Patent GB-884034-A (GB)
Title: Detergent compositions
IPC: C11D1/37
Filed: 1960-03-21
Abstract: A detergent composition, preferably in liquid form, comprises (a) sec. alkyl sulphates of which at least 90% by weight consists of molecules containing at least 14 and not more than 18 carbon atoms, and (b) alkylbenzene sulphonates of which at least 85% by weight consists of molecules containing at least 8 and not more than 10 carbon atoms in the alkyl group, the weight ratio of (a) to (b) being 2:1 to 1:3.  If required, the alkyl sulphates (a) may consist entirely of sulphates containing 14 and/or 15 carbon atoms, or, alternatively, such sulphates may be entirely absent; the alkyl groups in at least 70 moles per cent of the sulphonates (b) preferably contain 8 and/or 9 carbon atoms.  In general, 30-90 moles per cent of (a) and (b) are ammonium salts, the remainder being sodium and/or potassium salts.  The composition usually contains a condensate of at least 6 moles of ethylene oxide with 1 mole of an alkyl-phenol or -cresol having 8-10 carbon atoms in the alkyl group in an amount by weight up to 40% of the total of (a) and (b), and may also contain similar condensates with fatty alcohols; ethanol, butanol, pentanol, urea, ammonium and alkali metal sulphates, persulphates, perborates, percarbonates, further detergents, optical bleach, and foam promoters and stabilizers may also be present.  The composition is usually produced in concentrated liquid form and diluted before use.ALSO:Sec. alkyl sulphates of which at least 90% by weight consists of molecules containing at least 14 and not more than 18 carbon atoms, and alkylbenzene sulphonates of which at least 85% by weight consists of molecules containing at least 8 and not more than 10 carbon atoms in the alkyl group are produced from olefins obtained by cracking such aromatic-free hydrocarbons as paraffin distillates, mineral oil residues, heavy fractions of cracked mineral oils, hydrogenated mineral oils, coal or tar, reaction products of carbon monoxide and hydrogen, petrolatum, ceresine, ozokerite, montan wax, paraffin wax, sweat oil, and lignite oils.  The sec. alkyl sulphates are obtained by sulphating the olefins with 90%-100% sulphuric acid at 0 DEG C.-25 DEG C., at a molar ratio of acid to olefins of 0.5-2 in the presence if desired of a diluent such as a saturated light oil; under these conditions only the unbranched olefins react.  The branched olefins are then sulphated by increasing the molar ratio of acid to olefins to 2-5 at -30 DEG C. to 0 DEG C. in the presence of a diluent.  The esters so formed are then neutralized by boiling with an inorganic base to convert any diesters to salts.  Unsulphated material may then be removed by extraction with 60 DEG C.-80 DEG C. gasoline, ethanol or propanol being preferably added first.  The alkylbenzene sulphonates are obtained by alkylating excess benzene with the olefin fraction in the presence of such catalysts as oleum, sulphuric acid, hydrofluoric acid, aluminium chloride or activated clay.  Sulphuric acid used as a catalyst should have a concentration of at least 80% by weight and be present in a ratio by volume of 2:1 to 1:2, the reaction being performed at 0 DEG C.-20 DEG C.  Hydrofluoric acid may be used either anhydrous, or, e.g., as a 46% solution, in a preferred ratio of 2:1 to 1:2, the reaction temperature then being 0 DEG C.-50 DEG C.  The subsequent sulphonation is generally carried out by means of oleum having a free SO3 concentration of 25%, at a molar ratio of total SO3 to hydrocarbon of e.g. 1:1 to 2:1, gaseous sulphur trioxide being introduced during the reaction together with fresh oleum.  Instead of oleum, chlorsulphonic acid, 98% sulphuric acid, or a solution of sulphur-trioxide in sulphur dioxide may be used. In any case, the final products are subsequently neutralized.  In preparing detergent mixtures of the sulphates and sulphonates (see Group III) the final neutral products may be mixed, the acid products mixed before neutralization, or the acid mixture from the sulphonation of the alkylbenzenes used directly to sulphate the olefins.  In an example, furfural-extracted petroleum cycle oil boiling above 300 DEG C. is cracked in the vapour phase in the presence of steam and the product fractionated to yield separate olefin mixtures containing olefins of 8-10 and 14-18 carbon atoms respectively.  The C8-10 fraction is mixed at 3 DEG C. with 10 times the molar quantity of benzene over a period of 1/2 hour with simultaneous addition of 98% sulphuric acid in an equimolar ratio to the hydrocarbon mixture.  After further agitation for 1 hour the phases are separated and the hydrocarbon layer mixed with an equal volume of 5% sodium hydroxide and 1/10 th this volume of isopropanol and boiled under reflux for 2 hours.  The hydrocarbon layer is again separated and twice washed with sodium chloride, after which benzene is distilled off and the alkyl-benzenes rectified in vacuo.  22% oleum is gradually added at 25 DEG C. in a molar ratio of SO3 (free and bound) to alkylbenzenes of 4:1, and the mixture stirred 1 hr.  Water is then added and the mixture kept 2 hrs. at 70 DEG C. at a sulphuric acid concentration of 70% by weight, after which the phases are separated and the hydrocarbon solution of sulphonic acids neutralized with sodium hydroxide.  The C14-18 olefin fraction is sulphated with an equimolar amount of 98% sulphuric acid at 18 DEG C. with a phase contact time of 3 minutes.  The mixture then flows into 2N sodium hydroxide so that 1.8 equivalents of hydroxide are present for each equivalent of olefin reacted with sulphuric acid.  The resultant mixture is kept at 90 DEG C. for 2 hours to convert dialkyl sulphates to monoalkyl sulphates.  Excess NaOH is then neutralized, the mixture cooled, ethanol added to a 25% by weight concentration and unsulphated material extracted with pentane.  Finally organic solvents are distilled off together with the amount of water necessary to leave a solution of the required concentration.