JP6135194B2 - Inkjet pretreatment liquid, image forming method, recorded matter - Google Patents

Description

  The present invention relates to a pretreatment liquid for inkjet, an image forming method using the pretreatment liquid, and a recorded matter obtained by the image forming method.

When printing with a water-based inkjet ink on a recording medium having a coating layer, ink permeation hardly progressed, and dot droplets coalesced and bleeding occurred. As a method for preventing bleeding, it is known to use a pretreatment liquid that reacts with an ink pigment or suppresses solubility.
However, since the conventional pretreatment liquid generates bubbles, there is a problem that uniform application is difficult when applied by the application roller method, and discharge failure is caused by the discharge method using the head. As a method for solving this problem, there is a method of adding an antifoaming agent, but there is a new problem that the stability of the pretreatment liquid is lowered by the addition of the antifoaming agent.
Patent Document 1 relating to the application of the present applicant discloses an image forming method using a treatment liquid containing a specific fluorine-based compound, a cationic polymer compound, an organic acid and water. However, the type of surfactant and the range of the moisture content of the treatment liquid are different, and the foamability is not sufficient.

  An object of the present invention is to provide a pretreatment liquid for ink jet (hereinafter sometimes referred to as a pretreatment liquid) that does not contain an antifoaming agent, is stable, has excellent foaming properties, and can be uniformly applied or discharged.

上記式中、Ｒ１、Ｒ３は、炭素数１〜４のアルコキシ基、炭素数１〜４のパーフルオロアルコキシ基、又は炭素数１〜４のアルキルカルボニルオキシ基を表し、Ｒ２、Ｒ４は炭素数１〜４のパーフルオロアルキル基を表す。また、ｘ、ｙは１〜２４の整数、ｚは１〜２８の整数を表す。 The above problem is solved by the following invention 1).
1) It contains at least water, a water-soluble organic solvent, a water-soluble flocculant composed of a water-soluble cationic polymer, and a fluorosurfactant represented by the following general formula (1), and has a water content of 60% by mass or less. A pretreatment liquid for ink jet.

In the above formulas, R1, R3 is an alkoxy group having a carbon number of 1 to 4, represents a perfluoroalkoxy group, or an alkylcarbonyloxy group having 1 to 4 carbon atoms having 1 to 4 carbon atoms, R2, R4 is 1 carbon atoms Represents a perfluoroalkyl group of ~ 4. X and y are integers of 1 to 24, and z is an integer of 1 to 28.

  ADVANTAGE OF THE INVENTION According to this invention, the pre-processing liquid for inkjet which does not contain an antifoamer, is excellent in foaming property, and can apply or discharge uniformly can be provided.

Hereinafter, the present invention 1) will be described in detail. However, since the following 2) to 8) are also included in the embodiment of the present invention, these will be described together.
2) The pretreatment liquid for inkjet according to 1), which contains a water-soluble cationic polymer comprising an amine or amide derivative and an epihalohydrin as the water-soluble flocculant.
3) The pretreatment liquid for inkjet according to 1) or 2), wherein the water-soluble flocculant contains an organic acid or an organic acid salt.
4) The pretreatment liquid for inkjet according to 3), wherein the organic acid salt is an ammonium lactate salt.
5) A step of applying the inkjet pretreatment liquid according to any one of 1) to 4) to a recording medium, and a step of printing using a water-based ink containing a colorant, a water-soluble organic solvent, and water. An image forming method.
6) The image forming method according to 5), wherein the recording medium has a coating layer on at least one surface of the support.
7) The image forming method according to 5) or 6), wherein the inkjet pretreatment liquid is applied to a recording medium by a coating method or a discharge method using a head.
8) A recorded matter in which an image is formed by the image forming method described in any one of 5) to 7).

<Water-soluble flocculant>
Since the pretreatment liquid of the present invention reacts with the colorant in the ink to break and aggregate the pigment dispersion, a water-soluble cationic polymer is added as a water-soluble flocculant.
A known water-soluble cationic polymer can be used, but a water-soluble cationic polymer comprising an amine or amide derivative and an epihalohydrin is preferable. This polymer contains hydroxyl groups, ammonium cations, etc. in the main chain, and is thought to have a function of enhancing the buffering action and the action of aggregating the pigment when contacted with ink by liberating halogen anions in an aqueous solution. .
Specifically, a water-soluble cationic polymer selected from a polyamine-epihalohydrin copolymer, a polyamide-epihalohydrin copolymer, a polyamide polyamine-epihalohydrin copolymer, and an amine-epihalohydrin copolymer is preferable.

なお、上記式中、Ｒ１〜Ｒ８は、同一でも異なっていても良く、それぞれ炭素数１〜８のアルキル基、ヒドロキシアルキル基、アルケニル基、又はベンジル基のいずれかを示し、Ｘはハロゲン原子（例えば、Ｆ、Ｃｌ、Ｂｒ、Ｉ）を示し、ｎは１又は２を示す。 Particularly preferred water-soluble cationic polymers are the following (A), (B) and (C).
(A) Copolymer represented by the following general formula (2)

In the above formula, R1 to R8 may be the same or different and each represents an alkyl group having 1 to 8 carbon atoms, a hydroxyalkyl group, an alkenyl group, or a benzyl group, and X is a halogen atom ( For example, F, Cl, Br, I) are shown, and n is 1 or 2.

上記式中、Ｘはハロゲン原子（例えば、Ｆ、Ｃｌ、Ｂｒ、Ｉ）を示し、ｍは１以上の整数を示す。また、この共重合体の両末端は、繰り返し単位を構成するモノマーであっても、公知の開始剤等であっても良い。 (B) A copolymer having a repeating unit represented by the following general formula (3)

In the above formula, X represents a halogen atom (for example, F, Cl, Br, I), and m represents an integer of 1 or more. Further, both ends of the copolymer may be a monomer constituting a repeating unit or a known initiator.

上記式中、Ｘはハロゲン原子（例えば、Ｆ、Ｃｌ、Ｂｒ、Ｉ）を示す。 (C) A copolymer of an amine monomer (diethylenetriamine) represented by the following general formula (4), a monomer represented by the following general formula (5), and a monomer represented by the following general formula (6)

In the above formula, X represents a halogen atom (for example, F, Cl, Br, I).

As the amine monomer, triethylenetetraamine, tetraethylenepentamine, iminobispropylamine and the like can be used in addition to the diethylenetriamine represented by the general formula (4). Therefore, the monomer represented by the general formula (4) is preferable.
Examples of other water-soluble cationic polymers include poly (vinyl pyridine) salts, polyalkylaminoethyl acrylates, polyalkylaminoethyl methacrylates, poly (vinyl imidazoles), polyethyleneimines, polybiguanides, polyguanides, polyamines and their derivatives, Or polyallylamine and its derivative are mentioned.
Furthermore, a quaternary ammonium salt type cationic polymer other than the above-mentioned compounds, and in some cases, a water-dispersible cationic polymer may be used as the water-soluble cationic polymer.
Commercially available water-soluble cationic polymers include Unisense KHE100L (manufactured by Senka), PDT-2 (manufactured by Yokkaichi Gosei), SC-506 (manufactured by Hymo), DK-6810 (manufactured by Seiko PMC), Pools kit ( Shimada Shoten).

The weight average molecular weight of the water-soluble cationic polymer varies depending on the type of copolymer, and is preferably 500 to 100,000 in the case of a polyamine-epihalohydrin copolymer, and in the case of a polyamide-epihalohydrin copolymer or a polyamide polyamine-epihalohydrin copolymer. The range of 5 million or less is preferable, and in the case of an amine-epihalohydrin copolymer, 700 to 50,000 is preferable. When the weight average molecular weight exceeds each of the above upper limits, the aqueous solution may not be formed.
The amount of the water-soluble cationic polymer added is preferably 10 to 70% by mass, more preferably 20 to 60% by mass, based on the entire pretreatment liquid. When the addition amount is 10% by mass or more, the effect of suppressing the decrease in the coagulation ability after the drying step is sufficiently exhibited. Further, even if an amount exceeding 70% by mass is added, there is no difference in the effect of improving the image quality from the case of 70% by mass or less, and addition of an organic acid salt or the like can be performed when it is applied to a recording medium. In consideration of not inhibiting the addition of a material imparting wettability, the upper limit is 70% by mass.

In addition to the water-soluble cationic polymer, the pretreatment liquid of the present invention preferably uses an organic acid or an organic acid salt in combination as a water-soluble flocculant. Of these, organic acid ammonium salts are preferred.
Organic acid ammonium salts include ammonium lactate, ammonium acetate, ammonium propionate, ammonium oxalate, ammonium tartrate, ammonium oxalate (diammonium oxalate), diammonium malonate, and ammonium malate in terms of solubility in water. Salts such as ammonium citrate, diammonium hydrogen citrate, triammonium citrate, and ammonium L-glutamate are suitable, and the corrosive power is weak from the viewpoint of corrosion and acid resistance to metal members such as aluminum and SUS. An ammonium lactate salt is particularly preferred.
The addition amount of the organic acid ammonium salt is preferably 1 to 40% by mass, more preferably 10 to 30% by mass, based on the entire pretreatment liquid. If the addition amount is within this range, the effect of suppressing the decrease in the coagulation ability after the drying step is sufficiently exerted, and the coagulation ability of the original pretreatment liquid itself before the drying step is not reduced.

<Surfactant>
The surfactant is added to lower the surface tension of the pretreatment liquid and facilitate the wetting and spreading. However, in the pretreatment liquid of the present invention, the surfactant having excellent foaming property represented by the general formula (1) is used. Use. The x, y, and z in the general formula (1) are not particularly limited as long as they can exhibit foaming properties as a fluorosurfactant, but usually, x and y are 1 to 24, and z is 1. It is about -28, Preferably, x and y are 1-10, z is 11-28, More preferably, x and y are 1-6, z is 20-24.
And by suppressing the moisture content in the pretreatment liquid to 60% by mass or less, the fluidity of the pretreatment liquid is lowered, and bubbles generated at the interface are also uneven and easy to break, so pretreatment with excellent characteristics. A liquid is obtained. The lower limit of the moisture content is not particularly limited, but the pretreatment liquid of the present invention contains water-soluble components, so that the amount of these components can be dissolved. Depending on the type of component, it may be soluble even at 0.1% by weight, but it is preferably 20% by weight or more.
The addition amount of the surfactant is preferably 0.001 to 10% by mass, more preferably 0.05 to 5% by mass of the whole pretreatment liquid. If the addition amount is 0.001% by mass or more, the addition effect can be obtained. However, even if an amount exceeding 10% by mass is added, there is no difference in effect from the case of 10% by mass or less, so the practical upper limit is 10% by mass.

<Water-soluble organic solvent>
To the pretreatment liquid of the present invention, a water-soluble organic solvent is added as a wetting agent in order to adjust its viscosity and fluidity and to provide moisture retention and maintain stability.
Even when water or the like in the pretreatment liquid is vaporized in the nozzle or coating device for applying the pretreatment liquid due to the addition of the water-soluble organic solvent, the increase in the viscosity of the pretreatment liquid is suppressed and the discharge or Application stability can be maintained. From this viewpoint, it is preferable to use a water-soluble organic solvent having a high equilibrium water content as the water-soluble organic solvent. However, from the viewpoint of the coagulation effect of the pretreatment liquid, a water-soluble organic solvent having an equilibrium water content that is not too high is preferred. Here, the equilibrium moisture content means that a mixture of a water-soluble organic solvent and water is released into the air under conditions of constant temperature and humidity, and the water in the solution is evaporated and absorbed in the ink in the air. Says the amount of water when is in equilibrium. The above equilibrium water content is stored for a period of time until there is no change in mass in a petri dish weighing 1 g of a water-soluble organic solvent in a desiccator using a saturated aqueous solution of potassium chloride at a temperature of 23 ± 1 ° C. and a humidity of 80 ± 3%. And can be obtained by the following equation.

上記水溶性有機溶剤の例としては、多価アルコール類、多価アルコールアルキルエーテル類、多価アルコールアリールエーテル類、含窒素複素環化合物、アミド類、アミン類、含硫黄化合物類、プロピレンカーボネート、炭酸エチレンが挙げられる。

Examples of the water-soluble organic solvent include polyhydric alcohols, polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, sulfur-containing compounds, propylene carbonate, carbonic acid Ethylene is mentioned.

From the standpoint of maintaining discharge and coating stability, a water-soluble organic solvent having an equilibrium moisture content in an environment of a temperature of 23 ° C. and a humidity of 80% is preferably 30% by mass or more, and preferably 40% by mass or more.
As such a water-soluble organic solvent, polyhydric alcohols are suitable. Specific examples include 1,2,3-butanetriol [bp (boiling point) 175 ° C./bp at the time of measurement (when not 1 atm. Only described) 33 hPa, equilibrium water content 38% by mass], 1,2,4-butanetriol (bp 190-191 ° C./24 hPa, 41% by mass), glycerin (bp 290 ° C., 49% by mass), diglycerin (bp 270 ° C. / 20 hPa, 38% by mass), triethylene glycol (bp 285 ° C., 39% by mass), tetraethylene glycol (bp 324-330 ° C., 37% by mass), diethylene glycol (bp 245 ° C., 43% by mass), 1,3-butanediol ( bp 203-204 ° C., 35 mass%) and the like.

Further, as a water-soluble organic solvent having an equilibrium water content which is preferable from the viewpoint of the coagulation ability effect of the pretreatment liquid, polyhydric alcohols having an equilibrium water content of less than 30% by mass at a temperature of 23 ° C. and a humidity of 80%. And polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, sulfur-containing compounds, propylene carbonate, ethylene carbonate, and other water-soluble organic solvents.
Specific examples of the polyhydric alcohols include dipropylene glycol (bp 232 ° C.), 1,5-pentanediol (bp 242 ° C.), 3-methyl-1,3-butane diol (bp 203 ° C.), propylene glycol (bp 187 ° C.). ), 2-methyl-2,4-pentanediol (bp 197 ° C.), ethylene glycol (bp 196-198 ° C.), tripropylene glycol (bp 267 ° C.), hexylene glycol (bp 197 ° C.), polyethylene glycol (viscous liquid-solid) ), Polypropylene glycol (bp 187 ° C.), 1,6-hexanediol (bp 253-260 ° C.), 1,2,6-hexane triol (bp 178 ° C.), trimethylolethane [solid, mp (melting point) 199-201 ° C], trimethylolpropane (solid, mp 1 ° C.), and the like.

Specific 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.), Examples include diethylene glycol monobutyl ether (bp 231 ° C.), ethylene glycol mono-2-ethylhexyl ether (bp 229 ° C.), and propylene glycol monoethyl ether (bp 132 ° C.).
Specific examples of the polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether (bp 237 ° C.) and ethylene glycol monobenzyl ether.

Specific examples of the nitrogen-containing heterocyclic compound include 2-pyrrolidone (bp 250 ° C., mp 25.5 ° C., 47-48% by mass), N-methyl-2-pyrrolidone (bp 202 ° C.), 1,3-dimethyl- Examples include 2-imidazolidinone (bp 226 ° C.), ε-caprolactam (bp 270 ° C.), and γ-butyrolactone (bp 204-205 ° C.).
Specific examples of the amides include formamide (bp 210 ° C.), N-methylformamide (bp 199-201 ° C.), N, N-dimethylformamide (bp 153 ° C.), N, N-diethylformamide (bp 176-177 ° C.). Etc.
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 (bp159 ° C), N-phenylethanolamine (bp282-287 ° C), 3-aminopropyldiethylamine (bp169 ° C) and the like.
Specific examples of the above sulfur-containing compounds include dimethyl sulfoxide (bp 139 ° C.), sulfolane (bp 285 ° C.), thiodiglycol (bp 282 ° C.) and the like.

Of the above water-soluble organic solvents, polyhydric alcohols are preferred in view of the two points of discharge and maintenance of coating stability and the coagulation effect of the pretreatment liquid. Particularly, glycerin, 1,3-butanediol, 3-methyl -1,3-butanediol is preferred.
The content of the water-soluble organic solvent in the pretreatment liquid is not particularly limited, but is usually 5 to 80% by mass, preferably 10 to 20% by mass. When the content is 80% by mass or less, the drying property of the recording medium to which the pretreatment liquid is attached does not deteriorate depending on the type of the water-soluble organic solvent. In addition, the amount of the flocculant added in the pretreatment liquid becomes a sufficient amount, and the coagulation ability of the pretreatment liquid is not greatly reduced. Further, if the content is 5% by mass or more, the water contained in the pretreatment liquid is not easily vaporized, and the water is vaporized to increase the viscosity of the pretreatment liquid, resulting in problems in the coating process. There is no such thing.

In addition to the water-soluble organic solvent, a material that dissolves in an aqueous solution and exhibits a function as a wetting agent can be used in combination, but a saccharide is preferable. 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 widely present in nature such as a-cyclodextrin and cellulose. The derivatives of these saccharides include reducing sugars of the saccharides {for example, sugar alcohol [general formula: HOCH ₂ (CHOH) nCH ₂ OH (where n represents an integer of 1 to 6)}} , Oxidized sugar (eg, aldonic acid, uronic acid, etc.), amino acid, thioic acid and the like.
Among these, sugar alcohols are preferable, and specific examples include maltitol and sorbit.

<Other ingredients>
In addition to the above components, the pretreatment liquid of the present invention may contain various additives such as a penetrant, a pH adjuster, an antiseptic / antifungal agent, and a rust preventive as necessary.
(Penetration agent)
The pretreatment liquid of the present invention preferably contains at least one non-wetting agent polyol compound or glycol ether compound having 8 to 11 carbon atoms as a penetrant. Moreover, what has the solubility between 0.2-5 mass% in 25 degreeC water is preferable.
Among them, 2-ethyl-1,3-hexanediol [solubility: 4.2% (25 ° C.)], 2,2,4-trimethyl-1,3-pentanediol [solubility: 2.0% (25 ° C.)] ] Is particularly preferable.

Examples of other non-wetting agent polyol compounds include 2-ethyl-2-methyl-1,3-propanediol, 3,3-dimethyl-1,2, -butanediol, 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- Aliphatic diols such as 1,2-diol are listed.
Other penetrants that can be used in combination are not particularly limited as long as they can be dissolved in a pretreatment liquid and adjusted to desired physical properties, and are 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 content of the penetrant in the pretreatment liquid is preferably 0.1 to 5.0% by mass. When the content is 0.1% by mass or more, the effect of allowing the pretreatment liquid to permeate can be obtained. When the content is 5.0% by mass or less, since the solubility of the penetrant in the solvent is low, it is separated from the solvent. Thus, the effect of improving permeability is not saturated.

(PH adjuster)
The pH adjuster is not particularly limited as long as it can adjust the pH to 4 to 8 without adversely affecting the pretreatment liquid to be prepared, and can be appropriately selected according to the purpose. If the pH of the pretreatment liquid exceeds 8, the aggregation effect may be greatly reduced. Moreover, when pH becomes less than 4, the roller of the conveyance member which contacts a pretreatment liquid will corrode, and a failure | damage may generate | occur | produce in a conveyance function.
Preferred pH adjusters 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 element 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.

(Antiseptic and antifungal agent)
Examples of antiseptic / antifungal agents include sodium dehydroacetate, sodium sorbate, sodium 2-pyridinethiol-1-oxide, sodium benzoate, sodium pentachlorophenol, 1,2-benzisothiazolin-3-one sodium compound, and the like. Preferably used.
(Rust inhibitor)
As the rust preventive agent, for example, acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, dicyclohexylammonium nitrite, 1,2,3-benzotriazole and the like are preferably used.

<Water-based ink>
The water-based ink used for ink jet recording in combination with the pretreatment liquid of the present invention is not particularly limited, and can be appropriately selected from conventionally known ones.
The known water-based ink contains at least a colorant, a water-soluble organic solvent, and water, and various kinds such as a surfactant, a wetting agent, a penetrating agent, a pH adjusting agent, an antiseptic / antifungal agent, and a rust preventive agent as necessary. Although containing an additive, the thing similar to the case of a pre-processing liquid can be used except a coloring agent. Therefore, only the colorant will be described here.

<Colorant>
As the colorant for the ink, a pigment is mainly used from the viewpoint of weather resistance, but in order to adjust the color tone, a dye may be used in combination as long as the weather resistance is not deteriorated.
There is no restriction | limiting in particular as a pigment, Although it can select suitably according to the objective, For example, the inorganic pigment, organic pigment, etc. for black or color are used. These pigments may be used alone or in combination of two or more.
The content of the colorant in the ink is preferably 2 to 15% by mass and more preferably 3 to 12% by mass in terms of solid content. If the content is less than 2% by mass, the chroma and density of the recorded matter may be lowered, and if it exceeds 15% by mass, the viscosity of the ink may be increased and the ejection stability may be lowered.

The inorganic pigment was produced by a known method such as titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, and chrome yellow, or a contact method, furnace method, thermal method, or the like. Carbon black can be used.
Examples of the organic pigment include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments), polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments). , Dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinofullerone pigments, etc.), dye chelates (eg basic dye chelates, acid dye chelates), nitro pigments, nitroso pigments, aniline black, etc. The Of these pigments, those having good affinity with water are particularly preferably used.

The volume average particle diameter (D50) of the pigment is preferably 150 nm or less, more preferably 100 nm or less in the ink. When the volume average particle diameter (D50) exceeds 150 nm, the ejection stability rapidly decreases, and nozzle clogging and ink bending are likely to occur. On the other hand, when the volume average particle diameter (D50) is 100 nm or less, the ejection stability is improved and the chroma of the image is also improved.
The content of the pigment in the ink is preferably about 1 to 15% by mass, more preferably about 2 to 12% by mass.

<Recording medium>
The recording medium to which the pretreatment liquid of the present invention is applied is not particularly limited as long as it is a printing paper having a coating layer, and can be appropriately selected according to the purpose. Here, the printing paper having a coating layer refers to a paper in which a coating is applied to the surface of the base paper to enhance the aesthetics and smoothness, and may be either front-back double-sided coating or single-sided coating. The paint described here is made by mixing a white pigment such as kaolin or calcium carbonate and a binder such as starch.
Printing paper having a coating layer is divided into art paper, coated paper, lightweight coated paper, cast paper, fine coated paper, and the like.

<Image forming method>
A preferred embodiment of the image forming method of the present invention will be described.
In normal cases, image formation is performed by applying a pretreatment liquid of the present invention to a recording medium, drying the pretreatment liquid, and ejecting water-based ink onto the recording medium to which the pretreatment liquid is adhered by an ink jet method. The process of forming. The recorded matter of the present invention is obtained through these steps.
Hereinafter, each of these steps will be described.

(Process to attach pretreatment liquid)
The step of attaching the pretreatment liquid is not particularly limited as long as the pretreatment liquid is uniformly attached to the surface of the recording medium, and examples thereof include a coating method and a discharge method using a head.
Examples of 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 coating, and smoothing. Examples thereof include a 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.
Wet adhesion amount to the recording medium of the pretreatment liquid (coating weight of the pretreatment liquid prior to drying of the recording medium) is preferably 0.1~10.0g / ^{m 2,} 1.0~3.0g / ^{m 2} is more preferable. When the wet adhesion amount is 0.1 g / m ² or more, the image quality (density, saturation, color bleeding, feathering) of the recorded matter is improved. Moreover, if it is 10.0 g / m < ² > or less, the texture of a recorded matter will not be impaired, the drying process will not take time, and there will be no problem in terms of cost. Moreover, agglomeration effects beyond the 10.0 g / ^{m 2} is the same as that in the case of 10.0 g / ^{m 2} or less.

(Process of drying the pretreatment liquid that has adhered)
As a step of drying the pretreatment liquid attached to the recording medium, the pretreatment liquid attached to the recording medium is transferred to a conveyance member that contacts from the pretreatment liquid application step to image formation by ink ejection. An artificial drying method may be used to such an extent that the image quality is not deteriorated due to the occurrence of the failure or accumulation of dirt. The drying temperature is preferably 40 to 130 ° C, more preferably 80 to 100 ° C. If the drying temperature is less than 40 ° C., it takes too much drying time, and if it exceeds 130 ° C., the recording medium may be abnormal.
Examples of the drying method include a heat drum method, an oven method, a hot air blowing method, a preheater method, and a heating roller method. Moreover, you may combine these systems.
Further, “drying” after applying the pretreatment liquid does not mean that the pretreatment liquid is absorbed into the recording medium and apparently becomes dry, but the liquid in the pretreatment liquid such as moisture is not. It means that it evaporates and cannot solidify and solidifies.

(Step of attaching ink)
The step of attaching the ink is a step of recording an image on the recording medium by attaching the pretreatment liquid and applying the ink to the recording medium that has undergone the pretreatment liquid drying step.
As a method of attaching ink, a method of attaching ink to a recording medium by applying a stimulus (energy) to the ink with a predetermined apparatus and ejecting the ink is suitable, and a known inkjet recording method may be applied. Examples of such an ink jet recording method include an ink jet recording method in which an image is recorded on a continuous recording medium using a lined head, and an ink jet recording method in which a head is scanned.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated further more concretely, this invention is not limited by these Examples. “%” Other than the yield is “% by mass”.

Examples 1 to 23, Comparative Examples 1 to 6
<Production of water-soluble flocculant (water-soluble cationic polymer comprising an amine or amide derivative and epihalohydrin)>

[Production Example 1]
A 1000 mL glass autoclave equipped with a stirrer, thermometer, and nitrogen gas inlet tube was charged with 200.0 g (2.218 mol) of 50% dimethylamine and 291.0 g (1.477 mol) of 30% trimethylamine, and nitrogen. After the replacement, 274.0 g (2.961 mol) of epichlorohydrin was introduced over 2 hours while cooling to 40 ° C., held at the same temperature for 1 hour, then heated to 80 ° C. and aged for 3 hours. I let you. After cooling, the pH was adjusted to 5.0 with 77.0 g of 35% hydrochloric acid and 0.82 g of 75% phosphoric acid (relative to the solid content of 730 ppm), and the water-soluble cationic polymer having a solid content concentration of 58% and a quaternization rate of 91%. 840.0 g was obtained. The yield was 99.7%.
The viscosity of this water-soluble cationic polymer was 21 mPa · s, and the content of 1,3-dichloro-2-propanol (DCH) was 100 ppm or less.
Dimethylamine and trimethylamine were charged in the form of an aqueous solution. The above charge amount represents a net conversion value of each amine.

[Production Example 2]
In the same manner as in Preparation Example 1, 200.0 g (2.218 mol) of 50% dimethylamine and 218.5 g (1.109 mol) of 30% trimethylamine were charged, and after nitrogen substitution, the reaction was allowed to proceed to epitaxy while cooling to 40 ° C. 257.0 g (2.777 mol) of chlorohydrin was introduced over 2 hours, held at the same temperature for 1 hour, then heated to 80 ° C. and aged for 3 hours. After cooling, the pH is adjusted to 5.0 with 54.5 g of 35% hydrochloric acid and 0.92 g of 75% phosphoric acid, and further diluted with pure water so that the solid content concentration becomes 60% to obtain a water-soluble cationic polymer. It was.
The viscosity of this water-soluble cationic polymer was 36 mPa · s.

[Production Example 3]
In the same manner as in Production Example 1, 200.0 g (2.218 mol) of 50% dimethylamine and 174.8 g (0.887 mol) of 30% trimethylamine were charged, purged with nitrogen, and then cooled to 40 ° C. 246.0 g (2.659 mol) of chlorohydrin was introduced over 2 hours, held at the same temperature for 1 hour, then heated to 80 ° C. and aged for 3 hours. After cooling, the pH is adjusted to 5.0 with 46.2 g of 35% hydrochloric acid and 0.87 g of 75% phosphoric acid, and further diluted with pure water so that the solid content concentration becomes 60% to obtain a water-soluble cationic polymer. It was.
The viscosity of this water-soluble cationic polymer was 40 mPa · s.

[Production Example 4]
In the same manner as in Preparation Example 1, 200.0 g (2.218 mol) of 50% dimethylamine and 145.7 g (0.739 mol) of 30% trimethylamine were charged, purged with nitrogen, and then cooled to 40 ° C. 239.0 g (2.583 mol) of chlorohydrin was introduced over 2 hours, held at the same temperature for 1 hour, then heated to 80 ° C. and aged for 3 hours. After cooling, the pH is adjusted to 5.0 with 38.5 g of 35% hydrochloric acid and 0.82 g of 75% phosphoric acid, and further diluted with pure water so that the solid content concentration becomes 60% to obtain a water-soluble cationic polymer. It was.
The viscosity of the water-soluble cationic polymer was 48 mPa · s.

[Production Example 5]
In the same manner as in Preparation Example 1, 200.0 g (2.218 mol) of 50% dimethylamine and 145.7 g (0.739 mol) of 30% trimethylamine were charged, purged with nitrogen, and then cooled to 40 ° C. 239.0 g (2.583 mol) of chlorohydrin was introduced over 2 hours, held at the same temperature for 1 hour, then heated to 80 ° C. and aged for 3 hours. After cooling, the pH is adjusted to 4.0 with 38.5 g of 35% hydrochloric acid and 1.6 g of 75% phosphoric acid, and further diluted with pure water so that the solid concentration is 60% to obtain a water-soluble cationic polymer. It was.
The viscosity of the water-soluble cationic polymer was 48 mPa · s.

[Production Example 6]
In the same manner as in Production Example 1, 200.0 g (2.218 mol) of 50% dimethylamine and 291.0 g (1.477 mol) of 30% trimethylamine were charged, and after nitrogen substitution, the epitaxy was performed while cooling to 40 ° C. Chlorohydrin (274.0 g, 2.961 mol) was introduced over 2 hours, maintained at the same temperature for 1 hour, then heated to 80 ° C. and aged for 3 hours. After cooling, the pH was adjusted to 5.0 with 77.0 g of 35% hydrochloric acid, and further diluted with pure water so that the solid concentration was 60% to obtain a water-soluble cationic polymer.
The viscosity of this water-soluble cationic polymer was 20 mPa · s.
From the comparison with Preparation Example 1, it can be seen that pH 5.0 can be adjusted only by 77.0 g of 35% hydrochloric acid without using 0.82 g of 75% phosphoric acid.

[Production Example 7]
A water-soluble cationic polymer having a solid concentration of 58% and a quaternization ratio of 91% was prepared in exactly the same manner as in Production Example 1. Next, 6.4 g (0.022 mol) of 3-chloro-2-hydroxypropyltrimethylammonium chloride and 4.7 g (0.022 mol) of glycidyltrimethylammonium chloride were added to the aqueous solution of this polymer as a quaternizing agent, The mixture was stirred at 60 ° C. for 2 hours to obtain a water-soluble cationic polymer aqueous solution.
The resulting aqueous polymer solution had a pH of 4.8 and a quaternization rate of 99%. The solution viscosity increased to 23 mPa · s.

[Production Example 8]
A 500 mL four-necked flask equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube was charged with 95.1 g of water and 131.8 g (0.8 mol) of 58% trimethylamine hydrochloride aqueous solution, and nitrogen gas was introduced. Under cooling, 74.0 g (0.8 mol) of epichlorohydrin was added dropwise over 3 hours while cooling so as not to exceed 40 ° C. After completion of the dropwise addition, the temperature was raised to 80 ° C. and the reaction was performed for 1 hour. Thereafter, the mixture was cooled to 30 ° C., 36.1 g (0.4 mol) of 50% dimethylamine aqueous solution and 14.8 g (0.2 mol) of calcium hydroxide were added, the temperature was raised to 80 ° C., and the reaction was performed over 1 hour. I let you. Thereafter, the reaction solution was adjusted with hydrochloric acid and water to have a pH of 4.0 and a solid content concentration of 50% to obtain a water-soluble cationic polymer aqueous solution.

[Production Example 9]
In a 500 mL four-necked flask equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube, 36.8 g of water, 157.6 g of 30% trimethylamine aqueous solution (0.8 mol), and 36% of 50% dimethylamine aqueous solution. 1 g (0.4 mol) and diethylamine 7.3 g (0.1 mol) were charged, and epichlorohydrin 92.5 g (1.0 mol) was added while cooling so as not to exceed 40 ° C. under introduction of nitrogen gas. It was dripped over 4 hours. After completion of the dropwise addition, the temperature was raised to 80 ° C., and the reaction was carried out at that temperature for 2 hours. Thereafter, the reaction solution was cooled to 30 ° C., and adjusted with sulfuric acid and water to have a pH of 3.9 and a solid content concentration of 50% to obtain a water-soluble cationic polymer aqueous solution.

[Production Example 10]
495 g (4.8 mol) of diethylenetriamine was charged into a 3 L four-necked round bottom flask equipped with a thermometer, a condenser, a stirrer, and a nitrogen introduction tube, and 877 g (6.0 mol) of adipic acid was added while stirring. The temperature was raised while removing generated water out of the system, and the mixture was reacted at 150 ° C. for 5 hours, and then 1000 g of water was gradually added to obtain a polyamide polyamine-containing liquid. This polyamide polyamine-containing liquid had a solid content of 52.1%, and the viscosity at 25 ° C. when the solid content was 50% was 380 mPa · s.
100 g of the polyamide polyamine-containing solution (0.214 mol as amino group), 3.8 g of acetic acid (30 equivalent%) and 4.3 g of 30% aqueous sodium hydroxide (15 equivalent%) were charged, and 6.7 g of water was added. The solid content was 50%. Next, 19.8 g (100 equivalent%) of epichlorohydrin was added dropwise at 30 ° C. over 1 hour, and held at the same temperature for 1 hour, and 0.8 g (2 equivalent%) of sodium metabisulfite was added, It was kept at the same temperature for 5 hours after the start of epichlorohydrin addition. Next, 1.1 g (10 equivalent%) of 98% sulfuric acid and 127.0 g of water were added to adjust the solid content to 30%, and then heated to 75 ° C. Furthermore, after maintaining at this temperature until the viscosity at 25 ° C. of the reaction solution reached 300 mPa · s, 40.5 g of water was added to make the solid content 26%, and after cooling to 25 ° C. or lower, 30% sulfuric acid was added. Was adjusted to pH 3.5 with 88% formic acid to obtain a water-soluble cationic polymer aqueous solution having a viscosity of 51.6 mPa · s at a solid content concentration of 25.0% and 15%. .

[Production Example 11]
Into a 1 L four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas introduction tube, 443.85 parts of water and 41.27 parts of diethylenetriamine were charged, and epichlorohydrin 111. After dropwise addition of 04 parts over 1.5 hours so as not to exceed 40 ° C., 19.4 parts of octahydro-4,7-methanoindene-1 (2), 5 (6) -dimethanamine were added and stirred for 30 minutes. 18.51 parts of epichlorohydrin was added dropwise over 0.5 hours so as not to exceed 40 ° C., and the temperature was raised to 70 ° C. and kept for 1.5 hours. Next, 30% aqueous sodium hydroxide solution was added to adjust the pH to 7.5, and the mixture was kept warm for 1.5 hours. Thereafter, the pH was adjusted to 3.5 with a 30% aqueous sulfuric acid solution and cooled to complete the reaction.
The obtained water-soluble cationic polymer aqueous solution had a solid content of 30.2%, a viscosity of 7.6 mPa · s (solid content concentration of 10%), and a pH of 3.9.

[Production Example 12]
A 1 L four-necked flask equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube was charged with 657.2 parts of water, 58.4 parts of triethylenetetramine and 108 parts of 50% dimethylamine, and nitrogen gas was introduced. Below, 192.4 parts of epichlorohydrin was added dropwise over 1.5 hours so as not to exceed 40 ° C., and then the temperature was raised to 70 ° C. and kept for 1.5 hours. Next, the pH was adjusted to 7.5 with a 30% aqueous sodium hydroxide solution, and the mixture was further kept at 70 ° C. for 1.5 hours, adjusted to a pH of 3.5 with a 30% aqueous sulfuric acid solution, and cooled to complete the reaction.
The obtained aqueous water-soluble cationic polymer solution had a solid content concentration of 29.9%, a viscosity of 20 mPa · s (solid content concentration of 10%), and a pH of 3.5.

<Preparation of pretreatment liquid>
The materials shown in each column of Examples and Comparative Examples in Tables 1 to 3 below were stirred and mixed for 1 hour to prepare pretreatment liquids.
In the table, (* 1) indicates that the water-soluble cationic polymer was concentrated by heating so that the solid content concentration was 50.0%.
Moreover, compound (1) -a- (1) -e is a compound of the following structures in the said General formula (1).
(1) -a: R1 = R3 = OCH ₃ , R2 = R4 = CF ₃ , x = y = 4, z = 21
_{(1) -b: R1 = R3} = OC 2 H 5, R2 = R4 = C 2 F 5, x = y = 4, z = 21
(1) -c: R1 = R3 = OCF ₃ , R2 = R4 = CF ₃ , x = y = 4, z = 21
(1) -d: R1 = R3 = OCF ₃ , R2 = R4 = C ₂ F ₅ , x = y = 4, z = 21
(1) -e: R1 = R3 = O (CO) CH ₃ , R2 = R4 = C ₂ F ₅ , x = y = 6,
z = 20

Compounds (2) to (5) are compounds represented by the following chemical formulas [Chemical Formula 7] to [Chemical Formula 10], respectively. However, M in the formulas represents K, Rf represents a _C 4 _{F 9.}

Details of the materials indicated by the substance names or trade names in the table are as follows.
-Ammonium lactate salt: Musashino Chemical Laboratory, solid content 66.2%
・ Lactic acid: Fuso Chemical Co., Ltd., solid content 90%
1-amino-2-propanol: Tokyo Chemical Industry Co., Ltd., active ingredient 98%
PAS-H-1L: polydiallyldimethylammonium chloride (Nittobo, solid content 28%)
C20: polyamine (manufactured by MT Aquapolymer, solid content 50%)
WS-4030: polyamide, epichlorohydrin (manufactured by Seiko PMC, solid content 25%)
-Charol DC-303P: cationic property of dialkyldiallyl-quaternary ammonium salt
Polymer compound (Daiichi Kogyo Seiyaku Co., Ltd., solid content 41%)
Softanol EP-7025: polyoxyalkylene alkyl ether
(Nippon Shokubai Co., Ltd., 100% active ingredient)

About each pre-processing liquid of the said Example and comparative example, the characteristic was evaluated as follows. The results are summarized in Table 4.

Evaluation 1 <Foamability>
10 mL of each pretreatment liquid was put into a 100 mL graduated cylinder, and this graduated cylinder was immersed in a constant temperature water bath at 10 ° C. for 30 minutes or more to stabilize the liquid temperature of the evaluation pretreatment liquid. Next, an air injection tube having an inner diameter of 1 mm was attached to the graduated cylinder, and the tip of the air injection tube was attached to a height of 5 mm from the bottom of the pretreatment liquid. Furthermore, the air pressure of the pressurizing device was set to 20 gf / cm ² , the time of measurement was started with a stopwatch at the same time as opening the valve of the pressurizing device, and the memory bubble height of the graduated cylinder after 30 seconds was measured. Evaluation was based on criteria.
[Example: When the scale is 100 mL → 100-10 (sample amount) = height 90 mL]
In addition, when the scale reached 100 mL within 30 seconds, the foamability test was stopped.
〔Evaluation criteria〕
◎: When there is no bubble height ○: Bubble height can be confirmed a little, but the height is less than 10 mL after 30 seconds △: Bubble height can be confirmed, and the height is less than 90 mL after 30 seconds In case of x: When the scale reaches 100 mL within 30 seconds

Evaluation 2 <Image quality (beading)>
After applying 1.9 g / m ^{2 of} each pretreatment liquid to the coating layer surface of the recording medium having a coating layer (Lumiart gloss 90 gsm manufactured by STORA ENSO) by a roller coating method, a negative charge is applied by an aqueous inkjet method. The ink in which the pigment particles were dispersed was ejected by a single pass method with a resolution of 600 × 600 dpi to form an image. The evaluation image was a green solid image having an ink adhesion amount of 3.2 × 10 ⁻⁶ g / m ² in which cyan and yellow were formed at a ratio of 1.2: 1.0, and was visually determined according to the following criteria.
〔Evaluation criteria〕
A: No beading is observed.
○: Slight beading is observed when looking closely.
Δ: Slight beading is observed.
X: There is clearly beading.

In Examples 1 to 23, the specific surfactant according to the present invention was added, and the water content was 60% or less. Therefore, no foam height was observed in the foaming test.
On the other hand, in Comparative Example 1, since the water content exceeded 60%, the foam height reached the scale of 100 mL within 30 seconds in the foamability test. In Comparative Example 2, the amount of water was 60% or less, but the foam height could be confirmed because the surfactant did not satisfy the requirements of the present invention. In Comparative Examples 3 to 6, since the surfactant did not satisfy the requirements of the present invention and the water content exceeded 60%, the foam height reached 100 mL within 30 seconds in the foaming test.

JP 2011-230401 A

Claims (8)

It contains at least water, a water-soluble organic solvent, a water-soluble flocculant composed of a water-soluble cationic polymer, and a fluorine-based surfactant represented by the following general formula (1), and has a water content of 60% by mass or less. A pretreatment liquid for inkjet.

In the above formula, R 1 and R 3 represent an alkoxy group having 1 to 4 carbon atoms, a perfluoroalkoxy group having 1 to 4 carbon atoms, or an alkylcarbonyloxy group having 1 to 4 carbon atoms, and R 2 and R 4 represent 1 carbon atom. Represents a perfluoroalkyl group of ~ 4. X and y are integers of 1 to 24, and z is an integer of 1 to 28.   2. The inkjet pretreatment liquid according to claim 1, wherein the water-soluble flocculant includes a water-soluble cationic polymer composed of an amine or amide derivative and epihalohydrin.   The inkjet pretreatment liquid according to claim 1, comprising an organic acid or an organic acid salt as the water-soluble flocculant.   The inkjet pretreatment liquid according to claim 3, wherein the organic acid salt is an ammonium lactate salt.   It has the process of providing using the aqueous | water-based ink containing the process which provides the recording medium with the inkjet pre-processing liquid in any one of Claims 1-4, and a coloring agent, a water-soluble organic solvent, and water. An image forming method.   6. The image forming method according to claim 5, wherein the recording medium has a coating layer on at least one surface of the support.   7. The image forming method according to claim 5, wherein the inkjet pretreatment liquid is applied to a recording medium by a coating method or a discharge method using a head.   A recorded matter, wherein an image is formed by the image forming method according to claim 5.