JP2009226599A - Image recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image recording method capable of preventing the occurrence of curl and cockle even when a general purpose printing paper is used in the image recording method using a reacting liquid and an ink composition. <P>SOLUTION: The image recording method comprises: a pretreatment liquid applying process of applying a pretreatment liquid containing a fluorine type surface active agent onto a recording medium; a reacting liquid applying process of applying a reacting liquid containing a reacting agent which is brought into contact with an ink composition to produce an aggregate, onto the recording medium having the pretreatment liquid applied thereon; and an ink applying process of applying an ink composition comprising a colorant, resin fine particles, a water soluble organic solvent and water onto the recording medium onto which the pretreatment liquid is applied. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image recording method.

Various image recording methods for recording a color image have been proposed in recent years. In any case, there are high demands on the quality of recorded matter such as image quality, texture, and curl after recording.
Among these, for example, the ink jet technology has been applied to the fields of office printers, home printers, and the like, but in recent years, it has been applied in the field of commercial printing. This commercial printing field does not have a photo-like surface that completely shuts out the penetration of the ink solvent into the base paper, but requires a printing texture like general-purpose printing paper. Here, when the solvent absorption layer in the recording medium is as thick as 20 to 30 μm, the surface gloss, texture, stiffness, etc. of the recording medium are limited. However, it is limited to posters, form printing, and the like that are allowed to be restricted in terms of surface gloss, texture, stiffness, etc. Further, the recording medium has a high cost due to the solvent absorption layer and the water resistant layer, which also contributes to the above limitation.

  On the other hand, as an ink jet recording method for forming a high-quality image, a liquid composition (reaction liquid) for improving the image is prepared separately from the normal ink jet ink, and the liquid composition is ejected from the recording ink. Prior to this, various methods for forming an image by adhering to a recording medium have been proposed (see, for example, Patent Documents 1 and 2).

On the other hand, a technique for adding a surfactant to a penetrating liquid for accelerating the penetration of an ink solvent into a recording medium (for example, see Patent Document 3), a technique for applying a cationic surfactant as an ink aggregating liquid (for example, Patent Document 4) and a technique for preventing intercolor bleeding using a silicon-based surfactant or a fluorine-based surfactant (for example, see Patent Document 5) are known.
JP-A-9-207424 JP 2006-188045 A Japanese Patent No. 3667160 Japanese Patent Laid-Open No. 9-248920 JP 2004-338392 A

However, the image forming method described in Patent Documents 1 and 2 includes a recording process in which the pigment ink is applied so as to be mixed in a liquid state with the reaction liquid on the print medium after the reaction liquid is applied to the surface of the recording medium. For this reason, when the pigment ink is formed alone, paper deformation such as deterioration of the fixing property of the image that has not occurred and curling or cockle of the recording medium may become remarkable. Further, when such paper deformation occurs, there is a possibility that paper jam occurs, the ink landing position shifts and the image quality deteriorates, or the recording surface comes into contact with the inkjet head and becomes dirty.
Furthermore, the surfactant used in the penetrating liquid and the ink aggregating liquid in the methods described in Patent Documents 3 to 5 is mainly for adjusting the surface tension, and prevents curling of the recording medium and deformation of the paper as a curl. I couldn't.
An object of the present invention is to provide an image recording method using a reaction liquid and an ink composition, which can suppress the occurrence of curling and cockle even with general-purpose printing paper.

Specific means for solving the above problems are as follows.
<1> An image recording method for forming an image using a colored ink composition, wherein a pretreatment liquid application step of applying a pretreatment liquid containing a fluorosurfactant on a recording medium; On the recording medium provided with the pretreatment liquid, a reaction liquid application step for applying a reaction liquid containing a reactive agent that contacts the ink composition to form an aggregate on the recording medium provided with the treatment liquid. And an ink application step of applying an ink composition comprising a colorant, resin fine particles, a water-soluble organic solvent, and water.
<2> The image recording method according to <1>, wherein the region to which the pretreatment liquid is applied on the recording medium has a contact angle with water of 85 degrees or more.
<3> In the <1> or <2>, in the pretreatment liquid application step, the application amount of the fluorosurfactant is 0.005 g / m ^{2 to} 0.5 g / m ^2. The image recording method as described.
<4> The image recording method according to any one of <1> to <3>, further comprising a drying removal step after the ink application step and the reaction liquid application step.
<5> The image recording method according to any one of <1> to <4>, wherein the reactant is a polyvalent metal salt or an acidic substance.

  According to the present invention, an image recording method using a reaction liquid and an ink composition can provide an image recording method capable of suppressing the occurrence of curling and cockle even with general-purpose printing paper.

  The image recording method of the present invention is characterized by including a pretreatment liquid application step of applying a pretreatment liquid containing a fluorosurfactant on a recording medium. A water-repellent layer can be formed on the recording medium by applying a pretreatment liquid containing a fluorosurfactant to the recording medium. By applying the reaction liquid and the ink composition onto the recording medium on which the water-repellent layer is formed, the occurrence of curling and cockle in the recording medium due to the solvent (particularly water) contained in the reaction liquid and the ink composition. Can be suppressed.

[Pretreatment liquid application process]
<Pretreatment liquid>
The pretreatment liquid includes at least one fluorine-based surfactant, and may include at least one water-soluble organic solvent and water as necessary.
The pretreatment liquid in the present invention can contain at least one colorant as required, but it is preferable not to contain a colorant from the viewpoint of image formability.

(Fluorosurfactant)
The fluorosurfactant used in the pretreatment liquid of the present invention is not particularly limited as long as it has fluorine atoms and can form a water repellent layer on the recording medium. For example, any of anionic, cationic, nonionic, and betaine types may be used, and it may be a low molecular compound or a high molecular compound.
In the present invention, an anionic fluorosurfactant or a cationic fluorosurfactant is preferable, and an anionic fluorosurfactant is more preferable, from the viewpoint of suppressing the occurrence of curling and cockle.

  The anionic fluorosurfactant or cationic fluorosurfactant is preferably a compound having a fluoroalkyl group and an anionic group or cationic group in the same molecule.

  From the viewpoint of water repellency, the fluoroalkyl group is preferably a fluoroalkyl group having 3 to 16 carbon atoms and having 6 to 32 fluorine atoms, and a perfluoroalkyl group having 3 to 10 carbon atoms. More preferably, it is a group.

  Examples of the anionic group include a carboxyl group, a phosphoric acid group, and a sulfonic acid group. Moreover, as said cationic group, an amino group, an alkylamino group, a dialkylamino group etc. can be mentioned, for example.

  Examples of the fluorosurfactant in the present invention include U.S. Pat. Nos. 2,559,751, 2,567,011, 2,732,398, 2,764,602, 2,806,866. No. 2,809,998, No. 2,915,376, No. 2,915,528, No. 2,918,501, No. 2,934,450, No. 2,937,098, 2,957,031, 3,472,894, 3,555,089, British Patents 1,143,927, 1,130,822, JP-B-45-37304, JP 47-9613, 49-134614, 50-117705, 50-117727, 50-112243, 52-41182, and 51-12392, J. Chem. Soc. 1950, 2789, 1957, 2574 and 2640, American Chemical Society Journal (J. Amer. Chem. Soc.) 79, 2549 (1957), Oil Chemistry (J. Japan Oil Chemists Soc.), 12, 653 Page, Journal of Organic Chemical Society (J. Org. Chem.), 30, 3524 (1965), and the like.

  The fluorosurfactant in the present invention may be appropriately synthesized by the above method or may be a commercially available fluorosurfactant. Examples of commercially available fluorosurfactants include MegaFac (trade name; manufactured by Dainippon Ink & Chemicals, Inc.), Footage (trade name; manufactured by Neos Co., Ltd.), and Zonyl (trade name: DuPont). And Fluorad (trade name: manufactured by Minnesota Mining and Manufacturing Company).

In the present invention, the fluorosurfactants may be used alone or in combination of two or more.
There is no restriction | limiting in particular as content rate of the fluorine-type surfactant in the said pre-processing liquid, For example, it can be set as 0.01-20.0 mass%, and 0.01-10. It is preferably 0% by mass, and more preferably 0.01 to 5.0% by mass.

The pretreatment liquid of the present invention can contain at least one water-soluble organic solvent as required. As the water-soluble organic solvent, a water-soluble organic solvent described later can be used without particular limitation.
There is no restriction | limiting in particular as content rate of the water-soluble organic solvent in a pre-processing liquid, For example, it can be set as 1-35 mass%, and it is preferable that it is 5-30 mass% from a viewpoint of curl suppression, More preferably, it is 25 mass%.

  In the present invention, the application of the pretreatment liquid to the recording medium can be performed by any known liquid application method without particular limitation, and may be applied by an inkjet method described later, or by an application roller or the like. Further, it may be applied to the entire recording medium or may be applied partially to an area where ink jet recording is performed. In the present invention, it is preferable to apply the entire surface to the entire recording medium from the viewpoint of curling due to the ink solvent and the suppression of cockle.

The pretreatment liquid application step in the present invention preferably further includes a dry removal step after the pretreatment liquid application. By performing dry removal of the solvent contained in the pretreatment liquid after application of the pretreatment liquid, the occurrence of curling and cockle can be more effectively suppressed.
The drying and removing step is not particularly limited as long as at least a part of the water and the water-soluble organic solvent contained in the pretreatment liquid can be removed. For example, drying can be performed by heating, drying air, or the like.

The application amount of the pretreatment liquid in the present invention is not particularly limited as long as a water-repellent layer can be formed on the recording medium, but the application amount of the fluorosurfactant is 0.005 g / m ^{2 to} 0. preferably ^{.5g / m 2, 0.01~0.1g / m} 2 is more preferable.
By setting it to 0.005 g / m ² or more, the occurrence of curling and cockle can be more effectively suppressed. Further, by setting it to 0.5 g / m ² or less, ink droplet ejection can be performed more favorably.

In the image recording method of the present invention, the recording medium to which the pretreatment liquid is applied preferably has a water contact angle of 85 degrees or more, and more preferably 90 degrees or more. When the contact angle of water is 85 degrees or more, penetration of water contained in the reaction liquid and the ink composition can be more effectively suppressed, and curling and cockle generation can be more effectively suppressed. it can.
The contact angle of water in the recording medium to which the pretreatment liquid is applied is the contact angle of water in the recording medium after the pretreatment liquid is applied and dried. In the present invention, the contact angle of water is measured by using DropMaster DM700 (manufactured by Kyowa Interface Science Co., Ltd.) as a measuring device, and dropping 0.3 μs of water on a recording medium to which a pretreatment liquid has been applied. This is done by measuring the contact angle of water when it has passed.

In order to increase the contact angle of water in the recording medium to which the pretreatment liquid has been applied to 85 degrees or more, for example, the application amount of the fluorosurfactant is increased (for example, 0.01 g / m ² or more), or fluorine is added. Examples of the surfactant include a method using a compound having a high fluorine atom content (for example, a compound having a larger number of perfluoroalkyl groups).

The pretreatment liquid application step in the present invention uses a compound having a perfluoroalkyl group having 3 to 10 carbon atoms and an anionic group or a cationic group as the fluorine-based surfactant, and the amount of the fluorine-based surfactant applied. Is preferably a step of applying a pretreatment liquid such that the concentration of the perfluoroalkyl group is 0.005 to 0.5 g / m ^2, and the fluorosurfactant is a perfluoroalkyl group having 3 to 10 carbon atoms and an anionic group. More preferably, it is a step of applying a pretreatment liquid using a compound having a pretreatment liquid such that the application amount of the fluorosurfactant is 0.005 to 0.5 g / m ² .

[Reaction solution application process]
The image recording method of the present invention includes a reaction liquid applying step of applying a reaction liquid containing a reactive agent that is brought into contact with the ink composition to form an aggregate on the recording medium to which the pretreatment liquid is applied. By applying the reaction solution onto the recording medium to which the reaction solution has been applied, the occurrence of curling and cockle can be effectively suppressed.
In the present invention, the reaction liquid application step may be before or after the ink application step described later as long as it is after the pretreatment liquid application step. It is preferably before the process.

<Reaction solution>
In the present invention, the reaction liquid contains at least one kind of a reactive agent that forms an aggregate when it comes into contact with the ink composition, and includes a water-soluble organic solvent, water, a surfactant, and the like as necessary. be able to. The reaction solution can further contain other additives appropriately selected as necessary.

(Reactant)
The reactant is not particularly limited as long as it can form an aggregate upon contact with the ink composition, and even a compound that can change the pH of the ink composition is a polyvalent metal salt. Or polyallylamines. In the present invention, from the viewpoint of the cohesiveness of the ink composition, the compound is preferably a compound that can change the pH of the ink composition, and more preferably the compound that can lower the pH of the ink composition. preferable.

Examples of the compound capable of lowering the pH of the ink composition include acidic substances such as phosphoric acid, polyacrylic acid, acetic acid, glycolic acid, malonic acid, malic acid, maleic acid, ascorbic acid, succinic acid, Glutaric acid, fumaric acid, citric acid, tartaric acid, lactic acid, sulfonic acid, orthophosphoric acid, pyrrolidone carboxylic acid, pyrone carboxylic acid, pyrrole carboxylic acid, furan carboxylic acid, pyridine carboxylic acid, coumaric acid, thiophene carboxylic acid, nicotinic acid, or It is preferably selected from derivatives of these compounds or salts thereof. These compounds may be used alone or in combination of two or more.
In the present invention, when the reaction solution contains an acidic substance, the pH of the reaction solution is preferably 1 to 6, more preferably 1 to 4, and still more preferably 2 to 4.

  Examples of the polyvalent metal salt include alkaline earth metals belonging to Group 2 of the periodic table (eg, magnesium, calcium), transition metals belonging to Group 3 of the periodic table (eg, lanthanum), and Group 13 of the periodic table. Mention may be made of salts of cations (for example, aluminum) and lanthanides (for example, neodymium). As these metal salts, carboxylate (formic acid, acetic acid, benzoate, etc.), nitrate, chloride, and thiocyanate are suitable. Among them, preferred are calcium salts or magnesium salts of carboxylic acids (formic acid, acetic acid, benzoates, etc.), calcium salts or magnesium salts of nitric acid, calcium chloride, magnesium chloride, and calcium salts or magnesium salts of thiocyanic acid.

The said reaction agent can be used individually by 1 type or in mixture of 2 or more types.
The content of the reaction agent for aggregating the ink composition in the reaction solution is preferably about 1 to about 10% by mass, more preferably about 1.5 to about 7% by mass, and still more preferably about 2 to about 10% by mass. It is in the range of 6% by mass.

  The water-soluble organic solvent, surfactant, and other additives that can be contained in the reaction liquid in the invention are the same as those in the ink composition described later.

  In the present invention, the application of the reaction liquid can be performed by any known liquid application method without particular limitation, and it may be applied by an ink jet method described later or by an application roller. Further, it may be applied to the entire recording medium or may be applied partially to an area where ink jet recording is performed. In the present invention, partial application to the area where ink jet recording is performed is preferable so that an unreacted reaction solution does not remain in the non-image area.

In the present invention, the application amount of the reaction liquid in the reaction liquid application step is not particularly limited as long as the ink composition described below can be aggregated. From the viewpoint of ink aggregation, the application amount of the reactant is 0. 0.5 to 5.0 g / m ² is preferable, and 0.7 to 3.0 g / m ² is more preferable.

It is preferable that the reaction liquid provision process in this invention further includes a drying removal process after reaction liquid provision. Image formation can be performed more favorably by removing the solvent contained in the reaction solution by drying after application of the reaction solution.
The drying and removing step is not particularly limited as long as at least a part of water and water-soluble organic solvent contained in the reaction solution can be removed. For example, drying can be performed by heating, drying air, or the like.

[Ink application process]
The image recording method of the present invention includes an ink application step of applying at least one ink composition containing a colorant, resin fine particles, a water-soluble organic solvent, and water onto a recording medium to which a pretreatment liquid has been applied. . By applying the ink composition to the recording medium to which the pretreatment liquid has been applied, the occurrence of curling and cockle can be effectively suppressed. The ink application step in the present invention is an ink composition from the viewpoint of image formability. The material is preferably applied by an ink jet recording method described later.
In the present invention, the ink application process may be before or after the reaction liquid application process as long as it is after the pretreatment liquid application process. Preferably after the process.

<Ink composition>
The ink composition in the present invention (hereinafter sometimes simply referred to as “ink”) includes at least one colorant, at least one resin fine particle, at least one water-soluble organic solvent, and water. If necessary, other components can be included.

The ink in the present invention can be used for full-color image formation. In order to form a full color image, a magenta color ink, a cyan color ink, and a yellow color ink can be used, and a black color ink may be further used to adjust the color tone. Further, red, green, blue and white inks other than yellow, magenta and cyan color inks, and so-called special color inks in the printing field can be used.
Hereinafter, the ink component will be described in detail.

(Coloring agent)
The colorant used in the present invention is not particularly limited as long as it has a function of forming an image by coloring, and pigments, dyes, and colored fine particles can be used. Of these, water-dispersible pigments are preferred.
Specific examples of the water-dispersible pigment include the following pigments (1) to (4).

(1) An encapsulated pigment, that is, a polymer emulsion in which a pigment is contained in polymer fine particles. More specifically, the pigment is coated with a hydrophilic water-insoluble resin and is made hydrophilic by a resin layer on the pigment surface. The pigment is dispersible in water.
(2) Self-dispersing pigments, that is, pigments having at least one hydrophilic group on the surface and exhibiting at least one of water dispersibility and water solubility in the absence of a dispersant, more specifically, mainly carbon black Etc. are hydrophilized by surface oxidation treatment so that the pigment alone is dispersed in water.
(3) A resin-dispersed pigment, that is, a pigment dispersed with a water-soluble polymer compound having a weight average molecular weight of 50,000 or less. (4) A surfactant-dispersed pigment, that is, a pigment dispersed with a surfactant.
Preferred examples include (1) encapsulated pigments and (2) self-dispersing pigments, and particularly preferred examples include (1) encapsulated pigments.

  The encapsulated pigment will be described in detail. The encapsulated pigment resin is not limited, but is a high molecular compound having self-dispersibility or solubility in a mixed solvent of water and a water-soluble organic solvent and having an anionic group (acidic). Is preferred. This resin usually has a number average molecular weight of about 1,000 to 100,000, and particularly preferably about 3,000 to 50,000. Further, it is preferable that this resin is dissolved in an organic solvent to form a solution. When the number average molecular weight of the resin is within this range, the function as a coating film in the pigment or as a coating film in the ink composition can be sufficiently exhibited. The resin is preferably used in the form of an alkali metal or organic amine salt.

Specific examples of encapsulated pigment resins include thermoplastic, thermosetting or modified acrylic, epoxy, polyurethane, polyether, polyamide, unsaturated polyester, phenol, silicone, and fluorine-based resins. Molecular compounds, polyvinyl chloride, vinyl acetate, polyvinyl alcohol, polyvinyl butyral, etc., polyesters such as alkyd resins, phthalic resins, melamine resins, melamine formaldehyde resins, aminoalkyd cocondensation resins, urea resins, urea resins, etc. Examples thereof include amino materials, or materials having an anionic group such as copolymers or mixtures thereof.
Among the above resins, anionic acrylic resins include, for example, acrylic monomers having an anionic group (hereinafter referred to as anionic group-containing acrylic monomers), and other monomers that can be copolymerized with these monomers as necessary. Is obtained by polymerization in a solvent. Examples of the anionic group-containing acrylic monomer include an acrylic monomer having one or more anionic groups selected from the group consisting of a carboxyl group, a sulfonic acid group, and a phosphonic group. Among these, an acrylic monomer having a carboxyl group Is particularly preferred.

Specific examples of the acrylic monomer having a carboxyl group include acrylic acid, methacrylic acid, crotonic acid, ethacrylic acid, propylacrylic acid, isopropylacrylic acid, itaconic acid, fumaric acid and the like. Among these, acrylic acid or methacrylic acid is preferable.
The encapsulated pigment can be produced by conventional physical and chemical methods using the above-described components. According to a preferred embodiment of the present invention, JP-A-9-151342, JP-A-10-140065, JP-A-11-209672, JP-A-11-172180, JP-A-10-25440, or JP-A-11-43636 It can be produced by the method disclosed in the issue.

In the present invention, self-dispersing pigments can also be mentioned as preferred examples. The self-dispersing pigment refers to a large number of hydrophilic functional groups and / or salts thereof (hereinafter referred to as dispersibility-imparting groups) on the pigment surface, either directly or indirectly via an alkyl group, an alkyl ether group, an aryl group, or the like. A pigment that is bonded and dispersible in an aqueous medium without a dispersant. Here, “dispersed in an aqueous medium without a dispersant” refers to a state in which the pigment can be dispersed in an aqueous medium without using a dispersant for dispersing the pigment.
Inks containing a self-dispersing pigment as a colorant do not need to contain a dispersant as described above that is contained in order to disperse a normal pigment. It is easy to prepare ink that is excellent in ejection stability.
Examples of dispersibility-imparting groups to be bonded to the surface of the self-dispersion _{pigment, -COOH, -CO -, - OH} , -SO 3 H, -PO 3 H 2 and quaternary ammonium and can be exemplified salts thereof, These are produced by subjecting a pigment as a raw material to physical treatment or chemical treatment to bond (graft) an active species having a dispersibility-imparting group or a dispersibility-imparting group to the surface of the pigment. Examples of the physical treatment include vacuum plasma treatment. Examples of the chemical treatment include a wet oxidation method in which the pigment surface is oxidized with an oxidizing agent in water, and a method in which a carboxyl group is bonded via a phenyl group by bonding p-aminobenzoic acid to the pigment surface. It can be illustrated.

  In the present invention, preferred examples include self-dispersing pigments that are surface-treated by oxidation treatment with hypohalous acid and / or hypohalite or oxidation treatment with ozone. Commercially available products can also be used as the self-dispersing pigment, such as Microjet CW-1 (trade name; manufactured by Orient Chemical Co., Ltd.), CAB-O-JET200, CAB-O-JET300 (above trade names). ; Manufactured by Cabot Corporation).

~ Pigment ~
There is no restriction | limiting in particular as a pigment used in this invention, According to the objective, it can select suitably, For example, any of an organic pigment and an inorganic pigment may be sufficient.
Examples of the organic pigment 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 azo pigments include azo lakes, insoluble azo pigments, condensed azo pigments, and chelate azo pigments. Examples of the polycyclic pigment include phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, and quinofullerone pigments. Examples of the dye chelates include basic dye chelates and acidic dye chelates.
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 particularly preferable. In addition, as said carbon black, what was manufactured by well-known methods, such as a contact method, a furnace method, and a thermal method, is mentioned, for example.

  Specific examples of carbon black include Raven7000, Raven5750, Raven5250, Raven5000 ULTRAII, Raven3500, Raven2000, Raven1500, Raven1250, Raven1200, Raven1170, Raven1170, Raven1170, Raven1170, Raven1170, Raven1170, Raven1170, Raven1170, Raven1170 (Manufactured by Carbon), Regal 400R, Regal 330R, Regal 660R, Mogu L, Black Pearls L, Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarc 1300, Monarch 1400 (above Cabot Corp.), Color Black FW1, Color Black FW2, Color Black FW2V, Color Black 18, Color Black FW200, Color Black S150, Color Black S150, Color Black S150, Color Black S150, Color Black FW200, Color Black FW200, Color Black FW2 , Printex 140U, Printex 140V, Special Black 6, Special Black 5, Special Black 4A, Special Black 4 (manufactured by Degussa), No. 25, no. 33, no. 40, no. 45, no. 47, no. 52, no. 900, no. 2200B, no. 2300, MCF-88, MA600, MA7, MA8, MA100 (manufactured by Mitsubishi Chemical Corporation) and the like can be mentioned, but the invention is not limited thereto.

  Examples of the organic pigment that can be used in the present invention include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 14C, 16, 17, 24, 34, 35, 37, 42, 53, 55, 65, 73, 74, 75, 81, 83, 93, 95, 97, 98, 100, 101, 104, 108, 109, 110, 114, 117, 120, 128, 129, 138, 150, 151, 153, 154, 155, 180 etc. are mentioned.

  Examples of magenta ink pigments include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 48 (Ca), 48 (Mn), 48: 2, 48: 3, 48: 4, 49, 49: 1, 50, 51, 52, 52: 2, 53: 1, 53, 55, 57 (Ca), 57: 1, 60, 60: 1, 63: 1, 63: 2, 64, 64: 1, 81, 83, 87, 88, 89, 90, 101 (Bengara) ), 104, 105, 106, 108 (cadmium red), 112, 114, 122 (quinacridone magenta), 123, 146, 149, 163, 166, 168, 170, 172, 177, 178, 179, 184, 185, 190, 193, 202, 209, 2 9,269, etc., and C. I. Pigment violet 19, especially C.I. I. Pigment Red 122 is preferable.

Further, as pigments for cyan ink, C.I. I. Pigment Blue 1, 2, 3, 15, 15: 1, 15: 2, 15: 3, 15:34, 16, 17: 1, 22, 25, 56, 60, C.I. I. Bat blue 4, 60, 63 and the like. I. Pigment Blue 15: 3 is preferable.
The above pigments may be used alone or in combination of a plurality selected from the above-mentioned groups or between the groups.

~ Dispersant ~
In the present invention, a nonionic compound, an anionic compound, a cationic compound, an amphoteric compound, and the like can be used as the dispersant used in the encapsulated pigment or the resin dispersion pigment.
Examples thereof include a copolymer of monomers having an α, β-ethylenically unsaturated group. Examples of monomers having an α, β-ethylenically unsaturated group include ethylene, propylene, butene, pentene, hexene, vinyl acetate, allyl acetate, acrylic acid, methacrylic acid, crotonic acid, crotonic acid ester, itaconic acid, itacone Acid monoester, maleic acid, maleic acid monoester, maleic acid diester, fumaric acid, fumaric acid monoester, vinyl sulfonic acid, styrene sulfonic acid, sulfonated vinyl naphthalene, vinyl alcohol, acrylamide, methacryloxyethyl phosphate, bismethacryloxy Styrene derivatives such as ethyl phosphate, methacryloxyethyl phenyl acid phosphate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, styrene, α-methylstyrene, vinyltoluene , Vinylcyclohexane, vinylnaphthalene, vinylnaphthalene derivatives, alkyl acrylates that may be substituted with aromatic groups, phenyl esters of acrylate, alkyl methacrylates that may be substituted with aromatic groups, phenyl esters of methacrylic acid, methacryl Acid cycloalkyl ester, crotonic acid alkyl ester, itaconic acid dialkyl ester, maleic acid dialkyl ester, vinyl alcohol, and derivatives of the above compounds.

  A copolymer obtained by copolymerizing a single monomer or a plurality of monomers having the α, β-ethylenically unsaturated group is used as a polymer dispersant. Specifically, acrylic acid alkyl ester-acrylic acid copolymer, methacrylic acid alkyl ester-methacrylic acid copolymer, styrene-alkyl acrylic acid ester-acrylic acid copolymer, styrene-methacrylic acid phenyl ester-methacrylic acid, Styrene-methacrylic acid cyclohexyl ester-methacrylic acid copolymer, styrene-styrenesulfonic acid copolymer, styrene-maleic acid copolymer, styrene-methacrylic acid copolymer, styrene-acrylic acid copolymer, vinylnaphthalene-maleic Examples include acid copolymers, vinyl naphthalene-methacrylic acid copolymers, vinyl naphthalene-acrylic acid copolymers, polystyrene, polyester, and polyvinyl alcohol.

  The dispersant of the present invention preferably has a weight average molecular weight of 2,000 to 60,000. In the dispersant of the present invention, the ratio of the amount added to the pigment is preferably in the range of 10% to 100%, more preferably 20% to 70%, and still more preferably 40% to 50%, based on mass. .

(Water-soluble organic solvent)
In the water-based ink of the ink jet recording system, the water-soluble organic solvent can be used for the purpose of an anti-drying agent, a wetting agent or a penetration accelerator.
An anti-drying agent is used for the purpose of preventing clogging due to drying of the ink-jet ink at the ink ejection port of the nozzle. As the anti-drying agent and wetting agent, a water-soluble organic solvent having a lower vapor pressure than water is preferable. .
In addition, a water-soluble organic solvent is preferably used as a penetration accelerator for the purpose of allowing ink jet ink to penetrate into paper better.

  Examples of water-soluble organic solvents include glycerin, 1,2,6-hexanetriol, trimethylolpropane, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, dipropylene glycol, 2-butene -1,4-diol, 2-ethyl-1,3-hexanediol, 2-methyl-2,4-pentanediol, 1,2-octanediol, 1,2-hexanediol, 1,2-pentanediol, Alkanediols (polyhydric alcohols) such as 4-methyl-1,2-pentanediol; glucose, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid, glucitol, maltose, cellobiose, lacto Sugars such as sucrose, trehalose, maltotriose; sugar alcohols; hyaluronic acids; so-called solid wetting agents such as ureas; alkyl alcohols having 1 to 4 carbon atoms such as ethanol, methanol, butanol, propanol, isopropanol; Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, ethylene glycol mono-iso-propyl ether, diethylene glycol mono -Iso-propyl ether, ethylene glycol mono-n-butyl ether, Lenglycol mono-t-butyl ether, diethylene glycol mono-t-butyl ether, 1-methyl-1-methoxybutanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-n-propyl Glycol ethers such as ether, propylene glycol mono-iso-propyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-iso-propyl ether; 2 -Pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, formamide, aceto Examples include amide, dimethyl sulfoxide, sorbit, sorbitan, acetin, diacetin, triacetin, sulfolane and the like, and one or more of these can be used.

  For the purpose of drying inhibitors and wetting agents, polyhydric alcohols are useful, such as glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-butanediol. 2,3-butanediol, 1,4-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, tetraethylene glycol, 1,6-hexanediol, 2-methyl-2, Examples include 4-pentanediol, polyethylene glycol, 1,2,4-butanetriol, 1,2,6-hexanetriol, and the like. These may be used individually by 1 type and may use 2 or more types together.

  For the purpose of the penetrant, a polyol compound is preferable. Examples of the aliphatic diol include 2-ethyl-2-methyl-1,3-propanediol, 3,3-dimethyl-1,2-butanediol, 2, 2-diethyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-dimethyl-2,4-pentanediol, 2,5-dimethyl-2,5-hexane Examples include diol, 5-hexene-1,2-diol, and 2-ethyl-1,3-hexanediol. Among these, preferred examples include 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol.

The water-soluble organic solvent used in the ink of the present invention may be used alone or in combination of two or more. The content of the water-soluble organic solvent is 1 to 60% by mass, preferably 5 to 40% by mass.
The amount of water added to the ink in the present invention is not particularly limited, but is preferably 10% by mass to 99% by mass, and more preferably 30% by mass to 80% by mass. More preferably, it is 50 mass% or more and 70 mass% or less.

(Resin fine particles)
The ink composition in the present invention contains at least one kind of resin fine particles. By including resin fine particles, the scratch resistance of an image formed can be improved.
Examples of the resin fine particles or polymer latex that can be used in the present invention include acrylic resins, vinyl acetate resins, styrene-butadiene resins, vinyl chloride resins, acrylic-styrene resins, butadiene resins, styrene resins, Cross-linked acrylic resins, cross-linked styrene resins, benzoguanamine resins, phenol resins, silicone resins, epoxy resins, urethane resins, paraffin resins, fluorine resins, and the like can be used. Preferred examples include acrylic resins, acrylic-styrene resins, styrene resins, cross-linked acrylic resins, and cross-linked styrene resins.

The weight average molecular weight of the resin fine particles is preferably 10,000 or more and 200,000 or less, more preferably 100,000 or more and 200,000 or less.
The average particle size of the resin fine particles is preferably in the range of 10 nm to 1 μm, more preferably in the range of 10 to 200 nm, still more preferably in the range of 20 to 100 nm, and particularly preferably in the range of 20 to 50 nm.

The content of the resin fine particles is preferably 0.5 to 20% by mass, more preferably 3 to 20% by mass, and further preferably 5 to 15% by mass with respect to the ink.
The glass transition temperature Tg of the resin fine particles is preferably 30 ° C. or higher, more preferably 40 ° C. or higher, and further preferably 50 ° C. or higher.
Further, the particle size distribution of the resin fine particles is not particularly limited, and may be any of those having a wide particle size distribution and those having a monodispersed particle size distribution. Further, two or more kinds of resin fine particles having a monodispersed particle size distribution may be mixed and used.

(Surfactant)
The ink in the present invention can contain a surfactant as necessary, and the surfactant can be used as a surface tension adjusting agent.
Examples of the surface tension adjusting agent include nonionic, cationic, anionic and betaine surfactants. The addition amount of the surface tension adjusting agent is preferably an amount for adjusting the surface tension of the ink of the present invention to 20 to 60 mN / m, more preferably 20 to 45 mN / m, in order to achieve good droplet ejection by inkjet. Preferably, the amount can be adjusted to 25 to 40 mN / m.
As the surfactant in the present invention, a compound having a structure having both a hydrophilic part and a hydrophobic part in the molecule can be used effectively. Anionic surfactants, cationic surfactants, amphoteric surfactants can be used. Any of the nonionic surfactants can be used. Furthermore, the above-mentioned polymer substance (polymer dispersing agent) can also be used as a surfactant.

  Specific examples of anionic surfactants include, for example, sodium dodecylbenzenesulfonate, sodium lauryl sulfate, sodium alkyldiphenyl ether disulfonate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate, sodium stearate, potassium oleate, sodium dioctyl Examples include sulfosuccinate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfate, sodium oleate, sodium t-octylphenoxyethoxypolyethoxyethyl sulfate, and the like. 1 type, or 2 or more types can be selected.

Specific examples of the nonionic surfactant include, for example, polyoxyethylene lauryl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene oleyl phenyl ether, polyoxyethylene nonyl phenyl ether, oxyethylene / oxypropylene block copolymer, t- Examples include octylphenoxyethyl polyethoxyethanol, nonylphenoxyethyl polyethoxyethanol, and the like, and one or more of these can be selected.
Examples of the cationic surfactant include tetraalkylammonium salts, alkylamine salts, benzalkonium salts, alkylpyridium salts, imidazolium salts, and the like. Specific examples thereof include dihydroxyethyl stearylamine and 2-heptadecenyl. -Hydroxyethyl imidazoline, lauryl dimethyl benzyl ammonium chloride, cetyl pyridinium chloride, stearamide methyl pyridium chloride and the like.
The content of the surfactant in the ink composition in the invention is not particularly limited, but is preferably 1% by mass or more, more preferably 1 to 10% by mass, and still more preferably 1 to 3% by mass. %.

(Other ingredients)
The ink composition in the present invention can contain various additives as other components as necessary.
Other additives include, for example, ultraviolet absorbers, anti-fading agents, anti-mold agents, pH adjusters, rust inhibitors, antioxidants, emulsion stabilizers, preservatives, antifoaming agents, viscosity modifiers, and dispersion stabilizers. Known additives such as agents and chelating agents are included.

  Examples of the UV absorber include benzophenone UV absorbers, benzotriazole UV absorbers, salicylate UV absorbers, cyanoacrylate UV absorbers, nickel complex salt UV absorbers, and the like.

  As the antifading agent, various organic and metal complex antifading agents can be used. Organic anti-fading agents include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, heterocycles, etc. Complex, zinc complex and the like.

  Antifungal agents include sodium dehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide, p-hydroxybenzoic acid ethyl ester, 1,2-benzisothiazolin-3-one, sodium sorbate, sodium pentachlorophenol, etc. Can be mentioned. These are preferably used in the ink in an amount of 0.02 to 1.00% by mass.

  The pH adjuster is not particularly limited as long as it can adjust the pH to a desired value without adversely affecting the recording ink to be prepared, and can be appropriately selected according to the purpose. Amines (eg, diethanolamine, triethanolamine, 2-amino-2-ethyl-1,3-propanediol, etc.), alkali metal hydroxides (eg, lithium hydroxide, sodium hydroxide, potassium hydroxide, etc.), Examples thereof include ammonium hydroxide (for example, ammonium hydroxide, quaternary ammonium hydroxide), phosphonium hydroxide, alkali metal carbonate, and the like.

  Examples of the rust inhibitor include acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

  Examples of the antioxidant include phenol antioxidants (including hindered phenol antioxidants), amine antioxidants, sulfur antioxidants, phosphorus antioxidants, and the like.

  Examples of the chelating agent include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uramil diacetate and the like.

<Ink physical properties>
The surface tension of the ink in the present invention is preferably 20 mN / m or more and 60 mN / m or less. More preferably, it is 20 mN or more and 45 mN / m or less, More preferably, it is 25 mN / m or more and 40 mN / m or less.
In addition, the viscosity at 20 ° C. of the ink in the present invention is preferably 1.2 mPa · s or more and 15.0 mPa · s or less, more preferably 2 mPa · s or more and less than 13 mPa · s, further preferably 2.5 mPa · s. · It is s or more and less than 10 mPa · s.

<Inkjet recording method>
As a preferred ink jet recording method for the present invention, a known image receiving material such as plain paper, resin-coated paper, for example, JP-A-8-169172, JP-A-8-27693, JP-A-2-276670, JP-A-7-276789, JP-A-9-323475, JP-A-62-238783, JP-A-10-153989, JP-A-10-217473, JP-A-10-235995 10-337947, 10-217597, 10-337947, etc. Form images on inkjet paper, film, electrophotographic co-paper, fabric, glass, metal, ceramics, etc. The method of doing can be mentioned. In addition, the description of paragraph numbers 0093 to 0105 in JP-A No. 2003-306623 can be applied as an ink jet recording method preferable for the present invention.

  In forming an image, a polymer latex compound may be used in combination for the purpose of giving glossiness or water resistance or improving weather resistance. The timing of applying the latex compound to the image receiving material may be before, after, or simultaneously with the application of the colorant, and therefore the addition location may be in the image receiving paper. It may be in ink or may be used as a liquid material of polymer latex alone. Specifically, the methods described in JP-A Nos. 2002-166638, 2002-121440, 2002-154201, 2002-144696, and 2002-080759 can be preferably used.

The image recording method of the present invention comprises:
First step: a step of attaching a pretreatment liquid containing a fluorosurfactant on a recording medium;
Second step: A step of applying a reaction liquid (a liquid composition for improving printability) containing a reactive agent that is brought into contact with the ink composition to form an aggregate on the recording medium to which the pretreatment liquid is applied; ,
Third step: a step of applying an ink composition containing a colorant, resin fine particles, a water-soluble organic solvent, and water onto the recording medium to which the pretreatment liquid is applied;
Is preferably included, and may be configured to include other steps as necessary.

(Other processes)
Other steps are not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include a drying removal step and a heat fixing step.
The drying and removing step (hereinafter sometimes simply referred to as “drying step”) is a method for drying and removing at least a part of the solvent contained in the pretreatment liquid, reaction liquid, ink composition and the like applied on the recording medium. If it is, there will be no restriction | limiting in particular, It can carry out by the method used normally, such as ventilation and a heating.

The drying removal step
(1) After the step of applying the pretreatment liquid and before the step of applying the reaction liquid.
(2) After the step of applying the reaction liquid and before the step of applying the ink composition.
(3) After the step of applying the ink composition.
It may be provided at any point in time. In the present invention, from the viewpoint of suppressing the occurrence of curl and cockle, it is preferably provided at least after the step (1) of applying the pretreatment liquid and before the step of applying the reaction liquid, and (2) It is more preferably provided after the step of applying the reaction liquid and before the step of applying the ink composition, and more preferably (3) provided after the step of applying the ink composition.
Moreover, it is preferable to provide a drying removal step after the step of applying the reaction liquid and the step of applying the ink composition from the viewpoint of image forming properties.

  The heat fixing step in the present invention is not particularly limited as long as the resin fine particles contained in the ink composition used in the ink jet recording method can be melt-fixed, and is appropriately selected depending on the purpose. Can do.

The formation of an image by the ink jet recording method of the present invention is performed at least by applying a pretreatment liquid on a recording medium and applying a reaction liquid and an ink composition to a region to which the pretreatment liquid is applied. By applying the pretreatment liquid to the recording medium prior to the application of the reaction liquid and the ink composition, the occurrence of curling and cockle can be effectively suppressed.
The ink jet recording method of the present invention preferably further includes a drying removal step after the pretreatment liquid application step and before the reaction liquid application step and the ink application step.
This is because the pretreatment liquid in the present invention is considered to enhance the effect by, for example, enhancing the water repellency of the applied region and delaying the penetration of the solvent contained in the reaction liquid and the ink composition in the paper surface direction. is there.

<Recording medium>
The recording medium that can be used in the present invention is not particularly limited, and general printing paper mainly composed of cellulose, such as so-called high-quality paper, coated paper, and art paper, which is used for general offset printing and the like can be used. These general printing papers mainly composed of cellulose are curled by a solvent of water-based ink (water, hydrophilic organic solvent, etc.) in ordinary aqueous ink-jet image formation. According to the image forming method of the invention, it is possible to form an image while suppressing the occurrence of curling.

  As a recording medium used in the image recording method of the present invention, a commercially available one can be appropriately selected and used. For example, high-quality paper (A) such as Oji Paper's “OK Prince Fine”, Nippon Paper's “Shiorai”, and Nippon Paper's “New NPI Fine”, Oji Paper's “OK Everlight Coat” and Nippon Paper Lightly coated paper (A3) such as “Aurora S” and other fine-coated paper, Oji Paper “OK Coat L” and Nippon Paper “Aurora L”, Oji Paper “OK Top Coat +” and Nippon Paper “ Use coated paper (A2, B2) such as "Aurora Coat", art paper (A1) such as "OK Kanfuji +" made by Oji Paper and "Special Rishi Art" made by Mitsubishi Paper, and various types of photographic paper for inkjet recording Can do.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, “part” and “%” are based on mass, and “polymerization degree” represents “average polymerization degree”.

<Preparation of ink>
(1) Preparation of cyan pigment ink C (Preparation of pigment dispersion)
As a colorant, 10 g of cyanine blue A-22 (PB15: 3, manufactured by Dainichi Seika Co., Ltd.), 10.0 g of low molecular weight dispersing agent 2-1, 4.0 g of glycerin, and 26 g of ion-exchanged water are mixed with stirring. A crude dispersion was prepared. Next, using an ultrasonic irradiation device (Vibra-cell VC-750 manufactured by SONICS, taper microchip: φ5 mm, Amplitude: 30%), the coarse dispersion was intermittently irradiated with ultrasonic waves (irradiation 0.5 seconds, The pigment was further dispersed by irradiation for 2 hours at a rest of 1.0 second to obtain a 20% pigment dispersion. The low molecular weight dispersant 2-1 is a compound represented by the following chemical formula.

Separately from the above, the following compounds were weighed and then mixed by stirring to prepare a mixed solution I.
(Mixed liquid I)
・ Glycerin (water-soluble organic solvent) 5.0 g
・ Diethylene glycol (water-soluble organic solvent) 10.0 g
・ Orphine E1010 (manufactured by Nissin Chemical Industry) 1.0g
・ Ion exchange water 11.0g

This mixed liquid I was slowly added dropwise to 23.0 g of a stirred 44% SBR dispersion (resin fine particles: acrylic acid 3%, Tg (glass transition temperature) 30 ° C.) 30 ° C., and mixed to prepare mixed liquid II. did.
The obtained mixed liquid II was stirred and mixed while slowly dropping into the 20% pigment dispersion obtained above to prepare 100 g of cyan pigment ink C (cyan ink) as an ink composition.
When the pH of the pigment ink C was measured using a pH meter WM-50EG manufactured by Toa DKK Co., Ltd., the pH value was 8.7.

(2) Preparation of Magenta Pigment Ink M In preparation of pigment ink C, instead of cyanine blue A-22 used as a pigment, Chrophtal Jet Magenta DMQ (PR-122, manufactured by Ciba Specialty Chemicals) was used. Except for the above, a magenta pigment ink M (magenta ink) was produced in the same manner as in the preparation of the pigment ink C described above.
When the pH of the pigment ink M was measured with a pH meter WM-50EG manufactured by Toa DKK Corporation, the pH value was 8.5.

(3) Preparation of Yellow Pigment Ink Y In preparation of Pigment Ink C, Irgalite Yellow GS (PY74, manufactured by Ciba Specialty Chemicals) was used instead of cyanine blue A-22 used as a pigment. A yellow pigment ink Y (yellow ink) was prepared in the same manner as in the preparation of the pigment ink C described above except for the pigment.
When the pH of the pigment ink Y was measured with a pH meter WM-50EG manufactured by Toa DKK Co., Ltd., the pH value was 8.4.

(4) Preparation of black pigment ink K The pigment ink described above, except that the pigment dispersion CAB-O-JETTM_200 (carbon black, manufactured by CABOT) was used in place of the pigment dispersion used in the preparation of pigment ink C. A black black pigment ink K (black ink) was prepared in the same manner as in the preparation of C.
When the pH of the pigment ink K was measured with a pH meter WM-50EG manufactured by Toa DKK Co., Ltd., the pH value was 8.8.

<Preparation of reaction solution>
(Reaction solution 1)
The following materials were mixed to prepare a reaction solution 1.
・ Phosphoric acid 10g
・ Diethylene glycol monoethyl ether 20g
・ Orphine E1010 (manufactured by Nissin Chemical Industry) 1g
・ Ion-exchanged water 69g
When the pH of the reaction solution 1 thus prepared was measured with a pH meter WM-50EG manufactured by Toa DKK Co., Ltd., the pH value was 1.0.

(Reaction solution 2)
The following materials were mixed to prepare reaction solution 2.
・ Calcium nitrate 10g
・ Diethylene glycol monoethyl ether 17g
・ Orphine E1010 (manufactured by Nissin Chemical Industry) 1g
・ Ion-exchange water 72g

(Reaction solution 3)
The following materials were mixed to prepare a reaction solution 3.
・ Phosphoric acid 10g
・ Diethylene glycol monoethyl ether 20g
・ Orphine E1010 (Nissin Chemical Industry) 5g
・ Ion exchange water 65g
It was 1.0 when the pH value of the produced reaction liquid 3 was measured.

<Preparation of pretreatment liquid>
Materials were mixed to prepare pretreatment liquid 1 to pretreatment liquid 7 so as to have the following composition.
(Pretreatment liquid 1)
・ Megafuck F-472SF: 1.8%
(Fluorosurfactant, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Ion-exchanged water: 78.2%
・ Diethylene glycol monoethyl ether: 20.0%

(Pretreatment liquid 2)
・ Megafuck F-482: 0.8%
(Fluorosurfactant, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Methyl ethyl ketone: 99.2%

(Pretreatment liquid 3)
・ Furgent FTX-730FL: 2.0%
(Fluorosurfactant, manufactured by Neos Co., Ltd.)
・ Methyl ethyl ketone: 98.0%

(Pretreatment liquid 4)
・ Zonyl UR: 1.0%
(Fluorosurfactant, manufactured by EI Dupont Dom Nemours & Company)
・ Ion-exchanged water: 79.0%
・ Diethylene glycol monoethyl ether: 20.0%

(Pretreatment liquid 5)
・ Zonyl FSP: 1.0%
(Fluorosurfactant, manufactured by EI Dupont Dom Nemours & Company)
・ Ion-exchanged water: 79.0%
・ Diethylene glycol monoethyl ether: 20.0%

(Pretreatment liquid 6)
・ KF-355A: 1.0%
(Silicon surfactant (polyether-modified polydimethylsiloxane), manufactured by Shin-Etsu Chemical Co., Ltd.)
・ Ion-exchanged water: 79.0%
・ Diethylene glycol monoethyl ether: 20.0%

(Pretreatment liquid 7)
・ Surfinol 465: 1.5%
(Acetylene surfactant, manufactured by Shin-Etsu Chemical Co., Ltd.)
・ Ion exchange water: 78.5%
・ Diethylene glycol monoethyl ether: 20.0%

<Image recording>
A4 size mat-coated paper (manufactured by Nippon Paper Industries Co., Ltd., trade name: Ulite) was used as the recording medium, and the surface was coated with a bar coater so that the coating amount (applied amount) of the surfactant was 0.07 g / m ^2. Treatment liquids 1 to 7 were applied, respectively. In Example 7, the coating amount of the surfactant is 0.3 g / m ² , 0.7 g / m ² in Example 8, 0.003 g / m ² in Example 9, and In Example 10, each pretreatment liquid was applied so as to be 0.007 g / m ² .
Subsequently, it was dried at 60 ° C. for 5 seconds to produce a recording medium provided with the pretreatment liquid.
An image was recorded under the following image recording conditions using the obtained recording medium provided with the surfactant in combination with the reaction liquid shown in Table 1. In addition, as a recording medium in Comparative Examples 1 and 2, a recording medium to which no pretreatment liquid was applied was used.

<Dropping method>
As the ink composition, the cyan pigment ink C, the magenta pigment ink M, the yellow pigment ink Y, and the black pigment ink K obtained above were used, and the reaction liquid shown in Table 1 was used. Single pass image formation was performed.

-Reaction liquid application process-
Head: 600 dpi / 20 inch width piezo full line head Discharge droplet volume: binary recording of 0, 4.0 pL Drive frequency: 15 kHz (recording medium conveyance speed 635 mm / sec)
Drawing pattern: In the ink application step, a reaction liquid was applied in advance by applying a pattern corresponding to a position where at least one color of ink was applied.

Next, the recording medium provided with the reaction liquid was dried under the following conditions.
-Drying conditions for reaction liquid (fan drying)-
Wind speed: 15m / s
Temperature: The recording medium was heated from the back side of the recording surface with a contact type flat heater so that the surface temperature of the recording medium was 60 ° C.
Air blowing area: 450 mm (drying time 0.7 seconds)

-Ink application process-
The ink composition was applied on the recording medium to which the reaction solution was applied under the following conditions.
Head: 1,200 dpi / 20 inch wide piezo full line heads were arranged for four colors.
Discharge droplet volume: 4-value recording of 0, 2.0, 3.5, 4.0 pL was performed.
Drive frequency: 30 kHz (recording medium conveyance speed 635 mm / sec)

Next, the recording medium provided with ink was dried under the following conditions.
--Drying conditions for ink (air drying)-
Wind speed: 15m / s
Temperature: The recording medium was heated from the back side of the recording surface with a contact type flat heater so that the surface temperature of the recording medium was 60 ° C.
Air blowing area: 640 mm (drying time 1 second)

Next, heat fixing treatment was performed under the following conditions.
--Fixing--
Silicone rubber roller (hardness 50 °, nip width 5mm)
Roller temperature: 90 ° C
Pressure: 0.8 MPa

<Evaluation>
-Contact angle of water-
The contact angle of the recording medium to which the pretreatment liquid was applied was measured as the contact angle when 0.30 seconds had elapsed after dropping 1.0 μl of water using DropMaster DM700 (manufactured by Kyowa Interface Science Co., Ltd.). . The measurement results are shown in Table 1.

-Bleeding test after printing-
The gray scale and the character image printed for evaluation were visually evaluated according to the following evaluation criteria. The evaluation results are shown in Table 1.
~Evaluation criteria~
A: Image bleeding and color mixing were not observed, and the characters “hawk” of 4 pt or less could be resolved.
B: Image bleeding and color mixing were not observed, and 5 pt “hawk” characters could be resolved.
C: Image blurring and color mixing were often observed, and the practicality was low.
D: Image bleeding and color mixture were severely observed, and the practicality was extremely low.

-Curl evaluation-
Image recording was performed under the following conditions along the image recording process procedure. For the recording medium, ink was ejected onto a test piece cut to a size of 50 mm × 5 mm in the MD and CD directions so that the ink became 10 g / m ² . After image formation, the JAPAN TAPPI paper pulp test method no. Based on the curl curvature measuring method prescribed | regulated to 15-2: 2000, the curl degree after 23 degreeC and 50% RH and 8 hours was measured, and it evaluated according to the following evaluation criteria. The evaluation results are shown in Table 1.
~Evaluation criteria~
A: The curl degree was less than 10.
B: The curl degree was 10 or more and less than 20.
C: Curling degree was 20 or more and less than 30.
D: The curl degree was 30 or more.

-Cuckle evaluation-
A 2cm x 2cm single color 100% solid image is printed on the center of the recording medium on a recording medium cut to postcard size, and the maximum height of the corrugation generated immediately after printing is measured with a laser displacement meter (manufactured by Keyence Corporation). And evaluated according to the following evaluation criteria. The evaluation results are shown in Table 1.
~Evaluation criteria~
A: 1 mm or more and less than 2 mm.
B: It was 2 mm or more and less than 3 mm.
C: It was 3 mm or more.

-Evaluation of scratch resistance-
About the recording medium to which the ink composition was applied, immediately after printing, the solid printed portion of 2 cm square was rubbed with a finger, and the degree of ink transfer to the blank paper portion was visually observed. The evaluation criteria for scratch resistance are as follows. The evaluation results are shown in Table 1.

~Evaluation criteria~
A: There was no transfer of ink.
B: The transfer of ink was hardly noticeable.
C: Some transfer of ink was observed.
D: Ink transfer was bad.

From Table 1, it can be seen that according to the image recording method of the present invention, the occurrence of curling and cockle is suppressed, and an image with less blur can be formed.
Furthermore, it can be seen that the image recording method of the present invention can form an image having excellent scratch resistance.

Claims (5)

An image recording method for forming an image using a colored ink composition,
A pretreatment liquid application step of applying a pretreatment liquid containing a fluorosurfactant on the recording medium;
A reaction liquid applying step of applying a reaction liquid containing a reactive agent that is brought into contact with the ink composition to form an aggregate on the recording medium to which the pretreatment liquid is applied;
An image recording method comprising: an ink application step of applying an ink composition comprising a colorant, resin fine particles, a water-soluble organic solvent, and water on the recording medium to which the pretreatment liquid has been applied.   2. The image recording method according to claim 1, wherein an area of the recording medium to which the pretreatment liquid is applied has a contact angle with water of 85 degrees or more. 3. The image recording according to claim 1, wherein in the pretreatment liquid application step, the application amount of the fluorosurfactant is 0.005 g / m ^{2 to} 0.5 g / m ^2. Method.   The image recording method according to claim 1, further comprising a drying removal step after the ink application step and the reaction liquid application step.   The image recording method according to claim 1, wherein the reactant is at least one of a polyvalent metal salt and an acidic substance.