| 摘要 |
PURPOSE:To obtain a vinyl chloride resin pipe not eluting lead by mixing a composite petal soap type and/or organotin type stabilizer containing no lead with a vinyl chloride type polymer containing partially saponified polyvinyl alcohol PVAA, partially saponified polyvinyl alcohol PVAB, a secondary dispersant and water-soluble cellulose ester as dispersants for suspension polymerization and molding the resulting mixture. CONSTITUTION:A vinyl chloride resin pipe is obtained by a vinyl chloride polymer (PVC) obtained by the suspension polymerization of a mixture (vinyl chloride type monomer mixture) of vinyl chloride and a monomer copolymerizable with vinyl chloride in an aqueous medium. PVC is produced using PVAA with a saponification degree of 70-90mol% and an average polymerization degree of 1500-3000, PVAB with a saponification degree of 70-90mol% and an average polymerization degree of 300-1000, a secondary dispersant whose amt. is 0-2.0 pts.wt. with respect to 100 pts.wt. of the vinyl chloride monomer and water-soluble cellulose ester whose amt. of 0-0.5 pts.wt. with respect to 100 pts.wt. of the vinyl chloride monomer as dispersion stabilizers for suspension polymerization. A composite metal soap type and/or metal tin type stabilizer containing no lead is mixed with the dispersion stabilizers. |
