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:
Jul. 18, 1978
Filed:
Sep. 16, 1976
Ernest Rudolph Kamens, Tonawanda, NY (US);
Donald Milton Kressin, Glen Burnie, MD (US);
Harold Carl Lange, Grand Island, NY (US);
Ronald Edward MacLeay, Williamsville, NY (US);
Pennwalt Corporation, Phialdelphia, PA (US);
Abstract
Cellular polymeric solids are made by mixing an acidulous or acidic polymerizable medium that is polymerizable and/or cross-linkable by a free radical mechanism (e.g. an unsaturated polyester) with an effective amount of two or more acid sensitive mono- or poly-azo compounds containing the group: ##STR1## wherein Y is an acid sensitive group (e.g. Cl, OH, --OCN, --NCO) which in the presence of an acidulous or acidic polymerizable medium causes sufficient decompsition of the azo compound that gas is released in the medium and during the decomposition the mono- or poly- azo compound promotes polymerization and/or cross-linking of the medium to provide a matrix that is sufficiently polymerized and/or cross-linked that the generated gases cause the matrix to expand, each of the remaining valences being satisfied by an organic radical; provided that any carbon atom that is directly linked to an azo nitrogen, except that of a carbonyl group, has at least two of its remaining three valences satisfied by a carbon to carbon bond or a carbon to hydrogen bond. Preferably, the mixture contains at least two such azo compounds having appreciably different sensitivity to decomposition by acid. The process is especially useful in making foamed flotation structures (e.g. boat hulls).