| 摘要 |
PURPOSE:To obtain a recording sheet less susceptible to contamination due to undesired color development under pressure and having excellent printability and handleability, by incorporating an alkali salt of a methacrylic acid copolymer into a coated layer. CONSTITUTION:An alkali salt of a methacrylic acid copolymer is incorporated in a coated layer comprising microcapsules having a synthetic high molecular weight wall film and enclosing a color developer therein. The salt is an alkali salt of a copolymer of methacrylic acid with at least one monomer copolymerizable therewith. The copolymerizable monomer is preferably an alkyl methacrylate having an up to 18C alkyl, acrylamide, acrylonitrile, styrenesulfonic acid or 2-acrylamide-2-methylpropanesulfonic acid. When the content of methacrylic acid is less than 8mol%, sufficient water solubility can not obtained, whereas when the content is more than 90mol%, there is a possibility that property for re-dissolution through absorbing moisture of the copolymer is increased. Therefore, it is preferable to use methacrylic acid in an amount of 8-90mol% based on the copolymer. |
