Foamed hot melt adhesives - decreases use of adhesive but gives good bond esp. used for book binding, packaging and coating

摘要

The use of foamed hot melt adhesives (I) to bond materials is new. (I)contains a blowing agent, (II) which is inactive when mixed with (I) but forms a foam when (I) is used. (II) is pref. e.g. azodicarbonamide, or dinitroso-pentamethylene tetramine, etc. pref. with an average particle size of 10-30 micron. The compsn. pref. also contains a crosslinker. (II) and the crosslinker are chosen so that foaming and crosslinking takes place simultaneously. (I) is EVA and/or thermoplastic elastomer opt contg.a resin such as a coumarone-indene or (cyclo)aliphatic hydrocarbon resin or (co)polyamide or polyester. Despite using less (I), high adhesion can be achieved. (I) can be used for wood, metal, fibres, paper, cardboard etc. e.g. carpet laying bands, book binding, packaging.