Patent ID: 11926889
Assignee: MITSUBISHI MATERIALS CORPORATION
Field: Surface technology, coating (Chemistry)
Classification: CPC C  B | IPC B  C

Claim 0:
1. A copper alloy plate comprising a surface layer part,
wherein in a center in a plate thickness direction more than 2% (% by mass, the same hereafter) and 32.5% or less of Zn as a center Zn concentration; 0.1% or more and 0.9% or less of Sn; 0.05% or more and less than 1.0% of Ni; 0.001% or more and less than 0.1% of Fe, and 0.005% or more and 0.1% or less of P; and the balance Cu with inevitable impurities are contained,
wherein a surface Zn concentration at a surface of the copper alloy plate is 40% or less of the center Zn concentration,
wherein the surface layer part has a depth from the surface to where Zn concentration is 90% of the center Zn concentration; and
wherein in the surface layer part, the Zn concentration increases from the surface toward the center at a concentration gradient of 10% by mass/μm or more and 1000% by mass/μm or less, and the Zn concentration in the surface layer part does not decrease from the surface Zn concentration.