JP5294890B2 - toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner which has an excellent low temperature fixability, is excellent in heat reservation property, hardly causes contamination of each member due to oozing of a release agent even in the use over a long time and hardly causes deterioration in image quality. <P>SOLUTION: The toner includes toner particles each of which has such a core-shell structure in which a cover layer is formed on the surface of a core particle comprising a binder resin, a colorant and a release agent, wherein a glass transition temperature Tg1(&deg;C) of the core particle is 20 to 55&deg;C, a glass transition temperature Tg2(&deg;C) of the cover layer is 60 to 100&deg;C, and a change amount (%) of methanol concentration when the transmittance of light in a wetting test for a methanol/water mixed solvent upon heat treatment of the toner particle becomes 50% satisfies predetermined conditions. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a toner used to form a toner image by developing an electrostatic latent image formed by a method such as electrophotography, electrostatic recording, or toner jet recording.

  Various methods are known as image forming methods by electrophotography. Generally, an electrostatic latent image is formed on an electrostatic charge image bearing member (hereinafter also referred to as “photosensitive member”) by using a photoconductive substance by various means. Next, the electrostatic latent image is developed with toner to form a toner image. If necessary, the toner image is transferred to a transfer material such as paper, and then the toner image is fixed on the transfer material by heat or pressure. Thus, a copy or a print is obtained. Such image forming apparatuses include printers and copiers.

  In recent years, these printers and copiers are required to increase the resolution of images by digitization, and at the same time, increase the printing or copying speed, or save space and reduce power consumption by downsizing the apparatus. Yes.

  Various types of fixing devices used in printers and copiers have been put into practical use, but the most common method is a thermocompression bonding method using a heat roller. In this method, a transfer material on which a toner image is transferred between a heat roller having a surface made of a material having releasability with respect to toner and a pressure roller that presses the surface is transferred to the toner image surface of the transfer material. Fixing is performed by passing the toner so as to be in contact with the heat roller side. In this method, since the surface of the heat roller and the toner image surface of the transfer material come into contact with each other under pressure, the heat efficiency when the toner is fused on the transfer material is excellent. It is preferably used.

  Further, as a method used for applications requiring low power consumption, a film fixing method can be mentioned as a representative method. In this method, a film unit having a heating device is used instead of the heat roller, and the transfer material on which the toner image is transferred is passed between the film and the pressure roller under a relatively low pressure. Fixing. In this method, the heat capacity of the film is small and the wait time can be shortened, so that the power consumption can be reduced.

  In order to satisfy the above-described demands for higher speed and lower power consumption, improvement in fixing performance of the toner itself is also required. That is, it is desired to realize a toner that can be fixed at a lower temperature.

  In general, toner is fine particles having a particle size of about 5 to 30 μm, mainly composed of a binder resin, a dye, a pigment, carbon black, and a colorant such as a magnetic material. It is manufactured by a wet process typified by a turbid polymerization process.

  The toner by the pulverization method is obtained by melting and uniformly dispersing the colorant and, if necessary, a charge control agent and a release agent in a thermoplastic resin as a binder resin, and then obtaining the resin composition obtained. Is obtained by pulverizing and classifying.

  On the other hand, in the toner by suspension polymerization method, the above-mentioned colorant and, if necessary, a polyfunctional monomer, a chain transfer agent, a charge control agent and a release agent are used as the polymerizable monomer. A polymerizable monomer composition is obtained by dissolving or dispersing. Then, it is suspended in an aqueous medium containing a dispersion stabilizer together with a polymerization initiator, granulated, and polymerized with a polymerizable monomer while heating to obtain polymer particles having a desired particle size. Is.

  As a general method for improving the low-temperature fixability of these toners, a method of lowering the glass transition temperature of a binder resin constituting the toner is known. However, simply lowering the glass transition temperature decreases the heat-resistant storage stability of the toner, and when used in a high-temperature environment, the toner that agglomerates between the toners that come into contact with each other tends to cause a blocking phenomenon. Arise.

  In addition, even under normal temperature environments, the release agent oozes out during long-term use, which easily causes contamination of each member such as toner carrier contamination and filming on the photoreceptor. As a result, there is a problem that the image quality is degraded.

  In order to solve these problems, a capsule structure comprising a core particle containing a resin having a low glass transition temperature and an outer shell containing a resin having a high glass transition temperature formed so as to cover the surface of the core particle ( A toner having a core-shell structure has been devised.

  For example, by adding an aqueous dispersion of resin fine particles obtained by emulsion polymerization or soap-free emulsion polymerization to polymer particles (core particles) obtained by suspension polymerization, 95% or more of the surface of the polymer particles is obtained. There has been proposed a toner that is coated with fine particles and then heated to a temperature higher than the glass transition temperature of the polymer particles to make the surface substantially free of bulges (see Patent Document 1).

  In addition, resin fine particles obtained by mixing an acidic group-containing resin with an aqueous medium in the presence of a basic neutralizer and phase inversion emulsification are mixed with an aqueous dispersion of polymer particles (core particles), followed by acid. The resin fine particles are deposited on the surface of the polymer particles by removing the liquid medium, and the dried powder is stirred and mixed with heating to fix the acid group-containing resin (resin fine particles) to the surface of the polymer particles. Toner has been proposed (see Patent Document 2).

  Further, an intermediate layer having a chargeability opposite to that of the toner inner core particles is formed on the surface of the toner inner core particles (core particles), and a resin (resin fine particles) having a chargeability opposite to that of the intermediate layer is formed on the surface of the intermediate layer. A method of forming an outer shell layer has been proposed (see Patent Document 3).

  Among the above-described conventional examples, in the toner disclosed in Patent Document 1, the resin fine particles are attached to the core particles only by adjusting the pH of water, which is a medium, and the fine particles tend to aggregate. A sufficiently uniform coating layer could not always be formed. When heating is performed in such a state to obtain a surface having no bulge, part of the encapsulated release agent may ooze out, and as a result, image quality is likely to deteriorate due to contamination of each member. There was a problem.

  In addition, the toner disclosed in Patent Document 2 described above is formed by adding acid to the aqueous dispersion to return the acid groups of the resin fine particles to an unneutralized state, thereby precipitating the resin fine particles on the surface of the core particles. A shell layer is formed. However, in this method, the resin fine particles are easily aggregated, and the deposited state on the surface of the core particle is not necessarily uniform. Furthermore, since filtration and drying are performed without heating, the precipitated resin fine particles may fall off. If heating and stirring are mixed in this state, the release agent may ooze out on the surface of the particles. It was. As a result, not only the image quality is likely to deteriorate due to contamination of each member, but also sufficient heat-resistant storage stability cannot be obtained.

  In addition, in the toner disclosed in Patent Document 3 described above, in particular, when inorganic fine particles are used as the intermediate layer, the adhesion strength of the coating layer is not sufficient, so that a dense coating layer cannot be formed, and as a result, sufficient It was not possible to suppress the release of the release agent.

  As described above, in a toner having a capsule structure composed of core particles having a low glass transition temperature and an outer shell having a high glass transition temperature, a denser coating layer is used to suppress the release of the release agent. Therefore, there is a demand for a toner that has both good fixability and heat-resistant storage stability.

JP 2000-112174 A JP 2000-347455 A JP 2003-91093 A

  An object of the present invention is to provide a toner that solves the above-described conventional problems.

  That is, the object of the present invention is to have excellent low-temperature fixability, excellent heat-resistant storage stability, and less likely to cause contamination of each member due to exudation of a release agent even during long-term use, and image quality is unlikely to deteriorate. To provide toner.

The present invention is a toner having toner particles having a core-shell structure in which a coating layer is formed on the surface of core particles containing at least a binder resin , a colorant and a release agent,
The glass transition temperature Tg1 (° C.) of the core particles is 20 to 55 ° C., and the glass transition temperature Tg2 (° C.) of the coating layer is 60 to 100 ° C.
In the wettability test of the toner particles to a mixed solvent of methanol / water,
i) The methanol concentration V _ini (volume%) when the light transmittance measured at a temperature of 25.0 ° C. is 50% is 0.5 to 20.0%,
ii) In the temperature range of 35.0 to 60.0 ° C., the toner particles are heated for 3 days under a temperature condition changed from 35.0 ° C. to 2.5 ° C. , and then the temperature is 25.0 ° C. Then, a wettability test on a mixed solvent of methanol / water was conducted, and methanol concentrations V _35.0 , V _37.5 , V _40.0 , V _42.5 , V _45.0 , V _47.5 , V _50.0 , V when the light transmittance was 50% _52.5, V _55.0, measured V _57.5, V _60.0 (volume%), respectively, by subtracting the methanol concentration or al methanol concentration V _ini obtains a variation in the temperature, the variation amount and the vertical axis, horizontal axis heated plotted on the processing temperature coordinates, in graph form by connecting each plot a straight line, the temperature at which the change amount of 10% and T10 (° C.), when the amount of change is 30% When the temperature is T30 (° C.), T10 ° C.) and T30 (° C.) The following equation (1) and (2)
T10 (° C)> Tg1 (° C) (1)
T30 (° C.) − T 10 (° C.) <5.0 (° C.) (2)
The present invention relates to a toner characterized by satisfying

  According to the present invention, a toner having excellent low-temperature fixability, excellent heat-resistant storage stability, and hardly contaminating each member due to exudation of a release agent even during long-term use, and hardly causing deterioration in image quality. Can be provided.

  It is desirable that the release agent contained in the toner particles is completely encapsulated without being exposed on the surface of the toner particles, and oozes out quickly on the surface of the toner particles at the time of fixing. When a release agent is present on the toner surface, it may cause contamination of each member such as contamination of the toner carrier and filming on the photosensitive member, which may cause deterioration in image quality.

  In addition, when used in a high temperature environment or for a long period of time, the release agent contained in the toner particles may gradually ooze out, resulting in contamination of each member and a reduction in image quality. there were.

  On the other hand, the wettability test with respect to a methanol / water mixed solvent is a method often used as a means for evaluating the surface state of toner particles. Examples of the toner raw material that affects the wettability with respect to the methanol / water mixed solvent include a release agent, a colorant, and a charge control agent. Among these, since the release agent is particularly hydrophobic, when the release agent is present on the surface of the toner particles, it becomes difficult to wet unless the methanol concentration in the mixed solvent is high.

  The inventors of the present invention have used light transmittance in a wettability test with respect to a methanol / water mixed solvent when the toner particles are heat-treated as an index that quantitatively represents the ease with which the release agent permeates into the toner particles. Attention was paid to the amount of change in methanol concentration (volume%) at 50%.

  That is, the present inventors have satisfied that the amount of change satisfies a specific condition, so that it is difficult to cause contamination of each member due to exudation of a release agent even in use under a high temperature environment or for a long period of use. It has been found that an image can be obtained and a toner having excellent low-temperature fixability and heat-resistant storage stability can be obtained, and the present invention has been completed.

Specifically, in the wettability test of the toner particles with respect to the methanol / water mixed solvent, the methanol concentration V _ini (volume%) when the light transmittance measured at a temperature of 25.0 ° C. becomes 50% is 0. 5 to 20.0%,
The toner particles are heat-treated in a temperature range of 35.0 to 60.0 ° C. for 3 days under a temperature condition of every 2.5 ° C. and then subjected to a methanol / water mixed solvent under a temperature condition of 25.0 ° C. Methanol concentration V _35.0 , V _37.5 , V _40.0 , V _42.5 , V _45.0 , V _47.5 , V _50.0 , V _52.5 , V _55.0 , V _57.5 , V _60.0 when the light transmittance in the wettability test is 50% ( Volume%)
_{Subtract the} methanol concentration V _ini from the methanol concentration V _{35.0 to} V _{60.0 at} each temperature to obtain the amount of change, and plot each amount of change in coordinates where the vertical axis is the amount of change and the horizontal axis is the heat treatment temperature, In the graph formed by connecting each plot with a straight line,
When the temperature when the amount of change is 10% is T10 (° C) and the temperature when the amount of change is 30% is T30 (° C),
T10 (° C) and T30 (° C) are the following relational expressions (1) and (2)
(1) T10 (° C.)> Tg 1 (° C.)
(2) T30 (° C.) − T10 (° C.) <5.0 (° C.)
The above condition is satisfied.

  Hereinafter, in the wettability test with respect to the methanol / water mixed solvent, the methanol concentration (volume%) when the light transmittance is 50% is also simply referred to as methanol concentration.

  In the present invention, the methanol concentration of 0.5 to 20.0% measured under the condition of 25.0 ° C. means that substantially no release agent is present on the toner particle surface.

  In addition, when the amount of change between the methanol concentration when the toner particles are heat-treated and the methanol concentration when measured under the condition of 25.0 ° C. is less than 10%, the release agent is sufficiently exuded. I think that it is suppressed to. In the present invention, the heating temperature T10 (° C.) when the amount of change in methanol concentration by heat treatment is 10% is higher than the glass transition temperature Tg1 (° C.) of the core particles (core of core-shell structure). It means that it is possible to sufficiently suppress the exudation of the release agent due to use in the environment or use over a long period of time.

  Therefore, with toner particles that satisfy the above conditions, contamination of each member hardly occurs even when used under a high temperature environment or for a long time, and a good image can be obtained.

  On the other hand, in order to obtain excellent fixability, it is necessary for the encapsulated release agent to ooze out quickly on the toner particle surface in the fixing temperature region. In the present invention, when the amount of change in methanol concentration by heat treatment exceeds 30%, it is considered that a sufficient amount of the release agent has oozed out on the surface of the toner particles. The difference between the heating temperature T30 (° C.) and the T10 (° C.) when the amount of change in methanol concentration by heat treatment is 30% is within 5.0 ° C. It means to ooze out to the surface. Thereby, good fixability can be obtained.

  As described above, the suppression of the release agent leaching and the rapid release of the release agent to the toner surface are contradictory behaviors, which cannot be achieved with conventional core-shell toners. . In the present invention, the above-described conflicting behaviors can be achieved simultaneously by forming the coating layer (core-shell structure shell) extremely densely and thinly.

  In the present invention, the difference between T30 (° C.) and T10 (° C.) is more preferably smaller than 3.0 ° C.

  In the toner particles of the present invention, the glass transition temperature Tg1 (° C.) of the core particles is 20 to 55 ° C. This makes it possible to obtain excellent low temperature fixability. When the glass transition temperature Tg1 (° C.) of the core particles is lower than 20 ° C., sufficient heat-resistant storage stability cannot be obtained, and the loadability as an image may be deteriorated, which is not practical. When the glass transition temperature Tg1 (° C.) of the core particles is higher than 55 ° C., sufficient low-temperature fixability cannot be obtained.

  On the other hand, for the purpose of improving heat-resistant storage stability, the glass transition temperature Tg2 (° C.) of the coating layer needs to be 60 to 100 ° C. When the glass transition temperature Tg2 (° C.) of the coating layer is lower than 60 ° C., sufficient heat resistant storage stability cannot be obtained. When the glass transition temperature Tg2 (° C.) of the coating layer is higher than 100 ° C., the fixability of the core particles is hindered, and as a result, sufficient low-temperature fixability may not be obtained.

  In the present invention, the difference between the glass transition temperature Tg1 (° C.) of the core particles and the glass transition temperature Tg2 (° C.) of the coating layer is preferably in the range of 15 to 50 ° C. If the difference in glass transition temperature is less than 15 ° C., a sufficient effect of improving heat-resistant storage stability cannot be obtained, and if it exceeds 50 ° C., the low-temperature fixability is impaired.

  In the present invention, the wettability of the toner is determined from a curve showing the relationship between the methanol concentration and the light transmittance obtained as follows.

  First, 60 ml of water is put into a cylindrical glass container having a diameter of 5 cm and a thickness of 1.75 mm, and dispersed for 5 minutes with an ultrasonic disperser in order to remove bubbles and the like in the measurement sample.

  Next, 0.1 g of toner particles are precisely weighed and added to the container containing the water to prepare a sample solution for measurement.

  Then, the measurement sample solution is set in a powder wettability tester “WET-100P” (manufactured by Reska). The sample liquid for measurement is stirred at a speed of 350 rpm using a magnetic stirrer. As the rotor of the magnetic stirrer, a spindle type rotor having a length of 25 mm and a maximum barrel diameter of 8 mm coated with a fluororesin is used.

  Next, the transmittance of light at a wavelength of 780 nm is measured while continuously adding methanol at a drop rate of 0.8 ml / min to the measurement sample solution through the above apparatus, and a methanol drop transmittance curve is created. (See FIG. 1).

  The core particles in the present invention are obtained by dispersing a polymerizable monomer composition containing at least a polymerizable monomer, a colorant, and a release agent in an aqueous medium, and polymerizing the polymerizable monomer. It is preferable that

  The specific production method will be explained. First, at least a colorant and a release agent are added to the polymerizable monomer that is the main constituent material of the core particles, and a disperser such as a homogenizer, a ball mill, a colloid mill, or an ultrasonic disperser. To prepare a polymerizable monomer composition in which these are uniformly dissolved or dispersed. At this time, in the polymerizable monomer composition, a polyfunctional monomer, a chain transfer agent, a charge control agent, a plasticizer, and other additives (for example, a pigment dispersant, Release agent dispersant) can be added as appropriate.

  Next, the polymerizable monomer composition is put into an aqueous medium containing a dispersion stabilizer prepared in advance, and suspended using a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser. Granulate.

  The polymerization initiator may be mixed with other additives when preparing the polymerizable monomer composition, or may be mixed into the polymerizable monomer composition just before being suspended in the aqueous medium. Good. Moreover, it can also be added in the state melt | dissolved in the polymerizable monomer or other solvent as needed during granulation or after granulation completion, ie, just before starting a polymerization reaction.

  In the polymerization reaction, the granulated suspension is heated to a temperature of 50 to 90 ° C., the particles of the polymerizable monomer composition in the suspension maintain the particle state, and the particles float and settle. To avoid this, it is carried out with stirring.

  The said polymerization initiator decomposes | disassembles easily by heating and produces | generates a free radical (radical). The generated radical is added to the unsaturated bond of the polymerizable monomer to newly generate an adduct radical. The generated adduct radical is further added to the unsaturated bond of the polymerizable monomer. By repeating such an addition reaction in a chain, the polymerization reaction proceeds, and core particles containing the polymerizable monomer as a main constituent material are formed.

  Distillation may be performed using a known method such as reduced pressure or elevated temperature after the second half of the polymerization reaction or after the completion of the polymerization reaction. By performing the distillation step, the remaining unreacted polymerizable monomer can be removed.

  Specific examples of the method for forming the coating layer include a method of attaching resin fine particles to the surface of the core particles. When the resin fine particles are attached to the surface of the core particle, it is usually performed in a state where they are dispersed in an aqueous medium. When the polarities of the core particles and the resin fine particles are greatly different, they can be attached by an electric suction force. Otherwise, it is necessary to control the dispersion state of the resin fine particles using an external means. . Specific methods include a method of adjusting the pH of the aqueous medium and a method of adding an inorganic salt in the aqueous medium. In either case, if the dispersion state of the resin fine particles is suddenly changed, the resin fine particles cause single aggregation and cannot be uniformly adhered, so that these operations are preferably performed gradually.

  In addition, after the resin fine particles are attached, they are fixed or fused so that they do not easily peel off or fall off. As a specific method, there are a method in which heat treatment is performed in a state dispersed in an aqueous medium, and a method in which a solvent that dissolves or swells resin fine particles is added and absorbed to form a film, and then the solvent is removed. Moreover, the method of stirring and mixing the powder taken out by filtering and drying under heating can be mentioned. Among these methods, the method of heat treatment in an aqueous medium is preferable in that it can be fixed more uniformly and firmly and the operation is simple.

  A particularly preferred example of the method for attaching and fixing the fine resin particles to achieve the present invention will be described below.

  First, core particles are produced by a suspension polymerization method according to the method described above. At this time, for the dispersion stabilizer, for example, an inorganic dispersant having a significantly different polarity with respect to the core particle such as tricalcium phosphate is used, and the dispersion stabilizer attached to the surface of the core particle is not removed even after the completion of the polymerization. Continue stirring as it is.

  Next, an aqueous dispersion of resin fine particles having the same polarity as the core particles and a glass transition temperature higher than that of the core particles is added to the core particle dispersion with the dispersion stabilizer attached. To do. Thereby, the resin fine particles are uniformly attached in a state where the dispersion stabilizer is interposed on the surface of the core particle.

  At this time, the resin fine particles are preferably self-dispersing resin fine particles having a carboxyl group and / or a sulfonic acid group. Since the self-dispersing resin fine particles having a carboxyl group and / or a sulfonic acid group are negatively charged in water, they are suitable for the above-described method.

  In particular, the resin fine particles are more preferably self-dispersing resin fine particles having a sulfonic acid group. Self-dispersing resin fine particles having a sulfonic acid group are more negatively charged in water than self-dispersing resin fine particles having a carboxyl group. Accordingly, the electric attractive force with the positively chargeable dispersion stabilizer adhering to the surface of the core particle is increased, and a more uniform and dense coating layer can be formed.

  Next, this dispersion is heated until the temperature becomes equal to or higher than the glass transition temperature of the core particles.

  Then, while maintaining the temperature of the dispersion within a temperature range from the glass transition temperature of the core particles to the glass transition temperature of the resin fine particles, an acid is added thereto to dissolve the dispersion stabilizer. When the dispersion stabilizer is removed, at the same time, the resin fine particles come into contact with the surface of the core particles and are fixed.

  At this time, it is preferable to add an acid so that the pH of the dispersion changes at a constant rate. By making the pH change rate constant, the dispersion stabilizer is gradually dissolved. As a result, the resin fine particles are hardly peeled off or dropped off, and a denser coating layer can be formed.

  Moreover, it is preferable that a mold release agent does not exist substantially on the surface of the core particle used at this time. Since the release agent is not substantially present on the surface of the core particles, the adhesion between the core particles and the resin fine particles is improved, and a denser coating layer can be formed.

  Further, the resin fine particles as the constituent material of the coating layer used in the present invention may be produced by any method, and known methods such as an emulsion polymerization method, a soap-free emulsion polymerization method, and a phase inversion emulsification method. Can be used. Among these production methods, the phase inversion emulsification method is particularly suitable because it does not require an emulsifier or a dispersion stabilizer and resin particles having a smaller particle diameter can be easily obtained.

  In the phase inversion emulsification method, a resin having self-dispersibility or a resin capable of developing self-dispersibility by neutralization is used. Here, the resin having self-water dispersibility is a resin containing a functional group capable of self-dispersion in an aqueous medium in the molecule, specifically, a carboxyl group, a sulfonic acid group, a phosphoric acid group, or It is a resin containing these salts. Further, a resin that can exhibit self-dispersibility by neutralization is a resin that contains a functional group in the molecule that can increase self-dispersibility in an aqueous medium by neutralization.

  When these resins are dissolved in an organic solvent, a neutralizing agent is added as necessary, and mixed with an aqueous medium while stirring, the solution of the resin undergoes phase inversion emulsification to produce fine particles. The organic solvent is removed using a method such as heating and decompression after phase inversion emulsification.

  Thus, according to the phase inversion emulsification method, a stable aqueous dispersion of resin fine particles can be obtained without substantially using an emulsifier or a dispersion stabilizer.

  As the material of the resin, any resin can be used as long as it can be used as a binder resin for toner, and vinyl resins, polyester resins, epoxy resins, urethane resins and the like are used. Among them, polyester resins have sharp melt properties. Therefore, it is preferable that the low temperature fixability of the core particles is not impaired.

  Moreover, it is preferable that the coating amount of the coating layer is 1.0 to 10.0% by mass ratio with respect to the core particles. If the coating amount is less than 1.0%, the core particles cannot be covered uniformly, and not only the release of the release agent cannot be sufficiently suppressed, but also the heat resistant storage stability is lowered. When the coating amount exceeds 10.0%, the release agent does not quickly migrate to the surface of the toner particles at the time of fixing, and the toner fixability may deteriorate.

  When the coating layer contains an intrinsic element (for example, S element derived from a sulfonic acid group), the coating amount is included in the toner using, for example, a fluorescent X-ray analyzer (XRF). It can be calculated by performing quantitative analysis of elements.

  Moreover, in this invention, it is preferable that content of the said mold release agent is 3.0 to 30.0% by mass ratio with respect to the said binder resin. If the content of the release agent is less than 3.0%, the fixability may be lowered. When the content of the release agent exceeds 30.0%, the release agent may not be completely encapsulated in the core particles. If the coating layer is formed in a state where the release agent is present on the surface of the core particle, the adhesion between the core particle and the coating layer is lowered, and a dense coating layer cannot be formed. Therefore, there is a possibility that the release agent is likely to ooze out in a high temperature environment or during long-term use.

  Examples of those that can be used for the release agent used in the present invention include the following. Petroleum wax such as paraffin wax, microcrystalline wax, petrolatum and derivatives thereof; montan wax and derivatives thereof; hydrocarbon wax and derivatives thereof according to Fischer-Tropsch method; polyolefin wax and derivatives thereof represented by polyethylene; carnauba wax and candelilla Natural waxes such as waxes and derivatives thereof. Derivatives include block copolymers with oxides and vinyl monomers, and graft modified products. Furthermore, higher fatty alcohols, fatty acids such as stearic acid and palmitic acid, or compounds thereof, acid amide waxes, ester waxes, ketones, hydrogenated castor oil and derivatives thereof, plant-based waxes and animal waxes can also be used.

  Among these release agents, paraffin wax that is more easily included in the core particles is particularly preferable.

  Here, the following are mentioned as a polymerizable monomer which can be used as the main constituent material of the said core particle.

  Styrene; α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert- Styrenes such as butyl styrene, pn-hexyl styrene, pn-octyl, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-phenyl styrene Monomer: methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, acrylic acid 2-chloroethyl, phenyl acrylate, acrylic acid-2-hydro Acrylic esters such as ethyl; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, methacrylic acid Methacrylic acid esters such as stearyl, phenyl methacrylate, 2-hydroxyethyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; acrylonitrile, methacrylonitrile, acrylamide.

  Among these polymerizable monomers, it is preferable to use a mixture of styrene or a styrene derivative and another polymerizable monomer from the viewpoint of developing characteristics and durability of the toner. The mixing ratio of these polymerizable monomers may be appropriately selected in consideration of the desired glass transition temperature of the core.

  The polymerization initiator used in the production of the core particles is not particularly limited, and a known peroxide polymerization initiator or azo polymerization initiator can be used.

  Examples of peroxide polymerization initiators include the following. t-butyl peroxylaurate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxyisobutyrate, t- Butyl peroxyacetate, t-butyl peroxyisononanoate, t-butyl peroxybenzoate, t-amyl peroxyneodecanoate, t-amyl peroxypivalate, t-amyl peroxy-2-ethylhexano Ate, t-amyl peroxyacetate, t-amyl peroxyisononanoate, t-amyl peroxybenzoate, t-hexyl peroxyneodecanoate, t-hexyl peroxypivalate, t-hexyl peroxy-2 -Ethyl hexanoate, t-hexyl peroxybenzoe Α-cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate 1-cyclohexyl-1-methylethylperoxyneodecanoate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, 2,5-dimethyl-2,5-bis ( Peroxyester polymerization such as benzoylperoxy) hexane, t-butylperoxy-3,5,5-trimethylhexanoate, 2,5-dimethyl-2,5-bis (m-toluoylperoxy) hexane Initiator: di-n-propyl peroxydicarbonate, di-n-butyl peroxydicarbonate, di-n-pentylperoxydicarbonate Diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, di (2-ethylhexyl) peroxydicarbonate, di (2-ethoxyethyl) peroxydicarbonate, di (3-methoxybutyl) peroxydi Peroxydicarbonate-based polymerization initiators such as carbonate and di (4-t-butylcyclohexyl) peroxydicarbonate; diisobutyryl peroxide, diisononanoyl peroxide, di-n-octanoyl peroxide, dilauroylper Diacyl peroxide polymerization initiators such as oxide, distearoyl peroxide, dibenzoyl peroxide, di-m-toluoyl peroxide, benzoyl-m-toluoyl peroxide; t-hexylperoxyiso Peroxymonocarbonate polymerization initiators such as propyl monocarbonate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy 2-ethylhexyl monocarbonate, t-butylperoxyallyl monocarbonate; 1,1-di- t-hexylperoxycyclohexane, 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 1,1-di-t-butylperoxycyclohexane, 2,2-di-t-butyl Peroxyketal polymerization initiators such as peroxybutane; dialkyl peroxide polymerization initiators such as dicumyl peroxide, di-t-butyl peroxide, and t-butylcumyl peroxide.

  Examples of the azo polymerization initiator include the following. 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis -4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile.

  Among these polymerization initiators, peroxide-based polymerization initiators are preferable because there is little residue of decomposition products. In addition, two or more of these polymerization initiators can be used simultaneously as necessary. In this case, the preferred amount of the polymerization initiator used is 0.1 to 20 parts by mass with respect to 100 parts by mass of the monomer.

  In the production of the core particles, a chain transfer agent can be used for the purpose of adjusting the molecular weight. Examples of the chain transfer agent include the following. n-pentyl mercaptan, isopentyl mercaptan, 2-methylbutyl mercaptan, n-hexyl mercaptan, n-heptyl mercaptan, n-octyl mercaptan, t-octyl mercaptan, t-nonyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, alkyl mercaptans such as n-tetradecyl mercaptan, t-tetradecyl mercaptan, n-pentadecyl mercaptan, n-hexadecyl mercaptan, t-hexadecyl mercaptan, stearyl mercaptan; alkyl esters of thioglycolic acid; mercaptopropionic acid Alkyl esters; halogenated hydrocarbons such as chloroform, carbon tetrachloride, ethylene bromide, carbon tetrabromide; α-methylstyrene dimer.

  These chain transfer agents are not necessarily used, but a preferable addition amount when used is 0.05 to 3 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  In the production of the core particles, a small amount of a polyfunctional monomer can be used in combination for the purpose of improving high temperature offset resistance. The high temperature offset is a phenomenon in which a part of the toner melted at the time of fixing adheres to the surface of the above-described heat roller or fixing film, which contaminates the subsequent fixing sheet. As the polyfunctional monomer, a compound having two or more polymerizable double bonds is mainly used. Aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylate esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate and 1,3-butanediol dimethacrylate; divinylaniline, divinyl ether and divinyl Divinyl compounds such as sulfide and divinyl sulfone; compounds having three or more vinyl groups.

  These polyfunctional monomers are not necessarily used, but a preferable addition amount when used is 0.01 to 1 part by mass with respect to 100 parts by mass of the polymerizable monomer.

  In the production of the core particles, as the dispersion stabilizer added to the aqueous medium, known surfactants, organic dispersants, and inorganic dispersants can be used. Among these, inorganic dispersants can be suitably used because they are less likely to produce ultrafine powder, are less likely to lose stability even when the polymerization temperature is changed, are easily washed, and do not adversely affect the toner. Examples of such inorganic dispersants include the following. Polyvalent metal phosphates such as tricalcium phosphate, magnesium phosphate, aluminum phosphate and zinc phosphate; carbonates such as calcium carbonate and magnesium carbonate; inorganic salts such as calcium metasuccinate, calcium sulfate and barium sulfate; Inorganic oxides such as calcium hydroxide, magnesium hydroxide, aluminum hydroxide, silica, bentonite and alumina.

  When these inorganic dispersants are used, they may be used as they are in an aqueous medium, but in order to obtain finer particles, they are prepared and used in an aqueous medium using a compound capable of generating inorganic dispersant particles. You can also. For example, in the case of tricalcium phosphate, sodium phosphate aqueous solution and calcium chloride aqueous solution can be mixed under high-speed stirring to produce water-insoluble tricalcium phosphate, which enables more uniform and fine dispersion. Become. These inorganic dispersants can be almost completely removed by adding an acid or an alkali after the polymerization and dissolving.

  These inorganic dispersants are desirably used alone in an amount of 0.2 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer, but if necessary, 0.001 to 0.1 parts by mass. Some surfactants may be used in combination. Examples of the surfactant include the following. Sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate.

  Moreover, in this invention, you may superpose | polymerize by adding resin in the polymerizable monomer composition mentioned above.

  For example, a polyester resin is a relatively polar resin containing many ester bonds. When this polyester resin is dissolved in the polymerizable monomer composition and polymerized, the resin tends to move to the surface layer of the droplets in the aqueous medium, and is unevenly distributed on the surface of the particle as the polymerization proceeds. Therefore, the granulation property is improved, and the aforementioned release agent can be easily included.

  As said polyester resin, what polycondensated the polyhydric alcohol component and the polyhydric carboxylic acid component by the well-known method can be used.

  Examples of the divalent alcohol include the following. Ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, diethylene glycol, dipropylene glycol, triethylene glycol, 1, 5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, neopentyl glycol, 2,2,4-trimethylpentane-1,3-diol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, hydrogenated bisphenol A, a bisphenol derivative represented by the following general formula (I), or a diol represented by the following formula (II).

（式中、Ｒはエチレン又はプロピレン基であり、ｘ及びｙはそれぞれ１以上の整数であり、且つｘ＋ｙの平均値は２乃至１０である。）

(In the formula, R is an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 10.)

（式中、Ｒ’は−ＣＨ₂ＣＨ₂−、−ＣＨ₂ＣＨ（ＣＨ₃）−、または−ＣＨ₂−Ｃ（ＣＨ₃）₂−である。）

(In the formula, R ′ represents —CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) —, or —CH ₂ —C (CH ₃ ) ₂ —).

  Examples of trihydric or higher alcohols include the following. Sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene.

  These alcohol components may be used alone or in a mixed state.

  Examples of the divalent carboxylic acid include the following. Dicarboxylic acids such as naphthalenedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, succinic acid, adipic acid, sebacic acid, azelaic acid; phthalic anhydride, maleic anhydride, etc. Dicarboxylic acid anhydrides; lower alkyl esters of dicarboxylic acids such as dimethyl terephthalate, dimethyl maleate and dimethyl adipate.

  Moreover, you may make it bridge | crosslink by using trivalent or more carboxylic acid. The following are mentioned as carboxylic acid more than trivalence. Trimellitic acid, tri n-ethyl 1,2,4-tricarboxylate, tri n-butyl 1,2,4-tricarboxylate, tri n-hexyl 1,2,4-tricarboxylate, 1,2,4-benzene Triisobutyl tricarboxylate, tri n-octyl 1,2,4-benzenetricarboxylate, tri-2-ethylhexyl 1,2,4-benzenetricarboxylate, and lower alkyl esters of tricarboxylic acid.

  Moreover, you may use a monovalent | monohydric carboxylic acid component and a monovalent alcohol component to such an extent that the characteristic of a polyester resin is not impaired. Examples of the monovalent carboxylic acid component include the following. Benzoic acid, naphthalenecarboxylic acid, salicylic acid, 4-methylbenzoic acid, 3-methylbenzoic acid, phenoxyacetic acid, biphenylcarboxylic acid, acetic acid, propionic acid, butyric acid, octanoic acid, decanoic acid, dodecanoic acid, stearic acid. Examples of the monovalent alcohol component include the following. n-butanol, isobutanol, sec-butanol, n-hexanol, n-octanol, lauryl alcohol, 2-ethylhexanol, decanol, cyclohexanol, benzyl alcohol, dodecyl alcohol.

  The addition amount of the resin is preferably in the range of 1 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer. If it is less than 1 part by mass, the effect of addition is small, and if it exceeds 20 parts by mass, it becomes difficult to design various physical properties of the toner.

  As the colorant used in the toner of the present invention, known ones can be used, and examples thereof include carbon black as a black colorant, magnetic powder, and yellow / magenta / cyan colorants shown below.

  Examples of the yellow colorant include the following. Condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, allylamide compounds. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168, 180 are preferably used.

  Examples of the magenta colorant include the following. Condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, and 254 are preferably used.

  Examples of the cyan colorant include the following. Copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 are preferably used.

  These colorants can be used alone or in combination, and further in the form of a solid solution. When magnetic powder is used as the black colorant, the amount added is preferably 40 to 150 parts by mass with respect to 100 parts by mass of the polymerizable monomer. When carbon black is used as the black colorant, the amount added is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer. Further, in the case of a color toner, it is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner, and its preferable addition amount is based on 100 parts by mass of the polymerizable monomer. 1 to 20 parts by mass.

  These colorants need to pay attention to polymerization inhibition and aqueous phase migration, and are preferably subjected to surface modification such as a hydrophobization treatment as necessary. For example, a preferable method for surface-treating a dye-based colorant includes a method in which a polymerizable monomer is polymerized in the presence of a dye in advance, and the obtained colored polymer is added to the monomer composition. . For carbon black, in addition to the same treatment as the above dye, a grafting treatment may be performed with a substance that reacts with the surface functional group of carbon black, for example, polyorganosiloxane.

  In addition, the magnetic powder is mainly composed of iron oxide such as triiron tetroxide and γ-iron oxide, and since it is generally hydrophilic, it is magnetic by interaction with water as a dispersion medium. The powder tends to be unevenly distributed on the particle surface. Therefore, the toner particles obtained are inferior in fluidity and uniformity of triboelectric charge due to the magnetic powder exposed on the surface. Therefore, the surface of the magnetic powder is preferably subjected to a hydrophobic treatment uniformly with a coupling agent. Examples of the coupling agent that can be used include a silane coupling agent and a titanium coupling agent, and a silane coupling agent is particularly preferably used.

  The toner of the present invention can contain a charge control agent as necessary for the purpose of stabilizing the charge characteristics. As a method of inclusion, there are a method of adding to the inside of toner particles and a method of adding externally. As the charge control agent, a known one can be used, but when added inside, a charge control agent having a low polymerization inhibitory property and substantially free from a solubilized product in an aqueous dispersion medium is particularly preferable. Specific examples of the negative charge control agent include the following compounds. Metallic compounds of aromatic carboxylic acids such as salicylic acid, alkylsalicylic acid, dialkylsalicylic acid, naphthoic acid, dicarboxylic acid; metal salts or metal complexes of azo dyes or azo pigments; polymer type having sulfonic acid or carboxylic acid group in the side chain Compound: Boron compound, urea compound, silicon compound, calixarene. Examples of positive charge control agents include quaternary ammonium salts, polymer compounds having quaternary ammonium salts in the side chain, guanidine compounds, nigrosine compounds, and imidazole compounds.

  The amount of these charge control agents used is determined by the toner production method including the type of binder resin, the presence or absence of other additives, and the dispersion method. Therefore, although it is not uniquely limited, in the case of internal addition, it is preferably in the range of 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the binder resin. Used in In the case of external addition, the amount is preferably 0.005 to 1.0 part by mass, more preferably 0.01 to 0.3 part by mass with respect to 100 parts by mass of the toner.

  The toner of the present invention is preferably externally added with a fluidity improver to improve image quality. As the fluidity improver, inorganic fine powders such as silicate fine powder, titanium oxide, and aluminum oxide are preferably used. These inorganic fine powders are preferably hydrophobized with a hydrophobizing agent such as a silane coupling agent, silicone oil or a mixture thereof.

  The toner of the present invention can be used as it is as a one-component developer or as a two-component developer by mixing with a magnetic carrier. In particular, in the one-component development method, since there are many opportunities for the developer and each member to be in direct contact with each other, each member is easily contaminated by the developer. For this reason, the toner of the present invention, which hardly releases the release agent and hardly contaminates each member, is particularly excellent as a one-component developer. When used as a two-component developer, the average particle size of the carrier to be mixed is preferably 10 to 100 μm, and the toner concentration in the developer is preferably 2 to 15% by mass.

  The glass transition temperature is measured according to ASTM D3418-82 using a differential scanning calorimeter “Q1000” (manufactured by TA Instruments). The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium.

  First, about 5 mg of a sample is precisely weighed in an aluminum pan, and an empty aluminum pan is prepared as a reference pan. In a nitrogen atmosphere, the measurement temperature range is 20 to 140 ° C., the temperature rising rate is 2 ° C./min, and the modulation amplitude is ± 0. Measurement is performed under the conditions of 6 ° C. and a frequency of once / minute.

  From the reversing heat flow curve at the time of temperature rise obtained by measurement, draw a tangent line between the endothermic curve and the front and back baselines, find the midpoint of the straight line connecting the intersections of each tangent line, and this is the glass transition Let it be temperature.

  Hereinafter, the production method of the present invention will be specifically described with reference to examples.

<Synthesis Example 1: Resin fine particle dispersion (a)>
(Production of polyester resin)
The following monomers were charged into a reaction vessel equipped with a stirrer, condenser, thermometer and nitrogen introduction tube, 0.03 parts by mass of tetrabutoxy titanate was added as an esterification catalyst, and the temperature was raised to 220 ° C. in a nitrogen atmosphere. Warmed and reacted for 5 hours with stirring.
Bisphenol A-propylene oxide 2 mol adduct: 49.6 parts by mass Ethylene glycol: 8.9 parts by mass Terephthalic acid: 22.4 parts by mass Isophthalic acid: 15.2 parts by mass 5-sodium sulfoisophthalic acid: 3.9 masses Part

  Next, the reaction was further carried out for 5 hours while reducing the pressure inside the reaction vessel to 5 to 20 mmHg to obtain a polyester resin.

(Preparation of resin fine particle dispersion)
A reaction vessel equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube was charged with 100.0 parts by mass of the obtained polyester resin, 45.0 parts by mass of methyl ethyl ketone, and 45.0 parts by mass of tetrahydrofuran, and heated to a temperature of 80 ° C. And dissolved.

  Next, after stirring, 300.0 parts by mass of ion-exchanged water having a temperature of 80 ° C. is added and dispersed in water, and the resulting aqueous dispersion is transferred to a distillation apparatus and distilled until the fraction temperature reaches 100 ° C. went.

  After cooling, ion-exchanged water was added to the obtained aqueous dispersion to adjust the resin concentration in the dispersion to 20%. This was designated as resin fine particle dispersion (a).

<Synthesis Example 2: Resin fine particle dispersion (b)>
(Production of polyester resin)
In Synthesis Example 1, a reaction was performed in the same manner as in Synthesis Example 1 except that the amount of the monomer charged was changed as follows to obtain a polyester resin.
Bisphenol A-propylene oxide 2 mol adduct: 49.9 parts by mass Ethylene glycol: 9.0 parts by mass Terephthalic acid: 20.5 parts by mass Isophthalic acid: 13.7 parts by mass Trimellitic anhydride: 7.0 parts by mass

(Preparation of resin fine particle dispersion)
In a reaction vessel equipped with a stirrer, condenser, thermometer, and nitrogen introduction tube, 100.0 parts by mass of the obtained polyester resin and 75.0 parts by mass of butyl cellosolve were charged and dissolved by heating to 90 ° C. Until cooled.

  Next, 18.0 parts by mass of a 1 mol / liter aqueous ammonia solution was added and stirred for 30 minutes while maintaining the vapor temperature. Then, 300.0 parts by mass of ion-exchanged water at 70 ° C. was added and dispersed in water. . The obtained aqueous dispersion was transferred to a distillation apparatus and distilled until the fraction temperature reached 100 ° C.

  After cooling, ion-exchanged water was added to the obtained aqueous dispersion to adjust the resin concentration in the dispersion to 20%. This was designated as resin fine particle dispersion (b).

<Synthesis Example 3: Resin fine particle dispersion (c)>
In Synthesis Example 1, a polyester resin aqueous dispersion was obtained in the same manner as in Synthesis Example 1 except that the monomer mixture was changed as follows. This was designated as resin fine particle dispersion (c).
Bisphenol A-propylene oxide 2 mol adduct: 62.4 parts by mass Ethylene glycol: 7.5 parts by mass Terephthalic acid: 12.4 parts by mass Isophthalic acid: 12.3 parts by mass Fumaric acid: 8.8 parts by mass 5-sodium Sulfoisophthalic acid: 5.4 parts by mass

<Synthesis Example 4: Resin fine particle dispersion (d)>
A reaction vessel equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube was charged with 350.0 parts by mass of ion-exchanged water and 0.5 parts by mass of sodium dodecylbenzenesulfonate, and the temperature was raised to 90 ° C. in a nitrogen atmosphere. Then, 8 parts by mass of 2% aqueous hydrogen peroxide solution and 8 parts by mass of 2% aqueous ascorbic acid solution were added.

  Subsequently, the following monomer mixture, aqueous emulsifier solution and aqueous polymerization initiator solution were added dropwise over 5 hours with stirring.

(Monomer)
Styrene: 95.9 parts by weight Methyl methacrylate: 2.3 parts by weight Acrylic acid: 1.8 parts by weight Bromotrichloromethane: 0.5 parts by weight t-dodecyl mercaptan: 0.05 parts by weight

(emulsifier)
Sodium dodecylbenzenesulfonate: 0.3 parts by mass Polyoxyethylene nonylphenyl ether: 0.01 parts by mass Ion exchange water: 20.0 parts by mass

(Polymerization initiator)
2% aqueous hydrogen peroxide solution: 40 parts by mass 2% aqueous ascorbic acid solution: 40 parts by mass

  After dropping, the polymerization reaction was further carried out for 2 hours while maintaining the above temperature, followed by cooling to obtain an aqueous dispersion of styrene / acrylic resin.

  Ion exchange water was added to the obtained aqueous dispersion to adjust the resin concentration in the dispersion to 20%. This was designated as resin fine particle dispersion (d).

  With respect to the resin fine particle dispersions (a) to (d) thus obtained, the glass transition temperature of the resin used in each dispersion was measured by the method described above. With respect to the resin fine particle dispersion (d), a part of the dispersion was washed and dried, and the one taken out as a solid content was measured.

  Moreover, it measured with the following method about the acid value of each resin.

  The acid value is represented by the mass (mg) of potassium hydroxide necessary to neutralize the acid contained in 1 g of the sample. The acid values of the resin fine particle dispersions (a) and (c) having sulfonic acid groups were obtained by measuring the amount of S element in each resin using a fluorescent X-ray analyzer (XRF) and calculating it. It is. Although the acid value of (b) and (d) was measured according to JIS K 0070-1966, specifically, it measures according to the following procedures.

(1) Preparation of Reagent 1.0 g of phenolphthalein is dissolved in 90 ml of ethyl alcohol (95% by volume), and ion exchange water is added to make 100 ml to obtain a “phenolphthalein solution”.

  7 g of special grade potassium hydroxide is dissolved in 5 ml of water, and ethyl alcohol (95% by volume) is added to make 1 l. In order to avoid contact with carbon dioxide, etc., it is placed in an alkali-resistant container and left for 3 days, followed by filtration to obtain a “potassium hydroxide solution”. The obtained potassium hydroxide solution is stored in an alkali-resistant container. The orientation is performed according to JIS K 0070-1996.

(2) Operation (A) Main test 2.0 g of the sample is precisely weighed into a 200 ml Erlenmeyer flask, and 100 ml of a mixed solution of toluene / ethanol (2: 1) is added and dissolved over 5 hours. Subsequently, several drops of the phenolphthalein solution is added as an indicator, and titration is performed using the potassium hydroxide solution. The end point of titration is when the light red color of the indicator lasts for about 30 seconds.

(B) Blank test Titration is performed in the same manner as above except that no sample is used (that is, only a mixed solution of toluene / ethanol (2: 1) is used).

(3) The acid value is calculated by substituting the obtained result into the following formula.
A = [(BC) × f × 5.61] / S

  Here, A: acid value (mgKOH / g), B: addition amount (ml) of a potassium hydroxide solution in a blank test, C: addition amount (ml) of a potassium hydroxide solution in this test, f: potassium hydroxide Solution factor, S: sample (g).

  The results are summarized in Table 1 respectively.

<Synthesis Example 5: Core Particle Dispersion (A)>
(Preparation of pigment dispersion paste)
Styrene: 212.9 parts by mass Cu phthalocyanine (Pigment Blue 15: 3): 19.7 parts by mass After sufficiently premixing the above materials in a container, an attritor (manufactured by Mitsui Miike Chemical Co., Ltd.) is maintained at a temperature of 20 ° C. or less. ) Was uniformly dispersed and mixed for about 4 hours to prepare a pigment dispersion paste.

(Preparation of core particle dispersion)
Into 1152.0 parts by mass of ion-exchanged water, 390.0 parts by mass of 0.1 mol / liter-Na ₃ PO ₄ aqueous solution was added and stirred at a temperature of 60 ° C. using CLEARMIX (M Technique Co., Ltd.). After heating, 58.0 parts by mass of 1.0 mol / liter-CaCl ₂ aqueous solution was added and stirring was continued to prepare an aqueous medium containing a dispersion stabilizer composed of Ca ₃ (PO ₄ ) ₂ .

On the other hand, the following materials were added to the pigment dispersion paste and dispersed and mixed using an attritor (manufactured by Mitsui Miike Chemical Industries) to prepare a polymerizable monomer composition.
n-Butyl acrylate: 114.7 parts by mass Amorphous polyester: 15.1 parts by mass (polycondensation product of propylene oxide-modified bisphenol A and isophthalic acid, glass transition temperature Tg = 58 ° C., Mw = 7800, acid value 13 )
Aluminum salicylate compound: 3.1 parts by mass (Bontron E-88: manufactured by Orient Chemical Co., Ltd.)
Divinylbenzene: 0.049 parts by mass The monomer composition was heated to 60 ° C., and 32.8 parts by mass of paraffin wax (mp = 70 ° C.) was added thereto and mixed and dissolved.

  Next, 7.8 parts by mass of 2,2'-azobis (2,4-dimethylvaleronitrile) was further added and dissolved as a polymerization initiator.

  This was put into the aqueous medium, and granulated by stirring for 10 minutes at 10,000 rpm in a nitrogen atmosphere at a temperature of 60 ° C. using CLEARMIX (M Technique Co., Ltd.).

  The obtained suspension was further reacted at a temperature of 60 ° C. for 5 hours while stirring with a paddle stirring blade, and the temperature was raised to 75 ° C. and maintained for 5 hours to carry out polymerization. Next, distillation was performed for 2 hours under a temperature condition of 75 ° C. under reduced pressure to remove the remaining styrene.

  After the completion of the polymerization, the obtained dispersion of polymer particles was cooled, and ion exchange water was added to adjust the concentration of polymer particles in the dispersion to 20%. This was designated as core particle dispersion (A).

<Synthesis Example 6: Core particle dispersion (B)>
In Synthesis Example 5, the same procedure as in Synthesis Example 5 was conducted, except that 212.7 parts by mass of styrene was changed to 173.6 parts by mass, and 114.9 parts by mass of n-butyl acrylate was changed to 154.1 parts by mass. A particle dispersion (B) was prepared.

<Synthesis Example 7: Core particle dispersion (C)>
In Synthesis Example 5, a core was obtained in the same manner as in Synthesis Example 5 except that 212.7 parts by mass of styrene was changed to 229.2 parts by mass, and 114.9 parts by mass of n-butyl acrylate was changed to 98.3 parts by mass. A particle dispersion (C) was prepared.

<Synthesis Example 8: Core particle dispersion (D)>
A core particle dispersion (D) is prepared in the same manner as in Synthesis Example 5 except that 32.8 parts by mass of paraffin wax (mp = 70 ° C.) is changed to 16.4 parts by mass in Synthesis Example 5. did.

<Synthesis Example 9: Core Particle Dispersion (E)>
A core particle dispersion (E) was prepared in the same manner as in Synthesis Example 5 except that 32.8 parts by mass of paraffin wax (mp = 70 ° C.) was changed to 91.7 parts by mass in Synthesis Example 5. did.

<Synthesis Example 10: Core particle dispersion (F)>
In Synthesis Example 5, the same procedure as in Synthesis Example 5 was used, except that an ester wax having a stearyl stearate structure (mp = 60 ° C.) was used instead of the paraffin wax (mp = 70 ° C.). Thus, a core particle dispersion (F) was prepared.

<Synthesis Example 11: Core particle dispersion (G)>
A core particle dispersion (G) was prepared in the same manner as in Synthesis Example 5 except that the distillation temperature was changed from 75 ° C. to 85 ° C. and the distillation time was changed from 2 hours to 5 hours in Synthesis Example 5.

<Synthesis Example 12: Core particle dispersion (H)>
A core particle dispersion (H) was prepared in the same manner as in Synthesis Example 5 except that 32.8 parts by mass of paraffin wax (mp = 70 ° C.) was changed to 3.3 parts by mass in Synthesis Example 5. did.

<Synthesis Example 13: Core Particle Dispersion (I)>
A core particle dispersion (I) is prepared in the same manner as in Synthesis Example 5 except that 32.8 parts by mass of paraffin wax (mp = 70 ° C.) is changed to 114.7 parts by mass in Synthesis Example 5. did.

  For the core particle dispersions (A) to (I) thus obtained, a part of each dispersion is withdrawn, diluted hydrochloric acid is added until the pH is 1.5, filtered, washed with water and dried to obtain each powder particle. Obtained.

  The glass transition temperature of each powder particle thus obtained and the methanol concentration (volume%) at a light transmittance of 50% in a wettability test for a methanol / water mixed solvent were measured.

  The results are summarized in Table 2 respectively. The amount of the release agent added is shown in parts by mass with respect to the binder resin. Further, the methanol concentration (%) in the table is the methanol concentration (volume%) when the light transmittance is 50% in the wettability test of each powder particle with respect to the methanol / water mixed solvent.

<Example 1>
(Production of toner particles)
The fine resin particle dispersion (a) 25.0 obtained in Synthesis Example 1 was added to 500.0 parts by mass (solid content 100.0 parts by mass) of the core particle dispersion (A) obtained in Synthesis Example 5 with stirring. After adding mass part (solid content 5.0 mass part) and continuing stirring for 30 minutes, it heated up at the temperature of 55 degreeC.

  Next, a 0.2 mol / liter hydrochloric acid aqueous solution was added dropwise so that the pH of the dispersion decreased by 0.1 per minute, and the pH of the dispersion was adjusted to 1.5.

  Stirring was continued for another 2 hours while maintaining the above temperature, and then with stirring, a 1 mol / liter sodium hydroxide aqueous solution was added at a dropping rate of 10.0 parts by mass / min, and the pH of the dispersion was 7.2. It was dripped until it became.

  This dispersion was heated to 70 ° C., which is higher than the glass transition temperature of the resin fine particles, and further stirred for 2 hours. The dispersion was cooled to 20 ° C., diluted hydrochloric acid was added until the pH reached 1.5, the mixture was filtered, washed with water and dried to obtain toner particles.

(Production of toner)
Hydrophobic silica fine powder having a primary particle size of 12 nm and a BET specific surface area of 120 m ² / g, which is obtained by treating 100 parts by mass of silica fine powder with 10 parts by mass of hexamethyldisilazane and further with 10 parts by mass of silicone oil. The body was prepared. Next, 1.0 part by mass of the hydrophobic silica fine powder was added to 100.0 parts by mass of the toner particles, and mixed using a Henschel mixer (manufactured by Mitsui Miike Chemical Industries). Thus, the toner of the present invention was produced.

<Example 2>
A toner of the present invention was produced in the same manner as in Example 1 except that instead of the core particle dispersion (A), the core particle dispersion (B) was used.

<Example 3>
A toner of the present invention was produced in the same manner as in Example 1 except that instead of the core particle dispersion (A), the core particle dispersion (C) was used.

<Example 4>
In Example 1, except that the addition amount of the resin fine particle dispersion (a) was changed from 25.0 parts by mass (solid content 5.0 parts by mass) to 10.0 parts by mass (solid content 2.0 parts by mass). The toner of the present invention was produced in the same manner as in Example 1.

<Example 5>
In Example 1, except that the addition amount of the resin fine particle dispersion (a) was changed from 25.0 parts by mass (solid content 5.0 parts by mass) to 50.0 parts by mass (solid content 10.0 parts by mass). The toner of the present invention was produced in the same manner as in Example 1.

<Example 6>
A toner of the present invention was produced in the same manner as in Example 1 except that instead of the core particle dispersion (A), the core particle dispersion (D) was used.

<Example 7>
A toner of the present invention was produced in the same manner as in Example 1 except that the core particle dispersion (E) was used instead of the core particle dispersion (A).

<Example 8>
A toner of the present invention was produced in the same manner as in Example 1 except that the core particle dispersion (F) was used instead of the core particle dispersion (A).

<Example 9>
In Example 1, the toner of the present invention was produced in the same manner as in Example 1 except that the core particle dispersion (G) was used instead of the core particle dispersion (A).

<Comparative Example 1>
A toner of a comparative example was produced in the same manner as in Example 1 except that the resin fine particle dispersion (b) was used in place of the resin fine particle dispersion (a).

<Comparative example 2>
A toner of Comparative Example was produced in the same manner as in Example 1 except that the resin fine particle dispersion (c) was used in place of the resin fine particle dispersion (a).

<Comparative Example 3>
A toner of a comparative example was produced in the same manner as in Example 1 except that the resin fine particle dispersion (d) was used instead of the resin fine particle dispersion (a).

<Comparative example 4>
In Example 1, except that the addition amount of the resin fine particle dispersion (a) was changed from 25.0 parts by mass (solid content 5.0 parts by mass) to 75.0 parts by mass (solid content 15.0 parts by mass). In the same manner as in Example 1, a comparative toner was produced.

<Comparative Example 5>
A toner of a comparative example was produced in the same manner as in Example 1 except that the core particle dispersion (H) was used instead of the core particle dispersion (A).

<Comparative Example 6>
A toner of a comparative example was produced in the same manner as in Example 1 except that instead of the core particle dispersion (A) in Example 1, the core particle dispersion (I) was used.

<Comparative Example 7>
(Production of toner particles)
To the core particle dispersion (C) obtained in Synthesis Example 7, diluted hydrochloric acid was added to dissolve the dispersion stabilizer, followed by filtration, washing with water and drying to obtain toner particles.

(Production of toner)
A hydrophobic silica fine powder was externally added to the obtained toner particles in the same manner as in Example 1 to prepare a comparative toner.

<Comparative Example 8>
(Production of toner particles)
Diluted hydrochloric acid was added to the core particle dispersion (A) obtained in Synthesis Example 5 until the pH reached 1.5 to dissolve the dispersion stabilizer, followed by filtration, washing with water and drying to obtain powder particles.

  Subsequently, 60.0 parts by mass (12.0 parts by mass of solid content) of the resin fine particle dispersion (a) obtained in Synthesis Example 1 was added to 400.0 parts by mass of ion-exchanged water, and the powder was mixed while stirring. 100.0 parts by mass of particles were gradually added and dispersed uniformly.

  A 1 mol / liter hydrochloric acid aqueous solution was added thereto to adjust the pH of the dispersion to 1.5, and after stirring for 1 hour, the temperature of the dispersion was raised to 55 ° C. and further stirred for 2 hours. It was.

  Thereafter, the mixture was cooled, filtered, washed with water and dried to obtain toner particles.

(Production of toner)
A hydrophobic silica fine powder was externally added to the obtained toner particles in the same manner as in Example 1 to prepare a comparative toner.

<Comparative Example 9>
(Production of toner particles)
The fine resin particle dispersion (a) 25.0 obtained in Synthesis Example 1 was added to 500.0 parts by mass (solid content 100.0 parts by mass) of the core particle dispersion (A) obtained in Synthesis Example 5 with stirring. After adding mass part (solid content 5.0 mass part) and continuing stirring for 30 minutes, it heated up at the temperature of 55 degreeC.

  Next, the temperature of the dispersion was raised to 70 ° C., and further stirred for 2 hours, then cooled, filtered, washed with water and dried to obtain toner particles.

(Production of toner)
A hydrophobic silica fine powder was externally added to the obtained toner particles in the same manner as in Example 1 to prepare a comparative toner.

For the toner particles used in the toners obtained in Examples 1 to 9 and Comparative Examples 1 to 9, the methanol concentration V when the light transmittance measured at a temperature of 25.0 ° C. is 50%. _ini (% by volume) was measured. Further, the toner particles used for each toner were heat-treated at a temperature range of 35.0 to 60.0 ° C. under a temperature condition of every 2.5 ° C. for 3 days, and similarly, methanol concentration V _35.0 , _V37.5 , _V40.0 , _V42.5 , _V45.0 , _V47.5 , _V50.0 , _V52.5 , _V55.0 , _V57.5 , _V60.0 (volume%) were measured.

The amount of change between the methanol concentrations V _{35.0 to} V _60.0 and the methanol concentration V _{ini at} each temperature is obtained, and each amount of change is plotted on the coordinates where the vertical axis is the change amount and the horizontal axis is the heat treatment temperature. A graph was created by connecting the plots with straight lines. FIG. 2 shows graphs created for Example 1 and Comparative Example 7.

  Further, from the obtained graph, the heat treatment temperature when the change amount was 10% was determined as T10 (° C.), and the heat treatment temperature when the change amount was 30% was determined as T30 (° C.).

From the above results, V _ini (%), T10-Tg1 (° C.), and T30-T10 (° C.) were determined for each toner particle. The results are summarized in Table 3.

  Moreover, evaluation of blocking resistance, low-temperature fixability, and durability was performed according to the points described below. The results are summarized in Table 4.

<Blocking resistance>
10 g of toner is weighed into a 100 ml capacity polycup and placed in a thermostat with an internal temperature of 50 ° C. and left for 7 days. Thereafter, the polycup is taken out, and the state change of the toner inside is visually evaluated. Judgment criteria are as follows.
A: No change B: There is an aggregate, but loosens immediately C: A little aggregate, but loosens when shocked D: Many aggregates, not easily loosened E: Not loosened at all

<Low-temperature fixability>
A two-component developer is prepared by mixing toner and a magnetic fine particle-dispersed resin carrier (average particle diameter 35 μm) surface-coated with a silicone resin so that the toner concentration is 7.0% by mass.

  Next, the two-component developer is allowed to stand for 7 days at high temperature and high humidity (30 ° C./80%), and then left for another 3 days at room temperature and normal humidity (23 ° C./60%). Reset.

As a test machine, a commercially available full-color copying machine (CLC-700, manufactured by Canon Inc.) was used, and an unfixed toner image on the image receiving paper (80 g / m ² ) (toner applied amount per unit area of 0. 0). 6 mg / cm ² ).

  The fixing test is performed using a fixing unit which is removed from the copying machine and modified so that the fixing temperature can be adjusted. The specific evaluation method is as follows.

  In a normal temperature and humidity environment (23 ° C, 60% RH), the process speed is set to 180 mm / s, the initial temperature is set to 120 ° C, and the set temperature is sequentially raised by 5 ° C, and the unfixed state at each temperature. Fix the image.

In the present invention, the low-temperature fixability is determined by rubbing when the low-temperature offset is not observed and the obtained fixed image is rubbed back with sylbon paper applied with a load of 4.9 kPa (50 g / cm ² ). The temperature at which the density decrease rate before and after was 5% or less was defined as the low temperature side fixing start point. The evaluation criteria for the low-temperature fixing performance are as follows.
A: The low temperature side starting point is 120 ° C. (low temperature fixing performance is particularly excellent)
B: low temperature side starting point is 125 ° C. (low temperature fixing performance is good)
C: Starting point on the low temperature side is 130 ° C. (low temperature fixing performance is at a level where there is no problem)
D: The low temperature side starting point is 135 ° C. (low temperature fixing performance is slightly inferior)
E: Starting point on the low temperature side is 140 ° C. (low temperature fixing performance is inferior)

<Durability>
A commercially available color laser printer (LBP-5900SE, manufactured by Canon) was used to take out the toner from the cyan cartridge, and 150 g of the prepared toner was filled therein. The cartridge is installed in the cyan station of the printer, and 5000 sheets of a 2% printing rate chart are continuously obtained using image receiving paper (Canon office planner 64 g / m ² ) under normal temperature and humidity (23 ° C., 60% RH). And painted.

The image density before and after the image was measured with a Macbeth densitometer, and the decrease in the image density was evaluated according to the following evaluation criteria.
A: Image density reduction after image output is less than 5% (image density reduction is very small)
B: Image density reduction after image output is greater than 5% and less than 10% (less decrease in image density)
C: Decrease in image density after image output is greater than 10% and less than 15% (no problem in reducing image density)
D: The decrease in image density after image output is greater than 15% and less than 20% (the decrease in image density is large)
E: The decrease in image density after image output is greater than 20% (the decrease in image density is very large)

The obtained image quality was evaluated according to the following evaluation criteria.
A: Image defect does not occur and image quality is particularly excellent (durability is particularly excellent)
B: No image defect and excellent image quality (excellent durability)
C: Image defect does not occur and image quality is good (durability is good)
D: Image defect does not occur, but image quality is inferior to C (durability is inferior to C)
E: Image defect occurs or image quality is inferior to D (durability is inferior to D)

Further, the toner carrying member was removed after 5,000 images were printed, and after the toner was wiped off, the contamination state of the surface was observed with a microscope, and the determination was made according to the following criteria.
A: No particular contamination is observed B: Very little deposit C: Some deposits are seen D: Many deposits are seen E: Toner fusion is seen

  The results are summarized in Table 4.

  From Table 4, the toners of the examples were excellent in blocking resistance and low-temperature fixability and excellent in durability.

  Comparing Example 1 and Example 2, if the toner has the characteristics of the present invention, even when the glass transition temperature of the core particles is 30 ° C., the exudation of the release agent is suppressed and excellent durability is achieved. It can be seen that it can exert its properties. From the results of Example 3, it can be seen that although the fixing temperature increases according to the glass transition temperature of the core particles, sufficient low-temperature fixing property, blocking resistance and durability can be achieved at the same time.

  From the results of Examples 4 and 5, it can be seen that good blocking resistance, low-temperature fixability and durability can be obtained even when the coating amount is slightly small or slightly large.

  From the results of Example 6, it can be seen that when the amount of the release agent added is small, the fixability is affected, but a sufficiently good fixability can be obtained.

  Further, from the results of Examples 7 to 9, a slight deterioration in image quality was observed when the release agent was difficult to be contained in the core particles, but sufficiently good blocking resistance, low temperature fixability and durability were observed. It turns out that it is obtained.

  From the results of Example 1 and Comparative Example 1, it can be seen that when the resin fine particles used as the coating layer have a sulfonic acid group, a more uniform and dense coating layer can be formed.

  From the results of Comparative Examples 2 to 6, when the conditions of the coating layer and the release agent deviate from the conditions specified by the present invention, the characteristics of the present invention cannot be obtained, and the anti-blocking property, the low-temperature fixability and the durability are not obtained. It turns out that coexistence cannot be achieved.

  From the results of Comparative Example 7, it can be seen that the characteristics of the present invention cannot be obtained when the coating layer is not formed.

  From the results of Comparative Examples 8 and 9, it can be seen that when different coating layer forming means are used, various performances are significantly reduced.

It is a figure which shows the relationship between the methanol density | concentration obtained by the wettability test with respect to the methanol / water mixed solvent of this invention, and the light transmittance. In the wettability test of the toner particles in a methanol / water mixed solvent, the methanol concentration when the light transmittance measured at a temperature of 25.0 ° C. is 50%, and the toner particles at a temperature of 35.0 to 60.degree. It is a figure which shows the relationship between the variation | change_quantity of the methanol concentration in each temperature, and heat processing temperature when methanol concentration is measured on the conditions of temperature 25.0 degreeC after heat-processing for 3 days in the range of 0 degreeC.

Claims (7)

A toner having toner particles having a core-shell structure in which a coating layer is formed on the surface of core particles containing at least a binder resin , a colorant, and a release agent,
The glass transition temperature Tg1 (° C.) of the core particles is 20 to 55 ° C., and the glass transition temperature Tg2 (° C.) of the coating layer is 60 to 100 ° C.
In the wettability test of the toner particles to a mixed solvent of methanol / water,
i) The methanol concentration V _ini (volume%) when the light transmittance measured at a temperature of 25.0 ° C. is 50% is 0.5 to 20.0%,
ii) In the temperature range of 35.0 to 60.0 ° C., the toner particles are heated for 3 days under a temperature condition changed from 35.0 ° C. to 2.5 ° C. , and then the temperature is 25.0 ° C. Then, a wettability test on a mixed solvent of methanol / water was conducted, and methanol concentrations V _35.0 , V _37.5 , V _40.0 , V _42.5 , V _45.0 , V _47.5 , V _50.0 , V when the light transmittance was 50% _52.5, V _55.0, measured V _57.5, V _60.0 (volume%), respectively, by subtracting the methanol concentration or al methanol concentration V _ini obtains a variation in the temperature, the variation amount and the vertical axis, horizontal axis heated plotted on the processing temperature coordinates, in graph form by connecting each plot a straight line, the temperature at which the change amount of 10% and T10 (° C.), when the amount of change is 30% When the temperature is T30 (° C.), T10 ° C.) and T30 (° C.) The following equation (1) and (2)
T10 (° C)> Tg1 (° C) (1)
T30 (° C.) − T 10 (° C.) <5.0 (° C.) (2)
A toner characterized by satisfying Temperature T10 at which the amount of change is 10% (° C.) and the temperature T30 at which the amount of change is 30% (° C.) The following equation (3)
T30 (° C.) − T 10 (° C.) <3.0 (° C.) (3)
The toner according to claim 1, wherein: The covering layer, toner according to claim 1 or 2, characterized in that it contains a self-dispersing resin particles having a carboxyl group and / or scan sulfonic acid group.   The toner according to claim 3, wherein the coating layer contains self-dispersing resin fine particles having a sulfonic acid group.   The toner according to claim 1, wherein the coating layer has a coating amount of 1.0 to 10.0% by mass ratio with respect to the core particles.   The toner according to claim 1, wherein the content of the release agent is 3.0 to 30.0% by mass ratio with respect to the binder resin. The core particle is obtained by dispersing a polymerizable monomer composition containing at least a polymerizable monomer , a colorant and a release agent in an aqueous medium and polymerizing the polymerizable monomer. The toner according to claim 1, wherein the toner is a toner.

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