# US 9,751,963 B2 · Vinyl resin production method

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- Number: US 9,751,963 B2
- Document ID: US9751963B2
- Status: Granted
- Kind: B2
- Application number: 15/302,281
- Filed: 2015-04-08
- Published: 2017-02-02
- Granted: 2017-09-05
- Earliest claimed: 2014-04-09
- Assignees: Kuraray Co., Ltd.; Kuraray Europe GmbH
- Applicants: Kuraray Co., Ltd.; Kuraray Europe GmbH
- Inventors: Tadahito Fukuhara; Yosuke Kumaki; Samuel Michel; Dirk Hartmann
- Web page: https://patentgrep.com/patent/US9751963B2

## CPC

- C08F 114/06: Vinyl chloride
- C08F 2/20: with the aid of macromolecular dispersing agents
- C08F 2/18: Suspension polymerisation
- C08F 14/06: Vinyl chloride
- C08F 2400/00: Characteristics for processes of polymerization
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS

## Abstract

A dispersion stabilizer in the present invention contains an aqueous emulsion (a) obtained by dispersing a polymer (A) having an ethylenically unsaturated monomer unit in an aqueous medium, a PVA (B) having a degree of saponification of 65 mol % or more and less than 82 mol % and a viscosity-average degree of polymerization of 250 or more and less than 1500, and a PVA (C) having a degree of saponification of 82 mol % or more and less than 98 mol % and a viscosity-average degree of polymerization of 1500 or more and less than 4000. The dispersion stabilizer contains: 7 to 51 mass % of the polymer (A); 40 to 84 mass % of the PVA (B); and 9 to 53 mass % of the PVA (C), with respect to a total amount of the polymer (A), the PVA (B), and the PVA (C). A vinyl resin satisfying required performance can be obtained using the dispersion stabilizer.

## Claims

### Claim 1

A method for producing a vinyl resin, comprising:
suspension polymerizing of a vinyl compound in an aqueous medium using a dispersion stabilizer,
wherein the dispersion stabilizer comprises:
an aqueous emulsion (a) obtained by dispersing a polymer (A) having an ethylenically unsaturated monomer unit in an aqueous medium;
a polyvinyl alcohol (B) with a degree of saponification of 65 mol % or more and less than 82 mol % and a viscosity-average degree of polymerization of 250 or more and less than 1,500; and
a polyvinyl alcohol (C) with a degree of saponification of 82 mol % or more and less than 98 mol % and a viscosity-average degree of polymerization of 1,500 or more and less than 4,000;
wherein the dispersion stabilizer comprises: 7 to 51 mass % of the polymer (A); 40 to 84 mass % of the polyvinyl alcohol (B); and 9 to 53 mass % of the polyvinyl alcohol (C), with respect to a total amount of the polymer (A), the polyvinyl alcohol (B), and the polyvinyl alcohol (C).

### Claim 2 (depends on 1)

The production method according to claim 1, wherein a solid content of the aqueous emulsion (a) is 35 to 70 mass %.

### Claim 3 (depends on 1)

The production method according to claim 1, wherein the polymer (A) includes a polyvinyl ester.

### Claim 4 (depends on 3)

The production method according to claim 3, wherein the polyvinyl ester is polyvinyl acetate.

### Claim 5 (depends on 1)

The production method according to claim 1, wherein a block character of residual vinyl ester groups in each of the polyvinyl alcohol (B) and the polyvinyl alcohol (C) is 0.55 or less.

### Claim 6 (depends on 1)

The production method according to claim 1, wherein a mass ratio of the vinyl compound with respect to the aqueous medium is 0.57 to 1.25.