Water-based polyurethane dispersions and their preparation

Patent metadata

Field	Value
Publication number	US-11267925-B2
Application number	US-201716626736-A
Country	US
Kind code	B2
Filing date	Jun 30, 2017
Priority date	Jun 30, 2017
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

A prepolymer comprising acid functionality is made by a process comprising the step of contacting: (i) a di-isocyanate, (ii) a polyol containing an acid group, (iii) a polyol without an acid group, and (iv) a metal salt catalyst, the contacting conducted under reaction conditions and in a solvent consisting essentially of: (A) a dialkyl amide, and (B) optionally, an aprotic glycol ether. The prepolymer is useful in the preparation of water-based polyurethane dispersions, and certain of the solvent blends consisting essentially of a dialkyl amide and an optional aprotic glycol ether are azeotropic or pseudo-azeotropic.

First claim

The invention claimed is:

1. A process for making a prepolymer comprising an acid group, the process comprising the step of contacting
(i) a di-isocyanate,
(ii) a polyol containing an acid group,
(iii) a polyol without an acid group, and
(iv) a metal salt catalyst,

the contacting conducted under reaction conditions and in a solvent consisting of:
(A) a first component consisting of at least one dialkyl amide of N,N-dimethylpropionamide (N,N-DMPA), and 3-methoxy-N,N-dimethyl propionamide (M3-N,N-DMPA), and
(B) optionally, a second component consisting of at least one of an aprotic glycol ether.

2. A three-step process for making a water-based polyurethane dispersion (PUD), the process comprising the steps of:
(1) forming a prepolymer with acid group by contacting:
(i) a di-isocyanate,
(ii) a polyol containing an acid group,
(iii) a polyol without an acid group, and
(iv) a metal salt catalyst,

the contacting conducted under reaction conditions and in a solvent consisting essentially of:
(A) a first component consisting of at least one dialkyl amide, and (B) a second component consisting of at least one of an aprotic glycol ether of propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol diacetate, ethylene glycol n-butyl ether acetate, diethylene glycol n-butyl ether acetate, and dipropylene glycol dimethyl ether;
(2) neutralizing the acid group of the prepolymer and any residual di-isocyanate with a base; and
(3) dispersing the neutralized prepolymer in water.

3. The process of claim 1 in which the acid group is a carboxyl group.

4. The process of claim 1 in which the polyol containing an acid group is 2,2-dimethylolpropionic acid.

5. The process of claim 1 in which the metal salt catalyst is an organic tin salt catalyst.

6. A process for making a prepolymer comprising an acid group, the process comprising
contacting
(i) a di-isocyanate,
(ii) a polyol containing an acid group,
(iii) a polyol without an acid group, and
(iv) a metal salt catalyst,

the contacting conducted under reaction conditions and in a solvent consisting essentially of
(A) a first component consisting of at least one dialkyl amide, and
(B) a second component consisting of at least one of an aprotic glycol ether, propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol diacetate, ethylene glycol n-butyl ether acetate, diethylene glycol n-butyl ether acetate, and dipropylene glycol dimethyl ether.

7. The process of claim 1 wherein the first component is N,N-DMPA.

8. The process of claim 1 wherein the first component is M3-N,N-DMPA.

9. The process of claim 1 in which the optional second component is present and is at least one of propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol diacetate, ethylene glycol n-butyl ether acetate, diethylene glycol n-butyl ether acetate, and dipropylene glycol dimethyl ether.

Assignees

• Dow Global Technologies Llc

Inventors

• Ji Jing
• Donate Felipe A
• Jiang Xin
• Shen Cheng
• Hasegawa Kazuyuki
• Crosthwaite Jacob
• Wachowicz Rebecca J

Classifications

• C08G18/44

  Polycarbonates · CPC title

• C08G18/751

  containing only one cycloaliphatic ring · CPC title

• C08G18/348

  Hydroxycarboxylic acids · CPC title

• C08G18/12

  using two or more compounds having active hydrogen in the first polymerisation step · CPC title

• C08G18/69

  Polymers of conjugated dienes {(hydrogenated polymers of conjugated dienes C08G18/6208)} · CPC title