , where R ^e represents an alkyl group having 1 to 30 carbon atoms or an aralkyl group having 7 to 30 carbon atoms. The lower limit of the number of carbon atoms in the alkylthio group may be 1 or more, or may be 2 or more, and the upper limit may be 30 or less, or may be 20 or less, or may be 10 or less.
Examples of the alkyl group having 1 to 30 carbon atoms and the aralkyl group having 7 to 30 carbon atoms in R ^e include the same as those in R ^a .
Specific examples of the alkylthio group having 1 to 30 carbon atoms include a methylthio group, an ethylthio group, a benzylthio group, and the like.
An arylthio group having 6 to 30 carbon atoms is a monovalent group represented by -SR ^e' , where R ^e' represents an aryl group having 6 to 30 carbon atoms. The lower limit of the number of carbon atoms in the aryl group may be 6 or more, or may be 8 or more, and the upper limit may be 30 or less, or may be 20 or less, or may be 12 or less.
Examples of the aryl group having 6 to 30 carbon atoms in R ^e′ include those corresponding to the aryl groups having 6 to 30 carbon atoms among the above-mentioned R ^a .
Specific examples of the arylthio group having 6 to 30 carbon atoms include a phenylthio group and a naphthylthio group.

The amino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms is a monovalent group represented by -N( ^Rf ) ^Rg , where ^Rf and ^Rg each independently represent a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. The number of carbon atoms in the hydrocarbon group substituted with the substituted amino group may be 1 or more, or may be 2 or more, and may be 30 or less, or may be 20 or less, or may be 10 or less.
Examples of the hydrocarbon group having 1 to 30 carbon atoms in ^Rf and ^Rg include the same as those mentioned above ^{for Ra} .
Specific examples of the amino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms include, for example, an amino group (-NH ₂ ), a monomethylamino group, a dimethylamino group, a monoethylamino group, a diethylamino group, a monoisopropylamino group, a diisopropylamino group, a monophenylamino group, and a diphenylamino group.

The amide group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms is a monovalent group represented by -CONR ^h R ⁱ or -NR ^h COR ⁱ , where R ^h and R ⁱ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. The number of carbon atoms in the hydrocarbon group substituted with the substituted amide group does not include the number of carbon atoms in the carbonyl group, and refers to the number of carbon atoms in the R ^h and R ⁱ , with the lower limit being 1 or more and may be 2 or more, and the upper limit being 30 or less, may be 20 or less, or may be 10 or less.
Examples of the hydrocarbon group having 1 to 30 carbon atoms in ^Rh and ^Ri include the same as those mentioned above for ^Ra .
Specific examples of the amide group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms include, for example, -CONH ₂ , -CONH(CH ₃ ), -CON(CH ₃ ) ₂ , -CONH(C ₂ H ₅ ), -CON(C ₂ H ₅ ) ₂ , -CONH(i-C ₃ H ₇ ), -CON(i-C ₃ H ₇ ) ₂ , -CONH(Ph), -CON(Ph) ₂ , -NHCOCH ₃ , -NHCOC ₂ H ₅ , etc. In this specification, Ph represents a phenyl group.

The sulfonyl group having 1 to 30 carbon atoms is a monovalent group represented by -SO ₂ R ^j , where R ^j represents a hydrocarbon group having 1 to 30 carbon atoms. The lower limit of the number of carbon atoms in the sulfonyl group may be 1 or more, or may be 2 or more, and the upper limit may be 30 or less, or may be 20 or less, or may be 10 or less.
Examples of the hydrocarbon group having 1 to 30 carbon atoms for ^Rj include the same as those for R ^a .
Preferred specific examples of the _sulfonyl group having 1 to 30 carbon atoms include _-SO2CH3 and _-SO2Ph .

The sulfoxide group having 1 to 30 carbon atoms is a monovalent group represented by ^-SORk , where ^Rk represents a hydrocarbon group having 1 to 30 carbon atoms. The lower limit of the number of carbon atoms in the sulfoxide group may be 1 or more, or may be 2 or more, and the upper limit may be 30 or less, or may be 20 or less, or may be 10 or less.
Examples of the hydrocarbon group having 1 to 30 carbon atoms for R ^k include the same as those for R ^a .
Specific examples of the sulfoxide group having 1 to 30 carbon atoms preferably include -SOCH ₃ and -SOPh.

The sulfonate group having 1 to 30 carbon atoms is a monovalent group represented ^by _-OSO2R1 , where ^R1 represents a hydrocarbon group having 1 to 30 carbon atoms. The lower limit of the number of carbon atoms in the sulfonate group may be 1 or more, or may be 2 or more, and the upper limit may be 30 or less, or may be 20 or less, or may be 10 or less.
Examples of the hydrocarbon group having 1 to 30 carbon atoms in ^Rl include the same as those in R ^a .
Specific examples of the sulfonate group having 1 to 30 carbon atoms include, for example, --SO ₃ CH ₃ and --SO ₃ Ph.

Examples of the aliphatic hydrocarbon group which may be substituted with the aromatic hydrocarbon group or the aromatic heterocyclic group include linear, branched and cyclic saturated or unsaturated aliphatic hydrocarbon groups, and combinations thereof. Examples of the aliphatic hydrocarbon group include methyl, ethyl, 1-propyl, 1-butyl, 1-pentyl, 1-hexyl, 1-heptyl, 1-octyl, 1-nonyl, 1-decyl, t-butyl, tricyclohexylmethyl, isopropyl, 1-dimethylpropyl, 1,1,2-trimethylpropyl, 1,1-diethylpropyl, isobutyl, 1,1-dimethylbutyl, 2-pentyl, 3-pentyl, 2-hexyl, 3-hexyl, 2-ethyl ... and alkyl groups such as butylhexyl group, 2-heptyl group, 3-heptyl group, 4-heptyl group, 2-propylheptyl group, 2-octyl group, 3-nonyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, methylcyclopentyl group, cyclohexyl group, methylcyclohexyl group, cycloheptyl group, cyclooctyl group, cyclododecyl group, 1-adamantyl group, 2-adamantyl group, and norbornyl group; and alkenyl groups such as ethenyl group, propenyl group, butenyl group, and pentenyl group.
The aliphatic hydrocarbon group is preferably an aliphatic hydrocarbon group having 1 to 8 carbon atoms, and more preferably an aliphatic hydrocarbon group having 1 to 6 carbon atoms.
The aliphatic hydrocarbon group may be further substituted with an aromatic hydrocarbon group or an aralkyl group.
The aliphatic hydrocarbon group may further have a substituent, and examples of the substituent include a halogen atom, an epoxy group, an amino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, a hydroxyl group, etc. The number of carbon atoms contained in the substituent is not included in the above carbon number.

In general formula (I), R ^x and R ^y are aromatic hydrocarbon groups or aromatic heterocyclic groups which may be substituted as described above, and may further be bonded to each other via -O-, -S-, -NR ^z (wherein R ^z is a hydrogen atom, an acyl group having 1 to 6 carbon atoms, or an aliphatic hydrocarbon group having 1 to 6 carbon atoms)-, an aliphatic hydrocarbon group, or a combination thereof to form a 7- to 10-membered ring.
Examples of the aliphatic hydrocarbon group having 1 to 6 carbon atoms as ^Rz include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, etc. Examples of the acyl group having 1 to 6 carbon atoms as ^Rz include an acetyl group, a propionyl group, a butanoyl group, a pentanoyl group, a hexanoyl group, etc.
The aliphatic hydrocarbon group as the linking group may be a divalent alkylene group, such as an alkylene group having 1 to 4 carbon atoms, preferably an alkylene group having 1 or 2 carbon atoms.

As the at least one substituent selected from the group consisting of functional groups containing at least one selected from the group consisting of oxygen atoms, sulfur atoms, halogen atoms, and nitrogen atoms, and aliphatic hydrocarbon groups, from the viewpoint of the production efficiency of the copolymer, it is preferable to use at least one selected from the group consisting of hydroxyl groups, halogen atoms, alkoxy groups having 1 to 30 carbon atoms, aryloxy groups having 6 to 30 carbon atoms, amino groups which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, alkylthio groups having 1 to 30 carbon atoms, arylthio groups having 6 to 30 carbon atoms, and aliphatic hydrocarbon groups, and it is more preferable to use at least one selected from the group consisting of halogen atoms, alkoxy groups having 1 to 30 carbon atoms, aryloxy groups having 6 to 30 carbon atoms, and amino groups which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms.

As the substituents of R ^x and R ^y , it is preferable to select an electron-withdrawing substituent that has the effect of lowering the LUMO of the enone moiety, from the viewpoint of photodecomposition property including ultraviolet light, when it is desired to enhance photodecomposition property including ultraviolet light. The electron-withdrawing substituent referred to here is a substituent whose Hammett constant in Hammett's rule is a positive value equal to or greater than that of a hydrogen atom. The Hammett constant is defined as the F value in Chem. Rev. 1991, 91, 165-195. Conversely, when it is desired to weaken photodecomposition property including ultraviolet light, it is preferable to select an electron-donating substituent that has the effect of raising the LUMO of the enone moiety.
Examples of the electron-withdrawing substituent are preferably at least one selected from the group consisting of a sulfonyl group having 1 to 30 carbon atoms, a sulfoxide group having 1 to 30 carbon atoms, a sulfonate group having 1 to 30 carbon atoms, a halogen atom, a cyano group, and a nitro group, and more preferably at least one selected from the group consisting of a sulfonyl group having 1 to 30 carbon atoms, a sulfonate group having 1 to 30 carbon atoms, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, and a nitro group.

The structural unit (B) represented by the general formula (I) is preferably derived from one or more monomers (B) selected from the group consisting of polar group-containing monomers represented by the following general formula (1) in terms of the efficiency of copolymer production, since the structural unit (B) can be introduced into the copolymer in a single polymerization reaction. The polar group-containing monomer represented by the general formula (1) is ring-opened during the polymerization reaction and incorporated into the main chain of the polymer to become the structural unit (B).

（一般式（Ｉ）中、Ｒ^ｘおよびＲ^ｙは、それぞれ独立して、酸素原子、硫黄原子、ハロゲン原子、及び窒素原子からなる群より選ばれる少なくとも１種を含む官能基及び脂肪族炭化水素基からなる群より選ばれる少なくとも１種の置換基で置換されていても良い、炭素数６～３０の芳香族炭化水素基または炭素数２～８の芳香族複素環基であり、Ｒ^ｘとＲ^ｙは－Ｏ－、－Ｓ－、－ＮＲ^ｚ（ここでＲ^ｚは水素原子、炭素数１～６のアシル基又は炭素数１～６の脂肪族炭化水素基）－、脂肪族炭化水素基、若しくはこれらの組み合わせを介して互いに結合して７～１０員環の環を形成していても良い。）

(In general formula (I), R ^x and R ^y each independently represent an aromatic hydrocarbon group having 6 to 30 carbon atoms or an aromatic heterocyclic group having 2 to 8 carbon atoms which may be substituted with at least one substituent selected from the group consisting of a functional group containing at least one selected from the group consisting of an oxygen atom, a sulfur atom, a halogen atom, and a nitrogen atom, and an aliphatic hydrocarbon group, and R ^x and R ^y may be bonded to each other via -O-, -S-, -NR ^z (wherein R ^z is a hydrogen atom, an acyl group having 1 to 6 carbon atoms, or an aliphatic hydrocarbon group having 1 to 6 carbon atoms)-, an aliphatic hydrocarbon group, or a combination thereof to form a 7-10-membered ring.)

^Rx and ^Ry in the general formula (1) are the same as ^Rx and ^Ry in the general formula (I) described above.
As the polar group-containing monomer represented by the general formula (1), for example, 2,3-diarylcyclopropen-1-one and 2,3-diheteroarylcyclopropen-1-one are preferably used.
Specific examples of the 2,3-diarylcyclopropen-1-one and 2,3-diheteroarylcyclopropen-1-one include compounds having the following structures.

Examples of the compound in which R ^x and R ^y in general formula (1) form a ring structure include compounds having the following structures.

The one or more monomers (B) selected from the group consisting of polar group-containing monomers represented by the general formula (1) can be produced by an appropriate combination of conventionally known production methods. For example, a production method involving the reaction of various alkynes with a dichlorocarbene precursor and water (J. Am. Chem. Soc. 1966, 88(3), 504-509), a production method involving the reaction of various cyclopropenone acetals with an electrophile to introduce a substituent (Tetrahedron 1992, 48(11), 2045-2057), a production method involving the isomerization of various cyclobutenediones with light (J. Am. Chem. Soc. 1976, 98(12), 3641-3644), a production method involving the closure of a three-membered ring by debromination from a 1,3-dibromo-2-propanone structure (J. Am. Chem. Soc. 1965, 87(6), 1326-1331), and the like can be used.
As the one or more monomers (B) selected from the group consisting of polar group-containing monomers represented by the general formula (1), commercially available products may be used.

(3) Structural unit (C)
The structural unit (C) is a structural unit derived from one or more monomers (C) selected from the group consisting of a polar group-containing monomer (c-1) represented by the following general formula (2) and a polar group-containing monomer (c-2) represented by the following general formula (3):

（一般式（２）中、Ｒ^１とＲ^２は、それぞれ独立して、水素原子、炭素数１～３０のエステル基、炭素数１～３０のアシルオキシ基、炭素数１～３０のアルコキシ基、炭素数６～３０のアリールオキシ基、シアノ基、炭素数１～３０の炭化水素基で置換されていても良いアミノ基、炭素数１～３０の炭化水素基で置換されていても良いアミド基、炭素数１～３０の炭化水素基で置換されていても良いイミノ基、炭素数１～３０のハロゲン置換炭化水素基、又は、酸素原子、硫黄原子、窒素原子及びリン原子からなる群より選ばれる少なくとも１種を含む官能基で置換されていても良い炭素数１～３０の炭化水素基であり、Ｒ^１とＲ^２の少なくとも１つは、酸素原子及び窒素原子の少なくとも１種を含む基である。）

(In the general formula (2), R ¹ and R ² are each independently a hydrogen atom, an ester group having 1 to 30 carbon atoms, an acyloxy group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, a cyano group, an amino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, an amide group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, an imino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, a halogen-substituted hydrocarbon group having 1 to 30 carbon atoms, or a hydrocarbon group having 1 to 30 carbon atoms which may be substituted with a functional group containing at least one selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom, and a phosphorus atom, and at least one of R ¹ and R ² is a group containing at least one of an oxygen atom and a nitrogen atom.)

（一般式（３）中、Ｒ^３～Ｒ^１０は、それぞれ独立して、水素原子、ハロゲン原子、又は、炭素数１～２０の炭化水素基である。ｎは０又は正の整数を示し、ｎが２以上の場合には、Ｒ^７～Ｒ^１０は、それぞれの繰り返し単位の中で、それぞれ同一でも異なっていてもよい。Ｒ^１１～Ｒ^１４は、それぞれ独立して、水素原子、炭素数１～３０のエステル基、炭素数１～３０のアシルオキシ基、炭素数１～３０のアルコキシ基、炭素数６～３０のアリールオキシ基、シアノ基、炭素数１～３０の炭化水素基で置換されていても良いアミノ基、炭素数１～３０の炭化水素基で置換されていても良いアミド基、炭素数１～３０の炭化水素基で置換されていても良いイミノ基、又は、酸素原子、硫黄原子、窒素原子及びリン原子からなる群より選ばれる少なくとも１種を含む官能基で置換されていても良い炭素数１～３０の炭化水素基であり、Ｒ^１１～Ｒ^１４の少なくとも１つは、酸素原子及び窒素原子の少なくとも１種を含む基である。Ｒ^１１及びＲ^１２、並びに、Ｒ^１３及びＲ^１４は、各々一体化して２価の有機基を形成してもよく、Ｒ^１１又はＲ^１２と、Ｒ^１３又はＲ^１４とは、互いに環を形成していてもよい。）

(In general formula (3), R ³ to R ¹⁰ are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms. n is 0 or a positive integer, and when n is 2 or more, R ⁷ to R ¹⁰ may be the same or different in each repeating unit. R ¹¹ to R ¹⁴ are each independently a hydrogen atom, an ester group having 1 to 30 carbon atoms, an acyloxy group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, a cyano group, an amino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, an amide group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, an imino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, ^or a hydrocarbon group having 1 to 30 carbon atoms which may be substituted with a functional group containing at least one selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom, and a phosphorus atom; and At least one ^of R ¹¹ and R ¹² and R 13 and R ¹⁴ may be bonded together to form a divalent organic group, ^and R ¹¹ or R ¹² and R ¹³ or R ¹⁴ may be bonded together to form a ring.

(3-1) Polar group-containing monomer (c-1)
In general formula (2), the ester group having 1 to 30 carbon atoms, the acyloxy group having 1 to 30 carbon atoms, the alkoxy group having 1 to 30 carbon atoms, the aryloxy group having 6 to 30 carbon atoms, the amino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, and the amide group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms may be the same as those explained in general formula (I).
In addition, in the general formula (2), of the hydrocarbon group having 1 to 30 carbon atoms which may be substituted with a functional group containing at least one selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom, and a phosphorus atom, the hydrocarbon group having 1 to 30 carbon atoms may be the same as that described for R ^a in the general formula (I) above, and the functional group containing at least one selected from the group consisting of an oxygen atom, a sulfur atom, and a nitrogen atom may be the same as that described for the general formula (I) above.

In general formula (2), the imino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms is a monovalent group represented ^by -N= ^CRmRn , where ^Rm and ^Rn each independently represent a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. The number of carbon atoms in the hydrocarbon group substituted with the substituted imino group may be 1 or more, or may be 2 or more, and may be 30 or less, or may be 20 or less, or may be 10 or less.
Examples of the hydrocarbon group having 1 to 30 carbon atoms in R ^m and R ⁿ include the same as those mentioned above for R ^a .
Suitable specific examples of the imino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms include -N=CH(CH ₃ ) and -N=CHC ₂ H ₅ .

In general formula (2), the halogen-substituted hydrocarbon group having 1 to 30 carbon atoms is a hydrocarbon group having 1 to 30 carbon atoms in which at least one hydrogen atom has been substituted with a halogen atom. Examples of the hydrocarbon group having 1 to 30 carbon atoms include those similar to those of R ^a , among which alkyl groups and aryl groups are preferred from the viewpoint of ease of availability. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
The lower limit of the number of carbon atoms in the halogen-substituted hydrocarbon group having 1 to 30 carbon atoms may be 1 or more, or may be 2 or more, and the upper limit may be 30 or less, or may be 20 or less, or may be 10 or less.
Specific examples of the halogen-substituted hydrocarbon group having 1 to 30 carbon atoms include a halomethyl group in which 1 to 3 hydrogen atoms of a methyl group are substituted with halogen atoms, a chloroethyl group, a γ-chloropropyl group, a 3,3′,3″-trifluoropropyl group, a perfluoropropyl group, a perfluorophenyl group, a bromophenyl group, a chlorophenyl group, a fluorophenyl group, a dichlorophenyl group, and the like. Examples of the halomethyl group include a chloromethyl group, a bromomethyl group, a fluoromethyl group, a dichloromethyl group, a trifluoromethyl group, and the like.

In the general formula (2), in the hydrocarbon group having 1 to 30 carbon atoms which may be substituted with a functional group containing a phosphorus atom, examples of the hydrocarbon group having 1 to 30 carbon atoms include the same as those described above for R ^a .
Examples of functional groups containing a phosphorus atom include phosphite groups having 1 to 30 carbon atoms, phosphate groups having 1 to 30 carbon atoms, and phosphorus ylide groups having 1 to 30 carbon atoms.

The phosphite group having 1 to 30 carbon atoms is a monovalent group represented by -P(OR ^o ) ₂ , where each R ^o independently represents a hydrocarbon group having 1 to 30 carbon atoms. The number of carbon atoms in the phosphite group may be 1 or more, or may be 2 or more, and may be 30 or less, or may be 20 or less, or may be 10 or less.
Examples of the hydrocarbon group having 1 to 30 carbon atoms for R ^o include the same as those for R ^a .
Specific examples of the phosphite group having 1 to 30 carbon atoms include, for example, -P(OPh) ₂ and -P(OCH ₃ ) ₂ .

The phosphate group having 1 to 30 carbon atoms is a monovalent group represented by -P(=O)(OR ^p ) ₂ , where each R ^p is independently a hydrocarbon group having 1 to 30 carbon atoms. The lower limit of the number of carbon atoms in the phosphate group may be 1 or more, or may be 2 or more, and the upper limit may be 30 or less, or may be 20 or less, or may be 10 or less.
Examples of the hydrocarbon group having 1 to 30 carbon atoms for R ^p include the same as those for R ^a .
Specific examples of suitable phosphate groups having 1 to 30 carbon atoms include -P(=O)(OPh) ₂ and -P(=O)(OCH ₃ ) ₂ .

The phosphorus ylide group ^having 1 to 30 carbon atoms is a monovalent group represented by -P= ^CRqRr , where ^Rq and ^Rr each independently represent a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, and at least one of them is the hydrocarbon group. The number of carbon atoms in the hydrocarbon group substituted with the phosphorus ylide group does not include the carbon number of P=C, and refers to the number of carbon atoms in ^Rq or ^Rr , with the lower limit being 1 or more and may be 2 or more, and the upper limit being 30 or less, may be 20 or less, or may be 10 or less.
Examples of the hydrocarbon group having 1 to 30 carbon atoms in ^Rq and ^Rr include the same as those mentioned above ^{for Ra} .
Specific examples of the phosphorus ylide group having 1 to 30 carbon atoms include, for example, -P=CHCH ₃ , -P=CHPh, -P=CHCH ₂ Ph, and the like.

At least one of R ¹ and R ² is a group containing at least one of an oxygen atom and a nitrogen atom. Examples of the group containing at least one of an oxygen atom and a nitrogen atom include an ester group having 1 to 30 carbon atoms, an acyloxy group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, a cyano group, an amino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, an amide group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, an imino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, and a hydrocarbon group having 1 to 30 carbon atoms substituted with a substituent containing at least one of an oxygen atom and a nitrogen atom. Examples of the substituent containing at least one of an oxygen atom and a nitrogen atom of the hydrocarbon group having 1 to 30 carbon atoms include a hydroxyl group, an epoxy group, an ester group having 1 to 30 carbon atoms, an acyloxy group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, a cyano group, an amino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, an amide group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, an imino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, a thioester group having 1 to 30 carbon atoms, a sulfonyl group having 1 to 30 carbon atoms, a sulfoxide group having 1 to 30 carbon atoms, a sulfonate ester group having 1 to 30 carbon atoms, a phosphite group having 1 to 30 carbon atoms, and a phosphate group having 1 to 30 carbon atoms.

As the polar group-containing monomer (c-1) represented by the general formula (2), for example, a (meth)acrylic acid ester is preferably used.
Specific examples of the (meth)acrylic acid ester include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, phenyl (meth)acrylate, toluyl (meth)acrylate, benzyl (meth)acrylate, hydroxyethyl (meth)acrylate, (meth)acrylic acid, Examples of the acrylates include hydroxybutyl (meth)acrylate, 1,4-cyclohexanedimethanol mono(meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, (meth)acrylic acid polyethylene glycol ester, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, 2-aminoethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, glycidyl (meth)acrylate, trifluoromethyl (meth)acrylate, 2-trifluoromethylethyl (meth)acrylate, perfluoroethyl (meth)acrylate, and 4-(1,2,2,6,6-pentamethylpiperidyl)acrylate.
Examples of the polar group-containing monomer (c-1) represented by the general formula (2) include (meth)acrylamide, (meth)acrylonitrile, vinylamide, vinyl acetate, allyl acetate, 3-butenyl acetate, 3-cyanopropene, methyl vinyl ether, 3-chloropropene, N-propylideneethenamine, 3-(methylthio)-1-propene, 3-(methylsulfinyl)-1-propene, 3-(methylsulfonyl)-1-propene, 2-propene-1-methyl sulfonate, and 2-propenyl dimethyl phosphonate.

In the general formula (2), it is preferable that R ¹ is a hydrogen atom in terms of the production efficiency of the polymer, the molecular weight of the polymer, and copolymerizability with the monomer (A) and the monomer (B).
In addition, in the general formula (2), it is preferable that R ¹ is a hydrogen atom and R ² is an ester group having 1 to 30 carbon atoms, a cyano group, a cyanomethyl group, a cyanoethyl group, a halomethyl group, an acyloxymethyl group, or an acyloxyethyl group, from the viewpoints of the production efficiency of the polymer, the molecular weight of the polymer, and copolymerizability with the monomer (A) and the monomer (B).

As the polar group-containing monomer (c-1) represented by the general formula (2), it is preferable to use at least one selected from the group consisting of methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, vinyl acetate, allyl acetate, 3-butenyl acetate, acrylonitrile, and 3-cyanopropene, in terms of the high weight ratio of heteroatoms, the small side effects on late transition metal catalysts, the polymer production efficiency, the molecular weight of the polymer, and the copolymerizability with the monomers (A) and (B).

(3-2) Polar group-containing monomer (c-2)
In the general formula (3), examples of the halogen atom in R ³ to R ¹⁰ include a fluorine atom, a chlorine atom and a bromine atom.
Examples of the hydrocarbon groups having 1 to 20 carbon atoms in R ³ to R ¹⁰ include the same hydrocarbon groups having 1 to 20 carbon atoms as those of R ^a in general formula (I), including alkyl groups such as methyl, ethyl, and propyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; and alkenyl groups such as vinyl, allyl, and propenyl groups.
n represents 0 or a positive integer, and is preferably 2 or less, and more preferably 1 or less.

In general formula (3), the ester group having 1 to 30 carbon atoms, the acyloxy group ^having 1 to 30 carbon atoms, the alkoxy group having 1 to 30 carbon atoms, the amino group which may be substituted with ^a hydrocarbon group having 1 to 30 carbon atoms, the amide group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, the imino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, or the hydrocarbon group having 1 to 30 carbon atoms which may be substituted with a functional group containing at least one selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom, and a phosphorus atom, in R 11 to R 14, may be the same as those explained for R ¹ and R ² in general formula (2).

In general formula (3), at least one of R ¹¹ to R ¹⁴ is a group containing at least one of an oxygen atom and a nitrogen atom, and the group containing at least one of an oxygen atom and a nitrogen atom may be the same as that described for R ¹ and R ² in general formula (2).

R ¹¹ and R ¹² , and R ¹³ and R ¹⁴ may each be combined together to form a divalent organic group. Here, the organic group refers to a group containing at least a carbon atom. When they are combined together to form a divalent organic group, it is preferably a divalent hydrocarbon group, and the hydrocarbon group may contain a linking group such as -CO-, -O(CO)-, -COO-, -C(=O)OC(=O)-, -C(=O)NR ^f C(=O)-, -SO ₂ -, -O-, etc. Here, R ^f is the same as above.

R ¹¹ or R ¹² and R ¹³ or R ¹⁴ may be bonded to each other to form a ring, or may form a carbocyclic or heterocyclic ring, which may be a monocyclic or polycyclic ring. For example, R ¹¹ or R ¹² and R ¹³ or R ¹⁴ may be bonded to each other to form a -CO-O-CO- group.

In the general formula (3), it is preferable that n is 0 or 1 and R ³ to R ¹⁰ are hydrogen atoms or methyl groups from the viewpoint of ease of synthesis of the polar monomer itself.

Among the polar group-containing monomers (c-2) represented by the general formula (3), in terms of small side effects on late transition metal catalysts, polymer production efficiency, polymer molecular weight, and copolymerizability with the monomers (A) and (B), the following are particularly preferred: methyl 5-norbornene-2-carboxylate, ethyl 5-norbornene-2-carboxylate, propyl 5-norbornene-2-carboxylate, butyl 5-norbornene-2-carboxylate, dimethyl 5-norbornene-2,3-dicarboxylate, dimethyl 5-norbornene-2,3-dicarboxylic acid anhydride, 2-hydroxy-5-norbornene, 5-norbornene-2-methanol, 5-norbornene-2-methylamine, 2-acetoxy-5-norbornene, It is preferably at least one selected from the group consisting of 2-cyanomethyl-5-norbornene and 5-norbornene-2-carbonitrile, and more preferably at least one selected from the group consisting of methyl 5-norbornene-2-carboxylate, ethyl 5-norbornene-2-carboxylate, propyl 5-norbornene-2-carboxylate, butyl 5-norbornene-2-carboxylate, 5-norbornene-2,3-dicarboxylic anhydride, and 5-norbornene-2-methanol.

(4) Other structural units The polar group-containing olefin copolymer of the present disclosure may further contain other structural units different from the structural units (A), (B) and (C). Examples of the other structural units include a structural unit represented by the following formula (II). The structural unit represented by the following formula (II) may be a structural unit derived from one or more monomers (B) selected from the group consisting of polar group-containing monomers represented by the general formula (1).

(5) Polar Group-Containing Olefin Copolymer The polar group-containing olefin copolymer of the present disclosure contains a structural unit (A) derived from one or more monomers selected from the group consisting of ethylene and olefins having 3 to 20 carbon atoms, and a structural unit (B) represented by the general formula (I) above.
The polar group-containing olefin copolymer of the present disclosure must contain at least one type of structural unit (A) and at least one type of structural unit (B), and must contain structural units derived from a total of two or more types of monomers.

In the present disclosure, the proportion of the structural unit (A) in the polar group-containing olefin copolymer may be appropriately selected according to the desired physical properties, but the lower limit is usually 60.00 mol% or more, preferably 65.50 mol% or more, more preferably 76.00 mol% or more, even more preferably 85.00 mol% or more, and particularly preferably 87.00 mol% or more, based on 100 mol% of all structural units. On the other hand, the upper limit is usually 99.98 mol% or less, preferably 99.92 mol% or less, more preferably 99.90 mol% or less, even more preferably 99.80 mol% or less, and particularly preferably 99.70 mol% or less.

The proportion of the structural unit (B) in the polar group-containing olefin copolymer may be appropriately selected depending on the average molecular weight and the desired physical properties, but the lower limit is usually 0.01 mol% or more, preferably 0.05 mol% or more, more preferably 0.10 mol% or more, and even more preferably 0.20 mol% or more, based on 100 mol% of all structural units. On the other hand, the upper limit is usually 15.00 mol% or less, preferably 10.00 mol% or less, more preferably 8.00 mol% or less, and even more preferably 6.00 mol% or less.

The polar group-containing olefin copolymer of the present disclosure may further contain one or more structural units (C) derived from one or more monomers selected from the group consisting of the polar group-containing monomer (c-1) and the polar group-containing monomer (c-2).
When the polar group-containing olefin copolymer of the present disclosure contains structural unit (C), the proportion of structural unit (C) in the polar group-containing olefin copolymer may be appropriately selected according to desired physical properties, but the lower limit is usually 0.01 mol% or more, preferably 0.05 mol% or more, more preferably 0.10 mol% or more, and even more preferably 0.50 mol% or more, based on 100 mol% of all structural units.On the other hand, the upper limit is usually 35.00 mol% or less, preferably 30.00 mol% or less, more preferably 20.00 mol% or less, and even more preferably 10.00 mol% or less.

The polar group-containing olefin copolymer of the present disclosure may further contain a structural unit represented by formula (II) above.
When the polar group-containing olefin copolymer of the present disclosure contains the structural unit represented by the formula (II), the proportion of the structural unit in the polar group-containing olefin copolymer may be appropriately selected according to the desired physical properties, and the lower limit is usually 0.001 mol% or more, may be 0.005 mol% or more, or may be 0.01 mol% or more, based on 100 mol% of the total structural units.On the other hand, the upper limit is usually 15.00 mol% or less, preferably 10.00 mol% or less, more preferably 3.00 mol% or less, and even more preferably 2.00 mol% or less.
The proportion of the structural unit (B) relative to the total of the structural unit (B) and the structural unit represented by formula (II) (100 mol %) is usually 50 mol % or more, preferably 55 mol % or more, and even more preferably 60 mol % or more.
It is preferred that the proportion of the structural unit (B) in the polar group-containing olefin copolymer is greater than the proportion of the structural unit represented by the formula (II) above, in view of expanding the applications of the polar group-containing olefin copolymer.

A structure derived from one molecule of each monomer is defined as one structural unit in the polar group-containing olefin copolymer.
The amount of structural units is the ratio of each structural unit expressed in mol % when the total amount of structural units in the polar group-containing olefin copolymer is taken as 100 mol %.

The polar group-containing olefin copolymer of the present disclosure may be a random copolymer, block copolymer, graft copolymer, etc., of structural unit (A), structural unit (B), and optionally contained structural unit (C). Among these, a random copolymer that may contain a large amount of structural unit (B) may be used.

In addition, in the polar group-containing olefin copolymer of the present disclosure, it is preferable that the molar fraction [A] of the structural unit (A), the molar fraction [B] of the structural unit (B), and the molar fraction [C] of the structural unit (C) which may be further included satisfy [A] ≧ {([A] + [B] + [C]) × 80%} in order for the copolymer to maintain the properties of an olefin, such as hydrophobicity.

The amount of structural units can be controlled by the selection of catalyst, the amounts of monomer (A), monomer (B) and monomer (C) added during polymerization, and the pressure and temperature during polymerization. Specific means for increasing the amount of structural units derived from monomer (B) and monomer (C) in the copolymer include increasing the amounts of monomer (B) and monomer (C) added during polymerization, reducing the olefin pressure during polymerization, and increasing the polymerization temperature. For example, it is necessary to adjust these factors to control the copolymer to the desired region.

The amount of structural units in the polar group-containing olefin copolymer in the present disclosure is determined using ¹ H-NMR spectrum and ¹³ C-NMR spectrum. The NMR spectrum is measured by the following method.
The polar group-containing olefin copolymer is dissolved in 1,1,2,2-tetrachloroethane-d2 under heating to obtain a homogeneous solution, which is then subjected to NMR measurement. ¹ H-NMR spectrum is measured for a 5% by mass solution of the polar group-containing olefin copolymer, and ¹³ C-NMR spectrum is measured for a 15% by mass solution of the polar group-containing olefin copolymer.
Alternatively, about 150 mg of the polar group-containing olefin copolymer may be dissolved by heating in 2.4 mL of a mixed solvent of 1,2-dichlorobenzene:bromobenzene-d5=1:2, and the resulting homogeneous solution may be subjected to NMR measurement.
The NMR measurement is carried out at 120° C. using, for example, Ascend 500 manufactured by BRUKER Co., Ltd. or AVANCE 400 manufactured by BRUKER Co., Ltd.
¹³ C-NMR is performed using chromium (III) acetylacetonate as a relaxation reagent and using an inverse gated decoupling method (9.0 microsecond 90° pulse, spectrum width: 31 kHz, relaxation time: 10 seconds, acquisition time: 10 seconds, FID accumulation number 5,000 to 10,000), and quantitative analysis is performed. Alternatively, ¹³ C-NMR may be performed using an inverse gated decoupling method (15.8 microsecond 90° pulse, spectrum width: 25 kHz, relaxation time: 50 seconds, acquisition time: 1.5 seconds, FID accumulation number 1,024), and quantitative analysis may be performed.

The weight average molecular weight (Mw) of the polar group-containing olefin copolymer in this disclosure is usually in the range of 1,000 to 2,000,000, preferably 10,000 to 1,500,000, more preferably 20,000 to 1,000,000, more preferably 31,000 to 800,000, and even more preferably 35,000 to 800,000. If the Mw is less than 1,000, physical properties such as mechanical strength and impact resistance may be insufficient, and if the Mw exceeds 2,000,000, the melt viscosity may become very high, making molding difficult.

The number average molecular weight (Mn) of the polar group-containing olefin copolymer in this disclosure is usually in the range of 1,000 to 2,000,000, preferably 3,000 to 1,500,000, more preferably 4,000 to 1,000,000, more preferably 5,000 to 800,000, and even more preferably 5,000 to 600,000. If Mn is less than 1,000, physical properties such as mechanical strength and impact resistance may be insufficient, and if Mn exceeds 2 million, the melt viscosity may become very high, making molding difficult.

The ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the polar group-containing olefin copolymer in the present disclosure is usually in the range of 1.0 to 4.0, preferably 1.3 to 3.5, and more preferably 1.4 to 3.3. If Mw/Mn is less than 1.0, various processabilities including molding may be insufficient, and if it exceeds 4.0, mechanical properties may be poor.
In the present disclosure, (Mw/Mn) may be expressed as the molecular weight distribution parameter.

The weight average molecular weight (Mw) and number average molecular weight (Mn) in this disclosure are determined by gel permeation chromatography (GPC).
An example of a GPC measurement method in this disclosure is as follows.
The number average molecular weight and the weight average molecular weight are calculated by size exclusion chromatography (solvent: 1,2-dichlorobenzene, temperature: 145 ° C.) using a high-temperature GPC apparatus manufactured by Tosoh Corporation, HLC-8321GPC / HT equipped with a TSKgel GMHHR-H (S) HT column (two columns of 7.8 mm I.D. × 30 cm in series) manufactured by Tosoh Corporation, using polystyrene as a molecular weight standard substance, or by size exclusion chromatography (solvent: 1,2-dichlorobenzene, temperature: 140 ° C.) using a high-temperature GPC apparatus manufactured by Waters Corporation, ALC / GPC 150C equipped with an AT-806MS column (three columns of 8.0 mm I.D. × 25 cm in series) manufactured by Showa Denko K.K., using polystyrene as a molecular weight standard substance.

The melting point (Tm, ° C.) of the polar group-containing olefin copolymer in the present disclosure observed by differential scanning calorimetry (DSC) is not particularly limited. The melting point is preferably more than 50 ° C. and not more than 140 ° C., more preferably 60 ° C. to 138 ° C., and even more preferably 70 ° C. to 135 ° C. If this range is satisfied, the heat resistance, impact resistance, adhesiveness, etc. will be excellent.
The melting point can be determined, for example, using an "EXSTAR6000" manufactured by Seiko Electronics Co., Ltd., by measuring at an isothermal temperature of 40°C for 1 minute, heating from 40°C to 160°C at a rate of 10°C/min, isothermal temperature at 160°C for 10 minutes, cooling from 160°C to 10°C at a rate of 10°C/min, isothermal temperature at 10°C for 5 minutes, and then heating from 10°C to 160°C at a rate of 10°C/min.

The polar group-containing olefin copolymer of the present disclosure has the specific enone structure as the structural unit (B) in the polymer main chain, and therefore has a structure similar to that of conventional polyolefin resins, and is easily decomposable under specific conditions such as light irradiation. Here, the term "easily decomposable" refers to the property of being easily decomposed under specific conditions such as light irradiation, compared to conventional polyolefin resins consisting of the structural unit (A).
In the polar group-containing olefin copolymer of the present disclosure, for example, in at least one of the following ultraviolet ray (UV) irradiation experiment procedure 1 and ultraviolet ray (UV) irradiation experiment procedure 2, the number average molecular weight (Mn) after the ultraviolet ray (UV) irradiation experiment relative to the number average molecular weight (Mn) before the ultraviolet ray (UV) irradiation experiment (Mn after irradiation/Mn before irradiation) is preferably 0.7 or less, more preferably 0.5 or less.
Furthermore, in at least one of the following ultraviolet (UV) irradiation experiment procedures, for example, ultraviolet (UV) irradiation experiment procedure 1 and ultraviolet (UV) irradiation experiment procedure 2, the polar group-containing olefin copolymer in the present disclosure preferably has a ratio (Mw/Mn) after ultraviolet (UV) irradiation experiment to the ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) before ultraviolet (UV) irradiation experiment of 1.3 or more, and more preferably 1.4 or more.

[Ultraviolet (UV) irradiation experiment procedure 1]
A 100 mg polymer sample is placed in a 3.5 mL vial (body made of colorless glass, cap made of white polypropylene). The sample holder is made of aluminum. The distance between the backing (aluminum sample holder) and the sample is 5 mm (equal to the radius of the glass vial).
A xenon weather meter (e.g., Super Xenon Weather Meter SX75 manufactured by Suga Test Instruments Co., Ltd.) is used for ultraviolet irradiation, and a xenon lamp is used as the light source. The inner filter is quartz, and the outer filter is #295. The irradiance is 60 W/ ^m2 . The test conditions conform to the industry standard (JIS K7350-2). The temperature is set to 65°C at the black standard temperature. The humidity outside the vial is set to 50%. There is no spray setting or dark time, and the irradiation time is 50 hours.
[Ultraviolet (UV) irradiation experiment procedure 2]
100 mg of each polymer sample is placed in a 3.5 mL vial (body made of colorless glass, cap made of white PP). The sample holder is made of aluminum. The distance between the backing (aluminum sample holder) and the sample is 5 mm (equal to the radius of the glass vial).
A xenon weather meter (e.g., Super Xenon Weather Meter Ci4000 manufactured by ATLAS) was used for ultraviolet irradiation, and a xenon lamp was used as the light source. The inner filter was made of borosilicate, and the outer filter was made of borosilicate. The irradiance was 60 W/ ^m2 . The test conditions were based on the industry standard (ISO16474), with the only change being that the black panel temperature was set to 65°C. The humidity setting outside the vial was set to 50%. There was no spray setting or dark time. The irradiation time was 100 hours.

(6) Method for Producing Polar Group-Containing Olefin Copolymer (6-1) Catalyst The polar group-containing olefin copolymer of the present disclosure may be polymerized in the presence of a catalyst containing a transition metal, from the viewpoint of ring-opening one or more monomers (B) selected from the group consisting of polar group-containing monomers represented by the general formula (1) in a one-step polymerization reaction and introducing them into the main chain of the polymer, and from the viewpoint of making the molecular structure of the copolymer linear.
The catalyst containing a transition metal is not particularly limited as long as it is capable of ring-opening one or more monomers (B) selected from the group consisting of polar group-containing monomers represented by the general formula (1) and polymerizing the monomers (A) with the monomers (B). For example, a transition metal compound of Groups 5 to 11 having a chelating ligand may be mentioned.
Specific examples of preferred transition metals include vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, iron, platinum, ruthenium, cobalt, rhodium, nickel, palladium, and copper. Among these, preferred are transition metals of Groups 8 to 11, more preferred are transition metals of Group 10, and examples of the transition metals of Group 10 include nickel, palladium, and platinum, and particularly preferred are nickel (Ni) and palladium (Pd). These metals may be used alone or in combination.
Chelating ligands have at least two atoms selected from the group consisting of P, N, O, and S, and include ligands that are bidentate or multidentate, and are electronically neutral or anionic. Exemplary structures are given in the review by Brookhart et al. (Chem. Rev., 2000, 100, 1169).
Preferred examples of bidentate anionic P,O ligands include phosphorus sulfonates, phosphorus carboxylates, phosphorus phenoxides, phosphorus alkoxides, and phosphorus enolates. Other examples of bidentate anionic N,O ligands include salicylaldiminates and pyridine carboxylates. Other examples of diimine ligands, diphenoxide ligands, and diamide ligands are also included.

The catalyst containing a transition metal is preferably a catalyst containing a late transition metal selected from the group consisting of Group 8 to Group 10 transition metals, from the viewpoints of polymer production efficiency, molecular weight of the polymer, and copolymerizability with the monomer (A) and the monomer (B), and among these, a catalyst containing a Group 10 transition metal is preferable, and further, a catalyst containing a Group 10 transition metal and having a chelating ligand containing one or more phosphorus atoms as a coordination point for the Group 10 transition metal is preferable.

As the catalyst containing the transition metal, in terms of the polymer production efficiency, the molecular weight of the polymer, and the copolymerizability with the monomer (A) and the monomer (B), it is preferable that the catalyst contains a Group 10 transition metal and is at least one selected from the group consisting of compounds represented by the following general formula (104):

（一般式（１０４）中、Ｍは第１０族遷移金属を示し、ＱはＡ［－Ｓ（＝Ｏ）_２－Ｏ－］Ｍ、Ａ［－Ｃ（＝Ｏ）－Ｏ－］Ｍ、Ａ［－Ｏ－］Ｍ、又はＡ［－Ｓ－］Ｍの「［ ］」の中に示される２価の基を示す（ただし、両側のＡ、Ｍは基の結合方向を示すために記載している）。Ａは、Ｑとリン原子を連結する炭素数１～３０の２価の炭化水素基で官能基を有していてもよく、Ｌは金属から脱離可能な０価の配位子を示し、Ｒ^１５とＲ^１６とＲ^１７は官能基を有していてもよい炭素数１～３０の炭化水素基を示す。Ｒ^１５とＬは環を形成してもよく、Ｒ^１６とＲ^１７は環を形成してもよく、Ｒ^１６又はＲ^１７はＡと結合して環を形成してもよい。）

(In general formula (104), M represents a Group 10 transition metal, Q represents a divalent group shown in "[ ]" of A[-S(=O) ₂ -O-]M, A[-C(=O)-O-]M, A[-O-]M, or A[-S-]M (wherein A and M on both sides are written to indicate the bonding direction of the group), A is a divalent hydrocarbon group having 1 to 30 carbon atoms connecting Q and the phosphorus atom and may have a functional group, L represents a zero-valent ligand removable from the metal, R ¹⁵ , R ¹⁶ , and R ¹⁷ represent a hydrocarbon group having 1 to 30 carbon atoms which may have a functional group. R ¹⁵ and L may form a ring, R ¹⁶ and R ¹⁷ may form a ring, or R ¹⁶ or R ¹⁷ may be bonded to A to form a ring.)

In the general formula (104), M represents a Group 10 transition metal, and among these, Ni and Pd are preferable.
Q represents a divalent group represented by -S(=O) ₂ -O-, -C(=O)-O-, -P(=O)(-OH)-O-, or -S-, and is a moiety that coordinates one electron to M. In each of the above formulas, the left side is bonded to A, and the right side is bonded to M. Among these, -S(=O) ₂ -O- is particularly preferred in terms of catalytic activity.

A is a divalent hydrocarbon group having 1 to 30 carbon atoms that links Q to the phosphorus atom, and the hydrocarbon group may have a functional group.
The divalent hydrocarbon group having 1 to 30 carbon atoms is preferably a divalent hydrocarbon group having 1 to 12 carbon atoms, and preferred examples include alkylene groups and arylene groups, with arylene groups being particularly preferred.

Examples of the functional group of the hydrocarbon group for A include a halogen atom, -OR ^α , -CO ₂ R ^α , -CO ₂ M', -CON(R ^β ) ₂ , -COR ^α , -SR ^α , -SO ₂ R ^α , -SOR ^α , -OSO ₂ R ^α , -PO(OR ^α ) _2-y (R ^β ) _y , -CN, -NHR ^α , -N(R ^α ) ₂ , -Si(OR ^β ) _3-x (R ^β ) _x , -OSi(OR ^β ) _3-x (R ^β ) _x , -NO ₂ , -SO ₃ M', -PO ₃ M' ₂ , -P(O)(OR ^α ) ₂ M', or an epoxy-containing group (wherein R ^β represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, R ^α represents a hydrocarbon group having 1 to 20 carbon atoms, M′ represents an alkali metal, an alkaline earth metal, ammonium, a quaternary ammonium or a phosphonium, x represents an integer of 0 to 3, and y represents an integer of 0 to 2).
Examples of the hydrocarbon group having 1 to 20 carbon atoms herein include the same hydrocarbon groups having 1 to 20 carbon atoms as those exemplified as R ^a in the general formula (I) above.

Examples of the divalent hydrocarbon group having 1 to 30 carbon atoms for A include the following formulas (a-1) to (a-7). In the following formulas, R ¹⁰⁴ is each independently a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or a functional group. Examples of the hydrocarbon group having 1 to 30 carbon atoms for R ¹⁰⁴ include the same as those for R ^a in general formula (I). Of the hydrocarbon groups having 1 to 30 carbon atoms, hydrocarbon groups having 1 to 20 carbon atoms are preferred, and hydrocarbon groups having 1 to 10 carbon atoms are more preferred.
As the divalent hydrocarbon group having 1 to 30 carbon atoms for A, the following formula (a-7) is particularly preferred in terms of catalytic activity.

L represents a zero-valent ligand which can be removed from the metal.
L is preferably a compound having an electron-donating group and capable of stabilizing the metal complex by coordinating to the metal atom M. L may be a hydrocarbon compound having 1 to 20 carbon atoms and having oxygen, nitrogen, or sulfur as an atom capable of coordinating, or a hydrocarbon compound having a carbon-carbon unsaturated bond capable of coordinating to a transition metal (which may contain a heteroatom). L preferably has 1 to 16 carbon atoms, more preferably 1 to 10 carbon atoms.

Preferred examples of L include pyridines, piperidines, alkyl ethers, aryl ethers, alkylaryl ethers, cyclic ethers, alkylnitrile derivatives, arylnitrile derivatives, alcohols, amides, aliphatic esters, aromatic esters, amines, and cyclic unsaturated hydrocarbons.
Examples of L having a sulfur atom include dimethyl sulfoxide (DMSO). Examples of L having a nitrogen atom include trialkylamines having an alkyl group with 1 to 10 carbon atoms, dialkylamines having an alkyl group with 1 to 10 carbon atoms, pyridine, 2,6-dimethylpyridine (also known as 2,6-lutidine), aniline, 2,6-dimethylaniline, 2,6-diisopropylaniline, N,N,N',N'-tetramethylethylenediamine (TMEDA), 4-(N,N-dimethylamino)pyridine (DMAP), acetonitrile, benzonitrile, quinoline, and 2-methylquinoline. Examples of L having an oxygen atom include diethyl ether, tetrahydrofuran, and 1,2-dimethoxyethane. From the viewpoints of the stability and catalytic activity of the complex, dimethyl sulfoxide (DMSO), pyridine, 2,6-dimethylpyridine (also known as 2,6-lutidine), and N,N,N',N'-tetramethylethylenediamine (TMEDA) are preferred, and dimethyl sulfoxide (DMSO) and 2,6-dimethylpyridine (also known as 2,6-lutidine) are more preferred.
R ¹⁵ and L may form a ring. An example of such a ring is a cyclooct-1-enyl group, which is also a preferred embodiment of the present disclosure.

R ¹⁵ , R ¹⁶ and R ¹⁷ each represent a hydrocarbon group having 1 to 30 carbon atoms which may have a functional group.
Examples of the hydrocarbon group having 1 to 30 carbon atoms in R ¹⁵ , R ¹⁶ and R ¹⁷ include the same as those for R ^a in the general formula (I).
The functional groups in R ¹⁵ , R ¹⁶ and R ¹⁷ may be the same as the functional group in A.

R ¹⁵ is preferably a hydrocarbon group having 1 to 20 carbon atoms, a halogen-substituted hydrocarbon group having 1 to 20 carbon atoms, or a hydrocarbon group having 1 to 20 carbon atoms substituted with an alkoxy group or an aryloxy group, and the number of carbon atoms in the hydrocarbon group is more preferably 1 to 10. Specifically, R ¹⁵ is more preferably an alkyl group having 1 to 3 carbon atoms, a benzyl group, a trifluoromethyl group, a pentafluorophenyl group, a 1-(methoxymethyl)ethyl group, a 1-(ethoxymethyl)ethyl group, a 1-(phenoxymethyl)ethyl group, or a 1-(2,6-dimethylphenoxymethyl)ethyl group, and even more preferably a methyl group or a benzyl group.

R ¹⁶ and R ¹⁷ are in the vicinity of the transition metal M and exert steric and/or electronic interactions with the transition metal M. In order to exert such effects, it is preferable that R ¹⁶ and R ¹⁷ are bulky. The number of carbon atoms of R ¹⁶ and R ¹⁷ is preferably 3 to 30, and more preferably 6 to 20.

Each of R ¹⁶ and R ¹⁷ is preferably an alkyl group having 3 to 10 carbon atoms which may have a functional group, a cycloalkyl group having 6 to 20 carbon atoms which may have a functional group, or an aryl group having 6 to 20 carbon atoms which may have a functional group.
The alkyl group having 3 to 10 carbon atoms for R ¹⁶ and R ¹⁷ is preferably an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, or a t-butyl group.

Examples of the cycloalkyl group having 6 to 20 carbon atoms for R ¹⁶ and R ¹⁷ which may have a functional group include a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, etc. which may have a functional group and which may be substituted with a linear or branched alkyl group having 3 to 10 carbon atoms.
In addition, for example, it may be a cycloalkyl group described in paragraphs 0104 to 0113 of JP 2018-141138 A (X in paragraphs 0104 to 0113 of JP 2018-141138 A indicates the bonding position of P (phosphorus atom) in general formula (104) of the present disclosure).
In terms of controlling the molecular weight of the polymer and the copolymerizability of the polar monomer, R ¹⁶ and R ¹⁷ are preferably a cyclohexyl group which may be substituted with a linear or branched alkyl group having 3 to 10 carbon atoms, and more preferably a cyclohexyl group substituted with a linear or branched alkyl group having 3 to 10 carbon atoms, and are preferably a 2-isopropyl-5-methylcyclohexyl group (menthyl group).

In addition, examples of the aryl group having 6 to 20 carbon atoms which may have a functional group in R ¹⁶ and R ¹⁷ include a phenyl group, a naphthyl group, an anthracenyl group, etc. which may have a functional group and may be substituted with a linear or branched alkyl group having 3 to 10 carbon atoms. The aryl group having 6 to 20 carbon atoms is preferably substituted with a group containing at least one of an oxygen atom and a nitrogen atom. When the aryl group having 6 to 20 carbon atoms is substituted with a group containing at least one of an oxygen atom and a nitrogen atom, the functional group is preferably substituted at the ortho position with respect to the carbon bonded to phosphorus. This is because at least one of the oxygen atom and the nitrogen atom in R ¹⁶ and R ¹⁷ can be spatially arranged so as to have an interaction with the transition metal M.

Preferable specific examples of R ¹⁶ and R ¹⁷ include a 2,6-dimethoxyphenyl group, a 2,4
,6-trimethoxyphenyl group, 4-methyl-2,6-dimethoxyphenyl group, 4-t-butyl-2,6-dimethoxyphenyl group, 1,3-dimethoxy-2-naphthyl group, 2,6-diethoxyphenyl group, 2,4,6-triethoxyphenyl group, 4-methyl-2,6-diethoxyphenyl group, 4-t-butyl-2,6-diethoxyphenyl group, 1,3-diethoxy-2-naphthyl group, 2,6-diphenoxyphenyl group, 2,4,6 -triphenoxyphenyl group, 4-methyl-2,6-diphenoxyphenyl group, 4-t-butyl-2,6-diphenoxyphenyl group, 1,3-diphenoxy-2-naphthyl group, 2,6-dimethoxymethylphenyl group, 2,4,6-trimethoxymethylphenyl group, 4-methyl-2,6-dimethoxymethylphenyl group, 4-t-butyl-2,6-dimethoxymethylphenyl group, 1,3-dimethoxymethyl-2-naphthyl group, 2,6-di phenoxymethylphenyl group, 2,4,6-triphenoxymethylphenyl group, 4-methyl-2,6-diphenoxymethylphenyl group, 4-t-butyl-2,6-diphenoxymethylphenyl group, 1,3-diphenoxymethyl-2-naphthyl group, 2,6-di(2-methoxyethyl)phenyl group, 2,4,6-tri(2-methoxyethyl)phenyl group, 4-methyl-2,6-di(2-methoxyethyl)phenyl group, 4-t-butyl- Examples of the phenyl group include a 2,6-di(2-methoxyethyl)phenyl group, a 1,3-di(2-methoxyethyl)-2-naphthyl group, a 2,6-di(2-phenoxyethyl)phenyl group, a 2,4,6-tri(2-phenoxyethyl)phenyl group, a 4-methyl-2,6-di(2-phenoxyethyl)phenyl group, a 4-t-butyl-2,6-di(2-phenoxyethyl)phenyl group, and a 1,3-di(2-phenoxyethyl)-2-naphthyl group.

R ¹⁶ or R ¹⁷ may be bonded to A to form a ring structure. Specific examples include structures described in paragraphs 0120 to 0121 of JP 2018-141138 A (note that the examples here show the case where the substituent R ¹⁶ and A are bonded to form a ring structure, and P and Q have the same meaning as in general formula (104) of the present disclosure).

Among the compounds represented by general formula (104) of the present disclosure, the compound represented by the following general formula (105) is preferred from the viewpoint of polymer production efficiency.

（一般式（１０５）中、Ｍ、Ｌ、Ｒ^１５、Ｒ^１６及びＲ^１７は、それぞれ前記一般式（１０４）と同義であり、Ｒ^１１１、Ｒ^１１２、Ｒ^１１３及びＲ^１１４はそれぞれ独立に、水素原子、炭素数１～３０の炭化水素基、又は官能基である。）

In formula (105), M, L, R ¹⁵ , R ¹⁶ and R ¹⁷ are each defined as in formula (104), and R ¹¹¹ , R ¹¹² , R ¹¹³ and R ¹¹⁴ each independently represent a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or a functional group.

In the general formula (105), the hydrocarbon group having 1 to 30 carbon atoms and the functional group in R ¹¹¹ , R ¹¹² , R ¹¹³ and R ¹¹⁴ may be the same as those explained in A above.
Among these, the bulkier R ¹¹¹ tends to give a polymer with a higher molecular weight, and functional groups such as a t-butyl group, a trimethylsilyl group, a phenyl group, a 9-anthracenyl group, a 4-t-butylphenyl group, a 2,4-di-t-butylphenyl group, a pentafluorophenyl group, etc. may be appropriately selected.

The transition metal complexes used in the present disclosure can be prepared by conventional methods.
The transition metal-containing catalyst used in the present disclosure contains the above-mentioned transition metal complex as a main catalyst component, and may be used in combination with an activator, a carrier, etc. Examples of the activator include alkylalumoxanes and boron-containing compounds, which are cocatalysts used in metallocene catalysts.

As the carrier, any carrier can be used as long as it does not interfere with the gist of the present invention. In general, inorganic oxides and polymer carriers are preferably used.
Specifically, SiO ₂ , Al ₂ O ₃ , MgO, ZrO ₂ , TiO ₂ , B ₂ O ₃ , CaO, ZnO, BaO, ThO ₂ and the like or mixtures thereof can be mentioned, and mixed oxides such as SiO ₂ -Al ₂ O ₃ , SiO ₂ -V ₂ O ₅ , SiO ₂ -TiO ₂ , SiO ₂ -MgO, SiO ₂ -Cr ₂ O ₃ can also be used, and inorganic silicates, polyethylene carriers, polypropylene carriers, polystyrene carriers, polyacrylic acid carriers, polymethacrylic acid carriers, polyacrylic acid ester carriers, polyester carriers, polyamide carriers, polyimide carriers, etc. can be used. There are no particular limitations on the particle size, particle size distribution, pore volume, specific surface area, etc. of these carriers, and any one can be used.

(6-2) Polymerization method for polar group-containing olefin copolymer:
The polymerization method for the polar group-containing olefin copolymer in the present disclosure is not limited.
The polymerization method used may be solution polymerization in which all of the polymer produced is dissolved in a medium, slurry polymerization in which at least a portion of the polymer produced becomes a slurry in a medium, bulk polymerization in which the liquefied monomer itself is used as a medium, or high pressure ionic polymerization in which at least a portion of the polymer produced is dissolved in the monomer liquefied at high temperature and high pressure.
The polymerization method may be any of batch polymerization, semi-batch polymerization, and continuous polymerization.
Specific manufacturing processes and conditions are disclosed in, for example, Japanese Patent Application Laid-Open No. 2010-260913 and Japanese Patent Application Laid-Open No. 2010-202647.

The unreacted monomers and the medium may be separated from the resulting polymer and recycled for reuse. When recycling, these monomers and the medium may be purified and reused, or may be reused without purification. Conventional known methods can be used to separate the resulting polymer from the unreacted monomers and the medium. For example, methods such as filtration, centrifugation, solvent extraction, and reprecipitation using a poor solvent can be used.

The copolymerization temperature, copolymerization pressure and copolymerization time are not particularly limited, but usually, the optimum settings can be made within the following ranges, taking into consideration the productivity and process capacity.
That is, the copolymerization temperature is usually −20° C. to 290° C., preferably 0° C. to 250° C., more preferably 0° C. to 200° C., even more preferably 10° C. to 150° C., and particularly preferably 20° C. to 100° C. The copolymerization pressure is 0.1 MPa to 100 MPa, preferably 0.3 MPa to 90 MPa, more preferably 0.5 MPa to 80 MPa, even more preferably 1.0 MPa to 70 MPa, and particularly preferably 1.3 MPa to 60 MPa. The copolymerization time can be selected from the range of 0.1 minute to 50 hours, preferably 0.5 minutes to 40 hours, and more preferably 1 minute to 30 hours.
In the present invention, the polymerization is generally carried out under an inert gas atmosphere, for example, a nitrogen or argon atmosphere, and preferably a nitrogen atmosphere.

There are no particular limitations on the supply of catalyst and monomer to the polymerization reactor, and various supply methods can be used depending on the purpose. For example, in the case of batch polymerization, a method can be used in which a predetermined amount of monomer is supplied to the copolymerization reactor in advance and a catalyst is supplied thereto. In this case, additional monomer or additional catalyst may be supplied to the copolymerization reactor. In addition, in the case of continuous polymerization, a method can be used in which a predetermined amount of monomer and catalyst are supplied to the copolymerization reactor continuously or intermittently to carry out the copolymerization reaction continuously.

Regarding the control of the copolymer composition, a method of controlling by changing the monomer supply ratio can be generally used. Other methods include a method of controlling the copolymer composition by utilizing the difference in monomer reactivity ratio due to the difference in catalyst structure, and a method of controlling the copolymer composition by utilizing the polymerization temperature dependency of the monomer reactivity ratio.
The molecular weight of the copolymer can be controlled by a conventional method, such as a method of controlling the molecular weight by controlling the polymerization temperature, a method of controlling the molecular weight by controlling the monomer concentration, or a method of controlling the molecular weight by controlling the ligand structure in a transition metal complex.

(7) Decomposition method of polar group-containing olefin copolymer The polar group-containing olefin copolymer of the present disclosure can be decomposed by various methods. Examples of the decomposition method include a method of decomposing by irradiation with light including ultraviolet light, a method of decomposing by electromagnetic waves with higher energy, and a method of decomposing by oxidation with ozone, oxidation with peroxides, and oxidation with other oxidizing agents. Among these, the method of decomposing by irradiation with electromagnetic waves is preferred because it does not require other chemical substances, and among them, the method of decomposing by irradiation with light including ultraviolet light is desirable from the viewpoints of safety and ease of designing a generating device.

II. Resin Composition The resin composition of the present disclosure is characterized by containing the polar group-containing olefin copolymer of the present disclosure.
Since the resin composition of the present disclosure contains the polar group-containing olefin copolymer of the present disclosure, at least the polar group-containing olefin copolymer of the present disclosure is cleaved in response to light including ultraviolet light, resulting in a resin composition that can be easily decomposed artificially or by natural actions.
Therefore, like the polar group-containing olefin copolymer of the present disclosure, the resin composition of the present disclosure is expected to be a promising functional material, mainly in the recycling field.

The resin composition of the present disclosure is not particularly limited as long as it contains the polar group-containing olefin copolymer of the present disclosure.
Among the other components, as the other resin, other olefin polymers are preferably used.
Other olefin polymers include, for example, low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, ethylene propylene rubber, ethylene propylene diene rubber, polybutene, polystyrene, polyvinyl chloride, and the like.
Furthermore, in addition to the olefin-based polymers, various resins can be used in the resin composition of the present disclosure, specifically, various nylon resins, various polyamides, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), various polyesters, polycarbonate resins, EVOH, EVA, PMMA, PMA, various engineering plastics, polylactic acid, celluloses, natural rubbers, polyurethane, PVC, fluorine-based resins such as Teflon (registered trademark), inorganic polymers such as silicone resins, and the like.

Furthermore, the resin composition of the present disclosure may further contain known additives such as antioxidants, ultraviolet absorbers, light stabilizers, lubricants, antistatic agents, antifogging agents, antiblocking agents, processing aids, coloring pigments, crosslinking agents, foaming agents, inorganic or organic fillers, and flame retardants in accordance with a conventional method.
As additives, for example, one or more of antioxidants (phenol-based, phosphorus-based, sulfur-based), lubricants, antistatic agents, light stabilizers, ultraviolet absorbers, etc. can be appropriately used in combination. As fillers, calcium carbonate, talc, metal powders (aluminum, copper, iron, lead, etc.), silica stone, diatomaceous earth, alumina, gypsum, mica, clay, asbestos, graphite, carbon black, titanium oxide, etc. can be mentioned.

The resin composition of the present disclosure can be obtained, for example, by mixing the polar group-containing olefin copolymer of the present disclosure with other resins and, if necessary, various additives, and kneading the mixture in a kneading extruder, Banbury mixer, or the like.

The resin composition of the present disclosure can be used for hollow plastic molded products such as containers, bottles, and tanks, extrusion molded products such as sheets, films, and bags, and injection molded products such as caps. It can be particularly suitable for use in thin-walled molded products that are easily exposed to ultraviolet rays even to the inside.

Next, the present disclosure will be specifically explained using examples, but the present disclosure is not limited by these examples as long as they do not deviate from the gist of the disclosure. The physical properties of the polar group-containing olefin copolymer and the like were measured by the following methods.

[Structure of Polar Group-Containing Olefin Copolymer]
The structure of the polar group-containing olefin copolymer was determined by ¹ H-NMR and ¹³ C-NMR analysis using Ascend 500 manufactured by BRUKER Co., Ltd. or AVANCE 400 manufactured by BRUKER Co., Ltd.
The NMR measurements were performed at 120° C. using 1,1,2,2-tetrachloroethane-d2 as a solvent, with a polymer concentration of 5% by mass for ¹ H-NMR and 15% by mass for ¹³ C-NMR. Alternatively, some of the NMR measurements were performed at 120° C. by heating and dissolving about 150 mg of the polar group-containing olefin copolymer in 2.4 mL of a mixed solvent of 1,2-dichlorobenzene:bromobenzene-d5=1:2 to prepare a homogeneous solution.
^13C -NMR was measured using chromium(III) acetylacetonate as a relaxation reagent using the inverse gated decoupling method (9.0 microsecond 90° pulse, spectrum width: 31 kHz, relaxation time: 10 seconds, acquisition time: 10 seconds, FID accumulation number 5,000 to 10,000), and quantitative analysis was performed. Alternatively, a part of ^13C -NMR was measured using the inverse gated decoupling method (15.8 microsecond 90° pulse, spectrum width: 25 kHz, relaxation time: 50 seconds, acquisition time: 1.5 seconds, FID accumulation number 1,024), and quantitative analysis was performed.

[Number average molecular weight and weight average molecular weight]
The number average molecular weight and the weight average molecular weight were calculated by size exclusion chromatography (solvent: 1,2-dichlorobenzene, temperature: 145° C.) using polystyrene as a molecular weight standard substance, using a high-temperature GPC apparatus, HLC-8321GPC/HT, manufactured by Tosoh Corporation, equipped with a TSKgel GMHHR-H(S)HT column (two columns of 7.8 mm I.D.×30 cm in series), manufactured by Tosoh Corporation, or by size exclusion chromatography (solvent: 1,2-dichlorobenzene, temperature: 140° C.) using polystyrene as a molecular weight standard substance, using a high-temperature GPC apparatus, ALC/GPC 150C, manufactured by Waters Corporation, equipped with an AT-806MS column (three columns of 8.0 mm I.D.×25 cm in series), manufactured by Showa Denko K.K.

[Ultraviolet (UV) irradiation experiment procedure 1]
100 mg of each polymer sample was placed in a 3.5 mL vial (body made of colorless glass, cap made of white PP). The sample holder was made of aluminum. The distance between the backing (aluminum sample holder) and the sample was 5 mm (equal to the radius of the glass vial).
For ultraviolet irradiation, a Super Xenon Weather Meter SX75 manufactured by Suga Test Instruments Co., Ltd. was used. A xenon lamp was used as the light source. The inner filter was quartz, and the outer filter was #295. The irradiance was 60 W/ ^m2 . The test conditions were in accordance with the industry standard (JIS K7350-2). The temperature setting was 65°C at the black standard temperature. The humidity setting was 50%, but this was the humidity outside the vial. There was no spray setting. There was no dark time. The irradiation time was 50 hours.
[Ultraviolet (UV) irradiation experiment procedure 2]
100 mg of each polymer sample was placed in a 3.5 mL vial (body made of colorless glass, cap made of white PP). The sample holder was made of aluminum. The distance between the backing (aluminum sample holder) and the sample was 5 mm (equal to the radius of the glass vial).
For ultraviolet irradiation, a super xenon weather meter Ci4000 manufactured by ATLAS was used. A xenon lamp was used as the light source. The inner filter was made of borosilicate, and the outer filter was made of borosilicate. The irradiance was set to 60 W/ ^m2 . The test conditions were based on the industry standard (ISO16474), with the only change being that the black panel temperature was set to 65°C. The humidity setting was set to 50%, but this was the humidity outside the vial. There was no spray setting. There was no dark time. The irradiation time was set to 100 hours.

[Synthesis of transition metal complexes]
(Synthesis Example 1)
A transition metal complex (A) represented by the following chemical formula (A), in which R is menthyl (2-isopropyl-5-methylcyclohexyl) and Lut is 2,6-dimethylpyridine, was synthesized as described in JP2017-031300A.

(Synthesis Example 2)
Transition metal complex (B) represented by the following chemical formula (B), in which R is menthyl (2-isopropyl-5-methylcyclohexyl), Lut is 2,6-dimethylpyridine, and TMS is trimethylsilyl, was synthesized as described in Japanese Patent No. 6358074.

Example 1
To a 2.4 L autoclave, toluene (400 mL) as a solvent and 2,3-di(4-bromophenyl)cyclopropen-1-one (2.98 g, 8.2 mmol) as a monomer (B) were sequentially added in a nitrogen atmosphere. The autoclave was pressurized with ethylene (monomer (A)) (3.0 MPa), and a transition metal complex (A) (139 mg, 0.20 mmol) as a catalyst was added at a reaction temperature of 80° C. and stirred for 1 hour. A toluene solution of 1,2-butanediol (1 M, 10 mL) was added, the autoclave was returned to room temperature, and acetone (500 mL) was added. The precipitated solid was collected by filtration, washed with acetone (500 mL x 2), and dried under reduced pressure. The polar group-containing olefin copolymer 1 obtained was 25.01 g. The catalytic activity was 125 kg/mol/h.
The results of various analyses of the polar group-containing olefin copolymer 1 are shown in Table 1. The ¹³ C-NMR spectrum of the polar group-containing olefin copolymer 1 obtained is shown in Figure 2.
The obtained polar group-containing olefin copolymer was irradiated with ultraviolet light according to procedure 2. The results of various analyses after ultraviolet light irradiation are shown in Table 1.

Example 2
The polar group-containing olefin copolymer 1 of Example 1 was used, and ultraviolet irradiation was carried out according to Procedure 1. The results of various analyses after ultraviolet irradiation are shown in Table 1.

Example 3
In a 50 mL autoclave, in a nitrogen atmosphere, transition metal complex (A) (6.9 mg, 0.010 mmol) as a catalyst, toluene (10 mL) as a solvent, and 2,3-diphenylcyclopropene-1-one (206.1 mg, 1.0 mmol) as a monomer (B) were sequentially added. The autoclave was pressurized with ethylene (monomer (A)) (3.0 MPa) and stirred at a reaction temperature of 80° C. for 12 hours. The autoclave was returned to room temperature, and methanol (20 mL) was added. The precipitated solid was collected by filtration, washed with methanol, and dried under reduced pressure. The amount of the polar group-containing olefin copolymer 2 obtained was 2035 mg. The catalytic activity was 17 kg/mol/h.
The results of various analyses of the polar group-containing olefin copolymer 2 are shown in Table 1. The ¹³ C-NMR spectrum of the polar group-containing olefin copolymer 2 obtained is shown in Figure 3.
The obtained polar group-containing olefin copolymer was irradiated with ultraviolet light according to procedure 1. The results of various analyses after ultraviolet light irradiation are shown in Table 1. Furthermore, the results of ¹ H-NMR measurements before and after ultraviolet light irradiation are shown in FIG.

(Comparative Example 1)
To a 2.4 L autoclave, toluene (400 mL) as a solvent and 3-ethyl-2-phenylcyclopropen-1-one (3.12 g, 20 mmol) as a monomer (B) were sequentially added in a nitrogen atmosphere. The autoclave was pressurized with ethylene (monomer (A)) (3.0 MPa), and a transition metal complex (A) (278 mg, 0.40 mmol) as a catalyst was added at a reaction temperature of 80° C. and stirred for 1 hour. A toluene solution of 1,2-butanediol (1 M, 10 mL) was added, the autoclave was returned to room temperature, and Equinene (registered trademark) F-1 (500 mL, manufactured by Japan Alcohol Sales Co., Ltd.) was added. The precipitated solid was collected by filtration, washed with Equinene (registered trademark) F-1 (500 mL x 2), and dried under reduced pressure. The comparative polar group-containing olefin copolymer i obtained was 3720 mg. The catalytic activity was 9.3 kg/mol/h.
The results of various analyses of the comparative polar group-containing olefin copolymer i are shown in Table 1. ^{The 13} C-NMR spectrum of the obtained comparative polar group-containing olefin copolymer i is shown in Figure 4.
The obtained comparative polar group-containing olefin copolymer was irradiated with ultraviolet light according to procedure 1. The results of various analyses after ultraviolet light irradiation are shown in Table 1.

(Comparative Example 2)
Toluene (400 mL) as a solvent and 2-diethylamino-3-(4-methoxyphenyl)cyclopropen-1-one (578 mg, 2.5 mmol, containing about 10 mol% of 2-diethylamino-3-(2-methoxyphenyl)cyclopropen-1-one as an impurity) as monomer (B) were sequentially added to a 2.4 L autoclave in a nitrogen atmosphere. The autoclave was pressurized with ethylene (monomer (A)) (3.0 MPa), and transition metal complex (A) (278 mg, 0.40 mmol) as a catalyst was added at a reaction temperature of 80° C. Ten minutes after the start of the reaction, 2-diethylamino-3-(4-methoxyphenyl)cyclopropen-1-one (578 mg, 2.5 mmol) was further added. One hour after the addition of the catalyst, a toluene solution of 1,2-butanediol (1 M, 10 mL) was added, the autoclave was returned to room temperature, and Equinene (registered trademark) F-1 (500 mL) was added. The precipitated solid was collected by filtration, washed with Equinene (registered trademark) F-1 (500 mL x 2), and dried under reduced pressure. The comparative polar group-containing olefin copolymer ii was obtained in an amount of 9640 mg. The catalytic activity was 24.1 kg/mol/h.
The results of various analyses of the comparative polar group-containing olefin copolymer ii are shown in Table 1. ^{The 13} C-NMR spectrum of the obtained comparative polar group-containing olefin copolymer ii is shown in Figure 5.
The obtained comparative polar group-containing olefin copolymer was irradiated with ultraviolet light according to procedure 1. The results of various analyses after ultraviolet light irradiation are shown in Table 1.

(Comparative Example 3)
A copolymer of ethylene and carbon monoxide was synthesized based on the description in the non-patent literature Angew. Chem. Ind. Ed. 2019, 58, 12955. The results of various analyses of the comparative polar group-containing olefin copolymer iii are shown in Table 1.
The obtained comparative polar group-containing olefin copolymer was irradiated with ultraviolet light according to procedure 1. The results of various analyses after ultraviolet light irradiation are shown in Table 1.

(Comparative Example 4)
To a 2.4 L autoclave, toluene (1000 mL) as a solvent and tert-butyl 5-norbornene-2-carboxylate (7.9 mL, 40 mmol) were sequentially added in a nitrogen atmosphere. The autoclave was pressurized with ethylene (monomer (A)) (2.5 MPa) and purified nitrogen at 0.5 MPa, and a transition metal complex (B) (28 mg, 0.035 mmol) as a catalyst was added at a reaction temperature of 80° C. and stirred for 30 minutes. A toluene solution of 1,2-butanediol (1 M, 10 mL) was added, the autoclave was returned to room temperature, and Equinene (registered trademark) F-1 (1000 mL, manufactured by Japan Alcohol Sales Co., Ltd.) was added. The precipitated solid was collected by filtration, washed with Equinene (registered trademark) F-1 (1000 mL x 2), and dried under reduced pressure. The comparative polyethylene polymer iv obtained was 26.69 g.
The results of various analyses of the comparative polyethylene polymer iv are shown in Table 1. The obtained comparative polyethylene polymer was irradiated with ultraviolet light according to procedure 1. The results of various analyses after ultraviolet light irradiation are shown in Table 1.

In the table, Br-Ph- represents a 4-bromophenyl group, Ph- represents a phenyl group, Et- represents an ethyl group, (Et) ₂ N- represents a diethylamino group, and MeO-Ph- represents a 4-methoxyphenyl group.

In Table 1, the structure of α in the examples refers to the structural unit (B) represented by the general formula (I) above, and in the comparative examples refers to a structure constituted by ^Rx and ^Ry that do not correspond to ^Rx and ^Ry in the structural unit (B) represented by the general formula (I) above. The structure of β is a structural unit represented by the formula (II) above.
In Table 1, the structure α (mol %) means the content ratio of the structural units (B) to α represented by the general formula (I) when the total structural units of the polymer are taken as 100 mol %, and the structure β (mol %) means the content ratio of the structural unit represented by the formula (II) when the total structural units of the polymer are taken as 100 mol %.

From the comparison between the examples and the comparative examples, when both ^Rx and ^Ry are aromatic groups, it is shown that the molecular weight is significantly reduced after ultraviolet irradiation, and the molecular weight distribution Mw/Mn is expanded.In addition, from the NMR analysis (Figure 8) of the polar group-containing olefin copolymer 2 after ultraviolet irradiation, it is found that the peak derived from the enone structure is reduced.From these results, it is clear that the polar olefin copolymer containing the enone structure in which both ends of the unsaturated bond are substituted with aromatic groups has excellent decomposability.

The polar group-containing olefin copolymer of the present disclosure can be easily decomposed artificially or by natural processes because a specific enone structure introduced as a structural unit into the main chain is cleaved by itself in response to light including ultraviolet light, and therefore the copolymer can be used as a decomposable resin.
The polar group-containing olefin copolymer of the present disclosure is itself an easily decomposable resin material and a photodecomposable resin material, and can also function as a decomposability imparting agent or a disintegrant that imparts decomposability to a resin composition mixed with other materials through its own decomposition.
The polar group-containing olefin copolymer of the present disclosure is expected to be a promising functional material, mainly in the recycling field. In addition, since the polar group-containing olefin copolymer of the present disclosure is expected to be decomposed by ultraviolet light in natural sunlight, it is expected to be one of the measures to address environmental plastic problems and marine plastic problems.

Claims (7)

A structural unit (A) derived from one or more monomers selected from the group consisting of ethylene and olefins having 3 to 20 carbon atoms;
A structural unit (B) represented by the following general formula (I),
A polar group-containing olefin copolymer comprising:

(In general formula (I), R ^x and R ^y each independently represent an aromatic hydrocarbon group having 6 to 30 carbon atoms or an aromatic heterocyclic group having 2 to 8 carbon atoms which may be substituted with at least one substituent selected from the group consisting of a functional group containing at least one selected from the group consisting of an oxygen atom, a sulfur atom, a halogen atom, and a nitrogen atom, and an aliphatic hydrocarbon group, and R ^x and R ^y may be bonded to each other via -O-, -S-, -NR ^z (wherein R ^z is a hydrogen atom, an acyl group having 1 to 6 carbon atoms, or an aliphatic hydrocarbon group having 1 to 6 carbon atoms)-, an aliphatic hydrocarbon group, or a combination thereof to form a 7-10-membered ring.) The structural unit (B) represented by the general formula (I) is derived from one or more monomers selected from the group consisting of polar group-containing monomers represented by the following general formula (1):

(In general formula (1), R ^x and R ^y each independently represent an aromatic hydrocarbon group having 6 to 30 carbon atoms or an aromatic heterocyclic group having 2 to 8 carbon atoms which may be substituted with at least one substituent selected from the group consisting of a functional group containing at least one selected from the group consisting of an oxygen atom, a sulfur atom, a halogen atom, and a nitrogen atom, and an aliphatic hydrocarbon group, and R ^x and R ^y may be bonded to each other via -O-, -S-, -NR ^z (wherein R ^z is a hydrogen atom, an acyl group having 1 to 6 carbon atoms, or an aliphatic hydrocarbon group having 1 to 6 carbon atoms)-, an aliphatic hydrocarbon group, or a combination thereof to form a 7-10-membered ring.) The polar group-containing olefin copolymer according to claim 1 or 2, further comprising a structural unit (C) derived from one or more monomers selected from the group consisting of a polar group-containing monomer (c-1) represented by the following general formula (2) and a polar group-containing monomer (c-2) represented by the following general formula (3):

(In the general formula (2), R ¹ and R ² are each independently a hydrogen atom, an ester group having 1 to 30 carbon atoms, an acyloxy group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, a cyano group, an amino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, an amide group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, an imino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, a halogen-substituted hydrocarbon group having 1 to 30 carbon atoms, or a hydrocarbon group having 1 to 30 carbon atoms which may be substituted with a functional group containing at least one selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom, and a phosphorus atom, and at least one of R ¹ and R ² is a group containing at least one of an oxygen atom and a nitrogen atom.)

(In general formula (3), R ³ to R ¹⁰ are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms. n is 0 or a positive integer, and when n is 2 or more, R ⁷ to R ¹⁰ may be the same or different in each repeating unit. R ¹¹ to R ¹⁴ are each independently a hydrogen atom, an ester group having 1 to 30 carbon atoms, an acyloxy group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, a cyano group, an amino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, an amide group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, an imino group which may be substituted with a hydrocarbon group having 1 to 30 carbon atoms, ^or a hydrocarbon group having 1 to 30 carbon atoms which may be substituted with a functional group containing at least one selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom, and a phosphorus atom; and At least one ^of R ¹¹ and R ¹² and R 13 and R ¹⁴ may be bonded together to form a divalent hydrocarbon group , ^and R ¹¹ or R ¹² and R ¹³ or R ¹⁴ may be bonded together to form a ring. The polar group-containing olefin copolymer according to any one of claims 1 to 3, characterized in that the structural unit (A) is a structural unit derived from ethylene. The polar group-containing olefin copolymer according to any one of claims 1 to 4, which is an easily decomposable resin material. The polar group-containing olefin copolymer according to any one of claims 1 to 5, which is a photodecomposable resin material. A resin composition comprising the polar group-containing olefin copolymer according to any one of claims 1 to 6 and a resin other than the polar group-containing olefin copolymer .

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