JP2017024365A - Image recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image recording method which records an image that suppresses occurrence of beading and has glossiness when an impermeable base material is used.SOLUTION: There is provided an image recording method that includes: a step of imparting a treatment liquid containing water and a water-soluble cationic resin having cation density of 5.0 mmol/g or more and 9.0 mmol/g or less, onto an impermeable base material; and a step of imparting an ink composition containing water and particles of an urethane resin onto the impermeable base material to which the treatment liquid has been imparted by an inkjet method, where a ratio of the content of the cation resin contained in the treatment liquid per unit volume to the content of the particles of the urethane resin contained in the ink composition per unit volume is 0.3-1.8 in terms of mass.SELECTED DRAWING: None

Description

  The present invention relates to an image recording method.

  In printer systems that utilize digital technology, aqueous latex inks that are less odorous and advantageous in terms of safety are widely used from the viewpoint of recent environmental friendliness.

As an image recording method for forming an image on a recording medium such as paper based on an image data signal, there are an electrophotographic method, a sublimation type and a melt type thermal transfer method, an ink jet method and the like.
The ink jet method is an inexpensive device and has the advantage that the ink can be used efficiently and the running cost is low because the image is directly recorded on the recording medium by ejecting ink only to the required image area. Furthermore, there is little noise and it is excellent as an image recording method.

In recent years, an ink image formed on a resin recording medium by an ink composition has been increasingly used for applications such as large-area advertisements and outdoor advertisements.
The greatest advantage of the ink jet method is that it is suitable for producing wide images. There are a single pass method and a shuttle scan method as a recording method using the ink jet method. The former is a method of recording an image by preparing an inkjet head having a paper width and moving a recording medium with respect to the inkjet head. The merit of this method is that high-speed recording is possible, but as a demerit, when producing a wide image, it is necessary to arrange an ink jet head corresponding to the width, which increases the cost of the apparatus. is there. On the other hand, the shuttle scan method is a method of recording an image while moving a narrow inkjet head perpendicular to the paper traveling direction. Although it is not suitable for applications that require high-speed recording such as the single-pass method, it is an effective recording method in that the cost of the apparatus can be reduced when an image is recorded on a wide substrate. Such a shuttle scan type recording method is mainly used in the field of signs and displays.
Among ink compositions used in the fields of signs and displays, aqueous latex inks that are less odorous and advantageous in terms of safety have come to be widely used from the viewpoint of recent environmental measures.

  Such water-based ink is generally adjacent to the surface of the substrate when the image is recorded by an inkjet method on a non-permeable substrate using a hydrophobic resin such as polyvinyl chloride. A phenomenon (so-called beading) in which the ink droplets coalesce with each other and the base is seen in a bead shape to cause color unevenness is likely to occur. When beading occurs, the image quality is significantly reduced.

  As one of the techniques using the inkjet method, a printing method is disclosed in which heating and heating are performed from the side facing away from the ink landing surface of a recording medium in order to quickly dry and fuse when printing using latex ink. (For example, refer to Patent Document 1).

In addition, as one method for quickly fixing an ink to a recording medium, a liquid containing a compound that promotes aggregation of components contained in the ink (referred to as a fixing agent liquid, a fixing liquid, a processing liquid, or a reaction liquid). Have been proposed.
For example, an image forming method is disclosed in which an image is recorded on a paper base material such as coated paper using a fixing agent liquid containing a cationic polymer and an acidic precipitant and ink (for example, Patent Documents 2 to 2). 3). This image forming method is supposed to improve the abrasion resistance of the image.
In addition, an inkjet printing method is disclosed in which a pretreatment liquid containing a cationic resin as a flocculant is attached to a fabric, and then the ink composition is attached to perform printing (see, for example, Patent Document 4). Further, there is provided an image forming method for forming an image with reduced curl amount immediately after printing by attaching a pretreatment liquid to plain paper as a recording medium and then depositing ink on a surface to which the pretreatment liquid is attached. It is disclosed (for example, see Patent Document 5).

  There is also a disclosure relating to a method for obtaining a recorded matter by applying an ink composition containing acrylic resin particles to a recording medium to which a reaction liquid containing a calcium salt and an ammonium salt is applied (see, for example, Patent Document 6).

JP 2014-094549 A JP 2011-201259 A JP 2006-159907 A JP2015-040347A Japanese Unexamined Patent Publication No. 2014-094998 Japanese Unexamined Patent Publication No. 2015-074692

  However, among the above-described conventional techniques, the technique according to Patent Document 1 has an improvement effect on beading, but the quality tends to deteriorate due to heating depending on the type of recording medium.

  In addition, the technique described in Patent Documents 2 to 5, that is, a technique for recording an image on a water-permeable base material such as fabric or paper, is simply applied to a system for recording an image on a water-impermeable base material. Then, first, before applying the ink, not only is the beading likely to occur when the aqueous processing liquid is applied to the base material, but the ink is applied when the ink is applied to the processing liquid application surface of the base material to which the processing liquid has been applied. Ink bleeding is likely to occur due to the spread of the ink.

On the other hand, using a liquid containing a compound that promotes aggregation of components contained in the ink is effective as a technique for suppressing ink bleeding and forming a good quality image, but it impairs the glossiness of the image. There is a problem that it is easy. For example, as in Patent Documents 2 and 3, it is conceivable that in a method using a treatment liquid containing an acidic precipitant, rapid aggregation of the ink components occurs due to the presence of the acidic precipitant, and as a result, a latex ink film is formed. Is impeded and glossiness tends to be insufficient. In particular, in Patent Document 2, since a pigment in which an anionic polymer is covalently bonded is used, glossiness is further easily lost.
Patent Document 4 shows that the color forming property when printing is performed on a water-permeable fabric is improved by the aggregating action using the pretreatment liquid. As a result, gloss is reduced. In Patent Document 5, since the ink for ink jet recording contains a specific amide compound, the amide compound remains on the substrate even after drying after application of the ink. As a result, the film quality is poor and it is difficult to maintain gloss. .

  On the other hand, in Patent Document 6 in which a recording material is obtained by applying an ink composition containing an acrylic resin to a recording medium to which a reaction liquid containing a calcium salt and an ammonium salt is applied, the resin particles contained in the ink composition and Since acrylic resin is used as the water-soluble resin, the glossiness of the image is inferior.

  The present invention has been made in view of the above, and an object of the present invention is to provide an image recording method in which the occurrence of beading is suppressed and a glossy image is recorded when a non-permeable substrate is used. And to achieve this purpose.

  The beading means a color unevenness having a size of a bead ball (maximum diameter: 0.3 mm to 2 mm) visually recognized in an image. Beading is presumed to be a phenomenon that occurs when adjacent ink droplets of the ink droplets (dots) landed on the substrate move and move together.

Specific means for solving the above problems include the following embodiments.
<1> A step of applying a treatment liquid containing water and a water-soluble cationic resin having a cation density of 5.0 mmol / g or more and 9.0 mmol / g or less to a non-permeable substrate, and a treatment liquid A step of applying an ink composition containing water and urethane resin particles to the non-permeable base material by an inkjet method, and the entire region where the treatment liquid of the non-permeable base material is applied The ratio of the application amount of the cation resin per unit area in the region to the application amount per unit area of the urethane resin particles in the case where the ink composition is applied to 0.15 or more on a mass basis is 0 or more. The image recording method is in the range of 90 or less.
<2> The image recording method according to <1>, wherein the glass transition temperature of the urethane resin is 0 ° C. or higher and lower than 90 ° C.
<3> The image recording method according to <1> or <2>, wherein the ink composition further contains a pigment having at least a part of the surface coated with a resin.

<4> The image according to any one of <1> to <3>, wherein the treatment liquid and the ink composition further contain an organic solvent, and the content of the organic solvent having a boiling point of 250 ° C. or higher is less than 2% by mass. It is a recording method.
<5> The surface tension of the treatment liquid is 15 mN / m or more and 30 mN / m or less, and the surface tension of the ink composition is higher than the surface tension of the treatment liquid and 42 mN / m or less, <1> to <4> The image recording method according to any one of the above.
<6> At least one compound selected from the group consisting of a polymer in which the cationic resin has a structural unit represented by the following formula (1) and a polymer having a structural unit represented by the following formula (2): The image recording method according to any one of <1> to <5>.
In the following formula (1) or formula (2), Ra, Rb, Rc, and Rd each independently represents an alkyl group. The total carbon number of Ra and Rb is 2-4, and the total carbon number of Rc and Rd is 2-6. m and n each independently represent a positive integer.

<7> The non-permeable substrate is any one of <1> to <6>, which is a resin-coated paper in which at least a part of one side or both sides of a paper material is coated with a resin, or a resin molded body obtained by molding a resin. Or the image recording method according to any one of the above.
<8> The image recording method according to any one of <1> to <7>, wherein the non-permeable substrate has a thickness of 10 μm to 300 μm.
<9> The cationic resin according to any one of <1> to <8>, in which an aqueous solution having a concentration of 10% by mass has a viscosity at 25 ° C. of 0.5 mPa · s to 20 mPa · s. This is an image recording method.
<10> The image recording method according to any one of <1> to <9>, wherein the above-described ratio is in a range of 0.25 to 0.45 on a mass basis.

  According to the present invention, there is provided an image recording method in which the occurrence of beading is suppressed and a glossy image is recorded when an impermeable base material is used.

It is a schematic perspective view which shows an example of the inkjet recording device used for implementation of an image recording method. 2 is an enlarged view showing an example of a nozzle surface of the recording head 1. FIG. FIG. 6 is an enlarged view showing another example of the nozzle surface of the recording head 1 in an enlarged manner. It is a figure which shows the image sample corresponded in the rank 4 among the evaluation criteria of beading of an Example. It is a figure which shows the image sample corresponded to rank 1 among the evaluation criteria of beading of an Example.

Hereinafter, the image recording method of the present invention will be described in detail.
The image recording method of the present invention is a process of applying a treatment liquid containing water and a water-soluble cation resin having a cation density of 5.0 mmol / g or more and 9.0 mmol / g or less to a non-permeable substrate ( Hereinafter, it is also referred to as a “treatment liquid application step”), and a step of applying an ink composition containing water and urethane resin particles to an impermeable substrate to which the treatment liquid has been applied (hereinafter referred to as an ink jet method). In the case where the ink composition is applied to the entire region to which the treatment liquid of the non-permeable substrate has been applied, the non-permeable group of the urethane resin particles The ratio of the application amount of the cation resin per unit area in the region to which the treatment liquid of the non-permeable base material was applied to the application amount per unit area in the region to which the treatment liquid of material was applied was 0. 15 or more 0 or less of the range.

Conventionally, a technique for recording an image by an ink jet method has been studied from various viewpoints. As one of methods for quickly fixing an ink to a base material or enhancing color developability, an ink composition is used. There has been proposed a technique using a liquid (also referred to as a processing liquid) containing a compound that agglomerates the components contained therein.
When an image is recorded by applying a treatment liquid containing a compound that aggregates the components in the ink composition to the ink composition, for example, the dispersed components in the ink composition are easily fixed on the substrate due to the aggregation action. Although there is an effect of improving bleeding (ink bleeding), there is a case where fine irregularities on the surface of the image are generated due to aggregation, so that the glossiness of the image portion tends to be lowered. Even when the treatment liquid is used, when a water-impermeable substrate is selected as the recording medium, color unevenness called beading is likely to occur, and a desired image quality cannot always be obtained.
The reason why beading is likely to occur when recording an image on a water-impermeable substrate is not necessarily clear, but the aqueous processing liquid itself is non-uniform (for example, when the processing liquid is applied by an inkjet method, If the cohesive action of the treatment liquid is too weak, the ink droplets (dots) that have landed on the base material will easily move on the base material, and will be pulled together between the adjacent ink drops. In this case, it is presumed that a base color as large as a bead appears and color unevenness occurs.

In view of the above, in the present invention, when a non-permeable substrate is used, a resin liquid particle that is one of the dispersed components in the ink is formed on the non-permeable substrate with a highly homogeneous treatment liquid application surface. The cohesive force and the ease of spreading of ink droplets are balanced by paying attention to the cohesive force due to the treatment liquid.
Specifically, first, when the aggregation effect of the treatment liquid on the ink is too weak and the deposited ink droplets come into contact with each other and coalesce, the ink droplets move from the landing position, and the substrate Above, ink droplet uniformity cannot be maintained. In the present invention, by selecting a specific cationic resin as an aggregating component to be included in the treatment liquid, the ink droplets are provided with the aggregating properties necessary for fixing the ink droplets at the landing position, and on the substrate. The urethane resin particles are selected as the resin particles contained in the ink composition so that the uniformity of the deposited ink droplets can be maintained. Thereby, generation | occurrence | production of beading can be suppressed.
Secondly, when urethane resin particles are included as a dispersed component in the ink composition, gloss is improved. The reason why the gloss improvement effect is obtained is not clear, but the urethane resin particles are more flexible than, for example, acrylic resin particles, so that the landed ink droplets are spread while being subjected to agglomeration by the treatment liquid. It becomes easy and it becomes difficult for the resin particles to be unevenly distributed locally. In the case where the ink composition contains a pigment, the pigment is similarly hardly unevenly distributed. As a result, it is presumed that the presence of dispersed components such as resin particles and pigments in the ink composition is made uniform and a smooth surface is formed, which contributes to improvement of glossiness.

Therefore, in the present invention, a treatment liquid containing a cation resin having a predetermined cation density and an ink composition containing urethane resin particles are used, and the entire region to which the treatment liquid of the non-permeable substrate is applied. When applying the ink composition, the ratio of the cationic resin application amount per unit area to the urethane resin particle application amount per unit area in the region where the treatment liquid is applied is adjusted to a predetermined range. To do.
Thus, when an image is recorded using a water-impermeable substrate (that is, ink non-permeable), the dispersed component in the ink composition is brought into contact with the cationic resin, and the cationic resin is brought into contact with the cationic resin. In a recording system in which image recording is performed by receiving two types of agglomeration promoting effects of hydrophobization in the process of reducing and concentrating water later, the occurrence of beading is suppressed and an image having excellent gloss can be obtained. .

In the image recording method of the present invention, when the ink composition is applied to the entire region to which the treatment liquid of the non-permeable substrate is applied, the urethane resin particles are applied per unit area on the non-permeable substrate. The ratio of the applied amount of the cationic resin per unit area to the amount is set in the range of 0.15 to 0.90 on a mass basis.
Since the ratio of the applied amount of the cationic resin to the applied amount of the urethane resin particles is 0.15 or more, the amount of the cationic resin with respect to the urethane resin particles does not become too small. As a result, it is possible to suppress the occurrence of beading by holding the ink droplet landing position suitable for landing. In addition, the ink droplets can be easily spread by including the urethane resin particles, which is effective in suppressing the occurrence of beading.
Conversely, the ratio of the content of the cation resin to the content of the urethane resin particles is 0.90 or less, so that the amount of the cation resin with respect to the urethane resin particles does not increase excessively, so that the gloss is improved. Can keep. That is, the coagulation action can be maintained to such an extent that the gloss is not impaired. In addition, there is an effect of spreading ink droplets by including particles of urethane resin.
As described above, when the ratio of the content of the cationic resin to the content of the urethane resin particles is in the above range, the occurrence of beading is suppressed and an image having excellent glossiness is obtained.
Above all, from the viewpoint of suppressing the occurrence of beading and obtaining an image having excellent gloss and adhesion, on the non-permeable substrate, the unit with respect to the applied amount of urethane resin particles per unit area The ratio of the applied amount of the cationic resin per area is preferably in the range of 0.20 to 0.50, more preferably in the range of 0.25 to 0.45 on a mass basis.
The urethane resin particles and the cation resin are respectively contained in the ink composition or the treatment liquid within a range satisfying the above ratio within the range of the content described later.

(Non-permeable substrate)
In the image recording method of the present invention, an image is recorded on a non-permeable substrate (hereinafter also simply referred to as “substrate”).
The “non-permeable” of the non-permeable substrate means that the water contained in the treatment liquid and the ink composition is little or not absorbed. Specifically, the amount of absorbed water is 0.3 g / m. ^The property which is ² or less.
The amount of water absorbed by the base material was maintained at 25 ° C. for 1 minute in a state where water was in contact with an area of 100 mm × 100 mm of the image recording surface of the non-permeable base material. Is obtained, and the amount of absorption per unit area is calculated.

Examples of the non-permeable substrate include a substrate having a resin on at least one surface (preferably, a surface to which the treatment liquid and the ink composition are applied), a substrate having an easy-adhesion layer on the surface, and the like. .
For a base material having a resin on at least one surface, for example, a resin-coated paper in which at least a part of one or both sides of a paper material is coated with a resin, a resin molded body in which a resin is molded (for example, a resin plate (sheet) Shape) is included.

Examples of the resin described above include polyvinyl chloride (PVC), polyester (for example, polyethylene terephthalate (PET)), polyolefin (for example, polypropylene (PP), polyethylene (PE)), acrylic resin, polystyrene, polycarbonate, polyurethane, and the like. It is done.
Examples of polyvinyl chloride (PVC) include LAG jet series (for example, LAG jet P-224RW, LAG jet P-280RW, LAG jet P-284ZC) manufactured by Lintec.
Examples of polyethylene terephthalate (PET) include LAG jet series (for example, LAG jet E-2204RC, LAG jet G-1100EC) manufactured by Lintec.
Examples of the polyurethane include LAG jet series (for example, LAG jet U-1003RW) manufactured by Lintec.

  Moreover, as a base material which has an easily bonding layer on the surface, the polyethylene terephthalate which has an easily bonding layer on the surface is mentioned, As a specific example, Viewful UV series (for example, TP-50, TP-100, made by Kimoto) TP-188).

  Among the above, the non-permeable substrate is preferably a substrate having PVC, PET, PP, or PE on at least one surface (for example, the surface to which the treatment liquid and the ink composition are applied). Specifically, as an example of a non-permeable substrate, a resin-coated paper, PVC, PET, PP, or PE in which at least a part of one side or both sides of a paper material is coated with PVC, PET, PP, or PE The board | plate material etc. which shape | molded can be mentioned.

The thickness of the non-permeable substrate is preferably 10 μm or more and 300 μm or less. A substrate having a thickness in the above range is likely to cause cuckling when heated and dried in the drying step after applying the treatment liquid and the ink composition. Can also be suppressed.
Especially, as for the thickness of a non-permeable base material, 10 micrometers or more and 100 micrometers or less are more preferable.

  Hereinafter, the treatment liquid application step and the ink application step in the present invention will be described in detail, and the ink composition and the treatment liquid used in each step will be described in detail.

  In the present specification, “water-soluble” refers to the property of being soluble in water at a certain concentration or higher. “Water-soluble” preferably has a property of dissolving 5 g or more (more preferably 10 g or more) in 100 g of water at 25 ° C.

-Treatment liquid application process-
In the treatment liquid application step in the present invention, a treatment liquid containing water and a water-soluble cation resin having a cation density of 5.0 mmol / g or more and 9.0 mmol / g or less is applied to the non-permeable substrate. The treatment liquid contains a cationic resin having a relatively high cation density as a compound for aggregating the components (especially dispersion components) in the ink composition described later, so that the gloss does not deteriorate and aggregation is difficult to occur. An effect can be expressed.

~ Processing liquid ~
The treatment liquid contains water and a water-soluble cation resin having a cation density of 5.0 mmol / g or more and 9.0 mmol / g or less. Further, the treatment liquid may further contain other components such as an organic solvent and a surfactant as necessary.

(Cationic resin)
The treatment liquid contains at least one water-soluble cationic resin having a cation density of 5.0 mmol / g or more and 9.0 mmol / g or less. The treatment liquid in the present invention contains a cationic resin as a compound that aggregates the components in the ink composition.

  The cationic resin in the present invention is a cationic compound having an average molecular weight of 3000 or more, and the beading and glossiness are improved by being contained as a polymer component. Therefore, a low molecular weight cationic compound having an average molecular weight of less than 3000 cannot be expected to have the same effect because the aggregation rate is relatively fast, and is not included in the cationic resin referred to in the present invention.

  The average molecular weight of the cationic resin in the present invention is preferably in the range of 3,000 to 100,000 in terms of weight average molecular weight, more preferably 3,000 to 50,000, and even more preferably 5,000 to 25,000. When the weight average molecular weight is within the above range, the occurrence of beading is small, and it is effective to obtain an image superior in glossiness.

A weight average molecular weight (Mw) is calculated | required as a polystyrene conversion value by the gel permeation chromatography (GPC) of the conditions shown below. The calibration curve is prepared from three samples of “Standard Polyethylene Oxide”: “SE-2”, “SE-5”, and “SE-8” manufactured by Tosoh Corporation.
<Condition>
GPC: HLC (registered trademark) -8020 GPC (manufactured by Tosoh Corporation)
Column: TSKgel (registered trademark), G3000PWXL-CP (Tosoh Co., Ltd., 7.8 mm ID × 30 cm) 2 columns Eluent: 0.1 mol / L sodium nitrate Sample concentration: 0.3% by mass
・ Flow rate: 1.0 mL / min
Sample injection volume: 100 μl
・ Measurement temperature: 25 ℃
・ Detector: Differential refractometer (RI)

The cation density of the cation resin in the present invention is 5.0 mmol / g or more and 9.0 mmol / g or less. Since the cation density is 5.0 mmol / g or more, an aggregating action necessary for fixing at the landing position of the deposited ink droplets is obtained, and coalescence between adjacent ink droplets is suppressed. The occurrence of beading can be suppressed. In addition, the ink image can be excellently adhered to the substrate. Also, when the cation density is 9.0 mmol / g or less, the cohesive action on the ink composition does not become too strong, so the effect of improving the glossiness is high and the adhesion of the image to the substrate is also excellent. It can be.
Among them, the cation density is preferably 5.5 mmol / g to 8.0 mmol / g, and more preferably 6.0 mmol / g to 7.0 mmol / g for the same reason as described above.

  The cation density is a value calculated by specifying the compound structure of the cation resin and calculating the molar amount (mmol, mmol) of the cationic group with respect to the total mass (gram number) of the specified compound structure. The compound structure of the cationic resin can be specified by a nuclear magnetic resonance (NMR) method or mass spectrometry.

The cationic resin can be selected depending on the purpose from a polymer having a cationic group in the molecule (so-called cationic polymer), such as polyamine (for example, polyethyleneimine (PEI)), polyguanidine cationic polymer, Examples include water-soluble cationic dendrimers, polyallylamine salts (eg, hydrochloride), polydiallyldimethylammonium salts, (dimethylamine-epihalohydrin) copolymer salts, and poly (meth) acrylic acid amino ester salts. it can.
The polyguanidine cationic polymer is not particularly limited, and examples thereof include a polymer of hexamethylene guanide (HMG), a polymer of hexamethylene biguanide (HMB), and a copolymer of HMB and HMG.

  The cationic resin is preferably a compound selected from the group consisting of a polymer having a structural unit represented by the following formula (1) and a polymer having a structural unit represented by the following formula (2).

In formula (1) or formula (2), Ra, Rb, Rc and Rd each independently represents an alkyl group.
The alkyl group represented by Ra or Rb is preferably an alkyl group having 1 to 3 carbon atoms, and examples thereof include a methyl group, an ethyl group, and an isopropyl group, and a methyl group is preferable from the viewpoint of cohesion.
The alkyl group represented by Rc or Rd is preferably an alkyl group having 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, an isopropyl group, and a butyl group, and a methyl group is preferable in terms of cohesiveness. .
Among the above, the total carbon number of Ra and Rb is 2 to 4, and the total carbon number of Rc and Rd is 2 to 6 (preferably 2 to 4).
M and n each independently represent a positive integer and are selected within a range that satisfies the above average molecular weight.

  Specific examples of the cationic resin in the present invention (including a polymer having a structural unit represented by formula (1) or formula (2)) are shown below. N1 and n2 in the specific examples each independently represent a positive integer, and can be appropriately selected within a range satisfying the above average molecular weight. However, the present invention is not limited to the following specific examples.

  As the cationic resin, a commercially available product may be used. Examples of commercially available products include PHMB (polyhexamethylene biguanide) manufactured by FUJIFILM Imaging Colorants Co., Ltd., Catiomaster (registered trademark) PD series (amine / epichlorohydrin condensation type polymer manufactured by Daiichi Kogyo Seiyaku Co., Ltd.); For example, Cassimaster PD-5, PD-7, PD-10, etc.) and Senca Co., Ltd. Unisense series (for example, Unisense FPA100L, Unisense FPA102LU, Unisense FCA1000L, etc.) can be mentioned.

  In addition, as long as the effect of the present invention is not significantly impaired, a resin whose cation density is out of the range of 5.0 mmol / g or more and 9.0 mmol / g or less (for example, polyallylamine hydrochloride (PAA-manufactured by Nitteau Medical) HCL-01 etc.) may be used in combination.

The cationic resin preferably has a viscosity (25 ° C.) of 0.1 mPa · s to 20 mPa · s when an aqueous solution having a concentration of 10% by mass is prepared. When the viscosity at 25 ° C. is 0.1 mPa · s or more, it is advantageous in that the ink droplets of the treatment liquid are likely to be deposited at a desired position when the treatment liquid is applied to the substrate by ejecting by the inkjet method. It is. In addition, when the viscosity at 25 ° C. is 20 mPa · s or less, it is possible to maintain good dischargeability when the treatment liquid is discharged by the ink jet method.
In particular, the viscosity at 25 ° C. is more preferably in the range of 0.5 mPa · s to 15 mPa · s.
Here, the viscosity is adjusted to 25 ° C. with an aqueous solution prepared by dissolving an amount of a cationic resin in a concentration of 10% by mass in water, and a viscometer (VISCOMETER TV-22, manufactured by TOKI SANGYO CO. LTD) Is a value measured using.

The content of the cationic resin in the treatment liquid is preferably 0.01% by mass or more, more preferably 0.5% by mass or more, and still more preferably 1% by mass or more with respect to the total mass of the treatment liquid. Further, the content of the cationic resin in the treatment liquid is preferably 15% by mass or less, more preferably 10% by mass or less, and still more preferably 8% by mass or less with respect to the total mass of the treatment liquid.
When the content of the cationic resin is 0.01% by mass or more, an aggregating action with respect to components in the ink composition can be favorably expressed. In addition, when the content of the cationic resin is 15% by mass or less, the gloss becomes better while suppressing the occurrence of beading.

The application amount per unit area of the cationic resin applied to the non-permeable substrate is preferably 0.01 g / m ² or more and 1.0 g / m ² or less, and 0.05 g / m ² or more and 0.7 g / m ^{2. 2} or less is more preferable, and more preferably 0.1 g / m ² or more and 0.5 g / m ² or less. When the applied amount of the cationic resin is 0.01 g / m ² or more, an aggregating action necessary for fixing at the ink droplet landing position is obtained, and coalescence of adjacent ink droplets is suppressed. By doing so, occurrence of beading can be suppressed. In addition, the ink image adheres well to the substrate. When the applied amount of the cationic resin is 1.0 g / m ² or less, the effect of improving the glossiness is high, and the film quality of the image and the adhesion to the substrate are excellent.

(water)
The treatment liquid in the present invention contains water and is prepared as an aqueous composition.
Examples of water include ion-exchanged water and distilled water, and it is preferable to use water that does not contain ionic impurities.
The content of water in the treatment liquid is preferably 50% by mass to 90% by mass, and more preferably 60% by mass to 80% by mass with respect to the total mass of the treatment liquid.

(Organic solvent)
The treatment liquid may contain an organic solvent, for example, a water-soluble organic solvent.
The water-soluble organic solvent can be selected in the same range as the water-soluble organic solvent that can be included in the ink composition. Examples of the water-soluble organic solvent include alkyl polyol compounds, glycol ether compounds, amide compounds, etc., as will be described later, alkyl polyol compounds are preferred, wettability of the treatment liquid to the substrate, and drying properties after application. From the viewpoint of increasing the viscosity, an alkyl polyol compound having a boiling point of 180 ° C. or higher and 230 ° C. or lower is preferable.

There is no restriction | limiting in particular in content in the process liquid of an organic solvent, From the viewpoint of drying property, the range of 1 mass% or more and 50 mass% or less is preferable with respect to the whole process liquid, and 5 mass% or more and 30 mass% or less. A range is more preferred.
Moreover, when a processing liquid contains the organic solvent, it is preferable that content of the organic solvent whose boiling point is 250 degreeC or more is less than 2 mass%. If the content of the organic solvent having a boiling point of 250 ° C. or higher is less than 2% by mass, it is difficult for the organic solvent to remain after the drying step, and there is no need to increase the drying temperature so that no sticking occurs between the substrates. Therefore, the occurrence of cockle is also suppressed. Further, when the content of the organic solvent having a boiling point of 250 ° C. or higher is less than 2% by mass, the organic solvent does not remain in the recorded material, and thus the substrate adhesion is improved. Furthermore, the time until drying can be shortened, and image failures such as beading can be suppressed.
“The content is less than 2% by mass” means that the organic solvent having a boiling point of 250 ° C. or higher is substantially not contained, and the preferred content is less than 1% by mass, more preferably 0% by mass ( Do not contain).

  In this specification, “cuckle” refers to a phenomenon in which fine wrinkles occur on the surface of a substrate when an image is recorded, and any one of the shrinkage differences occurs between one side and the other side of the substrate. It is different from “curl” which is curled and deformed to the surface side. The same applies to the following.

(Surfactant)
The treatment liquid in the present invention can contain at least one surfactant as required. The surfactant can be used as a surface tension adjusting agent, for example.
As the surfactant, a compound having a structure having both a hydrophilic part and a hydrophobic part in the molecule can be suitably used. Anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants can be used. Any of the surfactants may be used.

As the surfactant, nonionic surfactants are preferable, and acetylene glycol derivatives (acetylene glycol surfactants) and fluorine surfactants are more preferable.
Examples of acetylene glycol surfactants include 2,4,7,9-tetramethyl-5-decyne-4,7-diol and 2,4,7,9-tetramethyl-5-decyne-4,7. -Alkylene oxide adduct of diol etc. can be mentioned. As the acetylene glycol surfactant, a commercially available product may be used, and examples of the commercially available product include E series (for example, Olphine E1010) manufactured by Nissin Chemical Industry Co., Ltd.
Examples of the fluorine surfactant include an anionic surfactant, a nonionic surfactant, and a betaine surfactant, and an anionic surfactant is more preferable. Examples of the anionic surfactant include Capstone FS-63, Capstone FS-61 (manufactured by Dupont), and a tangent series (manufactured by Neos Co., Ltd., for example, Fluorent 100, Fluorgent 110, Fluorgent 150), CHEMGUARD S-760P (manufactured by Chemguard Inc.), Surflon series (manufactured by AGC Seimi Chemical Co., for example, Surflon S242, Surflon S243, etc.) and the like.

  The treatment liquid may contain other additives in addition to the above components. Other additives include, for example, antifading agents, emulsion stabilizers, penetration enhancers, ultraviolet absorbers, antiseptics, antifungal agents, pH adjusters, antifoaming agents, viscosity modifiers, dispersion stabilizers, rust inhibitors Known additives such as agents and chelating agents are included.

~ Physical properties of treatment liquid ~
The physical properties of the treatment liquid in the present invention are not particularly limited, but preferably have the following physical properties.
(PH)
The pH of the treatment liquid is preferably 5.0 or more and 8.0 or less, and more preferably 5.0 or more and 6.0 or less at 25 ° C. (± 1 ° C.) from the viewpoint of the aggregation rate of the ink composition. When the pH of the treatment liquid is 5.0 or more, roughness of the substrate surface is less likely to occur, and image adhesion is further improved. When the pH of the treatment liquid is 8.0 or less, the aggregation rate is further improved, and coalescence of ink droplets (dots) by the ink composition on the substrate is further suppressed.
The pH is a value measured using a pH meter WM-50EG (manufactured by Toa DDK Co., Ltd.) in a 25 ° C. (± 1 ° C.) environment at 25 ° C. (± 1 ° C.). It is.

(viscosity)
The viscosity of the treatment liquid is preferably 1 mPa · s or more and 30 mPa · s or less, more preferably 1 mPa · s or more and 20 mPa · s or less, and further preferably 2 mPa · s or more and 15 mPa · s or less from the viewpoint of the aggregation rate of the ink composition. 2 mPa · s or more and 10 mPa · s or less is particularly preferable.
The viscosity of the treatment liquid is a value measured under a condition of 25 ° C. using a viscometer (VISCOMETER TV-22, manufactured by TOKI SANGYO CO. LTD).

(surface tension)
The surface tension of the treatment liquid is preferably 15 mN / m or more and 30 mN / m or less, more preferably 17 mN / m or more and 30 mN / m or less, and further preferably 18 mN / m or more and 28 mN / m or less from the viewpoint of the aggregation rate of the ink composition. preferable. When the surface tension is 15 mN / m or more, the treatment liquid can be easily applied to a desired position, and when the surface tension is 30 mN / m or less, the treatment liquid is applied to the non-permeable substrate. The occurrence of beading of the treatment liquid itself can be suppressed.
The surface tension is a value measured at 25 ° C. using a surface tension meter (Automatic Surface Tensiometer CBVP-Z, manufactured by Kyowa Interface Science Co., Ltd.).

  In the treatment liquid application step, a treatment liquid containing a component that aggregates the components in the ink composition (in particular, a cationic resin in the present invention) is applied to at least one surface of the non-permeable substrate. As a result, when an ink composition described later is applied to the treatment liquid application surface, dispersed particles including urethane resin particles in the ink composition are aggregated, and the image is fixed on the substrate.

  The treatment liquid can be applied by applying a known method such as a coating method, an ink jet method, or an immersion method. As a coating method, a known coating method using a bar coater, an extrusion die coater, an air doctor coater, a blade coater, a rod coater, a knife coater, a squeeze coater, a reverse roll coater, a bar coater or the like can be used. The details of the ink jet method are as described later.

The application amount when applying the treatment liquid to the non-permeable substrate is preferably 0.01 g / m ² or more and 20 g / m ² or less, more preferably 0.1 g / m ² or more and 15 g / m ² or less, and more preferably 1 g / m ^2. m ² or more and 10 g / m ² or less are more preferable. When the applied amount of the treatment liquid is 0.01 g / m ² or more, an aggregating action on the components in the ink composition is obtained, which is suitable for suppressing the occurrence of ink bleeding. On the contrary, if the application amount of the treatment liquid is 20 g / m ² or less, the application amount of the cationic resin to the non-permeable substrate does not become excessive, so that the aggregating action is too strong and the film formation by the ink composition is performed. It is possible to effectively suppress the deterioration of the film quality of the image and the reduction of the glossiness due to the inhibition of image quality.

  In the present invention, an ink application process is provided after the treatment liquid application process. Specifically, before applying the ink composition onto the non-permeable base material, a processing liquid is applied in advance to agglomerate the components in the ink composition, and the processing liquid applied onto the base material An ink composition is applied so as to come into contact with the ink and imaged. Thereby, inkjet recording can be speeded up, and an image having excellent density and resolution can be obtained even at high speed recording.

-Ink application process-
In the ink application process of the present invention, an ink composition containing water and urethane resin particles is applied to the non-permeable substrate to which the treatment liquid has been applied in the treatment liquid application process by an inkjet method.

~ Ink composition ~
The ink composition in the present invention contains water and urethane resin particles. The ink composition may further contain other components such as an organic solvent, a coloring material, a surfactant, urea, a water-soluble polymer compound, an antifoaming agent, and wax particles as necessary.

(Urethane resin particles)
The ink composition in the present invention contains at least one kind of urethane resin particles. The urethane resin particles suppress the occurrence of beading, improve the gloss, and improve the adhesion to the substrate. The inclusion of urethane resin particles is also advantageous in that the continuous dischargeability and discharge stability of the ink composition are further improved.
The urethane resin has a higher gloss improvement effect than the acrylic resin, and can further improve the adhesion to the substrate.

  As the urethane resin particles, particles containing at least one of the resins represented by UP-1 to UP-4 below are suitable.

In UP-1 to UP-4, R is an aliphatic group or an aromatic group. R ¹ is — (CH ₂ ) _m —COOH or — (CH ₂ CH ₂ O) _p —CH ₃ , m is an integer of 1 to 10, and p is an integer of 1 to 100. X is NH or O. n is an arbitrary natural number.

  The urethane resin represented by UP-1 to UP-4 preferably has an aspect in which a crosslink is present in the resin. This improves the shear stability of the urethane resin particles. In addition, the urethane resin represented by UP-1 to UP-4 preferably includes an acidic group in the resin from the viewpoint of improving dispersion stability when a dispersed state of particles is formed.

  Although it does not restrict | limit especially as a method of manufacturing the urethane resin represented by UP-1 to UP-4 and its preferable aspect, For example, the manufacturing method of Unexamined-Japanese-Patent No. 2006-241457 is suitable. That is, it is a production method in which an emulsion containing an isocyanate compound and an anionic surfactant is prepared, and a bifunctional, trifunctional or polyfunctional reactant is added thereto and stirred to produce a urethane resin.

  The urethane resin particles in the present invention are particularly preferably polyurethane having a structure represented by the following general formula (PU-1).

Here, R ₁ represents an aliphatic group or an aromatic group, and R ₂ represents a residue of the diol compound. The residue is preferably selected from an alkylene group, a polyether group, a polyester group, a polycarbonate group, and a polycaprolactone group.
Examples of the aliphatic group represented by R ₁ include a divalent group derived from isophorone diisocyanate (IPDI), hydrogenated m-xylene diisocyanate (H6XDI), hydrogenated diphenylmethane diisocyanate (H12MDI), hexamethylene diisocyanate (HDI), and the like. Is mentioned.
Examples of the aromatic group represented by R ₁ include divalent groups derived from m-xylene diisocyanate (XDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and the like.
Among these, R ₁ is more preferably an aliphatic group, and more preferably from the viewpoint of image durability. By selecting a relatively soft structure, it is presumed that the flexibility of the ink film after the ink is fixed on the base material is improved and the image durability is increased.
R ₂ represents a residue of a diol compound. The residue is preferably selected from an alkylene group, a polyether group, a polyester group, a polycarbonate group, and a polycaprolactone group, more preferably an alkylene group, a polyether group, a polyester group, and a polycaprolactone group, particularly preferably. Are an alkylene group having 1 to 30 carbon atoms, an alkyl ether group having 2 to 60 carbon atoms, and an alkyl ester group having 1 to 30 carbon atoms. This is presumably because by selecting a relatively soft structure, the flexibility of the ink film after the ink is fixed on the base material is improved and the image durability is increased.
M represents an integer and may be appropriately selected within a range satisfying the molecular weight shown below.

The molecular weight of the urethane resin is preferably 3000 to 200,000, more preferably 5000 to 150,000, and still more preferably 10,000 to 150,000 in terms of weight average molecular weight. A weight average molecular weight of 3000 or more is preferable in that the amount of water-soluble components is suppressed. Moreover, there exists an advantage that a dispersion stability is improved because a weight average molecular weight is 200,000 or less.
In addition, the weight average molecular weight of a urethane resin is a value measured by a gel permeation chromatograph (GPC).
GPC uses HLC-8020GPC (manufactured by Tosoh Corporation), and three columns of TSKgel (registered trademark) and Super Multipore HZ-H (manufactured by Tosoh Corporation, 4.6 mm ID × 15 cm). As THF (tetrahydrofuran). GPC is performed using a differential refractometer (RI) as a detector with a sample concentration of 0.45 mass%, a flow rate of 0.35 ml / min, a sample injection amount of 10 μl, and a measurement temperature of 40 ° C. The calibration curve is “Standard sample TSK standard, polystyrene” manufactured by Tosoh Corporation: “F-40”, “F-20”, “F-4”, “F-1”, “A-5000”, “A -2500 "," A-1000 ", and" n-propylbenzene ".

  The urethane resin may be either one having or not having a crosslinked structure in the molecule, but one having no crosslinked structure is more preferable from the viewpoint of image fixability.

  As the urethane resin particles, commercially available products may be used. Examples of commercially available products include Acrit (registered trademark) WBR-016U (glass transition temperature (Tg; the same applies below): 20 ° C.), Acrit (registered trademark) WBR-2018 (Tg: 20 ° C.), manufactured by Taisei Fine Chemical Co., Ltd. ACRYT (registered trademark) WBR-2000U (Tg: 45 ° C), ACRYT (registered trademark) WBR-600U (Tg: -30 ° C), ACRYT (registered trademark) WBR-2101 (Tg: 40 ° C), ACRYT (registered trademark) ) WEM-321U (Tg: 20 ° C.), PUE-1000, PUE-1020A, PUE-1370, PUE-800 manufactured by Murayama Chemical Laboratory, Takelac (registered trademark) W-5030 manufactured by Mitsui Chemicals (Tg: 85 ° C), Takelac (registered trademark) W-6010 (Tg: 90 ° C), Takelac (registered trademark) W-605 (Tg: 1) 0 ° C), Superflex 650, Superflex 860, Superflex 210 manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Neotan UE-1100 manufactured by Toagosei Co., Ltd. Ucourt UX-150 manufactured by Sanyo Chemical Industries, Ltd. Ucourt UWS-145, Barmarin UA-150, Vermarine UA-368, Iupile UXA-307, Implanil DLP-R (Tg 21 ° C.), Impranyl DLN (Tg-55 ° C.), Implanyl DLC-F (Tg-42) manufactured by Sumika Bayer Urethane Co., Ltd. ° C), Bihydrol (UH XP2648 (Tg-51 ° C), Dispacol U-53 (Tg-58 ° C), Permarin UA-150 (Tg36 ° C) manufactured by Sanyo Chemical Industries, UW-1005- manufactured by Ube Industries, Ltd. E (Tg-30 ° C), UW-5101-E (Tg69 ° C), etc. It can gel.

The glass transition temperature (Tg) of the urethane resin is preferably in the range of 0 ° C. or more and less than 90 ° C. When Tg is in the above range, the image recording apparatus can be operated in a safe temperature range that does not impair the image, and good glossiness is easily obtained. Further, when the Tg is less than 90 ° C., the film-forming temperature at the time of image recording does not become high, and when it becomes high, it is possible to suppress a decrease in gloss that tends to deteriorate, and the occurrence of cockle is also suppressed. This is advantageous.
Among them, the Tg of the urethane resin is more preferably in the range of 10 ° C to 85 ° C, further preferably in the range of 10 ° C to 50 ° C, and particularly preferably in the range of 20 ° C to 45 ° C.

As Tg, a measurement Tg obtained by actual measurement is applied.
Specifically, the measurement Tg means a value measured under normal measurement conditions using a differential scanning calorimeter (DSC) EXSTAR 6220 manufactured by SII Nanotechnology. However, when measurement is difficult due to polymer decomposition or the like, calculation Tg calculated by the following calculation formula is applied. The calculation Tg is calculated by the following formula (1).
1 / Tg = Σ (Xi / Tgi) (1)
Here, the polymer to be calculated is assumed to be copolymerized with n types of monomer components from i = 1 to n. Xi is the weight fraction of the i-th monomer (ΣXi = 1), and Tgi is the glass transition temperature (absolute temperature) of the homopolymer of the i-th monomer. However, Σ is the sum from i = 1 to n. As the glass transition temperature value (Tgi) of the homopolymer of each monomer, the value of Polymer Handbook (3rd Edition) (by J. Brandrup, EHImmergut (Wiley-Interscience, 1989)) is adopted.

  The Tg of the urethane resin can be appropriately controlled by a commonly applied method. For example, the Tg of the urethane resin can be controlled within a desired range by appropriately selecting the type, composition ratio, molecular weight, and the like of the compound that forms the urethane resin.

  The volume average particle diameter of the urethane resin particles is preferably in the range of 1 nm to 200 nm, more preferably in the range of 1 nm to 150 nm, still more preferably in the range of 1 nm to 100 nm, and particularly preferably in the range of 1 nm to 50 nm. Manufacturability is improved when the volume average particle diameter is 1 nm or more. Moreover, storage stability improves that a volume average particle diameter is 200 nm or less. Moreover, there is no restriction | limiting in particular regarding the particle size distribution of a polymer particle, Any of what has a wide particle size distribution or a monodispersed particle size distribution may be sufficient. Further, two or more kinds of polymer particles may be mixed and used.

  The volume average particle diameter of the urethane resin particles is a value measured by a particle size distribution measuring apparatus using a light scattering method. As the particle size distribution measuring apparatus, for example, Microtrack UPA (registered trademark) EX150 manufactured by Nikkiso Co., Ltd.) can be used.

  The content of the urethane resin particles in the ink composition is preferably 0.1% by mass to 20% by mass, more preferably 1% by mass to 15% by mass with respect to the total mass of the ink composition, and 2% by mass. It is particularly preferably 10 to 10% by mass. When the amount of the urethane resin is 20% by mass or less, it is possible to maintain good dischargeability, and when the amount of the urethane resin is 0.1% by mass or more, the durability of the image is excellent.

In untreated liquid permeability substrate is applied area, the application amount of the urethane resin particles per unit area is preferably from 0.010 g / ^{m 2} or more 1.50 g / ^{m 2} or less, 0.100 g / m ² or more and 1.00 g / m ² or less are more preferable, and more preferably 0.250 g / m ² or more and 0.750 g / m ² or less. When the applied amount of the urethane resin particles is 0.010 g / m ² or more, the durability of the image is excellent. When the applied amount of the urethane resin particles is 1.50 g / m ² or less, the discharge property can be maintained satisfactorily.

  In this invention, in the range which does not impair the effect of this invention, you may include the particle | grains of resin other than urethane resin. The other resin particles are preferably acrylic resin, polyether resin, polyester resin, and polyolefin resin particles, and more preferably acrylic resin particles from the viewpoint of stability and image quality. As other resin particles, commercially available products may be used. As examples of commercially available products, Joncryl 741 (Tg: 15 ° C., styrene / acrylic resin) manufactured by BASF Japan Ltd., Joncryl 775 (Tg: 37 ° C., styrene / acrylic resin), Jonkrill 537 (Tg: 49 ° C., styrene / acrylic resin), Jonkrill 538 (Tg: 66 ° C., styrene / acrylic resin), manufactured by Toagosei Co., Ltd. Particles of Aron HD-5 (Tg: 45 ° C., acrylic resin) and Movinyl 742N (Tg: 37 ° C., acrylic resin) manufactured by Nichigo.

(Organic solvent)
The ink composition in the invention can further contain at least one organic solvent.
As the organic solvent, for example, a water-soluble organic solvent can be contained. When the water-soluble organic solvent is contained together with the resin particles, the image film temperature of the resin particles contained in the ink composition can be lowered, and the ejection properties and the like are improved.

Examples of the water-soluble organic solvent include alkyl polyol compounds, glycol ether compounds, amide compounds, and sugars, sugar alcohols, hyaluronic acids, 1 to 4 carbon atoms described in paragraph 0116 of JP2011-42150A. Alkyl alcohols, glycol ethers, and the like.
Examples of the alkyl polyol compound include ethylene glycol (boiling point (bp; hereinafter the same) 196 ° C.), propylene glycol (bp 188 ° C.), 1,2-butanediol (bp 194 ° C.), 2,3-butanediol (bp 183 ° C.). 2-methyl-2,4-pentanediol (bp 198 ° C.), diethylene glycol (bp 244 ° C.), triethylene glycol (bp 287 ° C.), tetraethylene glycol (bp 328 ° C.), dipropylene glycol (bp 232 ° C.), 1,3- Propanediol (bp 214 ° C), 1,3-butanediol (bp203 ° C), 1,4-butanediol (bp230 ° C), 1,2-heptanediol (bp227 ° C), 3-methyl-1,3-butanediol (Bp 203 ° C.), 2-ethyl-2-methyl 1,3-propanediol (bp 226 ° C.), 2-methyl-2-propyl-1,3-propanediol (bp 230 ° C.), 2-methylpentane-2,4-diol (bp 197 ° C.), 2,2-dimethyl -1,3-propanediol (bp 208 ° C.), 2-methyl-1,3-propanediol (bp 214 ° C.), 1,2-pentanediol (bp 206 ° C.), 2,4-pentanediol (bp 201 ° C.), 1 , 5-pentanediol (bp242 ° C), 1,6-hexanediol (bp250 ° C), 2-ethyl-1,3-hexanediol (bp243 ° C), 1,2-hexanediol (bp224 ° C), 2,5 -Hexanediol (bp217 ° C) and the like.

  Examples of the glycol ether compound include ethylene glycol monoisobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monoisohexyl ether, diethylene glycol monohexyl ether, triethylene glycol monohexyl ether, diethylene glycol monoisohexyl ether, triethylene glycol monoisopropyl ether. Hexyl ether, ethylene glycol monoisoheptyl ether, diethylene glycol monoisoheptyl ether, triethylene glycol monoisoheptyl ether, ethylene glycol monooctyl ether, ethylene glycol monoisooctyl ether, diethylene glycol monoisooctyl ether, triethylene glycol monoisooctyl ether , D Lenglycol mono-2-ethylhexyl ether, diethylene glycol mono-2-ethylhexyl ether, triethylene glycol mono-2-ethylhexyl ether, diethylene glycol mono-2-ethylpentyl ether, ethylene glycol mono-2-ethylpentyl ether, ethylene glycol mono- 2-methylpentyl ether, diethylene glycol mono-2-methylpentyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, tripropylene glycol monomethyl ether Etc.

  Examples of amide compounds include 2-pyrrolidone and N-methyl-2-pyrrolidone.

  The alkyl polyol compound is preferably a compound having a boiling point of 180 ° C. or higher and 230 ° C. or lower from the viewpoint of improving the wettability and drying property of the ink. As a result, an image having excellent fixability can be recorded on a non-permeable substrate (including a substrate that is non-absorbing or low-absorbing with respect to the ink composition and the treatment liquid). Nozzle clogging can be reduced. Furthermore, the alkyl polyol compound is preferably a compound having a boiling point of 188 ° C. or higher and 230 ° C. or lower from the viewpoint that the ink composition is excellent in moisture retention, can easily suppress clogging of the nozzle, and can suppress a decrease in image fixability. .

  Moreover, the wettability to a base material can be adjusted by including a glycol ether compound.

  Among the above, from the viewpoint of improving the drying property of the ink composition, 50% by mass or more of the water-soluble organic solvent contained in the ink composition has a boiling point of 200 ° C. or less. Is preferred. Examples of water-soluble organic solvents having a boiling point of 200 ° C. or lower include ethylene glycol (bp 196 ° C.), propylene glycol (bp 188 ° C.), 1,2-butanediol (bp 194 ° C.), and 2,3-butanediol (bp 183 ° C.). 2-methyl-2,4-pentanediol (bp 198 ° C.), dipropylene glycol monomethyl ether (bp 190 ° C.), propylene glycol-n-butyl ether (bp 171 ° C.), propylene glycol-t-butyl ether (bp 153 ° C.), diethylene glycol methyl Examples include ether (bp 194 ° C.), ethylene glycol-n-propyl ether (bp 150 ° C.), and ethylene glycol-n-butyl ether (bp 171 ° C.).

  As a water-soluble organic solvent having a boiling point of 200 ° C. or lower, at least one of propylene glycol and 2,3-butanediol is used in that an ink composition having good compatibility with urethane resin particles and excellent film-forming properties can be obtained. It is preferable to contain. Thereby, glossiness can be improved more.

An organic solvent may be used individually by 1 type, and may be used in mixture of 2 or more types.
The content of the organic solvent in the ink composition is preferably 30% by mass to 55% by mass and more preferably 40% by mass to 55% by mass with respect to the total mass of the ink composition. When the content of the organic solvent is 30% by mass or more, moisture retention of the ink composition at the discharge nozzle is maintained, and dischargeability is easily maintained. Further, when the content of the organic solvent is 55% by mass or less, the drying property is improved and the generation of cockle can be suppressed.

Furthermore, the content of the alkyl polyol compound is improved with respect to the total mass of the ink composition from the viewpoint of improving the wettability to the non-permeable substrate and ensuring the storage stability and ejection reliability of the ink composition. 8 mass% or more and 25 mass% or less is preferable. When the content of the alkyl polyol compound is 8% by mass or more, the storage stability and moisture retention of the ink composition are improved. When the content of the alkyl polyol compound is 25% by mass or less, the ink composition does not have too high moisture retention, and an image with good fixability can be obtained.
Further, the content of the glycol ether compound is preferably 0.05% by mass or more and 6% by mass or less based on the total mass of the ink composition for the same reason as described above. When the content of the glycol ether compound is 0.05% by mass or more, the wettability and drying property of the ink composition are improved. When the content of the glycol ether compound is 6% by mass or less, the viscosity of the ink composition can be maintained appropriately, and the occurrence of nozzle clogging and the like can be reduced.

When the ink composition in the invention contains an organic solvent, the content of the organic solvent having a boiling point of 250 ° C. or higher is preferably less than 2% by mass. If the content of the organic solvent having a boiling point of 250 ° C. or higher is less than 2% by mass, it is difficult for the organic solvent to remain after the drying step, and there is no need to increase the drying temperature so that no sticking occurs between the substrates. Therefore, the occurrence of cockle is also suppressed. Further, when the content of the organic solvent having a boiling point of 250 ° C. or higher is less than 2% by mass, the organic solvent does not remain in the recorded material, and thus the substrate adhesion is improved. Furthermore, the time until drying can be shortened, and image failures such as beading can be suppressed.
“The content is less than 2% by mass” means that the organic solvent having a boiling point of 250 ° C. or higher is substantially not contained, and the preferred content is less than 1% by mass, more preferably 0% by mass ( Do not contain).

(water)
The ink composition in the present invention contains water.
Examples of water include ion-exchanged water and distilled water, and it is preferable to use water that does not contain ionic impurities.
The water content is not particularly limited, but can be, for example, 50% by mass or more based on the total amount of the ink composition. The water content is preferably 50% by mass or more and 80% by mass or less, more preferably 50% by mass or more and 75% by mass or less, and further preferably 50% by mass or more and 70% by mass or less with respect to the total amount of the ink composition. It is as follows.

(Coloring material)
The ink composition in the invention may further contain a color material. However, the ink composition in the present invention may be an ink containing no color material.

  When the ink composition of the present invention contains a color material, the color material preferably contains a pigment, and further, at least a part of the surface is coated with a resin (hereinafter also referred to as “coating resin”). More preferred are pigments (hereinafter also referred to as “resin-coated pigments”). By containing the resin-coated pigment, the dispersion stability of the ink composition is improved, and an image excellent in glossy quality can be obtained. Although the cause is not clear, for example, the aggregation reaction of the dispersed pigment in the ink composition with the cationic resin in the treatment liquid is slower than the aggregation reaction of the dispersed pigment not coated with the resin, It is conceivable that local pigment aggregation is less likely to occur, and gloss can be improved by more easily forming a more uniform resin film.

-Pigment There is no restriction | limiting in particular as a pigment, According to the objective, it can select suitably, For example, any of an organic pigment and an inorganic pigment may be sufficient. Further, a black pigment, a magenta pigment, a cyan pigment, and a yellow pigment may be used as the coloring pigment. The pigment is preferably a pigment that is almost insoluble or hardly soluble in water from the viewpoint of ink colorability.

  Examples of organic pigments include azo pigments, polycyclic pigments, dye chelates, nitro pigments, nitroso pigments, and aniline black. Among these, azo pigments and polycyclic pigments are more preferable. Examples of the inorganic pigment include titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow, and carbon black. Among these, carbon black is more preferable.

  When an organic pigment is used, the average particle diameter of the organic pigment is preferably small from the viewpoint of transparency and color reproducibility, but is preferably large from the viewpoint of light resistance. From the viewpoint of achieving both of these, the average particle size is preferably 10 nm to 200 nm, more preferably 10 nm to 150 nm, and even more preferably 10 nm to 120 nm. The particle size distribution of the organic pigment is not particularly limited, and may be either a wide particle size distribution or a monodispersed particle size distribution. Two or more kinds of organic pigments having a monodispersed particle size distribution may be mixed and used.

You may use a pigment individually by 1 type or in combination of 2 or more types.
The content of the pigment in the ink composition is preferably 1% by mass to 20% by mass and more preferably 2% by mass to 10% by mass with respect to the ink composition from the viewpoint of image density.

-Coating resin As a coating resin in a resin coating pigment, a dispersing agent is preferable.
The dispersant may be either a polymer dispersant or a low molecular surfactant type dispersant. The polymer dispersant may be either a water-soluble dispersant or a water-insoluble dispersant.

  As the low molecular surfactant type dispersant, for example, known low molecular surfactant type dispersants described in paragraphs 0047 to 0052 of JP2011-178029A can be used.

  Among polymer dispersants, water-soluble dispersants include hydrophilic polymer compounds. For example, natural hydrophilic polymer compounds include plant polymers such as gum arabic, tragacanth gum, guar gum, karaya gum, locust bean gum, arabinogalactone, pectin, quince seed starch, seaweeds such as alginic acid, carrageenan and agar. Examples include molecules, animal polymers such as gelatin, casein, albumin and collagen, and microorganism polymers such as xanthene gum and dextran.

In addition, in hydrophilic polymer compounds modified from natural products, fiber polymers such as methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose, starch such as sodium starch glycolate and sodium starch phosphate And seaweed polymers such as sodium alginate, propylene glycol alginate, and the like.
Furthermore, synthetic hydrophilic polymer compounds include vinyl polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, and polyvinyl methyl ether, non-crosslinked polyacrylamide, (meth) acrylic acid homopolymers or alkali metal salts thereof, water-soluble Acrylic resin such as styrene acrylic resin, water-soluble styrene maleic acid resin, water-soluble vinyl naphthalene acrylic resin, water-soluble vinyl naphthalene maleic acid resin, polyvinyl pyrrolidone, polyvinyl alcohol, alkali metal salt of β-naphthalene sulfonic acid formalin condensate, Examples thereof include a polymer compound having a salt of a cationic functional group such as quaternary ammonium or amino group in the side chain, and a natural polymer compound such as shellac.

  Among these, like a homopolymer of acrylic acid, a homopolymer of methacrylic acid, a water-soluble styrene acrylic resin, and a copolymer of acrylic acid, methacrylic acid or styrene acrylic acid and other monomers having a hydrophilic group, etc. A water-soluble dispersant having a carboxyl group introduced is preferred as the hydrophilic polymer compound.

Among the polymer dispersants, as the water-insoluble dispersant, a polymer having both a hydrophobic portion and a hydrophilic portion can be used. The hydrophilic structural unit is preferably a structural unit having an acidic group, and more preferably a structural unit having a carboxyl group. Examples of the water-insoluble resin include styrene- (meth) acrylic acid copolymer, styrene- (meth) acrylic acid- (meth) acrylic acid ester copolymer, (meth) acrylic acid ester- (meth) acrylic acid copolymer. Examples thereof include a polymer, a polyethylene glycol (meth) acrylate- (meth) acrylic acid copolymer, a vinyl acetate-maleic acid copolymer, and a styrene-maleic acid copolymer.
More specifically, for example, the water-insoluble resins described in JP-A-2005-41994, JP-A-2006-238991, JP-A-2009-084494, JP-A-2009-191134, and the like are preferably used in the present invention. Can be used.

  The weight average molecular weight of the polymer dispersant is preferably 3,000 to 100,000, more preferably 5,000 to 50,000, still more preferably 5,000 to 40,000, and particularly preferably 10,000. 000 to 40,000.

  In addition, the weight average molecular weight of a polymer dispersing agent refers to the value calculated | required by the method similar to the weight average molecular weight of the above-mentioned urethane particle.

  The polymer dispersant preferably contains a polymer having a carboxyl group from the viewpoints of self-dispersibility and aggregation rate when the treatment liquid comes into contact. The polymer dispersant has a carboxyl group and has an acid value of 130 mgKOH / g or less. It is preferable that the polymer has an acid value of 25 mgKOH / g to 120 mgKOH / g. A particularly preferable polymer dispersant is a polymer dispersant having a carboxyl group and having an acid value of 25 mgKOH / g to 100 mgKOH / g.

  The mixing mass ratio (p: s) between the pigment (p) and the coating resin (s) is preferably in the range of 1: 0.06 to 1: 3, more preferably in the range of 1: 0.125 to 1: 2. Preferably, it is 1: 0.125 to 1: 1.5.

  The content of the coating resin for coating the pigment with respect to the total mass of the ink composition is preferably 0.5% by mass to 3.0% by mass, more preferably 1.0% by mass to 2.8% by mass, and 1.2% by mass. % To 2.5% by mass is more preferable.

  The volume average particle size (secondary particle size) of the resin-coated pigment (pigment in a dispersed state) is preferably 10 nm to 200 nm, more preferably 10 nm to 150 nm, and even more preferably 10 nm to 100 nm. When the volume average particle diameter is 200 nm or less, the color reproducibility is good, and the droplet ejection characteristics when droplets are ejected by the ink jet method are good. When the volume average particle diameter is 10 nm or more, light resistance is improved. Further, the particle size distribution of the color material is not particularly limited, and may be either a wide particle size distribution or a monodisperse particle size distribution. Two or more color materials having a monodispersed particle size distribution may be mixed and used. Here, the volume average particle diameter of the pigment in the dispersed state indicates the average particle diameter in the ink state, but the same applies to the so-called concentrated ink dispersion in the previous stage before the ink is formed.

  Here, the volume average particle diameter of the resin-coated pigment is a value determined by the same method as the volume average particle diameter of the urethane resin particles described above.

Moreover, it is preferable that resin which coat | covers the pigment in a resin coating pigment is bridge | crosslinked with the crosslinking agent.
That is, the resin-coated pigment is preferably a resin-coated pigment in which at least a part of the surface of the pigment is coated with a resin crosslinked with a crosslinking agent.
Regarding the resin-coated pigment in which at least a part of the surface of the pigment is coated with a resin crosslinked with a crosslinking agent, paragraphs 0029 to 0048, paragraphs 0110 to 0118, and paragraphs 0111 to 0129 of JP2012-162655A. In addition, the description in paragraphs 0035 to 0071 of JP2013-47311A can be appropriately referred to.

The crosslinking agent is not particularly limited as long as it is a compound having two or more sites that react with a resin, but preferably has two or more epoxy groups from the viewpoint of excellent reactivity with a carboxy group. (A bifunctional or higher functional epoxy compound).
Specific examples of the crosslinking agent include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, diethylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, Examples include trimethylolpropane triglycidyl ether, and polyethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, and trimethylolpropane triglycidyl ether are preferable.

  A commercial item can also be used as a crosslinking agent. As a commercial item, Dencol EX-321, EX-821, EX-830, EX-850, EX-851 (made by Nagase ChemteX Corporation) etc. can be used, for example.

  The molar ratio of the crosslinking site of the crosslinking agent (for example, epoxy group) and the crosslinked site of the resin (for example, carboxy group) is preferably 1: 1 to 1:10 from the viewpoint of the crosslinking reaction rate and the dispersion stability after crosslinking. 1: 1 to 1: 5 is more preferable, and 1: 1 to 1: 1.5 is most preferable.

(Surfactant)
The ink composition in the present invention can contain at least one surfactant as required. The surfactant can be used as a surface tension adjusting agent, for example.
As the surfactant, a compound having a structure having both a hydrophilic part and a hydrophobic part in the molecule can be suitably used. An anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic interface Either an activator or a betaine surfactant may be used. Furthermore, the above-described polymer dispersant may be used as a surfactant.

The surfactant is preferably a nonionic surfactant from the viewpoint of suppressing ink droplet ejection interference, and more preferably an acetylene glycol derivative (acetylene glycol surfactant).
Examples of acetylene glycol surfactants include 2,4,7,9-tetramethyl-5-decyne-4,7-diol and 2,4,7,9-tetramethyl-5-decyne-4,7. -Alkylene oxide adduct of diol etc. can be mentioned, At least 1 sort (s) chosen from these is preferable. As a commercial item marketed, E series, such as Olphine E1010 of Nissin Chemical Industry, can be mentioned, for example.
As the surfactant other than the acetylene glycol surfactant, a fluorine surfactant is preferable. Examples of the fluorine surfactant include an anionic surfactant, a nonionic surfactant, and a betaine surfactant, and among these, an anionic surfactant is more preferable. Examples of the anionic surfactant include Capstone FS-63, Capstone FS-61 (manufactured by DuPont), Footgent 100, Footent 110, Footent 150 (manufactured by Neos Co., Ltd.), CHEMGUARD S-760P (Chemguard) Inc.).

When a surfactant (surface tension adjusting agent) is contained in the ink composition, the surfactant has a surface tension of 20 mN / m to 60 mN / m from the viewpoint of satisfactorily discharging the ink composition by an ink jet method. It is preferable to contain the quantity of the range which can be adjusted to m, More preferably, it is 20 mN / m-45 mN / m from the point of surface tension, More preferably, it is 25 mN / m-40 mN / m.
Here, the surface tension of the ink composition refers to a value measured using an Automatic Surface Tensiometer CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.) at a liquid temperature of 25 ° C.

  When the ink composition in the invention contains a surfactant, the specific amount of the surfactant is not particularly limited, but is preferably 0.1% by mass or more, more preferably based on the total amount of the ink composition. It is 0.1 mass%-10 mass%, More preferably, it is 0.2 mass%-3 mass%.

(urea)
The ink composition in the present invention can contain urea.
Since urea has a high moisturizing function, it can effectively suppress undesirable drying or coagulation of the ink as a solid wetting agent. Furthermore, the ink composition according to the present invention can further improve the maintainability (wiping workability) of an inkjet head or the like by including colloidal silica and urea described later.

  The content of urea in the ink composition is preferably 1% by mass or more and 20% by mass or less, more preferably 1% by mass or more and 15% by mass or less from the viewpoint of improving maintainability (wiping workability). % To 10% by mass is more preferable.

(Water-soluble polymer compound)
The ink composition in the present invention may contain at least one water-soluble polymer compound as necessary.
The water-soluble polymer compound is not particularly limited, and known water-soluble polymer compounds such as polyvinyl alcohol, polyacrylamide, polyvinyl pyrrolidone, and polyethylene glycol can be used.
Further, as the water-soluble polymer compound, a specific polymer compound that may be contained in a treatment liquid described later, or a water-soluble polymer compound described in paragraphs 0026 to 0080 of JP2013-001854A is also suitable. is there.

  When the ink composition in the invention contains a water-soluble polymer compound, the content of the water-soluble polymer compound is preferably 0.0001% by mass to 10% by mass with respect to the total amount of the ink composition, 0.01 The mass% is more preferably 3% by mass, more preferably 0.02% by mass to 0.5% by mass, and particularly preferably 0.03% by mass to 0.3% by mass.

(Defoamer)
The ink composition in the present invention may contain at least one antifoaming agent as required.
As an antifoamer, a silicone type compound (silicone type antifoamer), a nonionic compound, etc. are mentioned, for example. Of these, silicone antifoaming agents are preferred.
As the silicone-based antifoaming agent, a silicone-based antifoaming agent having a polysiloxane structure is preferable.
As the nonionic antifoaming agent, a compound having a polyethylene-polypropylene structure is preferable.

As the antifoaming agent, commercially available products can be used.
Commercially available products include BYK-012, 017, 021, 022, 024, 025, 038, 094 (above, manufactured by Big Chemie Japan), KS-537, KS-604, KM-72F (above, Shin-Etsu Chemical Co., Ltd.) ), TSA-739 (made by Momentive Performance Materials Japan GK), Olphine AF104 (made by Nissin Chemical Industry Co., Ltd.), Adeka Pluronic L, Adeka Pluronic P, Adeka Pluronic F, Adeka Pluronic R, Adeka Pluronic TR (Above, manufactured by ADEKA).
Among these, BYK-017, 021, 022, 024, 025, 094, KS-537, KS-604, KM-72F, and TSA-739, which are silicone-based antifoaming agents, are preferable, and ink ejection stability. From the viewpoint, BYK-024 is most preferable.

  When the ink composition in the present invention contains an antifoaming agent, the content of the antifoaming agent is preferably 0.0001% by mass to 1% by mass, and 0.001% by mass to 0% with respect to the total amount of the ink composition. More preferably, 1% by mass.

(Wax particles)
The ink composition in the present invention can contain at least one wax particle. By containing the wax, the abrasion resistance is further improved.

  As wax particles, for example, plant waxes such as carnauba wax, candeli wax, beeswax, rice wax, lanolin, petroleum waxes such as animal wax, paraffin wax, microcrystalline wax, polyethylene wax, oxidized polyethylene wax, petrolatum, Particles of natural wax or synthetic wax such as montan wax, mineral wax such as ozokerite, synthetic wax such as carbon wax, Hoechst wax, polyolefin wax, stearamide, α-olefin / maleic anhydride copolymer, etc. A mixed particle etc. are mentioned.

The wax is preferably added in the form of a dispersion. For example, the wax can be contained in the ink composition as a dispersion such as an emulsion. As a solvent in the case of a dispersion, water is preferable, but it is not limited thereto. For example, a commonly used organic solvent can be appropriately selected and used during dispersion. Regarding the organic solvent, reference can be made to the description of paragraph number [0027] of JP-A-2006-91780.
Wax particles can be used singly or in combination.

  As the wax particles, commercially available products may be used. Examples of commercially available products include Nopcoat PEM17 (manufactured by Sannopco), Chemipearl W4005 (manufactured by Mitsui Chemicals), AQUACER 515, AQUACER 593 (all of which are manufactured by Big Chemie Japan).

  Among the above, preferable waxes are carnauba wax and polyolefin wax, and carnauba wax is particularly preferable from the viewpoint of abrasion resistance.

  When the ink composition according to the present invention contains wax particles, the content ratio of the resin particles to the wax particles is a range of resin particles: wax particles = 1: 5 to 5: 1 (solid content ratio). Is preferred. When the content ratio is within the above range, the image has excellent abrasion resistance.

(Other ingredients)
In addition to the above components, the ink composition in the present invention may contain other components as necessary.
Examples of other components include solid wetting agents, anti-fading agents, emulsion stabilizers, penetration enhancers, ultraviolet absorbers, preservatives, antifungal agents, pH adjusting agents, viscosity adjusting agents, rust preventing agents, chelating agents, and the like. And known additives.

The ink composition in the present invention may be an active energy ray (for example, ultraviolet ray) curable ink composition containing at least one polymerizable compound. In this case, it is preferable that at least one of the ink composition and the treatment liquid further contains a polymerization initiator.
Examples of the polymerizable compound include polymerizations described in paragraphs 0128 to 0144 of 2011-184628, paragraphs 0019 to 0034 of JP2011-178896A, paragraphs 0065 to 0086 of JP2015-25076, and the like. Compounds (for example, bifunctional or higher functional (meth) acrylamide compounds).
Examples of the polymerization initiator are described in paragraphs 0186 to 0190 of JP2011-184628A, paragraphs 0126 to 0130 of JP2011-178896A, or paragraphs 0041 to 0064 of JP2015-25076A. A well-known polymerization initiator is mentioned.

~ Physical properties of ink composition ~
The physical properties of the ink composition in the invention are not particularly limited, but preferably have the following physical properties.
(PH)
The pH of the ink composition is preferably 7.5 or more at 25 ° C. (± 1 ° C.) from the viewpoint of the aggregation rate and dispersion stability in the ink composition. Among them, the pH (25 ° C. ± 1 ° C.) of the ink composition is preferably 7.5 to 13, and more preferably 7.5 to 10.
The pH of the ink composition can be appropriately adjusted using an acidic compound or a basic compound. As an acidic compound or a basic compound, the compound used normally can be especially used without a restriction | limiting.
The pH is measured by using a pH meter WM-50EG (manufactured by Toa DDK Co., Ltd.) in an environment of 25 ° C. (± 1 ° C.) with an ink composition adjusted to 25 ° C. (± 1 ° C.). Value.

(viscosity)
The viscosity of the ink composition is preferably in the range of 0.5 mPa · s to 10 mPa · s from the viewpoint of ejection stability and the aggregation rate of the urethane resin particles and the like when in contact with the treatment liquid.
The viscosity of the ink composition is a value measured by adjusting the ink composition at a temperature of 25 ° C. using a viscometer (VISCOMETER TV-22, manufactured by TOKI SANGYO CO. LTD).

(surface tension)
The surface tension of the ink composition is based on the surface tension of the treatment liquid (15 mN / m or more and 30 mN / m or less) from the viewpoint of ease of wetting on the treatment liquid application surface (that is, ease of wetting and spreading of ink droplets) and ejection stability. A range that is high and 42 mN / m or less is preferable. When the surface tension of the ink composition is higher than the surface tension of the treatment liquid, ink bleeding can be effectively suppressed. In addition, since the surface tension of the ink composition is 42 mN / m or less, when the ink composition is deposited on the substrate, beading is more likely to occur even when the ink droplets (dots) are coalesced. It is suppressed.
The surface tension of the ink composition is more preferably 15 mN / m or more and 42 mN / m or less, further preferably 20 mN / m or more and 42 mN / m or less, and particularly preferably 25 mN / m or more and 40 mN / m or less.
The surface tension of the ink composition is a value measured under an environment at a temperature of 25 ° C. using a surface tension meter (Automatic Surface Tensiometer CBVP-Z, manufactured by Kyowa Interface Science Co., Ltd.).

  In the present invention, the surface tension of the treatment liquid is preferably 17 mN / m or more and 30 mN / m or less, and the surface tension of the ink composition is preferably 20 mN / m or more and 42 mN / m or less. The case where the surface tension of the liquid is 18 mN / m or more and 28 mN / m or less and the surface tension of the ink composition is 25 mN / m or more and 40 mN / m or less is preferable.

The amount of the ink composition applied to the non-permeable substrate is preferably 0.01 g / m ² or more and 50 g / m ² or less, more preferably 0.1 g / m ² or more and 30 g / m ² or less, and more preferably 3 g / m ^2. m ² or more and 30 g / m ² or less are more preferable, and 10 g / m ² or more and 20 g / m ² or less are particularly preferable. When the applied amount of the ink composition is 0.01 g / m ² or more, the color density of the image becomes better. Further, when the applied amount of the ink composition is 50 g / m ² or less, the drying easily proceeds easily and the film quality is easily maintained.

-Ink application process-
In the image recording by the ink jet method, by applying energy, the above-described ink composition is ejected onto a desired recording medium to form an image. As a preferable inkjet method for the present invention, the method described in paragraphs 0093 to 0105 of JP-A No. 2003-306623 can be applied.

  The inkjet method is not particularly limited, and is a known method, for example, a charge control method that ejects ink using electrostatic attraction, a drop-on-demand method (pressure pulse method) that uses vibration pressure of a piezoelectric element, An acoustic ink jet system that converts an electrical signal into an acoustic beam, irradiates the ink with ink, and ejects the ink using radiation pressure, and a thermal ink jet that forms bubbles by heating the ink and uses the generated pressure (bubble jet (registered) Trademark)) method or the like.

  As an inkjet head, a short serial head is used, and a shuttle system that performs recording while scanning the head in the width direction of the recording medium, and a line head in which recording elements are arranged corresponding to the entire area of one side of the recording medium There is a line system using. The image recording method of the present invention can be applied to any of these.

  The amount of ink droplets ejected from the inkjet head is preferably 1 pl (picoliter) to 100 pl, more preferably 2 pl to 50 pl, from the viewpoint of obtaining a high-definition image. In addition, from the viewpoint of improving the unevenness of the image and the continuous gradation, it is also effective to discharge different amounts of liquids in combination, and even in such a case, the present invention can be suitably used.

In the treatment liquid application step and the ink application step described above, the application amount of the treatment liquid and the application amount of the ink composition can be appropriately adjusted as necessary. For example, the application amount of the treatment liquid may be changed according to the non-permeable substrate in order to adjust physical properties such as viscoelasticity of the aggregate formed by mixing the treatment liquid and the ink composition.
In the present invention, from the viewpoint of suppressing occurrence of beading and gloss, in the step of applying the treatment liquid, 0.1 g / m ^{2 to} 10 g per unit area on the surface of the non-permeable substrate on which an image is to be formed. In the step of applying the treatment liquid at an application amount of / m ² or less and applying the ink composition, 0.1 g / m ² or more per unit area on the surface of the non-permeable substrate on which an image is to be formed. An embodiment in which the ink composition is applied at an application amount of 30 g / m ² or less is preferable.

-Drying process-
In the image recording method of the present invention, a drying step may be further provided after at least one of the treatment liquid application step and the ink application step. Specifically, after the treatment liquid is applied on the non-permeable substrate, a drying step for drying the treatment liquid may be provided, or the ink composition is applied on the non-permeable substrate to which the treatment liquid is applied. After that, a drying step for drying the treatment liquid and the ink composition may be provided.
In the present invention, it is preferable to provide a drying step for drying the treatment liquid and the ink composition applied on the non-permeable substrate.

The drying in this step is preferably heat drying.
Examples of means for performing heat drying include known heating means such as a heater, known blower means such as a dryer, and a combination of these.
As a method for performing heat drying, for example, a method of applying heat with a heater or the like from the opposite side of the image recording surface of the recording medium, a method of applying warm air or hot air to the image recording surface of the recording medium, an image of the recording medium Examples thereof include a method of applying heat with an infrared heater from the side opposite to the recording surface or the image recording surface, a method of combining a plurality of these, and the like.

The heating temperature of the substrate during heat drying is preferably 35 ° C. or higher, more preferably 45 ° C. or higher, and particularly preferably 50 ° C. or higher.
Although there is no restriction | limiting in particular in the upper limit of the heating temperature of a base material, As an upper limit, 100 degreeC is mentioned, for example, 90 degreeC is preferable.
Although there is no restriction | limiting in particular in the time of heat drying, 1 second-60 minutes are preferable, 5 seconds-20 minutes are more preferable, and 10 seconds-5 minutes are especially preferable.

-Inkjet recording device-
The image recording apparatus that can be used in the image recording method of the present invention is not particularly limited, and is publicly known as described in JP 2010-830221 A, JP 2009-234221 A, JP 10-175315 A, and the like. Can be used.

  An example of an ink jet recording apparatus suitable for carrying out the image recording method of the present invention will be specifically described with reference to FIG. FIG. 1 is a schematic perspective view showing an example of an ink jet recording apparatus.

  The ink jet recording apparatus 10 is a wide format printer that records a color image on a substrate 12 using an ink composition and a treatment liquid. A wide format printer is a device suitable for recording a wide drawing range such as a large poster or a commercial wall advertisement. Here, the one corresponding to A3 Nobi or higher is called “wide format”.

  The ink jet recording apparatus 10 includes an apparatus main body 20 and support legs 22 that support the apparatus main body 20. The apparatus main body 20 includes a drop-on-demand type ink jet head 24 that ejects ink toward a base material 12 that is a recording medium, a platen 26 that supports the base material 12, and a head moving means (scanning means). A guide mechanism 28 and a carriage 30 are provided. Further, a dryer 34 is disposed downstream of the guide mechanism 28 in the substrate conveyance direction.

The inkjet head 24 may be the recording head 1 having the nozzle surface shown in FIG. FIG. 2 shows an example of the nozzle surface of the recording head 1 in an enlarged manner.
A plurality of discharge nozzles 2 a for discharging the processing liquid are arranged in one direction on the nozzle surface 1 b for discharging the processing liquid of the recording head 1. Further, the nozzle surface 1c for ejecting the ink composition of the recording head 1 is divided into four regions in a direction orthogonal to the arrangement direction of the ejection nozzles 2a in order to eject ink compositions of four colors having different hues. Yes. In each region, a plurality of ejection nozzles (ejection nozzles 2b, 2c, 2d, 2e) that eject the ink composition are arranged in parallel with the arrangement direction of the ejection nozzles 2a, and the ejection nozzles 2b, 2c, 2d are arranged. , 2e, a yellow ink composition, a magenta ink composition, a cyan ink composition, and a black ink composition are ejected, respectively.

FIG. 3 shows another configuration example of the nozzle surface of the recording head 1.
As shown in FIG. 3, the nozzle surface is divided into six regions in a direction orthogonal to the arrangement direction of the discharge nozzles in order to discharge the treatment liquid or the four-color ink compositions having different hues. Good. Out of the six regions, each region arranged at both ends is provided with a discharge nozzle 13a or 13b, and each of the discharge nozzles 13a and 13b is a discharge nozzle that discharges the processing liquid. The discharge nozzles 14a, 14b, 14c, and 14d are discharge nozzles that discharge a yellow ink composition, a magenta ink composition, a cyan ink composition, and a black ink composition, respectively.
In the recording head of this aspect, since the discharge nozzle for discharging the processing liquid is provided so as to sandwich the discharge nozzle for discharging the ink composition of each color, either the forward path or the return path in which the recording head reciprocates on the carriage is provided. It is also possible to record an image. That is, in either the forward path or the return path, the ink composition can be applied after the treatment liquid is applied, and conversely, the treatment liquid can be applied after the ink composition is applied. In addition, a difference in image density due to a different scanning direction of the recording head hardly occurs.

  Most preferably, the ink composition ejected from the recording head and the treatment liquid are stacked at the same location. However, in the present invention, it is not limited to the case where they are stacked at the same location, for example, when the ink composition is overlaid on the processing liquid applied by thinning out the processing liquid and enlarged by bleeding, etc. The case where the treatment liquid and the ink composition partially overlap with each other is also included.

The guide mechanism 28 extends in the anti-gravity direction of the platen 26 along a scanning direction (Y direction) that is orthogonal to the conveyance direction (X direction) of the substrate 12 and parallel to the substrate support surface of the platen 26. Are arranged to be.
The carriage 30 is disposed so as to be able to reciprocate in the Y direction along the guide mechanism 28. An ink jet head 24 is mounted on the carriage 30.
The dryer 34 can be configured by using a known heating means (for example, a heating element such as a heater), a blowing means (for example, a dryer) using ventilation, or a combination of the heating means and the blowing means. As a drying method using a dryer, a heater or the like is provided on the side opposite to the treatment liquid application surface of the base material (for example, when the base material is automatically transported, the base material non-mounting side of the transport mechanism that transports the base material) And a method of heating the substrate by heating the substrate, a method of applying warm air or hot air to the treatment liquid application surface of the substrate, a method of heating at least an image by radiant heat using an infrared heater, and the like. Moreover, the drying method which heats combining a several method may be sufficient.
An attachment portion 38 for the ink cartridge 36 is provided on the left front surface of the apparatus main body 20. The ink cartridge 36 is a replaceable ink supply source (ink tank) that stores an ink composition. The ink cartridge 36 is provided corresponding to each color ink composition to be used. Each color-specific ink cartridge 36 is connected to the inkjet head 24 by an ink supply path (not shown) formed independently.

  The substrate 12 to which the ink composition has been applied by the inkjet head 24 is conveyed to a drying zone 34 provided on the downstream side, and is heated in the drying zone 34 so that the ink is cured and an image is formed.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist thereof.

In the examples, the weight average molecular weight (Mw) of the polymer dispersant was measured by gel permeation chromatography (GPC) under the following condition 1. The calibration curve is “Standard sample TSK standard, polystyrene” manufactured by Tosoh Corporation: “F-40”, “F-20”, “F-4”, “F-1”, “A-5000”, “A -2500 "," A-1000 ", and" n-propylbenzene ".
<Condition 1>
GPC: HLC (registered trademark) -8020 GPC (manufactured by Tosoh Corporation)
-Column: TSKgel (registered trademark), Super Multipore HZ-H (manufactured by Tosoh Corporation, 4.6 mm ID x 15 cm)-Eluent: THF (tetrahydrofuran)
Sample concentration: 0.45% by mass
・ Flow rate: 0.35 ml / min
Sample injection volume: 10 μl
・ Measurement temperature: 40 ℃
・ Detector: Differential refractometer (RI)

The weight average molecular weight of the cationic resin was measured by GPC under the following condition 2. The calibration curve was prepared from three samples of “standard polyethylene oxide” manufactured by Tosoh Corporation: “SE-2”, “SE-5”, and “SE-8”.
<Condition 2>
GPC: HLC (registered trademark) -8020 GPC (manufactured by Tosoh Corporation)
Column: TSKgel (registered trademark), G3000PWXL-CP (Tosoh Co., Ltd., 7.8 mm ID × 30 cm) 2 columns Eluent: 0.1 mol / L sodium nitrate Sample concentration: 0.3% by mass
・ Flow rate: 1.0 mL / min
Sample injection volume: 100 μl
・ Measurement temperature: 25 ℃
・ Detector: Differential refractometer (RI)

  Further, the surface tension was measured at 25 ° C. using an Automatic Surface Tensiometer CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.). Viscosity was measured using VISCOMETER TV-22, TOKI SANGYO CO. (Manufactured by LTD). Moreover, pH was measured in 25 degreeC (+/- 1 degreeC) environment using pH meter WM-50EG (made by Toa DDK Co., Ltd.).

Example 1
<Preparation of magenta ink M1>
(Synthesis of polymer dispersant PD-1)
According to the following scheme, polymer dispersant PD-1 was synthesized as follows.

To a 1000 ml three-necked flask equipped with a stirrer and a condenser tube, 88 g of methyl ethyl ketone was added and heated to 72 ° C. in a nitrogen atmosphere. Here, 50 g of methyl ethyl ketone was mixed with 0.85 g of dimethyl 2,2′-azobisisobutyrate and 60 g of benzyl methacrylate. Then, a solution in which 10 g of methacrylic acid and 30 g of methyl methacrylate were dissolved was dropped over 3 hours. After completion of the dropwise addition, the mixture was further reacted for 1 hour, and then a solution of 0.42 g of dimethyl 2,2′-azobisisobutyrate in 2 g of methyl ethyl ketone was added, heated to 78 ° C. and heated for 4 hours. The obtained reaction solution was reprecipitated twice in an excess amount of hexane, the precipitated resin was dried, and benzyl methacrylate / methyl methacrylate / methacrylic acid (copolymerization ratio [mass ratio] = 60/30/10) 96 g of a polymer (polymer dispersant PD-1) was obtained.
The composition of the obtained polymer dispersant PD-1 was confirmed by a proton nuclear magnetic resonance ( ¹ H-NMR) method, and the weight average molecular weight (Mw) determined by the above method (GPC) was 44,600. The acid value determined by the method described in Japanese Industrial Standard (JIS K0070: 1992) was 65.2 mgKOH / g.

(Preparation of magenta pigment dispersion)
Pigment Red 122 (CROMOPHTAL Jet Magenta DMQ, manufactured by Ciba Specialty Chemicals, Inc .; magenta pigment), 10 parts by mass, 5 parts by mass of the above polymer dispersant PD-1, 42 parts by mass of methyl ethyl ketone, 1 mol / 5.5 parts by mass of an aqueous sodium hydroxide solution of L and 87.2 parts by mass of ion-exchanged water were mixed and dispersed by using a bead mill for 2 to 6 hours using 0.1 mmφ zirconia beads.
Methyl ethyl ketone was removed from the obtained dispersion under reduced pressure at 55 ° C., and a part of water was further removed. Further, a high-speed centrifugal cooler 7550 (manufactured by Kubota Seisakusho) was used and 8000 rpm using a 50 mL centrifuge tube. And centrifuged for 30 minutes. Here, the supernatant liquid other than the precipitate was collected. Thereafter, when the pigment concentration was determined from the absorbance spectrum of the supernatant, a dispersion (magenta pigment dispersion) of resin-coated pigment particles (resin-coated pigment coated with a polymer dispersant) having a pigment concentration of 15% by mass was obtained. It was.

(Preparation of magenta ink M1)
A magenta water-based ink (magenta ink M1) was prepared by mixing the components in the following composition. The surface tension (25 ° C.) of the obtained magenta ink M1 was 37.5 mN / m. The magenta ink M1 had a viscosity (25 ° C.) of 9.0 mPa · s and a pH (25 ° C. (± 1 ° C.)) of 8.5.
<Magenta ink composition>
-Magenta pigment dispersion (pigment concentration: 15% by mass) ... 20 parts by mass-Propylene glycol (manufactured by Sanyo Chemical Industries) ... 5 parts by mass-2-methyl-1,3-propanediol ... 35 Part by mass / Olfin E1010 ... 1 part by mass (manufactured by Nissin Chemical Industry Co., Ltd .; acetylene glycol surfactant)
-ACRYT WBR-016U (solid content concentration: 30% by mass) ... 10 parts by mass (manufactured by Taisei Fine Chemical Co., Ltd., dispersion of urethane resin particles)
・ Ion-exchanged water: the balance when the total amount of ink is 100 parts by mass (parts by mass)

<Preparation of treatment liquid P1>
Each component in the following composition was mixed to prepare a treatment liquid P1. The treatment liquid had a surface tension at 25 ° C. of 20.5 mN / m and a viscosity at 25 ° C. of 3.2 mPa · s. The pH (25 ° C. (± 1 ° C.)) was 7.5.
<Composition>
・ Cathiomaster PD7 (cationic resin): 4 parts by mass (dimethylamine / epichlorohydrin polycondensate, cation density: 7.3 mmol / g, solid content concentration: 50% by mass, viscosity when used as 10% by mass aqueous solution ( 25 ° C.): 2.0 mPa · s, weight average molecular weight: 5000; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
・ 2-Methyl-1,3-propanediol: 25 parts by mass ・ Surflon S243: 0.5 part by mass (fluorinated surfactant, manufactured by AGC Seimi Chemical Co., Ltd.)
・ Ion-exchanged water: Remaining part (mass part) when the total amount of treatment liquid is 100 parts by mass

<Image recording and evaluation>
-1. Image recording
Prepare GEN5 head (manufactured by Ricoh) as the printer head, replace the printer head of Fujifilm's printer Accuracy (registered trademark) 1600LED with two GEN5 heads, and fill one GEN5 head with the above processing solution P1 The other GEN5 head was filled with magenta ink M1.

Next, with respect to the polyvinyl chloride (PVC) sheet (P280RW, thickness: 80 μm, manufactured by Lintec Corporation), the treatment liquid was applied so that the applied amount was 6.0 g / m ² with a droplet amount of 10 picoliters (pl). P1 was discharged, and a 100% solid image of 600 dpi (dot per inch) was recorded (processing liquid application step). Note that the “solid image” is a surface image made of a processing liquid applied at a dot ratio of 100%. Thereafter, the magenta ink M1 is ejected onto the treatment liquid application surface of the PVC sheet on which the solid image of the treatment liquid is recorded so that the application amount is 12.5 g / m ² with the droplet amount of 10 picoliters (pl). A 100% solid image of 900 dpi was recorded (ink application step). The solid image here is a surface image formed by applying magenta ink at a dot ratio of 100%.
The PVC sheet on which the solid image was recorded was placed on a hot plate having a surface temperature of 60 ° C. so as to be in contact with the solid image non-recording surface, and the solid image non-recording surface was brought into close contact with the plate surface. In this state, the solid image was dried on the solid image by applying warm air (wind speed 7 m / s) from the solid image recording surface side for 60 minutes so that the substrate surface temperature became 60 ° C. Was fixed on the PVC sheet (drying step).
As described above, an image sample was obtained.

-2. Measurement / Evaluation
The following evaluations were performed on the image samples obtained as described above. The evaluation results are shown in Table 3 below.

(Beading)
The obtained image sample was visually observed, and the presence or absence of beading was evaluated according to the following evaluation criteria. The beading is a color unevenness of a size of a bead that is visually recognized in the image. As an evaluation sample for evaluating beading, an image sample corresponding to rank 4 in FIG. The image samples corresponding to rank 1 are shown in FIG.
<Evaluation criteria>
4: The occurrence of beading is not observed as in FIG. 4, and a uniform hue image is obtained.
3: Occurrence of beading as shown in FIG. 5 is not observed in the image sample, and there is no practical problem, but slight observation of beading is observed when the image sample is carefully observed.
2: The occurrence of beading as shown in FIG. 5 is observed in a part of the image sample.
1: The occurrence of beading is observed on the entire surface of the image sample as shown in FIG.

(Glossy)
Using a gloss meter (BYTRI, Micro TRI-gloss), the 20 ° gloss of the obtained image sample was evaluated according to the following evaluation criteria. Evaluation criteria 3 to 5 are in a range where there is no practical problem.
<Evaluation criteria>
5: The 20 ° glossiness is 40 or more.
4: 20 ° glossiness is 30 or more and less than 40.
3: 20 degree glossiness is 20 or more and less than 30.
2: 20 degree glossiness is 10 or more and less than 20.
1: 20 ° gloss is less than 10.

(Adhesion)
The image sample is allowed to stand for 1 hour in an environment of a temperature of 25 ° C. and a relative humidity of 50%, and a transparent adhesive tape (product name: plant-based cello tape (registered trademark), manufactured by Nichiban Co., Ltd.) is pasted on the surface of the solid image after being left. After attaching, the destruction state of the solid image when the transparent adhesive tape was peeled off was evaluated according to the following evaluation criteria.
<Evaluation criteria>
5: The image was not transferred to the tape.
4: Slight adhesive tape transfer was observed by careful observation 3: Part of the image was transferred to the adhesive tape, but exposure of the PVC sheet surface to the extent that it could be visually confirmed was not observed.
2: A part of the image was transferred to the adhesive tape, and a part of the surface of the PVC sheet was exposed to the extent that it could be visually recognized.
1: The image was transferred over the entire surface, and the surface of the PVC sheet was exposed.

(Examples 2-15, Comparative Examples 1-7)
In Example 1, treatment liquids P2 to P4 (treatment liquids for examples) and PH1 to PH4 (comparison treatment liquids) having the compositions shown in Table 1 below were prepared in the same manner as the preparation of the treatment liquid P1. . Similarly to the preparation of the magenta ink M1, magenta inks M2 to M12 (ink compositions for examples) and MH1 to MH3 (ink compositions for comparison) having the compositions shown in Table 2 below were prepared.
Using the prepared treatment liquids P2 to P4 and PH1 to PH4, and magenta inks M2 to M12 and MH1 to MH3, the treatment liquid P1 and the magenta ink M1 used in Example 1 were changed as shown in Table 3 below. Except that, an image sample was prepared and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

Details of the cationic resin in Table 1 are as shown below. “-” In Table 1 indicates that it is not contained (0% by mass). Note that n1, n2, n3, and n4 in the following chemical formulas each independently represent a positive integer.
-Unisense FPA100L: manufactured by Senka (concentration: 30% by mass, viscosity in the case of 10% by mass aqueous solution (25 ° C.): 1.2 mPa · s, weight average molecular weight: 15000, poly (diallyldimethylammonium chloride))
PAA-HCL-01: manufactured by Nitto Bo Medical Co., Ltd. (concentration: 33% by mass, viscosity at 25% aqueous solution (25 ° C.): 1.4 mPa · s, weight average molecular weight: 7000, polyallylamine hydrochloride)
-Charol DM-283P: manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. (concentration: 50% by weight, 10% by weight aqueous solution (25 ° C.): 18.2 mPa · s, weight average molecular weight: 28000, polydimethylmethacrylate) Ethyl methyl chloride)
・ Surflon S243: Fluorine-based surfactant manufactured by AGC Seimi Chemical Co., Ltd. ・ Orphine E1010: Acetylene glycol-based surfactant manufactured by Nissin Chemical Industry Co., Ltd.

Details of the components in Table 2 are as follows. “-” In Table 2 indicates that it is not contained (0% by mass).
Olfin E1010: acetylene glycol surfactant, manufactured by Nissin Chemical Industry Co., Ltd. WBR-600U: Acryt WBR-600U (water dispersion of urethane resin (emulsion), solid content: 34% by mass, manufactured by Taisei Fine Chemical Co., Ltd.)
-WBR-016U: Acryte WBR-016U (water dispersion (emulsion) of urethane resin, solid content: 30% by mass, manufactured by Taisei Fine Chemical Co., Ltd.)
WBR-2018: Acryte WBR-2018 (water dispersion (emulsion) of urethane resin, solid content: 32.5% by mass, manufactured by Taisei Fine Chemical Co., Ltd.)
-WBR-2101: Acryte WBR-2101 (water dispersion (emulsion) of urethane resin, solid content: 25% by mass, manufactured by Taisei Fine Chemical Co., Ltd.)
-WBR-2000U: Acryte WBR-2000U (water dispersion of urethane resin (emulsion), solid content: 32.5% by mass, manufactured by Taisei Fine Chemical Co., Ltd.)
W-5030: Takelac W-5030 (urethane resin aqueous dispersion (emulsion), solid content: 30% by mass, manufactured by Mitsui Chemicals)
W-6010: Takelac W-6010 (water dispersion (emulsion) of urethane resin, solid content: 30% by mass, manufactured by Mitsui Chemicals)
W-605: Takelac W-605 (water dispersion of urethane resin (emulsion), solid content: 30% by mass, manufactured by Mitsui Chemicals)
-Joncry (JONCRYL (registered trademark)) 538: aqueous dispersion (emulsion) of acrylic resin (styrene / acrylic resin), solid content: 46.5% by mass, manufactured by BASF Japan

As shown in Table 3 above, using a treatment liquid containing a cation resin having a specific cation density and an ink composition containing urethane resin particles, the content ratio between the cation resin and the urethane resin particles is within a specific range. In the example, it was possible to obtain an image with less beading and good gloss compared to the comparative example. Further, the image part was excellent in adhesion to the substrate.
On the other hand, in the comparative example in which the cation density of the cation resin is out of the range of 5.0 mmol / g or more and 9.0 mmol / g or less, the gloss is inferior, and the cation density is 5.0 mmol / g which is the lower limit. Therefore, in Comparative Example 2 where the aggregating action is weak, coalescence between adjacent ink droplets occurred, resulting in frequent beading, and as a result, the quality was significantly reduced. Furthermore, the adhesion to the substrate also decreased.
Further, in Comparative Examples 3 and 6 in which the ratio of the applied amount of the cation resin to the applied amount of the urethane resin particles is less than 0.15, the ink droplets coalesce due to the weak aggregating action on the ink droplets. Many dings occurred. Moreover, since the surface is not uniform, the glossiness is also deteriorated. On the contrary, in Comparative Examples 4 and 7, in which the ratio of the applied amount of the cationic resin to the applied amount of the particles of the urethane resin exceeds 0.90, the occurrence of beading is suppressed because it is difficult for coalescence to occur. Was too strong, and the glossiness was significantly reduced. Furthermore, the adhesiveness with respect to a base material also fell.
Comparative Example 5 containing acrylic particles as resin particles resulted in inferior results in all evaluations compared to Examples. This is presumed to be because the aggregation rate is different from the urethane resin particles used in the examples.

  In the above examples, the case where a PVC sheet was used as the non-permeable base material was shown. However, as with the PVC sheet, images were recorded using PET, PP, and PE molded sheets which are non-permeable base materials. Even in this case, the same effect as described above can be obtained.

Furthermore, when Example 1 and Example 4 in which the ratio of the content of the cation resin differs from the application amount of the urethane resin particles by changing the application amount of the cation resin are compared, Example 1 in which the ratio is within a preferable range. Was superior in terms of gloss and adhesion as compared to Example 4 which deviates from the preferred range.
In contrast to Example 1 and Example 3, Example 1 in which the surface tension of the treatment liquid is in the range of 15 mN / m to 30 mN / m is glossy and adhesive to Example 3 that is out of this range. It is shown that the surface tension of the treatment liquid works favorably in achieving both beading and glossiness and adhesion.
In comparison between Example 6 and Example 7, Example 7 containing a water-soluble organic solvent having a boiling point of 250 ° C. or higher is more susceptible to beading than Example 6 having a water-soluble organic solvent having a boiling point of less than 250 ° C. A worsening trend was observed. Moreover, in Example 7, adhesiveness also fell.
In comparison with Examples 9 to 14, in Examples 9 to 12 using a urethane resin having a Tg of less than 90 ° C., compared to Examples 13 to 14 using a urethane resin having a Tg of 90 ° C. or more, beading The results showed that the occurrence was reduced and the glossiness was good.

DESCRIPTION OF SYMBOLS 1 ... Recording head 1b, 1c ... Nozzle surface 2a, 2b, 2c, 2d, 2e, 13a, 13b, 14a, 14b, 14c, 14d ... Discharge nozzle 10 ... Inkjet recording device 20 ...・ Main body 24 ... Inkjet head 26 ... Platen 34 ... Dryer 36 ... Ink cartridge

Claims (10)

Applying a treatment liquid containing water and a water-soluble cationic resin having a cation density of 5.0 mmol / g or more and 9.0 mmol / g or less to a non-permeable substrate;
A step of applying an ink composition containing water and urethane resin particles to the non-permeable substrate to which the treatment liquid has been applied by an inkjet method;
And when the ink composition is applied to the entire region of the non-permeable substrate to which the treatment liquid has been applied, the application amount per unit area in the region of the urethane resin particles, The image recording method, wherein a ratio of the applied amount of the cationic resin per unit area in the region is in a range of 0.15 to 0.90 on a mass basis.   The image recording method according to claim 1, wherein the urethane resin has a glass transition temperature of 0 ° C. or higher and lower than 90 ° C.   The image recording method according to claim 1, wherein the ink composition further contains a pigment having at least a part of the surface coated with a resin.   The image recording according to any one of claims 1 to 3, wherein the treatment liquid and the ink composition further contain an organic solvent, and the content of the organic solvent having a boiling point of 250 ° C or higher is less than 2% by mass. Method.   The surface tension of the treatment liquid is 15 mN / m or more and 30 mN / m or less, and the surface tension of the ink composition is higher than the surface tension of the treatment liquid and 42 mN / m or less. The image recording method according to any one of the above. The cationic resin is at least one compound selected from the group consisting of a polymer having a structural unit represented by the following formula (1) and a polymer having a structural unit represented by the following formula (2). The image recording method according to any one of claims 1 to 5.


In formula (1) or formula (2), Ra, Rb, Rc and Rd each independently represents an alkyl group. The total carbon number of Ra and Rb is 2-4, and the total carbon number of Rc and Rd is 2-6. m and n each independently represent a positive integer.   The non-permeable base material is a resin-coated paper in which at least a part of one side or both sides of a paper material is coated with a resin, or a resin molded body obtained by molding a resin. The image recording method according to item.   The image recording method according to claim 1, wherein the non-permeable substrate has a thickness of 10 μm to 300 μm.   The image according to any one of claims 1 to 8, wherein the cationic resin has a viscosity at 25 ° C of 0.1 mPa · s to 20 mPa · s when an aqueous solution having a concentration of 10% by mass is prepared. Recording method.   The image recording method according to claim 1, wherein the ratio is in a range of 0.25 to 0.45 on a mass basis.