DYE COMPOSITION FOR COLORING HARD OR SUPER HARD ANODIC OXIDATION COATING OF ALUMINUM OR ALUMINUM ALLOY

摘要

PROBLEM TO BE SOLVED: To obtain a composition having an excellent coloring property without causing nonuniform dyeing by blending a specific amount of a dye. ;SOLUTION: This composition contains at least 2 wt.% of a dye in the total amount of the composition. This dye composition for coloring contains a dye, a polyhydric alcohol, water, optionally a surfactant and other additives. Preferably, the polyhydric alcohol is one or more selected from ethylene glycol, propylene glycol and glycerin. The dye composition preferably has a viscosity of at least 2.2 mPa.s (an ECD type viscometer, 3°R14 rotor, rotation speed: 100 rpm, 20°C) and a pH in the weak base range of 7-9. This dye composition has a dyeing property to give a high color density to a (super) hard anodic oxidation coating of an aluminum (alloy). To dye the aluminum (alloy), the aluminum (alloy) is soaked in the dye composition to have the dye adsorbed on the surface of the coating is washed with water, and is subjected to a sealing treatment.;COPYRIGHT: (C)2000,JPO