Patent GB-613424-A (GB)
Title: Improvements in or relating to the production of mahogany acids and their soaps
IPC: C07C309/62
Filed: 1945-06-20
Abstract: Mineral oils are reacted with sulphuric acid, whereby a solution containing sulphonic acids is obtained, the bulk of the sludge formed is removed by mechanical means, the resulting sulphonated oil is then treated with a finely-divided absorbent of diatomaceous or siliceous origin or carbon, the so-formed pepper sludge-absorbent complex removed by mechanical means and the product subjected to air or inert gas blowing or vacuum stripping to remove dissolved sulphur dioxide. With complete sulphonation, a white oil may be obtained.  The resulting solution of mahogany acids may be neutralised with a base such as ammonia, alkali metal hydroxides or carbonates, alkanolamines or morpholine to produce soluble oils which may serve as cutting oils.  Emulsifying agents may be obtained either by solvent extracting the mahogany acids and neutralising with a base or solvent extracting the soaps from the soluble oils; alternatively, the soluble oils themselves may be used as emulsifiers.  The soluble oils may be fortified with further quantities of mahogany soaps or other emulsifiers, or coupling agents such as diethylene glycol may be added.  The soaps may be used in mineral oils.  The emulsifiers find application in the textile and leather industries and in emulsified liquid polishes and plant, animal and fruit sprays.  In examples, a mineral oil is treated with fuming sulphuric acid in three stages, with centrifuging between each stage to remove sludge, the oil is next treated with "Celite" (a Registered Trade Mark), filtered and either air blown or passed down a packed column under vacuum to remove sulphur dioxide and then neutralised with sodium hydroxide or carbonate and dried; the soluble oil obtained may be extracted with aqueous isopropanol to isolate the soaps.  The soluble oil and soaps form stable emulsions with water. Specification 587,624 is referred to.ALSO:Mahogany acids are prepared by reacting a mineral oil with sulphuric acid whereby sulphonic acids are formed, mechanically removing the bulk of the sludge formed, treating the sulphonated oil with a finely-divided absorbent of diatomaceous or siliceous origin or carbon, removing the pepper sludge-absorbent complex so formed by mechanical means and removing dissolved sulphur dioxide by air or inert gas blowing or vacuum stripping to yield a solution of mahogany acids.  The mahogany acids may be recovered p  from the solution by solvent extraction with, for example, water, dilute aqueous alcohol, acetone or other hydrocarbon immiscible solvent.  Alternatively, they may be neutralized with a base such as ammonia alkali metal hydroxides and carbonates or alkanolamines or morpholine to give mahogany soaps which may be left in solution or be solvent-extracted. Sulphonation is effected with strong or fuming sulphuric acid, generally in stages, the sludge being separated at each stage; sulphonation may be carried to such an extent as to leave no sulphonatable residue.  Suitable absorbents are diatomaceous filter aids, tripoli, silica, carborundum, attapulgus fines and activated carbons.  Mechanical means of separation are settling and filtration. The mahogany acid products have the usual applications in the textile, leather and agricultural industries as emulsifying agents, the soluble oils also being useful as cutting oils (see Group III). In examples: (1) a mineral oil is treated in three stages with fuming sulphuric acid, in each stage sludge being removed by centrifuging, and the sulphonated oil is then treated with "Celite" (Registered Trade Mark), filtered, air blown or passed down a packed column under vacuum to remove sulphur dioxide, neutralized with aqueous sodium hydroxide and dried by heating; (2) as in (1), the resultant solution of mahogany soaps being extracted with aqueous isopropanol and the soaps isolated by distillation of the solvent.  Specification 587,624, [Group III], is referred to.ALSO:Mahogany acids prepared by reacting a mineral oil with sulphuric acid, whereby sulphonic acids are formed, mechanically removing the bulk of the sludge formed, treating the sulphonated oil with a finely-divided absorbent of diatomaceous or siliceous origin or carbon, removing the pepper sludge-absorbent complex so formed by mechanical means and removing dissolved sulphur dioxide by air or inert gas blowing or vacuum stripping to yield a solution of mahogany acids, (see Group IV (b)) from which the mahogany acids may be recovered from the solution by solvent extraction or which may be neutralised with a base such as ammonia, alkali metal hydroxides and carbonates or alkanolamines or morpholine to give mahogany soaps which may be left in solution or be solvent-extracted, have the usual applications in the textile, leather and agricultural industries as emulsifying agents, the soluble oils also being useful as cutting oils (see Group III). Specification 587,624, [Group III], is referred to.