BR102019020639B1 - TONER COMPOSITION, METHOD FOR PRODUCING A TONER COMPOSITION AND ARTICLE COMPRISING A PRINTED IMAGE - Google Patents

Abstract

A toner composition includes toner particles having a resin and a colorant, the composition further including an infrared luminescent marker disposed on the surface of the toner particles. A method for producing a toner composition includes toner particles having a resin and a colorant, the composition further including an infrared luminescent marker disposed on the surface of the toner particles, the method including blending the toner particles with a surface additive package that includes the infrared luminescent marker. An article includes a printed image disposed on the article, the printed image being produced with a toner composition including toner particles having a resin and a colorant, the composition further including an infrared luminescent marker disposed on the surface of the toner particles, the printed image enabling authentication of the article by infrared detection of the infrared luminescent marker.

Description

[0001] The present disclosure relates to toners. In particular, the present disclosure relates to toner additives comprising marker materials for security applications.

[0002] The development of security-enabling printing techniques is desirable for anti-counterfeiting, brand protection, and security packaging applications. Various means of incorporating marker materials for such applications have been developed. For example, infrared marker materials have been incorporated into the core toner particle structure during the emulsion aggregation process. Other means of incorporating marker materials include encapsulating toner particles with marker material or using marker particle aggregates in conjunction with toner.

[0003] In some aspects, embodiments of the present invention relate to toner compositions comprising toner particles comprising a resin and a colorant, the toner composition further comprising an infrared luminescent marker disposed on the surface of the toner particles.

[0004] In some aspects, embodiments of the present invention relate to methods for producing a toner composition comprising toner particles comprising a resin and a colorant, the toner composition further comprising an infrared luminescent marker disposed on the surface of the toner particles, the method comprising blending the toner particles with a surface additive package comprising the infrared luminescent marker.

[0005] In some aspects, embodiments of the present invention relate to articles comprising a printed image disposed on the article, the printed image produced with a toner composition comprising toner particles comprising a resin and a colorant, the toner composition further comprising an infrared luminescent marker disposed on the surface of the toner particles, the printed image enabling authentication of the article by infrared detection of the infrared luminescent marker.

[0006] Figure 1A shows triboelectric charging graphical plots for three clear toner samples at three different marker concentrations CL-IR-00 = 0%, CL-IR-01 = 0.05 wt %, CL-IR-02 = 0.1 wt % under different temperature/humidity conditions A (26.7 °C/80% RH), B (21.1 °C/50% RH), J (21.1 °C/10% RH); vertical axis (μC/g).

[0007] Figure 1B shows triboelectric charging graphical plots for three yellow toner samples at three different marker concentrations Y-IR-00 = 0%, Y-IR-01 = 0.05 wt %, Y-IR-02 = 0.1 wt % under different temperature/humidity conditions A (26.7 °C/80% RH), B (21.1 °C/50% RH), J (21.1 °C/10% RH); vertical axis (μC/g).

[0008] Figure 1C shows triboelectric charging graphical plots for three magenta toner samples at three different marker concentrations M-IR-00 = 0%, M-IR-01 = 0.1 wt %, M-IR-02 = 0.5 wt % under different temperature/humidity conditions A (26.7 °C/80% RH), B (21.1 °C/50% RH), J (21.1 °C/10% RH); vertical axis (μC/g).

[0009] Figure 1D shows triboelectric charging graphical plots for five cyan toner samples at five different marker concentrations C-IR-00 = 0%, C-IR-01 = 0.1 wt %, C-IR-02 = 0.5 wt %, C-IR-03 = 1 wt %, C-IR-04 = 2 wt %, under different temperature/humidity conditions A (26.7 °C/80% RH), B (21.1 °C/50% RH), J (21.1 °C/10% RH); vertical axis (μC/g).

[0010] Figure 1E shows triboelectric charging graphical plots for five black toner samples at five different marker concentrations K-IR-00 = 0%, K-IR-01 = 0.1 wt %, K-IR-02 = 0.5 wt %, K-IR-03 = 2 wt %, K-IR-04 = 5 wt %, under different temperature/humidity conditions A (26.7 °C/80% RH), B (21.1 °C/50% RH), J (21.1 °C/10% RH); vertical axis (μC/g).

[0011] Figure 2 shows a plot of percent reflectance versus wavelength for various color toners comprising markers listed in Table 1.

[0012] Embodiments of the present invention provide toner compositions comprising toner particles having marker materials disposed on their surface. The marker materials may comprise inorganic infrared luminescent ceramic particles. Advantageously, the marker particles do not interfere with toner loading and exhibit essentially no impact on color at threshold loading levels sufficient for detection. Furthermore, the marker is readily incorporated during normal toner particle blending processing when other surface additives, such as charge control agents, are added, thus eliminating the need for any additional processing steps.

[0013] In some embodiments, toner compositions are provided which comprise toner particles comprising a resin and a colorant and an infrared luminescent marker disposed on the surface of the toner particles. In embodiments, the toner particles are prepared through a chemical process. For example, the toner particles can be the product of an emulsion/aggregation (EA) process. Other chemical processes for toner particle formation include, without limitation, suspension polymerization, polyester stretching polymerization, and chemical milling. In certain embodiments, the toner particles can be prepared through conventional methods, such as through melt mixing and spraying (and/or milling).

[0014] In embodiments, the marker is a ceramic. In embodiments, the ceramic comprises oxides of silicon, yttrium, lithium, ytterbium, and cerium.

[0015] In embodiments, the marker is nanoparticulate.

[0016] In embodiments, the marker is present in an amount of about 0.05 parts per hundred to about 5 parts per hundred of toner particles. In embodiments, the toner color is clear or yellow and the marker is present in a concentration in a range of about 0.05 parts per hundred to about 0.1 parts per hundred of toner particles. In embodiments, the toner color is magenta and the marker is present in about 0.5 parts per hundred of toner particles. In embodiments, the toner color is cyan and the marker is present in about 1 to about 2 parts per hundred of toner particles. In embodiments, the toner color is black and the marker is present in about 5 parts per hundred of toner particles.

[0017] In embodiments, the toner particles comprise a styrene acrylate polymer, an amorphous polyester, a crystalline polyester, or combinations thereof.

[0018] In embodiments, methods are provided for producing a toner composition comprising toner particles comprising a resin and a colorant, the toner composition further comprising an infrared luminescent marker disposed on the surface of the toner particles, the method comprising blending the toner particles with a surface additive package comprising the infrared luminescent marker.

[0019] In embodiments, the surface additive package further comprises a charge control agent.

[0020] In embodiments, the marker is a nanoparticulate ceramic comprising oxides of silicon, yttrium, lithium, ytterbium, and cerium.

[0021] In embodiments, the marker is present in an amount of about 0.05 parts per hundred to about 5 parts per hundred toner particles.

[0022] In some embodiments, articles are provided that comprise a printed image disposed on the articles, the printed image produced with a toner composition comprising toner particles comprising a resin and a colorant, the toner composition further comprising an infrared luminescent marker disposed on the surface of the toner particles, the printed image enabling authentication of the articles by infrared detection of the infrared luminescent marker.

[0023] In embodiments, the article is an identification badge. In embodiments, the article is a form of currency. Other articles include, without limitation, application on labels for a branded product, document with invisible encrypted information, and infrared sensor printed on woven textile products or polymer films.

[0024] In embodiments, the marker is a nanoparticulate ceramic comprising oxides of silicon, yttrium, lithium, ytterbium, aluminum, titanium, cerium, zinc, and zirconium.

[0025] In embodiments, the marker is present in an amount of about 0.05 parts per hundred to about 5 parts per hundred toner particles.

[0026] In embodiments, methods are provided that comprise printing an image onto a substrate with a toner composition comprising toner particles comprising a colorant and an infrared luminescent marker disposed on the surface of the toner particles, wherein the marker serves for security purposes to authenticate the substrate.

Resin

[0027] In embodiments, the toner particles can comprise a resin. The resin can comprise a polyester, a styrene acrylate, or combinations thereof. In embodiments, the polyester is amorphous, crystalline, or combinations thereof. In embodiments, the resin comprises a high molecular weight amorphous polyester, a low molecular weight amorphous polyester, and a crystalline polyester. The toners of the present disclosure can include a latex resin in combination with a pigment. Although the latex resin can be prepared by any method within the competence of those skilled in the art, in embodiments, the latex resin can be prepared by emulsion polymerization methods, which includes semi-continuous emulsion polymerization, and the toner can include emulsion aggregation toners. Emulsion aggregation involves aggregation of both latex and submicron pigment particles into toner-sized particles, with the growth in particle size being, for example, in embodiments, from about 1 micron to about 15 microns.

[0028] Any monomer suitable for preparing a latex for use in a toner may be used. As noted above, in embodiments, the toner may be produced via emulsion aggregation. Suitable monomers useful in forming a latex emulsion, and thus the resulting latex particles in the latex emulsion, include, but are not limited to, styrenes, acrylates, methacrylates, butadienes, isoprenes, acrylic acids, methacrylic acids, acrylonitriles, combinations thereof, and the like.

[0029] In embodiments, the latex resin may include at least one polymer. In embodiments, the at least one may be from about one to about twenty, and in certain embodiments, from about three to about ten. Exemplary polymers include styrene acrylates, styrene butadienes, styrene methacrylates, and more specifically, poly(styrene-alkyl acrylate), poly(styrene-1,3-diene), poly(styrene-alkyl methacrylate), poly(styrene-alkyl acrylate-acrylic acid), poly(styrene-alkyl styrene-1,3-diene-acrylic acid), poly(styrene-alkyl methacrylate-acrylic acid), poly(alkyl-methacrylate-alkyl acrylate), poly(alkyl-methacrylate-aryl acrylate), poly(aryl-methacrylate-alkyl acrylate), poly(alkyl methacrylate-acrylic acid), poly(alkyl acrylate-acrylonitrile-styrene-alkyl acrylic), poly(acid styrene-1,3-diene-acrylonitrile-acrylic acid), poly(acrylate-acrylonitrile-alkyl acrylic acid), poly(styrene-butadiene), poly(methyl-styrene-butadiene), poly(methyl methacrylate-butadiene), poly(ethyl methacrylate-butadiene), poly(propyl methacrylate-butadiene), poly(butyl methacrylate-butadiene), poly(methyl acrylate-butadiene), poly(ethyl acrylate-butadiene), poly(propyl acrylate-butadiene), poly(butyl acrylate-butadiene), poly(styrene-isoprene), poly(methylstyrene-isoprene), poly(methyl methacrylate-isoprene), poly(ethyl methacrylate-isoprene), poly(propyl methacrylate-isoprene), poly(butyl methacrylate-isoprene), poly(methyl isoprene acrylate), poly(ethyl isoprene acrylate), poly(propyl isoprene acrylate), poly(butyl isoprene acrylate), poly(styrene-propyl acrylate), poly(styrene-butyl acrylate), poly(styrene-butadiene-acrylic acid), poly(styrene-butadiene-methacrylic acid), poly(styrene-butadiene-acrylonitrile-acrylic acid), poly(styrene-butyl acrylate-acrylic acid), poly(styrene-butyl acrylate-methacrylic acid), poly(styrene-butyl acrylate-acrylonitrile), poly(styrene-butyl acrylate-acrylonitrile-acrylic acid), poly(styrene-butadiene), poly(styrene-isoprene), poly(styrene-butadiene methacrylate), poly(styrene-butadiene) styrene-butyl acrylate-acrylic acid), poly(styrene-butyl methacrylate-acrylic acid), poly(butyl acrylate-butyl methacrylate), poly(butyl methacrylate-acrylic acid), poly(acrylonitrile-butyl acrylate-acrylic acid), and combinations thereof. The polymer may be block, random, or alternating copolymers. Furthermore, polyester resins obtained from the reaction products of bisphenol A and propylene oxide or propylene carbonate, and in particular, which include such polyesters followed by the reaction of the resulting product with fumaric acid (as disclosed in U.S. Patent No. 5,227,460, the disclosure of which is incorporated herein by reference in its entirety), and branched polyester resins resulting from the reaction of dimethyl terephthalate with 1,3-butanediol, 1,2-propanediol, and pentaerythritol, may also be used.

[0030] In embodiments, a poly(styrene-butyl acrylate) may be used as the latex. The glass transition temperature of such a latex may be from about 35°C to about 75°C, in embodiments, from about 40°C to about 70°C.

[0031] The toner compositions may include core particles comprising an amorphous polyester resin. The amorphous polyester resin may be formed by reacting a diol with a diacid in the presence of an optional catalyst. Examples of diacids or diesters that include vinyl diacids or vinyl diesters used for the preparation of amorphous polyesters include dicarboxylic acids or diesters such as terephthalic acid, phthalic acid, isophthalic acid, fumaric acid, dimethyl fumarate, dimethyl itaconate, cis-acid, 1,4-diacetoxy-2-butene, diethyl fumarate, diethyl maleate, maleic acid, succinic acid, itaconic acid, succinic acid, succinic anhydride, dodecylsuccinic acid, dodecylsuccinic anhydride, glutaric acid, glutaric anhydride, adipic acid, pimelic acid, suberic acid, azelaic acid, dodecane diacid, dimethyl terephthalate, diethyl terephthalate, dimethylisophthalate, diethylsophthalate, dimethylphthalate, phthalic anhydride, diethyl phthalate, dimethylsuccinate, fumarate, dimethylmaleate, dimethylglutarate, dimethyladipate, dimethyl dodecylsuccinate, and combinations thereof. The organic diacid or diester may be present, for example, in an amount of about 40 to about 60 mole percent of the resin, in some embodiments, about 42 to about 52 mole percent of the resin, in some embodiments, about 45 to about 50 mole percent of the resin.

[0032] Examples of diols that can be used in generating the amorphous polyester include 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, pentanediol, hexanediol, 2,2-dimethylpropanediol, 2,2,3-trimethylhexanediol, heptanediol, dodecanediol, bis(hydroxyethyl)-bisphenol A, bis(2-hydroxypropyl)-bisphenol A, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, xylene dimethanol, cyclohexanediol, diethylene glycol, bis(2-hydroxyethyl)oxide, dipropylene glycol, dibutylene, and combinations thereof. The amount of organic diol selected may vary, and may be present, for example, in an amount of about 40 to about 60 mole percent of the resin, in embodiments, of about 42 to about 55 mole percent of the resin, in embodiments, of about 45 to about 53 mole percent of the resin.

[0033] Polycondensation catalysts that can be used in the formation of the crystalline or amorphous polyesters include tetraalkyl titanates, dialkyltin oxides such as dibutyltin oxide, tetraalkyltins such as dibutyltin dilaurate, and dialkyltin oxide hydroxides such as butyltin oxide hydroxide, aluminum alkoxides, alkyl zinc, dialkyl zinc, zinc oxide, stannous oxide, or combinations thereof. Such catalysts can be used in amounts of, for example, about 0.01 mole percent to about 5 mole percent based on the starting diacid or diester used to generate the polyester resin. In embodiments, suitable amorphous resins include polyesters, polyamides, polyimides, polyolefins, polyethylene, polybutylene, polyisobutyrate, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, polypropylene, combinations thereof, and the like. Examples of amorphous resins that may be used include alkali sulfonated polyester resins, branched alkali sulfonated polyester resins, alkali sulfonated polyimide resins, and branched alkali sulfonated polyimide resins. Alkaline sulfonated polyester resins may be useful in embodiments such as the alkali or metal salts of copoly(ethylene terephthalate)-copoly(ethylene-5-sulfoisophthalate), copoly(propylene terephthalate)-copoly(propylene-5-sulfoisophthalate), copoly(diethylene terephthalate)-copoly(diethylene-5-sulfoisophthalate), copoly(propylene-diethylene terephthalate)-copoly(propylene-diethylene-5-sulfoisophthalate), copoly(propylene-butylene terephthalate)-copoly(propylene-butylene-5-sulfoisophthalate), copoly(bisphenol-A-propoxylated fumarate)-copoly(bisphenol-A-propoxylated 5-sulfoisophthalate), copoly(bisphenol-A-fumarate ethoxylated)-copoly(ethoxylated bisphenol-A-5-sulfoisophthalate) and copoly(ethoxylated bisphenol-A-maleate)-copoly(ethoxylated bisphenol-A-5-sulfoisophthalate), where the alkali metal is, for example, a sodium, lithium or potassium ion.

[0034] In embodiments, as noted above, an unsaturated amorphous polyester resin may be utilized as a latex resin. Exemplary unsaturated amorphous polyester resins include, but are not limited to, poly(propoxylated bisphenol co-fumarate), poly(ethoxylated bisphenol co-fumarate), poly(butyloxylated bisphenol co-fumarate), poly(propoxylated bisphenol co-ethoxylated bisphenol co-fumarate), poly(1,2-propylene fumarate), poly(propoxylated bisphenol co-maleate), poly(ethoxylated bisphenol co-maleate), poly(butyloxylated bisphenol co-maleate), poly(propoxylated bisphenol co-ethoxylated bisphenol co-maleate), poly(1,2-propylene maleate), poly(propoxylated bisphenol co-itaconate), poly(ethoxylated bisphenol co-itaconate), poly(prop ... butyloxylated bisphenol), poly(bisphenol co-ethoxylated co-propoxylated bisphenol co-itaconate), poly(1,2-propylene itaconate) and combinations thereof.

[0035] In embodiments, a suitable polyester resin may be an amorphous polyester such as a poly(propoxylated bisphenol A co-fumarate) resin having the following Formula (I): where m can be from about 5 to about 1,000.

[0036] An example of a linear propoxylated bisphenol A fumarate resin that can be used as a latex resin is available under the trade name SPARII from Resana S/A Indústrias Químicas, São Paulo, Brazil. Other propoxylated bisphenol A fumarate resins that can be used and are commercially available include GTUF and FPESL-2 from Kao Corporation, Japan, and EM181635 from Reichhold, Research Triangle Park, N.C., and the like.

[0037] In embodiments, the resins used as the resin binder can have a glass transition temperature of about 30°C to about 80°C, in embodiments, from about 35°C to about 70°C. In further embodiments, the resins used as the resin binder can have a melt viscosity of about 10 to about 1,000,000 Pa.S at about 130°C, in embodiments, from about 20 to about 100,000 Pa.S.

[0038] Crystalline resins, which are available from a variety of sources, can be prepared through a polycondensation process by reacting an organic diol and an organic diacid in the presence of a polycondensation catalyst. Generally, a stoichiometric equimolar ratio of organic diol and organic diacid is used; however, in some cases, where the boiling point of the organic diol is from about 180°C to about 230°C, an excess amount of diol may be used and removed during the polycondensation process. The amount of catalyst used varies and can be selected in an amount, for example, from about 0.01 to about 1 mole percent of the resin. Additionally, in place of the organic diacid, an organic diester can also be selected, in which an alcohol byproduct is generated.

[0039] Examples of organic diols include aliphatic diols having from about 2 to about 36 carbon atoms, such as 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, and the like; alkali sulfoaliphatic diols, such as sodium 2-sulfo-1,2-ethanediol, lithium 2-sulfo-1,2-ethanediol, potassium 2-sulfo-1,2-ethanediol, sodium 2-sulfo-1,3-propanediol, lithium 2-sulfo-1,3-propanediol, potassium 2-sulfo-1,3-propanediol, mixtures thereof, and the like. The aliphatic diol is, for example, selected in an amount of about 45 to about 50 mole percent of the resin, and the alkali sulfoaliphatic diol can be selected in an amount of about 1 to about 10 mole percent of the resin.

[0040] Examples of organic diacids or diesters selected for preparing the crystalline polyester resins include oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, cyclohexane-dicarboxylic acid, malonic acid, and mesaconic acid, a diester or anhydride thereof; and an alkali organic sulfo-diacid, such as the sodium, lithium, or potassium salt of dimethyl-5-sulfoisophthalate, dialkyl-5-sulfoisophthalate-4-sulfo-1,8-naphthalic anhydride, 4-sulfo-phthalic acid, dimethyl-4-sulfo-phthalate, dialkyl-4-sulfo-phthalate, 4-sulfophenyl-3,5-dicarbomethoxybenzene, 6-sulfo-2-naphthyl-3,5-dicarbomethoxybenzene, sulfo-terephthalic acid, dimethyl-sulfo-terephthalate, 5-sulfo-isophthalic acid, dialkyl-sulfo-terephthalate, sulfoethanediol, 2-sulfopropanediol, 2-sulfobutanediol, 3-sulfopentanediol, 2-sulfohexanediol, 3-sulfo-2-methyl- pentanediol, 2-sulfo-3,3-dimethylpentanediol, sulfo-p-hydroxybenzoic acid, N,N-bis(2-hydroxyethyl)-2-amino-ethane sulfonate, or mixtures thereof. The organic diacid is selected in an amount, for example, from about 40 to about 50 mole percent of the resin, and the alkaline sulfoaliphatic diacid can be selected in an amount of from about 1 to about 10 mole percent of the resin. An alkaline sulfonated polyester resin can be selected for the third branched amorphous latex resin. Examples of suitable alkali sulfonated polyester resins include the alkali or metal salts of copoly(ethylene terephthalate)-copoly(ethylene-5-sulfoisophthalate), copoly(propylene terephthalate)-copoly(propylene-5-sulfoisophthalate), copoly(diethylene terephthalate)-copoly(diethylene-5-sulfoisophthalate), copoly(propylene-diethylene terephthalate)-copoly(propylene-diethylene-5-sulfoisophthalate), copoly(propylene-butylene terephthalate)-copoly(propylene-butylene-5-sulfoisophthalate), copoly(bisphenol-A-propoxylated fumarate)-copoly(bisphenol-A-propoxylated 5-sulfoisophthalate), copoly(bisphenol-A-fumarate ethoxylated)-copoly(ethoxylated bisphenol-A-5-sulfoisophthalate) and copoly(ethoxylated bisphenol-A-maleate)-copoly(ethoxylated bisphenol-A-5-sulfoisophthalate), and wherein the alkali metal is, for example, a sodium, lithium or potassium ion.

[0041] Examples of crystalline-based polyester resins include alkaline copoly(5-sulfo-isophthaloyl)-copoly(ethylene-adipate), alkaline copoly(5-sulfo-isophthaloyl)-copoly(propylene-adipate), alkaline copoly(5-sulfo-isoftaloyl)-copoly(butylene-adipate), alkaline copoly(5-sulfo- alkaline isophthaloyl)-copoly(pentylene-adipate), alkaline copoly(5-sulfo-isophthaloyl)-alkaline copoly(octylene-adipate), alkaline copoly(5-sulfo-isophthaloyl)-copoly(ethylene-adipate), alkaline copoly(5-sulfo-isoftaloyl)-copoly(propylene-adipate), alkaline copoly(5-sulfo-isophthaloyl)-copoly(butylene-adipate), alkaline copoly(5-sulfo-isophthaloyl)-copoly(pentylene-adipate), alkaline copoly(5-sulfo-isophthaloyl)-copoly(hexylene-adipate), alkaline copoly(5-sulfo-isophthaloyl)-copoly(octylene-adipate) [...] alkaline copoly(octylene succinate), alkaline copoly(5-sulfo-isophthaloyl)- alkaline copoly(ethylene-sebacate), alkaline copoly(5-sulfo-isophthaloyl)- alkaline copoly(propylene-sebacate), alkaline copoly(5-sulfo-isophthaloyl)- copoly(butylene-sebacate), copoly(5-sulfo-isophthaloyl)- copoly(pentylene-sebacate) [...] alkaline copoly(propylene-adipate), alkali poly(5-sulfo-isophthaloyl)-poly(butylene adipate), alkali poly(5-sulfo-isophthaloyl)-poly(pentylene adipate), alkali poly(5-sulfo-isophthaloyl)-poly(hexylene adipate), poly(octylene adipate); and wherein alkali is a sodium, lithium, or potassium metal, and the like. In embodiments, the alkali metal is lithium.

[0042] The crystalline resin may be present, for example, in an amount from about 5 to about 50 weight percent of the toner components, in embodiments, from about 10 to about 35 weight percent of the toner components. The crystalline resin may have various melting points, for example, from about 30°C to about 120°C, in embodiments, from about 50°C to about 90°C. The crystalline resin can have a number average molecular weight (Mn), as measured by gel permeation chromatography (GPC), e.g., from about 1,000 to about 50,000, in embodiments, from about 2,000 to about 25,000, and a weight average molecular weight (Mw), e.g., from about 2,000 to about 100,000, in embodiments, from about 3,000 to about 80,000, as determined by gel permeation chromatography using polystyrene standards. The molecular weight distribution (Mw/Mn) of the crystalline resin can be, e.g., from about 2 to about 6, in embodiments, from about 3 to about 4.

Surfactants

[0043] In embodiments, the latex can be prepared in an aqueous phase that contains a surfactant or co-surfactant. Surfactants that can be used with the resin to form a latex dispersion can be ionic or nonionic surfactants in an amount of from about 0.01 to about 15 weight percent solids, and in embodiments from about 0.1 to about 10 weight percent solids.

[0044] Anionic surfactants that may be used include sulfates and sulfonates, sodium dodecyl sulfate (DSS), sodium dodecylbenzene sulfonate, sodium dodecylnaphthalene sulfate, dialkyl benzenealkyl sulfates and sulfonates, acids such as abietic acid available from Aldrich, NEOGEN R™, NEOGEN SC™, obtained from Daiichi Kogyo Seiyaku Co., Ltd., combinations thereof, and the like. Other suitable anionic surfactants include, in embodiments, DOWFAX™ 2A1, an alkyldiphenyloxide disulfonate from The Dow Chemical Company, and/or TAYCA POWER BN2060 from Tayca Corporation (Japan), which are branched sodium dodecylbenzene sulfonates. Combinations of these surfactants and any of the aforementioned anionic surfactants may be used in embodiments.

[0045] Examples of cationic surfactants include, but are not limited to, ammonias, e.g., alkylbenzyldimethylammonium chloride, dialkylbenzenealkylammonium chloride, lauryltrimethylammonium chloride, alkylbenzylmethylammonium chloride, alkylbenzyldimethylammonium bromide, benzalkonium chloride, C12, C15, C17 trimethylammonium bromides, combinations thereof, and the like. Other cationic surfactants include cetylpyridinium bromide, halide salts of quaternized polyoxyethylalkylamines, dodecylbenzyltriethylammonium chloride, MIRAPOL and ALKAQUAT available from Alkaril Chemical Company, SANISOL (benzalkonium chloride), available from Kao Chemicals, combinations thereof, and the like. In embodiments a suitable cationic surfactant includes SANISOL B-50 available from Kao Corp., which is primarily a benzyldimethylalkonium chloride.

[0046] Examples of nonionic surfactants include, but are not limited to, alcohols, acids, and ethers, e.g., polyvinyl alcohol, polyacrylic acid, metallose, methyl cellulose, ethyl cellulose, propyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, polyoxyethylene cetyl ether, polyoxyethylene lauryl ether, polyoxyethylene octyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene sorbitan monolaurate, polyoxyethylene stearyl ether, polyoxyethylene nonylphenyl ether, dialkylphenoxy poly(ethyleneoxy)ethanol, combinations thereof, and the like. In commercially available surfactants from Rhone-Poulenc, such as IGEPAL CA-210™, IGEPAL CA-520™, IGEPAL CA-720™, IGEPAL CO-890™, IGEPAL CO-720™, IGEPAL CO-290™, IGEPAL CA-210™, ANTAROX 890™ and ANTAROX 897™ can be used.

[0047] The choice of particular surfactants or combinations thereof, as well as the quantities of each to be used, are within the competence of those skilled in the art.

Latex prepared by emulsion polymerization with initiators

[0048] In embodiments, initiators may be added for latex formation. Examples of suitable initiators include water-soluble initiators such as ammonium persulfate, sodium persulfate, and potassium persulfate, and organic-soluble initiators that include organic peroxides and azo compounds that include Vazo peroxides such as VAZO 64™, 2-methyl-2-2-azobis propanenitrile, VAZO 88™, 2-2′-azobis isobutyramide dehydrate, and combinations thereof. Other water-soluble initiators that may be used include azoamidine compounds, for example 2,2‘-azobis(2-methyl-N-phenylpropionamidine) dihydrochloride, 2,2‘-azobis[N-(4-chlorophenyl)-2-methylpropionamidine] dihydrochloride, 2,2‘-azobis[N-(4-hydroxyphenyl)-2-methyl-propionamidine] dihydrochloride, 2,2‘-azobis[N-(4-amino-phenyl)-2-methylpropionamidine] tetrahydrochloride, 2,2‘-azobis[2-methyl-N(phenylmethyl)propionamidine] dihydrochloride, 2,2-azobis[2-methyl-N-2-propenylpropionamidine] dihydrochloride, 2,2-azobis[N-(2-hydroxy-ethyl)2-methylpropionamidine], 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-diazepin-2-yl)propane], 2,2'-azobis[2-(3,4,5,6-tetrahydropyrimidin-2-yl)propane] dihydrochloride, 2,2-azobis[2-(5-hydroxy-3,4,5,6-tetrahydropyrimidin-2-yl)propane], dihydrochloride 2,2‘-azobis{2-[1-(2-hydroxyethyl)-2-imidazolin-2-yl]propane}, combinations thereof, and the like.

[0049] Initiators may be added in suitable amounts, such as from about 0.1 to about 8 weight percent, and in embodiments, from about 0.2 to about 5 weight percent of the monomers.

Chain transfer agents

[0050] In embodiments, chain transfer agents may also be used in forming the latex. Suitable chain transfer agents include dodecanethiol, octanethiol, carbon tetrabromide, combinations thereof, and the like, in amounts from about 0.1 to about 10 percent, and in embodiments, from about 0.2 to about 5 percent by weight of monomers, to control the molecular weight properties of the polymer when emulsion polymerization is conducted in accordance with the present disclosure. Stabilizers

[0051] In embodiments, it may be advantageous to include a stabilizer when forming the latex particles. Suitable stabilizers include monomers that have carboxylic acid functionality. Such stabilizers may be of the following Formula (I): wherein R1 is hydrogen or a methyl group; R2 and R3 are independently selected from alkyl groups containing from about 1 to about 12 carbon atoms or a phenyl group; n is from about 0 to about 20, in embodiments, from about 1 to about 10. Examples of such stabilizers include beta carboxyethyl acrylate (β-CEA), poly(2-carboxyethyl)acrylate, 2-carboxyethyl methacrylate, combinations thereof, and the like. Other stabilizers that may be used include, for example, acrylic acid and its derivatives.

[0052] In embodiments, the carboxylic acid functional stabilizer may also contain a small amount of metal ions, such as sodium, potassium, and/or calcium, to achieve better emulsion polymerization results. The metal ions may be present in an amount from about 0.001 to about 10 weight percent of the carboxylic acid functional stabilizer, in embodiments, from about 0.5 to about 5 weight percent of the carboxylic acid functional stabilizer.

[0053] When present, the stabilizer may be added in amounts from about 0.01 to about 5 percent by weight of the toner, in embodiments, from about 0.05 to about 2 percent by weight of the toner.

[0054] Additional stabilizers that may be used in toner formulation processes include bases such as metal hydroxides, which include sodium hydroxide, potassium hydroxide, ammonium hydroxide, and optionally combinations thereof. Sodium carbonate, sodium bicarbonate, calcium carbonate, potassium carbonate, ammonium carbonate, combinations thereof, and the like are also useful as a stabilizer. In embodiments, a stabilizer may include a composition containing sodium silicate dissolved in sodium hydroxide.

[0055] In the emulsion polymerization process, reactants can be added to a suitable reactor, such as a mixing vessel. The appropriate amount of at least two monomers, in embodiments, from about two to about ten monomers, stabilizer, surfactant(s) initiator, if any, chain transfer agent, if any, and wax, if any, and the like can be combined in the reactor and the emulsion aggregation process can be allowed to begin. Suitable waxes are described in greater detail below as a component to be added in the formation of a toner particle; such waxes can also be useful, in embodiments, in the formation of a latex. Reaction conditions selected to effect the emulsion polymerization process include temperatures, for example, from about 45°C to about 120°C, in embodiments, from about 60°C to about 90°C.

[0056] Nanometer-sized particles can be formed, from about 50 nm to about 800 nm in volume mean diameter, in embodiments, from about 100 nm to about 400 nm in volume mean diameter, as determined, for example, by a Microtrac/Nanotrac particle analyzer.

[0057] After formation of the latex particles, the latex particles can be used to form a toner. In embodiments, the toners can be an emulsion aggregation type toner that is prepared by aggregating and fusing the latex particles of the present disclosure with a colorant, and one or more additives such as surfactants, coagulants, waxes, surface additives, and optionally combinations thereof.

Colorants

[0058] The colorant dispersion can include, for example, submicron colorant particles that have a size, for example, from about 50 to about 500 nanometers in volume average diameter, and in embodiments, from about 100 to about 400 nanometers in volume average diameter. The colorant particles can be suspended in an aqueous phase of water that contains an anionic surfactant, a nonionic surfactant, or combinations thereof. In embodiments, the surfactant can be ionic and can be from about 1 to about 25 weight percent, and in embodiments, from about 4 to about 15 weight percent of the colorant.

[0059] Colorants useful in forming toners in accordance with the present disclosure include pigments, dyes, pigment-dye mixtures, pigment mixtures, dye mixtures, and the like. The colorant can be, for example, carbon black, cyan, yellow, magenta, red, orange, brown, green, blue, violet, or combinations thereof. In embodiments, a pigment can be used. As used herein, a pigment includes a material that alters the color of the light it reflects as a result of selective color absorption. In embodiments, in contrast to a colorant that can generally be applied in an aqueous solution, a pigment is generally insoluble. For example, while a colorant can be soluble in the loading vehicle (the binder), a pigment can be insoluble in the loading vehicle.

[0060] In embodiments where the colorant is a pigment, the pigment can be, for example, carbon black, phthalocyanine, quinacridone, red, green, orange, brown, violet, yellow, fluorescent colorants including the RHODAMINE B™ type, and the like.

[0061] The colorant may be present in the developer toner in an amount of from about 1 to about 25 weight percent of the toner, in embodiments in an amount of from about 2 to about 15 weight percent of the toner.

[0062] Exemplary colorants include carbon black such as REGAL 330® magnetites; Mobay magnetites including MO8029™, MO8060™; Columbian magnetites; MAPICO BLACKS™ and surface treated magnetites; Pfizer magnetites including CB4799™, CB5300™, CB5600™, MCX6369™; Bayer magnetites including BAYFERROX 8600™, 8610™; Northern Pigments magnetites including NP-604™, NP-608™; Magnox magnetites including TMB-100™ or TMB-104™, HELIOGEN BLUE L6900™, D6840™, D7080™, D7020™, PYLAM OIL BLUE™, PYLAM OIL YELLOW™, PIGMENT BLUE 1™ available from Paul Uhlich and Company, Inc.; PIGMENT VIOLET 1™, PIGMENT RED 48™, LEMON CHROME YELLOW DCC 1026™, E.D. TOLUIDINE RED™ and BON RED C™ available from Dominion Color Corporation, Ltd., Toronto, Ontario; NOVAPERM YELLOW FGL™, HOSTAPERM PINK E™ from Hoechst; and CINQUASIA MAGENTA™ available from E.I. DuPont de Nemours and Company. Other colorants include anthraquinone dye and 2,9-dimethyl substituted quinacridone identified in the Color Index as Cl 60710, Cl Disperse Red 15, a diazo dye identified in the Color Index as Cl 26050, Cl Solvent Red 19, copper tetra(octadecylsulfonamido)phthalocyanine, an x-copper phthalocyanine pigment listed in the Color Index as Cl 74160, Cl Pigment Blue, Anthrarene Blue identified in the Color Index as Cl 69810, Special Blue X-2137, 3,3-dichlorobenzidene acetoacetanilides of diarylide yellow, a monoazo pigment identified in the Color Index as Cl 12700, Cl Solvent Yellow 16, a nitrophenylamine sulfonamide identified in the Color Index as Phoron Yellow SE/GLN, Disperse Yellow Cl 33, phenyl-azo-4'-chloro-2,5-dimethoxy-2,5-dimethoxy-4-sulfonanilide acetoacetanilide, Yellow 180, and Permanent Yellow FGL. Organic soluble dyes that have a high purity for the purpose of the range of colors that can be used include Neopen Yellow 075, Neopen Yellow 159, Neopen Orange 252, Neopen Red 336, Neopen Red 335, Neopen Red 366, Neopen Blue 808, Neopen Black X53, Neopen Black X55, the dyes being selected in various suitable amounts, for example, from about 0.5 to about 20 weight percent, in embodiments, from about 5 to about 18 weight percent of the toner.

[0063] In embodiments, examples of colorant include Pigment Blue 15:3 having a Color Index Constitution Number of 74160, Pigment Red Magenta 81:3 having a Color Index Constitution Number of 45160:3, Yellow 17 having a Color Index Constitution Number of 21105, and known colorants such as food coloring, yellow, blue, green, red, magenta dyes, and the like.

[0064] In other embodiments, a magenta pigment, Pigment Red 122 (2,9-dimethylquinacridone), Pigment Red 185, Pigment Red 192, Pigment Red 202, Pigment Red 206, Pigment Red 235, Pigment Red 269, combinations thereof, and the like, may be used as the colorant. Pigment Red 122 (sometimes referred to herein as PR-122) has been widely used in the pigmentation of toners, plastics, paints, and coatings due to its unique magenta shade.

Coagulants

[0065] In embodiments, a coagulant may be added during or prior to aggregation of the latex and the aqueous colorant dispersion. The coagulant may be added over a period of time from about 1 minute to about 60 minutes, in embodiments, from about 1.25 minutes to about 20 minutes, depending on processing conditions.

[0066] Examples of suitable coagulants include polyaluminum halides, such as polyaluminum chloride (CPA), or the corresponding bromide, fluoride, or iodide, polyaluminum silicates, such as polyaluminum sulfosilicate (SSP), and water-soluble metal salts that include aluminum chloride, aluminum nitrite, aluminum sulfate, potassium aluminum sulfate, calcium acetate, calcium chloride, calcium nitrite, calcium oxylate, calcium sulfate, magnesium acetate, magnesium nitrate, magnesium sulfate, zinc acetate, zinc nitrate, zinc sulfate, combinations thereof, and the like. A suitable coagulant is CPA, which is commercially available and can be prepared by controlled hydrolysis of aluminum chloride with sodium hydroxide. Generally, CPA can be prepared by adding two moles of a base to one mole of aluminum chloride. The species is soluble and stable when dissolved and stored under acidic conditions if the pH is less than about 5. The species in solution is believed to contain the formula Al13O4(OH)24(H2O)12 with about 7 positive electrical charges per unit.

[0067] In embodiments, suitable coagulants include a polymetallic salt, such as polyaluminum chloride (PAC), polyaluminum bromide, or polyaluminum sulfosilicate. The polymetallic salt may be in a nitric acid solution, or other dilute acid solutions, such as sulfuric acid, hydrochloric acid, citric acid, or acetic acid. The coagulant may be added in amounts from about 0.01 to about 5 weight percent of the toner, and in embodiments, from about 0.1 to about 3 weight percent of the toner.

Wax

[0068] Wax dispersions may also be added during the formation of a latex or toner in an emulsion aggregation synthesis. Suitable waxes include, for example, submicron wax particles in the size range of about 50 to about 1,000 nanometers, in embodiments, from about 100 to about 500 nanometers in volume average diameter, suspended in an aqueous phase of water and an ionic surfactant, nonionic surfactant, or combinations thereof. Suitable surfactants include those described above. The ionic surfactant or nonionic surfactant may be present in an amount of about 0.1 to about 20 weight percent, and in embodiments, from about 0.5 to about 15 weight percent of the wax.

[0069] The wax dispersion according to embodiments of the present disclosure may include, for example, a natural plant-derived wax, natural animal wax, mineral wax, and/or synthetic wax. Examples of natural plant-derived waxes include, for example, carnauba wax, candelilla wax, Japanese wax, and laurel berry wax. Examples of natural animal-derived waxes include, for example, beeswax, punic wax, lanolin, lacquer wax, shellac wax, and spermaceti wax. Mineral-derived waxes include, for example, paraffin wax, microcrystalline wax, montan wax, ozokerite wax, ceresin wax, petrolatum wax, and petroleum wax. Synthetic waxes of the present disclosure include, for example, Fischer-Tropsch wax, acrylate wax, fatty acid amide wax, silicone wax, polytetrafluoroethylene wax, polyethylene wax, polypropylene wax, and combinations thereof.

[0070] Examples of polypropylene and polyethylene waxes include those commercially available from Allied Chemical and Baker Petrolite, wax emulsions available from Michelman Inc. and Daniels Products Company, EPOLENE N-15 commercially available from Eastman Chemical Products, Inc., VISCOL 550-P, a low weight-average molecular weight polypropylene available from Sanyo Kasel K.K., and similar materials. In embodiments, commercially available polyethylene waxes have a molecular weight (Mw) of about 100 to about 5,000, and in embodiments, from about 250 to about 2,500, while commercially available polypropylene waxes have a molecular weight of about 200 to about 10,000, and in embodiments, from about 400 to about 5,000.

[0071] In embodiments, waxes can be functionalized. Examples of groups added to functionalize waxes include amines, amides, imides, esters, quaternary amines, and/or carboxylic acids. In embodiments, functionalized waxes can be acrylic polymer emulsions, e.g., JONCRYL 74, 89, 130, 537, and 538, all available from Johnson Diversey, Inc, or chlorinated polypropylenes and polyethylenes commercially available from Allied Chemical, Baker Petrolite Corporation, and Johnson Diversey, Inc.

[0072] The wax may be present in an amount from about 0.1 to about 30 weight percent, and in embodiments, from about 2 to about 20 weight percent of the toner.

[0073] In embodiments, a wax with suitable melting properties can be a polymethylene wax, a polyethylene wax, or a Fischer-Tropsch wax. In embodiments, combinations of any of the aforementioned waxes can be employed. A wax can be included in the core and/or shell particles of the toner. The wax can include any of various waxes conventionally used in emulsion aggregation toner compositions. Suitable examples of waxes include polyethylene, polymethylene, polypropylene, polyethylene/amide, polyethylenetetrafluoroethylene, and polyethylenetetrafluoroethylene/amide. Other examples include, for example, polyolefin waxes, such as polyethylene waxes, which include linear polyethylene waxes and branched polyethylene waxes, and polypropylene waxes, which include linear polypropylene waxes and branched polypropylene waxes; paraffin waxes; Fischer-Tropsch waxes; amine waxes; silicone waxes; Mercapto waxes; polyester waxes; urethane waxes; modified polyolefin waxes (e.g., a carboxylic acid-terminated polyethylene wax or a carboxylic acid-terminated polypropylene wax); amide waxes, such as aliphatic polar amide-functionalized waxes; aliphatic waxes consisting of hydroxylated unsaturated fatty acid esters; high-acid waxes, such as high-acid montan waxes; microcrystalline waxes, such as waxes derived from crude oil distillation; and the like. "High-acid waxes" means a wax material that has a high acid content. Waxes may be crystalline or non-crystalline, as desired. "Crystalline polymeric waxes" means a wax material containing an ordered configuration of polymer chains within a polymer matrix that can be characterized by a crystalline melting point transition temperature, Tm. The crystal melting temperature is the melting temperature of the crystalline domains of a polymer sample. This is in contrast to the glass transition temperature, Tg, which characterizes the temperature at which polymer chains begin to flow into the amorphous regions within a polymer. Tg and Tm are typically measured using differential scanning calorimetry (DSC).

[0074] To incorporate the wax into the toner, it is desirable that the wax be in the form of one or more aqueous emulsions or dispersions of solid wax in water, wherein the particle size of the solid wax is typically in the range of about 100 to about 500 nm.

[0075] The toner compositions may contain the wax in any amount from, for example, about 3 to about 15% by weight of the toner, on a dry basis. For example, the toners may contain from about 5 to about 11% by weight of the wax.

pH adjusting agent

[0076] In some embodiments, a pH adjusting agent may be added to control the rate of the emulsion aggregation process. The pH adjusting agent used in the processes of the present disclosure may be any acid or base that does not negatively affect the products that are produced. Suitable bases may include metal hydroxides such as sodium hydroxide, potassium hydroxide, ammonium hydroxide, and optionally combinations thereof. Suitable acids include nitric acid, sulfuric acid, hydrochloric acid, citric acid, acetic acid, and optionally combinations thereof.

Aggregation agents

[0077] Any aggregating agent that has the ability to cause complexation can be used in the formation of toner of the present disclosure. Transition metal or alkaline earth metal salts can be used as aggregating agents. In embodiments, alkali (II) salts can be selected to aggregate sodium sulfonated polyester colloids with a colorant to allow the formation of a toner composite. Such salts include, for example, beryllium chloride, beryllium bromide, beryllium iodide, beryllium acetate, beryllium sulfate, magnesium chloride, magnesium bromide, magnesium iodide, magnesium acetate, magnesium sulfate, calcium chloride, calcium bromide, calcium iodide, calcium acetate, calcium sulfate, strontium chloride, strontium bromide, strontium iodide, strontium acetate, strontium sulfate, barium chloride, barium bromide, barium iodide, and, optionally, combinations thereof. Examples of transition metal anions or salts that can be used as a binding agent include acetates of vanadium, niobium, tantalium, chromium, molybdenum, tungsten, manganese, iron, ruthenium, cobalt, nickel, copper, zinc, cadmium, or silver; acetoacetates of vanadium, niobium, tantalium, chromium, molybdenum, tungsten, manganese, iron, ruthenium, cobalt, nickel, copper, zinc, cadmium, or silver; sulfates of vanadium, niobium, tantalium, chromium, molybdenum, tungsten, manganese, iron, ruthenium, cobalt, nickel, copper, zinc, cadmium, or silver; and aluminum salts, such as aluminum acetate, aluminum halides, such as polyaluminum chloride, combinations thereof, and the like.

[0078] The resulting blend of latex, optionally in a dispersion, colorant dispersion, optional wax, optional coagulant, and optional aggregating agent, may then be stirred and heated to a temperature below the Tg of the latex, in embodiments, from about 30°C to about 70°C, in embodiments from about 40°C to about 65°C, for a period of time from about 0.2 hours to about 6 hours, in embodiments, from about 0.3 hours to about 5 hours, which results in toner aggregates of about 3 microns to about 15 microns in volume mean diameter, in embodiments from about 4 microns to about 8 microns in volume mean diameter.

[0079] In embodiments, a shell can be formed on the aggregate particles. Any latex used noted above to form the latex resin can be used to form the shell latex. In embodiments, a styrene-n-butyl acrylate copolymer can be used to form the shell latex. In embodiments, the latex used to form the shell can have a glass transition temperature of about 35°C to about 75°C, in embodiments, from about 40°C to about 70°C.

[0080] When present, a shell latex may be applied by any method within the competence of those skilled in the art, including dipping, spraying, and the like. The shell latex may be applied until the desired final toner particle size is obtained, in embodiments, from about 3 microns to about 12 microns, in other embodiments from about 4 microns to about 8 microns.

[0081] Once the desired final size of toner particles is obtained, the pH of the mixture can be adjusted with a base to a value of about 3.5 to about 7, and in embodiments, from about 4 to about 6.5. The base can include any suitable base, such as alkali metal hydroxides, such as sodium hydroxide, potassium hydroxide, and ammonium hydroxide. The alkali metal hydroxide can be added in amounts of from about 0.1 to about 30 weight percent of the mixture, in embodiments, from about 0.5 to about 15 weight percent of the mixture.

[0082] The mixture of latex, colorant, and optional wax is subsequently coalesced. Coalescence may include stirring and heating to a temperature of about 80°C to about 99°C, in embodiments, from about 85°C to about 98°C, for a period of about 0.5 hours to about 12 hours, and in embodiments, from about 1 hour to about 6 hours.

[0083] The pH of the mixture can then be lowered to about 3.5 to about 6, in embodiments, from about 3.7 to about 5.5, for example, with an acid to coalesce the toner aggregates. Suitable acids include, for example, nitric acid, sulfuric acid, hydrochloric acid, citric acid, or acetic acid. The amount of acid added can be from about 0.1 to about 30 weight percent of the mixture, and in embodiments, from about 1 to about 20 weight percent of the mixture.

[0084] The mixture is cooled in a cooling or freeze-drying step. Cooling can be to a temperature of about 20°C to about 40°C, in embodiments, from about 22°C to about 30°C for a period of time of about 1 hour to about 8 hours, and in embodiments, from about 1.5 hours to about 5 hours.

[0085] In embodiments, cooling a coalesced aqueous toner slurry includes quenching it by adding a cooling medium, such as ice, dry ice, and the like, to effect rapid cooling to a temperature of from about 20°C to about 40°C, and in embodiments, from about 22°C to about 30°C.

[0086] After such cooling, the aggregate suspension may be heated to a temperature equal to or greater than the Tg of the latex. When the particles have a shell and core configuration, the heating may be above the Tg of the first latex used to form the core and the Tg of the second latex used to form the shell, so as to fuse the shell latex with the core latex. In embodiments, the aggregate suspension may be heated to a temperature of about 80°C to about 90°C, in embodiments, from about 83°C to about 86°C, for a period of time of about 1 hour to about 6 hours, in embodiments, from about 2 hours to about 4 hours.

[0087] The aqueous toner slurry may then be washed. Washing may be conducted at a pH of about 7 to about 12, and in embodiments, at a pH of about 9 to about 11. Washing may occur at a temperature of about 30°C to about 70°C, and in embodiments, from about 40°C to about 67°C. Washing may include filtering and slurrying a filter cake that includes toner particles in deionized water. The filter cake may be washed one or more times by deionized water, or washed by a single wash of deionized water to a pH of about 4, wherein the pH of the aqueous slurry is adjusted with an acid, and optionally followed by one or more washes with deionized water.

[0088] Drying may be performed at a temperature of about 35°C to about 75°C, and in embodiments from about 45°C to about 60°C. Drying may be continued until the wettability level of the particles is below a defined target of about 1 wt%, in embodiments, of less than about 0.7 wt%. Charge control agents

[0089] In embodiments, the toner composition surface additives may comprise charge control agents, as desired. For example, the toner may include positive or negative charge control agents in any desired or effective amount, in one embodiment, in an amount of at least about 0.1 weight percent of the toner, and in another embodiment, at least about 1 weight percent of the toner, and in one embodiment, not more than about 10 weight percent of the toner, and in another embodiment, not more than about 3 weight percent of the toner. Examples of suitable charge control agents include, but are not limited to, quaternary ammonium compounds inclusive of alkylpyridinium halides; bisulfates; alkylpyridinium compounds, which include those disclosed in U.S. Patent No. 4,298,672, the disclosure of which is fully incorporated herein by reference; organic sulfate and sulfonate compositions, including those disclosed in U.S. Patent No. 4,338,390, the disclosure of which is fully incorporated herein by reference; cetylpyridinium tetrafluoroborates; distearyldimethylammonium methyl sulfate; aluminum salts such as BONTRON E84™ or E88™ (Hodogaya Chemical); and the like, as well as mixtures thereof. Such charge control agents may be applied simultaneously with the casing resin described above or after application of the casing resin. Other surface additives

[0090] Additional optional additives that may be combined with a toner include any additive to enhance the properties of toner compositions. Included are surface additives, color enhancers, etc. Surface additives that may be added to toner compositions after washing or drying include, for example, metal salts, metal salts of fatty acids, colloidal silicas, metal oxides, strontium titanates, combinations thereof, and the like. These additives are each typically present in an amount of from about 0.1 to about 10 percent by weight of the toner, in embodiments, from about 0.5 to about 7 percent by weight of the toner. Other additives include zinc stearate and AEROSIL R972® available from Degussa. The coated silicas of U.S. Patent No. 6,190,815 and U.S. Patent No. 6,004,714 may also be selected in amounts of, for example, about 0.05 to about 5 weight percent of the toner, in embodiments, from about 0.1 to about 2 weight percent of the toner. These additives may be added during aggregation or blended into the formed toner product.

[0091] Toner particles produced using a latex of the present disclosure can have a size of about 1 micron to about 20 microns, in embodiments about 2 microns to about 15 microns, in embodiments about 3 microns to about 7 microns. Toner particles of the present disclosure can have a roundness of about 0.9 to about 0.99, in embodiments from about 0.92 to about 0.98.

Marker surface additive

[0092] In embodiments, the marker surface additive comprises a ceramic material comprising various metal oxides. In embodiments, the ceramic material comprises silica, yttrium oxide, lithium oxide, ytterbium oxide, and cerium oxide. An exemplary ceramic material is available from Stardust Materials LLC (Vancouver, WA) as an IR luminescent pigment. Another exemplary non-limiting marker material is emissive infrared nanopowder/nanoparticles made from a combination of oxides, such as Al2O3, MgO, ZnO, ZrO2, SiO2, etc., available from US Research Nanomaterials, Inc. (Houston, TX, USA).

Uses

[0093] The toner in accordance with the present disclosure can be used in a variety of devices including printers, photocopiers, and the like. The toners generated in accordance with the present disclosure are excellent for imaging processes, especially xerographic processes, and are capable of providing high-quality color images with excellent image resolution, acceptable signal-to-noise ratio, and image uniformity. Furthermore, toners of the present disclosure can be selected for electrophotographic imaging and printing processes, such as digital imaging systems and processes.

[0094] Developer compositions may be prepared by mixing the toners obtained through the processes disclosed herein with known carrier particles, which include coated carriers such as steel, ferrites, and the like. The carriers may be present from about 1 weight percent of the toner to about 10 weight percent of the toner, in embodiments, from about 4 weight percent to about 6 weight percent of the toner. The carrier particles may also include a core with a polymeric coating thereon, such as polymethyl methacrylate (PMMA), that has dispersed therein a conductive component such as conductive carbon black. Carrier coatings include silicone resins such as methyl silsesquioxanes, fluoropolymers such as polyvinylidiene fluoride, mixtures of resins that are not very close in the triboelectric series such as polyvinylidiene fluoride and acrylics, thermosetting resins such as acrylics, combinations thereof, and other known components.

[0095] Development may occur through discharge area development. In discharge area development, the photoreceptor is charged and then the areas to be developed are discharged. The development fields and toner charges are such that the toner is repelled by the charged areas on the photoreceptor and attracted to the discharged areas. This development process is used in laser scanners.

[0096] Development can be achieved through the magnetic brush development process disclosed in U.S. Patent No. 2,874,063. This method involves loading a developer material containing toner of the present disclosure and magnetic carrier particles with a magnet. The magnetic field of the magnet causes the magnetic carriers to align in a brush-like configuration, and this "magnetic brush" is placed in contact with the electrostatic imaging surface of the photoreceptor. The toner particles are drawn from the brush to the electrostatic image through electrostatic attraction to the discharged areas of the photoreceptor, and development of the image results. In embodiments, the conductive magnetic brush process is used, in which the developer includes conductive carrier particles and is capable of conducting an electric current from the polarized magnet through the carrier particles to the photoreceptor.

Imaging

[0097] The toner compositions disclosed in the present invention can be used in conjunction with an electrophotographic imaging member as a photoreceptor in various imaging systems, such as those conventionally known as xerographic imaging devices or electrophotographic imaging devices. Such imaging members can be selected for visible, near-red, and/or infrared light imaging and printing systems. The imaging members can be negatively or positively charged, exposed to light having a wavelength of about 700 to about 900 nanometers, as generated by solid-state lasers, for example, arsenide-type lasers, either sequentially or simultaneously, followed by the development of the resulting image and transfer thereof to a printing substrate, such as transparency or paper. Additionally, the imaging members can be selected for visible light imaging and printing systems. The imaging members may be negatively or positively charged, exposed to light having a wavelength of about 400 to about 700 nanometers, followed by development with a known toner, and then transfer and fixation of the image onto a printing substrate.

[0098] In general, the imaging member may first be charged with a corona charging device, such as a corotron charging device, dicorotron, scorotron, pin, prone charging roller (CPR), or the like. Then, an electrostatic image is generated on the imaging member with an electrostatic imaging device. Subsequently, the electrostatic image is developed by known developing devices in one or more developing stations that apply developing compositions, for example, compositions comprised of resin particles, pigment particles, additives including charge control agents and carrier particles, etc. The developed electrostatic image is then transferred to a suitable printing substrate such as paper or transparency in an image transfer station, and affixed to the substrate. Image development may be achieved by various methods, such as hybrid clean-out development, magnetic brush, and the like.

[0099] Transfer of the developed image to a printing substrate may occur by any suitable method, including those in which a corotron or a prone roller is selected. The fixing step may be performed by any suitable method, such as flash fusing, thermal fusing, pressure fusing, steam fusing, and the like.

[0100] After transferring the developed image from the imaging member surface, the imaging member may be cleaned of any residual developer remaining on the surface, and also cleaned of any residual electrostatic charge before being subjected to charging for developing a next or additional image.

Examples

[0101] The following Examples are submitted to illustrate embodiments of the present disclosure. These Examples are intended to be illustrative only and are not intended to limit the scope of the present disclosure. Furthermore, parts and percentages are by weight unless otherwise indicated. As used herein, "room temperature" refers to a temperature of about 20°C to about 25°C.

Example 1

[0102] This example describes the preparation and characterization of marker-comprising toners in accordance with embodiments described herein.

[0103] A series of toner formulations were prepared, which include clear, yellow, magenta, cyan, and black, as indicated in Table 1. Table 1

[0104] Each toner color was blended with a small amount of a ceramic infrared marker (IR luminescent pigment available from Stardust Materials LLC, Vancouver, WA) comprising silica (34%), yttrium oxide (32%), lithium oxide (16%), ytterbium oxide (12%), and cerium oxide (6%).

Toner additive blending

[0105] 75 grams of toner particles were added to a benchtop blender, followed by addition of 3.5% by weight RY50 silica additive (available from Nippon Aerosil), 1.6% SMT5103 titania additive (available from Tayca Corporation), 0.5% zinc stearate additive (available from Ferro Corporation), 0.1% H2050EP silica additive (available from Wacker Chemie), and 0.1% marker powder (Stardust Materials LLC). The contents were then blended at approximately 15,000 rpm for 2.5 minutes to generate the final blended toner in the present invention.

[0106] Figures 1A to E show the triboelectric charging for the various toners comprising marker together with a control.

[0107] Toner Loading Measurement: Toner loading was collected for toner particles mixed with surface additives and the IV marker. 4.5 grams of toner and 100 grams of Xerox Soken MP-116 carrier were mixed in a 60 ml glass bottle to prepare 4.5 pph of toner in carrier. Samples were conditioned for three days in a low humidity zone (zone J) at 21.1°C and 10% RH, and a separate sample in a high humidity zone (zone A) at approximately 28°C/85% RH. Developers with related toner particles were loaded into a Turbula mixer for 10 minutes, where developers with additive-blended toner were loaded into a Turbula mixer for 60 minutes.

[0108] Toner loading was measured as the mass-to-loading ratio (Q/M), also called tribo, and determined by the total shake loading method, which measures the loading in a faraday cage containing developer after the toner is removed by shaking in a stream of air. The total loading collected in the cage is divided by the mass of toner removed by shaking, and the cage is weighted before and after shaking to generate the Q/M ratio or tribo result.

[0109] Figure 2 shows the color characterization for the various toners indicated. The samples were wetted with surfactant and suspended in water. They were then filtered through a membrane to obtain a uniform deposit. The membranes were then dried and cast for analysis by color spectrophotometer. The amount of filtered sample can be adjusted for any AMT (toner mass area), and sampled serially. Measurement through the X-Rite 939 generates data on the color values L*, a*, b*, C*, and h*, as well as spectral data from 400 to 700 nm.

Claims (17)

1. Toner composition characterized by the fact that it comprises toner particles comprising a resin and a colorant, the toner composition further comprising an infrared luminescent marker disposed on the surface of the toner particles, in which the marker is a ceramic comprising oxides of silicon, yttrium, lithium, ytterbium and cerium. 2. Toner composition according to claim 1, characterized in that the marker is nanoparticulate. 3. The toner composition of claim 1, wherein the marker is present in an amount of about 0.05 parts per hundred to about 5 parts per hundred toner particles. 4. The toner composition of claim 1, wherein the toner color is clear or yellow and the marker is present in a concentration in a range of about 0.05 parts per hundred to about 1 part per hundred toner particles. 5. The toner composition of claim 1, wherein the toner color is magenta and the marker is present at about 0.5 to about 2 parts per hundred toner particles. 6. The toner composition of claim 1, wherein the toner color is cyan and the marker is present at about 1 to about 5 parts per hundred toner particles. 7. The toner composition of claim 1, wherein the toner color is black and the marker is present at about 5 to 10 parts per hundred toner particles. 8. Toner composition according to claim 1, characterized in that the toner particles comprise a polymer of acrylate and styrene, an amorphous polyester, a crystalline polyester, or combinations thereof. 9. Toner composition according to claim 1, characterized in that the toner particles are prepared by a chemical process. 10. Toner particles according to claim 1, characterized in that they are prepared by melt mixing and spraying. 11. A method for producing a toner composition comprising toner particles comprising a resin and a colorant, the composition further comprising an infrared luminescent marker disposed on the surface of the toner particles, the method comprising the steps of: mixing the toner particles with a surface additive package comprising the infrared luminescent marker, wherein the marker is a nanoparticulate ceramic comprising oxides of silicon, yttrium, lithium, ytterbium, and cerium. 12. The method of claim 11, wherein the surface additive package further comprises a charge control agent. 13. The method of claim 11, wherein the marker is present in an amount of from about 0.05 parts per hundred to about 5 parts per hundred toner particles. 14. Article characterized by the fact that it comprises a printed image disposed on the article, the printed image being produced with a toner composition that comprises toner particles that comprise a resin and a colorant, in which the toner composition further comprises an infrared luminescent marker disposed on the surface of the toner particles, in which the printed image allows authentication of the article by infrared detection of the infrared luminescent marker, in which the marker is a ceramic that comprises oxides of silicon, yttrium, lithium, ytterbium and cerium. 15. The article of claim 14, characterized in that it is one of an identification badge and a form of currency. 16. Article, according to claim 14, characterized by the fact that the marker is nanoparticulate. 17. The article of claim 14, wherein the marker is present in an amount of from about 0.05 parts per hundred to about 5 parts per hundred toner particles.