Process for the preparation of a thermoplastic elastomer comprising a partially vulcanized rubber concentrate

Abstract

Process for the preparation of a thermoplastic elastomer by melt mixing a partially vulcanized rubber concentrate, a thermoplastic polymer and/or additives, optionally oil and a curing agent. The partially vulcanized rubber concentrate is prepared by melt mixing at least one elastomer and optionally oil with a thermoplastic polymer and a curing agent. The elastomer may be EPDM or EPM. The thermoplastic polymer may be chosen from a thermoplastic polyolefine. Usefull curing agents are for example sulfur, sulfurous compounds, metal oxides, maleimides, phenol resins or peroxides.

1 . Process for the preparation of a thermoplastic elastomer by melt mixing 
 a. a partially vulcanized rubber concentrate    b. a thermoplastic polymer and/or additives    c. optionally oil and    d. a curing agent.    
     
     
         2 . Process according to  claim 1  characterized in that the melt mixing is carried out in a twin-screw extruder.  
     
     
         3 . Process according to  claim 1  characterized in that the melt mixing is carried out in a single screw extruder.  
     
     
         4 . Process according to any one of the claims  1 - 3  characterized in that the partially vulcanized rubber concentrate (a) is prepared by melt mixing: 
 e. at least one elastomer and optionally oil  
 f. at least one thermoplastic polymer  
 g. a curing agent.  
 
     
     
         5 . Process according to  claim 4  characterized in that the partially vulcanized rubber concentrate is prepared by melt mixing 
 e. 30 to 95 parts by weight of the elastomer(s) and 0-70 parts by weight of oil  
 f. 5 to 50 parts by weight of the thermoplastic polymer(s)  
 g. 0.1-10 parts by weight of the curing agent  
 whereby the sum of the parts by weight of the elastomer(s), the thermoplastic polymer(s), curing agent and oil is 100.  
 
     
     
         6 . Process according to any one of claims  4 - 5  characterized in that the elastomer is EPDM or EPM.  
     
     
         7 . Process according to claim  1 - 6  characterized in that the thermoplastic polymer is chosen from thermoplastic polyolefin homo- and copolymers, reactor TPO, polyamides, polycarbonate, polyesters, polysulfones, polylactones, polyacetals, acrylonitrile-butadiene-styrene (ABS) resins, polyphenylene oxide (PPO), polyphenylene sulfide (PPS), styrene-acrylonitrile (SAN) resins, polyimides, styrene maleic anhydride (SMA) and aromatic polyketones.  
     
     
         8 . Process according to  claim 7  characterized in that the thermoplastic polymer is a thermoplastic polyolefin homo- and copolymer.  
     
     
         9 . Process according to  claim 8  characterized in that the thermoplastic polymer is a polypropylene homopolymer.  
     
     
         10 . Process according to any one of claims  1 - 9  characterized in that the elastomer in the partially vulcanized rubber concentrate has a gel content higher than 50%.  
     
     
         11 . Process according to any one of claims  1 - 10  characterized in that the elastomer in the partially vulcanized rubber concentrate has a gel content higher than 70%.  
     
     
         12 . Process for the preparation of a thermoplastic elastomer according to claims  1 - 11  by melt mixing: 
 a. 10-90 parts by weight of the partially vulcanized rubber concentrate  
 b. 90-10 parts by weight of a the thermoplastic polymer and/or additives  
 c. 0-30 parts by weight of oil  
 d. 0.1-10 parts by weight of the curing agent  
 whereby the sum of the parts by weight of the partially vulcanized rubber concentrate, the thermoplastic polymer and/or additives, the oil and the curing agent is 100.  
 
     
     
         13 . Process according to any one of claims  1 - 12  characterized in that the curing agent is chosen from phenol resins, siloxanes or peroxides.