JP2012236296A - Recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-demand recording method, by which a high-quality image free of feathering and a color bleed can be formed by using an aqueous inkjet recording ink on a recording medium that has a heat-sensitive recording material.SOLUTION: The recording method includes: a pretreatment step of applying a pretreatment liquid to the recording medium that has a heat-sensitive recording material formed by laminating a heat-sensitive recording layer and a protective layer, on one surface of a support; an inkjet recording step of forming the image on the recording medium by using the aqueous inkjet recording ink; and a heat-sensitive recording step of heating the heat-sensitive recording material. The pretreatment liquid contains a water-soluble aliphatic organic acid, a water-soluble organic monoamine compound, a wetting agent and water, whereas the inkjet recording ink contains an aqueous dispersion colorant, a water-soluble organic solvent, a surfactant, a penetrant, and the water.

Description

  The present invention relates to a recording method capable of forming a high-quality image using a water-based inkjet recording ink on a recording medium provided with a heat-sensitive recording material.

There is already known an image forming method in which a pretreatment liquid is applied or discharged onto the surface of a recording medium, and then pigment ink is discharged to agglomerate the pigment on the recording medium to improve image quality.
However, in the conventional image forming methods, the purpose of applying the pretreatment liquid is limited only to the purpose of imparting inkjet aptitude such as high image quality and feathering, color bleeding, and back-through suppression. On the other hand, in recent years, inkjet technology has been developed for industrial use, especially in fields that were primarily based on the use of thermal recording paper such as delivery slip paper, labels, and ticket paper. The suitability of both ink jets has been demanded. In these fields, improvements have been made in the past with the development of imparting inkjet suitability mainly to the protective layer on the printing surface based on thermal recording paper, but solvent-based inkjet mainly based on curing with actinic rays. Most of them are intended to impart printability to ink, and are not sufficient for water-based inkjet inks.

  In Patent Document 1, for the purpose of obtaining a heat-sensitive recording material having ink-jet suitability that does not cause hue failure or bleeding of an ink-jet image or image fading of a heat-sensitive recording image due to ink-jet ink, An intermediate layer that shields the solvent contained in the inkjet ink, an inkjet recording layer, a protective layer that prevents sticking during thermal recording, and an undercoat layer between the support and the thermal recording layer to increase the sensitivity of the thermal recording image A method of providing heat and inkjet combined suitability is disclosed. However, the basic configuration is different from the method of continuously performing inkjet printing after applying a pretreatment liquid to a recording medium equipped with a heat-sensitive recording material on demand as in the present invention to make it suitable for inkjet. Ink-jet suitability for ink-jet ink cannot be said to be sufficient, and problems such as feathering, color bleeding, and fixability cannot be solved. Furthermore, since a plurality of layers are laminated on the heat-sensitive recording layer, high energy is required at the time of heat-sensitive recording. As a result, the life of the thermal head is shortened and printing durability is poor, and the recording medium itself is expensive. There are many problems such as becoming.

  The present invention provides a high-quality image free of feathering and color bleed on demand using a water-based inkjet recording ink on a recording medium having a thermal recording material in which at least a thermal recording layer and a protective layer are sequentially laminated. An object is to provide a recording method that can be formed.

The above problems are solved by the following inventions 1) to 3).
1) A pretreatment step of applying a pretreatment liquid for inkjet recording to a recording medium provided with a heat sensitive recording material in which at least a heat sensitive recording layer and a protective layer are sequentially laminated on one surface of a support; and the pretreatment liquid A recording method comprising: an ink jet recording process for forming an image using a water-based ink jet recording ink; and a thermal recording process for heating a heat-sensitive recording material, wherein the pretreatment liquid is water-soluble It contains an aliphatic organic acid, a water-soluble organic monoamine compound, a wetting agent, and water, and the ink for inkjet recording contains a water-dispersible colorant, a water-soluble organic solvent, a surfactant, a penetrating agent, and water. A recording method characterized by the above.
2) The recording method according to 1), wherein the pretreatment liquid further contains an aliphatic organic acid salt compound or an inorganic metal salt compound.
3) The recording method according to 1) or 2), wherein the water-dispersible colorant contains any of the following (1) to (3).
(1) A pigment having at least one hydrophilic group on the surface and exhibiting water dispersibility in the absence of a dispersant (self-dispersing pigment)
(2) Pigment dispersion containing pigment, pigment dispersant and polymer dispersion stabilizer (3) Water dispersion of polymer fine particles containing pigment

According to the present invention, on a recording medium provided with a heat-sensitive recording material in which at least a heat-sensitive recording layer and a protective layer are sequentially laminated, water-based inkjet recording ink is used on demand, without feathering and color bleeding. A recording method capable of forming an image can be provided.
Also, when creating tickets, labels, delivery slips, etc., printing with thermal ink on inkjet recording paper can be done on demand. Therefore, the risk of image fading is reduced, and only the necessary amount can be printed, which can contribute to cost reduction.
Furthermore, since water-based inkjet recording ink is used, safety and environmental effects can be expected.

The figure which shows an example of the line inkjet apparatus suitable for implementing this invention. Schematic which shows the head arrangement | sequence of the head unit of the apparatus of FIG. FIG. 3 is a schematic enlarged view of the inkjet head of FIG. 2. The figure which shows an example of a serial inkjet apparatus. The figure which shows an example of a serial inkjet apparatus. The whole block explanatory drawing of the control part of an ink jet device. Schematic which shows an example of an ink cartridge. Schematic including the case (exterior) of the ink cartridge.

Hereinafter, the present invention will be described in detail.
In the recording method of the present invention, before applying a pretreatment liquid for ink jet recording (hereinafter also referred to as a pretreatment liquid) to a recording medium comprising a heat sensitive recording material in which at least a heat sensitive recording layer and a protective layer are sequentially laminated. A processing step, an ink jet recording step of forming an image using an ink for ink jet recording (hereinafter sometimes referred to as ink) on a recording medium provided with the pretreatment liquid, and a heat sensitive recording step of heating a heat sensitive recording material. Have
The pretreatment liquid contains a water-soluble aliphatic organic acid, a water-soluble organic monoamine compound, a wetting agent and water, and the ink contains a water-dispersible colorant, a water-soluble organic solvent, a surfactant, a penetrating agent. A water-based ink containing an agent and water is used.
By applying the pretreatment liquid to the entire recording medium and forming an image by an ink jet method immediately after the pretreatment, the pigment in the ink reacts with the organic acid in the pretreatment liquid and tends to stay on the surface of the recording medium. A quality image can be obtained.

<< Composition of pretreatment liquid >>
The pretreatment liquid used in the present invention contains a water-soluble aliphatic organic acid, a water-soluble organic monoamine compound, a wetting agent, and water. Furthermore, it is preferable to contain an aliphatic organic acid salt compound or an inorganic metal salt compound, and additives such as surfactants, penetrants, preservatives, and rust inhibitors may be added as necessary.

<Water-soluble aliphatic organic acid>
The water-soluble aliphatic organic acid is added for the purpose of improving the surface fixability by aggregation (acid precipitation) of the pigment.
The addition amount is preferably 1 to 40% by mass, more preferably 3 to 30% by mass, based on the entire pretreatment liquid. If the amount added is more than 40% by mass, the amount of water-soluble organic monoamine compound necessary for neutralization may not be added. If the amount added is less than 1% by mass, the effect of improving the image quality may be reduced. is there.
As the water-soluble aliphatic organic acid, a water-soluble aliphatic carboxyl group-containing organic acid or a water-soluble aliphatic sulfonic acid group-containing organic acid is preferably used. Here, aliphatic means that it contains a linear or branched saturated or unsaturated hydrocarbon group. The number of carbon atoms of the water-soluble aliphatic organic acid is not particularly limited, but is preferably 6 or less per molecule from the viewpoint of solubility in a solvent.
The number of acid groups in the water-soluble aliphatic organic acid is preferably 3 or less, more preferably 2 or less, and still more preferably 1 per molecule from the viewpoint of image density.
As the water-soluble aliphatic organic acid, water-soluble aliphatic carboxyl group-containing organic acids represented by the following formulas (I) to (III) are preferably used.

［式中、Ｒ^１は水素原子、又はカルボキシル基により置換されたメチル基を示し、Ｒ^２はメチル基、カルボキシル基により置換されたメチル基、又は水酸基及びカルボキシル基により置換されたメチル基を示す。］

［式中、ｎは０〜４の整数を示す。］

［式中、ｎは０〜４の整数を示す。］

[Wherein, R ¹ represents a hydrogen atom or a methyl group substituted by a carboxyl group, and R ² represents a methyl group, a methyl group substituted by a carboxyl group, or a methyl group substituted by a hydroxyl group and a carboxyl group. . ]

[Wherein n represents an integer of 0 to 4. ]

[Wherein n represents an integer of 0 to 4. ]

Examples of the compound represented by formula (I) include lactic acid (pKa: 3.83), malic acid (pKa: 3.4), citric acid (pKa: 3.13), and tartaric acid (pKa: 2.93). ) And the like. Examples of the compound represented by the formula (II) include oxalic acid (pKa: 1.04), malonic acid (pKa: 2.05), succinic acid (pKa: 4.21), and adipic acid (pKa: 4.4). 42). Examples of the compound represented by the formula (III) include acetic acid (pKa: 4.76), propionic acid (pKa: 4.87), butyric acid (pKa: 4.82), and valeric acid (pKa: 4.82). ) And the like.
Examples of water-soluble aliphatic carboxyl group-containing organic acids other than the formulas (I) to (III) include gluconic acid (pKa: 2.2), pyruvic acid (pKa: 2.49), fumaric acid (pKa: 3. 02) and the like. Examples of the water-soluble aliphatic sulfonic acid group-containing organic acid include taurine.

<Water-soluble organic monoamine compound>
The water-soluble organic monoamine compound is added for the purpose of forming a neutralized salt with a water-soluble aliphatic organic acid. The addition amount is preferably 1.0 to 1.5 mol with respect to 1 mol of acid groups contained in the water-soluble aliphatic organic acid. More preferably, it is 1.0-1.2 mol. If the amount added is less than 1.0 mol, white streaks may occur due to the narrowing of dots in the image-formed product. If the amount added exceeds 1.5 mol, the free water-soluble organic monoamine compound penetrates into the ink. May be reduced to lower the image density.
The water-soluble organic monoamine compound may be any of primary, secondary, tertiary, quaternary amines and salts thereof. The quaternary amine means a compound in which four alkyl groups are substituted on the nitrogen atom.
As the water-soluble organic monoamine compound, a compound represented by the following formula (VI) or (V) is preferably used.

［式中、Ｒ^３、Ｒ^４、Ｒ^５は水素原子、炭素数１〜４のアルコキシ基、炭素数１〜８のアルキル基、ヒドロキシエチル基、又はヒドロキシプロピル基を示す。但し、全て水素原子である場合を除く。］

［式中、Ｒ^６はヒドロキシメチル基を示し、Ｒ^７はメチル基、エチル基、又はヒドロキシメチル基を示し、Ｒ^８は水素原子、炭素数１〜４のアルキル基、又はヒドロキシメチル基を示す。］

[In formula, R < ³ >, R < ⁴ >, R < ⁵ > shows a hydrogen atom, a C1-C4 alkoxy group, a C1-C8 alkyl group, a hydroxyethyl group, or a hydroxypropyl group. However, the case where all are hydrogen atoms is excluded. ]

[Wherein R ⁶ represents a hydroxymethyl group, R ⁷ represents a methyl group, an ethyl group, or a hydroxymethyl group, and R ⁸ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a hydroxymethyl group. . ]

Examples of the compound represented by the formula (IV) include dimethylamine, ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, isopropylamine, diisopropylamine, n-butylamine, s-butylamine, t-butylamine, di- n-butylamine, tributylamine, pentylamine, dipentylamine, tripentylamine, 2-ethylhexylamine, di-2-ethylhexylamine, di-n-octylamine, tri-n-octylamine, 1-amino-2-propanol 3-amino-1-propanol, N-methylethanolamine, N, N-diethylethanolamine, N, N-dimethylethanolamine, N-methyldiethanolamine, diethanolamine, triethanolamine, Isopropanolamine, N- butyl diethanolamine, N, N- dibutyl ethanolamine, and the like.
Examples of the compound represented by the formula (V) include 2-amino-2-ethyl-1,3-propanediol, 2-amino-2- (hydroxymethyl) -1,3-propanediol, and 2-amino. -2-methyl-1,3-propanediol, 2-amino-2-methyl-1-propanol and the like.
Examples of the water-soluble organic monoamine compound other than the formula (IV) or (V) include allylamine, diallylamine, 3-ethoxypropylamine, 2- (2-aminoethoxy) ethanol, 3-methoxypropylamine, choline and the like. Can be mentioned.

<Wetting agent>
A wetting agent is added for the purpose of improving the moisture retention of the pretreatment liquid.
Although the addition amount is not particularly limited, it is usually 10 to 80% by mass, preferably 15 to 60% by mass, based on the whole pretreatment liquid. If it is more than 80% by weight, depending on the type of wetting agent, there is a possibility that drying will be poor on the recording medium after the pretreatment. There is a possibility that the composition of the treatment liquid may change significantly.
As the wetting agent, a water-soluble organic solvent is mainly used, but a solid material may be used.
Specific examples include 1,2,3-butanetriol (bp175 ° C./33 hPa, 38 mass%), 1,2,4-butanetriol (bp 190-191 ° C./24 hPa, 41 mass%), glycerin (bp 290 ° C., 49 mass%), diglycerin (bp 270 ° C./20 hPa, 38 mass%), triethylene glycol (bp 285 ° C., 39 mass%), tetraethylene glycol (bp 324 to 330 ° C., 37 mass%), diethylene glycol (bp 245 ° C., 43 Mass%), 1,3-butanediol (bp 203 to 204 ° C., 35 mass%) and the like. Of these, glycerin and 1,3-butanediol are particularly preferably used for reasons such as lowering the viscosity when water is contained, and keeping the pigment dispersion stable without aggregation. It is preferable to use glycerin and 1,3-butanediol in an amount of 50% by mass or more of the whole wetting agent because it is excellent in securing ejection stability and preventing waste ink sticking in a maintenance device of an ink ejection device.

In place of or in addition to a part of the wetting agent as necessary, polyhydric alcohols, polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, Materials such as amines, sulfur-containing compounds, propylene carbonate, and ethylene carbonate can be used.
Examples of the polyhydric alcohols include dipropylene glycol (bp 232 ° C), 1,5-pentanediol (bp 242 ° C), 3-methyl-1,3-butanediol (bp 203 ° C), and propylene glycol (bp 187 ° C). 2-methyl-2,4-pentanediol (bp 197 ° C.), ethylene glycol (bp 196 to 198 ° C.), tripropylene glycol (bp 267 ° C.), hexylene glycol (bp 197 ° C.), polyethylene glycol (viscous liquid to solid) , Polypropylene glycol (bp 187 ° C.), 1,6-hexanediol (bp 253 to 260 ° C.), 1,2,6-hexane triol (bp 178 ° C.), trimethylol ethane (solid, mp 199 to 201 ° C.), trimethylol propane ( Solid, mp61 ° C) And the like.

Examples of the polyhydric alcohol alkyl ethers include ethylene glycol monoethyl ether (bp 135 ° C.), ethylene glycol monobutyl ether (bp 171 ° C.), diethylene glycol monomethyl ether (bp 194 ° C.), diethylene glycol monoethyl ether (bp 197 ° C.), and diethylene glycol monoethyl ether. Examples include butyl ether (bp 231 ° C.), ethylene glycol mono-2-ethylhexyl ether (bp 229 ° C.), propylene glycol monoethyl ether (bp 132 ° C.), and the like.
Examples of the polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether (bp 237 ° C.) and ethylene glycol monobenzyl ether.
Examples of the nitrogen-containing heterocyclic compound include 2-pyrrolidone (bp 250 ° C., mp 25.5 ° C., 47 to 48% by mass), N-methyl-2-pyrrolidone (bp 202 ° C.), 1,3-dimethyl-2- Examples include imidazolidinone (bp 226 ° C.), ε-caprolactam (bp 270 ° C.), γ-butyrolactone (bp 204 to 205 ° C.), and the like.

Examples of the amides include formamide (bp 210 ° C.), N-methylformamide (bp 199 to 201 ° C.), N, N-dimethylformamide (bp 153 ° C.), N, N-diethylformamide (bp 176 to 177 ° C.) and the like. Can be mentioned.
Examples of the amines include monoethanolamine (bp 170 ° C), diethanolamine (bp268 ° C), triethanolamine (bp360 ° C), N, N-dimethylmonoethanolamine (bp139 ° C), N-methyldiethanolamine (bp243 ° C). ), N-methylethanolamine (bp 159 ° C.), N-phenylethanolamine (bp 282 to 287 ° C.), 3-aminopropyldiethylamine (bp 169 ° C.) and the like.
Examples of the sulfur-containing compounds include dimethyl sulfoxide (bp 139 ° C.), sulfolane (bp 285 ° C.), thiodiglycol (bp 282 ° C.), and the like.

In addition to the above materials, saccharides may be added as a solid wetting agent. Examples of saccharides include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides), polysaccharides, and the like. Specific examples include glucose, mannose, fructose, ribose, xylose, arabinose, galactose, maltose, cellobiose, lactose, sucrose, trehalose, maltotriose, and the like. Here, the polysaccharide means a saccharide in a broad sense, and is used to include a substance that exists widely in nature such as α-cyclodextrin and cellulose. Derivatives of these saccharides include reducing sugars (for example, sugar alcohol [general _{formula: HOCH 2 (CHOH) nCH 2} OH ( where, n is represented by an integer of 2-5). ], Oxidized sugars (for example, aldonic acid, uronic acid, etc.), amino acids, thioic acids, etc. Among these, sugar alcohols are preferred, and specific examples include maltitol, sorbit and the like.

<Aliphatic organic acid salt compound, inorganic metal salt compound>
Aliphatic organic acid salt compounds and inorganic metal salt compounds are added for the purpose of promoting the salting-out effect of the pigment.
The addition amount is preferably 0.1 to 30% by mass, more preferably 1 to 20% by mass, based on the entire pretreatment liquid. When the amount is more than 30% by mass, the aliphatic organic acid salt compound or the inorganic metal salt compound may be precipitated without being sufficiently dissolved, and when the amount is less than 0.1% by mass, the effect of improving the image density is reduced. There is.
Examples of the aliphatic organic acid salt compound include sodium L-aspartate, magnesium L-aspartate, calcium L-ascorbate, sodium L-ascorbate, sodium oxalate, disodium oxalate, and diammonium oxalate. , Disodium citrate, trisodium citrate, potassium citrate, tripotassium citrate, diammonium citrate, triammonium citrate, calcium citrate, aluminum citrate, sodium lactate, potassium lactate, ammonium lactate, calcium lactate, Examples include magnesium lactate, zinc lactate, aluminum lactate, potassium tartrate, DL-sodium tartrate, sodium potassium tartrate, calcium tartrate and the like.
Examples of the inorganic metal salt compound include lithium sulfate, sodium sulfate, potassium sulfate, sodium hydrogen sulfate, potassium hydrogen sulfate, sodium nitrate, potassium nitrate, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium chloride, chloride. Alkali metal salts such as potassium, magnesium sulfate, aluminum sulfate, manganese sulfate, nickel sulfate, iron (II) sulfate, copper (II) sulfate, zinc sulfate, strontium nitrate, manganese (II) nitrate, iron (II) nitrate, nitric acid Iron (III), cobalt nitrate, nickel nitrate (II), copper nitrate (II), lead nitrate (II), calcium chloride, magnesium chloride, strontium chloride, barium chloride, nickel (II) chloride, tin (II) chloride, etc. Is mentioned.

<Surfactant>
The surfactant is added for the purpose of modifying the wettability of the surface of the recording medium and improving the image density, saturation and white spot of the image formed product.
The addition amount is preferably 0.001 to 5 mass%, more preferably 0.05 to 1 mass%, based on the entire pretreatment liquid. If the addition amount is less than 0.001% by mass, the effect of adding the surfactant may be reduced. If the addition amount is more than 5% by mass, there may be no difference in effect even if the addition amount is increased.
Moreover, it is preferable to adjust the static surface tension of the pretreatment liquid to 30 mN / m by adding a surfactant.
As the surfactant, nonionic surfactants, anionic surfactants, betaine surfactants, silicone surfactants, and fluorosurfactants are preferably used. Particularly, silicone surfactants and fluorosurfactants are used. Surfactants are preferred. These surfactants may be used alone or in combination of two or more.

［式中、ｍは０〜１０の整数を示す。ｎは１〜４０の整数を示す。］ As the fluorine-based surfactant, those having 2 to 16 carbon atoms substituted with fluorine are preferable, and those having 4 to 16 carbon atoms substituted with fluorine are more preferable. If the number of carbon atoms substituted with fluorine is less than 2, the effect of fluorine may not be obtained, and if it exceeds 16, problems such as storage stability may occur.
Examples of fluorosurfactants include perfluoroalkyl sulfonic acid compounds, perfluoroalkyl carboxylic acid compounds, perfluoroalkyl phosphate compounds, perfluoroalkyl ethylene oxide adducts, and perfluoroalkyl ether groups in the side chain. And polyoxyalkylene ether polymer compounds.
Among these, a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain is preferable because of its low foaming property, and a fluorine-based surfactant represented by the following formula (1) is particularly preferable.

[Wherein, m represents an integer of 0 to 10. n shows the integer of 1-40. ]

Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid, perfluoroalkyl sulfonate, and the like.
Examples of the perfluoroalkyl carboxylic acid compound include perfluoroalkyl carboxylic acid and perfluoroalkyl carboxylate.
Examples of the perfluoroalkyl phosphate compound include perfluoroalkyl phosphate esters, perfluoroalkyl phosphate salts, and the like.
The polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain includes a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain, and a polyoxyalkylene ether having a perfluoroalkyl ether group in the side chain. Examples thereof include a sulfate salt of a polymer and a salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain.
As counter ions of salts in these fluorosurfactants, Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , NH (CH ₂ CH ₂ OH) ₃ etc. are mentioned.

  As said fluorosurfactant, what was synthesize | combined suitably may be used and a commercial item may be used. Examples of the commercially available products include Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, and S-145 (all manufactured by Asahi Glass Co., Ltd.); FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M); Megafac F-470, F-1405 F-474 (all manufactured by Dainippon Ink & Chemicals, Inc.); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR (all DuPont) FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (all manufactured by Neos), Polyfox F-136A, PF-156A, PF-151N, PF-154, PF-159 (Omnova Co., Ltd.) and the like can be mentioned. Among these, good print quality, particularly color development and leveling on paper are remarkably improved. From the point of view, DuPont FS-300, Neos FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW and Omninova Polyfox PF-151N preferable.

ただし、式中のＲｆは下記〔化８〕で示されるフッ素含有疎水基の混合物を表わす。Ａは、−ＳＯ_３Ｘ、−ＣＯＯＸ、又は−ＰＯ_３Ｘ〔Ｘは、Ｈ、Ｌｉ、Ｎａ、Ｋ、ＮＨ_４、ＮＨ_３ＣＨ_２ＣＨ_２ＯＨ、ＮＨ_２（ＣＨ_２ＣＨ_２ＯＨ）_２、又はＮＨ（ＣＨ_２ＣＨ_２ＯＨ）_３など〕を表わす。

In addition to the above, those represented by the following formulas (2) to (10) are also preferably used.
(A) Anionic fluorosurfactant

However, Rf in the formula represents a mixture of fluorine-containing hydrophobic groups represented by the following [Chemical Formula 8]. A _is, -SO 3 _{X, -COOX,} or -PO ₃ X [X _{represents, H, Li, Na, K} , NH 4, NH 3 CH 2 CH 2 OH, NH 2 (CH 2 CH 2 OH) 2, Or NH (CH ₂ CH ₂ OH) ₃ or the like].

ただし、式中のＲｆ′は下記〔化１０〕で表わされるフッ素含有基を表わす。Ｘは、前記（２）式のＸと同じ意味を表わす。ｎは１又は２の整数、ｍは２−ｎを表わす。

ただし、式中のｎは３〜１０の整数を表わす。

However, Rf 'in the formula represents a fluorine-containing group represented by the following [Chemical Formula 10]. X represents the same meaning as X in the formula (2). n represents an integer of 1 or 2, and m represents 2-n.

However, n in a formula represents the integer of 3-10.

ただし、式中のＲｆ′及びＸは、前記（３）式のＲｆ′及びＸと同じ意味を表わす。

However, Rf ′ and X in the formula represent the same meaning as Rf ′ and X in the formula (3).

ただし、式中のＲｆ′及びＸは、前記（３）式のＲｆ′及びＸと同じ意味を表わす。

However, Rf ′ and X in the formula represent the same meaning as Rf ′ and X in the formula (3).

ただし、式中のＲｆは、前記（２）式のＲｆと同じ意味を表わす。ｎは５〜２０の整数を表わす。 (B) Nonionic fluorosurfactant

However, Rf in the formula represents the same meaning as Rf in the formula (2). n represents an integer of 5 to 20.

ただし、式中、Ｒｆ′は、前記（３）式のＲｆ′と同じ意味を表わす。ｎは１〜４０の整数を表わす。

However, in the formula, Rf ′ represents the same meaning as Rf ′ in the formula (3). n represents an integer of 1 to 40.

ただし、式中、Ｒｆは、前記（２）式のＲｆと同じ意味を表わす。 (C) Amphoteric fluorosurfactant

However, in the formula, Rf represents the same meaning as Rf in the formula (2).

ただし、式中、Ｒｆ″は、下記〔化１７〕で表わされるフッ素含有基を表わす。ｎは０〜１０の整数を表わす。Ｘは、前記（２）式のＸと同じ意味を表わす。

ただし、前記構造式中、ｎは１〜４の整数を表わす。 (D) Oligomer type fluorosurfactant

In the formula, Rf ″ represents a fluorine-containing group represented by the following [Chemical Formula 17]. N represents an integer of 0 to 10. X represents the same meaning as X in the formula (2).

However, in said structural formula, n represents the integer of 1-4.

ただし、式中のＲｆ″は、前記（９）式のＲｆ″と同じ意味を表わす。ｌは０〜１０の整数、ｍは０〜１０の整数、ｎは０〜１０の整数をそれぞれ表わす。

However, Rf ″ in the formula represents the same meaning as Rf ″ in the formula (9). l represents an integer of 0 to 10, m represents an integer of 0 to 10, and n represents an integer of 0 to 10, respectively.

The silicone surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, side chain modified polydimethylsiloxane, both terminal modified polydimethylsiloxane, one terminal modified polydimethylsiloxane, side chain Examples thereof include polydimethylsiloxane modified at both ends, and a polyether-modified silicone surfactant having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group is particularly preferable because it exhibits good properties as an aqueous surfactant. .
As such a surfactant, an appropriately synthesized product or a commercially available product may be used. Such commercially available products can be easily obtained from, for example, Big Chemie Co., Ltd., Shin-Etsu Chemical Co., Ltd., Toray Dow Corning Silicone Co., Ltd., Nippon Emulsion Co., Ltd., Kyoeisha Chemical Co., Ltd.

ただし、式中の、ｍ、ｎ、ａ、及びｂは整数を表わす。Ｒ及びＲ′はアルキル基、アルキレン基を表わす。
ポリエーテル変性シリコーン系界面活性剤の市販品としては、例えば、ＫＦ−６１８、ＫＦ−６４２、ＫＦ−６４３（信越化学工業社）、ＥＭＡＬＥＸ−ＳＳ−５６０２、ＳＳ−１９０６ＥＸ（日本エマルジョン社）、ＦＺ−２１０５、ＦＺ−２１１８、ＦＺ−２１５４、ＦＺ−２１６１、ＦＺ−２１６２、ＦＺ−２１６３、ＦＺ−２１６４（東レ・ダウコーニング・シリコーン社）、ＢＹＫ−３３、ＢＹＫ−３８７（ビックケミー社）などが挙げられる。 The polyether-modified silicone surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. And the like, and the like.

However, m, n, a, and b in a formula represent an integer. R and R ′ represent an alkyl group or an alkylene group.
Examples of commercially available polyether-modified silicone surfactants include KF-618, KF-642, KF-643 (Shin-Etsu Chemical Co., Ltd.), EMALEX-SS-5602, SS-1906EX (Nippon Emulsion Co., Ltd.), FZ. -2105, FZ-2118, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ-2164 (Toray Dow Corning Silicone), BYK-33, BYK-387 (Bic Chemie) It is done.

Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, laurate, polyoxyethylene alkyl ether sulfate salt, and the like.
Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxypropylene polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl ether, and polyoxyethylene alkyl. And amines and polyoxyethylene alkylamides.

<Penetration agent>
The penetrating agent is added for the purpose of promoting penetration of the water-soluble organic solvent into the recording medium.
As the penetrant, it is preferable to contain at least one non-wetting agent polyol compound or glycol ether compound having 8 to 11 carbon atoms. Among these, those having a solubility of 0.2 to 5.0% by mass in water at 25 ° C. are preferable, and in particular, 2-ethyl-1,3-hexanediol [solubility: 4.2% (25 ° C.)] 2,2,4-trimethyl-1,3-pentanediol [solubility: 2.0% (25 ° C.)] is preferable.
Other non-wetting agent polyol compounds include aliphatic diols such as 2-ethyl-2-methyl-1,3-propanediol, 3,3-dimethyl-1,2-butanediol, and 2,2-diethyl- 1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-dimethyl-2,4-pentanediol, 2,5-dimethyl-2,5-hexanediol, 5- Hexene-1,2-diol, and the like.

Other penetrants that can be used in combination are not particularly limited as long as they can be dissolved in the ink and adjusted to the desired physical properties, and can be appropriately selected according to the purpose. For example, diethylene glycol monophenyl ether, ethylene Glycol monophenyl ether, ethylene glycol monoallyl ether, diethylene glycol monophenyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, alkyl and aryl ethers of polyhydric alcohols such as tetraethylene glycol chlorophenyl ether, lower alcohols such as ethanol, etc. Is mentioned.
The addition amount of the penetrant in the pretreatment liquid is preferably 0.1 to 5.0% by mass. If the amount added is less than 0.1% by mass, the effect of penetrating the ink may be lost. The effect may be saturated.

≪Pretreatment method in pretreatment process≫
In the pretreatment process, a coating method for uniformly coating the pretreatment liquid on the surface of the recording medium may be used, and there is no particular limitation. Examples of such coating methods include blade coating, gravure coating, gravure offset coating, bar coating, roll coating, knife coating, air knife coating, comma coating, U comma coating, AKKU. Examples thereof include a coating method, a smoothing coating method, a micro gravure coating method, a reverse roll coating method, a 4 to 5 roll coating method, a dip coating method, a curtain coating method, a slide coating method, and a die coating method.
The pretreatment process may be performed on a recording medium whose surface is sufficiently dried or may be performed on a recording medium being dried. In addition, a drying process can be provided for the pretreated recording medium as necessary. In this case, the recording medium can be dried with a roll heater, a drum heater or hot air.
The wet adhesion amount of the pretreatment liquid to the recording medium is preferably in the range of 0.1 to 30.0 g / m ² , more preferably 0.2 to 10.0 g / m ² . If the adhesion amount is less than 0.1 g / m ² , the effect of improving the image quality (image density, saturation, color bleed, character bleeding and white spot) may be hardly observed, and if it exceeds 30.0 g / m ^2. The texture of plain paper may be damaged or curl may occur.

≪Ink composition≫
The ink used in the present invention contains a water-dispersible colorant, a water-soluble organic solvent, a surfactant, a penetrating agent, and water. Furthermore, it is preferable to contain a water-dispersible resin, a pH adjuster, an antiseptic / antifungal agent, and a rust preventive agent. These additives may be added.

<Water dispersible colorant>
As the water dispersible colorant, a pigment is mainly used from the viewpoint of weather resistance, but a dye may be contained within a range in which the weather resistance is not deteriorated for the purpose of adjusting the color tone.
The content of the colorant is preferably 2 to 15% by mass, more preferably 3 to 12% by mass based on the total ink in terms of solid content. If the content is less than 2% by mass, the color developability and the image density of the ink may be lowered, and if it exceeds 15% by mass, the ink may be thickened and the dischargeability may be deteriorated. Absent.
There is no restriction | limiting in particular as a pigment, According to the objective, it can select suitably, For example, the inorganic pigment and organic pigment for black or color are mentioned. These may be used individually by 1 type and may use 2 or more types together.

Inorganic pigments include titanium oxide and iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, and chrome yellow, as well as carbon produced by known methods such as the contact method, furnace method, and thermal method. Black can be used.
Organic pigments include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments), polycyclic pigments (eg, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazines). Pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinofullerone pigments, etc.), dye chelates (for example, basic dye type chelates, acidic dye type chelates), nitro pigments, nitroso pigments, aniline black, and the like can be used. Of these pigments, those having a good affinity for water are particularly preferable.

Of the above, specific examples of pigments preferably used include black for carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, copper, iron (CI pigment black 11), metals such as titanium oxide, and organic pigments such as aniline black (CI pigment black 1).
For color, C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104 , 408, 109, 110, 117, 120, 128, 138, 150, 151, 153, 183, C.I. I. Pigment orange 5, 13, 16, 17, 36, 43, 51, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48: 2, 48: 2 [Permanent Red 2B (Ca)], 48: 3, 48: 4, 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81, 83, 88, 101 (Bengara), 104, 105, 106, 108 ( Cadmium red), 112, 114, 122 (quinacridone magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 185, 190, 193, 209, 219, C.I. I. Pigment violet 1 (rhodamine lake), 3, 5: 1, 16, 19, 23, 38, C.I. I. Pigment Blue 1, 2, 15, 15: 1, 15: 2, 15: 3 (phthalocyanine blue), 16, 17: 1, 56, 60, 63, C.I. I. Pigment green 1, 4, 7, 8, 10, 17, 18, 36, and the like.

The following first and second forms are particularly preferable when the colorant is a pigment.
(1) First form: The colorant contains an aqueous dispersion of polymer fine particles containing a pigment that is insoluble or hardly soluble in water.
(2) Second form: The colorant has at least one hydrophilic group on the surface and exhibits water dispersibility in the absence of a dispersant (hereinafter sometimes referred to as “self-dispersible pigment”). ).
As the water-dispersible colorant of the first form, it is preferable to use a polymer emulsion in which a pigment is contained in polymer fine particles in addition to the pigment. The polymer emulsion in which the pigment is contained in the polymer fine particles is one in which the pigment is encapsulated in the polymer fine particles, or the pigment is adsorbed on the surface of the polymer fine particles. In this case, it is not necessary for all the pigments to be encapsulated or adsorbed, and the pigments may be dispersed in the emulsion as long as the effects of the present invention are not impaired. Examples of the polymer forming the polymer emulsion (polymer in the polymer fine particles) include vinyl polymers, polyester polymers, polyurethane polymers, and the like. Particularly preferably used polymers are vinyl polymers and polyester polymers. Polymers disclosed in 2000-53897 and JP 2001-139849 can be used.

The self-dispersing pigment of the second form is a surface modified so that at least one hydrophilic group is bonded to the surface of the pigment directly or via another atomic group. For the surface modification, a specific functional group (functional group such as a sulfonic acid group or a carboxyl group) is chemically bonded to the surface of the pigment, or at least one of hypohalous acid and a salt thereof is used. A method such as a wet oxidation treatment using a nitrile is used. Among these, a form in which a carboxyl group is bonded to the surface of the pigment and dispersed in water is particularly preferable. Thus, when the pigment is surface-modified and the carboxyl group is bonded, the dispersion stability is improved, high-quality printing quality is obtained, and the water resistance of the recording medium after printing is improved.
In addition, the ink containing the self-dispersing pigment is excellent in redispersibility after drying, so printing is paused for a long period of time, and clogging does not occur even when ink moisture near the ink jet head nozzle evaporates, and simple cleaning is possible. Good printing can be easily performed by operation.
The volume average particle diameter (D50) of the self-dispersing pigment is preferably 0.01 to 0.16 μm in the ink.
Moreover, in the case of the 2nd form, it is preferable that the water dispersible resin mentioned later is included.

As the self-dispersing pigment, those having ionicity are preferable, and those having an anionic charge are preferable.
Examples of the anionic hydrophilic groups for anionic, for _{example, -COOM, -SO 3 M, -PO} 3 HM, -PO 3 M 2, -SO 2 NH 2, -SO 2 NHCOR ( although, M is And R represents an alkyl group having 1 to 12 carbon atoms, a phenyl group which may have a substituent, or a naphthyl group which may have a substituent. Can be mentioned. Examples of the alkali metal “M” include lithium, sodium, and potassium. Examples of organic ammonium include mono to trimethyl ammonium, mono to triethyl ammonium, and mono to trimethanol ammonium.
When the pigment is carbon black, the hydrophilic group may be bonded to the surface of carbon black via another atomic group. Examples of other atomic groups include an alkyl group having 1 to 12 carbon atoms, a phenyl group which may have a substituent, or a naphthyl group which may have a substituent. As specific _examples, -C ₂ H 4 COOM (provided that, M represents an alkali metal or quaternary ammonium), - PhSO ₃ M (however, .M Ph is the phenyl group, an alkali metal, Or represents quaternary ammonium).
Among these, those in which —COOM and —SO ₃ M are bonded to the surface of the color pigment are preferable. As a method of obtaining such an anionically charged color pigment, as a method of introducing -COONa into the color pigment surface, for example, a method of oxidizing a color pigment with sodium hypochlorite, a method by sulfonation, The method of making a diazonium salt react is mentioned.

<Water-soluble organic solvent>
A water-soluble organic solvent is mainly added as a wetting agent.
The mass ratio of the water-dispersible colorant and the water-soluble organic solvent in the ink affects the ink ejection stability from the head. For example, when the solid content of the water-dispersible colorant is high but the blending amount of the water-soluble organic solvent is small, water evaporation near the ink meniscus of the nozzle may progress and cause ejection failure. Therefore, the addition amount of the water-soluble organic solvent in the ink is preferably 20 to 50% by mass, and more preferably 20 to 45% by mass. When the addition amount is less than 20% by mass, there is a possibility that the ejection stability is lowered or the waste ink is fixed by the maintenance device of the ink jet recording apparatus. On the other hand, if it exceeds 50% by mass, the dryness on the paper surface is inferior and the character quality on plain paper may be lowered.
As the water-soluble organic solvent, the same water-soluble organic solvent as in the case of the pretreatment liquid is preferably used.

<Surfactant>
The surfactant is added for the purpose of lowering the surface tension of the ink, improving the permeability and leveling properties.
The addition amount is preferably 0.01 to 3.0% by mass of the whole ink, and more preferably 0.5 to 2.0% by mass. If the addition amount is less than 0.01% by mass, the effect of adding the surfactant may be lost. And strikethrough may occur.
As the surfactant, at least one selected from an anionic surfactant, a nonionic surfactant, a silicone surfactant, and a fluorine surfactant is preferable. Among these, silicone surfactants and fluorine surfactants are particularly preferable. These surfactants can be used individually by 1 type or in mixture of 2 or more types.
Specific examples of the surfactant include those similar to the case of the pretreatment liquid.

<Penetration agent>
The penetrant is added for the purpose of promoting penetration of the water-soluble organic solvent in the ink into the recording medium and improving the drying property of the ink.
The addition amount is preferably 0.1 to 4.0% by mass of the total ink. If the addition amount is less than 0.1% by mass, quick drying may not be obtained and a blurred image may be obtained. If the addition amount exceeds 4.0% by mass, the dispersion stability of the colorant is impaired and the nozzle is clogged. In some cases, it becomes easier, and the permeability to the recording medium becomes higher than necessary, resulting in a decrease in image density and through-through.
Examples of the penetrant include the same as those in the case of the pretreatment liquid.

<Water dispersible resin>
The water-dispersible resin is preferably added to improve image quality, improve image weather resistance, and fixability.
The addition amount is preferably 1 to 15% by mass, more preferably 2 to 7% by mass based on the total ink in terms of solid content.
Examples of the water-dispersible resin include condensation-type synthetic resins, addition-type synthetic resins, and natural polymer compounds.
Examples of the condensed synthetic resin include polyester resin, polyurethane resin, polyepoxy resin, polyamide resin, polyether resin, poly (meth) acrylic resin, acrylic-silicone resin, and fluorine-based resin.
Examples of the addition type synthetic resin include polyolefin resins, polystyrene resins, polyvinyl alcohol resins, polyvinyl ester resins, polyacrylic acid resins, unsaturated carboxylic acid resins, and the like.
Examples of the natural polymer compound include celluloses, rosins, and natural rubber.
Among these, polyurethane resin fine particles, acrylic-silicone resin fine particles, and fluorine-based resin fine particles are particularly preferable. Moreover, it is not a problem to use two or more kinds of the water-dispersible resins in combination.

<Other additives>
Other additives are not particularly limited and may be appropriately selected as necessary. An absorber, a light stabilizer, etc. are mentioned.
The pH adjuster is not particularly limited as long as it can adjust the pH to 7 to 11 without adversely affecting the prepared ink, and can be appropriately selected according to the purpose. When the pH is out of the above range, the amount of the ink jet head and the ink supply unit that melts out increases, and problems such as ink deterioration, leakage, and ejection failure may occur.
Examples of pH adjusting agents include alcohol amines, alkali metal hydroxides, ammonium hydroxides, phosphonium hydroxides, alkali metal carbonates, and the like.
Examples of the alcohol amines include diethanolamine, triethanolamine, 2-amino-2-ethyl-1,3-propanediol, and the like.
Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, and potassium hydroxide.
Examples of the ammonium hydroxide include ammonium hydroxide and quaternary ammonium hydroxide.
Examples of the phosphonium hydroxide include quaternary phosphonium hydroxide.
Examples of the alkali metal carbonate include lithium carbonate, sodium carbonate, and potassium carbonate.

Examples of antiseptic and antifungal agents include sodium dehydroacetate, sodium sorbate, 2-pyridinethiol-1-oxide sodium, sodium benzoate, sodium pentachlorophenol, and the like.
Examples of the chelating reagent include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uramil diacetate, and the like.
Examples of the rust inhibitor include acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.
Examples of the antioxidant include phenolic antioxidants (including hindered phenolic antioxidants), amine-based antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, and the like.
Examples of the UV absorber include benzophenone UV absorbers, benzotriazole UV absorbers, salicylate UV absorbers, cyanoacrylate UV absorbers, nickel complex salt UV absorbers, and the like.

<< Ink application method in inkjet recording process >>
The ink jet recording step is a step of forming an image by applying a stimulus (energy) to ink and causing the ink to fly on a recording medium coated with a pretreatment liquid.
As a method of forming an image on a recording medium by flying ink, various known ink jet recording methods can be applied. For example, there is an ink jet recording method of scanning a head or a lined head. There is an ink jet recording method in which an image is recorded on a sheet recording medium.
There is no particular limitation on the driving method of the recording head that is the ink flying means, and a piezoelectric element actuator using PZT or the like, a method of applying thermal energy, an on-demand type head using an actuator using electrostatic force, etc. is used. Alternatively, a continuous ejection type charge control type head may be used. In the method of applying thermal energy, it is difficult to freely control the ejection of liquid droplets, and there is a tendency for the image to vary widely depending on the type of the recording medium. By providing these, these problems are solved, and stable high image quality can be obtained regardless of the type of recording medium.

FIG. 1 shows an example of a line inkjet apparatus suitable for the pretreatment process and the inkjet recording process.
The ink jet apparatus 101 includes head units 110K, 110C, 110M, and 110Y (hereinafter abbreviated as 110) in which heads that eject ink are integrated, and maintenance units 111K, 111C, and 111M that perform head maintenance corresponding to each head unit. 111Y, ink cartridges 107K, 107C, 107M, and 107Y for supplying ink, and sub ink tanks 108K, 108C, 108M, and 108Y (hereinafter referred to as the ink cartridges 107K, 107C, 107M, and 107Y for storing a part of the ink from the ink cartridge and supplying the ink with an appropriate pressure to the head , 108).
Further, a conveyance belt 113 that sucks and conveys the paper 114 (recording medium), conveyance rollers 119 and 121 that support the conveyance belt 113, a tension roller 115 that controls the conveyance belt 113 to maintain an appropriate tension, a paper feed pressing member 122, A transport mechanism including a platen 124 for maintaining the flatness of the transport belt 113, a charging roller 118 for applying electrostatic charge to attract the paper 114, a separation claw 120 for separating the paper 114 from the transport belt 113, and paper discharge A paper discharge roller 116 for carrying the paper, a paper discharge roller 117 for pressing the paper 114, a paper discharge mechanism comprising a paper discharge tray 104 for stocking the discharged paper 114, and a paper feed for stocking the paper 114 to be printed. Separation roller 112 that feeds paper 114 one by one from tray 103 and paper feed tray 103, Counter roller 123 that is a sheet 114 has been reliably attracted to the charged belt, and a paper feeding mechanism including a manual feed tray 105 to be used when the paper feed by manual insertion. A waste liquid tank 109 for collecting waste liquid discharged after maintenance and an operation panel 106 capable of operating the apparatus and displaying the apparatus state are also provided.
The nozzle rows of each head unit are arranged so as to be orthogonal to the conveyance direction of the paper 114, forming a nozzle row having a length longer than the recording area. When the paper 114 is separated from the paper feed tray 103 into a single sheet by a separation roller 112, the paper 114 is brought into close contact with the conveyance belt by a pressure roller (not shown) and fixed on the conveyance belt 113, and passes under the head unit 110. By discharging droplets onto the paper 114, the paper 114 can be patterned at high speed, separated from the transport belt 113 by the separation claw 120, and supported by the paper discharge roller 116 and the paper discharge roller 117 on the paper discharge tray 104. The recorded material is discharged.

FIG. 2 is a diagram showing a head arrangement in the head unit 110 of the apparatus of FIG. In the head unit 110, heads 154A to 154L (hereinafter abbreviated as 154) are fixed to a head outer peripheral member 160, and the heads 154 are fixed in a staggered arrangement so that some of the nozzles overlap.
FIG. 3 is a diagram showing the heads 154 arranged in the head unit 110 of FIG. 2. The heads 154 are provided with nozzles 200 that are opened in a zigzag arrangement in two rows in the nozzle plate 201. A space between the head outer peripheral member 160 and the head outer peripheral member 160 is sealed with a filler 202 to eliminate a gap from the nozzle surface side.

Although FIG. 1 shows a line head ink jet apparatus, the present invention is not limited to this, and a serial ink jet apparatus as shown in FIGS. 4 and 5 is also applicable.
4 and 5, the carriage 131 is slidably held in the main scanning direction by a guide rod 130 and a stay 133 that are horizontally mounted on left and right side plates (not shown). A motor (not shown) moves and scans in the direction of the arrow in FIG.
In the carriage 131, a plurality of ink ejection openings of the head unit 110 that eject recording ink droplets of black (Bk), cyan (C), magenta (M), and yellow (Y) are crossed with the main scanning direction. The ink droplets are mounted with the ink droplet discharge direction facing downward. The carriage 131 is equipped with sub-ink tanks 108 for each color for supplying each color ink to the recording head. The sub ink tank 108 is replenished with ink supplied from an ink cartridge via a recording ink supply tube (not shown).
A double-sided paper feed unit 132 is detachably mounted on the rear surface of the apparatus main body. The double-sided paper feeding unit 132 takes in the paper returned by the reverse rotation of the transport belt 113, reverses it, and feeds the paper again between the counter roller 123 and the transport belt 113. A manual feed tray 105 is provided on the upper surface of the duplex feeding unit 132.
The main scanning motor (not shown) scans the carriage 131 and ejects liquid droplets in response to intermittent paper transport operations in the sub-scanning direction, thereby forming an image in a state where the head is not in contact with the paper. I can do it.

<About pre-processing mechanism>
The inkjet apparatus is provided with a pretreatment liquid coating mechanism. Various coating methods such as roller coating, spray coating, and sublimation coating can be employed.
As an example, a roller coating method incorporated in the ink jet apparatus of FIG. 1 is shown. The pretreatment liquid 135 is assembled on the roller surface by the assembly roller 137 and transferred to the film thickness control roller 138. The pretreatment liquid 135 transferred to the application roller 136 is transferred to the paper 114 that passes between the application counter roller 139 and applied.
By controlling the nip thickness between the film thickness control roller 138 and the application roller 136, the amount of the coating film of the pretreatment liquid 135 transferred to the application roller 136 is controlled. When the pretreatment liquid 135 is not desired to be applied, the movable blade 134 is pressed against the application roller 136 so that the pretreatment liquid 135 does not remain on the application roller 136, and the pretreatment liquid 135 on the surface of the application roller can be scraped off. . If the pretreatment liquid 135 remains on the application roller 136, there is a possibility that functional troubles such as thickening due to drying of the pretreatment liquid 135, adhesion to the application counter roller 139, and application unevenness may occur. By scraping, these functional disorders can be prevented in advance. Reference numeral 140 denotes a pretreatment liquid cartridge.
In addition to such roller coating, the pretreatment liquid 135 may be spray coated by an inkjet method. For example, in the case of the serial ink jet apparatus as shown in FIGS. 4 and 5, the ink can be applied in the same process by exchanging the pretreatment liquid 135, and the application amount and the application position can be controlled with high accuracy and ease. I can do it.
Regardless of which method is used, the pretreatment liquid can be applied in an arbitrary amount at an arbitrary position.

<Control unit>
Next, an outline of the control unit of the inkjet apparatus will be described with reference to FIG. This figure is an overall block diagram of the control unit.
The control unit 300 includes a CPU 301 that controls the entire apparatus, a program executed by the CPU 301, a nozzle surface contamination degree value and a nozzle surface contamination allowable threshold for predetermined ink ejection used in the present invention, drive waveform data, and other fixed data. ROM 302 for storing image data, RAM 303 for temporarily storing image data, non-volatile memory (NVRAM) 304 for holding data even while the apparatus is powered off, various signal processing for image data, rearrangement, etc. An ASIC 305 for processing image processing and other input / output signals for controlling the entire apparatus is provided.
The control unit 300 generates a drive waveform for driving and controlling the host interface (host I / F) 306 for transmitting and receiving data and signals to and from the host side, and the pressure generating means of the recording head 154. Drive control unit 307, recording medium conveyance motor drive control unit 308 for driving the recording medium conveyance motor 309, head unit movement motor drive control unit 310 for driving the head unit (carriage) movement motor 311, maintenance unit movement motor A maintenance unit moving motor drive control unit 312 for driving 313, an ink path valve control unit 314 for controlling opening / closing of an ink path electromagnetic valve 315, a cap suction pump motor 317, and a head ink supply motor 318 are controlled. Liquid feeding suction motor drive control unit 31 , An encoder (not shown) that outputs a detection signal corresponding to the amount and speed of movement of the conveyor belt 113, a detection signal from a sensor 323 that detects environmental temperature and environmental humidity (whichever one may be used), the sub ink tank An I / O 322 for inputting ink amount detection signals and detection signals from other various sensors (not shown) is provided. An operation / display unit 106 for inputting and displaying information necessary for the apparatus is connected to the control unit 300.

The control unit 300 receives print data and the like from the host side such as an information processing device such as a personal computer, an image reading device such as an image scanner, and an imaging device such as a digital camera, via the cable or the network, via the I / F 316.
Then, the CPU 301 reads and analyzes the print data in the reception buffer included in the I / F 306, performs necessary image processing, data rearrangement processing, and the like in the ASIC 305, and reduces the head width of the recording head 154 to one page. Corresponding image data (dot pattern data) is sent to the head drive controller 307 in synchronization with the clock signal.
Then, the CPU 301 reads and analyzes the print data in the reception buffer included in the I / F 306, performs image processing necessary for the ASIC 305, data rearrangement processing, and the like, and transfers the image data to the head drive control unit 307. . The generation of dot pattern data for image output may be performed by storing font data in the ROM 302, for example, or image data is developed into bitmap data by a host-side printer driver and transferred to this apparatus. You may do it.
The head drive control unit 307 selectively applies to the pressure generating means of the recording head 154 based on image data (dot pattern data) corresponding to one page of the recording head 154 input in page units. Drive.
Although not shown, when the pretreatment liquid is applied by roller, it is necessary to control the driving of the application roller group such as the application roller. Therefore, the application motor control unit, the motor to be controlled, and the control Sensor exists.
Further, when the pretreatment liquid is ejected and applied by ink jetting, there is a risk of nozzle clogging due to color mixing unless the maintenance operation is different from that of other inks. Therefore, it is desirable to provide the maintenance unit moving motor for pretreatment separately from the ink.

<Ink cartridge>
The ink cartridge contains ink in a container and has other members and the like appropriately selected as necessary. The container is not particularly limited, and its shape, structure, size, material and the like can be appropriately selected according to the purpose. For example, a container having an ink bag formed of an aluminum laminate film, a resin film, or the like. Can be mentioned.
An example of the ink cartridge will be described with reference to FIGS. FIG. 7 is a view including the case (exterior) of the ink cartridge of FIG.
As shown in FIG. 7, the ink cartridge 200 is filled into the ink bag 241 from the ink inlet 242 and exhausted, and then the ink inlet 242 is closed by fusion. In use, the needle of the apparatus main body is pierced into the ink discharge port 243 made of a rubber member and supplied to the apparatus.
The ink bag 241 is formed of a packaging member such as a non-permeable aluminum laminate film. As shown in FIG. 8, the ink bag 241 is usually housed in a plastic cartridge case 244 and is detachably attached to various ink jet recording apparatuses.
The ink cartridge accommodates ink (ink set) and can be used by being detachably attached to various ink jet recording apparatuses.
If a pretreatment liquid is contained instead of the ink in the ink cartridge, it can be used as a pretreatment liquid cartridge.

The recording medium that is the subject of the present invention has a heat-sensitive recording material in which at least a heat-sensitive recording layer and a protective layer are sequentially laminated on one surface of a support.
The heat-sensitive recording layer contains at least a color former and a developer. As the color former, known leuco dyes in heat-sensitive recording materials can be used alone or in admixture of two or more.
As the leuco dye, for example, a leuco compound of a dye such as triphenylmethane, fluorane, phenothiazine, auramine, spiropyran, or indinophthalide is preferably used. Specific examples thereof include the following.

  3,3-bis (p-dimethylaminophenyl) -phthalide, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (also known as crystal violet lactone), 3,3-bis (p-dimethyl) Aminophenyl) -6-diethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) -6-chlorophthalide, 3,3-bis (p-dibutylaminophenyl) phthalide, 3-cyclohexylamino-6-chloro Fluorane, 3-dimethylamino-5,7-dimethylfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7-methylfluorane, 3-diethylamino-7,3-benzfluorane, 3- Diethylamino-6-methyl-7-chlorofluorane, 3- (Np-tolyl-N-ethyla 6) -6-methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 2- {N- (3'-fluorotrimethylphenyl) amino} -6-diethylaminofluor Oran, 2- {3,6-bis (diethylamino) -9- (o-chloroanilino) xanthylbenzoate lactam}, 3-diethylamino-6-methyl-7- (m-trichloromethylanilino) fluorane, 3-diethylamino -7- (o-chloroanilino) fluorane, 3-di-n-butylamino-7- (o-chloroanilino) fluorane, 3-N-methyl-Nn-amylamino-6-methyl-7-anilinofluorane 3-N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7- Nilinofluorane, 3- (N, N-diethylamino) -5-methyl-7- (N, N-dibenzylamino) fluorane, benzoylleucomethylene blue, 6'-chloro-8'-methoxy-benzoindolino-spiropyran, 6 '-Bromo-3'-methoxy-benzoindolinospiropyran, 3- (2'-hydroxy-4'-dimethylaminophenyl) -3- (2'-methoxy-5'-chlorophenyl) phthalide, 3- (2 '-Hydroxy-4'-dimethylaminophenyl) -3- (2'-methoxy-5'-nitrophenyl) phthalide, 3- (2'-hydroxy-4'-diethylaminophenyl) -3- (2'-methoxy -5'-methylphenyl) phthalide, 3- (2'-methoxy-4'-dimethylaminophenyl) -3- (2'-hydroxy) -4'-chloro-5'-methylphenyl) phthalide, 3- (N-ethyl-N-tetrahydrofurfuryl) amino-6-methyl-7-anilinofluorane, 3-N-ethyl-N- (2 -Ethoxypropyl) amino-6-methyl-7-anilinofluorane, 3-N-methyl-N-isobutyl-6-methyl-7-anilinofluorane, 3-morpholino-7- (N-propyl-tri Fluoromethylanilino) fluorane, 3-pyrrolidino-7-m-trifluoromethylanilinofluorane, 3-diethylamino-5-chloro-7- (N-benzyl-trifluoromethylanilino) fluorane, 3-pyrrolidino- 7- (Di-p-chlorophenyl) methylaminofluorane, 3-diethylamino-5-chloro-7- (α-phenylethylamino) fluora 3- (N-ethyl-p-toluidino) -7- (α-phenylethylamino) fluorane, 3-diethylamino-7- (o-methoxycarbonylphenylamino) fluorane, 3-diethylamino-5-methyl-7- (Α-phenylethylamino) fluorane, 3-diethylamino-7-piperidinofluorane, 2-chloro-3- (N-methyltoluidino) -7- (pn-butylanilino) fluorane, 3- (N-methyl) -N-isopropylamino) -6-methyl-7-anilinofluorane, 3-di-n-butylamino-6-methyl-7-anilinofluorane, 3,6-bis (dimethylamino) fluorene spiro ( 9,3 ′)-6′-dimethylaminophthalide, 3- (N-benzyl-N-cyclohexylamino) -5,6-benzo-7-α- Naphthylamino-4'-bromofluorane, 3-diethylamino-6-chloro-7-anilinofluorane, 3-diethylamino-6-methyl-7-mesitidino-4 ', 5'-benzofluorane, 3-N -Methyl-3-isopropyl-8-methyl-7-anilinofluorane, 3-N-ethyl-N-isoamyl-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7- ( 2 ', 4'-dimethylanilino) fluorane and the like.

As the developer, various known electron accepting substances that react with the leuco dye when heated to develop color can be used. Specific examples thereof include phenolic substances, organic substances as shown below. Or an inorganic acidic substance, or those esters, salts, etc. are mentioned.
Gallic acid, salicylic acid, 3-isopropylsalicylic acid, 3-cyclohexylsalicylic acid, 3,5-di-tert-butylsalicylic acid, 3,5-di-α-methylbenzylsalicylic acid, 4,4′-isopropylidenediphenol, 1,1'-isopropylidenebis (2-chlorophenol), 4,4'-isopropylidenebis (2,6-dibromophenol), 4,4'-isopropylidenebis (2,6-dichlorophenol), 4 , 4'-isopropylidenebis (2-methylphenol), 4,4'-isopropylidenebis (2,6-dimethylphenol), 4,4-isopropylidenebis (2-tert-butylphenol), 4,4 ' -Sec-butylidenediphenol, 4,4'-cyclohexylidenebisphenol, 4,4'-cyclo Xylidenebis (2-methylphenol), 4-tert-butylphenol, 4-phenylphenol, 4-hydroxydiphenoxide, α-naphthol, β-naphthol, 3,5-xylenol, thymol, methyl-4-hydroxybenzoate, 4- Hydroxyacetophenone, novolak type phenolic resin, 2,2'-thiobis (4,6-dichlorophenol), catechol, resorcin, hydroquinone, pyrogallol, phloroglysin, phloroglysin carboxylic acid, 4-tert-octylcatechol, 2,2 ' -Methylenebis (4-chlorophenol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2-dihydroxydiphenyl, ethyl p-hydroxybenzoate, p-hydroxybenzoate Pill, butyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, p-hydroxybenzoic acid-p-chlorobenzyl, p-hydroxybenzoic acid-o-chlorobenzyl, p-hydroxybenzoic acid-p-methylbenzyl, p -Hydroxybenzoic acid-n-octyl, benzoic acid, zinc salicylate, 1-hydroxy-2-naphthoic acid, 2-hydroxy-6-naphthoic acid, zinc 2-hydroxy-6-naphthoate, 4-hydroxydiphenylsulfone, 4 -Hydroxy-4'-chlorodiphenylsulfone, bis (4-hydroxyphenyl) sulfide, 2-hydroxy-p-toluic acid, zinc 3,5-di-tert-butylsalicylate, 3,5-di-tert-butylsalicylic acid Tin, tartaric acid, oxalic acid, maleic acid, citric acid, succinic acid, stearyl Acid, 4-hydroxyphthalic acid, boric acid, thiourea derivative, 4-hydroxythiophenol derivative, bis (4-hydroxyphenyl) acetic acid, bis (4-hydroxyphenyl) acetic acid ethyl, bis (4-hydroxyphenyl) acetic acid -N-propyl, bis (4-hydroxyphenyl) acetic acid-n-butyl, bis (4-hydroxyphenyl) acetic acid phenyl, bis (4-hydroxyphenyl) acetic acid benzyl, bis (4-hydroxyphenyl) acetic acid phenethyl, bis ( 3-methyl-4-hydroxyphenyl) acetic acid, bis (3-methyl-4-hydroxyphenyl) acetic acid methyl, bis (3-methyl-4-hydroxyphenyl) acetic acid-n-propyl, 1,7-bis (4- Hydroxyphenylthio) -3,5-dioxaheptane, 1,5-bis (4-hydroxyphene) Ruthio) -3-oxaheptane, dimethyl 4-hydroxyphthalate, 4-hydroxy-4'-methoxydiphenylsulfone, 4-hydroxy-4'-ethoxydiphenylsulfone, 4-hydroxy-4'-isopropoxydiphenylsulfone, 4 -Hydroxy-4'-propoxydiphenylsulfone, 4-hydroxy-4'-butoxydiphenylsulfone, 4-hydroxy-4'-isobutoxydiphenylsulfone, 4-hydroxy-4-butoxydiphenylsulfone, 4-hydroxy-4'- tert-butoxydiphenylsulfone, 4-hydroxy-4'-benzyloxydiphenylsulfone, 4-hydroxy-4'-phenoxydiphenylsulfone, 4-hydroxy-4 '-(m-methylbenzyloxy) diphenylsulfone, 4-hydride Carboxymethyl -4 '- (p-methyl benzyloxycarbonyl) diphenyl sulfone, 4-hydroxy -4' - (o-methyl benzyloxycarbonyl) diphenyl sulfone, 4-hydroxy -4 '- (p-chloro-benzyloxycarbonyl) diphenyl sulfone.

If necessary, auxiliary additives, such as fillers, surfactants, lubricants, pressure coloring inhibitors, etc., commonly used in this type of heat-sensitive recording material can be added to the heat-sensitive recording layer.
Fillers include calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, kaolin, talc, surface-treated inorganic fine powders such as calcium and silica, urea- Examples thereof include organic fine powders such as formalin resin, styrene / methacrylic acid copolymer, polystyrene resin, and vinylidene chloride resin.
Surfactants include fatty acid metal soaps, polycarboxylic acid type polymer surfactants, sulfates of higher alcohols, sulfates of alkyl polyethers, ethylene oxide adducts of higher alcohols, alkylaryl sulfonic acids Salts, alkyl sulfonic acids, aryl sulfonic acids, phosphate esters, aliphatic phosphate esters, aromatic phosphate esters, polyoxyethylene alkyl sulfate esters, polyoxyethylene aryl sulfate esters, polyoxyethylene alkyl aryl Sulfates, dialkylsulfosuccinates, alkylbenzenesulfonates, polyoxyalkylene alkyl ether phosphates, polyoxyalkylene aryl ether phosphates, polyoxyalkylene alkyls Reel ether phosphate, sodium alkyl sulfate, dioctyl sulfosuccinate sodium salt, polyalkylene glycol (eg, polyoxyethylene nonylphenyl ether), acetylene glycol, ethylene oxide adduct of acetylene glycol, propylene oxide adduct of acetylene glycol, acetylene Examples include glycol ethylene oxide and propylene oxide adducts.
Examples of the lubricant include higher fatty acids and metal salts thereof, higher fatty acid amides, higher fatty acid esters, various animal, vegetable, mineral, and petroleum waxes.

In order to form the heat-sensitive recording layer, various conventional binders can be appropriately used in order to bond and support the leuco dye and the developer on the support. Specific examples thereof include the following.
Polyvinyl alcohol, various modified polyvinyl alcohols, starch and derivatives thereof, cellulose derivatives such as hydroxymethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, ethylcellulose, polyacrylic acid soda, polyvinylpyrrolidone, acrylamide / acrylic acid ester copolymer, Acrylamide / acrylic acid ester / methacrylic acid terpolymers, styrene / maleic anhydride copolymer alkali salts, isobutylene / maleic anhydride copolymer alkali salts, polyacrylamide, sodium alginate, gelatin, casein, etc. In addition to molecules, polyvinyl acetate, polyurethane, polyacrylic acid, polyacrylate, vinyl chloride / vinyl acetate copolymer, polybutyl methacrylate, Emulsion and styrene / butadiene copolymer, such as Ren / vinyl acetate copolymer, such as latex, such as styrene / butadiene / acrylic copolymer.

Resin is used for the protective layer. Examples thereof include polyvinyl alcohol, cellulose derivatives, starch and derivatives thereof, carboxyl group-modified polyvinyl alcohol, polyacrylic acid and derivatives thereof, styrene-acrylic acid copolymers and derivatives thereof, poly (meth) acrylamide and derivatives thereof, Styrene-acrylic acid-acrylamide copolymer, amino group-modified polyvinyl alcohol, epoxy-modified polyvinyl alcohol, polyethyleneimine, aqueous polyester, aqueous polyurtan, isobutylene-maleic anhydride copolymer and derivatives thereof, polyester, polyurethane Acrylate-based (co) polymers, styrene-acrylic copolymers, epoxy resins, polyvinyl acetate, polyvinylidene chloride, polyvinyl chloride and copolymers thereof. Also water-soluble resin is preferable.
In addition to the above-mentioned resin, conventionally used auxiliary additives such as fillers, surfactants, thermofusible substances (or lubricants), pressure coloring inhibitors, etc. can be added to the protective layer. Furthermore, a water-resistant agent can be contained. Examples of the filler and lubricant are the same as those exemplified in the heat-sensitive recording layer.

In addition to the heat-sensitive recording layer and the protective layer, the heat-sensitive recording material may be provided with an under layer between the heat-sensitive recording layer and the protective layer, if necessary, or the back surface of the support (the surface opposite to the heat-sensitive recording layer). A back layer may be provided.
The heat-sensitive recording material can be produced, for example, by applying the above-described coating liquid for layer formation onto a suitable support such as paper or plastic film and drying it.
The support is not particularly limited. For example, high-quality paper, recycled paper, glossy paper, oil-resistant paper, coated paper, art paper, cast coated paper, fine coated paper, resin-laminated paper, polyolefin-based synthetic paper, synthetic resin film Etc. can be used as appropriate.
Recording on the heat-sensitive recording material may be performed using various known heat-sensitive recording devices.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated further more concretely, this invention is not limited from these Examples. In the examples, “%” and “part” are based on mass.

Examples 1 to 8 and Comparative Examples 1 and 2
-Production of recording media (thermal paper) with thermal recording material-
A mixture having the following composition was dispersed using a sand mill so that the average particle diameter was 1.5 μm or less to prepare (A liquid), (B liquid) and (C liquid).
(Liquid A)
-20 parts of 3-dibutylamino-6-methyl-7-anilinofluorane-20 parts of a 10% aqueous solution of polyvinyl alcohol-60 parts of water (liquid B)
・ Bis (4-hydroxy-3,5-dibromophenyl) sulfone 4 parts ・ Di (p-methylbenzyl) oxalate 4 parts ・ 4,4 ′-[oxybis (ethyleneoxy-p-phenylenesulfonyl)]
Polymers based on diphenol 4 parts ・ Silica 4 parts ・ Polyvinyl alcohol 10% aqueous solution 12 parts ・ Water 72 parts (liquid C)
-Aluminum hydroxide 30 parts-Polyvinyl alcohol 10% aqueous solution 30 parts-Water 40 parts

Next, a mixture having the following composition was mixed and stirred to prepare a heat-sensitive recording layer coating solution (solution D). This was coated and dried on the surface of commercially available high-quality paper (basis weight 80 g / m ² ) so that the dry adhesion amount was 5.0 g / m ² to provide a heat-sensitive recording layer.
(Liquid D)
・ (Liquid A) 9.1 parts ・ (Liquid B) 90.9 parts

Subsequently, the mixture of the following composition was mixed and stirred, and the protective layer coating liquid (E liquid) was prepared. This was coated and dried on the surface of the heat-sensitive recording layer-coated paper so that the dry adhesion amount was 2.0 g / m ² to provide a protective layer.
(E liquid)
-(C liquid) 16.7 parts-Polyvinyl alcohol 10% aqueous solution 50 parts-Polyamide epichlorohydrin 12.5% aqueous solution 14 parts-Zinc stearate dispersion (solid content concentration 30%) 2.5 parts-Water 16 .8 parts

Further, the recording medium (thermal paper 1) provided with the thermal recording material was obtained by supercalendering with a metal roll so that the thermal recording surface had a Beck smoothness of 1,500 to 2,500 seconds.
On the other hand, a thermal paper 2 was obtained in the same manner as the thermal paper 1 except that no protective layer was provided.

-Preparation of pretreatment liquid-
The preparation of each pretreatment liquid was performed according to the following procedure.
First, stirring and mixing were performed for 1 hour using the materials shown in the column of the pretreatment liquid in the examples and comparative examples in Table 1 to obtain a uniform mixture. Subsequently, it filtered under pressure using the polyvinylidene fluoride membrane filter with an average hole diameter of 5.0 micrometers, the coarse particle and dust were removed, and each pre-processing liquid was prepared.

-Preparation of ink-
Each dispersion was prepared as in Preparation Examples 1 to 6 below.
(Preparation Example 1)
-Preparation of surface-treated black pigment dispersion-
90 g of carbon black having a CTAB specific surface area of 150 m ² / g and DBP oil absorption of 100 mL / 100 g is added to 3,000 mL of 2.5 N sodium sulfate solution, stirred at a temperature of 60 ° C. and a speed of 300 rpm, and reacted for 10 hours. Oxidation treatment was performed.
The reaction solution was filtered, and the carbon black separated by filtration was neutralized with a sodium hydroxide solution and subjected to ultrafiltration.
The obtained carbon black was washed with water, dried, dispersed in pure water so as to have a solid content of 30% by mass, and sufficiently stirred to obtain a surface-treated black pigment dispersion.
The volume average particle diameter (D50) of the pigment dispersion in this black pigment dispersion was 103 nm. In addition, the measurement of (D50) was performed using the particle size distribution measuring apparatus (the Nikkiso Co., Ltd. make, nano track UPA-EX150).

(Preparation Example 2)
-Preparation of polymer fine particle dispersion containing magenta pigment-
<Preparation of polymer solution A>
After sufficiently replacing the inside of a 1 L flask equipped with a mechanical stirrer, thermometer, nitrogen gas inlet tube, reflux tube, and dropping funnel, 11.2 g of styrene, 2.8 g of acrylic acid, 12.0 g of lauryl methacrylate Then, 4.0 g of polyethylene glycol methacrylate, 4.0 g of styrene macromer, and 0.4 g of mercaptoethanol were mixed and heated to 65 ° C.
Next, 100.8 g of styrene, 25.2 g of acrylic acid, 108.0 g of lauryl methacrylate, 36.0 g of polyethylene glycol methacrylate, 60.0 g of hydroxylethyl methacrylate, 36.0 g of styrene macromer, 3.6 g of mercaptoethanol, azobismethylvaleronitrile A mixed solution of 2.4 g and 18 g of methyl ethyl ketone was dropped into the flask over 2.5 hours.
After dropping, a mixed solution of 0.8 g of azobismethylvaleronitrile and 18 g of methyl ethyl ketone was dropped into the flask over 0.5 hours.
After aging at 65 ° C. for 1 hour, 0.8 g of azobismethylvaleronitrile was added and further aging was performed for 1 hour.
After completion of the reaction, 364 g of methyl ethyl ketone was added to the flask to obtain 800 g of a polymer solution A having a concentration of 50% by mass.

<Preparation of pigment-containing polymer fine particle dispersion>
28 g of polymer solution A, C.I. I. 42 g of Pigment Red 122, 13.6 g of 1 mol / L potassium hydroxide aqueous solution, 20 g of methyl ethyl ketone and 13.6 g of ion-exchanged water were sufficiently stirred, and then kneaded using a roll mill.
The obtained paste was put into 200 g of pure water and stirred sufficiently, and then methyl ethyl ketone and water were distilled off using an evaporator, and further the coarse particles were removed. By pressure filtration with a ride membrane filter, a magenta pigment-containing polymer fine particle dispersion containing 15% by mass of pigment and having a solid content of 20% by mass was obtained.
The volume average particle diameter (D50) of the polymer fine particles in the obtained dispersion was 127 nm. In addition, the measurement of (D50) was performed using the particle size distribution measuring apparatus (the Nikkiso Co., Ltd. make, nano track UPA-EX150).

(Preparation Example 3)
-Preparation of Cyan Pigment-Containing Polymer Fine Particle Dispersion-
A cyan pigment-containing polymer fine particle dispersion was prepared in the same manner as in Preparation Example 2, except that the pigment was changed to a phthalocyanine pigment (CI Pigment Blue 15: 3).
With respect to the polymer fine particles of the obtained dispersion, the volume average particle diameter (D50) measured in the same manner as in Preparation Example 2 was 93 nm.

(Preparation Example 4)
-Preparation of yellow pigment-containing polymer fine particle dispersion-
A yellow pigment-containing polymer fine particle dispersion was prepared in the same manner as in Preparation Example 2, except that the pigment was changed to a monoazo yellow pigment (CI Pigment Yellow 74).
With respect to the polymer fine particles of the obtained dispersion, the volume average particle diameter (D50) measured in the same manner as in Preparation Example 2 was 76 nm.

(Preparation Example 5)
-Preparation of black pigment-containing polymer fine particle dispersion-
A black pigment-containing polymer fine particle dispersion was prepared in the same manner as in Preparation Example 2, except that the pigment was changed to carbon black (manufactured by Degussa, FW100).
With respect to the polymer fine particles of the obtained dispersion, the volume average particle diameter (D50) measured in the same manner as in Preparation Example 2 was 104 nm.

(Preparation Example 6)
-Preparation of surfactant dispersion containing yellow pigment-
Monoazo yellow pigment (CI Pigment Yellow 74, manufactured by Dainichi Seika Kogyo Co., Ltd.) 30.0 parts by mass, polyoxyethylene styrene phenyl ether (nonionic surfactant, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neugen EA-177, HLB value = 15.7) 10.0 parts by mass, ion exchanged water 60.0 parts by mass were prepared. First, the surfactant was dissolved in ion exchanged water, then the pigment was mixed and sufficiently wetted. A wet disperser (Dynomill KDL A type, manufactured by WAB) was filled with zirconia beads having a diameter of 0.5 mm and dispersed at 2,000 rpm for 2 hours to obtain a primary pigment dispersion.
Next, a water-soluble polyurethane resin (Takelac W-5661, manufactured by Mitsui Chemicals, Ltd., active ingredient 35.2% by mass, acid value 40 mgKOH / g, molecular weight 18,000 as a water-soluble polymer compound aqueous solution was added to the primary pigment dispersion. ) Was added and stirred sufficiently to obtain a yellow pigment-containing surfactant dispersion.
It was 62 nm when the volume average particle diameter (D50) of the pigment dispersion in the obtained dispersion liquid was measured with the particle size distribution measuring apparatus (the Nikkiso Co., Ltd. make Nanotrac UPA-EX150).

Next, an ink was prepared by the following procedure using each of the dispersions.
First, a water-soluble organic solvent, a penetrating agent, a surfactant, an antifungal agent, and water shown in the column of the ink composition of Examples and Comparative Examples in Table 1 were mixed and stirred uniformly for 1 hour.
To this mixed solution, a water-dispersible resin was added and stirred for 1 hour, and a pigment dispersion, an antifoaming agent and a pH adjuster were further added and stirred for 1 hour.
The obtained dispersion was subjected to pressure filtration with a polyvinylidene fluoride membrane filter having an average pore size of 5.0 μm to remove coarse particles and dust, and inks of Examples 1 to 8 and Comparative Examples 1 and 2 were obtained. .

  Inkjet recording and thermal recording are performed on the thermal paper 1 and thermal paper 2 using the pretreatment liquids and inks of Examples and Comparative Examples. For the inkjet recording, image density, smear fixability, spur trace, feathering, For color bleed and thermal recording, the image density was evaluated.

<Image density 1 (inkjet recording)>
Ink jet printer shown in FIG. 1 was filled with ink, and solid black was printed on thermal paper at a resolution of 1200 dpi using four colors of CYMK. After printing and drying, the image density was measured using a reflective color spectrocolorimetric densitometer (manufactured by X-Rite). The ink adhesion amount was 9.5 g / m ² .

<Image density 2 (thermal recording)>
Using a thermal printing experimental apparatus having a thin film head manufactured by Panasonic Electronic Device Co., Ltd., with respect to the ink-jet recorded recording medium, head power 0.45 W / dot 1 line recording time 20 msec / L, scanning density 8 × 385 dots / mm Under this condition, a pulse width of 0.2 to 1.2 msec is printed every 1 msec, the print density is measured with a reflection type color spectrophotometric densitometer (manufactured by X-Rite), and the highest value is Dmax (maximum (Color density).

<Smear fixability>
When 3 hours or more have elapsed after printing, the solid image portion printed on the white cotton cloth (manufactured by Toyo Seiki Co., Ltd.) attached to the clock meter (manufactured by Toyo Seiki Co., Ltd.) is reciprocated 10 times, and the smear of the ink adhering to the white cotton cloth is visually observed. And evaluated according to the following criteria.
Rank 5: No dirt at all.
Rank 4: There is a little dirt.
Rank 3: There is dirt, but there is no practical problem.
Rank 2: Dirt is slightly noticeable.
Rank 1: Dirt is noticeable.

<Evaluation of spur marks>
The degree of spur marks on each image print was visually observed and evaluated according to the following criteria.
〔Evaluation criteria〕
A: Not recognized at all.
○: Slightly recognized.
X: Spur marks are clearly recognized.

<Feathering>
The black image portion was observed and compared with a rank sample, and the image quality was evaluated according to the following criteria.
Rank 5: There is no bleeding.
Rank 4: There is slight bleeding.
Rank 3: There is exudation, but there is no practical problem.
Rank 2: There is a slight amount of bleeding.
Rank 1: There is a lot of bleeding.

<Color bleed>
The boundary between black solid and yellow solid was observed, and the image quality was evaluated according to the following criteria by comparing with a rank sample.
Rank 5: No color mixture.
Rank 4: There is a slight color mixture.
Rank 3: There are mixed colors, but there are no practical problems.
Rank 2: There is a little color mixing.
Rank 1: There are many mixed colors.

Details of the materials in the table and the meanings of * to *** are as follows.
FT-251 (Fluorine surfactant: manufactured by Neos)
KF-643 (polyether-modified silicone surfactant: manufactured by Shin-Etsu Chemical Co., Ltd.)
Zonyl FS-300 (Fluorosurfactant: DuPont)
Proxel GXL (manufactured by Arch Chemicals Japan)
KM-72F (silicone defoamer: manufactured by Shin-Etsu Silicone)
*: It has a heat-sensitive recording material provided with a protective layer.
**: Having a heat-sensitive recording material without a protective layer.
***: Not visible due to remarkable background fog of thermal recording layer when ink jet recording is performed. ***: Not visible due to remarkable background fog of thermal recording layer when pretreatment liquid is applied.

DESCRIPTION OF SYMBOLS 101 Inkjet apparatus 103 Paper feed tray 104 Paper discharge tray 105 Manual feed tray 106 Operation panel 107K Ink cartridge 107C Ink cartridge 107M Ink cartridge 107Y Ink cartridge 108K Sub ink tank 108C Sub ink tank 108M Sub ink tank 108Y Sub ink tank 109 Waste liquid tank 110K Head Unit 110C Head unit 110M Head unit 110Y Head unit 111K Maintenance unit 111C Maintenance unit 111M Maintenance unit 111Y Maintenance unit 112 Separation pad 113 Conveying belt 114 Paper (Recording medium)
115 Tension roller 116 Paper discharge roller 117 Paper discharge roller 118 Charging roller 119 Carrying roller 120 Separating claw 121 Carrying roller 122 Paper feed pressing member 123 Counter roller 124 Platen 130 Guide lot 131 Carriage 132 Duplex unit 133 Stay 134 Moving blade 135 Pretreatment liquid 136 Application roller 137 Assembly roller 138 Film thickness control roller 139 Application counter roller 140 Pretreatment liquid cartridge 154A Head 154B Head 154C Head 154D Head 154E Head 154F Head 154G Head 154H Head 154I Head 160 154 Head 154J Head 154J Head 154 Nozzles (staggered arrangement)
201 Nozzle plate 202 Filler 240 Ink cartridge 241 Ink bag 242 Ink inlet 243 Ink outlet 244 Cartridge exterior 300 Controller 301 CPU
302 ROM
303 RAM
304 NVRAM
305 ASIC
306 Host interface 307 Head drive control unit 308 Recording medium conveyance motor drive control unit 309 Recording medium conveyance motor 310 Head unit movement motor drive control unit 311 Head unit movement motor 312 Maintenance unit movement motor drive control unit 313 Maintenance unit movement motor 314 Ink path Valve control unit 315 Electromagnetic valve 316 Liquid feeding suction motor drive control unit 317 Motor of cap suction pump 318 Motor of head ink supply pump 319 Conveying belt 320 Cap suction path 321 Ink supply path 322 I / O
323 sensor

JP 2003-231357 A

Claims (3)

  A pretreatment step for applying a pretreatment liquid for ink jet recording to a recording medium provided with a heat sensitive recording material in which at least a heat sensitive recording layer and a protective layer are sequentially laminated on one surface of the support, and the pretreatment liquid A recording method comprising: an ink jet recording step for forming an image on a recording medium using an aqueous ink jet recording ink; and a heat sensitive recording step for heating a heat sensitive recording material, wherein the pretreatment liquid is a water-soluble aliphatic. Characterized by containing a water-based organic acid, a water-soluble organic monoamine compound, a wetting agent and water, and the ink for ink jet recording contains a water-dispersible colorant, a water-soluble organic solvent, a surfactant, a penetrating agent and water. Recording method.   The recording method according to claim 1, wherein the pretreatment liquid further contains an aliphatic organic acid salt compound or an inorganic metal salt compound. The recording method according to claim 1, wherein the water-dispersible colorant contains any of the following (1) to (3).
(1) A pigment having at least one hydrophilic group on the surface and exhibiting water dispersibility in the absence of a dispersant (self-dispersing pigment)
(2) Pigment dispersion containing pigment, pigment dispersant and polymer dispersion stabilizer (3) Water dispersion of polymer fine particles containing pigment

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