Patent application number | Description | Published |
20090156758 | Gas-Phase Process for the Poymerization of Olefins - A process for the gas-phase polymerization of one or more alpha-olefins in the presence of a polymerization catalyst system, the process comprising: a) contacting in a continuous way a gas comprising one or more of said alpha-olefins with said catalyst system in a gas-phase tubular reactor at a temperature from 30° C. to 130° C. in order to obtain a polymerization degree up to 500 grams per gram of catalyst system; b) feeding in continuous the prepolymer from step a) to a successive gas-phase polymerization reactor; wherein said gas-phase tubular reactor has a length/diameter ratio higher than 100. | 06-18-2009 |
20100317811 | PROCESS FOR THE GAS-PHASE POLYMERIZATION OF OLEFINS - A process for the gas-phase polymerization of α-olefins carried out in two interconnected polymerization zones, wherein the growing polymer particles flow through the first of said polymerization zones (riser) under fast fluidization conditions, leave said riser and enter the second of said polymerization zones (downcomer) through which they flow downward in a densified form, the process being characterized in that: (a) the gas mixture present in the riser is totally or partially prevented from entering the downcomer by introducing into the upper part of said downcomer a liquid stream LB having a composition different from the gaseous mixture present in the riser; (b) the ratio R between the flow rate F | 12-16-2010 |
20110054127 | PROCESS FOR THE GAS-PHASE POLYMERIZATION OF OLEFINS - A process for the polymerisation of olefins carried out in a gas-phase reactor having interconnected polymerization zones, where the growing polymer particles flow upward through a first polymerization zone (riser) under fast fluidization or transport conditions, leave said riser and enter a second polymerization zone (downcomer) through which they flow downward under the action of gravity, leave said downcomer and are reintroduced into the riser, a gas recycle stream being withdrawn from said first polymerisation zone, subjected to cooling below its dew point and then returned to said first polymerisation zone, the process being characterised in that said gas recycle stream is cooled at a temperature Tc ranging from 0.05° C. to 3° C. below its dew point. | 03-03-2011 |
20120172549 | Process for the Gas-Phase Polymerization of Olefins - A process for the gas-phase polymerization of one or more alpha-olefins in the presence of a polymerization catalyst, the process comprising:
| 07-05-2012 |
20120178881 | Propylene polymer compositions - A propylene polymer composition comprising (percent by weight):
| 07-12-2012 |
20120245314 | Process for the Production of Polyolefin Films - A process for the production of a corona-treated polyolefin film comprising the gas-phase polymerization of one or more α-olefins in the presence of a polymerization catalyst and an antistatic agent having a molecular weight higher than 500, said antistatic agent being fed at any stage of the polymerization process in an amount from 30 to 500 ppm weight based on the weight of the produced polyolefin | 09-27-2012 |
20130090436 | Process for the Gas-Phase Polymerization of Olefins - A process for the gas-phase copolymerization of: (a) propylene, (b) at least one C | 04-11-2013 |
20140121340 | POLYPROPYLENE FILMS AND SHEETS - Films or sheets of polypropylene, particularly biaxially oriented polypropylene (BOPP) films, exhibiting excellent physical and mechanical properties combined with good processing characteristics can be prepared from propylene polymers prepared in the presence of Ziegler-Natta catalysts comprising a succinate and a diether compound. | 05-01-2014 |
20140235802 | PROCESS FOR THE PREPARATION OF HIGH PURITY PROPYLENE POLYMERS - A process for the preparation of high purity propylene polymers carried out in the presence of a catalyst comprising the product obtained by contacting:
| 08-21-2014 |
20140316069 | PROCESS FOR THE PREPARATION OF HETEROPHASIC PROPYLENE POLYMER COMPOSITIONS - A process for the preparation of propylene polymer compositions comprising from 50 to 90% by weight of a propylene (co)polymer fraction insoluble in xylene at 25° C., and from 10 to 50% by weight of an ethylene copolymer fraction soluble in xylene at 25° C., said process comprising:
| 10-23-2014 |