PURPOSE: A releasable coating agent excellent in the releasability, strength, water resistance, abrasion resistance, etc., of a film, comprising a copolymer emulsion obtained by emulsion-polymerizing a monomer mixture essentially consisting of vinylidene chloride and a (meth)acrylate ester.

CONSTITUTION: 70W92wt% vinylidene chloride (A) is mixed with 30W8wt% (meth)acrylate ester (B) (e.g., methyl acrylate) and, optionally, a monomer copolymerizable with components A and B (e.g., acrylonitrile or acrylic acid). This monomer mixture is emulsion-polymerized to produce a polymer emulsion. This polymer emulsion as the principal component is mixed with, optionally, a releasability improver (e.g., silicone or paraffin), plasticizer, pigment, etc., to obtain the purpose releasable coating agent. This coating agent is used by applying it to a substrate by spraying, brushing or the like.