Paint film-protecting sheet

摘要

A paint film-protecting sheet (1) that effectively prevents adhesive transfer to the paint film is provided. The paint film-protecting sheet (1) includes a pressure-sensitive adhesive (PSA) layer (20), which is comprised of a non-crosslinking PSA, disposed on a polyolefin-based resin film serving as a supporting substrate (10). At least a surface portion (12) of the supporting substrate which adjoins the PSA layer is formed of a resin material that satisfies both of the following conditions: (1) it contains W wt % of a LLDPE having a density d of 0.925 g/cm3 or less, wherein W is greater than or equal to 20; and (2) it has a LLDPE content index α of 400 or more, the LLDPE content index α being defined as (0.935−d)×W×1000.

主权项

1. A paint film-protecting sheet comprising a supporting substrate and a pressure-sensitive adhesive layer on the supporting substrate, wherein:
the pressure-sensitive adhesive layer is comprised of a non-crosslinking pressure-sensitive adhesive, the supporting substrate is comprised of a resin film which contains at least one polyolefin selected from polyethylene and polypropylene in an amount of at least 50 wt % of the entire supporting substrate, at least a surface portion of the supporting substrate which adjoins the pressure-sensitive adhesive layer is comprised of a resin material that satisfies both of the following conditions: (1) it contains W wt % of a linear low-density polyethylene (LLDPE) having a density d of 0.925 g/cm3 or less, wherein W is greater than or equal to 20; and (2) it has a LLDPE content index α of 400 g/cm3 or more, the LLDPE content index α being defined as (0.935−d)×W×1000; and wherein the resin material of the surface portion comprises 30-60 wt % homopolypropylene and 10-40 wt % propylene copolymer, the supporting substrate comprises 5 to 15 parts by weight of titanium oxide per 100 parts by weight of resin components in the resin film, and the supporting substrate has a tensile modulus of elasticity in a machine direction at 23° C. of 850 MPa or less.