JP2010069788A - Image recording method and inkjet recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image recording method and an inkjet recording apparatus performing preferable image recording without causing abnormality such as curl in a recording medium. <P>SOLUTION: When a kind of the recording medium 16 used in image recording is input, the prestored relationship between the kind of the recording medium and a coat layer thickness t is referred, and the thickness t of a coat layer 16A of the recording medium is determined. When the coat layer thickness t is determined, an application amount of a penetration suppressor for causing the curl of the recording medium to fall into a prescribed range is decided and the application of the penetration suppressor is performed. Thereafter, a treatment liquid for coagulating ink is applied and, further, ink drops are impacted to form a desired image on the recording medium 16. Because the application amount of the penetration suppressor is optimized in accordance with the coat layer thickness t, the curl of the recording medium 16 is suppressed and deterioration in fixation of the image due to excessive application of the penetration suppressor is also suppressed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image recording method and an ink jet recording apparatus, and more particularly to an image recording technique for suppressing curling occurring on a recording medium.

  In general, an ink jet recording apparatus includes an ink jet head in which a large number of nozzles are formed, and forms an image on a recording medium by ejecting ink droplets from the nozzles toward the recording medium. It is widely used because of its excellent performance, low running cost, and the ability to record high-quality images on a wide variety of recording media.

  When water-based ink is used for printing on “coated paper” such as art paper or coated paper, or “non-coated paper” such as high-quality paper using an inkjet recording device, the hydrogen bonds between the cellulose fibers of the paper are broken. There is a known problem that paper deformation called “curl” occurs due to recombination.

  Patent Documents 1 and 2 disclose a recording medium that is not easily curled by changing the characteristics of the recording medium itself. However, this method has a limitation in the selection range of the recording medium, which may be disadvantageous in terms of cost.

  Patent Document 3 discloses an ink jet recording method in which when an image with many high density portions is recorded, curling is reduced by reducing the duty of the high density portion and adjusting the amount of ink used for recording. ing.

  Patent Document 4 discloses a method of suppressing curling by applying alcohol to paper prior to ink recording, making the paper substantially dry at the recording position, and then recording an image. However, none of the methods can sufficiently suppress curling.

Furthermore, as another technique for suppressing curling, after applying a liquid (permeation inhibitor) having a function of suppressing ink permeation to the recording medium, image recording is performed by an ink jet method so that the ink permeates the recording medium. A technique for suppressing curling of the recording medium by suppressing the recording medium has been proposed.
JP-A-5-221115 JP 2003-80831 A JP 2002-67357 A JP 2004-136458 A

  However, when a permeation inhibitor is used, there is no problem in the curl suppression methods described in Patent Documents 1 to 4, but the fixing property of the image may be lowered by the application of the permeation inhibitor. In addition, even when the same amount of ink is used, the degree of curling varies depending on the type of recording medium. In particular, when a permeation inhibitor is uniformly applied to a recording medium where curling is unlikely to occur, image fixability due to the permeation inhibitor is applied. The problem of decline becomes more apparent.

  The present invention has been made in view of such circumstances, and an image recording method and an ink jet recording apparatus in which curling of a recording medium is effectively suppressed and a decrease in image fixability is prevented, and preferable image recording is performed. The purpose is to provide.

  In order to achieve the above object, an image recording method according to the present invention includes a specifying step of specifying a thickness of a coating layer of a recording medium used for image recording, and a curl of the recording medium within a predetermined range. The first treatment agent application that determines the application amount of the first treatment agent having the function of suppressing the penetration of the liquid into the recording medium according to the thickness of the coating layer of the recording medium specified by the specifying step An amount determination step, a first treatment agent application step of applying an amount of the first treatment agent determined by the first treatment agent application amount determination step to the recording medium, and a first treatment agent application step. An ink droplet ejection step of performing ink droplet ejection on the recording medium in accordance with input image data after the first processing agent is applied to the recording medium.

  According to the present invention, the application amount of the first treatment agent having a permeation suppressing effect according to the thickness of the coating layer of the recording medium so that the curling amount of the recording medium used for image recording falls within a predetermined range. Since the amount of the first processing agent appropriate for the recording medium is applied, curling of the recording medium is effectively suppressed, and the fixing property of the image due to excessive application of the first processing agent is reduced. Reduction is suppressed.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Description of image recording method]
1A to 1D schematically illustrate an image recording method according to an embodiment of the present invention. The image recording method shown in this example includes a determination step for determining the thickness (coat layer thickness t) of the coating layer 16A of the recording medium 16 shown in FIG. 1 (a), and a permeation inhibitor shown in FIG. 1 (b). The process includes an application process, a treatment liquid application process illustrated in FIG. 1C, and an ink ejection process illustrated in FIG. 1D.

  The determination step shown in FIG. 1A is a step for determining the coat layer thickness t of the recording medium 16. A recording medium 16 shown in FIG. 1A has a structure in which an image recording surface is coated with a coating layer 16A, and porous fine particles (for example, porous silica) are used as a coating material. Note that a recording medium using a polymer material as a coating material may be applied.

  As a method of determining the coat layer thickness t, the coat layer thickness t is stored in advance for each type of the recording medium 16 in a predetermined storage area (paper type data storage area in FIG. 2), and is automatically discriminated (or manually). A method of obtaining information on the type of the recording medium 16 by input) and determining the coating layer thickness t with reference to the paper type data storage area is applied. Note that the coating layer thickness t of the recording medium 16 may be directly detected by a predetermined detection element (detection means).

  In the permeation suppression agent applying step shown in FIG. 1 (b), a permeation suppression agent that suppresses the permeation of water and a hydrophilic organic solvent into the recording medium 16 (first treatment agent; 1). The amount of penetration inhibitor applied (permeation inhibitor amount) is determined so that the curl generated in the recording medium 16 falls within a predetermined range according to the coating layer thickness t determined in the determination step. The optimum amount is required so that the image fixability does not deteriorate due to overcoating.

  That is, in the image recording method shown in this example, the coating layer thickness t was found as a parameter for obtaining the optimum amount of the penetration inhibitor from the two viewpoints of curling and image fixing performance. In other words, based on the coating layer thickness t, the amount of the permeation inhibitor that causes the curl to fall within a predetermined range is obtained, and the problem of a decrease in image fixability due to excessive application of the permeation inhibitor by applying the optimum amount of the permeation inhibitor simultaneously Settled. In addition, the detail about the determination method of the penetration inhibitor amount is mentioned later.

  As the permeation inhibitor, a solution in which latex is dispersed in an organic solvent, a solution in which a polymer is dissolved in an organic solvent, wax, or the like is preferably used. As the organic solvent, non-aqueous solvents such as methyl ethyl ketone and petroleum (the solvent itself does not cause paper curl) are preferably used. Even if the solvent is a solvent that generates curl such as water, the amount of the first treatment agent applied can be optimized, so that it can be used.

  As a method for applying the permeation suppressant, droplet ejection by an ink jet method (a mode in which the permeation inhibitor is atomized from the nozzle 51 and ejected is shown in FIG. 1B), spray coating, roller coating, bar coating Etc. are preferably used. In the case of applying the ink jet method, it is preferable that the permeation suppressor can be selectively applied only to the ink droplet-filled portion and the periphery thereof described later.

  Since the permeation inhibitor shown in this example contains fine particles that are formed into a film by heating, the solvent component of the permeation inhibitor is evaporated by applying heat treatment after the permeation inhibitor is applied, and the resin component By forming a film (latex, dissolved polymer, etc.), a more preferable permeation suppression layer is formed.

  In the treatment liquid application step shown in FIG. 1 (c), after the penetration inhibitor layer 1A is formed on the surface of the recording medium 16 by the penetration inhibitor application step, an ink containing a coloring material (described later in FIG. 1 (d)). 3) The substance having a component for aggregating or thickening the coloring material (pigment or dye) in the above (processing liquid, second processing agent; FIG. 1 (c) shows the processing liquid 2 formed into fine droplets) Is granted.

  Specific examples of the treatment liquid include a treatment liquid that reacts with the ink to precipitate or insolubilize the color material in the ink, and a treatment liquid that generates a semi-solid substance (gel) containing the color material in the ink. . As a method for causing a reaction between the ink and the treatment liquid, a method in which an anionic coloring material in the ink and a cationic compound in the treatment liquid are reacted, or an ink having a different pH and a treatment liquid are mixed with each other. A method of causing pigment dispersion in the ink to cause dispersion destruction by changing the pH of the ink, and a method of causing dispersion dispersion of the pigment in the ink by reaction with a polyvalent metal salt contained in the treatment liquid to cause the pigment to agglomerate Etc.

  As the method of applying the treatment liquid, as in the case of the method of applying the permeation inhibitor, droplet ejection by an ink jet method (a mode in which the treatment liquid is atomized and ejected from the nozzle 51 'is shown in FIG. 1 (c)), spray Application, roller application, bar application and the like are preferably used. In the case of applying the ink jet method, it is preferable that the treatment liquid can be selectively applied only to the ink droplet-filled portion described later and the periphery thereof.

  As described above, since the treatment liquid is applied to the place where the penetration inhibitor is previously applied (on the penetration inhibitor layer 1A), the penetration of the treatment liquid into the recording medium 16 is suppressed. In order to prevent the coloring material component in the ink described later from aggregating and not adhering to the recording medium 16 (penetration inhibitor layer 1A) and floating in the processing liquid layer 2A, a processing liquid is applied. After the treatment (after the treatment liquid layer 2A is formed), it is preferable to dry (evaporate) the solvent in the treatment liquid.

  In FIG. 1 (d), in the ink droplet ejection step, the ink droplet 3 is ejected from the nozzle 51 ″ in order to form the dot 3A corresponding to the input image by the ink jet method. A desired image is recorded on the recording medium 16 by ejecting ink droplets in accordance with image data on the area where the image is formed.

  According to the above-described image recording method, since the application amount of the permeation inhibitor is controlled (optimized) according to the coating layer thickness t of the recording medium 16, deterioration of image fixability due to excessive application of the permeation inhibitor is suppressed. The Further, the penetration inhibitor functions to prevent the solvent component of the treatment liquid 2 and the ink droplet 3 from penetrating into the recording medium 16, and curling in the recording medium after image recording is suppressed. Further, since the treatment liquid 2 is held on the surface of the recording medium 16 without penetrating the recording medium 16, the ink droplet 3 that has landed on the recording medium 16 (the treatment liquid layer 2 </ b> A) is quickly fixed on the surface of the recording medium 16. In addition, the occurrence of image abnormality such as ink bleeding is prevented.

[Description of judgment process]
Next, the determination process illustrated in FIG. 1A will be described in more detail.

  FIG. 2 is a flowchart showing the control flow of the determination process. As shown in the figure, first, the type of the recording medium 16 is set (step S10). The method of setting the type of the recording medium 16 is such that an information storage body such as an IC tag storing information of the type of the recording medium 16 is attached to a cassette or the like in which the recording medium 16 is stored, and the information storage body is automatically Or may be set directly by the user via the user interface. Alternatively, the recording medium 16 may be read by an image pickup device such as a CCD provided on the conveyance path of the recording medium 16 and the type of the recording medium 16 may be determined from the read result.

  When the type of the recording medium 16 is determined in step S10, the type (paper type) of the recording medium 16 stored in the paper type data storage area (partial area in the database storage unit indicated by reference numeral 94 in FIG. 14). ) Is referred to (step S12).

  Note that the value of the coat layer thickness t may be directly input, or the coat layer thickness t may be directly detected. Specific examples of directly inputting the coating layer thickness t include a method of inputting from a console or PC for controlling the apparatus, and a method of inputting from an input device (user interface) integrated with the apparatus.

  Further, as a method for directly detecting the coating layer thickness t, there is a method in which a detection element is brought into contact with a recording medium. Specifically, a method for determining the thickness of the coat layer by piercing the recording medium with a detection element having a needle shape at the tip and determining the boundary between the coat layer and the base paper layer where the resistance greatly changes in the middle is considered. .

  Thereafter, in step S14, it is determined whether or not the input recording medium 16 has paper type data (coat layer data). If the paper type data exists, the recording medium 16 depends on the coat layer thickness t. The permeation inhibitor amount is set (step S16), and the permeation inhibitor amount is stored in the permeation inhibitor amount storage area (indicated by reference numeral 96 in FIG. 14) (step S18), according to the permeation inhibitor set amount. A permeation inhibitor is applied (step S20).

  On the other hand, if it is determined in step S14 that the paper type data does not exist (No determination), a default penetration inhibitor amount is set (step S22), and the default penetration inhibitor amount is the penetration inhibitor. It is stored in the amount storage area (step S18), and the permeation inhibitor is applied according to the set amount of the permeation inhibitor (step S20).

  In addition, when there is no paper type data, it is preferable that the configuration is configured to notify the user to that effect. In addition, it is preferable that the user can set a default penetration inhibitor amount when it is notified that the paper type data does not exist.

  FIG. 3 schematically shows an example of a data table (relationship between the coating layer thickness t and the penetration inhibitor amount) for determining the penetration inhibitor amount in a graph format. Such a data table is prepared in advance and stored in a predetermined storage area (database storage unit 94 in FIG. 14), and the permeation inhibitor amount can be obtained by referring to the database.

  Since a recording medium having a large coat layer thickness t can hold more ink in the coat layer, curling is unlikely to occur, and the amount of permeation inhibitor applied can be reduced.

  On the other hand, since a recording medium having a small coat layer thickness t has a small amount of ink that can be held in the coat layer, a larger amount of penetration inhibitor is required to suppress curling. The relationship between the coating layer thickness t and the penetration inhibitor amount y shown in FIG. 3 can be obtained by experiments and simulations shown below.

  In the method for determining the permeation inhibitor amount y shown in this example, even if the conditions other than the coat layer thickness t such as the material and thickness of the substrate are the same, those having different coat layer thickness t are treated as different types. It is.

  Here, the default amount of penetration inhibitor in step S22 of FIG. 2 will be described. The default amount of penetration inhibitor can be any value on the straight line shown in FIG. 3A, and can be determined by the grade of the recording medium as follows. The default permeation suppressor amount shown below is merely an example, and can be changed as appropriate.

  When the grade of the recording medium (paper) is known, the thickness of the coat layer in FIG. 3A is set according to the grade, and the amount of penetration inhibitor corresponding to the thickness is set as the default amount of penetration inhibitor.

  In the case of “A2 mat or lower grade” (A2 mat, recycled paper), the code layer thickness t for A2 mat is 7.156 μm, and the coat layer thickness t for recycled paper is 5.125 μm. The coat layer thickness t is an average value obtained by actually measuring the coat layer thickness t for several recording media corresponding to each grade.

  Further, in the case of “grades other than A2 mat or less” (paperboard, art post, A1 gloss, A1 mat, A2 gloss), the average coat layer thickness t is 8.1 μm, which is higher than the grade of A2 mat or less. Since it is relatively thick, the possibility of curling is very low without applying an inhibitor, so no penetration inhibitor is applied. That is, the default amount of penetration inhibitor is zero.

  When the grade of the recording medium is not known, since the average coat layer thickness t (excluding paperboard) of each grade is about 10 μm, no penetration inhibitor is applied as in “grades other than A2 mat or less”. FIG. 3B shows data obtained by actually measuring the coating layer thicknesses of several recording media.

[Description of data table creation]
Next, a method for producing a data table showing the relationship between the coating layer thickness t and the amount of penetration inhibitor will be described.

  In this experiment, nine types of recording media (sheets 1 to 9) having different coat layer thicknesses t were used, and the conditions for applying the permeation suppressant were “no permeation suppressor”, “small amount condition”, and “large amount condition”. Instead of applying the permeation inhibitor using the application bar, the treatment liquid was applied using the application bar, and the curling amount | C | was measured after drying at room temperature for 1 day.

  Among the sheets 1 to 9, the sheet 1 and the sheet 2 are the same and have different weighing (the weighing of the sheet 2 is larger than that of the sheet 1). Similarly, the paper 3 and the paper 4 and the paper 5 and the paper 6 are the same and have different weighing (the weighing of the paper 4 is larger than that of the paper 3 and the weighing of the paper 6 is larger than that of the paper 5).

  Liquid application using an application bar is a simple application method, but the applied amount can be changed quantitatively by changing the pitch width or groove depth carved in the bar.

  The “curl amount | C |” here is C = 10 / R (cm) assuming that the sample cut to 5 mm × 50 mm in the curl direction is applied to the measurement plate and the curl is regarded as an arc of a circle of radius R. It is a time value. The unit of curl amount is 10 / cm.

  Further, the “curl value C” to be described later is oriented with the minus when the drawing surface side extends (tilts toward the non-drawing surface side) and the plus when the drawing surface side extends toward the opposite side. In this measurement method, since there is no influence of gravity, the curl value C is proportional to the amount of distortion, and the curl in the width direction can be measured, so that it can be separated from the cause of curling.

Moreover, the prescription of the permeation inhibitor A and the treatment liquid used in this experiment is as shown below. In addition, although the penetration inhibitor A was used in this experiment, even if the penetration inhibitor B is used, the same result can be obtained.
(Penetration inhibitor A)
The permeation inhibitor A was prepared according to the following formulation.

  A mixed solution of 10 g of the dispersion stabilizer [Q-1] having the structure shown in the following [Chemical Formula 1], 100 g of vinyl acetate and 384 g of Isopar H (trade name, manufactured by Exxon) was heated to a temperature of 70 ° C. while stirring in a nitrogen stream. .

  As a polymerization initiator, 0.8 g of 2,2-azobis (isovaleronitrile; abbreviation AIVN) was added and reacted for 3 hours. 20 minutes after adding the polymerization initiator, white turbidity occurred, and the reaction temperature rose to 88 ° C.

  Further, 0.5 g of the polymerization initiator was added and reacted for 2 hours, and then the temperature was raised to 100 ° C. and stirred for 2 hours to distill off unreacted vinyl acetate. After cooling, it is passed through a 200-mesh nylon cloth, and the resulting white dispersion is a latex with a good monodispersity having a polymerization rate of 90% and an average particle size of 0.23 μm. The particle size of the latex was measured with a particle size measuring device CAPA-500 (manufactured by Horiba Seisakusho).

A part of the white dispersion (latex) is subjected to a centrifuge (rotation speed: 1 × 10 ⁴ rpm, rotation time: 60 minutes), and the precipitated resin particles are collected and dried. the weight average molecular weight of min (Mw) and glass transition temperature _(T g), was measured minimum film-forming temperature (MFT). Mw = 2 × 10 ⁵ (GPC value in terms of polyethylene), T _g = 38 ° C., and MFT = 28 ° C.

(Penetration inhibitor B)
The permeation inhibitor B was prepared according to the formulation shown below.

  A mixed solution of 15 g of dispersion stabilizer [Q-2] having the structure shown in the following [Chemical Formula 2], 75 g of benzine methacrylate, 25 g of methyl acrylate, 1.3 g of methyl 3-mercaptopropionate and 552 g of Isopar H (trade name, manufactured by Exxon). Was heated to 50 ° C. with stirring under a nitrogen stream.

  As a polymerization initiator, 2,2 azobis (2-cyclopropylpropionitrile; abbreviation ACPP) 1.0 g was added and reacted for 2 hours. Furthermore, A.I. C. P. P. 1. 0.8 g of the reaction mixture was reacted for 2 hours. I. V. N. Was added, and the reaction temperature was set to 75 ° C. and reacted for 3 hours.

  Next, the mixture was heated to 90 ° C., the unreacted monomer was distilled off under a reduced pressure of 20 to 30 mmHg, cooled, and passed through a 200 mesh nylon cloth. The resulting white dispersion had a polymerization rate of 98. % And an average particle size of 0.20 μm is a latex having good monodispersibility. The particle size of the latex was measured with a particle size measuring device CAPA-500 (manufactured by Horiba Seisakusho).

The weight average molecular weight (Mw) of the resin particles is 2 × 10 ⁴ (polyethylene equivalent GPC value),
In this experiment, since the concentration of the permeation inhibitor is 10 weight percent, the dissolved mass of the permeation inhibitor is 10% of the solution amount. The method for preparing the penetration inhibitor will be described in an apparatus configuration example described later.

(Processing liquid)
Citric acid (manufactured by Wako Pure Chemical Industries): 15 parts by mass Orphine E1010 (manufactured by Nissin Kagaku): 1% by mass
Ion-exchanged water: balance FIG. 4 shows the experimental results in a list form. In the experimental results shown in the figure, the criterion for evaluation when a preferable curl suppressing effect is obtained is indicated by an evaluation ◯ with | C | ≦ 1, and the criterion for the case where slight curl is generated but does not cause a problem is 1 <| C. It is indicated by an evaluation Δ where | ≦ 2. When the curl amount is a big problem (when the curl suppression effect cannot be obtained), the evaluation standard is represented by | C |> 2.

As in this experiment, when a coating bar is used, the amount of penetration inhibitor (g / m ² ) is recorded even if the coating conditions are the same (even if a bar having the same groove shape is used). It depends on the physical properties (penetration, wettability) of the medium. In FIG. 4, the amount of the penetration inhibitor under the “small amount” condition is 1.39 g / m ^{2 to} 3.0 g / m ² , and the amount of the penetration inhibitor under the “large amount” condition is 2.78 g / m ^{2 to} 5.65 g / m ^2. It has become.

(Evaluation under all conditions ○)
When paper 1 (t ≈ 9.6 μm) and paper 2 (t ≈ 12.1 μm) are used, the evaluation is ○ under all conditions of “no penetration inhibitor”, “small amount”, and “large amount”. Yes.
(Evaluation without penetration inhibitor, evaluation with small amount, evaluation with large amount)
The paper 3 (t≈7.1 μm), the paper 4 (t≈8.1 μm), and the paper 8 (t = 7.5 μm) have an evaluation Δ in the case of “no penetration inhibitor”, but “small amount”. In the case of “large amount”, the evaluation is ○.

(No penetration inhibitor, small amount evaluated △, large amount evaluated ○)
The paper 6 (t = 5.5 μm) is evaluated as “Good” when “No penetration inhibitor” and “Small amount”, but becomes “Good” when “Large amount”.

(Evaluation × without penetration inhibitor, evaluation △ for small amounts and large amounts)
The paper 5 (t = 5.1 μm) is evaluated as “poor” in the case of “no penetration inhibitor”, but is evaluated as Δ in the case of “small amount” and “large amount”.

(No penetration inhibitor, evaluation x for small amounts, evaluation △ for large amounts)
Paper 7 (t = 4.5 μm) and paper 9 (t = 4.0 μm) are evaluated as “poor” when “no penetration inhibitor” or “small amount”, but evaluated when “large amount”. It becomes.

In this experiment, since the application bar was also used for application of the treatment liquid, application was performed on the same conditions for all the recording media. However, for the reasons described above, the application amount of the treatment liquid differs depending on the recording medium. However, as shown in FIG. 5, even when the amount of treatment liquid applied is relatively changed by about 2 (g / m ² ), the paper 5 has almost the same curl amount. It has been confirmed not to. Further, the treatment liquid application amount can be considered in the same manner for other sheets.

  FIG. 6 is a graph showing the relationship between the coating layer thickness t and the amount of penetration inhibitor from the table shown in FIG. In FIG. 6, the ▲ plot shows no penetration inhibitor, the ◆ plot shows a small amount, and the ■ plot shows a large amount. In addition, the solid line illustrated in FIG. 6 is a boundary line between evaluation ◯ and evaluation Δ, and the broken line is a boundary line between evaluation △ and evaluation ×.

  From the graph shown in FIG. 6, the boundary line of evaluation (circle) and evaluation (triangle | delta) can be represented by following Formula (1) by making the penetration inhibitor amount into y.

y = −3 × t + 21.9 (1)
The boundary line between evaluation Δ and evaluation × can be expressed by the following equation (2).

y = −3 × t + 15.9 (2)
As described above, by storing the above formulas (1) and (2) in a database, the penetration inhibitor amount y is set according to the coat layer thickness t. For example, when the curl value C is | C | ≦ 1, the data table based on the above (1) is referred to, and when the curl value C is | C | ≦ 2, the above is based on (2). The permeation inhibitor amount y can be set with reference to the data table. In addition, you may obtain | require the penetration inhibitor amount y by a calculation using said (1) and (2).

  FIG. 7 illustrates the relationship between the coat layer thickness t and the curl value C in a graph format.

  A straight line denoted by reference numeral 100 in FIG. 7 is a case of “no penetration inhibitor”, and is represented by the following expression (3).

C = 0.3206 × d−3.7259 (3)
The straight line denoted by reference numeral 102 is the case of “small amount”, and the straight line denoted by reference numeral 104 is the case of “large amount”. They are represented by the following expressions (4) and (5), respectively.

C = 0.3109 × d−3.3178 (4)
C = 0.1862 × d−1.9815 (5)
As shown in FIG. 7, since the coat layer thickness t and the curl value C show a proportional relationship, the larger the coat layer thickness t, the greater the amount of solvent (liquid amount) that can be stored in the coat layer. It becomes difficult to wet the (base material), and curling is suppressed.

  According to the image recording method configured as described above, when the curling of the recording medium is suppressed by the penetration inhibitor, the amount of the penetration inhibitor applied is set to an optimum value according to the thickness of the coating layer of the recording medium used. Therefore, a decrease in image fixability due to excessive application of the penetration inhibitor is suppressed, and curling of the recording medium is suppressed.

  Further, for a recording medium having a relatively large coating layer thickness that is difficult to curl, it is not necessary to add an extra penetration inhibitor. Furthermore, application to a special recording medium is also possible by using the coating layer thickness as a parameter.

  In this example, the mode of storing the relationship between the coating layer thickness and the penetration inhibitor application amount in advance as a database is illustrated, but the penetration inhibitor application amount is obtained by calculation using the above formulas (1) and (2). May be.

〔Device configuration〕
Next, an image recording apparatus (inkjet recording apparatus) to which the image recording method shown in FIGS. 1A to 1C is applied will be described.

(overall structure)
FIG. 8 is an overall configuration diagram of the ink jet recording apparatus 10 shown in this example.

  As shown in FIG. 8, the ink jet recording apparatus 10 is transported in a predetermined recording medium transport direction S by the recording medium transport unit 14 from the ink droplet ejection unit 12 including the heads 12C, 12M, 12Y, and 12K corresponding to CMYK colors. The on-demand image forming apparatus records a desired color image by ejecting ink of CMYK colors onto the recording medium 16 to be recorded.

  The ink jet recording apparatus 10 includes a permeation suppression agent applying unit 18 that applies a permeation suppressor (see FIG. 1A) to the recording medium 16, a heater 19 that heats the recording medium 16 when the permeation suppression agent is applied, and a permeation suppression. Permeation inhibitor drying unit 20 for drying the solvent in the agent, and treatment liquid application unit for applying the treatment liquid to the resin film subjected to the drying treatment (permeation inhibitor film; see FIGS. 1A and 1B) 22, a treatment liquid drying unit 24 that dries the solvent in the treatment liquid, the ink droplet ejection unit 12 described above, an ink drying unit 26 that dries the solvent in the ink on the recording medium 16, and an ink coloring material. And a fixing pressure unit 28 that performs a process of fixing to the medium 16.

  The recording medium 16 held by the recording medium transport unit 14 is transported from left to right in FIG. 8, and first, a permeation inhibitor is applied from the permeation suppressor application unit 18. In this example, a heater 19 is incorporated immediately below the permeation suppression agent applying unit 18 of the recording medium transport unit 14, and the recording medium 16 is subjected to heat treatment immediately before application of the permeation suppression agent, during application of the permeation suppression agent, and immediately after application of the permeation suppression agent. And a resin film (permeation suppression film) is formed on the image forming surface of the recording medium 16 by the resin in the permeation suppression agent.

  Further, a temperature sensor 31 for detecting the temperature of the recording medium 16 (the temperature of the image forming surface of the recording medium 16) is provided in the heating area of the heater 19, and based on the detection result of the temperature sensor 31, the recording medium 16 is heated. The heater 19 is controlled so that the temperature is within a certain range. As the temperature sensor 31, a non-contact temperature sensor is preferably used.

  An infrared heater is preferably used as the heater 19. The arrangement of the heater 19 is not limited to the arrangement shown in FIG. 3, and a resin film may be formed by the resin in the penetration inhibitor applied to the recording medium 16 before the treatment liquid is ejected. It may be arranged upstream of the inhibitor applying unit 18 in the recording medium conveyance direction, or may be arranged downstream of the permeation suppression agent applying unit 18 in the recording medium conveyance direction. Further, it may be arranged over a wide range from the upstream side to the downstream side in the recording medium conveyance direction.

  In this example, the aspect in which the heater 19 is built in the recording medium transport unit 14 is illustrated, but the heater 19 may be disposed so as to face the image forming surface of the recording medium 16. Further, instead of the heater 19, the recording medium 16 may be heated by a method of blowing dry air or hot air to the recording medium 16, or the heater 19 and heating by air blowing may be used in combination.

  Thereafter, a permeation inhibitor drying process is performed by a permeation inhibitor drying unit 20 provided on the downstream side of the permeation inhibitor applying unit 18 in the recording medium conveyance direction.

  After the permeation suppression agent drying process, a processing liquid is applied from a processing liquid application unit 22 provided on the downstream side of the permeation suppression agent drying unit 20 in the recording medium conveyance direction, and further, the processing liquid application unit 22 is downstream in the recording medium conveyance direction. The treatment liquid is dried by the treatment liquid drying unit 24 provided on the side. The treatment liquid that has been subjected to the drying treatment becomes a solid treatment liquid layer (see FIG. 1C).

  When the resin film and the treatment liquid layer are formed on the recording medium 16, ink droplets are ejected according to the image data from the ink ejection unit 12 provided on the downstream side of the treatment liquid drying unit 24 in the recording medium conveyance direction, Ink drying processing is performed by the ink drying unit 26 provided on the downstream side of the ink droplet ejection unit 12 in the recording medium conveyance direction.

  The recording medium conveyance unit 14 holds the recording medium 16 on the surface of an endless belt wound around a plurality of rollers, conveys the recording medium 16, holds the recording medium 16 on the outer peripheral surface of the drum, A method such as drum conveyance in which the recording medium 16 is conveyed on the outer peripheral surface of the drum by rotating in a predetermined rotation direction is preferably used. In addition, as a method of holding the recording medium 16 in the recording medium transport unit 14, various methods such as air adsorption by air suction, electrostatic adsorption by static electricity, and a method of holding the end portion of the paper in a nip can be applied. it can.

  An ink jet method (ink jet head) is suitably used for the permeation suppression agent applying unit 18 and the treatment liquid applying unit 22 of this example. Of course, instead of the ink jet method, a method such as a coating method using a coating member such as a coating bar or a coating roller or a spray method may be applied.

  A common configuration is applied to each drying unit in this example. That is, in each drying section shown in this example, a drying process is performed from above the medium (from the image forming surface side of the recording medium 16). The drying treatment is preferably a combination of infrared drying and drying air. Further, solvent absorption by a porous roller may be performed instead of or in combination with drying of the solvent in the ink. Further, it is possible to apply a mode in which a heater is incorporated in a structure (for example, inside a belt or a drum) that holds the recording medium 16.

  Since the ink droplet ejection amount is greater than the droplet ejection amount of the permeation inhibitor and the treatment liquid droplet ejection amount, the ink drying unit 26 provided in the subsequent stage of the ink droplet ejection unit 12 has a larger capacity than the other drying processing units. An embodiment is preferable in which the size is set to be large and dried strongly.

In the fixing pressure unit 28 provided on the downstream side of the ink drying unit 26 in the recording medium conveyance direction, a pressure of about 0.5 to 2.0 MPa and about T ₂ (= 70 to 100 ° C.) are applied to the color material aggregate. It is preferable that the dispersion polymer (resin component) in the ink is melted to enhance the adhesion with the recording medium 16 (resin film 1A shown in FIGS. 1A and 1B). That is, a pressing roller with a built-in heater (not shown) is preferably used for the fixing pressure unit 28. It is also possible to incorporate the heater portion in the recording medium transport unit 14.

  A sensor 30 is provided in the recording medium conveyance direction of the fixing pressure unit 28. The sensor 30 includes an image sensor (CCD) that captures an image recorded on the recording medium 16. In the ink jet recording apparatus 10 of this example, the presence or absence of an abnormality (ink ejection abnormality) is determined for each color of the ink ejection unit 12 based on the imaging result of the sensor 30.

  The sensor 30 is configured to be able to read a color image. For example, a filter corresponding to each color of RGB may include a sensor corresponding to each color of RGB, or a configuration including color filters corresponding to each color of RGB arranged in a predetermined arrangement. In addition, a line sensor in which the image sensors are arranged in a line may be used, or an area sensor in which the image sensors are arranged in a two-dimensional manner may be used.

  Although not shown, the ink jet recording apparatus 10 is provided with a paper feed unit that supplies the recording medium 16 to the recording medium transport unit 14. When it is configured to be able to use a plurality of types of paper (recording media) (when there are a plurality of magazines in which the recording media 16 are accommodated), each information recording body such as a barcode or a wireless tag that records paper type information is provided. It is attached to a magazine and the information on the information recording medium is read by a predetermined reading device to automatically determine the type of recording medium to be used (media type), and appropriate ink ejection and processing liquid according to the media type It is preferable to perform ink ejection control, treatment liquid application control, and permeation inhibitor application control so as to realize application and application of the permeation inhibitor.

  In addition, when using a long continuous paper wound in a roll shape, a cutter that cuts the recording medium 16 to a predetermined length is provided in front of the permeation suppression agent applying unit 18. A configuration example of a cutter for cutting includes a fixed blade having a length equal to or greater than the width of the recording medium 16, and a round blade that moves along the fixed blade, and a fixed blade is provided on the back side of the print, The structure by which a round blade is arrange | positioned on the printing surface side across the conveyance path of the recording medium 16 is mentioned.

  Although not shown, the ink jet recording apparatus 10 includes an ink storage / loading unit that supplies ink to the heads 12C, 12M, 12Y, and 12K of the ink droplet ejection unit 12. The ink storage / loading unit has an ink supply tank (indicated by reference numeral 60 in FIG. 13) that stores ink of the colors corresponding to the heads 12C, 12M, 12Y, and 12K. Are communicated with the heads 12C, 12M, 12Y, and 12K. In addition, the ink storage / loading unit includes notifying means (display means, warning sound generating means) for notifying when the ink remaining amount is low, and a member having a mechanism for preventing erroneous loading between colors. Used.

  Similar to the above-described ink storage / loading unit, it has a configuration for supplying the permeation suppression agent to the permeation suppression agent applying unit 18 and a configuration for supplying the processing liquid to the processing liquid application unit 22. Yes. In addition to the configuration described above, the ink jet recording apparatus 10 shown in this example detects a position of the recording medium 16 on the paper conveyance path, a cleaning processing unit that removes dirt on the surface of the recording medium conveyance unit 14 that holds the paper. A position detecting sensor for detecting the temperature of each part of the apparatus such as the periphery of the ink droplet ejecting part 12, a paper discharge part for discharging the recording medium 16 after image recording to the outside of the apparatus, A moving mechanism for moving between the retreat positions is provided.

(Description of printing section)
Next, the ink ejection unit 12 will be described in detail. As shown in FIG. 9, each head 12C, 12M, 12Y, 12K of the ink droplet ejection unit 12 has a length corresponding to the maximum width of the image recording area in the recording medium 16, and an image is formed on the ink ejection surface thereof. This is a full-line head in which a plurality of nozzles for ink ejection (shown by reference numeral 51 in FIG. 10) are arranged over the entire width of the recording area.

  The heads 12C, 12M, 12Y, and 12K are arranged from the upstream side along the transport direction (sub-scanning direction; indicated by reference numeral A) of the recording medium 16 from the upstream side to cyan (C), magenta (M), yellow (Y), and black (K ) Are arranged in the order of colors, and the heads 12C, 12M, 12Y, and 12K are fixedly installed so as to extend in a direction (main scanning direction) orthogonal to the paper transport direction.

  According to the configuration in which the full-line type heads having the nozzle rows covering the entire width of the recording medium 16 are provided for the respective color inks, the heads 12C and 12M of the recording medium 16 and the ink droplet ejecting unit 12 in the paper transport direction. , 12Y, and 12K can be formed in the image recording area of the recording medium 16 only by performing the operation of relatively moving the images, 12Y, and 12K once (that is, by one sub-scan). Accordingly, the heads 12C, 12M, 12Y, and 12K can perform high-speed printing as compared with a serial (shuttle) type head that reciprocates in the main scanning direction orthogonal to the paper transport direction, and can improve print productivity. .

  In this example, the configuration of CMYK standard colors (four colors) is illustrated, but the combination of ink colors and the number of colors is not limited to this embodiment, and light ink, dark ink, and special color ink are used as necessary. May be added. For example, it is possible to add an ink head that discharges light-colored ink such as light cyan and light magenta, and the arrangement order of the color heads is not particularly limited.

(Head structure)
Next, the structure of the heads 12C, 12M, 12Y, and 12K will be described in detail. Since the structures of the heads 12C, 12M, 12Y, and 12K are common, the head is represented by the reference numeral 50 as a representative of them. Since the same configuration as the head 50 can be applied to the ink jet head (processing liquid head) included in the treatment liquid application unit 22, the head 12 </ b> C, the ink jet head included in the ink jet recording apparatus 10 of this example is used. A description will be given using 12M, 12Y, and 12K.

  FIG. 10A is a plan perspective view showing an example of the structure of the head 50, and FIG. 10B is an enlarged view of a part thereof. 10C is a plan perspective view showing another example of the structure of the head 50, and FIG. 11 is a cross-sectional view showing the three-dimensional configuration of the ink chamber unit (AA in FIGS. 10A and 10B). It is sectional drawing which follows a line.

  In order to increase the dot pitch formed on the recording medium 16, it is necessary to increase the nozzle pitch in the head 50. As shown in FIGS. 10A and 10B, the head 50 of this example includes a plurality of ink chamber units 53 including nozzles 51 that are ink droplet ejection holes and pressure chambers 52 corresponding to the nozzles 51. The nozzles are arranged in a staggered matrix (two-dimensionally), so that a substantial nozzle interval (projection nozzle pitch) projected so as to be aligned in the longitudinal direction of the head (sub-scanning direction) High density is achieved.

  The form in which one or more nozzle rows are configured in the main scanning direction over a length corresponding to the entire width of the recording medium 16 is not limited to this example. For example, instead of the configuration of FIG. 10A, as shown in FIG. 10C, short head modules 50 ′ in which a plurality of nozzles 51 are two-dimensionally arranged are arranged in a staggered manner and connected. A line head having a nozzle row having a length corresponding to the entire width of the recording medium 16 may be configured. Although not shown, a line head may be configured by arranging short head modules in a line.

  The pressure chamber 52 provided corresponding to each nozzle 51 has a substantially square planar shape, and the nozzle 51 and the supply port 54 are provided at both corners on the diagonal line. As shown in FIG. 11, each pressure chamber 52 communicates with a common channel 55 through a supply port 54. The common channel 55 communicates with an ink supply tank (not shown in FIG. 11, not shown in FIG. 13 and indicated by reference numeral 60) as an ink supply source, and the ink supplied from the ink supply tank is the common channel 55 shown in FIG. Is distributed and supplied to each pressure chamber 52.

  A piezoelectric element 58 having an individual electrode 57 is joined to a diaphragm 56 that constitutes the top surface of the pressure chamber 52 and also serves as a common electrode. By applying a driving voltage to the individual electrode 57, the piezoelectric element 58 is Deformation causes ink to be ejected from the nozzle 51. When ink is ejected, new ink is supplied from the common channel 55 to the pressure chamber 52 through the supply port 54.

  As shown in FIG. 12, the ink chamber unit 53 having such a structure is latticed in a fixed arrangement pattern along a row direction along the main scanning direction and an oblique column direction having a constant angle θ not orthogonal to the main scanning direction. The high-density nozzle head of this example is realized by arranging a large number in the shape.

  That is, with a structure in which a plurality of ink chamber units 53 are arranged at a constant pitch d along the direction of an angle θ with respect to the main scanning direction, the pitch P of the nozzles projected in the main scanning direction is d × cos θ. Thus, in the main scanning direction, each nozzle 51 can be handled equivalently as a linear arrangement with a constant pitch P. With such a configuration, it is possible to realize a high-density nozzle configuration in which 2400 nozzle rows are projected per inch (2400 nozzles / inch) so as to be aligned in the main scanning direction.

  When the nozzles are driven by a full line head having a nozzle row having a length corresponding to the entire printable width, (1) all the nozzles are driven simultaneously, (2) the nozzles are sequentially moved from one side to the other. (3) The nozzle is divided into blocks, each block is sequentially driven from one side to the other, and the like in the width direction of the recording medium 16 (direction perpendicular to the conveyance direction of the recording medium 16). The driving of the nozzle that prints one line (one line of dots or a line of dots of a plurality of lines) is defined as main scanning.

  In particular, when driving the nozzles 51 arranged in a matrix as shown in FIGS. 10A and 10B, the main scanning as described in the above (3) is preferable. That is, nozzles 51-11, 51-12, 51-13, 51-14, 51-15, 51-16 are made into one block (other nozzles 51-21,..., 51-26 are made into one block, The nozzles 51-31,..., 51-36 as one block,...), And the nozzles 51-11, 51-12,. One line is printed in 16 width directions.

  On the other hand, by moving the full line head and the recording medium 16 relative to each other, printing of one line (a line formed by one line of dots or a line made up of a plurality of lines) formed by the main scanning described above is repeatedly performed. This is defined as sub-scanning.

  The direction indicated by one line (or the longitudinal direction of the belt-like region) recorded by the main scanning is referred to as a main scanning direction, and the direction in which the sub scanning is performed is referred to as a sub scanning direction. That is, in the present embodiment, the conveyance direction of the recording medium 16 is the sub-scanning direction, and the width direction of the recording medium 16 orthogonal to the recording medium 16 is the main scanning direction. In the implementation of the present invention, the nozzle arrangement structure is not limited to the illustrated example.

  In this embodiment, a method of ejecting ink droplets by deformation of the piezoelectric element 58 typified by a piezo element (piezoelectric element) is employed. However, in the practice of the present invention, the method of ejecting ink is particularly limited. Instead of the piezo jet method, various methods such as a thermal jet method in which ink is heated by a heating element such as a heater to generate bubbles and ink droplets are ejected by the pressure can be applied.

  The scope of application of the present invention is not limited to a printing method using a line-type head, and a short head that is less than the length in the width direction of the recording medium 16 is scanned in the width direction of the recording medium 16 to perform printing in the width direction. When printing in the width direction is completed once, the recording medium 16 is moved by a predetermined amount in the direction orthogonal to the width direction, printing in the width direction of the recording medium 16 in the next printing area is performed, and this operation is repeated. A serial method in which printing is performed over the entire printing area of the recording medium 16 may be applied.

(Configuration of supply system)
FIG. 13 is a schematic diagram showing the configuration of an ink supply system in the inkjet recording apparatus 10. The ink supply tank 60 is a base tank that supplies ink to the head 50 and is included in the ink storage / loading unit described above. The ink supply tank 60 includes a system that replenishes ink from a replenishment port (not shown) and a cartridge system that replaces the entire tank when the remaining amount of ink is low. A cartridge system is suitable for changing the ink type according to the intended use. In this case, it is preferable that the ink type information is identified by a barcode or the like, and ejection control is performed according to the ink type.

  As shown in FIG. 13, a filter 62 is provided between the ink supply tank 60 and the head 50 in order to remove foreign substances and bubbles. The filter mesh size is preferably equal to or smaller than the nozzle diameter (generally about 20 μm).

  Although not shown in FIG. 13, a configuration in which a sub tank is provided in the vicinity of the head 50 or integrally with the head 50 is also preferable. The sub-tank has a function of improving a damper effect and refill that prevents fluctuations in the internal pressure of the head.

  Further, the inkjet recording apparatus 10 is provided with a cap 64 as a means for preventing the nozzle 51 from drying or preventing an increase in ink viscosity near the nozzle, and a cleaning blade 66 as a means for cleaning the ink discharge surface of the head 50. Yes.

  The maintenance unit (maintenance means) including the cap 64 and the cleaning blade 66 can be moved relative to the head 50 by a moving mechanism (not shown), and is moved from a predetermined retracted position to a maintenance position below the head 50 as necessary. Moved.

  The cap 64 is displaced up and down relatively with respect to the head 50 by an elevator mechanism (not shown). The cap 64 is raised to a predetermined raised position when the power is turned off or during printing standby, and is brought into close contact with the head 50, thereby covering the nozzle surface with the cap 64.

  During printing or standby, if the frequency of use of a specific nozzle 51 is reduced and ink is not ejected for a certain period of time, the ink solvent near the nozzle evaporates and the ink viscosity increases. In such a state, ink cannot be ejected from the nozzle 51 even if the piezoelectric element 58 operates.

  Before such a state is reached (within the range of viscosity that can be discharged by the operation of the piezoelectric element 58), the piezoelectric element 58 is operated, and a cap is formed to discharge the deteriorated ink (ink in the vicinity of the nozzle whose viscosity has increased). Preliminary ejection (purge, idle ejection, collar ejection, dummy ejection) is performed toward 64 (ink receiver).

  Further, when air bubbles are mixed into the ink in the head 50 (in the pressure chamber 52), the ink cannot be ejected from the nozzle even if the piezoelectric element 58 is operated. In such a case, the cap 64 is applied to the head 50, the ink in the pressure chamber 52 (ink mixed with bubbles) is removed by suction with the suction pump 67, and the suctioned and removed ink is sent to the recovery tank 68.

  In this suction operation, the deteriorated ink with increased viscosity (solidified) is sucked out when the ink is initially loaded into the head or when the ink is used after being stopped for a long time. Since the suction operation is performed on the entire ink in the pressure chamber 52, the amount of ink consumption increases. Therefore, it is preferable to perform preliminary ejection when the increase in ink viscosity is small.

  The cleaning blade 66 is made of an elastic member such as rubber, and can slide on the ink ejection surface of the head 50 by a blade moving mechanism (not shown). When ink droplets or foreign matter adhere to the ink ejection surface, the ink ejection surface is wiped by sliding the cleaning blade 66 on the ink ejection surface, and the ink ejection surface is cleaned.

(Description of control system)
FIG. 14 is a principal block diagram showing the system configuration of the inkjet recording apparatus 10. The ink jet recording apparatus 10 includes a communication interface 70, a system control unit 72, an image memory 74, a motor driver 76, a heater driver 78, a fixing pressure control unit 79, a print control unit 80, an image buffer memory (not shown), and a head driver 84. , A permeation suppression agent application control unit 90, a treatment liquid application control unit 92, and the like.

  The communication interface 70 is an interface unit that receives image data sent from the host computer 86. As the communication interface 70, a serial interface such as USB (Universal Serial Bus), IEEE 1394, Ethernet (registered trademark), a wireless network, or a parallel interface such as Centronics can be applied. In this part, a buffer memory (not shown) for speeding up communication may be mounted. Image data sent from the host computer 86 is taken into the inkjet recording apparatus 10 via the communication interface 70 and temporarily stored in the image memory 74.

  The image memory 74 is a storage unit that temporarily stores an image or the like input via the communication interface 70, and data is read and written through the system control unit 72. The image memory 74 is not limited to a memory made of a semiconductor element, and a magnetic medium such as a hard disk may be used.

  The system control unit 72 includes a central processing unit (CPU) and its peripheral circuits, and functions as a control device that controls the entire inkjet recording apparatus 10 according to a predetermined program, and also functions as an arithmetic device that performs various calculations. To do. That is, the system control unit 72 controls the communication interface 70, the image memory 74, the motor driver 76, the heater driver 78, and the like, and performs communication control with the host computer 86, read / write control of the image memory 74, and the like. A control signal for controlling the motor 88 and the heater 89 of the transport system is generated.

  The image memory 74 stores programs executed by the CPU of the system control unit 72 and various data necessary for control. Note that the image memory 74 may be a non-rewritable storage means, or may be a rewritable storage means such as an EEPROM. The image memory 74 is used as a temporary storage area for image data, and is also used as a program development area and a calculation work area for the CPU. Further, a memory built in a processor constituting the system control unit 72 or the like may be used as the image memory 74.

  The motor driver 76 is a driver that drives the motor 88 in accordance with an instruction from the system control unit 72. In FIG. 14, the motor (actuator) arranged at each part in the apparatus is represented by reference numeral 88. For example, the motor 88 shown in FIG. 14 includes a motor that functions as a drive source for the recording medium transport unit 14 shown in FIG. 8, a motor that moves each part, a motor that moves the cleaning blade 66 shown in FIG. It is.

  The heater driver 78 is a driver that drives the heater 89 in accordance with an instruction from the system control unit 72. In FIG. 14, a plurality of heaters provided in the inkjet recording apparatus 10 are represented by reference numeral 89. For example, the heater 89 shown in FIG. 14 includes the heater of the permeation suppression agent drying unit 20 of FIG. 8, the heater of the treatment liquid drying unit 24, the heater of the ink drying unit 26, and the like.

  The print control unit 80 has a signal processing function for performing various processing and correction processes for generating a print control signal from the image data in the image memory 74 in accordance with the control of the system control unit 72. It is a control unit that supplies print data (dot data) to the head driver 84, the permeation suppression agent application control unit 90, and the treatment liquid application control unit 92. Necessary signal processing is performed in the print controller 80, and the ejection amount and ejection timing of the ink droplets of the head 50 are controlled via the head driver 84 based on the image data. Thereby, a desired dot size and dot arrangement are realized. Further, the application timing of the permeation suppression agent application unit 18 is controlled via the permeation suppression agent application control unit 90 based on the image data, and the processing liquid of the processing liquid application unit 22 is processed via the processing liquid application control unit 92. The application amount and application timing are controlled.

  The database storage unit 94 is a storage area in which various databases used for control of the apparatus are stored. The database storage area includes a paper type data storage area (see FIG. 2), a coat layer thickness, and a penetration inhibitor amount. This includes a storage area of a database in which the relationship is stored.

  Based on the automatically determined type of the recording medium, the thickness of the coating layer of the recording medium is determined with reference to the paper type data storage area, and a database of the relationship between the thickness of the coating layer and the amount of penetration inhibitor is determined based on the thickness of the coating layer. The amount of the penetration inhibitor is determined with reference to it. The permeation inhibitor amount storage area 96 stores the permeation inhibitor amount, and the permeation inhibitor application control unit 90 controls the permeation inhibitor application unit 18 based on the permeation inhibitor amount.

  The print control unit 80 includes an image buffer memory (not shown), and image data, parameters, and other data are temporarily stored in the image buffer memory when the print control unit 80 processes image data. Also possible is a mode in which the print control unit 80 and the system control unit 72 are integrated to form a single processor.

  The head driver 84 generates drive signals to be applied to the piezoelectric elements 58 of the heads 12C, 12M, 12Y, and 12K based on the image data given from the print control unit 80, and applies the drive signals to the piezoelectric elements 58. And a drive circuit for driving the piezoelectric element 58. The head driver 84 shown in FIG. 14 may include a feedback control system for keeping the driving condition of the head 50 constant.

  Image data to be printed is input from the outside via the communication interface 70 and stored in the image memory 74. At this stage, RGB image data is stored in the image memory 74.

  The image data stored in the image memory 74 is sent to the print control unit 80 via the system control unit 72, and is converted into dot data for each ink color by the print control unit 80. In other words, the print control unit 80 performs RIP processing for converting the input RGB raster data into dot data of four colors of KCMY. The dot data generated by the print controller 80 is stored in an image buffer memory (not shown). In addition, the dot data of the penetration inhibitor and the dot data of the treatment liquid are generated in the same manner.

  Various control programs are stored in a program storage unit (not shown), and the control program is read and executed in accordance with a command from the system control unit 72. The program storage unit may use a semiconductor memory such as a ROM or an EEPROM, or may use a magnetic disk or the like. An external interface may be provided and a memory card or PC card may be used. Of course, you may provide several recording media among these recording media. The program storage unit may also be used as storage means (not shown) for operating parameters.

  In the above apparatus configuration example, a configuration in which the recording medium is conveyed by the belt conveyance method is illustrated, but another conveyance method such as a drum conveyance method may be applied to the recording medium conveyance method. Also, a conveyance method in which each process such as permeation inhibitor application, treatment liquid application, ink droplet ejection, and drying is performed using an independent conveyance drum (impression cylinder), and a recording medium is transferred between the impression cylinders by a transfer cylinder. It is also applicable to.

[Description of penetration inhibitor]
The penetration inhibitor applied to the inkjet recording apparatus 10 shown in this example will be described. The composition example of the penetration inhibitor is as described in the composition of the penetration inhibitors A and B used in the above-described experiment, and the description is omitted here.

  In addition, the penetration inhibitor contains fine particles (thermoplastic resin) that becomes a film upon heating, and the thermoplastic resin becomes a film during the drying process after the application of the penetration inhibitor to form a penetration inhibitor layer. The

The glass transition temperature T _g of the thermoplastic resin used in the permeation suppression agent is preferably -10 ° C. or higher 100 ° C. or less, more preferably 10 ° C. or higher 70 ° C. or less, more preferably 30 ° C. or higher 50 ° C. or less.

When the glass transition temperature T _g of the thermoplastic resin is low, becomes easy to form a film on the nozzle face near the time of ejection, the ejection stability of the permeation suppression agent is lowered. On the other hand, there is a problem that needs to occur to apply a great deal of heat in the glass transition temperature T _g of the thermoplastic resin to form a high and coating. In addition, the thermoplastic resin has a form in which the resin is dissolved or dispersed in a particle state in a solvent to be described later, but when the permeation inhibitor is discharged, the viscosity of the whole solution is more dispersed in the particle state. Can be lowered, which is preferable. In the case of particles, the particle diameter is preferably in the range of 0.01 μm abnormality to 5 μm or less, and more preferably in the range of 0.05 μm abnormality to 1 μm or less. If the particle size is too small, there is a problem that the particles penetrate into the paper and a film cannot be formed on the surface. If the particle size is too large, a sufficient film cannot be formed even if heat is applied. There is a problem that particles are clogged. The weight percent concentration of the thermoplastic resin is preferably in the range of 1 wt% to 40 wt%, more preferably in the range of 5 wt% to 30 wt%, and still more preferably in the range of 10 wt% to 20 wt%.

  If the concentration of the thermoplastic resin is low, the thermoplastic resins do not sufficiently form a film, and there is a problem that some defects are formed. If the concentration is high, the storage stability of the liquid is poor (the resin is precipitated). ), The viscosity is too high.

The thermoplastic resin used in this example may be any one as long as it satisfies the above-mentioned glass transition temperature T _g , particle diameter, and weight percent concentration. Specifically, the olefin polymer and copolymer, chloride, Vinyl copolymers, vinylidene chloride copolymers, vinyl alkanoic acid polymers and copolymers, allyl alkanoic acid polymers and copolymers, polymers and copolymers of styrene and its derivatives, olefin-styrene olefin-unsaturated Carboxylic acid ester copolymer, acrylonitrile copolymer, methacrylonitrile copolymer, alkyl vinyl ether copolymer, acrylic acid ester polymer and copolymer, methacrylic acid ester polymer and copolymer, styrene Acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, itaconic acid diester polymer and Copolymer, maleic anhydride copolymer, acrylamide copolymer, methacrylamide copolymer, hydroxyl group-modified silicone resin, polycarbonate resin, ketone resin, polyester resin, silicone resin, amide resin, hydroxyl group and carboxyl group-modified polyester resin, Butyral resin, polyvinyl acetal resin, cyclized rubber-methacrylic acid ester copolymer, cyclized rubber-acrylic acid ester copolymer, a copolymer containing a heterocyclic ring (for example, a furan ring, a tetrahydrofuran ring, a thiophene as a heterocyclic ring) Ring, dioxane ring, dioxofuran ring, lactone ring, benzofuran ring, benzothiophene ring, 1,3-dioxetane ring), cellulose resin, fatty acid-modified cellulose resin, epoxy resin and the like.

  Next, a non-aqueous solvent for dissolving or dispersing the above-described thermoplastic resin will be described. As the non-aqueous solvent used in this example, the above-mentioned thermoplastic resin can be stably dissolved or dispersed, and the solvent itself does not curl even if it permeates into the paper, or the curl is slight If it is. Specifically, linear or branched aliphatic hydrocarbons, alicyclic hydrocarbons or aromatic hydrocarbons, and halogen-substituted products thereof can be used. For example, octane, isooctane, decane, isodecane, decalin, nonane, dodecane, isododecane, cyclohexane, cyclooctane, cyclodecane, benzene, toluene, xylene, mesitylene, Isopar E, Isopar G, Isopar H, Isopar L (Isopar; Exxon products) Name), shell sol 70, shell sol 71 (shell sol; trade name of Shell Oil), Amsco OMS, Amsco 460 solvent (Amsco; trade name of Spirits), etc. can be used alone or in combination.

[Description of treatment liquid]
The composition example of the treatment liquid (aggregation treatment liquid) applied to the ink jet recording apparatus 10 shown in this example is the same as the composition example of the treatment liquid used in the above-described experiment, and the description thereof is omitted here.

[Description of ink]
Below, the composition example of the ink (pigment ink) applied to the inkjet recording apparatus 10 shown in this example is shown.

<Pigment>
The method for producing the pigment is as follows.

  A dispersion liquid was prepared by stirring and mixing 10 g of Chromium Jet Magenta DMQ (PR-122), Ciba Specialty Chemicals, 10.0 g of polymer for dispersion, 4.0 g of glycerin, and 26 g of ion-exchanged water.

  Next, using the ultrasonic irradiation apparatus (Vibra-cell VC-750 manufactured by SONICS, taper microchip: φ5 mm, Amplitude: 30%), the above-mentioned dispersion is intermittently irradiated with ultrasonic waves (irradiation 0.5 sec / irradiation). The pigment was further dispersed by irradiation for 2 hours at a rest of 1.0 second to obtain a 20% by mass pigment dispersion.

<Ink>
In the ink jet recording apparatus 10 shown in this example, it is possible to use ink A, ink B, and ink C having the following compositions.

(Ink A)
Pigment (magenta): 4% by mass
Glycerin (made by Wako Pure Chemical Industries): 20% by mass
Diethylene glycol (manufactured by Wako Pure Chemical Industries): 10% by mass
Olfin E1010 (Nisshin Kagaku): 1% by mass
Ion-exchanged water: remaining (ink B)
Pigment (magenta): 4% by mass
Jonkrill 790 (manufactured by Johnson Polymer): 8 parts by mass Glycerin (manufactured by Wako Pure Chemical Industries): 20% by mass
Diethylene glycol (Wako Pure Chemical Industries): 10% by mass
Olfin E1010 (Nisshin Kagaku): 1% by mass
Ion-exchanged water: remainder The glass transition temperature (T _g ) of Joncrill 790 by DSC method is 90 ° C.
(Ink C)
Pigment (magenta): 4% by mass
Jonkrill 537 (manufactured by Johnson Polymer): 8 parts by mass Glycerin (manufactured by Wako Pure Chemical Industries): 20% by mass
Diethylene glycol (Wako Pure Chemical Industries): 10% by mass
Olfin E1010 (Nisshin Kagaku): 1% by mass
Ion-exchanged water: remainder The glass transition temperature (T _g ) of Joncrill 537 by DSC method is 40 ° C.

  The composition of the permeation inhibitor, the treatment liquid, and the ink described here is merely an example, and it is possible to appropriately apply those having other compositions.

  In this example, an ink jet recording apparatus that records a color image on a recording medium (paper) is illustrated, but the scope of the present invention is not limited to the ink jet recording apparatus, and a liquid is used for a recording medium having permeability. Therefore, the present invention can be widely applied to image forming apparatuses and liquid ejecting apparatuses that form shapes such as patterns.

  The image recording method and the image recording apparatus of the present invention have been described in detail above, but the present invention is not limited to the above examples, and various improvements and modifications are made without departing from the gist of the present invention. Of course it is also good.

<Appendix>
As will be understood from the description of the embodiments of the invention described in detail above, the present specification includes disclosure of various technical ideas including at least the invention described below.

  (Invention 1): A specifying step of specifying the thickness of a coating layer of a recording medium used for image recording, and the recording medium specified by the specifying step so that the curl of the recording medium falls within a predetermined range. A first treatment agent application amount determining step for determining an application amount of a first treatment agent having a function of suppressing the penetration of liquid into the recording medium in accordance with the thickness of the coating layer; and the first treatment agent application amount. A first treatment agent application step of applying an amount of the first treatment agent determined in the determination step to the recording medium; and the first treatment agent is applied to the recording medium by the first treatment agent application step. And an ink droplet ejection step of performing ink droplet ejection on the recording medium in accordance with input image data.

  According to the present invention, the application amount of the first treatment agent having a permeation suppressing effect according to the thickness of the coating layer of the recording medium so that the curling amount of the recording medium used for image recording falls within a predetermined range. Since the amount of the first processing agent appropriate for the recording medium is applied, curling of the recording medium is effectively suppressed, and the fixing property of the image due to excessive application of the first processing agent is reduced. Reduction is suppressed.

  As a means for applying the first treatment agent, a bar coating method, a roller coating method, an ink jet method, or the like can be applied.

  A preferred embodiment includes a heating step in which fine particles that are formed into a film by heating are dispersed in the first treatment agent, and the fine particles are formed into a film after application of the first treatment agent.

  (Invention 2): In the image recording method according to Invention 1, the relationship between the thickness of the coating layer of the recording medium and the application amount of the first treatment agent in which the curl of the recording medium falls within a predetermined range is stored. 1 treatment agent application amount storage step, and the first treatment agent application amount determination step is stored in advance by the first treatment agent application amount storage step based on the thickness of the coating layer determined by the specific step. The application amount of the first treatment agent is determined with reference to the relationship between the thickness of the coated layer and the application amount of the first treatment agent.

  According to this aspect, it is possible to effectively suppress curling of the recording medium so that the curling of the recording medium falls within a desired range. In addition, excessive application of the first processing agent can be avoided, and deterioration of image fixability is suppressed.

  The relationship between the thickness of the coat layer and the applied amount of the first treatment agent can be obtained by experiment, simulation, or the like.

  (Invention 3): The image recording method according to Invention 2, including a curl range setting step of setting a curl range of a recording medium used for image recording, wherein the first treatment agent application amount storage step includes The relationship between the thickness of the coat layer and the application amount of the first treatment agent corresponding to each of the plurality of curl ranges is stored, and the first treatment agent application amount determination step includes setting the thickness of the coat layer and the curl range setting. The application amount of the first treatment agent is determined with reference to the relationship with the application amount of the first treatment agent corresponding to the curl range set by the process.

  According to this aspect, a desired curl range is appropriately set by the user or the like, and the application amount of the first processing agent is optimized so that the curl of the recording medium falls within the range.

  (Invention 4): In the image recording method according to any one of Inventions 1 to 3, a coating layer thickness storing step for storing in advance a relationship between the type of the recording medium and the thickness of the coating layer of the recording medium; A recording medium type input step for inputting a type of the recording medium to be used, and the specifying step includes: the type of the recording medium stored in the coat layer thickness storage step and the thickness of the coat layer of the recording medium. With reference to the relationship, the thickness of the coating layer in the recording medium input in the recording medium type input step is determined.

  In such an aspect, an aspect including a recording medium determining step of automatically determining the type of the recording medium is preferable.

  (Invention 5): In the image recording method according to any one of Inventions 1 to 3, the specifying step includes a coat layer value input step of inputting a thickness value of a coat layer of a recording medium used for the image recording. It is characterized by including.

  (Invention 6): The image recording method according to any one of Inventions 1 to 3, wherein the specifying step includes a detection step of detecting a thickness of a coat layer of the recording medium.

  (Invention 7): In the image recording method according to any one of Inventions 1 to 6, in the first treatment agent application amount determining step, the thickness of the coating layer of the recording medium used in the specifying step cannot be specified. The predetermined value is used as the application amount of the first treatment agent.

  In this aspect, it is preferable that the predetermined value is determined based on the relationship between the thickness of the coat layer stored in advance in the first processing agent application amount storage step and the application amount of the first processing agent.

  (Invention 8): In the image recording method according to any one of Inventions 1 to 7, a second treatment agent having a function of aggregating color materials in ink or a function of thickening ink dots is applied to the recording medium. Including a second treatment agent application step.

  In such an embodiment, a bar coating method, a roller coating method, an ink jet method, or the like can be applied to the means for applying the second treatment agent.

  (Invention 9): In the image recording method according to any one of Inventions 1 to 8, the first treatment agent is a liquid in which resin particles are dispersed in an oily solvent or a liquid in which a resin is dissolved in an oily solvent. It is characterized by including.

  According to this aspect, the first treatment agent has a preferable penetration suppressing effect and exhibits a preferable curl suppressing effect.

  (Invention 10): The image recording method according to any one of Inventions 1 to 8, wherein the first processing agent contains a wax.

  According to this aspect, a more preferable permeation suppression effect is exhibited by including the wax in the first treatment agent.

  (Invention 11): First treatment agent application means for applying a first treatment agent having a function of suppressing liquid permeation to a recording medium used for image recording, and the thickness of the coating layer of the recording medium And the application amount of the first treatment agent according to the thickness of the coating layer of the recording medium specified by the specifying means so that the curl of the recording medium falls within a predetermined range. An inkjet head comprising: a first processing agent application amount control means that performs ink ejection on the recording medium in accordance with input image data after the first processing agent is applied. Recording device.

  In such an embodiment, it is preferable to disperse the fine particles that form a film by heating in the first treatment agent, and to provide a heating means for heating the recording medium to which the first treatment agent is applied after the first treatment agent is applied. .

1 is a conceptual diagram illustrating an image recording method according to an embodiment of the present invention. The flowchart which shows the example of control of the image recording method shown in FIG. Illustration of data table and default penetration inhibitor amount The figure which shows the experimental data for producing the data table shown in FIG. Figure supplementing the experimental data shown in FIG. The figure explaining the relationship between the coating layer thickness calculated | required from the experimental data shown in FIG. 3, and the amount of penetration inhibitors Diagram explaining the relationship between coat layer thickness and curl value 1 is an overall configuration diagram of an ink jet recording apparatus according to an embodiment of the present invention. FIG. 8 is a plan view of the main part around the printing unit of the ink jet recording apparatus shown in FIG. Plane perspective view showing a configuration example of the head shown in FIG. Sectional view along line AA in FIG. The enlarged view which shows the nozzle arrangement of the head shown in FIG. FIG. 8 is a schematic diagram showing the configuration of an ink supply system in the ink jet recording apparatus shown in FIG. FIG. 8 is a principal block diagram showing the system configuration of the ink jet recording apparatus shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Penetration inhibitor, 2 ... Treatment liquid, 3 ... Ink droplet, 10 ... Inkjet recording device, 12 ... Printing part, 16 ... Recording medium, 18 ... Penetration inhibitor provision part, 22 ... Treatment liquid provision part, 72 ... System control unit 74 ... Image memory 80 ... Print control unit 84 ... Head driver 90 ... Penetration inhibitor application control unit 94 ... Database storage unit 96 ... Penetration inhibitor storage area

Claims (11)

A specific step of specifying the thickness of the coating layer of the recording medium used for image recording;
A first process having a function of suppressing liquid permeation into the recording medium according to the thickness of the coating layer of the recording medium specified by the specifying step so that the curl of the recording medium falls within a predetermined range. A first treatment agent application amount determination step for determining the application amount of the agent;
A first treatment agent application step of applying an amount of the first treatment agent determined by the first treatment agent application amount determination step to the recording medium;
An ink droplet ejection step of performing ink droplet ejection on the recording medium according to input image data after the first treatment agent is imparted to the recording medium by the first treatment agent deposition step;
An image recording method comprising: The image recording method according to claim 1,
A first treatment agent application amount storage step for storing a relationship between the thickness of the coating layer of the recording medium and the application amount of the first treatment agent in which the curl of the recording medium falls within a predetermined range;
In the first treatment agent application amount determination step, the coating layer thickness and the first treatment stored in advance in the first treatment agent application amount storage step are based on the thickness of the coat layer determined in the specific step. An image recording method, wherein the application amount of the first treatment agent is determined with reference to a relationship with the application amount of the agent. The image recording method according to claim 2,
Including a curl range setting step for setting a curl range of a recording medium used for image recording,
The first treatment agent application amount storage step stores the relationship between the thickness of the coat layer and the application amount of the first treatment agent corresponding to each of a plurality of curl ranges,
The first treatment agent application amount determining step refers to the relationship between the thickness of the coat layer and the application amount of the first treatment agent corresponding to the curl range set by the curl range setting step. An image recording method comprising determining the amount of the agent applied. The image recording method according to any one of claims 1 to 3,
A coat layer thickness storage step for storing in advance a relationship between the type of the recording medium and the thickness of the coating layer of the recording medium;
Recording medium type input step for inputting the type of recording medium used for image recording;
Including
The specifying step refers to the relationship between the type of the recording medium stored in the coating layer thickness storage step and the thickness of the coating layer of the recording medium, and the coating on the recording medium input in the recording medium type input step An image recording method comprising determining the thickness of a layer. The image recording method according to any one of claims 1 to 3,
The specifying step includes a coat layer value input step of inputting a thickness value of a coat layer of a recording medium used for the image recording. The image recording method according to any one of claims 1 to 3,
The image recording method, wherein the specifying step includes a detecting step of detecting a thickness of a coat layer of the recording medium. The image recording method according to any one of claims 1 to 6,
In the first treatment agent application amount determining step, when the thickness of the coating layer of the recording medium used in the specifying step cannot be specified, a predetermined value is set as the application amount of the first treatment agent. An image recording method. In the image recording method of any one of Claims 1 thru | or 7,
An image recording method comprising: a second treatment agent application step of applying a second treatment agent having a function of aggregating a color material in ink or a function of thickening ink dots to the recording medium. The image recording method according to any one of claims 1 to 8,
The image processing method, wherein the first processing agent includes a liquid in which resin particles are dispersed in an oily solvent or a liquid in which a resin is dissolved in an oily solvent. The image recording method according to any one of claims 1 to 8,
The image recording method, wherein the first processing agent contains a wax. A first treatment agent applying means for applying a first treatment agent having a function of suppressing liquid permeation to a recording medium used for image recording;
A specifying means for specifying the thickness of the coating layer of the recording medium;
First treatment agent application for controlling the application amount of the first treatment agent according to the thickness of the coating layer of the recording medium specified by the specifying means so that the curl of the recording medium falls within a predetermined range. A quantity control means;
An ink jet head that performs ink droplet ejection on the recording medium in accordance with input image data after the first treatment agent is applied;
An ink jet recording apparatus comprising:

Images