| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a hard vinyl chloride resin pipe which is difficult to be bent or has little bend even when irradiated with solar beams or the like. <P>SOLUTION: The maximum temperature on a surface of the hard vinyl chloride resin pipe is≤60°C when the hard vinyl chloride resin pipe is irradiated with the infrared rays and far-infrared rays of the wavelength of 0.7-100μm and the calorie of 4 kw/m<SP>2</SP>for two hours under the atmosphere of the outside temperature of 15°C, and the differenceΔσbetween the maximum value and the minimum value of the circumferential stressσcalculated from a formula (1) is≤2.94 MPa when naturally exposed under the environment of the solar radiation of≥3,500 kcal/m<SP>2</SP>.day. <P>COPYRIGHT: (C)2004,JPO</p> |
