JP2008137365A - Liquid composition, set, and image recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid composition which restrains a deposit generated by moisture evaporation on the surface of a coating roller for supplying the liquid composition to a recording medium and restrains poor conveyance of the recording medium by a curling phenomenon. <P>SOLUTION: The liquid composition is used for an image recording method, which comprises a step of supplying ink including color material in a melting state or a dispersing state to the recording medium, and a step of providing the liquid composition for unstabilizing the dissolving state or the dispersing state of the color material in the ink by the contact with the ink to the recording medium. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid composition, a set of the liquid composition and an ink, and an image recording method, and in particular, a liquid composition and a liquid in the case of performing recording by using the liquid composition and the ink together on a recording medium. The present invention relates to a set of a composition and an ink.

  Various methods for forming an image by preparing a liquid for improving the image and applying the liquid on a recording medium prior to the ink application as an ink jet recording method, in addition to the normal ink jet ink, are proposed. Has been. For example, a method of recording an ink containing an anionic dye after applying a liquid containing a basic polymer to a recording medium is disclosed (Patent Document 1).

  In addition, in a system using a pigment as an ink coloring material, an ink set using a combination of an ink containing a pigment dispersion and an ink containing a polyvalent metal for the purpose of reducing ink bleeding in a multicolored recorded matter. Has been proposed (Patent Document 2).

  Furthermore, as a proposal using the reactivity of two kinds of liquids as described above, a liquid composition containing polyvalent metal ions is applied to a recording medium in advance, and then an ink reactive with the liquid composition is recorded ( Hereinafter, it is called a two-component system). (Patent Document 3)

Examples of the method for adhering the liquid composition to the recording medium include application methods such as a roller coating method, a bar coating method, and a spray coating method. In addition, an ink jet recording method is used in the same manner as the ink, and an application method in which the liquid composition is selectively attached only to the vicinity of the image forming region to which the ink is attached and the image forming region is also possible.
However, when the liquid composition is applied to the recording medium by the roller coating method, the following two problems have occurred. First, as the liquid composition is applied over a wide area of the recording medium, the first problem is that it tends to cause a curl (paper warping or curling) phenomenon that occurs when the recording medium is given moisture. A problem sometimes occurred. As a second problem, there is a case where a solid component is deposited on the surface of an application roller for applying the liquid composition to the recording medium, thereby affecting the image.

  Many methods for suppressing the curl phenomenon have been proposed (Patent Documents 4 and 5). However, it has been found that there is the following problem in a system in which a liquid composition is applied to a recording medium by a roller coating method, and then the recording medium is transported in a recording apparatus and then ink is applied. That is, it has been found that the recording medium may curl during conveyance until ink is applied to the recording medium coated with the liquid composition, and a conveyance failure may occur during conveyance.

Japanese Unexamined Patent Publication No. 63-60783 JP-A-9-118850 JP 2000-94825 A JP-A-4-332775 JP-A-6-157955

  Accordingly, an object of the present invention is to provide a recording method using an ink containing a color material in a dissolved state or a dispersed state and a liquid composition that destabilizes the dispersed state of the color material by contact with the ink. An object of the present invention is to provide a liquid composition that solves these two problems. That is, the first problem is to suppress precipitates generated due to water evaporation on the surface of the coating roller for applying the liquid composition to the recording medium. A second problem is to suppress the conveyance failure of the recording medium due to the curl phenomenon. Furthermore, it is to provide a set of the ink and the liquid composition, and further an image recording method using the set.

As a result of intensive studies to solve the above-described problems, the present inventors have reached the present invention.
That is, the present invention provides a step of applying an ink containing a coloring material in a dissolved state or a dispersed state to a recording medium, and a state in which the coloring material in the ink is dissolved by contacting the recording medium with ink. Applying a liquid composition that destabilizes the dispersion state, and a liquid composition used for an image recording method,
The liquid composition includes a polyvalent metal ion, the following compound 1-1, the following compound 1-2, and the following compound 2.
And at least one of the following compounds 2 is a low volatility compound,
And the content based on the total mass of the liquid composition of the following compounds 1-1 X ₁ (wt%), the content based on the total mass of the liquid composition of the following compound 1-2 X ₂ (wt%) and the following Provided is a liquid composition characterized in that the content Y (% by mass) of the compound 2 based on the total mass of the liquid composition satisfies the relationship of the following formulas (1), (2) and (3).

(1) 0.1 ≦ (X ₂ + Y) / X ₁ ≦ 2.5
(2) 15% by mass ≦ X ₁ + X ₂
(3) 3% by mass ≦ X ₂ + Y
[Compound 1-1]: The difference between the moisture retention in an environment of temperature 23 ° C./45% relative humidity and the moisture retention in an environment of temperature 30 ° C./relative humidity 80% is 36% or less, and the molecular weight Mw Is a water-soluble polyhydric alcohol or water-soluble amide compound in the range of 100 ≦ Mw ≦ 1,000.
[Compound 1-2]: The difference between the moisture retention in an environment of temperature 23 ° C./45% relative humidity and the moisture retention in an environment of temperature 30 ° C./relative humidity 80% is 36% or less, and the molecular weight Mw Is a water-soluble alkanediol having a range of 100 ≦ Mw ≦ 150 and having OH groups at both ends of the main chain.
[Compound 2]: A water-soluble organic compound other than the colorant and compounds 1-1 and 1-2.

In the liquid composition of the present invention, the content Y (% by mass) based on the total mass of the liquid composition of the compound 2 is Y <15% by mass,
In addition, it is preferable that the difference between the moisture retention in the environment of 23 ° C./45% relative humidity and the moisture retention in the environment of 30 ° C./80% relative humidity of the compound 2 is 40% or more.

  Further, in the liquid composition of the present invention, the compound 1-1 has a polyhydric alcohol having at least three ether bonds, a polyhydric alcohol having at least three OH groups, and an OH group or an ether bond. It is preferably selected from the group consisting of polyhydric alcohols having at least one hydrophilic bonding group (bonding group having hydrogen bonding properties).

Moreover, in the liquid composition of the present invention, the content X ₁ (mass%) of the compound 1-1, the content X ₂ (mass%) of the compound 1-2, and a content Y (mass of the compound 2). %) Further preferably satisfies the relationship of the following formula (4).
(4) 0 <Y / (X ₁ + X ₂ ) ≦ 0.9

  The present invention also includes a step of applying an ink containing a coloring material in a dissolved state or a dispersed state to a recording medium, and a state in which the coloring material in the ink is dissolved by contacting the recording medium with the ink. A step of applying a liquid composition that destabilizes the dispersion state, and a set of ink and liquid composition for use in an image recording method, wherein the liquid composition is the liquid composition of the present invention. Provide a set characterized by being.

  The present invention also includes (i) a step of applying an ink containing a coloring material in a dissolved or dispersed state to a recording medium, and (ii) dissolution of the coloring material in the ink by contacting the ink. Applying a liquid composition that destabilizes the state or dispersion state, and performing the step (i) after the fixing of the liquid composition to the recording medium in the step (ii) is completed. A recording method is provided, wherein the liquid composition is the liquid composition of the present invention.

  According to the present invention, as a method for applying a liquid composition to a recording medium, even when a roller coating method is used, a liquid composition, a set, and an image forming method that suppress precipitates generated by moisture evaporation on the surface of the application roller Can be provided. Further, according to another embodiment of the present invention, in addition to the above-described effects, it is possible to provide a liquid composition, a set, and an image forming method that further suppress the conveyance failure of the recording medium due to the curl phenomenon.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. First, the background to the present invention will be described.
The present inventors consider that the curl phenomenon after applying a liquid medium containing water to a recording medium such as plain paper has some correlation with the evaporation of moisture applied to the recording medium, The following detailed study was conducted on the water retention of organic compounds.

First, 20% by mass aqueous solutions of various water-soluble organic compounds were prepared, 10 g each was precisely weighed into a glass petri dish, and allowed to stand in an environment of temperature 23 ° C./relative humidity 45%. At the same time, pure water containing no water-soluble organic compound was also allowed to stand. In a petri dish of a 20% by mass aqueous solution of a water-soluble organic compound, the amount of a substance (solid or liquid) in the petri dish decreases with the evaporation of water, and the mass eventually becomes constant. At the same time, the pure water-only petri dish that has been allowed to stand at the same time has all its pure water evaporated, so what remains in the petri dish containing the water-soluble organic compound is retained by the water-soluble organic compound and the compound. The water retention of each compound was calculated by the following formula. In the following formula, mass means mass (g: gram) excluding the mass of the petri dish. Further, the mass of the water-soluble organic compound is the mass of the water-soluble organic compound charged first, and in the case of the above example, it is 2.0 g.

  Next, the petri dish is moved to an environment at a temperature of 30 ° C./relative humidity of 80%, and similarly, waiting for equilibrium to occur, the mass of the substance remaining in the petri dish is measured in this environment, and the water retention capacity is It calculated | required according to the formula of. Furthermore, the same petri dish was moved again to the environment of temperature 23 degreeC / relative humidity 45%, the mass of the substance which remained in the petri dish was measured, and the water | moisture retention was similarly calculated | required. The obtained results are shown in FIG. Further, FIG. 8 shows the difference in moisture retention between the two environments.

  The present inventors consider that there is some correlation between the difference in moisture retention in the above-described environment and the occurrence of curling of plain paper, and applying the aqueous solution containing the water-soluble organic compound examined above to plain paper, The occurrence was examined. As a result, it was discovered that a water-soluble organic compound (compounds 1-1 and 1-2 of the present invention) having a difference in water retention in both environments of 36% or less significantly suppresses curling. Therefore, as a result of preparing liquid compositions containing only polyvalent metal salts, additives and these water-soluble organic compounds and observing the occurrence of curling, curling occurred not only immediately after recording but also after several days at room temperature. It has been found that this is not the case and the present invention has been reached.

  The curl phenomenon in plain paper is that the moisture applied by the recording once enters between the hydrogen bonds between the fibers, and the tension that was initially tension is loosened as the moisture moves due to evaporation, etc. From this, it is considered that this occurs when only the recording portion contracts. A water-soluble organic compound whose water retention ability is difficult to change stably retains a certain amount of moisture, and therefore hardly moves with the evaporation of moisture. As a result, it is assumed that curling is suppressed.

  As a result of further detailed studies, the present inventors have found that a compound having a water retention difference of 17.5% or more (compound 1-1 of the present invention) has an effect of suppressing curling over a long period of time. found. The reason why the effect is obtained is not clear, but the inventors presume as follows. That is, the water-soluble organic compound (compound 1-2 of the present invention) having a water retention difference of less than 17.5% has a weak hydrogen bonding force, but once enters a hydrogen bond between cellulose of paper, I think that it will migrate and move gradually.

  Specific examples of compound 1-1 include the following. Polyethylene glycol having an average molecular weight of 200 to 1,000, for example, polyethylene glycol 200, polyethylene glycol 300, polyethylene glycol 600, polyethylene glycol 1,000, and the like. In addition, 1,2,6-hexanetriol, trimethylolpropane, trimethylolethane, N, N′-bis- (2-hydroxyethyl) -urea and the like. At least one of these can be used. Among the above, it is preferable to use a polyhydric alcohol having the following characteristics as the compound 1-1. That is, a polyhydric alcohol having at least three ether bonds, a polyhydric alcohol having at least three OH groups, and at least one hydrophilic bonding group (bonding group having hydrogen bonding properties) in addition to an OH group or an ether bond. The polyhydric alcohol which has is preferable. Among these, it is particularly preferable to use 1,2,6-hexanetriol and N, N′-bis- (2-hydroxyethyl) -urea. This is because these compounds have a particularly high effect of suppressing curling over a short period of time immediately after recording.

  Specific examples of compound 1-2 include alkanediols having —OH groups at both ends of the carbon main chain which may have a substituent. For example, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3-methyl-1,5-pentanediol, 2-amino-2-methyl-1,3-propanediol, 2 -Amino-2-ethyl-1,3-propanediol and the like. At least one of these can be used.

Furthermore, as a result of the study by the present inventors, the total content of the compound 1-1 and the compound 1-2 in the liquid composition is set to 15% by mass or more, so that the amount of the liquid composition applied to the recording medium is increased. It was found that curling immediately after coating can be sufficiently suppressed when the amount is 5 g / m ² or less. Furthermore, when the total content of compound 1-1 and compound 1-2 is 25% by mass or more, it is more preferable in terms of curling suppression.

  On the other hand, when a liquid composition is applied to a recording medium by a roller coating method, it is difficult to suppress moisture evaporation of the liquid composition on an application roller or the like, and a solid component in the liquid composition is precipitated to form an image. There was a problem of influencing. In particular, when a solid compound at room temperature such as trimethylolpropane, N, N′-bis- (2-hydroxyethyl) -urea, 1,6-hexanediol is used as a water-soluble organic compound, precipitation is remarkable. there were. It has been found that it is necessary to contain a low-volatile compound as the compound 2 in the liquid composition for such a problem.

(Low volatile compound: Compound 2)
The low volatility compound in the present invention is defined as follows. That is, 5 g of a water-soluble organic compound is put into 100 ml of a beaker made of Pyrex (registered trademark) compliant with JIS R3503 in an environment of temperature 25 ° C./relative humidity 50%. Thereafter, the water-soluble organic compound is allowed to evaporate for 15 days in an environment of a temperature of 60 ° C./humidity of 5% or less, and then the water-soluble organic compound evaporated again in an environment of temperature 25 ° C./relative humidity 50% remains Return the beaker you are using. Then, after leaving again for 2 hours, the mass evaporation rate calculated by measuring the mass in the same environment is defined as a volatile organic compound having a mass evaporation rate of 20% or more, and a compound having a mass evaporation rate of less than 20% is defined as a low volatile organic compound. . Specific examples of the low volatile organic compound include glycerin, triethylene glycol, polypropylene glycol and the like. Of these, glycerin is particularly preferable. Of course, it is not limited to these.

From the above examination results, the best liquid composition capable of solving both the first problem and the second problem of the present invention includes a liquid composition having the following configuration. That is, it is necessary that the liquid composition contains a polyvalent metal ion, the compound 1-1, the compound 1-2, and the compound 2, and at least one of the compounds 2 is a low volatility compound. . Furthermore, the content based on the total mass of the liquid composition of the compound 1-1 is X ₁ (mass%), and the content based on the total mass of the liquid composition of the compound 1-2 is X ₂ (mass%). And the content based on the liquid composition total mass of the said compound 2 is set to Y (mass%). At this time, it is necessary that X ₁ , X ₂ and Y described above satisfy the relationship of the following formulas (1), (2) and (3).
(1) 0.1 ≦ (X ₂ + Y) / X ₁ ≦ 2.5
(2) 15% by mass ≦ X ₁ + X ₂
(3) 3% by mass ≦ X ₂ + Y

(Measurement method of molecular weight Mw)
The measuring method of the molecular weight of the compound 1-1, 1-2 and the compound 2 was determined by any of the following methods. For those having a molecular weight distribution, the weight average molecular weight was taken as the molecular weight.
(1) JIS handbook chemical analysis According to K0118 and K0123, mass spectrum measurement, gas chromatography mass spectrometry (GC-MS method), and liquid chromatography mass spectrometry (LC-MS method) were performed, and molecular weight was measured.
(2) Polyethylene glycol having a molecular weight distribution was determined as a molecular weight by obtaining an average molecular weight from a size exclusion chromatography method (GPC method) according to JIS Handbook Chemical Analysis K0124. Furthermore, the water-soluble organic compound having a molecular weight distribution other than polyethylene glycol was determined as a molecular weight by obtaining a weight average molecular weight in terms of polyethylene glycol.
(3) The structure of the compound was identified and the molecular weight was determined. The compound was structurally identified from NMR, infrared analysis, elemental analysis, etc., and the molecular weight was determined from this.

Next, components and physical properties constituting the liquid composition and ink of the present invention, and conditions for applying the liquid composition to a recording medium will be described.
(Polyvalent metal ions and their salts)
Preferred polyvalent metal ions that can be used in the liquid composition of the present invention include the following. For example, divalent metal ions such as Ca ²⁺ , Cu ²⁺ , Ni ²⁺ , Mg ²⁺ , Zn ²⁺ , Sr ²⁺ and Ba ²⁺ , Al ³⁺ , Fe ³⁺ , Cr ³⁺ and And trivalent metal ions such as Y ³⁺ . In order to contain these polyvalent metal ions in the liquid composition, 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 the salt include, for example, Cl ⁻ , NO ₃ ⁻ , I ⁻ , Br ⁻ , ClO ₃ ⁻ , SO ₄ ²⁻ , CO ₃ ²⁻ , CH ₃ COO ⁻ and HCOO ^−. Can be mentioned. In the present invention, Ca ²⁺ , Mg ²⁺ , Sr ²⁺ , Al ^3+, and Y ³⁺ are particularly preferable as the polyvalent metal ions from the viewpoint of reactivity, colorability, and ease of handling. Ca ²⁺ is more preferable. As the anion, NO ₃ ⁻ is particularly preferable from the viewpoint of solubility.

  The content (mass%) of the polyvalent metal ion in the liquid composition is 0.01 mass% or more and 10.0 mass% or less based on the total mass of the liquid composition in consideration of the effect of the present invention. Is preferred. More preferably, it is 1.0 mass% or more and 5.0 mass% or less. Furthermore, in order to sufficiently exhibit the function of destabilizing the ink and to obtain a high level of image uniformity and optical density, it is 2.0% by mass or more and 4.0% by mass or less based on the total mass of the liquid composition. It is preferable to contain a polyvalent metal ion. In addition, it is also possible to contain polyvalent metal ion exceeding 10.0 mass% in a liquid composition. However, when the content of polyvalent metal ions exceeds 10.0% by mass, the addition of compound 2 is performed to suppress the generation of precipitates on the surface of the application roller for applying the liquid composition to the recording medium. There will be a need to increase the amount. Furthermore, even if more than 10.0% by mass is added, a significant increase in the function of destabilizing the ink cannot be expected. For the above reasons, the content of polyvalent metal ions in the liquid composition is preferably 10.0% by mass or less.

  In addition, the liquid composition does not include a color material and is preferably transparent, but does not necessarily need to exhibit no absorption in the visible range. That is, even if absorption is shown in the visible range, absorption may be shown in the visible range as long as it does not substantially affect the image.

(Physical properties of liquid composition and application conditions)
As a result of various studies on the two-component system by the present inventors, the degree of curling of the recording medium when ink is applied to the recording medium to which the liquid composition has been applied is that a large amount of color material aggregates are present on the surface layer portion of the recording medium. It was found that the more it was present, the more it was suppressed. The reason for this is not clear, but the aggregate formed by the contact between the polyvalent metal ions in the liquid composition and the color material in the ink is present in the surface layer of the recording medium, so that moisture is present in the recording medium. This is presumably because the shrinkage of cellulose that occurs after the application is suppressed.

  A condition for allowing the aggregate to exist at a position where the aggregate penetrates slightly in the depth direction from the surface layer portion of the recording medium is to control the reactivity between the liquid composition and the ink. Furthermore, it is important that a sufficient amount of polyvalent metal ions for aggregating the coloring material is present within approximately 30 μm from the surface of the recording medium. In order for a large amount of polyvalent metal ions in the liquid composition to be present in the surface layer of the recording medium, the amount of the polyvalent metal ions in the liquid composition as well as the amount of the liquid composition applied to the recording medium are greatly involved. I think that.

Therefore, the liquid composition of the present invention preferably exhibits the following characteristics. That is, the coating amount of the liquid composition on the recording medium is preferably 0.5 g / m ² or more and 5 g / m ² or less. More preferably, it came to a conclusion that the coating amount was 2.0 g / m ² or more and 3.0 g / m ² or less. In addition, the application amount of the liquid composition in the present invention can be appropriately adjusted depending on the physical properties of the liquid composition, the rotation speed of the roller of the application apparatus, the contact pressure of the roller with respect to the recording medium, and the like.

  In addition, in order to verify to which position of the recording medium the liquid composition has penetrated, the liquid composition is applied after coloring the liquid composition and applying a prescribed coating amount to the recording medium. This is possible by observing the cross section of the portion with an optical microscope.

Furthermore, it is preferable to apply the ink after the fixing of the liquid composition to the recording medium is completed in order to distribute the aggregates of the coloring material at a certain depth from the surface of the recording medium. In the present invention, “the time when the fixing property is completed” means that in the following formula (a), the value of Ka (t−tw) ^1/2 is based on the applied amount of the liquid composition actually applied to the recording medium. Means the point when

The Ka value in the present invention is determined by the Bristow method as a measure representing the permeability of the liquid composition to the recording medium. That is, when the permeability of the liquid composition is represented by the liquid composition amount V per 1 m ² , the recording medium of the liquid composition after a predetermined time t (msec: millisecond) has elapsed since the liquid composition was applied. The amount of penetration V (mL / m ² = μm) is expressed by the Bristow equation shown below.
V = Vr + Ka (t−tw) ^1/2 (a)

  Here, immediately after the liquid composition adheres to the surface of the recording medium, the liquid composition is mostly absorbed in the uneven portions on the surface of the recording medium (the roughness portion of the surface of the recording medium). It hardly penetrates into the medium. The time between them is the contact time (tw), and the amount of the liquid composition absorbed in the uneven portions of the recording medium at the contact time is Vr. When the contact time is exceeded after the liquid composition is adhered, the amount of penetration into the recording medium is increased by an amount proportional to the time that exceeds the contact time, that is, (t-tw) to the 1/2 power. . Ka is a proportional coefficient of this increase, and indicates a value corresponding to the penetration rate. The Ka value can be measured using a Bristow method liquid dynamic permeability tester (for example, trade name: Dynamic permeability tester S; manufactured by Toyo Seiki Seisakusho).

  The Ka value according to the Bristow method in the present invention is a plain paper [PB paper used for printers using an ink jet recording system, PPC paper used for copying machines using an electrophotographic system, etc.] as a recording medium. It is the value measured using. As a measurement environment, a normal office environment, for example, a temperature of 20 to 25 ° C./relative humidity of 40 to 60% is assumed.

(Other components in the liquid composition)
As a component used for a liquid composition, it is set as the liquid composition which has a desired physical-property value as components other than a low volatile compound, a polyvalent metal ion, water, the compound 1-1, the compound 1-2, and the compound 2. Therefore, a surfactant, an antifoaming agent, an antiseptic, an antifungal agent and the like can be appropriately added.

(ink)
The liquid composition described above can be used for recording in combination with an ink in which a coloring material is dispersed or dissolved in an aqueous medium by an ionic group, thereby obtaining a favorable effect such as being able to form a high quality image. Examples of the colorant that can be used in such inks include pigments dispersed with a dispersant (resin dispersion type pigments), self-dispersing pigments, microencapsulated pigments, and colored fine particles. Hereinafter, these color materials will be described in detail.

(Pigment)
Examples of the pigment that can be used include carbon black and organic pigments. One kind or two or more kinds of various pigments can be used in combination.

(Carbon black)
Examples of the carbon black include carbon black pigments such as furnace black, lamp black, acetylene black, and channel black. For example, the following can be used.
Ray Van: 7000, 5750, 5250, 5000, 3500, 2000, 1500, 1250, 1200, 1190, ULTRA-II, 1170, 1255 (manufactured by Columbia). Black Pearls L, Legal: 400R, 330R, 660R, Mogul L, Monak: 700, 800, 880, 900, 1000, 1100, 1300, 1400, Valcan XC-72R (manufactured by Cabot). Color Black: FW1, FW2, FW2V, FW18, FW200, S150, S160, S170, Printex: 35, U, V, 140U, 140V, Special Black: 6, 5, 4A, 4 (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). 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.

(Organic pigment)
Specifically, the following can be used as the organic pigment.
Insoluble azo pigments such as Toluidine Red, Toluidine Maroon, Hansa Yellow, Benzidine Yellow, and Pyrazolone Red. Soluble azo pigments such as Ritolol Red, Helio Bordeaux, Pigment Scarlet, and Permanent Red 2B. Derivatives from vat dyes such as alizarin, indanthrone and 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 pigments such as isoindolinone yellow and isoindolinone orange. Imidazolone pigments such as benzimidazolone yellow, benzimidazolone orange, and benzimidazolone red. Pilanthrone pigments such as pyranthrone red and pyranthrone orange. Thioindigo pigment. Condensed azo pigment. Thioindigo pigment. Flavanthrone yellow, acylamide yellow, quinophthalone yellow, nickel azo yellow, copper azomethine yellow, perinone orange, anthrone orange, dianthraquinonyl red, dioxazine violet, etc.

Moreover, when an organic pigment is shown by a color index (CI) number, the following can be used.
C. I. Pigment Yellow: 12, 13, 14, 17, 20, 24, 74, 83, 86, 93, 109, 110, 117, 120, 125, 128, 137, and the like. In addition, C.I. I. Pigment Yellow: 138, 147, 148, 151, 153, 154, 166, 168, etc. C. I. Pigment Orange: 16, 36, 43, 51, 55, 59, 61, etc. C. 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. Pigment violet: 19, 23, 29, 30, 37, 40, 50, and the like. C. I. Pigment Blue: 15, 15: 3, 15: 1, 15: 4, 15: 6, 22, 60, 64, and the like. C. I. Pigment Green: 7, 36, etc. C. I. Pigment Brown: 23, 25, 26, etc. Of course, conventionally known organic pigments can be used in addition to the above.

(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 suitably used. As specific examples of the dispersant, for example, the following can be used. Styrene-acrylic acid copolymer, styrene-acrylic acid-alkyl acrylate ester copolymer, styrene-maleic acid copolymer, styrene-maleic acid-alkyl acrylate copolymer, styrene-methacrylic acid copolymer, etc. . Styrene-methacrylic acid-acrylic acid alkyl ester copolymer, styrene-maleic acid half ester copolymer, vinyl naphthalene-acrylic acid copolymer, and the like. Vinyl naphthalene-maleic acid copolymer, styrene-maleic anhydride-maleic acid half ester copolymer, and the like. Or the salt of these copolymers, etc. are contained. These dispersants preferably have a weight average molecular weight in the range of 1,000 to 30,000, and particularly preferably in the range of 3,000 to 15,000.

(Self-dispersing pigment)
As the coloring material, a pigment that can be dispersed in an aqueous medium without a dispersant by bonding an ionic group (anionic group) to the pigment surface, a so-called self-dispersing pigment can also be used. 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 surface of the carbon black.

(Anionic carbon black)
Examples of the anionic carbon black include at least one anion selected from —COO (M2), —SO ₃ (M2), —PO ₃ H (M2), and —PO ₃ (M2) _{2 on} the surface of the carbon black. 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 use in the present invention because of its excellent dispersibility in the ink. To get.

  By the way, among those represented as “M2” in the hydrophilic group, specific examples of the alkali metal include, for example, Li, Na, K, Rb and Cs, and specific examples of the organic ammonium include For example, the following are mentioned. Methylammonium, dimethylammonium, trimethylammonium, ethylammonium, diethylammonium, triethylammonium, methanolammonium, dimethanolammonium, trimethanolammonium and the like.

  An example of a method for producing an anionically charged self-dispersing carbon black is a method of oxidizing carbon black with sodium hypochlorite. By this method, a -COONa group is chemically bonded to the carbon black surface. Can be made.

By the way, various hydrophilic groups as described above may be directly bonded to the surface of carbon black. Alternatively, other atomic groups may be interposed between the carbon black surface and the hydrophilic group, and the hydrophilic group may be indirectly bonded to the carbon black surface. 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, examples of the substituent of the phenylene group and the naphthylene group include a linear or branched alkyl group having 1 to 6 carbon atoms. Also, specific examples of the combination of another atomic group and the hydrophilic group is, for _{example, -C 2 H 4 COOM, -Ph} -SO 3 M, such as -Ph-COOM (provided that, Ph represents a phenylene group) include It is done.

  By the way, in the present invention, two or more kinds of self-dispersing carbon blacks described above may be used as the ink coloring material appropriately selected. Further, the content (% by mass) of the coloring material in the ink is 0.1% by mass or more and 15.0% by mass or less, particularly 1.0% by mass or more and 10.0% by mass or less based on the total mass of the ink. It is preferable to set it as the range. By setting this range, the coloring material can maintain a sufficiently dispersed state in the ink. Further, for the purpose of adjusting the color tone of the ink, a dye may be added as a coloring material in addition to the pigment as described above. In this case, as the dye, any conventionally known dye used as a dye for ink jet ink can be used.

(Colored fine particles / microencapsulated pigment)
In addition to the color materials described above, pigments microencapsulated with a polymer or the like, and colored fine particles in which the periphery of resin particles is coated with a color material can also be used. The microencapsulated pigment has dispersibility in an aqueous medium, but a dispersant as described above may be further used to increase the dispersion stability. Moreover, when using colored fine particles as a coloring material, it is preferable to use the anionic dispersant described above.

(Aqueous medium)
The aqueous medium for dispersing or dissolving the color material as described above is not particularly limited as long as it can be used for ink. When adhering 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.

  Examples of the aqueous medium used in the ink of 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 effect of preventing drying of the liquid composition are particularly preferable. Specifically, for example, the following can be used. 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; and polyalkylene glycols such as polyethylene glycol and polypropylene glycol. Alkylene glycols in which an alkylene group contains 2 to 6 carbon atoms, such as ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, hexylene glycol and diethylene glycol; Lower alkyl ether acetates such as polyethylene glycol monomethyl ether acetate. Glycerin. Alkyl ethers of polyhydric alcohols such as ethylene glycol monomethyl (or ethyl) ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether. Polyhydric alcohols such as trimethylolpropane and trimethylolethane. Thiodiglycol, 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 (% by mass) of the water-soluble organic solvent in the ink is not particularly limited, but is preferably in the range of 3.0% by mass or more and 50.0% by mass or less based on the total mass of the ink. The water content (% by mass) in the ink is preferably in the range of 50.0% by mass or more and 95.0% by mass or less, preferably 82.0% by mass or less, more preferably based on the total mass of the ink. Is 77.0 mass% or less, more preferably 72.0 mass% or less.

  Furthermore, in addition to the above components, a moisturizer such as urea or ethylene urea may be added as necessary, and in order to have desired physical properties, surfactants, antifoaming agents, antiseptics, antifungal agents, etc. May be added.

  In addition, it can be set as the structure similar to a liquid composition as a water-soluble organic solvent contained in a pigment ink. That is, the water-soluble organic solvent is a water-soluble organic solvent having a difference of 36% or less in water retention in a temperature 23 ° C./relative humidity 45% environment and in a temperature 30 ° C./relative humidity 80% environment. It is preferable to contain a large amount. By doing so, it becomes possible to more effectively suppress curling after the ink is applied to the recording medium.

[Recording method and apparatus]
Examples of the method for applying the liquid composition to the recording medium include a method using an ink jet recording method as in the case of an ink and a method of applying the liquid composition to a recording medium with a roller. Among these, coating with a roller or the like that can be uniformly applied by a recording medium even with a small amount is preferable.

(Inkjet recording device)
FIG. 1 shows an example of an ink jet recording apparatus.
This image forming apparatus employs a serial type ink jet recording system and has the following configuration. In such an image forming apparatus, the recording head 1, a sheet feeding tray 17 for feeding a recording medium (hereinafter also referred to as recording sheet) 19, and a means for applying the liquid composition of the present invention are integrally formed. The paper feed cassette 16 is provided. In addition, there are drive means for reciprocating the recording head in a direction perpendicular to the recording paper conveyance direction, and control means for controlling the drive of these components.

  The recording head 1 is mounted on the carriage 2 so that the surface on which the discharge ports are formed is oriented toward the platen 11. Although not shown, the recording head 1 has the ejection port, a plurality of electrothermal transducers (for example, heating resistance elements) for heating ink, and a substrate that supports the electrothermal transducer. The recording head 1 has an ink cartridge mounted in an upper carriage.

  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) and feeds only the uppermost sheet (recording paper 19) by a separation claw (not shown).

  The separated and fed recording paper 19 is transported along the transport surface of the paper feed cassette 16 and the transport surface of the paper guide 27 by the large-diameter intermediate roller 12 and the small-diameter application roller 6 in pressure contact therewith. Is done. 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. That is, the surface on which the recording paper 19 is recorded 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 recording surface of the recording paper always faces the outside of the image forming apparatus.

  The liquid composition application unit is provided in the paper feed cassette 16. A replenishing tank 22 for supplying the liquid composition 15, an intermediate roller 12 rotatably supported with a part of the peripheral surface immersed in the tank 22, arranged so as to be parallel to the intermediate roller, and intermediate It has the application roller 6 which contacts the roller 12 and rotates 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 liquid composition 15 is supplied to the peripheral surface of the application roller 6 by the supply roller 13, and the liquid composition is applied evenly to the recording surface of the recording paper 19 sandwiched between the application roller 6 and the intermediate roller 12. It is applied by a roller 6.

  In the image forming apparatus, the float 14 is provided in the replenishing tank 22. The float 14 is a substance having a lighter specific gravity than the liquid composition 15. The float 14 floats on the liquid surface of the liquid composition 15 and is a liquid composition containing a reaction component from the outside through a remaining amount display window 21 that is a transparent member. The remaining amount can be confirmed visually.

  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, when the liquid level of the liquid composition or the float 14 reaches the position indicated as “Full”, the state is full. On the other hand, when there is a liquid surface or float 14 of the liquid composition at the position labeled “Add”, it indicates that the liquid composition remains little. Therefore, it can be understood at a glance that the liquid composition 15 should be replenished when the liquid composition 15 is gradually reduced and the float 14 is lowered to the Add line.

  As a method for replenishing the liquid composition, as shown in FIG. 3, the inlet 20 constituted by a rubber member having a cut at the tip of the injector 23 with the paper feed cassette 16 pulled out from the main body of the image forming apparatus. The liquid composition is injected into the replenishing tank 22 by being inserted into the refill tank 22.

  In this way, the recording paper coated with the liquid composition is then transported to the recording unit by a predetermined amount by the main transport roller 7 and the pinch roller 8 in pressure contact therewith, and ink is applied from the recording head 1. Is done. The recording medium 19 fed and recorded 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 liquid composition is applied by a roller or the like, it is possible to effectively destabilize the ink with a small applied amount, and to make a recording, particularly when the viscosity of the liquid composition is higher than the viscosity of the ink. It is preferable because it is also good for fixing property. More specifically, when the viscosity of the liquid composition is higher, the polyvalent metal ions are more likely to stay near the surface of the recording medium, so that the liquid composition is more likely to react effectively with the ink.

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

  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 ejection port surface, and performs capping. It has a configuration. Further, reference numeral 63 denotes an 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 absorber 63 constitute a discharge recovery portion 64, and the blade 61 and the absorber 63 remove moisture, dust, and the like from the discharge port surface. Further, each ink of the recording head, and further, the ink at the discharge port of the liquid composition are sucked by a pump (not shown) through a cap, and the original ink of the recording head, or the ink and liquid composition It constitutes a recovery system unit that restores the original discharge performance of objects.

  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 feed 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 discharge port surface of the recording head 65, 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 and liquid composition set of the present invention is particularly suitable for inkjet recording. As an 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 ink but also the liquid composition of the present invention can be used in these recording methods. In that case, it is preferable that the liquid composition and the ink having the above-described configuration of the present invention have characteristics that enable ejection from the recording head. From the viewpoint of dischargeability from the recording head, it is preferable that the characteristics of these liquids are as follows, for example. Specifically, the viscosity is 1 mPa · s to 15 mPa · s, further 1 mPa · s to 5 mPa · s, and the surface tension is 25 mN / m (dyne / cm) to 50 mN / m (dyne / cm). It is preferable.

(ink cartridge)
FIG. 5 is a view showing an example of a member 45 that supplies a liquid composition that does not contain ink or a color material to the recording head, for example, a cartridge 45 that contains ink or a liquid composition supplied via a tube. . Here, reference numeral 40 denotes an accommodating portion, for example, a bag, in which ink or liquid composition for supply is accommodated, and a rubber stopper 42 is provided at the tip thereof. By inserting a needle (not shown) into the stopper 42, the ink or liquid composition in the bag 40 can be supplied to the head. Reference numeral 44 denotes an absorber for receiving waste ink or waste liquid composition. The container 40 preferably has a liquid contact surface with the ink or liquid composition formed of polyolefin, particularly polyethylene. Such a cartridge preferably has a configuration as shown in FIG. 6, for example. That is, the cartridge is configured to be detachable from the recording head 901 that discharges ink or a liquid composition, and the ink or the liquid composition is supplied to the recording head 901 in a state where the cartridge 45 is mounted on the recording head. It is configured as follows.

  Hereinafter, although it demonstrates more concretely using an Example and a comparative example, this invention is not limited at all by the following Example, unless the summary is exceeded. In the following description, “parts” and “%” are based on mass unless otherwise specified.

[Evaluation of liquid composition]
Each of the liquid compositions of the present invention having the following composition was prepared. As a specific preparation method, the components shown in Table 1 below were mixed, sufficiently stirred and dissolved, and then pressure-filtered with a micro filter (manufactured by Fuji Film) having a pore size of 1 μm to obtain each liquid composition. In Table 1, acetylenol EH is an acetylene glycol ethylene oxide adduct (manufactured by Kawaken Fine Chemicals). In addition, the difference in moisture retention in the table is a value measured under the above conditions.

After applying the liquid compositions 1 to 7 to the recording medium with the application roller shown in FIG. 1, the curl evaluation of the recorded matter and the evaluation of the depositability of the liquid composition were performed by the evaluation methods shown below. At this time, the speed of the roller and the contact pressure of the roller to the recording medium were adjusted so that the amount of the liquid composition applied to the recording medium was 2.4 g / m ² . In addition, Canon PB paper was used as the recording medium.

(1) Curling Evaluation The recorded material was left at a temperature of 24 ° C./relative humidity of 50% immediately after application of the liquid composition (within 1 minute) for 1 hour, 1 day, 2 days, and the curl amount was measured over time. When the recorded paper curls in the concave direction, it is + (plus curl), and when it is curled in the convex direction is-(minus curl), and the distance from the leading edge of the curled paper to the ground contact surface of the paper is measured with a ruler. . The evaluation results are shown in Table 2. The curl criteria are as follows.

(Curl criteria)
AA: Within ± 10 mm A: Greater than ± 10 mm and within ± 25 mm B: Greater than ± 25 mm and within ± 40 mm C: The state where the leading edge of the paper is warped or curled

(2) Precipitation evaluation Each of the liquid compositions 1 to 7 obtained above was weighed in a 5 g petri dish, and the state of the liquid composition was visually observed after being left for 30 days in an environment of temperature 25 ° C./relative humidity 30%. Then, the precipitation property at the time of water evaporation in the liquid composition was evaluated. The obtained results are shown in Table 3.

[Set of liquid composition and ink]
A black (Bk) ink having the following composition was prepared as an ink to be used with the liquid composition described above.

(Bk pigment dispersion)
10 parts of pigment, 25 parts of dispersant and 65 parts of pure water are charged into a batch type vertical sand mill (manufactured by IMEX), filled with 150 parts of 0.3 mm diameter zirconia beads, and dispersed for 5 hours while cooling with water. It was. Note that Monak 880 (manufactured by Cabot) was used as the pigment. The dispersant is an anionic polymer P-1 (styrene / M230G (manufactured by Shin-Nakamura Chemical Co., Ltd.) / Acrylic acid copolymer (copolymerization ratio (mass ratio) = 60/10/30)), acid value 180, An aqueous solution having a weight average molecular weight of 9,000 and a solid content of 10%, a neutralizing agent: potassium hydroxide) was used. Further, this dispersion was centrifuged to remove coarse particles. As a final preparation, a Bk pigment dispersion having a solid content of about 12.5% and a weight average particle size of 110 nm was obtained.

(ink)
The following components were mixed and sufficiently stirred, and then pressure filtered through a micro filter (manufactured by Fuji Film) having a pore size of 3.0 μm to prepare an ink.
・ Bk pigment dispersion 40 parts ・ Glycerin 5 parts ・ Diethylene glycol 5 parts ・ Polyethylene glycol 1000 5 parts ・ Acetylene glycol ethylene oxide adduct 1 part (trade name: acetylenol EH; manufactured by Kawaken Fine Chemical Co., Ltd.)
・ 44 parts of water

The liquid composition 1 prepared above was applied to a PB paper made from Canon so that the application amount was 2.4 g / cm ² using the application roller shown in FIG. Thereafter, the ink obtained above was applied to the Canon PB paper to which the liquid composition 1 was applied using an inkjet recording apparatus 850i (manufactured by Canon). As the recorded image, solid recording (100% duty) having a size of 20 × 25 cm was used. The curled evaluation similar to the above was performed about the obtained recorded matter. The evaluation results are shown in Table 4.

It is a schematic sectional side view which shows an example of an inkjet recording device. FIG. 2 is a front sectional view of a liquid composition remaining amount display unit provided in the ink jet recording apparatus of FIG. 1. FIG. 2 is a schematic cross-sectional side view showing a liquid composition replenishment state in the ink jet recording apparatus of FIG. 1. It is a schematic perspective view which shows an example of an inkjet recording device. It is a longitudinal cross-sectional view which shows an example of an ink cartridge. FIG. 2 is a schematic plan view showing a state where the ink cartridge according to one embodiment is mounted on a recording head. It is a figure which shows the measurement result of the moisture retention power by the environment according to various water-soluble organic compounds. It is a figure which shows the difference of the water | moisture-content retention of various water-soluble organic compounds.

Explanation of symbols

1: Recording head 2: Carriage 3: Paper discharge roller 4: Spur 5: Paper discharge tray 6: Application roller 7: Main transport roller 8: Pinch roller 9: Guide shaft 10: Paper feed roller 11: Platen 12: Intermediate roller 13 : Supply roller 14: Float 15: Liquid composition 16: Paper feed cassette 17: Paper feed tray 18: Spring 19: Recording medium (recording paper)
20: injection port 21: remaining amount display window 22: replenishment tank 23: injection device 27: paper guide 40: bag 42: stopper 44: absorber 45: ink cartridge 51: paper feed unit 52: paper feed roller 53: paper discharge Roller 61: Blade 62: Cap 63: Absorber 64: Discharge recovery unit 65: Recording head 66: Carriage 67: Guide shaft 68: Motor 69: Belt 901: Recording head

Claims (8)

A step of applying an ink containing a coloring material in a dissolved or dispersed state to the recording medium, and destabilizing the dissolved or dispersed state of the coloring material in the ink by contacting the recording medium with the ink A liquid composition used in an image recording method comprising:
The liquid composition includes a polyvalent metal ion, the following compound 1-1, the following compound 1-2, and the following compound 2.
And at least one of the following compounds 2 is a low volatility compound,
And the content based on the total mass of the liquid composition of the following compounds 1-1 X ₁ (wt%), the content based on the total mass of the liquid composition of the following compound 1-2 X ₂ (wt%) and the following A liquid composition characterized in that the content Y (% by mass) of the compound 2 based on the total mass of the liquid composition satisfies the relationship of the following formulas (1), (2) and (3).
(1) 0.1 ≦ (X ₂ + Y) / X ₁ ≦ 2.5
(2) 15% by mass ≦ X ₁ + X ₂
(3) 3% by mass ≦ X ₂ + Y
[Compound 1-1]: The difference between the moisture retention in an environment of temperature 23 ° C./45% relative humidity and the moisture retention in an environment of temperature 30 ° C./relative humidity 80% is 36% or less, and the molecular weight Mw Is a water-soluble polyhydric alcohol or water-soluble amide compound in the range of 100 ≦ Mw ≦ 1,000.
[Compound 1-2]: The difference between the moisture retention in an environment of temperature 23 ° C./45% relative humidity and the moisture retention in an environment of temperature 30 ° C./relative humidity 80% is 36% or less, and the molecular weight Mw Is a water-soluble alkanediol having a range of 100 ≦ Mw ≦ 150 and having OH groups at both ends of the main chain.
[Compound 2]: A water-soluble organic compound other than the colorant and compounds 1-1 and 1-2. Content Y (% by mass) based on the total mass of the liquid composition of Compound 2 is Y <15% by mass,
2. The difference between the moisture retention in the environment of 23 ° C./45% relative humidity and the moisture retention in the environment of 30 ° C./80% relative humidity of the compound 2 is 40% or more. Liquid composition.   The compound 1-1 is a polyhydric alcohol having at least three ether bonds, a polyhydric alcohol having at least three OH groups, and at least one hydrophilic bonding group (hydrogen bonding property other than an OH group or an ether bond). The liquid composition according to claim 1, which is selected from the group consisting of polyhydric alcohols having a binding group). The content X ₁ (mass%) of the compound 1-1, the content X ₂ (mass%) of the compound 1-2 and the content Y (mass%) of the compound 2 are further represented by the following formula (4). The liquid composition according to any one of claims 1 to 3, wherein
(4) 0 <Y / (X ₁ + X ₂ ) ≦ 0.9   The liquid composition according to any one of claims 1 to 4, wherein the water content (% by mass) is 77% by mass or less based on the total mass of the liquid composition. A step of applying an ink containing a coloring material in a dissolved or dispersed state to the recording medium, and destabilizing the dissolved or dispersed state of the coloring material in the ink by contacting the recording medium with the ink A step of applying a liquid composition to be used, and an image recording method comprising an ink and a liquid composition,
A set, wherein the liquid composition is the liquid composition according to any one of claims 1 to 5.   (I) a step of applying an ink containing a coloring material in a dissolved or dispersed state to the recording medium; and (ii) an undissolved or dispersed state of the coloring material in the ink by contacting with the ink. Applying the liquid composition to be stabilized, and in the step (ii), after the fixing of the liquid composition to the recording medium is completed, the image recording method performs the step (i), An image recording method, wherein the liquid composition is the liquid composition according to any one of claims 1 to 5. The image recording method according to claim 7, wherein an application amount of the liquid composition to the recording medium is 0.5 g / m ² or more and 5 g / m ² or less.

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