公开(公告)号：US20210198532A1

公开(公告)日：2021-07-01

申请号：US17057996

申请日：2019-05-21

Applicant: NITTO DENKO CORPORATION

Inventor： Takuma OGAWA ,  Yoshio NAKAGAWA ,  Takeshi IGARASHI ,  Kaito YAMAMOTO

IPC: C09J7/38 ,  C09J133/06

Abstract: An objective is to provide a surface protective PSA sheet that has well-balanced bonding strength for various adherends differing in polarity and a capability to suppress peeling and lifting as well as an ability to inhibit touch-up paint peeling and an increase in bonding strength with time. The surface protective PSA sheet having a PSA layer and a resin substrate supporting the PSA layer, characterized by satisfying the following conditions (a1), (a1-1) and (c1) has well-balanced bonding strength for various adherends differing in polarity and is capable of suppressing peeling and lifting and inhibiting touch-up paint peeling and an increase in boding strength with time. (a1) The PSA layer is formed from a PSA composition comprising a (meth)acrylic copolymer and a tackifier, the tackifier accounting for 1.0-30 parts by mass of the PSA composition with the (meth)acrylic copolymer being 100 parts by mass. (a1-1) The (meth)acrylic copolymer comprises 0.1-2.8% by mass functional group-containing structural unit, the structural unit including at least one species of functional groups selected from the group consisting of a carboxyl group and a salt thereof as well as a sulfo group and a salt thereof. (c1) The surface protective PSA sheet has tensile moduli of elasticity of 180-330 MPa in both MD and TD.