JP2007175978A - Ink acceptable particle, marking material, ink accepting method, recording method, recording device and ink acceptable particle housing cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide ink acceptable particles, marking material, an ink accepting method, a recording method, a recording device and an ink acceptable particle housing cartridge, with which high speed recording is possible to diverse recording media even employing various inks. <P>SOLUTION: This ink acceptable particle accepts ink and includes organic resin particles having at least voids (organic porous particles). The ink acceptable paricle may well be composed of the primary particle of the organic resin particle or of a composite particle 100, which may well be an aggregate of organic resin particles having at least voids (organic porous particles 102). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to ink receptive particles for receiving ink and transferring it to a recording medium, for example, for recording an image or data. The present invention also relates to a marking material, an ink receiving method, a recording method, a recording apparatus, and an ink receiving particle storage cartridge using the ink receiving particles.

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

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

  For example, Japanese Patent Laid-Open No. 2000-343808 proposes a method for recording while supplying a plurality of powder mixtures onto an intermediate, such as polymers having different water absorption, water absorption polymers having different sizes, water absorption polymers having different degrees of crosslinking, and the like. Has been.

  Japanese Patent Laid-Open No. 2000-94654 proposes a method of recording while supplying solid particles (particles of polysaccharide polymer, alginic acid, carrageenan, etc.) that thicken the ink by contact with the ink on the intermediate. Yes.

  Japanese Patent Application Laid-Open No. 2003-57967 discloses that a hydrophobic resin particle layer is formed on an intermediate body, and ink (for example, an SD type dye ink slow dry type (Slow Dry type)) is held in the voids of the hydrophobic resin particle layer. Then, a method of transferring to a recording medium has been proposed.

  Japanese Patent Laid-Open No. 2002-370347 discloses a method in which a void-type ink absorbing layer in which an intermediate (sheet) is coated with inorganic particles, a hydrophilic polymer, and the like is provided wet, and dye ink is ejected there and transferred to a recording medium. Has been proposed.

Further, JP-A No. 2002-321443 discloses an inkjet intermediate transfer having a porous ink absorbing layer that is formed by drying at a temperature equal to or lower than the MFT of thermoplastic resin particles, including thermoplastic resin particles and non-thermoplastic particles. A medium has been proposed.
JP 2000-343808 JP 2000-94654 A JP 2003-57967 A JP 2002-370347 JP 2002-321443 A

  However, with the above proposal, it is possible to record on a variety of recording media with high image quality, but the current demand for high-speed recording is still insufficient, and improvement is hoped for. It is rare.

  In view of the above problems, the present invention is to provide ink-receptive particles that can be recorded on various recording media at high speed even when various inks are used. Another object of the present invention is to provide an ink receiving particle, a marking material, an ink receiving method, a recording method, a recording apparatus, and an ink receiving particle storage cartridge using the ink receiving particle.

The above problem is solved by the following means. That is,
The ink receiving particles of the present invention are ink receiving particles that receive ink,
It is characterized by containing at least organic resin particles having voids.

  In the ink receiving particles of the present invention, the organic resin particles having the voids are preferably organic resin porous particles.

  In the ink receiving particles of the present invention, the ink receiving particles are preferably at least composite particles in which the organic resin particles having voids are aggregated.

  The composite particles may be composite particles in which organic resin non-porous particles and / or inorganic non-porous particles are aggregated in addition to the organic resin particles having voids.

  Moreover, it is preferable that the gap between the particles constituting the composite particles is 0.1 to 5 μm in maximum diameter.

  The marking material of the present invention is characterized by comprising ink and the ink receiving particles of the present invention.

The ink receiving method of the present invention is a method of receiving ink in the ink receiving particles of the present invention,
A trapping step for trapping at least a liquid component of the ink is provided in a gap between the organic resin particles having the voids in the composite particles.

Moreover, the recording method of the present invention comprises:
A recording method using an ink and the ink receiving particles of the present invention,
Receiving the ink in ink receiving particles;
Transferring the ink receiving particles that have received the ink to a recording medium;
It is characterized by having.

  The recording method of the present invention may further include a step of fixing the ink receiving particles transferred onto the recording medium.

The recording apparatus of the present invention
A recording apparatus using ink and the ink receiving particles of the present invention,
Discharging means for receiving the ink in ink receiving particles;
Transfer means for transferring the ink receiving particles that have received the ink to a recording medium;
It is characterized by having.

  The recording apparatus of the present invention may further include a fixing unit that fixes the ink receiving particles transferred onto the recording medium.

  The ink receptive particle storage cartridge of the present invention is detachably disposed in a recording apparatus and stores the ink receptive particles of the present invention.

  According to the present invention, it is possible to provide ink receptive particles that can be recorded on various recording media at a high speed even when various inks are used. In addition, the present invention can provide an ink receiving particle, a marking material, an ink receiving method, a recording method, a recording apparatus, and an ink receiving particle storage cartridge using the ink receiving particle.

  Hereinafter, the present invention will be described in detail.

(Ink-receptive particles)
The ink receiving particles of the present invention receive ink. Here, the ink receptivity indicates that at least a part (at least a liquid component) of the ink component is retained. The ink receiving particles of the present invention include organic resin particles having voids (hereinafter sometimes referred to as void-containing organic resin particles).

  The ink receptive particles of the present invention may be single particles (primary particles) containing void-containing organic resin particles, or may be composite particles in which at least void-containing organic resin particles are aggregated. Therefore, the composite particle is preferable.

  In the case where the ink receiving particles of the present invention are particles containing only void-containing organic resin particles, when the ink receiving particles receive ink (ink receiving method), if the ink adheres to the ink receiving particles, at least the ink liquid The ink liquid component is captured (trapped) by the voids of the organic resin particles containing voids. For this reason, the liquid absorption speed is faster than before, and the ability to retain the liquid component of the absorbed ink is improved.

  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. Therefore, even if various inks are used, it is possible to record on various recording media at high speed.

  On the other hand, when the ink receiving particles of the present invention are composite particles containing at least void-containing organic resin particles, when the ink receiving particles receive ink (ink receiving method), first, the ink becomes the ink receiving particles. When attached, at least the liquid component of the ink is trapped by a gap between particles (at least void-containing organic resin particles) constituting the composite particle (hereinafter, the interparticle gap (void) may be referred to as a trap structure). At this time, the recording material among the ink components is attached to the surface of the ink receiving particles or trapped by a trap structure regardless of pigments or dyes. 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.

  Since the ink liquid component trap by this trap structure is trapped by the physical particle wall structure, the liquid absorption speed is high and the drying time is shortened. For this reason, the ink receptive particles that have received the ink can be transferred to various recording media in a short time regardless of the permeation medium or the non-penetration medium.

  Then, by applying composite particles in which at least void-containing organic resin particles are aggregated as ink receiving particles, trapping by traps (physical particle wall structure) between the particles constituting the composite particles is performed. In addition, since the ink liquid component is captured (trapped) by the voids of the void-containing organic resin particles as described above, the liquid absorption speed is faster than before and the liquid component retention capacity of the absorbed ink is improved. To do.

  Therefore, even if various inks are used, it is possible to record on various recording media at high speed.

  In the ink receptive particles of the present invention, when a liquid absorbent resin or a porous material is applied to the particles constituting the ink receptive particles, the liquid component of the trapped ink is changed by the liquid absorbent resin or the porous material. Absorbed and retained. For this reason, the holding stability is further improved, and even when a physical force is applied to the ink receiving particles that have received the ink during transfer, the liquid component does not leak and bleeding does not occur.

  In addition, since the ink receiving particles are transferred to the recording medium in a state where the liquid component of the ink is completely trapped, the recording medium strength is prevented from being curled or curled by the recording medium, and further, due to liquid absorption.

  In addition, after the transfer of the ink receiving particles, the organic resin component constituting the ink receiving particles functions as a binder resin or a coating resin for the recording material contained in the ink. (Rubbing property) is also improved, and gloss control of recorded matter is also possible. Further, when the ink receiving particles are composite particles, the recording material is trapped in the trap structure, so that high color development can be obtained regardless of whether the recording material is a pigment or a dye. In particular, by applying a transparent resin as the organic resin component constituting the ink receiving particles, higher color development can be obtained.

  In order to improve the fixability (rubbing resistance) of an ink (for example, pigment ink) using an insoluble component such as a pigment or a dispersed particulate material as a recording material, it is necessary to add a large amount of polymer to the ink. If a large amount of polymer is added to the processing liquid (including the treatment liquid), the reliability such as nozzle clogging of the ink discharge means is deteriorated. On the other hand, in the present invention, since the organic resin component constituting the ink receptive particles fulfills the function of the polymer, it is possible to achieve both high image quality and high fixing and high system reliability.

  Here, the “gap between particles constituting the composite particle”, that is, the “trap structure” is a physical particle wall structure capable of holding at least a liquid. The size of the gap is preferably 0.1 to 5 [mu] m, more preferably 0.3 to 1 [mu] m in terms of the maximum aperture. In particular, the size of the gap is preferably a size that can trap a recording material, particularly, for example, a pigment having a volume average particle diameter of 100 nm. Micropores having a maximum opening diameter of less than 50 nm may exist simultaneously. Further, from the viewpoint of improving the liquid absorbency, the voids and capillaries are preferably communicated inside the particles.

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

  As described above, the trap structure preferably traps not only the liquid component of the ink components but also the recording material. When the recording material, in particular the pigment, is trapped in the trap structure together with the ink liquid component, that is, the recording material is held and fixed without being unevenly distributed in the ink receiving particles, so that both high speed recording and high image quality can be achieved. The liquid component of the ink is mainly an ink solvent or a dispersion medium (vehicle liquid).

  The “organic resin particles having voids” are those having irregularities on the surface and having void structures on the particle surface due to the irregularities. Particularly preferred as organic resin particles having voids are porous particles.

The maximum opening diameter of the organic resin particles having voids is preferably 30 to 1000 nm. More preferably, it is 50-750 nm, More preferably, it is 100-600 nm. On the other hand, the specific surface area is preferably 1 to 750 m ² / g in terms of BET specific surface area (N ₂ ), more preferably 5 to 600 m ² / g, and still more preferably 10 to 400 m ² / g.

  Here, the measuring method of the maximum opening diameter is obtained as follows. The maximum aperture diameter was determined by reading a scanning electron microscope (SEM) image of the particle surface with an image analyzer, detecting the gap by binarization processing, and analyzing the size and distribution of the gap.

Measurement method of BET specific surface area _{(N 2)} is obtained as follows. The BET specific surface area (N ₂ ) was measured using a beta soap automatic surface area meter (MODEL 4200, manufactured by Nikkiso Co., Ltd.).

  The organic resin particles (porous particles) having voids can be obtained by a known method. Specifically, phase separation methods (microphase separation, cross-linking copolymerization (phase separation simultaneously with cross-linking polymerization), cross-linking copolymerization (styrene-divinylbenzene)), extraction method (polymer addition (polyvinyl acetate), polymer) Addition (polystyrene), chemical treatment (macronet method, post-crosslinking method), fusion method (particle fusion), composite method (emulsion technology, multistage polymerization method), other methods (conductive polymer method, electronic (Line irradiation method, radiation irradiation method) and the like. These manufacturing methods are described in “http://www.jpo.go.jp/shiryou/s_sonota/hyoujun_gijutsu/organicpolymer/mokuji.htm” (Japan Patent Office homepage, Standard Technology Collection: Organic Polymer Porous Materials) The details are described.

  It can also be obtained in accordance with, for example, “a new generation of porous materials and their applications—new materials made by nanoscience” (supervision: Susumu Kitagawa: CMMC Publishing: Chapter 1, Section 3).

  The ink receptive particles of the present invention may be composed solely of void-containing organic tree particles (that is, configured to be used as primary particles) without being combined as described above, or may be combined and applied as composite particles. be able to. When the ink receiving particles are composed of composite particles, the composite particles in which organic resin porous particles 102 (organic resin particles having voids) are aggregated as shown in FIG. 100 is preferred. Further, the non-receptive particles of the present invention are preferably composite particles 100 in which nonporous particles 104 are aggregated in addition to organic resin porous particles 102 as shown in FIG. In these composite particles, a void structure is formed by a gap between the particles.

  The nonporous particles may be either organic resin particles or inorganic particles. When organic resin particles are applied as non-porous particles, higher fixability can be imparted, and when liquid absorbent resin particles are applied as organic resin particles, higher liquid absorbency can be imparted. On the other hand, when inorganic particles are applied as non-porous particles, various functions such as charging and conductivity can be imparted in addition to the liquid absorbency.

  Here, the weight ratio between the organic resin particles having pores (organic resin porous particles) and the nonporous particles (organic resin porous particles: nonporous particles) is determined when the nonporous particles are inorganic particles. It is preferably within the range of 5: 1 to 1:10, more preferably within the range of 3: 1 to 1: 5, and even more preferably within the range of 2: 1 to 1: 3. By setting it within the above range, both high-speed drying properties and fixing properties can be achieved. This is considered that high-speed drying is achieved by the penetration of the liquid into the voids in the porous resin fine particles and the voids between the particles. On the other hand, the fixability depends on the ratio of the organic resin, and as the organic resin ratio increases, the fixability tends to be more advantageous.

  On the other hand, when the nonporous particles are organic resin particles, it is preferably within the range of 10: 1 to 1: 5, more preferably within the range of 5: 1 to 1: 3, and even more preferably 3: 1. Within the range of 1: 2. By setting it within the above range, both high-speed drying properties and fixing properties can be achieved. This is considered that high-speed drying is achieved by the penetration of the liquid into the voids in the porous resin fine particles and the voids between the particles. On the other hand, the fixability depends on the ratio of the organic resin, and as the organic resin ratio increases, the fixability tends to be more advantageous.

  In addition, the particle diameter of the organic resin particles (porous and nonporous particles) in the composite particles is preferably 50 nm to 10 μm, more preferably 0.1 μm to 5 μm, and still more preferably 0.2 μm to 0.5 μm in volume average particle diameter. 2 μm. The particle diameter of the inorganic particles (porous and nonporous particles) in the composite particles is 10 nm to 30 μm, preferably 50 nm to 10 μm, more preferably 0.1 μm to 5 μm in volume average particle diameter. The organic resin particles and the porous particles may be primary particles or an aggregate obtained by granulating the primary particles.

  These 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, a part of the particles may be dissociated, that is, the composite particles may be disassembled and the particles constituting the composite particles may be scattered.

  The ink receptive particles of the present invention are not limited to the above-described configuration, and may be composite particles containing at least organic resin particles having voids. For example, organic resin particles having voids (for example, organic resin porous material) Composite particles including particles) and inorganic particles having voids (for example, inorganic porous particles) may be used.

  As for the particle size of the ink receiving particles of the present invention, the average particle size in terms of sphere (average particle size in terms of sphere) is preferably 0.1 to 50 μm, more preferably 0.5 μm to 25 μm, and even more preferably 1 μm. 10 μm. High image quality is achieved within the above range. That is, when the average particle size is large, a step in the height direction is generated between the portion where the particles exist and the portion where the particles do not exist on the image surface, which may result in poor image smoothness. On the other hand, when the 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 no liquid-absorbing particles exist 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 of the volume average particle diameter.

  Here, the average particle diameter in terms of sphere is determined as follows. Although the optimum method differs depending on the particle size, various methods can be used such as, for example, dispersing particles in a liquid and obtaining the particle size by the light scattering principle, and obtaining a projected image of the particles by image processing. Examples of methods that can be used for general purposes include the Microtrac UPA method and the Coulter counter method.

The ink receiving particles of the present invention preferably have a BET specific surface area (N ₂ ) of 1 to 750 m ² / g, more preferably 5 to 600 m ² / g, and still more preferably 10 to 400 m ² / g. is there. Within the above range, high-speed drying tends to be excellent. This is presumed that the particles satisfying the characteristics in this range have sufficient voids in the particles and between the particles, and the liquid can be trapped at high speed in the voids.

The ink receiving particles of the present invention preferably have a BET specific surface area (CO ₂ ) / BET specific surface area (N ₂ ) value of 1 to 50, more preferably 1 to 40, still more preferably. 5-30. Within the above range, high-speed drying tends to be excellent. This is because particles satisfying this property are made hydrophilic because the particle surface becomes hydrophilic, and the liquid trap speed can be increased from the viewpoint of wettability of the particle surface.

Here, the BET specific surface area (N ₂ ) was measured using a beta soap automatic surface area meter (MODEL 4200, manufactured by Nikkiso Co., Ltd.).

The BET specific surface area (CO ₂ ) was measured using a beta soap automatic surface area meter (MODEL 4200, manufactured by Nikkiso Co., Ltd.).

  Next, the organic resin particles constituting the porous particles and the nonporous particles will be described. The organic resin particles may be configured to include either a non-absorbing resin or a liquid absorbing resin.

  Hereinafter, the non-liquid absorbing resin will be described. Examples of the non-liquid-absorbing resin include hydrophobic monomers alone or plural kinds of copolymers. Hydrophobic monomers include olefin compounds such as ethylene, propylene and butadiene, styrene derivatives such as styrene, α-methylstyrene, α-ethylstyrene and vinyltoluene, methyl methacrylate, ethyl methacrylate, butyl methacrylate, acrylonitrile, acetic acid Vinyl, methyl acrylate, ethyl acrylate, butyl acrylate, lauryl methacrylate, vinyl cyclohexane, vinyl naphthalene, vinyl naphthalene derivatives, acrylic acid alkyl ester, acrylic acid phenyl ester, methacrylic acid alkyl ester, methacrylic acid phenyl ester, methacrylic acid Examples include cycloalkyl esters, crotonic acid alkyl esters, itaconic acid dialkyl esters, and maleic acid dialkyl esters.

  The non-liquid-absorbing resin refers to a material having a solubility of 3% by mass or less when the single resin is added to a liquid (ink).

  Hereinafter, the liquid absorbent resin will be described. The liquid-absorbing resin softens and improves the fixability because the ink liquid component (for example, water or an aqueous solvent) that has absorbed acts as a plasticizer for the resin (polymer).

  For this reason, the ink receiving particles can be transferred (fixed) to plain paper as a recording medium only by pressurization (however, heating and pressurization are effective for increasing the gloss of the recorded matter). . On the other hand, if the liquid is excessively swelled to cause high swelling, bleeding occurs and the fixability is deteriorated. Therefore, the liquid absorbent resin is preferably a weak liquid absorbent resin. For example, when absorbing water as a liquid, the weak liquid-absorbent resin absorbs several percent (≈5%) to several hundred percent (≈500%), preferably about 5% to 100% of the resin mass. It means a lyophilic resin capable of liquid.

  Here, when the liquid absorbency is less than about 5%, the liquid trapped in the gap may easily overflow from the gap during transfer (or fixing), or the image may be deteriorated. In addition, since the plasticization of the resin is insufficient, high energy is required for fixing. On the other hand, if the liquid absorption capacity is too high, not only the liquid absorption but also the moisture absorption is active, so that the environmental dependency of the handling of the ink receiving particles becomes large and it may be difficult to use. For example, it is possible to prevent the particles from fusing together even if the resin is highly crosslinked and absorbs moisture (for example, a commercially available water-absorbing resin). However, in that case, fixing to the recording medium becomes difficult. In the case of a weak liquid-absorbing resin, the liquid absorption speed of the resin itself is naturally slower than that of a strong liquid-absorbing resin, so that the ink is received in the form of initially trapping the liquid in a void structure and then absorbing the liquid into the resin. Designing the structure and physical properties of the particles is an important point.

  From such a viewpoint, the liquid-absorbing resin can be composed of, for example, a hydrophilic monomer homopolymer or a copolymer composed of both monomers of a hydrophilic monomer and a hydrophobic monomer. In order to obtain a functional resin, the copolymer is preferable. Not only the monomer but also a graft copolymer or block copolymer in which other units such as a polymer / oligomer structure are copolymerized as a start may be used.

Here, as the hydrophilic monomer, -OH, -EO unit (ethylene oxide group), -COOM (M is an alkali metal such as hydrogen, Na, Li, K, ammonia, organic amines, etc.), 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, phenyl, etc..), - NR ₄ And monomers including X (R is, for example, H, alkyl, phenyl and the like, and X is, for example, halogen, sulfate, acid anions such as carboxylic acid, BF ₄ , etc.). Specific examples include 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, acrylamide, acrylic acid, methacrylic acid, unsaturated carboxylic acid, crotonic acid, maleic acid, and the like. Examples of hydrophilic units or monomers include cellulose derivatives such as cellulose, ethyl cellulose, carboxymethyl cellulose, starch derivatives, monosaccharide / polysaccharide derivatives, vinyl sulfonic acid, styrene sulfonic acid, acrylic acid, methacrylic acid, (anhydrous) maleic acid. Polymerizable carboxylic acids such as these, (partially) neutralized salts thereof, vinyl alcohols, vinyl pyrrolidone, vinyl pyridine, derivatives such as amino (meth) acrylate and dimethylamino (meth) acrylate, and further onium salts thereof, Amides such as acrylamide and isopropylacrylamide, vinyl compounds containing polyethylene oxide chains, vinyl compounds containing hydroxyl groups, polyesters composed of polyfunctional carboxylic acids and polyhydric alcohols, especially trimellitic acid Trifunctional or more acid containing as a constituent component branched polyester containing many terminal carboxylic acid or hydroxyl, polyesters including polyethylene glycol structure, etc. may be mentioned.

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

  Specific examples of the liquid-absorbing resin comprising a copolymer of such a hydrophilic monomer and a hydrophobic monomer include (meth) acrylic acid esters, styrene / (meth) acrylic acid / (anhydrous) maleate. Preferable examples include acids copolymers, olefin polymers such as ethylene / propylene (or modified products thereof, or introduced carboxylic acid units by copolymerization), branched polyesters improved in acid value with trimellitic acid, polyamides, and the like. .

  The liquid absorbent resin preferably contains a neutralized salt structure (such as carboxylic acid). This neutralized salt structure such as carboxylic acid forms an ionomer by the interaction with the cation when ink containing a cation (for example, a monovalent metal cation such as Na or Li) is absorbed, and the final recorded matter Fixing strength is improved. Further, the neutralized salt structure such as carboxylic acid promotes the aggregation of the recording material having an anion group (for example, pigment or dye), so that the image quality is also improved.

  The liquid absorbent resin preferably contains a substituted or unsubstituted amino group or a substituted or unsubstituted pyridine group. Since the group exerts a bactericidal effect and an interaction with a recording material (for example, pigment or dye) having an anionic group, image quality and fixability are improved.

  Here, in the liquid absorbent resin, the molar ratio of the hydrophilic unit (hydrophilic monomer) to the hydrophobic unit (hydrophilic monomer) (hydrophilic monomer: hydrophobic monomer) is preferably 5:95 to 70:30. More preferably, it is 7: 93-60: 40, More preferably, it is 10: 90-50: 50. In particular, the hydrophilic unit is preferably 5 to 70 mol%, more preferably 10 to 50 mol%, based on the whole. By setting the hydrophilic monomer within the above range, the water absorption speed is improved when the ink receptive particles absorb an aqueous liquid, the water absorption is improved, and the receptive particles are handled in a high and low humidity environment. The balance of fixing ability can be established.

  Hereinafter, common characteristics of the non-liquid-absorbing resin and the liquid-absorbing resin (hereinafter collectively referred to as organic resin) will be described.

  The organic resin may have a straight chain structure, but a split structure. The organic resin is preferably non-crosslinked or low crosslinked. The organic resin may be a linear random copolymer or block copolymer, but branched polymers (including branched random copolymers, block copolymers, and graft copolymers) are further included. It can be used suitably. For example, in the case of polyester synthesized by polycondensation, increasing the terminal group in a branched structure makes it easy to extend the control latitude of hydrophilicity, water absorption, particle handling and fixing properties. Regardless of whether it is an addition polymerization system or a polycondensation system, for example, if a carboxylic acid group is arranged at the branch portion, a cation is supplied from the ink, so that it is easy to finally form an ion-crosslinking-type strong fixed image. Such a branched structure is synthesized by adding a small amount of a so-called crosslinking agent such as divinylbenzene or di (meth) acrylate during synthesis (for example, addition of less than 1%) or adding a large amount of an initiator together with the crosslinking agent. This is one of the popular methods. At this time, it should be noted that when a three-dimensional network is formed by increasing the degree of crosslinking like a so-called commercially available water-absorbing resin, it becomes difficult to fix a recorded image or the energy required for fixing increases. is there. In order to ensure the fixing characteristics, it is necessary to adjust the crosslinking reaction to a part even if it occurs and to maintain the thermoplasticity as a whole as a whole.

  Further, the absorbent resin may be ion-crosslinked with ions supplied from the ink. When a unit containing a carboxylic acid is present in the resin such as a copolymer containing a carboxylic acid such as (meth) acrylic acid or maleic acid or a (branched) polyester having a carboxylic acid in the water absorbent resin, There exists a tendency for the intensity | strength of a resin image to increase. This is due to ionic crosslinking and acid-base interaction between the carboxylic acid in the resin and the alkali metal cation, alkaline earth metal cation, organic amine / onium cation, etc. supplied from the liquid such as water-based ink. I guess it is because the statue is strengthened.

  Moreover, the organic resin is good from the viewpoint of imparting hydrophilicity, charging / conductivity by including a polar group. For example, the polar group imparting hydrophilicity is the same as the hydrophilic monomer, and examples thereof include a hydroxyl group, an ethylene oxide group, a carboxylic acid, and an amino group. In the case of imparting positive chargeability, the introduction of a polar group that imparts charging / conductivity is, for example, introduction of a chloride-forming structure such as a (substituted) amino group, a (substituted) pyridine group or its amine salt, a quaternary ammonium salt, or the like. In the case of imparting charge, introduction of an organic acid (salt) structure such as carboxylic acid (salt) or sulfonic acid (salt) is effective. Furthermore, a charge control agent for electrophotographic toners such as low-molecular quaternary ammonium salts, organic borates, and salt-forming compounds of salicylic acid derivatives may be added to the organic resin. For conductivity control, addition of a conductive or semiconductive inorganic substance such as tin oxide or titanium oxide is effective.

  The organic resin is preferably an amorphous resin, and its glass transition temperature (Tg) is preferably 40 ° C to 90 ° C, more preferably 50 to 70 ° C. By setting the glass transition temperature within the above range, it is possible to achieve both particle handling properties, image blocking properties and image fixing properties. The glass transition temperature (and melting point) was determined from the main maximum peak measured according to ASTM D3418-8. DSC-7 manufactured by Perkin Elmer Co. can be used for measurement of the main maximum peak. The temperature correction of the detection part of this apparatus uses the melting point of indium and zinc, and the correction of heat quantity uses the heat of fusion of indium. As the sample, an aluminum pan was used, an empty pan was set as a control, and the measurement was performed at a heating rate of 10 ° C./min.

  The weight average molecular weight of the organic resin is preferably 3000 to 300,000, more preferably 10,000 to 100,000. By setting the weight average molecular weight within the above range, in the case of a liquid-absorbing resin, it is possible to achieve both quick liquid absorption, low-energy fixing and image strength after fixing. 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 organic resin is 50 to 1000 mgKOH / g in terms of carboxylic acid group (—COOH), more preferably 150 to 500 mgKOH / g, still more preferably 50 to 500 mgKOH / g, and particularly preferably 100. ~ 300 mg KOH / g. By controlling the acid value within the above range, it becomes possible to control the handling properties, water absorption and fixing properties of the particles. The acid value in terms of this carboxylic acid group (—COOH) was measured as follows.

  The acid value was measured according to JIS K0070 and using a neutralization titration method. That is, an appropriate amount of a sample is taken, 100 ml of a solvent (diethyl ether / ethanol mixed solution) and a few drops of an indicator (phenolphthalein solution) are added, and shaken sufficiently until the sample is completely dissolved in a water bath. This was titrated with a 0.1 mol / l potassium hydroxide ethanol solution, and the end point was when the indicator was light red 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.

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

  Next, other additives for the ink receiving particles of the present invention will be described. First, it is preferable that the ink receiving particles of the present invention include a component that aggregates or thickens the components of the ink. When the component is contained, the recording material (for example, pigment or dye) contained in the ink is aggregated or the viscosity of the polymer is increased, so that the image quality and fixability are improved.

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

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

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

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

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

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

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

  The organic acid is preferably citric acid, glycine, glutamic acid, succinic acid, tartaric acid, phthalic acid, pyrrolidone carboxylic acid, pyrone carboxylic acid, pyrrole carboxylic acid, furan carboxylic acid, pyridine carboxylic acid, coumaric acid, thiophene carboxylic acid, Nicotinic acid, derivatives of these compounds, or salts thereof. More preferred are pyrrolidone carboxylic acid, pyrone carboxylic acid, pyrrole carboxylic acid, furan carboxylic acid, pyridine carboxylic acid, coumaric acid, thiophene carboxylic acid, nicotinic acid, derivatives of these compounds, or salts thereof. More preferred are pyrrolidone carboxylic acid, pyrone carboxylic acid, furan carboxylic acid, coumaric acid, or a compound derivative thereof, or a salt thereof.

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

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

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

  The flocculant may be used alone or in combination of two or more. The content of the flocculant is preferably 0.01% by mass or more and 30% by mass or less. More preferably, they are 0.1 mass% or more and 15 mass% or less, More preferably, they are 1 mass% or more and 15 mass% or less.

  The ink receiving particles of the present invention preferably contain a release agent. This makes it possible to transfer and fix the ink receiving particles to the recording medium without oil. The release agent may be included in the organic resin, or the release agent particles may be combined with the organic resin particles.

  Examples of such release agents include low molecular weight polyolefins such as polyethylene, polypropylene, and polybutene; silicones having a softening point upon heating; fatty acids such as oleic acid amide, erucic acid amide, ricinoleic acid amide, and stearic acid amide Amides; plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil; animal waxes such as beeswax; montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, etc. Minerals and petroleum waxes, and modified products thereof. Among these, it is preferable to apply a crystalline compound.

  An external additive may be externally added to the ink receiving particles of the present invention. By externally adding an external additive, it is possible to impart powder flowability of the ink receiving particles, chargeability / conductivity control, liquid absorption control, and the like. External additives include inorganic particles (colorless, light or white particles such as colloidal silica, alumina, calcium carbonate, zinc oxide, titanium oxide, tin oxide, cerium oxide, carbon black), resin particles (vinyl-based). Resin, polyester, silicone, etc.). These particles as external additives may be either hydrophobic or hydrophilic, and may be surface-treated with a coupling agent (for example, a silane coupling agent) to give a specific functional group (for example, an amino group or fluorine-based surface). Etc.) may be introduced. The particle size as the external additive is a volume average particle size of 5 nm to 100 nm, preferably 10 to 50 nm.

(Marking material)
The marking material of the present invention comprises an ink containing at least a recording material and the ink receiving particles of the present invention. The marking material is a material that performs recording by allowing 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 can be used for both water-based ink and oil-based ink, but water-based ink is used from the viewpoint of environment. Aqueous ink (hereinafter simply referred to as ink) contains an ink solvent (for example, water, a water-soluble organic solvent) in addition to the recording material. In addition, other additives may be included as necessary.

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

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

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

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

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

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

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

  As the polymer dispersant, a polymer having a hydrophilic structure portion and a hydrophobic structure portion is preferably used. As the polymer having a hydrophilic structure portion and a hydrophobic structure portion, a condensation polymer and an addition polymer can be used. Examples of the condensation polymer include known polyester dispersants. Examples of the addition polymer include addition polymers of monomers having an α, β-ethylenically unsaturated group. The desired polymer dispersant is obtained 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 as appropriate. It is done. In addition, a homopolymer of a monomer having an α, β-ethylenically unsaturated group having a hydrophilic group can also be used.

  As the monomer having an α, β-ethylenically unsaturated group having a hydrophilic group, a monomer having a carboxyl group, a sulfonic acid group, a hydroxyl group, a phosphoric acid group, for example, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, Itaconic acid monoester, maleic acid, maleic acid monoester, fumaric acid, fumaric acid monoester, vinyl sulfonic acid, styrene sulfonic acid, sulfonated vinyl naphthalene, vinyl alcohol, acrylamide, methacryloxyethyl phosphate, bismethacryloxyethyl phosphate, Examples include methacryloxyethyl phenyl acid phosphate, ethylene glycol dimethacrylate, and diethylene glycol dimethacrylate.

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

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

  As the polymer dispersing agent, those having a weight average molecular weight of 2000 to 50000 are preferable from the viewpoint of coexistence of pigment dispersibility and ink dischargeability. More preferably, it is 3000-20000, and more preferably 4000-8000.

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

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

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

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

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

  In addition, a resin-dispersed pigment in which a high-molecular substance is chemically bonded to the pigment can also be used.

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

  The content (density) of the recording material is preferably 5 to 30% by mass, preferably 7 to 25% by mass, and more preferably 10 to 20% by mass with respect to the ink. When the content (concentration) is less than 5% by mass, there is a case where a sufficient optical density cannot be obtained. When the content is more than 30% by mass, the ink ejection characteristics become unstable. There was a case.

  The volume average particle size of the recording material is preferably 10 nm to 1000 nm, more preferably 30 nm to 250 nm, still more preferably 50 nm to 200 nm, and most preferably 60 nm to 120 nm. If the volume average particle size is too small, the optical density may be low. On the other hand, if the volume average particle size is too large, the storage stability may not be ensured.

  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. In the present invention, 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 parameters input at the time of measurement, the viscosity of the ink was input as the viscosity, and the density of the recording material was input as the density of the dispersed particles.

  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 include 6-hexanetriol and glycerin.

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

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

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

  It is preferable to use at least one water-soluble organic solvent. The content of the water-soluble organic solvent is 1 to 70% by mass, preferably 10 to 65% by mass, more preferably 20 to 60% by mass. When the amount of the water-soluble organic solvent in the ink is less than 1% by mass, a sufficient optical density may not be obtained. Conversely, when the amount is more than 70% by mass, the viscosity of the liquid is large. As a result, there are cases where the liquid ejection characteristics become unstable.

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

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

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

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

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

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

  These surfactants may be used alone or in combination. Further, the HLB of the surfactant is preferably in the range of 3 to 20 in view of dissolution stability and the like.

  0.001-5 mass% is preferable and, as for the addition amount of these surfactant, 0.01-3 mass% is especially preferable.

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

  Next, preferred characteristics of the ink will be described. First, the surface tension of the ink is preferably 20 to 45 mN / m, and more preferably 25 to 38 mN / m. When the surface tension is in the above range, it is possible to achieve both jetting stability, liquid absorbency with respect to ink receiving particles, and formation of high image quality. If the surface tension is low, jetting may be unstable, and if the surface tension is high, liquid absorption and high image quality formation may be deteriorated.

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

  The viscosity of the ink is preferably 1.5 to 30 mPa · s, more preferably 3 to 20 mPa · s. When the viscosity of the ink is in the above range, both ejection stability and liquid absorption / image quality can be achieved. When the viscosity is high, both high-speed jetting and high-speed liquid absorption are difficult. When the viscosity is low, jetting becomes unstable, and at the same time, the ink image on and in the ink receiving particles tends to be disturbed.

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

  The ink is not limited to the above configuration, and may include a functional material such as a liquid crystal material and an electronic material in addition to the recording material.

(Ink-receptive particle storage cartridge)
The ink receptive particle storage cartridge of the present invention is detachably disposed in the recording apparatus, and stores the ink receptive particles of the present invention, and the ink receptive particles in the particle coating apparatus (particle supply apparatus) of the recording apparatus. It is for supplying. By detaching the cartridge from the recording apparatus, the ink receiving particles can be easily replenished to the recording apparatus.

  Hereinafter, embodiments of the ink receiving particle storage cartridge of the present invention will be described with reference to the drawings. FIG. 3 is a perspective view showing the ink receiving particle storage cartridge 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 and 54 fitted to both ends of the particle storage cartridge main body 51. It consists of and.

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

  Accordingly, when the particle storage cartridge 50 is not attached to the recording apparatus (or just after attachment), the carry-out port 60 is stored in the storage unit 58, and the ink receiving particles in the particle storage cartridge main body 51 are removed from the carry-out port 60. It is designed not to 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 over substantially the entire area of 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 in the vertical direction 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, by discharging the particles from the carry-out port 60, the ink receiving particles can be additionally replenished to the recording apparatus.

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

(Recording method, recording device)
The recording method (recording apparatus) of the present invention is a recording method (recording apparatus) using an ink containing a recording material and the ink receiving particles of the present invention, and the step of receiving ink in the ink receiving particles. (Receiving means) and a step (transfer means) of transferring the ink receiving particles that have received the ink to a recording medium. Further, it may further include a step (fixing means) for fixing the ink receiving particles transferred onto the recording medium.

  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 transfer means. This transfer is selectively performed on the entire ink receptive particle layer or only on the recording portion (ink receiving portion). Thereafter, if necessary, the ink receiving particle layer transferred to the recording medium is pressed (or heated / pressed) 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 simultaneously.

  Here, the ink receptive particles are formed in, for example, a layer when receiving ink, and the thickness of the ink receptive particle layer is preferably 1 μm to 100 μm, more preferably 3 μm to 60 μm, still more preferably. 5 μm to 30 μm. 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 preferably 10% to 80%, more preferably. 30 to 70%, more preferably 40% to 60%.

  In addition, when the organic resin particles are composed of a liquid-absorbing resin, the ink-receptive particles absorb liquid (water) and the liquid (water) acts as a plasticizer for the resin. Fixing strength can be improved by ionic crosslinking formed between metal cations (clusters) supplied from the ink and the carboxylic acid of the resin when the liquid (water) evaporates with time.

  Further, a release agent may be applied to the surface of the intermediate in advance before supplying the ink receiving particles. This improves the transferability of the ink receiving particle layer. Examples of such release agents 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 permeable medium (for example, plain paper or coated paper) or a non-permeable medium (for example, a resin film) can be applied. The recording medium is not limited to these, and includes industrial products such as semiconductor substrates.

  Hereinafter, an embodiment of a recording apparatus of the present invention will be described with reference to the drawings. FIG. 5 is a schematic configuration diagram illustrating a recording apparatus according to the embodiment. FIG. 6 is a schematic configuration diagram illustrating a main part of the recording apparatus according to the embodiment. FIG. 7 is a schematic 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 FIG. 5, the recording apparatus 10 according to the embodiment includes an endless belt-shaped intermediate transfer body 12, a charging device 28 that charges the surface of the intermediate transfer body 12, and ink reception in a charged region on the intermediate transfer body 12. A particle coating device 18 for forming a particle layer by depositing the particles 16 uniformly and at a constant thickness, an ink jet recording head 20 for forming an image by ejecting ink droplets onto the particle layer, and a recording medium 8 superimposed on the intermediate transfer body 12. 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 coating device 18 via a supply pipe 19A.

  On the upstream side of the charging device 28, in order to improve the transfer efficiency of the ink receiving particle layer 16A from the surface of the intermediate transfer body 12 to the recording medium 8, the release of the ink receiving particle layer 16A from the surface of the intermediate transfer body 12 is promoted. A release agent coating device 14 for forming a release layer 14A is disposed.

  The surface of the intermediate transfer body 12 on which charge is formed by the charging device 28 is formed as a uniform layer of the ink receiving particles 16 by the particle coating device 18, and the ink jet recording head 20 for each color, that is, 20K, is formed on the particle layer. , 20C, 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 roller) 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 the ink receiving particles can be quickly carried out. Compared with the conventional method in which the recording medium 8 absorbs ink, Productivity can be increased.

  Further, if necessary, a charge removal device 29 for removing the charge remaining on the surface of the intermediate transfer body 12 may be disposed between the cleaning device 24 and the release agent coating device 14.

In this embodiment, the intermediate transfer member 12 has a surface layer made of ethylene propylene rubber (EPDM) having a thickness of 400 μm formed on a base layer made of a polyimide film having a thickness of 1 mm. Here, it is desirable that the surface resistance value is about 10 ¹³ Ω / □ and the volume resistance value is about 10 ¹² Ω · cm (semiconductive).

  The intermediate transfer body 12 is circulated and conveyed. First, a release layer 14A is formed on the surface of the intermediate transfer body 12 by the release agent coating device 14. The release agent 14D is applied to the surface of the intermediate transfer body 12 by the application roller 14C of the release agent application device 14, and the layer thickness is defined by the blade 14B.

  At this time, in order to continuously perform image formation and printing, the release agent coating device 14 may be continuously in contact with the intermediate transfer body 12 or may be appropriately separated from the intermediate transfer body 12. It is good also as such a structure.

  The release agent 14D may be supplied to the release agent application device 14 from an independent liquid supply system (not shown) so that the supply of the release agent 14D is not interrupted. In this embodiment, amino silicone oil is used as the release agent 14D.

  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 potential of the ink receiving particles 16 to be supplied / adsorbed to the surface of the intermediate transfer body 12 is formed by an electrostatic force due to an electric field that can be formed between the supply roller 18A of the particle coating device 18 and the surface of the intermediate transfer body 12. Good.

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

In the charging device 28, an elastic layer (foamed urethane resin) in which a conductivity-imparting material is dispersed is formed on a rod-shaped outer peripheral surface made of stainless steel, and the volume resistivity is adjusted to about 10 ⁶ to 10 ⁸ Ω · cm. A roll-shaped member is used. Further, the surface of the elastic layer is covered with a water / oil repellent skin layer (PFA) having a thickness of 5 to 100 μm. This is effective in suppressing changes in characteristics (resistance changes) due to changes in humidity in the apparatus and adhesion of a release agent to the surface of the charging layer.

  A DC power source is connected to the charging device 28, and the driven roll 31 is electrically connected to the frame ground. The charging device 28 is driven while sandwiching the intermediate transfer body 12 with the driven roll 31, and a predetermined potential difference is generated with the grounded driven roll 31 at the pressed position. An electric charge can be given. Here, a voltage 1 kv (constant voltage control) 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 constituted by a corotron or a brush. The applied voltage in this case is also performed under substantially the same conditions as described above. In particular, the corotron can apply a charge to the intermediate transfer member 12 in a non-contact manner.

  Next, the ink receiving particles 16 are supplied to the surface of the intermediate transfer body 12 by the particle applying device 18 to form the ink receiving particle layer 16A. In the particle coating device 18, a supply roller 18A is disposed on a portion of the container in which the ink receiving particles 16 are stored facing the intermediate transfer body 12, and a charging blade 18B is disposed so as to press the supply roller 18A. The charging blade 18B also has a function of regulating the layer thickness of the ink receiving particles 16 attached to the surface of the supply roller 18A.

  The ink receiving particles 16 are supplied to the supply roller 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 roller 18A can be a solid aluminum roll, and the charging blade 18B can be a metal plate (such as SUS) on which urethane rubber is caught to apply pressure. The charging blade 18B is in contact with the supply roller 18A by a doctor method.

  The charged ink receiving particles 16 form, for example, approximately one particle layer on the surface of the supply roller 18A, and are conveyed to a portion facing the surface of the intermediate transfer member 12, and when close to this, the supply roller 18A and the intermediate transfer member 12 are transferred. Due to the electric field formed by the potential difference from the surface, the charged ink receiving particles 16 move to the surface of the intermediate transfer member 12 by electrostatic force.

  At this time, the moving speed of the intermediate transfer body 12 and the rotation speed of the supply roller 18A are set relatively (peripheral speed ratio) so as to form approximately one particle layer on the surface of the intermediate transfer body 12. 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, the positional relationship between the supply roller 18A and the intermediate transfer member 12, and the like.

  The number of particles supplied onto the intermediate transfer body 12 can be reduced by relatively increasing the peripheral speed of the supply roller 18A on the basis of the peripheral speed ratio for forming the substantially one layer of the ink receiving particle layer 16A. Can be increased. Thereby, the layer thickness of the ink receiving particle layer 16A formed on the intermediate transfer body 12 can be controlled. That is, when the image density to be transferred is low (the ink ejection amount is small), the layer thickness is set to the minimum necessary thickness, and when the image density is high (the ink ejection amount is large), the ink liquid component It is preferable to control so that the layer thickness is sufficient to hold (solvent or dispersion medium).

  For example, in the case of a character image or the like with a small amount of ink shot, when image formation is performed on approximately one ink receiving particle layer on the intermediate transfer member, the image forming material (pigment) in the ink is the intermediate transfer member. It is trapped in the vicinity of the surface of the ink receptive particle layer and is fixed on the surface of the ink receptive particle or inside the particle gap so that the distribution in the depth direction is reduced. Therefore, there are few recording materials (for example, pigments) exposed on the surface of the image layer after transfer and fixing, compared to the case where an image is directly formed on the surface of the recording medium (most of the pigments are present in the vicinity of the surface), rubbing, etc. Sufficient fixing ability can be exhibited.

  For example, when it is desired to provide the particle layer 16C serving as the protective layer on the image layer 16B serving as the final image, the ink receiving particle layer 16A has a thickness of about three layers, and only the uppermost layer forms an image with ink. For example (see FIG. 7A), the two particle layers C on which image formation is not performed become a protective layer after transfer and fixing and are formed on the image layer 16B (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, The ink receptive particles 16 are laminated so that a sufficient number of particles are trapped and do not reach the lowest 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 brought into contact with each other to form a nip. . For the heating roll 22A and the pressure roll 22B, as in the case of an electrophotographic fixing device (fuser), it is possible to use a product in which the outer surface of an aluminum core is coated with silicone rubber and further coated with a PFA tube. it can.

  At the nip portion of the heating roll 22A and the pressure roll 22B, the ink receiving particle layer 16A is heated by the heater and pressure is applied, so that the ink receiving particle layer 16A is transferred to the recording medium 8 and fixed at the same time. .

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

  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, in order to prevent the ink receptive particles 16 from being inhibited from being secured on the surface of the intermediate transfer body 12 due to the securing of the releasability during transfer and the adhesion of moisture to the surface. Then, the release layer 14A is formed by the release layer coating apparatus 14. If the material of the intermediate transfer body 12 is aluminum or PET base, the effect of the release layer 14A is particularly great. 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 roller 18A of the particle coating device 18 are electrostatically adsorbed to form a uniform layer of ink receiving particles 16 on the surface of the intermediate transfer body 12. Can do.

  Next, the ink receiving particles 16 are formed on the surface of the intermediate transfer body 12 as a uniform layer by the supply roller 18 </ b> A of the particle coating 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 roller 18A as described above. To do. Alternatively, it may be controlled by the peripheral speed ratio between the supply roller 18 </ b> A and the intermediate transfer body 12.

  On the formed ink receiving particle layer 16A, ink droplets 20A are ejected by the ink jet recording head 20 of each color driven by piezoelectric (piezo), thermal, or the like, and an image layer 16B is formed on the ink receiving particle layer 16A. It 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 forming the ink receiving particles 16. At the same time, the recording material (for example, pigment) is also trapped on the surface of the ink receiving particles 16 (constituting particles) or 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 receiving particle layer 16A, but the recording material such as pigment is trapped on the surface of the ink receiving 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. Since it becomes a protective layer and a recording material (for example, a color material such as a pigment) is not exposed on the surface, a tough image resistant to abrasion can be formed.

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

  At this time, by adjusting heating and pressurization as described later, the unevenness of the image surface can be appropriately adjusted to control the glossiness. Further, the same effect may be obtained 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 present invention. As shown in FIG. 7A, a release layer 14A is provided on the surface of the intermediate transfer body 12 in order to ensure the release property during transfer and to prevent the adhesion of the ink receiving particles 16 due to moisture adhering to the surface. It is formed.

  Next, the ink receiving particles 16 are formed as a uniform layer on the surface of the intermediate transfer body 12 by the particle coating 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 receptive particle layer 16A is uniformly leveled so as not to hinder the image formation (formation of the image layer 16B) by the ejection of the ink droplet 20A.

  Also, the recording material such as pigment contained in the ejected ink droplet 20A penetrates to about 1/3 to half of the ink receiving particle layer 16A as shown in FIG. A particle layer 16C that is not infiltrated with the 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 roller) 22 is a particle layer containing no ink on the image layer 16B as shown in FIG. 7B. Since 16C exists, the image layer 16B does not appear directly on the surface and functions as a kind of protective layer. For this reason, at least the ink receiving particles 16 after fixing must be transparent.

  Since the particle layer 16C is heated and pressed by the transfer fixing device (transfer fixing roller) 22, the surface can be sufficiently smoothed, and the glossiness of the image surface can be controlled by heating and pressing. That is, by controlling either (or both) of the pressure / heat applied at the time of transfer and fixing, the state of the surface on which the image layer 16B is formed on the ink receiving particle layer 16A transferred and fixed on the recording medium 8 is changed. It is possible to make it. By increasing the pressure / heat, the roughness of the surface of the ink receiving particle layer 16A is reduced and gloss (gloss) is improved. Moreover, since the surface of the ink receiving particle layer 16A is not smoothed (rough surface) by reducing the pressure / heat, the gloss is lowered and the matte finish is achieved.

  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 receptive particle layer 16A is held in the ink receptive particle layer 16A even after transfer fixing, and the ink liquid component (solvent or As with the dispersion medium), it is removed by natural drying. For this reason, it is possible to form high-quality images at high speed with water-based ink in the same manner even with respect to the difference in ink permeability of the recording medium 8 and non-penetrating paper.

  Through the above steps, image formation is completed. For the intermediate transfer body 12, there are 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, and foreign matter such as paper dust that has detached from the recording medium 8. Alternatively, it may be removed by the cleaning device 24.

  Further, when the intermediate transfer body 12 is repeatedly charged, the charge amount may not be kept constant. In that case, a static eliminator 29 may be arranged downstream of the cleaning device 24. The surface of the intermediate transfer body 12 is applied to the surface of the intermediate transfer body 12 by applying an AC voltage of about ± 3 kV and about 500 Hz between the driven roll 31 (grounding) using a conductive roll similar to the charging device 28. It is possible to remove static electricity.

  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. Then, a desired result can be obtained.

<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 a belt shape or a cylindrical shape (drum shape) as in the embodiment. In order to supply and hold the ink receiving particles on the surface of the intermediate transfer member by electrostatic force, the outer peripheral surface of the intermediate transfer member needs to have a semiconductive or insulating particle holding property. As the electrical properties of the intermediate transfer member surface, the surface resistance in the case of semi-conductive ^{10 10 ~14Ω} / □, volume resistivity of ^{10 9 ~13Ω · cm, 10 14} Ω / □ in the case of insulation, the volume A member having a resistance value 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 improve the transfer efficiency of the ink receiving particles 16 (efficient transfer from the intermediate transfer body 12 to the recording medium 8), a release layer 14A is formed on the surface of the intermediate transfer body 12. desirable. The release layer 14A may be formed as the surface (material) of the intermediate transfer body 12 or may be externally added to form the release layer 14A on the surface of the intermediate transfer body 12 by an on-process.

  That is, when the surface of the intermediate transfer body 12 is a release layer 14A, a tetrafluoroethylene-ethylene copolymer, a polyvinylidene fluoride, a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, a tetrafluoroethylene / hexafluoropropylene copolymer A fluororesin such as a polymer, or an elastic body is preferably silicone rubber, fluorosilicone rubber, phenyl silicone rubber, or the like.

  In the case of forming the release layer 14A by external addition, in the case of a drum shape, an anodized surface of aluminum, in the case of a belt shape, the belt base material itself, or in the case of forming an elastic body Silicone rubber, fluorosilicone rubber, phenyl silicone rubber, fluoro rubber, chloroprene rubber, nitrile rubber, ethylene propylene rubber, styrene rubber, isoprene rubber, butadiene rubber, ethylene propylene butadiene rubber, nitrile Butadiene rubber or the like is used.

  In order to exhibit a heating method by electromagnetic induction in the fixing process in the transfer fixing device (transfer fixing roller) 22, a heat generating layer may be formed on the intermediate transfer body 12 instead of the transfer fixing device (transfer fixing roller) 22. 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>
An ink receiving particle layer 16 </ b> A is formed on the surface of the intermediate transfer body 12. At this time, as a method of forming the ink receptive particle layer 16A, a method of supplying a general electrophotographic toner to the photoreceptor can be applied. That is, charges are previously supplied to the surface of the intermediate transfer body 12 by a general electrophotographic charging method (charging by the charging device 28, etc.). The ink receiving particles 16 are triboelectrically charged (one-component triboelectric charging method or two-component method) with a polarity opposite to the charge on the surface of the intermediate transfer member 12.

  The ink receiving particles 16 held on the supply roller 18A form an electric field with the surface of the intermediate transfer member 12, and are moved / supplied onto the intermediate transfer member 12 by electrostatic force and held. At this time, it is also possible to control the thickness of the ink receptive particle layer 16A by adjusting the thickness of the image layer 16B formed on the ink receptive particle layer 16A (in accordance with the amount of ink to be driven). At this time, the charge amount of the ink receiving particles 16 is preferably in the range of 5 μc / g to 50 μc / g.

  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 roller 18A, and the thickness of the particle layer is regulated and charged by the charging blade 18B.

  The charging blade 18B functions to regulate the layer thickness of the ink receiving particles 16 on the surface of the supply roller 18A, and the layer thickness of the ink receiving particles 16 on the surface of the supply roller 18A is changed by changing the pressure applied to the supply roller 18A. It is possible to change. By setting the thickness of the ink receiving particles 16 on the surface of the supply roller 18A to approximately one layer, the thickness of the ink receiving particles 16 formed on the surface of the intermediate transfer body 12 can be formed to be approximately one layer. It is. Further, the thickness of the ink receptive particles 16 formed on the surface of the supply roller 18A is increased by controlling the pressing force of the charging blade 18B to be low, and the thickness of the ink receptive particles formed on the surface of the intermediate transfer member 12 is increased. Can be increased.

  As another method, when the peripheral speed of the supply roller 18A and the intermediate transfer body 12 that forms an approximately one particle layer on the surface of the intermediate transfer body 12 is 1, the intermediate speed can be increased by increasing the peripheral speed of the supply roller 18A. The number of ink receiving particles 16 supplied on the transfer body 12 can be increased, and the thickness of the ink receiving particle layer on the intermediate transfer body 12 can be controlled to be increased. It is also possible to control by combining the above methods. In the above configuration, for example, the ink receiving particles 16 are negatively charged, and the surface of the intermediate transfer body 12 is positively charged.

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

  As a charging roll in the charging device 28, an elastic layer in which a conductivity imparting material is dispersed is formed on the outer peripheral surface of a rod-like or pipe-like member made of aluminum, stainless steel or the like, and a volume resistivity of 10 ^ 6 to 10 ^ 8Ω. A roll having a diameter of 10 to 25 mm adjusted to about cm can be used.

  The elastic layer is made of a resin material such as urethane resin, thermoplastic elastomer, epichlorohydrin rubber, ethylene-propylene-diene copolymer rubber, silicon rubber, acrylonitrile-butadiene copolymer rubber, polynorbornene rubber, etc. A preferred material used in the above mixture is urethane foam resin.

  As the foamed urethane resin, those obtained by mixing and dispersing hollow bodies such as hollow glass beads and thermal expansion type microcapsules in urethane-based resin are desirable, and such a foamed urethane resin is desirable as a charging device. It has low hardness elasticity, high contact stability with respect to the conveyor belt, and good nip formation.

  Furthermore, the surface of the elastic layer may be covered with a water-repellent skin layer having a thickness of 5 to 100 μm. In that case, change in characteristics (resistance) due to humidity change in the apparatus or adhesion of ink mist to the surface of the charged layer. This is effective in suppressing (value change).

  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 roll 28 and the grounded driven roll 31 at the pressed 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 gaps (voids) formed in the ink receiving particles 16 to be recorded. The material (for example, pigment) is trapped on the surface of the ink receiving particles 16 or the interparticle gaps constituting the ink receiving particles 16.

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

  In order to ensure that the recording material (for example, pigment) is trapped in the surface of the ink receiving particle layer 16A and the inter-particle gap in the ink receiving particle 16, the ink and the ink receiving particles 16 are reacted to form a recording material ( For example, a method of quickly insolubilizing (aggregating) the pigment) may be employed. Specifically, it is possible to apply a reaction between an ink and a polyvalent metal salt or a pH reaction type for the above reaction.

  Further, in order to write an image at a high speed, a line type ink jet recording head (FWA) having a paper width is desirable, but images are sequentially formed on a particle layer formed on an intermediate transfer body using a conventional scan type ink jet recording head. May be formed. The ink discharge means of the inkjet recording head 20 is not limited as long as it is a means capable of discharging ink, such as a piezoelectric element drive type and a heating element drive type. As the ink itself, an ink using a conventional dye as a coloring material can be used, but a pigment ink is preferable.

  When the ink receptive particles 16 are reacted with ink, the ink receptive particles 16 are treated with an aqueous solution containing an aggregating agent (for example, a polyvalent metal salt) that reacts with the ink to agglomerate the pigment and dried. Use what you let.

<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 a method of performing transfer and fixing simultaneously is preferable. Fixing includes either a method of heating or pressurizing the ink receptive particle layer 16A, or a method of using both heating and pressurization, and a method of performing heating / pressing 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 portion of the ink receptive particle 16 layer formed on the intermediate transfer body 12 (the recording material (pigment) is trapped in the vicinity of the surface of the ink receptive particle layer 16A). By being transferred, the ink image is formed to be protected by the particle layer 16 </ b> C composed of the ink receiving particles 16. That is, since many recording materials (pigments) are not present in the uppermost layer of the ink receiving particle layer 16A transferred onto the recording medium 8, it is possible to prevent the influence of image disturbance due to rubbing or the like.

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

<Release layer>
In order to improve the transfer efficiency, it is possible to provide a step of forming a release layer 14A such as silicone oil on the surface of the intermediate transfer body 12 before supplying the ink receiving particles 16.
As the release layer, silicone oil, modified silicone oil, fluorine-based oil, hydrocarbon-based oil, mineral oil, vegetable oil, polyalkylene glycol, alkylene glycol ether, alkane diol, molten wax and the like can be considered.

  As the material of the elastic body, for example, silicone rubber, fluorine rubber, or the like can be used. Here, when silicone rubber is employed, if silicone oil is used as a lubricant, the silicone rubber swells. Therefore, in order to prevent this, it is preferable to provide a coating layer of fluororesin or fluororubber on the surface.

  The method for supplying the release layer 14A includes a method of forming the release layer 14A by incorporating an oil tank, supplying oil to the oil application member, and supplying oil to the surface of the intermediate transfer body 12 by the application member, For example, a method of forming a release layer 14A on the surface of the intermediate transfer body 12 by using an impregnated coating member is used.

<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 cleaning described above, the ink receiving particles 16 (residual particles 16D) remaining on the surface of the intermediate transfer body 12 are removed, and other than particles. 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>
Depending on the temperature and humidity conditions, the surface resistance of the intermediate transfer body 12 may be an inappropriate value. When the surface of the intermediate transfer body 12 has a high resistance, charges may be accumulated on the surface of the intermediate transfer body 12 during repeated particle supply operations, increasing the potential and affecting the formation of the particle layer. is there.

  Therefore, the surface of the intermediate transfer body 12 may be neutralized using the neutralization device 29 before forming the release layer 14A. As a result, the charge accumulated on the surface of the intermediate transfer body 12 can be removed, and the influence on the formation of the ink receiving particle layer 16A can be suppressed.

<Other forms>
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, the present invention is not limited to recording characters and images on a recording medium. That is, the droplet discharge device according to the present invention can be applied to all industrially used droplet discharge (jetting) devices.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, these examples do not limit the present invention. Unless otherwise specified, “part” means “part by mass”.

Example 1
-Production of particles A-
A plurality of polymers having different degrees of polymerization are prepared, mixed, adjusted so that the physical properties after mixing become a predetermined value (see below), and a styrene / n-butyl methacrylate polymer / acrylic acid copolymer (acid value 320 mgKOH / g / weight average molecular weight 100,000 / number average molecular weight 7,000 / Tg = 55 ° C.).

Then, 2.5% of 2,2-azobisisobutyronitrile was added to the styrene / n-butyl methacrylate polymer / acrylic acid copolymer in a mass ratio, and this was melt-mixed with an extruder. The powder thus obtained was pulverized using a jet mill, further classified using an ultrasonic vibration sieve, and particles A having a volume average particle size of 8 μm (porous styrene / n-butyl methacrylate fine particles, maximum An opening diameter of 330 nm / BET specific surface area (N ₂ ) of 240 m ² / g) was obtained.

(Example 2)
-Production of particle B-
2.5% of 2,2-azobisisobutyronitrile was added to the branched polyester polymer (acid value 25 mg KOH / g / weight average molecular weight 60,000 / number average molecular weight 2,500 / Tg = 75 ° C.) in a mass ratio. This was melt mixed with an extruder. The powder obtained in this manner was pulverized using a jet mill, further classified using an ultrasonic vibration sieve, and particles B having a volume average particle diameter of 5 μm (porous polyester polymer particles: maximum opening diameter 580 nm / BET specific surface area (N ₂ ) 320 m ² / g) was obtained.

(Example 3)
-Production of particles C-
30 parts by mass of butyl acrylate, 10 parts by mass of diethylene glycol dimethacrylate, and 0.4 parts by mass of benzoyl peroxide were added to a mixed solvent of n-hexane / ethyl acetate to obtain a solution A. On the other hand, a solution B in which 10 parts by mass of polyvinyl alcohol and 0.04 parts by mass of sodium lauryl sulfate were dissolved in ion-exchanged water was obtained.

Then, the solution A and the solution B were added and dispersed in the homomixer. This solution was heated and stirred. The product thus obtained was filtered. The particles thus obtained were dried using a freeze dryer, and particles C having a volume average particle diameter of 7 μm (porous acrylate particles: maximum opening diameter 800 nm / BET specific surface area (N ₂ ) 60 m ² / g Got.

Example 4
-Production of particles D-
-Particle A: 100 parts by mass-Alumina (A33F / Nippon Light Metal Co., Ltd .: volume average particle size 0.7 μm, non-porous): 15 parts by mass The materials are mixed in the above composition ratio, and a trace amount of a bactericidal aqueous solution (Proxel) GXL (S) manufactured by Arch Chemicals Japan), stirring and mixing (about 30 seconds with a sample mill), then measuring the particle size for each intermittent drive condition with a mechano-fusion system, At this stage, it was taken out and formed into composite particles. In this way, base particles having a sphere equivalent average particle diameter of 10 μm were obtained.

Subsequently, for 100 parts by mass of the base particles,
Polypropylene wax (Pelestat 300 / manufactured by Sanyo Chemical Co., Ltd.): 1 part by mass Zinc stearate: 0.2 part by mass Alumina (A33F / Nippon Light Metal Co., Ltd .: volume average particle diameter 0.7 μm, non-porous): 1 part by mass The parts were stirred and mixed to prepare particles D having a sphere equivalent average diameter of 10 μm.

(Example 5)
-Production of particles E-
-Particle B: 100 parts by mass- Styrene / n-butyl methacrylate / acrylic acid copolymer particles (non-porous particles: volume average particle size 0.2 μm / acid value 240 mg KOH / g / Tg 60 ° C./weight average molecular weight 15, 000 / number average molecular weight 6,000 liquid absorbency: weak liquid absorbency): 30 parts by mass / polyvinyl alcohol: 0.5 part by mass The materials are mixed in the above composition ratio, and a small amount of a bactericidal agent aqueous solution (Proxel GXL (S ) (Arch Chemicals Japan) was added and stirred and mixed (about 30 seconds with a sample mill), then the particle size was measured for each intermittent drive condition with a mechano-fusion system, and the average particle size in terms of sphere was 8 μm To take composite particles. In this way, base particles having a sphere equivalent average particle diameter of 8 μm were obtained.

Subsequently, for 100 parts by mass of the base particles,
-Paraffin wax (OX-3215 / Nippon Seiwa Co., Ltd.): 1 part by mass-Stearyl alcohol: 0.15 part by mass were stirred and mixed to prepare particles E with a sphere equivalent average diameter of 8 µm.

(Example 6)
-Production of particles F-
-Particle C: 100 parts by mass-n-butyl methacrylate / acrylic acid copolymer particles (non-porous particles: volume average particle size 0.5 μm / acid value 120 mg KOH / g / Tg 70 ° C./weight average molecular weight 25,000 / Number average molecular weight 8,500 liquid absorbency: weak liquid absorbency)
Amorphous silica (Aerosil 130 / Degussa: volume average particle size 16 nm, non-porous): 15 parts by mass Polyvinyl alcohol: 0.5 parts by mass A material is mixed in the above composition ratio, and a trace amount of a bactericidal aqueous solution. (Proxel GXL (S) manufactured by Arch Chemicals Japan), and after stirring and mixing (about 30 seconds in a sample mill), the particle size is measured for each intermittent drive condition with a mechano-fusion system, and the average particle size in terms of sphere When it became 8 μm, it was taken out and formed into composite particles. In this way, base particles having a sphere equivalent average particle diameter of 8 μm were obtained.

Subsequently, for 100 parts by mass of the base particles,
Amorphous silica (Aerosil 130 / Degussa: volume average particle diameter: 16 nm, non-porous)): 1 part by mass was stirred and mixed to prepare particles F having a sphere equivalent average diameter of 8 μm.

(Comparative Example 1)
-Preparation of particles G-Acrylic acid / alkyl methacrylate copolymer (non-porous particles: Carbopol ETD2020 / Nikko Chemical Co., Ltd .: liquid absorbency: weak liquid absorbency resin): 80% by mass
Carboxyvinyl polymer (non-porous particles: Carbopol ETD2050 / Nikko Chemical Co., Ltd .: liquid absorption: liquid absorbent resin): 20% by mass
The acrylic acid / alkyl methacrylate copolymer and the carboxyvinyl polymer were respectively charged into a jet mill and pulverized. The obtained particles were subjected to an airflow classifier to obtain particles having a sphere equivalent average particle diameter of 5 μm. The particles thus obtained were mixed with materials at the above composition ratio to obtain particles G.

(Comparative Example 2)
-Production of particles H-
Amorphous silica (Aerosil OX50 / Degussa :: volume average particle diameter 40 nm, non-porous) was obtained, and this was designated as particle H.
(Comparative Example 3)
-Production of particles I-
Styrene / n-butyl methacrylate polymer / acrylic acid copolymer particles (non-porous particles: volume average particle diameter 30 μm / acid value 320 mgKOH / g / weight average molecular weight 100,000 / number average molecular weight 7,000 / Tg = 55 C / liquid absorption: weak liquid absorption resin): 90 parts by mass Amorphous silica (Aerosil OX50 / Degussa: volume average particle size 40 nm, non-porous): 10 parts by mass The materials were mixed at the above composition ratio. This was designated as Particle I.

(Comparative Example 4)
-Production of particles J-
Styrene / n-butyl methacrylate polymer / acrylic acid copolymer particles (non-porous particles: volume average particle diameter 30 μm / acid value 320 mgKOH / g / weight average molecular weight 100,000 / number average molecular weight 7,000 / Tg = 55 ° C / Liquid absorbency: Weak liquid absorbent resin): 30 parts by mass Amorphous silica (Aerosil OX50 / Degussa: volume average particle size 40 nm, nonporous): 70 parts by mass Polyvinyl alcohol: 0.5 parts by mass Part The above composition is mixed, and a small amount of a bactericidal solution (Proxel GXL (S) manufactured by Arch Chemicals Japan) is added and stirred and mixed (about 30 seconds in a sample mill), and then intermittent drive conditions in a mechanofusion system. The particle size was measured every time, and it was taken out at the stage when the average particle size in terms of sphere became 8 μm, and formed into composite particles. In this way, base particles having a sphere equivalent average particle diameter of 8 μm were obtained.

(Evaluation)
The following evaluation was performed using the particles of the above Examples and Comparative Examples and the following ink A. The results are shown in Table 1.

-Ink A-
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.

-Ink component-
Cyan pigment (Pig. Blue 15-3) (volume average particle size 80 nm) / dispersant resin (acid value = 150 mg KOH / g, dispersant containing carboxylic acid: acid value containing styrene / acrylic acid: 200 mg KOH / g high 2 parts of molecular dispersing agent): 12 parts ・ Butyl carbitol: 5 parts ・ Diethylene glycol: 10 parts ・ Glycerol: 25 parts ・ Nonionic surfactant (acetylene glycol derivative): 1 part ・ pH adjuster, fungicide (Proxel GXL) (S) Arch Chemicals Japan): Trace amount ・ Pure water: 60 parts

  The obtained ink had a surface tension = 33 mN / m, a viscosity = 9.1 mPa · s, and a pH = 7.8.

-Drying time-
Using OK Kanto (manufactured by Oji Paper Co., Ltd.) as the recording medium, a load of 1.9 × 10 ⁴ N / m ² is applied on the printed pattern after a predetermined time has elapsed after creating a 100% coverage pattern. Press it with. At this time, the time during which no liquid was transferred to the pressed OK Kanto paper side was defined as the drying time.
The evaluation criteria are as follows.
A: Drying time is less than 0.5 seconds B: Drying time is less than 1 second Δ: Drying time is 1 second or more and less than 3 seconds X: Drying time is 3 seconds or more

-Optical density-
A 100% coverage pattern was created using OK Kanto (manufactured by Oji Paper Co., Ltd.) as the recording medium, and the optical density of the printed portion was measured using X-Rite 404 (manufactured by X-Rite).
The evaluation criteria are as follows.
◎: Optical density is 1.6 or more ○: Optical density is 1.5 or more Δ: Optical density is 1.3 or more and less than 1.5 ×: Optical density is less than 1.3

-Fixability-
Using OK Kanto (manufactured by Oji Paper Co., Ltd.) as a recording medium, a 100% coverage pattern was created and left in a general environment for 24 hours. After leaving, press another OK Kanto on the printing surface with a load of 4.9 × 10 ⁴ N / m ² , rub, and check the degree of dirt on the rubbed paper side against a predetermined limit sample. Evaluation was performed.
The evaluation criteria are as follows.
◎: Dirt is not generated. ○: Dirt is hardly generated. △: Dirt is generated, but is at an acceptable level.

  From the above results, since the ink receiving particles of this example are composite particles containing at least organic resin particles (porous particles) having voids, liquid absorption by the voids of the organic resin particles is performed in addition to the interparticle gaps. Therefore, it can be seen that the liquid absorption speed is faster and the drying time is faster than the comparative example.

  It can also be seen that the use of the ink receiving particles of this example improves various properties such as optical density, fixability, and color developability.

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. 1 is a schematic configuration diagram illustrating a recording apparatus according to an embodiment. 1 is a schematic configuration diagram illustrating a main part of a recording apparatus according to an embodiment. It is a schematic block diagram which shows the ink receptive particle layer which concerns on embodiment.

Explanation of symbols

8 Recording medium 10 Recording device 12 Intermediate transfer member 14 Release agent coating device 14A Release layer 14B Blade 14C Application roller 14D Release agent 16 Ink receiving particle 16A Ink receiving particle layer 16B Image layer 16C Particle layer 16D Residual particle 18 Particle coating device 18A Supply roller 18B Charging blade 19 Ink receiving particle storage cartridge 19A Supply tube 20 Inkjet recording head 20A Ink droplet 22 Transfer fixing device (transfer fixing roller)
22A Heating roll 22B Pressurizing roll 24 Cleaning device 28 Charging device 29 Static elimination device 31 Follower roll 50 Ink-receptive particle storage cartridge 51 Particle storage cartridge main body 52 Side wall portion 54 Side wall portion 56 Band portion 58 Storage portion 60 Unloading port 62 Hole 64 Cup Ring part 66 Connecting part 68 Agitator 100 Composite particle 102 Organic resin porous particle 104 Non-porous particle

Claims (12)

Ink receptive particles for receiving ink,
Ink-receiving particles containing at least organic resin particles having voids.   The ink receiving particles according to claim 1, wherein the organic resin particles having voids are organic resin porous particles.   The ink receiving particles according to claim 1, wherein the ink receiving particles are composite particles in which organic resin particles having the voids are gathered.   The ink receiving particle according to claim 3, wherein the composite particle is a composite particle in which organic resin non-porous particles and / or inorganic non-porous particles are aggregated in addition to the organic resin particles having the voids. .   4. The ink receiving particles according to claim 3, wherein a gap between the particles constituting the composite particles is 0.1 to 5 [mu] m in maximum diameter.   A marking material comprising an ink and the ink receptive particles according to claim 1. A method for receiving ink in the ink receiving particles according to any one of claims 1 to 5,
An ink receiving method comprising a trap step of trapping at least a liquid component of the ink in a gap between the organic resin particles having the voids in the composite particles. A recording method using an ink and the ink receiving particles according to any one of claims 1 to 5,
Receiving the ink in ink receiving particles;
Transferring the ink receiving particles that have received the ink to a recording medium;
A recording method.   The recording method according to claim 8, further comprising a step of fixing the ink receiving particles transferred onto the recording medium. A recording apparatus using ink and the ink receiving particles according to any one of claims 1 to 5,
Discharging means for receiving the ink in ink receiving particles;
Transfer means for transferring the ink receiving particles that have received the ink to a recording medium;
A recording apparatus.   The recording apparatus according to claim 10, further comprising a fixing unit that fixes the ink receiving particles transferred onto the recording medium.   An ink receptive particle storage cartridge that is detachably disposed in a recording apparatus and stores the ink receptive particles according to claim 1.