Method for producing aqueous solution of amphiphilic polymer

Abstract

To provide a method for producing an aqueous solution of an amphiphilic polymer which achieves improvement of solvent removal efficiency while preventing foaming during solvent removal from an aqueous solution, which contains the amphiphilic polymer and a hydrophilic organic solvent.SOLUTION: A method for producing an aqueous solution of an amphiphilic polymer includes a removal step for removing a hydrophilic organic solvent by distillation from a mixed solution, which contains the hydrophilic organic solvent as well as an amphiphilic polymer and water. The hydrophilic organic solvent has a boiling point of less than 100°C. The heating temperature (T1) of the mixed solution in the removal step is less than 100°C. The removal step performs distillation while feeding a gaseous fluid into the vapor phase section of the system.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for producing an amphiphilic polymer aqueous solution.

Background Art

[0002] Amphiphilic polymers are useful materials widely used in inks, paints, coating agents, adhesives, cosmetics, polishing compositions, etc. In adapting amphiphilic polymers to various applications, it is required to use them in the form of an aqueous solution with a sufficiently reduced content of organic solvents in consideration of the environment. For example, Patent Document 1 discloses using a neutralized product (amphiphilic polymer) of a copolymer obtained by polymerizing a vinyl monomer having an acidic group and a vinyl monomer having no acidic group as a dispersant for aqueous ink. Patent Document 2 discloses using a copolymer (amphiphilic polymer) obtained by polymerizing a (meth)acrylic monomer having an alkoxypolyalkylene glycol group as a dispersant for aqueous ink.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the polymerization reaction of amphiphilic polymers, after polymerization in a hydrophilic organic solvent, substitution with an aqueous solvent (distillation of the organic solvent) is required. However, since amphiphilic polymers have a surfactant action, they tend to foam when containing an aqueous solvent, and it is difficult to achieve sufficient distillation of the solvent due to a decrease in evaporation ability. On the other hand, there is a method of precipitating and filtering the polymer from the polymerization solution and redissolving it in water, but this method has a large load on the manufacturing process.

[0005] The present invention has been made in view of the above circumstances, and aims to provide a method for producing an amphiphilic polymer aqueous solution that improves the solvent distillation efficiency while suppressing foaming when distilling off the solvent from an aqueous solution containing an amphiphilic polymer and a hydrophilic organic solvent.

Means for Solving the Problems

[0006] The method for producing an amphiphilic polymer aqueous solution of the present invention, which has solved the above problems, is a method for producing an amphiphilic polymer aqueous solution comprising a distillation step of distilling off the hydrophilic organic solvent from a mixed solution containing an amphiphilic polymer, a hydrophilic organic solvent, and water by a distillation method, wherein the boiling point of the hydrophilic organic solvent is less than 100°C, the heating temperature (T1) of the aqueous solution in the distillation step is less than 100°C, and in the distillation step, distillation is performed while introducing a gas fluid into the gas phase part of the system.

[0007] The reason why foaming can be suppressed by introducing a gas fluid is not necessarily clear, but it is considered as follows. In the distillation step, as the temperature in the system rises, the saturated vapor pressure of the mixed solution rises. When the saturated vapor pressure becomes equal to the atmospheric pressure, vaporization (internal evaporation) occurs not only on the surface of the mixed solution but also inside, and the generated vapor becomes bubbles. The mixed solution is stirred by these bubbles, causing foaming. However, since the mixed solution contains water and an amphiphilic polymer, the foaming becomes intense due to the surfactant action. However, by introducing a gas fluid into the gas phase part of the system, the discharge of solvent molecules present in the gas phase part of the system to the outside of the system is promoted. When the number of moles of solvent molecules present in the gas phase part of the system decreases, the pressure (partial pressure) of the vapor of the mixed solution decreases. As a result, it is considered that the solvent can be distilled off below the boiling point of water while suppressing internal evaporation (suppressing foaming).

Effects of the Invention

[0008] According to the present invention, it is possible to improve the distillation efficiency of a solvent while suppressing foaming when the solvent is distilled off from an aqueous solution containing an amphiphilic polymer and a hydrophilic organic solvent. Therefore, the productivity of the amphiphilic polymer aqueous solution is increased.

Brief Description of the Drawings

[0009]

Figure 1

Embodiments for Carrying Out the Invention

[0010] (Definition) In the present specification, “(meth)acryl” means “at least one of acrylic and methacrylic”. “(meth)acrylate” means “at least one of acrylate and methacrylate”. “(meth)acrylate” means “an ester compound in which a hydrogen atom of a carboxy group of (meth)acrylic acid is substituted with an organic group”. “(meth)acryloyl” means “at least one of acryloyl and methacryloyl”. “(meth)acrylic monomer” means “a monomer having a (meth)acryloyl group in the molecule” and includes “(meth)acrylate”. “Vinyl monomer” means “a monomer having a carbon-carbon double bond capable of radical polymerization in the molecule” and includes “(meth)acrylate” and “(meth)acrylic monomer”.

[0011] In the present specification, “structural unit derived from (meth)acrylate” means “a structural unit in which a carbon-carbon double bond capable of radical polymerization of (meth)acrylate is polymerized to form a carbon-carbon single bond”. “Structural unit derived from (meth)acrylic monomer” means “a structural unit in which a carbon-carbon double bond capable of radical polymerization of (meth)acrylic monomer is polymerized to form a carbon-carbon single bond”. “Structural unit derived from vinyl monomer” means “a structural unit in which a carbon-carbon double bond capable of radical polymerization of vinyl monomer is polymerized to form a carbon-carbon single bond”.

[0012] In this specification, when it is described as "X to Y" (X and Y are arbitrary numbers), it means "X or more and Y or less". Further, when it is described as "X or more" (X is an arbitrary number), it includes the meaning of "X or more than X", and when it is described as "Y or less" (Y is an arbitrary number), it also includes the meaning of "Y or less than Y". Furthermore, "X and / or Y" (X and Y are arbitrary components) means "at least one of X and Y", and includes three cases: "only X", "only Y", and "X and Y".

[0013] [Method for producing an amphiphilic polymer aqueous solution] The method for producing an amphiphilic polymer aqueous solution of the present invention is a method for producing an amphiphilic polymer aqueous solution comprising a step of distilling off the hydrophilic organic solvent from a mixed solution containing an amphiphilic polymer, a hydrophilic organic solvent, and water by a distillation method, wherein the boiling point of the hydrophilic organic solvent is less than 100°C, the heating temperature (T1) of the mixed solution in the distilling-off step is less than 100°C, and in the distilling-off step, distillation is performed while introducing a gas fluid into the gas phase portion of the system.

[0014] [Preparation of a mixed solution containing an amphiphilic polymer, a hydrophilic organic solvent, and water] First, a mixed solution containing an amphiphilic polymer, a hydrophilic organic solvent, and water (hereinafter, may be simply referred to as "mixed solution") used in the production method of the present invention will be described.

[0015] (Hydrophilic organic solvent) The hydrophilic organic solvent is an organic solvent miscible with water, and is not particularly limited as long as it dissolves the amphiphilic polymer and does not react with the amphiphilic polymer. The hydrophilic organic solvent preferably has a solubility parameter (SP value) of 9.3 or more and 15.0 or less. The solubility parameter is the Hildebrand solubility parameter (25°C, unit (cal / cm 3 ) 1 / 2 ).

[0016] The boiling point (101.33 kPa) of the hydrophilic organic solvent is less than 100 °C, preferably 85 °C or lower, more preferably 70 °C or lower. The lower limit of the boiling point of the hydrophilic organic solvent is not particularly limited, but 50 °C is preferred.

[0017] Examples of the hydrophilic organic solvent include primary alcohols such as methanol (SP value: 14.5) and ethanol (SP value: 12.7); secondary alcohols such as isopropanol (SP value: 11.5); tertiary alcohols such as t-butanol (SP value: 10.6); methyl ethyl ketone (SP value: 9.3), acetone (SP value: 10.0), acetonitrile (SP value: 11.9), etc. Mixed solvents thereof may also be used. When the hydrophilic organic solvent is a mixed solvent, the SP value of the mixed solvent is preferably a liquid composition of 9.3 or more and 15.0 or less, more preferably 10.0 or more, and still more preferably 11.5 or more. The SP value of the mixed solvent can be calculated as the sum of the products of the SP values of the respective solvents and the volume fractions. Further, the mixed solvent may contain a hydrophilic solvent having a boiling point (101.33 kPa) of 100 °C or higher as long as the preferred effects of the present invention are not impaired.

[0018] (Amphiphilic polymer) The amphiphilic polymer is a polymer having both a portion with a large affinity for water (hydrophilic structural unit) and a portion with a smaller affinity for water than the hydrophilic structural unit (hydrophobic structural unit) in the molecular chain, and is at least a polymer soluble in water. Examples of the amphiphilic polymer include polymers containing a hydrophilic structural unit (a) and a hydrophobic structural unit (b).

[0019] (Hydrophilic structural unit) Examples of the hydrophilic structural unit that becomes a portion with a large affinity for water include structural units derived from hydrophilic (meth)acrylic monomers and structural units derived from hydrophilic vinyl monomers other than (meth)acrylic monomers. Examples of the hydrophilic structural unit include a structural unit having a neutralized acidic group, a structural unit having a polyalkylene glycol group, and the like. The hydrophilic structural unit may be used alone or in combination of two or more kinds.

[0020] The structural unit having a neutralized acidic group can be formed by neutralizing the acidic group of a structural unit derived from a vinyl monomer having an acidic group. 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), and a phosphinic acid group (-PO2H2). At least one selected from the group consisting of a carboxy group, a sulfonic acid group, and a phosphoric acid group is preferable as the acidic group. Examples of the basic component for neutralizing the acidic group include hydroxides of alkali metals, hydroxides of alkaline earth metals, aliphatic amine compounds, alcohol amines, ammonia, and the like.

[0021] Examples of the vinyl monomer having an acidic group include (meth)acrylic monomers having an acidic group and vinyl monomers having an acidic group other than (meth)acrylic monomers.

[0022] Examples of the (meth)acrylic monomer having an acidic group include (meth)acrylic acid; (meth)acrylates having a carboxy group such as 2-(meth)acryloyloxyethyl hydrogen succinate, 2-((meth)acryloyloxy)ethyl hydrogen hexahydrophthalate, 2-(meth)acryloyloxyethyl hydrogen phthalate, and a caprolactone adduct of (meth)acrylic acid; (meth)acrylates having a sulfonic acid group such as ethyl (meth)acrylate sulfonate; (meth)acrylates having a phosphoric acid group such as 2-(phosphonooxy)ethyl (meth)acrylate, and the like.

[0023] Examples of the vinyl monomer having an acidic group other than the (meth)acrylic monomer include vinyl monomers having a carboxy group such as crotonic acid, maleic acid, itaconic acid, citraconic acid, and cinnamic acid; vinyl monomers having a sulfonic acid group such as vinylsulfonic acid and 1-propene-2-sulfonic acid; vinyl monomers having a phosphate group such as vinyl phosphate and isopropenyl phosphate; vinyl monomers having a phosphonic acid group such as vinylphosphonic acid and isopropenylphosphonic acid; and vinyl monomers having a phosphinic acid group such as vinylphosphinic acid and (1-methylethenyl)phosphinic acid.

[0024] Examples of the structural unit having a polyalkylene glycol group include a structural unit derived from a (meth)acrylate having a terminal hydroxy group polyalkylene glycol group and a structural unit derived from a (meth)acrylate having an alkoxy polyalkylene glycol group. The polyalkylene glycol group may be, for example, a mixture of ethylene oxide and propylene oxide. Examples of the (meth)acrylate having a terminal hydroxy group polyalkylene glycol group include mono(meth)acrylate of terminal hydroxy group polyethylene glycol (degree of polymerization = 2 to 30) and mono(meth)acrylate of terminal hydroxy group polypropylene glycol (degree of polymerization = 2 to 30). Examples of the (meth)acrylate having an alkoxy polyalkylene glycol group include (meth)acrylates having a polyethylene glycol structural unit such as polyethylene glycol (degree of polymerization = 2 to 30) methyl ether (meth)acrylate, polyethylene glycol (degree of polymerization = 2 to 30) ethyl ether (meth)acrylate, and polyethylene glycol (degree of polymerization = 2 to 30) propyl ether (meth)acrylate; and (meth)acrylates having a polypropylene glycol structural unit such as polypropylene glycol (degree of polymerization = 2 to 30) methyl ether (meth)acrylate, polypropylene glycol (degree of polymerization = 2 to 30) ethyl ether (meth)acrylate, and polypropylene glycol (degree of polymerization = 2 to 30) propyl ether (meth)acrylate.

[0025] (Hydrophobic structural unit) The hydrophobic structural unit, which is a part with low affinity for water, is a structural unit other than the hydrophilic structural unit among the structural units constituting the polymer. Examples of the hydrophobic structural unit include a structural unit derived from a hydrophobic (meth)acrylic monomer and a structural unit derived from a hydrophobic vinyl monomer other than the (meth)acrylic monomer. Examples of the hydrophobic structural unit include a structural unit having a linear alkyl group, a structural unit having a cyclic alkyl group, a structural unit having an aryl group, a structural unit having a hydroxyalkyl group, a structural unit having a lactone-modified hydroxy group, a structural unit having an alkoxyalkyl group, a structural unit having an amino group, a structural unit having an epoxy group, a structural unit having an oxygen-containing heterocyclic group, a structural unit having an amide group, and a structural unit derived from a hydrophobic vinyl monomer other than the (meth)acrylic monomer. The hydrophobic structural unit may be used alone or in combination of two or more.

[0026] Examples of the structural unit having a linear alkyl group include a structural unit derived from a (meth)acrylate having a linear alkyl group and a structural unit derived from a (meth)acrylate having a branched alkyl group.

[0027] Examples of the (meth)acrylate having a 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, and n-stearyl (meth)acrylate. The number of carbon atoms of the linear alkyl group is preferably 1 to 20, more preferably 1 to 10, and still more preferably 1 to 5.

[0028] Examples of the (meth)acrylate having a 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, etc. The number of carbon atoms of the branched-chain alkyl group is preferably 3 to 20, more preferably 3 to 12, and even more preferably 3 to 10.

[0029] Examples of the structural unit having a cyclic alkyl group include a structural unit derived from a (meth)acrylate having a cyclic alkyl group with a monocyclic structure, a structural unit derived from a (meth)acrylate of a cyclic alkyl group having a bridged-ring structure, etc. The cyclic alkyl group may have a chain portion.

[0030] Examples of the (meth)acrylate having a cyclic alkyl group with a monocyclic structure include cyclic alkyl (meth)acrylates such as cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, cyclododecyl (meth)acrylate, etc. The number of carbon atoms of the cyclic alkyl group with a monocyclic structure is preferably 6 to 20, more preferably 6 to 12.

[0031] Examples of the (meth)acrylate of a cyclic alkyl group having a bridged-ring structure include bornyl (meth)acrylate, isobornyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2-adamantyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, 2-ethyl-2-adamantyl (meth)acrylate, norbornyl (meth)acrylate, etc. The number of carbon atoms of the cyclic alkyl group having a bridged-ring structure is preferably 6 to 20, more preferably 6 to 12.

[0032] Examples of the structural unit having an aryl group include structural units derived from (meth)acrylates having an aryl group. The aryl group may have a chain portion such as an alkylaryl group, an aralkyl group, or an aryloxyalkyl group. 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 an aryl group include phenyl (meth)acrylate, benzyl (meth)acrylate, and phenoxyethyl (meth)acrylate. The number of carbon atoms of the aryl group is preferably 6 to 12, more preferably 6 to 9.

[0033] Examples of the structural unit having a hydroxyalkyl group include structural units derived from (meth)acrylates having a hydroxyalkyl group. The hydroxyalkyl group is an alkyl group in which at least one hydrogen atom is substituted with a hydroxy group. Examples of the (meth)acrylate having a hydroxyalkyl group include 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, and (4-hydroxymethylcyclohexyl) (meth)acrylate. The hydroxyalkyl group is preferably linear or branched. The number of carbon atoms of the hydroxyalkyl group is preferably 1 to 10, more preferably 1 to 5.

[0034] Examples of the structural unit having a lactone-modified hydroxy group include structural units derived from (meth)acrylates having a lactone-modified hydroxy group. Examples of the (meth)acrylate having a lactone-modified hydroxy group include those obtained by adding a lactone to the (meth)acrylate having a hydroxyalkyl group, and those obtained by adding caprolactone are preferred. The addition amount of the lactone is preferably from 1 mol to 10 mol, more preferably from 1 mol to 5 mol. Examples of the (meth)acrylate having a lactone-modified hydroxy group include a 1 mol adduct of caprolactone to 2-hydroxyethyl (meth)acrylate, a 2 mol adduct of caprolactone to 2-hydroxyethyl (meth)acrylate, a 3 mol adduct of caprolactone to 2-hydroxyethyl (meth)acrylate, a 4 mol adduct of caprolactone to 2-hydroxyethyl (meth)acrylate, a 5 mol adduct of caprolactone to 2-hydroxyethyl (meth)acrylate, and a 10 mol adduct of caprolactone to 2-hydroxyethyl (meth)acrylate, etc. are preferred.

[0035] Examples of the structural unit having an alkoxyalkyl group include a structural unit derived from a (meth)acrylate having an alkoxyalkyl group. Examples of the (meth)acrylate having an alkoxyalkyl group include 2-methoxyethyl (meth)acrylate and 2-ethoxyethyl (meth)acrylate.

[0036] Examples of the structural unit having an amino group include a structural unit derived from a (meth)acrylate having an amino group. Examples of the (meth)acrylate having an 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, and propylaminobutyl (meth)acrylate.

[0037] Examples of the structural unit having an epoxy group include a structural unit derived from a (meth)acrylate having an epoxy group. Examples of the (meth)acrylate having an epoxy group include glycidyl (meth)acrylate, (3,4-epoxycyclohexyl)methyl (meth)acrylate, and the like.

[0038] Examples of the structural unit having an oxygen-containing heterocyclic group include a structural unit derived from a (meth)acrylate having an oxygen-containing heterocyclic group. Examples of the (meth)acrylate having an oxygen-containing heterocyclic group include tetrahydrofurfuryl (meth)acrylate, (3-ethyloxetan-3-yl)methyl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (5-ethyl-1,3-dioxan-5-yl)methyl (meth)acrylate, 2-[(2-tetrahydropyranyl)oxy]ethyl (meth)acrylate, (1,3-dioxan-5-yl)methyl (meth)acrylate, 4-(meth)acryloylmorpholine, and the like. The oxygen-containing heterocyclic group is preferably a 4- to 6-membered ring.

[0039] Examples of the structural unit having an amide group include a structural unit derived from (meth)acrylamides. 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. (Meth)acrylamides are (meth)acrylic monomers but are not included in (meth)acrylate monomers.

[0040] Examples of hydrophobic vinyl monomers other than (meth)acrylic monomers include styrene-based monomers, vinyl monomers containing an epoxy group, vinyl monomers having a nitrogen-containing heterocyclic group, vinyl monomers having a sulfur-containing heterocyclic group, vinyl amides, nitriles, vinyl carboxylic acids, α-olefins, dienes, vinyl halide monomers, and the like.

[0041] Examples of the styrene-based monomers include substituted or unsubstituted styrene. Substituents that may substitute styrene include an alkyl group, an aryl group, an alkoxy group, an aryloxy group, and the like. The styrene-based monomers also include condensed cyclic compounds having two or more benzene rings. Examples of the styrene-based monomers include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-dimethylstyrene, 4-methoxystyrene, 4-phenylstyrene, 1-vinylnaphthalene, and the like. Preferably, they are styrene or styrene having an alkyl group. The number of carbon atoms of the alkyl group in the styrene having an alkyl group is preferably 1 to 6.

[0042] Examples of the vinyl monomers containing an epoxy group include 2-allyloxirane, glycidyl vinyl ether, 3,4-epoxycyclohexyl vinyl ether, and the like.

[0043] Examples of the vinyl monomers having a nitrogen-containing heterocyclic group include vinyl monomers having a 5-membered lactam group such as N-vinylpyrrolidone, N-vinyl-5-methylpyrrolidone, N-vinyl-5-ethylpyrrolidone, N-vinyl-5-propylpyrrolidone, N-vinyl-5-butylpyrrolidone, 1-(2-propenyl)-2-pyrrolidone; vinyl monomers having a 6-membered lactam group such as N-vinylpiperidone; vinyl monomers having a 7-membered lactam group such as N-vinylcaprolactam; 2-vinylpyridine, 4-vinylpyridine; vinylpyrrole; 1-vinylimidazole, and the like. Among these, vinyl monomers having a 5-membered lactam group are preferred, and N-vinylpyrrolidone is more preferred.

[0044] Examples of the vinyl monomer having a sulfur-containing heterocyclic group include 2-vinylthiophene. Examples of the vinylamides include N-vinylformamide and N-vinylacetamide. Examples of the nitriles include acrylonitrile and methacrylonitrile. Examples of the vinyl carboxylate include vinyl acetate, vinyl pivalate, and vinyl benzoate. Examples of the α-olefin include 1-hexene, 1-octene, and 1-decene. Examples of the dienes include butadiene, isoprene, 4-methyl-1,4-hexadiene, and 7-methyl-1,6-octadiene. Examples of the vinyl halide monomer include vinyl fluoride, vinylidene fluoride, trifluoroethylene, tetrafluoroethylene, tetrafluoropropylene, hexafluoropropylene, vinyl chloride, vinylidene chloride, 1-chloro-1-fluoroethylene, 1,2-dichloro-1,2-difluoroethylene, and chlorotrifluoroethylene.

[0045] The hydrophobic vinyl monomer may be used alone or in combination of two or more. The hydrophobic vinyl monomer is preferably at least one vinyl monomer selected from the group consisting of (meth)acrylate having a chain alkyl group, (meth)acrylate having a cyclic alkyl group, (meth)acrylate having an aryl group, (meth)acrylate having a hydroxyalkyl group, (meth)acrylate having a lactone-modified hydroxy group, (meth)acrylate having an alkoxyalkyl group, (meth)acrylate having an oxygen-containing heterocyclic group, (meth)acrylamides, styrene monomers, and vinyl monomers having a nitrogen-containing heterocyclic group, more preferably at least one vinyl monomer selected from the group consisting of (meth)acrylate having a chain alkyl group, (meth)acrylate having a cyclic alkyl group, (meth)acrylate having an aryl group, and vinyl monomers having a nitrogen-containing heterocyclic group.

[0046] The amphiphilic polymer preferably has a content of the hydrophilic structural unit (a) of 3 mol% or more, more preferably 10 mol% or more, still more preferably 17 mol% or more, particularly preferably 19 mol% or more, and preferably 60 mol% or less, more preferably 45 mol% or less, still more preferably 30 mol% or less, in 100 mol% of all the structural units constituting the amphiphilic polymer.

[0047] The amphiphilic polymer preferably has a content of the hydrophobic structural unit (b) of 40 mol% or more, more preferably 55 mol% or more, still more preferably 70 mol% or more, and preferably 97 mol% or less, more preferably 90 mol% or less, still more preferably 83 mol% or less, particularly preferably 81 mol% or less, in 100 mol% of all the structural units constituting the amphiphilic polymer.

[0048] Examples of the amphiphilic polymer include neutralized products of copolymers containing a structural unit (a1) derived from a vinyl monomer having an acidic group and a structural unit (b1) derived from a hydrophobic vinyl monomer. As the vinyl monomer having an acidic group, a (meth)acrylic monomer having an acidic group is preferable, more preferably a (meth)acrylic monomer having a carboxy group, and still more preferably (meth)acrylic acid.

[0049] The copolymer preferably has a content of the structural unit (a1) derived from a vinyl monomer having an acidic group of 3 mol% or more, more preferably 10 mol% or more, still more preferably 17 mol% or more, particularly preferably 19 mol% or more, and preferably 60 mol% or less, more preferably 45 mol% or less, still more preferably 30 mol% or less, in 100 mol% of all the structural units constituting the copolymer.

[0050] Other examples of the amphiphilic polymer include, for example, a copolymer containing a structural unit (a2) derived from a vinyl monomer having a polyalkylene glycol group and a structural unit (b1) derived from a hydrophobic vinyl monomer, and a copolymer containing a structural unit (a1) derived from a vinyl monomer having an acidic group, a structural unit (a2) derived from a vinyl monomer having a polyalkylene glycol group, and a structural unit (b1) derived from a hydrophobic vinyl monomer. As the vinyl monomer having a polyalkylene glycol group, (meth)acrylate having a terminal hydroxy group polyalkylene glycol group or (meth)acrylate having an alkoxy polyalkylene glycol group is preferable.

[0051] The content of the structural unit (a2) derived from the vinyl monomer having a polyalkylene glycol group in the copolymer is preferably 3 mol% or more, more preferably 10 mol% or more, still more preferably 17 mol% or more, particularly preferably 19 mol% or more, and preferably 60 mol% or less, more preferably 45 mol% or less, still more preferably 30 mol% or less, in 100 mol% of all the structural units constituting the copolymer.

[0052] The weight average molecular weight (Mw) of the amphiphilic polymer is preferably 5,000 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 30,000 or less, particularly preferably 20,000 or less. The molecular weight of the amphiphilic polymer is measured by gel permeation chromatography (hereinafter referred to as "GPC").

[0053] The molecular weight distribution (Mw / Mn) of the amphiphilic polymer is preferably 3.0 or less, more preferably 2.5 or less, still more preferably 2.0 or less. In the present invention, the molecular weight distribution (Mw / Mn) is determined by (weight average molecular weight (Mw)) / (number average molecular weight (Mn)). The smaller the Mw / Mn, the narrower the molecular weight distribution and the more uniform the polymer in terms of molecular weight. When the value is 1.0, the molecular weight distribution is the narrowest. That is, the lower limit value of Mw / Mn is 1.0.

[0054] When the hydrophilic structural unit (a) has a neutralized acidic group, the acid value of the copolymer before neutralizing the acidic group is 20 mgKOH / g or more, preferably 50 mgKOH / g or more, more preferably 80 mgKOH / g or more, and 250 mgKOH / g or less, preferably 200 mgKOH / g or less, more preferably 150 mgKOH / g or less.

[0055] When the hydrophilic structural unit (a) has a neutralized acidic group, the weight average molecular weight (Mw) of the copolymer before neutralizing the acidic group is preferably 5,000 or more, more preferably 7,500 or more, still more preferably 10,000 or more, and 50,000 or less, preferably 35,000 or less, still more preferably 30,000 or less, particularly preferably 20,000 or less. The molecular weight of the copolymer is measured by gel permeation chromatography (hereinafter referred to as "GPC").

[0056] When the hydrophilic structural unit (a) has a neutralized acidic group, the molecular weight distribution (Mw / Mn) of the copolymer before neutralizing the acidic group is preferably 3.0 or less, more preferably 2.5 or less, still more preferably 2.0 or less. The smaller the Mw / Mn, the narrower the molecular weight distribution and the more uniform the copolymer in terms of molecular weight. When the value is 1.0, the molecular weight distribution is the narrowest. That is, the lower limit value of Mw / Mn is 1.0.

[0057] The amphiphilic polymer may be any of a random copolymer, a block copolymer, and a graft copolymer, and is preferably a block copolymer.

[0058] As the amphiphilic polymer, a block copolymer having an A block containing a hydrophilic structural unit (a) and a B block containing a hydrophobic structural unit (b) is preferable.

[0059] The content of the hydrophilic structural unit (a) in the A block is preferably 10 mol% or more, more preferably 20 mol% or more, still more preferably 25 mol% or more, and preferably 90 mol% or less, more preferably 70 mol% or less, still more preferably 50 mol% or less in 100 mol% of the structural units constituting the A block.

[0060] The A block may contain a hydrophobic structural unit (b). When the A block contains the hydrophobic structural unit (b), the content is preferably 10 mol% or more, more preferably 30 mol% or more, still more preferably 50 mol% or more, and preferably 90 mol% or less, more preferably 80 mol% or less, still more preferably 75 mol% or less in 100 mol% of the structural units constituting the A block.

[0061] When two or more structural units are contained in the A block, the various structural units contained in the A block may be contained in any mode such as random copolymerization or block copolymerization in the A block, and from the viewpoint of uniformity, it is preferably contained in the mode of random copolymerization. For example, the A block may be formed of a copolymer of a structural unit composed of an a1 block and a structural unit composed of an a2 block.

[0062] The content of the hydrophilic structural unit (a) in the B block is preferably 5 mol% or less, more preferably 4 mol% or less, still more preferably 3 mol% or less in 100 mol% of the structural units constituting the B block.

[0063] The B block contains a hydrophobic structural unit (b). The content of the hydrophobic structural unit is preferably 95 mol% or more, more preferably 96 mol% or more, and still more preferably 97 mol% or more in 100 mol% of the structural units constituting the B block.

[0064] When two or more types of structural units are contained in the B block, the various structural units contained in the B block may be contained in any form such as random copolymerization or block copolymerization in the B block, and it is preferably contained in the form of random copolymerization from the viewpoint of uniformity. For example, the B block may be formed of a copolymer of a structural unit composed of a b1 block and a structural unit composed of a b2 block.

[0065] The content of the structural unit constituting the A block is preferably 30 mol% or more, more preferably 40 mol% or more, and still more preferably 50 mol% or more in 100 mol% of all the structural units constituting the block copolymer, and preferably 90 mol% or less, more preferably 85 mol% or less, and still more preferably 80 mol% or less. The content of the structural unit constituting the B block is preferably 10 mol% or more, more preferably 15 mol% or more, and still more preferably 20 mol% or more in 100 mol% of all the structural units constituting the block copolymer, and preferably 70 mol% or less, more preferably 60 mol% or less, and still more preferably 50 mol% or less.

[0066] The molar ratio (A block / B block) of the A block and the B block in the block copolymer is preferably 0.5 or more, more preferably 1.0 or more, preferably 5.0 or less, and more preferably 4.0 or less.

[0067] The structure of the block copolymer is preferably a linear block copolymer. Also, the linear block copolymer may have any structure (sequence), but from the viewpoint of the physical properties of the linear block copolymer or the physical properties of the composition, when the A block is represented as A and the B block is represented as B, (A - B)m Type, (A - B) m -A type and (B - A) m It is preferably a copolymer having at least one structure selected from the group consisting of -B type (m is an integer of 1 or more, for example, an integer of 1 to 3).

[0068] Among these, from the viewpoints of handleability during processing and physical properties of the composition, A - B type diblock copolymer, A - B - A type triblock copolymer, and B - A - B type triblock copolymer are preferable. In the case of a triblock copolymer represented by A - B - A, the two A blocks located at both ends may be the same as or different from each other. Also, in the case of a triblock copolymer represented by B - A - B, the two B blocks located at both ends may be the same as or different from each other. The block copolymer may have other blocks other than the A block and the B block.

[0069] When the block copolymer is an A1 - B - A2 triblock copolymer, the molar ratio (A1 / A2) is preferably 0.5 or more, more preferably 0.9 or more, preferably 1.5 or less, and more preferably 1.1 or less. When the block copolymer is a B1 - A - B2 triblock copolymer, the molar ratio (B1 / B2) is preferably 0.5 or more, more preferably 0.9 or more, preferably 1.5 or less, and more preferably 1.1 or less.

[0070] (Specific Example 1) As the amphiphilic polymer, a neutralized product of a block copolymer (X) having an A block containing a structural unit (a1) derived from a vinyl monomer having an acidic group and a B block containing a structural unit (b1) derived from a hydrophobic vinyl monomer is preferable. Here, the block copolymer (X) is the copolymer before neutralizing the acidic group and is the precursor of the amphiphilic polymer.

[0071] The acid value of the block copolymer (X) is 20 mgKOH / g or more, preferably 50 mgKOH / g or more, more preferably 80 mgKOH / g or more, and 250 mgKOH / g or less, preferably 200 mgKOH / g or less, more preferably 150 mgKOH / g or less.

[0072] The weight average molecular weight (Mw) of the block copolymer (X) is preferably 5,000 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 30,000 or less, particularly preferably 20,000 or less.

[0073] The molecular weight distribution (Mw / Mn) of the block copolymer (X) is preferably 3.0 or less, more preferably 2.5 or less, still more preferably 2.0 or less.

[0074] As the structural unit (a1) derived from the vinyl monomer having an acidic group, a structural unit derived from a (meth)acrylic monomer having an acidic group is preferable, more preferably a structural unit derived from a (meth)acrylic monomer having a carboxy group, and still more preferably a structural unit derived from (meth)acrylic acid.

[0075] As the structural unit (b1) derived from the hydrophobic vinyl monomer, a structural unit derived from at least one vinyl monomer selected from the group consisting of (meth)acrylates having a chain alkyl group, (meth)acrylates having a cyclic alkyl group, (meth)acrylates having an aryl group, (meth)acrylates having a hydroxyalkyl group, (meth)acrylates having a lactone-modified hydroxy group, (meth)acrylates having an alkoxyalkyl group, (meth)acrylates having an oxygen-containing heterocyclic group, (meth)acrylamides, styrene-based monomers, and vinyl monomers having a nitrogen-containing heterocyclic group is preferable, and more preferably a structural unit derived from at least one vinyl monomer selected from the group consisting of (meth)acrylates having a chain alkyl group, (meth)acrylates having a cyclic alkyl group, (meth)acrylates having an aryl group, and vinyl monomers having a nitrogen-containing heterocyclic group.

[0076] (Specific Example 2) As the amphiphilic polymer, a block copolymer (Y) having an A block containing a structural unit (a2) derived from a vinyl monomer having a polyalkylene glycol group and a B block containing a structural unit (b1) derived from a hydrophobic group vinyl monomer is preferable.

[0077] , The weight average molecular weight (Mw) of the block copolymer (Y) is preferably 5,000 or more, more preferably 7,500 or more, still more preferably 10,000 or more, preferably 50,000 or less, more preferably 35,000 or less, still more preferably 30,000 or less, and particularly preferably 20,000 or less.

[0078] The molecular weight distribution (Mw / Mn) of the block copolymer (Y) is preferably 3.0 or less, more preferably 2.5 or less, and still more preferably 2.0 or less.

[0079] As the vinyl monomer having a polyalkylene glycol group, (meth)acrylate having a terminal hydroxy group polyalkylene glycol group or (meth)acrylate having an alkoxy polyalkylene glycol group is preferable.

[0080] As the structural unit (b1) derived from the hydrophobic vinyl monomer, a structural unit derived from at least one vinyl monomer selected from the group consisting of (meth)acrylate having a linear alkyl group, (meth)acrylate having a cyclic alkyl group, (meth)acrylate having an aryl group, (meth)acrylate having a hydroxyalkyl group, (meth)acrylate having a lactone-modified hydroxy group, (meth)acrylate having an alkoxyalkyl group, (meth)acrylic monomer having an oxygen-containing heterocyclic group, (meth)acrylamides, styrene-based monomers and vinyl monomers having a nitrogen-containing heterocyclic group is preferable, and more preferably a structural unit derived from at least one vinyl monomer selected from the group consisting of (meth)acrylate having a linear alkyl group, (meth)acrylate having a cyclic alkyl group, (meth)acrylate having an aryl group and vinyl monomers having a nitrogen-containing heterocyclic group.

[0081] (Polymerization method) The amphiphilic polymer or the copolymer serving as its precursor can be produced by polymerizing the monomer using a conventionally known polymerization method. When the amphiphilic polymer or the copolymer serving as its precursor is a diblock copolymer, the vinyl monomer can be polymerized by a conventionally known polymerization method, such as a method of first producing the A block and then polymerizing the monomer of the B block to the A block; a method of first producing the B block and then polymerizing the monomer of the A block to the B block. When the amphiphilic polymer or the copolymer serving as its precursor is a triblock copolymer, the vinyl monomer can be polymerized by a conventionally known polymerization method, such as a method of first producing the A1 block, then polymerizing the monomer of the B block to the A1 block to produce the A1-B block, and then polymerizing the monomer of the A2 block to the A1-B block; a method of first producing the B1 block, then polymerizing the monomer of the A block to the B1 block to produce the B1-A block, and then polymerizing the monomer of the B2 block to the B1-A block.

[0082] Examples of the polymerization method include radical polymerization method (also referred to as free radical polymerization method), cationic polymerization method, anionic polymerization method, living polymerization method, etc. Among these, the living polymerization method is preferred. That is, as the amphiphilic polymer (for example, block copolymer (Y)) or the copolymer (for example, block copolymer (X)) serving as its precursor, those polymerized by the living polymerization method are preferred.

[0083] In the living polymerization method, among the four elementary reactions of initiation reaction, propagation reaction, termination reaction, and chain transfer reaction in chain polymerization, side reactions such as termination reaction and chain transfer reaction are not substantially involved, and the vinyl monomer reacts without the reaction point (polymerization growth end) being deactivated, and the polymer chain grows. Therefore, a polymer with a narrow molecular weight distribution and a uniform composition can be produced. The living polymerization method includes living radical polymerization method, living anionic polymerization method, living cationic polymerization method, etc. Among these, from the viewpoint of polymerization simplicity, the living radical polymerization method is preferred. In addition, the living radical polymerization method is also preferred in that it maintains the simplicity and versatility of the free radical polymerization method, and it is easy to precisely control the molecular weight distribution and produce a polymer with a uniform composition.

[0084] (Free radical polymerization method) For the free radical polymerization method, a conventionally known method may be adopted. Examples of the polymerization initiator used in the free radical polymerization method include azo-based polymerization initiators and peroxide-based polymerization initiators. Examples of the azo-based polymerization initiator include 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), etc.

[0085] The polymerization reaction can be carried out without a solvent, but it may also be carried out by using an aprotic solvent or a protic solvent generally used in radical polymerization and stirring a mixture of vinyl monomers. Examples of the aprotic solvent include acetonitrile, methyl ethyl ketone, anisole, benzene, toluene, propylene glycol monomethyl ether acetate, ethyl acetate, tetrahydrofuran (THF), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), acetone, dioxane, chloroform, carbon tetrachloride, and the like. Examples of the protic solvent include water, methanol, ethanol, isopropanol, n-butanol, ethyl cellosolve, butyl cellosolve, 1-methoxy-2-propanol, hexafluoroisopropanol, diacetone alcohol, and the like. The solvent may be used alone or in combination of two or more.

[0086] The amount of the solvent used may be adjusted as appropriate. For example, with respect to 1 g of the vinyl monomer, it is preferably 0.01 mL to 50 mL, more preferably 0.05 mL to 10 mL, and still more preferably 0.1 mL to 1 mL.

[0087] The reaction temperature and reaction time may be appropriately adjusted according to the molecular weight or molecular weight distribution of the obtained copolymer. Usually, the reaction is carried out at 0°C to 150°C with stirring for 1 minute to 100 hours. At this time, the pressure is usually normal pressure, but it may be increased or decreased.

[0088] (Living Radical Polymerization Method) In living radical polymerization methods, depending on the method of stabilizing the polymerization growing end, there are methods using compounds capable of generating nitroxide radicals (nitroxide method; NMP method); methods using metal complexes such as copper and ruthenium, with a halogenated compound as a polymerization initiation compound and polymerizing it livingly from the polymerization initiation compound (ATRP method); methods using dithiocarboxylic acid esters or xanthate compounds (RAFT method); methods using organic tellurium compounds (TERP method); methods using organic iodine compounds (ITP method); methods using an iodine compound as a polymerization initiation compound and an organic compound such as a phosphorus compound, nitrogen compound, oxygen compound, or hydrocarbon as a catalyst (reversible transfer catalyst polymerization; RTCP method, reversible catalyst-mediated polymerization; RCMP method), etc. Among these, from the viewpoints of the diversity of monomers that can be used, molecular weight control in the polymer region, and uniform composition or coloring, it is preferable to use the TERP method.

[0089] The TERP method is a method of polymerizing a radically 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, International Publication No. 2004 / 096870, and International Publication No. 2020 / 116144.

[0090] Specific polymerization methods of the TERP method include the following (a) to (d). (a) A method of polymerizing a vinyl monomer using an organic tellurium compound represented by formula (Z1). (b) A method of polymerizing a vinyl monomer using a mixture of an organic tellurium compound represented by formula (Z1) and an azo-based polymerization initiator. (c) A method of polymerizing a vinyl monomer using a mixture of an organic tellurium compound represented by formula (Z1) and an organic ditelluride compound represented by formula (Z2). (d) A method of polymerizing a vinyl monomer using a mixture of an organic tellurium compound represented by formula (Z1), an azo-based polymerization initiator, and an organic ditelluride compound represented by formula (Z2).

[0091] [Chemical formula] [In formula (Z1), R a represents an alkyl group, aryl group, or aromatic heterocyclic group having 1 to 8 carbon atoms. R b and R c each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. R d represents 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. [In formula (Z2), R a represents an alkyl group, aryl group, or aromatic heterocyclic group having 1 to 8 carbon atoms. ]

[0092] Specific examples of the organic tellurium compound represented by formula (Z1) include ethyl = 2-methyl-2-n-butyltellanyl-propionate, ethyl = 2-n-butyltellanyl-propionate, (2-hydroxyethyl) = 2-methyl-methyltellanyl-propionate, etc., and the organic tellurium compounds described in International Publication No. 2004 / 14848, International Publication No. 2004 / 14962, International Publication No. 2004 / 072126, International Publication No. 2004 / 096870, and International Publication No. 2020 / 116144. Specific examples of the organic ditelluride compound represented by formula (Z2) include dimethylditelluride, dibutylditelluride, etc.

[0093] The azo polymerization initiator can be used without particular limitation as long as it is an azo polymerization initiator used in ordinary radical polymerization, and examples thereof include 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.

[0094] In the polymerization step, in a container substituted with an inert gas, a vinyl monomer, an organic tellurium compound of the formula (Z1), and, depending on the type of the vinyl monomer, for the purposes of promoting the reaction, controlling the molecular weight and molecular weight distribution, etc., an azo polymerization initiator and / or an organic ditelluride compound of the formula (Z2) are further mixed. At this time, examples of the inert gas include nitrogen, argon, helium, etc. Preferably, they are argon and nitrogen. The amount of the vinyl monomer used in the above (a), (b), (c), and (d) may be appropriately adjusted according to the physical properties of the target polymer component.

[0095] The polymerization reaction can be carried out without a solvent, or it may be carried out by using an aprotic solvent or a protic solvent commonly used in radical polymerization and stirring the mixture. Examples of the aprotic solvent include acetonitrile, methyl ethyl ketone, anisole, benzene, toluene, propylene glycol monomethyl ether acetate, ethyl acetate, tetrahydrofuran (THF), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), acetone, dioxane, chloroform, carbon tetrachloride, etc. Examples of the protic solvent include, for example, water, methanol, ethanol, isopropanol, n-butanol, ethyl cellosolve, butyl cellosolve, 1-methoxy-2-propanol, hexafluoroisopropanol, diacetone alcohol, etc. The solvent may be used alone or in combination of two or more. The amount of the solvent used may be adjusted as appropriate. For example, 0.01 mL to 50 mL is preferable with respect to 1 g of the vinyl monomer. In the polymerization reaction, in addition to the solvent, a surfactant and / or a dispersant can also be used.

[0096] The reaction temperature and the reaction time may be appropriately adjusted according to the molecular weight or the molecular weight distribution of the obtained copolymer, but usually, it is stirred 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. Further, the polymerization reaction may be carried out by light irradiation.

[0097] The polymer growth terminal of the polymer obtained by the polymerization reaction is -TeR derived from a tellurium compound a is (wherein R ais in the same form as described above), and is removed from the polymerization growth end by operations in air after the polymerization reaction, but tellurium atoms may remain. Since the polymer with tellurium atoms remaining at the end may be colored or have poor thermal stability, it is preferable to remove the tellurium atoms. Examples of methods for removing tellurium atoms include radical reduction methods; methods of adsorbing with activated carbon or the like; methods of adsorbing metals with ion exchange resins or the like, and these methods can also be used in combination. Note that the other end of the polymer obtained by the polymerization reaction (the end opposite to the polymerization growth end) is -CR derived from the tellurium compound b R c R d (wherein R b 、R c and R d are the same as R b 、R c and R d in formula (Z1).). Therefore, the polymer obtained by the TERP method does not have a substituent containing a sulfur atom at the end.

[0098] (Liquid separation treatment) For the reaction solution after the polymerization reaction, liquid separation treatment may be performed. By performing liquid separation treatment, impurities in the reaction solution can be reduced. In the liquid separation treatment, a hydrophilic organic solvent and a hydrophobic organic solvent are added to the reaction solution after the polymerization reaction and mixed, and then separated into a hydrophobic organic solvent phase and a hydrophilic organic solvent phase, and the hydrophobic organic solvent phase is removed to obtain a hydrophilic organic solvent phase containing the polymer.

[0099] The hydrophobic organic solvent is an organic solvent that is immiscible with the hydrophilic organic solvent. The hydrophobic organic solvent preferably does not dissolve an amphiphilic polymer (for example, block copolymer (Y)) or a copolymer (for example, block copolymer (X)) that is a precursor thereof, and does not react with the amphiphilic polymer or a copolymer that is a precursor thereof. Further, the hydrophobic organic solvent preferably has an SP value of less than 9.3.

[0100] 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. Further, a mixed solvent thereof may also be used. When the hydrophobic organic solvent is a mixed solvent, a liquid composition having an SP value of less than 9.3 is preferred. The SP value of the mixed solvent can be calculated as the sum of the products of the SP values of the respective solvents and their volume fractions.

[0101] The difference (SP1 - SP2) between the SP value (SP1) of the hydrophilic organic solvent and the SP value (SP2) of the hydrophobic organic solvent is preferably 1.0 or more, more preferably 3.0 or more, and even more preferably 5.0 or more. When the difference (SP1 - SP2) is 1.0 or more, the separation of the hydrophobic organic solvent phase and the hydrophilic organic solvent phase can be carried out more easily. The upper limit of the difference (SP1 - SP2) is not particularly limited, but is usually about 8.0.

[0102] (Neutralization treatment) The copolymer (for example, block copolymer (X)) that becomes the precursor of the amphiphilic polymer after polymerization becomes an amphiphilic polymer by neutralizing at least a part of the acidic groups possessed by the copolymer with a basic component. The neutralization can be carried out, for example, by adding an aqueous solution of a basic component to the reaction solution after polymerization or the hydrophilic organic solvent phase after liquid separation treatment and mixing them.

[0103] Examples of the basic component include hydroxides of alkali metals, hydroxides of alkaline earth metals, aliphatic amine compounds, alcohol amines, ammonia, etc. One of these may be used, or a plurality may be combined. As the basic component, hydroxides of alkali metals and hydroxides of alkaline earth metals are preferable, and hydroxides of alkali metals are more preferable. Examples of the alkali metal include lithium, sodium, potassium, rubidium, cesium, and francium. Examples of the alkaline earth metal include magnesium, calcium, strontium, barium, and radium.

[0104] Examples of the hydroxide of the alkali metal include lithium hydroxide, sodium hydroxide, and potassium hydroxide, and preferably sodium hydroxide and potassium hydroxide. Examples of the hydroxide of the alkaline earth metal include beryllium hydroxide, magnesium hydroxide, calcium hydroxide, and strontium hydroxide. Examples of the aliphatic amine compound include monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, and triethylamine, and preferably triethylamine. Examples of the alcohol amine compound include monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, methylethanolamine, dimethylethanolamine, and N-methyldiethanolamine. Tertiary amines are preferable, and triethanolamine is more preferable.

[0105] These basic components are added as an aqueous solution. The concentration of the basic component in the aqueous solution is preferably 1.0 mass% to 50 mass%.

[0106] When neutralizing a part of the acidic groups of the copolymer (for example, block copolymer (X)) that serves as a precursor of the amphiphilic polymer, the degree of neutralization of the acidic groups is preferably 20 mol% or more, more preferably 30 mol% or more, still more preferably 35 mol% or more, and preferably 100 mol% or less, more preferably 95 mol% or less, still more preferably 90 mol% or less.

[0107] The solution obtained by performing the liquid separation treatment and the neutralization treatment is a mixed solution containing the amphiphilic polymer (for example, the neutralized product of the copolymer (block copolymer (X)), block copolymer (Y)), a hydrophilic organic solvent, and water.

[0108] (Mixed solution) The mixed solution to be subjected to the distillation-off step may contain an amphiphilic polymer, a hydrophilic organic solvent, and water, but the content of the amphiphilic polymer, the content of water, the content of the hydrophilic organic solvent, and the viscosity in the mixed solution are preferably within the following numerical ranges before the start of distillation.

[0109] The content of the amphiphilic polymer in the mixed solution (before the start of distillation) is preferably 50 g / L or more, more preferably 75 g / L or more, still more preferably 100 g / L or more, and preferably 800 g / L or less, more preferably 500 g / L or less, still more preferably 300 g / L or less.

[0110] The content of water in the mixed solution (before the start of distillation) is preferably 50 parts by mass or more, more preferably 100 parts by mass or more, still more preferably 150 parts by mass or more, and preferably 700 parts by mass or less, more preferably 600 parts by mass or less, still more preferably 500 parts by mass or less with respect to 100 parts by mass of the amphiphilic polymer.

[0111] The content of the hydrophilic organic solvent in the mixed solution (before the start of distillation) is preferably 1 part by mass or more, more preferably 5 parts by mass or more, still more preferably 10 parts by mass or more, and preferably 300 parts by mass or less, more preferably 250 parts by mass or less, still more preferably 200 parts by mass or less with respect to 100 parts by mass of the amphiphilic polymer.

[0112] The viscosity (at 25°C) of the mixed solution (before the start of distillation) is preferably 10,000 mPa·s or less, more preferably 5,000 mPa·s or less, and even more preferably 1,000 mPa·s or less. If the viscosity is 10,000 mPa·s or less, stirring can be carried out without imposing a burden on the equipment and instruments. The lower limit of the viscosity of the mixed solution is not particularly limited, but is usually 1 mPa·s.

[0113] 〔Distillation step〕 In the distillation step, the hydrophilic organic solvent is distilled off from the mixed solution containing the amphiphilic polymer, the hydrophilic organic solvent, and water by a distillation method. The distillation method is a method of separating the components in a mixture by utilizing the difference in the boiling points of the components.

[0114] In the distillation step, distillation is carried out while introducing a gas fluid into the gas phase part of the system. By distilling while introducing a gas fluid into the gas phase part, the hydrophilic organic solvent can be efficiently distilled off while suppressing foaming.

[0115] It is important that the gas fluid promotes the discharge of the solvent molecules present in the gas phase part of the system to the outside of the system (outside the distillation vessel). Therefore, the position where the gas fluid is introduced is not particularly limited as long as it can promote the discharge of the solvent molecules present in the gas phase part of the system to the outside of the system (outside the distillation vessel) in the gas phase part of the system, and it may be near the liquid surface of the mixed solution or away from the liquid surface. In the distillation step, the gas fluid is not introduced into the liquid phase part (inside the mixed solution) of the system.

[0116] The gas fluid is preferably an inert gas or a mixed gas of an inert gas and air. Examples of the inert gas include nitrogen gas, helium gas, neon gas, argon gas, etc. When using a mixed gas of the inert gas and air, the volume ratio of the inert gas in the mixed gas is preferably 50% by volume or more, more preferably 65% by volume or more, and even more preferably 80% by volume or more.

[0117] The water content of the gas fluid is preferably 2.5% by volume or less, more preferably 1.5% by volume or less, and even more preferably 0.01% by volume or less. If the water content of the gas fluid is 2.5% by volume or less, the hydrophilic organic solvent can be efficiently distilled off.

[0118] The introduction amount of the gas fluid is preferably 0.2 m 3 / (min·m 2 ) or more, more preferably 0.5 m 3 / (min·m 2 ) or more, even more preferably 0.8 m 3 / (min·m 2 ) or more, particularly preferably 1.5 m 3 / (min·m 2 ) or more, and preferably 4.0 m 3 / (min·m 2 ) or less, more preferably 3.7 m 3 / (min·m 2 ) or less. By adjusting the introduction amount within the above range, the hydrophilic organic solvent can be efficiently distilled off.

[0119] The distillation-off step is carried out under atmospheric pressure, that is, in an open system. By carrying out the distillation-off step in an open system, the hydrophilic organic solvent can be efficiently distilled off while suppressing foaming. Note that the open system is a system that allows the transfer of substances and energy between the inside and the outside of the distillation system in which the distillation-off step is carried out. Note that in the distillation-off step, positive pressurization or depressurization is not carried out on the system, but the pressure inside the system may change due to temperature changes or the like. In this case, in the distillation-off step, the pressure inside the system is preferably 81.33 kPa or more, more preferably 86.33 kPa or more, even more preferably 101.33 kPa or more, and preferably 121.33 kPa or less, more preferably 116.33 kPa or less.

[0120] The volume ratio of the mixed solution to the capacity of the container used in the distillation step is preferably 10% by volume or more, more preferably 20% by volume or more, still more preferably 30% by volume or more, and preferably 90% by volume or less, more preferably 75% by volume or less, still more preferably 60% by volume or less.

[0121] The heating temperature (T1) of the mixed solution in the distillation step is less than 100 °C, preferably 98 °C or less. If the heating temperature (T1) is less than 100 °C, the hydrophilic organic solvent can be efficiently distilled off while suppressing foaming. The heating temperature (T1) of the mixed solution is not particularly limited as long as it is a temperature at which the hydrophilic organic solvent can be distilled off, but it is preferably 50 °C or more, more preferably 65 °C or more, still more preferably 80 °C or more.

[0122] The temperature (T2) of the gas fluid is preferably 5 °C or more, more preferably 10 °C or more, still more preferably 50 °C or more, and preferably less than 100 °C, more preferably 99 °C or less, still more preferably 98 °C or less. If the temperature (T2) of the gas fluid is 5 °C or more, the hydrophilic organic solvent can be efficiently distilled off by suppressing foaming due to the vapor pressure drop, and if it is less than 100 °C, the hydrophilic organic solvent can be efficiently distilled off by suppressing foaming caused by internal evaporation of the mixed solution. The temperature of the gas fluid can be adjusted, for example, by flowing the gas fluid through a heated or cooled copper coil tube.

[0123] The temperature difference (T2 - T1) between the temperature (T2) of the gas fluid and the heating temperature (T1) of the mixed solution is preferably -95 °C or more, more preferably -90 °C or more, still more preferably -85 °C or more, and preferably 20 °C or less, more preferably 15 °C or less. If the temperature difference (T2 - T1) is within the above range, the hydrophilic organic solvent can be efficiently distilled off by suppressing foaming.

[0124] The time of the distillation step is not particularly limited, and it may be carried out to a sufficient extent to remove the hydrophilic organic solvent. The content rate of the hydrophilic organic solvent in the amphiphilic polymer aqueous solution obtained after the distillation is preferably 1.0% by mass or less, more preferably 0.8% by mass or less, and still more preferably 0.5% by mass or less.

[0125] In the distillation step, the vapor of the distilled hydrophilic organic solvent is condensed by a condenser and recovered. Further, the gas fluid introduced into the gas phase part is discharged out of the system together with the distilled hydrophilic organic solvent, but this gas fluid may be recovered and reused.

[0126] Referring to FIG. 1, an example of a distillation apparatus used when performing distillation in the distillation step will be described. FIG. 1 is a schematic cross-sectional view showing an example of the distillation apparatus.

[0127] The distillation apparatus includes a distillation vessel 1 for containing a mixed solution and a heating device 2 for heating the mixed solution 6 in the distillation vessel 1. The distillation vessel 1 has a discharge path 3 for discharging vapor and an introduction path 4 for introducing waste fluid. The mixed solution 6 is placed in the distillation vessel 1, the space occupied by the mixed solution 6 is the liquid phase part 10, and the space where the mixed solution 6 in the distillation vessel 1 does not exist is the gas phase part 20. Note that the distillation vessel 1 may be provided with a stirring member 5 for stirring the mixed solution 10.

[0128] In the distillation step, while introducing a gas fluid into the gas phase part 20 of the distillation vessel 1 containing the mixed solution 6, the mixed solution 6 is heated to perform distillation. The position where the gas fluid is introduced is not particularly limited as long as it is in the gas phase part 20 in the system (inside the distillation vessel), and it may be near the liquid level of the mixed solution or away from the liquid level. In addition, it is preferable to adjust the position of the tip 4a of the introduction path 4 so that the gas fluid can promote the discharge of the solvent molecules existing in the gas phase part to the outside of the system (outside the distillation vessel) in the gas phase part in the system. That is, the tip 4a of the introduction path 4 is preferably separated from the discharge path 3. Further, in the distillation step, no gas fluid is introduced into the liquid phase part 10 (inside the mixed solution 6) in the system. That is, the tip 4a of the introduction path 4 is adjusted to be located in the gas phase part 20 instead of the liquid phase part 10.

Examples

[0129] 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. In addition, various physical property measurements in the examples and comparative examples were carried out according to the following methods.

[0130] The meanings of the abbreviations are as follows. BTEE: Ethyl = 2-methyl-2-n-butyltellanyl-propionate DBDT: Dibutylditelluride AIBN: 2,2’-Azobis(isobutyronitrile) BMA: n-Butyl methacrylate MMA: Methyl methacrylate MAA: Methacrylic acid BzMA: Benzyl methacrylate BA: n-Butyl acrylate M11EGA: Polyethylene glycol (degree of polymerization = 11) methyl ether acrylate (manufactured by Green Co., Ltd., KOMERATE-A040TT) VP: N-Vinyl-2-pyrrolidone CHA: Cyclohexyl acrylate MEK: Methyl ethyl ketone ACN: Acetonitrile MeOH: Methanol PMA: Propylene glycol monomethyl ether acetate

[0131] [Evaluation Method] (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). Two TSKgel SuperMultipore HZ-H columns (manufactured by Tosoh Corporation) were used, tetrahydrofuran was used as the mobile phase, and a differential refractometer was used as the detector. The measurement sample was prepared by dissolving 20 mg of the object to be measured in 2 mL of tetrahydrofuran and 0.5 mL of methanol, and then adding 250 mg of a 0.6 mol / L hexane solution of trimethylsilyldiazomethane. The measurement conditions were a column temperature of 40 °C, a sample injection volume of 10 μL, and a flow rate of 0.35 mL / min. A calibration curve was created using polystyrene (molecular weights 2,110,000, 1,090,000, 706,000, 427,000, 190,000, 96,400, 37,900, 10,200, 2,630, 416) 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.

[0132] (Acid value) The acid value represents the mass of potassium hydroxide required to neutralize the acidic components per 1 g of the solid content. The measurement sample was dissolved in tetrahydrofuran, a few drops of a 1.0 w / v% phenolphthalein ethanol (90) solution were added as an indicator to the resulting solution, and neutralization titration was performed with a potassium hydroxide (0.1 mol / L)-2-propanol solution. The acid value was calculated using the following formula with the point where a slight red color remained as the titration endpoint. A = 56.11 × Vs × 0.1 × f / w A: Acid value (mgKOH / g) Vs: Amount of potassium hydroxide (0.1 mol / L)-2-propanol solution used for titration (mL) f: Titer of potassium hydroxide (0.1 mol / L)-2-propanol solution w: Mass of measurement sample (g) (in terms of solid content)

[0133] (Viscosity of the mixed solution) Using an E-type viscometer (trade name: TVE-22L, manufactured by Toki Sangyo Co., Ltd.), with a cone rotor (0.8° × R24), the viscosity was measured at 25 °C and a rotor rotation speed of 30 rpm.

[0134] (Bubble level of the solution) The bubble level of the solution was determined by visual inspection inside the container as follows. A: Slight bubbles were confirmed at a part of the gas-liquid interface. B: Bubbles were confirmed over the entire gas-liquid interface. C: The entire gas-liquid interface was covered with a large amount of foam like soap bubbles.

[0135] (Gas introduction amount) Using a gas flow meter (KZ-7002-25A manufactured by AS ONE Corporation, or P-530 manufactured by Tokyo Keiso Co., Ltd.), the gas introduction amount per unit area of the interface between the aqueous solution and the gas phase part was calculated.

[0136] (Gas dew point) Using a gas dew point meter (Easidew Online manufactured by MICHELL Instruments), the gas dew point introduced into the aqueous solution was calculated.

[0137] (Amount of solvent distilled off) The mass of the solvent distilled off and recovered by distillation was measured, and the amount of distillation per unit area of the distilled aqueous solution per minute was calculated.

[0138] [Preparation of a mixed solution containing an amphiphilic polymer, a hydrophilic organic solvent, and water] Mixed solution No.1 Into a flask equipped with an argon gas introduction tube and a stirring blade, 104.1 g of BMA, 45.9 g of MAA, 9.0 g of BTEE, 5.5 g of DBDT, 1.0 g of AIBN, 112.5 g of MEK, and 37.5 g of ACN were charged and reacted at 60°C for 17 hours. The polymerization rate was 99%.

[0139] To the reaction solution, a mixed solution of 150.0 g of BzMA, 0.5 g of AIBN, 112.5 g of MEK, and 37.5 g of ACN, which had been previously purged with argon, was added and reacted at 60°C for 22 hours to obtain a reaction solution containing an A-B diblock copolymer. The polymerization rate was 98%.

[0140] To the reaction solution after polymerization, heptane as a hydrophobic organic solvent and MeOH as a hydrophilic organic solvent were added and stirred. After stirring, the mixture was allowed to stand until the hydrophobic organic solvent phase and the hydrophilic organic solvent phase were separated. Then, the hydrophobic organic solvent phase was removed, and the hydrophilic organic solvent phase was recovered. The A-B diblock copolymer was dissolved in the hydrophilic organic solvent phase. The recovered hydrophilic organic solvent phase was subjected to vacuum distillation under the conditions of a temperature of 25°C to 60°C and a pressure of 20 kPa to 40 kPa to obtain a mixed solvent of MeOH, MEK, and ACN and a hydrophilic organic solvent solution No. 1 containing the block copolymer (X). The physical properties of the obtained hydrophilic organic solvent solution No. 1 are shown in Table 1.

[0141] The hydrophilic organic solvent solution No. 1 was placed in a 3-L flask (distillation vessel), and 134.6 g of a 10% by mass aqueous potassium hydroxide solution was added dropwise thereto over 30 minutes while stirring to neutralize a part of the acidic groups in the block copolymer (X) (neutralization rate: 45 mol%). Next, water was added to the flask (distillation vessel) to adjust the volume of the solution to 1.3 L, and the mixture was stirred for 30 minutes to obtain a mixed solution No. 1 containing the amphiphilic polymer, the hydrophilic organic solvent, and water.

[0142] Mixed solution No. 2 A flask equipped with an argon gas inlet tube and a stirring blade was charged with an A1 block component (53.9 g of BMA, 28.6 g of MMA, and 22.1 g of MAA), 9.0 g of BTEE, 5.5 g of DBDT, 1.0 g of AIBN, and 104.7 g of MEK, and the mixture was reacted at 60°C for 18 hours. The polymerization rate was 99%.

[0143] To the reaction solution, a mixed solution of a B block component (90.0 g of BzMA) previously purged with argon, 1.0 g of AIBN, and 90.8 g of MEK was added, and the mixture was reacted at 60°C for 21 hours. The polymerization rate was 99%.

[0144] To the reaction solution, the A2 block components (53.9 g of BMA, 28.6 g of MMA, and 22.1 g of MAA) previously purged with argon, 0.5 g of AIBN, and 74.8 g of MEK were charged, and the mixture was reacted at 60 °C for 21 hours to obtain a reaction solution containing the A1-B-A2 triblock copolymer. The polymerization rate was 99%.

[0145] To the reaction solution after polymerization, heptane as a hydrophobic organic solvent and MeOH as a hydrophilic organic solvent were added and stirred. After stirring, the mixture was allowed to stand until the hydrophobic organic solvent phase and the hydrophilic organic solvent phase were separated, and then the hydrophobic organic solvent phase was removed and the hydrophilic organic solvent phase was recovered. The A1-B-A2 triblock copolymer was dissolved in the hydrophilic organic solvent phase. The recovered hydrophilic organic solvent phase was subjected to vacuum distillation under the conditions of a temperature of 25 °C to 60 °C and a pressure of 20 kPa to 40 kPa to obtain a hydrophilic organic solvent solution No. 2 containing a mixed solvent of MeOH and MEK and the block copolymer (X). The physical properties of the obtained hydrophilic organic solvent solution No. 2 are shown in Table 1.

[0146] The hydrophilic organic solvent solution No. 2 was placed in a 3-L flask (distillation vessel), and 130.0 g of a 10 mass% potassium hydroxide aqueous solution was added dropwise thereto over 30 minutes while stirring to neutralize a part of the acidic groups in the block copolymer (X) (neutralization rate: 45 mol%). Subsequently, water was added to the flask (distillation vessel) to adjust the volume of the solution to 1.3 L, and the mixture was stirred for 30 minutes to obtain a mixed solution No. 2 containing the amphiphilic polymer, the hydrophilic organic solvent, and water.

[0147] Mixed solution No. 3 To a flask equipped with an argon gas inlet tube and a stirring blade, the A block components (75.9 g of BA and 151.9 g of M11EGA), 3.8 g of BTEE, 0.2 g of AIBN, and 57.0 g of PMA were charged, and the mixture was reacted at 60 °C for 12 hours. The polymerization rate was 95%.

[0148] The reaction solution was charged with a B-block component (VP 55.7 g, CHA 16.4 g) previously purged with argon, 0.2 g of AIBN, and 71.6 g of PMA, and reacted at 60 °C for 12 hours to obtain a reaction solution containing an A-B diblock copolymer. The polymerization rate was 97%.

[0149] To the reaction solution after polymerization, heptane as a hydrophobic organic solvent and MeOH as a hydrophilic organic solvent were added and stirred. After stirring, the mixture was allowed to stand until the hydrophobic organic solvent phase and the hydrophilic organic solvent phase were separated, and then the hydrophobic organic solvent phase was removed and the hydrophilic organic solvent phase was recovered. The A-B diblock copolymer was dissolved in the hydrophilic organic solvent phase. The recovered hydrophilic organic solvent phase was subjected to vacuum distillation under the conditions of a temperature of 25 °C to 60 °C and a pressure of 20 kPa to 40 kPa to obtain a hydrophilic organic solvent solution No. 3 containing MeOH and the block copolymer (Y). The physical properties of the obtained hydrophilic organic solvent solution No. 3 are shown in Table 1.

[0150] The hydrophilic organic solvent solution No. 3 was placed in a 3-L flask (distillation vessel), water was added to adjust the volume of the solution to 1.3 L, and the mixture was stirred for 30 minutes to obtain a mixed solution No. 3 containing an amphiphilic polymer, a hydrophilic organic solvent, and water.

[0151]

Table 1

[0152] [Production of amphiphilic polymer aqueous solution] Production Example No. 1 The mixed solution No. 1 was prepared by the method described for the preparation of the mixed solution No. 1. A slight amount of bubbles was confirmed at a part of the gas-liquid interface in the obtained mixed solution No. 1. The surface area of the liquid surface (interface between the gas phase and the liquid phase) of the mixed solution No. 1 was 0.01 m 2 Thereafter. The flask (distillation vessel) containing this mixed solution No. 1 was immersed in an oil bath at 100 °C, and distillation was carried out under atmospheric pressure. However, as the liquid temperature increased, the solution foamed and was covered with foam like soap up to the upper part of the container, making it difficult to distill off the solvent.

[0153] Production Example Nos. 2 to 4 Using the method described for the preparation of the mixed solution No. 1, the mixed solution No. 1 was prepared. The obtained mixed solution No. 1 was in a state where a slight amount of bubbles could be confirmed at a part of the gas-liquid interface. Also, the surface area of the liquid surface (interface between the gas phase and the liquid phase) of the mixed solution No. 1 was 0.01 m 2 was there. The flask (distillation vessel) containing the mixed solution No. 1 was immersed in a water bath, the heating temperature of the mixed solution was adjusted to the temperature described in Table 2, and distillation was carried out while introducing a gas fluid into the gas phase part of the flask (distillation vessel) under atmospheric pressure. By introducing the gas fluid, the discharge of the solvent molecules present in the gas phase part to the outside of the distillation vessel was promoted. The temperature, moisture content, dew point, type, introduction amount (blowing amount) of the gas fluid per unit area of the interface, distillate amount, and foam level of the aqueous solution of the introduced gas fluid are shown in Table 2.

[0154] Production Example No. 5 Using the method described for the preparation of the mixed solution No. 1, the mixed solution No. 1 was prepared. The surface area of the liquid surface (interface between the gas phase and the liquid phase) of the mixed solution No. 1 was 0.01 m 2 was there. Nitrogen gas was blown into the obtained mixed solution No. 1 to form bubbles over the entire gas-liquid interface. The flask (distillation vessel) containing this mixed solution No. 1 was immersed in an oil bath at 100 °C, and distillation was carried out under atmospheric pressure. However, as the liquid temperature rose, the solution foamed and was covered with foam like shaving cream up to the upper part of the container, so it was difficult to distill off the solvent.

[0155] Production Example Nos. 6 to 8 Using the method described for the preparation of the mixed solution No. 1, the mixed solution No. 1 was prepared. The surface area of the liquid surface (interface between the gas phase and the liquid phase) of the mixed solution No. 1 was 0.01 m 2 was there. Nitrogen gas was blown into the obtained mixed solution No. 1 to form bubbles over the entire gas-liquid interface. A flask (distillation vessel) containing the mixed solution No. 1 was immersed in a water bath, and the heating temperature of the mixed solution was adjusted to the temperature described in Table 2. Under atmospheric pressure, distillation was carried out while introducing a gas fluid into the gas phase part of the flask (distillation vessel). By introducing the gas fluid, the discharge of solvent molecules present in the gas phase part to the outside of the distillation vessel was promoted. The temperature, moisture content, dew point, type, introduction amount (blowing amount) of the gas fluid per unit area of the interface, distillate amount, and foam level of the aqueous solution of the introduced gas fluid are shown in Table 2. In addition, for the gas fluids used in Production Examples No. 7 and 8, the gas temperature T2 was adjusted by flowing them through a 50 m copper coil tube heated in an oil bath.

[0156] Production Example No. 9 The mixed solution No. 2 was prepared by the method described for the preparation of the mixed solution No. 2. The obtained mixed solution No. 2 was in a state where a slight amount of foam could be confirmed at a part of the gas-liquid interface. Also, the surface area of the liquid level (interface between the gas phase and the liquid phase) of the mixed solution No. 2 was 0.01 m 2 It was. The flask (distillation vessel) containing this mixed solution No. 2 was immersed in an oil bath at 100 °C, and distillation was carried out under atmospheric pressure. However, as the liquid temperature increased, the solution foamed, and the container was covered with foam like soap up to the upper part, so it was difficult to distill off the solvent.

[0157] Production Examples No. 10 to 14 The mixed solution No. 2 was prepared by the method described for the preparation of the mixed solution No. 2. The obtained mixed solution No. 2 was in a state where a slight amount of foam could be confirmed at a part of the gas-liquid interface. Also, the surface area of the liquid level (interface between the gas phase and the liquid phase) of the mixed solution No. 2 was 0.01 m 2 It was. A flask (distillation vessel) containing the mixed solution No. 2 was immersed in a water bath, and the heating temperature of the mixed solution was adjusted to the temperature described in Table 3. Under atmospheric pressure, distillation was carried out while introducing a gas fluid into the gas phase part of the flask (distillation vessel). By introducing the gas fluid, the discharge of solvent molecules present in the gas phase part to the outside of the distillation vessel was promoted. The temperature, moisture content, dew point, type, introduction amount (blowing amount) of the gas fluid per unit area of the interface, distillate amount, and foam level of the aqueous solution of the introduced gas fluid are shown in Table 3.

[0158] Production Example No. 15 The mixed solution No. 3 was prepared by the method described for the preparation of the mixed solution No. 3. The obtained mixed solution No. 3 was in a state where a slight amount of bubbles could be confirmed at a part of the gas-liquid interface. Also, the surface area of the liquid surface (interface between the gas phase and the liquid phase) of the mixed solution No. 3 was 0.01 m 2 It was. The flask (distillation vessel) containing this mixed solution No. 3 was immersed in an oil bath at 100 °C, and distillation was carried out under atmospheric pressure. However, as the liquid temperature increased, the solution foamed, and the container was covered with soap-like bubbles up to the upper part, so it was difficult to distill off the solvent.

[0159] Production Example No. 16 The mixed solution No. 3 was prepared by the method described for the preparation of the mixed solution No. 3. The obtained mixed solution No. 3 was in a state where a slight amount of bubbles could be confirmed at a part of the gas-liquid interface. Also, the surface area of the liquid surface (interface between the gas phase and the liquid phase) of the mixed solution No. 3 was 0.01 m 2 It was. The flask (distillation vessel) containing the mixed solution No. 3 was immersed in a water bath, the heating temperature of the mixed solution was adjusted to the temperature described in Table 3, and distillation was carried out under atmospheric pressure while introducing a gas fluid into the gas phase part of the flask (distillation vessel). By introducing the gas fluid, the discharge of solvent molecules present in the gas phase part to the outside of the distillation vessel was promoted. The temperature, moisture content, dew point, type of the introduced gas fluid, the introduction amount (blowing amount) of the gas fluid per unit area of the interface, the distillate amount, and the foam level of the aqueous solution are shown in Table 3.

[0160] [Table 2]

[0161] [Table 3]

[0162] In Production Examples No. 1, 5, 9, and 15 where the distillation step was carried out without introducing a gas fluid, as the liquid temperature increased, the solution foamed and was covered with soap-like bubbles up to the upper part of the container, making it difficult to distill off the solvent. On the other hand, in Production Examples No. 2 to 4, 6 to 8, 10 to 14, and 16 where the distillation step was carried out while introducing a gas fluid, foaming was suppressed and the hydrophilic organic solvent could be distilled off.

[0163] The present invention includes the following embodiments. (Embodiment 1) A method for producing an amphiphilic polymer aqueous solution comprising a distillation step of distilling off the hydrophilic organic solvent from a mixed solution containing an amphiphilic polymer, a hydrophilic organic solvent, and water by a distillation method, wherein the boiling point of the hydrophilic organic solvent is less than 100°C, the heating temperature (T1) of the mixed solution in the distillation step is less than 100°C, and in the distillation step, distillation is carried out while introducing a gas fluid into the gas phase part in the system. A method for producing an amphiphilic polymer aqueous solution.

[0164] (Embodiment 2) The method for producing an amphiphilic polymer aqueous solution according to Embodiment 1, wherein the gas fluid is an inert gas or a mixed gas of an inert gas and air.

[0165] (Embodiment 3) The method for producing an amphiphilic polymer aqueous solution according to Embodiment 1 or 2, wherein the heating temperature (T1) of the mixed solution in the distillation step is 50°C or higher and less than 100°C.

[0166] (Embodiment 4) The method for producing an amphiphilic polymer aqueous solution according to any one of Embodiments 1 to 3, wherein the temperature (T2) of the gas fluid in the distillation step is 5°C or higher and less than 100°C.

[0167] (Embodiment 5) The temperature difference (T2 - T1) between the temperature (T2) of the gas fluid in the distillation step and the heating temperature (T1) of the mixed solution is -95°C or higher and 20°C or lower. The method for producing an amphiphilic polymer aqueous solution according to any one of Embodiments 1 to 4.

[0168] (Embodiment 6) The introduction amount of the gas fluid in the distillation step is 0.2 m 3 / (min·m 2 ) or more and 4.0 m 3 / (min·m 2 ) or less. The method for producing an amphiphilic polymer aqueous solution according to any one of Embodiments 1 to 5.

[0169] (Embodiment 7) The water content of the gas fluid in the distillation step is 2.5% by volume or less. The method for producing an amphiphilic polymer aqueous solution according to any one of Embodiments 1 to 6.

[0170] (Embodiment 8) The SP value of the hydrophilic organic solvent is 9.3 (cal / cm 3 ) 1 / 2 or more. The method for producing an amphiphilic polymer aqueous solution according to any one of Embodiments 1 to 7.

[0171] (Embodiment 9) The content of the amphiphilic polymer in the mixed solution is 50 g / L or more and 800 g / L or less. The method for producing an amphiphilic polymer aqueous solution according to any one of Embodiments 1 to 8.

[0172] (Embodiment 10) The amphiphilic polymer has an A block containing a structural unit (a1) derived from a vinyl monomer having an acidic group and a B block containing a structural unit (b1) derived from a hydrophobic vinyl monomer, and is a neutralized product of a block copolymer (X) having an acid value of 20 mgKOH / g or more and 250 mgKOH / g or less, or an A block containing a structural unit (a2) derived from a vinyl monomer having a polyalkylene glycol group and a B block containing a structural unit (b1) derived from a hydrophobic vinyl monomer, and is a block copolymer (Y). The method for producing an aqueous solution of the amphiphilic polymer according to any one of Embodiments 1 to 9.

[0173] (Embodiment 11) The weight average molecular weight (Mw) of the block copolymer (X) is 5,000 or more and 50,000 or less, and the weight average molecular weight (Mw) of the block copolymer (Y) is 5,000 or more and 50,000 or less. The method for producing an aqueous solution of the amphiphilic polymer according to Embodiment 10.

[0174] (Embodiment 12) The molar ratio (A block / B block) of the A block and the B block of the block copolymer (X) is 0.5 or more and 5.0 or less, and the molar ratio (A block / B block) of the A block and the B block of the block copolymer (Y) is 0.5 or more and 5.0 or less. The method for producing an aqueous solution of the amphiphilic polymer according to Embodiment 10 or 11.

[0175] (Embodiment 13) The structural unit (a1) derived from the vinyl monomer having an acidic group is a structural unit derived from a (meth)acrylic monomer having an acidic group. The method for producing an aqueous solution of the amphiphilic polymer according to any one of Embodiments 10 to 12.

[0176] (Embodiment 14) The structural unit (b1) derived from the hydrophobic vinyl monomer is a structural unit derived from at least one vinyl monomer selected from the group consisting of (meth)acrylate having a chain alkyl group, (meth)acrylate having a cyclic alkyl group, (meth)acrylate having an aryl group, (meth)acrylate having a hydroxyalkyl group, (meth)acrylate having a lactone-modified hydroxy group, (meth)acrylate having an alkoxyalkyl group, (meth)acrylate having an oxygen-containing heterocyclic group, (meth)acrylamides, styrene-based monomers, and vinyl monomers having a nitrogen-containing heterocyclic group. The method for producing an amphiphilic polymer aqueous solution according to any one of Embodiments 10 to 13.

[0177] (Embodiment 15) The structural unit (a2) derived from the vinyl monomer having a polyalkylene glycol structure is a structural unit derived from at least one vinyl monomer selected from the group consisting of (meth)acrylate having a terminal hydroxy group polyalkylene glycol group and (meth)acrylate having an alkoxy polyalkylene glycol group. The method for producing an amphiphilic polymer aqueous solution according to any one of Embodiments 10 to 15.

[0178] (Embodiment 16) The block copolymer (X) is obtained by living polymerization, and its molecular weight distribution (Mw / Mn) is 3.0 or less. The block copolymer (Y) is obtained by living polymerization, and its molecular weight distribution (Mw / Mn) is 3.0 or less. The method for producing an amphiphilic polymer aqueous solution according to any one of Embodiments 10 to 15.

Explanation of Reference Numerals

[0179] 1: Distillation vessel, 2: Heating device, 3: Discharge path, 4: Introduction path, 5: Stirring member, 6: Mixed solution, 10: Liquid phase part, 20: Gas phase part

Claims

1. A method for producing an amphiphilic polymer aqueous solution, comprising a distillation step of distilling off a hydrophilic organic solvent from a mixed solution containing an amphiphilic polymer, a hydrophilic organic solvent, and water, comprising: The boiling point of the hydrophilic organic solvent is less than 100° C., The heating temperature (T1) of the mixed solution in the distillation step is less than 100° C., A method for producing an aqueous amphiphilic polymer solution, wherein the distillation is carried out while introducing a gas fluid into a gas phase portion of the system in the distillation step.

2. The method for producing an amphiphilic polymer aqueous solution according to claim 1, wherein the gas fluid is an inert gas or a mixed gas of an inert gas and air.

3. The method for producing an amphiphilic polymer aqueous solution according to claim 1 or 2, wherein the heating temperature (T1) of the mixed solution in the distillation step is 50°C or higher and lower than 100°C.

4. The method for producing an amphiphilic polymer aqueous solution according to claim 1 or 2, wherein the temperature (T2) of the gas fluid in the distillation step is 5°C or higher and lower than 100°C.

5. The method for producing an amphiphilic polymer aqueous solution according to claim 1 or 2, wherein a temperature difference (T2-T1) between the temperature (T2) of the gas fluid in the distillation step and the heating temperature (T1) of the mixed solution is -95°C or more and 20°C or less.

6. The amount of gas fluid introduced in the distillation step is 0.2 m per unit area of ​​the interface between the mixed solution and the gas phase. 3 / (min.m 2 ) or more, 4.0m 3 / (min.m 2 3. The method for producing an amphiphilic polymer aqueous solution according to claim 1 or 2, wherein the aqueous solution is 0.1 to 1.0 wt %.

7. The method for producing an amphiphilic polymer aqueous solution according to claim 1 or 2, wherein the water content of the gas fluid in the distillation step is 2.5 vol % or less.

8. The SP value of the hydrophilic organic solvent is 9.3 (cal / cm 3 ) 1 / 2 The method for producing an aqueous amphiphilic polymer solution according to claim 1 or 2, which is as described above.

9. 3. The method for producing an amphiphilic polymer aqueous solution according to claim 1, wherein the content of the amphiphilic polymer in the mixed solution is 50 g / L or more and 800 g / L or less.

10. 3. The method for producing an amphiphilic polymer aqueous solution according to claim 1 or 2, wherein the amphiphilic polymer is a neutralized product of block copolymer (X) having an A block containing a structural unit (a1) derived from a vinyl monomer having an acidic group and a B block containing a structural unit (b1) derived from a hydrophobic vinyl monomer, and having an acid value of 20 mg KOH / g or more and 250 mg KOH / g or less, or a block copolymer (Y) having an A block containing a structural unit (a2) derived from a vinyl monomer having a polyalkylene glycol group and a B block containing a structural unit (b1) derived from a hydrophobic vinyl monomer.

11. The method for producing an amphiphilic polymer aqueous solution according to claim 10, wherein the weight average molecular weight (Mw) of the block copolymer (X) is 5,000 or more and 50,000 or less, and the weight average molecular weight (Mw) of the block copolymer (Y) is 5,000 or more and 50,000 or less.

12. The method for producing an amphiphilic polymer aqueous solution according to claim 10, wherein the molar ratio of the A block to the B block (A block / B block) of the block copolymer (X) is 0.5 or more and 5.0 or less, and the molar ratio of the A block to the B block (A block / B block) of the block copolymer (Y) is 0.5 or more and 5.0 or less.

13. The method for producing an amphiphilic polymer aqueous solution according to claim 10, wherein the structural unit (a1) derived from a vinyl monomer having an acidic group is a structural unit derived from a (meth)acrylic monomer having an acidic group.

14. The structural unit (b1) derived from the hydrophobic vinyl monomer is a structural unit derived from at least one vinyl monomer selected from the group consisting of (meth)acrylates having a chain alkyl group, (meth)acrylates having a cyclic alkyl group, (meth)acrylates having an aryl group, (meth)acrylates having a hydroxyalkyl group, (meth)acrylates having a lactone-modified hydroxy group, (meth)acrylates having an alkoxyalkyl group, (meth)acrylates having an oxygen-containing heterocyclic group, (meth)acrylamides, styrene-based monomers, and vinyl monomers having a nitrogen-containing heterocyclic group. The method for producing an amphiphilic polymer aqueous solution according to claim 10.

15. The method for producing an amphiphilic polymer aqueous solution according to claim 10, wherein the structural unit (a2) derived from a vinyl monomer having a polyalkylene glycol structure is a structural unit derived from at least one vinyl monomer selected from the group consisting of (meth)acrylates having a terminal hydroxyl group-containing polyalkylene glycol group and (meth)acrylates having an alkoxypolyalkylene glycol group.

16. The method for producing an amphiphilic polymer aqueous solution according to claim 10, wherein the block copolymer (X) is obtained by living polymerization and has a molecular weight distribution (Mw / Mn) of 3.0 or less, and the block copolymer (Y) is obtained by living polymerization and has a molecular weight distribution (Mw / Mn) of 3.0 or less.

Images