Process for the production of water and solvent-free halobutyl rubbers

Abstract

The present invention relates to water and solvent-free halogenated butyl rubber products as a process for the production thereof. The process comprises at least the steps of: a.) treating a fluid containing at least one halogenated butyl rubber and at least one volatile compound in at least one concentrator unit, b.) reheating the concentrated fluid and c.) feeding the reheated concentrated fluid into at least one extruder.

1 . Process of removing volatile compounds from a fluid (F) containing at least one halogenated butyl rubber and at least one volatile compound which comprises at least the steps of:
 a) treating the fluid (F) in at least one concentrator unit comprising at least a heater ( 2 ), a degassing vessel ( 4 ) and a vapor line ( 4 . 1 ), whereby the fluid (F) is heated, the heated fluid (G) is fed into a degassing vessel ( 4 ) where part of the volatile compounds are removed via the vapor line ( 4 . 1 ) to obtain a concentrated fluid (H),   b) reheating the concentrated fluid (H) from step a) in at least one reheating unit ( 6 ) to obtain a reheated concentrated fluid (L);   c) feeding the reheated concentrated fluid (L) from step b) into at least one extruder unit comprising at least an extruder degassing section comprising at least a conveying section ( 16 ), a vent port ( 15 ) with one or more vapor lines ( 15 . 1 ), a accumulating section ( 20 ) and an outlet section ( 22 ), whereby volatile compounds are removed through the vent ports ( 15 ) and vapor lines ( 15 . 1 );   
       whereby the product (P) obtained at the outlet section ( 22 ) is substantially five of volatile compounds. 
     
     
         2 . The process pursuant to  claim 1 , characterized in that the reheated concentrated fluid (L) is free-flowing. 
     
     
         3 . The process pursuant to  claim 1 , characterized in that the halogenated butyl rubber is bromobutyl rubber. 
     
     
         4 . The process pursuant to  claims 1  to  3 , characterized in that the Fluid (F) contains from 3 to 50 wt % of a halogenated butyl rubber and from 60 to 97 wt % volatile compounds, whereby the aforementioned components add up to 90 to 100 of the total mass of fluid (F). 
     
     
         5 . The process pursuant to  claims 1  to  4 , characterized in that the degassing vessel ( 4 ) is designed in the shape of a cyclone and has at least a torisperical shaped bottom to facilitate removal of concentrated fluid (H). 
     
     
         6 . The process pursuant to  claims 1  to  5 , characterized in that the extruder unit comprises an extruder selected from the group consisting of single and multiscrew extruders. 
     
     
         7 . The process pursuant to  claims 1  to  6 , characterized in that the extruder unit comprises means to operate separate zones of the extruder independently of each other at different temperatures so that the zones can either be heated, unheated or cooled. 
     
     
         8 . The process pursuant to  claims 1  to  7 , characterized in that the vent ports ( 15 ) comprise means to prevent the reheated concentrated fluid (L) or the Product (P), from coming out of the vent ports and that the means are stuffer screws. 
     
     
         9 . The process pursuant to  claims 1  to  8 , characterized in that a stripping agent is added in the extruder unit. 
     
     
         10 . The process pursuant to  claims 1  to  9 , characterized in that the extruder unit comprises at least one extruder degassing section in upstream direction. 
     
     
         11 . The process pursuant to  claims 1  to  10 , characterized in that fluid (F) is obtained by a process of removing hydrophilic compounds and optionally water from a crude fluid (A) containing at least one non-volatile polymer, at least one volatile organic compound, one or more hydrophilic compounds and optionally water which comprises at least the step of
 pre a) treating the crude fluid (A) in at least one pre-washing unit comprising at least a separating apparatus ( 26 ), whereby the fluid (A) is mixed with water to obtain an organic phase ( 28 ) comprising primarily non-volatile polymer and volatile organic compounds and an aqueous phase ( 27 ) comprising primarily water and hydrophilic compounds, and whereby the organic phase ( 28 ) is separated from the aqueous phase ( 27 ) in a separating apparatus ( 26 ) and further used as fluid F and whereby at least a part of the aqueous phase ( 27 ) is removed from the separating apparatus (fluid C). 
 
     
     
         12 . The process pursuant to  claims 1  to  11 , characterized in that fluid (A) or fluid (F) is obtained by a process comprising at least the steps of
 I) providing a reaction medium comprising
 a common aliphatic medium comprising at least 50 wt.-% of one or more aliphatic hydrocarbons having a boiling point in the range of 45° C. to 80° C. at a pressure of 1013 hPa, and 
 a monomer mixture comprising at least one isoolefin monomer, at least one multiolefin monomer and either no or at least one other co-polymerizable monomer 
 in a mass ratio of monomer mixture to common aliphatic medium of from 40:60 to 99:1 
 
 II) polymerizing the monomer mixture within the reaction medium to form a rubber solution comprising a rubber polymer which is at least substantially dissolved in the medium comprising the common aliphatic medium and residual monomers of the monomer mixture; 
 III) separating residual monomers of the monomer mixture from the rubber solution to form a separated rubber solution comprising the rubber and the common aliphatic medium, 
 IV) halogenating the rubber in the separated rubber solution using a halogenating agent. 
 
     
     
         13 . The process pursuant to  claim 12 , characterized in that the halogenating agent is a brominating agent. 
     
     
         14 . The process pursuant to  claim 13 , characterized in that the brominating agent is at least partially regenerated by an oxidizing agent.