摘要:
In a process of manufacturing polylactide, synthesis of high-quality polymers is achieved with a sufficient degree of vacuum secured. Provided is an apparatus for manufacturing polylactide which includes the steps of preparing lactide through oligomerization of lactic acid and depolymerization of the resulting oligomers, effecting ring-opening polymerization of the lactide, and removing unreacted lactide. The apparatus comprises an exhausting gas treatment device for reducing pressure in the step of removing unreacted lactide. The exhausting gas treatment device includes boilers (81-83) for generating water vapor; a pressure-reducing section having stages each including an ejector (71-73) driven with the water vapor, a condenser (61-63) connected downstream of the ejector, and a hot well tank (41-43) connected to the condenser; and a main condenser 60 and a main hot well tank 40 connected to the main condenser that are disposed on a pipe line through which a gas of the unreacted lactide is suctioned into the pressure-reducing section. The gas of the unreacted lactide is washed away in the main condenser using a liquid containing lactic acid as a main component that has been collected in the main hot well tank.
摘要:
The polymer degassing apparatus includes a barrel-shaped horizontal container 41 having a supply port 42 for supplying a reactant, a discharge port 43 for discharging a reactant, a stirring means 45 for stirring a reactant, and a degassing means for drawing a gas via a degassing port 44 of the horizontal container. The supply port is positioned below the molten liquid level of the reactant. A recovery container 37 that is connected to the degassing port for recovering a volatile substance in the gas and a vacuum pump 36 are provided. The stirring means includes a plurality of stirring rods 46 oriented along the same direction as the axis in the horizontal container and coupling members 47 for coupling the stirring rods along the same direction as the axis, provided that the coupling members are placed at a distance from the virtual rotation center of the stirring means.
摘要:
The object of the present invention is to provide a polymer alloy including polylactic acid which can be used in the same manner as conventional commodity plastics even in an environment of high temperature and high humidity. According to the present invention, there is provided a polymer alloy including polylactic acid comprising (A) a polylactic acid, (B) a polyalkylacrylic ester and/or a polyvinyl ester, (C) a polyolefin and (D) a block copolymer of a polyalkylacrylic ester and polyolefin and/or a block copolymer of a polyvinyl ester and a polyolefin.
摘要:
An equipment for producing polyhydroxycarboxylic acid, includes a ring-opening polymerization apparatus, a liquid phase devolatilizing apparatus, and a drying apparatus, wherein an indirect heat exchanger is connected to a vent gas discharge path of the liquid phase devolatilizing apparatus. The indirect heat exchanger captures a dispersed in-process substance containing hydroxycarboxylic acid cyclic dimers and transfers the substance to the ring-opening polymerization apparatus; a wet condenser and a hot well are connected to a vent gas discharge path of the indirect heat exchanger and that of the drying apparatus, respectively. The wet condenser captures a dispersed in process substance containing the cyclic dimers with the use of a refrigerant containing hydroxycarboxylic acid corresponding to the cyclic dimers and transfers the substance to the hot well; the hot well causes hydrolysis of the cyclic dimers for generation of hydroxycarboxylic acid; the generated hydroxycarboxylic acid is mixed with a refrigerant and the mixture is circulated to the wet condenser; and hydroxycarboxylic acid is highly concentrated via circulation between the wet condenser and the hot well and then discharged.
摘要:
A polymerization method comprises, prior to polymerization of a monomer of the cyclic dimer of alpha-hydroxycarboxylic acid, a first mixture of a polymerization catalyst by bypassing a part of the monomer of the cyclic dimer is prepared. Then, the first mixture is mixed with a dominant amount of the monomer introduced into a polymerization reactor. The monomer of the cyclic dimer in the polymerization reactor is conducted in the presence of a polymerization initiator.
摘要:
The object is to provide a method and apparatus for producing a polyhydroxy carboxylic acid according to which an annular diner can be efficiently obtained in the production of polyhydroxy carboxylic acid which is small in distribution breadth of molecular weight in depolymerization and opening ring polymerization steps. There are provided a depolymerization device 11 which depolymerizes hydroxy carboxylic acid or a polycondensate thereof into an annular dimer, a upper distillation column 13 which condenses the annular dimer vaporized in the depolymerization device 11, and lower distillation column 12 which refluxes the annular dimer and is provided between the depolymerization device 11 and the upper distillation column 13, said depolymerization device 11 having a polycondensate feed opening 54 and an annular dimer discharge opening 55 which are provided at a casing 50, a liquid film being formed inside the casing 50 and heated by a heating part.
摘要:
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.
摘要:
The object of the invention is to provide a polymerization processor from a raw material in a molten state, which can synthesize a polymer of high quality. Lactide sent from an apparatus for supplying lactide 1 is heated and molten in an apparatus for melting lactide 2, and a catalyst is added to the lactide in an apparatus for supplying a catalyst 3. The molten lactide is supplied through an apparatus for supplying lactide 4 to a horizontal reaction tank 5, and flows by a head difference with a polymerization reaction proceeding. A discharged reaction solution is supplied to the upper part of a vertical reaction tank 6, and flows through the vertical reaction tank 6 by gravity with the polymerization reaction proceeding. Thereafter, the reaction solution is transported to an apparatus for removing remaining lactide 7, where unreacted lactide is removed, and then the reaction solution is discharged.
摘要:
An apparatus for continuous stirring comprising a horizontal elongated cylindrical vessel and two rotating blade assemblies rotatable in the direction opposite to each other provided in parallel to each other in the vessel, where a liquid feed is moved from one end to another therethrough by rotation of the two rotating blade assemblies in the direction opposite to each other, while stirring and mixing the liquid feed, the two rotating blade assemblies each comprising rotor shafts (3a-3b or 3c-3d) supported at both ends of the rotating blade assemblies, support members (4) each fixed to the rotor shafts, connecting members (5) span between the support members (4) and in positions far from the substantial rotating shaft center and a plurality of plate-shaped stirring blades (6) arranged in parallel in the longitudinal direction of the substantial rotating shaft center and fixed to the connecting members (5).
摘要:
An object of the present invention is to provide a method for commercially manufacturing acrolein in a large flow rate by making supercritical water and an acid interact with glycerin, wherein by efficiently mixing high-concentration glycerin and supercritical water with each other, the method is made capable of making the synthesis stably proceed with a high yield while the occlusion and abrasion of the pipes and devices due to the generation of by-products are being suppressed. The method for synthesizing acrolein of the present invention is a method for synthesizing acrolein by making supercritical water and an acid interact with glycerin, the method using a reaction apparatus including: a cylindrical mixing flow path for mixing a fluid including glycerin and a fluid including supercritical water with each other; a first inlet flow path, disposed offset from the central axis of the mixing flow path, for making the fluid including glycerin flow into the mixing flow path; and a second inlet flow path, disposed offset from the central axis of the mixing flow path, for making the fluid including supercritical water flow into the mixing flow path, wherein the first inlet flow path and the second inlet flow path are each provided in a plurality of numbers in such a way that the first inlet flow paths and the second inlet flow paths are alternately arranged so as to encircle the central axis of the mixing flow path.