JP2010105365A - Ink receptive particle, ink recording material, recording method, recording device and cartridge for storing ink receptive particle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink receptive particle which shows the inhibition of lowering of electrostatic chargeability without hindering the receptivity of ink, an ink recording material using the ink receptive particle, a recording method, a recording device and a cartridge for storing the ink receptive particle. <P>SOLUTION: The ink receptive particle contains a hydrophilic organic resin 111, a hydrophobic organic resin 112 and a block copolymer 113. The hydrophilic organic resin 111 has the ratio of a constituent unit derived from a polar monomer being 10 mol% or above and 90 mol% or below. The hydophobic organic resin 112 has the ratio of a constituent unit derived from the polar monomer being not less than 0 mol% to less than 10 mol%. The block copolymer 113 is a block copolymer with a constituent unit derived from the polar monomer and a constituent unit derived from a non-polar monomer. Further, the absolute value of a difference between the solubility parameter of the polar monomer of the block copolymer 113 and the solubility parameter of the polar monomer of the hydrophilic organic resin 111, is 2 or below. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ink receiving particle, an ink recording material, a recording method, a recording apparatus, and an ink receiving particle storage cartridge.

  In the recording method using ink, in order to perform recording on various recording media such as a permeable medium and a non-penetrable medium, a method of recording on an intermediate and then transferring to a recording medium has been proposed.

For example, ink receptive particles that receive ink containing a recording material, have a trap structure that traps at least the liquid component of the ink, and include ink absorbing resin, and intermediate transfer is performed. There has been proposed a recording apparatus in which ink is ejected onto a body and then transferred to a recording medium (see, for example, Patent Document 1).
Further, as the ink receptive particles, those comprising a hydrophilic organic resin and a hydrophobic organic resin have been proposed (for example, see Patent Document 2).
JP 2006-347085 A JP 2008-119919 A

An object of the present invention is to provide ink receptive particles in which a change in charging property with time is suppressed.
Another object of the present invention is to provide a recording material, a recording apparatus, and an ink receiving particle storage container using the ink receiving particles.

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

The invention according to claim 1
A hydrophilic organic resin;
A hydrophobic organic resin,
A block copolymer having a structural unit derived from a polar monomer and a structural unit derived from a non-polar monomer,
The absolute value of the difference between the solubility parameter (SP value) of the polar monomer of the block copolymer and the solubility parameter (SP value) of the polar monomer constituting the hydrophilic organic resin is 2 or less, Ink receiving particles that receive ink.

The invention according to claim 2
The ink receiving particles according to claim 1, wherein the polar monomer in the block copolymer has the same chemical structure as the polar monomer constituting the hydrophilic organic resin.

The invention according to claim 3
Ink,
Ink-receiving particles according to claim 1 or 2,
An ink recording material.

The invention according to claim 4
A supplying step of supplying the ink receiving particles according to claim 1 or 2 onto the intermediate transfer member;
An ink discharge step of discharging ink to the ink receiving particles supplied onto the intermediate transfer member;
A transfer step of transferring the ink receiving particles to a recording medium;
A fixing step of fixing the ink receiving particles transferred to the recording medium;
Is a recording method.

The invention according to claim 5
A supply step of supplying the ink receiving particles according to claim 1 or 2 onto a recording medium;
An ink ejection step for ejecting ink to the ink receiving particles supplied on the recording medium;
A fixing step of fixing the ink receiving particles supplied on the recording medium;
Is a recording method.

The invention according to claim 6
An intermediate transfer member;
A supply device for supplying the ink receiving particles according to claim 1 or 2 onto the intermediate transfer member;
An ink discharge device for discharging ink to the ink receiving particles supplied onto the intermediate transfer member;
A transfer device for transferring the ink receiving particles to a recording medium;
A fixing device for fixing the ink receiving particles transferred to the recording medium;
Is a recording apparatus.

The invention according to claim 7 provides:
A supply device for supplying the ink receiving particles according to claim 1 or 2 onto a recording medium;
An ink ejection device for ejecting ink to the ink receiving particles supplied on the recording medium;
A fixing device for fixing the ink receiving particles supplied on the recording medium;
Is a recording apparatus.

The invention according to claim 8 provides:
An ink receptive particle storage container which is detached from the recording apparatus and stores the ink receptive particles according to claim 1.

  According to the first aspect of the present invention, it is possible to provide ink receiving particles in which the change in charging property with time is suppressed as compared with the case where only the hydrophilic organic resin and the hydrophobic organic resin are included.

  The invention according to claim 2 can provide ink receptive particles in which the change in charging property with time is further suppressed as compared with the case without this configuration.

  According to the third aspect of the present invention, it is possible to provide an ink recording material that can be stably charged with respect to a recording medium as compared with the case without this configuration.

  According to the fourth and fifth aspects of the present invention, it is possible to provide a recording method capable of stably recording on a recording medium in comparison with a case where the present configuration is not provided.

  According to the inventions according to claims 6 and 7, it is possible to provide a recording apparatus capable of stably recording on a recording medium in comparison with the case where the present configuration is not provided.

  According to the eighth aspect of the present invention, it is possible to provide an ink-receptive particle container capable of stably recording on a recording medium.

  Hereinafter, this embodiment will be described in detail.

<Ink receiving particles>
The ink receiving particles of the present embodiment include (1) a hydrophilic organic resin, (2) a hydrophobic organic resin, and (3) a structural unit derived from a polar monomer and a structure derived from a nonpolar monomer. And a block copolymer having units. Further, in the ink receiving particles of this embodiment, the solubility parameter (SP value) of the polar monomer constituting the hydrophilic organic resin (1) and the polar monomer of the block copolymer (3) are used. The absolute value of the difference from the body solubility parameter (SP value) is 2 or less.

  The hydrophilic organic resin preferably has a ratio of structural units derived from a polar monomer of 10 mol% or more and 90 mol% or less, and the hydrophobic organic resin is derived from a polar monomer. The ratio of the structural units is preferably 0 mol or more and less than 10 mol%.

  The ink receiving particles of the present embodiment receive ink components when in contact with ink. Here, the ink receptivity indicates holding at least a part (at least a liquid component) of the ink component.

  In the ink receptive particles of the present embodiment, the hydrophilic organic resin contained in the particles absorbs moisture in the atmosphere during storage or gives ink liquid components when ink is applied to the ink receptive particles. Even when the ink is absorbed, the presence of the hydrophobic organic resin ensures the chargeability on the surface of the ink receiving particles without hindering the ink reception.

Furthermore, the ink receiving particles of this embodiment include a block copolymer, which is a structural unit derived from a polar monomer (hereinafter referred to as “hydrophilic portion”) and nonpolar (hydrophobic). And a structural unit derived from a monomer (hereinafter referred to as “hydrophobic site”). Since the hydrophilic part of the block copolymer is oriented to the hydrophilic organic resin and the hydrophobic part of the block copolymer is oriented to the hydrophobic organic resin, the hydrophilic organic resin and the hydrophobic organic resin in the ink receiving particles It has the effect | action which couple | bonds.
In particular, the solubility parameter (SP value) of the polar monomer of the block copolymer has an absolute value of 2 or less that is different from the solubility parameter (SP value) of the polar monomer constituting the hydrophilic organic resin. Therefore, the hydrophilic portion of the block copolymer is easily adapted to the hydrophilic organic resin, and the bond becomes stronger.
In the following, first, the particle morphology of the ink receiving particles will be described, and then the action of these particles will be described. The action of the ink receiving particles is speculated and does not limit the present invention.

(Particle morphology of ink receiving particles)
The particle form of the ink receiving particles of this embodiment will be described.
As long as the ink receiving particles of the present embodiment are particles containing the hydrophilic organic resin, the hydrophobic organic resin, and the block copolymer, the shape of each of the hydrophilic organic resin and the hydrophobic organic resin is as follows. Is not particularly limited.

  For example, primary particles in which the hydrophilic organic resin is a binder resin and the hydrophobic organic resin is contained in the form of particles may be used, or the hydrophobic organic resin may be contained in a matrix of the hydrophilic organic resin. May be a primary particle containing a domain, or a composite particle in which both the hydrophilic organic resin and the hydrophobic organic resin are in the form of particles and a plurality of these particles are aggregated. There may be. Hereinafter, the primary particles or composite particles may be referred to as “mother particles”.

  An example of a specific configuration of the ink receiving particles of this embodiment is shown in FIGS. FIG. 1 is a diagram for explaining ink-receptive particles 100 in which the mother particles are in the form of primary particles. FIG. 2 is a diagram illustrating the ink receiving particles 110 in which the mother particles are in the form of composite particles.

FIG. 1 is a diagram for explaining ink receiving particles 100 in which the mother particles are in the form of primary particles.
The ink receiving particles 100 in FIG. 1 include a hydrophobic organic resin 102 and a block copolymer 103 in a hydrophilic organic resin 101 as a binder resin. The hydrophilic site B in the block copolymer 103 is oriented to the hydrophilic organic resin 101, and the hydrophobic site A is oriented to the hydrophobic organic resin 102. Thus, the block copolymer 103 bonds the hydrophilic organic resin 101 and the hydrophobic organic resin 102 together.

  As shown in FIG. 1, when ink is applied to the ink receiving particles 100 in which the mother particles are primary particles, the ink adheres to the ink receiving particles 100, and at least the liquid component of the ink is absorbed by the hydrophilic organic resin. To be liquidated. In this way, the ink receiving particles 100 receive ink. An image is recorded by transferring the ink receiving particles 100 that have received the ink to a recording medium.

  From the viewpoint of absorbing the liquid component of the ink by the hydrophilic organic resin of the ink receiving particles 100 as described above, it is desirable to increase the content ratio of the hydrophilic organic resin in the ink receiving particles 100. Therefore, in the present embodiment, the ink receiving particles whose mother particles are primary particles include a large amount of hydrophilic organic resin 101 as shown in FIG. 1, and the hydrophobic organic resin 101 is contained in the hydrophilic organic resin 101. 102 and the block copolymer 103 are desirable. However, the embodiment in which the hydrophobic organic resin 102 is included in a larger amount than the hydrophilic organic resin 101 and the hydrophilic organic resin 101 and the block copolymer 103 are included in the hydrophobic organic resin 102 is also included in the present embodiment. The

After the transfer of the ink receiving particles 100, the hydrophilic organic resin 101 constituting the ink receiving particles 100 can function as a resin that binds or covers the recording material contained in the ink.
Further, after the transfer of the ink receiving particles 100, the organic resin component constituting the ink receiving particles 100 is an insoluble component such as a pigment as a recording material, and fixing of ink (for example, pigment ink) using dispersed particulate matter. It is also possible to fulfill the function of improving the property (scratch resistance).

  The hydrophilic organic resin 101 preferably has a ratio of structural units derived from polar monomers of 10 mol% or more and 90 mol% or less, and the other structural units are not limited. Details of the hydrophilic organic resin will be described later.

  The hydrophobic organic resin 102 preferably has a ratio of structural units derived from polar monomers of 0 mol or more and less than 10 mol%, and the other structural units are not limited. Details of the hydrophobic organic resin will be described later.

  Furthermore, the block copolymer 103 has a structural unit derived from a polar monomer (hydrophilic site B) and a structural unit derived from a nonpolar monomer (hydrophobic site A). If the absolute value of the difference between the solubility parameter (SP value) of the polar monomer 103 and the solubility parameter (SP value) of the polar monomer constituting the hydrophilic organic resin 101 is 2 or less, other structures The unit is not limited. Details of the block copolymer will be described later.

The average spherical particle diameter of the ink receiving particles 100 is, for example, in the range of 0.1 μm to 75 μm.
When the average spherical particle diameter of the ink receiving particles 100 is in the above range, compared to the case without this configuration, the smoothness of the image is excellent, and the desired handling on the transfer body is achieved by improving the handling of the powder. The powder can be supplied to the position, and high image quality is achieved.

  The sphere-converted average particle diameter is obtained as follows. The optimum measurement method differs depending on the particle size, but various methods can be used such as, for example, dispersing particles in a liquid and obtaining the particle size by the light scattering principle, and obtaining a projected image of the particles by image processing. Examples of methods that can be used for general purposes include the Microtrac UPA method and the Coulter counter method. Hereinafter, the same applies to the present embodiment.

  In the ink receiving particles 100 in which the mother particles are in the form of primary particles, the hydrophobic organic resin 102 may have a particle shape or a domain shape. When the hydrophobic organic resin 102 has a particle shape, The average spherical particle diameter of the conductive organic resin particles is, for example, in the range of 0.01 μm to 10 μm.

  The particle size of the hydrophobic organic resin 102 contained in the hydrophilic organic resin 101 is, for example, that ink-receptive particles are embedded in a resin, a flaky sample is formed using a diamond cutter, and the sample is transmitted. It can be measured by observing using an electron microscope or the like. In addition, when the process dye | stained using osmium oxide or ruthenium oxide etc. is added, it will become possible to discriminate | determine more clearly the interface of a hydrophobic particle and a hydrophilic particle.

The ink receiving particles 100 in which the mother particles are primary particles as shown in FIG. 1 can be prepared as follows.
The ink receiving particles 100 in which the hydrophobic organic resin 102 is contained in the form of particles in the hydrophilic organic resin 101 include, for example, melt kneading a hydrophilic organic resin, a hydrophobic organic resin, or a block copolymer using an extruder or the like. And then pulverizing with a pulverizer such as a jet mill.

The particle size of the ink receiving particles 100 can be adjusted by pulverization conditions, classification conditions, and the like.
In addition, the particle size of the hydrophobic organic resin 102 in the ink receiving particles 100 can be adjusted by the composition, molecular weight, added amount ratio, etc. of the hydrophilic organic resin and the hydrophobic organic resin.

The ink receiving particles 100 may be configured to include materials other than the hydrophilic organic resin 101 and the hydrophobic organic resin 102 as necessary. Examples of the material include inorganic materials, porous materials, and charging materials. Examples thereof include a control agent, a wax material, a flocculant, and a lubricant.
When inorganic particles are contained in the ink receiving particles 100, the particle diameter of the inorganic particles is a sphere-converted average particle diameter, for example, 10 nm or more and 30 μm or less.

  Further, for example, inorganic particles 104 or the like may be adhered to the surface of the ink receiving particles 100. The particle size of the inorganic particles 104 is a sphere equivalent average particle size, for example, not less than 10 nm and not more than 1 μm.

FIG. 2 is a diagram illustrating the ink receiving particles 110 in which the mother particles are in the form of composite particles.
The ink receptive particles 110 in FIG. 2 are composite particles in which hydrophilic organic resin particles 111 and hydrophobic organic resin particles 112 are bonded by a block copolymer 113. In this composite particle, a void structure is formed by voids between the particles. Furthermore, the inorganic particles 114 may be attached to the surface of the composite particles.

When ink is applied to the ink receiving particles 110, which are the composite particles in FIG. 2, first, the ink adheres to the ink receiving particles 110, and at least the liquid component of the ink constitutes the ink receiving particles 110 of the composite particles. The particles are trapped by the voids between the particles (hereinafter, the interparticle voids may be referred to as “trap structures”). At this time, a recording material such as a color material among the ink components is attached to the surface of the ink receiving particles 110 or captured by a trap structure. In this way, the ink receiving particles 110 receive ink. Then, recording is performed by transferring the ink receiving particles 110 that have received the ink to a recording medium.
The trapping of the ink liquid component by this trapping structure is a physical and / or chemical trapping by voids between particles (physical particle wall structure).

  By forming the mother particles into composite particles in which a plurality of particles are aggregated, the ink liquid component is absorbed and held by the hydrophilic organic resin, and the ink receiving particles 110 of the composite particles. Are also captured by voids (physical particle wall structure) between the particles constituting the.

  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. And the magnitude | size of this space | gap is a maximum aperture, for example, the range of 0.1 micrometer or more and 5 micrometers or less is mentioned. In particular, the size of the voids is preferably a size capable of trapping a recording material, particularly, for example, a pigment having a volume average particle 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.

  Thus, the trap structure preferably traps the recording material in addition to the liquid component of the ink components. 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).

After the transfer of the ink receiving particles 110, the hydrophilic organic resin 111 constituting the ink receiving particles 110 can function as a resin that binds or covers the recording material contained in the ink. It is.
Further, after the transfer of the ink receiving particles 110, the organic resin component constituting the ink receiving particles 110 is an insoluble component such as a pigment as a recording material, and fixing of ink (for example, pigment ink) using dispersed particulate matter. It is also possible to fulfill the function of improving the property (scratch resistance).

The average sphere equivalent particle diameter of the ink receiving particles 110 in which the mother particles are in the form of composite particles is, for example, in the range of 0.1 μm to 75 μm.
When the average spherical particle diameter of the ink receiving particles 110 is in the above range, compared to the case without this configuration, the image smoothness is excellent, and the desired handling on the transfer body is achieved by improving the powder handling properties. The powder can be supplied to the position, and high image quality is achieved.

  In the ink receiving particles 110 in which the base particles are in the form of composite particles, the average spherical particle diameter of the hydrophilic organic resin particles 111 is, for example, in the range of 10 nm to 30 μm.

  Further, in the ink receiving particles 110 in which the mother particles are in the form of composite particles, the sphere equivalent average particle size of the hydrophobic organic resin particles 112 is, for example, in the range of 10 nm to 10 μm.

  Furthermore, in the ink receiving particles 110 in which the mother particles are in the form of composite particles, the particle size ratio between the hydrophilic organic resin particles 111 and the hydrophobic organic resin particles 112 is such that the ink receiving speed is improved and the chargeability after aging is increased. From the viewpoint of achieving both suppression of the decrease, the hydrophilic organic resin particles 111: hydrophobic organic resin particles 112 = 10: 1 or more and 1: 1 or less. In addition, the value calculated | required from the above-mentioned sphere conversion average particle diameter is employ | adopted for this particle size ratio.

When measuring the spherical equivalent average particle diameter of the hydrophilic organic resin particles 111 and the hydrophobic organic resin particles 112, for example, the ink receiving particles are embedded with a resin, and a flaky sample is formed using a diamond cutter or the like. This is possible by measuring and analyzing the sample using a transmission electron microscope or the like. In addition, when the process dye | stained using osmium oxide or ruthenium oxide etc. is added, it will become possible to discriminate | determine more clearly the interface of a hydrophobic particle and a hydrophilic particle.
Further, the dispersed particle size in the ink receiving particles can be controlled by the dispersed particle size in the emulsion state, and can be adjusted by obtaining the particle size of the emulsion solution during particle preparation, for example, by the light scattering principle. .

  The hydrophilic organic resin 111 preferably has a ratio of structural units derived from polar monomers of 10 mol% or more and 90 mol% or less, and the other structural units are not limited. Details of the hydrophilic organic resin will be described later.

  The hydrophobic organic resin 112 preferably has a ratio of structural units derived from polar monomers of 0 mol or more and less than 10 mol%, and the other structural units are not limited. Details of the hydrophobic organic resin will be described later.

  Furthermore, the block copolymer 113 has a structural unit derived from a polar monomer (hydrophilic site B) and a structural unit derived from a nonpolar monomer (hydrophobic site A). The solubility parameter (SP value) of the polar monomer No. 113 has other structures as long as the absolute value of the difference with respect to the solubility parameter (SP value) of the polar monomer constituting the hydrophilic organic resin 111 is 2 or less. The unit is not limited. Details of the block copolymer will be described later.

The ink receiving particles 110 that are composite particles may include a material other than the hydrophilic organic resin particles 111 and the hydrophobic organic resin particles 112 as third particles (not shown) as necessary. Often, examples of the material include inorganic materials, porous materials, wax materials, flocculants, and lubricants.
When inorganic particles are included as the third particles, the particle diameter of the inorganic particles is a spherical equivalent average particle diameter, for example, 10 nm or more and 30 μm or less.

  Further, the hydrophilic organic resin particles 111 and the hydrophobic organic resin particles 112 may contain a third component in addition to the hydrophilic organic resin and the hydrophobic organic resin, for example, an inorganic material, a porous material, a charge control agent, Examples thereof include a wax material, a flocculant, and a lubricant.

  Furthermore, for example, inorganic particles 114 may be attached to the surface of the ink receiving particles 110. The particle size of the inorganic particles 114 is a spherical equivalent average particle size, for example, not less than 10 nm and not more than 1 μm.

  When the ink receiving particles 110 that are composite particles include other particles in addition to the hydrophilic organic resin particles 111 and the hydrophobic organic resin particles 112, the mass ratio of the blending is, for example, when the other particles are inorganic particles For example, hydrophilic organic resin particles: other particles = 5: 1 or more and 1:10 or less can be mentioned.

The ink receiving particles 110 that are composite particles have a BET specific surface area (N ₂ ) of, for example, in the range of 1 m ² / g to 750 m ² / g.

The ink receiving particles 110 in which the hydrophilic organic resin particles 111 and the hydrophobic organic resin particles 112 illustrated in FIG. 2 are bonded by the block copolymer 113 can be manufactured as follows.
An emulsion solution of a hydrophilic organic resin and an emulsion solution of a hydrophobic organic resin are prepared. At this time, the block copolymer is added to at least one emulsion solution. These emulsion solutions can be prepared by mixing and then drying using a spray dryer or the like. The block copolymer is preferably added as a dispersant for dispersing the hydrophobic organic resin.

  The particle diameters of the hydrophilic organic resin particles 111 and the hydrophobic organic resin particles 112 constituting the composite particles can be adjusted by the respective emulsion particle diameters. Specifically, each resin composition, a solvent, a dispersing agent composition, the resin ratio in an emulsion solution, etc. are mentioned.

  The particle size of the ink receiving particles 110 should be adjusted according to the drying conditions of the spray dryer (for example, the solid content concentration in the emulsion and the spraying pressure) and the classification conditions of the airflow classifier (for example, the edge cutting angle and the blowing pressure). Can do.

  The ink receiving particles 110 in which the mother particles are 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 the particle shape remains to some extent and voids are retained between the particles.

(Action of ink receiving particles)
The reason why the ink-receptive particles of the present embodiment having the above-described configuration can suppress the decrease in chargeability even after the elapse of time has not been clarified, but is presumed as follows.

  The ink receptive particles of the present embodiment absorb the liquid component of the ink with the hydrophilic organic resin and the chargeability is secured with the hydrophobic organic resin, so that the hydrophilic organic resin and the hydrophobic organic resin receive the ink. Must be present in the particles. The block copolymer has a function of binding a hydrophilic organic resin and a hydrophobic organic resin, for example, particles as ink receiving particles even after mixing with a carrier for charging. A stable charge can be realized without losing the form.

  In addition, the hydrophilic position of the block copolymer according to the present embodiment is oriented on the inner side of the hydrophilic organic resin, and the hydrophobic portion is arranged outside the hydrophilic organic resin. As a result, the surface of the hydrophilic organic resin is hydrophobized by the block copolymer, and the chargeability is improved.

Further, in the case where the ink receiving particles are composite particles illustrated in FIG. 2, the hydrophilic organic resin particles 111 and the hydrophobic organic resin particles 112 are bonded by the block copolymer 113. The gaps formed in the above are maintained even after spraying, and the liquid absorption speed can be maintained over time.
When the ink receptive particles are composite particles exemplified in FIG. 2, the ink liquid component is absorbed and held by the hydrophilic organic resin, and the ink receptive particles 110 of the composite particles. Are also captured by voids (physical particle wall structure) between the particles constituting the. Therefore, from the viewpoint of improving the liquid absorption speed, ink receiving particles in the form of composite particles illustrated in FIG. 2 are preferable.

Further, when the ink receiving particles are mixed and stirred together with the carrier in order to charge the ink receiving particles, the ink receiving particles receive a physical impact from the carrier. In the ink receiving particles of this embodiment, a hydrophilic organic resin and a hydrophobic organic resin are bonded to each other by a block copolymer, so that partial loss of the ink receiving particles is suppressed even when subjected to a physical impact from a carrier. It is done. Therefore, the charging of the ink receiving particles is stably performed, and the charged ink receiving particles with no partial omission are obtained.
Therefore, the ink-receptive particles in a stable charged state can be supplied onto the recording medium, and as a result, the optical density can be improved and bleeding can be prevented.

(Hydrophilic organic resin and hydrophobic organic resin)
Next, a hydrophilic organic resin and a hydrophobic organic resin will be described.
The hydrophilic organic resin preferably has a ratio of structural units derived from polar monomers of 10 mol% or more and 90 mol% or less.

When the ratio of the structural unit derived from the polar monomer is in the above range, the ink is easily captured (trapped) in the particles and in the interparticle spaces, compared to the case where this structure is not included, and the configuration of the present embodiment Various inks can be received at a high speed as compared with the case where no ink is present. Also, printing at high speed is possible.
The hydrophilic organic resin is used by controlling the ratio of the polar monomer within the above range, regardless of the form of the base particles of the ink receiving particles.

Examples of the polar monomer include ethylene oxide groups, carboxy groups, sulfo groups, substituted or unsubstituted amino groups, hydroxyl groups, amide groups, imide groups, nitrile groups, ether groups, ester groups, and salts thereof. It is a mer.
For example, in the case of imparting positive chargeability, it is desirable to use a monomer having a chlorination structure such as a (substituted) amino group, a (substituted) pyridine group, an amine salt thereof, or a quaternary ammonium salt. 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.

  Here, the “structural unit derived from the polar monomer” means a structural unit in the polymer after the polar monomer undergoes a polymerization reaction.

In addition, the ratio of the structural unit derived from the polar monomer in hydrophilic organic resin is calculated | required as follows.
First, the constitution of the organic component is identified from analysis techniques such as mass spectrometry, NMR, and IR. Thereafter, the acid value and base value of the organic component are measured according to JIS K0070 (1992) or JIS K2501 (2003). 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 resin is preferably a weak liquid-absorbing resin. This weakly liquid-absorbent resin means, for example, a lyophilic resin that can absorb liquids of several percent (≈5%) to several hundred percent (≈500%) with respect to the resin mass when water is absorbed as a liquid. Means.
When the liquid absorbing property of the weak liquid absorbing resin is within the above range, the ink holding ability of the ink receiving particles is improved, and stable ink receiving particles that do not depend much on the external environment are obtained.

  In order to make the hydrophilic organic resin a weakly hydrophilic organic resin, it is desirable to use a copolymer composed of both a polar monomer and a hydrophobic monomer. In addition to the monomer, a graft copolymer or block copolymer in which a unit such as a polymer / oligomer structure is copolymerized with another unit using a starting material may be used.

Here, the polar monomer is -OH, -EO unit (ethylene oxide group), -COOM (M is an alkali metal such as hydrogen, Na, Li, 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.) or the like.
Specific examples include 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, acrylamide, acrylic acid, methacrylic acid, unsaturated carboxylic acid, crotonic acid, maleic acid, and the like. In addition, as polar monomers, 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) maleic acid, Polymerizable carboxylic acids such as these, (partially) neutralized salts thereof, vinyl alcohols, vinyl pyrrolidone, derivatives such as vinyl pyridine, amino (meth) acrylate and dimethylamino (meth) acrylate, and further onium salts, acrylamide thereof And amides such as isopropyl acrylamide, polyethylene oxide chain-containing vinyl compounds, hydroxyl group-containing vinyl compounds, polyesters composed of polyfunctional carboxylic acids and polyhydric alcohols, especially trifunctional or higher acid such as trimellitic acid. Branched polyester containing more terminal carboxylic acid or hydroxyl containing, polyesters including polyethylene glycol structure, etc. may be mentioned.

The polar monomer in the hydrophilic organic resin preferably has a solubility parameter (SP value) of 11 or more.
The absolute value of the difference in solubility parameter (SP value) between the polar monomer in the hydrophilic organic resin and the polar monomer of the block copolymer described later is 2 or less, more preferably 0 or more and 1 .5 or less.

The solubility parameter (SP value) is a value calculated by the following formula of Fedors calculated from the evaporation energy (Δei) and the molar volume (Δvi) of atoms or atomic groups having a chemical structure. The same applies hereinafter.
Formula: [SP value = (ΣΔei / ΣΔvi) ^1/2 ]

  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. Examples of hydrophobic monomers include styrene derivatives such as styrene, α-methylstyrene, vinyltoluene, vinylcyclohexane, vinylnaphthalene, vinylnaphthalene derivatives, alkyl acrylate esters, phenyl acrylate esters, alkyl methacrylate esters, phenyl methacrylate esters. Mention may also be made of esters, methacrylic acid cycloalkyl esters, crotonic acid alkyl esters, itaconic acid dialkyl esters, maleic acid dialkyl esters, and derivatives thereof.

  Specific examples of the hydrophilic organic resin that is a copolymer of the polar monomer and the hydrophobic monomer include, for example, a styrene / alkyl (meth) acrylate / (meth) acrylic acid copolymer ( (Meth) acrylic acid ester copolymers, styrene / (meth) acrylic acid / (anhydrous) maleic acid copolymers, olefin copolymers such as ethylene / propylene (or modified products thereof, or carboxylic acid units by copolymerization) Introducted products), branched polyesters having improved acid value with trimellitic acid, polyamides, and the like are preferable.

  The hydrophilic organic resin may include, for example, a neutralized 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 for the hydrophilic organic resin to contain 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).

  The hydrophilic organic resin may be ion-crosslinked with ions supplied from the ink. Specifically, there are structural units containing carboxylic acids in the resin, such as copolymers containing carboxylic acids such as (meth) acrylic acid and maleic acid, and (branched) polyesters containing carboxylic acids. Can be made. 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 hydrophilic organic resin has a solubility parameter (SP value) of, for example, 9.5 or more, desirably 9.5 or more and 20 or less, and more desirably 9.5 or more and 15 or less.
The difference in solubility parameter (SP value) between the hydrophilic organic resin and the hydrophobic organic resin described later is, for example, 1 or less, desirably 0.1 or more and 0.8 or less, and more desirably 0.2. It is 0.6 or less.

  Here, regardless of the form of the base particles of the ink receiving particles, the content ratio of the hydrophilic organic resin in the whole ink receiving particles is 75% or more and 100% or less.

The content ratio of the hydrophilic organic resin 101 in the ink receiving particles 100 whose primary particles are primary particles illustrated in FIG. 1 is obtained as follows.
Observed using a transmission electron microscope as in the particle diameter measurement method described above, and can be obtained by image analysis.

The content ratio of the hydrophilic organic resin 111 in the ink receiving particles 110 whose shape of the mother particles is composite particles illustrated in FIG. 2 is obtained as follows.
It can be obtained by observing with a transmission electron microscope as in the particle diameter measuring method described above and analyzing the image.

  It is desirable to apply a transparent resin as the hydrophilic organic resin from the viewpoint of functioning as a protective layer after fixing.

Next, the hydrophobic organic resin will be described.
As for hydrophobic organic resin, it is desirable for the ratio of the structural unit derived from a polar monomer to be 0 mol% or more and less than 10 mol%.
The hydrophobic organic resin is used by controlling the ratio of the polar monomer within the above range regardless of the form of the base particles of the ink receiving particles.

  The hydrophobic organic resin means, for example, a resin having a liquid absorbing property capable of absorbing less than 5% of the resin mass when water is absorbed as a liquid.

  When the ratio of the polar monomer is within the above range, the hydrophilic organic resin particles contained in the mother particles absorb moisture in the atmosphere by storage or absorb the liquid component of ink by ink application. Even in this case, the charging property on the surface of the ink receiving particles is ensured. Therefore, even if the ink receiving particles are transferred onto the intermediate transfer body, the ink receiving particles are not detached from the intermediate transfer body, and an image with suppressed image disturbance can be formed.

The hydrophobic organic resin may be a homopolymer or a copolymer (copolymer).
When the hydrophobic organic resin is a homopolymer, it is a homopolymer composed only of a nonpolar monomer (hydrophobic monomer), and the proportion of structural units derived from the polar monomer is 0 mol%. .
When the hydrophobic organic resin is a copolymer, there are two embodiments. One is a copolymer composed of a plurality of types of nonpolar monomers (hydrophobic monomers), and the proportion of structural units derived from the polar monomers is 0 mol%. The other is a copolymer composed of a polar monomer and a nonpolar monomer, where the proportion of structural units derived from the polar monomer is greater than 0 mol%.

  As the polar monomer in the hydrophobic organic resin, the polar monomer described in the hydrophilic organic resin can be applied.

  Examples of hydrophobic monomers include olefin compounds such as ethylene, propylene, and butadiene, styrene derivatives such as styrene, α-methylstyrene, α-ethylstyrene, and vinyltoluene, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and acrylonitrile. , Vinyl acetate, methyl acrylate, ethyl acrylate, butyl acrylate, lauryl methacrylate, vinyl cyclohexane, vinyl naphthalene, vinyl naphthalene derivatives, alkyl acrylate ester, acrylic acid phenyl ester, methacrylic acid alkyl ester, methacrylic acid phenyl ester, Methacrylic acid cycloalkyl ester, crotonic acid alkyl ester, itaconic acid dialkyl ester, maleic acid dialkyl ester, etc.

  Specific examples of the hydrophobic organic resin include vinyl resins (for example, styrene- (meth) acrylic acid copolymer, (meth) acrylic acid alkyl ester- (meth) acrylic acid copolymer), and polyester resins. (Eg, polyethylene terephthalate, polybutylene terephthalate, etc.), silicone resin (eg, organopolysiloxane), fluorine resin (eg, vinylidene fluoride resin, polytetrafluoroethylene, tetrafluoroethylene / perfluoroalkylvinyl copolymer, tetrafluoro) (Ethylene / ethylene copolymer and the like) are preferred.

  The solubility parameter (SP value) of the whole hydrophobic organic resin is, for example, less than 9.5.

  The ratio of the hydrophobic organic resin to the entire ink receiving particles is 0.1% by mass or more and 5% by mass or less regardless of the form of the mother particles.

The content ratio of the hydrophobic organic resin 102 in the ink receiving particles 100 whose primary particle shape is the primary particle illustrated in FIG. 1 is obtained as follows.
It can be obtained by observing with a transmission electron microscope as in the particle diameter measuring method described above and analyzing the image.

The content ratio of the hydrophobic organic resin 112 in the ink receiving particles 110 whose composite particles are composite particles illustrated in FIG. 2 is obtained as follows.
It can be obtained by observing with a transmission electron microscope as in the particle diameter measuring method described above and analyzing the image.

Furthermore, the surface treatment (partial hydrophobization treatment, specific functional group introduction treatment, etc.) may be performed on the hydrophobic organic resin particles configured to contain the hydrophobic organic resin.
Specifically, for example, an alkyl group can be introduced by treatment with a silylating agent such as trimethylchlorosilane or t-butyldimethylchlorosilane. In this reaction, dehydrochlorination occurs due to the silylating agent, and the reaction proceeds. Therefore, the reaction can be promoted by adding hydrochloric acid to make hydrochloric acid hydrochloride.
Further, surface treatment with aliphatic alcohols, higher fatty acids and derivatives thereof is also possible. Furthermore, 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 carboxyls Surface treatment with coupling agents having an anionic functional group such as acid is also possible.

The hydrophobic organic resin may contain a charge control agent. Examples of the charge control agent include inorganic oxides, organic compounds, and organometallic complexes.
Examples of the inorganic oxide as the charge control agent include titanium oxide, tin oxide, zinc oxide, alumina, and silica. These inorganic oxides are preferably semiconductive (for example, a resistivity of 10 ⁸ Ω / □ or less).
Organic compounds as charge control agents include resin particles, quaternary ammonium salts (eg cetylpyridyl chloride, P-51, P-53 (manufactured by Orient Chemical Industries)), organic borates, imide compounds, imidazole compounds, Bisphenol compounds, urea compounds, onium salts and the like can be mentioned.
As the charge control agent, organic metal complexes include imidazole metal complexes, azo metal complex compounds (for example, S-44, S-34 (manufactured by Orient Chemical Industries), etc.), benzoic acid metal complexes, salicylic acid metal complexes (for example, E -84 (manufactured by Orient Chemical Co., Ltd.)), catechol metal complexes and the like.

Furthermore, as the charge control agent, dyes composed of complexes (for example, complexes of quaternary ammonium salts, nigrosine compounds, aluminum, iron, chromium, etc.), triphenylmethane pigments, resin types containing polar groups, etc. Can be mentioned.
These charge control agents are preferably, for example, particles having a spherical equivalent particle diameter of 200 μm or less.

Specific examples of the charge control agent include the following compounds. R ^{1 to} R ⁴ each represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, which may be the same as or different from each other.

  The content of the charge control agent is, for example, 0.1% by mass to 30% by mass with respect to the hydrophobic organic resin.

  Next, the hydrophilic organic resin particles and the hydrophobic organic resin will be collectively referred to as an organic resin, and common characteristics will be described below.

  The organic resin may have a straight chain structure, but is preferably a branched structure. The organic resin is preferably non-crosslinked or low-crosslinked from the viewpoint of image fixability. The organic resin may be a linear random copolymer or block copolymer, but a branched polymer (including branched random copolymer, block copolymer, and graft copolymer) is further included. It can be used suitably. For example, in the case of polyester synthesized by polycondensation, end groups can be increased by a branched structure. This branched structure is generally obtained 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. It is obtained by.

The organic 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 control of conductivity is conductivity such as tin oxide and titanium oxide (here, conductivity means, for example, a volume resistivity of less than 10 ⁷ Ω · cm. The same applies hereinafter unless otherwise specified). Addition of an inorganic substance that is conductive (here, semi-conductive means, for example, a volume resistivity of 10 ⁷ Ωcm or more and 10 ¹³ Ωcm or less. The same applies unless otherwise specified) is effective.

  The organic resin is desirably an amorphous resin from the viewpoint that it can be fixed at low temperature when ink is absorbed, and its glass transition temperature (Tg) is, for example, 30 ° C. or higher and 150 ° C. or lower.

  The glass transition temperature (and melting point) is 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 is used, an empty pan is set as a control, and the measurement is performed at a heating rate of 10 ° C./min.

  Examples of the weight average molecular weight of the organic resin include a range of 3000 to 100,000.

  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) is used as the eluent. As experimental conditions, a sample concentration of 0.5%, a flow rate of 0.6 ml / min, a sample injection amount of 10 μL, a measurement temperature of 40 ° C., and an IR detector are used. 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 ”.

  As for the acid value of organic resin, 50 mgKOH / g or more and 777 mgKOH / g or less are mentioned, for example in conversion of a carboxylic acid group (-COOH). The acid value in terms of this carboxylic acid group (—COOH) is a value measured by the following method.

  The acid value is measured in accordance with JIS K0070 and measured 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 is titrated with a 0.1 mol / L potassium hydroxide ethanol solution, and the end point is when the red color of the indicator lasts 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 ratio of the hydrophobic organic resin to the hydrophilic organic resin in the ink receiving particles is hydrophobic organic resin: hydrophilic organic resin = 1: 100 or more and 100: 100 or less by mass ratio.

The content ratio of the hydrophilic organic resin 101 and the hydrophobic organic resin 102 in the ink receiving particles 100 in the form of primary particles as exemplified in FIG. 1 is determined as follows.
It can be obtained by observing with a transmission electron microscope as in the particle diameter measuring method described above and analyzing the image.

Further, the content ratio of the hydrophilic organic resin particles 111 and the hydrophobic organic resin particles 112 in the ink receiving particles 110 in the form of composite particles as exemplified in FIG. 2 is obtained as follows.
It can be obtained by observing with a transmission electron microscope as in the particle diameter measuring method described above and analyzing the image.

(Block copolymer)
The block copolymer has a structural unit derived from a polar monomer and a structural unit derived from a nonpolar monomer. Furthermore, the solubility parameter (SP value) of the polar monomer in the block copolymer has an absolute value of 2 or less of the difference from the solubility parameter (SP value) of the polar monomer of the hydrophilic organic resin. By making the difference between the polar monomer of the block copolymer and the polar monomer of the hydrophilic organic resin an absolute value of 2 or less in the solubility parameter (SP value), the hydrophilic portion of the block copolymer However, it becomes easy to become familiar with the hydrophilic organic resin.

  In particular, it is desirable that the polar monomer of the block copolymer and the polar monomer of the hydrophilic organic resin have the same chemical structure from the viewpoint of bonding the hydrophilic organic resin and the hydrophobic organic resin. Note that “the chemical structure with the same polar monomer” means, for example, when acrylic acid is used as the polar monomer of the hydrophilic organic resin, acrylic acid is used as the polar monomer of the block copolymer. It means to use.

  Therefore, as the polar monomer in the block copolymer, it is preferable to use the polar monomer described for the hydrophilic organic resin, and among them, acrylic acid, methacrylic acid, (anhydrous) maleic acid, vinyl alcohol And polar monomers such as vinylpyrrolidone are preferred.

  Examples of the nonpolar monomer (hydrophobic monomer) of the block copolymer include the hydrophobic monomers described for the hydrophobic organic resin. Among these, hydrophobic monomers such as styrene, vinyl toluene, ethyl methacrylate, butyl methacrylate, ethyl acrylate, and butyl acrylate are preferable.

The block copolymer in this embodiment includes a graft copolymer.
In the case of a graft copolymer, the main chain may be a nonpolar monomer and the side chain may be a polar monomer, or the main chain may be a polar monomer and the side chain may be a nonpolar monomer.
Further, in the case of a so-called block copolymer, even if the block copolymer is a block copolymer in which one block of the hydrophobic site A and one block of the hydrophilic site B are bonded to each other, the block of the hydrophobic site A and the hydrophilic site B A block copolymer in which these blocks are bonded to each other may be used. From the viewpoint of ease of production, the former block copolymer is preferred.

  The ratio of the polar monomer to the nonpolar monomer in the block copolymer is preferably adjusted according to the hydrophilic organic resin particles and / or the hydrophobic organic resin particles, and the ratio cannot be generally described.

Here, the content ratio of the block copolymer in the entire ink receiving particles is 0.1% by mass or more and 10% by mass or less from the viewpoint of improving the ink receiving speed and suppressing the decrease in chargeability after time.
The content ratio of the block copolymer in the ink receiving particles can be determined as follows.
Dissolve the ink-receptive particles and sort by molecular weight using GPC. For each fraction, the structure is identified and the amount of block polymer is determined.

  The block copolymer can be produced by a known method for synthesizing a block copolymer (including a graft copolymer).

(Inorganic particles)
The ink receptive particles of the present embodiment can adhere inorganic particles to the surface of the mother particles regardless of whether the mother particles are in the form of primary particles or composite particles. In addition, inorganic particles can be contained in the primary particles, or inorganic particles can be contained as one particle of the composite particles.

  As the inorganic particles, both 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 resin particles.

(Other additives)
The ink receiving particles of the present embodiment desirably 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 the organic 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 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 these compounds And derivatives thereof.

  The organic amine compound may be any of primary, secondary, tertiary and quaternary amines and salts thereof.

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. Further, the content of the flocculant is, for example, 0.01% by mass or more and 30% by mass or less (preferably 0.1% by mass or more and 15% by mass or less, more preferably 1% by mass or more and 15% by mass or less. ) Range.

  The ink receiving particles of this embodiment desirably contain a release agent. The release agent may be included in the organic resin, or the release agent particles may be combined with the organic resin particles.

  Examples of the 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.

The ink receptive particles of the present embodiment described above can be used alone or in combination with a carrier. In particular, the ink receiving particles of the present embodiment are useful when used in combination with a carrier because the missing portions of the ink receiving particles are suppressed even when subjected to a physical impact from the carrier.
As the carrier, for example, a carrier used for a developer of an electrophotographic toner can be applied.

<Ink recording material>
The ink recording material of the present embodiment includes at least an ink containing a recording material and the ink receiving particles of the present embodiment.

Hereinafter, the ink will be described in detail.
The ink can be used for both water-based ink and oil-based ink, but water-based ink is used from the viewpoint of environment. 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 embodiment.

  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.

  Here, when a pigment is used as the coloring 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. However, in general, the total amount is 0.1% by mass or more and 100% by mass or less based on the pigment.

  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.

  Examples of the pigment that can be self-dispersed in water include a pigment obtained by subjecting the pigment to a surface modification treatment, as well as Cab-o-jet-200, Cab-o-jet-300, and Cab- Commercially available self-dispersing pigments such as o-jet-250, Cab-o-jet-260, Cab-o-jet-270, 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 a commercially available microcapsule pigment made by Dainippon Ink Chemical Co., Ltd., Toyo Ink, etc., but also a microcapsule pigment or the like produced for this embodiment. You can also.

  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 can be, 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.

  One or more water-soluble organic solvents 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.

  These surfactants may be used alone or in combination. In addition, 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 or more and 5% by mass or less.

  In addition, the ink has other properties such as penetrants for adjusting penetrability, polyethyleneimine, polyamines, polyvinyl pyrrolidone, polyethylene glycol, ethylcellulose, carboxymethylcellulose, etc. 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.) is 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, 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.

<Ink receiving particle storage cartridge>
The ink receptive particle storage cartridge according to the present embodiment is detachable from the recording apparatus. The ink receptive particle storage cartridge accommodates the ink receptive particles according to the present embodiment, and the ink receptive particle storage apparatus (particle supply apparatus) of the recording apparatus. It is a member for supplying particles.

  Hereinafter, the ink receptive particle storage cartridge of this embodiment will be described with reference to the drawings. FIG. 3 is a perspective view showing a cartridge for storing ink receiving particles according to the present embodiment. 4 is a cross-sectional view taken along line AA in FIG.

  As shown in FIGS. 3 and 4, the ink-receptive particle storage cartridge 50 according to the present embodiment includes a cylindrical particle storage cartridge main body 51 and side wall portions 52 and 54 fitted to both ends of the particle storage cartridge main body 51. It consists of and.

  Further, on the peripheral surface of the particle storage cartridge main body 51 on one end side, a carry-out port 60 is provided for carrying out the ink receiving particles toward a particle coating device (particle supply device: not shown) of the recording apparatus. A band 56 is slidably attached to the particle storage cartridge main body 51. The band portion 56 is provided with a storage portion 58 for storing the carry-out port 60 outside the carry-out port 60.

  Accordingly, when the particle storage cartridge 50 is not attached to the recording apparatus (or just after attachment), the carry-out port 60 is stored in the storage unit 58, and the ink receiving particles in the particle storage cartridge main body 51 are removed from the carry-out port 60. Does not leak.

  Further, a hole 62 is formed in the central portion of the side wall portion 54 on the other end side of the particle storage cartridge main body 51, and the coupling portion 66 of the coupling portion 64 is connected to the particle storage cartridge main body from the hole 62 of the side wall portion 54. 51 penetrates inside. Thereby, the coupling part 64 is rotatable with respect to the side wall part 54.

  An agitator 68 is disposed inside the particle storage cartridge main body 51. The agitator 68 is made of a metal linear member having a circular cross section, for example, stainless steel (SUS304WP), and is formed in a spiral shape. One end of one agitator is bent toward the rotation axis (rotation center) and is connected to the connection portion 66 of the coupling portion 64. The tip of the other end is a free end that is not constrained.

  The agitator 68 is rotated by applying a rotational force from the coupling portion 66 of the coupling portion 64, and moves toward the outlet 60 while stirring the ink receiving particles or the ink receiving particles and the carrier in the particle storage cartridge main body 51. Transport. In this way, the particles are discharged from the outlet 60, and the ink receiving particles are additionally supplied to the recording apparatus.

  The ink receiving particle storage cartridge of the present embodiment is not limited to the above configuration.

<Recording device>
The recording apparatus (recording method) of the present embodiment is a recording apparatus (recording method) using ink containing a recording material and the ink receiving particles of the present embodiment.
As one aspect of the recording apparatus (recording method) of the present embodiment, an intermediate transfer member, a supply device (supplying step) for supplying ink receiving particles onto the intermediate transfer member, and ink supplied on the intermediate transfer member Ink discharge device for discharging ink onto receptive particles (ink discharge step), transfer device for transferring ink receptive particles to a recording medium (transfer step), and fixing for fixing ink receptive particles transferred to the recording medium The ink receiving particles are a recording device (recording method) that receives the ink discharged from the ink discharge device on the intermediate transfer member.

  Specifically, for example, first, the ink receiving particles are supplied to the intermediate body (intermediate transfer body) in a layer form by the supply device. The ink receiving particles (hereinafter referred to as ink receiving particle layer) supplied in layers are discharged and received by an ink discharge device. The ink receiving particle layer that has received the ink is transferred from the intermediate to the recording medium by a transfer device. This transfer is selectively performed on the entire ink receptive particle layer or on the recording portion (ink receiving portion). Thereafter, the ink receiving particle layer transferred to the recording medium is pressed (or heated / pressed) by a fixing device to be fixed. In this way, recording is performed with the ink receiving particles that have received the ink. Note that the transfer and fixing may be performed substantially simultaneously or separately.

  Here, the ink receiving particles are formed in, for example, a layer when receiving ink, and the thickness of the ink receiving particle layer is, for example, 1 μm to 100 μm, preferably 3 μm to 60 μm, more preferably The range of 5 micrometers or more and 30 micrometers or less is mentioned. Further, the porosity in the ink receiving particle layer (that is, the void ratio between the ink receiving particles + the void ratio in the ink receiving particles (trap structure)) is, for example, 10% to 80%, preferably 30% to 70%. Hereinafter, the range of 40% or more and 60% or less is more preferable.

  Further, a release agent may be applied to the surface of the intermediate in advance before supplying the ink receiving particles. Examples of the mold release agent include (modified) silicone oil, fluorine oil, hydrocarbon oil, mineral oil, vegetable oil, polyalkylene glycol, alkylene glycol ether, alkane diol, and molten wax.

  As the recording medium, any of a penetrating medium (for example, plain paper or coated paper) or a non-penetrating medium (for example, art paper or resin film) can be applied. The recording medium is not limited to these, and includes industrial products such as semiconductor substrates.

  On the other hand, as other aspects of the recording apparatus (recording method) of the present embodiment, a supply device for supplying the ink receiving particles of the present embodiment onto a recording medium, and an ink receiving particle supplied on the recording medium are used. An ink discharge device that discharges ink and a fixing device that fixes the ink receptive particles supplied onto the recording medium. The ink receptive particles cause the ink discharged from the ink discharge device to flow on the recording medium. It may be a receiving recording device (recording method).

  Specifically, first, the ink receiving particles are supplied in a layer form to the recording medium by the supply device. The ink receiving particles (hereinafter referred to as ink receiving particle layer) supplied in layers are discharged and received by an ink discharge device. The ink receiving particle layer that has received the ink is pressed (or heated / pressed) by a fixing device to be fixed. In this way, recording is performed with the ink receiving particles that have received the ink. In this way, the recording medium may be supplied directly onto the recording medium.

  Hereinafter, the recording apparatus of the present embodiment will be described 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.

  FIG. 5 is a configuration diagram showing the recording apparatus of the present embodiment. FIG. 6 is a configuration diagram showing the main part of the recording apparatus of the present embodiment. FIG. 7 is a configuration diagram showing the ink receiving particle layer according to the present embodiment. In the following embodiment, a case will be described in which composite particles are applied as ink receiving particles to be described later, and a mixture of the composite particles and a conductive magnetic carrier is used.

  As shown in FIGS. 5 and 6, the recording apparatus 10 of the present 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 the charge on the intermediate transfer body 12. A particle supply device 18 for supplying ink-receptive particles 16 to the areas formed to form a particle layer; an ink jet recording head 20 for discharging ink droplets onto the particle layer to form an image; and a recording medium 8 superimposed on the intermediate transfer body 12. And a transfer fixing device 22 that transfers and fixes the ink receiving particle layer on the recording medium 8 by applying pressure and heat. An ink receiving particle storage cartridge 19 is detachably connected to the particle supply device 18 via a supply pipe 19A.

  On the upstream side of the charging device 28, a release agent supply device 14 that supplies the release agent 14D to form the release layer 14A is disposed.

  The surface of the intermediate transfer body 12 having a charge formed on the surface by the charging device 28 is formed with the ink receiving particles 16 as a layer by the particle supply device 18, and the ink jet recording head 20 for each color, that is, 20K, 20C, is formed on the particle layer. , 20M, and 20Y, ink droplets of each color are ejected to form a color image.

  The particle layer having the color image formed on the surface is transferred to the recording medium 8 together with the color image by a transfer fixing device (transfer fixing roll) 22. Downstream of the transfer fixing device 22, the ink receiving particles 16 remaining on the surface of the intermediate transfer body 12 are removed, and the intermediate transfer body adhering material such as foreign matters other than the particles (such as paper dust of the recording medium 8) is removed. A cleaning device 24 is provided.

  The recording medium 8 to which the color image has been transferred is carried out as it is, and the intermediate transfer body 12 is again charged on the surface by the charging device 28. At this time, the ink receiving particles transferred to the recording medium 8 absorb and hold the ink droplets 20A, so that they can be quickly carried out.

  Further, if necessary, the intermediate transfer body 12 is provided between the cleaning device 24 and the release agent supply device 14 (hereinafter, the term “between A and B” means “not including any unless otherwise specified”). You may arrange | position the static elimination apparatus 29 for removing the electric charge which remains on the surface.

In the present embodiment, the intermediate transfer body 12 has a 400 μm thick ethylene propylene rubber (EPDM) surface layer formed on a 1 mm thick polyimide film base layer. 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 body 12 is rotated, and a release layer 14A is first formed on the surface of the intermediate transfer body 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. .

  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.

  Next, by applying a charge to the surface of the intermediate transfer member 12 by the charging device 28, a positive charge is charged on the surface of the intermediate transfer member 12. Here, the ink receiving particles 16 can be supplied / adsorbed to the surface of the intermediate transfer body 12 by electrostatic force generated by an electric field that can be formed between the ink receiving particles 16 injected with electrostatic induction and the surface of the intermediate transfer body 12. A 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

The charging device 28 forms an elastic layer (foamed urethane resin) in which a conductivity imparting material is dispersed on a rod-like outer peripheral surface made of stainless steel, and has a volume resistivity of 10 ⁶ Ω · cm to 10 ⁸ Ω · cm. A roll-shaped member adjusted to a degree 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 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.

  Further, the charging device 28 may be composed of a corotron, a scorotron, or the like.

  Next, the ink supply particles 16 are supplied to the surface of the intermediate transfer body 12 by the particle supply device 18 to form the ink reception particle layer 16A. In the particle supply device 18, a mag roll 18 </ b> A is disposed on a portion of the container in which the ink receiving particles 16 are accommodated, facing the intermediate transfer body 12, and a regulating member 18 </ b> B is disposed so as to press the mag roll 18 </ b> A. The regulating member 18B has a function of regulating the layer thickness of the ink receiving particles 16 supplied to the surface of the mag roll 18A. The mag roll 18A can be a solid aluminum roll, and the regulating member 18B can be a metal plate (such as SUS) on which urethane rubber is caught to apply pressure. The regulating member 18B contacts the mag roll 18A by a doctor blade method.

  The ink-receptive particles 16 are regulated by the regulating member 18B (conductive blade) with the rotation of the mag roll 18A (conductive roll) together with the carrier 17, and then the charged intermediate transfer body 12 is charged. Faced to the surface. When the ink receiving particles 16 are opposed to the charged intermediate transfer member, charges having a polarity opposite to the charging polarity of the intermediate transfer member are injected through the mag roll 18A and the carrier 17 and charged. When the electrostatic force (electrostatic attractive force) acting between the ink receiving particles 16 and the intermediate transfer body 12 exceeds the adhesive force between the ink receiving particles 16 and the carrier 17, the ink receiving particles 16 The electrostatic force moves (flys) to the surface of the intermediate transfer body 12. In this way, the ink receiving particles 16 are supplied onto the intermediate transfer body 12.

  At this time, the moving speed of the intermediate transfer body 12 and the rotational speed of the mag roll 18A are relatively set so as to form one particle layer 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 mag 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 mag roll 18A on the basis of the peripheral speed ratio for forming the one ink receptive particle layer 16A. be able to. 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 (the ink shot amount is large (for example, 4 g / m ² or more and 15 g / m ² or less)), the ink liquid component (solvent or dispersion medium) can be held sufficiently. It is desirable to control the layer thickness (for example, 10 μm or more and 25 μm or less).

  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 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.

  For example, when it is desired to provide the particle layer 16C as the protective layer on the image layer 16B as the final image, the ink receiving particle layer 16A has a thickness of about three layers, and the uppermost layer is imaged with ink. For example (see FIG. 7A), the two particle layers 16C not subjected to image formation are formed on the image layer 16B as a protective layer after the transfer and fixing (see FIG. 7B).

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

  Next, the ink jet recording head 20 applies ink droplets 20A to the ink receiving particle layer 16A. The ink jet recording head 20 applies ink droplets 20A to predetermined positions based on predetermined image information.

  Finally, the recording medium 8 and the intermediate transfer body 12 are sandwiched by the transfer fixing device 22, and pressure and heat are applied to the ink receiving particle layer 16A, whereby the ink receiving particle layer 16A is transferred onto the recording medium 8. .

  The transfer fixing device 22 includes a heating roll 22A containing a 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. As 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 can be used.

  Since the ink receiving particle layer 16A is heated by the heater and pressure is applied at the contact portion between the heating roll 22A and the pressure roll 22B, the ink receiving particle layer 16A is transferred and fixed to the recording medium 8.

  At this time, the organic resin particles constituting the ink receptive particles 16 in the non-image area were softened (or melted) by being heated to the glass transition temperature Tg) or higher, and formed on the surface of the intermediate transfer body 12 by pressure. The ink receiving particle layer 16 </ b> A is released from the release layer 14 </ b> A, and is transferred and fixed onto the recording medium 8. Then, the ink receiving particle layer 16 </ b> A is released from the release layer 14 </ b> A formed on the surface of the intermediate transfer body 12 by pressure, and is transferred onto the recording medium 8. At this time, the transfer fixing property is improved by heating. In this embodiment, the surface of the heating roll 22A is controlled at 160 ° C. At this time, the ink liquid component (solvent or dispersion medium) held in the ink receiving particle layer 16A is held and fixed in the ink receiving particle layer 16A as it is after the transfer. Further, the intermediate transfer body 12 may be preheated before the transfer fixing device 22.

  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 industrial products such as semiconductor substrates.

  Hereinafter, the image forming process of the recording apparatus according to the embodiment will be described in more detail. In the recording apparatus of this embodiment, as shown in FIG. 6, a release layer 14 </ b> A can be formed on the surface of the intermediate transfer body 12 by a release agent supply device 14. If the material of the intermediate transfer body 12 is aluminum or PET base, it is particularly desirable to form the release layer 14A. Alternatively, a fluororesin / silicone rubber-based material may be used so that the surface of the intermediate transfer body 12 has releasability.

  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. As a result, the ink receiving particles 16 charged and injected through the mag roll 18A and the carrier 17 of the particle supply device 18 are electrostatically adsorbed, and a layer of the ink receiving particles 16 is formed on the surface of the intermediate transfer body 12. can do.

  Next, the ink receiving particles 16 are formed as a layer on the surface of the intermediate transfer body 12 by the mag roll 18A of the particle supply device 18. For example, the formed ink receiving particle layer 16A is formed to have a thickness in which the ink receiving particles 16 are overlapped by about three layers. That is, the thickness of the ink receptive particle layer 16A transferred to the recording medium 8 is controlled by controlling the ink receptive particle layer 16A to a desired thickness by the gap between the regulating member 18B and the mag roll 18A as described above. . Alternatively, it may be controlled by the peripheral speed ratio between the mag roll 18A and the intermediate transfer body 12.

  Next, ink droplets 20A are ejected onto the formed ink receptive particle layer 16A by an ink jet recording head 20 of each color driven by a piezoelectric (piezo) or thermal method, and an image is formed on the ink receptive particle layer 16A. Layer 16B is formed. The ink droplets 20A 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 constituting the ink receiving particles 16. At the same time, 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 constituting the ink receiving particles 16.

  At this time, the ink liquid component (solvent or dispersion medium) contained in the ink droplet 20A permeates the ink receptive particle layer 16A, but the recording material such as a pigment is captured on the surface of the ink receptive particle layer 16A or the interparticle gap. The That is, the ink liquid component (solvent or dispersion medium) may penetrate to the back surface of the ink receiving particle layer 16A, but the recording material such as a pigment does not penetrate the back surface of the ink receiving particle layer 16A. Thereby, when the recording material 8 is transferred to the recording medium 8, the particle layer 16C into which the recording material such as the pigment does not penetrate forms a layer on the image layer 16B, so that the particle layer 16C encloses the surface of the image layer 16B. It becomes a protective layer, and an image in which a recording material (for example, a color material such as a pigment) is not exposed on the surface can be formed.

  Next, a color image is formed on the recording medium 8 by transferring / fixing the ink receiving particle layer 16A on which the image layer 16B is formed from the intermediate transfer body 12 onto the recording medium 8. The ink receiving particle layer 16 </ b> A on the intermediate transfer body 12 is heated and pressed by a transfer fixing device (transfer fixing roll) 22 heated by a heating means such as a heater and transferred onto the recording medium 8.

  At this time, the glossiness may be controlled by adjusting the unevenness of the image surface by adjusting heating and pressurization as described later. Further, the glossiness may be controlled by performing cooling peeling.

  Residual particles 16D remaining on the surface of the intermediate transfer member 12 after the ink-receptive particle layer 16A is peeled off are collected by the cleaning device 24 (see FIG. 5), and the surface of the intermediate transfer member 12 is charged again by the charging device 28. Then, the ink receiving particles 16 are supplied to form the ink receiving particle layer 16A.

  Here, FIG. 7 shows a particle layer used for image formation according to the embodiment. As shown in FIG. 7A, a release layer 14 A is formed on the surface of the intermediate transfer body 12.

  Next, the ink receiving particles 16 are formed as a layer on the surface of the intermediate transfer body 12 by the particle supply device 18. The ink receptive particle layer 16A formed as described above preferably has a thickness in which the ink receptive particles 16 are overlapped by about three layers. The thickness of the ink receiving particle layer 16A transferred to the recording medium 8 is controlled by controlling the ink receiving particle layer 16A to a desired thickness. At this time, the surface of the ink receiving particle layer 16A is leveled so as not to hinder the image formation (formation of the image layer 16B) by the ejection of the ink droplet 20A.

  Further, the recording material such as pigment contained in the ejected ink droplet 20A penetrates to about 1/3 or more and half or less of the ink receiving particle layer 16A as shown in FIG. A particle layer 16C that does not penetrate the recording material remains.

  The ink receiving particle layer 16A formed on the recording medium 8 by heating and pressure transfer by the transfer fixing device (transfer fixing roll) 22 is a particle layer containing no ink on the image layer 16B as shown in FIG. 7B. Since 16C exists, the image layer 16B does not appear directly on the surface and functions as a kind of protective layer. For this reason, at least the ink receiving particles 16 after fixing must be transparent.

  Since the particle layer 16C is heated and pressed by the transfer fixing device (transfer fixing roll) 22, the surface can be flattened, and the glossiness of the image surface can be controlled by heating and pressing.

  Further, drying of the ink liquid component (solvent or dispersion medium) trapped inside the ink receiving particles 16 by heating may be promoted.

  The ink liquid component (solvent or dispersion medium) received / held in the ink receiving particle layer 16A is held in the ink receiving particle layer 16A even after transfer fixing, and is removed by natural drying.

  Through the above steps, image formation is completed. With respect to the intermediate transfer body 12, there are foreign particles 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 released from the recording medium 8. May be removed by the cleaning device 24.

  Further, a static elimination device 29 may be arranged downstream of the cleaning device 24. 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. .

Various other device conditions such as the above-mentioned charging voltage, particle layer thickness, fixing temperature, etc. are optimized because the optimum conditions are determined by the ink receiving particles 16 or ink composition, ink discharge amount, etc. To do.
Next, components of each step of the embodiment will be described in detail.

(Intermediate transfer member)
The intermediate transfer body 12 on which the ink receptive particle layer is formed may be a belt shape or a cylindrical shape (drum shape) as in the embodiment. In order to supply and hold the ink receiving particles on the surface of the intermediate transfer member by electrostatic force, the outer peripheral surface of the intermediate transfer member needs to have a semiconductive or insulating particle holding property. As 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 ⁷ Ω · m or more and 10 ¹¹ Ω · m or less, In the case of insulation, a member having a surface resistivity of 10 ¹⁴ Ω / □ or more and a volume resistivity of 10 ¹¹ Ω · m or more is used.

  In the case of a belt shape, the substrate can be driven by a belt in the device, has the necessary mechanical strength, and has the necessary heat resistance, especially when heat is used during transfer / fixing. I just need it. Specifically, polyimide, polyamideimide, aramid resin, polyethylene terephthalate, polyester, polyethersulfone, stainless steel and the like are used.

  In the case of a drum shape, aluminum, stainless steel, etc. can be considered as the base material.

  In order to exhibit the heating method by electromagnetic induction in the fixing process in the transfer fixing device (transfer fixing roll) 22, a heat generating layer may be formed on the intermediate transfer body 12 instead of the transfer fixing device (transfer fixing roll) 22. Good. 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.

(Particle supply process)
First, the release agent supply device 14 forms a release layer 14A of the release agent 14D on the surface of the intermediate transfer body 12 before the ink receiving particles 16 are supplied.

  The method for supplying the release layer 14A includes a release agent 14D, a release agent 14D supplied to the release agent supply member, and the release member 14D supplied to the surface of the intermediate transfer body 12 by the supply member. A method of forming the layer 14A, a method of forming the release layer 14A on the surface of the intermediate transfer body 12 by a supply member impregnated with the release agent 14D, and the like are used.

  Examples of the release agent 14D 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 14D is, for example, 5 mPa · s or more and 200 mPa · s or less.

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 14D is, for example, 40 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 14D is, for example, in the range of 250 ° 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.

  Next, the charging device 28 charges the surface of the intermediate transfer body 12 to a polarity opposite to that of the ink receiving particles 16. Then, an ink receptive particle layer 16 </ b> A is formed on the surface of the charged 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 charged with a polarity opposite to the charge on the surface of the intermediate transfer body 12 by electrostatic induction.

  The ink receiving particles 16 held by the mag roll 18A form an electric field with the surface of the intermediate transfer body 12, and are moved / supplied and held on the intermediate transfer body 12 by electrostatic force. At this time, the thickness of the ink receptive particle layer 16A may be controlled by the thickness of the image layer 16B formed on the ink receptive particle layer 16A (in accordance with the amount of ink to be applied). At this time, the absolute value of the charge amount of the ink receiving particles 16 is desirably in the range of 5 μc / g to 50 μc / g.

  Here, the thickness of the ink receiving particle layer 16A is 1 μm or more and 100 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 10% or more and 80% or less.

  Hereinafter, the layer thickness control of the ink receiving particle layer will be described.

  The ink receiving particles 16 are supplied to the mag roll 18A, and the thickness of the particle layer is regulated by the regulating member 18B.

  The regulating member 18B has a function of regulating the layer thickness of the ink receiving particles 16 on the surface of the mag roll 18A. For example, the pressure applied to the mag roll 18A is changed to change the layer thickness of the ink receiving particles 16 on the surface of the mag roll 18A. . For example, the thickness of the ink receiving particles 16 on the surface of the mag roll 18A is, for example, one layer, and the thickness of the ink receiving particles 16 formed on the surface of the intermediate transfer body 12 is approximately one layer. Further, the pressing force of the regulating member 18B is controlled to be low, the thickness of the ink receiving particles 16 formed on the surface of the mag roll 18A is increased, and the thickness of the ink receiving particles formed on the surface of the intermediate transfer member 12 is increased. You may let them.

  As another method, for example, when the peripheral speed of the mag roll 18A for forming one particle layer on the surface of the intermediate transfer body 12 and the intermediate transfer body 12 is set to 1, the peripheral speed of the mag roll 18A is increased and the intermediate transfer body 12 is increased. It can be controlled to increase the number of ink receptive particles 16 supplied above and to increase the thickness of the ink receptive particle layer on the intermediate transfer body 12. It is also possible to control by combining the above methods. In the above configuration, for example, the ink receiving particles 16 are negatively charged, and the surface of the intermediate transfer body 12 is positively charged.

  By controlling the layer thickness of the ink receiving particle layer in this way, it is possible to form a pattern whose surface is covered with a protective layer while suppressing consumption of the ink receiving particle layer.

As a charging roll in the charging device 28, an elastic layer in which a conductivity imparting material is dispersed is formed on the outer peripheral surface of a rod-like or pipe-like member made of aluminum, stainless steel, or the like, and a volume resistivity of 10 ⁴ Ω · m or more 10 A roll having a diameter of 10 mm to 25 mm adjusted to about ⁶ Ω · m or less can be used.

  The 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, or polynorbornene rubber. A preferred material used in the above mixture 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.

  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 the intermediate transfer body 12 is sandwiched between the charging roll 31 and a predetermined potential difference is generated between the charging apparatus 28 and the grounded driven roll 31 at the pressing position.

(Marking process)
Based on the image signal, ink droplets 20A are ejected from the ink jet recording head 20 to the layer of ink receptive particles 16 (ink receptive particle layer 16A) formed on the surface of the intermediate transfer body 12, thereby forming an image. The ink droplets 20A ejected from the ink jet recording head 20 are driven into the ink receiving particle layer 16A, and the ink droplets 20A are quickly absorbed by the gaps between the particles formed in the ink receiving particles 16, and the recording material ( For example, the pigment) is trapped (trapped) on the surface of the ink receiving particles 16 or in the voids between the particles constituting the ink receiving particles 16.

  In this case, it is desirable to capture (trap) many recording materials (for example, pigments) on the surface of the ink receiving particle layer 16A. The voids between the particles in the ink receiving particles 16 exert a filter effect, trap the recording material (for example, pigment) on the surface of the ink receiving particle layer 16A, and the voids between the particles in the ink receiving particles 16. It is expressed by being trapped and fixed.

  In order to ensure that the recording material (for example, pigment) is trapped in the space between the surface of the ink receiving particle layer 16 </ b> A and the particles in the ink receiving particle 16, the ink and the ink receiving particle 16 are caused to react with each other. A method of rapidly insolubilizing (for example, pigment) (for example, 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 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.

  When the ink receiving particles 16 are reacted with the ink, the treatment is performed with an aqueous solution containing an aggregating agent (for example, a polyvalent metal salt or an organic acid) that gives the effect of aggregating the pigment by reacting the ink receiving particles 16 with the ink. Use and dry.

(Transfer process)
The ink receiving particle layer 16 </ b> A that receives the ink droplet 20 </ b> A and has an image formed thereon is transferred and fixed to the recording medium 8, thereby forming an image on the recording medium 8. The transfer and fixing may be performed by different processes, but it is desirable that the transfer and fixing be performed substantially simultaneously. Fixing includes either a method of heating or pressurizing the ink receptive particle layer 16A, or a method of using both heating and pressurization. Preferably, a method of performing heating / pressing substantially simultaneously is preferable.

  Further, by controlling the heating / pressurization, it is possible to control the surface physical properties of the ink receiving particle layer 16A and to control the gloss (glossiness). Further, when the recording medium 8 onto which the image (ink-receptive particle layer 16A) has been transferred after being heated / pressurized is peeled off from the intermediate transfer body 12, the ink-receptive particle layer 16A may be peeled off after being cooled. Good. The cooling method may be forced cooling such as natural cooling or air cooling. For these processes, the intermediate transfer member 12 preferably has a belt shape.

  The ink image is formed on the surface layer of the ink receiving particle 16 layer formed on the intermediate transfer body 12 (the recording material (pigment) is trapped on the surface of the ink receiving particle layer 16A) and transferred to the recording medium 8. By doing so, the ink image is preferably formed so as to be protected by the particle layer 16 </ b> C of the ink receiving particles 16.

  The ink liquid component (solvent or dispersion medium) received / held in the ink receiving particle 16 layer is held in the ink receiving particle 16 layer even after the transfer and fixing, and is removed by natural drying.

(Cleaning process)
In order to refresh the surface of the intermediate transfer body 12 to enable repeated use, a process of cleaning the surface with the cleaning device 24 is necessary. The cleaning device 24 includes a cleaning unit and a particle transport / recovery unit (not shown). By the above cleaning, the ink receiving particles 16 (residual particles 16D) remaining on the surface of the intermediate transfer body 12 are removed. The adhering matter adhering to the surface of the intermediate transfer body 12 such as the foreign matter (paper dust of the recording medium 8) is removed. The recovered residual particles 16D may be reused.

(Static removal process)
Before forming the release layer 14 </ b> A, the surface of the intermediate transfer body 12 may be neutralized using the neutralization device 29.

  In the recording apparatus according to the embodiment described above, after the release agent 14D is supplied to the surface of the intermediate transfer body 12 by the release agent supply apparatus 14 to form the release layer 14A, the surface of the intermediate transfer body is formed by the charging device 28. Charge. Next, the ink receiving particles 16 are supplied from the particle supply device 18 to the region where the release layer of the intermediate transfer body 12 is formed and charged, thereby forming a particle layer. Then, ink droplets are ejected onto the particle layer by the ink jet recording head 20 to form an image. As a result, ink is received by the ink receiving particles 16. Next, the recording medium 8 is overlapped with the intermediate transfer body 12, and pressure and heat are applied by the transfer fixing device 22 to transfer and fix the ink receiving particle layer on the recording medium 8.

  Note that the recording apparatus is not limited to the intermediate transfer type, and may be any other form in which the ink receiving particles described below are supplied directly onto the recording medium.

  FIG. 8 is a configuration diagram illustrating a recording apparatus according to another embodiment. FIG. 9 is a configuration diagram illustrating a main part of a recording apparatus according to another embodiment. In the following other embodiments, the case where composite particles are applied as ink receiving particles described later is described.

  As shown in FIGS. 8 and 9, the recording apparatus 11 according to another embodiment includes an endless belt-like conveyance belt 13. The conveyance belt 13 rotates and conveys the recording medium 8 sent from a storage container (not shown).

  First, an ion flow control electrostatic recording head 70 (hereinafter abbreviated as “electrostatic recording head 70”) controls a recording medium 8 being transported by the transport belt 13 to control the ion flow caused by the discharge. An electrostatic latent image is formed by irradiating on the surface 8. (See FIG. 10A).

  The electrostatic latent image formed on the recording medium 8 is visualized by the particle supply device 18 to form an ink receptive particle layer 16 </ b> A composed of the ink receptive particles 16. (See FIG. 10B).

  The preliminary fixing device 150 preheats and fixes the ink receiving particle layer 16 </ b> A formed on the recording medium 8.

  From the ink-receiving particle layer 16A that has been preheated and fixed, image data from the inkjet recording heads 20K, 20C, 20M, and 20Y for each color of black (K), cyan (C), magenta (M), and yellow (Y). The ink droplets 20A (see FIG. 9) for each color are ejected to form an ink image. (See FIG. 10C). Hereinafter, when it is necessary to distinguish each color, Y, M, C, and K are appended after the reference numerals, but Y, M, C, and K are omitted when it is not particularly necessary to distinguish each color.

  The ink receiving particle layer 16A on which the ink image is formed by the ejection of the ink droplet 20A is fixed on the recording medium 8 by the fixing device 23 applying pressure and heat.

  The electrostatic recording head 70 and the ink jet recording head 20 are so-called FWA (Full Width Array) type recording heads that are more than the width of the recording medium 8.

  Next, details of each component and the image forming process will be described.

  The recording medium 8 is transported by an endless belt-shaped transport belt 13. In the present embodiment, the recording medium 8 is conveyed while being adsorbed to the conveying belt 13.

  Here, as an example of a method for adsorbing the recording medium 8 to the conveyance belt 13, for example, a suction mechanism in which a hole (not shown) is provided in the conveyance belt 13 and sucked and adsorbed from the hole can be cited. In addition, the method of adsorbing the recording medium 8 to the conveyance belt 13 may be, for example, a method of adsorbing with the adhesive force, or a method of electrostatically adsorbing the recording medium 8 to the conveyance belt 13.

  An electrostatic recording head 70 that forms an electrostatic latent image on the recording medium 8 being transported to the transport belt 13 is disposed above the recording medium 8 with an interval on the upstream side in the transport direction. .

  In the electrostatic recording head 70, a plurality of drive electrodes 74 are provided in parallel with each other on the surface of a flat rectangular insulating substrate 72, and a plurality of controls are provided on the back surface thereof so as to intersect with these drive electrodes 74. An electrode 76 is provided. The drive electrode 74 and the control electrode 76 form a matrix (lattice). The control electrode 76 has a circular opening 76 </ b> A at a position intersecting with the drive electrode 74. A screen electrode 78 is provided on the lower surface of the control electrode 76 via an insulating substrate 71. In the insulating substrate 71 and the screen electrode 78, a space 81 and an ion extraction opening 80 are formed at a position corresponding to the opening 76A of the control electrode 76.

  A high frequency high voltage is applied between the drive electrode 74 and the screen electrode 78 by the AC power source 82. On the other hand, a pulse voltage corresponding to image information is applied to the control electrode 76 by an ion control power source 84. Further, a DC voltage is applied to the screen electrode 78 by a DC power source 86.

  Then, by applying an alternating electric field between the drive electrode 74 and the control electrode 76 thus insulated, a creeping corona discharge is induced in the space 81, and ions generated by the creeping corona discharge are caused to flow between the control electrode 76 and the control electrode 76. It is accelerated or absorbed by an electric field formed between the screen electrode 78 and the discharge of the ion flow from the ion outlet opening 80 is controlled, and ions corresponding to the image signal (ink image) (plus in this embodiment) The electrostatic latent image (see FIG. 10A) is formed on the surface of the recording medium 8 by ions.

  The potential of the electrostatic latent image is formed by the electrostatic latent image formed on the recording medium 8 and the ink receiving particles 16 charged by charge injection through the mag roll 18A and the carrier 17 of the particle supply device 18 in the next step. Any potential may be used as long as the ink receiving particles 16 can be supplied / adsorbed to the recording medium 8 by the electrostatic force generated by the applied electric field.

  The electrostatic recording head 70 can select a region where an electrostatic latent image is formed. Therefore, the electrostatic latent image formed on the surface of the recording medium 8 is a region where an ink image is formed. For example, when the formed image is the letter “A”, it is conceptually shown in FIG.

  The recording medium 8 on which the electrostatic latent image is formed is sent to the particle supply device 18 to visualize the electrostatic latent image and form an ink receiving particle layer 16A corresponding to the electrostatic latent image. (See FIG. 10B). Thus, the ink receptive particle layer 16A is formed on the recording medium 8 in the ink image region formed based on the image signal (the ink receptive particle layer 16A is hardly formed in the non-image portion region). .

  Next, the description returns to the image forming process.

  Next, as shown in FIG. 10A, the ink receiving particle layer 16 </ b> A formed on the recording medium 8 is preliminarily fixed by the preliminary fixing device 150.

  The ink receiving particle layer 16 </ b> A formed on the recording medium 8 is fixed on the recording medium 8 by electrostatic force. Therefore, if the ink droplet 20A is ejected from the inkjet recording head 20 into the ink receiving particle layer 16A in the next step as it is, the ink receiving particle layer 16A may be disturbed depending on the amount of ink. For this reason, the ink receiving particle layer 16A is preliminarily fixed in advance to temporarily fix the ink receiving particle 16 on the surface of the recording medium 8.

  In addition, the preliminary fixing prevents the ink receiving particles 16 from being scattered by the ink droplets 20 </ b> A being ejected and the nozzle surface 20 </ b> B of the inkjet recording head 20 from being contaminated.

  The preliminary heating in the preliminary fixing device 150 is at a lower temperature than the fixing heating in the final fixing device 23. That is, the preliminary fixing in the preliminary fixing device 150 does not completely melt the resin particles in the ink receiving particles 16 and fix them by pressure, but leaves gaps between the particles, and between the particles and between the particles and the recording medium. It is sufficient to bind the surface. As a result, the ink droplet 20A is preliminarily fixed to an acceptable level.

  The preliminary fixing device 150 can be a general heat fixing device (fuser) used in an electrophotographic image forming apparatus. Further, in addition to the heat fixing device used in the electrophotographic image forming apparatus, a heater heating method, an oven method, an electromagnetic induction heating method, or the like can be used.

  Next, the recording medium 8 on which the ink receptive particle layer 16A is preliminarily fixed is conveyed below the ink jet recording head 20.

  Then, based on the image data, ink droplets 20A are ejected from the ink jet recording head 20, and are ejected onto the ink receiving particle layer 16A formed on the surface of the recording medium 8, thereby forming an ink image. (FIG. 10C). At this time, the ink is received by the ink receiving particles 16.

  In order to write an image at a high speed, a line type ink jet recording head having a width equal to or larger than the width of the recording medium as in the present embodiment is desirable, but an image may be formed sequentially using a scan type ink jet recording head. 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 driving type and a heating element driving type.

  Next, the recording medium 8 is peeled off from the conveying belt 13 and sent to the fixing device 23, and pressure and heat are applied to the ink receiving particle layer 16 </ b> A, whereby the ink receiving particle layer 16 </ b> A is formed on the recording medium 8. To settle.

  The fixing device 23 includes a heating roll 23A containing a heating source and a pressure roll 23B facing the heating roll 23A. The heating roll 23A and the pressure roll 23B are in contact with each other to form a contact portion. As the heating roll 23A and the pressure roll 23B, for example, the outer surface of an aluminum core is coated with silicone rubber, and further coated with a PFA tube. The configuration is substantially the same as that of a fixing device (fuser) used in an electrophotographic image forming apparatus. Further, in addition to the heat fixing device used in the electrophotographic image forming apparatus, a heater heating method, an oven method, an electromagnetic induction heating method, or the like can be used.

  When the recording medium 8 passes through the contact portion between the heating roll 23A and the pressure roll 23B, the ink receiving particle layer 16A is heated and pressure is applied, and the ink receiving particle layer 16A is fixed to the recording medium 8. . Note that not only a method using both heating and pressurization but also a method using only heating or only pressurization may be used. However, it is desirable to perform heating and pressurization simultaneously.

  Through the above steps, image formation is completed, and the recording medium 8 is discharged out of the apparatus.

  In the recording apparatus 11 according to another embodiment described above, an electrostatic latent image is formed by the electrostatic recording head 70 while the recording medium 8 is conveyed by the conveyance belt 13, and the particle supply device 18 is applied to the electrostatic latent image. The ink receiving particles 16 are supplied to form a particle layer. Then, ink droplets are ejected onto the particle layer by the ink jet recording head 20 to form an image. As a result, ink is received by the ink receiving particles 16. Next, after the recording medium 8 is peeled from the conveying belt 13, the ink receiving particle layer is fixed on the recording medium 8 by applying pressure and heat by the fixing device 23. Except for what has been described above, the recording apparatus according to the above embodiment is the same as the recording apparatus according to the above embodiment, and thus description thereof is omitted.

  As described above, in the 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 embodiment is not limited to recording characters and images on a recording medium. In other words, the recording apparatus of the present embodiment can be applied to all industrially used droplet discharge (ejection) apparatuses.

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

-Production of block polymer A-
<Polymerization>
In a nitrogen gas atmosphere, the following materials were added to the reaction vessel and stirred while warming.
・ Toluene 200ml
・ Styrene 100mmol
・ 1.5 ml of n-butyllithium solution
At this time, the polymerization reaction was monitored by gas chromatography (GPC), and the heating was terminated when the desired molecular weight was reached.

  Next, after cooling, while monitoring the polymerization reaction by gas chromatography (GPC), 100 mmol of butyl acrylate was added and stirred, and heating was terminated when the desired molecular weight was reached.

<Stop reaction>
A methanol solution containing 5% by mass of 2,6-di-tert-butyl-p-cresol was added to stop the polymerization reaction.

<Removal of protecting group>
The obtained polymer was dissolved in toluene, an appropriate amount of toluenesulfonic acid was added, and the mixture was heated for 12 hours. Thereafter, the polymer was washed and dried to obtain a block polymer A of styrene-acrylic acid. The weight average molecular weight Mw of the block polymer A was 1500.

-Production of block polymers B-I-
Block polymers B to I were prepared in the same manner as the preparation of block polymer A, except that the raw materials shown in Table 1 below were used.

  In Table 1 above, “-” means not used as a raw material.

-Production of particles A-
-Styrene / n-butyl methacrylate / acrylic acid copolymer (polar monomer ratio 50 mol%) 100 parts by mass-Sodium hydroxide 10.2 parts by mass-Ion-exchanged water 1000 parts by mass While mixing the above materials and heating The mixture was stirred to prepare emulsion liquid-A1 for hydrophilic organic resin.

-Styrene / n-butyl methacrylate / acrylic acid copolymer (polar monomer ratio 4.5 mol%) 50 parts by mass-Block polymer A 5 parts by mass-Ion-exchanged water 500 parts by mass Vibration was applied to prepare an emulsion liquid-A2 for a hydrophobic organic resin.

  The two types of emulsion liquids -A1 and -A2 were mixed and stirred, and then granulated using a Spray-Dry machine (NL-5 / manufactured by Okawara Kako Co., Ltd.). Further, the particles were classified with an airflow classifier.

For 100 parts by mass of classified particles,
・ 0.5 parts by mass of amorphous silica (Aerosil A130 / Degussa) ・ 0.5 parts by mass of amorphous silica (Aerosil RX200 / Degussa) was mixed by stirring to prepare ink receiving particles A as composite particles. Obtained.

The sphere-converted average particle size of the ink receiving particles A was measured by a dry particle size distribution meter (Microtrac MT3200 / manufactured by Nikkiso Co., Ltd.) and found to be 8 μm.
The particle diameters of the hydrophilic organic resin particles and the hydrophobic organic resin particles in the ink receiving particles A were measured / analyzed using the transmission electron microscope described above. Was 0.2 μm and 0.05 μm, respectively, and the particle diameter ratio was 4: 1. The results are shown in Table 2 below.

-Production of particle B-
-Styrene / n-butyl methacrylate / methacrylic acid copolymer (polar monomer ratio 33 mol%) 100 parts by mass-Sodium hydroxide 9.3 parts by mass-Ion-exchanged water 1000 parts by mass While mixing the above materials and heating The mixture was stirred to prepare emulsion liquid-B1 for hydrophilic organic resin. Subsequently, water was removed with an evaporator to obtain a solid content B1.

-Styrene / n-butyl acrylate / n-butyl methacrylate / methacrylic acid copolymer (polar monomer ratio 0.5 mol%) 33 parts by mass-Block polymer B 12.5 parts by mass-Solid content B1 5 parts by mass Were mixed and stirred with a Henschel mixer to obtain a kneaded material. Subsequently, it was put into an extruder and melt kneaded. The obtained kneaded product was cooled and then pulverized using a jet mill. This was classified with an air classifier.

For 100 parts by mass of classified particles,
・ Amorphous silica (Aerosil A130 / Degussa) 0.25 parts by mass ・ Amorphous silica (Aerosil RX200 / Degussa) 0.75 parts by mass was stirred and mixed, and the ink receiving particles B as primary particles were mixed. Obtained.

The obtained ink receiving particles B had a sphere equivalent average particle size of 6 μm.
Further, the particle diameter of the hydrophobic organic resin in the ink receiving particles B was measured by the above-described measurement / analysis method using the transmission electron microscope and found to be 0.1 μm.

-Production of particles C-
Styrene / n-butyl methacrylate / maleic acid copolymer (polar monomer ratio 25 mol%) 100 parts by mass Styrene / n-butyl methacrylate / maleic acid copolymer (polar monomer ratio 2.5 mol%) 45 Part by mass, sodium hydroxide 7.0 parts by mass, block polymer C 2 parts by mass, ion-exchanged water 1500 parts by mass Ultrasonic vibration was applied to the mixture of the above materials to prepare an emulsion.

  The emulsion solution was stirred and then granulated using a Spray-Dry machine (NL-5 / Okawara Chemical Co., Ltd.). Further, the particles were classified with an airflow classifier.

For 100 parts by mass of classified particles,
・ 0.5 parts by mass of amorphous silica (Aerosil A130 / Degussa) ・ 0.5 parts by mass of amorphous silica (Aerosil RX200 / Degussa) was mixed by stirring to prepare ink receiving particles C as composite particles. Obtained.
The obtained ink receiving particles C had a sphere equivalent average particle size of 7 μm.
The particle diameters of the hydrophilic organic resin particles and the hydrophobic organic resin particles in the ink receiving particles C were 0.15 μm and 0.10 μm, respectively.

-Production of particles D-
-Styrene / 2-ethylhexyl acrylate / acrylic acid copolymer (polar monomer ratio 50 mol%) 100 parts by mass-Sodium hydroxide 12.2 parts by mass-Ion-exchanged water 1000 parts by mass While mixing the above materials and heating The mixture was stirred to prepare emulsion liquid-D1 for hydrophilic organic resin.

-Styrene / 2-ethylhexyl acrylate / acrylic acid copolymer (polar monomer ratio 7 mol%) 30 parts by mass-Block polymer D 3 parts by mass-Ion-exchanged water 300 parts by mass Ultrasonic vibration is applied to the liquid in which the above materials are mixed. And an emulsion liquid-D2 for hydrophobic organic resin was prepared.

  The two types of emulsion liquids -D1 and -D2 were mixed and stirred, and then granulated using a Spray-Dry machine (NL-5 / manufactured by Okawara Chemical Co., Ltd.). Further, the particles were classified with an airflow classifier.

For 100 parts by mass of classified particles,
・ Amorphous silica (Aerosil A130 / Degussa) 0.25 parts by mass Amorphous silica (Aerosil RX200 / Degussa) 0.75 parts by mass was mixed with stirring to prepare ink receiving particles D as composite particles. Obtained.

The average spherical particle diameter of the ink receiving particles D was 5 μm.
The particle diameters of the hydrophilic organic resin particles and the hydrophobic organic resin particles in the ink receiving particles D were 0.32 μm and 0.04 μm, respectively.

-Production of particle E-
-Styrene / n-butyl acrylate / methacrylic acid copolymer (polar monomer ratio 17.5 mol%) 100 parts by mass-Sodium hydroxide 5.8 parts by mass-Ion-exchanged water 1000 parts by mass The above materials are mixed and heated. While stirring, emulsion liquid-E1 for hydrophilic organic resin was prepared.

-Styrene / n-butyl acrylate / methacrylic acid copolymer (polar monomer ratio 1.5 mol%) 10 parts by mass-Block polymer E 4 parts by mass-Ion-exchanged water 100 parts by mass Vibration was applied to prepare an emulsion liquid-E2 for a hydrophobic organic resin.

  The two types of emulsion liquids -E1 and -E2 were mixed and stirred, and then granulated using a Spray-Dry machine (NL-5 / manufactured by Okawara Kako Co., Ltd.). Further, the particles were classified with an airflow classifier.

For 100 parts by mass of classified particles,
・ 0.5 parts by mass of amorphous silica (Aerosil A130 / Degussa) ・ 0.5 parts by mass of amorphous silica (Aerosil RX200 / Degussa) was mixed by stirring to prepare ink receiving particles E as composite particles. Obtained.

The average particle diameter in terms of sphere of the ink receiving particles E was 5.5 μm.
The particle diameters of the hydrophilic organic resin particles and the hydrophobic organic resin particles in the ink receiving particles E were 0.11 μm and 0.10 μm, respectively.

-Production of particles F-
-Styrene / n-butyl methacrylate / acrylic acid copolymer (polar monomer ratio 35 mol%) 100 parts by mass-Sodium hydroxide 11.3 parts by mass-Ion-exchanged water 1000 parts by mass While mixing and heating the above materials Stirring to prepare emulsion liquid-F1 for hydrophilic organic resin.

-25 parts by mass of styrene / n-butyl methacrylate / acrylic acid copolymer (polar monomer ratio 2.5 mol%)-7.5 parts by mass of block polymer F-250 parts by mass of ion-exchanged water Ultrasonic vibration was applied to prepare an emulsion liquid-F2 for a hydrophobic organic resin.

  The two types of emulsion liquids -F1 and -F2 were mixed and stirred, and then granulated using a Spray-Dry machine (NL-5 / manufactured by Okawara Chemical Co., Ltd.). Further, the particles were classified with an airflow classifier.

For 100 parts by mass of classified particles,
・ Amorphous silica (Aerosil A130 / Degussa) 0.25 parts by mass ・ Amorphous silica (Aerosil RX200 / Degussa) 0.75 parts by mass was stirred and mixed, and the ink receiving particles F, which are composite particles, were mixed. Obtained.

The sphere equivalent average particle diameter of the ink receiving particles F was 6 μm.
The particle diameters of the hydrophilic organic resin particles and the hydrophobic organic resin particles in the ink receiving particles F were 0.13 μm and 0.06 μm, respectively.

-Production of particles G-
-Styrene / 2-ethylhexyl acrylate / acrylic acid copolymer (polar monomer ratio 60 mol%) 100 parts by mass-Sodium hydroxide 7.6 parts by mass-Ion-exchanged water 1000 parts by mass While mixing the above materials and heating Stirring to prepare emulsion liquid-G1 for hydrophilic organic resin.

-Styrene / 2-ethylhexyl acrylate / methacrylic acid copolymer (polar monomer ratio 8 mol%) 25 parts by mass-Block polymer G 2.5 parts by mass-Ion exchange water 250 parts by mass Vibration was applied to prepare an emulsion liquid-G2 for a hydrophobic organic resin.

  The two types of emulsion liquids -G1 and -G2 were mixed and stirred, and then granulated using a Spray-Dry machine (NL-5 / manufactured by Okawara Chemical Co., Ltd.). Further, the particles were classified with an airflow classifier.

For 100 parts by mass of classified particles,
・ 0.5 parts by mass of amorphous silica (Aerosil A130 / Degussa) ・ 0.5 parts by mass of amorphous silica (Aerosil RX200 / Degussa) were mixed by stirring to prepare ink receiving particles G that are composite particles. Obtained.

The average spherical particle diameter of the ink receiving particles G was 7 μm.
The particle diameters of the hydrophilic organic resin particles and the hydrophobic organic resin particles in the ink receiving particles G were 0.068 μm and 0.04 μm, respectively.

-Production of particles H-
-Styrene / n-butyl acrylate / methacrylic acid copolymer (polar monomer ratio 12.5 mol%) 100 parts by mass-Sodium hydroxide 4.3 parts by mass-Ion-exchanged water 1000 parts by mass The above materials are mixed and heated. While stirring, emulsion liquid-H1 for hydrophilic organic resin was prepared.

-15 parts by mass of styrene / n-butyl acrylate / acrylic acid copolymer (polar monomer ratio 1 mol%)-0.15 parts by mass of block polymer H-150 parts by mass of ion-exchanged water Vibration was applied to prepare an emulsion liquid-H2 for a hydrophobic organic resin.

  The two types of emulsion liquids -H1 and -H2 were mixed and stirred, and then granulated using a Spray-Dry machine (NL-5 / manufactured by Okawara Kako Co., Ltd.). Further, the particles were classified with an airflow classifier.

For 100 parts by mass of classified particles,
・ Amorphous silica (Aerosil A130 / Degussa) 0.25 parts by mass ・ Amorphous silica (Aerosil RX200 / Degussa) 0.75 parts by mass was stirred and mixed, and the ink receiving particles H, which are composite particles, were mixed. Obtained.

The average spherical particle diameter of the ink receiving particles H was 8 μm.
The particle diameters of the hydrophilic organic resin particles and the hydrophobic organic resin particles in the ink receiving particles H were 0.3 μm and 0.06 μm, respectively.

-Production of particles I-
-Styrene / n-butyl methacrylate / methacrylic acid copolymer (polar monomer ratio 80 mol%) 100 parts by mass-Sodium hydroxide 5.2 parts by mass-Ion-exchanged water 1000 parts by mass While mixing the above materials and heating The mixture was stirred to prepare emulsion liquid-I1 for hydrophilic organic resin.

-Styrene / n-butyl methacrylate / methacrylic acid copolymer (polar monomer ratio 9 mol%) 20 parts by mass-Block polymer I 5 parts by mass-Ion-exchanged water 200 parts by mass The emulsion liquid-I2 for hydrophobic organic resins was prepared.

  The two types of emulsion liquids -I1 and -I2 were mixed and stirred, and then granulated using a Spray-Dry machine (NL-5 / manufactured by Okawara Chemical Co., Ltd.). Further, the particles were classified with an airflow classifier.

For 100 parts by mass of classified particles,
・ 0.5 parts by mass of amorphous silica (Aerosil A130 / Degussa) ・ 0.5 parts by mass of amorphous silica (Aerosil RX200 / Degussa) was mixed by stirring to prepare ink receiving particles I as composite particles. Obtained.

The average spherical particle diameter of the ink receiving particles I was 7.5 μm.
Further, the particle diameters of the hydrophilic organic resin particles and the hydrophobic organic resin particles in the ink receiving particles I were 0.17 μm and 0.06 μm, respectively.

-Production of particles J-
-Styrene / 2-ethylhexyl acrylate / acrylic acid copolymer (polar monomer ratio 30 mol%) 100 parts by mass-Sodium hydroxide 6.4 parts by mass-Ion-exchanged water 1000 parts by mass While mixing the above materials and heating The mixture was stirred to prepare emulsion liquid-J1 for hydrophilic organic resin.

・ Styrene / n-butyl acrylate / n-butyl methacrylate / acrylic acid copolymer (polar monomer ratio 10 mol%) 20 parts by mass ・ Ion-exchanged water 200 parts by mass Ultrasonic vibration is applied to the mixture of the above materials. Thus, an emulsion liquid-J2 for a hydrophobic organic resin was prepared.

  The two types of emulsion liquids -J1 and -J2 were mixed and stirred, and then granulated using a Spray-Dry machine (NL-5 / manufactured by Okawara Chemical Co., Ltd.). Further, the particles were classified with an airflow classifier.

For 100 parts by mass of classified particles,
・ 0.5 parts by mass of amorphous silica (Aerosil A130 / Degussa) ・ 0.5 parts by mass of amorphous silica (Aerosil RX200 / Degussa) were mixed with stirring to prepare ink-receptive particles J as composite particles. Obtained.

The average spherical particle diameter of the ink receiving particles J was 5 μm.
The particle diameters of the hydrophilic organic resin particles and the hydrophobic organic resin particles in the ink receiving particles J were 0.22 μm and 0.12 μm, respectively.

-Production of particles K-
-Styrene / n-butyl methacrylate / acrylic acid copolymer (polar monomer ratio 40 mol%) 100 parts by mass-Sodium hydroxide 7.6 parts by mass-Ion-exchanged water 1000 parts by mass While mixing the above materials and heating The mixture was stirred to prepare emulsion liquid-K1 for hydrophilic organic resin.

-15 parts by mass of styrene / n-butyl acrylate / n-butyl methacrylate / acrylic acid copolymer (polar monomer ratio 10 mol%)-1.5 parts by mass of block polymer C-150 parts by mass of ion-exchanged water The above materials are mixed The obtained liquid was subjected to ultrasonic vibration to prepare an emulsion liquid-K2 for a hydrophobic organic resin.

  The two types of emulsion liquids -K1 and -K2 were mixed and stirred, and then granulated using a Spray-Dry machine (NL-5 / manufactured by Okawara Kako Co., Ltd.). Further, the particles were classified with an airflow classifier.

For 100 parts by mass of classified particles,
・ 0.5 parts by mass of amorphous silica (Aerosil A130 / Degussa) ・ 0.5 parts by mass of amorphous silica (Aerosil RX200 / Degussa) were mixed with stirring to prepare ink-receptive particles K as composite particles. Obtained.

The average particle diameter in terms of sphere of the ink receiving particles K was 5.5 μm.
The particle diameters of the hydrophilic organic resin particles and the hydrophobic organic resin particles in the ink receiving particles K were 0.22 μm and 0.06 μm, respectively.

-Production of particles L-
A particle L was prepared in the same manner as the preparation of the particle A except that the block polymer A was not added in the preparation of the particle A.

  The characteristics of the particles A to L produced above are summarized in Table 2.

Abbreviations in Table 2 mean the following:
AA: acrylic acid, MAA: methacrylic acid, MA: maleic acid, St: styrene, n-BMA: n-butyl methacrylate, 2-EHA: 2-ethylhexyl acrylate, n-BA: n-butyl acrylate

-Preparation of ink A-
Ink A was prepared by mixing and stirring the following ink components, followed by filtration using a membrane filter having a pore size of 5 μm.

(Ink component)
・ Cabojet 300 (manufactured by Cabot Corporation) 4.5 mass parts ・ diethylene glycol 15 mass parts ・ glycerin 15 mass parts ・ Surfinol 465 (manufactured by Nissin Chemical) 1 mass part ・ ion-exchanged water 64.5 mass parts

  The obtained ink A had a surface tension = 30 mN / m, a viscosity = 3.0 mPa · s, and a pH = 8.2.

-Preparation of ink B-
Ink B was prepared by mixing and stirring the following ink components, followed by filtration using a membrane filter having a pore size of 5 μm.

(Ink component)
・ Cabojet 250 (Cabot Corporation) 4 parts by mass ・ Diethylene glycol 15 parts by mass ・ Glycerin 15 parts by mass ・ Surfinol 465 (Nisshin Chemical Co., Ltd.) 1.5 parts by mass ・ Ion-exchanged water 64.5 parts by mass

  The obtained ink B had a surface tension = 30 mN / m, a viscosity = 3.1 mPa · s, and a pH = 7.8.

-Preparation of ink C-
The following ink components were mixed, stirred, and then filtered using a membrane filter having a pore size of 5 μm to prepare ink C.

(Ink component)
・ Cabojet 260 (manufactured by Cabot) 4 parts by mass ・ 15 parts by mass of diethylene glycol ・ 15 parts by mass of glycerin ・ Surfinol 465 (manufactured by Nissin Chemical Co., Ltd.) 1.5 parts by mass

  The obtained ink C had a surface tension = 30 mN / m, a viscosity = 3.2 mPa · s, and a pH = 7.6.

-Preparation of ink D-
Ink D was prepared by mixing and stirring the following ink components, followed by filtration using a membrane filter having a pore size of 5 μm.

(Ink component)
・ Cabojet 270 (manufactured by Cabot) 4 parts by mass ・ 15 parts by mass of diethylene glycol ・ 15 parts by mass of glycerin ・ Surfinol 465 (manufactured by Nissin Chemical) 1.5 parts by mass ・ 64.5 parts by mass of ion-exchanged water

  The obtained ink D had a surface tension = 31 mN / m, a viscosity = 3.0 mPa · s, and a pH = 8.1.

[Examples 1-9, Comparative Examples 1-3]
Each of the above particles was used as ink receiving particles, and any of the above inks A to D was used in the combinations shown in Table 3 below, and the following evaluation was performed. The results are shown in Table 3.

<Evaluation>
-Chargeability (particle layer uniformity)-
A two-component developer (mixed) is mixed with any of the ink receiving particles A to L and a conductive magnetic carrier (ferrite core, conductive resin coat, volume resistivity 1 × 10 ¹¹ Ω · m, average particle size 50 μm). Ratio: ink receptive particles / carrier = 8/92). Then, this developer was filled in a prototype particle supply device and stirred for 12 hours. By this mixing and stirring, electric charge was injected into the ink receiving particles through the mag roll and the carrier and negatively charged.
Then, the negatively charged ink receiving particles were opposed to the intermediate transfer member positively charged with a predetermined surface potential (500 V), and the ink receiving particles were supplied onto the intermediate transfer member. At this time, the supply amount of the ink receiving particles onto the intermediate transfer member was different depending on the kind of the particles, but was in the range of 5 g / m ^{2 to} 12 g / m ² .
The chargeability was evaluated based on the state of particles dispersed on the intermediate transfer member at this time. The evaluation criteria are as follows.

(Double-circle): When observing with a microscope, the particle | grains have spread evenly on the intermediate transfer body.
○: When visually observed, it is uniformly distributed on the intermediate transfer member.
X: Although there is unevenness, it can be sprayed.

-Optical density-
In the same manner as in the evaluation method of chargeability (particle layer uniformity), ink receiving particles were dispersed on the intermediate transfer member. At this time, the supply amount of the ink receiving particles onto the intermediate transfer member was different depending on the kind of the particles, but was in the range of 5 g / m ^{2 to} 12 g / m ² .

Then, on the supplied layer of ink receiving particles, 2 pL at an image area ratio of 1200 × 1200 dpi (dpi: number of dots per inch) from a recording head of a piezo-type inkjet device (prototype / manufactured by Fuji Xerox Co., Ltd.). Was applied to form a line image.
OK Kanto (manufactured by Oji Paper Co., Ltd.) as a recording medium and an ink receiving particle layer on which an image was formed on an intermediate transfer body were pressed at 3 × 10 ⁵ Pa, and the recording medium was heated at 90 ° C. for 1 minute. Fixing was performed. The optical density of the image portion thus obtained was measured with X-Rite 404 (manufactured by X-Rite). The evaluation criteria are as follows.

◎: Optical density is 1.45 or more ○: Optical density is 1.4 or more and less than 1.45 Δ: Optical density is 1.3 or more and less than 1.4 ×: Optical density is less than 1.3

-Drying time (liquid absorption speed)-
In the same manner as in the evaluation method of chargeability (particle layer uniformity), ink receiving particles were dispersed on the intermediate transfer member. At this time, the supply amount of the ink receiving particles onto the intermediate transfer member was different depending on the kind of the particles, but was in the range of 5 g / m ^{2 to} 12 g / m ² .
Then, ink is applied to the supplied ink receptive particle layer from the recording head of a piezo-type ink jet apparatus (prototype / manufactured by Fuji Xerox Co., Ltd.) so as to be 4.5 g / m ^2, and 100% coverage. A pattern was formed.
Plain paper (C2 paper: manufactured by Fuji Xerox Co., Ltd.) was pressed against the formed image portion with a load of 2 × 10 ⁴ Pa, and the time until ink was not transferred to the plain paper side was measured. The evaluation criteria are as follows.

◎: Drying time less than 0.5 seconds ○: Drying time 0.5 seconds or more and less than 1 second △: Drying time 1 seconds or more and less than 3 seconds ×: Drying time 3 seconds or more

-Bleeding-
In the same manner as the image forming method in the evaluation of the optical density, an image was formed by forming a 1 dot line pattern. A sensory evaluation was performed by referring to a limit sample in which the degree of bleeding of the line was determined in advance. The evaluation criteria are as follows.
(Double-circle): Even if an image part is confirmed as an enlarged image (25 times), bleeding is not confirmed.
○: When an image portion is confirmed as an enlarged image (25 times), bleeding can be confirmed, but it cannot be visually determined and is within an allowable range.
(Triangle | delta): Although blur is recognized to an image part visually, it is in an allowable range.
X: Bleeding is visually recognized in the image portion, the degree thereof is intense, and is outside the allowable range.

  As shown in Table 3, it can be seen that Examples 1 to 9 are better results than Comparative Examples 1 to 3.

It is a conceptual diagram which shows an example of the ink receptive particle which concerns on embodiment. It is a conceptual diagram which shows another example of the ink receptive particle which concerns on embodiment. It is a perspective view which shows the ink receptive particle | grain storage cartridge which concerns on embodiment. It is AA sectional drawing of FIG. It is a block diagram which shows the recording device which concerns on embodiment. FIG. 2 is a configuration diagram illustrating a main part of a recording apparatus according to an embodiment. It is a block diagram which shows the ink receptive particle layer which concerns on embodiment. It is a block diagram which shows the recording device which concerns on other embodiment. It is a block diagram which shows the principal part of the recording device which concerns on other embodiment. It is a figure which shows notionally the process in which an image is formed in the recording device which concerns on other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Recording apparatus 11 Recording apparatus 12 Intermediate transfer body 13 Conveying belt 14 Release agent supply apparatus 14A Release layer 14B Blade 14C Supply roller 14D Release agent 16 Ink receiving particle 16A Ink receiving particle layer 16B Image layer 16D Residual particle 17 Carrier 18 Ink receiving particle supply device 18A Mag roll 18B Restricting member 19 Ink receiving particle storage cartridge 19A Supply tube 20 Inkjet recording head 20A Ink droplet 20B Nozzle surface 22 Transfer fixing device 22A Heating roll 22B Pressure roll 23 Fixing device 23A Heating roll 23B Pressurizing roll 24 Cleaning device 28 Charging device 29 Static elimination device 31 Follower roll 50 Ink-receptive particle storage cartridge 51 Particle storage cartridge main body 52 Side wall portion 54 Side wall portion 56 Band portion 58 Storage portion 60 Unloading port 64 Cup Ring portion 66 connecting portion 68 Agitator 100,110 ink receiving particles 101 and 111 hydrophilic organic resin 102, 112 hydrophobic organic resin 103 and 113 block copolymer 104, 114, inorganic particles

Claims (8)

A hydrophilic organic resin;
A hydrophobic organic resin,
A block copolymer having a structural unit derived from a polar monomer and a structural unit derived from a non-polar monomer,
The absolute value of the difference between the solubility parameter (SP value) of the polar monomer of the block copolymer and the solubility parameter (SP value) of the polar monomer constituting the hydrophilic organic resin is 2 or less, Ink-receiving particles that receive ink.   The ink receiving particles according to claim 1, wherein the polar monomer in the block copolymer has the same chemical structure as that of the polar monomer constituting the hydrophilic organic resin. Ink,
Ink-receiving particles according to claim 1 or 2,
An ink recording material comprising: A supplying step of supplying the ink receiving particles according to claim 1 or 2 onto the intermediate transfer member;
An ink discharge step of discharging ink to the ink receiving particles supplied onto the intermediate transfer member;
A transfer step of transferring the ink receiving particles to a recording medium;
A fixing step of fixing the ink receiving particles transferred to the recording medium;
A recording method. A supply step of supplying the ink receiving particles according to claim 1 or 2 onto a recording medium;
An ink ejection step for ejecting ink to the ink receiving particles supplied on the recording medium;
A fixing step of fixing the ink receiving particles supplied on the recording medium;
A recording method. An intermediate transfer member;
A supply device for supplying the ink receiving particles according to claim 1 or 2 onto the intermediate transfer member;
An ink discharge device for discharging ink to the ink receiving particles supplied onto the intermediate transfer member;
A transfer device for transferring the ink receiving particles to a recording medium;
A fixing device for fixing the ink receiving particles transferred to the recording medium;
A recording apparatus. A supply device for supplying the ink receiving particles according to claim 1 or 2 onto a recording medium;
An ink ejection device for ejecting ink to the ink receiving particles supplied on the recording medium;
A fixing device for fixing the ink receiving particles supplied on the recording medium;
A recording apparatus.   An ink receiving particle storage container which is detached from the recording apparatus and stores the ink receiving particles according to claim 1.