Syndiotactic propylene polymers and lubricating oils comprising the same

Patent metadata

Field	Value
Publication number	US-10876063-B2
Application number	US-201515316133-A
Country	US
Kind code	B2
Filing date	Jun 18, 2015
Priority date	Jul 31, 2014
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

This disclosure relates to syndiotactic polymers containing units derived from propylene and units derived from C 4 to C 20 alpha olefins. The polymers can be prepared is slurry or solution polymerization processes using a zirconium-containing metallocene catalyst system. The polymers have a melt flow rate as determined by ASTM D-1238 (230° C., 2.16 kg) of from about 0.1 to about 20 g/10 min. The syndiotactic polymers are useful as viscosity index improvers.

First claim

What is claimed is:

1. A lubricating oil composition comprising:
(i) at least 50 wt % of a base oil based on the weight of the lubricating oil; and
(ii) a syndiotactic polymer containing units derived from at least one α-olefin having 4 to 10 carbon atoms and ≥50 mol % of units derived from propylene, wherein the polymer has a melt flow rate, as determined by ASTM D-1238 (2.16 kg, 230° C.), of about 1 g/10 m to about 10 g/10 min, and wherein the lubricating oil composition comprises about 0.1 wt % to about 10 wt % of the polymer based on the weight of the lubricating oil composition;
wherein the polymer is produced by a polymerization process comprising contacting propylene and at least one α-olefin having 4 to 10 carbon atoms with a catalyst system comprising a precatalyst compound and an activator in a reactor;
wherein the precatalyst compound is selected from those having the structure of formula (1), (2), (3), or (4);
wherein structure (1) has a Cs or pseudo-Cs symmetry and the following formula (1):

wherein
M is a zirconium;
L 1 is a unsubstituted fluorenyl, unsubstituted heterocyclopentapentalenyl, unsubstituted heterofluorenyl, substituted fluorenyl, substituted heterocyclopentapentalenyl, or substituted heterofluorenyl ligand with one or more symmetric or pseudo symmetric substituents, each substituent group being, independently, a radical group which is a hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, silylcarbyl or germylcarbyl, and optionally two or more adjacent substituents may join to form a substituted or unsubstituted, saturated, partially unsaturated or aromatic, cyclic or polycyclic substituent;
L 2 is a cyclopentadienyl ring or a substituted cyclopentadienyl ring with one or more symmetric or pseudo symmetric substituents in the 2 and 5 positions of the ring, each substituent group being, independently, a radical group which is a hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, silylcarbyl or germylcarbyl;
G is a bridging group; and
X are, independently, halogen, alkoxide, aryloxide, amide, phosphide, hydride radicals, hydrocarbyl radicals, substituted hydrocarbyl radicals, halocarbyl radicals, substituted halocarbyl radicals, silylcarbyl radicals, substituted silylcarbyl radicals, germylcarbyl radicals, or substituted germylcarbyl radicals; or both X are joined and bound to the metal atom to form a metallacycle ring containing from 3 to 20 carbon atoms; or both together can be an olefin, diolefin or aryne ligand; or both X can also be joined to form a anionic chelating ligand;
wherein structure (2) has Cs or pseudo-Cs symmetry and the following formula (2):

wherein:
M, L 1 , G, and X are the same as in structure (1);
J is a heteroatom from group 15;
R′ is a radical group which is a hydrocarbyl, substituted hydrocarbyl, halocarbyl, or substituted halocarbyl; and
L′ is a neutral Lewis base and w represents the number of L′ bonded to M where w is 0, 1, or 2, and optionally any L′ and any X may be bonded to one another;

wherein structure (3) has Cs or pseudo-Cs symmetry and the following formula (3):

wherein:
M and X are the same as in structure (1);
L 3 is a cyclopentadienyl ring optionally substituted in the 4 position of the ring, the substituent group being chosen from a radical group which is a hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, silylcarbyl or germylcarbyl;
L 4 is a substituted cyclopentadienyl ring with symmetric or pseudo symmetric substituents in the 3 and 5 positions of the ring, each substituent group being, independently, a radical group which is a hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, silylcarbyl or germylcarbyl; and
G′ and G″ are bridging groups; and

wherein structure (4) has C2 symmetry and the following formula (4):

wherein:
X is the same as in structure (1);
M is titanium;
O is oxygen;
N is nitrogen;
R 1 is a radical group which is a hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, silylcarbyl or germylcarbyl;
R 2 is a radical group which is a hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, silylcarbyl or germylcarbyl; and
RL 3 , R 4 and R 5 are independently hydrogen or a radical group which is a hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, silylcarbyl or germylcarbyl.

2. The lubricating oil composition of claim 1 , wherein the at least one α-olefin comprises 1-hexene.

3. The lubricating oil composition of claim 1 , wherein the lubricating oil composition comprises about 0.5 wt % to about 5 wt % of the polymer based on the weight of the lubricating oil composition.

4. The lubricating oil composition of claim 1 , wherein the base oil is selected from Group II base oil, Group III base oil, Group IV base oil, Group V base oil, and combinations thereof.

5. The lubricating oil composition of claim 1 , wherein the polymer has a thickening efficiency of greater than 1.5.

6. The lubricating oil composition of claim 1 , wherein the lubricating oil composition has at least one of: a kinematic viscosity at 40° C., as measured by ASTM D445-3, of greater than 50 cSt, and a kinematic viscosity at 100° C., as measured by ASTM D445-5, of greater than 10 cSt.

7. The lubricating oil composition of claim 1 , wherein the lubricating oil composition has a viscosity index, as calculated by ASTM D2270, of greater than 120.

8. The lubricating oil composition of claim 1 , wherein the precatalyst compound has the structure of formula (1) and has Cs or pseudo-Cs symmetry of formula (1a) or (1b);
wherein structure (1a) has the following formula (1a):

wherein each R a and R b are selected from hydrogen, halogen, hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, silylcarbyl, germylcarbyl or polar radicals, and optionally two or more adjacent substituents may join to form a substituted or unsubstituted, saturated, partially unsaturated or aromatic, cyclic or polycyclic substituent, with the proviso that each R a is the same and each R b is the same and allow the compound to be Cs-symmetric or pseudo Cs-symmetric;
each R c is a symmetric or pseudo symmetric substituent with respect to the other and is selected from hydrogen or a hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, silylcarbyl or germylcarbyl radicals; and
each R d is a symmetric or pseudo symmetric substituent with respect to the other and is selected from hydrogen or a hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, silylcarbyl or germylcarbyl radicals; and
wherein structure (1b) has the following formula (1b):

9. The lubricating oil composition of claim 1 , wherein the precatalyst compound has the structure of formula (3) and has Cs or pseudo-Cs symmetry of the following structure (3a):

wherein R e is selected from hydrogen, hydrocarbyl, su

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Dias Anthony J
• Canich Jo Ann M
• Rodriguez George
• Farng Liehpao O
• Schauder Jean-Roch H

Classifications

• C10M143/00 Primary

  Lubricating compositions characterised by the additive being a macromolecular hydrocarbon or such hydrocarbon modified by oxidation · CPC title

• C10M2207/026

  with tertiary alkyl groups · CPC title

• C10M2203/1025

  used as base material · CPC title

• C08F4/65925

  two cyclopentadienyl rings being mutually non-bridged · CPC title

• C08F2500/16

  Syndiotactic · CPC title