| 摘要 |
PURPOSE:To enhance the heat resistance including solder bath resistance of a molded product, by applying heat-treatment to the molded product composed of a substantially amorphous thermotropic liquid crystal like polyester to crystallize said product and making the m.p. thereof higher than a glass transition point by specific temp. or more. CONSTITUTION:A molded product composed of a substantially amorphous thermotropic liquid crystal like polyester is heat-treated to be crystallized and the m.p. thereof is made higher than a glass transition point by 50 deg.C or more. The heat treatment of the molded product is started from temp. not exceeding the glass transition point of polyester, usually, from temp. lower than the glass transition point by about 20 deg.C and the temp. thereof is gradually raised at a speed not deforming the molded product, usually, at a speed of about 4 deg.C/hr to crystallize said product to allow the m.p. thereof to appear. It is necessary to perform heat treatment until the m.p. becomes higher than the glass transition point by 50 deg.C or more. When the difference between the m.p. and the glass transition point is below 50 deg.C, the effect of crystallization is not developed substantially and heat resistance including solder bath resistance is not almost improved. |
