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

A process of removing volatile compounds from a fluid (F) containing at least one nitrile rubber and volatile compounds, wherein the volatile compounds include water and volatile organic compounds, and wherein the process comprises:

• a) treating the fluid (F) in at least one concentrator unit comprising a heater, a degassing vessel and a first vapor line, whereby the treating comprises heating the fluid (F) in the heater to produce heated fluid (G), feeding the heated fluid (G) into degassing vessel, and degassing the heated fluid (G) and removing part of the volatile compounds via the first vapor line to obtain a concentrated fluid (H),
• b) reheating the concentrated fluid (H) from step a) in at least one reheating unit to obtain a reheated concentrated fluid (L);
• and
• c) feeding the reheated concentrated fluid (L) from step b) into at least one extruder unit comprising at least an extruder degassing section comprising a conveying section, a vent port with one or more second vapor lines, accumulating sections and an outlet section, and removing the volatile compounds through the vent ports and second vapor lines;
• whereby the reheated concentrated fluid (L) is free-flowing upon entering the extruder degassing section and the nitrile rubber obtained at the outlet section is substantially free of the volatile compounds,
• and wherein the nitrile rubber comprises
• (i) repeating units derived from at least one conjugated diene, at least one α,β-unsaturated nitrile and optionally one or more copolymerizable monomers and
• (ii) one or more structural element of the general formulae (I), (II), (III), (IV) or (V)
• wherein:
• Z represents H, branched or unbranched, saturated or one or more times unsaturated alkyl, saturated or one or more times unsaturated carbo- or hetercyclic residue, aryl, heteroaryl, arylalkyl, heteroarylalkyl, alkoxy, aryloxy, heteroaryloxy, amino, amide, hydroxyimino, carbamoyl, akoxycarbonyl, F, Cl, Br, I, hydroxy, phosphonato, phosphinato, alkylthio, arylthio, sulfanyl, thiocarboxy, sulfono, sulfino, sulfeno, sulfonyl, sulfamoyl, silyl, silyloxy, nitril, carbonyl, carboxy, oxycarbonyl, oxysulfonyl, oxo, thioxo, borate, selenate, epoxy, cyanate, thiocyanate, isocyanate, thioisocyanate and isocyanide,
• M represents repeating units derived from one or more monomers which are one or more times unsaturated, including conjugated or unconjugated dienes, alkynes and vinyl compounds, or a structural element derived from polymers comprising polyether, and polyalkylenoxides, polysiloxanes, polyols, polycarbonates, polyurethanes, polyisocyanates, polysaccharides, polyester and polyamides,
• n and m are same or different and are 0 to 10,000,
• t is 0 or 1, if n=0, and equals 1, if n≠0,
• X represents C(Z2), N(Z), P(Z), P(═O)(Z), S, S(═O) or S(═O)2 wherein Z has the same meaning as defined hereinabove,
• R (a) in case that m≠0 has the same meaning as the residue Z,
• (b) in case that m=0, represents H, a branched or unbranched, saturated, one or more times unsaturated alkyl, a saturated, one or more times unsaturated carbo- or heterocyclic residue, aryl, heteroaryl, arylalkyl, heteroarylalkyl, alkoxy, aryloxy, heteroaryloxy, amino, amido, carbamoyl, alkoxy, aryloxy, alkylthio, arylthio, sulfanyl, thiocarbonyl, sulfinyl, sulfono, sulfino, sulfena, sulfonyl, sulfamoyl, carbonyl, carboxy, oxycarbonyl, oxysulfonyl, axe, thioxo, epoxy, cyanate, thiocyanate, isocyanate, thioisocyanate or isocyanide.