Particle size control of metallocene catalyst systems in loop slurry polymerization reactors
Catalyst compositions containing a metallocene compound, a solid activator, and a co-catalyst, in which the solid activator or the supported metallocene catalyst has a d50 average particle size of 15 to 50 μm and a particle size distribution of 0.5 to 1.5, can be contacted with an olefin in a loop slurry reactor to produce an olefin polymer. A representative ethylene-based polymer produced using the catalyst composition has excellent dart impact strength and low gels, and can be characterized by a HLMI from 4 to 10 g/10 min, a density from 0.944 to 0.955 g/cm 3 , a higher molecular weight component with a Mn from 280,000 to 440,000 g/mol, and a lower molecular weight component with a Mw from 30,000 to 45,000 g/mol and a ratio of Mz/Mw ranging from 2.3 to 3.4.
1. A solid activator comprising:
a fluorided solid oxide and/or a sulfated solid oxide;
wherein the solid activator has:
a d50 average particle size in a range from 15 to 50 μm; and
a particle size span in a range from 0.5 to 1.5.
2. The solid activator of claim 1 , wherein:
the d50 average particle size is in a range from 15 to 30 μm; and
the particle size span is in a range from 0.6 to 1.3.
3. The solid activator of claim 2 , wherein an amount of the solid activator having:
a particle size of less than 10 μm is less than or equal to 8 wt %; and
a particle size of greater than 45 μm is less than or equal to 10 wt %.
4. The solid activator of claim 1 , wherein an amount of the solid activator having a particle size of greater than 45 μm is less than or equal to 5 wt %.
5. The solid activator of claim 1 , wherein the d50 average particle size is from 15 to 25 μm.
6. The solid activator of claim 1 , wherein the d50 average particle size is from 17 to 25 μm.
7. The solid activator of claim 1 , wherein the particle size span is from 0.7 to 1.2.
8. The solid activator of claim 1 , wherein the particle size span is from 0.6 to 1.1.
9. The solid activator of claim 8 , wherein the d50 average particle size is from 17 to 27 μm.
10. The solid activator of claim 8 , wherein the d50 average particle size is from 20 to 30 μm.
11. The solid activator of claim 1 , wherein an amount of the solid activator having a particle size of less than 10 μm is less than or equal to 5 wt %.
12. The solid activator of claim 11 , wherein the d50 average particle size is from 15 to 25 μm.
13. The solid activator of claim 11 , wherein the particle size span is from 0.7 to 1.2.
14. The solid activator of claim 11 , wherein the d50 average particle size is from 20 to 30 μm.
15. A solid activator comprising:
fluorided alumina, sulfated alumina, fluorided silica-alumina, sulfated silica-alumina, fluorided silica-coated alumina, fluorided-chlorided silica-coated alumina, sulfated silica-coated alumina, or any combination thereof;
wherein the solid activator has:
a d50 average particle size in a range from 15 to 50 μm; and
a particle size span in a range from 0.5 to 1.5.
16. The solid activator of claim 15 , wherein:
the d50 average particle size is in a range from 17 to 27 μm; and
the particle size span is in a range from 0.6 to 1.3.
17. The solid activator of claim 16 , wherein an amount of the solid activator having:
a particle size of less than 10 μm is less than or equal to 5 wt %; and
a particle size of greater than 45 μm is less than or equal to 5 wt %.
18. The solid activator of claim 15 , wherein:
the d50 average particle size is from 17 to 25 μm; and
the particle size span is from 0.6 to 1.1.
19. The solid activator of claim 15 , wherein:
the d50 average particle size is from 17 to 25 μm; and
the particle size span is from 0.7 to 1.2.
20. The solid activator of claim 15 , wherein an amount of the solid activator having:
a particle size of less than 10 μm is less than or equal to 2 wt %; and
a particle size of greater than 45 μm is less than or equal to 2 wt %.
21. The solid activator of claim 15 , wherein the solid activator has a ratio of d90/d10 from 1.8 to 3.