# US 11,028,212 B2 · Chloroprene graft copolymer latex, method for producing same, bonding agent and adhesive

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- Number: US 11,028,212 B2
- Document ID: US11028212B2
- Status: Granted
- Kind: B2
- Application number: 16/324,204
- Filed: 2017-08-01
- Published: 2019-06-06
- Granted: 2021-06-08
- Earliest claimed: 2016-08-10
- Assignees: Showa Denko K.K.
- Applicants: Showa Denko K.K.
- Inventors: Naoki Sekioka; Yuya Ohguma; Masanao Kamijo; Yoichiro Takenoshita
- Web page: https://patentgrep.com/patent/US11028212B2

## CPC

- C08F 279/02: on to polymers of conjugated dienes
- C08F 2/22: Emulsion polymerisation
- C08F 2/24: with the aid of emulsifying agents
- C08F 2/26: anionic
- C08F 265/06: Polymerisation of acrylate or methacrylate esters on to polymers thereof
- C08F 285/00: Macromolecular compounds obtained by polymerising monomers on to preformed graft polymers
- C08L 51/04: grafted on to rubbers
- C09J 111/02: Latex
- C09J 151/003: {grafted on to macromolecular compounds obtained by reactions only involving unsaturated carbon-to-carbon bonds (C09J151/04, C09J151/06 take precedence)}
- C09J 151/04: grafted on to rubbers
- 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)
- C09J: ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES (preparation of glue or gelatine C09H)

## Abstract

Provided is a method for producing a chloroprene graft copolymer latex containing no organic solvent and exhibiting high adhesive strength even for soft polyvinyl chloride. A method for producing a chloroprene graft copolymer latex includes a chloroprene polymerization step of giving a chloroprene polymer latex and a graft copolymerization step of giving a chloroprene graft copolymer latex. The chloroprene polymerization step is a step of subjecting at least chloroprene (A-1) of chloroprene (A-1) and a monomer (A-2) copolymerizable with chloroprene (A-1) to emulsion radical polymerization. The graft copolymerization step is a step of adding, to the chloroprene polymer latex, a (meth)acrylate (B) and an organic peroxide (C) having an octanol/water partition coefficient of −2.0 or more and 3.0 or less to subject the chloroprene polymer to graft copolymerization with the (meth)acrylate (B) at a temperature of 10° C. or more and 40° C. or less.

## Claims

### Claim 1

A method for producing a chloroprene graft copolymer latex, the method comprising:
a chloroprene polymerization step of subjecting monomer material consisting of (i) chloroprene (A-1) or (ii) chloroprene (A-1) and a monomer (A-2) copolymerizable with chloroprene (A-1) to emulsion radical polymerization to give a chloroprene polymer, and yielding a chloroprene polymer latex in which particles of the chloroprene polymer are dispersed in water; and
a graft copolymerization step of adding, to the chloroprene polymer latex, a (meth)acrylate (B) represented by general formula: CH2═CR—CO—OR′ (in the general formula, R is a methyl group or a hydrogen atom; and R′ is an alkyl group having a carbon number of 4 or more and 12 or less), adding, as a polymerization initiator, an organic peroxide (C) having an octanol/water partition coefficient of −2.0 or more and 3.0 or less to subject the chloroprene polymer to graft copolymerization with the (meth)acrylate (B) at a temperature of 10° C. or more and 40° C. or less to give a chloroprene graft copolymer, and yielding a chloroprene graft copolymer latex in which particles of the chloroprene graft copolymer are dispersed in water;
wherein the chloroprene polymer latex contains no organic solvent, and
wherein the monomer (A-2) is selected from the group consisting of 2,3-dichloro-1,3-butadiene, 1-chloro-1,3-butadiene, butadiene, isoprene, styrene, methacrylic acid, acrylic acid, itaconic acid, 2-ethylmethacrylic acid and 2-butylacrylic acid.

### Claim 2 (depends on 1)

The method for producing a chloroprene graft copolymer latex according to claim 1, wherein in the graft copolymerization step, the (meth)acrylate (B) is added in an amount of 1 part by mass or more and 90 parts by mass or less relative to 100 parts by mass of the chloroprene polymer.

### Claim 3 (depends on 2)

The method for producing a chloroprene graft copolymer latex according to claim 2, wherein in the chloroprene graft copolymer latex, a tetrahydrofuran insoluble matter content is not less than 6% by mass and less than 70% by mass of the chloroprene graft copolymer.

### Claim 4 (depends on 2)

The method for producing a chloroprene graft copolymer latex according to claim 2, wherein in the chloroprene polymerization step, at least one of an anionic emulsifier and a nonionic emulsifier is used to perform the emulsion radical polymerization.

### Claim 5 (depends on 1)

The method for producing a chloroprene graft copolymer latex according to claim 1, wherein in the chloroprene graft copolymer latex, a tetrahydrofuran insoluble matter content is not less than 6% by mass and less than 70% by mass of the chloroprene graft copolymer.

### Claim 6 (depends on 5)

The method for producing a chloroprene graft copolymer latex according to claim 5, wherein in the chloroprene polymerization step, at least one of an anionic emulsifier and a nonionic emulsifier is used to perform the emulsion radical polymerization.

### Claim 7 (depends on 1)

The method for producing a chloroprene graft copolymer latex according to claim 1, wherein in the chloroprene polymerization step, at least one of an anionic emulsifier and a nonionic emulsifier is used to perform the emulsion radical polymerization.

### Claim 8 (depends on 1)

The method for producing a chloroprene graft copolymer latex according to claim 1, wherein a polymerization terminator is added to stop the polymerization reaction after completion of the chloroprene polymerization step.