JP2005264012A - Manufacturing process of acrylic block copolymer particle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process by which an acrylic block copolymer particle having a low melting viscosity and a strong tackiness is easily and inexpensively manufactured. <P>SOLUTION: The manufacturing process of the acrylic block copolymer particle comprises dropping a poor solvent having an SP value (solubility parameter) of ≤16.9 or ≥21.1 into the solution of the acrylic block copolymer under agitation with an agitation power of ≥0.1 kW/m<SP>3</SP>. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing acrylic block copolymer particles.

  The method for producing the particulate polymer is a method in which the polymerization method of the polymer is emulsion polymerization or suspension polymerization, and the polymer is particulated at the time of polymerization. After the polymerization, the polymer solution is flash-evaporated to form polymer particles. There are a method of obtaining, a method of melting a solid polymer into particles, a method of mechanically crushing a solid polymer into particles, and the like. In general, since a polymer is often used after being compounded with other polymers, inorganic substances, pigments and the like, a particle production method by melt extrusion is particularly widely used.

  However, in the method for producing particles by melting a solid polymer, it is extremely difficult to make the molten polymer into particles when the polymer has a low melt viscosity and a strong surface tack property. In general, when a polymer having such properties is made into particles, an underwater cutting technique is known in which the melt-extruded polymer is cut in water. There are many technical problems such as clogging, and the productivity is low, so the manufacturing cost is high, and there are very few examples of use when operating on a practical scale. As a prior art regarding an underwater cutting technique, there exists Unexamined-Japanese-Patent No. 2002-166417 (patent document 1), for example. As a method for producing polymer particles having such physical properties, a method of freeze pulverization is known. However, this method is expensive and is not suitable for producing general-purpose polymer particles. As a prior art regarding freeze pulverization, there is, for example, Japanese Patent No. 5-005050 (Patent Document 2).

  Therefore, in order to produce particles of an acrylic block copolymer having a low melt viscosity and a strong surface tack property as used in the present invention, it is necessary to establish a new particle production method. Accordingly, the present inventors have noted that an acrylic block copolymer reprecipitated using a specific solvent can be easily pulverized into particles by mechanical stirring. It came to invention of a manufacturing method.

Japanese Patent Laid-Open No. 11-209422 (Patent Document 3) is known as a prior art regarding a reprecipitation method of an acrylic polymer. This publication uses reprecipitation to remove some amount of skin irritating compounds contained in the acrylic polymer, and reprecipitation for producing the acrylic block copolymer particles described in the present invention. Is significantly different from the purpose and application.
JP 2002-166417 A Japanese Patent No. 5-005050 Patent Hei 11-209422

  Provided is a method for easily and inexpensively producing particles of an acrylic block copolymer having a low melt viscosity and a strong surface tack property. In particular, an object of the present invention is to provide a method for producing particles having an average diameter of 0.01 to 3.00 mm in a simple and inexpensive manner in a method for producing particles of an acrylic block copolymer.

In order to solve the above-mentioned problems, the present inventors have intensively studied, and as a result, completed the present invention. That is, the present invention relates to an acrylic block copolymer solution with an SP value (solubility of 16.9 or less, or 21.1 or more while applying a stirring force of 0.1 kW / m ³ or more to the polymer solution. It is related with the manufacturing method of the acrylic block copolymer particle | grains characterized by being obtained by dripping the poor solvent which has a parameter).

  As a preferred embodiment, the present invention relates to a method for producing acrylic block copolymer particles, wherein the average particle size corresponding to a sphere is 0.01 to 3.00 mm.

  As a preferred embodiment, the present invention relates to a method for producing acrylic block copolymer particles, wherein the SP value of the solvent of the acrylic block copolymer solution is 17.0 to 21.0.

  As a preferred embodiment, the acrylic block copolymer solution is a solution containing 25 to 50% by weight of the acrylic block copolymer, and the poor solvent is 100 to 300 parts by weight with respect to 100 parts by weight of the polymer solution. The present invention relates to a method for producing acrylic block copolymer particles.

  As a preferred embodiment, the present invention relates to a method for producing acrylic block copolymer particles, wherein a poor solvent is dropped into a polymer solution in 5 to 30 minutes.

  As a preferred embodiment, the present invention relates to a method for producing acrylic block copolymer particles, wherein the poor solvent is methanol, hexane, heptane, octane or decane.

  As a preferred embodiment, the present invention relates to a method for producing acrylic block copolymer particles, wherein the solvent of the acrylic block copolymer solution is at least one member of the group consisting of acetone, toluene and ethyl acetate.

  As a preferred embodiment, after the acrylic block copolymer particles are precipitated, 0.1 to 10 parts by weight of an inorganic compound is added to 100 parts by weight of the acrylic block polymer. The present invention relates to a method for producing polymer particles.

  As a preferred embodiment, the present invention relates to a method for producing acrylic block copolymer particles, wherein the inorganic compound is talc or calcium carbonate.

  As a preferred embodiment, the present invention relates to a method for producing acrylic block copolymer particles, wherein the acrylic block copolymer comprises an acrylic polymer block (a) and a methacrylic polymer block (b). .

  As a preferred embodiment, the present invention relates to a method for producing acrylic block copolymer particles, wherein the acrylic block copolymer is produced by atom transfer radical polymerization.

  Acrylic block copolymer particles having a low melt viscosity and a strong surface tackiness can be produced easily and inexpensively.

  By reprecipitation purification, the acrylic block copolymer has excellent heat resistance and mechanical properties by avoiding deterioration of mechanical properties due to thermal decomposition of the acrylic block copolymer and removing impurities in the acrylic block copolymer. A copolymer is obtained.

  After precipitation, particles are formed by mechanical stirring in water, so that there is almost no aggregation of particles, and the particle diameter can be arbitrarily adjusted by stirring force.

  The solvent and the poor solvent can be recycled by distillation after collection by filtration, and the cost of raw materials can be reduced.

  Hereinafter, the present invention will be described in more detail.

<Acrylic block copolymer (A)>
The structure of the acrylic block copolymer (A) may be a linear block copolymer, a branched (star) block copolymer, or a mixture thereof. The structure of the acrylic block copolymer (A) may be used depending on the required physical properties of the acrylic block copolymer (A), but from the viewpoint of cost and ease of polymerization, it is linear. A block copolymer is preferred.

The linear block copolymer may be of any linear block structure, but it constitutes the acrylic block copolymer (A) from the viewpoint of its physical properties or physical properties when made into a composition. Acrylic polymer block (a) (hereinafter also referred to as polymer block (a) or block (a)) and methacrylic polymer block (b) (hereinafter referred to as polymer block (b) or block ( b)), when the acrylic polymer block (a) is represented as a and the methacrylic polymer block (b) as b, the general formula: (ab) _n , the general formula: b- (a-b) _n, the general formula: (the n 1 to 3 of an integer) (a-b) _n -a is at least one block copolymer selected from the group consisting of a block copolymer represented by It is preferable. Among these, an ab type diblock copolymer, a bab type triblock copolymer, or a mixture thereof from the viewpoint of easy handling during processing and physical properties in the case of a composition. Is preferred.

  The number average molecular weight of the acrylic block copolymer (A) is not particularly limited, but is preferably 30,000 to 500,000, more preferably 50,000 to 400,000. When the number average molecular weight is small, the viscosity is low, and when the number average molecular weight is large, the viscosity tends to be high. Therefore, the viscosity is set according to required processing characteristics.

  The ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by gel permeation chromatography of the block copolymer is not particularly limited, but is preferably 1.8 or less, more preferably 1.5 or less. When Mw / Mn exceeds 1.8, the uniformity of the block copolymer may be lowered.

  The composition ratio of the acrylic block copolymer (A) to the acrylic polymer block (b) and the acrylic polymer block (a) is 5 to 90% by weight of the acrylic polymer block (b), acrylic. The polymer block (a) is 95 to 10% by weight. From the viewpoint of maintaining the shape at the time of molding and elasticity as an elastomer, the preferred range of the composition ratio is 10 to 80% by weight for the methacrylic polymer block (b) and 90 to 20 for the acrylic polymer block (a). More preferably, the methacrylic polymer block (b) is 20 to 50% by weight and the acrylic polymer block (a) is 80 to 50% by weight. If the proportion of the methacrylic polymer block (b) is less than 5% by weight, the shape may be difficult to be maintained during molding, and if the proportion of the acrylic polymer block (a) is less than 10% by weight, the elasticity as an elastomer. May decrease.

  From the viewpoint of the hardness of the elastomer composition, when the proportion of the methacrylic polymer block (b) is small, the hardness is low, and when the proportion of the methacrylic polymer block (b) is large, the hardness tends to be high. Therefore, it can be set according to the required hardness of the elastomer composition. From the viewpoint of processing, the viscosity is low when the proportion of the methacrylic polymer block (b) is small, and the viscosity tends to be high when the proportion of the methacrylic polymer block (b) is large. It can be set according to the required processing characteristics.

<Acrylic polymer block (a)>
The acrylic polymer block (a) is a block obtained by polymerizing a monomer having an acrylic ester as a main component, and includes 50 to 100% by weight of the acrylic ester and a vinyl monomer copolymerizable therewith. It is preferably composed of 0 to 50% by weight.

  Examples of the acrylic acid ester constituting the acrylic polymer block (a) include methyl acrylate, ethyl acrylate, acrylic acid-n-propyl, acrylic acid isopropyl, acrylic acid-n-butyl, acrylic acid isobutyl, acrylic Acid-t-butyl, acrylate-n-pentyl, acrylate-n-hexyl, cyclohexyl acrylate, acrylate-n-heptyl, acrylate-n-octyl, acrylate-2-ethylhexyl, nonyl acrylate, acrylic Decyl acid, dodecyl acrylate, phenyl acrylate, toluyl acrylate, benzyl acrylate, isobornyl acrylate, 2-methoxyethyl acrylate, 3-methoxybutyl acrylate, 2-hydroxyethyl acrylate, acrylic acid 2-hydroxypropi , Stearyl acrylate, glycidyl acrylate, 2-aminoethyl acrylate, ethylene oxide adduct of acrylic acid, trifluoromethyl methyl acrylate, 2-trifluoromethyl ethyl acrylate, 2-perfluoroethyl acrylate Ethyl, 2-perfluoroethyl-2-perfluoroethyl acrylate, 2-perfluoroethyl acrylate, perfluoromethyl acrylate, diperfluoromethyl methyl acrylate, 2-perfluoromethyl-2 acrylate -Perfluoroethylmethyl, 2-perfluorohexylethyl acrylate, 2-perfluorodecylethyl acrylate, 2-perfluorohexadecylethyl acrylate, and the like.

  At least one of these can be used. Among these, acrylic acid-n-butyl is preferable from the viewpoint of rubber elasticity, low temperature characteristics and cost balance. Further, when low temperature characteristics, mechanical characteristics, and compression set are required, 2-ethylhexyl acrylate may be copolymerized. If oil resistance and mechanical properties are required, ethyl acrylate is preferred. Further, when it is necessary to impart low temperature characteristics and oil resistance and to improve the surface tackiness of the resin, 2-methoxyethyl acrylate is preferable. And in order to raise heat resistance, acrylic acid-t-butyl is preferable as a precursor at the time of introducing an acid anhydride group. When a balance between oil resistance and low-temperature characteristics is required, a combination of ethyl acrylate, acrylic acid-n-butyl and acrylic acid-2-methoxyethyl is preferred.

  Examples of vinyl monomers copolymerizable with the acrylic ester constituting the acrylic polymer block (a) include methacrylic esters, aromatic alkenyl compounds, vinyl cyanide compounds, conjugated diene compounds, halogens, and the like. Examples thereof include an unsaturated compound containing silicon, an unsaturated compound containing silicon, an unsaturated dicarboxylic acid compound, a vinyl ester compound, and a maleimide compound.

  Examples of the methacrylic acid ester include methyl methacrylate, ethyl methacrylate, methacrylic acid-n-propyl, isopropyl methacrylate, methacrylic acid-n-butyl, methacrylic acid isobutyl, methacrylic acid, Methacrylate-n-pentyl, methacrylate-n-hexyl, cyclohexyl methacrylate, methacrylate-n-heptyl, methacrylate-n-octyl, methacrylate-2-ethylhexyl, nonyl methacrylate, Decyl methacrylate, dodecyl methacrylate, phenyl methacrylate, toluyl methacrylate, benzyl methacrylate, isobornyl methacrylate, 2-methoxyethyl methacrylate, 3-methoxybutyl methacrylate, methacryl Acid-2-hydride Xylethyl, 2-hydroxypropyl methacrylate, stearyl methacrylate, glycidyl methacrylate, 2-aminoethyl methacrylate, γ- (methacryloyloxypropyl) trimethoxysilane, γ- (methacryloyloxypropyl) dimethoxymethyl Silane, methacrylic acid ethylene oxide adduct, trifluoromethyl methyl methacrylate, methacrylic acid-2-trifluoromethylethyl, methacrylic acid-2-perfluoroethyl ethyl, methacrylic acid 2-perfluoroethyl- 2-perfluorobutylethyl, 2-perfluoroethyl methacrylate, perfluoromethyl methacrylate, diperfluoromethyl methyl methacrylate, 2-perfluoromethyl-2-perfluoro methacrylate Ethyl methyl methacrylic acid-2-perfluorohexylethyl, methacrylic acid-2-perfluorodecyl ethyl, and the like methacrylic acid-2-perfluoroalkyl-hexadecyl ethyl.

  Examples of the aromatic alkenyl compound include styrene, α-methylstyrene, p-methylstyrene, p-methoxystyrene, and the like. Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile. Examples of the conjugated diene compound include butadiene and isoprene. Examples of the halogen-containing unsaturated compound include vinyl chloride, vinylidene chloride, perfluoroethylene, perfluoropropylene, and vinylidene fluoride. Examples of the silicon-containing unsaturated compound include vinyltrimethoxysilane and vinyltriethoxysilane. Examples of the unsaturated dicarboxylic acid compound include maleic anhydride, maleic acid, monoalkyl esters and dialkyl esters of maleic acid, fumaric acid, monoalkyl esters and dialkyl esters of fumaric acid, and the like. Examples of the vinyl ester compound include vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, vinyl cinnamate, and the like. Examples of the maleimide compound include maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, cyclohexylmaleimide and the like.

  At least one of these can be used. These vinyl monomers are preferable from the viewpoint of balance such as glass transition temperature and oil resistance required for the acrylic polymer block (a) and compatibility with the methacrylic polymer block (b). You can choose one.

  From the viewpoint of rubber elasticity of the elastomer composition, the glass transition temperature of the acrylic polymer block (a) is preferably 25 ° C. or lower, more preferably 0 ° C. or lower, and further preferably −20 ° C. or lower. If the glass transition temperature of the acrylic polymer block (a) is higher than 25 ° C, rubber elasticity may not be exhibited, which is disadvantageous.

<Methacrylic polymer block (b)>
The methacrylic polymer block (b) is a block obtained by polymerizing a monomer having a methacrylic acid ester as a main component. The methacrylic acid ester is 50 to 100% by weight and a vinyl copolymer copolymerizable therewith. It is preferably composed of 0 to 50% by weight of monomer.

  Examples of the methacrylic acid ester constituting the methacrylic polymer block (b) include those exemplified previously as vinyl monomers copolymerizable with the acrylate ester constituting the acrylic polymer block (a). And the same monomers as the methacrylic acid ester.

  At least one of these can be used. Among these, methyl methacrylate is preferable in terms of processability, cost, and availability. Further, the glass transition point can be increased by copolymerizing isobornyl methacrylate and cyclohexyl methacrylate. Furthermore, in order to raise heat resistance, methacrylic acid-t-butyl is preferable as a precursor at the time of introducing an acid anhydride.

  Examples of the vinyl monomer copolymerizable with the methacrylic acid ester constituting the methacrylic polymer block (b) include acrylic acid esters, aromatic alkenyl compounds, conjugated diene compounds, and halogen-containing unsaturated compounds. And silicon-containing unsaturated compounds, unsaturated dicarboxylic acid compounds, vinyl ester compounds, maleimide compounds, and the like.

  As an acrylic ester, the monomer similar to the acrylic ester illustrated previously as an acrylic ester which comprises an acrylic polymer block (a) is mentioned, for example.

  Aromatic alkenyl compounds, vinyl cyanide compounds, conjugated diene compounds, halogen-containing unsaturated compounds, silicon-containing unsaturated compounds, unsaturated dicarboxylic acid compounds, vinyl ester compounds, and maleimide compounds include acrylic polymer blocks (a The monomer similar to what was illustrated as a monomer which comprises) can be mention | raise | lifted.

  At least one of these can be used. These vinyl monomers are selected from the viewpoints of adjusting the glass transition temperature required for the methacrylic polymer block (b) and compatibility with the acrylic polymer block (a). be able to.

  The glass transition temperature of the methacrylic polymer block (b) is preferably 25 ° C. or higher, more preferably 40 ° C. or higher, and further preferably 50 ° C. or higher, from the viewpoint of thermal deformation of the elastomer composition. If the glass transition temperature of the methacrylic polymer block (b) is lower than 25 ° C., thermal deformation may be likely due to a decrease in cohesive force.

<Method for Producing Acrylic Block Copolymer (A)>
As a polymerization method of the acrylic block copolymer (A), it is preferable to use controlled polymerization. Examples of controlled polymerization include living anionic polymerization, radical polymerization using a chain transfer agent, and recently developed living radical polymerization. Living radical polymerization is preferable from the viewpoint of controlling the molecular weight and structure of the block copolymer and copolymerizing a monomer having a crosslinkable functional group.

  Living polymerisation, in the narrow sense, indicates that the terminal always has activity, but generally also includes pseudo-living polymerization where the terminal is inactive and the terminal is in equilibrium. The living radical polymerization in the present invention is a radical polymerization in which the polymerization terminal is activated and deactivated is maintained in an equilibrium state, and has been actively studied in various groups in recent years. .

  Examples thereof include those using a chain transfer agent such as polysulfide, those using a radical scavenger such as a cobalt porphyrin complex (Journal of American Chemical Society, 1994, 116, 7943) or a nitroxide compound (Macromolecules, 1994, 27, 7228). ), Atom transfer radical polymerization (ATRP) using an organic halide as an initiator and a transition metal complex as a catalyst. In the present invention, there is no particular limitation as to which of these methods is used, but atom transfer radical polymerization is preferred from the viewpoint of ease of control.

  In the atom transfer radical polymerization, an organic halide or a sulfonyl halide compound is used as an initiator, and a metal complex having a group metal of group 8, 9, 10, or 11 as a central metal in the periodic table is used as a catalyst ( For example, Matyjaszewski et al., Journal of American Chemical Society, 1995, 117, 5614, Macromolecules, 1995, 28, 7901, Science, 1996, 272, 866, or Sawamoto et al., Ul17).

  According to these methods, in general, the polymerization rate is very high, and the radical polymerization is likely to cause a termination reaction such as coupling between radicals, but the polymerization proceeds in a living manner and Mw / Mn = 1 having a narrow molecular weight distribution. A polymer having a molecular weight of about 1 to 1.5 is obtained, and the molecular weight can be freely controlled by the ratio of the monomer and the initiator when charged.

  In the atom transfer radical polymerization method, a monofunctional, difunctional, or polyfunctional compound can be used as the organic halide or sulfonyl halide compound used as an initiator. These can be used properly according to the purpose. When producing a diblock copolymer, a monofunctional compound is preferable. When polymerizing an aba type triblock copolymer or a babb type triblock copolymer, it is preferable to use a bifunctional compound. When polymerizing a branched block copolymer, it is preferable to use a polyfunctional compound.

Examples of the monofunctional compound include compounds represented by the following chemical formulas.
C ₆ H ₅ —CH ₂ X
C ₆ H ₅ -CHX-CH _{3
C 6 H 5 -C (CH 3} ) 2 X
R ¹ —CHX—COOR ^{2
_{R 1 -C (CH 3) X}} -COOR 2
R ¹ —CHX—CO—R ²
R ¹ —C (CH ₃ ) X—CO—R ²
R ¹ —C ₆ H ₄ —SO ₂ X
In the formula, C ₆ H ₄ represents a phenylene group. The phenylene group may be any of ortho substitution, meta substitution and para substitution. R ¹ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms. X represents chlorine, bromine or iodine. R ² represents a monovalent organic group having 1 to 20 carbon atoms.

Examples of the bifunctional compound include compounds represented by the following chemical formulas.
X—CH ₂ —C ₆ H ₄ —CH ₂ —X
_{X-CH (CH 3) -C} 6 H 4 -CH (CH 3) -X
_{X-C (CH 3) 2} -C 6 H 4 -C (CH 3) 2 -X
X—CH (COOR ³ ) — (CH ₂ ) _n —CH (COOR ³ ) —X
_{X-C (CH 3) (} COOR 3) - (CH 2) n -C (CH 3) (COOR 3) -X
X—CH (COR ³ ) — (CH ₂ ) _n —CH (COR ³ ) —X
_{X-C (CH 3) (} COR 3) - (CH 2) n -C (CH 3) (COR 3) -X
_{X-CH 2 -CO-CH 2} -X
_{X-CH (CH 3) -CO} -CH (CH 3) -X
_{X-C (CH 3) 2} -CO-C (CH 3) 2 X
_{X-CH (C 6 H 5} ) -CO-CH (C 6 H 5) -X
X—CH ₂ —COO— (CH ₂ ) _n —OCO—CH ₂ —X
_{X-CH (CH 3) -COO-} (CH 2) n -OCO-CH (CH 3) -X
_{X-C (CH 3) 2} -COO- (CH 2) n -OCO-C (CH 3) 2 -X
_{X-CH 2 -CO-CO-} CH 2 -X
_{X-CH (CH 3) -CO} -CO-CH (CH 3) -X
_{X-C (CH 3) 2} -CO-CO-C (CH 3) 2 -X
X—CH ₂ —COO—C ₆ H ₄ —OCO—CH ₂ —X
X—CH (CH ₃ ) —COO—C ₆ H ₄ —OCO—CH (CH ₃ ) —X
_{X-C (CH 3) 2} -COO-C 6 H 4 -OCO-C (CH 3) 2 -X
_{X-SO 2 -C 6 H 4} -SO 2 -X
In the formula, R ³ represents an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms. C ₆ H ₄ represents a phenylene group. The phenylene group may be any of ortho substitution, meta substitution and para substitution. C ₆ H ₅ represents a phenyl group. n represents an integer of 0 to 20. X represents chlorine, bromine or iodine.

Examples of the polyfunctional compound include compounds represented by the following chemical formulas.
C ₆ H ₃ (CH ₂ X) _{3
C 6 H 3 (CH (CH} 3) -X) 3
_{C 6 H 3 (C (CH} 3) 2 -X) 3
_{C 6 H 3 (OCO-CH} 2 X) 3
_{C 6 H 3 (OCO-CH} (CH 3) -X) 3
_{C 6 H 3 (OCO-C} (CH 3) 2 -X) 3
C ₆ H ₃ (SO ₂ X) ₃
In the formula, C ₆ H ₃ represents a trisubstituted phenyl group. In the trisubstituted phenyl group, the position of the substituent may be any of 1-position to 6-position. X represents chlorine, bromine or iodine.

  In these organic halides or sulfonyl halide compounds that can be used as initiators, the carbon to which the halogen is bonded is bonded to the carbonyl group, phenyl group, etc., and the carbon-halogen bond is activated to initiate polymerization. To do. The amount of the initiator to be used may be determined from the ratio with the monomer in accordance with the required molecular weight of the block copolymer. That is, the molecular weight of the block copolymer can be controlled by the number of monomers used per molecule of the initiator.

  The transition metal complex used as the catalyst for the atom transfer radical polymerization is not particularly limited, but preferred is a monovalent and zerovalent copper, divalent ruthenium, divalent iron or divalent nickel complex. I can give you. Among these, a copper complex is preferable from the viewpoint of cost and reaction control.

Examples of the monovalent copper compound include cuprous chloride, cuprous bromide, cuprous iodide, cuprous cyanide, cuprous oxide, cuprous perchlorate, and the like. . When a copper compound is used, 2,2′-bipyridyl and its derivatives, 1,10-phenanthroline and its derivatives, tetramethylethylenediamine (TMEDA), pentamethyldiethylenetriamine, hexamethyl (2-aminoethyl) Polyamines such as amines can also be added as ligands. A tristriphenylphosphine complex of divalent ruthenium chloride (RuCl ₂ (PPh ₃ ) ₃ ) can also be used as a catalyst.

When a ruthenium compound is used as a catalyst, aluminum alkoxides can also be added as an activator. Further, a divalent iron bistriphenylphosphine complex (FeCl ₂ (PPh ₃ ) ₂ ), a divalent nickel bistriphenylphosphine complex (NiCl ₂ (PPh ₃ ) ₂ ), and a divalent nickel bistributylphosphine A complex (NiBr ₂ (PBu ₃ ) ₂ ) can also be used as a catalyst. The amount of catalyst, ligand and activator used is not particularly limited, but will vary depending on the amount of initiator, monomer and solvent used. It is possible to carry out the reaction under control.

  The atom transfer radical polymerization can be carried out without solvent (bulk polymerization) or in various solvents. Examples of the solvent include hydrocarbon solvents such as benzene and toluene, halogenated hydrocarbon solvents such as methylene chloride and chloroform, ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, methanol, ethanol, propanol, and isopropanol. Alcohol solvents such as n-butanol and t-butanol, nitrile solvents such as acetonitrile, propionitrile and benzonitrile, ester solvents such as ethyl acetate and butyl acetate, carbonate solvents such as ethylene carbonate and propylene carbonate, etc. These can be used by mixing at least one of them. In this case, the polymerization reaction can be arbitrarily controlled by appropriately determining the solvent species and the solvent amount. Moreover, when using a solvent, the usage-amount can be suitably determined from the relationship between the viscosity of the whole system, and the required stirring efficiency.

  In the atom transfer radical polymerization, it is extremely important to avoid the mixing of oxygen that causes a decrease in the activity of the polymerization catalyst from the preparation of the polymerization to the end of the polymerization. When oxygen is mixed, the polymerization activity is remarkably lowered. Therefore, it is necessary to appropriately add a catalyst and a ligand to increase the catalyst activity. However, excessive addition of a catalyst and a ligand not only complicates the catalyst removal step after the completion of the polymerization reaction, but also significantly reduces the living polymerizability. Combined blocks increase the molecular weight distribution and reduce the quality of the product. Therefore, it is preferable in terms of product quality and cost to perform atom transfer radical polymerization by sufficiently substituting the production raw material and the reactor with nitrogen in advance.

  The atom transfer radical polymerization can be carried out in the range of preferably 25 ° C to 200 ° C, more preferably 50 to 150 ° C. If the atom transfer radical polymerization temperature is lower than 25 ° C, the viscosity may be too high and the reaction rate may be slow, and if it exceeds 200 ° C, an inexpensive polymerization solvent may not be used.

  As a method of polymerizing a block copolymer by the atom transfer radical polymerization, a method of sequentially adding monomers, a method of polymerizing the next block using a polymer synthesized in advance as a polymer initiator, and polymerizing separately Examples thereof include a method of bonding a polymer by reaction. These methods can be used properly according to the purpose. From the viewpoint of simplicity of the polymerization step, a method by sequential monomer addition is preferred.

  The reaction solution obtained by polymerization contains a mixture of a polymer and a metal complex. For example, an organic acid can be added to remove the metal complex. Subsequently, an acrylic block copolymer resin solution containing the acrylic block copolymer can be obtained by removing impurities by adsorption treatment. The organic acid that can be used in the present invention is not particularly limited, but is preferably an organic substance containing a carboxylic acid group or a sulfonic acid group.

  The organic carboxylic acid that can be used in the present invention, that is, an organic substance containing a carboxylic acid group is not particularly limited. For example, formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, hexane Monofunctional saturated aliphatic monofunctional carboxylic acids such as acid, 4-methylvaleric acid, heptanoic acid, undecanoic acid, and icosanoic acid, and saturated aliphatic monofunctional containing halogen such as monochloroacetic acid, dichloroacetic acid, and trichloroacetic acid Monofunctional saturated aliphatic compounds containing substituents such as carboxylic acid, acetoxysuccinic acid, acetoacetic acid, ethoxyacetic acid, 4-oxovaleric acid, glycolic acid, glycidic acid, glyceric acid, 2-oxobutyric acid, glutaric acid Carboxylic acid, propiolic acid, acrylic acid, crotonic acid, 4-pentenoic acid, allylmalonic acid, itaconic acid, oxalo Aliphatic unsaturated monofunctional carboxylic acid such as acid, benzoic acid, acetylbenzoic acid, acetylsalicylic acid, atropaic acid, anisic acid, cinnamic acid, salicylic acid, etc. Carboxylic acid at α-position of unsaturated ring or unsaturated bond Saturated monofunctional carboxylic acid, oxalic acid, malonic acid, succinic acid, adipic acid, 3-oxoglutaric acid, azelaic acid, ethylmalonic acid, 4-oxoheptane diacid, 3-oxoglutaric acid, etc. Aliphatic difunctional carboxylic acids, unsaturated aliphatic difunctional carboxylic acids such as acetylenedicarboxylic acid, aromatic difunctional carboxylic acids such as isophthalic acid, tricarboxylic acids such as anicotic acid and isocamphoric acid Amino acids such as aminobutyric acid and alanine. Two or more of these may be used in combination. Among these, oxalic acid is preferable because it is easily dispersed in an organic solvent, properties of a product of a reaction between an acid and a metal complex, availability, and the like.

  The organic sulfonic acid that can be used in the present invention, that is, the organic substance containing a sulfonic acid group is not particularly limited, and examples thereof include methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butanesulfonic acid, pentanesulfonic acid, and the like. Saturated aliphatic monofunctional sulfonic acids, 1,2-ethanesulfonic acid, 1,3-propanesulfonic acid, 1,4-butanesulfonic acid, 1,5-pentanesulfonic acid, and the like. Aromatic monofunctional sulfone such as functional sulfonic acid, benzenesulfonic acid, o-toluenesulfonic acid, m-toluenesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid, naphthylaminesulfonic acid, aminophenolsulfonic acid Acid, etc. Two or more of these may be used in combination. Among these, benzenesulfonic acid or a derivative thereof is preferable from the viewpoint of easy dispersion in an organic solvent, properties of a product of reaction between an acid and a metal complex, availability, and the like. Among them, p-toluene is preferable. Sulphonic acid is more preferred.

  In selecting an organic acid that can be suitably used, conditions will be described in detail. First, the organic acid generates a metal complex centered on copper to be removed and a metal salt. Second, the metal salt produced can be separated from the polymer solution or melt. Third, organic acids do not have a fatal effect on the polymer. The organic acid itself may be a liquid or a solid, but any organic acid may be used as long as the above conditions are satisfied.

  These conditions will be described in more detail. First, in order for an organic acid to produce a metal complex and a metal salt centered on copper to be removed, the organic acid needs to have an acidity of a certain level or more. If the dissociation constant in the aqueous solution of the organic compound is used as the acidity index, the logarithmic value (pKa) of the reciprocal of the acid dissociation constant of the first dissociation stage is preferably 6.0 or less, and 5.5 or less. More preferably, it is more preferably 5.0 or less. Regarding the dissociation constant, for example, Table 10.11 on page II-339 of the basic edition of Chemistry Handbook (Revised 3rd Edition, edited by The Chemical Society of Japan, 1984), etc. For example, the pKa of acetic acid is 4.56, the pKa of benzoic acid is 4.20, and the pKa of oxalic acid is 1.04 (first stage) and 3.82 (second stage). Although the values of benzenesulfonic acid and p-toluenesulfonic acid are not listed in the above table, both are soluble in water, and pKa of benzenesulfonic acid is −2.7 (page 942 of the organic compound dictionary, organic synthesis). 1985), and p-toluenesulfonic acid is considered to be as strong acid as hydrochloric acid and sulfuric acid (Organic Compound Dictionary, page 645, Synthetic Organic Chemistry Association, 1985). Both can be assumed to be about 2. In the case of an organic acid that is insoluble in water, it can be inferred from its derivative and water-soluble organic acid and the strength relationship with other acids.

  Second, in order for the produced metal salt to be separable from the polymer solution or melt, the solubility of the produced metal salt in the solvent is preferably small, more preferably poorly soluble, and insoluble. Most preferably. Although it is difficult to predict the solubility of the metal salt in advance, it is possible to refer to the solubility of the metal complex in the solvent and the solubility of the organic acid used in the solvent.

Third, in order for the organic acid not to have a fatal effect on the polymer, the polymer main chain or side chain has a structure that is not decomposed by the acid, and the polymer has a functional group that reacts with the acid. Preferably not. If not preferred, it is necessary to adjust the amount and concentration of the organic acid to be reacted, reaction temperature, reaction time, solvent and the like. However, the case where the functional group of the polymer is converted to a desired functional group by reacting with an acid, or the case where the functional group can be returned to the original state by a chemical means even when it reacts with an acid is excluded.
Assuming that the metal complex is partially decomposed by the action of the organic acid, it is preferable that the liberated ligand can be removed. That is, it is preferable that the liberated ligand is insoluble in the solvent or an organic salt insoluble in the solvent is generated by the reaction between the ligand and the organic acid. Although it is difficult to predict the solubility of this salt in advance, it is possible to refer to the solubility of the ligand in the solvent and the solubility of the organic acid used in the solvent.

  There is no particular limitation on whether the organic acid is used as it is, as an aqueous solution, or as a solution of an organic solvent, but any one may be used as long as the above conditions are satisfied.

  The metal complex to be removed in the present invention is not particularly limited, and may be a metal complex formed by a reaction between copper halide and a nitrogen-containing ligand. The nitrogen-containing ligand mentioned here may be a chelate ligand having two or more coordination sites. This is because the metal complex preferably used as the catalyst for the atom transfer radical polymerization is a metal complex having monovalent copper as a central metal, and examples of the monovalent copper compound include cuprous chloride and first bromide. Copper halides such as copper, and nitrogen-containing ligands such as 2,2'-bipyridyl, derivatives thereof (eg, 4,4'-dinolyl-2,2) to enhance catalytic activity 2,2'-bipyridyl compounds such as' -bipyridyl, 4,4'-di (5-noryl) -2,2'-bipyridyl, etc.), 1,10-phenanthroline, and derivatives thereof (for example, 4,7-dinolyl) 1,10-phenanthroline, 5,6-dinolyl-1,10-phenanthroline, etc.), tetramethyldiethylenetriamine (TM DA), there are cases where pentamethyldiethylenetriamine, hexamethyl (2-aminoethyl) polyamines such as amine, chelating ligand having two or more coordination sites, such as are added. Of course, the metal complex that can be removed in the present invention is not limited to the catalyst of the atom transfer radical polymerization, and may be a metal complex having no catalytic function.

  The amount of the organic acid used in the present invention is preferably 1 mol or more per 1 mol of copper contained in the metal complex centered on copper. Moreover, it is preferable that it is 0.5 mol of organic acids per 1 mol of coordination positions of a ligand, and it is more preferable that it is 1.0 mol or more of organic acids. When the amount of the organic acid is increased, the reaction time is shortened. However, from the viewpoint of cost and the necessity of removing excess organic acid, it is desirable to suppress the reaction time to a necessary amount. The reaction for adding an organic acid of the present invention can be carried out in the absence of a solvent (polymer melt) or in various solvents.

  Examples of the solvent include hydrocarbon solvents such as benzene and toluene; ether solvents such as diethyl ether and tetrahydrofuran; halogenated hydrocarbon solvents such as methylene chloride and chloroform; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. Solvent: Alcohol solvents such as methanol, ethanol, propanol, isopropanol, n-butanol and t-butanol; Nitrile solvents such as acetonitrile, propionitrile and benzonitrile; Ester solvents such as ethyl acetate and butyl acetate; Ethylene carbonate And carbonate solvents such as propylene carbonate. These may be used alone or in combination of two or more.

  When a solvent is used, the amount used may be appropriately determined from the relationship between the viscosity of the entire system, the required stirring efficiency, and the reaction rate. The reaction can be performed in the range of 0 ° C to 200 ° C, preferably in the range of room temperature to 150 ° C.

  The method for removing the metal salt produced as a result of the reaction is not particularly limited, and known methods such as filtration using a filter press, decantation, and centrifugal sedimentation can be used as necessary. In the case of filtration, a filter aid typified by diatomaceous earth can be added to improve the clarity of the liquid and to improve the filtration rate. Examples of the method for adding the filter aid include a method in which the filter aid is mixed in advance with the slurry, a method in which the filter medium surface is pre-coated, and a method in which these are used in combination.

  In addition, if necessary, it may be possible to proceed to the next neutralization step without removing the metal salt. However, even in this case, the metal salt must be removed after the neutralization step. When the metal salt remains in the solid acrylic block copolymer, there is a fear that the polymer deterioration during the removal of the volatile component by the reduced pressure extruder and the physical properties of the molded article may be adversely affected.

  After removing the metal complex by adding an organic acid to a mixture containing a polymer and a metal complex with copper as the central metal, the system may approach the acidic side, which may be a problem. . Therefore, a process for neutralizing the system may be required. As a method for neutralizing the system, a known method can be used, and there is no particular limitation. For example, a method using a basic solid can be mentioned. Examples of basic solids include basic activated alumina, basic adsorbent, solid inorganic acid, anion exchange resin, cellulose anion exchanger and the like. Examples of the basic adsorbent include KYOWARD 500SH (manufactured by Kyowa Chemical). Examples of the solid inorganic acid include Na2O, K2O, MgO, and CaO. Examples of the anion exchange resin include a styrene strong basic anion exchange resin, a styrene weak basic anion exchange resin, and an acrylic weak base type anion exchange resin.

  The method for removing the adsorbent added during the neutralization step is not particularly limited, and known methods such as filtration using a filter press, decantation, and centrifugal sedimentation can be used as necessary. As described above, in the case of filtration, a filter aid can be used in combination.

  The acrylic block copolymer (A) produced by the above production method is characterized by excellent weather resistance, heat resistance, durability and oil resistance. Further, by appropriately selecting the components constituting the block body, an elastomer that is extremely flexible compared to other thermoplastic elastomers such as a styrene-based block body is provided, so that an alternative to a crosslinked rubber is expected.

<Method for producing particles of acrylic block copolymer (A)>
The particles of the present invention have an SP value of 16.9 or less, or 21.1 or more while applying stirring force of 0.1 kW / m ³ or more to the acrylic block copolymer solution. It is obtained by dropping a poor solvent having a solubility parameter.

  The tank used for reprecipitation is preferably a batch-type agitation tank because it requires the mixing of a polymer solution ranging from a low viscosity to a high viscosity and strong mechanical stirring capable of pulverizing the reprecipitated polymer. A stirring tank equipped with a small stirring blade that can be finely pulverized is more preferable.

  For the purpose of finely pulverizing the polymer with low power, it is preferable to use, for example, a disk turbine type blade and paddle type blade for the stirring blade, and efficiently generate a high shear field with low power. More preferred are blue margin wings and Mig wings.

Stirring power required to sufficiently stir and mix the polymer solution and pulverize the re-precipitated polymer to a sphere-equivalent average diameter of 3 mm or less depends on the type of stirring blade, but when using any blade In addition, it is necessary to constantly apply a stirring force of at least 0.1 kW / m ³ or more, and 1.0 kW / m ³ or more is required when the stirring time is shortened or the average particle diameter is 0.5 mm or less. It becomes. If it exceeds 5 kW / m ³ , the stirring force and shearing force are reduced due to entrainment of bubbles from the liquid surface into the polymer solution, and therefore it is preferably 5 kW / m ³ or less. More preferably, it is 2 kW / m ³ or less. The stirring power per unit volume PV [kW / m ³ ] defined in the present invention is calculated from the following equation.

PV = P0 × N ³ × D ⁵ / V × 1000
P0 is the stirring power number, the unit is dimensionless, N is the stirring blade rotation speed in units of times / second, D is the stirring blade diameter in m units, and V is the total liquid volume in m ³ units. Have. P0 becomes constant in the turbulent flow region, and shows an increasing tendency when it becomes a laminar flow region as the liquid viscosity increases. Therefore, if the rotating speed of the stirring blade is set so that the PV is 0.1 kW / m ³ or more in the polymer solution in the turbulent flow region before dropping, the PV during reprecipitation can always be kept at 0.1 kW / m ³ or more. it can. In general, P0 in the turbulent region is 5.0 for turbine blades, 4.0 for paddle blades, 1.1 for blue margin blades, and 0.8 for MIG blades. In this report, the calculation was made using the same values, and the operating conditions were determined as needed. In consideration of the influence of the increase in V due to the amount of dripping, PV during dripping was appropriately adjusted so as to be 0.1 kW / m ³ or more.

  In the solvent for dissolving the polymer, the solubility parameter (SP) value is preferably 17.0 to 21.0, and the use of acetone, toluene, ethyl acetate, butyl acetate, which is easy to handle and inexpensive, is more preferable. More preferred is ethyl acetate which is easy to refine and has a low boiling point and is advantageous for drying. These solutions can be used alone or in combination.

  The poor solvent preferably has an SP value of 16.9 or less, or 21.1 or more, and is more preferably easy to handle and relatively inexpensive methanol, hexane, heptane, octane, pentane, decane, and fine particles. More preferred is heptane which is easy to convert and has a boiling point of ethyl acetate or higher and 100 ° C. or lower, which is advantageous for drying. These solutions can be used alone or in combination.

  The acrylic block copolymer solution in the present invention is preferably 25 to 50% by weight of the acrylic block copolymer, and is 30 for shortening productivity, mixing time and pulverization time, and atomization of particles. It is more preferable to set it to -40 weight%. The poor solvent is preferably added in an amount of 100 to 300 parts by weight of the poor solvent with respect to 100 parts by weight of the acrylic block copolymer solution, for the purpose of preventing reaggregation of the reprecipitated particles and reducing the burden of the solvent removal step. It is more preferable to add 150 to 250 parts by weight.

  The poor solvent is preferably added dropwise to the polymer solution in 5 to 30 minutes. In the process of dripping the poor solvent into the acrylic block copolymer solution to reprecipitate the acrylic block copolymer from the polymer solution, the polymer solution shows a significant increase in viscosity during the dripping of the poor solvent, and then remains constant. Immediately after the addition, a solid polymer is precipitated and separated from the solution. In this case, if the dropping time is shorter than 5 minutes, stirring and mixing cannot catch up with partial thickening, so that the polymer solution with high viscosity and the precipitated solid polymer are mixed, and the tank wall has a large scale. In addition to the generation of the polymer and the pulverization of the polymer by stirring, the polymer lump may be wound around the stirring blade and the stirring may be stopped. Therefore, the time required for the dropping is preferably at least 5 minutes in order to maintain uniformity by stirring and mixing the polymer solution and the poor solvent, and a sudden change in viscosity is disadvantageous for scale-up, so that it takes 10 minutes or more. It is more preferable to do. On the other hand, the dropping time is preferably within 30 minutes from the viewpoint of productivity.

  In order to prevent aggregation of acrylic block copolymer particles that occur in the reprecipitation step, filtration step and drying step after the acrylic block copolymer is precipitated, it is effective to add an anti-adhesive agent composed of an inorganic compound. It is. It is preferable that 0.1 to 10 parts by weight of an inorganic compound is added to 100 parts by weight of the acrylic block polymer after the acrylic block copolymer particles are precipitated. Of the inorganic compounds, talc or calcium carbonate is preferably used. For example, when talc or calcium carbonate is used, it is preferable to add at least 0.1 part by weight or more preferably 2.0 parts by weight or more with respect to 100 parts by weight of the deposited acrylic block copolymer. It is preferable to do. The addition of 10 parts by weight or more is preferably not more than 10 parts by weight in order not only to disperse in the solution without adhering to the solid surface but to contribute to the anti-adhesion effect, and to reduce the filtration separation ability.

  As for the diameter of the acrylic block copolymer particles, it is preferable that the average particle diameter corresponding to a sphere is 0.01 to 3.00 mm. The filtration method may be batch or continuous, and various types such as those using pressure and those using centrifugal force may be used for solid-liquid separation.

  The polymer particles during drying are likely to agglomerate due to increased adhesion of the solid surface due to the heat in the dryer and the residual solution, so it is necessary to dry quickly under vacuum and to prevent agglomeration during drying. . Therefore, it is desirable to use a vacuum dryer equipped with a stirring blade for stirring the polymer particles.

  The higher the drying temperature, the higher the drying speed. However, at a high temperature of 120 ° C. or higher, the polymer becomes soft and easily aggregates. Therefore, the temperature is preferably 60 to 120 ° C., and 80% for promoting drying and reducing aggregation. More preferably, the temperature is from 100 to 100 ° C. Further, the shorter the drying time is, the more the aggregation of polymer particles during drying can be reduced. Therefore, the drying time is preferably within 20 minutes, more preferably within 10 minutes.

  The residual solution in the polymer particles contains a solvent for dissolving the polymer and a poor solvent, and the poor solvent has almost no property of aggregating the polymer, but the residual amount of the solvent having the property of dissolving the polymer is small. When the amount is large, polymer particles tend to aggregate during drying. It is effective to remove the solvent as much as possible before drying, or to use a solvent for dissolving the polymer having a lower boiling point than the poor solvent. In this case, the difference in boiling point between the solvent for dissolving the polymer and the poor solvent is preferably 10 ° C. or more, more preferably 20 ° C. In addition, it is essential to recycle the solvent and poor solvent that dissolve the polymer in order to reduce production costs. At this time, in order to simplify the separation of the solvent and the poor solvent, a solution that does not have an azeotropic composition with each other. It is preferable to select.

Hereinafter, a method for producing particles of an acrylic block copolymer will be described with specific examples. 100 parts by weight of an acrylic block copolymer and 200 parts of a solvent for dissolving the polymer were weighed into a separable flask having an inner volume of 2 L (diameter 12 cm) equipped with four baffle plates, and the solution depth was 1/2. A paddle type stirring blade having a diameter of 5 cm was installed at the position, and stirring force of 0.1 kW / m ³ was applied and stirred for 10 minutes to completely dissolve the acrylic block copolymer to prepare the polymer solution. To do. While stirring the polymer solution, 300 parts by weight of the poor solvent is dropped little by little into the polymer solution. At this time, if the poor solvent is dripped quickly into the polymer solution, the polymer solution shows a marked increase in viscosity and the stirring is stopped, or the acrylic block copolymer is restarted due to insufficient stirring and mixing due to an increase in the viscosity or the amount of liquid. Since unevenness occurs in the settling state, the re-precipitated solution is slowly dropped over 5 minutes or more, and the stirring rotation speed is also increased appropriately as the amount of the solution increases, so that the stirring power is always 0.1 kW / m ³ or more. . After reprecipitation is started, the stirring speed is further increased, the reprecipitated acrylic block copolymer is pulverized and dispersed by stirring, and stirring is continued until the acrylic block copolymer reaches a predetermined particle size. . When the predetermined particle size is reached, 5 parts by weight of talc is added, and further stirred for 3 minutes to adhere the talc to the copolymer. The mixed solution containing the acrylic block copolymer re-precipitated in the separable flask after stopping the stirring is transferred onto a filter paper, and the precipitated acrylic block copolymer is separated. The resulting acrylic block copolymer containing some solution is transferred to a petri dish and dried for 10 to 30 minutes in a dryer set at 80 ° C. During drying, the acrylic block copolymer in the petri dish is lightly agitated with a spatula at intervals of once every 3 minutes to promote drying and reduce aggregation. After completion of drying, the petri dish is taken out from the dryer, and the acrylic block copolymer is lightly stirred with a spatula to obtain particles of an acrylic block copolymer having a sphere equivalent diameter of 0.01 to 3.00 mm. .

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. The table summarizes the conditions and results of the examples and comparative examples.

(Comparative Example 1)
50 g of the acrylic block copolymer and 200 g of the polymer were weighed into a beaker and stirred and mixed with a magnetic stirrer for 10 minutes to completely dissolve the acrylic block copolymer to prepare the polymer solution. 500g of octane was weighed into a 2L separable flask equipped with 4 baffle plates, and a paddle type stirring blade with a diameter of 5cm was installed at about 1/2 of the solution depth, and 0.1kW / m ³ or more The polymer solution was added dropwise little by little over 10 minutes while applying the stirring force of. After 10 minutes, the stirring was stopped and the polymer in the separable flask was observed. As a result, the polymer was in a flat amoeba shape having a diameter of about 5 mm and could not be formed into particles.

(Example 1)
100 g of acrylic block copolymer and 300 g of ethyl acetate are weighed into a 2 L separable flask equipped with 4 baffles and a blue margin with a diameter of 6 cm at about 1/2 the depth of the solution. A stirring blade is installed and stirring force of 0.13 kW / m ³ or more (stirring blade rotation speed: 400 times / min) is applied while stirring for 10 minutes to completely dissolve the acrylic block copolymer. A polymer solution was prepared. While stirring the polymer solution, 800 g of octane was dropped into the polymer solution little by little over 3 minutes. After starting reprecipitation, the acrylic block copolymer deposited by stirring and mixing for 10 minutes was pulverized into particles. The slurry solution containing the polymer particles re-precipitated in the separable flask after stopping the stirring was transferred onto a filter paper to separate the polymer particles. The polymer particles were transferred to a petri dish and dried for 10 minutes while stirring the acrylic block copolymer in the petri dish with a spatula at an interval of once every 3 minutes in a dryer set at 80 ° C. After completion of the drying, the petri dish was taken out of the dryer, and the acrylic block copolymer was lightly stirred with a spatula to obtain 2.0 mm acrylic block copolymer particles having a sphere equivalent average diameter.

(Comparative Example 2)
The experiment was performed in the same manner as in Example 1 except that the stirring force was 0.02 kW / m ³ (the stirring blade speed was 200 times / min). At the time of reprecipitation, the polymerization solution partially showed significant thickening and was wound around a stirring blade to form a large mass.

(Example 2)
The experiment was performed in the same manner as in Example 1 except that 100 g of ethyl acetate was used. Since the liquid viscosity was high and a large lump was partially formed, it became difficult to atomize, and finally, large polymer particles having a diameter of about 2.0 mm were obtained.

(Example 3)
The experiment was performed in the same manner as in Example 1 except that the dropping rate of octane was 10 minutes. Particles with a diameter of 0.8 mm were obtained.

Example 4
After reprecipitation and pulverization, an experiment was performed in the same manner as in Example 3 except that 5 g of talc was added and the mixture was further stirred and mixed for 3 minutes. Particles having a diameter of 0.6 mm were obtained.

(Example 5)
The experiment was performed in the same manner as in Example 4 except that 300 g of heptane was used as the poor solvent. Compared with the particles obtained in Experimental Example 4, although the difference in boiling point between the solvent and the poor solvent was small, particles having a diameter of 0.8 mm were obtained although they showed a slight tendency to agglomerate during drying.

(Example 6)
The experiment was performed in the same manner as in Example 4 except that 300 g of toluene was used instead of ethyl acetate. Although the difference between the boiling points of the solvent and the poor solvent was small, particles having a diameter of 0.8 mm were obtained although there was a tendency to agglomerate during drying. Particles were also obtained in a non-azeotropic solvent system.

  The results are summarized in Tables 1 and 2.

Claims (11)

Poor having an SP value (solubility parameter) of 16.9 or less, or 21.1 or more while applying a stirring force of 0.1 kW / m ³ or more to the acrylic block copolymer solution. A method for producing acrylic block copolymer particles obtained by dropping a solvent.   2. The method for producing acrylic block copolymer particles according to claim 1, wherein an average particle diameter corresponding to a sphere is 0.01 to 3.00 mm.   The method for producing acrylic block copolymer particles according to claim 1 or 2, wherein the SP value of the solvent of the acrylic block copolymer solution is 17.0 to 21.0.   The acrylic block copolymer solution is a solution containing 25 to 50% by weight of an acrylic block copolymer, and 100 to 300 parts by weight of a poor solvent is added to 100 parts by weight of the polymer solution. The manufacturing method of the acryl-type block copolymer particle of any one of Claims 1-3.   The method for producing acrylic block copolymer particles according to any one of claims 1 to 4, wherein the poor solvent is dropped into the polymer solution in 5 to 30 minutes.   The method for producing acrylic block copolymer particles according to any one of claims 1 to 5, wherein the poor solvent is methanol, hexane, heptane, octane or decane.   The acrylic block copolymer particle according to any one of claims 1 to 6, wherein the solvent of the acrylic block copolymer solution is at least one member selected from the group consisting of acetone, toluene, and ethyl acetate. Manufacturing method.   The inorganic compound is added in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the acrylic block polymer after the acrylic block copolymer particles are precipitated. A method for producing the acrylic block copolymer particles according to 1.   The method for producing acrylic block copolymer particles according to claim 8, wherein the inorganic compound is talc or calcium carbonate.   The acrylic block copolymer according to any one of claims 1 to 9, wherein the acrylic block copolymer comprises an acrylic polymer block (a) and a methacrylic polymer block (b). Production method of polymer particles.   The method for producing acrylic block copolymer particles according to any one of claims 1 to 10, wherein the acrylic block copolymer is produced by atom transfer radical polymerization.