Basic stabilisation systems for emulsion polymerised rubber

Abstract

There are described compositions comprising a) an emulsion crude rubber, synthetic latex or natural rubber latex subject to oxidative, thermal, dynamic and/or light-induced degradation, b) a compound of the formula (I) wherein R 1 is C 8 -C 12 alkyl, R 2 is hydrogen, C 1 -C 12 alkyl, cyclohexyl, 1-methylcyclohexyl, benzyl, α-methylbenzyl, α,α-dimethylbenzyl or —CH 2 —S—R 1 , R 3 is C 1 -C 12 alkyl, benzyl, α-methylbenzyl, α,α-dimethylbenzyl or —CH 2 —S—R 1 , R 4 is hydrogen or methyl, and c) a styrenated diphenylamine of the formula (II).

1 . A composition comprising
 (a) an emulsion crude rubber, synthetic latex or natural rubber latex subject to oxidative, thermal, dynamic and/or light-induced degradation, and   (b) a compound of the formula I   
       
         
           
           
               
               
           
         
         wherein 
         R 1  is C 8 -C 12 alkyl, 
         R 2  is hydrogen, C 1 -C 12 alkyl, cyclohexyl, 1-methylcyclohexyl, benzyl, α-methylbenzyl, α,α-dimethylbenzyl or —CH 2 —S—R 1 , 
         R 3  is benzyl, α-methylbenzyl, α,α,-dimethylbenzyl or —CH 2 —S—R 1 , 
         R 4  is hydrogen or methyl, and 
         (c) a styrenated diphenylamine of formula II 
       
       
         
           
           
               
               
           
         
       
     
     
         2 . A composition according to  claim 1 , wherein R 1  is C 8 alkyl or C 12 alkyl. 
     
     
         3 . A composition according to  claim 1 , wherein
 R 1  is C 8 alkyl or C 12 alkyl,   R 2  is methyl,   R 3  is —CH 2 —S—R 1 , and R 1  is C 8 alkyl or C 12 alkyl, and   R 4  is hydrogen.   
     
     
         4 . A composition according to  claim 1 , comprising from 0.01 to 10% by weight of component (b) of formula I, based on the weight of the dry solids content of component (a). 
     
     
         5 . A composition according to  claim 1 , comprising from 0.01 to 10% by weight of component (c) of formula II, based on the weight of the dry solids content of component (a). 
     
     
         6 . A composition according to  claim 1 , wherein component (a) is a pale emulsion crude rubber, a pale synthetic latex or a pale natural rubber latex. 
     
     
         7 . A composition according to  claim 1 , wherein component (a) is a polydiene emulsion crude rubber, a halogen-containing polydiene emulsion crude rubber or a styrene-butadiene copolymer emulsion crude rubber. 
     
     
         8 . A composition according to  claim 1 , wherein component (a) is a carboxylated styrene-butadiene, a styrene-acrylic acid, a vinyl acetate-acrylate or a carboxylated butadiene-acrylonitrile. 
     
     
         9 . A composition according to  claim 1 , wherein component (a) is an emulsion crude rubber which has been coagulated with a halogen containing system. 
     
     
         10 . A composition according to  claim 1 , wherein component (a) is an emulsion styrene-butadiene rubber (ESBR) or nitrile butadiene rubber (NBR). 
     
     
         11 . A composition according to  claim 1 , comprising in addition to components (a), (b) and (c) additionally further additives. 
     
     
         12 . A composition according to  claim 11 , comprising as further additives pigments, dyes, fillers, flow auxiliaries, dispersants, plasticisers, charge control agents, adhesion promoters, further antioxidants and/or light stabilisers. 
     
     
         13 . A composition according to  claim 11 , comprising as further additives phenolic antioxidants, aminic antioxidants, organic phosphites or phosphonites, lactones and/or thiosynergistic compounds. 
     
     
         14 . A method of stabilising an emulsion crude rubber, synthetic latex or natural rubber latex subject to oxidative, thermal, dynamic and/or light-induced degradation, in which method at least a component (b) and a component (c) according to  claim 1  is mixed with that material or applied thereto. 
     
     
         15 . (canceled)