Chloroprene copolymer latex, method for producing same, vulcanized product, dip molded article and method for producing same

Patent metadata

Field	Value
Publication number	US-12359044-B2
Application number	US-202017623648-A
Country	US
Kind code	B2
Filing date	Jun 30, 2020
Priority date	Jul 5, 2019
Publication date	Jul 15, 2025
Grant date	Jul 15, 2025

Abstract

A chloroprene copolymer latex containing a chloroprene copolymer having a structural unit derived from chloroprene and a structural unit derived from 2,3-dichloro-1,3-butadiene, in which a toluene insoluble content in the chloroprene copolymer is 50 to 95% by mass, and a modulus at 500% elongation of a film, which is obtained on a base material by dipping the base material in the chloroprene copolymer latex and then performing vulcanization at 100° C. for 30 minutes, according to JIS K 6251 is 4.0 MPa or less.

First claim

The invention claimed is:

1. A chloroprene copolymer latex comprising a chloroprene copolymer having a structural unit derived from chloroprene and a structural unit derived from 2,3-dichloro-1,3-butadiene, wherein
the chloroprene copolymer provides a peak derived from abietic acid in gas chromatography of an extract extracted from the chloroprene copolymer using an ethanol/toluene azeotropic mixture,
a toluene insoluble content in the chloroprene copolymer is 85 to 95% by mass, and
a modulus at 500% elongation of a film, which is obtained on a base material by dipping the base material in the chloroprene copolymer latex and then performing vulcanization at 100° C. for 30 minutes, according to JIS K 6251 is 3.5 MPa or less.

2. The chloroprene copolymer latex according to claim 1 , wherein a modulus at 100% elongation of the film according to JIS K 6251 is 0.5 to 1.2 MPa.

3. The chloroprene copolymer latex according to claim 1 , wherein a content of the structural unit derived from 2,3-dichloro-1,3-butadiene is more than 0% by mass and 35% by mass or less on the basis of a total amount of the structural unit derived from chloroprene and the structural unit derived from 2,3-dichloro-1,3-butadiene.

4. The chloroprene copolymer latex according to claim 1 , wherein the chloroprene copolymer latex does not comprise a vulcanization accelerator.

5. A vulcanizate of the chloroprene copolymer latex according to claim 1 .

6. A dip molded article of the chloroprene copolymer latex according to claim 1 .

7. The dip molded article according to claim 6 , wherein the dip molded article is gloves, balloons, catheters, or boots.

8. A method for producing a dip molded article, the method comprising a step of dip molding the chloroprene copolymer latex according to claim 1 .

9. A method for producing a chloroprene copolymer latex, the method being a production method for obtaining the chloroprene copolymer latex according to claim 1 , the method comprising:
a polymerization step of subjecting chloroprene and 2,3-dichloro-1,3-butadiene to emulsion polymerization up to a polymerization conversion rate of 60 to 95%, wherein
in the polymerization step, a content of the 2,3-dichloro-1,3-butadiene is more than 0 parts by mass and 35 parts by mass or less with respect to 100 parts by mass of the total of the chloroprene and the 2,3-dichloro-1,3-butadiene.

10. The method according to claim 9 , wherein the polymerization conversion rate is 85 to 95%.

11. The chloroprene copolymer latex according to claim 1 , wherein a content of the structural unit derived from 2,3-dichloro-1,3-butadiene is more than 0% by mass and 25% by mass or less on the basis of a total amount of the structural unit derived from chloroprene and the structural unit derived from 2,3-dichloro-1,3-butadiene.

12. The chloroprene copolymer latex according to claim 1 , wherein a content of the structural unit derived from 2,3-dichloro-1,3-butadiene is 10 to 35% by mass on the basis of a total amount of the structural unit derived from chloroprene and the structural unit derived from 2,3-dichloro-1,3-butadiene.

13. The chloroprene copolymer latex according to claim 1 , wherein the modulus at 500% elongation is 1.5 MPa or less.

14. The chloroprene copolymer latex according to claim 1 , wherein a modulus at 100% elongation of the film according to JIS K 6251 is 0.7 to 1.0 MPa.

15. A chloroprene copolymer latex comprising a chloroprene copolymer having a structural unit derived from chloroprene and a structural unit derived from 2,3-dichloro-1,3-butadiene, wherein
a toluene insoluble content in the chloroprene copolymer is 50 to 95% by mass,
a modulus at 500% elongation of a film, which is obtained on a base material by dipping the base material in the chloroprene copolymer latex and then performing vulcanization at 100° C. for 30 minutes, according to JIS K 6251 is 3.5 MPa or less, and
a modulus at 100% elongation of the film according to JIS K 6251 is 0.5 to 1.2 MPa.

16. A chloroprene copolymer latex comprising a chloroprene copolymer having a structural unit derived from chloroprene and a structural unit derived from 2,3-dichloro-1,3-butadiene, wherein
a toluene insoluble content in the chloroprene copolymer is 85 to 95% by mass, and
a modulus at 500% elongation of a film, which is obtained on a base material by dipping the base material in the chloroprene copolymer latex and then performing vulcanization at 100° C. for 30 minutes, according to JIS K 6251 is 3.5 MPa or less.

Assignees

• Denka Company Ltd

Inventors

• Onozuka Masao
• Otsuka Hidehito

Classifications

• C08F236/18 Primary

  containing chlorine · CPC title

• C09D111/02

  Latex · CPC title

• C08K2201/019

  the composition being defined by the absence of a certain additive · CPC title

• C08L93/04

  Rosin · CPC title

• C08J5/02

  Direct processing of dispersions, e.g. latex, to articles · CPC title