JP2017165883A - Inkjet ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide ink which is aqueous inkjet ink containing resin fine particles and has all of good quick drying property, fixability and image quality even in comparatively low temperature drying.SOLUTION: There is provided inkjet ink containing water (A), a pigment (B), a water-soluble organic solvent component (C), resin fine particles (D) and a surfactant (E), where a content of the water-soluble organic solvent component (C) in the ink is 10-40 mass%, the ink contains 8-33 mass% of 3-methoxy-1-butanol as the water-soluble organic solvent component (C) in the ink, the water-soluble organic solvent component (C) contains 70 mass% or more of the water-soluble organic solvent having a boiling point of 200°C or lower in the component (C), and the total water-soluble organic solvent contained in the water-soluble organic solvent component (C) has a boiling point of 220°C or lower.SELECTED DRAWING: None

Description

  The present invention relates to an inkjet ink, and more particularly, to an aqueous inkjet ink containing resin fine particles.

  Ink jet printers employing the ink jet recording method are widely used as output devices in homes and offices because they have advantages such as easy operation, low noise, and easy color printing. In recent years, inkjet printers are also used in industrial applications such as displays, posters, and bulletin boards.

  The ink jet recording method is a recording method in which characters and images are obtained by ejecting ink droplets directly from a very fine nozzle and attaching them to a medium. In industrial applications, non-absorbable substrates such as plastic substrates are often used as media. As the plastic substrate, a polyvinyl chloride (PVC) substrate is used, but in recent years, a polyethylene terephthalate (PET) substrate is also used from the viewpoint of mechanical strength, transparency, workability, and the like.

  For printing (image formation) on a PVC substrate, an eco solvent ink jet ink containing a glycol ether solvent and a resin dissolving solvent is suitable. This is because the eco-solvent inkjet ink dissolves the surface of the PVC base material, and exhibits excellent fixability by coating the surface of the PVC base material with the pigment and the fixing resin. However, the eco-solvent inkjet ink does not dissolve the surface of the PET substrate, and the PET substrate usually does not have an ink receiving layer, and therefore is not suitable for printing on the PET substrate. Accordingly, aqueous inkjet inks containing resin fine particles as a binder component have been developed as inkjet inks suitable for printing on non-absorbent substrates other than PVC substrates (see, for example, Patent Documents 1 to 3).

JP 2014-159533 A JP 2014-167084 A JP2015-116691A

  Since the water-based inkjet ink containing resin fine particles as described above contains water, its drying property is important. When using a conventional water-based inkjet ink, it is usual to raise the substrate temperature before and after printing in order to promote drying immediately after printing. If the media to be printed is heat-resistant media, there will be no problem even if it is heated to a high temperature. However, in the case of media having a base material such as a label and an adhesive layer, the adhesive layer softens during heating. Deviation may occur between the material and the adhesive layer. Therefore, in a printer having a print and cut function, the medium cannot be heated to a high temperature before and after drying. On the other hand, in the case of drying at a low temperature, the drying rate is lowered, resulting in a decrease in productivity. In addition, under low-temperature drying conditions, a solvent tends to remain in the ink coating film, resulting in deterioration of ink fixability and image quality. For this reason, it is desired to develop a water-based inkjet ink that is excellent in quick drying, fixing properties, and image quality even at a relatively low temperature.

  The present invention has been made in view of the above points, and an object of the present invention is an aqueous inkjet ink containing resin fine particles, in which quick drying, fixability, and image quality are all good even at relatively low temperature drying. To provide ink.

  The inkjet ink of the present invention contains water (A), a pigment (B), a water-soluble organic solvent component (C), resin fine particles (D), and a surfactant (E). The content of the water-soluble organic solvent component (C) in the ink is 10 to 40% by mass. The ink contains 8-33 mass% of 3-methoxy-1-butanol in the ink as the water-soluble organic solvent component (C). The said water-soluble organic solvent component (C) contains 70 mass% or more of the water-soluble organic solvent whose boiling point is 200 degrees C or less in the said component (C). The total water-soluble organic solvent contained in the water-soluble organic solvent component (C) has a boiling point of 220 ° C. or lower.

  The inkjet ink of the present invention may further contain 2-butanol (F), and the content thereof is preferably 5% by mass or less in the ink.

  In the present invention, the content of the resin fine particles (D) in the ink is preferably 3 to 15% by mass in the ink as a solid content (solid content concentration).

  In the present invention, it is preferable that at least the surface layer portion of the resin fine particles (D) contains a urethane resin.

  In the present invention, the pigment (B) is preferably a self-dispersing pigment.

  The present invention also includes an ink jet recording process comprising the steps of ejecting the above ink jet ink onto a medium having a non-absorbent substrate, and drying the ink jet ink ejected onto the medium to form an ink coating film. Is the method.

  In the method of the present invention, the non-absorbent substrate is preferably a polyethylene terephthalate substrate.

  In the method of this invention, it is preferable that the said medium has the said non-absorbent base material and an adhesive layer.

  In a preferred embodiment of the method of the present invention, the method further includes a step of cutting the media after the step of forming the ink coating film. At this time, in the method of the present invention, it is advantageous that each step is performed using an ink jet recording apparatus having a print and cut function.

  According to the present invention, there is provided an aqueous inkjet ink containing resin fine particles that is excellent in quick drying properties, fixing properties, and image quality even at a relatively low temperature.

  The inkjet ink of the present invention contains water (A), a pigment (B), a water-soluble organic solvent component (C), resin fine particles (D), and a surfactant (E). The content of the water-soluble organic solvent component (C) in the ink (relative to the total mass of the ink) is 10 to 40% by mass. The ink contains 8-33 mass% of 3-methoxy-1-butanol in the ink as the water-soluble organic solvent component (C). The said water-soluble organic solvent component (C) contains 70 mass% or more of the water-soluble organic solvent whose boiling point is 200 degrees C or less in the said component (C). The total water-soluble organic solvent contained in the water-soluble organic solvent component (C) has a boiling point of 220 ° C. or lower.

[Water (A)]
The inkjet ink of the present invention contains water (A) and is therefore an aqueous inkjet ink. By containing water (A), the ink-jet ink of the present invention has an advantage that the environmental load is small. The water (A) used in the present invention is not particularly limited, but ion-exchanged water, ultrafiltered water, reverse osmosis water, distilled water, or ultrapure water is preferable from the viewpoint of preventing impurities from being mixed. Ion exchange water is more preferable.

  The content of water (A) in the inkjet ink of the present invention is preferably 40% by mass or more, more preferably 45% by mass or more, further preferably 47.5% by mass or more, and most preferably 50% by mass or more. On the other hand, 75 mass% or less is preferable, 70 mass% or less is more preferable, 65 mass% or less is further more preferable, and 60 mass% or less is the most preferable.

[Pigment (B)]
The type of the pigment (B) is not particularly limited, and may be an organic pigment or an inorganic pigment.

  Examples of organic pigments include azo pigments (eg, azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments), polycyclic pigments (eg, 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, etc.), nitro pigments, nitroso pigments, aniline black, etc. .

  Examples of inorganic pigments include titanium oxide, zinc white, zinc sulfide, white lead, calcium carbonate, precipitated barium sulfate, white carbon, alumina white, kaolin clay, talc, bentonite, black iron oxide, cadmium red, red rose, molybdenum Red, molybdate orange, chrome vermilion, yellow lead, cadmium yellow, yellow iron oxide, titanium yellow, chromium oxide, viridian, titanium cobalt green, cobalt green, cobalt chrome green, Victoria green, ultramarine, bituminous, cobalt blue, cerulean Examples include blue, cobalt silica blue, cobalt zinc silica blue, manganese violet, and cobalt violet.

  More specifically, examples of the black pigment include carbon blacks (CI pigment black 7) such as furnace black, lamp black, acetylene black and channel black; copper, iron (CI pigment black) 11) and the like; metal oxides such as titanium oxide; and organic pigments such as aniline black (CI pigment black 1).

  Examples of cyan pigments include C.I. I. Pigment blue 1,2,3,15: 1, 15: 3, 15: 4, 15: 6, 16, 21, 22, 60, 64, and the like.

  Examples of magenta pigments include C.I. I. Pigment Red 5, 7, 9, 12, 31, 48, 49, 52, 53, 57, 97, 112, 120, 122, 146, 147, 149, 150, 168, 170, 177, 178, 179, 184 188, 202, 206, 207, 209, 238, 242, 254, 255, 264, 269, 282; I. Pigment violet 19, 23, 29, 30, 32, 36, 37, 38, 40, 50 and the like.

  Examples of yellow pigments include C.I. I. Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 20, 24, 74, 83, 86, 93, 94, 95, 109, 110, 117, 120, 125, 128, 129, 137, 138, 139, 147, 148, 150, 151, 154, 155, 166, 168, 180, 185, 213 and the like.

  Examples of other color pigments include C.I. I. Pigment Green 7, 10, 36; I. Pigment brown 3, 5, 25, 26; C.I. I. Pigment orange 2, 5, 7, 13, 14, 15, 16, 24, 34, 36, 38, 40, 43, 62, 63, 64, 71 and the like.

  In addition, a pigment having a hydrophilic group such as a carboxyl group, a sulfonic acid group, a phosphonic acid group, or a hydroxyl group on the surface (so-called “self-dispersing pigment”) can be used. Examples of the carbon black-based self-dispersing pigment include CAB-O-JET200, 300, 352K, 400 (above, manufactured by Cabot Corporation). Examples of the cyan self-dispersing pigment include CAB-O-JET250C, 450C, 554B (manufactured by Cabot). Examples of the magenta self-dispersing pigment include CAB-O-JET260M, 265M, 465M (above, manufactured by Cabot Corporation). Examples of yellow self-dispersing pigments include CAB-O-JET270Y, 470Y, and 740Y (above, manufactured by Cabot Corporation). As the pigment (B), a self-dispersing pigment is preferable because it can be dispersed in water (A) without using a dispersant.

  The content of the pigment (B) in the inkjet ink of the present invention is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and further preferably 1% by mass or more as the solid content (solid content concentration). preferable. On the other hand, 10 mass% or less is preferable, 7.5 mass% or less is more preferable, and 5 mass% or less is further more preferable.

[Water-soluble organic solvent component (C)]
In the present specification, the “water-soluble organic solvent” constituting the water-soluble organic solvent component (C) refers to an organic solvent having a solubility in water at 20 ° C. of 500 g / L or more. The water-soluble organic solvent is preferably an organic solvent that is uniformly mixed with water at 20 ° C. at an arbitrary ratio.

  The content of the water-soluble organic solvent component (C) in the inkjet ink of the present invention is 10 to 40% by mass. If the content of the water-soluble organic solvent component (C) is less than 10% by mass, the drying property is lowered. In addition, the wettability with respect to the non-absorbent substrate is lowered, and the fixing property and the image quality are lowered. On the other hand, when the content of the water-soluble organic solvent component (C) exceeds 40% by mass, the viscosity of the inkjet ink is excessively increased, and the image quality is deteriorated. The content of the water-soluble organic solvent component (C) is preferably 12.5% by mass or more, and more preferably 15% by mass or more. On the other hand, 37.5 mass% or less is preferable and 35 mass% or less is more preferable.

  The water-soluble organic solvent component (C) contains 3-methoxy-1-butanol. By using 3-methoxy-1-butanol as the water-soluble organic solvent component (C), it is possible to improve the drying property of the inkjet ink at a low temperature and to obtain good quick drying properties. The content of 3-methoxy-1-butanol in the inkjet ink of the present invention is 8 to 33% by mass. When the content is less than 8% by mass, the effect of improving the drying property at a low temperature cannot be obtained sufficiently, and the fixability and the image quality become insufficient. On the other hand, when the content exceeds 33% by mass, an excessive increase in viscosity of the inkjet ink of the present invention is caused, and the image quality becomes insufficient. The content of 3-methoxy-1-butanol is preferably 10% by mass or more, more preferably 12.5% by mass or more, and further preferably 15% by mass or more. On the other hand, 32 mass% or less is preferable, 31 mass% or less is more preferable, and 30 mass% or less is further more preferable.

  The water-soluble organic solvent component (C) can contain a water-soluble organic solvent in addition to 3-methoxy-1-butanol (boiling point: 158 ° C.). However, all the water-soluble organic solvents contained in the water-soluble organic solvent component (C) are water-soluble organic solvents having a boiling point of 220 ° C. or less. When the water-soluble organic solvent component (C) contains a water-soluble organic solvent having a boiling point exceeding 220 ° C., drying does not proceed sufficiently, and fixability and image quality are greatly deteriorated.

  Examples of water-soluble organic solvents having a boiling point of 220 ° C. or lower include ethylene glycol (boiling point: 196 ° C.), propylene glycol (boiling point: 188 ° C.), 1,3-propanediol (boiling point: 213 ° C.), 1,2- Butanediol (boiling point: 194 ° C.), 2,3-butanediol (boiling point: 183 ° C.), 1,3-butanediol (boiling point: 208 ° C.), 2,2-dimethyl-1,3-propanediol (boiling point: 208 ° C), 2-methyl-1,3-propanediol (boiling point: 213 ° C), 1,2-pentanediol (boiling point: 206 ° C), 2,4-pentanediol (boiling point: 201 ° C), 2-methyl Diols such as -2,4-pentanediol (boiling point: 198 ° C); dipropylene glycol monomethyl ether (boiling point: 190 ° C), propylene glycol-n-butyl ether Ter (boiling point: 171 ° C), propylene glycol-t-butyl ether (boiling point: 153 ° C), diethylene glycol methyl ether (boiling point: 194 ° C), ethylene glycol-n-propyl ether (boiling point: 150 ° C), ethylene glycol-n- Examples include butyl ether (boiling point: 171 ° C.), 3-methoxy-3-methyl-1-butanol (boiling point: 174 ° C.), 1-ethoxy-2-propanol (boiling point: 132 ° C.), and the like.

  The content of the water-soluble organic solvent having a boiling point of 200 ° C. or lower in the water-soluble organic solvent component (C) is 70% by mass or more. When the content of the water-soluble organic solvent having a boiling point of 200 ° C. or less is less than 70% by mass, the solvent tends to remain in the ink coating film, and the ink fixability is lowered. The content of the water-soluble organic solvent having a boiling point of 200 ° C. or less in the water-soluble organic solvent component (C) is preferably 75% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more, and 100% by mass. % Is most preferred.

  The water-soluble organic solvent component (C) preferably contains a diol because the water retention of the inkjet ink of the present invention is improved. The content of the diol is preferably 5% by mass or more, and more preferably 10% by mass or more in the water-soluble organic solvent component (C). On the other hand, 50 mass% or less is preferable and 40 mass% or less is more preferable.

[Resin fine particles (D)]
The resin fine particles (D) are a binder component that enhances the fixability to the non-absorbent substrate and the coating film resistance.

  As the resin fine particles (D), known ones that can be used for water-based inkjet inks can be used without particular limitation. Examples of the resin constituting the resin fine particles (D) include urethane resin, polyester resin, acrylic resin, vinyl acetate resin, polyethylene resin, polypropylene resin, fluoroolefin resin, butadiene resin, styrene resin, styrene-butadiene resin, styrene- An acrylic resin, a vinyl chloride resin, an acrylic-silicone resin, etc. are mentioned.

  Moreover, the resin fine particles (D) do not need to be constituted by one kind of resin, and may be constituted by two or more kinds of resins. For example, different types of monomers are emulsified in core-shell type resin particles with different resin compositions in the core and shell and acrylic particles (seed particles) prepared in advance to control the particle size. Fine particles obtained by polymerization can be used. Furthermore, hybrid resin fine particles obtained by chemically combining resin fine particles composed of different resins, such as fine particles made of acrylic resin and fine particles made of urethane resin, can be used.

  Since the fixing property and the ink stability are particularly excellent, the resin fine particles (D) preferably include an acrylic resin or a urethane resin at least in the surface layer portion, and more preferably include a urethane resin in at least the surface layer portion.

  The volume average particle diameter of the resin fine particles (D) is not particularly limited, but is preferably 10 to 1000 nm, more preferably 10 to 200 nm, and further preferably 10 to 50 nm. The volume average particle diameter can be obtained using, for example, a particle size distribution measuring apparatus.

  The content of the resin fine particles (D) in the inkjet ink of the present invention is preferably 3% by mass or more, and more preferably 5% by mass or more as the solid content (solid content concentration). On the other hand, 15 mass% or less is preferable and 12 mass% or less is more preferable.

[Surfactant (E)]
Surfactant (E) is a component that optimizes surface tension and interfacial tension. As the surfactant (E), known surfactants that can be used for water-based inkjet inks can be used without particular limitation, and examples thereof include anionic surfactants, nonionic surfactants, and cationic surfactants. And amphoteric surfactants. Among these, an anionic surfactant or a nonionic surfactant is preferable, and a nonionic surfactant is more preferable.

  Examples of nonionic surfactants include sorbite surfactants, acetylene glycol surfactants, sorbitan surfactants, silicone surfactants, polyoxyethylene alkyl ether surfactants, and the like. Of these, acetylene glycol surfactants are preferred because they are excellent in ability to keep the surface tension and interfacial tension properly, and have almost no foaming property.

  Examples of the acetylene glycol surfactant include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3, 5-dimethyl-1-hexyn-3-ol, 2,4-dimethyl-5-hexyn-3-ol and the like can be mentioned. Moreover, it can also obtain as a commercial item, As an example of a commercial item, Surfinol 104, 104E, 104H, 104A, 104BC, 104DPM, 104PA, 104PG-50, 104S, 420, 440, 465, 485, SE, SE-F, 504, 61, 82, DF37, DF110D, CT111, CT121, CT131, CT136, TG, GA (manufactured by Nissin Chemical Industry Co., Ltd.); Orphine B, Y, P, A, STG, SPC, E1004 E1010, PD-001, PD-002W, PD-003, PD-004, EXP. 4001, EXP. 4036, EXP. 4051, AF-103, AF-104, AK-02, SK-14, AE-3 (above, manufactured by Nissin Chemical Industry Co., Ltd.); acetylenol E00, E13T, E40, E60, E81, E100, E200 (above, river Ken Fine Chemical Co.). Of these, Surfynol 465, Orphine E1010, Acetylenol E100, or E200 is preferable.

  The content of the surfactant (E) in the inkjet ink of the present invention is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and further preferably 1% by mass or more. On the other hand, 10 mass% or less is preferable, 7.5 mass% or less is more preferable, and 5 mass% or less is further more preferable.

[2-Butanol (F)]
When the ink-jet ink of the present invention further contains 2-butanol (F), the ink-jet ink is further improved in dryability at low temperatures.

  When there is too little content of 2-butanol (F), the dryness improvement effect in low temperature is not fully acquired. Therefore, the content of 2-butanol (F) in the inkjet ink of the present invention is preferably 1% by mass or more, more preferably 2% by mass or more, and further preferably 3% by mass or more. On the other hand, when there is too much content of 2-butanol (F), there exists a possibility of reducing image quality. Therefore, the content of the surfactant (E) in the inkjet ink of the present invention is preferably 8% by mass or less, more preferably 7.5% by mass or less, and further preferably 6% by mass or less.

  In addition to the above-mentioned components, the ink-jet ink of the present invention includes addition of antiseptics, fungicides, thickeners, antifoaming agents, pH adjusters, rust inhibitors, etc., as long as the effects of the present invention are not significantly impaired. An agent may be contained.

  The ink-jet ink of the present invention can be prepared by mixing each component according to a known method. For example, it can be prepared by uniformly mixing water, an emulsion containing a pigment, a water-soluble organic solvent, an emulsion containing resin fine particles, a surfactant, and other components using a known mixing device or stirring device. it can.

  The ink-jet ink of the present invention has good quick-drying properties, fixing properties, and image quality even when dried at a relatively low temperature. The inkjet ink of the present invention is a non-absorbing material such as a PET substrate, a PVC substrate, a surface-treated (corona-treated) polyethylene (PE) substrate, a surface-treated (corona-treated) polypropylene (PP) substrate, and a polystyrene substrate. Can be used for printing (image formation) on paper substrates such as absorbent substrates and art paper, coated paper, cast paper, high-quality paper, synthetic paper, inkjet paper, etc. Especially, printing on non-absorbent substrates Can be suitably used. Especially, it can use suitably for the printing to PET base material. Since the ink-jet ink of the present invention has a high quick-drying property, it is suitable for printing on a non-absorbent substrate (particularly a PET substrate) and a medium (for example, a label) having an adhesive layer. When the ink-jet ink of the present invention is used for such a medium, it is not necessary to dry at a high temperature, so that it is possible to prevent the substrate and the adhesive layer from being displaced due to the adhesive layer being softened by heat. it can. Therefore, in particular, in a printer having a print and cut function, printed matter can be provided with high productivity without heating the medium to a high temperature before and after drying.

  Therefore, from another aspect, the present invention is a step of discharging the above-described ink-jet ink (the ink described as the ink-jet ink of the present invention) onto a medium having a non-absorbent substrate (hereinafter also referred to as “discharge step”), And an ink jet recording method including a step of drying the ink jet ink discharged onto the medium to form an ink coating film (hereinafter also referred to as “coating film forming step”).

  Examples of non-absorbent substrates include PET substrates, PVC substrates, surface treated (corona treated) PE substrates, surface treated (corona treated) PP substrates, polystyrene substrates, and the like. A material is preferred.

  Moreover, the media (for example, a label etc.) which have a non-absorbent base material and an adhesive layer are preferable, and the said media may have a peeling layer further.

  In the discharging step, the ink-jet ink is discharged onto a non-absorbent substrate of media. The inkjet recording method of the present invention may further include a step of heating the medium before the discharging step. At this time, the surface temperature of the medium is typically 30 to 80 ° C., but may be, for example, 50 ° C. or less and a relatively low temperature region in the conventional ink jet recording method.

  In the coating film forming step, the medium may be heated to promote drying. At this time, the surface temperature of the medium is typically 30 to 80 ° C., but may be, for example, 50 ° C. or less and a relatively low temperature region in the conventional ink jet recording method.

  The ink jet recording method of the present invention can be carried out, for example, by using the above ink jet ink in a known ink jet recording apparatus (eg, ink jet printer) capable of printing (image formation) on a non-absorbent substrate. it can.

  The ink jet recording method of the present invention may further include a step of cutting the media (hereinafter also referred to as “cutting step”) after the coating film forming step. In this case, the ink jet recording method of the present invention advantageously uses an ink jet recording apparatus having a print and cut function. Moreover, the inkjet recording method of the present invention including the cutting step is suitable for printing on a medium having a non-absorbent substrate and an adhesive layer. According to this method, since the drying property of the ink-jet ink is excellent, it is not necessary to heat the non-absorbent substrate and the pressure-sensitive adhesive layer to such a high temperature that the yield can be improved.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not restrict | limited to these Examples.

[Preparation of inkjet ink]
Each component described in Tables 1 to 3 was uniformly mixed at a mass ratio shown in each table to obtain inkjet inks of Examples and Comparative Examples. The obtained ink-jet ink was printed on a PET film using an ink-jet printer and evaluated for quick drying, fixing properties, and image quality by the following methods. In printing, the surface temperature of the PET film was heated to 30 to 45 ° C. before printing, and the surface temperature of the PET film was heated to 40 to 50 ° C. after printing. In the evaluation of the quick drying property and the fixing property, a full solid image was formed under the conditions of 22 pl per drop and a resolution of 740 dpi × 740 dpi. In the evaluation of the image quality, white dots of 5 pt were printed while forming a full solid image under the conditions of 22 pl per drop and a resolution of 740 dpi × 740 dpi. The evaluation results are shown in Tables 1-3.

[Quick-drying evaluation]
After printing, when a heating time of 30 seconds passed, the solid image was rubbed with a cotton swab, and the state of the solid image and the cotton swab was observed. From the observation results, quick drying was evaluated according to the following criteria. “◯” and “△” were accepted.
○: Ink does not adhere to the swab and the solid image does not change. Δ: Ink does not adhere to the swab, but the solid image is scratched. ×: Ink adheres to the swab and a solid image can be taken.

[Fixability evaluation]
A crosscut-shaped cut was made in the ink coating film formed after drying. Next, after the cellophane tape was attached to the ink coating film, the cellophane tape was peeled off, and the state of the ink coating film was observed. From the observation results, the fixability was evaluated according to the following criteria. “◯” and “△” were accepted.
○: No peeling occurs on the ink coating film Δ: The ink coating film peels slightly ×: More than half of the ink coating film peels

[Image quality evaluation]
The image quality of the L dot outline characters was visually observed. From the observation results, image quality was evaluated according to the following criteria. “◯” and “△” were accepted.
○: Excellent in the visibility of white characters Δ: The white characters are slightly crushed but are visible X: The white characters are crushed to be difficult to see, or a solid image is cracked

(Numerical values for each component in each table indicate mass percentage.)
CAB-O-JET260M (manufactured by Cabot Corporation): self-dispersing pigment (aqueous emulsion having a solid content of 10% by mass)
CAB-O-JET250C (manufactured by Cabot Corporation): self-dispersing pigment (aqueous emulsion having a solid content of 10% by mass)
E1010 (Nisshin Chemical Industry Co., Ltd.): Acetylene glycol surfactant “Orphine E1010”
HUX-401 (manufactured by ADEKA): water-based urethane resin “Adekabon titer HUX-401” (solid content: 39% by mass)
VINYBRAN 715S (Nissin Chemical Industry Co., Ltd.): Aqueous emulsion of polyvinyl chloride-polyurethane core-shell particles (solid content 25% by mass)
PE1126 (manufactured by Seiko PMC): Acrylic resin aqueous emulsion (solid content: 41.5% by mass)

  From Table 1, it can be seen that the inkjet inks of Examples 1 to 14 within the scope of the present invention exhibit good quick-drying properties, fixing properties, and image quality even at relatively low temperature drying.

  On the other hand, from the result of Comparative Example 1, it can be seen that when the content of 3-methoxy-1-butanol is excessively reduced to increase the content of water, quick drying properties, fixing properties, and image quality are deteriorated. . From the results of Comparative Example 5, when the water-soluble organic solvent is used instead of 3-methoxy-1-butanol and the content of 3-methoxy-1-butanol is excessively reduced, the image quality is poor. I understand. In addition, the results of Comparative Example 2 indicate that the image quality deteriorates when the content of 3-methoxy-1-butanol is excessively large. From the results of Comparative Example 3, it can be seen that when the content of the water-soluble organic solvent having a boiling point of 200 ° C. or less in the water-soluble organic solvent component is less than 70% by mass, the fixability is deteriorated. Further, from the result of Comparative Example 4, it can be seen that when the water-soluble organic solvent component contains a water-soluble organic solvent having a boiling point exceeding 220 ° C., quick-drying property, fixability, and image quality are deteriorated.

  The inkjet ink of the present invention includes a PET substrate, a PVC substrate, a polyethylene (PE) substrate, a polypropylene (PP) substrate, a non-absorbable substrate such as a polystyrene substrate, art paper, coated paper, cast paper, It can be used for printing (image formation) on a paper substrate such as high-quality paper, synthetic paper, and inkjet paper, and can be suitably used for printing on a non-absorbent substrate.

Claims (10)

An inkjet ink containing water (A), pigment (B), water-soluble organic solvent component (C), resin fine particles (D), and surfactant (E),
The content of the water-soluble organic solvent component (C) in the ink is 10 to 40% by mass,
The ink contains 8-33 mass% of 3-methoxy-1-butanol in the ink as the water-soluble organic solvent component (C),
The water-soluble organic solvent component (C) contains 70% by mass or more of a water-soluble organic solvent having a boiling point of 200 ° C. or less in the component (C),
The total water-soluble organic solvent contained in the water-soluble organic solvent component (C) has a boiling point of 220 ° C. or less.
Inkjet ink.   The inkjet ink according to claim 1, further comprising 2-butanol (F) in an amount of 5% by mass or less in the ink.   The inkjet ink according to claim 1 or 2, wherein a content of the resin fine particles (D) in the ink is 3 to 15% by mass in the ink as a solid content.   The inkjet ink according to any one of claims 1 to 3, wherein at least a surface layer portion of the resin fine particles (D) contains a urethane resin.   The inkjet ink according to any one of claims 1 to 4, wherein the pigment (B) is a self-dispersing pigment.   A step of discharging the inkjet ink according to any one of claims 1 to 5 to a medium having a non-absorbent substrate, and drying the inkjet ink discharged to the medium to form an ink coating film. An ink jet recording method comprising a step.   The inkjet recording method according to claim 6, wherein the non-absorbing substrate is a polyethylene terephthalate substrate.   The inkjet recording method according to claim 6 or 7, wherein the medium has the non-absorbable substrate and an adhesive layer.   The inkjet recording method according to any one of claims 6 to 8, further comprising a step of cutting the medium after the step of forming the ink coating film. The inkjet recording method according to claim 9, wherein each step is performed using an inkjet recording apparatus having a print and cut function.