Halogenation of butadiene polymers in mixed solvents
AssigneePPG Industries, Inc.
InventorPatrick E. Hillman
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Abstract
Polybutadiene having high cis-1,4-configuration and dissolved in substantially anhydrous liquid organic solvent is reacted with chlorine, bromine or a mixture thereof. The solvent consists essentially of a mixture of one or more perhalogenated alkanes and one or more partially halogenated alkanes and fine particles of substantially thermoplastic halogenated polybutadiene precipitate from the solvent. The fine particles are separated from the bulk of the solvent.
Claims24
In a process for producing substantially thermoplastic halogenated butadiene polymer wherein butadiene polymer dissolved in liquid organic solvent is reacted with chlorine, bromine or a mixture thereof, the improvement wherein
- a. said solvent consists essentially of a mixture of one or more prehalogenated alkanes having one to about two carbon atoms and one or more partially halogenated alkanes having one to about two carbon atoms,
- b. fine particles of said substantially thermoplastic halogenated butadiene polymer having a solubility index of at least about 50 precipitate from said solvent during said reaction, and
- c. said precipitated fine particles are separated from the bulk of said solvent.
In a process for producing substantially thermoplastic chlorinated butadiene polymer wherein polymer dissolved in liquid organic solvent is reacted with chlorine, the improvement wherein
- a. said butadiene polymer is polybutadiene having at least about 90 mole percent cis-1,4-configuration,
- b. said solvent consists essentially of a mixture of carbon tetrachloride and methylene chloride,
- c. fine particles of substantially thermoplastic chlorinated butadiene polymer having a solubility index of at least about 50 precipitate from said solvent during said reaction, and
- d. said precipitated fine particles are separated from the bulk of said solvent.
Dependencies are inferred from the claim text.