JP2009202515A - Recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording device that achieves both a high transferring efficiency to a recording medium and a high image preservative property. <P>SOLUTION: After a first layer 17A of large ink acceptable particle 16A having a higher softening temperature than an ink acceptable particle 16B is formed on an intermediate transferring unit 12, the ink acceptable particle 16B having a lower softening temperature than the ink acceptable particle 16A is supplied to be laminated on the first layer 17A of the ink acceptable particle 16A. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a recording apparatus.

  There is an ink jet recording method in which an image or data using ink is recorded. The principle of the ink jet recording system is to record on paper, cloth, film, etc. by discharging liquid or molten solid ink from a nozzle, slit, porous film or the like. As for the method of ejecting ink, so-called charge control system that ejects ink using electrostatic attraction force, so-called pressure pulse system that ejects ink using the vibration pressure of piezo elements, and bubbles are formed by high heat. Various methods such as a so-called thermal ink jet method, in which ink is ejected using pressure generated by growth, have been proposed. By these methods, extremely high-definition images and recorded data can be obtained. it can.

  In order to record with high image quality on various recording media such as penetrating media and non-penetrating media, recording methods using ink, including this ink jet recording method, are recorded on an intermediate and then transferred to the recording medium. A scheme has been proposed.

  For example, Patent Document 1 proposes a method for recording while supplying a plurality of types of powder mixtures onto an intermediate, such as polymers having different water absorption, water absorbing polymers having different sizes, and water absorbing polymers having different crosslinking degrees. Yes.

  Patent Document 2 proposes a method of recording while supplying solid particles (particles of polysaccharide polymer, alginic acid, carrageenan, etc.) that thicken the ink by contact with the ink on the intermediate.

  Further, in Patent Document 3, a hydrophobic resin particle layer is formed on an intermediate, and ink (for example, an SD type dye ink (Slow Dry type)) is held in a gap in the hydrophobic resin particle layer on a recording medium. A transfer method has been proposed.

  Patent Document 4 proposes a method in which a gap type ink absorption layer in which inorganic particles, a hydrophilic polymer, and the like are wet-coated is provided on an intermediate body (sheet), and dye ink is ejected thereon and transferred to a recording medium. Has been.

  Patent Document 5 discloses a porous ink absorbing layer formed by drying at a temperature not higher than the minimum film-forming temperature (MFT) of thermoplastic resin particles, which contains thermoplastic resin particles and non-thermoplastic particles. Inkjet intermediate transfer media having been proposed.

On the other hand, in Patent Document 6, the same kind of water-absorbing powder is applied onto the intermediate transfer member in two steps by the first application means and the second application means, thereby providing one application means. There has been proposed a system in which powder that cannot be replenished by coating by the second coating means is replenished.
JP 2000-343808 A JP 2000-94654 A JP 2003-57967 A JP 2002-370347 A JP 2002-321443 A JP 2006-137120 A

  In transferring particles from an intermediate transfer member to a recording medium, high transfer efficiency is required. However, if transfer efficiency is pursued, blocking resistance, heat resistance, and abrasion resistance of particles after being transferred to a recording medium are required. However, when the image storage stability is pursued, the transfer efficiency may be deteriorated.

  An object of the present invention is to provide a recording apparatus capable of realizing both high transfer efficiency to a recording medium and high image storage stability.

  The above problem is solved by the following means. That is,

  According to the first aspect of the present invention, an intermediate transfer member and a plurality of types of ink receptive particles that receive ink and have different softening temperatures are laminated in layers on the intermediate transfer member for each type of ink receptive particles. So that the softening temperature of the ink receiving particles of the first layer closest to the intermediate transfer member is higher than the softening temperature of the ink receiving particles of the second layer farthest from the intermediate transfer member. Ink droplets for ejecting ink droplets toward the particle laminate of the plurality of types of ink receiving particles supplied onto the intermediate transfer body by the supplying unit, the supply unit supplying the plurality of types of ink receiving particles. A recording apparatus comprising: an ejection unit; a transfer unit that transfers the particle stack to a recording medium; and a fixing unit that fixes the particle stack transferred to the recording medium to the recording medium. It is a position.

  According to a second aspect of the present invention, in the supply means, a layer of ink receiving particles having a low softening temperature is laminated on the intermediate transfer member from the first layer side toward the second layer side. The recording apparatus according to claim 1, wherein the ink receiving particles are supplied as described above.

  According to a third aspect of the present invention, the supply means supplies a plurality of particles that are arranged along the moving direction of the intermediate transfer member and supply ink receiving particles having different softening temperatures to the intermediate transfer member in layers. And at least the most upstream particle supply means in the moving direction of the intermediate transfer member has a softening temperature higher than that of the ink receiving particles supplied by the most downstream particle supply means. High ink-receptive particles are supplied to the intermediate transfer member in a layered manner to form the first layer, and at least the most downstream particle supply in the moving direction of the intermediate transfer member among the plurality of particle supply means The means supplies the ink receptive particles having a lower temperature than the softening temperature of the ink receptive particles supplied by the supply means on the most upstream side of the intermediate transfer member to form the second layer. Claims A recording apparatus according to claim 1 or claim 2.

  The invention according to claim 4 is characterized in that the supply amount per unit area of the ink receiving particles in the first layer is smaller than the supply amount per unit area of the ink receiving particles in the second layer. The recording apparatus according to any one of claims 1 to 3.

  According to a fifth aspect of the present invention, an intermediate transfer member and a plurality of types of ink receiving particles that receive ink and have different neutralization levels are laminated in layers on the intermediate transfer member for each type of ink receiving particles. The neutralization degree of the ink receiving particles of the first layer closest to the intermediate transfer member is lower than the neutralization degree of the ink receiving particles of the second layer farthest from the intermediate transfer member. The supply means for supplying the plurality of types of ink receiving particles and the ink droplets are ejected toward the particle stack of the plurality of types of ink receiving particles supplied onto the intermediate transfer member by the supply means. Recording means comprising: ink droplet ejection means for transferring; transfer means for transferring the particle stack to a recording medium; and fixing means for fixing the particle stack transferred to the recording medium to the recording medium. Equipment The

  According to a sixth aspect of the present invention, the supply means includes a layer of ink-receptive particles having a high degree of neutralization from the first layer side toward the second layer side on the intermediate transfer member. The recording apparatus according to claim 5, wherein the ink receiving particles are supplied.

  According to a seventh aspect of the present invention, the supply means includes a plurality of particles that are arranged along the moving direction of the intermediate transfer body and supply ink-receptive particles having different neutralization degrees to the intermediate transfer body in layers. Including at least one of the plurality of particle supply means, wherein at least the most upstream particle supply means in the moving direction of the intermediate transfer member is more neutralized than the ink receiving particles supplied by the most downstream particle supply means Ink receiving particles having a low degree are supplied in a layer form to the intermediate transfer member to form the first layer, and at least the most downstream of the plurality of particle supply means in the moving direction of the intermediate transfer member. The particle supplying means supplies the ink receiving particles having a higher degree of neutralization of the ink receiving particles supplied by the supplying means on the most upstream side of the intermediate transfer member in a layered manner to form the second layer. Claim 5 or Is a recording apparatus according to claim 6.

  The invention according to claim 8 is characterized in that the supply amount per unit area of the ink receiving particles in the first layer is smaller than the supply amount per unit area of the ink receiving particles in the second layer. The recording apparatus according to any one of claims 5 to 7.

  According to the first aspect of the present invention, there is an effect that both high transfer efficiency to the recording medium and high image storage stability are realized as compared with the case where this configuration is not provided.

  According to the invention concerning Claim 2, there exists an effect that both further transfer efficiency and high image preservation nature are realized.

  According to the third aspect of the present invention, there is an effect that both high transfer efficiency to the recording medium and high image storability are realized with a simple configuration.

  According to the invention which concerns on Claim 4, there exists an effect that the improvement of the thermal efficiency at the time of fixing can further be aimed at.

  According to the fifth aspect of the present invention, there is an effect that both high transfer efficiency to the recording medium and high image storability are realized as compared with the case where this configuration is not provided.

  According to the invention which concerns on Claim 6, there exists an effect that both further transfer efficiency and high image preservability are implement | achieved.

  According to the seventh aspect of the present invention, there is an effect that both high transfer efficiency to the recording medium and high image storability are realized with a simple configuration.

  According to the eighth aspect of the invention, it is possible to further improve the thermal efficiency during fixing.

(First embodiment)
Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is provided to the member which has the substantially the same effect | action and function through all the drawings, and the overlapping description may be abbreviate | omitted. In the following embodiment, a case is described in which primary particles (detailed later) are applied as ink receiving particles described later.

  As shown in FIGS. 1 and 2, the recording apparatus 10 according to the present embodiment includes an endless belt-like intermediate transfer body 12. The intermediate transfer body 12 is provided so as to move in the moving direction (the arrow A direction in FIG. 1). In the vicinity of the intermediate transfer body 12, a release agent supply device 14 for supplying a release agent 14A onto the intermediate transfer body 12 and the surface of the intermediate transfer body 12 are charged in order along the moving direction of the intermediate transfer body 12. A plurality of types of ink receptive particles 16 that receive ink and have different softening temperatures are supplied to the charged region on the charging device 28 and the intermediate transfer body 12 in a layered manner. The particle supply device 18 that forms the particle stack 40 on the transfer body 12, the inkjet recording head 20 that discharges ink droplets onto the particle stack 40, and the recording medium 8 are superposed on the intermediate transfer body 12 to apply pressure or pressure and heat. The transfer device 22 for transferring the particle stack 40 onto the recording medium 8 and the cleaning device 24 are arranged in order. The recording apparatus 10 includes a fixing device 25 that fixes the particle stack 40 to the recording medium 8 by applying pressure and heat to the particle stack 40.

The intermediate transfer body 12 is provided so as to move in the moving direction (the direction of arrow A in FIG. 1), and is supplied with ink receiving particles 16. In the present embodiment, the intermediate transfer body 12 is described as having a belt shape. However, the intermediate transfer body 12 is not limited to a belt shape, and may be a cylindrical shape (drum shape). The intermediate transfer body 12 holds the ink receiving particles 16 on the surface by electrostatic force. For this purpose, the surface of the intermediate transfer member 12 needs to have a semiconductive or insulating particle holding property. For this reason, as for the electrical characteristics of the surface of the intermediate transfer body 12, in the case of semi-conductivity, the surface resistivity is 10 ¹⁰ Ω / □ or more and 10 ¹⁴ Ω / □ or less, and the volume resistivity is 10 ⁹ Ω · cm or more and 10 or more. ^{In the case of 13} Ω · cm or less, in the case of insulation, a member having a surface resistivity of 10 ¹⁴ Ω / □ and a volume resistivity of 10 ¹³ Ω · cm or more is used.

In the present embodiment, the intermediate transfer body 12 will be described on the assumption that a surface layer of ethylene propylene rubber (EPDM) having a thickness of 50 μm is formed on a base layer of a polyimide film having a thickness of 100 μm. Here, it is desirable that the surface resistance value is about 10 ¹³ Ω / □ and the volume resistance value is about 10 ¹² Ω · cm (semiconductive).

  When the intermediate transfer body 12 is in the shape of a belt, the substrate can be driven to rotate the belt in the apparatus, has the necessary mechanical strength, and particularly has the required heat resistance when using heat during transfer / fixing. Anything that has Specifically, polyimide, polyamideimide, aramid resin, polyethylene terephthalate, polyester, polyethersulfone, stainless steel and the like are used. Further, when the intermediate transfer body 12 has a drum shape, the base material may be aluminum, stainless steel, or the like.

  In order to exhibit a heating method by electromagnetic induction in a transfer step in a transfer device (heating roll) 22 and a fixing step in a fixing device (heating roll) 25 described later, the transfer device (heating roll) 22 or the fixing device ( Instead of the (heating roll) 25, a heat generating layer may be formed on the intermediate transfer body 12. A metal that generates electromagnetic induction is used for the heat generating layer. For example, nickel, iron, copper, aluminum, chromium or the like can be selected.

  The charging device 28 is disposed upstream of the particle supply device 18 in the movement direction of the intermediate transfer body 12. The charging device 28 charges the surface of the intermediate transfer body 12. Specifically, the charging device 28 charges the surface of the intermediate transfer body 12 to a positive charge by applying a charge opposite to the charge of the ink receiving particles 16 to the surface of the intermediate transfer body 12. In the present embodiment, the ink receiving particles 16 are supplied / adsorbed to the surface of the intermediate transfer body 12 by the electrostatic force generated by the electric field that can be formed between the supply roll 41 </ b> A and the supply roll 41 </ b> B of the particle supply device 18 and the surface of the intermediate transfer body 12. A possible potential may be formed.

  In this embodiment, the charging device 28 is used to apply a voltage between a driven roll 31 (connected to the ground) disposed between the charging device 28 and the intermediate transfer body 12 to charge the surface of the intermediate transfer body 12. The configuration is to let

Examples of the charging device 28 include a configuration in which an elastic layer is formed on a roll-shaped substrate. As the roll-shaped substrate, a rod-like or pipe-like member made of aluminum, stainless steel or the like is used, and an elastic layer in which a conductivity-imparting material is dispersed is formed on the outer peripheral surface, and a volume resistivity of 10 ⁶ Ω · A roll of φ10 mm or more and φ25 mm or less adjusted to about cm to 10 ⁸ Ω · cm is used as the charging device 28.

  This elastic layer is made of a resin material such as urethane resin, thermoplastic elastomer, epichlorohydrin rubber, ethylene-propylene-diene copolymer rubber, silicone rubber, acrylonitrile-butadiene copolymer rubber, and polynorbornene rubber. Used as a mixture of seeds or more, and a desirable material is urethane foam resin. As the foamed urethane resin, a resin obtained by mixing and dispersing a hollow body such as a hollow glass bead or a thermal expansion type microcapsule in a urethane resin to provide a closed cell structure is desirable. Furthermore, the surface of the elastic layer may be covered with a water-repellent coating layer having a thickness of 5 μm to 100 μm.

In the present embodiment, charging device 28 forms an elastic layer (foamed urethane resin) in which a conductivity-imparting material is dispersed on a rod-shaped outer peripheral surface made of stainless steel, and has a volume resistivity of 10 ⁶ Ω · cm or more. A roll-shaped member adjusted to about 10 ⁸ Ω · cm or less is used. Furthermore, the surface of the elastic layer is covered with a water / oil repellent coating layer (for example, composed of tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA)) having a thickness of 5 μm to 100 μm.

  A high voltage power source is connected to the charging device 28, and the driven roll 31 is electrically connected to the frame ground. The charging device 28 is driven while sandwiching the intermediate transfer body 12 with the driven roll 31, and a predetermined potential difference is generated with the grounded driven roll 31 at the pressed position. An electric charge can be given. Here, a voltage is applied to the surface of the intermediate transfer member 12 by the charging device 28 so that the surface potential becomes 1 kv, for example, and the surface of the intermediate transfer member 12 is charged. Further, the charging device 28 may be a non-contact charging device such as a corotron.

  On the upstream side of the charging device 28 in the moving direction of the intermediate transfer body 12, a release agent supply device 14 for supplying the release agent 14D to form the release layer 14A is disposed. The release agent supply device 14 forms a release layer 14 </ b> A of the release agent 14 </ b> D on the surface of the intermediate transfer body 12 before the ink receiving particles 16 are supplied onto the intermediate transfer body 12. Examples of the release agent 14D include release materials such as silicone oil, fluorine oil, polyalkylene glycol, and surfactant.

  The release agent supply device 14 includes a supply roll 14 </ b> C that supplies the release agent to the intermediate transfer body 12, and a blade 14 </ b> B that defines the layer thickness of the release agent supplied to the intermediate transfer body 12. .

  When the intermediate transfer member 12 is moved (moved in the moving direction), a release layer 14 </ b> A is formed on the surface of the intermediate transfer member 12 by the release agent supply device 14. The release agent 14D is supplied to the surface of the intermediate transfer body 12 by the supply roll 14C of the release agent supply device 14, and the layer thickness is defined by the blade 14B.

  At this time, the release agent supply device 14 may be in continuous contact with the intermediate transfer body 12 or may be configured to be separated from the intermediate transfer body 12 for the purpose of continuous image formation and printing. . Alternatively, the release agent 14D may be supplied to the release agent supply device 14 from an independent liquid supply system (not shown) so that the supply of the release agent 14D is not interrupted.

  The particle supply device 18 is provided upstream of the inkjet recording head 20 in the movement direction of the intermediate transfer body 12 (in the direction of arrow A in FIG. 1) and downstream of the charging device 28 in the movement direction. The particle supply device 18 supplies a plurality of types of ink receptive particles 16 having different softening temperatures to the intermediate transfer member 12 in a layered manner for each type of ink receptive particles 16, thereby providing an intermediate On the transfer body 12, a particle laminate 40 is formed of a plurality of types of ink receiving particles 16 having different softening temperatures.

  In the present embodiment, the ink receiving particles 16 are composed of a plurality of types of ink receiving particles having different softening temperatures. In the present embodiment, in order to simplify the description, two types of ink receiving particles 16 having different softening temperatures (ink receiving particles 16A and ink receiving particles having a lower softening temperature than the ink receiving particles 16A) are used. Although the case where the property particle | grains 16B) are used is demonstrated, it is not restricted to two types.

  As a method for supplying the ink receiving particles 16, a one-component developing method or a two-component developing method, which is a method for developing a photoconductor with a general electrophotographic toner, may be used. In the present embodiment, the one-component development method is described as being applied, but the present invention is not limited to this method.

  As shown in FIGS. 2 and 3A, the particle supply device 18 is a layer (hereinafter referred to as the intermediate transfer body 12) closest to the intermediate transfer body 12 among the layers of the particle stack 40 formed on the intermediate transfer body 12. The ink receiving particles constituting the layer (hereinafter, appropriately referred to as the second layer) 17B where the softening temperature of the ink receiving particles 16A constituting the 17A constituting the 17A constituting the 17A is the farthest from the intermediate transfer body 12 (hereinafter, appropriately referred to as the second layer). Each type of ink receiving particles 16 (ink receiving particles 16A and ink receiving particles 16B) is supplied onto the intermediate transfer body 12 so as to be higher than the softening temperature of 16B.

  In the present embodiment, in order to simplify the description, it is assumed that two types (ink receiving particles 16A and ink receiving particles 16B) are used as the plurality of types of ink receiving particles 16 having different softening temperatures. The particle supply device 18 includes a particle supply device 18A and a particle supply device 18B. The particle supply device 18A and the particle supply device 18B are arranged along the moving direction of the intermediate transfer body 12 (the direction of arrow A in FIG. 1), and the particle supply device 18A is more intermediate than the particle supply device 18B. It is provided upstream of the transfer body 12 in the moving direction.

  The particle supply device 18A and the particle supply device 18B supply the ink receiving particles 16 having different softening temperatures to the intermediate transfer body 12 in a layered manner. Specifically, the particle supply device 18A provided on the upstream side in the moving direction of the intermediate transfer body 12 from the particle supply device 18B is provided with particles provided on the downstream side so as to form the first layer 17A. The ink receiving particles 16A having a higher softening temperature are supplied from the supply device 18B. The particle supply device 18B supplies the ink receiving particles 16B having a lower softening temperature than the particle supply device 18A so as to form the second layer 17B. Thereby, on the intermediate transfer body 12, a particle laminate 40 is formed in which the second layer 17B made of the ink receiving particles 16B is laminated on the first layer 17A made of the ink receiving particles 16A.

Here, the softening temperature of the ink receptive particles 16 (ink receptive particles 16A and ink receptive particles 16B) used in the present embodiment is such that the ink receptive particles 16 supplied onto the intermediate transfer body 12 are transferred to the transfer device. 22 is set to a temperature equal to or lower than the temperature required for the transfer to the recording medium 8. In the present embodiment, the softening temperature of the ink receiving particles 16 is specifically a temperature at which the dynamic shear modulus is in the range of 10 ³ dyn / cm ^{2 to} 10 ⁷ dyn / cm ² , Within this range, the softening temperatures of the ink receiving particles 16A and the ink receiving particles 16B are adjusted.

The softening temperature was measured using a thermomechanical analyzer (TMA) under the measurement condition of a temperature increase of 5 ° C./min. The test is performed according to JIS 7197.
The dynamic shear modulus G is measured in accordance with, for example, JIS K6301 and K6394.

The softening temperature of the ink receiving particles 16A supplied to the side closest to the intermediate transfer member 12 by the particle supply device 18A is supplied to the side farthest from the intermediate transfer member 12 side (the discharge surface on which ink droplets are discharged). It is essential that the temperature be higher than the softening temperature of the ink receiving particles 16B.
The ink-receptive particles 16B preferably have a lower softening temperature to improve transferability, and the ink-receptive particles are preferably higher to improve storage stability. It is preferably higher by at least 30 ° C, more preferably by at least 30 ° C, particularly preferably by at least 50 ° C.

  Further, the softening temperature of the ink receiving particles 16A is preferably higher than the environmental temperature, and more preferably 30 ° C. or higher. In the present embodiment, the environmental temperature indicates the maximum temperature in the environment where the recording apparatus 10 is installed.

  Specifically, the softening temperature of the ink receiving particles 16A is preferably higher than 50 ° C. and lower than 150 ° C., preferably higher than 80 ° C. and lower than 120 ° C.

  On the other hand, the softening temperature of the ink receiving particles 16B supplied to the side farthest from the intermediate transfer body 12 (the layer serving as the discharge surface from which ink droplets are discharged) by the particle supply device 18B is the most intermediate transfer as described above. It is essential that the temperature is lower than the softening temperature of the ink receiving particles 16B supplied to the side close to the body 12.

  The softening temperature of the ink receiving particles 16B is preferably 100 ° C. or lower, which is the boiling point of water, in order to suppress image quality deterioration and achieve high transfer efficiency. Further, the softening temperature of the ink receiving particles 16B is more preferably less than 50 ° C. from the viewpoint of realizing high-speed transfer and reduction of thermal energy required at the time of transfer, and the particle laminate at normal temperature (25 ° C.). The temperature is particularly preferably less than 30 ° C. from the viewpoint of realizing high transfer efficiency to 40 recording media 8.

As these ink receiving particles 16A and ink receiving particles 16B, the softening temperature of the ink receiving particles 16A supplied to the side closest to the intermediate transfer body 12 is farthest from the intermediate transfer body 12 as described above. As long as it is higher than the softening temperature of the ink receiving particles 16B supplied to the side, the constituent materials may be the same or different.
The details of the ink receiving particles 16 will be described later.

  By making the materials constituting the ink receiving particles 16A and the ink receiving particles 16B the same, both the ink receiving particles 16A and the ink receiving particles 16B are manufactured with simple manufacturing conditions and manufacturing steps. Further, when the material constituting the ink receiving particles 16A and the ink receiving particles 16B are the same, the particle stack 40 formed on the recording medium 8 is fixed to the recording medium 8 by the fixing device 25. As compared with the case where the constituent materials are different, good compatibility between the ink receiving particles 16A and the ink receiving particles 16B can be obtained.

  In order to configure the softening temperatures of the ink receptive particles 16A and the ink receptive particles 16B to be different as described above, for example, the same constituent materials can be used and the ratio of the constituent materials can be adjusted. The

  The particle supply device 18A for supplying the ink receptive particles 16A and the particle supply device 18B for supplying the ink receptive particles 16B have ink receptive particles via a supply tube 19A and a supply tube 19B, respectively. The storage cartridge 21A and the ink receiving particle storage cartridge 21B are detachably connected.

  In the particle supply device 18A, ink receiving particles 16A supplied from the ink receiving particle storage cartridge 21A are stored. A supply roll 41A is disposed in a region of the particle supply device 18A facing the intermediate transfer body 12, and a charging blade 42A is disposed so as to press the supply roll 41A. The charging blade 42A also has a function of regulating the layer thickness of the ink receiving particles 16A supplied to the surface of the supply roll 41A.

  The ink receiving particles 16A in the particle supply device 18A are supplied to the supply roll 41A (conductive roll), charged by the charging blade 42A, and supplied to the intermediate transfer body 12 (that is, the intermediate transfer body). The layer thickness when the toner is supplied in a layer form on the surface 12 is adjusted and supplied to the intermediate transfer member 12. The supply roll 41A is a solid aluminum roll, and the charging blade 42A is a metal plate (SUS or the like) to which urethane rubber is attached in order to apply pressure.

  The ink receiving particles 16A charged by the charging blade 42A are formed, for example, on the surface of the supply roll 41A as one layer (a layer corresponding to one particle, the same applies hereinafter), and face the surface of the intermediate transfer body 12 by the rotation of the supply roll 41A. The charged ink receiving particles 16A move to the surface of the intermediate transfer member 12 by electrostatic force due to the electric field formed by the potential difference between the supply roll 41A and the surface of the intermediate transfer member 12 (FIGS. 1 and 2). 2 and FIG. 3 (A)).

  The supply amount per unit area of the ink receiving particles 16A supplied onto the intermediate transfer body 12 is preferably smaller than the supply amount per unit area of the ink receiving particles 16B. Furthermore, only the particles in contact with the surface of the intermediate transfer body 12 act to improve the transfer efficiency of the particle stack 40 from the intermediate transfer body 12, and the cost of the particles and the energy required for fixing to the recording medium 8 are reduced. From the viewpoint of realization, approximately one layer is more preferable. The ink receiving particles 16B supplied onto the intermediate transfer body 12 may be supplied so as to be scattered on the intermediate transfer body 12, as shown in FIG.

  The supply amount of the ink receiving particles 16A is adjusted by relatively setting the moving speed of the intermediate transfer body 12 and the rotation speed of the supply roll 41A (peripheral speed ratio) in the particle supply device 18A. This peripheral speed ratio depends on other parameters such as the charge amount of the intermediate transfer member 12, the charge amount of the ink receiving particles 16A, the positional relationship between the supply roll 41A and the intermediate transfer member 12, and the like.

  The absolute value of the charge amount of the ink receiving particles 16A is preferably in the range of 5 μC / g to 50 μC / g.

  Similarly, the ink receiving particles 16B supplied from the ink receiving particle storage cartridge 21B are stored in the particle supply device 18B. A supply roll 41B is disposed in a region of the particle supply device 18B facing the intermediate transfer body 12, and a charging blade 42B is disposed so as to press the supply roll 41B. The charging blade 42B also has a function of regulating the layer thickness of the ink receiving particles 16B supplied to the surface of the supply roll 41B.

  The ink receiving particles 16B in the particle supply device 18B are supplied to the supply roll 41B (conductive roll), charged by the charging blade 42B, and supplied to the intermediate transfer body 12 (that is, the intermediate transfer body). The layer thickness when the toner is supplied in a layer form on the surface 12 is adjusted and supplied to the intermediate transfer member 12. The supply roll 41B is a solid aluminum roll, and the charging blade 42B is a metal plate (SUS or the like) to which urethane rubber is attached in order to apply pressure.

  The ink receptive particles 16B charged by the charging blade 42B are preferably formed in a plurality of layers (a layer corresponding to a plurality of particles, the same applies hereinafter) on the surface of the supply roll 41B. The charged ink receiving particles 16B are transported to a region facing the surface of the intermediate transfer body 12 by the rotation of the supply roll 41B, and the charged ink receiving particles 16B are electrostatically charged by the electric field formed by the potential difference between the supply roll 41B and the surface of the intermediate transfer body 12. As a result, the intermediate transfer member 12 moves.

  At this time, since the ink receiving particles 16A are already supplied in layers by the particle supply device 18A on the intermediate transfer body 12, the first layer 17A is provided. The ink receiving particles 16B are supplied so as to be laminated on the layer of the conductive particles 16A (the first layer 17A) (see FIGS. 1, 2, and 3B).

  The supply amount of the ink receiving particles 16B supplied onto the first layer 17A by the ink receiving particles 16A depends on the amount of ink droplets 20A supplied from the inkjet recording head 20, but a plurality of layers are formed. It is preferable.

  For this purpose, the intermediate transfer body 12 is moved so that a particle layer (second layer 17B) is formed by a plurality of layers of ink receiving particles 16B on the first layer 17A of the ink receiving particles 16A. The speed and the rotation speed of the supply roll 41B may be set relatively (peripheral speed ratio). This peripheral speed ratio depends on other parameters such as the charge amount of the intermediate transfer member 12, the charge amount of the ink receiving particles 16B, and the positional relationship between the supply roll 41B and the intermediate transfer member 12.

The peripheral speed ratio for forming a single particle layer by the ink receiving particles 16B is measured in advance and used as a reference, and the peripheral speed of the supply roll 41B is relatively increased to supply the intermediate transfer body 12. The number of ink receptive particles 16B to be increased is increased. On the other hand, when the transferred image density is low (the amount of ink shot is small (for example, 0.1 g / m ² or more and 1.5 g / m ² or less)), the layer thickness of the ink receiving particles 16B is minimized. In the case of a thickness (for example, 1 μm or more and 5 μm or less) and a high image density (a large amount of ink shot (for example, 4 g / m ² or more and 15 g / m ² or less)), an ink liquid component (solvent or dispersion medium) The thickness of the second layer 17B by the ink receiving particles 16B (that is, the supply amount of the ink receiving particles 16B) can be adjusted so that the layer thickness is sufficient (for example, 10 μm or more and 25 μm or less). desirable.

  For example, in the case of a character image or the like with a small amount of ink shot, when an image is formed on the second layer 17B of one layer of the ink receiving particles 16B, the image forming material (pigment) in the ink is an intermediate transfer member. 12 is trapped on the surface of the particle layer (second layer 17B) of the ink receptive particles 16B on the surface 12 and fixed to the surface of the ink receptive particles 16B or inside the particle void so that the distribution in the depth direction decreases. However, when the amount of ink shot is large, that is, when an image with a high density is formed, the ink distribution in the depth direction of the ink receiving particles 16B increases as the density of the ink increases. It is preferable that the active particles 16B have a plurality of layers, and high-quality image formation is realized.

In addition, when forming an image having a large amount of ink shot compared to the primary color, such as a secondary color image or a tertiary color image, the ink liquid component (solvent or dispersion medium) can be retained, and a recording material (for example, a pigment) ) Is captured, and a plurality of layers of the ink receiving particles 16B are laminated so that the ink does not reach the layer (the first layer 17A) of the ink receiving particles 16A constituting the lowermost layer (the first layer 17A). It is preferable.
If the ink or the pigment in the ink does not reach the ink receiving particle 16A side (the first layer 17A side) supplied to the side closest to the intermediate transfer body 12, the surface of the image layer after the transfer / fixing is fixed. The image forming material (pigment) is not exposed, and the ink receiving particles 16 that do not receive ink among the ink receiving particles 16 constituting the particle laminate 40 are formed as a protective layer on the image surface. Become. For this reason, the abrasion resistance and heat resistance of the particle laminated body 40 after being fixed to the recording medium 8 can be improved, and deterioration of the image after fixing is suppressed.

  In the present embodiment, the particle stack 40 formed on the intermediate transfer member 12 by the particle supply device 18A and the particle supply device 18B is the first layer 17A that is the layer closest to the intermediate transfer member 12 side. Although it is assumed that the second layer 17B is laminated thereon, the same softening as that of any of the ink receiving particles 16A and the ink receiving particles 16B is performed between the first layer 17A and the second layer 17B. A configuration in which one or more layers of the ink receiving particles 16 having a softening temperature different from the softening temperature of the temperature or both particles is laminated may be used.

In this case, although illustration is omitted, the particle supply device 18 is not composed of two particle supply devices of two particle supply devices 18A and 18B, but three or more particle supply devices. What is necessary is just to include the structure. In this case, three or more particle supply devices included in the particle supply device 18 are arranged along the movement direction of the intermediate transfer body 12 and the most upstream particle supply device in the movement direction of the intermediate transfer body 12. Is the particle supply device 18A described above, and the particle supply device on the most downstream side in the moving direction of the intermediate transfer body 12 is the particle supply device 18B described above.
In this case, even when the configuration includes three or more particle supply devices 18, the layer (first layer) closest to the intermediate transfer body 12 is ink-accepting by the particle supply device 18. A plurality of layers are formed such that the layers are composed of the particles 16A, and the layer farthest from the intermediate transfer body 12 (second layer), that is, the layer where the ink droplets are ejected is the layer composed of the ink receiving particles 16B. A layered particle body 40 composed of layers is formed on the intermediate transfer body 12.

In this way, in this way, the particle stack 40 is softened between the first layer 17A and the second layer 17B with the same softening temperature or both of the ink receiving particles 16A and the ink receiving particles 16B. In the case where one or a plurality of layers of the ink receptive particles 16 having a softening temperature different from the temperature are stacked, the ink having a lower softening temperature from the first layer 17A to the second layer 17B. It is preferable to configure so that layers of receptive particles 16 are laminated.
For example, when the difference in softening temperature between the first layer 17A and the second layer 17B is large, when the particle laminate 40 is fixed to the recording medium 8, the compatibility between these two layers is low and the fixing performance is poor. However, there is one layer of ink receiving particles 16 having a softening temperature intermediate between the first layer 17A and the second layer 17B between the first layer 17A and the second layer 17B. The compatibility of the first layer 17A and the second layer 17B can be improved.

The ink jet recording head 20 ejects ink droplets 20 </ b> A corresponding to the image to be formed from the nozzles 20 </ b> B onto the particle stack 40 stacked on the intermediate transfer body 12.
The inkjet recording head 20 includes an inkjet recording head 20K that ejects black ink droplets, an inkjet recording head 20C that ejects cyan ink droplets, an inkjet recording head 20M that ejects magenta ink droplets, and a yellow ink droplet. The ink jet recording head 20Y is configured to be ejected. From each nozzle 20B (see FIG. 2) of each of these inkjet recording head 20C, inkjet recording head 20M, inkjet recording head 20Y, and inkjet recording head 20K (generically referred to as inkjet recording head 20). Ink droplets 20A of each color corresponding to the image to be formed are ejected toward the ink receiving particles 16B constituting the second layer 17B farthest from the intermediate transfer body 12 of the particle stack 40 (FIG. 3). (See (C)).
As the ink jet recording head 20, either a piezoelectric (piezo) or a thermal type may be used.

  The transfer device 22 transfers the particle laminated body 40 on which an image is formed by discharging the ink droplets 20 </ b> A from the inkjet recording head 20 to the recording medium 8. At this time, as shown in FIGS. 1 and 2, the transfer device 22 sandwiches the recording medium 8 with the intermediate transfer body 12 and applies pressure and heat to the particle stack 40, so that the recording medium 8 is placed on the recording medium 8. The particle stack 40 is transferred (see FIG. 5).

  The transfer device 22 includes a heating roll 22A having a built-in heating source and a pressure roll 22B facing each other with the intermediate transfer body 12 interposed therebetween. The heating roll 22A and the pressure roll 22B are in contact with each other to form a contact portion. For the heating roll 22A and the pressure roll 22B, a product in which the outer surface of the aluminum core is coated with silicone rubber and further coated with a PFA tube is used.

  At this time, the resin constituting the ink receptive particles 16B constituting the second layer 17B closest to the ink jet recording head 20 in the ink receptive particles 16 constituting the particle laminate 40 absorbs the ink. By doing so, adhesiveness is expressed and the glass transition temperature (Tg) is lowered. For this reason, the adhesiveness is increased even by heating below Tg. The particle layer 40 is peeled from the release layer 14A formed on the surface of the intermediate transfer body 12 by applying a pressure while further increasing the transfer efficiency by heating the liquid-absorbed second layer 17B. The body 40 is transferred onto the recording medium 8. The intermediate transfer body 12 may be preheated before the transfer device 22.

  Further, the ink receiving particles 16B constituting the second layer 17B farthest from the intermediate transfer body 12 among the ink receiving particles 16 constituting the particle laminated body 40 have a softening temperature higher than that of the ink receiving particles 16A. Therefore, the thermal energy applied during transfer may be small, and the particle stack 40 can be transferred efficiently. Further, at least softening is achieved by forming the particle layer 40 on the intermediate transfer body 12 with the first layer 17A closest to the intermediate transfer body 12 and the second layer 17B closest to the intermediate transfer body 12. Since it is only necessary to improve the adhesiveness of the ink receiving particles 16B having a low temperature, the time required for raising the temperature of the ink receiving particles 16 constituting the particle laminate 40 to a temperature at which the transfer can be performed in the transfer device 22 is reduced. It can be shortened. Therefore, high-speed transfer of the particle stack 40 to the recording medium 8 is possible, and transfer efficiency can be improved.

  The cleaning device 24 is provided downstream of the transfer device 22 in the moving direction of the intermediate transfer body 12 (in the direction of arrow X in FIG. 1). The cleaning device 24 removes ink-receptive particles 16D remaining on the surface of the intermediate transfer body 12, and removes extraneous matters other than the particles (such as paper dust of the recording medium 8).

  If necessary, the intermediate transfer body 12 is provided between the cleaning device 24 and the release agent supply device 14 (hereinafter, “between A and B unless otherwise specified”). You may arrange | position the static elimination apparatus 29 for removing the electric charge which remains on the surface. For example, a conductive roll is used as the static elimination device 29 and is sandwiched between the driven roll 31 (ground) and a voltage of about ± 3 kV and 500 Hz is applied to the surface of the intermediate transfer body 12 to neutralize the surface of the intermediate transfer body 12. .

  The fixing device 25 fixes the particle laminate 40 on the recording medium 8 to which the particle laminate 40 has been transferred to the recording medium 8. The fixing device 25 includes a heating roll 25A containing a heating source, and a pressure roll 25B facing the heating roll 25A. The heating roll 25A and the pressure roll 25B are in contact with each other to form a contact portion. As the heating roll 25A and the pressure roll 25B, for example, an outer surface of an aluminum core covered with silicone rubber and further coated with a PFA tube is used.

The fixing device 25 sandwiches the recording medium 8 onto which the particle stack 40 is transferred between the heating roll 25A and the pressure roll 25B, and the ink receiving particles of the particle stack 40 are transferred to the particle stack 40 by the heating roll 25A. A pressure is applied to the particle laminate 40 by the pressure roll 25 </ b> B while applying heat of, for example, a glass transition temperature (Tg) or more of an organic resin (described later in detail) constituting 16.
The particle laminated body 40 on the recording medium 8 is softened (or melted) when the organic resin constituting the particle laminated body 40 is heated to a glass transition point (Tg) or higher and recording is performed by applying pressure. It is fixed on the medium 8. The ink liquid component (solvent or dispersion medium) held in the particle stack 40 is held in the particle stack 40 as it is after transfer / fixing.

  As shown in FIG. 5, the particle stack 40 fixed on the recording medium 8 is in a state in which the second layer 17 </ b> B and the first layer 17 </ b> A are sequentially stacked on the recording medium 8. Therefore, among the ink receiving particles 16 constituting the particle laminated body 40 transferred and fixed on the recording medium 8, the second ink containing the ink receiving particles 16B that have received the ink droplets 20A closest to the recording medium 8 side. Layer 17B is located, and the first layer 17A made of ink-receptive particles A is located on the most surface side (the side far from the recording medium 8). That is, the first layer 17A composed of the ink receptive particles 16A having a high softening temperature protects the second layer 17B composed of the ink receptive particles 16B having a low softening temperature and receiving the ink droplets 20A. Thus, good blocking resistance, image abrasion resistance, and heat resistance are realized.

  Note that the various conditions such as the charging voltage, particle layer thickness, and fixing temperature are determined by the ink receiving particles 16 or the composition of the ink, the amount of ink discharged, etc. You can optimize.

  Hereinafter, the image forming process of the recording apparatus 10 according to the present embodiment will be described in more detail.

  In the recording apparatus 10 according to the present embodiment, as shown in FIGS. 1 and 2, a release layer 14 </ b> A is formed on the surface of the intermediate transfer body 12 by a release agent supply device 14.

  The release layer 14A is not necessarily formed on the intermediate transfer body 12, but is formed on the intermediate transfer body 12 when the material of the intermediate transfer body 12 is aluminum or PET base. In order to suppress a decrease in transferability of the particle laminate 40 to the recording medium 8, it is particularly desirable to form the release layer 14A. When the release layer 14A is not formed on the intermediate transfer body 12, the surface itself of the intermediate transfer body 12 is provided with release properties by using a fluororesin / silicone rubber material. do it.

  Next, the surface of the intermediate transfer member 12 is charged to a polarity opposite to that of the ink receiving particles 16 by the charging device 28.

When the region charged by the charging device 28 on the intermediate transfer member 12 reaches the region where the particle supply device 18A is provided by the movement of the intermediate transfer member 12 in the moving direction, ink is supplied by the supply roll 41A of the particle supply device 18A. The receptive particles 16A are supplied in layers (see FIG. 2 and FIG. 3A).
Since the intermediate transfer member 12 is charged by the charging device 28, the ink receiving particles 16 supplied from the particle supply device 18 (particle supply device 18A and particle supply device 18B) are transferred to the intermediate transfer member 12. The particles are electrostatically attracted to form a particle laminate 40 of the ink receiving particles 16 on the surface of the intermediate transfer body 12.

  As described above, the supply amount of the ink receiving particles 16A per unit area supplied to form the first layer 17A is supplied to form the second layer 17B to be stacked later. The amount of the ink receiving particles 16B per unit area is smaller than that of the ink receiving particles 16B, and may be one layer or sparsely supplied. As described above, the supply amount of the ink receiving particles 16A is adjusted by the gap between the charging blade 42A and the supply roll 41A. The supply amount of the ink receiving particles 16A may be controlled by the peripheral speed ratio between the supply roll 41A and the intermediate transfer body 12.

When the region formed by the first layer 17A of the ink receiving particles 16A on the intermediate transfer body 12 reaches the region where the particle supply device 18B is provided by the movement of the intermediate transfer body 12 in the movement direction, The ink receiving particles 16B are supplied in layers by the supply roll 41B of the particle supply device 18B to form the second layer 17B (see FIGS. 2 and 3B).
Here, since the first layer 17A of the ink receiving particles 16A having a higher softening temperature than the ink receiving particles 16B is formed on the intermediate transfer body 12 by the particle supplying device 18A, the particle supplying device 18B. The ink receiving particles 16B supplied from is supplied so as to be laminated on the first layer 17A by the ink receiving particles 16A on the intermediate transfer body 12.

  As described above, the second layer 17B of the ink receiving particles 16B is preferably a plurality of layers. As described above, the layer thickness of the second layer 17B by the ink receiving particles 16B is adjusted by the gap between the charging blade 42B and the supply roll 41B. The layer thickness of the ink receiving particles 16B may be controlled by the peripheral speed ratio between the supply roll 41B and the intermediate transfer body 12.

  In this manner, the first layer 17A composed of the ink receiving particles 16A is formed on the intermediate transfer body 12, and the second layer 17B made of the ink receiving particles 16B is formed on the first layer 17A. As a result, the particle stack 40 is formed on the intermediate transfer body 12.

  When the area of the intermediate transfer body 12 in which the particle stack 40 is formed reaches the area where the ink droplets 20A can be ejected from the inkjet recording head 20 due to the movement of the intermediate transfer body 12, the inkjet recording head 20 generates an image signal. Based on this, ink droplets are ejected onto the particle stack 40. The ink droplets are ejected toward the second layer 17B of the particle stack 40, and by ejection of the ink droplets, the particle stack 40 has an image layer 16C (see FIG. 3C). A layer of ink receiving particles 16 that have received ink among the ink receiving particles 16 of the particle stack 40 is formed.

  Liquid components such as a solvent and a dispersion medium contained in the ink droplets 20A ejected from the inkjet recording head 20 to the particle stack 40 are quickly absorbed by the gaps between the ink receiving particles 16B and the gaps constituting the ink receiving particles 16B. At the same time, the recording material (for example, pigment) contained in the ink droplet 20A is also trapped on the surface of the ink receiving particles 16B or in the gaps between the particles constituting the ink receiving particles 16B.

  In this case, it is desirable to capture (trap) many recording materials (for example, pigments) on the surface of the particle stack 40. The inter-particle voids in the ink receiving particles 16 exhibit a filter effect, and the recording material (for example, pigment) is trapped on the surface of the particle laminate 40 and is trapped in the inter-particle voids in the ink receiving particles 16. And expressed by being fixed.

  In order to reliably trap the recording material (for example, pigment) on the surface of the particle stack 40 and the interparticle gap in the ink receiving particle 16, the recording material (for example, pigment) is reacted by causing the ink and the ink receiving particle 16 to react. ) May be quickly insolubilized (aggregated). Specifically, it is possible to apply a reaction between the ink and the polyvalent metal salt or a pH reaction type as the reaction.

  The ink jet recording head 20 is preferably a line type ink jet recording head having a width equal to or larger than the width of the recording medium 8, but is formed on the intermediate transfer body 12 using a conventional scan type ink jet recording head. Images may be sequentially formed on the formed particle stack 40. The ink discharge means of the inkjet recording head 20 is not limited as long as it is a means capable of discharging ink, such as a piezoelectric element drive type and a heating element drive type. As the ink itself, an ink using a conventional dye as a coloring material can be used, but a pigment ink is desirable (the ink will be described in detail later).

  In this way, the ink droplets 20A ejected from the inkjet recording head 20 are ejected toward the second layer 17B and received by the particle laminate 40.

  At this time, the liquid component contained in the ink droplet 20A may permeate in the thickness direction of the particle stack 40 and reach the first layer 17A, but the recording material such as a pigment is the second layer 17B of the particle stack 40. Are trapped in the surface of the ink receiving particles 16B or the voids between the ink receiving particles 16B. That is, the ink liquid component may penetrate into the first layer 17A in the thickness direction of the particle stack 40, but the recording material such as a pigment does not penetrate into the first layer 17A of the particle stack 40.

  Next, the particle laminated body 40 on which the image layer 16 </ b> C is formed is transferred from the intermediate transfer body 12 onto the recording medium 8 by the transfer device 22, and then fixed to the recording medium 8 by the fixing device 25.

  At the time of transfer by the transfer device 22, as shown in FIG. 2, the first layer 17A that is in contact with the intermediate transfer body 12 in the particle stack 40 is peeled off from the intermediate transfer body 12, thereby the particle stack. 40 is peeled off from the intermediate transfer body 12 and transferred to the recording medium 8. Here, as described above, the second layer 17B is composed of the ink receptive particles 16B having a softening temperature lower than that of the ink receptive particles 16A. Will improve. For this reason, the particle laminated body 40 is efficiently transferred to the recording medium 8, and the transfer speed can be improved.

  When the particle stack 40 is transferred to the recording medium 8 by the transfer device 22, the first layer 17 A of the particle stack 40 contacts the recording medium 8 and the second layer 17 B is the most from the recording medium 8. It is transferred to the recording medium 8 so as to be a separated layer. For this reason, after fixing by the fixing device 25, the image layer 16C is protected by the first layer 17A by the ink receiving particles 16A having the higher softening temperature. Therefore, the abrasion resistance of the image layer 16C on which the image is formed can be obtained.

  Through the above steps, image formation on the recording medium 8 is completed. With respect to the intermediate transfer body 12, when there are foreign matters such as residual particles 16 </ b> D remaining on the intermediate transfer body 12 after the ink receiving particles 16 are transferred to the recording medium 8 or paper dust detached from the recording medium 8. May be removed by the cleaning device 24.

  For example, residual particles 16D remaining on the surface of the intermediate transfer body 12 after the particle laminate 40 is peeled off are collected by the cleaning device 24 (see FIG. 1), and the surface of the intermediate transfer body 12 is charged again by the charging device 28. Then, the ink receiving particles 16 are supplied to form the particle stack 40.

<Ink receiving particles>
Hereinafter, the ink receiving particles 16 suitably applied in the present embodiment will be described in detail. In the following description, the reference numerals are omitted.

  The ink receptive particles are those that receive ink components when the ink comes into contact with the particles. Here, the ink receptivity indicates holding at least a part (at least a liquid component) of the ink component. The ink receiving particles include, for example, at least an organic resin in which the ratio of polar monomers having polar groups to all monomer components is 10 mol% or more and 90 mol% or less. Specifically, the ink receiving particles include, for example, a configuration having particles configured to contain the organic resin (hereinafter referred to as hydrophilic organic particles) (hereinafter including the hydrophilic organic particles). Are called “mother particles”).

  Here, the ink-receptive particles being hydrophilic means that at least an organic resin having a ratio of polar monomers to all monomer components of 10 mol% or more and 90 mol% or less is included. These ink receiving particles have a property of being more sticky than hydrophobic.

  The ink receptive particles may have a form in which the mother particles are composed of particles (primary particles) of hydrophilic organic particles alone, or a form in which the mother particles are composed of composite particles in which at least hydrophilic organic particles are aggregated. Good.

  Here, in the case where the mother particles are composed of single particles (primary particles) of hydrophilic organic particles, when the ink receiving particles receive the ink, if the ink adheres to the ink receiving particles, at least the liquid component of the ink The ink liquid component is absorbed by the hydrophilic organic particles.

  In this way, the ink receiving particles receive ink. Then, recording is performed by transferring the ink receiving particles that have received the ink to a recording medium.

  On the other hand, in the case where the mother particles are composed of composite particles in which at least hydrophilic organic particles are aggregated, when the ink receiving particles receive ink, first, when the ink adheres to the ink receiving particles, at least the liquid of the ink The component is captured (trapped) by voids between particles (at least hydrophilic organic particles) constituting the composite particles (hereinafter, the interparticle voids may be referred to as trap structures). At this time, among the ink components, the recording material is attached to the surface of the ink receiving particles or trapped by the trap structure. In this way, the ink receiving particles receive ink. Then, recording is performed by transferring the ink receiving particles that have received the ink to a recording medium.

  The trapping (trapping) of the ink liquid component by the trap structure is a physical and / or chemical trapping by voids between particles (physical particle wall structure).

Then, by applying a form in which the mother particles are composed of composite particles in which at least hydrophilic organic particles are aggregated, trapping by traps (physical particle wall structure) between the particles constituting the composite particles is applied. In addition, the ink liquid component is absorbed and held by the hydrophilic organic particles.
Ink liquid components are also absorbed and retained by hydrophilic organic particles.

  Further, after the transfer of the ink receiving particles, the components of the hydrophilic organic particles constituting the ink receiving particles also function as a binder resin or a coating resin for the recording material contained in the ink. Further, when the ink receiving particles are composite particles, the recording material is trapped in the trap structure. In particular, it is desirable to apply a transparent resin as a component of the hydrophilic organic particles constituting the ink receiving particles.

  In addition, in order to improve the fixability (rubbing resistance) of an ink (for example, pigment ink) using an insoluble component such as a pigment or a dispersed particulate material as a recording material, it is necessary to add a large amount of resin to the ink. If a large amount of polymer is added to the processing liquid (including the treatment liquid), the reliability such as nozzle clogging of the ink discharge means is deteriorated. On the other hand, in the above configuration, the organic resin component constituting the ink receiving particles can also function as the resin.

  Here, “a void between particles constituting the composite particle”, that is, “trap structure” is a physical particle wall structure capable of capturing at least a liquid. The size of the gap is preferably 0.1 μm or more and 5 μm or less, and more preferably 0.3 μm or more and 1 μm or less in terms of the maximum aperture. In particular, the size of the gap is preferably a size capable of trapping a recording material, particularly, for example, a pigment having a volume sphere equivalent diameter of 100 nm. Micropores having a maximum opening diameter of less than 50 nm may exist. Moreover, it is good for the space | gap and the capillary tube to have communicated inside the particle | grains.

  The size of the gap is obtained as follows. It can be obtained by reading a scanning electron microscope (SEM) image of the particle surface with an image analysis device, detecting voids by binarization processing, and analyzing the size and distribution of the voids.

  As described above, the trap structure preferably traps not only the liquid component of the ink components but also the recording material. When a recording material, particularly a pigment, is trapped (trapped) together with the ink liquid component in the trap structure, the recording material is held and fixed without being unevenly distributed inside the ink receiving particles. The liquid component of the ink is mainly an ink solvent or a dispersion medium (vehicle liquid).

  Hereinafter, the ink receiving particles will be described in more detail. The ink receptive particles may have a form in which the mother particles are composed of single particles (primary particles) of hydrophilic organic particles as described above, and the mother particles are composed of composite particles in which at least hydrophilic organic particles are aggregated. There may be a form. Examples of particles other than the hydrophilic organic particles constituting the composite particles include inorganic particles and porous particles. Of course, the mother particle may be composed of composite particles in which only a plurality of hydrophilic organic particles are aggregated. In addition to the hydrophobic organic particles, for example, inorganic particles may be used as the particles to be attached to the surface of the mother particles.

  As specific configurations of the ink receiving particles, for example, as shown in FIG. 10, mother particles 201 composed of particles (primary particles) of hydrophilic organic particles 201 </ b> A alone, and inorganic particles attached to the mother particles 201. 202, and the form of the ink receiving particles 200 having the same. In addition, as shown in FIG. 11, an ink receptivity having base particles 201 of composite particles in which hydrophilic organic particles 201 </ b> A and inorganic particles 201 </ b> B are combined, and inorganic particles 202 attached to the base particles 201. The form of particle 210 is also mentioned. The composite particles have a void structure formed by voids between the particles.

  Here, when the mother particle is composed of composite particles, the mass ratio of hydrophilic organic particles to other particles (hydrophilic organic particles: other particles) is, for example, 5 when other particles are inorganic particles. 1 to 1:10 or less.

  In addition, the particle diameter of the base particle may be, for example, in the range of a sphere-converted sphere equivalent diameter of, for example, 0.1 μm to 50 μm (desirably 0.5 μm to 25 μm, more desirably 1 μm to 10 μm).

Further, when the mother particle is composed of composite particles, the BET specific surface area (N ₂ ) is, for example, in the range of 1 m ² / g or more and 750 m ² / g or less.

  When the mother particles are composed of composite particles, the composite particles are obtained, for example, by granulating the particles in a semi-sintered state. The semi-sintered state refers to a state in which a certain amount of particle shape remains and voids are retained between the particles. When the ink liquid component is trapped in the trap structure, at least a part of the particles may be dissociated, that is, the composite particles may be disassembled and the particles constituting the composite particles may be scattered.

  Next, the hydrophilic organic particles will be described. In the hydrophilic organic particles, for example, the ratio of the polar monomer to the total monomer component is 10 mol% or more and 90 mol% or less, desirably 15 mol% or more and 85 mol% or less, more desirably 30 mol% or more and 80 mol% or less. It is comprised including the organic resin which is. Specifically, the hydrophilic organic particles preferably include an organic resin having a ratio of the polar monomer (hereinafter referred to as a water-absorbing resin).

  Here, the polar monomer is a monomer containing an ethylene oxide group, a carboxylic acid, a sulfonic acid, a substituted or unsubstituted amino group, a hydroxyl group, an ammonium group, and a salt thereof as a polar group. For example, in the case of imparting positive chargeability, it is desirable to use a monomer having a chlorinated structure such as (substituted) amino group, ammonium group, (substituted) pyridine group, amine salts thereof, and quaternary ammonium salts. In the case of imparting negative charge, a monomer having an organic acid (salt) structure such as carboxylic acid (salt) or sulfonic acid (salt) is desirable.

  In addition, the ratio of a polar monomer is calculated | required as follows. First, the constitution of the organic component is identified from analysis techniques such as mass spectrometry, NMR, and IR. Then, based on JIS K0070 or JIS K2501, the acid value and base number of an organic component are measured. The ratio of the polar monomer can be calculated from the constitution of the organic component and the acid value / base value. The same applies hereinafter.

  The hydrophilic organic particles are made of, for example, a liquid absorbing resin. The absorbed ink liquid component (for example, water or an aqueous solvent) acts as a plasticizer for the resin (polymer), so it can soften and contribute to fixing properties.

  The liquid absorbing resin is preferably a weak liquid absorbing resin. This weak liquid-absorbent resin is, for example, a few percent (≈5%) to several hundred percent (≈500%), preferably about 5% to 150% of the resin mass when absorbing water as a liquid. A lyophilic resin capable of absorbing liquid.

  The liquid-absorbing resin can be composed of, for example, a homopolymer of a hydrophilic monomer or a copolymer composed of both a hydrophilic monomer and a hydrophobic monomer. In order to obtain a weak water-absorbing resin, the copolymer is desirable. In addition, not only the monomer but also a graft copolymer or block copolymer in which other units such as a polymer / oligomer structure are copolymerized as a start may be used.

Here, as a hydrophilic monomer, -OH, -EO unit (ethylene oxide group), -COOM (M is alkali metal, such as hydrogen, Na, Li, and K, ammonia, organic amines, etc.). ), - _SO 3 M (M is, for example, hydrogen, Na, Li, alkali metals K, etc., ammonia, organic amines, etc.), - _NR 3 (R is, for example, H, alkyl, phenyl, etc.). - NR ₄ X (R is, for example, H, alkyl, phenyl, etc., and X is, for example, halogen, sulfate radical, acid anions such as carboxylic acid, BF ₄ , etc.) and the like. It is done. Specific examples include 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, acrylamide, acrylic acid, methacrylic acid, unsaturated carboxylic acid, crotonic acid, maleic acid, and the like. Examples of hydrophilic units or monomers include cellulose derivatives such as cellulose, ethyl cellulose, carboxymethyl cellulose, starch derivatives, monosaccharide / polysaccharide derivatives, vinyl sulfonic acid, styrene sulfonic acid, acrylic acid, methacrylic acid, (anhydrous) Polymeric carboxylic acids such as maleic acid, (partially) neutralized salts thereof, vinyl alcohols, vinyl pyrrolidone, vinyl pyridine, derivatives such as amino (meth) acrylate and dimethylamino (meth) acrylate, and oniums thereof Salts, amides such as acrylamide and isopropylacrylamide, polyethylene oxide chain-containing vinyl compounds, hydroxyl group-containing vinyl compounds, polyesters composed of polyfunctional carboxylic acids and polyhydric alcohols, especially trimellitic acid Branched polyester containing a large amount of content and terminal carboxylic acid or hydroxyl functionality more acid as a constituent component, a polyester containing polyethylene glycol structure, etc. may be mentioned.

  Examples of the hydrophobic monomer include monomers having a hydrophobic group. Specifically, for example, olefin (ethylene, butadiene, etc.), styrene, α-methylstyrene, α-ethylstyrene, methyl methacrylate, Examples include ethyl methacrylate, butyl methacrylate, acrylonitrile, vinyl acetate, methyl acrylate, ethyl acrylate, butyl acrylate, and lauryl methacrylate. Hydrophobic units or monomers include styrene derivatives such as styrene, α-methylstyrene, vinyltoluene, vinylcyclohexane, vinylnaphthalene, vinylnaphthalene derivatives, alkyl acrylate esters, phenyl acrylate esters, alkyl methacrylate esters, methacrylic acid Examples thereof include phenyl ester, methacrylic acid cycloalkyl ester, crotonic acid alkyl ester, itaconic acid dialkyl ester, maleic acid dialkyl ester and the like, and derivatives thereof.

  Specific examples of the liquid absorbing resin that is a copolymer of the hydrophilic monomer and the hydrophobic monomer include, for example, (meth) acrylic acid esters, styrene / (meth) acrylic acid / (anhydrous). ) Preferred are maleic acid copolymers, olefin polymers such as ethylene / propylene (or modified products thereof, or carboxylic acid unit introduced products by copolymerization), branched polyesters and polyamides whose acid value has been improved with trimellitic acid, etc. Can be mentioned.

  Examples of the liquid absorbent resin include a neutral salt structure (for example, carboxylic acid). This neutralized salt structure such as carboxylic acid forms an ionomer by interaction with the cation when ink containing a cation (for example, a monovalent metal cation such as Na or Li) is absorbed.

  It is also desirable that the liquid absorbent resin contains a substituted or unsubstituted amino group or a substituted or unsubstituted pyridine group. The group exerts a bactericidal effect and interaction with a recording material having an anionic group (for example, pigment or dye).

  Here, in the liquid absorbent resin, the molar ratio (hydrophilic monomer: hydrophobic monomer) between the hydrophilic unit (hydrophilic monomer) and the hydrophobic unit (hydrophilic monomer) is, for example, 5:95 or more and 70:30 or less.

  Further, the absorbent resin may be ion-crosslinked with ions supplied from the ink. Specifically, a unit containing a carboxylic acid in the resin such as a copolymer containing a carboxylic acid such as (meth) acrylic acid or maleic acid or a (branched) polyester having a carboxylic acid is present in the water-absorbing resin. Can do. Ionic crosslinking and acid / base interaction occur between the carboxylic acid in the resin and the alkali metal cation, alkaline earth metal cation, organic amine / onium cation, etc. supplied from the liquid such as water-based ink.

  The common characteristics of the liquid-absorbing resin and the non-liquid-absorbing resin (hereinafter collectively referred to as organic resin) constituting the hydrophobic organic particles will be described.

  The liquid-absorbent resin may have a straight chain structure, but a split structure. Further, the liquid absorbent resin is preferably non-crosslinked or low crosslinked. The liquid-absorbing resin may be a linear random copolymer or block copolymer, but a branched polymer (including a branched random copolymer, block copolymer, and graft copolymer). Can be used more suitably. For example, in the case of polyester synthesized by polycondensation, end groups can be increased in a branched structure. This branched structure can be synthesized by adding so-called cross-linking agents such as divinylbenzene and di (meth) acrylates during synthesis (for example, adding less than 1%) or adding a large amount of initiator together with the cross-linking agent. Is one of the common methods.

The liquid absorbing resin may further contain a charge control agent for electrophotographic toner such as low molecular quaternary ammonium salts, organic borates, and salt-forming compounds of salicylic acid derivatives. The conductivity is controlled by conductivity such as tin oxide or titanium oxide (where conductivity means, for example, a volume resistivity of less than 10 ⁷ Ω · cm. The same applies hereinafter unless otherwise specified.) , Semiconductive (here, semiconductive means, for example, a volume resistivity of 10 ⁷ Ωcm or more and 10 ¹³ Ωcm or less. The same applies hereinafter unless otherwise specified). is there.

  The liquid absorbent resin is preferably an amorphous resin, and the glass transition temperature (Tg) thereof is, for example, 40 ° C. or higher and 90 ° C. or lower. The glass transition temperature (and melting point) was determined from the main maximum peak measured according to ASTM D3418-8. DSC-7 manufactured by Perkin Elmer Co. can be used for measurement of the main maximum peak. The temperature correction of the detection part of this apparatus uses the melting point of indium and zinc, and the correction of heat quantity uses the heat of fusion of indium. As the sample, an aluminum pan was used, an empty pan was set as a control, and the measurement was performed at a heating rate of 10 ° C./min.

  The weight average molecular weight of the liquid absorbent resin is, for example, from 3000 to 300,000. The weight average molecular weight is measured under the following conditions. For example, GPC uses “HLC-8120GPC, SC-8020 (manufactured by Tosoh Corporation)” apparatus, and two columns are “TSKgel, SuperHM-H (6.0 mm ID × 15 cm, manufactured by Tosoh Corporation)”. And THF (tetrahydrofuran) was used as the eluent. As experimental conditions, a sample concentration of 0.5% and a flow rate of 0.6 ml / min. The experiment was conducted using a sample injection amount of 10 μl, a measurement temperature of 40 ° C., and an IR detector. The calibration curve is “polystylen standard sample TSK standard” manufactured by Tosoh Corporation: “A-500”, “F-1”, “F-10”, “F-80”, “F-380”, “A-2500”. ”,“ F-4 ”,“ F-40 ”,“ F-128 ”, and“ F-700 ”.

  Examples of the acid value of the liquid absorbent resin include 50 mg KOH / g or more and 777 mg KOH / g or less in terms of carboxylic acid group (—COOH). The acid value in terms of this carboxylic acid group (—COOH) was measured as follows.

  The acid value was measured according to JIS K0070 and using a neutralization titration method. That is, an appropriate amount of a sample is taken, 100 ml of a solvent (diethyl ether / ethanol mixed solution) and a few drops of an indicator (phenolphthalein solution) are added, and shaken sufficiently until the sample is dissolved on a water bath. This was titrated with a 0.1 mol / l potassium hydroxide ethanol solution, and the end point was when the red color of the indicator lasted for 30 seconds. When the acid value is A, the sample amount is S (g), the 0.1 mol / l potassium hydroxide ethanol solution used for the titration is B (ml), and f is the factor of the 0.1 mol / l potassium hydroxide ethanol solution. , A = (B × f × 5.611) / S.

  The liquid-absorbing resin described above is used with the ratio of the polar monomer being controlled within the above range regardless of the form.

  The particle diameter of the hydrophilic organic particles is, for example, from 0.1 μm to 50 μm (preferably from 0.5 μm to 25 μm, more preferably from 1 μm to 10 μm) when the primary particle is the mother particle. Range. On the other hand, when composing the composite particle, for example, a range of 10 nm to 30 μm (desirably 50 nm to 10 μm, more desirably 0.1 μm to 5 μm) in terms of a sphere equivalent sphere diameter can be mentioned.

  The ratio of the hydrophilic organic particles to the whole ink-receiving particles is, for example, in the range of 75% or more, desirably 85% or more, and more desirably 90% or more and 99% or less.

  Next, the inorganic particles constituting the composite particles together with the hydrophilic organic particles and the inorganic particles attached to the mother particles will be described. As the inorganic particles, any of non-porous particles and porous particles can be used. Examples of the inorganic particles include colorless, light-colored or white particles (for example, colloidal silica, alumina, calcium carbonate, zinc oxide, titanium oxide, tin oxide, etc.). These inorganic particles may be subjected to surface treatment (partial hydrophobization treatment, specific functional group introduction treatment, etc.). For example, in the case of silica, the hydroxyl group of silica is treated with a silylating agent such as trimethylchlorosilane or t-butyldimethylchlorosilane to introduce an alkyl group. Hydrochloric acid is generated by the silylating agent, and the reaction proceeds. At this time, if amine is added, hydrochloric acid can be converted into hydrochloride to promote the reaction. It can be controlled by controlling the treatment amount and treatment conditions of a silane coupling agent having an alkyl group or a phenyl group as a hydrophobic group or a coupling agent such as titanate or zirconate. Further, surface treatment with aliphatic alcohols, higher fatty acids and derivatives thereof is also possible. Also, coupling agents having a cationic functional group such as a (substituted) amino group or a silane coupling agent having a quaternary ammonium salt structure, coupling agents having a fluorine-based functional group such as fluorosilane, and other carboxylic acids Surface treatment with a coupling agent having an anionic functional group such as the above is also possible. These inorganic particles may be so-called internally added contained in the hydrophilic organic particles.

  The particle diameter of the inorganic particles constituting the composite particles may be, for example, in the range of 10 nm to 30 μm (desirably 50 nm to 10 μm, more desirably 0.1 μm to 5 μm) in terms of a sphere equivalent sphere. On the other hand, the particle diameter of the inorganic particles attached to the mother particles is, for example, in the range of 10 nm to 1 μm (preferably 10 nm to 0.1 μm, more preferably 10 nm to 0.05 μm) in terms of sphere equivalent sphere. .

  Next, other additives for the ink receiving particles will be described. First, it is desirable that the ink receiving particles include a component that aggregates or thickens the components of the ink.

  The component having this function may be included as a functional group of a resin (resin water-absorbing resin) constituting the liquid-absorbent resin particles, or may be included as a compound. Examples of the functional group include carboxylic acids, polyvalent metal cations, polyamines, and the like.

  Moreover, as the said compound, flocculants, such as an inorganic electrolyte, an organic acid, an inorganic acid, and an organic amine, are mentioned suitably.

  Inorganic electrolytes include alkali metal ions such as lithium ion, sodium ion, potassium ion, aluminum ion, barium ion, calcium ion, copper ion, iron ion, magnesium ion, manganese ion, nickel ion, tin ion, titanium ion, zinc Polyvalent metal ions such as ions, hydrochloric acid, odorous acid, hydroiodic acid, sulfuric acid, nitric acid, phosphoric acid, thiocyanic acid, and acetic acid, succinic acid, lactic acid, fumaric acid, fumaric acid, citric acid, salicylic acid, benzoic acid And the like, and organic carboxylic acids such as salts of organic sulfonic acids.

  Specific examples include lithium chloride, sodium chloride, potassium chloride, sodium bromide, potassium bromide, sodium iodide, potassium iodide, sodium sulfate, potassium nitrate, sodium acetate, potassium oxalate, sodium citrate, potassium benzoate and the like. Alkali metal salts and aluminum chloride, aluminum bromide, aluminum sulfate, aluminum nitrate, sodium aluminum sulfate, potassium aluminum sulfate, aluminum acetate, barium chloride, barium bromide, barium iodide, barium oxide, barium nitrate, thiocyanate Barium acid, calcium chloride, calcium bromide, calcium iodide, calcium nitrite, calcium nitrate, calcium dihydrogen phosphate, calcium thiocyanate, calcium benzoate, calcium acetate, salicylic acid Lucium, calcium tartrate, calcium lactate, calcium fumarate, calcium citrate, copper chloride, copper bromide, copper sulfate, copper nitrate, copper acetate, iron chloride, iron bromide, iron iodide, iron sulfate, iron nitrate, oxalic acid Iron, iron lactate, iron fumarate, iron citrate, magnesium chloride, magnesium bromide, magnesium iodide, magnesium sulfate, magnesium nitrate, magnesium acetate, magnesium lactate, manganese chloride, manganese sulfate, manganese nitrate, manganese dihydrogen phosphate , Manganese acetate, manganese salicylate, manganese benzoate, manganese lactate, nickel chloride, nickel bromide, nickel sulfate, nickel nitrate, nickel acetate, tin sulfate, titanium chloride, zinc chloride, zinc bromide, zinc sulfate, zinc nitrate, thiocyanate Examples thereof include salts of polyvalent metals such as zinc acid and zinc acetate.

  Specific examples of organic acids include arginic acid, citric acid, glycine, glutamic acid, succinic acid, tartaric acid, cysteine, oxalic acid, fumaric acid, phthalic acid, maleic acid, malonic acid, lysine, malic acid, and general formula Examples thereof include compounds represented by (1) and derivatives of these compounds.

Here, in the formula, X represents O, CO, NH, NR ¹ , S, or SO ₂ . R ¹ represents an alkyl group, and R ¹ is preferably CH ₂ , C ₂ H ₅ , or C ₂ H ₄ OH. R represents an alkyl group, and R is preferably CH ₂ , C ₂ H ₅ , or C ₂ H ₄ OH. In addition, R may be included in the formula or may not be included. X is preferably CO, NH, NR, O, and more preferably CO, NH, O. M represents a hydrogen atom, an alkali metal or an amine. M is preferably H, Li, Na, K, monoethanolamine, diethanolamine, triethanolamine or the like, more preferably H, Na, K, and still more preferably a hydrogen atom. n is an integer of 3 to 7. n is preferably a case where the heterocyclic ring is a 6-membered ring or a 5-membered ring, and more preferably a 5-membered ring. m is 1 or 2. The compound represented by the general formula (1) may be a saturated ring or an unsaturated ring as long as it is a heterocyclic ring. l is an integer of 1 to 5.

  Specifically, the compound represented by the general formula (1) has a furan, pyrrole, pyrroline, pyrrolidone, pyrone, pyrrole, thiophene, indole, pyridine, quinoline structure, and further has a carboxyl group as a functional group. Compounds. Specifically, 2-pyrrolidone-5-carboxylic acid, 4-methyl-4-pentanolide-3-carboxylic acid, furan carboxylic acid, 2-benzofuran carboxylic acid, 5-methyl-2-furan carboxylic acid, 2,5 -Dimethyl-3-furancarboxylic acid, 2,5-furandicarboxylic acid, 4-butanolide-3-carboxylic acid, 3-hydroxy-4-pyrone-2,6-dicarboxylic acid, 2-pyrone-6-carboxylic acid, 4-pyrone-2-carboxylic acid, 5-hydroxy-4-pyrone-5-carboxylic acid, 4-pyrone-2,6-dicarboxylic acid, 3-hydroxy-4-pyrone-2,6-dicarboxylic acid, thiophenecarboxylic Acid, 2-pyrrolecarboxylic acid, 2,3-dimethylpyrrole-4-carboxylic acid, 2,4,5-trimethylpyrrole-3-propionic acid, 3-hydroxy-2-yne Carboxylic acid, 2,5-dioxo-4-methyl-3-pyrroline-3-propionic acid, 2-pyrrolidinecarboxylic acid, 4-hydroxyproline, 1-methylpyrrolidine-2-carboxylic acid, 5-carboxy-1-methyl Pyrrolidine-2-acetic acid, 2-pyridinecarboxylic acid, 3-pyridinecarboxylic acid, 4-pyridinecarboxylic acid, pyridinedicarboxylic acid, pyridinetricarboxylic acid, pyridinepentacarboxylic acid, 1,2,5,6-tetrahydro-1-methyl Examples include nicotinic acid, 2-quinolinecarboxylic acid, 4-quinolinecarboxylic acid, 2-phenyl-4-quinolinecarboxylic acid, 4-hydroxy-2-quinolinecarboxylic acid, and 6-methoxy-4-quinolinecarboxylic acid. .

  As the organic acid, desirably, citric acid, glycine, glutamic acid, succinic acid, tartaric acid, phthalic acid, pyrrolidone carboxylic acid, pyrone carboxylic acid, pyrrole carboxylic acid, furan carboxylic acid, pyridine carboxylic acid, coumaric acid, thiophene carboxylic acid, Nicotinic acid, derivatives of these compounds, or salts thereof. More desirably, pyrrolidone carboxylic acid, pyrone carboxylic acid, pyrrole carboxylic acid, furan carboxylic acid, pyridine carboxylic acid, coumaric acid, thiophene carboxylic acid, nicotinic acid, or derivatives of these compounds, or salts thereof. More desirable are pyrrolidone carboxylic acid, pyrone carboxylic acid, furan carboxylic acid, coumaric acid, or a derivative of these compounds, or a salt thereof.

  The organic amine compound may be any of primary, secondary, tertiary and quaternary amines and salts thereof. Specific examples include tetraalkylammonium, alkylamine, benzalkonium, alkylpyridium, imidazolium, polyamine, and derivatives or salts thereof. Specifically, amylamine, butylamine, propanolamine, propylamine, ethanolamine, ethylethanolamine, 2-ethylhexylamine, ethylmethylamine, ethylbenzylamine, ethylenediamine, octylamine, oleylamine, cyclooctylamine, cyclobutylamine, cyclohexane Propylamine, cyclohexylamine, diisopropanolamine, diethanolamine, diethylamine, di-2-ethylhexylamine, diethylenetriamine, diphenylamine, dibutylamine, dipropylamine, dihexylamine, dipentylamine, 3- (dimethylamino) propylamine, dimethylethylamine, dimethyl Ethylenediamine, dimethyloctylamine, 1,3-dimethylbutylamine, dimethyl 1,3-propanediamine, dimethylhexylamine, amino-butanol, amino-propanol, amino-propanediol, N-acetylaminoethanol, 2- (2-aminoethylamino) -ethanol, 2-amino-2- Ethyl-1,3-propanediol, 2- (2-aminoethoxy) ethanol, 2- (3,4-dimethoxyphenyl) ethylamine, cetylamine, triisopropanolamine, triisopentylamine, triethanolamine, trioctylamine, Tritylamine, bis (2-aminoethyl) 1,3-propanediamine, bis (3-aminopropyl) ethylenediamine, bis (3-aminopropyl) 1,3-propanediamine, bis (3-aminopropyl) methylamine, Bis (2-ethylhexyl ) Amine, bis (trimethylsilyl) amine, butylamine, butylisopropylamine, propanediamine, propyldiamine, hexylamine, pentylamine, 2-methyl-cyclohexylamine, methyl-propylamine, methylbenzylamine, monoethanolamine, laurylamine, Nonylamine, trimethylamine, triethylamine, dimethylpropylamine, propylenediamine, hexamethylediamine, tetraethylenepentamine, diethylethanolamine, tetramethylammonium chloride, tetraethylammonium bromide, dihydroxyethylstearylamine, 2-heptadecenyl-hydroxyethylimidazoline, lauryl Dimethylbenzylammonium chloride, cetylpyridinium mouth Ride, stearamide methylbiridium chloride, diallyldimethylammonium chloride polymer, diallylamine polymer, monoallylamine polymer and the like can be mentioned.

  More desirably, triethanolamine, triisopropanolamine, 2-amino-2-ethyl-1,3-propanediol, ethanolamine, propanediamine, propylamine and the like are used.

Among these flocculants, polyvalent metal salts (Ca (NO ₃ ), Mg (NO ₃ ), Al (OH ₃ ), polyaluminum chloride, etc.) are preferably used.

  The flocculant may be used alone or in combination of two or more. Moreover, as content of a flocculant, it is desirable that it is 0.01 to 30 mass%. More preferably, it is 0.1 mass% or more and 15 mass% or less, More preferably, it is 1 mass% or more and 15 mass% or less.

  The ink receiving particles preferably contain a release agent. The release agent may be included in the liquid-absorbent resin, or the release agent particles may be combined with the hydrophilic organic resin particles.

  Examples of the mold release agent include low molecular weight polyolefins such as polyethylene, polypropylene, and polybutene; silicones having a softening point by heating; fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide, and stearic acid amide. Plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil; animal waxes such as beeswax; minerals such as montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, and Fischer-Tropsch wax -Petroleum wax; and modified products thereof. Among these, it is preferable to apply a crystalline compound.

<Ink>
Hereinafter, the ink applied in the above embodiment will be described in detail. Water-based ink is used as the ink. Aqueous ink (hereinafter simply referred to as ink) contains an ink solvent (for example, water, a water-soluble organic solvent) in addition to the recording material. In addition, other additives may be included as necessary.

  First, the recording material will be described. As the recording material, a color material is mainly used. As the color material, either a dye or a pigment can be used, but a pigment is preferable. As the pigment, either an organic pigment or an inorganic pigment can be used. Examples of the black pigment include carbon black pigments such as furnace black, lamp black, acetylene black, and channel black. In addition to black, cyan, magenta, and yellow primary pigments, specific color pigments such as red, green, blue, brown, and white, metallic luster pigments such as gold and silver, colorless or light color extender pigments, plastic pigments, etc. May be used. In addition, a newly synthesized pigment may be used for the present invention.

  It is also possible to use particles, such as silica, alumina, polymer beads, etc., having a dye or pigment fixed on the surface thereof, a dye insoluble lake, a colored emulsion, or a colored latex as the pigment.

  Specific examples of black pigments include Raven7000, Raven5750, Raven5250, Raven5000 ULTRAII, Raven3500, Raven2000, Raven1500, Raven1250, Raven1200, Raven1125, Raven10, Raven10, Raven10 Regal 330R, Regal 660R, Mogul L, Black Pearls L, Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 140 0 (manufactured by Cabot Corporation), Color Black FW1, Color Black FW2, Color Black FW2V, Color Black 18, Color Black FW200, Color Black S150, Color Black P160, Color Black P160, Color Black FW2V, Color Black FW2V, Color Black FW200, Color Black FW200 Printex 140V, Special Black 6, Special Black 5, Special Black 4A, Special Black 4 (manufactured by Degussa), No. 25, no. 33, no. 40, no. 47, no. 52, no. 900, no. 2300, MCF-88, MA600, MA7, MA8, MA100 (manufactured by Mitsubishi Chemical Corporation) and the like can be mentioned, but are not limited thereto.

  Specific examples of the cyan pigment include C.I. I. Pigment Blue-1, -2, -3, -15, -15: 1, -15: 2, -15: 3, -15: 4, -16, -22, -60, and the like. It is not limited.

  Specific examples of the magenta color pigment include C.I. I. Pigment Red-5, -7, -12, -48, -48: 1, -57, -112, -122, -123, -146, -168, -177, -184, -202, C.I. I. Pigment Violet-19 etc. are mentioned, However, It is not limited to these.

  Specific examples of yellow pigments include C.I. I. Pigment Yellow-1, -2, -3, -12, -13, -14, -16, -17, -73, -74, -75, -83, -93, -95, -97, -98, -114, -128, -129, -138, -151, -154, -180, and the like, but are not limited thereto.

  Here, when a pigment is used as the color material, it is desirable to use a pigment dispersant together. Examples of the pigment dispersant that can be used include a polymer dispersant, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant.

  As the polymer dispersant, a polymer having a hydrophilic structure portion and a hydrophobic structure portion is preferably used. As the polymer having a hydrophilic structure portion and a hydrophobic structure portion, a condensation polymer and an addition polymer can be used. Examples of the condensation polymer include known polyester dispersants. Examples of the addition polymer include addition polymers of monomers having an α, β-ethylenically unsaturated group. Desired polymer dispersion by copolymerizing a monomer having an α, β-ethylenically unsaturated group having a hydrophilic group and a monomer having an α, β-ethylenically unsaturated group having a hydrophobic group An agent is obtained. A homopolymer of a monomer having an α, β-ethylenically unsaturated group having a hydrophilic group can also be used.

  Monomers having an α, β-ethylenically unsaturated group having a hydrophilic group include monomers having a carboxyl group, a sulfonic acid group, a hydroxyl group, a phosphoric acid group, such as acrylic acid, methacrylic acid, and crotonic acid. , Itaconic acid, itaconic acid monoester, maleic acid, maleic acid monoester, fumaric acid, fumaric acid monoester, vinyl sulfonic acid, styrene sulfonic acid, sulfonated vinyl naphthalene, vinyl alcohol, acrylamide, methacryloxyethyl phosphate, bismethacrylic acid Examples include roxyethyl phosphate, methacrylooxyethyl phenyl acid phosphate, ethylene glycol dimethacrylate, and diethylene glycol dimethacrylate.

  Examples of the monomer having an α, β-ethylenically unsaturated group having a hydrophobic group include styrene derivatives such as styrene, α-methylstyrene, vinyltoluene, vinylcyclohexane, vinylnaphthalene, vinylnaphthalene derivatives, alkyl acrylate esters, Examples include methacrylic acid alkyl esters, methacrylic acid phenyl esters, methacrylic acid cycloalkyl esters, crotonic acid alkyl esters, itaconic acid dialkyl esters, maleic acid dialkyl esters, and the like.

  Examples of desirable copolymers used as polymer dispersants include styrene-styrene sulfonic acid copolymers, styrene-maleic acid copolymers, styrene-methacrylic acid copolymers, styrene-acrylic acid copolymers, Vinyl naphthalene-maleic acid copolymer, vinyl naphthalene-methacrylic acid copolymer, vinyl naphthalene-acrylic acid copolymer, alkyl acrylate ester-acrylic acid copolymer, alkyl methacrylate ester-methacrylic acid copolymer, styrene -Methacrylic acid alkyl ester-Methacrylic acid copolymer, Styrene-Acrylic acid alkyl ester-Acrylic acid copolymer, Styrene-Methacrylic acid phenyl ester-Methacrylic acid copolymer, Styrene-Methacrylic acid cyclohexyl ester-Methacrylic acid copolymer Etc. . Moreover, you may copolymerize the monomer which has a polyoxyethylene group and a hydroxyl group with these polymers.

  Examples of the polymer dispersant include those having a weight average molecular weight of 2,000 to 50,000.

  These pigment dispersants may be used alone or in combination of two or more. The amount of the pigment dispersant added varies greatly depending on the pigment, so it cannot be generally stated.

  A pigment that can be self-dispersed in water can also be used as the color material. A pigment that can be self-dispersed in water refers to a pigment that has many water-solubilizing groups on the surface of the pigment and disperses in water without the presence of a polymer dispersant. Specifically, it can be self-dispersed in water by subjecting ordinary so-called pigments to surface modification treatments such as acid / base treatment, coupling agent treatment, polymer graft treatment, plasma treatment, oxidation / reduction treatment, etc. Pigments are obtained.

  Further, as pigments that can be self-dispersed in water, in addition to pigments obtained by subjecting the above pigments to surface modification treatment, Cab-o-jet-200, Cab-o-jet-300, IJX- manufactured by Cabot Corporation Commercially available self-dispersing pigments such as 157, IJX-253, IJX-266, IJX-273, IJX-444, IJX-55, Cabot 260, Microjet Black CW-1, CW-2 manufactured by Orient Chemical Co., etc. can also be used.

  The self-dispersing pigment is desirably a pigment having at least sulfonic acid, sulfonate, carboxylic acid, or carboxylate as a functional group on the surface thereof. More desirably, the pigment has at least a carboxylic acid or a carboxylate as a functional group on the surface.

  Furthermore, a pigment coated with a resin can also be used. This is called a microcapsule pigment, and not only commercially available microcapsule pigments manufactured by Dainippon Ink and Chemicals, Inc., or Toyo Ink, but also microcapsule pigments produced for the present invention may be used. it can.

In addition, a resin-dispersed pigment in which a polymer substance is physically adsorbed or chemically bonded to the pigment can also be used.

  Other recording materials include hydrophilic anionic dyes, direct dyes, cationic dyes, reactive dyes, dyes such as polymer dyes and oil-soluble dyes, wax powders / resin powders and emulsions colored with dyes, Fluorescent dyes and fluorescent pigments, infrared absorbers, ultraviolet absorbers, magnetic materials such as ferromagnetic materials represented by ferrite and magnetite, semiconductors and photocatalysts represented by titanium oxide and zinc oxide, and other organic and inorganic electrons Examples include material particles.

  The content (concentration) of the recording material is, for example, 5% by mass to 30% by mass with respect to the ink.

  The volume sphere equivalent diameter of the recording material is, for example, 10 nm or more and 1000 nm or less.

  The volume sphere equivalent diameter of the recording material refers to the particle size of the recording material itself, or the particle size to which the additive has adhered when an additive such as a dispersant is attached to the recording material. A Microtrac UPA particle size analyzer 9340 (manufactured by Lees & Northrup) was used as the measuring device for the volume sphere equivalent diameter. The measurement was performed according to a predetermined measurement method with 4 ml of ink placed in a measurement cell. As input values at the time of measurement, the viscosity of the ink was used as the viscosity, and the density of the dispersed particles was used as the density of the recording material.

  Next, the water-soluble organic solvent will be described. As the water-soluble organic solvent, polyhydric alcohols, polyhydric alcohol derivatives, nitrogen-containing solvents, alcohols, sulfur-containing solvents and the like are used.

  Specific examples of the water-soluble organic solvent include polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,5-pentanediol, 1,2-hexanediol, 1,2, Examples thereof include sugar alcohols such as 6-hexanetriol, glycerin, trimethylolpropane, and xylitol, and sugars such as xylose, glucose, and galactose.

  Polyhydric alcohol derivatives include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, diglycerin. And ethylene oxide adducts.

Examples of the nitrogen-containing solvent include pyrrolidone, N-methyl-2-pyrrolidone, cyclohexyl pyrrolidone, and triethanolamine. Examples of the alcohol include alcohols such as ethanol, isopropyl alcohol, butyl alcohol, and benzyl alcohol.
Examples of the sulfur-containing solvent include thiodiethanol, thiodiglycerol, sulfolane, dimethyl sulfoxide and the like.

  In addition, as the water-soluble organic solvent, propylene carbonate, ethylene carbonate, or the like can be used.

  At least one kind of water-soluble organic solvent may be used. As content of a water-soluble organic solvent, 1 mass% or more and 70 mass% or less are mentioned, for example.

  Next, water will be described. As water, it is desirable to use ion-exchanged water, ultrapure water, distilled water, or ultrafiltered water in order to prevent impurities from being mixed.

  Next, other additives will be described. A surfactant can be added to the ink.

  Examples of these surfactants include various anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, and the like. Desirably, anionic surfactants and nonionic surfactants are used. An activator is used.

Specific examples of the surfactant are listed below.
Examples of the anionic surfactant include alkylbenzene sulfonate, alkylphenyl sulfonate, alkylnaphthalene sulfonate, higher fatty acid salt, sulfate of higher fatty acid ester, sulfonate of higher fatty acid ester, sulfuric acid of higher alcohol ether. Ester salts and sulfonates, higher alkyl sulfosuccinates, polyoxyethylene alkyl ether carboxylates, polyoxyethylene alkyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates can be used, preferably , Dodecylbenzenesulfonate, isopropylnaphthalenesulfonate, monobutylphenylphenol monosulfonate, monobutylbiphenylsulfonate, monobutylbiphenylsulfonate, dibutylphenylsulfonate Nord disulfonic acid salts and the like are used.

  Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid esters, poly Oxyethylene glycerin fatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, polyoxyethylene alkylamine, polyoxyethylene fatty acid amide, alkyl alkanolamide, polyethylene glycol polypropylene glycol block copolymer, acetylene glycol, polyoxyethylene adduct of acetylene glycol Desirably, polyoxyethylene nonyl pheny is preferable. Ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, fatty acid alkylolamide, polyethylene glycol polypropylene glycol block copolymer Acetylene glycol and polyoxyethylene adducts of acetylene glycol are used.

  In addition, silicone surfactants such as polysiloxane oxyethylene adducts, fluorine surfactants such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and oxyethylene perfluoroalkyl ethers, spicrispolic acid and rhamnolipids Biosurfactants such as lysolecithin can also be used.

  These surfactants may be used alone or in combination. The hydrophilic / hydrophobic balance (HLB) of the surfactant is preferably in the range of 3 to 20 in consideration of solubility and the like.

  The addition amount of these surfactants is preferably 0.001% by mass to 5% by mass, and particularly preferably 0.01% by mass to 3% by mass.

  In addition, the ink has other properties such as polyethyleneimine, polyamines, polyvinylpyrrolidone, polyethyleneglycol, ethylcellulose, carboxymethylcellulose, etc. for the purpose of controlling properties such as penetrants and ink ejection improvement for the purpose of adjusting permeability. In order to adjust pH, compounds of alkali metals such as potassium hydroxide, sodium hydroxide, lithium hydroxide, etc., pH buffer, antioxidant, antifungal agent, viscosity adjuster, conductive agent as necessary UV absorbers, chelating agents, and the like can also be added.

  Next, preferred characteristics of the ink will be described. First, the surface tension of the ink is 20 mN / m or more and 45 mN / m or less.

  Here, as the surface tension, a value measured in an environment of 23 ° C. and 55% RH using a Wilhelmy type surface tension meter (manufactured by Kyowa Interface Science Co., Ltd.) was adopted.

  The viscosity of the ink may be from 1.5 mPa · s to 30 mPa · s.

Here, as the viscosity, a value measured using a rheomat 115 (manufactured by Contraves) as a measuring device under the conditions of a measurement temperature of 23 ° C. and a shear rate of 1400 s ⁻¹ was adopted.

  The ink is not limited to the above configuration. In addition to the recording material, for example, a functional material such as a liquid crystal material or an electronic material may be included.

  In the present embodiment, the ink droplets 20A are selectively ejected from the inkjet recording heads 20 of black, yellow, magenta, and cyan based on the image data so that a full color image is recorded on the recording medium 8. However, the present invention is not limited to recording characters and images on a recording medium. That is, the apparatus according to the present invention is applied to all the droplet discharge (jetting) apparatuses used industrially.

(Second Embodiment)
In the first embodiment, the case where a plurality of types of ink receptive particles (ink receptive particles 16A and ink receptive particles 16B) having different softening temperatures is used as the ink receptive particles 16 has been described. In this embodiment, a case where a plurality of types of ink receiving particles 50 (see FIG. 6) having different degrees of neutralization are used as the ink receiving particles will be described.

  As shown in FIGS. 6 and 7, the recording apparatus 11 according to the present embodiment includes an endless belt-like intermediate transfer body 12. The intermediate transfer body 12 is provided so as to move in the moving direction (the arrow A direction in FIG. 1). In the vicinity of the intermediate transfer body 12, an ink receiving unit that receives ink in a charged region on the release agent supply device 14, the charging device 28, and the intermediate transfer body 12 in order along the moving direction of the intermediate transfer body 12. Supply device 60 for supplying a plurality of types of ink receptive particles 50 having different neutralization levels to each other in layers to form a particle stack 70 on the intermediate transfer body 12, and a particle stack 70 An ink jet recording head 20 that ejects ink droplets 20A thereon, a transfer device that transfers the particle stack 70 onto the recording medium 8 by superposing the recording medium 8 on the intermediate transfer body 12 and applying pressure or pressure and heat. 22 are arranged in order. The recording apparatus 11 includes a fixing device 25 that fixes the particle stack 70 to the recording medium 8 by applying pressure and heat to the particle stack 70, a cleaning device 24, and a charge removal device 29.

  The recording apparatus 11 described in the present embodiment is replaced with the ink receiving particles 16 used in the recording apparatus 10 described in the first embodiment, and a plurality of types of ink receiving particles having different degrees of neutralization. 50, and in place of the particle supply device 18 in the recording apparatus 10 described in the first embodiment, a particle supply device 60 for supplying the ink receiving particles 50 onto the intermediate transfer body 12 is provided. The recording apparatus 10 has substantially the same configuration and function as the recording apparatus 10 described in the first embodiment except that the particle stack 70 is formed on the intermediate transfer body 12 instead of the particle stack 40. The same reference numerals are given to the same parts, and detailed description is omitted.

  The ink receiving particles 50 are composed of a plurality of types of ink receiving particles 50 having different degrees of neutralization. In the present embodiment, in order to simplify the description, as two types of ink receiving particles 50 having different degrees of neutralization, ink receiving particles 50A and ink receiving properties having a higher degree of neutralization than ink receiving particles 50A. Although the case where particle 50B is used is explained, it is not restricted to two kinds.

  The material constituting each of the ink receptive particles 50 and the shape thereof are selected from the same materials and materials as those described with reference to FIGS. 10 and 11 in the first embodiment. Is omitted.

  The particle supply device 60 is provided upstream of the inkjet recording head 20 in the moving direction of the intermediate transfer body 12 (in the direction of arrow A in FIG. 6). The particle supply device 60 supplies a plurality of types of ink receptive particles 50 having different degrees of neutralization on the intermediate transfer body 12 by laminating each type of ink receptive particles 50 in layers. On the transfer body 12, a particle laminated body 70 is formed by a plurality of types of ink receiving particles 50 having different neutralization degrees.

  As shown in FIGS. 7 and 8A, the particle supply device 60 is a layer (hereinafter referred to as the intermediate transfer member 12) closest to the intermediate transfer member 12 among the layers of the particle laminate 70 formed on the intermediate transfer member 12. The ink receiving particles constituting the layer 51B (hereinafter, appropriately referred to as the second layer) in which the degree of neutralization of the ink receiving particles 50A constituting the 51A (referred to as the first layer as appropriate) is farthest from the intermediate transfer body 12 is referred to. Each type of ink receiving particles 50 (ink receiving particles 50A and ink receiving particles 50B) is supplied onto the intermediate transfer body 12 so as to be lower than the neutralization degree of the photosensitive particles 50B.

  The particle supply device 60 includes a plurality of particle supply devices. In the present embodiment, in order to simplify the description, it is assumed that two types (ink receiving particles 50A and ink receiving particles 50B) are used as the plurality of types of ink receiving particles 50 having different degrees of neutralization. The particle supply device 60 includes a particle supply device 60A and a particle supply device 60B. The particle supply device 60A and the particle supply device 60B are arranged along the moving direction of the intermediate transfer body 12 (the direction of arrow A in FIG. 6), and the particle supply device 60A is more intermediate than the particle supply device 60B. It is provided upstream of the transfer body 12 in the moving direction.

  Among the particle supply device 60A and the particle supply device 60B, the particle supply device 60A provided on the upstream side in the moving direction of the intermediate transfer body 12 from the particle supply device 60B is downstream so as to form the first layer 51A. The ink receiving particles 50A having a lower neutralization degree are supplied than the particle supply device 60B provided on the side. Then, the particle supply device 60B supplies the ink receiving particles 50B having a higher degree of neutralization than the particle supply device 60A so as to form the second layer 51B. As a result, on the intermediate transfer body 12, a particle laminate 70 is formed in which the second layer 51B made of the ink receiving particles 50B is laminated on the first layer 51A made of the ink receiving particles 50A.

The degree of neutralization of the ink receiving particles 50A supplied to the side closest to the intermediate transfer body 12 by the particle supply device 60A is supplied to the side farthest from the intermediate transfer body 12 side (discharge surface on which ink droplets are discharged). It is essential that the layer has a lower neutralization degree than the ink receiving particles 50B.
For reasons of both improved transferability and storability, the neutralization degree of the ink receiving particles 50B is preferably 10% or more, more preferably 20% or more.

  Specifically, the degree of neutralization of the ink receiving particles 50A is preferably 30% or less, more preferably 20% or less, and particularly preferably 10% or less.

In the present embodiment, the method for measuring the neutralization degree of the ink receiving particles 50 (ink receiving particles 50A and ink receiving particles 50B) is not particularly limited as long as the measuring method has a certain reproducibility. Although not, for example, neutralizing titration of ink receiving particles with KOH to measure the amount of (COOH), then titrating the neutralized material with HCl to measure the amount of (COO ⁻ ) It is calculated by the formula of “sum == (COO ⁻ ) / (COOH)”.
Specifically, after the ink receiving particles are dissolved in an IPA / water mixed solvent, the consumption amount of KOH is determined according to the acid value potentiometry method of JIS K2501 (potentiometer and pH meter are used for measurement). Measure and calculate the molar amount of (COOH). Next, the ink-receptive particles after neutralization are dissolved in an IPA / water mixed solvent, HClaq is used as a titration solution, and an acid value potentiometric method of JIS K2501 (a potentiometer and a pH meter are used for measurement). Similarly, the amount of HCl consumed is measured to calculate the molar amount of (COO ⁻ ). From these, the neutralization degree is calculated by the above formula.

  On the other hand, the neutralization degree of the ink receiving particles 50B supplied to the side farthest from the intermediate transfer body 12 by the particle supply device 60B (the layer serving as the discharge surface from which the ink droplets are discharged) is the most intermediate as described above. It is essential that the degree of neutralization of the ink receiving particles 16A supplied to the side close to the transfer body 12 is higher.

  The degree of neutralization of the ink receptive particles 50B is such that the softening temperature in the state after the ink receptive particles 50B receive the ink droplets 20A is water in order to achieve high transfer efficiency while suppressing image quality deterioration. The degree of neutralization is preferably such that the boiling point is 100 ° C. or lower. Further, the neutralization degree of the ink receiving particles 50B is more preferably in a state after the ink receiving particles 50B receive the ink droplets 20A from the viewpoint of realizing high-speed transfer and reduction of thermal energy applied during transfer. The degree of neutralization is preferably such that the softening temperature is less than 50 ° C., and more preferably less than 30 ° C. from the viewpoint of realizing high transfer efficiency of the particle laminate 40 to the recording medium 8 at room temperature (25 ° C.).

  Specifically, the degree of neutralization of the ink receiving particles 50B is preferably 30% or more, more preferably 40% or more, and particularly preferably 60% or more.

  As described above, the ink receptive particles 50A and the ink receptive particles 50B have the highest degree of neutralization of the ink receptive particles 50A supplied to the side closest to the intermediate transfer body 12 from the intermediate transfer body 12. The constituent material may be the same or different as long as it is higher than the neutralization degree of the ink receiving particles 50B supplied to the far side.

  By making the materials constituting the ink receiving particles 50A and the ink receiving particles 50B the same and adjusting only the composition ratio, both the ink receiving particles 50A and the ink receiving particles 50B can be obtained with simple manufacturing conditions and manufacturing steps. Is produced. Further, by using the same material for the ink receiving particles 50A and the ink receiving particles 50B, the particle stack 70 formed on the recording medium 8 is fixed to the recording medium 8 by the fixing device 25 (FIG. 9). When the reference material is used, the ink-receptive particles 50A and the ink-receptive particles 50B have better compatibility than the case where the constituent materials are different.

  In order to configure the neutralization degree of the ink receiving particles 50A and the ink receiving particles 50B to be different as described above, for example, the number of carboxylic acids present in the unneutralized receiving particles is For example, it is realized by adding and adjusting a neutralizing agent such as sodium hydroxide so as to obtain a desired degree of neutralization.

  In the particle supply device 60A for supplying the ink receiving particles 50A and the particle supply device 60B for supplying the ink receiving particles 50B, the ink receiving particles are supplied via the supply pipe 19A and the supply pipe 19B, respectively. The storage cartridge 21A and the ink receiving particle storage cartridge 21B are detachably connected.

  In the particle supply device 60A, ink receiving particles 50A supplied from the ink receiving particle storage cartridge 21A are stored. A supply roll 41A is arranged in a region of the particle supply apparatus 60A facing the intermediate transfer body 12, and a charging blade 42A is arranged so as to press the supply roll 41A. The charging blade 42A also has a function of regulating the layer thickness of the ink receiving particles 50A supplied to the surface of the supply roll 41A.

  The ink receiving particles 50A in the particle supply device 60A are supplied to the supply roll 41A (conductive roll), charged by the charging blade 42A, and supplied to the intermediate transfer body 12 (that is, the intermediate transfer body). The layer thickness when the toner is supplied in a layer form on the surface 12 is adjusted and supplied to the intermediate transfer member 12.

  The ink receiving particles 50A charged by the charging blade 42A are formed, for example, on the surface of the supply roll 41A as one layer (a layer corresponding to one particle, the same applies hereinafter), and face the surface of the intermediate transfer body 12 by the rotation of the supply roll 41A. The charged ink receiving particles 16A are moved to the surface of the intermediate transfer member 12 by electrostatic force due to the electric field formed by the potential difference between the supply roll 41A and the surface of the intermediate transfer member 12 (see FIGS. 6 and 6). 7 and FIG. 8 (A)).

  The supply amount of the ink receiving particles 50A supplied onto the intermediate transfer body 12 is preferably smaller than the supply amount of the ink receiving particles 50B. Furthermore, only the particles in contact with the surface of the intermediate transfer body 12 act to improve the transfer efficiency of the particle laminate 70 from the intermediate transfer body 12, and the cost of the particles and the energy required for fixing to the recording medium 8 are reduced. From the viewpoint of realization, approximately one layer is more preferable. The ink receiving particles 50 </ b> B supplied onto the intermediate transfer body 12 are not limited to being supplied in a layer form, and may be supplied so as to be scattered on the intermediate transfer body 12.

  The supply amount of the ink receiving particles 50A is adjusted by relatively setting the moving speed of the intermediate transfer body 12 and the rotation speed of the supply roll 41A (peripheral speed ratio) in the particle supply device 60A. This peripheral speed ratio depends on other parameters such as the charge amount of the intermediate transfer member 12, the charge amount of the ink receiving particles 50A, and the positional relationship between the supply roll 41A and the intermediate transfer member 12. The absolute value of the charge amount of the ink receiving particles 50A is desirably in the range of 5 μC / g to 50 μC / g.

  Similarly, the ink receiving particles 50B supplied from the ink receiving particle storage cartridge 21B are stored in the particle supply device 60B. A supply roll 41B is disposed in a region of the particle supply device 60B facing the intermediate transfer body 12, and a charging blade 42B is disposed so as to press the supply roll 41B. The charging blade 42B also has a function of regulating the layer thickness of the ink receiving particles 50B supplied to the surface of the supply roll 41B.

  The ink receiving particles 50B in the particle supply device 60B are supplied to the supply roll 41B (conductive roll), charged by the charging blade 42B, and supplied to the intermediate transfer body 12 (that is, the intermediate transfer body). The layer thickness when the toner is supplied in a layer form on the surface 12 is adjusted and supplied to the intermediate transfer member 12.

  The ink receiving particles 50B charged by the charging blade 42B are preferably formed on the surface of the supply roll 41B in a plurality of layers (a layer corresponding to a plurality of particles, the same applies hereinafter). The charged ink receiving particles 50B are transported to a region facing the surface of the intermediate transfer body 12 by the rotation of the supply roll 41B, and the charged ink receiving particles 50B are electrostatically charged by the electric field formed by the potential difference between the supply roll 41B and the surface of the intermediate transfer body 12. As a result, the intermediate transfer member 12 moves.

  At this time, since the first layer 51A is provided on the intermediate transfer body 12 with the ink receiving particles 50A already supplied in layers by the particle supply device 60A, the particle supply device 60B is provided with this ink receiving device. The ink receiving particles 50B are supplied so as to be laminated on the layer of the conductive particles 50A (the first layer 51A) (see FIGS. 6, 7, and 8B).

  The supply amount of the ink receiving particles 50B supplied onto the first layer 51A by the ink receiving particles 50A depends on the amount of the ink droplets 20A supplied from the ink jet recording head 20, but a plurality of layers are formed. It is preferable.

  For this purpose, the intermediate transfer body 12 is moved so that a particle layer (second layer 51B) is formed by a plurality of layers of ink receiving particles 50B on the first layer 51A of the ink receiving particles 50A. The speed and the rotation speed of the supply roll 41B may be set relatively (peripheral speed ratio). This peripheral speed ratio depends on other parameters such as the charge amount of the intermediate transfer member 12, the charge amount of the ink receiving particles 50B, and the positional relationship between the supply roll 41B and the intermediate transfer member 12.

  In the present embodiment, the particle stack 70 formed on the intermediate transfer member 12 by the particle supply device 60A and the particle supply device 60B is the first layer 51A that is the layer closest to the intermediate transfer member 12 side. In the following description, it is assumed that the second layer 51B is stacked on top of each other, but between the first layer 51A and the second layer 51B, the same as either the ink receiving particles 50A or the ink receiving particles 50B. A structure in which one layer or a plurality of layers of the ink receiving particles 50 having a neutralization degree different from the neutralization degree or the neutralization degree of both particles may be used.

In this case, although illustration is omitted, if the particle supply device 60 is not composed of the two particle supply devices 60A and 60B, but includes three or more particle supply devices. Good. In this case, three or more particle supply devices included in the particle supply device 60 are arranged along the movement direction of the intermediate transfer body 12 and the most upstream particle supply device in the movement direction of the intermediate transfer body 12. Is the particle supply device 60A described above, and the particle supply device on the most downstream side in the moving direction of the intermediate transfer body 12 is the particle supply device 60B described above.
In this case, even when the configuration includes three or more particle supply devices 60, the particle supply device 60 causes the layer (first layer 51A) closest to the intermediate transfer body 12 to receive ink. And a layer farthest from the intermediate transfer body 12 (second layer 51B), that is, a layer from which ink droplets are ejected is a layer composed of the ink receiving particles 50B. A particle laminated body 70 composed of a plurality of layers is formed on the intermediate transfer body 12.

In this way, the particle stack 70 is formed between the first layer 51A and the second layer 51B with the same neutralization degree as that of either the ink receiving particle 50A or the ink receiving particle 50B or both particles having the same degree. In the case where one or more layers of the ink receiving particles 50 having a degree of neutralization different from the degree of neutralization are laminated, the degree of neutralization from the first layer 51A toward the second layer 51B. It is preferable that a layer composed of smaller ink receiving particles 50 be stacked.
For example, when the difference in the degree of neutralization between the first layer 51A and the second layer 51B is large, when the particle laminate 70 is fixed to the recording medium 8, the compatibility of these two layers is low and the fixing performance is poor. In some cases, there is one layer of the ink-receptive particles 50 having a neutralization degree intermediate between the first layer 51A and the second layer 51B between the first layer 51A and the second layer 51B. Thus, the compatibility of the first layer 51A and the second layer 51B can be improved.

  Hereinafter, the image forming process of the recording apparatus 11 according to the present embodiment will be described in more detail.

  In the recording apparatus 11 according to this embodiment, as shown in FIGS. 6 and 7, a release layer 14 </ b> A is formed on the surface of the intermediate transfer body 12 by the release agent supply device 14. Next, the surface of the intermediate transfer member 12 is charged to a polarity opposite to that of the ink receiving particles 16 by the charging device 28.

  When the region charged by the charging device 28 on the intermediate transfer member 12 reaches the region where the particle supply device 60A is provided by the movement of the intermediate transfer member 12 in the moving direction, ink is supplied by the supply roll 41A of the particle supply device 60A. Receptive particles 50A are supplied in layers (see FIGS. 7 and 8A).

  As described above, the supply amount of the ink receiving particles 50A per unit area supplied to form the first layer 51A is supplied to form the second layer 51B to be stacked later. The amount of ink receiving particles 50B per unit area to be supplied is small and may be one layer or sparsely supplied. As described above, the supply amount of the ink receiving particles 50A is adjusted by the gap between the charging blade 42A and the supply roll 41A. The supply amount of the ink receiving particles 50A may be controlled by the peripheral speed ratio between the supply roll 41A and the intermediate transfer body 12.

When the region formed by the first layer 51A of the ink receiving particles 50A on the intermediate transfer body 12 reaches the region where the particle supply device 60B is provided by the movement of the intermediate transfer body 12 in the movement direction, The ink receiving particles 50B are supplied in layers by the supply roll 41B of the particle supply device 60B to form the second layer 51B (see FIGS. 7 and 8B).
Here, since the first layer 51A of the ink receiving particles 50A having a lower degree of neutralization than the ink receiving particles 50B is formed on the intermediate transfer body 12 by the particle supply device 60A, the particle supply device 60B. The ink receiving particles 50B supplied from is supplied so as to be laminated on the first layer 51A by the ink receiving particles 50A on the intermediate transfer body 12.

  As described above, the second layer 51B of the ink receiving particles 50B is preferably a plurality of layers. As described above, the layer thickness of the second layer 51B by the ink receiving particles 50B is adjusted by the gap between the charging blade 42B and the supply roll 41B. The layer thickness of the ink receiving particles 50B may be controlled by the peripheral speed ratio between the supply roll 41B and the intermediate transfer body 12.

  In this way, the first layer 51A composed of the ink receiving particles 50A is formed on the intermediate transfer body 12, and the degree of neutralization is higher on the first layer 51A than the ink receiving particles 50A. By forming the second layer 51B of the ink receiving particles 50B, the particle stack 70 is formed on the intermediate transfer body 12.

  When the area of the intermediate transfer body 12 on which the particle stack 70 is formed reaches the area where the ink droplet 20A can be ejected from the inkjet recording head 20 by the movement of the intermediate transfer body 12, the ink jet recording head 20 generates an image signal. Based on this, ink droplets are ejected onto the particle stack 70. The ink droplets 20A are ejected toward the second layer 51B of the particle laminate 70, and the ejection of the ink droplets 20A causes the particle laminate 70 to have an image layer as shown in FIG. 8C. 50C (a layer of the ink receiving particles 50 that have received the ink in the ink receiving particles 50 of the particle stack 70) is formed.

  Liquid components such as solvent and dispersion medium contained in the ink droplets 20A ejected from the ink jet recording head 20 to the particle stack 70 are quickly absorbed by the gaps between the ink receiving particles 50B and the gaps constituting the ink receiving particles 50B. At the same time, the recording material (for example, pigment) contained in the ink droplet 20A is also captured in the voids between the surfaces of the ink receiving particles 50B or the particles constituting the ink receiving particles 50B.

Here, the ink droplets 20A ejected toward the second layer 51B of the particle stack 70 are ink-receptive particles 50B constituting the second layer 51B located on the side where the ink droplets 20A are ejected. Accepted mainly by.
As described above, since the ink receiving particles 50B have a higher degree of neutralization than the ink receiving particles 50A, the ink absorbing performance is higher than that of the ink receiving particles 50A. For this reason, the ink receptive particle 50B absorbs ink by its high liquid absorption performance, and thus the softening temperature is lowered.

  Accordingly, the ink receptive particles 50A constituting the first layer 51A and the ink receptive particles constituting the second layer 51B in the particle stack 70 in a state before the ink droplets 20A are ejected by the ink jet recording head 20. Even if the softening temperature of 50B is the same, due to the difference in the degree of neutralization, in the state after the ink droplet 20A is ejected, the softening temperature is softened on the layer having the higher softening temperature (first layer 51A). A low temperature layer (second layer 51B) is laminated.

  Next, by receiving the ink droplet 20A, the image layer 50C is formed, and the layer having the low softening temperature (second layer 51B) is laminated on the layer having the high softening temperature (first layer 51A). The particle stack 70 in a state is conveyed by the circumferential movement of the intermediate transfer body 12 and transferred to the recording medium 8 from the intermediate transfer body 12 by the transfer apparatus 22 when reaching the position where the transfer apparatus 22 is provided. Thereafter, the image is fixed on the recording medium 8 by the fixing device 25. As a result, a color image is formed on the recording medium 8.

  At the time of transfer by the transfer device 22, as shown in FIG. 7, the first layer 51 A in contact with the intermediate transfer body 12 in the particle stack 70 is peeled off from the intermediate transfer body 12. 70 is peeled off from the intermediate transfer body 12 and transferred to the recording medium 8. Here, as described above, since the softening temperature of the second layer 51B is lower than that before receiving the ink droplet 20A by receiving the ink droplet 20A, the second layer 51B can be applied with low thermal energy. Softened to improve tackiness. Therefore, the particle stack 70 is transferred to the recording medium 8 efficiently and at high speed.

  When the particle stack 70 is transferred to the recording medium 8 by the transfer device 22, the first layer 51 A of the particle stack 70 is in contact with the recording medium 8 and the second layer 51 B is farthest from the recording medium 8. It is transferred to the recording medium 8 so as to form a layer (see FIG. 9). For this reason, after fixing by the fixing device 25, the image layer 50C is protected by the first layer 51A by the ink receiving particles 50A having the lower neutralization degree, that is, the higher softening temperature. . Accordingly, the abrasion resistance and heat resistance of the image layer 50C on which an image is formed can be obtained.

  Through the above steps, image formation on the recording medium 8 is completed.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, these examples do not limit the present invention.

[Example A1]
The recording temperature of the ink receiving particles 16A and the ink receiving particles 16B is set using a recording apparatus having the same configuration as that of the first embodiment (see FIGS. 1 to 3; however, the recording head is only black). An image was formed using the changed one and evaluated.

  The layer thickness of the release layer by the release agent on the intermediate transfer member (amount of the release agent applied) is 1 μm, and the layer thickness of the particle layer by the ink receiving particles 16A on the intermediate transfer member (of the ink receiving particles). Supply amount: at the time of supply) is 10 μm, the layer thickness of the particle layer by the ink receiving particles 16B (supply amount of the ink receiving particles: at the time of supply) is 15 μm, and the ink discharge amount is 1200 × 1200 dpi (dpi per inch) The image area density of the number of dots) was 4 pL per pixel, and the recording medium was OK Topcoat N paper (manufactured by Oji Paper Co., Ltd.). The ink used was prepared as follows.

-Adjustment of ink receiving particles 16A-
Styrene / n-butyl methacrylate / methacrylic acid copolymer particles (33 parts by mass / 10 parts by weight / 57 parts by weight, sphere equivalent average particle size 8 μm): 97 parts by mass Amorphous silica (particles constituting mother particles: Aerosil) OX50 / Degussa, sphere equivalent average particle size 0.04 μm): 1 part by mass Amorphous silica (particles constituting the base particles: Aerosil TT600 / Degussa, sphere equivalent average particle size 0.04 μm): 1 part by mass, polypropylene Wax (Pelestat 300 / Sanyo Chemical Co., Ltd.): 1 part by mass

A small amount of polyvinyl alcohol was added to the above components and mixed using a mill. This was designated as ink receiving particles 16A. The softening temperature of the adjusted ink receiving particles 16A was measured by the following method.
The softening temperature of the ink receiving particles was measured at 25 ° C. ± 2 ° C. based on JIS 7197 with a thermomechanical analyzer (TMA), and found to be 110 ° C.

-Adjustment of ink receiving particles 16B-
Styrene / n-butyl methacrylate / methacrylic acid copolymer particles (33 parts by mass / 40 parts by weight / 27 parts by weight, sphere equivalent average particle size of 8 μm): 97 parts by mass Amorphous silica (particles constituting mother particles: Aerosil) OX50 / Degussa, sphere equivalent average particle size 0.04 μm): 1 part by mass Amorphous silica (particles constituting the base particles: Aerosil TT600 / Degussa, sphere equivalent average particle size 0.04 μm): 1 part by mass, polypropylene Wax (Pelestat 300 / Sanyo Chemical Co., Ltd.): 1 part by mass

  A small amount of polyvinyl alcohol was added to the above components and mixed using a mill. This was designated as ink receiving particles 16B. When the softening temperature of the adjusted ink receiving particles 16B was measured in the same manner as described above, it was 20 ° C.

-Ink adjustment-
Carbon black (CB): 5 parts by mass Styrene / n-butyl methacrylate / methacrylic acid: 1.5 parts by mass Glycerin: 20 parts by mass Triethylene glycol: 5 parts by mass Diethylene glycol monobutyl ether: 2 parts by mass E1010 (manufactured by Nissin Chemical Co., Ltd.): 1 part by mass / water: remainder The above materials were mixed to obtain a liquid. The surface tension of this liquid was 31 mN / m.

(Evaluation)

Using a recording apparatus having the same configuration as that of the first embodiment (see FIGS. 1 to 3; however, the recording head has only one color), the softening temperatures of the ink receiving particles 16A and the ink receiving particles 16B are changed. An image was formed using the sample and evaluated. The recording conditions were set as follows.
Intermediate transfer member linear velocity: 200 mm / sec.
Charging conditions: The surface potential of the intermediate transfer member was set to −700V.
Development bias by particle supply device: A rectangular wave of AC Vpp 1.2 kV (3 kHz) is superimposed on DC -330V.
Particle supply conditions by a particle supply device that supplies the ink receiving particles 16A:
The peripheral speed ratio (supply roll 41A / intermediate transfer member 12) was 4, the gap was 0.4 mm, and the supply amount of the ink receiving particles 16A per unit area on the intermediate transfer member 12 was 3 g / m ² .
Ink acceptability per unit area on the intermediate transfer member 12 with a particle supply condition peripheral speed ratio (supply roll 41A / intermediate transfer member 12) 5 and a gap of 0.4 mm by a particle supply device that supplies ink receiving particles 16B. The supply amount of the particles 16B was 4 g / m ² .
Transfer temperature: The surface temperature of the transfer roll is set to 60 ° C.
Fixing temperature: Fixing roll surface temperature is set to 120 ° C.

―Evaluation of transferability―
A 100% coverage pattern was created using OK Kanfuji (Oji Paper Co., Ltd.) as the recording medium. Then, the remaining amount of the intermediate transfer member is visually observed and compared with respect to the recording medium on which the pattern is formed in both cases where the linear velocity of the intermediate transfer member 12 is 200 mm / second and 100 mm / second. did.

-Transferability evaluation index-
G1: Residual is not visually observed. There is no effect on the transferred image. G2: Residue is visually observed at the dot level, but there is no effect on the transferred image.
G3: Residue is visually observed and has a great influence on the transferred image.

  The evaluation results are shown in Table 1.

―Evaluation of heat resistance and blocking resistance―
A 100% coverage pattern was created using OK Kanfuji (Oji Paper Co., Ltd.) as the recording medium. The recording medium on which the pattern is formed for both the case where the linear velocity of the intermediate transfer body 12 is 200 mm / second and 100 mm / second is not printed in the constant temperature chamber at 80 ° C. Kanfuji (manufactured by Oji Paper Co., Ltd.) was pressed against an approximate recording medium with a load of 100 g, and 24 hours later, the image on the approximate paper piece and image changes were visually observed.

-Evaluation index for heat resistance and blocking resistance-
G1: Reflection on a piece of paper is not visually observed. No effect on image G2: Reflection on a piece of paper is visually observed at the dot level, but the image is not affected.
G3: Reflection on a piece of paper is seen with eyes and has a large effect on the image.

  The evaluation results are shown in Table 1.

―Evaluation of abrasion resistance―
A 100% coverage pattern was created using OK Kanfuji (Oji Paper Co., Ltd.) as the recording medium. Then, on the recording medium on which the above pattern was formed for both the case where the linear velocity of the intermediate transfer body 12 was 200 mm / second and 100 mm / second, OK Kanto, who was not printing as the rubbing resistance evaluation ( (Oji Paper Co., Ltd.) A paper piece was pressed against an almost recording medium with a load of 100 g and pulled in parallel, and the stain on the outline paper piece was visually observed.

−Rubbing resistance evaluation index−
G1: Dirt is hardly noticed visually.
G2: Some dirt is seen, but the image is not affected.
G3: There are stains and the image is affected.

  The evaluation results are shown in Table 1.

[Example A2]
Evaluation was performed in the same manner as in Example A1, except that the ink receiving particles 16A and ink receiving particles 16B prepared below were used instead of the ink receiving particles 16A and ink receiving particles 16B prepared in Example A1. went. The evaluation results are shown in Table 1.

-Adjustment of ink receiving particles 16A-
Styrene / 2-ethylhexyl acrylate / acrylic acid copolymer particles 30 parts by weight / 10 parts by weight / 60 parts by weight, sphere-converted average particle size 8 μm: 97 parts by weight Amorphous silica (base particle constituting particles: Aerosil OX50 / Degussa, sphere equivalent average particle size 0.04 μm): 1 part by mass Amorphous silica (base particle constituting particles: Aerosil TT600 / Degussa, sphere equivalent average particle size 0.04 μm): 1 part by mass Polypropylene wax (Pelestat 300 / manufactured by Sanyo Chemical Co., Ltd.): 1 part by mass

A small amount of polyvinyl alcohol was added to the above components and mixed using a mill. This was designated as ink receiving particles 16A. The softening temperature of the adjusted ink receiving particles 16A was measured by the following method.
When the softening temperature of the ink receiving particles was measured in the same manner as in Example A1, it was 105 ° C.

-Adjustment of ink receiving particles 16B-
Styrene / 2-ethylhexyl acrylate / acrylic acid copolymer particles 30 parts by mass / 30 parts by weight / 40 parts by weight, sphere equivalent average particle size 8 μm): 97 parts by mass Amorphous silica (particles constituting mother particles: Aerosil OX50 / Degussa, sphere equivalent average particle size 0.04 μm): 1 part by mass Amorphous silica (base particle constituting particles: Aerosil TT600 / Degussa, sphere equivalent average particle size 0.04 μm): 1 part by mass Polypropylene wax (Pelestat 300 / manufactured by Sanyo Chemical Co., Ltd.): 1 part by mass

A small amount of polyvinyl alcohol was added to the above components and mixed using a mill. This was designated as ink receiving particles 16A. The softening temperature of the adjusted ink receiving particles 16A was measured by the following method.
When the softening temperature of the ink receiving particles 16B was measured in the same manner as in Example A1, it was 25 ° C.

(Comparative Example A1)
The particle supply device for supplying the ink receiving particles 16A used in Example A1 was removed, and only the ink receiving particles 16A prepared in Example A1 were used, and the ink receiving particles 16A were used in Example A1. Evaluation was performed in the same manner as in Example A1, except that the ink receiving particles 16B used were set in a particle supply device and supplied under the particle supply conditions of the particle supply device. The evaluation results are shown in Table 1.

(Comparative Example A2)
Evaluation was performed in the same manner as in Example A1, except that the particle supply device for supplying the ink receiving particles 16A used in Example A1 was removed and only the ink receiving particles 16B prepared in Example A1 were used. It was. The evaluation results are shown in Table 1.

  From the above results, it can be seen that this example is superior in all of high-efficiency transferability, heat resistance after fixing, blocking resistance, and abrasion resistance as compared with the comparative example.

[Example B1]
The degree of neutralization of the ink receptive particles 50A and the ink receptive particles 50B using a recording apparatus having the same configuration as that of the second embodiment (see FIGS. 7 to 9; however, the recording head has only one color). An image was formed using an image obtained by changing the value and evaluated.

  The layer thickness of the release layer by the release agent on the intermediate transfer member (amount of the release agent applied) is 1 μm, and the layer thickness of the particle layer by the ink receiving particles 50A on the intermediate transfer member (of the ink receiving particles). (Supply amount: at supply) is 15 μm, the layer thickness of the ink receptive particles 50B (ink-receptive particle supply amount: at supply) is 15 μm, and the ink discharge amount is 1200 × 1200 dpi (dpi per inch). The image area density of the number of dots) was 4 pL per pixel, and the recording medium was OK Topcoat N paper (manufactured by Oji Paper Co., Ltd.). The same ink as in Example A1 was used.

-Adjustment of ink receiving particles 50A-
The following method can be used to control the degree of neutralization. The number of carboxylic acids present in the unneutralized polymer was adjusted by adding a neutralizing agent such as sodium hydroxide to the desired degree of neutralization. Specifically, it is as follows.

-After dissolving 100 g of styrene / 2-ethylhexyl acrylate / acrylic acid copolymer particles in an organic solvent, 80 g of a 5 mass% aqueous sodium hydroxide solution was added. The mixed solution was stirred at room temperature for 1 hour and then dried with a freeze dryer to form particles. Furthermore, after pulverizing with a jet mill, particles obtained by applying to a classifier (average particle diameter in terms of spheres: 8 μm): 97 parts by mass / amorphous silica (particles constituting mother particles: Aerosil OX50 / Degussa, converted to spheres) (Average particle size 0.04 μm): 1 part by mass / amorphous silica (base particle constituent particles: Aerosil TT600 / Degussa, sphere equivalent average particle size 0.04 μm): 1 part by mass / polypropylene wax (Pelestat 300 / Sanyo Kasei) 1 part by mass / styrene / 2-ethylhexyl acrylate / methacrylic acid copolymer (acid value 210)

  A small amount of polyvinyl alcohol was added to the above components and mixed using a mill. This was designated as ink receiving particles 50A of Example B1. The neutralization degree of the ink receiving particles 50A was measured and found to be 20%. Further, the softening temperature after receiving 100 parts by weight of the ink with respect to 100 parts by weight of the ink receiving particles 50A was measured in the same manner as in Example A1, and found to be 80 ° C.

-Adjustment of ink receiving particles 50B-
Ink receptivity prepared in Example B1 except that 180 g of 5% by weight sodium hydroxide aqueous solution was added instead of 80 g of 5% by weight sodium hydroxide aqueous solution in the adjustment of the ink receiving particles 50A in Example B1. Ink-receptive particles 50B were prepared in the same manner as the conductive particles 50A.

  The neutralization degree of the ink receiving particles 50B prepared in Example B1 was measured and found to be 60%. Further, the softening temperature after receiving 100 parts by weight of the ink with respect to 100 parts by weight of the ink receiving particles 50B was measured in the same manner as in Example A1, and found to be 15 ° C.

(Evaluation)
An image was formed and evaluated using a recording apparatus having the same configuration as that of the second embodiment (see FIGS. 7 to 8; however, the recording head has only one color of black). The recording conditions were set to the same conditions as in Example A1.

  In the same manner as in Example A1, transferability, heat resistance, abrasion resistance, and blocking resistance were evaluated. The evaluation results are shown in Table 2.

[Example B2]
Evaluation was made in the same manner as in Example B1, except that the ink receiving particles 50A and ink receiving particles 50B prepared below were used instead of the ink receiving particles 50A and ink receiving particles 50B prepared in Example B1. Went. The evaluation results are shown in Table 2.

-Adjustment of ink receiving particles 50A-
-Styrene / n-butyl methacrylate / acrylic acid copolymer particles 100 g of the above material was dissolved in an organic solvent, and then 100 g of a 5 mass% aqueous sodium hydroxide solution was added. The mixed solution was stirred at room temperature for 1 hour and then dried with a freeze dryer to form particles. Furthermore, the particle | grains obtained by grind | pulverizing with a jet mill and applying to a classifier (sphere conversion average particle diameter of 8 micrometers). : 97 parts by mass / amorphous silica (base particle constituting particles: Aerosil OX50 / Degussa, average particle diameter in terms of sphere: 0.04 μm): 1 part by weight / amorphous silica (base particle constituting particles: Aerosil TT600 / Degussa) , Sphere equivalent average particle size 0.04 μm): 1 part by mass / polypropylene wax (Pelestat 300 / manufactured by Sanyo Chemical Industries): 1 part by mass / styrene / 2-ethylhexyl acrylate / methacrylic acid copolymer (acid value 210)

  A small amount of polyvinyl alcohol was added to the above components and mixed using a mill. This was designated as ink receiving particles 50A. The neutralization degree of the ink receiving particles 50A was measured and found to be 10%. Further, the softening temperature after receiving 100 parts by weight of the ink with respect to 100 parts by weight of the ink receiving particles 50A was measured in the same manner as in Example A1, and found to be 90 ° C.

-Adjustment of ink receiving particles 50B-
Styrene / n-butyl methacrylate / acrylic acid copolymer particles After dissolving 100 g of the above material in an organic solvent, 200 g of a 5% by mass aqueous sodium hydroxide solution was added. The mixed solution was stirred at room temperature for 1 hour and then dried with a freeze dryer to form particles. Further, particles obtained by pulverizing with a jet mill and then applying to a classifier (average particle diameter in terms of spheres: 8 μm). : 97 parts by mass / amorphous silica (base particle constituting particles: Aerosil OX50 / Degussa, average particle diameter in terms of sphere: 0.04 μm): 1 part by weight / amorphous silica (base particle constituting particles: Aerosil TT600 / Degussa) , Sphere equivalent average particle size 0.04 μm): 1 part by mass / polypropylene wax (Pelestat 300 / manufactured by Sanyo Chemical Industries): 1 part by mass / styrene / 2-ethylhexyl acrylate / methacrylic acid copolymer (acid value 210)

  A small amount of polyvinyl alcohol was added to the above components and mixed using a mill. This was designated as ink receiving particles 50B of Example B2. The degree of neutralization of the ink receiving particles 50B was measured and found to be 65%. The softening temperature after receiving 100 parts by weight of the ink with respect to 100 parts by weight of the ink receiving particles 50B was measured in the same manner as in Example A1, and found to be 10 ° C.

(Comparative Example B1)
The particle supply device for supplying the ink receiving particles 50A used in Example B1 was removed, and only the ink receiving particles 50A prepared in Example B1 were used, and the ink receiving particles 50A were used in Example B1. Evaluation was carried out in the same manner as in Example B1, except that the ink receiving particles 50B used were set in a particle supply device and supplied under the particle supply conditions of the particle supply device. The evaluation results are shown in Table 2.

(Comparative Example B2)
Evaluation was performed in the same manner as in Example B1, except that the particle supply device for supplying the ink receiving particles 50A used in Example B1 was removed and only the ink receiving particles 50B prepared in Example B1 were used. It was. The evaluation results are shown in Table 2.

  From the above results, it can be seen that this example is superior in all of high-efficiency transferability, heat resistance after fixing, blocking resistance, and abrasion resistance as compared with the comparative example.

1 is a configuration diagram illustrating a recording apparatus according to a first embodiment. FIG. 1 is a configuration diagram illustrating a main part of a recording apparatus according to a first embodiment. (A) is a schematic diagram which shows the 1st layer by the ink receptive particle which concerns on 1st Embodiment, (B) is a schematic diagram which shows the 2nd layer laminated | stacked on the 1st layer. (C) is a schematic view showing a state in which ink droplets are ejected onto the particle laminate. FIG. 5 is a schematic diagram illustrating an example of a form different from that of FIG. 3B of the particle stack formed on the intermediate transfer member in the recording apparatus according to the first embodiment. FIG. 3 is a schematic diagram showing a particle stack transferred and fixed on a recording medium in the recording apparatus according to the first embodiment. It is a block diagram which shows the recording device which concerns on 2nd Embodiment. It is a block diagram which shows the principal part of the recording device which concerns on 2nd Embodiment. (A) is a schematic diagram which shows the 1st layer by the ink receptive particle which concerns on 2nd Embodiment, (B) is a schematic diagram which shows the 2nd layer laminated | stacked on the 1st layer. (C) is a schematic view showing a state in which ink droplets are ejected onto the particle laminate. FIG. 6 is a schematic diagram showing a particle laminate transferred and fixed on a recording medium in a recording apparatus according to a second embodiment. It is a conceptual diagram which shows an example of the ink receptive particle which concerns on this embodiment. It is a conceptual diagram which shows another example of the ink receptive particle which concerns on embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Recording apparatus 11 Recording apparatus 12 Intermediate transfer body 16 Ink receiving particle 16A The above ink receiving particle 16B The above ink receiving particle 17A The first layer 17B The second layer 18 The particle supply apparatus 18A The particle supply apparatus 18B The particle supply apparatus 20 Inkjet recording head 20C Inkjet recording head 20M Inkjet recording head 20Y Inkjet recording head 20K Inkjet recording head 22 Transfer device 25 Fixing device 40, 70 Particle stack 50 Ink receiving particles 50A Ink receiving particles 50B Ink receiving particles 51A First Layer 51B Second layer 60 Ink receiving particles 60A Ink receiving particles 60B Ink receiving particles 60 Particle supply device 60A Particle supply device 60B Particle supply device 200 Ink receiving particles 210 Ink receiving particles

Claims (8)

An intermediate transfer member;
A plurality of types of ink receptive particles that receive ink and have different softening temperatures are supplied in a layered manner on the intermediate transfer member for each type of ink receptive particle, and at least the first closest to the intermediate transfer member. Supply means for supplying the plurality of types of ink receiving particles so that the softening temperature of the ink receiving particles of one layer is higher than the softening temperature of the ink receiving particles of the second layer farthest from the intermediate transfer member When,
An ink droplet ejecting means for ejecting ink droplets toward a particle laminate of a plurality of types of the ink receiving particles supplied onto the intermediate transfer member by the supplying means;
Transfer means for transferring the particle laminate to a recording medium;
Fixing means for fixing the particle laminate transferred to the recording medium to the recording medium;
A recording apparatus comprising: The supply means includes
Supplying the ink receiving particles on the intermediate transfer member such that a layer of ink receiving particles having a low softening temperature is laminated from the first layer side toward the second layer side. The recording apparatus according to claim 1, wherein the recording apparatus is a recording apparatus. The supply means includes a plurality of particle supply means that are arranged along the moving direction of the intermediate transfer body and supply ink receiving particles having different softening temperatures to the intermediate transfer body in a layered manner.
Among the plurality of particle supply means, at least the most upstream particle supply means in the moving direction of the intermediate transfer member has a higher softening temperature than the ink receiving particles supplied by the most downstream particle supply means. Supplying the particles to the intermediate transfer member in layers to form the first layer;
Among the plurality of particle supply means, at least the most downstream particle supply means in the moving direction of the intermediate transfer body softens the ink receiving particles supplied by the supply means upstream of the intermediate transfer body. The recording apparatus according to claim 1, wherein the second layer is formed by supplying ink receiving particles having a temperature lower than that in layers.   4. The supply amount per unit area of ink receiving particles in the first layer is smaller than the supply amount per unit area of ink receiving particles in the second layer. The recording apparatus according to any one of the above. An intermediate transfer member;
A plurality of types of ink receptive particles that receive ink and have different degrees of neutralization are supplied in a layered manner on the intermediate transfer member for each type of ink receptive particle, and are at least closest to the intermediate transfer member The plurality of types of ink receiving particles are supplied so that the degree of neutralization of the ink receiving particles of the first layer is lower than the degree of neutralization of the ink receiving particles of the second layer farthest from the intermediate transfer member. Supply means for
An ink droplet ejecting means for ejecting ink droplets toward a particle laminate of a plurality of types of the ink receiving particles supplied onto the intermediate transfer member by the supplying means;
Transfer means for transferring the particle laminate to a recording medium;
Fixing means for fixing the particle laminate transferred to the recording medium to the recording medium;
A recording apparatus comprising: The supply means includes
Supplying the ink receiving particles on the intermediate transfer member such that a layer of ink receiving particles having a high degree of neutralization is laminated from the first layer side toward the second layer side; The recording apparatus according to claim 5. The supply means includes a plurality of particle supply means that are arranged along the moving direction of the intermediate transfer body and supply ink-receptive particles having different degrees of neutralization to the intermediate transfer body in layers.
Among the plurality of particle supply means, at least the most upstream particle supply means in the moving direction of the intermediate transfer member has a lower neutralization degree than the ink receiving particles supplied by the most downstream particle supply means. Supplying the conductive particles in layers to the intermediate transfer member to form the first layer,
Among the plurality of particle supply means, at least the most downstream particle supply means in the moving direction of the intermediate transfer body is the ink receiving particle supplied by the supply means upstream of the intermediate transfer body. The recording apparatus according to claim 5, wherein the second layer is formed by supplying ink receptive particles having a higher degree of harm in layers.   The supply amount per unit area of the ink receiving particles in the first layer is smaller than the supply amount per unit area of the ink receiving particles in the second layer. The recording apparatus according to any one of the above.