METHOD FOR PRODUCING STRETCHED FILM
    10.
    发明公开

    公开(公告)号:EP4434724A1

    公开(公告)日:2024-09-25

    申请号:EP22895457.4

    申请日:2022-11-04

    Abstract: A method for producing a stretched film containing a poly(3-hydroxybutyrate) resin includes the steps of: (i) melting a film raw material and extruding the molten film raw material onto a cast roll to mold a film; (ii) separating the film from the cast roll to obtain a film having a crystallinity of 20 to 45%; and (iii-a) stretching the film in an MD direction to obtain a film having a crystallinity of 30 to 55%. The method may further include either or both of the steps of: (iii-b) stretching the film in a TD direction to obtain a film having a crystallinity of 30 to 60%; and (iv) heating the film to a temperature higher than a temperature during the step (iii-a) or (iii-b) to obtain a film having a crystallinity of 60% or more.

Patent Agency Ranking