the same as those shown in example 1 were prepared according to the procedure in example 1 except that the peroxide was used in unsupported form rather than supported on clay ______________________________________ parts by weightingredients formulation e formulation f______________________________________epdm rubber vistalon 100 1002504 enjay co zinc oxide 5 5age rite resin d 1 5 1 5r t vanderbilt co antioxidant fef carbon black 40 40trimethyolpropane 1 5 1 5trimethacrylate curingcoagent u03b1 u03b1 39 bis t butylperoxy diiso 1 52 1 52propylbenzene meta paraisomer ratio about 2 0 1 phthalic anhydride 1 33______________________________________ the formulations were cured as described in example 2 and stored at room temperature bloom was observed as indicated below ______________________________________ formulation e formulation f______________________________________after 2 days slight noneafter 30 days very much none______________________________________ the following formulations were prepared by blending on a two roll mill at 60 u00b0 65 u00b0 c for 10 minutes ______________________________________ parts by weightingredients formulation g formulation h______________________________________epdm rubber minnesota 60 60rubber co 557n m b fef carbon black 40 40zinc oxide 5 5 u03b1 u03b1 bis t butylperoxy diiso 5 75 propylbenzene on clay support 40 by weight peroxide meta para isomer ratioabout 2 0 1 peroxide 40 nb 5 75 4 parts u03b1 u03b1 39 bis t butylperoxy diisopropylbenzene 2 5 parts burgess ke clay 3 5 parts phthalic anhydride ______________________________________ both formulations were cured into sheets 0 075 inch thick by heating.