Crosslinked solid type pressure-sensitive adhesive composition, pressure-sensitive adhesive sheet comprising the composition, and pressure-sensitive adhesive sheet for waterproofing/airproofing comprising the sheet

Abstract

A solid type pressure-sensitive adhesive composition capable of being applied without the necessity of using an organic solvent or water and a pressure-sensitive adhesive sheet, which are excellent in both adhesive force and holding power and, in particular, undergo no decrease in low-temperature adhesive force even when the adhesive layer thickness is small. The crosslinked solid type pressure-sensitive adhesive composition comprising (a) a rubbery polymer, (b) a tackifier, and (c) a crosslinking agent comprising at least one member selected from the group consisting of thiuram vulcanizing agents, quinoid vulcanizing agents, quinone dioxime vulcanizing agents, and maleimide vulcanizing agents.

Description

[0001] The present invention relates to a crosslinked solid type pressure-sensitive adhesive composition which does not substantially contain a solvent, and a pressure-sensitive adhesive sheet (including a tape, film and other form) obtained by applying the composition with heating to a substrate. The invention further relates to a pressure-sensitive adhesive sheet for waterproofing / airproofing comprising the pressure-sensitive adhesive sheet.DESCRIPTION OF THE RELATED ART[0002] Due to the enforcement of the Housing Quality Security Promotion Law, it is desired to completely eliminate the leaking of rain in houses, and various waterproof sheets are used. Recently, various airproof sheets also have been used with the demand for highly airtight, highly heat-insulated houses, which are highly effective in energy saving. Conventional pressure-sensitive adhesive sheets for use as such waterproof or airproof pressure-sensitive adhesive sheets employ a pressure-sensitive adhesive comprisin...

AI Technical Summary

Problems solved by technology

Pressure-sensitive adhesive sheets in which the adhesive does not show cohesive failure upon peeling are undesirable because a space is formed between the adherend and the pressure-sensitive adhesive to pose the possibility that water might penetrate into the space to impair waterproofing.

On the other hand, the rubber-asphalt pressure-sensitive adhesive has a durability as short as about 10 years and shows poor adhesiveness at high temperatures and low temperatures.

The acrylic pressure-sensitive adhesive, which has been marketed recently, is less apt to show cohesive failure upon peeling from adherends and whether or not this pressure-sensitive adhesive retains a sufficient waterproofing function over many years has not been demonstrated.

Such solid type pressure-sensitive adhesive compositions are uncrosslinked compositions which have poor cohesive force especially at high temperatures and hence have often caused positional shifting.

In this case, the practical kneading temperature during the kneading is about 180.degree. C. at the most, and it is considerably difficult to heat the composition to, for example, 200.degree. C., which is necessary for the crosslinking reaction with sulfur generally used for the crosslinking of butyl rubbers.