Abstract: A modified polyolefin resin comprising a copolymer having a structure that a propylene-based polyolefin segment (a) and a segment (b) containing a lactic acid as a constituent are bonded in a block state and/or a graft state through a vinyl monomer having a hydroxyl group, wherein a number average molecular weight of the propylene-based polyolefin segment (a) is from 1,000 to 100,000, a number average molecular weight of the segment (b) containing lactic acid as a constituent is from 1,000 to 200,000, and a weight composition of the propylene-based polyolefin segment (a) and the segment (b) containing lactic acid as a constituent is from 10/90 to 90/10. The modified polyolefin resin can be used in a resin composition containing an aliphatic polyester resin (A), a polyolefin resin (B) and the modified polyolefin resin (C). The composition can exhibit excellent heat resistance and impact resistance and can be used for molding various parts.

Abstract: A modified polyolefin resin comprising a copolymer having a structure that a propylene-based polyolefin segment (a) and a segment (b) containing a lactic acid as a constituent are bonded in a block state and/or a graft state through a vinyl monomer having a hydroxyl group, wherein a number average molecular weight of the propylene-based polyolefin segment (a) is from 1,000 to 100,000, a number average molecular weight of the segment (b) containing lactic acid as a constituent is from 1,000 to 200,000, and a weight composition of the propylene-based polyolefin segment (a) and the segment (b) containing lactic acid as a constituent is from 10/90 to 90/10. The modified polyolefin resin can be used in a resin composition containing an aliphatic polyester resin (A), a polyolefin resin (B) and the modified polyolefin resin (C). The composition can exhibit excellent heat resistance and impact resistance and can be used for molding various parts.

Abstract: A polymerization process is provided for the preparation of graft (co)polymers. An embodiment of the polymerization process of the present invention comprises copolymerizing macromonomers with (co)monomers utilizing a macroinitiator to form a graft (co)polymer. A further embodiment of a polymerization process of the present invention comprises (co)polymerizing macromonomers and monomers with a graft copolymer macroinitiator to form a block-graft (co)polymer. Another embodiment of the process of the present invention comprises (co)polymerizing macromonomers and monomers with a compatible macroinitiator. The chemical and structural properties of the product graft (co)polymer may be controlled by use of a compatible macroinitiator and the functional group on the macromonomer which effect the relative rates of incorporation of the macromonomer and the monomer. Graft (co)polymers may be prepared with homogeneous or heterogeneous distribution of grafts.

Abstract: A resin composition (AA) comprising an aliphatic polyester or aliphatic polyamide (component (A)), a plastic having a melting point or glass transition temperature (Tg) of ?10° C. or more (component (B)) and a radical generating agent (C), wherein the compounding ratio of the component (A), the component (B) and the radical generating agent (C), based on the total weight thereof, is: 1 to 98.995% by weight of the component (A), 98.995 to 1% by weight of the component (B), and 0.005 to 5% by weight of the radical generating agent (C), and an aliphatic unsaturated polybasic acid (a) is contained in the polymer constituent of the component (A) and/or the component (B). The resin composition is suitable as a starting material of biodegradable material which maintains transparency, is free of bleeding of a plasticizer, is endowed with flexibility and has other advantageous characteristics so that it can be used in various fields.

Abstract: A polymerization process is provided for the preparation of graft (co)polymers. An embodiment of the polymerization process of the present invention comprises copolymerizing macromonomers with (co)monomers utilizing a macroinitiator to form a graft (co)polymer. A further embodiment of a polymerization process of the present invention comprises (co)polymerizing macromonomers and monomers with a graft copolymer macroinitiator to form a block-graft (co)polymer. Another embodiment of the process of the present invention comprises (co)polymerizing macromonomers and monomers with a compatible macroinitiator. The chemical and structural properties of the product graft (co)polymer may be controlled by use of a compatible macroinitiator and the functional group on the macromonomer which effect the relative rates of incorporation of the macromonomer and the monomer. Graft (co)polymers may be prepared with homogeneous or heterogeneous distribution of grafts.

Abstract: A sustained releasing drug which includes an effective component and a copolymer having a weight-average molecular weight of 1,000 to 100,000 which comprises, as repeating structure units, both of a succinimide unit represented by the structural formula (1) and a hydroxycarboxylic acid unit represented by the structural formula (2) wherein R is a methyl group or a hydrogen atom, and a process for preparing a copolymer which comprises a polymerization step of heating a mixture of aspartic acid and a cyclic ester compound.

Abstract: There are herein disclosed a copolymer having a weight-average molecular weight of 1,000 to 100,000 which comprises, as repeating structure units, both of a succinimide unit represented by the structural formula (1) 1

Abstract: A copolymer having a weight-average molecular weight of 1,000 to 100,000 which comprises, as repeating structure units, both of a succinimide unit represented by the structural formula (1) and a hydroxycarboxylic acid unit represented by the structural formula (2) wherein R is a methyl group or a hydrogen atom, and a process for preparing a copolymer which comprises a polymerization step of heating a mixture of aspartic acid and a cyclic ester compound.

Abstract: There are here disclosed a resin composition comprising a block or a graft copolymer (A) having a polyamino acid as a hydrophilic segment (a-1), and a degradable polymer as a hydrophobic segment (a-2), and a resin (B); and a method of accelerating the hydrolysis of a resin and inhibiting the heat deterioration thereof by mixing this copolymer (A) with the resin (B).

Abstract: A medical composition is here disclosed which comprises a hydroxy acid-based oligomer (A) and a drug (B), wherein the hydroxy acid-based oligomer (A) is an oligomer in which the carboxylic acid-terminals are at least partially esterified, and the oligomer (A) has a function of becoming pH 5 to 8 when administered into an organism, and the oligomer (A) shows fluidity at 25° C. This composition sustainedly releases the drug (B) to deliver it into an organism by a syringe or the like, and scarcely gives rise to irritation, inflammation or the like.

Abstract: A degradable copolymer filament comprising an internal structure having the following separate phases: (a) a matrix phase comprised as a primary component of a polymer segment which exhibits a tensile Young's modulus of 2 GPa or less and a strength retention of 50% or more after two weeks in water at 37.degree. C., pH 7.3, and (b) a micro-dispersed phase comprised as a primary component of a polymer segment which exhibits a tensile strength of 200 MPa or more and a strength reduction greater than the matrix phase in water at 37.degree. C., pH 7.3. The weight ratio of each component in the matrix phase and dispersed phase is 50:50 to 95:5, respectively, and the dispersed phase a needle structure oriented by stretching in the fiber direction. A degradable monofilament having an excellent mechanical strength and flexibility, moderate hydrolyzability, high ligature stability and being suitable as a material of surgical absorbable suture can be obtained. A preparation process is also provided.

Abstract: A bioabsorbable, ternary block copolymer consisting essentially of (A) polylactic acid segment, (B) poly(.epsilon.-caprolactone) segment and (C) polyglycolic acid segment, preparation process of the block copolymer, and medical molded articles prepared from said block copolymer. The bioabsorbable block copolymer is excellent in mechanical strength and flexibility and has moderate hydrolyzability and is especially utilized for a surgical monofilament suture.

Abstract: Disclosed are polymers (polyaspartic acid Zwitterionic derivatives) containing, in the molecule, 1 mol % or more of at least one repeating unit selected from the group consisting of repeating units represented by the following formulas (1) and (2). ##STR1## These polymers are useful in the preparation of hair-treating compositions and cosmetic compositions having excellent hairdressing properties and good biocompatibility.

Abstract: Articles matters which can be degraded and disappear in the natural environment are a degradable adhesive film which can be used for surface protection or indication after printing on the film surface and has an adhesive layer on one side of a substrate film obtained from a lactic acid base polymer such as polylactic acid and a lactic acid/hydroxycarboxylic acid copolymer having a molecular weight of 30,000.about.500,000, and a degradable resin composition which is excellent in weatherability and comprises 100 parts by weight of a lactic acid base polymer and 0.001.about.5 parts by weight of one or more additives selected from ultraviolet absorbers and light stabilizers.

Abstract: Articles which can be degraded and disappear in the natural environment are a degradable adhesive film which can be used for surface protection or indication after printing on the film surface and has an adhesive layer on one side of a substrate film obtained from a lactic acid base polymer such as polylactic acid and a lactic acid/hydroxycarboxylic acid copolymer having a molecular weight of 30,000-500,000, and a degradable resin composition which is excellent in weatherability and comprises 100 parts by weight of a lactic acid base polymer and 0.001-5 parts by weight of one or more additives selected from ultraviolet absorbers and light stabilizers.

Abstract: A degradable polymer composition essentially consisting of a mixture of a thermoplastic polymer composition primarily comprising polylactic acid or lactic acid-hydroxycarboxylic acid copolymer and one or more substance selected from starch and modified starch, and is a degradable polymer which does not cause problems such as environmental pollution and can be used for films, filaments and packaging materials, food packaging materials in particular.

Abstract: A degradable non-woven fabric obtained from an web formed of lactic acid-based polymer filaments comprising of one or more lactic acid-based polymers selected from a poly (DL-lactic acid) having more than 80 mol % of L-lactic acid units, poly (DL-lactic acid) having more than 80 mol % of D-lactic acid units, L-lactic acid/hydroxycarboxylic acid copolymer having 70 mol % or more of L-lactic acid units, and D-lactic acid/hydroxycarboxylic acid copolymer having 70 mol % or more of D-lactic acid units, and a preparation process of the degradable non-woven fabric which has good dimensional stability and can be degraded and disappeared under natural environment when abandoned.

Abstract: A laminate comprising a thermoplastic polymer essentially consisting of polylactic acid, a copolymer of lactic acid and hydroxycarboxylic acid or a mixture of polylactic acid with a copolymer of lactic acid and hydroxycarboxylic acid, and a regenerated cellulose film, paper, leather, cloth, or fiber. The laminate undergoes degradability in the natural environment, is excellent in transparency, gloss and moisture-proofness, has high strength and can be used for various packaging materials.

Abstract: In the preparation of polyester by conducting ring-opening polymerization of a cyclic ester compound in the presence of a hydroxyl compound as a molecular weight regulator in the reaction system, the molecular weight of polyester can be accurately controlled in the desired range by previously estimating the amount of free carboxylic acid contained in the cyclic ester compound and controlling the amount of the hydroxyl compound on the basis of the estimated amount.

Abstract: The present invention provides a nylon composition having increased hydrolyzability which is obtained by physically mixing 100 parts by weight of a nylon with 1 to 50 parts by weight of at least one polymer selected from the group consisting of polylactic acid, polyglycolic acid and a copolymer containing 50 mol % or more of a lactic acid unit or a glycolic acid unit as a repeating unit in its chain; and a method for increasing the hydrolyzability of a nylon by preparing such a composition. High hydrolyzability can be imparted to the nylon inherently having extremely low hydrolyzability without impairing its original mechanical strength. Therefore, various molded articles made from the nylon can be hydrolyzed under natural circumstances, and thus the wastes are not stored.