| 摘要 |
<p>An acoustic damping material is disclosed comprising a fibrous mat or polymeric cellular material coated with a dried composition selected from elastomeric and plasticised plastomeric latices or emulsions of styrenebutadiene rubbers, neoprene, polyvinyl chloride, or ethylene-vinylacetate copolymers or mixtures of two or more thereof, the composition containing a filler having a specific gravity of at least 2.5 and a particle size of from 1 to 200 microns, the amount of filler being effective to provide from 60 to 85% total solids by weight of wet composition prior to drying, together with an amount of an anionic or non-ionic surfactant effective to stabilise the rubber, neoprene, polyvinyl chloride, or ethylene-vinylacetate copolymer. The method of preparing it and a composition suitable for application to the desired fibrous mat or polymeric cellular material substrate are also enclosed. The use of neoprene latices and of fillers having a specific gravity of 3 or more, for example barytes, is desirable and the preferred substrate is compressed or uncompressed glass fibre. The composition is retained as a coating on the substrate by mechanical adhesion, thereby obviating disadvantages inherent in other forms of adhesion and the material is of particular application in the automobile industry.</p> |
