Abstract: Olefin polymer chlorination products having improved handling properties are prepared by reacting, in a fluidized-bed state, certain free-flowing, high bulk density linear olefin polymer powders with gaseous chlorine. The olefin polymer powder used is characterized by having a flowability measured as angle of repose in the range of from about 24.degree. to about 28.degree., a bulk density in the range of from about 25 to about 35 pounds/cubic foot and a surface area in the range of from about 2 to about 4 square meters/gram. The individual particles of the olefin polymer particle are characterized by having particle sizes predominantly in the range of from about 300 to about 600 microns, and porosity sufficient to provide an average free volume within individual particles in the range of from about 20 to about 45 volume percent based on total particle volume.

Abstract: Chlorinated olefin polymer compositions having unexpectedly high tensile impact strength values and resistance to ignition and burning are composed essentially of an admixture of (1) a normally solid, linear olefin polymer having a bulk density of from about 22 to about 36 pounds/cubic foot with the individual particles thereof being predominantly in the range of at least 300 to about 800 microns in size, the olefin polymer having from about 1 to about 20 percent by weight of chemically combined chlorine substantially heterogeneously distributed along the outer surfaces of the polymer particles; such chlorine being introduced in the substantial absence of oxygen and at temperatures not substantially exceeding about 90.degree. C. while the olefin polymer particles are maintained in a fluidized bed state; and (2) from about 0.1 to about 10 percent based on polymer weight of antimony trioxide, and, optionally, up to about 5 percent based on polymer weight of certain bromine containing compounds.