A kind of polyolefin resin foam sheet and its manufacturing method

Abstract

The invention relates to a polyolefin-based resin foamed sheet with a thickness of 0.04mm-2mm. The foamed sheet comprises at least one skin layer, and the average thickness of a single skin layer accounts for 0.5%-30% of the total thickness. The crust layer is defined as a certain thickness that extends continuously inward from the vertical outer surface of the foamed sheet, and there are no bubbles in this thickness or the volume of bubbles with a pore diameter of 10 μm or less accounts for 98% or more of the total volume of bubbles in the layer. The foamed sheet is conducive to positive water blocking, while taking into account high cushioning performance, to achieve the desired effect of low residual rate of azo foaming agent, positive water blocking and cushioning performance.

Description

technical field [0001] The invention relates to a polyolefin resin foam sheet, which is especially suitable for a waterproof sealing tape for electronic equipment. Background technique [0002] Polyolefin resin foam sheet can still have high shock absorption performance under thin conditions, so it is widely used in electronic equipment such as smart phones, personal computers, electronic paper, etc., and is arranged in electronic components and frame structure parts. Between them, it plays the role of buffer sealing. [0003] In the prior art, an azo-based foaming agent, such as azodicarbonamide (AC foaming agent), is used to foam the polyolefin-based resin substrate, but after foaming, the foaming agent remains. On the one hand, the residual azo-based blowing agent has a negative impact on the mechanical properties of the polyolefin resin foam sheet, and on the other hand, it may cause serious harm to the environment. and Restriction Regulations) explicitly limit its res...

AI Technical Summary

Problems solved by technology

[0004] However, for polyolefin-based foamed sheets, too high a foaming temperature will lead to too high open porosity, which will eventually lead to poor positive water blocking effect of the material, and reducing the amount of foaming agent used will also lead to Cell density and compressive strength effects become poorer, ultimately resulting in poorer cushioning properties of the foamed material

[0005] It can be seen that for foaming materials, the residual rate of azo foaming agent, porosity, and positive water blocking effect affect each other, and it is difficult for the current foaming materials in the prior art to reduce the azo residue to Under the condition of less than 0.1wt%, it can still have a relatively good positive water blocking effect

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