Process for producing ethylene-vinylalcohol copolymer resin and its granular material and the same resin granular material

Application Number  00128695 Application Date  2000.07.23
Publication Number  1287051 Publication Date  2001.03.14
Priority Information   1999/7/23 JP 240274/99; 1999/12/15 JP 355947/99; 1999/12/15 JP 355948/99; 1999/12/15 JP 355949/99; 1999/12/15 JP 355950/99; 1999/12/15 JP 355951/99  
Applicant(s) Name  Kuraray Co., Ltd.  
Inventor(s) Name  Kahara Takaharu;Kaai Hiroshi;Tsuboi Toshio  
Patent Agency Code  72001 Patent Agent  wei jinxi
AbstractA process for producing an ethylene-vinyl alcohol copolymer resin, including feeding EVOH into an extruder, keeping the temperature of the melting resin in the extruder at 70 to 170 DEG C, adjusting the amount of water in the extruder so that the water content right after being discharged from the extruder is 5 to 40 weight %, and extruding out the EVOH resin. The extruded EVOH resin is cut into EVOH pellets. Thereby, it is possible to obtain resin pellets in which no spherocrystals are observed in the center of the cross section of the resin when the cross section is observed by the use of a polarization microscope, or no lubricant is contained in the resin pellets, and the angle of repose is 23 DEG or less when the resin pellets are laminated. Thus, it is possible to provide an ethylene-vinyl alcohol copolymer (EVOH) resin pellet having a reduced discharging load to the environment and capable of being fed into an extruder smoothly without being blocked, extruding stability, and thermal stability (long-run property).