A magnesium-based solid, by means of determination based on a nitrogen adsorption method, has a multimodal pore distribution and a specific surface area of not less than 50 m.sup.2/g, and the pore size distribution of the solid is in a range of 1 nm to 300 nm. There is at least one peak within a pore size range of less than 10 nm, and there is at least another peak within a pore size range of not less than 10 nm. A catalyst is formed using the solid catalyst component is used for propylene polymerization.

A magnesium-based solid, by means of determination based on a nitrogen adsorption method, has a multimodal pore distribution and a specific surface area of not less than 50 m.sup.2/g, and the pore size distribution of the solid is in a range of 1 nm to 300 nm. There is at least one peak within a pore size range of less than 10 nm, and there is at least another peak within a pore size range of not less than 10 nm. A catalyst is formed using the solid catalyst component is used for propylene polymerization.

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.)

Provided are a novel transition metal compound of the following Chemical Formula 1 that exhibits excellent catalytic activity, allows formation of a macromonomer which is a polymer in which a double bond is formed at the end of a chain, and improves a melt strength characteristic when used in polymerizing polypropylene, and a method of preparing a polypropylene using the same.

##STR00001##

wherein A, M, R.sub.1 to R.sub.10, X.sub.1 and X.sub.2, Y.sub.1 and Y.sub.2 and m are described herein.

Provided are a novel transition metal compound of the following Chemical Formula 1 that exhibits excellent catalytic activity, allows formation of a macromonomer which is a polymer in which a double bond is formed at the end of a chain, and improves a melt strength characteristic when used in polymerizing polypropylene, and a method of preparing a polypropylene using the same.

##STR00001##

wherein A, M, R.sub.1 to R.sub.10, X.sub.1 and X.sub.2, Y.sub.1 and Y.sub.2 and m are described herein.

Polymerizable compositions are described which contain, as photoinitiator, at least one acyltin compound according to the general formula (I): ##STR00001##

Polymerizable compositions are described which contain, as photoinitiator, at least one acyltin compound according to the general formula (I): ##STR00001##

A method of making functional polyisobutylene (PIB)-containing oligomers and polymers. By the disclosed method, the synthesis of functional PIB-containing polymers can be achieved directly under cationic polymerization conditions and does not include any post-polymerization reactions. The desired functionality is introduced by direct Electrophilic Aromatic Substitution (EAS) reaction using substituted phenyl ring carrying desirable functionalities that do not react with Lewis acid but have weak association with Lewis acid, which still allow living polymerization and EAS reaction under living cationic polymerization conditions. In the disclosed method functional polyisobutylene or isobutylene containing oligomers and polymers can be prepared using stoichiometric or near stoichiometric ratios of the capping or functionalization reagent to polymer end-chain.

A method of making functional polyisobutylene (PIB)-containing oligomers and polymers. By the disclosed method, the synthesis of functional PIB-containing polymers can be achieved directly under cationic polymerization conditions and does not include any post-polymerization reactions. The desired functionality is introduced by direct Electrophilic Aromatic Substitution (EAS) reaction using substituted phenyl ring carrying desirable functionalities that do not react with Lewis acid but have weak association with Lewis acid, which still allow living polymerization and EAS reaction under living cationic polymerization conditions. In the disclosed method functional polyisobutylene or isobutylene containing oligomers and polymers can be prepared using stoichiometric or near stoichiometric ratios of the capping or functionalization reagent to polymer end-chain.