Non-hazardous water-based polyurethane dispersion

Patent metadata

Field	Value
Publication number	US-2018371261-A1
Application number	US-201615776539-A
Country	US
Kind code	A1
Filing date	Dec 21, 2016
Priority date	Dec 22, 2015
Publication date	Dec 27, 2018
Grant date	—

Abstract

A water-based polyurethane dispersion including a chain-extended polyurethane, characterized in that the polyurethane dispersion includes 2,5,7,10-tetraoxaundecane. The water-based polyurethane dispersion is suitable as a non-hazardous water-based coating composition for coatings with a particularly good adhesion on plastic or rubber substrates. The solvent 2,5,7,10-tetraoxaundecane contained therein imparts good film coalescing, good adhesive properties and high strength of the polyurethane dispersion.

First claim

1 . A water-based polyurethane dispersion comprising a chain-extended polyurethane, wherein the polyurethane dispersion comprises 2,5,7,10-tetraoxaundecane.

2 . The water-based polyurethane dispersion according to claim 1 , wherein the chain-extended polyurethane has ionic groups or contains polyethylene oxide units.

3 . The water-based polyurethane dispersion according to claim 1 , comprising 3 to 60% by weight of 2,5,7,10-tetraoxaundecane based on the total weight of the chain-extended polyurethane in the water-based polyurethane dispersion.

4 . The water-based polyurethane dispersion according to claim 1 , comprising 45 to 80% by weight of water.

5 . The water-based polyurethane dispersion according to claim 1 , wherein the chain-extended polyurethane is a reaction product of an isocyanate-terminated polyurethane prepolymer and at least one polyamine as chain extender.

6 . The water-based polyurethane dispersion according to claim 5 , wherein the isocyanate-terminated polyurethane prepolymer is a reaction product of
at least one first polyol, at least one second polyol, which is different from the first polyol, and at least one diisocyanate, wherein the at least one second polyol is selected from a polyether polyol having ethylene oxide units, a polyol having an acid group and a polyol having an amine group.

7 . The water-based polyurethane dispersion according to claim 1 , wherein the water-based polyurethane dispersion is an anionic or non-ionic polyurethane dispersion.

8 . A process for producing the water-based polyurethane dispersion according to claim 1 , comprising the steps of
a) reacting at least one first polyol, at least one second polyol and at least one diisocyanate in the presence of 2,5,7,10-tetraoxaundecane and optionally a catalyst to form an isocyanate-terminated polyurethane prepolymer, b) optionally at least partly neutralizing the isocyanate-terminated polyurethane prepolymer to obtain a neutralized isocyanate-terminated polyurethane prepolymer, and c) dispersing the optionally neutralized prepolymer in water and adding a chain extender to obtain the water-based polyurethane dispersion comprising the chain-extended polyurethane and 2,5,7,10-tetraoxaundecane.

9 . The process according to claim 8 , wherein the at least one second polyol has carboxyl groups and/or the at least one diisocyanate is an aliphatic diisocyanate.

10 . The process according to claim 9 , wherein the base to neutralize the carboxyl groups is a tertiary amine.

11 . The water-based polyurethane dispersion according to claim 1 , obtainable by a process for producing the water-based polyurethane dispersion, comprising the steps of
a) reacting at least one first polyol, at least one second polyol and at least one diisocyanate in the presence of 2,5,7,10-tetraoxaundecane and optionally a catalyst to form an isocyanate-terminated polyurethane prepolymer, b) optionally at least partly neutralizing the isocyanate-terminated polyurethane prepolymer to obtain a neutralized isocyanate-terminated polyurethane prepolymer, and c) dispersing the optionally neutralized prepolymer in water and adding a chain extender to obtain the water-based polyurethane dispersion comprising the chain-extended polyurethane and 2,5,7,10-tetraoxaundecane.

12 . Coating composition comprising the water-based polyurethane dispersion according to claim 1 at least one further ingredient selected from other polymer dispersions, fillers, pigments, other solvents, stabilizers, defoamers, surfactants, rheological additives, thickening agents and antioxidants.

13 . A method comprising applying the coating composition according to claim 12 or of the water-based polyurethane dispersion comprising a chain-extended polyurethane, wherein the polyurethane dispersion comprises 2,5,7,10-tetraoxaundecane, for coating a plastic substrate or a rubber substrate.

14 . A process for coating a plastic substrate or a rubber substrate, comprising applying the coating composition according to claim 12 or the water-based polyurethane dispersion comprising a chain-extended polyurethane, wherein the polyurethane dispersion comprises 2,5,7,10-tetraoxaundecane, on the substrate and hardening the applied coating.

15 . Coated article obtained by the process according to claim 14 .

16 . A method comprising applying 2,5,7,10-tetraoxaundecane as coalescent for water-based polyurethane dispersions.

Assignees

• Sika Tech Ag

Inventors

• Evans Craig
• Carter Neil
• Martin Ian

Classifications

• C08G18/44

  Polycarbonates · CPC title

• C08G18/758

  containing two or more cycloaliphatic rings · CPC title

• C08G18/0823

  containing carboxylate salt groups or groups forming them · CPC title

• C08G18/0866

  the dispersing or dispersed phase being an aqueous medium · CPC title

• C08G18/3228

  acyclic · CPC title