The metallocene compound represented by the following general formula (1):

##STR00001##

(the numerals and signs in the general formula (1) are as described in the description).

An olefin-based copolymer and a method of making the same are disclosed herein. In some embodiments, an olefin-based copolymer has a density (d) of 0.85 to 0.89 g/cc, a melt index (MI), measured at 190° C. and 2.16 kg load, of 15 g/10 min to 100 g/10 min, a number of unsaturated functional groups (total V) per 1,000 carbon atoms of 0.8 or less, a vinylene content, and a vinyl content, wherein the vinylene content, the vinyl content and the total V satisfy (a) vinylene content/total V=0.1 to 0.7 and (b) vinylene content/vinyl content=0.8 to 1.6. The olefin-based copolymer has controlled content and kind of an unsaturated functional group in the olefin-based copolymer and thus, has high flowability, and may show improved physical properties of hardness, flexural strength and tensile strength.

Provided are a novel transition metal compound based on a cyclopenta[a]naphthalene group, a transition metal catalyst composition having high catalytic activity for preparing an ethylene homopolymer or a copolymer of ethylene and at least one α-olefin including the same, a method for preparing an ethylene homopolymer or a copolymer of ethylene and α-olefin using the same, and the ethylene homopolymer or the copolymer of ethylene and α-olefin prepared above. The metallocene compound according to the present invention and the catalyst composition including the same may provide a high thermal stability of the catalyst to maintain high catalytic activity even at a high temperature, have good copolymerization reactivity with other olefins, and prepare a high molecular weight polymer at a high yield.

The present invention relates to an olefin-based polymer, which has (1) a density (d) ranging from 0.85 to 0.90 g/cc, (2) a melt index (MI, 190° C., 2.16 kg load conditions) ranging from 0.1 g/10 min to 15 g/10 min, (3) the density (d) and the melt temperature (Tm) satisfying Tm (° C.)=a×d−b of Equation 1 (2,350<a<2,500, and 1,900<b<2,100), and (4) a ratio (hardness/Tm) of the hardness (shore A) to the melt temperature (Tm) in a range of 1.0 to 1.3. The olefin-based polymer according to the present invention exhibits excellent anti-blocking properties due to having improved hardness as a low-density olefin-based polymer.

The present invention relates to a novel ligand compound, a transition metal compound and a catalyst composition comprising the same. The novel ligand compound and the transition metal compound of the present invention may be useful as a catalyst of polymerization reaction for preparing an olefin-based polymer having a low density.

A metal complex of the formula (1) TCyLMZ.sub.p (1), wherein M is a group 4 metal, Z is an anionic ligand, p is the number 1 or 2, TCy is a thiophene-fused cyclopentadienyl-type ligand of the formula (2)

##STR00001##

is described. Methods of making and using the metal complex are also described.

The present invention relates to a method for evaluating an injection physical property of a plastic resin, and a polyethylene resin suitable for an injection molding process and, more particularly, to a novel method for evaluating an injection physical property of a plastic resin, which, when a particular plastic resin is processed by an injection process, can accurately derive injection suitability of the plastic resin and injection pressure in the injection process through a physical property value measured by using a resin specimen, and a polyethylene resin suitable for injection molding.

The present invention provides an adhesive composition including an ethylene/alpha-olefin copolymer; and a tackifier, wherein the ethylene/alpha-olefin copolymer has narrow molecular weight distribution together with a low density and an ultra low molecular weight, minimized number of unsaturated functional groups, uniform crystallinity, thereby showing excellent physical properties.

A polyethylene according to the present disclosure maintains a stable crystal structure at a high temperature and ensures excellent uniformity in chlorine distribution, thereby preparing a chlorinated polyethylene having excellent chlorination productivity and thermal stability by reacting with chlorine, and may also prepare a PVC compound with improved impact strength by including the chlorinated polyethylene.

The metallocene compound represented by the following general formula (1): ##STR00001##
(the numerals and signs in the general formula (1) are as described in the description).