Pillsbury Madison & Sutro LLP
Emulsion ink for stencil printing
 Provided is a water-in-oil (W/O) emulsion ink for stencil printing which is less in change of viscosity with time and can give always stable prints. The emulsion ink contains a resinous component having a free carboxylic acid group or a higher fatty acid in the oil phase, and contains a divalent or trivalent metal salt and a monovalent metal salt having alkalinity in the water phase, whereby an interfacial layer of the emulsion is strengthened to stabilize the emulsion. The resinous component is preferably an alkyd resin, a rosin-modified phenolic resin, a maleic acid resin and a rosin. The monovalent metal salt or the divalent or trivalent metal salt is preferably contained in at least an amount equivalent to the free carboxylic acid of the resinous component and the higher fatty acid contained in the oil phase. The resinous component or the higher fatty acid is contained in an amount of 0.5-30% by weight based on the total amount of the emulsion ink. 
Riso Kagaku Corporation
C
C09D
inventional
Hiromichi Sadanao
Yamada Okuda