Abstract: The present invention provides an absorbable barrier membrane for guided tissue regeneration which is useful for regeneration of animal tissues, including those of humans, the absorbable barrier membrane being superior in heat stability, processability, reproducibility, storage stability, bioabsorbablity, and tissue regeneration effects, and further provides a method for regeneration, using the absorbable barrier membrane, of a mandible, periodontal tissue, or defective tubulous bone, and particularly a defective tubulous bone which possesses a segmental bone defect in which both ends of the bone are in separate segments. The above objects are attained by an absorbable barrier membrane for use in guided tissue generation, comprising a lactic copolyester in which a polymerization catalyst is deactivated, as an essential component.

Abstract: The present invention provides a biodegradable expanded material having excellent expandability, moldability, impact resistance, heat resistance and storage stability. The present invention also provides a process for the preparation of the foregoing expanded material. The present invention further provides a laminate of a non-expanded material layer and an expanded material layer prepared from the foregoing expanded material which exhibits excellent impact resistance and heat resistance and an excellent transparency in the non-expanded material even after heat treatment so that a pattern printed on the inner side of the non-expanded material layer can be clearly viewed from the outside.

Abstract: The present invention provides a biodegradable expanded material having excellent expandability, moldability, impact resistance, heat resistance and storage stability. The present invention also provides a process for the preparation of the foregoing expanded material. The present invention further provides a laminate of a non-expanded material layer and an expanded material layer prepared from the foregoing expanded material which exhibits excellent impact resistance and heat resistance and an excellent transparency in the non-expanded material even after heat treatment so that a pattern printed on the inner side of the non-expanded material layer can be clearly viewed from the outside.

Abstract: The present invention provides a biodegradable material having excellent organic compatibility, moldability, mechanical properties, biodegradability and storage stability which can be used as bone substitute material, material for osteosynthesis, bone filling material, dental material, material having controlled release of chemical, material having controlled release of physiologically active compound or the like and a process for the preparation thereof. A novel biodegradable material is provided, comprising as essential components a lactic acid-based polymer (A) consisting of structural units (a) derived from lactic acid components and polyester structural units (b) derived from dicarboxylic acid components and diol components, the weight ratio of (a)/(b) being from 98/2 to 20/80, and a calcium phosphate-based compound (B), wherein the weight ratio of (A)/(B) is from 99/1 to 30/70. A process for the preparation of such a biodegradable material is also provided.

Abstract: The present invention provides a process for the preparation of a lactic acid-based polyester having an excellent moldability, storage stability and biodegradability which has a less residual lactide left therein and is less susceptible to decomposition of lactic acid-based polyester and attachment of sublimed lactide to the molding apparatus, etc. at the devolatilization step and molding step after the polymerization reaction of lactic acid-based polyester. In the present invention, an organic chelating agent is added to a lactic acid-based polyester to deactivate the esterification catalyst used in the preparation of the lactic acid-based polyester, making it possible to inhibit the decomposition of lactic acid-based polyester at the devolatilizing process and molding process after polymerization reaction.

Abstract: The present invention provides a process for the preparation of a biodegradable lactic acid-based polyester composition excellent in thermal stability, storage stability, flexibility, heat resistance, mechanical and physical properties and moldability which comprises kneading a lactic acid-based polyester and a polyester consisting of dicarboxylic acid component(s) and diol component(s) with a chelating agent, an acidic phosphoric acid ester, a molecular weight increasing agent, etc., and then devolatizing the kneaded mixture. The present invention also provides a molding process of the foregoing lactic acid-based polyester composition.

Abstract: The present invention provides a process for the continuous production of a biodegradable polyester polymer with an excellent quality useful in the field of medicine, coating material and packaging material by eliminating difficulty in uniform agitation and heat removal caused by the rise in the viscosity of reactants in the production of a high molecular biodegradable polyester polymer by ring-opening polymerization.

Abstract: A process for producing a lactic acid-based copolyester by the ring-opening copolymerization and transesterification of a lactide (A) with an aromatic polyester (B) and/or an aliphatic polyester (C) in the presence of a ring-opening polymerization catalyst (D), and a packaging material comprising the lactic acid-based copolyester obtained by the process are disclosed. According to the present invention, a lactic acid-based degradable copolyester which has a sufficiently high molecular weight and satisfactory toughness and also has suitable rigidity, pliability, and transparency according to applications can be produced. Further, a general-purpose packaging material, e.g., a sheet or film, which comprises the lactic acid-based copolyester produced by the process and is excellent in formability, degradability, and transparency can also be produced.