Method for producing block copolymer

Abstract

To provide a method for producing a block copolymer, which enables easy operations such as taking out a reaction product from a reaction system after reaction and which enables obtaining a block copolymer having a high molecular weight and a controlled molecular weight distribution.SOLUTION: A method for producing a copolymer, that includes an A block having a structural unit derived from a vinyl monomer (a) and a B block having a structural unit derived from a vinyl monomer (b), comprises: a first step of subjecting a vinyl monomer (a) to living radical polymerization and preparing a macro chain transfer agent (X); and a second step of mixing the macro chain transfer agent (X), a vinyl monomer (b), and a solvent (Y) and subjecting the mixture to living radical polymerization, where the difference (SP2-SP1) between the SP value (SP2) of the vinyl monomer (a) and the SP value (SP1) of the solvent (Y) is -1.5 to 1.5, and the difference (SP3-SP1) between the SP value (SP3) of the vinyl monomer (b) and the SP value (SP1) of the solvent (Y) is 2 or more.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for producing a block copolymer.

Background Art

[0002] The living radical polymerization method is a polymerization method that enables precise control of the molecular structure and production of a polymer with a uniform composition while maintaining the simplicity and versatility of the conventional radical polymerization method, and exerts great power in the production of new polymer materials. Therefore, in recent years, the development of living radical polymerization technology has been remarkable, and various living radical polymerization methods have been reported.

[0003] For example, a method using a compound capable of generating a nitroxide radical (nitroxide method; NMP method); a method of living polymerization from a polymerization initiator compound using a metal complex such as copper or ruthenium and using a halogenated compound as a polymerization initiator compound (ATRP method); a method using a dithiocarboxylic acid ester or a xanthate compound (RAFT method); a method using an organic tellurium compound (TERP method); a method using an organic iodine compound (ITP method); a method using an iodine compound as a polymerization initiator compound and using an organic compound such as a phosphorus compound, a nitrogen compound, an oxygen compound, or a hydrocarbon as a catalyst (reversible transfer catalyst polymerization; RTCP method, reversible catalyst-mediated polymerization; RCMP method), etc. have been reported. Among them, the living radical polymerization method is useful for the production of block copolymers.

[0004] As an example of a block copolymer, an amphiphilic block copolymer having a hydrophilic block composed of a hydrophilic monomer (for example, a monomer having a carboxy group) and a hydrophobic block composed of a hydrophobic monomer is known. For example, Patent Document 1 discloses a method for producing a (poly(n-butyl acrylate))-b-(poly(acrylic acid)) diblock copolymer in an alcohol solvent by the RAFT method.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2007-504311 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] However, in the living radical polymerization method such as Patent Document 1, as the polymerization proceeds, the viscosity of the reaction system increases, so that operations such as extraction of reactants may become difficult, and polymerization control is also difficult.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for producing a block copolymer in which operations such as extraction of reactants from the reaction system after the reaction are easy, and a block copolymer having a high molecular weight and a controlled molecular weight distribution can be obtained. [Means for Solving the Problems]

[0008] The present invention provides a method for producing a block copolymer and a dispersion of amphiphilic block copolymer fine particles obtained by the method for producing a block copolymer.

[0009] Item 1 A method for producing a block copolymer comprising an A block having a structural unit derived from a vinyl monomer (a) and a B block having a structural unit derived from a vinyl monomer (b), comprising: a first step of subjecting the vinyl monomer (a) to living radical polymerization and preparing a macro chain transfer agent (X); and a second step of mixing the macro chain transfer agent (X), the vinyl monomer (b) and a solvent (Y) and subjecting them to living radical polymerization, wherein a difference (SP2 - SP1) between an SP value (SP2) of the vinyl monomer (a) and an SP value (SP1) of the solvent (Y) is -1.5 to 1.5, and a difference (SP3 - SP1) between an SP value (SP3) of the vinyl monomer (b) and an SP value (SP1) of the solvent (Y) is 2 or more.

[0010] Item 2. The method for producing a block copolymer according to Item 1, wherein the amount of the vinyl monomer (b) present in the reaction system of the second step is 50 mol or more and 1000 mol or less per 1 mol of the macro chain transfer agent (X).

[0011] Item 3. The method for producing a block copolymer according to Item 1 or Item 2, wherein the weight average molecular weight of the macro chain transfer agent (X) is 1000 or more and 50000 or less.

[0012] Item 4. The method for producing a block copolymer according to any one of Items 1 to 3, wherein the SP value (SP2) of the vinyl monomer (a) is smaller than the SP value (SP3) of the vinyl monomer (b).

[0013] Item 5. The method for producing a block copolymer according to any one of Items 1 to 4, wherein the vinyl monomer (a) is at least one vinyl monomer selected from the group consisting of (meth)acrylates having an alkyl group, (meth)acrylates having an aryl group, and styrene-based monomers.

[0014] Item 6. The method for producing a block copolymer according to any one of Items 1 to 5, wherein the vinyl monomer (b) is at least one vinyl monomer selected from the group consisting of vinyl monomers having an acidic group, vinyl monomers having a nitrogen-containing functional group, (meth)acrylates having a hydroxy group, and (meth)acrylamides.

[0015] Item 7. The method for producing a block copolymer according to any one of Items 1 to 6, wherein the solvent (Y) is a hydrophobic organic solvent.

[0016] Item 8. The method for producing a block copolymer according to any one of Items 1 to 7, wherein the SP value (SP1) of the solvent (Y) is less than 10.0.

[0017] Item 9. The method for producing a block copolymer according to any one of Items 1 to 8, wherein the block copolymer is an A-B type diblock copolymer.

[0018] Item 10. The method for producing a block copolymer according to any one of Items 1 to 9, wherein the living radical polymerization in the first step is a living radical polymerization using an organic tellurium compound represented by the following general formula (1).

[0019] R 11 -Te-C-R 12 R 13 R 14 …Formula (1) 〔In the general formula (1), R 11 is an alkyl group, aryl group or aromatic heterocyclic group having 1 to 8 carbon atoms. R 12 and R 13 are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. R 14 is an alkyl group, aryl group, substituted aryl group, aromatic heterocyclic group, alkoxy group, acyl group, amide group, oxycarbonyl group, cyano group, allyl group or propargyl group having 1 to 8 carbon atoms.〕

[0020] Item 11. A dispersion of amphiphilic block copolymer fine particles obtained by the method for producing a block copolymer according to any one of Items 1 to 10.

Advantages of the Invention

[0021] According to the present invention, it is possible to provide a method for producing a block copolymer in which operations such as extraction of reaction products from the reaction system after the reaction are easy, and a block copolymer having a high molecular weight and a controlled molecular weight distribution can be obtained.

Embodiments for Carrying Out the Invention

[0022] Hereinafter, an example of a preferred embodiment in which the present invention is implemented will be described. However, the following embodiments are merely illustrative. The present invention is not limited to the following embodiments at all.

[0023] The method for producing a block copolymer of the present invention (hereinafter also referred to as "the present production method") is a method for producing a block copolymer (hereinafter also simply referred to as "block copolymer") including an A block having a structural unit derived from a vinyl monomer (a) and a B block having a structural unit derived from a vinyl monomer (b).

[0024] The present production method includes a first step of subjecting a vinyl monomer (a) to living radical polymerization to prepare a macro chain transfer agent (X), and a second step of mixing the macro chain transfer agent (X), a vinyl monomer (b), and a solvent (Y) and subjecting them to living radical polymerization. The difference (SP2 - SP1) between the SP value (SP2) of the vinyl monomer (a) and the SP value (SP1) of the solvent (Y) is -1.5 to 1.5, and the difference (SP3 - SP1) between the SP value (SP3) of the vinyl monomer (b) and the SP value (SP1) of the solvent (Y) is 2 or more.

[0025] According to the method for producing a block copolymer of the present invention, operations such as extraction of reaction products from the reaction system after the reaction are easy, and a block copolymer having a high molecular weight and a controlled molecular weight distribution can be obtained in a short time.

[0026] A macro chain transfer agent is a polymer obtained by subjecting a vinyl monomer to living radical polymerization and has a functional group having a living radical polymerization ability at the growing end of the polymer, so it can be used as a chain transfer agent for living radical polymerization. The macro chain transfer agent (X) prepared in the first step is a polymer having a structural unit derived from a vinyl monomer (a) and has a functional group having a living radical polymerization ability at the end of the polymer.

[0027] Since the macro chain transfer agent (X) has a functional group with living radical polymerization ability at the growth end of the polymer, it is used as a chain transfer agent for living radical polymerization of vinyl monomer (b) in solvent (Y). The macro chain transfer agent (X) is a polymer having a structural unit derived from vinyl monomer (a). Since vinyl monomer (a) has a smaller SP value than vinyl monomer (b), the polymer block (A block) formed from the macro chain transfer agent (X) corresponds to a relatively highly hydrophobic block. In contrast, the polymer block (B block) having a structural unit derived from vinyl monomer (b) corresponds to a relatively highly hydrophilic block. In the present invention, it is preferable that the polymer block (A block) formed from the macro chain transfer agent (X) is a hydrophobic block and the polymer block (B block) having a structural unit derived from vinyl monomer (b) is a hydrophilic block.

[0028] Since the macro chain transfer agent (X) has an SP value close to that of the solvent (Y), it can mediate the polymerization of vinyl monomer (b) in the solvent (Y). When the polymerization of the relatively highly hydrophilic vinyl monomer (b) proceeds and the B block reaches a certain molar mass, the portion of the B block becomes insoluble in the solvent (Y) and forms particles swollen with self-assembled vinyl monomer (b). There is still a functional group with living radical polymerization ability at the growth end of the block copolymer (the end of the B block), which continues at the center of the obtained self-stabilized particles. This process gives stability to the particles without the need for a surfactant and also makes it difficult for the viscosity of the reaction system to increase. Therefore, operations such as extracting the reaction product (block copolymer) from the reaction system after the reaction are easy, and it also becomes easy to produce a block copolymer with a high molecular weight and a controlled molecular weight distribution. In contrast, in conventional solution polymerization, as the polymerization proceeds with the polymer remaining dissolved, the viscosity of the reaction system increases as the molecular weight increases, making it difficult to perform operations such as extracting the reaction product (block copolymer) from the reaction system, and it is difficult to obtain a block copolymer with a high molecular weight and a controlled molecular weight distribution.

[0029] In this specification, "A block" can be rephrased as "A segment", and "B block" can be rephrased as "B segment". "Vinyl monomer" refers to a monomer having a carbon-carbon double bond capable of radical polymerization in the molecule. "Structural unit derived from vinyl monomer" refers to a structural unit in which the carbon-carbon double bond capable of radical polymerization of the vinyl monomer has polymerized to form a carbon-carbon single bond. "(Meth)acrylic" refers to "at least one of acrylic and methacrylic". "(Meth)acrylate" refers to "at least one of acrylate and methacrylate". "(Meth)acryloyl" refers to "at least one of acryloyl and methacryloyl".

[0030] <First step> In the first step, vinyl monomer (a) is subjected to living radical polymerization to prepare a macro chain transfer agent (X).

[0031] The macro chain transfer agent (X) is a polymer having a structural unit derived from vinyl monomer (a), and has a functional group having living radical polymerization ability at the end of the polymer. In living radical polymerization, when two or more vinyl monomers (a) are used, the polymer may have a block structure, but is preferably a random structure from the viewpoint of solubility in solvent (Y).

[0032] Examples of the functional group having living radical polymerization ability include, for example, -Te-R 11 , -Cl, -Br, -I, -SC(=S)R 11 , -SC(=S)OR 11 , -S(C=S)NR 11 2 etc. are mentioned. Among these, from the viewpoint of the diversity of monomers that can be used, the functional group having living radical polymerization ability is preferably -Te-R 11 . R 11 is an alkyl group, aryl group or aromatic heterocyclic group having 1 to 8 carbon atoms.

[0033] The molecular weight of the macro chain transfer agent (X) is measured by gel permeation chromatography (hereinafter referred to as "GPC"). The weight average molecular weight (Mw) of the macro chain transfer agent (X) is preferably 1,000 or more, more preferably 7,500 or more, still more preferably 10,000 or more, and preferably 50,000 or less, more preferably 35,000 or less, still more preferably 25,000 or less. If Mw is within the above range, the polymerization controllability when used as the macro chain transfer agent (X) will be better.

[0034] The molecular weight distribution (Mw / Mn) of the macro chain transfer agent (X) is preferably 2.0 or less, more preferably 1.8 or less, still more preferably 1.6 or less. In this specification, the molecular weight distribution (Mw / Mn) of the macro chain transfer agent (X) is obtained by (weight average molecular weight (Mw) of the macro chain transfer agent (X)) / (number average molecular weight (Mn) of the macro chain transfer agent (X)). The smaller the Mw / Mn, the narrower the molecular weight distribution width, and the polymer has a more uniform molecular weight. When the value is 1.0, the molecular weight distribution width is the narrowest. That is, the lower limit value of Mw / Mn is 1.0. On the other hand, when the molecular weight distribution (Mw / Mn) of the macro chain transfer agent (X) exceeds 2.0, it will contain those with a small molecular weight or a large molecular weight.

[0035] (Vinyl monomer (a)) The vinyl monomer (a) is a vinyl monomer having a smaller SP value than the vinyl monomer (b), and the difference (SP2 - SP1) between the SP value (SP2) of the vinyl monomer (a) and the SP value (SP1) of the solvent (Y) is -1.5 to 1.5. SP2 - SP1 is preferably 0 to 1.5, more preferably 0.5 to 1.5, still more preferably 1.0 to 1.5. When (SP2 - SP1) is within the above range, the macro chain transfer agent (X) formed from the vinyl monomer (a) can be dissolved in the solvent (Y).

[0036] The vinyl monomer (a) can include, for example, (meth)acrylates having an alkyl group, (meth)acrylates having an aryl group, styrene-based monomers, etc. These can be used individually or in combination of two or more.

[0037] Examples of the (meth)acrylate having the above alkyl group include (meth)acrylates having a linear alkyl group, (meth)acrylates having a branched alkyl group, (meth)acrylates having a cyclic alkyl group with a monocyclic structure, and (meth)acrylates having a cyclic alkyl group with a bridged ring structure.

[0038] The (meth)acrylate having the above linear alkyl group is preferably a (meth)acrylate having a linear alkyl group with 1 to 20 carbon atoms, and more preferably a (meth)acrylate having a linear alkyl group with 1 to 12 carbon atoms. Specific examples of the (meth)acrylate having the above linear alkyl group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, n-lauryl (meth)acrylate, n-stearyl (meth)acrylate, etc.

[0039] As the (meth)acrylate having the branched-chain alkyl group, it is preferably a (meth)acrylate having a branched-chain alkyl group with 3 to 20 carbon atoms in the branched-chain alkyl group, and more preferably a (meth)acrylate having a branched-chain alkyl group with 3 to 12 carbon atoms in the branched-chain alkyl group. Specific examples of the (meth)acrylate having the branched-chain alkyl group include isopropyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, and the like.

[0040] As the (meth)acrylate having the cyclic alkyl group of the monocyclic structure, it is preferably a (meth)acrylate having a cyclic alkyl group of the monocyclic structure with 6 to 20 carbon atoms in the cyclic alkyl group of the monocyclic structure, and more preferably a (meth)acrylate having a cyclic alkyl group of the monocyclic structure with 6 to 12 carbon atoms in the cyclic alkyl group of the monocyclic structure. Specific examples of the (meth)acrylate having the cyclic alkyl group of the monocyclic structure include cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, cyclododecyl (meth)acrylate, 3,3,5-(trimethyl)cyclohexyl (meth)acrylate, 4-(tert-butyl)cyclohexyl (meth)acrylate, and the like.

[0041] Examples of the (meth)acrylate having a cyclic alkyl group with the above-mentioned bridged ring structure include (meth)acrylates having a cyclic alkyl group with a bridged ring structure and having 6 to 20 carbon atoms in the cyclic alkyl group with the bridged ring structure, preferably (meth)acrylates having a cyclic alkyl group with a bridged ring structure and having 6 to 12 carbon atoms in the cyclic alkyl group with the bridged ring structure. Specific examples of the (meth)acrylate having a cyclic alkyl group with a bridged ring structure include isobornyl (meth)acrylate, dicyclopentenyl oxyethyl (meth)acrylate, dicyclopentanyl oxyethyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, 2-ethyl-2-adamantyl (meth)acrylate and the like.

[0042] Examples of the (meth)acrylate having the above-mentioned aryl group include (meth)acrylates having an aryl group with 6 to 12 carbon atoms in the aryl group. The aryl group may have a chain portion such as an alkylaryl group, an arallyl group, an aryloxyalkyl group and the like. That is, examples of the (meth)acrylate having an aryl group include compounds in which an aryl group is directly bonded to a (meth)acryloyloxy group, compounds in which an aralkyl group is directly bonded to a (meth)acryloyloxy group, and compounds in which an alkylaryl group is directly bonded to a (meth)acryloyloxy group. Specific examples of the (meth)acrylate having the above-mentioned aryl group include, for example, benzyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate and the like.

[0043] The above styrenic monomer can include substituted or unsubstituted styrene. Examples of substituents that may substitute styrene include an alkyl group, an aryl group, an ether group, etc. The styrenic monomer also includes a condensed cyclic compound having two or more benzene rings. Specific examples of the above styrenic monomer include styrene, α-methylstyrene, 4-methylstyrene, 2-methylstyrene, 3-methylstyrene, 2,4-dimethylstyrene, 4-methoxystyrene, 4-phenylstyrene, 1-vinylnaphthalene, etc.

[0044] The SP value (solubility parameter) of the vinyl monomer (a) is a value calculated by the Fedors method, and the unit is (cal / cm 3 ) 1 / 2 Specifically, it can be calculated by the calculation method described in "Polymer Engineering and Science" 14(2), 147(1974) written by R.F. Fedors. More specifically, it is by the calculation method shown in the following formula (2).

[0045]

Equation

[0046] When using a combination of two or more vinyl monomers as the vinyl monomer (a), calculate the SP value of each vinyl monomer used by the above method, and the value obtained by adding and averaging the SP values of each vinyl monomer based on the mass fraction of the total amount of the vinyl monomer used in the first step may be used as the SP value of the vinyl monomer (a).

[0047] (Living radical polymerization) As the living radical polymerization carried out in the first step, known polymerization methods can be adopted. Specific examples of the living radical polymerization to be used include a method using a compound capable of generating a nitroxide radical (nitroxide method; NMP method); a method of polymerizing a halogenated compound as a polymerization initiation compound in a living manner from the polymerization initiation compound using a metal complex such as copper or ruthenium (ATRP method); a method using a dithiocarboxylic acid ester or a xanthate compound (RAFT method); a method using an organic tellurium compound (TERP method); a method using an organic iodine compound (ITP method); a method using an iodine compound as a polymerization initiation compound and an organic compound such as a phosphorus compound, a nitrogen compound, an oxygen compound, or a hydrocarbon as a catalyst (reversible transfer catalytic polymerization; RTCP method, reversible catalytic mediated polymerization; RCMP method), etc. Among these methods, from the viewpoints of the variety of vinyl monomers that can be used, molecular weight control in the polymer region, uniform composition, or coloring, it is preferable to use the TERP method.

[0048] The TERP method is a method of polymerizing a radical polymerizable compound (vinyl monomer) using an organic tellurium compound as a chain transfer agent, and is, for example, the method described in International Publication No. 2004 / 14848, International Publication No. 2004 / 14962, International Publication No. 2004 / 072126, and International Publication No. 2004 / 096870.

[0049] Specific polymerization methods of the TERP method include the following (a-1) to (a-4).

[0050] (a-1) A method of polymerizing a vinyl monomer (a) using an organic tellurium compound represented by the following general formula (1).

[0051] (a-2) A method of polymerizing a vinyl monomer (a) using a mixture of an organic tellurium compound represented by the following general formula (1) and an azo-based polymerization initiator.

[0052] (a-3) A method of polymerizing a vinyl monomer (a) using a mixture of an organic tellurium compound represented by the following general formula (1) and an organic ditelluride compound represented by formula (3).

[0053] (a-4) A method of polymerizing vinyl monomer (a) using a mixture of an organic tellurium compound represented by the following general formula (1), an azo polymerization initiator, and an organic ditelluride compound represented by the following general formula (3).

[0054] R 11 -Te-C-R 12 R 13 R 14 …(1) 〔In general formula (1), R 11 is an alkyl group, aryl group, or aromatic heterocyclic group having 1 to 8 carbon atoms. R 12 and R 13 are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. R 14 is an alkyl group, aryl group, substituted aryl group, aromatic heterocyclic group, alkoxy group, acyl group, amide group, oxycarbonyl group, cyano group, allyl group, or propargyl group having 1 to 8 carbon atoms.〕

[0055] R 11 -Te-Te-R 11 …(3) 〔In general formula (3), R 11 is an alkyl group, aryl group, or aromatic heterocyclic group having 1 to 8 carbon atoms.〕

[0056] As described above, the group represented by R 11 is an alkyl group, aryl group, or aromatic heterocyclic group having 1 to 8 carbon atoms, and specifically, it is as follows.

[0057] Examples of the alkyl group having 1 to 8 carbon atoms include linear or branched alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, and cyclic alkyl groups such as cyclohexyl group. The alkyl group having 1 to 8 carbon atoms is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and more preferably a linear alkyl group having 1 to 4 carbon atoms.

[0058] Examples of the aryl group include a phenyl group, a naphthyl group, etc.

[0059] Examples of the aromatic heterocyclic group include a pyridyl group, a furyl group, a thienyl group, etc.

[0060] R 12 and R 13 The groups represented by are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and each group is specifically as follows.

[0061] Examples of the alkyl group having 1 to 8 carbon atoms include linear or branched alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and cyclic alkyl groups such as a cyclohexyl group. The alkyl group having 1 to 8 carbon atoms is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group.

[0062] R 14 The group represented by is an alkyl group having 1 to 8 carbon atoms, an aryl group, a substituted aryl group, an aromatic heterocyclic group, an alkoxy group, an acyl group, an amide group, an oxycarbonyl group, a cyano group, an allyl group or a propargyl group, and is specifically as follows.

[0063] Examples of the alkyl group having 1 to 8 carbon atoms include linear or branched alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and cyclic alkyl groups such as a cyclohexyl group. The alkyl group having 1 to 8 carbon atoms is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group.

[0064] Examples of the aryl group include a phenyl group, a naphthyl group, etc. A phenyl group is preferred.

[0065] Examples of the substituted aryl group include a phenyl group having a substituent, a naphthyl group having a substituent, etc. Examples of the substituent of the substituted aryl group include a halogen atom, a hydroxy group, an alkoxy group, an amino group, a nitro group, a cyano group, -COR 141 a carbonyl-containing group represented by (R 141 is an alkyl group having 1 to 8 carbon atoms, an aryl group, an alkoxy group having 1 to 8 carbon atoms or an aryloxy group), a sulfonyl group, a trifluoromethyl group, etc. In the substituted aryl group, it is preferably substituted by one or two of these substituents.

[0066] Examples of the aromatic heterocyclic group include a pyridyl group, a furyl group, a thienyl group, etc.

[0067] The alkoxy group is preferably a group in which an alkyl group having 1 to 8 carbon atoms is bonded to an oxygen atom. Examples thereof include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, etc.

[0068] Examples of the acyl group include an acetyl group, a propionyl group, a benzoyl group, etc.

[0069] Examples of the amide group include -CONR 1421 R 1422 (R 1421 , R 1422 are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an aryl group).

[0070] Examples of the oxycarbonyl group include -COOR 1431 (R 1431is preferably a group represented by a hydrogen atom, an alkyl group or an aryl group having 1 to 8 carbon atoms. Examples thereof include a carboxy group, a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, an n-butoxycarbonyl group, a sec-butoxycarbonyl group, a tert-butoxycarbonyl group, an n-pentyloxycarbonyl group, a phenoxycarbonyl group and the like. The oxycarbonyl group preferably includes a methoxycarbonyl group and an ethoxycarbonyl group.

[0071] Examples of the allyl group include, for example, -CR 1441 R 1442 -CR 1443 =CR 1444 R 1445 (R 1441 、R 1442 are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and R 1443 、R 1444 、R 1445 are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an aryl group, and the respective substituents may be connected in a cyclic structure) and the like.

[0072] Examples of the propargyl group include, for example, -CR 1451 R 1452 -C≡CR 1453 (R 1451 、R 1452 is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and R 1453 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group or a silyl group) and the like.

[0073] Specific examples of the organic tellurium compound represented by the general formula (1) include ethyl = 2-methyl-2-n-butyltellanyl-propionate, ethyl = 2-n-butyltellanyl-propionate, (2-hydroxyethyl) = 2-methyl-methyltellanyl-propionate and the like described in International Publication No. 2004 / 14848, International Publication No. 2004 / 14962, International Publication No. 2004 / 072126, and International Publication No. 2004 / 096870.

[0074] Specific examples of the organic ditelluride compound represented by the general formula (3) include dimethylditelluride, dibutylditelluride, and the like.

[0075] The azo-based polymerization initiator can be used without particular limitation as long as it is an azo-based polymerization initiator used in ordinary radical polymerization. For example, 2,2'-azobis(isobutyronitrile) (AIBN), 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), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) (V-70), 2,2'-azobis(N-butyl-2-methylpropionamide) (VAm-110), and the like can be mentioned.

[0076] In the polymerization step, in a container substituted with an inert gas, the vinyl monomer (a), the organic tellurium compound of the general formula (1), and, depending on the type of the vinyl monomer (a), for the purposes of promoting the reaction, controlling the molecular weight and molecular weight distribution, etc., an azo-based polymerization initiator and / or an organic ditelluride compound of the general formula (3) are further mixed. At this time, examples of the inert gas include nitrogen, argon, helium, and the like. The inert gas is preferably argon or nitrogen.

[0077] The amount of the vinyl monomer (a) used in the polymerization methods of the above (a-1), (a-2), (a-3), and (a-4) may be appropriately adjusted according to the physical properties of the target block copolymer. It is preferable that the amount of the vinyl monomer (a) used is 5 mol to 10,000 mol per 1 mol of the organic tellurium compound of the general formula (1).

[0078] In the polymerization method of the above (a-2), when the organic tellurium compound of the general formula (1) and the azo-based polymerization initiator are used in combination, it is preferable that the amount of the azo-based polymerization initiator used is 0.01 mol to 10 mol per 1 mol of the organic tellurium compound of the general formula (1).

[0079] In the above polymerization method (a-3), when the organotellurium compound of general formula (1) and the organoditelluride compound of general formula (3) are used in combination, it is preferable to use 0.01 mol to 100 mol of the organoditelluride compound of general formula (3) per 1 mol of the organotellurium compound of general formula (1).

[0080] In the above polymerization method (a-4), when an organic tellurium compound of general formula (1), an organic ditelluride compound of general formula (3), and an azo polymerization initiator are used in combination, the amount of the organic ditelluride compound of general formula (3) used per 1 mol of the organic tellurium compound of general formula (1) is preferably 0.01 mol to 100 mol, and the amount of the azo polymerization initiator used per 1 mol of the organic tellurium compound of general formula (1) is preferably 0.01 mol to 10 mol.

[0081] The polymerization step can be carried out without a solvent, but can also be carried out by mixing and stirring the above compounds in a polymerization solvent generally used in living radical polymerization.

[0082] When a polymerization solvent is used, it is preferable that the solvent is capable of dissolving the vinyl monomer (a), and an example of the solvent is the solvent (Y) described below.

[0083] The amount of the solvent used in the first step is preferably 0.01 ml or more, more preferably 0.05 ml or more, even more preferably 0.1 ml or more, and is preferably 50 ml or less, more preferably 10 ml or less, even more preferably 1 ml or less, per gram of the vinyl monomer (a).

[0084] The reaction temperature and reaction time of the polymerization reaction may be appropriately adjusted depending on the molecular weight or molecular weight distribution of the resulting polymer component, but the reaction is usually performed at 0° C. to 150° C. for 1 minute to 100 hours with stirring. The pressure during the polymerization reaction is usually normal pressure, but it may be increased or decreased.

[0085] The growing end of the polymer obtained by the polymerization reaction is -TeR derived from tellurium compounds.11 (wherein R 11 is the same as R in formula (1) 11 ), and thus can be used as a chain transfer agent for living radicals.

[0086] The polymer (macro chain transfer agent (X)) obtained in the first step may be directly used in the subsequent second-step polymerization without deactivating the functional group having living radical polymerization ability, or may be recovered by ordinary separation and purification means such as the reprecipitation method and then used in the subsequent second step.

[0087] <Second Step> In the second step, the macro chain transfer agent (X) obtained in the first step is mixed with a vinyl monomer (b) and a solvent (Y), and living radical polymerization is carried out to produce a block copolymer.

[0088] (Vinyl monomer (b)) The vinyl monomer (b) is a vinyl monomer having a larger SP value than the vinyl monomer (a). The difference (SP3 - SP1) between the SP value (SP3) of the vinyl monomer (b) and the SP value (SP1) of the solvent (Y) is 2 or more. SP3 - SP1 is preferably 2 to 6, more preferably 3 to 5. If SP3 - SP1 is within the above range, the block copolymer generated by polymerization can be self-organized in situ. So-called polymerization-induced self-assembly (PISA) becomes possible.

[0089] In addition, the difference (SP3 - SP2) between the SP value (SP3) of the vinyl monomer (b) and the SP value (SP2) of the vinyl monomer (a) is preferably 1 to 5, more preferably 2 to 4. If SP3 - SP2 is within the above range, emulsion polymerization with a narrower molecular weight distribution and more uniform particle size becomes possible.

[0090] Examples of the vinyl monomer (b) include vinyl monomers having an acidic group, vinyl monomers having a nitrogen-containing functional group, (meth)acrylates having a hydroxy group, (meth)acrylamides, etc., and one or more of these can be used in combination.

[0091] Examples of the acidic group include a carboxy group (-COOH), a sulfonic acid group (-SO3H), a phosphoric acid group (-OPO3H2), a phosphonic acid group (-PO3H2), a phosphinic acid group (-PO2H2), and the like.

[0092] Examples of the vinyl monomer having the acidic group include a vinyl monomer having a carboxy group, a vinyl monomer having a sulfonic acid group, a vinyl monomer having a phosphoric acid group, and the like. Specific examples of the vinyl monomer having the acidic group include (meth)acrylic acid, (meth)acrylate having an acidic group, and the like. Examples of the (meth)acrylate having an acidic group include monomers obtained by reacting hydroxyalkyl (meth)acrylate with acid anhydrides such as maleic anhydride, succinic anhydride, and phthalic anhydride (for example, 2-acryloyloxyethyl hydrogen succinate, 2-methacryloyloxyethyl hydrogen succinate, 2-(acryloyloxy)ethyl hydrogen hexahydrophthalate, 2-(methacryloyloxyethyl) hydrogen hexahydrophthalate, 1-(2-acryloyloxyethyl) phthalate, 1-(2-methacryloyloxyethyl) phthalate), etc., (meth)acrylate having a carboxy group; (meth)acrylate having a sulfonic acid group such as ethyl sulfonate (meth)acrylate; (meth)acrylate having a phosphoric acid group such as 2-(phosphonooxy)ethyl (meth)acrylate, and the like.

[0093] Among them, the vinyl monomer having the acidic group is preferably (meth)acrylic acid and / or (meth)acrylate having a carboxy group, and more preferably (meth)acrylic acid.

[0094] Examples of the nitrogen-containing functional group include an amino group, an aromatic heterocyclic group, a non-aromatic heterocyclic group, and the like. In the present specification, the amino group means, in addition to a general amino group (-NH2), a substituted amino group represented by -NHR a ,-NR a R b where H is substituted by a hydrocarbon group, -NRa , R b each independently represents a chain or cyclic hydrocarbon group. Also, R a and R b may be bonded to each other to form a cyclic structure. ) etc. are included.

[0095] Specific examples of the vinyl monomer having the amino group include dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, dimethylaminobutyl (meth)acrylate, diethylaminoethyl (meth)acrylate, diethylaminopropyl (meth)acrylate, diethylaminobutyl (meth)acrylate, ethylaminoethyl (meth)acrylate, ethylaminopropyl (meth)acrylate, ethylaminobutyl (meth)acrylate, propylaminoethyl (meth)acrylate, propylaminopropyl (meth)acrylate, propylaminobutyl (meth)acrylate, and the like.

[0096] Specific examples of the vinyl monomer having the aromatic heterocyclic group include 1-vinylimidazole, 2-vinylpyridine, 4-vinylpyridine, and the like.

[0097] Specific examples of the vinyl monomer having the non-aromatic heterocyclic group include vinyl monomers having a morpholino group such as 4-(meth)acryloylmorpholine, morpholin-4-yl (meth)acrylate, N-((meth)acrylamidomethyl)morpholine, 2-(4-morpholinyl)ethyl (meth)acrylate; vinyl monomers having a lactam group such as vinylpyrrolidone, N-vinyl-5-methylpyrrolidone, N-vinyl-5-ethylpyrrolidone, N-vinyl-5-propylpyrrolidone, N-vinyl-5-butylpyrrolidone, 1-(2-propenyl)-2-pyrrolidone, N-vinylpiperidone, N-vinylcaprolactam; vinylpyrrole, and the like.

[0098] Specific examples of the (meth)acrylate having a hydroxy group include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate; hydroxypolyalkylene glycol (meth)acrylates such as hydroxypolyethylene glycol (meth)acrylate, hydroxypolypropylene glycol (meth)acrylate; (meth)acrylates having a lactone-modified hydroxy group, and the like.

[0099] Specific examples of the (meth)acrylamides include N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N,N-diisopropyl (meth)acrylamide, (meth)acrylamide, N-methyl (meth)acrylamide, N-ethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-tert-butyl (meth)acrylamide, N-octyl (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, N-propoxymethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide, diacetoneacrylamide and the like.

[0100] The SP value (solubility parameter) of the vinyl monomer (b) can be calculated by the same method as the method for calculating the SP value of the vinyl monomer (a).

[0101] (Solvent (Y)) The solvent (Y) is a solvent capable of dissolving the macro chain transfer agent (X), and a solvent having a difference in SP value (solubility parameter) from the vinyl monomer (a) or the vinyl monomer (b) within the above range can be used. The SP value (solubility parameter) of the solvent (Y) is the Hildebrand solubility parameter (25 ° C, unit (cal / cm 3) 1 / 2 ) is as follows.

[0102] The solvent (Y) is preferably a hydrophobic organic solvent, more preferably having an SP value of less than 10.0, and even more preferably having an SP value of 7.0 to 9.5.

[0103] Examples of the hydrophobic organic solvent include aliphatic hydrocarbons such as pentane (SP value: 7.0), hexane (SP value: 7.3), heptane (SP value: 7.4), octane (SP value: 7.6), nonane, and decane; alicyclic hydrocarbons such as cyclohexane (SP value: 8.2); aromatic hydrocarbons such as benzene (SP value: 9.2) and toluene (SP value: 8.9). Among them, aliphatic hydrocarbons are preferred. Also, a mixed solvent of these may be used. The SP value of the mixed solvent can be calculated as the sum of the products of the SP value and volume fraction of each solvent.

[0104] If the difference in the SP value (solubility parameter) from the vinyl monomer (a) or vinyl monomer (b) is adjusted to be within the above range, a mixed solvent obtained by mixing a hydrophilic organic solvent with a hydrophobic organic solvent may be used as the solvent (Y).

[0105] Examples of the hydrophilic organic solvent include primary alcohols such as methanol (SP value: 14.5), ethanol (SP value: 12.7), n-butanol (SP value: 11.4), and n-hexanol (SP value: 10.7); secondary alcohols such as isopropanol (SP value: 11.5); tertiary alcohols such as t-butanol (SP value: 10.6); ethylene glycol (SP value: 14.6), tetrahydrofuran (SP value: 9.1), methyl ethyl ketone (SP value: 9.3), acetone (SP value: 10.0), 1-methoxy-2-propanol (SP value: 11.3), acetonitrile (SP value: 11.9), etc. A mixed solvent of these may also be used. The SP value of the mixed solvent can be calculated as the sum of the products of the SP value and volume fraction of each solvent.

[0106] (Polymerization method) The polymerization in the second step is carried out by living radical polymerization by mixing a macro chain transfer agent (X), a vinyl monomer (b), and a solvent (Y) and stirring them.

[0107] In the macro chain transfer agent (X), the functional group having the ability of living radical polymerization present at the growing end of the polymer is -TeR 11 (In the formula, R 11 is the same as R in the above formula (1) 11 ), the specific polymerization methods of the living radical polymerization in the second step include the following (b-1) to (b-4).

[0108] (b-1) A method of polymerizing the vinyl monomer (b) using the macro chain transfer agent (X).

[0109] (b-2) A method of polymerizing the vinyl monomer (b) using a mixture of the macro chain transfer agent (X) and an azo-based polymerization initiator.

[0110] (b-3) A method of polymerizing the vinyl monomer (b) using a mixture of the macro chain transfer agent (X) and the organic ditelluride compound represented by the above formula (3).

[0111] (b-4) A method of polymerizing the vinyl monomer (b) using a mixture of the macro chain transfer agent (X), an azo-based polymerization initiator, and the organic ditelluride compound represented by the above formula (3).

[0112] As the organic ditelluride compound represented by the above formula (3) and the azo-based polymerization initiator, those exemplified in the first step can be used.

[0113] In the polymerization step, in a container substituted with an inert gas, the vinyl monomer (b), the macro chain transfer agent (X), and, for the purpose of promoting the reaction, controlling the molecular weight and molecular weight distribution, etc., according to the type of the vinyl monomer (b), an azo-based polymerization initiator and / or an organic ditelluride compound of the general formula (3) are further mixed. At this time, examples of the inert gas include nitrogen, argon, helium, etc. Preferably, argon and nitrogen are good.

[0114] In the polymerization methods of the above (b-1), (b-2), (b-3) and (b-4), the amount of the vinyl monomer (b) used (the amount of the vinyl monomer (b) present in the reaction system in the second step) may be appropriately adjusted according to the physical properties of the target block copolymer.

[0115] The amount of the vinyl monomer (b) used is preferably 50 mol or more, more preferably 100 mol or more, still more preferably 300 mol or more, and preferably 1000 mol or less, more preferably 800 mol or less, still more preferably 500 mol or less, per 1 mol of the macro chain transfer agent (X). By setting the amount of the vinyl monomer (b) used within the above range, the vinyl monomer (b) self-assembles in the solvent (Y), facilitating the formation of self-stabilized particles.

[0116] In the polymerization method of the above (b-2), when the macro chain transfer agent (X) and an azo polymerization initiator are used in combination, the amount of the azo polymerization initiator used is preferably 0.01 mol to 10 mol per 1 mol of the macro chain transfer agent (X).

[0117] In the polymerization method of the above (b-3), when the macro chain transfer agent (X) and the organic ditelluride compound of the general formula (3) are used in combination, the amount of the organic ditelluride compound of the general formula (3) used is preferably 0.01 mol to 100 mol per 1 mol of the macro chain transfer agent (X).

[0118] In the polymerization method of the above (b-4), when the macro chain transfer agent (X), the organic ditelluride compound of the general formula (3) and an azo polymerization initiator are used in combination, the amount of the organic ditelluride compound of the general formula (3) used is preferably 0.01 mol to 100 mol per 1 mol of the macro chain transfer agent (X), and the amount of the azo polymerization initiator used is preferably 0.01 mol to 10 mol per 1 mol of the macro chain transfer agent (X).

[0119] The amount of the solvent (Y) used in the second step is preferably 1 ml or more, more preferably 3 ml or more, still more preferably 5 ml or more, and preferably 30 ml or less, more preferably 20 ml or less, still more preferably 10 ml or less, per 1 g of the vinyl monomer (b). By setting the amount of the vinyl monomer (b) within the above range, more precise polymerization of the vinyl monomer (b) becomes possible.

[0120] The reaction temperature and reaction time may be appropriately adjusted according to the molecular weight or molecular weight distribution of the resulting polymer component, but usually, stirring is carried out at 0 °C to 150 °C for 1 minute to 100 hours. At this time, the pressure is usually carried out at normal pressure, but it may be pressurized or depressurized.

[0121] By the polymerization in the second step, a dispersion in which amphiphilic block copolymer fine particles with controlled particle diameters are dispersed in a hydrophobic solvent is obtained. The method for separating the block copolymer fine particles from the dispersion is not particularly limited, and known methods can be adopted. For example, the desired block copolymer can be purified by distilling off volatile components (such as liquid media), reprecipitation treatment, vacuum drying, heat drying, filtration, centrifugation, decantation, etc.

[0122] The growth end of the block copolymer obtained in the second step (the end of the B block) is —TeR derived from a tellurium compound 11 (wherein R 11 is the same as R in formula (1) 11 ) and deactivates by the operation in air after the polymerization reaction ends, but tellurium atoms may remain. Since the copolymer with tellurium atoms remaining at the end may be colored or have poor thermal stability, it is preferable to remove the tellurium atoms.

[0123] As methods for removing tellurium atoms, there are radical reduction methods using tributylstannane or thiol compounds, etc.; methods of adsorbing with activated carbon, silica gel, activated alumina, activated clay, molecular sieves, and polymer adsorbents, etc.; methods of adsorbing metals with ion exchange resins, etc.; peroxide addition methods such as adding hydrogen peroxide solution or benzoyl peroxide, etc., or blowing air or oxygen into the system to oxidatively decompose tellurium atoms at the copolymer terminals, and liquid-liquid extraction methods or solid-liquid extraction methods for removing residual tellurium compounds by combining water washing and appropriate solvents; purification methods in a solution state such as ultrafiltration for extracting and removing only those with a specific molecular weight or less can be used, and these methods can also be used in combination. Incidentally, the other end of the copolymer obtained in the second step (the end opposite to the growth end, the end of the A block) is -CR 12 R 13 R 14 (wherein R 12 、R 13 and R 14 are the same as R 12 R 13 R 14 in formula (1)).

[0124] Also, in this production method, a radical reducing agent (for example, tributylstannane, thiol compound, etc.) is dissolved in the solvent (Y) of the dispersion of block copolymer fine particles obtained by the polymerization in the second step, and then the solvent (Y) is separated, so that the block copolymer fine particles can be separated from the dispersion, and the residual tellurium compound can be removed and recovered.

[0125] <Block copolymer> The block copolymer obtained by this production method is a block copolymer having an A block and a B block, and from the viewpoint of the polymerization operation, it is preferably an A-B type diblock copolymer. However, the block copolymer obtained by this production method may be a triblock copolymer and is not particularly limited.

[0126] The molecular weight of the block copolymer is measured by the GPC method. The weight average molecular weight (Mw) of the block copolymer is preferably 20,000 or more, more preferably 30,000 or more, still more preferably 50,000 or more, and preferably 200,000 or less, more preferably 180,000 or less, still more preferably 150,000 or less.

[0127] The molecular weight distribution (Mw / Mn) of the block copolymer is preferably 2.5 or less, more preferably 2.0 or less, still more preferably 1.8 or less. In the present invention, the molecular weight distribution (Mw / Mn) of the block copolymer is determined by (weight average molecular weight (Mw) of the block copolymer) / (number average molecular weight (Mn) of the block copolymer). The smaller the Mw / Mn, the narrower the molecular weight distribution width, and the more uniform the molecular weight of the copolymer. When the value is 1.0, the molecular weight distribution width is the narrowest. That is, the lower limit value of Mw / Mn is 1.0. When the molecular weight distribution (Mw / Mn) of the block copolymer exceeds 2.5, it will contain those with a small molecular weight or a large molecular weight.

[0128] The content of block A is preferably 1% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more, and preferably 65% by mass or less, more preferably 55% by mass or less, still more preferably 50% by mass or less in 100% by mass of the whole block copolymer.

[0129] The content of block B is preferably 35% by mass or more, more preferably 45% by mass or more, still more preferably 50% by mass or more, and preferably 99% by mass or less, more preferably 85% by mass or less, still more preferably 80% by mass or less in 100% by mass of the whole block copolymer.

[0130] According to this production method, it is suitable in that an amphiphilic block copolymer having a high molecular weight and a controlled molecular weight distribution can be obtained. The block copolymer obtained by this production method can be used in a wide range of applications. Specifically, for example, it can be applied to various applications such as dispersants, binders, adhesives, paints, surfactants, and the like.

Examples

[0131] Hereinafter, the present invention will be described in more detail based on specific examples. The present invention is not limited to the following examples, and can be appropriately modified and implemented within the scope of not changing the gist thereof. The meanings of the abbreviations are as follows. In addition, the polymerization rate, weight average molecular weight (Mw), molecular weight distribution (Mw / Mn), particle diameter and particle size distribution of the block copolymer of the macro chain transfer agent were evaluated according to the following methods.

[0132] BTEE: Ethyl = 2-methyl-2-n-butyltellanyl-propionate AIBN: 2,2’-azobis(isobutyronitrile) EHA: Ethylhexyl acrylate AA: Acrylic acid ACMO: Acryloyl morpholine 4-HBA: 4-hydroxybutyl acrylate DMAAm: Dimethylacrylamide Hep: Heptane n-Oct: Normal octane MP: Methoxypropanol

[0133] (Polymerization rate) 1H-NMR was measured using a nuclear magnetic resonance (NMR) spectrometer (manufactured by Bruker, model: AVANCE500 (frequency 500 MHz)) (solvent: deuterated chloroform, internal standard: tetramethylsilane). For the obtained NMR spectrum, the integration ratio of the peaks of the vinyl group derived from the monomer and the ester side chain of the polymer was determined, and the polymerization rate of the monomer was calculated.

[0134] (Weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn)) It was determined by gel permeation chromatography (GPC) using a high-performance liquid chromatograph (manufactured by Tosoh Corporation, model: HLC-8320). One column of SHODEX GPC KF-603 (φ6.0 mm × 150 mm) (manufactured by Showa Denko KK) was used, a 30 mmol / L lithium bromide - 30 mmol / L acetic acid - N-methylpyrrolidone solution was used as the mobile phase, and a differential refractometer was used as the detector. The measurement conditions were a column temperature of 40 °C, a sample concentration of 10 mg / mL, a sample injection volume of 10 μL, and a flow rate of 0.2 mL / min. A calibration curve was created using polystyrene (molecular weights 70,500, 37,900, 19,920, 10,200, 4,290, 2,630, 1,150) as the standard substance, and the weight-average molecular weight (Mw) and number-average molecular weight (Mn) were measured. The molecular weight distribution (Mw / Mn) was calculated from these measured values.

[0135] (Particle size measurement) The particle size was measured by the dynamic light scattering method (manufactured by Otsuka Electronics Co., Ltd., model: ELSZ-2000ZS). The average particle diameter d (hydrodynamic diameter) was determined by the cumulant method from the autocorrelation function obtained by the photon correlation method, and the particle size distribution was determined by the histogram method.

[0136] (Synthesis of macro chain transfer agent) (Macro chain transfer agent No. 1) Into a 50 mL reactor purged with argon, 10.0 g of EHA, 0.162 g of BTEE, and 18 mg of AIBN, which had been previously purged with argon, were charged and reacted at 60 °C for 12 hours. Then, reprecipitation purification was performed with methanol to obtain macro chain transfer agent No. 1. The polymerization rate was 90%, Mw was 20473, and Mw / Mn was 1.29.

[0137] (Macro chain transfer agent No. 2) In a 50 mL reactor replaced with argon, 7.3 g of EHA, 2.7 g of AA, 0.195 g of BTEE, and 40 mg of AIBN, which had been previously replaced with argon, were charged and reacted at 60 °C for 24 hours. Thereafter, purification by reprecipitation with methanol was performed to obtain Macro Chain Transfer Agent No. 2. The polymerization rate was 95%, Mw was 20034, and Mw / Mn was 1.31.

[0138] Details are shown in Table 1 below.

[0139]

Table 1

[0140] <Examples 1 to 5, Comparative Examples 1 to 3> (Example 1) Macro Chain Transfer Agent No. 1, ACMO, AIBN, and Hep, which had been previously replaced with argon, were added to a 50 mL reactor replaced with argon so as to have the compounding ratios shown in Table 2, and stirred for 30 minutes, followed by reacting at 60 °C for 8 hours to obtain a dispersion of the block copolymer. When the stirring state of the reaction solution was confirmed, it was confirmed that the entire reaction solution was stirred from the start to the end of the polymerization reaction, and a dispersion of the block copolymer could be stably produced. The polymerization rate was 98%.

[0141] The Mw of the obtained block copolymer was 126560, Mw / Mn was 1.58, the average particle diameter was 254.9 nm, and the particle size distribution (particle diameter distribution) was 0.186.

[0142] (Examples 2 to 5) A dispersion of the block copolymer was prepared in the same manner as the production method of Example 1, except that the macro chain transfer agent, vinyl monomer, azo polymerization initiator, solvent, their amounts, and the polymerization conditions were changed as shown in Table 2 below.

[0143] (Comparative Example 1) In a 50 mL reactor substituted with argon, ACMO, AIBN, and Hep that had been previously substituted with argon were added so as to achieve the compounding ratio shown in Table 2, and the mixture was stirred for 30 minutes and then reacted at 60 °C for 48 hours. The polymerization rate was 2.1%. Also, the Mw, molecular weight distribution Mw / Mn, average particle diameter, and particle size distribution of the block copolymer could not be measured.

[0144] (Comparative Example 2) In a 50 mL reactor substituted with argon, a macro chain transfer agent No. 1, DMAAm, AIBN, and MP that had been previously substituted with argon were added so as to achieve the compounding ratio shown in Table 2, and the mixture was stirred for 30 minutes and then reacted at 60 °C for 24 hours to obtain a block copolymer. The polymerization rate was 78%. When the stirring state of the reaction solution was checked, it was confirmed that the viscosity of the reaction solution had increased from the middle of the polymerization reaction.

[0145] The Mw of the obtained block copolymer was 25,000, and Mw / Mn was 2.35. Since the block copolymer had solidified, the average particle diameter and particle size distribution could not be measured.

[0146] (Comparative Example 3) In a 50 mL reactor substituted with argon, a macro chain transfer agent No. 2, AA, AIBN, and Hep that had been previously substituted with argon were added and stirred for 30 minutes, but the macro chain transfer agent No. 2 did not dissolve in Hep.

[0147] Details are shown in Table 2 below.

[0148]

Table 2

[0149] As described above, it was confirmed that in the methods for producing block copolymers of Examples 1 to 5, operations such as extraction of the reaction product from the reaction system after the reaction were easy, and block copolymers with high molecular weight and controlled molecular weight distribution could be obtained.

Claims

1. A method for producing a block copolymer, comprising an A block having a structural unit derived from a vinyl monomer (a) and a B block having a structural unit derived from a vinyl monomer (b), the method including a first step of subjecting the vinyl monomer (a) to living radical polymerization to prepare a macro chain transfer agent (X), and a second step of mixing the macro chain transfer agent (X), the vinyl monomer (b) and a solvent (Y) and subjecting them to living radical polymerization, wherein the difference (SP2 - SP1) between the SP value (SP2) of the vinyl monomer (a) and the SP value (SP1) of the solvent (Y) is from -1.5 to 1.5, and the difference (SP3 - SP1) between the SP value (SP3) of the vinyl monomer (b) and the SP value (SP1) of the solvent (Y) is 2 or more. A method for producing a block copolymer, characterized by the above.

2. The method for producing a block copolymer according to claim 1, wherein the amount of the vinyl monomer (b) present in the reaction system in the second step is 50 mol or more and 1000 mol or less per 1 mol of the macro chain transfer agent (X).

3. The method for producing a block copolymer according to claim 1 or claim 2, wherein the weight average molecular weight of the macro chain transfer agent (X) is 1000 or more and 50000 or less.

4. The method for producing a block copolymer according to claim 1 or claim 2, wherein the SP value (SP2) of the vinyl monomer (a) is smaller than the SP value (SP3) of the vinyl monomer (b).

5. The method for producing a block copolymer according to claim 1 or claim 2, wherein the vinyl monomer (a) is at least one vinyl monomer selected from the group consisting of (meth)acrylates having an alkyl group, (meth)acrylates having an aryl group, and styrene-based monomers.

6. The method for producing a block copolymer according to claim 1 or claim 2, wherein the vinyl monomer (b) is at least one vinyl monomer selected from the group consisting of vinyl monomers having an acidic group, vinyl monomers having a nitrogen-containing functional group, (meth)acrylates having a hydroxy group, and (meth)acrylamides.

7. The method for producing a block copolymer according to claim 1 or claim 2, wherein the solvent (Y) is a hydrophobic organic solvent.

8. The method for producing a block copolymer according to claim 1 or claim 2, wherein the SP value (SP1) of the solvent (Y) is less than 10.

0.

9. The method for producing a block copolymer according to claim 1 or 2, wherein the block copolymer is an A-B type diblock copolymer.

10. The method for producing a block copolymer according to claim 1 or 2, wherein the living radical polymerization in the first step is a living radical polymerization using an organic tellurium compound represented by the following general formula (1). R １１ -Te-C-R １２ R １３ R １４ ... Formula (1) 〔In general formula (1), R １１ is an alkyl group, aryl group, or aromatic heterocyclic group having 1 to 8 carbon atoms. R １２ and R １３ are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. R １４ is an alkyl group, aryl group, substituted aryl group, aromatic heterocyclic group, alkoxy group, acyl group, amide group, oxycarbonyl group, cyano group, allyl group, or propargyl group.〕

11. A dispersion of amphiphilic block copolymer fine particles obtained by the method for producing a block copolymer according to claim 1 or 2.

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