Chloroprene-based block copolymer, latex, latex composition, and rubber composition

Patent metadata

Field	Value
Publication number	US-12492279-B2
Application number	US-202117788994-A
Country	US
Kind code	B2
Filing date	Mar 22, 2021
Priority date	Mar 26, 2020
Publication date	Dec 9, 2025
Grant date	Dec 9, 2025

Abstract

A chloroprene-based block copolymer, a latex, a latex composition, and a rubber composition that can produce a product with excellent tensile properties and flexibility without the use of a vulcanizing agent or a vulcanizing accelerator having a chloroprene-based block copolymer, contains 5 to 30% by mass of a polymer block (A) and 70 to 95% by mass of a chloroprene-based polymer block (B), wherein the polymer block (A) is derived from a monomer, when the monomer is polymerized alone, a polymer with a glass transition temperature of 80° C. or higher can be obtained and the chloroprene-based polymer block (B) includes a chloroprene monomer unit and a polyfunctional monomer unit.

First claim

The invention claimed is:

1 . A chloroprene-based block copolymer, containing 5 to 30% by mass of a polymer block (A) and 70 to 95% by mass of a chloroprene-based polymer block (B), wherein:
the polymer block (A) is derived from a monomer; when the monomer is polymerized alone, a polymer with a glass transition temperature of 80° C. or higher can be obtained; the chloroprene-based polymer block (B) includes a chloroprene monomer unit and a polyfunctional monomer unit; the polyfunctional monomer is a monomer represented by formula (1) or aromatic polyene monomer;

in the formula (1), each of R 1 and R 2 represents any one of hydrogen, chlorine, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a mercapto group, or a substituted or unsubstituted heterocyclyl group;
W 1 represents any one of a saturated or unsaturated hydrocarbon group, a saturated or unsaturated cyclic hydrocarbon group, a saturated or unsaturated hydrocarbon group containing a hetero atom, and a saturated or unsaturated cyclic hydrocarbon group containing a hetero atom;
Z 1 represents any one of oxygen, sulfur, and a structure represented by NR 0 − ;
R 0 represents any one of hydrogen, chlorine, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, mercapto group, or a substituted or unsubstituted heterocyclyl group.

2 . The chloroprene-based block copolymer of claim 1 , wherein a tensile strength at break measured in accordance with JIS K6251 of a molded body of a latex composition containing the chloroprene-based block copolymer after heat treatment at 130° C. for 30 minutes is 17 MPa or more.

3 . The chloroprene-based block copolymer of claim 1 , wherein the polymer block (A) has a number average molecular weight of 10,000 or more.

4 . The chloroprene-based block copolymer of claim 1 , wherein a molecular weight distribution of the polymer block (A) is 2.0 or less.

5 . The chloroprene-based block copolymer of claim 1 , wherein the polymer block (A) is a polymer block comprising an aromatic vinyl monomer unit.

6 . The chloroprene-based block copolymer of claim 1 , wherein:
the chloroprene-based block copolymer has a functional group of a structure represented by formula (2) or formula (3), and

in formula (2), R 3 represents any one of hydrogen, chlorine, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a mercapto group, and a substituted or unsubstituted heterocyclyl group.

7 . A latex comprising the chloroprene-based block copolymer of claim 1 .

8 . A latex composition, comprising the latex of claim 7 and an antioxidant, wherein the latex composition comprises 0.5 to 5.0 parts by mass of the antioxidant with respect to 100 parts by mass of the chloroprene-based block copolymer in the latex.

9 . A rubber composition, comprising the chloroprene-based block copolymer of claim 1 .

10 . A rubber composition, comprising the latex of claim 7 .

11 . A rubber composition, comprising the latex composition of claim 8 .

Assignees

• Denka Company Ltd

Inventors

• Mori Hideharu
• NISHINO Wataru
• KUMAGAI Yushi
• Saito Yutaka
• Kobayashi Naoki

Classifications

• C08F36/18

  containing chlorine · CPC title

• C08K5/06

  Ethers; Acetals; Ketals; Ortho-esters · CPC title

• C08F293/005

  using free radical "living" or "controlled" polymerisation, e.g. using a complexing agent · CPC title

• C08F2438/03

  Use of a di- or tri-thiocarbonylthio compound, e.g. di- or tri-thioester, di- or tri-thiocarbamate, or a xanthate as chain transfer agent, e.g . Reversible Addition Fragmentation chain Transfer [RAFT] or Macromolecular Design via Interchange of Xanthates [MADIX] · CPC title

• C08F293/00 Primary

  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) · CPC title