# US 5,703,160 A · Biodegradable moulding compositions comprising a starch, a biodegradable polyester, and a salt of a hydroxycarboxylic acid > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,703,160 A - Document ID: US5703160A - Status: Granted - Kind: A - Application number: 08/091,368 - Filed: 1993-07-15 - Granted: 1997-12-30 - Earliest claimed: 1992-07-15 - Assignees: Solvay SA; Roquette Freres - Inventors: Claude Dehennau; Thierry Depireux; Guy Fleche; Serge Gosset; Didier Videau - Web page: https://patentgrep.com/patent/US5703160A ## CPC - C08L 3/00: Compositions of starch, amylose or amylopectin or of their derivatives or degradation products - C08K 5/098: Metal salts of carboxylic acids - C08L 3/02: Starch; Degradation products thereof, e.g. dextrin - C08L 67/04: Polyesters derived from hydroxycarboxylic acids, e.g. lactones (C08L67/06 takes precedence) - C08L 2201/06: Biodegradable - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) ## Abstract Disclosed is a thermoformable composition characterized in that it contains at least one starchy compound, at least one biodegradable polyester and at least one salt of hydroxycarboxylic acid. ## Claims ### Claim 1 A biodegradable thermoformable composition comprising: a) at least one starchy compound; b) at least one biodegradable polyester; and c) at least one salt of an hydroxycarboxylic acid. ### Claim 2 (depends on 1) The composition of claim 1 wherein the at least one starchy compound is a natural starch. ### Claim 3 (depends on 1) The composition of claim 1 wherein the at least one starchy compound is a modified starch. ### Claim 4 (depends on 1) The composition of claim 1 wherein the at least one starchy compound is a modified starch selected from the group consisting of destructured starch, plasticized destructured starch, pregelled starch, and plasticized pregelled starch. ### Claim 5 (depends on 1) The composition of claim 1 wherein the at least one starchy compound is a modified starch selected from the group consisting of: etherified starch, esterified starch, cross-linked starch, oxidized starch, alkaline treated starch, acid hydrolyzed starch, enzyme hydrolyzed starch, and a combination thereof. ### Claim 6 (depends on 1) The composition of claim 1 wherein the at least one biodegradable polyester is polylactic acid, polyglycolic acid, polyhydroxybutyric acid, polyhydroxypropionic acid, polyhydroxyvaleric acid, a salt thereof, or a copolymer thereof. ### Claim 7 (depends on 1) The composition of claim 1 wherein the at least one biodegradable polyester is polylactic acid or a polylactate. ### Claim 8 (depends on 1) The composition of claim 1 wherein the at least one biodegradable polyester is sodium polylactate. ### Claim 9 (depends on 1) The composition of claim 1 wherein the dry-weight ratio of the at least one starchy compound to the at least one biodegradable polyester is between approximately 99/1 and 1/99. ### Claim 10 (depends on 1) The composition of claim 1 wherein the dry-weight ratio of the at least one starchy compound to the at least one biodegradable polyester is between 90/10 and 10/90. ### Claim 11 (depends on 1) The composition of claim 1 wherein the dry-weight ratio of the at least one starchy compound to the at least one biodegradable polyester is between 80/20 and 50/50. ### Claim 12 (depends on 1) The composition of claim 1 wherein the dry-weight ratio of the at least one starchy compound to the at least one biodegradable polyester is between 99/1 and 70/30. ### Claim 13 (depends on 1) The composition of claim 1 wherein the dry-weight ratio between the at least one starchy compound and the at least one biodegradable polyester is between 98/2 and 80/20. ### Claim 14 (depends on 1) The composition of claim 1 wherein the dry-weight ratio of the at least one starchy compound to the at least one biodegradable polyester is between 98/2 and 40/60. ### Claim 15 (depends on 1) The composition of claim 1 comprising 5-60 weight percent of the at least one starchy compound, 30-94 weight percent of the at least one thermoplastic polyester, and 1-10 weight percent of the at least one salt of an hydroxycarboxylic acid. ### Claim 16 (depends on 1) The composition of claim 1 wherein the at least one starchy compound has an amylopectin content of at least 70 weight percent. ### Claim 17 (depends on 1) The composition of claim 1 further comprising water. ### Claim 18 (depends on 1) The composition of claim 1 wherein the at least one starchy compound is in a partially molten state. ### Claim 19 (depends on 1) The composition of claim 1, wherein said at least one salt of an hydroxycarboxylic acid is selected from the group consisting of monohydroxy/monocarboxylic acid salts, polyhydroxy/monocarboxylic acid salts, and a combination thereof. ### Claim 20 (depends on 19) The composition of claim 19, wherein said at least one salt of an hydroxycarboxylic acid is an alkali or alkaline-earth metal salt of lactic acid, gluconic acid, maltobionic acid, lactobionic acid, or glyceric acid. ### Claim 21 (depends on 19) The composition of claim 19, wherein said at least one salt is an alkali or alkaline-earth metal salt of lactic acid. ### Claim 22 (depends on 19) The composition of claim 19, wherein said at least one salt is sodium lactate. ### Claim 23 (depends on 1) The composition of claim 1, further comprising at least one adjuvant selected from the group consisting of urea and hydrogenated sugars. ### Claim 24 (depends on 1) The composition as claimed in claim 1, further comprising at least one adjuvant selected from the group consisting of sorbitol, mannitol, maltitol, and lactitol. ### Claim 25 (depends on 1) The composition of claim 1, wherein the at least one biodegradable polyester is a thermoplastic aliphatic polyester or copolyester in which the ester functional groups are separated by linear or branched hydrocarbon groups containing more than three carbon atoms. ### Claim 26 (depends on 1) The composition of claim 1, wherein the at least one biodegradable polyester is a lactone homopolymer or copolymer. ### Claim 27 (depends on 1) The composition of claim 1, wherein the at least one biodegradable polyester is a poly-.epsilon.-caprolactone. ### Claim 28 (depends on 1) The composition of claim 1, wherein the at least one biodegradable polyester is a polyester or copolyester obtained from hydroxyalkanoates. ### Claim 29 (depends on 4) The composition of claim 4 wherein the plasticized starch includes a maximum of 50% by weight of the plasticizer. ### Claim 30 (depends on 1) The composition of claim 1, wherein the hydroxycarboxylic acid salt is an alkali or alkaline-earth metal salt obtained from lactic, glycolic, hydroxybutyric, citric, isocitric, malic, tartronic, gluconic, maltobionic, lactobionic, glucuronic, glyceric, ribonic, xylonic, galactonic, mesovalonic, tartaric, mesoxalic or glucaric acids or a combination thereof. ### Claim 31 A process for making a biodegradable thermoformed article comprising thermoforming a composition including a) at least one starchy compound in a destructured or partially molten state, b) at least one biodegradable polyester, and c) at least one salt of an hydroxycarboxylic acid. ### Claim 32 (depends on 31) The process of claim 31, wherein the composition is made by combining the at least one starchy compound in a destructured or partially molten state with the at least one biodegradable polyester and the at least one salt of an hydroxycarboxylic acid. ### Claim 33 (depends on 31) The process as claimed in claim 31, wherein the composition is made by combining the at least one starchy compound, the at least one biodegradable composition, and the at least one salt of an hydroxycarboxylic acid followed by treatment to effect the at least one starchy compound in a destructured or partially molten state. ### Claim 34 (depends on 1) A biodegradable thermoformed article produced from the composition of claim 1. ### Claim 35 (depends on 4) A biodegradable thermoformed article produced from the composition of claim 4. ### Claim 36 (depends on 5) A biodegradable thermoformed article produced from the composition of claim 5. ### Claim 37 (depends on 15) A biodegradable thermoformed article produced from the composition of claim 15. ### Claim 38 (depends on 34) The biodegradable thermoformed article of claim 34 having a maximum loss factor, tan delta, at a temperature not exceeding 150.degree. C. ### Claim 39 (depends on 1) The biodegradable composition of claim 1, wherein the at least one starchy compound is a modified starch selected from the group consisting of destructured starch or partially molten starch. ### Claim 40 (depends on 39) A biodegradable thermoformed article produced from the composition of claim 39. ### Claim 41 A biodegradable thermoformable composition comprising: a) at least one starchy compound; b) at least one biodegradable polyester; and c) at least one salt of an hydroxycarboxylic acid selected from the group consisting of monohydroxy/monocarboxylic acid salts, polyhydroxy/monocarboxylic acid salts, and a combination thereof. ### Claim 42 (depends on 41) The composition of claim 41, wherein the at least one salt of an hydroxycarboxylic acid is an alkali or alkaline-earth metal salt of lactic acid, gluconic acid, maltobionic acid, lactobionic acid, or glyceric acid. ### Claim 43 (depends on 41) The composition of claim 41, wherein the at least one salt of an hydroxycarboxylic acid is an alkali or alkaline-earth metal salt of lactic acid. ### Claim 44 (depends on 41) The composition of claim 41, wherein the at least one salt of an hydroxycarboxylic acid is sodium lactate. ### Claim 45 (depends on 41) A biodegradable thermoformed article produced from the composition of claim 41.