Exxon Research and Engineering Company

Robert Roper

Martin Leo Gorbaty

Kenneth W Powers

Neil F Newman

Arthur W Langer, Jr

Roger K West

Pierre T Hous

A solution of butyl rubber in an inert solution such as n-hexane is halogenated in a continuous process using bromine chloride vapor and high intensity mixing means for both the halogenation and subsequent neutralization steps. Adjustment of the mole ratio of bromine chloride to isoprene, where an isobutylene-isoprene butyl copolymer is used, to less than about 1.5 to 1 prevents overhalogenation and significant molecular weight loss, while the use of bromine chloride vapor results in improved process safety. The doubly halogenated product, containing both bromine and chlorine in its structure can be vulcanized in the absence of sulfur, e.g., with zinc oxide. It is particularly useful in rubber compositions where the singly halogenated product is employed, but demonstrates product performance advantages compared to both brominated butyl rubber and chlorinated butyl rubber.

Continuous process for the preparation of bromochlorinated butyl rubber

Isobutylene-based elastomers containing 3-15 mol percent enchained cyclic diolefin such as cyclopentadiene, and other comonomers such as isoprene, piperylene and butadiene to allow for chemical modification with anhydride, carboxy, hydroxy, etc. to produce a one package through cure system.

Functional group containing cyclic diolefin butyl rubbers

A stabilized halogenated butyl rubber composition comprises halogenated butyl rubber, an alkali metal or alkaline earth metal carboxylate, an ether and an oxide or hydroxide of a Group IIA metal as exemplified by halogenated butyl rubber containing both bromine and chlorine stabilized with a composition comprising calcium stearate, polyethoxylated adducts of sorbitol esterified with from 1 to 6 moles of oleic acid and mixtures thereof, and calcium hydroxide. Halogenated butyl rubbers stabilized in the manner disclosed exhibit improved resistance to discoloration upon high temperature exposure, such as during the drying of polymers in the course of manufacture.

Stabilized halogenated butyl rubber

Novel graft copolymers of isobutylene-conjugated diene copolymeric backbones are prepared employing polymer lithiation wherein the polymeric lithiated complex is treated with an ether compound prior to a graft copolymerization reaction with styrene monomer whereby improved grafting efficiencies are obtained.

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Summit, NJ, United States of America

Robert Roper