| 摘要 |
<p>In a method of seallig electronic components (see Groups XXXVI and XXXVII) a synthetic resin sealant is used which initially is in the form of a solid block but which on heating liquefies and then solidifies and cures. The preferred form of sealant is prepared by melting an epoxy resin, formed as a reaction product of bisphenol A and epichlorhydrin, and mixing in a filler, e.g. slate powder of 200 mesh, and a curing agent, e.g. phthalic anhydride in the proportions of 100 pts. resin to 50 pts. filler and 30 pts. curing agent. The mixture is then cooled and solidifies. The solid is then powdered and pressed to form the sealant block of the required shape. The resulting block is thermoplastic, liquefying at a temperature of 120 DEG -150 DEG C. before beginning to gel and cure.</p> |
