FLUORESCENT METALLIC TONER AND RELATED METHODS
By adopting the fluorescent metal toner preparation method with a core-shell structure in metal toner, the problems of low brightness and reflectivity of the existing metal toner are solved, and the effects of high brightness and high reflectivity are achieved, and the suppression of the fluorescence effect is avoided.
Patent Information
- Application Number
- JP2021028003
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2020-03-18
- Filing Date
- 2021-02-24
- Publication Date
- 2025-05-13
- Estimated Expiration
- 2041-02-24
AI Technical Summary
It is difficult for existing metal toners to improve brightness and reflectivity, and the application of fluorescent agents in toners can easily lead to inhibition of fluorescence effects.
Using the preparation method of fluorescent metal toner, a mixture of fluorescent emulsion, aluminum sheet and surfactant is formed, and particles of the desired size are formed by aggregation, and then shell layers are formed on these particles to form a core-shell structure of the fluorescent metal toner.
A fluorescent metal toner with high brightness and high reflectivity is achieved, which avoids the inhibitory effect of the fluorescent agent in the toner and significantly improves the optical performance of the toner.
Smart Images

Figure 0007675529000001 
Figure 0007675529000002 
Figure 0007675529000003
Abstract
Description
[Background technology]
[0001] A conventional electrophotographic printing system for toner applications consists of four stations: cyan, magenta, yellow, and black (CMYK) toner stations. Printing systems have been developed that include the concept of additional electrophotographic stations that allow for color gamut expansion through the addition of other colors, or specialty colors. The machine can always run an additional color in a fifth station in addition to the CMYK toners. Metallic toners have been developed as an additional color that is envisioned. However, it is difficult to improve the brightness and reflectance of existing metallic toners. Summary of the Invention
[0002] The present disclosure provides fluorescent metallic toners, such as fluorescent silver toner and fluorescent gold toner. Methods of making and using such toners are also provided.
[0003] In one aspect, a method for making a fluorescent metallic toner is provided. In some embodiments, such a method includes forming one or more fluorescent latexes including a fluorescent agent, a first type of amorphous resin, and a second type of amorphous resin, where the first type of amorphous resin and the second type of amorphous resin are present in a ratio ranging from 2:3 to 3:2; forming a mixture including the one or more fluorescent latexes, a dispersion including aluminum flakes and a surfactant, and one or more emulsions including a crystalline resin, the first type of amorphous resin, the second type of amorphous resin, and optionally a wax dispersion; agglomerating the mixture to form particles of a predetermined size; forming a shell on the particles of the predetermined size to form core-shell particles; and coalescing the core-shell particles to form a fluorescent metallic toner. Fluorescent metallic toners made using such methods are also provided.
[0004] In another aspect, a fluorescent metallic toner is provided. In some embodiments, the fluorescent metallic toner comprises a core comprising a first type of amorphous polyester resin having a fluorescent agent incorporated therein, a second type of amorphous polyester having a fluorescent agent incorporated therein, encapsulated and homogeneously distributed aluminum flakes, a crystalline polyester resin, an additional amount of the first type of amorphous polyester resin, an additional amount of the second type of amorphous polyester resin, and optionally a wax, and a shell over the core, the shell comprising the first type of amorphous polyester resin and the second type of amorphous polyester resin. Methods of using the fluorescent metallic toner are also provided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0005] The present disclosure provides fluorescent metallic toners, such as fluorescent silver toner and fluorescent gold toner. Methods of making and using such toners are also provided.
[0006] Fluorescent metallic toners include a core that includes aluminum flakes and a fluorescent agent dispersed in one or more polymer resins, and a shell over the core, where the shell also includes one or more polymer resins that may or may not be the same as the resin in the core. Although several fluorescent toners have been developed, it is particularly difficult to incorporate fluorescent agents into a toner without adversely affecting the optical properties of the fluorescent agent. For example, the fluorescence of the fluorescent agent is easily quenched in the toner, resulting in a toner that has little or no fluorescence. The present disclosure prevents such quenching and provides a high brightness L * The present invention is based, at least in part, on the development of an improved toner preparation process that results in a fluorescent metallic toner that has a high reflectivity and is highly reflective.
[0007] Aluminum flakes
[0008] The toner of the present invention comprises aluminum flakes in the core of the toner. The aluminum flakes are generally encapsulated within the toner particles (i.e., core-shell particles) such that there are no aluminum flakes at or on the surface of the particles. In some embodiments, there are no aluminum flakes in or on the shell of the toner. The encapsulation can be confirmed using scanning transmission electron microscopy (SEM / TEM) and X-ray photoelectron spectroscopy (XPS). The aluminum flakes are generally homogeneously distributed throughout the resin matrix of the core of the toner particles. This distribution can also be confirmed using SEM / TEM.
[0009] The aluminum flakes are characterized by an average thickness and an average width (the width taken as the maximum distance across the surface of the flake). In some embodiments, the average thickness is in the range of 1 μm to 10 μm, 6 μm to 10 μm, or 1 μm to 3 μm.
[0010] The amount of aluminum flakes present in the toner of the present invention can vary. In some embodiments, the aluminum flakes are present in an amount ranging from 5% to 30% by weight of the toner, including amounts of 10% to 30% by weight, and 15% to 25% by weight.
[0011] Fluorescent Agent
[0012] The toner of the present invention further comprises a fluorescent agent within the core of the toner. In some embodiments, the fluorescent agent is an ultraviolet (UV) fluorescent agent that absorbs light having wavelengths in the UV portion of the electromagnetic spectrum (10 nm to 400 nm). This includes fluorescent agents that have a maximum absorption in the UV portion of the electromagnetic spectrum. This includes fluorescent agents that have a maximum absorption in the range of 330 nm to 370 nm, 340 nm to 360 nm, or 345 nm to 355 nm. These wavelength ranges may refer to the location of the peak in the fluorescent emission.
[0013] In the fluorescent silver toner, the fluorescer is one that emits fluorescence having a wavelength in the range of 345 nm to 470 nm, 400 to 470 nm, 420 nm to 470 nm, 420 nm to 460 nm, or 345 nm to 450 nm (upon illumination with UV light, which may include sunlight). Exemplary fluorescers for the fluorescent silver toner include 2,5-thiophenediylbis(5-tert-butyl-1,3-benzoxazole), 4,4'-stilbenedicarboxylic acid, 4,4'-bis(5-methyl-2-benzoxazolyl)stilbene, 2-[4-[2-[4-(Benzoxazol-2-yl)phenyl]vinyl]phenyl]-5-methylbenzoxazole. l), 1-(2-cyanostyryl)-4-(4-cyanostyryl)benzene, 4,4-bis(diethylphosphonomethyl)biphenyl, acenaphthylene, 1,2-bis(5-methyl-2-benzoxazole)ethylene; 2,2'-(1,2-ethenediyl)bis[5-methylbenzoxazole], 2,2'-(1,2-ethenediyldi-4,1-phenylene)bisbenzoxazole, 4-bis(1,3-benzoxazole-2 -yl)naphthalene, 2-chlorobenzyl cyanide, oxazole, 2-(chloromethyl)benzonitrile, 2,5-thiophenedicarboxylic acid, 4-tert-butyl-2-nitrophenol, optical brightener 28, optical brightener 220, 2-tert-butyl-1,4-benzoquinone, 2,5-bis(benzoxazol-2-yl)thiophene; 2,2'-(2,5-thiophenediyl)bis-benzoxazole, optical brightener 9, Examples of the fluorescent agents include Fluorescent Whitening Agent VBL, Fluorescent Whitening Agent Pf, Fluorescent Whitening Agent 135, 4,4'-bis[2-(2-sulfophenyl)ethenyl]biphenyl, 4-nitronaphthalene-1,8 dicarboxylic anhydride, Fluorescent Whitening Agent 191, Fluorescent Whitening Agent 204, 2-[2-[4-[2-(3-cyanophenyl)ethenyl]phenyl]ethenyl]-benzonitrile, Fluorescent Whitening Agent 378, 5-Benzoxazolyl, 2-methyl-. Combinations of different fluorescent agents may be used. In some embodiments, the fluorescent agent is Fluorescent Whitening Agent 184, Fluorescent Whitening Agent 185, Fluorescent Whitening Agent 367, or a combination thereof.
[0014] Fluorescent gold toner contains both red and yellow fluorescent agents within the core of the toner. The red fluorescent agent generally emits fluorescence having a wavelength in the range of 600 nm to 630 nm (when illuminated with UV light, which may include sunlight). This wavelength range may refer to the location of the peak in the fluorescent emission. The yellow fluorescent agent generally emits fluorescence having a wavelength in the range of 510 nm to 540 nm (when illuminated with UV light). This wavelength range may refer to the location of the peak in the fluorescent emission.
[0015] Exemplary red fluorescers include Solvent Red 49, Solvent Red 149, Solvent Red 196, Solvent Red 197, and Solvent Red 242. In general, the red fluorescer is not a water-soluble red dye, e.g., Basic Red 1:1 or Basic Red 1. Exemplary yellow fluorescers include Solvent Yellow 160:1, Solvent Yellow 98, Solvent Yellow 172, Solvent Yellow 171, Solvent Yellow 185, Solvent Yellow 145, Solvent Yellow 85, Solvent Yellow 44, Solvent Yellow 195, Solvent Yellow 196, and the like. In general, the yellow fluorescer is not a water-soluble yellow dye, e.g., Basic Yellow 40. Combinations of different types of red fluorescers and combinations of different types of yellow fluorescers may be used.
[0016] Generally, the toner does not include other fluorescent agents, i.e., in some embodiments, the only fluorescent agents in the toner are those selected from above. Generally, the toner does not include pigments (other than the aluminum flakes described above as a colorant), i.e., in some embodiments, no pigments are used in the toner.
[0017] Like aluminum flakes, the fluorescent agent is generally encapsulated within the toner particles (i.e., core-shell particles) such that the fluorescent agent is not present at or on the surface of the particle. In some embodiments, the fluorescent agent is not present in or on the shell of the toner. Similarly, the fluorescent agent is generally homogenously distributed throughout the resin matrix of the core of the toner particles. As mentioned above and as further described below, it is difficult to prevent fluorescence quenching when the fluorescent agent is combined with other components, such as in the toner particles. However, the present disclosure is based at least in part on the development of a toner preparation process that achieves homogenous distribution and encapsulation of the fluorescent agent and addresses the problem of quenching. As further described below, the process involves the use of separate latexes containing the fluorescent agent and two amorphous resins (each of which is a different type of amorphous resin) in the formation of the core of the toner particles.
[0018] In fluorescent silver toner, the fluorescent agent may be present in the toner in an amount of, for example, 0.2% to 2% by weight of the toner, 0.2% to 1.5% by weight of the toner, or 0.2% to 1.0% by weight of the toner. When more than one fluorescent agent is used, these amounts refer to the total amount of fluorescent agent in the toner.
[0019] In a fluorescent gold toner, the red fluorescent agent may be present in the toner in an amount of, for example, 0.5% to 3% by weight of the toner, 0.5% to 2.0% by weight of the toner, or 0.5% to 1.0% by weight of the toner. The yellow fluorescent agent may be present in the toner in an amount of, for example, 0.5% to 3% by weight of the toner, 0.5% to 2.0% by weight of the toner, or 0.5% to 1.0% by weight of the toner. The relative amounts of the red fluorescent agent and the yellow fluorescent agent may provide a red:yellow ratio of 1:10 to 1:2. When more than one red (or yellow) fluorescent agent is used, these amounts refer to the total amount of red (or yellow) fluorescent agent in the toner.
[0020] resin
[0021] The toner of the present invention may include various resins that provide a polymer matrix that contains both the aluminum flakes and the fluorescent agent described above. The toner of the present invention may include two or more different types of resins. The resin may be an amorphous resin, a crystalline resin, or a mixture of crystalline and amorphous resins. The resin may be a polyester resin, such as an amorphous polyester resin, a crystalline polyester resin, or a mixture of crystalline and amorphous polyester resins.
[0022] Crystalline Resin
[0023] The resin may be a crystalline polyester resin formed by reacting a diol with a diacid in the presence of an optional catalyst. Suitable organic diols for forming the crystalline polyester 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, 2,2-dimethylpropane-1,3-diol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, combinations thereof, including their structural isomers. The aliphatic diol can be selected in an amount of, for example, from about 40 to about 60 mole percent of the resin, from about 42 to about 55 mole percent of the resin, from about 45 to about 53 mole percent of the resin, and the second diol can be selected in an amount of from about 0 to about 10 mole percent of the resin, or from about 1 to 4 mole percent of the resin.
[0024] Examples of organic diacids or diesters, such as vinyl diacids or vinyl diesters, selected for the preparation of crystalline resins include oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, fumaric acid, dimethyl fumarate, dimethyl itaconate, cis,1,4-diacetoxy-2-butene, diethyl fumarate, diethyl maleate, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, cyclohexane dicarboxylic acid, malonic acid, and mesaconic acid, diesters or anhydrides thereof. The organic diacid may be selected in an amount of, for example, about 40 to about 60 mole percent of the resin, about 42 to about 52 mole percent of the resin, about 45 to about 50 mole percent of the resin, and the second diacid may be selected in an amount of about 0 to about 10 mole percent of the resin.
[0025] Polycondensation catalysts that may be utilized to form crystalline (as well as amorphous) polyesters include tetraalkyl titanates, dialkyl tin oxides such as dibutyltin oxide, tetraalkyl tins such as dibutyltin dilaurate, and dialkyl tin oxide hydroxides such as butyltin oxide hydroxide, aluminum alkoxides, alkyl zincs, dialkyl zincs, zinc oxides, stannous oxides, or combinations thereof. Such catalysts may be utilized, for example, in amounts of from about 0.01 mole percent to about 5 mole percent based on the starting diacid or diester used to produce the polyester resin.
[0026] Examples of crystalline resins include polyesters, polyamides, polyimides, polyolefins, polyethylene, polybutylene, polyisobutyrate, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, polypropylene, mixtures thereof, and the like. Specific crystalline resins are poly(ethylene adipate), poly(propylene adipate), poly(butylene adipate), poly(pentylene adipate), poly(hexylene adipate), poly(octylene adipate), poly(ethylene succinate), poly(propylene succinate), poly(butylene succinate), poly(pentylene succinate), poly(hexylene succinate), poly(octylene succinate), poly(ethylene sebacate), poly(propylene sebacate), poly(butylene sebacate), poly(pentylene sebacate), poly(hexylene sebacate), poly(octylene sebacate ...ethylene sebacate), poly(propylene sebacate), poly(butylene sebacate), poly(pentylene sebacate), poly(hexylene sebacate), poly(octylene sebacate), poly(ethylene sebacate), poly(ethylene sebacate), poly(ethylene sebacate), poly(propylene sebacate), poly(butylene sebacate), poly(pentylene sebacate), poly(hexylene sebacate), poly(octylene sebacate), poly(ethylene sebacate), poly(ethylene sebacate), poly(ethylene sebacate), poly(ethylene sebacate), poly(propylene se The poly(ethylene-decanoate), poly(ethylene-dodecanoate), poly(nonylene-sebacate), poly(nonylene-decanoate), copoly(ethylene-fumarate)-copoly(ethylene-sebacate), copoly(ethylene-fumarate)-copoly(ethylene-decanoate), copoly(ethylene-fumarate)-copoly(ethylene-dodecanoate), copoly(2,2-dimethylpropane-1,3-diol-decanoate)-copoly(nonylene-decanoate), poly(octylene-adipate), and mixtures thereof. Examples of polyamides include poly(ethylene-adipamide), poly(propylene-adipamide), poly(butylene-adipamide), poly(pentylene-adipamide), poly(hexylene-adipamide), poly(octylene-adipamide), poly(ethylene-succinimide), poly(propylene-sebacamide), and mixtures thereof.Examples of polyimides include poly(ethylene-adipimide), poly(propylene-adipimide), poly(butylene-adipimide), poly(pentylene-adipimide), poly(hexylene-adipimide), poly(octylene-adipimide), poly(ethylene-succinimide), poly(propylene-succinimide), poly(butylene-succinimide), and mixtures thereof.
[0027] In some embodiments, the crystalline polyester has the following formula (I): [ka] where each of a and b can range from 1 to 12, 2 to 12, or 4 to 12, and further, p can range from 10 to 100, 20 to 80, or 30 to 60. In some embodiments, the crystalline polyester resin is poly(1,6-hexylene-1,12-dodecanoate), which can be produced by the reaction of dodecanedioic acid and 1,6-hexanediol.
[0028] As mentioned above, the disclosed crystalline polyester resins can be prepared by a polycondensation process by reacting a suitable organic diol with a suitable organic diacid in the presence of a polycondensation catalyst. A stoichiometric equimolar ratio of organic diol to organic diacid can be used, but when the boiling point of the organic diol is about 180°C to about 230°C, an excess amount of diol, such as about 0.2 to 1 molar equivalent of ethylene glycol or propylene glycol, can be used and removed during the polycondensation process by distillation. The amount of catalyst utilized can vary and can be selected in an amount such as, for example, about 0.01 to about 1 or about 0.1 to about 0.75 mole percent of the crystalline polyester resin.
[0029] The crystalline resin may be present in an amount of, for example, from about 1% to about 85% by weight of the toner, from about 5 to about 50% by weight of the toner, or from about 10% to about 35% by weight of the toner.
[0030] The crystalline resin may have various melting points, such as, for example, about 30° C. to about 120° C., about 50° C. to about 90° C., or about 60° C. to about 80° C. The crystalline resin may have a number average molecular weight (M) of, for example, about 1,000 to about 50,000, about 2,000 to about 25,000, or about 5,000 to about 20,000, as measured by gel permeation chromatography (GPC). n ), and a weight average molecular weight (M) of about 2,000 to about 100,000, about 3,000 to about 80,000, or about 10,000 to about 30,000, as measured by GPC. w The molecular weight distribution of the crystalline resin (M w / M n ) may be, for example, about 2 to about 6, about 3 to about 5, or about 2 to about 4.
[0031] Amorphous Resin
[0032] The resin may be an amorphous polyester resin formed by reacting a diol with a diacid in the presence of an optional catalyst. Examples of diacids or diesters, including vinyl diacids or vinyl diesters, that may be utilized to prepare the amorphous polyester include terephthalic acid, phthalic acid, isophthalic acid, fumaric acid, trimellitic acid, dimethyl fumarate, dimethyl itaconate, cis, 1,4-diacetoxy-2-butene, diethyl fumarate, diethyl maleate, maleic acid, succinic acid, itaconic acid, succinic acid, succinic anhydride, dodecyl succinic acid, dodecyl succinic anhydride, glutaric acid, glutaric anhydride, Included are dicarboxylic acids or diesters such as adipic acid, pimelic acid, suberic acid, azelaic acid, dodecanedioic acid, dimethyl terephthalate, diethyl terephthalate, dimethyl isophthalate, diethyl isophthalate, dimethyl phthalate, phthalic anhydride, diethyl phthalate, dimethyl succinate, dimethyl fumarate, dimethyl maleate, dimethyl glutarate, dimethyl adipate, dimethyl dodecyl succinate, and combinations thereof. The organic dibasic acid or diester may be present in an amount of, for example, about 40 to about 60 mole percent of the resin, about 42 to about 52 mole percent of the resin, or about 45 to about 50 mole percent of the resin.
[0033] Examples of diols that may be used to produce 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, xylylene dimethanol, cyclohexanediol, diethylene glycol, bis(2-hydroxyethyl) oxide, dipropylene glycol, dibutylene, and combinations thereof. The amount of organic diol selected may vary, and the organic diol may be present in an amount of, for example, about 40 to about 60 mole percent of the resin, about 42 to about 55 mole percent of the resin, or about 45 to about 53 mole percent of the resin.
[0034] Examples of suitable amorphous resins include polyesters, polyamides, polyimides, polyolefins, polyethylene, polybutylene, polyisobutyrate, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, polypropylene, and the like, and mixtures thereof.
[0035] Unsaturated amorphous polyester resins may be utilized as the resin. Examples of such resins include those disclosed in U.S. Pat. No. 6,063,827, the disclosure of which is incorporated herein by reference in its entirety. 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(copropoxylated bisphenol co-ethoxylated bisphenol co-fumarate), poly(1,2-propylene fumarate), poly(propoxylated bisphenol co-maleate), poly(ethoxylated bisphenol co-maleate), poly(butyl ... Poly(1,2-propylene itaconate), poly(propoxylated bisphenol co-maleate), poly(ethoxylated bisphenol co-itaconate), poly(butyloxylated bisphenol co-itaconate), poly(copropoxylated bisphenol co-ethoxylated bisphenol co-itaconate), poly(1,2-propylene itaconate), and combinations thereof.
[0036] Suitable polyester resins may be amorphous polyesters such as poly(propoxylated bisphenol A co-fumalate) resins. Examples of such resins and processes for their manufacture include those disclosed in U.S. Patent No. 6,063,827, the disclosure of which is incorporated herein by reference in its entirety.
[0037] Suitable polyester resins include amorphous acid polyester resins.Amorphous acid polyester resins may be any combination of propoxylated bisphenol A, ethoxylated bisphenol A, terephthalic acid, fumaric acid, and dodecenyl succinic anhydride, such as poly(propoxylated bisphenol-co-terephthalate-fumarate-dodecenyl succinate).Another amorphous acid polyester resin that can be used is poly(propoxylate-ethoxylated bisphenol-co-terephthalate-dodecenyl succinic acid-trimellitic anhydride).
[0038] An example of a linear propoxylated bisphenol A fumarate resin that can be utilized as the resin is available under the trade name SPAM II from Resana S / A Industrias Quimicas, Sao Paulo, Brazil. Other commercially available propoxylated bisphenol A fumarate resins that can be utilized include GTUF and FPESL-2 from Kao Corporation, Japan, and EM181635 from Reichhold, Research Triangle Park, NC.
[0039] The amorphous resin or combination of amorphous resins may be present in an amount of, for example, from about 5 to about 95% by weight of the toner, from about 30 to about 90% by weight of the toner, or from about 35 to about 85% by weight of the toner.
[0040] The amorphous resin or combination of amorphous resins may have a glass transition temperature of about 30° C. to about 80° C., about 35° C. to about 70° C., or about 40° C. to about 65° C. The glass transition temperature may be measured using differential scanning calorimetry (DSC). The amorphous resin may have an M of, for example, about 1,000 to about 50,000, about 2,000 to about 25,000, or about 1,000 to about 10,000 when measured by GPC. n When measured by GPC, the Mw may have
[0041] One, two, or more resins may be used in the toner of the present invention. When two or more resins are used, the resins may be in any suitable ratio (e.g., weight ratio), such as, for example, about 1% (first resin) / 99% (second resin) to about 99% (first resin) / 1% (second resin), about 10% (first resin) / 90% (second resin) to about 90% (first resin) / 10% (second resin). When the resin includes a combination of an amorphous resin and a crystalline resin, the resin may be in a weight ratio of, for example, about 1% (crystalline resin) / 99% (amorphous resin) to about 99% (crystalline resin) / 1% (amorphous resin), or about 10% (crystalline resin) / 90% (amorphous resin) to about 90% (crystalline resin) / 10% (amorphous resin). In some embodiments, the weight ratio of the resins is about 80% to about 60% by weight amorphous resin and about 20% to about 40% by weight crystalline resin, in such embodiments, the amorphous resin may be an amorphous resin, for example, a combination of two amorphous resins.
[0042] The resin(s) in the toner may have acid groups present at the resin termini. Possible acid groups include carboxylic acid groups. The number of carboxylic acid groups may be controlled by adjusting the materials and reaction conditions utilized to form the resin. In embodiments, the resin may be a polyester resin having an acid value of about 2 mg KOH / g resin to about 200 mg KOH / g, about 5 mg KOH / g resin to about 50 mg KOH / g resin, or about 5 mg KOH / g resin to about 15 mg KOH / g resin. The acid-containing resin may be dissolved in a tetrahydrofuran solution. The acid value may be detected by titration with a KOH / methanol solution containing phenolphthalein as an indicator. The acid value may then be calculated based on the equivalent amount of KOH / methanol required to neutralize all the acid groups on the resin identified as the titration endpoint.
[0043] wax
[0044] Optionally, waxes may be included in the toner of the present invention. A single wax or a mixture of two or more different waxes may be used. For example, a wax may be added to improve a particular toner property, such as the shape of the toner particles, the presence and amount of wax on the surface of the toner particles, charging and / or fusing properties, gloss, stripping, offset properties, etc. Alternatively, a combination of waxes may be added to provide multiple properties to the toner composition.
[0045] If a wax is included, the wax may be present in an amount of, for example, from about 1% to about 25% by weight of the toner, or from about 5% to about 20% by weight of the toner particles.
[0046] When a wax is used, the wax may include any of the various waxes conventionally used in emulsion aggregation toners. Waxes that may be selected include, for example, waxes having an average molecular weight of about 500 to about 20,000, or about 1,000 to about 10,000. Waxes that may be used include, for example, polyolefins such as polyethylene, including linear and branched polyethylene waxes, polypropylene, including linear and branched polypropylene waxes, polymethylene waxes, polyethylene / amides, polyethylene tetrafluoroethylene, polyethylene tetrafluoroethylene / amides, and polybutene waxes, such as those commercially available from Allied Chemical and Petrolite Corporation, POLYWAX™ polyethylene waxes, such as those commercially available from Baker Petrolite, wax emulsions available from Michaelman, Inc. and Daniels Products Company, EPOLENE N-15™, available from Eastman Chemical Products, Inc., and those commercially available from Sanyo Kasei KKVISCOL 550-P™ low weight average molecular weight polypropylene available from Viscol, Inc.; vegetable waxes such as carnauba wax, rice wax, candelilla wax, sumac wax, and jojoba oil; animal waxes such as beeswax; microcrystalline waxes such as montan wax, ozokerite, ceresin, paraffin wax, and waxes derived from the distillation of crude oils; mineral and petroleum waxes such as silicone waxes, mercapto waxes, polyester waxes, urethane waxes; modified polyolefin waxes (such as carboxylic acid terminated polyethylene waxes or carboxylic acid terminated polypropylene waxes); Fischer-Tropsch waxes; higher fatty acids and higher alcohols such as stearyl stearate and behenyl behenate. ester waxes obtained from higher fatty acids and monohydric or polyhydric lower alcohols, such as butyl stearate, propyl oleate, glyceride monostearate, glyceride distearate, and pentaerythritol tetrabehenate; ester waxes obtained from higher fatty acids and polyhydric alcohol multimers, such as diethylene glycol monostearate, dipropylene glycol distearate, diglyceryl distearate, and triglyceryl tetrastearate; sorbitan higher fatty acid ester waxes, such as sorbitan monostearate; and cholesterol higher fatty acid ester waxes, such as cholesteryl stearate. Examples of functionalized waxes that may be used include, for example, amines, amides, such as AQUA SUPERSLIP 6550™, SUPERSLIP 6530™ available from Micro Powder Inc., fluorinated waxes, such as POLYFLUO 190™, POLYFLUO 200™, POLYSILK 19™, POLYSILK 14™ available from Micro Powder Inc., mixed fluorinated amide waxes such as aliphatic polar amide functionalized waxes; esters of hydroxylated unsaturated fatty acids, such as esters of hydroxylated unsaturated fatty acids, also available from Micro Powder Inc.Examples of suitable waxes include MICROSPERSION 19™ available from Epson Corporation; imide, ester, quaternary amine, carboxylic acid, or acrylic polymer emulsions, such as JONCRYL 74™, 89™, 130™, 537™, and 538™, all available from SC Johnson Wax; and chlorinated polypropylene and polyethylene available from Allied Chemical and Petrolite Corporation and SC Johnson wax. Mixtures and combinations of the foregoing waxes may also be used in embodiments. Waxes may be included, for example, as fuser roll release agents. In embodiments, the wax may be crystalline or amorphous.
[0047] Toner Preparation Process
[0048] To form the toner of the present invention, any of the above resins may be provided as an emulsion, for example, by using a solvent-based phase inversion emulsification process. The emulsion may then be utilized as a raw material to form the toner, for example, by using an emulsion aggregation and coalescence (EA) process. However, the toner may be prepared using other processes.
[0049] To achieve encapsulation and uniform distribution of the aluminum flakes, a separate dispersion containing the aluminum flakes and a surfactant is generally used in the toner preparation process. Exemplary surfactants include anionic surfactants such as diphenyloxide disulfonic acid, ammonium lauryl sulfate, sodium dodecylbenzene sulfate, dodecylbenzene sulfonic acid, sodium alkyl naphthalene sulfonate, sodium dialkyl sulfosuccinate, sodium alkyl diphenyl ether disulfonate, potassium salts of alkyl phosphates, sodium polyoxyethylene lauryl ether sulfate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl ether triethanolamine sulfate, sodium naphthalene sulfate, sodium naphthalene sulfonate formaldehyde condensates, and mixtures thereof, as well as nonionic surfactants such as polyvinyl alcohol, methyl cellulose, ethyl cellulose, propyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, polyoxyethylene cetyl ether, polyoxyethylene lauryl ether, polyoxyethylene octyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene sorbitan monolaurate, polyoxyethylene stearyl ether, dialkylphenoxypoly(ethyleneoxy)ethanol, and mixtures thereof. However, in some embodiments, the surfactant is dodecylbenzenesulfonic acid, and the surfactant is present in the separate dispersion in an amount ranging from 1.5% to 4% by weight, relative to the amount of aluminum flakes. The surfactant and these amounts are useful for achieving encapsulation and homogeneous distribution of the aluminum flakes. When the aluminum flakes are incorporated into the toner particles using this surfactant and these amounts, they can be referred to as "encapsulated and homogeneously distributed" aluminum flakes. As noted above, the encapsulation and homogeneous distribution can be confirmed using SEM / TEM / XPS.
[0050] As mentioned above, in order to achieve similar encapsulation and homogeneous distribution of the fluorescent agent, as well as to prevent fluorescence quenching, a separate latex containing the fluorescent agent (fluorescent latex) is generally used in the preparation process. One separate latex containing the desired fluorescent agent and the desired amorphous resin may be used, or multiple separate latexes may be used (e.g., in a fluorescent gold toner, one separate latex containing a red fluorescent agent and two amorphous resins, and another separate latex containing a yellow fluorescent agent and two amorphous resins, etc.). In any case, the latex used to form the toner provides the fluorescent agent and two amorphous resins (each a different type of amorphous resin), and these latexes provide the two amorphous resins in a weight ratio of 2:3 to 3:2. This includes a weight ratio of 1:1. That is, when two or more latexes are used together, the latexes provide the two amorphous resins within this weight ratio range. These ranges have been found to be important for obtaining encapsulation and homogeneous distribution of the fluorescent agent in the toner particles, as well as for preventing fluorescence quenching. Outside these ranges, the fluorescent properties of the toner decrease, due at least in part to fluorescence quenching. In some embodiments, the amorphous resin is an amorphous polyester resin. In some embodiments, one of the amorphous resins has a larger M than the other. n Or M w has.
[0051] Furthermore, to prevent fluorescence quenching, it is useful to use an amount of fluorescent agent in the fluorescent latex in the range of 1.5% to 8% by weight, relative to the total weight of the fluorescent latex. Outside this range, the fluorescent properties of the toner decrease, due at least in part to fluorescence quenching. When the fluorescent latex contains more than one fluorescent agent, these amounts refer to the total amount of fluorescent agent in the toner.
[0052] The fluorescent / amorphous resin, when incorporated into toner particles using the process and amount of fluorescent agent described immediately above, may be referred to as a "fluorescent-incorporated amorphous resin." The fluorescence and optical properties of the resulting toner are determined using an in-line spectrophotometer (ILS), e.g., an X-Rite ILS, as described in the Examples below, and are measured using a lightness L * and reflectance can be measured.
[0053] When a resin is incorporated into toner particles using an emulsion that does not contain a fluorescent agent, the resin may be referred to as a non-fluorescent agent-incorporated resin, or simply as a "resin", i.e., not modified by the phrase "fluorescent agent-incorporated".
[0054] If a wax is used, the wax may be incorporated into the toner as a separate dispersion of the wax in water.
[0055] In some embodiments, the toner of the present invention is prepared by an EA process, such as by a process that includes agglomerating a mixture of emulsions that include resin, aluminum flake, fluorescent agent, and optionally wax, and then combining the mixture. As described above, the aluminum flake is generally provided to the mixture as a separate dispersion. Similarly, the fluorescent agent is generally provided to the mixture as one or more separate fluorescent latexes, as described above. The resin-containing emulsion may include one or more resins, or different resins may be provided as different emulsions. The resin-containing emulsion generally does not include fluorescent agent, and thus no fluorescent agent is used.
[0056] The mixture may then be homogenized. This may be accomplished by mixing at about 600 to about 6,000 revolutions per minute. Homogenization may be accomplished by any suitable means including, for example, an IKA ULTRA TURRAX T50 probe homogenizer. Once the pH is adjusted to less than 5, a flocculant may be added to the mixture. Any suitable flocculant may be utilized. Suitable flocculants include, for example, aqueous solutions of divalent or multivalent cationic materials. The flocculant may be, for example, an inorganic cationic flocculant such as a polyaluminum halide, such as polyaluminum chloride (PAC), or the corresponding bromide, fluoride, or iodide; a polyaluminum silicate, such as polyaluminum sulfosilicate (PASS); or a water-soluble metal salt, including aluminum chloride, aluminum nitrite, aluminum sulfate, potassium aluminum sulfate, calcium acetate, calcium chloride, calcium nitrite, calcium oxyacid, calcium sulfate, magnesium acetate, magnesium nitrate, magnesium sulfate, zinc acetate, zinc nitrate, zinc sulfate, zinc chloride, zinc bromide, magnesium bromide, copper chloride, and copper sulfate; or a combination thereof. The flocculant may be selected from the group consisting of a polyaluminum halide, polyaluminum chloride ... g The flocculant may be added to the mixture at a temperature below 100° C. The flocculant may be added to the mixture under homogenization.
[0057] The flocculant may be added to the mixture in an amount of, for example, about 0% to about 10% by weight of the total amount of resin, about 0.2% to about 8% by weight of the total amount of resin, or about 0.5% to about 5% by weight of the total amount of resin.
[0058] The particles of the mixture may be aggregated until a predetermined desired particle size is obtained. The predetermined desired size refers to the desired particle size obtained as determined prior to formation, and the particle size is monitored during the growth process until such particle size is reached. Samples may be taken during the growth process and analyzed, for example, with a Coulter Counter, for volume average particle size. Thus, aggregation may proceed by maintaining an elevated temperature or slowly increasing the temperature, for example, to about 30° C. to about 100° C. in some embodiments, about 30° C. to about 80° C. in some embodiments, or about 30° C. to about 50° C. in some embodiments. The temperature may be held for a period of about 0.5 hours to about 6 hours, or in embodiments, about 1 hour to about 5 hours, with stirring, to provide aggregated particles. Once the predetermined desired particle size is reached, a shell may be added. The volume average particle size of the particles prior to application of the shell may be, for example, about 3 μm to about 10 μm, in some embodiments, about 4 μm to about 9 μm, or about 6 μm to about 8 μm.
[0059] Shell Resin
[0060] In embodiments, after aggregation but prior to coalescence, a resin coating may be applied to the aggregated particles to form a shell thereon. Any of the resins described above may be utilized in the shell. In embodiments, an amorphous polyester resin is utilized in the shell. In some embodiments, two amorphous polyester resins are used in the shell. In embodiments, a crystalline polyester resin and two different types of amorphous polyester resins are utilized in the core, and the same two types of amorphous polyester resins are utilized in the shell.
[0061] The shell may be applied to the aggregated particles by using a shell resin in the form of an emulsion(s) as described above. Such an emulsion may be combined with the aggregated particles under conditions sufficient to form a coating on the aggregated particles. For example, formation of the shell over the aggregated particles may occur with heating to a temperature of from about 30° C. to about 80° C., or from about 35° C. to about 70° C. Formation of the shell may occur over a period of from about 5 minutes to about 10 hours, or from about 10 minutes to about 5 hours.
[0062] Once the desired size of the toner particles is achieved, the pH of the mixture may be adjusted with a pH control agent, such as a base, to a value of from about 3 to about 10, or in some embodiments, from about 5 to about 9. The adjustment of the pH may be utilized to freeze to stop toner growth. The base utilized to stop toner growth may include any suitable base, such as, for example, an alkali metal hydroxide, such as sodium hydroxide, potassium hydroxide, ammonium hydroxide, combinations thereof, etc. In embodiments, a chelating agent, such as ethylene diamine tetraacetic acid (EDTA), may be added to assist in adjusting the pH to the desired value above. Other chelating agents may be used.
[0063] In embodiments, the size of the core-shell toner particles (before coalescence) may be from about 3 μm to about 10 μm, from about 4 μm to about 10 μm, or from about 6 μm to about 9 μm.
[0064] Merge
[0065] Following aggregation to the desired particle size and application of the shell, the particles may then be coalesced to the desired final shape, which may be accomplished by heating the mixture to a temperature of, for example, about 45°C to about 150°C, about 55°C to about 99°C, or about 60°C to about 90°C (which may be at or above the glass transition temperature of the resin used to form the toner particles). Heating may be continued, or the pH of the mixture may be adjusted (e.g., reduced) over a period of time to reach the desired circularity. The period may be from about 1 hour to about 5 hours, or from about 2 hours to about 4 hours. Various buffers may be used during coalescence. The total period of coalescence may be from about 1 hour to about 9 hours, from about 1 hour to about 8 hours, or from about 1 hour to about 5 hours. Agitation may be utilized during coalescence, for example, from about 20 rpm to about 1000 rpm, or from about 30 rpm to about 800 rpm.
[0066] After aggregation and / or coalescence, the mixture may be cooled to room temperature. Cooling may be rapid or slow, as desired. A suitable cooling process may include introducing cold water into a jacket around the reactor. After cooling, the toner particles may be sieved through a sieve of the desired size, filtered, washed with water, and then dried. Drying may be accomplished by any suitable drying process, including, for example, freeze drying.
[0067] Other Additives
[0068] In embodiments, the toner of the present invention may also contain other optional additives. For example, the toner may include a positive or negative charge control agent. Surface additives may also be used. Examples of surface additives include metal oxides such as titanium oxide, silicon oxide, aluminum oxide, cerium oxide, tin oxide, mixtures thereof, and the like; colloidal amorphous silica such as AEROSIL®, metal salts and metal salts of fatty acids (such as zinc stearate, calcium stearate, and magnesium stearate), mixtures thereof, and the like; long chain alcohols such as UNILIN 700; and mixtures thereof. These surface additives may be present in an amount of about 0.1% to about 5% by weight of the toner, or about 0.25% to about 3% by weight of the toner.
[0069] Toner Characteristics
[0070] In embodiments, the dry toner particles, excluding external surface additives, exhibit one or more of the following characteristics:
[0071] (1) A volume average particle size of about 5.0 μm to about 12.0 μm, about 6.0 μm to about 12.0 μm, or about 8.0 μm to about 12.0 μm.
[0072] (2) A circularity of about 0.90 to about 1.00, about 0.92 to about 0.99, or about 0.93 to about 0.97.
[0073] These properties may be measured according to the techniques described in the Examples below.
[0074] In embodiments, the dry toner particles, excluding external surface additives, exhibit one or more of the following characteristics:
[0075] (3) Fluorescent silver toner: 0.65 mg / cm 2 A lightness L of at least 66, at least 67, or at least 68, or in the range of 66 to 69, in terms of toner mass per area (TMA) * For fluorescent gold toner, 0.65 mg / cm 2 A lightness L of at least 64, at least 65, or at least 66, or in the range of 64 to 67, in a toner mass per area (TMA) of * .
[0076] (4) Fluorescent silver toner (0.45 mg / cm 2 A reflectance of at least 45 in the range of 430 nm to 440 nm, at least 46 in this wavelength range, at least 47 in this wavelength range, or in the range of 45 to 50 in this wavelength range. 2 A reflectance of at least 30 in the range of 500 nm to 600 nm, at least 35 in this wavelength range, at least 40 in this wavelength range, at least 45 in this wavelength range, or in the range of 30 to 50 in this wavelength range.
[0077] Lightness L * , CIELAB color space (CIE L * a * b * The Lab color space (also known as the Lab color space or sometimes simply abbreviated as the Lab color space) is a color space defined by the International Commission on Illumination (CIE). It is a set of colors ranging from black (0) to white (100). * , a from green (-) to red (+) * , and b from blue (-) to yellow (+) * Color is expressed as three values:
[0078] Since three parameters are measured, the space itself is a three-dimensional real number space allowing for an infinite number of possible colors. In practice, the space is usually mapped onto a three-dimensional integer space for digital representation, thus L * , a * , and b * The values are usually absolute, with a predefined range. * , L * = 0 represents the darkest black, L * =100 represents the brightest white. Color channel a * and b * is a * =0 and b * = 0 represents a true neutral gray value. * The axis represents the green-red component, with the negative direction being green and the positive direction being red. * The axis represents the blue-yellow component, with the negative direction being blue and the positive direction being yellow. * axis and b * Axis scaling and limits depend on the particular implementation, but are often implemented with a range of ±100 or -128 to +127 (signed 8-bit integers).
[0079] Lightness L * Both the Lab value and reflectance can be measured using an ILS, such as an X-Rite ILS operated according to the manufacturer's instructions. The two settings typically used with an X-Rite ILS to measure Lab values are M0 (white light and undefined UV) and M1 (white light and defined UV). M0 is most commonly used to evaluate base colors. M1 is most commonly used to evaluate fluorescence measurements. The M1 setting is used to measure the L of the toners of the present invention described above. * and used to obtain reflectance values.
[0080] These properties may be measured according to the techniques described in the Examples below.
[0081] Developers and Carriers
[0082] The toner of the present invention may be formulated into a developer composition. The developer composition may be prepared by mixing the toner of the present disclosure with known carrier particles, including coated carriers such as steel, ferrite, and the like. Such carriers include those disclosed in U.S. Pat. Nos. 4,937,166 and 4,935,326, the entire disclosures of each of which are incorporated herein by reference. The toner may be present in the carrier in an amount of about 1% to about 15% by weight, about 2% to about 8% by weight, or about 4% to about 6% by weight. The carrier particles may also include a core having a polymer coating, such as polymethylmethacrylate (PMMA), in which a conductive component, such as conductive carbon black, is dispersed. Carrier coatings include silicone resins such as methylsilsesquioxane, fluoropolymers such as polyvinylidene fluoride, mixtures of resins that are not adjacent in the triboelectric series, such as polyvinylidene fluoride and acrylic, thermosetting resins such as acrylic, combinations thereof, and other known components.
[0083] Applicable
[0084] The toner of the present invention may be used in various electrophotographic processes and with various electrophotographic printers. The electrophotographic imaging process includes, for example, preparing an image in an electrophotographic printer that includes a charging component, an imaging component, a photoconductive component, a developing component, a transfer component, and a fusing component. In embodiments, the developing component may include a developer prepared by mixing a carrier with any of the toners described herein. The electrophotographic printer may be a high speed printer, a black and white high speed printer, a color printer, etc. Once the image is formed with the toner / developer, the image may then be transferred to an image receiving medium such as paper. A fuser roll member may be used to fuse the toner to the image receiving medium by using heat and pressure. EXAMPLES
[0085] The following examples are presented to illustrate the embodiments of the present disclosure. These examples are merely illustrative and are not intended to limit the scope of the present disclosure. Also, unless otherwise stated, parts and percentages are by weight. As used throughout this specification, "room temperature" refers to a temperature between 20°C and 25°C.
[0086] Silver Toner Preparation.
[0087] First, the fluorescent latex was prepared as follows. A mixture of 120g of the first type of amorphous polyester resin, 120g of the second type of amorphous polyester resin, and 7.2g of the fluorescent agent was dissolved in a mixture of ethyl acetate, isopropyl alcohol, and aqueous ammonia in a ratio of (145 / 48 / 40g) in a 2L reactor at 60°C. 500g of deionized water containing a surfactant (Calfax DB-45 from Pilot Chemical Company) was added to the mixture to form an emulsion. The reactor was filled with a distillation column to distill off the organic solvent. Finally, the resulting emulsion was filtered through a 25μm sieve. The average particle size of the emulsion was 218nm, and the solid content was about 41wt%. The fluorescent agent content in the emulsion was about 3wt%.
[0088] Next, fluorescent silver toner particles were prepared as follows: A dispersion of aluminum flake pigment (45 g) with anionic surfactant in deionized water was stirred at room temperature for 2 hours. A mixture was formed by combining the fluorescent latex, a first emulsion containing a crystalline polyester resin, a second emulsion containing a first type of amorphous polyester resin, and a third emulsion containing a second type of amorphous polyester resin. This mixture and aluminum sulfate (ALS) solution were added to the aluminum flake dispersion in portions while the reaction temperature was increased from 40° C. to 48° C. After a period of time, an emulsion containing two types of amorphous polyester resins was added to form a shell on the top of the particles. After the aggregation was complete, the particle dispersion was frozen with a chelating agent at a pH of about 8. The mixture was then heated to 84° C. to coalesce. When the circularity reached 0.940, the batch was quenched below 40° C. The resulting silver toner particles were washed with deionized water and freeze-dried into a powder.
[0089] The fluorescent silver toner particles had approximately 20% by weight aluminum flake and 0.6% by weight fluorescent agent. A comparative silver toner was prepared using aluminum flake (20% by weight) but no fluorescent agent.
[0090] Preparation of gold toner.
[0091] First, the fluorescent latex was prepared as follows. The red fluorescent latex was prepared from a mixture of 120 g of a first type of amorphous polyester resin, 120 g of a second type of amorphous polyester resin, and 2 wt% of a red fluorescent agent dissolved in a mixture of ethyl acetate, isopropyl alcohol, and aqueous ammonia in a ratio of (145 / 48 / 40 g) in a 2 L reactor at 60°C. 500 g of deionized water containing a surfactant (Calfax DB-45 from Pilot Chemical Company) was added to the mixture to form an emulsion. The reactor was filled with a distillation column to distill off the organic solvent. Finally, the resulting emulsion was filtered through a 25 μm sieve. The average particle size of the emulsion was 200, and the solid content was about 40 wt%. The red fluorescent agent content in the emulsion was about 2 wt%. The yellow fluorescent latex was prepared similarly, except that about 2 wt% of the yellow fluorescent agent was used. The resulting emulsion had an average particle size of 200 and a solids content of about 40% by weight.
[0092] Next, fluorescent gold toner particles were prepared as follows: A dispersion of aluminum flake pigment (45 g) with anionic surfactant in deionized water was stirred at room temperature for 2 hours. A mixture was formed by combining red fluorescent latex, yellow fluorescent latex, a first emulsion containing a crystalline polyester resin, a second emulsion containing a first type of amorphous polyester resin, and a third emulsion containing a second type of amorphous polyester resin. This mixture and aluminum sulfate (ALS) solution were added in portions to the aluminum flake dispersion while the reaction temperature was increased from 40° C. to 48° C. After a period of time, an emulsion containing two types of amorphous polyester resins was added to form a shell on the top of the particles. After the aggregation was completed, the particle dispersion was frozen with a chelating agent at a pH of about 8. The mixture was then heated to 84° C. to coalesce. When the circularity reached 0.940, the batch was quenched below 40° C. The resulting gold toner particles were washed with deionized water and freeze-dried to a powder.
[0093] The fluorescent gold toner particles had approximately 20% by weight aluminum flake, 0.5% by weight red fluorescent agent, and 2% by weight yellow fluorescent agent. A comparative gold toner was prepared using aluminum flake (20% by weight), but using red and yellow pigments (7% and 0.7% by weight, respectively) instead of the red / yellow fluorescent agents.
[0094] Toner Properties. Toner particle size was analyzed from the dry toner particles, excluding external surface additives, using a Beckman Coulter Multisizer 3 operated according to the manufacturer's instructions. A representative sampling was performed as follows: a small amount (approximately 1 gram) of toner sample was obtained, filtered through a 25 μm sieve, and then placed in an isotonic solution to obtain a concentration of approximately 10%, after which the sample was measured on the Multisizer. Circularity was analyzed from the dry toner particles, excluding external surface additives, using a Sysmex 3000 operated according to the manufacturer's instructions. The D50v size and circularity results are shown in Table 1 below.
[0095] [Table 1] Table 1. Characteristics of toner particles
[0096] The morphology of the toner particles was analyzed from the dried toner particles, excluding the external surface additives, by SEM and TEM (data not shown). Images of the fluorescent silver and fluorescent gold toner particles clearly showed a core-shell structure that completely encapsulated the aluminum flakes (no aluminum flakes are present at or on the surface of the particle or within the shell) and a homogenous aluminum flake distribution.
[0097] The optical properties of the fluorescent silver and gold toners, as well as the comparative non-fluorescent silver and gold toners, were analyzed using an X-Rite ILS operated according to the manufacturer's instructions. For the fluorescent silver toner, 0.45 mg / cm 2 ~0.85mg / cm 2 Toner mass per area (TMA) of 66 to 75 luminosity L *At the same time, a reflectance of 45-50 was obtained at wavelengths of 430-440 nm (TMA was 0.45 mg / cm 2 For fluorescent gold toner, the concentration was 0.45 to 0.85 mg / cm 2 Toner mass per area (TMA) of 65 to 71 luminosity L * At the same time, a reflectance of 30 to 50 was obtained at wavelengths of 430 nm to 440 nm (TMA was 0.45 mg / cm 2 In addition, the reflectance of the fluorescent gold print is higher than the non-fluorescent gold print. More specifically, the reflectance of the fluorescent gold print is approximately 20 units higher at wavelengths between 500 nm and 520 nm, and 20-30 units higher at wavelengths between 550 nm and 600 nm (TMA was 0.45 mg / cm). 2 (It was.)
[0098] Finally, the fluorescent silver and gold toners fluoresced under UV illumination. This fluorescence was measured and used to calculate the amount of fluorescent agent therein. The measured amount of fluorescent agent was compared to the theoretical amount of fluorescent agent (calculated based on the amount used in the toner preparation process described above). The comparison showed that the measured amount was nearly identical to the theoretical amount. Together, these results confirm the encapsulation and homogenous distribution of the fluorescent agent without significant fluorescence quenching.
[0099] It will be understood that variations of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other different systems or applications. Various presently unanticipated or unprecedented alternatives, modifications, variations, or improvements may be subsequently made by those skilled in the art, which are also intended to be encompassed by the following claims. Yet another aspect of the present invention may be as follows. [1] A method for producing a fluorescent metallic toner, the method comprising: forming one or more fluorescent latexes including a fluorescent agent, a first type of amorphous resin, and a second type of amorphous resin, wherein the first type of amorphous resin and the second type of amorphous resin are present in a ratio ranging from 2:3 to 3:2; forming a mixture comprising the one or more fluorescent latexes, a dispersion comprising aluminum flakes and a surfactant, and one or more emulsions comprising a crystalline resin, the first type of amorphous resin, the second type of amorphous resin, and optionally a wax dispersion; agglomerating the mixture to form particles of a predetermined size; forming a shell over the particle of the predetermined size to form a core-shell particle; and coalescing said core-shell particles to form a fluorescent metallic toner. [2] The method according to [1], wherein the first type of amorphous resin and the second type of amorphous resin are present in the one or more fluorescent latexes in a 1:1 ratio. [3] The method according to [1] above, wherein the fluorescent agent is present in the fluorescent latex in an amount ranging from 1.5% by weight to 8% by weight of the one or more fluorescent latexes. [4] The method according to [1], wherein the fluorescent metallic toner is a fluorescent silver toner, and the fluorescent agent is selected from the group consisting of Fluorescent Brightener 184, Fluorescent Brightener 185, Fluorescent Brightener 367, and combinations thereof. [5] The method according to [1], wherein the fluorescent metallic toner is a fluorescent gold toner, and the one or more fluorescent latexes include a red fluorescent agent and a yellow fluorescent agent. [6] The method according to [5], wherein the red fluorescent agent is selected from Solvent Red 49, Solvent Red 149, and combinations thereof, and the yellow fluorescent agent is selected from Solvent Yellow 160:1, Solvent Yellow 172, Solvent Yellow 98, and combinations thereof. [7] The fluorescent metallic toner has a density of 0.65 mg / cm 2 At least 66 L of toner mass per area (TMA) * , 0.45 mg / cm 2 The method according to claim 1, wherein the fluorescent silver toner is characterized by a reflectance of at least 45 in the wavelength range of 430 nm to 440 nm in the TMA of 100 nm, or both. [8] The fluorescent metallic toner has a density of 0.65 mg / cm 2 At least 64 L in the TMA * , 0.45 mg / cm 2 The method according to claim 1, wherein the toner is a fluorescent gold toner characterized by a reflectance of at least 30 in the wavelength range of 500 nm to 600 nm in the TMA of the above, or both. [9] The method according to [1], wherein the crystalline resin, the first type of amorphous resin, and the second type of amorphous resin are polyesters.
[10] The crystalline polyester resin is represented by Formula I:
change
[11] The method according to [9], wherein the crystalline polyester resin is poly(1,6-hexylene-1,12-dodecanoate).
[12] The method according to [9], wherein the first type of amorphous polyester resin is poly(propoxylated bisphenol-co-terephthalate-fumarate-dodecenyl succinate) and the second type of amorphous polyester resin is poly(propoxylated-ethoxylated bisphenol-co-terephthalate-dodecenyl succinate-trimellitic anhydride).
[13] The method of [1], wherein the fluorescent metallic toner is a fluorescent silver toner, the fluorescent agent is selected from Fluorescent Brightener 184, Fluorescent Brightener 185, Fluorescent Brightener 367, and combinations thereof, the crystalline polyester resin is poly(1,6-hexylene-1,12-dodecanoate), the first type of amorphous polyester resin is poly(propoxylated bisphenol-co-terephthalate-fumarate-dodecenyl succinate), and the second type of amorphous polyester resin is poly(propoxylated-ethoxylated bisphenol-co-terephthalate-dodecenyl succinate-trimellitic anhydride).
[14] The method according to [1], wherein the fluorescent metallic toner is a fluorescent gold toner, the one or more fluorescent latexes include a red fluorescent agent selected from Solvent Red 49, Solvent Red 149, and combinations thereof, and a yellow fluorescent agent selected from Solvent Yellow 160:1, Solvent Yellow 172, Solvent Yellow 98, and combinations thereof, the crystalline polyester resin is poly(1,6-hexylene-1,12-dodecanoate), the first type of amorphous polyester resin is poly(propoxylated bisphenol-co-terephthalate-fumarate-dodecenyl succinate), and the second type of amorphous polyester resin is poly(propoxylated-ethoxylated bisphenol-co-terephthalate-dodecenyl succinate-trimellitic anhydride).
[15] The fluorescent silver toner has a density of 0.65 mg / cm 2 At least 66 L in the TMA * , 0.45 mg / cm 2 The method according to claim 13, characterized in that the TMA has a reflectance of at least 45 in the wavelength range of 430 nm to 440 nm, or both.
[16] The fluorescent gold toner has a density of 0.65 mg / cm 2 At least 64 L in the TMA * , 0.45 mg / cm 2 The method according to claim 14, characterized in that the TMA has a reflectance of at least 30 in the wavelength range of 500 nm to 600 nm, or both.
[17] A fluorescent metallic toner, the toner being formed according to the method described in [1] above, comprising a core containing the fluorescent agent, the aluminum flakes, the crystalline resin, the first type of amorphous resin, the second type of amorphous resin, and optionally the wax, the toner further comprising the shell over the core.
[18] A fluorescent metallic toner, a core comprising a first type of amorphous polyester resin having a fluorescent agent incorporated therein, a second type of amorphous polyester having a fluorescent agent incorporated therein, encapsulated and homogeneously distributed aluminum flakes, a crystalline polyester resin, an additional amount of said first type of amorphous polyester resin, an additional amount of said second type of amorphous polyester resin, and optionally a wax; a shell over the core, the shell comprising the first type of amorphous polyester resin and the second type of amorphous polyester resin.
[19] The fluorescent metallic toner has a density of 0.65 mg / cm 2 At least 66 L in the TMA * , 0.45 mg / cm 2 The fluorescent metallic toner according to the above item
[18] is a fluorescent silver toner characterized by a reflectance of at least 45 in a wavelength range of 430 nm to 440 nm in the TMA of the above item, or both.
[20] The fluorescent metallic toner has a density of 0.65 mg / cm 2 At least 64 L of toner mass per area (TMA) * , 0.45 mg / cm 2 The fluorescent metallic toner according to the above item
[18] is a fluorescent gold toner characterized by a reflectance of at least 30 in a wavelength range of 500 nm to 600 nm in the TMA of the above item, or both.
[21] A method for using the fluorescent metallic toner according to
[18] , comprising: forming an image comprising said toner using an electrophotographic printer; transferring the image including the toner to an image receiving medium; fusing the toner to the image receiving medium.
Claims
1. 1. A method for producing a fluorescent metallic toner, the method comprising: forming one or more fluorescent latexes comprising a fluorescent agent, a first type of amorphous resin, and a second type of amorphous resin, wherein the first type of amorphous resin and the second type of amorphous resin are present in the one or more fluorescent latexes in a weight ratio ranging from 2:3 to 3:2; forming a mixture comprising the one or more fluorescent latexes, a dispersion comprising aluminum flakes and a surfactant, and one or more emulsions comprising a crystalline resin, the first type of amorphous resin, the second type of amorphous resin, and optionally a wax dispersion; agglomerating the mixture to form particles of a predetermined size; forming a shell over said particle of said predetermined size to form a core-shell particle; and coalescing the core-shell particles to form a fluorescent metallic toner, wherein the fluorescent metallic toner is a fluorescent gold toner and the one or more fluorescent latexes include a red fluorescent agent and a yellow fluorescent agent.
2. 10. The method of claim 1, wherein the first type of amorphous resin and the second type of amorphous resin are present in the one or more fluorescent latexes in a 1:1 weight ratio.
3. 2. The method of claim 1, wherein the red fluorescent agent is selected from the group consisting of Solvent Red 49, Solvent Red 149, and combinations thereof, and the yellow fluorescent agent is selected from the group consisting of Solvent Yellow 160:1, Solvent Yellow 172, Solvent Yellow 98, and combinations thereof.
4. 4. The method of claim 3, wherein the crystalline resin is poly(1,6-hexylene-1,12-dodecanoate), the first type of amorphous resin is poly(propoxylated bisphenol-co-terephthalate-fumarate-dodecenyl succinate), and the second type of amorphous resin is poly(propoxylated-ethoxylated bisphenol-co-terephthalate-dodecenyl succinate-trimellitic anhydride).
5. The fluorescent gold toner has a density of 0.65 mg / cm 2 At least 64 L in the TMA * , 0.45mg / cm 2 5. The method of claim 4, characterized by a reflectance of at least 30 in the wavelength range of 500 nm to 600 nm at a TMA of 0.1, or both.
6. The fluorescent metallic toner has a density of 0.65 mg / cm 2 At least 64 L in the TMA * , 0.45mg / cm 2 2. The method of claim 1, wherein the toner is a fluorescent gold toner characterized by a reflectance of at least 30 in the wavelength range of 500 nm to 600 nm at a TMA of 0.15 or both.
7. The method of claim 1 , wherein the crystalline resin, the first type of amorphous resin, and the second type of amorphous resin are polyesters.
8. The crystalline polyester resin has Formula I: 【Chemistry 1】 Formula I wherein each of a and b ranges from 1 to 12, and p ranges from 10 to 100.
9. The method of claim 7, wherein the crystalline polyester resin is poly(1,6-hexylene-1,12-dodecanoate).
10. 8. The method of claim 7, wherein the first type of amorphous polyester resin is poly(propoxylated bisphenol-co-terephthalate-fumarate-dodecenyl succinate) and the second type of amorphous polyester resin is poly(propoxylated-ethoxylated bisphenol-co-terephthalate-dodecenyl succinate-trimellitic anhydride).
Citation Information
Patent Citations
Toner for electrophotography, image forming method, and process cartridge
JP2012208142A
Toner set for electrostatic charge image development, electrostatic charge image developer set, toner cartridge set, process cartridge set, image forming apparatus, and image forming method
JP2016156962A
Developer, developer container, development device, and image formation device
JP2018017840A