| 摘要 |
A flame-retarding composition consisting of a dispersion in water of polyvinyl chloride, polyvinylidene chloride, a vinyl chloride-vinylidene chloride copolymer or a mixture of these polymers, antimony trioxide and a plasticizer, is prepared by dispersing the antimony trioxide in the plasticizer, emulsifying the resultant dispersion in water with the aid of an emulsifying agent and mixing the resultant emulsion with a latex of the polymer. The plasticizer may be a mixture of a conventional plasticizer and a chlorine-containing plasticizer as described in Specification 791,802. The emulsifying agent may be dioctyl sodium sulphosuccinate, part of which may be dissolved in the plasticizer prior to dispersion therein of the antimony trioxide. In a preferred process, the pH of the water employed for producing the emulsion may be decreased by adding acid, e.g. acetic acid, and raised after admixture of the emulsion with the latex by addition of alkali, e.g. ammonia. |
