| 摘要 |
PURPOSE:To form a silane crosslinked polyethylene film excellent in hot water resistance to the inner surface of a steel pipe, by a method wherein special polyethylene with a specific hot melt index is applied to the inner surface of the steel pipe and succeedingly crosslinked. CONSTITUTION:The inner surface of a heated steel pipe is coated with a polymer which is at least one of a silane grafted polyethylene powder or a silane copolymerized polyethylene powder obtained by copolymerizing the main chain of polyethylene with silane such as vinyltriexthoxysilane and of which the melt index is 2-10. In the next step, a thermal crosslinking catalyst such as zinc stearate or dibutyl tin laurate is used in an amount of 0.1-0.01wt% on the basis of the above mentioned polyethylene to subject the film to silane-crosslinking. By this method, a film reduced in blister generation and having hot water resistance and good adhesiveness is obtained. |
