Decorative surface coverings

In a process for producing a resinous laminated assembly on a base, said assembly containing a plurality of raised cellular areas on the surface thereof and a plurallity of fibrous areas adjacent to said raised areas, useful as a covering, said process comprising the steps of:

• 1. incorporating azodicarbonamide into a plasticized vinyl chloride polymer composition;
• 2. forming the resulting vinyl chloride polymer composition into a layer;
• 3. the improvement comprising
• applying to portions of said formed layer an inhibitor-containing elastomer solution adhesive comprising fully reacted polyurethane solution, trimellitic anhydride and solvent therefor, said trimellitic anhydride being capable of penetrating into said vinyl chloride polymer composition and altering the decomposition temperature of said azodicarbonamide;
• 4. and imbedding nylon fibrous particles into said inhibitor-containing adhesive composition by means of a mechanical beater bar technique, and thereafter
• 5. heating the resulting assembly to effect the azodicarbonamide-trimellitic anhydride inhibition reaction and thereafter, to decompose the azodicarbonamide so as to cause expansion at the sites of decomposition and the formation of contrasting thickness on the surface thereof, said nylon fibrous particles being imbedded end-on in the non-expanded areas of said resinous assembly.