Patent GB-377257-A (GB)
Title: Improvements relating to electric accumulators
IPC: H01M50/491
Filed: 1931-04-15
Abstract: Separators and supports for electrodes, permeable to electrionic flow and substantially non-hydrolysable in the electrolyte of a storage battery comprise in major part by volume finely divided material inert to the electrolyte and in minor part scattered particles of binding agent which have been set out of an initially fluid or plastic agent which had been previously dispersed into the discontinuous phase of an emulsion in a liquid non-miscible therewith.  Two or more cementing materials may be mixed, or they may first be mixed with separate portions of comminuted material, and these portions mixed together.  The separators and supports may also contain fibrous material, such as cotton linters, asbestos fibre, spun glass, and "Vulcan's Hair," a form of mineral wool.  The examples of suitable compositions include (1) rubber latex, with sufficient sulphur for vulcanization, and diatomaceous earth, preferably the calcined earth to avoid premature coagulation of the latex.  (2) A phenol condensation product is substituted for the latex.  (3) The mixture comprises equal proportions of (1) and (2). (4) An emulsion of any pitch, asphalt, resinous, waxy, or bituminous substance with water is made in a mixing machine or autoclave by using a small quantity of a porous hydrous material such as diatomaceous earth.  For example a mixture of two parts of coumarone varnish and one part of an asphaltic oil residue may be emulsified. If necessary, the emulsion is reversed by means of a suitable colloid, such as the clay "Bentonite," the inert powder is then added, and the whole moulded and set by heat.  (5) Sodium silicate solution containing a high proportion of silica is emulsified with a volatile oil such as toluene, using as emulsifying agent a soap such as ammonium linoleate, and applied as before.  Or a non-volatile oil such as castor oil may be used, being afterwards removed by washing with a volatile miscible oil. (6) An emulsion of pyroxylin is utilized.  Instead of diatomaceous earth, mica, kaolin, or asbestos having very short fibres may be used.  Any of these mixtures before setting may contain enough liquid to make it fluid, so that it may be applied directly to the electrodes or to the fibrous support as a paint.  With less liquid it may be pasted on to cloths or wire netting.ALSO:Separators and supports for electrodes, permeable to electrionic flow and substantially non-hydrolysable in the electrolyte of a storage battery comprise in major part by volume finely divided material inert to the electrolyte and in minor part scattered particles of binding agent which have been set out of an initially fluid or plastic agent which had been previously dispersed into the discontinuous phase of an emulsion in a liquid non-miscible therewith.  Two or more cementing materials may be mixed, or they may first be mixed with separate portions of comminuted material, and these portions mixed together.  The separators and supports may also contain fibrous material, such as cotton linters, asbestos fibre, spun glass, and "Vulcan's Hair," a form of mineral wool.  The examples of suitable compositions include (1) rubber latex, with sufficient sulphur for vulcanization, and diatomaceous earth, preferably the calcined earth to avoid premature coagulation of the latex.  (2) A phenol condensation product is substituted for the latex.  (3) The mixture comprises equal proportions of (1) and (2). (4) An emulsion of any pitch, asphalt, resinous, waxy, or bituminous substance with water is made in mixing machine or autoclave by using a small quantity of a porous hydrous material such as diatomaceous earth.  If necessary, the emulsion is reversed by means of a suitable colloid, such as the clay "Bentonite," the inert powder is then added, and the whole moulded and set by heat. (5) Sodium silicate solution containing a high proportion of silica is emulsified with a volatile oil such as toluene, using as emulsifying agent a soap such as ammonium linoleate, and applied as before.  Or a non-volatile oil such as castor oil may be used, being afterwards removed by washing with a volatile miscible oil. (6) An emulsion of pyroxylin is utilized.  Instead of diatomaceous earth, mica, kaolin, or asbestos having very short fibres may be used.  Any of these mixtures before setting may contain enough liquid to make it fluid, so that it may be applied directly to the electrodes or to the fibrous support as a paint.  With less liquid it may be pasted on to cloths or wire netting.