公开(公告)号：US4968554A

公开(公告)日：1990-11-06

申请号：US259682

申请日：1988-10-19

申请人： Tsunehisa Shigetani ,  Masahiro Yamana ,  Takao Ayukawa ,  Masahiro Kamiya ,  Tetsu Uesaka

发明人： Tsunehisa Shigetani ,  Masahiro Yamana ,  Takao Ayukawa ,  Masahiro Kamiya ,  Tetsu Uesaka

IPC分类号： D21F11/00 ,  G03C1/79 ,  G03C1/81

CPC分类号： D21F11/00 ,  G03C1/79 ,  G03C1/81 ,  Y10T428/24975 ,  Y10T428/3188 ,  Y10T428/31895 ,  Y10T428/31902

摘要： A support sheet for photographic paper having an enhanced resistance to curling, especially twist-curling, comprises a substrate paper sheet composed of a half stratum portion thereof at the face side of a surface on which a photographic emulsion layer will be formed and the other half stratum portion thereof at the back side of the opposite surface, and two polyolefin resin coating layers on the two surfaces of the substrate paper sheet, the substrate paper sheet having a resiliency satisfying the relationships (I) and (II):1.5.ltoreq.E.sub.fl /E.sub.bt .ltoreq.2.25 (I)=and ##EQU1## wherein E.sub.fl =a modulus of elasticity of the face side half stratum portion in the longitudinal direction of the substrate, E.sub.bt =a modulus of elasticity of the back side half stratum portion in the transverse direction of the substrate, E.sub.ft =a modulus of elasticity of the face side half stratum portion in the transverse direction of the substrate, and E.sub.bl =a modulus of elasticity of the back side half stratum portion in the longitudinal direction of the substrate.