Solvent-based inkjet ink

Abstract

An ink-jet ink comprising (A1) a terpene resin and (B) a solvent system comprising (B1) a ketone solvent having a boiling point below 120° C., and (B2) a dioxolane, the ink-jet ink being characterized by extended decap time and long throw distance. A printed article comprising the ink-jet ink in a dry form, and a method of forming a printed image using a thermal ink-jet printhead are also provided.

Description

[Technical Field]

[0001] The present invention relates to a solvent-based inkjet ink, specifically an inkjet ink formulated with (A1) a terpene resin and (B) a solvent system comprising (B1) a ketone solvent having a boiling point below 120°C, and (B2) a dioxolane. [Background technology]

[0002] The "Background" discussion provided herein is intended to generally present the context for the present disclosure. The inventors' work, to the extent described in this Background section, and aspects of the description that may not be considered prior art at the time of filing, are not admitted explicitly or implicitly as prior art to the present invention.

[0003] Thermal inkjet (TIJ) printing is a desirable technology for printing, coding, and marking because it offers higher print resolution at lower cost than competing technologies in the field, such as continuous inkjet (CIJ) processes. In the thermal inkjet printing process, a print cartridge contains a series of small chambers, each containing a heater, which generate ink droplets from the thermal evaporation of the ink solvent. In the jetting process, a resistor is rapidly heated to create a vapor bubble (hence the term "bubble jet"), which subsequently expels a droplet from an orifice. This process is extremely efficient and repeatable, and the latest TIJ printheads for industrial graphics applications can produce uniform droplets of 4 pL or less in volume at frequencies of 36 kHz or greater.

[0004] However, industrial marking and coding routinely require printing essential information, such as personal information, labels, codes, dates (e.g., expiration dates), and traceability information (e.g., production lot) on substrates with complex surfaces, such as radiused, curved, sawtoothed, corrugated, grooved, and / or edged substrates. These complex substrates can introduce large gaps between the printhead and the substrate surface, posing significant challenges for TIJ technology, which has traditionally only been able to operate with a throw distance of approximately 1–2 mm. When ink must travel distances beyond its throw distance capability to reach the substrate surface, inaccuracies and defects in droplet placement result in poor print quality (e.g., lack of clarity, unclearness). Poor image quality is unacceptable for many applications, but is particularly unacceptable for marking and coding essential information. For this reason, despite its other advantages, TIJ technology has not been widely adopted for marking / coding applications because it cannot match the throw distances typically offered by CIJ technology, which range from 5–12 mm.

[0005] Additionally, thermal inkjet printing can suffer from unreliability after periods of non-operation. For example, some inkjet inks suffer from short decap times where solvent loss from prolonged exposure to air in an uncapped printhead can lead to clogging / plugging of the printhead nozzles, thus resulting in unreliable ink jetting and erosion of image quality over time.

[0006] Solvent-based inkjet inks made using specific combinations of binder resins and volatile organic solvents selected from C1-C4 alcohols, C3-C6 ketones, C3-C6 esters, and C4-C8 ethers have previously been reported to have acceptable decap times and high adhesion to non-porous plastics (see U.S. Patent No. 6,223,629, which is incorporated herein by reference in its entirety). However, such ink systems only printed at a throw distance of 1 mm, and no improvement in throw distance was reported. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] US Patent Application Publication No. 2018 / 0251650 Summary of the Invention [Problem to be solved by the invention]

[0008] In view of the foregoing, there is a need for inkjet inks that have extended decap times and can print at long throw distances (e.g., 8-15 mm).

[0009] Therefore, one object of the present invention is to provide novel ink-jet inks that meet these criteria. Another object of the present disclosure is to provide novel printed materials that include the dried form of inkjet inks. Another object of the present disclosure is to provide a novel method for forming a printed image on a substrate by applying and drying an inkjet ink onto the substrate. [Means for solving the problem]

[0010] These and other objects have been achieved by the inventors' discovery, as will become apparent from the detailed description below, that the combination of a terpene resin, a ketone solvent having a boiling point below 120°C, and a dioxolane provides an inkjet ink characterized by extended decap times and long flight times, e.g., 8-15 mm.

[0011] Thus, the present invention provides the following: (1) An inkjet ink comprising (A1) a terpene resin and (B) a solvent system comprising (B1) a ketone solvent having a boiling point less than 120°C, and (B2) a dioxolane. (2) The ink-jet ink according to (1), wherein the terpene resin (A1) is present in an amount of 0.1 to 10% by weight based on the total weight of the ink-jet ink. (3) The ink-jet ink according to (1) or (2), wherein the terpene resin (A1) is a homopolymer produced from α-pinene. (4) The ink-jet ink according to any one of (1) to (3), wherein the ketone solvent (B1) is present in an amount of 1 to 90% by weight based on the total weight of the ink-jet ink. (5) The ink-jet ink according to any one of (1) to (4), wherein the ketone solvent (B1) is methyl ethyl ketone. (6) The ink-jet ink according to any one of (1) to (5), wherein the dioxolane (B2) is present in an amount of 2 to 90% by weight based on the total weight of the ink-jet ink. (7) The ink-jet ink according to any one of (1) to (6), wherein the weight ratio of the dioxolane (B2) to the ketone solvent (B1) ((B2):(B1)) is 0.05:1 to 30:1. (8) The ink-jet ink according to any one of (1) to (7), wherein the weight ratio of the dioxolane (B2) to the terpene resin (A1) ((B2):(A1)) is 5:1 to 100:1. (9) The ink-jet ink according to any one of (1) to (8), wherein the solvent system (B) further contains (B3) a glycol ether. (10) The ink-jet ink according to (9), wherein the glycol ether (B3) is present in an amount of 0.1 to 20% by weight based on the total weight of the ink-jet ink. (11) The ink-jet ink according to any one of (1) to (10), wherein the solvent system (B) further contains (B4) an alcohol solvent. (12) The ink-jet ink according to (11), wherein the alcohol solvent (B4) is present in an amount of 0.1 to 20% by weight based on the total weight of the ink-jet ink. (13) The inkjet ink according to any one of (1) to (12), further comprising (A2) a terpene phenol resin. (14) The ink-jet ink according to (13), wherein the terpene phenol resin (A2) is present in an amount of 0.1 to 10% by weight based on the total weight of the ink-jet ink. (15) The ink-jet ink according to any one of (1) to (14), further comprising (C) a surfactant. (16) The ink-jet ink according to (15), wherein the surfactant (C) is present in an amount of 0.001 to 4% by weight based on the total weight of the ink-jet ink. (17) The ink-jet ink according to (15) or (16), wherein the surfactant (C) is a polyether-modified silicone. (18) The ink-jet ink according to any one of (1) to (17), further comprising (D) a colorant. (19) A printed matter comprising a substrate and the ink-jet ink according to any one of (1) to (18) in a dried form disposed on the substrate. (20) A method for forming a printed image on a substrate, the method comprising applying the inkjet ink according to any one of (1) to (18) onto the substrate using a thermal inkjet printhead, and drying the inkjet ink.

[0012] The foregoing paragraphs have been provided by way of a general introduction and are not intended to limit the scope of the claims that follow. The described embodiments, together with further advantages, will be best understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which: [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 shows distance ratings for alphanumeric strings with a "good" rating (clearly readable, clear, well-defined image), an "acceptable" rating (readable and mostly clear, with some blurring or slight loss of edge definition), and a "poor" rating (not readable, lacking clarity, and poorly defined). [Figure 2] FIG. 10 shows decap time ratings with a "good" rating (no missing / unclear lines in the thin-line image), an "acceptable" rating (one or two missing / unclear lines in the thin-line image), and a "poor" rating (three or more missing / unclear lines in the thin-line image). DETAILED DESCRIPTION OF THE INVENTION

[0014] In the following description, it is to be 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.

[0015] The phrase "substantially free," unless otherwise specified, means 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.

[0016] As used herein, the term "optional" or "optionally" means that the subsequently described event(s) may or may not occur, or that the subsequently described ingredient(s) may or may not be present (e.g., 0 wt %).

[0017] 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 carbon atoms, 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. Exemplary cycloalkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, norbornyl, and adamantyl.

[0018] As used herein, the term "fatty" refers to compounds that have a long-chain (straight-chain) hydrophobic moiety composed of hydrogen and generally 8 to 22 carbon atoms, and may be fully saturated or partially unsaturated.

[0019] As used herein, the term "aryl" refers to aromatic groups containing only carbon in the aromatic ring(s), for example, phenyl, biphenyl, naphthyl, anthracenyl, and the like.

[0020] The term "arylalkyl," as used herein, refers to a straight-chain, branched, or cyclic alkyl moiety (as defined above) substituted by an aryl group (as defined above), which itself may be optionally substituted by 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.

[0021] The term "(meth)acrylate" is used herein to refer to both acrylate and methacrylate groups. In other words, the term should be read as if the "meth" is optional. Furthermore, the term "acrylate" is used generally to refer to both acrylic acid-based compounds and acrylic ester-based compounds.

[0022] Throughout this specification, the term "boiling point" (bp) refers to the boiling point of a liquid measured at sea level atmospheric pressure (i.e., 760 mmHg or 1 atmosphere), also referred to as the normal boiling point, unless otherwise specified.

[0023] The term "decap behavior" herein refers to the ability of an inkjet ink to easily eject 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 printer's nozzles no longer fire properly, potentially due to clogging or plugging upon resuming printing. Generally, nozzle(s) can become clogged (i.e., impeded or slowed) or clogged (i.e., blocked, substantially or completely closed) by viscous plugs that form within the nozzle(s) as a result of solvent loss, ink scabbing, and / or kogation of various ink components within and / or around any nozzle. When a nozzle becomes clogged, ink droplets ejected through the nozzle orifice can be misdirected, adversely affecting print quality. When an orifice becomes clogged, it becomes substantially or completely blocked. As a result of a clogged nozzle, ink droplets cannot pass through the affected nozzle. Thus, the measure of a nozzle's failure to fire is any misdirection of ink through the nozzle orifice, or complete blockage, which can be measured by visually inspecting the printed image.

[0024] As used herein, the term "throw distance" is defined as the distance between the printhead and the surface of the substrate that can still be used while achieving the desired print quality.

[0025] Inkjet ink The present disclosure is directed to inkjet inks that have suitable physical and chemical stability at both ambient and printhead operating temperatures, jet reliably, and still dry quickly after being applied to a substrate, while having extended decap times and enabling thermal inkjet printing at long throws, for example, up to 10 mm.

[0026] The inkjet inks of the present disclosure generally comprise the following components: (A1) a terpene resin; and (B) a solvent system comprising (B1) a ketone solvent having a boiling point below 120° C., and (B2) a dioxolane.

[0027] The inkjet inks of the present disclosure may also optionally include one or more of (A2) terpene phenolic resin, (B3) glycol ether and / or (B4) alcohol solvent as part of the solvent system (B), (C) surfactant, (D) colorant, and (E) additives.

[0028] (A) Resin(s) The ink-jet ink of the present disclosure contains a terpene resin (A1). Typically, the terpene resin (A1) is used in an amount of at least 0.1 wt%, preferably at least 0.2 wt%, preferably at least 0.4 wt%, preferably at least 0.6 wt%, more preferably at least 0.8 wt%, even more preferably at least 0.9 wt%, even more preferably at least 1 wt%, and up to 10 wt%, preferably up to 9 wt%, preferably up to 8 wt%, preferably up to 7 wt%, preferably up to 6 wt%, preferably up to 5 wt%, more preferably up to 4 wt%, even more preferably up to 3 wt%, even more preferably up to 2 wt%, based on the total weight of the ink-jet ink.

[0029] The terpene resin (A1) of the present disclosure refers to an oligomer or polymer having at least 95% by weight, preferably at least 96% by weight, more preferably at least 97% by weight, more preferably at least 98% by weight, more preferably at least 99% by weight, even more preferably at least 99.5% by weight, and even more preferably 100% by weight of structural units derived from polymerizable terpene(s). Terpenes are those having a basic skeleton (C5H8) p where p is a positive integer indicating the number of consecutive head-to-tail isoprene units. For example, hemiterpenes (p=1) have a C5H8 backbone, and monoterpenes (p=2) have a C5H8 backbone.10 H 16 The sesquiterpenes (p=3) have the C 15 H 24 For example, it has a skeleton.

[0030] In some embodiments, the terpene resin (A1) is based on a monoterpene monomer unit. The monoterpene may be 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-fenchen, camphene, etc.) (including various stereoisomers thereof), and mixtures thereof. In some embodiments, the monoterpene is a monocyclic monoterpene, with limonene being particularly preferred. In preferred embodiments, the monoterpene is a bicyclic monoterpene, with 3-carene, α-pinene, β-pinene, and camphene being particularly preferred, with α-pinene and / or β-pinene being more preferred, and α-pinene being even more preferred.

[0031] A preferred inkjet ink is formulated with a terpene resin (A1) prepared from the polymerization or oligomerization of α-pinene. As known to those skilled in the art, such terpene resins can be readily obtained, for example, by catalytic polymerization / oligomerization (in solution) of α-pinene monomer, which in turn is typically derived from the fractional distillation of gum and sulfated turpentine obtained from pines such as Pistacia terebinthus, Pinus pinaster, Pinus halepensis, Pinus massoniana, Pinus merkusii, Pinus palustris, Pinus taeda, and Pinus ponderosa.

[0032] In a preferred embodiment, the terpene resin (A1) is a homopolymer made from α-pinene, having an α-pinene content (units derived from α-pinene) of at least 95% by weight, preferably at least 96% by weight, preferably at least 97% by weight, preferably at least 98% by weight, preferably at least 99% by weight, more preferably at least 99.5% by weight, even more preferably 99.9% by weight, and even more preferably 100% by weight, based on the total units (100% by weight) of the terpene resin (A1). The terpene resin (A1) of the present disclosure may contain a small amount of other units than those derived from α-terpene monomers, but the amount of other (e.g., non-terpene) units is preferably less than 5% by weight, preferably less than 3% by weight, preferably less than 1% by weight, more preferably less than 0.5% by weight, even more preferably less than 0.1% by weight, and even more preferably 0% by weight, based on the total units (100% by weight) of the terpene resin (A1).

[0033] In some embodiments, the terpene resin (A1) is a homopolymer made from β-pinene, having a β-pinene content (β-pinene-derived units) of at least 95% by weight, preferably at least 96% by weight, preferably at least 97% by weight, preferably at least 98% by weight, preferably at least 99% by weight, more preferably at least 99.5% by weight, even more preferably 99.9% by weight, and even more preferably 100% by weight, based on the total structural units (100% by weight) of the terpene resin (A1). The terpene resin (A1) of the present disclosure may contain a small amount of other structural units than those derived from β-terpene monomers, but the amount of other (e.g., non-terpene) structural units is preferably less than 5% by weight, preferably less than 3% by weight, preferably less than 1% by weight, more preferably less than 0.5% by weight, even more preferably less than 0.1% by weight, and even more preferably 0% by weight, based on the total structural units (100% by weight) of the terpene resin (A1).

[0034] Both polymeric and oligomeric forms of the terpene resin (A1) can be used herein, including combinations thereof. Typically, the number average molecular weight (M) is at least 330 g / mol, preferably at least 340 g / mol, preferably at least 400 g / mol, preferably at least 450 g / mol, preferably at least 500 g / mol, preferably at least 550 g / mol, preferably at least 600 g / mol, more preferably at least 650 g / mol, even more preferably at least 700 g / mol, even more preferably at least 750 g / mol, and up to 1500 g / mol, preferably up to 1300 g / mol, preferably up to 1100 g / mol, preferably up to 1000 g / mol, more preferably up to 900 g / mol, even more preferably up to 800 g / mol, even more preferably up to 790 g / mol. n ) is used herein.

[0035] The terpene resin (A1) may be in a solid or liquid form at room temperature. When the terpene resin (A1) used herein is in a solid form, it can be classified based on its softening point (SP), for example, according to the ring and ball softening point method. The ring and ball softening point is defined as the temperature at which a disc of the sample held in a horizontal ring is pressed downward by a distance of 1 inch (25.4 mm) under the weight of a steel ball while the sample is heated at a predetermined rate in a glycerol bath. For example, the ring and ball softening point can be determined in accordance with JIS B7410, which is incorporated herein by reference in its entirety. Measurement device: Automatic ring and ball softening point; Tester: ASP-MGK2 (manufactured by MEITECH Company Ltd.); Heating rate: 5°C / min; Heating start temperature: 40°C; Measurement solvent: glycerol. Terpene resins (A1) having a wide range of softening points can be used herein, for example, terpene resins (A1) having a softening point of at least 20°C, preferably at least 22°C, preferably at least 24°C, preferably at least 26°C, preferably at least 28°C, preferably at least 30°C, preferably at least 40°C, preferably at least 50°C, preferably at least 60°C, preferably at least 80°C, preferably at least 100°C, preferably at least 110°C, preferably at least 115°C, more preferably at least 120°C, even more preferably at least 125°C, still even more preferably at least 130°C, and up to 160°C, preferably up to 155°C, preferably up to 150°C, preferably up to 145°C, more preferably up to 140°C, even more preferably up to 138°C, still even more preferably up to 135°C. In a preferred embodiment, the terpene resin (A1) has a softening point of at least 20°C, preferably at least 22°C, more preferably at least 24°C, and up to 50°C, preferably up to 45°C, preferably up to 40°C, more preferably up to 35°C, even more preferably up to 30°C, and even more preferably up to 28°C.

[0036] Bromine number is the amount of bromine (Br2) in grams absorbed by a 100 gram sample and is an indication of the unsaturation of the sample. In some embodiments, the terpene resin (A1) used in the inkjet ink has a Bromine Number of at least 12, preferably at least 15, preferably at least 19, preferably at least 22, more preferably at least 25, even more preferably at least 26, still more preferably at least 27, and up to 35, preferably up to 34, preferably up to 33, more preferably up to 32, even more preferably up to 31, still more preferably up to 30, although terpene resins (A1) (e.g., hydrogenated terpene resins (A1)) having Bromine Numbers above or below these values ​​can also be used in the disclosed inkjet inks.

[0037] The inkjet ink of the present disclosure may contain one type of terpene resin (A1), or a combination of two or more types of terpene resins (A1). Examples of terpene resins (A1) that can be used alone or in combination in the inkjet ink of the present disclosure include PICCOLYTE A115 (Ring-Ball SP=112-118°C, Bromine Number=31.5), PICCOLYTE A125 (Ring-Ball SP=122-128°C, Bromine Number=31.5), PICCOLYTE A135 (Ring-Ball SP=132-138°C, Bromine Number=27), PICCOLYTE A135 PLUS (Ring-Ball SP=132-138°C), PICCOLYTE AO PLUS (oligomer, liquid), PICCOLYTE A25 (Ring-Ball SP=22-28°C), and PINOVA RESIN, each of which is manufactured from high-purity α-pinene and is available from Pinova. 2495 (R&B SP=132-138°C, Bromine Number=27), and PICCOLYTE S25 available from Pinova (manufactured from high purity β-pinene, R&B SP=22-28°C, Bromine Number=19). A particularly preferred terpene resin (A1) for use in the disclosed inkjet inks is PICCOLYTE A25.

[0038] It has been found that terpene resin (A1) provides excellent decap times when used in combination with a ketone solvent (B1) and dioxolane (B2) having a boiling point below 120°C. Without being bound by theory, it is believed that terpene resin (A1) improves the decap behavior of inkjet inks by forming a thin "skin" or film cover within the printhead nozzles, thereby creating a temporary seal that limits or reduces solvent loss during periods of inactivity, although the "skin" can easily be broken once printing operations resume. It is believed that the polarity of terpene resin (A1) is high enough to dissolve the vehicle, but not so high that it interacts too strongly with the solvent system to prevent "skin" formation.

[0039] In addition to the terpene resin (A1), the inkjet ink disclosed herein may optionally contain a terpene phenolic resin (A2). When used, the terpene phenolic resin (A2) is at least 0.1 wt.%, preferably at least 0.2 wt.%, preferably at least 0.4 wt.%, preferably at least 0.6 wt.%, more preferably at least 0.8 wt.%, even more preferably at least 0.9 wt.%, and even more preferably at least 1 wt.%, based on the total weight of the inkjet ink, and may be used in an amount up to 10 wt.%, preferably up to 9 wt.%, preferably up to 8 wt.%, preferably up to 7 wt.%, preferably up to 6 wt.%, preferably up to 5 wt.%, more preferably up to 4 wt.%, even more preferably up to 3 wt.%, and even more preferably up to 2 wt.%. Preferably, the amount of terpene phenolic resin (A2) (by weight) is equal to or less than the amount of terpene resin (A1) in the inkjet ink. In some embodiments, the inkjet ink is substantially free of terpene phenolic resin (A2).

[0040] Terpene phenolic resins (A2) are copolymer reaction products of one or more phenolic compounds by alkylation with one or more terpenes. As known to those skilled in the art, such resins can be easily obtained by copolymerizing phenolic compounds and terpene monomers under the action of catalysts such as strong acids, metal salts with condensing effects, bleaching earth, Friedel-Crafts catalysts, or strong Lewis acids (e.g., boron trifluoride).

[0041] The terpene phenolic resin (A2) of the present disclosure may contain small amounts of other structural units other than structural units derived from phenolic compounds and structural units derived from terpenes, but the amount of other (e.g., non-phenolic and non-terpene) structural units is preferably less than 5 wt%, preferably less than 4 wt%, preferably less than 3 wt%, preferably less than 2 wt%, more preferably less than 1 wt%, even more preferably less than 0.5 wt%, and still more preferably 0 wt%, based on the total structural units (100 wt%) of the terpene phenolic resin (A2).

[0042] The terpene phenolic resin (A2) can be formed using any terpene having at least one olefinic double bond that can be alkylated with a phenolic compound. In some embodiments, the terpene phenolic resin (A2) is formed using a monoterpene monomer unit. The monoterpene can be 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. In some embodiments, the monoterpene is a monocyclic monoterpene, with limonene being particularly preferred. In a preferred embodiment, the monoterpene is a bicyclic monoterpene, particularly preferably 3-carene, α-pinene, β-pinene, and camphene, more preferably α-pinene and / or β-pinene.

[0043] The phenolic compound has at least one hydroxyl group directly bonded to the phenyl ring. Any monohydric or polyhydric phenolic compound is useful for preparing the terpene phenolic resin (A2) described herein, provided that the phenolic compound has at least two replaceable hydrogen atoms in the ortho and / or para positions relative to at least one hydroxyl group. That is, the phenolic compound should be capable of being polyalkylated (e.g., bisalkylated) with terpenes (multiple terpenes) and therefore should have at least two available ortho / para positions relative to at least one hydroxyl group for alkylation.

[0044] In a preferred embodiment, the phenolic compound is phenol, which is considered the parent unsubstituted phenolic compound (i.e., containing one hydroxyl group directly attached to the phenyl ring and no other substitutions). Alternatively, the phenolic compound may be substituted at up to three positions in addition to the phenolic hydroxyl group, where one, two, or three of the aromatic hydrogens of the phenol are substituted with an equal number of substituents (each independently, a hydroxyl group; C1-C6). 22 Alkyl groups, preferably C2 to C 18 Alkyl groups, more preferably C3 to C 12 Alkyl groups, even more preferably C4 to C9 alkyl groups, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, C1 to C 22 Alkoxy group, preferably C2-C 12 It is substituted with an alkoxy group, more preferably a C3-C6 alkoxy group, such as methoxy; ethoxy and isopropoxy; an aryl group; an arylalkyl group, such as a benzyl group, and a halo group, such as selected from chlorine, bromine, fluorine, and iodine.

[0045] Specific examples of substituted phenol compounds include o-cresol, m-cresol, p-cresol, 2,5-xylenol, 2,3-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, isopropylphenol (e.g., 4-isopropylphenol), tert-butylphenol (e.g., 4-tert-butylphenol), amylphenol (e.g., 4-tert-amylphenol), heptylphenol (e.g., 4-heptylphenol), octylphenol (e.g., o-octylphenol, p-octylphenol, etc.), nonylphenol, Examples of suitable terpene phenolic resins include, but are not limited to, phenols (e.g., 4-(2,4-dimethylheptan-3-yl)phenol), decylphenol, dodecylphenol, bisphenols such as diphenylolpropane (bisphenol-A), phenylphenols (e.g., 3-phenylphenol), cumylphenol, mequinol, benzyloxyphenol, guaiacol, ethoxyphenols (e.g., 4-ethoxyphenol), and polyhydric phenolic compounds such as resorcinol, pyrogallol, catechol, and p-hydroquinone (including mixtures of two or more of the above). Also included are fused-ring phenols such as naphthols (e.g., 1-naphthol, 2-naphthol, etc.) and similar compounds. A preferred terpene phenolic resin (A2) is one formed from the copolymerization of phenol with one or more of α-pinene, β-pinene, and limonene.

[0046] The molecular weight of the terpene phenolic resin (A2) can vary depending on the monomers employed, the reaction conditions, among many other factors, but typically terpene phenolic resins (A2) having a weight average molecular weight (Mw) of at least 400 g / mol, preferably at least 500 g / mol, more preferably at least 600 g / mol, even more preferably at least 700 g / mol, and up to 3000 g / mol, preferably up to 2500 g / mol, more preferably up to 2000 g / mol, even more preferably up to 1500 g / mol, and even more preferably up to 1000 g / mol are used.

[0047] The terpene phenolic resin (A2) can be classified based on its softening point (SP), for example, according to the previously described ring and ball softening point method (for example, according to JIS B7410, which is incorporated herein by reference in its entirety). In some embodiments, the terpene phenolic resin (A2) has a softening point of at least 60°C, preferably at least 80°C, preferably at least 90°C, preferably at least 100°C, preferably at least 105°C, more preferably at least 110°C, even more preferably at least 115°C, even more preferably at least 120°C, and up to 160°C, preferably up to 155°C, preferably up to 150°C, preferably up to 145°C, preferably up to 140°C, more preferably up to 135°C, even more preferably up to 130°C, and even more preferably up to 125°C.

[0048] The hydroxyl value (OHV) is defined as the number of milligrams of potassium hydroxide required to neutralize the acetic acid incorporated during the acetylation of one gram of a chemical containing free hydroxyl groups. Therefore, the hydroxyl value, a measure of the relative hydroxyl content of a terpene phenolic resin (A2), directly correlates with the content of phenolic compounds within the terpene phenolic resin (A2), with a higher hydroxyl value indicating a higher incorporation of phenolic compounds (and a lower terpene incorporation) into the copolymer. 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."

[0049] The hydroxyl value of the terpene phenolic resin (A2) used in the disclosed inkjet inks can vary, for example, from 10 mgKOH / g to 150 mgKOH / g. However, in view of decap behavior and compatibility with the solvent system (B), preferred terpene phenolic resins (A2) have a hydroxyl value of at least 10 mgKOH / g, preferably at least 15 mgKOH / g, preferably at least 20 mgKOH / g, preferably at least 22 mgKOH / g, preferably at least 24 mgKOH / g, preferably at least 25 mgKOH / g, preferably at least 28 mgKOH / g, preferably at least 30 mgKOH / g, preferably at least 32 mgKOH / g, preferably at least 34 mgKOH / g, and more preferably at least and preferably up to 75 mgKOH / g, preferably up to 70 mgKOH / g, preferably up to 65 mgKOH / g, preferably up to 60 mgKOH / g, more preferably up to 55 mgKOH / g, even more preferably up to 50 mgKOH / g, and even more preferably up to 45 mgKOH / g, with a hydroxyl value (OHV) of 20 to 60 mgKOH / g being most preferred.

[0050] Examples of suitable terpene phenolic resins (A2) that can optionally be used alone or in combination in the inkjet herein include YS POLYSTER products such as YS POLYSTER U130 (OHV=25 mg KOH / g; SP=130°C), YS POLYSTER U115 (OHV=30 mg KOH / g; SP=115°C), YS POLYSTER T160 (OHV=60 mg KOH / g; SP=160°C), and YS POLYSTER T145 (OHV=65 mg KOH / g; SP=145°C) available from Yasuhara Chemical Co. Ltd.; and DERTOPHENE T (OHV=20-50 mg KOH / g; SP=95°C; Mw=700 g / mol), DERTOPHENE T (OHV=20-50 mg KOH / g; SP=95°C; Mw=700 g / mol), available from DRT / Pinova. Examples of suitable terpene phenolic resins include, but are not limited to, DERTOPHENE products such as DERTOPHENE T105 (OHV=40 mg KOH / g; SP=105°C; Mw=700 g / mol), DERTOPHENE T115 (OHV=50 mg KOH / g; SP=120°C; Mw=700 g / mol), and DERTOPHENE T160 (OHV=60 mg KOH / g; SP=160°C; Mw=approximately 1000 g / mol). A particularly preferred terpene phenolic resin (A2) is DERTOPHENE T160.

[0051] In addition to the terpene resin (A1) and the optional terpene phenolic resin (A2), the inkjet ink may optionally comprise other binder resins / tackifiers / adhesive substances in an amount of at least 0.1 wt.%, preferably at least 0.5 wt.%, preferably 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 up to 10 wt.%, preferably up to 9 wt.%, preferably up to 8 wt.%, preferably up to 7 wt.%, preferably up to 6 wt.%, more preferably up to 5 wt.%, even more preferably up to 4 wt.%, and even more preferably up to 3 wt.%, based on the total weight of the inkjet ink. Such additional resins, binders, tackifiers, or adhesive substances include, but are not limited to: - rosin resins, such as those derived from gum rosin, wood rosin, and tall oil rosin (whose main components are resin acids such as abietic acid, palustric acid, neoabietic acid, pimaric acid, isopimaric acid, and / or dehydroabietic acid), including rosin resins formed by modifying the aforementioned rosins by esterification, hydrogenation (including partial hydrogenation), dimerization, and / or other modification / functionalization (e.g., by Diels-Alder reaction with unsaturated diacids such as maleic or fumaric acid / anhydride, carboxylic acid reduction to the respective aldehydes / alcohols, double bond isomerization, dehydrogenation, oxidation, disproportionation, etc.);Exemplary rosin resins include: (1) rosin ester resins, such as esters of rosin composed primarily of abietic or pimaric acid-type resin acids reacted with alcohol(s), such as, for example, glycerin, pentaerythritol, ethylene glycol, diethylene glycol, triethylene glycol, methanol, and the like, and optionally hydrogenated or partially hydrogenated, specifically including HARIESTER products available from Harima Chemicals, Inc., STAYBELITE ESTER 10-E and PERMALYN 6110, each available from Eastman, SUPER ESTER A-125, SUPER ESTER A-75, PENSEL D-125, PINECRYSTAL KE-359 available from Arakawa Chemical Industries, Ltd., and FORAL 85, FORAL ESTER A-75, PENSEL D-125, PINECRYSTAL KE-359 available from Pinova, Inc. (2) hydrogenated acidic rosins such as FORAL AX and FORAL DX, available from Pinova, Inc.; (3) partially hydrogenated acidic rosins such as STAYBELITE RESIN-E, available from Eastman Co., and STAYBELITE and STAYBELITE A, available from Pinova, Inc.; (4) dimerized rosins such as POLY-PALE partially dimerized rosin, available from Eastman Co.; and (5) functionalized rosin resins, such as esters of rosin (e.g., glycerol esters) modified with maleic anhydride or rosin subjected to carboxylic acid reducing conditions, specifically LEWISOL 28-M and Abitol-E hydroabietyl alcohol, available from Eastman Co.; - phenolic resins (i.e. copolymers of phenolic compounds and formaldehyde), for example novolac resins such as PHENOLITE TD-2131 and PHENOLITE TD-2090 available from DIC Corp.; polyamide resins, such as VERSAMID 725, 744, 756, 759 available from BASF Japan Ltd., TOHMIDE 90, 92, 394-N available from Sanho Chemical Co. Ltd., and SUNMIDE 550, 554, 615A, 638, 640 available from Evonik; - epoxy resins, including sulfonamide-modified epoxy resins, such as AD-PRO MTS available from Rit-Chem; (Meth)acrylate and styrene / (meth)acrylate resins, such as JONCRYL 63, JONCRYL 67, JONCRYL 586, JONCRYL 611, JONCRYL 682, 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.; - polyurethane resins, such as those formed from the reaction of (i) polyols, including but not limited to polyester polyols, carbonate polyols, such as ethylene glycol, propylene glycol, propanediol, butanediol, polyethylene glycol, polypropylene glycol, polytetrahydrofuran diol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, polyethylene glycol adipate diol, polyethylene glycol succinate diol, poly(3-methyl-1,5-pentanediol adipate) glycol, poly(3-methyl-1,5-pentanediol terephthalate) glycol, with (ii) diisocyanates, including but not limited to 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4-diphenylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate, e.g., PERMAX 200, PERMAX available from Lubrizol; 202, and SANCURE 20025F; - polyvinyl butyral resins, such as PIOLOFORM BN16 and MOWITAL B20H available from Kuraray America, Inc.; - polyhydroxystyrene resins, such as poly(p-hydroxystyrene) from DuPont; vinyl resins, such as UCAR VYHH, VMCH, VMCA, and VAGF available from The Dow Chemical Company, and VINNOL E15 / 45, H14 / 36, E15 / 45M, and E16 / 40A available from Wacker Chemie AG (Germany); - Formaldehyde resins, including sulfonamide-modified formaldehyde resins such as p-toluenesulfonamide formaldehyde resins, melamine formaldehyde resins, and sulfonamide-modified melamine formaldehyde resins; - cellulose ester resins such as cellulose acetate butyrate (CAB-551-0.01) available from Eastman; - as well as polyesters, sulfonated polyesters, gums, cellulose ethers, cellulose nitrate resins, polymaleic anhydride, acetal polymers, styrene / butadiene copolymers, ketone-aldehyde resins, and polyketone resins; - and equivalents, including mixtures thereof.

[0052] In some embodiments, the inkjet ink is substantially free of additional binder resins / tackifiers / adhesive materials, such as those described above, other than the terpene resin (A1) and optional terpene phenolic resin (A2). In some embodiments, the inkjet ink comprises a combination of the terpene resin (A1) and the terpene phenolic resin (A2), preferably substantially free of additional resins, binders, tackifiers, or adhesive materials. In some embodiments, the terpene resin (A1) is the only resin present in the disclosed inkjet ink. In some embodiments, the inkjet ink is substantially free of rosin resins. In some embodiments, the inkjet ink is substantially free of rosin ester resins, partially hydrogenated acidic rosins, dimerized rosins, and other functionalized / modified rosin resins.

[0053] (B) Solvent system In many printing processes utilizing solvent-based inks, particularly in thermal inkjet printing, the selection of an appropriate solvent system can affect the reliability of the printing process, the properties / appearance of the printed ink product, 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 dynamics between the solvent(s) and various inkjet ink components, thus affecting decap behavior, kogation, and / or droplet trajectory, 3) affect the adhesion, rub and scratch resistance, and optical density properties of the printed image, even when the solvent(s) are no longer present or present in reduced amounts after drying, due to interaction forces between the solvent system and other inkjet ink components, 4) affect the drying time after application or the equipment required to dry the applied ink, and / or 5) affect droplet dynamics.

[0054] In light of the above, particularly preferred herein are inkjet inks comprising a solvent system (B) comprising one or more (B1) ketone solvent(s). The inclusion of a ketone solvent (B1) may aid in solvation of the inkjet ink components, provide polarity compatibility with the terpene resin (A1) for desirable decap behavior, and provide the inkjet ink with acceptable volatility for dry time purposes.

[0055] The amount of ketone solvent (B1) used in the inkjet ink may vary widely, for example at least 1 wt.%, preferably at least 3 wt.%, preferably at least 5 wt.%, preferably at least 10 wt.%, preferably at least 15 wt.%, preferably at least 20 wt.%, preferably at least 25 wt.%, preferably at least 30 wt.%, preferably at least 35 wt.%, more preferably at least 40 wt.%, even more preferably at least 45 wt.%, even more preferably at least 50 wt.%, and up to 90 wt.%, preferably up to 85 wt.%, preferably up to 80 wt.%, preferably up to 75 wt.%, more preferably up to 70 wt.%, more preferably up to 65 wt.%, even more preferably up to 60 wt.%, even more preferably up to 55 wt.%, based on the total weight of the inkjet ink.

[0056] Preferred ketone solvents (B1) are those having a boiling point of less than 120° C., preferably less than 115° C., preferably less than 110° C., preferably less than 105° C., preferably less than 100° C., preferably less than 95° C., more preferably less than 90° C., even more preferably less than 85° C., and even more preferably less than 80° C. When a ketone solvent (B1) having a boiling point equal to or less than the above upper limit is used, fast drying times and advantageous decap times can be achieved.

[0057] The ketone solvent (B1) can contain 3, 4, 5, or 6 carbon atoms. Examples of ketone solvents that can be used alone or in combination in the disclosed inkjet inks include, but are not limited to, acetone, methyl ethyl ketone (MEK), 3-pentanone, methyl n-propyl ketone, methyl isopropyl ketone, ethyl isopropyl ketone, and methyl isobutyl ketone, preferably methyl ethyl ketone.

[0058] The solvent system (B) of the disclosed inkjet ink also includes (B2) a dioxolane. Dioxolane (1,3-dioxolane) is a heterocyclic acetal having the chemical formula (CH2)2O2CH2. The inclusion of dioxolane (B2) has surprisingly been found to improve inkjet throw distance, enabling readable images to be produced at throw distances of, for example, 8 to 15 mm. In contrast, inkjet inks described herein that do not include dioxolane fail to provide readable images at throw distances greater than 4 mm.

[0059] Without being bound by theory, it is believed that dioxolane affects flight distance by altering the droplet dynamics of ejected inkjet ink droplets through a combination of density and surface tension coefficients. For example, dioxolane has a relatively high density (1.06 g / mL at 25°C) compared to ketone solvents such as methyl ethyl ketone (0.805 g / mL at 25°C). This higher density is believed to result in inkjet inks with better directionality and stability against air currents, turbulence, and / or vortices within the printing nip that could otherwise adversely affect droplet placement. Additionally, dioxolane has a relatively high surface tension (34.3 mN / m at 25°C) compared to ketone solvents such as methyl ethyl ketone (24.0 mN / m at 25°C). This higher surface tension is believed to result in more spherical and streamlined ink droplets that can travel longer distances while maintaining desired droplet placement. In addition to droplet dynamics, dioxolanes have also been found to be unique solvents with respect to solubility / compatibility with the resin(s) (A) in the disclosed inkjet inks.

[0060] The amount of dioxolane (B2) suitable to achieve the desired throw distance may be at least 2 wt.%, preferably at least 4 wt.%, preferably at least 5 wt.%, preferably at least 10 wt.%, preferably at least 15 wt.%, preferably at least 20 wt.%, preferably at least 25 wt.%, preferably at least 30 wt.%, preferably at least 35 wt.%, more preferably at least 40 wt.%, even more preferably at least 45 wt.%, even more preferably at least 50 wt.%, and may range up to 90 wt.%, preferably up to 85 wt.%, preferably up to 80 wt.%, preferably up to 75 wt.%, preferably up to 70 wt.%, more preferably up to 65 wt.%, even more preferably up to 60 wt.%, and even more preferably up to 55 wt.%, based on the total weight of the inkjet ink.

[0061] In a preferred embodiment, the ketone solvent (B1) and the dioxolane (B2) together constitute the majority of the solvent system (B) used in the inkjet ink, i.e. the combined weight of the ketone solvent (B1) and the dioxolane (B2) may be in the range of at least 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, preferably at least 80% by weight, preferably at least 90% by weight, preferably at least 95% by weight, preferably at least 96% by weight, based on the total weight of the solvent system (B).

[0062] Relative to the ketone solvent (B1), preferred inkjet inks are those having a weight ratio of dioxolane (B2) to ketone solvent (B1) ((B2):(B1)) of from 0.05:1, preferably from 0.07:1, preferably from 0.1:1, preferably from 0.3:1, preferably from 0.5:1, more preferably from 0.7:1, even more preferably from 0.9:1, still more preferably from 1:1, preferably to 30:1, preferably to 25:1, preferably to 20:1, preferably to 15:1, preferably to 10:1, more preferably to 5:1, even more preferably to 3:1, still more preferably to 2:1.

[0063] Relative to the terpene resin (A1), preferred inkjet inks are those having a weight ratio of dioxolane (B2) to terpene resin (A1) ((B2):(A1)) in the range of at least 5:1, preferably at least 10:1, preferably at least 20:1, preferably at least 30:1, preferably at least 40:1, preferably at least 50:1, preferably at least 55:1, more preferably at least 60:1, even more preferably at least 65:1, still more preferably at least 70:1, up to 100:1, preferably up to 95:1, preferably up to 90:1, more preferably up to 85:1, even more preferably up to 80:1, still more preferably up to 75:1.

[0064] The solvent system (B) may also optionally contain a glycol ether (B3) to further improve decap performance without substantially worsening the drying time of the ink. The glycol ether (B3) may be a monoalkyl ether, a dialkyl ether, a monoalkyl monoester ether, or a combination thereof. Preferably, the glycol ether (B3) is a monoalkyl monoester ether, i.e., a glycol compound in which one hydroxyl group is etherified and the other hydroxyl group is esterified. The glycol ether (B3) contains at least 3 carbon atoms, preferably at least 4 carbon atoms, more preferably at least 5 carbon atoms, and even more preferably at least 6 carbon atoms, and may contain up to 12 carbon atoms, preferably up to 10 carbon atoms, and more preferably up to 8 carbon atoms.

[0065] In some embodiments, the solvent system (B) may incorporate a mixture of glycol ethers (B3), for example, a first glycol ether and a second glycol ether in a weight ratio of at least 1:5, preferably at least 1:4, more preferably at least 1:3, even more preferably at least 1:2, still even more preferably at least 1:1, and up to 5:1, preferably up to 4:1, more preferably up to 3:1, and even more preferably up to 2:1.

[0066] Acceptable examples of glycol ethers (B3) that may optionally be included in the disclosed inkjet inks include 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 Examples of suitable ethylene glycol monoisopropyl ether include, but are not limited to, ethylene 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.

[0067] With a view to improving the decap performance of the inkjet ink without significantly extending the ink drying time, preferred glycol ethers (B3) are those having a boiling point of less than 214°C, preferably less than 210°C, more preferably less than 205°C, even more preferably less than 200°C, and even more preferably less than 195°C.

[0068] In light of the above, ethylene glycol mono-n-butyl ether acetate, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol mono-n-propyl ether, and propylene glycol mono-n-propyl ether are preferred, particularly ethylene glycol mono-n-butyl ether acetate.

[0069] If used, glycol ether (B3) may be present in the inkjet ink in an amount of at least 0.1 wt.-%, preferably at least 0.3 wt.-%, preferably at least 0.5 wt.-%, preferably at least 0.7 wt.-%, more preferably at least 1 wt.-%, even more preferably at least 1.5 wt.-%, even more preferably at least 2 wt.-%, and up to 20 wt.-%, preferably up to 15 wt.-%, more preferably up to 10 wt.-%, even more preferably up to 5 wt.-%, and even more preferably up to 3 wt.-%, based on the total weight of the inkjet ink. The weight ratio of ketone solvent (B1) to glycol ether (B3) can be adjusted for the desired drying and decap times, but is typically at least 1:1, preferably at least 2:1, more preferably at least 5:1, even more preferably at least 10:1, even more preferably at least 15:1, and is in the range of up to 50:1, preferably up to 40:1, more preferably up to 30:1, even more preferably up to 25:1, and even more preferably up to 20:1.

[0070] The solvent system (B) may also optionally include (B4) an alcohol solvent, which may be beneficial in promoting solvation of the inkjet ink components and, among other benefits, jettability, especially when a terpene phenolic resin (A2) is used.

[0071] The alcohol solvent (B4) contains at least 1 carbon atom, preferably at least 2 carbon atoms, more preferably at least 3 carbon atoms, and may contain up to 8 carbon atoms, preferably up to 6 carbon atoms, more preferably up to 4 carbon atoms. Preferred alcohol solvents (B4) are those that have a boiling point of less than 120°C, preferably less than 115°C, preferably less than 110°C, more preferably less than 105°C, even more preferably less than 100°C, and even more preferably less than 98°C.

[0072] Suitable examples of alcohol solvents that can be used alone or in combination in the disclosed inkjet inks include, but are not limited to, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-pentanol, 3-pentanol, and t-amyl alcohol, especially 1-propanol.

[0073] When used, the alcohol solvent (B4) may be present in the inkjet ink in an amount of at least 0.1 wt.%, preferably at least 0.3 wt.%, preferably at least 0.5 wt.%, more preferably at least 0.7 wt.%, even more preferably at least 0.9 wt.%, even more preferably at least 1 wt.%, and up to 20 wt.%, preferably up to 15 wt.%, more preferably up to 10 wt.%, more preferably up to 5 wt.%, even more preferably up to 3 wt.%, and even more preferably up to 2 wt.%, based on the total weight of the inkjet ink. Although the amount of alcohol solvent (B4) can be adjusted to provide, for example, the desired level of solvation, preferred inkjet inks are those having a weight ratio of terpene resin (A1) to alcohol solvent (B4) ((A1):(B4)) in the range of at least 1:5, preferably at least 1:4, more preferably at least 1:3, even more preferably at least 1:2, even more preferably at least 1:1, and up to 5:1, preferably up to 4:1, more preferably up to 3:1, and even more preferably up to 2:1.

[0074] Other organic solvents can optionally be utilized as part of the solvent system (B) herein, examples of which include, but are not limited to, ethers (non-glycol ethers) including ethers containing 4 to 8 carbon atoms (e.g., diethyl ether, dipropyl ether, methyl tert-butyl ether, dibutyl ether, dioxane, and tetrahydrofuran), esters including esters having 3 to 8 carbon atoms (e.g., methyl acetate, ethyl acetate, n-butyl acetate, methyl lactate, ethyl lactate), alkanes (e.g., pentane, hexane, and heptane), and the like, as well as mixtures of two or more thereof. When present, other organic solvents can be included in an amount of up to 20 wt %, preferably up to 15 wt %, preferably up to 10 wt %, preferably up to 5 wt %, more preferably up to 4 wt %, even more preferably up to 2 wt %, and even more preferably up to 1 wt %, based on the total weight of the ink-jet ink.

[0075] In preferred embodiments, the inkjet ink is substantially free of solvents having a boiling point above 220°C, preferably above 210°C, more preferably above 200°C, and even more preferably above 195°C. In some embodiments, the inkjet ink is substantially free of ketone solvents having a boiling point above 120°C, examples of which include, but are not limited to, 3-hexanone, methyl n-butyl ketone, and cyclohexanone. In some embodiments, the inkjet ink is substantially free of glycol ether (B3). In some embodiments, the inkjet ink is substantially free of alcohol solvent (B4). In preferred embodiments, the solvent system (B) consists of a ketone solvent (B1), a dioxolane (B2), a glycol ether (B3), and an alcohol solvent (B4).

[0076] In a preferred embodiment, the inkjet ink of the present disclosure is substantially non-aqueous, meaning that no water is added to the inkjet ink other than what may be incidental amounts of moisture from ambient conditions. In such cases, the inkjet ink may have less than 1 wt. % water, preferably less than 0.5 wt. %, preferably less than 0.1 wt. %, more preferably less than 0.05 wt. %, even more preferably less than 0.01 wt. %, and even more preferably 0 wt. % water, based on the total weight of the inkjet ink.

[0077] Surfactant (C) The inkjet ink of the present disclosure can optionally include a (C) surfactant to provide, for example, anti-blocking properties, ink-receptive properties, leveling properties, anti-crater properties, increased surface slip properties, and / or substrate wetting properties, among other benefits, without sacrificing the decap and distance performance of the inkjet ink. If used, the amount of surfactant (C) used is at least 0.001 wt.%, preferably at least 0.005 wt.%, preferably at least 0.01 wt.%, preferably at least 0.015 wt.%, preferably at least 0.02 wt.%, preferably at least 0.04 wt.%, more preferably at least 0.06 wt.%, even more preferably at least 0.08 wt.%, even more preferably at least 0.1 wt.%, and can range up to 4 wt.%, preferably up to 3 wt.%, preferably up to 2 wt.%, preferably up to 1 wt.%, preferably up to 0.8 wt.%, preferably up to 0.6 wt.%, more preferably up to 0.4 wt.%, even more preferably up to 0.3 wt.%, and even more preferably up to 0.2 wt.%, based on the total weight of the inkjet ink.

[0078] Examples of surfactants (C) that can be used herein, either alone or in combination, include, but are not limited to: - polysiloxanes, including organo-modified silicones (e.g., alkyl-, aryl-, and / or arylalkyl-modified silicones), such as SILTECH C-32 available from Siltech Corporation, COATOSIL 1211C and 3573, each 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)), each available from BYK Additives & Instruments; - silicone acrylate copolymers such as KP-541, KP-543, KP-545, KP-550, and KP-575 (acrylic polymers grafted with polydimethylsiloxane side chains, available from Shin-Etsu Chemical Co., Ltd.), and BYK-3550 (available from BYK Japan KK); - polyether-modified silicones, including those which are 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 fatty alkyl side chains; - Fluoropolymers such as FC-4430 and FC-4432 available from 3M Corporation; photocrosslinkable silicone acrylates or silicone polyether acrylates, such as TEGO RAD 2100, TEGO RAD 2200, TEGO RAD 2250, TEGO RAD 2300 (silicone polyether acrylates), available from Evonik Industries, and BYK-UV 3500 and 3530, available from BYK; - polyacrylates, including polyacrylate copolymers and crosspolymers, such as BYK-381 and BYK-361N (polyacrylate copolymers), respectively, available from BYK, and PEMULEN EZ-4U (acrylates / C10-C30 alkyl acrylate crosspolymer) and PEMULEN TR-2 (acrylic acid / C10-C30 alkyl acrylate crosspolymer), respectively, available from Lubrizol; - Gemini surfactants based on acetylenic diols and acetylenic glycols, such as SURFYNOL SEF and DYNOL surfactants available from Evonik Industries; - Polysiloxane-based gemini surfactants such as TEGO TWIN 4100 available from Evonik Industries; - non-ionic polyethers as substrate wetting surfactants, for example, such as TEGO WET 510 (hydrophilic polyether substrate wetting surfactant) available from Evonik Industries; - 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; Alkoxylated C1-C alkoxylated fatty alcohols, including 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), ethylene oxide / propylene oxide copolymers, and alkoxylated alkylphenols, each available from Stepan. 22 ethers such as alcohols and alkyl polyglycosides (APGs), such as those made from the reaction of fatty alcohols with glucose; fatty esters such as ethoxylated and / or propoxylated fatty acids (for example, castor oil containing 2 to 40 mol of ethylene oxide), alkoxylated glycerides (for example, PEG-24 glyceryl monostearate), glycol esters and derivatives, monoglycerides, polyglyceryl esters, esters of polyalcohols, and polysorbates, including sorbitan / sorbitol esters such as sorbitan monolaurate (for example, EMASOL L-10V available from Kao Corporation), and mono-, di-, or tri-fatty acid esterified polysorbates such as TOXIMUL SEE-340 (sorbitan trioleate ethoxylate (20)) available from Stepan; and - Glycosides of fatty alcohols such as PLANTASENS NATURAL EMULSIFIER HE20 (cetearyl glucoside, sorbitan olivate) available from Clariant.

[0079] When surfactant (C) is incorporated into the inkjet ink, a particularly preferred surfactant is polyether-modified silicone. Polyether-modified silicone is a block copolymer having a pendant graft structure, comprising or consisting of (i) a silicone backbone (main chain), (ii) one or more polyether side chains attached to the silicone backbone, and optionally (iii) one or more fatty alkyl side chains attached to the silicone backbone. Thus, as long as at least one polyether side chain is attached to the silicone backbone, this material meets the definition of "polyether-modified silicone," regardless of whether additional side chain types (e.g., fatty alkyl side chains) are also attached to the silicone backbone. Preferably, the polyether-modified silicone has no other side chains other than the polyether side chain(s) and, optionally, the fatty alkyl side chain(s). As referred to herein, the "side chains" are attached to the silicone backbone (main chain) as pendant grafts, rather than as a continuation of the silicone backbone (as is the case with, for example, linear block copolymers of ABA structure), thereby forming branch points on the silicone backbone with side chains extending from the silicone backbone via covalent bonds. Preferred polyether-modified silicones are non-hydrolyzable, i.e., those in which the side chains are attached to the silicone backbone via Si-C bonds.

[0080] <(i) Silicone Backbone> The silicone backbone can be formed by polymerization and / or polycondensation of appropriately functionalized silanes, and can be based on any organosilicon polymer or oligomer (polyorganosiloxane) of various molecular weights, linear or branched, having a polysiloxane backbone structure (silicon atoms are connected via oxygen atoms; -Si-O-Si-), with alkyl, aryl, and / or arylalkyl groups directly bonded to the (tetravalent) silicon atoms. For example, the polyorganosiloxane backbone can be a linear structure, including but not limited to polydimethylsiloxane (dimethicone) backbone (each silicon atom in this backbone is directly bonded to two methyl groups), poly(dimethylsiloxane-co-methylphenylsiloxane) backbone, poly(dimethylsiloxane-co-diphenylsiloxane) backbone, and poly(dimethylsiloxane-co-methylalkylsiloxane) backbone, or a branched structure, specifically including polydimethylsiloxyethyl dimethicone.

[0081] <(ii) Polyether Side Chain> The polyether-modified silicone comprises at least one polyether side chain based on a polyalkylene glycol oligomer or polymer, for example, one formed by 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 such as block copolymers thereof). Preferably, the polyether side chain is a polyethylene glycol or polyethylene glycol-polypropylene glycol copolymer extending from the silicone backbone, and more preferably, the polyether side chain is a polyethylene glycol side chain (formed solely from ethylene oxide (EO)).

[0082] Polyether side chain(s) of various lengths can 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, and even more preferably at least 6 mol, and ranges 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, and even more preferably up to 9 mol, with 3 mol to 10 mol, preferably 4 mol to 9 mol, of ethylene oxide (EO) units per side chain being particularly preferred.

[0083] 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), with specific examples including methyl, ethyl, propyl, and butyl.

[0084] (iii) Fatty Alkyl Side Chains The polyether-modified silicone may optionally be modified with one or more fatty alkyl side chains, such as those containing at least 8 carbon atoms, preferably at least 10 carbon atoms, more preferably at least 12 carbon atoms, and up to 22 carbon atoms, preferably up to 20 carbon atoms, more preferably up to 18 carbon atoms, even more preferably up to 16 carbon atoms, and even more preferably up to 14 carbon atoms. Exemplary 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, and specifically lauryl, myristyl, cetyl, and stearyl, preferably lauryl.

[0085] In some embodiments, the polyether-modified silicone is a block copolymer having pendant graft structures formed from a linear polydimethylsiloxane backbone containing one or more polyether side chains, for example, represented by formula (IA):

[0086] [ka] In formula (IA), o is 0 or 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 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 comprising the polyether side chains 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 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 a polyether-containing group represented by formula (II),

[0087] [ka] In formula (II), w is at least 2, preferably at least 3, and up to 6, preferably up to 5, more preferably up to 4, even more preferably w is 3; n is 0 or at least 1, preferably at least 2, more preferably at least 3, even more preferably at least 4, and is an integer up to 30, preferably up to 20, more preferably up to 10, even more preferably up to 9, even more preferably, n is from 3 to 10; m is an integer of 0 or up to 30, preferably up to 10, preferably up to 9, preferably up to 5, more preferably up to 2, even more preferably up to 1, even more preferably m is 0, and Z is H or an alkyl group having 1 to 4 carbon atoms, preferably H (unblocked).

[0088] In some embodiments, the polyether-modified silicone is a block copolymer having pendant graft structures formed from a branched polydimethylsiloxane backbone containing one or more polyether side chains and one or more fatty alkyl side chains, for example, as represented by formula (IB):

[0089] [ka] In formula (IB), o, p, and A are as defined above; B is a fatty alkyl group, preferably having at least 10 carbon atoms, preferably at least 12 carbon atoms, and up to 18 carbon atoms, preferably at least 16 carbon atoms, preferably at least 14 carbon atoms, including, in particular, lauryl, myristyl, cetyl, and stearyl; q represents the number of constitutional units comprising fatty alkyl side chains 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 up to 50, preferably up to 40, preferably up to 30, more preferably up to 20, even more preferably up to 10, even more preferably up to 5; r represents the branching in the polydimethylsiloxane backbone and is a positive integer, for example up to 50, preferably up to 40, preferably up to 30, preferably up to 20, preferably up to 10, preferably up to 5, more preferably up to 3, even more preferably up to 2, and even more preferably up to 1; x 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 up to 200, preferably up to 150, preferably up to 100, more preferably up to 75, even more preferably up to 50, more preferably up to 30, even more preferably up to 20, even more preferably up to 10, and y is at least 2 and up to 6, preferably 2.

[0090] Suitable examples of polyether-modified silicones that can be used in the disclosed inkjet inks include, but are not limited to, KF-6013 (PEG-9 dimethicone, unblocked, HLB=10.0), KF-6015 (PEG-3 dimethicone, unblocked, HLB=4.5), KF-6017 (PEG-10 dimethicone, unblocked, HLB=4.5), and KF-6038 (lauryl PEG-9 polydimethylsiloxyethyl dimethicone, unblocked, HLB=3.0), each available from Shin-Etsu Chemical Co., Ltd., and BYK-307 (polyether-modified polydimethylsiloxane) available from BYK Additives and Instruments, Inc.

[0091] In some embodiments, the inkjet ink of the present disclosure is substantially free of surfactants (C), such as those listed above.

[0092] (D) Colorant It should be readily understood by those skilled in the art that the optional inclusion of one or more colorants (D) in an inkjet ink can provide a colored ink that can be used for a variety of printing purposes, and that the inkjet ink is not limited to any particular color. Any colorant (D), including dyes, pigments, mixtures thereof, etc., can be used in an inkjet ink to provide a desired color, provided that the colorant (D) can be dissolved or dispersed within 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). Generally, colorant (D) may be used in an amount of at least 0.1 wt.%, preferably at least 0.5 wt.%, preferably at least 1 wt.%, preferably at least 2 wt.%, preferably at least 3 wt.%, more preferably at least 5 wt.%, even more preferably at least 7 wt.%, even more preferably at least 10 wt.%, and up to 20 wt.%, preferably up to 18 wt.%, more preferably up to 16 wt.%, even more preferably up to 14 wt.%, even more preferably up to 12 wt.%, based on the total weight of the inkjet ink.

[0093] The inkjet inks can be formulated with a variety of dyes, with organic dyes, such as OIL BLACK 860 available from Orient Chemical Industries, and metal complex dyes being particularly preferred.

[0094] Ink-jet inks can be formulated with a variety of inorganic and / or organic pigments. In addition to imparting color to the ink-jet ink, such pigments can sometimes improve the lightfastness, weatherability, etc. of the printed image.

[0095] (E) Additive(s) In addition to the components already mentioned, the inkjet ink may also optionally be formulated with various additives (E) to improve various ink properties and performance. For example, the inkjet ink may optionally include one or more of an anti-kogation agent, a stabilizer, a humectant, a security taggant, or other inkjet additive(s) known to those skilled in the art at appropriate levels.

[0096] Manufacturing method Embodiments of the inkjet inks described herein can be prepared by any suitable technique known to those of skill in the art, for example, by combining (A1) a terpene resin and any desired optional ingredients (e.g., (A2) a terpene phenolic resin, (C) a surfactant, (D) a colorant, and / or additives (E)) with a suitable solvent system (B) comprising (B1) a ketone solvent and (B2) a dioxolane and optionally (B3) a glycol ether and / or (B4) an alcohol solvent, in any order, and stirring, agitating, and / or homogenizing at a temperature between 20° C. and 100° C. for a suitable amount of time to form a homogenous solution.

[0097] In one example, the inkjet ink can be prepared by first combining the terpene resin (A1) with the ketone solvent (B1) and dioxolane (B2) and any optional resins (e.g., terpene phenolic resin (A2)), optional alcohol solvent (B4), optional surfactant (C), or other optional additive(s) (E) in a container, followed by stirring for at least 10 minutes, preferably at least 15 minutes, preferably at least 20 minutes, preferably at least 25 minutes, preferably at least 30 minutes, preferably at least 35 minutes, preferably at least 40 minutes, or preferably at least 45 minutes. If a glycol ether (B3) is used, it can be added to the resulting mixture, followed by stirring for at least 10 minutes, preferably at least 15 minutes, preferably at least 20 minutes, or preferably at least 25 minutes. Colorant (D) is then added as the final component with continuous mixing, after which the solution is mixed for at least 10 minutes, preferably at least 15 minutes, preferably at least 20 minutes, preferably at least 25 minutes, preferably at least 30 minutes, preferably at least 35 minutes, preferably at least 40 minutes, preferably at least 45 minutes to obtain the inkjet ink. The resulting inkjet ink can then be placed in a print cartridge, such as a FUNAI TIJ cartridge manufactured by Funai Co., or other printhead suitable for ketone-based inks.

[0098] characteristics The inkjet inks disclosed herein have an extended decap time, as measured by, for example, printing a fine-line image (e.g., a barcode) (1 mm x 1 cm, fine lines, monochrome bitmap), exposing the inkjet ink to air (decapping the ink cartridge) for a specified period of time (e.g., 30 seconds, 1 minute, 10 minutes, 60 minutes, etc.), reprinting the same fine-line image, and comparing the decapped reprinted image with the original image to determine whether the fine-line image has lost any lines / lost clarity. If no lines have lost any clarity / lost clarity over the tested time interval, the inkjet ink is given a decap rating of "good" for that time interval. If one to two lines are lost / lost clarity over the tested time interval, but not enough to significantly affect the clarity or readability of the fine-line image, the inkjet ink is given an "acceptable" decap rating for that time interval. If three or more lines are lost / lost clarity over the tested time interval, the inkjet ink is classified as "poor" for that time interval. Suitable inkjet inks are those that achieve 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.

[0099] The inkjet inks disclosed herein are also characterized by a long throw distance. The throw distance of an inkjet ink can be measured by printing a test pattern at increasing distances between the printhead and the substrate and evaluating the image quality at each distance. This can include printing an image, such as an alphanumeric string, at various throw distances (e.g., 2 mm, 4 mm, 6 mm, 8 mm, and 10 mm) and visually evaluating the image quality of the printed image in terms of image clarity, edge definition, and drop placement accuracy. If the printed image is clearly readable, has well-defined edges, and the drop placement is accurate, the inkjet ink is given a throw distance rating of "good" for the tested throw distance. If the printed image is readable but with some blurring, slight loss of edge definition, and / or slight loss of drop placement accuracy, the inkjet ink is given an "acceptable" throw distance rating for the tested throw distance. If the printed image is not legible, the image lacks clarity, the contours are not well defined, and / or the drop placement is incorrect, the inkjet ink is given a "poor" distance rating for the tested distance. Preferred inkjet inks are those that maintain a "good" or "acceptable" distance rating for distances of at least 1 mm, preferably at least 2 mm, preferably at least 3 mm, preferably at least 4 mm, preferably at least 5 mm, preferably at least 6 mm, preferably at least 7 mm, more preferably at least 8 mm, even more preferably at least 9 mm, still even more preferably at least 10 mm, and up to 15 mm, preferably up to 14 mm, preferably up to 13 mm, preferably up to 12 mm.

[0100] Another advantage of the disclosed inkjet inks is that they can be easily adjusted and tuned for optical density to meet consumer needs, specific application needs, etc. The optical density of the ink can be measured by printing a solid block image (e.g., 1 cm x 10 cm) and taking an optical density reading using a spectrophotometer (e.g., X-rite eXact, Density / TVI mode, sold by X-rite). Because optical density is a measure of the reflected or absorbed light drawn to the printed surface, the optical density value is dimensionless. Inkjet inks that produce images with optical density readings less than 1.90 are considered to yield images with low optical density, while inkjet inks that yield optical density readings of 1.90 or greater are considered to yield images with high optical density. Typical inkjet inks of the present disclosure produce images with optical densities of at least 1.90, preferably at least 2.00, preferably at least 2.10, preferably at least 2.20, preferably at least 2.30, preferably at least 2.40, preferably at least 2.50, and up to 2.70, or preferably up to 2.60, although optical density values ​​above or below these ranges can be produced if desired.

[0101] printed matter 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 articles. While flat substrates are suitable substrates for forming printed articles, a particular advantage of the present disclosure is that the disclosed inkjet inks (with long throw capabilities) enable printed images to be formed on complex three-dimensional substrates, such as radiused, curved, sawtooth, corrugated, grooved, edged substrates, and / or substrates with structured surfaces (e.g., grained surfaces), all of which are notoriously difficult substrates due to the long distances the ink must travel to reach all parts of the complex surface. Printed materials may be suitable in the graphic arts, textile, packaging (e.g., food packaging, pharmaceutical packaging, etc.), lotteries, direct mail, business forms, and publishing industries, examples of which include tags or labels, lottery tickets, publications, packaging (e.g., food packaging, pharmaceutical packaging, blister packs, various other 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, corrugates, point-of-sale displays, etc. Particularly preferred printed materials are those having the dried form of inkjet ink disposed on complex three-dimensional features of the printed material, for example, a printed image disposed on a grooved or corrugated portion of a plastic container or the bottom of a recessed dome shape of a metal can.

[0102] Inkjet inks can be printed onto porous (i.e., permeable) substrates, examples of which include, but are not limited to, uncoated paper, wood, film, corrugated (cardboard / fiberboard), and fabrics (e.g., woven, nonwoven, and foil-laminated fabrics, including, but not limited to, woven fabrics, nonwoven fabrics, and foil-laminated fabrics).

[0103] 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 include substrates comprising polyesters such as polyethylene terephthalate (PET), polyolefins such as biaxially oriented polystyrene (OPS), 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.

[0104] Method for forming a print image In inkjet printing, a desired printed image is created when precise patterns of dots are 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 houses 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 called 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. The firing of the ink droplets is typically under the control of a microprocessor, whose signals are transmitted by electrical traces to the resistor elements, forming 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. In particular, because thermal inkjet (TIJ) is an open-atmosphere printhead design (the nozzle orifice is open to the atmosphere and there is no valve seal at the orifice to allow ink pressurization), TIJ printing has historically suffered from poor performance during intermittent printing, where decap time (print idle time) causes premature drying of the ink in and around the nozzle.

[0105] In one or more embodiments, the present disclosure provides a method for forming a printed image by applying an inkjet ink onto 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 times (too fast rates of solvent loss) typically associated with thermal inkjet processes, while also allowing the inkjet ink to be applied from greater distances than previously achievable with inkjet printing systems.

[0106] The printing unit of the present method can be any drop-on-demand printhead known to those skilled in the art of inkjet printing, including continuous printheads, thermal printheads, electrostatic printheads, and acoustic printheads, with thermal printheads (with a heat transducer) being preferred. Typical parameters, such as print resolution, print speed, printhead pulse warming temperature, drive voltage, and pulse length, can be adjusted according to the printhead's specifications. Printheads generally suitable for use in the methods herein have droplet sizes ranging from 2 to 80 pL and droplet frequencies ranging from 10 to 100 kHz. High-quality prints can be obtained, for example, by setting the drive voltage at 8.0 to 9.5 volts, print speeds up to 300 feet per minute, pulse warming temperatures at 25 to 45°C, and pulse lengths at 0.7 to 2.5 microseconds. However, values ​​above or below these stated values ​​can also be used and still produce satisfactory prints. One non-limiting example of a printhead suitable for use in the disclosed method is the FUNAI TIJ cartridge manufactured by Funai Electric Co., Ltd.

[0107] After application, the inkjet ink is dried. In some embodiments, external heat may be applied to dry the applied inkjet ink, for example, by using a heater. However, it is preferred not to apply external heat to accelerate drying or increase the drying rate. Thus, in a preferred embodiment, drying is achieved by drying the applied inkjet ink under ambient conditions (in air, at about 23° C.) 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. Furthermore, the method of the present disclosure does not require energy curing (e.g., UV or electron beam curing). Once the applied ink is considered dry, further coatings of inkjet ink may be applied, or any processing steps known to those skilled in the art may be performed, if desired.

[0108] It should also be appreciated that in the methods herein, substrate surface treatments such as corona treatment, atmospheric plasma treatment, and flame treatment can optionally be used prior to application of the inkjet ink to improve print properties, such as ink adhesion. The parameters of such substrate surface treatments can vary widely depending on the substrate material to be printed, the particular inkjet ink utilized, the printing method applied, and the desired properties and use of the print.

[0109] The following examples are intended to further illustrate the ink-jet inks and are not intended to limit the scope of the claims. [Example]

[0110] material EB acetate is ethylene glycol mono-n-butyl ether acetate (boiling point 192°C) available from Eastman. PICCOLYTE A25 is a terpene resin (ring-ball SP = 22-28°C) made from α-pinene available from Pinova. DERTOPHENE T160 is a terpene phenolic resin (OHV = 60 mg KOH / g, SP = 160°C, Mw = approximately 1000 g / mol) available from DRT / Pinova. BYK-307 is a polyether-modified polydimethylsiloxane surfactant available from BYK Additives & Instruments. OIL BLACK 860 is an organic dye available from Orient Chemical Industries, Ltd.

[0111] Inkjet ink evaluation method Print sample creation Example inkjet inks were evaluated with FUNAI TIJ cartridges manufactured by Funai Electric Co., Ltd. The inks were evaluated using thermal printing technology associated with Funai Electric Co., Ltd. (software and hardware manufactured by XiJet, carrier manufactured by Kirk Rudy).

[0112] Optical density evaluation The printing conditions used to evaluate optical density were as follows: - Printing substrate: the white area of ​​the Form 2C non-transparency chart, which is a black and white, self-adhesive non-transparency chart having overall dimensions of 7-5 / 8 inches by 10-1 / 4 inches (194 x 260 mm) available from Leneta Company, Inc. - Print resolution: 300dpi x 300dpi (vertical x horizontal) - Pre-fire 500nsec - Dead time 1700nsec - Main fire 1400nsec - Voltage 9.0V - Pulse heating off - Print image; 100% duty (1cm x 10cm, monochrome bitmap, solid block image).

[0113] A solid block print image was printed and the optical density of the image was measured using an X-rite eXact, Density / TVI mode spectrophotometer sold by X-Rite Corporation.

[0114] Decap time evaluation The printing conditions used to evaluate decap time were as follows: - Printing substrate: plain (uncoated) paper - Print resolution: 300dpi x 300dpi (vertical x horizontal) - Pre-fire 500nsec - Dead time 1700nsec - Main fire 1400nsec - Voltage 9.0V - Pulse heating off - Print image; 100% duty (1mm x 1cm, monochrome bitmap, fine line image) (see Figure 2 for an example).

[0115] A fine-line image was printed to verify that the printed image contained no missing or unclear lines (a precursor to clogged or missing nozzles). After verification, the printhead was left decapped for a specified time period (30 seconds, 1 minute, 10 minutes, or 60 minutes), and then the same fine-line image was reprinted. The reprinted fine-line image (after the specified time period) was checked to see if any missing lines / loss of line clarity had occurred. If no missing lines / loss of line clarity had occurred, the inkjet ink was given a decap rating of "good" for that time interval. If one to two lines were missing / lost in clarity over the tested time interval, but not enough to significantly affect the clarity or readability of the fine-line image over the tested time interval, the inkjet ink was given an "acceptable" decap rating for the tested time interval. If three or more lines were missing / lost in clarity over the tested time interval, 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) for each tested time interval.

[0116] Distance evaluation The printing conditions used to evaluate the throw distance were as follows: - Printing substrate: plain (uncoated) paper - Print resolution: 300dpi x 300dpi (vertical x horizontal) - Pre-fire 500nsec - Dead time 1700nsec - Main fire 1400nsec - Voltage 9.0V - Pulse heating off - Tested distance between print head and substrate (flying distance): 2mm, 4mm, 6mm, 8mm, 10mm - Print image; 100% duty (see Figure 1 for example). An alphanumeric string, such as: Kao Collins Inc. 1201 Edison Drive, Cincinnati, OH 45216

[0117] This alphanumeric string was printed onto a substrate at various throw distances to be tested, and the resulting printed images were visually evaluated for image quality at the tested throw distances and scored according to Table 1. A suitable / desirable inkjet ink is one that achieves a throw rating of "good" or "acceptable" for a throw distance of at least 8 mm.

[0118] [Table 1]

[0119] Inkjet ink examples Examples of inkjet inks are shown in Table 2. The amount of each component is expressed as a weight percentage relative to the total weight (100%) of the inkjet ink. * indicates that the example is a comparative example.

[0120] Preparation method To prepare the example inks, the resin(s) and optional surfactants were first combined with the specified combination of methyl ethyl ketone (MEK), dioxolane, and 1-propanol and mixed with a mechanical stirrer for at least 30 minutes. EB acetate was then added to the mixture and mixed for at least 15 minutes. The dye was then added to the mixture and mixed for at least 30 minutes to obtain the inkjet ink. The inkjet ink examples were then evaluated using a Funai TIJ cartridge manufactured by Funai Electric Co., Ltd.

[0121] [Table 2]

[0122] Inkjet ink performance Table 3 shows that the combination of methyl ethyl ketone, dioxolane, and terpene resin provided significant benefits in terms of throw distance and decap time (Examples 1-5, 8, and 9). In contrast, the inkjet ink without dioxolane performed poorly in terms of throw distance, achieving readable images only at short throw distances of 2-4 mm, with unacceptable image quality in the 6-10 mm range (Example 6).

[0123] With regard to the amount of dioxolane, loadings ranging from 20.90 to 81.00 wt% were found to provide long throw and excellent decap behavior (Examples 1-4, 8, and 9). Reducing the amount of dioxolane to 5.90 wt% maintained good decap behavior and resulted in a slight decrease in throw capability (Example 5, 8 mm throw), but was still far superior to inkjet inks lacking dioxolane.

[0124] It was also found that not all resins are compatible with the MEK / dioxolane solvent system, and inkjet inks formulated with terpene phenolic resins, but not terpene resins, suffered from poor decap behavior at each decap time interval tested (Example 7). Furthermore, inks formulated without surfactants (Example 8) or terpene phenolic resins (Example 9) maintained desirable decap and distance performance.

[0125] [Table 3]

[0126] Where numerical limits or ranges are stated herein, the endpoints are included, and all values ​​and subranges within the numerical limits or ranges are specifically included as if expressly written.

[0127] As used herein, the words "a" and "an" and the like mean "one or more."

[0128] The present disclosure also contemplates other embodiments that "comprising," "consisting of," and "consisting essentially of" the embodiments or elements presented herein, whether explicitly stated or not.

[0129] 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.

[0130] All patents and other references cited above are incorporated herein by this reference in their entirety as if fully set forth.

Claims

1. (A1) a terpene resin; (B) a solvent system comprising (B1) a ketone solvent having a boiling point of less than 120°C, and (B2) a dioxolane; 1. An inkjet ink comprising:

2. 2. The ink-jet ink of claim 1, wherein the terpene resin (A1) 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 or 2, wherein the terpene resin (A1) is a homopolymer of α-pinene.

4. The ink-jet ink of any one of claims 1 to 3, wherein the ketone solvent (B1) is present in an amount of 1 to 90 wt %, based on the total weight of the ink-jet ink.

5. The ink-jet ink according to any one of claims 1 to 4, wherein the ketone solvent (B1) is methyl ethyl ketone.

6. The ink-jet ink of any of claims 1 to 5, wherein dioxolane (B2) is present in an amount of 2 to 90 wt%, based on the total weight of the ink-jet ink.

7. 7. The ink-jet ink according to claim 1, wherein the weight ratio of the dioxolane (B2) to the ketone solvent (B1) ((B2):(B1)) is 0.05:1 to 30:

1.

8. 8. The ink-jet ink according to claim 1, wherein the weight ratio of the dioxolane (B2) to the terpene resin (A1) ((B2):(A1)) is 5:1 to 100:

1.

9. The ink-jet ink according to any one of claims 1 to 8, wherein the solvent system (B) further comprises (B3) a glycol ether.

10. The ink-jet ink according to any one of claims 1 to 9, wherein the solvent system (B) further comprises (B4) an alcohol solvent.

11. The ink-jet ink according to any one of claims 1 to 10, further comprising (A2) a terpene phenol resin.

12. The ink-jet ink according to any one of claims 1 to 11, further comprising (C) a surfactant.

13. The ink-jet ink according to claim 12, wherein the surfactant (C) is a polyether-modified silicone.

14. The ink-jet ink according to any one of claims 1 to 13, further comprising (D) a colorant.

15. 1. A method of forming a printed image on a substrate, comprising: applying the inkjet ink of any one of claims 1 to 14 onto the substrate using a thermal inkjet printhead; drying the inkjet ink; A method comprising:

Images