POLYLACTIC ACID FOAM MOLDING MATERIAL, FOAM-MOLDED ARTICLE THEREOF AND METHOD FOR PRODUCING SAME

• Main Authors: UCHIYAMA, Kosuke, CHOU, Yen-Ju
• Format: Patent
• Language: English; French; German
• Published: 11.07.2018
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; GENERAL PROCESSES OF COMPOUNDING; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; WORKING-UP

The present invention economically provides a method and device for producing a high-viscosity polylactic acid foam molding material which is suitable for foam molding at a high expansion ratio, and a foam molded article having a high expansion ratio which is formed of said polylactic acid composition. A polylactic acid foam molding material having an MI value of 0.05-5, measured in accordance with JIS K7210 at 190°C under a 21.6-kg load, is produced by physically or mechanically lowering the molecular weight and rebonding, in the presence of a supercritical inert gas, polylactic acid having a molecular weight in terms of polystyrene of 2,000,000 or higher by GPC measurement generated when three types of crosslinked polylactic acid (A), (B), and (C) having different component ratios of D and L isomers, obtained by reacting polylactic acid composed of D and L isomers with a crosslinking agent, are mixed in a weight ratio of 25-50:25-50:25-50 (where (A) + (B) + (C) = 100) and the mixture is melted; and a foam molded article is produced by providing a grinding orifice on an injection molding machine or an extrusion molding machine, discharging from a die at a temperature from the softening point to 110°C, and foam molding.