JP2006159478A - Reaction solution, set of reaction solution and ink, inkjet recording device and recording image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reaction solution, a set of the reaction solution and an ink, an inkjet recording device and a recording image forming method, with which a recorded matter having a high quality recording image with high optical density and a suppressed curling is obtained under the condition that no complication of a recording device and, at the same time, the change of coating amount after time lapse of the reaction solution is suppressed. <P>SOLUTION: This reaction solution is used in a recording image forming method having a process for giving an ink containing a coloring material under dissolved state or dispersed state and a process for giving the reaction solution making the dissolved state or dispersed state of the coloring material in the ink unstable through the contact with the ink. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a reaction liquid, a set of the ink and an ink, an ink jet recording apparatus, and an image recording method. And an image recording method using the same.

  As an ink jet recording method, a method of preparing a liquid for improving an image separately from a normal ink jet ink, and forming the image by adhering the liquid onto a recording medium prior to jetting of the recording ink, Various proposals have been made. For example, a method of recording an ink containing an anionic dye after depositing a liquid having a basic polymer (see, for example, Patent Document 1), a first liquid containing a reactive chemical species, and the reactive chemistry After a liquid containing an organic compound having two or more cationic groups per molecule is attached, a recording method (for example, see Patent Document 2) in which a liquid containing a compound that reacts with a species is mixed on a recording medium. A method for recording ink containing an anionic dye (see, for example, Patent Document 3) has been proposed. Also, after attaching an acidic liquid containing succinic acid or the like, a method of applying an ink containing an anionic dye (see, for example, Patent Document 4) or a method of applying a liquid for insolubilizing a dye prior to ink recording (For example, see Patent Documents 5 and 6) and the like have been proposed.

  However, any of the above methods attempts to suppress bleeding of the image and improve the water resistance of the image by folding the dye itself on the recording medium. The effect of suppressing bleeding is insufficient, and the folded dye tends to be unevenly distributed on the recording paper, so that the uniformity of image quality may be lowered. In particular, when plain paper is used as the recording medium, the tendency to be observed is remarkably observed because the covering property to the pulp fiber is deteriorated.

  On the other hand, in systems using pigments as ink coloring materials, an ink set using a combination of an ink containing a pigment dispersion and an ink containing a polyvalent metal has been proposed for the purpose of reducing bleeding on multicolored printed materials. In this case, for example, it is necessary to use a polyvalent metal in consideration of the compatibility with the colorant, that is, the stability of the ink, as the ink containing the polyvalent metal. There is another problem that there is a limitation and it is difficult to obtain a sufficient image density.

  As a method for solving such a problem, after applying a liquid composition containing polyvalent metal ions to a recording medium in advance, an ink having reactivity with the liquid composition is printed. Various recording methods for achieving the improvement in density have been proposed (see, for example, Patent Documents 8 to 12).

  Examples of the method for attaching the reaction liquid to the recording medium in the system for forming an image using the two liquids as described above include a coating method such as a roller coating method, a bar coating method, and a spray coating method. In addition, an ink jet recording method similar to ink can be used, and an image forming area to which the ink adheres and a coating method in which the reaction liquid is selectively attached only to the vicinity of the image forming area are also possible.

  Among the several methods of attaching a reaction liquid to a recording medium in a system that forms an image using two liquids, the present inventors have a more uniform distribution of reaction components on the recording medium with a small applied amount. I came to the view that the roller coating method is the best. However, when the reaction liquid is applied by roller coating or the like, there is a problem that the physical properties change due to evaporation of the liquid composition and the application amount fluctuates. As a means for solving this problem, for example, the hermeticity of the apparatus for applying the reaction liquid to the recording medium is improved, and the evaporation of the reaction liquid is suppressed. However, this solution is not a preferable method because it causes a problem that the apparatus becomes complicated.

In addition, when the reaction liquid is applied onto the recording medium by the roller coating method, the reaction liquid must be applied to a place where ink is not applied, and therefore, the curling (paper warping or curling) of the recording medium is likely to occur. There was a problem.
Japanese Unexamined Patent Publication No. 63-60783 Japanese Patent Laid-Open No. 63-22681 JP-A 63-299971 Japanese Unexamined Patent Publication No. 64-9279 JP-A-64-63185 JP-A 64-69381 JP-A-9-118850 JP 63-299970 A Japanese Patent Publication No. 6-86142 JP-A-9-207424 JP-A-11-349873 JP 2000-94825 A

  Therefore, an object of the present invention is to obtain a high-quality recorded image and a curled suppressed recorded material without complicating the recording apparatus, and to apply the reaction solution after aging. The present invention provides a reaction liquid, a set of a reaction liquid and an ink, an ink jet recording apparatus, and a recorded image forming method with suppressed changes.

  That is, the present invention provides a step of applying an ink containing a coloring material in a dissolved or dispersed state, and a reaction that destabilizes the dissolved or dispersed state of the coloring material in the ink by contacting the ink. A reaction liquid used in a recording image forming method including a step of applying a liquid, the reaction liquid including at least a polyvalent metal ion and an organic solvent having a vapor pressure of 3 kPa or less at 25 ° C., and the reaction liquid of the organic solvent The medium content is 70% or more, and the organic solvent is selected from the following 1) or 2), the first solvent being a highly soluble and highly volatile organic solvent for the polyvalent metal ion. It is a reaction liquid characterized by containing at least 2 sorts of the 2nd solvent which is a compound.

  1) A compound having a chemical structure of 4 or more carbon atoms and 3 or more OH groups.

  2) A compound having a chemical structure of 7 or more carbon atoms and having two OH groups.

  The present invention also provides a step of applying an ink containing a coloring material in a dissolved or dispersed state, and a reaction that destabilizes the dissolved or dispersed state of the coloring material in the ink by contacting the ink. An ink set of a reaction liquid and an ink used in a recording image forming method including a step of applying a liquid, the reaction liquid including at least a polyvalent metal ion and an organic solvent having a vapor pressure of 3 kPa or less at 25 ° C .; A first solvent in which the content of the organic solvent in the reaction solution is 70% or more, and the organic solvent is a highly soluble and highly volatile organic solvent with respect to the polyvalent metal ion, and the following 1) or 2 An ink set, which is a reaction liquid containing at least two kinds of a second solvent which is a compound selected from (1).

  1) A compound having a chemical structure of 4 or more carbon atoms and 3 or more OH groups.

  2) A compound having a chemical structure of 7 or more carbon atoms and having two OH groups.

  The present invention also provides a recording head for ejecting ink containing a coloring material in a dissolved state or a dispersed state, an ink cartridge having an ink containing portion containing ink, and supplying ink from the ink cartridge to the recording head. In an ink jet recording apparatus, comprising: an ink supply means for performing a reaction; and a means for supplying a reaction liquid that destabilizes a dissolved state or a dispersed state of a coloring material in the ink by contacting with the ink. At least a polyvalent metal ion and an organic solvent having a vapor pressure of 3 kPa or less at 25 ° C., the content of the organic solvent in the reaction solution is 70% or more, and the organic solvent is higher than the polyvalent metal ion. At least two kinds of a first solvent which is a soluble and highly volatile organic solvent and a second solvent which is a compound selected from the following 1) or 2) An ink jet recording apparatus, characterized in that the reaction liquid containing.

  1) A compound having a chemical structure of 4 or more carbon atoms and 3 or more OH groups.

  2) A compound having a chemical structure of 7 or more carbon atoms and having two OH groups.

  The present invention also provides a step of applying an ink containing a coloring material in a dissolved or dispersed state, and a reaction that destabilizes the dissolved or dispersed state of the coloring material in the ink by contacting the ink. A reaction liquid used in a recording image forming method including a step of applying a liquid, the reaction liquid including at least a polyvalent metal ion and an organic solvent having a vapor pressure of 3 kPa or less at 25 ° C., and the reaction liquid of the organic solvent The medium content is 70% or more, and the organic solvent is selected from the following 1) or 2), the first solvent being a highly soluble and highly volatile organic solvent for the polyvalent metal ion. It is a reaction liquid containing at least two kinds of the second solvent which is a compound.

  1) A compound having a chemical structure of 4 or more carbon atoms and 3 or more OH groups.

  2) A compound having a chemical structure of 7 or more carbon atoms and having two OH groups.

  By using the means of the present invention, it is possible to obtain a high-quality recorded image and a curl-suppressed recorded matter without complicating the recording apparatus, and to apply the reaction solution after aging. It is possible to obtain a reaction liquid, a set of reaction liquid and ink, an ink jet recording apparatus, and a recorded image forming method, in which the amount change is suppressed.

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

<Reaction solution>
The reaction liquid according to the present invention is used for image recording together with ink containing a color material in a dissolved or dispersed state, and has a function of destabilizing the dissolved or dispersed state of the color material in the ink. In particular, as a means for realizing the function, an excellent effect is exhibited in the case of a reaction liquid in an embodiment containing a substance that destabilizes the dissolved state or dispersed state of the colorant. The instability of the dissolved or dispersed state of the coloring material in the ink as used in the present invention means that when the ink and the reaction liquid are mixed, a state such as aggregation or gelation is caused in the mixture ( Hereinafter, it may also be expressed as “ink destabilization”). In the present invention, a polyvalent metal ion is used as a substance to be included in the reaction liquid in order to destabilize the ink.

(Polyvalent metal ion)
Specific examples of preferable polyvalent metal ions that can be used in the reaction solution according to the present invention include divalent metals such as Ca ²⁺ , Cu ²⁺ , Ni ²⁺ , Mg ²⁺ , Zn ²⁺ , Sr ^2+, and Ba ^2+. And trivalent metal ions such as Al ³⁺ , Fe ³⁺ , Cr ³⁺ and Y ^3+, but are not limited thereto. In order to contain these polyvalent metal ions in the reaction solution, a polyvalent metal salt is used. The salt is a metal salt composed of the polyvalent metal ions as mentioned above and an anion that binds to these ions, but is required to be soluble in water. Preferred anions for forming a salt include, for example, Cl ⁻ , NO ₃ ⁻ , I ⁻ , Br ⁻ , ClO ₃ ⁻ , SO ₄ ²⁻ , CO ₃ ²⁻ , CH ₃ COO ⁻ and HCOO ^−. Although it is mentioned, it is not limited to this.

In the present invention, Ca ²⁺ , Mg ²⁺ , Sr ²⁺ , Al ³⁺ and Y ³⁺ are particularly preferable as the polyvalent metal ion from the viewpoint of reactivity, colorability, and ease of handling. Ca ²⁺ is preferred. The anion is particularly preferably NO ₃ ⁻ from the viewpoint of solubility.

  In view of the effect of the present invention, the content of the polyvalent metal salt in the present invention is preferably 0.01 to 20% on a mass basis with respect to the total amount of the reaction solution. In order to sufficiently exhibit the function of destabilizing the ink, it is preferable to contain 0.01% or more of polyvalent metal ions with respect to the reaction solution. On the other hand, although it is possible to contain more than 20% of the polyvalent metal salt in the reaction solution, it is not so preferable because a significant increase in the function of destabilizing the ink cannot be expected. A preferable range of the content of the polyvalent metal ion is 0.01% or more and 10% or less on a mass basis with respect to the total amount of the reaction solution.

(Aqueous medium)
The reaction liquid of the present invention is formed by dissolving or dispersing the above-described components in an aqueous medium, and the content of the water-soluble organic solvent having a vapor pressure of 3 kPa or less at 25 ° C. in the ink is 70% or more based on the total amount of the ink. It is desirable to be. In the present invention, the temperature is 25 ° C. and the humidity is 50% R.D. H. In an environment, 5 g of a water-soluble organic solvent is placed in a 100 ml beaker made of Pyrex (registered trademark) glass that conforms to JIS R3503. H. It is allowed to stand in the following environment for 15 days to evaporate, and again at a temperature of 25 ° C. and a humidity of 50% H. Return the beaker where the ink remains in the environment, leave it for 2 hours, measure the weight in the same environment, and if the evaporation rate is 20% or more, it is a highly volatile organic solvent. Defined as organic solvent.

  Examples of highly volatile organic solvents include 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; Amides such as dimethylformamide and dimethylacetamide; Ketones or ketoalcohols such as acetone and diacetone alcohol; Ethers such as tetrahydrofuran and dioxane; Ethylene glycol, propylene glycol, butylene glycol, thiodiglycol, hexylene glycol, diethylene glycol and the like Alkylene glycols in which the alkylene group contains 2 to 6 carbon atoms; ethylene glycol monomethyl (or ethyl) ether, diethylene glycol methyl (or Le) ether, lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl (or ethyl) ether; 2-pyrrolidone, 1,5-pentanediol. Examples of the low volatile organic solvent include glycerin, diglycerin, triethylene glycol, 1,2,6-hexanetriol, polyethylene glycol (average molecular weight of about 200 to 600), polypropylene glycol, and the like. Of course, it is not limited to these. The water-soluble organic solvents as described above can be used alone or as a mixture.

  In the present invention, the temperature is 25 ° C. and the humidity is 50% R.D. H. In an environment, 10 g of a water-soluble organic solvent and 10 g of a polyvalent metal salt are placed in a 50 ml beaker made of Pyrex (registered trademark) glass in accordance with JIS R3503, stirred for 24 hours, and visually observed to obtain a solid polyvalent metal salt. Those in which the content is not confirmed are defined as a highly soluble organic solvent for the polyvalent metal salt, and those in which the solid content of the polyvalent metal salt is confirmed are defined as a low solubility organic solvent.

  In the present invention, the reason why a higher-quality recorded image can be obtained by using a highly soluble and highly volatile organic solvent for polyvalent metal ions is not clear, but is presumed to be as follows.

  After the reaction liquid is applied to the recording medium, the highly soluble and highly volatile solvent evaporates on the recording medium due to its high volatility, and polyvalent metal ions are deposited accordingly, and the surface layer of the recording medium Remains relatively much. Therefore, it is considered that the reaction efficiency with the color material in the ink is very high and a high-density recorded image can be obtained.

  Furthermore, examples of the solvent (curl reducing agent) effective for curling suppression of the printed material used in the present invention include one or more compounds selected from the compounds shown in the following 1) and 2).

1) Compound having a chemical structure having 4 or more carbon atoms and having 3 or more OH groups 2) Compound having a chemical structure having 7 or more carbon atoms and having 2 OH groups 1) Specific examples of the compound of 1) As trimethylolpropane, trimethylolethane, tris (hydroxymethyl) aminomethane, 1,2,6-hexanetriol, diglycerin, diglycerin EO adduct, saccharides, sugar alcohols, oligosaccharides, cyclic oligosaccharides, etc. There is. Specific examples of sugars include D-type and L-type fructose, tagatose, sorbose, ribose, xylose, arabinose, lyxose, glucose, mannose, allose, altrose, gurose, idose, galactose, talose, gulose, maltose, Examples include cellobiose, trehalose, gentiobiose, isomaltose, lactose, lactose, sucrose, sucrose, raffinose, gentianose, stachyose, xylan and the like. Examples of sugar alcohols include monosaccharides and polysaccharide alcohols, and specifically, tetritol, D-erythrol, L-erythrol, D-arabinitol, xylitol, adonitol, ribitol, D-sorbitol, allitol, D-mannitol, Examples thereof include D-iditol, D-talitol, dulcitol, heptitol, maltitol and the like.

Specific examples of the compound 2) include 1,7 heptanediol, tripropylene glycol, polyethylene glycol, polypropylene glycol and the like as diols having 7 or more carbon atoms and two OH groups. In particular, trimethylolpropane and polyethylene glycol are preferable in that they are inexpensive and highly versatile. The reason why a printed material with a small amount of curl can be obtained immediately after printing and also when the printed material is stored for a long period of time is considered as follows. When this occurs, the hydrogen bond formed between the cellulose fibers of the paper is broken once. That is, the application of moisture causes swelling of cellulose and chemical phenomena. At this time, since the paper is always swelled, the paper warps and curls on the opposite side of the surface to which moisture has been applied, that is, causes negative curl. However, once the moisture in the absorbed cellulose gradually evaporates, the shrinkage of the cellulose begins and recombination of hydrogen bonds once broken occurs. At that time, the paper does not recombine at the cut position, and the paper gradually warps and curls in the direction of the surface to which moisture is applied in order to recombine at another position. That is, plus curl occurs. This plus curl is particularly a problem with plain paper, but if it contains an appropriate amount of curl reducing compound, it effectively penetrates between the cellulose fibers, and the paper is re-bonded during hydrogen bonding recombination. It is speculated that it acts so as not to cause a bond that tends to shrink in the positive direction, resulting in a reduction in curl.

  Here, the plain paper includes commercially available copy paper, recycled paper for copying, plain paper for ink jet, plain paper for color ink jet, ink jet / electrophotographic paper, Japanese paper, and the like. More specifically, the paper surface is not coated with a special white pigment, or even if it is coated, the amount of coating is small and the pulp fiber of the underlying paper (base paper) is partially exposed. Including.

  The reaction solution of the present invention includes a first organic solvent that is highly soluble and highly volatile with respect to polyvalent metal ions, and a second solvent that is a curl reducing agent selected from 1) or 2) above. The content of the first solvent in the organic solvent is preferably 30% to 70% and the content of the second solvent is preferably 36% to 70%. Furthermore, it is more preferable that the first solvent in the organic solvent is 30% to 50% and the content of the second solvent is 43% to 70%.

  It is desirable to use deionized water as the water. The content of water contained in the ink is preferably 25% by weight or less based on the total weight of the ink.

(Other components of the reaction solution)
Moreover, the reaction liquid of this invention can contain the component mentioned below other than an above-described component.

[Polymer compound]
The reaction liquid of the present invention can further contain a polymer compound. With such a configuration, the polymer compound functions as a binder for the coloring material in the ink, so the scratch resistance of the formed recorded matter is improved. Can be made. The polymer compound used in the reaction liquid of the present invention is a nonionic water-soluble polymer that does not directly participate in the reaction between a component such as a coloring material in the ink and the polyvalent metal ion in the reaction liquid. It is preferable. Specific examples include water-soluble celluloses such as polyacrylamide, polyvinylpyrrolidone, carboxymethylcellulose, hydroxymethylcellulose, hydroxypropylcellulose, and resins such as polyvinylmethylether, polyvinyl acetal, and polyvinyl alcohol, but are not limited thereto. It is not something. For example, when an image is formed, a polymer compound in which an anion unit or a cation unit is added to these nonionic polymers may be used as long as the basic performance of the ink and the reaction liquid can be maintained. . Furthermore, the above-described polymer compound is satisfactory as long as it is water-soluble, but may be a dispersion such as latex or emulsion.

  The preferable addition amount of the polymer compound as mentioned above is preferably 0.01 to 20% on the mass basis with respect to the total amount of the reaction solution. That is, if it is 0.01% or more, the effect of improving the scratch resistance and fixability of the ink when an image is formed is exhibited. Also, within the above range, the viscosity of the reaction solution does not become too high.

<Other ingredients>
In addition to the above-mentioned components, the reaction solution of the present invention further contains a surfactant, an antifoaming material, a fungicide, an antiseptic, etc., as necessary, in order to give desired physical properties. Can be added.

  Surfactants that can be added at this time include fatty acid salts, higher alcohol sulfate esters, liquid fatty oil sulfate esters, alkylallyl sulfonates and other anionic surfactants, polyoxyethylene alkyl ethers, There are nonionic surfactants such as polyoxyethylene alkyl esters, polyoxyethylene sorbitan alkyl esters, acetylene alcohol, and acetylene glycol, and one or two or more of these can be appropriately selected and used. The amount used is preferably 0.01 to 10% on a mass basis with respect to the total amount of ink. At this time, it is preferable to determine the addition amount of the surfactant so that the surface tension of the reaction solution is 40 dyn / cm (mN / m) or less.

  Further, when the amount of the polyvalent metal salt in the reaction solution is increased, there are some types in which the pH of the reaction solution is lowered and others are lowered with time. In order to solve this, it is preferable to provide a buffering action against pH in the reaction solution. Preferable specific examples of the buffer capable of obtaining a buffering effect on pH include acetates such as sodium acetate, potassium acetate and lithium acetate, hydrogen phosphates, hydrogen carbonates, sodium hydrogen phthalate, hydrogen phthalate Hydrogen salt of polyvalent carboxylic acid such as potassium can be used. Furthermore, specific examples of polycarboxylic acids include, besides phthalic acid, malonic acid, maleic acid, succinic acid, fumaric acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, adipic acid, sebacic acid, dimer acid , Pyromellitic acid, trimellitic acid and the like. In addition to this, any known compound that exhibits a buffering effect on pH can be used as long as it is a substance that can keep the pH of the reaction solution within the preferable pH range by adding it. Can be used for invention. Among these, it is particularly preferable to use acetate from the viewpoint that it exhibits a buffering action at an appropriate pH as the pH of the reaction solution used in combination with the ink. In the present invention, the pH of the reaction solution is 2 or more. If the pH is less than 2, the components in the reaction solution may erode the surface of the member such as a tank or a roller, and the constituent components of the member may elute into the reaction solution and adversely affect the image. In the present invention, the pH of the reaction solution is preferably maintained in the range of 2 to 9, more preferably 3 to 7. Within this range, polyvalent metal ions can be more stably present in the reaction solution, so that the reactivity of the reaction solution can be sufficiently secured, and sufficient buffering action can be obtained. The long-term storage stability can be maintained.

  Furthermore, in the present invention, the reaction between the ink and the reaction liquid is more likely to occur more effectively when the pH of the reaction liquid is configured to be lower than the pH of the ink to be used together. It is more preferable from the viewpoints of solid uniformity and reverse penetration.

  Since the reaction liquid of the present invention having the above-described configuration is used in combination with ink when forming an image, it does not contain a coloring material, and is colorless and does not absorb in the visible range in consideration of the influence on the image. It is preferable. However, the present invention is not necessarily limited to this, and it may be a light-colored material that absorbs in the visible region as long as it does not affect the actual image. Absent.

<Ink>
The reaction liquid of the present invention having the above-described configuration is used for forming an image together with at least one kind of ink. In particular, an ink in which a coloring material is dispersed or dissolved in an aqueous medium by an ionic group. When used in recording, the above-described preferable effects can be obtained when an inkjet recording image is formed. Examples of the ink that can be suitably used in the present invention include pigment inks using pigments (microencapsulated pigments, and further colored resins and the like are also included in the category of pigments in the present application) as coloring materials. In particular, the reaction liquid of the present invention forms a color material aggregate on a recording medium when it is used for image formation in combination with a pigment ink in which a pigment is stably dispersed in an aqueous medium by an ionic group. Enables quality image formation. Therefore, the color material constituting the pigment ink used in the present invention includes a pigment having an anionic group chemically bonded to the surface, and further includes a pigment as the color material and an anionic dispersant. And the like. Hereinafter, components such as a pigment and an aqueous medium constituting the ink will be described in detail.

(Pigment)
Examples of the pigment that can be used in the present invention include carbon black and organic pigments.

[Carbon black]
Examples of the carbon black include carbon black pigments such as furnace black, lamp black, acetylene black, and channel black. For example, Raven 7000, Ray Van 5750, Ray Van 5250, Ray Van 5000, Ray Van 3500, Ray Van 2000, and Ray Van 1500. , Ray Van 1250, Ray Van 1200, Ray Van 1190ULTRA-II, Ray Van 1170, Ray Van 1255 (above Colombia), Black Pearls L, Legal 400R, Regal 330R, Legal 660R, Mogu L, Monak ( Monarch) 700, Monak 800, Monak 880, Monak 900, Monak 1000, Mon 1100, Monak 1300, Monak 1400, Vulcan XC-72R (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, Printex V, Printex 140U, Printex 140V, Special Black 6, Special Black 5, Special Black 4A, Special Black 4 (and above) Degussa), No. 25, no. 33, no. 40, no. 47, no. 52, no. 900, no. 2300, MCF-88, MA600, MA7, MA8, MA100 (manufactured by Mitsubishi Chemical) or the like can be used. However, it is not limited to these, and conventionally known carbon black can be used. Further, magnetic fine particles such as magnetite and ferrite, titanium black and the like may be used as the black pigment.

[Organic pigments]
Examples of organic pigments include insoluble azo pigments such as toluidine red, toluidine maroon, Hansa yellow, benzidine yellow, and pyrazolone red, soluble azo pigments such as ritole red, heliobordeaux, pigment scarlet, and permanent red 2B, alizarin, and indanthrone. Derivatives from vat dyes such as thioindigo maroon, phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green, quinacridone pigments such as quinacridone red and quinacridone magenta, perylene pigments such as perylene red and perylene scarlet, isoindolinone yellow , Isoindolinone pigments such as isoindolinone orange, imidazole such as benzimidazolone yellow, benzimidazolone orange and benzimidazolone red Pigments, pyranthrone pigments such as pyranthrone red, pyranthrone orange, indigo pigments, condensed azo pigments, thioindigo pigments, flavanthrone yellow, acylamide yellow, quinophthalone yellow, nickel azo yellow, copper azomethine yellow, peri Other pigments such as non-orange, anthrone orange, dianslaquinonyl red, dioxazine violet can be exemplified.

  Moreover, the following can be illustrated when an organic pigment is shown by a color index (CI) number. Of course, conventionally known organic pigments can be used in addition to the following.

C. I. Pigment Yellow: 12, 13, 14, 17, 20, 24, 74, 83, 86, 93, 109, 110, 117, 120, 125, 128, 137, 138, 147, 148, 151, 153, 154, 166 168 etc. C.I. I. Pigment Orange: 16, 36, 43, 51, 55, 59, 61 etc. C.I. I. Pigment Red: 9, 48, 49, 52, 53, 57, 97, 122, 123, 149, 168, 175, 176, 177, 180, 192, 215, 216, 217, 220, 223, 224, 226, 227 228, 238, 240, etc. C.I. I. Pigment Violet: 19, 23, 29, 30, 37, 40, 50, etc. C.I. I. Pigment Blue: 15, 15: 3, 15: 1, 15: 4, 15: 6, 22, 60, 64, etc. C.I. I. Pigment Green: 7, 36 etc. C.I. I. Pigment Brown: 23, 25, 26, etc.

[Dispersant]
When using the above-described carbon black or organic pigment, it is preferable to use a dispersant in combination. As the dispersant, those capable of stably dispersing the above pigment in an aqueous medium by the action of an anionic group are suitable. Specific examples of the dispersant include, for example, a styrene-acrylic acid copolymer, a styrene-acrylic acid-alkyl acrylate copolymer, a styrene-maleic acid copolymer, and a styrene-maleic acid-alkyl acrylate copolymer. Styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid alkyl ester copolymer, styrene-maleic acid half ester copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer, A styrene-maleic anhydride-maleic acid half ester copolymer or a salt thereof is included.

  These dispersants preferably have a weight average molecular weight in the range of 1,000 to 30,000, particularly preferably in the range of 3,000 to 15,000. Further, the acid value of the dispersant is preferably 300 mgKOH / g or less from the viewpoint of compatibility of ink reliability such as ink ejection stability and storage stability and reactivity between the ink and the reaction liquid. . More preferably, it is 100 mgKOH / g or more and 300 mgKOH / g or less. Further, the addition amount of the dispersant is preferably 0.1 or more and 3 or less with respect to the ratio (mass%) of the color material in the ink for the same reason as the acid value, and more preferably 0.2 or more. More preferably, it is 2 or less. From the viewpoint of ink reliability, increasing the acid value of the dispersant or increasing the addition amount tends to increase the ink stability with respect to the reaction liquid. In that case, sufficient image performance can be obtained by increasing the amount of polyvalent metal ions in the reaction solution. However, since the pH of the reaction solution tends to decrease, an amount of a substance exhibiting a buffering action is also necessary. It is preferable to increase it accordingly.

[Self-dispersing pigment]
In the present invention, a pigment that is obtained by bonding an ionic group (anionic group) to the pigment surface and that is dispersed in an aqueous medium without using a dispersant, that is, a so-called self-dispersing pigment is used as the coloring material. You can also. An example of such a pigment is self-dispersing carbon black. Examples of the self-dispersing carbon black include those in which an anionic group is bonded to the carbon black surface (anionic CB). Hereinafter, explanation will be given by taking carbon black as an example.

[Anionic CB]
The anionic CB includes, for example, at least one anion selected from —COO (M2), —SO ₃ (M2), —PO ₃ H (M2), and —PO ₃ (M2) 2 on the surface of carbon black particles. The thing which combined the sex group is mentioned. In the above formula, M2 represents a hydrogen atom, an alkali metal, ammonium or organic ammonium. Among these, carbon black obtained by bonding —COO (M2) or —SO ₃ (M2) to the surface of carbon black to be anionic is particularly suitable for the present invention because of its good dispersibility in ink. Can be used.

  By the way, among those expressed as “M2” in the hydrophilic group, specific examples of the alkali metal include Li, Na, K, Rb and Cs. Specific examples of organic ammonium include methyl ammonium, dimethyl ammonium, trimethyl ammonium, ethyl ammonium, diethyl ammonium, triethyl ammonium, methanol ammonium, dimethanol ammonium, and trimethanol ammonium.

  When an ink containing self-dispersing carbon black in which “M2” is ammonium or organic ammonium is used, the water resistance of the recorded image can be further improved, which is particularly preferable in this respect. This is considered to be due to the fact that when the ink is applied onto the recording medium, ammonium is decomposed and ammonia is evaporated. Here, as the self-dispersing carbon black in which “M2” is ammonium, for example, a method of substituting “M2” with ammonium using an ion exchange method for self-dispersing carbon black in which “M2” is an alkali metal, It can be obtained by, for example, a method in which an acid is added to form an H form, and then ammonium hydroxide is added to make “M2” ammonium.

  An example of a method for producing an anionically charged self-dispersing carbon black is a method of oxidizing carbon black with sodium hypochlorite. For example, this method can chemically bond —COONa groups to the surface of carbon black.

By the way, the various hydrophilic groups as described above may be directly bonded to the surface of the carbon black, or other atomic groups may be interposed between the carbon black surface and the hydrophilic group so as to form the hydrophilic group. The functional group may be indirectly bonded to the carbon black surface. Here, specific examples of the other atomic group include, for example, a linear or branched alkylene group having 1 to 12 carbon atoms, a substituted or unsubstituted phenylene group, and a substituted or unsubstituted naphthylene group. . Here, as a substituent of a phenylene group and a naphthylene group, a C1-C6 linear or branched alkyl group is mentioned, for example. Further, specific examples of the combination of another atomic group and the hydrophilic group, for _{example, -C 2 H 4 COO (M2} ), - Ph-SO 3 (M2), - Ph-COO (M2) , etc. (however, Ph represents a phenyl group).

  In the present invention, two or more of the above self-dispersing carbon blacks may be appropriately selected and used as the ink coloring material. Further, the addition amount of the self-dispersing carbon black in the ink is preferably in the range of 0.1 to 15%, particularly 1 to 10% on the mass basis with respect to the total amount of the ink. By setting this range, the self-dispersing carbon black can maintain a sufficiently dispersed state when it is contained in the ink. Furthermore, for the purpose of adjusting the color tone of the ink, a dye may be added as a coloring material in addition to the self-dispersing carbon black.

[Colored fine particles / microencapsulated pigment]
As the color material of the ink used in the present invention, in addition to the above, pigments microencapsulated with a polymer or the like, colored fine particles in which the periphery of resin particles is coated with a color material, and the like can also be used. The microcapsule inherently has dispersibility in an aqueous medium, but a dispersant as described above may be further coexisted in the ink in order to improve dispersion stability. Moreover, when using colored fine particles as a coloring material, it is preferable to use the anionic dispersant described above. The content of the color material as described above in the ink may be appropriately selected so as to have excellent ink jet discharge characteristics in the case of those used for ink jet recording and to have a desired color tone and density. As a standard, for example, a range of 1% to 50%, more preferably 1% to 10% is preferable based on the mass of the total mass of the ink.

(Aqueous medium)
The aqueous medium in which the pigment as described above is dispersed is not particularly limited, and the same aqueous medium as described above can be used as the aqueous medium used in the reaction liquid. When the color ink is adhered to a recording medium by an ink jet method (for example, bubble jet (registered trademark) method), the ink has a desired viscosity and surface tension so as to have excellent ink jet discharge characteristics as described above. It is preferable to prepare so that it has. Examples of the aqueous medium used in the ink used in the present invention include water or a mixed solvent of water and a water-soluble organic solvent. As the water-soluble organic solvent, those having an ink drying preventing effect are particularly preferable.

  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 2 to 6 alkylene groups such as ethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, diethylene glycol Alkylene glycols containing carbon atoms; 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. Lower alkyl ethers of polyhydric alcohols; polyhydric alcohols such as trimethylolpropane and trimethylolethane; N-methyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone and the like. The water-soluble organic solvents as described above can be used alone or as a mixture. Moreover, it is preferable to use deionized water as water.

  The content of the water-soluble organic solvent contained in the ink used in the present invention is not particularly limited, but it is preferably in the range of 3 to 50% on a mass basis with respect to the total amount of the ink. Further, the content of water contained in the ink is preferably in the range of 50 to 95% on the mass basis with respect to the total amount of the ink. Furthermore, in addition to the above components, a moisturizing agent may be added as necessary, and a surfactant, an antifoaming agent, an antiseptic, an antifungal agent, etc. may be added to obtain an ink having a desired physical property value. You may add.

  In the present invention, the pH of the ink is preferably 6 or more and 10 or less, and particularly preferably 7 or more and 9 or less. Further, as described above, in the present invention, when the pH of the reaction liquid is lower than the pH of the ink, the reaction between the ink and the reaction liquid is more likely to occur more effectively. It is more preferable from the viewpoint of the penetration property.

<Ink set>
The color of the ink when the ink set of the present invention is configured by combining the ink described above and the reaction liquid described above is not particularly limited. For example, yellow, magenta, cyan, red, green, blue And an ink showing one color tone selected from black. Specifically, the color material can be appropriately selected from the above-described color materials so as to obtain a desired color tone. Further, the ink to be combined with the reaction liquid is not limited to one type, and an embodiment in which two or more different color inks are combined to form an ink set suitable for forming a multicolor image is more preferable. The content of the color material in each ink may be appropriately selected so as to have excellent ink jet discharge characteristics when used in ink jet recording and to have a desired color tone and density. As a standard, for example, a range of 1 to 50% on the mass basis is preferable with respect to the total mass of the ink. In this case, it is sufficient that at least one of the two or more inks reacts with the reaction liquid.

  For example, as long as the color material is dispersed in an aqueous medium by the action of an ionic group, the other ink may be an ink containing a dye as a color material. The ink may be dispersed by the action of ionic groups. When the ink set of the present invention having such a configuration is used, bleeding when inks of different tones are applied adjacently on a recording medium, which is a problem when a multicolor image is formed by an ink jet apparatus, can be performed. Can be suppressed. More specifically, bleeding that is a problem in an inkjet multicolor image is at least one selected from black ink and other color inks (for example, yellow ink, magenta ink, cyan ink, red ink, green ink, and blue ink). Between the two inks). For this reason, as the ink destabilized by the reaction liquid of the present invention, for example, a black ink in which a pigment is dispersed in an aqueous medium by the action of an ionic group is preferably combined. Other color inks may be inks in which a dye is dissolved in an aqueous medium. Of course, all the other inks, like the black ink described above, are inks in which a coloring material is dispersed in an aqueous medium by the action of an ionic group, and are destabilized by the reaction liquid of the present invention. Also good.

<Recording method and apparatus>
The reaction liquid of the present invention is used for image formation in combination with ink destabilized by the reaction liquid. As a recording method at that time, a recording method in which at least ink recording is performed by an ink jet recording method is preferable. is there. More specifically, the method includes a step of applying a reaction liquid to at least a region of the recording medium to which ink is applied, and a step of applying ink to the recording medium by an ink jet method. Aggregates or gels at the top, and in particular, no color bleeding occurs. Furthermore, it is possible to stably obtain a high-quality image with high color density and high color development with reduced color material penetration on the back of the print. It becomes. That is, the reaction solution of the present invention is suppressed from changing with time, and even when stored, there is no significant change in the reactivity of the reaction solution with the ink, and there is no problem with the liquid contact property with the equipment member. Therefore, it is possible to stably obtain a high-quality image as described above.

  Examples of the method of applying the reaction liquid of the present invention to a recording medium include a method using an inkjet recording method as in the case of an ink, and a method of applying the reaction liquid of the present invention to a recording medium with a roller or the like. In these, the application | coating with a roller etc. which does not need to consider discharge property etc. is preferable.

The application amount of the reaction liquid to the recording medium, polyvalent metal ionic species and the amount thereof in the reaction solution itself or can therewith be appropriately prepared by an ink reacting, 0.5 g / m ² or more 10 g / m ² below It is preferable from the viewpoints of solid uniformity and fixability of the image of the obtained recorded matter. More preferably, it is more than ² g / m ² and 5 g / m ² or less.

<Inkjet recording apparatus>
FIG. 1 shows an example of an ink jet recording apparatus. This image forming apparatus employs a serial type ink jet recording system, and includes a recording head 1, a sheet feeding tray 17 for feeding a recording medium (hereinafter also referred to as recording paper) 19, and the reaction liquid of the present invention. The sheet feeding cassette 16 integrally formed with the means for applying the ink, the driving means for reciprocating the recording head in the direction orthogonal to the recording paper conveyance direction, and the control for controlling the driving of these components Means. 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. Although not shown, the recording head 1 includes the ink discharge port, a plurality of electric heating element elements (for example, heating resistance elements) for heating the ink liquid, and a substrate for supporting the same. The recording head 1 has an ink cartridge mounted in the carriage on the top thereof. The carriage 2 carries the recording head 1 and can reciprocate along two guide shafts 9 extending in parallel along the width direction of the recording paper 19. The recording head 1 is driven in synchronism with the reciprocating movement of the carriage and ejects ink droplets onto the recording paper 19 to form an image. The paper feed cassette 16 can be detached from the image forming apparatus main body. The recording paper 19 is stacked and stored on a paper feed tray 17 in the paper feed cassette 16. At the time of paper feeding, the uppermost sheet is pressed against the paper feed roller 10 by a spring 18 that presses the paper feed tray 17 upward. The sheet feeding roller 10 is a roller having a substantially half moon shape in cross section. The sheet feeding roller 10 is driven and rotated by a motor (not shown) to feed only the uppermost sheet (recording paper 19) by a separation claw (not shown). The separated recording paper 19 is fed along 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. Are transported. These transport surfaces are formed by curved surfaces that draw a concentric arc concentric with the intermediate roller 12. Therefore, the recording paper 19 reverses its transport direction by passing through these transport surfaces 16A and 27A. In other words, the surface on which the recording paper 19 is printed is directed downward until it is conveyed from the paper feed tray 17 and reaches the intermediate roller 12. Turn to the head side. Therefore, the printing surface of the recording paper always faces the outside of the image forming apparatus.

  The reaction solution applying means is provided in the paper feed cassette 16 and is a replenishment tank 22 for supplying the reaction solution 15 and an intermediate portion rotatably supported with a part of the peripheral surface immersed in the tank 22. The roller 12 and the application roller 6 are arranged so as to be parallel to the intermediate roller and are in contact with the intermediate roller 12 and rotate in the same direction. The application roller 6 is arranged so that the intermediate roller 12 for conveying the recording paper 19 and the peripheral surface are in contact with and parallel to each other. Therefore, when the recording paper 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 reaction liquid 15 is supplied to the peripheral surface of the application roller 6 by the supply roller 13, and the reaction liquid is evenly applied to the printing surface of the recording paper 19 sandwiched between the application roller 6 and the intermediate roller 12 by the supply roller 6. Is done.

  In the image forming apparatus, the float 14 is provided in the replenishing tank 22. The float 14 is a substance having a specific gravity lighter than that of the reaction solution 15 and floats on the surface of the reaction solution 15 so that the remaining amount of the reaction solution can be visually confirmed from the outside through the remaining amount display window 21 which is a transparent member. FIG. 2 is a front view of the remaining amount display portion. The remaining amount display portion is provided with a display indicating the level of the remaining amount along the longitudinal direction of the remaining amount display window 21. In the figure, the state where the surface of the reaction solution or the float 14 has reached the position indicated as “Full” is full. On the other hand, when the liquid level of the reaction solution or the float 14 is present at the position labeled “Add”, it indicates that the reaction solution is low. Therefore, it can be seen at a glance that the reaction solution 15 should be replenished when the reaction solution 15 is gradually reduced and the float 14 is lowered to the Add line.

  As a method of replenishing the reaction solution, as shown in FIG. 3, the tip of the injection device 23 is inserted into the injection port 20 made of a cut rubber member in a state where the paper feed cassette 16 is pulled out from the image forming apparatus main body. By inserting, the reaction liquid is injected into the replenishing tank 22. In this way, the recording paper coated with the reaction liquid is then fed by a predetermined amount by the main transport roller 7 and the pinch roller 8 in pressure contact therewith and transported to the recording unit, and ink is applied from the recording head 1. The The recording sheet 19 fed and printed in the above configuration is discharged and conveyed by the discharge roller 3 and the spur 4 in pressure contact with the discharge roller 3 and stacked on the discharge tray 5.

  In addition, when the reaction liquid is applied by a roller or the like, the ink can be effectively destabilized with a small application amount, particularly when the viscosity of the reaction liquid is higher than the viscosity of the ink. It is preferable because of its good fixability. More specifically, when the viscosity of the reaction liquid is higher, the polyvalent metal ions are more likely to stay above the recording medium, and thus more easily react with the ink.

  On the other hand, after the ink reacts with the reaction liquid, the colorant component in the ink stays above the recording medium, and the solvent, water, etc. quickly penetrate into the recording medium, that is, the solid-liquid separation can be performed quickly. Therefore, a lower viscosity is preferable from the viewpoint of the fixability of the recorded matter. The viscosity of the reaction liquid when the reaction liquid is applied by a roller or the like is preferably 3 mPa · s to 100 mPa · s, and more preferably 5 mPa · s to 60 mPa · s. The viscosity of the reaction liquid and ink in the present invention can be measured by a conventional method under an environment of 25 ° C.

  On the other hand, in the ink jet recording method, when both the ink constituting the ink set of the present invention and the reaction liquid are applied on the recording medium, the order of applying the ink onto the recording medium is various recording methods such as the following methods. However, any of them may be selected as appropriate.

  a: Ink is printed after the reaction solution is printed.

  b: The reaction solution is printed after the ink is printed.

  c: After the ink is printed, the reaction liquid is printed, and further the ink is printed.

  d: After printing the reaction liquid, the ink is printed and the reaction liquid is printed.

  In view of the object of the present invention, a) or d) including at least a step of recording the reaction liquid on a recording medium prior to the ink is preferable.

  FIG. 4 shows another example of the ink jet recording apparatus. In FIG. 4, reference numeral 61 denotes a blade as a wiping member, one end of which is held and fixed by a blade holding member, and forms a cantilever. The blade 61 is disposed at a position adjacent to the recording area by the recording head 65, and in this example, is held in a form protruding in the moving path of the recording head 65. Reference numeral 62 denotes a cap on the projection port surface of the recording head 65, which is disposed at a home position adjacent to the blade 61, moves in a direction perpendicular to the moving direction of the recording head 65, contacts the ink ejection port surface, and performs capping. The structure to perform is provided. Further, reference numeral 63 denotes an ink absorber provided adjacent to the blade 61 and, like the blade 61, is held in a form protruding in the moving path of the recording head 65. The blade 61, the cap 62, and the ink absorber 63 constitute an ejection recovery unit 64, and the blade 61 and the ink absorber 63 remove moisture, dust, and the like from the ejection port surface. Further, each ink of the recording head, and further, ink positioned at the discharge port of the reaction liquid is sucked by a pump (not shown) through a cap, and the original ink of the recording head, or the ink and the reaction liquid This constitutes a recovery unit that restores the original discharge performance. Reference numeral 65 denotes a recording head which has discharge energy generating means and performs recording by discharging ink onto a recording medium facing the discharge port surface where the discharge port is arranged. Reference numeral 66 denotes a movement of the recording head 65 by mounting the recording head 65. It is a carriage for performing. The carriage 66 is slidably engaged with the guide shaft 67, and a part of the carriage 66 is connected to a belt 69 (not shown) driven by a motor 68. As a result, the carriage 66 can move along the guide shaft 67, and the recording area and its adjacent area can be moved by the recording head 65. 51 is a paper feeding section for inserting a recording medium, and 52 is a paper feed roller driven by a motor (not shown). With these configurations, the recording medium is fed to a position facing the 65 discharge port surface of the recording head, and is discharged to a paper discharge portion provided with a paper discharge roller 53 as recording progresses. In the above configuration, when the recording head 65 finishes recording and returns to the home position, the cap 62 of the ejection recovery unit 64 is retracted from the moving path of the recording head 65, but the blade 61 protrudes into the moving path. As a result, the ejection port of the recording head 65 is wiped. When the cap 62 is in contact with the ejection surface of the recording head 65 to perform capping, the cap 62 moves so as to protrude into the moving path of the recording head. When the recording head 65 moves from the home position to the recording start position, the cap 62 and the blade 61 are at the same position as that at the time of wiping described above. As a result, the ejection port surface of the recording head 65 is wiped even during this movement.

  The above-mentioned movement of the recording head to the home position is not only at the end of recording or at the time of ejection recovery, but also to the home position adjacent to the recording area at a predetermined interval while the recording head moves the recording area for recording. Then, the wiping is performed with this movement.

<Ink characteristics; inkjet ejection characteristics, permeability to recording media>
The ink set according to the present invention is particularly suitable for inkjet recording. As the ink jet recording method, there are a recording method in which mechanical energy is applied to ink to eject droplets, and a recording method in which thermal energy is applied to ink and ink droplets are ejected by foaming of the ink. Not only the ink of the present invention but also a reaction liquid can be used. In that case, it is preferable that the reaction liquid and the ink having the above-described configuration according to the present invention have characteristics that can be ejected from an inkjet head. From the viewpoint of dischargeability from an inkjet head, the characteristics of these liquids are, for example, a viscosity of 1 to 15 mPa · s, a surface tension of 25 mN / m (dyne / cm) or more, particularly a viscosity of 1 to 5 mPa. -It is preferable that s and surface tension shall be 25-50 mN / m (dyne / cm). Furthermore, since the reaction liquid of the present invention needs to react only with a specific ink on a recording medium such as paper, the reaction liquid is reacted so that the reaction liquid does not bleed into a location other than the recording portion with the specific ink. It is preferable that the surface tension of the liquid be larger than that of the ink to be destabilized by the reaction liquid within a range that can be ejected from the inkjet head.

<Ink cartridge>
FIG. 5 is a diagram showing an example of a cartridge 45 that contains a member that supplies ink or reaction liquid to the recording head, for example, ink or reaction liquid supplied via a tube. Here, reference numeral 40 denotes a storage portion, for example, a bag, which stores ink for supply or reaction liquid, and a rubber stopper 42 is provided at the tip thereof. By inserting a needle (not shown) into the stopper 42, the ink or reaction liquid in the bag 40 can be supplied to the head. Reference numeral 44 denotes an absorber that receives waste ink or waste reaction liquid. The container 40 preferably has a liquid contact surface with an ink or a reaction liquid formed of polyolefin, particularly polyethylene. For example, as shown in FIG. 6, such a cartridge is configured to be detachable from a recording head 901 that discharges ink or a reaction liquid. In addition, when the cartridge 45 is mounted on the recording head, the ink or reaction is performed. The liquid is supplied to the recording head 901.

  EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited by these examples. Note that “%” means “mass%” unless otherwise specified.

  Reaction liquids 1 and 2 of the examples of the present invention having the following compositions and reaction liquids 3, 4 and 5 of comparative examples were prepared, respectively. As a specific preparation method, the following components were mixed, sufficiently stirred and dissolved, and then pressure-filtered with a microfilter having a pore size of 0.2 μm (manufactured by Fuji Film) to obtain each reaction solution. The viscosity was measured using a viscometer (VISCOMETER RE-80L manufactured by Toki Sangyo Co., Ltd.) in a 25 ° C. environment.

(Composition of reaction solution 1)
Calcium nitrate 1%
Ethylene glycol 37%
Trimethylolpropane 43%
Acetylene glycol ethylene oxide adduct 5%
(Product name: Acetylenol EH)
Water remaining

(Composition of reaction solution 2)
Calcium nitrate 1%
Ethylene glycol 30%
Trimethylolpropane 50%
Acetylene glycol ethylene oxide adduct 5%
(Product name: Acetylenol EH)
Water remaining (Comparative Example 1)
(Composition of reaction solution 3)
Calcium nitrate 1%
Ethylene glycol 40%
Glycerin 40%
Acetylene glycol ethylene oxide adduct 5%
(Product name: Acetylenol EH)
Water remaining (Comparative Example 2)
(Composition of reaction solution 4)
Calcium nitrate 1%
Ethylene glycol 30%
Trimethylolpropane 36%
Acetylene glycol ethylene oxide adduct 5%
(Product name: Acetylenol EH)
Water remaining (Comparative Example 3)
(Composition of reaction liquid 5)
Calcium nitrate 1%
Ethylene glycol 60%
10% trimethylolpropane
Acetylene glycol ethylene oxide adduct 5%
(Product name: Acetylenol EH)
Remaining water <Solubility>
The solubility of the polyvalent metal salt used in the composition of the reaction solution and the solvent was measured. Temperature 25 ° C., humidity 50% R.D. H. Under an environment, 10 g of a water-soluble organic solvent and 10 g of a polyvalent metal salt were placed in 50 ml of a JIS R3503 beaker made of Pyrex (registered trademark) glass, stirred for 24 hours, and visually observed. The results are shown in Table 1.

<Preservation test>
The viscosity change due to evaporation of the reaction liquids 1 and 5 obtained above was measured. The reaction solution was allowed to evaporate in an environment of a temperature of 60 ° C. and a relative humidity of 5% until 20% of the total reaction solution had evaporated. The results are shown in Table 2.

  A black black ink having the following composition was prepared as an ink to be used with each of the reaction solutions described above.

(Black ink)
10 parts of pigment (carbon black (product name: MogulL, manufactured by Cablack)), anionic polymer P-1 (styrene-acrylic acid copolymer, acid value 200, weight average molecular weight 10,000, solid content 10%) 20 parts of aqueous solution, neutralizer: potassium hydroxide) and 70 parts of pure water are mixed, the following materials are charged into a batch type vertical sand mill (made by IMEX), and 150 parts of 0.3 mm diameter zirconia beads are filled. The dispersion treatment was performed for 5 hours while cooling with water. After the dispersion was centrifuged to remove coarse particles, a pigment dispersion black having a solid content of about 12% and a weight average particle size of 120 nm was obtained in the final preparation.
(Ink composition)
Pigment dispersion black 30%
Glycerin 9%
Diethylene glycol 6%
Acetylene glycol ethylene oxide adduct 1%
(Product name: Acetylenol EH)
54% of water
<Evaluation of curl evaluation and reverse penetration>
The reaction liquids of Examples 1 and 2 and Comparative Examples 1 to 3 were applied onto a recording medium with a coating roller, and the temperature was 25 ° C. and the humidity was 50% R.D. H. It was left to stand for 3 days under the environment, and the curl of the recorded matter was visually observed. At that time, the speed of the roller and the contact pressure of the roller to the recording medium were adjusted so that the coating amount was 2.4 g / m ² . In addition, Canon PB paper was used as the recording medium. The evaluation items are shown below, and the results are shown in Table 3.

<Evaluation criteria for curls>
A: There is almost no curling.
B: Some curling is confirmed.
C: Curling is remarkable. On the other hand, immediately after applying the reaction liquid onto the recording medium with a coating roller, the black ink 1 is printed on a 2 cm square using an ink jet recording apparatus BJS700 (manufactured by Canon Inc.). From the back side, the degree of penetration of the black ink 1 was visually observed. The evaluation items are shown below, and the results are shown in Table 3.

<Evaluation criteria for strikethrough>
A: There is almost no ink breakthrough.
B: Some ink see-through is confirmed, but there is no problem in actual use.
C: Ink breakthrough is remarkable.

It is a schematic sectional side view which shows an example of the inkjet recording device of this invention. It is a front sectional view of a reaction liquid remaining amount display part provided in the ink jet recording apparatus of the present invention. It is a schematic sectional side view which shows the reaction liquid replenishment state of the inkjet recording device of this invention. It is a schematic perspective view which shows an example of the inkjet recording device of this invention. It is a longitudinal cross-sectional view which shows an example of an ink cartridge. FIG. 3 is a schematic plan view showing a state in which the ink cartridge according to one embodiment of the present invention is mounted on a recording head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recording head 2 Carriage 3 Paper discharge roller 4 Spur 5 Paper discharge tray 6 Coating roller 7 Main conveyance roller 8 Pinch roller 9 Guide shaft 10 Paper feed roller 11 Platen 12 Intermediate roller 13 Supply roller 14 Float 15 Reaction liquid 16 Paper feed cassette 17 Paper feed tray 18 Spring 19 Recording medium (recording paper)
20 Inlet 21 Remaining amount display window 22 Replenishment tank 23 Filling device 27 Paper guide 40 Ink bag 42 Plug 44 Ink absorber 45 Ink cartridge 51 Paper feed unit 52 Paper feed roller 53 Paper discharge roller 61 Blade 62 Cap 63 Ink absorber 64 Discharge recovery unit 65 Recording head 66 Carriage 67 Guide shaft 68 Motor 69 Belt 901 Recording head

Claims (10)

A step of applying an ink containing a color material in a dissolved state or a dispersed state; and a step of applying a reaction liquid that destabilizes the dissolved state or the dispersed state of the color material in the ink by contacting the ink. A reaction liquid used in a recording image forming method having at least a polyvalent metal ion and an organic solvent having a vapor pressure of 3 kPa or less at 25 ° C., and the content of the organic solvent in the reaction liquid is 70%. The second solvent is a compound selected from the following 1) or 2), the first solvent being a highly soluble and highly volatile organic solvent for the polyvalent metal ion: A reaction liquid comprising at least two kinds of solvents.
1) A compound having a chemical structure of 4 or more carbon atoms and 3 or more OH groups.
2) A compound having a chemical structure of 7 or more carbon atoms and having two OH groups.   The reaction solution according to claim 1, wherein the content of the first solvent in the organic solvent is 30% or more and 70% or less, and the content of the second solvent is 36% or more and 70% or less.   The reaction solution according to claim 1 or 2, wherein the polyvalent metal ion is 0.01% or more and 10% or less on a mass basis with respect to the total amount of the reaction solution.   The reaction solution according to any one of claims 1 to 3, wherein the pH of the reaction solution is 2 or more and 7 or less. A step of applying an ink containing a color material in a dissolved state or a dispersed state; and a step of applying a reaction liquid that destabilizes the dissolved state or the dispersed state of the color material in the ink by contacting the ink. An ink set of a reaction liquid and an ink used for a recorded image forming method, the reaction liquid including at least a polyvalent metal ion and an organic solvent having a vapor pressure at 25 ° C. of 3 kPa or less, in the reaction liquid of the organic solvent A compound selected from the following 1) or 2): a first solvent having a content of 70% or more and the organic solvent being a highly soluble and highly volatile organic solvent for the polyvalent metal ion; An ink set comprising a reaction liquid containing at least two kinds of the second solvent.
1) A compound having a chemical structure of 4 or more carbon atoms and 3 or more OH groups.
2) A compound having a chemical structure of 7 or more carbon atoms and having two OH groups. A recording head for discharging ink containing a coloring material in a dissolved state or a dispersed state, an ink cartridge having an ink containing portion containing ink, and an ink supply means for supplying ink from the ink cartridge to the recording head And an ink jet recording apparatus comprising means for supplying a reaction liquid that destabilizes the dissolved or dispersed state of the colorant in the ink by contact with the ink, wherein the reaction liquid comprises at least polyvalent metal ions and Including an organic solvent having a vapor pressure of 3 kPa or less at 25 ° C., the content of the organic solvent in the reaction solution is 70% or more, and the organic solvent has high solubility and high volatility in the polyvalent metal ion. A reaction liquid containing at least two kinds of a first solvent which is an organic solvent and a second solvent which is a compound selected from the following 1) or 2) An ink jet recording apparatus according to claim Rukoto.
1) A compound having a chemical structure of 4 or more carbon atoms and 3 or more OH groups.
2) A compound having a chemical structure of 7 or more carbon atoms and having two OH groups.   The inkjet recording apparatus according to claim 6, wherein the pH of the reaction liquid is lower than the pH of the ink.   The ink jet recording apparatus according to claim 6, wherein the viscosity of the reaction liquid is higher than the viscosity of the ink.   The ink jet recording apparatus according to claim 6, further comprising an application roller that applies the reaction liquid to the recording medium. A step of applying an ink containing a color material in a dissolved state or a dispersed state; and a step of applying a reaction liquid that destabilizes the dissolved state or the dispersed state of the color material in the ink by contacting the ink. The reaction liquid contains at least polyvalent metal ions and an organic solvent having a vapor pressure of 3 kPa or less at 25 ° C., and the content of the organic solvent in the reaction liquid is 70% or more, At least two of the first solvent, which is a highly soluble and highly volatile organic solvent for the polyvalent metal ion, and the second solvent, which is a compound selected from the following 1) or 2): A recorded image forming method, which is a reaction solution containing seeds.
1) A compound having a chemical structure of 4 or more carbon atoms and 3 or more OH groups.
2) A compound having a chemical structure having 7 or more carbon atoms and having two OH groups.

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