Precursor coating compositions suitable for spraying with supercritical fluids as diluents
AssigneeUnion Carbide Chemicals & Plastics Technology Corporation
InventorsKenneth A. Nielsen, Charles W. Glancy
Life of this patent
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Abstract
The present invention relates to precursor coating compositions which are particularly suitable for being admixed with at least one supercritical fluid used as a viscosity reduction diluent and then spraying this resultant liquid mixture of supercritical fluid and precursor coating composition onto a substrate to be coated.
Claims32
A precursor coating composition suitable for admixture with at least one supercritical fluid which admixture is then to be sprayed comprising a liquid mixture of:
- (a) a solids fraction containing at least one polymeric compound capable of forming a coating on a substrate;
- and
- (b) a solvent fraction containing at least one solvent in which said as least one polymeric compound is at least partially soluble, said solvent fraction having a composition containing a weight % solvent distribution and relative evaporation rates of:
- ______________________________________ Wt % of Total Solvent Fraction RER ______________________________________ 30-100% <50 0-70% 50-100 0-40% 101-250 <10% >250;
- ______________________________________
- said liquid mixture having:
- (i) a viscosity of less than about 6000 centipoise and having less than about 400 grams of solvent fraction per liter of mixture;
- (ii) a solubility with at least one supercritical fluid, above the critical temperature and pressure of the supercritical fluid, of greater than 5% by weight of supercritical fluid in said mixture;
- (iii) a viscosity of less than about 300 centipoise when admixed with a sufficient amount of the at least one supercritical fluid, above the critical temperature and pressure of the supercritical fluid, so as to render the mixture suitable for spray application;
- and
- (iv) a solubility with the supercritical fluid in the non-supercritical state, at 25.degree. C. and one atmosphere absolute pressure of said fluid, of less than about 0.8% by weight of fluid in said mixture.
A precursor coating composition suitable for admixture with supercritical carbon dioxide which admixture is then to be sprayed comprising a liquid mixture of:
- (a) a solids fraction containing at least one polymeric compound capable of forming a coating on a substrate;
- and
- (b) a solvent fraction containing at least one solvent in which said at least one polymeric compound is at least partially soluble, said solvent fraction having a composition containing a weight % solvent distribution and relative evaporation rates of:
- ______________________________________ Wt % of Total Solvent Fraction RER ______________________________________ 30-100% <50 0-70% 50-100 0-40% 101-250 <10% >250;
- ______________________________________
- (i) a viscosity of less than about 6000 centipoise and having less than about 400 grams of solvent fraction per liter of mixture;
- (ii) a solubility with supercritical carbon dioxide, above the critical temperature and pressure of the supercritical carbon dioxide, of greater than 5% by weight of supercritical carbon dioxide in said mixture;
- (iii) a viscosity of less than about 300 centipoise when admixed with a sufficient amount of the at least one supercritical carbon dioxide, above the critical temperature and pressure of the supercritical carbon dioxide, so as to render the mixture suitable for spray application;
- and
- (iv) a solubility with the carbon dioxide in its non-supercritical state, at 25.degree. C. and one atmosphere absolute pressure of carbon dioxide, of less than about 0.8% by weight of carbon dioxide in said mixture.
Dependencies are inferred from the claim text.