Patent GB-957777-A (GB)
Title: Process for the manufacture of block copolymers
Inventor: GUENTHER LEHMANN DR
IPC: C08F297/08
Filed: 1960-06-07
Abstract: Titanium trichloride is made by reacting titanium tetrachloride with aluminium ethyl sesquichloride in a diesel oil medium at 0 DEG  C., collecting the precipitate formed and, after washing with diesel oil, treating it with aluminium diethyl monochloride at 40 DEG  C., followed by further washing. Other treatments of titanium tetrachloride with aluminium triethyl and/or aluminium ethyl chlorides are described. Specifications 799,395, 838,996, 909,461 and 943,199 are referred to.ALSO:Block copolymers of olefines and/or diolefines are made by the alternate addition of two or more such monomers to a polymerization mixture, each addition differing in composition from the preceding one and performing the polymerization with a catalyst made by reacting (1) a compound of titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafuium, tantalum, tungsten, thorium or uranium with (2) one or more aluminium alkyls and/or aluminium alkyl halides at a temperature between -20 and +40 DEG C. in an inert medium, the conditions being chosen so that aluminium trihalide and alkyl dihalide as reaction products are present in an amount of 0-30% mol of (1), while aluminium dialkyl halide is allowed to form in an amount of at least 100% mol of (1), aluminium alkyl dihalides soluble in the reaction medium being removed; if desired, from the solid catalyst substance by filtering the reaction mixture, and, if desired, after a thermal pre-treatment of the reslurried filter cake in the presence of a aluminium dialkyl halide, filtered again and washed with a hydrocarbon.  Suitable catalysts are made by reacting in a hydrocarbon medium:  (i) titanium tetrachloride and aluminium ethyl sesquichloride, followed by treatment with aluminium diethyl monochloride, the final product containing 1 mol of titanium trichloride per litre; (ii) titanium tetrachloride with a mixture of aluminium triethyl and aluminium ethyl sesquichloride; (iii) aluminium trichloride and aluminium triethyl, removing the precipitate formed, treating the solution with aluminium triethyl and then reacting with titanium tetrachloride; (v) aluminium trichloride and aluminium triethyl and then reacting with titanium tetrachloride; and (vi) vanadium triacetyl acetonate and aluminium diethyl monochloride. Prior to polymerization aluminium triethyl, mixed with aluminium diethyl monochloride if desired, may be added to catalyst compositions of the type described above.  The block copolymers may consist of homopolymeric and/or copolymeric blocks of olefines. The polymerization is effected in a hydrocarbon medium, and may be carried out by a continuous process in which the reaction mixture, after the polymerization of an olefine, is transferred to a different vessel where the polymerization of a different olefine is effected. If desired, the reaction mixture from two separate polymerizations may be combined in a third reaction vessel before continuing polymerization.  Between polymerizations the reaction vessels may be scavenged with hydrogen, thereby reducing the molecular weight of the block copolymers formed.  The examples describe the preparation of the following block copolymers: (1) polyethylene/polypropylene; (3) polyethylene/polybutene-1; (12) polyisoprene/poly(ethylene-co-propylene); (13) poly(2-methylhexadiene-1, 5)/poly(ethylene-co-propylene); and (14) polyethylene/poly(4-methylpentene-1). Specifications 799,395, 838,996, 909,461 and 943,199 are referred to.