Patent ID: 7521518
Filing Date: 2009-04-21
Classification: C07F,C08F,Y10T

Abstract:
1. An ethylene copolymer comprising repeating units of ethylene and at least one comonomer, selected from the group consisting of: (a) compounds represented by the formula H 2 C═CHR, wherein R is a C 1 -C 20 linear, branched or cyclic alkyl group or a C 6 -C 20 aryl group, and (b) a C 4 -C 20 diene, where the diene is linear, branched or cyclic, and wherein the ethylene copolymer has the following properties (1) to (5): (1) a density d (g/cm (2) an M (3) when, in cross fractionation chromatography (CFC) of the ethylene copolymer, with respect to extraction at an arbitrary temperature T(° C.), falling within the range between a first temperature, at which a maximum amount of extraction is exhibited, and a second temperature, which is 10° C. higher than the first temperature, the relationship between the arbitrary temperature T(° C.), and a point in molecular weight on a molecular weight distribution profile of a copolymer fraction extracted at the arbitrary temperature T(° C.), at which point in molecular weight, the molecular weight distribution profile of the copolymer fraction shows a peak having a maximum intensity, is treated by the least squares method to obtain an approximate straight line, and wherein the approximate straight line has a gradient within the range defined by the formula (I): wherein: T 1 and T 2 are two different arbitrary extraction temperatures T(° C.) within the range between the first temperature and the second temperature, and Mp(T 1 ) and Mp(T 2 ) are, respectively, molecular weights corresponding to T 1 and T 2 on the approximate straight line; and (4) the measurement of the ethylene copolymer by CFC shows characteristics, such that the sum of respective amounts of copolymer fractions extracted at temperatures, which are at least 10° C. lower than the first temperature, as defined above, is 8% by weight or less, based on the total amount of, excluding purge, copolymer fractions extracted at temperatures in the overall range of extraction temperatures in CFC; (5) within a range in molecular weight of the ethylene copolymer, which is defined by the formula (II): wherein: Mt is a point in molecular weight on a molecular weight distribution profile at which the profile shows a peak having a maximum intensity, and Mc is an arbitrary point in molecular weight on the molecular weight distribution profile, the molecular weight distribution profile is obtained, together with a comonomer content distribution profile, by subjecting the ethylene copolymer to gel permeation chromatography/Fourier transformation infrared spectroscopy (GPC/FT-IR), and an approximate straight line, obtained from the comonomer content distribution profile by the least squares method, has a gradient within the range defined by the formula (III): wherein: Mc 1 and Mc 2 are two different arbitrary points (Mc) in molecular weight, which satisfy the formula (II), and C(Mc 1 ) and C(Mc 2 ) are, respectively, comonomer contents corresponding to Mc 1 and Mc 2 on the approximate straight line; and wherein the ethylene copolymer is prepared in the presence of a transition metal compound which contains only one cyclic π-bonded anionic ligand.