| 摘要 |
PURPOSE:To provide low hazardousness further with temperature control capable by forming a reversible temperature sensing discoloring pattern layer with 40 deg.C or more discoloring temperature in a surface of placing an induction heated object, and forming a transparent heat insulating layer on this surface. CONSTITUTION:A plate consisting of silicon nitride is used as an induction heating cooking device upper plate 1, and a plate of composition 1 is used in a surface of the cooking device upper plate 1, to form the first blue color temperature sensing discoloring pattern layer 2 at an ordinary temperature by screen printing. Ink of composition 2 is used on the discoloring pattern layer 2, to form the yellow color second temperature sensing discoloring pattern layer 2 at an ordinary temperature dried. Next by using ink of composition 3 so as to cover each pattern layer 2, a foaming ink layer is formed by a spray coat method. This foaming ink layer is dried, hardening and foaming, to obtain a transparent heat insulating layer 3, and the cooking device upper plate 1, having a green color temperature sensing discoloring pattern at an ordinary temperature, is completed. Then by visually recognizing a change of color of the pattern layer 2, a surface temperature of the cooking device upper plate 1 can be grasped for whether or not its surface temperature is 40 deg.C or more. |
