CN104024945B - Chemically prepared toner formulations containing borax coupling agent - Google Patents

Abstract

According to an exemplary embodiment, the method for producing toner and toner of chemical preparation includes：Core, it includes first polymer adhesive, colouring agent and releasing agent；Shell, it is formed on around the core and comprising second polymer adhesive；And borax coupling agent, it is between the core and the shell.

Description

Chemically prepared toner formulations containing borax coupling agent

Cross References to Related Applications

This patent application is related to the title "PROCESS FOR PREPARING TONERINCLUDING A BORAX COUPLING AGENT" filed on December 29, 2011 and assigned to the assignee of the present application. Associated with U.S. Patent Application Serial No. 13/339,565 (Attorney Docket P7-US1).

background

1. Field of the Disclosure

The present invention relates generally to chemically prepared toners for use in electrophotography and more particularly to chemically prepared toners comprising a borax coupling agent.

2. Description of related technologies

Toners used in electrophotographic printers include two main types, mechanically ground toners and chemically prepared toners (CPT). Chemically prepared toners offer distinct advantages over mechanically ground toners, including better print quality, higher toner transfer efficiency, and use in various components of electrophotographic printers such as Lower torque properties of developer rollers, fuser belts, and charge rollers. The particle size distribution of CPT is generally narrower than that of mechanically milled toner. The size and shape of CPT are also easier to control than mechanically ground toners.

There are several known types of CPT, which include suspension polymerization toners (SPT), emulsion aggregation (emulsion aggregation) toners (EAT)/latex aggregation toners (LAT), preformed polymers in solvents (DPPT) ) as well as "chemically milled" toners. Although emulsion agglomeration toners require a more complex process than other CPTs, the resulting toners have a relatively narrow size distribution. Emulsion agglomerated toners can also be manufactured with smaller particle sizes allowing for improved print resolution. The emulsion aggregation method also allows better control over the shape and structure of the toner particles, which allows them to be tailored to meet the desired cleaning, scraping, and transfer characteristics. The shape of the toner particles can be optimized to ensure proper and effective removal of toner from various electrophotographic printer components such as developer rollers, charge rollers, and doctor blades in order to prevent toner from filming or Unwanted deposits.

In the usual method for preparing EAT, emulsion aggregation is carried out in an aqueous system, which results in good control of both the size and shape of the toner particles. Toner components typically include a polymeric binder, one or more colorants, and a release agent. Styrene-acrylic copolymer polymer binders are commonly used as latex binders in emulsion aggregation processes. However, the use of styrene-acrylic copolymer latex binders requires a trade-off between the fusing properties of the toner and its shipping and storage properties. The fusing properties of a toner include its fusing window. The fusing window is the temperature range at which fusing occurs satisfactorily without incomplete fusing and without transferring toner to a heating element, which may be a roller, belt, or other element that contacts toner during fusing . Thus, below the lower limit of the fusion window the toner is incompletely fused, and above the upper limit of the fusion window the toner flows onto the fusing member where it damages the sheet that is subsequently fused. It is preferred that the lower limit of the fusion window be as low as possible to reduce the temperature required for the fuser in an electrophotographic printer to improve printer safety and save energy. However, the toner must also be able to survive the extremes of temperature and humidity associated with storage and transport without clumping or clogging that could lead to printing defects. Therefore, the lower limit of the fusing window cannot be so low that the toner may melt during storage or transportation of the toner cartridge containing the toner.

Toners formed from polyester binder resins generally have better mechanical properties than toners formed from styrene-acrylic copolymer binders with similar melt viscosity characteristics. This makes them more durable and more resistant to filming of press components. Polyester toners also have better compatibility with colored pigments, which results in a wider color gamut. Until recently, polyester binder resins have often been used in the preparation of mechanically ground toners and have rarely been used in chemically prepared toners. Polyester binder resins are manufactured using polycondensation. Such methods are time consuming because they involve long polymerization cycles and thus limit the use of low to moderate molecular weight polyester binder resins to polyester polymers with limited fusing characteristics of the toner. In addition, polyester binder resins are difficult to disperse in aqueous systems due to their polar nature, pH sensitivity, and gel content, thereby limiting their applicability in emulsion aggregation methods.

However, with the advancement of toner manufacturing technology, it has become possible to obtain a stable emulsion using a polyester binder resin by first dissolving it in an organic solvent such as methyl ethyl ketone ( MEK), dichloromethane, ethyl acetate, or tetrahydrofuran (THF), and then undergo a phase inversion process in which water is slowly added to the organic solvent. The organic solvent is then evaporated to allow the polyester binder resin to form a stable emulsion. U.S. Patent No. 7,939,236, entitled "Chemically Prepared Toners and Processes Therefor," assigned to the assignee of the present application and incorporated herein by reference in its entirety, teaches methods for using organic solvents to A similar approach to obtain stable emulsions. These advances have allowed the use of polyester binder resins to form emulsion agglomerated toners. For example, U.S. Patent No. 7,923,191, entitled "Polyester Resins Produced by Emulsion Aggregation," and entitled "Emulsion Aggregation Toner Formulations," are assigned to the assignee of the present application and are incorporated herein by reference in their entirety. U.S. Patent Application Serial No. 12/206,402," discloses a method for preparing emulsion agglomerated toners using polyester binder resins.

These techniques offer the ability to produce emulsion aggregated toners with excellent fusibility; however, there are still problems involving low molecular weight resins, waxes, and surface migration of colorants. Migration of these components to the surface of the toner particles weakens the fusing properties and transport/storage properties of the toner and increases the occurrence of filming on printing press components. Accordingly, it will be appreciated that an emulsion aggregated toner formulation and method that reduces the migration of low molecular weight resins, waxes, and colorants to the surface of toner particles is desired. It is also desirable to minimize the total number of fine toner particles that can cause filming on printing press components.

overview

According to an exemplary embodiment, a chemically prepared toner composition includes: a core comprising a first polymer binder, a colorant, and a release agent; a shell formed around the core and comprising a second polymeric binder; and a borax coupling agent between the core and the shell.

Brief description of the drawings

The above and other features and advantages of the various embodiments, and the manner in which they are obtained, will be apparent and better understood by reference to the accompanying drawings.

FIG. 1 is an image of conventional emulsion aggregated toner particles taken using a scanning electron microscope.

FIG. 2 is an image of emulsion aggregated toner particles including a borax coupling agent between a core layer and a shell layer of the toner according to an exemplary embodiment.

3 is a graph depicting the pH adjustment window of an emulsion aggregation toner including a borax coupling agent between a core layer and a shell layer of the toner according to an exemplary embodiment, as compared with a conventional emulsion aggregation toner , the conventional emulsion aggregation toner is a toner comprising a zinc sulfate coupling agent and a toner comprising an aluminum sulfate coupling agent.

A detailed description

The following description and the accompanying drawings sufficiently illustrate the embodiments to enable those skilled in the art to practice the invention. It is to be understood that the present disclosure is not limited to the details of the arrangement and construction of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. For example, other embodiments may incorporate structural, sequential methods, and other variations. The embodiments merely represent possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may be altered. Portions and features of certain embodiments may be included in, or substituted for, those of others. The scope of this application includes the appended claims and all available equivalents. The following description is therefore not to be read narrowly and the scope of the present invention is defined by the appended claims. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the terms listed thereafter and equivalents thereof as well as additional terms.

The present disclosure relates to chemically prepared toners containing a borax coupling agent between the core and shell layers of the toner and related methods of emulsion aggregation preparation. The toner may be used in electrophotographic printers such as printers, copiers, multifunction devices, or all-in-one devices. The toner may be provided in a cartridge that supplies toner to the electrophotographic printer. Exemplary methods of forming toners using conventional emulsion aggregation techniques can be found in US Patent Nos. 6,531,254 and 6,531,256, which are hereby incorporated by reference in their entirety.

In the present emulsion aggregation method, toner fine particles are provided by a chemical method as opposed to a physical method such as pulverization. Typically, toners comprise one or more polymeric binders, release agents, colorants, borax coupling agents, and one or more optional additives such as charge regulator agents (CCAs). The emulsion of the polymeric binder is formed in water optionally with an organic solvent, with an inorganic base such as sodium hydroxide, potassium hydroxide, ammonium hydroxide, or an organic amine compound. Stabilizers containing anionic functional groups (A-) such as anionic surfactants or anionic polymer dispersants may also be included. It will be appreciated that cationic functional groups (C+) such as cationic surfactants or cationic polymeric dispersants may be replaced as desired. The polymer latex is used at two points during the toner formation process. A first part of the polymer latex is used to form the core of the produced toner particles and a second part of the polymer latex is used to form a shell around the toner core. The polymer latexes of the first part and the second part may be formed separately or together. In the case where the polymer latex portions forming the toner core and the toner shell are formed separately, the same or different polymer binders may be used. The ratio of the amount of polymeric binder in the toner core to the amount in the toner shell is between about 20:80 by weight and about 80:20 by weight, including all values therebetween And increments, such as between about 50:50 (by weight) and about 80:20 (by weight), depending on the particular resin used.

In the presence of a stabilizer having functional groups (and ionic charge) similar to those utilized in the polymer latex, the colorant, release agent, and optionally CCA are dispersed separately in their own in an aqueous environment or dispersed in an aqueous mixture. The polymer latex forming the toner core, the release agent dispersion, the colorant dispersion and optionally the CCA dispersion are then mixed and stirred to ensure a homogeneous composition. The term dispersion as used herein refers to a system in which microparticles are dispersed in a continuous phase having different compositions (or states) and may include emulsions. Acid is then added to lower the pH and cause flocculation. Flocculation refers to the process by which destabilized particles agglomerate (due to, for example, the presence of available counterions) into relatively larger aggregates. In this case, flocculation involves the formation of a gel in which the resin, colorant, release agent, and CCA form an aggregated mixture, typically particles ranging in size from 1 micrometer (μm) to 2 micrometers (μm). Unless otherwise stated, particle size references herein refer to the largest cross-sectional dimension of the particle. The aggregated toner particles can then be heated to a temperature below or near the glass transition temperature (Tg) of the polymer latex (e.g., ±5° C.) to induce Aggregate the growth of particle clusters. Once the aggregated particles have reached the desired size of the toner core, borax coupling agent is added so that it forms on the surface of the toner core. After adding the borax coupling agent, the polymer latex that forms the toner shell is added. Such polymer latex gathers around the toner core to form a toner shell. Once the aggregated particles reach the desired toner size, a base can be added to increase the pH and reionize the anionic stabilizer to prevent further particle growth or additional anionic stabilizer can be added. The temperature is then raised above the glass transition temperature of the polymer latex to fuse the particles within each cluster together. This temperature is maintained until the particles achieve the desired circularity. The toner particles are then washed and dried.

The toner particles produced may have an average particle diameter (volume average particle diameter) between about 3 μm and about 20 μm, such as between about 4 μm and about 15 μm, or more particularly between Between about 5 μm and about 7 μm. The toner particles produced can have an average circularity between about 0.90 and 1.00, including all values and increments therebetween, such as about 0.93 to about 0.98. The average circularity and average particle diameter can be measured by a Sysmex Flow Particle Image Analyzer (for example, FPIA-3000) available from Malvern Instruments.

Various components of the emulsion aggregation method used to prepare the above-mentioned toner will be described below. It should be noted that the various characteristics of the components shown can all be adjusted to facilitate the steps of agglomeration and formation of toner particles having a desired size and geometry. It is thus understood that by manipulating the characteristics shown, relatively stable dispersions can be formed in the first place where polymerization can be followed by relatively easily controlled final toner particle sizes for use in electrophotographic printers or printer cartridges. conduct.

polymer binder

As noted above, the toner herein includes one or more polymeric binders. The terms resin and polymer are used interchangeably herein as there is no technical difference between the two. In one embodiment, the polymeric binder includes polyester. The polyester binder may include a semi-crystalline polyester binder, a crystalline polyester binder, or an amorphous polyester binder. Alternatively, the polyester binder may comprise a polyester copolymer binder resin. For example, polyester binders may include styrene/acrylic-polyester graft copolymers. Polyester binders can be formed using acid monomers such as terephthalic acid, trimellitic anhydride, dodecenyl succinic anhydride, and fumaric acid. Additionally, polyester binders can be formed using alcohol monomers, such as ethoxylated bisphenol A and propoxylated bisphenol A. Exemplary polyester resins include, but are not limited to, T100 polyester resin, TF-104 polyester resin, NE-1582 polyester resin, NE-701 polyester resin, NE-701 polyester resin from Kao Corporation, Bunka Sumida-ku, Tokyo, Japan. 2141 polyester resin, NE-1569 polyester resin, Binder C polyester resin, FPESL-2 polyester resin, W-85N polyester resin, TL-17 polyester resin, TPESL-10 polyester resin, TPESL-11 poly Ester resins or mixtures thereof.

In other embodiments, polymeric binders include: thermoplastic type polymers such as styrene and/or substituted styrene polymers such as homopolymers (e.g. polystyrene) and/or copolymers (e.g. , styrene-butadiene copolymer and/or styrene-acrylic acid copolymer, styrene-butyl methacrylate copolymer and/or styrene-butyl acrylate and other acrylic monomers such as hydroxyacrylate or methyl polyvinyl acetate; polyolefin; poly(vinyl chloride); polyurethane; polyamide, silicone, epoxy, or phenolic resin.

As discussed above, in certain embodiments, the toner core may be formed from one polymeric binder (or blend) while the toner shell is formed from another polymeric binder (or blend) . In addition, the ratio of the amount of polymer binder in the toner core to the amount of toner in the toner shell may be between about 20:80 (by weight) and about 80:20 (by weight) or More particularly between about 50:50 (by weight) and about 80:20 (by weight), including all values and increments therebetween. The total polymeric binder may be provided in the range of about 70% to about 95% by weight of the final toner formulation, including all values and increments therebetween.

Borax coupling agent

The coupling agent used herein is borax (also known as sodium borate, sodium tetraborate, or disodium tetraborate). The term coupling agent as used herein refers to a compound having cross-linking ability to bond two or more components together. Typically, coupling agents have multivalent bonding capabilities. Borax differs from commonly used permanent coupling agents such as polyvalent metal ions (eg, aluminum and zinc) because its bonding is reversible. In electrophotographic processes, toners are preferred to have a low fusing temperature to save energy and to have a low melt viscosity ("soft") to allow high speed printing at low fusing temperatures. However, to maintain the stability of the toner during shipping and storage and to prevent filming of printing press components, the toner is preferably "harder" at temperatures below the fusing temperature. Borax provides crosslinking through hydrogen bonding between its hydroxyl groups and the functional groups of the molecules to which it is bonded. Hydrogen bonding is sensitive to temperature and pressure and is not a stable and permanent bond. For example, when temperature is raised to a certain extent or pressure is applied to a polymer, the bonds will partially or completely break, causing the polymer to "flow" or tear. The reversibility of the bond formed by the borax coupling agent is particularly useful in toners as it allows "soft" toners at fusing temperature but "hard" toners at storage temperature agent.

It has also been observed that borax unexpectedly causes fine particles to aggregate on larger particles. Therefore, borax is particularly suitable as a coupling agent between the toner core and shell because it aggregates the components of the toner core to the core particles before the shell is added, thereby reducing residual fines in the toner. particle. This in turn reduces the amount of acid required in the coalescence stage and narrows the particle size distribution of the toner.

Borax also acts as a good buffer in the toner forming reaction due to the balance formed by the boric acid and the conjugate base. The presence of borax made the reaction more tolerant to pH changes and widened the pH adjustment window of the reaction compared to the conventional emulsion aggregation method. The pH adjustment window is critical for controlling particle size in an industrial scale-up process. For wider windows, the method is more manageable on an industrial scale.

The amount of borax coupling agent used herein can be varied. The borax coupling agent in the toner may be provided between about 0.1% and about 5.0% by weight of the total polymer binder, including all values and increments therebetween, such as between about 0.1% and about 1.0% or Between about 0.1% and about 0.5%. If too much coupling agent is used, its bond may not be completely broken at high fusion temperature. On the other hand, if too little coupling agent is used, it may fail to provide the desired bonding and buffering.

Colorant

Colorants are components that give color or other visual effects to toners and may include carbon black, dyes (which are soluble in a given medium and capable of settling), pigments (which are soluble in a given medium) or Composition of both. Colorant dispersions can be prepared by mixing pigments and dispersants in water. Alternatively, self-dispersing colorants may be used, allowing dispersants to be omitted. The colorant may be present in the dispersion at a level of from about 5% to about 20% by weight, including all values and increments therebetween. For example, the colorant may be present in the dispersion at a level of from about 10% to about 15% by weight. Dispersions of colorant may comprise particles of a size from about 50 nanometers (nm) to about 500 nm, including all values and increments therebetween. Additionally, the colorant dispersion may have a weight percent pigment divided by weight percent dispersant (P/D ratio) of from about 1:1 to about 8:1, such as from about 2:1 to about 5:1, including all values therebetween. and increment. The colorant may be present at less than or equal to about 15% by weight of the final toner formulation, including all values and increments therebetween.

Release agent

Release agents can include any compound that facilitates the release of toner from components (eg, from the surface of a roller) in an electrophotographic printer. For example, the release agent may include polyolefin wax, ester wax, polyester wax, polyethylene wax, metal salt of fatty acid, fatty acid ester, partially saponified fatty acid ester, higher fatty acid ester, higher alcohol, paraffin, Gallo waxes, amide waxes and polyol esters.

Release agents may thus include low molecular weight (eg, Mn≦10,000) hydrocarbon-based polymers having a melting point below about 140°C, inclusive of all values and increments between about 50°C and about 140°C. For example, the release agent may have a melting point of about 60°C to about 135°C, or from about 65°C to 100°C, or the like. The mold release agent may be present in the dispersion in an amount from about 5% to about 35% by weight, including all values and increments therebetween. For example, the mold release agent may be present in the dispersion in an amount from about 10% to about 18% by weight. The dispersion of release agent may also comprise particles of a size from about 50 nm to about 1 μm, including all values and increments therebetween. Additionally, the release agent dispersion can be further characterized as having a weight percent release agent divided by weight percent dispersant (RA/D ratio) of from about 1:1 to about 30:1. For example, the RA/D ratio can be from about 3:1 to about 8:1. The release agent may be provided in the range of about 2% to about 20% by weight of the final toner formulation, including all values and increments therebetween.

Surfactants/Dispersants

Surfactants, polymeric dispersants or combinations thereof may be used. A polymeric dispersant can generally comprise three components, namely, a hydrophilic component, a hydrophobic component, and a protective colloid component. References to hydrophobicity refer to relatively non-polar types of chemical structures that tend to self-associate in the presence of water. The hydrophobic component of the polymeric dispersant may include electron rich functional groups or long chain hydrocarbons. Such functional groups are known to exhibit strong interaction and/or adsorption properties to the surface of particulates, such as colorants and polyester binder resins of polyester resin emulsions. Hydrophilic functional groups refer to relatively polar functional groups (eg, anionic groups) that may then tend to associate with water molecules. The protective colloid component includes water-soluble groups without ionic functions. In aqueous systems, the protective colloid component of the polymeric dispersant provides additional stability in addition to the hydrophilic component. The use of a protective colloid component in the polymeric dispersant substantially reduces the amount of ionic monomer moiety or hydrophilic component. In addition, the protective colloid component stabilizes the polymeric dispersant in less acidic media. The protective colloid component typically includes polyethylene glycol (PEG) groups. Dispersants utilized herein may include those disclosed in US Pat. No. 6,991,884 and US Pat. No. 5,714,538, which are hereby incorporated by reference in their entirety.

The surfactant as used herein may be a commonly used surfactant known in the art for dispersing non-self-dispersing colorants and release agents used in the preparation of Toner preparations for electrophotography. Commercial surfactants such as the AKYPO carboxylic acid series of AKYPO from Kao Corporation, Bunka Sumida-ku, Tokyo, Japan can be used. For example, alkyl ether carboxylate (salt) and alkyl ether sulfate (salt), preferably lauryl ether carboxylate (salt) and lauryl ether sulfate (salt) can be used, respectively. A particularly suitable anionic surfactant is AKYPO RLM-100, available from Kao Corporation, Bunka Sumida-ku, Tokyo, Japan, which is laureth-11 carboxylic acid, thereby providing anionic carboxylate (ester) functional groups . Other anionic surfactants contemplated herein include alkyl phosphates, alkyl sulfonates, and alkylbenzene sulfonates. Sulfonic acids containing polymers or surfactants may also be utilized.

optional additives

The toner formulations of the present disclosure may also contain one or more commonly used charge modifiers, which may optionally be used in the preparation of the toner formulations. A charge regulator can be understood as a compound that contributes to the generation and stabilization of tribocharge in the toner. Charge modifiers also help prevent degradation of the charging characteristics of toner formulations. The charge modifier can be prepared in the form of a dispersion in a manner similar to that discussed above for the colorant dispersion and release agent dispersion.

The toner formulation may contain one or more additional additives, such as acids and/or bases, emulsifiers, UV absorbers, fluorescent additives, pearlescent additives, plasticizers, and combinations thereof. These additives can be expected to enhance the characteristics of images printed using the present toner formulations. For example, UV absorbers may be included to increase UV photofading resistance by preventing the image from gradually fading upon subsequent exposure to UV radiation. Suitable examples of UV absorbers include, but are not limited to, benzophenones, benzotriazoles, acetanilides, triazines, and derivatives thereof. Commercially available plasticizers known in the art may also be used to adjust the coalescence temperature of the toner formulation.

The following examples are provided to further clarify the idea of the present disclosure, but not to limit the scope of the present disclosure.

Example

Examples Magenta Pigment Dispersion

About 10 g of AKYPO RLM-100 polyoxyethylene (10) lauryl ether carboxylic acid from Kao Corporation, Bunka Sumida-ku, Tokyo, Japan was combined with about 350 g of deionized water and the pH was adjusted using sodium hydroxide to ~7-9. About 10 g of Solsperse 27000 from Lubrizol Advanced Materials, Cleveland, Ohio, USA was added and the dispersant and water mixture was blended with an electric mixer, then 100 g of Red 122 pigment was added relatively slowly. Once the pigment is fully wetted and dispersed, the mixture is added to a horizontal media mill to reduce particle size. The solution was processed in a media mill until the particle size was about 200 nm. The final pigment dispersion is designed to contain from about 20% to about 25% solids by weight.

Example Cyan Pigment Dispersion

About 10 g of AKYPO RLM-100 polyoxyethylene (10) lauryl ether carboxylic acid from Kao Corporation, Bunka Sumida-ku, Tokyo, Japan was combined with about 350 g of deionized water and the pH was adjusted using sodium hydroxide to ~7-9. About 10 g of Solsperse 27000 from Lubrizol Advanced Materials, Cleveland, Ohio, USA was added and the dispersant and water mixture was blended with an electric mixer, then 100 g of Pigment Blue 15:3 was added relatively slowly. Once the pigment is fully wetted and dispersed, the mixture is added to a horizontal media mill to reduce particle size. The solution was processed in a media mill until the particle size was about 200 nm. The final pigment dispersion is designed to contain from about 20% to about 25% solids by weight.

Example wax emulsion

About 12 g of AKYPO RLM-100 polyoxyethylene (10) lauryl ether carboxylic acid from Kao Corporation, Bunka Sumida-ku, Tokyo, Japan was combined with about 325 g of deionized water and the pH was adjusted using sodium hydroxide to ~7-9. The mixture was then processed through a microfluidizer and heated to about 90°C. About 60 g of polyethylene wax from Petrolite, Corp., Westlake, Ohio, USA was added slowly while the temperature was maintained at about 90°C for about 15 minutes. When the particle size is below about 300 nm, the emulsion is then removed from the microfluidization device. The solution was then stirred at room temperature. The wax emulsion is configured to contain from about 10% to about 18% solids by weight.

Example polyester resin emulsion A

A hybrid polyester resin having a maximum molecular weight of about 9,000, 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), where, in this case, once the baseline (heat capacity) shift occurs, thus indicating that Tg can occur at a heating rate of about 5 per minute At about 53°C to about 58°C. The acid number may be due to the presence of one or more free carboxylic acid functional groups (-COOH) in the polyester. Acid value refers to the mass of potassium hydroxide (KOH) in milligrams required to neutralize one gram of polyester. The acid number is thus a measure of the number of carboxylic acid groups in the polyester.

150 g of mixed polyester resin was dissolved in 450 g of methyl ethyl ketone (MEK) with stirring in a round bottom flask. The dissolved resin was then poured into a beaker. The beaker was placed directly in the ice bath under the homogenizer. The homogenizer was turned on at high shear and 10 g of a 10% potassium hydroxide (KOH) solution and 500 g of deionized water were immediately added to the beaker. The homogenizer was run at high shear 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 between about 22 inches of mercury and about 23 inches of mercury. About 500 mL of additional deionized water was added to the reactor and the temperature was gradually raised to about 70°C to ensure that substantially all of the MEK was distilled off. The heat source to the reactor was then turned off and the mixture was stirred until it reached room temperature. Once the reactor reached room temperature, the vacuum was turned off and the resin solution was removed and placed in a storage bottle.

The particle size of the resin emulsion was between about 185 nm and about 235 nm (volume average) as measured by a NANOTRAC particle size analyzer. The pH of the resin solution is between about 6.5 and about 7.0.

Example polyester resin emulsion B

Except for the use of 8 g of 10% potassium hydroxide (KOH) solution, has a maximum molecular weight of about 11,000, a glass transition temperature of about 55°C to about 60°C, a melting temperature of about 110°C, and a temperature of about 15 to about 20 Acid value polyester resins were used to form emulsions using the procedure described in Example Polyester Resin A.

The particle size of the resin emulsion was between about 195 nm and about 235 nm (volume average) as measured by a NANOTRAC particle size analyzer. The pH of the resin solution is between about 6.7 and about 7.2.

Example polyester resin emulsion C

Except for the use of 7 g of 10% potassium hydroxide (KOH) solution, has a maximum molecular weight of about 11,000, a glass transition temperature of about 55°C to about 58°C, a melting temperature of about 115°C, and a temperature of about 8 to about 13 Acid value polyester resins were used to form emulsions using the procedure described in Example Polyester Resin A.

The particle size of the resin emulsion was between about 190 nm and about 240 nm (volume average) as measured by a NANOTRAC particle size analyzer. The pH of the resin solution is between about 7.5 and about 8.2.

Examples of toner formulations

Comparative Example Toner I

Comparative Example Toner I was prepared using a conventional emulsion aggregation method and contained no borax coupling agent. The emulsion aggregation CPT used in this embodiment is an acid aggregation with a pH reversal used to terminate the growth of toner particles. The components were added to a 2.5 liter reactor in the following relative proportions: 88.2 parts (by weight polyester) of Example polyester resin emulsion A, 6.8 parts (by weight of pigment) of Example magenta pigment dispersion Body and 5 parts (release agent by weight) of the embodiment wax emulsion. Deionized water was then added so that the mixture contained about 12.5% solids by weight.

The mixture was heated to 30°C in the reactor and a circulation loop consisting of a high shear mixer and acid addition pump was started. The mixture was sent through a loop and the high shear mixer was set at 10,000 revolutions per minute (rpm). The acid is slowly added to the high shear mixer to disperse the acid evenly in the toner mixture so that there are no low pH depressions. The acid addition took about 4 minutes using 306 g of 1% sulfuric acid solution. The flow of the loop is then reversed to return the toner mixture to the reactor. The reactor temperature was raised to about 50°C to allow particle growth. The temperature is maintained at around 50° C. until the particles reach the desired size (number average size of about 5 μm to about 6 μm and volume average size of about 6 μm to about 7 μm). Once the particles reached their desired size, 4% NaOH was added to raise the pH to 6.00 to stop particle growth. The reaction was held at about 50°C for about 1 hour and then the temperature was raised to 91°C to induce coalescence of the particles. The microparticles were maintained at 91°C until the microparticles reached the desired circularity (about 0.97). The toner is then washed and dried.

The dried toner had a volume average particle diameter of 6.0 μm as measured by a COULTER COUNTER Multisizer3 analyzer. Fine particles (<2 μm) were present at 4.16% by number and the toner had a circularity of 0.970, both analyzed by SYSMEX FPIA-3000 particle characterization manufactured by Malvern Instruments, Ltd., Malvern, Worcestershire UK instrument to measure. The amount of fines in Comparative Example Toner 1 is consistent with other emulsion aggregation polyester toners that do not contain borax coupling agent, and that other emulsion aggregation polyester toners have The number of fine particles between.

Additional toners were made using the recipe and procedure from Comparative Example Toner 1, except that the neutralizing pH was varied to test the pH adjustment window. The results for these toners are shown in Table 2 below.

Example Toner A

EXAMPLES Polyester resin emulsion A was divided into two batches 70:30 by weight to form the core and shell of the toner, respectively. The total polyester content represents about 87.7% of the total toner solids. Thus, the first batch contained 61.4% total toner solids and the second batch contained 26.3% total toner solids. The components were added to a 2.5 liter reactor in the following percentages: Example magenta pigment dispersion with 61.4 parts (by weight polyester), 6.8 parts (by weight pigment) and 5 parts (by weight The first example of wax emulsion polyester resin emulsion A. Deionized water was then added so that the mixture contained about 12% to about 15% solids by weight.

The mixture was heated to 30°C in the reactor and a circulation loop consisting of a high shear mixer and acid addition pump was started. The mixture was sent through a loop and the high shear mixer was set at 10,000 rpm. The acid is slowly added to the high shear mixer to evenly disperse the acid in the toner mixture so that there are no low pH depressions. The acid addition took about 4 minutes using 200 g of a 1% sulfuric acid solution. The flow of the loop is then reversed to return the toner mixture to the reactor and the reactor temperature is raised to about 40°C-45°C. Once the particle size reached 4.0 [mu]m (number average), a 5% by weight solution of borax (30 g of a solution containing 1.5 g of borax) was added. The borax content represents about 0.5% by weight of total toner solids. After the borax addition, a second batch of Example Polyester Resin Emulsion A containing 26.3 parts by weight polyester was added. The mixture was stirred for about 5 minutes and the pH was monitored. Once the particle size reached 5.5 μm (number average), 4% NaOH was added to raise the pH to about 5.95 to stop particle growth. The reaction temperature was maintained for one hour. Particle size is monitored during this period. Once particle growth ceased, the temperature was raised to 88°C to induce particle coalescence. This temperature was maintained until the particles reached their desired circularity (about 0.97). The toner is then washed and dried.

The dried toner had a volume average particle diameter of 6.65 μm and a number average particle diameter of 5.49 μm. Fine particles (<2 μm) were present at 0.11% by number and the toner had a circularity of 0.978.

Additional toners were made using the recipe and procedure from Example Toner A, except that the neutralizing pH was varied to test the pH adjustment window. The results for these toners are shown in Table 2 below.

Example Toner B

EXAMPLES Polyester resin emulsion A was divided into two batches 60:40 by weight to form the core and shell of the toner, respectively. The total polyester content represents about 87.9% of the total toner solids. Thus, the first batch contained 52.7% total toner solids and the second batch contained 35.2% total toner solids. The components were added to a 2.5 liter reactor in the following percentages: Example magenta pigment dispersion with 52.7 parts (by weight polyester), 6.8 parts (by weight pigment) and 5 parts (by weight The first example of wax emulsion polyester resin emulsion A. Deionized water was then added so that the mixture contained about 12% to about 15% solids by weight.

The mixture was heated to 30°C in the reactor and a circulation loop consisting of a high shear mixer and acid addition pump was started. The mixture was sent through a loop and the high shear mixer was set at 10,000 rpm. The acid is slowly added to the high shear mixer to disperse the acid evenly in the toner mixture so that there are no low pH depressions. The acid addition took about 4 minutes using 150 g of a 1% sulfuric acid solution. The flow of the loop is then reversed to return the toner mixture to the reactor and the reactor temperature is increased to about 40°C-45°C. Once the particle size reached 4.0 μm (number average), a 5% borax solution (15 g of a solution containing 0.75 g of borax) was added. The borax content represented about 0.3% by weight of total toner solids. After the borax addition, a second batch of Example Polyester Resin Emulsion A containing 35.2 parts by weight polyester was added. The mixture was stirred for about 5 minutes and the pH was monitored. Once the particle size reached 5.5 μm (number average), 4% NaOH was added to raise the pH to about 5.95 to stop particle growth. The reaction temperature was maintained for one hour. Particle size is monitored during this period. Once particle growth ceased, the temperature was increased to 88°C to induce particle coalescence. This temperature was maintained until the particles reached their desired circularity (about 0.97). The toner is then washed and dried.

The dried toner had a volume average particle diameter of 6.24 μm and a number average particle diameter of 5.48 μm. Fine particles (<2 μm) were present at 0.09% by number and the toner had a circularity of 0.983.

Example Toner C

The compositions of Example polyester resin emulsion A and Example polyester resin emulsion C were used in a ratio of 70:30 by weight to form the core and shell of the toner, respectively. The total polyester content represents about 87.9% of the total toner solids. Accordingly, Example Polyester Resin Emulsion A contained 61.5% of total toner solids and Example Polyester Resin Emulsion C contained 26.4% of total toner solids. The components were added to a 2.5 liter reactor in the following percentages: Example Magenta Pigment Dispersion with 61.5 parts (by weight polyester), 6.8 parts (by weight pigment) and 5 parts (by weight Example of release agent) Example of wax emulsion Example of polyester resin emulsion A. Deionized water was then added so that the mixture contained about 12% to about 15% solids by weight.

The mixture was heated to 30°C in the reactor and a circulation loop consisting of a high shear mixer and acid addition pump was started. The mixture was sent through a loop and the high shear mixer was set at 10,000 rpm. The acid is slowly added to the high shear mixer to evenly disperse the acid in the toner mixture so that there are no low pH depressions. The acid addition took about 4 minutes using 200 g of a 1% sulfuric acid solution. The flow of the loop is then reversed to return the toner mixture to the reactor and the reactor temperature is increased to about 37°C-42°C. Once the particle size reached 4.0 [mu]m (number average), a 5% by weight solution of borax (15 g of a solution containing 0.75 g of borax) was added. The borax content represented about 0.25% by weight of total toner solids. After the borax addition, Example polyester resin emulsion C containing 26.4 parts by weight polyester was added. The mixture was stirred for about 5 minutes and the pH was monitored. Once the particle size reached 5.5 μm (number average), 4% NaOH was added to raise the pH to about 6.60 to stop particle growth. The reaction temperature was maintained for one hour. Particle size is monitored during this period. Once particle growth ceased, the temperature was raised to 88°C to induce particle coalescence. This temperature was maintained until the particles reached their desired circularity (about 0.97). The toner is then washed and dried.

The dried toner had a volume average particle diameter of 6.40 μm and a number average particle diameter of 5.18 μm. Fine particles (<2 μm) were present at 0.92% by number and the toner had a circularity of 0.970.

Example Toner D

EXAMPLES A composition of polyester resin emulsion A and an emulsion of ACT-004 polyester resin purchased from Toyobo Co., Ltd., Kita-ku, Osaka, Japan was used in a ratio of 70:30 by weight to form The core and shell of the toner. ACT-004 polyester resin has a maximum 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 number of about 16. The particle size of the emulsion is about 200 nm (volume average). The total polyester content represents about 87.9% of the total toner solids. Thus, Example polyester resin emulsion A contained 61.5% of total toner solids and the ACT-004 polyester emulsion contained 26.4% of total toner solids. The components were added to a 2.5 liter reactor in the following percentages: Example Magenta Pigment Dispersion with 61.5 parts (by weight polyester), 6.8 parts (by weight pigment) and 5 parts (by weight Example of release agent) Example of wax emulsion Example of polyester resin emulsion A. Deionized water was then added so that the mixture contained about 12% to about 15% solids by weight.

The mixture was heated to 30°C in the reactor and a circulation loop consisting of a high shear mixer and acid addition pump was started. The mixture was sent through a loop and the high shear mixer was set at 10,000 rpm. The acid is slowly added to the high shear mixer to disperse the acid evenly in the toner mixture so that there are no low pH depressions. The acid addition took about 4 minutes using 200 g of a 1% sulfuric acid solution. The flow of the loop is then reversed to return the toner mixture to the reactor and the reactor temperature is raised to about 35°C-40°C. Once the particle size reached 4.0 [mu]m (number average), a 5% by weight borax solution (15 g of a solution containing 0.75 g of borax) was added. The borax content represented about 0.25% by weight of total toner solids. After the borax addition, an ACT-004 polyester resin emulsion containing 26.4 parts by weight polyester was added. The mixture was stirred for about 5 minutes and the pH was monitored. Once the particle size reached 5.5 μm (number average), 4% NaOH was added to raise the pH to about 6.20 to stop particle growth. The reaction temperature was maintained for one hour. Particle size is monitored during this period. Once particle growth ceased, the temperature was raised to 88°C to induce particle coalescence. This temperature was maintained until the particles reached their desired circularity (about 0.97). The toner is then washed and dried.

The dried toner had a volume average particle diameter of 6.18 μm and a number average particle diameter of 5.28 μm. Fine particles (<2 μm) were present at 0.42% by number and the toner had a circularity of 0.973.

Example Toner E

EXAMPLES Polyester resin emulsion B was divided into two batches 70:30 by weight to form the core and shell of the toner, respectively. The total polyester content represents about 87.9% of the total toner solids. Thus, the first batch contained 61.5% total toner solids and the second batch contained 26.4% total toner solids. The components were added to a 2.5 liter reactor in the following percentages: Example Magenta Pigment Dispersion with 61.5 parts (by weight polyester), 6.8 parts (by weight pigment) and 5 parts (by weight The first batch of examples of wax emulsion polyester resin emulsion B. Deionized water was then added so that the mixture contained about 12% to about 15% solids by weight.

The mixture was heated to 30°C in the reactor and a circulation loop consisting of a high shear mixer and acid addition pump was started. The mixture was sent through a loop and the high shear mixer was set at 10,000 rpm. The acid is slowly added to the high shear mixer to evenly disperse the acid in the toner mixture so that there are no low pH depressions. The acid addition took about 4 minutes using 200 g of a 1% sulfuric acid solution. The flow of the loop is then reversed to return the toner mixture to the reactor and the reactor temperature is raised to about 40°C-45°C. Once the particle size reached 5.0 [mu]m (number average), a 5% by weight solution of borax (15 g of a solution containing 0.75 g of borax) was added. The borax content represented about 0.25% by weight of total toner solids. After the borax addition, a second batch of Example polyester resin emulsion B containing 26.4 parts by weight polyester was added. The mixture was stirred for about 5 minutes and the pH was monitored. Once the particle size reached 5.5 μm (number average), 4% NaOH was added to raise the pH to about 7.10 to stop particle growth. The reaction temperature was maintained for one hour. Particle size is monitored during this period. Once particle growth ceased, the temperature was raised to 88°C to induce particle coalescence. This temperature was maintained until the particles reached their desired circularity (about 0.97). The toner is then washed and dried.

The dried toner had a volume average particle diameter of 7.24 μm and a number average particle diameter of 5.86 μm. Fine particles (<2 μm) were present at 1.76% by number and the toner had a circularity of 0.974.

Therefore, it can be seen that compared with the conventional emulsion aggregation method used to prepare the toner 1 of Comparative Example, the method used to prepare the toner particle containing the borax coupling agent between the core layer and the shell layer The emulsion aggregation method of Example Toners A to E significantly reduces the percentage of fine particles. Furthermore, Example Toners A to E each exhibited comparable average particle diameters and circularity relative to Comparative Example Toner I, as expected.

Test Results

surface migration

FIG. 1 shows an image of conventional emulsion aggregated toner particles 10 prepared according to Comparative Example I, taken using a scanning electron microscope (SEM). 2 shows an image of emulsion-aggregated toner particles 20 containing a borax coupling agent between the core and shell layers of the toner prepared according to Example A. As shown in FIG. As shown, toner particles 20 have a smoother, more uniform surface than conventional emulsion aggregated toner particles 10 . The smooth, uniform surface of the toner particles 20 reduces the occurrence of filming on the developer roller and improves toner fusing properties at higher temperatures. In contrast, toner particles 10 have significantly more colorant, release agent, and low-molecular-weight resin particles 12 that have migrated to their surfaces. As discussed above, borax unexpectedly causes these particles to accumulate on the toner core before the shell is added, which prevents them from migrating to the surface of the toner.

Developing roller filming and blade filming

The filming of Example Toners A and B and Comparative Example Toner I to the developer roller and blade was also tested. The toners are placed in the toner cartridges individually. Each cartridge was then inserted into the test machine and run at 50 ppm. Periodically, the developer roller and blade of each cartridge were visually inspected to assess the amount of toner filming on the assembly. The level of toner filming is rated on a scale of 1 to 4, with higher ratings (eg, 4) indicating more filming and poorer performance. The test results are shown in Table 1 below.

Table 1

As shown in Table 1, Example Toners A and B containing a borax coupling agent exhibit improved resistance to developer roll filming and comparable resistance to scratch blade filming compared to Comparative Example Toner I sex.

To further evaluate the performance of the borax coupling agent, additional Comparative Example toners were prepared using zinc sulfate coupling agent and aluminum sulfate coupling agent between the core and shell layers of the toner, respectively.

Comparative Example Toner II

Comparative Example Toner II was prepared using zinc sulfate coupling agent instead of borax coupling agent. EXAMPLES Polyester resin emulsion A was divided into two batches 70:30 by weight to form the core and shell of the toner, respectively. The total polyester content represents about 90.3% of the total toner solids. Thus, the first batch contained 63.2% total toner solids and the second batch contained 27.1% total toner solids. Components were added to a 2.5 liter reactor in the following percentages: Example cyan pigment dispersion with 63.2 parts (by weight polyester), 4.4 parts (by weight pigment) and 5 parts (by weight The first batch of examples of wax emulsion polyester resin emulsion A. Deionized water was then added so that the mixture contained about 12% to about 15% solids by weight.

The mixture was heated to 30°C in the reactor and a circulation loop consisting of a high shear mixer and acid addition pump was started. The mixture was sent through a loop and the high shear mixer was set at 10,000 rpm. The acid is slowly added to the high shear mixer to disperse the acid evenly in the toner mixture so that there are no low pH depressions. The acid addition took about 4 minutes using 175 g of 1% sulfuric acid solution. The flow of the loop is then reversed to return the toner mixture to the reactor and the reactor temperature is raised to about 40°C-45°C. Once the particle size reached 4.0 [mu]m (number average), a 5% by weight solution of zinc sulfate (18 g of a solution containing 0.9 g of zinc sulfate) was added. The zinc sulfate content represents about 0.3% by weight of total toner solids. After the zinc sulfate addition, a second batch of Example Polyester Resin Emulsion A containing 27.1 parts by weight polyester was added. The mixture was stirred for about 5 minutes and the pH was monitored. Once the particle size reached 5.5 μm (number average), 4% NaOH was added to raise the pH to about 6.82 to stop particle growth. The reaction temperature was maintained for one hour. Particle size is monitored during this period. Once particle growth ceased, the temperature was raised to 88°C to induce particle coalescence. This temperature was maintained until the particles reached their desired circularity (about 0.97). The toner is then washed and dried.

The dried toner had a volume average particle diameter of 5.87 μm and a number average particle diameter of 4.98 μm. Fine particles (<2 μm) were present at 1.12% (by number) and the toner had a circularity of 0.972.

Additional toners were made using the recipe and procedure from Comparative Example Toner II, except that the neutralizing pH was varied to test the pH adjustment window. The results for these toners are shown in Table 2 below.

Comparative Example Toner III

Comparative Example Toner III was prepared using an aluminum sulfate coupling agent instead of a borax coupling agent. EXAMPLES Polyester resin emulsion A was divided into two batches 70:30 by weight to form the core and shell of the toner, respectively. The total polyester content represents about 90.3% of the total toner solids. Thus, the first batch contained 63.2% total toner solids and the second batch contained 27.1% total toner solids. Components were added to a 2.5 liter reactor in the following percentages: Example cyan pigment dispersion with 63.2 parts (by weight polyester), 4.4 parts (by weight pigment) and 5 parts (by weight The first batch of examples of wax emulsion polyester resin emulsion A. Deionized water was then added so that the mixture contained about 12% to about 15% solids by weight.

The mixture was heated to 30°C in the reactor and a circulation loop consisting of a high shear mixer and acid addition pump was started. The mixture was sent through a loop and the high shear mixer was set at 10,000 rpm. The acid is slowly added to the high shear mixer to disperse the acid evenly in the toner mixture so that there are no low pH depressions. The acid addition took about 4 minutes using 175 g of 1% sulfuric acid solution. The flow of the loop is then reversed to return the toner mixture to the reactor and the reactor temperature is raised to about 40°C-45°C. Once the particle size reached 4.0 [mu]m (number average), a 5% by weight solution of aluminum sulfate (18 g of a solution containing 0.9 g of aluminum sulfate) was added. The aluminum sulfate content represents about 0.3% by weight of total toner solids. After the aluminum sulfate addition, a second batch of Example Polyester Resin Emulsion A containing 27.1 parts by weight polyester was added. The mixture was stirred for about 5 minutes and the pH was monitored. Once the particle size reached 5.5 μm (number average), 4% NaOH was added to raise the pH to about 6.47 to stop particle growth. The reaction temperature was maintained for one hour. Particle size is monitored during this period. Once particle growth ceased, the temperature was raised to 88°C to induce particle coalescence. This temperature was maintained until the particles reached their desired circularity (about 0.97). The toner is then washed and dried.

The dried toner had a volume average particle diameter of 6.10 μm and a number average particle diameter of 5.20 μm. Fine particles (<2 μm) were present at 0.24% by number and the toner had a circularity of 0.970.

Additional toners were made using the recipe and procedure from Comparative Example Toner III, except that the neutralizing pH was varied to test the pH adjustment window. The results for these toners are shown in Table 2 below.

pH adjustment window

The pH adjustment window test results mentioned above for Comparative Example Toners I-III and Example Toner A are shown in FIG. 3 and Table 2 below. In particular, FIG. 3 shows a graph summarizing the data presented in Table 2.

Table 2

As shown in Table 2 and FIG. 3, the pH adjustment window for the toner containing the coupling agent (borax, zinc sulfate, or aluminum sulfate) was significantly larger than that of the Comparative Example toner for the conventional emulsion aggregation toner. The pH adjustment window width of I. As discussed above, the wider the pH adjustment window, the easier the process is to control on an industrial scale.

fusion window

Each toner composition was used to print 24# Hammermill laser paper at 50 pages per minute (50 ppm) using a fusing robot at a toner coverage of 1.1 ^mg /cm with various fusing temperatures (HMLP), as shown in Tables 3 and 4 below. The temperatures shown in Tables 3 and 4 are for the heating element/heater of the fusion robot. For each toner composition, various fusion level measurements were made. Measurements of these fusion ratings included the scratch resistance test shown in Table 3 and the conventional 60 degree gloss test shown in Table 4. For scratch resistance testing, printed samples were evaluated using a TABER ABRADER apparatus from TABER Industries, North Tonawanda, New York, USA. The printed samples were rated on a TABER ABRADER scale from 0 to 10 (with a rating of 10 representing the highest scratch resistance). The TABER ABRADER device scrapes the printed sample multiple times with varying forces until the toner is scraped off the sample. The point at which the toner is scraped off corresponds to a grade number between 0 and 10 on the TABER ABRADER grade scale. As is known in the art, a conventional 60 degree gloss test involves shining a known amount of light on the printed paper at an angle of 60 degrees and measuring its reflectance. A higher gloss test value indicates more energy is transferred to the substrate as it moves through the fuser. The glossiness of a print is also related to the resins and release agents used in the toner.

table 3

Table 4

As shown in Table 3, with the conventional emulsion aggregation toner (Comparative Example Toner I) and the toner containing zinc sulfate coupling agent or aluminum sulfate coupling agent (Comparative Example Toner II and III ) compared to Example toners A and B, which contained a borax coupling agent and were formed using the same resin as Comparative Example toners I-III, exhibited better fusing properties. The lower limit of the fusion window for Example Toners A and B is lower than that for Comparative Examples I-III. In particular, Example Toners A and B provided acceptable scratch resistance at temperatures as low as 200°C and 195°C, respectively. Comparative Example Toners I-III did not provide acceptable scratch resistance at these temperatures and instead exhibited cold offset ("CO"), meaning that the toner failed to fuse to the paper. Thus, less energy was required to accomplish an acceptable fusing operation for Example Toners A and B than for Comparative Example Toners I-III. Example Toners A and B also provided improved scratch resistance at elevated temperatures from 210°C to 230°C compared to Comparative Example Toners I-III.

The cores of Example Toners C and D were formed using the same resin as Example Toners A and B and Comparative Example Toners I-III, but a different resin was used to form Example Toner C and D's shell. However, as shown in Table 3, the lower limit of the fusion window for Example Toners C and D containing a borax coupling agent was lower than that for Comparative Examples I-III. Example toners C and D also exhibit improved scratch resistance at elevated temperatures from 210°C to 230°C compared to Comparative Example toners I-III.

Example Toner E was formed using a higher molecular weight resin having a higher glass transition temperature than the resins used to form Example Toners A and B and Comparative Example Toners I-III. It will be appreciated by those skilled in the art that higher molecular weight and higher glass transition temperatures of such resins are expected to compromise the lower limit of the fusion window. Table 3 shows that Example Toners A and B outperform Example Toner E because of the lower molecular weight and lower glass transition temperature resins used in Example Toners A and B. However, Example Toner E, which contained a borax coupling agent and a higher molecular weight and higher glass transition temperature resin, had the same fusing performance as Comparative Example Toners I-III, even with lower molecular weight and lower glass transition temperature resins. The fusing properties of Comparative Example Toners I-III of the resins having different transition temperatures were similar.

As shown in Table 4, Example Toners A to E exhibited comparable gloss test performance compared to Comparative Example Toner I. Compared to Example Toners A to E and Comparative Example Toner I, Comparative Example Toners II and III showed inferior gloss values.

Several of the embodiments described above have been provided for purposes of illustration. It is not intended to be exhaustive or to limit the application to the precise form disclosed, and obviously many modifications and variations are possible in light of the above described ideas. It is to be understood that the invention may be carried out otherwise than as expressly set forth herein without departing from the scope of the invention. It is intended that the scope of the application be defined by the claims appended hereto.

Claims (8)

1. a kind of method for producing toner and toner of chemical preparation, it includes：

Core, it has surface, and the core includes first polymer adhesive, colouring agent and releasing agent, the first polymer Adhesive has functional group；

Borax coupling agent, it is located on the surface of the core；And

Shell, it is formed on around the core and the borax coupling agent, and the shell includes second polymer adhesive, described Second polymer adhesive has functional group；

Wherein described borax coupling agent is located between the core and the shell and by its hydroxyl and described first and second Hydrogen bond is formed between the functional group of polymer adhesive and the shell is bonded to the surface of the core and in the shell The component of the core is gathered the core before being added, thus reduce fine particles remaining in the toner.

2. the method for producing toner and toner of chemical preparation as claimed in claim 1, wherein the first polymer adhesive and described Each self-contained polyester resin of second polymer adhesive.

3. the method for producing toner and toner of chemical preparation as claimed in claim 2, wherein the first polymer adhesive includes the One polyester resin or mixture and the second polymer adhesive, which are included, is different from first polyester resin or mixture The second polyester resin or mixture.

4. the method for producing toner and toner of chemical preparation as claimed in claim 1, wherein the first polymer adhesive and described Each self-contained styrene polymer of second polymer adhesive.

5. the method for producing toner and toner of chemical preparation as claimed in claim 4, wherein the first polymer adhesive includes the One styrene polymer or mixture and the second polymer adhesive, which are included, is different from first styrene polymer Or the second styrene polymer or mixture of mixture.

6. the method for producing toner and toner of chemical preparation as claimed in claim 1, wherein the first polymer adhesive with it is described The ratio of second polymer adhesive is by weight 20:80 and 80:Between 20.

7. the method for producing toner and toner of chemical preparation as claimed in claim 6, wherein the first polymer adhesive with it is described The ratio of second polymer adhesive is by weight 50:50 and 80:Between 20.

8. the method for producing toner and toner of chemical preparation as claimed in claim 1, wherein the core and the shell are poly- comprising identical Compound adhesive.