JP6645049B2 - Inkjet recording method - Google Patents

Description

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

  2. Description of the Related Art Conventionally, there has been known an ink jet recording method in which minute ink droplets are ejected from nozzles of a recording head of an ink jet recording apparatus to record an image on a recording medium. In recent years, the ink jet recording method has been used not only for recording an image on a recording medium having excellent ink absorbency (for example, plain paper), but also for a recording medium having a low ink absorbency (low absorbency) (for example, art paper). , Coated paper, etc.) and recording media that hardly absorb (non-absorbing) ink (eg, plastic films, etc.). Also, from the viewpoints of the global environment and safety, the use of water-based water-based inks has been studied for inks used for recording images on such low-absorbing or non-absorbing recording media. ing.

  The water-based ink has a property of being easily repelled on a low-absorbing recording medium or a non-absorbing recording medium as compared with a non-aqueous ink based on an organic solvent. Therefore, with respect to a low-absorbing or non-absorbing recording medium, a recorded image tends to have color unevenness or the like. From such a viewpoint, for example, it has been attempted to react a reaction liquid containing a polyvalent metal salt or the like with an aqueous (aqueous) ink composition on a low-absorbing recording medium (Patent Document 1). -3).

JP-A-2009-226851 JP 2013-071277 A JP 2006-507159 A

  As described above, by using the reaction liquid and bringing the ink into contact with the ink on the recording medium, it is considered that problems such as bleeding of the ink in the image are suppressed. However, Patent Documents 1-3 disclose that the smaller the water content (the amount of water after drying) of the applied reaction liquid, the better. In general, it is expected that after the reaction liquid is applied, the reaction liquid is sufficiently dried and then the colored ink is applied to obtain an image having good fixability. It is thought that they tried to dry the liquid.

  If a colored ink is applied to this without drying the reaction liquid, sufficient adhesion between the components of the ink and the recording medium may not be obtained, and the abrasion resistance (fixing property) may be insufficient. That is, if the coloring ink is applied while the reaction liquid is wet, the coloring ink may coagulate too early, and may be fixed in a state where the coloring ink does not sufficiently contact the recording medium. It is feared that the fixability of the coating film is reduced due to the decrease in the fixability.

  However, if the ink is applied to the location before the reaction liquid dries, the aggregation of the ink components and / or the thickening of the ink more effectively occurs, the ink components become granular, and the coloring property is reduced. Then it becomes more advantageous. In the techniques of Patent Documents 1-3, priority is given to ensuring fixability, and it is considered that the color developability cannot always be sufficiently improved.

Further, in order to dry the reaction liquid, the recording medium is easily heated to cause clogging of the recording head, and the time required for drying is also required, and a zone and a drying means for drying the recording medium are included in the apparatus. This is not preferable in terms of miniaturization. Therefore, recording the ink immediately without providing a step of drying the reaction liquid is advantageous in increasing the recording speed, eliminating the drying zone, making the apparatus compact, and eliminating the adverse effect on the head due to platen heating.

  One of the objects according to some aspects of the present invention is to provide an ink jet recording method and an ink jet recording apparatus which have excellent fixability to a recording medium and can stably record an image in which printing unevenness is suppressed. To provide.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

[Application Example 1] One embodiment of the inkjet recording method according to the present invention is as follows.
A reaction liquid adhering step of adhering a reaction liquid containing a reactant for aggregating or thickening the components of the coloring ink containing the coloring material to the recording medium,
A colored ink adhering step of adhering the colored ink to an area where the reaction liquid is adhered by an inkjet method in a state where the residual ratio of the volatile component of the reaction liquid adhered to the recording medium is 25% by mass or more,
After the colored ink attaching step, or at the same time as the colored ink attaching step, a clear ink attaching step of attaching a clear ink containing a resin to the area where the reaction liquid is attached,
including.

  According to the inkjet recording method of this application example, it is possible to record an image with excellent fixability and suppressed print unevenness on a recording medium with high stability. That is, an image having good fixability of the aggregate to the recording medium can be formed by the resin of the clear ink.

[Application Example 2] In Application Example 1,
The recording medium may be a low-absorbing recording medium or a non-absorbing recording medium.

  According to the inkjet recording method of this application example, when the colored ink adheres, the reaction liquid having a high residual ratio of the volatile component is likely to remain on the surface of the recording medium, so that it is possible to form an image having better coloration. it can. That is, according to the inkjet recording method of this application example, when the colored ink comes into contact with the reaction liquid containing a large amount of volatile components, the coloring material is aggregated in a granular form, so that the color developability is good.

[Application Example 3] In Application Example 1 or Application Example 2,
The coloring ink may be a water-based coloring ink containing a resin.

  According to the ink jet recording method according to this application example, the viscosity of the colored ink can be further increased when the ink adheres to the recording medium, and bleeding or bleeding of the image can be further suppressed.

[Application Example 4] In Application Example 3,
The resin contained in the clear ink and the resin contained in the colored ink may be the same type of resin.

  According to the inkjet recording method of this application example, it is possible to form an image having more excellent fixability.

[Application Example 5] In any one of Application Examples 1 to 4,
The recording medium surface temperature between the reaction liquid deposition step and the colored ink deposition step is 38 ° C. or less, and the coloring ink deposition starts within 30 seconds after the termination of the reaction liquid deposition on the recording medium. May be.

  According to the inkjet recording method of this application example, when the colored ink adheres, the reaction liquid having a high residual ratio of the volatile component is likely to remain on the surface of the recording medium, so that it is possible to form an image having better coloration. it can.

[Application Example 6] In any one of Application Examples 1 to 5,
The reaction liquid adhering step includes a reaction liquid adhering step in which the amount of the reactant contained in the reaction liquid in the region where the reaction liquid is adhered is 0.01 mg / inch ² or more and 0.2 mg / inch ² or less. It may be.

[Application Example 7] In any one of Application Examples 1 to 6,
The clear ink adhering step may include a clear ink adhering step in which the amount of the clear ink adhering to the area where the clear ink is adhered is 0.5 mg / inch ² or more and 3 mg / inch ² or less.

[Application Example 8] In any one of Application Examples 1 to 7,
The content of the resin in the clear ink may be 2% by mass or more and 20% by mass or less.

[Application Example 9] One embodiment of an ink set according to the present invention is as follows.
It is used for the ink jet recording method according to any one of Application Examples 1 to 8.
A reaction liquid containing a reactant that causes the components of the coloring ink containing the coloring material to aggregate or thicken,
Coloring ink,
Clear ink containing resin,
Is provided.

  According to the ink set of this application example, it is possible to record an image with excellent fixability and suppressed print unevenness on a recording medium with high stability. That is, according to the ink set of this application example, an image having good fixability of the aggregate to the recording medium can be formed by the resin of the clear ink.

FIG. 1 is a diagram schematically illustrating an example of an inkjet recording apparatus used in an inkjet recording method according to the present invention.

  Hereinafter, some embodiments of the present invention will be described. The embodiment described below describes an example of the present invention. The present invention is not limited to the following embodiments at all, and includes various modifications implemented without departing from the spirit of the present invention. Note that not all of the configurations described below are essential configurations of the present invention.

1. Ink jet recording method The ink jet recording method according to the present embodiment includes a reaction liquid adhering step of adhering a reaction liquid containing a reactant for aggregating or thickening components of a coloring ink containing a colorant to a recording medium, and a reaction liquid adhering step. Thereafter, in a state where the residual ratio of the volatile component of the reaction liquid attached to the recording medium is 25% by mass or more, the coloring ink is attached to the area where the reaction liquid is attached by an inkjet method, A clear ink attaching step of attaching a clear ink containing the first resin (resin) to the attached area.

  Hereinafter, the inkjet recording method according to the present embodiment will be sequentially described in detail.

1.1. Reaction liquid attaching step The reaction liquid attaching step is a step of attaching a reaction liquid containing a reactant to a recording medium. The reaction liquid is attached to at least an area where the colored ink is attached. The reaction liquid may be attached to a part of the recording medium or may be attached to the whole. It is preferable that the reaction liquid is attached only to the region where the colored ink is attached, from the viewpoint of reducing the amount of the reaction liquid used. Further, a region to which only the reaction liquid is adhered may remain on the recording medium.

  The reactant reacts (interacts) with the coloring material contained in the coloring ink (described later) or a resin dispersant (second resin (resin)) that may be contained in the coloring ink, thereby providing a function of coagulating the coloring material. It has the effect of thickening the colored ink. That is, the reactant can coagulate or thicken the components of the colored ink, enhance color development by coagulation of the coloring material, reduce printing unevenness, and suppress bleeding or bleeding in an image by thickening. As a result, it is possible to suppress printing unevenness of a recorded image.

  As a method for attaching the reaction liquid, any method such as spin coating, spray coating, gravure roll coating, reverse roll coating, bar coating, and ink jet method can be used.

The reaction liquid adhering step preferably includes a reaction liquid adhering step in which the amount of the reactant contained in the reaction liquid adhering to the recording medium is 0.01 mg / inch ² or more and 5 mg / inch ² or less, more preferably. Reaction liquid adhesion of 0.05 mg / inch ² or more and 5 mg / inch ² or less, still more preferably 0.08 mg / inch ² or more and 3 mg / inch ² or less, still more preferably 0.1 mg / inch ² or more and 2 mg / inch ² or less. More preferably, a step is included. By including the reaction liquid adhering step at 0.01 mg / inch ² or more, the coloring material can be easily aggregated, and the second resin can be easily thickened as occasion demands. Further, it is preferable to include a reaction liquid adhering step of 5 mg / inch2 or less, since the fixability is further improved. In particular, the amount of the reactant contained in the reaction liquid adhered to the recording medium is preferably 0.2 mg / inch2 or less, and more preferably 0.1 mg / inch2 or less, from the viewpoint of more excellent fixability.
The ink jet recording method of the present embodiment includes such a reaction liquid attaching step. Similarly, in each of the following attachment steps, the expression that the attachment step includes a predetermined amount of attachment means that at least the attachment step having the attachment amount is included. In addition, the attached amount is in the attaching step, and not all the attached matter remains in the finally obtained recorded matter.

  In the ink jet recording method of the present embodiment, although the heating and drying of the reaction liquid and the like are unnecessary, a step of drying the reaction liquid after the reaction liquid adhering step and before the colored ink adhering step may be provided. In this case, drying may be performed until the residual ratio of volatile components of the reaction solution attached to the recording medium is 25% by mass or more. The step of drying the reaction solution may be performed by natural drying, or may be drying with heating. The method for heating the reaction solution is not particularly limited, but a method described below can be used. However, in the heating and drying process, the size of the apparatus used may be increased, or the energy used may be increased.

Here, the residual ratio of the volatile component of the reaction liquid refers to the residual ratio (drying ratio) of the volatile component of the reaction liquid on the recording medium immediately before the start of the attachment of the coloring ink, and is calculated by the following equation. Can be.

Volatile component residual ratio [%] = 100 − ((Af−A) / (Af−Ae)) × 100
In the above formula, Af is the total applied amount (ejection amount [mg]) of the reaction liquid to be attached to the recording medium. Ae is the residual amount [mg] of the reaction liquid on the recording medium in a state where the reaction liquid has been dried (volatilized) to a state sufficient for using the recorded matter. Further, A is the total mass [mg] of the reaction liquid on the recording medium immediately before the adhesion of the coloring ink.

  In the formula, Af can be obtained as the applied amount of the reaction liquid, for example, from the ejection data of the ink jet recording apparatus and the mass per dot. A can be determined by measuring the mass of the recording medium at the time when the application of the coloring ink is started and the mass of the recording medium before the reaction liquid application step, and taking the difference between them.

  When measuring the residual ratio of a volatile component, it is convenient to use a recording medium prepared for the measurement. For example, the measurement can be measured by an electronic balance. Further, at the time of measurement, the relationship between the drying time and the remaining amount when predetermined heating and drying is performed on a platen after applying the reaction liquid may be obtained. Further, when performing recording with an inkjet recording apparatus, by setting the time from the application of the reaction liquid to the application of the colored ink, the time obtained from the relationship between the drying time and the remaining amount determined above, It can be a predetermined remaining amount.

  When the drying step of the reaction solution involves heating, the heating method is not particularly limited, and examples thereof include a heat press method, a normal pressure steam method, a high pressure steam method, and a thermofix method. Further, as a heat source for heating, for example, an infrared ray (lamp) may be used. In the case where a step of drying the reaction solution is provided, handling when transferring the recording medium or the like can be facilitated.

  However, as described above, it is preferable that there is no heating step of heating and drying the reaction liquid after the reaction liquid attaching step. Further, the surface temperature of the recording medium from the step of applying the reaction liquid to the step of applying the colored ink is preferably 40 ° C. or lower, more preferably 38 ° C. or lower, still more preferably 35 ° C. or lower, particularly preferably 30 ° C. or lower, and particularly preferably 25 ° C. or lower. More preferred. In addition, the time from the end of the reaction liquid attachment to the start of the coloring ink attachment is preferably within 30 seconds, more preferably within 20 seconds, further preferably within 10 seconds, and particularly preferably within 5 seconds. In this case, the residual ratio of volatile components in the reaction solution is easily set in the above range, which is preferable.

  In addition, the inkjet recording method of the present embodiment may include, for example, a corona treatment, an atmospheric pressure plasma treatment, a flame treatment, an ultraviolet irradiation treatment, a solvent treatment, and the like, in addition to the reaction liquid attaching step. These processes can be performed using a known device. In the case where these treatments are performed, it is more preferable that these treatments are performed before the reaction liquid attaching step. By performing a corona treatment, for example, before the reaction liquid attaching step, the adhesion and wettability of the reaction liquid to the surface of the recording medium can be further increased, and the adhesion and abrasion resistance of the recorded image can be improved. In some cases, it can be further improved.

  The composition of the reaction solution and the reactants contained in the reaction solution will be described later.

1.2. Recording Medium In the present specification, a non-absorbing or low-absorbing recording medium refers to a recording medium having a property of absorbing no or almost no ink. Quantitatively, the non-absorptive or low-absorptive recording medium refers to "a recording medium having a water absorption amount of 10 mL / m ² or less from the start of contact to 30 msec1 / 2 in the Bristow method". The Bristow method is a widely used method for measuring the amount of liquid absorbed in a short time, and is also adopted by the Japan Pulp and Paper Technology Association (JAPAN TAPPI). For details of the test method, see "JAPAN
TAPPI Paper and Pulp Test Method 2000 Edition "Standard No. 51 "Paper and paperboard-Liquid absorbency test method-Bristow method".

  As a non-absorbable recording medium, for example, a plastic film, a plastic sheet, a plastic plate, a base material such as paper, which is not coated with an ink, and a plastic film are bonded to a substrate. And the like. Examples of the plastic used herein include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene, poly (meth) acrylic acid, and modified products, copolymers, and blends thereof.

  Examples of the low-absorbing recording medium include a recording medium having a surface provided with a coating layer for receiving ink, and, for example, as a base material of paper, art paper, coated paper, Examples include printing paper such as matte paper, and when the substrate is a plastic film, a hydrophilic polymer is coated on the surface of polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene, or the like. , Silica and titanium particles coated with a binder.

1.3. Colored ink deposition step The colored ink deposition step is a step of recording an image on the area where the reaction liquid has been deposited, using the colored ink for ink jet recording containing a coloring material after the above-described reaction liquid deposition step. The colored ink does not need to be attached to the entire area to which the reaction liquid has been attached, and the recording medium may have the reaction liquid attached thereto and may have an area to which the colored ink is not attached. Thereby, the colorant or the like contained in the colored ink reacts with the reactant, so that the colorant aggregates on the surface of the recording medium, so that the color developability of the recorded image can be improved. Furthermore, since the colored ink adheres to the surface of the recording medium on which the reaction liquid has been applied (adhered), the reaction (interaction) between the colored ink and the reactant can be performed more reliably. As a result, it is possible to suppress the occurrence of printing unevenness or the like of the recorded image. Further, when the second resin is contained in the colored ink, the viscosity can be increased by contact with the reactant, whereby the diffusion of components between ink droplets on the recording medium is suppressed, and bleeding and bleeding are reduced. can do.

  The term “print unevenness” in this specification refers to the difference in color between droplets when droplets of the same colored ink are adhered to a recording medium, or the occurrence of an image due to droplets repelled on a recording medium. This refers to a phenomenon in which color unevenness is observed in an image to be recorded due to a defective filling or the like.

  In the colored ink attaching step, an image is recorded on the recording medium by discharging droplets of the colored ink from nozzles of the inkjet recording head and attaching the droplets to the surface of the recording medium (the area where the reaction liquid is attached). The number of colors of the colored ink attached in this step is not limited, and may be a single color (single color printing) or a plurality of colors (color printing). Even when a plurality of types of colored inks are used, each of the colored inks behaves as described in this section.

In the colored ink applying step, the amount of the applied colored ink is 0.01 mg / inch ² or more and 25 mg / inch ² or less, preferably 0.1 mg / inch ² or more and 20 mg / inch ² or less, more preferably 1 mg / inch ² or more and 10 mg. / Inch ² or less, in that the image quality of the recorded matter can be further improved while the desired color can be imparted to the recorded matter and the amount of the colored ink used can be reduced. preferably, the above color ink deposition step, the upper limit is more preferably 20 mg / inch ² or less, more preferably 15 mg / inch ² or less, 10 mg / inch ² or less being more preferred. The above-mentioned amount of adhesion is in the area of the recording medium where the above-mentioned reaction liquid attaching step was performed.

After the colored ink attaching step, a step of drying the image recorded on the surface of the recording medium may be provided. In this case, drying may be performed to such an extent that stickiness is not felt when an image attached to the recording medium is touched. The image drying step may be performed by natural drying, or may be drying involving heating. The method for heating the image is not particularly limited, and the same method as that described in the method for heating the reaction solution can be used.

  The colored ink adhering step is performed when the residual ratio of the volatile component of the reaction liquid is 25% by mass or more. In addition, the residual ratio of volatile components in the reaction liquid during the colored ink deposition step is preferably 30% by mass or more, more preferably 40% by mass or more, further preferably 50% by mass or more, and still more preferably 60% by mass or more. It is particularly preferably performed in a state of 70% by mass or more. That is, when the residual ratio of the volatile component of the reaction liquid is 25% by mass or more, the droplets of the coloring ink easily come into contact with the reaction liquid from all directions, and the aggregation and thickening of the coloring material of the coloring ink are more effectively performed. It can be carried out. In addition, the upper limit of the residual ratio of the volatile component of the reaction liquid in the colored ink attaching step is not particularly limited, but is, for example, 100% by mass or less or 95% by mass or less.

  In the ink jet recording method of the present embodiment, when a non-absorbing recording medium and a low-absorbing recording medium are used, the reaction liquid easily stays on the surface of the recording medium. Further, if the drying is not performed after the reaction liquid attaching step, the residual ratio of volatile components in the reaction liquid can be easily adjusted to 25% by mass or more. Further, even if natural drying or the above-mentioned heating drying is performed after the reaction liquid is attached, a state in which the residual ratio of volatile components of the reaction liquid is 25% by mass or more can be formed depending on the degree of drying.

  The coloring ink attaching step is performed by an inkjet method. The inkjet recording apparatus that can be used in this step is not particularly limited. For example, by controlling the timing of discharging the colored ink from the nozzles and the relative position between the nozzles and the medium corresponding to a predetermined image, What is necessary is just to be able to attach ink to the position. The method of discharging ink from the nozzles is not limited, and any method may be used as long as it is an electrostatic suction method, a piezo method, a thermal jet method, or the like. As a method for changing the relative position between the nozzle and the medium, a so-called serial type or line type may be used. In addition, as a typical inkjet recording apparatus, an apparatus including an inkjet recording head, a main body, a tray, a head driving mechanism, and a carriage can be exemplified. The ink jet recording head has a plurality of nozzles, and the nozzles communicate with an attached or separate ink cartridge (ink container) to discharge ink from the cartridge. Then, for example, at least one ink cartridge may be filled with colored inks having different hues and used. In addition, the ink jet recording apparatus can discharge various inks (for example, when a reaction liquid, a clear ink, or the like is applied by an ink jet method, each ink is introduced into the recording apparatus) in addition to the colored ink. You may comprise. With such an ink jet recording apparatus, the colored ink can be easily discharged onto the recording medium and adhered (applied), and a predetermined image or pattern can be formed on the recording medium.

  The composition of the coloring ink, the second resin (resin) that can be included in the coloring ink, and the like will be described later.

1.4. Clear Ink Adhering Step The clear ink attaching step is performed after the above-described colored ink attaching step or at the same time as the colored ink attaching step, by applying the clear ink containing the first resin (resin) to the area where the reaction liquid is attached. This is the step of attaching. The clear ink does not need to be applied only to the area where the colored ink is applied, but may be applied to the entire surface of the recording medium or an area where the colored ink is not applied. In the case where the clear ink attaching step is performed at the same time as the colored ink attaching step, for example, a scan for ejecting ink from the nozzles and attaching the ink to the recording medium while changing the relative position between the head having the nozzles and the recording medium ( Passing is performed a plurality of times, so that when printing is performed on the print area facing the head, the clear ink is discharged by the same scan as the scan for ejecting the colored ink and attaching it to the print medium, and to the same print area. This is a mode in which scanning is performed so as to attach clear ink. In the case where the clear ink attaching step is performed after the colored ink attaching step, for example, when recording is performed on the recording area by performing a plurality of scans, the colored ink is ejected to complete the attachment of the colored ink to the recording area. After that, when the clear ink is ejected to attach the clear ink to the recording area or when the recording is performed on the recording area by one scan, the clear ink is ejected more than the nozzle that ejects the colored ink. This is a mode in which a nozzle for discharging is arranged on the downstream side in the scanning direction. Of these, it is preferable to perform the clear ink attaching step after the colored ink attaching step, since the effect of the present embodiment is further enhanced.

  In this step, the first resin (resin) is applied to at least the region to which the colored ink is attached. As a result, the coloring ink is coated with the clear ink, the coloring ink does not easily fall off the recording medium, and the fixability (abrasion resistance) of the image can be improved. In addition, the presence of the first resin (resin) makes it difficult for the colored ink to come into contact with moisture or the like from the outside, so that it is possible to impart wet friction resistance.

  As described above, in the inkjet recording method of the present embodiment, when the colored ink is attached, the components of the colored ink are aggregated. Such agglomeration can improve the color developability of the image, but the shape of the agglomerate tends to be granular and the contact area with the recording medium may be small. In the ink jet recording method of the present embodiment, such an aggregate is coated with a clear ink and adhered to a recording medium to give excellent abrasion resistance.

The amount of the clear ink to be applied in the present attaching step is not particularly limited. For example, the amount of the clear ink to be applied is 0.05 mg / inch ² or more, preferably 0.1 mg / inch ² or more and 5.0 mg. / Inch ² or less, more preferably 0.5 mg / inch ² or more and 3 mg / inch ² or less. Note that the above-mentioned adhesion amount is in the region where the reaction liquid adhesion step and the colored ink adhesion step have been performed.

  As a method of performing the clear ink application step, for example, various methods such as spin coating, dip coating, spray coating, gravure roll coating, reverse roll coating, bar coating, and inkjet method can be used. It can be appropriately selected in consideration of the medium size, the device configuration, and the like.

  After the clear ink attaching step, a step of drying the clear ink or the entire liquid attached to the recording medium may be provided. In this case, for example, the drying may be performed to such an extent that the recording medium does not feel sticky.

  Such drying may be performed by natural drying, but heating may be performed from the viewpoint of improving the drying speed, fusing the first resin (resin) to the recording medium, and promoting the formation of a film. The heating method is not particularly limited, and examples thereof include a heat press method, a normal pressure steam method, a high pressure steam method, and a thermofix method.

  The composition of the clear ink, the first resin (resin) included in the clear ink, and the like will be described later.

1.5. Operation and Effect According to the ink jet recording method of the present embodiment, it is possible to record an image with excellent color developability and fixability and suppressed print unevenness on a recording medium with high stability. That is, according to the inkjet recording method of the present embodiment, the colored ink is brought into contact with the reaction liquid having a residual ratio of volatile components of 25% by mass or more, so that the reaction liquid drying step can be simplified and clear. The resin of the ink (first resin) can form an image having good fixability of the aggregate to the recording medium.

2. Reaction Liquid, Clear Ink, and Colored Ink Hereinafter, the reaction liquid, the colored ink, and the clear ink used in the inkjet recording method of the present embodiment will be described in the order of the reaction liquid, the clear ink, and the colored ink.

2.1. Reaction liquid In the inkjet recording method according to the present embodiment, a reaction liquid is used in the reaction liquid attaching step. Hereinafter, components contained in the reaction solution and components that may be contained will be described.

2.1.1. Reactant The reaction solution according to the present embodiment contains a reactant. The reactant has a function of coagulating the coloring material by reacting with the coloring material contained in the coloring ink, the pigment dispersion and / or the resin that can be contained in the coloring ink. As a result, it is possible to improve the color developability of an image recorded with the colored ink. Further, the reactant can increase the viscosity (thickening) of the colored ink by reacting with a pigment dispersion and / or a resin that can be contained in the colored ink. Thereby, bleeding and bleeding of the colored ink can be reduced.

  The reactant is not particularly limited, and examples thereof include a metal salt, an organic acid, and a cationic compound. As the cationic compound, a cationic resin, a cationic surfactant, and the like can be used. The metal salt is preferably a polyvalent metal salt, but metal salts other than the polyvalent metal salt can also be used. Among these reactants, it is preferable to use at least one selected from a metal salt and an organic acid from the viewpoint of excellent reactivity with components contained in the coloring ink.

  The reactants neutralize the surface charge of the components contained in the colored ink or change the pH of the colored ink to cause the components to aggregate or precipitate, thereby causing the colored ink to aggregate or thicken. Examples of components contained in the colored ink and reacting with the reactant include a coloring material and a resin described below.

  Examples of the polyvalent metal compound among the metal salts include, but are not limited to, a titanium compound, a chromium compound, a copper compound, a cobalt compound, a strontium compound, a barium compound, an iron compound, an aluminum compound, a calcium compound, and a magnesium compound. And salts thereof (polyvalent metal salts). Among these polyvalent metal compounds, pigments can be effectively aggregated, and therefore, at least one selected from the group consisting of aluminum compounds, calcium compounds, and magnesium compounds, and salts thereof, is preferably calcium, magnesium, or the like. Is more preferable, and at least one of a calcium salt and a magnesium salt is more preferable.

  The polyvalent metal compound is preferably an ionic polyvalent metal salt. In particular, when the polyvalent metal salt is a magnesium salt or a calcium salt, the stability of the reaction solution becomes better. Further, the counter ion of the polyvalent metal may be either an inorganic acid ion or an organic acid ion.

  Specific examples of the above polyvalent metal salts include calcium carbonate such as heavy calcium carbonate and light calcium carbonate, calcium nitrate, calcium chloride, calcium sulfate, magnesium sulfate, barium sulfate, zinc carbonate, aluminum silicate, calcium silicate, magnesium silicate And the like. Among these, at least one of magnesium sulfate, calcium nitrate, and calcium chloride is preferable since sufficient solubility in water can be ensured and traces due to the reaction solution are reduced (traces are not conspicuous). Calcium is more preferred.

  Examples of metal salts other than polyvalent metal salts include monovalent metal salts such as sodium salts and potassium salts. Examples include sodium sulfate and potassium sulfate.

  As the polyvalent metal compound, in addition to the above, chalk, kaolin, calcined clay, talc, titanium oxide, zinc oxide, zinc sulfide, synthetic silica, aluminum hydroxide, alumina, sericite, white carbon, saponite, calcium Examples include inorganic pigments such as montmorillonite, sodium montmorillonite, and bentonite, and organic pigments such as acrylic plastic pigments and urea polymer substances.

  As organic acids, for example, polyacrylic acid, acetic acid, glycolic acid, malonic acid, malic acid, maleic acid, ascorbic acid, succinic acid, glutaric acid, fumaric acid, citric acid, tartaric acid, lactic acid, sulfonic acid, orthophosphoric acid, Preferable examples include 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, and salts thereof. The organic acids may be used alone or in combination of two or more.

  Suitable examples of the inorganic acid include sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, and salts thereof. The inorganic acids may be used alone or in combination of two or more.

  Examples of the cationic resin include a cationic urethane resin, a cationic olefin resin, and a cationic allylamine resin.

  Known cationic urethane resins can be appropriately selected and used. As the cationic urethane-based resin, commercially available products can be used. For example, hydrane CP-7010, CP-7020, CP-7030, CP-7040, CP-7050, CP-7060, CP-7610 (trade name) , Dainippon Ink and Chemicals, Inc.), Superflex 600, 610, 620, 630, 640, 650 (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), urethane emulsion WBR-2120C, WBR-2122C (trade name, Taisei Fine Chemical Co., Ltd.) can be used.

  The cationic olefin resin has an olefin such as ethylene or propylene in the structural skeleton, and a known olefin resin can be appropriately selected and used. Further, the cationic olefin resin may be in an emulsion state dispersed in a solvent containing water, an organic solvent or the like. Commercial products can be used as the cationic olefin resin, and examples thereof include Arrowbase CB-1200 and CD-1200 (trade name, manufactured by Unitika Ltd.).

As the cationic allylamine-based resin, known resins can be appropriately selected and used, for example, polyallylamine hydrochloride, polyallylamine amide sulfate, allylamine hydrochloride / diallylamine hydrochloride copolymer, allylamine acetate / diallylamine acetic acid Salt copolymer, allylamine acetate / diallylamine acetate copolymer, allylamine hydrochloride / dimethylallylamine hydrochloride copolymer, allylamine / dimethylallylamine copolymer, polydiallylamine hydrochloride, polymethyldiallylamine hydrochloride, polymethyldiallylamine amide sulfate, polymethyldiallylamine acetate Salt, polydiallyldimethylammonium chloride, diallylamine acetate / sulfur dioxide copolymer, diallylmethylethylammonium ethyl sulfate - sulfur dioxide copolymers, methyl diallyl amine hydrochloride-sulfur dioxide copolymers, diallyldimethylammonium chloride-sulfur dioxide copolymers, diallyldimethylammonium chloride-acrylamide copolymer and the like. As such a cationic allylamine-based resin, commercially available products can be used. For example, PAA-HCL-01, PAA-HCL-03, PAA-HCL-05,
PAA-HCL-3L, PAA-HCL-10L, PAA-H-HCL, PAA-SA, PAA-01, PAA-03, PAA-05, PAA-08, PAA-15, PAA-15C, PAA-25, PAA-H-10C, PAA-D11-HCL, PAA-D41-HCL, PAA-D19-HCL, PAS-21CL, PAS-M-1L, PAS-M-1, PAS-22SA, PAS-M-1A, PAS-H-1L, PAS-H-5L, PAS-H-10L, PAS-92, PAS-92A, PAS-J-81L, PAS-J-81 (trade name, manufactured by Nittobo Medical Company), Hymo Neo- 600, Hymolock Q-101, Q-311, Q-501, Himax SC-505, SC-505 (trade name, manufactured by Hymo Corporation) and the like. It is possible to have.

  Examples of the cationic surfactant include primary, secondary and tertiary amine salt compounds, alkylamine salts, dialkylamine salts, aliphatic amine salts, benzalkonium salts, quaternary ammonium salts, Examples include quaternary alkylammonium salts, alkylpyridinium salts, sulfonium salts, phosphonium salts, onium salts, imidazolinium salts and the like. Specifically, for example, laurylamine, cocoamine, hydrochloride such as rosinamine, acetate and the like, lauryltrimethylammonium chloride, cetyltrimethylammonium chloride, benzyltributylammonium chloride, benzalkonium chloride, dimethylethyllaurylammonium ethyl sulfate, Dimethyl ethyl octyl ammonium ethyl sulfate, trimethyl lauryl ammonium hydrochloride, cetyl pyridinium chloride, cetyl pyridinium bromide, dihydroxy ethyl lauryl amine, decyl dimethyl benzyl ammonium chloride, dodecyl dimethyl benzyl ammonium chloride, tetradecyl dimethyl ammonium chloride, hexadecyl dimethyl ammonium chloride , Octadecyl dimethyl ammonium Mukuroraido, and the like.

  The content of the reactant can be appropriately determined so as to exert the above-described effects, and is preferably, for example, 0.1% by mass or more and 40% by mass or less based on the total mass of the reaction solution. It is preferably from 2% by mass to 25% by mass.

2.1.2. Water The reaction solution according to the present embodiment may contain water. Water functions as a main medium of the reaction solution, and is a component that evaporates and scatters upon drying. The water is preferably one from which ionic impurities such as pure water or ultrapure water such as ion-exchanged water, ultrafiltration water, reverse osmosis water, and distilled water have been removed as much as possible. In addition, it is preferable to use water sterilized by irradiation with ultraviolet light or addition of hydrogen peroxide, since the generation of mold and bacteria can be prevented when the reaction solution is stored for a long period of time.

  The content of water contained in the reaction solution can be, for example, 50% by mass or more, or may be 60% by mass or more, based on the total mass of the reaction solution.

2.1.3. Organic solvent The reaction solution according to the present embodiment may contain an organic solvent. The organic solvent has a function of improving the adhesion of the reaction liquid to the low-absorbing or non-absorbing recording medium, a function as a humectant, and the like.

  The organic solvent is not particularly limited, but examples thereof include 1,2-alkanediols, polyhydric alcohols, pyrrolidone derivatives, and glycol ethers.

Examples of the 1,2-alkanediols include 1,2-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol, and the like. . 1,2-Alkanediols are excellent in the action of enhancing the wettability of the reaction solution to the recording medium and uniformly wetting. When 1,2-alkanediols are contained, the content can be 1% by mass or more and 20% by mass or less based on the total mass of the reaction solution.

  Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, trimethylolpropane, and glycerin. Can be When polyhydric alcohols are contained, the content can be 2% by mass or more and 30% by mass or less based on the total mass of the reaction solution.

  Examples of the pyrrolidone derivative include, for example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, 2-pyrrolidone, N-butyl-2-pyrrolidone, 5-methyl-2-pyrrolidone And the like.

  Examples of the glycol ethers include ethylene glycol monoisobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monoisohexyl ether, diethylene glycol monohexyl ether, triethylene glycol monohexyl ether, diethylene glycol monoisohexyl ether, and triethylene glycol monoiso. Hexyl ether, ethylene glycol monoisoheptyl ether, diethylene glycol monoisoheptyl ether, triethylene glycol monoisoheptyl ether, ethylene glycol monooctyl ether, ethylene glycol monoisooctyl ether, diethylene glycol monoisooctyl ether, triethylene glycol monoisooctyl ether , Echire Glycol mono-2-ethylhexyl ether, diethylene glycol mono-2-ethylhexyl ether, triethylene glycol mono-2-ethylhexyl ether, diethylene glycol mono-2-ethylpentyl ether, ethylene glycol mono-2-ethylpentyl ether, ethylene glycol mono-2 -Ethylhexyl ether, diethylene glycol mono-2-ethylhexyl ether, ethylene glycol mono-2-methylpentyl ether, diethylene glycol mono-2-methylpentyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, propylene glycol Monopropyl ether, dipropylene glycol mo Propyl ether, and tripropylene glycol monomethyl ether, and the like. These can be used alone or in combination of two or more. Glycol ethers can control the wettability of the reaction liquid to the recording medium.

2.1.4. Surfactant The reaction solution according to the present embodiment may contain a surfactant. The surfactant has a function of reducing surface tension and improving wettability with a recording medium. Among the surfactants, for example, acetylene glycol-based surfactants, silicone-based surfactants, and fluorine-based surfactants can be preferably used.

  The acetylene glycol-based surfactant is not particularly limited. For example, Surfynol 104, 104E, 104H, 104A, 104BC, 104DPM, 104PA, 104PG-50, 104S, 420, 440, 465, 485, SE, SE- F, 504, 61, DF37, CT111, CT121, CT131, CT136, TG, GA, DF110D (all trade names, manufactured by Air Products and Chemicals. Inc.), Olfin B, Y, P, A, STG, SPC, E1004, E1010, PD-001, PD-002W, PD-003, PD-004, EXP. 4001, EXP. 4036, EXP. 4051, AF-103, AF-104, AK-02, SK-14, AE-3 (all are trade names, manufactured by Nissin Chemical Industry Co., Ltd.), acetylenol E00, E00P, E40, E100 (all are trade names, river) Ken Fine Chemical Co., Ltd.).

  Although it does not specifically limit as a silicone type surfactant, A polysiloxane type compound is mentioned preferably. The polysiloxane-based compound is not particularly limited, and includes, for example, polyether-modified organosiloxane. Commercial products of the polyether-modified organosiloxane include, for example, BYK-306, BYK-307, BYK-333, BYK-341, BYK-345, BYK-346, and BYK-348 (all trade names, manufactured by BYK). , KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640, KF-642, KF-643, KF-6020, X-22-4515 , KF-6011, KF-6012, KF-6015, and KF-6017 (trade names, manufactured by Shin-Etsu Chemical Co., Ltd.).

  As the fluorinated surfactant, it is preferable to use a fluorine-modified polymer, and specific examples include BYK-340 (manufactured by BYK Japan KK).

  When a surfactant is contained, its content can be 0.1% by mass or more and 1.5% by mass or less based on the total mass of the reaction solution.

2.1.5. Other Components The reaction solution according to the present embodiment may contain a pH adjuster, a preservative / antifungal agent, a rust inhibitor, a chelating agent, a resin, and the like, as necessary.

2.1.6. Physical properties of the reaction liquid When the reaction liquid according to the present embodiment is applied to a recording medium by an ink jet method, the surface tension at 20 ° C is reduced from the viewpoint of a balance between image quality and reliability as an ink for ink jet recording. It is preferably from 20 mN / m to 40 mN / m, and more preferably from 25 mN / m to 35 mN / m. When the reaction liquid is applied by an inkjet method, the viscosity at 20 ° C. of the reaction liquid is preferably from 3 mPa · s to 10 mPa · s, and more preferably from 3 mPa · s to 8 mPa · s from the same viewpoint. Is more preferable.

2.2. Clear ink In the inkjet recording method according to the present embodiment, a clear ink is used in the clear ink attaching step.

  The clear ink used in the clear ink attaching step contains a first resin (resin). The first resin coats the components of the coloring ink attached to the recording medium, and makes it difficult for the coloring ink to drop off from the recording medium. This has the function of improving the fixing property (scratch resistance) of the image. In addition, the presence of the first resin makes it difficult for the colored ink to come into contact with moisture or the like from the outside, so that resistance to wet friction can be imparted. Furthermore, when a step of melting the first resin is included after the step of applying the clear ink, a film of the first resin can be formed on the surface of the recording medium, and a higher-quality recorded material can be obtained. . The clear ink is not a coloring ink used for coloring, and the content of the coloring material in the ink is 0.5% by mass or less, preferably 0.1% by mass or less, more preferably 0.05% by mass. % Or less. It may not contain a coloring material.

  Hereinafter, components contained in the clear ink and components that may be contained will be described.

2.2.1. First resin The clear ink contains a resin. In the present embodiment, the resin contained in the clear ink is also referred to as a first resin. The first resin can improve physical strength such as adhesion and abrasion resistance (fixing property) of a recorded image.

  Examples of the first resin contained in the clear ink include urethane resins, acrylic resins, fluorene resins, polyolefin resins, rosin-modified resins, terpene resins, polyester resins, polyamide resins, epoxy resins, and chloride resins. Known resins such as a vinyl-based resin are exemplified. The vinyl chloride-based resin also includes a vinyl chloride copolymer such as a vinyl chloride-vinyl acetate copolymer. These resins can be used alone or in combination of two or more.

  Among the above resins, the first resin contained in the clear ink according to the present embodiment preferably contains a urethane resin, an acrylic resin, and a polyolefin resin. When these resins are used, the effect of improving the adhesion of an image to a recording medium tends to be further improved.

  Urethane-based resin is a general term for resins having urethane bonds. In addition to the urethane bond, a polyether type urethane resin containing an ether bond in the main chain, a polyester type urethane resin containing an ester bond in the main chain, and a polycarbonate type urethane resin containing a carbonate bond in the main chain are used as the urethane resin. May be. As the urethane-based resin, commercially available products may be used. For example, Superflex 460, 460s, 840, E-4000 (trade name, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), Resamine D-1060, D-2020, D -4080, D-4200, D-6300, D-6455 (trade name, manufactured by Dainichi Seika Kogyo Co., Ltd.), Takerack WS-6021, W-512-A-6 (trade name, manufactured by Mitsui Chemicals Polyurethane Co., Ltd.) And commercially available products such as Sun Cure 2710 (trade name, manufactured by LUBRIZOL) and Permarine UA-150 (trade name, manufactured by Sanyo Chemical Industries, Ltd.).

  The acrylic resin is a generic name of a polymer obtained by polymerizing an acrylic monomer such as at least (meth) acrylic acid and (meth) acrylic acid ester, and is, for example, obtained from an acrylic monomer ( Examples thereof include (meth) acrylic resins and copolymers of acrylic monomers and other monomers (for example, vinyl monomers such as styrene). Acrylamide, acrylonitrile, and the like can also be used as the acrylic monomer. Commercially available products may be used for the resin emulsion using an acrylic resin as a raw material. , Nipol LX852, LX874 (trade name, manufactured by Zeon Corporation) and the like.

  In this specification, the acrylic resin may include a styrene acrylic resin described below. Further, in this specification, the notation “(meth) acryl” means at least one of acryl and methacryl.

  Styrene acrylic resin is a copolymer obtained from a styrene monomer and an acrylic monomer, and includes styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, and styrene-methacrylic acid-acrylate. Copolymer, styrene-α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid-acrylate copolymer, and the like. Commercially available products may be used as the styrene acrylic resin. For example, Joncryl 62J, 7100, 390, 711, 511, 7001, 632, 741, 450, 840, 74J, HRC-1645J, 734, 852, 7600 , 775, 537J, 1535, PDX-7630A, 352J, 352D, PDX-7145, 538J, 7640, 7641, 631, 790, 780, 7610 (trade names, manufactured by BASF), Movinyl 966A, 975N (trade names, Japan) Synthetic Chemical Industry Co., Ltd.), Vinyblan 2586 (Nissin Chemical Industry Co., Ltd.) and the like.

The polyolefin resin has an olefin such as ethylene, propylene, or butylene in its structural skeleton, and a known resin can be appropriately selected and used. Commercial products can be used as the olefin resin, and examples thereof include Arrowbase CB-1200 and CD-1200 (trade name, manufactured by Unitika Ltd.).

  The first resin contained in the clear ink preferably contains a resin having a glass transition temperature (Tg) of 50 ° C. or lower, more preferably contains a resin having a Tg of −80 ° C. to 50 ° C., and more preferably −80 ° C. or higher. More preferably, it contains a resin having a temperature of 40 ° C. or lower. When the resin having a Tg of 50 ° C. or less is included, the adhesion of the clear ink to the recording medium may be improved, and when the resin having a Tg of −80 ° C. or more is included, the clear ink adheres to the recording medium. It can be suppressed that the property becomes too high. When Tg is lower than room temperature (25 ° C.), the resin may have good film-forming properties (film formation). The glass transition temperature of the first resin contained in the clear ink is a monomer, a compound having two or more isocyanate groups, a compound having two or more active hydrogen groups, etc., which constitute the resin used for polymerization. Can be changed by changing at least one of the kind, constitution ratio, polymerization condition, and resin modification. The polymerization conditions include the temperature during the polymerization, the type of the medium containing the monomer, the monomer concentration in the medium, the type and amount of the polymerization initiator and the catalyst used in the polymerization, and the like. The glass transition temperature can be measured by a differential scanning calorimetry (DSC method) based on JIS K7121.

  The content (solid content conversion amount) of the first resin in the clear ink is 1% by mass or more and 30% by mass or less, preferably 1.5% by mass or more and 25% by mass or less with respect to the total mass of the clear ink. More preferably, the content is 2% by mass or more and 20% by mass or less. When the content of the first resin contained in the clear ink is within the above range, the effect of improving the image fixability (scratch resistance) tends to be further improved.

  The first resin may be in a form that is contained in the clear ink as a dispersion such as an emulsion, or that is contained in the clear ink in a dissolved state. A dispersion is more preferable in terms of water resistance and scratch resistance of the recorded matter.

2.2.2. Water The clear ink according to the present embodiment contains water. The water preferably used is the same as that described for the reaction solution, and the description thereof is omitted. The content of water can be, for example, 50% by mass or more based on the total mass of the clear ink.

2.2.3. Organic solvent The clear ink according to this embodiment may contain an organic solvent. The organic solvent has functions such as enhancing the adhesion of the second resin to the first resin and suppressing drying of the clear ink. About the specific example of the organic solvent, the same organic solvent as exemplified in the description of the reaction solution can be used, and the description thereof will be omitted. The content of the organic solvent is not particularly limited, but may be, for example, 1% by mass or more and 40% by mass or less based on the total mass of the coloring ink.

2.2.4. Surfactant The clear ink according to this embodiment may contain a surfactant. The surfactant has a function of lowering the surface tension of the clear ink and improving wettability. Among the surfactants, for example, acetylene glycol-based surfactants, silicone-based surfactants, and fluorine-based surfactants can be preferably used. As specific examples of these surfactants, the same surfactants as those exemplified in the description of the reaction solution can be used, and a description thereof will be omitted. The content of the surfactant is not particularly limited, but may be 0.1% by mass or more and 1.5% by mass or less based on the total mass of the clear ink.

2.2.5. Other Components The clear ink according to the present embodiment may contain a pH adjuster, a preservative / antifungal agent, a rust inhibitor, a chelating agent, and the like, if necessary.

2.2.6. Physical Properties of Clear Ink When the clear ink according to the present embodiment is applied to a recording medium by an ink-jet method, the surface tension at 20 ° C. is reduced from the viewpoint of a balance between image quality and reliability as an ink for ink-jet recording. It is preferably from 20 mN / m to 40 mN / m, and more preferably from 25 mN / m to 35 mN / m. When the clear ink is applied by an inkjet method, the viscosity at 20 ° C. of the clear ink is preferably from 3 mPa · s to 10 mPa · s, and more preferably from 3 mPa · s to 8 mPa · s from the same viewpoint. Is more preferable.

2.3. Colored ink In the ink jet recording method according to the present embodiment, in the colored ink attaching step, an image is formed using a colored ink for ink jet recording. Hereinafter, components contained in the colored ink used in the colored ink attaching step and components that may be contained will be described.

2.3.1. Coloring material The coloring ink according to the present embodiment contains a coloring material. As the coloring material, a pigment and an acidic dye can be preferably used from the viewpoint of excellent reactivity with the reactant contained in the above-described reaction solution.

  Among the pigments, examples of the inorganic pigment include carbon black, iron oxide, and titanium oxide. Examples of the carbon black include, but are not particularly limited to, furnace black, lamp black, acetylene black, and channel black (CI pigment black 7). As a commercially available product of carbon black, for example, 2300, 900, MCF88, No. 20B, no. 33, no. 40, no. 45, no. 52, MA7, MA8, MA100, No. 2200B (all trade names, manufactured by Mitsubishi Chemical Corporation), color black FW1, FW2, FW2V, FW18, FW200, S150, S160, S170, Pretex 35, U, V, 140U, special black 6, 5, 4A, 4, 250 (all are trade names, manufactured by Degussa AG), Conductex SC, Raven 1255, 5750, 5250, 5000, 3,500, 1255, 700 (all are trade names, manufactured by Columbia Carbon Japan Ltd.) ), Manufactured by Columbian Chemicals, Regar 400R, 330R, 660R, Mogul L, Monarch 700, 800, 880, 900, 1000, 1100, 1300, 1400, Elftex 12 (all trade names, Cabot Corpora) tion)).

  As organic pigments, for example, quinacridone pigments, quinacridone quinone pigments, dioxazine pigments, phthalocyanine pigments, anthrapyrimidine pigments, anthanthrone pigments, indanthrone pigments, flavanthrone pigments, perylene pigments, Examples include ketopyrrolopyrrole pigments, perinone pigments, quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, isoindolinone pigments, azomethine pigments, and azo pigments. Specific examples of the organic pigment include the following.

  Examples of the pigment used for the cyan ink include C.I. I. Pigment Blue 1, 2, 3, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 15:34, 16, 18, 22, 60, 65, 66, C.I. I. Bat Blue 4, 60.

Pigments used for magenta ink include C.I. I. Pigment Red 1, 2, 3, 4
5, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 40, 41, 42 , 48 (Ca), 48 (Mn), 57 (Ca), 57: 1, 88, 112, 114, 122, 123, 144, 146, 149, 150, 166, 168, 170, 171, 175, 176, 176, 177, 178, 179, 184, 185, 187, 202, 209, 219, 224, 245, 254, 264, C.I. I. Pigment Violet 19, 23, 32, 33, 36, 38, 43, 50.

  Examples of the pigment used for the yellow ink include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 16, 17, 24, 34, 35, 37, 53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 99, 108, 109, 110, 113, 114, 117, 120, 124, 128, 129, 133, 138, 139, 147, 151, 153, 154, 155, 167, 172, 180, 185, 213.

  Pigments used in inks of colors other than the above, such as green ink and orange ink, include conventionally known pigments. One type of pigment may be used alone, or two or more types may be used in combination.

  Examples of the acidic dye include azo, anthraquinone, pyrazolone, phthalocyanine, xanthene, indigoid, and triphenylmethane acid dyes. Specific examples of the acid dye include C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142, C.I. I. Acid Red 52, 80, 82, 249, 254, 289, C.I. I. Acid Blue 9, 45, 249, C.I. I. Acid Black 1, 2, 24, 94 and the like. The dyes may be used alone or in combination of two or more.

2.2.2. When a pigment is used as a colorant, it is preferable that the pigment be capable of being stably dispersed and maintained in water in order to be applied to a coloring ink. As the method, a method of dispersing with a resin dispersant such as a water-soluble resin and / or a water-dispersible resin (hereinafter, the pigment treated by this method may be referred to as a “resin-dispersed pigment”), a dispersant (Hereinafter, the pigment treated by this method is sometimes referred to as a “dispersant-dispersed pigment”), and a hydrophilic functional group is chemically and physically introduced into the surface of the pigment particles, and the above resin is dispersed. Alternatively, a method of dispersing and / or dissolving in water without a dispersant (hereinafter, a pigment treated by this method may be referred to as a “surface-treated pigment”) and the like are included.

  The colored ink according to the present embodiment can use any of the above-described resin-dispersed pigment, dispersant-dispersed pigment, and surface-treated pigment, and can be used in the form of a mixture of two or more as necessary. It is preferred to contain.

Examples of the resin dispersant used for the resin dispersion pigment include polyvinyl alcohols, polyacrylic acid, acrylic acid-acrylonitrile copolymer, vinyl acetate-acrylic ester copolymer, acrylic acid-acrylic ester copolymer, and styrene. -Acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid ester copolymer, styrene-α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid- Acrylic ester copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinylnaphthalene-acrylic acid copolymer, vinylnaphthalene-maleic acid copolymer, vinyl acetate-maleic acid ester copolymer Coalescence, vinyl acetate-crotonic acid copolymer, vinyl acetate-acryl Examples thereof include acid copolymers and the like and salts thereof. Among these, a copolymer of a monomer having a hydrophobic functional group and a monomer having a hydrophilic functional group, and a polymer composed of a monomer having both a hydrophobic functional group and a hydrophilic functional group are preferable. As the form of the copolymer, any form of a random copolymer, a block copolymer, an alternating copolymer, and a graft copolymer can be used.

  The content of the resin dispersant can be appropriately selected depending on the pigment to be dispersed, but is preferably 5 parts by mass or more and 200 parts by mass or less, more preferably 100 parts by mass of the pigment in the colored ink. It is 30 parts by mass or more and 120 parts by mass or less.

2.3.3. Water The colored ink according to the present embodiment contains water. The water preferably used is the same as that described for the reaction solution, and the description thereof is omitted. The content of water can be, for example, 50% by mass or more based on the total mass of the coloring ink.

2.3.4. Organic solvent The colored ink according to this embodiment may contain an organic solvent. The organic solvent has functions such as enhancing the adhesion of the colored ink to the low-absorbing or non-absorbing recording medium described above, and suppressing drying of the head of the inkjet recording apparatus. About the specific example of the organic solvent, the same organic solvent as exemplified in the description of the reaction solution can be used, and the description thereof will be omitted. The content of the organic solvent is not particularly limited, but may be, for example, 1% by mass or more and 40% by mass or less based on the total mass of the coloring ink.

2.3.5. Surfactant The colored ink according to the present embodiment may contain a surfactant. The surfactant has a function of reducing the surface tension of the colored ink and improving the wettability with the recording medium. Among the surfactants, for example, acetylene glycol-based surfactants, silicone-based surfactants, and fluorine-based surfactants can be preferably used. As specific examples of these surfactants, the same surfactants as those exemplified in the description of the reaction solution can be used, and a description thereof will be omitted. The content of the surfactant is not particularly limited, but can be 0.1% by mass or more and 1.5% by mass or less based on the total mass of the coloring ink.

2.3.6. Second resin The colored ink according to the present embodiment may contain a resin. In this embodiment, the resin contained in the colored ink is also referred to as a second resin. About the specific example of the second resin, the same resin as the first resin exemplified in the description of the clear ink can be used, and the description thereof will be omitted. When the second resin is contained, its content (solid content equivalent amount) is preferably 1% by mass or more and 10% by mass or less, more preferably 1% by mass or more, based on the total mass of the colored ink. 7% by mass or less. When a resin dispersant is used for the colored ink, it may be regarded as the second resin. In this case, the second resin also functions as a pigment dispersant.

  When the colored ink contains the second resin, the viscosity of the colored ink can be increased by the interaction between the second resin and the above-described reactant. As a result, the fluidity of the colored ink on the recording medium is reduced, and when bleeding or a plurality of types (different hues) of colored ink is attached, mutual diffusion of components between the colored inks is suppressed. Thus, bleed can be further suppressed.

2.3.7. Other Components The colored ink according to the present embodiment may contain a pH adjuster, a preservative / antifungal agent, a rust inhibitor, a chelating agent, and the like, if necessary.

2.3.8. Physical Properties of Colored Ink The colored ink according to this embodiment preferably has a surface tension at 20 ° C. of 20 mN / m or more and 40 mN / m from the viewpoint of a balance between image quality and reliability as ink for inkjet recording. , 25 mN / m or more and 35 mN / m or less. The surface tension was measured, for example, by using an automatic surface tensiometer CBVP-Z (trade name, manufactured by Kyowa Interface Science Co., Ltd.) and measuring the surface tension when the platinum plate was wetted with the ink in an environment of 20 ° C. It can be measured by confirming.

  In addition, from the same viewpoint, the viscosity at 20 ° C. of the colored ink according to the present embodiment is preferably 3 mPa · s or more and 10 mPa · s or less, more preferably 3 mPa · s or more and 8 mPa · s or less. The viscosity can be measured, for example, by using a viscoelasticity tester MCR-300 (trade name, manufactured by Pysica) under an environment of 20 ° C.

  When the second resin is mixed with the colored ink, the same resin as the first resin included in the clear ink may be used. When the second resin is a resin of the same type as the first resin, the affinity of the first resin and the second resin is increased, and for example, the adhesion of the first resin and the second resin to the recording medium is increased. The effect of enclosing and fixing the coloring material of the coloring ink can be enhanced. By these effects, when the second resin is a resin of the same type as the first resin, it is possible to enhance the scratch resistance and the wet friction resistance of the image. Here, the same type refers to a case where the same classification is obtained when the resins are classified as the above-described urethane-based resin, acrylic resin, fluorene-based resin, and the like.

3. Ink jet recording apparatus The ink jet recording apparatus according to the present embodiment moves relative to the recording medium, a reaction liquid containing a reactant that aggregates or thickens the components of the coloring ink containing the coloring material, the coloring ink, and A recording head for discharging clear ink containing the first resin; Then, after the reaction liquid is applied to the recording medium, the colored ink is applied to the area where the reaction liquid is applied while the residual ratio of the volatile component of the reaction liquid attached to the recording medium is 25% by mass or more. Then, the clear ink is applied to the area where the colored ink is applied.

  As an example of the ink jet recording apparatus of the present embodiment, an ink jet recording apparatus that can be used in the colored ink adhering step described in the section “1.3. Colored ink adhering step” can be mentioned. Liquid, colored ink and clear ink can be exemplified.

  Hereinafter, an example of an inkjet recording apparatus capable of performing the inkjet recording method according to the present embodiment will be briefly described with reference to the drawings. In addition, the inkjet recording apparatus that can be used in the inkjet recording method according to the present embodiment is not limited to the following aspects. That is, in the following embodiments, all the steps are performed continuously in one line (inline). However, each step may be performed intermittently instead of being performed inline.

  FIG. 1 is a diagram schematically illustrating an inkjet recording apparatus that can execute the image recording method according to the present embodiment. The inkjet recording apparatus 1000 according to the present embodiment includes a transport unit 10 that transports the recording medium 1 and a recording head that moves relatively to the recording medium 1 and adheres the reaction liquid to the recording medium 1 as the recording unit 20. 22, a recording head 24 that moves relatively to the recording medium 1 and attaches the colored ink to the recording medium 1, and a recording head 24 that moves relatively to the recording medium 1 and attaches the clear ink to the recording medium 1. A recording head 26.

3.1. Conveying Means The conveying means 10 can be constituted by, for example, a roller 11. The transport means 10 may have a plurality of rollers 11. In the illustrated example, the transport unit 10 is provided upstream of the recording unit 20 in the direction in which the recording medium 1 is transported (indicated by an arrow in the drawing), but is not limited thereto. As long as 1 can be conveyed, the position and the number of positions are arbitrary. The transport unit 10 may include a paper feed roll, a paper feed tray, a paper discharge roll, a paper discharge tray, various platens, and the like.

  The recording medium 1 conveyed by the conveying unit 10 is conveyed by the recording unit 20 to a position where each liquid is attached. Although FIG. 1 illustrates a case where the recording medium 1 is a continuous body, even if the recording medium 10 is a single sheet, the recording medium as described above can be appropriately configured by the transport unit 10. Can be transported.

3.2. Recording Unit In the inkjet recording apparatus 1000 of the present embodiment, the recording unit 20 has recording heads 22, 24, and 26. The recording head 22 deposits a reaction liquid on a predetermined area of the recording medium 1. The recording head 24 deposits colored ink on a predetermined area of the recording medium 1 to which the reaction liquid has been deposited. Further, the recording head 26 causes the clear ink to adhere onto a predetermined area of the recording medium 1 to which the colored ink has adhered. Although FIG. 1 shows a case where an ink jet method is used as the recording unit 20, the present invention is not limited to this, and may be changed to a mode in which the above-described method (for example, spray coating or roll coating) can be performed.

  Although not shown, the reaction liquid adhered to the recording medium 1 may be dried by a drying unit (not shown). Such a drying unit is preferably disposed downstream of the recording head 22 and upstream of the recording head 24 in the transport direction of the recording medium 1, but the position and number of the drying units are arbitrary. The drying means is not particularly limited as long as it has a structure for promoting the evaporation and scattering of volatile components of the liquid. For example, a means for applying heat to the recording medium 1, a means for blowing air to the liquid, and a combination thereof Means and the like. Specifically, forced air heating, radiation heating, conductive heating, high frequency drying, microwave drying, and the like are preferably used.

  When performing the drying by natural drying, the inkjet recording apparatus 1000 according to the embodiment may not include the drying unit. The means for drying the liquid adhered to the recording medium 1 may be provided at a position facing the recording heads 22, 24, 26 of the recording means 20 via the recording medium 1, or at a downstream side of each head. It may be provided, or may be provided at both of these positions.

  As the recording unit 20, any of an ink jet recording apparatus having a serial type recording head and an ink jet recording apparatus having a line type recording head can be used.

  An ink jet recording apparatus having a serial type recording head performs recording by performing a plurality of scans (passes) for discharging a liquid composition while moving the recording head relative to a recording medium. is there. In a specific example of the serial type recording head, the recording head is mounted on a carriage that moves in the width direction of the recording medium (a direction intersecting the conveying direction of the recording medium), and the recording head moves with the movement of the carriage. Then, a droplet is ejected onto a recording medium.

  On the other hand, an inkjet recording apparatus having a line-type recording head performs recording by performing a single scan (pass) of discharging a liquid composition while moving the recording head relatively to a recording medium. is there. A specific example of the line type recording head includes a recording head formed to be wider than the width of the recording medium, and ejecting liquid droplets onto the recording medium without moving the recording head.

  Since the serial print head prints an image in a plurality of passes, it is possible to secure a drying time for droplets ejected by a previous pass before the last pass is performed. On the other hand, the line type recording head attaches all the droplets necessary for recording in a single pass to the recording medium, so that compared with the case where a serial type recording head is used, the line type recording head is used. Short drying time. Therefore, a higher effect can be obtained in the ink jet recording method according to the embodiment.

  As described above, in one aspect of the present embodiment, the reaction liquid, the coloring ink, and the clear ink can have physical properties suitable for inkjet recording, and such liquids can be introduced into the ink cartridge of the inkjet recording apparatus. For example, the inkjet recording method of the present embodiment can be easily performed.

  According to such an ink jet recording apparatus, it is possible to record an image with excellent color developability and fixability and suppressed print unevenness on a recording medium with high stability. That is, according to the ink jet recording apparatus of the present embodiment, when the colored ink comes into contact with the reaction liquid containing a large amount of volatile components, aggregation of the coloring material occurs in a granular form, so that the coloring properties are good, and the clear ink By using one resin, an image having good fixability of the aggregate to the recording medium can be formed.

4. Ink set The ink set of the present embodiment includes a reaction liquid containing a reactant that coagulates or thickens the components of the coloring ink containing the coloring material, the coloring ink described above, and a clear ink containing the first resin. Including. The ink set of the present embodiment may include other liquid compositions in addition to these configurations. Further, the reaction liquid and the clear ink of the ink set of the present embodiment do not necessarily have to have physical properties that can be used in an inkjet recording apparatus. That is, the reaction liquid and the clear ink may have physical properties suitable for spin coating, spray coating, gravure roll coating, reverse roll coating, bar coating, and the like. Therefore, the ink set of the present embodiment is a set of liquids that can be used in the above-described inkjet recording method, and may be set in any package.

5. Examples Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

5.1. Preparation of Reaction Solution Each component was mixed and stirred so as to have the mixing ratio shown in Table 1, and then filtered through a 10 μm membrane filter to prepare a reaction solution. The numerical values in Table 2 all indicate mass%, and ion-exchanged water was added so that the total mass of the reaction solution became 100 mass%. Each reaction solution described in Table 1 contains magnesium sulfate (a polyvalent metal salt), maleic acid (an organic acid), or sodium sulfate (a metal salt of an inorganic acid) as a reactant.

  In Table 1, components indicated by compound names were obtained from reagents, and components indicated by other than compound names were as follows.

-BYK-348 (trade name, manufactured by BYK Japan KK, silicone surfactant)

5.2. Preparation of Colored Ink Colored inks were prepared by mixing and stirring the components so that the blending ratios were as shown in Table 2, and then filtering through a 10 μm membrane filter. In preparing the colored ink, a pigment dispersion containing a pigment, a resin dispersant, and water was prepared in advance, and the pigment dispersion and the remaining components were mixed. The numerical values in Table 2 all indicate mass%, and ion-exchanged water was added so that the total mass of the coloring ink became 100 mass%. In addition, as a pigment, C.I. I. Pigment Blue 15: 3 (cyan pigment) was used. In addition, each colored ink described in Table 2 includes the substances in the table as the second resin. Each resin is as follows. In each table, the solid component is the mass of the solid component.
・ Viniblan 2586 (trade name, water-based styrene-acrylic resin emulsion manufactured by Nissin Chemical Industry Co., Ltd.)
-D4200 (trade name: Resamine D-4200, manufactured by Dainichi Seika Kogyo Co., Ltd., aqueous urethane emulsion)

5.3. Preparation of Clear Ink A clear ink was prepared by mixing and stirring the components so that the mixing ratio was as shown in Table 3, and then filtering through a 10 μm membrane filter. The numerical values in Table 3 all indicate mass%, and ion-exchanged water was added so that the total mass of the clear ink became 100 mass%. In addition, each clear ink described in Table 3 includes the substances in the table as the second resin.

5.4. Recording Medium In the following evaluation tests, a polypropylene film (trade name “SY51M”, manufactured by UPM RAFLATA) was used as a non-absorbable recording medium.

5.5. Preparation of Recorded Items Tables 4 and 5 show preparation conditions and evaluation results of Examples and Comparative Examples. In each example, a modified machine of an inkjet printer PX-G930 (manufactured by Seiko Epson Corporation) was charged with the reaction liquid, the coloring ink, and the clear ink prepared as described above so as to have one nozzle row / one liquid. The nozzle density of the nozzle row of the recording head of the printer was 300 dpi. The recording medium was set, and the reaction solution was applied in the amounts shown in Tables 4 and 5. The pattern was a solid pattern of 10 cm × 10 cm. After the attachment, the recording medium was returned and set again, and the colored ink was superimposed on the same pattern, and applied with an attached amount of 7 mg / inch ² and printing was performed.

  Thereafter, the recording medium was returned and set again, and the clear ink was applied to the same pattern in an overlapping manner as shown in Tables 4 and 5. The dot resolution for printing was 1200 × 1200 dpi for all of the reaction liquid, colored ink and clear ink. Thereafter, the recording medium was heated and dried in an oven at 60 ° C. for 10 minutes.

  A heater was attached to the platen of the printer so that the recording medium could be heated during recording.

  Tables 4 and 5 also show whether or not the reaction liquid drying step was performed. The example without the drying step is an example in which the recording medium was set again immediately after the reaction liquid was attached without operating the heater. The surface temperature of the recording medium during recording was set at 25 ° C., and the residual ratio of volatile components in the reaction liquid during printing of the colored ink was adjusted to 90%. However, in Example 6 where the residual ratio was 50%, the mixture was allowed to stand at room temperature after adhering the reaction solution so that the concentration became 50%. The example in which the residual ratio was 90% was within 5 seconds from the end of the reaction liquid deposition to the start of the coloring ink deposition, and the example 6 in which the residual ratio was 50% was 30 seconds from the termination of the reaction liquid deposition to the beginning of the coloring ink deposition. In each case, the recording medium surface temperature during each attaching step was 25 ° C. In Example 11 in which the residual ratio was 30%, the time from the end of the reaction liquid attachment to the start of the coloring ink attachment was 25 seconds, and the recording medium surface temperature during the attachment process was 50 ° C. In Comparative Examples 1 and 4 having a residual rate of 20%, the time from the end of the reaction liquid attachment to the start of the coloring ink attachment was 25 seconds, and the recording medium surface temperature during the attachment step was 55 ° C.

  Further, in Example 10 and Comparative Example 5 having a drying step, printing was performed by operating the heater so that the surface temperature of the recording medium was 45 ° C. It took about 25 seconds from the end of the reaction liquid attachment to the start of the coloring ink attachment. After printing the reaction liquid, the residual ratio of the volatile component of the reaction liquid is described in the table.

5.6. Evaluation test 5.6.1. Fixing property (scratch resistance)
The fixing property of the image was evaluated by a rubbing test with a cloth. Abrasion resistance was evaluated using a Gakushin type friction fastness tester AB-301 (trade name, manufactured by Tester Sangyo Co., Ltd.). Specifically, the surface of the recording medium on which the image was recorded was rubbed with a friction element to which a white cotton cloth (JIS L0803) was attached under a load of 300 g until the coating film was peeled off or 30 reciprocations. Then, the degree of peeling of the image (coating film) on the surface of the recording medium was visually observed. The evaluation criteria are as follows.
☆: The coating film was not peeled even after 30 reciprocations. ◎: The coating film was peeled from 20 to 29 reciprocations. ○: The coating film was peeled from 15 to 19 reciprocations. △: 10 reciprocations. Peeling of the coating film was observed within 14 reciprocations or less. ×: Peeling of the coating film was observed within 9 reciprocations.

5.6.2. Image Quality The solid pattern recorded on the surface of the recording medium of each sample was visually checked to determine the presence or absence of printing unevenness (solid embedding property). The evaluation criteria are as follows.
◎: No unevenness of ink density was observed in the pattern. ：: Fine unevenness was observed. X: Large unevenness was observed.

5.6.3. Printing stability 1
A solid pattern was printed on 300 sheets of A4PPC paper in the same manner as in the evaluation of fixability. With respect to the nozzle row (300 nozzles), the nozzle inspection of the colored ink was performed every time 50 sheets were printed. The printing stability was evaluated according to the following evaluation criteria, and the results are shown in the table.
：: There is no nozzle that cannot be ejected X: There is a nozzle that cannot be ejected (nozzle missing), but the portion where the colored ink has not arrived due to the non-ejection of the colored ink was not conspicuous in the pattern The number of nozzles was less than 15% of the total)
XX: There were nozzles that could not be ejected (no nozzles were missing), and the portion where the colored ink was not attached due to the non-ejection of the colored ink was conspicuous in the pattern (the number of nozzles that could not be ejected was 15% or more of the whole) )
5.6.4. Printing stability 2
A solid pattern was printed on 300 sheets of A4PPC paper in the same manner as in the evaluation of fixability. For each nozzle row (300 nozzles), a clear ink nozzle test was performed every time 50 sheets were printed. The printing stability was evaluated according to the following evaluation criteria, and the results are shown in the table.
：: There is no nozzle that cannot be discharged. X: There is a nozzle that cannot be discharged (nozzle missing), but a portion with poor glossiness due to non-discharge of clear ink was not conspicuous in the pattern. Was less than 15% of the whole)
XX: There were nozzles that could not be ejected (nozzle missing), and a pattern with poor gloss due to non-ejection of clear ink was conspicuous in the pattern (the number of nozzles that could not be ejected was 15% or more of the whole)

5.7. Evaluation results The results of the above evaluation tests are shown in Tables 4 and 5.

In Examples 1 to 9, all of the fixability, image quality and print stability were good, and in Examples 10 and 11, the print stability was slightly reduced, but very good fixability and image quality were obtained. Was done. On the other hand, in Comparative Examples 1 and 4, the image quality and print stability were all insufficient. Furthermore, in Comparative Example 2 in which no clear ink was used, the fixability was poor, and in Comparative Example 3 in which no reaction liquid was used, the image quality was insufficient. Further, in Comparative Example 5, although the fixability and the printing stability were reduced, the image quality was maintained well.

  Further, at least the following has been found from the results of Tables 4 and 5.

(1) From Examples 1 and 2, the clear ink using the styrene acrylic first resin can obtain more excellent abrasion resistance. (2) From Example 3-5, the second ink of the colored ink can be obtained. When the kind of the resin and the first resin of the clear ink are the same, the fixability tends to be good. (3) From Examples 1, 4 and 5, the reactants are all effective, The metal salt is particularly good. (4) From Examples 2 and 6, drying the reaction solution improves fixability, but increases the recording time. (5) Examples 2 and 7 When the amount of the reaction liquid is small, the image quality is slightly inferior but the fixability is improved. (6) From Examples 1, 7, 8, and 9, the amount of the clear ink determines the balance between the fixability and the image quality. ) From Comparative Example 1, the fixability was improved due to the strong degree of drying of the reaction solution. As described above, the heat generated by the heater adversely affects the recording head, and the printing stability of the clear ink also becomes poor. (8) From Comparative Example 2, the fixability becomes insufficient without the clear ink. (9) From Comparative Example 3, the fixability is good but no image quality is obtained without the reaction liquid. (10) From the Comparative Example 4, when the degree of drying of the reaction liquid is strong, the fixability is improved. However, heat from the heater has an adverse effect on the recording head. (11) From Comparative Example 5, when the reaction liquid is dried, although the heater has an adverse effect on the recording head, fixability can be secured even without clear ink. (12) From Examples 10 and 11, when the reaction liquid is dried appropriately, the fixability becomes very good. (13) From Examples 10 and 11, the clear ink contains a pigment. There minute, it is difficult to clog than colored inks, and the other hand, that the discharge is defective degradation of gloss pattern is conspicuous

  In each of the above examples, a serial printer is used, but it is obvious that a line printer may be used in the present invention. In the case of a line printer, for example, a line head for attaching a reaction liquid, a line head for attaching a coloring ink, and a line head for attaching a clear ink are provided. Each may be attached (applied). In the case of a line printer, the present embodiment is particularly useful in that the recording speed is particularly high and the recording speed is not reduced.

  The present invention is not limited to the embodiment described above, and various modifications are possible. For example, the invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, a configuration with the same function, method, and result, or a configuration with the same object and effect). Further, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. Further, the invention includes a configuration having the same operation and effect as the configuration described in the embodiment or a configuration capable of achieving the same object. The invention also includes a configuration in which a known technique is added to the configuration described in the embodiment.

DESCRIPTION OF SYMBOLS 1 ... Recording medium, 10 ... Conveying means, 11 ... Roller, 20 ... Recording means, 22, 24, 26 ... Recording head, 1000 ... Ink jet recording apparatus

Claims (13)

A reaction liquid adhering step of adhering a reaction liquid containing a reactant for aggregating or thickening the components of the coloring ink containing the coloring material to the recording medium,
A drying step of drying the reaction solution attached to the recording medium,
Colored ink deposition in which the colored ink is deposited by an inkjet method on a region where the reaction liquid has been deposited in a state where the residual ratio of volatile components of the reaction liquid dried in the drying step is 30% by mass or more and 45 % by mass or less. Process and
After the colored ink attaching step, or at the same time as the colored ink attaching step, to the area where the reaction liquid is attached, including a clear ink attaching step of attaching a clear ink containing a resin,
The recording medium, a non-absorbable recording medium, Ri Do plastic,
The resin contained in the coloring ink and the clear ink is, respectively, a urethane resin, or each is an acrylic resin,
The acrylic resin is a resin obtained by polymerizing at least an acrylic monomer,
An inkjet recording method , wherein the urethane-based resin is not the acrylic resin . In claim 1,
The inkjet recording method, wherein the coloring ink is a water-based coloring ink containing a resin. In claim 1 or claim 2,
The recording medium surface temperature between the reaction liquid deposition step and the colored ink deposition step is 38 ° C. or less, and the coloring ink deposition starts within 30 seconds after the termination of the reaction liquid deposition on the recording medium. Inkjet recording method. In any one of claims 1 to 3,
Ink jetting includes a reaction liquid attaching step in which an amount of the reactant contained in the reaction liquid in a region where the reaction liquid is attached is 0.01 mg / inch2 or more and 0.2 mg / inch2 or less. Recording method. In any one of claims 1 to 4,
The ink jet recording method, wherein the clear ink applying step includes a clear ink applying step in which the amount of the clear ink applied to the area where the clear ink is applied is 0.5 mg / inch2 or more and 3 mg / inch2 or less. In any one of claims 1 to 5,
An inkjet recording method, wherein the content of the resin in the clear ink is 2% by mass or more and 20% by mass or less. In any one of claims 1 to 6,
An inkjet recording method, wherein the drying step is a drying step of heating and drying the reaction liquid. In claim 7,
An inkjet recording method, wherein the heating is performed by means for applying heat to the recording medium. In any one of claims 1 to 8,
An inkjet recording method, wherein the recording medium surface temperature in the drying step is 40 ° C. or less. In any one of claims 1 to 9,
An inkjet recording method, wherein a period from the end of the deposition of the reaction liquid in the reaction liquid deposition step to the start of the deposition of the colored ink in the colored ink deposition step is within 20 seconds. In any one of claims 1 to 10,
If the color ink and the resin contained in the clear ink, their respective Ru acrylic resin der,
The inkjet recording method, wherein the acrylic resin is a styrene acrylic resin . In any one of claims 1 to 11,
An ink jet recording method, wherein the reaction liquid attaching step is performed by an ink jet method. In any one of claims 1 to 12,
The ink jet recording method, wherein the clear ink attaching step is performed by an ink jet method.

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