Aqueous wood varnish for interior application and process for its preparation

摘要

An aqueous emulsion of alkali-modified wax, fatty acid and vegetable oil is used as the binder in a water-dilutable decorative wood varnish for interior use. A water-dilutable decorative wood varnish for interior use contains (a) 50-80 wt.% aqueous wax (alkali-modified)/fatty acid/vegetable oil emulsion (binder) with 20-35 wt.% solids and 80-65 wt% water, (b) 0-5 wt.% fillers, (c) 0.5-5 wt.% pigments, (d) water (to 100 wt.%) and optionally (e) a water-dilutable alkyd resin (cobinder) in a ratio of (a):(e) = 2:1. Independent claims are also included for (i) a process for the production of this varnish, comprising (a) placing about half of the binder emulsion in a stirred vessel, (b) adding fillers and mixing well, (c) adding pigments and dispersing for a few minutes with a stirrer speed of more than 500 r.p.m. to form a paste, (d) adding the rest of the binder, (e) optionally adding the alkyd resin and (f) adding the rest of the water with stirring; (ii) a process for production of the binder, starting from a hydrocarbon wax with oxygen-containing functional groups, by saponifying the acid groups in the wax with stoichiometric amounts of alkali in the melt, homogenizing with vegetable oil and fatty acid at 95-120 degrees C and then transferring to an in-line homogenizer in parallel with demineralised water at about the same temperature.