Latexes with phosphoric acid functional resin particles

Abstract

To provide latexes which may be used to provide resin particles for a variety of compositions such as aqueous inkjet ink compositions.SOLUTION: Latex compositions are provided. In embodiments, a latex comprises water and resin particles. The resin particles comprise a polymerization product of reactants including one or more types of hydrophobic monomers and one or more types of acidic monomers comprising one or more types of phosphoric acid monomers, such that the total amount of polymerized acidic monomers in the resin particles is at least about 8 wt.% and the total amount of polymerized phosphoric acid monomers in the resin particles is at least about 2 wt.%.SELECTED DRAWING: None

Description

[Background technology]

[0001] Water-based inkjet ink compositions often contain water, a water-dispersible colorant, a hydrophilic solvent, and a binder resin. The binder resin enhances the ink's durability and coating properties. It is also used to adjust and control the ink's viscosity to achieve suitable spray performance. Some binder resins have also been developed to adsorb, adhere, or form a coating on the colorant to improve the stability and dispersibility of the colorant within the ink. [Overview of the Initiative]

[0002] This disclosure provides latex that can be used to provide resin particles for various compositions, such as aqueous inkjet ink compositions. The resin particles are polymerized from hydrophobic monomers and acid monomers (including phosphate monomers). When incorporated into aqueous inkjet ink compositions, the ink exhibits remarkably high stability, as evidenced by little or no change in viscosity after long-term storage at high temperatures (e.g., 60°C for 14 days). Aqueous inkjet ink compositions including embodiments of resin particles also exhibit extended open-air stability, facilitating the collection of waste ink from open-air waste trays of aqueous inkjet systems. Embodiments of resin particles also provide aqueous inkjet ink compositions exhibiting high adhesion to various substrates, including excellent water resistance. These advantages are achieved regardless of the type of colorant used, and without the resin particles adsorbing, adhering, or coating on the colorant. Finally, embodiments of resin particles provide a “universal” aqueous inkjet ink composition capable of forming high-quality printed images on a wide range of paper and non-paper substrates, such as metal substrates.

[0003] A latex composition is provided. In an embodiment, the latex comprises water and resin particles. The resin particles comprises a polymerization product of a reaction, which comprises one or more types of hydrophobic monomers and one or more types of acidic monomers comprising one or more types of phosphate monomers, wherein the total amount of polymerized acidic monomers in the resin particles is at least about 8% by weight and the total amount of polymerized phosphate monomers in the resin particles is at least about 2% by weight.

[0004] Other key features and advantages of this disclosure will become apparent to those skilled in the art upon consideration of the following drawings, modes for carrying out the invention, and the appended claims. [Modes for carrying out the invention]

[0005] latex

[0006] In one embodiment, a latex is provided. Such a latex comprises resin particles synthesized from various monomers, forming a polymer material composed of resin particles. Hydrophobic monomers are used to form the resin particles. Various hydrophobic monomers can be used, for example, styrene; alkyl (meth)acrylates such as methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, dodecyl acrylate, n-octyl acrylate, 2-chloroethyl acrylate, methyl methacrylate, ethyl methacrylate, and butyl methacrylate; β-carboxyethyl acrylate Acrylic (β-CEA), phenyl acrylate, methyl alpha chloroacrylate; butadiene; isoprene; methacrylonitrile; acrylonitrile; vinyl ethers such as vinyl methyl ether, vinyl isobutyl ether, and vinyl ethyl ether; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, and vinyl butyrate; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and methyl isopropenyl ketone; vinylidenes such as vinylidene chloride and vinylidene chlorofluoride; N-vinylindole; N-vinylpyrrolidone; methacrylate; acrylamide; methacrylamide; vinylpyridine; vinylpyrrolidone; vinyl-N-methylpyridinium chloride; vinylnaphthalene; p-chlorostyrene; vinyl chloride; vinyl bromide; vinyl fluoride; ethylene; propylene; butylene; and isobutylene. (For example, the use of "(meth)" in "(meth)acrylic acid" refers to both acrylic acid and methacrylic acid.) A single type or a combination of different types of hydrophobic monomers may be used. The phrase "single type" refers to the same chemical compound, and the phrase "different types" refers to different chemical compounds. For example, styrene is a single type of hydrophobic monomer, while styrene and alkyl (meth)acrylates are different types of hydrophobic monomers.Methyl (meth)acrylate is a single type of hydrophobic monomer (specifically, a single type of alkyl (meth)acrylate), while methyl (meth)acrylate and ethyl (meth)acrylate are different types of hydrophobic monomers (specifically, different types of alkyl (meth)acrylates). Therefore, the phrase "one or more types" includes both single types of monomers and different types of monomers.

[0007] In the embodiment, the hydrophobic monomer used to form the resin particles includes styrene, alkyl (meth)acrylate (e.g., methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, or a combination thereof), or both thereof. Thus, the alkyl group of the alkyl (meth)acrylate may have one or more carbon atoms, two or more carbon atoms, four or more carbon atoms, or one to six carbon atoms.

[0008] In the embodiment, certain hydrophobic monomers are not used to form resin particles containing 4-methylstyrene, cyclohexyl acrylate, isobornyl methacrylate, isobornyl acrylate, or a combination thereof.

[0009] Acidic monomers are also used to form resin particles containing phosphate monomers. Phosphate monomers are polymerizable monomers having a polymerizable moiety (e.g., a carbon-carbon double bond) and a P(O)(OR)3 moiety. The polymerizable moiety may be provided by R groups. In the P(O)(OR)3 moiety, each R may be independently selected from hydrogen and organic groups, and at least one R is an organic group. The term phosphoric acid is used in relation to P(O)(OH)3 (having three hydroxyl groups), where the P(O)(OR)3 moiety is phosphoric acid. The phosphate monomers used may have one, two, or three such organic groups, and may be the same or different. Salts of phosphate monomers are also included, i.e., in which the hydrogen of the OH group is replaced by a cation. The P(O)(OR)3 moiety is distinguished from the phosphonic acid moiety having the formula P(O)(OR)2R.

[0010] In embodiments, the organic group is an alkyl (meth)acrylate. In embodiments, the alkyl group of the alkyl (meth)acrylate has at least two carbon atoms, at least three carbon atoms, at least four carbon atoms, at least five carbon atoms, or one to six carbon atoms. In embodiments, at least one R is an ethyl (meth)acrylate. In embodiments, the phosphate monomer has one, two, or three ethyl (meth)acrylate groups. Exemplary phosphate monomers include 2-hydroxyethyl methacrylate phosphate and bis[2-(methacryloyloxy)ethyl]phosphate.

[0011] In this embodiment, the organic group has formula I, [ka] In the formula, R 1~3 R1 is independently selected from hydrogen and methyl, n is 0 to 20, including any number from 0 to 20, and "*" indicates bonding of the P(O)(OR)3 moiety to oxygen. In embodiments, n is 0, R1 is hydrogen or methyl, and R3 is hydrogen. One, two, or three such organic groups may be present.

[0012] In embodiments, the phosphate monomer is based on poly(ethylene glycol), where R1 is hydrogen or methyl, R2 is hydrogen, R3 is hydrogen, and n is 0 to 20. In embodiments, n is 1 to 20. This includes 2 to 16 and 4 to 12. However, one, two, or three such organic groups may be present. In embodiments, one such organic group is present to provide a phosphate ester of poly(ethylene glycol) mono(meth)acrylate (i.e., the other R group is hydrogen).

[0013] In embodiments, the phosphoric acid monomer is based on poly(propylene glycol), where R1 is hydrogen or methyl, R2 is methyl, R3 is methyl, and n is 0 to 20. In embodiments, n is 1 to 20. This includes 2 to 16 and 4 to 12. However, one, two, or three such organic groups may be present. In embodiments, one such organic group is present to provide a phosphoric acid ester of poly(propylene glycol) mono(meth)acrylate (i.e., the other R group is hydrogen).

[0014] Other organic groups may be used, but in this embodiment, the organic group is not vinyl (i.e., CH2CH2).

[0015] A single type or a combination of different types of phosphate monomers may be used. (The meanings of "single type," "different types," and "one or more types" are similar to those described above for hydrophobic monomers.)

[0016] In addition to phosphate monomers, other acidic monomers can be used to form resin particles. These other acidic monomers refer to different types, i.e., different chemical compounds, compared to the selected phosphate monomers, and do not have the P(O)(OR)3 portion mentioned above. Therefore, these other acidic monomers may be referred to as "additional acidic monomers." Additional acidic monomers that may be used include (meth)acrylic acid monomers, sulfonic acid monomers, sulfonate monomers, and combinations thereof. Exemplary acidic monomers include acrylic acid, methacrylic acid, ethacrylic acid, dimethylacrylic acid, maleic anhydride, maleic acid, styrene sulfonic acid, vinyl sulfonate, cyanoacrylic acid, vinyl acetic acid, allyl acetic acid, etyridine acetic acid, propyridine acetic acid, crotonic acid, fumaric acid, itaconic acid, sorbic acid, angelic acid, cinnamic acid, styrylacrylic acid, citraconic acid, glutaconic acid, aconitic acid, phenylacrylic acid, acryloxpropionic acid, aconitic acid, phenylacrylic acid, acryloxpropionic acid, vinyl benzoic acid, N Examples include vinyl succinamide acid, mesaconic acid, methacloylalanine, acryloyl hydroxyglycine, sulfoethyl methacrylic acid, sulfopropyl acrylic acid, styrene sulfonic acid, sulfoethyl acrylic acid, 2-methacryloyloxymethane-1-sulfonic acid, 3-methacryloyloxypropane-1-sulfonic acid, 3-(vinyloxy)propane-1-sulfonic acid, ethylene sulfonic acid, vinyl sulfuric acid, 4-vinylphenyl sulfuric acid, vinyl benzoic acid, 2-acrylamido-2-methyl-1-propanesulfonic acid, and combinations thereof. Similar to phosphoric acid monomers, these additional acid monomers also include their salts. Similarly, a single type or combinations of different types of additional acid monomers can be used. (The meanings of "single type," "different types," and "one or more types" are similar to those described above for hydrophobic monomers.)

[0017] In embodiments, additional acidic monomers are used together with phosphate monomers. In embodiments, the additional acidic monomers include (meth)acrylic acid, β-CEA, or both. As further described below, the use of additional acidic monomers (together with phosphate monomers) and in the amounts described below is useful for improving the stability of aqueous inkjet ink compositions formed from the disclosed latex.

[0018] Various other monomers may be used to form resin particles. For example, monomers that are esters of (meth)acrylic acid with an alcohol containing a dioxane moiety or an alcohol containing a dioxolane moiety may be used. In this disclosure, this type of monomer may be referred to as “dioxane / dioxolane monomer”. The phrase “dioxane / dioxolane monomer” encompasses monomers that are esters of (meth)acrylic acid with an alcohol containing a dioxane moiety, esters of (meth)acrylic acid with an alcohol containing a dioxolane moiety, or both. The dioxane moiety may be a 1,3-dioxane moiety, and the dioxolane moiety may be a 1,3-dioxolane moiety. The alcohol containing the dioxane / dioxolane moiety may be a triol, a ketal of a triol, or a carbonate of a triol. Exemplary triols include glycerol and trimethylolpropane. Triols may be unsubstituted or substituted. “Substituted” means that one or more bonds to carbon or hydrogen are replaced by bonds to non-hydrogen and non-carbon atoms. Dioxane / dioxolane monomers may have the following formulas: II (dioxane) or III (dioxolane), where R is selected from hydrogen and methyl, R' is selected from hydrogen and ethyl, and Z is selected from hydrogen, carbonyl oxygen, alkyl group, aryl group, and alkoxy group. Monomers of any or both types may be used in resin particles. [ka] [ka]

[0019] The carbonyl group refers to a C=O group, that is, Z is O covalently bonded to carbon via a double bond, thereby forming a carbonyl group between two oxygens in a 5- or 6-membered ring. The alkyl group can be linear or branched. The alkyl group can have 1 to 20 carbons. This includes having 1 to 18 carbons and 1 to 10 carbons, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbons. The alkyl group can be substituted or unsubstituted. The aryl group can be a monocyclic ring having one aromatic ring, for example, benzene, or a polycyclic ring having one or more fused rings. The aryl group may be unsubstituted or substituted as described above for the alkyl group, but the substituted aryl group also includes an aryl group in which the bond to hydrogen is replaced by a bond to the above unsubstituted or substituted alkyl group. The alkoxy group refers to an -O-alkyl group.

[0020] Exemplary dioxane / dioxolane monomers include glycerol formal (meth)acrylate, trimethylolpropane formal (meth)acrylate, and isopropylidene glycerol (meth)acrylate. Combinations of single types or different types of dioxane / dioxolane monomers can be used. However, in an embodiment, the dioxane / dioxolane monomer is glycerol formal (meth)acrylate. Glycerol formal (meth)acrylate has a relatively high T- g (about 85 to 90 °C). In the present disclosure, the name "glycerol formal (meth)acrylate" (as well as the names of the other dioxane / dioxolane monomers described in this paragraph) refers to either the dioxane isomer, the dioxolane isomer, or both. That is, all possibilities are encompassed by those names.

[0021] Although not required, in some embodiments, polyfunctional monomers, i.e., those containing two or more polymerizable groups (e.g., 2, 3, 4), may be used to form resin particles. (The term "polyfunctional monomer" is used to distinguish it from phosphate monomers that may contain two or more polymerizable groups.) Polyfunctional monomers are useful for promoting crosslinking within the resin particles. Exemplary polyfunctional monomers include poly(ethylene glycol) di(meth)acrylates, such as poly(ethylene glycol) diacrylate with a molecular weight of 250 g / mol. Other poly(ethylene glycol) di(meth)acrylates may be used, including those with molecular weights in the ranges of 214 g / mol to 1000 g / mol, 214 g / mol to 500 g / mol, and 214 g / mol to 300 g / mol. These molecular weight values ​​can be determined using gel permeation chromatography. Other bifunctional monomers include diacrylate compounds bonded to alkyl chains containing ether bonds, such as diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol #400 diacrylate, polyethylene glycol #600 diacrylate, and dipropylene glycol diacrylate, and compounds obtained by substituting the acrylate of these compounds with methacrylate; diacrylate compounds bonded to chains containing aromatic groups and ether bonds, such as polyoxyethylene (2)-2,2-bis(4-hydroxyphenyl)propane diacrylate and polyoxyethylene (4)-2,2-bis(4-hydroxyphenyl)propane diacrylate, and compounds obtained by substituting the acrylate of these compounds with methacrylate.Examples of other bifunctional monomers include diene compounds such as isoprene and butadiene, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene, dialkyl chain-bonded diacrylate compounds such as ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, 1,10-dodecanediol diacrylate, and neopentyl glycol diacrylate, and compounds obtained by substituting the acrylates of these compounds with methacrylates. Examples of polyfunctional monomers include pentaerythritol triacrylate, trimethylolmethane triacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, oligoester acrylate, and compounds obtained by substituting the acrylates of these compounds with methacrylates.

[0022] However, in the embodiment, the monomer used to form the resin particles does not include a polyfunctional monomer, for example, a polyfunctional acrylate. Similarly, in the embodiment, a crosslinking agent, for example, an epoxide-containing compound, is not used to form the resin particles.

[0023] Reactive surfactants can be used to form resin particles. Suitable reactive surfactants contain polymerizable (and therefore reactive) groups that can be incorporated into the resin particles. Exemplary reactive surfactants include anionic ether sulfate reactive surfactants, such as those from the commercially available Hitenol series, including Hitenol AR10-25. Other suitable reactive surfactants include polyoxyethylene alkylphenyl ether ammonium sulfate, Hitenol BC-10, BC-20, BC10-25, BC-2020, BC-30; polyoxyethylene styrene-phenyl ether ammonium sulfate containing Hitenol AR-10, AR-20, AR-2020; nonionic polyoxyethylene alkylphenyl ethers containing Noigen RN-10, RN-20, RN-30, RN-40, RN-5065; and reactive surfactants available from Ethox, including E-sperse RX-201, RX-202, RX-203, RS-1596, RS-1616, RS-1617, RS-1618, RS-1684.

[0024] A chain transfer agent may be used to form resin particles. The chain transfer agent may be a mercaptan or a thiol. Suitable chain transfer agents include n-dodecylmercaptan (NDM), n-dodecanethiol (DDT), tert-dodecylmercaptan, 1-butanethiol, 2-butanethiol, octanthiol, and combinations thereof. Carbon halides such as carbon tetrabromide, carbon tetrachloride, and combinations thereof may be used as chain transfer agents.

[0025] In the embodiment, certain other monomers are excluded when forming resin particles. Monomers that may be excluded are unsaturated ethylene monomers having alkyl groups with 12 to 22 carbon atoms.

[0026] When forming a latex containing resin particles, various combinations of the monomers described above can be used in a monomer emulsion containing a solvent. Water is commonly used as the solvent, but water-soluble or water-miscible organic solvents (e.g., ethanol) may also be used. The types of monomers and their relative amounts can be selected to adjust the properties of the resin particles / latex, including achieving the property values ​​described below. Exemplary amounts are provided below.

[0027] The total amount of hydrophobic monomers used in the monomer emulsion may be in the range of 70% to 97% by weight, 75% to 90% by weight, or 80% to 90% by weight. (Here, weight % refers to (total weight of hydrophobic monomers) / (total weight of monomers in the monomer emulsion excluding reactive surfactants) * 100). If present, alkyl (meth)acrylates (e.g., methyl (meth)acrylate, ethyl (meth)acrylate), butyl (meth)acrylate) may be present in amounts ranging from at least 15% by weight, at least 20% by weight, at least 25% by weight, or 15% to 30% by weight. (Weight % has a similar meaning to that described for hydrophobic monomers.)

[0028] The total amount of acidic monomers used in the monomer emulsion may be at least 8% by weight, at least 10% by weight, or at least 15% by weight. In embodiments, the total amount of acidic monomers is less than 15% by weight or less than 10% by weight. These ranges include amounts of 8% to 25% by weight, 8% to 20% by weight, 10% to 18% by weight, and 10% to 16% by weight. (Weight percent has a similar meaning to that described for hydrophobic monomers.) The total amount of phosphate monomers used in the monomer emulsion may be at least 2% by weight, at least 3% by weight, or at least 4% by weight. In embodiments, the total amount of phosphate monomers is less than 10% by weight or less than 8% by weight. These ranges include amounts of 2% to 10% by weight, 2% to 8% by weight, and 2% to 6% by weight. (Weight percent has a similar meaning to that described for hydrophobic monomers.) As described above, in embodiments, additional acidic monomers are used in addition to phosphate monomers. In such embodiments, the weight ratio of the total amount of phosphate monomer to the total amount of additional acid monomer is 1.0 or less, less than 0.9, less than 0.8, less than 0.7, less than 0.6, less than 0.5, less than 0.4, or a ratio of 0.3 to 1.0, 0.3 to 0.8, or 0.3 to 0.5.

[0029] When dioxane / dioxolane monomers are used in a monomer emulsion, the total amount of dioxane / dioxolane monomers may be in the range of 1% to 40% by weight, 1% to 30% by weight, 1% to 20% by weight, 1% to 10% by weight, and 1% to 5% by weight. (The meaning of weight percent is similar to that described for hydrophobic monomers.)

[0030] When polyfunctional monomers are used in a monomer emulsion, the total amount of polyfunctional monomers may be in the range of 0.001 to 1% by weight, 0.001% to 0.8% by weight, and 0.01% to 0.6% by weight. (The weight percentage has a similar meaning to that described for hydrophobicity.)

[0031] When a reactive surfactant is used in a monomer emulsion, the total amount of the reactive surfactant may be in the range of 0.1% to 6.5% by weight (where weight %) refers to (total weight of reactive surfactant) / (total weight of monomers in the monomer emulsion containing the reactive surfactant monomer) * 100). This range includes 0.3% to 5% by weight.

[0032] The chain transfer agent may be present in the monomer emulsion and may be used in various suitable amounts, for example, 0.25% to 2.5% by weight. (Here, weight % refers to (total weight of chain transfer agent) / (total weight of monomers in the monomer emulsion excluding reactive surfactant) * 100.)

[0033] In the embodiments, the monomer emulsion comprises (or consists of) a solvent, a hydrophobic monomer, and an acidic monomer (including a phosphate monomer). In the embodiments, the hydrophobic monomer includes styrene and alkyl (meth)acrylates, such as butyl acrylate. In the embodiments, the phosphate monomer includes one having the formula P(O)(OR)3, where each R is independently selected from hydrogen and an organic group, and at least one R is an organic group. In the embodiments, the organic group is an alkyl (meth)acrylate. In the embodiments, the organic group has the formula I. In the embodiments, the phosphate monomer includes 2-hydroxyethyl methacrylate phosphate, bis[2-(methacryloyloxy)ethyl]phosphate, or a combination thereof. In the embodiments, the phosphate monomer includes phosphate esters of polyethylene glycol mono(meth)acrylate, phosphate esters of polypropylene glycol mono(meth)acrylate, or a combination thereof. In any of these embodiments, an additional acidic monomer, such as methacrylic acid, may be used. In any of these embodiments, a dioxane / dioxolane monomer (e.g., glycerol formal methacrylate) can be used. In any of these embodiments, a polyfunctional monomer can be used (however, polyfunctional monomers are not used in some embodiments). In any of these embodiments, a reactive surfactant (e.g., anionic ether sulfate) can be used. In any of these embodiments, a chain transfer agent may be used. In any of these embodiments, various amounts of monomers, reactive surfactants, and chain transfer agents may be used as described above. The remainder may consist of a solvent.

[0034] In some embodiments, the monomer emulsion is surfactant-free (i.e., does not contain surfactants). However, in other embodiments, surfactants may be used. Here, “surfactant” refers to non-reactive, non-polymerizable anionic surfactants such as sodium dodecylsulfate (SDS), sodium dodecylbenzenesulfonate, sodium dodecylnaphthalene sulfate; dialkylbenzenealkyl sulfates; palmitic acid; alkyldiphenyl oxide disulfonates; and branched sodium dodecylbenzenesulfonate. “Surfactant” also refers to non-reactive, non-polymerizable cationic surfactants such as alkylbenzyldimethylammonium chloride, dialkylbenzenealkylammonium chloride, lauryltrimethylammonium chloride, alkylbenzylmethylammonium chloride, alkylbenzyldimethylammonium bromide, benzalkonium chloride, cetylpyridinium bromide, trimethylbromide, quaternary polyoxyethylalkylamine halide salts, and dodecylbenzyltriethylammonium chloride. "Surfactants" also refer to non-reactive, non-polymerizable, nonionic surfactants such as polyoxyethylene cetyl ether, polyoxyethylene lauryl ether, polyoxyethylene octyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene sorbitan monolaurate, polyoxyethylene stearyl ether, polyoxyethylene nonylphenyl ether, dialkylphenoxypoly(ethyleneoxy)ethanol, and block copolymers of polyethylene oxide and polypropylene oxide.

[0035] In this embodiment, the monomer emulsion does not contain (i.e., does not include) silica particles. Commercially available silica particles that may be excluded include: various grades of LUDOX colloidal silica such as FM, SM, HS-30, HS-40, LS, TM-40, TM-50, SM-AS, AS-30, AS-40, AM, HSA, TMA, PX-30, Pt-40, PW-50, CL, and CL-P, as well as various grades of Nissan Chemical silica such as SNOWTEX ST-20L, ST-30, ST-40, ST-50, ST-OS, ST-O, ST-O-40, ST-OL, ST-C, ST-C-30, ST-CM, ST-N, STN30G, ST-N40, ST-NS, ST-XS, ST-S, ST-UP, ST-O-UP, MA-ST-UP, ST-PS-S, AMT-330S, HX-305M1, and HX-305M5.

[0036] Various polymerization techniques, such as monomer-deficient emulsion polymerization, conventional emulsion polymerization, suspension polymerization, miniemulsion polymerization, nanoemulsion polymerization, seed emulsion polymerization, and microemulsion polymerization, can be used to form resin particles. These polymerization techniques may use any of the monomer emulsions described above. An exemplary monomer-deficient emulsion polymerization process is described below. However, it should be noted that the polymerization techniques used provide polymerized polymers in the form of particles that are insoluble in aqueous media. This is in contrast to solution polymerization, such as that described in U.S. Patent No. 9,963,592, which provides polymers that can be solubilized in organic media.

[0037] An exemplary method for preparing a latex containing resin particles involves adding one of the monomer emulsions described above to a reactive surfactant solution at a certain supply rate over a period of time. The reactive surfactant solution comprises a solvent and a reactive surfactant. Any of the solvents and reactive surfactants described above may be used. The reactive surfactant in the reactive surfactant solution may be of the same or different type as the reactive surfactant that may be present in the monomer emulsion. The reactive surfactant solution may further contain a buffer. Various buffers such as sodium bicarbonate, sodium carbonate, and ammonium hydroxide may be used. The reactive surfactant may be used in amounts ranging from 0.1% to 10% by weight and 0.5% to 5% by weight. (Here, weight % refers to (total weight of reactive surfactant) / (total weight of reactive surfactant solution) * 100.) The buffer may be used in amounts ranging from 0.25% to 2.5% by weight. (Weight % has the same meaning as described above.)

[0038] The reactive surfactant solution may contain an initiator. Alternatively, a separate initiator solution containing the initiator and one of the solvents described above may be formed and added to the reactive surfactant solution. The separate initiator solution may be added before the monomer emulsion is added. Additional amounts of the separate initiator solution may be added after the monomer emulsion is added. Examples of suitable initiators include water-soluble initiators such as ammonium persulfate (APS), sodium persulfate, and potassium persulfate, as well as organic soluble initiators containing organic peroxides and azo compounds including Vazo peroxides such as VAZO64®, 2-methyl 2-2'-azobispropanenitrile, VAZO88®, and 2-2'-azobisisobutylamide anhydride, and combinations thereof.Other water-soluble initiators that can be used include azoamidine compounds, such as 2,2'-azobis(2-methyl-N-phenylpropionamidine)dihydrochloride, 2,2'-azobis[N-(4-chlorophenyl)-2-methylpropionamidine]dihydrochloride, 2,2'-azobis[N-(4-hydroxyphenyl)-2-methylpropionamidine]dihydrochloride, 2,2'-azobis[N-(4-aminophenyl)-2-methylpropionamidine]tetrahydrochloride, 2,2'-azobis[2-methyl-N(phenylmethyl)propionamidine]dihydrochloride, 2,2'-azobis[2-methyl-N-2-propenylpropionamidine]dihydrochloride, and 2,2'-azobis[N-(2-hydroxy-ethyl)2-methylpropion Amidine dihydrochloride, 2,2'-azobis[2(5-methyl-2-imidazolin-2-yl)propane]dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride, 2,2'-azobis[2-(4,5,6,7-tetrahydro-1H-1,3-diazepine-2-yl)propane]dihydrochloride, 2,2'-azobis[2-( Examples include 3,4,5,6-tetrahydropyrimidine-2-yl)propane]dihydrochloride, 2,2'-azobis[2-(5-hydroxy-3,4,5,6-tetrahydropyrimidine-2-yl)propane]dihydrochloride, 2,2'-azobis{2-[1-(2-hydroxyethyl)-2-imidazolin-2-yl]propane}dihydrochloride, and combinations thereof. The initiator may be used in an amount ranging from 0.05% to 2.5% by weight (where wt% refers to (total weight of initiator) / (total weight of reactive surfactant solution) * 100).

[0039] In some embodiments, the reactive surfactant solution comprises (or consists of) a solvent (e.g., water), a reactive surfactant, and optionally one or more initiators and buffers. In any of these embodiments, the amounts of reactive surfactant, initiator, and buffer may be used as described above. The remainder may consist of a solvent. In at least some embodiments, the reactive surfactant solution does not contain any of the surfactants described above. In at least some embodiments, the reactive surfactant solution does not contain any of the silica particles described above. As a result, the resin particles may be characterized by not containing any of the surfactants and / or silica particles described above. In at least some embodiments, the reactive surfactant solution does not contain any monomers other than the reactive surfactant monomers present in the solution.

[0040] The addition of monomer emulsions to reactive surfactant solutions can be carried out under the influence of an inert gas (e.g., nitrogen) and at high temperatures (e.g., temperatures higher than room temperature, such as in the range of 50°C to 90°C). This can be achieved by purging with an inert gas and heating the reactive surfactant solution before adding the monomer emulsion, and continuing this heating during the addition of the monomer emulsion.

[0041] As described above, the monomer emulsion is added at a supply rate over a set period of time. In the presence of an initiator, the monomers of the monomer emulsion undergo polymerization to form latex resin particles. The supply rate is slow enough so that polymerization is carried out under "monomer-deficient" conditions. This means that the supply rate is less than or equal to the rate of polymerization, for example, the rate between styrene and acrylate monomers. Exemplary supply rates range from 1 mL / min to 10 mL / min based on a total reaction volume of 1 L. Exemplary periods include those ranging from 60 minutes to 600 minutes. After the addition of the monomer emulsion, polymerization can be continued for a further period with or without the addition of further initiators. Exemplary additional periods range from 1 hour to 18 hours. Both the addition of the monomer emulsion and the polymerization after addition can be carried out under an inert gas and at high temperatures. Optionally, the formed latex can be treated by standard techniques such as solidification, dissolution, precipitation, filtration, washing, or drying. Treated or untreated latex may be used to form the aqueous inkjet ink compositions described below.

[0042] The monomer-deficient emulsion polymerization process described above does not involve the use of resin seeds in forming resin particles. However, as mentioned above, seed emulsion polymerization techniques may be used.

[0043] This method may further include forming a monomer emulsion, forming a reactive surfactant solution, and / or forming an initiator solution. Each of these may be formed by combining and mixing desired components in desired amounts.

[0044] The composition of the resin particles depends on the selection of monomers, their relative amounts, and the polymerization reactions between the selected monomers that produce the polymerization products described above. Therefore, a variety of compositions are encompassed, including those based on various polymerization products of reactants containing various monomer combinations. As mentioned above, the reactants include hydrophobic monomers and acidic monomers (including phosphate monomers), but otherwise the selection of other monomers is not particularly limited. For clarity, the composition of the resin particles can be determined by referring to the monomers being polymerized and recognizing that the chemical forms of these monomers generally change as a result of the polymerization reaction. When polymerized in the resin particles, monomers can be referred to as "polymerized monomers."

[0045] In the embodiments, the resin particles include (or consist of) a polymerization product (e.g., copolymer) of a reaction product containing a hydrophobic monomer and an acidic monomer (including a phosphate monomer). In the embodiments, the hydrophobic monomer includes styrene and alkyl (meth)acrylates, such as butyl acrylate. In the embodiments, the phosphate monomer includes one having the formula P(O)(OR)3, where each R is independently selected from hydrogen and an organic group, and at least one R is an organic group. In the embodiments, the organic group is an alkyl (meth)acrylate. In the embodiments, the organic group has the formula I. In the embodiments, the phosphate monomer includes 2-hydroxyethyl methacrylate phosphate, bis[2-(methacryloyloxy)ethyl]phosphate, or a combination thereof. In the embodiments, the phosphate monomer includes phosphate esters of polyethylene glycol mono(meth)acrylate, phosphate esters of polypropylene glycol mono(meth)acrylate, or a combination thereof. In any of these embodiments, additional acidic monomers, such as methacrylic acid, may be used. In any of these embodiments, dioxane / dioxolane monomers (e.g., glycerol formal methacrylate) can be used. In any of these embodiments, polyfunctional monomers can be used (however, polyfunctional monomers are not used in some embodiments). In any of these embodiments, reactive surfactants (e.g., anionic ether sulfates) can be used. In each of these embodiments, the initiator (or a portion thereof) may be incorporated into the end of each polymer chain in the resin particles. In each of these embodiments, the resin particles may be crosslinked. In each of these embodiments, the polymerization monomer may be present in the resin particles in the amounts described above with respect to the amount of monomer in the monomer emulsion. This is because experiments have shown that the conversion of monomers during polymerization is greater than 99.9%. For example, the total amount of polymerization acid monomer in the resin particles may be in the range of 8% to 25% by weight.Similar to the definition of weight percent provided above, when referring to resin particles, the term weight percent refers to (total weight of polymerization acidic monomers) / (total weight of polymerization monomers excluding polymerization reactive surfactants) * 100).

[0046] Using certain exemplary compositions, the composition of resin particles may also be identified as poly[(styrene)-ran-(butyl acrylate)-ran-(2-hydroxyethyl methacrylate phosphate)-ran-(methacrylic acid)-ran-(anionic ether sulfate)]. In this description, different chemical parts resulting from polymerization reactions are identified by referring to the corresponding monomers in parentheses, where "ran" refers to the random incorporation of different monomers into the copolymer. Use of this description includes the presence of an initiator (or a portion thereof) at the starting point of each copolymer, as well as crosslinking (if used).

[0047] In embodiments where certain monomers (or other reactants) are excluded from forming resin particles, such monomers (or other reactants) are not involved in the polymerization reaction for forming the polymer matrix of the resin particles. Therefore, in these embodiments, the resin particle composition may be described as being without (i.e., not containing) one or more 4-methylstyrene, cyclohexyl acrylate, isobornyl methacrylate, isobornyl acrylate, and unsaturated ethylene monomers (having alkyl groups having 12 to 22 carbon atoms).

[0048] In embodiments, the latex may be described as having no resin / polymer other than that provided by the resin of the resin particles of the present invention (i.e., not containing any).

[0049] Since the resin / polymer that makes up the resin particles is already polymerized, latex itself is generally not curable and therefore does not contain an initiator. This does not rule out the presence of small amounts of unreacted or reacted initiators that may be incorporated into the polymer chain. Similarly, latex can be described as monomer-free (i.e., does not contain).

[0050] In this embodiment, the latex may also be described as being free of (i.e., not containing) components such as boric acid, diglycolic acid, chelating agents (e.g., ethylenediaminetetraacetic acid, EDTA), or combinations thereof. In this embodiment, the exclusion of chelating agents does not mean the exclusion of phosphate monomers (which are polymerized into resin particles).

[0051] The latex itself may also be distinguished from the aqueous inkjet ink compositions (and similar compositions) described herein by not containing any colorants (including any of the colorants described below).

[0052] The water content of latex may be at least 40% by weight. This includes at least 50% by weight and at least 60% by weight. These weight percentages refer to the weight of water compared to the total weight of the latex.

[0053] Resin particles can be characterized by their size. The particle size is D 50 This may be reported as particle size, meaning that 50% (by volume) of the sample consists of particles with a diameter less than the stated diameter value. 50Particle size can be measured using a Malvern Zetasizer Nano ZS. For verification of light scattering techniques and methods, NIST polystyrene nanosphere control samples with diameters in the range of 20 nm to 200 nm, available from Microspheres-Nanospheres (Corpuscular Company of Microtrac) or third-party vendors (such as ThermoFisher Scientific), may be used. In embodiments, the resin particles are 50 nm to 120 nm in diameter. 50 It is characterized by its particle size, which includes 60nm-110nm and 70nm-100nm.

[0054] Latex containing these resin particles may be characterized by its viscosity. Viscosity values ​​may refer to specific temperatures and solid content and may be measured using a tuning fork vibratory viscometer (Cole-Parmer). In embodiments, the viscosity at room temperature and 40% solid content ranges from 40 cp to 600 cp. This includes 65 cp to 575 cp, 90 cp to 550 cp, and 115 cp to 525 cp. These viscosities are all initial viscosities measured on the day the latex is formed.

[0055] These resin particles also have their T g Values ​​can be a characteristic. g The values ​​can be measured using Differential Scanning Calorimetry (DSC) TA Instruments Discovery DSC 2500. In the embodiment, T g This range is 40°C to 100°C. This includes 50°C to 90°C and 60°C to 80°C.

[0056] Water-based inkjet ink composition

[0057] Any of the resin particles / latex described above may be used to provide an aqueous inkjet ink composition. “Aqueous inkjet ink composition” means a composition configured for use in an inkjet printing apparatus and capable of being used in an inkjet printing apparatus to form a printed image, as further described below. Resin particles may be present in the aqueous inkjet ink composition in amounts ranging from 1% to 10% by weight and 5% to 10% by weight. (Here, weight % refers to (total weight of resin particles) / (total weight of aqueous inkjet ink composition) * 100.) This range includes 5% to 10% by weight. Various other components may be used to form the aqueous inkjet ink compositions described below.

[0058] Solvent system

[0059] Aqueous inkjet ink compositions contain a water-based solvent system. The solvent system may consist solely of water or may include a mixture of water and a water-soluble and / or water-miscible organic solvent. Water-soluble and water-miscible organic solvents may be referred to herein as cosolvents or humectants. Suitable such organic solvents include aliphatic alcohols, aromatic alcohols, diols, glycol ethers, polyglycol ethers, long-chain alcohols, primary aliphatic alcohols, secondary aliphatic alcohols, 1,2-alcohols, 1,3-alcohols, 1,5-alcohols, ethylene glycol alkyl ethers, propylene glycol alkyl ethers, methoxylated glycerols, and ethoxylated glycerols. Examples of its use include ethylene glycol, propylene glycol, diethylene glycol, hexyl glycol, glycerin, dipropylene glycol, trimethylolpropane, 1,2-hexanediol, 1,5-pentanediol, 2-methyl-1,3-propanediol, 2-ethyl-2-hydroxymethyl-1,3-propanediol, 3-methoxybutanol, 3-methyl-1,5-pentanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and 2,4-heptanediol.Other suitable solvents include amides, ethers, ureas, substituted ureas such as thiourea, ethyleneurea, alkylurea, alkylthiourea, dialkylurea, and dialkylthiourea, carboxylic acids and their salts such as 2-methylpentanoic acid, 2-ethyl-3-propylacrylic acid, 2-ethylhexanoic acid, 3-ethoxypropionic acid, esters, organic sulfides, organic sulfoxides, sulfones (such as sulfolanes), carbitols, butylcarbitols, cellusolve, ethers, and Examples include repropylene glycol monomethyl ether, ether derivatives, hydroxy ethers, amino alcohols, ketones, N-methylpyrrolidinone, 2-pyrrolidinone, cyclohexylpyrrolidone, amides, sulfoxides, lactones, polyelectrolytes, methylsulfonylethanol, imidazole, 1,3-dimethyl-2-imidazolidinone, betaine, sugars, such as 1-deoxy-D-galactitol, mannitol, and inositol, as well as substituted and unsubstituted formamides and substituted and unsubstituted acetamides. Combinations of these organic solvents may also be used.

[0060] Suitable water-soluble and / or water-miscible organic solvents include glycols of hydrocarbons having 4 to 7 carbon atoms. Examples of such glycols include 1,2-pentanediol; 1,2-hexanediol; 1,5-pentanediol; 1,6-hexanediol; 3-methyl-1,3-butanediol; 1,2-butanediol; 2,4-pentanediol; 1,7-heptanediol; 3-methyl-1,5-pentanediol; trimethylolpropane; ethyleneurea; 1,2,6-hexanetriol; 1,2,3-butanetriol; sorbitol; diethylene glycol; 1,2,4-butanetriol; glycerol; diglycerol; and triethylene glycol.

[0061] In the embodiment, the solvent system comprises water, 1,2-alcohols (e.g., 1,2-hexanediol, 1,4-butanediol, or both), glycols (e.g., propylene glycol), and glycerol.

[0062] In solvent systems containing water and organic solvents, the weight ratio of water to organic solvent, as well as the types and relative amounts of different organic solvents, may be selected to achieve certain properties of the aqueous inkjet ink composition, such as desired surface tension and viscosity. In embodiments, the weight ratio of water to organic solvent is 90:10 to 51:49. If more than one organic solvent is used, these weight ratios refer to the total amount of organic solvents. Since water may be present in latex, colorants, etc., these weight ratios refer to the total amount of water.

[0063] Similarly, various total amounts of solvent systems can be used in aqueous inkjet ink compositions. In embodiments, the solvent system is present in amounts of 50% to 95% by weight, 60% to 90% by weight, or 65% to 90% by weight. (Here, weight % refers to (total weight of solvent system) / (total weight of aqueous inkjet ink composition) * 100.) In embodiments, the total amount of water present is at least 50% by weight, at least 60% by weight, at least 70% by weight, at least 80% by weight, or in the range of 50% to 95% by weight. (Here, weight % refers to (total weight of water) / (total weight of aqueous inkjet ink composition) * 100.)

[0064] Coloring agents

[0065] Water-based inkjet ink compositions contain colorants. Therefore, water-based inkjet ink compositions cannot be described as transparent or colorless. Colorants include pigments, dyes, and combinations thereof. Examples of suitable dyes include anionic dyes, cationic dyes, nonionic dyes, and zwitterionic dyes. Specific examples of suitable dyes include food colorants such as black No. 1, black No. 2, red No. 40, blue No. 1, and yellow No. 7, FD&C dyes, acid black dyes (No. 1, 7, 9, 24, 26, 48, 52, 58, 60, 61, 63, 92, 107, 109, 118, 119, 131, 140, 155, 156, 172, 194), acid red dyes (No. 1, 8, 32, 35, 37, 52, 57, 92, 115, 119, 154, 249, 254, 256), Acid Blue Dye (No. 1, 7, 9, 25, 40, 45, 62, 78, 80, 92, 102, 104, 113, 117, 127, 158, 175, 183, 193, 209), Acid Yellow Dye (No. 3, 7, 17, 19, 23, 25, 29, 38, 42, 49, 59, 61, 72, 73, 114, 128, 151), Direct Black Dye (No. 4 , 14, 17, 22, 27, 38, 51, 112, 117, 154, 168), Direct Blue Dye (No. 1, 6, 8, 14, 15, 25, 71, 76, 78, 80, 86, 90, 106, 108, 123, 163, 165, 199, 226), Direct Red Dye (No. 1, 2, 16, 23, 24, 28, 39, 62, 72, 236), Direct Yellow Dye (No. 4, 11, 12, 27, 28, 33, 34, 39, 50, 58, 86, 1 Examples include reactive dyes such as 00, 106, 107, 118, 127, 132, 142, 157), reactive red dyes (No. 4, 31, 56, 180), reactive black dye (No. 31), and reactive yellow dye (No. 37), as well as anthraquinone dyes, monoazo dyes, disazo dyes, phthalocyanine derivatives including various phthalocyanine sulfonates, aza(18)annulene, formazan copper complexes, and triphenodioxazine.

[0066] Examples of suitable pigments include black pigment, cyan pigment, magenta pigment, and yellow pigment. The pigment may be organic or inorganic particles. A suitable inorganic pigment is carbon black. However, other inorganic pigments such as cobalt blue (CoO-Al2O3), chrome yellow (PbCrO4), iron oxide, and titanium dioxide (TiO2) may be suitable. Suitable organic pigments include, for example, azo pigments such as diazo pigments and monoazo pigments, polycyclic pigments (e.g., phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green), perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, pyrantron pigments, and quinophthalone pigments), insoluble dye chelates (e.g., basic dye type chelates and acid dye type chelates), nitro pigments, nitroso pigments, and anthanthrone pigments such as PR168. Representative examples of phthalocyanine blue and green include copper phthalocyanine blue, copper phthalocyanine green, and their derivatives (pigment blue 15, pigment green 7, and pigment green 36). Representative examples of quinacridone include pigment orange 48, pigment orange 49, pigment red 122, pigment red 192, pigment red 202, pigment red 206, pigment red 207, pigment red 209, pigment violet 19, and pigment violet 42. Representative examples of anthraquinone include pigment red 43, pigment red 194, pigment red 177, pigment red 216, and pigment red 226. Representative examples of perylene include Pigment Red 123, Pigment Red 149, Pigment Red 179, Pigment Red 190, Pigment Red 189, and Pigment Red 224. Representative examples of thioindigoids include Pigment Red 86, Pigment Red 87, Pigment Red 88, Pigment Red 181, Pigment Red 198, Pigment Violet 36, and Pigment Violet 38.Representative examples of heterocyclic yellows include Pigment Yellow 1, Pigment Yellow 3, Pigment Yellow 12, Pigment Yellow 13, Pigment Yellow 14, Pigment Yellow 17, Pigment Yellow 65, Pigment Yellow 73, Pigment Yellow 74, Pigment Yellow 90, Pigment Yellow 110, Pigment Yellow 117, Pigment Yellow 120, Pigment Yellow 128, Pigment Yellow 138, Pigment Yellow 150, Pigment Yellow 151, Pigment Yellow 155, and Pigment Yellow 213. Such pigments are commercially available in powder or press cake form from many suppliers, including BASF Corporation, Engelhard Corporation, and Sun Chemical Corporation. Examples of usable black pigments include carbon pigments. Carbon pigments can be any commercially available carbon pigment that provides acceptable optical density and printing properties. Suitable carbon pigments for use in this system and method include, but are not limited to, carbon black, graphite, glassy carbon, charcoal, and combinations thereof. Such carbon pigments can be manufactured by various known methods, such as the channel process, contact process, furnace process, acetylene process, or thermal process, and are commercially available from vendors such as Cabot Corporation, Columbia Chemicals Company, Evonik, and EIDuPont de Nemours and Company.Suitable carbon black pigments include MONARCH® 1400, MONARCH® 1300, MONARCH® 1100, MONARCH® 1000, MONARCH® 900, MONARCH® 880, MONARCH® 800, MONARCH® 700, CAB-O-JET® 200, CAB-O-JET® 300, CAB-O-JET® 450, REGAL®, and BLACK. Examples of pigments include, but are not limited to, those manufactured by Cabot, such as PEARLS®, ELFTEX®, MOGUL®, and VULCAN® pigments; pigments manufactured by Columbia, such as RAVEN® 5000 and RAVEN® 3500; and pigments manufactured by Evonik, such as Color Black FW200, FW2, FW2V, FW1, FW18, FW5160, FW5170, Special Black 6, Special Black 5, Special Black 4A, Special Black 4, PRINTEX® U, PRINTEX® 140U, PRINTEX® V, and PRINTEX® 140V. Other pigments include CAB-O-JET 352K, CAB-O-JET 250C, CAB-O-JET 260M, CAB-O-JET 270Y, CAB-O-JET 465M, CAB-O-JET 470Y, and CAB-O-JET 480V (available from Cabot Corporation). Other pigments include Kodak Specialty Dispersion pigments, available from Kodak, Inc.These include Specialty Black Dispersion Type P2, Specialty Cyan Dispersion Type P2, Specialty Yellow Dispersion Type P2, Specialty Magenta Dispersion Type P3, Specialty Black Dispersion Type P4, Specialty Cyan Dispersion Type P1, Specialty Magenta Dispersion Type P1, and Specialty Yellow Dispersion Type P1. In the embodiment, the colorant is not any of the quinacridone pigments disclosed in U.S. Patent No. 9,359,522.

[0067] The above list of pigments includes unmodified pigment microparticles, small molecule-attached pigment microparticles, self-dispersing pigment microparticles, and polymer-dispersed pigment microparticles.

[0068] When forming an aqueous inkjet ink composition, the colorant may be provided as a colorant dispersion containing the colorant and a solvent (e.g., water). The colorant may also be in the form of particles, and may have an average particle size of 20 nm to 500 nm, 20 nm to 400 nm, or 30 nm to 300 nm.

[0069] Various amounts of colorants can be used in aqueous inkjet ink compositions. However, generally, the amount is selected such that the total solids content of the aqueous inkjet ink composition (generally provided by resin particles, colorants, and wax, if present) is 5% to 15% by weight, 6% to 12% by weight, or 7% to 10% by weight. (Here, weight % refers to (total weight of solids) / (total weight of aqueous inkjet ink composition) * 100.)

[0070] At least embodiments of the aqueous inkjet ink composition are characterized in that the resin particles are freely dispersed in the ink, in contrast to being attached, adsorbed, or coated on the colorant (e.g., pigment) of the ink. This can be confirmed by viscosity measurement. For example, the following examples illustrate experiments showing that the viscosity of an exemplary aqueous inkjet ink composition remains unchanged over a long period and at high temperature. "Unchanged" means within ±5% of the initial viscosity value. Similarly, this can be confirmed by measurements showing that 50 the particle size remains unchanged at high temperature over a long period (where "unchanged" has a meaning similar to the unchanged viscosity).

[0071] wax

[0072] Aqueous inkjet ink compositions may contain waxes. Examples of waxes include paraffin wax, polyethylene wax, polypropylene wax, microcrystalline wax, polyolefin wax, montan ester wax, and carnauba wax. Waxes having melting points in the range of 50°C to 150°C may be used. Nanoscale wax emulsions (e.g., with diameters of 1000 nm or less, 500 nm or less, or 100 nm or less) based on carnauba wax and paraffin wax may be used. Michelman waxes may be used (e.g., Michem Lube 103DI, 124, 124P135, 156, 180, 182, 190, 270R, 368, 511, 693, 723, 743, 743P, and 985, as well as Michem Emulsion 24414, 34935, 36840, 41740, 43040, 43240, 44730, 47950, 48040M2, 61355, 62330, 66035, 67235, 70750, 71150, 71152, 91735, 93235, 93335, 93935, and 94340). Waxes from Byk, including Aquacer 2500, Aquacer 507, Aquacer 513, Aquacer 530, Aquacer 531, Aquacer 532, Aquacer 535, Aquacer 537, Aquacer 539, and Aquacer 593, may also be used. In embodiments, the wax is an anionic nanoscale wax emulsion such as Michem Lube 190.

[0073] Various amounts of wax can be used in aqueous inkjet ink compositions. However, generally, the amount is selected so that the total solids content of the aqueous inkjet ink composition is 5% to 15% by weight, 6% to 12% by weight, or 7% to 10% by weight. (Here, weight % refers to (total weight of solids) / (total weight of aqueous inkjet ink composition) * 100.)

[0074] surfactant

[0075] Aqueous inkjet ink compositions may contain one or more surfactants. Examples of suitable surfactants include anionic surfactants (such as sodium lauryl sulfate (SLS), Dextrol OC-40, Strodex PK 90, ammonium lauryl sulfate, potassium lauryl sulfate, mireth sulfate, and sodium dioctyl sulfosuccinate series), nonionic surfactants (Surfynol® 104 series, Surfynol® 400 series, Dynol® 604, Dynol® 607, Dynol® 810, EnviroGem® 360, secondary alcohol ethoxylate series, e.g., Tergitol® 15-S-7, Tergitol® 15-S-9, TMN-6, TMN-100x, and Tergitol® NP-9, Triton® X-100, etc.), and cationic surfactants (Chemguard S-106A, Chemguard Examples include S-208M and Chemguard S-216M. Several fluorinated or silicone surfactants can be used, such as PolyFox™ TMPF-136A, 156A, 151N, Chemguard S-761p, S-764p, Silsurf™ A008, Siltec™ C-408, BYK 345, 346, 347, 348, and 349, and polyethersiloxane copolymer TEGO™ Wet-260, 270, and 500. Several amphoteric fluorinated surfactants, such as alkylbetaine fluorosurfactants or alkylamine oxide fluorosurfactants, such as Chemguard S-500 and Chemguard S-111, can also be used. Other surfactants that may be used include Surfynol PSA 336, Surfynol SE-F, and Surfynol 107L.

[0076] Various amounts of surfactants can be used in aqueous inkjet ink compositions. In embodiments, the surfactant is present in an amount ranging from 0.01% to 2% by weight. (Here, weight % refers to (total weight of surfactants) / (total weight of aqueous inkjet ink composition) * 100.) If two or more types of surfactants are used, these amounts refer to the total amount of surfactants.

[0077] additives

[0078] Various additives can be used in aqueous inkjet ink compositions to adjust their properties. Suitable additives include one or more of the following: biocides; fungicides; stabilizers; pH adjusters such as acids or bases, phosphates, carboxylates, sulfites, amine salts, and buffers; antifoaming agents; defoaming agents; and wetting agents. However, chelating agents (e.g., EDTA) are generally not included.

[0079] Various amounts of additives can be used in aqueous inkjet ink compositions. In embodiments, additives are present in amounts ranging from 0.01% to 5% by weight. (Here, % by weight refers to (total weight of additives) / (total weight of aqueous inkjet ink composition) * 100.) If two or more types of additives are used, these amounts refer to the total amount of additives.

[0080] In this embodiment, the aqueous inkjet ink composition does not contain a chelating agent (i.e., does not include one).

[0081] Aqueous inkjet ink compositions based on these resin particles do not necessarily require the addition of additives to further adjust viscosity. This means that the aqueous inkjet ink composition may not contain (i.e., does not include) water-soluble resins or emulsions, aqueous binders, polymer dispersants, or combinations thereof. This includes the possibility of excluding any of the water-soluble resins or emulsions, aqueous binders, or polymer dispersants described below. However, it is understood that in some embodiments, such compounds may be included. Finally, it should be noted that the terms water-soluble resin, water-soluble emulsion, aqueous binder, and polymer dispersant do not encompass the resin particles themselves. Exemplary water-soluble resins / emulsions are polyethylene glycol and polyvinylpyrrolidone.

[0082] Exemplary aqueous binders include Rhoplex I-1955, Rhoplex I-2426D, Rhoplex I-62, Rhoplex I-98, and Rhoplex E-1691, available from Rhohm & Haas. Others include Lucidene 190, Lucidene 400, and Lucidene 243, available from DSM Corporation; NeoCryl A-1110, NeoCryl A-2092, NeoCryl A-639, NeoRad R-440, NeoRad R-441, NeoRez N-55, 972, PVP K-15, PVP K-30, PVP K-60, and PVP K-85, available from ISP; and Ganex P-904LC and PVP / VA W-63. Other exemplary aqueous binders include those available from Johnson Polymers (BASF), such as Joncryl 537, Joncryl H538, and Joncryl H538.

[0083] Exemplary polymer dispersants include acrylic polymers such as styrene-acrylic copolymers, vinylpyrrolidone copolymers, urethane or polyurethane dispersions, and acrylic-urethane hybrid dispersions. More specific polymer dispersants include those available from Johnson Polymers (BASF), such as Joncryl® 671, Joncryl® 683, Joncryl® 296, Joncryl® 690, Joncryl HPD 296, Joncryl HPD96-E, Joncryl LMV 7085, and Joncryl 8082. Other dispersants include those described in European Patent No. 2097265, incorporated by reference for dispersant purposes, and U.S. Patent Application No. 2019284414, incorporated by reference for dispersant purposes.

[0084] Similarly, an aqueous inkjet ink composition may not contain any resin other than that provided by the resin particles (i.e., it may not contain any other resin). A single type of resin may be used. Similarly, an aqueous inkjet ink composition itself is generally not curable and therefore does not contain any initiator (i.e., it does not contain any). It should be noted that any other exclusions referenced above with respect to the resin particles and latex may apply to embodiments of the aqueous inkjet ink composition.

[0085] In some embodiments, the aqueous inkjet ink composition comprises (or consists of) a solvent system, resin particles, a colorant, and optionally one or more waxes and additives. In some embodiments, the ink composition comprises (or consists of) a solvent system, resin particles, a colorant, a wax, and optionally additives. In any of these embodiments, the additive may be selected from stabilizers, surfactants, anti-foaming agents, defoamers, wetting agents, and biocides. In any of these embodiments, the components may be selected from any of the solvent systems, resin particles, colorants, waxes, and additives disclosed herein. In any of these embodiments, the amounts of the components may be used as described above.

[0086] Aqueous inkjet ink compositions can be formed by combining and mixing desired components in desired amounts. An exemplary method includes adding one of the disclosed latex (or resin particles) to a colorant dispersion to form a first mixture, and adding a second mixture containing a solvent system and additives to the first mixture to form an aqueous inkjet ink composition. A third mixture containing wax may be added to the combined first and second mixtures. Mixing and / or heating may be used in the method. The aqueous inkjet ink composition may be filtered before use. Exemplary details are provided in the following examples.

[0087] characteristics

[0088] Aqueous inkjet ink compositions may be characterized by a variety of properties, including properties that indicate the composition can be used in an inkjet printing device to form a printed image. Aqueous inkjet ink compositions may have an initial viscosity (at 37°C and 1-6.3 seconds on the day the ink is formed). -1 Or 40-400 seconds -1It may be characterized by (measured over a frequency range). The initial viscosity may be in the range of 1 to 15 cP, including 2 to 10 cP and 3 to 8 cP. Such values ​​distinguish aqueous inkjet ink compositions from other compositions, such as paints, which have significantly higher initial viscosities, for example, exceeding 50 cp.

[0089] Aqueous inkjet ink compositions may be characterized by their water resistance. Wet abrasion resistance, as measured as described in the following examples, provides a measure of water resistance. In the examples, the aqueous inkjet ink composition exhibits a wet abrasion resistance of at least 10, 12, or 14 when measured using a droplet of about 4.5 ng of ink, or at least 15, 17, or 19 when measured using a droplet of about 9 ng of ink. These values ​​may refer to water resistance on paper substrates. As shown in the following examples, exemplary aqueous inkjet ink compositions exhibit even higher water resistance on metal substrates, such as aluminum, including a wet abrasion resistance of at least 30 when measured using a droplet of about 9 ng of ink.

[0090] Aqueous inkjet ink compositions may be characterized by their open-air stability. Such stability is measured by observing the time it takes for an aqueous inkjet ink composition to gel upon contact with air. This time can be measured as described in the following examples. In the examples, the time to gel is in the range of more than 3 hours, more than 4 hours, or 3 to 5 hours. As shown in the examples, the time to gel was extended by approximately 100% for exemplary aqueous inkjet ink compositions compared to comparative aqueous inkjet ink compositions containing resin particles formed from monomers that do not contain phosphate monomers.

[0091] Water-based inkjet ink compositions may be characterized by their long-term stability. A comparison of the initial viscosity of a water-based inkjet ink composition (measured on the day the ink is formed) with the viscosity value of the ink after storage at a high temperature (e.g., 60°C) for a certain period (e.g., 3, 7, or 14 days) provides a measure of such stability. As shown in the examples, exemplary water-based inkjet ink compositions have viscosity values ​​(at 37°C, 1-6.3 seconds) after storage at 60°C for 14 days (within ±5% of their respective initial viscosity values). -1 Or 40-400 seconds -1 It exhibits the following characteristics (measured over the frequency range).

[0092] Aqueous inkjet ink compositions may be used to form printed images. In embodiments, such a method involves ejecting droplets of any of the disclosed aqueous inkjet ink compositions onto a substrate to form an image thereon. The image may be of any form, e.g., text, graphics, etc. Such a method may further include incorporating the ink composition into an inkjet printing apparatus. The printing apparatus may use a thermal inkjet process, in which the ink composition in the nozzle is selectively heated in an image pattern, thereby ejecting droplets of the ink composition in an image pattern. Alternatively, the printing apparatus may use an acoustic inkjet process, in which droplets of the ink composition are ejected in an image pattern by an acoustic beam. In yet another embodiment, the printing apparatus may use a piezoelectric inkjet process, in which droplets of the ink composition are ejected in an image pattern by vibration of a piezoelectric vibrating element.

[0093] The method may include: injecting ink droplets in an image pattern onto an intermediate transfer member; heating the image to partially or completely remove the solvent; and transferring the ink composition in an image pattern from the intermediate transfer member to a final recording substrate. The intermediate transfer member may be heated to a temperature higher than the temperature of the final recording sheet but lower than the temperature of the ink composition in the printing apparatus. Offset or indirect printing processes are also disclosed, for example, in U.S. Patent No. 5,389,958, the disclosure of which is fully incorporated herein by reference.

[0094] Any suitable substrate or recording sheet can be used as the final recording sheet. This is a feature of at least one embodiment of an aqueous inkjet ink composition that is printable on both paper and non-paper substrates, such as metal substrates. Metal substrates include, for example, aluminum, brass, stainless steel, and copper. A substrate on which an image has been printed using any of the disclosed aqueous inkjet ink compositions is also included in this disclosure. [Examples]

[0095] The following examples are provided to further define the various types of this disclosure. These examples are for illustrative purposes only and are not intended to limit the scope of this disclosure. Unless otherwise stated, proportions and percentages are given by weight. As used herein, “room temperature” refers to a temperature of about 20°C to about 25°C.

[0096] Examples 1-4 A reactive surfactant solution was prepared by mixing 1.2 grams of Montello Hitenol AR 1025 with 35 grams of deionized water in a glass reactor. The reaction mixture was then purged with nitrogen for 30 minutes. The reactor was then continuously purged with nitrogen while stirring at 250 rpm. The reactor was then heated to 75°C and maintained there. Separately, 0.3 grams of ammonium persulfate (APS) initiator was dissolved in 5 grams of deionized water and added to the reactor.

[0097] Separately, monomer emulsions were prepared in the following manner: Styrene, butyl acrylate, methacrylic acid, 2-hydroxyethyl methacrylate ester (PAM) (Examples 1, 4), bis[2-(methacryloyloxy)ethyl]phosphate (B2MP) (Examples 2, 3, 4), glycerol formal methacrylate (Glyfoma) (Example 3), 1-dodecanethiol (DDT), poly(ethylene glycol) diacrylate (PEGDA250) (Example 1), Hitenol AR 1025, and deionized water were mixed to form emulsions. The amounts of these components used are shown in Table 1 below. The emulsified mixture was slowly supplied to the reactor for 2 hours, and the reaction was continued for 2 hours. An additional 0.15 g of APS initiator was dissolved in deionized water and added to the reactor over 10 minutes, and the reaction was continued for an additional 1.5 hours. The resulting latex was cooled to room temperature and diluted to pH 8.0 with a 30% aqueous dimethylethanolamine (DMEA) solution, or to pH 5.0 with a 5 M KOH solution, and then neutralized with 30% DMEA at pH 5-8.

[0098] The latex composition is shown in Table 1.

[0099] To perform seed microemulsion polymerization instead of seed-free polymerization, in a repeated experiment, a 5% monomer emulsion was supplied to the reactor over 10 minutes, followed by the addition of APS over 10 minutes. The mixture was held at a constant temperature for an additional 10 minutes, and the remaining monomer emulsion was supplied to the reactor over 2 hours. The subsequent steps were the same as in the seed-free emulsion polymerization described above.

[0100] Examples 5-7 (comparison) In these examples, the procedures of Examples 1-4 were repeated, as shown in Table 1, but different monomer mixtures were used. Specifically, phosphoric acid monomers were not used. Instead, hydrophilic monomers such as sodium 4-styrenesulfonate (4-NaSS) and, in Example 5, hydroxyethyl acrylate (HEA) were used. Colloidal silica was also used in Example 5. The latex formulations are shown in Table 1.

[0101] [Table 1]

[0102] Examples 8-15 Aqueous inkjet ink compositions were formed using the latex from Examples 3 and 4, and Comparative Examples 5-7. Specifically, the aqueous inkjet ink compositions of Examples 8-11 were formed using the CMYK latex from Example 3. The aqueous inkjet ink compositions of Comparative Examples 12-15 were formed using the CMYK latex from Comparative Example 5. The aqueous inkjet ink composition of Example 16 was formed using the latex from Example 3 and a black pigment. This ink was used to print on both metal and paper substrates. The aqueous inkjet ink composition of Example 17 was formed using the latex from Example 4 and a black pigment. This ink was used in the open-air stability test described below. The aqueous inkjet ink compositions of Comparative Examples 18 and 19 were formed using the latex and black pigment dispersion from Comparative Example 5. These inks also contain a chelating agent (EDTA). The aqueous inkjet ink compositions of Comparative Examples 20 and 21 were formed using the latex from Comparative Examples 6 and 7 and the black pigment, respectively. These inks were used in the open-air stability test described below. The following steps were used to form the aqueous inkjet ink composition, and the formulation is shown in Table 2.

[0103] 1. The pigment dispersion was added to deionized water and mixed using a Cowles blade impeller at a speed of approximately 650 RPM for about 15 minutes.

[0104] 2. The latex was slowly added to the pigment dispersion and mixed for about 20 minutes (Mixture A).

[0105] 3. In a separate beaker, the co-solvent and additives (humectant, stabilizer, defoamer / anti-foaming agent, surfactant, wetting agent, and adhesion promoter) were mixed to form a homogeneous mixture (mixture B).

[0106] 4. Mixture B was slowly added to mixture A. Once the addition was complete, the components were mixed for a further 20 minutes.

[0107] 5. Add the wax and continue mixing for another 15 minutes.

[0108] 6. After mixing, the aqueous inkjet ink composition was left at room temperature for approximately 60 minutes, and then its pH, conductivity, and surface tension were checked.

[0109] [Table 2]

[0110] Printing Test

[0111] Aqueous inkjet ink compositions were sprayed using a Dimatix DMP2800 printer on four different paper substrates, including McCoy® gloss #100, SUW Matte, Xerox® Bold, and Kodak photographic paper. The first set of key test parameters used was as follows: droplet mass = 4.5–4.8 ng (i.e., approximately 4.5 ng), droplet velocity = 6–7 m / sec, frequency = 5 kHz, voltage = 16–20 V, and print temperature = 20°C–40°C. The second set of key test parameters used was as follows: droplet mass = 8.5–9 ng (i.e., approximately 9 ng), droplet velocity = 9–11 m / sec, frequency = 5 kHz, voltage = 24–27 V, and print temperature = 20°C–40°C. The print parameter was 600 × 600 dpi printing. Measurements were performed using a PIAS II instrument, a personal image analysis system with a digital magnifying glass. To measure dot size and diameter, a high-resolution optical module with a field of view of approximately 3.2 mm × 2.4 mm and approximately 5 μm / pixel was used. Aqueous inkjet ink compositions that passed through continuous spraying for 10 to 30 minutes or more were considered to exhibit good waiting times. The results are shown in Table 4 and are discussed further below.

[0112] Metallic bonding test of latex

[0113] An aqueous solution of CaCl2 (10 mM) was prepared with deionized water. Aliquots of latex from Examples 3 and 4 (1.25 g, neutralized with KOH + DMEA) were mixed with calcium chloride solution (8.75 g) to prepare a 5% latex dispersion. The dispersion was mixed overnight at room temperature. The following day, the latex dispersion was thoroughly washed with an Amicon centrifuge filter unit (100,000 molecular weight cutoff (MWCO)) to remove all unbound calcium ions (at least 10 times, 30 minutes, 4000 rpm). The recovered sample was immersed in liquid nitrogen and freeze-dried overnight. This process formed a fine powder without any signs of aggregation. The dried latex particles were then digested in a mixture of nitric acid and hydrofluoric acid, and tested for Ca ions using inductively coupled plasma (ICP). The results are discussed further below.

[0114] Latex open air stability

[0115] The stability of aqueous inkjet ink compositions in open air was investigated by examining the initiation of structure formation (gelation), the gelation state, and visual evaluation of the fully gelled ink. For each examination, 4 grams of test ink, along with a control ink, were dispensed into identical Pyrex Petri dishes (60 mm diameter, 10 mm height) in a laboratory environment (32% relative humidity, 22°C) and inspected every 30 minutes over the entire 5-hour test period. Between inspections, the ink dishes were gently rotated to assess the rigor of structure formation. The weight of each sample was also measured, taking into account variations in temperature, humidity, and airflow in the test environment. For each measurement, the reported time for the initiation of gelation was corrected to account for an evaporation rate of 5.5% by weight per hour. The results are discussed further below.

[0116] Wet abrasion resistance (water resistance)

[0117] Water-based inkjet ink compositions were tested for wet abrasion resistance (20 double rubs using a wet Q-tip) (water resistance). Droplets (4.5 and 9 ng) of each water-based inkjet ink composition were printed on the desired substrate. The numbers in Table 4 indicate the number of double rubs (average of three measurements) obtained before any removal of the ink was observed. The results are shown in Table 4 and discussed further below.

[0118] result

[0119] Four paper substrates used for printing were examined using energy-dispersive X-ray (EDX) features on an electron microscope. The results are shown in Table 3, indicating that all four substrates contained large amounts of metal (calcium and aluminum). The ICP results also showed that the latexes of Examples 1-4 exhibited strong chelating ability. For example, the latex of Example 4 showed approximately 4000 ppm of calcium ion uptake, while only the control latex (the latex of Example 4 without calcium ion incubation) showed 3 ppm of calcium uptake.

[0120] [Table 3]

[0121] As shown in Table 4, the aqueous inkjet ink compositions of Examples 8-11 exhibited excellent spray (no misdirection and satellites, spraying for more than 30 minutes), waiting time, and decapping time. They also showed improved water resistance (both approximately 4.5 ng and approximately 9 ng droplet mass) and mechanical properties compared to the aqueous inkjet ink compositions of Comparative Examples 12-15 and other commercially available benchmark inks.

[0122] [Table 4]

[0123] In particular, the aqueous inkjet ink compositions of Examples 11 and 17 showed substantially improved open-air stability, as evidenced by the extended flow time and delay in the initiation of structure formation (gelation) under open-air conditions. Specifically, while the comparative aqueous inkjet ink compositions of Comparative Examples 15 and 20 exhibited the initiation of gelation within a time range of 2 to 2.5 hours, those of Examples 11 and 17 exhibited the initiation of gelation within more than 4.5 hours. This represents an improvement of almost 100%.

[0124] Additional experiments were conducted to evaluate the redispersion properties and long-term stability of the aqueous inkjet ink compositions. Regarding redispersion properties, 20 μL of the aqueous inkjet ink compositions from Examples 8-11 and a commercially available ink were placed in Petri dishes and dried at room temperature for 5 days. Then, 7 mL of the ink co-solvent mixture was gently added to each dish, and the dishes were allowed to stand for 45 minutes. Redispersion was evaluated by observing the degree of spreading of the colored ink in the co-solvent mixture using visual inspection. The aqueous inkjet ink compositions from Examples 8-11 spread rapidly, with significant dispersion after 15 minutes and almost complete dispersion after 45 minutes. The commercially available inks dispersed much more slowly. Their spreading after 45 minutes was approximately half that of the aqueous inkjet ink compositions from Examples 8-11. Finally, after rinsing with the solvent, the aqueous inkjet ink compositions from Examples 8-11 left no rings, while the commercially available inks left dry rings of CMY colors.

[0125] Regarding long-term stability, the aqueous inkjet ink compositions were subjected to accelerated aging tests at 60°C. The viscosity of the aqueous inkjet ink compositions was measured at 37°C in two frequency ranges using an Ares G2 TA instrument at various time points as shown in Table 5 below. The results show that the viscosity of the aqueous inkjet ink composition of Example 11 remained virtually unchanged after 14 days at 60°C (respectfully within 3.8% and 2.9% of the initial viscosity values ​​in the first and second frequency ranges). These results also confirm that the latex resin particles formed in the aqueous inkjet ink composition of Example 11 are freely dispersed throughout the ink and do not adsorb, adhere, or coat the colorants in the composition. In contrast, the aqueous inkjet ink compositions of Comparative Examples 18 and 19 exhibited severe instability.

[0126] [Table 5]

[0127] Finally, printing tests were conducted to demonstrate that the latex-based aqueous inkjet ink compositions of Examples 1-4 could be printed on non-paper substrates, including metal substrates. For example, the aqueous inkjet ink composition of Example 8 was successfully printed on aluminum, brass, stainless steel, and copper. Additional printing tests were performed by printing the aqueous inkjet ink composition of Example 16 on aluminum. Microscopic images of dots, lines, and solid blocks printed with this ink showed good spread. Dot diameters of 51 μm and line widths of 47 μm were obtained. In addition, the printing on aluminum was exceptionally durable and resistant to both dry and wet friction. Water resistance results using a droplet size of approximately 9 ng exceeded 30 double frictions (substantially perceived infinite water resistance). In contrast, commercially available inks dissolved in a wet cotton swab within the first three double frictions.

[0128] The term “exemplary” is used herein to mean an example, case, or representation. Any embodiment or design described herein as “exemplary” is not necessarily construed as being preferable or advantageous to other embodiments or designs. Furthermore, for the purposes of this disclosure, unless otherwise specified, “a” or “an” means “one or more.”

[0129] Where not already included, all numerical values ​​of parameters in this disclosure are referred to by the term “approximately,” meaning approximate. This includes variations inherent in the measurement of the relevant parameters as understood by those skilled in the art. This also includes the exact values ​​of the disclosed numerical values ​​and the rounded values ​​of the disclosed numerical values.

[0130] The foregoing description of exemplary embodiments of the Disclosure is provided for illustrative and explanatory purposes only. It is not intended to be exhaustive or to limit the Disclosure to the exact form disclosed, and modifications and variations are possible in light of the above teachings or may be obtained from practices of the Disclosure. Embodiments are selected and described in order to illustrate the principles of the Disclosure and to enable those skilled in the art to utilize the Disclosure in various embodiments as a practical application of the Disclosure, and with various modifications suitable for the particular intended use. The scope of the Disclosure is intended to be defined by the claims and equivalents thereof appended herein.

Claims

1. A latex comprising water and resin particles, the resin particles comprising: A latex comprising water and resin particles, the latex comprising the polymerization product of a reactant comprising styrene, butyl acrylate, 2-hydroxyethyl methacrylate phosphate ester, and / or bis[2-(methacryloyloxy)ethyl]phosphate, methacrylic acid, an anionic ether sulfate reactive surfactant, a chain transfer agent, an initiator, and optionally dioxane / dioxolane monomers and / or polyfunctional monomers.

2. The latex of claim 1 , wherein the latex is colorant-free.

3. 10. The latex of claim 1, wherein the latex does not include boric acid, diglycolic acid, a chelating agent, or a combination thereof.