Polyolefin resin foam and production method thereof and adhesive tape
AssigneeToray Industries, Inc.
InventorsTaiyo Honda, Yusuke Kojima, Tadafumi Akiyama
Life of this patent
Estimating the term…
Abstract
One object of the present invention is to provide a polyolefin resin foam sheet suitable as a sealing substrate having both flexibility and heat resistance despite its thinness, and an adhesive tape in which the polyolefin resin foam sheet is used. In order to achieve this, the polyolefin resin foam includes a thermoplastic elastomer, wherein the endothermic peaks measured by a differential scanning calorimeter (DSC) occur in the range of at least 110° C. or more and 143° C. or less and at 153° C. or more, and the thermoplastic elastomer resin is contained at a ratio of 30% by mass or more and 60% by mass or less in 100% by mass of the polyolefin resin.
Claims6
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).
Dependencies are inferred from the claim text.