| 摘要 |
PROBLEM TO BE SOLVED: To provide a new sheet heating element provided with both a superior PTC characteristic and low initial electric resistance, having an excellent heat generation function without causing a local overheat, excellent flexibility and high shape stability, and thin in thickness. SOLUTION: This PTC sheet heating element is composed by sequentially overlaying a soaking sheet on one surface or both surfaces of a planar heat generation sheet formed by impregnating or applying a PTC conductive composition comprising carbon black or graphite, paraffin and a thermoplastic elastomer into/to a fabric cloth, and an insulating film on its both surfaces, and satisfies following conditions: (1) thickness is 0.6-1.2 mm; (2) D<SB>25</SB>is 250-500 W/m<SP>2</SP>; (3) D<SB>25</SB>/D<SB>45</SB>is below 1.5; and (4) D<SB>45</SB>/D<SB>80</SB>is above 7. D<SB>25</SB>, D<SB>45</SB>and D<SB>80</SB>are power density at 25°C°, 45°C and 80°C, respectively. COPYRIGHT: (C)2005,JPO&NCIPI
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