GB606112A - Process for recovering cyclopentadiene - Google Patents

Abstract

Benzol forerunnings containing cyclopentadiene are stored at atmospheric temperatures and pressures out of contact with oxygen or oxygen-containing gas to polymerize cyclopentadiene to the dimer with at most minor amounts of higher polymers, other constituents originally present are removed by distillation at not more than 120 DEG C. to avoid depolymerization and the dicyclopentadiene purified. The forerunnings, which must be substantially free of benzene and its homologues, are stored in closed containers at not substantially below 15 DEG C. or above 40 DEG C. A halide catalyst such as stannic chloride or boron fluoride may be added. The storage time varies from a few days to a few weeks. After the distillation, the residue is fractionated under vacuum to recover the dimer. In an example, forerunnings of B.R. 31-46 DEG C. are stored at 22-25.5 DEG C. for 34 days and solid dicyclopentadiene recovered. This may be transported in an inert atmosphere such as natural gas or nitrogen, and depolymerized as required to cyclopentadiene for use in the production of synthetic rubber or, with maleic anhydride, resins.ALSO:Benzol forerunnings containing cyclopentadiene are stored at atmospheric temperatures and pressures out of contact with oxygen or oxygen-containing gas to polymerize cyclopentadiene to the dimer with at most minor amounts of higher polymers, other constituents originally present are removed by distillation at not more than 120 DEG C. to avoid depolymerization and the dicyclopentadiene purified. The forerunnings, which must be substantially free of benzene and its homologues, are stored in closed containers at not substantially below 15 DEG C. or above 40 DEG C. A halide catalyst such as stannic chloride or boron fluoride may be added. The storage time varies from a few days to a few weeks. After the distillation, the residue is fractionated under vacuum to recover the dimer. In an example, forerunnings of B.R. 31-46 DEG C. are stored at 22-25.5 DEG C. for 34 days, and solid dicyclopentadiene recovered. This may be transported in an inert atmosphere such as natural gas or nitrogen, and depolymerized as required to cyclopentadiene for use in the production of synthetic rubber or, with maleic anhydride, resins.