Patent GB-1200362-A (GB)
Title: Polymer composition
Inventor: CROUCH ROSALIE BROOKS
IPC: C08F210/06
Filed: 1967-07-28
Abstract: 1,200,362. Polymer composition. IMPERIAL CHEMICAL INDUSTRIES Ltd. 2 July, 1968 [28 July, 1967; 20 Nov., 1967; 14 June, 1968], Nos. 34836/67, 52710/67 and 28359/68. Heading C3P. A polymer composition comprises a crystalline polymer or copolymer of an α-olefine, which includes a minor proportion (not more than 25% by weight of the polymer composition) of a cationic polymer dispersed throughout the composition. The crystalline polymer may be a polymer of 4-methyl pentene-1, or propylene, and the cationic polymer may be derived from 4-methyl pentene-1, isobutylene, 3-methyl butene-1, 3-methyl pentene-1, 5-methyl hexene-1, 3-ethyl pentene-1, 3-methyl hexene-1, 4-methylhexene-1, allylbenzene or vinyl cyclohexane. The crystalline polymer may be a polymer of 4-methyl pentene-1 which has been sequentially polymerized with a non-linear 1-olefine, the homopolymer of which has a melting-point in excess of 275‹ C. The crystalline polymer may also contain linear 1-olefine units. The composition may be prepared by mixing the crystalline and cationic polymers or by a two-stage polymerization, one stage being a stereospecific polymerization stage and the other being a cationic polymerization stage, one stage following the other without terminating polymerization between the stages. In the instance wherein the first stage is the cationic polymerization stage, the catalyst may comprise a reaction product obtained by the reduction of titanium tetrachloride with an organo-aluminium compound, and the cationic polymerization activity of this product may be enhanced by treating the product with hydrogen chloride gas, a dialkylsilicon dihalide, carbon tetrachloride, hexachlorocyclopentadiene, bromine, water or orthophosphoric acid. After completion of the cationic polymerization stage, a Ziegler activator is added to initiate the stereospecific stage. A suitable activator is aluminium diethyl chloride. In the instance wherein the first stage is the stereospecific polymerization, the catalyst may comprise a titanium trichloride/dialkyl aluminium halide catalyst which may include a polymer of a non-linear 1-olefine such as 3- methyl pentene-1, the homopolymer of which has a melting-point in excess of 275‹ C. On completion of the stereospecific stage, a reagent is added to initiate the cationic stage, and suitable reagents are hydrogen chloride gas, carbon tetrachloride, hexachloropentadiene, bromine, water or orthophosphoric acid. The composition may also be obtained by preparing the crystalline polymer in the presence of the cationic polymer. In the examples, aluminium ethyl sesquichloride and titanium tetrachloride are mixed and heated in a hydrocarbon medium, and the titanium trichloride reaction product treated with hydrogen chloride or dimethyldichloro silane, wherein the activated catalyst cationically polymerizes 4-methyl pentene, and a Ziegler activator in the form of aluminium diethyl chloride is added to initiate stereo polymerization, the reaction being terminated by the addition of acetyl acetone in isopropyl alcohol. In another example, 4-methyl pentene, optionally under hydrogen, is polymerized with a mixture of diethyl aluminium chloride and the above titanium trichloride reaction product, the stereospecific stage being initiated by the addition of hydrogen chloride, hexachlorocyclopentadiene, bromine, water or orthophosphoric acid, the reaction being terminated by the addition of methanol. In further examples, (1) 4- methyl pentene is stereopolymerized with a titanium trichloride/diethyl aluminium chloride catalyst, cationic polymerization being initiated by the addition of carbon tetrachloride, (2) the catalyst in (1) is pretreated with a polymer of 4-methyl pentene-1 and 3-methyl pentene-1, and 4-methyl pentene stereopolymerized, the cationic stage being initiated by the addition of carbon tetrachloride or hydrogen chloride, (3) as in (2) wherein towards the completion of the stereospecific stage, 5-methyl hexene-1 or isobutylene is added, (4) using the catalyst of (2), propylene is stereopolymerized, 4-methyl pentene-1 and hydrogen chloride are added, and cationic polymerization carried out. Further examples describe the two-stage polymerization of 3-methyl butene-1, 3-methyl pentene-1 and 5-methyl hexene-1.