Stable liquid crosslinking agent composition for heat-curable inks

Abstract

The present disclosure provides an ink vehicle composition comprising a crosslinker compound of formula (I), a hydroxy-functional polymer, and a volatile diluent, and substantially free of butanol. Also provided is a thermosetting heat-curable ink comprising the ink vehicle composition, and a method of applying the thermosetting heat-curable ink to print on a surface of a substrate. The ink vehicle composition and the thermosetting heat-curable ink herein may be stable at room temperature for about 6 to about 24 months. [Formula 1] TIFF2025506799000012.tif40149

Description

[Technical Field]

[0001] This disclosure relates to a stable composition containing a 1,3,5-triazinecarbamate (TACT) crosslinking agent and a method for preparing the same, for use, for example, in high-speed offset printing of thermosetting inks. [Background technology]

[0002] TACT compounds are trifunctional melamine-based crosslinking agents possessing reactive carbamate functional groups. TACT crosslinking agents are solid materials that require dissolution in a solvent. They do not dissolve in polyether glycol solvents, and commercially available TACT crosslinking agents are typically supplied as a 50-52% solution in n-butanol. However, due to the boiling point of butanol, butanol solutions of TACT cannot obtain suitable printing properties for use in high-speed offset printing of thermosetting (heat-curable) ink formulations. Furthermore, during storage, evaporation of butanol can cause the solid crosslinking agent to precipitate from the ink, potentially interfering with the printing process. [Overview of the Initiative] [Problems that the invention aims to solve]

[0003] To date, the use of TACT crosslinkers in thermosetting high-speed offset printing inks (such as those useful for printing images on metal surfaces) remains a technical challenge. Due to its solubility parameters, TACT does not dissolve on its own in common ink diluents. Therefore, there remains a need for stable TACT crosslinker compositions for use in thermosetting high-speed offset printing inks, and preferably, they must have printing performance equivalent to or better than existing formulations that do not use TACT as a curing agent. [Means for solving the problem]

[0004] In one embodiment, R 1 , R 2 , and R 3 Each is an independent C 1-10An alkyl crosslinking agent compound of formula (I), [Chemical formula] a hydroxy-functional polymer, and a non-volatile diluent, and discloses an ink vehicle composition substantially free of butanol. Discloses an ink vehicle composition substantially free of butanol.

[0005] In another aspect, a method of preparing an ink vehicle composition, comprising R 1 R 2 and R 3 are each independently C 1-10 alkyl, dissolving and mixing a crosslinking agent compound of formula (I) in butanol, a hydroxy-functional polymer, and a non-volatile diluent to form a mixture; [Chemical formula] evaporating at least 98% of the butanol from the mixture to provide the composition according to claim 1.

[0006] In another aspect, a thermosetting heat-curable ink comprising (a) the disclosed ink vehicle composition and (b) a colorant is disclosed.

[0007] In another aspect, a method of printing ink on a substrate, comprising applying the disclosed thermosetting heat-curable ink to the surface of the substrate and heating the applied thermosetting heat-curable ink to cure the applied thermosetting heat-curable ink. [Mode for carrying out the invention]

[0008] The present disclosure provides a liquid crosslinking agent composition comprising a TACT crosslinking agent compound. The liquid crosslinking agent composition is particularly suitable for use in the preparation of curable compositions such as high-solids coating compositions, overprint varnishes, printable inks, and other related applications. Also, the TACT crosslinking agent process does not release or generate formaldehyde. In the case of heat-curable inks, the TACT crosslinking agent can be mixed with a hydroxy-functional polymer and a non-volatile diluent to form a heat-curable composition, which can be used as an ink vehicle composition for the preparation of a printable ink. The crosslinking agent composition and the ink described herein may remain stable for a long time at room temperature without crosslinking of components, solid precipitation, or layering. Accordingly, the present disclosure provides a formaldehyde-free, heat-curable, printable ink that may be useful for printing an image on a hard surface such as the metal surface of a container.

[0009] (1. Definitions) As used herein, the terms "comprise(s)", "include(s)", "having", "has", "can", "contain(s)", and variations thereof are intended to be open-ended conjunctive phrases, terms, or words that do not preclude the possibility of additional acts or structures. The singular forms "a", "an", and "the" include plural references unless the context clearly dictates otherwise. The present disclosure also contemplates other embodiments "comprising", "consisting of", and "consisting essentially of" the embodiments or elements presented herein, whether explicitly defined or not.

[0010] The modifier "about" used in connection with a quantity encompasses the recited value and has the meaning indicated by the context (e.g., including at least the degree of error associated with the measurement of a particular quantity). It is also desirable to consider the modifier "about" as disclosing a range defined by the absolute values of two endpoints. For example, the expression "about 2 to about 4" also disclosures the range of "about 2 to about 4". The term "about" may refer to plus or minus 10% of the indicated numerical value. For example, "about 10%" may indicate a range from 9% to 11%, and "about 1" may mean from 0.9 to 1.1. Other meanings of "about" may be apparent from the context, such as rounding, so for example "about 1" may also mean from 0.5 to 1.4.

[0011] Regarding the description of numerical ranges in this specification, each numerical value intervening therebetween with the same degree of precision is explicitly contemplated. For example, for the range of 6 to 9, in addition to 6 and 9, the numbers 7 and 8 are assumed, and for the range of 6.0 to 7.0, the numbers 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0 are explicitly assumed.

[0012] As used herein, the term "alkyl" means a straight-chain or branched-chain saturated hydrocarbon chain containing 1 to 20 carbon atoms. The term "lower alkyl" or "C 1-6 alkyl" means a straight-chain or branched-chain hydrocarbon containing 1 to 6 carbon atoms. Representative examples of alkyl include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, 3-methylhexyl, 2,2-dimethylpentyl, 2,3-dimethylpentyl, n-heptyl, n-octyl, n-nonyl, n-decyl, and the like.

[0013] In certain embodiments, the number of carbon atoms in the alkyl is represented by the prefix "C x-y " or "C x -C yThis is represented by "-". Here, x is the minimum number of carbon atoms in the substituent, and y is the maximum number. Therefore, for example, "C 1-4 "Alkyl" or "C1-C4-alkyl" refers to an alkyl substituent containing one to four carbon atoms.

[0014] The term "butanol" refers to n-butanol, which has the formula CH3(CH2)3OH.

[0015] The term "cure" or "curing" refers to the process that results in the curing and / or crosslinking of a hydroxy-functional polymer with other hydroxy-functional polymers, within the same polymer, or in combination thereof. Furthermore, non-volatile diluents may also interact with the crosslinking agent depending on whether they possess functional groups that can react with the crosslinking agent compound. Curing can be initiated by heating.

[0016] The term "substantially absent" means that the component is either not present in the composition or present in the composition in an amount of 2% by weight or less, and includes amounts of 1% by weight or less, 0.5% by weight or less, 0.01% by weight or less, 0.005% by weight or less, or 0.001% by weight or less.

[0017] The terms "hydroxy" and "hydroxyl" are used interchangeably in this specification and refer to the -OH group.

[0018] The term "molecular weight" refers to the number-average molecular weight unless otherwise specified. Molecular weight can be measured by standard methods known in the art, such as gel permeation chromatography, size exclusion chromatography, and rheological analysis.

[0019] The terms “non-volatile” and “volatile” in relation to the components of ink vehicle compositions and / or inks refer to the proportion of components (e.g., non-volatile diluents) released from the ink vehicle composition and / or ink under given bake conditions, as described in ASTM D2369-20. For example, “volatile” refers to components that substantially vaporize from the ink vehicle composition and / or ink when heated at 110±5°C for 60 minutes (e.g., 90% or more, 95% or more, 99% or more, or about 100%). “Non-volatile” refers to components that substantially do not vaporize from the ink vehicle composition and / or ink when heated at 110±5°C for 60 minutes (e.g., less than 10%, less than 5%, less than 1%, or about 0%).

[0020] The term "oligosaccharide" refers to a substance with a molecular weight ranging from approximately 1,000 g / mol to 3,000 g / mol.

[0021] The term "polymer" refers to a macromolecule with a molecular structure composed of numerous smaller units bonded together. These smaller units generally derive from monomers or oligomers. In this specification, this term is used interchangeably with "resin."

[0022] The term "room temperature" refers to a temperature between approximately 20°C and 25°C.

[0023] (2. Ink vehicle composition) In one embodiment, this disclosure is R 1 , R 2 , and R 3 Each is an independent C 1-10 A crosslinking agent compound of formula (I) which is alkyl, [ka] Hydroxy-functional polymers and It contains a non-volatile diluent, We disclose an ink vehicle composition that is substantially butanol-free.

[0024] In some embodiments, R 1 , R 2 , and R3 Each is an independent C 1-4 It is alkyl. In some embodiments, R 1 , R 2 , and R 3 These are, respectively, independent n-butyl (-CH2CH2CH2CH3) or methyl (-CH3). TACT-based crosslinking compounds are commercially available and are usually supplied in n-butanol as the solvent. n-butanol and other volatile cosolvents can be replaced with non-volatile diluents by suitable solvent exchange.

[0025] The crosslinking compound may also be referred to herein as 1,3,5-triazinecarbamate (TACT) crosslinking agent. TACT crosslinking agents can be used to crosslink polymers containing hydroxyl, epoxy, thiol, amino, and / or carboxyl functional groups. For example, a TACT crosslinking agent can react with the hydroxyl groups of a hydroxyl-functional polymer at temperatures above 125°C to form urethane bonds. TACT-based crosslinking processes do not produce or release formaldehyde. Therefore, the disclosed ink vehicle compositions may be formaldehyde-free. In some embodiments, the ink vehicle compositions are formaldehyde-free or substantially formaldehyde-free.

[0026] The crosslinking agent compound may be used as the sole crosslinking agent in the ink vehicle composition, or it may be used in combination with other crosslinking agents such as amino resins or isocyanates. Other crosslinking agents may be used to achieve a balance of properties. In some embodiments, the ink vehicle composition does not contain any crosslinking agents other than the crosslinking agent compound.

[0027] The ink vehicle composition may contain about 10% to about 90% by weight of a crosslinking agent compound, for example, about 20% to about 80% by weight or about 25% to about 70% by weight.

[0028] The hydroxy-functional polymers described herein are polymers containing multiple hydroxyl groups. For example, a hydroxy-functional polymer may contain at least two, preferably two or more, hydroxyl groups. The hydroxyl groups may be pendant from the polymer backbone, at the ends of the polymer, or both. The hydroxy-functional polymer may be modified with one or more fatty acids. Suitable hydroxy-functional polymers include, for example, polyacrylics, polyesters, polyurethanes, and alkyd materials. Suitable hydroxy-functional polyacrylic polymers can be obtained, for example, by copolymerization of an acrylic acid ester or methacrylic acid ester with a hydroxy-functional acrylic acid ester or methacrylic acid ester such as hydroxyethyl acrylate or methacrylate. Suitable hydroxy-functional polyesters can be obtained, for example, by reaction of a polycarboxylic acid with an excess amount of polyhydric alcohol. In some embodiments, the hydroxy-functional polymer is a hydroxy-functional polyester, a hydroxy-functional polyacrylic, a hydroxy-functional polyurethane, or a combination thereof. In some embodiments, the hydroxy-functional polymer is a hydroxy-functional polyester or a hydroxy-functional polyacrylic.

[0029] Hydroxyl-functional polymers may have molecular weights and hydroxyl numbers suitable for use in ink formulations such as thermosetting and heat-curing inks. For example, hydroxyyl-functional polymers may have a weight-average molecular weight (Mw) of about 1000 g / mol to about 6000 g / mol and a number-average molecular weight (Mn) of about 500 g / mol to about 3000 g / mol. Furthermore, hydroxyyl-functional polymers may have a hydroxyl number of about 30 to about 300 mg KOH / g polymer. Hydroxyl-functional polymers may also have an acid value of about 10 to about 100 mg KOH / g polymer.

[0030] Examples of hydroxy-functional polymers include JONCRYL(R) 540 acrylic polymer (SC Johnson & Sons, Racine, WI), JONCRYL(R) 500 acrylic polymer (SC Johnson & Sons, Racine, WI), ACRYLOID(R) AT-400 acrylic polymer (Rohm & Haas, Philadelphia, PA), CYPLEX(R) 1531 polyester polymer (Cytec Industries, West Paterson, NJ), CARGILL 3000 and 5776 polyester polymers (Cargill, Minneapolis, MN), TONE(R) polyester polymer (Union Carbide, Danbury, CT), K-FLEX(R) XM-2302 and XM-2306 polymers (King Industries, Norwalk, CT), and CHEMPOL(R) 11-1369 polymer (Cook Composites and Polymers, Port). Examples include RHOPLEX(R) AC-1024 acrylic emulsion resin (Rohm & Haas, Philadelphia, PA), XC(R) 4005 water-reducing acrylic resin (Cytec Industries, West Paterson, NJ), CRYLCOAT(R) 3494 solid hydroxy-terminated polyester resin (UCB CHEMICALS USA, Smyrna, GA), RUCOTE(R) 101 polyester resin (Ruco Polymer, Hicksville, NY), JONCRYL(R) SCX-800-A and SCX800-B hydroxy-functional solid acrylic resins (SC Johnson & Sons, Racine, WI), and ALFTALAT(R) AN 745 hydroxy-functional polyester resin, a product of Hoechst Corporation.

[0031] In some embodiments, the hydroxy-functional polymer is a hydroxy-functional polyester (also called a polyester polyol). Suitable polyester polyols include, for example, tridecyl ester polymers prepared from 1,3-benzenedicarboxylic acid, 1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylic acid, and 2,2-dimethyl-1,3-propanediol.

[0032] In some embodiments, the hydroxy-functional polymer is a hydroxy-functional polyacrylic. An exemplary hydroxy-functional polyacrylic is JONCRYL(R) 500, which has the following properties: TIFF0007855708000004.tif112149

[0033] The ink vehicle composition may contain about 20% to about 80% by weight of a hydroxy-functional polymer, for example, about 30% to about 70% by weight or about 40% to about 60% by weight.

[0034] Non-volatile diluents are oligomers and are non-volatile as defined in D2369-20 and herein. Because non-volatile diluents are oligomers, they have a lower molecular weight compared to hydroxy-functional polymers. Non-volatile diluents may be hydrocarbons, glycols, alkylated polyglycols, polyesters, aliphatic alcohols, or combinations thereof. Non-volatile diluents can enable high-speed offset printing with little to no evaporation. For example, non-volatile diluents may have a boiling point of at least 145°C, such as at least 150°C, at least 160°C, or at least 170°C. In some embodiments, non-volatile diluents have a boiling point of about 145°C to about 200°C, such as about 145°C to about 190°C or about 150°C to about 185°C. Therefore, non-volatile diluents do not readily evaporate into a gas at room temperature or the temperature used for thermal ink curing.

[0035] As described above, the crosslinking compound may be provided in a solvent. In these embodiments, the non-volatile diluent may be exchanged for the solvent and may have a boiling point at least 30°C higher than the boiling point of the exchanged solvent, for example, at least 40°C higher than the boiling point of the exchanged solvent, at least 50°C higher than the boiling point of the exchanged solvent, or at least 60°C higher than the boiling point of the exchanged solvent.

[0036] During the curing process, the non-volatile diluent may or may not participate in the crosslinking reaction. Whether or not the non-volatile diluent participates in the crosslinking reaction depends on whether or not the non-volatile diluent has functional groups that can react with the crosslinking compound. In some embodiments, the non-volatile diluent reacts with the crosslinking compound during curing. For example, the non-volatile diluent may have hydroxyl functional groups, epoxy functional groups, thiol functional groups, amino functional groups, and / or carboxyl functional groups. In some embodiments, the non-volatile diluent has at least one hydroxyl functional group. In other embodiments, the non-volatile diluent does not react with the crosslinking compound during curing.

[0037] Suitable non-volatile diluents include commercially available polyalkanolamines (Eastman), glycols and polyglycols (BASF, Dow), and aliphatic alcohols (such as tridecanol). In some embodiments, the non-volatile diluent is polyalkylene glycol. Polyalkylene glycol can be synthesized by a ring-opening reaction between an alkylene oxide, such as ethylene oxide or propylene oxide, and an alcohol, such as glycol. Polyalkylene glycol may contain one monomer or two or more monomers. Furthermore, polyalkylene glycol may be alkylated. In some embodiments, the polyalkylene glycol is polyethylene oxide, polypropylene oxide, a butoxy-(polyethylene oxide-polypropylene oxide) mixture, or a combination thereof. In some embodiments, the non-volatile diluent is polyalkylene glycol, a butoxy-(polyethylene oxide-polypropylene oxide) mixture, or a combination thereof.

[0038] The ink vehicle composition may contain about 5% to about 30% by weight of a non-volatile diluent, for example, about 5% to about 20% by weight or about 10% to about 20% by weight.

[0039] In some embodiments, the ink vehicle composition may contain about 10% to about 30% by weight of a crosslinking agent compound, about 40% to about 80% by weight of a hydroxy-functional polymer, and about 5% to about 20% by weight of a non-volatile diluent. Examples of compositions are shown below. TIFF0007855708000005.tif32154

[0040] In some embodiments, the composition comprises a crosslinking agent compound of formula (I), R 1 , R 2 , and R 3 These are, respectively, methyl or n-butyl, a hydroxy-functional polyester as a hydroxy-functional polymer, and a polyalkylene glycol as a non-volatile diluent.

[0041] As described above, butanol is incompatible with thermosetting ink formulations. Therefore, the disclosed ink vehicle composition can be used in thermosetting ink compositions and may contain little to no butanol. For example, the ink vehicle composition may contain 2% by weight or less of butanol, for example, 1% by weight or less, 0.5% by weight or less, 0.1% by weight or less, 0.05% by weight or less, 0.01% by weight or less, 0.005% by weight or less, or 0.001% by weight or less. In some embodiments, the ink vehicle composition contains 0.1% by weight or less of butanol. In some embodiments, the ink vehicle composition is substantially butanol-free. In some embodiments, the ink vehicle composition is butanol-free.

[0042] In addition, the ink vehicle composition may be substantially free of other volatile solvents, including water and organic solvents such as hydrocarbons, alcohols, ketones, ethers, esters, and amide solvents known in the art. In some embodiments, the composition contains no volatile solvents at all.

[0043] The ink vehicle composition may have properties suitable for ink formulations. For example, the ink vehicle composition may be a liquid. Furthermore, the ink vehicle composition may have a viscosity of about 200 to about 500 poise, for example, about 250 to about 350 poise. The ink vehicle composition may also have a density of about 8 lbs / gallon to about 12 lbs / gallon, for example, about 9, about 9.5, about 10, or about 11 lbs / gallon. In some embodiments, the composition may have a density of about 9.3 lbs / gallon.

[0044] The ink vehicle composition may be in the form of a transparent liquid. The ink vehicle composition may have a refractive index of 1.2 or higher, for example, 1.3 or higher, 1.4 or higher, 1.5 or higher, or 1.6 or higher. In some embodiments, the composition has a refractive index of 1.496 or higher.

[0045] A combination of crosslinking compounds, hydroxy-functional polymers, and non-volatile diluents can impart advantageous stability properties to the ink vehicle composition and the ink itself. For example, an ink vehicle composition may be stable for at least 6 months at room temperature, including at least 12 months, at least 18 months, or at least 24 months. In some embodiments, the ink vehicle composition is stable for about 6 to about 24 months at room temperature. As described herein, an ink vehicle composition is considered stable for a given period if no observable changes occur in its physical appearance or chemical properties during that period. Such changes include, for example, decomposition of components, reactions between different components, precipitation of solid substances, stratification of components, or changes in color. The stability of an ink vehicle composition can be measured or evaluated by observing the composition rheology over time under storage conditions ranging from room temperature to heating and freeze-thaw cycles (see also ASTM D1849, ASTM D2337, etc.). For example, stability can be indicated by the fact that the viscosity or rheology remains unchanged when returned to room temperature, or when maintained at 60°C or 20°C, and no gel particles are formed.

[0046] (a. Method for producing the ink vehicle composition) The ink vehicle composition can be prepared by a method comprising mixing butanol, a hydroxy-functional polymer, and a crosslinking agent compound dissolved in a non-volatile diluent to form a mixture, and then evaporating at least 98% of the butanol from the mixture to provide the disclosed ink vehicle composition.

[0047] Evaporation can be carried out by heating the mixture under reduced pressure, such as 20 mmHg (torr) or less, 10 mmHg or less, or 5 mmHg or less. Evaporation may be carried out at a temperature of about 55°C to about 75°C, for example, about 60°C, about 65°C, or about 70°C. In some embodiments, evaporation is carried out by heating the mixture at about 60°C to about 75°C under a pressure of 20 mmHg or less.

[0048] The amount of butanol remaining in the ink vehicle composition after the evaporation step may be 2% or less of the amount of butanol before evaporation, and may include amounts of 1.5% or less, 1.0% or less, 0.5% or less, 0.1% or less, 0.05% or less, and 0.01% or less.

[0049] (3. Thermosetting ink) In another embodiment, the present disclosure provides a thermosetting heat-curable ink comprising (a) an ink vehicle composition as described herein and (b) a colorant.

[0050] The colorant may be a pigment or a dye. The colorant may be a self-dispersing material and may be used in combination with a separate dispersant. In some embodiments, the colorant is a pigment. Generally, any pigment can be used as long as it is compatible with the other components of the ink and is thermally stable at the required curing temperature. The pigment may be cyan, magenta, yellow, black, white, red, orange, violet, blue, green, brown, or a mixture thereof. Examples of pigments can be grouped by their corresponding color index. Pigment Yellow 1, 3, 5, 12, 13, 14, 15, 17, 34, 35, 37, 41, 42, 43, 55, 74, 81, 83, 87, 93, 94, 95, 97, 108, 109, 110, 117, 119, 138, 139, 153, 154, 155, 157, 166, 167, 168, 174, 175, 180, 185, 193, 213, 214, 215, Pigment Red: 3, 5, 19, 22, 23, 31, 38, 41, 43, 48:1, 48:2, 48:3, 48:4, 48:5, 49:1, 52, 52:1, 52:2, 53:1, 57:1, 57:2, 58:4, 63:1, 64:1, 81, 81:1, 81:2, 81:3, 81:4, 88, 95, 104, 108, 112, 122, 123, 136, 144, 146, 149, 166, 168, 169, 170, 175, 177, 178, 179, 184, 185, 208, 216, 226, 254, 257, 279, Pigment Blue 1, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17:1, 22, 24, 24:1, 27, 28, 29, 36, 60, 61, 62, 63, 75, Pigment black 7, 9, 10, 28, 34, Pigment white 6, 11, 12, 18, 21, 22, Pigment orange 4, 5, 13, 16, 20, 34, 36, 64, Pigment Violet 1, 2, 3, 19, 23, 25, 27, 29, 30, 37, 50, Pigment green 7, 8, 10, 17, 26, 36, and Pigment brown 3, 5, 25, 26.

[0051] The thermosetting heat-curable ink may contain approximately 0.1% to 60% by weight of an ink vehicle composition, such as approximately 30% to 60% by weight or approximately 40% to 60% by weight. Furthermore, the thermosetting heat-curable ink may contain approximately 0.1% to 50% by weight of a colorant, for example, approximately 10% to 60% by weight or approximately 20% to 60% by weight.

[0052] Thermosetting heat-curable inks may further contain lubricants, viscosity modifiers, tack modifiers, flow modifiers, surfactants, diluents, or combinations thereof. Thermosetting heat-curable inks may contain about 0% to about 5% by weight of a tack modifier. Suitable tack modifiers include, for example, talc, clay, silica, or combinations thereof. Thermosetting heat-curable inks may contain about 0% to about 5% by weight of a surfactant. Suitable surfactants include, for example, alkoxylated surfactants. Thermosetting heat-curable inks may contain about 0% to about 20% by weight of a viscosity modifier. Thermosetting heat-curable inks may contain about 0% to about 5% by weight of a flow modifier. Suitable viscosity modifiers and flow modifiers are known in the art.

[0053] Thermosetting heat-curable inks can be prepared by mixing the ink vehicle composition, colorant, and other components described herein. Typically, the ink vehicle composition is measured into a mixing tank. The colorant is then added and dispersed. Diluents and other components may be further added to adjust the viscosity to a desired level.

[0054] Typical thermosetting inks prepared by the methods described herein can be used for printing on any surface that can withstand the temperature required for the curing of the thermosetting ink. Exemplary surfaces include metal surfaces (such as aluminum surfaces). Exemplary thermosetting inks may exhibit the following physical properties: · Tack, 1 foot, 90°F (32.2℃) @ 1200rpm o 8.0 - 21.0 ± 1 (ink) o 14.0~25.0±1 (base material), · grind o < 3 NPIRI o <7.5 microns · Raleigh viscosity, 25℃ o 50±20 poise.

[0055] The thermosetting inks described herein may be stable for at least 6 months at room temperature, including at least 12 months, at least 18 months, or at least 24 months. In some embodiments, the thermosetting heat-curable inks are stable for about 6 to about 24 months at room temperature. The thermosetting heat-curable inks can be maintained so as not to undergo discoloration induced by heat or air oxidation. Crosslinking reactions may not occur in the inks of the present invention until sufficient activation energy is provided during the curing cycle (e.g., in a firing enamel oven). The inks of the present invention can avoid pigment precipitation during storage and use.

[0056] (4. Printing) In another embodiment, the Disclosure provides a method for printing ink onto a substrate, comprising the steps of applying a thermosetting heat-curable ink described herein to the surface of the substrate, and heating the applied ink to cure the applied ink. Curing can typically be achieved without the use of a catalyst. Furthermore, the cured film and / or ink can exhibit useful hardness, chemical resistance, exterior durability, and environmental etching resistance.

[0057] The heating may be carried out at a temperature of at least 150°C, including at least 170°C, at least 190°C, or at least 210°C. In some embodiments, the heating is carried out at a temperature of about 180°C to about 200°C, such as about 185°C, about 190°C, or about 195°C.

[0058] The substrate can be any substrate that can withstand the temperature required to cure the thermosetting heat-curable ink. For example, the substrate may include a metal surface or be made of metal. Suitable substrates include industrial or consumer containers such as beverage or food containers. In some embodiments, the substrate is a metal container such as an aluminum can for holding beverages or food.

[0059] In some embodiments, the thermosetting heat-curable inks of the present invention are used in high-speed offset printing processes to provide printed images or decorations on metal surfaces. Preferred processes include those carried out under applicable standards as described by the National Printing Ink Research Institute (NPIRI). In a typical high-speed offset printing process, ink is transferred from individual color (pigment) inkwells to a lithographic printing plate having an ink-receiving image area. This process is carried out in a rotary system, and a thin metal plate may be wrapped around a cylinder. The ink image is transferred from the plate to a "blanket" (an intermediate cylinder covered with a rubber layer) and then to the substrate surface. For printing aluminum cans, printing can proceed at high speeds of approximately 1000 to 2000 cans per minute (cpm).

[0060] (5. Examples) (Example 1 - Preparation of Ink Vehicle Composition) R 1 , R 2 , and R 3 A TACT-based crosslinking agent solid of formula (I), in which each of the elements is independently methyl or n-butyl, was mixed in about 50% by weight of a butanol mixture (15.5 parts by weight), a polyester polyol (49.5 parts by weight), and a polyalkylene glycol non-volatile diluent (35 parts by weight). At least 98% of the butanol was removed from the mixture by rotary evaporation at 65°C under reduced pressure of about 20 torr.

[0061] The resulting composition was stored at room temperature for two years, but no precipitation was observed.

[0062] (Example 2 - Preparation of thermosetting heat-curable ink) A thermosetting heat-curable ink was prepared according to the formula. TIFF0007855708000006.tif41148

[0063] (Example 3 - Printing on aluminum cans) The ink produced in Example 2 was printed onto an aluminum can using a high-speed offset printing method, and the ink on the printed can was cured in a baking oven at a temperature of 193°C (380°F).

[0064] For completeness, various aspects of the present invention are shown in the following numbered sections.

[0065] (Item 1)R 1 , R 2 , and R 3 Each is an independent C 1-10 A crosslinking agent compound of formula (I) which is alkyl, [ka] Hydroxy-functional polymers and It contains a non-volatile diluent, A substantially butanol-free ink vehicle composition.

[0066] (Item 2)R 1 , R 2 , and R 3 These are independent C 1-4 A composition described in item 1, which is alkyl.

[0067] (Item 3) The composition according to Item 1 or Item 2, wherein the crosslinking agent compound is present in an amount of about 10% to about 90% by weight of the composition.

[0068] (Item 4) The hydroxy-functional polymer is selected from the group consisting of hydroxy-functional polyester, hydroxy-functional polyacrylic, hydroxy-functional polyurethane, and combinations thereof, as described in any one of Items 1 to 3.

[0069] (Item 5) The composition according to any one of Items 1 to 4, wherein the hydroxy-functional polymer is present in an amount of about 20% to about 80% by weight of the composition.

[0070] (Item 6) The non-volatile diluent is a composition according to any one of Items 1 to 5, selected from the group consisting of hydrocarbons, glycols, polyalkylene glycols, polyesters, and combinations thereof.

[0071] (Item 7) The composition according to any one of Items 1 to 6, wherein the non-volatile diluent is in an amount of about 5% to about 30% by weight of the composition.

[0072] (Item 8) A composition according to any one of items 1 to 7, having a viscosity of about 200 to about 500 poise.

[0073] (Item 9) The composition according to any one of items 1 to 8, wherein the composition is stable at room temperature for about 6 to about 24 months.

[0074] (Item 10)R 1 , R 2 , and R 3The composition according to any one of items 1 to 9, wherein each is independently methyl or n-butyl, the hydroxy-functional polymer is a hydroxy-functional polyester, and the non-volatile diluent is a polyalkylene polyglycol.

[0075] (Item 11) A method for preparing an ink vehicle composition, R 1 , R 2 , and R 3 Each is an independent C 1-10 A step of dissolving and mixing an alkyl crosslinking agent compound of formula (I) with butanol, a hydroxy-functional polymer, and a non-volatile diluent to form a mixture, [ka] A method comprising the step of evaporating at least 98% of the butanol from the mixture to provide the composition according to claim 1.

[0076] (Item 12) The method according to Item 11, wherein the evaporation comprises heating the mixture at a temperature of about 65°C under a pressure of 20 mmHg(torr) or less.

[0077] (Item 13) A thermosetting heat-curable ink comprising (a) an ink vehicle composition described in any of Items 1 to 10, and (b) a colorant.

[0078] (Item 14) The thermosetting heat-curable ink described in Item 13, wherein the ink is stable at room temperature for at least 6 months.

[0079] (Item 15) The thermosetting heat-curable ink according to Item 13 or Item 14, wherein the ink vehicle composition is in an amount of about 30% to about 60% by weight of the ink.

[0080] (Item 16) A thermosetting heat-curable ink according to any one of Items 13 to 15, wherein the colorant is in an amount of about 10% to about 60% by weight of the ink.

[0081] (Item 17) A thermosetting ink as described in any one of items 13 to 16, further comprising a lubricant, viscosity modifier, tack modifier, flow modifier, surfactant, diluent, or a combination thereof.

[0082] (Item 18) A method for printing ink onto a substrate, comprising the steps of: applying the thermosetting heat-curable ink described in any one of Items 13 to 17 to the surface of the substrate; and curing the applied thermosetting heat-curable ink by heating the applied thermosetting heat-curable ink.

[0083] (Item 19) The method according to Item 18, wherein the surface is a metal surface.

[0084] (Item 20) The method according to Item 18 or Item 19, wherein the substrate is a container.

[0085] Various features, advantages, and embodiments are described in the following claims.

Claims

1. R １ , R ２ , and R ３ Each is an independent C １－1０ A crosslinking agent compound of formula (I) which is alkyl, 【Chemistry 1】 (I) Hydroxy-functional polymers and It comprises a non-volatile diluent having a boiling point of 145°C to 200°C, in an amount of 5% to 35% by weight of the ink vehicle composition, An ink vehicle composition that is substantially free of butanol and water.

2. R １ , R ２ , and R ３ Each is an independent C １－４ The ink vehicle composition according to claim 1, wherein it is alkyl.

3. The ink vehicle composition according to claim 1, wherein the crosslinking agent compound is in an amount of 10% to 90% by weight of the ink vehicle composition.

4. The ink vehicle composition according to claim 1, wherein the hydroxy-functional polymer is selected from the group consisting of hydroxy-functional polyester, hydroxy-functional polyacrylic, hydroxy-functional polyurethane, and combinations thereof.

5. The ink vehicle composition according to claim 1, wherein the hydroxy-functional polymer is present in an amount of 20% to 80% by weight of the ink vehicle composition.

6. The ink vehicle composition according to claim 1, wherein the non-volatile diluent is selected from the group consisting of hydrocarbons, glycols, polyalkylene glycols, polyesters, and combinations thereof.

7. The ink vehicle composition according to claim 1, having a viscosity of 200 to 500 poise.

8. The ink vehicle composition according to claim 1, wherein the ink vehicle composition is stable at room temperature for 6 to 24 months.

9. R １ 、 R ２ 、 and R ３ are each independently methyl or n-butyl, the hydroxy-functional polymer is a hydroxy-functional polyester, and the non-volatile diluent is a polyalkylene glycol, the ink vehicle composition according to claim 1.

10. A method for preparing an ink vehicle composition, R １ , R ２ , and R ３ Each is an independent C １－1０ A step of dissolving and mixing an alkyl crosslinking agent compound of formula (I) with butanol, a hydroxy-functional polymer, and a non-volatile diluent having a boiling point of 145°C to 200°C to form a mixture, 【Chemistry 1】 (I) A method comprising the step of evaporating at least 98% of the butanol from the mixture to provide the ink vehicle composition according to claim 1.

11. The method according to claim 10, wherein the evaporation comprises heating the mixture at a temperature of 65°C under a pressure of 20 mmHg (torr) or less.

12. (a) The ink vehicle composition according to claim 1, (b) A thermosetting heat-curing ink comprising a colorant.

13. The thermosetting heat-curable ink according to claim 12, wherein the thermosetting heat-curable ink is stable at room temperature for at least six months.

14. The thermosetting heat-curable ink according to claim 12, wherein the ink vehicle composition is in an amount of 30% to 60% by weight of the thermosetting heat-curable ink.

15. The thermosetting heat-curable ink according to claim 12, wherein the coloring agent is in an amount of 10% to 60% by weight of the thermosetting heat-curable ink.

16. The thermosetting heat-curable ink according to claim 12, further comprising a lubricant, viscosity modifier, tack modifier, flow modifier, surfactant, diluent, or a combination thereof.

17. A method for printing ink onto a substrate, A step of applying the thermosetting heat-curable ink described in claim 12 to the surface of the substrate, A method comprising the step of curing the applied thermosetting heat-curable ink by heating the applied thermosetting heat-curable ink.

18. The method according to claim 17, wherein the surface is a metal surface.

19. The method according to claim 17, wherein the base material is a container.

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