Adhesive sheet for electronic devices

Abstract

The purpose of the present invention is to provide an adhesive sheet for electronic devices, which has a high impact-resistant adhesion property, is rarely displaced even when a load is applied to the adhesive sheet in the shear direction, and also has excellent repulsion resistance. The present invention is an adhesive sheet for electronic devices, which has an adhesive agent layer comprising 100 parts by weight of an acrylic copolymer and 20 to 35 parts by weight of an adhesiveness-imparting resin having a softening point of 110 DEG C or lower and an alcoholic hydroxy group value of 30 or more, wherein the acrylic copolymer is produced by copolymerizing a monomer mixture comprising (a) 24.7 to 58.98% by weight of 2-ethylhexyl acrylate, (b) 30 to 50% by weight of butyl acrylate, (c) 10 to 20% by weight of methyl acrylate, (d) 1 to 5% by weight of acrylic acid and (e) 0.02 to 0.3% by weight of a (meth)acrylate having a hydroxy group and has a weight average molecular weight (Mw) of 800,000 or more, and the adhesive agent layer is crosslinked with a crosslinking agent to such an extent that the gel fraction becomes 20 to 50%.

Description

technical field [0001] The present invention relates to a pressure-sensitive adhesive sheet for electronic devices that has high impact-resistant adhesiveness, is less prone to shifting even when a load is applied in a shear direction, and is excellent in rebound resistance. Background technique [0002] PSA sheets are used for assembly in electronic equipment (for example, mobile phones, mobile information terminals, etc.) equipped with image display devices or input devices. Specifically, for example, an adhesive sheet is used for bonding a cover panel for protecting the surface of an electronic device to a touch panel module or a display panel module, or for bonding a touch panel module to a display panel module. Such a pressure-sensitive adhesive sheet requires various performances including adhesiveness, for example, impact-resistant adhesiveness that does not peel off from an adherend even if it receives an impact from the outside is considered essential. [0003] As ...

AI Technical Summary

Problems solved by technology

[0004] However, in recent years, with the enlargement of the screen and the diversification of the design of electronic equipment, as the adhesive sheet used in the assembly, the adhesive sheet that can be processed more finely is also required. PSA sheets with foam as the base material tend to shift when a load is applied in the shear direction during processing

In addition, there is also the problem of poor rebound resistance

[0005] Examples of substrates with excellent resilience resistance include polyethylene terephthalate (PET) films, but when substrates with low cushioning properties such as PET films are used, it is difficult to express the High impact resistance adhesion in the case of foam

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