Abstract: Provided is a high-purity isopropyl alcohol in which the concentration of a C7-12 acetal compound is 100 ppb or less on a mass basis, the concentration of the acetal compound in an accelerated test involving heating for 4 hours at 80° C. in a nitrogen atmosphere is increased by a factor of 30 or less with respect to the value thereof prior to heating, and the concentration of the acetal compound is maintained at a value of 100 ppb or less on a mass basis. Also provided is a method for manufacturing said high-purity isopropyl alcohol.

Abstract: Provided is a high-purity isopropyl alcohol in which the concentration of a C7-12 acetal compound is 100 ppb or less on a mass basis, the concentration of the acetal compound in an accelerated test involving heating for 4 hours at 80° C. in a nitrogen atmosphere is increased by a factor of 30 or less with respect to the value thereof prior to heating, and the concentration of the acetal compound is maintained at a value of 100 ppb or less on a mass basis. Also provided is a method for manufacturing said high-purity isopropyl alcohol.

Abstract: A method for producing isopropyl alcohol is provided in which propylene is hydrated directly with water to produce isopropyl alcohol, the method including: a distillation step in which crude isopropyl alcohol is distilled; and a filtration step in which the isopropyl alcohol obtained in the distillation step is filtered through a filter having an ion-exchange group.

Abstract: A method for producing isopropyl alcohol is provided in which propylene is hydrated directly with water to produce isopropyl alcohol, the method including: a distillation step in which crude isopropyl alcohol is distilled; and a filtration step in which the isopropyl alcohol obtained in the distillation step is filtered through a filter having an ion-exchange group.

Abstract: Provided is a high-purity isopropyl alcohol in which the concentration of a C7-12 acetal compound is 100 ppb or less on a mass basis, the concentration of the acetal compound in an accelerated test involving heating for 4 hours at 80° C. in a nitrogen atmosphere is increased by a factor of 30 or less with respect to the value thereof prior to heating, and the concentration of the acetal compound is maintained at a value of 100 ppb or less on a mass basis. Also provided is a method for manufacturing said high-purity isopropyl alcohol.

Abstract: The present invention provides a self-supporting substrate obtained by the steps of: forming an Al-based group-III nitride thin-layer having a thickness in the range of 3-200 nm on a base substrate made of a single crystal of an inorganic substance which substantially does not decompose at 800° C. in an inert gas atmosphere and which does produce volatiles by decomposition when contacting with a reducing gas in a temperature range of 800-1600° C., for example sapphire; forming voids along the interface between the base substrate and the Al-based group-III nitride thin-layer of the obtained laminated substrate by thermally treating the laminated substrate in a temperature range of 800-1600° C. in a reducing gas atmosphere containing ammonia gas; forming a group-III nitride single crystal thick-layer on the Al-based group-III nitride thin-layer; and separating these formed layers.

Abstract: The present invention is a method for producing a laminated body, comprising the steps of: (1) preparing a base substrate having a surface formed of a single crystal which is different from the material constituting the Al-based group-III nitride single crystal layer to be formed; (2) forming an Al-based group-III nitride single crystal layer having a thickness of 10 nm to 1.5 ?m on the single crystal surface of the prepared base substrate; (3) forming on the Al-based group-III nitride single crystal layer a non-single crystal layer being 100 times or more thicker than the Al-based group-III nitride single crystal layer without breaking the previously-obtained Al-based group-III nitride single crystal layer; and (4) removing the base substrate.