TECHNOLOGY FOR THE PRODUCTION OF BUTYL RUBBER (IIR) AND HALOBUTYL RUBBER (HIIR)

PROCESS FEATURES

Butyl rubber (IIR) is an elastomeric copolymer of isobutylene with small amounts of isoprene, offered in a range of polymer grades.
Halogenating the isoprene groups in IIR produces a rubber which could co-cure with elastomers such as NR, BR and SBR while preserving the essential properties of IIR. The commercial halobutyl rubbers, bromobutyl (BIIR) and chlorobutyl (CIIR), are more easily vulcanized than IIR.
The major application area is the tire industry, mainly, as IIR, for innertubes and tire curing bladders and, as HIIR, for inner liners.
The CONSER process, developed with the support of consultants and specialists having experience in production of butyl rubber, belongs to the well established slurry polymerization process, practiced by the leading world producers of butyl rubber.
CONSER can offer a technology for the production of butyl rubber (IIR) and halo-butyl rubber (HIIR ) fully competitive as consumption of raw materials, utilities and chemicals and as quality of the products.

REFERENCES

Company	Location	Capacity T/y
SIR	Italy	30000 (1)
YNCC	Korea	50000 (2)

(1) Only IIR
(2) Both IIR and HIIR (project study)

PROCESS DESCRIPTION

IIR PROCESS

The butyl rubber technology offered by CONSER is based on the following main steps:

Polymerization
Recycle compression and purification
Finishing

Polymerization

The butyl rubber is produced by co-polymerizing isobutylene with a small amount of isoprene, in a solution with methylchloride, at low temperature (close to –100°C) and with aluminium clorides as catalyst. In the flash vessel water replaces the organic solvent, thus producing a water slurry.

Recycle compression and purification

Unreacted monomers and solvent are flashed, compressed, dried and fractionated in a sequence of distillation columns to recover solvent and isobutylene, both recycled to the polymerization section, while all the impurities are purged out.

Finishing

The water polymer slurry from the reaction section is sent directly to the finishing, where it is dried, pressed, baled and packaged.

HIIR PROCESS

Part of the water polymer slurry from the polymerization is fed to the halogenation section:
here the water is replaced with hexane to produce a polymer solution which is fed first to the halogenation reactors and then to the neutralization system.
The hexane is finally removed and replaced again with water. The water slurry is dried, pressed, baled and packaged in a second finishing line.