Supercritical fluids as diluents in liquid spray application of coatings
AssigneeUnion Carbide Chemicals and Plastics Company Inc.
InventorsChinsoo Lee, Kenneth L. Hoy, Marc D. Donohue
Life of this patent
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Abstract
A liquid coatings application process and apparatus is provided in which supercritical fluids, such as supercritical carbon dioxide fluid, are used to reduce to application consistency viscous coatings compositions to allow for their application as liquid sprays.
Claims55
A process for the liquid spray application of coatings to a substrate, which comprises:
- (1) forming a liquid mixture in a closed system, said liquid mixture comprising:
- (a) a coating formulation comprising at least one liquid polymeric compound capable of forming a coating on a substrate;
- and
- (b) at least one supercritical fluid, in at least an amount which when added to (a) is sufficient to render the vicosity of said mixture to a point suitable for spray application;
- and
- (2) spraying said liquid mixture, forming droplets having an average diameter of 1 micron or greater, onto a substrate to form a liquid coating thereon having substantially the composition of the said coating formulation.
A process for the liquid spray application of coatings to a substrate, which comprises:
- (1) forming a liquid mixture in a closed system, said liquid mixture comprising:
- (a) at least one polymeric compound capable of forming a coating on a substrate;
- (b) at least one supercritical fluid, in at least an amount which when added to (a) and (c) is sufficient to render the vicosity of said mixture to a point suitable for spray application;
- and
- (c) at least one active solvent in which said polymeric compound is soluble and which is at least partially miscible with the supercritical fluid (b), said solvent being present in an amount such that the vicosity of (a) and (c) is greater than that desirable for liquid spray applications;
- and
- (2) spraying said liquid mixture, forming droplets having an average diameter of 1 micron or greater, onto a substrate to form a liquid coating thereon.
A process for the liquid spray application of coatings to a substrate, which comprises:
- (1) forming a liquid mixture in a closed system of:
- (a) at least one polymeric compound capable of forming a coating on a substrate;
- (b) at least one supercritical fluid carbon dioxide, in at least an amount which when added to (a) and (c) is sufficient to render the vicosity of said mixture to a point suitable for spray application;
- and
- (c) one active solvent in which said polymeric compound is soluble and which is at least partially miscible with the supercritical fluid carbon dioxide, said solvent being present in an amount such that the vicosity of (a) and (c) is greater than that desirable for liquid spray applications;
- and
- (2) spraying said liquid mixture, forming droplets having an average diameter of 1 micron or greater, onto a substrate to form a liquid coating thereon.
A process for the liquid spray application of coatings to a substrate wherein the use of enviornmentally undesirable organic solvents is minimized, which comprises:
- (1) forming a liquid mixture in a closed system of:
- (a) at least one polymeric compound capable of forming a coating on a substrate said polymeric compound being present in an amount ranging from about 5 to about 65 wt. % based upon the total weight of (a), (b) and (c);
- (b) supercritical carbon dioxide fluid, in at least an amount which when added to (a) and (c) is sufficient to render the vicosity of said mixture of (a), (b) and (c) to a point ranging from about 10 to about 100 cps.;
- and
- (c) at least one active solvent in which said polymeric compound is soluble and which is at least partially miscible with the supercritical carbon dioxide fluid, said solvent being present in an amount up to about 70 wt. % based upon the total weight of (a), (b) and (c) such that the vicosity of (a) and (c) has a vicosity greater than about 150 cps,;
- and
- (2) spraying said liquid mixture, forming droplets having an average diameter of 1 micron or greater, onto a substrate to form a liquid coating thereon.
Dependencies are inferred from the claim text.