Kureha Corporation

Masaru Kagoshima

Mitsuhiro Matsuzaki

Hiroaki Ohashi

Yoshiki Shigaki

Shigeru Suzuki

Kazuyuki Yamane

Tomoyuki Ogawa

Michio Kikuchi

An apparatus for continuous high temperature gas treatment of particulate matter including a starting material supply port () through which starting particulate matter is supplied from an upper part of the apparatus; a treatment, gas supply port () through which a treating gas is supplied; a product discharge port () through which a product after treatment is discharged from a lower part of the apparatus; a treatment chamber () in which the particulate matter is treated with the treatment gas; a gas-solid separation chamber () provided in fluid communication with an upper part of the treatment chamber (); and a cooling chamber () provided in fluid communication with a lower part of the treatment chamber (). A heater () is provided on the outer periphery of the upper part of the treatment chamber (), and a cooler () is provided on the outer periphery of the cooling chamber ().

Apparatus and method for continuous high temperature gas treatment of particulate matter

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&#xb0; 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.

Method for producing glycolide

An apparatus for continuous high temperature gas treatment of particulate matter including a starting material supply port () through which starting particulate matter is supplied from an upper part of the apparatus; a treatment gas supply port () through which a treating gas is supplied; a product discharge port () through which a product after treatment is discharged from a lower part of the apparatus; a treatment chamber () in which the particulate matter is treated with the treatment gas; a gas-solid separation chamber () provided in fluid communication with an upper part of the treatment chamber (); and a cooling chamber () provided in fluid communication with a lower part of the treatment chamber (). A heater () is provided on the outer periphery of the upper part of the treatment chamber (), and a cooler () is provided on the outer periphery of the cooling chamber ().

Glycolide production through depolymerization of glycolic acid oligomer is stabilized by controlling impurities in the glycolic acid oligomer to allow economical and effective production of glycolide. More specifically, the depolymerization system is controlled to suppress an effective concentration (x+100y wt. %) of depolymerization-obstructing substances calculated as a total of a concentration calculated as diglycolic acid (of x wt. %) of hydroxyl group-free impurity carboxylic acids (A) and 100 times a concentration calculated as ammonia (of y wt. %) of nitrogen-containing substances (B), respectively with respect to the starting glycolic acid oligomer in the depolymerization system, to at most 15 wt. %.

Process for producing glycolide and glycolic acid oligomer for production of glycolide

There is provided a method for producing a poly(arylene sulfide) in which a dihalo-aromatic compound and an alkali metal halide are polymerized by heating in an organic amide solvent, wherein the cooling time for the polymerization reaction system is significantly reduced. After the polymerization process, there is provided a cooling process for cooling the polymerization reaction system comprising a liquid phase containing the product poly (arylene sulfide) and the organic amide solvent and a vapor phase containing a gas component (A); and in the cooling process, the gas component (A) in the vapor phase is cooled while the content of a low boiling gas component (A), which has a lower boiling point than water and exists in the gas component (A), is reduced in the vapor phase of the polymerization system.

Process for production of polyarylene sulfide

A process for producing polyarylene sulfide includes: steps of reacting an aromatic dihalide compound and an alkaline metal compound in a polar organic solvent for polymerization under heating and cooling a system including the reaction mixture to recover particulate polyarylene sulfide (PAS). The system after the reaction is gradually cooled at an average cooling speed of 0.2 to 1.0 deg. C./min. selectively in a temperature range of from 1 deg. C. below to 1 deg. C. above a maximum system-viscosity temperature. As a result, the process can be operated at a relatively short polymerization cycle and yet provides the product PAS particles with a high and stable bulk density as to exhibit good processability in the transportation and storage, and excellent transportability in a hopper or a screw of an extruder or a molding machine.

Growing community of inventors

Iwaki, Japan

Masaru Kagoshima