GB401297A - Improvements in the manufacture and production of hydrocarbons of high molecular weight from isobutylene - Google Patents

Abstract

High molecular polymerization products are manufactured by polymerizing iso-olefines in the presence of an inorganic halide, preferably volatile, while maintaining the temperature continuously below -10 DEG C. Suitable inorganic halides are boron fluoride, boron fluoride charged with hydrofluoric acid, phosphorus trifluoride or pentafluoride, aluminium chloride, preferably in statu nascendi, e.g. as formed by the action of hydrogen chloride on aluminium, or solutions or double compounds p of the said halides, e.g. solutions in substances such as phenol or cresol in which they dissolve without decomposition whether with the formation of real solutions or of double compounds. Preferably the catalyst is brought into contact with the iso-olefine gradually, advantageously while moving the iso-olefine, e.g. by stirring, in order to avoid local overheating. The cooling may be effected externally by means of cooling baths or internally by adding to the reacting substances cold materials which have no unfavourable influence, e.g. solid carbon dioxide. The catalysts may be employed in very small amounts, e.g. less than 1 per cent in the case of boron fluoride, though higher percentages may be used, e.g. 3 or 5 per cent of aluminium chloride. Solvents, e.g. pentane, may be present during the reaction. The process is applicable particularly to the treatment of isobutylene, but also to the polymerization of other iso-olefines or products containing iso-olefines, e.g. cracking products which are liquid at ordinary temperatures, such as those obtained by cracking solid or liquid paraffin or naphthene hydrocarbons, e.g. hard or soft paraffin waxes, ceresine, heavy and middle oils, paraffin and petroleum fractions. In examples: (1) boron fluoride is led into liquid isobutylene cooled in a bath of carbon dioxide to -80 DEG C.; (2) as in (1) except that the reaction material is cooled to -60 to -70 DEG C. by throwing in solid carbon dioxide; (3) boron fluoride is led into a solution of isobutylene in pentane at -40 DEG C.; (4) and (5) mixtures of isobutylene and normal butylene are treated as in (2), the isobutylene being polymerized; (6) a mixture of natural gas gasoline, isobutylene and normal butylene is polymerized as in (2); the molecular weight of the product may be increased by depolymerizing by heating, if desired in the presence of catalysts, e.g. by heating to 300 DEG C. in the presence of phosphoric acid, and again polymerizing; (7) titanium chloride is added at intervals to isobutylene cooled with solid carbon dioxide; (8) as in (7) except that all the titanium chloride is added at the beginning; the reaction temperature is -80 DEG C.; (9) boron fluoride is led into a soft paraffin wax cracking product cooled initially to -60 DEG C. by acetone and carbon dioxide, the temperature not being allowed to exceed -40 DEG C.; (10) aluminium chips and mercury chloride are added to a cracking product as in (9), cooled initially to -20 DEG C., and hydrogen chloride gas is led in, the temperature not being allowed to exceed -15 DEG C. Specification 358,068 is referred to.