In the polymerization of olefines by a process giving a mixture of polymers of higher and lower boiling point, a desired component is preferentially produced by the use as catalysts of acids of phosphorus or their acid esters or of compounds of boron fluoride containing a hydrogen atom removable by dissociation or compounds of boron fluoride with ethers, and by working in the presence of an added amount of a component whose formation is to be suppressed or, when the desired component is of lower boiling point, by continuously removing the same by distillation at a temperature and pressure such that the higher boiling component remains in the reaction zone. In examples: (1) propene is polymerized with phosphoric acid at 180 DEG C. and 20 atm. excess pressure in the presence of added isononene to give a product which is largely isododecene, or (2) in the presence of isododecene giving mainly isononene; (3) isobutene is treated with phosphoric acid at 80 DEG C. and 2 atm. in the presence of added tri-isobutene giving mainly di-isobutene; (4) isobutene-containing gas is treated with phosphoric acid at 150 DEG C. and 9 atm., di-isobutene being continuously distilled off and non-polymerizable gases allowed to escape. Di-isobutene is the chief product, minor amounts of tri-isobutene and higher polymers remaining as residue; (5) propene-containing gas is similarly converted to isononene when working at 180--200 DEG C., minor quantities of higher polymers such as isodedecene remaining. Specifications 314,932, 447,973, and 453,854 are referred to. The Provisional Specification is not limited to the use of the catalysts specified, and includes a further example in which an enriched coke oven gas containing propene and butene is treated with phosphoric acid at 170 DEG C. and 10--15 atm. excess pressure, the low boiling polymer being removed as formed.
展开▼
