Shimadzu Corporation

Masaaki Oota

Masahiro Ito

Hitomi Ohara

Seiji Sawa

Yasuhiro Fujii

Kenji Takeda

Hiroki Kuyama

Hiroyoshi Minakuchi

Junya Kobayashi

Katsuhiko Kada

Saburo Kato

Hideshi Yamaguchi

Akara Hashimoto

Hiroyuki Oshima

A CO,fixation system for fixing Co,gas existing in the atmosphere or in an exhaust gas emitted from factories and other burning sites. The system includes a fermenting tank for anaerobically fermenting organic wastes, whereby methane gas is produced. The methane gas is decomposed and hydrogen gas is produced. The hydrogen gas is reacted with the CO,gas to produce carbon powder and water, whereby the CO,gas is fixed to become harmless to the global warming.

Carbon dioxide fixation system

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.

Method for producing polylactic acid and apparatus used therefor

The polymerization reaction is conducted by heating a lactide, a cyclic imide compound (e.g. succinimide, etc.) and a polymerization catalyst (e.g. tin octylate, etc.) at 100-190.degree. C. with stirring under a nitrogen gas flow. It is preferred that an amount of the cyclic imide compound is from 1 to 35% by mole based on the lactide. Even if an amount of the polymerization catalyst is small, e.g. 0.00001-0.1 mole %, based on the lactide, polylactic acid can be efficiently prepared. It is possible to avoid remains of the catalyst in the polymer and coloring of the polymer.

Process for preparing polylactic acid

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.

Method for producing polylactic acid

The polylactic acid-based resin composition includes (a) (i) 100 parts by weight of a poly-L-lactic acid; or (ii) 100 parts by weight of a poly-DL-lactic acid comprising L-lactic acid and D-lactic acid as its constituting units; and (b) 5 to 120 parts by weight of at least one of low-molecular lactic acid derivatives. The molded product is produced by the steps of 1) melt-kneading (a) one of the above components (i) or (ii) and the component (b); and 2) subjecting the melt-kneaded product obtained in step 1) to an injection molding, to give a desired molded product.

Polylactic acid-based resin composition and use therefor

An oxynitride glass, a process for preparing same and a fiber thereof, in the glass which has Si--M.sub.1 --M.sub.2 --O--N system and contains SiO.sub.2, Si.sub.3 N.sub.4 and M.sub.1 O in amounts which, as mole %, satisfy the following equations (a) and (b):

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Mukou, Japan

Masaaki Oota