Polyurethanes with reduced cobalt extractables

Patent metadata

Field	Value
Publication number	US-2024034830-A1
Application number	US-202118013046-A
Country	US
Kind code	A1
Filing date	Jul 12, 2021
Priority date	Jul 17, 2020
Publication date	Feb 1, 2024
Grant date	—

Abstract

Polyurethanes are made by curing a reaction mixture containing a polyether polyol that contains residues of a zinc hexacyanocobaltate catalyst complex. The reaction mixture contains certain chelating agents in small quantities. The amount of cobalt that is extractable from the polyurethane is reduced.

First claim

1 . A method of producing a polyurethane, comprising the steps of
(I) forming a curable reaction mixture by combining ingredients comprising a) at least one polyisocyanate, b) a polyether polyol having a hydroxyl number of at most 250 mg KOH/g or a mixture of two or more polyether polyols each having a hydroxyl number of at most 250 mg KOH/g, wherein the polyether polyol or mixture of polyether polyols contains metal-containing residues of a zinc hexacyanocobaltate catalyst complex and c) 0.02 to 0.1 part by weight, per 100 parts by weight of b), of a chelating agent having a number average molecular weight of at most 3000 g/mol and at least two carboxylic acid groups and/or carboxylate groups, wherein the carboxylate group(s) are associated with a monovalent anion, and the carbonyl carbon atom of each carboxylic acid group and/or carboxylate group is not bonded directly to the carbonyl carbon atom of another carboxylic acid or carboxylate group and (II) curing the curable reaction mixture to produce the polyurethane.

2 . The method of claim 1 wherein in step (I) the ingredients further comprise at least one blowing agent, and the polyurethane is a flexible polyurethane foam having an airflow of at least 0.8 L/s as measured according to ASTM D3574 test G.

3 . The method of claim 2 wherein the at least one blowing agent includes water.

4 . The method of claim 2 wherein in step (I) the ingredients further comprise at least one surfactant and at least one urethane catalyst.

5 . The method of claim 2 wherein the chelating agent contains at least N—CH 2 —C(O)OH or N—CH 2 —C(O)O − M + unit, where the nitrogen is an amino or imino nitrogen.

6 . The method of claim 5 wherein the chelating agent includes at least one H—O(O)C—CH 2 —NR—CH 2 —C(O)O—H, H—O(O)C—CH 2 —NR—CH 2 —C(O) − M + and/or M +− O(O)C—CH 2 —NR—CH 2 —C(O) − M + structure where R is an aliphatic group that may be substituted or unsubstituted, and saturated or unsaturated.

7 . The method of claim 2 wherein the chelating agent is selected from the group consisting of ethylenediamine tetraacetic acid, N-hydroxyethyl ethylenediamine N,N′,N′-triacetic acid; 1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetracetic acid, tetraxetan, ethylene diamine-N,N′-bis(2-hydroxyphenylacetic acid), ethylene diamine-N,N′-disuccinic acid, egtazic acid, ethylene diamine N,N′-diacetic acid, glutamic acid, iminodiacetic acid, kainic acid, nitrilotriacetic acid and diethylene triamine pentaacetic acid, and partially or fully neutralized salts of any of the foregoing with a monovalent anion.

8 . The method of claim 2 wherein the chelating agent is selected from the group consisting of homopolymers of acrylic acid, homopolymers of methacrylic acid, copolymers of acrylic acid and/or methacrylic acid and partially and fully neutralized salts of any of the foregoing with a monovalent anion.

9 . The method of claim 2 wherein b) includes 10 to 100% by weight, based on the weight of b), of at least one random copolymer of propylene oxide and ethylene oxide having an oxyethylene content of 45 to 65% by weight made using a zinc hexacyanocobaltate catalyst complex and containing cobalt-containing residues of the zinc hexacyanocobaltate catalyst complex.

10 . A polyurethane made according to the method of claim 1 .

Assignees

• Dow Global Technologies Llc

Inventors

• Grzesiak Adam L
• Strother Jacob W
• Mcdougal Nolan T
• Keaton Richard J
• Laitar David S
• Rosen Mari S
• Aou Kaoru
• Willumstad Thomas P

Classifications

• C08G18/4816 Primary

  mixtures of two or more polyetherpolyols having at least three hydroxy groups · CPC title

• C08G18/485

  containing mixed oxyethylene-oxypropylene or oxyethylene-higher oxyalkylene end groups · CPC title

• C08G18/4829

  Polyethers containing at least three hydroxy groups (C08G18/4833 - C08G18/5096 take precedence) · CPC title

• C08G18/7671

  containing only one alkylene bisphenyl group · CPC title

• C08G18/244

  tin salts of carboxylic acids · CPC title