TH33571A - Olefin polymerization process - Google Patents

Abstract

The invention DC60 involves a process for the production of indexed polymers olefins. Low Polydispur City In solution polymerization that acts With a charged catalyst Positive in the reactor Contains the boiling liquid hydrocarbon cycle And vapor gaps above the said cycle. Polymerization Non-mechanical substances that can eliminate the formation of bubbles during the Polymerization The substances used may be chosen from a) liquid hydrocarbon aerosols that enter the vapor gap. B) new liquid olefins fed at lower temperatures than the liquid cycle and c) foaming agents such as polyoxymethylchylene glycol or silicone (Fig. 6 The invention involves the production of indexed olefin polymers. Low Polydispur City In solution polymerization that acts With a charged catalyst Positive in the reactor Contains the boiling liquid hydrocarbon cycle And vapor gaps above the said cycle. Polymerization Non-mechanical substances that can eliminate the formation of bubbles during the Polymerization The substances used may be chosen from a) liquid hydrocarbon aerosols that enter the vapor gap. Of to the reactor; b) new liquid olefins fed at temperatures below the liquid cycle and c) foaming agents such as polyoxymethylkylene, glycol or silicone (Fig. 6)

Claims (21)

1. A process for producing low polydispercity olefin polymers with low residual catalysts and/or low chlorine content, involving the polymerization of olefins in solution with a cationic catalyst in a reactor containing a liquid phase composed of boiling liquid hydrocarbons as the polymerization medium, with a vapor gap above the liquid phase. This method is characterized by the use of non-mechanical agents to eliminate foam formation during polymerization. 2. A process for reducing the polydispercity index of olefin polymers with low residual and/or low chlorine content catalysts during olefin solution polymerization. This is achieved using a cationic catalyst in a liquid phase reactor containing boiling liquid hydrocarbons as the polymerization medium, with a vapor gap above the liquid phase. A unique characteristic of this process is that polymerization is carried out using non-mechanical agents that eliminate foam formation during the polymerization process. 3. The process under claim 1 or 2, which is characterized by the substance capable of eliminating foam formation being a liquid hydrocarbon aerosol introduced into the vapor gap above the liquid phase in the reactor. 4. The process under claim 3 is characterized by the liquid hydrocarbon aerosol being introduced into a vapor gap at a height of at least 1 meter above the surface of the liquid phase separating the vapor gap from the liquid phase. 5. The process under claim 3 or 4, characterized by the introduction of liquid hydrocarbon aerosols into the lower-temperature vapor gap of the liquid phase in the reactor vessel. 6. Any process under claims 3 through 5, which is characterized by the liquid hydrocarbon aerosol containing one or all of the fresh liquid olefins fed into the reactor. 7. Any of the processes under claims 3 through 6, which are characterized by the fact that the liquid hydrocarbon aerosol consists of wholly or partly of the liquid obtained after cooling and condensation of the condensed gases that escape from the vapor gap of the reactor. 8. Any process under claims 3 through 7 which is characterized by the liquid hydrocarbon aerosol consisting of a proportion of the liquid phase released from the reactor. 9. Any one of the processes under claims 3 through 8, which is characterized by the continuous polymerization of the olefin material and the continuous introduction of liquid hydrocarbon aerosols into the vapor gap of the reactor. 10. The process under claim 1 or 2 is characterized by the fact that the substance capable of eliminating foam formation is a fresh liquid olefin fed into the reactor at a temperature lower than that of the liquid phase. 11. The process under claim 10 is characterized by the temperature of the fresh liquid olefin fed being 2 to 30°C lower than that of the liquid phase in the reactor. 12. The process under claim 10 or 11, which is characterized by the introduction of a fresh liquid olefin into the liquid phase of the reactor. 13. The process under claim 10 or 11, which is characterized by the introduction of a fresh liquid olefin into the vapor gap of the reactor vessel. 14. Any of the processes under claims 10 through 13 are characterized by the continuous polymerization of the olefin material and the continuous introduction of fresh liquid olefin material into the reactor. 15. The process under claim 1 or 2, which is characterized by the substance capable of eliminating foam formation, being an antifoaming chemical. 16. The process under claim 15 is characterized by the selection of a selective defoaming agent from a group consisting of polyoxyalkylene glycol and silicone. 17. The process under claim 16 is characterized by the silicone having a kinematic viscosity at 25°C ranging from 5 to 1,000,000 centistokes. 18. The process pursuant to claim 16 is characterized by the polyoxyalkylene glycol being a block polyoxyalkylene glycol composed of ethylene oxide-based block units and propylene oxide-based block units. 19. Any of the processes under claims 16 through 18, which are characterized by the presence of a defoaming chemical in the reactor liquid phase at a concentration of 0.01 to 100 parts by weight per million relative to the liquid phase. 20. Any of the processes under claims 16 through 19 are characterized by the continuous polymerization of the olefin material and the continuous introduction of the defoaming chemical into the reactor. 21. Any of the processes under Reservations 1 through 20 are characterized by the use of at least one C4 olefin for polymerization, namely isobutene.