Abstract: A method for polymerization and copolymerization of ethylene is disclosed. The polymerization is carried out in the presence of a preactivated titanium solid complex catalyst supported on a carrier containing magnesium. The resulting polymers have the advantage of high bulk density and broad molecular weight distribution.

Abstract: The present invention relates to a catalyst for homo-polymerization or co-polymerization of ethylene, or more particularly to a solid complex titanium catalyst for homo-polymerization or co-polymerization of ethylene. The catalyst may be produced by preparing a magnesium solution by contact-reacting a magnesium halide compound with an alcohol. Reacting the solution with an ester compound and a boron compound. Then reacting the solution with a mixture of a titanium compound and a silicon compound.

Abstract: The present invention relates to a method of estimating the properties of a polymer product by using converted process variables (cPV's) which means process variable that final or intermediate product experienced earlier in average in the reactors by stage with respect to the final product, which incorporates residence time distribution to process variables, wherein said method comprises the following steps of: computing cPV's by incorporating the residence time distribution to said process variables by means of theoretically determining the amounts of content and discharge of the product in the process, and then solving the balance equations of a hypothetical substance by taking the respective process variables as those of the hypothetical substance: and estimating the properties of the product by inputting to various property estimation models cPV's in the reactors by stage with respect to the final product after incorporating the residence time distribution to said process variables.

Abstract: The present invention relates to a preparation method of methacrylic acid which improves reaction selectivity of methacrylic acid. The method may include producing methacrylic acid by gas phase oxidation of methachrolane in the presence of catalyst. Particularly, the present invention relates to the preparation method of methacrylic acid comprising the step of introducing CO2 up to 3˜80 mole % of the feed gas in the presence off catalyst having the general formula of PaMo11VbXcYdOe. X may be one or more elements selected from the group of alkaline metal and Tl element. Y may be one or more elements selected from the group of Cu, Pb, Sb, Cr and Ce. In addition, a, b, c, d and e are the molar ratio of each necessary element when molybdenum is 11; where a is 0.8˜1.6, b is 0.6˜2, c is 0.8˜2.2, d is 0.1˜0.8 and e is a suitable value for elemental valency in the composition of said formula respectively.

Abstract: The new metallocene catalysts according to the present invention are prepared by reacting a metallocene compound with a compound having at least two functional groups. The metallocene compound is a transition metal compound which a transition metal is coordinated with a main ligand such as cycloalkanedienyl group and an ancillary ligand. The functional groups of the compound having at least two functional groups are selected from the group consisting of a hydroxy group, a thiol group, a primary amine group, a secondary amine group, etc. The metallocene catalysts according to the present invention have a structure which an ancillary ligand of a metallocene compound is bonded with functional groups. A structure of the metallocene catalysts can be varied according to the metallocene compounds, the compound having at least two functional groups, and the molar ratio of each reactant. The metallocene catalyst is employed with a co-catalyst for styrene and olefin polymerization.

Abstract: An alginate gel adsorbent to remove heavy metal ions according to the present invention is prepared by adding dropwisely 0.1-5 wt % alginate solution to a polyvalent cationic solution thereby cross-linking alginic acid with polyvalent cations. An alginate gel adsorbent containing activated carbon capable of simultaneously removing heavy metal ions and organotoxic materials, that is, activated carbon/alginate gel adsorbent, is prepared by adding dropwisely a mixed solution of 0.17-10 wt % of alginate and 0.1-10 wt % of activated carbon powder to a polyvalent cationic solution thereby cross-linking alginic acid with polyvalent cations in order to immobilize polyvalent cation to alginic acid containing activated carbon. The polyvalent cationic solution is selected from the group consisting of calcium chloride (CaCl2), strontium chloride (SrCl2), barium chloride (BaCl2) and aluminium chloride (AlCl3).

Abstract: A solid titanium complex catalyst for polymerization and copolymerization of ethylene is prepared by the process comprising: (1) preparing a magnesium solution by reacting a halogenated magnesium compound with an alcohol; (2) reacting the magnesium solution with a phosphorus compound and a silicon compound having at least one alkoxy group to produce a magnesium composition; and (3) producing a solid titanium catalyst through recrystallization by reacting the magnesium composition solution with a mixture of a titanium compound and a haloalkane compound; and optionally reacting the solid titanium catalyst with an additional titanium compound. The solid titanium complex catalyst for polymerization and copolymerization of ethylene according to present invention exhibits high polymerization activity, and may be advantageously used in the polymerization and copolymerization of ethylene to produce polymers of high bulk density and narrow molecular weight distribution.

Abstract: Described herein is a prepolymerized catalyst encapsulated with macromolecular monomers which is prepared by adding olefin mononers and diene compounds to a solid complex titanium catalyst for olefin polymerization and then polymerizing, and also relates to a method for polymerization or copolymerization capable of preparing polyolefins with high melt strength by polymerizing the olefin by using said catalyst.

Abstract: A solid titanium complex catalyst for polymerization and copolymerization of ethylene is prepared by the process comprising: (1) preparing a magnesium solution by reacting a halogenated magnesium compound with an alcohol; (2) reacting the magnesium solution with an ester compound having at least one hydroxyl group and a boron compound having at least one alkoxy group to produce a magnesium composition; and (3) producing a solid titanium catalyst through recrystallization by reacting the magnesium composition solution with a mixture of a titanium compound and a haloalkane compound; and optionally reacting the solid titanium catalyst with an additional titanium compound.

Abstract: Disclosed is a preparation method of an exfoliated nitropolymer/silicate nanocomposite by emulsion polymerization of monomers forming the polymer in an aqueous dispersion of non-modified, layered silicate in the presence of a reactive emulsifier having both a radical-polymerizable vinyl group and a functional group with affinity for silicate. In the process of the polymerization, silicate is fully exfoliated and uniformly dispersed in the polymer. Therefore, only a small amount of silicate is sufficient to improve thermal and mechanical properties of the polymer. Further, the method is advantageous in terms of a simple preparation process due to no use of organo-modified silicate, thus achieving an economic benefit.

Abstract: The present invention relates to a catalyst for homo-polymerization or co-polymerization of ethylene, or more particularly to a solid complex titanium catalyst for homo-polymerization or co-polymerization of ethylene. The catalyst may be produced by preparing a magnesium solution by contact-rcacting a magnesium halide compound with alcohol. Reacting the solution with an ester compoound and a silicon compound. Then reacting the solution with a mixture of a titanium compound and a silicon compound.

Abstract: A solid titanium complex catalyst for polymerization and copolymerization of ethylene is prepared by the process that includes: (1) preparing a magnesium solution by reacting a halogenated magnesium compound with an alcohol; (2) reacting the magnesium solution with an ester compound having at least one hydroxyl group and a silicon compound having an alkoxy group to produce a magnesium composition; and (3) producing a solid titanium catalyst by reacting the magnesium composition solution with a mixture of a titanium compound and a haloalkane compound; and optionally reacting the solid titanium catalyst with an additional titanium compound.

Abstract: The present invention relates to a catalyst for homo-polymerization or co-polymerization of ethylene, or more particularly to a solid complex titanium catalyst for homo-polymerization or co-polymerization of ethylene. The catalyst may be produced by preparing a magnesium solution by contact-reacting a magnesium halide compound with an alcohol. Reacting the solution with an ester compound and a boron compound. Then reacting the solution with a mixture of a titanium compound and a silicon compound.

Abstract: The present invention relates to a catalyst for homo- or co-polymerization of ethylene, or more particularly to a solid titanium catalyst supported on a magnesium-containing carrier, having high catalytic activity and excellent polymerization properties, which can provide polymers of high bulk density and reduce the amount of polymers dissolvable in a medium during polymerization.

Abstract: The present invention relates to a method for producing a polymer and copolymer of ethylene, and more particularly to a method for producing an ethylene polymer and copolymer by reacting a compound of an organic metal of Group 2, 12, or 13 on the periodic table of elements with an alkoxy silane compound in the presence of a titanium catalyst, the said titanium catalyst being produced by a process of preparing a magnesium compound by contact-reacting a halogenated magnesium compound and alcohol, of reacting the said solution with an ester compound which contains at least one hydroxy group and a silicon compound containing an alkoxy group, and also of reacting it with a solid matter obtained by reaction of a mixture of a titanium compound and a silicon compound with a titanium compound.

Abstract: The present invention relates to a solid complex titanium catalyst for homo-polymerization and co-polymerization of &agr;-olefin, obtained by (i) producing a solution of a magnesium compound by dissolving a magnesium compound and a compound of IIIA Group of the Periodic Table in a solvent mixed with cyclic ether, one or more types of alcohol, a phosphorous compound, and an organosilane, (ii) precipitating the solid particles by reacting said magnesium solution with a compound of a transition metal, a silicon compound, or the mixture thereof, and (iii) reacting said precipitated solid particles with a titanium compound and an electron donor. The catalyst of the present invention is of large particle size, narrow particle distribution, and high catalytic activity, while the polymers obtained with the use of this catalyst are of excellent stereoregularity.

Abstract: The present invention provides a flame retardant resin composition, or more particularly, a flame retardant polypropylene resin composition which comprises polypropylene having improved flow melt characteristics, flame retardants, a flame retardant aid, and a tetrafluoroethylene polymer. The composition of the present invention has high melt tension, without deterioration of the mechanical properties of flame retardant polypropylene, and drastically enhanced characteristics of shape maintenance and a flaming drip during burning.

Abstract: The new metallocene catalysts according to the present invention are prepared by reacting a metallocene compound with a compound having at least two functional groups. The metallocene compound is a transition metal compound which a transition metal is coordinated with a main ligand such as cycloalkanedienyl group and an ancillary ligand. The functional groups of the compound having at least two functional groups are selected from the group consisting of a hydroxy group, a thiol group, a primary amine group, a secondary amine group, etc. The metallocene catalysts according to the present invention have a structure which an ancillary ligand of a metallocene compound is bonded with functional groups. A structure of the metallocene catalysts can be varied according to the metallocene compounds, the compound having at least two functional groups, and the molar ratio of each reactant. The metallocene catalyst is employed with a co-catalyst for styrene and olefin polymerization.

Abstract: The present invention relates to a catalyst for polymerization and co-polymerization of ethylene. More particularly, the present invention relates to a solid titanium catalyst containing magnesium, wherein said catalyst is produced by preparing a magnesium solution by contact-reacting a halogenated magnesium compound with alcohol; reacting said solution with an ester compound having at least one hydroxy group, or a phosphorous compound and a silicon compound having alkoxy groups; producing a solid component with an adjusted particle morphology by adding a mixture of a titanium compound and a silicon compound; reacting the same with an aluminum compound; and then reacting the same with a titanium compound, or a titanium compound and a vanadium compound. As a result, the catalyst of the present invention has high catalytic activity with excellent catalyst morphology.

Abstract: The present invention relates to catalyst compositions for purifying terephthalic acid from p-carboxybenzaldehyde, based on Group VIII metals, comprising crystallites of catalytically active palladium or of palladium and at least one metal of Group VIII of the Periodic Table of Elements, applied to the surface of a carbon material, wherein a mesoporous graphite-like material with the average mesopore size in the range of from 40 to 400 Å, the proportion of the mesopores in the total pore volume of at least 0.5, and the degree of graphite-similarity of at least 20% is used as the carbon material, in which metal crystallites are distributed in the volume of the carbon material granules in such a manner that the distribution peaks of these crystallites should be at a distance from the outer surface of the granule corresponding to 1-30% of its radius.