| 摘要 |
<p>An acid-hardenable varnish, which can be diluted with water, contains two components as binding agents which are combined by mixt. or partial co-condens. at temps. between 30 degrees C and reflux, under normal press. The components are- (a) 45-90 wt.% of a water-soluble urea-formaldehyde condensate, of low molecular wt., partially etherified with 50% 1-3C monoalcohols and 0-50% 4C monoalchols and/or diols and/or diolomonoalkylethers and (b) 10-55 wt.% of an oil-free satd. polyester wit hydroxyl index 250-400 and contg. 10-25 wt.% of a polyethyleneglycol with mean mol. wt. 300-1000, pref. 300-750. Up to 10 wt.% of the urea-formaldehyde condensate can be replaced by a water-soluble aminotriazine-formaldehyde condensate, partially or totally etherified, if necessary with auxiliary organic solvents. The partial co-condensation is pref. conducted until the intrinsic viscosity is 5-10 ml/g (measured in dimethylformamide at 20 degrees C). Varnishes made from these materials can be used, and applied, in all kinds of ways on wood, for which hitherto products dissolved in solvents have been used, e.g. for parquet floors, and furniture. The materials require relatively low quantities of catalysts, e.g. 1% p-toluenessulphonic acid, compared with 7% for previous art materials. The coatings produced have a remarkable resistance to scratching abrasion and solvents, a high polish, good covering power and resistance to yellowing. Drying is rapid.</p> |
