| 摘要 |
<p>1,148,023. Starch phosphates. SCHOLTEN RESEARCH N.V. 14 Nov., 1967 [15 Nov., 1966], No. 51661/67. Heading C3U. [Also in Divisions B2 and C4] Depolymerized starch phosphate esters are prepared by heating starch, a phosphoruscontaining acid or a salt thereof and preferably also a water-soluble amine, amide, or ammonium salt, at 80-200‹ C. for 15 mins. to 24 hours. The phosphorus compound may be ortho- or a polyphosphoric acid or an acid or neutral alkali metal or ammonium salt thereof. The nitrogen compound, if used, is preferably urea; alternatively thiourea, methyl-, methylol- or acetyl urea, cyanamide, dicyandiamide, formamide, acrylamide, triethanolamine, ammonium carbonate or an ammonium salt of an organic acid may be used. The starch may be modified or unmodified, and may be a flour. Esterification and depolymerization take place conjointly, and may be effected under vacuum and/or absence of oxygen, optionally in the presence of HCl or H 2 SO 4 , to give predominantly the monoesters in a product with a viscosity in 15% aqueous solution at 25‹ C. of <800 centipoises, measured in a rotational viscosimeter at a shear rate of 480 sec<SP>-1</SP>. Example 1 employs tapioca starch heated with H 3 PO 4 and urea at 126‹ C. for 45 mins.; Example 2 potato starch, polyphosphoric acid and urea at 124‹ C. for 35 mins; Example 3 corn starch and H 3 PO 4 partially neutralized with NaOH at 150‹ C. for 40 mins.</p> |
