Maleated high acid number high molecular weight polypropylene of low color
AssigneeEastman Chemical Company
InventorsThomas David Roberts, Stephen Wayne Coe
Life of this patent
Estimating the term…
Abstract
A process for the manufacture of maleated polypropylenes having an acid number greater than 6, a yellowness index color of no greater than 76, and a number average molecular weight of at least 20,000. The process for making the maleated polypropylenes includes forming a mixture of molten polypropylene and molten maleic anhydride in a reactor, introducing a free radical initiator into the molten mixture to produce a product having maleic anhydride grafted onto the polypropylene, and recovering a high acid number, high molecular weight maleated polypropylene of low color from the reactor.
Claims12
A process for making a maleated polypropylene having an acid number greater than 6, a yellowness index of no greater than 76, and a number average molecular weight of at least 20,000 comprising:
- a. forming a molten mixture of polypropylene and maleic anhydride,
- b. introducing a free radical initiator into said molten mixture to produce a maleated polypropylene product, and
- c. recovering the product,
- wherein the weight ratio of polypropylene to maleic anhydride is about 10 to 200, the molar ratio of polypropylene to free radical initiator is about 200 to 4,000, and the molar ratio of maleic anhydride to free radical initiator is about 1 to 70.
Dependencies are inferred from the claim text.