polylactide latest patent

BRUSSELS BIOTECH (BE) 2004 年 2 月 13 Publication Date of World Patent WO 2004 014889, reported polylactic acid, its independence items include the following: ⑴ lactic acid was prepared as follows: (a) evaporation of lactic acid or lactic acid derivatives a molecular weight of 400-2000 solution preparation, the total acidity of lactic acid equivalent 119-124.5%, optical purity equal to 90-100% buffered lactic acid oligomers; (b) the oligomer depolymerization catalyst is added to the depolymerization reaction is prepared to give a lactic acid-rich gas phase and a liquid phase rich in oligomers; (c) condensing vapor to obtain a liquid crude acid; (d) extracting the crude acid crystals; (e) separation and to obtain a rich exhaust crystals lactic acid crystals wet cake; (f) drying the wet cake to obtain pre-purification of lactic acid; and (g) pre-purification of lactic acid obtained crystalline residue acidity than 10meq/kg, the water content of less than 200ppm and meso-lactic acid content of less than 1% purification of lactic acid; ⑵ polymer obtained above polylactic acid was obtained.
2004 BOTELHO T and other published patent WO 2004 057008-A1, reported a confectionery packaging material for preparation of the polylactic acid is mainly obtained by the fermentation method, examples of specific methods reported as follows: the culture medium ( 451) (including whey, milk protein and other nutrients, such as salts and cysteine) and heated to 70 ℃ for 45 minutes and then cooled to 45 ℃. Adding Lactobacillus helveticus (9 g) and Flavourzyme (RTM) (A) (26.5 g). Batch fermentation 9 hours,potassium lactate, lactose and Flavourzyme (RTM) of fresh broth. PH was adjusted to 5.75 with ammonia gas, bio-density control at 7-8%, the fermentation process continuous aeration, aeration rate of 1 liter / min. During the 34 days of fermentation period dilution rate 0.15-0.3 / hour. Lactate solution in the effluent of 4% dilution rate of 0.3 / h under the yield was 12 g / liter. Hour. Lactic acid effluent and a chelating ion exchange resin separation and then after two successive electrodialysis recovery of 85-90%.
HANZSCH BERND other August 21, 2003 U.S. Patent US 2003 158360, reported a method for preparing polylactic acid, the following steps: fermentation of starch obtained produce lactic acid, by ultrafiltration, nano filtration and / or electrodialysis ultrapure zinc lactate, concentrated acid, to prepare the prepolymer, the ring is double resolve polylactic acid, lactic acid purification double, double ring-opening and deprotection monomeric lactic acid polymer obtained polylactic acid.SHIMADZU CORP 2002 年 10 月 15 Publication Date of JP 2002 300898, reported a production of lactic acid and polylactic acid. Specific methods: ⑴ synthesis using ammonium lactate lactate; ⑵ butyltin outside in addition to the presence of a catalyst, the polycondensation of lactic acid ester, an average molecular weight less than 15000mol.wt synthesis of polylactic acid (lactic acid prepolymer); ⑶ solution obtained copolymerized lactic acid; The method further comprises ring-opening polymers polylactic acid.
SHIMADZU CORP, OHARA H, TOYOTA JIDOSHA KK, ITO M and SAWA S 2002 年 8 月 8 Publication Date Patent WO 2002 60891-A, reported for the production of biodegradable plastics, and polylactic acid preparation method of the patent One embodiment of the method reported as follows: fermentation of L-ammonium lactate and ethanol at 90-100 ℃ the reaction, separation, collection of alcohol; 120 ℃ the removal reaction of the water; obtained was purified by distillation of ethyl lactate In dioctyltin 160 ℃ polycondensation in the presence of ethyl lactate and ethanol off. The resulting reaction solution was distilled at 200 ℃ acid obtained in a yield of 99.2%. In the polymerization in the presence of lactic acid dioctyltin of lactic acid. NATL INST OF ADVANCED INDUSTRIAL SCIENCE TECHNOLOGY METI, KONAN KAKO KK and TOKIWA YUTAKA2001 August 21, disclosed in Japanese Patent JP 2001 224392, reported the use of enzymes instead of the organic metal catalyst polylactic acid.