Double sided adhesive tape

Abstract

A double sided adhesive tape is provided with adhesive layers on two surfaces of foam substrate. The interlayer strength of the foam substrate is more than 12N / cm, and 25% compressive strength is 30-170kPa. The adhesive layer is composed of an acrylic acid series composition which comprises the following components: acrylic acid series copolymer which comprises (methyl)acrylate with 4-12 carbon atoms and vinyl monomer with carboxyl as monomer component, and polymerized abietate series adhesive resin. According to the double sided adhesive tape, even when the rigid members are bonded with eachother, excellent sealing performance, reprocessing adaptability and repeeling performance between the double sided adhesive tape and the member being bonded can be realized. Furthermore water impregnating can be effectively prevented.

Description

technical field [0001] The present invention relates to a double-sided adhesive tape with a foam substrate as the core. Background technique [0002] In portable electronic devices such as electronic notebooks, mobile phones, PHS, cameras, music players, and TVs, double-sided adhesive tapes are used for fixing various parts and modules, represented by the lamination of the protective panel of the information display part and the case. . In order to secure a competitive advantage in the market, various functions are pursued, one of which is the function of imparting water resistance. [0003] As an adhesive tape for fixing parts of electronic devices, surface adhesion to a specific adherend is disclosed, for example, having a maximum value of loss tangent (tan δ) in the temperature range of -40 to -15°C. The strength is 19N / cm 2 The above-described adhesive layer is provided on both surfaces of a support body in a double-faced adhesive sheet (refer to Patent Document 1). ...

AI Technical Summary

Problems solved by technology

However, if only a foam is used as a base material alone, it is difficult to suppress microscopic voids at the interface between the component and the adhesive layer, even if there are voids that can be immersed in water on a part of the interface, floating (floating) ), it is difficult to achieve water resistance because the water intrusion path will be expanded from there

In particular, in the application of portable electronic devices, it is difficult to provide sufficient adhesive tape in the case of narrow tape width and thin tape thickness due to the narrow frame and further thinning requirements accompanying the recent increase in screen size. waterproof

[0005] In addition, in portable electronic devices, etc., in order to improve the yield at the time of manufacture, double-sided adhesive tapes, parts, etc. that have not been successfully bonded to unfinished products are sometimes peeled off (reprocessed), and in order to process finished products The case and parts are separated, disassembled, and disassembled for repair, regeneration, and reuse. However, in the case of the conventional double-sided adhesive tape of the foam base material, the foam base material is prone to interlayer damage, and it is easy to remain on the Part surface, and difficult to remove, thus reducing the efficiency of the operation of reattaching new double-sided adhesive tape after removing the double-sided adhesive tape from the case, part, the yield rate of the case, part, product, and the recycling rate

[0006] However, conventional foam substrates pursue softness (compressive strength) when compressed in the thickness direction, but there is no concept of strength (interlaminar strength) when stretched in the thickness direction.

In addition, when the adhesive strength of the adhesive is reduced alone, the adhesion with the adherend is also reduced, so it is difficult to impart sufficient waterproofness.

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