Method for producing carboxyl-group-containing nitrile rubber

Patent metadata

Field	Value
Publication number	US-11161920-B2
Application number	US-201816495003-A
Country	US
Kind code	B2
Filing date	Mar 23, 2018
Priority date	Mar 28, 2017
Publication date	Nov 2, 2021
Grant date	Nov 2, 2021

Abstract

A method of producing a carboxyl group-containing nitrile rubber including a coagulation step of coagulating a carboxyl group-containing nitrile rubber component by mixing a monovalent metal salt and a polymer flocculating agent into a carboxyl group-containing nitrile rubber latex having an iodine value of 120 or less, wherein the monovalent metal salt is compounded in an amount of 3 to 25 parts by weight and the polymer flocculating agent is compounded in an amount of 0.01 to 10 parts by weight relative to 100 parts by weight of a rubber solid content in the latex, and a weight ratio of the monovalent metal salt/the polymer flocculating agent is in the range of 10 to 500

First claim

The invention claimed is:

1. A method of producing a carboxyl group-containing nitrile rubber, the method comprising a coagulation step of coagulating a carboxyl group-containing nitrile rubber component by mixing a monovalent metal salt and a polymer flocculating agent into a carboxyl group-containing nitrile rubber latex, wherein the monovalent metal salt is compounded in an amount of 3 to 25 parts by weight and the polymer flocculating agent is compounded in an amount of 0.01 to 10 parts by weight relative to 100 parts by weight of a rubber solid content in the latex, and a weight ratio of the monovalent metal salt/the polymer flocculating agent is in the range of 10 to 500.

2. The method of producing a carboxyl group-containing nitrile rubber according to claim 1 , wherein the polymer flocculating agent is a cationic polymer flocculating agent.

3. The method of producing a carboxyl group-containing nitrile rubber according to claim 1 , wherein the polymer flocculating agent is a condensate formed by co-condensating (A), (B) and/or (C) described below:
(A) at least one selected from alkylamines and alkanolamines, or a mixture of at least one selected from alkylamines and alkanolamines with ammonia;
(B) epihalohydrin; and
(C) a compound represented by general formula (1) described below:

wherein R 1 , R 2 and R 3 each independently denote a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms or a benzyl group, A denotes a halogen atom, and X 1− denotes an arbitrary anion.

4. The method of producing a carboxyl group-containing nitrile rubber according to claim 1 , wherein the carboxyl group-containing nitrile rubber contains an α, β-ethylenically unsaturated carboxylate ester monomer unit.

5. A method of producing a crosslinkable rubber composition, the method comprising a step of compounding a crosslinking agent to a carboxyl group-containing nitrile rubber obtained through the production method according to claim 1 .

6. A method of producing a crosslinked rubber product, the method comprising a step of crosslinking a crosslinkable rubber composition obtained through the production method according to claim 5 .

Assignees

• Zeon Corp

Inventors

• Herai Taiki
• Yoshimura Tsutomu

Classifications

• C08J3/24

  Crosslinking, e.g. vulcanising, of macromolecules (mechanical aspects B29C35/00; crosslinking agents C08K) · CPC title

• C08C1/15 Primary

  characterised by the coagulants used · CPC title

• C08F6/22

  Coagulation · CPC title

• C08L9/04

  Latex · CPC title

• C08C19/02 Primary

  Hydrogenation · CPC title