Abstract: A surface-treated copper foil according to exemplary embodiments includes a copper foil layer and a protrusion layer formed on one surface of the copper foil layer. Pores are formed inside the protrusion layer or around a boundary between the copper foil layer and the protrusion layer. Abnormal growth of the protrusions may be prevented through the pores and thus a bonding force with the insulation layer may be improved.

Abstract: A silicon carbide powder including carbon; and silicon, wherein a flow index under a major principal consolidation stress of 9 kPa is 0.005 to 0.3, and a flow index under a major principal consolidation stress of 0.3 kPa is 0.01 to 0.5.

Abstract: A silicon carbide powder including carbon; silicon; and an oxide film having a thickness of 0.1 nm to 10 nm is provided.

Abstract: A silicon carbide powder having silicon carbide particles including carbon and silicon, wherein a mass ratio of silicon carbide particles having a particle diameter of less than 50 ?m after sonication is 10 Wt % or less.

Abstract: A polythiol composition according to exemplary embodiments includes a first polythiol compound which provides a maximum peak in a high performance liquid chromatography (HPLC) analysis graph obtained at a wavelength of 230 nm, and a second polythiol compound having a molecular weight greater than that of the first polythiol compound and represented by C9H20S6. A ratio of a peak area of the second polythiol compound to a peak area of the first polythiol compound, which are measured through the HPLC analysis graph at the wavelength of 230 nm, is 0.05 to 5.0%.

Abstract: A polythiol composition according to exemplary embodiments includes a main polythiol compound and a sub-compound having a molecular weight higher than that of the main polythiol compound. A peak area (%) at retention times ranging from 34 to 40 minutes in the high performance liquid chromatography (HPLC) analysis graph obtained at a wavelength of 230 nm, which corresponds to the sub-compound, is 2.5% or less. An optical product having improved transmittance and optical properties may be manufactured through fine adjustment of the sub-compound.

Abstract: The wafer having a retardation distribution measured with a light having a wavelength of 520 nm, wherein an average value of the retardation is 38 nm or less, wherein the wafer comprises a micropipe, and wherein a density of the micropipe is 1.5/cm2 or less, is disclosed.

Abstract: The diamine composition according to an embodiment of the present invention comprises a benzylmonoamine having a methyl group in an amount of 10 ppm to 2,000 ppm in the composition. When it is used for the preparation of a diisocyanate composition and an optical material, it is possible to improve the optical characteristics by preventing the occurrence of yellowing, striae, and cloudiness in the optical material and enhancing the mechanical properties such as impact resistance at the same time. In addition, in the process for preparing a diisocyanate composition according to another embodiment, the b* value according to the CIE color coordinate of a diamine composition is adjusted to a specific range, whereby it is possible to enhance not only the yield and purity of the diisocyanate composition but also the optical characteristics of the final optical lens. Thus, the process for preparing a diisocyanate composition can be applied to the preparation of a plastic optical lens of high quality.

Abstract: A diamine composition comprising a benzylmonoamine having a methyl group in an amount of 10 ppm to 2,000 ppm in the composition and use thereof for the preparation of a diisocyanate composition and an optical material. A process for preparing a diisocyanate composition wherein the b* value according to the CIE color coordinate of the diamine composition is adjusted to a specific range, whereby the yield and purity of the diisocyanate composition and the optical characteristics of the final optical lens are enhanced. Use of the process for the diisocyanate composition for preparing a plastic optical lens of high quality.

Abstract: In the embodiments, an aqueous hydrochloric acid solution instead of hydrogen chloride gas and solid triphosgene instead of phosgene gas may be used in the process of preparing a diisocyanate from a diamine through a diamine hydrochloride. In addition, the embodiments provide processes for preparing a diisocyanate composition and an optical lens of high quality in which the content of water, the content of cations, or the content of an aromatic compound containing 3 or more of chlorine (Cl) in the organic solvent used in the reaction of a diamine hydrochloride composition and triphosgene is adjusted to a specific range.

Abstract: A method for preparing a SiC ingot includes: preparing a reactor by disposing a raw material in a crucible body and disposing a SiC seed in a crucible cover, and then wrapping the crucible body with a heat insulating material having a density of 0.14 to 0.28 g/cc; and growing the SiC ingot from the SiC seed by placing the reactor in a reaction chamber and adjusting an inside of the reactor to a crystal growth atmosphere such that the raw material is vapor-transported and deposited to the SiC seed.

Abstract: Disclosed are a silicon carbide powder and a method of manufacturing a silicon carbide ingot using the same. More particularly, the silicon carbide powder includes carbon and silicon and has a particle circularity of 0.4 to 0.9 measured through 2D image analysis.

Abstract: Disclosed are a silicon carbide powder, a method of manufacturing a silicon carbide powder, and a silicon carbide wafer. More particularly, the silicon carbide powder includes carbon and silicon and in the silicon carbide powder, O1s/C1s of a surface measured by X-ray photoelectron spectroscopy is 0.28 or less.

Abstract: Disclosed are a silicon carbide wafer and a method of manufacturing the same. The silicon carbide wafer includes an upper surface and a lower surface, the upper surface includes a first target region, the first target region being within 85% of a radius of the upper surface based on a center of the upper surface, a first peak omega angle measured at intervals of 15 mm in a first direction in the first target region is within ?1° to +1° based on a peak omega angle measured at the center of the upper surface, and the first direction is a [1-100] direction and a direction passing through the center of the upper surface.

Abstract: A graphite sheet having a ratio of thermal diffusivity in horizontal and vertical directions of 300 or more is disclosed. Also, a graphite sheet having a ratio of thermal diffusivity in a vertical direction of 2.0 mm2/s or less is disclosed. The graphite sheet has excellent thermal conductivity in horizontal and vertical directions and excellent flexibility at the same time and can be produced at low manufacturing cost, thereby holding an economic advantage.

Abstract: A silicon carbide wafer has one surface and the other surface opposite to the one surface. An average Rmax roughness of the one surface is 2.0 nm or less, and an average Ra roughness of the one surface is 0.1 nm or less. An edge region is a region in which a distance from an edge of the silicon carbide wafer toward a center is 5% to 75% of a radius of the silicon carbide wafer, and a central region is a region having a radius of 25% of the radius of the silicon carbide wafer at the center of the silicon carbide wafer. A difference between an average Rmax roughness of the edge region of the one surface and an average Rmax roughness of the central region of the one surface is 0.01 nm to 0.5 nm.

Abstract: In the embodiments, an aqueous hydrochloric acid solution and an organic solvent instead of hydrogen chloride gas and solid triphosgene instead of phosgene gas may be used in the process of preparing a diisocyanate from a diamine through a diamine hydrochloride. In addition, the embodiments provide processes for preparing a diisocyanate composition and an optical lens, which are excellent in yield and quality with mitigated environmental problems by controlling the total content of metals, cations, or anions in a diamine hydrochloride composition.

Abstract: A SiC ingot includes: a main body including a first cross-sectional plane of the main body and a second cross-sectional plane of the main body facing the first cross-sectional plane; and a protrusion disposed on the second cross-sectional plane and including a convex surface from the second cross-sectional plane of the main body, wherein a first end point disposed at one end of the second cross sectional plane, a second end point disposed at another end of the second cross sectional plane, and a peak point disposed on the convex surface are disposed on a third cross-sectional plane of the main body perpendicular to the first cross-sectional plane, and wherein a radius of curvature of an arc corresponding to a line of intersection between the third cross-sectional plane and the convex surface satisfies Equation 1 below: 3D?r?37D??[Equation 1] where r is the radius of curvature of the arc corresponding to the line of intersection between the third cross-sectional plane and the convex surface, and D is a leng

Abstract: A SiC ingot includes: a main body including a first cross-sectional plane of the main body and a second cross-sectional plane of the main body facing the first cross-sectional plane; and a protrusion disposed on the second cross-sectional plane and including a convex surface from the second cross-sectional plane of the main body, wherein a first end point disposed at one end of the second cross sectional plane, a second end point disposed at another end of the second cross sectional plane, and a peak point disposed on the convex surface are disposed on a third cross-sectional plane of the main body perpendicular to the first cross-sectional plane, and wherein a radius of curvature of an arc corresponding to a line of intersection between the third cross-sectional plane and the convex surface satisfies Equation 1 below: 3D?r?37D??[Equation 1] where r is the radius of curvature of the arc corresponding to the line of intersection between the third cross-sectional plane and the convex surface, and D is a lengt

Abstract: A method for preparing a SiC ingot includes preparing a crucible assembly comprising a crucible body having an internal space, loading a raw material into the internal space of the crucible body and placing a plurality of SiC seed in the internal space of the crucible body at regular intervals spaced apart from the raw material, and growing the SiC ingot from the plurality of SiC seed by adjusting the internal space of the crucible body to a crystal growth atmosphere such that the raw material is vapor-transported and deposited to the plurality of SiC seed. A density of the crucible body may be 1.70 to 1.92 g/cm3.