JP2021126859A - Inkjet recording method and inkjet recording device - Google Patents

Abstract

To provide a transfer type inkjet recording method which has good washability of a transfer body, and enables repeated recording of such a high-quality image as to prevent dot chip and blanking.SOLUTION: An inkjet recording method records an image onto a recording medium 108 using aqueous ink. The inkjet recording method includes a step of imparting an aqueous reaction liquid onto a transfer body 101, a step of imparting the aqueous ink into the transfer body and forming an intermediate image, a step of bringing the intermediate image into contact with the recording medium, and transferring it thereto, and imparting an aqueous washing liquid onto the transfer body, and washing the transfer body, in this order. The reaction liquid further contains a particulate wax obtained by emulsifying a polyolefin wax with a nonionic emulsifier and an anionic emulsifier, the nonionic emulsifier is polyoxyethylene alkyl ether having an HLB value of 13.6 or more and 15.9 or less, and the anionic emulsifier is a sulfate-based surfactant having an alkyl group having 8 to 18 carbon atoms.SELECTED DRAWING: Figure 1

Description

The present invention relates to an inkjet recording method and an inkjet recording device.

Water-based inks are widely used as inks used in inkjet recording methods. An intermediate image is formed on a transfer body in order to quickly remove the liquid component in the ink, and after removing the liquid component contained in the intermediate image, the image is transferred to a recording medium to record the image, which is a so-called transfer method image. There is a recording method.

In the inkjet recording method adopting the transfer method, there is a problem that the residue on the transfer body tends to affect the quality of the image recorded thereafter, and the image quality may be deteriorated. More specifically, the residue on the transfer body affects the contact state between the transfer body and the recording medium when the image is subsequently recorded, and transfer failure occurs. When a transfer defect occurs, the image may appear whitish (white spots occur) in a slight case, but in severe cases, dots may be chipped and the image quality may be deteriorated.

In order to solve the above problems, for example, a method of applying a cleaning liquid containing a component that agglutinates the color material component in the ink to clean the transferred body has been proposed (Patent Document 1). Further, an image forming apparatus having a means for applying a liquid to a transfer body for cleaning and a means for bringing an adhesive means having a larger adhesive force than the transfer body into contact with the transfer body for cleaning has been proposed (Patent Documents). 2).

Japanese Unexamined Patent Publication No. 2011-093198 Japanese Unexamined Patent Publication No. 2009-07928

The present inventors have studied the repeated recording of images using the devices proposed in Patent Documents 1 and 2. As a result, it was found that the transfer body was not sufficiently washed by repeatedly recording the image, and the image quality such as missing dots and white spots was likely to be deteriorated.

Therefore, an object of the present invention is to provide a transfer-type inkjet recording method capable of repeatedly recording a high-quality image having good cleanability of a transfer body and less likely to cause missing dots or white spots. be. Another object of the present invention is to provide an inkjet recording apparatus used in this inkjet recording method.

That is, according to the present invention, it is an inkjet recording method for recording an image on a recording medium using a water-based ink, and is a reaction of imparting an aqueous reaction solution containing a reactant that reacts with the water-based ink to the transfer body. A liquid application step, an intermediate image forming step of applying the water-based ink to a transfer body to form an intermediate image, a transfer step of bringing the intermediate image into contact with the recording medium and transferring the intermediate image, and a water-based cleaning liquid on the transfer body. The reaction solution further contains a particulate wax obtained by emulsifying a polyolefin wax with a nonionic emulsifier and an anionic emulsifier. The sex emulsifier is a polyoxyethylene alkyl ether having an HLB value of 13.6 or more and 15.9 or less, and the anionic emulsifier is a sulfate ester-based surfactant having an alkyl group having 8 or more and 18 or less carbon atoms. An inkjet recording method characterized by the above is provided.

According to the present invention, it is possible to provide a transfer type inkjet recording method capable of repeatedly recording a high-quality image in which the transfer material has good detergency and is less likely to cause missing dots or white spots. Further, according to the present invention, it is possible to provide an inkjet recording apparatus used in this inkjet recording method.

It is a schematic diagram which shows one Embodiment of the inkjet recording apparatus of this invention.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. In the present invention, when the compound is a salt, the salt is dissociated into ions and exists in the ink, but for convenience, it is expressed as "containing a salt". Further, the water-based ink, reaction liquid, and cleaning liquid for inkjet may be simply referred to as "ink", "reaction liquid", and "cleaning liquid". The physical characteristic value is a value at room temperature (25 ° C.) unless otherwise specified. When described as "(meth) acrylic acid" and "(meth) acrylate", they mean "acrylic acid, methacrylic acid" and "acrylate, methacrylate", respectively.

The present inventors added a particulate wax emulsified by an emulsifier in order to record an image having excellent fastness such as scratch resistance comparable to an image recorded by offset printing by a transfer type inkjet recording method. An aqueous reaction solution was examined. After applying the reaction solution containing wax to the transfer body, ink is further applied to form an intermediate image. Next, when the formed intermediate image is transferred to a recording medium and the image is recorded, wax is present near the surface of the image, and the robustness of the image is improved.

Furthermore, the present inventors investigated the reason why the image quality deteriorates due to repeated recording. A component that has not been transferred to the recording medium remains as a residue on the transfer body after the intermediate image is transferred to the recording medium. Since the transcript is used repeatedly, inadequate removal of the residue by washing will result in the formation of an intermediate image on the residue in subsequent steps. Since the intermediate image formed on the residue is difficult to be transferred to the recording medium, missing dots and white spots are likely to occur, and it is considered that the image quality is deteriorated. In particular, when a reaction solution containing wax is used for forming an intermediate image, the wax acts like an adhesive and tends to remain on the transfer body. Further, in particular, when the image is recorded at high speed, the washing is also performed at high speed, so that a residue is likely to be generated on the transfer body.

Under such circumstances, the present inventors weaken the adhesive force of the wax to the transfer body in order to suppress the deterioration of the image quality that occurs when the image is repeatedly recorded using the reaction solution containing the wax. I thought it was necessary. Then, they have found that deterioration of image quality can be suppressed by designing the type of wax, the type of emulsifier that emulsifies the wax, and the physical properties, and have reached the configuration of the present invention. Specifically, a reaction solution containing a particulate wax emulsified with a polyolefin wax with a nonionic emulsifier and an anionic emulsifier is used. As the nonionic emulsifier, a polyoxyethylene alkyl ether having an HLB value of 13.6 or more and 15.9 or less is used. As the anionic emulsifier, a sulfuric acid ester-based surfactant having an alkyl group having 8 or more and 18 or less carbon atoms is used. By adopting the above configuration, it is possible to improve the redispersibility of the wax in the cleaning liquid applied to the transfer body after transfer while maintaining the robustness of the recorded image. That is, by using a reaction solution containing a particulate wax obtained by emulsifying a polyolefin wax with a specific emulsifier as described above, the wax that is a residue can be easily washed from the transfer body after the intermediate image transfer. Can be removed. As a result, it is possible to suppress the deterioration of image quality that occurs when the image is repeatedly recorded.

<Inkjet recording method and inkjet recording device>
The inkjet recording method of the present invention (hereinafter, also simply referred to as “recording method”) is a method of recording an image on a recording medium using water-based ink. The recording method of the present invention includes a reaction solution application step, an intermediate image forming step, a transfer step, and a washing step in this order. The reaction solution applying step is a step of applying an aqueous reaction solution containing a reactant that reacts with the aqueous ink to the transcript. The intermediate image forming step is a step of applying water-based ink to the transfer body to form an intermediate image. The transfer step is a step of bringing an intermediate image into contact with a recording medium and transferring the image. The cleaning step is a step of applying an aqueous cleaning solution to the transfer body to clean the transfer body. That is, the recording method of the present invention is a transfer type inkjet recording method.

Further, the inkjet recording apparatus of the present invention (hereinafter, also simply referred to as “recording apparatus”) is an apparatus used for recording an image on a recording medium using water-based ink. The recording apparatus of the present invention includes a reaction liquid applying means, an ink applying means, a transfer means, and a cleaning means. The reaction solution applying means is a means for applying an aqueous reaction solution containing a reactant that reacts with the aqueous ink to the transcript. The ink applying means is a means for forming an intermediate image by ejecting water-based ink by an inkjet method and applying it to a transfer body. The transfer means is a means for transferring an intermediate image by bringing it into contact with a recording medium. The cleaning means is a means for applying an aqueous cleaning solution to the transfer body to clean the transfer body. That is, the recording device of the present invention is a so-called transfer type inkjet recording device.

FIG. 1 is a schematic view showing an embodiment of the inkjet recording apparatus of the present invention. The transfer-type inkjet recording device 100 shown in FIG. 1 is a single-wafer inkjet recording device that produces a recorded material by transferring an intermediate image to a recording medium 108 via a transfer body 101. The X direction, the Y direction, and the Z direction indicate the width direction (total length direction), the depth direction, and the height direction of the transfer type inkjet recording apparatus 100, respectively. The recording medium is conveyed in the X direction.

The transfer type inkjet recording device 100 includes a transfer body 101, a reaction liquid applying device 103, an ink applying device 104, a liquid absorbing device 105, and a pressing member 106. The transfer body 101 is supported by the support member 102. The reaction solution applying device 103 is an device that applies a reaction solution containing a reactant that reacts with ink to the transfer body 101. The ink applying device 104 includes a recording head that applies ink to the transfer body 101 to which the reaction solution has been applied to form an intermediate image. The liquid absorbing device 105 is a device that absorbs a liquid component from an intermediate image. The pressing member 106 is a member for transferring an intermediate image from which the liquid component has been removed to a sheet-shaped recording medium 108 such as paper. Further, the transfer type inkjet recording apparatus 100 has a transfer body cleaning member 109 that cleans the surface of the transfer body 101 after transfer. The transfer body 101, the reaction liquid application device 103, the recording head of the ink application device 104, the liquid absorption device 105, and the transfer body cleaning member 109 each have a length corresponding to the recording medium 108 used in the Y direction. ..

The transfer body 101 rotates in the direction of arrow A about the rotation axis 102a of the support member 102. After the reaction solution is applied to the rotating transfer body 101 from the reaction solution application device 103, the ink is applied from the ink application device 104 to form an intermediate image on the transfer body 101. The intermediate image formed on the transfer body 101 moves to a position where it comes into contact with the liquid absorption member 105a of the liquid absorption device 105 by the rotation of the transfer body 101.

The liquid absorbing member 105a constituting the liquid absorbing device 105 moves (rotates) in the direction of the arrow B in synchronization with the rotation of the transfer body 101. The intermediate image formed on the transfer body 101 comes into contact with the moving liquid absorbing member 105a. Meanwhile, the liquid absorbing member 105a absorbs and removes the liquid component from the intermediate image. From the viewpoint of efficiently absorbing the liquid component of the intermediate image, the liquid absorbing member 105a is preferably pressed against the transfer body 101 with a predetermined pressing force. The intermediate image is formed of ink and a reaction solution used as needed. Therefore, absorbing the liquid component of the intermediate image means absorbing the liquid component in the ink and the reaction liquid used as needed. It can be said that absorbing the liquid component from the intermediate image means concentrating the ink or the like. Concentration of ink and the like increases the ratio of solids such as coloring materials and resins to liquid components.

The intermediate image in which the liquid component is removed and the ink is concentrated is moved to the transfer unit 111 in contact with the recording medium 108 conveyed by the recording medium transfer device 107 by the rotation of the transfer body 101. The intermediate image and the recording medium 108 are pressed from the pressing member 106 side and come into contact with each other while being sandwiched between the transfer body 101 and the pressing member 106. When the roller-shaped transfer body 101 and the columnar pressing member 106 are used, the intermediate image and the recording medium 108 come into linear contact with each other along the Y direction. When the transfer body 101 made of an elastic material is used, the transfer body 101 is dented by pressing, so that the intermediate image and the recording medium 108 come into contact with each other on the surface. Therefore, the line or surface where the intermediate image and the recording medium 108 come into contact with each other is referred to as a "region", and the portion including this region is referred to as a transfer unit 111. While the intermediate image is in contact with the recording medium 108, the pressing member 106 presses the transfer body 101 to transfer the intermediate image to the recording medium 108, and the desired image is recorded on the recording medium 108. The image after transfer is an inverted image of the intermediate image before transfer.

When the reaction solution is applied to the transfer body using the roller-shaped reaction solution application member 103c, the reaction solution is applied to the entire transfer body. Since ink is applied to the transfer body to which the reaction solution has been applied to form an intermediate image, the reaction solution that has not reacted with the ink remains in the region of the transfer body to which the ink has not been applied. The liquid absorbing member 105a can remove not only the liquid component of the unreacted reaction liquid but also the liquid component of the unreacted reaction liquid from the intermediate image. The liquid component contained in the ink or the reaction liquid does not have a certain shape but has fluidity and exists in a substantially constant volume. Specifically, the liquid component contained in the ink or the reaction liquid is an aqueous medium or the like.

Hereinafter, the main parts of the transfer type inkjet recording device are [1] transfer body, [2] support member, [3] reaction liquid application device, [4] ink application device, [5] liquid absorption device, [6]. The pressing member, [7] recording medium, [8] recording medium conveying device, and [9] cleaning device will be described.

[1] Transfer The transfer body 101 has a surface layer including a surface on which an intermediate image is formed. Examples of the material constituting the surface layer include resin and ceramic. Among them, a resin having a siloxane structure is preferable, and a material having a high compressive elastic modulus is preferable from the viewpoint of durability and the like. In order to improve the wettability and transferability of the reaction solution, it may be used after being surface-treated.

The transfer material preferably has a compression layer having a function of absorbing pressure fluctuations between the surface layer and the support member. The compression layer disperses local pressure fluctuations and absorbs deformation of the surface layer. Therefore, by providing the compression layer, good transferability can be maintained even in the case of high-speed recording. Examples of the material constituting the compression layer include an elastic material such as a rubber material. Among them, a rubber material having a porous structure formed by blending a filler such as a foaming agent, hollow fine particles, and a salt with a vulcanizing agent and a vulcanization accelerator into a raw material rubber is preferable. In such an elastic material, when the pressure fluctuates, the void portion is compressed with a volume change, so that the deformation in the direction other than the compression direction is small. Therefore, transferability and durability can be improved. Examples of the porous structure include a continuous void structure in which voids are interconnected and an independent void structure in which the voids are independent of each other.

The transfer material preferably has an elastic layer between the surface layer and the compression layer. Examples of the material constituting the elastic layer include a resin material and a ceramic material. Among them, an elastic material such as a rubber material is preferable because it is easy to process, the change in elastic modulus with temperature is small, and the transferability is excellent.

The layers (surface layer, elastic layer, compression layer) constituting the transfer body can be adhered to each other by using an adhesive or double-sided tape. A reinforcing layer having a high compressive elastic modulus may be provided in order to suppress lateral elongation when mounted on the device and maintain elasticity. As the reinforcing layer, a woven fabric or the like can be used. Of the layers constituting the transfer body, the elastic layer and the compression layer can be arbitrarily combined for the layers other than the surface layer. The size of the transfer body can be freely selected according to the recording speed and the size of the image. Examples of the shape of the transfer body include a sheet shape, a roller shape, a belt shape, an endless web shape, and the like.

[2] Support member The transfer body 101 is supported on the support member 102. The transfer body can be arranged on the support by using, for example, an adhesive or double-sided tape. The transfer body 101 may be arranged on the support member 102 by using an installation member made of a material such as metal, ceramic, or resin. The support member 102 is required to have a certain level of structural strength from the viewpoint of transport accuracy and durability. Examples of the material of the support member include metal, ceramic, and resin. Of these, it is preferable to use a metal material such as aluminum. By using a metal material, it is possible to improve the responsiveness of control by reducing the inertia during operation as well as the rigidity and dimensional accuracy that can withstand the stress during transfer.

[3] Reaction Solution Applying Device The recording method of the present invention includes a reaction solution applying step of applying the reaction solution to the transcript before the intermediate image forming step. The reaction solution contains a reactant that reacts with the ink when it comes into contact with the ink and aggregates components having anionic groups such as resin and self-dispersing pigment in the ink. After applying the ink, the reaction solution may be further applied so that at least a part of the area to which the ink is applied overlaps.

The transfer-type inkjet recording device 100 shown in FIG. 1 has a reaction solution applying device 103 which is a reaction solution applying means for applying the reaction solution to the transfer body 101. The reaction solution application device 103 is a gravure offset roller having a reaction solution accommodating unit 103a for accommodating the reaction solution and reaction solution application members 103b and 103c for applying the reaction solution in the reaction solution accommodating unit 103a to the transcript 101. .. Examples of the reaction liquid applying device include a gravure offset roller and an inkjet recording head. Above all, it is preferable to apply the reaction solution to the transcript using a roller.

[4] Ink Applying Device The transfer type inkjet recording device 100 shown in FIG. 1 has an ink applying device 104 which is an ink applying means for applying ink to the transfer body 101. It is preferable to use an inkjet recording head as an ink applying device and eject and apply ink. The recording head includes, for example, a form in which a film is boiled in the ink by an electric-heat converter to form bubbles to eject the ink; a form in which the ink is ejected by an electric-mechanical converter; ink using static electricity. The form of discharging the ink can be mentioned. Among them, a recording head in the form of using an electric-heat converter is preferable because it can record a high-density image at a higher speed.

The recording head is a full-line head extending in the Y direction, and the discharge ports are arranged in a range covering the width of the image recording area of the maximum usable recording medium. The recording head has a discharge port surface having a discharge port opened on its lower surface (transfer body 101 side). The discharge port surface faces the surface of the transfer body 101 with a minute gap (about several millimeters).

The ink applying device 104 may have a plurality of recording heads in order to apply inks of each color such as cyan, magenta, yellow, and black (CMYK) to the transfer body 101. For example, when forming an intermediate image using four types of CMYK inks, the ink applying device has four recording heads for ejecting each of the four types of CMYK inks. These recording heads are arranged along the X direction.

[5] Liquid Absorbing Device The liquid absorbing device 105 includes a liquid absorbing member 105a and a pressing member 105b for liquid absorption that presses the liquid absorbing member 105a against the intermediate image of the transfer body 101. When the cylindrical pressing member 105b and the belt-shaped liquid absorbing member 105a are formed, the liquid component can be absorbed from the intermediate image by pressing the liquid absorbing member 105a against the transfer body 101 with the pressing member 105b. Further, the liquid component can be absorbed from the intermediate image by pressing the columnar pressing member having the liquid absorbing member attached to the outer peripheral surface against the transfer body. Considering the space in the recording device and the like, the shape of the liquid absorbing member 105a is preferably a belt shape. The liquid absorbing device 105 having the belt-shaped liquid absorbing member 105a may have a tensioning member such as a tensioning roller 105c that stretches the liquid absorbing member 105a.

By bringing the liquid absorbing member 105a including the porous layer into contact with the intermediate image using the pressing member 105b, the liquid component contained in the intermediate image can be absorbed by the liquid absorbing member 105a. As a method of absorbing the liquid component contained in the intermediate image, in addition to the method of contacting the liquid absorbing member, a method of heating, a method of blowing low humidity air, a method of reducing the pressure, and the like may be combined. In addition, these methods may be applied to the intermediate images before and after absorbing the liquid component.

The liquid absorbing member 105a rotates in conjunction with the rotation of the transfer body 101. Therefore, the shape of the liquid absorbing member 105a is preferably a shape capable of repeatedly absorbing liquid, and specific examples thereof include an endless belt shape and a drum shape. The liquid component absorbed by the liquid absorbing member 105a including the porous layer is absorbed from the liquid absorbing member 105a by a method of absorbing from the back surface of the porous layer or a method of using a member that squeezes the porous member by compressing it. Can be removed. After removing the liquid component, the liquid absorbing member 105a is rotated to bring it into contact with the new intermediate image, so that the liquid component contained in the intermediate image can be efficiently absorbed.

[6] Pressing Member The recording apparatus of the present invention includes a transfer means for transferring an intermediate image in contact with a recording medium. Specifically, as shown in FIG. 1, the intermediate image after removing the liquid on the transfer body 101 is brought into contact with the recording medium 108 conveyed by the recording medium transfer device 107 by the pressing member 106 at the transfer unit 111 to be transferred. do. By transferring the intermediate image after removing the liquid component to the recording medium 108, curling and cockling of the recording medium 108 can be suppressed.

The pressing member 106 preferably has an appropriate structural strength from the viewpoint of transport accuracy and durability of the recording medium 108. Examples of the material of the pressing member 106 include metal, ceramic, and resin. Among them, a metal such as aluminum is preferable from the viewpoint of not only having rigidity and dimensional accuracy that can withstand stress during transfer, but also reducing inertia during operation and improving control responsiveness.

When the intermediate image is transferred to the recording medium 108, the time (pressing time) for the pressing member 106 to press the transfer body 101 is preferably 5 ms or more and 100 ms or less. By setting the pressing time as described above, transfer can be performed satisfactorily and damage to the transfer body 101 can be suppressed. The pressing time is the time during which the recording medium 108 and the transfer body 101 are in contact with each other. The pressing time can be calculated by measuring the surface pressure using a pressure distribution measuring system and dividing the length of the pressurized region in the transport direction by the transport speed. Specifically, a surface pressure distribution measurement system (trade name "I-SCAN", manufactured by Nitta Corporation) or the like can be used.

When the intermediate image is transferred to the recording medium 108, the pressure (pressing pressure) at which the pressing member 106 presses the transfer body 101 is 9.8 N / cm ² (1 kg / cm ² ) or more and 294.2 N / cm ² (30 kg). / Cm ² ) or less is preferable. By applying the above pressing pressure, transfer can be performed satisfactorily and damage to the transfer body 101 can be suppressed. The pressing force is the nip pressure of the recording medium 108 and the transfer body 101. The pressing force can be calculated by measuring the surface pressure using a pressure distribution measuring system and dividing the load in the pressurized region by the area. Specifically, a surface pressure distribution measurement system (trade name "I-SCAN", manufactured by Nitta Corporation) or the like can be used.

The temperature at which the pressing member 106 presses the transfer body 101 is preferably a temperature equal to or higher than the glass transition point (or softening point) of the resin component contained in the intermediate image. Although it depends on the characteristics of the resin component, in order to control the temperature, the recording device preferably includes a heating means for heating the intermediate image on the transfer body 101, the transfer body 101, and the recording medium 108. Examples of the shape of the pressing member 106 include a roller shape and the like.

[7] Recording medium As the recording medium 108, any known recording medium can be used. Examples of the recording medium include a long object wound in a roll shape; a single-wafer object cut into a predetermined size, and the like. Examples of the constituent material of the recording medium include paper such as coated paper and plain paper; film such as plastic and metal; wooden board; corrugated cardboard and the like.

[8] Recording medium transport device The recording medium transport device 107 that transports the recording medium 108 transports the recording medium 108 in the direction of arrow C. The recording medium conveying device 107 is composed of a recording medium feeding roller 107a and a recording medium winding roller 107b. The transport speed of the recording medium 108 is preferably determined in consideration of the speed required in each step.

[9] Cleaning device As shown in FIG. 1, the recording device of the present invention has a cleaning device which is a cleaning means for applying an aqueous cleaning liquid to the transfer body 101 for cleaning. The cleaning device includes, for example, a transfer body cleaning member 109 that applies a cleaning solution to the transfer body 101 for cleaning. By cleaning the transfer body 101 with the transfer body cleaning member 109, deterioration of image quality can be suppressed. As the transfer body cleaning member 109, a member having a shape such as a roller or a web can be used. The cleaning device may be provided with a cleaning liquid supply unit that supplies the cleaning liquid to the transfer body cleaning member 109.

Further, the cleaning device preferably includes a cleaning liquid removing member 110 that removes the cleaning liquid remaining on the transfer body 101 after cleaning. By removing the cleaning liquid and the like remaining on the transfer body 101 by the cleaning liquid removing member 110, deterioration of image quality can be suppressed more effectively. Examples of the method for removing the cleaning liquid remaining on the transfer body 101 include blade removal, brush removal, and liquid absorption by the absorber. Above all, it is preferable to remove the cleaning liquid remaining on the transfer body 101 by the liquid absorption by the absorber. As the cleaning liquid removing member 110, a porous body or the like used as a liquid absorbing member can be used.

(Reaction solution)
The recording method of the present invention includes a reaction solution applying step of applying an aqueous reaction solution containing a reactant that reacts with an aqueous ink to a transcript. Hereinafter, each component and the like used in the reaction solution will be described in detail.

[Reactant]
The reaction solution reacts with the ink when it comes into contact with the ink, and aggregates the components (components having anionic groups such as resin and self-dispersing pigment) in the ink, and contains a reactant. Examples of the reactant include a cationic component such as a polyvalent metal ion and a cationic resin, and an organic acid. Among them, the reactant is preferably an organic acid, and more preferably a divalent or higher polyvalent carboxylic acid (may be a salt or a hydrogen salt).

Examples of polyvalent metal ions include divalent metal ions ^{such as Ca 2+} , Cu ²⁺ , Ni ²⁺ , Mg ²⁺ , Sr ²⁺ , Ba ²⁺ , and Zn ^{2+ , Fe 3+} , Cr ³⁺ , Y ³⁺ , and Al. Trivalent metal ions such as ^{3+ can be mentioned.} In order to contain the polyvalent metal ion in the reaction solution, a polyvalent metal salt (which may be a hydrate) formed by bonding the polyvalent metal ion and the anion can be used. Examples of anions include Cl ⁻ , Br ⁻ , I ⁻ , ClO ⁻ , ClO ₂ ⁻ , ClO ₃ ⁻ , ClO ₄ ⁻ , NO ₂ ⁻ , NO ₃ ⁻ , SO ₄ ^2- , CO ₃ ^2- , and HCO ₃ Inorganic anions such as ⁻ , PO ₄ ^3- , HPO ₄ ^2- , and H ₂ PO ₄ ^{− ; HCOO −} , (COO ⁻ ) ₂ , COOH (COO ⁻ ), CH ₃ COO ⁻ , C ₂ H ₄ (COO ⁻⁾ ) ₂ , C ₆ H ₅ COO ⁻ , C ₆ H ₄ (COO ⁻ ) ₂ , and CH ₃ SO ₃ ⁻ and other organic anions can be mentioned. When polyvalent metal ions are used as the reactant, the content (% by mass) in terms of polyvalent metal salt in the reaction solution is 1.0% by mass or more and 20.0% by mass or less based on the total mass of the reaction solution. It is preferable to have.

The reaction solution containing an organic acid has a buffering capacity in an acidic region (pH less than 7.0, preferably pH 2.0 to 5.0), so that the anionic group of the component existing in the ink can be efficiently acidified. It is to be aggregated. Examples of organic acids include formic acid, acetic acid, propionic acid, butyric acid, benzoic acid, glycolic acid, lactic acid, salicylic acid, pyrrolcarboxylic acid, furancarboxylic acid, picolinic acid, nicotinic acid, thiophenecarboxylic acid, levulinic acid, coumarin acid and the like. Monocarboxylic acids and salts thereof; dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, itaconic acid, sebacic acid, phthalic acid, malic acid, tartrate acid, and salts thereof. And hydrogen salts; tricarboxylic acids such as citric acid and trimellitic acid and their salts and hydrogen salts; tetracarboxylic acids such as pyromellitic acid and their salts and hydrogen salts. The content (mass%) of the organic acid in the reaction solution is preferably 1.0% by mass or more and 50.0% by mass or less based on the total mass of the reaction solution.

Examples of the cationic resin include a resin having a structure of a primary amine and a resin having a structure of a quaternary ammonium salt. Specific examples thereof include resins having structures such as vinylamine, allylamine, vinylimidazole, vinylpyridine, dimethylaminoethyl methacrylate, ethyleneimine, and guanidine. In order to increase the solubility in the reaction solution, the cationic resin and the acidic compound can be used in combination, or the cationic resin can be quaternized. When a cationic resin is used as the reactant, the content (mass%) of the cationic resin in the reaction solution may be 1.0% by mass or more and 10.0% by mass or less based on the total mass of the reaction solution. preferable.

[wax]
The reaction solution further contains particulate wax (hereinafter, also referred to as "wax particles" or simply "wax"). By using the reaction solution containing wax, the wax can be present on the surface of the image recorded by the transfer method, and the fastness of the image can be improved. However, in order to repeatedly record a high-quality image without missing dots or white spots, it is necessary to wash and remove the wax remaining on the transfer body after transfer. Therefore, it is effective to use a wax that is easily removed by the cleaning liquid, that is, has good redispersibility in the cleaning liquid. Such a wax is a particulate wax obtained by emulsifying a polyolefin wax with a nonionic emulsifier and an anionic emulsifier. The nonionic emulsifier is a polyoxyethylene alkyl ether having an HLB value of 13.6 or more and 15.9 or less, and the anionic emulsifier is a sulfate ester-based interface having an alkyl group having 8 or more and 18 or less carbon atoms. It is an activator.

Polyoxyethylene alkyl ethers whose HLB values are within a certain range interact strongly with polyolefin waxes. Furthermore, this polyoxyethylene alkyl ether suppresses aggregation of wax particles even when the liquid components on the transfer material are reduced due to evaporation or the like due to the steric repulsion of the nonionic group and the wax particles are close to each other. Shows the effect of Therefore, by using a reaction solution containing the particulate wax obtained by emulsifying the polyolefin wax with the above-mentioned polyoxyethylene alkyl ether, it is possible to prevent the wax from strongly adhering to the transcript.

Further, the sulfate ester-based surfactant having an alkyl group whose carbon number is within a specific range strongly interacts with the polyolefin wax. Furthermore, since this sulfate ester-based surfactant has a sulfonic acid group in its molecule, it is possible to improve the compatibility between the wax remaining on the transfer body and the aqueous cleaning liquid. Therefore, by using a reaction solution containing a particulate wax obtained by emulsifying a polyolefin wax with the above-mentioned sulfate ester-based surfactant, the redispersibility of the wax in the cleaning solution is enhanced, and the residual wax can be easily removed from the transfer material. Can be removed.

It is assumed that wax particles obtained by emulsifying polyolefin wax with only an anionic emulsifier (specific sulfate ester-based surfactant) are used without using a nonionic emulsifier (specific polyoxyethylene alkyl ether). In this case, the aggregation of the wax particles on the transfer body cannot be suppressed, and the wax particles tend to adhere firmly to the transfer body, which makes it difficult to remove the wax particles by washing. Further, it is assumed that wax particles obtained by emulsifying polyolefin wax only with a nonionic emulsifier (specific polyoxyethylene alkyl ether) are used without using an anionic emulsifier (specific sulfate ester-based surfactant). In this case, since the wax and the cleaning liquid become difficult to be compatible with each other, the redispersibility of the wax in the cleaning liquid is lowered, and it becomes difficult to remove the residual wax from the transfer body. Therefore, by using a reaction solution containing a wax obtained by emulsifying a polyolefin wax in combination with a specific polyoxyethylene alkyl ether and a sulfate ester-based surfactant, it is easy to remove the wax that is a residue from the transfer material. Can be removed. Since the residue can be easily removed from the transfer body, it is possible to suppress the deterioration of image quality that occurs when the image is repeatedly recorded.

[Polyolefin wax]
As the polyolefin wax, for example, a polyolefin wax which is a polymer of α-olefin such as ethylene, propylene, 1-butene, 1-pentene, and 1-hexene can be used. Specific examples of the polyolefin wax include polyolefin oxide wax, high-density polyolefin wax, a mixture of polyolefin oxide wax and paraffin wax, and a copolymer of polyolefin and acrylic. Of these, polyethylene oxide wax and polypropylene oxide wax are preferably used. The content (mass%) of the polyolefin wax in the reaction solution is preferably 5.0% by mass or more and 30.0% by mass or less based on the total mass of the reaction solution. If the content of the polyolefin wax is less than 5.0% by mass, the effect of improving the scratch resistance of the image may be slightly reduced.

The 50% particle size (D50) of the particulate wax (wax particles) in the reaction solution based on the volume distribution is preferably 20 nm or more and 200 nm or less. If the particle size (D50) of the wax particles is less than 20 nm, the particle size is too small, and the effect of improving the scratch resistance of the image may be slightly reduced. On the other hand, if the particle size (D50) of the wax particles is more than 200 nm, the particle size is too large, and the quality of the image may be slightly deteriorated. The particle size (D50) of the wax particles can be measured using, for example, a particle size analyzer based on a dynamic light scattering method.

[Nonionic emulsifier]
The polyoxyethylene alkyl ether used as a nonionic emulsifier is a kind of surfactant and is represented by the general formula: R _{1 −} O − (CH ₂ CH ₂ O) _{n −} H. In the general formula, R ₁ represents a hydrocarbon group and n represents the number of repetitions of an ethylene oxide group. The _{hydrocarbon group represented by R 1} may be either a straight chain or a branched chain, and may be saturated or unsaturated. The polyoxyethylene alkyl ether preferably has an alkyl group having 6 or more and 30 or less carbon atoms, and more preferably 12 or more and 22 or less. The number of repetitions of the ethylene oxide group of the polyoxyethylene alkyl ether (value of n in the above general formula) is preferably 5 or more and 50 or less, and more preferably 9 or more and 30 or less. By using such a polyoxyethylene alkyl ether, the wax remaining on the transcript can be removed more easily.

The content (mass%) of the nonionic emulsifier (polyoxyethylene alkyl ether) in the reaction solution is preferably 0.10% by mass or more and 1.00% by mass or less based on the total mass of the reaction solution. The HLB value of polyoxyethylene alkyl ether is 13.6 or more and 15.9 or less. If the HLB value of the polyoxyethylene alkyl ether is less than 13.6 or more than 15.9, the wax remaining on the transcript cannot be effectively removed. The HLB value of the polyoxyethylene alkyl ether is a value calculated by the following formula (1), which is obtained by the Griffin method. The HLB value obtained by the Griffin method is a physical property value indicating the degree of hydrophilicity and lipophilicity of the nonionic surfactant, and takes a value of 0.0 to 20.0. The smaller the HLB value, the higher the lipophilicity, and the larger the HLB value, the higher the hydrophilicity.
HLB value = 20 x formula amount of ethylene oxide group of surfactant / molecular weight of surfactant ... (1)

[Anionic emulsifier]
Sulfuric ester surfactant used as the anionic emulsifier, the general formula: alkyl sulfuric ester represented by R 2 _-O-SO 3 _M. In the general formula, R ₂ represents an alkyl group and M represents a hydrogen atom, alkali metal, ammonium, or organic ammonium. The sulfate ester-based surfactant has an alkyl group having 8 or more and 18 or less carbon atoms, preferably an alkyl group having 12 or more and 16 or less carbon atoms. The alkyl group (R ₂ in the general formula) may be either a straight chain or a branched chain. If the alkyl group has less than 8 or more than 18 carbon atoms, the wax remaining on the transcript cannot be effectively removed. The content (mass%) of the anionic emulsifier (sulfuric acid ester-based surfactant) in the reaction solution is preferably 0.01% by mass or more and 0.50% by mass or less based on the total mass of the reaction solution.

[Mass ratio of each component]
The total content (mass%) of the nonionic emulsifier and the anionic emulsifier in the reaction solution is preferably 0.20 times or more and 0.50 times or less in terms of the mass ratio with respect to the content (mass%) of the polyolefin wax. .. By setting the mass ratio as described above, the removability of the wax remaining on the transfer material can be further enhanced. The content (mass%) of the anionic emulsifier in the reaction solution is preferably 0.03 times or more and 0.50 times or less in terms of the mass ratio with respect to the content (mass%) of the nonionic emulsifier. By setting the mass ratio as described above, the removability of the wax remaining on the transfer material can be further enhanced.

[Other ingredients]
The reaction solution may contain various other components, if necessary. Examples of other components include those similar to the aqueous medium described later and other additives that can be contained in the ink.

(ink)
The ink used in the recording method of the present invention is preferably a water-based ink for inkjet containing a coloring material. Hereinafter, each component used in the ink and the like will be described in detail.

[Color material]
Pigments and dyes can be used as the coloring material to be contained in the ink. The content (mass%) of the coloring material in the ink is preferably 0.5% by mass or more and 15.0% by mass or less, and 1.0% by mass or more and 10.0% by mass, based on the total mass of the ink. The following is more preferable.

Specific examples of the pigment include inorganic pigments such as carbon black and titanium oxide; and organic pigments such as azo, phthalocyanine, quinacridone, isoindolinone, imidazolone, diketopyrrolopyrrole, and dioxazine.

As a pigment dispersion method, a resin-dispersed pigment using a resin as a dispersant, a self-dispersing pigment in which a hydrophilic group is bonded to the particle surface of the pigment, or the like can be used. Further, a resin-bonded pigment in which an organic group containing a resin is chemically bonded to the surface of the pigment particles, a microcapsule pigment in which the surface of the pigment particles is coated with a resin or the like can be used. Of these, it is preferable to use a resin-dispersed pigment in which a resin as a dispersant is physically adsorbed on the particle surface of the pigment, instead of a resin-bound pigment or a microcapsule pigment.

As the resin dispersant for dispersing the pigment in the aqueous medium, it is preferable to use a resin dispersant capable of dispersing the pigment in the aqueous medium by the action of an anionic group. As the resin dispersant, a resin as described later, particularly a water-soluble resin can be used. The content (mass%) of the pigment in the ink is preferably 0.3 times or more and 10.0 times or less in terms of the mass ratio with respect to the content of the resin dispersant.

As the self-dispersing pigment, an anionic group such as a carboxylic acid group, a sulfonic acid group, or a phosphonic acid group is used which is bonded to the particle surface of the pigment directly or via another atomic group (-R-). be able to. The anionic group may be of either an acid type or a salt type, and when it is a salt type, it may be in a state in which a part thereof is dissociated or a state in which all of the anionic group is dissociated. When the anionic group is a salt type, examples of the cation that becomes a counter ion include alkali metal cations, ammonium, and organic ammonium. Specific examples of other atomic groups (-R-) include a linear or branched alkylene group having 1 to 12 carbon atoms; an arylene group such as a phenylene group or a naphthylene group; a carbonyl group; an imino group; an amide group; a sulfonyl group. Group; ester group; ether group and the like can be mentioned. Further, it may be a group in which these groups are combined.

As the dye, it is preferable to use a dye having an anionic group. Specific examples of the dye include dyes such as azo, triphenylmethane, (aza) phthalocyanine, xanthene, and anthrapyridone. The coloring material contained in the ink used in the recording method of the present invention is preferably a pigment, and more preferably a resin-dispersed pigment.

[resin]
The ink can contain a resin. The content (mass%) of the resin in the ink is preferably 0.1% by mass or more and 20.0% by mass or less, and 0.5% by mass or more and 15.0% by mass or less, based on the total mass of the ink. Is more preferable.

The resin can be added to the ink in order to (i) stabilize the dispersed state of the pigment, that is, as a resin dispersant or an auxiliary thereof. In addition, (ii) can be added to the ink in order to improve various characteristics of the recorded image. Examples of the form of the resin include block copolymers, random copolymers, graft copolymers, and combinations thereof. Further, the resin may be a water-soluble resin that can be dissolved in an aqueous medium, or may be resin particles dispersed in the aqueous medium. The resin particles do not need to contain a coloring material.

In the present specification, "the resin is water-soluble" means that when the resin is neutralized with an acid value and an equivalent amount of alkali, it is aqueous in a state where particles whose particle size can be measured by a dynamic light scattering method are not formed. It means that it exists in the medium. Whether or not the resin is water-soluble can be determined according to the method shown below. First, a liquid (resin solid content: 10% by mass) containing a resin neutralized with an alkali (sodium hydroxide, potassium hydroxide, etc.) equivalent to an acid value is prepared. Next, the prepared liquid is diluted 10-fold (volume basis) with pure water to prepare a sample solution. Then, when the particle size of the resin in the sample solution is measured by the dynamic light scattering method, if the particles having the particle size are not measured, it can be determined that the resin is water-soluble. The measurement conditions at this time can be, for example, as follows.
[Measurement condition]
SetZero: 30 seconds Number of measurements: 3 Measurement time: 180 seconds

As the particle size distribution measuring device, a particle size analyzer (for example, trade name “UPA-EX150”, manufactured by Nikkiso Co., Ltd.) by a dynamic light scattering method can be used. Of course, the particle size distribution measuring device and the measuring conditions to be used are not limited to the above.

The acid value of the water-soluble resin is preferably 100 mgKOH / g or more and 250 mgKOH / g or less. The acid value of the resin constituting the resin particles is preferably 5 mgKOH / g or more and 100 mgKOH / g or less. The weight average molecular weight of the water-soluble resin is preferably 3,000 or more and 15,000 or less. The weight average molecular weight of the resin constituting the resin particles is preferably 1,000 or more and 2,000,000 or less. The volume average particle size of the resin particles measured by the dynamic light scattering method is preferably 50 nm or more and 500 nm or less.

Examples of the resin include acrylic resins, urethane resins, and olefin resins. Of these, acrylic resins and urethane resins are preferable, and acrylic resins composed of units derived from (meth) acrylic acid and (meth) acrylate are even more preferable.

The acrylic resin preferably has a hydrophilic unit and a hydrophobic unit as constituent units. Among them, a resin having a hydrophilic unit derived from (meth) acrylic acid and a hydrophobic unit derived from at least one of a monomer having an aromatic ring and a (meth) acrylic acid ester-based monomer is preferable. In particular, a resin having a hydrophilic unit derived from (meth) acrylic acid and a hydrophobic unit derived from at least one monomer of styrene and α-methylstyrene is preferable. Since these resins are likely to interact with pigments, they can be suitably used as resin dispersants for dispersing pigments.

The hydrophilic unit is a unit having a hydrophilic group such as an anionic group. The hydrophilic unit can be formed, for example, by polymerizing a hydrophilic monomer having a hydrophilic group. Specific examples of the hydrophilic monomer having a hydrophilic group include an acidic monomer having a carboxylic acid group such as (meth) acrylic acid, itaconic acid, maleic acid, and fumaric acid, and anions such as anhydrides and salts of these acidic monomers. Examples include sex monomers. Examples of the cation constituting the salt of the acidic monomer include ions such as lithium, sodium, potassium, ammonium and organic ammonium. A hydrophobic unit is a unit that does not have a hydrophilic group such as an anionic group. The hydrophobic unit can be formed, for example, by polymerizing a hydrophobic monomer having no hydrophilic group such as an anionic group. Specific examples of the hydrophobic monomer include monomers having an aromatic ring such as styrene, α-methylstyrene, and benzyl (meth) acrylate; methyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylate 2. -Examples include (meth) acrylic acid ester-based monomers such as ethylhexyl.

The urethane resin can be obtained, for example, by reacting a polyisocyanate with a polyol. Further, the chain extender may be further reacted. Examples of the olefin resin include polyethylene and polypropylene.

[Resin particles]
The water-based ink preferably contains resin particles. By using an ink containing resin particles, transfer defects are further suppressed, and a higher quality image can be recorded. Examples of the resin particles contained in the ink include the above-mentioned acrylic resin and urethane resin. The content (mass%) of the resin particles in the ink is preferably 1.0% by mass or more and 15.0% by mass or less, and 5.0% by mass or more and 15.0% by mass or less, based on the total mass of the ink. Is more preferable.

[Aqueous medium]
The ink used in the recording method of the present invention is a water-based ink containing at least water as an aqueous medium. The ink may contain water or an aqueous medium which is a mixed solvent of water and a water-soluble organic solvent. As the water, it is preferable to use deionized water or ion-exchanged water. The water content (mass%) in the water-based ink is preferably 50.0% by mass or more and 95.0% by mass or less based on the total mass of the ink. The content (mass%) of the water-soluble organic solvent in the water-based ink is preferably 3.0% by mass or more and 50.0% by mass or less based on the total mass of the ink. As the water-soluble organic solvent, any solvent that can be used for ink jet ink such as alcohols, (poly) alkylene glycols, glycol ethers, nitrogen-containing compounds, and sulfur-containing compounds can be used.

[Other additives]
In addition to the above components, various inks such as defoamers, surfactants, pH adjusters, viscosity regulators, rust inhibitors, preservatives, fungicides, antioxidants, antioxidants, etc. Additives may be included.

(Cleaning liquid)
The cleaning solution is an aqueous cleaning solution containing at least water as an aqueous medium. Hereinafter, each component used in the cleaning liquid and the like will be described in detail.

[Aqueous medium]
The aqueous medium is water or a mixed solvent of water and a water-soluble organic solvent. As the water, it is preferable to use deionized water or ion-exchanged water. The content (mass%) of water in the cleaning liquid is preferably 70.0% by mass or more and 99.0% by mass or less, and 85.0% by mass or more and 97.0% by mass or less, based on the total mass of the cleaning liquid. Is more preferable. If the water content is too low, the effect of penetrating the interface between the residue and the transcript may be weakened, and the detergency may be slightly insufficient.

Examples of the water-soluble organic solvent that can be used in the cleaning liquid include alcohols, (poly) alkylene glycols, glycol ethers, nitrogen-containing compounds, and sulfur-containing compounds. Among them, it is preferable to use a low-polarity solvent typified by polyhydric alcohols and glycol ethers. The content (mass%) of the water-soluble organic solvent in the cleaning liquid is preferably 1.0% by mass or more and 20.0% by mass or less, and 3.0% by mass or more and 15.0% by mass, based on the total mass of the cleaning liquid. It is more preferably mass% or less.

[Surfactant]
The cleaning liquid can contain a surfactant. As the surfactant, it is preferable to use an amphoteric surfactant. As the amphoteric surfactant, N, N-dimethyldodecylamine-N-oxide is preferable. Since N, N-dimethyldodecylamine-N-oxide has a function of facilitating the diffusion of the residue in the cleaning liquid, the cleaning property can be further improved. The content (mass%) of the surfactant in the cleaning liquid is preferably 0.1% by mass or more and 5.0% by mass or less based on the total mass of the cleaning liquid.

[Other ingredients]
The cleaning liquid may contain various other components, if necessary. Examples of other components include those similar to the above-mentioned other additives that can be contained in the ink.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples as long as the gist thereof is not exceeded. Unless otherwise specified, the amounts of components described as "parts" and "%" are based on mass.

<Preparation of pigment dispersion liquid>
(Pigment dispersion liquid 1)
A styrene-ethyl acrylate-acrylic acid copolymer (resin 1) having an acid value of 150 mgKOH / g and a weight average molecular weight of 8,000 was prepared. After neutralizing 20.0 parts of resin 1 with potassium hydroxide having an acid value equal to the mole, an appropriate amount of pure water is added, and an aqueous solution of resin 1 having a resin (solid content) content of 20.0% is added. Was prepared. 10.0 parts of the pigment (CI Pigment Blue 15: 3), 15.0 parts of the aqueous solution of the resin 1 and 75.0 parts of pure water were mixed to obtain a mixture. The obtained mixture and 200 parts of 0.3 mm diameter zirconia beads were placed in a batch type vertical sand mill (manufactured by Imex) and dispersed for 5 hours while cooling with water. After centrifuging to remove coarse particles, pressure filtration is performed with a cellulose acetate filter (manufactured by Advantech) having a pore size of 3.0 μm, and the pigment content is 10.0% and the resin dispersant (resin 1) is contained. A pigment dispersion 1 having an amount of 3.0% was prepared.

(Pigment dispersion liquid 2)
Pigment C.I. I. Pigment dispersion with a pigment content of 10.0% and a resin dispersant (resin 1) content of 3.0% in the same procedure as the pigment dispersion liquid 1 described above, except that the pigment was changed to Pigment Red 122. Liquid 2 was prepared.

(Pigment dispersion liquid 3)
Pigment C.I. I. Pigment dispersion with a pigment content of 10.0% and a resin dispersant (resin 1) content of 3.0% in the same procedure as the pigment dispersion liquid 1 described above, except that the pigment was changed to Pigment Yellow 74. Liquid 3 was prepared.

(Pigment dispersion liquid 4)
A pigment having a pigment content of 10.0% and a resin dispersant (resin 1) content of 3.0% in the same procedure as the pigment dispersion liquid 1 described above, except that the pigment was changed to carbon black. The dispersion 4 was prepared.

<Preparation of resin particles>
74.0 parts of ion-exchanged water and 0.2 part of potassium persulfate were placed in a four-necked flask equipped with a stirrer, a reflux cooling device, and a nitrogen gas introduction tube and mixed. In addition, 24.0 parts of ethyl methacrylate, 1.5 parts of methacrylic acid, and 0.3 part of a reactive surfactant (trade name "Aqualon KH-05", manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) are mixed to prepare an emulsion. bottom. Under a nitrogen atmosphere, the prepared emulsion was added dropwise to the above-mentioned four-necked flask over 1 hour, and the polymerization reaction was carried out for 2 hours with stirring at 80 ° C. After cooling to 25 ° C., ion-exchanged water and an aqueous solution containing potassium hydroxide having an acid value equal to that of the resin particles are added to the resin particles having a resin particle (solid content) content of 25.0%. Water dispersion was prepared.

<Ink preparation>
Each component (unit:%) shown in Table 1 was mixed, sufficiently stirred, and then pressure-filtered with a cellulose acetate filter (manufactured by Advantech) having a pore size of 3.0 μm to prepare each ink. In Table 1, the "aqueous solution of resin 1" is the same as the "aqueous solution of resin 1" used for preparing the pigment dispersion liquid. The numerical value attached to polyethylene glycol is the number average molecular weight of polyethylene glycol. "Acetyleneol E100" is a trade name of a surfactant manufactured by Kawaken Fine Chemicals.

<Preparation of wax particles>
(Preparation of nonionic emulsifier)
Nonionic emulsifiers (linear polyoxyethylene alkyl ethers) of the types shown in Table 2 were prepared.

(Preparation of anionic emulsifier)
Anionic emulsifiers of the types shown in Table 3 (sodium salt of alkyl sulfate ester or sodium salt of alkyl phosphate ester) were prepared.

(Preparation of wax particles)
[Wax particles 1-52]
Each component shown in Tables 4-1 and 4-2 was mixed, and the temperature and pressure were appropriately adjusted to emulsify the wax to prepare wax particles having a predetermined particle size. An appropriate amount of pure water was added to prepare a liquid containing wax particles 1 to 52 having a total content of wax and emulsifier of 35.0%.

<Preparation of reaction solution>
Each of the following components was mixed and sufficiently stirred, and then pressure filtration was performed with a cellulose acetate filter (manufactured by Advantech) having a pore size of 3.0 μm to prepare each reaction solution. "Mega Fvck F444" is a trade name of a fluorine-based surfactant manufactured by DIC. Wax content W (%) of each prepared reaction solution, nonionic emulsifier content N (%), anionic emulsifier content A (%), (N + A) / W value (times), and A The value (times) of / N is shown in Tables 5-1 and 5-2.
Liquid containing wax particles of the types shown in Tables 5-1 and 5-2: 20.00%
・ Malic acid: 30.00%
・ Glycerin: 7.00%
・ Mega Fvck F444: 5.00%
-Ion-exchanged water: 38.00%

<Preparation of cleaning solution>
Each of the following components was mixed and sufficiently stirred, and then pressure filtration was performed with a cellulose acetate filter (manufactured by Advantech) having a pore size of 3.0 μm to prepare a cleaning solution.
-1,2-Hexanediol: 5.0%
・ Ion-exchanged water: 95.0%

<Preparation of porous body>
The emulsion-polymerized particles of the crystallized fluororesin (polytetrafluoroethylene) were compression-molded and then stretched at a temperature equal to or lower than the melting point to prepare a fibrillated porous layer (first layer). Further, polyethylene and polypropylene were mixed and then stretched by a wet method to prepare a fibrillated porous layer (second layer). Further, a polyolefin-based non-woven fabric (trade name "HOP60", manufactured by Hirose Paper Co., Ltd.) was used as the third layer. The thickness of the second layer is thicker than that of the first layer. Further, the average pore diameter is smaller in the second layer than in the first layer. The first layer, the second layer, and the third layer were hot-pressure laminated and adhered to obtain a porous body.

<Evaluation>
The reaction solution, the ink, and the cleaning solution were filled into the reaction solution application device 103, the ink application device 104, and the cleaning member 109 of the transfer type inkjet recording device 100 having the configuration shown in FIG. 1, respectively. The configuration of the transfer type inkjet recording device 100 used is shown below. As the support member 102, a cylindrical drum made of an aluminum alloy was used. A surface layer member (surface layer containing a siloxane compound) of the transfer body 101 was prepared by the following procedure.

A mixture was obtained by mixing 50 mol% of a hydrolyzable organic silane compound (diethyldiethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.) and 50 mol% of an organic silane compound (diethyldiethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.). Water and acetic acid (catalyst) were added to the resulting mixture. Acetic acid was added so as to be 500 ppm based on the total mass. Then, the mixture was heated under reflux for 24 hours or more to obtain a solution containing a condensed compound formed by dehydration condensation of an organic silane compound. A mixed solvent of ethanol and methyl isobutyl ketone (mass ratio 4: 1) was added and diluted to 27%. Further, a photocationic polymerization initiator (trade name "CPI-410S", manufactured by San-Apro) was added in an amount of 3 mol% based on the solid content to prepare a coating liquid.

As the base material of the transfer body, a polyethylene terephthalate film having a thickness of 0.05 mm coated with silicone rubber having a rubber hardness of 40 degrees to a thickness of 0.2 mm was prepared. The prepared coating liquid was applied to the prepared base material by spin coating, and a thin film-like surface layer was provided on the surface of the base material. After exposure using a UV lamp, the surface layer was cured by heating at 120 ° C. for 2 hours. As a result, a transcript 101 having a layer formed of a resin having a siloxane structure was obtained. The transfer body 101 obtained by using the double-sided adhesive tape was fixed to the support member 102.

The reaction solution was applied onto the transcript 101 at a concentration of 1.0 g / m ² using the reaction solution application device 103. A recording head of a type that ejects ink by an on-demand method equipped with an electric-heat conversion element was used as an ink applying device 104, and ink was applied to a region of the transfer body 101 to which a reaction solution was applied.

The above-mentioned porous body was used as the liquid absorbing member 105a. The moving speed of the liquid absorbing member 105a was adjusted by controlling the rotating speed of the tension roller 105c so as to be the same as the rotating speed of the transfer body 101. The moving speed of the liquid absorbing member 105a was set to 0.4 m / sec. The liquid absorbing member 105a is immersed in a liquid containing 95.0 parts of ethanol and 5.0 parts of water to allow the liquid to permeate into the voids of the porous body, and then the voids are replaced with water and used for liquid removal. bottom. A pressure was applied to the pressing member 105b so that the nip pressure (average pressure) between the transfer body 101 and the liquid absorbing member 105a was 2 kg / cm ^2.

The recording medium 108 was conveyed by driving the recording medium feeding roller 107a and the recording medium winding roller 107b so as to have a speed equivalent to the rotation speed of the transfer body 101. The recording medium 108 and the intermediate image were brought into contact with each other between the transfer body 101 and the pressing member 106, and the intermediate image was transferred from the transfer body 101 to the recording medium 108 to record a solid image. As the recording medium 108, coated paper (trade name “Aurora Coat”, manufactured by Nippon Paper Industries, Basis weight 104 g / m ² ) was used. The nip pressure between the transfer body 101 and the pressing member 106 was adjusted to ^{3 kg / cm 2.}

The cleaning member 109 supplied with the cleaning liquid supplied from the cleaning liquid storage unit (not shown) was used to apply the cleaning liquid to the transfer body 101. Then, the cleaning liquid was removed from the transfer body 101 using the cleaning liquid removing member 110. As the cleaning liquid removing member 110, a member made of the same material as the produced porous body was used.

Using the transfer type inkjet recording apparatus 100 having the above configuration, using cyan, magenta, yellow, and black inks, a total of 100 recording media containing patterns containing solid images of four colors of 5 cm × 5 cm. Recorded in. In the transfer type inkjet recording apparatus 100, an image recorded under the condition that one drop of 3.0 ng of ink is applied to a unit area of 1/1, 200 inch × 1/1, 200 inch has a recording duty of 100%. Is defined as. Observe the state of missing dots and white spots in the image (pattern) recorded on the 100th recording medium visually and with a microscope, evaluate the suppression of missing dots and white spots in the image according to the evaluation criteria shown below, and transfer. It was used as an index of body cleansing. In the present invention, "AA", "A", and "B" are acceptable levels, and "C" is an unacceptable level in the evaluation criteria of the following items. The evaluation results are shown in Table 5.
AA: Neither white spots nor missing dots occurred in the image.
A: There was no white spot in the image, but there were some missing dots.
B: Both white spots and missing dots occurred in the image, but they could not be visually recognized.
C: Both white spots and missing dots occurred in the image, which could be visually recognized.

Claims (4)

An inkjet recording method for recording an image on a recording medium using water-based ink.
A reaction solution applying step of applying an aqueous reaction solution containing a reactant that reacts with the aqueous ink to the transfer product, and a reaction solution applying step.
An intermediate image forming step of applying the water-based ink to a transfer body to form an intermediate image,
A transfer step of bringing the intermediate image into contact with the recording medium and transferring the image,
A cleaning step of applying an aqueous cleaning solution to the transfer body to clean the transfer body is provided in this order.
The reaction solution further contains a particulate wax obtained by emulsifying a polyolefin wax with a nonionic emulsifier and an anionic emulsifier.
The nonionic emulsifier is a polyoxyethylene alkyl ether having an HLB value of 13.6 or more and 15.9 or less.
An inkjet recording method, wherein the anionic emulsifier is a sulfuric acid ester-based surfactant having an alkyl group having 8 or more and 18 or less carbon atoms. The polyoxyethylene alkyl ether has an alkyl group having 12 or more and 22 or less carbon atoms.
The number of repetitions of the ethylene oxide group of the polyoxyethylene alkyl ether is 9 or more and 30 or less.
The inkjet recording method according to claim 1, wherein the sulfate ester-based surfactant has an alkyl group having 12 or more and 16 or less carbon atoms. The total content (mass%) of the nonionic emulsifier and the anionic emulsifier in the reaction solution is 0.20 times or more and 0.50 times or less in terms of the mass ratio with respect to the content (mass%) of the polyolefin wax. can be,
1. 2. The inkjet recording method according to 2. An inkjet recording device used to record an image on a recording medium using water-based ink.
A reaction solution-imparting means for applying an aqueous reaction solution containing a reactant that reacts with the water-based ink to the transcript, and a reaction solution-imparting means.
An ink applying means for forming an intermediate image by ejecting the water-based ink to a transfer body by an inkjet method.
A transfer means for bringing the intermediate image into contact with the recording medium for transfer,
A cleaning means for applying an aqueous cleaning solution to the transfer body to clean the transfer body is provided.
The reaction solution further contains a particulate wax obtained by emulsifying a polyolefin wax with a nonionic emulsifier and an anionic emulsifier.
The nonionic emulsifier is a polyoxyethylene alkyl ether having an HLB value of 13.6 or more and 15.9 or less.
An inkjet recording apparatus, wherein the anionic emulsifier is a sulfate ester-based surfactant having an alkyl group having 8 or more and 18 or less carbon atoms.

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