PRESSURE-SENSITIVE COPYING SHEET

PURPOSE:To obtain a pressure-sensitive copying sheet with a microcapsule coating liquid and a color developer applied uniformly and an improved coloring ability due to a sheet support having a specified oil resistance and an improved ability to capture dye by adding a specific synthetic size agent to the sheet support. CONSTITUTION:A synthetic size agent used selectively on a sheet support consists of a copolymer produced by durning a reaction product based on amino containing at least, one amino group and a monomer with a C8 to 30 hydropho bic group to an epoxy resin, on a sheet support. In addition, a synthertic size agent has a permeation rate of 35mm or less. The permeation rate is obtained by soaking a No.2 filter paper with a basis weight of 120g/m in a diluted size agent for one minute, thenallowing the end of a long strip of the is paper (15mm X 130mm) to stand upright in diisopropylnaphthalene after drying it at 105 deg.C using a hot blast dryer, and measuring a permeation length after the lapse of 30min. This synthetic size agent is highly water-repellent and the sheet support to which an appropriate amount of the agent is applied has an uniformly formed color developer layer or capsule layer.