Patent GB-692414-A (GB)
Title: Improvements in or relating to products for use as inhibitors, wetting agents, detergents and the like
Filed: 1948-07-01
Abstract: Polyethylene glycol thioethers of 2-mercapto-benzothiazole having the general formula <FORM:0692414/IV (a)/1> where n is an integer having any value between 3 and 29, are prepared by passing ethylene oxide into 2-mercapto benzothiazole in the molten state until between 5 and 31 mols. of ethylene oxide have reacted per mol. of said benzothiazole.  The ethylene oxide may be used in gaseous or liquid form.  The reaction is preferably carried out in the presence of a small amount of alkali such as sodium or potassium hydroxide. Examples describe the production of ethers having the above formula wherein n has the values 7, 8 and 13; reaction temperatures of 190-200 DEG  C. are used.  The products are liquids which may be used as wetting agents and detergents (see Groups III and IV (c)), wherein they may be used in conjunction with starch, tetrasodium pyrophosphate, trisodium phosphate, sodium metaphosphate, sodium tri-and tetraphosphate, sodium sulphate, sodium carbonate or other builders.  Their use as inhibitors in iron and steel pickling is claimed in Specification 692,413, [Group II].ALSO:Polyoxyethylene thioethers of 2-mercapto benzothiazole having the general formula <FORM:0692414/IV (b)/1> where n is an integer having any value between 3 and 29, are prepared by passing ethylene oxide into 2-mercapto benzothiazole in the molten state until between 5 and 31 mols. of ethylene oxide have combined per mol. of said mercapto benzothiazole.  The ethylene oxide may be used in gaseous or liquid form.  The reaction is preferably carried out in the presence of a small amount of alkali such as sodium or potassium hydroxide.  The products are liquids which may be used as wetting agents and detergents (see Groups III and IV (c)).  Their use as inhibitors in the pickling of iron and steel is claimed in Specification 692,413, [Group II].  Examples describe the production of ethers of the above general formula in which n has the values 7, 8 and 13, the reaction being carried out at 190 DEG  to 200 DEG  C. either by passing gaseous ethylene oxide through the molten mercapto-benzothiazole or by treating the molten mercapto-benzothiazole in an autoclave with liquid ethylene oxide; caustic soda or potash is used as catalyst in each case. The products are stated to be soluble in dilute sulphuric or hydrochloric acid.ALSO:Polyethylene glycol thioethers of 2-mercapto-benzothiazole having the general formula <FORM:0692414/IV (c)/1> wherein n is an integer having any value between 3 and 29, may be used as wetting-agents.  Ethers of the above formula wherein n is 7, 8 and 13, respectively, are described; they are soluble in dilute aqueous sulphuric and hydrochloric acids.  Their preparation is given (see Group IV (b)).  The use of the ethers in detergents with various builders is mentioned (see Group III). Their use as inhibitors in iron and steel pickling is claimed in Specification 692,413, [Group II].ALSO:Polyethylene glycol thioethers of 2-mercapto benzothiazole having the general formula <FORM:0692414/III/1> where n is an integer having any value between 3 and 29, may be used as detergents.  An example describes a composition comprising 20 per cent of an ether of the above formula wherein n is 13 and, as builders, 40 per cent each of starch and tetrasodium pyrophosphate.  Ethers of the above formula wherein n is 7 or 8 are also mentioned.  Other builders mentioned are sodium carbonate, trisodium phosphate, sodium tripolyphosphate, sodium tetraphosphate, sodium metaphosphate and sodium sulphate.  The preparation of the thioethers is described (see Group IV(b)). Specification 692,413, [Group II], is referred to.