Abstract: An optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens sequentially disposed on an optical axis from an object side toward an image side. A distance from an object-side surface of the first lens to an imaging plane of an image sensor is TTL, an overall focal length of an optical system including the first to sixth lenses is F, and TTL/F?0.83. An optical axis distance between the second lens and the third lens is D23, an optical axis distance between the third lens and the fourth lens is D34, and 2.2<D23/D34<5.4.

Abstract: This invention relates to a method for producing multimodal polyolefin using multistage continuous polymerization process for producing multimodal polyolefin having superior melt-strength, moldability, mechanical strength, processability, and appearance. A method for producing multimodal polyolefin using multistage polymerization process, comprising the steps of: polymerizing a high molecular weight bimodal polymer by introducing a monomer in the presence of a catalyst composition including two or more different catalysts in a first reactor; and continuously introducing the high molecular weight bimodal polymer produced in the first reactor into a second reactor, and polymerizing a low molecular weight bimodal polymer by introducing a monomer in the presence of the catalyst composition, wherein the multimodal polyolefin includes the high molecular weight bimodal polymer and the low molecular weight bimodal polymer at the same time.

Abstract: This invention relates to a method for producing multimodal polyolefin using multistage continuous polymerization process for producing multimodal polyolefin having superior melt-strength, moldability, mechanical strength, processability, and appearance. A method for producing multimodal polyolefin using multistage polymerization process, comprising the steps of: polymerizing a high molecular weight bimodal polymer by introducing a monomer in the presence of a catalyst composition including two or more different catalysts in a first reactor; and continuously introducing the high molecular weight bimodal polymer produced in the first reactor into a second reactor, and polymerizing a low molecular weight bimodal polymer by introducing a monomer in the presence of the catalyst composition, wherein the multimodal polyolefin includes the high molecular weight bimodal polymer and the low molecular weight bimodal polymer at the same time.

Abstract: Multimodal polyolefin resins for manufacturing films, pipes, hollow molded articles having high melt strength and excellent formability, mechanical strength, processability and appearance are described. The resins have: density is 0.930-0.960 g/cm3; melt flow index is 0.01-10.0 g/10 minutes; ratio Mw/Mn is 10-60; and two or more peaks appear when molecular weight is measured by GPC. In molded pipe, the Mw of polymer collected at position B is 0.1% greater than Mw of polymer collected at position A; polymer having Mw of 10,000 or less among polymers collected at position A is 0.1% greater than the amount of polymer having Mw of 10,000 or less among polymers collected at position B; and the amount of polymer having Mw of 1,000,000 or more among polymers collected at position B is 0.1% greater than the amount of polymer having Mw of 1,000,000 or more among polymers collected at position A.

Abstract: Multimodal polyolefin resins for manufacturing films, pipes, hollow molded articles having high melt strength and excellent formability, mechanical strength, processability and appearance are described. The resins have: density is 0.930-0.960 g/cm3; melt flow index is 0.01-10.0 g/10 minutes; ratio Mw/Mn is 10-60; and two or more peaks appear when molecular weight is measured by GPC. In molded pipe, the Mw of polymer collected at position B is 0.1% greater than Mw of polymer collected at position A; polymer having Mw of 10,000 or less among polymers collected at position A is 0.1% greater than the amount of polymer having Mw of 10,000 or less among polymers collected at position B; and the amount of polymer having Mw of 1,000,000 or more among polymers collected at position B is 0.1% greater than the amount of polymer having Mw of 1,000,000 or more among polymers collected at position A.

Abstract: Multimodal polyolefin resin having superior characteristics including moldability, mechanical strength, external appearance, melt strength and a polyolefin resin molded product meeting the requirements: (1) polymerized in the presence of at least two different metallocene compounds as catalysts; (2) matrix index of 2 or less and a melt strength of 4.0 Force (cN) or greater at 190° C.; (3) melt flow index (MIP, 190° C., 5.0 kg load condition) of 0.01 to 5.0 g/10 min; (4) ratio (Mw/Mn, MWD) of weight average molecular weight (Mw) to number average molecular weight (Mn) of 5-35 as measured by gel permeation chromatography; and (5) bimodal or multimodal peaks in a weight average molecular weight distribution measured by gel permeation chromatography, wherein the height ratio of two peaks (the ratio of the height of low molecular weight peak to the height of high molecular weight peak) is 0.7-3.

Abstract: Multimodal polyolefin resin having superior characteristics including moldability, mechanical strength, external appearance, melt strength and a polyolefin resin molded product meeting the requirements: (1) polymerized in the presence of at least two different metallocene compounds as catalysts; (2) matrix index of 2 or less and a melt strength of 4.0 Force (cN) or greater at 190° C.; (3) melt flow index (MIP, 190° C., 5.0 kg load condition) of 0.01 to 5.0 g/10 min; (4) ratio (Mw/Mn, MWD) of weight average molecular weight (Mw) to number average molecular weight (Mn) of 5-35 as measured by gel permeation chromatography; and (5) bimodal or multimodal peaks in a weight average molecular weight distribution measured by gel permeation chromatography, wherein the height ratio of two peaks (the ratio of the height of low molecular weight peak to the height of high molecular weight peak) is 0.7-3.