JP2017132093A - Inkjet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet-recording method, while suppressing curl of an inkjet-recorded matter, capable of suppressing image peel-off, high color development, and sweeping, and capable of improving liquid-contacting-to-member properties of a reaction liquid.SOLUTION: An inkjet recording method includes: contacting a fixing member to an image formed by applying a first ink on a recording medium, and thereafter applying a second ink so as to overlap with a region on which the first ink is applied; and subjecting to heating and compressing treatment where the first ink contains at least a zirconium compound, and amino acid, the second ink contains at least a pigment, a resin fine particle having a minimum film-forming temperature higher than a heat treatment temperature, and an anionic water-soluble resin, and a mass ratio of the resin fine particle to the anionic water-soluble resin is not less than 2.5 and not greater than 7.5.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an ink jet recording method.

  Conventionally, in the business field, it has been mainstream to use an electrophotographic recording apparatus that can output an image having high quality and high fastness (abrasion resistance, marker resistance, etc.) at a high speed. However, in recent years, the movement to shift to an ink jet recording apparatus has been accelerated from the viewpoint of low running cost and the like.

  Since the ink used in the ink jet recording apparatus contains moisture and a solvent, there is a problem that the ink jet recorded material is easily curled. As one of the methods for suppressing the occurrence of curling, the fixing member is brought into contact with the surface on which the image is formed with ink, and the heating and pressurizing treatment is performed to promote the evaporation of moisture and solvent in the ink. There is a method for fixing the image.

  However, this method sometimes causes image peeling (a phenomenon in which the image is offset to the fixing member).

  In order to solve such a problem, Patent Document 1 proposes an image forming method and an image forming apparatus that suppress the occurrence of fixing offset by using a specific ink. Specifically, in Patent Document 1, in order to suppress fixing offset, the minimum film-forming temperature of an aqueous dispersion of resin particles in ink and the minimum composition of a mixed liquid of resin particles, a water-soluble organic solvent and water are used. Ink that satisfies a specific relationship between the film temperature and the temperature of the recording medium at the time of fixing is used.

JP 2010-208108 A

  However, Patent Document 1 shows an example in which image peeling is suppressed by making the specific relationship between the minimum film forming temperature of the resin particles and the temperature of the recording medium at the time of heating and pressure fixing, In addition to insufficient color developability, it was difficult to say that the level of image peeling was sufficient. In addition, in order to form a high-quality image, suppression of sweeping and improvement of the liquid contact property of the reaction liquid have been demanded.

  Therefore, an object of the present invention is to suppress curling of an ink-jet recorded material, and also to suppress image peeling, high color development, suppression of sweeping, and improvement of the liquid contact property of a reaction liquid. Another object of the present invention is to provide an ink jet recording method that can be used.

  Said subject is achieved by the following this invention. That is, the ink jet recording method according to the present invention is formed by applying the first ink on the recording medium and then applying the second ink so as to partially overlap the region to which the first ink is applied. An ink jet recording method in which a fixing member is brought into contact with the obtained image and subjected to heating and pressure treatment, wherein the first ink contains at least a zirconium compound and an amino acid, and the second ink contains at least a pigment. And a resin fine particle having a minimum film-forming temperature higher than the heat treatment temperature, and an anionic water-soluble resin, and a mass ratio of the resin fine particle to the anionic water-soluble resin (the resin fine particle / the anionic water-soluble resin). ) Is 2.5 or more and 7.5 or less.

  According to the present invention, an ink jet that can suppress curling of an ink-jet recorded material, and can also achieve suppression of image peeling, high color developability, suppression of sweeping, and improvement of member wettability of a reaction liquid. It is possible to provide a recording method.

It is a fragmentary sectional view of the ink jet recording device which has a means which coats the 1st ink with a roller in the ink jet recording method concerning the present invention. It is a figure which shows the heating-pressing fixing apparatus of a film heating system.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

  First, the background to the present invention will be described. In order to obtain a recorded material comparable to the electrophotographic system, the present inventors have repeatedly studied to solve the curl that is likely to occur in the inkjet-based recorded material. As a result, it has been found that it is effective to use a contact-type heat and pressure fixing that has high thermal efficiency and is compatible with high-speed printing.

  However, it has also been found that image peeling tends to occur because the fixing member is brought into contact with the surface of the recorded material immediately after ink is applied to the recording medium.

  In response to this problem, the present inventors examined a reaction liquid (first ink) containing a zirconium compound. As a result, it was confirmed that image peeling was further suppressed as compared with the case where an ordinary polyvalent metal compound such as a calcium compound or an acid buffer compound such as citric acid was used.

  The present inventors consider the reason why such characteristics are obtained as follows.

  First, the cause of image peeling was examined. After the liquid contained in the reaction liquid (first ink) and the ink (second ink) once penetrated into the paper surface, The phenomenon of seeping into the recess was confirmed. This phenomenon is a force that lifts the ink agglomerated layer from the surface of the paper, and is considered to contribute to image peeling depending on the balance with the force that the ink agglomerated layer tries to adhere to the fixing roller (fixing member). It was.

  On the other hand, when a reaction liquid containing a zirconium compound is applied to paper (recording medium) and then an ink that is particularly alkaline is applied, the zirconium compound in the reaction liquid gels due to the shock of the pH of the ink, and the paper and ink aggregation layer It acts like a glue that binds. As a result, it was estimated that image peeling was suppressed.

  On the other hand, the pH of aqueous solutions of many zirconium-based compounds is very low, and is approximately less than pH 2 depending on the concentration. Therefore, metal parts such as tanks that contain ink, ink jet recording heads or application rollers for applying ink to recording media, heat and pressure fixing devices, and staples for fastening recorded materials are mainly corroded. There is a possibility. If this pH is raised with a normal basic substance such as potassium hydroxide, gelation of the zirconium compound will occur at that point, and the use will be lost.

  As a result of the study by the present inventors, in order to increase the pH without gelling the zirconium compound and maintain the reactivity with ink and the effect of suppressing image peeling, amino acids, particularly amino acids having a high isoelectric point are used. It was found that using a small amount was effective. Of the amino acids, basic amino acids were particularly effective. The mechanism by which an amino acid does not cause gelation is not clear, but it is presumed that the carboxy group of the amino acid can be coordinated and substituted with a part of a hydroxy crosslinked polymer composed of a plurality of zirconium atoms. It has also been confirmed that when the amount of amino acid used for pH increase is excessively large, the gel formed tends to become brittle.

  Here, as a result of an analysis on the fact that the suppression of image peeling was insufficient even when using only a zirconium-based compound or using an amino acid in combination therewith, the film strength of the ink aggregation layer was insufficient. Was estimated as a factor. That is, although the binding force between the paper and the ink aggregating layer has been improved, it has been found that suppression of image peeling becomes insufficient due to insufficient strength of the ink aggregating layer itself.

  The reason why the strength of the ink agglomerated layer was insufficient was considered to be that the anionic water-soluble resin in the ink caused volume shrinkage when it contacted the reaction solution, and the ink agglomerated layer was cracked. . This phenomenon is remarkable when the ratio of the anionic water-soluble resin is large as the resin component in the ink. In the reaction liquid and ink described in Patent Document 1, the reason for the insufficient suppression of image peeling is as follows. Presumed.

  The present inventors have come up with the idea of using resin fine particles as a resin system having a small volume shrinkage, and proceeded with a study to replace water-soluble resins. If a large amount of resin fine particles is used, the water content can be reduced while suppressing the viscosity of the ink, which should be advantageous for curling. However, it has been found that if the proportion of the resin fine particles increases too much, image peeling tends to occur. This is presumably because the strength of the ink agglomerated layer is insufficient due to the lack of an anionic water-soluble resin that holds the resin fine particles together.

  On the other hand, although studies have been made to improve the film strength by using resin fine particles having a low minimum film-forming temperature, which are easily melted by heat and pressure fixing, they have not been fully solved. This is related to the sweeping phenomenon described later, but when the proportion of resin fine particles with low reactivity to the reaction liquid is large, a large amount of moisture / liquid remains around the resin fine particles, so that contact between the grain boundaries occurs. It is estimated that this is because the melting of the resin fine particles is suppressed.

  From the above, in order to sufficiently suppress image peeling, the present inventors use a zirconium-based compound in the reaction liquid and contain resin fine particles and an anionic water-soluble resin in an appropriate ratio in the ink. I found that it was very important. Specifically, it is important that the mass ratio of the resin fine particles to the anionic water-soluble resin (the resin fine particles / the anionic water-soluble resin) is 2.5 to 7.5. They found out.

  Furthermore, the present inventors paid attention to a decrease in color developability as a problem other than image peeling due to heat and pressure fixing.

  It is presumed that the reason why the color developability is lowered by the heat and pressure fixing is that the ink aggregation layer is crushed and the voids are reduced by fixing. For example, in the case of a black ink, an appropriate gap exists in the ink aggregating layer before fixing, so that the apparent refractive index of the layer is lowered and reflected light is reduced. This is thought to be because it is difficult to obtain color developability due to the decrease.

As a result of investigations by the present inventors on the problem, as a result of using resin fine particles having a minimum film forming temperature higher than the heating temperature in heat and pressure fixing, the color developability before fixing is greatly improved. In addition to this, it was found that a decrease in color developability after fixing was also suppressed. The reason for this is that by using such resin fine particles, the shape of the resin fine particles of the resin fine particles can be maintained even after heat and pressure fixing, and the following effects (1) to (3) can be obtained. The present inventors speculate.
(1) A sealing effect that suppresses sedimentation of the ink aggregation layer (pigment) into the paper surface.
(2) The effect of reducing the apparent refractive index of the ink aggregation layer (remarkable with black ink).
(3) Bronze reduction effect by suppressing regular reflection light on the outermost surface of the ink aggregation layer.

  However, it has been found that, while the color developability is improved, the use of the resin fine particles having such a high minimum film-forming temperature tends to cause sweeping. The reason for this was presumed that because the resin fine particles do not melt, the viscosity of the ink agglomerated layer does not increase at the time of fixing, and is pushed out under pressure. On the other hand, the use of resin fine particles having a minimum film-forming temperature lower than the heating temperature was also examined. However, although the sweeping was slightly improved, the color developing property was also reduced accordingly.

  Therefore, as a result of further investigations by the present inventors, by using together resin fine particles having a minimum film-forming temperature higher than the heat treatment temperature and an anionic water-soluble resin, coloring is suppressed while suppressing sweeping. I discovered that sex can be maintained.

  The reason why such characteristics can be obtained is that, with regard to suppression of sweeping, the combined use of an anionic water-soluble resin causes a sudden increase in viscosity at the time of contact with the reaction liquid, and solid-liquid separation proceeds rapidly. Thus, it is estimated that the penetration of the liquid component into the paper is promoted. In addition, it is estimated that the color developability is maintained because the precipitation of the ink aggregation layer (pigment) in the paper surface is suppressed by increasing the reactivity with the reaction liquid, and the decrease in the resin fine particles can be compensated. .

  As a result of investigation, in order to achieve both suppression of sweeping and high color development, it is very important to contain resin fine particles and an anionic water-soluble resin in an appropriate ratio, as well as suppression of image peeling. I found out.

  Through the above examination, the present inventors have developed an ink jet recording method capable of obtaining a recorded matter that can suppress image peeling even when curling of the ink jet recorded matter is suppressed and printing is performed at high speed. It came to invent.

<First ink>
[Zirconium compound]
The following are mentioned as a zirconium compound contained in the 1st ink concerning this invention. Specific examples include zirconium oxynitrate, zirconium oxychloride, zirconium oxyacetate, basic zirconium chloride, and zirconium oxysulfate. Among these, those having high gel-forming ability and excellent in suppression of image peeling include zirconium oxynitrate, zirconium oxychloride, zirconium oxyacetate, and basic zirconium chloride. Furthermore, zirconium oxynitrate, zirconium oxychloride, and basic zirconium chloride are particularly preferred in that no odor peculiar to acetic acid is generated when fixing by heating and pressing.

  Specifically, the following compounds can be used as these zirconium compounds, but the present invention is not limited thereto. Examples thereof include Zircosol ZN (zirconium oxynitrate), Zircosol ZC-20 (zirconium oxychloride), and Zircosol ZC-2 (basic zirconium chloride) which are commercially available from Daiichi Rare Element Chemical Co., Ltd.

  The content (mass%) of the zirconium compound is a mass converted to a zirconium atom, and is preferably 0.1 mass% or more and 30.0 mass% or less based on the total mass of the first ink. Furthermore, it is preferably 1.0% by mass or more and 20.0% by mass or less, and particularly preferably 3.0% by mass or more and 15.0% by mass or less. When the content of the zirconium compound is within the above range, image peeling can be further suppressed.

[amino acid]
The following are mentioned as an amino acid contained in the 1st ink concerning this invention. Specific examples include alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine and the like. .

  Among these, by using an amino acid having an isoelectric point of 5.5 or more, the pH of the first ink can be increased with a small amount of amino acid, which is compared with the case of using an amino acid having a low isoelectric point. Therefore, it is preferable because suppression of image peeling is better. Specific examples include alanine, arginine, glutamine, glycine, histidine, isoleucine, leucine lysine, methionine, proline, serine, threonine, tryptophan, tyrosine, and valine. Furthermore, among these amino acids, arginine and histidine are particularly preferable.

  The content (mass%) of the amino acid can be appropriately adjusted depending on the type and content of the zirconium compound and the type of amino acid. Specifically, the first ink is preferably adjusted so that the pH at 25 ° C. is 2.5 or more and 4.5 or less.

  When the pH of the first ink at 25 ° C. is within the above range, the liquid contact property and the color developability can be improved.

[Other polyvalent metal compounds]
The first ink according to the present invention can contain other polyvalent metal compounds in addition to the zirconium compound for the purpose of assisting the color development of the image and other performances. Specifically, for example, polyvalent metal cations such as Ca ²⁺ , Cu ²⁺ , Ni ²⁺ , Mg ²⁺ , Zn ²⁺ , Sr ²⁺ , Ba ²⁺ , Al ³⁺ , Fe ³⁺ , Cr ³⁺ , Y ³⁺ , and these It is a metal salt composed of an anion that binds to an ion, and is soluble in water.

<Second ink>
[Pigment dispersion]
Examples of pigments that can be used in the ink according to the present invention include pigments such as carbon black and organic pigments.

  For example, carbon black such as furnace black, lamp black, acetylene black, and channel black can be used as the carbon black. Specifically, for example, Raven 1170, Rayvan 1190ULTRA-II, Rayvan 1200, Rayvan 1250, Rayvan 1255, Rayvan 1500, Rayvan 2000, Rayvan 3500, Rayvan 5000, Rayvan 5250, Rayvan 5750, Rayvan 7000 (or more, Columbia), Mogul L (manufactured by Cablack), Black Pearls L, Legal 330R, Legal 400R, Legal 660R, Monarch 700, Monak 800, Monak 880, Monak 900, Monak 1000, Monak 1100, Monak 1300, Monak 1400, Valcan XC-72R (above, Cabot Color Black FW1, Color Black FW2, Color Black FW2V, Color Black FW18, Color Black FW200, Color Black S150, Color Black S160, Color Black S170, Printex 35, Printex U, Pudding Tex V, Printex 140U, Printex 140V, Special Black 4, Special Black 4A, Special Black 5 (above, manufactured by Degussa), No. 25, no. 33, no. 40, no. 47, no. 52, no. 900, no. 2300, MCF-88, MA7, MA8, MA100, MA600 (manufactured by Mitsubishi Chemical Corporation) and the like can be used. Of course, the present invention is not limited to these, and a conventionally known carbon black can also be used. Further, magnetic fine particles such as magnetite and ferrite, titanium black and the like may be used as the black pigment.

  As the organic pigment, for example, the following can be used. Specific examples include insoluble azo pigments such as toluidine red, toluidine maroon, Hansa yellow, benzidine yellow, and pyrazolone red. Further, soluble azo pigments such as ritole red, helio bordeaux, pigment scarlet, and permanent red 2B can be mentioned. Moreover, derivatives from vat dyes such as alizarin, indanthrone, thioindigo maroon and the like can be mentioned. Further, phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green, quinacridone pigments such as quinacridone red and quinacridone magenta, and perylene pigments such as perylene red and perylene scarlet can be used. Examples thereof include isoindolinone pigments such as isoindolinone yellow and isoindolinone orange, and imidazolone pigments such as benzimidazolone yellow, benzimidazolone orange and benzimidazolone red. Further, pyranthrone pigments such as pyranthrone red and pyranthrone orange, indigo pigments, condensed azo pigments, and thioindigo pigments may be mentioned. Further, examples include flavanthrone yellow, acylamide yellow, quinophthalone yellow, nickel azo yellow, copper azomethine yellow, perinone orange, anthrone orange, dianthraquinonyl red, dioxazine violet, and the like.

  Examples of the pigment dispersion method include a resin dispersion pigment using a resin as a dispersant, and a self-dispersion pigment in which a hydrophilic group is bonded to the surface of pigment particles. Moreover, a resin-bonded pigment in which an organic group containing a polymer is chemically bonded to the surface of the pigment particle, a microcapsule pigment in which the surface of the pigment particle is coated with a resin, and the like. Of course, pigments having different dispersion methods may be used in combination. Among these, a self-dispersing pigment in which an anionic group is bonded directly to the surface of the pigment particle or through another atomic group, or a resin as a dispersant is physically adsorbed on the surface of the pigment particle, and this resin is used. It is particularly preferable to use a resin-dispersed pigment that disperses pigment particles by the action of.

  The pigment content (mass%) may be appropriately selected so as to have excellent ink jet discharge characteristics when used for ink jet recording and to have a desired color tone and density. For example, it is preferably 0.1% by mass to 15.0% by mass based on the total mass of the second ink.

[Resin fine particles]
In the present invention, “resin fine particles” mean polymer particles present in a dispersed state in a solvent such as water.

  The resin fine particles were obtained, for example, by emulsion polymerization of monomers such as α, β-unsaturated carboxylic acid and its derivatives (meth) acrylic acid alkyl ester and (meth) acrylic acid alkylamide. Examples thereof include acryl-acrylic resin particles obtained by emulsion polymerization of acrylic resin particles, (meth) acrylic acid alkyl ester, (meth) acrylic acid alkylamide, and the like and a styrene monomer. Also obtained by emulsion polymerization around the core-shell type resin fine particles having different resin composition between the core part and the shell part constituting the resin particles, and acrylic resin prepared in advance for particle control as seed particles. Particles may be used.

  The monomer constituting the resin fine particles is not particularly limited, and examples thereof include hydrophobic resins such as acrylic resins, vinyl acetate resins, butadiene resins, and styrene resins. Specific examples include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, decyl acrylate, dodecyl acrylate, octadecyl Acrylate esters such as acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, glycidyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl Methacrylates such as methacrylate, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, glycidyl methacrylate, and vinyl esters such as vinyl acetate; vinylcyan such as acrylonitrile and methacrylonitrile Compounds; halogenated monomers such as vinylidene chloride and vinyl chloride; aromatic vinyl monomers such as styrene, α-methylstyrene, vinyltoluene, 4-t-butylstyrene, chlorostyrene, vinylanisole, vinylnaphthalene Olefins such as ethylene and propylene; dienes such as butadiene and chloroprene; vinyl ethers, vinyl ketones, vinyl pyrrolidone and the like Nyl monomers; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid and maleic acid; acrylamides such as acrylamide, methacrylamide and N, N′-dimethylacrylamide; 2-hydroxyethyl acrylate, Hydroxyl group-containing monomers such as 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate and 2-hydroxypropyl methacrylate; Compounds having an ethylene oxide group such as methoxypolyethylene glycol (meth) acrylate and polyethylene glycol (meth) acrylate These may be used alone or in combination of two or more.

  When the resin fine particles of the present invention are prepared by a conventionally known emulsion polymerization method, polymerization is carried out in an aqueous medium, if necessary, in the presence of an emulsifier, a polymerization initiator, a chain transfer agent, a chelating agent, a pH adjuster and the like. What is necessary is just to carry out the polymerization reaction of the ionic monobodies.

  The minimum film-forming temperature of the resin fine particles according to the present invention is measured according to JISK6828-2: 2003 (synthetic resin emulsion part 2: how to determine the whitening temperature and the minimum film-forming temperature). Specifically, on a simple film-forming temperature device (manufactured by Imoto Seisakusho), an aqueous dispersion in which resin fine particles are dispersed is applied with a 0.3 mm applicator and allowed to dry for 30 minutes, and the coated surface is coated with a glass rod. When tracing, the temperature at which scratches occurred on the coated surface was determined as the minimum film-forming temperature. In the present invention, the molten state of the resin after the liquid component is removed from the paper surface is important. Therefore, the minimum film-forming temperature of the resin fine particles in the present invention is not a result of measurement in an ink form, but needs to be measured in a state of an aqueous dispersion in which resin fine particles are dispersed in water in which a solvent or the like is not mixed. .

  The minimum film-forming temperature of the resin fine particles according to the present invention is preferably higher than the heat treatment temperature, and in particular, it is higher than the heat treatment temperature by 20 ° C. or higher so that high color development can be further maintained after heat and pressure fixing. Is preferable.

  The content (% by mass) of the resin fine particles is preferably 4.0% by mass or more and 20.0% by mass or less based on the total mass of the second ink. When the content of the resin fine particles is within the above range, it is possible to further improve the color developability and the occurrence of curling while stabilizing ink ejection.

[Anionic water-soluble resin]
In the present invention, the water-soluble resin contained in the second ink is an alkali-soluble resin having an anionic dissociation group from the viewpoint of high reactivity with the first ink. It is preferable that

  In the present invention, the “anionic water-soluble resin” refers to a resin aqueous solution (resin solid content of 10%) neutralized with potassium hydroxide corresponding to the acid value of the resin, and is volume-averaged by the following method. The particle size is not substantially measured. The volume average particle diameter was measured using a SetZero: 30 solution of a resin aqueous solution (resin solid content 10%) diluted with pure water 10 times (volume basis) using UPA-EX150 (manufactured by Nikkiso). Measured under measurement conditions of seconds, number of measurements: 3 times, measurement time: 180 seconds.

  Specific examples include copolymers in the form of blocks, random, grafts, etc., and salts thereof synthesized from at least two monomers selected from the following monomers and their derivatives.

  Examples of the monomer having an anionic group include unsaturated carboxylic acids such as (meth) acrylic acid, maleic acid, itaconic acid, fumaric acid, derivatives thereof, and salts thereof. Examples of the salt include alkali metal (lithium, sodium, potassium, etc.) salts, ammonium salts, and organic ammonium salts.

  The following are mentioned as a monomer which has a hydrophobic group.

  Α, β-ethylenically unsaturated compounds having a functional group or substituent aryl group derived from aromatic hydrocarbons such as phenyl group, benzyl group, tolyl group, o-xylyl group, naphthyl group and the like (meth) Acrylic acid alkyl ester.

  Examples of the α, β-ethylenically unsaturated compound having an aryl group include aromatic vinyl compounds such as styrene and α-methylstyrene; α, β such as benzyl (meth) acrylate and 2-phenoxyethyl (meth) acrylate. -An ester compound synthesized from an ethylenically unsaturated carboxylic acid and an alkyl alcohol having an aryl group. Examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, L (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl ( Meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, etc. Can be mentioned.

  Monomers having a nonionic group include (meth) acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth) acrylate and 3-methyl-5-hydroxypentyl (meth) acrylate; ethylene glycol (meth) acrylate, polyethylene glycol Mono (meth) acrylic acid ester of polyhydric alcohol such as (meth) acrylate; ethylene oxide such as methoxyethylene glycol (meth) acrylate, alkoxypolyalkylene glycol (meth) acrylic acid ester, 2-phenoxyethylene glycol (meth) acrylate (Meth) acrylic acid ester to which is added; and (meth) acrylamide compounds such as methyl (meth) acrylamide and ethyl (meth) acrylamide.

  The acid value of the anionic water-soluble resin is preferably from 60 mgKOH / g to 180 mgKOH / g, and more preferably from 70 mgKOH / g to 180 mgKOH / g. When the acid value of the anionic water-soluble resin is within the above range, sweeping is further suppressed.

  In particular, when the anionic water-soluble resin is used as a dispersant for the pigment, the mass ratio with respect to the pigment in the second ink is preferably 0.1 or more and 2.0 or less. By making the content of the anionic water-soluble resin within the above range, the dispersion of the pigment becomes more stable.

[Mass ratio of fine resin particles to anionic water-soluble resin]
In the present invention, it is important that the mass ratio of the resin fine particles and the anionic water-soluble resin (resin fine particles / anionic water-soluble resin) contained in the second ink is 2.5 or more and 7.5 or less. is there.

  When the mass ratio is less than 2.5, the ratio of the anionic water-soluble resin is large, and the volume shrinkage of the ink film increases when it comes into contact with the first ink. As a result, the ink film becomes brittle and image peeling tends to occur.

  On the other hand, when the mass ratio exceeds 7.5, the ratio of the resin fine particles is large, and since there are few things that hold the particles together, the ink film becomes brittle and image peeling tends to occur.

[Aqueous medium]
The first ink and the second ink according to the present invention can contain water and a mixed solvent with an organic solvent, and the organic solvent can be selected from those listed below. . Specifically, for example, alkyl alcohols having 1 to 4 carbon atoms such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol; dimethylformamide, Amides such as dimethylacetamide; Ketones or ketoalcohols such as acetone and diacetone alcohol; Ethers such as tetrahydrofuran and dioxane; Polyalkylene glycols such as polyethylene glycol and polypropylene glycol; Ethylene glycol, propylene glycol, butylene glycol, tri Alkyl having 2 to 6 carbon atoms such as ethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol and diethylene glycol Alkylene glycols containing an alkyl group; lower alkyl ether acetates such as polyethylene glycol monomethyl ether acetate; glycerin; ethylene glycol monomethyl (or ethyl) ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether, etc. Preferred examples include polyhydric alcohol lower alkyl ethers; polyhydric alcohols such as trimethylolpropane and trimethylolethane; N-methyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, etc. As mentioned.

  The content of the water-soluble organic solvent in the first ink and the second ink according to the present invention is not particularly limited, but is preferably in the range of 3 to 50% by mass with respect to the total mass of the ink. is there. The amount of water contained in the ink is preferably in the range of 50 to 80% by mass with respect to the total mass of the ink.

[Other ingredients]
The first ink and the second ink according to the present invention may contain a surfactant. Examples of the surfactant that can be added to the ink of the present invention include the following. Specifically, for example, anionic surfactants such as fatty acid salts, higher alcohol sulfate esters, liquid fatty oil sulfate esters and alkylallyl sulfonates can be used. Further, polyoxyethylene alkyl ethers and polyoxyethylene alkyl esters can be used. In addition, nonionic surfactants such as polyoxyethylene sorbitan alkyl esters, acetylene alcohol, and acetylene glycol can be used.

  In addition to the above components, the ink of the present invention contains various additives such as a pH adjuster, a rust inhibitor, a preservative, an antifungal agent, an antioxidant, and an anti-reduction agent as necessary. It's okay.

<Inkjet recording method>
[Application of first ink and second ink]
In the ink jet recording method according to the present invention, after applying the first ink on the recording medium, the image is obtained by applying the second ink so as to partially overlap the region to which the first ink is applied. Form.

  By adopting such an order, the zirconium compound contained in the first ink applied on the recording medium is gelled by the action of the pH of the second ink, and the second ink and the recording target are recorded. It acts as an adhesive layer that mediates media.

  In the ink jet recording method according to the present invention, at least the second ink is applied onto the recording medium by the ink jet recording method. On the other hand, the method for applying the first ink to the recording medium is not particularly limited, and as with the second ink, a method using an ink jet recording method may be used. It may be.

  In the ink jet recording method according to the present invention, it is necessary that the first ink and the second ink are in contact with each other in a liquid state on the recording medium. Therefore, it is necessary to apply the second ink promptly after applying the first ink. For this reason, the time from when the first ink is applied to when the second ink is applied is preferably 10 seconds or less.

The amount of the first ink applied to the recording medium is appropriately adjusted according to the type and content of the zirconium compound and amino acid contained in the first ink, or the amount of the second ink applied to the first ink. be able to. Specifically, the application amount of the first ink is 0.5 g / m ² or more and 10 g / m ² or less, so that image peeling is suppressed, high OD is achieved, sweeping is suppressed, solid uniformity, and the like. From the viewpoint of

  Examples of the recording medium used in the ink jet recording method according to the present invention include plain paper and coated paper. The use of plain paper as the recording medium is particularly preferable because the effects of the present invention can be obtained remarkably.

[Heat and pressure fixing]
In the ink jet recording method of the present invention, the fixing member is brought into contact with the image formed by applying the first ink and the second ink, and a heating and pressing process (contact heating and pressing process) is performed. . The contact-type heat and pressure treatment is excellent in energy saving effect because it can efficiently heat the recorded matter.

  In the present invention, the method for bringing the heating surface into contact is not particularly limited. For example, the following method is mentioned.

  A method of pressing a hot plate against a recording medium, and a heating and pressing apparatus including a pair of rollers, a pair of belts, or a belt disposed on the image recording surface side of the recording medium and a holding roller disposed on the opposite side And a method of passing between a pair of rollers and the like.

  The heat and pressure roller may be a metal metal roller or a metal core with a coating layer made of an elastic body and a surface layer (also referred to as a release layer) as required. Good. The latter metal core can be formed of, for example, a cylindrical body made of iron, aluminum, SUS, or the like, and the surface of the metal core is preferably at least partially covered with a coating layer. The coating layer is particularly preferably formed of a silicone resin or fluororesin having releasability. Moreover, it is preferable that the heat generating body is incorporated in one core metal of the heating and pressing roller. Further, by passing the recording medium between the rollers, the heat treatment and the pressure treatment may be performed simultaneously, or if necessary, the recording medium may be sandwiched and heated using two heating rollers. As the heating element, for example, a halogen lamp heater, a ceramic heater, a nichrome wire or the like is preferable.

  The heat treatment temperature is preferably 80 ° C to 120 ° C. When the heat treatment temperature is within the above range, the occurrence of curling can be further suppressed without disturbing the recorded image. In the present invention, the heat treatment temperature is the temperature of the surface of the recorded material during the heat treatment.

  As a method for measuring and controlling the temperature of the recorded material surface, for example, the surface temperature and moisture content of the recorded material are detected by an in-line sensor arranged upstream of the heat and pressure roller, and the roller temperature is changed according to the value. And controlling the temperature is preferable. Alternatively, the temperature of the recorded material surface immediately after the heat treatment is detected by an in-line sensor arranged on the downstream side of the heat and pressure roller, and the temperature of the recorded material surface during the heat treatment is controlled by feedback control of the roller temperature. It may be a method.

<Inkjet recording apparatus>
[Application of first ink and second ink]
Next, an example of an ink jet recording apparatus that can be suitably used in the present invention will be described below. FIG. 1 is a partial cross-sectional view showing an example of an ink jet recording apparatus having means for applying a first ink by a roller in an ink jet recording method according to the present invention. This ink jet recording apparatus employs a serial ink jet recording system.

  The apparatus includes a recording cassette 1, a sheet feeding tray 17 for feeding a recording medium 19, and a sheet feeding cassette 16 integrally formed with a means for applying the first ink according to the present invention. Drive means for moving the recording head, and control means for these components. The driving means is for reciprocally moving the recording head in a direction (main scanning direction) orthogonal to the conveyance direction (sub-scanning direction) of the recording paper.

  The recording head 1 is mounted on the carriage 2 so that the surface on which the ink discharge ports are formed is oriented toward the platen 11. The recording head 1 is mounted with an ink cartridge for containing the second ink according to the present invention in the carriage above it.

  The carriage 2 mounts the recording head 1 and can reciprocate along two guide shafts 9 extending in parallel along the width direction of the recording medium 19. The recording head 1 is driven in synchronism with the reciprocation of the carriage, and discharges the second ink droplets onto the recording medium 19 to form an image.

  The paper feed cassette 16 can be detached from the ink jet recording apparatus main body. The recording medium 19 is stacked and stored on a paper feed tray 17 in the paper feed cassette 16. When feeding paper, the uppermost recording medium 19 is pressed against the paper feed roller 10 by a spring 18 that presses the paper feed tray 17 upward. The paper feed roller 10 is a roller having a substantially half moon shape in cross section, is driven and rotated by a motor (not shown), and feeds only the uppermost recording medium 19 by a separation claw.

  The recording medium 19 that has been separated and fed is transferred to the conveyance surface 16A of the paper feed cassette 16 and the conveyance surface 27A of the paper guide 27 by the large-diameter intermediate roller 12 and the small-diameter application roller 6 that is in pressure contact therewith. Conveyed along. These transport surfaces are formed by curved surfaces that draw a concentric arc concentric with the intermediate roller 12. Accordingly, the recording medium 19 reverses its transport direction by passing through these transport surfaces 16A and 27A. In other words, the surface on which the recording medium 19 is printed is directed downward until it is conveyed from the paper feed tray 17 and reaches the intermediate roller 12, but when facing the recording head 1, the surface (upward) Turn to the recording head side.

In the illustrated apparatus, the first ink application unit according to the present invention is provided in the paper feed cassette 16. The said application | coating means is comprised by following (1)-(3).
(1) Replenishment tank 22 for supplying the first ink 15;
(2) a supply roller 13 rotatably supported in a state where a part of the peripheral surface is immersed in the tank 22;
(3) The application roller 6 that is arranged so as to be parallel to the supply roller 13 and that contacts the supply roller 13 and rotates in the same direction.
The application roller 6 is arranged so that the intermediate roller 12 for conveying the recording medium 19 is in contact with and parallel to the peripheral surface. Accordingly, when the recording medium 19 is transported, the intermediate roller 12 and the application roller 6 rotate with the rotation of the intermediate roller 12. As a result, the first ink 15 is supplied to the peripheral surface of the application roller 6 by the supply roller 13, and the first ink is evenly applied to the print surface of the recording medium 19 sandwiched between the application roller 6 and the intermediate roller 12. 15 is applied by the application roller 6.

[Heat and pressure fixing device]
The heat and pressure fixing device is not particularly limited as long as the fixing member is brought into contact with the image formed on the recording medium to perform heating and pressure processing. Hereinafter, among the heat and pressure fixing devices, a film heating method will be described as an example.

FIG. 2 is a schematic view showing an example of a film heating type heat and pressure fixing apparatus.
(1) In the heating device of the film heating system, a low heat capacity linear heating element having a low heat capacity made of a film-like thin film can be used as the heating element. Startability), and the temperature rise in the machine can be suppressed.
(2) In the heating device of the film heating system, since the fixing point and the separation point can be set separately, offset can be effectively prevented. In addition, various drawbacks of other system devices can be solved.

  In FIG. 2, reference numeral 36 denotes a heating body (ceramic heater) fixedly supported on a support. In the apparatus shown in FIG. 2, a heat resistant film (fixing film) 31 is used as a pressure rotator on the heating body 36. Are brought into close contact with the pressure roller 32 and slid and conveyed. Then, the image is fixed between the heat resistant film 31 and the pressure roller 32 in the pressure nip portion (fixing nip portion) N formed by the heating body 36 and the pressure roller 32 with the heat resistant film 31 interposed therebetween. A record P to be recorded is introduced. By transporting the recorded material P together with the heat resistant film 31 while sandwiching the pressure nip portion N, the heat of the heating body 36 is applied to the surface of the recorded material P through the heat resistant film 31 and is heat-fixed. The recorded matter P that has passed through the pressure nip N is separated from the surface of the film 31 and conveyed to the left in the drawing.

The heating body 36 of the fixing device shown in FIG.
(A) an elongated heat-resistant / insulating / good thermal conductive substrate 37 having a direction perpendicular to the heat-resistant film 31 or the conveyance direction a of the recorded product P;
(B) a resistance heating element 35 formed along the length of the substrate at the center in the short direction on the surface side of the substrate 37;
(C) Feeding electrodes (not shown) at both longitudinal ends of the resistance heating element 35,
(D) a heat resistant overcoat layer 38 that protects the surface of the heating element on which the resistance heating element is formed;
(E) A linear heating body having a low heat capacity as a whole, which is formed by a temperature measuring element 34 such as a thermistor for detecting the temperature of the heating body provided on the back side of the substrate.

  In the apparatus shown in FIG. 2, the heating body 36 is fixed by exposing and holding down the surface side on which the resistance heating element 35 is formed, and adhering and holding to a heater support (not shown) having rigidity and heat insulation. It is arranged. The heating body 36 is heated by the heat generation of the resistance heating element 35 over its entire length by feeding power to the both end electrodes of the resistance heating element 35. The temperature rise state is detected by the temperature detecting element 34, the detected temperature is fed back to a temperature control circuit (not shown), and the resistance heating element 35 is energized so that the temperature of the heating body is maintained at a predetermined temperature. Is controlled. That is, the energization to the resistance heating element 35 is controlled so that the detection output of the temperature detecting element (thermistor) 34 becomes constant at the time of fixing. In addition, as the heating body 36, you may use the heating apparatus by alternating magnetic field injection instead of the ceramic heater demonstrated above.

  In the apparatus shown in FIG. 2, the heat-resistant film 31 is formed in an endless belt shape, and one of the rollers on which the heat-resistant film 31 is suspended is used as a drive roller. It is rotated and conveyed by frictional force. As other methods of transporting the heat-resistant film 31, for example, the pressure roller 32 is used as a drive roller, or the roller is rotated by the frictional force between the drive roller brought into contact with the film outer surface in addition to the pressure roller 32 and the film outer peripheral surface. The thing of the structure to convey is mentioned. Moreover, the thing of the structure which makes the heat-resistant film 31 the long film of roll winding, and draws and conveys this is also mentioned.

  In the apparatus shown in FIG. 2, the outermost surface layer of the heat-resistant film 31 is provided with a release layer formed of a mixture of fluororubber and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer. ing. 2 is provided with a metal core 32a, an elastic layer 32b, a fluororubber layer 32c, and a fluororesin layer 33d. The pressure roller 32 having such a configuration is arranged in such a manner that the film 31 is narrowed with a predetermined pressing force by a bearing means / biasing means (not shown) and is brought into pressure contact with the surface of the heating body 36 described above. It is set up. When the pressure roller 32 is a film driving roller, a rotational force is transmitted to the pressure roller 32 from a driving unit (not shown) and is driven to rotate counterclockwise as indicated by an arrow.

  Next, an Example and a comparative example are given and this invention is demonstrated concretely. The present invention is not limited by the following examples unless it exceeds the gist. In the text, “part” or “%” is based on mass unless otherwise specified.

<Preparation of first ink>
[Preparation of ink]
Each ink was prepared using the components shown in Tables 1 and 2 below. Specifically, each component was blended so as to have the composition shown in Tables 1 and 2 (indicated by solid content), and after sufficient stirring, was applied to a filter (product name: HDCII; manufactured by Pall) having a pore size of 1.2 μm. Then, pressure filtration was performed to prepare Rct-1 to Rct-21.

  In Tables 1 and 2, ZC-126 and TC-315 represent the following.

ZC-126: Organics ZC-126 (Zirconium chloride, aminocarboxylic acid mixture; manufactured by Matsumoto Fine Chemical Co., Ltd., active ingredient concentration: 30%, metal content: 11.1%, solvent content: 70% water, pH: 3)
TC-315: ORGATICS TC-315 (titanium lactate; manufactured by Matsumoto Fine Chemical Co., Ltd., active ingredient concentration: 44%, metal content: 8.2%, solvent content: water 56%, pH: 1)

<Preparation of second ink>
[Preparation of resin fine particles]
(Preparation of EM1-EM5)
Resin fine particles were prepared using the components shown in Table 3 below. Specifically, in a four-necked flask equipped with a stirrer, a reflux cooling device, and a nitrogen gas introduction tube, 0.6 parts of sodium lauryl sulfate (emulsifier) and St (styrene) in the mass ratio shown in Table 3 were used. , EMA (ethyl methacrylate), BMA (butyl methacrylate), MAA (methacrylic acid) in total 40.0 parts and an emulsion prepared by mixing 48.8 parts of water were prepared. To this flask, 10.0 parts of 5% aqueous potassium persulfate solution was added dropwise over 3 hours. Then, after performing aging for 2 hours, solid content was adjusted with the appropriate amount of ion-exchange water, and the aqueous dispersion of resin fine particles EM1-EM whose resin solid content is 40.0% was obtained. Table 3 shows the particle diameter and minimum film-forming temperature (MFT) of each resin fine particle.

  The particle diameter is a volume average particle diameter (D50), and an aqueous solution in which resin fine particles are diluted with pure water so as to have a resin solid content of 0.4% is used. Then, using UPA-EX150 (manufactured by Nikkiso Co., Ltd.), measurement was performed under the measurement conditions of SetZero: 30 s, number of measurements: 3 times, measurement time: 180 seconds, and refractive index: 1.5.

(Preparation of EM8)
In a 2 liter three-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas introduction tube, 560.0 g of methyl ethyl ketone was charged and the temperature was raised to 87 ° C. outside the reaction vessel. While maintaining the reflux state in the reaction vessel (hereinafter refluxed until the end of the reaction), 87.0 g of methyl methacrylate, “FA-513M” (manufactured by Hitachi Chemical Co., Ltd.), 406.0 g, “PME-100” (day) (Oil Co., Ltd.) 29.0 g, methacrylic acid 58.0 g, methyl ethyl ketone 108 g, and “V-601” (Wako Pure Chemical Industries, Ltd.) 2.32 g were added dropwise in 2 hours. The solution was dropped at a constant speed. After completion of the dropwise addition, the mixture was stirred for 1 hour, (1) a solution consisting of 1.16 g of “V-601” and 6.4 g of methyl ethyl ketone was added, and the mixture was stirred for 2 hours. Subsequently, the process of (1) was repeated four times, and a solution consisting of 1.16 g of “V-601” and 6.4 g of methyl ethyl ketone was added and stirring was continued for 3 hours. Methyl methacrylate / FA-513M / PME-100 / A resin solution of a methacrylic acid (= 15/70/5/10 [mass ratio]) copolymer was obtained. The weight average molecular weight (Mw) of the obtained copolymer was 65,000.

  Next, 291.5 g of the resulting polymerization solution (solid content concentration 44.6%) was weighed, 82.5 g of isopropanol, 73.92 g of 1 mol / L NaOH aqueous solution were added, and the temperature in the reaction vessel was brought to 87 ° C. The temperature rose. Next, 352 g of distilled water was added dropwise at a rate of 10 ml / min to disperse in water. Thereafter, the temperature in the reaction vessel was kept at 87 ° C. for 1 hour, 91 ° C. for 1 hour, and 95 ° C. for 30 minutes under atmospheric pressure, and then the reaction vessel was evacuated to a total of 309. 4 g was distilled off to obtain an aqueous dispersion of EM8 having a solid content concentration of 26.5%.

[Preparation of anionic water-soluble resin]
(Preparation of AP1 to AP6)
An anionic water-soluble resin was prepared using each component shown in Table 4 below. Specifically, after adding 100.0 parts of ethylene glycol monobutyl ether to a four-necked flask equipped with a stirrer, a reflux cooling device, and a nitrogen gas inlet tube, nitrogen gas is introduced into the reaction system and stirred. The temperature was raised to 110 ° C. A mixture of parts by mass of St (styrene) and AA (acrylic acid) shown in Table 4 and ethylene glycol of TBHP (t-butyl peroxide; polymerization initiator) shown in Table 4 were added to this flask. The monobutyl ether solution was added dropwise over 3 hours. Thereafter, aging was performed for 2 hours, and ethylene glycol monobutyl ether was removed under reduced pressure to obtain a solid resin. The anionic water-soluble resin thus obtained was neutralized and dissolved at 80 ° C. by adding potassium hydroxide equivalent to its acid value and an appropriate amount of ion-exchanged water, and the solid content was 20%. An aqueous solution of certain anionic water-soluble resins AP1 to AP6 was obtained. Table 4 shows the weight average molecular weight (Mw) and acid value of each anionic water-soluble resin.

(Preparation of AP-8)
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, 0.85 g of dimethyl 2,2′-azobisisobutyrate, 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 reaction was further continued 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 a large excess of hexane, and the precipitated resin was dried. The anionic water-soluble resin thus obtained was neutralized and dissolved at 80 ° C. by adding potassium hydroxide equivalent to its acid value and an appropriate amount of ion-exchanged water, and the solid content was 20%. An aqueous solution of an anionic water-soluble resin AP8 was obtained. The weight average molecular weight (Mw) was 44,600, and the acid value was 65.2 mgKOH / g.

[Preparation of pigment dispersion]
(Preparation of Disp1-Disp4, Disp6-Disp13)
Each pigment dispersion was prepared using each component shown in Table 5 below. Specifically, each component was blended so as to have the composition (solid content notation) shown in Tables 1 and 2, and dispersed for 3 hours using a batch type vertical sand mill. Thereafter, coarse particles were removed by centrifugation. Furthermore, pressure filtration was performed with a cellulose acetate filter having a pore size of 3.0 μm (manufactured by Advantech) to obtain pigment dispersions Disp1 to Disp4 and Disp6 to Disp13 having a pigment concentration of 15.0% by mass.

  In Table 5, pigments and AP7 represent the following.

-Monak 880: Carbon black (manufactured by Cabot)
# 960: Carbon black (Mitsubishi Chemical)
・ PB15: 3: INK JET Cyan BG10 (manufactured by Clariant)
PR122: Cinquasia Magenta L 4400C (manufactured by BASF)
・ PY74: 5GX-70 (manufactured by Clariant)
AP7: BYK-190 (manufactured by Big Chemie; aqueous solution having a molecular weight of 2200, an acid value of 10 mgKOH / g, and a solid content of 40% by mass)

(Preparation of Disp5)
First, 3.16 g of anthranilic acid was added to a solution prepared by dissolving 10 g of concentrated hydrochloric acid in 10.6 g of water at 5 ° C. Next, a solution in which 3.56 g of sodium nitrite was added to 17.4 g of 5 ° C. water was added to the mixture while being kept at 10 ° C. or lower by stirring with an ice bath. Furthermore, after stirring this for 15 minutes, 14.0 g of Monac 880 (manufactured by Cabot) was added in the mixed state. Thereafter, the mixture was further stirred for 15 minutes. The obtained slurry was Toyo Filter Paper No. 2 (manufactured by Advantis), the pigment particles were sufficiently washed with water and dried in an oven at 110 ° C. Further, water was added to the dried pigment to adjust the pigment concentration to 15.0% by mass. A self-dispersed pigment dispersion Disp5 in which -Ph-COONH ₄ groups were introduced on the surface of carbon black was obtained ("-Ph-" means a phenylene group).

[Preparation of ink]
Each ink was prepared using the components shown in Tables 6 and 7 below. Specifically, each component was blended so as to have the composition shown in Tables 6 and 7 (solid content notation), and after sufficient stirring, was applied to a filter (product name: HDCII; manufactured by Pall) having a pore size of 1.2 μm. Then, pressure filtration was performed to prepare Ink-1 to Ink-24.

  In Tables 6 and 7, EM6 and EM7 represent the following.

EM6: Hardren NA-3002 (acid-modified polyolefin resin, manufactured by Toyobo Co., Ltd., pH: 8, acid value: 33 mg KOH / g, solid content 30%, Tg: 0 ° C., Mw: 78000)
EM7: Vylonal MD-2000 (polyester resin, manufactured by Toyobo Co., Ltd., pH: 6, solid content 40%, Tg: 67 ° C., Mw: 27000)

<Evaluation>
The first ink and the second ink obtained above are filled in the ink cartridge, respectively, and the ink cyan recording apparatus PIXUS PRO-10 (manufactured by Canon Inc.) has the first photo cyan position according to the combinations shown in Table 8 below. The ink cartridge of 1 ink was installed in the cyan and chroma optimizer positions. Then, a recorded matter having a recording duty of the first ink of 25% and a recording duty of the second ink of 100% was prepared on a Steinbeis Classic White as a recording medium. The condition for applying four drops of 4.0 pL of ink per unit area of 600 inches × 600 inches was defined as a recording duty of 100%.

  The time from application of the first ink to the recording medium to application of the second ink was 50 milliseconds.

This recorded material was subjected to heat and pressure fixing under the following conditions to evaluate image peeling, sweeping, color development and curling.
[Evaluation of image peeling, sweeping and curling]
The unfixed recorded matter obtained by the above-described ink jet recording apparatus was heated and pressurized 3 seconds after the second ink was applied to the recording medium. The heat and pressure treatment was adjusted using a heat and pressure fixing apparatus shown in FIG. 2 so that the surface of the recorded material was 95 ° C., and the pressure was 0.8 MPa and the conveyance speed was 4 inches / s. In Comparative Example 2, this heating and pressurizing treatment was not performed.

About the obtained recorded matter, the degree of image peeling and the degree of sweeping were visually observed.
The evaluation criteria for image peeling are as follows. The evaluation results are shown in Table 8.
AA: There was no image peeling.
A: Image peeling was slightly observed.
B: Some peeling of the image is observed, but it was a practically acceptable level.
C: Image peeling was remarkable.

The evaluation criteria for sweeping are as follows. The evaluation results are shown in Table 8.
AA: There was no sweeping.
A: A slight sweep was observed.
B: Some sweeping was observed, but it was an acceptable level for practical use.
C: The sweeping was remarkable.

Further, the obtained recorded matter was allowed to stand for 10 minutes, and the degree of curling in the recorded matter after standing was visually observed. The evaluation criteria for curl are as follows. The evaluation results are shown in Table 8.
A: Almost no curling.
B: Although curled somewhat, it was a practically acceptable level.
C: Curling was remarkable.

[Evaluation of color development]
The unfixed recorded matter obtained by the ink jet recording apparatus was heated and pressurized 20 seconds after the second ink was applied to the recording medium. The heat and pressure treatment was adjusted using a heat and pressure fixing apparatus shown in FIG. 2 so that the surface of the recorded material was 95 ° C., and the pressure was 0.8 MPa and the conveyance speed was 4 inches / s. In Comparative Example 2, this heating and pressurizing treatment was not performed. At this time, it was confirmed that images were peeled off and no sweeping was observed in the recorded materials of any of Examples and Comparative Examples.

About the obtained recorded matter, color developability was measured with a spectrophotometer (Spectrolino; manufactured by Gretag Macbeth). The evaluation criteria of color developability are as follows. The evaluation results are shown in Table 8.
AA: The image density is 1.50 or more.
A: The image density is 1.45 or more and less than 1.50.
B: The image density is 1.35 or more and less than 1.45.
C: The image density is less than 1.35.

[Wet contact]
An unfixed recorded material is produced in the same manner as the recorded material used in the evaluation of image peeling except that the recording duty of the first ink is 75% and the recording duty of the second ink is 10%. did.

  The unfixed recorded material was subjected to heating and pressure treatment 3 seconds after the second ink was applied to the recording medium. The heat and pressure treatment was adjusted using a heat and pressure fixing apparatus shown in FIG. 2 so that the surface of the recorded material was 95 ° C., and the pressure was 0.8 MPa and the conveyance speed was 4 inches / s. In Comparative Example 2, this heating and pressurizing treatment was not performed.

The obtained recorded matter was stapled with a No. 10 staple (manufactured by Max), allowed to stand in an environment of 30 ° C./80% RH for 5 hours, and then visually inspected for the degree of rust on the staple. The liquidity was evaluated. The evaluation criteria for wettability are as follows. The evaluation results are shown in Table 8.
A: Almost no rust was seen.
B: Although some rust was seen, it was a practically acceptable level.
C: Rust was remarkable.

DESCRIPTION OF SYMBOLS 1 Recording head 2 Carriage 3 Paper discharge roller 4 Spur 6 Application | coating roller (small diameter)
7 Main transport roller 8 Pinch roller 9 Guide shaft 10 Paper feed roller 11 Platen 12 Intermediate roller (large diameter)
DESCRIPTION OF SYMBOLS 13 Supply roller 14 Float 15 1st ink 16 Paper feed cassette 17 Paper feed tray 18 Spring 19 Recording medium 20 Inlet 21 Remaining amount display window 22 Replenishment tank 27 Paper guide 31 Heat resistant film (fixing film)
32 Pressure roller 34 Temperature sensor 35 Resistance heating element 36 Heating element (ceramic heater)
37 Heat-resistant / insulating / good thermal conductive substrate 38 Heat-resistant overcoat layer

Claims (6)

After applying the first ink on the recording medium, the fixing member is brought into contact with the image formed by applying the second ink so as to partially overlap the region to which the first ink is applied, and then heated. And an ink jet recording method for performing pressure treatment,
The first ink contains at least a zirconium compound and an amino acid;
The second ink contains at least a pigment, resin fine particles having a minimum film-forming temperature higher than a heat treatment temperature, and an anionic water-soluble resin, and a mass ratio of the resin fine particles to the anionic water-soluble resin (the An ink jet recording method, wherein the resin fine particles / the anionic water-soluble resin is 2.5 or more and 7.5 or less.   2. The inkjet according to claim 1, wherein an isoelectric point of the amino acid contained in the first ink is 5.5 or more, and a pH of the first ink at 25 ° C. is 2.5 or more and 4.5 or less. Recording method.   3. The ink jet recording method according to claim 1, wherein a minimum film forming temperature of the resin fine particles contained in the second ink is 20 ° C. or more higher than a heat treatment temperature.   The inkjet recording method according to any one of claims 1 to 3, wherein the acid value of the anionic water-soluble resin contained in the second ink is 60 mgKOH / g or more and 180 mgKOH / g or less.   The inkjet recording method according to any one of claims 1 to 4, wherein the zirconium compound is zirconium oxynitrate, zirconium oxychloride, zirconium oxyacetate, or basic zirconium chloride. The inkjet according to any one of claims 1 to 5, wherein the amino acid is alanine, arginine, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, proline, serine, threonine, tryptophan, tyrosine, or valine. Recording method.

Images