| 摘要 |
<p>Polypropylene waxes having molecular weights in the range 1000 to 8000 and densities of at least 0,90 are prepared by heating crystalline polypropylene of density at least 0,90 and an average molecular weight of at least 20,000 at 300 DEG C. to 450 DEG C. until the molecular weight is reduced to a value within the range 1,000 to 8,000. The heating is preferably carried out in the absence of oxygen, e.g. in an inert atmosphere or in a solvent medium or under a vacuum. Specification 852,432 is referred to.</p> |
