POLYVINYL ESTER ADHESIVE

摘要

1440337 Adhesives comprising vinyl ester polymer dispersions HOECHST AG 12 Dee 1973 [15 Dec 1972] 57592/73 Heading C3P An aqueous adhesive comprises an aqueous vinyl ester polymer dispersion having a solids content of 40-60 wt. per cent, which contains 1-15 wt. per cent (based on the vinyl ester polymer) of polyvinyl alcohol as a protective colloid, from 1À5 to 3 wt. per cent (based on the total mixture) of a 40-70% solution of a water-soluble urea-formaldehyde resin and from 0À05 to 0À3 wt. per cent (based on the total mixture) of a water-soluble acid metal salt. The dispersion is preferably of polyvinylacetate. The metal salt may be a salt of Al, Fe, Cr, Ti, Zr, or V, specific examples being AlCl 3 , Al(NO 3 ) 3 , chromic nitrate, FeCl 3 , titanyl sulphate, zirconium oxychloride, and vanadyl sulphate. The compositions in the examples also contain butyl glycolate. The metal salt renders the adhesive more water resistant then prior adhesives based on vinyl ester polymers.