PROCEDIMIENTO PARA LA PREPARACION DE RESINAS ARTIFICIALES SOLUBLES EN AGUA.

摘要

1,182,521. Water soluble resins. VIANOVA KUNSTHARZ A.G. L9 Jan., 1968 [19 Jan., 1967], No. 3101/68. Heading C3B. [Also in Division C7] Water soluble resins are prepared by reacting at elevated temperature, e.g. 60-200‹ C.: (I) a compound containing more than one but not more than two epoxy groups per molecule with (II) an etherified or non-etherified methylol compound capable of forming a macromolecule at 100-200‹ C., either alone or with another hydroxy compound by forming ether or methylene linkage. An epoxy-free reaction product is obtained which is further reacted with a polybasic carboxylic acid or anhydride (III) and the resultant product rendered water soluble by neutralization with an inorganic and/or organic nitrogen base. (I) is preferably a diglycidyl ether of bisphenol A (M.W. 400-3000) which contains hydroxyl groups as well as epoxy groups, it may also be an epoxidized novolac resin. (II) may be a phenolic resin or an aminoplast derived from urea, melamine or benzoguanamine. (II) may also be an optionallyetherified methylol compound of a copolymer of (meth)-acrylamide or of a hydroxy containing silicone resin. (III) may be an adduct of anα,#-ethylenically unsaturated dicarboxylic acid or anhydride, e.g. maleic anhydride, with a fatty acid. (III) may also be a styrene/maleic anhydride copolymer having 2-8 anhydride groups per molecule. The process may be carried out in the presence of an alkaline catalyst and/or an inert solvent, e.g. diethylene glycol diethyl ether. In an example (II) is prepared by etherifying with butanol, a condensate of formaldehyde with p-tert-butylphenol. It is reacted with a bisphenol A/epichlorohydrin epoxy resin (epoxy equivalent 450-525) at 100-110‹ C. until no free epoxy groups are present. The product is then reacted in a solvent with an adduct of maleic anhydride and linseed oil/dehydrated castor oil. A water soluble resin is obtained on neutralization with an aqueous soln. of diethylamine. Coating compositions may contain conventional pigments and are suitable for electrodeposition.