A powder coating composition comprising an intimate blend in a finely divided form of:
(a) from about 60 to 70 percent by weight of a polymeric binder including a mixture of an epoxy, polyester, blocked urethane, or an acrylic resin;
(b) from about 30 to 40 percent by weight of a co-reactant capable of reacting with the reactive functionality on said polymeric binder (a) selected from the group consisting of blocked aliphatic diisocyanates, blocked aromatic diisocyanates, acid anhydrides, triglycidyl isocyanurate, dicyandiamide and its derivatives and mixtures thereof;
(c) from about 0 to 2 percent by weight of a degasser; and
(d) from about 0.2 to 5 percent by weight of a hyperbranched polyester as a flow and levelling agent or as an adhesion promotor;
wherein said hyperbranched polyester has a number average molecular weight of at least 1200 and a glass transition temperature (Tg) of from about 35°C to about 170°C.
一种粉末涂料组合物,由以下物质以细粒形式紧密混合而成:
(a) 约 60%至 70%(按重量计)的聚合物粘结剂,包括环氧
树脂、聚酯、嵌段聚
氨酯或
丙烯酸树脂的混合物;
(b) 约 30%至 40%(按重量计)能与所述聚合物粘合剂(a)上的反应官能团发生 反应的共反应物,该共反应物选自由封端脂肪族二
异氰酸酯、封端芳香族二异
氰酸酯、酸酐、异
氰尿酸三
缩水甘油酯、双
氰二酰胺及其衍
生物和它们的混 合物组成的组;
(c) 以重量计约 0%至 2%的脱气剂;及
(d) 以重量计约 0.2%至 5%的超支化聚酯,作为流动剂和流平剂或粘合
促进剂;
其中所述超支化聚酯的平均分子量至少为 1200,
玻璃化温度 (Tg) 约为 35°C 至 170°C。