| 摘要 |
PURPOSE:To permit foaming of an organic foaming agent with heat, thereby breaking capsules and releasing a curing agent by covering a core material comprising the foaming agent and the curing agent with a hard wall material comprising a thermoplastic resin to form the capsules. CONSTITUTION:A core material (A) is prepared by blending 1 pt.wt. organic foaming agent having a softening point higher than that of the following wall material (e.g. azodicarbonamide), 1-100 pts.wt. curing agent (e.g. 2- undecylimidazole) and, if necessary, auxiliaries, curing accelerator, etc. Then, microcapsules with an average particles size of 100mum or less are provided by covering 1 pt.wt. component A with 0.01-10 pts.wt. wall material comprising a thermoplastic resin having a softening point of 70-200 deg.C (e.g. PS). The above microcapsules are blended with an epoxy, urethane or polysulfide resin to form an adhesive composition. |
