| 摘要 |
<p>Electrodeposition compsns. for cathodic deposition are based on a mixt. of (a) 98-50 wt.%, esp. 95-60 wt.% of a self cross linking cationic resin with >=0.5, pref. 0.8-1.5 basic N atoms per 1000 mol. wt. units and a double bond value (number of terminal and pendant C=C bonds per 1000 mol. wt. units) of 0.5, pref. 0.8-2.5, which can be diluted with water after partial or complete neutralisation with an (in)organic acid; and (b) 2-50 esp. 5-40 wt.% of a non-water soluble self-crosslinking polycondens. polymerisation or polyaddn. resin with a double bond value of 0.8, pref. 1-4. The resin mixt. is opt. mixed with pigments, fillers and other known additives, the basic gps. are partially or completely neutralised with an (in)organic acid, and the prod. is diluted with water to form the electrodeposition bath. The prods. give stable electrodeposition baths which can be used for cathodic deposition of coating films having excellent flow properties and adhesion, tog. to untreated steel sheets. The coatings are self-crosslinking and cure on baking e.g. at 130-200 degrees C, esp. 150-180 degrees C for 5-30 mins. esp. 10-25 mins. to give hard films with excellent corrosion resistance.</p> |
