The present invention deals with a process for polymerising olefins in a solution and withdrawing a stream of the solution from the polymerisation reactor and passing it to a sequence of heating steps. The heated solution is passed to a separation step, which is conducted at a pressure of no more than 15 bar and in which separation step a liquid phase comprising the polymer and a vapour phase coexist. A vapour stream and a concentrated solution stream comprising the polymer are withdrawn from the separation step. At least a part of the vapour stream is passed to the first polymerisation reactor, to the second polymerisation reactor or to both.

The present invention deals with a process for polymerising olefins in a solution and withdrawing a stream of the solution from the polymerisation reactor and passing it to a sequence of heating steps. The heated solution is passed to a separation step, which is conducted at a pressure of no more than 15 bar and in which separation step a liquid phase comprising the polymer and a vapour phase coexist. A vapour stream and a concentrated solution stream comprising the polymer are withdrawn from the separation step. At least a part of the vapour stream is passed to the first polymerisation reactor, to the second polymerisation reactor or to both.

The present invention deals with a process for polymerising olefins in a solution and withdrawing a stream of the solution from the polymerisation reactor and passing it to a sequence of heating steps. The heated solution is passed to a separation step, which is conducted at a pressure of no more than 15 bar and in which separation step a liquid phase comprising the polymer and a vapour phase coexist. A vapour stream and a concentrated solution stream comprising the polymer are withdrawn from the separation step. At least a part of the vapour stream is passed to the first polymerisation reactor, to the second polymerisation reactor or to both.

The present invention is concerned with a screening assembly comprising a separating device connected to a conduit for an effluent stream comprising a polymer and a mixture of hydrocarbons, wherein the separating device is configured to separate the effluent stream into a polymer-rich stream and a polymer-lean vapor stream, wherein the first separation device comprises an inlet, a first outlet for withdrawing a polymer-rich stream, and a second outlet for withdrawing a polymer-lean vapor stream, a screening device connected to the separating device via a conduit for the polymer-lean vapor stream, wherein the screening device comprises a first inlet connected to the conduit for the polymer-lean vapor stream, a first outlet for withdrawing a cleaned vapor stream, a second outlet for withdrawing a polymer-comprising condensed vapor stream, and at least one second inlet for introducing a condensed vapor stream.

The present invention is concerned with a screening assembly comprising a separating device connected to a conduit for an effluent stream comprising a polymer and a mixture of hydrocarbons, wherein the separating device is configured to separate the effluent stream into a polymer-rich stream and a polymer-lean vapor stream, wherein the first separation device comprises an inlet, a first outlet for withdrawing a polymer-rich stream, and a second outlet for withdrawing a polymer-lean vapor stream, a screening device connected to the separating device via a conduit for the polymer-lean vapor stream, wherein the screening device comprises a first inlet connected to the conduit for the polymer-lean vapor stream, a first outlet for withdrawing a cleaned vapor stream, a second outlet for withdrawing a polymer-comprising condensed vapor stream, and at least one second inlet for introducing a condensed vapor stream.

A method of separating a polyisoolefin elastomer from non-polymeric components in an organic solvent involves ultrafiltration of a solution of the polyisoolefin elastomer and non-polymeric components in an organic solvent through a semipermeable membrane to substantially retain the polyisoolefin elastomer in a retentate and provide the non-polymeric components in a permeate. Advantageously, stabilizers for the polyisoolefin elastomer are retained in the retentate along with the polyisoolefin elastomer, permeate flux through the membrane is higher as concentration of the polyisoolefin elastomer in the solution increases up to a concentration limit, the separated polyisoolefin elastomer in the retentate has a molecular weight that can be substantially unchanged even when ultrafiltration is conducted at elevated temperature and the amount of polyisoolefin elastomer in the permeate is unmeasurable providing an oligomer-rich permeate uncontaminated by polyisoolefin elastomer. A process for curing a polyisoolefin copolymer involves reducing content of an oligomer to 900 ppm or less in a mixture of the oligomer and the polyisoolefin copolymer to produce an oligomer-depleted mixture, and adding a resin cure system to the oligomer-depleted mixture to cure the polyisoolefin copolymer.

A method of separating a polyisoolefin elastomer from non-polymeric components in an organic solvent involves ultrafiltration of a solution of the polyisoolefin elastomer and non-polymeric components in an organic solvent through a semipermeable membrane to substantially retain the polyisoolefin elastomer in a retentate and provide the non-polymeric components in a permeate. Advantageously, stabilizers for the polyisoolefin elastomer are retained in the retentate along with the polyisoolefin elastomer, permeate flux through the membrane is higher as concentration of the polyisoolefin elastomer in the solution increases up to a concentration limit, the separated polyisoolefin elastomer in the retentate has a molecular weight that can be substantially unchanged even when ultrafiltration is conducted at elevated temperature and the amount of polyisoolefin elastomer in the permeate is unmeasurable providing an oligomer-rich permeate uncontaminated by polyisoolefin elastomer. A process for curing a polyisoolefin copolymer involves reducing content of an oligomer to 900 ppm or less in a mixture of the oligomer and the polyisoolefin copolymer to produce an oligomer-depleted mixture, and adding a resin cure system to the oligomer-depleted mixture to cure the polyisoolefin copolymer.

A method of separating a polyisoolefin elastomer from non-polymeric components in an organic solvent involves ultrafiltration of a solution of the polyisoolefin elastomer and non-polymeric components in an organic solvent through a semipermeable membrane to substantially retain the polyisoolefin elastomer in a retentate and provide the non-polymeric components in a permeate. Advantageously, stabilizers for the polyisoolefin elastomer are retained in the retentate along with the polyisoolefin elastomer, permeate flux through the membrane is higher as concentration of the polyisoolefin elastomer in the solution increases up to a concentration limit, the separated polyisoolefin elastomer in the retentate has a molecular weight that can be substantially unchanged even when ultrafiltration is conducted at elevated temperature and the amount of polyisoolefin elastomer in the permeate is unmeasurable providing an oligomer-rich permeate uncontaminated by polyisoolefin elastomer. A process for curing a polyisoolefin copolymer involves reducing content of an oligomer to 900 ppm or less in a mixture of the oligomer and the polyisoolefin copolymer to produce an oligomer-depleted mixture, and adding a resin cure system to the oligomer-depleted mixture to cure the polyisoolefin copolymer.

A process for producing a polymer composition comprising the steps (A) to (M) as recited herein, involving the polymerization, in a polymerization reactor of a first polymer, a first stream thereof being passed into a first separator wherein a first liquid phase comprising the polymer and a first vapor phase coexist; withdrawing a first vapor stream and a first concentrated solution stream comprising the polymer from the first separator, passing at least a part of the first vapor stream to a first fractionator; withdrawing a first overhead stream and a first bottom stream from the first fractionator; recovering at least a part of the first overhead stream as a first recycle stream and passing it to the polymerization reactor; passing the first concentrated solution stream from the first separator to a second separator, wherein a second liquid phase comprising the polymer and a second vapor phase coexist; passing at least a part of the second vapor stream to a second fractionator; withdrawing a second overhead stream and a second bottom stream from the second fractionator; recovering at least a part of the second overhead stream as a second recycle stream and passing it to the polymerization reactor; wherein the mass flow rate of the first recycle stream is at least 80% of the mass flow rate of the first vapor stream and the mass flow rate of the second recycle stream is at least 70% of the mass flow rate of the second vapor stream.

A process for producing a polymer composition comprising the steps (A) to (M) as recited herein, involving the polymerization, in a polymerization reactor of a first polymer, a first stream thereof being passed into a first separator wherein a first liquid phase comprising the polymer and a first vapor phase coexist; withdrawing a first vapor stream and a first concentrated solution stream comprising the polymer from the first separator, passing at least a part of the first vapor stream to a first fractionator; withdrawing a first overhead stream and a first bottom stream from the first fractionator; recovering at least a part of the first overhead stream as a first recycle stream and passing it to the polymerization reactor; passing the first concentrated solution stream from the first separator to a second separator, wherein a second liquid phase comprising the polymer and a second vapor phase coexist; passing at least a part of the second vapor stream to a second fractionator; withdrawing a second overhead stream and a second bottom stream from the second fractionator; recovering at least a part of the second overhead stream as a second recycle stream and passing it to the polymerization reactor; wherein the mass flow rate of the first recycle stream is at least 80% of the mass flow rate of the first vapor stream and the mass flow rate of the second recycle stream is at least 70% of the mass flow rate of the second vapor stream.