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, and a method for making the same, is provided. The film consists of 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.
Claims108
A multilayer film, comprising:
- first and third layers;
- and
- a second layer, disposed between said first and third layers, comprising a terephthalic acid polyester;
- wherein said second layer is oriented in at least one direction to a higher stretch ratio than that attainable, under the same stretching conditions, for a monolithic film of said terephthalic acid polyester, and wherein said film has at least 7 layers.
A multilayer film, comprising:
- first and third layers;
- and
- a second layer, disposed between said first and third layers, comprising a terephthalic acid polyester;
- wherein said film is oriented in at least one direction to a higher stretch ratio than that attainable, under the same stretching conditions, for a monolithic film of said terephthalic acid polyester, wherein at least one of said first and third layers comprises a naphthalene dicarboxylic acid polyester, and wherein said naphthalene dicarboxylic acid polyester has an intrinsic viscosity of less than 0.52 dl/g.
A multilayer film, comprising:
- first and third layers;
- and
- a second layer, disposed between said first and third layers, comprising a terephthalic acid polyester;
- wherein said film is oriented in at least one direction to a higher stretch ratio than that attainable, under the same stretching conditions, for a monolithic film of said terephthalic acid polyester, and wherein said film is stretched to a nominal biaxial stretch ratio of at least 6.0.
A multilayer film, comprising:
- first and third layers;
- and
- a second layer, disposed between said first and third layers, comprising a naphthalene dicarboxylic acid polyester;
- wherein said naphthalene dicarboxylic acid polyester has an intrinsic viscosity of less than 0.52 dl/g.
A multilayer film, comprising:
- first and third layers;
- and
- a second layer, disposed between said first and third layers, comprising a naphthalene dicarboxylic acid polyester;
- wherein said film is oriented to a nominal biaxial stretch ratio of at least 6.0.
A multilayer film, comprising:
- first and third layers;
- and
- a second layer, disposed between said first and third layers, comprising a naphthalene dicarboxylic acid polyester;
- wherein said second layer is oriented in at least one direction to a higher stretch ratio than that attainable, under the same stretching conditions, for a monolithic film of said naphthalene dicarboxylic acid polyester.
Dependencies are inferred from the claim text.