JP2015101022A - Image forming method and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming method, by which a difference in glossiness between a part where an image is formed and a part where no image is formed can be reduced, failure in obtaining target image qualities and increase in a cost and drying time of a post-treatment liquid due to an excessive amount of the liquid applied can be prevented, and a post-treatment can be performed immediately after forming an image.SOLUTION: The image forming method includes: a pretreatment liquid imparting step of imparting a pretreatment liquid onto a recording medium before forming an image; an image forming step of forming an image formed part by imparting an ink onto the recording medium where the pretreatment liquid is imparted; and a post-treatment liquid imparting step of imparting a post-treatment liquid onto the image formed part. By the method, a difference (A-B) in glossiness described below is less than 15°: A represents a surface glossiness at an incident angle of 60 degrees on the image formed part after the post-treatment liquid is imparted; and B represents a surface glossiness at an incident angle of 60 degrees on a non-image formed part excluding the above image formed part, after the post-treatment liquid is imparted.

Description

  The present invention relates to an image forming method and an image forming apparatus.

  The ink jet recording method has a problem that an image defect typified by character bleeding tends to occur depending on the combination of ink and recording medium, and the image quality is greatly deteriorated. Therefore, a method of obtaining a high-quality image that does not cause beading or bleeding by applying a liquid (pretreatment liquid) having a component that aggregates the colorant in the ink to the recording medium before printing. Is already known.

  In recent ink jet recording apparatuses, pigment inks having good storage stability and water resistance are used. However, the pigment ink has a problem in abrasion resistance because the pigment adheres to the surface of the recording medium and easily peels off. Further, since the pigment ink loses the smoothness of the image after recording, there is a problem that a difference in gloss occurs between the printed portion and the non-printed portion. Therefore, a so-called overcoat technique has been developed in which a liquid (post-treatment liquid) having a material capable of forming a resin film is applied to a recorded image to physically protect the image and improve gloss unevenness.

In such a situation, for example, in order to provide a printed matter with high quality and excellent image robustness regardless of the type of recording medium, an ink jet recording apparatus using the two techniques has been proposed (Patent Document). 1).
Further, a recording method has been proposed in which yellow ink is used as an overcoat and the overcoat application amount is changed depending on the hue angle of the image recording portion (see Patent Document 2). However, the object of the proposed invention is to prevent image bronzing and to improve color reproducibility. With this proposed recording method, it is difficult to ensure reduction in desired transfer stain and improvement in blocking resistance. In continuous printing, there is a problem that it is even more difficult.

  Further, in the conventional ink jet recording apparatus, the pretreatment liquid and the posttreatment liquid are only applied to the recording medium under the same conditions. The optimum application amount of the pretreatment liquid and the posttreatment liquid varies depending on the printing conditions. In addition, depending on the printing speed for forming an image, sufficient drying or leaving time may be required after the image formation, and there is a problem that post-processing such as bookbinding cannot be performed immediately after the image formation.

  Accordingly, the difference in glossiness between the image forming unit and the non-image forming unit can be reduced, and the increase in cost and drying time due to insufficient target image quality and excessive application of post-processing liquid can be prevented. It is desired to provide an image forming method capable of immediately performing post-processing later.

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention can reduce the difference in glossiness between the image forming unit and the non-image forming unit, and can prevent an increase in cost and drying time due to insufficient target image quality and excessive application of post-processing liquid. An object of the present invention is to provide an image forming method capable of performing post-processing immediately after image formation.

The image forming method of the present invention as means for solving the above problems includes a pretreatment liquid application step of applying a pretreatment liquid on a recording medium before image formation;
An image forming step of forming an image forming unit by applying ink on the recording medium to which the pretreatment liquid is applied;
A post-treatment liquid application step of applying a post-treatment liquid on the recording medium after image formation,
Glossiness of surface glossiness A at an incident angle of 60 degrees with respect to the image forming portion after application of the post-treatment liquid and surface glossiness B at an incident angle of 60 degrees with respect to non-image forming portions other than the image forming portion The difference (A−B) is less than 15 °.

  According to the present invention, the conventional problems can be solved, the object can be achieved, the difference in gloss between the image forming unit and the non-image forming unit can be reduced, and the target image quality has not been achieved. An increase in cost and drying time due to excessive application of the post-processing liquid can be prevented, and an image forming method capable of performing post-processing immediately after image formation can be provided.

FIG. 1 is a top view showing an example of an image formed product by the image forming method of the present invention. FIG. 2 is a cross-sectional view showing an example of an image formed product by the image forming method of the present invention. FIG. 3 is a schematic overall view showing an example of the image forming apparatus of the present invention. FIG. 4 is an enlarged view showing an example of a pretreatment liquid applying unit in the image forming apparatus of the present invention. FIG. 5 is a schematic view showing an example of a droplet discharge head in the image forming apparatus of the present invention. FIG. 6 is a schematic enlarged view showing an example of a droplet discharge head in the image forming apparatus of the present invention. FIG. 7 is a conceptual diagram showing an example of a printing system using the image forming method of the present invention. FIG. 8 is a configuration diagram showing an example of the image forming apparatus of the present invention. FIG. 9 is a configuration diagram showing another example of the image forming apparatus of the present invention. FIG. 10 is a configuration diagram illustrating an example of a data management unit in the image forming apparatus of the present invention. FIG. 11 is a configuration diagram illustrating an example of an image output unit in the image forming apparatus of the present invention. FIG. 12 is an explanatory cross-sectional view showing an example along the longitudinal direction of the liquid chamber of the droplet discharge head in the image forming apparatus of the present invention. FIG. 13 is an explanatory cross-sectional view showing an example of the direction of the short side of the liquid chamber of the droplet discharge head in the image forming apparatus of the present invention. FIG. 14 is a flowchart of the first embodiment. FIG. 15 is a graph showing the relationship between the pretreatment liquid application amount and the granularity of the recording medium. FIG. 16 is a graph showing the relationship between the permeability of the recording medium and the required pretreatment liquid application amount. FIG. 17 is a graph showing the relationship between the amount of pretreatment liquid applied to the recording medium and the abrasion resistance. FIG. 18 is a graph showing the relationship between the post-treatment liquid application amount of the recording medium and the abrasion resistance.

(Image forming method and image forming apparatus)
The image forming method of the present invention includes a pretreatment liquid application process, an image formation process, and a posttreatment liquid application process, and further includes other processes as necessary.
The image forming apparatus of the present invention includes a pretreatment liquid application unit, an image formation unit, and a posttreatment liquid application unit, and further includes other units as necessary.

  The image forming method of the present invention can be preferably carried out by the image forming apparatus of the present invention, the pretreatment liquid application step can be performed by the pretreatment liquid application means, and the image formation step is performed by the image formation. The post-treatment liquid application step can be performed by the post-treatment liquid application unit, and the other steps can be performed by the other means.

In the present invention, the surface glossiness A at an incident angle of 60 degrees with respect to the image forming portion after application of the post-treatment liquid, and incidence on non-image forming portions other than the image forming portion after application of the post-treatment liquid. The difference in glossiness (A−B) from the surface glossiness B at an angle of 60 degrees is less than 15 °, preferably less than 10 °, and particularly preferably less than 5 °.
When the difference (A−B) is less than 15 °, it is possible to form an image having no sense of incongruity or discomfort without partial glare of the image due to the difference in gloss.
Surface glossiness A at an incident angle of 60 degrees with respect to the image forming portion after application of the post-treatment liquid, and an incident angle of 60 degrees with respect to non-image forming portions other than the image forming portion after application of the post-treatment liquid. The surface glossiness B is, for example, 60 of an image forming unit and a non-image forming unit (background portion of recording medium) using a gloss meter (BYK Gardener, 4501) according to JIS K7105-1981. Glossiness (glossiness at an incident angle of 60 degrees) can be measured, and the difference in glossiness between the image forming unit and the non-image forming unit can be obtained.
In the present invention, the difference in gloss between the image forming unit and the non-image forming unit can be reduced in this way, so that the target image quality is not achieved and the post-treatment liquid is excessively applied, thereby increasing the cost and drying time. Can be prevented. Also, post-processing can be performed immediately after image formation, so the time required for bookbinding operations such as cutting, folding, signature collation, binding, cover winding, three-side cutting after printing, and temporary storage of paper after printing And securing the location becomes unnecessary.

  Examples of the method of setting the difference in glossiness (A−B) to less than 15 ° include, for example, surface glossiness A ′ at an incident angle of 60 degrees with respect to the image forming unit before the post-treatment liquid is applied, and other than the image forming unit. And a method of appropriately adjusting the amount of the post-treatment liquid applied by an inkjet method based on the difference in glossiness (A′−B ′) from the surface glossiness B ′ at an incident angle of 60 degrees with respect to the non-image forming portion. It is done. For example, when the gloss difference (A′−B ′) is large, the application amount of the post-treatment liquid is increased. On the other hand, when the gloss difference (A′−B ′) is absent or slight, The gloss difference (A−B) can be controlled to be less than 15 ° by making adjustments such as reducing the application amount of the post-treatment liquid.

The applied amount of the post-treatment liquid is preferably 5% by volume to 30% by volume of the applied amount of ink, and more preferably 5% by volume to 15% by volume. Blocking resistance improves by making the application amount of the post-treatment liquid 5% by volume or more of the ink application amount. On the other hand, by setting the applied amount of the post-treatment liquid to 30% by volume or less of the applied amount of ink, a good image quality can be obtained in which the drying property is good and the transfer stain of the recorded image does not occur.
As a method for applying the post-treatment liquid, application by ink jet recording is preferable, and the application amount control of the post-treatment liquid can be performed by changing the number of droplets ejected from the nozzle or by controlling the drop weight per droplet ejected from the nozzle. It can be controlled by changing.

Here, in the thermal ink jet, it is difficult to change the size of the generated vapor bubbles, that is, the ejected ink droplets according to the driving waveform and the energy applied to the heating element. To eject ink droplets of different sizes, 1 It is necessary to install and select a plurality of heating elements in one flow path to change the size of the vapor bubbles, or to arrange nozzles / flow paths of different sizes in the recording head.
On the other hand, the piezo-type ink jet can control the position of the meniscus by the driving waveform, greatly vary the size of the ejected ink droplets, and uses the high responsiveness of the piezo element to continuously inject ink droplets at a high frequency. Piezo ink jets are preferred because the ink droplets are ejected and ink droplets are combined during flight or overlapped on the recording medium so that the dot diameter on the recording medium can be made different.

  If the amount of pretreatment liquid applied is increased, the target image quality and rub resistance due to insufficient application amount of processing liquid (pretreatment liquid and posttreatment liquid) are increased by increasing the amount of posttreatment liquid applied accordingly. Will not be achieved.

  When the application amount of the pretreatment liquid is reduced, the consumption amount of the posttreatment liquid can be reduced and the cost can be reduced by reducing the application amount of the posttreatment liquid accordingly.

The application area of the post-treatment liquid is preferably smaller than the application area of the ink. By making the adhesion area of the post-treatment liquid smaller than the ink application area (the area where the image is formed), the consumption of the post-treatment liquid can be reduced and the cost can be reduced.
The post-treatment liquid application area and the ink application area can be measured by, for example, measuring the penetrability of the post-treatment liquid or ink with respect to each sheet in advance and estimating the application area based on the ejection amount from the inkjet head. It can obtain | require by the method etc. which measure directly with a scanning electron microscope (SEM), a laser microscope, an optical microscope, etc.

<Pretreatment liquid application step and pretreatment liquid application means>
The pretreatment liquid application step is a step of applying a pretreatment liquid onto a recording medium before image formation, and is performed by a pretreatment liquid application unit.

  The purpose of the preprocessing is to improve image quality. Pretreatment increases the image density because the pigments aggregate on the surface of the recording medium.

<< Pretreatment liquid >>
The pretreatment liquid contains a component that aggregates water-dispersible colorant particles, a water-soluble organic solvent, a penetrating agent, a surfactant, and water, and further contains other components as necessary.

-Components that aggregate water-dispersible colorant particles-
A water-soluble aliphatic organic acid is contained as a component for aggregating the water-dispersible colorant particles.
Here, agglomeration means that water-dispersible colorant particles adsorb and gather together, and can be confirmed by a particle size distribution measuring device. When an ionic substance such as a water-soluble aliphatic organic acid is added to the pretreatment liquid, the surface charge is neutralized by adsorption of ions to the surface charge of the water-dispersible colorant. Aggregation is enhanced and aggregation is possible.
Examples of the method for confirming the aggregation include a method for confirming whether the colorant is instantaneously aggregated when 30 μL of the pretreatment liquid is added with 5 μL of the inkjet ink having a water-dispersible colorant concentration of 5 mass%. .

-Water-soluble organic solvent-
The water-soluble organic solvent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, 1,3-butane Diol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, glycerin, 1,2,6- Polyhydric alcohols such as hexanetriol, 2-ethyl-1,3-hexanediol, 1,2,4-butanetriol, 1,2,3-butanetriol, petriol; ethylene glycol monoethyl ether, ethylene glycol Monobutyl ether, diethylene glycol mono Polyhydric alcohol alkyl ethers such as chill ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether; ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, etc. Polyhydric alcohol aryl ethers; nitrogen-containing heterocyclic compounds such as N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethylimidazolidinone, ε-caprolactam; Amides such as formamide, N-methylformamide, N, N-dimethylformamide; monoethanolamine, diethanolamine, triethanol Examples include amines such as amine, monoethylamine, diethylamine, and triethylamine; sulfur-containing compounds such as dimethyl sulfoxide, sulfolane, and thiodiethanol; propylene carbonate, ethylene carbonate, and γ-butyrolactone. These may be used individually by 1 type and may use 2 or more types together.

5 mass%-80 mass% are preferable with respect to the said pretreatment liquid whole quantity, and, as for content of the said water-soluble organic solvent, 10 mass%-20 mass% are more preferable.
When the content is less than 80% by mass, the drying property of the recording medium provided with the pretreatment liquid may be lowered depending on the type of the water-soluble organic solvent, and the flocculant in the pretreatment liquid may be reduced. There is a possibility that the addition amount becomes small and the coagulation ability of the pretreatment liquid is greatly reduced. On the other hand, when the content is less than 5% by mass, the water contained in the pretreatment liquid is easily vaporized, and when the water is vaporized, the viscosity of the pretreatment liquid increases, resulting in problems in the pretreatment liquid application process. There is a possibility that.

-Penetration agent-
The penetrant is not particularly limited and may be appropriately selected depending on the intended purpose.For example, diethylene glycol monophenyl ether, ethylene glycol monophenyl ether, ethylene glycol monoallyl ether, diethylene glycol monophenyl ether, diethylene glycol monobutyl ether, Examples include alkyl and aryl ethers of polyhydric alcohols such as propylene glycol monobutyl ether and tetraethylene glycol chlorophenyl ether; lower alcohols such as ethanol and 2-propanol. These may be used individually by 1 type and may use 2 or more types together.
The content of the penetrant is preferably 0.1% by mass to 20% by mass, and more preferably 0.5% by mass to 10% by mass with respect to the total amount of the pretreatment liquid.

-Surfactant-
Examples of the surfactant include an anionic surfactant, a nonionic surfactant, a cationic surfactant, an amphoteric surfactant, a fluorine surfactant, and a silicone surfactant.
The content of the surfactant is preferably 0.01% by mass to 3.0% by mass and more preferably 0.5% by mass to 2% by mass with respect to the total amount of the pretreatment liquid.
When the content is less than 0.01% by mass, the effect of adding the surfactant may not be obtained. When the content exceeds 3.0% by mass, the permeability to the recording medium is more than necessary. In some cases, the image density may be lowered, and the back-through may occur.

-Other ingredients-
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, antiseptic / antifungal agent, a rust preventive agent, a pH adjuster etc. are mentioned.
Examples of the antiseptic / antifungal agent include sodium dehydroacetate, sodium sorbate, 2-pyridinethiol-1-oxide sodium, isothiazoline-based compounds, sodium benzoate, and sodium pentachlorophenol.
The content of the antiseptic / antifungal agent is preferably 0.01% by mass to 3.0% by mass, and more preferably 0.5% by mass to 2% by mass with respect to the total amount of the pretreatment liquid.

Examples of the rust preventive include benzotriazole, acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, dicyclohexylammonium nitrite and the like.
0.01 mass%-3.0 mass% are preferable with respect to the said pretreatment liquid whole quantity, and, as for content of the said rust preventive agent, 0.5 mass%-2 mass% are more preferable.

Examples of the pH adjusting agent include hydroxides of alkali metal elements such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, ammonium hydroxide, quaternary ammonium hydroxide, quaternary phosphonium hydroxide, Examples thereof include alkali metal carbonates such as lithium carbonate, sodium carbonate and potassium carbonate, amines such as diethanolamine and triethanolamine, boric acid, hydrochloric acid, nitric acid, sulfuric acid and acetic acid.
0.01 mass%-3.0 mass% are preferable with respect to the said pretreatment liquid whole quantity, and, as for content of the said pH adjuster, 0.5 mass%-2 mass% are more preferable.

There is no restriction | limiting in particular as a provision method of a pre-processing liquid, Although it can select suitably according to the objective, The method of apply | coating a roller to the whole recording medium is preferable.
By applying the roller, it is possible to uniformly apply a small amount of a high-concentration and high-viscosity pretreatment liquid over the entire surface of the recording medium. Also, the amount of application can be easily controlled.

<< Recording media >>
The recording medium has a coating layer that gives the printed material a texture and a high-class feeling, and can be appropriately selected according to the purpose. For example, coated paper, gloss paper, coated paper, art paper A general-purpose printing paper called super art paper is preferable.

Among these, liquid absorption characteristics are within a certain range because images with excellent image quality (image density, saturation, beading, color bleed), high gloss, and excellent smear fixability can be recorded. is suitable general printing paper is, specifically, the transfer amount of the recording medium of pure water at the contacting time 100ms measured by a dynamic scanning absorptometer is 1mL / m ² ~10mL / m ² printing Paper is used.
If the transfer amount of pure water at a contact time of 100 ms is too small, beading (density unevenness) and color bleed (bleed between colors) may occur easily. If too much, the ink dot diameter after recording will increase. In some cases, the solid image becomes smaller than the desired diameter and the solid image is not finished.

  Here, the dynamic scanning absorptiometer (DSA, Kojipa Gakkai, Vol. 48, May 1994, pp. 88-92, Kuju Shigenori) has a very short time. It is a device that can measure accurately. The dynamic scanning absorption meter (i) directly reads the liquid absorption speed from the movement of the meniscus in the capillary. (Ii) The sample is formed into a disk shape on which the liquid absorption head is scanned in a spiral shape. The measurement is automated by a method in which the scanning speed is automatically changed according to the set pattern and the measurement is performed for the number of necessary points with one sample. A liquid supply head for a paper sample is connected to a capillary via a Teflon (registered trademark) tube, and the position of the meniscus in the capillary is automatically read by an optical sensor. Specifically, the transfer amount of pure water was measured using a dynamic scanning absorption meter (K350 series D type, manufactured by Kyowa Seiko Co., Ltd.). The transfer amount at the contact time of 100 ms can be obtained by interpolation from the measured value of the transfer amount at the contact time adjacent to the contact time.

  Commercially available products can be used as the printing paper having the liquid absorption characteristics within a certain range. Examples of the commercially available products include Ricoh Business Cogross 100 (manufactured by Ricoh Co., Ltd.), OK Topcoat +, OK Kanto + , SA Kinto + (Oji Paper Co., Ltd.), Super MIdal, Aurora Coat, Space DX (Nippon Paper Industries Co., Ltd.), α Matte, Mu Coat (Hokuetsu Paper Co., Ltd.), Thunderbird Art, Thunderbird Superart (Chuetsu) Pulp Industry Co., Ltd.), Pearl Coat N (Mitsubishi Paper Co., Ltd.) and the like.

<Image forming step and image forming means>
The image forming step is a step of forming an image forming unit by applying ink onto the recording medium to which the pretreatment liquid has been applied, and is performed by an image forming unit.

<< Ink >>
The ink contains a colorant, water, a water-soluble organic solvent, and a surfactant, and further contains other components as necessary.

-Colorant-
As the colorant, a pigment, a self-dispersing pigment, or a resin-coated pigment can be used.
The pigment may be either an organic pigment or an inorganic pigment.

Examples of the organic pigment include azo, phthalocyanine, anthraquinone, quinacridone, dioxazine, indigo, thioindigo, perylene, isoindolenone, aniline black, azomethine, rhodamine B lake pigment, carbon black Etc.
Examples of the inorganic pigment include iron oxide, titanium oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, bitumen, cadmium red, chrome yellow, and metal powder.
Examples of black pigments include No. 2300, no. 900, MCF88, No. 40, no. 52, MA7, MA8, no. 2200B (Mitsubishi Kasei Co., Ltd.), RAVEN 1255 (Columbia Co., Ltd.), REGAL400R, REGAL660R, MOGUL L (Made by Botbot), Color Black FW1, Color Black FW18, Color BlackS170, Color BlackPrP 150, Color BlackPrP150 U (above, manufactured by Degussa) and the like.

  The content of the colorant is preferably 2% by mass to 12% by mass and more preferably 4% by mass to 8% by mass with respect to the total amount of the ink. When the content is less than 2% by mass, the image density may be lowered due to a decrease in coloring power, or feathering or bleeding may be deteriorated due to a decrease in viscosity. When the content exceeds 12% by mass, inkjet recording may be performed. If the device is left unattended, the ink in the nozzles will tend to thicken, causing non-ejection phenomena, penetrability decreases due to excessively high viscosity, and dots do not spread. The density may decrease or the image may become blurred.

There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, antiseptic / antifungal agent, a rust preventive agent, a pH adjuster etc. are mentioned.
As the water-soluble organic solvent, the surfactant, the antiseptic / antifungal agent, the rust-preventing agent, and the pH adjuster in the ink, those similar to the pretreatment liquid can be used.

In the image formation, a stimulus (energy) is applied to the ink, and the image is formed on the recording medium by causing the ink to fly on the surface having the coating layer of the recording medium. The inkjet recording method can be applied, and examples thereof include an inkjet recording method in which a head is scanned, and an inkjet recording method in which an image is formed on a recording medium using a lined head.
There is no particular limitation on the driving method of the recording head that is the ink flying means in the image forming process, and it can be selected appropriately according to the purpose. For example, a piezoelectric element actuator using PZT or the like, a method of applying thermal energy In addition, an on-demand type head using an actuator using electrostatic force can be used, or recording can be performed with a continuous ejection type charge control type head.

<Post-treatment liquid application step and post-treatment liquid application means>
The post-processing liquid application step is a step of applying a post-processing liquid to the image forming unit, and is performed by a post-processing liquid application unit.
The purpose of the post-treatment liquid application step is to prevent transfer contamination of the recorded image during conveyance and to prevent the recording medium from blocking.

<< Aftertreatment liquid >>
The post-treatment liquid preferably contains a water-dispersible resin, a water-soluble organic solvent, a penetrating agent, a surfactant, and water, and preferably contains a wax and a polyether-modified silicone oil. Contains ingredients.
Although the post-treatment liquid varies depending on the method of application or flight, it is polymerized by ultraviolet irradiation in order to give the image portion glossiness or to protect the image portion with a resin layer (improvement of glossiness and fixability). The resin composition and thermoplastic resin which contain the component to perform are preferable. In particular, a thermoplastic resin emulsion (also referred to as a water-dispersible resin) is preferable for the purpose of improving glossiness and fixing property. In the case where the post-treatment liquid is caused to fly by the ink jet recording apparatus, it is preferable that an appropriate amount of the water-soluble organic solvent (wetting agent) used in the ink for ink jet and the pretreatment liquid is contained.

-Water dispersible resin-
As said water dispersible resin, the glass transition temperature (Tg) has preferable -30 degreeC or more, and its -20 degreeC-100 degreeC is more preferable. If the glass transition temperature (Tg) is less than −30 ° C., it may be tacky like an adhesive even after evaporation of moisture, making actual use difficult.
The glass transition temperature of the water dispersible resin can be measured by, for example, a TMA method, a DSC method, or a DMA method (tensile method).
The minimum film-forming temperature (MFT) of the water dispersible resin is preferably 50 ° C. or lower, and more preferably 35 ° C. or lower. When the minimum film-forming temperature (MFT) exceeds 50 ° C., the film cannot be formed in a short time even by using a drying means such as a heater or hot air, so that actual use may be difficult.
The minimum film-forming temperature (MFT) of the water-dispersible resin can be measured by, for example, a minimum film-forming temperature measuring device (MFT type).

Examples of the water dispersible resin include acrylic resin, styrene-acrylic resin, urethane resin, acrylic-silicone resin, and fluorine resin. As these water-dispersible resins, those similar to the water-dispersible resins used in the ink can be appropriately selected and used.
The content of the water-dispersible resin in the post-treatment liquid is preferably 1% by mass to 50% by mass, and more preferably 1% by mass to 30% by mass in terms of solid content. If the content exceeds 50% by mass, the viscosity may increase. If the content is less than 1% by mass, the film-forming property is lowered and much energy for water evaporation is required.

  The volume average particle diameter of the water-dispersible resin is related to the viscosity of the post-treatment liquid. For the same composition, the viscosity at the same solid content increases as the particle diameter decreases. The volume average particle diameter of the water-dispersible resin is preferably 50 nm or more so that the viscosity is not excessively high when the post-treatment liquid is used. On the other hand, a particle size of several tens of μm is not preferable because it becomes larger than the nozzle opening of the head of the ink jet recording apparatus that causes the post-treatment liquid to fly. If particles having a large particle diameter are present in the post-treatment liquid even though they are smaller than the nozzle opening, the discharge property is deteriorated. Therefore, the volume average particle diameter of the post-treatment liquid is more preferably 200 nm or less, and even more preferably 150 nm or less, in order not to inhibit the ink discharge properties.

-Wax-
The wax can improve the friction resistance and blocking resistance of an image by being oriented on the image surface.

As the wax, any wax that can be dispersed in water can be used. The wax is preferably a polyethylene wax emulsion having a melting point of 120 ° C. or higher and 140 ° C. or lower. When the melting point is less than 120 ° C., the storage stability of the post-treatment liquid may decrease due to aggregation with the resin fine particles. When the melting point exceeds 140 ° C., the slip effect is reduced, and the image has friction resistance. May decrease.
The particle diameter of the polyethylene wax emulsion is preferably 0.2 μm or less.

  Examples of the polyethylene wax emulsion include AQUACER-515 (manufactured by Big Chemie Japan Co., Ltd.), Polylon P-502 (manufactured by Chukyo Yushi Co., Ltd.) and the like.

  The content of the wax is preferably 1% by mass to 10% by mass, more preferably 1% by mass to 7% by mass, and more preferably 1% by mass with respect to the total amount of the post-treatment liquid, although it depends on the wax used and the purpose of use. -5 mass% is still more preferable.

-Polyether-modified silicone oil-
The post-treatment liquid preferably has a slip property and contains a polyether-modified silicone oil for improving the scratch resistance and blocking resistance of an image.

The polyether-modified silicone oil is obtained by introducing a polyether group into the side chain, terminal, and both of the silicone oil. Moreover, silicone oil is comprised by the linear polymer which consists of a siloxane bond. Examples of the linear polymer comprising a siloxane bond include those in which all of the side chain and both ends are methyl groups. The average degree of polymerization of the linear polymer composed of siloxane bonds is preferably 45 to 230.
Commercially available products can be used as the both-end polyether-modified silicone oil having a polydimethylsiloxane main chain, and specifically, BYK-333, BYK-UV3500 (both manufactured by Big Chemie Japan Co., Ltd.), etc. Is mentioned.
The content of the polyether-modified silicone oil is preferably 0.1% by mass to 5% by mass, more preferably 0.5% by mass to 3% by mass with respect to the total amount of the post-treatment liquid. More preferably, 5% by mass.

There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, antiseptic / antifungal agent, a rust preventive agent, a pH adjuster etc. are mentioned.
As the water-soluble organic solvent, the surfactant, the antiseptic / antifungal agent, the rust inhibitor, and the pH adjuster in the post-treatment liquid, the same ones as in the pre-treatment liquid can be used.

  The post-treatment liquid may be attached over the entire image surface of the recording medium, or may be attached only to a specific portion of the image surface. The method for applying the post-treatment liquid is not particularly limited, and various methods can be appropriately selected depending on the type of the post-treatment liquid, but the same method as the method for applying the pre-treatment liquid or the method for flying the ink is used. Is preferred. Among these, the method similar to the method of flying ink is particularly preferable from the viewpoint of the apparatus configuration and the storage stability of the post-treatment liquid.

Dry coverage of the post-treatment solution is ^{preferably 0.5g / m 2 ~10g / m 2} , more preferably ^{2g / m 2 ~8g / m 2} . When the adhesion amount is less than 0.5 g / m ² , almost no improvement in image quality (image density, saturation, glossiness and fixability) is observed, and when it exceeds 10 g / m ² , the drying property of the protective layer is increased. And the image quality improvement effect is saturated, which is economically disadvantageous.

It is preferable to adjust the viscosity and surface tension of the post-treatment liquid so that the spread of dots after landing is increased.
The post-treatment liquid preferably has a static surface tension at 25 ° C. of 10 mN / m to 35 mN / m, and more preferably 15 mN / m to 30 mN / m or less. When the static surface tension exceeds 35 mN / m, it is difficult to spread on the image, the blocking resistance may be lowered, and the drying time may be prolonged.
The viscosity of the post-treatment liquid is preferably 1.2 mPa · s or more and 15 mPa · s or less, more preferably 1.5 mPa · s or more and less than 10 mPa · s, and further preferably 1.8 mPa · s or more and 8 mPa · s or less. Is less than. When the viscosity exceeds 15 mPa · s, it is difficult to spread on the image and the blocking resistance may be lowered, and when it is less than 1.2 mPa · s, the ejection stability may be lowered.

<Other processes and other means>
Examples of the other steps include a fixing step and a drying step, which are performed by a fixing unit and a drying unit.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of an image forming method and an image forming apparatus of the present invention will be described in detail with reference to the drawings.
Here, FIG. 1 and FIG. 2 are schematic views of an image formed product by the image forming method of the present invention.
In the image formed product, a pretreatment liquid 501 is applied on the entire surface of the recording medium 500, and ink 502 is applied thereon, and an area smaller than the formed image area is formed on the formed image region. Thus, the post-treatment liquid 503 is applied.

FIG. 3 is a schematic diagram of an ink jet recording apparatus to which the present invention is applied. An ink jet recording apparatus 300 to which the present invention is applied includes a recording medium transport unit 301, a preprocessing step unit 302 for applying a pretreatment liquid to the recording medium 203, and a recording medium 203 to which a pretreatment liquid is applied. The pre-processing and post-drying section 303 and the image forming process section 304, the post-processing process section 305 for applying the post-processing liquid to the recording medium after the image forming process, and the recording medium 203 to which the post-processing liquid has been applied is dried. The post-processing drying unit 306 is configured.
The recording medium conveyance unit 301 includes a paper feeding device 307, a plurality of conveyance rollers, and a winding device 308. 3 is continuous paper (roll paper) wound in a roll shape, and the recording medium 203 is unwound from a paper feeding device by a transport roller, and is transported on a platen to be taken up. Is wound up by.
The recording medium 203 conveyed from the recording medium conveyance unit 301 is applied with a pretreatment liquid in a pretreatment process unit 302. In inkjet, when image formation is performed on recording media other than dedicated inkjet paper, quality problems such as bleeding, density, color tone and show-through, and problems related to image robustness such as water resistance and weather resistance have occurred. As a means for solving this problem, a technique for improving image quality by applying a pretreatment liquid having a function of aggregating ink before forming an image on a recording medium is performed.

  The pretreatment step is not particularly limited as long as a coating method in which the above pretreatment liquid is uniformly applied to the surface of the printing paper may be used. Examples of the coating method include a blade coating method, a gravure coating method, a gravure offset coating method, a bar coating method, a roll coating method, a knife coating method, an air knife coating method, a comma coating method, a U comma coating method, an AKKU coating method, Examples thereof include a smoothing coating method, a micro gravure coating method, a reverse roll coating method, a 4 to 5 roll coating method, a dip coating method, a curtain coating method, a slide coating method, and a die coating method.

FIG. 4 is a schematic diagram of the pretreatment process unit 302 in the present embodiment. In this embodiment, the roll coating method will be described, but another pretreatment liquid coating method may be used.
As shown in FIG. 4, the recording medium 203 such as continuous paper is conveyed into the pretreatment liquid applying unit 204 by the conveying roller 201.
A pretreatment liquid 205 is stored in the pretreatment liquid application unit 204, and the pretreatment liquid 205 is transferred to a roller surface of the application roller 208 in a thin film form by a stirring / supply roller 206 and a transfer / thinning roller 207. . Then, the application roller 208 rotates while being pressed against the rotating platen roller 202, and the recording medium 203 passes between them to apply the pretreatment liquid 205 on the surface.
Further, the platen roller 202 can adjust the nip pressure when applying the pretreatment liquid by the pressure adjusting device 209. By changing the nip pressure, the coating amount of the pretreatment liquid 205 can be changed.
Further, the application amount can be adjusted by changing the rotation speed of the application roller 208 and the platen roller 202. The application roller 208 and the platen roller 202 are driven by a power source such as a drive motor (not shown), and the amount of application can be adjusted by changing the rotational speed by changing the energy of the power source.

In this way, the method of applying the pretreatment liquid 205 for improving the image quality to the recording area of the recording medium 203 with the application roller 208 is performed by spraying the processing agent liquid onto the recording medium using the ejection head. Compared with the method to be performed, the pretreatment liquid 205 having a relatively high viscosity can be applied thinly on the recording medium 203, and the image bleeding and the like can be further reduced.
Moreover, you may provide the drying part 303 after a pre-process after an application | coating process like FIG.

The pre-processing and post-drying device in the pre-processing and post-drying unit 303 includes, for example, heat rollers 311 and 312 as shown in FIG. According to this apparatus, the continuous paper coated with the pretreatment liquid is conveyed to the heat roller by the conveyance roller. The heat roller is heated to a high temperature of 50 ° C. to 100 ° C., and the continuous paper coated with the pretreatment liquid evaporates and dries due to contact heat transfer from the heat roller.
On the recording medium after the preprocessing process, an image corresponding to the image data is formed in the image forming process section. The image forming process unit 304 is a full-line head, and four recording heads that can handle black (K), cyan (C), magenta (M), and yellow (Y) from the upstream side in the recording medium conveyance direction. 304K, 304C, 304M, and 304Y are arranged.
For example, as shown in FIG. 5, the black (K) recording head 304K has four head units 304K-1, 304K-2, 304K-3, and 304K-4 arranged in a staggered manner in a direction perpendicular to the conveying direction. This ensures the print area width.

FIG. 6 is an enlarged view of the head unit 304K-1. As shown in FIG. 6, a large number of print nozzles 310 are arranged on the nozzle surface 309 of 304K-1 along the longitudinal direction of the head unit 304K-1, thereby forming a nozzle row. In this embodiment, the number of nozzle rows is one, but a plurality of rows can be provided. The other recording heads 304C, 304M, and 304Y have the same configuration, and the four recording heads 304K, 304C, 304M, and 304Y are arranged in the transport direction while maintaining the same pitch. As a result, it is possible to form an image over the entire print area width in a single recording operation.
The post-processing liquid is applied to the recording medium after the image forming process by the post-processing process unit 305. This post-treatment liquid described later contains a component capable of forming a transparent protective layer on the recording medium.
In the post-processing step in the present embodiment, the image is applied only to specific portions of the image forming area and the non-image forming area of the recording medium. It is preferable to apply an optimal amount according to the color of the ink forming the image. More preferably, the coating amount and the coating method may be changed according to the type and resolution of the recording medium. The area of the post-treatment liquid on the recording medium varies depending on the type of the recording medium. However, with the same recording medium, the area of the post-treatment liquid increases as the application amount of the post-treatment liquid increases.

The method for applying the post-treatment liquid is not particularly limited, and various methods are appropriately selected depending on the type of the post-treatment liquid. The same method as the method for applying the pre-treatment liquid or the above inkjet ink is used. Any of the methods similar to the method used can be preferably used. Among these, a method similar to the method of flying an inkjet ink is particularly preferable from the viewpoint of the apparatus configuration and the storage stability of the post-treatment liquid. In this post-process includes the steps of dry coverage in the image formed surface to form a protective layer by applying a post-treatment liquid containing a transparent resin so as to 0.5g ^/ m ² ~10g / m 2 is there.
Dry coverage of the post-treatment solution is ^{preferably 0.5g / m 2 ~10g / m 2} , more preferably ^{2g / m 2 ~8g / m 2} . When the dry adhesion amount is less than 0.5 g / m ² , image quality (image density, saturation, glossiness and fixability) is hardly improved, and when it exceeds 10 g / m ² , Since the drying property is lowered and the effect of improving the image quality is saturated, it is economically disadvantageous.

Further, the post-processing section may be provided with a post-processing post-drying section 306 as shown in FIG.
The post-processing post-drying device in the post-processing post-drying unit 306 includes, for example, heat rollers 313 and 314 as shown in FIG. According to this apparatus, the continuous paper coated with the post-treatment liquid is transported to the heat roller by the transport roller. The heat roller is heated to a high temperature, and the continuous paper coated with the post-treatment liquid is dried due to evaporation of moisture by contact heat transfer from the heat roller. The drying means is not limited to this, and an infrared drying device, a microwave drying device, hot air, etc. can also be applied. Instead of using a single device, for example, a heat roller and a hot air device are combined. May be.

<Description of Control System of Inkjet Recording Apparatus>
Hereinafter, an embodiment of a printing system according to the present invention will be described in detail with reference to the accompanying drawings.
First, for easy understanding, production printing to which the printing system according to the present embodiment is applied will be schematically described. In production printing, the basic idea is to perform a large amount of printing in a short time. For this reason, in production printing, in order to speed up printing and efficiently manage jobs and print data, a workflow system that manages from creation of print data to distribution of printed materials is constructed. .
The printing system according to the present embodiment relates to a part that executes printing in the workflow of production printing. The RIP (Raster Image Processor) process and the printing of bitmap data obtained by the RIP process are separate apparatuses. To do. The RIP process takes the longest processing time in the printing process, and the printing speed can be increased by separating the apparatus that performs the RIP process from the apparatus that performs the printing process.

<Outline of Printing System Applicable to Embodiment>
FIG. 7 shows an exemplary configuration of a printing system applicable to the embodiment of the present invention. This printing system is configured by connecting a host device 10 and a printer device 13 as a printing device by a plurality of data lines 11 and control lines 12. The host device 10 performs RIP processing in accordance with print job data supplied from the host device, and creates bitmap data for each color, which is print image data. At the same time, the upper level apparatus 10 creates control information for controlling the printing operation based on the print job data, host apparatus information, and the like.
The print image data for each color created by the host device 10 is supplied to a printer engine unit (not shown) of the printer device 13 via a plurality of data lines 11. Control information is transmitted and received between the upper level apparatus 10 and the printer controller 14 via the control line 12. The printer controller 14 controls the printer engine unit based on the transmission / reception of the control information, and executes printing according to the print job.

  The printing method is not particularly limited and can be appropriately selected according to the purpose. In the present embodiment, a print image is formed on a printing paper by an inkjet method. The printing paper is a continuous paper (continuous form) which is a continuous paper in which perforable perforations are struck at a predetermined interval. In production printing, this continuous paper is often used as printing paper. Needless to say, the present invention is not limited to this, and a cut sheet having a fixed size such as A4 size or B4 size may be used as the printing paper. In the continuous paper, a page refers to, for example, an area sandwiched between perforations punched at a predetermined interval.

<High-level device>
FIG. 8 is an example of the configuration of the higher-level device 10. A CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, and a hard disk drive (HDD) 104 are connected to the bus 100. An external I / F 110, a control information I / F 111, and an image data I / F 112 are further connected to the bus 100. These units connected to the bus 100 can communicate with each other via the bus 100.
The ROM 102 and the HDD 104 store programs for operating the CPU 101 in advance. The RAM 103 is used as a work memory for the CPU 101. That is, the CPU 101 controls the overall operation of the host device 10 using the RAM 103 as a work memory in accordance with programs stored in the ROM 102 and the HDD 104.

  The external I / F 110 corresponds to, for example, TCP / IP (Transmission Control Protocol / Internet Protocol) and controls communication with the host device. The control information I / F 111 controls communication of control information. The image data I / F 112 controls communication of print image data and has a plurality of channels. For example, the print image data of each color by colors Y (Yellow), C (Cyan), M (Magenta), and K (Black) created in the host device 10 is output from each of the plurality of channels. Since the image data I / F 112 is required to have a high transfer rate, for example, PCI Express (Peripheral Component Interconnect Bus Express) is used. The method of the control information I / F 111 is not particularly limited, but here, as with the image data I / F 112, PCI Express is used.

  In such a configuration, print job data transmitted from the host device is received by the external I / F 110 of the host device 10 and stored in the HDD 104 via the CPU 101. The CPU 101 performs RIP processing based on the print job data read from the HDD 104, generates bitmap data for each color, and writes it to the RAM 103. For example, the CPU 101 renders PDL (Page Description Language) by RIP processing, generates bitmap data of each color, and writes it to the RAM 103. The CPU 101 compresses and encodes the bitmap data of each color written in the RAM 103 and temporarily stores it in the HDD 104.

  For example, when the printing operation is started in the printer device 13, the CPU 101 reads out the bitmap data of each color compressed and encoded from the HDD 104, decodes the compressed code, and outputs the decompressed bitmap data of each color. Each is written in the RAM 103. Then, the CPU 101 reads out the bitmap data of each color from the RAM 103, outputs it from each channel of the image data I / F 112 as print image data of each color, and supplies it to the printer device 13. Further, the CPU 101 transmits / receives control information to / from the printer device 13 via the control information I / F 111 according to the progress of the printing operation.

(Printer device)
FIG. 9 shows an example of the configuration of the printer device 13. The printer device 13 includes a printer controller 14 and a printer engine 15. The printer controller 14 is connected to the control line 12 and controls the printing operation by transmitting / receiving control information to / from the host apparatus 10 via the control line 12. The printer engine 15 is connected to a plurality of data lines 11a, 11b, 11c, 11d, and 11e. Under the control of the printer controller 14, the upper level device 10 is connected via the data lines 11a, 11b, 11c, 11d, and 11e, respectively. The printing process is performed based on the print image data of each color and post-processing liquid transferred from.

  The printer controller 14 and the printer engine 15 will be described in more detail. The printer controller 14 includes a CPU 21 and a print control unit 22, and the CPU 21 and the print control unit 22 are connected to the bus 20 so that they can communicate with each other. The control line 12 is also connected to the bus 20 via a communication I / F (not shown). The CPU 21 operates in accordance with a program stored in a ROM (not shown) and controls the overall operation of the printer device 13. The print control unit 22 transmits / receives commands and status information to / from the printer engine 15 based on transmission / reception of control information to / from the host device 10 via the control line 12 to control the operation of the printer engine 15. To do.

The printer engine 15 includes a plurality of data management units 30a, 30b, 30c, 30d, and 30e, an image output unit 50 that outputs an image based on print image data to form a sheet, and controls conveyance of the print sheet. And a post-processing liquid output unit 52 and a post-processing post-drying control unit 53.
Data lines 11a, 11b, 11c, 11d, and 11e are connected to the data management units 30a, 30b, 30c, 30d, and 30e, respectively. In addition, the data management units 30a, 30b, 30c, 30d, and 30e include memories 31a, 31b, 31c, 31d, and 31e, respectively, from the host device 10 via the data lines 11a, 11b, 11c, 11d, and 11e. The transferred print image data of each color and post-treatment liquid is stored in the memories 31a, 31b, 31c, 31d and 31e, respectively.

Each of these memories 31a, 31b, 31c, 31d and 31e has a capacity capable of storing print image data for at least three pages. The print image data for three pages corresponds to, for example, the print image data of the page being transferred from the upper level device 10, the print image data of the page currently being output, and the print image data of the next page.
Further, the data management units 30a, 30b, 30c, 30d, and 30e are connected to the print control unit 22 by engine control lines 40a, 40b, 40c, 40d, and 40e, respectively. The print control unit 22 can individually transmit and receive control signals to and from the data management units 30a, 30b, 30c, 30d, and 30e via the engine control lines 40a, 40b, 40c, 40d, and 40e. it can.

FIG. 10 shows an exemplary configuration of the data management unit 30a. Since the data management units 30a, 30b, 30c, 30d, and 30e can apply a common configuration, in FIG. 10, the data management units 30a, 30b, 30c, and 30d are represented by the data management unit 30a. The configuration is shown.
The data management unit 30a includes a memory 31a and a logic circuit 32a. The engine control line 40a and the data line 11a are connected to the logic circuit 32a. The logic circuit 32a stores the print image data transferred from the upper level device 10 via the data line 11a in the memory 31a according to the control signal received from the print control unit 22 via the engine control line 40a. Similarly, the logic circuit 32a reads print image data from the memory 31a in accordance with a control signal received from the print control unit 22 via the engine control line 40a, and supplies the print image data to the image output unit 50 described later.

Note that the control by the logic circuit 32a configured in hardware by a combination of logic circuits and the like has an advantage that higher-speed processing is possible compared to control using a CPU that branches processing by interruption to a program. is there. For example, the logic circuit 32a performs logic determination on a control signal based on a bit string received via the engine control line 40a, and determines a process to be executed.
The print image data of each color and post-processing liquid output from the data management units 30a, 30b, 30c, 30d, and 30e, respectively, is supplied to the image output unit 50 and the post-processing liquid output unit 52. The image output unit 50 executes printing using print image data of each color. The post-processing liquid output unit 52 executes printing using the print image data of the post-processing liquid. In the present embodiment, printing based on print image data is performed by an ink jet method in which printing is performed by ejecting ink from nozzles provided in the head. Of course, the printing method is not limited to the ink jet method, and for example, a laser printer method or the like may be used.

  FIG. 11 shows an exemplary configuration of the image output unit 50. The image output unit 50 includes an output control unit 55 and heads 56a, 56b, 56c, and 56d for the colors C, M, Y, and K. The output control unit 55 connects the output lines 32a, 32b, 32c, and 32d to which the print image data of the data management units 30a, 30b, 30c, and 30d are output and the heads 56a, 56b, 56c, and 56d. Control. In other words, the output control unit 55 can set a path so that each head 56a, 56b, 56c, and 56d can select and connect 1 to each of the output lines 32a, 32b, 32c, and 32d. Although not shown here, the post-processing liquid output unit 52 is also configured to perform printing with the head, and thus can be configured similarly to the image output unit 50.

For example, the output control unit 55 can set the output lines 32a, 32b, 32c, and 32d and the heads 56a, 56b, 56c, and 56d to be connected one-to-one. Further, for example, the output lines 32a, 32b, 32c, and 32d and the heads 56a, 56b, 56c, and 56d are connected to the output line 32a by connecting the heads 56a, 56b, 56c, and 56d. Can be set to connect to many.
The path connecting each output line 32a, 32b, 32c and 32d and each head 56a, 56b, 56c and 56d can be set by a user operation using, for example, a dip switch. Not limited to this, the path may be set by a control signal (not shown) from the print control unit 22.

  As described above, in the printer device 13 according to the present embodiment, transfer of print image data from the host device 10 and transmission / reception of a control signal for controlling printing by the print image data between the host device 10 and the printer device 13 are performed. Are performed via different paths. Further, the print image data of each color is transferred from the host device 10 via different data lines 11a, 11b, 11c and 11d, and each color transferred via these data lines 11a, 11b, 11c and 11d is transferred. The print image data is controlled independently of each other and supplied to the data management units 30a, 30b, 30c, and 30d having a common configuration. Further, in the image output unit 50, the connection paths between the outputs of the data management units 30a, 30b, 30c and 30d and the heads 56a, 56b, 56c and 56d of the respective colors can be set by a user operation or the like.

Therefore, the printer device 13 according to the present embodiment depends on the number of colors of print image data (four colors of C, M, Y, and K, or only K colors) and the number of heads used in the image output unit 50. The configuration of the printer engine 15 can be easily changed. At this time, the printer engine 15 can be provided with only the data management units 30a, 30b, 30c, and 30d that are required according to the required configuration.
For example, when it is desired to perform full-color printing with four colors C, M, Y, and K, the data management units 30a, 30b, 30c, and 30d are all provided for the printer engine 15, and the output control unit 55 What is necessary is just to connect each output of the management parts 30a, 30b, 30c, and 30d to the heads 56a, 56b, 56c, and 56d, respectively. Further, for example, when printing with one color K, as an apparatus cost priority, only one data management unit 30a and head 56a are provided, and the output control unit 55 outputs the data management unit 30a to the head 56a. Can be connected. Further, for example, when printing with one color K, as a priority for the printing speed, one data management unit 30a and four heads 56a, 56b, 56c, and 56d are provided, and the output control unit 55 includes a data management unit. The output of 30a can be connected to heads 56a, 56b, 56c and 56d, respectively. In this case, since the same color is printed a plurality of times, the ink ejection time at each of the heads 56a, 56b, 56c and 56d is set to 1/4 of the normal time, and the conveyance speed of the printing paper is set to normal. It is conceivable to perform high-speed printing at four times as high.

Next, a detailed description of each process will be given.
<Head structure>
Next, an example of a droplet discharge head constituting the recording head in this image forming apparatus will be described with reference to FIGS.
12 is a cross-sectional explanatory view along the longitudinal direction of the liquid chamber of the head, and FIG. 13 is a cross-sectional explanatory view of the head along the short side of the liquid chamber (nozzle arrangement direction).

  The droplet discharge head includes a flow path plate 401 formed by anisotropic etching a single crystal silicon substrate, for example, and a vibration plate 402 formed by nickel electroforming, for example, bonded to the lower surface of the flow path plate 401. A nozzle plate 403 bonded to the upper surface of the flow path plate 401 and laminating them, and a nozzle communication path 405 and a liquid chamber 406, which are flow paths through which the nozzles 404 for discharging liquid droplets (ink droplets) communicate with each other. An ink supply port 409 communicating with the common liquid chamber 408 for supplying ink to the liquid chamber 406 is formed.

In addition, two rows (only one row is shown in FIG. 13) of stacked piezoelectric elements as electromechanical conversion elements that are pressure generating means (actuator means) for pressurizing ink in the liquid chamber 406 by deforming the diaphragm 402. An element 421 and a base substrate 422 to which the piezoelectric element 421 is bonded and fixed are provided. Note that a column portion 423 is provided between the piezoelectric elements 421.
The column portion 423 is a portion formed at the same time as the piezoelectric element 421 by dividing the piezoelectric element member. However, since the drive voltage is not applied, the column portion 423 becomes a simple column.

Further, an FPC cable 222 for connecting to a drive circuit (drive IC) (not shown) is connected to the piezoelectric element 421.
Then, the peripheral edge of the diaphragm 402 is joined to the frame member 430, and the frame member 430 serves as a through-hole 431 and a common liquid chamber 408 that accommodates an actuator unit including the piezoelectric element 421 and the base substrate 422. A recess and an ink supply hole 432 for supplying ink from the outside to the common liquid chamber 408 are formed. The frame member 430 is made of, for example, a thermosetting resin such as an epoxy resin or polyphenylene sulfite by injection molding.

Here, the flow path plate 401 is formed by, for example, anisotropically etching a single crystal silicon substrate having a crystal plane orientation (110) using an alkaline etching solution such as an aqueous potassium hydroxide solution (KOH), thereby the nozzle communication path 405. However, the liquid chamber 406 is formed with a recess or a hole, but is not limited to a single crystal silicon substrate, and other stainless steel substrates or photosensitive resins can also be used.
The diaphragm 402 is formed of a nickel metal plate, and is manufactured by, for example, an electroforming method (electroforming method). In addition, a metal plate or a joining member between a metal and a resin plate is used. You can also. The piezoelectric element 421 and the column 423 are bonded to the diaphragm 402 with an adhesive, and the frame member 430 is bonded to the diaphragm 402 with an adhesive.

The nozzle plate 403 forms a nozzle 404 having a diameter of 10 μm to 30 μm corresponding to each liquid chamber 406 and is bonded to the flow path plate 401 with an adhesive. This nozzle plate 403 is formed by forming a water repellent layer on the outermost surface through a required layer on the surface of a nozzle forming member made of a metal member.
The piezoelectric element 421 is a stacked piezoelectric element (here, PZT) in which piezoelectric materials 451 and internal electrodes 452 are alternately stacked. An individual electrode 453 and a common electrode 454 are connected to each internal electrode 452 drawn to the alternately different end faces of the piezoelectric element 421.
In this embodiment, the ink in the liquid chamber 406 is pressurized using the displacement in the d33 direction as the piezoelectric direction of the piezoelectric element 421. However, the pressure in the d31 direction is used as the piezoelectric direction of the piezoelectric element 421. The ink in the liquid chamber 406 may be pressurized. Alternatively, a structure in which one row of piezoelectric elements 421 is provided on one substrate 422 may be employed.

In the droplet discharge head configured in this way, for example, the piezoelectric element 421 contracts by lowering the voltage applied to the piezoelectric element 421 from the reference potential, and the diaphragm 402 descends to expand the volume of the liquid chamber 406. As a result, ink flows into the liquid chamber 406, and then the voltage applied to the piezoelectric element 421 is increased to extend the piezoelectric element 421 in the stacking direction, and the diaphragm 402 is deformed in the direction of the nozzle 404 to change the volume of the liquid chamber 406. / By contracting the volume, the ink in the liquid chamber 406 is pressurized, and ink droplets are ejected (ejected) from the nozzle 404.
Then, by returning the voltage applied to the piezoelectric element 421 to the reference potential, the diaphragm 402 is restored to the initial position, and the liquid chamber 406 expands to generate a negative pressure. Ink 406 is filled.
Therefore, after the vibration of the meniscus surface of the nozzle 404 is attenuated and stabilized, the operation proceeds to the next droplet discharge.
Note that the driving method of the head is not limited to the above-described example (drawing-pushing), and it is also possible to perform striking and pushing depending on the direction to which the drive waveform is given.

  In this example, a piezoelectric element is used as a pressure generating means for pressurizing the ink in the ink flow path, and the diaphragm that forms the wall surface of the ink flow path is deformed to change the volume in the ink flow path to eject ink droplets. The so-called piezo type is applied (refer to Japanese Patent Laid-Open No. 2-51734), but a so-called thermal type that generates bubbles by heating ink in the ink flow path using a heating resistor (Japanese Patent Laid-Open No. 2-51734). Sho 61-59911), the diaphragm and the electrode forming the wall surface of the ink flow path are arranged opposite to each other, and the diaphragm is deformed by the electrostatic force generated between the diaphragm and the electrode, thereby allowing the ink flow. An electrostatic type (see JP-A-6-71882) that discharges ink droplets by changing the volume in the path can also be applied.

Next, an embodiment of the present invention will be described. In the embodiment, an image forming apparatus in which the pretreatment liquid is applied by a roller and the posttreatment liquid is applied by droplet flight by a droplet discharge head will be described.
First, the first embodiment will be described.
FIG. 14 is a flowchart of this embodiment. Of the control information transmitted from the host device 10 (not shown), the present invention performs post-treatment liquid application amount control from information relating to the color of the print image. The optimal amount of post-processing liquid applied for each color may be stored in advance on the printer device side and applied in accordance with the image data.
In addition, by inputting the physical properties (paper material properties, paper thickness, basis weight) of the recording media to be used into the host device 10, the penetrability at the time of printing is calculated, and the optimum pretreatment liquid and posttreatment liquid are calculated. It is also possible to calculate the applied amount. The input of this information is stored in advance on the printer device side for the main recording media, and the data can be called by inputting the paper type name. On the other hand, it is also possible to add a new one on the user side.
Further, in the present embodiment, the recording media information is transferred from the host device 10, but an external input device may be mounted on the printer device 13 and the recording media information may be transmitted by external input therefrom.

Next, for example, information on the permeability of the recording medium is read from the recording medium information transmitted to the printer device 13 in the print control unit 22, and the amount of pretreatment liquid applied is calculated from the numerical value of the permeability. . Information regarding the pretreatment liquid application amount is transmitted to the pretreatment liquid application control unit 60, and is converted into information on the difference nip pressure for applying the pretreatment liquid. When the information on the nip pressure is sent to the pretreatment device 302, the pressure is adjusted by the pressure adjustment device 209, and the calculated amount of the pretreatment liquid can be applied.
Further, the application amount may be adjusted by the rotation speed of the application roller. In this case, the information on the application amount transmitted to the pretreatment application control unit 60 is converted into information on the driving energy of the motor that rotates the roller.
The applied amount of the pretreatment liquid may be other physical properties as long as it is a physical property value related to the cohesiveness of the ink on the recording medium in addition to the information on the permeability.

Next, the application amount of the post-treatment liquid is calculated in the print control unit according to the application amount of the pre-treatment liquid. Since the fixability on the recording medium is affected by the application of the pretreatment liquid, the optimum amount of the posttreatment liquid can be applied by applying the posttreatment liquid according to the application amount of the pretreatment liquid. Is possible.
The post-treatment liquid application amount information calculated by the print control unit is sent to the post-treatment liquid data management unit via the control line 40e, and the post-treatment liquid image data transmitted to the data management unit is corrected. Thus, the application amount of the post-treatment liquid is controlled.
When the post-treatment liquid application is droplet ejection by the recording head, the output energy information is transmitted to the post-treatment liquid ejection head, which is changed to a voltage value applied to the piezoelectric element 421, and the voltage is applied by the piezoelectric element. Pressure is applied and a desired amount of post-treatment liquid is discharged.
Furthermore, you may control the intensity | strength of a drying part according to the provision amount of this pre-processing liquid and a post-processing liquid.

When controlling the drying unit, the pretreatment liquid and posttreatment liquid application amount information calculated by the printing control unit is transmitted via the control lines 41b and 41d, the pretreatment postdrying control unit, and the posttreatment postdrying control. Sent to the department.
When control is performed to reduce the amount of pretreatment liquid and posttreatment liquid applied, power consumption can be reduced by reducing the strength of drying after pretreatment and drying after posttreatment. Is calculated by the post-processing post-drying control unit and the post-processing post-drying control unit.
For example, when drying after pretreatment is performed by a heat roller, the strength of drying after pretreatment is controlled by controlling the temperature of the heat roller.
Moreover, when performing post-processing post-drying by ventilation, the strength of post-processing post-drying is controlled by controlling the temperature and speed of the wind.

Next, a specific treatment liquid application pattern will be described.
A large application amount of the pretreatment liquid means an adhesion amount of 1.5 g / m ² or more.
A large application amount of the post-treatment liquid means an application amount of 1.2 g / m ² or more.
A small amount of each treatment solution applied means other than the above.
Note that “less applied amount” includes “not applied”.
For example, when printing on ink jet exclusive paper having good permeability, the amount of pretreatment liquid may be small. Accordingly, the amount of post-treatment liquid may be reduced accordingly. Also, the drying strength may be weak.
Next, when printing on offset printing paper having poor permeability, it is necessary to apply a large amount of pretreatment liquid. Accordingly, it is necessary to apply a large amount of post-treatment liquid. It is also necessary to increase the drying strength.
In this embodiment, the amount of treatment liquid applied is two types, “large” and “small”. However, the physical properties of the recording medium may be finely classified to increase the coating pattern of the treatment liquid.

Next, the application amount of the pretreatment liquid and the bleeding suppression effect will be described.
FIG. 15 is a diagram showing the relationship between the pretreatment liquid application amount and granularity of a certain recording medium. It can be seen that the granularity decreases by applying the pretreatment liquid.
FIG. 16 shows the relationship between the permeability of the recording medium and the required amount of pretreatment liquid. In FIG. 16, the necessary pretreatment liquid application amount is defined as an amount with sufficiently high quality, for example, a minimum pretreatment liquid application amount with which the granularity is equal to or less than the broken line. When the permeability of the recording medium is small, the necessary amount of the pretreatment liquid is increased. When the permeability is increased, the necessary amount of the pretreatment liquid is decreased. Therefore, the optimum amount of pretreatment liquid applied can be determined from the permeability of the recording medium.

FIG. 17 is a diagram showing the relationship between the amount of pretreatment liquid applied to a recording medium and the abrasion resistance. By applying the pretreatment liquid, the fixing property is deteriorated.
FIG. 18 is a diagram showing the relationship between the amount of post-treatment liquid applied to a certain recording medium and the abrasion resistance.
As shown in FIGS. 17 and 18, the fixability reduced by the pretreatment liquid is improved by applying the posttreatment liquid. Costs can be reduced by reducing the amount of post-treatment liquid with a recording medium that requires little pre-treatment liquid. Further, by increasing the amount of the pretreatment liquid and the amount of the posttreatment liquid, it is possible to produce an image formed with excellent image quality and image fastness even with a recording medium having poor permeability.

  By the above method, the application amount of the pretreatment liquid is calculated from the permeability of the recording medium, and the application amount of the posttreatment liquid is calculated accordingly. It is possible to produce an excellent image formation with the lowest cost.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Preparation Example 1)
<Preparation of pretreatment liquid A1>
The following composition was stirred for 1 hour and mixed uniformly. The remaining amount of water was added to the obtained mixed solution so as to be 100% by mass in total and stirred for 1 hour. Subsequently, pressure filtration was performed with a cellulose acetate membrane filter having an average pore diameter of 0.8 μm to remove coarse particles, thereby preparing a pretreatment liquid A1.
[Composition of pretreatment liquid A1]
・ 1,3-butanediol: 10% by mass
・ L-lactic acid: 15% by mass
-Fluorosurfactant (Polyfox PF-151N, manufactured by Daikin Industries) ... 0.05% by mass
-Antifoaming agent (silicone KM-72F, manufactured by Shin-Etsu Silicone) 0.05% by mass
・ 2-Amino-2-ethyl-1,3-propanediol ... 0.1% by mass
・ N, N-diethylethanolamine: 23.42% by mass
・ Calcium lactate: 5% by mass
Surfactant (RF-O-polyoxyethylene ether, manufactured by Neos, Footage 251) ... 0.1% by mass
-Polyether-modified silicone compound (KF-643, manufactured by Shin-Etsu Chemical Co., Ltd.) ... 1% by mass
Antifungal agent (1,2-benzisothiazolin-3-one dipropylene glycol 20% aqueous solution, manufactured by Arch Chemicals Japan, Proxel GXL) 0.05% by mass
・ 1,2,3-benzotriazole ... 0.1% by mass
・ Ion exchange water

(Preparation Example 2)
<Preparation of cyan pigment dispersion>
After sufficiently replacing the inside of the 1 L flask equipped with a mechanical stirrer, thermometer, nitrogen gas introduction tube, reflux tube, and dropping funnel with nitrogen gas, 11.2 g of styrene, 2.8 g of acrylic acid, 12.0 g of lauryl methacrylate Then, 4.0 g of polyethylene glycol methacrylate, 4.0 g of styrene macromer (manufactured by Toa Gosei Co., Ltd., trade name: AS-6) and 0.4 g of mercaptoethanol were charged and heated to 65 ° C. Next, 100.8 g of styrene, 25.2 g of acrylic acid, 108.0 g of lauryl methacrylate, 36.0 g of polyethylene glycol methacrylate, 60.0 g of hydroxyethyl methacrylate, styrene macromer (trade name: AS-6, manufactured by Toagosei Co., Ltd.) A mixed solution of 36.0 g, mercaptoethanol 3.6 g, azobisdimethylvaleronitrile 2.4 g, and methyl ethyl ketone 18 g was dropped into the flask over 2.5 hours.
After completion of dropping, a mixed solution of 0.8 g of azobisdimethylvaleronitrile and 18 g of methyl ethyl ketone was dropped into the flask over 0.5 hours. After aging at 65 ° C. for 1 hour, 0.8 g of azobisdimethylvaleronitrile was added, and further aging was performed for 1 hour. After completion of the reaction, 364 g of methyl ethyl ketone was added to the flask to obtain 800 g of a polymer solution having a concentration of 50% by mass.
A part of the obtained polymer solution was dried and measured by gel permeation chromatography (standard: polystyrene, solvent: tetrahydrofuran). The weight average molecular weight was 15,000.

Next, 28 g of the obtained polymer solution, 26 g of copper phthalocyanine pigment, 13.6 g of 1 mol / L potassium hydroxide aqueous solution, 20 g of methyl ethyl ketone, and 30 g of ion-exchanged water were sufficiently stirred.
Thereafter, the mixture was kneaded 20 times using a three-roll mill (manufactured by Noritake Company, trade name: NR-84A). The obtained paste was put into 200 g of ion-exchanged water and stirred sufficiently, and then methyl ethyl ketone and water were distilled off using an evaporator to obtain 160 g of a cyan pigment-containing polymer fine particle dispersion having a solid content of 20.0% by mass. It was.
When the volume average particle diameter of the obtained cyan pigment-containing polymer fine particles was measured with Microtrac UPA (manufactured by Microtrad), the volume average average particle diameter was 98 nm.

(Preparation Example 3)
<Preparation of magenta pigment dispersion>
A magenta pigment-containing polymer fine particle dispersion was obtained in the same manner as in the preparation of the cyan dispersion except that the copper phthalocyanine pigment of the cyan dispersion was changed to Pigment Pigment Red 122.
When the volume average particle size of the obtained magenta pigment-containing polymer fine particles was measured with Microtrac UPA (manufactured by Microtrad), the volume average particle size was 124 nm.

(Preparation Example 4)
<Preparation of yellow pigment dispersion>
A yellow pigment-containing polymer fine particle dispersion was obtained in the same manner as in the preparation of the cyan dispersion except that the copper phthalocyanine pigment of the cyan dispersion was changed to Pigment Pigment Yellow 74.
The volume average particle diameter of the obtained yellow pigment-containing polymer fine particles was measured by Microtrac UPA (manufactured by Microtrad) and found to be 78 nm.

(Preparation Example 4)
<Preparation of black pigment dispersion>
A black pigment-containing polymer fine particle dispersion was obtained in the same manner as in the preparation of the cyan dispersion except that the copper phthalocyanine pigment of the cyan dispersion was changed to carbon black (manufactured by Degussa, FW100).
The volume average particle diameter of the obtained black pigment-containing polymer fine particles was measured by Microtrac UPA (manufactured by Microtrad) and found to be 110 nm.

(Production Examples 1-4)
-Manufacture of ink-
1,3-butanediol, glycerin, anionic fluorine-based surfactant (manufactured by OMNOVA, Polyfox PF-151N), octanediol and other components shown in Table 1 are mixed and stirred for 1 hour to mix uniformly. To do.
The cyan, magenta, yellow, and black pigment dispersions were added to the mixed solution, and the remaining amount of water was added so that the total amount was 100% by mass, followed by stirring for 1 hour.
Thereafter, pressure filtration was performed with a cellulose acetate membrane filter having an average pore diameter of 0.8 μm to remove coarse particles, and inks 1 to 4 were produced.

<Preparation of post-treatment liquid B1>
The following composition was stirred for 1 hour and mixed uniformly. The remaining amount of water was added to the obtained mixed solution so that the total amount was 100% by mass, and the mixture was stirred for 1 hour. Then, pressure filtration was performed with a cellulose acetate membrane filter having an average pore diameter of 0.8 μm to remove coarse particles, thereby preparing a post-treatment liquid B1.
[Composition of post-treatment liquid B1]
・ 3-Methyl-1,3-butanediol ... 22% by mass
・ Glycerin: 11% by mass
-Fluorosurfactant (Polyfox PF-151N, manufactured by Daikin Industries) ... 0.05% by mass
-Antifungal agent (Proxel GXL, manufactured by Abyssinia) ... 0.05% by mass
-Antifoaming agent (silicone KM-72F, manufactured by Shin-Etsu Silicone) 0.05% by mass
・ 2-Amino-2-ethyl-1,3-propanediol: 0.2% by mass
-Polyurethane resin emulsion (SU-100N, manufactured by Chuo Rika Kogyo Co., Ltd.) ... 15% by mass
・ Polyethylene wax (AQUACER-515, manufactured by Big Chemie Japan) ... 14% by mass
-Polyether-modified silicone oil (BYK-333, manufactured by Big Chemie Japan) ... 1% by mass
・ Ion exchange water

(Examples 1-10 and Comparative Examples 1-3)
<Image formation>
As shown in Tables 2 to 4, the pretreatment liquid A1 was applied to a recording medium (OK topcoat +, manufactured by Oji Paper Co., Ltd., offset printing paper) by a roller coating method, and the amount of pretreatment liquid applied was 40 mg / Pre-treatment was performed by applying any of A4 size, 20 mg / A4 size, and 60 mg / A4 size.
Next, using each inkjet ink shown in Tables 2 to 4, images necessary for each evaluation were formed by an inkjet printer (IPSioGXe3300, manufactured by Ricoh Co., Ltd.).
After the image formation, as shown in Tables 2 to 4, the post-treatment liquid B1 is applied to the ink-jet printer, and the amount of the post-treatment liquid per unit area is the volume with respect to the amount of ink applied per unit area. % Was changed to give a post-treatment liquid. Thereafter, heat treatment was performed. The heat treatment was performed at a roller temperature of 100 ° C. from the back side of the printing surface.

  Various characteristics of the obtained images were evaluated as follows. The results are shown in Tables 2-4.

<Glossiness>
In accordance with JIS K7105-1981, using a gloss meter (BYK Gardener, 4501), the image forming part before and after applying the post-treatment liquid and the non-image forming part (recording media background part) of 60 degrees The glossiness (glossiness at an incident angle of 60 degrees) was measured, and the difference in glossiness between the image forming portion and the non-image forming portion was determined and evaluated according to the following criteria.
〔Evaluation criteria〕
A: Glossiness difference is less than 10 ° B: Glossiness difference is 10 ° or more and less than 15 ° △: Glossiness difference is 15 ° or more and less than 20 ° ×: Glossiness difference is 20 ° or more

<Blocking resistance>
Referring to the TAPPI T477 test method issued by the Japan Pulp and Paper Technology Association, immediately after printing the 6 cm square solid part of the printed recording medium on a 10 cm square glass plate, A 10 cm square glass plate was further placed thereon, a load of 1 kg / m ² was applied, and the plate was allowed to stand at 40 ° C. and 90% RH for 24 hours.
Thereafter, it was left at room temperature for 2 hours, and the state of sticking of the recording media when peeled off was visually observed and evaluated according to the following evaluation criteria.
〔Evaluation criteria〕
A: No blocking (No sticking or adhesion occurs on the adjacent surfaces, they can slide freely, and the surface of the sample is not damaged at all)
○: Slightly blocking and slightly sticking (adjacent surface cannot be slid freely, but can be slid by rubbing, and the surface of the sample may be slightly damaged, but cannot be discriminated. )
(Triangle | delta): There exists considerable blocking (adjacent surface sticks or adhere | attaches, each layer is not pulled apart easily, and the surface is damaged or is partially broken.)
X: Completely blocking (the degree of blocking is completely tightly fused between adjacent surfaces, and if it is pulled apart, the sample is broken and the fibers of the base paper are peeled)

<Smear fixability>
For a solid image printed at 100 duty of 6 cm square as an image chart, a solid image portion printed with a white cotton cloth (manufactured by Toyo Seiki Co., Ltd.) attached to a clock meter (manufactured by Toyo Seiki Co., Ltd.) after 10 hours or more has elapsed after printing. The ink was smeared back and forth, and the smudges of the ink adhering to the white cotton cloth were visually observed and evaluated according to the following criteria.
〔Evaluation criteria〕
◎: There is no dirt. ○: There is dirt, but there is no problem in practical use. △: Dirt is slightly noticeable. X: Dirt is noticeable.

“Applied amount of post-processing liquid (image forming portion) (volume% relative to applied amount of ink)” and “Applied amount of post-processing liquid (non-image forming portion)” (volume% relative to applied amount of ink) in Tables 2 to 4 ) "Is the amount of post-treatment liquid applied when the amount of ink required to form an image (solid image) for applying ink to the entire surface of the paper including the non-image forming portion is 100%. , Represents the applied amount (volume%) of the post-treatment liquid.
When the post-processing liquid is applied uniformly after the image forming unit and the non-image forming unit, the post-processing liquid application amount (image forming unit) and the post-processing liquid application amount (non-image forming unit) are equal. . In the present invention, it is possible to make a difference in the amount of post-treatment liquid applied between the image forming unit and the non-image forming unit. For example, the post-processing liquid is applied only to the image forming unit and not applied to the non-image forming unit, the post-processing liquid is applied to both the image forming unit and the non-image forming unit. A configuration in which the density is changed is also possible. In such a case, the post-treatment liquid application amount (image forming unit) and the post-treatment liquid application amount (non-image forming unit) are different. The applied amount of the post-processing liquid (image forming unit) is the applied amount (volume) of the post-processing liquid per unit area of the image forming unit when the applied amount of ink per unit area of the image forming unit is 100%. The post-processing liquid application amount (non-image forming portion) is the post-processing per unit area of the non-image forming portion when the ink application amount per unit area of the image forming portion is 100%. Represents the amount of liquid applied (% by volume).

As an aspect of this invention, it is as follows, for example.
<1> a pretreatment liquid application step of applying a pretreatment liquid on a recording medium before image formation;
An image forming step of forming an image forming unit by applying ink on the recording medium to which the pretreatment liquid is applied;
A post-treatment liquid application step of applying a post-treatment liquid on the recording medium after image formation,
Glossiness of surface glossiness A at an incident angle of 60 degrees with respect to the image forming portion after application of the post-treatment liquid and surface glossiness B at an incident angle of 60 degrees with respect to non-image forming portions other than the image forming portion The image forming method is characterized in that the difference (A−B) is less than 15 °.
<2> Surface glossiness A ′ at an incident angle of 60 degrees with respect to the image forming portion before application of the post-treatment liquid, and surface glossiness B ′ at an incident angle of 60 degrees with respect to non-image forming portions other than the image forming portion The image forming method according to <1>, wherein the application amount of the post-processing liquid is controlled based on the difference in glossiness (A′−B ′).
<3> The image forming method according to any one of <1> to <2>, wherein the applied amount of the post-treatment liquid is 5% by volume to 30% by volume of the applied amount of the ink.
<4> The image forming method according to any one of <1> to <3>, wherein when the application amount of the pretreatment liquid is increased, the application amount of the posttreatment liquid is increased accordingly.
<5> The image forming method according to any one of <1> to <3>, wherein when the application amount of the pretreatment liquid is reduced, the application amount of the posttreatment liquid is reduced accordingly.
<6> The image forming method according to any one of <1> to <5>, wherein the application of the ink and the post-treatment liquid is performed by an inkjet method.
<7> The image forming method according to any one of <1> to <6>, wherein heat treatment is performed after application of the post-treatment liquid.
<8> Pretreatment liquid application means for applying a pretreatment liquid on the recording medium before image formation;
An image forming unit that forms an image forming unit by applying ink onto the recording medium to which the pretreatment liquid is applied;
A post-treatment liquid applying means for applying a post-treatment liquid on the recording medium after image formation,
Glossiness of surface glossiness A at an incident angle of 60 degrees with respect to the image forming portion after application of the post-treatment liquid and surface glossiness B at an incident angle of 60 degrees with respect to non-image forming portions other than the image forming portion The image forming apparatus is characterized in that the difference (A−B) is less than 15 °.
<9> Surface glossiness A ′ at an incident angle of 60 degrees with respect to the image forming portion before application of the post-treatment liquid, and surface glossiness B ′ at an incident angle of 60 degrees with respect to non-image forming portions other than the image forming portion The image forming apparatus according to <8>, wherein the application amount of the post-processing liquid is controlled based on a difference in glossiness (A′−B ′).

DESCRIPTION OF SYMBOLS 203 Recording medium 300 Inkjet recording device 301 Recording medium conveyance part 302 Pre-processing process part 303 Pre-processing post-drying part 304 Image formation process part 305 Post-processing process part 306 Post-processing post-drying part

JP 2004-330568 A Japanese Patent No. 40663338 JP 2005-022281 A

Claims (7)

A pretreatment liquid application step of applying a pretreatment liquid on the recording medium before image formation;
An image forming step of forming an image forming unit by applying ink on the recording medium to which the pretreatment liquid is applied;
A post-treatment liquid application step of applying a post-treatment liquid on the recording medium after image formation,
Glossiness of surface glossiness A at an incident angle of 60 degrees with respect to the image forming portion after application of the post-treatment liquid and surface glossiness B at an incident angle of 60 degrees with respect to non-image forming portions other than the image forming portion The image forming method, wherein the difference (A−B) is less than 15 °.   The image forming method according to claim 1, wherein the applied amount of the post-treatment liquid is 5% by volume to 30% by volume of the applied amount of the ink.   The image forming method according to claim 1, wherein when the amount of pretreatment liquid applied is increased, the amount of posttreatment liquid applied is increased accordingly.   3. The image forming method according to claim 1, wherein when the amount of pretreatment liquid applied is reduced, the amount of posttreatment liquid applied is reduced accordingly.   The image forming method according to claim 1, wherein the ink and the post-treatment liquid are applied by an ink jet method.   The image forming method according to claim 1, wherein heat treatment is performed after application of the post-treatment liquid. Pretreatment liquid application means for applying a pretreatment liquid on the recording medium before image formation;
An image forming unit that forms an image forming unit by applying ink onto the recording medium to which the pretreatment liquid is applied;
A post-treatment liquid applying means for applying a post-treatment liquid on the recording medium after image formation,
Glossiness of surface glossiness A at an incident angle of 60 degrees with respect to the image forming portion after application of the post-treatment liquid and surface glossiness B at an incident angle of 60 degrees with respect to non-image forming portions other than the image forming portion The image forming apparatus, wherein the difference (A−B) is less than 15 °.