Polymer Compositions and Methods of Making Them
AssigneeExxonMobil Chemical Patents Inc.
InventorPeriagaram S. Ravishankar
Life of this patent
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Abstract
The present disclosure is directed to polymer compositions that can be useful as viscosity modifiers, comprising (a) a first ethylene-α-olefin copolymer having an ethylene content of from about 60 to about 80 wt % and (b) a second ethylene-α-olefin copolymer having an ethylene content of from about 40 to about 60 wt %. The polymer composition comprises about 35 wt % to about 50 wt of the first ethylene-α-olefin copolymer and about 50 wt % to about 65 wt % of the second ethylene-α-olefin copolymer. The polymer compositions are made by comprising producing a first ethylene-α-olefin copolymer in a first reactor, directing the first copolymer to a second reactor, producing the second ethylene-α-olefin copolymer in the second reactor and forming the polymer composition.
Claims24
A method of making a polymer composition, comprising the steps of:
- (i) feeding a first ethylene monomer, a first propylene monomer, a first solvent, and a first metallocene catalyst to a first reactor to form a first effluent comprising a first ethylene-propylene copolymer, where the first ethylene-propylene copolymer comprises from about 60 wt % to about 85 wt % ethylene-derived units and from about 15 wt % to about 40 wt % propylene-derived units, and where the first ethylene-propylene copolymer has a MFR of greater than 10 g/10 min;
- (ii) feeding the first effluent from the first reactor, a second ethylene monomer, a second propylene comonomer, a second solvent, and optionally a second metallocene catalyst to a second reactor to form a second effluent comprising the first ethylene-propylene copolymer and a second ethylene-propylene copolymer, where the second ethylene-propylene copolymer comprises from about 40 wt % to about 60 wt % ethylene-derived units and from 40 wt % to about 60 wt % propylene-derived units;
- (iii) devolatizing the second effluent to form a concentrated polymer stream comprising a molten polymer composition and less than 1 wt % solvent;
- and
- (iv) pelletizing the molten polymer composition to form the polymer composition, where the polymer composition comprises from about 35 wt % to about 50 wt % of the first ethylene-propylene copolymer and from about 50 wt % to about 65 wt % of the second ethylene-propylene copolymer, and where the polymer composition comprises 50 wt % to 70 wt % ethylene-derived units.
A polymer composition comprising
- (a) a first ethylene-propylene copolymer comprising from about 60 wt % to about 85 wt % ethylene-derived units and from about 15 wt % to about 40 wt % propylene-derived units, wherein the first ethylene-propylene copolymer has an MFR of greater than 10 g/10 min, a weight-average molecular weight (Mw) of less than about 70,000, and a crystallinity at 25° C. of less than 5%;
- and
- (b) a second ethylene-propylene copolymer comprising from about 40 wt % to about 60 wt % ethylene-derived units and from about 40 wt % to about 60 wt % propylene-derived units, wherein the second ethylene-propylene copolymer has an MFR of at least 2 g/10 min, a weight-average molecular weight (Mw) of less than 130,000, and a crystallinity at 25° C. of less than 5%;
- wherein the polymer composition comprises from about 35 wt % to about 50 wt % of the first ethylene-propylene copolymer and about 50 wt % to about 65 wt % of the second ethylene-propylene copolymer;
- and
- wherein the polymer composition comprises from about 50 wt % to about 70 wt % ethylene-derived units.
Dependencies are inferred from the claim text.