| abstract |
The present invention pertains to a powder coating material comprising particles having a particle size distribution which satisfies the following equation: [d(s,90)/d(s,10)]2 ÷ [d(s,90)-7] ≤ 3.5 and in which d(s,90) is greater than 7 μm, d(s,90) and d(s,10) being measured in microns. The powder coatings can be obtained via a grinding-classification process or an agglomeration process. In a preferred embodiment the particles are prepared by a process which comprises mechanical fusion of a powder coating material, wherein the powder is brought to a maximum temperature in the range of from the Tg of the powder to 150C above the Tg, at a heating rate for at least the last 30C, preferably at least the last 40C, up to the maximum temperature of no more than 40C per minute, and after a period in the range of from 0 to 40 minutes at the maximum temperature the powder is cooled. |