Abstract: An ink composition is prepared in such a manner that a difference between a dynamic surface tension (mN/m) measured by a maximum bubble pressure method at a temperature of 24 to 26° C. and a static surface tension (mN/m) is within a range from 0 to 7 (mN/m). The ink composition is stored in an ink tank of an ink head, and is supplied from the ink tank to an ink chamber having a discharge port, and a voltage is applied to partitions formed by a piezoelectric material to apply a pressure by the partitions to the ink composition stored in the ink chamber, whereby a liquid droplet of the ink composition is discharged from the discharge port and the liquid droplet is deposited on a recording material to record an image.

Abstract: An object of the present invention is to provide an ink composition having a high permeability as an inkjet ink and permitting high quality image printing even with a high speed. To achieve the above object, the present invention provides an ink composition including: (a) an aqueous medium having a conductivity of 250 ?S/cm (at 25° C.) or lower; (b) a pigment; and (c) a compound represented by the formula (I): wherein m and n each are an integer of 0-11; m+n is an integer of 9-11; x is an integer of 5-9; and y is a number between 2.5-5.

Abstract: An ink composition is prepared by incorporating water, a colorant and a polyester resin in which a polybasic carboxylic acid ingredient contains an aromatic dicarboxylic acid having a metal sulfonate group. The ink composition is stored in an ink tank of an ink head, the ink composition is supplied from the ink tank into an ink chamber having a discharge port, a voltage is applied to partition wall portions formed of a piezoelectric material, a pressure is applied to the ink composition contained in the ink chamber by the partition wall portions and liquid droplets of the ink composition are discharged from the discharge port and deposited on a recording material thereby recording images.

Abstract: An ink composition is manufactured to contain a surfactant having difference d1 (?10??) which is difference between dynamic surface tension (?10) of the solution obtained by making 0.1 wt % solution dissolved in purified water to be measured by using a maximum bubble pressure method at the bubble frequency of 10 Hz at a temperature from 24° C. to 26° C. and static surface tension (?) to be measured at a temperature from 24° C. to 26° C. and which satisfies 0 mN/m?d1?15 mN/m. An image is recorded by applying a voltage to partitions made of a piezoelectric material thereby applying a pressure to the ink composition supplied from an ink tank to an ink chamber of an ink head to discharge a liquid droplet of the ink composition, and depositing the liquid droplet onto a recording material.

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 object of the present invention is to provide an ink composition having a high permeability as an inkjet ink and permitting high quality image printing even with a high speed. To achieve the above object, the present invention provides an ink composition comprising: (a) an aqueous medium having a conductivity of 250 ?S/cm (at 25° C.) or lower; (b) a pigment; and (c) a compound represented by the formula (I): wherein m and n each are an integer of 0-11; m+n is an integer of 9-11; x is an integer of 5-9; and y is a number between 2.5-5.

Abstract: An electrophotographic toner is prepared by using a binder resin having an acid value of 5 to 15 mgKOH/g, a salicylic metal complex, a colorant, and a releasing agent. In the preparation determination for the third root distribution of a light emission voltage by helium atmospheric pressure microwave induction plasmas for carbon atoms derived from the binder resin and metal atoms derived from the salicylic metal complex is made based on a value measured by a micro-particle measuring apparatus including a normal pressure or atmospheric pressure space, a capillary tube inserted at one end in the space, a microwave source, a cavity, a quartz tubular reactor, a discharge means, an analyses means, and a signal detection portion. The absolute deviation showing the scattering of approximate straight lines approximated by a least squares method is controlled to be 0.08 or less.

Abstract: A toner is provided with which the image formed by the use of an image-forming apparatus for electrophotography may keep a good and uniform image density for a long period of time from the initial stage of image formation. The toner contains a toner base particle containing at least a colorant and a binder resin, silica having an average particle size of 40 nm or larger and 200 nm or smaller, and an aluminum oxide-silicon dioxide mixed oxide having an average particle size of 5 nm or larger and 25 nm or smaller. The silica and the aluminum oxide-silicon dioxide mixed oxide are externally added to the toner base particle.

Abstract: The present invention provides ink for inkjet recording containing ethylene glycol base ether and/or monovalent alkyl alcohol, a surfactant and a coloring agent, the ink showing the following characteristics when 2 ?l of the ink is dropped on a piece of ordinary paper having smoothness of 100 sec or lower: a) an initial contact angle is in the range of 30 to 80°; b) a dynamic contact angle after 1 second X=???o (? is a dynamic contact angle after 1 second) according to dynamic absorption measurement is in the range of ?70?X??20 (°/s); and c) the rate of change of a dot area after t second (0.1<t<5(s)) Y=rt2/ro2 (rt is a dot radius after t second) is in the range of 1.5<Y. With this ink, clear images which are less prone to smear are produced even by high speed recording on a piece of ordinary paper.

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 ink composition is manufactured to contain a surfactant having difference d1 (&sgr;10−&ggr;) which is difference between dynamic surface tension (&sgr;10) of the solution obtained by making 0.1 wt % solution dissolved in purified water to be measured by using a maximum bubble pressure method at the bubble frequency of 10 Hz at a temperature from 24° C. to 26° C. and static surface tension (&ggr;) to be measured at a temperature from 24° C. to 26° C. and which satisfies 0 mN/m≦d1≦15 mN/m. An image is recorded by applying a voltage to partitions made of a piezoelectric material thereby applying a pressure to the ink composition supplied from an ink tank to an ink chamber of an ink head to discharge a liquid droplet of the ink composition, and depositing the liquid droplet onto a recording material.

Abstract: An ink composition is prepared in such a manner that a difference between a dynamic surface tension (mN/m) measured by a maximum bubble pressure method at a temperature of 24 to 26° C. and a static surface tension (mN/m) is within a range from 0 to 7 (mN/m). The ink composition is stored in an ink tank of an ink head, and is supplied from the ink tank to an ink chamber having a discharge port, and a voltage is applied to partitions formed by a piezoelectric material to apply a pressure by the partitions to the ink composition stored in the ink chamber, whereby a liquid droplet of the ink composition is discharged from the discharge port and the liquid droplet is deposited on a recording material to record an image.

Abstract: An ink composition is prepared by incorporating water, a colorant and a polyester resin in which a polybasic carboxylic acid ingredient contains an aromatic dicarboxylic acid having a metal sulfonate group. The ink composition is stored in an ink tank of an ink head, the ink composition is supplied from the ink tank into an ink chamber having a discharge port, a voltage is applied to partition wall portions formed of a piezoelectric material, a pressure is applied to the ink composition contained in the ink chamber by the partition wall portions and liquid droplets of the ink composition are discharged from the discharge port and deposited on a recording material thereby recording images.

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: The present invention provides ink for inkjet recording containing ethylene glycol base ether and/or monovalent alkyl alcohol, a surfactant and a coloring agent, the ink showing the following characteristics when 2 &mgr;l of the ink is dropped on a piece of ordinary paper having smoothness of 100 sec or lower:

Abstract: The present invention relates to an electrophotosensitive material wherein a layer containing a binder resin and a pigment among a photosensitive layer is formed by applying and drying a coating solution prepared by dispersing the binder resin and the pigment in a dispersion medium containing alcohol represented by the formula (1): wherein R1, R2 and R3 are the same or different and represent a hydrogen atom or an alkyl group; the electrophotosensitive material is free from lowering of the sensitivity due to formation of agglomerates of the pigment and is superior in sensitivity characteristics.

Abstract: The present invention relates to an electrophotosensitive material wherein a layer containing a binder resin and a pigment among a photosensitive layer is formed by applying and drying a coating solution prepared by dispersing the binder resin and the pigment in a dispersion medium containing alcohol represented by the formula (1): 1

Abstract: An ink jet printing apparatus includes a sheet transporting mechanism for transporting a printing sheet along a vertical plane; a first printing head unit provided on a horizontal plane perpendicularly intersecting the vertical plane and having an ink emission portion for emitting ink to one side surface of the printing sheet; and a second printing head unit provided on a horizontal plane perpendicularly intersecting the vertical plane and having an ink emission portion for emitting ink to the other side surface of the printing sheet.