1. Chemical properties of copper alloy

　　Copper alloy materials will react chemically when they meet acidity, alkalinity, oxidizing agents or reducing agents, and will easily change color. When the chemical residue on the clothing reacts with the teeth, sliders, and tail parts of the metal zipper, the zipper may change color. This chemical reaction is more likely to occur under high temperature and high humidity conditions. (The clothes are steam ironed, or sealed in plastic bags, and kept for a long time, etc.). This situation does not belong to the quality of the zipper.

 

　　 2. Examples of discoloration due to chemical reaction

 

　　 1. Steam ironing or rainy weather → blue [Cu(OH)2]

 

　　 2.. Acidic compounds and chromium compounds [Cr2O3] → black [CuO, red [CuO2] or blue [CuSO4]

 

　　 3. Conditions for excess Cl2 gas → light yellow [CuCl2]

 

　　 4. Oxidizing bleach [H2O2] → black [CuO] or red [CuO2]

 

　　 5 Reduced bleach [Na2SO3] → black [CuO, CuS] or red [CuO2]

 

　　 6. Conditions for excess of sulfide or HS2 gas → black [CuS]