Sealing material and method of foaming application thereof

Abstract

Objective problems of the present invention are: to provide a sealing material which does not involve flowing after applied, and shows an excellent sealing performance even under severe heat resistance conditions, and also can make good independent cells inside even when used in a foamed condition; and to provide a method of foaming application of the sealing material. As means of solving these objective problems, the sealing material according to the present invention is characterized by comprising an ultraviolet-curable component and an ultraviolet polymerization initiator and having a thermoplastic elastomer (which is not ultraviolet-curable) content of not higher than 5 weight % and comprising an acrylate as the ultraviolet-curable component and having a melt-viscosity at 120° C. in a certain range wherein the acrylate has a glass transition temperature after ultraviolet curing and a weight-average molecular weight in their respective certain ranges; and the method according to the present invention of foaming application of a sealing material is characterized by comprising the steps of: hot-melting the sealing material; mixing nitrogen gas into the melted sealing material under a predefined pressurization; discharging the resultant mixture at a predefined pressure into the air to thus foam the mixture and simultaneously apply it to a place necessary to seal, thus making a sealing foam; and curing this sealing foam by ultraviolet rays.

Dependencies are inferred from the claim text.