Abstract: A process for producing a propylene random copolymer comprising the repeating units (I)-(III) in quantities of 70-99.9 molar % of (I), 0-15 molar % and 0.1-30 molar %, respectively, which comprises contacting monomers which afford the following repeating units: ##STR1## m denotes 0 or an integer of 2-10, R.sub..alpha., R.sub..beta. and R.sub..gamma. independently represent a hydrogen atom or a hydrocarbyl group having 1-5 carbon atoms, at least one of R.sub..beta. and R.sub..gamma. being the hydrocarbyl group, and n denotes an integer of 1-5, with a polymerization catalyst to copolymerize, the polymerization catalyst comprising:component (A) which is a transition metal compound represented by the formula:Q.sub.a (C.sub.5 H.sub.5-a-b R.sup.1.sub.b)(C.sub.5 H.sub.5-a-c R.sup.2.sub.c)MeXYwherein R.sup.1 and R.sup.

Abstract: Ziegler polymerization of .alpha.-olefins is disclosed which is characterized by a solid catalyst component. The solid catalyst component, Component (A), comprises Sub-component (i) which is a solid catalyst component for Ziegler catalysts comprising Ti, Mg and a halogen; Sub-component (ii) which is a silicon compound having a plurality of a bond represented by a formula: Si--OR.sup.1R.sup.1.sub.m X.sub.n Si(OR.sup.2).sub.4-n-mwherein R.sup.1 indicates a hydrocarbyl group of 1 to 8 carbon atoms, Sub-component (iii) which is a vinylsilane compound, and Sub-component (iii) which is an organometal compound of a metal of Groups I to IV of the Periodic Table. No need of an outside electron donor may be required, and the polymer produced is improved in its content of a "tacky" polymer.

Abstract: A process for the preparation of olefin polymers, which comprises polymerizing an olefin in the presence of a catalyst which comprises: (A) a solid catalyst component obtained by contacting a magnesium dihalide such as MgCl.sub.2 with a titanium tetra-alkoxide such as Ti(O-nBu).sub.4 and then with a polymeric silicon compound having a structure represented by the formula ##STR1## wherein R stands for a hydrocarbon residue such as CH.sub.3, and contacting the obtained solid component with a halogen compound of silicon such as SiCl.sub.4 or with a halogen compound of silicon such as SiCl.sub.4 and a halogen compound of titanium such as TiCl.sub.4, (B) an organoaluminum compound such as Al(Et).sub.3 ; and (C) an organic silicon compound having an Si--O--C linkage such as PhSi(OEt).sub.3. According to this process, a polymer having a high stereoregularity, a narrow particle size distribution and a high bulk density can be obtained in a high yield with a high efficiency.

Abstract: Disclosed is a titanium-containing solid catalyst component which is a contact reaction product of:(i) a magnesium halide such as MgCl.sub.2,(ii) a titanium compound represented by the formula:Ti(OR.sup.1).sub.a X.sub.4-awherein a is a number of 0.ltoreq.a.ltoreq.4, R.sup.1 represents a hydrocarbon residue having 1 to 20 carbon atoms, and X represents a halogen atom, such as Ti(O--nBu).sub.4, and(iii) a coordination titanium compound represented by the formula:R.sup.2.sub.m R.sup.3.sub.n TiX.sub.4-m-nwherein R.sup.2 represents a cyclopentadienyl group or a substituted cyclopentadienyl group, R.sup.3 represents a hydrogen atom, a hydroxyl group, a hydrocarbyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an amino group or a substituted amino group, X represents a halogen atom, and m is a number of 1.ltoreq.m.ltoreq.4 and n is a number of 0.ltoreq.n.ltoreq.3, with the proviso that the condition of 1.ltoreq.m+n.ltoreq.4 is satisfied, such as Cp.sub.2 TiCl.sub.2, i.e.

Abstract: Ziegler polymerization of .alpha.-olefins is disclosed which is characterized by a solid catalyst component used in the Ziegler-type catalyst. The solid catalyst component, Component (A), comprises Component (i) which is a solid catalyst component for a Ziegler-type catalyst comprising Ti, Mg and a halogen; Component (ii) a silicon compound of a formula:R.sup.1 R.sup.2.sub.3-n Si(OR.sup.3).sub.nwherein R.sup.1 -R.sup.3 are each hydrocarbyl group characterized by R.sup.1 which has a branched hydrocarbyl group;Component (iii) a halogen compound of W or Mo; and Component (iv) an organometal compound of a metal of Groups I to IV of the Periodic Table.

Abstract: A catalyst component for polymerization of .alpha.-olefins is produced by causing mutual contact of:(A) a magnesium halide containing solid;(B) an electron donating compound, having the structural site as represented by the formula show below in its molecule: ##STR1## and (C) a titanium halide. The catalyst thus produced has high polymerization activity and is capable of producing polymers having excellent stereoregularity.