GB977103A - Thermosetting hydrocarbonaceous resinous materials - Google Patents

Abstract

A polymerizable composition comprises a partially cured thermosetting hydrocarbonaceous material formed from hydrocarbon pitch and having a softening point between 100 degrees and 250 degrees and 25-60% acetone- or benzenesoluble components together with a compatible, thermosetting resin. The partially cured hydrocarbonaceous material may be prepared by treating pitch with an oxidising agent, e.g. dinitrobenzene or dinitrotoluene, or with phosphorus pentoxide, boron trioxide or red iron oxide. Thermosetting resins mentioned are phenol-aldehyde resins; phenolaldehyde resins modified, e.g. with polyvinyl butyral, rosin, drying oils, or p-tert.-butyl phenol; melamine-aldehyde, urea-aldehyde, and guanidine-aldehyde condensates; alkyd resins and epoxy resins. A list of phenols suitable for preparing the phenol-aldehyde resin is given and includes cashew nut shell oil. Aldehydes mentioned for condensates with the phenols are formaldehyde, acetaldehyde and furfural. Methylene-bridge donors, e.g. hexamethylene tetramine, may be used with the phenol-aldehyde condensates. The compositions may include fillers, e.g. graphite, clay, asbestos, glass filament or cloth, mica, carbon, metal particles, borytes, alumina, titania, silica, nylon, polyesters, carbonaceous fibres produced by carbonising organic fibres, wood floor, or shell flour. In examples (1) coal tar pitch was heated with dinitrobenzene, and the partially cured product was mixed with a phenol-formaldehyde condensate and with hexamethylenetetramine and cured at 260 DEG C. for 4 hours. The cured product was ground, mixed with asbestos, barytes and phenolic resin and pressed to form a brake lining (2) and (3). The phenol-formaldehyde condensate of example (1) was modified by reaction with cashew nut shell liquid. (4) and (11) Coal tar pitch was heated with phosphorus pentoxide and the product cured together with the phenolformaldehyde condensate of example (1). In examples (5) and (12) the pitch was treated with boron trioxide. In example (6) cashew nut shell liquid, formaldehyde and cresol sulphonic acid were condensed in presence of a partially cured thermosetting material formed from pitch and the product thermoset. (7) The thermosetting resins employed with the pitch product of example (1) were (a) urea formaldehyde resin, (b) melamine-formaldehyde resin and (c) epoxy resin.