SURFACE-CONDITIONING COMPOSITION, METHOD FOR PRODUCTION THEREOF, AND SURFACE CONDITIONING METHOD

摘要

Disclosed is a surface-conditioning composition which has an improved surface-conditioning function and, therefore, can improve a chemical conversion property (for example, can form a dense metal phosphate coating film on the surface of a metal material), can form a chemical conversion coating film having a satisfactory coating weight even when applied to a contact area between different metal materials in the simultaneous chemical conversion treatment of the different metal materials or a hardly convertible metal material (e.g., a high tensile strength steel plate), and can improve the productivity rate of the chemical conversion treatment (for example, can improve a chemical conversion property, resulting in the reduction of the time required for the chemical conversion treatment). A surface-conditioning composition which comprises a particle of a phosphate of a bivalent or trivalent metal and has a pH value ranging from 3 to 12. The particle has a D₅₀ value of 3 µm or less. The composition contains an amine compound having a molecular weight of 1000 or less.