GB848463A - Improvements in the manufacture of surface-active acylated hydroxy sulphonates - Google Patents

Abstract

Surface-active acylated hydroxy sulphonates of the general formula R COO R1,SO3M wherein R is a monovalent hydrocarbon radical containing 7 to 19 carbon atoms, R1 is a divalent hydrocarbon or dialkylene ether radical having 2-8 carbon atoms and M is an alkali metal, are prepared by heating an acid R COOH with a hydroxy sulphonate HO-R1-SO3 M, under conditions such that water is removed, in the presence of a salt of a weak base and a strong inorganic or organic acid. The weak bases are those weaker than the alkaline earth bases and the strong acids are those having a dissociation constant greater than 1 x 10-6. Specified salts are aluminium chloride, aluminium sulphate, alum, aluminium isethionate, basic aluminium acetate, aluminium dodecyl benzone sulphonate, aluminium dodecane sulphonate, aluminium acetyl acetonate, stannous chloride, stannic chloride, zinc chloride, zinc sulphate, zinc isethionate, hydrazine chloride, and generally weak base salts of the above hydroxy sulphonic acids HO-R1-SO3H. They are generally used in amounts of 0,1 to 10% by weight of the reaction mixture. Those hydroxy sulphonates wherein R1 represents a hydrocarbon radical may be reacted with excess of fatty acid R COOH and the product wholly or partially neutralised. Acylation may be effected at 200 DEG -250 DEG C., suitably while passing an inert gas, e.g. de-oxygenated nitrogen through the reaction mixture. Preferably, all the reaction promotor salt is added to a proportion of the reagents, the remainder of the reagents being added in proportionate amounts after reaction has commenced. A small proportion of preformed reaction product may also be added initially. Examples describe the reaction of lauric acid, coconut fatty acids and hydrogenated coconut fatty acids with sodium isethionate, sodium 2-methyl isethionate and sodium 3-hydroxy propane sulphonate in the presence of various of the above mentioned weak base-strong acid salts and sometimes of water and a comparative experiment shows the lower yield obtained in absence of a promoter. Other specified reagents include sodium dimethyl isethionate and myristic, stearic and oleic acids. According to the Provisional Specification, R and R1 in the above formulae are defined as representing organic and small divalent organic radicals respectively which may contain ring systems and in place of the weak base-strong acid reaction promotors there may be used organic derivatives of strong inorganic acids such as dodecane sulphonic acid, p-toluene sulphonic acid, b -naphthalene sulphonic acid, dodecyl benzene sulphonic acid, isethionic acid and mono-dodecyl phosphoric acid.ALSO:Surface-active compositions comprise compounds of the general formula RCOO.R1.SO3M wherein R is a monovalent hydrocarbon radical having 7 to 19 carbon atoms, R1 is a hydrocarbon or dialkylene ether radical having 2 to 8 carbon atoms and M is an alkali metal, obtained by heating an acid RCOOH with a hydroxy sulphonate HO.R1SO3M under conditions such that water is removed, in the presence of a salt of a weak base and a strong acid. The weak base is one weaker than the alkaline earth bases and the strong acid is an inorganic or organic acid having a dissociation constant greater than 1 X 10-6. These weak base-strong acid salts are not removed from the product. Specified salts are aluminium chloride, aluminium sulphate, alum, aluminium isethionate, basic aluminium acetate, aluminium dodecane sulphonate, aluminium dodecyl benzene sulphonate, aluminium acetyl acetonate, stannous and stannis chlorides, zinc chloride, zinc sulphate, hydrazine chloride and salts of weak bases with hydroxy sulphonic acids generally of the type HOR1SO3H where R1 is as above defined. These salts are generally used in amounts of 0.1 to 10% by weight of the reaction mixture. Those hydroxy-sulphonates wherein R1 represents a hydrocarbon radical are generally reacted with an excess of fatty acid and the product may then be wholly or partially neutralised and shaped into detergent tablets. Examples describe the reaction of excess of lauric acid, coconut fatty acids or hydrogenated coconut fatty acids with sodium isethionate, sodium 2-methyl isethionate and sodium 3-hydroxy propane sulphonate in the presence of various of the above named weak base salts. Other reagents mentioned include sodium dimethyl isethionate and myristic, stearic, oleic and tallow fatty acids. According to the Provisional Specification, R and R1 in the above formulae represent organic and small organic radicals respectively which may contain ring systems and in place of the specified weak base salts there may be used organic derivatives of strong inorganic acids such as dodecane sulphonic acid, p-toluene sulphonic acid, b -naphthalene sulphonic acid, dodecyl benzene sulphonic acid, isethionic acid and mono-dodecyl phosphoric acid.