Patent GB-580189-A (GB)
Title: Improvements relating to sulphur-containing compounds or compositions and methods of making the same
IPC: C08L21/00
Filed: 1944-06-15
Abstract: A vulcanizing agent for synthetic rubbers is made by reacting sulphur with a partly unsaturated hydrocarbon oil, tar, asphalt, neutralized petroleum acid sludge extract or the like having a boiling point above 160 DEG  C. at 12 mm. mercury, at a temperature above the melting point of sulphur, at which hydrogen sulphide is evolved, e.g., 190 DEG -215 DEG  C., until the sulphur loss is at least three per cent. of the final product.  The hydrocarbon should contain about 90 per cent. carbon, and ten per cent. hydrogen, and be at least 40 per cent. soluble in concentrated or fuming sulphuric acid.  The progress of the reaction is indicated by the sulphur loss, irrespective of the amount of sulphur originally present; five per cent. loss normally shows the reaction to be complete, although useful products are obtained with a loss of three to seven per cent. Stable, homogeneous products containing up to 35 per cent. of sulphur may be so obtained.  Completion of the reaction is also accompanied by an increase of viscosity to at least four times that of the starting material.  According to an example, 85 parts by weight of extract of acid sludge of lubricating oil having a boiling point of 250 DEG -360 DEG  C. at 12 mm. mercury is mixed with 15 parts of sulphur and heated at 190 DEG  C. for four hours, giving a product containing nine per cent. of sulphur available for vulcanization and having a viscosity of approximately 200 centipoises at 100 DEG  C. Heating to 215 DEG  C. for 30 mins. gives a product containing 8.6 per cent. sulphur and a viscosity of 110 centipoises.  The product co-vulcanizes with the rubber.ALSO:A vulcanizing agent for synthetic rubbers is made by reacting sulphur with a partly unsaturated hydrocarbon oil, tar, asphalt, neutralized petroleum acid sludge extract or the like having a boiling point above 160 DEG C. at 12mm. mercury, at a temperature above the melting point of sulphur, at which hydrogen sulphide is evolved, e.g., 190-215 DEG C. until the sulphur loss is at least 3 per cent. of the final product.  The hydrocarbon should contain about 90 per cent. carbon and 10 per cent. hydrogen, and be at least 40 per cent. soluble in concentrated or fuming sulphuric acid.  The progress of the reaction is indicated by the sulphur loss, irrespective of the amount of sulphur originally present; 5 per cent. loss normally shows the reaction to be complete, although useful products are obtained with a loss of 3-7 per cent. Stable homogenous compositions containing up to 35 per cent. of sulphur may be so obtained.  Completion of the reaction is also accompanied by an increase of viscosity to at least four times that of the starting material.  According to an example, 85 parts of weight of extract of acid sludge from lubricating oil having a boiling point of 250-360 DEG C. at 12 mm. mercury is mixed with 15 parts of sulphur and heated at 190 DEG  C. for four hours, giving a product containing 9 per cent. of sulphur available for vulcanization and having a viscosity of approximately 200 centipoises at 100 DEG C.  Heating to 215 DEG  C. for 30 min. gives a product containing 8.6 per cent. sulphur, and a viscosity of 110 centipoises.  The product co-vulcanizes with the rubber.