JP6077567B2 - Chemical toner formulation containing borax coupling agent - Google Patents

Description

[Cross-reference of related applications]
This application is a related application of US Patent Application No. 13 / 339,565 (Attorney Docket No. P7-US1) filed on December 29, 2011. The name of the invention of the previous application is “Method for producing toner containing borax coupling agent” and is assigned to the applicant of the present application.

1. FIELD OF THE DISCLOSURE The present invention relates generally to chemical toners used in electrophotography, and more specifically to chemical toners containing a borax coupling agent.

2. Disclosure of Related Art There are two main types of toners used in electrophotography: toner by mechanical milling and chemical toner (CPT). Chemical toners are superior to mechanical milling toners in printing quality, have high toner transfer efficiency, and have low torque characteristics for various components of electrophotographic printers such as developing rollers, fixing belts, and charging rollers. Have advantages. The particle size distribution of CPT is generally narrower than the particle size distribution of toner by mechanical milling. Further, the size and shape of the CPT are easier to adjust than the toner by mechanical milling.

  CPT includes suspension polymerization toner (SPT), emulsion aggregation toner (EAT) / latex aggregation toner (LAT), toner obtained by dispersing a preformed polymer in a solvent (DPPT), and toner by “chemical milling”. There are several known types, including: Emulsion agglomerated toners require a more complex production process than other CPT toners, but provide a relatively narrow particle size distribution. Since the emulsion aggregation toner can be produced with a smaller particle size, the printing resolution can also be improved. In the emulsion aggregation process, the shape and structure of the toner particles can be controlled better, so that the toner particles can be adjusted to meet the desired cleaning characteristics, doctoring characteristics, and transfer characteristics. The shape of the toner particles is optimized to properly and efficiently clean the toner from various components of the electrophotographic printer such as the developing roller, charging roller, and doctor blade. This is to prevent filming and toner accumulation on the components.

  In a typical process for providing EAT, emulsion aggregation is carried out in an aqueous system where both toner size and shape can be well controlled. The toner component typically includes a polymer binder, one or more colorants, and a release agent. In the emulsion aggregation process, a polymer binder of a styrene-acrylic copolymer is often used as a latex binder. However, latex binders of styrene-acrylic copolymers require a trade-off between toner fixing properties and their transport and storage properties. The toner fixing characteristics include the fixing window. The fixing window is a temperature at which the toner is satisfactorily fixed without poor toner fixing or transfer to the toner heating element (roller, belt, or other component that comes into contact with the toner during toner fixing). A range. Therefore, at temperatures below the lower limit of the fixing window, the toner is incompletely melted, and at temperatures above the upper limit of the fixing window, the toner flows onto the fixing member, ruining the paper on which the toner is fixed. It is preferable to improve printer safety and save energy by making the lower limit of the fixing window as low as possible and reducing the temperature required of the fuser of an electrophotographic printer. However, the toner must be able to survive extreme temperature and humidity environments associated with transportation and storage without causing condensation or consolidation that can result in defective printing. Therefore, the lower limit of the fixing window cannot be excessively lowered in order to keep the toner in a molten state even while the toner cartridge containing the toner is transported and stored.

  Toners formed from polyester binder resins generally have better mechanical properties than toners formed from styrene-acrylic copolymer binders having similar melt viscosity characteristics. This provides durability and resistance to printer component filming. Polyester toners are also highly compatible with colored pigments, resulting in a wider color gamut. Until recently, polyester binder resins were used in toners by mechanical milling, but were rarely used in chemical toners. The polyester binder resin is produced by condensation polymerization. This method is time consuming due to the long polymerization cycle, thus limiting the use of polyester binder resins for polyester polymers having low to medium molecular weights that limit toner fixing properties. In addition, polyester binder resins are more difficult to disperse in aqueous systems because their polar nature, pH sensitivity, and gel content limit their applicability in the emulsion aggregation process.

  However, as the toner production technology advances, the polyester binder resin is first dissolved in an organic solvent such as methyl ethyl ketone (MEK), methylene chloride, ethyl acetate, or tetrahydrofuran (THF), and then the organic solvent Through the phase inversion process in which water is slowly added to the emulsion, a stable emulsion can be obtained using the polyester binder resin. As the organic solvent evaporates, the polyester binder resin forms a stable emulsion. US Pat. No. 7,939,236, entitled “Chemical Toner and Method for Producing the Same”, which is identical to the present application and incorporated by reference into this application, is similar to that for obtaining stable emulsions using organic solvents. This method is disclosed. These advantages lie in the fact that it is possible to produce an emulsion aggregation toner using a polyester binder resin. For example, U.S. Patent No. 7,923,191 entitled "Polyester Resin Produced by Emulsion Aggregation" and "Emulsion Aggregation Toner Formulation" filed by the same applicant as the present application and the entire disclosure of which is incorporated herein by reference. US patent application Ser. No. 12 / 206,402, entitled “A”, discloses a method for producing an emulsion aggregation toner using a polyester binder resin.

  These techniques provide the ability to produce emulsion-aggregated toners with excellent meltability, however, the problems associated with the surface migration of low molecular weight resins, waxes and colorants remain. When these components move to the surface of the toner particles, the toner fixing property and the transport / storage property are lowered, and the occurrence of filming on the printer part is increased. Accordingly, there is a need for an emulsion agglomerated toner formulation and method for producing the same that reduces the migration of low molecular weight resins, waxes and colorants to the toner particle surface. It is also desirable to minimize the total number of fine toner particles that facilitate filming on printer parts.

  A chemical toner composition according to an embodiment of the present invention includes a core including a first polymer binder, a colorant, and a release agent, and a shell formed around the core and including a second polymer binder. A borax coupling agent is contained between the core and the shell.

  The above features, other features and advantages of various embodiments, and how to achieve them, will become more apparent and better understood by referring to the accompanying drawings.

It is the conventional emulsion aggregation toner particle image image | photographed using the scanning electron microscope. 6 is an emulsion aggregated toner particle image according to one embodiment including a borax coupling agent between the toner core and shell layers. The emulsion aggregation toner according to an embodiment containing a borax coupling agent between the toner core and the shell layer, wherein the pH adjustment window includes a zinc sulfate coupling agent or an aluminum sulfate coupling agent. It is a graph compared with that of an emulsion aggregation toner.

  The following description and drawings illustrate embodiments sufficient for those skilled in the art to practice the invention. It is understood that the present disclosure is not limited to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments not described in the specification and may be practiced and carried out in various forms. For example, in other embodiments, structural changes, changes over time, process changes, and other changes can be incorporated. The examples merely typify possible variations. Individual components and functions are arbitrary unless otherwise specified, and a series of operations may be changed. Some embodiments and features may be included in, or substituted for, other embodiments. The scope of the present application includes the appended claims and a description of all available equivalents. The following description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims. Similarly, the expressions and terms used herein are for purposes of illustration and are not to be understood as limiting. As used herein, the terms “including”, “comprising” or “having” and like terms encompass the items listed thereafter and equivalents thereof as well as additional items.

  The present disclosure relates to chemically prepared toners that include a borax coupling agent between the toner core and shell layers, and emulsion aggregation processes associated with the preparation of such toners. The toner can be useful in electrophotographic printers such as printers, copiers, multifunction devices or all-in-one devices. The toner can be provided in a cartridge that supplies toner to the electrophotographic printer. Exemplary methods of producing toner using conventional emulsion aggregation techniques can be found in US Pat. No. 6,531,254, or US Pat. No. 6,531,256, which is hereby incorporated by reference in its entirety.

  In the emulsion aggregation method in the present disclosure, toner particles are provided by a scientific method as opposed to a physical method such as a grinding method. Generally, the toner includes one or more optional binders such as one or more polymer binders, release agents, colorants, borax coupling agents, and charge control agents (CCAs). The polymer binder emulsion is formed in water, and optionally in water containing an organic solvent, using an inorganic base such as sodium hydroxide, potassium hydroxide, ammonium hydroxide, or an organic amine compound. A stabilizer having an anionic functional group (A-), for example, an anionic surfactant or an anionic polymer dispersant, may also be included. If necessary, it may be substituted with a cationic functional group (C +), for example, a cationic surfactant or a cationic polymer dispersant. Polymer latex is used in two places in the toner production process. The first part of the polymer latex is used to form the core of the resulting toner particles, and the second part of the polymer latex is used to form a shell around the core of the toner. The first and second portions of the polymer latex can be formed separately or simultaneously. If the first part of the polymer latex that forms the toner core and the second part that forms the shell are formed separately, either the same or different polymer binders can be used. The weight ratio of the amount of polymer binder in the toner core to the amount of toner contained in the shell is from about 20:80 to about 80:20. Depending on the particular resin used, such as from about 50:50 to about 80:20, the range includes all values and increases within the range.

  The colorant, release agent, and optional CCA are dispersed separately in their own aqueous environment or in one aqueous mixed solvent. Moreover, it disperse | distributes in the presence of the stabilizer which has the function (and ionic charge) similar to the stabilizer used for polymer latex as needed. The polymer latex that forms the core of the toner, the release agent dispersion, the colorant dispersion, and the optional CCA dispersion are mixed and stirred to obtain a homogeneous composition. As used herein, the term dispersion means a system in which particles are dispersed in continuous phases of different compositions (or states) and may include an emulsion. Then, acid is added to lower the pH and cause soft aggregation. Soft agglomeration means that unstable particles (in the presence of available counterions) come together to form relatively large agglomerates. In this case, soft agglomeration involves the formation of a gel where the resin, colorant, release agent, and CCA form an agglomerate mixture, typically 1-2 micron (μm) in size. Unless stated otherwise, the particle size herein refers to the maximum cross-sectional dimension of the particle. Aggregated toner particles are heated to a temperature below or near the glass transition temperature (Tg) of the polymer latex (eg, ± 5 ° C.) to induce cluster growth of the agglomerated particles. When the agglomerated particles reach the desired size for the toner core, a borax coupling agent is added to form on the toner core surface. Following the addition of the borax coupling agent, a polymer latex that forms the toner shell is added. The polymer latex aggregate forms a shell around the toner core. Once the agglomerated particles reach the desired size for the toner, a base may be added to prevent further growth of the particles by increasing the pH and reionizing the anionic stabilizer, or anionic stabilization An agent may be further added. The temperature is then raised to the glass transition temperature of the polymer latex, causing the particles in each cluster to fuse together. This temperature is maintained until the particles are in the desired perfect circle. Thereafter, the toner particles are washed and dried.

  The toner particles produced have an average particle size (volume average particle size) of about 3 μm to about 20 μm, about 4 μm to about 15 μm, and more specifically, all of the above ranges, such as about 5 μm to about 7 μm. Includes value and increment. The toner particles produced have an average roundness of about 0.90 to about 1.00, including all values and increments in the above range, such as from about 0.93 to about 0.98. The average roundness and the average particle diameter can be measured using a flow type particle image analyzer (for example, FPIA-3000) manufactured by Sysmex, which is available from Malvern.

  The various components of the emulsion aggregation process for preparing the toner described above are described below. It should be noted that all the various features of the components shown can be adjusted to aid in the step for agglomerating and producing toner particles having a desired size and geometry. Therefore, by controlling the indicated characteristics, it is possible firstly to produce a relatively stable dispersion, in which case the final toner particle size for use in an electrophotographic printer or printer cartridge. Can be controlled relatively easily to promote aggregation.

[Polymer binder]
As described above, the toners described herein contain one or more polymer binders. The terms resin and polymer are used interchangeably and there is no technical difference between the two terms herein. In one embodiment, the polymer binder comprises polyester. The polyester binder can include a semi-crystalline polyester binder, a crystalline polyester binder, or an amorphous polyester binder. Alternatively, the polyester binder may include a polyester copolymer binder resin. For example, the polyester binder may comprise a styrene / acryl-polyester graft copolymer. The polyester binder can be formed using acid monomers such as terephthalic acid, trimellitic anhydride, dodecenyl succinic anhydride, and fumaric acid. In addition, polyester binders can be formed using alcohol monomers such as ethoxylated and propoxylated bisphenol A. Exemplary polyester resins are T100, TF-104, NE-1582, NE-701, NE-2141, NE-1569, Binder C, FPESL-2, W-85N, TL-17 sold by Kao Corporation. , TPESL-10, TPESL-11 polyester resin, or a mixed resin thereof, but is not limited thereto.

  In other embodiments, the polymer binder is a styrene polymer and / or a substituted styrene polymer, such as a homopolymer (eg, polystyrene) and / or a copolymer (eg, a styrene-butadiene copolymer and / or a styrene-acrylic copolymer, styrene-butyl). Methacrylate copolymers and / or thermoplastic polymers such as styrene-butyl acrylate and other acrylic monomers such as hydroxy acrylate or hydroxymethyl acrylate), polyvinyl acetate, polyalkenes, poly ( Vinyl chloride), polyurethane, polyamide, silicone, epoxy resin, or phenol resin.

  As described above, in some embodiments, the toner core is formed from one polymer binder (or mixture) and the toner shell is formed from the other. Further, the weight ratio of the amount of polymer binder contained in the toner core to the amount of toner contained in the toner shell is from about 20:80 to about 80:20, and more specifically from about 50:50 to about 80. : 20, including all values and increments in the above range. The average total amount of polymer binder can be from about 70% to about 95% by weight of the final toner formulation, including all values and increments in this range.

[Borax coupling agent]
The coupling agent used herein is borax (sodium borate, sodium tetraborate, or disodium tetraborate). As used herein, the term coupling agent refers to a compound that has the ability to crosslink two or more components. In general, the coupling agent has multivalent binding properties. It differs from commonly used permanent coupling agents such as polyvalent metal ions (eg, aluminum and zinc) in that borax coupling is reversible. In electrophotographic processes, the toner has low melting temperature properties to save energy, and has low melt viscosity ("soft") to enable high speed printing at low fusing temperatures; Is preferred. However, in order to maintain stability during transport and storage and to prevent filming on the printer parts, it is preferred that the toner be “hard” at temperatures below the fusing temperature. Borax provides a bridge through hydrogen bonding between the hydroxy group and the functional group of the molecule attached to it. Hydrogen bonds are sensitive to temperature and pressure and are not stable and permanent bonds. For example, if the temperature rises to some extent, or if the polymer is stressed, the bond will be partially or completely broken and the polymer will “flow” and become detached. The reversibility of binding by borax coupling agents is particularly useful for toners because it “softens” the toner at the melting temperature and “hardens” the toner at the storage temperature.

  In borax, it was surprisingly observed that fine particles were collected into larger particles. Thus, borax is particularly suitable as a binder between the toner core and shell layers. This is because, before the shell is bonded to the core, the core particles can collect the core component of the toner, and the residual fine particles in the toner are reduced. This can reduce the amount of acid required for the aggregation stage and narrow the toner particle size distribution.

  As a result of forming an equilibrium between boric acid and a conjugated base, borax also functions as a good buffer in the toner forming reaction. The presence of borax makes the reaction more resistant to pH changes and widens the pH adjustment window of the reaction compared to conventional emulsion aggregation processes. The pH adjustment window is important in the industrial scale-up of processes that control particle size. Widening the window makes it easier to control the process on an industrial scale.

  The amount of borax coupling agent used herein can vary. The borax coupling agent can be about 0.1 wt% to about 5.0 wt%, about 0.1 wt% to about 1.0 wt%, or the polymer binder in the toner, or All values and increments within the above range can be included, such as about 0.1 wt% to about 0.5 wt%. If an excessive amount of coupling agent is used, such a bond may not be completely released when the toner is fixed at a high temperature. On the other hand, if an excessive amount of coupling agent is used, the desired binding effect and buffering effect may not be obtained.

[Colorant]
A colorant is a composition that imparts a color or other visual effect to a toner, such as carbon black, dyes (those that are soluble and can precipitate in a given medium), pigments (for a given medium) It may be insoluble) or a mixture of the two. The colorant dispersion can be prepared by mixing a pigment in water containing a dispersant. Moreover, if it is a self-dispersing colorant, it can be used without using a dispersant. The colorant can be dispersed in the dispersant liquid at a rate of about 5% to about 20% by weight, including all values and increments therebetween. For example, the colorant can be present in a proportion of about 10% to about 15% by weight. The colorant dispersion can also include particles from about 50 nanometers (nm) to about 500 nm, including all values and increments within these ranges. Further, in the colorant dispersion, the pigment weight percent divided by the dispersant weight percent (ratio P / D) can be about 1: 1 to about 8: 1, such ratio being , Including all values and increments of the range, such as from about 2: 1 to about 5: 1. The colorant can include up to about 15% by weight of the final toner formulation and can include all values and increments in this range.

[Release agent]
The release agent can include any compound that promotes toner release from the components of the electrophotographic printer (eg, toner release from the roller surface). For example, the mold release agent includes polyolefin wax, ester wax, polyester wax, polyethylene wax, fatty acid metal salt, fatty acid ester, partially saponified fatty acid ester, higher fatty acid ester, higher alcohol, paraffin waxes, carnauba wax, amide wax, And polyhydric alcohol esters.

  Accordingly, the release agent may comprise a low molecular weight hydrocarbon-based polymer (eg, Mn ≦ 10,000) having a melting point less than about 140 ° C., the melting point ranging from about 50 ° C. to about 140 ° C. All values and increments are included. For example, the release agent may have a melting point such as about 60 ° C. to about 135 ° C., or about 65 ° C. to about 100 ° C. The release agent can be present in the dispersion in a proportion of about 5% to about 35% by weight, including all values and increments in this range. For example, the release agent may be present in the dispersion at a rate of about 10% to about 18% by weight. The release agent dispersion can include particles of a size of about 50 nm to about 1 μm, including all values and increments in this range. In addition, the release agent can be characterized as having a release agent weight percent divided by the dispersion weight percent (ratio RA / D) of about 1: 1 to about 30: 1. For example, the ratio RA / D is about 3: 1 to about 8: 1. The release agent can be from about 2% to about 20% by weight of the final toner formulation and includes all values and increments in this range.

[Surfactant / Dispersant]
Surfactants, polymer dispersants, or mixtures thereof can be used. Polymeric dispersants can generally include three components: a hydrophilic component, a hydrophobic component, and a protective colloid component. Hydrophobicity refers to a nonpolar chemical structure that tends to self-associate with the presence of water. The hydrophobic component of the polymeric dispersant can include electron rich functional groups or long chain hydrocarbons. Such functional groups are known to exhibit strong interaction and / or adsorption properties on the particle surface as a colorant and polyester binder resin in a polyester resin emulsion. A hydrophilic functional group refers to a relatively polar functional group (eg, an anionic group) that tends to associate with moisture thereafter. The protective colloid component contains a water-soluble group having a nonionic function. The protective colloid component of the polymer dispersant provides additional stability in addition to the hydrophilic component in the aqueous system. The use of a protective colloid component substantially reduces the amount of ionic monomer segment or hydrophilic component of the polymer dispersant. Furthermore, the protective colloid component stabilizes the polymer dispersant in a less acidic medium. The protective colloid component generally comprises polyethylene glycol (PEG) groups. Dispersants used herein are disclosed in US Pat. No. 6,991,884 and US Pat. No. 5,714,538, all of which are hereby incorporated by reference.

  The surfactants used herein are used to prepare electrophotographic toner formulations and are known in the art for use in dispersing non-self-dispersing colorants and release agents. A normal surfactant can be used. Commercially available surfactants such as the AKYPO series of carboxylic acids sold by Kao Corporation (Sumida-ku, Tokyo, Japan) can be used. For example, alkyl ether carboxylates and alkyl ether sulfates, preferably lauryl ether carboxylates and lauryl ether sulfates, respectively, can be used. One particularly suitable anionic surfactant is AKYPO RLM-100, available from Kao Corporation, which is a laureth-11 carboxylic acid that provides anionic carboxylate function. Other anionic surfactants contemplated herein include alkyl phosphates, alkyl sulfonates, alkyl benzene sulfonates. Sulfonic acids containing polymers or surfactants can also be used.

[Optional additives]
The toner formulations of the present disclosure can include one or more conventional charge control agents and can be used in the preparation of toner formulations. A charge control agent can be understood as a compound that aids in the generation and stability of triboelectric charges in the toner. The charge control agent also helps to prevent charge deterioration of the toner formulation. The charge control agent can be in the form of a dispersion, similar to the colorant and release agent dispersion described above.

  The toner formulation may include additional additives such as one or more of acids and / or bases, emulsifiers, UV absorbers, fluorescent additives, pearlescent additives, plasticizers, and combinations thereof. it can. These additives can be expected to enhance the properties of image prints using the toner formulations of the present disclosure. For example, UV absorbers can be used to increase UV fading resistance, thereby preventing subsequent fading of the image when exposed to UV radiation. Suitable examples of UV absorbers include, but are not limited to, benzophenone, benzotriazole, acetanilide, triazine and derivatives thereof. Commercially available plasticizers known in the art can also be used to adjust the fusing temperature of the toner formulation.

  The following examples are provided to illustrate the teachings of the present disclosure and do not limit the scope of the present disclosure.

[Example Magenta Pigment Dispersion]
About 10 g of AKYPO RLM-100 polyoxyethylene (10) lauryl ether carboxylic acid manufactured by Kao Corporation was mixed with about 350 g of deionized water whose pH was adjusted to about 7-9 using sodium hydroxide. About 10 g of Solsperse 27000 manufactured by Lubrizol Advanced Materials, Cleveland, Ohio, USA is added, 100 g of red pigment 122 is added relatively slowly, and then the mixture of dispersant and water is added to the electric stirrer. Mixed with. When the pigment was completely wet and dispersed, the dispersion and water mixture was added to the horizontal media mill to reduce the particle size. The solution was treated with a media mill until the particle size was about 200 nm. The final pigment dispersion was set to contain about 20 wt% to about 25 wt% solids.

[Example Cyan Pigment Dispersant Liquid]
About 10 g of AKYPO RLM-100 polyoxyethylene (10) lauryl ether carboxylic acid manufactured by Kao Corporation was mixed with about 350 g of deionized water whose pH was adjusted to about 7-9 using sodium hydroxide. Add about 10g of Solsperse 27000, manufactured by Lubrizol Advanced Materials, Cleveland, Ohio, USA, and add 100g of blue pigment 15: 3 relatively slowly, followed by the mixture of dispersant and water. Mix with a stirrer. When the pigment was completely wetted and dispersed, the dispersion and water mixture was added to the horizontal media mill to reduce the particle size. The solution was treated with a media mill until the particle size was about 200 nm. The final pigment dispersion was set to contain about 20 wt% to about 25 wt% solids.

Exemplary wax emulsion
About 12 g of AKYPO RLM-100 polyoxyethylene (10) lauryl ether carboxylic acid manufactured by Kao Corporation was mixed with about 325 g of deionized water whose pH was adjusted to about 7-9 using sodium hydroxide. The mixture was then treated with a microfluidizer and heated to about 90 ° C. About 60 g of polyethylene wax from Petrocorp, Westlake, Ohio, USA, was slowly added over about 15 minutes while maintaining the temperature at about 90 ° C. When the particle size was about 300 nm or less, the emulsion was removed from the microfluidizer. The solution was then stirred at room temperature. The wax emulsion was set to contain about 10% to about 18% by weight of the solid component.

[Example Polyester Resin Emulsion A]
A mixed polyester resin having a peak molecular weight of about 9000, a glass transition temperature (Tg) of about 53 ° C. to about 58 ° C., a melting temperature (Tm) of about 110 ° C. and an acid number of about 15 to about 20 was used. The glass transition temperature was measured by differential scanning calorimetry (DSC). In this case, when the baseline (heat capacity) shift begins, the Tg is shown to be about 53 ° C. to about 58 ° C. at a heating rate of about every 5 minutes. The acid number may be due to the presence of one or more free carboxylic acid functional groups (—COOH) in the polyester. The acid value is a measure of the amount of carboxylic acid groups in the polyester because it indicates the mass of potassium hydroxide (KOH) required to neutralize 1 g of the polyester in milligrams.

  150 g of the mixed polyester resin was dissolved in 450 g of methyl ethyl ketone (MEK) in the round bottom flask while stirring. The dissolved resin was then poured into a beaker. The beaker was placed directly into the ice bath under the homogenizer. The homogenizer was started in high shear mode and 10 g of 10% potassium hydroxide (KOH) solution and 500 g of deionized water were immediately added to the beaker. The homogenizer was operated in high shear mode for about 2-4 minutes and then the homogenized resin solution was placed in a vacuum distillation reactor. The reactor temperature was maintained at about 43 ° C. and the pressure was maintained at about 22 inHg to about 23 inHg. About 500 mL of additional deionized water was added to the reactor and the temperature was gradually increased to about 70 ° C. to ensure that substantially all MEK was distilled. The reactor heating was then stopped and the mixture was stirred until the reactor reached room temperature. When the reactor reached room temperature, the vacuum was released and the resin solution was transferred to a storage bottle.

  The particle size of the resin emulsion was about 185 nm to about 235 nm on a volume average as measured by a NANOTRAC particle size analyzer. The pH of the resin solution was about 6.5 to about 7.0.

[Example Polyester Resin Emulsion B]
Using a polyester resin having a peak molecular weight of about 11,000, a glass transition temperature (Tg) of about 55 ° C. to about 60 ° C., a melting temperature (Tm) of about 110 ° C., and an acid number of about 15 to about 20, An emulsion was prepared according to the procedure described in Exemplary Polyester Resin A. However, the 10% potassium hydroxide (KOH) solution used is 8 g.

  The particle size of the resin emulsion was about 195 nm to about 235 nm on a volume average as measured with a NANOTRAC particle size analyzer. The pH of the resin solution was about 6.7 to about 7.2.

[Example Polyester Resin Emulsion C]
Using a polyester resin having a peak molecular weight of about 11,000, a glass transition temperature (Tg) of about 55 ° C. to about 58 ° C., a melting temperature (Tm) of about 115 ° C., and an acid number of about 8 to about 13, An emulsion was prepared according to the procedure described in Exemplary Polyester Resin A. However, the 10% potassium hydroxide (KOH) solution used is 7 g.

  The particle size of the resin emulsion was about 190 nm to about 240 nm in volume average as measured with a NANOTRAC particle size analyzer. The pH of the resin solution was about 7.5 to about 8.2.

[Example of toner formulation]
[Comparative Example Toner I]
Comparative Toner I was obtained using a conventional emulsion aggregation process and does not contain a borax coupling agent. The emulsion aggregation CPT used in the comparative toner I is an acid aggregate having pH reversibility, and the pH reversibility was used to stop the growth of toner particles. The components were added to a 2.5 liter reactor in the following relative proportions. That is, 88.2 parts of exemplary polyester resin emulsion A (by weight of polyester), 6.8 parts of exemplary magenta pigment dispersion (by weight of pigment), and 5 parts of exemplary wax emulsion (of release agent) By weight). Deionized water was added so that the mixture contained about 12.5% solids by weight.

  The mixture was heated in the reactor to 30 ° C. and a circulation loop consisting of a high shear mixer and acid addition pump was started. The mixture was sent through a circulation loop and the high shear mixer was set at 10,000 revolutions per minute (rpm). In order to uniformly disperse the acid in the toner, the acid was slowly added to the high shear mixer to disperse it uniformly, so that pockets having a low pH were not generated. The acid addition was performed using 306 g of 1% sulfuric acid solution over about 4 minutes. Thereafter, the loop flow was reversed and the toner mixture was returned to the reactor. The reactor temperature was raised to 50 ° C. to grow the particles. The reactor temperature was maintained at about 50 ° C. until the particles reached the desired size (number average particle size from about 5 μm to about 6 μm, volume average particle size from about 6 μm to about 7 μm). When the particles reached the desired size, 4% NaOH was added to raise the pH to 6.00 to stop particle growth. The reaction was carried out at a temperature of about 50 ° C. for about 1 hour. Subsequently, the temperature was raised to 91 ° C. to aggregate the particles. The temperature was held at 91 ° C. until the particles reached the desired roundness (about 0.97).

  The volume average particle size of the dried toner was about 6.0 μm as measured by Coulter Counter Multisizer 3 analyzer. 4.16% of fine powder (less than 2 μm) was present, and the roundness of the toner was 0.970. These were measured with a SYSMEX FPIA-3000 particle characterization analyzer manufactured by Malvern, Inc., Worcestershire, England. The amount of fine powder of Comparative Example toner I was the same as that of other emulsion aggregation polyester toners having no borax coupling agent and having 1 to 7% fine powder.

  Using the construction and procedure of Comparative Toner I, several additional Comparative Toners were made. For additional comparative toners, the neutralizing solution was modified to test the pH adjustment window. The test results of these toners are shown in Table 2 below.

[Example Toner A]
Exemplary polyester resin emulsion A was divided into two batches, each divided into a weight ratio of 70:30 so as to form a toner core and shell. The total polyester content accounted for about 87.7% of the total solids of the toner. Thus, the first batch accounted for 61.4% of the total solids of toner and the second batch accounted for 26.3% of the total solids of toner. Each component was added to a 2.5 liter reactor in the following proportions. That is, the first batch of exemplary polyester resin emulsion A is 61.4 parts (by weight of polyester), the exemplary magenta pigment dispersion is 6.8 parts (by weight of pigment), and the exemplary wax emulsion is 5 Parts (by weight of release agent). Then deionized water was added so that the mixture contained about 12% to about 15% by weight.

  The mixture was heated in the reactor to 30 ° C. and a circulation loop consisting of a high shear mixer and acid addition pump was started. The mixture was sent through a circulation loop and the high shear mixer was set at 10,000 rpm. In order to uniformly disperse the acid in the toner, the acid was slowly added to the high shear mixer to disperse it uniformly, so that pockets having a low pH were not generated. The acid addition was performed using 200 g of a 1% sulfuric acid solution over about 4 minutes. Thereafter, the flow of the loop was reversed, the toner mixture was returned to the reactor, and the temperature of the reactor was raised to about 40 ° C to 45 ° C. When the particle size (number average) reached 4.0 μm, a 5% (wt.) Borax solution (1.5 g borax in a 30 g container) was added. Borax accounted for about 0.5% by weight of the total solids of the toner. After the borax was added, a second batch of exemplary polyester resin emulsion A was added. The second batch contains 26.3 parts (by weight of polyester). The mixture was stirred for about 5 minutes and the pH was monitored. When the particle size (number average) reached 5.5 μm, 4% NaOH was added to raise the pH to 5.95 to stop particle growth. The reaction temperature was maintained for 1 hour. The particle size was monitored in the meantime, and when particle growth stopped, the temperature was raised to 88 ° C. to aggregate the particles. The temperature was maintained until the particles were of the desired roundness (about 0.97). Thereafter, the toner was washed and dried.

  The dried toner had a volume average particle size of 6.65 μm and a number average particle size of 5.49 μm. Fine powder (less than 2 μm) was present in a number of 0.11% and had a roundness of 0.978.

  Using the construction and procedure of Example Toner A, several additional Example Toners were made. For additional example toners, the neutralization solution was changed to test the pH adjustment window. The test results of these toners are shown in Table 2 below.

[Example Toner B]
The exemplary polyester resin emulsion A was divided into two batches, each divided at a 60:40 weight ratio so as to form a toner core and shell. The total polyester content accounted for about 87.9% of the total solids of the toner. Thus, the first batch accounted for 52.7% of the total solids of toner and the second batch accounted for 35.2% of the total solids of toner. Each component was added to a 2.5 liter reactor in the following proportions. That is, the first batch of exemplary polyester resin emulsion A is 52.7 parts (by weight of polyester), the exemplary magenta pigment dispersion is 6.8 parts (by weight of pigment), and the exemplary wax emulsion is 5 Parts (by weight of release agent). Then deionized water was added so that the mixture contained about 12% to about 15% by weight.

  The mixture was heated in the reactor to 30 ° C. and a circulation loop consisting of a high shear mixer and acid addition pump was started. The mixture was sent through a circulation loop and the high shear mixer was set at 10,000 rpm. In order to uniformly disperse the acid in the toner, the acid was slowly added to the high shear mixer to disperse it uniformly, so that pockets having a low pH were not generated. The acid addition was performed using 150 g of 1% sulfuric acid solution over about 4 minutes. Thereafter, the flow of the loop was reversed, the toner mixture was returned to the reactor, and the temperature of the reactor was raised to about 40 ° C to 45 ° C. When the particle size (number average) reached 4.0 μm, a 5% (wt.) Borax solution (0.75 g borax in a 15 g container) was added. Borax accounted for about 0.3% by weight of the total solids of the toner. After the borax was added, a second batch of exemplary polyester resin emulsion A was added. The second batch contains 35.2 parts (by weight of polyester). The mixture was stirred for about 5 minutes and the pH was monitored. When the particle size (number average) reached 5.5 μm, 4% NaOH was added to raise the pH to 5.95 to stop particle growth. The reaction temperature was maintained for 1 hour. The particle size was monitored in the meantime, and when particle growth stopped, the temperature was raised to 88 ° C. to aggregate the particles. The temperature was maintained until the particles reached the desired roundness (about 0.97). Thereafter, the toner was washed and dried.

  The dried toner had a volume average particle size of 6.24 μm and a number average particle size of 5.48 μm. Fine powder (less than 2 μm) was present in a number of 0.09% and had a roundness of 0.983.

[Example Toner C]
Exemplary polyester resin emulsion A and exemplary polyester resin emulsion C are mixed liquids used in a weight ratio of 70:30, each forming a toner core and shell. The total polyester content accounted for about 87.9% of the total solids of the toner. Thus, exemplary polyester resin emulsion A accounted for 61.5% of the total solids of the toner, and exemplary polyester resin emulsion C accounted for 26.4% of the total solids of the toner. Each component was added to a 2.5 liter reactor in the following proportions. That is, 61.5 parts of exemplary polyester resin emulsion A (by weight of polyester), 6.8 parts of exemplary magenta pigment dispersion (by weight of pigment), and 5 parts of exemplary wax emulsion (release) By weight of the agent). Then deionized water was added so that the mixture contained about 12% to about 15% by weight.

  The mixture was heated in the reactor to 30 ° C. and a circulation loop consisting of a high shear mixer and acid addition pump was started. The mixture was sent through a circulation loop and the high shear mixer was set at 10,000 rpm. In order to uniformly disperse the acid in the toner, the acid was slowly added to the high shear mixer to disperse it uniformly, so that pockets having a low pH were not generated. The acid addition was performed using 200 g of a 1% sulfuric acid solution over about 4 minutes. Thereafter, the flow of the loop was reversed, the toner mixture was returned to the reactor, and the temperature of the reactor was increased to about 37 ° C to 42 ° C. When the particle size (number average) reached 4.0 μm, a 5% (wt.) Borax solution (0.75 g borax in a 15 g container) was added. Borax accounted for about 0.25% by weight of the total solids of the toner. Example polyester resin emulsion C was added after the borax was added. Exemplary polyester resin emulsion C contains 26.4 parts (by weight of polyester). The mixture was stirred for about 5 minutes and the pH was monitored. When the particle size reached 5.5 μm (number average), 4% NaOH was added to raise the pH to 6.60 to stop particle growth. The reaction temperature was maintained for 1 hour. The particle size was monitored in the meantime, and when particle growth stopped, the temperature was raised to 88 ° C. to aggregate the particles. The temperature was maintained until the particles were of the desired roundness (about 0.97). Thereafter, the toner was washed and dried.

  The dried toner had a volume average particle size of 6.40 μm and a number average particle size of 5.18 μm. Fine powder (less than 2 μm) was present (by number) in 0.92% and had a roundness of 0.970.

[Example Toner D]
Using a combination of an exemplary polyester resin emulsion A and an emulsion made of ACT-004 polyester resin manufactured by Toyobo Co., Ltd., Kita-ku, Osaka, Japan at a weight ratio of 70:30, the core and shell of the toner are respectively used Formed. ACT-004 polyester resin has a peak molecular weight of about 11,000, a glass transition temperature of about 57 ° C. to about 61 ° C., a melting temperature of about 104 ° C., and an acid value of about 16. The emulsion particle size is about 200 nm (by volume average). The total polyester content accounted for about 87.9% of the total solids of the toner. Thus, exemplary polyester emulsion A accounted for 61.5% of the total solids of the toner, and ACT-004 polyester emulsion accounted for 26.4% of the total solids of the toner. Each component was added to a 2.5 liter reactor in the following proportions. That is, the first batch of exemplary polyester resin emulsion A is 61.5 parts (by weight of polyester), the exemplary magenta pigment dispersion is 6.8 parts (by weight of pigment), and the exemplary wax emulsion is 5 Parts (by weight of release agent). Then deionized water was added so that the mixture contained about 12% to about 15% by weight.

  The mixture was heated in the reactor to 30 ° C. and a circulation loop consisting of a high shear mixer and acid addition pump was started. The mixture was sent through a circulation loop and the high shear mixer was set at 10,000 rpm. In order to uniformly disperse the acid in the toner, the acid was slowly added to the high shear mixer to disperse it uniformly, so that pockets having a low pH were not generated. The acid addition was performed using 200 g of a 1% sulfuric acid solution over about 4 minutes. Thereafter, the flow of the loop was reversed, the toner mixture was returned to the reactor, and the temperature of the reactor was raised to about 35 ° C to 40 ° C. When the particle size (number average) reached 4.0 μm, a 5% (wt.) Borax solution (0.75 g borax in a 15 g container) was added. Borax accounted for about 0.25% by weight of the total solids of the toner. After the borax was added, ACT-004 polyester resin emulsion was added. The ACT-004 polyester resin emulsion contains 26.4 parts (by weight of polyester). The mixture was stirred for about 5 minutes and the pH was monitored. When the particle size reached 5.5 μm (number average), 4% NaOH was added to raise the pH to 6.20 to stop particle growth. The reaction temperature was maintained for 1 hour. The particle size was monitored in the meantime, and when particle growth stopped, the temperature was raised to 88 ° C. to aggregate the particles. The temperature was maintained until the particles were of the desired roundness (about 0.97). Thereafter, the toner was washed and dried.

  The dried toner had a volume average particle size of 6.18 μm and a number average particle size of 5.28 μm. Fine powder (less than 2 μm) was present in a number of 0.42%, and the roundness was 0.973.

[Example Toner E]
Exemplary Polyester Resin Emulsion B was divided into two batches, each divided in a 70:30 weight ratio so as to form a toner core and shell. The total polyester content accounted for about 87.9% of the total solids of the toner. Thus, the first batch accounted for 61.5% of the total solids of toner and the second batch accounted for 26.4% of the total solids of toner. Each component was added to a 2.5 liter reactor in the following proportions. That is, the first batch of exemplary polyester resin emulsion B is 61.5 parts (by weight of polyester), the exemplary magenta pigment dispersion is 6.8 parts (by weight of pigment), and the exemplary wax emulsion is 5 Parts (by weight of release agent). Then deionized water was added so that the mixture contained about 12% to about 15% by weight.

  The mixture was heated in the reactor to 30 ° C. and a circulation loop consisting of a high shear mixer and acid addition pump was started. The mixture was sent through a circulation loop and the high shear mixer was set at 10,000 rpm. In order to uniformly disperse the acid in the toner, the acid was slowly added to the high shear mixer to disperse it uniformly, so that pockets having a low pH were not generated. The acid addition was performed using 200 g of a 1% sulfuric acid solution over about 4 minutes. Thereafter, the flow of the loop was reversed, the toner mixture was returned to the reactor, and the temperature of the reactor was raised to about 40 ° C to 45 ° C. When the particle size reached 5.0 μm (number average), a 5% (wt.) Borax solution (0.75 g borax in a 15 g container) was added. Borax accounted for about 0.25% by weight of the total solids of the toner. After the borax was added, a second batch of exemplary polyester resin emulsion B was added. The second batch contains 26.4 parts (by weight of polyester). The mixture was stirred for about 5 minutes and the pH was monitored. When the particle size reached 5.5 μm (number average), 4% NaOH was added to raise the pH to 7.10 to stop particle growth. The reaction temperature was maintained for 1 hour. The particle size was monitored in the meantime, and when particle growth stopped, the temperature was raised to 88 ° C. to aggregate the particles. The temperature was maintained until the particles were of the desired roundness (about 0.97). Thereafter, the toner was washed and dried.

  The dried toner had a volume average particle size of 7.24 μm and a number average particle size of 5.86 μm. Fine powder (less than 2 μm) was 1.76% in number and had a roundness of 0.974.

  From the above, the emulsion aggregation process in which the borax coupling agent was used between the core and the shell layer of the toner particles used to prepare the toners of Examples A to E was prepared as Comparative Example Toner I. It can be seen that the proportion of fine particles has been significantly reduced compared to the conventional emulsion agglomeration process used to achieve this. Further, it can be seen that Example toners A to E have an average particle size and roundness comparable to Comparative Example toner I, as desired.

[Test results]
[Surface movement]
FIG. 1 is a photograph of conventional emulsion aggregation toner particles 10 prepared according to Comparative Example I, taken using a scanning electron microscope (SEM). FIG. 2 shows emulsion aggregation toner particles 20. The particles 20 are particles prepared according to Example toner A, which contains a borax coupling agent between the core and shell layer of the toner. As shown, the toner particles 20 have a smoother and more uniform surface than the conventional emulsion aggregation toner particles 10. The smooth and uniform surface of the toner particles 20 reduces the occurrence of filming on the developing roller and improves the toner fixing performance at high temperatures. In contrast, conventional particles 10 have a large amount of colorant, release agent and low molecular weight resin particles 12 that have migrated to the particle surface. As mentioned above, borax surprisingly collects these particles in the toner core prior to the addition of the shell layer, thus preventing the particles from moving to the toner surface.

[Developing roller and doctor blade filming]
Tests were also performed on the developing roller and doctor blade filming of the toners A and B and the toner I of the comparative example. Each toner was placed in a toner cartridge. Each cartridge was then inserted into the test robot and operated at 50 ppm. The developing roller and doctor blade of each cartridge were regularly checked visually, and the amount of filming on the component by toner was measured. The amount of toner filming was ranked in 1 to 4 levels. The larger the rank (for example, rank 4), the greater the filming amount and the lower the performance. The test results are shown in Table 1 below.

  As shown in Table 1, with the exemplary toners A and B containing the borax coupling agent, the resistance to filming on the developing roller and the similar resistance to filming on the doctor blade are similar to those of Comparative Example Toner I. It can be seen that the comparison is improved.

  In order to further evaluate the performance of the borax coupling agent, a toner using zinc sulfate and a toner using aluminum sulfate were prepared as a coupling agent between the core and shell layer of the toner, respectively.

[Comparative Example Toner II]
Instead of using the borax coupling agent, Comparative Toner II was prepared using a zinc sulfate coupling agent. Exemplary polyester resin emulsion A was divided into two batches, each divided into a weight ratio of 70:30 so as to form a toner core and shell. The total polyester content accounted for about 90.3% of the total solids of the toner. Thus, the first batch accounted for 63.2% of the total solids of toner and the second batch accounted for 27.1% of the total solids of toner. Each component was added to a 2.5 liter reactor in the following proportions. That is, the first batch of exemplary polyester resin emulsion A is 63.2 parts (by weight of polyester), the exemplary cyan pigment dispersion is 4.4 parts (by weight of pigment), and the exemplary wax emulsion is 5 Parts (by weight of release agent). Then, deionized water was added so that the mixture contained about 12% to about 15% by weight.

  The mixture was heated in the reactor to 30 ° C. and a circulation loop consisting of a high shear mixer and acid addition pump was started. The mixture was sent through a circulation loop and the high shear mixer was set at 10,000 rpm. In order to uniformly disperse the acid in the toner, the acid was slowly added to the high shear mixer to disperse it uniformly, so that pockets having a low pH were not generated. The acid addition was performed using 175 g of 1% sulfuric acid solution over about 4 minutes. Thereafter, the flow of the loop was reversed, the toner mixture was returned to the reactor, and the temperature of the reactor was raised to about 40 ° C to 45 ° C. When the particle size reached 4.0 μm (on a number average), 5% (wt.) Aqueous zinc sulfate solution (0.9 g zinc sulfate contained in an 18 g container) was added. Zinc sulfate accounted for about 0.3% by weight of the total solids of the toner. After the zinc sulfate was added, a second batch of exemplary polyester resin emulsion A was added. The second batch contains 27.1 parts (by weight of polyester). When the particle size reached 5.5 μm (number average), 4% NaOH was added to raise the pH to 6.82 and to stop particle growth. The reaction temperature was maintained for 1 hour. The particle size was monitored in the meantime, and when particle growth stopped, the temperature was raised to 88 ° C. to aggregate the particles. The temperature was maintained until the particles were in the desired circle (about 0.97). Thereafter, the toner was washed and dried.

  The dried toner had a volume average particle size of 5.87 μm and a number average particle size of 4.98 μm. Fine powder (less than 2 μm) was present in a number of 1.12% and had a roundness of 0.972.

  Several additional comparative toners were made using the construction and procedure of Comparative Toner II. For the additional comparative toner, the neutralization solution was changed to test the pH adjustment window. The test results of these toners are shown in Table 2 below.

[Comparative toner III]
Instead of using the borax coupling agent, Comparative Example Toner III using an aluminum sulfate coupling agent was prepared. Exemplary polyester resin emulsion A was divided into two batches, each divided into a weight ratio of 70:30 so as to form a toner core and shell. The total polyester content accounted for about 90.3% of the total solids of the toner. Thus, the first batch accounted for 63.2% of the total solids of toner and the second batch accounted for 27.1% of the total solids of toner. Each component was added to a 2.5 liter reactor in the following proportions. That is, the first batch of exemplary polyester resin emulsion A is 63.2 parts (by weight of polyester), the exemplary cyan pigment dispersion is 4.4 parts (by weight of pigment), and the exemplary wax emulsion is 5 Parts (by weight of release agent). Then deionized water was added so that the mixture contained about 12% to about 15% by weight.

  The mixture was heated in the reactor to 30 ° C. and a circulation loop consisting of a high shear mixer and acid addition pump was started. The mixture was sent through a circulation loop and the high shear mixer was set at 10,000 rpm. In order to uniformly disperse the acid in the toner, the acid was slowly added to the high shear mixer to disperse it uniformly, so that pockets having a low pH were not generated. The acid addition was performed using 175 g of 1% sulfuric acid solution over about 4 minutes. Thereafter, the flow of the loop was reversed, the toner mixture was returned to the reactor, and the temperature of the reactor was raised to about 40 ° C to 45 ° C. When the particle size reached 4.0 μm (number average), a 5% (wt.) Aqueous solution of aluminum sulfate (0.9 g of aluminum sulfate contained in an 18 g container) was added. Aluminum sulfate accounted for about 0.3% by weight of the total solids of the toner. After the aluminum sulfate was added, a second batch of exemplary polyester resin emulsion A was added. The second batch contains 27.1 parts (by weight of polyester). When the particle size reached 5.5 μm (number average), 4% NaOH was added to raise the pH to 6.47 to stop particle growth. The reaction temperature was maintained for 1 hour. The particle size was monitored in the meantime, and when particle growth stopped, the temperature was raised to 88 ° C. to aggregate the particles. The temperature was maintained until the particles were in the desired circle (about 0.97). Thereafter, the toner was washed and dried.

  The dried toner had a volume average particle size of 6.10 μm and a number average particle size of 5.20 μm. Fine powder (less than 2 μm) was present in a number of 0.24% and had a roundness of 0.970.

  Several additional toners were made using the construction and procedure of Comparative Toner III. For the additional toner, the neutralization solution was changed to test the pH adjustment window. The test results of these toners are shown in Table 2 below.

[PH adjustment window]
The results of the pH adjustment window test for the above Comparative Example Toners I to III and Example Toner A are shown in FIG. 3 and Table 2 below. Specifically, FIG. 3 is a graph summarizing the data in Table 2.

  As shown in Table 2 and FIG. 3, the pH adjustment window of the toner having a coupling agent (borax, zinc sulfate, or aluminum sulfate) is remarkably larger than the adjustment window of the comparative toner I that is a conventional emulsion aggregation toner. I can see that it is wide. As described above, the wider the pH adjustment window, the easier the process can be controlled on an industrial scale.

[Fixing window]
Each toner composition was printed on 24 # hammer mill laser paper (HMLP) using a robot fixing to 50 pages per minute (ppm) with a toner coverage of 1.1 mg / cm ² . As shown in Tables 3 and 4 below, various fixing temperatures were used. The temperatures shown in Tables 3 and 4 are the heating element / heater temperatures of the fusion robot. Various fixing grades were measured for each toner composition. These fixing grade measurements include the scratch resistance test shown in FIG. 3 and the conventional 60 degree gloss test shown in Table 4. In the scratch resistance test, the printed samples were evaluated using a Taber friction tester sold by Taber Industries, North Tanawanda, New York. The printed samples were evaluated according to the Taber Friction Tester scale 0 to 10 (10 indicates the most scratch resistant). The Taber Friction Tester performs the process of scratching the printed sample multiple times with different forces until the printed toner is scraped from the sample. The part where the toner is scraped corresponds to the evaluation of the scale of the Taber friction tester from 0 to 10. As is known in the art, the conventional 60 degree gloss test irradiates the surface of a printed sheet with a known amount of light at an angle of 60 degrees and measures its reflectivity. A higher gloss test value indicates that more energy was transferred to the substrate as light passed through the fuser. The gloss of printing is also related to the resin and release agent used in the toner.

  As shown in Table 3, in Example toners A and B containing a borax coupling agent and using the same resin as Comparative toners I to III, conventional emulsion aggregation toner (Comparative toner I) and zinc sulfate Alternatively, excellent fixing performance was obtained as compared with toners having a coupling agent of aluminum sulfate (Comparative Example Toners II and III). The lower limit of the fixing windows of Example toners A and B is lower than the lower limit value of the fixing windows of Comparative Examples I to III. Specifically, Example toners A and B have acceptable scratch resistance at low temperatures of 200 ° C. and 195 ° C., respectively. Comparative toners I-III exhibited a cold offset (“CO”), meaning that the toner could not provide acceptable scratch resistance at that temperature, and that the toner was not fixed to the paper. As described above, the toners A and B of the example require less energy to achieve an acceptable fixing operation than the toners I to III of the comparative examples. The comparative toners A and B have improved scratch resistance compared to the comparative toners I to III even at a temperature increased to 210 ° C. to 230 ° C.

  The cores of Example toners C and D were formed using the same resin as Example toners A and B and Comparative toners I to III, but the shells of Example toners C and D were formed using different resins. . Nevertheless, as shown in Table 3, the lower limit of the fixing window of Example toners C and D containing the borax coupling agent was lower than the lower limit value of the fixing window of Comparative Examples I to III. In addition, the toners of Examples C and D have improved scratch resistance at a high temperature of 210 ° C. to 230 ° C. as compared with Comparative Examples Toners I to III.

  Example toner E was produced using a resin having a higher molecular weight and having a glass transition temperature higher than those used in Example toners A and B and Comparative toners I to III. One skilled in the art will appreciate that in such resins having a high molecular weight and a higher glass transition temperature, the lower limit of the fixing window is expected to be compromised. Table 3 shows that the toners of Examples A and B exceeded the performance of Example Toner E in that both the molecular weight and glass transition temperature of the resin used in Example Toner E were lower. However, the fixing performance of Example Toner E containing a borax coupling agent and a high molecular weight and high glass transition temperature resin is comparable, even though Comparative Toners I to III contain a low molecular weight and low glass transition temperature resin. Example It was comparable to the fixing performance of toners I to III.

  As shown in Table 4, the toners of Examples A to E exhibited gloss test performance comparable to that of Comparative Example Toner I. Comparative toners II and III exhibited lower gloss values than the toners of Examples A to E and Comparative Example Toner I.

  The foregoing description of some embodiments has been presented for purposes of illustration. These descriptions are all of the invention and are not intended to limit the disclosure to the precise form disclosed, and many modifications and variations are possible in light of the above teaching. It is clear that there is. It will be understood that the present invention may be practiced otherwise than as specifically described herein without departing from the scope of the present invention.

Claims (8)

A chemical toner composition comprising:
The first polymeric binders having a functional group, see containing a colorant and a releasing agent, a core having a surface,
A borax coupling agent located on the surface of the core;
A shell formed around the core and the borax coupling agent and including a second polymer binder having a functional group ;
The borax coupling agent is located between the core and the shell, and forms a hydrogen bond between the hydroxy group and the functional group of the first polymer binder and the second polymer binder. A chemical toner composition wherein a shell is bonded to the surface of the core and the core component of the toner is collected in the core prior to bonding the shell, thereby reducing residual particulates in the toner.   The chemical toner composition of claim 1, wherein each of the first polymer binder and the second polymer binder comprises a polyester resin.   The chemical toner composition of claim 2, wherein the first polymer binder comprises a first polyester resin or mixture, and the second polymer binder comprises a second polyester resin or mixture that is different from the first polyester resin or mixture. object.   The chemical toner composition of claim 1, wherein each of the first polymer binder and the second polymer binder comprises a styrene polymer.   5. The chemical toner of claim 4, wherein the first polymer binder comprises a first styrene polymer or mixture and the second polymer binder comprises a second styrene polymer or mixture that is different from the first styrene polymer or mixture. Composition. The weight ratio of the second polymeric binder of said first polymeric binder is between 2 0:80 or al 8 0:20, chemical toner composition of claim 1. The weight ratio of the second polymeric binder of the first polymeric binder is between 5 0:50 or al 8 0:20, chemical toner composition of claim 6.   The chemical toner composition of claim 1, wherein the core and the shell comprise the same polymer binder.