The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 30, 1977
Filed:
Feb. 13, 1975
Geoffrey Vincent Blunt, Cheltenham, EN;
Newton John Hodges, Cheltenham, EN;
Robert James Pragnell, Cheltenham, EN;
Coal Industry (Patents) Limited, London, EN;
Abstract
A cellular material may be made by vulcanizing a mixture containing between 15% and 50% of an ebonite-forming rubber and sufficient vulcanizing agents to form an ebonite with the rubber, between 5% and 87% of a coal digested in pitch, tar or tar oil, between 10% and 40% of a particulate filler and a chemical blowing agent, whereby an ebonite structure is formed, so that, during the vulcanization, the chemical blowing agent decomposes or reacts to produce a gas, the viscosity of the composition during the production of the gas increasing whereby cells are retained in the composition. The digested coal has a penetration, converted to a Ring and Ball softening point of 85.degree. C, of between 10 and about 45. Cellular plastics material produced by this process may contain at least 25% by volume of closed cells.