| 摘要 |
PURPOSE:To decrease concn. of unreacted residual formaldehyde and to provide heat resistance by forming a wall film with a melamine resin having a specified value of the molar ratio of reaction of an initial stage condensate of melamine to formaldehyde and coating the surface of the wall film with a heat-resistant layer consisting of a heat-resistant fine particle and a silicone oil. CONSTITUTION:In forming a microcapsule wherein a melamine resin is used as a wall film, when the initial stage condensate of the melamine and formaldehyde is formed, the molar ratio of these reaction components is adjusted to 1:2.5 to 1:3.5 from approximately 1:4 of the conventional case. The concn. of residual formaline in the microcapsule dispersion or powder is decreased thereby. In addition, the surface of the wall film of this microcapsule is coated with a heat-resistant layer formed of a heat-resistant fine particle and a silicone oil. Density and durability being substantially the same level as those for the convential one can be assured thereby without spoiling any function of this microcapsule and additionally heat resistance can be provided to this microcapsule. |
