Shanghai Liangren Chemical Co., Ltd. (Simple "LR")was founded in 1987. We are a professional manufacturer and leading wholesale of metal sulface treatment chemicals, and our main products are chromium salts, nickel salts, copper salts, cobaltous salts, other salts , more products will update. LR is BV vertified supplier .We always supply high quality products to all customers,and bulit trust business relationship with them for a long time.We have a strict rule for the production according to ...