Patent ID: 6322900
Filing Date: 2001-11-27
Classification: C08G,C08L,C09D,Y10T

Abstract:
A process for preparing a powder coating for the coating of packaging containers, which comprises milling at least one polyurethane having a Shore A hardness of from 70 to 95 and a Shore D hardness of from 54 to 80, wherein:a) the resulting powder coating has a particle-size distribution such that:i) at least 90 percent by mass of the powder-coating particles have a size of between 1 and 120 .mu.m,ii) the maximum size of the powder-coating particles is not greater than 150 .mu.m for at least 99 percent by mass of the particles, andiii) the mean size of the powder-coating particles is between 1 and 60 .mu.m; andb) the resulting powder coating comprises:i) from 65 to 80% by weight, based on the overall weight of the powder coating, of a thermoplastic component, said thermoplastic component comprises at least one thermoplastic material selected from the group consisting of polyurethanes, polyamides and polyethylenes,ii) optionally, less than 15% by weight, based on the overall weight of the powder coating, of at least one thermoset resin, andiii) optionally, less than 15% by weight, based on the overall weight of the powder coating, of at least one compound selected from the group consisting of pigments, fillers, catalysts, degassing agents, leveling agents, free-radical scavengers, antioxidants, and mixture thereof.