Endothermic blowing agents for surface migration of components in foamed products, compositions and applications

Abstract

Compositions for producing foamed products which include additives and blowing agents which cause the surface treatment additives to migrate to the surfaces of foamed products. The products produced from the compositions require less additives because the incorporated additives are concentrated at the surface thereof.

What is claimed is: 
     
       1. A composition for producing a foamed product which comprises: at least one polymer component;   an additive which comprises platelet fillers, flame retardants, polar resin systems, and dormant chemical blowing agents; and   a blowing agent which causes said additive to migrate through said polymer component during a foaming process, said blowing agent comprising a mixture of a polycarboxylic acid and an inorganic carbonate, wherein said polycarboxylic acid and said inorganic carbonate have been surface treated with a component selected from the group consisting of mono- and di-glycerides, stearic acid, silane coupling agents, fatty acids, fatty acid salts, hydrotitinates, zirconates, and mixtures thereof.Iadd., said inorganic carbonate comprising sodium aluminum hydroxy carbonate. .Iaddend.   
     
     
       2. A composition for producing a foamed product according to claim 1, wherein said polycarboxyiic acid is selected from the group consisting of those of the formula HOOC--R--COOH and alkali metal salts thereof, wherein R, is alkylene of 1 to 25 carbon atoms which may contain one or more hydroxy substituents and may also contain unsaturation. 
     
     
       3. A composition for producing a foamed product according to claim 2, wherein said polycarboxylic acid is selected from the group consisting of citric acid, fumaric acid, tartaric acid, sodium hydrogen citrate, monosodium citrate, and mixtures thereof. .[.4. A composition for producing a foamed product according to claim 1, wherein said inorganic 
     
     
        carbonate is an alkali metal or alkaline earth metal carbonate..].5. A composition for producing a foamed product according to claim 1, wherein said .[.inorganic carbonate is selected from the group consisting of sodium aluminum hydroxy carbonate, sodium bicarbonate and mixtures 
     
     
        thereof, and said.]. polycarboxylic acid is citric acid. 6. A composition for producing a foamed product according to claim 1, wherein said surface 
     
     
        treating component comprises glyceryl monostearate. 7. A composition for producing a foamed product according to claim 1, wherein said additive is a platelet filler selected from the group consisting of mica, talc, clay, 
     
     
        calcium aluminum hydroxide and mixtures thereof. 8. A composition for producing a foamed product according to claim 1, wherein said additive is a flame retardant selected from the group consisting of alumina trihydrate, magnesium hydroxide, magnesium carbonate, hydrotalcite, and 
     
     
        mixtures thereof. 9. A composition for producing a foamed product according to claim 1, wherein said additive is a polar resin system selected from the group consisting of acrylonitride, polyvinyl alcohol, 
     
     
        ethylene-vinyl acetate, Nylon and mixtures thereof. 10. A composition for forming and surface treating polymer compositions which comprises: an additive which comprises platelet fillers, flame retardants, polar resin systems; and   a blowing agent for foaming a polymer composition and for causing migration of said additive through the polymer composition, said blowing agent comprising a mixture of a polycarboxylic acid and an inorganic carbonate, wherein said polycarboxylic acid and said inorganic carbonate have been surface treated with a component selected from the group consisting of mono- and di-glycerides, stearic acid, silane coupling agents, fatty acids, fatty acid salts, hydrotitinates, zirconates, and mixtures thereof.Iadd., said inorganic carbonate comprising sodium aluminum hydroxy carbonate. .Iaddend.