| 摘要 |
Emulsifier-free thermocurable coating (I) in the form of an aq. emulsion comprises (A) 38.5-80 wt. % one or several self-emulsifying copolymers based on esters of unstd. carboxylic acids with hydrophobic and hydrophilic portions, partially or completely neutralised with bases in which (a) the hydrophobic portion are based on monomeric esters of unsatd. carboxylic acids with secondary OH-gps. which can occur in a mixt. with OH-gp.-free comonomers and; (b) the hydrophilic portion are based on monomeric esters of unsatd. carboxylic acids with primary OH-gps. and monomeric esters of unsatd. carboxylic acids with COOH-gps. which can occur in a mixt. with OH-gp.-free comonomers; where the number ratio of primary to secondary OH-gps. in the copolymer is 1:1.5-1:2.5 and the copolymer has an acid number of 15-60mg KOH/g, OH-number of 60-200mg KOH/g and number average mwt. (mn) of 2000-10000; (B) 3.5-25.5 wt. % one or several polyester oligomers with a calculated mwt. of 200-1000, hydroxy number of 280-600 and acid number 0-1.5; (c) 3.5-28 wt. % one or several water-insoluble amine resin crosslinking agents; (D) 0-4 wt. % one or several water-soluble amine resin crosslinking agents; and (E) 0.5-28 wt. % one or several capped polyisocyanates; in which the sum of the wt. % of (A)-(E) is 100 wt. %. (I) also contains water and opt. one or several organic solvents, pigments, fillers and/or lacquer additives. Also claimed is the prepn. of (I) comprising mixing (A), (B) and (E), neutralising the copolymer with base, adding (C) and (D), and emulsifying in water. |
