Waterborne, UV curable coating composition for easy-clean coatings

Patent metadata

Field	Value
Publication number	US-12312490-B2
Application number	US-202017768542-A
Country	US
Kind code	B2
Filing date	Oct 13, 2020
Priority date	Oct 15, 2019
Publication date	May 27, 2025
Grant date	May 27, 2025

Abstract

The invention relates to the synthesis of a carboxyl-functional, unsaturated polyurethane containing a perfluoropolyether block, which can be used as an easy clean additive in preparation of a waterborne, UV curable coating composition. The polyurethane can be prepared by a method comprising the following steps: a) subjecting a hydroxy-terminated perfluoropolyether A to a reaction with a molar excess of polyisocyanate B to obtain an isocyanate-functional urethane C, b) adding a carboxyl-functional polyol D to the reaction mixture, c) adding OH— functional (meth)acrylate monomer E to the reaction mixture, wherein steps (b) and (c) can be performed in any order, and d) neutralizing the reaction product with a neutralizer F. The resulting coating has easy clean and anti-stain properties.

First claim

The invention claimed is:

1. A waterborne, UV curable coating composition, comprising an aqueous dispersion of a polyurethane and at least one non-fluorinated polymer different from the polyurethane, wherein the polyurethane is present as an additive in an amount 0.1-5 wt. % based on resin solids of the coating composition, and wherein the polyurethane is a carboxyl-functional, unsaturated polyurethane containing a perfluoropolyether block, said polyurethane having a molecular weight Mn in the range from 1,000 to 5,000 determined by gel permeation chromatography with a polystyrene standard and tetrahydrofuran as the mobile phase, said polyurethane prepared by a method comprising the following steps:
a) subjecting a hydroxy-terminated perfluoropolyether A to a reaction with a molar excess of polyisocyanate B to obtain an isocyanate-functional urethane,
b) subjecting the isocyanate-functional urethane to a reaction with a carboxyl-functional polyol D to obtain an isocyanate-functional polymer,
c) subjecting the isocyanate-functional polymer obtained in step b) to a reaction with a mono-OH-functional (meth)acrylate monomer E,
d) neutralizing the reaction product of step c) with a neutralizer G to obtain a neutralized polyurethane,
e) dispersing the neutralized polyurethane obtained in step d) in water;
and wherein the method does not include chain extension with a diamine or a diol after dispersing the neutralized polyurethane in water.

2. The coating composition according to claim 1 , wherein compound A has a general structure
HO—(CH 2 CH 2 O) p —CH 2 —CF 2 —R f —CF 2 —CH 2 —(OCH 2 CH 2 ) q —OH

wherein p and q are integers independently chosen from 0 to 50, R f represents a bifunctional radical having perfluoropolyether structure (CF 2 CF 2 O) n , (CF 2 O) m or (CF 2 —CF 2 —O) n —(CF 2 —O) m , and wherein n and m are integers independently chosen from 1 to 100.

3. The coating composition according to claim 1 , wherein the carboxyl-functional polyol D is 2,2-dimethylolpropionic acid (DMPA) or 2,2-dimethylolbutanoic acid (DMBA).

4. The coating composition according to claim 1 , wherein the mono-OH-functional (meth)acrylate monomer E is dipentaerythritol pentaacrylate (DPPA).

5. The coating composition according to claim 1 , wherein the at least one polymer different from the polyurethane is non-fluorinated.

6. The coating composition according to claim 5 , wherein the at least one polymer different from the polyurethane is a poly(meth)acrylate.

7. The coating composition according to claim 1 , further comprising a photoinitiator.

8. The coating composition according to claim 1 , further comprising an organic solvent in an amount less than 10 wt. %, based on the total weight of the coating composition.

9. A method of coating a substrate, comprising applying the coating composition according to claim 1 to a substrate and curing the coating composition by means of UV radiation.

10. A coated substrate obtained according to the method of claim 9 .

11. The coated substrate according to claim 10 , wherein the substrate is selected from the group consisting of polycarbonate acrylonitrile butadiene styrene (PC/ABS), polycarbonate, polyacrylate, polyolefin, polyamide, polystyrene, glass, wood, aluminum, and aluminum alloys.

Assignees

• Akzo Nobel Coatings Int Bv

Inventors

• Shi Zheng
• Huang Quan James
• Fang Puxin
• Lin Hong
• Lu Junbiao

Classifications

• C08G18/6692 Primary

  with compounds of group C08G18/34 · CPC title

• C08G18/5015

  having fluorine atoms · CPC title

• C08G18/348

  Hydroxycarboxylic acids · CPC title

• C08G18/0823

  containing carboxylate salt groups or groups forming them · CPC title

• C09D175/14

  Polyurethanes having carbon-to-carbon unsaturated bonds · CPC title