| 摘要 |
PURPOSE:An adhesive layer of hot-melt substance with specific physical properties is provided on the outer surface of pipes of heat-expanding synthetic resin to use as the laminate tube for lining, thereby preventing the formation of bubbles when inserted into the inside of metal pipes causing uneveness in expansion on heating. CONSTITUTION:A hot-melt adhesive layer having an apparent melt viscosity of over 3X10<4> poise at an apparent shear rate of 10 sec<-1>, which is measured at 130 deg.C by using a nozzle of 1 mm inner diameter and 10 mm total length in Koka Flow Tester and a temperature at which the flow of the polymer starts of lower than 110 deg.C, which is measured by using a nozzle of 1 mm inner diameter and 2 mm total length at a rate of temperature rising of 3 deg.C/min, is provided on the outer surface of a heat-expanding synthetic resin pipe by laying a good adhering intermediate layer of preferably an ethylene-vinyl acetate copolymer. The resulting pipe is inserted into a metal pipe and heated to expand and adhere to the metal pipe. |
