# US 10,766,976 B2 · Method of preparing vinyl chloride-based polymer

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,766,976 B2
- Document ID: US10766976B2
- Status: Granted
- Kind: B2
- Application number: 16/079,437
- Filed: 2017-09-19
- Published: 2019-02-14
- Granted: 2020-09-08
- Earliest claimed: 2016-09-23
- Assignees: LG Chem, Ltd.
- Applicants: LG Chem, Ltd.
- Inventors: Se Woong Lee; Seong Yong Ahn; Kun Ji Kim; Hyun Kyou Ha
- Web page: https://patentgrep.com/patent/US10766976B2

## CPC

- C08F 14/06: Vinyl chloride
- C08F 2/02: Polymerisation in bulk
- C08F 2/38: Polymerisation using regulators, e.g. chain terminating agents {, e.g. telomerisation}
- C08F 114/06: Vinyl chloride
- C08F 259/04: on to polymers of vinyl chloride
- C08K 5/00: Use of organic ingredients
- C08K 5/37: Thiols
- C08K 5/372: Sulfides {, e.g. R-(S)x-R'}
- C08F 2500/02: Low molecular weight, e.g. <100,000 Da.
- C08F 2500/03: Narrow molecular weight distribution, i.e. Mw/Mn < 3
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)

## Abstract

The present invention relates to a method of preparing a vinyl chloride-based polymer, which includes inducing the nucleation of particles by adding a mercaptan-based chain transfer agent to a monomer composition including a vinyl chloride-based monomer and a preliminary polymerization initiator (preliminary polymerization); and preparing a polymer by mixing a vinyl chloride-based monomer and the particle nuclei and adding a main polymerization initiator (main polymerization). In the preparation method, a vinyl chloride-based polymer having a uniform molecular weight distribution and a desired number average molecular weight may be provided by controlling a degree of polymerization of a vinyl chloride-based polymer prepared in such a way that dispersibility is ensured by adjusting the point of time to add the mercaptan-based chain transfer agent to the point of time to reach a specific conversion rate of the preliminary polymerization.

## Claims

### Claim 1

A method of preparing a vinyl chloride-based polymer comprising:
forming particle nuclei by adding a mercaptan-based chain transfer agent to a monomer composition including a vinyl chloride-based monomer and a preliminary polymerization initiator (preliminary polymerization); and
preparing a polymer by mixing a vinyl chloride-based monomer and the particle nuclei and adding a main polymerization initiator (main polymerization).

### Claim 2 (depends on 1)

The method of claim 1, wherein the mercaptan-based chain transfer agent is represented by Chemical Formula 1 below:
wherein R1 and R2 are the same or different from each other, are each independently hydrogen or a C1 to C20 alkyl group, and any one of R1 and R2 is combined with —OH, —COOH, or —COOR (here, R is a C1 to C5 alkyl group) when R1 and R2 are not hydrogen,
A is a C1 to C30 alkylene group, a C1 to C30 alkylene group combined with one or more hydroxy groups, or a C2 to C30 heteroalkylene group, wherein the heteroalkylene group includes one or more heteroatoms selected from N, O, and S, and
X is —OH, —COOH, or —COOR (here, R is a C1 to C5 alkyl group).

### Claim 3 (depends on 2)

The method of claim 2, wherein the mercaptan-based chain transfer agent includes one or more selected from the group consisting of 2-mercaptoethanol, 3-mercapto-1,2-propanediol, methyl mercaptodecanoate, and dimethyl 9-mercaptooctadecyl-1,18-dioate.

### Claim 4 (depends on 1)

The method of claim 1, wherein the mercaptan-based chain transfer agent is added when a conversion rate of the preliminary polymerization is 3 to 8%.

### Claim 5 (depends on 1)

The method of claim 1, wherein the mercaptan-based chain transfer agent is added in an amount of 0.01 to 0.1 parts by weight with respect to 100 parts by weight of the vinyl chloride-based monomer in the preliminary polymerization.

### Claim 6 (depends on 1)

The method of claim 1, wherein the main polymerization is performed through a bulk polymerization method.

### Claim 7 (depends on 1)

The method of claim 1, wherein a volume ratio of a reactor for the preliminary polymerization and a reactor for the main polymerization is 25:75 to 40:60.