Liquid stabilizing mixtures for organic polymers

Abstract

Liquid stabilizing mixtures for organic polymers comprising: a) a liquid compound belonging to the group of sterically hindered phenols consisting of esters or mixtures of esters having formula (I); b) a solid compound belonging to the group of sterically hindered phenols having formula (II).

1 . Liquid stabilizing mixtures for organic polymers comprising: 
 (a) a liquid compound belonging to the group of sterically hindered phenols consisting of esters or mixtures of esters having general formula (I):                          wherein:    R 1  and R 2 , the same or different, represent a linear or branched C 1 -C 18  alkyl group;    R 3  represents a linear or branched C8-C 18  alkyl group, or one of the following groups:                          CH 3 —(CH 2 )p—CH 2 —;   wherein m and n are an integer ranging from 0 to 11, extremes included; and m+n is 10 or 11; and p is 12 or 13;    (b) a solid compound belonging to the group of sterically hindered phenols having formula                          wherein n is an integer ranging from 0 to 10, extremes included.    
     
     
         2 . The liquid stabilizing mixtures according to  claim 1 , wherein, in general formula (I), the linear or branched C 1 -C 18  alkyl groups are: methyl, ethyl, propyl, isopropyl, butyl, 2-butyl, isobutyl, t-butyl, pentyl, 2-pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, t-octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl.  
     
     
         3 . The stabilizing mixtures according to  claim 1  or  2 , wherein the liquid compounds belonging to the group of sterically hindered phenols (a) are those wherein R 1  and R 2 , the same or different, are: methyl, ethyl, isopropyl, t-butyl; and R 3  represents one of the following groups:  
       
         
           
           
               
               
           
         
       
       wherein m, n and p have the same meanings defined above.  
     
     
         4 . A process for the preparation of the above liquid stabilizing mixtures which comprises: 
 (a′) heating the liquid compound belonging to the group of sterically hindered phenols (a) to a temperature ranging from 60° C. to 180° C., under stirring;    (b′) adding the solid compound belonging to the group of sterically hindered phenols (b), maintaining the temperature within the range of 60° C. to 180° C., and maintaining the whole mixture under stirring until the complete dissolution of said compound (b), for a time ranging from 5 minutes to 100 minutes, obtaining a liquid mixture.    
     
     
         5 . The process according to  claim 4 , wherein the weight ratios between the liquid compound belonging to the group of sterically hindered phenols (a) and the solid compound belonging to the group of sterically hindered phenols (b) range from 90:10 to 30:70.  
     
     
         6 . Polymeric compositions containing an organic polymer and an effective quantity of one of the stabilizing mixtures according to any of the previous claims.  
     
     
         7 . The polymeric compositions according to  claim 6 , wherein the stabilizing mixtures are used in a combination with other stabilizers.  
     
     
         8 . The polymeric compositions according to  claim 6  or 7, wherein the organic polymers are selected from aqueous emulsions of natural or synthetic rubbers such as natural latex or latexes based on carboxylated styrene-butadiene copolymers.  
     
     
         9 . The polymeric compositions according to  claim 6  or 7, wherein the organic polymers are selected from natural or synthetic rubbers such as acrylic rubbers, nitrile rubbers, thermoplastic rubbers, polyisoprene, polybutadiene, polychloroprene, SBR, EPDM, either before or after vulcanization.  
     
     
         10 . End-products obtained from the processing of the polymeric compositions according to any of the claims from 6 to 9.  
     
     
         11 . A method for stabilizing organic polymers against degradation caused by oxygen, heat and/or light, which comprises the addition to said organic polymers of the stabilizing mixtures according to any of the claims from 1 to 5.