Slip coated polyester film

Abstract

A polyester film coated with a slip composition is provided. The film includes a polyester film support coated on at least one side with a latex coating. The coating includes stearamidopropyldimethyl-.beta.-hydroxy-ethylammonium nitrate present in a coating weight in the range of up to 0.003 pounds per thousand square feet of biaxially oriented polyester film. The coating further includes a cross-linkable methylmethacrylate-ethylacrylate-methacrylamide terpolymer having a glass transition temperature in the range of between about 40.degree. C. and 50.degree. C. The terpolymer is present in a concentration in the range of between about 0.75 percent and 1.25 percent by weight, based on the total weight of the latex coating. The weight ratio of the nitrate to the terpolymer ranges between about 2.75:1 to below 3:1. A process for forming the above film is also disclosed. In this process a latex coating of the composition described above is coated onto a uniaxially drawn polyester film support. The uniaxially drawn film is then heated to drive off the water and thereafter the uniaxially coated film is stretched in a direction normal to the uniaxial drawn film.

Dependencies are inferred from the claim text.