Abstract: There are provided: a bio-based coating composition which is a bio-based ingredient coating composition in consideration of environment and does not need any expensive ingredient and is also excellent in hydrolysis resistance; and an article coated with the coating composition. The bio-based coating composition is characterized by comprising the following film-forming ingredients: a lactic acid polymer (A) which contains a polyfunctional compound having a hydroxyl group and/or a carboxyl group in a functionality of not less than 3 and lactic acid as essential monomer ingredients and has a specific SP value; and a resin (B) which contains a hydroxyl group and/or a carboxyl group and has a specific SP value; wherein the difference (?SP) between the SP values of the lactic acid polymer (A) and the resin (B) is in the range of 0.2 to 4.0. The coated article is characterized by being obtained by being coated with the aforementioned coating composition.

Abstract: There are provided a photosetting type bio-based coating composition and its coated article, wherein the coating composition has a sufficient hydrolysis resistance and a sufficient crosslinking density so as to be excellent in such as long-term stability, and is inexpensive, and is applicable also to an aqueous solvent. The photosetting type bio-based coating composition according to the present invention is characterized by comprising: a bio-based photopolymerizable compound as a film-forming ingredient which compound has at least one lactic acid unit and at least one photopolymerizable group together in a molecule; and a photopolymerization initiator. The coated article according to the present invention is characterized by being obtained by being coated with the aforementioned coating composition.

Abstract: There are provided: a bio-based coating composition which is a bio-based ingredient coating composition in consideration of environment and does not need any expensive ingredient and is also excellent in hydrolysis resistance; and an article coated with the coating composition. The bio-based coating composition is characterized by comprising the following film-forming ingredients: a lactic acid polymer (A) which contains a polyfunctional compound having a hydroxyl group and/or a carboxyl group in a functionality of not less than 3 and lactic acid as essential monomer ingredients and has a specific SP value; and a resin (B) which contains a hydroxyl group and/or a carboxyl group and has a specific SP value; wherein the difference (?SP) between the SP values of the lactic acid polymer (A) and the resin (B) is in the range of 0.2 to 4.0. The coated article is characterized by being obtained by being coated with the aforementioned coating composition.

Abstract: The present invention is envisaged to provide an apparatus and a process for synthesizing lactide, according to which the water content in the produced lactide can be reduced. In operation of the system, lactic acid oligomer discharge valve 10 is closed, allowing transfer of lactic acid to its polycondensing apparatus 2, and concentration and polycondensation of lactic acid are advanced by heating and evacuation, with the produced water being evaporated. Lactic acid, lactic acid oligomer and lactide are removed from the produced gaseous body by condenser 11 and refluxed to the polycondensing apparatus, and then water content in the gaseous body is measured by pressure gauge 12. After confirming that the water content is below a specified value, lactic acid oligomer discharge valve 10 is opened to allow transfer of the lactic acid oligomer, said oligomer being depolymerized to produce gaseous lactide, which is condensed and recovered.

Abstract: According to the present invention, a process for consistently producing lactide from ammonium lactate obtained by lactic fermentation, and a process for consistently producing polylactic acid from ammonium lactate obtained by lactic fermentation, are provided. A process for producing lactide, which comprises the steps of: (1) synthesizing lactate ester from ammonium lactate obtained by lactic fermentation; (2) polycondensing the lactate ester in the presence of a catalyst other than monobutyltin, whereby polylactic acid with a weight-average molecular weight of less than 15,000 (lactic acid prepolymer) is synthesized; and (3) depolymerizing the polylactic, whereby lactide is produced. A process for producing polylactic acid, which comprises the additional step of (4) ring-opening polymerizing said lactide, whereby polylactic acid is obtained. A process for producing lactate ester from ammonium lactate obtained by lactic fermentation.

Abstract: According to the present invention, a process for consistently producing lactide from ammonium lactate obtained by lactic fermentation, and a process for consistently producing polylactic acid from ammonium lactate obtained by lactic fermentation, are provided. A process for producing lactide, which comprises the steps of: (1) synthesizing lactate ester from ammonium lactate obtained by lactic fermentation; (2) polycondensing the lactate ester in the presence of a catalyst other than monobutyltin, whereby polylactic acid with a weight-average molecular weight of less than 15,000 (lactic acid prepolymer) is synthesized; and (3) depolymerizing the polylactic, whereby lactide is produced. A process for producing polylactic acid, which comprises the additional step of (4) ring-opening polymerizing said lactide, whereby polylactic acid is obtained. A process for producing lactate ester from ammonium lactate obtained by lactic fermentation.

Abstract: A crude lactide in a solid state or in an at least partially molten state is brought into contact with ethanol to form a slurry mixture, and then a solid form this slurry mixture is separated to yield a purified lactide having a high purity. A crude lactide is recrystallized from a non-denatured or denatured ethanol to obtain a lactide for a food additive. A lactide is applied widely to food additives. A coagulating agent for an animal and/or vegetable protein containing an optically active lactide as a main component, a food foaming agent containing a lactide as a main component, a food preservative containing a lactide as a main component and a pH regulating agent containing a lactide as a main component are provided.

Abstract: A method for producing a polylactic acid includes the steps of (a) crystallizing polylactic acid pellets obtainable by direct polymerization of lactic acid or ring-opening polymerization of lactide; and (b) removing low-molecular components having a weight-average molecular weight of 1,000 or less in the resulting crystallized, solid polylactic acid pellets by gasifying the low-molecular components to obtain polylactic acids with substantially no low-molecular components. In this method, an apparatus for removing low-molecular components in polylactic acid pellets includes a crystallizing means for maintaining a temperature between equal to or higher than a glass transition temperature of polylactic acid pellets and equal to or lower than the melting point thereof, while fluidizing the polylactic acid pellets; and a reactor for allowing a heated inert gas and/or heated air to pass through the resulting crystallized, solid polylactic acid pellets obtained by the crystallizing means.

Abstract: A method and system for producing poly(lactic acid) enable trapping and recovering of lactide vapor discharged from a reaction vessel without requiring a solvent or the like. In the method and system, lactide vapor is discharged from a polymerization reaction vessel in which poly(lactic acid) is produced by ring-opening polymerization, and trapped by solidification. The solidified lactide is liquefied by heat. Lactide can be recovered more easily and assuredly.

Abstract: The method for producing lactide includes the steps of (a) synthesizing lactide using lactic acid as a starting material; (b) discharging in gaseous states lactide synthesized and impurities formed upon synthesis in step (a); (c) liquefying gaseous components in step (b) and solidifying only lactide, to thereby separate the impurities from the thus-obtained solidified lactide; and (d) returning the separated impurities in step (c) back to the synthesis step (a). The apparatus used for the above production includes (a) a reactor for carrying out synthesis of lactide; (b) a means for gasifying synthesized lactide and impurities formed upon synthesis in the reactor (a) and discharging the resulting gaseous components; (c) a means for cooling the gaseous components to liquefy the gaseous components obtained by the means (b) and solidify only lactide; and (d) a pipe for returning to the reactor (a) components which are not solidified by the means (c).

Abstract: A method for producing an L-lactic acid with an optical purity of not lower than 70% comprising the steps of:(a) cultivating a microorganism of the genus Bacillus, in particular, Bacillus cereus and Bacillus thuringiensis, capable of producing an L-lactic acid with an optical purity of not lower than 70% from an assimilable carbon source; and (b) collecting an L-lactic acid with an optical purity of not lower than 70% from the culture.

Abstract: A method for producing a polylactic acid, comprising the steps of carrying out a ring-opening polymerization of lactide to give polylactic acid, adding a compound capable of inactivating a catalyst for ring-opening polymerization of the lactide at the completion of the reaction, and removing unchanged lactide from the polylactic acid product by reducing pressure and/or allowing an inert gas to pass; and a method for forming fiber or film directly from the polylactic acid produced by the invention.

Abstract: A method for recovering lactide from a high-molecular weight polylactic acid, comprising the steps of: (a) heat-treating a high-molecular weight polylactic acid to a temperature equal to or higher than a melting point of the polylactic acid to be treated in the presence of a catalyst comprising one or more metals selected from elements of Group IA, Group IVA, Group IVB, and Group VA of the Periodic Table, or compounds thereof; and (b) reducing a pressure to equal to or less than a vapor pressure of lactide at said temperature, to thereby distill and recover the produced lactide.

Abstract: A method for producing a polylactic acid of the present invention includes the steps of (a) polymerizing a lactide used as a main starting material in a molten state to give a polylactic acid; and (b) further polymerizing the polylactic acid obtained in step (a) in a solid phase by heating at a temperature lower than a melting point of a final polymer product.