JP2010076214A - Ink acceptable particle, recording device, material for recording, and cartridge for storing ink acceptable particle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink acceptable particle which can accept various types of ink and also can improve liquid absorbing property, and to provide a material for recording utilizing the ink acceptable particle, a recording device and a cartridge for storing the ink acceptable particle. <P>SOLUTION: For example, a particle layer is formed on an intermediate transfer body. Ink droplets are discharged on the particle layer to form an image, and the ink acceptable particles are made to accept the ink. A recording medium is laid on the intermediate transfer body to overlap each other and is fixed after an ink acceptable particle layer is transferred on the recording medium. As the ink acceptable particles 200 applicable to the recording device, hydrophilic particles, which contain a hydrophilic resin and in which degree of neutralization of the hydrophilic resin of a surface layer is higher than that of the hydrophilic resin of a central part, are used. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to ink receiving particles. The present invention also relates to a recording apparatus, a recording material, and an ink receiving particle storage cartridge using the ink receiving particles.

  As a recording method using ink, a method of recording on an intermediate and then transferring to a recording medium has been proposed.

For example, Patent Document 1 discloses an ink receiving particle that includes ink receiving particles that receive ink including a recording material, has a trap structure that traps at least a liquid component of ink, and includes a liquid absorbing resin. 2. Description of the Related Art A recording apparatus has been proposed in which a conductive particle is supplied to an intermediate transfer member, and then ink is ejected onto the intermediate transfer member and transferred to a recording medium.
JP 2006-347085 A

  An object of the present invention is to provide ink receiving particles that suppress stickiness of an image after fixing.

The above problem is solved by the following means. That is,
The invention according to claim 1
It is comprised including a hydrophilic resin having at least one kind of acidic functional group, and the amount of the acidic functional group per 1 g of the particles is 1.4 × 10 ⁻³ mol / g or more and 4.0 × 10 ⁻³ mol / g. Ink-receptive particles having hydrophilic particles that are soluble in a mixed solvent of isopropyl alcohol and water in which the particles are mixed at a ratio in a predetermined range.
Here, “the ratio of the predetermined range” means that the ratio of the mixed solvent of isopropyl alcohol and water is “the blending ratio of isopropyl alcohol in 100% by mass of the mixed solvent is 45% by mass or more and 65% by mass or less”. It means that.

The invention according to claim 2
The ink receiving particles according to claim 1, comprising composite particles in which the hydrophilic particles are gathered.

The invention according to claim 3
An intermediate transfer member;
Supply means for supplying the ink receiving particles according to claim 1 or 2 onto the intermediate transfer member;
An ink ejection means for ejecting ink to the ink receiving particles supplied onto the intermediate transfer member;
Transfer means for transferring the ink receiving particles to a recording medium;
Fixing means for fixing the ink receiving particles transferred to the recording medium;
A recording apparatus.

The invention according to claim 4
Supply means for supplying the ink receiving particles according to claim 1 or 2 onto a recording medium;
Ink ejection means for ejecting ink onto the ink receiving particles supplied on the recording medium;
Fixing means for fixing the ink receiving particles supplied on the recording medium;
A recording apparatus.

The invention according to claim 5
A recording material comprising ink and the ink receiving particles according to claim 1.

The invention according to claim 6
An ink receptive particle storage cartridge 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, stickiness of the image after fixing is suppressed as compared with the case where the configuration of the present invention is not provided.
According to the invention of claim 2, the liquid absorbency is improved as compared with the case where the ink receiving particles are hydrophilic particles alone.
According to the third, fourth, fifth, and sixth aspects of the invention, an image in which stickiness of the image after fixing is suppressed can be obtained as compared with the case where the configuration of the present invention is not provided.

Hereinafter, embodiments of the present invention will be described in detail.
(Ink-receptive particles)
The ink receiving particles according to the embodiment receive ink components when the ink comes into contact with the particles. Here, the ink receptivity indicates holding at least a part (at least a liquid component) of the ink component.

In the ink receiving particles according to the present embodiment, the amount of the acidic functional group per 1 g of the hydrophilic particles is 1.4 × 10 ⁻³ mol / g or more and 4.0 × 10 ⁻³ mol / g or less. However, it is desirably 2.1 × 10 ⁻³ mol / g or more and 3.2 × 10 ⁻³ mol / g or less.

This acidic functional group is measured as follows.
First, hydrophilic particles are added and dissolved in a specific ratio of isopropyl alcohol (IPA) / water mixed solvent (IPA / water = 65/35 or more and 45/55 or less: mass ratio).

  Next, when all are dissolved, the solution is processed, and when an insoluble residue is present, the supernatant is centrifuged and then processed. That is, using the solution or supernatant as the titration solution, using the KOH aqueous solution, the consumption of the KOH aqueous solution is measured according to the acid value potentiometry method of JIS K2501 (potentiometer and pH meter are used for the measurement). The mol amount of the acidic functional group is calculated. Based on this, the functional group amount is calculated.

  In the ink receiving particles according to the present embodiment, the hydrophilic particles are dissolved in a mixed solvent of isopropyl alcohol and water in which particles to be dissolved are mixed in a ratio within a predetermined range. The hydrophilic particles configured to include a hydrophilic resin having an acidic functional group are all dissolved when the amount of the acidic functional group is not delocalized in the particle and does not vary. On the other hand, when the amount of the acidic functional group is localized in the particle and varies, the region having the acidic functional group amount lower than other regions is not partially dissolved and remains as an insoluble residue. Therefore, the smaller the insoluble residue, the better. The dissolution of the hydrophilic particles in the specific mixed solvent means that the amount of acidic functional groups is delocalized and there is little variation. For example, the amount of acidic functional groups Means that the particle surface layer portion and the central portion are substantially equal.

  Here, when the hydrophilic particles are dissolved in the specific mixed solvent, it is visually determined that 0.5 g of the hydrophilic particles does not generate a precipitate or a residue with respect to 100 g of the specific mixed solvent at 25 ° C. is doing.

  In order to obtain the hydrophilic particles having the above structure, for example, at least the hydrophilic resin is dissolved in an organic solvent (for example, methyl ethyl ketone, methyl acetate, isopropyl acetate, tetrahydrofuran, acetone, isopropyl alcohol, dimethylformamide, or a mixed solvent thereof). When performing neutralization (salt formation) treatment, after neutralization (salt formation) treatment (specifically, for example, alkali treatment) in an organic solvent in which the resin is dissolved, for example, the organic solvent is a poor solvent. (For example, water) is added to emulsify the hydrophilic resin. Then, it is dried and granulated, and pulverized and classified as necessary.

  Hereinafter, the ink receiving particles according to the present embodiment will be described in more detail. First. The particle form of the ink receiving particles according to this embodiment will be described.

  The ink receiving particles according to the present embodiment may be composed of single particles of hydrophilic particles (hereinafter, may be referred to as “primary particles”) configured to include the hydrophilic resin, or at least hydrophilic. The composite particle | grains which the particle | grains aggregated may be sufficient. The single particles of the hydrophilic particles or the composite particles in which at least the hydrophilic particles are aggregated may be referred to as “mother particles”.

When the mother particles are composed of primary particles, the emulsion is obtained by subjecting the emulsion (emulsion) obtained by emulsifying at least the hydrophilic resin to a drying treatment such as freeze drying. Thereafter, pulverization / classification may be performed as necessary.
On the other hand, when the mother particles are composed of composite particles, the emulsion (emulsion) obtained by emulsifying at least the hydrophilic resin is dried and granulated (composite) by, for example, spray drying (spray drying) or the like. ) Obtained by processing. Further, when a composite particle is formed by combining hydrophilic particles and other particles (inorganic particles, hydrophobic particles, wax particles, etc.), for example, the other particles are added to the emulsion liquid (emulsion liquid). Are mixed and dried and granulated (composited). Thereafter, pulverization / classification may be performed as necessary.

  Here, when the ink receptive particles are composed of single particles of hydrophilic particles, when the ink receptive particles receive the ink, if the ink adheres to the ink receptive particles, at least the liquid component of the ink is hydrophilic. Absorbed by the particles.

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

  On the other hand, when the ink receiving particles are composed of composite particles in which at least hydrophilic particles are aggregated, when the ink receiving particles receive ink, first, when the ink adheres to the ink receiving particles, at least the ink It is considered that the liquid component is trapped by the voids between the particles (at least hydrophilic particles) constituting the composite particles (hereinafter, the interparticle voids may be referred to as “trap structure”). At this time, it is considered that the recording material among the ink components adheres to the surface of the ink receiving particles or is trapped by the trap structure. And it is thought that the ink which exists in this space | gap is absorbed with a particle | grain. In this way, the ink receiving particles receive ink. Then, recording is performed by transferring the ink receiving particles that have received the ink to a recording medium.

  The trapping of the ink component (liquid component, recording material) by this trapping structure is considered to be physical and / or chemical trapping by the voids between particles (physical particle wall structure).

  And by applying a form composed of composite particles in which at least hydrophilic particles are aggregated, in addition to trapping (trap) by voids (physical particle wall structure) between the particles constituting the composite particles, It is considered that the ink liquid component is absorbed and held by the hydrophilic particles.

  Hereinafter, the particle form of the ink receiving particles according to the present embodiment will be described in more detail. As described above, the ink receiving particles according to the present embodiment may be in a form in which the mother particles are composed of hydrophilic particles alone, or at least composed of composite particles in which hydrophilic particles are aggregated. There may be a form.

  Further, the hydrophilic particles may contain other components (for example, inorganic materials, hydrophobic resins, release agents (waxes), etc.) in addition to the organic resin. On the other hand, examples of the particles constituting the composite particles other than the liquid absorbing particles include inorganic particles, hydrophobic particles, release agent particles (wax particles), and the like.

  In addition, for example, inorganic particles or the like may adhere to the surface of the hydrophilic particles or composite particles.

  As specific configurations of the ink receiving particles according to the present embodiment, for example, as shown in FIG. 1, mother particles 202 made of single particles of hydrophilic particles 201 and mother particles 202 (hydrophilic particles 201). The form of the ink receptive particle 200 which has the inorganic particle 204 adhering to the surface is mentioned. Further, as shown in FIG. 2, composite particles in which hydrophilic particles 201 and other particles 203 (for example, inorganic particles, hydrophobic particles including a hydrophobic resin, wax particles, etc.) are combined. A form of the ink receiving particles 210 having the mother particles 202 made of the inorganic particles 204 attached to the surfaces of the mother particles 202 (composite particles) is also included. In this composite particle, a void structure is formed by voids between the particles. Moreover, these forms are examples, and are not limited thereto. For example, the form in which the inorganic particles 204 are not attached (externally added), or the form in which the composite particles are configured with only the hydrophilic particles 201 may be employed. .

Here, the average particle diameter in terms of sphere of the entire ink receiving particles is, for example, in the range of 0.5 μm to 50 μm (desirably 1 μm to 30 μm, more desirably 3 μm to 20 μm, and even more desirably 5 μm to 10 μm). ).
Here, the sphere equivalent average particle diameter is obtained as follows. Although the optimum method differs depending on the particle size, various methods are used such as, for example, dispersing particles in a liquid and obtaining a particle size by the light scattering principle, and obtaining a projected image of particles by image processing. Examples of the method used for general purposes include the Microtrac UPA method and the Coulter counter method.

  When the mother particles are composed of composite particles, the mass ratio of hydrophilic particles to other particles (hydrophilic particles: other particles) is, for example, 5: 1 or more when the other particles are inorganic particles. The range of 10 or less is mentioned.

  Further, the particle diameter of the mother particles is, for example, in the range of sphere-converted average particle diameter of 0.1 to 50 μm, desirably 0.5 to 25 μm, more desirably 1 to 10 μm. When the average particle diameter in terms of sphere is in the above range, high image quality is achieved. That is, when the sphere-converted average particle size is large, a step in the height direction is generated between a portion where particles are present and a portion where particles are not present on the image surface, so that the smoothness of the image may be inferior. On the other hand, when the sphere-converted average particle size is small, the handling property of the powder tends to be lowered and the powder cannot be supplied to a desired position on the transfer body. Therefore, there are places where hydrophilic particles are not present on the image, and high-speed recording and high image quality may not be achieved. When the ink receiving particles are composed of primary particles, it is preferable to apply the range in terms of the sphere-converted average particle size.

In the case of constituting the matrix particles are composite particles, the BET specific surface area _{(N 2)} and the like in the range of for example ^{1 m} 2 / g or more 750 meters ² / g or less.

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

  In addition, the particle diameter of the hydrophilic particles is, when the primary particles are used as mother particles, the sphere equivalent average particle diameter is, for example, 0.1 μm to 50 μm, desirably 0.5 μm to 25 μm, more desirably 1 μm to 10 μm. The following ranges are mentioned. On the other hand, when constituting the composite particles, the particle diameter of the hydrophilic particles is, for example, 10 nm to 30 μm, preferably 50 nm to 1 μm, more preferably 50 nm to 700 nm in terms of sphere-average particle diameter. .

  Further, the ratio of the hydrophilic particles to the whole ink receiving particles is, for example, 75% or more, desirably 85% or more, more desirably 90% or more and 99% or less in terms of mass ratio.

Hereinafter, each material will be described in detail.
First, the hydrophilic resin will be described. The hydrophilic resin is a hydrophilic resin having at least one kind of acidic functional group.

  Here, examples of the acidic functional group as the functional group include a weak acidic functional group and a strong acidic functional group. The weakly acidic functional group means a group that dissociates almost or only partly in an aqueous solution, and examples thereof include a hydroxyl group, an ethylene oxide group, and a carboxylic acid group. The strongly acidic functional group means a group that dissociates almost completely in an aqueous solution, and examples thereof include a sulfonic acid group.

  For example, when the particles are negatively charged, it is desirable to use an organic acid monomer containing an acidic functional group such as a carboxylic acid group or a sulfonic acid group.

Among these functional groups, an acidic functional group, more desirably a weak acidic functional group, particularly a carboxylic acid group is desirable. This functional group has a low dissociation constant, and the suppression of image stickiness is improved as compared with other functional groups.
In particular, when it has a carboxylic acid group, it is difficult to dissociate when it is unneutralized (when it does not have a salt structure) under humidity in the air, and dissociates with ink (weakly alkaline liquid), which is advantageous for storage stability. It is. Further, when it has a carboxylic acid group, it is cross-linked (pseudo-crosslinked) with ions in the ink, and the whole system (ink + ink receiving particles) is easily fixed, which is advantageous for fixing properties.

  The hydrophilic resin may be one in which the functional group does not have a salt structure (salt-formed structure), or at least a part of the functional group has a salt structure (salt-formed structure). May be used.

  Here, examples of the structure (salt structure) of the salt-formed functional group preferably include a salt structure with an alkali metal, a salt structure with a polyvalent metal, and a salt structure with an organic amine. In addition, the salt structure by ammonia is also mentioned. That is, the salt formation treatment (neutralization treatment) may be performed with these materials.

  Here, the hydrophilic resin may consist of a copolymer of a hydrophilic monomer having the functional group and a hydrophobic monomer, or a polymer of a hydrophilic monomer having the functional group alone. It may consist of. In addition, not only the monomer but also a graft copolymer or block copolymer in which other units such as a polymer / oligomer structure are copolymerized as a start may be used.

  In addition, it is desirable that the hydrophilic resin has the above functional group and the ratio of the hydrophilic monomer having the above functional group to all monomer components is 10 mol% or more and 100 mol% or less. The ratio of the hydrophilic monomer having the functional group is determined as follows. First, the constitution of the organic component is specified from analysis methods such as mass spectrometry, NMR (nuclear magnetic resonance), and IR (infrared absorption spectrum). Then, based on JIS K0070 or JIS K2501, the acid value and base number of an organic component are measured. The ratio of the polar monomer is determined by calculation from the constitution of the organic component and the acid value / base value.

As the hydrophilic unit or monomer, -OH, -EO unit (ethylene oxide group), -COOM (M is an alkali metal such as hydrogen, Na, Li, K, ammonia, organic amines as the above functional group. and the _{like), -. 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, and phenyl, etc. ), -NR ₄ X (R is, for example, H, alkyl, phenyl, etc., X is, for example, halogen, sulfate radical, acid anions such as carboxylic acid, BF ₄ , etc.) Or a monomer is mentioned.

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

  The hydrophilic resin is softened and contributes to fixing properties because the ink liquid component (for example, water, aqueous solvent) that has been absorbed acts as a plasticizer for the resin (polymer).

  The hydrophilic resin may be composed of, for example, a homopolymer of a hydrophilic monomer, or a copolymer composed of both a hydrophilic monomer and a hydrophobic monomer, In order to obtain a weak water-absorbing resin, the copolymer is desirable.

  The weight average molecular weight of the hydrophilic resin is adjusted to, for example, 5000 or more and 100,000 or less. The weight average molecular weight is measured under the following conditions. For example, GPC uses “HLC-8120GPC, SC-8020 (manufactured by Tosoh Corporation)” apparatus, and two columns are “TSKgel, SuperHM-H (6.0 mm ID × 15 cm, manufactured by Tosoh Corporation)”. And THF (tetrahydrofuran) was used as the eluent. As experimental conditions, the sample concentration was 0.5%, and the flow rate was 0.6 ml / min. The experiment was conducted using a sample injection amount of 10 μl, a measurement temperature of 40 ° C., and an IR detector. The calibration curve is “polystylen standard sample TSK standard” manufactured by Tosoh Corporation: “A-500”, “F-1”, “F-10”, “F-80”, “F-380”, “A-2500”. ”,“ F-4 ”,“ F-40 ”,“ F-128 ”, and“ F-700 ”.

  The acid value of the hydrophilic resin is adjusted to, for example, 50 mgKOH / g or more and 500 mgKOH / g or less in terms of carboxylic acid group (—COOH).

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

  Further, the ink receiving particles according to the present embodiment may contain a release agent (wax). The release agent may be included in the hydrophilic particles together with the hydrophilic resin, or the release agent particles (wax particles) may be combined with the hydrophilic particles.

  The ink receptive particles according to the present embodiment described above may be used alone or in combination with a carrier. In addition, as a carrier, the carrier used for the developer of the toner for electrophotography can be applied, for example.

(Recording material)
The recording material of the present embodiment includes at least an ink containing a recording material and the ink receiving particles according to the present embodiment. The recording material can perform recording by causing the ink receiving particles to receive ink and then transferring the ink receiving particles to a recording medium.

  Hereinafter, the ink will be described in detail. The ink may be used with 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 coloring material, either a dye or a pigment may 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 this 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.

  Specific examples of the black pigment include Raven 7000 (manufactured by Columbian Carbon), Regal 400R (manufactured by Cabot), and Color Black FW1 (manufactured by Degussa), but are not limited thereto.

  Specific examples of the cyan pigment include C.I. I. Pigment Blue-1 is exemplified, but not limited thereto.

  Specific examples of the magenta color pigment include C.I. I. Pigment Red-5 can be used, but the present invention is not limited to these.

  Specific examples of yellow pigments include C.I. I. Pigment Yellow-1 may be mentioned, but the invention is not limited to these.

  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 are 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 is also used.

  You may use the pigment self-dispersible in water as a coloring 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 and CW-2 manufactured by Orient Chemical Co., etc. may also be used.

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

  The content (concentration) of the recording material is, for example, in the range of 2% by mass to 20% by mass with respect to the ink.

  Examples of the volume average particle diameter of the recording material include a range of 10 nm to 300 nm.

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

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

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

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

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

  Other examples of the water-soluble organic solvent include propylene carbonate and ethylene carbonate.

  One or more water-soluble organic solvents may be used. As content of a water-soluble organic solvent, the range of 1 mass% or more and 70 mass% or less is 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 may 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. The hydrophilic / hydrophobic balance (HLB) of the surfactant is, for example, in the range of 3 or more and 20 or less in consideration of solubility.

  The amount of these surfactants added is, for example, in the range of 0.001% by mass to 5% by mass, desirably 0.01% by mass to 3% by mass.

(Ink-receptive 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 stores the ink receptive particles according to the present embodiment, and the ink is applied to the particle coating apparatus (particle supply apparatus) of the recording apparatus. It is a member for supplying receptive particles.

  Hereinafter, an embodiment of an ink receiving particle storage cartridge according to the present 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 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 embodiment includes a cylindrical particle storage cartridge main body 51 and side wall portions 52 fitted to both ends of the particle storage cartridge main body 51. 54.

  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 conveys the ink receiving particles in the particle storage cartridge main body 51 toward the carry-out port 60 while stirring. 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 according to 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 an ink containing a recording material and the ink receiving particles according to the present embodiment, and includes an intermediate transfer member and an ink receiving property. Supply means (supply process) for supplying particles onto the intermediate transfer member, ink discharge means (ink discharge process) for discharging ink onto the ink receiving particles supplied onto the intermediate transfer member, and recording the ink receiving particles A transfer unit (transfer process) for transferring to the medium; and a fixing unit (fixing step) for fixing the ink receiving particles transferred to the recording medium. The ink receiving particles are supplied onto the intermediate transfer member. And a recording apparatus (recording method) for receiving ink ejected from the ink ejecting means.

  Specifically, for example, first, ink receiving particles are supplied in a layer form to an intermediate (intermediate transfer member) by a supply unit. Ink is ejected by the ink ejecting means to the ink receptive particles (hereinafter referred to as ink receptive particle layer) supplied in layers. The ink receiving particle layer that has received the ink is transferred from the intermediate to the recording medium by a transfer means. 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 pressurized (or heated / pressurized) by a fixing means to be fixed. In this way, recording is performed with the ink receiving particles that have received the ink. Note that 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 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, coated paper, etc.) and a non-penetrating medium (for example, art paper, resin film, etc.) are applied. The recording medium is not limited to these, and includes industrial products such as semiconductor substrates.

  On the other hand, the recording apparatus (recording method) according to the present embodiment includes a supplying unit that supplies ink receiving particles onto a recording medium, an ink discharging unit that discharges ink onto the ink receiving particles supplied onto the recording medium, and a recording. And a fixing unit that fixes the ink receiving particles supplied onto the medium, and the ink receiving particles are supplied onto the recording medium and receive the ink discharged from the ink discharging unit ( Recording method).

  Specifically, first, the ink receiving particles are supplied to the recording medium in a layer form by the supplying means. Ink is ejected by the ink ejecting means to the ink receptive particles (hereinafter referred to as ink receptive particle layer) supplied in layers. The ink receiving particle layer that has received ink is pressed (or heated / pressurized) by a fixing means 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.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is provided to the member which has the substantially the same effect | action and function through all the drawings, and the overlapping description may be abbreviate | omitted.

  FIG. 5 is a configuration diagram illustrating the recording apparatus according to the embodiment. FIG. 6 is a configuration diagram illustrating a main part of the recording apparatus according to the embodiment. FIG. 7 is a configuration diagram illustrating an ink receiving particle layer according to the embodiment. In the following embodiments, a case where composite particles are applied as ink receiving particles is described.

  As shown in FIGS. 5 and 6, the recording apparatus 10 according to the 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 charging on the intermediate transfer body 12. A particle supply device 18 for supplying ink receiving particles 16 to the formed area to form a particle layer, an ink jet recording head 20 for forming an image by ejecting ink droplets onto the particle layer, and a recording medium 8 overlapped with the intermediate transfer body 12. In addition, the image forming apparatus includes 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 member 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 positive charge to the surface of the intermediate transfer body 12 by the charging device 28, the surface of the intermediate transfer body 12 is charged with a positive charge. Here, if the ink receiving particles 16 form a potential that can be supplied / adsorbed to the surface of the intermediate transfer body 12 by an electrostatic force due to an electric field that can be formed between the supply roll 18A of the particle supply device 18 and the surface of the intermediate transfer body 12. Good.

  In the present embodiment, a voltage is applied between the charging device 28 and a driven roll 31 (connected to the ground) disposed between the charging device 28 and the intermediate transfer body 12 using the charging device 28, so that the surface of the intermediate transfer body 12 is covered. It is configured to be charged.

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. Give charge. 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 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 supply 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 charging blade 18 </ b> B is disposed so as to press the supply roll 18 </ b> A. The charging blade 18B also has a function of regulating the layer thickness of the ink receiving particles 16 supplied to the surface of the supply roll 18A.

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

  The charged ink receiving particles 16 form, for example, a single particle layer on the surface of the supply roll 18A, and are conveyed to a portion facing the surface of the intermediate transfer body 12. When close to this, the surfaces of the supply roll 18A and the intermediate transfer body 12 are conveyed. The charged ink receiving particles 16 are moved to the surface of the intermediate transfer member 12 by electrostatic force due to the electric field formed by the potential difference between them.

  At this time, the moving speed of the intermediate transfer body 12 and the rotation speed of the supply 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 supply roll 18A and the intermediate transfer member 12.

The number of particles supplied onto the intermediate transfer body 12 is increased by relatively increasing the peripheral speed of the supply roll 18A on the basis of the peripheral speed ratio for forming the one ink receptive particle layer 16A. Let 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. For the heating roll 22A and the pressure roll 22B, the outer surface of the aluminum core is coated with silicone rubber, and further coated with a PFA tube.

  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 the present 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.

  As the recording medium 8, a permeation medium (for example, plain paper or inkjet coated paper) or a non-penetration medium (for example, art paper or resin film) is applicable. 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 according to the present embodiment, as shown in FIG. 6, the release layer 14 </ b> A is formed on the surface of the intermediate transfer body 12 by the release layer 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 supplied by the supply roll 18 </ b> A of the particle supply device 18 are electrostatically adsorbed to form a layer of the ink receiving particles 16 on the surface of the intermediate transfer body 12.

  Next, the ink receiving particles 16 are formed as a layer on the surface of the intermediate transfer body 12 by the supply roll 18 </ b> A 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 receiving particle layer 16A transferred to the recording medium 8 is controlled by controlling the ink receiving particle layer 16A to a desired thickness by the gap between the charging blade 18B and the supply roll 18A as described above. To do. Alternatively, it may be controlled by the peripheral speed ratio between the supply roll 18 </ b> A 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 forms an image on which the recording material (for example, a color material such as pigment) is not exposed.

  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 of the present invention. 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 pressurized by a transfer fixing device (transfer fixing roll) 22, the surface can be flattened, and the glossiness of the image surface is 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.

<Each component>
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 belt-shaped as in the embodiment, or may be cylindrical (drum-shaped). 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 the electrical characteristics of the surface of the intermediate transfer member, in the case of semi-conductivity, the surface resistivity is 10 ¹⁰ Ω / □ or more and 10 ¹⁴ Ω / □ or less, the volume resistivity is 10 ⁹ Ω · cm or more and 10 ¹³ Ω · cm or less, In the case of insulation, a member having a surface resistivity of 10 ¹⁴ Ω / □ or more and a volume resistivity of 10 ¹³ Ω · cm or more is used.

  In the case of a belt shape, the base material can be driven by a belt in the apparatus, has the required mechanical strength, and particularly has the required heat resistance when using heat during transfer / fixing. Good. 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 preferably, for example, from 5 mPa · s to 200 mPa · s, more preferably from 5 mPa · s to 100 mPa · s, and even more preferably from 5 mPa · s to 50 mPa · s.

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

  The surface tension of the release agent 14D is, for example, in the range of 40 mN / m or less (desirably 30 mN / m or less, more desirably 25 mN / m or less).

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

  The boiling point of the release agent 14D is, for example, in the range of 250 ° C. or higher (preferably 300 ° C. or higher, more preferably 350 ° C. or higher) under 760 mmHg.

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

  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 is applied. That is, charges are previously supplied to the surface of the intermediate transfer body 12 by a general electrophotographic charging method (charging by the charging device 28, etc.). The ink receiving particles 16 are triboelectrically charged (one-component triboelectric charging method or two-component method) with a polarity opposite to the charge on the surface of the intermediate transfer member 12.

  The ink receiving particles 16 held on the supply roll 18A form an electric field with the surface of the intermediate transfer body 12, and are moved / supplied onto the intermediate transfer body 12 by electrostatic force and held. 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 desirably 1 μm or more and 100 μm or less, more desirably 1 μm or more and 50 μm or less, and further desirably 5 μm or more and 25 μm or less. Further, the porosity in the ink receptive particle layer (that is, the void ratio between the ink receptive particles + the void ratio in the ink receptive particles (trap structure)) is preferably 10% or more and 80% or less. Is from 30% to 70%, more preferably from 40% to 60%.

  Hereinafter, a particle supply process corresponding to a one-component supply (development) method will be described.

  The ink receiving particles 16 are supplied to the supply roll 18A, the thickness of the particle layer is regulated by the charging blade 18B and charged.

  The charging blade 18B has a function of regulating the layer thickness of the ink receiving particles 16 on the surface of the supply roll 18A. For example, the thickness of the ink receiving particles 16 on the surface of the supply roll 18A is changed by changing the pressure applied to the supply roll 18A. To change. For example, the thickness of the ink receiving particles 16 on the surface of the supply 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 charging blade 18B is controlled to be low, the thickness of the ink receiving particles 16 formed on the surface of the supply roll 18A is increased, and the thickness of the ink receiving particles formed on the surface of the intermediate transfer body 12 is increased. It may be increased.

  As another method, when the peripheral speed of the supply roll 18A that forms, for example, 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 supply roll 18A is increased and the intermediate transfer is performed. The number of ink receiving particles 16 supplied on the body 12 may be increased to control the ink receiving particle layer thickness on the intermediate transfer body 12 to increase. 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 thickness of the ink receptive particle layer in this way, a pattern whose surface is covered with a protective layer is formed while suppressing the consumption of the ink receptive particle layer.

As the 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 the volume resistivity is 10 ⁶ Ω · cm or more 10 A roll having a diameter of 10 mm or more and 25 mm or less adjusted to about ⁸ Ω · cm or less is 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 interparticle voids 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 the interparticle voids 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 inter-particle voids in the ink-receptive particles 16 exhibit a filter effect, trapping a recording material (for example, pigment) on the surface of the ink-receptive particle layer 16A, and trapping in the inter-particle voids in the ink-receptive particles 16 ( It is expressed by being trapped and fixed.

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

  In addition, a line type ink jet recording head having a width equal to or larger than the width of the recording medium is desirable. However, using a conventional scan type ink jet recording head, images are sequentially formed on the particle layer formed on the intermediate transfer member. It may be formed. The ink discharge means of the 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 is used, but a pigment ink is preferable.

  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 by the charging device 28. Is charged. 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 showing 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 to be 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 100 (hereinafter abbreviated as “electrostatic recording head 100”) controls a recording medium 8 being transported by the transport belt 13 to control the ion flow due to discharge. An electrostatic latent image is formed by irradiating on the surface 8. (See FIG. 10A).

  The electrostatic receptive image formed on the recording medium 8 is visualized by the ink receptive particle supply device 18 to form an ink receptive particle layer 16A 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 100 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 attracted 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 100 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 100, a plurality of drive electrodes 104 are provided in parallel to each other on the surface of a flat rectangular insulating substrate 102, and a plurality of controls are provided on the back surface thereof so as to intersect with these drive electrodes 104. An electrode 106 is provided. The drive electrode 104 and the control electrode 106 form a matrix (lattice). The control electrode 106 is formed with a circular opening 106 </ b> A at a position intersecting with the drive electrode 104. A screen electrode 108 is provided on the lower surface of the control electrode 106 with an insulating substrate 101 interposed therebetween. In the insulating substrate 101 and the screen electrode 108, a space 111 and an ion derivation opening 110 are formed at a position corresponding to the opening 106A of the control electrode 106.

  A high frequency high voltage is applied between the drive electrode 104 and the screen electrode 108 by the AC power source 112. On the other hand, a pulse voltage corresponding to image information is applied to the control electrode 106 by an ion control power source 114. Further, a DC voltage is applied to the screen electrode 108 by a DC power source 116.

  Then, by applying an alternating electric field between the drive electrode 104 and the control electrode 106 thus insulated, a creeping corona discharge is induced in the space 111, and ions generated by the creeping corona discharge are caused to flow between the control electrode 106 and the control electrode 106. Acceleration or absorption by an electric field formed between the screen electrode 108 and the ion flow from the ion extraction opening 110 is controlled, and ions corresponding to an image signal (ink image) (in this embodiment) An electrostatic latent image (see FIG. 10A) is formed on the surface of the recording medium 8 by using positive ions.

  In the next step, the potential of the electrostatic latent image is determined by the electrostatic force generated by the electric field formed by the particle supply roll 18A of the ink receiving particle supply device 18 and the electrostatic latent image formed on the recording medium 8. 16 may be any potential that can be supplied / adsorbed to the recording medium 8.

  The electrostatic recording head 100 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 ink receiving particle supply device 18 to visualize the electrostatic latent image, and the ink receiving particle layer 16A corresponding to the electrostatic latent image is formed. Form. (See FIG. 10B). Thereby, the ink receptive particle layer 16A is formed on the recording medium 8 only in the ink image region formed based on the image signal (the ink receptive particle layer 16A is almost formed in the non-image portion region). Not)

  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 is desirable as in the present embodiment, but an image may be sequentially formed 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 the same as that of a fixing device (fuser) used in an electrophotographic image forming apparatus. Furthermore, a heater heating method, an oven method, an electromagnetic induction heating method, and the like can be used in addition to the heating and fixing device used in the electrophotographic image forming apparatus.

  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 100 while the recording medium 8 is conveyed by the conveying belt 13, and a particle supply device is applied to the electrostatic latent image. The ink receiving particles 16 are supplied from 18 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-described 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 based on the image data from the inkjet recording heads 20 of black, yellow, magenta, and cyan so that a full color image is recorded on the recording medium 8. However, embodiments of the present invention are not limited to recording characters and images on a recording medium. That is, the droplet discharge device according to the embodiment of the present invention is applied to all the droplet discharge (ejection) devices used industrially.

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

[Example A]
As the hydrophilic resin, a styrene / n-butyl methacrylate / acrylic acid copolymer (weight average molecular weight Mw = 40000, monomer ratio having carboxylic acid group = 40 mol%) was prepared.

  10 parts by weight of the hydrophilic resin is dissolved by adding a mixed solvent (dissolving solvent) of 20 parts by weight of isopropyl alcohol (IPA) and 5 parts by weight of ethyl ethyl ketone (MEK), and then the pH is 6.7. A 10% by mass aqueous sodium hydroxide solution (NaOH aq.) Was added as a neutralizing agent to prepare a resin solution.

  Water was added to the obtained resin solution while keeping it at 50 ° C., and after emulsification with an ultrasonic homogenizer, it was naturally cooled to room temperature (25 ° C.) to obtain an emulsion liquid having a resin solid content concentration of 10% by mass. It was.

  Thereafter, the obtained emulsion liquid was spray-dried (product name BUCHI, mini-spray dryer B290, spray drying conditions: used spray gun caliber 1.5 mm, inlet temperature 125 ° C., aspirator setting 100%, pump Spray drying was performed at a setting of 25% and an outlet temperature of 60 ° C. to obtain ink receiving particles.

[Examples B to G]
Ink-receptive particles were obtained in the same manner as in Example A except that the material type and operation used were changed according to Table 1.
However, in Examples D, E, and G, the emulsion liquid was freeze-dried (freeze-dried), and the obtained solid was pulverized / classified to obtain ink receiving particles.

[Comparative Example A]
First, the same hydrophilic resin as in Example A was prepared. 10 parts by mass of the hydrophilic resin is dissolved by adding a mixed solvent (dissolving solvent) of 20 parts by mass of isopropyl alcohol (IPA) and 5 parts by mass of tilethyl ketone (MEK), and then water is kept at 70 ° C. In addition, the emulsion was emulsified with an ultrasonic homogenizer to obtain an emulsion having a resin solid content concentration of 10% by mass.

  While maintaining the obtained emulsion at 50 ° C., a 10% by mass sodium hydroxide aqueous solution (NaOH aq.) Was added as a neutralizing agent until the pH reached 7.1, and the emulsification treatment was continued with an ultrasonic homogenizer. The mixture was naturally cooled to room temperature (25 ° C.) to obtain an emulsion.

  Thereafter, the obtained emulsion liquid was spray-dried (product name BUCHI, mini-spray dryer B290, spray drying conditions: used spray gun caliber 1.5 mm, inlet temperature 125 ° C., aspirator setting 100%, pump Spray drying was performed at a setting of 25% and an outlet temperature of 60 ° C. to obtain ink receiving particles.

[Comparative Example B]
First, the same hydrophilic resin as in Example A was prepared. 10 parts by weight of the hydrophilic resin was added to 90 parts by weight of water while keeping the temperature at 70 ° C., and 10% by weight sodium hydroxide aqueous solution (NaOH aq.) Was added as a neutralizing agent until pH 13.0. After stirring with a sonic homogenizer, it was naturally cooled to room temperature (25 ° C.) to obtain a resin solution (resin solid content concentration of about 10% by mass).

  Thereafter, the obtained emulsion liquid was spray-dried (product name BUCHI, mini-spray dryer B290, spray drying conditions: used spray gun caliber 1.5 mm, inlet temperature 125 ° C., aspirator setting 100%, pump The ink receiving particles were obtained by spray drying at a setting of 25% and an outlet temperature of 60 ° C.

[Evaluation]
According to Tables 1 and 2, the following evaluation was performed using each of the above particles (ink receiving particles) and the following ink. The results are shown in Tables 1 and 2.

(Preparation of ink)
The following ink components were mixed, stirred, and then filtered using a membrane filter having a pore size of 5 μm to prepare an ink.
・ C. I. Pigment Blue 15: 3: 7% by mass
-Styrene-acrylic acid copolymer: 2.5% by mass
・ Glycerin: 10% by mass
Propylene glycol: 10% by mass
・ 1,2-hexanediol: 5% by mass
・ Orphine E1010 (manufactured by Nissin Chemical): 1.5% by mass
-NaOH: appropriate amount-water: remainder The pH of the ink obtained was adjusted with an aqueous sodium hydroxide solution to 8.5. The surface tension of the ink was 31 mN / m.

(Evaluation)
-Particle properties-
For each particle, the average particle diameter in terms of a sphere is measured with a laser diffraction particle size distribution analyzer (LA-700, manufactured by Horiba, Ltd.) and at the same time, with an SEM (Scanning Electron Microscope; magnification 5000 times). Shape observation was performed. Further, when the particle shape is composite particles, the sphere-converted average particle size of the primary particles constituting the particle is selected as an average value by randomly selecting 100 primary particles from the SEM observation image.

-Determination of dissolution / insolubility of particles and amount of functional groups-
The amount of functional groups was measured according to the above. At that time, the dissolution / insolubility of the particles was also determined. 100 g of a mixed solvent of isopropyl alcohol (IPA) and water (mixing ratio: range of 65/35 to 45/55) is added to 0.5 g of each particle, followed by stirring with a stirrer at 25 ° C. for 10 minutes. After standing, the presence or absence of a residue was visually observed, the liquid color was colorless and transparent, and the residue was not dissolved, and the solution was judged to be insoluble when the solution was cloudy white or the residue was seen .
However, the IPA / water mixed solution used had the following mass ratio for each particle.
Example A: IPA / water = 50/50 (SP value 20.7)
Example B: IPA / water = 60/40 (SP value 19.7)
Example C: IPA / water = 65/35 (SP value 19.2)
Example D: IPA / water = 45/55 (SP value 21.1)
Example E: IPA / water = 50/50 (SP value 20.7)
Example F: IPA / water = 50/50 (SP value 20.7)
Example G: IPA / water = 50/50 (SP value 20.7)

In Comparative Examples A and B, a residue was found in the IPA / water mixed solution having a mixing ratio in the range of 65/35 to 45/55, and it was determined that the mixture was insoluble.
The IPA / water mixed solution used for measuring the functional group amount of the dissolved component is as follows.
Comparative Example A: IPA / water = 45/55 (SP value 21.1)
Comparative Example B: IPA / water = 65/35 (SP value 19.2)
In addition, when the particle shape was composite particles, the functional group amount was measured for the primary particles constituting the composite particles.

-Absorption amount-
Disperse the particles onto an intermediate medium (PET film) using a cake printer (particle application amount: 5 to 12 g / m ² ), and use a piezo-type ink jet device to apply ink onto the intermediate medium onto which the particles have been applied. (4.5 g / m ² ) to form a solid image (1200 dpi × 1200 dpi (dpi: dots per inch), 100% coverage pattern), and image 0.3 seconds later The amount of ink transferred to the roller was measured when a roller (elastic layer made of silicone rubber on the surface of a metal cylindrical core metal) was pressed against the portion with a load of 2 × 10 ⁴ Pa. The evaluation criteria are as follows.
◎: No print transfer occurred in the enlarged image ○: Enlarged image print transfer occurred, but it was not visually discernable, and within an allowable range Δ: The print shift could be discriminated as a whole by visual inspection Although it is within the allowable range x: The printing shift can be visually discerned and is outside the allowable range

-Image stickiness-
In the same manner as described above, after particles are dispersed on an intermediate medium (PET film) (particle application amount: 5 to 12 g / m ² ), ink is applied onto the intermediate medium on which the particles are dispersed using a piezo-type ink jet device. (4.5 g / m ² ) to form a solid image (1200 dpi × 1200 dpi (dpi: dots per inch), 100% coverage pattern), press the art paper, and then heat / Transfer processing was performed to obtain an image. This image was stored in an environment of 30 ° C. and 80% RH, stored for 1 week, and then touched with a finger to evaluate the stickiness of the image. The evaluation criteria are as follows.
○: No stickiness even when pressed with a finger, and no disturbance occurs in the image.
Δ: When pressed with a finger, there is a slight stickiness, but the image is not disturbed.
X: When pressed with a finger, there is a sticky feeling, and the image adheres to the finger and is disturbed.

-Image water resistance-
In the same manner as described above, after particles are dispersed on an intermediate medium (PET film) (particle application amount: 5 to 12 g / m ² ), ink is applied onto the intermediate medium on which the particles are dispersed using a piezo-type ink jet device. Application (4.5 g / m ² ) to form a line image of 1 dot line (1200 dpi × 1200 dpi (dpi: dots per inch), 100% coverage pattern), and press-contact art paper After that, heating / transfer treatment was performed to obtain an image. With respect to this line image, water was dropped with a dropper (20 g / m ² ), and the line image after 1 hour was observed.
(Double-circle): Disturbance of an image is not seen about both visual observation and an enlarged image (25 times).
○: Image distortion is observed in the enlarged image (25 times), but cannot be visually recognized. Δ: Image distortion is observed in the enlarged image (25 times), and part of the image can be determined visually. In both the enlarged image and the magnified image (25 times), image distortion is observed.

  From the above results, it can be seen that, in this example, both the liquid absorption amount and the image storage (water resistance and image stickiness) properties are excellent and the compatibility is realized as compared with the comparative example.

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 18 Ink receiving particle supply device 18A Particle supply roll 18B Charging blade 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 Neutralizing 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 Coupling Part 66 connecting portion 68 agitator

Claims (6)

It is comprised including a hydrophilic resin having at least one kind of acidic functional group, and the amount of the acidic functional group per 1 g of the particles is 1.4 × 10 ⁻³ mol / g or more and 4.0 × 10 ⁻³ mol / g. Ink-receptive particles having hydrophilic particles that are soluble in a mixed solvent of isopropyl alcohol and water in which the particles are mixed at a ratio in a predetermined range.   The ink receiving particles according to claim 1, comprising composite particles in which the hydrophilic particles are gathered. An intermediate transfer member;
Supply means for supplying the ink receiving particles according to claim 1 or 2 onto the intermediate transfer member;
An ink ejection means for ejecting ink to the ink receiving particles supplied onto the intermediate transfer member;
Transfer means for transferring the ink receiving particles to a recording medium;
Fixing means for fixing the ink receiving particles transferred to the recording medium;
A recording apparatus. Supply means for supplying the ink receiving particles according to claim 1 or 2 onto a recording medium;
Ink ejection means for ejecting ink onto the ink receiving particles supplied on the recording medium;
Fixing means for fixing the ink receiving particles supplied on the recording medium;
A recording apparatus.   A recording material comprising ink and the ink receiving particles according to claim 1.   An ink receptive particle storage cartridge which is detached from the recording apparatus and stores the ink receptive particles according to claim 1.