| 摘要 |
A coating composition comprises an unsaturated polyester resin, a monomeric unsaturated compound having a terminal =CH2 group, a peroxidic catalyst, an accelerator which is a cobalt compound and one or more hydroxycarboxylic acids. 0.7 to 7.0 mg. of hydroxycarboxylic acid are added per 1 m.g. of cobalt (calculated as metal). Hydroxycarboxylic acids mentioned are tartronic, malic, tartaric, citric and lactic, and they are preferably added in solution, e.g. ethanol, to the unsaturated polyester-monomer mixture, but they can also be added to the molten unsaturated polyester before it is dissolved in the monomer. In the examples the unsaturated polyesters are formed from (a) maleic and phthalic anhydrides and propane-1,2-diol and (b) fumaric acid, phthalic anhydride, ethanediol, propane-1,2-diol, and pentaerythritol triallyl ether, and the comonomer is styrene. |
