Patent GB-685959-A (GB)
Title: Manufacture of ethers, esters or mixed ethers-esters of polysaccharides
Inventor: LOLKEMA JAN
IPC: C08B31/00
Filed: 1950-10-06
Abstract: Ethers, esters or mixed ether-esters soluble in cold and/or hot water are manufactured from polysaccharides, which swell or dissolve in hot water and are adapted to be made into a solution or paste with a small proportion of water, by heating a mixture of the polysaccharide, an etherifying agent and/or an esterifying agent and an alkaline substance, either after the etherification or esterification process, or in any desired stage of the process, in the presence of water substantially exceeding twice the weight of the polysaccharide, to a temperature adapted to remove the water and to gelatinize gelatinizable polysaccharides while the mixture is pressed or spread out under mechanical pressure into a thin layer on a rotary drum and the layer is simultaneously or immediately after dried and, if desired, subsequently comminuted. A mixture of the polysaccharide with more than twice its weight of water may be heated with an alkaline substance, the mixture pressed in a thin layer on a rotary drum and dried, and then treated with an etherifying and/or an esterifying agent. Suitable esterifying agents, etherifying agents, alkaline substances and polysaccharides are those described in the parent Specification.  In the examples: (a) ethylene oxide is added to a starch paste obtained by mixing potato starch, water and caustic soda; the mixture is neutralized with hydrochloric acid and then dried on a rotating cylinder; the hydroxyethyl ether thus formed dissolves in water to form a gum-like paste; (b) a mixture of sodium chloracetate and trichloracetic acid are added to a starch paste obtained by mixing cassava starch, water and caustic soda; the mixture is heated and dried; the product dissolves in water to give a gum-like solution; (c) the sodium salt of bromethane sulphonic acid is added to a starch paste obtained by mixing maize starch, water and caustic soda; the mixture is heated and dried to give a product which dissolves readily in hot or cold water; (d) propylene oxide is added to a starch paste obtained by mixing potato starch, water and caustic soda; the mixture is neutralized and dried to give a product which dissolves in water and other liquids, e.g. milk; (e) the sodium salt of chloracetic acid is added to a starch paste obtained by mixing potato starch with water and caustic soda solution; the mixture is heated, diluted and then dried to give a soluble product.ALSO:Materials which are valuable finishing and sizing agents and adhesives are obtained by heating a mixture of a polysaccharide, which swells or dissolves in hot water, an etherifying and/or esterifying agent and an alkaline substance, either after the etherification or esterification process, in the presence of water substantially exceeding twice the weight of polysaccharide, while the mixture is pressed into a thin layer on a rotary drum and the layer is simultaneously, or immediately after, dried and, if desired, subsequently comminuted.  Suitable esterifying agents, etherifying agents, alkaline substances and polysaccharides are those described in the parent Specification which is referred to.