Methods for admixing compressed fluids with solvent-borne compositions comprising solid polymers
AssigneeUnion Carbide Chemicals & Plastics Technology Corporation
InventorsKenneth A. Nielsen, Jeffrey J. Lear, John N. Argyropoulos, Alex Chia-Huei Kuo
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Abstract
Methods are presented by which compressed fluids such as carbon dioxide, nitrous oxide, and ethane can be admixed with solvent-borne compositions that contain a high concentration of solid polymer, such as coating compositions, whereby precipitation of the solid polymer can be avoided, thereby preventing plugging of the mixing apparatus.
Claims24
In a method for pressurizing, proportioning, admixing, and forming an admixture of (i) a solvent-borne composition containing a high concentration of at least one solid polymer capable of being sprayed as a liquid solution and (ii) at least one compressed fluid as a viscosity reducing diluent, in at least an amount which when added to (i) is sufficient to render the viscosity of said admixture to a point suitable for being transportable, said compressed fluid being a gas at standard conditions of 0.degree. Celsius temperature and one atmosphere pressure (STP), the improvement which comprises:
- admixing the solvent-borne composition and the at least one compressed fluid together at pressure P, with the at least one compressed fluid having feed temperature T.sub.1, such that the at least one compressed fluid, at pressure P and temperature T.sub.1, is substantially a gas or a supercritical fluid and has a solubility parameter of about 0.5 to about 4 (cal/cc).sup.1/2, thereby substantially avoiding undesirable precipitation of said solid polymer and consequential plugging of the apparatus.
In a method for pressurizing, proportioning, admixing, and forming an admixture of (i) a solvent-borne composition containing a high concentration of at least one solid polymer capable of being sprayed as a liquid solution and (ii) at least one compressed fluid as a viscosity reducing diluent, in at least an amount which when added to (i) is sufficient to render the viscosity of said admixture to a point suitable for being transportable, said compressed fluid being a gas at standard conditions of 0.degree. Celsius temperature and one atmosphere pressure (STP), the improvement which comprises:
- (1) forming a precursor admixture by admixing the solvent-borne composition with a recycled admixture of solvent-borne composition and at least one compressed fluid;
- and
- (2) admixing the precursor admixture and the at least one compressed fluid together at pressure P, with the at least one compressed fluid having feed temperature T.sub.1, such that the at least one compressed fluid, at pressure P and temperature T.sub.1, is substantially a gas or a supercritical fluid and has a solubility parameter of about 0.5 to about 4 (cal/cc).sup.1/2, thereby substantially avoiding undesirable precipitation of said solid polymer and consequential plugging of the apparatus.
Dependencies are inferred from the claim text.