Polyolefin resin foam sheet and adhesive tape

Patent metadata

Field	Value
Publication number	US-11046871-B2
Application number	US-201615779171-A
Country	US
Kind code	B2
Filing date	Nov 29, 2016
Priority date	Nov 30, 2015
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

There is provided a polyolefin resin foam sheet formed by foaming a polyolefin resin, wherein the expansion ratio of the foam sheet is 1.5 to 20 cm3/g, the average cell sizes in the MD direction and the TD direction of the foam sheet are 130 μm or less, and the following formulas (1) and (2) are satisfied:TM/D≥6  (1); andTT/D≥5  (2), whereTM denotes the tensile strength at 90° C. in the MD direction,TT denotes the tensile strength at 90° C. in the TD direction, andD denotes the density (g/cm3) of the foam sheet.

First claim

The invention claimed is:

1. A polyolefin resin foam sheet formed by foaming a polyolefin resin, the foam sheet having the expansion ratio of 1.5 to 8 cm 3 /g, the foam sheet having the average cell sizes of 130 μm or less in the MD direction and the TD direction respectively, and satisfying the following formulas (1) and (2):
T M /D≥ 6  (1); and

T T /D≥ 5  (2), where

T M denotes the tensile strength in MPa at 90° C. in the MD direction,
T T denotes the tensile strength in MPa at 90° C. in the TD direction, and
D denotes the density in g/cm 3 of the foam sheet,
wherein the shear strength at 90° C. is 0.3 to 10 MPa.

2. The polyolefin resin foam sheet according to claim 1 , wherein the 25% compressive strength is 10 to 1,000 kPa.

3. The polyolefin resin foam sheet according to claim 1 , wherein the tensile strength at 23° C. in the MD direction is 0.5 to 35 MPa.

4. The polyolefin resin foam sheet according to claim 1 , wherein the tensile strength at 23° C. in the TD direction is 0.5 to 30 MPa.

5. The polyolefin resin foam sheet according to claim 1 , wherein the thickness is 0.02 to 0.8 mm.

6. The polyolefin resin foam sheet according to claim 1 , wherein the gel fraction is 5 to 60% by mass.

7. An adhesive tape having a pressure sensitive adhesive layer provided on at least one surface of the polyolefin resin foam sheet according to claim 1 .

Assignees

• Sekisui Chemical Co Ltd

Inventors

• Nagai Kento
• Matsuki Shigeki

Classifications

• C09J2423/006

  in the substrate · CPC title

• C09J2400/243

  in the substrate · CPC title

• C09J2301/312

  parameters being the characterizing feature · CPC title

• C09J2301/302

  the adhesive being pressure-sensitive, i.e. tacky at temperatures inferior to 30°C · CPC title

• C09J2203/318

  for the production of liquid crystal displays · CPC title