Preparation of polyolefins having high molecular weights in...

Details Preparation of polyolefins having high molecular weights in... Preparation of polyolefins having high molecular weights in...

2004-04-01

2010-11-16

Harlan, Robert D. (Department: 1796)

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

Effecting a change in a polymerization process in response...

C526S901000, C526S943000, C526S352000, C526S073000

Reexamination Certificate

active

07834107

ABSTRACT:
Process for preparing polyolefins having high molecular weights in the presence of a catalyst comprising an organic transition metal compound in a gas-phase fluidized-bed reactor, where the polyolefins prepared have a melt flow rate at 2.16 kg and 190° C. in accordance with ISO 1133 of less than 4 g/10 min. According to the present invention, a start-up phase during which a polyolefin having an increased melt flow rate of above 4 g/10 min is produced for a transitional period is provided. In this way, trouble-free start-up of the reactor is ensured even in the case of polymer products having a high molecular weight and a melt flow rate below 4 g/10 min and even when using catalysts based on organic transition metal compounds, in particular metallocene catalysts.

REFERENCES:
patent: 4764056 (1988-08-01), Zentgraf et al.
patent: 5077358 (1991-12-01), Durand et al.
patent: 6255418 (2001-07-01), Jolly et al.
patent: 6265502 (2001-07-01), Herzog
patent: 6417302 (2002-07-01), Bohnen
patent: 6589905 (2003-07-01), Fischer et al.
patent: 6784261 (2004-08-01), Schopf et al.
patent: 6812185 (2004-11-01), Fischer et al.
patent: 2003/0236164 (2003-12-01), Fischer et al.
patent: 2004/0214970 (2004-10-01), Schopf et al.
patent: 2006/0142152 (2006-06-01), Coalter, III et al.
patent: 4241530 (1994-06-01), None
patent: 19710615 (1998-09-01), None
patent: 0089691 (1983-09-01), None
patent: 0226935 (1987-07-01), None
patent: 0475603 (1992-03-01), None
patent: 0571826 (1993-12-01), None
patent: 0692500 (1996-01-01), None
patent: 9109882 (1991-07-01), None
patent: 9600243 (1996-01-01), None
patent: 9736937 (1997-10-01), None
patent: 9822486 (1998-05-01), None
patent: 9840419 (1998-09-01), None
patent: 9900430 (1999-01-01), None
patent: 9903901 (1999-01-01), None
patent: 9906414 (1999-02-01), None
patent: 0005277 (2000-02-01), None
patent: 0024787 (2000-05-01), None
patent: 0031090 (2000-06-01), None
patent: 0109148 (2001-02-01), None
patent: 0141920 (2001-06-01), None
patent: 0250127 (2002-06-01), None
patent: 03022888 (2003-03-01), None
J. Michl et al., Editor,Chemical Reviews, American Chemical Society, Publications Division, vol. 100(4), p. 1167-1681 (2000).
H. Brintzinger et al., “ansa-Metallocene derivatives, XVII. Racemic andmesodiastereomers of group IV metallocene derivatives with symmetrically substituted, dimethylsilanediyl-bridged ligand frameworks. Crystal structure of R,S-Me2Si(3-t-Bu-5-MeC5H2)2ZrCl2,”Journal of Organometallic Chemistry, vol. 369, p. 359-370 (1989).
M. Brookhart et al., “Highly Active Iron and Cobalt Catalysts for the Polymerization of Ethylene,”J. Am. Chem. Soc., vol. 120(16), p. 4049-4050 (1998).
V. C. Gibson et al., “Novel olefin polymerzation catalysts based on iron and cobalt,”Chem. Comm., p. 849-850 (1998).
M. Enders et al., “8-Quinolylcyclopentadienyl, a Ligand with a Tailored Fit for Chelate Complexes,”Chem. Ber., vol. 129, p. 459-463 (1996).
P. Jutzi et al., “Cyclopentadienyl compounds wiht nitrogen donors in the side-chain,”Journal of Organometallic Chemistry, vol. 500, p. 175-185 (1995).

Affiliated with

Also associated with

Rating

Preparation of polyolefins having high molecular weights in... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Preparation of polyolefins having high molecular weights in..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Preparation of polyolefins having high molecular weights in... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-4243944