GB684038A - Improvements in or relating to a process of preparing carbohydrate adhesives and the like - Google Patents

Abstract

In making a carbohydrate, e.g. dextrin-like, adhesive a starch conversion syrup or liquor is dehydrated and then heated to polymerize the dry substance. A polymerization catalyst may be introduced before or after dehydration occurs. The liquor may be dried until the moisture content is under 10 per cent. Polymerization may be effected between 100 DEG and 200 DEG C. at a pH between 2 and 3 (as determined in an aqueous solution containing 10 per cent of the dry substance). Water vapour evolved during polymerization (chemical condensation) may be removed continuously. Suitable catalysts are boric acid, phosphoric acid, hydrochloric acid, aluminium chloride and nitrogen dioxide.ALSO:In making a carbohydrate, e.g. dextrin-like, adhesive a starch conversion syrup or liquor, e.g. having when dry a dextrose equivalent between 5 and 40 per cent by weight, is dehydrated and then heated to polymerize the dry substance. Syrup may be comminuted during drying and the resulting powder may be polymerized in the presence of a catalyst which may be added before dehydration occurs. Liquor may be spray-dried and the resulting powder may be polymerized between 100 and 200 DEG C. at a pH between 2 and 3 (as determined in an aqueous solution containing 10 per cent of the dry substance). The liquor may be dried until the moisture content is below 10 per cent, mixed with an acid catalyst and heated between the aforesaid temperatures and pH values to effect polymerization by chemical condensation. The water vapour evolved may be removed continuously. Suitable catalysts are boric acid, phosphoric acid, hydrochloric acid, aluminium chloride, and nitrogen dioxide.