Ice-resistant paint for wind turbine blades, procedure for its preparation, use and wind turbine blade coated with the ice-resistant paint
Ice-resistant paint comprising an ice-resistant base component that in turn comprises a main component entailing a high solid paint with a synthetic polyurethane-based binding component dissolved in a main organic solvent, and a hydrophobe component consisting of hydrophobic ice-resistant functional nanoparticles selected from among nanoparticles functionalized with a polymer and nanoparticles functionalized in sol-gel, where the ice-resistant paint comprises a mixture of the main component with a dispersion of functional nanoparticles dispersed in a dispersing composition constituting the main solvent and a dispersant, and forms a base matrix, where the dispersing composition and functional nanoparticles form a dispersion of nanoparticles in which the functional nanoparticles are in the base matrix, and the dispersion of dispersing nanoparticles mixed with the main component to form an ice-resistant base component of the ice-resistant paint.
1. An ice-resistant paint produced by a process comprising the steps of:
(a) providing a main component which is a high solids paint component comprising a polyurethane resin and a first portion of a main organic solvent, wherein the high solids paint component has a solids content that is greater than 70% by mass, a density between 1.2-1.4 g/cm 3 and a content of volatile organic compounds (VOC) below 300 g/l, and wherein the main component does not comprise functional nanoparticles
(b) providing a dispersing component comprising a second portion of the main organic solvent, a dispersant and a plurality of nanoparticles that are functionalized so that they are ice-resistant and hydrophobic, said nanoparticles being dispersed in the dispersion and comprising 20-30% by weight in respect of the second portion of the main organic solvent, said dispersant being present in the dispersing component in an amount of 2-3.5% by weight of the nanoparticles; and
(c1) mixing the dispersing component with the high solids paint component to form the ice resistant paint comprising between 4-6% of the nanoparticles, or (c2) mixing the dispersing component with the high solids paint component and with a hardener to form the ice resistant paint comprising about 2-3% by weight of the nanoparticles.
2. The ice-resistant paint according to claim 1 , wherein the main organic solvent is selected from the group consisting of alcohol-based and organic-based solvents.
3. The ice-resistant paint according to claim 2 , wherein the main organic solvent is selected from the group consisting of butyl acetate, ethyl acetate, 1-methoxy-2-propanol acetate, toluene, xylene, naphtha solvent, 1,4-dioxane, diacetone alcohol, N-methylpyrrolidone, dimethylacetamide, dimethylformamide, dimethyl sulfoxide, and combinations thereof.
4. The ice-resistant paint according to claim 3 , wherein the main organic solvent is n-butyl-acetate.
5. The ice-resistant paint according to claim 1 , wherein the dispersant is a polymeric dispersant in non-polar systems.
6. The ice-resistant paint according to claim 1 , wherein
the functional ice-resistant nanoparticles bear hydrophobic groups on their surface and comprise inorganic nanoparticles with hydrophilic groups.
7. The ice-resistant paint according to claim 6 , wherein the hydrophobic groups are selected from the group consisting of:
(a) organofunctional silica compounds having at least one alkyl group with 1 to 50 carbon atoms, and at least one functional group, and
(b) monomeric silicic esters, and oligomeric silicic esters having methoxy, ethoxy, n-propoxy groups, and isopropoxy groups.
8. The ice-resistant paint according to claim 6 , wherein the nanoparticles that are products of the reaction of SiO 2 and an ester selected from the group consisting of dimethyldichlorosilane and hexamethyldisilazane.
9. The ice-resistant paint according to claim 4 , wherein the dispersing component comprises a cationic dispersant that contains a mixture of alkyl esters, fatty acids and alkylamines; and
the nanoparticles are pyrogenic silica nanoparticles functionalized with an ester selected from the group consisting of dimethyldichlorosilane and hexamethyldisilazane.
10. The ice-resistant paint according to claim 1 , wherein the ice-resistant functional nanoparticles have an average particle size of between 100 nm and 300 nm.
11. The ice-resistant paint according to claim 5 , wherein the dispersant is a cationic polymeric dispersant comprising a mixture of alkyl esters, fatty acids, and alkylamines.
12. The ice-resistant paint according to claim 7 , wherein the at least one functional group is selected from the group consisting of dialkyldialkoxysilanes, alkyltrialkoxysilanes, trialkylchlorosilanes, dialkylchlorosilanes, alkylpolysiloxanes, dialkylpolysiloxanes and alkyldisiloxanes.
13. The ice-resistant paint according to claim 7 , wherein the hydrophobic groups are selected from the group consisting of dimethyldichlorosilane, hexamethyldichlorosilane, octyltriethoxysilane, and dimethylpolysiloxane.
14. The ice-resistant paint according to claim 1 , comprising the hardener.
15. The ice-resistant paint according to claim 14 , wherein the hardener comprises a compound selected from the group consisting of an isocyanate, a polyisocyanate and a combination thereof.
16. A method of coating at least one part of a wind turbine blade, comprising the steps of:
(a) providing a main component which is a high solids paint component comprising a polyurethane resin and a first portion of a main organic solvent, wherein the high solids paint component has a solids content that is greater than 70% by mass, a density between 1.2-1.4 g/cm 3 and a content of volatile organic compounds (VOC) below 300 g/1, and wherein the main component does not comprise functional nanoparticles;
(b) providing a dispersing component comprising a second portion of the main organic solvent, a dispersant and a plurality of nanoparticles that are functionalized so that they are ice-resistant and hydrophobic, said nanoparticles being dispersed in the dispersing component, wherein the nanoparticles are present in the dispersing component in an amount of 20-30% by weight in respect of the second portion of the main organic solvent and wherein the dispersant is present in the dispersing component in an amount of 2-3.5% by weight of the nanoparticles;
(c1) mixing the dispersing component with the high solids paint component to form an ice resistant paint comprising between 4-6% by weight of the nanoparticles or
(c2) mixing the dispersing component with the high solids paint component and with a hardener to form the ice resistant paint comprising about 2-3% by weight of the nanoparticles; and
(d) applying the ice resistant paint to the at least one part of the wind turbine blade.
17. The method according to claim 16 , wherein step (c2) is present and the hardener comprises a compound selected from the group consisting of an isocyanate, a polyisocyanate and a combination thereof.
18. A method of making an ice resistant paint, comprising the steps of:
(a) providing a main component which is a high solids paint component comprising a polyurethane resin and a first portion of a main organic solvent, wherein the high solids paint component has a solids content that is greater than 70% by mass, a density between 1.2-1.4 g/cm 3 and a content of volatile organic compounds (VOC) below 300 g/1, and wherein the main component does not comprise functional nanoparticles;
(b) providing a dispersing component comprising a second portion of the main organic solvent, a dispersant and a plurality of nanoparticles that are functionalized so that they are ice-resistant and hydrophobic, said nanoparticles being dispersed in the dispersing component, wherein the nanoparticles are present in the dispersing component in an amount of 20-30% by weight in respect of the second portion of the main organic solvent and wherein the dispersant is present in the dispersing component in an amount of 2-3.5% by weight of the nanoparticles;
(c1) mixing the dispersing component with the high solids paint component to form an ice resistant paint comprising between 4-6% by weight of the nanoparticles or
(c2) mixing the dispersing component with the high solids paint component and with a hardener to form the ice resistant paint comprising about 2-3% by weight of the nanoparticles.