| 摘要 |
PROBLEM TO BE SOLVED: To improve applicability to a separating process at the time of recovery of synthetic resin, by setting a breaking strength of a thermosensible sheet at a specific value or below. SOLUTION: A substrate of synthetic resin having a breaking strength of 6kg/cm or less is used for a thermosensitive sheet and the thickness of the substrate is made 10-1000μm, preferably about 30-300μm. Although polyethylene, polypropylene, polystyrene, polyester, etc., can be cited as a synthetic resin material of the substrate, the polystyrene of which the breaking strength is low relatively is preferable. As to foamed polystyrene, a styrene copolymer constituted mainly of styrene, e.g. shock-resistant polystyrene, and others can be mentioned in addition to a single polymer of styrene. Besides, a void containing material, particularly the material of which the void ratio is 30-85%, preferably 50-75%, is used for the substrate. A thermosensitive layer forming material, an intermediate layer forming material, a protective layer forming material and/or a back coat layer forming material are applied as a water solution or an aqueous emulsion on a sheet base material. |
