Ink set and recording method

Abstract

To provide an ink set which enables provision of an image excellent in scratch resistance and enables recording with good clogging recoverability.SOLUTION: An ink set includes: an aqueous inkjet ink composition containing a coloring material and resin particles; and a treatment liquid containing a coagulant. Therein the resin particles contain first resin particles made of an acrylic resin having a glass transition point of 60°C or higher and 110°C or lower, second resin particles made of a polyester-based resin having a glass transition point of 60°C or higher and 110°C or lower, and third resin particles made of a polyolefin-based resin having a melting point of 110°C or higher and 150°C or lower. In the inkjet ink composition, a content of the second resin particles is 0.4 time or less a content of the first resin particles.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an ink set and a recording method. [Background technology]

[0002] Since the inkjet method can form high-quality images on a recording medium, various technical developments have been made in the past. For example, not only the development of recording devices using the inkjet method but also the development of compositions to be used in the devices is active. Furthermore, a wide range of studies are being made on combinations of recording devices, ink compositions, treatment liquids, recording media, etc., and recording methods using these.

[0003] For example, there is a recording method that uses a treatment liquid to quickly reduce and fix the fluidity of the ink to obtain excellent image quality. For example, Patent Document 1 describes an attempt to improve the image quality of the obtained image by using a treatment liquid for an ink composition containing an acrylic resin and polyethylene wax. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-167518 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the treatment liquid aggregates the components of the ink composition and reduces the fluidity, so that the components attached to the recording medium surface are difficult to smooth due to the aggregates of the ink components, and the adhesion of the recorded matter (abrasion resistance due to adhesion) tends to decrease. In addition, acrylic resins have been used as fixing resins used in ink compositions because they are easily available, but the adhesion of the image is insufficient and the abrasion resistance is poor. On the other hand, the adhesion can be improved by using a polyester resin, but the polyester resin is easily turned into foreign matter in the ink composition, and clogging recovery may be insufficient. [Means for solving the problem]

[0006] One aspect of the ink set according to the present invention is The ink set is a water-based ink-jet ink composition containing a colorant and resin particles; A treatment liquid containing a flocculant; An ink set having the formula: The resin particles include first resin particles made of an acrylic resin having a glass transition point of 60° C. or more and 110° C. or less, second resin particles made of a polyester resin having a glass transition point of 60° C. or more and 110° C. or less, and third resin particles made of a polyolefin resin having a melting point of 110° C. or more and 150° C. or less, In the inkjet ink composition, the content of the second resin particles is 0.4 times or less the content of the first resin particles.

[0007] One aspect of the recording method according to the present invention is to A recording method using the ink set described above, The method includes a step of ejecting the ink-jet ink composition from an ink-jet head and depositing it onto a recording medium, and a step of depositing the treatment liquid onto the recording medium. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of an example of an inkjet recording apparatus. [Diagram 2]FIG. 1 is a schematic diagram of the periphery of a carriage in an example of an inkjet recording apparatus. [Diagram 3] Table 1 shows the compositions of the inks used in the examples and comparative examples. [Figure 4] Table 2 shows the compositions of the inks used in the examples and comparative examples. [Diagram 5] Table 3 shows the compositions of the inks used in the examples and comparative examples. [Figure 6] Table 4 shows the compositions of the treatment solutions used in the examples and comparative examples. [Figure 7] Table 5 shows the conditions and evaluation results of the examples and comparative examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The following describes an embodiment of the present invention. The embodiment described below is an example of the present invention. The present invention is not limited to the following embodiment, and includes various modified forms that are implemented within the scope of the present invention. Note that not all of the configurations described below are necessarily essential configurations of the present invention.

[0010] 1. Ink set The ink set according to this embodiment includes an inkjet ink composition and a treatment liquid.

[0011] 1.1. Inkjet ink composition The inkjet ink composition of the present embodiment is a water-based ink composition containing a coloring material and resin particles, and may contain a surfactant, water, an organic solvent, etc., as necessary. In this specification, the "inkjet ink composition" may be abbreviated to "ink" or the like. In this specification, the term "water-based ink" refers to an ink that contains water as a main solvent component, and the term "inkjet ink" refers to an ink that can be ejected from an inkjet head by an inkjet method and used for recording.

[0012] 1.1.1.Colorants The ink-jet ink composition contains a coloring material, which may be at least one of a pigment and a dye.

[0013] (Pigments) As the pigment, for example, inorganic pigments including carbon black and titanium white, organic pigments, etc. can be used.

[0014] As the inorganic pigment, carbon blacks (CI Pigment Black 7) such as furnace black, lamp black, acetylene black, and channel black, iron oxide, titanium oxide, zinc oxide, silica, and the like can be used.

[0015] Examples of carbon black include No. 2300, 900, MCF88, No. 20B, No. 33, No. 40, No. 45, No. 52, MA7, MA8, MA100, and No. 2200B manufactured by Mitsubishi Chemical Corporation. Examples of carbon black include Color Black FW1, FW2, FW2V, FW18, FW200, S150, S160, and S170, Pretex 35, U, V, and 140U, and Special Black 6, 5, 4A, 4, and 250 manufactured by Degussa. Examples of carbon black include Conductex SC, Raven 1255, 5750, 5250, 5000, 3500, 1255, and 700 manufactured by Columbia Carbon Corporation. Examples of such tires include Cabot Corporation's Regal 400R, 330R, 660R, Mogul L, Monarch 700, 800, 880, 900, 1000, 1100, 1300, 1400, and Elftex 12.

[0016] Examples of organic pigments include quinacridone pigments, quinacridonequinone pigments, dioxazine pigments, phthalocyanine pigments, anthrapyrimidine pigments, anthanthrone pigments, indanthrone pigments, flavanthrone pigments, perylene pigments, diketopyrrolopyrrole pigments, perinone pigments, quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, isoindolinone pigments, azomethine pigments, and azo pigments.

[0017] Specific examples of the organic pigment used in the colored ink composition include the following.

[0018] Examples of cyan pigments include CI Pigment Blue 1, 2, 3, 15:3, 15:4, 15:34, 16, 22, 60, etc.; CI Bat Blue 4, 60, etc., and preferably, one or a mixture of two or more selected from the group consisting of CI Pigment Blue 15:3, 15:4, and 60 can be exemplified.

[0019] Examples of magenta pigments include CI Pigment Red 5, 7, 12, 48(Ca), 48(Mn), 57(Ca), 57:1, 112, 122, 123, 168, 184, 202, and CI Pigment Violet 19, and preferably include one or a mixture of two or more pigments selected from the group consisting of CI Pigment Red 122, 202, and 209, and CI Pigment Violet 19. A solid solution of the above pigments may also be used.

[0020] Examples of yellow pigments include CI 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, and 185. Of these, preferred examples include one or a mixture of two or more selected from the group consisting of CI Pigment Yellow 74, 109, 110, 128, 138, 155, and 180.

[0021] Examples of orange pigments include CI Pigment Orange 36 or 43, or a mixture thereof. Examples of green pigments include CI Pigment Green 7 or 36, or a mixture thereof.

[0022] Luster pigments may also be used, and are not particularly limited as long as they can exhibit lustre when attached to a medium, but examples thereof include metal particles of one or more alloys (also called metal pigments) selected from the group consisting of aluminum, silver, gold, platinum, nickel, chromium, tin, zinc, indium, titanium, and copper, and pearl pigments having pearly luster. Representative examples of pearl pigments include pigments having pearly luster or interference luster, such as titanium dioxide-coated mica, fish scale foil, and bismuth oxychloride. Luster pigments may also be surface-treated to suppress reaction with water.

[0023] White pigments may also be used, and examples of such pigments include metal oxides, barium sulfate, calcium carbonate, and other metal compounds. Examples of metal oxides include titanium dioxide, zinc oxide, silica, alumina, magnesium oxide, and other. As the white pigment, particles having a hollow structure may also be used.

[0024] The pigments may be used alone or in combination of two or more. From the viewpoint of storage stability such as light resistance, weather resistance, and gas resistance, the pigment is preferably an organic pigment.

[0025] The volume average particle diameter (D50) of the pigment, as measured by a dynamic light scattering method, is 20 nm or more and 300 nm or less, more preferably 30 nm or more and 200 nm or less, and even more preferably 40 nm or more and 100 nm or less.

[0026] The volume average particle diameter may be measured, for example, by a Nanotrack Series particle distribution measuring device manufactured by Microtrackbell Co., Ltd. Examples of a method for adjusting the volume average particle diameter include a method for adjusting the degree of pulverization of the pigment before dispersion, a method for adjusting the stirring conditions during dispersion (e.g., stirring speed, stirring temperature, etc.), and a method for adjusting by filtration using a filter after dispersion.

[0027] The pigment may be dispersed using a pigment dispersant, or may be dispersed as a self-dispersing pigment by oxidizing or sulfonating the pigment surface with ozone, hypochlorous acid, fuming sulfuric acid, or the like.

[0028] The pigment dispersant has the function of dispersing the pigment in the colored ink composition. The pigment dispersant may be water-soluble, but is preferably not completely water-soluble, and is considered to disperse the pigment by partially or entirely bonding or adsorbing to the pigment and increasing the hydrophilicity of the pigment surface. The pigment dispersant is preferably a polymer compound, and more preferably a resin. The pigment dispersed by the pigment dispersant which is a resin is also called a resin-dispersed pigment.

[0029] Examples of the resin of the pigment dispersant include acrylic resins and salts thereof, such as poly(meth)acrylic acid, (meth)acrylic acid-acrylonitrile copolymer, (meth)acrylic acid-(meth)acrylic acid ester copolymer, vinyl acetate-(meth)acrylic acid ester copolymer, vinyl acetate-(meth)acrylic acid copolymer, vinyl naphthalene-(meth)acrylic acid copolymer, styrene-(meth)acrylic acid copolymer, styrene-(meth)acrylic acid copolymer, styrene-(meth)acrylic acid-(meth)acrylic acid ester copolymer, styrene-α-methylstyrene-(meth)acrylic acid copolymer, and styrene-α-methylstyrene-(meth)acrylic acid-(meth)acrylic acid ester copolymer. In this specification, a polymer having a skeleton derived from (meth)acrylic acid and not having a skeleton derived from maleic acid or a compound similar thereto is referred to as an acrylic resin. In this specification, "(meth)acrylic acid" means acrylic acid or methacrylic acid.

[0030] Examples of the resin for the pigment dispersant include maleic acid-based resins and salts thereof, such as styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinyl naphthalene-maleic acid copolymer, and vinyl acetate-maleic acid ester copolymer; urethane-based resins and salts thereof, which may or may not have a crosslinked structure; polyvinyl alcohols; and vinyl acetate-crotonic acid copolymers and salts thereof.

[0031] In addition to the above-mentioned polymers of acrylic monomers, the acrylic resin may be a copolymer of an acrylic monomer and another monomer. For example, an acrylic vinyl resin, which is a copolymer of a vinyl monomer as another monomer, is also called an acrylic resin. For example, among the above-mentioned styrene resins, a copolymer of a styrene monomer and an acrylic monomer is also included in the acrylic resin. Furthermore, when the acrylic resin is called an acrylic resin, its salts and esters are also included.

[0032] Examples of commercially available pigment dispersants include X-200, X-1, X-205, X-220, and X-228 (manufactured by Seiko PMC Co., Ltd.), Nopcosperse (registered trademark) 6100 and 6110 (manufactured by San Nopco Ltd.), Joncryl 67, 586, 611, 678, 680, 682, and 819 (manufactured by BASF), DISPERBYK-190 (manufactured by BYK Japan KK), N-EA137, N-EA157, N-EA167, N-EA177, N-EA197D, N-EA207D, and E-EN10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

[0033] Commercially available acrylic pigment dispersants include BYK-187, BYK-190, BYK-191, BYK-194N, and BYK-199 (manufactured by BYK-Chemie Co., Ltd.), Aron A-210, A6114, AS-1100, AS-1800, A-30SL, A-7250, and CL-2 (manufactured by Toagosei Co., Ltd.).

[0034] Commercially available urethane pigment dispersants include BYK-182, BYK-183, BYK-184, BYK-185 (manufactured by BYK-Chemie Co., Ltd.), TEGO Disperse710 (manufactured by Evonic Tego Chemi), and Borchi (registered trademark) Gen1350 (manufactured by OMG Borschers).

[0035] The pigment dispersant may be used alone or in combination of two or more. The total content of the pigment dispersant is 0.1% by mass or more and 30% by mass or less, preferably 5% by mass or more and 25% by mass or less, more preferably 10% by mass or more and 20% by mass or less, based on 100% by mass of the ink. By making the content of the pigment dispersant 0.1% by mass or more, it is possible to ensure the dispersion stability of the pigment. In addition, if the content of the pigment dispersant is 30% by mass or less, it is possible to keep the viscosity of the ink composition low.

[0036] The weight average molecular weight of the pigment dispersant is more preferably at least 500. By using such a pigment dispersant, it is possible to reduce odor and further improve the dispersion stability of the pigment.

[0037] When the pigment is dispersed by a pigment dispersant, the ratio of the pigment to the pigment dispersant is preferably from 10:1 to 1:10, and more preferably from 4:1 to 1:3.

[0038] The self-dispersing pigment refers to a pigment whose surface has been modified by directly or indirectly bonding to its surface one or more functional groups selected from the group consisting of, for example, a carbonyl group, a carboxyl group, an aldehyde group, a hydroxyl group, a sulfone group, an ammonium group, and salts thereof.

[0039] Examples of self-dispersing pigments include organic pigments such as carbon black, azo lake, insoluble azo pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, perylene pigments, perinone pigments, quinacridone pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, dioxazine pigments, anthraquinone pigments, nitro pigments, nitroso pigments, and aniline black; and inorganic pigments such as titanium white, zinc white, lead white, carbon black, red iron oxide, vermilion, cadmium red, yellow lead, ultramarine blue, cobalt blue, cobalt purple, and zinc chromate.

[0040] Of these, the self-dispersing pigment is preferably carbon black, from the viewpoints of being able to print black at a high density and being more excellent in ejection reliability.

[0041] The self-dispersing pigment may be a commercially available product or a preparation prepared by a known method, such as "Microjet CW1" and "Microjet CW2" manufactured by Orient Chemical Industry Co., Ltd., and "CAB-O-JET 200" and "CAB-O-JET 300" manufactured by Cabot Corporation.

[0042] (dye) The color ink composition may contain a dye as a coloring material. The dye is not particularly limited, and acid dyes, direct dyes, reactive dyes, basic dyes, and disperse dyes can be used.

[0043] The yellow dye is not particularly limited, but examples thereof include CI Acid Yellow 1, 3, 11, 17, 19, 23, 25, 29, 36, 38, 40, 42, 44, 49, 59, 61, 70, 72, 75, 76, 78, 79, 98, 99, 110, 111, 127, 131, 135, 142, 162, 164, and 165, and CI Direct Yellow 1, 8, 11, 12, 24, 26, 27, and 33. , 39, 44, 50, 58, 85, 86, 87, 88, 89, 98, 110, 132, 142, 144, 162, 165, CI Reactive Yellow 1, 2, 3, 4, 6, 7, 11, 12, 13, 14, 15, 16, 17, 18, 22, 23, 24, 25, 26, 27, 37, 42, CI Food Yellow 3, 4, CI Solvent Yellow 15, 19, 21, 30, 109.

[0044] Examples of magenta dyes include, but are not limited to, CI Acid Red 1, 6, 8, 9, 13, 14, 18, 26, 27, 32, 35, 37, 42, 51, 52, 57, 75, 77, 80, 82, 85, 87, 88, 89, 92, 94, 97, 106, 111, 114, 115, 117, 118, 119, 129, and 130. , 131, 133, 134, 138, 143, 145, 154, 155, 158, 168, 180, 183, 184, 186, 194, 198, 209, 211, 215, 219, 249, 252, 254, 262, 265, 274, 282, 289, 303, 317, 320, 321, 322, CI Direct Red 1, 2, 4, 9, 11, 13, 17, 20, 23, 24, 28, 31, 33, 37, 39, 44, 46, 62, 63, 75, 79, 80, 81, 83, 84, 89, 95, 99, 113, 197, 201, 218, 220, 224, 225, 226, 227, 228, 229, 230, 231, CI Reactive Red 1, 2, 3, 4, 5, 6, 7, 8, 11, 12, 13, 15, 16, 17, 19, 20, 21, 22, 23, 24, 28, 29, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 45, 46, 49, 50, 58, 59, 63, 64, CI Solubilize Red 1, and CI Food Red 7, 9, and 14.

[0045] Examples of cyan dyes include CI Acid Blue 1, 7, 9, 15, 22, 23, 25, 27, 29, 40, 41, 43, 45, 54, 59, 60, 62, 72, 74, 78, 80, 82, 83, 90, 92, 93, 100, 102, 103, 104, 112, 113, 117, 120, 126, 127, 129, 130, and 131. , 138, 140, 142, 143, 151, 154, 158, 161, 166, 167, 168, 170, 171, 182, 183, 184, 187, 192, 199, 203, 204, 205, 229, 234, 236, 249, CI Direct Blue 1, 2, 6, 15, 22, 25, 41, 71, 76, 77, 78, 80, 86 , 87, 90, 98, 106, 108, 120, 123, 158, 160, 163, 165, 168, 192, 193, 194, 195, 196, 199, 200, 201, 202, 203, 207, 225, 226, 236, 237, 246, 248, 249, CI Reactive Blue 1, 2, 3, 4, 5, 7, 8, 9, 13, 1 4, 15, 17, 18, 19, 20, 21, 25, 26, 27, 28, 29, 31, 32, 33, 34, 37, 38, 39, 40, 41, 43, 44, 46, CI Solubilize Bat Blue 1, 5, 41, CI Bat Blue 4, 29, 60, CI Food Blue 1, 2, CI Basic Blue 9, 25, 28, 29, 44.

[0046] Examples of orange dyes include Acid Orange 3, 7, 8, 10, 19, 22, 24, 33, 45, 51, 51S, 56, 67, 74, 80, 86, 87, 88, 89, 94, 95, 107, 108, 116, 122, 127, 140, 142, 144, 149, 152, 156, 162, 166, 168, and Direct Orange. Range 1, 6, 8, 10, 26, 27, 34, 39, 40, 46, 49, 102, 105, 107, 118; Reactive Orange 1, 2, 4, 5, 7, 11, 12, 13, 15, 16, 20, 30, 35, 56, 64, 67, 69, 70, 72, 74, 82, 84, 86, 87, 91, 92, 93, 95, 107.

[0047] The above dyes may be used alone or in combination of two or more.

[0048] Among these, the coloring material is preferably any one of a resin-dispersed pigment, a self-dispersed pigment, and a dye. Such coloring materials can be favorably dispersed in water-based inks, and therefore tend to have improved color development and ejection stability.

[0049] The lower limit of the content of the coloring material is not particularly limited, but is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1.0% by mass or more, and even more preferably 1.5% by mass or more, based on the total amount of the ink composition. When the content of the coloring material is within the above range, the color development tends to be more excellent.

[0050] The upper limit of the content of the coloring material is not particularly limited, but is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, even more preferably 7% by mass or less, particularly preferably 5% by mass or less, and even more particularly preferably 3% by mass or less, relative to the total amount of the ink composition. When the content of the coloring material is within the above range, the ejection stability tends to be more excellent.

[0051] 1.1.2.Resin particles The inkjet ink composition according to this embodiment contains resin particles, which include first resin particles made of an acrylic resin having a glass transition point of 60° C. or more and 110° C. or less, second resin particles made of a polyester resin having a glass transition point of 60° C. or more and 110° C. or less, and third resin particles made of a polyolefin resin having a melting point of 110° C. or more and 150° C. or less.

[0052] (1) First resin particle The first resin particles are made of an acrylic resin having a glass transition point of 60° C. or more and 110° C. or less. The glass transition point (glass transition temperature: Tg) can be confirmed by a standard method using, for example, differential scanning calorimetry (DSC). By including the first resin particles in the inkjet ink composition, the fixation of the components of the ink composition can be obtained, which can contribute to improving the abrasion resistance.

[0053] Acrylic resin is a general term for polymers obtained by polymerizing at least acrylic monomers such as (meth)acrylic acid and (meth)acrylic acid esters as one component. Examples include resins obtained from acrylic monomers and copolymers of acrylic monomers and other monomers. Examples include acrylic-vinyl resins, which are copolymers of acrylic monomers and vinyl monomers. Further examples include copolymers with vinyl monomers such as styrene (styrene-acrylic copolymers, etc.). Acrylamide, acrylonitrile, etc. can also be used as acrylic monomers.

[0054] Styrene-acrylic resins are copolymers obtained from styrene monomers and acrylic monomers, and examples thereof include styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene-methacrylic acid-acrylate copolymers, styrene-α-methylstyrene-acrylic acid copolymers, and styrene-α-methylstyrene-acrylic acid-acrylate copolymers.

[0055] For the resin emulsion made from an acrylic resin as a raw material, a commercially available product may be used, and one having a glass transition point of 60° C. or more and 110° C. or less may be selected from, for example, FK-854 (trade name, manufactured by Chuo Rika Kogyo Co., Ltd.), Mowinyl 952B, 718A (trade names, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), Nipol LX852, LX874 (trade names, manufactured by Nippon Zeon Co., Ltd.), Polysol AT860 (manufactured by Showa Denko KK), Boncoat AN-1190S, YG-651, AC-501, AN-1170, 4001 (trade names, manufactured by DIC Corporation, acrylic resin emulsions), and the like.

[0056] As the styrene-acrylic resin, commercially available products may be used, and examples thereof include JONCRYL 62J, 7100, 390, 711, 511, 7001, 631, 632, 741, 450, 840, 74J, HRC-1645J, 734, 852, 7600, 775, 537J, 1535, PDX-7630A, 352J, 352D, PDX-7145, 538J, 7640, 7641, 631, 790, 780, 7610 (product names, manufactured by BASF), Mowinyl 966A, 975N, 6800 (product names, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), and the like. Among these, those having a glass transition point of 60°C or more and 110°C or less are selected and used.

[0057] The glass transition point of the acrylic resin of the first resin particles is from 60° C. to 110° C., more preferably from 65° C. to 105° C., and even more preferably from 70° C. to 100° C. When the glass transition point of the acrylic resin of the first resin particles is 60° C. or higher, sufficiently good clogging recovery properties can be obtained, and when it is 110° C. or lower, sufficient fixation of the image to the recording medium can be obtained.

[0058] Furthermore, the glass transition point of the acrylic resin of the first resin particles is preferably higher than the glass transition point of the polyester resin of the second resin particles, more preferably by at least 5° C., and even more preferably by at least 10° C. In this way, when an image is fixed on a recording medium, the fixability of the image by the acrylic resin is more easily improved.

[0059] (2) Second resin particles The first resin particles are made of a polyester resin having a glass transition point of 60° C. or more and 110° C. or less. By including the second resin particles in the inkjet ink composition, the adhesion of the image is improved, which can contribute to improving the abrasion resistance.

[0060] The polyester resin is not particularly limited, but examples thereof include polymers containing ester bonds in the main chain, such as polymers obtained by condensation polymerization of divalent organic acids and divalent organic alcohols, or compounds having carboxyl groups and hydroxyl groups. These monomer units may be mixed and copolymerized appropriately. More specifically, examples thereof include polyethylene terephthalate, polyethylene adipate, polybutylene succinate, polybutylene lactate, and polylactic acid. As the polyester resin, commercially available products may be used, such as Elitel KT8701, KT8803 (trade names, manufactured by Unitika Ltd.), and Pyronal MD-2000 (trade name, manufactured by Toyobo Co., Ltd.), and among these, polyester resins having a glass transition point of 60°C or more and 110°C or less are selected and used.

[0061] The glass transition point of the polyester resin of the second resin particles is from 60° C. to 110° C., more preferably from 65° C. to 105° C., and even more preferably from 70° C. to 100° C. When the glass transition point of the polyester resin of the second resin particles is 60° C. or higher, sufficiently good clogging recovery properties can be obtained, and when it is 110° C. or lower, sufficient adhesion of the image to the recording medium can be obtained.

[0062] The glass transition point of the polyester resin of the second resin particles is preferably lower than the glass transition point of the acrylic resin of the first resin particles, more preferably by 5° C. or more, and even more preferably by 10° C. or more. In this way, when an image is fixed on a recording medium, the adhesion of the image due to the polyester resin can be more easily improved.

[0063] (3) Third resin particles The third resin particles are made of a polyolefin resin having a melting point of 110° C. or more and 150° C. or less. By including the third resin particles in the inkjet ink composition, the slipperiness of the entire printed surface is improved, which can contribute to improving the abrasion resistance. In addition, the third resin particles have a function of imparting lubricity to an image formed by the inkjet ink composition adhered to a recording medium, for example.

[0064] Examples of polyolefin resins include resins produced from olefins such as ethylene, propylene, and butylene, or derivatives thereof, specifically, polyethylene resins, polypropylene resins, and polybutylene resins.

[0065] Commercially available polyolefin resins include, for example, AQUACER513 (polyethylene resin, average particle size 100 nm to 200 nm, melting point 130° C., solid content 30%), AQUACER series such as AQUACER507, AQUACER515, AQUACER840, and AQUACER1547, HORDAMER PE Examples of the Hi-Tech series include Hi-Tech E-7025P, Hi-Tech E-2213, Hi-Tech E-6500, Hi-Tech E-6314, Hi-Tech E-6400, Hi-Tech E-9460, Hi-Tech E-9015, Hi-Tech E-4A, Hi-Tech E-5403P, Hi-Tech E-8010, and Hi-Tech E-8237 (all trade names, manufactured by Toho Chemical Industry Co., Ltd., polyethylene resins), and Nopcoat PEM-17 (trade name, manufactured by San Nopco Ltd., polyethylene emulsion, average particle size 40 nm).

[0066] The melting point Tm of the third resin particles in the inkjet ink composition is 110° C. or more and 150° C. or less, more preferably 115° C. or more and 145° C. or less, and even more preferably 120° C. or more and 140° C. or less. When the melting point Tm of the third resin particles in the inkjet ink composition is within the above range, the abrasion resistance tends to be more excellent. The melting point can be confirmed by a standard method using, for example, differential scanning calorimetry (DSC) or the like.

[0067] Polyolefin resins often have a smaller specific gravity than acrylic resins and polyester resins. Therefore, since the third resin particles are made of polyolefin resins, when an image is fixed on a recording medium, the polyolefin resin is likely to be concentrated on the surface side of the image. In other words, when an image is fixed, the polyolefin resin is likely to be fixed on the side farther from the recording medium in the thickness direction of the recording medium than the acrylic resin, and the abrasion resistance of the image is likely to be improved.

[0068] (4) Ratio and content of resin particles In the inkjet ink composition of this embodiment, the content of the second resin particles is 0.4 times or less the content of the first resin particles, so that when an image is fixed, the thickness of the layer containing a large amount of the first resin particles, which are mainly responsible for fixation, is relatively thicker than the thickness of the layer containing a large amount of the second resin particles, which are mainly responsible for adhesion, and the balance of the functions of fixing and adhering the image is good, so that the abrasion resistance of the image can be made good.

[0069] In addition, since the content of the second resin particles is 0.4 times or less than the content of the first resin particles, the thickness of the layer containing a large amount of the first resin particles is relatively thick, and the smoothness of the surface of the image is improved, and the smoothness of the layer containing a large amount of the third resin particles is also improved, and the image can exhibit good abrasion resistance.

[0070] From this viewpoint, the content of the second resin particles is preferably 0.35 times or less, more preferably 0.3 times or less, and even more preferably 0.25 times or less, the content of the first resin particles, while the content of the second resin particles is preferably 0.05 times or more, and more preferably 0.07 times or more, the content of the first resin particles.

[0071] The content of the first resin particles in the inkjet ink composition is preferably 1% by mass or more and 10% by mass or less, more preferably 2% by mass or more and 9% by mass or less, even more preferably 3% by mass or more and 8% by mass or less, and especially preferably 4.5% by mass or more and 7.5% by mass or less, relative to the total amount of the inkjet ink composition.

[0072] The content of the second resin particles in the inkjet ink composition is preferably from 0.1% to 2% by mass, and more preferably from 0.5% to 1.5% by mass, based on the total amount of the inkjet ink composition.

[0073] The content of the third resin particles in the inkjet ink composition is preferably from 0.1% to 2% by mass, and more preferably from 0.5% to 1.5% by mass, based on the total amount of the inkjet ink composition.

[0074] Furthermore, the total content of the first resin particles, the second resin particles and the third resin particles in the inkjet ink composition is preferably 3% by mass or more and 12% by mass or less, more preferably 3% by mass or more and 12% by mass or less, more preferably 4% by mass or more and 10% by mass or less, and even more preferably 5% by mass or more and 9% by mass or less, relative to the total amount of the inkjet ink composition.

[0075] (5) Cohesiveness of resin particles In the inkjet ink composition of this embodiment, when a 5% by mass aqueous medium solution of resin particles is mixed with a 5% by mass aqueous solution of calcium propionate, the thickening rate of the second resin particles is preferably greater than that of the first resin particles. In other words, the reactivity of the second resin particles with the aggregating agent is preferably greater than that of the first resin particles. In this case, the second resin particles made of polyester resin are more likely to move toward the recording medium, so that the adhesion of the image is further improved and the abrasion resistance can be further improved.

[0076] 1.1.3.Water The inkjet ink composition according to this embodiment is a water-based ink, and is a composition in which water is one of the main solvents.

[0077] The water is not particularly limited, but examples thereof include pure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, and distilled water, as well as ultrapure water from which ionic impurities have been removed as much as possible. Furthermore, by using water sterilized by ultraviolet irradiation or the addition of hydrogen peroxide, the generation of mold and bacteria can be prevented when the water-based ink composition is stored for a long period of time. This tends to further improve storage stability.

[0078] The water content is preferably 40% by mass or more, more 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, further 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 even more preferably 65% ​​by mass or more and 75% by mass or less, based on the total amount of the ink composition.

[0079] 1.1.4.Water-soluble low molecular weight organic compounds The inkjet ink composition may contain a water-soluble low molecular weight compound. The water-soluble low molecular weight compound in this section does not include coloring materials, polyvalent metal salts, organic acids, and organic amines. The water-soluble low molecular weight compound is mainly an organic solvent or a solid compound.

[0080] "Water-soluble" means that the solubility in 100 g of water at 20°C is more than 10 g. Examples of the water-soluble low molecular weight compound include those that are liquid at room temperature and those that are solid at room temperature. By including a water-soluble low molecular weight compound in the ink composition, the clogging recovery property, storage stability, image quality, etc. of the ink composition can be improved.

[0081] The method for determining the solubility of a water-soluble low molecular weight compound is as follows. First, in an environment of 20°C, a predetermined amount of the water-soluble low molecular weight compound is mixed with 100 g of water and stirred for 30 minutes. After stirring, if the compound is liquid at room temperature and there is no phase separation or sea-island structure, it is judged to be soluble. Also, if the compound is solid at room temperature and there is no residual residue, it is judged to be soluble.

[0082] In this way, when a predetermined amount of a compound is mixed with 100 g of water, the largest amount among the predetermined amounts that are determined to be dissolved is taken as the solubility. A compound with a solubility of more than 10 g is taken as a water-soluble low molecular weight compound. The water-soluble low molecular weight compound may be a compound that is completely miscible with water or a compound that is miscible with water.

[0083] In this specification, "completely miscible with water" refers to the case where water and a compound are mutually soluble, that is, the solubility of the compound in 100 g of water at 20°C is infinite. Also, "miscible with water" refers to the case where water and a compound have a finite solubility, and refers to the case where the solubility of the compound in 100 g of water at 20°C is at least more than 10 g. The solubility of water-soluble low molecular weight compounds is The solubility is more than 10 g, but the upper limit is not limited and may be infinite. The solubility is preferably 11 g or more, more preferably 50 g or more.

[0084] The molecular weight of the water-soluble low molecular weight compound is preferably 500 or less in terms of weight average molecular weight. Furthermore, 400 or less is more preferable, and 300 or less is even more preferable. Furthermore, the ink composition preferably contains, as the water-soluble low molecular weight compound, a compound having a standard boiling point of 150°C or more and 350°C or less, preferably 150°C or more and 300°C or less. Furthermore, the water-soluble low molecular weight compound preferably contains a compound having a melting point of 90°C or less. Furthermore, it is preferable to contain a compound having a melting point of 80°C or less. Furthermore, the melting point is preferably -70°C or more.

[0085] Examples of water-soluble low molecular weight compounds having a solubility of more than 10 g in 100 g of water at 20° C. include resin-dissolving substances, polyols, glycol ethers, etc. Examples of resin-dissolving substances include amides, sulfur-containing solvents, cyclic ethers, etc. Among these, resin-dissolving substances, polyols, and glycol ethers are preferred.

[0086] More preferred examples of the water-soluble low molecular weight compound include amides, sulfur-containing solvents, and cyclic ethers having a standard boiling point of 150°C or higher and 300°C or lower, and polyols and glycol ethers having a standard boiling point of 150°C or higher and 250°C or lower.

[0087] The water-soluble low molecular weight compound is contained in an amount of preferably 40 mass % or less, more preferably 1 mass % or more, even more preferably 5 mass % or more and 30 mass % or less, and even more preferably 10 mass % or more and 25 mass % or less, relative to the total mass of the ink composition.

[0088] <Resin dissolved substances> Examples of water-soluble low molecular weight compounds having a solubility of more than 10 g in 100 g of water at 20°C include resin-dissolving substances that are either amides, sulfur-containing solvents, or cyclic ethers. Among these, it is preferable to contain a resin-dissolving substance that is either amides, sulfur-containing solvents, or cyclic ethers having a standard boiling point of 150°C or more and 300°C or less. The resin-dissolving substance is an organic compound that has the function of dissolving resin and improving abrasion resistance, but is not limited to this function.

[0089] Examples of the amides include cyclic amides (lactams) such as 2-pyrrolidone (2P), 2-piperidone, ε-caprolactam (CPL), N-methyl-ε-caprolactam, N-cyclohexyl-2-pyrrolidone, N-methylpyrrolidone, N-ethylpyrrolidone, N-butylpyrrolidone, 5-methyl-2-pyrrolidone, β-propiolactam, and ω-heptalactam; N,N-dimethylacetoacetamide, N,N-diethylacetoacetamide, and N-methyl Acetoacetamide, N,N-dimethylisobutyric acid amide, N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylpropionamide, 3-methoxy-N,N-dimethylpropanamide (DMPA), 3-n-butoxy-N,N-dimethylpropionamide, 3-methoxy-N,N-diethylpropionamide, 3-methoxy-N,N-methylethylpropionamide Amide, 3-ethoxy-N,N-dimethylpropionamide, 3-ethoxy-N,N-diethylpropionamide, 3-ethoxy-N,N-methylethylpropionamide, 3-n-butoxy-N,N-diethylpropionamide, 3-n-butoxy-N,N-methylethylpropionamide, 3-n-propoxy-N,N-dimethylpropionamide, 3-n-propoxy-N,N-diethylpropionamide, 3-n-propoxy-N,N-methyl Examples of the chain amides include ethylpropionamide, 3-iso-propoxy-N,N-dimethylpropionamide, 3-iso-propoxy-N,N-diethylpropionamide, 3-iso-propoxy-N,N-methylethylpropionamide, 3-tert-butoxy-N,N-dimethylpropionamide, 3-tert-butoxy-N,N-diethylpropionamide, and 3-tert-butoxy-N,N-methylethylpropionamide. Among these, 2-pyrrolidone (2P), ε-caprolactam (CPL), and 3-methoxy-N,N-dimethylpropanamide (DMPA) are more preferable, and tend to provide the ink with better storage stability.

[0090] Examples of the sulfur-containing solvent include 3-methylsulfolane, sulfolane, ethyl isopropyl sulfone, ethyl methyl sulfone, dimethyl sulfone, dimethyl sulfoxide (DMSO), diethyl sulfoxide, tetramethylene sulfoxide, methyl phenyl sulfoxide, etc. Among these, dimethyl sulfoxide (DMSO) is more preferable, and tends to provide the ink with better storage stability.

[0091] Examples of the cyclic ethers include isosorbide dimethyl ether, 3-methyl-3-oxetanemethanol, 3-ethyl-3-oxetanemethanol (DMHD), 2-hydroxymethyloxetane, tetrahydrofurfuryl alcohol, solketal, glycerol formal, 1,4-dioxane-2,3-diol, dihydrolevoglucosenone, etc. Among these, 3-ethyl-3-oxetanemethanol (DMHD) is more preferable, and tends to provide better storage stability for the ink.

[0092] Among these, amide resin-dissolving substances having a normal boiling point of 150° C. or more and 300° C. or less are preferred because they tend to have better storage stability. Also, the resin-dissolving substance is preferably a compound having a melting point of 80° C. or less. If the melting point is within the above range, clogging recovery properties tend to be excellent.

[0093] The ink composition preferably contains 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, and particularly preferably 5% by mass or less of a resin-dissolving substance, which is any one of amides, sulfur-containing solvents, and cyclic ethers, as a water-soluble low molecular weight compound, relative to the total mass of the ink composition. The lower limit is 0% by mass or more, preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more.

[0094] In addition, the content of the resin-dissolving substance, which is any one of amides, sulfur-containing solvents, and cyclic ethers having a normal boiling point of 150°C or more and 300°C or less, may be within the above range. When the content of these resin-dissolving substances is within the above range, the solubility of the resin in the ink composition becomes good, and the storage stability and abrasion resistance tend to be excellent. On the other hand, when the content of these resin-dissolving substances exceeds the above range, the storage stability may decrease. This is presumably because the resin becomes more easily dissolved due to the relative decrease in the content of water in the ink composition.

[0095] <Polyols, glycol ethers> The ink composition may contain, as a water-soluble low molecular weight compound other than the resin-dissolving substance, any of polyols and glycol ethers, and in particular, it is preferable that the ink composition contains any of polyols and glycol ethers having a normal boiling point of 150° C. or more and 250° C. or less.

[0096] (Polyols) The polyol is preferably a glycol or a compound in which glycol is intermolecularly condensed with its hydroxyl groups. In this case, the compound has two hydroxyl groups. Alternatively, the polyol may be a compound in which the hydrogen atom of a glycol or a compound in which glycol is intermolecularly condensed with its hydroxyl groups is replaced with a hydroxyl group. In this case, the compound has three or more hydroxyl groups.

[0097] The glycol unit in the glycol constituting the polyol or in the compound in which glycols are intermolecularly condensed between hydroxyl groups preferably has 2 to 10 carbon atoms, more preferably 3 to 8 carbon atoms. The polyol preferably has 2 to 15 carbon atoms, more preferably 3 to 10 carbon atoms. The polyol preferably has a normal boiling point of 150°C to 250°C.

[0098] Examples of the polyols having a standard boiling point of 150° C. or more and 250° C. or less include ethylene glycol (standard boiling point 198° C., miscible with water), diethylene glycol (standard boiling point 244° C., completely miscible with water), 1,2-propanediol (propylene glycol) (standard boiling point 188° C., completely miscible with water), dipropylene glycol (standard boiling point 227° C., completely miscible with water), 1,2-but ... dipropylene glycol (standard boiling point 227° C., completely miscible with water), dipropylene glycol (standard boiling point 227° C., completely miscible with water), dipropylene glycol (standard boiling point 227° C., completely miscible with water), dipropylene glycol (standard boiling point 227° C., completely miscible with water), dipropylene glycol (standard boiling point 227° C., completely miscible with water), dipropylene glycol (standard boiling point 227° C., completely miscible with water), dipropylene glycol (standard boiling point 227° C. 1,2-pentanediol (standard boiling point 193°C, miscible with water), 1,2-hexanediol (standard boiling point 210°C, miscible with water), 1,2-hexanediol (standard boiling point 224°C, completely miscible with water), 1,3-propanediol (standard boiling point 214°C, completely miscible with water), 1,4-butanediol (standard boiling point 228°C, completely miscible with water), 2,3-butanediol (standard boiling point 177°C, miscible with water), 1 ,3-Butylene glycol (standard boiling point 207°C, completely miscible with water), 3-methyl-1,3-butanediol (standard boiling point 203°C, completely miscible with water), 2-methyl-1,3-propanediol (standard boiling point 214°C, completely miscible with water), 2,2-dimethyl-1,3-propanediol (standard boiling point 208°C, solubility 83 [g / 100g water]), 2-methylpentane-2,4-diol (standard boiling point 197°C, completely miscible with water), 2,5-dimethyl-2,5-hexanediol (standard boiling point 218°C, solubility 14 [g / 100g water]), 1,5-pentanediol (standard boiling point 242°C, miscible with water), 3-methyl-1,5-pentanediol (standard boiling point 250°C, completely miscible with water), 1,6-hexanediol (standard boiling point 250°C, miscible with water), etc. As the polyol, polyols having 10 or less carbon atoms are more preferable.

[0099] Among the polyols, alkanediols having a standard boiling point of 150° C. or more and 250° C. or less and a carbon number of 10 or less are more preferable, and alkanediols having a standard boiling point of 150° C. or more and 250° C. or less and a carbon number of 6 or less are even more preferable. Examples of such alkanediols include 1,2-alkanediols such as ethylene glycol, propylene glycol, 1,2-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,3-propanediol, 1,3-butylene glycol, etc.

[0100] The ink composition preferably contains, as a water-soluble low molecular weight compound, alkanediols having a normal boiling point of 150° C. or more and 250° C. or less and a carbon number of 6 or less in an amount of 1% by mass to 5% by mass relative to the total mass of the ink composition.

[0101] (Glycol ethers) Glycol ethers are compounds in which one or more hydroxyl groups of glycol are etherified. The glycol ethers are preferably monoethers or diethers of alkylene glycols. The etherified ethers are preferably alkyl ethers. The alkylene of the alkylene glycol and the alkyl of the alkyl ether, which constitute the glycol ethers, each preferably have 1 to 5 carbon atoms, more preferably 2 to 4 carbon atoms. The glycol ethers also preferably have a standard boiling point of 150°C to 250°C.

[0102] Examples of glycol ethers include ethylene glycol monomethyl ether (completely miscible with water), ethylene glycol monoethyl ether (miscible with water), ethylene glycol monoisopropyl ether (solubility 100 [g / 100g water]), ethylene glycol monopropyl ether (miscible with water), ethylene glycol monoisobutyl ether (solubility 75.5 [g / 100g water]), ethylene glycol mono-tert-butyl ether (miscible with water), ethylene glycol monobutyl ether (solubility 100 [g / 100g water]), diethylene glycol Lithylene glycol monomethyl ether (completely miscible with water), diethylene glycol monoethyl ether (completely miscible with water), diethylene glycol monoisopropyl ether (completely miscible with water), diethylene glycol monoisobutyl ether (completely miscible with water), diethylene glycol monobutyl ether (completely miscible with water), triethylene glycol monomethyl ether (completely miscible with water), triethylene glycol monoethyl ether (completely miscible with water), triethylene glycol monobutyl ether (miscible with water), tetraethylene glycol monomethyl ether (completely miscible with water) Miscible with water), propylene glycol monomethyl ether (miscible with water), propylene glycol monoethyl ether (completely miscible with water), propylene glycol monopropyl ether (miscible with water), dipropylene glycol monomethyl ether (completely miscible with water), dipropylene glycol monopropyl ether (solubility 19 [g / 100g water]), tripropylene glycol monomethyl ether (completely miscible with water), 1,3-propanediol monomethyl ether (3-methoxy-1-propanol) (completely miscible with water), 1,3-butylene glycol-3-monomer Alkylene glycol monoalkyl ethers such as ethyl ether (3-methoxy-1-butanol) (miscible with water), and ethylene glycol dimethyl ether (completely miscible with water), diethylene glycol dimethyl ether (completely miscible with water), diethylene glycol methyl ethyl ether (completely miscible with water), diethylene glycol diethyl ether (completely miscible with water), triethylene glycol dimethyl ether (completely miscible with water), tetraethylene glycol dimethyl ether (completely miscible with water), dipropylene glycol dimethyl ether (solubility 52.Examples of alkylene glycol dialkyl ethers (glymes) include alkylene glycol dimethyl ether (solubility 23.6 [g / 100 g water]) and tripropylene glycol dimethyl ether (solubility 23.6 [g / 100 g water]).

[0103] In addition, among the glycol ethers, diethers tend to dissolve or swell the resin in the ink composition more easily than monoethers, and are therefore more preferred in terms of improving the abrasion resistance of the formed image, whereas monoethers are preferred in terms of providing excellent storage stability to the ink composition.

[0104] The ink composition contains, as a water-soluble low molecular weight compound, either polyols or glycol ethers, in an amount of preferably 30% by mass or less, more preferably 25% by mass or less, based on the total mass of the ink composition, and the lower limit is 0% by mass or more, preferably 10% by mass or more, more preferably 15% by mass or more, based on the total mass of the ink composition.

[0105] It is also preferable that the content of either the polyols or the glycol ethers having a normal boiling point of 150° C. or more and 250° C. or less is within the above range.

[0106] When the water-soluble low molecular weight compound is contained within the above range, the ink tends to have better moisture retention and better storage stability.

[0107] When the inkjet ink composition contains a water-soluble low-molecular-weight organic compound, the total content of the water-soluble low-molecular-weight organic compound is preferably from 10% by mass to 30% by mass, more preferably from 14% by mass to 27% by mass, and even more preferably from 15% by mass to 25% by mass, relative to the total amount of the inkjet ink composition.

[0108] In addition, of the total content of water-soluble low molecular weight organic compounds, the content of water-soluble low molecular weight organic compounds having a normal boiling point of 210°C or less preferably accounts for 60 mass% or more, more preferably 70 mass% or more, and even more preferably 80 mass% or more.

[0109] 1.1.5.Other Ingredients (1) Surfactants The inkjet ink composition may contain a surfactant. The surfactant is not particularly limited, but examples thereof include acetylene glycol-based surfactants, fluorine-based surfactants, and silicone-based surfactants.

[0110] The acetylene glycol surfactant is not particularly limited, but examples thereof include Surfynol 104, 104E, 104H, 104A, 104BC, 104DPM, and 104PA. , 104PG-50, 104S, 420, 440, 465, 485, SE, SE-F, 504, 61, DF37, CT111, CT121, CT131, CT136, TG, GA, DF110D (all trade names, manufactured by Air Products Japan Co., Ltd.), Olfine B, Y, P, A, STG, SPC, E1004, E1010, PD-001, PD-002W, PD-003, PD-004, EXP.4001, EXP.4036, EXP.4051, AF-103, AF-104, AK-02, SK-14, AE-3 (all trade names, manufactured by Nissin Chemical Industry Co., Ltd.), Acetylenol E00, E00P, E40, E100 (all trade names, manufactured by Kawaken Fine Chemical Co., Ltd.).

[0111] As the fluorosurfactant, it is preferable to use a fluorine-modified polymer, and a specific example thereof is BYK-340 (product name, manufactured by BYK Japan KK).

[0112] The silicone surfactant is not particularly limited, but a polysiloxane compound is preferred. The polysiloxane compound is not particularly limited, but an example thereof is polyether-modified organosiloxane. Examples of commercially available polyether-modified organosiloxanes include BYK-306, BYK-307, BYK-333, BYK-341, BYK-345, BYK-346, BYK-348 (all trade names, manufactured by BYK Japan Co., Ltd.), KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640, KF-642, KF-643, KF-6020, X-22-4515, KF-6011, KF-6012, KF-6015, KF-6017 (all trade names, manufactured by Shin-Etsu Chemical Co., Ltd.), Silface SAG503A, Silface SAG014 (all trade names, manufactured by Nissin Chemical Industry Co., Ltd.), and the like.

[0113] The above surfactants may be used alone or in combination of two or more kinds.

[0114] When a surfactant is contained, its content is preferably from 0.1% by mass to 1.5% by mass relative to the total mass of the ink composition.

[0115] It is also good and preferable that the content of the silicone surfactant or the fluorine surfactant among the above surfactants is within the above range.It is also good and preferable that the content of the silicone surfactant among the above surfactants is within the above range.

[0116] Generally, by adding a silicone surfactant to an ink composition, image quality tends to be improved, but the abrasion resistance and defoaming properties tend to be deteriorated. However, in the ink composition of the present embodiment, even if a small amount is added within the above range, the image quality is excellent and the abrasion resistance is also good.

[0117] (2) Resin The inkjet ink composition may contain a resin other than the above-mentioned resin particles. The resin may be blended as a water-soluble resin or an emulsion of resin particles other than those described above. Such a resin may function as a fixing resin that improves the adhesion and abrasion resistance of the ink components attached to the recording medium. (3) Other substances The ink-jet ink composition may contain various additives, such as a chelating agent, an anti-rust agent, an anti-fungal agent, an antioxidant, an anti-reducing agent, and an evaporation promoter, as necessary.

[0118] 1.1.6. Preparation and properties of ink-jet ink composition The inkjet ink composition can be obtained by mixing the above-mentioned components in any order and removing impurities by filtration, etc., as necessary. As a method for mixing each component, a method in which materials are added in order to a container equipped with a stirring device such as a mechanical stirrer or a magnetic stirrer and stirred and mixed is preferably used. As a filtration method, centrifugal filtration, filter filtration, etc. can be performed as necessary.

[0119] From the viewpoint of a balance between image quality and reliability as an ink for inkjet recording, the inkjet ink composition preferably has a surface tension (static surface tension) of 18 mN / m to 40 mN / m at 20° C., more preferably 20 mN / m to 35 mN / m, and even more preferably 22 mN / m to 33 mN / m. The surface tension can be measured, for example, by using an automatic surface tensiometer CBVP-Z (product name, manufactured by Kyowa Interface Science Co., Ltd.) to confirm the surface tension when a platinum plate is wetted with the ink in an environment of 20° C.

[0120] From the same viewpoint, the viscosity of the inkjet ink composition at 20° C. is preferably from 3 mPa·s to 10 mPa·s, and more preferably from 3 mPa·s to 8 mPa·s. The viscosity can be measured, for example, using a viscoelasticity tester MCR-300 (product name, manufactured by Pysica) in an environment of 20° C.

[0121] The inkjet ink composition is subjected to the action of aggregation of the components and thickening of the composition by the aggregating agent contained in the treatment liquid described later. The viscosity of the inkjet ink composition is preferably increased by the treatment liquid described later. The degree of increase in viscosity in this case is not particularly limited, but the viscosity increase rate of the ink composition when the inkjet ink composition and the treatment liquid described later are mixed at a mass ratio (ink composition:treatment liquid)=(10:1) is preferably 2.0 times or more, more preferably 2.5 times or more, even more preferably 4.0 times or more, and particularly preferably 5.5 times or more. The upper limit of the viscosity increase rate is not particularly limited, but is preferably 10 times or less, more preferably 8 times or less. When the viscosity increase rate is within such a range, an image with even better image quality can be obtained.

[0122] 1.2. Processing solution The treatment liquid contains a flocculant.

[0123] Flocculants The treatment liquid contains an aggregating agent that aggregates the components of the inkjet ink composition. The aggregating agent also has the effect of increasing the viscosity of the inkjet ink composition. When the treatment liquid contains an aggregating agent, the aggregating agent reacts with the coloring material, resin, and the like contained in the inkjet ink composition on the recording medium when the treatment liquid and the inkjet ink composition are applied to a recording medium. This causes the coloring material and resin in the inkjet ink composition to be destroyed in their dispersed state and aggregate, increasing the viscosity of the inkjet ink composition, and the image quality of the resulting image is improved (reduced bleed unevenness and improved color development).

[0124] Examples of the flocculant include cationic compounds such as polyvalent metal salts, cationic resins, and cationic surfactants, and organic acids. These flocculants may be used alone or in combination of two or more. Among these flocculants, it is preferable to use at least one flocculant selected from the group consisting of polyvalent metal salts, organic acids, and cationic resins, because they have excellent reactivity with the components contained in the ink composition.

[0125] Polyvalent metal salts are compounds that are composed of divalent or higher polyvalent metal ions and anions that bind to these polyvalent metal ions, and are soluble in water. Specific examples of polyvalent metal ions include Ca 2+ , Cu 2+ , Ni 2+ , Mg 2+ , Zn 2+ , B.A. 2+ Divalent metal ions such as Al 3+ , Fe 3+ , Cr 3+ Examples of trivalent metal ions include Cl. - , I - , Br - , S.O. 4 2- , ClO 3- , NO 3- , and H.C.O.O. - , C.H. 3 COO - Among these polyvalent metal salts, calcium salts and magnesium salts are preferred from the viewpoints of the stability of the treatment liquid and the reactivity as a flocculant.

[0126] Suitable examples of organic acids include poly(meth)acrylic acid, formic acid, acetic acid, propionic acid, glycolic acid, oxalic acid, malonic acid, malic acid, maleic acid, ascorbic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, citric acid, tartaric acid, lactic acid, pyruvic acid, pyrrolidone carboxylic acid, pyrone carboxylic acid, pyrrole carboxylic acid, furan carboxylic acid, pyridine carboxylic acid, coumaric acid, thiophene carboxylic acid, nicotinic acid, or derivatives of these compounds, or salts thereof. Organic acids may be used alone or in combination of two or more. Organic acid salts that are also polyvalent metal salts are included in polyvalent metal salts.

[0127] Examples of cationic resins include cationic urethane resins, cationic olefin resins, and cationic amine resins. The cationic amine resins may be any resin having an amino group, and examples thereof include allylamine resins, polyamine resins, quaternary ammonium salt polymers, and polyamide resins. Examples of polyamine resins include those having an amino group in the main skeleton of the resin. Examples of allylamine resins include those having a structure derived from an allyl group in the main skeleton of the resin. Examples of quaternary ammonium salt polymers include resins having a quaternary ammonium salt in the structure. Examples of polyamide resins include those having an amide group in the main skeleton of the resin and an amino group in the side chain of the resin. Among cationic resins, cationic amine resins are preferred because they are not only highly reactive but also easily available.

[0128] Among the above-mentioned examples, the flocculant is more preferably selected from polyvalent metal salts, cationic resins and organic acids, which allows the production of images with better adhesion.

[0129] The concentration of the flocculant in the treatment liquid is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 3% by mass or more, based on the total mass of the treatment liquid, and is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, based on the total mass of the treatment liquid.

[0130] 1.2.2.Other Ingredients The treatment liquid may contain water, a water-soluble low molecular weight organic compound, a surfactant, other additives, etc., as components other than the aggregating agent. The contents of these components and the contents of the treatment liquid are the same as those of the inkjet ink composition described above, and therefore will not be described here. In addition to containing the aggregating agent, the treatment liquid may contain components other than the coloring material of the inkjet ink composition described above, and the contents and properties of these components may be set independently of the inkjet ink composition described above. In addition, the treatment liquid has a content of the coloring material of 0.2% by mass or less, preferably 0.1% by mass or less, more preferably 0.05% by mass or less, with the lower limit being 0% by mass.

[0131] 1.2.3. Preparation and properties of processing solution The treatment liquid according to the present embodiment can be produced by dispersing and mixing the above-mentioned components by an appropriate method. After thoroughly stirring the above-mentioned components, the desired treatment liquid can be obtained by filtering to remove coarse particles and foreign matter that may cause clogging.

[0132] When the treatment liquid according to the present embodiment is discharged from an inkjet head, the surface tension at 25° C. is preferably 18 mN / m to 40 mN / m, more preferably 20 mN / m to 35 mN / m, and even more preferably 22 mN / m to 33 mN / m. The surface tension can be measured, for example, by using an automatic surface tensiometer CBVP-Z (product name, manufactured by Kyowa Interface Science Co., Ltd.) to confirm the surface tension when a platinum plate is wetted with the treatment liquid in an environment of 25° C.

[0133] From the same viewpoint, the viscosity of the treatment liquid at 25° C. is preferably 3 mPa·s or more and 10 mPa·s or less, and more preferably 3 mPa·s or more and 8 mPa·s or less. The viscosity can be measured, for example, using a viscoelasticity tester MCR-300 (product name, manufactured by Pysica) in an environment of 25° C.

[0134] 1.3. Effects, etc. According to the ink set of this embodiment, the inkjet ink composition contains first resin particles made of acrylic resin and second resin particles made of polyester resin, the content of the second resin particles being 0.4 times or less the content of the first resin particles, and further contains third resin particles made of polyolefin resin with a predetermined melting point range, thereby obtaining an image with good abrasion resistance. Furthermore, the inkjet ink composition contains first resin particles and second resin particles with a predetermined glass transition point range, thereby improving the clogging recovery of the inkjet head.

[0135] In addition, when the ink set of this embodiment is used for recording on a recording medium (described later) that is a low-absorbency recording medium or a non-absorbency recording medium and has a non-coated polyester surface, the effect of improving adhesion by the second resin particles is particularly remarkable.

[0136] 2. Recording method The recording method according to this embodiment is a recording method carried out using the ink set described above, and includes a step of ejecting an inkjet ink composition from an inkjet head and depositing it onto a recording medium, and a step of depositing a treatment liquid onto the recording medium.

[0137] 2.1. Recording medium The recording medium on which an image is formed by the recording method according to this embodiment may have a recording surface that absorbs liquid such as an ink composition, or may not have a recording surface that absorbs liquid.Therefore, the recording medium is not particularly limited, and examples thereof include liquid-absorbent recording media such as paper and cloth, low-absorbent recording media such as printed paper, and liquid-non-absorbent recording media such as metal, glass, film, and polymer.However, the excellent effect of the recording method according to this embodiment is more pronounced when an image is recorded on a recording medium that is low-absorbent or non-absorbent.That is, according to the recording method according to this embodiment, even if the low-absorbent recording medium or non-absorbent recording medium is relatively prone to aggregation unevenness, an image with high image quality and good abrasion resistance can be formed.

[0138] A recording medium with low liquid absorption or no liquid absorption refers to a recording medium that does not absorb liquid at all or absorbs very little liquid. Quantitatively, a recording medium with low liquid absorption or no liquid absorption is one that is "non-absorbent within 30 msec from the start of contact in the Bristow method." 1 / 2 Water absorption up to 10mL / m 2 The Bristow method refers to a recording medium that is 1 or below the standard. The Bristow method is the most widely used method for measuring the amount of liquid absorbed in a short time, and is also adopted by the Japan Pulp and Paper Technical Association (JAPAN TAPPI). Details of the test method are described in Standard No. 51 "Paper and Paperboard - Liquid Absorbency Test Method - Bristow Method" of the "JAPAN TAPPI Paper Pulp Test Method 2000 Edition." In contrast, a liquid-absorbent recording medium refers to a recording medium that does not fall under the category of non-absorbent or low-absorbent. In this specification, low-absorbent and non-absorbent may be simply referred to as low-absorbent and non-absorbent.

[0139] Examples of liquid non-absorbent recording media include films and plates of plastics such as polyvinyl chloride, polyethylene, polypropylene, and polyethylene terephthalate (PET), metal plates such as iron, silver, copper, and aluminum, metal plates and plastic films made by vapor deposition of these metals, and alloy plates such as stainless steel and brass. Other examples include substrates such as paper coated with plastic, substrates such as paper with plastic films bonded thereto, and plastic films without an absorption layer (receptive layer). Examples of plastics include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, and polypropylene.

[0140] Furthermore, examples of recording media with low liquid absorbency include recording media having a low absorbency coating layer on the surface. For example, recording media having a paper substrate include printing paper such as art paper, coated paper, and cast paper, and recording media having a plastic film substrate include those having a hydrophilic polymer or the like coated on the surface of polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene, or the like, and those having particles of silica, titanium, or the like coated together with a binder.

[0141] Examples of liquid-absorbent recording media include, but are not limited to, ordinary paper such as electrophotographic paper having high liquid permeability, and inkjet paper (paper exclusively for inkjet printers having an ink-absorbing layer made of silica particles or alumina particles, or an ink-absorbing layer made of hydrophilic polymers such as polyvinyl alcohol (PVA) or polyvinylpyrrolidone (PVP)).Further examples of liquid-absorbent recording media include fabrics and nonwoven fabrics.

[0142] The recording medium may be colorless and transparent, semi-transparent, colored and transparent, chromatic and opaque, achromatic and opaque, etc. Furthermore, the recording medium itself may be colored, semi-transparent, or transparent.

[0143] Among the above-mentioned examples, the recording medium is more preferably a low-absorbency recording medium or a non-absorbency recording medium. Furthermore, the recording surface is made of polyester such as polyethylene terephthalate, and is non-coated without a coating layer. A low-absorbency recording medium or a non-absorbency recording medium whose recording surface is made of polyester and is non-coated has high transparency and is inexpensive, but has a problem of poor adhesion to the ink composition. With such a recording medium, the affinity with the second resin particles made of polyester resin in the inkjet ink composition is increased, so that the effect of the present invention that the image has good adhesion can be more fully enjoyed.

[0144] 2.2. Treatment liquid application process The treatment liquid application step in the recording method according to this embodiment is a step of applying the treatment liquid described above to the recording medium.

[0145] The treatment liquid application step can be carried out simultaneously with the ink application step, or before or after the ink application step.

[0146] Examples of methods for applying the treatment liquid include dip coating, in which the recording medium is immersed in the treatment liquid, roller coating, in which the treatment liquid is applied using a brush, roller, spatula, roll coater, or the like, spray coating, in which the treatment liquid is sprayed using a spray device, and inkjet coating, in which the treatment liquid is applied by an inkjet method, etc. Among these, the inkjet method is preferred.

[0147] In the treatment liquid application step, the amount of treatment liquid applied to the region of the recording medium where the inkjet ink composition and the treatment liquid are applied in an overlapping manner is preferably 5% by mass or more, more preferably 7% by mass or more, and particularly preferably 9% by mass or more, relative to the amount of inkjet ink composition applied in the ink application step. On the other hand, the amount of treatment liquid applied is preferably 25% by mass or less, more preferably 21% by mass or less, even more preferably 17% by mass or less, and particularly preferably 13% by mass or less, relative to the amount of inkjet ink composition applied in the ink application step. When the amount of treatment liquid applied is within the above range, there is a tendency for both image quality and abrasion resistance to be favorably achieved.

[0148] In addition, the amount of treatment liquid applied to the area of ​​the recording medium where the ink-jet ink composition and the treatment liquid are applied in an overlapping manner is 0.1 mg / inch 2 More than 5mg / inch 2 It is also preferable that the amount of treatment liquid applied in the area where the ink and treatment liquid are applied in an overlapping manner on the recording medium is maximum, be within the above range.

[0149] 2.3.Ink application process The ink deposition step in the recording method according to this embodiment is a step of depositing the above-mentioned inkjet ink composition onto a recording medium by an inkjet method.

[0150] In the ink application step, the amount of ink applied per unit area of ​​the recording medium in the region where the ink-jet ink composition is applied is preferably 3 mg / inch 2 More preferably, 5 mg / inch 2 More preferably, it is 10 mg / inch or more. 2 The amount of ink attached per unit area of ​​the recording medium is preferably 20 mg / inch 2 More preferably, 18 mg / inch or less. 2 More preferably, it is 16 mg / inch or less. 2It is also possible and preferable that the amount of ink adhered per unit area of ​​the recording medium in the region where the amount of ink adhered is maximum, that is, the maximum amount of ink adhered, is within the above range.

[0151] 2.4.Recording Device An example of an inkjet recording apparatus that can be suitably used to carry out the recording method according to this embodiment will be described with reference to the drawings.

[0152] <Outline of device configuration> Fig. 1 is a schematic cross-sectional view showing an inkjet recording device. Fig. 2 is a perspective view showing an example of the configuration of the carriage and its surroundings of the inkjet recording device 1 of Fig. 1. As shown in Figs. 1 and 2, the inkjet recording device 1 includes a recording head 2, an IR heater 3, a platen heater 4, a heating heater 5, a cooling fan 6, a pre-heater 7, a ventilation fan 8, a carriage 9, a platen 11, a carriage moving mechanism 13, a transport means 14, and a control unit CONT. In the inkjet recording device 1, the operation of the entire inkjet recording device 1 is controlled by the control unit CONT shown in Fig. 2.

[0153] <Configuration Related to Recording Head> The recording head 2 is configured to perform recording on the recording medium M by ejecting and depositing ink from the nozzles of the recording head 2. The same can be done for the treatment liquid. The recording head 2 shown in Figs. 1 and 2 is a serial type recording head, which scans multiple times in the main scanning direction relative to the recording medium M to deposit ink and treatment liquid onto the recording medium M. The recording head 2 is mounted on a carriage 9 shown in Fig. 2. The recording head 2 is scanned multiple times in the main scanning direction relative to the recording medium M by the operation of a carriage movement mechanism 13 that moves the carriage 9 in the medium width direction of the recording medium M. The medium width direction is the main scanning direction of the recording head 2. Scanning in the main scanning direction is also called main scanning.

[0154] Here, the main scanning direction is the direction in which the carriage 9 carrying the recording head 2 moves. In FIG. 1, it is the direction intersecting the sub-scanning direction, which is the transport direction of the recording medium M, indicated by the arrow SS. In FIG. 2, the width direction of the recording medium M, i.e., the direction indicated by S1-S2, is the main scanning direction MS, and the direction indicated by T1→T2 is the sub-scanning direction SS. Note that scanning is performed in one main scanning direction, i.e., in either the direction indicated by the arrow S1 or the arrow S2, in one scan. Then, recording is performed on the recording medium M by repeating the main scanning of the recording head 2 and the sub-scanning, which is the transport direction of the recording medium M, multiple times.

[0155] The cartridge 12 that supplies ink and treatment liquid to the recording head 2 includes a plurality of independent cartridges. The cartridge 12 is detachably mounted on the carriage 9 on which the recording head 2 is mounted. Each of the plurality of cartridges can be filled with a different type of ink and treatment liquid, and the ink and treatment liquid are supplied from the cartridge 12 to each nozzle. Note that, although an example in which the cartridge 12 is mounted on the carriage 9 is shown in Figs. 1 and 2, the cartridge 12 is not limited to this, and may be provided at a location other than the carriage 9 and supplied to each nozzle by a supply pipe (not shown).

[0156] A conventionally known method can be used for ejecting ink from the recording head 2. In this embodiment, a method for ejecting ink droplets using the vibration of a piezoelectric element, that is, an ejection method for forming ink droplets by mechanical deformation of an electrostrictive element, is used.

[0157] <Primary drying mechanism> The inkjet recording device 1 may include a primary drying mechanism that heats the recording medium M when ink or processing liquid is discharged from the recording head 2 and adhered to the recording medium. The primary drying mechanism may be of a conduction type, an air blowing type, a radiation type, or the like. The conduction type conducts heat to the recording medium from a member that contacts the recording medium. For example, a platen heater or the like may be used. The air blowing type sends normal temperature air or hot air to the recording medium to dry the ink or the like. For example, a fan may be used. The radiation type radiates radiation that generates heat to the recording medium to heat it. For example, IR radiation may be used. Although not shown, a heater similar to the platen heater may be provided immediately downstream of the platen heater 4 in the SS direction. These primary drying mechanisms may be used alone or in combination. For example, an IR heater 3 and a platen heater 4 may be provided as the primary drying mechanism.

[0158] Incidentally, by using the IR heater 3, the recording medium M can be radiatively heated by radiating infrared rays from the recording head 2 side. As a result, the recording head 2 is also likely to be heated at the same time, but compared to heating from the back side of the recording medium M by the platen heater 4 or the like, the temperature can be increased without being affected by the thickness of the recording medium M. Incidentally, various fans (for example, ventilation fan 8) may be provided that blow warm air or air at the same temperature as the environment onto the recording medium M to dry the ink and the like on the recording medium M.

[0159] The platen heater 4 is capable of heating the recording medium M via a platen 11 at a position facing the recording head 2. The platen heater 4 is capable of heating the recording medium M by conduction, and is used as necessary in the inkjet recording method.

[0160] Furthermore, the inkjet recording apparatus 1 may include a preheater 7 that preheats the recording medium M before the ink or treatment liquid is applied to the recording medium M.

[0161] <Post-heating mechanism> A post-heating mechanism may be provided that heats the recording medium after the treatment liquid application step, the first ink application step, and the second ink application step to dry and fix the ink, etc.

[0162] The heater 5 used in the post-heating mechanism dries and solidifies the ink and other materials attached to the recording medium M. When the heater 5 heats the recording medium M on which an image has been recorded, the moisture and other materials contained in the ink and treatment liquid evaporate and dissipate more quickly, and an ink film is formed by the resin contained in the ink. In this way, the ink film is firmly fixed or adhered to the recording medium M, providing excellent film-forming properties, and an excellent, high-quality image can be obtained in a short time.

[0163] <Other configurations> The inkjet recording apparatus 1 may have a cooling fan 6. After the ink recorded on the recording medium M is dried, the ink on the recording medium M is cooled by the cooling fan 6, whereby an ink coating film with good adhesion can be formed on the recording medium M.

[0164] Below the carriage 9, there are provided a platen 11 that supports the recording medium M, a carriage movement mechanism 13 that moves the carriage 9 relatively to the recording medium M, and a transport means 14 that is a roller that transports the recording medium M in the sub-scanning direction. The operations of the carriage movement mechanism 13 and the transport means 14 are controlled by a control unit CONT.

[0165] In the inkjet recording device 1, the recording area on which a plurality of droplets are deposited is gradually transported by repeating main scanning (passes) and sub-scanning (transport operation). Then, the droplets deposited on the recording medium M are dried by a heater 5 to complete the image. Thereafter, the completed recorded matter may be wound into a roll by a winding mechanism, or transported by a flatbed mechanism.

[0166] 2.5.Other processes (1) Primary drying process The recording method according to this embodiment may include a primary drying step of drying the ink and treatment liquid adhered to the recording medium.

[0167] The primary drying process is a process for drying the ink adhered to the recording medium at an early stage. The primary drying process is a process for drying at least a part of the solvent component of the ink adhered to the recording medium to an extent that at least the flow of the ink is reduced. The primary drying process may be performed by blowing air without heating, the ink may be adhered to a heated recording medium, or the ink may be heated early after adhesion.

[0168] The primary drying step may be performed by using an IR heater, microwave radiation, a platen heater, or blowing hot air onto the recording medium using a fan.

[0169] When the primary drying step is performed, the heating temperature, in terms of the surface temperature of the recording surface of the heated recording medium, is preferably 28° C. or higher, more preferably 30° C. or higher, and even more preferably 35° C. or higher. The heating temperature in the primary drying step, in terms of the surface temperature of the recording surface of the heated recording medium, is preferably 50° C. or lower, more preferably 45° C. or lower, and even more preferably 40° C. or lower. This tends to result in excellent clogging recovery properties.

[0170] (2) Post-heating process (secondary drying process) The recording method according to this embodiment may include a post-heating step (secondary drying step) of heating the recording medium after the image is formed.

[0171] The post-heating step is a heating step for heating sufficiently to complete recording and to enable the recorded matter to be used. The post-heating step is a heating step for sufficiently drying the solvent components of the ink and the treatment liquid, and for heating the resin contained in the ink to make the ink coating into a flat film. The post-heating step is preferably started more than 0.5 seconds after an image is formed on the recording medium. For example, it is preferable to start heating a certain recording area of ​​the recording medium more than 0.5 seconds after the attachment of the ink and treatment liquid to the area is completed. In addition, it is preferable that the temperature preferred in the primary heating step is different from the temperature preferred in the post-heating step.

[0172] Heating of the recording medium in the post-heating step can be performed using an appropriate heating means, for example, when an inkjet recording device is used. In addition, the heating means is not limited to the heating means provided in the inkjet recording device, and can be performed by an appropriate heating means. In this case, the surface temperature of the recording medium is preferably 60°C or higher, more preferably 70°C or higher, even more preferably 80°C or higher, and particularly preferably 85°C or higher. In addition, the surface temperature of the recording medium heated in the post-heating step is preferably 120°C or lower, more preferably 110°C or lower, even more preferably 100°C or lower, and particularly preferably 95°C or lower. According to the recording method of this embodiment, even if the surface temperature of the recording medium is within the above range, the ink tends to be sufficiently dried and a recorded matter having excellent abrasion resistance can be obtained.

[0173] 2.6. Effects, etc. According to the recording method of this embodiment, the inkjet ink composition contains first resin particles made of acrylic resin and second resin particles made of polyester resin, the content of the second resin particles being 0.4 times or less the content of the first resin particles, and further contains third resin particles made of polyolefin resin with a predetermined melting point range, thereby obtaining an image with good abrasion resistance. In addition, the inkjet ink composition contains first resin particles and second resin particles with a predetermined glass transition point range, thereby improving the clogging recovery of the inkjet head.

[0174] 3. Examples The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the following, "%" is based on mass unless otherwise specified.

[0175] 3.1. Preparation of treatment liquid and inkjet ink composition The components were mixed to obtain the compositions shown in Tables 1 to 3 to obtain inkjet ink compositions. The components were mixed to obtain the compositions shown in Table 4 to obtain treatment liquids. The compositions in each table are shown in mass %. The coloring material (pigment) and resin particles in the tables each indicate the solid content (active ingredient). Pure water was added so that the total mass of the treatment liquid or ink was 100 mass %.

[0176] In the above tables, "boiling point" refers to the normal boiling point. Also, "glass transition point" and "melting point" were both measured by a standard method using DSC.

[0177] In addition, the characteristics of each substance listed in the table other than the substance name are as follows: ·PG: Propylene glycol 1,2HD: 1,2-Hexanediol BYK-348: Silicone surfactant, manufactured by BYK Japan Co., Ltd. Movinyl 6800: Acrylic resin emulsion, manufactured by Japan Coating Resin Co., Ltd. Joncryl 631: Acrylic resin emulsion, manufactured by BASF Japan Ltd. Elitel KT-8803: Polyester resin emulsion, manufactured by Unitika Ltd. Vylonal MD-2000 polyester resin emulsion, manufactured by Toyobo Co., Ltd. - Hi-Tech E-6314: Polyethylene resin emulsion, manufactured by Toho Chemical Industry Co., Ltd. - Hi-Tech E-6400: Polyethylene resin emulsion, manufactured by Toho Chemical Industry Co., Ltd. Joncryl 1680: Acrylic resin emulsion, manufactured by BASF Japan Ltd. Elitel KT-9204: Polyester resin emulsion, manufactured by Unitika Ltd. HORDAMER PE 03: Polyethylene resin emulsion, manufactured by BYK Japan Co., Ltd. Catiomaster PD-7: Amine-epichlorohydrin copolymer, manufactured by Yokkaichi Chemical Co., Ltd.

[0178] For the cyan pigment, the following pigment dispersion was used. <Black pigment dispersion and yellow pigment dispersion> In a reaction vessel equipped with a reflux tube, a gas inlet, a thermometer and a stirrer, 198.2 parts of diethylene glycol monobutyl ether, 1.0 parts of iodine, 3.7 parts of 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 66.1 parts of tricyclodecyl methacrylate, and 0.17 parts of diphenylmethane as a catalyst were charged. Polymerization was carried out for 5 hours at 45°C while flowing nitrogen, to obtain a solution of A polymer block. Next, the polymerization temperature was lowered to 40°C, and 44.0 parts of tricyclodecyl methacrylate, 17.2 parts of methacrylic acid, and 1.2 parts of 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) were added to the solution of A polymer block obtained above. Then, polymerization was carried out for 4 hours, and then the mixture was heated to 70°C and polymerized for 1 hour to form a B polymer block, to obtain a solution of AB block polymer. After cooling the AB block polymer solution obtained above, 66.1 parts of diethylene glycol monobutyl ether was added, and the mixture was dried at 150°C for 1 hour, resulting in a polymer with a solid content of 33.0%. 341 parts of the polymer, 163.6 parts of butyl carbitol, and 450 parts of CI Pigment Blue 15:3, a cyan pigment, were mixed and stirred with a disperser. The pigment was then thoroughly dispersed with a horizontal media disperser to obtain an oil-based pigment dispersion. Next, while stirring 700 parts of the oil-based pigment dispersion obtained above with a disperser, a mixed liquid consisting of 4.0 parts of potassium hydroxide and 341 parts of water was gradually added to neutralize and cause phase inversion. Next, the pigment was thoroughly dispersed again with a horizontal media disperser to obtain an aqueous pigment dispersion.

[0179] 3.2.Evaluation Methodology 3.2.1. Printing conditions Printing machine: Modified Seiko Epson SC-R5050 Resolution: 1200 x 1200 dpi Print pattern: Solid pattern (cyan) Number of scans: 9 Paper surface temperature: 40℃ Secondary drying temperature: 70℃ Recording media: As follows: M1: SF 100 Ultra Clear, uncoated PET film, manufactured by Avery Dennison Japan Co., Ltd. M2: Orajet 3165G-010, PVC film, manufactured by Orafor Japan Co., Ltd.

[0180] 3.2.2. Measurement of viscosity increase rate The thickening rate was measured as follows. (1) Prepare a 5% by weight aqueous solution of calcium propionate (2) Each resin product was diluted with water to a resin solid content of 5% by mass and measured at a shear rate of 200 s -1 Measure the viscosity of (Viscosity 1) (3) 5 g of resin aqueous medium and 0.5 g of calcium propionate aqueous solution were mixed and stirred 20 times, then the shear rate was 200 s -1 Measure the viscosity of (Viscosity 2) (4) Calculate the viscosity increase rate by dividing viscosity 2 by viscosity 1. The obtained viscosity increase rates are shown in Tables 1 to 3.

[0181] 3.2.3. Evaluation of abrasion resistance Fill the SC-R5050 with ink and print a solid pattern (ink deposition amount 16 mg / inch) on the recording medium. 2 , Processing solution adhesion amount 1.5mg / inch 2 After leaving it at room temperature for 30 minutes, the ink-attached area was cut into a 30 x 150 mm rectangle and rubbed 50 times with a water-dampened plain-woven cloth using a Gakushin-type friction fastness tester (load 500 g). The degree of ink peeling was visually evaluated according to the following criteria, and the results are shown in Table 5. AA: No peeling A: Less than 20% of the evaluation area has peeled off B: Less than 50% of the evaluation area peeled off C: More than 50% of the evaluation area has peeled off.

[0182] 3.2.4. Evaluation of clogging recovery After filling the SC-R5050 with ink, the nozzle surface was struck with a water-moistened Bemcot to intentionally cause nozzles to miss. In this state, the printer was left to run for 2 hours under the paper surface temperature conditions shown in the table. After printing, cleaning was performed three times and the number of unrecovered nozzles was counted. For each cleaning, 1g of ink was discharged from the nozzle group. The nozzle group consisted of 800 nozzles. The treatment liquid was excluded from the evaluation. Evaluation was based on the following criteria, and the results are shown in Table 5. AA: No nozzle non-ejection A: Nozzle non-ejection rate less than 1% B: Nozzle non-ejection rate: 1% to 3% C: Nozzle non-ejection rate 3% or more

[0183] 3.3.Evaluation Results In each example using the ink set, which has an aqueous inkjet ink composition containing a colorant and resin particles, and a treatment liquid containing a flocculant, the resin particles include first resin particles made of an acrylic resin having a glass transition point of 60°C or more and 110°C or less, second resin particles made of a polyester resin having a glass transition point of 60°C or more and 110°C or less, and third resin particles made of a polyolefin resin having a melting point of 110°C or more and 150°C or less, and the content of the second resin particles in the inkjet ink composition is 0.4 times or less the content of the first resin particles, images with excellent abrasion resistance were obtained and recording with good clogging recovery was possible.

[0184] The above-described embodiment and modifications are merely examples, and the present invention is not limited to these. For example, the embodiments and modifications can be appropriately combined.

[0185] The present invention includes configurations that are substantially the same as the configurations described in the embodiments, for example, configurations with the same functions, methods, and results, or configurations with the same purpose and effects. The present invention also includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. The present invention also includes configurations that achieve the same effects as the configurations described in the embodiments, or configurations that can achieve the same purpose. The present invention also includes configurations in which publicly known technology is added to the configurations described in the embodiments.

[0186] The following can be derived from the above-described embodiment and modified examples.

[0187] The ink set is a water-based ink-jet ink composition containing a colorant and resin particles; A treatment liquid containing a flocculant; An ink set having the formula: The resin particles include first resin particles made of an acrylic resin having a glass transition point of 60° C. or more and 110° C. or less, second resin particles made of a polyester resin having a glass transition point of 60° C. or more and 110° C. or less, and third resin particles made of a polyolefin resin having a melting point of 110° C. or more and 150° C. or less, In the inkjet ink composition, the content of the second resin particles is 0.4 times or less the content of the first resin particles.

[0188] According to this ink set, the inkjet ink composition contains first resin particles made of acrylic resin and second resin particles made of polyester resin, the content of the second resin particles being 0.4 times or less the content of the first resin particles, and further contains third resin particles made of polyolefin resin with a predetermined melting point range, thereby obtaining an image with good abrasion resistance. Furthermore, the inkjet ink composition contains first resin particles and second resin particles with a predetermined glass transition point range, thereby enabling the inkjet head to have good recovery from clogging.

[0189] In the above ink set, The glass transition point of the acrylic resin of the first resin particles may be higher than the glass transition point of the polyester resin of the second resin particles.

[0190] This ink set makes it possible to form images with superior abrasion resistance.

[0191] In the above ink set, The content of the second resin particles may be 0.1% by mass or more and 2% by mass or less with respect to the total amount of the inkjet ink composition.

[0192] In the above ink set, The second resin particles may have a higher viscosity increase rate than the first resin particles when a 5% by mass aqueous medium solution of the resin particles is mixed with a 5% by mass aqueous solution of calcium propionate.

[0193] This ink set makes it possible to form images with even better abrasion resistance.

[0194] In the above ink set, The inkjet ink composition contains a water-soluble low molecular weight organic compound, The total content of the water-soluble low-molecular-weight organic compounds may be 10% by mass or more and 30% by mass or less with respect to the total amount of the inkjet ink composition, and the content of water-soluble low-molecular-weight organic compounds having a normal boiling point of 210°C or less may account for 60% by mass or more of the total content of the water-soluble low-molecular-weight organic compounds.

[0195] In the above ink set, A total content of the first resin particles, the second resin particles, and the third resin particles may be 3% by mass or more and 12% by mass or less with respect to the total amount of the inkjet ink composition.

[0196] In the above ink set, The flocculant may be selected from polyvalent metal salts, cationic resins and organic acids.

[0197] This ink set makes it possible to form images with better color development and adhesion.

[0198] In the above ink set, The recording surface of the recording medium is made of polyester and is uncoated, and the recording medium may be a low-absorbency recording medium or a non-absorbency recording medium.

[0199] With this ink set, the effect of good image adhesion can be more significantly achieved.

[0200] The recording method is A recording method using the ink set described above, The method includes a step of ejecting the ink-jet ink composition from an ink-jet head and depositing it onto a recording medium, and a step of depositing the treatment liquid onto the recording medium.

[0201] According to this recording method, the inkjet ink composition contains first resin particles made of acrylic resin and second resin particles made of polyester resin, the content of the second resin particles being 0.4 times or less the content of the first resin particles, and further contains third resin particles made of polyolefin resin with a predetermined melting point range, thereby obtaining an image with good abrasion resistance. Furthermore, the inkjet ink composition contains first resin particles and second resin particles with a predetermined glass transition point range, thereby enabling the inkjet head to have good recovery from clogging. [Explanation of symbols]

[0202] 1... inkjet recording device, 2... recording head, 3... IR heater, 4... platen heater, 5... heater, 6... cooling fan, 7... pre-heater, 8... ventilation fan, 9... carriage, 11... platen, 12... cartridge, 13... carriage moving mechanism, 14... conveying means, CONT... control unit, MS... main scanning direction, SS... sub-scanning direction, M... recording medium

Claims

1. a water-based ink-jet ink composition containing a colorant and resin particles; A treatment liquid containing a flocculant; An ink set having the formula: The resin particles include first resin particles made of an acrylic resin having a glass transition point of 60° C. or more and 110° C. or less, second resin particles made of a polyester resin having a glass transition point of 60° C. or more and 110° C. or less, and third resin particles made of a polyolefin resin having a melting point of 110° C. or more and 150° C. or less, In the inkjet ink composition, the content of the second resin particles is 0.4 times or less the content of the first resin particles.

2. In claim 1, an acrylic resin of the first resin particles having a glass transition point higher than a polyester resin of the second resin particles;

3. In claim 1, the content of the second resin particles is 0.1% by mass or more and 2% by mass or less with respect to the total amount of the inkjet ink composition.

4. In claim 1, An ink set, wherein when a 5% by mass aqueous medium solution of resin particles and a 5% by mass aqueous solution of calcium propionate are mixed, the second resin particles have a higher viscosity increase rate than the first resin particles.

5. In claim 1, The inkjet ink composition contains a water-soluble low molecular weight organic compound, an ink set in which a total content of the water-soluble low molecular weight organic compounds is 10% by mass or more and 30% by mass or less with respect to a total amount of the inkjet ink composition, and a content of water-soluble low molecular weight organic compounds having a normal boiling point of 210° C. or less accounts for 60% by mass or more of the total content of the water-soluble low molecular weight organic compounds.

6. In claim 1, a total content of the first resin particles, the second resin particles, and the third resin particles is 3% by mass or more and 12% by mass or less with respect to a total amount of the inkjet ink composition.

7. In claim 1, The ink set, wherein the coagulant is selected from a polyvalent metal salt, a cationic resin, and an organic acid.

8. In claim 1, An ink set used for recording on a recording medium, which has a non-coated recording surface made of polyester and is a low-absorbency recording medium or a non-absorbency recording medium.

9. A recording method using the ink set according to any one of claims 1 to 8, A recording method comprising: a step of ejecting the inkjet ink composition from an inkjet head and depositing it onto a recording medium; and a step of depositing the treatment liquid onto the recording medium.

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