| 摘要 |
The emulsions (I) comprise, on wt. (I) A) up to 6 wt.% amorphous highly dispersed SiO2 powder B) up to 1 wt.% anionic heteropolysaccharide (obtd. by fermentation of carbohydrates with Xanthomonas spp.) C) up to 10 wt.% vegetable oils and/or phthalate resins modified by such oils, the oils and resins being air-drying, and solns., dispersions, and/or emulsions of film-forming plastic resins or binders, chelating agents, and acid activators. In the prodn. of (I) an oily-organic and an aq. phase are formed separately and SiO2 gel is added during emulsification of both phases. Pref. (I) contain as binders highly alkali-resistant styrene-butadiene copolymer latex and soln. of a vinyltoluene-acrylate ester in white spirit, and as C), wood oil, Total water content of (I) is below 50%, partic. below 45%. (I) contain up to 10 wt.% pigment and/or filler, partic. ground natural quartz rock. (I) also contain small amts. of emulsifiers, penetrating agents, nonionic surface-active agents, and water-miscible organic solvents. (I) contain 10-30 wt.% resin or binder, 0.5-6 wt.% chelating agent, and amt. of acid activator such that pH of (I) is 1-6. Resin or binder is a copolymer, e.g., styrene-butadiene or vinyltoluene-acrylate ester, or is PVAc or PVA; chelating agent is a tannin and/or gallic acid whose effect is potentiated by salicylic, benzoic, or resorcylic acid, resorcinol, hydroquinone, and/or pyrogallol; acid activator is volatile organic acid. |
