PURPOSE: To obtain a colloidal solution capable of being formed into a coated film with a given thickness, having a low content of remaining solvent even by using no high-boiling solvent, by dissolving a polyfunctional maleimide in a thermosetting resin under heating or after preliminary reaction, followed by blending it with a specific low- boiling solvent.
CONSTITUTION: 5W90wt% polyfunctional maleimide is dissolved in 10W95wt% thermosetting resin under heating or after they are reacted preliminarily, the resin composition is dissolved in the thermosetting resin, and the solution is blended with a low-boiling solvent (e.g., acetone, benzene, methanol, etc.) having a boiling point of ≤150°C which is a poor solvent to the polyfunctional maleimide so that the blend is made in a colloidal state. After the blend is made into a colloidal state, the blend is mixed with a solution of the thermosetting resin or a solution of its pre-reacted product in the low- boiling solvent. In the blending with the solvent, dissolution under heating may be carried out or the pre-reacted product at high temperature immediately after the reaction may be added to the solvent while being cooled with stirring or after cooled it may be added to the solvent. The prepared colloidal solution can be handled in the same way as a common completely dissolved varnish solution of a thermosetting resin is treated.
IKEGUCHI NOBUYUKI
KANEHARA HIDENORI
| JPS5655449A | 1981-05-16 |