WO2025134689A1 - Method for producing vinyl polymer and living radical polymerization control agent - Google Patents

Abstract

The method for producing a vinyl polymer comprises polymerizing a vinyl monomer in the presence of a compound represented by formula (1). In formula (1), R⁰ and R¹ are each independently a hydrogen atom, a cyano group, an optionally substituted monovalent hydrocarbon group, an optionally substituted monovalent heterocyclic group, an acetyl group, or -COOY¹. R², when n is 1, is an optionally substituted monovalent hydrocarbon group, an optionally substituted monovalent heterocyclic group, an acetyl group, or -COOY² and, when n is 2 or more, is an n-valent group bonded by an ester bond to the carbon atom to which R⁰ and R¹ are bonded, the remainder having a chain hydrocarbon structure optionally having an ether bond. X is an alkyl group or a monovalent electron-withdrawing group.

Description

Method for producing vinyl polymer and living radical polymerization control agent

CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to Japanese Patent Application No. 2023-217241, filed on December 22, 2023, the entire contents of which are incorporated herein by reference.
The present disclosure relates to a method for producing a vinyl polymer and a living radical polymerization controller.

Radical polymerization is widely used industrially because it allows monomers to be polymerized easily and polymers to be obtained economically. However, radical polymerization has the disadvantage that it is difficult to synthesize polymers with fully controlled molecular weight distribution and molecular structure because the active species is neutral and side reactions such as termination reactions cannot be controlled. In response to this, in recent years, there has been active development of living radical polymerization, a polymerization method that consists of an initiation reaction and a propagation reaction and does not involve side reactions.

There are various known living radical polymerization methods, such as atom transfer radical polymerization (ATRP), reversible addition-fragmentation chain transfer polymerization (RAFT), and polymerization using an organotellurium compound (TERP). Of these, atom transfer radical polymerization (ATRP) is a method that uses an organic halide or the like as a polymerization initiator and a transition metal complex as a catalyst (see, for example, Patent Document 1). The ATRP method is useful as a method for producing vinyl polymers having specific functional groups at the polymer ends, since the terminals of the living polymers obtained by the polymerization reaction have halogens, which are relatively advantageous for functional group conversion reactions, and it is easy to introduce desired functional groups to the polymer terminals.

In the reversible addition-fragmentation chain transfer polymerization method (RAFT method), controlled polymerization proceeds through a reversible chain transfer reaction in the presence of a polymerization control agent (RAFT agent) having a thiocarbonylthio group, such as a dithioester compound, a xanthate compound, a trithiocarbonate compound, or a dithiocarbamate compound, and a general free radical polymerization initiator (see, for example, Patent Document 2). The RAFT method has a wide range of monomer options and has been widely used in recent years as a method for producing a variety of well-controlled block copolymers.

The polymerization method using an organotellurium compound (TERP method) is a method in which an organotellurium compound is used as a polymerization control agent (see, for example, Patent Document 3). The TERP method also has a wide range of monomers to choose from, and it is possible to carry out living polymerization of many vinyl monomers such as styrene, various (meth)acrylates, (meth)acrylic acid, vinylpyrrolidone, etc.

Special Publication No. 2000-500516 Special Publication No. 2000-515181 International Publication No. 2004/014848

However, the ATRP method is prone to deep coloration due to transition metals, and there are concerns that it will be costly if it is necessary to remove the metal for safety reasons. Furthermore, with the RAFT method, coloration and a sulfur odor derived from thiocarbonylthio groups can be problematic. With the TERP method, there can be problems with tellurium breath that has a garlic-like odor derived from organotellurium compounds, and with teratogenicity. Therefore, it is desirable to develop a new method for living radical polymerization that differs from conventional methods.

The present disclosure has been made in light of these circumstances, and one of its objectives is to provide a new production method that can produce vinyl polymers with precisely controlled molecular weights and molecular weight distributions. Another objective is to provide a new living radical polymerization control agent for use in living radical polymerization.

The inventors conducted extensive research and discovered a new living radical polymerization inhibitor, which led to the completion of the present disclosure. Specifically, the present disclosure provides the following method for producing a vinyl polymer and living radical polymerization inhibitor.

（式（１）中、ｎは１～６の整数である。Ｒ^０及びＲ^１は、それぞれ独立して、水素原子、シアノ基、置換基を有していてもよい１価の炭化水素基、置換基を有していてもよい１価の複素環基、アセチル基又は－ＣＯＯＹ^１である。Ｙ^１は、水素原子又は置換基を有していてもよい１価の炭化水素基である。Ｒ^２は、ｎが１の場合に、置換基を有していてもよい１価の炭化水素基、置換基を有していてもよい１価の複素環基、アセチル基又は－ＣＯＯＹ^２であり、ｎが２以上の場合に、Ｒ^０とＲ^１とが結合する炭素原子に対しエステル結合で結合し、残りの部分がエーテル結合を有していてもよい鎖状炭化水素構造を有するｎ価の基である。Ｙ^２は、水素原子又は置換基を有していてもよい１価の炭化水素基である。Ｘは、アルキル基又は１価の電子求引性基である。ｍは０～５の整数である。）
〔２〕　活性エネルギー線を照射又は熱を付与して前記ビニル系モノマーを重合する、〔１〕のビニル系重合体の製造方法。
〔３〕　前記重合がリビングラジカル重合である、〔１〕又は〔２〕のビニル系重合体の製造方法。
〔４〕　重合温度が－１０℃～１２０℃である、〔１〕～〔３〕のいずれかのビニル系重合体の製造方法。
〔５〕　上記（１）中のＲ^１が、水素原子、シアノ基、置換基を有していてもよい１価の炭化水素基、アセチル基又は－ＣＯＯＹ^１である、〔１〕～〔４〕のいずれかのビニル系重合体の製造方法。
〔６〕　上記式（１）中のｎが１である、〔１〕～〔５〕のいずれかのビニル系重合体の製造方法。
〔７〕　上記式（１）中のＲ^２が、置換基を有していてもよい炭素数６～２０の１価の芳香族炭化水素基、アセチル基、ピリジル基又は－ＣＯＯＹ^２である、〔６〕のビニル系重合体の製造方法。
〔８〕　上記式（１）中のｎが２以上である、〔１〕～〔５〕のいずれかのビニル系重合体の製造方法。
〔９〕　前記ビニル系重合体が、第１重合体ブロックと第２重合体ブロックとを有するブロック共重合体であり、上記式（１）で表される化合物の存在下で、前記第１重合体ブロックを構成するビニル系モノマーを重合することにより前記第１重合体ブロックを得る工程と、前記第１重合体ブロックの存在下で、前記第２重合体ブロックを構成するビニル系モノマーを重合する工程と、を含む、〔１〕～〔８〕のいずれかのビニル系重合体の製造方法。
〔１０〕　下記式（１）で表されるリビングラジカル重合制御剤。

（式（１）中、ｎは１～６の整数である。Ｒ^０及びＲ^１は、それぞれ独立して、水素原子、シアノ基、置換基を有していてもよい１価の炭化水素基、置換基を有していてもよい１価の複素環基、アセチル基又は－ＣＯＯＹ^１である。Ｙ^１は、水素原子又は置換基を有していてもよい１価の炭化水素基である。Ｒ^２は、ｎが１の場合に、置換基を有していてもよい１価の炭化水素基、置換基を有していてもよい１価の複素環基、アセチル基又は－ＣＯＯＹ^２であり、ｎが２以上の場合に、Ｒ^０とＲ^１とが結合する炭素原子に対しエステル結合で結合し、残りの部分がエーテル結合を有していてもよい鎖状炭化水素構造を有するｎ価の基である。Ｙ^２は、水素原子又は置換基を有していてもよい１価の炭化水素基である。Ｘは、アルキル基又は１価の電子求引性基である。ｍは０～５の整数である。）
〔１１〕　上記（１）中のＲ^１が、水素原子、シアノ基、置換基を有していてもよい炭素数１～２０の１価の炭化水素基、アセチル基又は－ＣＯＯＹ^１である、〔１０〕のリビングラジカル重合制御剤。
〔１２〕　上記式（１）中のｎが１である、〔１０〕又は〔１１〕のリビングラジカル重合制御剤。
〔１３〕　上記式（１）中のＲ^２が、置換基を有していてもよい炭素数６～２０の１価の芳香族炭化水素基、アセチル基、ピリジル基又は－ＣＯＯＹ^２である、〔１２〕のリビングラジカル重合制御剤。
〔１４〕　上記式（１）中のｎが２以上である、〔１０〕又は〔１１〕のリビングラジカル重合制御剤。 [1] A method for producing a vinyl polymer, comprising polymerizing a vinyl monomer in the presence of a compound represented by the following formula (1):

(In formula (1), n is an integer of 1 to 6. ^{R 0} and R ¹ are each independently a hydrogen atom, a cyano group, a monovalent hydrocarbon group which may have a substituent, a monovalent heterocyclic group which may have a substituent, an acetyl group, or -COOY ^1. Y ¹ is a hydrogen atom or a monovalent hydrocarbon group which may have a substituent. When n is 1, R ² is a monovalent hydrocarbon group which may have a substituent, a monovalent heterocyclic group which may have a substituent, an acetyl group, or -COOY ^2. When n is 2 or more, R 2 is an n-valent group which is bonded to the carbon atom to which R ⁰ and R ¹ are bonded via an ester bond and has a chain hydrocarbon structure in which the remaining portion may have an ether bond. Y ² is a hydrogen atom or a monovalent hydrocarbon group which may have a substituent. X is an alkyl group or a monovalent electron-withdrawing group. m is an integer of 0 to 5.)
[2] The method for producing a vinyl polymer according to [1], wherein the vinyl monomer is polymerized by irradiating the vinyl monomer with active energy rays or applying heat thereto.
[3] The method for producing a vinyl polymer according to [1] or [2], wherein the polymerization is living radical polymerization.
[4] The method for producing a vinyl polymer according to any one of [1] to [3], wherein the polymerization temperature is from -10°C to 120°C.
[5] The method for producing a vinyl polymer according to any one of [1] to [4], wherein R ¹ in the above (1) is a hydrogen atom, a cyano group, a monovalent hydrocarbon group which may have a substituent, an acetyl group, or -COOY ¹ .
[6] The method for producing a vinyl polymer according to any one of [1] to [5], wherein n in the formula (1) is 1.
[7] The method for producing a vinyl polymer according to [6], wherein ^R2 in the above formula (1) is a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, an acetyl group, a pyridyl group, or ^-COOY2 .
[8] The method for producing a vinyl polymer according to any one of [1] to [5], wherein n in the formula (1) is 2 or more.
[9] The method for producing a vinyl polymer according to any one of [1] to [8], wherein the vinyl polymer is a block copolymer having a first polymer block and a second polymer block, and the method comprises the steps of: obtaining the first polymer block by polymerizing a vinyl monomer constituting the first polymer block in the presence of a compound represented by formula (1) above; and polymerizing a vinyl monomer constituting the second polymer block in the presence of the first polymer block.
[10] A living radical polymerization inhibitor represented by the following formula (1):

(In formula (1), n is an integer of 1 to 6. ^{R 0} and R ¹ are each independently a hydrogen atom, a cyano group, a monovalent hydrocarbon group which may have a substituent, a monovalent heterocyclic group which may have a substituent, an acetyl group, or -COOY ^1. Y ¹ is a hydrogen atom or a monovalent hydrocarbon group which may have a substituent. When n is 1, R ² is a monovalent hydrocarbon group which may have a substituent, a monovalent heterocyclic group which may have a substituent, an acetyl group, or -COOY ^2. When n is 2 or more, R 2 is an n-valent group which is bonded to the carbon atom to which R ⁰ and R ¹ are bonded via an ester bond and has a chain hydrocarbon structure in which the remaining portion may have an ether bond. Y ² is a hydrogen atom or a monovalent hydrocarbon group which may have a substituent. X is an alkyl group or a monovalent electron-withdrawing group. m is an integer of 0 to 5.)
[11] The living radical polymerization inhibitor according to [10], wherein R ¹ in the above (1) is a hydrogen atom, a cyano group, a monovalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, an acetyl group, or -COOY ¹ .
[12] The living radical polymerization inhibitor according to [10] or [11], wherein n in the above formula (1) is 1.
[13] The living radical polymerization inhibitor according to [12], wherein ^R2 in the above formula (1) is a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, an acetyl group, a pyridyl group, or ^-COOY2 .
[14] The living radical polymerization inhibitor according to [10] or [11], wherein n in the above formula (1) is 2 or more.

According to the present disclosure, it is possible to provide a novel production method that can produce vinyl polymers with precisely controlled molecular weights and molecular weight distributions. In addition, according to the present disclosure, it is possible to provide a novel living radical polymerization control agent for use in living radical polymerization.

FIG. 1 shows the synthesis results of Example 1 ( ¹ H-NMR spectrum, ¹³ C-NMR spectrum, FT-IR spectrum, and DART-MS). FIG. 2 shows the synthesis results of Example 2 ( ¹ H-NMR spectrum, ¹³ C-NMR spectrum, FT-IR spectrum, and DART-MS). FIG. 3 shows the results of synthesis in Example 3 ( ¹ H-NMR spectrum, ¹³ C-NMR spectrum, and FT-IR spectrum). FIG. 4 shows the synthesis results of Example 4 ( ¹ H-NMR spectrum, ¹³ C-NMR spectrum, FT-IR spectrum, and DART-MS). FIG. 5 shows the synthesis results of Example 5 ( ¹ H-NMR spectrum, ¹³ C-NMR spectrum, FT-IR spectrum, and DART-MS). FIG. 6 shows the synthesis results ( ¹ H-NMR spectrum, ¹³ C-NMR spectrum, DART-MS) of Example 6. FIG. 7 shows the polymerization results of Example 7 (Time-Conv. plot, Conv.-Mn, Mw/Mn plot, GPC chart). FIG. 8 shows the polymerization results of Example 8 (Time-Conv. plot, Conv.-Mn, Mw/Mn plot, GPC chart). FIG. 9 shows the polymerization results of Example 9 (Time-Conv. plot, Conv.-Mn, Mw/Mn plot, GPC chart). FIG. 10 shows the polymerization results of Example 10 (Time-Conv. plot, Conv.-Mn, Mw/Mn plot, GPC chart). FIG. 11 is a diagram showing the polymerization results (GPC chart) of Example 11. FIG. 12 is a diagram showing the polymerization results (GPC chart) of Example 12. FIG. 13 shows the polymerization results of Example 13 (Time-Conv. plot, Conv.-Mn, Mw/Mn plot, GPC chart). FIG. 14 shows the polymerization results of Example 14 (Time-Conv. plot, Conv.-Mn, Mw/Mn plot, GPC chart). FIG. 15 shows the polymerization results of Example 15 (Time-Conv. plot, Conv.-Mn, Mw/Mn plot, GPC chart). FIG. 16 shows the polymerization results of Example 16 (Time-Conv. plot, Conv.-Mn, Mw/Mn plot, GPC chart). FIG. 17 shows the polymerization results of Example 17 (Time-Conv. plot, Conv.-Mn, Mw/Mn plot, GPC chart). FIG. 18 shows the polymerization results of Example 18 (Time-Conv. plot, Conv.-Mn, Mw/Mn plot, GPC chart).

The present disclosure will be described in detail below. In this specification, "(meth)acrylic" means acrylic and/or methacrylic, and "(meth)acrylate" means acrylate and/or methacrylate.

（式（１）中、ｎは１～６の整数である。Ｒ^０及びＲ^１は、それぞれ独立して、水素原子、シアノ基、置換基を有していてもよい１価の炭化水素基、置換基を有していてもよい１価の複素環基、アセチル基又は－ＣＯＯＹ^１である。Ｙ^１は、水素原子又は置換基を有していてもよい１価の炭化水素基である。Ｒ^２は、ｎが１の場合に、置換基を有していてもよい１価の炭化水素基、置換基を有していてもよい１価の複素環基、アセチル基又は－ＣＯＯＹ^２であり、ｎが２以上の場合に、Ｒ^０とＲ^１とが結合する炭素原子に対しエステル結合で結合し、残りの部分がエーテル結合を有していてもよい鎖状炭化水素構造を有するｎ価の基である。Ｙ^２は、水素原子又は置換基を有していてもよい１価の炭化水素基である。Ｘは、アルキル基又は１価の電子求引性基である。ｍは０～５の整数である。） <Method for producing vinyl polymer>
The method for producing a vinyl polymer according to the present disclosure involves polymerizing a vinyl monomer in the presence of a compound represented by the following formula (1) (hereinafter also referred to as a "tropolone derivative").

(In formula (1), n is an integer of 1 to 6. ^{R 0} and R ¹ are each independently a hydrogen atom, a cyano group, a monovalent hydrocarbon group which may have a substituent, a monovalent heterocyclic group which may have a substituent, an acetyl group, or -COOY ^1. Y ¹ is a hydrogen atom or a monovalent hydrocarbon group which may have a substituent. When n is 1, R ² is a monovalent hydrocarbon group which may have a substituent, a monovalent heterocyclic group which may have a substituent, an acetyl group, or -COOY ^2. When n is 2 or more, R 2 is an n-valent group which is bonded to the carbon atom to which R ⁰ and R ¹ are bonded via an ester bond and has a chain hydrocarbon structure in which the remaining portion may have an ether bond. Y ² is a hydrogen atom or a monovalent hydrocarbon group which may have a substituent. X is an alkyl group or a monovalent electron-withdrawing group. m is an integer of 0 to 5.)

Tropolone derivatives are useful as living radical polymerization control agents that precisely control the molecular weight and molecular weight distribution of the polymer produced in radical polymerization. That is, a living radical polymer can be obtained by polymerizing a vinyl monomer in the presence of a tropolone derivative. In particular, the manufacturing method disclosed herein is excellent in that it can obtain a vinyl polymer with precisely controlled molecular weight and molecular weight distribution while suppressing the generation of coloration and odor. Below, matters related to the manufacturing method disclosed herein will be described in detail.

<Tropolone derivatives>
Tropolone derivatives have a structure in which the hydrogen atom of the hydroxyl group of tropolone is replaced with a monovalent organic group. In the above formula (1), examples of the monovalent hydrocarbon group represented by R ⁰ , R ¹ , R ² , Y ¹ , and Y ² include an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, and an aromatic hydrocarbon group (aryl group, aralkyl group) having 6 to 20 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, an n-hexyl group, an isohexyl group, an n-heptyl group, and an n-octyl group. Of these, a linear or branched alkyl group having 1 to 6 carbon atoms is preferred, and a linear or branched alkyl group having 1 to 4 carbon atoms is more preferred.

Cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclohexyl, cycloheptyl, and cyclooctyl groups. Of these, cyclohexyl is preferred.

Aromatic hydrocarbon groups include aryl groups such as phenyl, methylphenyl, and naphthyl groups; and aralkyl groups such as benzyl and phenethyl groups. Of these, the phenyl group is preferred.

Examples of the monovalent heterocyclic group represented by R ⁰ , R ¹ , and R ² include a pyridyl group, an imidazolyl group, a benzimidazolyl group, a furyl group, and a thienyl group. Of these, a pyridyl group is preferred.

When ^R0 , ^R1 , ^R2 , ^Y1 , or ^Y2 has a substituent, examples of the substituent include an alkoxy group, a halogen atom, a hydroxyl group, a nitro group, an amino group, an acyl group, etc. When the heterocyclic group has a substituent, examples of the substituent include an alkyl group in addition to the above.

In terms of ease of synthesis, R ⁰ and R ¹ in the above (1) are preferably a hydrogen atom, a cyano group, a monovalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, an acetyl group, or -COOY ^1, and more preferably a hydrogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, a cyclohexyl group, a phenyl group, or -COOY ³ (wherein Y ³ is an alkyl group having 1 to 6 carbon atoms, a cyclohexyl group, or a phenyl group).
From the viewpoint of enhancing the releasability of the carbon to which R ⁰ , R ¹ and R ² are bonded, at least one of R ⁰ and R ¹ is preferably a methyl group.

When n is 1, ^R2 is a monovalent hydrocarbon group which may have a substituent, a monovalent heterocyclic group which may have a substituent, an acetyl group, or ^-COOY2 . Of these, ^R2 is preferably an alkyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 3 to 20 carbon atoms which may have a substituent, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, an acetyl group, a pyridyl group, or ^-COOY2 , and more preferably an alkyl group having 1 to 6 carbon atoms, a phenyl group, an acetyl group, a pyridyl group, or ^-COOY4 (wherein ^Y4 is an alkyl group having 1 to 6 carbon atoms, a cyclohexyl group, or a phenyl group).

（式中、Ｒ^３はそれぞれ独立して炭素数２～６の直鎖状又は分岐状のアルキレン基であり、ｒはそれぞれ独立して０～３の整数である。） When n is 2 or more, ^R2 is an n-valent group that is bonded via an ester bond to the carbon atom to which ^R0 and ^R1 are bonded, and has a chain hydrocarbon structure of 1 to 20 carbon atoms, the remaining portion of which may have an ether bond. The n-valent group is preferably saturated, and specifically, a group represented by the following formula is preferred.

(In the formula, each ^R3 is independently a linear or branched alkylene group having 2 to 6 carbon atoms, and each r is independently an integer of 0 to 3.)

X is an alkyl group or a monovalent electron-withdrawing group. The alkyl group represented by X may be linear or branched. Specific examples of the alkyl group include the same groups as those exemplified as the alkyl groups represented by R ¹ , R ² , Y ¹ , and Y ^2. Among the above, a linear or branched alkyl group having 1 to 10 carbon atoms is preferred, and an isopropyl group is more preferred.
Examples of the electron-withdrawing group include a nitro group, a cyano group, a halogen atom, a halogenated alkyl group (for example, a trifluoromethyl group), an acetyl group, a carboxyl group, and a sulfonic acid group.
Of the above, X is preferably an isopropyl group or a nitro group, in terms of increasing the ability to remove the carbon to which R ⁰ , R ¹ and R ² in formula (1) are bonded, ease of availability of raw materials, and ease of synthesis.
m is preferably 0 to 2, and more preferably 0 or 1.
In terms of availability of raw materials and ease of synthesis, n is preferably 1 to 4, and more preferably 1 or 2.

Specific examples of the compound represented by the above formula (1) (tropolone derivative) include compounds represented by the following formulas.

<Method of producing tropolone derivative>
The method for producing a tropolone derivative is not particularly limited, and the tropolone derivative may be produced appropriately based on the structure of each tropolone derivative. For example, a method for producing a compound represented by the above formula (1) may include a method of reacting (specifically, a nucleophilic reaction) a compound having a tropolone skeleton with a halide (hereinafter also referred to as "halide (X)") having a structure corresponding to "-C( _CH3 )( ^R1 )(R2)" in the above formula ( ¹ ).

Compounds having a tropolone skeleton that can be used in the above reaction include tropolone and hinokitiol.

As the halide (X), a compound corresponding to the number of n in the above formula (1) can be used. For example, when producing a compound in which n is 1 in the above formula (1), a compound represented by the following formula (2-1) can be used as the halide (X). Furthermore, when producing a compound in which n is 2 or more in the above formula (1), a compound represented by the following formula (2-2) can be used as the halide (X).
Z-C(CH ₃ )(R ¹ )(R ² ) (2-1)
[Z-C(CH ₃ )(R ¹ )] _n -R ² (2-2)
Here, Z is a halogen atom, and ^R1 and ^R2 are respectively defined as ^R1 and ^R2 in the above formula (1). Z is preferably a chlorine atom, a bromine atom or an iodine atom, and more preferably a chlorine atom or a bromine atom, in terms of high reactivity.

In the above reaction, the ratio of the compound having a tropolone skeleton to the halide (X) can be appropriately set according to the number n in the above formula (1). For example, when obtaining a compound in which n is 1 in the above formula (1), the ratio of the compound having a tropolone skeleton to the halide (X) is preferably 0.2 to 5.0 mol, and more preferably 0.4 to 4.0 mol, of the halide (X) per 1 mol of the compound having a tropolone skeleton.

The reaction between the compound having a tropolone skeleton and the halide (X) is preferably carried out in a solvent. The solvent used is preferably an organic solvent that does not react with the compound having a tropolone skeleton and the halide (X), and specific examples include acetonitrile, acetone, ethyl acetate, tert-butyl methyl ether, diethyl ether, tetrahydrofuran, 1,4-dioxane, etc. The solvent may be used alone or in combination of two or more. The amount of the solvent used may be set appropriately, but from the viewpoint of carrying out the reaction efficiently, it can be set to, for example, 5 to 60 mass %.

The reaction between the compound having a tropolone skeleton and the halide (X) may be carried out in the presence of a base to promote the reaction. The base may be either an organic base or an inorganic base, or an organic base and an inorganic base may be used in combination.

Specific examples of the base include hydroxides of alkali metals such as lithium hydroxide, sodium hydroxide, potassium hydroxide, and cesium hydroxide; hydroxides of alkaline earth metals such as magnesium hydroxide and calcium hydroxide; chlorides of alkali metals such as lithium chloride, sodium chloride, and potassium chloride; chlorides of alkaline earth metals such as magnesium chloride and calcium chloride; alkoxides of alkali metals such as lithium methoxide, lithium ethoxide, lithium isopropoxide, sodium methoxide, sodium ethoxide, sodium isopropoxide, potassium methoxide, and potassium tert-butoxide; alkoxides of alkaline earth metals such as magnesium ethoxide; carbonates of alkali metals such as lithium carbonate, sodium carbonate, and potassium carbonate; carbonates of alkaline earth metals such as magnesium carbonate and calcium carbonate; hydrogen carbonates of alkali metals such as sodium hydrogen carbonate and potassium hydrogen carbonate; hydrogen carbonates of alkaline earth metals such as calcium hydrogen carbonate and barium hydrogen carbonate;
Examples of the oxides include alkali metals such as lithium oxide, sodium oxide, and potassium oxide; oxides of alkaline earth metals such as magnesium oxide, calcium oxide, and barium oxide; primary amines such as butylamine, hexadecylamine, ethanolamine, ethylenediamine, hexamethylenediamine, and aniline; secondary amines such as dibutylamine, dicyclohexylamine, and diethanolamine; tertiary amines such as tributylamine, tetramethylethylenediamine, tetramethylhexamethylenediamine, triethanolamine, N,N-diethylaniline, and N-methylmorpholine; quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, tetramethylammonium bromide, tetraethylammonium bromide, tetrabutylammonium bromide, tetramethylammonium chloride, tetraethylammonium chloride, and tetrabutylammonium chloride; nitrogen-containing aromatic heterocyclic compounds such as pyridine, quinoline, and pyridine hydrochloride; ammonia, ammonium carbonate, ammonium hydrogencarbonate, tetramethylammonium hydroxide, and tetraethylammonium hydroxide. As the base, one of these may be used alone, or two or more of them may be used in combination.

When a base is used in the above reaction, the amount of base used is, for example, 0.1 to 10 mol, preferably 0.2 to 5 mol, per 1 mol of halide (X).

The reaction temperature and reaction time in the reaction between the compound having a tropolone skeleton and the halide (X) can be adjusted as appropriate depending on the raw materials used, etc. The reaction temperature is, for example, 0°C to 200°C, and preferably 10 to 150°C. If the reaction temperature is too low, the time required to obtain the target product will be long, and productivity will tend to be poor. On the other hand, if the reaction temperature is too high, decomposition and side reactions will tend to occur more easily. The reaction time is, for example, 30 minutes to 100 hours, and may be 1 to 50 hours. The reaction may be carried out with stirring to make the reaction proceed efficiently. The reaction is usually carried out under normal pressure, but may also be carried out under increased or reduced pressure.

The desired tropolone derivative can be obtained by the above reaction. When isolating and/or purifying the tropolone derivative obtained by the reaction, a known method can be used for the isolation and/or purification process.

<Vinyl Monomer>
In the living radical polymerization using a tropolone derivative, the vinyl monomer to be used is not particularly limited as long as it is a radically polymerizable monomer. Examples of the vinyl monomer to be used in the manufacturing method of the present disclosure include (meth)acrylic acid alkyl ester compounds, (meth)acrylic acid aliphatic cyclic ester compounds, (meth)acrylic acid aromatic ester compounds, (meth)acrylic acid alkoxyalkyl ester compounds, (meth)acrylic acid hydroxyalkyl ester compounds, (meth)acrylic compounds having a polyoxyalkylene structure, vinyl compounds having a heterocyclic structure, amino group-containing vinyl compounds, amide group-containing vinyl compounds, cyano group-containing vinyl compounds, nitrile group-containing vinyl compounds, aromatic vinyl compounds, maleimide compounds, unsaturated carboxylic acids and unsaturated acid anhydrides.

Further specific examples of vinyl monomers are as follows. Specific examples of (meth)acrylic acid alkyl ester compounds include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, nonadecyl (meth)acrylate, and icosyl (meth)acrylate.

Specific examples of aliphatic cyclic ester compounds of (meth)acrylic acid include cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, cyclododecyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentanyl (meth)acrylate.

Specific examples of aromatic ester compounds of (meth)acrylic acid include phenyl (meth)acrylate, benzyl (meth)acrylate, phenoxymethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, and 3-phenoxypropyl (meth)acrylate.

Specific examples of (meth)acrylic acid alkoxyalkyl ester compounds include methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, n-propoxyethyl (meth)acrylate, n-butoxyethyl (meth)acrylate, methoxypropyl (meth)acrylate, ethoxypropyl (meth)acrylate, n-propoxypropyl (meth)acrylate, n-butoxypropyl (meth)acrylate, methoxybutyl (meth)acrylate, ethoxybutyl (meth)acrylate, n-propoxybutyl (meth)acrylate, and n-butoxybutyl (meth)acrylate.

Specific examples of (meth)acrylic acid hydroxyalkyl ester compounds include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate.

Specific examples of (meth)acrylic compounds having a polyoxyalkylene structure include polyoxyethylene (meth)acrylate, polyoxypropylene (meth)acrylate, polyoxybutylene (meth)acrylate, polyoxyethylene-polyoxypropylene (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, lauroxypolyethylene glycol (meth)acrylate, stearoxypolyethylene glycol (meth)acrylate, octoxypolyethylene glycol polypropylene glycol (meth)acrylate, nonylphenoxypolypropylene glycol (meth)acrylate, and phenoxypolyethylene glycol polypropylene glycol (meth)acrylate.

Examples of vinyl compounds having a heterocyclic structure include glycidyl (meth)acrylate, (3,4-epoxycyclohexyl)methyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate.

Examples of amino group-containing vinyl compounds include dimethylaminomethyl (meth)acrylate, diethylaminomethyl (meth)acrylate, 2-dimethylaminoethyl (meth)acrylate, 2-diethylaminoethyl (meth)acrylate, 2-(di-n-propylamino)ethyl (meth)acrylate, 2-dimethylaminopropyl (meth)acrylate, 2-diethylaminopropyl (meth)acrylate, 2-(di-n-propylamino)propyl (meth)acrylate, 3-dimethylaminopropyl (meth)acrylate, 3-diethylaminopropyl (meth)acrylate, 3-(di-n-propylamino)propyl (meth)acrylate, etc.

Examples of vinyl compounds containing an amide group include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, and N-methylol(meth)acrylamide.

Examples of cyano group-containing vinyl compounds include cyanomethyl (meth)acrylate, 1-cyanoethyl (meth)acrylate, 2-cyanoethyl (meth)acrylate, 1-cyanopropyl (meth)acrylate, 2-cyanopropyl (meth)acrylate, 3-cyanopropyl (meth)acrylate, 4-cyanobutyl (meth)acrylate, 6-cyanohexyl (meth)acrylate, 2-ethyl-6-cyanohexyl (meth)acrylate, and 8-cyanooctyl (meth)acrylate.

Examples of nitrile group-containing vinyl compounds include (meth)acrylonitrile, ethacrylonitrile, α-ethylacrylonitrile, α-isopropylacrylonitrile, α-chloroacrylonitrile, α-fluoroacrylonitrile, etc.

Aromatic vinyl compounds include styrene, α-methylstyrene, β-methylstyrene, vinylxylene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, p-n-butylstyrene, p-isobutylstyrene, p-t-butylstyrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, p-hydroxystyrene, m-hydroxystyrene, o-hydroxystyrene, p-isopropenylphenol, m-isopropenylphenol, o-isopropenylphenol, o-vinylbenzoic acid, m-vinylbenzoic acid, p-vinylbenzoic acid, divinylbenzene, and vinylnaphthalene.

Examples of maleimide compounds include maleimide and N-substituted maleimide compounds. Examples of N-substituted maleimide compounds include N-alkyl-substituted maleimides such as N-methylmaleimide, N-ethylmaleimide, N-n-propylmaleimide, N-isopropylmaleimide, N-n-butylmaleimide, N-isobutylmaleimide, and N-tert-butylmaleimide; N-cycloalkyl-substituted maleimides such as N-cyclopentylmaleimide and N-cyclohexylmaleimide; N-aralkyl-substituted maleimides such as N-benzylmaleimide; and N-aryl-substituted maleimides such as N-phenylmaleimide, N-(4-hydroxyphenyl)maleimide, N-(4-acetylphenyl)maleimide, and N-(4-methoxyphenyl)maleimide.

Specific examples of unsaturated carboxylic acids include (meth)acrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, citraconic acid, cinnamic acid, succinic acid monohydroxyethyl (meth)acrylate, ω-carboxy-caprolactone mono(meth)acrylate, β-carboxyethyl (meth)acrylate, and 4-carboxystyrene.
Specific examples of the unsaturated acid anhydride include maleic anhydride, itaconic anhydride, and citraconic anhydride.

The vinyl monomer used in the polymerization preferably contains at least one selected from the group consisting of (meth)acrylic acid alkyl ester compounds, (meth)acrylic acid aliphatic cyclic ester compounds, (meth)acrylic acid aromatic ester compounds, (meth)acrylic acid alkoxyalkyl ester compounds, aromatic vinyl compounds, maleimide compounds, unsaturated carboxylic acids, (meth)acrylonitrile, and (meth)acrylamide.

In the above polymerization, the amount of the tropolone derivative used may be adjusted as appropriate depending on the molecular weight and molecular weight distribution of the desired living radical polymer. The amount of the tropolone derivative used is preferably an amount such that the amount of monomer used in the polymerization is 5 to 10,000 mol, and more preferably 30 to 5,000 mol, per 1 mol of the tropolone derivative. Note that one type of tropolone derivative may be used alone, or two or more types may be used in combination.

　Living radical polymerization using tropolone derivatives may be carried out without a solvent or in a solvent. As the solvent, any solvent generally used in radical polymerization may be used as appropriate. Specific examples of solvents include aromatic hydrocarbons such as benzene, toluene, and xylene; alcohols such as methanol, ethanol, isopropanol, n-butanol, and 1-methoxy-2-propanol; N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), acetone, chloroform, carbon tetrachloride, tetrahydrofuran (THF), dioxane, ethyl acetate, trifluoromethylbenzene, ethyl cellosolve, and butyl cellosolve. In addition, an aqueous solvent may be used as the solvent. Examples of the aqueous solvent include water or a mixture of water and alcohols.

When a solvent is used in the polymerization, the amount of the solvent used may be adjusted as appropriate, but may be, for example, 1 to 1,000 parts by mass, or 5 to 200 parts by mass, per 100 parts by mass of the total amount of vinyl monomers used in the polymerization. Note that one type of solvent may be used alone, or two or more types may be used in combination.

The above polymerization is initiated and progresses by irradiating a reaction system containing a vinyl monomer and a tropolone derivative with active energy rays or applying heat.

Examples of active energy rays include ultraviolet rays, visible light, and electron beams. Of these, ultraviolet rays are preferred. The irradiation energy can be set appropriately depending on the type of active energy rays, the type and concentration of the monomer, the type and concentration of the tropolone derivative, etc.

For example, when ultraviolet light is used as the active energy ray, the wavelength is, for example, 250 to 420 nm. Examples of ultraviolet light irradiation devices include high-pressure mercury lamps, metal halide lamps, ultraviolet electrodeless lamps, and ultraviolet light-emitting diodes (UV-LEDs). The integrated light amount is preferably 0.5 J/cm ² or more, more preferably 1.0 J/cm ² or more, and even more preferably 1.5 J/cm ² or more. In addition, the upper limit of the integrated light amount is preferably 250 J/cm ² or less, and more preferably 200 J/cm ² or less, in order to minimize the influence on each component in the reaction system and to reduce energy.

The illuminance and irradiation time of the ultraviolet light can be appropriately set so that the integrated light amount is the desired amount. For example, the illuminance is preferably 1 mW/cm2 or ^more , more preferably 2 mW/ ^cm2 or more. The upper limit of the illuminance is preferably 100 mW/cm2 or ^less , more preferably 80 mW/ ^cm2 or less. The irradiation time is, for example, 10 minutes to 12 hours.

When polymerization is initiated by applying heat, the heating temperature is, for example, 30 to 150°C, and preferably 50 to 120°C. The heating time is, for example, 10 minutes to 12 hours. When polymerization is initiated by applying heat, a polymerization initiator may be used. As the polymerization initiator, known radical polymerization initiators such as azo compounds, organic peroxides, and persulfates can be used. Of these, azo compounds are preferred because they are safe and easy to handle, and are less likely to cause side reactions during radical polymerization.

Specific examples of polymerization initiators include 2,2-azobis(isovaleronitrile) (AIVN), 2,2-azobis(isobutyronitrile) (AIBN), 2,2-azobis(2-methylbutyronitrile) (AMBN), 2,2-azobis(2,4-dimethylvaleronitrile) (ADVN), 1,1-azobis(1-cyclohexanecarbonitrile) (ACHN), dimethyl-2,2-azobisisobutyrate (MAIB), 4,4-azobis(4-cyanovaleric acid) (ACVA), 1,1-azobis(1-acetoxy-1-phenylethane), 2,2-azobis(2-methylbutyronitrile) (AMBN), 2,2-azobis(2,4-dimethylvaleronitrile) (ADVN), butyl amide), 2,2-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2-azobis(2-methylamidinopropane) dihydrochloride, 2,2-azobis[2-(2-imidazolin-2-yl)propane], 2,2-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 2,2-azobis(2,4,4-trimethylpentane), 2-cyano-2-propylazoformamide, 2,2-azobis(N-butyl-2-methylpropionamide), 2,2-azobis(N-cyclohexyl-2-methylpropionamide), etc. As the polymerization initiator, one of these may be used alone, or two or more may be used in combination.

When a polymerization initiator is used in the above polymerization, the amount of polymerization initiator used may be adjusted appropriately depending on the molecular weight and molecular weight distribution of the desired living radical polymer. In order to stably carry out the polymerization reaction and obtain a living radical polymer with a smaller molecular weight distribution, it is preferable to use 0.01 to 0.6 mol of polymerization initiator per 1 mol of living radical polymerization control agent used in the reaction, and more preferably 0.05 to 0.2 mol.

In addition, in the method of polymerizing vinyl monomers using a tropolone derivative as a radical polymerization inhibitor, the method of initiating/progressing polymerization by irradiation with active energy rays allows the living radical polymerization reaction to be carried out without using a polymerization initiator, and is useful in that it can minimize the inclusion of impurities in the living radical polymer after recovery.

The manufacturing process for living radical polymers may be either batch or continuous. In the case of batch processes, when the reaction rate is fast, a semi-batch process in which monomers are fed is preferred in order to make it easier to control the temperature. In the case of continuous processes, tubular, tower, continuous stirred tank (CSTR) and combinations of these may be used. Of these, tubular and tower processes are preferred because they can narrow the molecular weight distribution of the resulting polymer.

In the living radical polymerization using a tropolone derivative, a homopolymer may be obtained by polymerization using one type of monomer. Alternatively, a copolymer may be obtained by using two or more types of monomers in the living radical polymerization. The type of copolymer is not particularly limited, and examples include random copolymers, block copolymers, alternating copolymers, and graft copolymers.

For example, when a block copolymer having a first polymer block and a second polymer block is obtained using a tropolone derivative, the block copolymer can be obtained by a method including the following first and second steps.
First step: A step of obtaining a first polymer block by polymerizing a monomer constituting a first polymer block in the presence of the tropolone derivative represented by the above formula (1). Second step: A step of polymerizing a monomer constituting a second polymer block in the presence of the first polymer block.

As an example, when a linear triblock copolymer consisting of polymer block M/polymer block N/polymer block M is obtained by a living radical polymerization method, a tropolone derivative in which n in the above formula (1) is 1 is used as a living polymerization control agent, and the polymerization for obtaining each block is carried out sequentially to obtain the desired block copolymer. In this case, in the first step, the monomer constituting polymer block M is polymerized to obtain polymer block M, and then in the second step, the monomer constituting polymer block N is polymerized to obtain polymer block N. Furthermore, in the third step, the monomer constituting polymer block M is polymerized. In this way, a linear triblock copolymer consisting of polymer block M/polymer block N/polymer block M can be obtained. In addition, by further sequentially carrying out the fourth step, the fifth step, etc., a multiblock copolymer having four or more blocks can also be obtained.

In addition, when a linear triblock copolymer consisting of polymer block M/polymer block N/polymer block M is obtained by a living radical polymerization method, the desired block copolymer can be obtained more efficiently by using a tropolone derivative in which n in the above formula (1) is 2 as a living polymerization control agent and performing polymerization to obtain each block. In this case, first, in the first step, a monomer constituting the polymer block N located in the center of the desired block copolymer is polymerized to obtain polymer block N. Then, in the second step, a monomer constituting the polymer block M is polymerized to obtain polymer block M. In this way, a triblock copolymer consisting of polymer block M/polymer block N/polymer block M can be obtained. Furthermore, by successively performing the third step, the fourth step, etc., a multiblock copolymer having five or more blocks can be obtained. According to this method, the polymer production process can be simplified compared to the case where each block is produced by sequentially polymerizing it. In addition, by using a tropolone derivative in which n is 2 in the above formula (1) as a living polymerization control agent, it is also possible to obtain a telechelic polymer having X in the above formula (1) or a reactive group derived from X (e.g., a hydroxyl group, an epoxy group, a carboxyl group, a (meth)acryloyl group, a sulfonic acid group, etc.) at both ends.

In addition, by polymerizing a monomer using a tropolone derivative in which n in the above formula (1) is 3 or more as a living polymerization inhibitor, a star-shaped homopolymer or block copolymer having a number of branched chains corresponding to n can be obtained.

The reaction temperature and reaction time of the living radical polymerization reaction can be adjusted appropriately according to the molecular weight and molecular weight distribution of the desired living radical polymer. The reaction temperature is, for example, -10°C to 120°C, and preferably 0 to 100°C. If the reaction temperature is too low, the time required for polymerization will be too long, which will tend to result in poor productivity, and the initiation reaction will tend to be slow, which will tend to lead to a broad molecular weight distribution. On the other hand, if the reaction temperature is too high, the polymerization controllability will decrease, which will tend to lead to a broad molecular weight distribution and to the occurrence of side reactions. The reaction time is, for example, 10 minutes to 100 hours, and preferably 30 minutes to 50 hours. From the viewpoint of efficiently progressing the reaction, the polymerization may be carried out while stirring the reaction system. The polymerization is usually carried out under normal pressure, but may also be carried out under pressure or reduced pressure.

The desired living radical polymer can be obtained by such a polymerization reaction. When isolating and/or purifying the living radical polymer obtained by the polymerization reaction, known methods can be used for such treatment.

The molecular weight of the living radical polymer obtained by the above polymerization can be adjusted as appropriate by adjusting the reaction temperature, reaction time, amount of tropolone derivative used, amount of monomer used, etc. According to the method of radically polymerizing a monomer in the presence of a tropolone derivative, for example, a living radical polymer having a number average molecular weight (Mn) in the range of 500 to 2,000,000 can be obtained. According to this method, a living radical polymer having an Mn in the range of 1,000 to 1,000,000 can be obtained, and is particularly suitable as a method for obtaining a living radical polymer having an Mn in the range of 2,000 to 100,000.

Furthermore, according to the manufacturing method of the present disclosure in which a monomer is radically polymerized in the presence of a tropolone derivative, a living radical polymer can be obtained having a sufficiently narrow molecular weight distribution (Mw/Mn) of 1.0 to 2.5, which is expressed as the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn). The molecular weight distribution of the living radical polymer obtained by the above polymerization is preferably 2.2 or less, and more preferably 2.0 or less. In this specification, the Mw and Mn of the polymer are standard polystyrene equivalent values obtained using gel permeation chromatography (GPC).

Although this disclosure is not limited thereto, it is believed that controlled polymerization proceeds via a reversible chain transfer reaction by radically polymerizing a vinyl monomer in the presence of a tropolone derivative. For example, it is presumed that in the case of a thermal initiation type, the reaction proceeds according to the following scheme A, and in the case of a photoinitiation type, the reaction proceeds according to the following scheme B. In schemes A and B, R ⁰ , R ¹ , R ² , X, n, and m are the same as R ¹ , R ² , n, and m in the above formula (1). I represents a polymerization initiator, M represents a monomer, and Pn represents a polymer chain.

According to the manufacturing method of the present disclosure described above, by radically polymerizing a vinyl monomer in the presence of a tropolone derivative, it is possible to obtain a polymer with precisely controlled molecular weight and molecular weight distribution while suppressing coloration and odor. Therefore, the tropolone derivative is particularly useful as a living radical polymerization control agent.

Below, the present disclosure will be specifically explained based on examples. Note that the present disclosure is not limited to these examples. In the following, "parts" and "%" mean "parts by mass" and "% by mass", respectively, unless otherwise specified.

　The molecular weight measurement of the vinyl polymer obtained by living radical polymerization using the tropolone derivative obtained in each example is described below.

<Molecular weight measurement>
The vinyl polymer thus obtained was subjected to gel permeation chromatography (GPC) under the conditions described below to obtain the number average molecular weight (Mn) and weight average molecular weight (Mw) in terms of polystyrene. The molecular weight distribution (Mw/Mn) was calculated from the obtained values.
Measurement conditions: Column: Tosoh TSKgel GMH _HR -M x 3 Solvent: Tetrahydrofuran Temperature: 40°C
Detector: RI, UV (322 nm)
Flow rate: 1.0mL/min

<Synthesis of Tropolone Derivatives>
Example 1 Synthesis of MDTA
The compound represented by the following formula (hereinafter referred to as "MDTA") was synthesized by the following procedure.

A stirrer was placed in a 300 mL two-necked eggplant flask, and 19.84 g (140 mmol) of potassium carbonate, 8.01 g (65.6 mmol) of tropolone, 4.20 g (20.0 mmol) of tetraethylammonium bromide, and 160 mL of acetonitrile were added and stirred at room temperature. Then, 17 mL (131 mmol) of methyl α-bromoisobutyrate was gradually added dropwise from the dropping funnel. After the dropping, the mixture was reacted at 90° C. for 24 hours. After the reaction, the acetonitrile was removed by evaporation, and the mixture was dissolved in ethyl acetate, and then washed with an aqueous sodium hydroxide solution to remove potassium carbonate, tetraethylammonium bromide, and unreacted tropolone. After preliminary drying over sodium sulfate, the ethyl acetate was removed by evaporation. The mixture was purified by open column chromatography [amino-type silica gel (NH-DM1020, Fuji Silysia Chemical)] using a 1:2 (volume ratio) mixed solvent of n-hexane and ethyl acetate (Rf=0.55). The target compound (MDTA) was obtained in a yield of 32%. The synthesis results were confirmed by ¹ H-NMR, ¹³ C-NMR, FT-IR, and DART-MS. The results are shown in FIG.

In FIG. 1, (a) shows ^{the 1} H-NMR spectrum, (b) shows the ¹³ C-NMR spectrum, (c) shows the DART-MS spectrum, and (d) shows the FT-IR spectrum (the same applies to FIGS. 2, 4, and 5).

[Example 2] (Synthesis of MDITA)
The compound represented by the following formula (hereinafter referred to as "MDITA") was synthesized by the following procedure.

A stirrer was placed in a 300 mL two-necked eggplant flask, and 19.84 g (140 mmol) of potassium carbonate, 10.77 g (65.6 mmol) of hinokitiol, and 200 ml of acetonitrile were added and stirred at room temperature. Next, 17 mL (131 mmol) of methyl α-bromoisobutyrate was gradually added dropwise from the dropping funnel. After the addition, the mixture was reacted at 90° C. for 24 hours. After the reaction, the acetonitrile was removed by evaporation, and the mixture was dissolved in ethyl acetate and washed with an aqueous sodium hydroxide solution to remove potassium carbonate, tetraethylammonium bromide, and unreacted hinokitiol. After preliminary drying over sodium sulfate, the ethyl acetate was removed by evaporation. The mixture was purified by open column chromatography [amino-type silica gel (NH-DM1020, Fuji Silysia Chemical)] using a 1:2 (volume ratio) mixed solvent of n-hexane and ethyl acetate (Rf=0.58). The target compound (MDITA (including isomers)) was obtained in a yield of 88%. The synthesis results were confirmed by ¹ H-NMR, ¹³ C-NMR, FT-IR, and DART-MS. The results are shown in FIG.

[Example 3] (Synthesis of NO ₂ -MDTA)
The compound represented by the following formula (hereinafter referred to as "NO ₂ -MDTA") was synthesized by the following procedure.

A stirrer was placed in a 50 mL two-necked eggplant flask, 2.20 g (9.90 mmol) of MDTA, 0.42 g (1.98 mmol) of tetraethylammonium bromide, 16 g of acetonitrile, 16 g of water, and 1.44 g of concentrated nitric acid (equivalent to 13.71 mmol as HNO ₃ ) were placed, and the mixture was reacted for 24 hours while stirring at room temperature. After the reaction, the mixture was dissolved in dichloromethane, and then thoroughly washed with sodium bicarbonate water and ion-exchanged water to remove tetraethylammonium bromide and the like. The organic phase was removed by evaporation. The target compound (NO ₂ -MDTA) was obtained with a yield of 51%. The synthesis results were confirmed by ¹ H-NMR, ¹³ C-NMR, and FT-IR. The results are shown in FIG. 3.

In FIG. 3, (a) shows ^{the 1} H-NMR spectrum, (b) shows the ¹³ C-NMR spectrum, and (c) shows the FT-IR spectrum.

Example 4 Synthesis of MMTA
The compound represented by the following formula (hereinafter referred to as "MMTA") was synthesized by the following procedure.

A stirrer was placed in a 300 mL two-necked eggplant flask, and 19.40 g (140 mmol) of potassium carbonate, 8.00 g (65.5 mmol) of tropolone, and 160 ml of acetonitrile were added and stirred at room temperature. Next, 14.59 ml (131 mmol) of methyl 2-bromopropionate was gradually added dropwise from the dropping funnel. After the dropwise addition, the mixture was reacted at 90° C. for 24 hours. After the reaction, the acetonitrile was removed by evaporation, and the mixture was dissolved in ethyl acetate, and then washed with an aqueous sodium hydroxide solution to remove potassium carbonate and unreacted tropolone. After preliminary drying over sodium sulfate, the ethyl acetate was removed by evaporation. The mixture was purified by open column chromatography [amino-type silica gel (NH-DM1020, Fuji Silysia Chemical)] using a 1:2 (volume ratio) mixed solvent of n-hexane and ethyl acetate (Rf=0.47). The target compound (MMTA) was obtained in a yield of 37%. The synthesis results were confirmed by ¹ H-NMR, ¹³ C-NMR, FT-IR and DART-MS, and the results are shown in FIG.

[Example 5] (Synthesis of MBZTA)
The compound represented by the following formula (hereinafter referred to as "MBZTA") was synthesized by the following procedure.

A stirrer was placed in a 300 mL two-necked eggplant flask, and 19.40 g (140 mmol) of potassium carbonate, 8.00 g (65.5 mmol) of tropolone, 4.14 g (19.7 mmol) of tetraethylammonium bromide, and 160 ml of acetonitrile were added and stirred at room temperature. Next, 17.4 mL (131 mmol) of (1-chloroethyl)benzene was gradually added dropwise from the dropping funnel. After the dropwise addition, the mixture was reacted at 90° C. for 24 hours. After the reaction, the acetonitrile was removed by evaporation, and the mixture was dissolved in ethyl acetate and washed with an aqueous sodium hydroxide solution to remove potassium carbonate, tetraethylammonium bromide, and unreacted tropolone. After preliminary drying over sodium sulfate, the ethyl acetate was removed by evaporation. The mixture was purified by open column chromatography [amino-type silica gel (NH-DM1020, Fuji Silysia Chemical)] using a 1:2 (volume ratio) mixed solvent of n-hexane and ethyl acetate (Rf=0.44). The target compound (MBZTA) was obtained in a yield of 28%. The synthesis results were confirmed by ¹ H-NMR, ¹³ C-NMR, FT-IR, and DART-MS. The results are shown in FIG.

[Example 6] (Synthesis of bis-MDTA)
The compound represented by the following formula (hereinafter referred to as "bis-MDTA") was synthesized by the following procedure.

A stirrer was placed in a 300 mL two-necked eggplant flask, and 7.68 g (55.6 mmol) of potassium carbonate, 3.39 g (27.8 mmol) of tropolone, 0.88 g (4.2 mmol) of tetraethylammonium bromide, and 40 ml of acetonitrile were added and stirred at room temperature. Next, a solution of 5.0 g (13.9 mmol) of ethylene bis(2-bromoisobutyrate) dissolved in 16 mL of acetonitrile was added to the dropping funnel, and this was gradually dropped into the eggplant flask. After dropping, the reaction was carried out at 90° C. for 24 hours. After the reaction, the acetonitrile was removed by evaporation, and the mixture was dissolved in ethyl acetate and washed with an aqueous sodium hydroxide solution to remove potassium carbonate, tetraethylammonium bromide, and unreacted tropolone. After preliminary drying over sodium sulfate, the ethyl acetate was removed by evaporation. The product was purified by open column chromatography [amino-type silica gel (NH-DM1020, Fuji Silysia Chemical)] using a 1:2 (volume ratio) mixed solvent of n-hexane and ethyl acetate (Rf=0.18). The target compound (bis-MDTA) was obtained in a 9% yield. The synthesis results were confirmed by ¹ H-NMR, ¹³ C-NMR, and DART-MS. The results are shown in FIG. 6. In FIG. 6, (a) shows ^{the 1} H-NMR spectrum, (b) shows the ¹³ C-NMR spectrum, and (c) shows the DART-MS.

<Production of vinyl polymer>
[Example 7] (EA with MDTA via MFlamp)
A stirrer was placed in the test tube, and 0.017 g of MDTA, 1.5 g of ethyl acrylate (hereinafter referred to as "EA"), and 3.5 g of toluene were added and dissolved. Next, freeze-degassing was performed three times, and then the test tube was sealed and irradiated with light from a metal halide lamp (LS-140UV manufactured by Sumita Optical Glass Co., Ltd., wavelength 290-420 nm, illuminance 21 mW/cm ² (365 nm)) at room temperature for 4 hours. During this time, the reaction solution was extracted after 15 minutes, 30 minutes, 1 hour, 2 hours, and 4 hours, and the extracted solution was exposed to air to terminate the polymerization, and ¹ H-NMR analysis and GPC analysis were performed. As a result, it was confirmed that the produced polymer changed to a high molecular weight with the passage of time and an increase in the reaction rate of the monomer, and the polymerization proceeded in a living manner (see FIG. 7).

In Figure 7, (a) shows the relationship between time (horizontal axis, Time (h)) and monomer reaction rate (vertical axis, Conv. (%)), (b) shows the relationship between monomer conversion rate (horizontal axis) and polymer number average molecular weight (vertical axis), and (c) shows the change in number average molecular weight and molecular weight distribution over time and monomer reaction rate (same for Figures 8 to 10 and 13 to 18).

[Example 8] (St with MDTA via MFlamp)
A stirrer was placed in the test tube, and 0.027 g of MDTA, 2.5 g of styrene (hereinafter referred to as "St"), and 2.5 g of toluene were added and dissolved. Next, freeze-degassing was performed three times, and then the test tube was sealed and irradiated with light from a metal halide lamp at room temperature for 24 hours. During this time, the reaction solution was extracted after 1, 2, 4, 8, and 24 hours, and the extracted solution was exposed to air to terminate the polymerization, and ¹ H-NMR analysis and GPC analysis were performed. As a result, it was confirmed that the produced polymer changed to a high molecular weight with the passage of time and an increase in the reaction rate of the monomer, and the polymerization proceeded in a living manner (see FIG. 8).

[Example 9] (VAc with MDTA via MFlamp)
A stirrer was placed in the test tube, and 0.032 g of MDTA, 2.5 g of vinyl acetate (hereinafter referred to as "VAc"), and 2.5 g of methanol were added and dissolved. Next, freeze-degassing was performed three times, and then the test tube was sealed and irradiated with light from a metal halide lamp at room temperature for 24 hours. During this time, the reaction solution was extracted after 2 hours, 5 hours, 8 hours, 13 hours, and 24 hours, and the extracted solution was exposed to air to terminate the polymerization, and ¹ H-NMR analysis and GPC analysis were performed. As a result, it was confirmed that the produced polymer changed to a high molecular weight with the passage of time and an increase in the reaction rate of the monomer, and the polymerization proceeded in a living manner (see FIG. 9).

[Example 10] (EA with MDTA via UV-LED (365nm))
A stirrer was placed in the test tube, and 0.017 g of MDTA, 1.5 g of EA, and 3.5 g of toluene were added and dissolved. Then, freeze-degassing was performed three times, and the test tube was sealed, and light from a UV-LED (PER-365 manufactured by Technosigma, peak wavelength 365 nm, illuminance 7.5 mW/cm ² , hereinafter simply referred to as "UV-LED") was irradiated at room temperature for 4 hours by directly inserting the light-emitting part into the test tube. During this time, the reaction solution was extracted after 15 minutes, 30 minutes, 1 hour, 2 hours, and 4 hours, and the extracted solution was exposed to air to terminate the polymerization, and ¹ H-NMR analysis and GPC analysis were performed. As a result, it was confirmed that the produced polymer changed to a high molecular weight with the passage of time and the increase in the reaction rate of the monomer, and the polymerization proceeded in a living manner (see FIG. 10).

[Example 11] (PVAc Macro to St block via MFlamp)
A stirrer was placed in the test tube, and 0.064 g of MDTA and 5.0 g of VAc were added and dissolved. Next, freeze-degassing was performed three times, and then the test tube was sealed and irradiated with light from a metal halide lamp at room temperature. After 49 hours had elapsed from the start of the reaction, the polymerization was terminated by exposure to air, and ¹ H-NMR analysis and GPC analysis were performed. As a result, the monomer conversion rate was 13%, and the Mn of the obtained polyvinyl acetate (hereinafter referred to as "PVAc") was 9,900 and Mw/Mn was 2.02. PVAc was dissolved in THF and then purified by reprecipitation from n-hexane.
A stirrer was placed in a test tube, and 0.031 g of PVAc, 0.25 g of St, and 0.25 g of toluene were added and dissolved. Next, freeze-degassing was performed three times, and then the test tube was sealed and irradiated with light from a metal halide lamp at room temperature. 24 hours after the start of the reaction, the polymerization was terminated by exposure to air, and ¹ H-NMR analysis and GPC analysis were performed. The conversion rate of St was 27%, and the obtained polymer changed to a higher molecular weight substance than the PVAc used with the passage of time and an increase in the reaction rate of the monomer, and it was confirmed that block copolymerization had progressed (see FIG. 11).

[Example 12] (PVAcMacro to EA block via MFlamp)
Polymerization of VAc was carried out in the same manner as in Example 11, and PVAc having the same Mn and Mw/Mn as those in Example 11 was obtained. A stirrer was placed in a test tube, and 0.025 g of PVAc, 0.20 g of EA, and 0.47 g of toluene were added and dissolved. Next, freeze-degassing was performed three times, and the test tube was sealed and irradiated with light from a metal halide lamp at room temperature. After 24 hours from the start of the reaction, the polymerization was terminated by exposure to air, and ¹ H-NMR analysis and GPC analysis were performed. The conversion rate of EA was 67%, and the obtained polymer changed to a higher molecular weight substance than the PVAc used with the passage of time and the increase in the reaction rate of the monomer, and it was confirmed that block copolymerization had progressed (see FIG. 12).

[Example 13] (EA with MDITA via UV-LED (365nm))
A stirrer was placed in the test tube, and 0.020 g of MDITA, 1.5 g of EA, and 3.5 g of toluene were added and dissolved. Next, freeze-degassing was performed three times, and then the test tube was sealed, and UV-LED light was irradiated at room temperature for 4 hours by directly inserting the light-emitting part into the test tube. During this time, the reaction solution was extracted after 15 minutes, 30 minutes, 1 hour, 2 hours, and 4 hours, and the extracted solution was exposed to air to terminate the polymerization, and ¹ H-NMR analysis and GPC analysis were performed. As a result, it was confirmed that the produced polymer changed to a high molecular weight with the passage of time and the increase in the reaction rate of the monomer, and the polymerization proceeded in a living manner (see FIG. 13).

[Example 14] (EA with NO ₂ -MDTA via UV-LED (365nm))
A stirrer was placed in the test tube, and 0.015 g of NO ₂ -MDTA, 1.5 g of EA, and 3.5 g of toluene were added and dissolved. Next, freeze-degassing was performed three times, and then the test tube was sealed, and UV-LED light was irradiated at room temperature for 4 hours by directly inserting the light-emitting part into the test tube. During this time, the reaction solution was extracted after 15 minutes, 30 minutes, 1 hour, 2 hours, and 4 hours, and the extracted solution was exposed to air to terminate the polymerization, and ¹ H-NMR analysis and GPC analysis were performed. As a result, it was confirmed that the produced polymer changed to a high molecular weight with the passage of time and the increase in the reaction rate of the monomer, and the polymerization proceeded in a living manner (see FIG. 14).

[Example 15] (EA with MMTA via UV-LED (365nm))
A stirrer was placed in the test tube, and 0.017 g of MMTA, 1.5 g of EA, and 3.5 g of toluene were added and dissolved. Next, freeze-degassing was performed three times, and then the test tube was sealed and irradiated with UV-LED light at room temperature for 24 hours by directly inserting the light-emitting part into the test tube. During this time, the reaction solution was extracted after 15 minutes, 30 minutes, 1 hour, 2.5 hours, 4 hours, and 6 hours, and the extracted solution was exposed to air to terminate the polymerization, and ¹ H-NMR analysis and GPC analysis were performed. As a result, it was confirmed that the produced polymer changed to a high molecular weight with the passage of time and the increase in the reaction rate of the monomer, and the polymerization proceeded in a living manner (see FIG. 15).

[Example 16] (EA with MBZTP via UV-LED (365nm))
A stirrer was placed in the test tube, and 0.017 g of MBZTP, 1.5 g of EA, and 3.5 g of toluene were added and dissolved. Next, freeze-degassing was performed three times, and then the test tube was sealed and UV-LED light was irradiated at room temperature for 24 hours by directly inserting the light-emitting part into the test tube. During this time, the reaction solution was extracted after 30 minutes, 1 hour, 2 hours, 4 hours, and 6 hours, and the extracted solution was exposed to air to terminate the polymerization, and ¹ H-NMR analysis and GPC analysis were performed. As a result, it was confirmed that the produced polymer changed to a high molecular weight with the passage of time and the increase in the reaction rate of the monomer, and the polymerization proceeded in a living manner (see FIG. 16).

[Example 17] (EA with bis-MDTA via UV-LED (365nm))
A stirrer was placed in the test tube, and 0.030 g of bis-MDTA, 1.4 g of EA, and 3.2 g of toluene were added and dissolved. Next, freeze-degassing was performed three times, and then the test tube was sealed, and UV-LED light was irradiated at room temperature for 24 hours by directly inserting the light-emitting part into the test tube. During this time, the reaction solution was extracted after 15 minutes, 30 minutes, 1 hour, 2 hours, and 4 hours, and the extracted solution was exposed to air to terminate the polymerization, and ¹ H-NMR analysis and GPC analysis were performed. As a result, it was confirmed that the produced polymer changed to a high molecular weight with the passage of time and the increase in the reaction rate of the monomer, and the polymerization proceeded in a living manner (see FIG. 17).

[Example 18] (EA with MDTA via heat)
A stirrer was placed in the test tube, and 0.017 g of MDTA, 1.5 g of EA, 0.0035 g of V-601, and 3.5 g of toluene were added and dissolved. Next, freeze degassing was performed three times, and then the test tube was sealed and heated at 70° C. for 24 hours. During this time, the reaction solution was extracted after 1 hour, 2 hours, 4 hours, 10.5 hours, and 24 hours, and the extracted solution was exposed to air to terminate the polymerization, and ¹ H-NMR analysis and GPC analysis were performed. As a result, it was confirmed that the produced polymer changed to a high molecular weight with the passage of time and an increase in the reaction rate of the monomer, and the polymerization proceeded in a living manner (see FIG. 18).

The above results show that by radically polymerizing vinyl monomers in the presence of the tropolone derivative represented by formula (1) above, polymerization proceeded while precisely controlling the molecular weight and molecular weight distribution. These results confirm that the tropolone derivative represented by formula (1) above is useful as a living radical polymerization inhibitor. Furthermore, in polymerization using the tropolone derivative represented by formula (1) above as a living radical polymerization inhibitor, the polymer produced was almost free of coloration and odor, and coloration and odor could be suppressed.

The present invention is not limited to the above-described embodiment, but includes various modifications and modifications within the scope of equivalents, without departing from the spirit of the present invention. Therefore, in light of the above teachings, various combinations and forms, as well as other combinations and forms that include only one element, more than one element, or less than one element, should be understood to fall within the scope and concept of the present invention.

Claims (14)

A method for producing a vinyl polymer, comprising polymerizing a vinyl monomer in the presence of a compound represented by the following formula (1):

(In formula (1), n is an integer of 1 to 6. ^{R 0} and R ¹ are each independently a hydrogen atom, a cyano group, a monovalent hydrocarbon group which may have a substituent, a monovalent heterocyclic group which may have a substituent, an acetyl group, or -COOY ^1. Y ¹ is a hydrogen atom or a monovalent hydrocarbon group which may have a substituent. When n is 1, R ² is a monovalent hydrocarbon group which may have a substituent, a monovalent heterocyclic group which may have a substituent, an acetyl group, or -COOY ^2. When n is 2 or more, R 2 is an n-valent group which is bonded to the carbon atom to which R ⁰ and R ¹ are bonded via an ester bond and has a chain hydrocarbon structure in which the remaining portion may have an ether bond. Y ² is a hydrogen atom or a monovalent hydrocarbon group which may have a substituent. X is an alkyl group or a monovalent electron-withdrawing group. m is an integer of 0 to 5.) The method for producing a vinyl polymer according to claim 1, wherein the vinyl monomer is polymerized by irradiating it with active energy rays or applying heat. The method for producing a vinyl polymer according to claim 1 or 2, wherein the polymerization is living radical polymerization. The method for producing a vinyl polymer according to claim 1 or 2, wherein the polymerization temperature is -10°C to 120°C. 3. The method for producing a vinyl polymer according to claim 1 or 2, wherein R ¹ in the above (1) is a hydrogen atom, a cyano group, a monovalent hydrocarbon group which may have a substituent, an acetyl group, or -COOY ¹ . The method for producing a vinyl polymer according to claim 1 or 2, wherein n in the above formula (1) is 1. The method for producing a vinyl polymer according to claim 6, wherein ^R2 in the formula (1) is a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, an acetyl group, a pyridyl group, or ^-COOY2 . The method for producing a vinyl polymer according to claim 1 or 2, wherein n in formula (1) is 2 or more. the vinyl polymer is a block copolymer having a first polymer block and a second polymer block,
a step of obtaining the first polymer block by polymerizing a vinyl monomer constituting the first polymer block in the presence of a compound represented by formula (1);
polymerizing a vinyl monomer constituting the second polymer block in the presence of the first polymer block;
The method for producing the vinyl polymer according to claim 1 or 2, comprising: A living radical polymerization inhibitor represented by the following formula (1):

(In formula (1), n is an integer of 1 to 6. ^{R 0} and R ¹ are each independently a hydrogen atom, a cyano group, a monovalent hydrocarbon group which may have a substituent, a monovalent heterocyclic group which may have a substituent, an acetyl group, or -COOY ^1. Y ¹ is a hydrogen atom or a monovalent hydrocarbon group which may have a substituent. When n is 1, R ² is a monovalent hydrocarbon group which may have a substituent, a monovalent heterocyclic group which may have a substituent, an acetyl group, or -COOY ^2. When n is 2 or more, R 2 is an n-valent group which is bonded to the carbon atom to which R ⁰ and R ¹ are bonded via an ester bond and has a chain hydrocarbon structure in which the remaining portion may have an ether bond. Y ² is a hydrogen atom or a monovalent hydrocarbon group which may have a substituent. X is an alkyl group or a monovalent electron-withdrawing group. m is an integer of 0 to 5.) The living radical polymerization control agent according to claim 10, wherein R ¹ in the above (1) is a hydrogen atom, a cyano group, a monovalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, an acetyl group, or -COOY ¹ . The living radical polymerization control agent according to claim 10 or 11, wherein n in the above formula (1) is 1. The living radical polymerization control agent according to claim 12, wherein ^R2 in the above formula (1) is a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, an acetyl group, a pyridyl group, or ^-COOY2 . The living radical polymerization control agent according to claim 10 or 11, wherein n in formula (1) is 2 or more.

Images