Patent GB-614049-A (GB)
Title: Improvements in detergent and process for producing the same
IPC: A61B6/02
Filed: 1946-07-03
Abstract: Detergents are produced by etherifying cellulose with an alkylene oxide in the presence of a strongly alkaline substance selected from the group consisting of the hydroxides of the alkali metals, aliphatic amines and the quarternary ammonium bases, continuing the reaction until a water-soluble cellulose ether is produced, and neutralizing the alkali in said reaction mixture with a higher fatty acid or mixture of such acids which reacts with the alkali to form a soap in situ.  The cellulosic starting material may be cellulose in any of the forms in which it occurs in nature, e.g. wood pulp or cotton linters, preferably bleached or scoured to remove non-cellulosic constituents, purified wood pulp being particularly suitable.  Alternatively there may be used cellulose conversion products such, for example, as p  oxy-cellulose, hydrocellulose and cellulose hydrates of all kinds including cellulose hydrate formed by the mechanical beating of cellulose in the presence of water, or by treating cellulose with mineral acids or alkalies, and cellulose hydrate formed by regeneration from viscose and cuprammonium solutions or by de-esterification of cellulose esters.  The fatty acid may be saturated or unsaturated and may have 8 or more carbon atoms in the chain.  The cellulosic material may be converted to alkali cellulose by steeping it in an aqueous solution of the strongly alkaline substance (e.g. 10 per cent to 25 per cent, preferably 18 per cent) at room temperature, the alkali cellulose pressed to remove excess alkali solution, and etherified with an alkylene oxide, e.g. ethylene or propylene oxide or a glycide, while wet with the alkali solution until a water-soluble cellulose ether is produced.  The alkali in the reaction mixture which is generally about 9 to 12 per cent by weight of the reaction mixture, is then neutralized with the higher fatty acid.  On a dry basis the finished material may contain 55 to 65 per cent by weight soap and 45 to 55 per cent cellulose ether.  In an example, 285 lbs. of wood pulp are steeped in an excess of 25 per cent aqueous sodium hydroxide solution for 45 minutes at 26 DEG -27 DEG  C. and the excess of caustic soda solution pressed out, leaving 704 lbs of alkali cellulose.  The mass is then shredded and aged for 63 hours.  This material is transferred to a "vacuum" shredder and 225 lbs. of ethylene oxide added over a period of 9 hours, the temperature being controlled between 16 DEG and 20 DEG  C. 933 lbs. of product containing about 12 per cent of sodium hydroxide are obtained. 87.5 lbs. of 96.8 per cent oleic acid are added to every 100 lbs. of the reaction product in a shredder during 3 1/2 hours at 24 DEG -30 DEG  C. and 182 lbs. of detergent obtained.ALSO:Cellulose ether preparations having detergent properties are produced by etherifying cellulose with an alkylene oxide in the presence of a strongly alkaline substance selected from the group consisting of the hydroxides of the alkali metals, aliphatic amines and the quaternary ammonium bases, continuing the reaction until a water-soluble cellulose ether is produced, and neutralizing the alkali in said reaction mixture with a higher fatty acid or mixture of such acids which reacts with the alkali to form a soap in situ.  The cellulose may be in any of the forms in which it occurs in nature, e.g. wood pulp or cotton linters, preferably bleached or scoured to remove non-cellulosic constituents, purified wood pulp being particularly suitable. Alternatively, there may be used cellulose conversion products such as, for example, oxycellulose, hydrocellulose and cellulose hydrates of all kinds including cellulose hydrate formed by the mechanical beating of cellulose in the presence of water, or by treating cellulose with mineral acids or alkalies, and cellulose hydrate formed by regeneration from viscose and cuprammonium solutions.  The fatty acid may be saturated or unsaturated and may have 8 or more carbon atoms in the chain.  Prior to etherification, the cellulosic material may be converted into alkali cellulose by steeping it in an aqueous solution of the alkaline substance at room temperatures, the proportion of alkali being, for example, 10 to 25 per cent, preferably 18 per cent of that of the cellulose.  The alkali cellulose is then pressed to remove excess alkali and then etherified, e.g. with ethylene or propylene oxide or a glycide, while wet with the remaining alkali solution.  The alkali in the reaction mixture (which generally contains about 9 to 12 per cent by weight of alkali) is then neutralized with the higher fatty acid.  On a dry basis the finished material may contain 55 to 65 per cent by weight of soap and 45 to 55 per cent by weight of cellulose ether.  In an example, 285 lbs. of wood pulp are steeped in an excess of 25 per cent aqueous sodium hydroxide solution for 45 minutes at 26-27 DEG C. and the excess caustic soda solution pressed out, leaving 704 lbs. of alkali-cellulose.  The mass is then shredded and aged for 63 hours, transferred to a "vacuum" shredder and 225 lbs. of ethylene oxide added over a period of 9 hours, the temperature being controlled between 16 DEG  and 20 DEG  C. 933 lbs. of product containing about 12 per cent of sodium hydroxide are obtained. 87.5 lbs. of 96.8 per cent oleic acid are added to 100 lbs. of the reaction product in a shredder during 3 1/2 hours at 24-30 DEG  C. 182 lbs. of a detergent preparation consisting of an intimate mixture of etherified cellulose and soap are obtained.