Abstract:
Provided are processes for making polymer compositions, especially those with reduced or no gel formation in lubricating oils as identified by rheological and visual gel tests and which are useful as viscosity modifiers. The processes described herein aim to achieve this objective by adjusting the concentrations of the hydrogen feed(s) in the first and/or second polymerization reaction zones, preferably such that (a) the hydrogen feed concentration in the first polymerization reaction zone is 0.0-1.0 wt %, based on total weight of feed(s) of hydrogen, ethylene monomer, a-olefin comonomer, and solvent into the first polymerization reaction zone, and/or (b) the hydrogen feed concentration in the second polymerization reaction zone is 0.0-0.5 wt %, based on total weight of feed(s) of hydrogen, ethylene monomer, a-olefin comonomer, and solvent into the second polymerization reaction zone.
Abstract:
Provided are processes for making polymer compositions, especially those with reduced or no gel formation in lubricating oils as identified by rheological and visual gel tests and which are useful as viscosity modifiers. The processes described herein aim to achieve this objective by adjusting the concentrations of the hydrogen feed(s) in the first and/or second polymerization reaction zones, preferably such that (a) the hydrogen feed concentration in the first polymerization reaction zone is 0.0-1.0 wt %, based on total weight of feed(s) of hydrogen, ethylene monomer, a-olefin comonomer, and solvent into the first polymerization reaction zone, and/or (b) the hydrogen feed concentration in the second polymerization reaction zone is 0.0-0.5 wt %, based on total weight of feed(s) of hydrogen, ethylene monomer, a-olefin comonomer, and solvent into the second polymerization reaction zone.
Abstract:
The present disclosure is directed to polymer compositions for use as viscosity modifiers comprising at least two ethylene-based copolymer components. The polymer composition comprises (a) a first ethylene-olefin copolymer and (b) a second ethylene-olefin copolymer. The first ethylene-olefin copolymer (a) has an ethylene content from about 60 to about 80 wt% and the second ethylene-olefin copolymer (b) has an ethylene content of less than about 60 wt%. The first ethylene-olefin copolymer(a) has a Melt Flow Rate Ratio (MFRR), defined as the ratio of the MFR measured at 230°C/21.6 kg and at 230°C/2.16 kg, of greater than 30 and optionally also has a Melt Flow Rate (MFR) of at least 10 about 1.5 g/10 min, measured by ASTM D 1238 condition L (230°C/2.16 kg).