Patent GB-421820-A (GB)
Title: Improvements in or relating to methods for the treatment of rubber, gutta percha andbalata
IPC: C08C19/08
Filed: 1933-06-23
Abstract: Liquid products obtained by mechanically working raw rubber, guttapercha, or balata in a rubber-mixing mill or like device and subsequently in a colloid mill until the product does not return to its original state when the mechanical working is discontinued, find applications in the manufacture of paints, distempers &c. The first mixing operation may be effected in a Bridge-Banbury mixing mill run at about 200 revolutions per minute for an hour, and the product may then be treated in a high speed colloid mill running at a rate up to 3--5000 r.p.m., for example, in a mill of the kind described in Specification 214,308, [Class 59], until the desired low viscosity is attained.  A rubber solvent such as naphtha or petroleum hydrocarbons may be added to the product obtained by treatment in the Bridge-Banbury mixer.  A dispersion of the liquid rubber product increases the dielectric strength of materials such as vegetable drying oils used as varnishes for the insulation of metal conductor windings, and such dispersions may be used in the production of cable insulations by paper lapping. The products of lower viscosity may be used as rubber-like coatings on materials such as phenol-aldehyde resins.  Dissolved in petrol or other solvents they may be sprayed on metals, for example, to prevent corrosion, and a first coat before cellulose spray painting.  Incorporated with drying oils of the linseed and tung oil type, they may be employed for general paint work, and for lithographic varnishes in printing.  Incorporated with oils, or used alone with stabilizers such as soap, casein, glues &c. the products form the hydrophobic phase in emulsions of the distemper type, wherein pigments are dispersed.ALSO:Liquid products are obtained by mechanically working raw rubber, guttapercha, or balata in a rubber-mixing mill or like device and subsequently in a colloid mill until the product does not return to its original state when the mechanical working is discontinued.  The first mixing operation may be effected in a Bridge-Banbury mixing mill run at about 200 revolutions per minute for an hour, and the product may then be treated in a high speed colloid mill running at a rate up to 3-5,000 r.p.m., for example, in a mill of the kind described in Specification 214,308, [Class 59], until the desired low viscosity is attained.  A rubber solvent such as naphtha or petroleum hydrocarbons may be added to the product obtained by treatment in the Bridge-Banbury mixer. The more viscous products obtained may be used as insulating fillings for electrical junction boxes, cables, or the like.  A dispersion of this liquid rubber also increases the dielectric strength of materials such as vegetable drying oils used as varnishes for the insulation of metal conductor windings, and such dispersions may be used in the production of cable insulations by paper lapping.  The liquid products of lower viscosity may be used as rubber-like coatings on materials such as phenol-aldehyde resins.  Dissolved in petrol or other solvents they may be sprayed on metals, for example, to prevent corrosion, and as a first coat for cellulose spray painting. Incorporated with drying oils of the linseed and tung oil type, they may be employed for general paint work, and for lithographic varnishes in printing. Compositions formed by mixing bitumen with these liquid rubber products, for example, 95 per cent of bitumen with 5 per cent of the rubber product, have a low temperature susceptibility. Incorporated with oils, or used alone with stabilizers such as soap, casein, glues &c. the products form the hydrophobic phase in emulsions of the distemper type, wherein pigments are dispersed. The products may be vulcanized, causing the rubber to regain its original nervous and other mechanical properties.