Multilayer polyester film
Assignee3M Innovative Properties Company
InventorsBrandt K. Carter, Raymond L. Lucking, James A. Klein, Sheldon J. Israel
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Abstract
A multilayer polyester film having at least 7 layers which comprises alternating layers of polyethylene terephthalate and polyethylene naphthalate. Biaxial orientation and subsequent restrained heat setting of these materials results in thin films with tensile moduli in both stretch directions well in excess of the values obtained with monolithic films of either material. In some embodiments, a slippery surface is imparted to the film without the use of conventional slip agents.
Claims32
A multilayer film having at least 7 layers arranged in a sequence which alternates between a layer consisting essentially of a naphthalene dicarboxylic acid polyester and a layer consisting essentially of a terephthalic acid polyester, said film containing from about 70% to about 95% by weight of said naphthalene dicarboxylic acid polyester, and from about 5% to about 30% by weight of said terephthalic acid polyester.
A multilayer film having at least 7 layers and comprising a sequence of layers which alternates between a first layer type comprising a naphthalene dicarboxylic acid polyester and a second layer type comprising a terephthalic acid polyester;
- wherein said sequence comprises from about 70% to about 90% by weight of said first layer type and from about 10% to about 30% by weight of said second layer type.
Dependencies are inferred from the claim text.