Polyester containing tertiary carboxyl groups, process for its preparation and thermosetting powder compositions containing it
申请人:——
公开号:US20030148130A1
公开(公告)日:2003-08-07
The invention concerns a polyester bearing tertiary carboxyl groups, characterised in that it consists of: (a) 8.1 to 35 moles of an aliphatic or cycloaliphatic of a polyol; (b) 9.1 to 36 moles of an aliphatic, cycloaliphatic or aromatic polycarboxylic acid; (c) 1.6 to 2.8 moles of an aliphatic, cycloaliphatic or aromatic compound comprising a tertiary carboxyl group and either a primary or secondary carboxyl group, or a primary or secondary hydroxyl group. Said polyester is prepared in several steps, the first steps consisting in the preparation of a polyester by condensation between (a) an aliphatic or cycloaliphatic polyol, and (b) an aliphatic, cycloaliphatic or aromatic polycarboxylic acid, the final step consisting in condensing said polyester with (c) an aliphatic, cycloaliphatic or aromatic compound comprising a tertiary carboxyl group and either a primary or secondary carboxyl group, or a primary or secondary hydroxyl group. Said polyester is used in thermosetting powder compositions, mixed with a crosslinking agent which is more particularly a &bgr;-hydroxylalkylarnide. Said compositions provide coatings with excellent surface appearance, good flexibility and good resistance to poor weather conditions.
本发明涉及一种带有叔羧基的聚酯,其特征在于它包括(a) 8.1 至 35 摩尔的脂肪族或环脂族多元醇; (b) 9.1 至 36 摩尔的脂肪族、环脂族或芳香族多元羧酸; (c) 1.6 至 2.8 摩尔的脂肪族、环脂族或芳香族化合物,该化合物包含一个叔羧基和一个伯或 仲羧基,或一个伯或仲羟基。聚酯的制备分为几个步骤,第一步是通过缩合(a)脂肪族或环脂族多元醇和(b)脂肪族、环脂族或芳香族多羧酸制备聚酯,最后一步是将聚酯与(c)脂肪族、环脂族或芳香族化合物缩合,该化合物包含叔羧基和伯、仲羧基,或伯、仲羟基。所述聚酯用于热固性粉末组合物中,并与交联剂混合,交联剂尤其是羟基烷基酰胺。所述组合物提供的涂层具有极佳的表面外观、良好的柔韧性和良好的耐恶劣气候条件性能。