Pressure sensitive copying paper
AssigneeMitsubishi Paper Mills Limited
InventorsTakao Kosaka, Mamoru Ishiguro, Hideaki Senoh
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Abstract
A pressure sensitive copying paper comprising a sheet having on a support a coating layer containing finely divided cellulose powder (a) and mononucelus microcapsules (b) containing an oil solution of an electron donative colorless or light-colored dye, using an amino resin as film material and having a volume-average particle diameter of 5-10 microns (.mu.m) and a film thickness of 0.08-0.3 microns (.mu.m); and a sheet having on a support a coating layer containing an electron acceptant solid-state acid material which is reacted on contact with the dye to form a color. This pressure sensitive copying paper has the advantages such as excellent color forming performance, proofness against smudging, long-time storage stability, etc.
Claims2
A pressure sensitive copying paper comprising a sheet having on a support a coating layer containing finely divided cellulose powder (a) and microcapsules of mononucleus (b) containing an oily solution of an electron donative colorless or light-colored dye, using an amino resin as film material and having a volume-average particle diameter of 5-10 microns (.mu.m) and a film thickness of 0.08-0.30 microns (.mu.m) as calculated from the formula (1):
- ##EQU6## (wherein D is average particle size (diameter, .mu.m) of microcapsules, R is the amount (weight parts) of core material used, M is the amount (weight parts) of amino compound used as wall film material, n is the molar ratio of formaldehyde used (molecular weight m.sub.2) to amino compound (molecular weight m.sub.1), and m.sub.3 is molecular weight of water);
- and a sheet having on a support a coating layer containing an electron acceptant solid-state acid material which is reacted on contact with said dye to form a color.
Dependencies are inferred from the claim text.