Liquid and gel-like low molecular weight ethylene polymers
View Patent ↗The subject invention pertains to homogeneous liquid low molecular weight ethylene/alpha-olefin polymers having a number average molecular weight (Mn) as determined by gel permeation chromatography, of less than 25,000, a total crystallinity, as measured by DSC, of less than 10%, and a pour point, as measured by ASTM D97, of less than 50° C. The subject invention also pertains to homogeneous gel-like low molecular weight ethylene/alpha-olefin polymers having a number average molecular weight (Mn) as determined by gel permeation chromatography, of less than 25,000, a total crystallinity, as measured by DSC, of less than 50%, and a pour point, as measured by ASTM D97, of less than 90° C.
1. A process comprising reacting ethylene and at least one ethylenically unsaturated comonomer at a reaction temperature of at least 80° C., in the absence of hydrogen, and in the presence of a single site catalyst, to form a homogeneous substantially linear, liquid low molecular weight ethylene/alpha-olefin polymer having:
a) a number average molecular weight (Mn), as determined by gel permeation chromatography, of less than 15,000;
b) a comonomer content of greater than 15 mol percent;
c) a total crystallinity, as measured by DSC, of less than 10%;
d) a pour point, as measured by ASTM D97, of less than 50° C., and
wherein the polymer is prepared in the presence of a constrained geometry catalyst, of the Formula III:
wherein:
M is titanium, zirconium or hafnium, bound in an η 5 bonding mode to the cyclopentadienyl group;
R′ each occurrence is independently selected from the group consisting of hydrogen, silyl, alkyl, aryl, and combinations thereof, having up to 10 carbon or silicon atoms;
E is silicon or carbon;
X independently each occurrence is hydride, halo, alkyl, aryl, aryloxy or alkoxy of up to 10 carbons;
m is 1 or 2; and n is 1 or 2 depending on the valence of M.
2. The process of claim 1 , wherein the alpha-olefin of the ethylene/alpha-olefin polymer is a C3-C8 alpha-olefin.
3. The process of claim 1 , wherein the ethylene/alpha-olefin polymer has a glass transition temperature (Tg) less than −30° C.
4. The process of claim 1 , wherein the ethylene/alpha-olefin polymer has a percent crystallinity, as measured by DSC, less than 5.
5. The process of claim 1 , wherein the ethylene/alpha-olefin polymer has a comonomer content of greater than 30 mol percent.
6. The process of claim 1 , wherein the ethylene/alpha-olefin polymer has a number average molecular weight (Mn) less than 11,000.
7. The process of claim 1 , wherein the reaction temperature is from 100° C. to 150° C.
8. The process of claim 1 , wherein the process is a continuous polymerization process.
9. The process of claim 8 , wherein the process is a continuous solution polymerization process.
10. A process comprising reacting ethylene and at least one ethylenically unsaturated comonomer, at a reaction temperature of at least 80° C., in the absence of hydrogen, and in the presence of a single site catalyst, to form a homogeneous substantially linear, gel-like low molecular weight ethylene/alpha-olefin polymer having:
a) a number average molecular weight (Mn), as determined by gel permeation chromatography, of less than 15,000;
b) a comonomer content of greater than 10 mol percent;
c) a total crystallinity, as measured by DSC, of less than 50%;
d) a pour point, as measured by ASTM D97, of less than 90° C., and
wherein the polymer is prepared in the presence of a constrained geometry catalyst, of the Formula III:
wherein:
M is titanium, zirconium or hafnium, bound in an η 5 bonding mode to the cyclopentadienyl group;
R′ each occurrence is independently selected from the group consisting of hydrogen, silyl, alkyl, aryl, and combinations thereof, having up to 10 carbon or silicon atoms;
E is silicon or carbon;
X independently each occurrence is hydride, halo, alkyl, aryl, aryloxy or alkoxy of up to 10 carbons;
m is 1 or 2; and n is 1 or 2 depending on the valence of M.
11. The process of claim 10 , wherein the alpha-olefin of the ethylene/alpha-olefin polymer is a C3-C8 alpha-olefin.
12. The process of claim 10 , wherein the ethylene/alpha-olefin polymer has a glass transition temperature (Tg) less than −30° C.
13. The process of claim 10 , wherein the ethylene/alpha-olefin polymer has a percent crystallinity, as measured by DSC, less than 30%.
14. The process of claim 10 , wherein the ethylene/alpha-olefin polymer has a comonomer content of greater than 13 mol percent.
15. The process of claim 10 , wherein the ethylene/alpha-olefin polymer has a number average molecular weight (Mn) less than 11,000.
16. The process of claim 10 , wherein the reaction temperature is from 100° C. to 150° C.
17. The process of claim 10 , wherein the process is a continuous polymerization process.
18. The process of claim 17 , wherein the process is a continuous solution polymerization process.