Method for producing polymer using disulfide compound

Abstract

To provide a polymerization method using a disulfide compound as a RAFT agent, which is a production method for obtaining a polymer having a designed molecular weight determined by a feed molar ratio between a monomer and the RAFT gent, namely a desired molecular weight.SOLUTION: A production method comprises treating a disulfide compound represented by general formula (1) in the figure [where R1 and R2 each independently represent a substituted or unsubstituted aromatic hydrocarbon group or the like] in advance with a radical initiator in the presence or absence of a solvent, and then adding at least one radical-polymerizable monomer to the treated product and subjecting it to radical polymerization to obtain a polymer.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing a polymer using a disulfide compound, more specifically, to a method for producing a polymer having a desired molecular weight by using a sequential charging method in which a specific disulfide compound is preliminarily treated with a radical initiator, and then a monomer is added and polymerized. [Background technology]

[0002] It is known that disulfide compounds can be used as reversible addition-fragmentation chain transfer (RAFT) agents (Patent Documents 1 and 2). The polymerization method using a RAFT agent is a living radical polymerization, and is characterized by easy control of the number-average molecular weight and weight-average molecular weight, and by the fact that a polymer with a narrow molecular weight distribution can be obtained. However, in the polymerization method using a disulfide compound as a RAFT agent described in the prior art (herein referred to as a lump-sum charge method), a polymer with a designed molecular weight determined by the charge molar ratio of the monomer and the RAFT agent, that is, a molecular weight about twice the desired molecular weight, is obtained, and there is a problem that the disulfide compound does not function sufficiently as a polymerization control agent (Non-Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. WO1999 / 05099 [Patent Document 2] Patent Application No. 2007-235324 [Non-patent literature]

[0004] [Non-Patent Document 1] Polymer Preprints, Japan Vol.64,No.2 (2015) Summary of the Invention [Problem to be solved by the invention]

[0005] An objective of the present invention is to provide a production method for obtaining a polymer having a designed molecular weight, i.e., a desired molecular weight, determined by the charged molar ratio of monomer and RAFT agent, in a polymerization method using a disulfide compound as a RAFT agent. [Means for solving the problem]

[0006] As a result of intensive investigations, the present inventors have found that a polymer having a designed molecular weight determined by the charged molar ratio of monomer and RAFT agent, i.e., a desired molecular weight, can be obtained by a polymer production method using a disulfide compound that has been pre-treated with a radical initiator as a polymerization control agent, and have thus completed the present invention.

[0007] Thus, according to the present invention, a compound represented by the general formula (1): [ka] [wherein R1 and R2 each independently represent a substituted or unsubstituted aromatic hydrocarbon group, or a group represented by the formula: -SXA (wherein X represents a substituted or unsubstituted linear or branched alkylene group having 1 to 20 carbon atoms in which an oxygen atom may be present between the carbon bonds of the alkylene group, if possible, or a substituted or unsubstituted cyclic alkylene group having 3 to 12 carbon atoms, and A represents a hydrogen atom, an alkylamino group, an ester group, a vinyl group, or a substituted or unsubstituted aromatic hydrocarbon group)] The present invention provides a method for producing a polymer, comprising treating a disulfide compound represented by the following formula (I) with a radical initiator in a solvent or without a solvent, and then adding at least one radically polymerizable monomer to the treated product to carry out radical polymerization.

[0008] Further, according to the present invention, there is provided a method for producing the polymer, comprising the steps of: pretreating 0.1 to 50 parts by mass of a disulfide compound with respect to 100 parts by mass of a radical polymerizable monomer with 0.1 to 50 parts by mass of a radical initiator under conditions of 1 to 200 parts by mass of a solvent, a temperature of -20 to 200°C, and a treatment time of 0.1 to 100 hours; adding at least one radical polymerizable monomer to the treated product; and radically polymerizing the resultant product under conditions of a polymerization temperature of 5 to 200°C and a polymerization time of 0.1 to 100 hours, thereby obtaining a polymer having a number average molecular weight Mn of 5 million to 1 million, a ratio of weight average molecular weight Mw to number average molecular weight Mn (Mw / Mn) of 1.0 to 5.0, and a ratio of number average molecular weight Mn to design molecular weight M(th) (Mn / M(th)) of 0.7 to 1.3.

[0009] The present invention also provides a method for producing the above-mentioned polymer, which comprises obtaining a random copolymer or a block copolymer using two or more kinds of radically polymerizable monomers. Effect of the Invention

[0010] According to the present invention, a polymer having a desired molecular weight can be provided by preliminarily treating a disulfide compound with a radical initiator and then polymerizing a radically polymerizable monomer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will be described in detail below.

[0012] The production method of the present invention comprises the steps of: [ka] [wherein R1 and R2 each independently represent a substituted or unsubstituted aromatic hydrocarbon group, or a group represented by the formula: -SXA (wherein X represents a substituted or unsubstituted linear or branched alkylene group having 1 to 20 carbon atoms in which an oxygen atom may be present between the carbon bonds of the alkylene group, if possible, or a substituted or unsubstituted cyclic alkylene group having 3 to 12 carbon atoms, and A represents a hydrogen atom, an alkylamino group, an ester group, a vinyl group, or a substituted or unsubstituted aromatic hydrocarbon group)] The present invention is characterized in that a disulfide compound represented by the formula (I) is treated in advance with a radical initiator in a solvent or without a solvent, and then at least one radically polymerizable monomer is added to the treated product to carry out radical polymerization to produce a polymer.

[0013] The above phrase "treating a disulfide compound with a radical initiator in advance in a solvent or without a solvent, and then adding at least one type of radical polymerizable monomer to the treated product to polymerize" has the same meaning as "reacting a disulfide compound with a radical initiator in advance in a solvent or without a solvent, and then adding at least one type of radical polymerizable monomer to polymerize."

[0014] The "aromatic hydrocarbon group" in the present invention is a monovalent aromatic hydrocarbon group, and suitable examples thereof include, but are not limited to, phenyl, naphthyl, anthryl, and phenanthryl, among which phenyl is more preferred. These may be substituted with an appropriate substituent (e.g., alkyl, alkoxy, halogen, etc.).

[0015] Suitable examples of the "straight or branched alkylene group having 1 to 20 carbon atoms" in the present invention include methylene, ethylene, trimethylene, propylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, undecamethylene, dodecamethylene, tridecamethylene, tetradecamethylene, pentadecamethylene, hexadecamethylene, heptadecamethylene, octadecamethylene, nonadecamethylene, icosamethylene, ethylethylene, and dimethylethylene, among which methylene, ethylene, and dodecamethylene are more preferred. These may be substituted with an appropriate substituent (e.g., alkoxy, halogen, etc.).

[0016] In the term "a linear or branched alkylene group having 1 to 20 carbon atoms in which an oxygen atom may be present between carbon bonds of the alkylene group, if possible," the alkylene group has 2 to 20 carbon atoms in the case where an oxygen atom is present between carbon bonds of the alkylene group. Therefore, suitable examples of "straight-chain or branched-chain alkylene groups having 2 to 20 carbon atoms in which oxygen atoms are present between the carbon bonds of the alkylene groups" include, but are not limited to, diethylene oxide, di(trimethylene) oxide, dipropylene oxide, di(tetramethylene) oxide, di(pentamethylene) oxide, di(hexamethylene) oxide, di(heptamethylene) oxide, di(octamethylene) oxide, di(nonamethylene) oxide, di(decamethylene) oxide, ethylenemethylene oxide, triethylenedioxide, tripropylenedioxide, tri(trimethylene) dioxide, tetraethylenetrioxide, tetrapropylenetrioxide, pentaethylenetetraoxide, and hexaethylenepentoxide, with ethylenemethyleneoxide being more preferred. These may be substituted with appropriate substituents (e.g., alkoxy, halogen, etc.).

[0017] Suitable examples of the "cyclic alkylene group having 3 to 12 carbon atoms" in the present invention include, but are not limited to, cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, cycloheptalene, decahydronaphthylene, etc., which may be substituted with an appropriate substituent (for example, alkoxy, halogen, etc.).

[0018] Suitable examples of the alkyl group in the suitable substituent include, but are not limited to, linear or branched alkyl groups having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, pentyl, and hexyl.

[0019] Suitable examples of alkoxy in the appropriate substituents include, but are not limited to, linear or branched alkyloxy groups having 1 to 6 carbon atoms, such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, pentyloxy, and hexyloxy.

[0020] Halogen in the above suitable substituents includes fluorine, chlorine, bromine and iodine.

[0021] Suitable examples of the "straight-chain or branched-chain alkyl group having 1 to 20 carbon atoms" in the present invention include, but are not limited to, straight-chain alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, and icosyl, as well as branched-chain alkyl groups which are structural isomers thereof.

[0022] The "alkylamino group" in the present invention includes an amino group mono- or di-substituted with a straight-chain or branched-chain alkyl group having 1 to 20 carbon atoms, where the alkyl groups in the dialkyl may be the same or different. Preferred examples of the "alkylamino group" include, but are not limited to, methylamino, ethylamino, propylamino, isopropylamino, butylamino, pentylamino, neopentylamino, hexylamino, heptylamino, octylamino, nonylamino, decylamino, dimethylamino, diethylamino, dipropylamino, diisopropylamino, dibutylamino, dipentylamino, dineopentylamino, dihexylamino, diheptylamino, dioctylamino, dinonylamino, didecylamino, ethylmethylamino, methylpropylamino, and ethylpropylamino, and among these, diethylamino is more preferred.

[0023] The "ester group" in the present invention is represented by -COOR', where R' is the above-mentioned linear or branched alkyl group having 1 to 20 carbon atoms. As the alkyl group, methyl, ethyl, propyl and butyl are preferred, and butyl is more preferred.

[0024] The radical polymerizable monomer usable in the method for producing a polymer of the present invention can be selected from substituted or unsubstituted styrene, substituted or unsubstituted alkyl acrylate, substituted or unsubstituted alkyl methacrylate, acrylonitrile, N-alkyl alkyl amide, N-alkyl methacrylamide, N,N-dialkyl acrylamide, N,N-dialkyl methacrylamide, isoprene, butadiene, ethylene, vinyl acetate, and combinations thereof.

[0025] Specific examples of radical polymerizable monomers include methyl methacrylate, ethyl methacrylate, propyl methacrylate (including all isomers), butyl methacrylate (including all isomers), 2-ethylhexyl methacrylate, isobornyl methacrylate, methacrylic acid, benzyl methacrylate, phenyl methacrylate, methacrylonitrile, α-methylstyrene, methyl acrylate, ethyl acrylate, propyl acrylate (including all isomers), butyl acrylate (including all isomers), 2-ethylhexyl acrylate, isobornyl acrylate, acrylic acid, benzyl acrylate, phenyl acrylate, acrylonitrile, styrene, glycidyl methacrylate, 2-Hydroxyethyl methacrylate, Hydroxypropyl methacrylate (including all isomers), Hydroxybutyl methacrylate (including all isomers), N,N-Dimethylaminoethyl methacrylate, N,N-Diethylaminoethyl methacrylate, Triethylene glycol methacrylate, Itaconic anhydride, Itaconic acid, Glycidyl acrylate, 2-Hydroxyethyl acrylate, Hydroxypropyl acrylate (including all isomers), Hydroxybutyl acrylate (including all isomers), N,N-Dimethylaminoethyl acrylate, N,N-Diethylaminoethyl acrylate, Triethylene glycol acrylate, Methacrylamide, N-Methylacrylamide, N,N-Dimethylacrylamide, Nt-Butylmethacrylamide, Nn-Butylmethacrylamide, N-Methylolacrylamide, N-Ethylolacrylamide, 4-Acrylomorpholine, Vinylbenzoic acid (including all isomers), Diethylaminostyrene (including all isomers), α-Methylvinylbenzoic acid (including all isomers), Diethylaminoα-Methylstyrene (including all isomers), p-Vinylbenzenesulfonic acid, p-Vinylbenzenesulfonic acid sodium salt, Trimethoxysilylpropyl methacrylate, Triethoxysilylpropyl methacrylate, Tributoxysilylpropyl methacrylate acrylate, dimethoxymethylsilylpropyl methacrylate, diethoxymethylsilylpropyl methacrylate, dibutoxymethylsilylpropyl methacrylate, diisopropoxymethylsilylpropyl methacrylate, dimethoxysilylpropyl methacrylate, diethoxysilylpropyl methacrylate, dibutoxysilylpropyl methacrylate, diisopropoxysilylpropyl methacrylate, trimethoxysilylpropyl acrylate, triethoxysilylpropyl acrylate, tributoxysilylpropyl acrylate, diisopropoxysilylpropyl acrylate, maleic anhydride, N-phenylmaleimide, N-butylmaleimide, butadiene, isoprene, chloroprene, ethylene, vinyl acetate, and combinations thereof.

[0026] In the method for producing a polymer of the present invention, preferred radical polymerizable monomers include those selected from substituted or unsubstituted styrene, substituted or unsubstituted alkyl acrylates, substituted or unsubstituted alkyl methacrylates, N-alkyl acrylamides, N-alkyl methacrylamides, N,N-dialkyl acrylamides, N,N-dialkyl methacrylamides, and combinations thereof.

[0027] In the method for producing a polymer of the present invention, homopolymers, random copolymers and block copolymers can be produced by controlling the type and addition method of the radical polymerizable monomer.

[0028] In the method for producing a polymer of the present invention, a solvent may be further added. Examples of the solvent used in the polymerization include alcohols (alkyl alcohols such as ethanol, propanol, isopropanol, butanol, and isobutanol, glycols such as ethylene glycol and propylene glycol, etc.), hydrocarbons (aliphatic hydrocarbons such as hexane, alicyclic hydrocarbons such as cyclohexane, aromatic hydrocarbons such as toluene and xylene, etc.), halogenated hydrocarbons (methylene chloride, chloroform, etc.), ethers (chain ethers such as dimethyl ether and diethyl ether, cyclic ethers such as dioxane and tetrahydrofuran, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, ethyl lactate, ethyl butyrate, etc.), ketones (acetone, ethyl methyl ketone, methyl isobutyl ketone, cyclohexanone, N-methyl-2-pyrrolidone, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, ethyl cellosolve, etc.), and the like. Examples of organic solvents include ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, butyl carbitol acetate, etc., propylene glycol monoalkyl ethers (propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono n-butyl ether, etc.), glycol ether esters (ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, butyl carbitol acetate, etc.), amides (N,N-dimethylformamide, N,N-dimethylacetamide, etc.), sulfoxides (dimethyl sulfoxide, etc.), nitriles (acetonitrile, benzonitrile, etc.), and N-methylpyrrolidone. The organic solvent can be used alone or as a mixed solvent. From the viewpoint of the solubility of the disulfide compound, toluene, ethyl acetate, and tetrahydrofuran are preferred.

[0029] In the process for producing the polymer of the present invention, a radical initiator is an essential component. The radical initiator is not particularly limited, and various types can be used. The radical initiator may be a thermal polymerization initiator (thermal radical generator) or a photopolymerization initiator (photoradical generator).

[0030] Examples of the thermal polymerization initiator (thermal radical generator) include organic peroxides such as dialkyl peroxides (di-t-butyl peroxide, dicumyl peroxide, etc.), diacyl peroxides [dialkanoyl peroxides (lauroyl peroxide, etc.), diaroyl peroxides (benzoyl peroxide, benzoyl toluyl peroxide, toluyl peroxide, etc.)], peroxyesters [percarboxylate alkyl esters such as t-butyl peracetate, t-butyl peroxyoctoate, and t-butyl peroxybenzoate, etc.], ketone peroxides, peroxycarbonates, and peroxyketals; azonitrile compounds or azo compounds [2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methyl ... Bis(4-methoxy-2,4-dimethylvaleronitrile), dimethyl 2,2'-azobis(2-methylpropionate), 1,1'-azobis(cyclohexane-1-carbonitrile), 4,4'-azobis(4-cyanovaleric acid), etc.], azoamide compounds {2,2'-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide}, etc.}, azoamidine compounds {2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, etc.}, azoalkane compounds [2,2'-azobis(2,4,4-trimethylpentane), 4,4'-azobis(4-cyanopentanoic acid), etc.], azo compounds having an oxime skeleton [2,2'-azobis(2-methylpropionamide oxime), etc.], etc. The thermal polymerization initiator may be used alone or in combination of two or more kinds.

[0031] Examples of the photopolymerization initiator (photoradical generator) include benzoins (benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether); acetophenones (acetophenone, p-dimethylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, and the like); non, 2-phenyl-2-hydroxy-acetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, etc.); propiophenones (p-dimethylaminopropiophenone, 2-hydroxy-2-methyl-propiophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, etc.); butyrylphenones [1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, , 1-(4-isopropylphenyl)-2-hydroxy-2-methyl-propan-1-one, etc.]; aminoacetophenones [2-methyl-2-morpholino(4-thiomethylphenyl)propan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-dimethylamino-2-methyl-1-phenylpropan-1-one, 2-diethylamino-2-methyl-1-phenylpropan-1-one, on, 2-methyl-2-morpholino-1-phenylpropan-1-one, 2-dimethylamino-2-methyl-1-(4-methylphenyl)propan-1-one, 1-(4-butylphenyl)-2-dimethylamino-2-methylpropan-1-one, 2-dimethylamino-1-(4-methoxyphenyl)-2-methylpropan-1-one, 2-dimethylamino-2-methyl-1-(4-methylthiophenyl)propan-1-one, 2-benzyl-2-dimethylamino-1-(4-dimethylaminophenyl)-butan-1-one, etc.;Benzophenones (benzophenone, N,N'-bis(dimethylamino)benzophenone (Michler's ketone), 3,3-dimethyl-4-methoxybenzophenone, N,N'-dialkylaminobenzophenones such as benzil, etc.); ketals (acetophenone dimethyl ketal, benzil dimethyl ketal, etc.); thioxanthenes (thioxanthene, 2-chlorothioxanthene, 2,4-diethylthioxanthene, etc.); anthraquinones (2-ethylanthraquinone, 1-chloroanthraquinone, 1,2-benzanthraquinone, 2,3-diphenylanthraquinone, etc.); (thio)xanthones (thioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2 ,4-diisopropylthioxanthone, etc.; acridines (1,3-bis-(9-acridinyl)propane, 1,7-bis-(9-acridinyl)heptane, 1,5-bis-(9-acridinyl)pentane, etc.); triazines (2,4,6-tris(trichloromethyl)-s-triazine, 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-bis-trichloromethyl-6-(3-bromo-4-methoxy)styrylphenyl-s-triazine, etc.); sulfides (benzyldiphenyl sulfide, etc.); acylphosphine oxides (2,4,6-trimethylbenzoyldiphenylphosphine oxide, etc.); titanocene-based photopolymerization initiators; oxime esters, etc. can be exemplified. These photopolymerization initiators can be used alone or in combination of two or more. ;

[0032] In view of the polymerization temperature, 2,2'-azobis(isobutyronitrile), dimethyl 2,2'-azobis(2-methylpropionate), 1,1'-azobis(cyclohexane-1-carbonitrile), and 4,4'-azobis(4-cyanovaleric acid) are preferred.

[0033] The composition of the present invention may contain various additives if necessary. Examples of additives include thermal polymerization inhibitors (hydroquinone, hydroquinone monoethyl ether, etc.), defoamers, coating improvers, thickeners, lubricants, stabilizers (antioxidants, heat stabilizers, light resistance stabilizers, etc.), plasticizers, surfactants, dissolution promoters, colorants, fillers, antistatic agents, silane coupling agents, leveling agents, dispersants, and dispersion assistants. The additives may be used alone or in combination of two or more.

[0034] The production conditions of the production method of the present invention for producing a polymer by treating the disulfide compound of the formula (1) with a radical initiator in advance in a solvent or without a solvent, and then adding at least one kind of radically polymerizable monomer to the treated product to carry out radical polymerization will be described. All treatments and polymerizations are preferably carried out under an inert gas atmosphere (eg, nitrogen, etc.).

[0035] The conditions for treating the disulfide compound with a radical initiator are as follows. The disulfide compound is used in an amount of preferably 0.1 to 50 parts by mass, more preferably 1 to 10 parts by mass, based on 100 parts by mass of the radical polymerizable monomer.

[0036] When a solvent is used, the solvent is preferably used in an amount of 1 to 200 parts by mass, more preferably 30 to 100 parts by mass, based on 100 parts by mass of the radical polymerizable monomer. The radical initiator is preferably used in an amount of 0.1 to 50 parts by mass, more preferably 1 to 5 parts by mass, based on 100 parts by mass of the radical polymerizable monomer. In this treatment, the radical initiator may be used in excess, in which case the excess radical initiator may act as a radical polymerization initiator in the polymerization with the radically polymerizable monomer following this treatment.

[0037] The treatment temperature is preferably from -20 to 200°C, more preferably from 50 to 90°C. The treatment time is preferably 0.1 to 100 hours, more preferably 1 to 5 hours.

[0038] Following the above treatment, the polymerization conditions for polymerizing at least one radically polymerizable monomer are as follows: The polymerization is preferably carried out using a radical polymerization initiator, and examples of the radical polymerization initiator include the radical initiators described above. The radical polymerization initiator is used in an amount of preferably 0.1 to 10 parts by mass, more preferably 0.4 to 1 part by mass, based on 100 parts by mass of the radical polymerizable monomer. The polymerization temperature is preferably from 5 to 200°C, more preferably from 50 to 130°C. The polymerization time is preferably 0.1 to 100 hours, more preferably 1 to 20 hours.

[0039] By the above polymerization method, it is possible to obtain a polymer having a number average molecular weight Mn of 500 to 1,000,000 and a ratio of weight average molecular weight Mw to number average molecular weight Mn (Mw / Mn) of 1.0 to 5.0.

[0040] In the method of the present invention in which a disulfide compound of the present invention is preliminarily treated with a radical initiator and then a radically polymerizable monomer is added to the treated product to carry out radical polymerization, the ratio [Mn / M(th)] of the number average molecular weight Mn to the design molecular weight M(th) of the polymer obtained by a conventional method in which a disulfide compound, a radical initiator, and a radically polymerizable monomer are added all at once and polymerized is 1.7 or more, can be set to less than 1.7, or even 1.5 or less, and particularly 0.7 to 1.3. This means that it is possible to obtain a polymer of the desired molecular weight.

[0041] The reason why a polymer with the desired molecular weight can be obtained is believed to be that when a disulfide compound is treated in advance with a radical initiator as shown in the following general formula (2), the radical (I·) generated from the radical initiator does not contain a radical polymerizable monomer and reacts only with the disulfide compound to generate two molecules of a compound that acts as a RAFT agent. Then, the two molecules of the RAFT agent react with the radical polymerizable monomer (M) to obtain a polymer with the desired designed molecular weight.

[0042] [ka]

[0043] In contrast, when a disulfide compound, a radical initiator, and a radically polymerizable monomer are added all at once and polymerized, as shown in the following general formula (3), the growing end radical (Pn·) formed by the reaction of the radical (I·) generated from the radical initiator with the radically polymerizable monomer (M) reacts with the disulfide compound, and the generated compound (a) functions as a RAFT agent. However, the generated thiocarbonylthio radical (b) does not function as a RAFT agent even when it reacts with the radically polymerizable monomer. As a result, one molecule of a compound that functions as a RAFT agent is generated from one molecule of the disulfide compound, and it is thought that a polymer with a molecular weight twice the designed molecular weight is generated.

[0044] [ka] EXAMPLES

[0045] The present invention will be described in detail below with reference to Synthesis Examples, Examples, and Comparative Examples, but the present invention is not limited to these Synthesis Examples, Examples, and Comparative Examples. The following apparatuses were used to measure the physical properties in each Synthesis Example, Example, and Comparative Example.

[0046] [Molecular weight measurement] Using a gel permeation chromatograph (LC-20A, manufactured by Shimadzu Corporation), the number average molecular weight (Mn) and weight average molecular weight (Mw) were measured in terms of polystyrene under the following conditions. The molecular weight distribution (Mw / Mn) was calculated from the obtained values. Measurement conditions Column: Tosoh TSKgel SuperMultiporeHZ-M x 1 Column temperature: 40℃ Eluent: Tetrahydrofuran Detector: RI

[0047] [Liquid chromatography (LC) measurement] The measurement was carried out using a liquid chromatography apparatus (GL-7480, manufactured by GL Sciences) under the following conditions. Measurement conditions Column: Inertsil ODS-2 Column temperature: 40℃ Eluent: Tetrahydrofuran / acetonitrile 20 / 80 (v / v) 1 ml / min Detector: UV, 300nm

[0048] [Gas chromatography (GC) measurement] The measurements were carried out using a gas chromatograph (GC-2014, manufactured by Shimadzu Corporation) under the following conditions. Measurement conditions Column: HP-1 10m, inner diameter 0.530mm, film thickness 2.65μm Oven: 80℃ 1 min, 10℃ / min, 300℃ 5 min Injection temperature: 280℃ Detector: Flame ionization detector Detector temperature: 300℃

[0049] [Synthesis Example 1] Synthesis of bis(n-dodecylmercapto-thiocarbonyl) disulfide [ka]

[0050] A reaction solution was prepared by adding 101g of n-dodecyl mercaptan, 46g of carbon disulfide, and 200g of tetrahydrofuran to a 1L flask equipped with a reflux condenser, a thermometer, and a stirrer. 58g of 48% aqueous potassium hydroxide solution was added dropwise using a dropping funnel. During the dropwise addition, the mixture was cooled in a water bath so that the internal temperature was 40°C or less. After the dropwise addition, the mixture was stirred and reacted for 1 hour. A solution in which 64g of iodine was dissolved in 22g of tetrahydrofuran was added dropwise. This time, the mixture was also cooled in a water bath and the internal temperature was adjusted to 40°C or less. After the dropwise addition, the mixture was reacted for 1 hour, and then 100g of water and 100g of toluene were added and the mixture was separated. The upper layer was further washed with 81g of 2% sodium sulfite water, and then washed twice with 80g of water. After the separation, the toluene was removed from the upper layer using an evaporator, and 250g of methylmethanol and 60g of toluene were added thereto and stirred for 4 hours under cooling at 5°C to precipitate crystals. The precipitated crystals were filtered and dried under reduced pressure at 30° C. or less to obtain 127 g of the titled bis(n-dodecylmercapto-thiocarbonyl) disulfide (yield 91%). The purity determined by liquid chromatography analysis was 97%.

[0051] [Synthesis Example 2] Synthesis of bis(thiobenzoyl) disulfide [ka]

[0052] 4.9g of magnesium was put into a 1L flask equipped with a reflux condenser, a thermometer, a nitrogen sealing tube and a stirrer, and a mixture of 31g of phenyl bromide and 140g of tetrahydrofuran was dropped into the flask using a dropping funnel under a nitrogen atmosphere. At this time, the internal temperature was adjusted to 40-50°C using a water bath or air cooling. After the dropwise addition, the mixture was stirred and reacted for 2 hours. A mixture of 15g of carbon disulfide and 10g of tetrahydrofuran was dropped into the flask. At this time, the mixture was cooled in a water bath and adjusted to an internal temperature of 40°C or less. After stirring and reacting for 1 hour, a solution of 25g of iodine dissolved in 35g of tetrahydrofuran was dropped into the flask. After stirring and reacting for 1 hour, 120g of water and 115g of toluene were added and the mixture was separated. The upper layer was washed with 120g of water, washed twice with 100g of 5% sodium sulfite, and washed twice with 100g of water. Toluene was removed from the upper layer using an evaporator, 47 g of ethyl acetate was added, and the mixture was cooled to 5° C. to precipitate crystals. The precipitated crystals were filtered and dried under reduced pressure at 30° C. to obtain 21 g of the title bis(thiobenzoyl)disulfide (yield 69%). The purity determined by liquid chromatography analysis was 85%.

[0053] [Example 1] A 200 ml flask equipped with a reflux condenser, a thermometer, a nitrogen inlet tube and a stirrer was replaced with nitrogen, and 4.3 parts by mass of bis(n-dodecylmercapto-thiocarbonyl) disulfide, 50 parts by mass of toluene and 1.5 parts by mass of azobisisobutyronitrile were placed in the flask as a disulfide compound, and reacted at 90° C. for 2 hours. Then, 100 parts by mass of butyl acrylate as a polymerization component, 0.4 parts by mass of azobisisobutyronitrile as a radical initiator and 50 parts by mass of toluene were added to the reaction liquid to obtain a composition for radical polymerization. Next, the flask containing the composition for polymerization was heated to 75° C. for 2 hours using an oil bath while stirring under a nitrogen stream, and radical polymerization was performed. After the polymerization reaction was completed, the mixture was returned to room temperature and analyzed. The conversion of butyl acrylate determined by gas chromatography (GC) was 94%, and the number average molecular weight (Mn) determined by gel permeation chromatography (GPC) was 7,700 and the polydispersity (Mw / Mn) was 1.08.

[0054] [Example 2] As in Example 1, a composition consisting of 5.6 parts by mass of bis(n-dodecylmercapto-thiocarbonyl) disulfide, 50 parts by mass of toluene, and 2 parts by mass of azobisisobutyronitrile was reacted at 90°C for 2 hours, and then 100 parts by mass of methyl methacrylate, 0.5 parts by mass of azobisisobutyronitrile, and 50 parts by mass of toluene were added to the reaction liquid to prepare a composition for radical polymerization. The mixture was heated at 75°C for 6 hours to carry out radical polymerization. After the polymerization reaction was completed, the mixture was returned to room temperature and analyzed. The conversion rate of methyl methacrylate determined by GC was 84%, Mn determined by GPC was 5,600, and Mw / Mn was 1.18.

[0055] [Example 3] As in Example 1, 3.1 parts by mass of bis(thiobenzoyl) disulfide, 50 parts by mass of toluene, and 2 parts by mass of azobisisobutyronitrile were reacted at 90°C for 2 hours, and then 100 parts by mass of methyl methacrylate, 0.5 parts by mass of azobisisobutyronitrile, and 50 parts by mass of toluene were added to the reaction solution to prepare a composition for radical polymerization. The mixture was heated at 75°C for 9 hours to carry out radical polymerization. After the polymerization reaction was completed, the mixture was returned to room temperature and analyzed. The conversion rate of methyl methacrylate determined by GC was 85%, Mn determined by GPC was 5,100, and Mw / Mn was 1.14.

[0056] [Example 4] As in Example 1, 2.4 parts by mass of bis(thiobenzoyl) disulfide, 50 parts by mass of toluene, and 1.5 parts by mass of azobisisobutyronitrile were reacted at 90°C for 2 hours, and then 100 parts by mass of butyl acrylate, 0.4 parts by mass of azobisisobutyronitrile, and 50 parts by mass of toluene were added to the reaction solution to obtain a composition for radical polymerization. The composition was heated at 75°C for 20 hours to carry out radical polymerization. After the polymerization reaction was completed, the mixture was returned to room temperature and analyzed. The conversion rate of butyl acrylate determined by GC was 88%, and Mn determined by GPC was 6,700, and Mw / Mn was 1.15.

[0057] [Comparative Example 1] A 200 ml flask equipped with a reflux condenser, a thermometer, a nitrogen inlet tube and a stirrer was replaced with nitrogen, and 4.3 parts by mass of bis(n-dodecylmercapto-thiocarbonyl) disulfide as a disulfide compound, 100 parts by mass of toluene as a polymerization solvent, 100 parts by mass of butyl acrylate as a polymerization component and 0.4 parts by mass of azobisisobutyronitrile as a radical initiator were placed in the flask to obtain a composition for radical polymerization. Next, under a nitrogen stream, the flask containing the composition for polymerization was heated at 75° C. for 4 hours using an oil bath while stirring, and radical polymerization was performed. After the polymerization reaction was completed, the temperature was returned to room temperature and analysis was performed. The conversion rate of butyl acrylate determined by GC was 94%, Mn determined by GPC was 17,200, and Mw / Mn was 1.15.

[0058] [Comparative Example 2] As in Comparative Example 1, a composition for radical polymerization consisting of 5.5 parts by mass of bis(n-dodecylmercapto-thiocarbonyl) disulfide, 100 parts by mass of toluene, 100 parts by mass of methyl methacrylate, and 0.5 parts by mass of azobisisobutyronitrile was heated at 75°C for 6 hours to carry out radical polymerization. After the polymerization reaction was completed, the temperature was returned to room temperature and analysis was carried out. The conversion rate of methyl methacrylate determined by GC was 90%, Mn determined by GPC was 9,500, and Mw / Mn was 1.11.

[0059] [Comparative Example 3] As in Comparative Example 1, a composition for radical polymerization consisting of 3.1 parts by mass of bis(thiobenzoyl)disulfide, 100 parts by mass of toluene, 100 parts by mass of methyl methacrylate, and 1.3 parts by mass of azobisisobutyronitrile was heated at 75°C for 9 hours to carry out radical polymerization. After the polymerization reaction was completed, the mixture was returned to room temperature and analyzed. The conversion rate of methyl methacrylate determined by GC was 83%, Mn determined by GPC was 7,600, and Mw / Mn was 1.30.

[0060] [Comparative Example 4] As in Comparative Example 1, a composition for radical polymerization consisting of 2.4 parts by mass of bis(thiobenzoyl)disulfide, 100 parts by mass of toluene, 100 parts by mass of butyl acrylate, and 1.6 parts by mass of azobisisobutyronitrile was heated at 75°C for 20 hours to carry out radical polymerization. After the polymerization reaction was completed, the mixture was returned to room temperature and analyzed. The conversion rate of butyl acrylate determined by GC was 90%, and Mn determined by GPC was 11,500, with Mw / Mn being 1.23.

[0061] The blending formulations of the polymer compositions and the polymerization results of the above-mentioned Examples and Comparative Examples are summarized in Table 1 below. [Table 1] * "Sequential" refers to reacting a disulfide compound with a radical initiator in advance, and then adding a radical polymerizable monomer to polymerize. "All at once" refers to polymerizing a disulfide compound, a radical initiator, and a radical polymerizable monomer all at once. *The designed molecular weight M(th) is a value calculated by [(the molar ratio of radical polymerizable monomer to disulfide compound) × (molecular weight of radical polymerizable monomer) × 0.5 × (monomer conversion)] + (molecular weight of effective RAFT agent). §Mn / M(th) is the ratio of the number average molecular weight Mn determined by GPC measurement to the designed molecular weight M(th).

[0062] The results in Table 1 show that in Examples 1 to 4, in which the disulfide compound, the radical initiator, and the monomer were reacted successively, the number average molecular weight Mn and the designed molecular weight M(th) were almost the same value, and the ratio [Mn / M(th)] was 1.1 to 1.2. In contrast, in Comparative Examples 1 to 4, in which the disulfide compound, the radical initiator, and the monomer were reacted in a lump, the Mn / M(th) was 1.7 to 2.7, and a polymer having a molecular weight 2 to 3 times higher than the desired molecular weight was obtained. This indicates that half of the disulfide compound does not function as a RAFT agent in the polymerization method of the lump-sum reaction in the Comparative Examples. [Industrial Applicability]

[0063] The method for producing a polymer of the present invention can be widely applied in the field of free radical polymerization of radical polymerizable monomers such as methacrylates, acrylates, and styrenes. For example, it can be suitably used in the field of adhesives such as adhesives for protective sheets, or as photoresist polymers and sealants. Furthermore, block, star, and branched polymers can be used as thermoplastic elastomers, pigment dispersants for paints, rheology modifiers, and the like.

Claims

1. A compound represented by the following general formula (1): 【Chemistry 1】 [In the formula, R １ and R ２ are each independently a substituted or unsubstituted aromatic hydrocarbon group, is represented by the formula: -SXA (wherein X is an oxygen atom, if possible, at the carbon bond of an alkylene group). A substituted or unsubstituted linear or branched alkyl group having 1 to 20 carbon atoms may be present between the A represents a cycloalkylene group or a substituted or unsubstituted cyclic alkylene group having 3 to 12 carbon atoms; A substituted or unsubstituted aromatic hydrocarbon. represents a radical] and 0.1 to 50 parts by mass of a disulfide compound represented by the formula (I) and 0.1 to 50 parts by mass of a radical initiator are reacted in advance in 1 to 200 parts by mass of a solvent under conditions of a temperature of −20 to 200° C. and a treatment time of 0.1 to 100 hours, and then at least one radically polymerizable monomer is added to the reaction liquid and radically polymerized under conditions of a polymerization temperature of 5 to 200° C. and a polymerization time of 0.1 to 100 hours (excluding the purification of the RAFT agent from the reaction liquid), A method for producing a polymer, which obtains a polymer having a number average molecular weight Mn of 500 to 1,000,000, a ratio of weight average molecular weight Mw to number average molecular weight Mn (Mw / Mn) of 1.0 to 5.0, and a ratio of number average molecular weight Mn to design molecular weight M(th) (Mn / M(th)) of 0.7 to 1.

3.

2. 2. The method for producing a polymer according to claim 1, wherein a random copolymer or a block copolymer is obtained by using two or more kinds of radically polymerizable monomers.

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