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US 4,045,380 AGranted
Cellular material
AssigneeCoal Industry (Patents) Limited
InventorsGeoffrey Vincent Dallow Blunt, Newton John Hodges, Robert James Pragnell
Life of this patent
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AssigneeCoal Industry (Patents) Limited
InventorsGeoffrey Vincent Dallow Blunt, Newton John Hodges, Robert James Pragnell
Estimating the term…
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.
A process for the production of a cellular material by vulcanizing a mixture containing between 9 and 50% by weight of a mixture of a rubber together with vulcanizing agents to form an ebonite with the rubber, between 20% and 70 by weight of a coal digested in pitch, tar or tar oil, between 10% and 40% of a particular 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 increasng whereby at least 25% by volume of closed cells are retained in the composition wherein the digested coal has a penetration converted to a Ring and Ball softening point of 85.degree. C, of between 10 and about 45.
A cellular plastics material containing between 20% and 70% by weight of coal digested in pitch, tar or tar oil, and between 9 and 50% by weight of an ebonite vulcanized rubber matrix and between 10% and 40% of a particulate filler and including at least 25% by volume of closed cells, in which the digested coal has a penetration, converted to a Ring and Ball softening point of 85.degree. C, of between 10 and about 45.
Dependencies are inferred from the claim text.