| 摘要 |
<p>1509379 Powder coating composition WESTINGHOUSE ELECTRIC CORP 25 April 1975 [8 May 1974] 17229/75 Heading C3B A coating powder is prepared by: (A) mixing (I) a diglycidyl ether of bisphenol A (DGEBA) having an epoxide equivalent (EEW) of 400- 900 and m.p. 70-110‹ C.; (II) a different DGEBA having EEW 750-1400 and m.p. 100-130‹ C, the wt. ratio of I : II being from 1 : 1 to 12 : 1; (III) 10-60% by wt. of the total of an epoxy resin ester prepared by reacting DGEBA (EEW 400-900) with HOOC.(CH2)n. COOH (n = 18-54) and (IV) 2-8 p.h.r. of a curing agent for I and II; (B) extruding the composition; (C) coating the composition to form a solid and (D) grinding to a powder, e.g. 15- 74 Á. IV may be dicyandiamide. The composition may also contain a curing accelerator, e.g. a mixture of 2-methylimidazole and dicyandiamide. Extrusion may take place in a kneader at a temperature near but above the melting point of the composition. A flow control agent may also be present. Uses:-Wire coating.</p> |
