GB1336756A - Partially hydrogenated block copolymer its hydrolhalogenated derivative and their preparation - Google Patents

Abstract

1336756 Hydrogenated block copolymers SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ BV 21 May 1971 [22 May 1970 22 July 1970] 16264/71 Heading C3P A partially hydrogenated block copolymer having, prior to hydrogenation, at least one polymer block of an alkenyl aromatic hydrocarbon and at least one polybutadiene block wherein the latter block has 8 to 80% of 1, 2- structure, at least 50% of the 1, 2-unsaturation and not more than 50% of the 1, 4-structure being saturated by hydrogenation, the alkenyl aromatic hydrocarbon polymer block preferably being substantially unhydrogenated. The hydrogenation is performed in the presence of a cobalt, nickel or iron carboxylate, alkoxide or acetylacetonate and an aluminium alkyl at 20 to 100‹C and 1 to 105 kg/cm<SP>2</SP> of hydrogen pressure. The product may be hydro-halogenated at 0 to 100‹C under a pressure of 1 to 30 atm. by exposure of a solution of the partially hydrogenated product in an inert solvent to anhydrous hydrogen halide gas. In examples, polystyrene (13,000 or 14,000)-polybutadiene (64,000 or 68,000)-polystyrene (15,000) block copolymer is hydrogenated using a nickel acetylacetonate-triethyl aluminium catalyst, and then hydrochlorinated or hydrobrominated. The products are fire resistant, the hydrobrominated product being self-extinguishing, the hydrochlorinated product requiring the addition of tribasic lead silicate-sulphate (or dibasic lead phthalate or barium cadmium compounds), and/or antimony trioxide, and/or tri (2, 3-dibromopropyl) phosphate.