Stretched film and method for producing same
AssigneeC.I. Takiron Corporation
InventorsKazufusa SASAHARA, Keiichi MORI, Hiroyuki OSHIMA
Life of this patent
Estimating the term…
Abstract
The stretched film includes a base layer and a barrier layer. The base layer contains, as a main component, polyethylene having a density of 0.950 g/cm3 or more. The barrier layer contains, as a main component, an ethylene-vinyl alcohol copolymer. The stretched film has a water vapor transmission rate of 3.5 g/m2·day or less, and a thermal shrinkage in a stretching direction of the stretched film of 5% or less when heated at 100° C. for 10 minutes.
Claims4
A stretched film comprising at least a first base layer and a barrier layer,
- the first base layer containing, as a main component, polyethylene having a density of 0.950 g/cm3 or more,
- the barrier layer containing, as a main component, an ethylene-vinyl alcohol copolymer,
- the stretched film having a water vapor transmission rate of 3.5 g/m2·day or less and
- a thermal shrinkage in a stretching direction of the stretched film of 5% or less when the stretched film is heated at 100° C. for 10 minutes.
A method for producing a stretched film, the method at least comprising:
- preparing a raw film at least including a base layer containing, as a main component, polyethylene having a density of 0.950 g/cm3 or more and a barrier layer containing, as a main component, an ethylene-vinyl alcohol copolymer;
- and
- stretching the raw film, wherein
- in the stretching, a stretching temperature is equal to or higher than 80° C. and lower than 130° C., and a stretch ratio is from 5 times to 10 times inclusive.
Dependencies are inferred from the claim text.