Production of propylene block copolymer

Claim 2

A process for producing a propylene-ethylene block copolymer in the presence of a stereospecific catalyst by use of two or more polymerization vessels connected together in series, which comprises (i) polymerizing propylene alone or propylene and ethylene at an ethylene/propylene reaction ratio lower than 6/94 by weight and then (ii) polymerizing ethylene and propylene at an ethylene/propylene reaction ratio of 15/85 to 95/5 by weight, wherein the polymerization reaction is carried out in bulk with substantially no inert medium, wherein polymerization step (i) is conducted continuously to obtain 60 to 95% by weight of the desired polymer based on the total polymer and polymerization step (ii) is conducted batch-wise to obtain 40 to 5% by weight of the desired polymer based on the total polymer, wherein the continuous polymerization of step (i) is conducted in vessels in series except for the last vessel, said last vessel consisting of two or more vessels connected in parallel and wherein the batch-wise polymerization of step (ii) is conducted alternately in said vessels connected in parallel, wherein when the polymer slurry is transferred from the polymerization vessels for continuous polymerization to the polymerization vessels for batch-wise polymerization, a catalyst deactivator is added to the slurry so that the catalyst activity is decreased to less than 2/3 of that which would be when said catalyst deactivator is not added, and after completion of polymerization in the batch-wise polymerization vessels, a catalyst deactivator is added so that the catalyst activity is decreased to less than 1/2 of that which would be when said deactivator is not added.

Claim 3

A process for producing a propylene-ethylene block copolymer in the presence of a stereospecific catalyst by use of two or more polymerization vessels connected together in series, which comprises (i) polymerizing propylene alone or propylene and ethylene at an ethylene/propylene reaction ratio lower than 6/94 by weight and then (ii) polymerizing ethylene and propylene at an ethylene/propylene reaction ratio of 15/85 to 95/5 by weight, wherein the polymerization reaction is carried out in bulk with substantially no inert medium, wherein polymerization step (i) is conducted continuously to obtain 60 to 95% by weight of the desired polymer based on the total polymer and polymerization step (ii) is conducted batch-wise to obtain 40 to 5% by weight of the desired polymer based on the total polymer, wherein the continuous polymerization of step (i) is conducted in vessels in series except for the last vessel, said last vessel consisting of two or more vessels connected in parallel and wherein the batch-wise polymerization of step (ii) is conducted alternately in said vessels connected in parallel, wherein when the polymer slurry is transferred from the polymerization vessels for continuous polymerization to the polymerization vessels for batch-wise polymerization, a catalyst deactivator is added to the slurry so that the catalyst activity is decreased to less than 2/3 of that which would be when said catalyst deactivator is not added, and after completion of polymerization in the batch-wise polymerization vessels, the catalyst is deactivated within less than 1/3 of the time prescribed for polymerization in the batch-wise polymerization vessels.

Claim 4

A process for producing a propylene-ethylene block copolymer in the presence of a stereospecific catalyst by use of two or more polymerization vessels connected together in series, which comprises (i) polymerizing propylene alone or propylene and ethylene at an ethylene/propylene reaction ratio lower than 6/94 by weight and then (ii) polymerizing ethylene and propylene at an ethylene/propylene reaction ratio of 15/85 to 95/5 by weight, wherein the polymerization reaction is carried out in bulk with substantially no inert medium, wherein polymerization step (i) is conducted continuously to obtain 60 to 95% by weight of the desired polymer based on the total polymer and polymerization step (ii) is conducted batch-wise to obtain 40 to 5% by weight of the desired polymer based on the total polymer, wherein the continuous polymerization of step (i) is conducted in vessels in series except for the last vessel, said last vessel consisting of two or more vessels connected in parallel and wherein the batch-wise polymerization of step (ii) is conducted alternately in said vessels connected in parallel, wherein when the polymer slurry is transferred from the polymerization vessels for continuous polymerization to the polymerization vessels for batch-wise polymerization, a catalyst deactivator is added to the slurry so that the catalyst activity is decreased to less than 2/3 of that which would be when said catalyst deactivator is not added, and after completion of polymerization in the batch-wise polymerization vessels, the catalyst is deactivated within less than 1/3 of the time prescribed for polymerization in the batch-wise polymerization vessels.

Claim 5

A process for producing a propylene-ethylene block copolymer in the presence of a stereospecific catalyst by use of two or more polymerization vessels connected together in series, which comprises (i) polymerizing propylene alone or propylene and ethylene at an ethylene/propylene reaction ratio lower than 6/94 by weight and then (ii) polymerizing ethylene and propylene at an ethylene/propylene reaction ratio of 15/85 to 95/5 by weight, wherein the polymerization reaction is carried out in bulk with substantially no inert medium, wherein polymerization step (i) is conducted continuously to obtain 60 to 95% by weight of the desired polymer based on the total polymer and polymerization step (ii) is conducted batch-wise to obtain 40 to 5% by weight of the desired polymer based on the total polymer, wherein the continuous polymerization of step (i) is conducted in vessels in series except for the last vessel, said last vessel consisting of two or more vessels connected in parallel and wherein the batch-wise polymerization of step (ii) is conducted alternately in said vessels connected in parallel, wherein when the polymer slurry is transferred from the polymerization vessels for continuous polymerization to the polymerization vessels for batch-wise polymerization, a catalyst deactivator is added to the slurry so that the catalyst activity is decreased to less than 1/4 of that which would be when said catalyst deactivator is not added, and after the transfer of the slurry is complete, an organoaluminum compound is added so that the catalyst activity is increased to more than 1.1 times then that which would be before said catalyst activator is added, and on completion of the batch-wise polymerization, a catalyst deactivator is added so that the catalyst activity is decreased to less than 1/2 of that which would be when said deactivator is not added.

Claim 6

A process for producing a propylene-ethylene block copolymer in the presence of a stereospecific catalyst by use of two or more polymerization vessels connected together in series, which comprises (i) polymerizing propylene alone or propylene and ethylene at an ethylene/propylene reaction ratio lower than 6/94 by weight and then (ii) polymerizing ethylene and propylene at an ethylene/propylene reaction ratio of 15/85 to 95/5 by weight, wherein the polymerization reaction is carried out in bulk with substantially no inert medium, wherein polymerization step (i) is conducted continuously to obtain 60 to 95% by weight of the desired polymer based on the total polymer and polymerization step (ii) is conducted batch-wise to obtain 40 to 5% by weight of the desired polymer based on the total polymer, wherein the continuous polymerization of step (i) is conducted in vessels in series except for the last vessel, said last vessel consisting of two or more vessels connected in parallel and wherein the batch-wise polymerization of step (ii) is conducted alternately in said vessels connected in parallel, wherein when the polymer slurry is transferred from the polymerization vessels for continuous polymerization to the polymerization vessels for batch-wise polymerization, a catalyst deactivator is added to the slurry so that the catalyst activity is decreased to less than 1/4 of that which would be when said catalyst deactivator is not added, and after the transfer of the slurry is complete, an organoaluminum compound is added so that the catalyst activity is increased to more than 1.1 times then that which would be before said catalyst activator is added, and on completion of the batch-wise polymerization, a catalyst deactivator is added so that the catalyst activity is decreased to less than 1/2 of that which would be when said deactivator is not added.

Claim 7

A process for producing a propylene-ethylene block copolymer in the presence of a stereospecific catalyst by use of two or more polymerization vessels connected together in series, which comprises (i) polymerizing propylene alone or propylene and ethylene at an ethylene/propylene reaction ratio lower than 6/94 by weight and then (ii) polymerizing ethylene and propylene at an ethylene/propylene reaction ratio of 15/85 to 95/5 by weight, wherein the polymerization reaction is carried out in bulk with substantially no inert medium, wherein polymerization step (i) is conducted continuously to obtain 60 to 95% by weight of the desired polymer based on the total polymer and polymerization step (ii) is conducted batch-wise to obtain 40 to 5% by weight of the desired polymer based on the total polymer, wherein the continuous polymerization of step (i) is conducted in vessels in series except for the last vessel, said last vessel consisting of two or more vessels connected in parallel and wherein the batch-wise polymerization of step (ii) is conducted alternately in said vessels connected in parallel, wherein when the polymer slurry is transferred from the polymerization vessels for continuous polymerization to the polymerization vessels for batch-wise polymerization, a catalyst deactivator is added to the slurry so that the catalyst activity is decreased to less than 1/4 of that which would be when said catalyst deactivator is not added, and after the transfer of the slurry is complete, an organoaluminum compound is added so that the catalyst activity is increased to more than 1.1 times then that which would be before said compound is added, and on completion of the batch-wise polymerization, a catalyst is deactivated within less than 1/3 of the time prescribed for polymerization in the batch-wise polymerization vessels.

Claim 8

A process for producing a propylene-ethylene block copolymer in the presence of a stereospecific catalyst by use of two or more polymerization vessels connected together in series, which comprises (i) polymerizing propylene alone or propylene and ethylene at an ethylene/propylene reaction ratio lower than 6/94 by weight and then (ii) polymerizing ethylene and propylene at an ethylene/propylene reaction ratio of 15/85 to 95/5 by weight, wherein the polymerization reaction is carried out in bulk with substantially no inert medium, wherein polymerization step (i) is conducted continuously to obtain 60 to 95% by weight of the desired polymer based on the total polymer and polymerization step (ii) is conducted batch-wise to obtain 40 to 5% by weight of the desired polymer based on the total polymer, wherein the continuous polymerization of step (i) is conducted in vessels in series except for the last vessel, said last vessel consisting of two or more vessels connected in parallel and wherein the batch-wise polymerization of step (ii) is conducted alternately in said vessels connected in parallel, wherein when the polymer slurry is transferred from the polymerization vessels for continuous polymerization to the polymerization vessels for batch-wise polymerization, a catalyst deactivator is added to the slurry so that the catalyst activity is decreased to less than 1/4 of that which would be when said catalyst deactivator is not added, and after the transfer of the slurry is complete, an organoaluminum compound is added so that the catalyst activity is increased to more than 1.1 times then that which would be before said compound is added, and on completion of the batch-wise polymerization, a catalyst is deactivated within less than 1/3 of the time prescribed for polymerization in the batch-wise polymerization vessels.

Claim 9

The process as claimed in claim 1, wherein polymerization step (i) is carried out at 60° to 85° C. and polymerization step (ii) is carried out at 30° to 65° C.

Claim 10

The process as claimed in claim 2, wherein polymerization step (i) is carried out at 60° to 85° C. and polymerization step (ii) is carried out at 30° to 65° C.

Claim 11

The process as claimed in claim 3, wherein polymerization step (i) is carried out at 60° to 85° C. and polymerization step (ii) is carried out at 30° to 65° C.

Claim 12

The process as claimed in claim 4, wherein polymerization step (i) is carried out at 60° to 85° C. and polymerization step (ii) is carried out at 30° to 65° C.

Claim 13

The process as claimed in claim 1, wherein the stereospecific catalyst consists of (i) a solid catalyst containing at least three elements of Mg, Ti, and Cl, and (ii) an organoaluminum compound, and the yield of the polymer per unit weight of said solid catalyst is greater than 4000 g/g-solid catalyst.

Claim 14

The process as claimed in claim 2, wherein the stereospecific catalyst consists of (i) a solid catalyst containing at least three elements of Mg, Ti, and Cl, and (ii) an organoaluminum compound, and the yield of the polymer per unit weight of said solid catalyst is greater than 4000 g/g-solid catalyst.

Claim 15

The process as claimed in claim 3, wherein the stereospecific catalyst consists of (i) a solid catalyst containing at least three elements of Mg, Ti, and Cl, and (ii) an organoaluminum compound, and the yield of the polymer per unit weight of said solid catalyst is greater than 4000 g/g-solid catalyst.

Claim 16

The process as claimed in claim 4, wherein the stereospecific catalyst consists of (i) a solid catalyst containing at least three elements of Mg, Ti, and Cl, and (ii) an organoaluminum compound, and the yield of the polymer per unit weight of said solid catalyst is greater than 4000 g/g-solid catalyst.