Polyethylene sealant film having high strength and package using the same

Patent metadata

Field	Value
Publication number	US-10611132-B2
Application number	US-201615382608-A
Country	US
Kind code	B2
Filing date	Dec 17, 2016
Priority date	Dec 17, 2015
Publication date	Apr 7, 2020
Grant date	Apr 7, 2020

Abstract

In order to provide a polyethylene sealant film having great strength and good heat sealability, despite being thin, a multilayer polyethylene sealant film is produced by a method including coextruding and stretching a sealant layer formed of a low density polyethylene resin or linear low density polyethylene resin and an orientation layer including a polyethylene resin having a melting point higher than the sealant layer, by an inflation method at a temperature higher than the melting point of the sealant layer and higher than the Vicat softening temperature, but lower than the melting point of the orientation layer.

First claim

We claim:

1. A coextruded inflation multilayer polyethylene sealant film consisting essentially of:
a sealant layer made of a low density polyethylene resin or a linear low density polyethylene resin having a melting point of 90-110° C. and a Vicat softening temperature of 70-105° C. and being without orientation; and
an orientation layer made of a polyethylene resin having a melting point of 120 -130° C. and a Vicat softening temperature of 80-120° C. and an MFR of 0.1 - 0.5 g/10minutes and is oriented, wherein the polyethylene resin of the orientation layer has a molecular weight distribution Mw/Mn of 6 or more;
wherein a melting point and a Vicat softening temperature of the sealant layer are lower than those of the orientation layer, respectively;
wherein the whole body of the film has an orientation degree of 0.05-0.5.

2. A coextruded inflation multilayer polyethylene sealant film as set forth in claim 1 , wherein the polyethylene resin of the orientation layer is a low density polyethylene resin or a linear low density polyethylene resin.

3. A coextruded inflation multilayer polyethylene sealant film as set forth in claim 1 , wherein:
the orientation layer comprises an outer layer and an intermediate layer; and
a melting point and a Vicat softening temperature of the intermediate layer are lower than a melting point and a Vicat softening temperature of the outer layer, respectively.

4. A package comprising:
a coextruded inflation multilayer polyethylene sealant film as set forth in claim 1 ; and
a substrate film laminated to said sealant film.

5. A package as set forth in claim 4 , wherein said coextruded inflation multilayer polyethylene sealant film comprises at least two sealant layers, and further comprising:
a heat seal between said at least two sealant layers, said heat seal having a strength of 12-20 N/15 mm in width.

Assignees

• Hosokawa Yoko Kk

Inventors

• Kobayashi Yukio
• Kageyama Yohei
• Miyazaki Munenori
• Kojima Yoshihiro
• Tanaka Yoshikazu

Classifications

• B32B2307/516

  mono-axially · CPC title

• B32B2307/30

  having particular thermal properties · CPC title

• B32B27/26

  using curing agents · CPC title

• B32B2307/31

  Heat sealable · CPC title

• B32B2553/00

  Packaging equipment or accessories not otherwise provided for · CPC title