Provided are a pellet-type polyethylene resin composition capable of improving pipe pressure resistance property, dimensional stability, and processability at the same time, and a method of preparing the same.

Provided are a pellet-type polyethylene resin composition capable of improving pipe pressure resistance property, dimensional stability, and processability at the same time, and a method of preparing the same.

This disclosure provides new methods for the design and development of ethylene polymerization catalysts, including Group 4 metallocene catalysts such as zirconocenes, which are based on an improved ability to adjust co-monomer incorporation into the polymer. Computational analyses with and without dispersion corrections revealed that designing catalyst scaffolds which induce stabilizing non-covalent dispersion type interactions with incoming α-olefin co-monomers can be used to modulate co-monomer selectivity into the polyethylene chain. Demonstrated herein is a lack of correlation of computed ΔΔG.sup.‡ values against experimental ΔΔG.sup.‡ values when the dispersion correction (D3BJ) was disabled, and B3LYP was used in the absence of Grimme's D3 dispersion and Becke-Johnson (BJ) dampening, but a correlation of computed against experimental ΔΔG.sup.‡ with B3LYP+D3BJ, which are used to design new catalyst scaffolds.

This disclosure provides new methods for the design and development of ethylene polymerization catalysts, including Group 4 metallocene catalysts such as zirconocenes, which are based on an improved ability to adjust co-monomer incorporation into the polymer. Computational analyses with and without dispersion corrections revealed that designing catalyst scaffolds which induce stabilizing non-covalent dispersion type interactions with incoming α-olefin co-monomers can be used to modulate co-monomer selectivity into the polyethylene chain. Demonstrated herein is a lack of correlation of computed ΔΔG.sup.‡ values against experimental ΔΔG.sup.‡ values when the dispersion correction (D3BJ) was disabled, and B3LYP was used in the absence of Grimme's D3 dispersion and Becke-Johnson (BJ) dampening, but a correlation of computed against experimental ΔΔG.sup.‡ with B3LYP+D3BJ, which are used to design new catalyst scaffolds.

The purpose of the present invention is to obtain an ethylene⋅α-olefin⋅non-conjugated polyene copolymer that has a low permanent compression set at low temperatures, is flexible, and has an excellent balance of rubber elasticity at low temperatures and tensile strength at normal temperatures. This ethylene-based polymer is an ethylene⋅α-olefin⋅non-conjugated polyene copolymer that includes units derived from ethylene (A), units derived from an α-olefin (B) containing 4-20 carbon atoms, and units derived from a non-conjugated polyene (C) and satisfies (1)-(4). (1) The molar ratio of (A) to (B) is 40/60-90/10, (2) the contained amount of the units derived from (C) is 0.1-6.0 mol %, (3) ML.sub.(1+4)125° C. is 5-100, and (4) the B value is 1.20 or more.

The purpose of the present invention is to obtain an ethylene⋅α-olefin⋅non-conjugated polyene copolymer that has a low permanent compression set at low temperatures, is flexible, and has an excellent balance of rubber elasticity at low temperatures and tensile strength at normal temperatures. This ethylene-based polymer is an ethylene⋅α-olefin⋅non-conjugated polyene copolymer that includes units derived from ethylene (A), units derived from an α-olefin (B) containing 4-20 carbon atoms, and units derived from a non-conjugated polyene (C) and satisfies (1)-(4). (1) The molar ratio of (A) to (B) is 40/60-90/10, (2) the contained amount of the units derived from (C) is 0.1-6.0 mol %, (3) ML.sub.(1+4)125° C. is 5-100, and (4) the B value is 1.20 or more.

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).

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).

Metallocene complexes represented by the structure below are useful for alpha olefin oligomerization in the presence of an activator to generate polyalphaolefins having a high percentage of vinylidene termination and relatively low Mn values. ##STR00001##
M is a group 4 transition metal. A is a bridging group having one bridging atom extending between a first indenyl ring and a second indenyl ring. Each X is independently an anionic ligand, or two Xs are joined and bound to M to form a metallocycle ring, or two Xs are joined to form a chelating ligand, a diene ligand, or an alkylidene ligand. R.sup.1, R.sup.1′, R.sup.3, R.sup.3′, R.sup.4, R.sup.4′, R.sup.7 and R.sup.7′ are hydrogen. R.sup.5, R.sup.5′, R.sup.6, and R.sup.6′ are independently a C.sub.1-C.sub.10, optionally substituted, hydrocarbyl group, or R.sup.5 and R.sup.6 and/or R.sup.5′ and R.sup.6′ are bonded together to form an optionally substituted hydrocarbyl ring structure.

Metallocene complexes represented by the structure below are useful for alpha olefin oligomerization in the presence of an activator to generate polyalphaolefins having a high percentage of vinylidene termination and relatively low Mn values. ##STR00001##
M is a group 4 transition metal. A is a bridging group having one bridging atom extending between a first indenyl ring and a second indenyl ring. Each X is independently an anionic ligand, or two Xs are joined and bound to M to form a metallocycle ring, or two Xs are joined to form a chelating ligand, a diene ligand, or an alkylidene ligand. R.sup.1, R.sup.1′, R.sup.3, R.sup.3′, R.sup.4, R.sup.4′, R.sup.7 and R.sup.7′ are hydrogen. R.sup.5, R.sup.5′, R.sup.6, and R.sup.6′ are independently a C.sub.1-C.sub.10, optionally substituted, hydrocarbyl group, or R.sup.5 and R.sup.6 and/or R.sup.5′ and R.sup.6′ are bonded together to form an optionally substituted hydrocarbyl ring structure.