Method for producing a polylactic acid-based film or sheet

• Main Authors: Senda, Hiroki, Ishiguro, Shigeki
• Format: Patent
• Language: English
• Published: 09.04.2019
• Subjects: ADHESIVES; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; CHEMICAL PAINT OR INK REMOVERS; CHEMISTRY; COATING COMPOSITIONS, e.g. PAINTS, VARNISHES ORLACQUERS; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; CORRECTING FLUIDS; DYES; FILLING PASTES; GENERAL PROCESSES OF COMPOUNDING; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS; INKS; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; ORGANIC MACROMOLECULAR COMPOUNDS; PAINTS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; PERFORMING OPERATIONS; POLISHES; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; USE OF MATERIALS THEREFOR; WOODSTAINS; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; WORKING-UP

A method of producing a polylactic acid based film or sheet with improved heat resistance and comprised of a resin composition containing a polylactic acid according to a melt film forming method, wherein the resin composition comprises polylactic acid (A), an acidic functional group-denatured olefin based polymer (B) containing an acidic functional group, and having an acid number of 10-70 mg KOH/g and a weight average molecular weight of 10,000-80,000, and a tetrafluoroethylene based polymer (C), which method comprises performing melt film formation at a temperature of the resin composition between the crystallization temperature (Tc) in a decreasing temperature process of the resin composition +15° C. and the melting temperature (Tm) in a raising temperature process −5° C., or solidifying the resin composition melt-formed in a film state by cooling after a temperature controllable step at crystallization temperature (Tc) in the decreasing temperature process ±10° C.