US 12,091,524 B2
Method for producing biodegradable resin expanded sheet
Shota Endo, Osaka (JP); Eiji Fukuyama, Osaka (JP); and Ayano Mori, Osaka (JP)
Assigned to SEKISUI KASEI CO., LTD., Osaka (JP)
Appl. No. 17/433,370
Filed by SEKISUI KASEI CO., LTD., Osaka (JP)
PCT Filed Mar. 25, 2020, PCT No. PCT/IB2020/052783
§ 371(c)(1), (2) Date Aug. 24, 2021,
PCT Pub. No. WO2020/194199, PCT Pub. Date Oct. 1, 2020.
Claims priority of application No. 2019-064204 (JP), filed on Mar. 28, 2019.
Prior Publication US 2022/0169817 A1, Jun. 2, 2022
Int. Cl. C08J 9/14 (2006.01); B29C 44/20 (2006.01); B29C 48/00 (2019.01); B29C 48/09 (2019.01); B29C 48/32 (2019.01); B29C 48/87 (2019.01); B29C 48/885 (2019.01); B29C 48/89 (2019.01); B29C 44/50 (2006.01); B29C 48/10 (2019.01); B29C 48/28 (2019.01); B29C 48/88 (2019.01); B29K 67/00 (2006.01); C08K 3/34 (2006.01); C08L 101/16 (2006.01)
CPC C08J 9/141 (2013.01) [B29C 44/20 (2013.01); B29C 48/0022 (2019.02); B29C 48/09 (2019.02); B29C 48/32 (2019.02); B29C 48/87 (2019.02); B29C 48/885 (2019.02); B29C 48/89 (2019.02); B29C 44/507 (2016.11); B29C 48/022 (2019.02); B29C 48/10 (2019.02); B29C 48/28 (2019.02); B29C 48/88 (2019.02); B29K 2067/00 (2013.01); B29K 2067/04 (2013.01); B29K 2995/006 (2013.01); C08J 2201/03 (2013.01); C08J 2367/02 (2013.01); C08K 3/346 (2013.01); C08L 101/16 (2013.01)] 3 Claims
OG exemplary drawing
 
1. A method for producing a biodegradable resin expanded sheet, the method comprising:
melting and kneading a resin composition containing a biodegradable resin and a blowing agent with an extruder, and extrusion expanding the melted and kneaded resin composition in a molten state from a circular die having an annular discharge port to form a cylindrical expanded sheet;
sliding-contacting an external peripheral surface of a cooling mandrel having a diameter larger than that of said annular discharge port on an internal surface of said cylindrical expanded sheet to cool said cylindrical expanded sheet from an internal side while enlarging a diameter thereof; and
cutting the cylindrical expanded sheet that has been subjected to diameter enlargement along an extrusion direction to develop the cylindrical expanded sheet, to obtain a flat belt-like expanded sheet,
wherein said cylindrical expanded sheet is cooled so that a temperature of an external surface of said cylindrical expanded sheet at a position at which 5 seconds have elapsed after being discharged from said annular discharge port, and before being in sliding contact with the external peripheral surface of the cooling mandrel, becomes 50° C. or higher and 70° C. or lower.