Patent GB-394077-A (GB)
Title: Improvements in or relating to the production of aqueous dispersions of rubber or the like materials
IPC: C08J3/20
Filed: 1932-03-03
Abstract: Compositions containing rubber and a water-soluble soap, such as ammonium soaps, soft soap or potash soap, as the continuous phase are obtained by heating the rubber, preferably pre-masticated and compounded, to a relatively high temperature such as 140 DEG  C. upwards to reduce it to a viscous and preferably adhesive condition and then mixing it, preferably while warm, with a water-soluble soap, preferably in a pasty condition.  The composition may be admixed with an aqueous medium which may contain additional colloidal dispersing agents, or the softened rubber may be admixed with an aqueous medium under such conditions that a water-soluble soap is produced in situ. The rubber may be heated alone or in the presence of a high boiling organic liquid, such as a suitable petroleum fraction, oleic acid or a mixture p  thereof, and the heating may be carried out at ordinary or increased pressure and in the presence of air or steam.  The rubber may be pre-masticated and the addition of a small quantity of an oxide substance such as benzoic acid towards the end of the mastication assists the softening of the rubber on heating.  The compositions may be prepared with coagulated unvulcanized or vulcanized rubber, guttapercha, synthetic rubber, rubber waste, rubber reclaim, mixtures of two or more of the above substances, or mixtures of one or more of the same with rubber substitutes such as factice.  The compositions or their aqueous dilutions may be admixed with natural emulsions containing rubber, balata, guttapercha or similar vegetable resins, or with bitumen dispersions.  According to examples: (1) smoked sheet rubber is mixed with an equal quantity of mineral oil and heated at about 140 DEG  C. with stirring for about six hours.  The mass is then kneaded and mixed with pasty ammonium oleate, prepared by adding concentrated ammonia to oleic acid.  The product is diluted with water and mixed with concentrated latex (containing 60 per cent of rubber) giving a final product containing about 30 per cent of rubber hydrocarbons and giving adhesive films on evaporation.  (2) Pale crape rubber is first masticated on a cold mill and is then mixed with an equal quantity of mineral oil and heated to about 160 DEG  C.  The viscous mass is dispersed with pasty ammonium oleate, diluted and mixed with concentrated latex as in the previous example.  (3) Smoked sheet rubber is heated at 190 DEG  C. with stirring and the viscous mass mixed with mineral oil, oleic acid and petroleum spirit.  This mixture is then emulsified with an aqueous mixture of gum acacia, casein and concentrated ammonia. The emulsion may be mixed with concentrated latex.  The compositions may be used for the production of waterproofed or coated fabrics or as adhesives.ALSO:In a process for preparing compositions containing rubber and a water-soluble soap as the continuous phase, the rubber, preferably premasticated and compounded, is heated to a relatively high temperature such as 140 DEG  C. upwards, either alone or in the presence of a high boiling organic liquid, such as a suitable petroleum fraction, oleic acid or a mixture thereof.  The heating may be carried out at ordinary or increased pressure, and in the presence of air or steam.  When the rubber is pre-masticated, the addition of a small quantity of an acidic substance, such as benzoic acid, towards the end of the mastication assists the softening of the rubber.