COLORED RESIN COMPOSITION HAVING RESISTANCE TO CHLORINE-CONTAINING WATER, WATER PIPE, AND METHOD FOR IMPROVING RESISTANCE OF MOLDING TO CHLORINE-CONTAINING WATER

摘要

PROBLEM TO BE SOLVED: To obtain a composition which can give pipes having excellent resistance to chlorine-containing water by including a specified amount of a polyolefin resin with an inorganic pigment treated with a silane coupling agent. SOLUTION: Usually, the polyolefin used is a high-density polyethylene in applications to large-diameter water pipes and is a linear low-density polyethylene in applications to small-diameter water pipes. The silane coupling agent used is desirably methoxysilane, methacrylsilane, or epoxysilane, and, usually, it is used in an amount of 0.05-3.0 wt.%. Water pipes can be prepared by directly molding the colored pellets containing an inorganic pigment treated with a silane coupling agent or by diluting a masterbatch containing a high concentration of an inorganic pigment with a polyolefin and molding the mixture. The compounding ratio is such that 0.01-10 pts.wt. inorganic pigment treated with a silane coupling agent is added to 100 pts.wt. polyolefin.