# US 5,352,716 A · Degradable synthetic polymeric compounds > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,352,716 A - Document ID: US5352716A - Status: Granted - Kind: A - Application number: 07/991,320 - Filed: 1992-12-16 - Granted: 1994-10-04 - Earliest claimed: 1992-12-16 - Assignees: Ecostar International, L.P. - Inventors: Graham M. Chapman; Robert H. Downie - Web page: https://patentgrep.com/patent/US5352716A ## CPC - C08K 5/0033: {Additives activating the degradation of the macromolecular compound} - C08K 5/098: Metal salts of carboxylic acids - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) ## Abstract A synthetic thermoplastic polymeric compound is structurally stable during its useful life and which upon introduction into a suitable environment, degrades under chemical, photochemical and biodegradation mechanisms into innocuous products. Stabilizers may be incorporated into the thermoplastic polymer to help maintain the structural and functional integrity through the useful life of the product. Degradation is then brought about by the synergistic interaction of the biodegradable component, an oxidizable component, transition metal additives and an aromatic ketone incorporated into the thermoplastic polymer. In the degradation process, the biodegradable component is metabolized to expose the thermoplastic polymer surface to chemical attack. In addition, the oxidizable component in conjunction with the catalytic system effects oxidative breakdown of the thermoplastic polymer to give lower molecular weight fragments that are susceptible to enzymatic attack in the decomposition environment. The result is the complete breakdown of the thermoplastic polymer into innocuous products. The chemical, photochemcial, and biodegradation mechanisms comprising the degradation process occur both sequentially and simultaneously in cooperative, synergistic action to bring about the desired result. ## Claims ### Claim 1 A synthetic thermoplastic polymeric compound which is degradable into innocuous products under the action of naturally occurring decomposition forces comprised of heat, underwater disposal, and/or microbiological organisms, which comprises: (a) a thermoplastic polymeric component formed of long chain carbon-to-carbon linkages; (b) a biodegradable component mixed with the thermoplastic component, wherein the naturally occurring decomposition forces effect decomposition removal of the biodegradable component to increase the exposure area of the carbon-to-carbon linkages of the thermoplastic polymeric component; (c) an oxidizable component that reacts with the exposed carbon-to-carbon linkages of the thermoplastic component under the action of the naturally occurring forces to sever the linkages and effect degradation of the thermoplastic polymeric component; (d) a first transition metal component that is soluble in the synthetic thermoplastic polymeric compound and which serves as an initiator for the reaction of the oxidizable component; (e) a second transition metal component which acts as a catalyst with the first transition metal component to enhance degradation of the thermoplastic polymeric component; (f) oxidation promoting component which in conjunction with the first and second transition metal components enhances the action of the oxidizable component to degrade the carbon-to-carbon linkages of the thermoplastic polymeric component under the action of the naturally occurring forces; and (g) a non-metal. Containing stabilizing component, wherein the stabilizing component comprises a hindered phenol that retards commencement of the degradation process until the polymeric component is subjected to the naturally occurring decomposition forces. ### Claim 2 (depends on 1) The thermoplastic compound of claim 1 wherein the biodegradable component is a polysaccharide. ### Claim 3 (depends on 1) The thermoplastic compound of claim 1 wherein the oxidizable component generates a peroxide or a hydroperoxide and is selected from the group consisting of a fatty acid, a fatty acid ester, a natural fat, and mixtures thereof. ### Claim 4 (depends on 3) The thermoplastic compound of claim 3 wherein the oxidizable component is present in the composition in an amount of up to about 15%, by weight. ### Claim 5 (depends on 1) The thermoplastic compound of claim 1 wherein the first transition metal component is ferric hydroxy stearate. ### Claim 6 (depends on 1) The thermoplastic compound of claim 1 wherein the second transition metal component is cooper stearate. ### Claim 7 (depends on 1) The thermoplastic compound of claim 1 wherein the oxidation promoting component comprises an aromatic ketone. ### Claim 8 (depends on 7) The thermoplastic compound of claim 7 wherein the aromatic ketone is benzophenone. ### Claim 9 (depends on 8) The thermoplastic compound of claim 8 wherein the benzophenone is present in the compound in an amount of from about 0.01% to about 0.2% by weight. ### Claim 10 (depends on 1) The thermoplastic composition of claim 1 where the hindered phenol is selected from the group consisting of benzenepropanoic acid and 3,5-bis(1,1-dimethyl ethyl)-4-hydroxy-octadecyl ester. ### Claim 11 (depends on 1) The thermoplastic compound of claim 1 wherein the thermoplastic polymeric compound comprises a polar polymer. ### Claim 12 (depends on 11) The thermoplastic compound of claim 11 wherein the thermoplastic polymeric component is selected from the group consisting of polyurethane (PU), polystyrene (PS), polyolefins, ethylene/vinyl acetate-copolymers (EVA), ethylene/vinyl alcohol-copolymer (EVAL), ethylene/acrylic acid-copolymers (EAA), ethylene/methyl acrylate-copolymers (EMAC), ethylene methacrylic acid copolymer (EMAA), ethylene vinyl alcohol (EVAL), polyinyl alcohol (PVOH), ethylene vinyl alcohol carbon monoxide copolymer (EVACO), ethylene butylacrylate (EBAC), polymethyl methacrylate (PMMA) and polyethylene oxide (PEO). ### Claim 13 (depends on 5) The thermoplastic compound of claim 5 wherein the ferric hydroxy stearate consisting of the first transition metal component is present in the compound in an amount of from between about 0.1% to about 0.5% by weight. ### Claim 14 (depends on 6) The thermoplastic compound of claim 6 wherein the copper stearate consisting of the second transition metal component is present in the compound in an amount of from between about 0.005% to about 0.1 by weight. ### Claim 15 (depends on 1) The thermoplastic compound of claim 1 wherein the oxidation promoting component further serves as a photodegradation enhancer for the degradation of the carbon-to-carbon linkages comprising the thermoplastic polymeric component under the action of ultraviolet light and/or sunlight. ### Claim 16 A synthetic thermoplastic polymeric compound which is degradable into innocuous products under the action of naturally occurring decomposition forces comprised f heat, underwater disposal, and/or microbiological organisms, which comprises: (a) a thermoplastic polymeric component formed of long chain carbon-to-carbon linkages; (b) a biodegradable component mixed with the thermoplastic component, wherein the naturally occurring decomposition forces effect decomposition removal of the biodegradable component to increase the exposure area of the carbon-to-carbon linkages of the thermoplastic polymeric component; (c) an oxidizable component that reacts with the exposed carbon-to-carbon linkages of the thermoplastic component under the action of the naturally occurring forces to sever the linkages and effect degradation of the thermoplastic polymeric component; (d) a transition metal component that is soluble in the synthetic thermoplastic polymeric compound and which serves as an initiator for the reaction of the oxidizable component; and (e) a non-metal containing stabilizing component, wherein the stabilizing component comprises a hindered phenol that retards commencement of the degradation process until the polymeric component is subjected to the naturally occurring decomposition forces. ### Claim 17 (depends on 16) The thermoplastic compound of claim 16 further including an oxidation promoting component which in conjunction with the transition metal component enhances the action of the oxidizable component to degrade the carbon-to-carbon linkages of the thermoplastic polymeric component under the action of the naturally occurring forces. ### Claim 18 (depends on 16) The thermoplastic compound of claim 16 wherein the biodegradable component is a polysaccharide. ### Claim 19 (depends on 16) The thermoplastic compound of claim 16 wherein the oxidazable component generates a peroxide or a hydroperoxide and is selected from the group consisting of a fatty acid, a fatty acid ester, a natural fat, and mixtures thereof. ### Claim 20 (depends on 19) The thermoplastic compound of claim 19 wherein the oxidizable component is present in the composition in an amount of up to about 15%, by weight. ### Claim 21 (depends on 16) The thermoplastic compound of claim 16 wherein the transition metal component is ferric hydroxy stearate. ### Claim 22 (depends on 16) The thermoplastic compound of claim 16 wherein the oxidation promoting component comprises an aromatic ketone. ### Claim 23 (depends on 22) The thermoplastic compound of claim 22 wherein the aromatic ketone is benzophenone. ### Claim 24 (depends on 23) The thermoplastic compound of claim 23 wherein the benzophenone is present in the compound in an amount of from about 0.01% to about 0.2% by weight. ### Claim 25 (depends on 24) The thermoplastic compound of claim 24 wherein the hindered phenol is selected from the group consisting of and 3,5-bis(1,1-dimethyl ethyl)-4-hydroxy-octadecyl ester and benzenepropanoic acid. ### Claim 26 (depends on 16) The thermoplastic compound of claim 16 wherein the thermoplastic polymeric component comprises a polar polymer. ### Claim 27 (depends on 25) The thermoplastic compound of claim 25 wherein the thermoplastic polymeric component is selected from the group consisting of polyurethane (PU), polystyrene (PS), polyolefins, ethylene/vinyl acetate-copolymers (EVA), ethylene/vinyl alcohol-copolymer (EVAL), ethylene/acrylic acid-copolymers (EAA), ethylene/methyl acrylate-copolymers (EMAC), ethylene methacrylate acid copolymer (EMAA), ethylene vinyl alcohol (EVAL), polyvinyl alcohol (PVOH), ethylene vinyl alcohol carbon monoxide copolymer (EVACO), ethylene butylacrylate (EBAC), polymethyl methacrylate (PMMA) and polyethylene oxide (PEO). ### Claim 28 (depends on 16) The thermoplastic compound of claim 16 wherein the ferric hydroxy stearate consisting of the transition metal component is present in the compound in an amount of from between about 0.1% to about 0.5% by weight.