US 11,753,513 B2
Polyolefin resin foam and production method thereof and adhesive tape
Taiyo Honda, Otsu (JP); Yusuke Kojima, Tokyo (JP); and Tadafumi Akiyama, Otsu (JP)
Assigned to TORAY INDUSTRIES, INC., Tokyo (JP)
Appl. No. 16/648,589
Filed by TORAY INDUSTRIES, INC., Tokyo (JP)
PCT Filed Oct. 3, 2018, PCT No. PCT/JP2018/037006
§ 371(c)(1), (2) Date Mar. 18, 2020,
PCT Pub. No. WO2019/073873, PCT Pub. Date Apr. 18, 2019.
Claims priority of application No. 2017-197413 (JP), filed on Oct. 11, 2017.
Prior Publication US 2020/0239657 A1, Jul. 30, 2020
Int. Cl. C08J 9/00 (2006.01); C08J 5/18 (2006.01); C08J 9/228 (2006.01); C09J 123/06 (2006.01); C09J 123/12 (2006.01); C09J 201/00 (2006.01)
CPC C08J 9/0061 (2013.01) [C08J 5/18 (2013.01); C08J 9/228 (2013.01); C09J 123/06 (2013.01); C09J 123/12 (2013.01); C09J 201/00 (2013.01); C08J 2323/06 (2013.01); C08J 2323/12 (2013.01); C09J 2203/00 (2013.01)] 6 Claims
 
1. A polyolefin resin foam sheet having front and back surfaces which is made of a polyolefin resin foam comprising a polyolefin resin and a thermoplastic elastomer resin, wherein
the polyolefin resin foam sheet endothermic peaks measured by a differential scanning calorimeter (DSC) occur in a range of at least 120° C. or more and 143° C. or less and at 153° C. or more and 170° C. or less,
said thermoplastic elastomer resin is contained at a ratio of 40% by mass or more and 60% by mass or less based on 100% by mass of the resins constituting the polyolefin resin foam sheet,
said polyolefin resin is contained at a ratio of 60% by mass or less and 40% by mass or more based on 100% by mass of the resins constituting the polyolefin resin foam sheet,
together the thermoplastic elastomer resin and the polyolefin resin constitute 100% by mass of the resins constituting the polyolefin resin foam sheet,
a surface roughness Sa (arithmetic mean height) of both the front and the back surfaces is 16 μm or more and 80 μm or less, and a difference in surface roughness Sa between the front and the back surfaces is 20 μm or more and less than 50 μm based on the following formula:
(Difference in surface roughness Sa between the front and the back surfaces)=(Surface roughness Sa on the surface B)−(Surface roughness Sa on the surface A),
both the surface A and the surface B are sliced and stretched,
an average cell size in a machine direction (MD) corresponding to a resin extrusion direction or length direction on both the front and the back surfaces is 134 μm or more and 550 μm or less, and
a ratio of the average cell size in the MD direction on the surface B to the average cell size in the MD direction on the surface A is 1.2 or more and 1.35 or less based on the following formula:
(Ratio of the average cell size in the MD direction)=(Average cell size in the MD direction on the surface B)/(Average cell size in the MD direction on the surface A).