| 摘要 |
A process for producing a solid polymer or copolymer of isoprene in which at least 90% of the isoprene units are united cis-1, 4, and containing not more than 49 mol per cent comonomer is characterized by (a) polymerizing the monomer(s) at below 10 DEG C. in a volatile inert hydrocarbon medium, having a boiling point below the polymerization temperature and capable of dissolving 0,5%-5% of the polymer, using a catalyst prepared from (1) a titanium compound in which the titanium has a valence of at least 3 and (2) a hydrocarbon aluminium in which an average of at least two of the valence bonds of the aluminium are attached to a hydrocarbon radical through a carbon-to-aluminium bond; and in which the Ti/Al proportions are between 0,75-1 and 0,95-1 and then carrying out steps (b) and (c) separately and simultaneously, step (b) being contacting the slurry polymer with either a quench liquid and water or with deaerated water to produce a separable aqueous catalyst layer and removing the aqueous catalyst layer from the polymer slurry, while step (c) comprises combining the polymer slurry of step (b) with from 1/2 -2 volumes of water for every volume of slurry, and removing the volatile inert medium at at least 55 DEG C. to produce a slurry of polymer in water and then (d) separating off the polymer. The preferred catalyst is prepared from titanium tetrachloride and trialkyl aluminium; at least 95 mol per cent isoprene is preferably used; the heat of reaction may be carried away by refluxing the volatile inert hydrocarbon, e.g. n-butane; specified copolymerizable materials are propylene, butene, pentene, 1-hexene, 1-octene, styrene, vinyl toluene, butadiene, piperylene, 2-ethyl-butadiene, and 2-phenyl butadiene; the quench liquid may be water containing an organic solvent, e.g. acetone or a water containing lower aliphatic alcohol; while an antioxidant may be added after step (a) and a non-ionic surface-active material in step (c). Apparatus for carrying out the process is described. Specification 827,365 is referred to. |
