JP2020105325A - Aqueous ink for inkjet recording and inkjet recording method - Google Patents

Abstract

To provide aqueous ink for inkjet recording which can be fixed even to coat paper by drying at lower temperature for shorter time.SOLUTION: The aqueous ink for inkjet recording includes a coloring agent and water, the coloring agent includes a resin-dispersed pigment and further includes a vinyl chloride-acrylic copolymer emulsion having a glass transition temperature of 50°C or higher and methacrylic acid ions, and a solid content blending amount (E) of the vinyl chloride-acrylic copolymer emulsion and the blending amount (A) of the methacrylic acid ions in the total amount of the aqueous ink satisfies A/E≥0.01.SELECTED DRAWING: None

Description

The present invention relates to a water-based ink for inkjet recording and an inkjet recording method.

A water-based ink containing a vinyl chloride-acrylic copolymer has been proposed as a water-based ink for inkjet recording having excellent fixability on coated paper (Patent Document 1).

JP, 2014-19811, A

However, in order to fix the water-based ink containing the vinyl chloride-acrylic copolymer on the coated paper, heating and drying at high temperature for a long time are required.

Therefore, an object of the present invention is to provide a water-based inkjet recording ink that can be fixed on coated paper at a lower temperature and a shorter drying time.

In order to achieve the above object, the aqueous ink for inkjet recording of the present invention,
A water-based ink jet recording ink containing a colorant and water,
The colorant includes a resin dispersed pigment,
further,
A vinyl chloride-acrylic copolymer emulsion having a glass transition temperature of 50° C. or higher;
Methacrylate ion,
Including
The solid content of the vinyl chloride-acrylic copolymer emulsion (E) and the content of the methacrylate ion (A) in the total amount of the water-based ink satisfy A/E≧0.01. And

The water-based ink for inkjet recording of the present invention has a glass transition temperature in a predetermined range in addition to a vinyl chloride-acrylic copolymer emulsion, and by containing a predetermined amount of methacrylate ion, at a lower temperature and a shorter drying time, It can be fixed on coated paper.

FIG. 1 is a schematic diagram showing the configuration of an example of an inkjet recording apparatus of the present invention.

In the present invention, the "coated paper" means, for example, plain paper having pulp as a main constituent, such as high-grade printing paper and intermediate-grade printing paper, coated with the purpose of improving smoothness, whiteness, glossiness, etc. The agent is applied, and specifically, high quality coated paper, medium quality coated paper and the like can be mentioned. The water-based ink for ink-jet recording (hereinafter, also referred to as “water-based ink” or “ink”) and the ink-jet recording method of the present invention can be suitably used for ink-jet recording on coated paper, but are not limited thereto. However, it can also be used for inkjet recording on a recording medium other than coated paper such as plain paper, glossy paper, and matte paper.

The water-based ink of the present invention will be described. The water-based ink of the present invention contains a colorant and water.

The colorant includes a resin dispersed pigment. The resin-dispersed pigment is dispersible in water with, for example, a pigment-dispersing resin (resin dispersant). The resin-dispersed pigment is not particularly limited, and examples thereof include carbon black, inorganic pigments and organic pigments. Examples of the carbon black include furnace black, lamp black, acetylene black, channel black and the like. Examples of the inorganic pigments include titanium oxide, iron oxide-based inorganic pigments, carbon black-based inorganic pigments, and the like. Examples of the organic pigment include azo pigments such as azo lake, insoluble azo pigment, condensed azo pigment, and chelate azo pigment; phthalocyanine pigment, perylene and perinone pigment, anthraquinone pigment, quinacridone pigment, dioxazine pigment, thioindigo pigment, isoindolinone pigment, Examples thereof include polycyclic pigments such as quinophthalone pigments; dye lake pigments such as basic dye type lake pigments and acid dye type lake pigments; nitro pigments; nitroso pigments; aniline black daylight fluorescent pigments. Examples of resin-dispersed pigments other than these include C.I. I. Pigment Black 1, 6 and 7; C.I. I. Pigment Yellow 1, 2, 3, 12, 13, 14, 15, 16, 17, 55, 74, 78, 150, 151, 154, 180, 185 and 194; C.I. I. Pigment Orange 31 and 43; C.I. I. Pigment Red 2, 3, 5, 6, 7, 12, 15, 16, 48, 48:1, 53:1, 57, 57:1, 112, 122, 123, 139, 144, 146, 149, 150, 166, 168, 175, 176, 177, 178, 184, 185, 190, 202, 209, 221, 222, 224 and 238; I. Pigment Violet 19 and 196; C.I. I. Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:4, 16, 22 and 60; C.I. I. Pigment Green 7 and 36; and solid solutions of these pigments.

As the resin dispersant, for example, one containing at least one of methacrylic acid and acrylic acid as a monomer can be used, and for example, a commercially available product may be used. The resin dispersant may further contain, for example, styrene and vinyl chloride as a monomer. Examples of the commercially available product include "John Krill (registered trademark) 611" (weight average molecular weight 8100, acid value 53 mgKOH/g) manufactured by Johnson Polymer Co., Ltd., "John Kryl (registered trademark) 60" (weight average molecular weight). 8500, acid value 215 mgKOH/g), "John Kryl (registered trademark) 586", "John Kryl (registered trademark) 687", "John Kryl (registered trademark) 63" and "John Kryl (registered trademark) HPD296"; Big Chemie "Disperbyk 190" and "Disperbyk 191" manufactured by the same company; "Solspers 20000" and "Solspers 27000" manufactured by Zeneca Co., Ltd.; and the like.

The solid content of the resin-dispersed pigment (pigment solid content) in the total amount of the water-based ink is not particularly limited, and can be appropriately determined depending on, for example, a desired optical density or saturation. The pigment solid content is, for example, 0.1% by weight to 20% by weight, 1% by weight to 15% by weight, 2% by weight to 10% by weight. The pigment solid content is the weight of only the pigment and does not include the weight of the resin dispersant. The resin-dispersed pigments may be used alone or in combination of two or more.

The aqueous ink may further contain other pigments and dyes in addition to the resin dispersed pigment.

The water is preferably ion exchanged water or pure water. The blending amount of water in the total amount of the water-based ink may be, for example, the balance of other components.

The water-based ink further contains a vinyl chloride-acrylic copolymer emulsion having a glass transition temperature (Tg) of 50° C. or higher, and a methacrylate ion.

When the Tg of the vinyl chloride-acrylic copolymer emulsion is less than 50°C, a film of the vinyl chloride-acrylic copolymer emulsion is formed in the aqueous ink before ejection, which may cause ejection failure. ..

The vinyl chloride-acrylic copolymer emulsion may be prepared in-house or a commercially available product may be used. The vinyl chloride-acrylic copolymer emulsion may be, for example, a core-shell type emulsion. Examples of the core-shell type emulsion include, but are not limited to, those in which the core portion is a polymer and the shell portion is a surfactant or an emulsifier. The core-shell type emulsion can be prepared by a conventionally known method, for example, emulsion polymerization using a surfactant, emulsion polymerization in the presence of a polymeric emulsifier prepared in advance, and the like. When a high molecular emulsifier is used, the high molecular emulsifier constitutes a shell part which is an outer layer of the emulsion, and a copolymer which is copolymerized in a later step forms a core part which is an inner layer of the emulsion. The core-shell type emulsion may be prepared by a method other than emulsion polymerization such as radical polymerization reaction. Examples of the commercially available products include "Vinibran (registered trademark) 700" (Tg: 70°C, active ingredient concentration: 30% by weight), "Vinibran (registered trademark) 701" (Tg, manufactured by Nisshin Chemical Industry Co., Ltd.). : 73° C., active ingredient concentration: 30% by weight), “Viniblanc (registered trademark) 745” (Tg: 57° C., active ingredient concentration: 30% by weight) and the like.

The methacrylate ion may be added to the aqueous ink as a salt with a cation such as potassium ion.

The solid content blending amount (E) of the vinyl chloride-acrylic copolymer emulsion and the blending amount (A) of the methacrylate ion in the total amount of the aqueous ink satisfy A/E≧0.01. From the viewpoint of improving water resistance, the solid content blending amount (E) and the blending amount (A) preferably satisfy A/E=0.01 to 0.16, and A/E=0.01. It is more preferable to satisfy ~0.1.

The solid content blending amount (E) and the blending amount (A) may be appropriately adjusted so as to satisfy A/E≧0.01, and the solid content blending amount (E) is, for example, 0. 1% by weight to 10% by weight, 1% by weight to 8% by weight, 3% by weight to 6% by weight, and the blending amount (A) is, for example, 0.001% by weight to 0.1% by weight, 0.1% by weight. It is from 01% by weight to 0.08% by weight and from 0.03% by weight to 0.06% by weight.

Since the water-based ink contains a vinyl chloride-acrylic copolymer emulsion having a Tg of 50° C. or higher and a predetermined amount of methacrylate ions, it can be fixed on coated paper at a lower temperature and in a shorter time. is there. The mechanism for improving the fixability on the coated paper is estimated as follows, for example. That is, by adding methacrylate ions to the water-based ink, the methacrylate ions approach the acrylic part, which is the hydrophilic part of the vinyl chloride-acrylic copolymer emulsion, and as a result, the dispersion of the emulsion is impaired. It is considered that the stability became stable, and the fixing to the coated paper became possible by drying at a lower temperature for a shorter time. However, this mechanism is only an estimation, and the present invention is not limited to this. The temperature at the time of drying will be described in the inkjet recording method of the invention described later.

The aqueous ink may further contain propylene glycol (PG). The PG can function, for example, as a wetting agent that prevents the aqueous ink from drying at the nozzle tip portion of the inkjet head. It is preferable that the blending amount (P) of PG in the total amount of the aqueous ink and the blending amount (E) of the solid content of the vinyl chloride-acrylic copolymer emulsion satisfy P/E=2 to 7, and P/E=2 to 7. It is more preferable to satisfy E=2 to 3. When P/E=2 to 7, it is possible to obtain a water-based ink that is more excellent in water resistance, and it is possible to obtain a water-based ink that is extremely excellent in water resistance and fixability on coated paper. The blending amount (P) is, for example, 5% by weight to 50% by weight, 10% by weight to 35% by weight, and 15% by weight to 30% by weight.

The aqueous ink may further contain a wetting agent other than PG. The wetting agent other than PG is not particularly limited, and examples thereof include lower alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, and tert-butyl alcohol; dimethylformamide. , Amides such as dimethylacetamide; ketones such as acetone; keto alcohols such as diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyethers such as polyalkylene glycols; alkylene glycols other than PG, glycerin, trimethylolpropane, trimethylolethane And the like; 2-pyrrolidone; N-methyl-2-pyrrolidone; 1,3-dimethyl-2-imidazolidinone; and the like. Examples of the polyalkylene glycol include polyethylene glycol and polypropylene glycol. Examples of the alkylene glycol other than PG include ethylene glycol, butylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, thiodiglycol, and hexylene glycol. These wetting agents other than PG may be used alone or in combination of two or more. Of these, polyhydric alcohols such as alkylene glycol other than PG and glycerin are preferable.

The blending amount of the wetting agent other than PG in the total amount of the aqueous ink is, for example, 0% by weight to 95% by weight, 5% by weight to 80% by weight, and 5% by weight to 50% by weight.

The water-based ink may further include a penetrant. The penetrant adjusts the drying speed on the recording medium, for example.

Examples of the penetrant include glycol ether. Examples of the glycol ether include ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol-n-propyl ether, diethylene glycol-n-butyl ether, diethylene glycol- n-hexyl ether, triethylene glycol methyl ether, triethylene glycol ethyl ether, triethylene glycol-n-propyl ether, triethylene glycol-n-butyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol-n-propyl Ether, propylene glycol-n-butyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol-n-propyl ether, dipropylene glycol-n-butyl ether, tripropylene glycol methyl ether, tripropylene glycol ethyl ether, Examples include tripropylene glycol-n-propyl ether and tripropylene glycol-n-butyl ether. The penetrant may be used alone or in combination of two or more.

The blending amount of the penetrant in the total amount of the water-based ink is, for example, 0% by weight to 20% by weight, 0% by weight to 15% by weight, and 1% by weight to 6% by weight.

The water-based ink may further include a conventionally known additive, if necessary. Examples of the additive include a surfactant, a pH adjusting agent, a viscosity adjusting agent, a surface tension adjusting agent, and an antifungal agent. Examples of the viscosity modifier include polyvinyl alcohol and cellulose.

The water-based ink includes, for example, a conventionally known method in which the resin-dispersed pigment, the water, the vinyl chloride-acrylic copolymer emulsion, the methacrylate ion, and optionally other additive components are added. It can be prepared by uniformly mixing with, and removing insoluble matter with a filter or the like.

Next, the inkjet recording apparatus and inkjet recording method of the present invention will be described.

An inkjet recording apparatus of the present invention is an inkjet recording apparatus that includes an ink containing section and an ink ejecting unit, and ejects the ink contained in the ink containing section by the ink ejecting section. It is characterized in that it includes a drying means for heating and drying, and that the aqueous ink for inkjet recording of the present invention is stored in the ink storage portion.

The inkjet recording method of the present invention uses the recording step of ejecting and recording an aqueous ink on a recording medium by an inkjet method, and a drying means for heating and drying a recording portion of the recording medium to form the aqueous ink on the recording medium. A fixing step for fixing, wherein the aqueous ink for inkjet recording of the present invention is used as the aqueous ink in the recording step, and the heating temperature in the fixing step is Tg of the vinyl chloride-acrylic copolymer emulsion. The temperature is 0.2 to 4 times that of the above.

The inkjet recording method of the present invention can be implemented using, for example, the inkjet recording apparatus of the present invention. The recording includes printing, printing, printing and the like.

The schematic diagram of FIG. 1 shows the configuration of an example of an inkjet recording apparatus of the present invention. As shown in FIG. 1, the inkjet recording apparatus 100 includes a paper feed tray 101, a transport mechanism (not shown) such as rollers, recording mechanisms 102A and 102B, a platen 103, a drying unit 104, a paper discharge tray 105, and An ink container (not shown) such as an ink cartridge or an ink tank is provided. The paper feed tray 101 can support a plurality of stacked recording media (for example, coated paper) P.

A conveyance path (not shown) is formed inside the inkjet recording apparatus 100 by a guide member. The recording paper P is conveyed from the paper feed tray 101 toward the paper ejection tray 105 by the conveyance mechanism and the conveyance path, as indicated by a dashed arrow in FIG.

The recording mechanism includes a carriage 102A and an inkjet head (ink ejecting means) 102B. The carriage 102A is supported by two guide rails (not shown) extending perpendicularly to the conveyance direction of the recording paper P. The two guide rails are supported by a casing (not shown) of the inkjet recording apparatus 100. The carriage 102B is connected to a known belt mechanism (not shown) provided on the two guide rails. This belt mechanism is driven by a carriage motor (not shown). The carriage 102A connected to the belt mechanism reciprocates in the direction perpendicular to the conveyance direction of the recording paper P by the drive of the carriage motor.

Further, from the carriage 102A, four ink tubes (not shown) that connect the ink storage unit and the inkjet head 102B, and a flexible flat cable that electrically connects the control board (not shown) and the inkjet head 102B. And (not shown) are extended. The four ink tubes supply the inkjet head 102B with the four color water-based inks of yellow, magenta, cyan and black contained in the ink container. At least one of the four color aqueous inks is the inkjet recording aqueous ink of the present invention. The flexible flat cable transmits a control signal output from the control board to the inkjet head 102B.

The inkjet head 102B is mounted on the carriage 102A as shown in FIG. A plurality of nozzles 102C are formed on the lower surface of the inkjet head 102B. The tips of the plurality of nozzles 102C are exposed from the lower surfaces of the carriage 102A and the inkjet head 102B. The inkjet head 102B has an actuator (not shown) for applying a force for ejecting the water-based ink supplied to the inkjet head 102B from the ink containing portion via the ink tube. The actuator may be of any type such as a piezoelectric element type, a thermal ink type, and an electrostatic suction type. In the process in which the carriage 102A reciprocates in the direction perpendicular to the conveyance direction of the recording paper P, the inkjet head 102B ejects aqueous ink as minute ink droplets from the plurality of nozzles 102C. As a result, the image is recorded on the recording paper P. The platen 103 is arranged so as to face the recording mechanism, and supports the recording paper P conveyed from the paper feed tray 101.

The drying unit 104 heat-drys the recording portion of the recording paper P. The temperature during this drying is 0.2 to 4 times the Tg of the vinyl chloride-acrylic copolymer emulsion. The temperature may be, for example, 0.2 times to 2 times the Tg of the vinyl chloride-acrylic copolymer emulsion, or 0.2 times to 1 time the Tg of the vinyl chloride-acrylic copolymer emulsion. The temperature can be appropriately adjusted by changing the setting of the drying means 104, and specifically, for example, 20°C to 200°C, 50°C to 100°C. The drying time can also be adjusted as appropriate by changing the setting of the drying means 104, and is, for example, more than 0 seconds and 300 seconds or less, 0.1 seconds to 60 seconds, and 30 seconds to 60 seconds. The water-based ink of the present invention can be fixed on the coated paper at a lower temperature and in a shorter time as compared with the conventional water-based ink that requires heating and drying at high temperature for a long time. The drying means 104 may be any one capable of heating and drying the recording portion. Examples of the drying means 104 include commercially available dryers, ovens, belt conveyor ovens, irons, hot press machines, and the like, and the recording is performed without contacting the recording portion of the recording paper P such as the dryer, the oven, or the belt conveyor oven. A non-contact drying means for heating and drying the portion is preferred.

The recording paper P after recording and drying is conveyed to the paper discharge tray 105.

Next, examples of the present invention will be described together with comparative examples. The present invention is not limited or restricted by the following examples and comparative examples.

[Preparation of Pigment Dispersions A and B]
20% by weight of pigment (carbon black), 7% by weight of sodium hydroxide neutralized product of styrene-acrylic acid copolymer (acid value 175 mgKOH/g, molecular weight 10000), pure water was added to 100% by weight, and the mixture was stirred. Mix to obtain a mixture. This mixture was put in a wet sand mill filled with 0.3 mm diameter zirconia beads, and dispersed for 6 hours. Thereafter, the zirconia beads were removed with a separator, and filtered with a cellulose acetate filter having a pore size of 3.0 μm to obtain a pigment dispersion liquid A. Further, instead of 7% by weight of the neutralized sodium hydroxide of the styrene-acrylic acid copolymer, 9% by weight of a neutralized sodium hydroxide of the styrene-methacrylic acid copolymer (acid value 175 mgKOH/g, molecular weight 10000). Pigment Dispersion Liquid B was obtained in the same manner as in Preparation of Pigment Dispersion Liquid A, except that (1) was used. The styrene-acrylic acid copolymer and the styrene-methacrylic acid copolymer are water-soluble polymers generally used as a dispersant for pigments.

[Examples 1 to 18 and Comparative Examples 1 to 8]
Components in the ink composition (Tables 1 and 2) except for Pigment Dispersion Liquids A and B or CAB-O-JET (registered trademark) 300 were uniformly mixed to obtain an ink solvent. Next, the ink solvent was added to the pigment dispersions A and B or CAB-O-JET (registered trademark) 300 dispersed in water, and the mixture was uniformly mixed. Then, the obtained mixture was filtered through a cellulose acetate type membrane filter (pore size 3.00 μm) manufactured by Toyo Roshi Kaisha, Ltd. to give Examples 1 to 18 and Comparative Examples 1 to 8 shown in Table 1 and Table 2. A water-based ink for inkjet recording was obtained.

With respect to the water-based inks of Examples 1 to 18 and Comparative Examples 1 to 8, (a) evaluation of fixability on coated paper and (b) water resistance evaluation were carried out by the following methods.

(A) Evaluation of Fixability to Coated Paper Using a bar coater, the coated paper (“OK topcoat+” manufactured by Oji Paper Co., Ltd.) was coated with a coating thickness of 3 μm in Examples and Comparative Examples. The water-based ink of was applied to prepare a coated sample. Next, the coated sample was dried at 60° C. for 30 seconds. Then, the surface of the coated sample was rubbed with a cotton swab from the coated portion of the water-based ink to the non-coated portion. The degree of rubbing and contamination of each of the coated part and the non-coated part was visually confirmed and evaluated according to the following evaluation criteria.

Evaluation of Fixability to Coated Paper Evaluation Criteria AA: There was no rubbing on the coated part and no stain on the non-coated part.
A: 15% of the part rubbed on the coated part had a scratch mark, but the non-coated part was not stained.
B: 30% of the rubbed portion had a trace of rubbing, but the non-coated portion had no stain.
C: There were traces of rubbing on the entire portion where the coated portion was rubbed, and there was stain on the non-coated portion.

(B) Water resistance evaluation (a) The surface of the dried coated sample in the evaluation of the fixability on coated paper was rubbed with a cotton swab moistened with water from the coated portion of the aqueous ink toward the non-coated portion. This operation was repeated until the white background color of the coated paper became visible in the coating section, and the number of times was evaluated according to the following evaluation criteria.

Water Resistance Evaluation Evaluation Criteria AA: When rubbed 5 times or more, there was peeling in the coated part, and the ground color white of the coated paper was visible.
A: When the surface was rubbed 2 to 4 times, the coated part was peeled off, and the background color of the coated paper was white.
B: When rubbing once, there was peeling in the coated part, and the ground color white of the coated paper was visible.

Ink compositions and evaluation results of Examples 1 to 18 and Comparative Examples 1 to 8 are shown in Tables 1 and 2.

As shown in Table 1, in Examples 1 to 18, the evaluation results of the fixability on coated paper were good. In particular, in Examples 1 to 4 in which A/E=0.01 to 0.1, evaluation of water resistance was made more than in Examples 5 to 7 under the same conditions except that A/E>0.1. The results were excellent. In particular, in Examples 9 to 12 in which P/E=2 to 7, the evaluation results of water resistance were superior to those in Example 8 under the same conditions except that P/E=1. In Examples 9 and 10 in which P/E=2 to 3, the evaluation results of water resistance and fixability on coated paper were extremely excellent. Furthermore, in particular, in Examples 14 to 16 in which P/E=2 to 4, the evaluation result of water resistance is superior to that in Example 13 under the same conditions except that P/E=1. In Examples 14 and 15 in which P/E=2 to 3, the evaluation results of water resistance and fixability on coated paper were extremely excellent. On the other hand, as shown in Table 2, Comparative Example 1 in which no methacrylate ion was used, and Comparative Examples 2 to 2 in which an acrylate ion, a benzoate ion, a fumarate ion or a succinate ion was used instead of the methacrylate ion In No. 5, the evaluation result of fixability on coated paper was poor. Also, in Comparative Example 6 using a vinyl chloride-acrylic copolymer emulsion having a Tg of less than 50° C., the evaluation result of the fixability on coated paper was poor. Also, in Comparative Example 7 using only the self-dispersion pigment without using the resin-dispersion pigment, the evaluation result of the fixability on coated paper was poor. Further, also in Comparative Example 8 in which A/E<0.01, the evaluation result of the fixability on coated paper was poor.

As described above, the water-based ink of the present invention can be fixed on coated paper by drying at a lower temperature for a shorter time. The use of the water-based ink of the present invention is not limited to inkjet recording on coated paper, but is widely applicable to inkjet recording on various recording media such as plain paper, glossy paper and matte paper.

100 inkjet recording apparatus 101 paper feed tray 102A carriage 102B inkjet head (ink ejection means)
102C Nozzle 103 Platen 104 Drying means 105 Paper ejection tray

Claims (6)

A water-based ink jet recording ink containing a colorant and water,
The colorant includes a resin dispersed pigment,
further,
A vinyl chloride-acrylic copolymer emulsion having a glass transition temperature of 50° C. or higher;
Methacrylate ion,
Including
The solid content of the vinyl chloride-acrylic copolymer emulsion (E) and the content of the methacrylate ion (A) in the total amount of the water-based ink satisfy A/E≧0.01. A water-based ink for inkjet recording. The solid content amount (E) of the vinyl chloride-acrylic copolymer emulsion and the compounding amount (A) of the methacrylate ion in the total amount of the aqueous ink are A/E=0.01 to 0.1. The water-based ink for inkjet recording according to claim 1, which is satisfied. Furthermore, including propylene glycol,
The compounding amount (P) of propylene glycol in the total amount of the aqueous ink and the solid compounding amount (E) of the vinyl chloride-acrylic copolymer emulsion satisfy P/E=2 to 7. The water-based ink for inkjet recording described. The propylene glycol content (P) in the total amount of the water-based ink and the solid content content (E) of the vinyl chloride-acrylic copolymer emulsion satisfy P/E=2 to 3. Water-based ink for inkjet recording. A recording step of recording a recording medium by ejecting a water-based ink by an inkjet method,
A fixing step of fixing the water-based ink on the recording medium by using a drying means for heating the recording portion of the recording medium;
Including
In the recording step, the aqueous ink for inkjet recording according to any one of claims 1 to 4 is used as the aqueous ink.
The inkjet recording method, wherein the heating temperature in the fixing step is 0.2 to 4 times the glass transition temperature of the vinyl chloride-acrylic copolymer emulsion. The inkjet recording method according to claim 5, wherein the recording medium is coated paper.

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