| 摘要 |
Linear polyethylene of particle size less than 50 microns is produced by a process which comprises subjecting linear polyethylene having a density of at least 0.950, a melt index below 100 and a particle size of at least 50 microns, to a chain scission treatment until the melt index of the polymer is at least 100, and mechanically comminuting the product. Chain scission may be effected by oxidation below the melting point in an oven, inert non-solvent liquid medium or fluidized bed, by oxidizing the molten polymer, or by thermal degradation. Oxidation may be effected with air or other oxygen containing gases in the presence of a promoter, e.g. organic peroxides, ozone and dinitrogen tetroxide. Comminution may be effected in hammer mills or fluid energy mills operated with compressed air. The products may be used in fluid bed coating of metal articles. |
