Process for halogenation of polymers

Claim 1

A PROCESS WHICH COMPRISES CHLORINATING A NORMALLY SOLID POLYMER OF AN ALIPHATIC 1-OLEFIN HAVING A MAXIMUM MONOMER CHAIN LENGTH OF 8 CARBON ATOMS AND NO BRANCHING NEARER THE DOUBLE BOND THAN THE 4-POSITION IN SOLUTION, IN SOLVENT SELECTED FROM THE GROUP CONSISTING OF 1,1,2,2-TETRACHLOROETHANE, CHLOREBENZENE, DICHLOROBENZENES AND MIXTURES OF THESE SOLVENTS, AT A TEMPERATURE IN THE RANGE FROM A TEMPERATURE SUFFICIENTLY HIGH TO DISSOLVE SAID POLYMER TO THE SOLVENT REFLUX TEMPERATURE TO OBTAIN A PARTIALLY CHLORINATED POLYMER CONTAINING UP TO ABOUT 20 WEIGHT PERCENT COMBINED CHLORINE WHICH PARTIALLY CHLORINATED POLYMER IS SOLUBLE AT ATMOSPHERIC PRESSURE IN A SOLVENT SELECTED FROM THE GROUP CONSISTING OF CARBON TETRACHLORIDE, CHLOROFORM, METHYLENE CHLORIDE, AND MIXTURES OF THESE SOLVENTS, WITHOUT EFFECTING SUBSTANTIAL HALOGENATION OF THE SOLVENT OF SAID FIRST-MENTIONED GROUP, DISSOLVING SAID PARTIALLY CHLORINATED POLYMER IN A SOLVENT SELECTED FROM THE LATTER-MENTIONED GROUP AND CONTINUING THE CHLORINATION IN THE RESULTING SOLUTION TO OBTAIN A MORE HIGHLY CHLORINATED POLYMER, THE ORIGINAL UNCHLORINATED POLYMER BEING SUBSTANTIALLY INSOLUBLE IN CARBON TETRACHLORIDE AT THOSE TEMPERATURES AT WHICH CARBON TETRACHLORIDE EXISTS AS A LIQUID AT ATMOSPHERIC PRESSURE.