PET-C Based Security Laminates and Documents

A method of preparing a security laminate including the steps of:

• a) stretching a polyester substrate in either a longitudinal or a transversal direction;
• b) coating and drying a subbing layer on the stretched polyester substrate;
• c) stretching the coated polyester substrate in the longitudinal or transversal direction not selected in step a) in order to obtain a coated biaxially stretched polyester substrate having a subbing layer;
• and
• d) coating and drying an adhesive layer on top of the dry subbing layer, wherein the adhesive layer contains a mixture of a first and a second polymer in a weight ratio from 50/50 to 90/10,
• wherein the first polymer is a copolymer comprising vinyl acetate and at least 85 wt % of vinyl chloride based on the total weight of the first polymer;
• wherein the second polymer is a copolymer of styrene, butadiene and methylmethacrylate, a copolymer of vinyl butyral, vinyl acetate and vinyl alcohol and/or particulate polymethylsilsesquioxane.