EP2403703B2

Multilayer, heat-shrinkable film comprising a plurality of microlayers and method for its fabrication

Abstract

This record has no abstract on file.

EP2403703B2, drawing sheet 1
Sheet 1 of 12

Term

3.4 yearsleft in the term

Expires 2 March 2030.

  1. Priority and filed
  2. Granted
  3. Today
  4. Expires

14 claims: 2 independent, 12 dependent

  1. 1
    A multilayer, heat-shrinkable film, comprising:a. a bulk layer;and b. a microlayer section comprising a plurality of microlayers;wherein said microlayer section comprises at least 10 microlayers;wherein, each of said microlayers and said bulk layer have a thickness, the ratio of the thickness of any of said microlayers to the thickness of said bulk layer ranging from about 1:2 to about 1:40;and wherein, said heat-shrinkable film has a thickness of less than 17.8 µm (0.7 mil) and an Elmendorf Tear value (ASTM D1922-06a) of at least 10 grams, as measured in at least one direction along a length or width dimension of said film.
  2. 9
    A method of making a multilayer, heat-shrinkable film, comprising:a. extruding a bulk layer;b. coextruding at least 10 microlayers to form a microlayer section;c. merging said bulk layer and said microlayer section to form a multilayer film;and d. stretch-orienting said multilayer film under conditions that impart heat-shrinkability to said film;wherein, each of said microlayers and said bulk layer have a thickness, the ratio of the thickness of any of said microlayers to the thickness of said bulk layer ranging from about 1:2 to about 1:40;wherein, said film has a total free shrink (ASTM D2732-03) of at least about 10% at 93.3 °C (200 °F);wherein, at least one of the microlayers comprises a blend of two or more polymers and has a composition that is different from at least one other microlayer;and wherein said heat-shrinkable film has an Elmendorf Tear value (ASTM D1922-06a) of at least 1.18 g/µm (30 grams/mil), as measured in at least one direction along a length or width dimension of said film.