Abstract: A method for producing a high-quality and low-cost laminate type electrophotographic photoreceptor having a coating film of uniform thickness with high efficiency is provided. In the electrophotographic photoreceptor having a laminated structure composed at least of two layers: a charge generating layer containing a charge generating substance and a charge transporting layer containing a charge transporting substance, the charge generating layer is formed by applying a coating solution for forming the charge generating layer onto the conductive support by an ink-jet coating method, and the charge transporting layer is formed by applying a coating solution for forming the charge transporting layer onto the charge generating layer by a roll coating method.

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: A coating composition for an electrophotographic photoreceptor that forms a charge-generating layer by being ejected from ejection nozzles in a form of droplets, comprises a charge-generating substance, a binding resin, and a solvent, has a viscosity of 1 mPa·s to 10 mPa·s, and the solvent contains at least one kind of high-boiling point solvent having a boiling point of 120° C. to 260° C., and the high-boiling point solvent is contained at a ratio of 5 parts by weight to 40 parts by weight with respect to 100 parts by weight of the coating composition for an electrophotographic photoreceptor.

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 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: A method for producing a high-quality and low-cost laminate type electrophotographic photoreceptor having a coating film of uniform thickness with high efficiency is provided. In the electrophotographic photoreceptor having a laminated structure composed at least of two layers: a charge generating layer containing a charge generating substance and a charge transporting layer containing a charge transporting substance, the charge generating layer is formed by applying a coating solution for forming the charge generating layer onto the conductive supportby an ink-jet coating method, and the charge transporting layer is formed by applying a coating solution for forming the charge transporting layer onto the charge generating layer by a roll coating method.

Abstract: A coating composition for an electrophotographic photoreceptor that forms a charge-generating layer by being ejected from ejection nozzles in a form of droplets, comprises a charge-generating substance, a binding resin, and a solvent, has a viscosity of 1 mPa·s to 10 mPa·s, and the solvent contains at least one kind of high-boiling point solvent having a boiling point of 120° C. to 260° C., and the high-boiling point solvent is contained at a ratio of 5 parts by weight to 40 parts by weight with respect to 100 parts by weight of the coating composition for an electrophotographic photoreceptor.

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: