| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 549274000 | Plural ring oxygens in the lactone ring | 30 |
| 20100041902 | Cyclic alkyl substituted glycolides and polylactides therefrom - Cyclic alkyl, particularly cyclohexyl, substituted glycolides and polylactides are described. The polylactides have a high glass transition temperature and improved clarity. | 02-18-2010 |
| 20100099893 | PURIFICATION OF LACTIDE RICH STREAMS - A method for the purification or recovery of lactide rich streams by the combination of a suspension-based melt crystallization process with a subsequent separation of the pure lactide crystals in a wash column is disclosed. | 04-22-2010 |
| 20100113806 | PRODUCTION OF CYCLIC DIESTERS OF ALPHA-HYDROXYACIDS - The raw material used in most process for the production of cyclic diesters of alpha—hydroxiacids, such as Lactide and Glycolide, is a 10% solution of Hydroxyacid. During the evacuation of the solution and condensation reaction water, the organic molecules may be damaged. The present process is characterized by the use of reactants that bring as little water as possible to the reactor. In particular, for the production of Lactide, the main reactant may be anhydrous Calcium Lactate, that will react at about room temperature, for instance, with Sulfuric Anhydride, to give a solid mixture of Lactide, Calcium Sulfate Dihydrate and Calcium Sulfate Hemihydrate. Partial dehydration of the Dihydrate under mild temperature is followed by distillation of the Lactide out of the remaining powder of Calcium Sulfate Hemihydrate, and desublimation of the Lactide. Purification of the Lactide is done in situ in the desublimator. | 05-06-2010 |
| 20100160650 | Stable lactide particles - The present invention is directed to stable lactide particles, more specifically lactide particles which are stable enough to be stored and transported at room temperature and have a quality high enough for use as starting material for polylactic acid. The lactide particles have a surface/volume ratio of the particle is lower than 3000. Preferably the lactide in the particle has an optical purity of at least 95%. The lactide particles are prepared by subjecting lactide to a shaping step comprising extrusion, pastillation, prilling, tabletting, or flaking. | 06-24-2010 |
| 20100168446 | METHOD FOR PURIFICATION OF CYCLIC ESTER - A method of purifying a cyclic ester, comprising: mixing a co-distillated liquid comprising a cyclic ester produced by heating depolymerization of a hydroxycarboxylic acid oligomer in the presence of a depolymerization solvent and the depolymerization solvent with an organic solvent for washing which is mutually soluble with the depolymerization solvent and has a lower boiling point than the cyclic ester; subjecting the resultant mixture liquid to liquid-liquid separation into an organic solvent phase containing the depolymerization solvent and a cyclic ester phase containing the organic solvent; and then evaporating the organic solvent from the cyclic ester phase containing the organic solvent to recover the cyclic ester containing a reduced amount of the depolymerization solvent. As a result, purified cyclic ester is recovered at high heat efficiency, purification efficiency and operation efficiency, from the co-distillate liquid containing the depolymerization solvent and the cyclic ester from the depolymerization system for thermal decomposition of the hydroxycarboxylic acid oligomer in the presence of the depolymerization solvent. | 07-01-2010 |
| 20100267970 | Process for the production of cyclic diesters of alpha-hydroxyacids - Process for the synthesis of a cyclic diester of an alpha-hydroxyacid, comprising the following steps:
| 10-21-2010 |
| 20110190512 | Method of Obtaining Lactide - The present invention relates to a method of obtaining lactide by means of a solvent of the ether class from a mixture that is in liquid form comprising lactide, meso-lactide, and other impurities. | 08-04-2011 |
| 20110263875 | Production Process of Glycolide - The invention provides a production process of glycolide comprising the respective steps of: Step 1 of heating a mixture containing a glycolic acid oligomer and a high boiling polar organic under normal or reduced pressure to reflux the mixture and at that time, conducting a total reflux operation in a reflux time within a range of 0.1 to 20 hours under conditions that substantially the whole amount of a distillate distilled out of a reflux system containing the mixture is refluxed into the reflux system; Step 2 of heating the mixture after the total reflux operation or a mixture obtained by adding the high boiling polar organic solvent to a glycolic acid oligomer component recovered from the mixture after the total reflux operation to conduct depolymerization; and Step 3 of collecting glycolide from a co-distillate. | 10-27-2011 |
| 20110288312 | METHOD FOR STORING AND TRANSPORTING CYCLIC DIESTERS - The present invention relates to a method for storing and/or transporting intramolecular cyclic esters (lactones), in particular lactide. | 11-24-2011 |
| 20120095240 | RECOVERY OF LACTIC ACID VALUES FROM A MESO-LACTIDE STREAM - Lactic acid equivalents are recovered from a starting lactide stream by catalytically racemizing a portion of the lactide in the stream at a temperature of 180° C. or below. This increases the proportion of two species of lactide (i.e., at least two of S,S-, R,R- or meso-lactide) at the expense of the third species. The racemized mixture so obtained can be separated to recover some or all of one or more of the lactide species from the remaining lactide species, by a process such as melt crystallization or distillation. Impurities in the starting lactide stream usually are retained mostly in the remaining meso-lactide, so a highly purified S,S- and/or R,R-lactide stream can be produced in this manner. Such a purified S,S- and R,R-lactide stream is suitable for polymerization to form a polylactide. | 04-19-2012 |
| 20120116100 | SYSTEM AND METHOD FOR PRODUCING POLYHYDROXYCARBOXYLIC ACID - An object of the present invention is to provide a method and a system by which hydroxycarboxylic acid cyclic dimers are efficiently generated, allowing high yields of high-quality polyhydroxycarboxylic acid to be obtained. The method for synthesizing polyhydroxycarboxylic acid comprises a depolymerization step for depolymerizing hydroxycarboxylic acid oligomers to produce hydroxycarboxylic acid cyclic dimers, wherein, in the depolymerization step, a reaction solution is heated via heat transfer from a heat medium passage under reduced pressure while the reaction solution is being flowing through a horizontally provided reaction solution passage. | 05-10-2012 |
| 20120142945 | RECOVERY METHOD OF HIGHLY PURE LACTIC ACID AND ALKYL LACTATE - A method for recovery of highly pure alkyl lactate and lactic acid is provided, which includes a step 1 for producing source liquid comprising lactic acid or ammonium lactate; a step 2 for dehydrating the source liquid product of step 1; a step 3 for producing liquid mixture by sequentially adding and stirring alcohol and acid solution to the dehydrated source liquid; a step 4 for separating and removing ammonium salt precipitation from the liquid mixture of step 3; a step 5 for producing alkyl lactate from ammonium salt-free liquid mixture by esterification reaction; and a step 6 for separating alcohol and alkyl lactate by distillation from the mixture of step 5. | 06-07-2012 |
| 20120149920 | Method for the production of a mixture of lactide derivatives - A mixture of cyclic diesters derived from lactic acid and in cases a mixture of a racemate of dilactide may be produced in several different processes. In some instances, the process can thereby start from the corresponding alpha-hydroxycarboxylic acids, the corresponding cyclic diesters or oligomers of the corresponding alpha-hydroxycarboxylic acids. | 06-14-2012 |
| 20120165554 | METHOD FOR STEREOSPECIFICALLY RECYCLING A PLA POLYMER MIXTURE - The present invention relates to a method for the stereospecific chemical recycling of a mixture of polymers based on polylactic acid PLA, in order to reform the monomer thereof or one of the derivatives thereof. The latter may enter the traditional lactate market or once again serve as a raw material for synthesising PLA. | 06-28-2012 |
| 20120289713 | METHOD FOR PRODUCING GLYCOLIDE - A method for producing glycolide, including the steps of: heating a mixture containing a glycolic acid oligomer, a high-boiling point polar organic solvent having a boiling point of 230 to 450° C., and a tin compound under normal pressure or reduced pressure until a temperature at which the glycolic acid oligomer is depolymerized, to thereby dissolve the glycolic acid oligomer in the high-boiling point polar organic solvent; heating a solution, in which the glycolic acid oligomer is dissolved, under normal pressure or reduced pressure until a temperature at which the glycolic acid oligomer is depolymerized, to thereby form glycolide by depolymerization of the glycolic acid oligomer in the solution; and co-distilling off the high-boiling point polar organic solvent and the formed glycolide from a depolymerization reaction system. | 11-15-2012 |
| 20130023674 | Lactide Production from Thermal Depolymerization of PLA with applications to Production of PLA or other bioproducts - Methods and systems are disclosed for producing lactide, which can be used for PLA production or other valuable bioproducts. PLA is heated to undergo thermal depolymerization to recover lactide. The lactide can be used for PLA production or other valuable bioproducts. | 01-24-2013 |
| 20130060051 | Process For The Preparation Of L-Lactide Of High Chemical Yield And Optical Purity - A process for the synthesis of 100% optically pure L(+)-lactide catalyzed by zinc and tin metal catalysts of less than 150 micron particle size is disclosed. The L-lactide obtained was further purified to obtain lactide of 100% optical purity and acid impurities less than 10 meq/kg. | 03-07-2013 |
| 20130116448 | Process for the manufacture of a cyclic diester of an alpha-hydroxyacid - Process for the manufacture of a cyclic diester of an alpha-hydroxyacid comprising heating the alpha-hydroxyacid at a temperature from 100 to 250° C. in the presence of at least one polyol and of at least one catalyst selected from the group consisting carboxylates and alkoxides of Ti, Zr, Al and Sn. | 05-09-2013 |
| 20130261316 | NEPRILYSIN INHIBITORS - In one aspect, the invention relates to compounds having the formula: | 10-03-2013 |
| 20130267716 | METHOD OF PREPARING LACTIDE FROM LACTATE - The present invention provides a method of preparing lactide with a high yield from lactate obtained through a fermentation process. In certain embodiments, the invention provides a method of preparing high-purity lactide with a high yield, wherein the method comprises treating lactate with a specific solvent, using a catalyst, and phase-separating the resultant. In accordance with the invention, costs for manufacturing polylactic acid can be considerably reduced. | 10-10-2013 |
| 20140024842 | PREPARATION OF 3,5-DIOXO HEXANOATE ESTER IN TWO STEPS - The invention discloses a method for the preparation of tert-butyl 6-chloro-3,5-dioxohexanoate from Meldrum's acid derivative and its use for the preparation of tert-butyl(4R,65)-(6-hydroxymethyl-2,2-dimethyl-1,3-dioxan-4-yl)acetate (BHA), Rosuvastatin and Atorvastatin. | 01-23-2014 |
| 20140031566 | RECOVERY OF LACTIC ACID VALUES FROM A MESO-LACTIDE STREAM - Lactic acid equivalents are recovered from a starting lactide stream by catalytically racemizing a portion of the lactide in the stream at a temperature of 180° C. or below. This increases the proportion of two species of lactide (i.e., at least two of S,S-, R,R- or meso-lactide) at the expense of the third species. The racemized mixture so obtained can be separated to recover some or all of one or more of the lactide species from the remaining lactide species, by a process such as melt crystallization or distillation. Impurities in the starting lactide stream usually are retained mostly in the remaining meso-lactide, so a highly purified S,S- and/or R,R-lactide stream can be produced in this manner. Such a purified S,S- and R,R-lactide stream is suitable for polymerization to form a polylactide. | 01-30-2014 |
| 20140187798 | METHOD FOR PREPARING LACTIDE USING AN IONIC SOLVENT - Disclosed is a method for preparing lactide by using a solvent. According to the method, since an ionic liquid is used as a solvent in a second step in the course of preparing lactide, it is possible to secure mobility of the resulting reactant, and decrease a reaction temperature. In addition, the ionic liquid absorbs moisture generated during the reaction, and thus prevents degradation of lactide which is susceptible to moisture. Furthermore, to the present method allows for the preparation of lactide successively through the continuous supply of lactic acid oligomers. Because the use of an ionic liquid minimizes the contamination of a reactive group with by-products, the use of a solvent for reactor washing is unnecessary. Further, owing to a high boiling point of the ionic liquid, the ionic liquid can be easily harvested and recycled. | 07-03-2014 |
| 20140343298 | METHOD FOR PRODUCING GLYCOLIDE - A method for producing glycolide comprises depolymerizing a glycolic acid oligomer in the presence of a phenol-based antioxidant. | 11-20-2014 |
| 20150065732 | METHOD FOR PREPARING REFINED LACTIDE FROM RECOVERED POLYLACTIC ACID - A method for preparing lactide from recovered polylactic acid, the method including the following steps: A. pretreating the recovered polylactic acid; B. extruding the treated polylacitc acid from a twin screw extruder to yield a polylacitc acid melt, and introducing the polylacitc acid melt to a pre-depolymerization kettle; C. carrying out a chain scission reaction to break molecular chains in the polylactic acid melt and to decrease the number-average molecular weight of the polylactic acid melt to below 5000; D. conducting depolymerization reaction to yield a crude lactide; and E. purifying the crude lactide and crystallizing the purified lactide. | 03-05-2015 |
| 20150376159 | Process for Preparing Cyclic Esters and Cyclic Amides - A process for preparing a cyclic ester or a cyclic amide includes contacting hydroxycarboxylic acid and/or amino-carboxylic acid, an ester thereof, or a salt thereof, with acidic zeolite. The hydroxycarboxylic acid is a 2- or 6-hydroxycarboxylic acid, and the amino carboxylic acid is a 2- or 6-amino-carboxylic acid. The zeolite may include two or three interconnected and non-parallel channel systems, in which a channel system includes 10- or more-membered ring channels, and in which a framework Si/X | 12-31-2015 |
| 20160002196 | METHOD FOR PRODUCING GLYCOLIDE - A method for producing glycolide (GL) by heating a glycolic acid oligomer (GAO) to depolymerize the GAO. The method for producing GL comprises: a step 1 of heating a mixture containing a GAO having a terminal COOH concentration of 400 eq/t or less and a polar organic solvent to a GAO depolymerization temperature under ambient pressure or reduced pressure; a step 2 of continuing the heating at the temperature for depolymerizing of the GAO and then codistilling out the produced GL and the solvent from the depolymerization reaction system to the outside the reaction system; and a step 3 of obtaining GL from the codistillation product. In the method for producing GL, the GAO is preferably prepared by a GAO production method which comprises a step of condensing glycolic acid (GA) and a dehydration step of continuing the heating together with a polar organic solvent or a depolymerization reaction solution to allow the GA condensation reaction to continue. | 01-07-2016 |
| 20160002197 | METHOD FOR PRODUCING GLYCOLIDE - A method for producing a GL comprising: (I) a heating step of heating a mixture either under normal pressure or reduced pressure at a temperature at which a polyglycolic acid (PGA) undergoes depolymerization, the mixture containing the PGA and a polyethylene glycol ether which is represented by the formula: X—O—(—CH | 01-07-2016 |
| 20160039782 | TECHNOLOGICAL METHOD FOR SYNTHESIS OF OPTICALLY PURE L-/D-LACTIDE CATALYZED BY BIOGENIC GUANIDINE - A technological method for synthesizing optically pure L-/D-lactide by using a biogenic guanidine catalysis method. The method of the present invention comprises: by using biogenic guanidine creatinine (CR) as a catalyst and L-/D-lactic acid (90% of mass content) as a raw material, synthesizing optically pure L-/D-lactide by using a reactive reduced pressure distillation catalysis method. The method of the present invention has advantages that the used catalyst is biogenic guanidine creatinine and free of toxicity, metal, and cytotoxicity; the synthesized lactide is high in optical purity (the specific rotation of the L-lactide [α]25 D=−276˜−280, and the specific rotation of the D-lactide [α]25 D=280), and does not contain any metal; the amount of the catalyst used in reaction is low, the technological process is simplified (a process for rectifying and purifying a crude lactide product by using a conventional method is avoided); and the technological method is simple and convenient to operate and easy in industrial implementation. | 02-11-2016 |
| 20160068505 | Process for Recovering and Improving Production of Meso-Lactide from a Crude Lactide Containing Stream - A process for the recovery and production of meso-lactide from a crude lactide containing stream may include subjecting a starting crude lactide stream to a first distillation step to obtain: a top stream mainly containing meso-lactide; a bottom stream; and a side stream mainly containing L-lactide and meso-lactide. The process may include recovering the side stream and subjecting the side stream to a melt crystallization step to obtain: a first purified stream mainly containing L-lactide; and a drain stream mainly containing meso-lactide and L-lactide. The process may include recovering the top stream and drain stream, and subjecting the top stream and drain stream to a second distillation step to obtain a second purified stream containing L-lactide and meso-lactide. | 03-10-2016 |
