Sound absorbing laminates

摘要

A process for forming sound absorbing laminates and the resulting laminate which comprises at least one layer of nonwoven fibers bonded to a substrate by a thermoplastic adhesive. The laminate is formed by placing a layer of bonded nonwoven fibers into contact with a substrate and bonding the layer of nonwoven fibers to the substrate. The improvement comprises: utilizing at least one layer of nonwoven fibers coated with an aqueous emulsion of a vinyl acetate-ethylene (VAE) adhesive and then dried. The VAE adhesive is prepared by aqueous emulsion polymerization, contains crystalline ethylene segments and has: (a) a crystalline melting point (T_m) ranging from 35 to 110° C., preferably 50 to 100° C.; measured at a heat rate of 20° C./minute; and, (b) a tensile storage modulus of at least 1x10⁴ dynes/cm² at 115° C. measured at a test frequency of 6.28 rad/sec.