Abstract: An object of the invention is to form a recorded image having an excellent sharpness, high image density, and a prominently favorable image quality without generation of blur, offset, and the like when a high speed printing is carried out in an ink jet recording method. An ink contains colorant, water-soluble organic solvent, and water as essential components. By selecting the contents of essential components and the kind and content of a given component, an ink for ink jet recording is prepared having an initial dynamic contact angle (?0) of 48° or more, and a variation (??/100 msec) of a dynamic contact angle for a duration of 100 msec after drop of 2.0° or more and 20.0° or less, with respect to a recording medium coated with an auxiliary fluid containing cationic resin and/or inorganic microparticles. By using the ink, an image is recorded on a plain paper coated with auxiliary fluid.

Abstract: An image recording apparatus based on a color ink-jet scheme provided with an ink set consisting of one or more than one colors of inks and a black ink and an ink-jet printing unit, wherein the initial contact angles &thgr;0 of two colors of inks, namely, a color ink and a black ink, fall within the range from 30 to 80°, the contact angle variation Xa of the ink A as obtained by the dynamic liquid absorption measurement after the elapsed time of 1 second falls within the range −70<Xa<−10(°), the dot area ratio Ya of the ink A after the elapsed time of ta seconds-falls in the range 1.5<Ya, the contact angle variation Xb of the ink B as obtained by the dynamic liquid absorption measurement after the elapsed time of 1 second falls within the range −15<Xb<0(°), and the dot area ratio Yb of the ink B after the elapsed time of tb seconds falls within the range 1.0<Yb<1.7, where printing is made first with the ink A and subsequently with the ink B.

Abstract: An ink for use in the ink-jet recording comprising a dye and/or a pigment and water as the indispensable components and a water-insoluble solid content of 1% or more of the whole quantity, the ink further comprising: a nonionic surfactant having polyethylene oxide groups and polypropylene oxide groups, which is a substance having the structure shown by the following structural formula 1; and a number x of the added polyethylene oxide groups and a number y of the added polypropylene oxide groups satisfy the relation that 0<x≦10, and the relation that x/2−1<y<x/3+2, where q and r are respectively the numbers of the methylene groups, and satisfy the relation that 9≦q+r≦11.

Abstract: An image recording apparatus based on a color ink-jet scheme provided with an ink set consisting of one or more than one colors of inks and a black ink and an ink-jet printing unit, wherein the initial contact angles &thgr;0 of two colors of inks, namely, a color ink and a black ink, fall within the range from 30 to 80°, the contact angle variation Xa of the ink A as obtained by the dynamic liquid absorption measurement after the elapsed time of 1 second falls within the range −70<Xa<−10(°), the dot area ratio Ya of the ink A after the elapsed time of ta seconds-falls in the range 1.5<Ya, the contact angle variation Xb of the ink B as obtained by the dynamic liquid absorption measurement after the elapsed time of 1 second falls within the range −15<Xb<0(°), and the dot area ratio Yb of the ink B after the elapsed time of tb seconds falls within the range 1.0<Yb<1.7, where printing is made first with the ink A and subsequently with the ink B.

Abstract: An ink for use in the ink-jet recording comprising a dye and/or a pigment and water as the indispensable components and a water-insoluble solid content of 1% or more of the whole quantity, the ink further comprising: a nonionic surfactant having polyethylene oxide groups and polypropylene oxide groups, which is a substance having the structure shown by the following structural formula 1; and a number x of the added polyethylene oxide groups and a number y of the added polypropylene oxide groups satisfy the relation that

Abstract: A stamp includes an ink supply member capable of exchangeably affixing an engraved thermal stencil paper which is engraved by means of a thermal head, and a stamp holder wherein the engraved thermal stencil paper attached to the ink supply member is received so as to oppose the stamping opening. The thermal stencil paper is constructed by layering a film which melts with heat and a porous supporting member. The ink supply member is constructed by impregnating an open-pored microporous structure with ink having a viscosity of 1,000 to 100,000 CPS and 2.5 or less on the Thixotropy Index. The thermal stencil paper, along with a transport-assistant tape to reinforce the thermal stencil paper, are rolled onto a core in a double layer.

Abstract: A stamp cassette includes a thermal stencil paper and a transport-assistant tape housed in a stamp cassette housing. The thermal stencil paper and the transport-assistant tape are wound together in two layers about a core in the stamp cassette housing.