Abstract: A polycarbonate-polysiloxane copolymer includes a polysiloxane unit. The polycarbonate-polysiloxane copolymer can have superior melt flowability and ductility while maintaining high transparency and low haze.

Abstract: A polycarbonate resin includes a repeating unit in its main chain of the following Chemical Formula 1: wherein the substituents are as defined in the specification.

Abstract: The present invention provides a catalyst for synthesizing an aromatic carbonate, a method of preparing the same, and a method of preparing an aromatic carbonate from dialkyl carbonate using the catalyst. The catalyst has a unit structure consisting of Formulae 1a, 1b or 1c: wherein R1 is C1-C5 alkyl, R2 is substituted or unsubstituted phenyl.

Abstract: A method of preparing aromatic carbonate from dialkyl carbonate includes reacting an aromatic hydroxyl compound and dialkyl carbonate in the presence of at least one type of samarium-containing catalyst represented by Formula 1, Formula 2, or a combination thereof: SmX3??[Formula 1] wherein each X is the same or different and is independently C1 to C10 alkoxy, C1 to C10 alkyl phenoxy or phenoxy, and wherein R1 and R2 are the same or different and are independently hydrogen or C1 to C6 alkyl.

Abstract: A polycarbonate-polysiloxane copolymer includes a polysiloxane unit. The polycarbonate-polysiloxane copolymer can have superior melt flowability and ductility while maintaining high transparency and low haze.

Abstract: A method of preparing aromatic carbonate from dialkyl carbonate includes reacting an aromatic hydroxyl compound and dialkyl carbonate in the presence of at least one type of samarium-containing catalyst represented by Formula 1, Formula 2, or a combination thereof: SmX3 ??[Formula 1] wherein each X is the same or different and is independently C1 to C10 alkoxy, C1 to C10 alkyl phenoxy or phenoxy, and wherein R1 and R2 are the same or different and are independently hydrogen or C1 to C6 alkyl.

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: A method for producing a catalyst for the polymerization or copolymerization of olefins is described. The method includes producing a magnesium compound solution by reacting a magnesium halide compound in the mixture of a cyclic ether and two alcohols with an organosilane compound. The magnesium compound solution may be reacted with a titanium halide compound such that precipitated solid components are formed. These precipitated solid components may be reacted with a titanium compound and an electron donor to produce the polymerization catalyst.