Foamed resin having electrical conductivity

Abstract

A foamed resin which has excellent flexibility and electrical conductivity, can be easily processed into a desired shape, and can be used as an electrically conductive cushioning seal with which the fine clearance between densely disposed electronic parts can be filled. The foamed resin is characterized by having a volume resistivity of 1010 Ocm or lower and a repulsive load at 50% compression of5 N / cm2 or lower. The foamed resin preferably has a surface resistivity of 1010 O / or lower. The foamed resin preferably has an apparent density of 0.01-0.15 g / cm3. Furthermore, the foamed resin preferably has an expansion ratio of 9 or higher.

Description

technical field [0001] The present invention relates to a flexible and electrically conductive resin foam having a high expansion ratio. More specifically, the present invention relates to a conductive resin foam having both the functions of a conductive material and a buffer sealing material. Background technique [0002] Conventionally, in electronic devices such as mobile phones, conductive materials have been used for grounding and electromagnetic field shielding from the viewpoint of preventing erroneous operation of devices. In addition, conventionally, in electronic devices such as mobile phones, cushioning and sealing materials have been used to prevent collisions between electronic parts and prevent entry of dust. [0003] However, in recent years, along with miniaturization of electronic devices such as mobile phones, there is a tendency for the number of components mounted inside to decrease and for high-density mounting of electronic components. Therefore, ther...

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Problems solved by technology

[0005] However, for materials in which a conductive material is laminated on the surface of a foam, the flexibility of the foam is impaired by the conductive material, and it is difficult to obtain conductivity in the thickness direction (volume resistivity in the thickness direction)

[0006] In addition, when the conductive cloth is wound on the foam, the flexibility of the foam is impaired by the conductive cloth, and shape processing by punching becomes difficult, and in many cases it cannot be performed as desired. It is difficult to obtain a material that sufficiently functions as a conductive material and a cushioning sealing material due to shape processing that matches the shape of the inserted part.

[0007] In addition, conventionally proposed foams (Patent Document 5 and Patent Document 6) in which a conductive material is added lack flexibility due to a low expansion ratio and are difficult to thin because of a large cell diameter. Layer processing makes it difficult to fill tiny gaps between high-density electronic parts

In addition, the inability to fill the tiny gaps between high-density electronic components may increase the resistance value of, for example, static elimination (grounding) parts.

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