| 摘要 |
1,261,404. Electro-depositing resins. CHEMISCHE WERKE ALBERT. April 25, 1969 [April 25, 1968], No.21276/69. Heading C7B. A synthetic condensation resin is electrodeposited from an aqueous suspension of the powdered resin on to an electrically conductive surface e.g. of steel of Al. A phenolic resin e.g. a resol or novolak having a melting point of at least 60‹ C., a polyester resin based on an aliphatic or aromatic carboxylic acid having up to 18 C atoms e.g. tere- or iso-phthalic, adipic, sebacic, maleic or fumaric acid, a polyether resin, and/or a polyamide resin e.g. polycaprolactam, polyhexamethylene adipamide, a poly-#-lactam or polyundercanoamide may be used. The alcohol component of the polyester resin is preferably polyhydric e.g. (di) ethylene glycol, glycerol, trimethylolpropane or -ethane, dimethylolpropanediol or a butanediol or hexanediol. The suspension may also contain 0À01-5% (by weight of resin) of cationic, anionic or nonionic wetting agent, e.g. sodium lauryl sulphate, and a powdered pigment e.g. TiO 2 . Preferred operating conditions are: temperature between ambient and 50‹ C., current density of 0À1-30 mA/cm<SP>2</SP> and potential difference of 5-200 volts D.C. The pigment may be stirred into a melt of the resin and the melt cooled and milled prior to forming the suspension. The coating is preferably stored at a temperature above the softening temperature of the resin. For example, polyundecanoamide powder, or a polyester powder prepared by polycondensation of butane-1, 4-diol, ethylene glycol monobutyl ether, adipic acid and styrene-maleic anhydride copolymer and milling, is suspended and stirred in a solution of an alkylphenol polyglycol ether and sodium lauryl sulphate with n-octyl alcohol. |
