A composition of matter comprising vinyl ended copolymer chains having a number average molecular weight (M.sub.n) of about 1500 to 75,000, the number average molecular weight being determined by gel permeation chromatography (GPC) at 145.degree. C., a ratio of vinyl groups to total olefin groups according to the formula ##EQU1## where a and b have the following sets of valuer: when a=-0.24, b=0.8; when a=-0.20, b=0.8; when a=-0.18, b=0.83; when a=-0.15, b=0.83; and when a=-0.10, b=0.85; and where the total number of vinyl groups per 1000 carbon atoms is in the range from greater than 0.13 to less than 9.85, the vinyl group measurement being taken by GPC (145.degree. C.) and .sup.1 H-NMR (125.degree. C.).
This application is a continuation of application Ser. No. 09/020,138, filed Feb. 6, 1998 now abandoned, and claims the benefit under 35 U.S.C. 119(e) of provisional application, Ser. No. 60/037,323, filed Feb. 7, 1997.
The present invention provides a novel olefin polymerization catalyst having excellent olefin polymerization activity and, in polymerization with the catalyst comprising a transition metal compound, a polymerization process for preparing a polymer having a low molecular weight with high polymerization activity. The process comprises polymerizing olefin in the presence of an olefin polymerization catalyst comprising (A) a transition metal compound represented by the following ##STR00001## [M: a Group 4 or 5 transition metal atom in the Periodic Table, m: 1 4, R.sup.1: H, a C.sub.1 C.sub.5 linear hydrocarbon group, 3- to 5-membered alicyclic hydrocarbon group, bicycloaliphatic hydrocarbon group wherein two alicyclic rings share one or more carbon atoms, R.sup.2 to R.sup.6: H, a halogen atom, hydrocarbon group etc, X: H, a halogen atom etc, and n is a valence of M], and (B) at least one compound selected from (B-1) an organometallic compound, (B-2) an organoaluminum oxy compound and (B-3) an ionizing ionic compound.
The present invention relates to a polymer having a melt tension (MT (g)) substantially the same as or lower than that of a conventional polymer which is substantially the same as the polymer in the recurring unit of the main skeleton, the molecular weight, the molecular weight distribution and the crystallinity, and having a flow activation energy (Ea (KJ/mol)) larger than a value obtained by adding 5 KJ/mol to the Ea value of the conventional polymer. A preferred example of the polymer is a branched polyolefin comprising 50 to 100% by mol of recurring units derived from ethylene and 0 to 50% by mol of recurring units derived from an .alpha.-olefin of 3 to 20 carbon atoms and having the following properties: the flow activation energy (Ea (KJ/mol)) and the .alpha.-olefin content (C (% by weight)) satisfy a specific relation, and the melt tension (MT (g)) and the melt flow rate (MFR (g/10 min)) satisfy a specific relation. This branched polyolefin is excellent in moldability and mechanical strength.
An ethylene copolymer is provided which is a copolymer of ethylene and an .alpha.-olefin of 3 to 20 carbon atoms and has the following properties: (a) the melt index (MI2) at 190.degree. C. under a load of 2.16 kg is in the range of 0.0001 to 1000 g/10 min, (b) the density is not more than 0.899 g/cm.sup.3, (c) the relationship between a vinyl group amount and MI2 of the polymer satisfies the following expression: and (d) the relationship between a vinylidene group amount and MI2 of the polymer satisfies the following expression:
