PURPOSE: To obtain an element that is excellent in heat resisting, moisture resisting and heat shock resisting properties, by using a resin prepared through heating and curing a composition consisting of less than 60 weight % triaryl cyanurate and not less than 40 weight % 1,4-polybutadiene cyclic compound as a top coat.
CONSTITUTION: The heat resisting properties of a cured film increase in proportional to the augmentation of the content of triaryl cyanurate in a mixed composition of a 1,4-polybutadiene cyclic compound and triaryl cyanurate. Time up to the formation of cracks in the case when the cured film with 40μ thickness applied onto a glass plate is exposed in air with 150°C temperature is shown in the diagram, unevenness on a surface of the cured film becomes intense and pinholes and cracks are produced when the content of triarly cyanurate is not less than 60 weight %, and mixing effect is little when the content is not more than 10 weight %. Thus, the device with high heat shock resisting properties can be gained when a composition consisting of less than 60 weight % triarly cyanurate and not less than 40 weight % the polybutadiene cyclic compound is dissolved in an organic solvent, applied to a portion to be protected, dried and preferably heated and cured at 180°C.
NAGAI YUUJI
TAKEDA SHIROU
