Abstract: A corrosion inhibitor for magnesium and/or magnesium alloy containing, as an effective component, a least one kind of compound selected from the group consisting of a compound of the formula (1) and a compound of the formula (2) and salts thereof, and a process for producing components or parts made of magnesium and/or magnesium alloy using the corrosion inhibitor wherein R1 is a hydrogen atom, or C1-4 alkyl, R2 is a hydrogen atom, C1-4 alkyl, mercapto or hydroxy, R3 is a hydrogen atom, C1-4 alkyl or hydroxy, A is —N? or —C(R4)?, R4 is a hydrogen atom or amino.

Abstract: A process for preparing a treated magnesium and/or magnesium alloy component comprising (A) treating the magnesium and/or magnesium alloy component with a surface treating agent containing a phosphate, (B) treating the component with a pre-treating agent used before a corrosion inhibition treatment, (C) treating the component, as required, with a cleaning agent containing surfactant and at least one compound selected from among aromatic carboxylic acids and salts thereof, and thereafter (D) treating the component further as required, with a corrosion inhibitor for magnesium.

Abstract: A process for preparing a treated magnesium and/or magnesium alloy component comprising (A) treating the magnesium and/or magnesium alloy component with a surface treating agent containing a phosphate,

Abstract: The present invention provides a corrosion inhibitor composition for magnesium or magnesium alloys which contains as an effective component, at least one compound selected from among aromatic carboxylic acids and salts thereof as an effective component. Further, the present invention provides a surface treating agent for magnesium and/or magnesium alloy components which contains a phosphate, at least one compound selected from among aromatic carboxylic acids and salts thereof, and further, as required, at least one compound selected from among pyrazole compounds and triazole compounds,and surface-treating method using the surface treating agent.

Abstract: The cleaner of the present invention contains, as an active ingredient, a polyphosphoric-acid-urea condensate or phosphoric-acid-urea polymer which is a reaction product from orthophosphoric acid and urea and is used for cleaning a metal surface and/or a glass surface in at least one process of a semiconductor device production process and a liquid crystal device production process. According to the present invention, an etching residue and impurities on metal (including semimetal) and glass surfaces can be cleaned off with high environmental and working safety and effectively without causing the problem of metal corrosion.