GB765880A - Improvements in or relating to ungelatinized tertiary amino alkyl ethers of amylaceous materials - Google Patents

Abstract

The invention comprises ungelatinized basic starch ethers of the formula X-O-R-NR1R2 where X is the starch residue, R is alkylene or hydroxyalkylene and R1 and R2 are alkyl or aryl (not both aryl) or together form a saturated ring with the nitrogen atom. These are made by reacting starch with an etherifying agent containing the basic residue under conditions such that gelatinization is avoided, e.g. when the amount of aqueous alkali would normally cause gelatinization a retardant such as sodium sulphate is added. Examples show the etherification of starch with b -diethylaminoethyl chloride, b -dimethylamino-isopropyl chloride, 3 - dibutylamino - 1 : 2 - epoxypropane, 2 - bromo - 5 - diethylamino - pentane, b - dioctylamino - ethyl chloride, N - (2 : 3 - epoxypropyl) - piperidine and N - (2 : 3 - epoxypropyl) - N - methylaniline. The product may be obtained as salt or free base. In a further example the b -diethylamino-ethyl ether is quaternated with methyl iodide. The starting material may be corn, wheat, potato, tapioca, waxy maize, sago or rice starch or dextrinized, hydrolysed, oxidized, esterified or etherified derivatives thereof; in particular there may be used corn starch which has been acid-converted or oxidized with hypochlorite. The basic ethers have improved stability on storage, particularly at low pH values. The etherification is preferably effected by adding the aminoalkyl halide (or other reagent) to a suspension of starch in water containing an alkali hydroxide or quaternary base. Alternatively the starch may be suspended in an inert medium such as isopropanol containing a quaternary base. The amount of etherifying agent may be 0.5-30 per cent by weight of the starch.ALSO:Basic starch ethers of the formula X-O-R-NR1R2, where X is the starch residue, R is alkylene or hydroxyalkylene and R1 and R2 are alkyl or aryl (not both aryl) or together form a saturated ring with the nitrogen atom, are used as thickeners for phenol solutions in the plisse printing of nylon fabrics to produce a puckered effect. An example shows the use of the b -diethylamino-ethyl ether, and other suitable compounds are mentioned.