SEPARATOR

摘要

The present invention provides a separator including a separator substrate composed of a polylactic acid film or sheet having tear strength so as not to break or tear during, for example, production or processing of the separator or winding thereof into a roll, and causing neither melt nor deformation at high temperatures more than 100°C. The separator according to the present invention is a separator including a separator substrate and a removable pressure-sensitive adhesive layer on at least one surface of the separator substrate, wherein the separator substrate is composed of a polylactic acid film or sheet comprising polylactic acid (A) wherein the tear strength of the film or sheet is not less than 100 N/mm when the film or sheet is torn at least in a flow direction (MD), a rate of dimensional change due to heating is not more than ±3% in the flow direction (MD) and a transverse direction (TD), and a rate of dimensional change due to loaded heating is not more than ±3% in the flow direction (MD).