Molded solid plastics articles and a method for their manufacture

Abstract

This invention relates to composite articles of manufacture and to a method for the preparation of these articles. The articles are impact-resistant, three-dimensional and rigid. The articles are comprised of two essential elements: (1) A pliable, hollow premolded outer plastics layer and (2) an essentially rigid non-cellular organic plastics structural backing member solidified in the hollow interior of the plastics skin, and essentially solidly filling said hollow interior. The hollow outer layer is prepared in a manner to have an access opening to its hollow interior. A liquid plastics composition is next prepared in a separate step that comprises an organic binder which solidifies at room temperature, in most cases by converting to a thermoset stage. This liquid composition is then introduced through the access opening into the cavity of the premolded outer layer. The liquid composition is then solidified in a manner to fill essentially voidlessly and fully the cavity of the outer layer, thus producing a dense tough integral article of manufacture having the shape of the premolded outer layer. Illustrative for the outer layer materials are plasticized polyvinylchloride compositions, polyethylene and rubbers. Illustrative for the interior component are epoxy resins, polyester resins, room temperature curing phenolics, filler containing polysulfide rubber, repolymerized depolymerized rubber and polyurethanes. Fillers may be present in the liquid compositions. By the favored method the outer plastics layer is kept in its original mold when applying and solidifying the liquid plastics composition in its hollow interior. Such mold is either a multipiece or an elastomeric mold permitting removal of the completed rigid article even if undercuts in the shape of the article are present.