Patent ID: 6828010
Filing Date: 2004-12-07
Classification: B32B,B41M,C08L,Y10S,Y10T

Abstract:
A laminated polyester film characterized in that a laminated layer comprising two types of polyester resins having different glass transition points from each other is formed on at least one side of a base polyester film,wherein said two types of polyester resins comprises a polyester resin (A) having a glass transition point of from 60Â° C. to 100Â° C. and a polyester resin (B) having a glass transition point of from 0Â° C. to 60Â° C. wherein said polyester resin (B) at least contains from 65% by mol to 95% by mol of isophthalic acid as an acid component or from 50% by mol to 95% by mol of diethylene glycol as a diol component; and wherein the dicarboxylic acid component having a sulfonic acid metal base in the entire dicarboxylic acid components of the polyester resins (A) and (B) satisfies the following relation: Sa>Sb&gE;5% by mol wherein Sa represents a quantity (% by mol) of the dicarboxylic acid component having a sulfonic acid metal base in the entire dicarboxylic acid components of the polyester resin (A); and Sb represents a quantity (% by mol) of the dicarboxylic acid component having a sulfonic acid metal base in the entire dicarboxylic acid components of the polyester resin (B).