To produce an olefin-based polymer having a minor amount of decrease in bulk density due to heat.

A solid catalyst component for olefin polymerization containing a titanium atom, a magnesium atom, a halogen atom, and as internal electron donor, and having an envelope E1 calculated by the following Formula (1) in a range of 0.810 to 0.920.

E1=LE1/LS1   (1)

(In Formula, LE1 is a convex hull perimeter of the solid catalyst component for olefin polymerization obtained from an image of the solid catalyst component for olefin polymerization captured with a scanning electron microscope, and LS1 is an actual perimeter of the solid catalyst component for olefin. polymerization obtained from the image of the solid catalyst component for olefin polymerization captured with the scanning electron microscope.)

To produce an olefin-based polymer having a minor amount of decrease in bulk density due to heat.

A solid catalyst component for olefin polymerization containing a titanium atom, a magnesium atom, a halogen atom, and as internal electron donor, and having an envelope E1 calculated by the following Formula (1) in a range of 0.810 to 0.920.

E1=LE1/LS1   (1)

(In Formula, LE1 is a convex hull perimeter of the solid catalyst component for olefin polymerization obtained from an image of the solid catalyst component for olefin polymerization captured with a scanning electron microscope, and LS1 is an actual perimeter of the solid catalyst component for olefin. polymerization obtained from the image of the solid catalyst component for olefin polymerization captured with the scanning electron microscope.)

A process for anionically polymerizing a (meth)acrylic acid in the presence of a tertiary organoaluminum compound (A), an organolithium compound (B) and at least one kind of a Lewis base (C) in a polymerization system. The tertiary organoaluminum compound (A) includes a tertiary organoaluminum compound (A1) having a chemical structure in which at least two of three unshared electrons of an aluminum atom are bonded to an aromatic ring via an oxygen atom, and the tertiary organoaluminum compound (A) has a molar ratio (A2)/(A1) in the range of 0% or above and 0.8% or below between a tertiary organoaluminum compound (A2) having a chemical structure in which at most one of three unshared electrons of an aluminum atom is bonded to an aromatic ring via an oxygen atom, and the tertiary organoaluminum compound (A1).

A process for anionically polymerizing a (meth)acrylic acid in the presence of a tertiary organoaluminum compound (A), an organolithium compound (B) and at least one kind of a Lewis base (C) in a polymerization system. The tertiary organoaluminum compound (A) includes a tertiary organoaluminum compound (A1) having a chemical structure in which at least two of three unshared electrons of an aluminum atom are bonded to an aromatic ring via an oxygen atom, and the tertiary organoaluminum compound (A) has a molar ratio (A2)/(A1) in the range of 0% or above and 0.8% or below between a tertiary organoaluminum compound (A2) having a chemical structure in which at most one of three unshared electrons of an aluminum atom is bonded to an aromatic ring via an oxygen atom, and the tertiary organoaluminum compound (A1).

Continuous preparation of polyisobutylene having a content of terminal double bonds of more than 50% by polymerizing isobutene in the presence of a polymerization catalyst customary therefor, by combining a technical 1-butene-, 2-butene- and isobutene-containing C.sub.4 hydrocarbon stream together with a stream of pure isobutene and feeding them into the reaction zone in such a way that the steady-state concentration of the isobutene in the combined stream at the feed point of the combined stream into the reaction zone has an average value of at least 40% by weight, and a polymerization plant therefor.

Continuous preparation of polyisobutylene having a content of terminal double bonds of more than 50% by polymerizing isobutene in the presence of a polymerization catalyst customary therefor, by combining a technical 1-butene-, 2-butene- and isobutene-containing C.sub.4 hydrocarbon stream together with a stream of pure isobutene and feeding them into the reaction zone in such a way that the steady-state concentration of the isobutene in the combined stream at the feed point of the combined stream into the reaction zone has an average value of at least 40% by weight, and a polymerization plant therefor.

To produce an olefin-based polymer having a minor amount of decrease in bulk density due to heat. A solid catalyst component for olefin polymerization containing a titanium atom, a magnesium atom, a halogen atom, and as internal electron donor, and having an envelope E1 calculated by the following Formula (1) in a range of 0.810 to 0.920.
E1=LE1/LS1  (1) (In Formula, LE1 is a convex hull perimeter of the solid catalyst component for olefin polymerization obtained from an image of the solid catalyst component for olefin polymerization captured with a scanning electron microscope, and LS1 is an actual perimeter of the solid catalyst component for olefin polymerization obtained from the image of the solid catalyst component for olefin polymerization captured with the scanning electron microscope.)

To produce an olefin-based polymer having a minor amount of decrease in bulk density due to heat. A solid catalyst component for olefin polymerization containing a titanium atom, a magnesium atom, a halogen atom, and as internal electron donor, and having an envelope E1 calculated by the following Formula (1) in a range of 0.810 to 0.920.
E1=LE1/LS1  (1) (In Formula, LE1 is a convex hull perimeter of the solid catalyst component for olefin polymerization obtained from an image of the solid catalyst component for olefin polymerization captured with a scanning electron microscope, and LS1 is an actual perimeter of the solid catalyst component for olefin polymerization obtained from the image of the solid catalyst component for olefin polymerization captured with the scanning electron microscope.)

The present invention relates to a novel process for preparing high-reactivity isobutene homo- or copolymers with a content of terminal vinylidene double bonds per polyisobutene chain end of at least 70 mol %. The present invention further relates to novel isobutene polymers.

The present invention relates to a novel process for preparing high-reactivity isobutene homo- or copolymers with a content of terminal vinylidene double bonds per polyisobutene chain end of at least 70 mol %. The present invention further relates to novel isobutene polymers.