Patent GB-475387-A (GB)
Title: Improvements in bituminous emulsions and method of preparing the same
IPC: C08L95/00
Filed: 1937-02-03
Abstract: Aqueous bituminous emulsions, stable against extremes of temperature are prepared by stabilizing a preformed quick-breaking emulsion with the aid of water-miscible blood, the pH value of the final emulsion being greater than 9.  The preformed emulsion is preferably made by the addition of the bituminous materials to alkaline solution, the asphaltogenic acids present acting as emulsifying agents, or by the addition of molten bitumen and alkali to a preformed emulsion, and if desired other emulsifying agents such as naphthenic acids, high molecular weight acids obtained by the partial oxidation of petroleum hydrocarbons or acids such as those contained in Montan wax may be added.  The blood is preferably first defibrinized or may be dried, provided that its solubility in water is not impaired, and may be added directly or in solution either to the hot emulsion, preferably at temperatures of 74--85 DEG  C. or to the cooled emulsion. Sufficient should be added to give at least 0,1 per cent, preferably 0,3--1,0 per cent, by weight of solids based on the weight of the final emulsion.  The final emulsion has a pH value of 11,5 approximately, which falls to about 9,0 on storage.  The emulsions may be neutralized. e.g. to a pH value between 10 and 11, e.g. by means of phosphoric acid.  Such neutralized emulsions dry more rapidly, and possesses greater resistance to heat than the unneutralized emulsion.  It is desirable to add a preservative such as formaldehyde or sodium arsenite to prevent mould or bacterial action.  According to examples, emulsions are prepared containing 58 per cent by weight of bitumen and stabilized with 1 per cent by weight of blood solids.  They may be preserved by the addition of 0,2 per cent by weight of sodium arsenite or 0,1, 0,3 or 0,5 per cent by weight of formaldehyde.  An emulsion containing the same weight of bitumen was stabilized by the addition of 0,67 per cent by weight of dried blood, and then neutralized to a pH value of 9,7 by the addition of dilute phosphoric acid.  The emulsion was preserved by the addition of 0,2 per cent of formalin, or 0,1 and 0,3 per cent of sodium arsenite.  Fibrous fillers, e.g. asbestos or cotton, and pigment fillers, e.g. ground petroleum coke, iron oxide, chromium oxide or limestone dust may be mixed with the final emulsion, or with the blood stabilizer prior to addition to the emulsion.  Cementitious materials, e.g.  Portland cement, hydrated lime or gypsum, may also be mixed with the emulsion.  A typical composition comprises 46 per cent emulsion containing 55--60 per cent of asphalt; 10 per cent pigment filler; 12 per cent fibrous filler and an additional 24 per cent of water. The emulsions may be used as coating or waterproofing compositions for metal, wood or concrete; for the impregnation of woven fabrics, felted fabrics and paper; for pipe sealing compounds; for electrical insulation compounds; for mixing with mineral aggregates in paving &c., and for soil stabilization processes. Specifications 226,032 and 254,012, [both in Class 81 (i)], are referred to.ALSO:Bituminous compositions are prepared with aqueous bituminous emulsions, stable against extremes of temperature, which comprise a preformed quick-breaking emulsion stabilized by the addition of water-miscible blood, the pH value of the emulsion being greater than 9.  The preformed emulsion is preferably made by the addition of the bituminous emulsions to alkaline solutions, the asphaltogenic acids present acting as emulsifying agents, and if desired other emulsifying agents such as naphthenic acids, high molecular weight acids obtained by the partial oxidation of petroleum hydrocarbons or acids such as those contained in Montan wax may be added.  Fibrous fillers, e.g. asbestos or cotton, and pigment fillers, e.g. ground petroleum coke, iron oxide, chromium oxide or limestone dust may be mixed with the final emulsion, or with the blood stabilizer prior to addition to the emulsion. Cementitious materials, e.g. Portland cement, hydrated lime or gypsum, may also be mixed with the emulsion.  A typical composition comprises 46 per cent emulsion containing 55-60 per cent of asphalt; 10 per cent pigment filler; 12 per cent fibrous filler and an additional 24 per cent of water.  The emulsions may be used as coating or waterproofing compositions for metal, wood or concrete; for the impregnation of woven fabrics, felted fabrics and paper; for pipe sealing compounds; for electrical insulation compounds; for mixing with mineral aggregates in paving &c., and for soil stabilization processes. Specifications 226,032 and 254,012, [both in Class 81 (i)], are referred to.