Abstract: To provide a reversibly thermochromic aqueous ink composition excellent in dispersion stability of a reversibly thermochromic microcapsule pigment and a writing instrument using the same. Disclosed is a reversibly thermochromic aqueous ink composition comprising a reversibly thermochromic microcapsule pigment encapsulating a reversibly thermochromic composition comprising (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) a reaction medium to determine an occurrence temperature of a coloring reaction of the component (a) and the component (b), and a vehicle comprising water and a specific gravity adjuster selected from the group consisting of an oxyacid belonging to Group 6 having an atomic weight of 90 to 185 or salt thereof.

Abstract: Disclosed is a photochromic composition comprising a naphthopyran-based photochromic compound having a specific structure and an oligomer.

Abstract: To provide a reversibly thermochromic aqueous ink composition excellent in dispersion stability of a reversibly thermochromic microcapsule pigment and a writing instrument using the same. Disclosed is a reversibly thermochromic aqueous ink composition comprising a reversibly thermochromic microcapsule pigment encapsulating a reversibly thermochromic composition comprising (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) a reaction medium to determine an occurrence temperature of a coloring reaction of the component (a) and the component (b), and a vehicle comprising water and a specific gravity adjuster selected from the group consisting of an oxyacid belonging to Group 6 having an atomic weight of 90 to 185 or salt thereof.

Abstract: A method for producing methanol allows the temperature of the catalyst layer to fall within an appropriate temperature range, reduces energy used, and achieves higher carbon yield. In a synthesis loop including at least two synthesis steps and two separation steps, a first mixed gas is obtained by mixing the final unreacted gas with a fraction of the make-up gas, methanol is synthesized from the first mixed gas after preheating, a first unreacted gas is separated from the obtained first reaction mixture, a final mixed gas is obtained by finally mixing the unreacted gas and a fraction of the make-up gas, the final mixed gas after preheating is further increased in pressure and then methanol is synthesized, a final unreacted gas is separated from the obtained final reaction mixture, and the reaction temperature of the catalyst layer is controlled by the indirect heat exchange with pressurized boiling water.

Abstract: A method for producing methanol allows the temperature of the catalyst layer to fall within an appropriate temperature range, reduces energy used, and achieves higher carbon yield. In a synthesis loop including at least two synthesis steps and two separation steps, a first mixed gas is obtained by mixing the final unreacted gas with a fraction of the make-up gas, methanol is synthesized from the first mixed gas after preheating, a first unreacted gas is separated from the obtained first reaction mixture, a final mixed gas is obtained by finally mixing the unreacted gas and a fraction of the make-up gas, the final mixed gas after preheating is further increased in pressure and then methanol is synthesized, a final unreacted gas is separated from the obtained final reaction mixture, and the reaction temperature of the catalyst layer is controlled by the indirect heat exchange with pressurized boiling water.

Abstract: Synthesizing methanol from a synthesis gas and separating an unreacted gas from a reaction mixture obtained by passing through the synthesis step, the method including a synthesis loop having at least two synthesis steps and at least two separation steps; obtaining a first mixed gas by increasing through a circulator a pressure of a residual gas, obtained by removing a purge gas from the final unreacted gas separated from the final reaction mixture subsequent to the final synthesis step, and by mixing the residual gas with a fraction of a make-up gas; synthesizing methanol; separating a first unreacted gas from the first reaction mixture obtained in the synthesizing step; obtaining a second mixed gas by mixing the first unreacted gas and a fraction of the make-up gas; finally synthesizing methanol; and separating the final unreacted gas from the final reaction mixture obtained in the final synthesis step.

Abstract: Synthesizing methanol from a synthesis gas and separating an unreacted gas from a reaction mixture obtained by passing through the synthesis step, the method including a synthesis loop having at least two synthesis steps and at least two separation steps; obtaining a first mixed gas by increasing through a circulator a pressure of a residual gas, obtained by removing a purge gas from the final unreacted gas separated from the final reaction mixture subsequent to the final synthesis step, and by mixing the residual gas with a fraction of a make-up gas; synthesizing methanol; separating a first unreacted gas from the first reaction mixture obtained in the synthesizing step; obtaining a second mixed gas by mixing the first unreacted gas and a fraction of the make-up gas; finally synthesizing methanol; and separating the final unreacted gas from the final reaction mixture obtained in the final synthesis step.