| 摘要 |
PURPOSE:To obtain a cated metallic pipe of superior water resistance by applying a chromic acid or phosphoric acid type chemical conversion coating on a metallic pipe as a pretreatment thence coating an epoxy resin, a polyolefin type adhesive material and a polyethylene resin successively thereon. CONSTITUTION:After a blank metallic pipe is descaled and cleaned, it is applied with, for example, a coating type chromate coating (about 45-75% Cr<6+>, about 55-25% Cr<3+>, and about 25-500mg/m<2> total coverage) or a reaction type zinc phosphate coating (about 0.3-5g/m<2> coverage) or a reaction type lead phosphate coating (about 0.2-0.5g/m<2> coverage). Thence, epoxy or its modified deriv. resin is coated at about 1-60mu thickness thereon and is allowed to set. Further, a polyolefin type adhesive material, for example, a maleic anhydride copoylmer of polyethylene is applied thereon, and a polyethylene resin of low or medium density is coated as an outside surface coating material thereon. |
