Solvent-based inkjet ink

Abstract

A rosin resin having an acid value of less than 22 mg KOH / g and a hydroxyl value of 40 mg KOH / g or less, an alcohol, and a Hildebrand solubility parameter of 11 cal 1 / 2 cm -3 / 2 and a co-solvent having a molecular weight of less than 1000 kJ / cm 2 . The inkjet ink is characterized by an extended decap time under a wide range of environmental conditions, and further has excellent continuous printing stability and dry time. Also provided are printed materials comprising the dried form of the inkjet ink, and methods for forming printed images using a thermal inkjet printhead.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority to International Application No. PCT / US2023 / 014036, filed February 28, 2023, the entire contents of which are incorporated herein by reference.

[0002] [Technical field] The present invention relates to solvent-based ink-jet inks, methods for preparing such ink-jet inks, and methods for forming images using such ink-jet inks. [Background technology]

[0003] The "Background" discussion herein is intended to provide an overview of the context relevant to the present disclosure. Work by the inventors named herein that falls within the scope of this Background section, as well as aspects of the disclosure that may not otherwise constitute prior art at the time of filing, are not admitted, expressly or impliedly, to be prior art against the present invention.

[0004] Thermal inkjet (TIJ) printing is a desirable technology for printing, coding, and marking because it offers high print resolution at a lower cost than competing technologies in the field, such as continuous inkjet (CIJ). In the thermal inkjet printing process, ink droplets are produced by thermally evaporating the ink solvent using a series of small chambers arranged in a print cartridge, each equipped with a heater. In the jetting process, a resistor is rapidly heated to create a vapor bubble (hence the term "bubble jet"), which then expels a droplet through an orifice. This process is highly efficient and repeatable, and the latest TIJ printheads for industrial graphic printing applications can produce uniform droplets of less than 4 pL in volume at frequencies of 36 kHz and above.

[0005] However, industrial marking and coding typically requires printing essential information, such as personal information, labels, codes, dates (e.g., expiration dates), and traceability information (e.g., production lot), onto a substrate. Furthermore, such printing occurs under a variety of environmental conditions, such as printing in a cold room for labeling refrigerated foods or in a warm outdoor environment for marking wood products. Thermal inkjet printing can suffer from poor reliability after periods of inactivity. For example, some inkjet inks suffer from short decap times, and solvent loss due to prolonged exposure to air in an uncapped printhead can lead to clogging / blocking of printhead nozzles, resulting in unreliable ink jetting and degradation of image quality over time. This image quality degradation tends to be more severe in low-temperature / low-humidity environments than in higher-temperature / higher-humidity environments. Poor image quality is unacceptable in many applications, but it is especially unacceptable for essential marking and coding information. For this reason, TIJ technology has not seen much acceptance in marking / coding applications, despite its other advantages, and is limited by environmental conditions.

[0006] Solvent-based inkjet inks made with specific combinations of phenolic resins, rosin resin esters, and organic solvents have previously been reported to have acceptable decap times, see U.S. Patent No. 6,273,629, the contents of which are incorporated herein by reference in their entirety. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] US Patent Application Publication No. 2018 / 0072902 Summary of the Invention [Problem to be solved by the invention]

[0008] However, no comparison of such ink systems has been made in a low temperature, dry environment versus a high temperature, high humidity environment.

[0009] [Summary of the Invention] In view of the foregoing, there is a need for inkjet inks that have extended decap times over a wide temperature and humidity range.

[0010] Therefore, one object of the present invention is to provide novel ink-jet inks that meet these criteria.

[0011] Another object of the present disclosure is to provide novel printed articles comprising the inkjet inks in dry form.

[0012] Another object of the present disclosure is to provide a novel method for forming a printed image on a substrate by applying the inkjet ink onto the substrate and drying the ink. [Means for solving the problem]

[0013] These and other objects which will become apparent from the detailed description below are achieved by providing a rosin resin having both an acid number of less than 22 mg KOH / g and a hydroxyl number of 40 mg KOH / g or less, an alcohol, and a Hildebrand solubility parameter of 11 cal. 1 / 2 cm -3 / 2 This was achieved by the inventors' discovery that by combining a co-solvent having a viscosity of less than 1000 psi, an ink-jet ink is provided which is characterized by an extended decap time and good running stability under a wide range of environmental conditions.

[0014] Thus, the present invention provides the following: (1) (A) a rosin resin having an acid value of less than 22 mg KOH / g and a hydroxyl value of 40 mg KOH / g or less; (B1) alcohol, and (B2) Hildebrand solubility parameter is 11 cal 1 / 2 cm-3 / 2 a co-solvent, wherein The weight ratio ((B2):(A)) of the co-solvent (B2) to the rosin resin (A) is 1:1 to 10:1.

[0015] (2) (A) a rosin resin having an acid value of less than 22 mg KOH / g and a hydroxyl value of 40 mg KOH / g or less, and (B) (B1) Alcohol and (B2) Hildebrand solubility parameter is 11 cal 1 / 2 cm -3 / 2 and a co-solvent, wherein the co-solvent is less than The weight ratio ((B2):(A)) of the co-solvent (B2) to the rosin resin (A) is 1:1 to 10:1.

[0016] (3) The ink-jet ink according to (1) or (2), wherein the rosin resin (A) is present in an amount of 0.1 to 10% by weight based on the total weight of the ink-jet ink.

[0017] (4) The ink-jet ink according to any one of (1) to (3), wherein the rosin resin (A) includes a modified rosin resin (A1).

[0018] (5) The ink-jet ink according to any one of (1) to (4), wherein the modified rosin resin (A1) contains a rosin ester.

[0019] (6) The inkjet ink according to (5), wherein the rosin ester comprises at least one selected from the group consisting of glycerol ester of hydrogenated rosin, glycerol-esterified rosin, pentaerythritol ester of hydrogenated rosin, pentaerythritol-esterified rosin, triethylene glycol-esterified rosin, maleic acid-modified rosin ester, and methyl-esterified rosin.

[0020] (7) The ink-jet ink according to any one of (1) to (6), wherein the alcohol (B1) is present in an amount of 75 to 90% by weight based on the total weight of the ink-jet ink.

[0021] (8) The inkjet ink according to any one of (1) to (7), wherein the alcohol (B1) includes at least one selected from the group consisting of methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-pentanol, 3-pentanol, and t-amyl alcohol.

[0022] (9) The ink-jet ink according to any one of (1) to (8), wherein the alcohol (B1) includes ethanol.

[0023] (10) The ink-jet ink according to any one of (1) to (9), wherein the co-solvent (B2) is present in an amount of 1 to 20% by weight based on the total weight of the ink-jet ink.

[0024] (11) The ink-jet ink according to any one of (1) to (10), wherein the co-solvent (B2) is at least one selected from the group consisting of ethylene glycol monobutyl ether acetate, propylene glycol methyl ether acetate, acetone, and cyclohexanone.

[0025] (12) The ink-jet ink according to any one of (1) to (11), further comprising a colorant (C).

[0026] (13) The ink-jet ink according to (12), wherein the colorant (C) is present in an amount of 0.1 to 15% by weight based on the total weight of the ink-jet ink.

[0027] (14) The ink-jet ink according to any one of (1) to (13), further comprising (D) silicone.

[0028] (15) The ink-jet ink according to (14), wherein the silicone (D) is present in an amount of 0.001 to 4% by weight based on the total weight of the ink-jet ink.

[0029] (16) The ink-jet ink according to any one of (1) to (15), further comprising (E) a pH adjuster in an amount of 0.1 to 5 wt % based on the total weight of the ink-jet ink.

[0030] (17) The ink-jet ink according to (16), wherein the pH adjuster (E) contains an amine.

[0031] (18) The ink-jet ink according to (17), wherein the amine comprises an alkanolamine.

[0032] (19) A printed matter comprising a substrate and the inkjet ink according to any one of (1) to (18) in a dried form disposed on the substrate.

[0033] (20) A method for forming a printed image on a substrate, comprising: applying the inkjet ink according to any one of (1) to (18) onto the substrate using a thermal inkjet printhead; and drying the ink-jet ink. [Brief explanation of the drawings]

[0034] The preceding paragraphs have been provided as a general introduction and are not intended to limit the scope of the claims that follow. The described embodiments and further attendant advantages will be best understood by referring to the following detailed description taken in conjunction with the accompanying drawings, in which:

[0035] [Figure 1A] FIG. 1A shows the decap time rating corresponding to a "good" rating, where the image size is 2.7 inches by 0.5 inches (6.9 cm by 1.8 cm). [Figure 1B]FIG. 1B shows the decap time rating corresponding to an "acceptable" rating, where the image size is 2.7 inches by 0.5 inches (6.9 cm by 1.8 cm). [Figure 1C] FIG. 1C shows the decap time rating corresponding to a "poor" rating, where the image size is 2.7 inches by 0.5 inches (6.9 cm by 1.8 cm). DETAILED DESCRIPTION OF THE INVENTION

[0036] In the following description, it is understood that other embodiments may be utilized and structural and operational changes may be made without departing from the scope of the present embodiments disclosed herein.

[0037] The present disclosure will be better understood with reference to the following definitions. As used herein, words such as "a" and "an" mean "one or more" and "at least one." When numerical limits or ranges are specified in the description of this disclosure, the endpoints are included unless otherwise stated. Furthermore, the terms "comprises" and / or "comprising," when used herein, specify the presence of stated features, integers, steps, operations, components, and / or ingredients, but do not exclude the presence or addition of one or more other features, integers, steps, operations, components, ingredients, and / or groups thereof.

[0038] The present disclosure also contemplates other embodiments that "comprising," "consisting of," and "consisting essentially of" the embodiments or elements set forth herein, whether explicitly stated or not. Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. All patents and other publications mentioned herein are hereby incorporated by reference in their entirety and as if fully set forth.

[0039] As used herein, the terms "about," "approximately," or "substantially similar" may be used when describing a size and / or location to indicate that the stated value and / or location is within a reasonably expected range of values ​​and / or locations. For example, a numerical value may be + / - 0.1% of the stated value (or range of values), + / - 1% of the stated value (or range of values), + / - 2% of the stated value (or range of values), + / - 5% of the stated value (or range of values), + / - 10% of the stated value (or range of values), + / - 15% of the stated value (or range of values), or + / - 20% of the stated value (or range of values). When numerical limits or ranges are specified in the description of this disclosure, the endpoints are included unless otherwise stated. Also, all values ​​and subranges within the numerical limits or ranges are specifically included as if explicitly stated.

[0040] Unless otherwise specified, the phrase "substantially free" indicates that the amount of a particular component in the inkjet ink is less than 1 wt %, preferably less than 0.5 wt %, more preferably less than 0.1 wt %, even more preferably less than 0.05 wt %, and even more preferably 0 wt %, based on the total weight of the inkjet ink.

[0041] As used herein, the terms "optional" or "optionally" mean that the event described after the term may or may not occur, or that the ingredient described after the term may or may not be present (e.g., it may be 0% by weight).

[0042] As used herein, "compound" refers to a chemical entity whether solid, liquid, or gas, and whether present in a crude mixture or isolated and purified.

[0043] The term "alkyl," as used herein, unless otherwise specified, refers to a straight-chain, branched, or cyclic aliphatic fragment having at least 1, preferably at least 2, preferably at least 3, preferably at least 4, and up to 22, preferably up to 20, preferably up to 18, preferably up to 12, preferably up to 8 carbon atoms. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, isopentyl, neopentyl, hexyl, isohexyl, 3-methylpentyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, lauryl, myristyl, cetyl, stearyl, and the like, including, but not limited to, Guerbet-type alkyl groups (e.g., 2-methylpentyl, 2-ethylhexyl, 2-propylheptyl, 2-butyloctyl, 2-pentylnonyl, 2-hexyldecyl, 2-heptylundecyl, 2-octyldodecyl, 2-nonyltridecyl, 2-decyltetradecyl, and 2-undecylpentadecyl). Cycloalkyl is a type of cyclized alkyl group. Representative cycloalkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, norbornyl, and adamantyl.

[0044] As used herein, the term "fatty" refers to compounds that have a long-chain (straight-chain) hydrophobic moiety composed of hydrogen and any number of carbon atoms from 8 to 22, and the hydrophobic moiety may be fully saturated or partially unsaturated.

[0045] The term "aryl" as used herein refers to aromatic groups containing only carbon in the aromatic ring(s), including phenyl, biphenyl, naphthyl, anthracenyl, and the like.

[0046] The term "arylalkyl," as used herein, refers to a straight-chain, branched, or cyclic alkyl moiety (as defined above) substituted with an aryl group (as defined above), which may itself be optionally substituted with an alkyl group, examples of which include, but are not limited to, benzyl, phenethyl, 3-phenylpropyl, 2-phenylpropyl, 1-phenylpropyl, 4-phenylbutyl, 3-phenylbutyl, 2-phenylbutyl, 2-methylbenzyl, 3-methylbenzyl, 4-methylbenzyl, 2,4-dimethylbenzyl, 2-(4-ethylphenyl)ethyl, 3-(3-propylphenyl)propyl, and the like.

[0047] The term "(meth)acrylate" is used herein to refer to both acrylate and methacrylate groups. In other words, the term should be interpreted such that the "meth" portion is optional. Furthermore, the term "(meth)acrylate" is generally used to refer to both acrylic acid-based compounds and acrylic ester-based compounds.

[0048] Throughout the specification, the term "boiling point" (bp) refers to the boiling point of a liquid measured at interfacial pressure (i.e., 760 mmHg or 1 atmosphere), also known as the normal boiling point, unless otherwise stated.

[0049] As used herein, the term "decap behavior" refers to the ability of an inkjet ink to be easily ejected from a printhead when exposed to air for an extended period of time. The "decap time" of an inkjet ink is measured as the amount of time an inkjet printhead can be left uncapped before the nozzles no longer eject ink properly when printing resumes, possibly due to clogging or blockage. Generally, nozzles can become clogged (i.e., flow is impeded or slowed) or blocked (i.e., blocked or substantially or completely closed) due to the formation of a viscous plug within the nozzle as a result of solvent loss, ink crusting, and / or kogation of various ink components within and / or around any nozzle. When a nozzle is clogged, ink droplets ejected through the nozzle opening can be misdirected, adversely affecting print quality. When an opening is blocked, the opening is substantially or completely blocked. A blocked nozzle can result in ink droplets being unable to pass through the nozzle in question. Thus, the criterion for measuring nozzle ejection failure is that the ink passing through the nozzle opening is more or less misdirected or completely blocked, which can be measured by visually inspecting the printed image.

[0050] (inkjet ink) The present disclosure relates to inkjet inks that have suitable physical and chemical stability at both ambient and printhead operating temperatures, jet reliably, dry quickly after application to a substrate, have extended decap times under a wide range of environmental conditions, and have good continuous print stability.

[0051] The inkjet inks of the present disclosure generally include the following components: (A) a rosin resin having an acid value of less than 22 mg KOH / g and a hydroxyl value of 40 mg KOH / g or less, (B1) an alcohol, and (B2) a Hildebrand solubility parameter of 11 cal 1 / 2 cm-3 / 2 Co-solvents that are less than

[0052] The inkjet ink of the present disclosure may optionally further comprise one or more of (A1) a modified rosin resin, (C) a colorant, (D) a silicone, (E) a pH adjuster, and (F) an additive.

[0053] (A) Rosin resin The inkjet ink of the present disclosure is prepared by incorporating a rosin resin (A). Typically, the rosin resin (A) is used in an amount of at least 0.1 wt %, at least 0.2 wt %, at least 0.4 wt %, at least 0.6 wt %, at least 0.8 wt %, at least 1.0 wt %, at least 1.1 wt %, at least 1.2 wt %, at least 1.4 wt %, at least 1.6 wt %, at least 1.8 wt %, at least 2 wt %, at least 2.2 wt %, at least 2.4 wt %, at least 2.5 wt %, and / or at most 10 wt %, at most 9 wt %, at most 8 wt %, at most 7 wt %, at most 6 wt %, at most 5.5 wt %, or at most 5 wt %, based on the total weight of the inkjet ink. In one embodiment, the rosin resin (A) is present in an amount of 0.1 to 10% by weight, more preferably 0.5 to 8% by weight, even more preferably 1.0 to 7% by weight, even more preferably 1.5 to 6% by weight, or even more preferably 2.5 to 5% by weight, based on the total weight of the inkjet ink.

[0054] The rosin resin (A) may be derived from gum rosin; wood rosin of grades B, C, D, E, F, FF, G, H, I, J, K, L, M, N, WG, and WW (as defined in ASTM 0509); virgin rosin; hard rosin; yellow dip rosin; NF wood rosin; tall oil rosin; or colophony or colophonium, as well as any of the single components derived from various types of natural rosins, such as abietic acid, abietic acid, sylvic acid, dihydroabietic acid, tetrahydroabietic acid, dehydroabietic acid, neoabietic acid, pimaric acid, levopimaric acid, isopimaric acid, sandaracopimaric acid, palustric acid, dextropimaric acid, isodextropimaric acid, and dextropimarinal. , isodextropimarinal, xanthoperol, tatarol, podocarpic acid, phyllocladene, sugiol, ferruginol, himokiol, manool, manoyl oxide, ketomanoyl oxide, cativinic acid, eperuanic acid, and any other rosin component based on the diterpene skeleton of abietic acid; and mixtures thereof having at least one carboxylic, sulfonic, or phosphoric acid (optionally introduced by oxidation) available for silylation. The term "rosin" can refer to any mixture of the above-listed species, as well as to the species themselves.

[0055] The rosin resin (A) preferably comprises a modified rosin resin (A1). Such modified rosin resins may be formed by esterification, hydrogenation (including partial hydrogenation), dimerization, and / or other modification / functionalization (e.g., by Diels-Alder reaction with an unsaturated dibasic acid such as maleic or fumaric acid / anhydride, reduction of a carboxylic acid to the corresponding aldehyde / alcohol, double bond isomerization, dehydrogenation, oxidation, disproportionation, etc.) of the rosin resin.

[0056] In a preferred embodiment, the modified rosin resin (A1) comprises a rosin ester. In one embodiment, rosin esters include rosin resins, hydrogenated rosin resins, and other modified rosin resins esterified with glycerol, pentaerythritol, triethylene glycol, ethylene glycol, diethylene glycol, methanol, and / or maleic acid.

[0057] Representative rosin esters include HARIESTER products available from Harima Chemicals, Inc.; glycerol esters of hydrogenated rosin, such as STAYBELITE ESTER 10-E, and pentaerythritol esters of gum rosin, such as PERMALYN 6110, both available from Eastman; highly stabilized rosin esters, such as SUPER ESTER A-125 and SUPER ESTER A-75, polymerized rosin esters, such as PENSEL D-125; hydrogenated rosin esters, such as PINECRYSTAL KE-100, glycerol esters of hydrogenated rosin, such as PINECRYSTAL KE-311, and pentaerythritol esters of hydrogenated rosin, such as PINECRYSTAL KE-359, all available from Arakawa Chemical Industries, Ltd.; stabilized pentaerythritol esters of rosin, such as PINEREZ 2308A and PINECLEAR 4306A, and FILTREZ Maleic acid-modified rosin esters, such as 3305, all available from Lawter; glycerol esters of hydrogenated wood rosin, such as FORAL 85, pentaerythritol esters of hydrogenated rosin, such as FORAL 105, and methyl esters of hydrogenated rosin, such as HERCOLYN D, all available from DRT; glycerol esters of partially dimerized rosin, such as PEXALYN ESTER 10, glycerol esters of rosin, such as PEXALYN 9085, pentaerythritol esters of stabilized rosin, such as PEXALYN 9100, and pentaerythritol esters of hydrogenated stabilized wood rosin, such as PENTALYN H, all available from Pinova, Inc.; and functionalized rosin resins, such as esters (glycerol esters) of rosin modified with maleic anhydride or rosin subjected to carboxylic acid reducing conditions, including, but not limited to, LEWISOL 28-M, available from Synthomer.

[0058] Other representative modified rosin resins (A1) besides the above rosin esters include, but are not limited to, hydrogenated acidic rosins such as FORAL AX and FORAL DX, both available from Pinova; partially hydrogenated acidic rosins such as STAYBELITE RESIN-E, available from Pinova, and STAYBELITE and STAYBELITE A, both available from Synthomer; dimerized rosins such as POLY-PALE, available from Synthomer; and ABITOL E hydroabietyl alcohol, available from Synthomer.

[0059] In one embodiment, the modified rosin resin (A1) preferably contains at least one selected from the group consisting of a glycerol ester of hydrogenated rosin, a glycerol-esterified rosin, a pentaerythritol ester of hydrogenated rosin, a pentaerythritol-esterified rosin, a triethylene glycol-esterified rosin, a maleic acid-modified rosin ester, and a methyl-esterified rosin. In a preferred embodiment, the modified rosin resin (A1) contains a glycerol ester of hydrogenated rosin.

[0060] In one embodiment, the rosin resin (A) comprises both a modified rosin resin (A1) and an unmodified rosin resin. For example, the rosin resin (A) preferably comprises at least 40% by weight, more preferably at least 60% by weight, even more preferably at least 70% by weight, even more preferably at least 80% by weight, even more preferably at least 90% by weight, even more preferably at least 95% by weight, and even more preferably at least 99% by weight of the modified rosin resin (A1), based on the total weight of the modified rosin resin (A1) and the unmodified rosin resin.

[0061] In one embodiment, the hydroxyl value (OHV) of the rosin resin (A) is 40 mgKOH / g or less, preferably 38 mgKOH / g or less, more preferably 35 mgKOH / g or less, even more preferably 30 mgKOH / g or less, even more preferably 25 mgKOH / g or less, even more preferably 20 mgKOH / g or less, even more preferably 15 mgKOH / g or less, even more preferably 10 mgKOH / g or less, and / or preferably greater than 1 mgKOH / g, more preferably greater than 5 mgKOH / g, even more preferably greater than 8 mgKOH / g. The hydroxyl value (OHV) is defined as the amount of potassium hydroxide in milligrams required to neutralize the acetic acid absorbed when acetylating 1 gram of a chemical substance having a free hydroxyl group. The hydroxyl value can be determined in accordance with Japanese Industrial Standard JIS K0070:1992, "Test Methods for Acid Value, Saponification Value, Ester Value, Iodine Value, Hydroxyl Value, and Unsaponifiable Matter of Chemical Products."

[0062] In one embodiment, the acid number (AV) of the rosin resin (A) is less than 22 mgKOH / g, preferably less than 20 mgKOH / g, more preferably less than 18 mgKOH / g, even more preferably less than 16 mgKOH / g, even more preferably less than 14 mgKOH / g, even more preferably less than 12 mgKOH / g, even more preferably less than 10 mgKOH / g, even more preferably less than 8 mgKOH / g, even more preferably less than 7 mgKOH / g, and / or preferably greater than 1 mgKOH / g, more preferably greater than 2 mgKOH / g, even more preferably greater than 3 mgKOH / g, even more preferably greater than 4 mgKOH / g, even more preferably greater than 5 mgKOH / g, or even more preferably greater than 6 mgKOH / g. In one embodiment, the acid value of the rosin resin (A) is preferably in the range of 1 to 22 mgKOH / g, more preferably in the range of 2 to 20 mgKOH / g, even more preferably in the range of 3 to 18 mgKOH / g, even more preferably in the range of 4 to 16 mgKOH / g, even more preferably in the range of 5 to 14 mgKOH / g, or even more preferably in the range of 6 to 12 mgKOH / g. The acid value represents the amount (mg) of potassium hydroxide required to completely neutralize 1 g of resin. The acid value can also be measured according to the aforementioned Japanese Industrial Standard JIS K 0070:1992. Representative embodiments of the rosin resin (A) having an acid value of less than 22 mg KOH / g include, but are not limited to, PINECRYSTAL KE-311 (AV=6 mg KOH / g, OHV=9 mg KOH / g), a glycerol ester of hydrogenated rosin manufactured by Arakawa Chemical Industries, Ltd., and PINECLEAR 4306A (AV=18 mg KOH / g, OHV=25 mg KOH / g), a rosin ester manufactured by Lawter.

[0063] The modified rosin resin (A1) having an acid value of less than 22 mg KOH / g and a hydroxyl value of 40 mg KOH / g or less has a Hildebrand solubility parameter of 11 cal 1 / 2 cm -3 / 2It has been observed that when used in combination with a co-solvent (B2) and alcohol (B1) having a viscosity of less than 100 psi, the modified rosin resin (A1) exhibits excellent decap times while maintaining good dry times. Without being bound by theory, it is believed that the modified rosin resin (A1) improves the decap behavior of inkjet inks by forming a thin "skin" or film that coats the inside of the printhead nozzles, thereby creating a temporary seal that prevents or reduces solvent loss during periods of inactivity, but that the "skin" can easily be broken once printing operations resume.

[0064] (B) Solvent-based For many printing processes utilizing solvent-based inks, particularly thermal inkjet printing, the selection of an appropriate solvent system can affect the reliability of the printing process, the properties / appearance of the ink print, and the overall efficiency of the printing process. For example, in thermal inkjet printing, the selection of a solvent system can: 1) aid in bubble formation during the jetting process, resulting in reliable ink jetting; 2) affect the stability / volatility of the inkjet ink by changing the interaction kinetics between the solvent and various inkjet ink components, which in turn can affect decap behavior, kogation, and / or droplet trajectory; 3) affect the adhesion, rub and scratch resistance, and optical density properties of the printed image due to the interaction forces between the solvent system and other inkjet ink components, even when the solvent is no longer present or has reduced amounts after drying; 4) affect the drying time after application or the equipment required to dry the applied ink; and / or 5) affect droplet dynamics.

[0065] Based on the above, the Hildebrand solubility parameter of alcohol (B1) is 11 cal 1 / 2 cm -3 / 2 Particularly preferred is an inkjet ink comprising a solvent system (B) comprising a co-solvent (B2) in which

[0066] The alcohol (B1) of the present disclosure means a compound in which one hydrogen atom of an alkyl group is substituted with one hydroxyl group, that is, a compound having an alkyl group and a hydroxyl group.

[0067] The amount of alcohol (B1) present in the inkjet ink may be at least 75% by weight, at least 76% by weight, and / or up to 92% by weight, up to 91% by weight, up to 90% by weight, up to 89% by weight, up to 88% by weight, up to 87% by weight, up to 86% by weight, up to 85% by weight, up to 84% by weight, up to 83% by weight, up to 82% by weight, up to 81% by weight, up to 80% by weight, based on the total weight of the inkjet ink. In one embodiment, alcohol (B1) is preferably present in an amount of 75 to 92% by weight, more preferably 76 to 88% by weight, and even more preferably 76 to 80% by weight, based on the total weight of the inkjet ink.

[0068] In one embodiment, the alcohol (B1) contains at least 1, preferably at least 2, and may contain up to 8, preferably up to 6, more preferably up to 5, even more preferably up to 4, and even more preferably up to 3 carbon atoms. Preferred alcohols (B1) are those having a boiling point below 120°C, preferably below 110°C, more preferably below 100°C, even more preferably below 90°C, and even more preferably below 85°C.

[0069] In one embodiment, the alcohol (B1) comprises at least one selected from the group consisting of methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-pentanol, 3-pentanol, and t-amyl alcohol. Preferably, the alcohol (B1) comprises at least one selected from the group consisting of methanol, ethanol, 1-propanol, and 2-propanol. In a preferred embodiment, the alcohol (B1) comprises ethanol.

[0070] The inclusion of co-solvent (B2) can promote solvation of the inkjet ink components, provide polarity compatibility with the rosin resin (A) for desirable decap behavior, and provide the inkjet ink with acceptable volatility in terms of drying time. The preferred amount of co-solvent (B2) present in the inkjet ink is at least 1 wt %, more preferably at least 1.5 wt %, even more preferably at least 2 wt %, even more preferably at least 2.5 wt %, and / or up to 20 wt %, more preferably up to 15 wt %, even more preferably up to 12 wt %, and even more preferably up to 10 wt %, based on the total weight of the inkjet ink. In one embodiment, co-solvent (B2) is preferably present in an amount of 1 to 20 wt %, more preferably 2 to 15 wt %, and even more preferably 2.5 to 10 wt %, based on the total weight of the inkjet ink.

[0071] The Hildebrand solubility parameter of the cosolvent (B2) is 11 cal 1 / 2 cm -3 / 2 Less than 10.5 cal, preferably 1 / 2 cm -3 / 2 Less than and / or preferably 7.5 cal 1 / 2 cm -3 / 2 More than 8 cal 1 / 2 cm -3 / 2 More than 8.5 cal, preferably 1 / 2 cm -3 / 2 In one embodiment, the co-solvent (B2) preferably has a Hildebrand solubility parameter of 7.5 to 11 cal 1 / 2 cm -3 / 2 Within the range of 8 to 10.5 cal 1 / 2 cm -3 / 2 Within the range of 8.5 to 10.5 cal 1 / 2 cm -3 / 2 is within the range.

[0072] The Hildebrand solubility parameter (δ) is a tabulated value for many different polymers and solvents, allowing for an estimation of compatibility. In this application, the Hildebrand solubility parameter (δ) is referred to as "cal1 / 2 cm -3 / 2 It is expressed in units of δ. The Hildebrand solubility parameter numerically estimates the degree of interaction between materials and can be an excellent indicator of solubility, especially for materials such as polymers. Materials with similar δ values ​​are considered to be easily miscible with each other. The Hildebrand solubility parameter is the square root of the cohesive energy density and can be calculated using the following formula:

[0073]

number

[0074] where ΔHυ is the enthalpy of vaporization of the solvent in question, R is the gas constant, T is the temperature, and V m is the molar volume of the solvent in question. If the Hildebrand solubility parameter δ at room temperature is 11 cal 1 / 2 cm -3 / 2 As a solvent with a viscosity of less than 1000 ppm, ethylene glycol monobutyl ether acetate (δ = 8.90 cal 1 / 2 cm -3 / 2 ), propylene glycol methyl ether acetate (8.90 cal 1 / 2 cm -3 / 2 ), acetone (9.77 cal 1 / 2 cm -3 / 2 ), cyclohexanone (10.40 cal 1 / 2 cm -3 / 2 ), n-pentane (7.0 cal 1 / 2 cm -3 / 2 ), n-hexane (7.24 cal 1 / 2 cm -3 / 2 ), diethyl ether (7.62 cal 1 / 2 cm -3 / 2 ), ethyl acetate (9.1 cal 1 / 2 cm -3 / 2 ), chloroform (9.21 cal 1 / 2 cm -3 / 2 ), dichloromethane (9.93 cal 1 / 2 cm -3 / 2 ), methyl ethyl ketone (9.0 cal 1 / 2 cm -3 / 2 ), and 1,3-dioxolane (8.6 cal 1 / 2 cm-3 / 2 ), but are not limited to these.

[0075] In one embodiment, the co-solvent (B2) is at least one selected from the group consisting of ethylene glycol monobutyl ether acetate (EB acetate), propylene glycol methyl ether acetate (PM acetate), acetone, and cyclohexanone. In a preferred embodiment, the co-solvent (B2) comprises ethylene glycol monobutyl ether acetate.

[0076] In one embodiment, the weight ratio of the cosolvent (B2) to the rosin resin (A) ((B2):(A)) is preferably 1:1 to 10:1, or more preferably 1.5:1 to 8:1, or even more preferably 2:1 to 6:1, or even more preferably 2:1 to 5:1.

[0077] In some embodiments, the inkjet ink is preferably substantially free of solvents having a boiling point greater than 255°C, more preferably greater than 250°C, even more preferably greater than 245°C, even more preferably greater than 240°C, even more preferably greater than 235°C, even more preferably greater than 230°C, even more preferably greater than 220°C, even more preferably greater than 210°C, even more preferably greater than 200°C, or even more preferably greater than 195°C.

[0078] In some embodiments, the inkjet inks of the present disclosure are preferably substantially non-aqueous, meaning that no water is added to the inkjet ink, except for what may be incidental moisture from ambient conditions. For example, the inkjet ink may have a water content of less than 1 wt %, less than 0.5 wt %, less than 0.1 wt %, less than 0.05 wt %, less than 0.01 wt %, or even 0 wt %, based on the total weight of the inkjet ink.

[0079] (C) Colorant The inkjet ink of the present disclosure preferably contains a colorant (C) to provide a colored ink that can be used in a variety of printing applications, but the inkjet ink is not limited to a specific color. In addition to imparting color to the inkjet ink, the colorant (C) may also be capable of improving the lightfastness, weather resistance, etc. of the printed image. Any colorant (C), including dyes, pigments, mixtures thereof, etc., may be used to impart a desired color to the inkjet ink, provided that the colorant (C) is soluble or dispersible in the inkjet ink. Suitable colors include, for example, cyan, magenta, yellow, and key (black) (“CMYK”), white, orange, green, light cyan, light magenta, violet, etc. (including both spot colors and process colors). Inkjet inks can be prepared by blending various dyes, with metal complex dyes being particularly preferred.

[0080] In one embodiment, the metal complex dyes used as colorant (C) further include metal complex azo dyes, which are compounds formed with a metal center and a ligand containing an azo functionality (also known as a diazenyl functionality). Typically, the ligand containing an azo functionality is a molecule that can itself be considered an azo dye.

[0081] The ligand containing the azo functionality is coordinated to a metal center, typically a transition metal or main group metal or metalloid, but not an alkali metal or alkaline earth metal. Examples of suitable metals that can form the metal center include, but are not limited to, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, zirconium, niobium, molybdenum, ruthenium, rhodium, cadmium, aluminum, indium, tin, bismuth, and mixtures thereof. Such coordination can be via any suitable functional group present on the ligand.

[0082] In preferred embodiments, the metal center is a chromium ion. In some embodiments, the chromium ion is in the +3 oxidation state. In such embodiments, the metal complex may have a positive charge, a negative charge, or no charge. In embodiments in which the metal complex has a positive charge, the metal complex azo dye may further contain any suitable anion for charge balance. Examples of such suitable anions include, but are not limited to, carboxylate, halide, sulfate, phosphate, hydrogen phosphate, dihydrogen phosphate, nitrate, and mixtures thereof. In embodiments in which the metal complex has a negative charge, the metal complex azo dye may further contain any suitable cation for charge balance. Examples of such suitable cations include, but are not limited to, alkali metals, alkaline earth metals, ammonium compounds, and mixtures thereof.

[0083] Examples of suitable metal complex azo dyes include, but are not limited to, Solvent Black 27, Solvent Black 28, Solvent Black 29, Solvent Black 34, Solvent Blue 137, Solvent Brown 37, Solvent Brown 42, Solvent Brown 43, Solvent Brown 52, Solvent Orange 54, Solvent Red 8, Solvent Red 109, Solvent Red 119, Solvent Red 122, Solvent Yellow 19, Solvent Yellow 21, Solvent Yellow 25, Solvent Yellow 79, Solvent Yellow 82, Solvent Yellow 88, Solvent Yellow 146, Solvent Violet 58, Solvent Violet 61, and Solvent Yellow 79.

[0084] Among these, more preferred examples include Solvent Black 27, Solvent Black 29, Solvent Yellow 79, and onium salts of Basic Red 1 and Acid Yellow 23. Commercially available Solvent Black 27 products include VALIFAST Black 3820, VALIFAST Black 3830, and VALIFAST Black 3840, while commercially available Solvent Black 29 products include VALIFAST Black 3808 and VALIFAST Black 3870. Commercially available onium salts of Basic Red 1 and Acid Yellow 23 include VALIFAST Red 1355, and commercially available Solvent Yellow 79 products include VALIFAST YELLOW 3150 (all of which are available from Orient Chemical Industry Co., Ltd.). Of these, Solvent Black 27 is more preferred.

[0085] In some embodiments, the inkjet ink comprises colorant (C) in a concentration of preferably at least 0.1 wt.-%, more preferably at least 0.5 wt.-%, even more preferably at least 1 wt.-%, even more preferably at least 1.5 wt.-%, even more preferably at least 2 wt.-%, even more preferably at least 2.5 wt.-%, even more preferably at least 3 wt.-%, even more preferably at least 3.5 wt.-%, even more preferably at least 4 wt.-%, even more preferably at least 4.5 wt.-%, even more preferably at least 5 wt.-%, even more preferably at least 5.5 wt.-%, even more preferably at least 6 wt.-%, even more preferably at least 6.5 wt.-%, even more preferably at least 7 wt.-%, and / or preferably at most 15 wt.-%, more preferably at most 14.5 wt.-%, even more preferably at most 14 wt.-%, even more preferably at most 13.5 wt.-%, even more preferably at most 13 wt.-%, even more preferably at most 12.5 wt.-%, even more preferably at most 12 wt.-%, even more preferably at most 11.5 wt.-%, even more preferably at most 11 wt.-%, even more preferably at most 10.5 wt.-%, even more preferably at most 10 wt.-%, based on the total weight of the inkjet ink. In one embodiment, the colorant (C) is present in an amount of preferably 0.1 to 15 wt %, more preferably 2 to 14 wt %, even more preferably 4 to 12 wt %, even more preferably 5 to 10 wt %, or even more preferably 6 to 8 wt %, based on the total weight of the inkjet ink.

[0086] (D) Silicone In some embodiments, the inkjet ink preferably further comprises a silicone (D). The silicone (D) controls the wetting properties of the ink, contributing to improved image quality. The silicone (D) can act as a surfactant, imparting, among other benefits, anti-blocking, ink receptivity, leveling, anti-cratering, improved surface slip, and / or substrate wetting, without impairing the decap performance of the inkjet ink.

[0087] As the silicone (D), from the viewpoint of improving wettability, amine-modified silicones, polyether-modified silicones, carboxy-modified silicones, alkyl-modified silicones, and aralkyl-modified silicones are preferred, and from the viewpoint of improving adhesion to substrates, amine-modified silicones are preferred.

[0088] In one embodiment, the silicone (D) is an amine-modified silicone. The amine-modified silicone may be a block copolymer having a pendant graft structure, comprising or consisting of (i) a silicone backbone (main chain), (ii) one or more organic amine side chains attached to the silicone backbone, and optionally (iii) one or more aliphatic alkyl side chains attached to the silicone backbone. Therefore, as long as at least one organic amine side chain is attached to the silicone backbone, the material satisfies the definition of "amine-modified silicone," regardless of whether other types of side chains (e.g., aliphatic alkyl side chains) are also attached to the silicone backbone. In the amine-modified silicone, it is preferred that no other side chains are present except for the organic amine side chains and any optional aliphatic alkyl side chains.

[0089] The "side chains" referred to herein are not extensions of the silicone backbone, as in, for example, linear block copolymers of ABA structure, but are attached to the silicone backbone (main chain) as pendant grafts, thereby forming branch points on the silicone backbone, with the side chains extending from the silicone backbone via covalent bonds. Preferred organoamine-modified silicones are non-hydrolyzable, i.e., the side chains are attached to the silicone backbone via Si-C bonds.

[0090] <(i) Silicone backbone> The silicone backbone may be based on any organosilicon polymer or oligomer (polyorganosiloxane) of various molecular weights with a linear or branched structure; such polymers or oligomers may be formed by polymerization and / or polycondensation of appropriately functionalized silanes and have a polysiloxane backbone structure (silicon atoms linked via oxygen atoms, -Si-O-Si-) with alkyl, aryl, and / or arylalkyl groups bonded directly to the (tetravalent) silicon atoms. For example, the polyorganosiloxane backbone may be a linear structure, including, but not limited to, a polydimethylsiloxane (dimethicone) backbone (in which each silicon atom is directly bonded to two methyl groups), a poly(dimethylsiloxane-co-methylphenylsiloxane) backbone, a poly(dimethylsiloxane-co-diphenylsiloxane) backbone, and a poly(dimethylsiloxane-co-methylalkylsiloxane) backbone, or a branched structure, specifically including polydimethylsiloxyethyl dimethicone.

[0091] <(ii) Organic amine side chain> The amine-modified silicone comprises at least one organic amine side chain based on an organic amine or an amine-containing polymer (e.g., formed by ring-opening polymerization of one or more alkyleneimines), such as polyaziridine, with ethyleneimine (aziridine) and propyleneimine being most preferred, including copolymers thereof, such as block copolymers. The organic amine side chain is preferably an alkylamine, arylamine, arylalkylamine, aliphatic amine, or polyaziridine, extending from the silicone backbone.

[0092] The organic amine side chain may include a primary amine, a secondary amine, a tertiary amine, or a combination thereof. Such amines may be present in any suitable number, for example, from 1 to 1,000. In some embodiments, preferred organic amine side chains are selected from the group consisting of monoamines containing a primary amine and diamines containing a primary amine and a secondary amine. Such monoamines may be alkylamines, arylamines, arylalkylamines, or aliphatic amines. Such diamines may be alkylamines, arylamines, arylalkylamines, or aliphatic amines.

[0093] <(iii) Aliphatic Alkyl Side Chain> The amine-modified silicone may optionally be further modified with one or more fatty alkyl side chains, including those containing at least 8, preferably at least 10, more preferably at least 12, and up to 22, preferably up to 20, more preferably up to 18, even more preferably up to 16, and even more preferably up to 14 carbon atoms. Representative fatty alkyl side chain groups include, but are not limited to, capryl, nonyl, decyl, undecyl, lauryl, tridecyl, myristyl, pentadecyl, cetyl, palmitoleic, heptadecyl, stearyl, oleyl, arachidyl, and behenyl, especially lauryl, myristyl, cetyl, and stearyl, with lauryl being preferred.

[0094] <(iv) Polyether Side Chain> The amine-modified silicone may optionally be further modified with one or more polyether side chains. The polyether side chains may be based, for example, on polyalkylene glycol oligomers or polyalkylene glycol polymers formed from the ring-opening polymerization of one or more alkylene oxides, with ethylene oxide (EO), propylene oxide (PO), and / or butylene oxide (BO) being most preferred, including copolymers thereof such as block copolymers. Preferably, the polyether side chains are polyethylene glycol or polyethylene glycol-polypropylene glycol copolymers extending from the silicone backbone, and more preferably, the polyether side chains are polyethylene glycol side chains formed exclusively with ethylene oxide, i.e., EO.

[0095] Polyether side chains of various lengths may be utilized, typically the number of moles of alkylene oxide units per side chain is at least 2 mol, preferably at least 3 mol, more preferably at least 4 mol, even more preferably at least 5 mol, even more preferably at least 6 mol, and in the range of up to 50 mol, preferably up to 40 mol, preferably up to 30 mol, preferably up to 20 mol, preferably up to 15 mol, more preferably up to 12 mol, even more preferably up to 10 mol, even more preferably up to 9 mol, with 3 to 10 mol, preferably 4 to 9 mol, of ethylene oxide (EO) units per side chain being particularly preferred.

[0096] Additionally, any polyether side chains present may be uncapped (whereby the end of the polyether side chain opposite the silicone backbone terminates with -H, forming a terminal hydroxyl functionality) or may be capped with alkyl groups having 1, 2, 3, or 4 carbon atoms (forming a terminal alkyl ether group), such alkyl groups including methyl, ethyl, propyl, and butyl, among others.

[0097] In some embodiments, the amine-modified silicone is a block copolymer having pendant graft structures, for example, as represented by formula (IA):

[0098] [ka]

[0099] During the ceremony, o is 0 or a positive integer, for example an integer of at least 1, preferably at least 2, more preferably at least 3, even more preferably at least 4, even more preferably at least 5, and up to 500, preferably up to 400, preferably up to 300, more preferably up to 200, even more preferably up to 100, even more preferably up to 50; p represents the number of constitutional units containing an organic amine side chain and is a positive integer, for example, at least 1, preferably at least 2, more preferably at least 3, even more preferably at least 4, even more preferably at least 5, and is an integer up to 100, preferably up to 80, preferably up to 60, more preferably up to 40, even more preferably up to 20, even more preferably up to 10; and A is an amine-containing group (organoamine) as described above.

[0100] In some embodiments, a preferred amine-modified silicone is a block copolymer having a pendant graft structure and a diamine structure containing a primary amine and a secondary amine, for example, as represented by formula (IB).

[0101] [ka]

[0102] Preferred amine-modified silicones having the above structure are KF-859, KF-393, KF-860, KF-880, KF-8004, KF-8002, KF-8005, KF-867, KF-8021, KF-869, and KF-861, all available from Shin-Etsu Chemical Co.

[0103] Amine-modified silicones with pendant graft structures are formed from a linear polydimethylsiloxane backbone containing one or more organic amine side chains.

[0104] In some embodiments, the amine-modified silicone is a block copolymer having a pendant graft structure and, optionally, one or more aliphatic alkyl or polyether side chains as described above. In some embodiments, the amine-modified silicone is a block copolymer having a pendant graft structure, the pendant graft structure having a branched polydimethylsiloxane backbone containing one or more organic amine side chains and, optionally, one or more aliphatic alkyl or polyether side chains as described above.

[0105] In some embodiments, the inkjet ink is substantially free of non-amine-functionalized silicones. Examples of such silicones include unmodified silicones (e.g., those without side chains containing non-siloxane functional groups) and modified silicones having only functional groups other than amine functional groups, such as polyether-modified silicones (e.g., those with only polyether side chains), mercapto-modified silicones, vinyl-modified silicones, silanol-modified silicones, hydride-modified silicones, epoxy-modified silicones, (meth)acrylate-modified silicones, carboxylate-modified silicones, and haloalkyl-modified silicones. In some embodiments, the inkjet ink is devoid of non-amine-functionalized silicones. That is, the inkjet ink is free of non-amine-functionalized silicones. In such embodiments, the amine-modified silicone is the only silicone present in the inkjet ink. In some embodiments in which the inkjet ink is devoid of non-amine-functionalized silicones, the amine-modified silicone may contain or include other functional groups, such as those listed above. In some embodiments in which the inkjet ink is devoid of non-amine-functionalized silicones, the amine-modified silicone does not contain or include other functional groups. That is, the inkjet ink is devoid of silicones without amine functionalization, and any amine-modified silicones present are devoid of non-amine functional groups.

[0106] In some embodiments, the silicone (D) has a viscosity of at least 25 mm when measured at 25° C. 2 / s, preferably at least 30 mm 2 / s, preferably at least 35 mm 2 / s, preferably at least 40 mm 2 / s, preferably at least 45 mm 2 / s, preferably at least 50 mm 2 / s, preferably at least 55 mm 2 / s, preferably at least 60 mm 2 / s and 250 mm2 / s, preferably 240 mm 2 / s, preferably 230 mm 2 / s, preferably 220 mm 2 / s, preferably up to 210 mm 2 / s, preferably up to 200 mm 2 / s, preferably 190 mm 2 / s, preferably 180 mm 2 / s, preferably 170 mm 2 / s, preferably 160 mm 2 / s, preferably 150 mm 2 / s, preferably 140 mm 2 / s, preferably 130 mm 2 / s, preferably 120 mm 2 / s, preferably 110 mm 2 / s.

[0107] In some embodiments, the silicone (D) has an amine functional group equivalent weight (FGEW) of 350 to 11,000 g / mol, preferably 1,000 to 9,000 g / mol, preferably 1,500 to 8,800 g / mol, preferably 1,700 to 7,600 g / mol, preferably 2,000 to 7,000 g / mol, preferably 3,000 to 6,500 g / mol, preferably 5,000 to 6,000 g / mol. The functional group equivalent weight refers to the weight of the amine-modified silicone containing one mole of amine functional groups based on the molecular formula.

[0108] Suitable examples of amine-modified silicones used in the disclosed inkjet inks include KF-865 (monoamino, viscosity 110 mm at 25° C.), both available from Shin-Etsu Chemical Co. 2 / s, functional group equivalent weight (FGEW) = 5,000), KF-868 (monoamino, viscosity 90 mm at 25 °C) 2 / s, FGEW=8,800), KF-864 (monoamino, viscosity at 25°C 1,700mm 2 / s, FGEW=3,800), KF-859 (diamino, viscosity 60mm at 25°C) 2 / s, FGEW=6,000), KF-393 (diamino, viscosity 70mm at 25°C) 2 / s, FGEW=350), KF-860 (diamino, viscosity 250mm at 25°C) 2 / s, FGEW=7,600), KF-880 (diamino, viscosity 650mm at 25°C) 2 / s, FGEW=1,800), KF-8004 (diamino, viscosity 800mm at 25°C) 2 / s, FGEW=1,500), KF-8002 (diamino, viscosity 1,100 mm at 25°C) 2 / s, FGEW=1,700), KF-8005 (diamino, viscosity 1,200mm at 25°C) 2 / s, FGEW=11,000), KF-867 (diamino, viscosity 1300mm at 25°C) 2 / s, FGEW=1,700), KF-8021 (diamino, viscosity 15,000mm at 25°C) 2 / s, FGEW=55,000), KF-869 (diamino, viscosity 1,500mm at 25°C) 2 / s, FGEW=3,800), and KF-861 (diamino, viscosity 3,500 mm at 25°C) 2 / s, FGEW=2,000). In a preferred embodiment, the amine-modified silicone is KF-859.

[0109] The silicone (D) may be present in the inkjet ink in an amount of preferably at least 0.001 wt%, more preferably at least 0.01 wt%, even more preferably at least 0.05 wt%, even more preferably at least 0.1 wt%, at least 0.2 wt%, at least 0.5 wt%, and / or preferably at most 4 wt%, preferably at most 3.5 wt%, even more preferably at most 3 wt%, even more preferably at most 2.5 wt%, even more preferably at most 2 wt%, even more preferably at most 1.5 wt%, even more preferably at most 1 wt%, based on the total weight of the inkjet ink. In one embodiment, the silicone (D) may be present in an amount of preferably 0.001 wt% to 4 wt%, more preferably 0.05 to 3 wt%, even more preferably 0.1 to 2.5 wt%, even more preferably 0.2 to 2 wt%, or even more preferably 0.5 to 1.5 wt%, even more preferably 0.5 to 1 wt%, based on the total weight of the inkjet ink.

[0110] (E) pH adjuster In some embodiments, the inkjet ink further comprises a pH adjuster (E), which improves the solubility of the dye, thereby increasing the stability of the ink and improving the print finish (enhancing the quality of color formation).

[0111] In a preferred embodiment, the pH adjuster (E) contains an amine. The amine is preferably an alkylamine, an alkoxyalkylamine, a diamine, a polyamine, or an alkanolamine. Among these, alkanolamine is more preferred from the viewpoint of improving the alcohol solubility of the dye.

[0112] Alkanolamines are alkane-based compounds containing both a hydroxyl (—OH) group and an amine (primary, secondary, or tertiary) group. In some embodiments, the alkanolamine has a total of at least 2, at least 3, at least 4, and / or up to 8, 7, 6, or 5 carbon atoms. In a preferred embodiment, the alkanolamine has 3 carbon atoms.

[0113] In a preferred embodiment, the alkanolamine used in the inkjet inks described herein has the general formula II:

[0114] [ka]

[0115] wherein X, Y, and Z are each independently selected from the group consisting of hydrogen; a C1-C5 alkyl group, preferably a C2-C3 alkyl group; and an alkanol group, preferably a C2-C5 alkanol group, more preferably a C3-C4 alkanol group, and at least one of X, Y, and Z is an alkanol group (an alkyl substituent having at least one hydroxyl group).

[0116] In some embodiments, one of X, Y, and Z is an alkanol group. In some embodiments, two of X, Y, and Z are alkanol groups. In some embodiments, X, Y, and Z are all alkanol groups. With respect to the one or more alkanol groups, the alkyl chain may contain branching. Alternatively, the alkyl chain of the alkanol group may be linear (without alkyl branching). In a preferred embodiment, the alkanol group is based on a linear alkyl chain. The carbon bearing the hydroxyl group in the alkanol group may be a primary, secondary, or tertiary carbon, preferably a primary or secondary carbon.

[0117] Alkanolamines may contain primary amine groups (i.e., two of X, Y, and Z are hydrogen), secondary amine groups (i.e., one of X, Y, and Z is hydrogen), or tertiary amine groups (i.e., X, Y, and Z are all non-hydrogen). When using alkanolamines containing secondary amine groups, the two non-hydrogen substituents may be the same or different alkanol groups, preferably the same alkanol group, as in, for example, diethanolamine. When using alkanolamines containing tertiary amine groups, the three non-hydrogen substituents may be the same or different alkanol groups, preferably the same alkanol group, as in, for example, triethanolamine.

[0118] Examples of suitable alkanolamines include, but are not limited to, isopropanolamine, ethanolamine, N-methylethanolamine, N,N-dimethylethanolamine, N-ethylethanolamine, N-propylethanolamine, N-isopropylethanolamine, N,N-diisopropylethanolamine, N-butylethanolamine, diethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, triethanolamine, propanolamine (3-amino-1-propanol), N-methylpropanolamine, N,N-dimethylpropanolamine, dipropanolamine, tripropanolamine, N,N-dimethylisopropanolamine, diisopropanolamine, triisopropanolamine, 2-amino-2-methyl-1-propanol, 2-amino-2-ethyl-1,3-propanediol, 4-amino-1-butanol, 2-amino-1-butanol, sec-butanolamine, and di-sec-butanolamine, as well as various stereoisomers thereof, as well as mixtures thereof. In a preferred embodiment, the alkanolamine comprises at least one selected from the group consisting of isopropanolamine, ethanolamine, propanolamine (3-amino-1-propanol), diethanolamine, and triethanolamine. In a preferred embodiment, the alkanolamine comprises isopropanolamine (1-amino-2-propanol).

[0119] In some embodiments, the pH adjuster (E) is present in the inkjet ink in an amount of preferably at least 0.1 wt%, more preferably at least 0.2 wt%, even more preferably at least 0.4 wt%, even more preferably at least 0.5 wt%, even more preferably at least 0.6 wt%, even more preferably at least 0.7 wt%, even more preferably at least 0.8 wt%, and / or preferably at most 5 wt%, more preferably at most 4.5 wt%, even more preferably at most 4 wt%, even more preferably at most 3.5 wt%, even more preferably at most 3 wt%, even more preferably at most 2.5 wt%, even more preferably at most 2 wt%, even more preferably at most 1.5 wt%, based on the total weight of the inkjet ink. In one embodiment, the amount of pH adjuster (E) present in the inkjet ink is preferably in the range of 0.1 to 5 wt%, more preferably in the range of 0.2 to 4 wt%, even more preferably in the range of 0.5 to 2 wt%, even more preferably in the range of 0.8 to 1.5 wt%, based on the total weight of the inkjet ink. In some embodiments, the weight ratio of the rosin resin (A) to the pH adjuster (E) ((A):(E)) is preferably within the range of 1:1 to 10:1, more preferably within the range of 1.2:1 to 6:1, even more preferably within the range of 2:1 to 5:1, or even more preferably within the range of 2.2:1 to 5:1, and even more preferably within the range of 2.5:1 to 5:1.

[0120] (F) Additives In some embodiments, the inkjet ink may include one or more additional components or additives, such as additional resins, binders, tackifiers, or adhesives, including, but not limited to:

[0121] Terpene resins, for example, resins based on monoterpene monomer units, where the monoterpene may be, for example, a linear monoterpene (e.g., myrcene, ocimene, etc.), a monocyclic monoterpene (e.g., limonene, γ-terpinene, α-phellandrene, β-phellandrene, terpinolene, etc.), or a bicyclic monoterpene (e.g., 3-carene, α-pinene, β-pinene, α-fenchene, camphene, etc.), including various stereoisomers thereof and mixtures thereof. Examples of terpene resins include, but are not limited to, PICCOLYTE A115, PICCOLYTE A125, PICCOLYTE A135, PICCOLYTE A135 PLUS, PICCOLYTE AO PLUS, PICCOLYTE A25, and PINOVA RESIN 2495, which are manufactured using high-purity α-pinene as a raw material, and PICCOLYTE S25 (manufactured using high-purity β-pinene as a raw material), all of which are available from Pinova.

[0122] Terpene phenolic resins are resins containing terpene and phenol structural units. Terpene phenolic resins are copolymerization products produced by alkylating one or more phenolic compounds with one or more terpenes. Examples of terpene phenolic resins include, but are not limited to, YS POLYSTER products such as YS POLYSTER U130, YS POLYSTER U115, YS POLYSTER T160, and YS POLYSTER T145 available from Yasuhara Chemical Co. Ltd., and DERTOPHENE products such as DERTOPHENE T, DERTOPHENE T105, DERTOPHENE T115, and DERTOPHENE T160 available from DRT.

[0123] Other phenolic resins (i.e., copolymers of phenolic compounds and formaldehyde), such as novolac resins such as PHENOLITE TD-2131 and PHENOLITE TD-2090 available from DIC Corp. Polyamide resins, such as VERSAMID 725, VERSAMID 744, VERSAMID 756, and VERSAMID 759 available from BASF Japan Ltd., TOHMIDE 90, TOHMIDE 92, and TOHMIDE 394-N available from Sanho Chemical Co. Ltd., and SUNMIDE 550, SUNMIDE 554, SUNMIDE 615A, SUNMIDE 638, and SUNMIDE 640 available from Evonik.

[0124] Epoxy resins, including sulfonamide-modified epoxy resins, such as AD-PRO MTS available from Rit-Chem.

[0125] (Meth)acrylate resins and styrene / (meth)acrylate resins, such as JONCRYL 63, JONCRYL 67, JONCRYL 586, JONCRYL 611, JONCRYL 680, JONCRYL 682, and JONCRYL 693 available from BASF, PARALOID DM-55 and PARALOID B-66 available from Palmer Holland, PARALOID B-72 available from Dow Chemical, USA, and ELVACITE 2013 available from Lucite Inc.

[0126] Polyurethane resins, including those formed by the reaction between (i) and (ii): (i) polyols, including, but not limited to, ethylene glycol, propylene glycol, propanediol, butanediol, polyethylene glycol, polypropylene glycol, polytetrahydrofuran diol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, polyester polyols (such as polyethylene glycol adipate diol, polyethylene glycol succinate diol, poly(3-methyl-1,5-pentanediol adipate) glycol, poly(3-methyl-1,5-pentanediol terephthalate) glycol), and carbonate polyols, and (ii) diisocyanates, including, but not limited to, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4-diphenylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate. For example, PERMAX 200, PERMAX 202, and SANCURE 20025F available from Lubrizol.

[0127] Polyvinyl butyral resins, such as PIOLOFORM BN16 and MOWITAL B20H available from Kuraray America, Inc.

[0128] -Polyhydroxystyrene resin, such as DuPont poly(p-hydroxystyrene).

[0129] Vinyl resins, such as UCAR VYHH, VMCH, VMCA, and VAGF available from Dow Chemical Company, and VINNOL E15 / 45, H14 / 36, E15 / 45M, and E16 / 40A available from Wacker Chemie AG, Germany.

[0130] Formaldehyde resins, including sulfonamide-modified formaldehyde resins such as p-toluenesulfonamide formaldehyde resin, melamine formaldehyde resin, and sulfonamide-modified melamine formaldehyde resin.

[0131] Cellulose ester resins, such as cellulose acetate butyrate (CAB-551-0.01) available from Eastman.

[0132] opacifying agents, including, but not limited to, titanium dioxide, zirconium silicate, zirconium oxide, tin oxide, cerium oxide, zinc oxide, aluminum oxide, silica, kaolin, calcium carbonate, magnesium carbonate, calcium magnesium carbonate, barium carbonate, sodium feldspar, potassium feldspar, nepheline, calcium silicate, mullite, wollastonite, and talc;

[0133] Ketone solvents, including but not limited to acetone, methyl ethyl ketone (MEK), 3-pentanone, methyl n-propyl ketone, methyl isopropyl ketone, ethyl isopropyl ketone, and methyl isobutyl ketone.

[0134] glycol ethers, such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-t-butyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-n-propyl ether, propylene glycol monoisopropyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol monomethyl ether, ethylene glycol mono-n-butyl ether acetate, propylene glycol methyl ether acetate, diethylene glycol mono-n-butyl ether acetate, diethylene glycol monoethyl ether acetate, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol mono-n-propyl ether, and mixtures thereof;

[0135] -Polyesters, sulfonated polyesters, gums, cellulose ethers, cellulose nitrate resins, polymaleic anhydrides, acetal polymers, styrene / butadiene copolymers, ketone aldehyde resins, and polyketone resins.

[0136] - Anti-kogation agents, stabilizers, wetting agents, security taggants, other resins, binders, tackifiers, adhesives, rust inhibitors, or other inkjet ink additives known to those skilled in the art.

[0137] -Similar substances, including mixtures of these.

[0138] In one embodiment, the additive (F) may include a surfactant in addition to or instead of the amine-modified silicone (D). Examples of the surfactant include, but are not limited to, the following:

[0139] Polysiloxanes, including organically modified silicones (e.g., alkyl-modified silicones, aryl-modified silicones, and / or arylalkyl-modified silicones) other than the amine-modified silicone (D), such as SILTECH C-32 available from Siltech Corporation, COATOSIL 1211C and COATOSIL 3573, both available from Momentive, KF-410 (arylalkyl-modified polydimethylsiloxane) available from Shin-Etsu Chemical Co., and BYK-322 and BYK-323 (arylalkyl-modified poly(dimethylsiloxane-co-methylalkylsiloxane)), both available from BYKA additives & instruments.

[0140] Silicone acrylate copolymers, such as KP-541, KP-543, KP-545, KP-550, and KP-575 (acrylic polymers with polydimethylsiloxane side chains grafted thereto, available from Shin-Etsu Chemical Co., Ltd.) and BYK-3550 (available from BYK Japan KK).

[0141] Polyether-modified silicones, including block copolymers with pendant graft structures formed from a linear or branched polydimethylsiloxane backbone containing one or more polyether side chains and, optionally, one or more aliphatic alkyl side chains. Examples of polyether-modified silicones include, but are not limited to, KF-6013 (PEG-9 dimethicone, unmodified, HLB=10.0), KF-6015 (PEG-3 dimethicone, unmodified, HLB=4.5), KF-6017 (PEG-10 dimethicone, unmodified, HLB=4.5), and KF-6038 (lauryl PEG-9 polydimethylsiloxyethyl dimethicone, unmodified, HLB=3.0), all available from Shin-Etsu Chemical Co., and BYK-307 (polyether-modified polydimethylsiloxane) available from BYK Additives & Instruments.

[0142] Fluoropolymers, such as FC-4430 and FC-4432 available from 3M Corporation.

[0143] Photocrosslinkable silicone acrylates or silicone polyether acrylates, such as TEGO RAD 2100, TEGO RAD 2200, TEGO RAD 2250, TEGO RAD 2300 (silicone polyether acrylates), all available from Evonik Industries, and BYK-UV 3500 and BYK-UV 3530, available from BYK.

[0144] Polyacrylates, including polyacrylate copolymers and crosspolymers, such as BYK-381 and BYK-361N (polyacrylate copolymers), both available from BYK, and PEMULEN EZ-4U (acrylates / C10-C30 alkyl acrylate crosspolymer) and PEMULEN TR-2 (acrylic acid / C10-C30 alkyl acrylate crosspolymer), both available from Lubrizol.

[0145] -Acetylenic diol and acetylene glycol based zwitterionic surfactants, such as SURFYNOL SEF and DYNOL surfactants available from Evonik Industries.

[0146] Polysiloxane-based zwitterionic surfactants, such as TEGO TWIN 4100 available from Evonik Industries.

[0147] - Non-ionic polyethers as substrate wetting surfactants, such as TEGO WET 510 (hydrophilic polyether substrate wetting surfactant) available from Evonik Industries.

[0148] - Amides or monoalkanolamides of fatty acids, including alkoxylated monoalkanolamides of fatty acids, such as coconut fatty acid monoethanolamide and coconut fatty acid monoethanolamide, reacted with 2 to 20 moles of ethylene oxide.

[0149] ethers, including alkoxylated C1-C, including alkoxylated fatty alcohols such as BIO-SOFT N-600 (C12-C13 alcohol ethoxylate), MAKON DA-4 (ethoxylated isodecyl alcohol), MERPOL SE (alcohol ethoxylate), and POLYSTEP TD-6 (ethoxylated tridecyl alcohol), all available from Stepan; 22 Alcohols; ethylene oxide / propylene oxide copolymers; alkoxylated alkylphenols; and alkyl polyglycosides (APGs) such as those produced by the reaction of fatty alcohols with glucose.

[0150] - fatty esters, such as ethoxylated and / or propoxylated fatty acids (e.g., castor oil containing 2 to 40 moles of ethylene oxide); alkoxylated glycerides (e.g., PEG-24 glyceryl monostearate); glycol esters and derivatives; monoglycerides; polyglyceryl esters; esters of polyalcohols; sorbitan / sorbitol esters such as sorbitan monolaurate (e.g., EMASOL L-10V available from Kao); and polysorbates, such as mono-, di-, or tri-esterified polysorbates of fatty acids, such as TOXIMUL SEE-340 (sorbitan trioleate ethoxylate (20)) available from Stepan.

[0151] Fatty alcohol glycosides, such as PLANTASENS NATURAL EMULSIFIER HE20 (cetearyl glucoside, sorbitan olivate) available from Clariant.

[0152] Any of the additives listed above, including surfactants, may be present in any of the inkjet inks of the present disclosure at a concentration of at least 0.0001 wt.%, at least 0.0005 wt.%, at least 0.001 wt.%, at least 0.005 wt.%, at least 0.01 wt.%, at least 0.05 wt.%, at least 0.1 wt.%, at least 0.2 wt.%, at least 0.4 wt.%, at least 0.5 wt.%, at least 0.7 wt.%, at least 1 wt.%, at least 1.2 wt.%, at least 1.5 wt.%, at least 1.7 wt.%, at least 2 wt.%, and / or up to 10 wt.%, up to 9 wt.%, up to 8 wt.%, up to 7 wt.%, up to 6 wt.%, up to 5 wt.%, up to 4.5 wt.%, up to 4 wt.%, up to 3.5 wt.%, up to 3 wt.%, based on the total weight of the inkjet ink.

[0153] Alternatively, the inkjet ink may be free or substantially free of any of the additives or compounds listed above, including surfactants, meaning that the concentration of such additives or compounds in the inkjet ink is less than 1 wt%, less than 0.5 wt%, less than 0.1 wt%, less than 0.05 wt%, less than 0.001 wt%, less than 0.0001 wt%, less than 0.00001 wt%, or 0 wt%.

[0154] In some embodiments, the inkjet ink is preferably substantially free of terpene resin. In some embodiments, the inkjet ink is preferably substantially free of phenolic resin. In some embodiments, the inkjet ink is preferably substantially free of terpene phenolic resin. In alternative embodiments, the inkjet ink is substantially free of colorant (C), amine-modified silicone (D), surfactant, and / or pH adjuster (E). In one embodiment, the inkjet ink has a Hildebrand solubility parameter of 11 cal. 1 / 2 cm -3 / 2 In one embodiment, the inkjet ink is substantially free of rosin resins and modified rosin resins having an acid number of 22 mg KOH / g or more and / or a hydroxyl number of more than 40 mg KOH / g.

[0155] Manufacturing method Inkjet inks of embodiments described herein may be prepared by any suitable technique known to those skilled in the art, such as by combining the rosin resin (A) or modified rosin resin (A1) and any desired optional ingredients (e.g., colorant (C), amine-modified silicone (D), pH adjuster (E), and / or additive (F)) in any order with a suitable solvent system (B) comprising alcohol (B1) and co-solvent (B2), followed by stirring, agitation, and / or homogenization at a temperature of 20° C. to 100° C. for a suitable period of time to form a uniform solution.

[0156] For example, an inkjet ink may be prepared by first combining rosin resin (A) with alcohol (B1) and co-solvent (B2), and optional resins, solvents, surfactants, or other additives in a container, followed by stirring for at least 10 minutes. The final component, colorant (C), may then be added while continuing to mix, and the solution may then be mixed for at least 10 minutes to obtain the inkjet ink. The resulting inkjet ink may then be placed in a print cartridge, such as a Hewlett-Packard HP45Si printer cartridge, a Funai TIJ cartridge, or other printhead suitable for solvent-based inks.

[0157] characteristics The inkjet inks disclosed herein have extended decap times over a wide range of temperatures and humidity, as measured, for example, by printing, exposing the inkjet ink to air (decapping the ink cartridge) for a specified period of time (e.g., 1 minute, 10 minutes, 30 minutes, 60 minutes, etc.), reprinting the same image, and then comparing the decapped reprinted image with the original image to determine whether loss of lines / line clarity has occurred in the fine line image. If no loss of lines / line clarity has occurred during the tested time interval, the inkjet ink is assigned a decap rating of "good" for that time interval. If 1 to 10 lines have been lost or clarity has decreased during the tested time interval, but the loss does not significantly affect the clarity or readability of the image, the inkjet ink is assigned an "acceptable" decap rating for that time interval. If more than 10 missing lines occur or there is a substantial decrease in clarity and / or readability during the tested time interval, the inkjet ink is classified as "poor" for that time interval. Suitable inkjet inks are those that have an "acceptable" or "good" decap classification when decapped (i.e., exposed to air) for 30 seconds or more, preferably 1 minute or more, more preferably 10 minutes or more, even more preferably 30 minutes or more, and even more preferably 60 minutes or more. Inkjet inks that have an "acceptable" or "good" decap classification for longer periods are considered to have good "intermittent printability."

[0158] The inkjet inks disclosed herein may also be characterized by their long-term continuous print stability (also known as ink life or print life). Continuous print stability of an inkjet ink may be tested by printing a fine-line image (e.g., a barcode) (1 mm x 1 cm, fine lines, monochrome bitmap) over multiple pages without interruption (e.g., 3,000 pages printed in a continuous print run), and visually inspecting specific pages (e.g., pages 1,000, 2,000, and 3,000) for missing nozzles to assess print quality throughout the print run. If the inspected page shows no missing / blurred lines, the inkjet ink is assigned a continuous print stability rating of "G" (good) for that page. If the inspected page shows one or two missing / blurred lines, but not enough to significantly affect the clarity or readability of the fine-line image, the inkjet ink is assigned a continuous print stability rating of "A" (acceptable) for that page. If the inspected page has more than two missing / obscured lines, the inkjet ink is given a continuous print stability rating of "NG" (poor) for that print. An inkjet ink that maintains a rating of "G" or "A", preferably a rating of "G", when printed for at least 100 pages, preferably at least 500 pages, preferably at least 1,000 pages, preferably at least 1,500 pages, preferably at least 2,000 pages, preferably at least 2,500 pages, preferably at least 3,000 pages, preferably at least 3,500 pages, preferably at least 4,000 pages, preferably at least 4,500 pages, preferably at least 5,000 pages is considered to have desirable continuous print stability (ability to remain dispersed / suspended without settling / settling or improper jetting).

[0159] (Printed material) The printed article of the present invention comprises a substrate and the ink-jet ink of the present invention in dry form disposed on the substrate.

[0160] Inkjet inks can be printed on a variety of substrates, including three-dimensional parts and flat sheets or webs supplied in roll form, for the production of a wide variety of printed products. While flat substrates are suitable for forming printed products, a particular advantage of the present disclosure is that the disclosed inkjet inks (with long throw distance capabilities) enable the formation of printed images on complex three-dimensional substrates, such as those with radiused, curved, sawtooth, wavy, grooved, edged, and / or structured surfaces (e.g., grained surfaces). All of these substrates are notoriously difficult to print on due to the long distances the ink must travel to reach all parts of the complex surface. The printed material may be suitable for use in the graphic arts, textile, packaging (e.g., food packaging, pharmaceutical packaging, etc.), lotteries, direct mail, business forms, and publishing industries, including, for example, tags or labels, lottery tickets, publications, packaging (e.g., food packaging, pharmaceutical packaging, blister packs, various flexible packaging, etc.), folding cartons, rigid containers (e.g., plastic cups or tubs, glass containers, metal cans, bottles such as PET bottles, jars, and tubes), envelopes, corrugated cardboard, promotional displays, etc. Particularly preferred printed materials are those in which the inkjet ink in dry form is disposed on complex three-dimensional features of the printed material, for example, a printed image disposed on a grooved or wavy portion of a plastic container or the concave domed bottom of a metal can.

[0161] Inkjet inks may be printed onto porous (i.e., permeable) substrates, examples of which include, but are not limited to, uncoated paper, wood, film, corrugated board (corrugated paper / corrugated fiberboard), and fabrics (e.g., woven fabrics, nonwoven fabrics, and foil-laminated fabrics).

[0162] Inkjet inks can also be printed on non-porous (i.e., non-porous) substrates, such as various plastics, glass, metals (e.g., steel, aluminum, etc.), and / or non-porous papers (e.g., coated papers such as varnish-coated papers), including, but not limited to, molded plastic or metal parts and flat sheets or rolls of plastic or metal films. Examples of such substrates include polyesters such as polyethylene terephthalate (PET); biaxially oriented polystyrene (OPS); polyolefins such as polyethylene (PE), polypropylene (PP), oriented polypropylene (OPP), and biaxially oriented polypropylene (BOPP); polylactic acid (PLA); nylon and oriented nylon; polyvinyl chloride (PVC); cellulose triacetate (TAC); polycarbonate; acrylonitrile butadiene styrene (ABS); polyacetal; polyvinyl alcohol (PVA); coated papers such as varnish-coated papers; and metals such as steel and aluminum.

[0163] (Method for forming a printed image) The present invention method for forming a printed image on a substrate comprises applying the present invention ink-jet ink onto the substrate using a thermal ink-jet printhead and allowing the ink-jet ink to dry.

[0164] In inkjet printing, a desired printed image is created when a precise pattern of dots is ejected onto a print medium from a droplet-generating device known as a printhead. The printhead has an array of precisely formed nozzles located on a nozzle plate and attached to an inkjet printhead substrate. The inkjet printhead substrate incorporates an array of firing chambers that receive inkjet ink through fluid communication with one or more ink reservoirs. Each firing chamber contains a resistive element, known as a firing resistor, located opposite the nozzle so that inkjet ink collects between the firing resistor and the nozzle. Each resistor element is typically a pad of resistive material, measuring, for example, approximately 35 μm by 35 μm. The printhead is held and protected by a housing known as a print cartridge or inkjet pen. When a particular resistor element is energized, a droplet of inkjet ink is expelled through the nozzle toward the print medium. Ink droplet ejection is typically under the control of a microprocessor, whose signals are transmitted to the resistor elements by electrical traces to form alphanumeric and other image patterns on the print medium. Because nozzles are small, typically 10 μm to 40 μm in diameter, inks that minimize clogging are desirable. Thermal inkjet (TIJ) printing, in particular, employs an open-atmosphere printhead design (nozzle openings are open to the atmosphere and do not have valve seals at the openings that allow ink pressurization). TIJ printing has historically suffered from poor performance during intermittent printing, where premature drying of the ink in and around the nozzles occurs due to decap time (i.e., waiting time before printing), especially in cold, dry environments.

[0165] The present disclosure provides a method for forming a printed image by applying any of the inkjet inks of the present disclosure in one or more embodiments to the surface of a substrate using a thermal inkjet printhead and drying the inkjet ink. The use of the inkjet inks described herein overcomes the short decap time problems (too rapid solvent loss) typically associated with thermal inkjet processes over a wide temperature and humidity range.

[0166] Any drop-on-demand printhead known to those skilled in the art of inkjet printing can be used as the printing unit in this method, including continuous printheads, thermal printheads, electrostatic printheads, and acoustic printheads. However, thermal printheads (with heat-transducing elements) are preferred. Typical parameters, such as print resolution, print speed, printhead pulse warming temperature, drive voltage, and pulse length, can be adjusted depending on the printhead specifications. Printheads generally suitable for use in the methods described herein have droplet sizes ranging from 2 to 80 pL and droplet frequencies ranging from 10 to 100 kHz. For example, high-quality printing can be achieved by setting the drive voltage to 8.0 to 9.5 volts, printing speeds up to 300 feet per minute, pulse warming temperatures between 25°C and 45°C, and pulse lengths between 0.7 and 2.5 microseconds. However, values ​​above or below these stated values ​​may be used and still produce satisfactory printing results. Non-limiting examples of printheads suitable for use in the disclosed methods include the HP45Si printer cartridge manufactured by Hewlett Packard or the FUNAI TIJ cartridge manufactured by Funai Co.

[0167] After application, the inkjet ink is dried. In some embodiments, the applied inkjet ink may be dried by applying external heat, for example, using a heater. However, it is preferred not to apply external heat to accelerate or speed up drying. Therefore, in a preferred embodiment, the applied inkjet ink is dried by drying under ambient conditions for 30 seconds or less, preferably 25 seconds or less, more preferably 20 seconds or less, even more preferably 15 seconds or less, and even more preferably 10 seconds or less, without the use of an external heat source such as a heater. The drying time may be extended or shortened based on the ambient temperature and humidity. Furthermore, the method of the present disclosure does not require energy curing (e.g., ultraviolet curing or electron beam curing). Once the applied ink is deemed dry, a further coating of inkjet ink may be applied, or any other processing steps known to those skilled in the art may be performed, as needed.

[0168] It should also be recognized that in the methods described herein, substrate surface treatments such as corona treatment, atmospheric plasma treatment, and flame treatment may optionally be employed prior to application of the inkjet ink to improve characteristics of the printed product, such as, for example, ink adhesion. The parameters of such substrate surface treatments may vary widely depending on the material of the substrate to be printed, the particular inkjet ink used, the printing method applied, and the desired properties and use of the printed product. [Example]

[0169] The following examples are intended to more fully illustrate ink-jet ink embodiments of the present disclosure, but are not intended to limit the scope of the claims.

[0170] [Example] (material) EB Acetate is ethylene glycol monobutyl ether acetate, and PM acetate is propylene glycol methyl ether acetate, both available from Eastman. PINECRYSTAL KE-311 is a glycerol ester of hydrogenated rosin, and PINECRYSTAL KE-359 is a pentaerythritol ester of hydrogenated rosin, both of which are available from Arakawa Chemical Industries, Ltd. PINECLEAR 4306A and PINEREZ 2308A are both pentaerythritol esters of stabilized rosin and are available from Lawter, Inc. FILTREZ 3305 is a maleic acid modified rosin ester, also available from Lawter, Inc. DERTOPHENE T105 is a terpene phenolic resin available from DRT. PHENOLITE TD-2090 is a phenolic novolac resin available from DIC Corp. JONCRYL 680 is an acrylic resin available from BASF. VALIFAST BLACK 3830 is a colorant containing Solvent Black 27 and is available from Orient Chemical Industries Co., Ltd. KF-859 is an amine-modified silicone available from Shin-Etsu Chemical Co.

[0171] (Inkjet ink example) Examples of inkjet inks are shown in Table 1. The amount of each component is expressed as a weight percentage based on the total weight (100%) of the inkjet ink. * indicates that the example is a comparative example.

[0172] Preparation method The inks were prepared in the following manner: Rosin resin, organic solvent, and other ingredients such as amine and surfactant were mixed with a magnetic stir bar until completely dissolved. The dye was added to the mixture and mixed for 30 minutes. Printing results using these inks are shown in the table below. The inks were then evaluated as described below.

[0173] (Evaluation method for inkjet ink) Preparation of print samples Each example inkjet ink was evaluated in a HAS TIJ printer using a Hewlett Packard HP45Si printer cartridge, which was housed in an Espec EPL-3H constant temperature and humidity chamber.

[0174] Decap time evaluation The printing conditions used to evaluate the decap time were as follows: -Printing substrate: plain (uncoated) paper -Print resolution: 300dpi x 300dpi (vertical x horizontal) -Printing speed: 7m / min - Pulse width: 1.8μs -Voltage: 8.6V -Pulse warming: Off Print Image: 100% duty cycle (monochrome bitmap) (see, for example, Figures 1A-1C). The image is 0.5 inches high and 2.7 inches long. -Printing environment: 10°C (50°F) and 30% relative humidity, or 35°C (95°F) and 85% relative humidity

[0175] An image containing a sequence of numbers was printed, and the resulting printed image was verified to be free of missing or unclear lines (indicative of clogged or missing nozzles). After verification, the printhead was decapped for a specified period of time (1 minute, 3 minutes, 5 minutes, 10 minutes, 15 minutes, 30 minutes, 45 minutes, or 60 minutes), and then the same image was reprinted. The reprinted image (after the specified period of time) was verified to determine whether missing or unclear lines had occurred. If no missing or unclear lines had occurred, the inkjet ink was given a decap rating of "good" for that time interval. If 1 to 10 missing or unclear lines occurred during the tested time interval, but the occurrence did not significantly affect the clarity or readability of the image, the inkjet ink was given an "acceptable" decap rating for that time interval. If more than 10 missing lines occurred during the tested time interval, or if clarity and / or readability was significantly impaired, the inkjet ink was classified as "poor" for that time interval. A suitable / desirable inkjet ink is one that achieves a decap classification of "acceptable" or "good" when decapped (i.e., exposed to air) at each time interval and environmental condition tested.

[0176] [Table 1]

[0177] [Table 2]

[0178] [Table 3]

[0179] [Table 4]

[0180] Inkjet ink performance From Table 2, rosin resin with an acid value of less than 22 mg KOH / g and a hydroxyl value of 40 mg KOH / g or less, ethanol, and a Hildebrand solubility parameter of 11 cal 1 / 2 cm -3 / 2 It can be seen that the combination of a co-solvent with a rosin resin having an acid value of less than 22 mg KOH / g but a hydroxyl value of 43 mg KOH / g, as in the inkjet ink of Example 5, exhibited significant effects in terms of continuous printing stability and decap time at different temperatures and humidities (Examples 1 to 2 and Examples 10 to 16). Conversely, the inkjet ink prepared by incorporating a rosin resin having an acid value of less than 22 mg KOH / g but a hydroxyl value of 43 mg KOH / g exhibited poor decap behavior. The inkjet inks of Examples 3 and 4, which were prepared by incorporating a rosin resin having an acid value of more than 22 mg KOH / g, exhibited acceptable decap performance at 35°C and 85% humidity, but performed poorly under the lower temperature and drier conditions of 10°C and 30% humidity. A co-solvent with a Hildebrand solubility parameter of 11 cal 1 / 2 cm -3 / 2 An inkjet ink formulated with more than 2-propanol also had poor decap performance (Example 17).

[0181] Regarding the amount of rosin resin, it was found that excellent decap behavior was achieved when the blending amount was in the range of 1 to 5 wt % and the co-solvent concentration was in the range of 2.5 to 10 wt % (Examples 1 to 2 and Examples 10 to 16).

Claims

1. (A) a rosin resin having an acid value of less than 22 mg KOH / g and a hydroxyl value of 40 mg KOH / g or less; (B1) an alcohol, and (B2) Hildebrand solubility parameter is 11 cal 1 / 2 cm -3 / 2 a co-solvent, wherein an ink-jet ink, wherein the weight ratio of the co-solvent (B2) to the rosin resin (A) ((B2):(A)) is 1:1 to 10:1;

2. 2. The ink-jet ink of claim 1, wherein the rosin resin (A) is present in an amount of 0.1 to 10 wt %, based on the total weight of the ink-jet ink.

3. The ink-jet ink according to claim 1 , wherein the rosin resin (A) comprises a modified rosin resin (A1).

4. The ink-jet ink according to claim 3 , wherein the modified rosin resin (A1) comprises a rosin ester.

5. 5. The ink-jet ink according to claim 4, wherein the rosin ester comprises at least one selected from the group consisting of a glycerol ester of hydrogenated rosin, a glycerol-esterified rosin, a pentaerythritol ester of hydrogenated rosin, a pentaerythritol-esterified rosin, a triethylene glycol-esterified rosin, a maleic acid-modified rosin ester, and a methyl-esterified rosin.

6. The ink-jet ink of claim 1, wherein the alcohol (B1) is present in an amount of 75 to 90 wt %, based on the total weight of the ink-jet ink.

7. 2. The ink-jet ink according to claim 1, wherein the alcohol (B1) comprises at least one selected from the group consisting of methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-pentanol, 3-pentanol, and t-amyl alcohol.

8. The ink-jet ink of claim 1 , wherein the alcohol (B1) comprises ethanol.

9. The ink-jet ink of claim 1, wherein the co-solvent (B2) is present in an amount of 1 to 20 wt %, based on the total weight of the ink-jet ink.

10. The ink-jet ink according to claim 1, wherein the co-solvent (B2) is at least one selected from the group consisting of ethylene glycol monobutyl ether acetate, propylene glycol methyl ether acetate, acetone, and cyclohexanone.

11. The ink-jet ink of claim 1 , further comprising (C) a colorant.

12. The ink-jet ink of claim 11, wherein the colorant (C) is present in an amount of 0.1 to 15 wt %, based on the total weight of the ink-jet ink.

13. The ink-jet ink of claim 1 , further comprising (D) a silicone.

14. The ink-jet ink of claim 13, wherein the silicone (D) is present in an amount of 0.001 to 4 wt %, based on the total weight of the ink-jet ink.

15. The ink-jet ink of claim 1, further comprising (E) a pH adjuster in an amount of 0.1 to 5 wt %, based on the total weight of the ink-jet ink.

16. The ink-jet ink of claim 15, wherein the pH adjuster (E) comprises an amine.

17. The ink-jet ink of claim 16, wherein the amine comprises an alkanolamine.

18. 10. A printed article comprising a substrate and the ink-jet ink of claim 1 in dry form disposed on the substrate.

19. 1. A method of forming a printed image on a substrate, comprising: applying the inkjet ink of claim 1 onto the substrate using a thermal inkjet printhead; and drying the ink-jet ink.

Images