O.S(=O)(=O)(O)O.[Si:7]([O:17]CC)([O:14]CC)([O:11]CC)[O:8][CH2:9][CH3:10].[CH3:20][Si:21]([O:28][CH2:29][CH3:30])([O:25][CH2:26][CH3:27])[O:22][CH2:23][CH3:24]>C(O)C.C(O)(C)C>[Si:7]([O-:17])([O-:14])([O-:11])[O:8][CH2:9][CH3:10].[CH3:20][Si:21]([O:22][CH2:23][CH3:24])([O:28][CH2:29][CH3:30])[O:25][CH2:26][CH3:27]A sample of 90% hydrolyzed ethyl silicate/methyltriethoxy silane co-condensate was prepared by adding water (11 grams) containing a trace of sulfuric acid to a solution of tetraethyl orthosilicate (37.5 grams) and methyl triethoxy silane (37.5 grams) in anhydrous ethanol (75 grams). Ethocel (4.5 grams) was added to thicken the solution. To a portion (11.5 grams) of the solution was added a 60% total solids TiO2 dispersion in isopropanol (40.3 grams) and a dispersing aid, Nuosperse 657 (3.5 grams). A 2 mil dry coating was prepared on a three by six inch steel Q panel and conditioned for 15 minutes at 200° C. The coated panel was then placed in a muffle furnace at 510° C. and its condition checked after 1, 2, 3, and 4 hours. At all times, the coating remained white, uncracked and adhered to the substrate. In comparison with the results contained in Control B and Examples 1-9, this demonstrates the usefulness of the highly filled co-condensate in this elevated temperature application.
Wird geladen…
