# US 12,006,406 B2 · Method for producing acrylic block copolymer pellets

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- Number: US 12,006,406 B2
- Document ID: US12006406B2
- Status: Granted
- Kind: B2
- Application number: 16/973,924
- Filed: 2019-05-28
- Published: 2021-04-22
- Granted: 2024-06-11
- Earliest claimed: 2018-06-12
- Assignees: Kuraray Co., Ltd.
- Applicants: Kuraray Co., Ltd.
- Inventors: Makoto Akai; Tomohiro Ono; Moe Kawahara
- Web page: https://patentgrep.com/patent/US12006406B2

## CPC

- C08J 3/12: Powdering or granulating
- C08J 3/124: {Treatment for improving the free-flowing characteristics}
- C08F 220/14: Methyl esters {, e.g. methyl (meth)acrylate}
- C08F 293/00: Macromolecular compounds obtained by polymerisation on to a macromolecule having groups capable of inducing the formation of new polymer chains bound exclusively at one or both ends of the starting macromolecule (on to polymers modified by introduction of unsaturated end groups C08F290/02)
- C08F 297/026: {polymerising acrylic acid, methacrylic acid or derivatives thereof}
- C08L 33/12: Homopolymers or copolymers of methyl methacrylate
- C08L 53/00: Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
- C08F 220/18: with acrylic or methacrylic acids
- C08J 2353/00: Characterised by the use of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives of such polymers
- C08J 2355/00: Characterised by the use of homopolymers or copolymers, obtained by polymerisation reactions only involving carbon-to-carbon unsaturated bonds, not provided for in groups C08J2323/00 - C08J2353/00
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)

## Abstract

Pellets of an acrylic block copolymer are provided which are imparted with sufficient antiblocking properties without deterioration in the outstanding performance of the acrylic block copolymer such as transparency. A method for producing pellets (D) including an acrylic block copolymer (A) includes bringing raw pellets of an acrylic block copolymer (A) into contact with an aqueous dispersion (C) containing acrylic resin particles (B) and no surfactants, the acrylic block copolymer (A) including at least one polymer block (a1) including acrylic acid alkyl ester units and at least one polymer block (a2) including methacrylic acid alkyl ester units, and removing water attached to the pellets.

## Claims

### Claim 1

A method for producing pellets (D) including an acrylic block copolymer (A), the method comprising:
dry grinding and wet grinding an acrylic resin to produce acrylic resin particles (B);
contacting raw pellets of an acrylic block copolymer (A) with an aqueous dispersion (C) comprising acrylic resin particles (B) and no surfactants, the acrylic block copolymer (A) comprising a polymer block (a1) comprising acrylic acid alkyl ester units and a polymer block (a2) comprising methacrylic acid alkyl ester units; and
removing water attached to the pellets.

### Claim 2 (depends on 1)

The method of claim 1, wherein the acrylic resin particles (B) in the aqueous dispersion (C) comprise not less than 85 mass % of methyl methacrylate units.

### Claim 3 (depends on 1)

The method of claim 1, wherein the acrylic resin particles (B) in the aqueous dispersion (C) have a D50 value in a particle size distribution of from 1 to 50 μm.

### Claim 4 (depends on 1)

The method of claim 1, wherein the solid concentration of the acrylic resin particles (B) in the aqueous dispersion (C) is in a range of from 0.05 to 2.0 mass %.

### Claim 5 (depends on 1)

The method of claim 1, wherein, in the contacting, the raw pellets of the acrylic block copolymer (A) are brought into contact with the aqueous dispersion (C) having a temperature in a range of from 10 to 80° C.

### Claim 6 (depends on 1)

The method of claim 1, wherein the acrylic block copolymer (A) comprises, in the molecule thereof, a structure in which a polymer block (a2) comprising methacrylic acid alkyl ester units is bonded to each of both ends of a polymer block (a1) comprising acrylic acid alkyl ester units, and
wherein the acrylic block copolymer (A) has a weight average molecular weight in a range of from 30,000 to 250,000 and a content of the polymer blocks (a2) in a range of from 5 to 40 mass %.