Reactor for propylene polymerization and process for producing propylene polymer

A propylene polymerization reaction apparatus for producing a propylene-based polymer by a multi-stage continuous vapor phase polymerization method, comprising at least one horizontal reactor including inside a stirring element rotatable around a horizontal axis, and at least one continuous stirred tank reactor connected to said at least one horizontal reactor;

• and
• the at least one continuous stirred tank reactor is a reactor for performing removal of heat of polymerization by utilization of mainly sensible heat of recirculation gas.

A propylene polymerization reaction apparatus for producing a propylene-based polymer by a multi-stage continuous vapor phase polymerization method, comprising at least one horizontal reactor including inside a stirring element rotatable around a horizontal axis, and at least one continuous stirred tank reactor connected to said at least one horizontal reactor;

• and
• the at least one continuous stirred tank reactor is a fluidized bed reactor.

A production method of a propylene-based polymer, comprising performing multi-stage continuous vapor phase polymerization of propylene in the presence of a catalyst for olefin polymerization with the propylene polymerization reaction apparatus comprising at least one horizontal reactor including inside a stirring element rotatable around a horizontal axis, and at least one continuous stirred tank reactor connected to said at least one horizontal reactor, comprising:

• performing a first stage polymerization to produce a polymer component (A) having a content of a monomer unit, based on propylene, of 95% by weight or more, by homopolymerization of propylene, or copolymerization of propylene and an α-olefin (provided that propylene is excluded) in the at least one horizontal reactor, and subsequently performing a second stage polymerization to produce a copolymer component (B) having a content of a monomer unit, based on propylene, of 95 to 5% by weight, by copolymerization of propylene and an α-olefin (provided that propylene is excluded) in the at least one continuous stirred tank reactor,
• wherein melt flow rate of the polymer component (A) (MFR1) and melt flow rate of the copolymer component (B) (MFR2) satisfy a relation of 3≦log(MFR1/MFR2)≦7.

A production method of a propylene-based polymer, comprising performing multi-stage continuous vapor phase polymerization of propylene in the presence of a catalyst for olefin polymerization with the propylene polymerization reaction apparatus comprising at least one horizontal including inside a stirring element rotatable around a horizontal axis, and at least one continuous stirred tank reactor connected to said at least one horizontal reactor;

• and the at least one continuous stirred tank reactor comprises at least two continuous stirred tank reactors, comprising:
• performing a second stage polymerization to produce a copolymer component (B) having a content of a monomer unit, based on propylene, of 95 to 5% by weight, by copolymerization of propylene and an α-olefin (provided that propylene is excluded) in the at least two continuous stirred tank reactors,
• wherein the copolymer components produced in each of the at least two continuous stirred tank reactors differ in content of the α-olefin and/or molecular weight.