COLOURED POWDER COATING COMPOSITIONS

摘要

PCT No. PCT/GB89/01432 Sec. 371 Date Jul. 25, 1991 Sec. 102(e) Date Jul. 25, 1991 PCT Filed Nov. 30, 1989 PCT Pub. No. WO90/06345 PCT Pub. Date Jun. 14, 1990.A coloured powder coating composition consists of solid particles, each of which comprises a solid polymeric binder system and at least a majority of which contain at least one colouring agent. The composition is a mixture of particles of at least two different colours. The size of the particles is sufficiently low that when the powder coating is applied to a substrate and heated to form a continuous coating the differences in colour in the cured powder coating arising from the different coloured particles cannot be discerned by the human eye. The size of the particles is preferably below 10 microns in the largest dimension. The particles are preferably agglomerated into composite particles of mean particle size 15 to 75 microns for application by electrostatic spray.