Two-part polyurethane erosion resistant coatings

• US 10,066,121 B2
• Filed: 04/18/2016
• Issued: 09/04/2018
• Est. Priority Date: 04/24/2015
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Weber, Bjorn, Audenaert, Frans A.
• Primary Examiner(s): Zacharia, Ramsey E
• Application Number:
  US15/568,037
• Publication Number:
  US 20180142122A1
• Time in Patent Office: 869 Days
• CPC Class Codes: B05D 3/108 Curing
• CPC Class Codes: C08G 18/10 Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• CPC Class Codes: C08G 18/12 using two or more compounds having active hydrogen in the first polymerisation step
• CPC Class Codes: C08G 18/3206 aliphatic
• CPC Class Codes: C08G 18/3812 having fluorine atoms
• CPC Class Codes: C08G 18/3857 having nitrogen in addition to sulfur
• CPC Class Codes: C08G 18/3861 containing sulfonamide and/or sulfonylhydrazide groups
• CPC Class Codes: C08G 18/387 in addition to a perfluoroalkyl group
• CPC Class Codes: C08G 18/3872 the sulfur atom belonging to a sulfoxide or sulfone group
• CPC Class Codes: C08G 18/87 by sulfur
• CPC Class Codes: C09D 175/04 Polyurethanes
• CPC Class Codes: F01D 5/288 Protective coatings for blades

Abstract

The present disclosure relates to two-part polyurethane coatings having excellent erosion resistance and comprising a compound having a fluorinated segment. Additionally, these two-part polyurethane coatings can be cured under high relative humidity conditions. The present disclosure also relates to articles coated with those two-part polyurethane coatings and to methods of reducing erosion in an article, among other embodiments.

Claims

1. A wind turbine blade having coated thereon a fluorinated alcohol-containing two-part polyurethane composition comprising:

an isocyanate composition comprising polyisocyanate molecules, each molecule having two or more isocyanate moieties;

wherein from 95% to 100% of the polyisocyanate molecules have two isocyanate moieties each and from 0% to 5% of the polyisocyanate molecules have three or more isocyanate moieties each; and

a hydroxyl composition comprising;

polyol molecules, each molecule having two or more hydroxyl moieties;

wherein from 95% to 100% of the polyol molecules have two hydroxyl moieties each and from 0% to 5% of the polyol molecules have three or more hydroxyl moieties each; and

a fluoroalkyl sulfonamide diol of the formula;

2. The coated wind turbine blade according to claim 1 wherein the two-part composition, when mixed, cured, and made into a free film, forms a polyurethane film having an elongation at break point higher than 300% according to method ASTM D882 10 and measured on a film having a thickness of 300 μ

m to 500 μ

m.

3. The coated wind turbine blade according to claim 1, wherein the fluoroalkyl sulfonamide diol is C₄F₉—

SO₂—

N(CH₂CH₂OH)₂.

4. The coated wind turbine blade according to claim 1, wherein the polyisocyanate molecules are chosen from 1,6 hexamethylene diisocyanate, 2,2,4-trimethyl-1,6-hexamethylenediisocyanate, 1,2-ethylenediisocyanate, dicyclohexylmethane-4,4′

-diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate and their prepolymers.

5. The coated wind turbine blade according to claim 1, wherein the polyol molecules are chosen from propanediol, butanediol, pentanediol, hexanediol, heptanediol, and octanediol.

6. The coated wind turbine blade according to claim 1, wherein the elongation at break point is higher than 300% when the two-part composition is cured at a temperature of 23°

C. and relative humidity of at least 80%.

7. The coated wind turbine blade according to claim 1, further comprising TiO₂ or carbon black particles, or both in the hydroxyl composition.

8. The coated wind turbine blade according to claim 1, further comprising one or more UV stabilizers chosen from zinc oxides, hydroxyphenyl triazines, hydroxyphenyl benzotriazoles and hydroxy benzophenones in the hydroxyl composition.

9. The coated wind turbine blade according to claim 1, wherein the two-part composition, when mixed, cured, and made into a free film, forms a polyurethane film having a tear resistance from 35 N/mm to 75 N/mm, measured according to DIN ISO 34-1 (Jan. 7, 2005), method A (Trouser specimen).

10. The coated wind turbine blade according to claim 1, wherein the two-part composition, when mixed, cured, and made into a free film, forms a polyurethane film having a tensile strength at break from 16 MPa to 35 MPa, measured according to ASTM D882-10.

11. A method of reducing erosion of a wind turbine blade comprising:

providing the two-part composition of claim 1,

mixing the two-part composition,

coating the wind turbine blade with the two-part composition, and

curing the coating.