GB417845A - Improvements in the manufacture of hard or highly viscous materials - Google Patents

Abstract

A modification of the process described in the parent Specification for producing a solid electrically-insulating material by making a mixture which is liquid or semi-liquid at normal temperatures and sets at a definite slow rate after mixing and which comprises rosin, a liquid vehicle and a base in the form of an oxide or hydroxide of an alkaline earth or other metal comprises replacing the rosin wholly or in part by certain fatty acids and certain products of the destructive distillation of organic materials. The fatty acids are those which occur in or are derived from natural oils, fats and waxes and which are substantially insoluble in water and of an oily or wax-like nature; examples are oleic, stearic and palmitic acids. The distillation products must have a substantial acid content, be capable of mixing with mineral oils, and substantially insoluble in water; examples are pine tar, Stockholm tar, rosin pitch and rosin oil. In an example, to a mixture of 25 parts rosin, 7 parts stearic acid, 36 parts petroleum residual pitch and 32 per cent transformer oil is added 14 parts of a hardening paste consisting of equal proportions of transformer oil and calcium hydroxide. The mixture slowly hardens. Five other examples are given. When the fatty acid or destructive distillation product is liquid at normal temperatures the proportion of the liquid vehicle in the mixture may be reduced.