Recording method

Abstract

The present application provides a recording method with good productivity of a recording material and good image quality of the obtained recording material. A recording method includes an attaching step of attaching an ink composition to a recording medium, where the recording medium is a low-absorbing recording medium or a non-absorbing recording medium. The attaching step is performed by scanning the ink composition ejected from an inkjet head and attached to the recording medium while moving the relative position of the inkjet head and the recording medium. The number of times of scanning the same area of the recording medium is seven or less. The ink composition is an aqueous ink containing a coloring material and a silicone-based surfactant A, and the silicone-based surfactant A has a maximum peak in the range of 3000 to 20000 in terms of molecular weight distribution in gel permeation chromatography and within the range where the molecular weight is 300 or more.

Description

Technical Field

[0001] The present invention relates to a recording method. Background Art

[0002] The inkjet method can form high-quality images on a recording medium, and thus various technical developments have been carried out thereon. For example, not only the development of a recording apparatus using the inkjet method, but also the development of a composition used in the apparatus has been popular. Moreover, extensive research has been conducted on combinations of a recording apparatus, an ink composition, a treatment liquid, a recording medium, etc., or a recording method using these.

[0003] In the case of recording an image on a low-absorbing or non-absorbing recording medium by the inkjet method, ink dots of the ink attached to the recording medium sometimes temporarily remain on the recording medium without being absorbed. In such a case, the ink dots of the ink aggregate with each other, and it is easy to cause uneven coagulation (bleeding unevenness). Therefore, for example, Patent Document 1 discloses a recording method in which, by increasing the number of passes in inkjet recording, the ink dots of the ink are attached to the recording medium in a manner distributed over multiple passes, and the ink is dried during the attachment, thereby reducing the aggregation of the dots.

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019-162840

[0005] However, in the case of increasing the number of passes, even if the image quality tends to improve, the speed of recording an image decreases, and the productivity of the recorded object becomes insufficient. Therefore, a recording method is required that has good productivity of the recorded object and makes the image quality of the obtained recorded object good. Summary of the Invention

[0006] One aspect of the recording method according to the present invention is a recording method including an attachment step of attaching an ink composition to a recording medium,

[0007] wherein the recording medium is a low-absorbing recording medium or a non-absorbing recording medium,

[0008] the attachment step is performed by scanning while moving the relative position of an inkjet head and the recording medium and ejecting the ink composition from the inkjet head to attach it to the recording medium,

[0009] the number of times of scanning the same area of the recording medium is seven or less,

[0010] the ink composition is an aqueous ink containing a coloring material and an organosilicon surfactant A.

[0011] The organosilicon surfactant A has a maximum peak in the molecular weight range of 300 or more in the molecular weight distribution by gel permeation chromatography in the range of 3,000 to 20,000. Description of the Drawings

[0012] Figure 1 It is a schematic diagram of an example of an inkjet recording apparatus.

[0013] Figure 2 It is a schematic diagram of the periphery of the carriage of an example of an inkjet recording apparatus.

[0014] Description of Reference Numerals

[0015] 1: Inkjet recording apparatus; 2: Inkjet head; 3: IR heater; 4: Platen heater; 5: Heater; 6: Cooling fan; 7: Preheater; 8: Ventilation fan; 9: Carriage; 11: Platen; 12: Ink cartridge; 13: Carriage moving mechanism; 14: Conveying unit; CONT: Control unit; MS: Main scanning direction; SS: Sub-scanning direction; M: Recording medium. Detailed Description of the Invention

[0016] Embodiments of the present invention will be described below. The embodiments described below are examples for explaining the present invention. The present invention is not limited to any of the following embodiments, and also includes various modified forms implemented within the scope of not changing the gist of the present invention. In addition, all the configurations described below are not necessarily essential configurations of the present invention.

[0017] In this specification, “(meth)acrylic acid” means acrylic acid or methacrylic acid, and “(meth)acrylate” means acrylate or methacrylate.

[0018] 1. Recording Method

[0019] The recording method of the present embodiment includes an attachment step of attaching an ink composition to a recording medium.

[0020] 1.1. Attachment Step

[0021] The attachment step is performed by scanning while moving the relative position of the inkjet head and the recording medium and ejecting the ink composition from the inkjet head to attach it to the recording medium. The number of times of scanning the same area of the recording medium is seven times or less. Hereinafter, the recording medium, the ink composition, and the inkjet recording apparatus (inkjet head) will be described, and then the scanning will be described.

[0022] 1.1.1. Recording Medium

[0023] The recording medium on which an image is formed by the recording method according to the present embodiment is a liquid low-absorbency recording medium such as printing paper, a liquid non-absorbency recording medium such as metal, glass, film, and polymer, and the like.

[0024] The excellent effects of the recording method of this embodiment are particularly remarkable when recording an image on a liquid low-absorbing or liquid non-absorbing recording medium. That is, according to the recording method of this embodiment, even for a low-absorbing recording medium or a non-absorbing recording medium that is relatively likely to cause coagulation unevenness, a high-quality image can be formed.

[0025] A liquid low-absorbing or liquid non-absorbing recording medium refers to a recording medium having the property of not absorbing liquid at all or hardly absorbing liquid. Quantifying it, a liquid non-absorbing or liquid low-absorbing recording medium means: "In the Bristow method, the water absorption amount from the start of contact until 30 msec 1 / 2 is 10 mL / m 2 or less of the recording medium". This Bristow method is a method widely used for measuring the liquid absorption amount in a short time, and this method is also adopted by the Japan Tappi Association. The details of the test method are described in Standard No. 51, "Paper and Board - Liquid Absorbency Test Method - Bristow Method" of "Japan Tappi Pulp Test Method 2000 Edition". In contrast, a liquid-absorbing recording medium refers to a recording medium that does not belong to a liquid non-absorbing and liquid low-absorbing recording medium. In addition, in this specification, liquid low-absorbency and liquid non-absorbency are sometimes simply referred to as low-absorbency and non-absorbency.

[0026] As a liquid non-absorbing recording medium, for example, there can be cited plastic films or plates such as polyvinyl chloride, polyethylene, polypropylene, polyethylene terephthalate (PET), metal plates such as iron, silver, copper, aluminum, or metal plates or plastic films made by vapor-depositing these various metals, alloy plates such as stainless steel or brass. In addition, there can be exemplified media obtained by coating plastic on a substrate such as paper, media obtained by bonding a plastic film to a substrate such as paper, plastic films without an absorption layer (receiving layer), etc. As the plastics mentioned here, there can be cited polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene, etc.

[0027] In addition, as a liquid low-absorbing recording medium, there can be cited a recording medium provided with a coating layer (receiving layer) for receiving liquid on the surface. For example, as a medium with paper as the substrate, there can be cited printing paper, and as a medium with a plastic film as the substrate, there can be cited a medium obtained by coating a hydrophilic polymer on the surface of polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene, etc.; a medium obtained by coating particles such as silica and titanium together with an adhesive.

[0028] In addition, the recording medium may also be colorless and transparent, translucent, colored and transparent, colored and opaque, colorless and opaque, etc. Additionally, the recording medium itself may be colored, translucent or transparent.

[0029] 1.1.2. Ink Composition

[0030] The ink composition is an aqueous ink composition, containing a coloring material, a specified silicone surfactant A, and water, and may also contain an organic solvent, resin particles, wax, other surfactants, etc. as needed. In addition, in this specification, "ink composition" is sometimes abbreviated as "ink", etc. Also, in this specification, "aqueous ink" refers to an ink containing water as the main solvent component, and "inkjet ink" refers to an ink that can be ejected from an inkjet head by an inkjet method and used for recording.

[0031] (1) Coloring Material

[0032] The inkjet ink composition used in the recording method according to this embodiment contains a coloring material.

[0033] As the coloring material, either a pigment or a dye can be used, and inorganic pigments, organic pigments, oil-soluble dyes, acid dyes, direct dyes, reactive dyes, basic dyes, disperse dyes, sublimation dyes, etc. containing carbon black and titanium white can be used. The ink composition preferably contains a pigment, and this pigment can also be dispersed by a dispersion resin.

[0034] Pigment

[0035] As the inorganic pigment, carbon blacks (C.I. Pigment Black 7) such as furnace black, lamp black, acetylene black, channel black, etc., iron oxide, titanium oxide, zinc oxide, silicon dioxide, etc. can be used.

[0036] As the organic pigment, quinacridone-based pigments, quinacridonequinone-based pigments, dioxazine-based pigments, phthalocyanine-based pigments, anthrapyrimidine-based pigments, anthrone-based pigments, indanthrone-based pigments, flavanthrone-based pigments, perylene-based pigments, diketopyrrolopyrrole-based pigments, violanthrone-based pigments, quinophthalone-based pigments, anthraquinone-based pigments, thioindigo-based pigments, benzimidazolone-based pigments, isoindolinone-based pigments, azomethine-based pigments or azo-based pigments, etc. can be exemplified.

[0037] Specific examples of the organic pigment used in the ink composition are listed below.

[0038] As the cyan pigment, C.I. Pigment Blue 1, 2, 3, 15:3, 15:4, 15:34, 16, 22, 60, etc.; C.I. Bat Blue 4, 60, etc. can be exemplified, and preferably, a mixture of one or more selected from the group consisting of C.I. Pigment Blue 15:3, 15:4, and 60 can be exemplified.

[0039] As magenta pigments, C.I. Pigment Red 5, 7, 12, 48 (Ca), 48 (Mn), 57 (Ca), 57:1, 112, 122, 123, 168, 184, 202, C.I. Pigment Violet 19, etc. can be cited. Preferably, one or more mixtures selected from the group consisting of C.I. Pigment Red 122, 202 and 209, and C.I. Pigment Violet 19 can be exemplified.

[0040] As yellow pigments, C.I. Pigment Yellow 1, 2, 3, 12, 13, 14C, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 119, 110, 114, 128, 129, 138, 150, 151, 154, 155, 180, 185, etc. can be cited. Preferably, one or more mixtures selected from the group consisting of C.I. Pigment Yellow 74, 109, 110, 128, 138, 150 and 180 can be exemplified.

[0041] Pigments of other colors can also be used. For example, orange pigments, green pigments, etc. can be cited.

[0042] The pigments exemplified above are examples of preferred pigments and are not limited to these. These pigments can be used as one or more mixtures, or can be used in combination with dyes.

[0043] In addition, the pigments can be used after being dispersed with a dispersant selected from water-soluble resins, surfactants, etc., or can be dispersed as self-dispersing pigments by oxidizing or sulfonating the pigment surface with ozone, hypochlorous acid, fuming sulfuric acid, etc. Further, as the surfactant that can be used in the dispersant, it can be other surfactants that can be contained in the ink composition described later.

[0044] As the dye, there is no particular limitation, and examples thereof include acid dyes, basic dyes, direct dyes, reactive dyes, and disperse dyes. Specific examples of the dye include C.I. Acid Yellow 17, 23, 42, 44, 79, 142, C.I. Acid Red 52, 80, 82, 249, 254, 289, C.I. Acid Blue 9, 45, 249, C.I. Acid Black 1, 2, 24, 94, C.I. Food Black 1, 2, C.I. Direct Yellow 1, 12, 24, 33, 50, 55, 58, 86, 132, 142, 144, 173, C.I. Direct Red 1, 4, 9, 80, 81, 132, 225, 227, C.I. Direct Blue 1, 2, 15, 71, 86, 87, 98, 165, 199, 202, C.I. Direct Black 19, 38, 51, 71, 154, 168, 171, 195, C.I. Reactive Red 14, 32, 55, 79, 141, 249, C.I. Reactive Black 3, 4, 35. The above dyes may be used alone or in combination of two or more.

[0045] The content of the coloring material is preferably 0.5% by mass or more and 10% by mass or less, more preferably 1.0% by mass or more and 8.0% by mass or less, further preferably 2.0% by mass or more and 6.0% by mass or less, and even more preferably 2.5% by mass or more and 5.0% by mass or less with respect to the total amount of the ink composition. By setting the content of the coloring material within the above range, the ejection stability of the inkjet method tends to be further improved.

[0046] (2) Surfactant

[0047] The ink composition contains a specified silicone-based surfactant A, and may also contain a silicone-based surfactant B or other surfactants described below as needed.

[0048] (2-1) Silicone-based surfactant A

[0049] In the molecular weight distribution of the silicone-based surfactant A in gel permeation chromatography (GPC), there is a maximum peak in the range of a molecular weight of 300 or more in the range of a molecular weight of 3000 to 20000. By containing such a silicone-based surfactant A, it is easy to increase the viscosity of the ink composition during the process of solvent drying on the recording medium, and the coalescence of multiple ink dots or the mixing between ink dots can be suppressed, so that image unevenness (image quality unevenness) can be suppressed and the visual recognition or optical density of the image can be improved.

[0050] The maximum peak within the range where the molecular weight of the silicone-based surfactant A is 300 or more is at a molecular weight of 3,000 to 20,000, preferably at a molecular weight of 4,000 to 15,000, and more preferably at a molecular weight of 5,000 to 10,000. By having the maximum peak within the range where the molecular weight is 300 or more at a molecular weight of 3,000 or more, the coalescence and mixing of ink dots in the ink composition can be suppressed, and there is a tendency for the visual recognition or optical density of the image to be further improved. In addition, by having the maximum peak within the range where the molecular weight is 300 or more at a molecular weight of 20,000 or less, the ejection stability tends to be further improved.

[0051] The maximum peak within the range where the molecular weight of the silicone-based surfactant A is 300 or more can be determined from the molecular weight distribution chart in GPC obtained by setting the horizontal axis as "logarithm of molecular weight M (LogM)" and the vertical axis as "differential value of concentration fraction (dw / d(LogM))". Here, the "maximum peak" means the largest value among the peaks within the range where the molecular weight is 300 or more. In addition, the "maximum peak within the range where the molecular weight is 300 or more" means ignoring the peaks with a molecular weight less than 300. That is, there may be a maximum peak in the range where the molecular weight is less than 300, but it is the maximum peak in the case where peaks are observed only within the range where the molecular weight is 300 or more.

[0052] Although not particularly limited, for example, the measurement conditions for GPC measurement in the present embodiment can be the conditions described in the examples, and the determination of the molecular weight can be performed using standard polystyrene.

[0053] The silicone-based surfactant A is not particularly limited. For example, polysiloxane compounds such as dimethylsiloxane, methylphenylsiloxane, and diphenylsiloxane can be mentioned. These polysiloxane compounds can also be modified silicone oxides such as those obtained by modifying the groups at the ends or side chains with polyether groups. These silicone-based surfactants A can be used alone or in combination of two or more.

[0054] Among them, as the organosilicon surfactant A, a modified organosiloxane is preferred, and a polyether-modified organosiloxane is more preferred. As such a polyether-modified organosiloxane, a modified organosiloxane having a terminal modified with a polyether group represented by the general formula (1) or a modified organosiloxane having a side chain modified with a polyether group represented by the general formula (3) can be cited. By using such an organosilicon surfactant A, the coalescence and mixing of the ink dots of the ink composition can be further suppressed. As a result, there is a tendency for the concentration of the image of the ink composition to increase and the optical density to further increase. In particular, when the ink composition contains the organosilicon surfactant B described below, excellent effects can be obtained even when the ink dots of the ink composition are more likely to coalesce and mix. In addition, the molecular weight of the organosilicon surfactant A is relatively high, and it is speculated that the coalescence and mixing of the ink dots of the ink composition can be suppressed, but the reason is not limited to this.

[0055]

[0056] (In the general formula (1), R 1 each independently represents an alkylene group having 1 to 6 carbon atoms or a single bond, X 1 each independently represents a polyether group represented by the following general formula (2), and a represents an integer of 10 or more and 80 or less.)

[0057]

[0058] (In the general formula (2), R 2 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an (meth)acrylic acid group, EO represents an ethylene oxide group, PO represents a propylene oxide group, the order of EO and PO is a random order, b represents an integer of 0 or more, c represents an integer of 0 or more, and b + c is 1 or more.)

[0059]

[0060] (In the general formula (3), R 3 each independently represents an alkyl group having 1 to 6 carbon atoms, X 2 each independently represents a polyether group represented by the following general formula (4), and d and e represent integers of 1 or more, and d + e is 2 or more and 50 or less.)

[0061]

[0062] (In the general formula (4), R 4 represents an alkylene group having 1 to 6 carbon atoms or a single bond, R 5represents an alkyl group having 1 to 6 carbon atoms or a hydrogen atom, EO represents an ethyleneoxy group, PO represents a propyleneoxy group, the order of EO and PO is a random order, f represents an integer of 0 or more, g represents an integer of 0 or more, and f + g is 1 or more.)

[0063] As the alkylene group having 1 to 6 carbon atoms represented by R 1 , R 3 and R 4 , there is no particular limitation, and examples thereof include methylene, ethylene, propylene, butylene, pentylene, hexylene and the like. Preferably, R 1 , R 4 is an alkylene group having 1 to 6 carbon atoms.

[0064] As the alkyl group having 1 to 6 carbon atoms represented by R 2 and R 5 , there is no particular limitation, and examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, neopentyl, n-hexyl and the like.

[0065] R 1 , R 4 may be a single bond. A single bond means a direct bond formed by a single bond between the atom on the right side and the atom on the left side of R 1 , R 4 .

[0066] In the general formulas (1) and (2), a is an integer of 10 to 80, preferably an integer of 20 to 70, more preferably an integer of 30 to 60. Further, b is an integer of 0 or more, preferably 1 or more, more preferably 2 to 30, and still more preferably 5 to 20. Further, c is an integer of 0 or more, preferably 0 to 30, more preferably 0 to 20. Further, b + c is an integer of 1 or more, preferably 1 to 60, more preferably 2 to 40, and still more preferably 5 to 20.

[0067] In the general formulas (3) and (4), d and e are each an integer of 1 or more, preferably 5 to 40, more preferably 10 to 20. Further, d + e is an integer of 2 to 50, preferably 5 to 40, more preferably 10 to 30. Further, f is an integer of 0 or more, preferably 1 or more, more preferably 2 to 30, and still more preferably 5 to 20. Further, g is an integer of 0 or more, preferably 0 to 30, more preferably 0 to 20. Further, f + g is an integer of 1 or more, preferably 1 to 60, more preferably 2 to 40, and still more preferably 5 to 20.

[0068] The content of the silicone-based surfactant A is preferably 0.05% by mass or more with respect to the total amount of the ink composition. On the other hand, it is preferably 5% by mass or less. Additionally, it is preferably 0.05% by mass or more and 4% by mass or less, more preferably 0.05% by mass or more and 1.5% by mass or less, still more preferably 0.1% by mass or more and 1.2% by mass or less, even more preferably 0.2% by mass or more and 1.0% by mass or less, and further preferably 0.4% by mass or more and 0.6% by mass or less. Or it is preferably 0.1% by mass or more and 0.3% by mass or less, more preferably 0.1% by mass or more and 0.2% by mass or less. By making the content of the silicone-based surfactant A within the above range, the coalescence and mixing of the ink dots of the ink composition can be further suppressed, and the visual recognition, optical density, or rub resistance of the image tends to be further improved.

[0069] Among the silicone-based surfactants A, the modified silicone oxide modified with a polyether group represented by the general formula (1) is more excellent in terms of the visual recognition of the image or the suppression of coagulation unevenness, and is preferred.

[0070] (2-2) Silicone-based surfactant B

[0071] The ink composition may further contain one or more of the silicone-based surfactants B described below, and preferably contains one or more of the silicone-based surfactants B. Thereby, the density of the image tends to be further increased.

[0072] The silicone-based surfactant B does not have a maximum peak in the range of a molecular weight of 300 or more in the molecular weight distribution of gel permeation chromatography, and the HLB value (Hydrophile-Lipophile Balance) by the Griffin method is 10.5 or less. By containing such a silicone-based surfactant B, the wettability of the ink composition with respect to the recording medium is further improved, and the covering property can be improved. Therefore, the visual recognition or optical density of the image formed by the ink composition can be further improved.

[0073] The silicone-based surfactant B does not have a maximum peak within the range of a molecular weight of 300 or more in the range where the molecular weight is 3000 or more. Specifically, it does not have a peak within the range of a molecular weight of 300 or more, or even if it has a peak within the range of a molecular weight of 300 or more, its maximum peak is less than 3000 in molecular weight. By using the silicone-based surfactant B that satisfies the above molecular weight conditions, the wettability of the ink composition with respect to the recording medium is further improved, the surface of the recording medium can be sufficiently covered with the ink composition, and the visual recognition of the image is further improved. In particular, since the recording medium is a low-absorbing recording medium or a non-absorbing recording medium, there is a tendency for the wettability to be further improved. On the other hand, the abrasion resistance of the image of the silicone-based surfactant B can also be further improved compared to the silicone-based surfactant A.

[0074] In addition, the maximum peak within the range of a molecular weight of 300 or more of the silicone-based surfactant B can be measured by the same method as that of the silicone-based surfactant A.

[0075] In addition, the HLB value of the silicone-based surfactant B is 10.5 or less, preferably 2.0 or more and 10.3 or less, more preferably 3.0 or more and 10.1 or less, and still more preferably 4.0 or more and 10.0 or less. By making the HLB value 10.5 or less, the wettability of the ink composition with respect to the recording medium is further improved, and the visual recognition of the image is further improved. In addition, by making the HLB value 2.0 or more, there is a tendency for the optical density of the obtained image to be further increased and the aggregation unevenness to be further reduced.

[0076] Here, the HLB value is a value representing the degree of affinity of the surfactant for water and oil. By making the HLB value within the above range, the wettability of the ink droplet when dropping on a highly hydrophobic and difficult-to-absorb substrate can be improved. By improving the wettability, the white leakage or bleeding of color mixing on the substrate is suppressed, and thus there is a tendency for the visual recognition of the image to be further improved. In addition, the HLB value in the present embodiment is a value defined and calculated by the Griffin method.

[0077] The silicone-based surfactant B is not particularly limited, and examples thereof include polysiloxane-based compounds such as dimethylsiloxane, methylphenylsiloxane, and diphenylsiloxane. In particular, modified silicone oxides in which the groups at the ends or side chains of polysiloxane-based compounds are modified with polyether groups and the like can be mentioned. These silicone-based surfactants B can be used alone or in combination of two or more.

[0078] As the silicone surfactant B, for example, in the above general formula (1), a is less than the surfactant of the silicone surfactant A contained in the ink composition. In addition, in the above general formula (3), d + e is less than the surfactant of the silicone surfactant A contained in the ink composition. The molecular weight of the silicone surfactant B is smaller than that of the silicone surfactant A contained in the ink composition.

[0079] The silicone surfactant B can be used alone or in combination of two or more. The content of the silicone surfactant B is preferably 0.05% by mass or more with respect to the total amount of the ink composition. On the other hand, it is preferably 5.0% by mass or less. In addition, it is preferably 0.1% by mass or more and 5.0% by mass or less, more preferably 0.3% by mass or more and 3.0% by mass or less, further preferably 0.6% by mass or more and 1.5% by mass or less. Or it is preferably 0.4% by mass or more and 1.0% by mass or less.

[0080] By making the content of the silicone surfactant B within the above range, the visual recognition of the image tends to be further improved. In addition, the silicone surfactant B has a property of being relatively easy to evaporate compared with the silicone surfactant A, so the abrasion resistance of the obtained image tends to be excellent. Therefore, it is more preferable that the content of the silicone surfactant B is more than the content of the silicone surfactant A.

[0081] (2-3) Other surfactants

[0082] The ink composition may also contain other surfactants. There is no particular limitation on other surfactants. For example, examples thereof include alkynediol surfactants, fluorosurfactants, and other silicone surfactants other than the above silicone surfactants A and B. Other surfactants can be used alone or in combination of two or more.

[0083] There is no particular limitation on the alkynediol surfactant. For example, 2,4,7,9-tetramethyl-5-decyn-4,7-diol and alkylene oxide adducts of 2,4,7,9-tetramethyl-5-decyn-4,7-diol, and 2,4-dimethyl-5-decyn-4-ol and alkylene oxide adducts of 2,4-dimethyl-5-decyn-4-ol can be mentioned.

[0084] There is no particular limitation on the fluorosurfactant. For example, perfluoroalkyl sulfonates, perfluoroalkyl carboxylates, perfluoroalkyl phosphates, perfluoroalkyl ethylene oxide adducts, perfluoroalkyl betaines, perfluoroalkyl amine oxide compounds can be mentioned.

[0085] As other silicone-based surfactants, as long as they do not meet the requirements of silicone-based surfactants A and B, there is no particular limitation, and examples thereof include polysiloxane-based compounds, polyether-modified silicone oxides, etc. As other silicone-based surfactants, for example, SAG503A, BYK-348, etc. can be cited.

[0086] The content of other surfactants is preferably 0.1% by mass or more and 5.0% by mass or less, more preferably 0.3% by mass or more and 3.0% by mass or less, and still more preferably 0.6% by mass or more and 1.5% by mass or less, relative to the total amount of the ink composition.

[0087] In addition, the total content of all surfactants (regardless of type) in the ink composition is further preferably 2.0% by mass or less relative to the total amount of the ink composition. In this way, an image with more excellent image quality can be obtained. In addition, it is also preferable that the total content of the silicone-based surfactants in the ink composition is in the above range.

[0088] (3) Water

[0089] The ink composition is an aqueous ink and contains water. The aqueous ink is an ink containing at least water as a main solvent component. The content of water is preferably 40% by mass or more relative to the total amount of the ink composition. In addition, it is preferably 40% by mass or more and 98% by mass or less, more preferably 50% by mass or more and 90% by mass or less. In addition, it is preferably 55% by mass or more and 85% by mass or less, more preferably 60% by mass or more and 80% by mass or less, and still more preferably 65% by mass or more and 75% by mass or less.

[0090] (4) Organic solvent

[0091] The ink composition may also contain an organic solvent. As the organic solvent, for example, alcohols, alkane polyols, alkylene glycol ethers, esters, amides, sulfur-containing solvents, cyclic ethers, etc. can be cited, but are not limited to these. The alkane polyols may also include alkane diols.

[0092] As the alcohols, for example, compounds in which one hydrogen atom of an alkane is replaced by a hydroxyl group can be cited. As the alkane, an alkane having 10 or less carbon atoms is preferred, more preferably an alkane having 6 or less carbon atoms, and still more preferably an alkane having 3 or less carbon atoms. The alkane has 1 or more carbon atoms, preferably 2 or more carbon atoms. The alkane may be linear or branched. As the alcohols, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, tert-butanol, isobutanol, n-pentanol, 2-pentanol, 3-pentanol, and tert-pentanol can be cited.

[0093] Alkane diols refer to, for example, compounds in which an alkane is substituted by two hydroxyl groups. Examples of alkane diols include ethylene glycol (alias: ethane-1,2-diol), propylene glycol (alias: propane-1,2-diol), 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol, 1,3-propanediol, 1,3-butanediol (alias: 1,3-butane diol), 1,4-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, 2,4-pentanediol, 2-methyl-1,3-propanediol, 3-methyl-1,3-butanediol (alias: isopentyl glycol), 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 3-methyl-1,5-pentanediol, 2-methylpentane-2,4-diol (alias: hexylene glycol), 1,6-hexanediol, 2-ethyl-2-methyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, neopentyl glycol (alias: 2,2-dimethyl-1,3-propanediol), pinacol (alias: 2,3-dimethyl-2,3-butanediol), etc.

[0094] The ink composition further contains a diol capped with hydroxyl groups at both ends and having 5 or fewer carbon atoms among the above-mentioned diols as an organic solvent. By selecting such a diol capped with hydroxyl groups at both ends, an image with further excellent image quality can be obtained.

[0095] Examples of alkane polyols include alkane diols, condensates formed by intermolecular condensation of two or more molecules of alkane diols through hydroxyl groups, alkanes having three or more hydroxyl groups, etc. The alkane diols mentioned above are also a kind of alkane polyols. Alkane polyols have two or more hydroxyl groups in the molecule.

[0096] Examples of condensates formed by intermolecular condensation of two or more molecules of alkane diols through hydroxyl groups include dialkylene glycols such as diethylene glycol and dipropylene glycol, and trialkylene glycols such as triethylene glycol and tripropylene glycol.

[0097] Alkanes having three or more hydroxyl groups are compounds having three or more hydroxyl groups with polyols having an alkane or polyether structure as a skeleton. Examples include compounds in which polyols having an alkane or polyether structure are substituted by three or more hydroxyl groups.

[0098] Examples of alkanes having three or more hydroxyl groups include glycerol, trimethylolethane, trimethylolpropane, 1,2,5-hexanetriol, 1,2,6-hexanetriol, pentaerythritol, polyoxypropylene triol, etc.

[0099] As alkylene glycol ethers, compounds obtained by etherifying one or more hydroxyl groups of the above-mentioned alkane polyols can be exemplified. Alkylene glycol monoethers obtained by etherifying one hydroxyl group or alkylene glycol diethers obtained by etherifying two hydroxyl groups can be exemplified. Alkylene glycol monoethers are more preferably used. It is preferred that the alkylene glycol ether has one hydroxyl group or no hydroxyl group in the molecule.

[0100] Examples of the etherification include alkyl ethers, aryl ethers, etc., and alkyl ethers are preferably used. It is preferred that the number of carbon atoms in the ether moiety of the etherification, that is, the number of carbon atoms in the terminal alkoxy group, is 1 or more and 8 or less, more preferably 1 or more and 4 or less. Additionally, it is preferably 1 or more and 3 or less, more preferably 1 or 2, and particularly preferably 1.

[0101] It is preferred that the number of carbon atoms in the alkylene glycol moiety of the alkylene glycol ether is 2 or more and 6 or less, more preferably 3 to 5. It is preferred that the repetition number of the alkylene glycol moiety is 1 or more and 5 or less. Additionally, it is preferably 1 to 3, more preferably 1 or 2, and particularly preferably 1.

[0102] As alkylene glycol ethers, alkylene glycol monoethers or alkylene glycol diethers can be exemplified, and alkylene glycol monoethers are more preferably used. As specific examples, 2-methoxyethanol (alias: ethylene glycol monomethyl ether), 2-ethoxyethanol (alias: ethylene glycol monoethyl ether), ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether (alias: butyl triethylene glycol), tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol monobutyl ether, 1-methoxy-2-propanol (alias: propylene glycol-1-monomethyl ether), 2-methoxypropanol (alias: propylene glycol-2-monomethyl ether), 1-ethoxy-2-propanol (alias: propylene glycol monoethyl ether), propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, 3-methoxy-1-propanol (alias: 1,3-propanediol monomethyl ether), 1-methoxy-2-butanol (alias: 1,2-butanediol-1-monomethyl ether), 2-methoxy-1-butanol, 3-methoxy-1-butanol (alias: 1,3-butanediol-3-monomethyl ether), 4-methoxy-1-butanol (alias: 1,4-butanediol monomethyl ether), 3-methoxy-3-methyl-1-butanol and other alkylene glycol monoethers; and

[0103] Alkylene glycol diether compounds such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol methyl ethyl ether, diethylene glycol methyl butyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol dibutyl ether, triethylene glycol methyl butyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetraethylene glycol dibutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, tripropylene glycol dimethyl ether, etc.

[0104] As esters, for example, acyclic esters, cyclic esters, etc. can be cited.

[0105] As acyclic esters, for example, glycol monoacetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, methoxybutyl acetate, etc.

[0106] Glycol diacetates such as ethylene glycol diacetate, diethylene glycol diacetate, propylene glycol diacetate, dipropylene glycol diacetate, ethylene glycol acetate propionate, ethylene glycol acetate butyrate, diethylene glycol acetate butyrate, diethylene glycol acetate propionate, diethylene glycol acetate butyrate, propylene glycol acetate propionate, propylene glycol acetate butyrate, dipropylene glycol acetate butyrate, dipropylene glycol acetate propionate, etc.

[0107] As cyclic esters, for example, cyclic esters (lactones) such as β-propiolactone, γ-butyrolactone, δ-valerolactone, ε-caprolactone, β-butyrolactone, β-valerolactone, γ-valerolactone, β-caprolactone, γ-caprolactone, δ-caprolactone, β-heptalactone, γ-heptalactone, δ-heptalactone, ε-heptalactone, γ-octalactone, δ-octalactone, ε-octalactone, δ-nonalactone, ε-nonalactone, ε-decalactone, etc., and compounds in which the hydrogen of the methylene adjacent to the carbonyl group of these is substituted with an alkyl group having 1 to 4 carbon atoms.

[0108] As amides, for example, cyclic amides, acyclic amides, etc. can be cited. As acyclic amides, oxyalkyl amides, etc. can be cited.

[0109] As cyclic amides, lactams can be exemplified. For example, pyrrolidones such as 2-pyrrolidone (standard boiling point 245°C), 1-methyl-2-pyrrolidone, 1-ethyl-2-pyrrolidone, 1-propyl-2-pyrrolidone, 1-butyl-2-pyrrolidone, 2-piperidone, ε-caprolactam, N-methyl-ε-caprolactam, N-cyclohexyl-2-pyrrolidone, 5-methyl-2-pyrrolidone, β-propiolactam, ω-heptolactam, succinimide, etc. Among them, 2-pyrrolidone and ε-caprolactam are particularly more preferred.

[0110] As non-cyclic amides, for example, 3-methoxy-N,N-dimethylpropanamide, 3-methoxy-N,N-diethylpropanamide, 3-methoxy-N,N-methylethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-diethylpropanamide, 3-ethoxy-N,N-methylethylpropanamide, 3-n-butoxy-N,N-dimethylpropanamide, 3-n-butoxy-N,N-diethylpropanamide, 3-n-butoxy-N,N-methylethylpropanamide, 3-n-propoxy-N,N-dimethylpropanamide, 3-n-propoxy-N,N-diethylpropanamide, 3-n-propoxy-N,N-methylethylpropanamide, 3-isopropoxy-N,N-dimethylpropanamide, 3-isopropoxy-N,N-diethylpropanamide, 3-isopropoxy-N,N-methylethylpropanamide, 3-tert-butoxy-N,N-dimethylpropanamide, 3-tert-butoxy-N,N-diethylpropanamide, 3-tert-butoxy-N,N-methylethylpropanamide and other oxyalkyl amides, N,N-dimethylacetoacetamide, N,N-diethylacetoacetamide, N-methylacetoacetamide, N,N-dimethylisobutyramide, N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylpropanamide, etc.

[0111] As sulfur-containing solvents, for example, sulfoxides, sulfones, etc. can be exemplified. As sulfoxides, for example, non-cyclic sulfoxides such as dimethyl sulfoxide and diethyl sulfoxide, and cyclic sulfoxides such as tetramethylene sulfoxide, etc. As sulfones, for example, cyclic sulfones such as 3-methyl sulfolane and sulfolane, and non-cyclic sulfones such as ethyl isopropyl sulfone, ethyl methyl sulfone, dimethyl sulfone, etc.

[0112] As cyclic ethers, for example, tetrahydrofuran, 1,4-dioxane, dimethyl isosorbide, 3-methyl-3-oxetane methanol, 3-ethyl-3-oxetane methanol, 2-hydroxymethyloxetane, tetrahydrofurfuryl alcohol, glycerol formal, sorbitol, 1,4-dioxane-2,3-diol, dihydrovinyl glucosone, etc. can be exemplified.

[0113] Two or more of these organic solvents can be appropriately mixed and used.

[0114] As the standard boiling point of the organic solvent, it is preferably 300 °C or lower, more preferably 280 °C or lower, still more preferably 270 °C or lower, still more preferably 250 °C or lower, further preferably 210 °C or lower, and particularly preferably 190 °C or lower. In addition, as the lower limit value of the standard boiling point of the organic solvent, there is no particular limitation, and it is preferably 100 °C or higher, further preferably 110 °C or higher, still more preferably 120 °C or higher, and further preferably 150 °C or higher.

[0115] In addition, as the organic solvent, when it contains 30.0% by mass or less of a compound having a standard boiling point of 250 °C or lower, the drying property of the image formed from the ink composition can be further improved. Here, as the organic solvent having a standard boiling point of 250 °C or lower, for example, 2-pyrrolidone (abbreviation: 2P, standard boiling point: 245 °C, classification: amides, property at 25 °C: liquid), dimethyl sulfoxide (abbreviation: DMSO, standard boiling point: 188 °C, classification: sulfur-containing solvents, property at 25 °C: liquid), 3-ethyl-3-oxetanemethanol (abbreviation: EOXM, standard boiling point: 220 °C, classification: cyclic ethers, property at 25 °C: liquid), 1,2-hexanediol (abbreviation: 1,2HD, standard boiling point: 224 °C, classification: alkane diols, property at 25 °C: liquid), 1,5-pentanediol (abbreviation: 1,5PD, standard boiling point: 239 °C, classification: alkane diols, property at 25 °C: liquid), etc. can be mentioned.

[0116] Preferably, the total content of the organic solvent is 3% by mass or more relative to the total mass of the ink composition. In addition, it is preferably 10.0% by mass or more, more preferably 15.0% by mass or more, and further preferably 20.0% by mass or more. On the other hand, the content of the organic solvent is preferably 40.0% by mass or less, more preferably 35.0% by mass or less, and further preferably 30.0% by mass or less relative to the total mass of the ink composition. In addition, it is preferably 25.0% by mass or less, and more preferably 20.0% by mass or less.

[0117] Among the exemplified organic solvents, it is further preferred that alkylene glycol monoethers as the organic solvent are contained in the ink composition according to the present embodiment. In addition, it is preferred that the number of carbon atoms of the alkoxy group at the terminal of the alkylene glycol monoether is 1 or more and 6 or less, more preferably 1 or more and 3 or less, and still more preferably 1 or 2. In addition, when using an alkylene glycol monoether, its standard boiling point is preferably 100 °C or higher and 280 °C or lower, further preferably 100 °C or higher and 200 °C or lower. More preferably, the standard boiling point of the alkylene glycol monoethers is 110 °C or higher and 190 °C or lower, further preferably 120 °C or higher and 180 °C or lower, and particularly preferably 130 °C or higher and 170 °C or lower.

[0118] Preferably, the content of the alkylene glycol monoether is 0.5% by mass or more and 20% by mass or less, more preferably 1% by mass or more and 15% by mass or less, further preferably 2% by mass or more and 10% by mass or less, and particularly preferably 3% by mass or more and 7% by mass or less, based on the total mass of the ink composition.

[0119] Thus, in the case where the silicone-based surfactant A tends to inhibit the wetting spreadability of the ink composition and the filling (color development) of the image tends to be poor, when the ink composition contains a glycol monoether solvent having a standard boiling point of 100°C or higher and 200°C or lower, this tendency of the silicone-based surfactant A can be inhibited, and an image with further better wetting spreadability and filling can be formed.

[0120] The following shows the standard boiling points and the number of carbon atoms in the terminal alkoxy group of some alkylene glycol monethers. 2-methoxyethanol (alias: ethylene glycol monomethyl ether, standard boiling point: 124°C, number of carbon atoms in the terminal alkoxy group (hereinafter, referred to as "C") is 1), 2-ethoxyethanol (alias: ethylene glycol monoethyl ether, standard boiling point: 136°C, C is 2), 1-methoxy-2-propanol (abbreviation: PM, alias: propylene glycol-1-monomethyl ether, standard boiling point: 120°C, C is 1), 1-ethoxy-2-propanol (abbreviation: PE, alias: propylene glycol monoethyl ether, standard boiling point: 132°C, C is 2), 2-methoxypropanol (alias: propylene glycol-2-monomethyl ether, standard boiling point: 102°C, C is 1), 3-methoxy-1-propanol (alias: 1,3-propanediol monomethyl ether, standard boiling point: 153°C, C is 1), 1-methoxy-2-butanol (alias: 1,2-butanediol-1-monomethyl ether, standard boiling point: 135°C, C is 1), 2-methoxy-1-butanol (standard boiling point: 146°C, C is 1), 3-methoxy-1-butanol (abbreviation: MB, alias: 1,3-butanediol-3-monomethyl ether, standard boiling point: 158°C, C is 1), 4-methoxy-1-butanol (alias: 1,4-butanediol monomethyl ether, standard boiling point: 165°C, C is 1), 3-methoxy-3-methyl-1-butanol (abbreviation: MMB, standard boiling point: 174°C, C is 1), diethylene glycol monomethyl ether (standard boiling point: 194°C, C is 1), diethylene glycol monoethyl ether (standard boiling point: 202°C, C is 2), dipropylene glycol monomethyl ether (abbreviation: DPM, standard boiling point: 190°C, C is 1).

[0121] In addition, when the ink composition contains an organic solvent, it is further preferable that the standard boiling point of the organic solvent having the highest standard boiling point among the organic solvents contained in the ink composition is 250°C or lower, and more preferably 240°C or lower. More preferably, it is 100°C or higher and 230°C or lower. In this way, an image with further excellent image quality can be obtained.

[0122] (5) Resin particles

[0123] The ink composition may further contain resin particles. By using resin particles, the abrasion resistance tends to be further improved. There is no particular limitation on the resin particles, and examples thereof include resin particles composed of polyurethane resins, acrylic resins (including styrene-acrylic resins), fluorene resins, polyolefin resins, rosin-modified resins, terpene resins, polyester resins, polyamide resins, epoxy resins, vinyl chloride resins, vinyl chloride-vinyl acetate copolymers, ethylene-vinyl acetate resins, and the like. The resin particles may be in the form of an emulsion.

[0124] Among them, acrylic resin particles, polyurethane resin particles, or polyester resin particles can be cited. By using such resin particles, the abrasion resistance tends to be further improved. These resin particles are mostly treated in the form of an emulsion, but may also be in the form of a powder. In addition, the resin particles may be used alone or in combination of two or more.

[0125] The polyurethane resin refers to the general name of resins having urethane bonds. For the polyurethane resin, in addition to the urethane bond, polyether-type polyurethane resins having an ether bond in the main chain, polyester-type polyurethane resins having an ester bond in the main chain, polycarbonate-type polyurethane resins having a carbonate bond in the main chain, etc. can also be used.

[0126] The acrylic resin is the general name of polymers obtained by polymerizing at least acrylic monomers such as (meth)acrylic acid and (meth)acrylate as one component, and examples thereof include resins obtained from acrylic monomers or copolymers of acrylic monomers and other monomers. For example, acrylic-vinyl resins, which are copolymers of acrylic monomers and vinyl monomers, can be cited. In addition, for example, as the vinyl monomer, styrene and the like can be cited. As the acrylic monomer, acrylamide, acrylonitrile, and the like can also be used.

[0127] Among them, it is preferably an acrylic resin, more preferably a styrene-acrylic resin. There is no particular limitation on the styrene-acrylic resin. For example, styrene-acrylic copolymer, styrene-methacrylic copolymer, styrene-methacrylic-acrylate copolymer, styrene-α-methylstyrene-acrylic copolymer, styrene-α-methylstyrene-acrylic-acrylate copolymer, etc. can be cited. By using such a resin, the friction resistance of the obtained recording tends to be further improved.

[0128] The polyolefin resin is a resin having olefins such as ethylene, propylene, and butene in its structural skeleton, and a known polyolefin resin can be appropriately selected and used.

[0129] Preferably, the content of the resin particles is 0.5% by mass or more and 6.0% by mass or less, more preferably 1.0% by mass or more and 5.0% by mass or less, and further preferably 2.0% by mass or more and 4.0% by mass or less with respect to the total mass of the ink composition. By making the content of the resin particles within the above range, the friction resistance tends to be further improved.

[0130] (6) Wax

[0131] The ink composition may also contain wax. There is no particular limitation on the wax. For example, hydrocarbon wax and ester wax which is a condensate of fatty acid and monohydric alcohol or polyhydric alcohol can be cited. There is no particular limitation on the hydrocarbon wax. For example, paraffin wax and polyolefin waxes such as polyethylene wax and polypropylene wax can be cited. These waxes can be used alone or in combination of two or more. Among these waxes, from the viewpoint of improving the friction resistance, hydrocarbon wax is preferred, polyolefin wax is more preferred, and polyethylene wax is further preferred.

[0132] The wax can also be in the state of an emulsion in which wax particles are dispersed in water, for example.

[0133] Preferably, the content of the wax is 0.1% by mass or more and 5.0% by mass or less, more preferably 0.3% by mass or more and 3.0% by mass or less, and further preferably 0.6% by mass or more and 1.5% by mass or less with respect to the total amount of the ink composition. The friction resistance of the obtained recording tends to be further improved.

[0134] (7) Other components

[0135] The ink composition may also appropriately contain various additives such as a cosolvent, a viscosity regulator, a pH regulator, an antioxidant, a preservative, a mildew preventive, a corrosion inhibitor, and a chelating agent.

[0136] (8) Combination of components, etc.

[0137] More preferably, the ink composition contains one or more of the glycol monoethers as the above-mentioned organic solvent or the above-mentioned silicone-based surfactant B. Thus, by the effects of any of these components, an image with further better wetting spreadability and filling (color development) can be formed.

[0138] (9) Preparation of the ink composition

[0139] The method for preparing the ink composition is not particularly limited. For example, a method of mixing the above-mentioned respective components and sufficiently stirring them so that the components are uniformly mixed can be cited.

[0140] 1.1.3. Inkjet recording device

[0141] While referring to the attached Figure 1 side, an example of an inkjet recording device that can be used for the recording method according to this embodiment will be described.

[0142] Figure 1 It is a schematic cross-sectional view schematically showing the inkjet recording device. Figure 2 It shows Figure 1 A perspective view of an example of the configuration around the carriage of the inkjet recording device 1. As Figure 1 , 2 shown, the inkjet recording device 1 includes an inkjet head 2, an IR heater 3, a platen heater 4, a heater 5, a cooling fan 6, a preheater 7, a ventilation fan 8, a carriage 9, a platen 11, a carriage moving mechanism 13, a conveyance unit 14, and a control unit CONT. The inkjet recording device 1 controls the overall operation of the inkjet recording device 1 through the Figure 2 control unit CONT shown.

[0143] The inkjet head 2 is configured to perform recording on the recording medium M by ejecting the ink composition from the nozzles of the inkjet head 2 and causing it to adhere. In this embodiment, the inkjet head 2 is a serial inkjet head, and scans relative to the recording medium M multiple times along the main scanning direction, thereby causing the ink to adhere to the recording medium M. The inkjet head 2 is mounted on the Figure 2 carriage 9 shown. The inkjet head 2 scans relative to the recording medium M multiple times along the main scanning direction through the operation of the carriage moving mechanism 13 that moves the carriage 9 along the medium width direction of the recording medium M. The medium width direction refers to the main scanning direction of the inkjet head 2. The scanning along the main scanning direction is referred to as the main scan.

[0144] In addition, here, the main scanning direction is the direction in which the carriage 9 on which the inkjet head 2 is mounted moves. In Figure 1 , the main scanning direction is a direction intersecting the conveyance direction of the recording medium M, which is the sub-scanning direction, indicated by the arrow SS. In Figure 2In this case, the width direction of the recording medium M, i.e., the direction represented by S1 - S2, is the main scanning direction MS, and the direction represented by T1 → T2 is the sub-scanning direction SS. In addition, in one scan, scanning is performed along the main scanning direction, i.e., either the direction of arrow S1 or arrow S2. Then, by repeating the main scan of the inkjet head 2 and the sub-scan as the conveyance of the recording medium M multiple times, recording is performed on the recording medium M. That is, the process liquid attachment step and the ink attachment step are performed by multiple main scans in which the inkjet head 2 moves along the main scanning direction and multiple sub-scans in which the recording medium M moves along the sub-scanning direction intersecting the main scanning direction.

[0145] The ink cartridges 12 that supply the ink composition to the inkjet head 2 respectively include a plurality of independent ink cartridges. The ink cartridges 12 are detachably mounted on the carriage 9 on which the inkjet head 2 is mounted. Different types of ink compositions and the like are filled in the plurality of ink cartridges, and the ink composition is supplied from the ink cartridges 12 to each nozzle. In addition, in the present embodiment, an example in which the ink cartridges 12 are mounted on the carriage 9 is shown, but it is not limited thereto, and the ink cartridges 12 may be provided at a position other than the carriage 9, and the ink composition may be supplied to each nozzle through a supply pipe (not shown).

[0146] The ejection of the inkjet head 2 can use a conventionally well-known method. In the present embodiment, a method of ejecting droplets by the vibration of a piezoelectric element is used, that is, an ejection method in which ink droplets are formed by the mechanical deformation of an electrostrictive element.

[0147] The inkjet recording apparatus 1 is provided with a ventilation fan 8, an IR heater 3, and a platen heater 4 for drying the ink composition ejected from the inkjet head 2 and attached to the recording medium M. By appropriately combining the use of these ventilation fan 8, IR heater 3, and platen heater 4, a primary drying process can be performed. In the primary drying process, it is not necessarily required to heat the recording medium M, and the ventilation fan 8 can also be used alone for blowing air at room temperature.

[0148] In addition, when the IR heater 3 is used, the recording medium M can be heated by radiation of infrared rays from the side of the inkjet head 2 in a radiative manner. As a result, the inkjet head 2 is also easily heated at the same time, but compared with the case of heating from the back surface of the recording medium M such as the platen heater 4, the temperature can be raised without being affected by the thickness of the recording medium M. In addition, various fans (such as the ventilation fan 8) that blow hot air or air at the same temperature as the environment to the recording medium M to dry the ink on the recording medium M may also be provided.

[0149] The platen heater 4 can heat the recording medium M across the platen 11 at a position facing the inkjet head 2, so that the ink composition ejected from the inkjet head 2 dries as soon as possible from the time it adheres to the recording medium M. The platen heater 4 can heat the recording medium M in a conduction manner. In the recording method of the present embodiment, the ink composition can also be made to adhere to the recording medium M that is heated in this way. In this case, the ink composition can sometimes be fixed on the recording medium M as soon as possible, thereby improving the image quality.

[0150] The heater 5 is a heater for drying and curing the ink composition adhering to the recording medium M, that is, for secondary heating or secondary drying. The heater 5 can be used in the post-drying process. By heating the recording medium M on which an image is recorded, the heater 5 causes the moisture, organic solvents, etc. contained in the ink composition to evaporate and disperse more rapidly, so that an ink film is formed from the resin that may be contained in the ink composition. In this way, the ink film is firmly fixed or adhered on the recording medium M, with excellent film-forming properties, and a high-quality image can be obtained in a short time.

[0151] The inkjet recording apparatus 1 may also have a cooling fan 6. After drying the ink composition recorded on the recording medium M, the cooling fan 6 cools the ink composition on the recording medium M, so that an ink coating film with good adhesion can be formed on the recording medium M.

[0152] In addition, the inkjet recording apparatus 1 may also have a preheater 7 to preheat the recording medium M before the ink composition adheres to the recording medium M. Moreover, the inkjet recording apparatus 1 may also have a ventilation fan 8 so that the ink composition adhering to the recording medium M dries more efficiently.

[0153] Below the carriage 9 are provided: a platen 11 for supporting the recording medium M; a carriage moving mechanism 13 for relatively moving the carriage 9 with respect to the recording medium M; and a conveying unit 14 for conveying the recording medium M along the sub-scanning direction as a roller. The operations of the carriage moving mechanism 13 and the conveying unit 14 are controlled by the control unit CONT.

[0154] The inkjet recording apparatus exemplified above can preferably be used for implementing the recording method according to the present embodiment. In addition, in Figure 1 、 2 a serial inkjet recording apparatus is provided, but in the recording method of the present embodiment, a line inkjet recording apparatus can also be used.

[0155] 1.1.4. Specific manner of the attachment process

[0156] For example, by using, as an embodiment of the above inkjet recording apparatus Figure 1The inkjet recording apparatus 1 shown ejects ink from an inkjet head 2 and easily performs an attachment process.

[0157] The recording method of the present embodiment relates to a method of attaching an ink composition. For example, the following methods can be cited. In addition, "main scanning" can be abbreviated as scanning, which means moving the relative position of the inkjet head with respect to the recording medium, and ejecting the ink composition from the inkjet head and attaching it to the recording medium. The inkjet head can be mounted on a carriage, for example. The inkjet head can also be moved by moving the carriage. In this case, it is the movement of the inkjet head.

[0158] In addition, the "main scanning direction" refers to the moving direction of the relative position of the above-mentioned inkjet head with respect to the recording medium. In the case of a serial type, it is the width direction of the recording medium. In addition, "main scanning" is the movement of the relative position of the inkjet head with respect to the recording medium. The inkjet head can move with respect to the recording medium, or the recording medium can move with respect to the inkjet head. The moving direction of this relative position is the main scanning direction. The movement of the relative position of the inkjet head with respect to the recording medium can be called the movement of the relative position of the recording medium with respect to the inkjet head. That is, it is the movement of the relative position between the inkjet head and the recording medium.

[0159] On the other hand, "sub-scanning" refers to the action of moving the relative position of the inkjet head and the recording medium along the sub-scanning direction. The "sub-scanning direction" refers to the direction that intersects the main scanning direction.

[0160] For example, recording can be performed by repeating the following actions: by attaching the ink composition to a certain area of the recording medium during main scanning, slightly moving the recording medium during sub-scanning, for example, and then performing the next main scanning, thereby attaching the ink composition adjacent to or partially overlapping the just-attached ink composition. In addition, "sub-scanning" is the movement of the relative position of the inkjet head with respect to the recording medium. The inkjet head can move with respect to the recording medium, or the recording medium can move with respect to the inkjet head. The relative moving direction is the sub-scanning direction. Sub-scanning is not scanning, and it is not the action of ejecting ink and attaching it to the recording medium.

[0161] In this way, by repeating main scanning and sub-scanning multiple times respectively, the recording method of the present embodiment can be implemented. In addition, for example, by alternately repeating main scanning and sub-scanning, the recording method of the present embodiment can be implemented.

[0162] In the attachment process of the present embodiment, the relative position of the inkjet head with respect to the recording medium is moved multiple times, and scanning (main scanning) in which the ink composition is ejected and attached to the recording medium is performed, and the same area of the recording medium is scanned seven times or less. In the case of a line type, the scanning is once.

[0163] That is, when droplets of the ink composition are attached to a certain area on the recording medium by a certain main scan, droplets of the ink composition can be further attached overlappingly thereto by another main scan, and the number of overlaps is seven or less. In this case, the main scan for attaching the ink composition to the same area is performed seven or less times. Thereby, the speed of forming a recording can be increased, and the productivity can be improved.

[0164] In addition, when recording an arbitrary area, the number of times the inkjet head passes over the area is referred to as the "number of passes" or "number of scans". For example, in the case of performing four main scans for attaching the ink composition to the same area, it is referred to as "the number of passes is four passes", "the number of scans is four", etc.

[0165] For example, in Figure 2 the example, when the length of one sub-scan in the sub-scanning direction is one-fourth of the length of the nozzle array of the inkjet head arranged along the sub-scanning direction in the sub-scanning direction, four main scans can be performed on a rectangular scanning area that is one sub-scan length in the sub-scanning direction and extends along the main scanning direction, on the same part (the same scanning area). The number of scans observed in this way is referred to as the number of scans or the number of passes, etc. The number of scans is 7 or less, more preferably 1 or more and 6 or less, and further preferably 2 or more and 5 or less.

[0166] The amount of attachment of the ink composition is preferably 2.0 mg / inch 2 or more and 20 mg / inch 2 on the per unit area of the area on the recording medium where the ink composition is attached (hereinafter, also referred to as the "attachment area of the ink composition"), more preferably 3.0 mg / inch 2 or more and 10 mg / inch 2 . The area for confirming the amount of attachment is, for example, an area of about 2 mm × 2 mm. By making the amount of attachment of the ink composition within the above range, the image quality of the obtained recording tends to be further excellent.

[0167] In addition, in the main scan, the time for one main scan is preferably 0.5 seconds or more and 5 seconds or less, more preferably 1 second or more and 4 seconds or less, and further preferably 2 to 3 seconds. The time for one main scan (also referred to as the main scan time) is the time required for the position of the inkjet head to move from the position opposed to one end of the recording medium to the position opposed to the other end of the recording medium in one main scan.

[0168] 1.2. Other processes

[0169] The recording method of this embodiment may include the following processes in addition to the attachment process.

[0170] 1.2.1. Primary drying process

[0171] The recording method of the present embodiment may also include a primary drying process for drying the ink composition attached to the recording medium by a drying mechanism. The primary drying process is a process of heating the recording medium before the attaching process, or heating or blowing air to the recording medium during the attaching process or at an early stage after the ink composition is attached to the recording medium to dry the ink composition. The primary drying process is used to dry the ink composition attached to the recording medium so that at least a part of the solvent component of the ink composition is dried to at least a degree that reduces the flow of the ink composition.

[0172] In the primary drying process, the ink composition may be attached to the heated recording medium, or may be carried out at an early stage after attachment to promote drying. In the primary drying process, it is preferable to start drying the ink droplet (ink dot) dropped on the recording medium within at most 0.5 seconds from the start of the dropping of the ink droplet. As the drying unit (drying mechanism) for drying the ink composition on the recording medium, there is no particular limitation, and examples thereof include a conduction type such as a platen heater having a heating function, a radiation type such as an IR heater, and a blower type such as a hot air fan or a fan without a heating function.

[0173] As the type of the drying mechanism, there can be mentioned a conduction type that conducts heat from a component in contact with the recording medium to the recording medium to heat the recording medium, a radiation type that radiates radiation such as IR to the recording medium to heat the recording medium, a blowing type that blows air to the recording medium, etc. The blowing type can include a method of blowing hot air to heat the recording medium and a method of promoting the drying of the ink using normal temperature air without heating. In the case of the method without heating, it is possible to suppress the reduction of the ejection stability due to the drying of the ink composition at the nozzles of the inkjet head, and thus it is preferable. It is also preferable to use either the conduction type or the radiation type in combination with the blowing type. In the case of combination, the blowing type can also be a method without heating, which is preferable.

[0174] In the primary drying process, it is preferable that the surface temperature of the recording medium is 50 °C or lower, more preferably 45 °C or lower. In addition, it is more preferably 30 °C or higher and 42 °C or lower, and further preferably 32 °C or higher and 40 °C or lower. In addition, it is preferably 35 °C or higher and 48 °C or lower, more preferably 40 °C or higher and 45 °C or lower.

[0175] By making the surface temperature of the recording medium within the above range, it is possible to further improve the drying property, further suppress the merging and mixing of the ink dots of the ink composition, suppress the unevenness of the image, further improve the visual recognition or optical density, and in addition, there is a tendency to further improve the abrasion resistance of the obtained recording.

[0176] In the case of using the air supply type, it is preferable that the wind speed near the recording medium is 0.5 m / s or more and 15 m / s or less, more preferably 1 m / s or more and 10 m / s or less, and still more preferably 2 m / s or more and 5 m / s or less. It is preferable that the wind temperature is 45°C or less, more preferably 40°C or less, still more preferably 32°C or less, and particularly preferably 20°C or more and 27°C or less. In this way, an image with further excellent image quality can be obtained.

[0177] 1.2.2. Secondary drying process

[0178] The secondary drying process is a process of heating the recording medium after the coating process. The secondary drying process is a process of completing the recording and heating it sufficiently to a degree where the recording can be used. The secondary drying process is a process for sufficiently drying the solvent component of the ink composition and heating the resin, wax, etc. contained in the ink composition, thereby making the coating film of the ink composition flat. It is preferable that the secondary drying process starts 0.5 seconds after the ink composition adheres to the recording medium. For example, it is preferable that heating of a certain recording area starts 0.5 seconds after the ink composition completely adheres to the recording medium in that area. At this time, it is preferable that the surface temperature of the low-absorbency recording medium or non-absorbency recording medium is 50°C or more and 100°C or less, more preferably 60°C or more and 90°C or less, and still more preferably 70°C or more and 80°C or less. By making the surface temperature of the recording medium within the above range, the abrasion resistance of the obtained recording tends to be further improved. As the secondary drying mechanism, a conduction type, a radiation type, an air supply type, etc. can be used.

[0179] 1.3. Function and effect

[0180] According to the recording method of the present embodiment, since an ink composition containing the organosilicon surfactant A having a definite molecular weight distribution is used, even when the number of passes during recording on a low-absorbency recording medium or non-absorbency recording medium is reduced to seven or less, it is possible to reduce the aggregation unevenness of the ink dots of the ink composition, improve the recording speed, and obtain an image with excellent image quality.

[0181] In the recording method of the present embodiment, by making the ink composition contain the high molecular weight organosilicon surfactant A, even when the number of passes is reduced, the aggregation unevenness of the ink dots can be reduced, the recording speed can be increased, and an image with excellent image quality can be obtained. It is speculated that this is because the high molecular weight organosilicon surfactant A can suppress the flow of the ink composition, thereby reducing the aggregation unevenness. Especially when the solvent component of the ink composition evaporates on the recording medium and the solid component becomes highly concentrated, the effect of reducing the fluidity of the ink composition is high. This effect can also be referred to as the pinning effect of the ink composition on the recording medium.

[0182] In addition, in a line printer corresponding to one pass, good results can also be obtained by this recording method.

[0183] In addition, the organosilicon surfactant A sometimes causes slightly poor wetting and spreading properties of the ink composition, which may reduce filling (color development, OD value). However, when the ink composition contains glycol monoethers and the organosilicon surfactant B, the wetting and spreading properties of the organosilicon surfactant A can be fully compensated, and the filling (color development, OD value) can be made more excellent. This is considered to be based on the following mechanism: after the ink composition is wetted and spread by the glycol monoethers and / or the organosilicon surfactant B, when the evaporation of the ink composition proceeds, the fluidity is reduced by the organosilicon surfactant A, thereby preventing aggregation unevenness. In addition, it is considered that the glycol monoethers are easily evaporated on the recording medium, and after the ink composition is wetted and spread, the wetting and spreading properties become very small, causing this effect.

[0184] 2. Examples and Comparative Examples

[0185] Hereinafter, the present invention will be specifically described further by way of examples, but the present invention is not limited to these examples. Hereinafter, unless otherwise specified, "%" is based on mass.

[0186] 2.1. Preparation of Ink Composition

[0187] According to the components described in Tables 1 to 3 below, each component was mixed to obtain an ink composition. In addition, the components in Tables 1 to 3 are expressed in mass%. In addition, the pigment and resin particles in the table represent the solid components. In addition, the pigment was previously mixed and stirred with a dispersant which is a water-soluble styrene acrylic resin in a mass ratio of pigment:dispersant = 2:1 in water to prepare a pigment dispersion liquid, and it was used for the preparation of the ink composition. Ion-exchanged water was added so that the total mass of the treatment liquid became 100 mass%.

[0188]

Table 1

[0189]

[0190]

Table 2

[0191]

[0192]

Table 3

[0193]

[0194] In the above Tables 1 to 3, "b.p." represents the standard boiling point. In addition, the characteristics of each substance described other than by the substance name in Tables 1 to 3 are as follows.

[0195] Colorant

[0196] · P.B.15:3: Pigment Blue 15:3

[0197] · Fixing resin: Styrene acrylic resin (Joncryl537J)

[0198] · Wax: Polyethylene wax (AQUACER539)

[0199] · Surfactant A: Silicone-based surfactant A

[0200] · BYK333 (maximum peak: 6760) Manufactured by BYK-Chemie Janan Co., Ltd.

[0201] · Preparation Example 1 (maximum peak: 6500)

[0202] · BYK3480 (maximum peak: 4330) Manufactured by BYK-Chemie Janan Co., Ltd.

[0203] · Surfactant B: Silicone-based surfactant B

[0204] · KF-6204 (maximum peak: less than 3000, HLB: 10) Manufactured by Shin-Etsu Silicone Co., Ltd.

[0205] · Tegowet280 (maximum peak: less than 3000, HLB: 3.5) Manufactured by EVONIK Industries AG

[0206] · Other surfactants

[0207] · SAG503A (HLB: 11, maximum peak: less than 3000, manufactured by Nissin Chemical Industry Co., Ltd., silicone-based surfactant, Silface SAG503A)

[0208] · PD002W (manufactured by Nissin Chemical Industry Co., Ltd., alkynediol-based surfactant, Olfine PD002W)

[0209] · Preparation Example 1 (Silicone Surfactant A): Synthesis was carried out as follows.

[0210] A specified organohydrogen polysiloxane was reacted with a corresponding polyether having a carbon-carbon double bond at the molecular end through platinum catalysis. Thus, structure analysis was performed by liquid chromatography-mass spectrometry (LC-MS), and a silicone surfactant A of Preparation Example 1 satisfying d = 4 to 6, e = 13 to 15, f = 4 to 12, g = 0, R 3 = CH3, R 4 = -CH2-, R 5 = H was obtained.

[0211] 2.2. Molecular Weight Distribution Measurement

[0212] The molecular weight distributions of silicone surfactant A and silicone surfactant B in Tables 1 to 3 were measured by gel permeation chromatography, and the maximum peak in the range of molecular weight of 300 or more was obtained. The results are shown in the table. The measurement conditions are as follows.

[0213] <Measurement Conditions>

[0214] · Solvent: Tetrahydrofuran

[0215] · Column: TSKgel SuperHZM-N × 2

[0216] · + TSKgel guard column SuperHZ-L

[0217] · Column Temperature: 40 °C

[0218] · Injection Volume: 25 μL

[0219] · Detector: Differential Refractometer (RI)

[0220] · Flow Rate: 0.35 mL / min

[0221] · Calibration Curve: A calibration curve based on 13 samples of standard polystyrene STK standard polystyrene (manufactured by TOSOH Corporation) with Mw = 1,000,000 to 500 was used.

[0222] 2.3. Evaluation Method

[0223] A printer (a modified machine of SC-S80650 manufactured by Seiko Epson Corporation) was prepared, and each ink composition was filled into 1 nozzle row of the inkjet head. The inkjet head of the printer used a nozzle row with a nozzle density of 360 dpi and had an inkjet head with 360 nozzles. In addition, as Figure 1As shown, the printer has a platen heater for primary drying at a position opposite to the inkjet head, and controls the surface temperature of the recording medium to the values described in Tables 4 to 7. Further, a secondary heater is provided downstream of the printer, and in the secondary drying, the surface temperature of the recording medium is adjusted to 70°C. Here, as the primary drying mechanism in this embodiment, a platen heater and a blower fan are provided, and the wind speed of the fan is set to the value in the table. The wind speed is the wind speed near the surface of the recording medium directly below the inkjet head. The air temperature is measured in advance so as not to be affected by the platen heater and is measured near the surface of the recording medium.

[0224] Using the printer configured as described above, solid patterns were recorded on PET50A (manufactured by Lintec, transparent PET film: recording medium type M1 or plain paper: recording medium type M2) under the conditions described in Tables 4 to 7 at a recording resolution of 720×720 dpi. Further, the number of ink droplets or the amount of ink droplets per pass was adjusted according to the number of passes, and thereby the ink adhesion amount was set to 7 mg / inch 2 .

[0225]

Table 4

[0226]

[0227]

Table 5

[0228]

[0229]

Table 6

[0230]

[0231]

Table 7

[0232]

[0233] 2.3.1. Image quality (non-uniformity)

[0234] The solid images of the recorded objects in each example were observed visually, and the visual recognition was evaluated according to the following evaluation criteria. When the pinning effect of the ink composition is small, the evaluation is low.

[0235] A: No color shading non-uniformity was observed in the pattern.

[0236] B: Slight fine shading non-uniformity was observed.

[0237] C: Clear fine shading non-uniformity was observed.

[0238] D: Significant shading non-uniformity was observed.

[0239] 2.3.2. Image quality (OD value)

[0240] For the solid image of the recording obtained as described above, the OD value was measured using a colorimeter (i1Pro2, manufactured by X-rite Inc.) under the following measurement conditions, and the color rendering property was evaluated according to the following evaluation criteria.

[0241] Measurement conditions

[0242] Measuring device: i1Pro2 (manufactured by X-rite Inc.)

[0243] Measurement conditions: D50 light source, state T, standard observer 2°

[0244] Background: white paper

[0245] Evaluation criteria

[0246] A: OD value is 1.2 or more

[0247] B: 1 or more and less than 1.2

[0248] C: 0.8 or more and less than 1

[0249] D: less than 0.8

[0250] 2.3.3. Rub resistance

[0251] For the recording obtained as described above, using a Gakushin type friction fastness tester AB-301 (manufactured by TESTERSANGYO CO,.LTD.), a test was conducted in which No. 3 cotton cloth was reciprocated 50 times under a load of 500 g (JIS P8136). The rub resistance was evaluated according to the following evaluation criteria.

[0252] Evaluation criteria

[0253] A: No peeling of the image was found

[0254] B: There is peeling of more than 0% and less than 10%

[0255] C: There is peeling of 10% or more and less than 40%

[0256] D: There is peeling of 40% or more, or the recording medium is damaged

[0257] 2.3.4. Inkjet stability

[0258] Recording was performed for 2 hours according to the recording test conditions. Among them, it was set as a simulation recording in which the ink composition was not ejected from the inkjet head during the recording process. After recording, suction cleaning was performed to restore the non-ejecting nozzles, and then a nozzle check was conducted. One cleaning was to discharge 1 cc of ink from the nozzle row.

[0259] A: After one cleaning, all nozzles are restored

[0260] B: After three cleanings, all nozzles are restored

[0261] C: After six cleanings, all nozzles are restored

[0262] D: After six cleanings, there are nozzles that are not restored

[0263] 2.3.5. Productivity

[0264] Set the recorded number of strokes as an index of productivity. The evaluation criteria for productivity are shown below.

[0265] Evaluation Criteria

[0266] A: Four strokes or less

[0267] B: More than four strokes and seven strokes or less

[0268] C: More than seven strokes

[0269] 2.4. Evaluation Results

[0270] In each of the examples where the number of scans is seven or less and the ink composition is an aqueous ink containing a coloring material and a silicone-based surfactant A, the image quality (non-uniformity) of the obtained image is excellent and the productivity is also excellent. In comparative examples where this is not the case, at least one of the image quality (non-uniformity) and productivity is poor.

[0271] The above-described embodiments and modification examples are just examples and are not limited thereto. For example, it is also possible to appropriately combine each embodiment and each modification example.

[0272] The present invention includes configurations that are substantially the same as those described in the embodiments, such as configurations having the same functions, methods, and results or configurations having the same purposes and effects. In addition, the present invention includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. In addition, the present invention includes configurations that exhibit the same effects as the configurations described in the embodiments or configurations that can achieve the same purpose. In addition, the present invention includes configurations in which known techniques are added to the configurations described in the embodiments.

[0273] Based on the above-described embodiments and modification examples, the following can be derived.

[0274] The recording method has an attaching step of attaching an ink composition to a recording medium, which is a low-absorbency recording medium or a non-absorbency recording medium. The attaching step is performed by scanning the ink composition from an inkjet head and attaching it to the recording medium while moving the relative position of the inkjet head and the recording medium. The number of times of scanning the same area of the recording medium is seven times or less. The ink composition is an aqueous ink containing a coloring material and a silicone-based surfactant A. In the molecular weight distribution of the silicone-based surfactant A in gel permeation chromatography, there is a maximum peak in the range of 3000 to 20000 with a molecular weight of 300 or more.

[0275] According to this recording method, since an ink composition containing a silicone-based surfactant A having a determined molecular weight distribution is used, even when the number of passes during recording on a low-absorbency recording medium or a non-absorbency recording medium is reduced to seven times or less, it is possible to reduce the aggregation unevenness of the ink dots of the ink composition, improve the recording speed, and obtain an image with excellent image quality.

[0276] In the above recording method, the content of the silicone-based surfactant A relative to the total amount of the ink composition may be 0.05% by mass or more and 1.5% by mass or less.

[0277] According to this recording method, an image with further excellent image quality can be obtained.

[0278] In the above recording method, the ink composition may further contain a glycol monoether as an organic solvent, and one or more of silicone-based surfactants B that do not have a maximum peak in the range of 3000 or more with a molecular weight of 300 or more and have an HLB value of 10.5 or less according to the Griffin method in the molecular weight distribution in gel permeation chromatography.

[0279] According to this recording method, since an ink composition further containing a silicone-based surfactant B having a larger molecular weight than the silicone-based surfactant A is used, the wetting spreadability of the ink composition on the recording medium is more excellent, and an image with more excellent filling (color development) of ink dots can be formed. In addition, when a glycol monoether is included, an image with further better wetting spreadability and filling can be formed.

[0280] In the above recording method, the ink composition may contain a glycol monoether as an organic solvent, and the standard boiling point of the glycol monoether is 100°C or more and 200°C or less.

[0281] According to this recording method, the silicone-based surfactant A tends to inhibit the wetting spreadability of the ink composition, and there is a tendency for poor filling (color development) of the image. However, when the ink composition contains a glycol monoether solvent having a standard boiling point of 100°C or higher and 200°C or lower, an image with further better wetting spreadability and filling can be formed.

[0282] In the above recording method, the number of carbon atoms in the ether moiety of the glycol monoether may be 2 or less.

[0283] According to this recording method, an image with further better wetting spreadability and filling can be formed.

[0284] In the above recording method, the silicone-based surfactant A may be a compound represented by the following general formula (1) or general formula (3).

[0285]

[0286] (In general formula (1), R 1 each independently represents an alkylene group having 1 to 6 carbon atoms or a single bond, X 1 each independently represents a polyether group represented by the following general formula (2), and a represents an integer of 10 or more and 80 or less)

[0287]

[0288] (In general formula (2), R 2 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an (meth)acrylic group, EO represents an ethylene oxide group, PO represents a propylene oxide group, the order of EO and PO is a random order, b represents an integer of 0 or more, c represents an integer of 0 or more, and b + c is 1 or more)

[0289]

[0290] (In general formula (3), R 3 each independently represents an alkyl group having 1 to 6 carbon atoms, X 2 each independently represents a polyether group represented by the following general formula (4), and d and e represent integers of 1 or more, and d + e is 2 or more and 50 or less)

[0291]

[0292] (In general formula (4), R 4 represents an alkylene group having 1 to 6 carbon atoms or a single bond, R 5represents an alkyl group having 1 or more and 6 or less carbon atoms or hydrogen atoms, EO represents an ethylene oxide group, PO represents a propylene oxide group, the order of EO and PO is a random order, f represents an integer of 0 or more, g represents an integer of 0 or more, and f + g is 1 or more)

[0293] According to this recording method, an image with further excellent image quality can be obtained.

[0294] In the above recording method, the total content of the surfactant in the ink composition may be 2.0% by mass or less relative to the total amount of the ink composition.

[0295] According to this recording method, an image with further excellent image quality can be obtained.

[0296] In the above recording method, the ink composition may contain an organic solvent, and the standard boiling point of the organic solvent having the highest standard boiling point among the organic solvents contained in the ink composition is 250°C or less.

[0297] According to this recording method, an image with further excellent image quality can be obtained.

[0298] In the above recording method, in the attaching step, the scanning and the sub-scanning in which the relative position of the inkjet head and the recording medium is moved in a direction crossing the scanning direction may be performed multiple times respectively, and the number of times of the scanning performed on the same area of the recording medium is 2 or more and 5 or less.

[0299] According to this recording method, a recording object with further good productivity can be obtained.

[0300] In the above recording method, the ink composition may contain a diol having both ends terminated with hydroxyl groups and having 5 or less carbon atoms as an organic solvent.

[0301] According to this recording method, an image with further excellent image quality can be obtained.

[0302] In the above recording method, a drying step may be further included.

[0303] According to this recording method, an image with further excellent image quality can be obtained.

[0304] In the above drying step, the drying by blowing air may be included, and the wind speed of the blowing air is 0.5 m / s or more and 15 m / s or less.

[0305] According to this recording method, an image with further excellent image quality can be obtained.

[0306] In the above drying step, the surface temperature of the recording medium may be 45°C or less.

[0307] According to this recording method, an image with further excellent image quality can be obtained.

Claims

1. A recording method, characterized in that, There is an attaching step of attaching the ink composition to a recording medium, wherein the recording medium is a low-absorbency recording medium or a non-absorbency recording medium, and the attaching step is performed by scanning, which is to eject the ink composition from the inkjet head and attach it to the recording medium while moving the relative position of the inkjet head and the recording medium, the number of times of performing the scanning on the same area of the recording medium is seven times or less, the ink composition is an aqueous ink containing a coloring material and a silicone-based surfactant A, in the molecular weight distribution of the silicone-based surfactant A in gel permeation chromatography, there is a maximum peak in the range of 3000 to 20000 with a molecular weight of 300 or more, the ink composition further contains: a glycol monoether as an organic solvent, and one or more of silicone-based surfactants B that do not have a maximum peak in the range of 3000 or more with a molecular weight of 300 or more and have an HLB value of 10.5 or less according to the Griffin method in the molecular weight distribution in gel permeation chromatography.

2. The recording method according to claim 1, wherein the content of the silicone-based surfactant A is 0.05% by mass or more and 1.5% by mass or less relative to the total amount of the ink composition.

3. The recording method according to claim 1, wherein the content of the silicone-based surfactant B is 0.05% by mass or more relative to the total amount of the ink composition.

4. The recording method according to claim 1, wherein the ink composition contains a glycol monoether as an organic solvent, and the standard boiling point of the glycol monoether is 100 °C or more and 200 °C or less.

5. The recording method according to claim 4, wherein the number of carbon atoms in the ether moiety of the glycol monoether is 2 or less.

6. The recording method according to claim 1, wherein the silicone-based surfactant A is a compound represented by the following general formula (1) or general formula (3), In general formula (1), R 1 each independently represents an alkylene group having 1 to 6 carbon atoms or a single bond, and X 1 each independently represents a polyether group represented by the following general formula (2), and a represents an integer of 10 or more and 80 or less. In general formula (2), R 2 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an (meth)acrylic group, EO represents an ethyleneoxy group, PO represents a propyleneoxy group, the order of EO and PO is a random order, b represents an integer of 0 or more, c represents an integer of 0 or more, b + c is 1 or more, In general formula (3), R 3 each independently represents an alkyl group having 1 to 6 carbon atoms, and X 2 each independently represents a polyether group represented by the following general formula (4), d and e represent integers of 1 or more, and d + e is 2 or more and 50 or less. In general formula (4), R 4 represents an alkylene group having 1 to 6 carbon atoms or a single bond, R 5 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, EO represents an ethyleneoxy group, PO represents a propyleneoxy group, the order of EO and PO is a random order, f represents an integer of 0 or more, g represents an integer of 0 or more, and f + g is 1 or more.

7. The recording method according to any one of claims 1 to 6, wherein the total content of surfactants in the ink composition is 2.0% by mass or less relative to the total amount of the ink composition.

8. The recording method according to any one of claims 1 to 6, wherein the ink composition contains an organic solvent, and the standard boiling point of the organic solvent having the highest standard boiling point among the organic solvents contained in the ink composition is 250 °C or less.

9. The recording method according to any one of claims 1 to 6, wherein in the attaching step, multiple scans and sub-scans are performed respectively, the number of times of performing the scan on the same area of the recording medium is two or more and five or less, and the sub-scan is to move the relative position of the inkjet head and the recording medium along a direction intersecting with the direction of the scan.

10. The recording method according to any one of claims 1 to 6, wherein the ink composition contains a diol having hydroxyl groups at both ends with 5 or less carbon atoms as an organic solvent.

11. The recording method according to any one of claims 1 to 6, characterized in that the recording method further includes a primary drying process.

12. The recording method according to claim 11, characterized in that the primary drying process includes drying by air supply, and the wind speed of the air supply is 0.5 m / s or more and 15 m / s or less.

13. The recording method according to claim 11, characterized in that the surface temperature of the recording medium in the primary drying process is 45°C or less.

Images