The present invention relates to a vinyl chloride polymer and a production method thereof. More specifically, the present invention provides a vinyl chloride polymer having a polydispersity index of 2.0 to 2.3 and a porosity of 60% or greater and a production method thereof in which a vinyl chloride polymerization seed having a conversion rate of 5-20% is first prepared through preliminary polymerization and then a vinyl chloride monomer is introduced into the vinyl chloride polymerization seed to polymerize (main polymerization) a vinyl chloride polymer.

A polyethylene powder satisfying (Requirements 1 to 3):

(Requirement 1): viscosity-average molecular weight (Mv) is 200,000 or more and 3,000,000 or less
(Requirement 2): complex viscosity |η*|.sub.m obtained by measurement under predetermined <Conditions for Measurement of Slurry Viscoelasticity>satisfies the following formula (1):
590.0×(Mv×10.sup.−4).sup.1.18≥|η*|.sub.m≥13.3×(Mv×10.sup.−4).sup.1.18 (1)
(Requirement 3): a value of any peak when d(log|η*|)/dT is plotted against temperature is 1.0 or more and 3.0 or less.

A polyethylene powder satisfying (Requirements 1 to 3):

(Requirement 1): viscosity-average molecular weight (Mv) is 200,000 or more and 3,000,000 or less
(Requirement 2): complex viscosity |η*|.sub.m obtained by measurement under predetermined <Conditions for Measurement of Slurry Viscoelasticity>satisfies the following formula (1):
590.0×(Mv×10.sup.−4).sup.1.18≥|η*|.sub.m≥13.3×(Mv×10.sup.−4).sup.1.18 (1)
(Requirement 3): a value of any peak when d(log|η*|)/dT is plotted against temperature is 1.0 or more and 3.0 or less.

Methods to produce heterogeneous polyethylene granules, the method including: contacting first olefin monomers and second olefin monomers with a catalyst system in a single reaction zone to produce heterogeneous polyethylene granules and recovering the heterogeneous polyethylene granules; wherein the catalyst system includes a product of a combination including: one or more catalysts having a Group 3 through Group 12 metal atom or lanthanide metal atom; at least one activator; and optionally, one or more support material compositions; and wherein the heterogeneous polyethylene granules include a product of a combination of: a first portion comprising a first polyethylene including the first olefin monomers and the second olefin monomers; a second portion including a second polyethylene including the first monomers and the second monomers; and wherein the first polyethylene has a higher second monomer weight percent than the second polyethylene, are provided.

Methods to produce heterogeneous polyethylene granules, the method including: contacting first olefin monomers and second olefin monomers with a catalyst system in a single reaction zone to produce heterogeneous polyethylene granules and recovering the heterogeneous polyethylene granules; wherein the catalyst system includes a product of a combination including: one or more catalysts having a Group 3 through Group 12 metal atom or lanthanide metal atom; at least one activator; and optionally, one or more support material compositions; and wherein the heterogeneous polyethylene granules include a product of a combination of: a first portion comprising a first polyethylene including the first olefin monomers and the second olefin monomers; a second portion including a second polyethylene including the first monomers and the second monomers; and wherein the first polyethylene has a higher second monomer weight percent than the second polyethylene, are provided.

A process for preliminary polymerization may include washing a catalyst mud comprising a supported metallocene catalyst with at least one saturated hydrocarbon at a temperature from 0° C. to 40° C., a pressure from 20 to 40 kgf/cm.sup.2, and a residence time of at least 30 minutes; continuously feeding the washed catalytic mud to a continuous pre-polymerization reactor; and pre-polymerizing, in the continuous pre-polymerization reactor, ethylene and at least one C.sub.4 to C.sub.10 α-olefin as comonomer, with the washed catalytic mud, to produce a pre-polymer; wherein an average residence time in the continuous pre-polymerization reactor is more than 90 minutes and less than 240 minutes, a reactor temperature is from 10° C. to 50° C., and a reactor pressure from 20 to 40 kgf/cm.sup.2.

A process for preliminary polymerization may include washing a catalyst mud comprising a supported metallocene catalyst with at least one saturated hydrocarbon at a temperature from 0° C. to 40° C., a pressure from 20 to 40 kgf/cm.sup.2, and a residence time of at least 30 minutes; continuously feeding the washed catalytic mud to a continuous pre-polymerization reactor; and pre-polymerizing, in the continuous pre-polymerization reactor, ethylene and at least one C.sub.4 to C.sub.10 α-olefin as comonomer, with the washed catalytic mud, to produce a pre-polymer; wherein an average residence time in the continuous pre-polymerization reactor is more than 90 minutes and less than 240 minutes, a reactor temperature is from 10° C. to 50° C., and a reactor pressure from 20 to 40 kgf/cm.sup.2.

The present disclosure relates to a Ziegler-Natta catalyst system with self-extinguishing properties suitable for olefin polymerization. The catalyst system of the present disclosure comprises a pro-catalyst, a co-catalyst, and an external donor having a mixture of a selectivity control agent and an activity control agent. The catalyst system of the present disclosure is adapted to prevent the temperature of the polymerization reaction to go beyond the softening temperature of the polymer, thereby exhibiting the self-extinguishing properties.

The present disclosure relates to a Ziegler-Natta catalyst system with self-extinguishing properties suitable for olefin polymerization. The catalyst system of the present disclosure comprises a pro-catalyst, a co-catalyst, and an external donor having a mixture of a selectivity control agent and an activity control agent. The catalyst system of the present disclosure is adapted to prevent the temperature of the polymerization reaction to go beyond the softening temperature of the polymer, thereby exhibiting the self-extinguishing properties.

A spray-dried zirconocene catalyst system comprising a zirconocene catalyst and a hydrophobic fumed silica, which supports the zirconocene catalyst. A spray-drying method of making same. Polyolefins; methods of making and using same; and articles containing same.