| 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) 40-98% by weight (w/w) at least one OH, COOH or ethylenically functional (fn) PE having acid or OH number 10-100 mg KOH/g, T9>40° C., where the PE is obtained from reacting a 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 0-85% w/w NPG and 15-100% w/w another polyhydric polyol; (ii) 2-60% w/w at least one glycidyl or isocyanate fn polyphenoxy resin; polyepoxy and/or &bgr;-hydroxyalkylamide crosslinker or ethylenically functional oligomer; and (iii) 0.2-5 % w/w of at least one COOH or OH fn acrylic copolymer with a value of 10-100 mg KOH/g; T9>400 C and a number average molecular weight (Mn) 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, T9>40° C. and Mn 1000 to 15000 and/or a non functional acrylic copolymer having Tg>400 C and Mn 1000 to 15000. |
