| 摘要 |
There is described a thermosetting and/or radiation curable powder with a binder prepared from a polyester (PE) obtained from a polyol with lower amounts of neopentyl glycol (NPG). The powder forms smooth defect free coats and is resistant to contamination from conventional NPG-rich PE. The powder comprises a binder of a co-reactable blend of (i) 40 - 96 % by weight (w/w) at least one OH, COOH or ethylenically functional (fn) PE having acid or OH number 10 - 100 mg KOH/g, Tg > 40°C, where the PE is obtained reacting polyacid comprising 70 - 100 % weight of terephthalic acid (TPA) and/or isophthalic acid (IPA) and 0 - 30 % w/w another polyacid; with a polyol comprising 0 - 80 % w/w NPG and 20 - 100 % w/w another polyhydric polyol. (ii) 3 - 60 % w/w at least one glycidyl or isocyanate fn polyphenoxy resin; polyepoxy and/or ²-hydroxyalkylamide crosslinker or ethylenically functional oligomer ; and (iii) 0.5 - 5 % w/w of at least one COOH or OH fn acrylic copolymer with a value of 10 - 100 mg KOH/g; Tg > 40°C and a number average molecular weight (M n ) 1000 - 15000 and/or at least one glycidyl or isocyanate fn acrylic copolymer having an fn equivalent weight of from 150 to 1000 g of acrylic copolymer per equivalent of fn group, T g > 40°C and M n 1000 to 15000 and/or a non functional acrylic copolymer having Tg > 40°C and M n 1000 to 15000. |
