| 摘要 |
A process for dispersing fine particle size carbon blacks in low density polyethylene whereby an initially prepared carbon black-low density polyethylene masterbatch, consisting of from 20-50 percent by weight carbon black, is let-down by intensive mixing, in a dry blended mixture of low density polyethylene and high density polyethylene, or propylene polymer, to form an intermediate masterbatch, which is further let-down in low density polyethylene by a second intensive mixing stage. The proportions of each component are chosen to yield a final product consisting of (on a weight basis) from 1-5% carbon black, 1-10% high density polyethylene or propylene polymer, and at least 50% of the remainder being low density polyethylene. The final products so obtained exhibit good carbon black dispersion on a microscopic basis and are essentially free of carbon black agglomerates, the type of which are usually formed by the more standard processes wherein the initial masterbatch is simply let-down into low density polyethylene by only a single intensive mixing stage.
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