JP2009233968A - Recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording device effectively suppressing blocking. <P>SOLUTION: The recording device 10 comprises: an intermediate transfer body 12; a first particle supply means 18 for supplying ink-accepting particles 16 in a layered shape; an ink application means 20 for applying ink to a layer 16A of the ink-accepting particles; a transfer means 22 for transferring the ink-accepting particle layer to a recording medium 8; a second particle supply means 15 for supplying, to the ink-accepting particle layer transferred to the recording medium, second particles 17 lower in absorbability to a liquid component of the ink or adhesiveness, which develops when the liquid component of the ink is absorbed, than the ink-accepting particles; and a pressing means 25 for pressing the recording medium with the second particles supplied thereto. <P>COPYRIGHT: (C)2010,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. In addition, various methods such as a so-called thermal ink jet method that ejects ink using pressure generated by growth have been proposed. By these methods, extremely high-definition images and recorded data can be obtained. it can.

In recording methods using ink, including inkjet recording methods, a method of recording on an intermediate and then transferring it to a recording medium in order to record on various recording media such as a permeable medium and a non-penetrable medium. Has been proposed.
For example, the inkjet recording method using water-based ink is a recording method with excellent environmental characteristics in terms of safety and energy characteristics, but because it handles water, it provides high speed and high image quality such as feathering and paper curl / cuckling. It is difficult to achieve both. Since these are caused by water, which is the solvent of the ink, an ink jet recording apparatus using liquid-absorbing particles in an intermediate transfer recording method has been proposed.

  For example, Patent Document 1 discloses an ink jet recording apparatus including a first application unit and a second application unit that apply water-absorbing powder to an intermediate transfer medium.

  In Patent Document 2, after forming a plurality of particle layers with different particles on an intermediate transfer member, ink is supplied and transferred to a medium such as paper to form an image, which is absorbed as the first layer. An apparatus for forming an image with excellent robustness by supplying non-liquid particles is disclosed.

In Patent Document 3, a microcapsule having a shell part made of a substance having a function of protecting an image and a core part made of a substance having releasability was added to a recorded image formed on a recording medium by an ink jet recording method. Thereafter, an ink jet recording apparatus is disclosed in which the recording image is protected by heating and exhibits releasability.
JP 2006-137120 A JP 2007-168406 A JP 2003-039645 A

In a recording apparatus that uses liquid-absorbing particles in the intermediate transfer recording method, the ink image is transferred to a medium such as paper by applying pressure by utilizing the adhesiveness that the particles develop by absorbing the solvent in the ink. Is done by. However, depending on the fixing conditions, even after the fixing, the image surface is tacky, and a phenomenon of sticking to each other (blocking) easily occurs when the output media are stacked.
Since the particles absorb the ink solvent and develop tackiness, for example, it is conceivable to suppress the tackiness by evaporating the liquid component during fixing, but in this case, a large amount of energy is required, which is practical. Absent.

  An object of the present invention is to provide a recording apparatus in which blocking is effectively suppressed.

The above problem is solved by the following means.
The invention according to claim 1
An intermediate transfer member;
First particle supply means for supplying ink receiving particles for receiving ink in a layer form on the intermediate transfer member;
An ink applying means for applying ink to the layer of the ink receiving particles supplied on the intermediate transfer member;
Transfer means for transferring the layer of the ink receiving particles to which the ink has been applied to a recording medium;
The ink receptive particle layer transferred to the recording medium has less absorbability with respect to the liquid component of the ink or less adhesiveness when the ink liquid component is absorbed than the ink receptive particle. A second particle supply means for supplying two particles;
Pressing means for pressing the recording medium supplied with the second particles;
It is a recording device characterized by having.

The invention according to claim 2
The recording apparatus according to claim 1, wherein the pressing unit is a unit that presses and heats the recording medium supplied with the second particles.

The invention according to claim 3
It further has a particle removing means for removing a part of the second particles supplied from the second particle supplying means to the recording medium between the second particle supplying means and the pressing means. The recording apparatus according to claim 1 or 2.

The invention according to claim 4
The recording apparatus according to claim 3, wherein the particle removing unit is a unit that electrostatically removes the second particles.

  According to the first aspect of the invention, the second particles function as spacers, and the effect of suppressing the occurrence of blocking of the recording medium after image formation is achieved.

  According to the second aspect of the invention, it is possible to further adjust the texture and image fastness of the surface of the medium after recording.

  According to the third aspect of the invention, there is an effect that mainly the second particles in the non-image area are removed and the occurrence of blocking is efficiently suppressed.

  According to the invention which concerns on Claim 4, there exists an effect that a part of 2nd particle | grain is removed more efficiently.

  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 same effect | action and function through all the drawings, and the overlapping description may be abbreviate | omitted.

-First embodiment-
FIG. 1 is a schematic configuration diagram illustrating a recording apparatus according to the first embodiment.
The recording apparatus 10 according to the first embodiment includes, for example, an endless belt-shaped intermediate transfer body 12, a charging device 28 that charges the surface of the intermediate transfer body 12, and ink receiving particles 16 in a charged region on the intermediate transfer body 12. To form a particle layer 16A, an ink jet recording head 20 that forms an image by ejecting ink droplets onto the particle layer 16A, and a recording medium 8 superimposed on the intermediate transfer body 12 to apply pressure. In addition, the transfer device 22 for transferring the ink receptive particle layer 16A onto the recording medium 8, and the ink receptive particle layer 16A absorbs the ink liquid component or absorbs the ink liquid component more than the ink receptive particle 16. The second particle supply device 15 for supplying the second particles (for example, resin particles) 17 with low adhesiveness, and the recording medium 8 supplied with the second particles 17. And a fixing device 25, etc. for fixing the ink receptive particle layer 16A and the resin particles 17 by applying heat while pressing.
Hereinafter, the main part of the recording apparatus 10 will be described in detail.

<Intermediate transfer member>
In order to supply and hold the ink receiving particles 16 on the surface of the intermediate transfer member 12 by electrostatic force, the surface of the intermediate transfer member needs to have a semiconductive or insulating particle holding property. As the electrical characteristics of the surface of the intermediate transfer member, in the case of semi-conductivity, the surface resistivity is 10 ¹⁰ Ω / □ or more and 10 ¹⁴ Ω / □ or less, the volume resistivity is 10 ⁹ Ω · cm or more and 10 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 case of the belt-shaped intermediate transfer body 12, the substrate can be driven to rotate the belt in the apparatus, has the necessary mechanical strength, and has the necessary heat resistance especially when heat is used during transfer / fixing. It only has to have it. Specifically, polyimide, polyamideimide, aramid resin, polyethylene terephthalate, polyester, polyethersulfone, stainless steel and the like are used.

For example, the intermediate transfer member 12 is formed by forming a surface layer of ethylene propylene rubber (EPDM) having a thickness of 400 μm on a base layer of a polyimide film having a thickness of 1 mm. 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).
The intermediate transfer member may be cylindrical (drum-shaped). In the case of a drum-shaped intermediate transfer body, the base material may be aluminum, stainless steel, or the like.

<Charging device>
The charging device 28 forms, for example, an elastic layer (such as 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 to 10 ⁸ Ω. -It is set as the roll-shaped member adjusted to about cm or less. Further, the surface of the elastic layer is covered with a water / oil repellent coating layer having a thickness of 5 μm or more and 100 μm or less (for example, a layer made of tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA)).

A DC 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, for example, a voltage of 1 kv is applied to the surface of the intermediate transfer member 12 by the charging device 28 to charge the surface of the intermediate transfer member 12.
The charging device 28 may be composed of a corotron or the like.

<First particle supply device>
The first particle supply device 18 supplies the ink receiving particles 16 to the surface of the intermediate transfer body 12 to form the ink receiving particle layer 16A. As a method of forming the ink receptive particle layer 16A, a one-component development method or a two-component development method, which is a method of developing a photoreceptor with a general electrophotographic toner, is applied.
In the first particle supply device 18, a supply roll 18A is arranged at a portion facing the intermediate transfer body 12 in a container in which the ink receiving particles 16 are accommodated, and a charging blade 18B is arranged so as to press the supply roll 18A. The The charging blade 18B also has a function of regulating the layer thickness of the ink receiving particles 16 supplied to the surface of the supply roll 18A.

  The ink receiving particles 16 are supplied to the supply roll 18A (conductive roll), the ink receiving particle layer 16A is regulated by the charging blade 18B (conductive blade), and the negative polarity is opposite to the charge on the surface of the intermediate transfer body 12. Is charged. For example, the supply roll 18A is a solid aluminum roll, and the charging blade 18B is a metal plate (SUS or the like) to which urethane rubber is attached in order to apply pressure. The charging blade 18B is in contact with the supply roll 18A by a doctor blade method.

  For example, an ink receiving particle storage cartridge may be detachably connected to the first particle supply device 18 via a supply pipe, or a release agent may be supplied upstream of the charging device 28. You may provide the mold release agent supply apparatus which forms a mold release layer.

<Inkjet recording head>
The ink jet recording head 20 includes ink jet recording heads 20K, 20C, 20M, and 20Y for each color that are driven by a piezoelectric method, a thermal method, or the like. The ink jet recording head 20 applies ink droplets to the ink receiving particle layer 16 </ b> A on the intermediate transfer body 12 based on predetermined image information (image signal). Each color ink droplet is ejected to a predetermined position to form a color image.

  Further, the recording apparatus 10 is provided with a transparent liquid applying head 21 for applying a transparent liquid that does not contain a color material. The head 21 applies a transparent liquid that is the same component (for example, water) as the solvent component of the ink to be used to the non-image portion of the ink receiving particle layer 16A on the intermediate transfer body 12. As a result, the entire ink-receptive particle layer 16A, including non-image portions to which ink is not applied from the respective ink-jet recording heads 20K, 20C, 20M, and 20Y, exhibits adhesiveness, and the ink-receptive particle layer 16A is recorded on the recording medium by pressing. It is possible to transfer all of the image on the surface 8 (entire transfer).

<Transfer device>
The transfer device 22 includes a transfer roll 22A supported by a spring 22C and a pressure roll 22B facing each other with the intermediate transfer body 12 interposed therebetween. The transfer roll 22A and the pressure roll 22B move the intermediate transfer body 12 between them. A contact portion is formed by sandwiching. As the transfer roll 22A and the pressure roll 22B, for example, a product in which an outer surface of an aluminum core is coated with silicone rubber and further coated with a PFA tube can be used. The recording medium 8 and the intermediate transfer body 12 are sandwiched between transfer devices 22 and pressure is applied.

  The ink receptive particle layer 16A on the intermediate transfer body 12 absorbs the solvent in the ink when applied with, for example, and develops adhesiveness. Therefore, by utilizing this adhesiveness, the ink receiving particle layer 16A on which the ink is applied on the intermediate transfer body 12 and the recording medium 8 are superimposed and pressed, whereby the ink receiving particle layer 16A is placed on the recording medium 8. Transcribed.

  If necessary, a heat source may be provided in the transfer device 22 so that transfer is performed by pressurization and heating. While the organic resin constituting the ink receiving particles 16 is heated to, for example, less than the glass transition temperature (Tg) by the transfer device 22, the ink receiving particle layer 16A formed on the surface of the intermediate transfer body 12 by the pressure is released. And transferred onto the recording medium 8. The intermediate transfer body 12 may be preheated before the transfer device 22.

<Second particle supply device>
In the second particle supply device 15, a supply roll 15A is arranged in a container in which the second particles 17 are accommodated, and the second particles 17 are supplied to the ink receiving particle layer 16A via the supply roll 15A. Further, as shown in FIG. 2, the charging blade 15B may be arranged so as to be pressed toward the supply roll 15A in the same manner as the configuration of a general developing device. Such a charging blade 15B also has a function of regulating the layer thickness of the second particles 17 supplied to the surface of the supply roll 15A.

For example, the supply roll 15A can be a solid aluminum roll, and the charging blade 15B can be a metal plate (such as SUS) to which urethane rubber is attached in order to apply pressure. The charging blade 15B is in contact with the supply roll 15A by a doctor blade method.
The supply amount of the second particles is adjusted not only by the charging blade 15B but also by the rotation speed of the supply roll 15A, for example.

  The configuration of the second particle supply device is not particularly limited as long as it has a function of supplying the second particles 17 in a desired amount onto the ink receiving particle layer 16A. For example, as shown in FIG. In addition, an anilox roll 15C having fine holes regularly arranged on the surface, a combination of supplying second particles by contact and scraping with a blade, a printing spreader, etc. may be applied. it can.

<Fixing device>
The fixing device 25 includes a heating roll 25A containing a heating source 25C and a pressure roll 25B facing the heating roll 25A. The heating roll 25 </ b> A and the pressure roll 25 </ b> B form a contact portion through the opening of the support 23 that supports the recording medium 8.

  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.

  By sandwiching the recording medium 8 and the intermediate transfer body 12 by the fixing device 25 and applying pressure while heating the glass transition temperature (Tg) or higher of the organic resin constituting the ink receiving particles 16, for example, on the recording medium 8. The ink receiving particle layer 16A is fixed. At this time, depending on the material of the second particles and the heating temperature (fixing temperature), the second particles 17 on the surface of the ink receptive particle layer 16A are also softened (or melted), and the second particle 17 layer is formed. The ink receiving particle layer 16A is fixed on the recording medium 8 together with 17A.

  Next, the step of forming an image on the recording medium 8 in the recording apparatus 10 according to the present embodiment will be described in more detail.

(A) Supply of ink receiving particles (formation of ink receiving particle layer)
First, the charging device 28 charges the surface of the intermediate transfer body 12 with a polarity opposite to that of the ink receiving particles 16. As a result, the ink receiving particles 16 supplied by the supply roll 18 </ b> A of the particle supply device 18 are electrostatically adsorbed to form a layer of the ink receiving particles 16 on the surface of the intermediate transfer body 12. At this time, as a method of forming the ink receptive particle layer 16A, a method of supplying a general electrophotographic toner to the photoreceptor can be applied. That is, charges are previously supplied to the surface of the intermediate transfer body 12 by a general electrophotographic charging method (charging by the charging device 28, etc.). The ink receiving particles 16 are triboelectrically charged (one-component triboelectric charging method or two-component method) with a polarity opposite to the charge on the surface of the intermediate transfer member 12.

  In addition, before charging the surface of the intermediate transfer body 12, a release layer may be formed by a release layer supply device (not shown) as necessary. In particular, if the material of the intermediate transfer body 12 is aluminum or PET base, it is desirable to form a release layer. Alternatively, a fluororesin / silicone rubber-based material may be used so that the surface of the intermediate transfer body 12 has releasability.

  Examples of the release agent include release materials such as silicone oil, fluorine oil, polyalkylene glycol, and surfactant.

Examples of the silicone oil include straight silicone oil and modified silicone oil.
Examples of the straight silicone oil include dimethyl silicone oil and methyl hydrogen silicone oil.
Examples of the modified silicone oil include methylstyryl-modified oil, alkyl-modified oil, higher fatty acid ester-modified oil, fluorine-modified oil, and amino-modified oil.
Examples of the polyalkylene glycol include polyethylene glycol, polypropylene glycol, ethylene oxide-propylene oxide copolymer, and polybutylene glycol. Among these, polypropylene glycol is preferable.
Examples of the surfactant include an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant. Among these, a nonionic surfactant is desirable.

  The viscosity of the release agent is preferably, for example, from 5 mPa · s to 200 mPa · s, more preferably from 5 mPa · s to 100 mPa · s, and even more preferably from 5 mPa · s to 50 mPa · s.

The viscosity is measured as follows. The viscosity of the ink obtained was measured using Rheomatt 115 (manufactured by Contraves) as a measuring device. The measurement was performed by placing the sample in a measurement container and mounting it on the apparatus by a predetermined method, under the conditions of a measurement temperature of 40 ° C. and a shear rate of 1400 s ⁻¹ .

  The surface tension of the release agent is, for example, in the range of 40 mN / m or less (desirably 30 mN / m or less, more desirably 25 mN / m or less).

  The surface tension is measured as follows. In an environment of 23 ± 0.5 ° C. and 55 ± 5% RH, the surface tension of the obtained sample was measured using a Wilhelmy type surface tension meter (manufactured by Kyowa Interface Science Co., Ltd.).

  The boiling point of the release agent is, for example, in the range of 250 ° C. or higher (desirably 300 ° C. or higher, more preferably 350 ° C. or higher) under 760 mmHg.

  The boiling point is measured as follows. Measurement was performed according to JIS K2254, and the initial boiling point was used as the boiling point.

  After charging, the ink receiving particles 16 are formed as a layer on the surface of the intermediate transfer body 12 provided with a release agent as described above by the supply roll 18A of the first particle supply device 18 as necessary.

  The ink receiving particle layer 16A may be one or more layers, and may be formed to have a thickness in which, for example, the ink receiving particles 16 are overlapped by about three layers. By controlling the ink receiving particle layer 16A to a desired thickness by the gap between the charging blade 18B and the supply roll 18A, the thickness of the ink receiving particle layer 16A transferred to the recording medium 8 is also controlled. Alternatively, the thickness of the ink receiving particle layer 16A may be controlled by the peripheral speed ratio between the supply roll 18A and the intermediate transfer body 12.

  The charged ink receptive particles 16 form, for example, a single particle layer (a single particle layer, the same applies hereinafter) on the surface of the supply roll 18A, and are conveyed to a portion facing the surface of the intermediate transfer body 12. , The charged ink receiving particles 16 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 18A and the surface of the intermediate transfer member 12.

  At this time, for example, the moving speed of the intermediate transfer body 12 and the rotation speed of the supply roll 18A are relatively set so that a single particle layer is formed on the surface of the intermediate transfer body 12 (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 16, and the positional relationship between the supply roll 18A and the intermediate transfer member 12.

The number of particles supplied onto the intermediate transfer body 12 is increased by relatively increasing the peripheral speed of the supply roll 18A on the basis of the peripheral speed ratio for forming the one ink receptive particle layer 16A. Can be made. 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 is set to the minimum necessary thickness (for example, 1 μm to 5 μm). In addition, when the image density is high (when the ink shot amount is large (for example, 4 g / m ² or more and 15 g / m ² or less)), a sufficient layer capable of holding the ink liquid component (solvent or dispersion medium). It is desirable to control the thickness (for example, 10 μm or more and 25 μm or less).

  In addition, when forming an image with a higher ink ejection amount than the primary color, such as a secondary color or tertiary color image, the ink receptive particle layer is held by the ink liquid component (solvent or dispersion medium). The ink receiving particles 16 are laminated so that the recording material (for example, pigment) is captured and a sufficient number of particles do not reach the lowermost layer. In this case, the image forming material (pigment) may not be exposed on the surface of the image layer after transfer / fixing, and the ink receiving particles 16 that do not perform image formation may be formed on the image surface as a protective layer.

  As shown in FIG. 1, for example, a flattening device (packing roller) 30 in which a roller 30 </ b> A is supported by a spring 30 </ b> B so as to move up and down is provided between the first particle supply device 18 and the inkjet recording head 20. If provided, the surface of the ink receptive particle layer 16A is made to a level that does not hinder the image formation due to the ejection of ink droplets.

  Here, the thickness of the ink receiving particle layer 16A is desirably 1 μm or more and 100 μm or less, more desirably 1 μm or more and 50 μm or less, and further desirably 5 μm or more and 25 μm or less. Further, the porosity in the ink receptive particle layer (that is, the void ratio between the ink receptive particles + the void ratio in the ink receptive particles (trap structure)) is preferably 10% or more and 80% or less. Is from 30% to 70%, more preferably from 40% to 60%.

  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 one ink receptive particle layer on the intermediate transfer member, the image forming material (pigment) in the ink is on the intermediate transfer member. The ink receptive particle layer is captured on the surface of the ink receptive particle layer, and is fixed to the ink receptive particle surface and the internal particle void so that the distribution in the depth direction is reduced.

(B) Application of ink Next, an ink is applied to the ink receiving particle layer 16A formed on the intermediate transfer body 12 based on image information to form an image. Here, before the image is formed by ejecting the ink droplets of the respective colors from the ink jet recording heads 20K, 20C, 20M, and 20Y for the respective colors, the transparent liquid A transparent liquid (for example, water) that is the same component as the solvent component of the ink is ejected from the application head 21. The transparent liquid supplied onto the ink receiving particle layer 16A is quickly absorbed into the voids of the ink receiving particle layer 16A.

  On the other hand, ink droplets of the respective colors are ejected from the ink-jet recording heads 20K, 20C, 20M, and 20Y for the respective colors to a portion (image portion) where an image is formed in the ink receiving particle layer 16A on the intermediate transfer body 12. The The ink droplets ejected from the ink jet recording head 20 are driven into the ink receiving particle layer 16A, and the liquid component of the ink is quickly absorbed into the gaps between the ink receiving particles 16 and the gaps of the ink receiving particles 16. The recording material (for example, pigment) is also captured on the surface of the ink receiving particles 16 (constituting particles) or in the gaps between the particles forming the ink receiving particles 16.

  In order to reliably trap the recording material (for example, pigment) on the surface of the ink receiving particle layer 16 </ b> A and the interparticle voids in the ink receiving particle 16, the ink and the ink receiving particle 16 are reacted to thereby record the recording material ( For example, a method of quickly insolubilizing (aggregating) the pigment) may be employed. Specifically, it is possible to apply a reaction between the ink and the polyvalent metal salt or a pH reaction type as the reaction.

  In addition, a line type ink jet recording head having a width equal to or larger than the width of the recording medium is desirable. However, using a conventional scan type ink jet recording head, images are sequentially formed on the particle layer formed on the intermediate transfer member. It may be formed. The ink discharge means of the ink jet recording head 20 and the transparent liquid discharge means of the transparent liquid applying head 21 are not limited as long as they can discharge ink or transparent liquid, such as a piezoelectric element driving type and a heating element driving type.

  As the ink itself, an ink using a conventional dye as a coloring material can be used, but a pigment ink is desirable.

  Hereinafter, the ink applied in the embodiment will be described. 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.

  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.

  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 average particle diameter of the recording material is, for example, 10 nm or more and 1000 nm or less.

  The volume average particle size 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 a volume average particle diameter measuring apparatus. 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.
Table 1 shows the ink composition used when measuring the liquid absorbency (adhesion expression) of particles of samples A to C described later.

  As described above, with respect to the ink receptive particle layer 16A on the intermediate transfer member 12, a transparent liquid is applied to the non-image portion and ink is applied to the image portion, so that the entire ink receptive particle layer 16A is formed. Adhesiveness will be developed.

(C) Transfer Next, the ink receiving particle layer 16A to which ink is applied is transferred from the intermediate transfer body 12 onto the recording medium 8, whereby a color image is formed on the recording medium 8. The ink receiving particle layer 16A on the intermediate transfer body 12 is pressurized by the transfer device 22 (transfer roll 22A and pressure roll 22B). At this time, the entire ink-receptive particle layer 16A including the non-image portion is tacky. Therefore, the entire ink-receptive particle layer 16A can be transferred to the recording medium 8 only by pressing with the transfer roll 22A and the pressure roll 22B. It is transferred onto the entire surface (entire transfer).
However, when the adhesiveness expressed in the ink receptive particle layer 16A is relatively small, or depending on the type of the recording medium, the transfer device 22 may be provided with a heating source and heated together with the pressure to perform the transfer.

  In addition, as the recording medium 8, a permeation medium (for example, plain paper, ink jet coated paper, etc.) and a non-penetration medium (for example, art paper, resin film, etc.) can be applied. The recording medium is not limited to these, and includes other industrial products such as semiconductor substrates.

(D) Supply of Second Particles Next, the second particles 17 are supplied by the second particle supply device 15 to the ink receiving particle layer 16 </ b> A transferred onto the recording medium 8. As the second particles 17, those having lower absorbability with respect to the liquid component of the ink or less adhesiveness when absorbing the liquid component of the ink than the ink receptive particles 16 are used.

-Absorptivity to liquid components of ink-
Here, the particles having a smaller absorbability with respect to the liquid component of the ink than the ink receptive particles 16 are particles having a lower absorbability of the ink per unit weight when the same ink is used. Particles that do not substantially absorb the liquid component of the ink. The absorbability with respect to the liquid component of the ink is measured by the following method.

  The absorbability of the ink with respect to the liquid component is determined by applying ink (printing, droplet ejection) to the dispersed particles with an ink jet head and setting the ink absorption characteristics for the particles when bleeding occurs. The sprayed particles are managed by the weight before and after spraying, and the weight of the applied ink is controlled by the weight and number of dots (number of dots) measured by another means ejected from the head. The amount of ink applied per unit area with respect to the particle layer is changed by setting a plurality of weights for each droplet discharged from the head to be variable.

  For example, the particle layer is formed using the adhesiveness of silicone rubber. As shown in FIG. 10, by absorbing liquid absorbing particles 44 on a silicone film 42 (thickness: 0.1 mm) laminated on a polyethylene terephthalate (PET) film 40 (thickness: 0.1 mm), and scraping with a blade. Approximately one layer can be formed.

The print pattern is a solid pattern (pattern A) of 50 × 50 dots as shown in FIG. 11A, for example, and drawing is performed at 1200 dpi × 1200 dpi. In this case, it is necessary to complete drawing in one scan using a recording head in which nozzles are equivalently arranged at 1200 npi.
Judgment of the point where bleeding occurs is a pattern B (44 × 44 dots inside a solid pattern of 50 × 50 dots) as shown in FIG. In consideration of the influence of adjacent dots, the line is 3 dots.) Patterns A and B are captured by an image capturing device, binarized, and measured for external size (for example, using a microscope manufactured by Keyence Corporation, trade name: VHX-600). If the sizes are different between the patterns A and B, it is determined that the condition has exceeded the amount of ink that the particles can hold.

It is assumed that the above evaluation is performed from a small value that can set the ink drop weight, and the ink drop weight immediately before the result of the different size is the ink weight that the particle layer can hold. In addition, it is preferable to carry out a plurality of times in consideration of variations in measurement conditions.
Once the weight of ink that can be retained by the particle layer is determined, the following is required for the particle layer and ink weight.
Particle layer: The particle weight per unit area is determined from the spray area and spray weight.
Ink weight: The ink weight per unit area is determined from the droplet ejection area and the droplet ejection weight (weight of one droplet × number of dots).
By determining the ink weight per unit area / the particle weight per unit area, it is possible to determine the ratio of ink weight / particle weight that can be retained.
The particles that do not substantially absorb the liquid component of the ink are specifically particles having an ink weight / particle weight ratio of 0.55 or less that can be held.

  Table 2 shows the results obtained by measuring a plurality of samples A to C by the above method. Samples A to C are as follows.

Sample A (no liquid absorption)
・ Styrene / 2-ethylhexyl methacrylate / acrylic acid copolymer (acid value 200)
The material was pulverized with a jet mill and then subjected to a classifier to obtain particles. Particles having a sphere equivalent particle diameter of 8 μm were obtained, and the degree of neutralization of the particles was 0.

Sample B (weak liquid absorption)
・ Styrene / 2-ethylhexyl methacrylate / acrylic acid copolymer (acid value 210)
After 100 g of the above material was dissolved in an organic solvent, 120 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, it was applied to a classifier. Particles having a sphere equivalent particle diameter of 8 μm were obtained, and the degree of neutralization of these particles was 0.4.

Sample C (high liquid absorption)
Styrene / 2-ethylhexyl methacrylate / acrylic acid copolymer (acid value 385)
After 100 g of the above material was dissolved in an organic solvent, 200 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, it was applied to a classifier. Particles having a sphere equivalent particle diameter of 8 μm were obtained, and the degree of neutralization of these particles was 0.4.

  In addition, the acid value of resin of the said samples A-C is the value obtained by neutralizing and titrating material with KOH and measuring the quantity of (COOH). Specifically, after the resin is dissolved in an IPA (isopropyl alcohol) / water mixed solvent, the acid value potentiometric method of JIS K2501 (2003) (a potentiometer and a pH meter are used for measurement), The acid value is determined by measuring the consumption of KOH.

The degree of neutralization is determined by neutralizing and titrating the material with KOH to measure the amount of (COOH), then titrating the neutralized material with HCl and measuring the amount of (COO-). The sum is calculated by the formula of “degree = (COO −) / (COOH)”.
Specifically, after the particles are dissolved in an IPA / water mixed solvent, the consumption of KOH is determined according to the acid value potentiometric method of JIS K2501 (2003) (a potentiometer and a pH meter are used for the measurement). Is measured to calculate the molar amount of (COOH). Next, the neutralized particles are dissolved in an IPA / water mixed solvent, HClaq is used as a titration solution, and an acid value potentiometric method of JIS K2501 (2003) (a potentiometer and a pH meter are used for measurement). According to, the consumption of HCl is measured to calculate the molar amount of (COO-). From these, the neutralization degree is calculated by the above formula.

  Samples A and B have low liquid absorbency, and in particular, sample A has an ink weight / particle weight ratio of 0.50, and can be said to be particles that do not substantially absorb the liquid component of the ink.

  If the non-liquid-absorbing or low-liquid-absorbing particles 17 that hardly absorb the liquid component of the ink are supplied onto the ink receiving particle layer 16A, the ink receiving is thereafter performed by a fixing process as shown in FIG. Even if the non-liquid-absorbing (low liquid-absorbing) particles 17 are exposed even if pushed into the conductive particle layer 16A, the adhesiveness is lower than before the particles 17 are supplied. Therefore, as shown in FIG. 5, even when the recording medium 8 after image formation is stacked, the non-liquid-absorbing (low liquid-absorbing) particles 17 function as spacers and the occurrence of blocking is suppressed.

-Adhesiveness that develops when the liquid component of ink is absorbed-
On the other hand, particles having less adhesiveness when absorbing the liquid component of the ink than the ink receptive particles 16 are within the range of the holdable ink weight / particle weight ratio (0 to the maximum holdable value). The peak value of the adhesive strength (adhesive strength) is a particle smaller than that of the ink receptive particles 16, and preferably a particle that does not substantially exhibit tackiness even when the liquid component of the ink used is absorbed.

  The adhesiveness expressed with respect to the liquid component of the ink is measured by a measurement according to JIS Z 0237 “Adhesive tape / adhesive sheet test method” for measuring the peel strength of 90 °. At this time, as shown in FIG. 12, for example, a silicone film 42 (thickness: 0.1 mm) laminated on a PET film 40 (thickness: 0.1 mm) and a polyimide (PI) film 46 ( Measurement is performed by substituting the sample prepared at a thickness of 0.025 mm.

Basically, it is a measurement method according to JIS Z 0237, but it is a test method premised on an adhesive tape and a sheet, and a method for producing an adhesive tape-like material will be described below.
The formation of the particle layer 44 (FIG. 12A) and the ink droplet ejection (FIG. 12B) are performed by the same method as in measuring the absorbability of the ink with respect to the liquid component. At this time, the ink drop weight is variable.
The particle layer 44 on which ink droplets have been deposited is covered with a PI film 46 and pressed to be transferred (FIG. 12C). At this time, the PI film 46 has a width of 25 mm. The pressure transfer is sandwiched between opposing rolls, at least one of which is an elastic body, adjusted so that a pressure of 1.0 MPa is applied, and moved at a constant speed (for example, 10 mm / s).
After pressurizing in this way, the PI film 46 is peeled off from the silicone film 42 to obtain an adhesive tape-like test piece 48 of the PI film base 46 (FIG. 12D).

Thereafter, the measurement conforms to JIS Z 0237, but regarding the ink droplet ejection weight, for example, if droplet ejection is performed at an interval of 1200 dpi, a dot diameter (about 24 μm) corresponding to an area of a 1200 dpi grid is set. The ink droplet / particle weight ratio is at least 0. 0 in the range from the droplet ejection weight (approximately 0.7 ng to 1.3 ng depending on the spread due to droplet ejection) to the maximum droplet ejection weight that can be held. It shall be set and measured at intervals of 2 or less, and the maximum value of the adhesive force during this period is taken as the adhesive force of the particles. If there is too much ink, the adhesiveness will decrease.
Specifically, the particles that do not substantially exhibit tackiness are, in accordance with JIS Z 0237, 0.05 N / 10 mm or less, more preferably 0.01 N / 10 mm or less, and most preferably the weight of the holdable ink / It is a particle in which it is difficult to prepare a test piece due to insufficient adhesive strength within the range of the particle weight ratio.
The adhesive strength of Samples A to C was measured by the above method, and the results are shown in Table 3.

Regarding sample A, even when ink was ejected, it did not show tackiness and could not be measured. Sample A corresponds to particles that do not substantially exhibit tackiness, and is preferably used with the second particles.
FIG. 13 shows the adhesion measured for Samples B and C. In sample B, the adhesive strength is small and can be used as the second particles, but in sample C, the adhesive strength is high, and if this is used as the second particles, it is considered that blocking cannot be effectively prevented.

  If such non-adhesive or low-adhesive particles 17 are supplied onto the ink receptive particle layer 16A, then the liquid component of the ink is absorbed and pushed into the ink receptive particle layer 16A by a fixing process or the like. Even so (see FIG. 4), the non-adhesive (low-adhesive) particles 17 are exposed to a lower adhesiveness than before the particles 17 are supplied. Therefore, even if the recording medium 8 after image formation is stacked, the non-adhesive (low-adhesive) particles 17 function as spacers, and the occurrence of blocking is suppressed (see FIG. 5).

  It should be noted that the application amount (coverage) of the second particles 17 is the adhesiveness of the ink receiving particles 16 that develops when ink is applied, the liquid absorbency or adhesiveness of the second particles 17 that are used, and the like. However, it is desirable that the ink receiving particle layer 16A be dispersed so that the area of 30% or more of the ink receiving particle layer 16A is covered with the second particles 17 so that blocking can be reliably suppressed. The supply amount of the second particles 17 is adjusted by, for example, the rotation speed of the supply roll 15A.

Further, by controlling the supply amount of the second particles 17 to the ink receiving particle layer 16A, in addition to the blocking preventing effect, the surface state of the ink receiving particle layer 16A, that is, the surface state of the image can be changed. Is possible. That is, when the supply amount of the second particles 17 is increased (for example, 0.4 mg / cm ² or more and 4.0 mg / cm ² or less), the unevenness of the surface of the ink receiving particle layer 16A is flattened, and the glossiness of the surface is increased. Improved finish. If the supply amount of the second particles 17 is further increased, image fastness can be secured. On the other hand, when the supply amount of the second particles 17 is reduced (for example, 0.05 mg / cm ² or more and 0.4 mg / cm ² or less), the unevenness of the surface of the ink receiving particle layer 16A is hardly flattened (rough surface). , The glossiness of the surface is lowered and the matte finish is obtained.

From another viewpoint, when the unevenness of the surface of the ink receiving particle layer 16A is large (for example, when a recording medium having an uneven surface such as electrophotographic plain paper or high-quality printing paper is used) It is possible to cope with the problem by increasing the supply amount of the second particles 17 in order to increase the surface coverage.
Since the second particles 17 form an outermost layer after fixing, it is preferable that the second particles 17 have as high a light transmittance as possible. In addition, when the Tg of the ink receiving particles 16 used is high, or when the gloss is weak even when heated, the degree of gloss can be controlled by supplying the second particles whose surface properties are easy to control. Possible

  Examples of the material (resin material) constituting the second particles 17 as described above include styrenes such as styrene, parachlorostyrene, α-methylstyrene, α-ethylslen, methyl acrylate, ethyl acrylate, and acrylic. N-propyl acid, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, butyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate alkyl ester, phenyl acrylate Esters having a vinyl group, such as esters, alkyl methacrylates, phenyl methacrylates, cycloalkyl methacrylates, alkyl crotonates, dialkyl itaconates and dialkyl maleates, Vinyl nitriles such as nitrile, methacrylonitrile, vinyl ethers such as vinyl methyl ether, vinyl isobutyl ether, vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, vinyl cyclohexane, vinyl naphthalene, vinyl naphthalene derivatives, Polymers such as monomers such as polyolefins such as ethylene, propylene, and butadiene, or copolymers obtained by combining two or more of these, or a mixture thereof, as well as epoxy resins, polyester resins, polyurethane resins, polyamide resins, Non-vinyl condensation resins such as cellulose resins and polyether resins can be used. Among these, polyethylene (melting point: 125 ° C. to 130 ° C., Showa Denko), polyethylene terephthalate, polybutylene terephthalate, polypropylene (melting point: 150 ° C. to 160 ° C., Montelu), and polystyrene (glass transition point: 100 ° C. to 110 ° C.) , Sumitomo Chemical).

  The melting point or glass transition temperature (Tg) of the second particles 17 is preferably 40 ° C. or higher and 90 ° C. or lower, and more preferably 50 ° C. or higher and 70 ° C. or lower.

  The particle diameter of the second particles 17 is preferably 0.5 μm or more and 60 μm or less, more preferably 1 μm or more and 30 μm or less, and further preferably 3 μm or more and 15 μm or less in terms of a sphere-converted average particle diameter.

  The second particles 17 are desirably externally added with inorganic particles and resin particles on the surfaces thereof. Examples of inorganic particles include silica, titanium dioxide, tin oxide, molybdenum oxide, and the like. Examples of the resin particles include particles of the material types listed above. Inorganic particles that have been subjected to a hydrophobic treatment using a silane coupling agent, a titanium coupling agent, or the like can also be used.

(E) Fixing After the second particles 17 are supplied onto the ink receptive particle layer 16A, the ink receptive particle layer 16A and the first receptive particle layer 16A on the recording medium 8 are contacted between the heating roll 25A and the pressure roll 25B. Since the second particles are heated and melted by the heating roll 25A and pressure is applied, they are reliably fixed to the recording medium 8. Note that heating is not always necessary, and fixing may be performed only by pressing.

  At this time, the second particles 17 are pushed into the interparticle voids in the ink receiving resin particle layer 16. When the second particles 17 are pushed into the gaps between the ink receiving particles, the heat energy from the heating roll 25A is directly conducted by the second particles 17 to the particles inside the ink receiving particle layer. It is presumed that this contributes to softening / melting, that is, fixing of the ink receiving particles.

Here, it is also possible to adjust the texture of the image by controlling the fixing temperature. That is, even if the amount of the second particles dispersed (the density of the second particles 17 on the ink receiving particle layer 16A) is about the same, as shown in FIG. The finish, (B) semi-gloss, and (C) high gloss texture can be imparted.
In the case of semi-gloss, there is a possibility that the releasability at the time of fixing may be a problem, and therefore a release agent (for example, silicon oil) or the like may be supplied to the surface of the heating roll 25A.

Further, by controlling the supply amount of the second particles 17 and the fixing temperature, it is possible to control not only the anti-blocking effect but also the texture of the surface with higher accuracy. For example, the supply amount of the second particles 17 is decreased and the fixing temperature is set higher (FIG. 7A), or the supply amount of the second particles 17 is increased and the fixing temperature is lowered. (FIG. 7B), high gloss can be achieved. Further, if the supply amount of the second particles 17 is increased and the fixing temperature is set higher (FIG. 7C), the second particles are melted to flatten the surface and become highly glossy. . In this case, the effect of improving the fastness of the ink image can be obtained.
After the fixing process, the recording medium is discharged to a tray or the like.

On the other hand, the residual particles remaining on the surface of the intermediate transfer body 12 after the ink receptive particle layer 16A is peeled are collected by a cleaning device 24 equipped with a blade 24A (see FIG. 1). The recovered residual particles may be reused.
After cleaning, the surface of the intermediate transfer body 12 is charged again by the charging device 28. A static eliminator may be disposed between the cleaning device 24 and the charging device 28. For example, a conductive roll is used as a charge removal device, and is sandwiched between the driven roll 31 (ground), and a voltage of about ± 3 kV and about 500 Hz is applied to the surface of the intermediate transfer body 12 to discharge the surface of the intermediate transfer body 12.
By repeating the steps (A) to (E), an image is formed on the next recording medium.

-Second embodiment-
FIG. 8 is a schematic configuration diagram illustrating a recording apparatus according to the second embodiment. In the recording apparatus 40, the recording medium 8 is supported by a rotating drum-shaped support body 27. The drum-shaped support 27 forms a contact point with the pressure roll 22B via the intermediate transfer body 12, and forms a contact point with the heating roll 25A containing the heating source 25C on the opposite side rotated by 180 ° C.
The charging device 28, the first particle supply device 18, the ink jet recording head 20, the fixing device 25, and the cleaning device 24 are the same as those in the first embodiment. The second particle supply device 15 is a developing device type including the supply roll 15A and the charging blade 15B shown in FIG.

  When an image is formed on the recording medium 8 using the recording apparatus 40 according to this embodiment, (A) supply of ink receiving particles (formation of ink receiving particle layer) and (B) application of ink are described above. Since this is the same as the case where image formation is performed by the recording apparatus 10 according to the first embodiment, description thereof is omitted.

  A transparent liquid or ink is applied to the ink receptive particle layer 16A on the intermediate transfer body 12 from each of the heads 21 and 20 at predetermined positions based on the image information. Thereafter, the intermediate transfer body 12 is sandwiched between the recording medium 8 supported by the rotating support body 27 and the pressure roll 22B, and pressure is applied thereto. The ink receptive particle layer 16A is transferred to the entire surface of the recording medium 8 by the adhesiveness developed in the ink receptive particle layer 16A by applying the transparent liquid and the ink. In addition, a heat source may be provided on the pressure roll 22B or the support 27, and transfer may be performed by pressure and heating.

  The recording medium 8 to which the ink receptive particle layer 16 </ b> A has been transferred is supplied with the second particles 17 by the second particle supply device 15. Further, fixing is performed between the support 27 and the heating roll 25A containing the heating source 25C by heating and pressing. In this case as well, the occurrence of blocking by the second particles 17 is suppressed, the surface state of the image is controlled by adjusting the supply amount of the second particles 17 and the fixing temperature, and further, the fastness is imparted. Is also possible.

-Other forms-
In the first and second embodiments, a transparent liquid and ink are applied to the ink receiving particle layer 16A on the intermediate transfer body 12 so that the entire ink receiving particle layer 16A exhibits adhesiveness. Although the case where the entire surface is transferred has been described, the transfer may be performed without supplying the transparent liquid.
In this case, in the ink receptive particle layer 16 </ b> A, adhesiveness is developed only in the image portion to which ink is applied, and is transferred to the recording medium 8. Therefore, if the second particles 17 are supplied onto the recording medium 8 after the transfer, the second particles 17 adhere to the image portion and the adhesiveness is lowered, and the occurrence of blocking is suppressed.

  In addition, you may collect | recover the 2nd particle | grains 17 scattered by the non-image part. For example, if the second particles 17 are charged and dispersed, the ink receptive particle layer 16 </ b> A transferred as an image portion on the recording medium 8 exhibits adhesiveness, so that the second particles 17 adhere. On the other hand, in the non-image area, the ink receptive particle layer 16A is not transferred and the recording medium 8 is exposed, so the second particles 17 do not adhere. Therefore, for example, as shown in FIG. 9, if a collection drum 32 charged with a polarity opposite to that of the second particles 17 is provided between the second particle supply device 15 and the fixing device 25, the ink receiving property is improved. The second particles 17B in the non-image area where the particle layer 16A is not formed can be electrostatically recovered. The second particles 17B recovered by the recovery drum 32 may be recovered by the recovery device 34 and reused.

  Further, the second particles 17 may be selectively applied to the image portion of the ink receiving particle layer 16A transferred onto the recording medium 8. For example, an IOT (image output device) is linked to the second particle supply device 15, and the second particles 17 are selectively supplied to the image portion of the ink receiving particle layer 16A based on the image information of the IOT. Is possible.

1 is a schematic configuration diagram illustrating a recording apparatus according to a first embodiment. It is the schematic which shows an example (developer type) of a 2nd particle supply apparatus. It is the schematic which shows the other example (anilox roll type) of a 2nd particle supply apparatus. FIG. 3 is a diagram schematically showing an ink receiving particle layer and second particles on a recording medium after fixing. It is a figure which shows that a 2nd particle | grain becomes a spacer. It is a figure which shows that a surface state changes with fixing temperature. It is a figure which shows that a surface state is controlled according to the supply amount of 2nd particle | grains, and fixing temperature. It is a schematic block diagram which shows the recording device which concerns on 2nd Embodiment. It is a schematic block diagram which shows an example of the apparatus which collect | recovers 2nd particle | grains. It is the schematic which shows the method of measuring the absorptivity of the particle | grain with respect to the liquid component of an ink. It is a figure which shows the pattern of the ink which drops on a particle layer, when measuring the absorptivity of the particle | grain with respect to the liquid component of an ink. (A) Pattern A (B) Pattern B It is the schematic which shows the method of measuring the adhesiveness of the particle | grains expressed with respect to the liquid component of an ink. It is a graph which shows the adhesive force of samples B and C.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Recording device 12 Intermediate transfer body 15A Supply roll 15B Charging blade 15 Second particle supply device 16 Ink receiving particle 16A Ink receiving particle layer 17 Second particle 18A Supply roll 18B Charging blade 18 First particle supply device 20 Inkjet recording Head 21 Transparent liquid application head 22A Transfer roll 22 Transfer device 23 Support (plate)
24 Cleaning device 25A Heating roll 25B Pressure roll 25C Heating source 25 Fixing device 27 Support (drum-shaped)
28 Charging Device 30A Roller 31 Followed Roll 32 Recovery Drum 34 Recovery Device 40 Recording Device

Claims (4)

An intermediate transfer member;
First particle supply means for supplying ink receiving particles for receiving ink in a layer form on the intermediate transfer member;
An ink applying means for applying ink to the layer of the ink receiving particles supplied on the intermediate transfer member;
Transfer means for transferring the layer of the ink receiving particles to which the ink has been applied to a recording medium;
The ink receptive particle layer transferred to the recording medium has less absorbability with respect to the liquid component of the ink or less adhesiveness when the ink liquid component is absorbed than the ink receptive particle. A second particle supply means for supplying two particles;
Pressing means for pressing the recording medium supplied with the second particles;
A recording apparatus comprising:   The recording apparatus according to claim 1, wherein the pressing unit is a unit that presses and heats the recording medium supplied with the second particles.   It further has a particle removing means for removing a part of the second particles supplied from the second particle supplying means to the recording medium between the second particle supplying means and the pressing means. The recording apparatus according to claim 1 or 2.   The recording apparatus according to claim 3, wherein the particle removing unit is a unit that electrostatically removes the second particles.