Ink compositions for inkjet printing

Abstract

Ink compositions are provided, particularly inkjet ink compositions for use in inkjet printing, such as drop-on-demand inkjet printing or continuous inkjet printing, that are suitable for producing codes on non-porous substrates. 1~6 Alcohol solvent, C 3~12 The ink composition includes an ester solvent, a siloxane surfactant, and a capping resin selected from rosin resins and terpene phenolic resins. The ink composition has a short dry time combined with a long decap time and / or good latency.

Description

Technical Field

[0001] Related Applications This application claims priority and the benefit of GB 2003258.7, filed on March 6, 2020 (06 / 03 / 2020), the content of which is hereby incorporated by reference in its entirety.

[0002] The present invention relates to ink compositions, particularly ink compositions for use in inkjet printing such as drop-on-demand inkjet printing.

Background Art

[0003] In the fields of industrial codes and marking codes, date and traceability information is directly applied to products and / or packaging. Such marking is often performed using a printer such as an inkjet printer.

[0004] To form a code, image, or text by inkjet printing on a non-porous substrate such as those commonly used in food packaging, it is necessary to "freeze" the ink droplets ejected from the printer immediately after landing on the substrate. By rapidly freezing the droplets, a code, image, or text can be formed from a controlled series of coalesced or non-coalesced, clearly defined droplets. Therefore, freezing is necessary to provide an accurate image.

[0005] Therefore, it is desirable to provide an ink composition that exhibits rapid drying when printed in order to freeze an image on a substrate.

[0006] There are several known methods for freezing dots on a non-porous substrate, including UV curing that induces polymerization inside the ink droplet or dot, providing a specific inkjet substrate, or heating the substrate.

[0007] The "UV curing" method requires the presence of curable monomers and specific conditions. This method requires additional equipment and specific parts.

[0008] The "inkjet substrate" method requires a specific substrate, typically one having a highly absorbent layer that physically absorbs ink droplets, or one having a chemically reactive layer specially selected to react with components present in the ink (see, e.g., US 6,652,085 & US 7,066,590). These methods require a specific additional layer (either porous or reactive) to be applied to the substrate, and specific ink components.

[0009] In the "heated substrate" method, the substrate to be printed on must be heated to a temperature typically in the range of 40-70°C throughout the printing process. When the liquid droplets hit the substrate, their viscosity decreases, and volatile components evaporate, increasing the solid concentration in the ink and causing a rapid increase in ink viscosity. This method requires additional equipment to heat the substrate, and this heating can negatively affect the print head, especially at high printing speeds.

[0010] Quick-drying inks typically do not require additional equipment or processes to provide high-quality printing, especially on non-porous packaging. However, quick-drying inks present several problems. For example, increasing the drying rate of the ink on the substrate increases the evaporation rate of the ink at the cartridge opening and printer nozzles.

[0011] Decapping refers to the time the nozzle cover can be removed and the printer can remain idle until the nozzles stop printing. Decapping time is the printer's idle time before maintenance is required to restore print quality. Decapping time is sometimes also called "open time".

[0012] Latency refers to the time during a print session when the nozzles can remain inactive before initial performance significantly degrades when printing becomes active. For example, latency refers to the time during a print session when the first few drops become irregular or stop printing altogether. Latency problems often result in jagged edges in images and are sometimes called first-drop problems. Latency is sometimes also called "dwell time."

[0013] Inks for coding and marking should preferably have a short drying time, combined with a long decapping time and good latency. [Prior art documents] [Patent Documents]

[0014] [Patent Document 1] US 6,652,085 [Patent Document 2] US 7,066,590 [Patent Document 3] US 9957401 B2 [Overview of the project] [Problems that the invention aims to solve]

[0015] The object of the present invention is to provide an ink composition having at least some of the above-mentioned desirable properties. In particular, the object of the present invention is to provide an ink that exhibits fast drying properties in combination with a long decapping time and good latency.

[0016] An alternative and / or additional object of the present invention is to overcome or address the problems of prior art inkjet ink compositions, or to provide at least a commercially useful alternative. [Means for solving the problem]

[0017] The present invention aims to provide an ink composition, particularly an ink composition for use in inkjet printing such as drop-on-demand inkjet printing, that is suitable for generating codes on non-porous substrates and has a short drying time combined with a long decapping time and / or good latency. Furthermore, the ink of the present invention can provide good end-user characteristics such as adhesion and / or good print quality.

[0018] Therefore, in one embodiment, the present invention is C 1~6 Alcohol solvent, C 3~12 The present invention provides an ink composition comprising an ester solvent, a siloxane surfactant, and a capping resin selected from rosin resins and terpene phenol resins.

[0019] In another embodiment, the present invention provides a printed deposit formed from the ink composition of the present invention. The printed deposit comprises a capping resin and a siloxane surfactant. The printed deposit may contain trace amounts of solvent.

[0020] In this way, the present invention provides a fast-drying solvent-based ink formulation that has good end-user characteristics such as adhesion or image accuracy (e.g., high-resolution barcode images) and / or good print quality such as high image accuracy, along with good decapping and / or latency characteristics.

[0021] While not strictly theoretical, it is proposed that the combination of capping resin, siloxane surfactant, and ester solvent in the ink functions by forming a temporary cap at the nozzle or cartridge opening. This temporary cap prevents or significantly reduces the evaporation of the alcohol solvent when the ink is loaded into the printer. The temporary cap can also prevent unwanted solvent evaporation during printing, such as during continuous inkjet printing, when ink droplets are moving through the air or being collected by the gutter. During printing, the ink still contains sufficient alcohol solvent, providing quick drying for solidifying the image on the substrate. Therefore, the temporary cap provided by the ink components can offer extended latency and / or good decapping characteristics while maintaining a fast drying time on the substrate.

[0022] The ink composition is compatible with the components of inkjet printers such as drop-on-demand inkjet printers or continuous inkjet (CIJ) printers. Preferably, the ink is suitable for use in drop-on-demand (DOD) inkjet printers such as thermal inkjet (TIJ) printers. The ink composition is suitable for direct application to products and / or product packaging to achieve high-quality images.

[0023] These and other aspects and embodiments of the present invention are described in further detail below. [Brief explanation of the drawing]

[0024] [Figure 1] This figure shows an example of drying time tests at 150x600dpi (top) and 200x300dpi (bottom) on a glossy card substrate supplied by TQC sheen, coated with formulation number 11 of Example 2, on a Hiding Power Chart, 301-A. [Figure 2] This figure shows an example of a latency test using formulation number 11 of Example 2. [Figure 3]This figure shows a test message printed at 200x300dpi using formulation number 11 from Example 2 for adhesion testing. [Modes for carrying out the invention]

[0025] The present invention is C 1~6 Alcohol solvent, C 3~12 The present invention provides an ink composition having an ester solvent, a siloxane surfactant, and a capping resin selected from rosin resins and terpene phenol resins.

[0026] A combination of capping resin, siloxane surfactant, and ester solvent in the ink has been proposed to function by forming a temporary cap at the nozzle or cartridge opening. Furthermore, although not strictly theoretical, it has been proposed that the capping resin is transported to the air-ink interface at the nozzle or cartridge opening by the siloxane surfactant. The hydrophobic groups of the siloxane surfactant have been proposed to interact with the hydrophobic functional groups of the capping resin and accumulate at the ink-air interface. The hydrophilic groups of the siloxane surfactant are C 1~6 It interacts with the bulk solvent, which is an alcohol. It has also been proposed that the resin is solubilized by the ester solvent during transport to the air-ink interface. The capping resin, siloxane surfactant, and ester solvent form a barrier at the air-ink interface.

[0027] While not strictly adhering to theory, siloxane surfactants can fix the capping resin through interaction with oxygen groups in the resin. In some cases, siloxane surfactants may have a branched structure that provides multiple interactions with the capping resin. The ester solvent solubilizes the capping resin. As the capping resin moves to the ink-air interface, the ester solvent is transported by the surfactant. Since ester solvents typically have a lower evaporation rate than alcohol solvents, evaporation is absent or limited at the interface, which helps provide a temporary cap that reduces or prevents the evaporation of the alcohol solvent. Thus, the claimed capping resin and siloxane surfactant are proposed to provide extended latency.

[0028] US9957401 B2 discloses an ink comprising an organic solvent, a resin, a surfactant, and a colorant. The objective of this patent is to improve decapping time, and it is proposed that the surfactant be used to organize the air-ink interface to prevent evaporation of the solvent. The resin is described as providing the viscosity and adhesion required for the ink. US9957401 B2 does not disclose the specific combination of solvent, surfactant, and resin required in the present invention. Furthermore, in the drying test method used to test the ink of the present invention, namely 150x600dpi ink claydown, as described later, the drying time of the formulation in US9957401 B2 is more than 2 seconds.

[0029] Preferably, the ink composition described in this specification has a viscosity of about 0.5 to 25 mPa·s at 25°C, more preferably 1 to 22 mPa·s. Preferably, the ink composition described in this specification has a viscosity of less than 25 mPa·s at 25°C, more preferably less than 22 mPa·s. Preferably, the ink composition described in this specification has a viscosity of more than 0.5 mPa·s at 25°C, more preferably more than 1 mPa·s, even more preferably more than 2 mPa·s. The viscosity of the ink composition may be within the range of the upper and lower limits selected from the above-described range. The viscosity of the composition can be measured using a viscometer such as a Brookfield DV-II+ type viscometer.

[0030] Preferably, the ink composition described in this specification has a surface tension of 20 to 50 mN / m, more preferably 21 to 25 mN / m at 24°C. The surface tension of the composition can be measured using a device such as a SITA bubble pressure tensiometer. The bubble lifetime may be about 20 seconds.

[0031] Also, the ink composition may contain water. For example, if present, water may be present at less than 10% by mass based on the total mass of the ink composition, preferably, water is present at less than 5% by mass or less than 1% by mass.

[0032] The ink composition may be a non-aqueous composition.

[0033] C 1~6 Alcohol solvent The ink composition of the present invention contains C 1~6 an alcohol solvent. C 1~6 The alcohol solvent may be a single C 1~6 alcohol solvent, or may be a mixture of two or more C 1~6 alcohol solvents. Preferably, C 1~6 the alcohol solvent is a mixture of two or more C 1~6 alcohols, more preferably, C 1~6 the alcohol solvent is a mixture of exactly two C 1~6 alcohols.

[0034] C 1~6 Alcohol solvents are proposed to provide a short drying time due to their rapid evaporation.

[0035] The drying time of the ink varies depending on room temperature, pressure, humidity, and the amount of ink applied, i.e., the resolution. Preferably, when printing at 200x300dpi, the ink dries in 0.1 to 3 seconds at 22°C, 1.013kPa, and 40% humidity.

[0036] The drying time can be measured by simultaneously printing multiple separate characters onto a glossy card or Melinex substrate and rubbing one character at a time at regular intervals, such as one second, starting immediately after printing. The drying time is the time it takes for the ink to stop bleeding when rubbed.

[0037] C 1~6 The alcohol solvent can be selected from ethanol, isopropanol, n-propanol, isobutanol, n-butanol, cyclohexanol, cyclopentanol, ethylene glycol, propylene glycol, 1-methoxy-2-propanol, or mixtures thereof.

[0038] Preferably, C 1~6 The alcohol solvent is selected from ethanol, 1-methoxy-2-propanol, or a mixture thereof. More preferably, C 1~6 The alcohol solvent is a mixture of ethanol and 1-methoxy-2-propanol.

[0039] C 1~6 The alcohol solvent may be present in an amount of less than 95% by mass, preferably less than 90% by mass, and more preferably less than 87% by mass, relative to the total mass of the ink composition.

[0040] C 1~6 The alcohol solvent may be present in an amount of more than 10% by mass, preferably more than 40% by mass, and more preferably more than 70% by mass, relative to the total mass of the ink composition. For example, C 1~6The alcohol solvent contains more than 45% by mass, more than 50% by mass, more than 55% by mass, more than 60% by mass, or more than 65% by mass of C 1~6 It can exist in alcoholic solvents.

[0041] C 1~6 The alcohol solvent may be present in an amount that is within the upper and lower limits selected from the amounts mentioned above. For example, C 1~6 The alcohol solvent may be present in the ink composition at an amount of 10 to 95% by mass, preferably 40 to 90% by mass, and most preferably 70 to 90% by mass, relative to the total mass of the ink composition.

[0042] In printed sediments, C 1~6 The alcohol solvent has evaporated, at least partially. In this case, C is present in the printed deposit. 1~6 Alcohol solvent is absent, or contains only trace amounts of carbon. 1~6 Sometimes only an alcoholic solvent is present.

[0043] C 1~6 Alcohol solvents are C 3~12 It may have a higher evaporation rate than ester solvents.

[0044] C 1~6 The alcohol solvent has an evaporation rate of less than 4, preferably less than 2. The evaporation rate is measured relative to N-butyl acetate. The evaporation method can be measured by ASTM method D3539-87 (2004), Standard Test Methods for Evaporation Rates of Volatile Liquids by Shell Thin-Film Evaporometer, ASTM International, West Conshohocken, PA, 2004.

[0045] C 1~6 Alcohol solvents are C 3~12 It may have a lower boiling point than the ester solvent.

[0046] C 1~6The alcohol solvent may have a boiling point of 200°C or less, preferably 150°C or less, more preferably 120°C or less, and even more preferably 100°C or less at a pressure of 1.0 bar.

[0047] C 1~6 The alcohol solvent may have a boiling point of 45°C or higher, preferably 50°C or higher, and more preferably 60°C or higher, at a pressure of 1.0 bar.

[0048] C 1~6 Alcohol solvents may have boiling points within upper and lower limits selected from the ranges described above. For example, C 1~6 Alcohol solvents can have boiling points ranging from 60°C to 120°C at a pressure of 1.0 bar.

[0049] C 1~6 If the alcohol solvent is a mixture, the boiling point is determined by the presence of at least one C in the mixture. 1~6 This refers to the individual boiling points of the alcohols, preferably the boiling points of all C in the mixture. 1~6 This refers to the individual boiling points of alcohols. The term "individual boiling point" used here refers to the boiling point of a solvent measured when the solvent is not a mixture.

[0050] C 1~6 If the alcohol solvent is a mixture of two solvents, then one of the C 1~6 The alcohol solvent is the other C in the mixture. 1~6 This will result in a lower boiling point than that of alcohol solvents. 1~6 Low boiling point C of alcohol solvents 1~6 The mass ratio to the alcohol solvent may be 1:1.1 to 1:2.5, preferably 1:1.2 to 1:2.1.

[0051] C 1~6 C of alcohol solvent 3~12 The ratio to the ester solvent may be 90:1 to 70:10, preferably 90:1 to 70:5.

[0052] C 3~12 Ester solvent The ink composition of the present invention, C3~12 Contains ester solvent. 3~12 Ester solvents are single C 3~12 It may also be an ester solvent, and two or more C 3~12 A mixture of ester solvents may also be used.

[0053] C 3~12 Ester solvents are proposed to solubilize the resin while transporting it to the air-ink interface.

[0054] C 3~12 The ester solvent can be selected from ethyl acetate, propyl acetate, butyl acetate, ethyl propionate, propyl propionate, butyl propionate, ethyl butanoate, propyl butanoate, butyl butanoate, ethyl lactate, butyl lactate, γ-lactone or δ-lactone, or mixtures thereof. Preferred C 3~12 The ester solvent is butyl propionate.

[0055] C 3~12 The ester solvent may be present in an amount of 20% by mass or less, preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 6% by mass or less, relative to the total mass of the ink composition.

[0056] C 3~12 The ester solvent may be present in an amount of 0.5% by mass or more, preferably 1% by mass or more, or 3% by mass or more, relative to the total mass of the ink composition.

[0057] C 3~12 The ester solvent may be present in amounts within the upper and lower limits selected from the amounts described above. For example, C 3~12 The ester solvent may be present in the ink composition in an amount of 0.5 to 8% by mass, preferably 1 to 8% by mass, and most preferably 3 to 6% by mass, relative to the total mass of the ink composition.

[0058] When the capping resin is a terpene phenol resin, preferably C 3~12 The ester solvent is present in the ink composition at an amount of 0.5 to 6% by mass, preferably 0.5 to 2.5% by mass, relative to the total mass of the ink composition.

[0059] If the capping resin is rosin resin, preferably C 3~12 The ester solvent is present in the ink composition at an amount of 1 to 8% by mass, preferably 3 to 6% by mass, relative to the total mass of the ink composition.

[0060] In printed sediments, C 3~12 The ester solvent has evaporated, at least partially. In this case, C 3~12 Ester solvents are either absent in the printed deposits or present in trace amounts of C. 3~12 Sometimes only the ester solvent is present.

[0061] C 3~12 Ester solvents are C 1~6 It may have a lower evaporation rate than alcohol solvents.

[0062] C 3~12 The ester solvent has an evaporation rate of less than 1, preferably less than 0.7. The evaporation rate is measured relative to N-butyl acetate. This evaporation method can be measured according to ASTM method D3539-87 (2004), Standard Test Methods for Evaporation Rates of Volatile Liquids by Shell Thin-Film Evaporometer, ASTM International, West Conshohocken, PA, 2004.

[0063] C 3~12 Ester solvents are C 1~6 It may have a higher boiling point than alcohol solvents.

[0064] C 3~12 The ester solvent may have a boiling point of 500°C or less, preferably 400°C or less, more preferably 300°C or less, and even more preferably 200°C or less at a pressure of 1.0 bar.

[0065] C 3~12The ester solvent may have a boiling point of 50°C or higher, preferably 100°C or higher, and more preferably 140°C or higher, at a pressure of 1.0 bar.

[0066] C 3~12 Ester solvents may have boiling points within upper and lower limits selected from the ranges described above. For example, C 3~12 Ester solvents can have boiling points ranging from 100°C to 200°C at a pressure of 1.0 bar.

[0067] C 3~12 If the ester solvent is a mixture, the boiling point is determined by the presence of at least one carbon in the mixture. 3~12 This refers to the individual boiling points of the esters, preferably the boiling points of all C in the mixture. 3~12 This refers to the individual boiling points of the esters. The term "individual boiling point" used here refers to the boiling point of the solvent measured when the solvent is not a mixture.

[0068] Capping resin The ink composition of the present invention comprises a capping resin selected from rosin resin and terpene phenol resin. Preferably, the capping resin is hydrophobic.

[0069] As used in this application, the term hydrophobic refers to a resin in which interaction with oil or other hydrophobic solvents is thermodynamically more favorable than interaction with water and other polar substances. For example, the hydrophobic resin may be charge-neutral or nonpolar.

[0070] Suitable rosin resins include esters of hydrogenated rosin, such as pentaerythritol rosin resins (e.g., Foralyn 110, Pentaerythritol HE, Foral 105-E, Permalyn 6110, Permalyn 5110, Pinecrystal KE-359 (Arakawa Chemical Industries, Ltd.), Hydrogral P (DRT), Sylvalite RE 100L (Kraton), Sylvalite RE 110L (Kraton), Sylvatac RE 100 (Kraton)) and glycerol ester hydrogenated rosin resins (e.g., Staybelite Ester 10-E, Foralyn 90, or Foralyn 85-E). Preferably, the rosin resin is an ester of hydrogenated rosin, such as pentaerythritol ester of hydrogenated rosin.

[0071] Suitable terpene phenol resins include hydrogenated terpene phenol resins and terpene phenol resins produced by copolymerization reactions of terpenes (e.g., α-pinene, β-pinene, d-limonene) with phenol or bisphenol. By controlling the stoichiometry of terpenes and phenol, a wide variety of resins can be designed. Examples of suitable terpene phenol resins are Dertophene T, Polyster U115, and Polyster UH115. Preferably, the ratio of aliphatic hydrogen to aromatic hydrogen in the terpene phenol resin is 14:1 or higher. The ratio of aliphatic hydrogen to aromatic hydrogen is: 1 It can be measured by 1H-NMR.

[0072] Preferably, the capping resin is solid at 25°C and a pressure of 1.0 bar. In some cases, the capping resin has a softening point of 200°C or less, more preferably 175°C or less, and even more preferably 150°C or less, at a pressure of 1.0 bar.

[0073] The capping resin may have a softening point of 50°C or higher, preferably 80°C or higher, and more preferably 100°C or higher, at a pressure of 1.0 bar.

[0074] The capping resin may have a softening point within the upper and lower limits selected from the ranges described above. For example, the capping resin may have a softening point of 100°C to 150°C at a pressure of 1.0 bar. The softening point can be determined using standard methods such as ASTM E28-18, Standard Test Methods for Softening Point of Resins Derived from Pine Chemicals and Hydrocarbons, by Ring-and-Ball Apparatus, ASTM International, West Conshohocken, PA, 2018.

[0075] Preferably, the capping resin has a molecular weight such as a mass-average molecular weight (Mw) of 400 to 10,000, more preferably 500 to 5,000, and even more preferably 600 to 2,000. Preferably, the capping resin has a molecular weight such as a mass-average molecular weight (Mw) of at least 400, more preferably at least 500, and even more preferably at least 600. Preferably, the capping resin has a molecular weight such as a mass-average molecular weight (Mw) of less than 2,000. The capping resin has a molecular weight such as a mass-average molecular weight (Mw) that is within the upper and lower limits selected from the above ranges.

[0076] Preferably, the capping resin is C 3~12 It has good solubility in ester solvents. For example, C in capping resins. 3~12 The solubility in ester solvents is 20 to 100 grams / 100 grams at 25°C, preferably 20 to 80 grams / 100 grams at 25°C.

[0077] Preferably, the capping resin is C 1~6 It has low solubility in alcohol solvents. For example, C in capping resins. 1~6The solubility in alcohol solvents is less than 10 grams / 100 grams at 25°C, preferably less than 5 grams / 100 grams at 25°C, and more preferably less than 1 gram / 100 grams at 25°C.

[0078] In this way, when the resin accumulates at the cartridge opening or printer nozzle, the low-boiling point alcohol solvent is not carried to the air-ink interface by the resin and therefore does not evaporate.

[0079] Preferably, the capping resin is present in an amount of 0.5 to 10% by mass, more preferably 1.0 to 5.0% by mass, and even more preferably 1.5 to 3% by mass, relative to the total mass of the ink composition.

[0080] Preferably, the capping resin is present in an amount of less than 10% by mass, more preferably less than 5.0% by mass, and even more preferably less than 3% by mass, relative to the total mass of the ink composition. Preferably, the capping resin is present in an amount of more than 0.5% by mass, preferably more than 1% by mass, and even more preferably more than 1.5% by mass, relative to the total mass of the ink composition. The capping resin may be present in an amount within the upper and lower limits selected from the amounts described above.

[0081] Siloxane surfactants The ink composition of the present invention contains a siloxane surfactant. The siloxane surfactant is a surfactant having a siloxane functional group (i.e., a Si-O-Si bond). Preferably, the siloxane surfactant is a polyether-modified siloxane surfactant.

[0082] Siloxane surfactants may have a random structure, a block structure, a comb structure, or a star structure. Preferably, siloxane surfactants have a comb structure. The term comb structure refers to a polymer having a main chain with two or more three-way branching points and linear side chains.

[0083] Examples of suitable siloxane surfactants include commercially available siloxane surfactants, BY16-201 and SF8427 from Dow Corning Toray Co. Ltd., BYK-331 and BYK-333 from BYK-Chemie GmbH, and TEGO Glide 410, TEGO Glide 432, TEGO Glide 435, TEGO Glide 440 and TEGO Glide 450 from Evonik Industries AG.

[0084] In this way, the comb-like branches can function as carriers for capping resin.

[0085] Preferably, the siloxane surfactant has a molecular weight such as a mass-average molecular weight (Mw) of 400 to 20,000, more preferably 1,000 to 15,000. Preferably, the siloxane surfactant has a molecular weight such as a mass-average molecular weight (Mw) of at least 400, more preferably at least 1,000. Preferably, the siloxane surfactant has a molecular weight such as a mass-average molecular weight (Mw) of less than 20,000, more preferably less than 15,000. The siloxane surfactant has a molecular weight such as a mass-average molecular weight (Mw) that is within the upper and lower limits selected from the above range.

[0086] Preferably, the siloxane surfactant is present in an amount of 4.0% by mass or less, more preferably 3.0% by mass or less, and even more preferably 1.5% by mass or less, based on the total mass of the ink composition. The siloxane surfactant is present in an amount of 0.1% by mass or more, preferably 0.2% by mass or more, preferably 0.3% by mass or more, preferably 0.5% by mass or more, preferably 0.7% by mass or more, and even more preferably 0.9% by mass or more, based on the total mass of the ink composition. Preferably, the siloxane surfactant is present in an amount of about 1.0% by mass, based on the total mass of the ink composition. The siloxane surfactant may be present in an amount within the upper and lower limits selected from the amounts described above. For example, the siloxane surfactant may be present in an amount of 0.1 to 1.5% by mass.

[0087] Preferably, the siloxane surfactant has a viscosity of about 100 to 3000 mPa·s, more preferably 200 to 2000 mPa·s, and even more preferably 300 to 1000 mPa·s at 25°C. Preferably, the siloxane surfactant has a viscosity of less than 3000 mPa·s, more preferably less than 2000 mPa·s, and even more preferably less than 1000 mPa·s at 25°C. Preferably, the siloxane surfactant has a viscosity of greater than 100 mPa·s, more preferably greater than 200 mPa·s, and even more preferably greater than 300 mPa·s at 25°C. The viscosity of the siloxane surfactant may be within the upper and lower limits selected from the above ranges. The viscosity of the siloxane surfactant can be measured using a viscometer such as a Brookfield DV-II+ viscometer.

[0088] In some cases, the siloxane surfactant is obtained by pre-diluting it in a solvent. The viscosity of the siloxane surfactant may refer to the viscosity of the pre-diluted solution, or it may refer to the viscosity of the siloxane surfactant before dilution. Preferably, the viscosity refers to the siloxane surfactant before dilution, that is, the viscosity of the siloxane surfactant itself.

[0089] Coloring agents The ink composition may further contain a colorant, such as a dye or pigment. The colorant may be fluorescent, phosphorescent, or pearlescent.

[0090] The dye can be any suitable dye. For example, the dyes include: Solvent Black 27 (Valifast 3830, Orasol X45), Solvent Black 29 (HBDL N36B), Solvent Black 48 (Morfast Black 101), Solvent Yellow 82 (Orasol Yellow 157, Keyfast Spirit Yellow 2GN), Solvent Red 160 (Orasol Red 365), Solvent Red 125 (Orasol Red 363), Solvent Orange 11 (Orasol Orange 247), Solvent Blue 136 (Neptun Blue 755), Solvent Red 122 (Keyfast Spirit Red KL, Keyfast Spirit Red BL), Solvent Red 8 (Keyfast Spirit Red 2BK), Solvent Yellow 62 (Keyfast Spirit Yellow 2RLS), Solvent Yellow 83:1 (Savinyl Yellow RLS), Solvent Blue 44 (Savinyl Blue You can choose from the following colors: GLS, Solvent Yellow 79 (Savinyl Yellow 2GLS), Solvent Orange 62 (Valifast Orange 3209), a mixture of Solvent Orange 62 and Solvent Yellow 21 (Valifast 3210), a mixture of Solvent Red 8 and Solvent Orange 92 (Valifast Red 3306), and Solvent Blue 44 (Valifast Blue 2620).

[0091] The pigment may be in the form of a dispersion in the composition. The pigment may be an inorganic pigment, a metallic pigment, or an organic pigment.

[0092] Preferably, the pigment has an average particle size of less than 1 μm. The average particle size referred to here is the Z-average particle size calculated using dynamic light scattering. This is the intensity-weighted average hydrodynamic size of the particle aggregate.

[0093] For example, inorganic pigments can be selected from titanium dioxide and other titanium oxides, and iron oxides, produced by known processes such as the contact method, furnace method, and thermal method.

[0094] For example, organic pigments can be selected from carbon black, azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, and chelated azo pigments), polycyclic pigments (e.g., phthalocyanines, perylenes, perinones, anthraquinones, quinacridones, dioxazines, thioindigos, isoindolinones, and quinophthalone pigments), dye-based chelated pigments (e.g., basic dye-based chelated pigments and acid dye-based chelated pigments), and aniline black. Carbon black can be produced by known processes such as contact, furnace, and thermal methods.

[0095] Preferably, the organic pigment is carbon black. Suitable carbon blacks for use in black ink include: carbon blacks from Mitsubishi Chemical Corporation, e.g., No. 2300, No. 900, MCF88, No. 33, No. 40, No. 45, No. 52, MA7, MA8, MA100, and No. 2200B; carbon blacks from Columbia Carbon Co., Ltd., e.g., Raven 5750, Raven 5250, Raven 5000, Raven 3500, Raven 1255, Raven 700; carbon blacks from Cabot Corporation, e.g., Regal 400 R, Regal 330 R, Regal 660 R, Mogul E, Mogul L, Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400; and carbon blacks from Degussa, such as Color Black FW 1, Color Black FW 2, Color Black FW 2 V, Color Black FW 18, Color Black FW 200, Color Black S 150, Color Black S 160, Color Black S 170, Printex 35, Printex U, Printex V, Printex 140 U, ​​Special Black 6, Special Black 5, Special Black 4A, Special Black 4, etc.

[0096] Pigments for yellow ink include CI Pigment Yellow 1, CI Pigment Yellow 2, CI Pigment Yellow 3, CI Pigment Yellow 12, CI Pigment Yellow 13, CI Pigment Yellow 14, CI Pigment Yellow 16, CI Pigment Yellow 17, CI Pigment Yellow 73, CI Pigment Yellow 74, CI Pigment Yellow 75, CI Pigment Yellow 83, CI Pigment Yellow 93, CI Pigment Yellow 95, and CI Pigment Yellow. Examples include CI Pigment Yellow 97, CI Pigment Yellow 98, CI Pigment Yellow 109, CI Pigment Yellow 110, CI Pigment Yellow 114, CI Pigment Yellow 128, CI Pigment Yellow 129, CI Pigment Yellow 138, CI Pigment Yellow 150, CI Pigment Yellow 151, CI Pigment Yellow 154, CI Pigment Yellow 155, CI Pigment Yellow 180, CI Pigment Yellow 185, CI Pigment Yellow 139, etc.

[0097] Examples of pigments for magenta ink include CI Pigment Red 5, CI Pigment Red 7, CI Pigment Red 12, CI Pigment Red 48(Ca), CI Pigment Red 488(Mn), CI Pigment Red 57(Ca), CI Pigment Red 57:1, CI Pigment Red 112, CI Pigment Red 122, CI Pigment Red 123, CI Pigment Red 168, CI Pigment Red 184, CI Pigment Red 202, CI Pigment Red 176, CI Pigment Red 254, CI Pigment Red 255, CI Pigment Red 272, CI Pigment Red 254, CI Pigment Orange 64, and CI Pigment Orange 73.

[0098] Examples of pigments for cyan ink include CI Pigment Blue 1, CI Pigment Blue 2, CI Pigment Blue 3, CI Pigment Blue 15:3, CI Pigment Blue 15:34, CI Pigment Blue 16, CI Pigment Blue 22, CI Pigment Blue 60, CI Bat Blue 4, CI Bat Blue 60, CI Pigment Blue 15:2, CI Pigment Blue 15:4, CI Pigment Green 3, CI Pigment Violet 23, and CI Pigment Violet 37.

[0099] Preferably, the organic pigment is selected from CI Pigment Red 176, CI Pigment Red 254, CI Pigment Red 255, CI Pigment Red 272, CI Pigment Red 254, CI Pigment Orange 64, CI Pigment Orange 73, CI Pigment Yellow 83, CI Pigment Yellow 138, CI Pigment Yellow 139, CI Pigment Yellow 151, CI Pigment Yellow 154, CI Pigment Blue 15:2, CI Pigment Blue 15:3, CI Pigment Blue 15:4, CI Pigment Green 3, CI Pigment Violet 23, and CI Pigment Violet 37.

[0100] Preferably, the colorant is present in an amount of 1 to 25% by mass, more preferably 1.5 to 15% by mass, and most preferably 2 to 6% by mass, relative to the total mass of the ink composition.

[0101] Preferably, the colorant is present in an amount of less than 25% by mass, more preferably less than 15% by mass, and even more preferably less than 4% by mass, relative to the total mass of the ink composition. Preferably, the colorant is present in an amount of more than 1% by mass, preferably more than 1.5% by mass, and even more preferably more than 2% by mass, relative to the total mass of the ink composition. The colorant may be present in an amount within the upper and lower limits selected from the amounts described above.

[0102] Polysorbate surfactant The ink composition may further contain a polysorbate surfactant. The polysorbate surfactant is a surfactant obtained by esterifying ethoxylated sorbitan with a fatty acid. Preferably, the polysorbate surfactant is polyethylene glycol sorbitan monostearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan monopalmitate, or polyoxyethylene sorbitan monooleate.

[0103] While not strictly adhering to theory, it is suggested that polysorbate surfactants can rapidly assemble at the ink-air interface, and that siloxane surfactants, capping resins, and ester solvents can assemble to form a temporary cap while simultaneously forming an initial barrier.

[0104] Preferably, the polysorbate surfactant is present in an amount of 4.0% by mass or less, more preferably 3.0% by mass or less, and even more preferably 1.5% by mass or less, based on the total mass of the ink composition. The polysorbate surfactant is present in an amount of 0.1% by mass or more, preferably 0.2% by mass or more, preferably 0.3% by mass or more, preferably 0.5% by mass or more, preferably 0.7% by mass or more, and even more preferably 0.9% by mass or more, based on the total mass of the ink composition. Preferably, the polysorbate surfactant is present in an amount of about 1.0% by mass, based on the total mass of the ink composition. The polysorbate surfactant may be present in an amount within the upper and lower limits selected from the amounts described above. For example, the polysorbate surfactant may be present in an amount of 0.5 to 1.5% by mass.

[0105] Preferably, the polysorbate surfactant has a molecular weight such as a mass-average molecular weight (Mw) of 500 to 5,000, more preferably 1,000 to 3,000, and even more preferably 1,200 to 2,000. Preferably, the polysorbate surfactant has a molecular weight such as a mass-average molecular weight (Mw) of at least 500, more preferably at least 1,000, and even more preferably at least 1,200. Preferably, the polysorbate surfactant has a molecular weight such as a mass-average molecular weight (Mw) of less than 2,000. The polysorbate surfactant has a molecular weight such as a mass-average molecular weight (Mw) that is within the upper and lower limits selected from the above ranges.

[0106] Preferably, the polysorbate surfactant has a viscosity of about 100 to 3000 mPa·s, more preferably 200 to 2000 mPa·s, and even more preferably 300 to 1000 mPa·s at 25°C. Preferably, the polysorbate surfactant has a viscosity of less than 3000 mPa·s, more preferably less than 2000 mPa·s, and even more preferably less than 1000 mPa·s at 25°C. Preferably, the polysorbate surfactant has a viscosity of 100 mPa·s or more, more preferably 200 mPa·s or more, and even more preferably 300 mPa·s or more at 25°C. The viscosity of the polysorbate surfactant may be within the range of upper and lower limits selected from the above amounts. The viscosity of the polysorbate surfactant can be measured using a viscometer such as a Brookfield DV-II+ viscometer.

[0107] In some cases, the polysorbate surfactant is obtained by pre-diluting it in a solvent. The viscosity of the polysorbate surfactant may refer to the viscosity of the pre-diluted solution, or it may refer to the viscosity of the polysorbate surfactant before dilution. Preferably, the viscosity refers to the polysorbate surfactant before dilution, that is, the viscosity of the polysorbate surfactant itself.

[0108] binder The inkjet ink composition and / or printed deposit may further contain a binder. The binder may be referred to as a binder resin. In this case, the binder is different from the capping resin.

[0109] The binder can be selected from any suitable binder, such as polyamide resins, polyurethane resins, acrylic resins, polyvinyl butyral resins, polyesters, phenolic resins, vinyl resins, polystyrene / polyacrylate copolymers, cellulose ethers, cellulose nitrate resins, polymaleic anhydride, acetal polymers, polystyrene / polybutadiene copolymers, polystyrene / polymethacrylate copolymers, sulfonated polyesters, aldehyde resins, polyhydroxystyrene resins, and polyketone resins, as well as mixtures of two or more of these.

[0110] Preferably, the main binder resin is selected from cellulose resin, acrylic resin, vinyl resin, polyamide, polyester, and polyurethane. More preferably, the main binder resin is cellulose resin. Even more preferably, the cellulose resin is cellulose acetate butyrate.

[0111] Preferably, the binder has a molecular weight such as a mass-average molecular weight (Mw) of 1,500 to 50,000, more preferably 10,000 to 50,000, and even more preferably 15,000 to 50,000. Preferably, the binder has a molecular weight such as a mass-average molecular weight (Mw) of at least 1,500, more preferably at least 10,000, and even more preferably at least 15,000. Preferably, the binder has a molecular weight such as a mass-average molecular weight (Mw) of less than 50,000. The binder may have a molecular weight such as a mass-average molecular weight (Mw) within the upper and lower limits selected from the amounts described above.

[0112] Preferably, the binder has good solubility in organic solvents commonly used in solvent-based inks. For example, the solubility of the binder in a solvent is 20 to 100 g / 100 g at 25°C.

[0113] Preferably, the binder is present in an amount of 1.0 to 25% by mass, more preferably 1.5 to 10% by mass, and even more preferably 4 to 6% by mass, relative to the total mass of the ink composition.

[0114] Preferably, the binder is present in an amount of less than 25% by mass, more preferably less than 10% by mass, more preferably less than 8% by mass, and even more preferably less than 6% by mass, relative to the total mass of the ink composition. Preferably, the binder is present in an amount of more than 1.0% by mass, preferably more than 1.5% by mass, and even more preferably more than 4% by mass, relative to the total mass of the ink composition. The binder may be present in an amount within the upper and lower limits selected from the amounts described above.

[0115] Preferably, the binder has good solubility in organic solvents commonly used in solvent-based inks.

[0116] For example, the solubility of a binder in a solvent is 20-100 g / 100 g at 25°C.

[0117] The binder comprises one or more polymers. One or more polymers of the main binder resin may be crosslinkable by a metal crosslinking agent, if present. Crosslinking occurs via one or more suitable coordinating groups on the polymer of the main binder resin. For example, the polymer of the main binder resin may have one or more of the following coordinating groups capable of binding to a metal crosslinking agent: hydroxyl, carboxyl, and amino.

[0118] The coordinating group content is 1.0 to 28% by mass relative to the total mass of the main binder resin, more preferably 2 to 22% by mass, and even more preferably 3 to 17% by mass. Preferably, the coordinating group content is less than 28% by mass, more preferably less than 22% by mass, and even more preferably less than 17% by mass, relative to the total mass of the main binder resin. Preferably, the coordinating group content is greater than 1.7% by mass, preferably greater than 2% by mass, and even more preferably greater than 3% by mass, relative to the total mass of the main binder resin. The coordinating group content of the main binder resin may be within the upper and lower limits selected from the amounts described above.

[0119] Furthermore, the main binder resin can impart desirable viscosity and adhesive properties to the ink.

[0120] In one embodiment, the polymer of the main binder resin has hydroxyl groups for coordinating with a metal crosslinking agent.

[0121] Preferably, the hydroxyl value is 40-330 mgKOH / g, more preferably 50-265 mgKOH / g, and most preferably 100-200 mgKOH / g. Preferably, the hydroxyl value is less than 330 mgKOH / g, more preferably less than 265 mgKOH / g, and most preferably less than 200 mgKOH / g. Preferably, the hydroxyl value is greater than 40 mgKOH / g, more preferably greater than 50 mgKOH / g, and preferably greater than 100 mgKOH / g. The hydroxyl value of the main binder resin may be within the upper and lower limits selected from the above ranges.

[0122] The hydroxyl value is the number of milligrams of potassium hydroxide required to neutralize the acetic acid incorporated when acetylating 1 gram of a chemical substance containing a free hydroxyl group.

[0123] Preferably, the hydroxyl content is 1.0 to 10% by mass relative to the total mass of the main binder resin, more preferably 1.3 to 8% by mass, and even more preferably 2 to 6% by mass. Preferably, the hydroxyl content is less than 10% by mass, more preferably less than 8% by mass, and even more preferably less than 6% by mass relative to the total mass of the main binder resin. Preferably, the hydroxyl content is greater than 1.0% by mass, preferably greater than 1.3% by mass, and even more preferably greater than 2% by mass, relative to the total mass of the main binder resin. The hydroxyl value of the main binder resin may be within the upper and lower limits selected from the above ranges. The hydroxyl content of the binder resin may be within the upper and lower limits selected from the above amounts.

[0124] Hydroxyl content, expressed by mass, refers to the mass percentage (mass%) of hydroxyl groups in grams per 100 grams of substance.

[0125] Metal crosslinking agent The inkjet ink composition and / or printed deposit may further contain a metal crosslinking agent.

[0126] A metal crosslinking agent comprises a metal species capable of forming crosslinks between the polymers of a binder. The metal species of the metal crosslinking agent can form crosslinks between the polymers of the binder resin, if such polymers are present. Any suitable metal species can be used for this purpose.

[0127] Preferably, the metal crosslinking agent is a titanium or zirconium-containing species, preferably a Ti(IV) or Zr(IV)-containing species. A metal crosslinking agent can be used that reacts in solution to form crosslinks between two or more polymers using the metal in the metal crosslinking agent.

[0128] The metal crosslinking agent may be a metal ligand complex, such as a metal cation having an organic ligand. Preferably, the ligand of the metal ligand complex is an organic ligand such as an alkyl phosphate. Preferably, the metal of the metal ligand complex is a metal cation such as Ti(IV) or Zr(IV). For example, the metal crosslinking agent can be selected from titanium acetylacetonate, titanium butyl phosphate, titanium triethanolamine, titanium lactate, zirconium diethyl citrate, zirconium acetate, and zirconium propionate. Preferably, the metal crosslinking agent is titanium butyl phosphate such as Tytan AP100.

[0129] Preferably, the metal crosslinking agent is added in an amount of 0.1 to 5% by mass, more preferably 0.5 to 4% by mass, and most preferably 1.0 to 3.5% by mass, relative to the total mass of the ink composition.

[0130] Preferably, the metal crosslinking agent is added in an amount of less than 5% by mass, more preferably less than 4% by mass, and even more preferably less than 3.5% by mass, relative to the total mass of the ink composition. Preferably, the metal crosslinking agent is added in an amount of more than 0.1% by mass, preferably more than 0.5% by mass, and even more preferably more than 1.0% by mass, relative to the total mass of the ink composition. The metal crosslinking agent may be present in an amount within the upper and lower limits selected from the amounts described above.

[0131] While not strictly adhering to theory, it is thought that metal species crosslink some of the polymer in the binder by interacting with the polymer through coordinating groups on the polymer. Examples of coordinating groups include hydroxyl, carboxyl, and amino.

[0132] While at least some crosslinking can occur in liquid ink, it is preferable that complete crosslinking occurs only when the solvent evaporates. As the solvent evaporates, the concentration of the components increases, and the rate of crosslinking increases. The temporary cap proposed in this invention prevents the evaporation of the solvent, thereby preventing an increase in the concentration of the ink components before printing and reducing the crosslinking that may occur in the liquid ink.

[0133] additives The ink composition and the printed deposit may contain additional components that are common in the art.

[0134] Preferably, the ink composition and the printed deposit may further contain one or more preservatives, humectants, surfactants, plasticizers, conductive salts, wetting agents, adhesion promoters, biocides, and mixtures of two or more thereof.

[0135] conductive additives The ink composition and the printed deposit may further contain a conductive additive. The conductive additive may be any organic salt known in the art.

[0136] Conductive additives for ink compositions are well known in the art, and conductive additives for ink compositions for inkjet inks are particularly well known.

[0137] Preferably, the organic salt is selected from quaternary ammonium salts or phosphonium salts. For example, the organic salt can be selected from tetraethylammonium chloride, tetraethylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium acetate, tetrabutylammonium nitrate, tetrabutylammonium tetrafluoroborate, tetrabutylammonium hexafluorophosphate, tetrabutylphosphonium chloride, and tetrabutylphosphonium bromide. The preferred salt is tetrabutylammonium bromide.

[0138] Preferably, the conductive additive is present in an amount of 0.1 to 5% by mass relative to the total mass of the ink composition.

[0139] Moisturizer The ink composition and the printed deposit may further contain a humectant.

[0140] Suitable humectants include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,4-cyclohexanedimethanol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, glycerol, 1,2,6-hexanetriol, sorbitol, 2-pyrrolidone, 2-propanediol, butyrolacetone, tetrahydrofurfuryl alcohol, and 1,2,4-butanetriol, as well as mixtures of two or more of these. Preferably, the humectant is selected from the group consisting of glycerol, tetrahydrofurfuryl alcohol, polypropylene glycol, and mixtures of two or more of these.

[0141] The ink composition may contain up to 30% by mass of a humectant based on the total mass of the composition. More preferably, the ink composition contains up to 20% by mass of a humectant based on the total mass of the composition.

[0142] Preservatives The ink composition and / or printed deposit may further contain preservatives.

[0143] Suitable preservatives include sodium benzoate, benzoic acid, sorbic acid, potassium sorbate, calcium sorbate, calcium benzoate, methylparaben, and mixtures of two or more of these. The preferred preservative is sodium benzoate.

[0144] The ink composition may contain up to 2% by mass of a preservative based on the total mass of the composition. More preferably, the ink composition contains up to 1% by mass of a preservative based on the total mass of the composition.

[0145] Types of packaging This disclosure further provides a method for printing an image on a substrate, comprising directing a flow of droplets of any embodiment of the ink composition of the present invention onto a substrate, drying the ink droplets, and thereby printing an image on the substrate. An inkjet printer, such as a drop-on-demand inkjet printer or a continuous inkjet printer, can be used in this method. Preferably, a drop-on-demand inkjet printer, such as a thermal inkjet printer, can be used.

[0146] Any suitable substrate can be printed according to the present invention.

[0147] The ink composition of the present invention is particularly suitable for printing on non-porous materials, such as non-porous materials used in food packaging.

[0148] Suitable substrates include blister packs (e.g., for medical products such as tablets), electronic components (e.g., batteries), metallized cans, plastic pots, retort pouches, and flexible plastic films. These substrates can be manufactured from, for example, aluminum, steel, glass, polystyrene, PVC, LDPE, HDPE, polypropylene, PET, nylon, or PVdC.

[0149] Methods and Uses The ink composition is formulated by combining components using methods known in the art.

[0150] The components of the ink composition can be combined by adding them together and stirring using mechanical agitation. In some cases, the components may be added in the following order: ester solvent, capping resin, siloxane surfactant, additional additives, and colorants (e.g., pigment dispersion), followed by an alcohol solvent.

[0151] This disclosure further provides a method for printing an image on a substrate, comprising directing a flow of droplets of an ink composition of any embodiment onto a substrate, drying the ink droplets, and thereby printing an image on the substrate. An inkjet printer, such as a drop-on-demand inkjet printer or a continuous inkjet printer, can be used in this method. Preferably, a drop-on-demand inkjet printer, such as a thermal inkjet printer, can be used.

[0152] The ink composition of the present invention is suitable for printing on non-porous substrates.

[0153] Any suitable substrate can be printed according to the present invention. Examples of substrates that can be printed using the ink composition of the present invention include porous substrates such as uncoated paper, semi-porous substrates such as aqueous coated paper, clay coated paper, silica coated paper, UV overcoated paper, polymer overcoated paper, and varnish overcoated paper, and non-porous substrates such as rigid plastics, polymer films, polymer laminates, metals, metal foil laminates, glass, and ceramics. Paper substrates may be thin paper, roll paper, or cardboard. Plastic, laminate, metal, glass, and ceramic substrates may be in any suitable form, such as bottles or containers, plates, rods, cylinders, etc.

[0154] Advantageously, by using the compositions and methods described herein, at least some of the above-mentioned problems are overcome and / or mitigated, and printed materials of improved quality are provided.

[0155] definition As used herein, the term "printed deposit" refers to the ink composition after it has been printed onto a suitable substrate; that is, the ink composition of the present invention in which at least a portion of the solvent has evaporated.

[0156] As used herein, the term "ink composition" includes inkjet ink compositions suitable for use in inkjet printing. Ink compositions are typically in liquid form and are typically solutions.

[0157] When used in this specification, C 1~6 The term "alcohol solvent" refers to any solvent having at least one hydroxyl functional group (-OH) and 1 to 6 carbon atoms. The solvent may have a linear, branched, or cyclic structure. The solvent may be saturated or unsaturated, and preferably, the alcohol solvent is at least partially saturated.

[0158] When used in this specification, C 3~12 The term ester solvent refers to any solvent having at least one ester functional group (-OC(=O)-) and 3 to 12 carbon atoms. Ester solvents can have linear, branched, or cyclic structures (e.g., lactones). Ester solvents may be saturated or unsaturated, and preferably, the alcohol solvent is at least partially saturated.

[0159] As used herein, the term polymer refers to any substance having repeating units and includes: sugars and their derivatives, e.g., cellulose and its derivatives; addition polymers, e.g., acrylic resins or polyvinyl resins; condensation polymers, e.g., polyurethanes, polyamides and polyesters; and copolymers in which the repeating units are formed from two or more different compounds, e.g., styrene and malean anhydride.

[0160] Decapping refers to the time during which the nozzle cover can be removed and the printer can remain idle until the nozzles stop printing. Decapping time is the idle time of the printer before maintenance is required to restore print quality. Decapping time is sometimes also called "open time".

[0161] Latency refers to the time during a print session when the nozzles can remain inactive before initial performance significantly degrades when printing becomes active. For example, latency refers to the time between prints during a print session before the first few drops become irregular or stop printing altogether. Latency problems often result in jagged edges in images and are sometimes called first-drop problems. Latency is also sometimes referred to as "dwell time."

[0162] Other settings Any compatible combination of the embodiments described above is expressly disclosed herein, as if every combination were explicitly enumerated individually.

[0163] Various further aspects and embodiments of the present invention will be apparent to those skilled in the art in consideration of this disclosure.

[0164] As used herein, “and / or” should be considered a specific disclosure involving each of the two designated features or components, and possibly the other. For example, “A and / or B” should be received as the specific disclosures of (i) A, (ii) B, and (iii) A and B, respectively, as each of them is described separately herein.

[0165] Unless otherwise indicated by the context, the descriptions and definitions of features set forth above are not limited to any particular aspect or embodiment of the present invention, but apply equally to all aspects and embodiments described herein.

[0166] Specific aspects and embodiments of the present invention will now be described, by reference to the above-described figures, as an example. [Examples]

[0167] The following non-limiting examples further illustrate the present invention. All tests were conducted in a laboratory environment at 20°C with a pressure of 1.013 kPa and a relative humidity of 20% to 50%.

[0168] General method Drying time To measure drying time, messages were printed using a Domino G-series printer, an HP 45Si cartridge, and sample slides of the test ink formulation on a glossy card substrate. The glossy card substrate was coated Hiding Power Chart, 301-A, supplied by TQC sheen or Melinex. An example of a message is shown in Figure 1.

[0169] Melinex refers to Melinex 339 sheets (175 microns), a non-porous white polyester substrate supplied by CADILLAC PLASTIC LIMITED.

[0170] The drying time can be tested at 200x300dpi or 150x600dpi.

[0171] Wearing clean gloves, lightly rub a series of crosses with your fingers at one-second intervals immediately after printing the message. Stop the test when the print no longer smudges. The time it takes for the print to stop smudging is the drying time. Repeat this test three times and calculate the average drying time, which will be the drying time for each formulation.

[0172] Latency Latency is defined as the time it takes for print quality to not degrade when printing is stopped, the cartridge is left unattended with the cap removed, and then printing is resumed.

[0173] Latency is tested using a 2D data matrix code, as shown in Figure 3, printed on a sample slide on single-sided 120mg glossy paper (Splendorlux lightweight) using a Domino G Series printer, HP 45Si cartridge, and the ink formulation under test.

[0174] Clean the cartridge thoroughly and take three print samples. This is the starting point, time 0.

[0175] Print samples are taken at predetermined intervals of 10 minutes, 30 minutes, 60 minutes, 90 minutes, 2 hours, and 4 hours. The cartridge is left capped during printing. The quality of the 2D code is evaluated using an Axicon 2D barcode grader compliant with standard PD ISO / IEC TR 29158:2011. Examples of specified characteristics include cell contrast, modulation, reflectance margin, axial and grid non-uniformity, quiet zone, transition ratio, and decodeability.

[0176] A good outcome for latency is a long latency time (i.e., the cartridge can be left uncapped for an extended period).

[0177] (Example 1) Screening of resins containing pigments

[0178] [Table 1]

[0179] All experiments using the resins YS Polyster U115 and Foralyn 110 were based on the varnishes shown in Table 2. The resins were dissolved in a blend of 1-methoxy-2-propanol and butyl propionate in a high-shear rotor stator mixer. Ethanol and CAB binder were added, followed by the remaining components.

[0180] In the experiment, the resin, its quantities, and the amount of butyl propionate were varied.

[0181] [Table 2]

[0182] The amounts of butyl propionate and resin are described in the following examples of formulations. The amount of ethanol in each formulation is adjusted so that the total is 100% by mass.

[0183] Ethanol was obtained from Tennants Distribution Limited as Trade Specified Denatured Alcohol.

[0184] 1-Methoxy-2-propanol was obtained from Sigma-Aldrich, with a purity specification of ≥99.5%.

[0185] Butyl propionate was obtained from Sigma-Aldrich, with a purity specification of ≥98%.

[0186] The resin YS Polyster U115 was obtained as pellets from Yasuhara Chemicals Co., Ltd.

[0187] The resin Foralyn 110 was obtained as pellets from Eastman.

[0188] CAB 551-0.01 was obtained as a powder from Eastman.

[0189] Tytan AP 100 was obtained as a liquid from Borica.

[0190] I obtained the Tego Glide 440 from Evonik.

[0191] The pigment dispersion contained ethanol (as described above), EFKA PX 4320, an acrylic block copolymer-based dispersant containing 50% active ingredient in 2-methoxy-1-methylethyl acetate obtained from BASF, and Mogul E pigment obtained as a powder from Cabot. The quantities are shown in the table.

[0192] [Table 3]

[0193] YS Polyster U115 With YS Polyster U115, various experiments were conducted by changing the resin content itself and the butyl propionate content.

[0194] [Table 4]

[0195] The experiment demonstrates that the resin improves latency in the presence of butyl propionate. Reducing the amount of YS Polyster U115 from 1.8% to 1% while maintaining the amount of butyl propionate at the same 2.5% reduces latency from 1 hour to less than 1 hour. Increasing the amount of YS Polyster U115 from 1.8% to 2% while keeping the amount of butyl propionate constant at 1.5% increases latency from 1 hour to over 2 hours.

[0196] Foralyn 110 We conducted various experiments using Foralyn 110 as the resin.

[0197] [Table 5]

[0198] Formulations 8, 9, and 10 demonstrate that both the reduction of Foralyn 110 and the reduction of butyl propionate reduce latency. When the drying time of formulation 8 was measured, it showed a fast drying time and a long latency time at 200x300dpi.

[0199] (Example 2) Screening of resins containing dyes

[0200] [Table 6]

[0201] Table 6 shows an overview of the capping resins used in this section. The formulations for each experiment are also disclosed below. The resin was dissolved in a blend of 1-methoxy-2-propanol and butyl propionate in a high-shear rotor-stator mixer. Ethanol and CAB binder were added, followed by the addition of the remaining components.

[0202] [Table 7]

[0203] The components of these formulations were obtained in the same manner as in Example 1 by adding the following ingredients.

[0204] The acetone was obtained as Acetone N grade from Tennants Distribution Limited.

[0205] Permalyn® 6110 was obtained as pellets from Eastman.

[0206] Valifast Black 3830 was obtained as a powder from Orient.

[0207] [Table 8]

[0208] Table 8 shows the formulations used in a series of experiments to evaluate the functionality of various components of the formulations. "RH" stands for relative humidity. All formulations contain Permalyn® 6110 as the capping resin, except for formulation number 14, which was removed for comparison. Table 8 summarizes the results of various resolution and drying times (seconds) on different substrates, as well as latency tests.

[0209] Formulation No. 11 contains a capping resin, ethanol and 1-methoxy-2-propanol as the main solvent, butyl propionate, and Tego Glide 440. This formulation provides a drying time of 3 seconds or less and excellent latency of up to 16 hours for all substrates and all resolutions.

[0210] Changing the main solvent from ethanol to acetone (formulation number 12) improves the drying time, but only achieves a latency of about 10 seconds.

[0211] Removing Tego Glide 440 (formulation number 13) prevents high-quality initial printing, making latency testing impossible. The same applies to removing the capping resin (formulation number 14). Removing the crosslinking agent Tytan AP 100 does not significantly affect drying time or latency (formulation number 15).

[0212] [Table 9]

[0213] [Table 10]

[0214] Table 9 shows two formulations using various capping resins, various binders, and various polysorbate surfactants. Table 10 summarizes the results of latency tests at various resolutions, drying times (seconds) on various substrates, and latency tests.

[0215] Both formulations exhibit improved latency with a good drying time.

[0216] (Example 3) Screening of additional surfactants For the screening of additional surfactants, various surfactants with different chemical properties (summarized in Table 11) were studied in the formulations shown in Table 12.

[0217] [Table 11]

[0218] [Table 12]

[0219] The effects of surfactants Span 20, Tween 60, Tween 65, and polysorbate 80 on drying time were evaluated. Additional surfactants were added at 1% to the formulations in Table 12, which contained 5% propyl acetate as a cosolvent. The results for each formulation and drying time (seconds) are summarized in Table 13.

[0220] [Table 13]

[0221] (Example 4) Adhesive properties Formulation No. 11 from Example 2 was tested for its adhesive properties by performing tape tests on various substrates (LDPE, HDPE, PP, and PET) using two types of tape (3M Scotch Grade 810 and Elocometer ISO 2409).

[0222] The PP base material was obtained from Engineering and Design Plastics, Inc. in 1.5mm sheets, in natural finish.

[0223] The LDPE substrate was obtained from Engineering and Design Plastics, Inc. in 1.5mm sheets, in natural finish.

[0224] The HDPE substrate was obtained from Engineering and Design Plastics, Inc. in 1.5mm sheets, in natural finish.

[0225] The PET substrate was obtained from Engineering and Design Plastics, Inc. as a 1.5mm sheet of Veralite 100, A-PET.

[0226] I obtained 3M Scotch Grade 810 adhesive tape from Lyreco.

[0227] The Elcometer ISO 2409 adhesive tape was obtained from Elcometer's adhesive tape supplier.

[0228] Figure 3 shows test messages printed at 200x300dpi on PP, LDPE, HDPE, and PET, from left to right.

[0229] The tests will be conducted 24 hours after printing the formulation onto the substrate, using a Domino G-series printer, an HP 45Si cartridge, and a sample slide of the substrate under test.

[0230] A 5cm segment of the test tape, either 3M Scotch Grade 810 or Elcometer ISO 2409, was attached to separate printed squares and quickly peeled off.

[0231] This test is repeated in three squares for each tape type and substrate. The adhesive properties of the tape are visually evaluated using the evaluation method in Table 14.

[0232] [Table 14]

[0233] Table 15 shows the excellent test results of formulation number 11 for a specific substrate.

[0234] Table 15

Claims

1. C １～６ Alcohol solvent, C ３～１２ The solution comprises an ester solvent, a siloxane surfactant, and a capping resin selected from rosin resins and terpene phenol resins. The C1-6 alcohol solvent is a mixture of two or more C1-6 alcohols. An ink composition for use in drop-on-demand inkjet printing.

2. The ink composition according to claim 1, wherein the siloxane surfactant has a random structure, a block structure, a comb-shaped structure, or a star-shaped structure.

3. The ink composition according to claim 1 or 2, wherein the siloxane surfactant is a polyether-modified siloxane surfactant.

4. The ink composition according to any one of claims 1 to 3, wherein a siloxane surfactant is present in an amount of 0.1 to 1.5% by mass.

5. The ink composition according to any one of claims 1 to 4, wherein the capping resin is hydrophobic.

6. C of capping resin １～６ The ink composition according to any one of claims 1 to 5, wherein the solubility in an alcohol solvent is less than 1 gram / 100 grams at 25°C.

7. The rosin resin is selected from glycerol ester hydrogenated rosin resin and hydrogenated rosin esters. The ink composition according to any one of claims 1 to 6, wherein the terpene phenol resin is selected from hydrogenated terpene phenol resins and terpene phenol resins produced by copolymerization of terpenes with phenol or bisphenol.

8. C １～６ The ink composition according to any one of claims 1 to 7, wherein the alcohol solvent is present in an amount of more than 70% by mass relative to the total mass of the ink composition.

9. C １～６ The ink composition according to any one of claims 1 to 8, wherein alcohol is present in the composition at an amount of 70 to 90% by mass relative to the total mass of the ink composition.

10. C １～６ The ink composition according to any one of claims 1 to 9, wherein the alcohol solvent has a boiling point of 60 to 120°C at a pressure of 1.0 bar.

11. C １～６ The ink composition according to any one of claims 1 to 10, wherein the alcohol solvent is a mixture of two or more C1-6 alcohols selected from ethanol, isopropanol, n-propanol, isobutanol, n-butanol, cyclohexanol, cyclopentanol, ethylene glycol, propylene glycol, and 1-methoxy-2-propanol.

12. C １～６ The ink composition according to any one of claims 1 to 11, wherein the alcohol solvent is a mixture of ethanol and 1-methoxy-2-propanol.

13. C ３～１２ The ink composition according to any one of claims 1 to 12, wherein the ester solvent is present at 20% by mass or less based on the total mass of the ink composition.

14. C ３～１２ The ink composition according to any one of claims 1 to 13, wherein an ester solvent is present in the composition at an amount of 0.5 to 8% by mass relative to the total mass of the ink composition.

15. C ３～１２ The ink composition according to any one of claims 1 to 14, wherein the ester solvent has a boiling point of 100 to 200°C at a pressure of 1.0 bar.

16. The ink composition according to any one of claims 1 to 15, further comprising a polysorbate surfactant.

17. The ink composition according to claim 16, wherein the polysorbate surfactant is present in an amount of 0.5 to 1.5% by mass relative to the total mass of the ink composition.

18. The ink composition according to claim 16 or 17, wherein the mass-average molecular weight (Mw) of the polysorbate surfactant is 1,200 to 2,000.

19. The ink composition according to any one of claims 1 to 18, further comprising a binder.

20. The ink composition according to claim 19, wherein the binder comprises one or more polymers having one or more coordination groups selected from hydroxyl, carboxyl, and amino.

21. The ink composition according to any one of claims 1 to 20, further comprising a metal crosslinking agent.

22. A printing method comprising the steps of providing an ink composition according to any one of claims 1 to 21, depositing the ink composition onto a substrate, and drying the deposited composition.

23. An ink cartridge comprising the composition according to any one of claims 1 to 21.

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