| 摘要 |
1,140,189. Hydrolysed starch. W. A. SCHOL-, TEN'S CHEMISCHE FABRIEKEN N.V. 30 Aug., 1967 [31 Aug., 1966], No. 39656/67. Heading C3U. Natural or granular modified starch, which has been impregnated with 0À5-20% of a non- volatile inorganic acid and 5-50% of a watersoluble amide (both based on the weight of the starch), the mixture containing no more than 12% water, is hydrolysed by heating at 80- 200‹ C., while being kept fluidized by passing a gas stream therethrough. Exemplified starches are potato, maize, tapioca, oxidized potato, hydroxyethylated wheat and acetylated tapioca starches; many others are listed including high amylose starch. Specified acids are phosphoric, polyphosphoric, pyrophosphoric, sulphamic and sulphuric acids; specified amides are urea (preferred), methylurea, allylurea, thiourea, acetyl urea, dicyanourea, formamide, butyramide, and acrylamide. Other acids, e.g. HCI, HNO 3 or citric acid may be used additionally. From 0À1-2% of tricalcium phosphate, magnesium oxide or colloidal silica may be added to improve fluidizability. The gas used may be one or more of air, nitrogen or carbon dioxide; heating may be effected by means of this gas, or by heat-exchangers. The products may be insolubilized by reaction with aldehydes, e.g. formaldehyde, glyoxal, polyacrolein or dialdehyde starch, or by the addition of polyvalent metal salts, e.g. aluminium sulphate, basic aluminium chloride, or zirconyl ammonium carbonate. Compositions comprise, in the examples, starch with: (1) phosphoric acid, urea and tricalcium phosphate, (2) sulphamic acid, urea and silica, (3) sulphuric acid, urea and tricalcium phosphate. |
