Method for producing vinyl polymer and living radical polymerization control agent

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 polymers and living radical polymerization inhibitor

[0001] [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 inhibitor.

[0002] Radical polymerization is widely used industrially because it allows monomers to be polymerized easily and economically to obtain polymers. However, radical polymerization has the drawback that it is difficult to synthesize polymers with well-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, active development has been underway in living radical polymerization, a polymerization method that consists of an initiation reaction and a propagation reaction and is free of side reactions.

[0003] Known living radical polymerization methods include 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 technique 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). ATRP is useful as a method for producing vinyl polymers having specific functional groups at their polymer terminals because the terminals of the living polymers obtained by the polymerization reaction contain halogens or the like that are relatively advantageous for functional group conversion reactions, making it easy to introduce desired functional groups into the polymer terminals.

[0004] In the reversible addition-fragmentation chain transfer polymerization (RAFT) method, controlled polymerization proceeds via 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 allows for a wide range of monomers to be selected, and has been widely used in recent years as a method for producing a variety of well-controlled block copolymers.

[0005] The polymerization method using an organotellurium compound (TERP method) is a technique 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 is capable of living polymerization of many vinyl monomers such as styrene, various (meth)acrylates, (meth)acrylic acid, and vinylpyrrolidone.

[0006] JP-T-2000-500516A JP-T-2000-515181A WO 2004 / 014848

[0007] However, the ATRP method is prone to deep coloration due to transition metals, and there are concerns that it will lead to high costs if metals need to be removed for safety reasons. Furthermore, the RAFT method has sometimes been problematic due to coloration and a sulfur odor derived from thiocarbonylthio groups. The TERP method has sometimes been problematic due to tellurium breath having a garlic-like odor derived from organotellurium compounds, and teratogenicity. Therefore, it is desirable to develop a new method for living radical polymerization that differs from conventional methods.

[0008] The present disclosure has been made in view of the above circumstances, and one object thereof is to provide a novel production method by which vinyl polymers having precisely controlled molecular weights and molecular weight distributions can be obtained, and another object thereof is to provide a novel living radical polymerization controller for use in living radical polymerization.

[0009] The present inventors have conducted extensive research and discovered a novel living radical polymerization controller, which has 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 controller.

[0010] [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 from 1 to 6. R ０ and R １ each independently represents a hydrogen atom, a cyano group, an optionally substituted monovalent hydrocarbon group, an optionally substituted monovalent heterocyclic group, an acetyl group, or —COOY １ Y １ R is a hydrogen atom or a monovalent hydrocarbon group which may have a substituent. ２ represents, when n is 1, a monovalent hydrocarbon group which may have a substituent, a monovalent heterocyclic group which may have a substituent, an acetyl group, or —COOY ２ and when n is 2 or more, R ０ and R １ and the remaining portion is an n-valent group having a chain hydrocarbon structure which may have an ether bond. 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] A method for producing a vinyl polymer according to [1], wherein the vinyl monomer is polymerized by irradiation with active energy rays or by application of heat. [3] A method for producing a vinyl polymer according to [1] or [2], wherein the polymerization is living radical polymerization. [4] A method for producing a vinyl polymer according to any one of [1] to [3], wherein the polymerization temperature is -10°C to 120°C. [5] A method for producing a vinyl polymer according to any one of [1] to [3], wherein R in the above (1) 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 [4], wherein n in the formula (1) is 1. [7] The method for producing a vinyl polymer according to any one of [1] to [5], wherein R in the formula (1) is ２is a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, an acetyl group, a pyridyl group, or -COOY ２ [8] A method for producing a vinyl polymer according to any one of [1] to [5], wherein n in the above formula (1) is 2 or more. [9] A 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 the above formula (1); and polymerizing a vinyl monomer constituting the second polymer block in the presence of the first polymer block.

[10] A living radical polymerization controller represented by the following formula (1): (In formula (1), n ​​is an integer from 1 to 6. R ０ and R １ each independently represents a hydrogen atom, a cyano group, an optionally substituted monovalent hydrocarbon group, an optionally substituted monovalent heterocyclic group, an acetyl group, or —COOY １ Y １ R is a hydrogen atom or a monovalent hydrocarbon group which may have a substituent. ２ represents, when n is 1, a monovalent hydrocarbon group which may have a substituent, a monovalent heterocyclic group which may have a substituent, an acetyl group, or —COOY ２ and when n is 2 or more, R ０ and R １ and the remaining portion is an n-valent group having a chain hydrocarbon structure which may have an ether bond. 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] R in the above (1) 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 of

[10] or

[11] , wherein n in the above formula (1) is 1.

[13] The living radical polymerization inhibitor of

[10] or

[11] , wherein R in the above formula (1) is ２ is a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, an acetyl group, a pyridyl group, or -COOY ２

[14] The living radical polymerization controller of

[10] or

[11] , wherein n in the formula (1) is 2 or more.

[0011] According to the present disclosure, it is possible to provide a novel production method by which a vinyl polymer having a precisely controlled molecular weight and molecular weight distribution can be obtained, and also to provide a novel living radical polymerization controller for use in living radical polymerization.

[0012] FIG. 1 shows the synthesis results of Example 1 ( １ H-NMR spectrum, １３ C-NMR spectrum, FT-IR spectrum, and DART-MS. １ H-NMR spectrum, １３ C-NMR spectrum, FT-IR spectrum, and DART-MS. １ H-NMR spectrum, １３ C-NMR spectrum, FT-IR spectrum). １ H-NMR spectrum, １３ C-NMR spectrum, FT-IR spectrum, and DART-MS. １ H-NMR spectrum, １３ C-NMR spectrum, FT-IR spectrum, and DART-MS. １ H-NMR spectrum, １３FIG. 7 shows the polymerization results of Example 7 (time-conversion plot, conversion-Mn, Mw / Mn plot, GPC chart). FIG. 8 shows the polymerization results of Example 8 (time-conversion plot, conversion-Mn, Mw / Mn plot, GPC chart). FIG. 9 shows the polymerization results of Example 9 (time-conversion plot, conversion-Mn, Mw / Mn plot, GPC chart). FIG. 10 shows the polymerization results of Example 10 (time-conversion plot, conversion-Mn, Mw / Mn plot, GPC chart). FIG. 11 shows the polymerization results of Example 11 (GPC chart). FIG. 12 shows the polymerization results of Example 12 (GPC chart). FIG. 13 shows the polymerization results of Example 13 (time-conversion plot, conversion-Mn, Mw / Mn plot, and GPC chart). FIG. 14 shows the polymerization results of Example 14 (time-conversion plot, conversion-Mn, Mw / Mn plot, and GPC chart). FIG. 15 shows the polymerization results of Example 15 (time-conversion plot, conversion-Mn, Mw / Mn plot, and GPC chart). FIG. 16 shows the polymerization results of Example 16 (time-conversion plot, conversion-Mn, Mw / Mn plot, and GPC chart). FIG. 17 shows the polymerization results of Example 17 (time-conversion plot, conversion-Mn, Mw / Mn plot, and GPC chart). FIG. 18 shows the polymerization results of Example 18 (Time-Conv. plot, Conv.-Mn, Mw / Mn plot, GPC chart).

[0013] 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.

[0014] <<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 from 1 to 6. R ０ and R １ each independently represents a hydrogen atom, a cyano group, an optionally substituted monovalent hydrocarbon group, an optionally substituted monovalent heterocyclic group, an acetyl group, or —COOY １ Y １ R is a hydrogen atom or a monovalent hydrocarbon group which may have a substituent. ２ represents, when n is 1, a monovalent hydrocarbon group which may have a substituent, a monovalent heterocyclic group which may have a substituent, an acetyl group, or —COOY ２ and when n is 2 or more, R ０ and R １ and the remaining portion is an n-valent group having a chain hydrocarbon structure which may have an ether bond. ２ represents a hydrogen atom or a monovalent hydrocarbon group which may have a substituent; X represents an alkyl group or a monovalent electron-withdrawing group; and m represents an integer of 0 to 5.

[0015] 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, living radical polymers can be obtained by polymerizing vinyl monomers in the presence of tropolone derivatives. In particular, the production method of the present disclosure is advantageous in that it can produce vinyl polymers with precisely controlled molecular weight and molecular weight distribution while suppressing the generation of coloration and odor. Matters related to the production method of the present disclosure will be described in detail below.

[0016] <Tropolone Derivative> A tropolone derivative has a structure in which the hydrogen atom of the hydroxyl group of tropolone is replaced with a monovalent organic group. ０ , R １ , R ２ , Y １ , Y ２Examples of the monovalent hydrocarbon group represented by the formula (I) include alkyl groups having 1 to 20 carbon atoms, cycloalkyl groups having 3 to 20 carbon atoms, and aromatic hydrocarbon groups having 6 to 20 carbon atoms (aryl groups, aralkyl groups). Specific examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl, n-heptyl, and n-octyl groups. Of these, linear or branched alkyl groups having 1 to 6 carbon atoms are preferred, and linear or branched alkyl groups having 1 to 4 carbon atoms are more preferred.

[0017] Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Of these, a cyclohexyl group is preferred.

[0018] Examples of the aromatic hydrocarbon group include aryl groups such as phenyl, methylphenyl, and naphthyl; and aralkyl groups such as benzyl and phenethyl. Of these, the phenyl group is preferred.

[0019] R ０ , R １ , R ２ Examples of the monovalent heterocyclic group represented by the formula (I) include a pyridyl group, an imidazolyl group, a benzimidazolyl group, a furyl group, a thienyl group, etc. Among these, a pyridyl group is preferred.

[0020] R ０ , R １ , R ２ , Y １ , Y ２ When the heterocyclic group 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.

[0021] R in (1) above ０ , R １ is, from the viewpoint of ease of synthesis, 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 -COOY１ is 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 (However, Y ３ is more preferably an alkyl group having 1 to 6 carbon atoms, a cyclohexyl group, or a phenyl group. ０ , R １ and R ２ From the viewpoint of increasing the detachability of the carbon to which R is bonded, ０ and R １ At least one of these is preferably a methyl group.

[0022] R ２ represents, when n is 1, a monovalent hydrocarbon group which may have a substituent, a monovalent heterocyclic group which may have a substituent, an acetyl group, or —COOY ２ It is. ２ is, among these, 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 -COOY ２ is preferably an alkyl group having 1 to 6 carbon atoms, a phenyl group, an acetyl group, a pyridyl group, or —COOY ４ (However, Y ４ is an alkyl group having 1 to 6 carbon atoms, a cyclohexyl group, or a phenyl group).

[0023] When n is 2 or more, R ２ is R ０ and R １ and n-valent group having a chain hydrocarbon structure of 1 to 20 carbon atoms, which is bonded via an ester bond to the carbon atom to which n is bonded, and the remaining portion 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, R ３ are each independently a linear or branched alkylene group having 2 to 6 carbon atoms, and each r is independently an integer of 0 to 3.

[0024] 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 R １ , R ２ , Y １ , Y ２ Examples of the alkyl group represented by the formula (1) include the same groups as those exemplified above. 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. ０ , R １ and R ２ Of the above, X is preferably an isopropyl group or a nitro group, from the viewpoint of increasing the elimination property of the carbon to which is bonded, ease of availability of raw materials, and ease of synthesis. m is preferably 0 to 2, and more preferably 0 or 1. n is preferably 1 to 4, and preferably 1 or 2, from the viewpoint of ease of availability of raw materials and ease of synthesis.

[0025] Specific examples of the compound represented by the above formula (1) (tropolone derivative) include compounds represented by the following formula:

[0026] <Method for Producing Tropolone Derivatives> The method for producing tropolone derivatives is not particularly limited, and tropolone derivatives can be produced appropriately based on the structure of each tropolone derivative. As a method for producing the compound represented by the above formula (1), for example, a method for producing a compound represented by the above formula (1) can be carried out by combining a compound having a tropolone skeleton with a compound represented by the formula (1) "-C(CH ３ ) (R １ ) (R ２ )) (hereinafter, also referred to as "halide (X)")) having a structure corresponding to the above-mentioned formula (specifically, a nucleophilic reaction).

[0027] Examples of compounds having a tropolone skeleton that can be used in the above reaction include tropolone and hinokitiol.

[0028] As the halide (X), a compound corresponding to the number 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) where Z is a halogen atom and R １ and R ２ are R in the above formula (1), １ , R ２ Z is preferably a chlorine atom, a bromine atom or an iodine atom, and more preferably a chlorine atom or a bromine atom, in view of high reactivity.

[0029] In the above reaction, the ratio of the compound having a tropolone skeleton to the halide (X) can be appropriately set depending on the number n in the above formula (1). For example, when obtaining a compound in the above formula (1) where n is 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.

[0030] 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 thereof include acetonitrile, acetone, ethyl acetate, tert-butyl methyl ether, diethyl ether, tetrahydrofuran, 1,4-dioxane, etc. One solvent may be used alone, or two or more solvents may be used in combination. The amount of solvent used may be appropriately determined, but from the viewpoint of carrying out the reaction efficiently, it can be, for example, 5 to 60 mass %.

[0031] The reaction of the compound having a tropolone skeleton with 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.

[0032] Specific examples of the base include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, and cesium hydroxide; alkaline earth metal hydroxides such as magnesium hydroxide and calcium hydroxide; alkali metal chlorides such as lithium chloride, sodium chloride, and potassium chloride; alkaline earth metal chlorides such as magnesium chloride and calcium chloride; alkali metal alkoxides such as lithium methoxide, lithium ethoxide, lithium isopropoxide, sodium methoxide, sodium ethoxide, sodium isopropoxide, potassium methoxide, and potassium tert-butoxide; alkaline earth metal alkoxides such as magnesium ethoxide; alkali metal carbonates such as lithium carbonate, sodium carbonate, and potassium carbonate; alkaline earth metal carbonates such as magnesium carbonate and calcium carbonate; alkali metal bicarbonates such as sodium bicarbonate and potassium bicarbonate; alkaline earth metal bicarbonates such as calcium bicarbonate and barium bicarbonate; alkali metal oxides such as lithium oxide, sodium oxide, and potassium oxide; alkaline earth metal oxides 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.

[0033] When a base is used in the above reaction, the amount of the base used is, for example, 0.1 to 10 mol, preferably 0.2 to 5 mol, per 1 mol of the halide (X).

[0034] The reaction temperature and reaction time in the reaction between the compound having a tropolone skeleton and the halide (X) can be adjusted appropriately 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 efficiently proceed with the reaction. The reaction is usually carried out under normal pressure, but may also be carried out under increased or reduced pressure.

[0035] The above reaction can produce the desired tropolone derivative. When the tropolone derivative obtained by the reaction is isolated and / or purified, known methods can be used for the isolation and / or purification treatment.

[0036] <Vinyl Monomer> In the living radical polymerization using a tropolone derivative, the vinyl monomer used is not particularly limited as long as it is a radically polymerizable monomer. Examples of the vinyl monomer used in the production 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 acid 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.

[0037] Further specific examples of vinyl-based 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.

[0038] Specific examples of the aliphatic cyclic ester compound 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.

[0039] 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.

[0040] Specific examples of the (meth)acrylic acid alkoxyalkyl ester compound 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.

[0041] Specific examples of the (meth)acrylic acid hydroxyalkyl ester compound 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.

[0042] Specific examples of the (meth)acrylic compound 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.

[0043] Examples of vinyl compounds having a heterocyclic structure include glycidyl (meth)acrylate, (3,4-epoxycyclohexyl)methyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate.

[0044] Examples of the amino group-containing vinyl compound 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, and 3-(di-n-propylamino)propyl (meth)acrylate.

[0045] Examples of the amide group-containing vinyl compound include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, and N-methylol(meth)acrylamide.

[0046] Examples of the cyano group-containing vinyl compound 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.

[0047] Examples of the nitrile group-containing vinyl compound include (meth)acrylonitrile, ethacrylonitrile, α-ethylacrylonitrile, α-isopropylacrylonitrile, α-chloroacrylonitrile, and α-fluoroacrylonitrile.

[0048] Examples of 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.

[0049] Examples of the maleimide compound include maleimide and N-substituted maleimide compounds. Examples of the N-substituted maleimide compound 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.

[0050] 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, etc. Specific examples of unsaturated acid anhydrides include maleic anhydride, itaconic anhydride, and citraconic anhydride, etc.

[0051] Among these, the vinyl-based 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.

[0052] In the polymerization, the amount of the tropolone derivative used may be adjusted appropriately 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 mol of the tropolone derivative. The tropolone derivative may be used alone or in combination of two or more.

[0053] Living radical polymerization using a tropolone derivative may be carried out in the absence of a solvent or in a solvent. Solvents commonly used in radical polymerization can 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. Alternatively, an aqueous solvent may be used as the solvent. Examples of the aqueous solvent include water and a mixed solvent of water and an alcohol.

[0054] When a solvent is used in the polymerization, the amount of the solvent may be adjusted as appropriate, for example, 1 to 1,000 parts by mass, or 5 to 200 parts by mass, relative to 100 parts by mass of the total amount of vinyl-based 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.

[0055] The polymerization is initiated and progresses by irradiating a reaction system containing a vinyl monomer and a tropolone derivative with active energy rays or by applying heat.

[0056] Examples of active energy rays include ultraviolet rays, visible light, and electron beams. Of these, ultraviolet rays are preferred. The irradiation energy can be appropriately set depending on the type of active energy rays, the type and concentration of the monomer, the type and concentration of the tropolone derivative, etc.

[0057] For example, when ultraviolet rays are used as the active energy rays, the wavelength is, for example, 250 to 420 nm. Examples of ultraviolet irradiation devices include high-pressure mercury lamps, metal halide lamps, ultraviolet electrodeless lamps, and ultraviolet light-emitting diodes (UV-LEDs). The cumulative light amount is 0.5 J / cm. ２ More than 1.0 J / cm is preferable. ２ More preferably, 1.5 J / cm or more ２ The upper limit of the cumulative light amount is more preferably 250 J / cm in order to minimize the influence on each component in the reaction system and to reduce energy. ２ Preferably, 200 J / cm or less ２ The following is more preferred:

[0058] The illuminance and irradiation time of the ultraviolet light can be appropriately set so that the integrated light amount is a desired amount. For example, the illuminance is 1 mW / cm ２ More than 2 mW / cm is preferable. ２ More preferably, the upper limit of the illuminance is 100 mW / cm. ２ Preferably, 80 mW / cm or less ２ The following is more preferred: The irradiation time is, for example, 10 minutes to 12 hours.

[0059] When polymerization is initiated by applying heat, the heating temperature is, for example, 30 to 150°C, 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 easy to handle from a safety standpoint and are less likely to cause side reactions during radical polymerization.

[0060] Specific examples of the polymerization initiator 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), 1,1-azobis(1 ... Examples of the polymerization initiator include 2,2-azobis(4-methyl-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), and 2,2-azobis(N-cyclohexyl-2-methylpropionamide). As the polymerization initiator, one of these may be used alone, or two or more may be used in combination.

[0061] When a polymerization initiator is used in the polymerization, the amount of the polymerization initiator used may be adjusted appropriately depending on the molecular weight and molecular weight distribution of the desired living radical polymer. From the viewpoint of stably carrying out the polymerization reaction and obtaining a living radical polymer with a narrower molecular weight distribution, the amount of the polymerization initiator used is preferably 0.01 to 0.6 mol, more preferably 0.05 to 0.2 mol, per mol of the living radical polymerization control agent used in the reaction.

[0062] In the method of polymerizing a vinyl monomer using a tropolone derivative as a radical polymerization inhibitor, the method of initiating / progressing polymerization by irradiation with active energy rays allows a living radical polymerization reaction to be carried out without using a polymerization initiator, and is useful in that the inclusion of impurities in the living radical polymer after recovery can be minimized.

[0063] The process for producing living radical polymers may be batch or continuous. In the batch process, when the reaction rate is high, a semi-batch process in which monomers are fed is preferred to facilitate temperature control. In the continuous process, a tubular process, a tower process, a continuous stirred tank process (CSTR), or a combination thereof may be used. Of these, the tubular and tower processes are preferred because they can narrow the molecular weight distribution of the resulting polymer.

[0064] In 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.

[0065] For example, when a block copolymer having a first polymer block and a second polymer block is obtained using a tropolone derivative, the copolymer can be obtained by a method comprising the following first and second steps: First step: obtaining the first polymer block by polymerizing the monomers constituting the first polymer block in the presence of the tropolone derivative represented by the above formula (1); Second step: polymerizing the monomers constituting the second polymer block in the presence of the first polymer block.

[0066] As an example, when a linear triblock copolymer consisting of polymer block M / polymer block N / polymer block M is obtained by living radical polymerization, the desired block copolymer can be obtained by using a tropolone derivative in which n in the above formula (1) is 1 as a living polymerization inhibitor and sequentially carrying out polymerizations to obtain each block. In this case, first, in the first step, a monomer constituting polymer block M is polymerized to obtain polymer block M, and then, in the second step, a monomer constituting polymer block N is polymerized to obtain polymer block N. Furthermore, in the third step, a monomer constituting polymer block M is polymerized. This allows for the production of a linear triblock copolymer consisting of polymer block M / polymer block N / polymer block M. Furthermore, by sequentially carrying out steps 4 and 5, etc., a multiblock copolymer having four or more blocks can also be obtained.

[0067] Furthermore, when a linear triblock copolymer consisting of polymer block M / polymer block N / polymer block M is obtained by living radical polymerization, the desired block copolymer can be obtained more efficiently by using a tropolone derivative in which n is 2 in the above formula (1) as a living polymerization inhibitor and performing polymerization to obtain each block. In this case, in the first step, the monomer constituting polymer block N, which is located in the center of the desired block copolymer, is polymerized to obtain polymer block N. Subsequently, in the second step, the monomer constituting polymer block M is polymerized to obtain polymer block M. This allows for the production of a triblock copolymer consisting of polymer block M / polymer block N / polymer block M. Furthermore, by successively performing steps 3, 4, etc., a multiblock copolymer having five or more blocks can also be obtained. This method simplifies the polymer production process compared to when each block is produced by sequentially polymerizing it. Furthermore, polymerization using a tropolone derivative in which n is 2 in the above formula (1) as a living polymerization inhibitor can also produce a telechelic polymer having X in the above formula (1) or a reactive group derived from X (for example, a hydroxyl group, an epoxy group, a carboxyl group, a (meth)acryloyl group, a sulfonic acid group, etc.) at both ends.

[0068] Furthermore, 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 the number of branched chains corresponding to n can be obtained.

[0069] The reaction temperature and reaction time of the living radical polymerization reaction can be adjusted appropriately depending on the molecular weight and molecular weight distribution of the desired living radical polymer. The reaction temperature is, for example, -10°C to 120°C, preferably 0 to 100°C. If the reaction temperature is too low, the time required for polymerization tends to be too long, resulting in poor productivity, and the initiation reaction tends to be slow, resulting in a broad molecular weight distribution. On the other hand, if the reaction temperature is too high, polymerization controllability tends to decrease, resulting in a broad molecular weight distribution, and side reactions tend to occur more easily. The reaction time is, for example, 10 minutes to 100 hours, preferably 30 minutes to 50 hours. From the perspective of efficiently progressing the reaction, polymerization may be carried out while stirring the reaction system. Polymerization is usually carried out under normal pressure, but may also be carried out under increased or reduced pressure.

[0070] By such a polymerization reaction, the target living radical polymer can be obtained. When the living radical polymer obtained by the polymerization reaction is subjected to isolation and / or purification treatment, known methods can be used for these treatments.

[0071] The molecular weight of the living radical polymer obtained by the above polymerization can be appropriately adjusted by adjusting the reaction temperature, reaction time, the amount of tropolone derivative used, the amount of monomer used, etc. According to a 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. This method can produce a living radical polymer having an Mn in the range of 1,000 to 1,000,000, and is particularly suitable as a method for producing a living radical polymer having an Mn in the range of 2,000 to 100,000.

[0072] Furthermore, according to the production 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), expressed as the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn), of 1.0 to 2.5. The molecular weight distribution of the living radical polymer obtained by the above polymerization is preferably 2.2 or less, more preferably 2.0 or less. Note that, in this specification, the Mw and Mn of the polymer are values ​​calculated in terms of standard polystyrene obtained using gel permeation chromatography (GPC).

[0073] Although this disclosure is not limited to this, 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 R in the above formula (1). １ , R ２ , n and m. I represents a polymerization initiator, M represents a monomer, and Pn represents a polymer chain.

[0074]

[0075]

[0076] According to the production 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 inhibitor.

[0077] The present disclosure will be specifically described below based on examples. However, 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.

[0078] The molecular weight measurement of the vinyl polymer obtained by living radical polymerization using the tropolone derivative obtained in each example is described below.

[0079] <Molecular Weight Measurement> The obtained vinyl polymer was subjected to gel permeation chromatography (GPC) measurement 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: TSKgel GMH manufactured by Tosoh Corporation ＨＲ -M x 3 Solvent: tetrahydrofuran Temperature: 40°C Detector: RI, UV (322 nm) Flow rate: 1.0 mL / min

[0080] <Synthesis of Tropolone Derivatives> [Example 1] (Synthesis of MDTA) A compound represented by the following formula (referred to as "MDTA") was synthesized by the following procedure.

[0081] A 300 mL two-necked recovery flask was equipped with a stirrer, 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. Next, 17 mL (131 mmol) of methyl α-bromoisobutyrate was slowly added dropwise from the dropping funnel. After the addition, the mixture was allowed to react 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 aqueous sodium hydroxide to remove potassium carbonate, tetraethylammonium bromide, and unreacted tropolone. After pre-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 Ltd.)] 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%. １ H-NMR, １３ The results were confirmed by C-NMR, FT-IR, and DART-MS, and are shown in Figure 1.

[0082] In addition, in FIG. １ H-NMR spectrum, (b) １３ (c) shows the C-NMR spectrum, (c) shows the DART-MS spectrum, and (d) shows the FT-IR spectrum (the same applies to Figures 2, 4, and 5).

[0083] Example 2 Synthesis of MDITA A compound represented by the following formula (referred to as "MDITA") was synthesized by the following procedure.

[0084] 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 allowed to react 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 aqueous sodium hydroxide to remove potassium carbonate, tetraethylammonium bromide, and unreacted hinokitiol. After pre-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 Ltd.)] 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%. １ H-NMR, １３ The results were confirmed by C-NMR, FT-IR, and DART-MS, and are shown in Figure 2.

[0085] [Example 3] (NO ２ Synthesis of -MDTA) A compound represented by the following formula (referred to as "NO ２ -MDTA") was synthesized by the following procedure.

[0086] A stirrer was placed in a 50 mL two-necked recovery flask, and 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 (HNO３ The resulting mixture was stirred at room temperature for 24 hours to react. After the reaction, the mixture was dissolved in dichloromethane and thoroughly washed with sodium bicarbonate water and ion-exchanged water to remove tetraethylammonium bromide and other compounds. The organic phase was removed by evaporation to obtain the target compound (NO) in a 51% yield. ２ -MDTA) was obtained. １ H-NMR, １３ The results were confirmed by C-NMR and FT-IR, and are shown in Figure 3.

[0087] In addition, in FIG. １ H-NMR spectrum, (b) １３ (a) shows the C-NMR spectrum, and (b) shows the FT-IR spectrum.

[0088] Example 4 Synthesis of MMTA A compound represented by the following formula (referred to as "MMTA") was synthesized by the following procedure.

[0089] A stirrer was placed in a 300 mL two-necked recovery flask. 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 addition, the reaction was allowed to proceed at 90°C for 24 hours. After the reaction, the acetonitrile was removed by evaporation, the mixture was dissolved in ethyl acetate, and then washed with aqueous sodium hydroxide to remove potassium carbonate and unreacted tropolone. After pre-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 Ltd.)] using a 1:2 (volume ratio) mixed solvent of n-hexane and ethyl acetate (Rf = 0.47). The target compound (MMTA) was obtained in 37% yield. The synthesis results are shown below. １ H-NMR, １３ The results were confirmed by C-NMR, FT-IR, and DART-MS, and are shown in Figure 4.

[0090] Example 5 Synthesis of MBZTA A compound represented by the following formula (referred to as "MBZTA") was synthesized by the following procedure.

[0091] A 300 mL two-necked eggplant flask was equipped with a stirrer, 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 slowly added dropwise via the dropping funnel. After the addition, the mixture was allowed to react at 90°C for 24 hours. After the reaction, the acetonitrile was removed by evaporation, the mixture was dissolved in ethyl acetate, and then washed with aqueous sodium hydroxide to remove potassium carbonate, tetraethylammonium bromide, and unreacted tropolone. After pre-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 Ltd.)] 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%. １ H-NMR, １３ The results were confirmed by C-NMR, FT-IR, and DART-MS, and are shown in Figure 5.

[0092] Example 6 Synthesis of bis-MDTA A compound represented by the following formula (hereinafter referred to as "bis-MDTA") was synthesized by the following procedure.

[0093] A stirrer was placed in a 300 mL two-necked recovery 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 prepared by dissolving 5.0 g (13.9 mmol) of ethylene bis(2-bromoisobutyrate) in 16 mL of acetonitrile was added to the dropping funnel, and this solution was slowly added dropwise to the recovery flask. After the dropwise addition, 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 aqueous sodium hydroxide to remove potassium carbonate, tetraethylammonium bromide, and unreacted tropolone. After pre-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 Ltd.)] 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. １ H-NMR, １３ The results were confirmed by C-NMR and DART-MS. The results are shown in Figure 6. In Figure 6, (a) １ H-NMR spectrum, (b) １３ (c) shows the C-NMR spectrum, and (d) shows the DART-MS spectrum.

[0094] <Production of vinyl polymer> [Example 7] (EA with MDTA via MFlamp) A stirrer was placed in a 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 heated at room temperature using a metal halide lamp (LS-140UV, manufactured by Sumita Optical Glass Co., Ltd., wavelength 290 to 420 nm, illuminance 21 mW / cm). ２ The reaction solution was irradiated with light (365 nm) for 4 hours. During this time, the reaction solution was withdrawn after 15 minutes, 30 minutes, 1 hour, 2 hours, and 4 hours, and the withdrawn solution was exposed to air to terminate the polymerization. １H-NMR analysis and GPC analysis were performed, and it was confirmed that the produced polymer increased in molecular weight with the passage of time and with an increase in the reaction rate of the monomer, and that the polymerization proceeded in a living manner (see Figure 7).

[0095] In FIG. 7, (a) shows the relationship between time (horizontal axis, Time (h)) and the monomer reaction rate (vertical axis, Conv. (%)), (b) shows the relationship between the monomer conversion rate (horizontal axis) and the polymer number-average molecular weight (vertical axis), and (c) shows the changes in the number-average molecular weight and molecular weight distribution with time and the monomer reaction rate (the same applies to FIGS. 8 to 10 and 13 to 18).

[0096] [Example 8] (St with MDTA via MFlamp) A stirrer was placed in a 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. After three cycles of freeze-degassing, 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 withdrawn after 1, 2, 4, 8, and 24 hours, and the withdrawn solution was exposed to air to terminate the polymerization. １ H-NMR analysis and GPC analysis were performed, and it was confirmed that the produced polymer increased in molecular weight with the passage of time and with an increase in the reaction rate of the monomer, and that the polymerization proceeded in a living manner (see Figure 8).

[0097] [Example 9] (VAc with MDTA via MFlamp) A stirrer was placed in a 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 withdrawn after 2 hours, 5 hours, 8 hours, 13 hours, and 24 hours, and the withdrawn solution was exposed to air to terminate the polymerization. １ H-NMR analysis and GPC analysis were performed, and it was confirmed that the produced polymer increased in molecular weight with the passage of time and with an increase in the reaction rate of the monomer, and that the polymerization proceeded in a living manner (see Figure 9).

[0098] Example 10 (EA with MDTA via UV-LED (365 nm)) A stirrer was placed in a test tube, and 0.017 g of MDTA, 1.5 g of EA, and 3.5 g of toluene were added and dissolved. The test tube was then subjected to three cycles of freeze-degassing and then sealed. The solution was then exposed to UV-LED (PER-365, manufactured by TechnoSigma, peak wavelength 365 nm, illuminance 7.5 mW / cm) at room temperature. ２ The light from a UV-LED (hereinafter simply referred to as "UV-LED") was irradiated for 4 hours by inserting the light-emitting part directly 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 stop the polymerization. １ H-NMR analysis and GPC analysis were performed, and it was confirmed that the produced polymer increased in molecular weight with the passage of time and with an increase in the reaction rate of the monomer, and that the polymerization proceeded in a living manner (see Figure 10).

[0099] [Example 11] (PVAc Macro to St block via MFlamp) A stirrer was placed in a test tube, and 0.064 g of MDTA and 5.0 g of VAc were added and dissolved. After three cycles of freeze-degassing, the test tube was sealed and irradiated with light from a metal halide lamp at room temperature. 49 hours after the start of the reaction, the polymerization was terminated by exposure to air. １ H-NMR analysis and GPC analysis were carried out. 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 the 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 carried out three times, after which 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, １ H-NMR analysis and GPC analysis were performed. The conversion rate of St was 27%, and the resulting polymer changed to a polymer with a higher molecular weight than the PVAc used with the passage of time and an increase in the reaction rate of the monomer, confirming that block copolymerization had progressed (see FIG. 11 ).

[0100] [Example 12] (PVAc Macro to EA block via MFlamp) Polymerization of VAc was carried out in the same manner as in Example 11 to obtain PVAc having the same Mn and Mw / Mn as in Example 11. 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, after which 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. １ H-NMR analysis and GPC analysis were performed. The conversion rate of EA was 67%, and the resulting polymer changed to a polymer with a higher molecular weight than the PVAc used with the passage of time and an increase in the reaction rate of the monomer, confirming that block copolymerization had progressed (see FIG. 12 ).

[0101] Example 13 (EA with MDITA via UV-LED (365 nm)) A stirrer was placed in a 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 irradiated with UV-LED light at room temperature for 4 hours by inserting the light-emitting part directly into the test tube. During this time, the reaction solution was withdrawn after 15 minutes, 30 minutes, 1 hour, 2 hours, and 4 hours, and the withdrawn solution was exposed to air to terminate the polymerization. １ H-NMR analysis and GPC analysis were performed, and it was confirmed that the produced polymer increased in molecular weight with the passage of time and with an increase in the reaction rate of the monomer, and that the polymerization proceeded in a living manner (see Figure 13).

[0102] [Example 14] (EA with NO ２ -MDTA via UV-LED (365 nm)) Place a stir bar in the test tube and then NO ２ 0.015 g of MDTA, 1.5 g of EA, and 3.5 g of toluene were added and dissolved. Next, after three cycles of freeze-degassing, the test tube was sealed and irradiated with UV-LED light at room temperature for 4 hours by inserting the light-emitting part directly into the test tube. During this time, the reaction solution was withdrawn after 15 minutes, 30 minutes, 1 hour, 2 hours, and 4 hours, and the withdrawn solution was exposed to air to terminate the polymerization. １H-NMR analysis and GPC analysis were performed, and it was confirmed that the produced polymer increased in molecular weight with the passage of time and with an increase in the reaction rate of the monomer, and that the polymerization proceeded in a living manner (see Figure 14).

[0103] Example 15 (EA with MMTA via UV-LED (365 nm)) A stirrer was placed in a 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. UV-LED light was irradiated at room temperature for 24 hours by inserting the light-emitting part directly into the test tube. During this time, the reaction solution was withdrawn after 15 minutes, 30 minutes, 1 hour, 2.5 hours, 4 hours, and 6 hours, and the withdrawn solution was exposed to air to terminate the polymerization. １ H-NMR analysis and GPC analysis were performed, and it was confirmed that the produced polymer increased in molecular weight with the passage of time and with an increase in the reaction rate of the monomer, and that the polymerization proceeded in a living manner (see Figure 15).

[0104] Example 16 (EA with MBZTP via UV-LED (365 nm)) A stirrer was placed in a 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. UV-LED light was irradiated at room temperature for 24 hours by inserting the light-emitting part directly into the test tube. During this time, the reaction solution was withdrawn after 30 minutes, 1 hour, 2 hours, 4 hours, and 6 hours, and the withdrawn solution was exposed to air to terminate the polymerization. １ H-NMR analysis and GPC analysis were performed, and it was confirmed that the produced polymer increased in molecular weight with the passage of time and with an increase in the reaction rate of the monomer, and that the polymerization proceeded in a living manner (see Figure 16).

[0105] Example 17 (EA with bis-MDTA via UV-LED (365 nm)) A stirrer was placed in a 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 irradiated with UV-LED light at room temperature by inserting the light-emitting part directly into the test tube for 24 hours. During this time, the reaction solution was withdrawn after 15 minutes, 30 minutes, 1 hour, 2 hours, and 4 hours, and the withdrawn solution was exposed to air to terminate the polymerization. １ H-NMR analysis and GPC analysis were performed, and it was confirmed that the produced polymer increased in molecular weight with the passage of time and with an increase in the reaction rate of the monomer, and that the polymerization proceeded in a living manner (see Figure 17).

[0106] Example 18 (EA with MDTA via heat) A stirrer was placed in a 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. The test tube was then subjected to three cycles of freeze-degassing, after which it was sealed and heated at 70°C for 24 hours. During this time, the reaction solution was withdrawn after 1 hour, 2 hours, 4 hours, 10.5 hours, and 24 hours, and the withdrawn solution was exposed to air to terminate the polymerization. １ H-NMR analysis and GPC analysis were performed, and it was confirmed that the produced polymer increased in molecular weight with the passage of time and with an increase in the monomer reaction rate, and that the polymerization proceeded in a living manner (see Figure 18).

[0107] These results demonstrate that radical polymerization of vinyl monomers in the presence of the tropolone derivative of formula (1) allows for precise control of molecular weight and molecular weight distribution. These results confirm that the tropolone derivative of formula (1) is useful as a living radical polymerization inhibitor. Furthermore, in polymerizations using the tropolone derivative of formula (1) as a living radical polymerization inhibitor, the resulting polymer was substantially free of coloration and odor, and coloration and odor were effectively suppressed.

[0108] The present invention is not limited to the above-described embodiments, and encompasses various modifications and equivalent modifications within the scope of the spirit of the present invention. Therefore, in light of the above teachings, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are to be understood as falling within the scope and spirit of the present invention.

Claims

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 from 1 to 6. R ０ and R １ each independently represents 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 It is. １ R is a hydrogen atom or a monovalent hydrocarbon group which may have a substituent. ２ represents, when n is 1, 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 ０ and R １ and the remaining portion is an n-valent group having a chain hydrocarbon structure which may have an ether bond. 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 claim 1, wherein the vinyl monomer is polymerized by irradiating with active energy rays or applying heat.

3. The method for producing a vinyl polymer according to claim 1 or 2, wherein the polymerization is a living radical polymerization.

4. The method for producing a vinyl polymer according to claim 1 or 2, wherein the polymerization temperature is from -10°C to 120°C.

5. R in (1) 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, 6. The method for producing a vinyl polymer according to claim 1 or 2, wherein n in the above formula (1) is 1.

7. R in the above formula (1) ２ is a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, an acetyl group, a pyridyl group, or -COOY ２ The method for producing a vinyl polymer according to claim 6, 8. The method for producing a vinyl polymer according to claim 1 or 2, wherein n in the above formula (1) is 2 or more.

9. The method for producing a vinyl polymer according to claim 1 or 2, wherein the vinyl polymer is a block copolymer having a first polymer block and a second polymer block, the method comprising: 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 from 1 to 6. R ０ and R １ each independently represents 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 It is. １ R is a hydrogen atom or a monovalent hydrocarbon group which may have a substituent. ２ represents, when n is 1, 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 ０ and R １ and the remaining portion is an n-valent group having a chain hydrocarbon structure which may have an ether bond. 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. R in (1) 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 controller according to claim 10, 12. The living radical polymerization inhibitor according to claim 10 or 11, wherein n in the above formula (1) is 1.

13. R in the above formula (1) ２ is a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, an acetyl group, a pyridyl group, or -COOY ２ The living radical polymerization controller according to claim 12, 14. The living radical polymerization inhibitor according to claim 10 or 11, wherein n in the above formula (1) is 2 or more.

Images