| 摘要 |
1,207,865. Plastic modelling composition. OIL CENTER RESEARCH Inc. 4 Jan., 1968 [4 Jan., 1967], No. 565/68. Heading C3U. A dry pulverulent composition adapted to be hydrated with from 1 to 200 times its weight of water to form a pliable, cohesive, mouldable, non-crumbly, non-toxic plastic composition comprises guar gum, preferably from 1 to 90% by weight, at least 0.1% by weight alkali metal borate preferably 0.1 to 20%, and sufficient boric acid to provide a sol. of pH less than 7 when added to water, preferably 5 to 98% by weight based on the total weight of the dry composition. The alkali metal borate may be borax, sodium perborate, potassium or sodium metaborate and potassium tetraborate. Part of the boric acid may be replaced by other acidic substances such as the water-soluble acid salts monosodium phosphate, aluminium sulphate and ammonium chloride and organic and inorganic acids such as acetic, nitric, citric, hydrochloric and sulphuric acids. The composition may also contain 0.5% by weight of a high molecular weight polysaccharide which is preferably the alkali deacetylated derivative of the acetyl ester form of a polymer of mannose, glucose and potassium glucuronate in the approximate ratio 2:1:1. A plurality of optional components such as fillers and extenders, e.g. TiO 2 , softeners, e.g. glycerine, colorants, perfumes, bacteriostats, fungistats may be included, as well as foaming agents or other additives or solids to effect a density change. |
