JP2006088438A - Treatment liquid for inkjet recording, its discharge inspection method, and ink set for inkjet recording - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a treatment liquid for inkjet recording whereby it can be easily inspected whether or not even the colorless transparent or light-colored treatment liquid is normally discharged from a discharging means, and to provide its discharge inspection method and an ink set for inkjet recording. <P>SOLUTION: In the discharge inspection method of the treatment liquid for inkjet recording, at least whether or not the treatment liquid for inkjet recording is normally discharged from the discharging means is inspected at the time of discharging from the discharging means the treatment liquid for inkjet recording which contains a flocculant. The treatment liquid for inkjet recording further contains a luminophor. Discharge inspection is carried out by light emission of the luminophor. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a processing liquid for ink jet recording, a discharge inspection method for the processing liquid for ink jet recording, and an ink set for ink jet recording containing the processing liquid for ink jet recording.

  Inkjet recording devices discharge liquid or molten solid ink from nozzles, slits, porous films, etc., and record on paper, cloth, films, etc. Is being studied. As a method for ejecting ink, a so-called charge control method in which ink is ejected using electrostatic attraction, or a so-called drop-on-demand method (pressure pulse method) in which ink is ejected using vibration pressure of a piezoelectric element. Various methods have been proposed, such as the so-called thermal ink jet method, in which ink is ejected using the pressure generated by the formation and growth of bubbles by high heat, and extremely high definition images can be obtained by these methods. Can do.

The ink used in the ink jet recording apparatus is mainly composed of a solvent, a color material, and an additive. With regard to such inks, (1) a uniform image with high resolution and high density without bleeding and fogging can be obtained, and (2) no clogging due to ink drying at the nozzle tip, and always ejection response. There are required characteristics such as good ejection stability, (3) high drying properties of ink on paper, and (4) high image fastness.
Furthermore, in obtaining high-definition full-color printing, it is important to obtain a high image density, no image blur, and no blur between colors.

  Against this background, in recent inkjet recording, recording methods using a liquid composition other than ink (hereinafter referred to as “treatment liquid”) are becoming popular with the aim of further improving ejection stability and image quality. The treatment liquid is intended to improve the penetrability, drying, and storage stability of the image after printing.Since many of the treatment liquid is colorless, whether or not the treatment liquid can be normally ejected from the nozzle depends on the ink (normal It was difficult to discriminate by the method of printing a nozzle check pattern on paper as in the case of inspection with ink).

  Various methods have been proposed as a method for inspecting whether or not such processing liquid is normally discharged. For example, Patent Document 1 below uses a discharge inspection film in which a recording treatment liquid receiving layer in which a dye compound that changes color due to pH change such as bromothymol blue is dispersed, and the recording treatment liquid is placed on the film. A method is disclosed in which the landing position of the recording processing liquid is visually confirmed by discharging and changing the color to determine the quality of the discharge state. This technique uses an acid-base reaction between the processing liquid and the paper, and the processing liquid is limited to colorless and transparent.

  In Patent Document 2 below, a change in the transparent ink droplet and the light reflectance around the transparent ink droplet is detected, and the actual position of the transparent ink droplet is determined according to the detected change in the light reflectance. A technique for detecting a transparent ink drop on a medium is disclosed. This method is disadvantageous in terms of cost because it requires a separate means for detecting the reflectance.

Further, in Patent Document 3 below, as a discharge inspection method for a processing liquid (pretreatment liquid) containing a pigment ink flocculant, a test liquid that performs a color reaction on the pigment ink flocculant is recorded for inspection. Discharge inspection of processing liquid that is applied to the recording surface of the medium, and the recording liquid is ejected and adhered to the recording surface to which the inspection liquid is applied, and the color of the recording surface is visually inspected. A method is disclosed. This discharge inspection method uses a color reaction of the metal salt between the processing liquid and the paper coated with the inspection liquid, and is limited to the one containing the metal salt as the processing liquid. The liquid is limited to a pretreatment liquid that is ejected and adhered before ink jet recording ink, and is not a general-purpose method.
JP 2000-168106 A JP 2003-159783 A JP 2003-326828 A

An object of the present invention is to solve the conventional problems and achieve the following objects. That is,
An object of the present invention is to provide an inkjet recording treatment liquid capable of easily inspecting whether or not it is a colorless transparent or light-colored treatment liquid being normally ejected from the ejection means, an ejection inspection method thereof, and an inkjet recording To provide an ink set.

Means for solving the problems are as follows. That is,
<1> An inkjet recording treatment liquid that inspects whether or not the inkjet recording treatment liquid is normally ejected from the ejection means when ejecting the inkjet recording treatment liquid containing at least the flocculant from the ejection means. The inkjet recording treatment liquid further comprises a phosphor, and the ejection test is performed by light emission of the phosphor. Inspection method.

<2> The discharge inspection method for a treatment liquid for ink jet recording according to <1>, wherein the phosphor is an organic fluorescent material or an inorganic phosphorescent material.

<3> The method for inspecting ejection of a treatment liquid for inkjet recording according to <1>, wherein the flocculant is a pH adjuster or a polyvalent metal salt.

<4> The inkjet recording treatment liquid according to <1>, wherein the inkjet recording treatment liquid is printed on a recording medium, and ejection inspection is performed by applying excitation energy to the recording medium. This is a discharge inspection method.

<5> The method for inspecting the ejection of a processing liquid for ink jet recording according to <1>, wherein the recording medium on which the processing liquid for ink jet recording is printed in an image-like manner is observed in an environment of 30 lux or less. It is.

<6> A processing liquid for ink jet recording, comprising at least a flocculant and a phosphor.

<7> An ink set for ink jet recording, comprising at least an ink for ink jet recording containing a coloring material and a treatment liquid for ink jet recording containing a flocculant and a phosphor.

  According to the present invention, it is possible to easily inspect whether or not a colorless transparent or light-colored treatment liquid is normally ejected from the ejection means and to improve the color developability of the ink used together. A recording treatment liquid, a discharge inspection method thereof, and an ink set for inkjet recording can be provided.

  Hereinafter, the processing liquid for inkjet recording of the present invention (hereinafter sometimes simply referred to as “processing liquid”) will be described.

<Inkjet recording treatment liquid>
The processing liquid for inkjet recording of the present invention contains at least a flocculant and a phosphor, and further contains a water-soluble solvent and water. Hereinafter, each component will be described.

[Flocculant]
As the flocculant used in the treatment liquid of the present invention, an inorganic electrolyte, an organic amine compound, an organic acid, or the like is used, and among them, an inorganic electrolyte is preferable. More specifically, as the inorganic electrolyte, a pH adjuster or a polyvalent metal salt can be preferably used.

Among inorganic electrolytes, specific examples of pH adjusters include 2-pyrrolidone-5-carboxylic acid, 4-methyl-4-pentanolide-3-carboxylic acid, furan carboxylic acid, 2-benzofuran carboxylic acid, and 5-methyl. 2-furancarboxylic acid, 2,5-dimethyl-3-furancarboxylic acid, 2,5-furandicarboxylic acid, 4-butanolide-3-carboxylic acid, 3-hydroxy-4-pyrone-2,6-dicarboxylic acid 2-pyrone-6-carboxylic acid, 4-pyrone-2-carboxylic acid, 5-hydroxy-4-pyrone-5-carboxylic acid, 4-pyrone-2,6-dicarboxylic acid, 3-hydroxy-4-pyrone -2,6-dicarboxylic acid, thiophenecarboxylic acid, 2-pyrrolecarboxylic acid, 2,3-dimethylpyrrole-4-carboxylic acid, 2,4,5-trimethylpyrrole-3-propyl Pionic acid, 3-hydroxy-2-indolecarboxylic acid, 2,5-dioxo-4-methyl-3-pyrroline-3-propionic acid, 2-pyrrolidinecarboxylic acid, 4-hydroxyproline, 1-methylpyrrolidine-2- Carboxylic acid, 5-carboxy-1-methylpyrrolidine-2-acetic acid, 2-pyridinecarboxylic acid, 3-pyridinecarboxylic acid, 4-pyridinecarboxylic acid, pyridinedicarboxylic acid, pyridinetricarboxylic acid, pyridinepentacarboxylic acid, 1,2 , 5,6-tetrahydro-1-methylnicotinic acid, 2-quinolinecarboxylic acid, 4-quinolinecarboxylic acid, 2-phenyl-4-quinolinecarboxylic acid, 4-hydroxy-2-quinolinecarboxylic acid, 6-methoxy-4 -Quinoline carboxylic acid, potassium hydrogen phthalate, potassium dihydrogen phosphate, boric acid, Sodium phosphate, potassium citrate, tetrasodium boron, tartaric acid, lactic acid, ammonium chloride, sodium hydroxide, potassium hydroxide, hydrochloric acid, derivatives of these compounds, or compounds such as salts thereof.
Preferably, pyrrolidone carboxylic acid, pyrone carboxylic acid, pyrrole carboxylic acid, furan carboxylic acid, pyridine carboxylic acid, coumaric acid, thiophene carboxylic acid, nicotinic acid, potassium dihydrogen citrate, succinic acid, tartaric acid, lactic acid, hydrogen phthalate Potassium or a derivative of these compounds or a salt thereof. More preferably, it is pyrrolidone carboxylic acid, pyrone carboxylic acid, furan carboxylic acid, coumaric acid, or a compound derivative thereof, or a salt thereof.

  On the other hand, among the inorganic electrolytes, as the polyvalent metal salt, alkali metal ions such as lithium ions, sodium ions and potassium ions, and aluminum ions, barium ions, calcium ions, copper ions, iron ions, magnesium ions, manganese ions, Polyvalent metal ions such as nickel ion, tin ion, titanium ion, zinc ion, hydrochloric acid, odorous acid, hydroiodic acid, sulfuric acid, nitric acid, phosphoric acid, thiocyanic acid, and acetic acid, oxalic acid, lactic acid, fumaric acid, fumaric acid Examples thereof include organic carboxylic acids such as acid, citric acid, salicylic acid and benzoic acid, and salts of organic sulfonic acid.

  Specific examples include lithium chloride, sodium chloride, potassium chloride, sodium bromide, potassium bromide, sodium iodide, potassium iodide, sodium sulfate, potassium nitrate, sodium acetate, potassium oxalate, sodium citrate, potassium benzoate and the like. Alkali metal salts and aluminum chloride, aluminum bromide, aluminum sulfate, aluminum nitrate, sodium aluminum sulfate, potassium aluminum sulfate, aluminum acetate, barium chloride, barium bromide, barium iodide, barium oxide, barium nitrate, thiocyanate Barium acid, calcium chloride, calcium bromide, calcium iodide, calcium nitrite, calcium nitrate, calcium dihydrogen phosphate, calcium thiocyanate, calcium benzoate, calcium acetate, salicyl Calcium, calcium tartrate, calcium lactate, calcium fumarate, calcium citrate, copper chloride, copper bromide, copper sulfate, copper nitrate, copper acetate, iron chloride, iron bromide, iron iodide, iron sulfate, iron nitrate, oxalic acid Iron, iron lactate, iron fumarate, iron citrate, magnesium chloride, magnesium bromide, magnesium iodide, magnesium sulfate, magnesium nitrate, magnesium acetate, magnesium lactate, manganese chloride, manganese sulfate, manganese nitrate, manganese dihydrogen phosphate , Manganese acetate, manganese salicylate, manganese benzoate, manganese lactate, nickel chloride, nickel bromide, nickel sulfate, nickel nitrate, nickel acetate, tin sulfate, titanium chloride, zinc chloride, zinc bromide, zinc sulfate, zinc nitrate, thiocyanate Examples thereof include polyvalent metal salts such as zinc acid and zinc acetate.

  Examples of the organic amine compound include primary, secondary, tertiary and quaternary amines and salts thereof. Specific examples include tetraalkylammonium salts, alkylamine salts, benzalkonium salts, alkylpyridium salts, imidazolium salts, polyamines, etc., for example, isopropylamine, isobutylamine, t-butylamine, 2-ethylhexylamine. , Nonylamine, dipropylamine, diethylamine, trimethylamine, triethylamine, dimethylpropylamine, ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, tetraethylenepentamine, diethanolamine, diethylethanolamine, triethanolamine, tetramethylammonium chloride, tetraethylammonium Bromide, dihydroxyethyl stearylamine, 2-heptadecenyl-hydroxyethyl Imidazoline, lauryldimethylbenzylammonium chloride, cetylpyridinium chloride, stearamide methylpyridium chloride, diallyldimethylammonium chloride polymer, diallylamine polymer, monoallylamine polymer, and onium salts such as sulfonium salts and phosphonium salts of these compounds, Or phosphoric acid ester etc. are mentioned.

  Examples of the organic acid include the styrene-styrene sulfonic acid copolymer, styrene-maleic acid copolymer, styrene-methacrylic acid copolymer, styrene-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer, vinyl naphthalene. -Methacrylic acid copolymer, vinylnaphthalene-acrylic acid copolymer, alkyl acrylate ester-acrylic acid copolymer, methacrylic acid alkyl ester-methacrylic acid, styrene-alkyl methacrylate-methacrylic acid copolymer, styrene- Examples include acrylic acid alkyl ester-acrylic acid copolymer, styrene-methacrylic acid phenyl ester-methacrylic acid copolymer, and styrene-methacrylic acid cyclohexyl ester-methacrylic acid copolymer.

  In the present invention, the flocculant may be used alone or in combination of two or more. The addition amount of the flocculant in the treatment liquid for inkjet recording is preferably 0.01% by mass or more and 30% by mass or less. More preferably, it is 0.1 mass% or more and 15 mass% or less, More preferably, it is 0.25 mass% or more and 10 mass% or less. When the addition amount of the flocculant in the treatment liquid is less than 0.01% by mass, the color material may not sufficiently aggregate at the time of ink contact, and the optical density, bleeding, and intercolor bleeding may deteriorate. When the added amount exceeds 30% by mass, the jetting characteristics are deteriorated, and the liquid may not be jetted normally.

[Fluorescent phosphor]
As described above, the ink jet recording treatment liquid of the present invention contains a phosphor. Here, the phosphor may exist in a dissolved state or in a dispersed state. The phosphor is a substance that emits fluorescence or phosphorescence. Such a phosphor is (A) an organic fluorescent substance or the like, such as ultraviolet rays or infrared rays (sensitive to the phosphor). There are those that emit fluorescence or phosphorescence when irradiated with excitation energy of a wavelength, or (B) an inorganic phosphorescent substance that emits phosphorescence in the dark after absorbing light. Hereinafter, each phosphor will be described.

  (A) As the substance that emits fluorescence or phosphorescence when irradiated with excitation energy, an organic fluorescent substance is preferable, and an organic fluorescent dye is particularly preferable in terms of solubility. Examples of organic fluorescent dyes include C.I. I. Fluorescent Brightening Agent 14, 24, 30, 32, 52, 54, 69, 79, 84, 85, 86, 87, 90, 104, 112, 113, 114, 119, 121, 134, 135, 152, 166, 167, 168, 169, 191, 192, 201, 204, 214, 216, 217, 218, 223, 226, 229, 234, 236, 239, 240, 242, 257, 260, 271, 290, 310, 311, 312, 313, 314, 315, C.I. I. Basic Red 1, 2, 9, 12, 13, 14, 17, C.I. I. Basic Violet 1, 3, 7, 10, 11, 14, C.I. I. Basic Yellow 9, 35, 40, 44, 95, C.I. I. Basic Blue 7, 45, C.I. I. Acid Red 51, 52, 92, 94, C.I. I. Acid Blue 9, C.I. I. Acid Yellow 7, 23, C.I. I. Acid Red 52, 87, 92, C.I. I. Acid Black 2 and the like. I. Basic Yellow 40, 44, C.I. I. Fluorescent Brightening Agent 30 is preferred.

(B) As a phosphorescent material that emits phosphorescence in the dark after absorbing light, the phosphorescent material absorbs and accumulates light such as sunlight and fluorescent lamps, and gradually emits and emits light in the dark. This is a material that has the property of repeatedly absorbing, accumulating, and emitting light for a long period of time. As the inorganic phosphorescent substance, an alkaline earth aluminate containing a rare earth element can be suitably used.
For example, composition of Al ₂ O ₃ , CaO, SrO, Ba ₂ O ₃ or M · Al · O (eg, MAl ₂ O ₄ , M is a metal atom of Group 2 of the periodic table such as calcium, strontium, barium) Mother crystal + rare earth element (europium (Eu), dysprosium (Dy), terbium (Tb), samarium (Sm)) and the like.
In addition, the color at the time of light emission changes with kinds of rare earth elements, for example, it light-emits in the following colors, respectively.
Europium ... red (615nm)
Dysprosium ... Yellow green (574nm)
Terbium ... Green (545nm)
Samarium red (643nm)

  In the present invention, the phosphor may be used alone or in combination of two or more. The addition amount of the phosphor in the inkjet recording treatment liquid is preferably 0.1% by mass or more and 5% by mass or less. More preferably, they are 0.5 mass% or more and 3 mass% or less, More preferably, they are 0.1 mass% or more and 2 mass% or less. If the amount of phosphor added in the treatment liquid is less than 0.01% by mass, the amount of emitted light may be insufficient and may not be easily visible, while if the amount added exceeds 5% by mass. In some cases, even if added more, the difference is effectively eliminated.

  In the present invention, since the phosphor is ejected from a fine ejection means such as a nozzle, it is preferable that the phosphor has a high solubility or a small dispersed particle size. Specifically, the dispersed particle diameter is preferably 0.01 to 5 μm, and more preferably 0.01 to 3 μm.

[Water-soluble solvent]
Examples of the water-soluble solvent used in the inkjet recording treatment liquid include polyhydric alcohols, polyhydric alcohol derivatives, nitrogen-containing solvents, alcohols, and sulfur-containing solvents. Specific examples of polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,5-pentanediol, 1,2,6-hexanetriol, and glycerin. Examples of polyhydric alcohol derivatives include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, and diglycerin. Examples include ethylene oxide adducts. Examples of nitrogen-containing solvents include pyrrolidone, N-methyl-2-pyrrolidone, cyclohexyl pyrrolidone, and triethanolamine. Examples of alcohols include alcohols such as ethanol, isopropyl alcohol, butyl alcohol, and benzyl alcohol. Thiodiethanol, thiodiglycerol, sulfolane, dimethyl sulfoxide and the like. In addition, propylene carbonate, ethylene carbonate, or the like can be used.

  The water-soluble solvent used in the present invention may be used alone or in combination of two or more. The content of the water-soluble organic solvent is 1 to 60% by mass, preferably 5 to 40% by mass. When the amount of the water-soluble organic solvent in the liquid is less than 1% by mass, a sufficient optical density may not be obtained. Conversely, when the amount is more than 60% by mass, the viscosity of the liquid increases. The liquid ejection characteristics may become unstable.

[Color material]
In the ink jet recording treatment liquid of the present invention, a coloring material may be included as desired. The coloring material is preferably a dye, a pigment having a sulfonic acid or a sulfonate on the surface, an anionic self-dispersing pigment, or a cationic self-dispersing pigment. It is considered that these color materials tend to hardly aggregate in the acidic region. By using such a color material, the storage stability of the treatment liquid is improved. As the dye, the pigment having a sulfonic acid or sulfonate salt on the surface, and the self-dispersing pigment, the same materials as the ink coloring material described later can be used.

  When a color material is used for the treatment liquid, the volume average particle diameter of the color material particles is preferably 30 nm or more and 250 nm or less. More preferably, they are 50 nm or more and 200 nm or less, More preferably, they are 75 nm or more and 175 nm or less. When the volume average particle diameter of the particles in the liquid is less than 30 nm, the optical density may be low. On the other hand, when it exceeds 250 nm, the storage stability may not be ensured.

(Preferred physical properties of processing liquid for inkjet recording)
The surface tension of the treatment liquid is preferably 20 mN / m or more and 45 mN / m or less. More preferably, it is 20 mN or more and 39 mN / m or less, More preferably, it is 25 mN / m or more and 35 mN / m or less. If the surface tension is less than 20 mN / m, the liquid may overflow on the nozzle surface and printing may not be performed normally. On the other hand, if it exceeds 45 mN / m, the permeability may be slow and the drying time may be slow.

  The viscosity of the treatment liquid is preferably 1.2 mPa · s or more and 8.0 mPa · s or less, more preferably 1.5 mPa · s or more and less than 6.0 mPa · s, and further preferably 1.8 mPa · s or more and 4 or more. Less than 5 mPa · s. When the viscosity of the treatment liquid is greater than 8.0 mPa · s, the dischargeability may be reduced. On the other hand, when it is smaller than 1.2 mPa · s, the long-term jetting property may deteriorate.

  Water is added in a range that achieves the above surface tension and viscosity. The amount of water added is not particularly limited, but is preferably 10% by mass or more and 99% by mass or less, and more preferably 30% by mass or more and 80% by mass or less with respect to the entire treatment liquid.

<Ink set for inkjet recording>
The ink set for ink jet recording of the present invention (hereinafter sometimes simply referred to as “ink”) includes an ink for ink jet recording having a color material and a treatment liquid for ink jet recording containing an aggregating agent and a phosphor. It is characterized by containing. That is, the ink set for ink jet recording of the present invention contains the ink for ink jet recording and the treatment liquid for ink jet recording of the present invention described above. Hereinafter, since the inkjet recording treatment liquid is as described above, the description thereof will be omitted, and the inkjet recording ink will be described first.

  The ink for ink jet recording according to the present invention contains at least a coloring material, and further contains a water-soluble solvent, a polymer substance, and water. Hereinafter, each component will be described in detail.

[Color material]
The coloring material used in the ink according to the present invention may be either a dye or a pigment, but a pigment is particularly preferable. This is considered to be because the pigment is more likely to aggregate when mixed with the treatment liquid than the dye. Among the pigments, a pigment in which the pigment is dispersed with a polymer dispersant, a self-dispersible pigment, and a pigment coated with a resin are preferable.

  As the pigment used in the present invention, either an organic pigment or an inorganic pigment can be used. Examples of the black pigment include carbon black pigments such as furnace black, lamp black, acetylene black, and channel black. In addition to black, cyan, magenta and yellow primary pigments, special color pigments such as red, green, blue, brown and white, metallic luster pigments such as gold and silver, colorless or light body pigments, plastic pigments, etc. May be used. In addition, particles having silica or alumina, polymer beads, or the like as a core, and dyes or pigments fixed on the surface thereof, insoluble lakes of dyes, colored emulsions, colored latexes, and the like can also be used as pigments. Furthermore, a pigment newly synthesized for the present invention may be used.

  Specific examples of the pigment used in the present invention include, for example, Raven7000, Raven5750, Raven5250, Raven5000 ULTRAII, Raven3500, Raven2000, Raven1500, Raven1250, Raven1125, Raven1190, Raven1190, Raven1190, Raven1190, Raven1190, Raven1190 (Manufactured by Columbian Carbon), Regal 400R, Regal 330R, Regal 660R, Mogu L, Black Pearls L, Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 300, Monarch 1400 (manufactured by Cabot Corporation), Color Black FW1, Color Black FW2, Color Black FW2V, Color Black FW200, Color Black S150, Color Black S150, Color Black S160, Color Black S160, Color Black S150, Color Black S150, Color Black S150, Color Black S150 , Printex 140U, Printex 140V, Special Black 6, Special Black 5, Special Black 4A, Special Black 4 (manufactured by Degussa), No. 25, no. 33, no. 40, no. 47, no. 52, no. 900, no. 2300, MCF-88, MA600, MA7, MA8, MA100 (manufactured by Mitsubishi Chemical Corporation) and the like can be mentioned, but are not limited thereto.

  Examples of cyan pigments include C.I. I. Pigment Blue-1, -2, -3, -15, -15: 1, -15: 2, -15: 3, -15: 4, -16, -22, -60, and the like. It is not limited.

  Examples of the magenta color pigment include C.I. I. Pigment Red-5, -7, -12, -48, -48: 1, -57, -112, -122, -123, -146, -168, -184, -202, and the like. It is not limited.

  Examples of yellow pigments include C.I. I. Pigment Yellow-1, -2, -3, -12, -13, -14, -16, -17, -73, -74, -75, -83, -93, -95, -97, -98, -114, -128, -129, -138, -151, -154, -180, and the like, but are not limited thereto.

The pigment that can be self-dispersed in water used in the present invention refers to a pigment that has many water-solubilizing groups on the pigment surface and can be stably dispersed in water without the presence of a polymer dispersant. Specifically, it can be self-dispersed in water by subjecting ordinary so-called pigments to surface modification treatments such as acid / base treatment, coupling agent treatment, polymer graft treatment, plasma treatment, oxidation / reduction treatment, etc. Pigments are obtained.
Examples of the pigment that can be self-dispersed in water include a pigment obtained by subjecting the above pigment to surface modification treatment, as well as Cab-o-jet-200, Cab-o-jet-250, Cab- Commercially available self-dispersing products such as o-jet-260, Cab-o-jet-270, Cab-o-jet-300, IJX-444, IJX-55, Microjet Black CW-1, CW-2 manufactured by Orient Chemical Co., Ltd. Pigments can also be used.

The color material used in the ink, which is a self-dispersing pigment, is preferably a color material containing a carboxylic acid group as a functional group on the surface thereof. It is presumed that the carboxylic acid group has a small degree of dissociation, and therefore it is easy to obtain a sufficient cohesive force.
When the color material used in the ink is a color material having a sulfonic acid group on its surface, it is preferable to add a polymer compound having a carboxylic acid group in addition to the color material. Since the color material having a sulfonic acid group on the surface is less likely to aggregate, optical density, bleeding, and intercolor bleeding may not be improved. On the other hand, when a polymer compound having a carboxylic acid group is added, insolubilization of the polymer compound occurs when the two liquids are mixed. At this time, since the pigment is incorporated into the polymer compound and aggregates, it is presumed that optical density, bleeding, and intercolor bleeding are improved.

  Furthermore, a pigment coated with a resin can be used as a color material. This is called a microcapsule pigment, and not only commercially available microcapsule pigments manufactured by Dainippon Ink and Chemicals, Inc., or Toyo Ink, but also microcapsule pigments produced for the present invention may be used. it can.

  On the other hand, the dye used in the present invention may be either a water-soluble dye or a disperse dye. Specific examples of water-soluble dyes include C.I. I. Direct Black-2, -4, -9, -11, -17, -19, -22, -32, -80, -151, -154, -168, -171, -194, -195, C.I. I. Direct Blue-1, -2, -6, -8, -22, -34, -70, -71, -76, -78, -86, -112, -142, -165, -199, -200, -201, -202, -203, -207, -218, -236, -287, -307, C.I. I. Direct Red-1, -2, -4, -8, -9, -11, -13, -15, -20, -28, 31, -33, -37, -39, -51, -59, -62, -63, -73, -75, -80, -81, -83, -87, -90, -94, -95, -99, -101, -110, -189, -227, C.I. I. Direct Yellow-1, −2, −4, −8, −11, −12, −26, −27, −28, −33, −34, −41, −44, −48, −58, −86, -87, -88, -132, -135, -142, -144, -173, C.I. I. Food Black-1, -2, C.I. I. Acid Black-1, -2, -7, -16, -24, -26, -28, 31-1, -48, -52, -63, -107, -112, -118, -119, -121, -156, -172, -194, -208, C.I. I. Acid Blue-1, −7, −9, −15, −22, −23, −27, −29, −40, −43, −55, −59, −62, −78, −80, −81, -83, -90, -102, -104, -111, -185, -249, -254, C.I. I. Acid Red-1, -4, -8, -13, -14, -15, -18, -21, -26, -35, -37, -52, -110, -144, -180, -249, -257, -289, C.I. I. Acid Yellow-1, −3, −4, −7, −11, −12, −13, −14, −18, −19, −23, −25, −34, −38, −41, −42 -44, -53, -55, -61, -71, -76, -78, -79, -122, and the like.

  Specific examples of the disperse dye include C.I. I. Disperse Yellow-3, -5, -7, -8, -42, -54, -64, -79, -82, -83, -93, -100, -119, -122, -126, -160, -184: 1, -186, -198, -204, -224, C.I. I. Disperse Orange-13, -29, -31: 1, -33, -49, -54, -66, -73, -119, -163, C.I. I. Disperse Red-1, -4, -11, -17, -19, -54, -60, -72, -73, -86, -92, -93, -126, -127, -135, -145, -154, -164, -167: 1, -177, -181, -207, -239, -240, -258, -278, -283, -311, -343, -348, -356, -362, C. I. Disperse Violet-33, C.I. I. Disperse Blue-14, -26, -56, -60, -73, -87, -128, -143, -154, -165, -165: 1, -176, -183, -185, -201,- 214, -224, -257, -287, -354, -365, -368, C.I. I. Disperse Green-6: 1, -9 etc. are mentioned.

The volume average particle diameter of the colorant particles in the ink is preferably 30 nm or more and 250 nm or less. The volume average particle diameter of the color material particles refers to the particle diameter of the color material itself or, if an additive such as a dispersant is attached to the color material, the particle diameter to which the additive is attached. In the present invention, a Microtrac UPA particle size analyzer (Leeds & Northrup) was used as a measurement device for the average particle size. The measurement was performed according to a predetermined method with 4 ml of ink placed in a measurement cell. As parameters input at the time of measurement, ink viscosity was used as the viscosity, and pigment density was used as the density of the dispersed particles.
A more preferable volume average particle size is 50 nm or more and 200 nm or less, and further preferably 75 nm or more and 175 nm or less. When the volume average particle diameter of the particles in the liquid is less than 30 nm, the optical density may be low. On the other hand, when it exceeds 250 nm, the storage stability may not be ensured.

  The color material used in the present invention is preferably used in the range of 0.1% by mass or more and 20% by mass or less, and preferably used in the range of 1% by mass or more and 10% by mass or less with respect to the total mass of the ink. More preferred. When the amount of the color material in the liquid is less than 0.1% by mass, a sufficient optical density may not be obtained. When the amount of the color material is more than 20% by mass, the liquid ejection characteristics are poor. It may become stable.

[Polymer substance]
As the polymer substance used in the ink, either a water-soluble resin or a water-insoluble resin can be used, and any nonionic compound, anionic compound, cationic compound, or amphoteric compound may be used. The polymer substance is used to disperse the pigment or to promote the aggregation of the pigment.

The polymer material is preferably selected in consideration of the affinity with the pigment, the cohesiveness of the polymer material itself, and the like based on the acid value and the like. Specifically, it is preferable that the polymer substance has an acid value of 30 KOH mg / g or more and less than 150 KOH mg / g, or an acid value of 150 KOH mg / g or more and a neutralization degree of 80% or less. When the acid value of the polymer compound is 30 KOH mg / g or more and less than 150 KOH mg / g, the acid value is more preferably 50 to 120 KOH mg / g, and still more preferably 70 to 120 KOH mg / g. When the acid value is less than 30 KOHmg / g, the jetting stability may be lowered. On the other hand, when the acid value of the polymer compound is 150 KOHmg / g or more and the degree of neutralization is 80% or less, more preferably, the acid value is 200 to 400 KOH / mg and the degree of neutralization is 50 to 80%. Preferably, the acid value is 200 to 300 KOH / mg, and the degree of neutralization is 60 to 80%. When the acid value is 200 KOHmg / g or more and the degree of neutralization exceeds 80%, the viscosity of the ink may increase and ejection may not be performed normally.
By using a high acid value polymer substance or a high acid value polymer substance with a low degree of neutralization, it becomes possible to reduce the amount of water-soluble groups of the polymer compound, and aggregation with weak cohesive force This is considered to be because a sufficiently large cohesive force can be obtained even when combined with an agent.

A preferred example of the polymer substance selected in consideration of these physical properties includes a polymer compound containing a carboxylic acid group. This is presumed to be due to the fact that the dissociation degree of the carboxylic acid group is small, so that aggregation by the flocculant is effectively promoted.
Although the preferable specific example of such a polymeric substance is given, this invention is not restrict | limited to these. Examples of the polymer substance include a copolymer of monomers having an α, β-ethylenically unsaturated group. Examples of monomers having an α, β-ethylenically unsaturated group include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, itaconic acid monoester, maleic acid, maleic acid monoester, fumaric acid, fumaric acid monoester, Vinyl sulfonic acid, styrene sulfonic acid, sulfonated vinyl naphthalene, vinyl alcohol, acrylamide, methacryloxyethyl phosphate, bismethacryloxyethyl phosphate, methacryloxyethyl phenyl acid phosphate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, styrene, α-methyl Styrene derivatives such as styrene and vinyltoluene, vinylcyclohexane, vinylnaphthalene, vinylnaphthalene derivatives, alkyl acrylates, phenyl acrylates Ether, alkyl methacrylate, phenyl methacrylate, methacrylic acid cycloalkyl ester, crotonic acid alkyl ester, itaconic acid dialkyl esters, maleic acid dialkyl ester and the like.

  A copolymer obtained by copolymerizing a single monomer or a plurality of monomers having the α, β-ethylenically unsaturated group is used as a preferred polymer material of the present invention. Specifically, styrene-styrene sulfonic acid copolymer, styrene-maleic acid copolymer, styrene-methacrylic acid copolymer, styrene-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer, vinyl naphthalene- Methacrylic acid copolymer, vinyl naphthalene-acrylic acid copolymer, alkyl acrylate ester-acrylic acid copolymer, methacrylic acid alkyl ester-methacrylic acid, styrene-alkyl methacrylate-methacrylic acid copolymer, styrene-acrylic Examples include acid alkyl ester-acrylic acid copolymer, styrene-methacrylic acid phenyl ester-methacrylic acid copolymer, and styrene-methacrylic acid cyclohexyl ester-methacrylic acid copolymer.

  The polymer substance used in the present invention preferably has a weight average molecular weight of 2,000 to 15,000. When the molecular weight of the high molecular weight material is less than 2,000, the pigment may not be stably dispersed. On the other hand, when the molecular weight exceeds 15,000, the viscosity of the liquid may increase and the discharge performance may deteriorate. is there. A more preferred weight average molecular weight is 3,500 to 10,000.

  The polymer substance added to the liquid is preferably in the range of 0.01% by mass to 10% by mass. When the addition amount exceeds 10% by mass, the liquid viscosity increases, and the liquid ejection characteristics may become unstable. On the other hand, when the addition amount is less than 0.01% by mass, the dispersion stability of the pigment may be lowered. The addition amount of the polymer substance is more preferably 0.05% by mass to 7.5% by mass, and still more preferably 0.1% by mass to 5% by mass.

[Water-soluble solvent]
As the water-soluble solvent used in the ink in the present invention, polyhydric alcohols, polyhydric alcohol derivatives, nitrogen-containing solvents, alcohols, sulfur-containing solvents and the like are used. Specific examples of polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,5-pentanediol, 1,2,6-hexanetriol, and glycerin. Examples of polyhydric alcohol derivatives include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, and diglycerin. Examples include ethylene oxide adducts. Examples of nitrogen-containing solvents include pyrrolidone, N-methyl-2-pyrrolidone, cyclohexyl pyrrolidone, and triethanolamine. Examples of alcohols include alcohols such as ethanol, isopropyl alcohol, butyl alcohol, and benzyl alcohol. Thiodiethanol, thiodiglycerol, sulfolane, dimethyl sulfoxide and the like. In addition, propylene carbonate, ethylene carbonate, or the like can be used.

  The water-soluble solvent used in the present invention may be used alone or in combination of two or more. The content of the water-soluble solvent is 1 to 60% by mass, preferably 5 to 40% by mass. When the amount of the water-soluble solvent in the liquid is less than 1% by mass, a sufficient optical density may not be obtained. Conversely, when the amount is more than 60% by mass, the viscosity of the liquid increases, The liquid ejection characteristics may become unstable.

(Preferred physical properties of ink)
The surface tension of the ink is preferably 20 mN / m or more and 60 mN / m or less. More preferably, it is 20 mN or more and 45 mN / m or less, More preferably, it is 25 mN / m or more and 35 mN / m or less. If the surface tension is less than 20 mN / m, the liquid may overflow on the nozzle surface and printing may not be performed normally. On the other hand, if it exceeds 60 mN / m, the permeability may be slow and the drying time may be slow.

  The viscosity of the ink is preferably from 1.2 mPa · s to 8.0 mPa · s, more preferably from 1.5 mPa · s to less than 6.0 mPa · s, still more preferably from 1.8 mPa · s to 4. It is less than 5 mPa · s. When the viscosity of the ink and the treatment liquid is greater than 8.0 mPa · s, the dischargeability may be reduced. On the other hand, when it is smaller than 1.2 mPa · s, the long-term jetting property may deteriorate.

  In addition to the above essential components, water is added to the ink in a range that achieves the preferred surface tension and viscosity. The amount of water to be added is not particularly limited, but is preferably 10% by mass or more and 99% by mass or less, and more preferably 30% by mass or more and 80% by mass or less with respect to the entire ink.

  In the present invention, when the ink is alkaline and the treatment liquid is an acidic combination, the pH of the ink is 7.5 or more and 10.5 or less, and the pH of the treatment liquid is 2.5 or more and 7.0 or less. It is preferable. On the other hand, when the ink is acidic and the treatment liquid is an alkaline combination, the pH of the ink is preferably 2.5 or more and 7.0 or less, and the pH of the treatment liquid is preferably 7.5 or more and 10.5 or less. . More preferably, the pH of the alkaline liquid is preferably 7.5 or more and 10.0 or less, and more preferably 8.0 or more and 9.5 or less. On the other hand, as an acidic liquid, a preferable pH range is 3.0 or more and 7.0 or less, and more preferably 3.5 or more and 6.0 or less.

If the pH of the acidic liquid is less than 2.5, the ink flow path component of the print head may be dissolved, causing the print head to fail. On the other hand, when the pH of the acidic liquid exceeds 7.0, the color material may not sufficiently aggregate at the time of ink contact, and the optical density, bleeding, and intercolor bleeding may deteriorate.
When the pH of the alkaline liquid is less than 7.5, the long-term jetting property of the liquid may be lowered. When the pH exceeds 10.5, the ink flow path component of the print head is dissolved, and the print head May be damaged.

  Furthermore, since the ink set for ink jet recording of the present invention contains the processing liquid for ink jet recording of the present invention described above, not only the discharge inspection of the processing liquid can be easily performed but also the color development of the printed image is improved. The effect of doing. This is presumed to be because the trace component of the phosphor in the treatment liquid functions as a color developing aid in response to visible / ultraviolet light in the environment.

<Discharge inspection method for processing liquid for inkjet recording>
The discharge inspection method of the processing liquid for ink jet recording of the present invention is the above-described discharge inspection method using the processing liquid of the present invention. When the processing liquid is discharged from the discharge means, the processing liquid is normally discharged from the discharge means. Whether or not the discharge is performed is subjected to a discharge inspection by light emission of a phosphor contained in the processing liquid.

  The phosphor contained in the processing liquid serves as a marking agent that makes it easy to check the dischargeability (nozzle check) of the processing liquid in the discharge means. That is, the processing liquid is printed in an image like a nozzle check pattern, and it is inspected whether or not it is normally discharged by visually checking the light emission of the phosphor contained in the processing liquid.

As described above, the phosphor is (A) an organic fluorescent dye or the like that emits fluorescence or phosphorescence by irradiating with excitation energy of a specific wavelength (sensitive to the phosphor) such as ultraviolet rays and infrared rays. Or (B) Some materials emit phosphorescence in the dark after absorbing light (phosphorescent material). If the phosphor contained in the processing solution is (A), irradiate a specific excitation energy. , Confirm the discharge by visually confirming the generated fluorescence or phosphorescence. On the other hand, when the phosphor is (B), the light is preliminarily irradiated and stored, and then the emitted light is visually confirmed and discharged. In this case, it is preferable to check the discharge in a dark place for easy visual recognition.
Here, the “dark place” is 0 lux in a strict dark place. However, in this case, it may be an environment in which light emission can be visually recognized, and the environment in which the discharge inspection is performed is an environment with an illuminance of 30 lux or less. To do.

  The treatment liquid and detection principle of the present invention can also be applied to special printing applications such as forgery prevention and secret printing.

<Discharge means>
The processing liquid for ink jet recording and the ink set for ink jet recording of the present invention described above are ejected from ink ejecting means mounted on the ink jet printer. And in this invention, it is test | inspected whether the light color ink and / or the light color processing liquid are normally discharged from this discharge means. Examples of the ink discharge means include a nozzle, a slit, and a porous film.

<Recording medium>
Examples of the recording medium used in the method of the present invention include plain paper, coated paper, glossy paper, and other inkjet recording paper, but the recording medium does not contain a fluorescent material and does not emit light together with the printing unit. Since a recording medium is preferable, plastic films such as polyethylene terephthalate, cellophane, celluloid, polyethylene, and polypropylene are preferable. Common paper often contains a fluorescent material, but this can also be detected by comparing and observing the difference in light emission level from, for example, unused (no-printing) paper.

  The above-described ink jet recording ink ejection inspection method of the present invention can be applied not only to general users but also to product shipment inspection in factories.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example.

[Example 1]
First, the following composition components were mixed to prepare an inkjet recording treatment liquid (1).
(Composition of treatment liquid)
Fluorescent dye (CI Basic Yellow 40) 0.1 part by weight diethylene glycol 18 parts by weight glycerin 5 parts by weight magnesium nitrate 5 parts by weight urea 5 parts by weight polyoxyethylene 2-ethylhexyl ether (EO = 6) 0.5 parts by weight Polyoxyethylene stearyl ether (EO = 12) 0.1 part by mass ion-exchanged water remainder

  The prepared inkjet recording treatment liquid (1) is printed on a polyethylene terephthalate film using an 800 dpi, 256-nozzle prototype printhead and composed of an image that can identify each nozzle of 256 nozzles. When the ultraviolet ray (excitation energy) having a wavelength of 365 nm was irradiated, the printed nozzle check pattern emitted light, and the dischargeability of the treatment liquid could be easily confirmed.

[Example 2]
First, the following composition components were mixed and dispersed to prepare an inkjet recording treatment liquid (2).
(Composition of treatment liquid)
SrAl ₂ O ₄ : Eu, Dy 0.8 parts by mass Styrene-acrylic acid-sodium acrylate copolymer 1.5 parts by mass (St: AA = 33: 67 / weight molecular weight about 6100)
Diethylene glycol 18 parts by mass Glycerin 5 parts by mass Magnesium nitrate 5 parts by mass Urea 5 parts by mass Polyoxyethylene 2-ethylhexyl ether (EO = 6) 0.5 parts by mass Polyoxyethylene stearyl ether (EO = 12) 0.1 parts by mass Ion Exchange water balance

  The prepared inkjet recording treatment liquid (2) was printed on a polyethylene terephthalate film using an 800 dpi, 256-nozzle prototype printhead and composed of images capable of specifying each of the 256 nozzles. . When the printed nozzle check pattern was observed in a dark place, the printed part emitted light, and the dischargeability of the treatment liquid could be easily confirmed.

[Comparative Example 1]
First, a treatment liquid (4) for inkjet recording comprising the following composition components was prepared.
(Composition of treatment liquid)
Diethylene glycol 18 parts by mass Glycerin 5 parts by mass Magnesium nitrate 5 parts by mass Urea 5 parts by mass Polyoxyethylene 2-ethylhexyl ether (EO = 6) 0.5 parts by mass Polyoxyethylene stearyl ether (EO = 12) 0.1 parts by mass Ion Exchange water balance

  The prepared inkjet recording treatment liquid (4) was printed on a polyethylene terephthalate film using an 800 dpi, 256-nozzle prototype printhead and composed of images capable of identifying each of the 256 nozzles. However, even if it was irradiated with light or observed in a dark place, the printed nozzle check pattern was not visually recognized, and the nozzle discharge confirmation of the treatment liquid could not be confirmed.

[Example 3]
First, the following composition components were mixed and dispersed to prepare a black pigment ink.
(Composition of black pigment ink)
4 parts by mass of pigment dispersion (self-dispersed pigment; Cab-o-jet 300; manufactured by Cabot Corporation)
Styrene-acrylic acid-sodium acrylate copolymer 0.3 part by mass diethylene glycol 10 parts by mass glycerin 5 parts by mass 2-pyrrolidone 5 parts by mass urea 4 parts by mass acetylene glycol ethylene oxide adduct 0.2 parts by mass ion-exchanged water remainder

  Using the prepared black pigment ink and the treatment liquid (1) of Example 1 using a prototype printer having a plurality of prototype printheads of 800 dpi, 256 nozzles and a maintenance unit that individually accommodates a plurality of inks. A 100% solid image was printed on paper (C2 paper), and the image density (OD) was measured using X-Rite 404 (manufactured by X-Rite).

[Comparative Example 2]
A prototype printer having a black pigment ink prepared in Example 3 and the treatment liquid (4) of Comparative Example 1 having a plurality of prototype printheads of 800 dpi, 256 nozzles, and a maintenance unit that individually accommodates the plurality of inks. A 100% solid image was printed on plain paper (C2 paper), and the image density (OD) was measured using X-Rite 404 (manufactured by X-Rite).

  When the image densities of Example 3 and Comparative Example 2 were compared, it was 1.43 in Example 3, 1.38 in Comparative Example 2, and the treatment liquid (1) of Example 1 containing a phosphor. The image density increased when combined with. That is, it can be seen that Example 3 containing the treatment liquid of the present invention has a higher image density and improved color developability as compared with Comparative Example 2.

Claims (7)

Discharge inspection of an ink jet recording treatment liquid for inspecting whether or not the ink jet recording treatment liquid is normally discharged from the discharge means when discharging the ink jet recording treatment liquid containing at least the flocculant from the discharge means A method,
An ink jet recording processing liquid discharge inspection method, wherein the ink jet recording processing liquid further contains a phosphor, and discharge inspection is performed by light emission of the phosphor.   2. The method for injecting a processing liquid for ink jet recording according to claim 1, wherein the phosphor is an organic fluorescent material or an inorganic phosphorescent material.   The method for inspecting ejection of a treatment liquid for inkjet recording according to claim 1, wherein the flocculant is a pH adjuster or a polyvalent metal salt.   2. A method for inspecting a discharge of a processing liquid for ink jet recording according to claim 1, wherein the discharge inspection is performed by printing the processing liquid for ink jet recording on a recording medium and applying excitation energy to the recording medium. .   2. The method for inspecting ejection of a processing liquid for ink jet recording according to claim 1, wherein the recording medium on which the processing liquid for ink jet recording is printed in an image is observed in an environment of 30 lux or less.   A processing liquid for inkjet recording, comprising at least a flocculant and a phosphor.   An ink set for ink jet recording, comprising at least an ink for ink jet recording containing a color material and a treatment liquid for ink jet recording containing a flocculant and a phosphor.