Method for producing coating powders catalysts and drier water-borne coatings by spraying compositions with compressed fluids

A process for forming a coating-powder which comprises:

• (1) forming a liquid mixture in a closed system, said liquid mixture comprising:
• (a) a precursor coating-powder composition comprising:
• (i) a solids fraction containing dry ingredients of a coating-powder and which is capable of forming powder by solvent evaporation when sprayed;
• and
• (ii) a solvent fraction which is at least partially miscible with (i) and which is sufficiently volatile to render said precursor coating-powder composition capable of forming powder when sprayed;
• and
• (b) at least one compressed fluid in an amount which when added to (a) renders said liquid mixture capable of forming a substantially decompressive spray, wherein the compressed fluid is a gas at standard conditions of 0.degree. Celsius and one atmosphere pressure (STP);
• and
• (2) spraying said liquid mixture at a temperature and pressure that gives a substantially decompressive spray by passing the mixture through an orifice into an environment suitable for forming coating powder by solvent evaporation.

A process for forming solid particulates which comprises:

• (1) forming a liquid mixture in a closed system, said liquid mixture comprising:
• (a) a water-borne composition comprising:
• (i) a nonvolatile materials fraction which is solid or capable of becoming solid, which is capable of being sprayed, and which is capable of forming solid particulates by evaporation when sprayed;
• and
• (ii) a solvent fraction containing at least water;
• which is sufficiently volatile to render, and contains water in an amount which renders, said water-borne composition capable of forming solid particulates when sprayed;
• and
• (b) at least one compressed fluid which is a supercritical fluid at the temperature and pressure at which said liquid mixture is sprayed and which is substantially present in said liquid mixture as a finely dispersed liquid compressed fluid phase, in an amount which renders said liquid mixture capable of forming a substantially decompressive spray, wherein the compressed fluid is a gas at standard conditions of 0.degree. Celsius and one atmosphere pressure (STP);
• and
• (2) spraying said liquid mixture at a temperature above about 40.degree. Celsius and a pressure that gives a substantially decompressive spray by passing the mixture through an orifice into an environment suitable for forming solid particulates by evaporation.