JP2009248468A - Inkjet recording method and inkjet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording method and device effectively suppressing the occurrence of white streaks even if a nozzle defect occurs in an inkjet head while effectively suppressing the occurrence of an image fault due to adhesion of an ink to a discharge roller even when high speed image formation is performed. <P>SOLUTION: This invention relates to the inkjet recording method and the inkjet recording device performing image formation relative to a recording medium with the inkjet head discharging the ink. The method includes the following steps (a)-(b) of: (a) applying a treatment liquid including a fatty acid and fatty acid salt or any one of them, and having a value of surface tension larger than that of the ink to the recording medium; and (b) discharging the ink with the inkjet head to a part with the treatment liquid applied thereto on the recording medium. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ink jet recording method and an ink jet recording apparatus. In particular, even when high-speed image formation is performed, it is possible to effectively suppress the occurrence of image defects due to ink ejected onto the recording medium adhering to the discharge roller, and when nozzle defects occur in the inkjet head Even so, the present invention relates to an ink jet recording method and an ink jet recording apparatus capable of effectively suppressing the generation of white stripes.

In recent years, ink jet recording technology has advanced rapidly, and it has become possible to obtain high-definition image quality comparable to silver salt photography.
However, in the ink jet recording technique, the following problems are likely to occur when trying to improve the image forming speed.
That is, when the image forming speed is increased, the recording medium is discharged through the discharge roller before the ink penetrates the recording medium. As a result, since the ink adheres to the discharge roller, there is a problem that image defects are likely to occur.
Further, when a long inkjet head is adopted as the inkjet head in order to improve the image forming speed, the inkjet head is fixed. As a result, when a nozzle defect occurs, ink is not continuously ejected along the recording medium conveyance direction to the portion of the recording medium corresponding to the defective nozzle. There is a problem that streaks are likely to occur.

Therefore, in order to solve the problem of image defects due to ink adhering to the discharge roller, there is an ink jet recording method in which the aggregating component of the ink is strongly adhered to the recording medium side and the solvent other than the aggregating component is quickly removed. It is disclosed (for example, Patent Document 1).
That is, Patent Document 1 discloses an ink jet recording method in which both a treatment liquid capable of agglomerating ink and an ink are attached onto a recording medium having a hydrophobic polymer coated on the surface. An inkjet recording method is disclosed in which fine particles having the same composition as the hydrophobic polymer coated with the treatment liquid on the recording medium are contained.

In addition, for the problem of white streaks due to nozzle defects, bubbles are generated in the ink flow path in the ink jet recording apparatus by setting the total volume of particles to a predetermined volume per ink per unit volume. An ink jet recording method that suppresses the occurrence of nozzle defects and thus suppresses the occurrence of nozzle defects is disclosed (for example, Patent Document 2).
That is, Patent Document 2, water, a water-soluble organic in solvents and ink for ink jet recording containing a coloring material, the ink 1cm total volume of the particulate material present in the ³ 1 × 10 ^-9 ~1 × 10 ^- An inkjet recording method characterized by being between ² cm ³ is disclosed.
JP 2006-263984 A (Claims) JP-A-7-82515 (Claims)

However, in the ink jet recording method of Patent Document 1, not only must a special recording medium coated with a hydrophobic polymer be used on the surface, but also the solvent of the ink remaining on the surface of the recording medium is used as a solvent absorbing roller. It is necessary to absorb by etc. Therefore, it is difficult to say that the problem of image defects due to ink adhering to the discharge roller has been fundamentally solved.
Further, in the ink jet recording method disclosed in Patent Document 2, the degree of aggregation of fine particles in the ink changes depending on the conditions, so that it is difficult to adjust the dispersibility. As a result, clogging occurs at the tip of the nozzle due to the fine particles themselves in the ink, which may cause white streaks.
Accordingly, there is a need for an ink jet recording method and an ink jet recording image apparatus that can effectively suppress these problems even when high-speed image formation is performed.

Therefore, as a result of intensive studies, the present inventor has applied a predetermined treatment liquid to the recording medium, and then ejects the ink to the portion to which the treatment liquid is applied, so that the ink permeates the recording medium. It has been found that the efficiency can be improved effectively.
As a result, even when high-speed image formation is performed, it is possible to effectively suppress the occurrence of image defects due to the ink ejected to the recording medium adhering to the discharge roller, and there is no nozzle defect in the long inkjet head. Even when it occurs, it has been found that the generation of white stripes can be effectively suppressed.
That is, the object of the present invention is to effectively suppress the occurrence of image defects due to ink adhering to the discharge roller even when high-speed image formation is performed, and to cause nozzle defects in a long inkjet head. Even if it is a case, it is providing the inkjet recording method and inkjet recording device which can suppress generation | occurrence | production of a white stripe effectively.

According to the present invention, there is provided an ink jet recording method for forming an image on a recording medium using an ink jet head for discharging ink, the method including the following steps (a) to (b): Can be provided to solve the above-mentioned problems.
(A) A step of applying a treatment liquid containing a fatty acid and / or a fatty acid salt and having a surface tension value larger than the surface tension value of the ink to the recording medium (b) recording A step of ejecting ink to the portion of the medium to which the processing liquid has been applied using an ink jet head. That is, after applying a predetermined processing liquid to the recording medium, the portion to which the processing liquid has been applied is applied. By ejecting the ink, the wettability of the ink with respect to the recording medium can be improved.
As a result, since the ink can be efficiently penetrated into the recording medium, it is possible to effectively suppress the occurrence of image defects due to the ink ejected onto the recording medium adhering to the discharge roller.
Further, since the ink easily penetrates in the plane direction of the recording medium, it is possible to effectively suppress the occurrence of white stripes even when a nozzle defect occurs in the long inkjet head.

In carrying out the ink jet recording method of the present invention, the difference between the surface tension value of the treatment liquid and the surface tension value of the ink is preferably set to a value in the range of 1 to 8 mN / m.
By carrying out in this way, the wettability of the ink with respect to the recording medium can be further improved, while excessive bleeding can be suppressed.

In carrying out the ink jet recording method of the present invention, the surface tension of the treatment liquid is preferably set to a value in the range of 30 to 45 mN / m.
By carrying out in this way, the difference between the surface tension value of the treatment liquid and the ink surface tension value can be easily adjusted within a predetermined range.

In carrying out the ink jet recording method of the present invention, it is preferable that the content of either the fatty acid and / or the fatty acid salt with respect to the total amount of the treatment liquid is within the range of 1 to 10% by weight.
By carrying out in this way, the difference between the surface tension value of the treatment liquid and the surface tension value of the ink can be more easily adjusted within a predetermined range, and remains on the surface of the recording medium. The amount of fatty acid and the like can also be adjusted within a predetermined range more easily.

In carrying out the inkjet recording method of the present invention, at least one compound selected from oleic acid, stearic acid, lauric acid, sodium oleate, sodium stearate and sodium laurate is used as the fatty acid or fatty acid salt. Is preferred.
By carrying out in this way, the difference between the surface tension value of the treatment liquid and the surface tension value of the ink can be more easily adjusted within a predetermined range, and remains on the surface of the recording medium. The amount of fatty acid and the like can also be easily adjusted within a predetermined range.

In carrying out the inkjet recording method of the present invention, hexylene glycol is 1 to 20% by weight, 2-pyrrolidone is 1 to 20% by weight, and glycerin is 5 to 30% by weight with respect to the total amount of the treatment liquid. It is preferable to make it contain within the range.
By carrying out in this way, the difference between the value of the surface tension of the treatment liquid and the value of the surface tension of the ink can be adjusted more easily within a predetermined range, and the viscosity of the treatment liquid can be reduced. It becomes a suitable range and can apply | coat with respect to a recording medium easily.

In carrying out the ink jet recording method of the present invention, it is preferable to set the coating amount of the treatment liquid to a value within the range of 3 to 14 picoliters / pixel (600 dpi).
By carrying out in this way, the permeability of the ink to the recording medium can be adjusted to a suitable range.

In carrying out the ink jet recording method of the present invention, it is preferable to apply the treatment liquid by discharging the treatment liquid from a piezo ink jet head.
By carrying out in this way, the application amount and application location can be accurately controlled.

In carrying out the ink jet recording method of the present invention, it is preferable to apply the treatment liquid corresponding to the portion where the image is formed.
That is, it is preferable to apply the treatment liquid only to a portion where ink is to be ejected in order to form an image.
By carrying out in this way, not only the processing liquid can be saved, but also the occurrence of curling and cockling in the recording medium can be effectively suppressed.

In carrying out the ink jet recording method of the present invention, it is preferable to apply the treatment liquid to a portion other than the edge portion of the image.
In other words, it is preferable not to apply the treatment liquid to the outer peripheral portion of the image where the ink is to be ejected.
By carrying out in this way, the sharpness of the image can be maintained.

Another aspect of the present invention is an ink jet recording apparatus that forms an image on a recording medium using an ink, which includes a fatty acid and / or a fatty acid salt, and has a surface tension value of the ink. A treatment liquid application means for applying a treatment liquid having a value larger than the surface tension of the recording medium to the recording medium, and an ink jet head for discharging ink to a portion of the recording medium to which the treatment liquid has been applied. And an ink jet recording apparatus.
That is, in such an apparatus, after applying a predetermined processing liquid to the recording medium, the ink is ejected to a portion where the processing liquid is applied, thereby improving the wettability of the ink to the recording medium. be able to.
Therefore, it is possible to effectively suppress the occurrence of image defects due to the ink ejected to the recording medium adhering to the discharge roller.
Moreover, even when a nozzle defect occurs in the ink jet head, the occurrence of white stripes can be effectively suppressed.

An embodiment of the present invention is an ink jet recording method for forming an image on a recording medium using an ink jet head that discharges ink, and includes the following steps (a) to (b): Is the method.
(A) A step of applying a treatment liquid containing a fatty acid and / or a fatty acid salt and having a surface tension value larger than the surface tension value of the ink to the recording medium (b) recording Step of discharging ink using an inkjet head to a portion on which a treatment liquid is applied on a medium Hereinafter, an inkjet recording method as an embodiment of the present invention will be specifically described.
Note that an ink jet recording apparatus as another embodiment of the present invention has a close inseparable relationship with the ink jet recording method, and thus will be described simultaneously in the description of the ink jet recording method.

1. Outline The outline of the ink jet recording method of the present invention will be described with reference to FIG.
An ink jet recording apparatus 20 for carrying out the ink jet recording method of the present invention has a treatment liquid coating means 21 on the upstream side in the transport direction A of the recording medium 25 and an ink jet head 22 on the downstream side. And
Here, the treatment liquid application unit 21 is a unit for applying a predetermined treatment liquid 23 to the recording medium 25. By the treatment liquid application unit 21, the step (a) in the ink jet recording method of the present invention is performed. Is implemented.
On the other hand, the inkjet head 22 is a means for ejecting the ink 24 to a portion of the recording medium 25 on which the treatment liquid 23 is applied to form an image. Step (b) in the recording method is performed.
As described above, by performing the steps (a) and (b), the printing portion of the recording medium 25 passes through the discharge roller 26 for discharging the recording medium 25 to the outside of the inkjet recording apparatus 20. In addition, the ink 24 can efficiently penetrate into the recording medium 25.
As a result, it is possible to effectively suppress the occurrence of image defects due to the ink 24 discharged to the recording medium 25 adhering to the discharge roller 26.
Further, since the ink 24 easily penetrates in the plane direction of the recording medium 25, even when a nozzle defect occurs in the long inkjet head 22, it is possible to effectively suppress the occurrence of white stripes.

2. Step (a)
In the step (a) in the present invention, a treatment liquid containing a fatty acid and / or a fatty acid salt and having a surface tension value larger than the surface tension value of the ink is applied to a recording medium. It is a process to do.

(1) Treatment liquid (1) -1 Surface tension The treatment liquid in the present invention has a surface tension value γ _t larger than the surface tension value γ of the ink, that is, γ _t and γ are The following formula (1) is satisfied.

This is because, as described above, in the ink jet recording method of the present invention, after the treatment liquid is applied to the recording medium, the ink is ejected to the portion where the treatment liquid is applied. Therefore, by setting the surface tension value in the treatment liquid to a value larger than the surface tension value of the ink, the wettability of the ink with respect to the recording medium can be improved. This is because it can penetrate well.
That is, according to the Lucas Washburn equation shown in the following equation (2) for explaining the permeation theory, when the other conditions are constant, by reducing the value of the contact angle θ of the ink with respect to the recording medium, It can be seen that the value of the penetration distance L can be increased by increasing the value of cos θ.
That is, in the present invention, the ink for the recording medium is previously applied to the recording medium by applying a treatment liquid having a surface tension value larger than that of the ink to reduce the value of the contact angle θ of the ink to the recording medium. Improves penetration efficiency.

(In Formula (2), each character means L: penetration distance, r: paper capillary radius, γ: ink surface tension, θ: contact angle, η: ink viscosity, t: time). )

The difference between the surface tension value of the treatment liquid and the surface tension value of the ink is preferably set to a value within the range of 1 to 8 mN / m.
The reason for this is that by setting the difference between the surface tension value of the treatment liquid and the surface tension value of the ink within such a range, the wettability of the ink with respect to the recording medium can be further improved, but excessively This is because bleeding can be suppressed.
That is, when the difference between the surface tension value of the treatment liquid and the ink surface tension is less than 1 mN / m, it is difficult to sufficiently improve the wettability of the ink with respect to the recording medium. Because there is. On the other hand, when the difference between the surface tension value of the processing liquid and the surface tension value of the ink exceeds 8 mN / m, the surface tension of the processing liquid becomes excessively large and This is because the wettability is excessively lowered, and it may be difficult to sufficiently improve the wettability of the ink with respect to the recording medium.
Therefore, the difference between the surface tension value of the treatment liquid and the ink surface tension value is more preferably set to a value within a range of 1 to 7 mN / m, and a value within a range of 2 to 5 mN / m. More preferably.
In addition, the value of the surface tension in the present invention indicates the value of the surface tension when the liquid temperature is 25 ° C.

Moreover, it is preferable to make the value of the surface tension of a process liquid into the value within the range of 30-45 mN / m.
This is because the difference between the surface tension value of the treatment liquid and the surface tension value of the ink can be easily determined by setting the surface tension value of the treatment liquid to a value within the range of 30 to 45 mN / m. This is because it can be adjusted within a predetermined range.
That is, when the surface tension value of the treatment liquid is less than 30 mN / m, the difference from the surface tension value of the ink may be insufficient. On the other hand, when the surface tension value of the processing liquid exceeds 45 mN / m, the surface tension of the processing liquid becomes excessively large, and the wettability of the processing liquid with respect to the recording medium may be excessively decreased. is there.
Therefore, the surface tension value of the treatment liquid is more preferably set to a value within the range of 33 to 42 mN / m, and further preferably set to a value within the range of 35 to 40 mN / m.
In addition, about the measuring method of surface tension, it describes in an Example.

(1) -2 Composition The treatment liquid in the present invention is characterized by containing a fatty acid and a fatty acid salt, or one of them.
This is because the treatment liquid contains a fatty acid and / or a fatty acid salt, thereby improving the wettability of the ink to the portion of the recording medium to which the treatment liquid is applied in the subsequent step (b). This is because it can.
As a result, the ink can be efficiently penetrated into the recording medium.
That is, since the treatment liquid contains a fatty acid and a fatty acid salt, the difference between the surface tension value of the treatment liquid and the surface tension value of the ink can be easily adjusted to a predetermined range. is there.
On the other hand, the fixability of the ink on the recording medium has no adverse effect.

Moreover, it is preferable to use at least one compound selected from oleic acid, stearic acid, lauric acid, sodium oleate, sodium stearate and sodium laurate as the fatty acid or fatty acid salt.
This is because by using these compounds as fatty acids and fatty acid salts, the difference between the surface tension value of the treatment liquid and the surface tension value of the ink can be easily adjusted within a predetermined range. This is because the amount of fatty acid and the like remaining on the surface of the recording medium can be more easily adjusted within a predetermined range.
That is, since these fatty acids and the like are in the range of 10 to 20 carbon atoms, they do not penetrate excessively into the recording medium and easily remain on the surface of the recording medium. This is because wettability can be effectively improved. On the other hand, it has sufficient solubility in water and is suitable as a constituent material of the treatment liquid.
Other usable fatty acids include myristic acid, palmitic acid, vaccenic acid, linoleic acid, and linolenic acid.
Examples of the fatty acid salts include alkali metal salts and alkaline earth metal salts such as sodium salts, potassium salts, magnesium salts, and calcium salts of these fatty acids.

Moreover, it is preferable to make the content of the fatty acid and the fatty acid salt, or any one of them relative to the total amount of the treatment liquid into a value within the range of 1 to 10% by weight.
This is because the difference between the surface tension value of the treatment liquid and the ink surface tension value is more easily adjusted to a predetermined range by setting the content of the fatty acid and the fatty acid salt in such a range. This is because the amount of fatty acid and the like remaining on the surface of the recording medium can be more easily adjusted within a predetermined range.
That is, if the content of either fatty acid and / or fatty acid salt is less than 1% by weight, ink wettability on the recording medium may not be obtained. On the other hand, when the content of the fatty acid and / or fatty acid salt exceeds 10% by weight, it may be difficult to dissolve in the treatment liquid.
Therefore, it is more preferable to set the content of the fatty acid and the fatty acid salt, or either one of the treatment liquid to a value within the range of 2 to 6% by weight, and a value within the range of 2 to 5% by weight. More preferably.

Next, the relationship between the content of sodium oleate as a fatty acid and the like, the surface tension of the treatment liquid, and the adhesion of ink to the discharge roller will be described with reference to FIG.
That is, in FIG. 2, the horizontal axis represents the content (% by weight) of sodium oleate with respect to the total amount of the processing liquid, the left vertical axis represents the surface tension (mN / m) of the processing liquid, and the right vertical axis represents the discharge roller. Characteristic curves A and B in the case of taking the evaluation of the ink adhesion to the ink (discharge roller adhesion evaluation) (relative value) are shown.
Here, the relative value of the discharge roller adhesion evaluation is a value obtained according to the following criteria.
The details of the composition of the treatment liquid, the method of measuring the surface tension, the image forming conditions in the discharge roller adhesion evaluation, and the like are described in the examples.
3: No ink is attached to the discharge roller, and no image is printed on the non-printing portion.
2: Ink adheres to the discharge roller, but the image is not printed on the non-printing area.
1: Ink adheres to the discharge roller, and an image is printed on the non-printing portion.

First, as understood from the characteristic curve A, when the content of sodium oleate is 0% by weight, the surface tension has already taken a value of around 42 mN / m. The value is larger than 34 mN / m as an example of the surface tension. It is understood that the surface tension value of the treatment liquid gradually decreases as the content of sodium oleate increases. In the characteristic curve, the content of sodium oleate is only changed in the range of up to 3% by weight. However, if the content of sodium oleate is in the range of 10% by weight or less, It has been separately confirmed that the surface tension value can be maintained at a value larger than the ink surface tension value of 34 mN / m.
Therefore, it can be seen that setting the surface tension value of the treatment liquid to a value larger than the surface tension value of the ink can be easily realized by setting the content of sodium oleate to 0 to 10% by weight. .

On the other hand, the characteristic curve A shows that the surface tension value of the treatment liquid can be kept larger than the surface tension value of the ink when the treatment liquid does not contain sodium oleate.
However, the fatty acid containing sodium oleate is not only a function of adjusting the surface tension of the treatment liquid, but also remains on the surface of the recording medium due to its predetermined carbon skeleton as described above, and the ink on the surface of the recording medium It has a function to improve wettability effectively.
Therefore, when the treatment liquid does not contain fatty acid or the like, the surface tension of the treatment liquid itself can be increased, but since the components remaining on the surface of the recording medium are lacking, the ink wettability on the surface of the recording medium is reduced. It becomes difficult to improve.

That is, as understood from the characteristic curve B, the surface tension of the treatment liquid is sufficiently high when the content of sodium oleate as a fatty acid is less than 1.0% by weight. Regardless, the discharge roller adhesion evaluation value is less than 3. On the other hand, it can be seen that the discharge roller adhesion evaluation value can be maintained at 3 when the content of sodium oleate is 1.0% by weight or more.
In addition, when the content of sodium oleate is further increased, the surface tension value of the treatment liquid becomes smaller than the surface tension value of the ink. It has been confirmed that this is impossible (see Examples).
Therefore, considering the characteristic curves A and B comprehensively, by adding a fatty acid or the like to the processing liquid within a range in which the surface tension value of the processing liquid can be maintained at a value larger than the surface tension value of the ink. It is understood that the ink penetration efficiency with respect to the recording medium reflected in the discharge roller adhesion evaluation can be effectively improved.

In addition, the fatty acid and fatty acid salt in the treatment liquid, or any other composition, is 1 to 20% by weight of hexylene glycol, 1 to 20% by weight of 2-pyrrolidone, based on the total amount of the treatment liquid, It is preferable to contain glycerin in the range of 5 to 30% by weight.
This is because the difference between the value of the surface tension of the treatment liquid and the value of the surface tension of the ink can be more easily adjusted to a predetermined range by making the composition of the treatment liquid in this way. In other words, the viscosity of the treatment liquid is in a suitable range, and the application to the recording medium can be easily performed.
That is, by setting the content of hexylene glycol within the above-described range, the surface tension and viscosity of the treatment liquid can be controlled, and further, the permeability of the treatment liquid can be controlled.
Moreover, it is because the fixability of a pigment can be improved while being able to control the viscosity of a process liquid by making content of 2-pyrrolidone into the value within the range mentioned above.
Further, by setting the glycerin content to a value within the above-described range, not only the viscosity of the treatment liquid can be controlled, but also the moisture retention of the treatment liquid can be controlled.
Therefore, in order to more easily adjust the difference between the surface tension value of the treatment liquid and the surface tension value of the ink to a predetermined range and to make the viscosity of the treatment liquid more suitable, More preferably, hexylene glycol is contained in an amount of 1 to 10% by weight, 2-pyrrolidone in an amount of 1 to 10% by weight, and glycerin in an amount of 5 to 20% by weight based on the total amount of
Further, since the surface tension of the treatment liquid can be adjusted more easily, a surfactant can be contained.
Examples of such surfactants include, for example, special phenol type nonionic surfactants such as polycyclic phenol ethoxylate, or ethylene oxide adduct of glycerite, polyethylene glycol oleate, polyoxyalkylene tallowate, sorbitan lauryl ester, Ester-type nonionic surfactants such as sorbitan oleyl ester and polyoxyethylene sorbitan oleyl ester, or amide-type nonionic surfactants such as coconut oil fatty acid diethanolamide and polyoxyethylene coconut oil fatty acid monoethanolamide, or acetylene Glycol and its ethylene oxide adducts, or alcohol sulfate sodium salt, higher alcohol sulfate sodium salt, polyoxyethylene alkylphenyl ether Anionic surfactants such as sulfuric acid ester ammonium salt and alkylbenzene sulfonic acid sodium salt, or cationic surfactants such as mono long chain alkyl cation, di long chain alkyl cation and alkylamine oxide, or laurylamidopropylacetic acid Examples include amphoteric surfactants such as betaine and laurylaminoacetic acid betaine, and these surfactants can be used alone or in combination.
Further, the addition amount of these surfactants is preferably a value within the range of 0.1 to 5% by weight, and within the range of 0.2 to 1% by weight, with respect to the total amount of the treatment liquid. More preferably.

Note that the following materials may be used instead of the above-described constituent materials or in addition to the above-described constituent materials.
That is, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, octanediol, 1,2-hexanediol, ethylene glycol monobutyl ether, triethylene glycol monomethyl ether, diethylene glycol monomethyl ether, ethylene glycol monomethyl ether, 2-butyl 2-ethyl-1,3-propanediol, 3-methyl-1,5-pentadiol, 2-ethyl-2-methyl-1,3-propanediol, 2,4-dityl-1,5-pentanediol 2,4-pentanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-1,3-propanediol, trimethylolpropane, thiodiglycol Or the like can also be used.

Moreover, when a fatty acid is contained in the treatment liquid, it is preferable to further contain an amine compound.
This is because when the pH of the treatment liquid is excessively lowered by the fatty acid, the piezo element may be easily corroded by the adhesion of the treatment liquid when the treatment liquid is applied with a piezo ink jet head. This is because it is necessary to neutralize.
Furthermore, if an amine compound is used, not only the treatment liquid is neutralized, but also the printing density can be improved by the pigment aggregation effect on the recording medium.
Examples of amine compounds that can be suitably used include triethanolamine, triisopropanolamine, monoethanolamine, and monoisopropanolamine.
In addition, it is preferable to set it as the value within the range of 5-12 as pH of a process liquid.

  In addition to the above-described composition, the treatment liquid in the present invention may contain various additives such as a viscosity adjuster, a pH adjuster, and an antiseptic / antifungal agent as necessary.

(2) Treatment liquid application method The treatment liquid application method of the present invention is not particularly limited as long as it is a method capable of stably applying a predetermined amount of the treatment liquid to the recording medium.
For example, a method of directly applying the treatment liquid to the recording medium with a roller having a porous elastic layer, a method of spraying the treatment liquid in a mist form by spraying, and the like, Any of these may be used, and the application location may be the entire surface of the recording medium or a specific portion.
On the other hand, a particularly preferable coating method includes a method of discharging a processing liquid from a piezo ink jet head.
The reason for this is that if the method uses a piezo ink jet head, the coating amount of the treatment liquid and the coating location on the recording medium can be accurately controlled.
Further, as compared with the case where a thermal ink jet head is used, the problem that the treatment liquid is thermally denatured can be fundamentally avoided.

Moreover, it is preferable that the coating amount of the treatment liquid is set to a value within the range of 3 to 14 picoliters / pixel (600 dpi).
This is because when the coating amount of the processing liquid exceeds 14 picoliters / pixel (600 dpi), the processing liquid cannot completely penetrate the recording medium, and ink permeation may be inhibited. . On the other hand, when the coating amount of the treatment liquid is less than 3 picoliters / pixel (600 dpi), the effect of improving the wettability of the ink with respect to the recording medium may be insufficient.
Therefore, it is more preferable to set the coating amount of the treatment liquid to a value within the range of 4 to 10 picoliters / pixel (600 dpi), and further to a value within the range of 5 to 10 picoliters / pixel (600 dpi). preferable.

Further, it is preferable to apply the treatment liquid corresponding to the portion where the image is formed.
That is, it is preferable to apply the treatment liquid only to a portion where ink is to be ejected in order to form an image.
The reason for this is that not only the treatment liquid can be saved by applying in this way, but also the occurrence of curling and cockling in the recording medium can be effectively suppressed.
That is, the application of the treatment liquid can improve the wettability of the ink with respect to the recording medium by ejecting the ink to the application portion, so basically, for the portion where the image is not formed, This is because it is not necessary to apply the treatment liquid.
Conversely, by not applying unnecessary processing liquid, it is possible to suppress the occurrence of curling and cockling in the recording medium.
In this way, in order to apply the processing liquid corresponding to the portion where the image is formed, it is preferable to discharge the processing liquid from the piezo ink jet head as described above.
This is because the application method can easily control the application of the treatment liquid based on the data for controlling the ejection of the ink.

Further, it is preferable to apply the treatment liquid to a portion other than the edge portion of the image.
That is, it is preferable not to apply the treatment liquid to the outer peripheral portion of the image and the portion where ink is to be ejected.
This is because the sharpness of the image can be maintained by applying in this way.
That is, when the ink jet recording method of the present invention is carried out, the ink easily penetrates in the plane direction of the recording medium. Therefore, when the treatment liquid is applied to the edge portion of the image, the sharpness of the image is increased. This is because there is a case where the damage is lost.

3. Step (b)
Step (b) in the present invention is a step of ejecting ink to the portion of the recording medium to which the treatment liquid has been applied using an inkjet head.

(1) Ink (1) -1 Surface Tension The ink in the present invention is characterized in that the value of the surface tension is smaller than the value of the surface tension of the treatment liquid.
The reason for this is that the wettability of the ink to the recording medium is improved by setting the surface tension value in the treatment liquid to a value larger than the surface tension value of the ink, as already described in the step (a). This is because the ink can efficiently penetrate into the recording medium.
The surface tension value of the ink may be in the range of the surface tension of general water-based inks. In order to adjust the surface tension value of the ink and the surface tension value of the treatment liquid, Basically, the surface tension of the treatment liquid may be changed.
Therefore, the surface tension value of the ink is preferably set to a value within a range of 30 to 45 mN / m, which is a surface tension value of a general water-based ink, and a value within a range of 32 to 40 mN / m. More preferably.

(1) -2 Composition The composition of the ink in the present invention is not particularly limited as long as it is a water-based ink generally used in the ink jet recording method.
Examples of the water-soluble organic solvent contained in the ink of the present invention include amides such as dimethylformamide and dimethylacetamide, ketones such as acetone, ethers such as tetrahydrofuran and dioxane, and polyalkylene glycols such as polyethylene glycol and polypropylene glycol. , Ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, diethylene glycol and the like alkylene glycols containing 2 to 6 carbon atoms , Glycerin, and ethylene glycol methyl (or ethyl) ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol monomethyl (or Are ethyl) ether and other lower alkyl ethers of polyhydric alcohols, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, triethanolamine, sulfolane, dimethyl sulfoxide, and the like. .

  Examples of the dye include direct dyes, acid dyes, reactive dyes, disperse dyes, and vat dyes. The content of these dyes is determined depending on the type of liquid medium component, characteristics required for the ink, etc., but is generally 0.5 to 15% by weight, preferably 1 to 7%, based on the total weight of the ink. It is in the range of wt%.

  As the pigment, various inorganic pigments and organic pigments that can be used in general ink jet recording inks can be used. I. Pigment Yellow 93, 95, 109, 110, 120, 128, 138, 139, 151, 154, 155, 173, 180, 185, 193, C.I. I. Pigment orange 34, 36, 43, 61, 63, 71, C.I. I. Pigment red 122, 202, C.I. I. Pigment blue 15, C.I. I. Pigment violet 19, 23, 33, C.I. I. Pigment black 7 and the like.

The particle diameter of the pigment is 200 nm or less, preferably 100 to 200 nm in terms of average particle diameter from the viewpoints of ink color density, hue, ink stability, and the like.
The reason for this is that if it exceeds 200 nm, clogging at the nozzle and the nozzle supply section is likely to occur, and the discharge performance may deteriorate.
Further, if the amount of pigment used is too small, the color density of the ink is lowered, while if it is too large, printing may be difficult from the viewpoint of ink viscosity and fluidity.
Accordingly, the preferred amount of pigment used is about 1 to 25% by weight, more preferably about 5 to 20% by weight, based on the total amount of the ink composition for inkjet recording.

Moreover, as a dispersing agent used in order to disperse | distribute a pigment in a solvent, the various pigment dispersing agents soluble in a solvent can be used. For example, sorbitan fatty acid esters (sorbitan monooleate, sorbitan monolaurate, sorbitan sesquioleate, sorbitan trioleate, etc.), polyoxyethylene sorbitan fatty acid esters (polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, etc.) Nonionic activators such as polyethylene glycol fatty acid esters (polyoxyethylene monostearate, polyethylene glycol diisostearate, etc.), polyoxyethylene alkylphenyl ether, polyoxyethylene octylphenyl ether, etc.) are suitable.
Furthermore, in addition to the nonionic active agent, an active agent (dispersant) generally known as an anionic active agent or a cationic active agent can be used in the present invention.
Moreover, it is preferable to add 0.01 to 1 weight% of dispersing agents with respect to the total amount of ink.
This is because if the amount is less than 0.01% by weight, the pigment may not be sufficiently dispersed. Conversely, if it is 1% by weight or more, the ejection stability from the ink jet nozzle may deteriorate.

The ink preferably contains an antioxidant. This is because it is possible to effectively prevent the ink from being oxidized and to obtain an ink having more excellent storage stability and ejection stability.
Examples of the antioxidant include alkylphenol compounds, amine compounds such as phenylenediamine, hindered phenol compounds, hydroquinone compounds, hydroxylamine compounds, and the like. The hindered phenol compound is excellent as an antioxidant for the purpose of long-term storage, and since the oxidation product is not colored, dibutylhydroxytoluene (BHT) and butylhydroxyanisole (BHA) are preferable. Moreover, compounds having phenolic OH such as hydroquinone and gallate may be used among phenolic compounds that are used as a polymerization inhibitor and have an excellent rapid and short-term antioxidant function. They can also be used in combination as appropriate.
Moreover, although the addition amount of antioxidant changes with antioxidant to be used and use environment, it is preferable to add 0.01 to 1 weight% with respect to the total amount of ink.
The reason for this is that if it is less than 0.01% by weight, the generation of foreign matter due to oxidation cannot be sufficiently suppressed, and the ejection stability from the ink jet nozzles may deteriorate. On the other hand, even if the antioxidant is added in an amount of more than 1% by weight, no further effect of antioxidant can be expected, and conversely, the dischargeability may be deteriorated.

  In addition, it is also preferable from the viewpoint of improving the compatibility between the ink and the treatment liquid, for example, using components common to the above-described treatment liquid, such as hexylene glycol, 2-pyrrolidone, glycerin, and a surfactant. It is an aspect.

(2) Ink Ejecting Method The ink ejecting method of the present invention is performed using an ink jet head.
In addition, examples of the ink discharge method using the ink jet head include a piezo method and a thermal method. In the present invention, any method may be adopted.
On the other hand, the piezo method is more preferable from the viewpoint that the ink discharge amount can be controlled relatively easily and further, since the ink is not heated, the ink composition can be applied to a wider range of ink composition than the thermal method.

  Hereinafter, based on an Example, this invention is demonstrated in detail.

[Example 1]
1. Preparation of ink Each material having the composition shown below was charged into a batch type vertical sand mill (manufactured by IMEX Co., Ltd.), filled with zirconia beads as a medium, and subjected to a dispersion treatment while cooling with water to obtain a dispersion.
Subsequently, the obtained dispersion was centrifuged to remove coarse particles, and the number average particle size of the dispersed particles was adjusted to 50 to 150 nm to obtain a pigment dispersion.
Pigment Blue 15: 3 20% by weight
Styrene-acrylic resin 5% by weight
(John Crill 683 manufactured by Johnson Co., Ltd.)
Glycerin 10% by weight
Ion exchange water 65% by weight

Next, each material having the composition shown below was stirred with a stirrer, and the obtained stirring liquid was pressure filtered with a filter having a pore size of 5 μm to obtain an ink.
25% by weight of pigment dispersion
Surfactant 0.5% by weight
(Nissin Chemical Industry Co., Ltd., Olphine E1010)
Hexylene glycol 5% by weight
2-pyrrolidone 5% by weight
Glycerin 13% by weight
51.5% by weight of water

2. Preparation of treatment liquid In addition, each material having the composition shown below was stirred with a stirrer, and the obtained stirring liquid was pressure filtered with a filter having a pore size of 5 μm to obtain a treatment liquid.
Sodium oleate 3% by weight
Hexylene glycol 5% by weight
2-pyrrolidone 5% by weight
Glycerin 13% by weight
74% by weight of water

3. Measurement of surface tension The surface tension of the obtained ink and treatment liquid was also measured.
That is, the surface tension of the obtained ink and treatment liquid was measured in accordance with JIS K 3362 under an environment of a liquid temperature of 25 ° C. using an automatic surface tension meter (manufactured by Kyowa Interface Science Co., Ltd., CBVP-Z). It was measured. The obtained results are shown in Table 1.
4). Evaluation (1) Evaluation of discharge roller adhesion Next, ink adhesion to the discharge roller was evaluated.
That is, after filling the ink and the treatment liquid into different long inkjet heads, the excess liquid coming out from the nozzle forming surface was scraped off by different wipe blades. Next, after fixing the distance between the nozzle surface of the long inkjet head and the recording medium to be 1 mm, a solid image (30 × 30 mm) having the maximum density at a driving frequency of 20 kHz is used as the recording medium of A4. Ten continuous prints were made on PPC paper. At this time, the head driving frequency was 20 kHz, and the recording medium conveyance speed was 847 mm / sec. Next, it was confirmed whether or not ink was attached to the discharge roller after printing, and whether or not an image by the discharge roller was printed on the non-printing portion, and evaluation was performed according to the following criteria. The obtained results are shown in Table 1.
The treatment liquid was applied in correspondence with the same pixel portion of the recording medium based on the image information of the print image. That is, the treatment liquid was applied only to the portion where ink was ejected.
Further, the processing liquid was not applied to the pixels corresponding to the image edge portion.
Furthermore, the coating amount of the treatment liquid was two patterns of 14 picoliters per pixel (600 dpi) and 7 picoliters.
○: Ink does not adhere to the discharge roller, and an image is not printed in the non-printing area.
(Triangle | delta): Although ink has adhered to the discharge roller, the image is not printed in the non-printing part.
X: Ink adheres to the discharge roller, and an image is printed on the non-printing portion.

In addition, the structure of each dot formation part in a long inkjet head is shown to Fig.3 (a)-(b).
More specifically, the dot forming part 10 having a bottom area of the pressurizing chamber 2 of 0.2 mm ² , a width of 200 μm, a depth of 100 μm, a diameter of the nozzle channel 4 of 30 μm, and a radius of the opening 30 of 10 μm. Using.
Further, 166 dots per row are arranged in 4 rows, and a total of 664 dots are arranged to form a long inkjet head.
Further, the pitch of the dot forming portions 10 in the same row is 150 dpi, and each adjacent row is sequentially shifted by ¼ pitch to finally become 600 dpi.

(2) Evaluation of white streak generation Further, the occurrence of white streak was evaluated.
That is, under the same conditions as in the evaluation of the discharge roller adhesion, an image obtained by removing the print data from only one vertical pixel (near the image center) in the transport direction of the solid image (30 × 30 mm) Printed on PPC paper. Next, a question “Is there any unevenness in the image area?” Was asked to 10 subjects, and the occurrence of white streaks was evaluated from the obtained answers according to the following criteria. The obtained results are shown in Table 1.
The treatment liquid was applied in correspondence with the same pixel portion of the recording medium based on the image information of the print image. That is, the treatment liquid was applied only to the portion where ink was ejected.
Further, the processing liquid was not applied to the pixels corresponding to the image edge portion (excluding the edge portion obtained by removing the print data for one pixel).
Furthermore, the coating amount of the treatment liquid was two patterns of 14 picoliters per pixel (600 dpi) and 7 picoliters.
○: 7 or more out of 10 responded that there was no unevenness.
Δ: 3 to 6 out of 10 responded that there was no unevenness.
X: Less than 2 out of 10 responded that there was no unevenness.

[Example 2]
In Example 2, when preparing the treatment solution, except that sodium oleate was not added, 3% by weight of oleic acid and 1.5% by weight of triethanolamine were added, and the total amount was adjusted with water. Inks and treatment liquids were prepared and evaluated in the same manner as in Example 1. The obtained results are shown in Table 1.

[Example 3]
In Example 3, except that sodium oleate was not added, 3% by weight of oleic acid and 2% by weight of triisopropanolamine were added, and the total amount was adjusted with water when preparing the treatment liquid. Ink and treatment liquids were prepared and evaluated in the same manner as described above. The obtained results are shown in Table 1.

[Example 4]
In Example 4, while preparing the treatment liquid, the ink and the treatment liquid were prepared in the same manner as in Example 1, except that the amount of sodium oleate added was 2% by weight and the total amount was adjusted with water. evaluated. The obtained results are shown in Table 1.

[Example 5]
In Example 5, while preparing the treatment liquid, the ink and the treatment liquid were prepared in the same manner as in Example 1, except that the amount of sodium oleate added was 1 wt% and the total amount was adjusted with water. evaluated. The obtained results are shown in Table 1.

[Example 6]
In Example 6, except that sodium oleate was not added, 2% by weight of oleic acid and 1% by weight of triethanolamine were added, and the total amount was adjusted with water when preparing the treatment solution. Ink and treatment liquids were prepared and evaluated in the same manner as described above. The obtained results are shown in Table 1.

[Example 7]
In Example 7, when the treatment liquid was prepared, 1% by weight of oleic acid and 0.5% by weight of triethanolamine were added without adding sodium oleate, and the whole amount was adjusted with water. Inks and treatment liquids were prepared and evaluated in the same manner as in Example 1. The obtained results are shown in Table 1.

[Example 8]
In Example 8, except that sodium oleate was not added, stearic acid was added by 2% by weight and triethanolamine was added by 1% by weight, and the total amount was adjusted with water. Ink and treatment liquids were prepared and evaluated in the same manner as described above. The obtained results are shown in Table 1.

[Example 9]
In Example 9, when the treatment solution was prepared, 1% by weight of stearic acid and 0.5% by weight of triethanolamine were added without adding sodium oleate, and the whole amount was adjusted with water. Inks and treatment liquids were prepared and evaluated in the same manner as in Example 1. The obtained results are shown in Table 1.

[Example 10]
In Example 10, when the treatment liquid was prepared, the amount of sodium oleate added was 2% by weight, and 0.5% by weight of a surfactant (manufactured by Nissin Chemical Industry Co., Ltd., Olphine E1010) was added. The ink and the treatment liquid were prepared and evaluated in the same manner as in Example 1 except that the total amount was adjusted with water. The obtained results are shown in Table 1.

[Example 11]
In Example 11, when preparing the treatment liquid, the amount of sodium oleate added was 1% by weight, the surfactant was added 0.5% by weight, and the total amount was adjusted with water. Ink and treatment liquid were prepared and evaluated in the same manner as in 1. The obtained results are shown in Table 1.

[Example 12]
In Example 12, when preparing the treatment liquid, 2% by weight of oleic acid, 1% by weight of triethanolamine and 0.5% by weight of a surfactant were added without adding sodium oleate, An ink and a treatment liquid were prepared and evaluated in the same manner as in Example 1 except that the amount was adjusted with water. The obtained results are shown in Table 1.

[Example 13]
In Example 13, when preparing the treatment liquid, 1% by weight of stearic acid, 0.5% by weight of triethanolamine, and 0.5% by weight of a surfactant were added without adding sodium oleate. An ink and a treatment liquid were prepared and evaluated in the same manner as in Example 1 except that the amount was adjusted with water. The obtained results are shown in Table 1.

[Example 14]
In Example 14, the treatment liquid was prepared by adding 3% by weight of lauric acid and 1.5% by weight of triethanolamine without adding sodium oleate and adjusting the total amount with water. Inks and treatment liquids were prepared and evaluated in the same manner as in Example 1. The obtained results are shown in Table 1.

[Example 15]
In Example 15, except that sodium oleate was not added, 2% by weight of lauric acid and 1% by weight of triethanolamine were added, and the total amount was adjusted with water when preparing the treatment solution. Ink and treatment liquids were prepared and evaluated in the same manner as described above. The obtained results are shown in Table 1.

[Example 16]
In Example 16, when preparing the treatment solution, 3% by weight of lauric acid, 1.5% by weight of triethanolamine and 0.5% by weight of surfactant were added without adding sodium oleate, An ink and a treatment liquid were prepared and evaluated in the same manner as in Example 1 except that the amount was adjusted with water. The obtained results are shown in Table 1.

[Example 17]
In Example 17, when preparing the treatment liquid, without adding sodium oleate, 2% by weight of lauric acid, 1% by weight of triethanolamine and 0.5% by weight of surfactant were added, and the total amount was adjusted. An ink and a treatment liquid were prepared and evaluated in the same manner as in Example 1 except that the amount was adjusted with water. The obtained results are shown in Table 1.

[Example 18]
In Example 18, when preparing the treatment liquid, 1% by weight of lauric acid, 0.5% by weight of triethanolamine and 0.5% by weight of surfactant were added without adding sodium oleate, An ink and a treatment liquid were prepared and evaluated in the same manner as in Example 1 except that the amount was adjusted with water. The obtained results are shown in Table 1.

[Comparative Example 1]
In Comparative Example 1, the ink and ink were prepared in the same manner as in Example 1 except that when the treatment liquid was prepared, 0.5% by weight of a surfactant was added without adding sodium oleate and the total amount was adjusted with water. A treatment solution was prepared and evaluated. The obtained results are shown in Table 1.

[Comparative Example 2]
In Comparative Example 2, an ink and a treatment liquid were prepared in the same manner as in Example 1 except that 0.5% by weight of a surfactant was further added and the total amount was adjusted with water when the treatment liquid was prepared. evaluated. The obtained results are shown in Table 1.

[Comparative Example 3]
In Comparative Example 3, when preparing the treatment liquid, 3% by weight of oleic acid, 1.5% by weight of triethanolamine and 0.5% by weight of surfactant were added without adding sodium oleate, An ink and a treatment liquid were prepared and evaluated in the same manner as in Example 1 except that the amount was adjusted with water. The obtained results are shown in Table 1.

[Comparative Example 4]
In Comparative Example 4, when preparing the treatment liquid, 3% by weight of oleic acid, 2% by weight of triisopropanolamine and 0.5% by weight of surfactant were added without adding sodium oleate, An ink and a treatment liquid were prepared and evaluated in the same manner as in Example 1 except that the amount was adjusted with water. The obtained results are shown in Table 1.

[Comparative Example 5]
In Comparative Example 5, the ink and the treatment liquid were prepared and evaluated in the same manner as in Example 1 except that when the treatment liquid was prepared, the total amount was adjusted with water without adding sodium oleate. The obtained results are shown in Table 1.

[Comparative Example 6]
In Comparative Example 6, when preparing the treatment liquid, 2% by weight of stearic acid, 0.5% by weight of triethanolamine and 0.5% by weight of surfactant were added without adding sodium oleate, An ink and a treatment liquid were prepared and evaluated in the same manner as in Example 1 except that the amount was adjusted with water. The obtained results are shown in Table 1.

In the ink jet recording method and the ink jet recording apparatus according to the present invention, after a predetermined treatment liquid is applied to the recording medium, the ink is ejected to a portion to which the treatment liquid is applied, whereby the recording medium is discharged. Ink penetration efficiency can be effectively improved.
As a result, even when high-speed image formation is performed, it is possible to effectively suppress the occurrence of image defects due to the ink ejected onto the recording medium adhering to the discharge roller, and nozzle defects have occurred in the inkjet head. Even in this case, generation of white stripes can be effectively suppressed.
Therefore, the ink jet recording method and the ink jet recording apparatus according to the present invention are expected to significantly contribute to speeding up and high quality in various image forming apparatuses such as copying machines and printers.

FIG. 1 is a diagram provided for explaining the outline of the ink jet recording method of the present invention. FIG. 2 is a diagram provided for explaining the relationship between the content of sodium oleate, the surface tension of the treatment liquid, and the adhesion of ink to the discharge roller. (A) And (b) is a figure provided in order to demonstrate the dot formation part of the inkjet head used for this invention.

Explanation of symbols

1: substrate, 2: pressurizing chamber, 3: nozzle, 4: nozzle flow path, 5: throttle part, 6: common flow path, 7: common electrode, 8: laminated voltage element, 9: individual electrode, 10: dot Forming unit, 20: inkjet recording apparatus, 21: processing means, 22: inkjet head, 23: processing liquid, 24: ink, 25: recording medium, 26: discharge roller, 27: transport belt, 28: timing sensor

Claims (11)

An ink jet recording method for forming an image on a recording medium using an ink jet head for discharging ink,
An inkjet recording method comprising the following steps (a) to (b):
(A) A step of applying a treatment liquid containing a fatty acid and / or a fatty acid salt and having a surface tension value larger than the surface tension value of the ink to the recording medium (b) ) A step of ejecting ink to the portion of the recording medium coated with the treatment liquid using the inkjet head   2. The ink jet recording method according to claim 1, wherein a difference between the surface tension value of the treatment liquid and the surface tension value of the ink is set to a value within a range of 1 to 8 mN / m.   3. The ink jet recording method according to claim 1, wherein the surface tension value of the treatment liquid is set to a value within a range of 30 to 45 mN / m.   The said fatty acid and fatty acid salt with respect to the whole quantity of the said process liquid, or content of either is made into the value within the range of 1 to 10 weight%, The Claim 1 characterized by the above-mentioned. Inkjet recording method.   5. The compound according to claim 1, wherein at least one compound selected from oleic acid, stearic acid, lauric acid, sodium oleate, sodium stearate and sodium laurate is used as the fatty acid or fatty acid salt. The inkjet recording method according to one item.   The hexylene glycol is contained in an amount of 1 to 20 wt%, 2-pyrrolidone is contained in an amount of 1 to 20 wt%, and glycerin is contained in a range of 5 to 30 wt% with respect to the total amount of the treatment liquid. The inkjet recording method as described in any one of 1-5.   The inkjet recording method according to claim 1, wherein the coating amount of the treatment liquid is set to a value within a range of 3 to 14 picoliters / pixel (600 dpi).   The ink jet recording method according to claim 1, wherein the treatment liquid is applied by discharging the treatment liquid from a piezo ink jet head.   The ink jet recording method according to claim 1, wherein the treatment liquid is applied corresponding to a portion where an image is formed.   The inkjet recording method according to claim 1, wherein the treatment liquid is applied to a portion other than an edge portion of an image. An ink jet recording apparatus that forms an image on a recording medium using ink,
A treatment liquid application means for applying a treatment liquid containing a fatty acid and a fatty acid salt or any one of them and having a surface tension value larger than the surface tension value of the ink to the recording medium; An inkjet recording apparatus comprising: an inkjet head that ejects ink to a portion of the recording medium to which the treatment liquid is applied.