Patent GB-1092169-A (GB)
Title: Textured foam product and process for the production thereof
IPC: C08J9/10
Filed: 1966-02-15
Abstract: A textured cellular foam product comprises a layer of cellular foam resinous composition having depressed areas in its surface, the resinous composition beneath said depressed areas containing blowing agent and a metal chelating complex having a chelate formation constant of at least 104, wherein said metal is a catalyst for the decomposition of said blowing agent.  Suitable resins are vinyl chloride polymer compositions, e.g. a vinyl chloride/vinyl acetate copolymer.  A suitable blowing agent is 1,11-azobisformamide.  A long list of chelating agents and metal catalysts is given.  The product is made by incorporating the blowing agent and metallic catalyst (which lowers the decomposition temperature of the blowing agent) in a resinous composition and subsequently heating the composition to foam it, the process being characterized by applying to portions of the surface prior to said heating a chelating agent for said metal having the required chelate formation constant, and heating at a temperature to selectively decompose only part of the blowing agent. The chelating agent may be printed on to the said areas in the form of an ink.  Specified inks are based on PVC-vinyl acetate copolymers (see Examples 1 and 2) and contain one of the following chelating compounds: 2-mercaptobenzthiazole, N,N1-disalicylidene - 1,2 - propanediamine, alizarin, 1,8-dihydroxyanthraquinone or acetoacetanilide. Specified catalysts are Zn stearate or Pb phosphite. Other ingredients specified are dioctyl phthalate, hydrocarbons, methyl ethyl ketone, dibasic lead phosphite, zinc stearate, tricresyl phosphate, titanium dioxide and pigments.ALSO:A textured cellular foam product, which may be coated onto a backing and/or be subsequently coated with a resinous layer, comprises a layer of cellular foam resinous composition having depressed areas in its surface, the resinous composition beneath said depressed areas containing a blowing agent and a metal chelating complex having a chelate formation constant of at least 104, wherein said metal is a catalyst for the decomposition of the blowing agent.  The product is made by incorporating the blowing agent and a metallic catalyst which lowers the decomposition temperature of the blowing agent in a resinous composition and subsequently coating areas of the surface with a chelating agent for the metal having the required chelate formation constant, and then heating to foam the composition at a temperature to decompose selectively only part of the blowing agent. In Example 1, a vinyl acetate/vinyl chloride copolymer containing filler, dibasic lead phosphite, plasticiser and blowing agent is coated onto a cellulose felt sheet impregnated with a resin, and this is heated to gel it, and subsequently an ink based on vinyl chloride/vinyl acetate copolymer and containing 2-mercaptobenzthiazole as chelating agent is coated on it. Finally an organosol based on PVC (dispersion grade) is applied over the printed surface, and the whole sheet heated to foam it. The final product is stated to be of use as a floor covering.