Extruded polyethylene-based resin foam sheet and interleaf sheet for glass plates

Patent metadata

Field	Value
Publication number	US-9631060-B2
Application number	US-201314420832-A
Country	US
Kind code	B2
Filing date	Aug 1, 2013
Priority date	Aug 23, 2012
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

An extruded foam sheet having a foam layer constituted of a base resin containing low density polyethylene as a major component thereof, wherein the foam sheet has an apparent density of 45 to 450 kg/m 3 , an average thickness of 0.03 mm or more and less than 0.3 mm and a dimensional change of −5% to 0% in the extrusion direction when heated at 80° C. for 24 hours and wherein cell walls of the foam layer have an average thickness of 6 to 70 μm. The foam sheet may be used as an interleaf sheet for glass plates.

First claim

The invention claimed is:

1. An extruded polyethylene-based resin foam sheet having a foam layer constituted of a base resin containing low density polyethylene as a major component thereof,
wherein cell walls of said foam layer have an average thickness of 6 to 70 μm, and
wherein the extruded polyethylene-based resin foam sheet has an apparent density of 120 to 450 kg/m 3 , an average thickness between 0.03 mm and 0.15 mm, and a dimensional change of −5% to 0% in the extrusion direction when heated at 80° C. for 24 hours and has a 25% compression stress of 10 kPa or more in the thickness direction of the extruded polyethylene-based resin foam sheet.

2. The foam sheet according to claim 1 , wherein said base resin additionally contains linear low density polyethylene in an amount of 5 to 20% by weight based on the total weight of the low density polyethylene and linear low density polyethylene.

3. The foam sheet according to claim 1 , further comprising a resin layer laminated on at least one side of said foam layer.

4. An interleaf sheet for glass plates that is formed of the foam sheet according to claim 1 .

5. The foam sheet according to claim 2 , further comprising a resin layer laminated on at least one side of said foam layer.

6. An interleaf sheet for glass plates that is formed of the foam sheet according to claim 2 .

7. An interleaf sheet for glass plates that is formed of the foam sheet according to claim 3 .

8. The extruded polyethylene-based resin foam sheet according to claim 1 , wherein an average number of cells in a thickness direction of the foam layer is 4 to 15/mm.

9. The extruded polyethylene-based resin foam sheet according to claim 6 , wherein the foam layer has a cell flattening in at least one of an extrusion direction and transverse direction of 0.1 to 0.6.

10. The extruded polyethylene-based resin foam sheet according to claim 1 , wherein the extruded polyethylene-based resin foam sheet has an apparent density of 150 to 450 kg/m 3 .

Assignees

• Jsp Corp

Inventors

• Nishimoto Takashi
• Aoki Takeshi

Classifications

• C08J9/0061 Primary

  characterized by the use of several polymeric components · CPC title

• C08J2201/03

  Extrusion of the foamable blend · CPC title

• Y10T428/249991

  Synthetic resin or natural rubbers · CPC title

• B32B2307/56

  Damping, energy absorption · CPC title

• C08J9/08

  developing carbon dioxide · CPC title