Forming or coating material and utilization thereof
View Patent ↗Molding or coating materials, in particular coating substances for producing self-cleaning moldings or coatings, for example on facades and other building elements, which if they are exposed to rain or moving water from time to time, clean themselves and prevent permanent settlement of dirt particles and pollutants. In accordance with the invention that object is attained with molding or coating materials having the features set forth in the opening part of this specification, which are characterized in that the filler contained has an at least bimodal particle size distribution, wherein the one particle size range (A) has a mean particle diameter of at least 5 μm and the other particle size range (B) has a mean particle diameter of at most 3 μm and the weight ratio of the particles of the former particle size range (A) to the particles of the latter particle size range (B) is between 0.01:1 and 12:1 and the constituents of the dispersion arc so selected in respect of their hydrophilic properties that the static initial contact angle after 3 min equilibration is greater than 130°.
1. A material comprising a dispersion of between 0.2 and 20% of a first hydrophobic binding agent by weight of solids selected from the group consisting of resin, resin precursor, wax and mixtures thereof; between 0.5 and 40% by weight of solids of at least one additional curing binding agent; and a filler wherein the filler has an at least bimodal particle size distribution, wherein one particle size range (A) has a mean particle diameter of at least 5 μm and the other particle size range (B) has a mean particle diameter of at most 3 μm and the weight ratio of the particle size range (A) to the particles of the particle size range (B) is between 0.01:1 and 12:1; said dispersion containing insufficient hydrophilic components so that the static initial water contact angle of a coating formed from the dispersion after 3 minutes equilibrium is greater than 130°.
2. A material as set forth in claim 1 wherein it has a maximum water absorption of less than 10% by weight.
3. A material as set forth in claim 1 wherein it has a maximum water absorption of less than 5% by weight.
4. A material as set forth in claim 1 wherein it has a maximum water absorption of less than 2% by weight.
5. A material as set forth in claim 1 wherein the particles of particle size range (A) have a mean diameter in the range of between about 5 and about 100 μm.
6. A material as set forth in claim 1 wherein the particles of particle size range (A) have a mean diameter in the range of between about 8 and about 60 μm.
7. A material as set forth in claim 1 wherein the particles of particle size range (A) have a mean diameter in the range of between about 10 and about 40 μm.
8. A material as set forth in claim 5 wherein the particles of particle size range (B) have a mean particle diameter of at most 1 μm.
9. A material as set forth in claim 6 wherein the particles of particle size range (B) have a mean particle diameter of at most 1 μm.
10. A material as set forth in claim 5 wherein the particles of particle size range (B) have a mean particle diameter of from between 0.1 and 0.8 μm.
11. A material as set forth in claim 1 wherein the weight ratio of the particles of particle size range (A) to the particles of particle size range (B) is between 0.3:1 and 10:1.
12. A material as set forth in claim 3 wherein the weight ratio of the particles of particle size range (A) to the particles of particle size range (B) is between 0.3:1 and 10:1.
13. A material as set forth in claim 7 wherein the weight ratio of the particles of particle size range (A) to the particles of particle size range (B) is between 0.3:1 and 10:1.
14. A material as set forth in claim 1 wherein the weight ratio of the particles of particle size range (A) to the particles of particle size range (B) is between 0.3:1 and 10:1; preferably in the range of between 1.0:1 and 2.5:1.
15. A material as set forth in claim 1 wherein the binding agent contains between about 1.5 and about 30 percent of additional curing binding agent by weight of solids.
16. A material as set forth in claim 1 wherein the binding agent contains between about 1 and about 15 percent of silicone resin by weight of solids in the coating substance.
17. A material as set forth in claim 3 wherein the binding agent contains between about 1 and about 15 percent of silicone resin by weight of solids in the coating substance.
18. A material as set forth in claim 6 wherein the binding agent contains between about 1 and about 15 percent of silicone resin by weight of solids in the coating substance.
19. A material as set forth in claim 1 wherein the filler contained therein contains at least two different inorganic substances of which one forms the particles of the particle size range (A) and the other forms the particles of the particle size range (B).
20. A molding or coating material as set forth in claim 19 wherein the particles of the particle size range (A) comprise cristobalite and the particles of the particle size range (B) comprise titanium dioxide.
21. A material as set forth in claim 1 wherein it contains an additive selected from the group consisting of thickeners, wetting agents, organic fiber material, inorganic fiber materials, anti-foaming agent and mixtures thereof.
22. A method for coating a surface comprising applying the material of claim 1 to the surface.
23. A method for coating a surface comprising applying the material of claim 2 to the surface.
24. A method for coating a surface comprising applying the material of claim 3 to the surface.
25. A method for coating a surface comprising applying the material of claim 6 to the surface.
26. A method for coating a surface comprising applying the material of claim 15 to the surface.
27. A method for coating a surface comprising applying the material of claim 19 to the surface.
28. A method for coating a surface comprising applying the material of claim 20 to the surface.
29. The material of claim 1 where the curing binding agent is selected from the group consisting of alkyd resins, polyvinyl chloride, chlorine rubber, polyurethanes, and epoxy resins.