JP2008158197A - Toner for electrostatic latent image development, method for manufacturing the toner, developer for electrostatic latent image development, and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner for electrostatic latent image development capable of forming a stable image for long-term use, a developer for electrostatic latent image development containing the above toner, an image forming method using the developer, and a method for manufacturing the toner for electrostatic latent image development excellent in manufacturing stability. <P>SOLUTION: The toner for electrostatic latent image development contains, at least, a binder resin containing an amorphous polyester resin and a crystalline polyester resin, a colorant and a release agent, and is characterized in that: the ratio of the volume average particle size distribution index to the number average particle size distribution index is 0.95 or more; the weight average molecular weight of the binder resin is 15,000 to 60,000; the ratio of the weight average molecular weight to the number average molecular weight of the binder resin is 3.5 to 7.0; the shape factor SF1 is 110 to 140; and the average shape factor index is 1.08 or less. The present invention also discloses a method for manufacturing the toner, a developer for electrostatic latent image development using the toner, and an image forming method using the developer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a toner for developing an electrostatic latent image and a method for producing the same, a developer for developing an electrostatic latent image, and an image forming method.

  A method of visualizing image information through an electrostatic latent image by electrophotography or the like is currently used in various fields. In electrophotography, image information is formed as an electrostatic latent image on the surface of a latent image carrier (photoreceptor) by charging and exposure processes, and a toner image is developed on the surface of the photoreceptor using a developer containing toner. The toner image is visualized as an image through a transfer process for transferring the toner image to the intermediate transfer member and a fixing process for fixing the toner image to the surface of the recording medium.

  There are two types of developers used in electrophotography, a two-component developer composed of a toner and a carrier and a one-component developer using a magnetic toner or a non-magnetic toner alone. The toner contained in these developers is usually prepared by melt-kneading a thermoplastic resin together with a release agent such as pigment, charge control agent, wax, etc., finely pulverizing it after cooling, and further classifying it. Has been. To the toner thus prepared, inorganic and organic particles for improving fluidity and cleaning properties are further added to the toner particle surfaces as necessary.

In recent years, color image formation by full-color electrophotography, which has been widely used, is generally performed by using four color toners consisting of three subtractive primary colors, yellow, magenta, and cyan, and black toner. It is a reproduction.
In a general full-color electrophotographic method, first, an original (image information) is color-separated into yellow, magenta, cyan, and black, and an electrostatic latent image is formed on the surface of the photoreceptor for each color. At this time, the electrostatic latent image formed for each color is developed using a developer containing toner of each color to form a toner image, and the toner image is transferred to the surface of the recording medium through a transfer process. A series of steps including the formation of the electrostatic latent image and the transfer of the toner image to the surface of the recording medium are sequentially performed for each color, and the toner images of each color are superimposed on the same recording medium surface so as to match the image information. To be transcribed. The full-color toner image obtained by transferring the toner images of the respective colors onto the surface of the recording medium in this way is formed as a full-color image through a fixing process. The point that several kinds of toners having different colors are superposed is a big difference between the black and white electrophotographic method and the full color electrophotographic method.

  Conventional fixing methods for electrostatic latent image developing toner (electrophotographic toner) include a pressure fixing method using only a pressure roll at room temperature, a contact heating fixing method using a heating roll, and an oven fixing method using oven heating. Non-contact fixing methods such as flash fixing methods using xenon lamps, electromagnetic wave fixing methods using microwaves, etc., solvent fixing methods using solvent vapor, etc. are reliable, but oven fixing methods using heat and contact heating type fixing methods are reliable. Mainly used from the aspect of safety and safety. In particular, the contact heating type fixing method using a heating roll, a belt, or the like is usually composed of a heating roll or belt provided with a heating source and a pressure roll or belt, and a toner image surface of a fixing sheet is placed on the heating roll or belt surface. Fixing is carried out by passing through pressure contact. Since the surface of the heated roll or belt and the toner image surface of the fixing sheet are in direct contact, the heat efficiency is effective and fixing can be performed quickly. Have been widely adopted.

  In these thermal fixing methods, the time from when the power is turned on until the temperature of the fixing device quickly rises to the operating temperature and becomes ready for fixing, so-called warm-up time is shortened, and in order to reduce energy consumption It is desired to fix at a low temperature. Particularly in recent years, in order to thoroughly save energy, it is desired to stop energization of the fixing machine except during use. For this reason, the fixing machine temperature needs to reach a fixable temperature in a short time together with energization. That is, fixing at a lower temperature is desired. In addition, by reducing the fixing temperature, it is possible to increase the output speed even with the same power consumption, and in the contact heating type fixing method, it is possible to extend the life of a fixing member such as a heating roll. . However, in the conventional method, lowering the fixing temperature of the toner also lowers the glass transition temperature of the toner particles at the same time, making it difficult to achieve both toner storage stability. Therefore, in order to achieve both low temperature fixing and toner storage stability, it is necessary to have a so-called sharp melt property in which the viscosity of the toner rapidly decreases in a high temperature region while maintaining the glass transition temperature of the toner at a higher temperature. is there.

  However, since the resin used for the toner, that is, the amorphous resin usually has a certain range of glass transition temperature, molecular weight, etc., in order to obtain the above-mentioned sharp melt property, the resin composition and molecular weight are extremely aligned. Although it is necessary, in order to obtain the resin, it is necessary to adjust the molecular weight of the resin by using a special production method or by treating the resin with chromatography or the like. In this case, an unnecessary resin is generated, which is not preferable from the viewpoint of environmental protection in recent years.

  In order to realize such low-temperature fixability, a method using a crystalline resin as a binder resin has been studied (for example, see Patent Documents 1 to 3). By using a crystalline resin, the hardness of the toner is maintained below the melting point of the crystal, and when the melting point is exceeded, the viscosity rapidly decreases as the crystal melts, thereby achieving low-temperature fixing. However, the above disclosed technique, for example, the technique disclosed in Patent Document 1, has a problem in reliability of powder and images because the melting point of the crystalline resin is 62 to 66 ° C. and the melting point is slightly too low. Further, the crystalline resins described in Patent Documents 2 and 3 have a problem that the fixing performance to paper is not sufficient.

  Examples of the crystalline resin that is expected to improve the fixability to paper include polyester resins. An example in which a crystalline polyester resin is used for toner is disclosed (for example, see Patent Document 4). This is a method in which an amorphous polyester having a glass transition temperature of 40 ° C. or higher and a crystalline polyester having a melting point of 130 ° C. to 200 ° C. are mixed. However, although this method has excellent pulverization properties and blocking resistance, the crystalline polyester resin has a high melting point, so that it cannot achieve low-temperature fixability that is higher than conventional ones. In addition, there is an example in which a resin having a melting point of a crystalline resin of 110 ° C. or lower is used, and an amorphous resin is mixed to be used as a toner (for example, see Patent Document 5). However, when an amorphous resin is mixed with a crystalline resin, the melting point of the toner is lowered, and toner blocking and image storage stability are deteriorated.

  In recent years, from the viewpoint of environmental protection, technology has shifted from the conventional non-contact charging / transfer method using corona discharge to the contact charging method and contact transfer method using an electrostatic latent image carrier contact member. I am doing. In the contact charging method or the contact transfer method, a conductive elastic roller is brought into contact with the electrostatic latent image holding member, the electrostatic latent image holding member is charged while applying a voltage to the conductive elastic roller, and then exposed ( After the toner image is formed by the latent image forming step) and the developing step, the toner image is transferred to the surface of the intermediate transfer member while pressing the intermediate transfer member to which a voltage is applied to the electrostatic latent image holding member. Further, while pressing another conductive elastic roller to which a voltage is applied to the intermediate transfer member, a recording medium such as paper is passed between the intermediate transfer member and the conductive elastic roller to transfer the toner image to the recording medium. Thereafter, a fixed image is obtained through a fixing step.

  However, in such a transfer system, an intermediate transfer member such as an intermediate transfer member is brought into contact with the electrostatic latent image holding member at the time of transfer, so that the toner image formed on the electrostatic latent image holding member is transferred to the intermediate transfer member. When the toner image is transferred to the toner image, the toner image is pressed and partial transfer failure occurs.

  In addition, when the transfer from the electrostatic latent image holding member to the intermediate transfer member is not complete and toner remains on the surface of the electrostatic latent image holding member, the residual toner is pressed against the electrostatic latent image holding member. It passes through the nip with the conductive elastic roller. If residual toner exists between the electrostatic latent image carrier and the conductive elastic roller, uniform charging cannot be realized on the surface of the electrostatic latent image carrier, and the electrostatic latent image on the electrostatic latent image carrier is Disturbed and causes image defects.

Due to the demand for higher image quality in the full-color image, as the diameter of the toner is reduced, the adhesion of the toner to the electrostatic latent image holding member becomes larger in the transfer process than the Coulomb force applied to the toner particles. There was a tendency that the residual toner (residual toner) increased and the charging failure of the electrostatic latent image holding member accelerated.
For the purpose of preventing charging failure of the electrostatic latent image holding body, a cleaning means is provided between the contact of the electrostatic latent image holding body with the intermediate transfer member and the contact of the electrostatic latent image holding body with the conductive elastic roller. Is provided. The residual toner is firmly fixed to the surface of the electrostatic latent image holding member as a result of the pressure contact of the toner when passing between the electrostatic latent image holding member and the intermediate transfer member.

  As a cleaning method for removing the adhered residual toner from the electrostatic latent image holding member, a blade cleaning method in which the elastic blade is strongly pressed against the electrostatic latent image holding member for removal is suitable from the viewpoint of cleaning ability. It is considered and is generally used. However, the cleaning performance by the blade is greatly influenced by the toner shape, and there is a problem that the spherical toner is difficult to clean.

On the other hand, in addition to the introduction of new mechanisms in image forming apparatuses and optimization of image forming conditions, the development and adoption of technology that can produce color toners with a narrow particle size distribution will also be applied to the surface of recording media. There is a history that the formation of a homogeneous transfer image and a stable transfer rate have been achieved, and the performance of the color toner has been remarkably improved. As one method for improving such a color toner, a toner is formed by polymerizing using a solution in which an oil phase in which a monomer and a colorant as resin raw materials are dissolved is dispersed in an aqueous phase. Thus, there has been proposed a toner manufacturing method capable of narrowly controlling the particle size distribution by a polymerization reaction without classifying the toner obtained by polymerization as in the prior art.
In addition to this, as a means for enabling intentional control of the toner shape and its surface structure, a toner production method by an emulsion polymerization aggregation method has been proposed (see, for example, Patent Document 6 or 7). In general, a binder resin particle dispersion is prepared by emulsion polymerization or the like, and on the other hand, a colorant dispersion in which a colorant is dispersed in a solvent is prepared, and these are mixed to form an aggregate substantially corresponding to a toner particle diameter. Is formed, and this is heated and fused to obtain a toner.

  In addition, since the polyester resin is synthesized by a polycondensation reaction, it is extremely difficult to obtain an emulsified polyester resin by using emulsion polymerization at the time of synthesis. For this reason, there is a method for preparing an emulsion by performing a dispersion treatment. Taken. Conventionally, as one of methods for producing an electrophotographic toner, an emulsion aggregation method has been proposed (see, for example, Patent Documents 8 to 10). In this emulsion aggregation method, a resin dispersion is prepared from a bulk resin by a method such as emulsion polymerization or dispersion emulsification, while a colorant particle dispersion in which a colorant is dispersed in a solvent is prepared and mixed. To do. The particles in the resin dispersion are desired to have a uniform and fine particle size. Subsequently, the particles in the mixed solution are aggregated to obtain aggregated particles, and then the aggregated particles are thermally fused to obtain an electrophotographic toner. According to this emulsion aggregation method, it is possible to arbitrarily control the shape of toner particles from an indeterminate shape to a spherical shape by adjusting the heating temperature at the time of fusion.

  This toner manufacturing method is not only easy to control the narrow particle size distribution effective for obtaining high transferability, but also from the principle of granulation in which aggregates are formed from the particles in the dispersion. This is advantageous for the controllability of the content of the release agent contained in the toner, the control of the toner shape, and particularly the production of a toner having a small particle diameter. When image formation is performed using a toner having a small particle diameter obtained by such a manufacturing method, not only high-definition image quality is provided, but also the toner consumption is suppressed, so It is also possible to reduce the image forming cost.

However, when the crystalline resin is used in the toner production method by this emulsion aggregation method, if the melting point of the crystalline resin is as low as 90 ° C. or less, the speed is very high in the melting and coalescence process, and the shape factor is 110. It is difficult to control the shape to about ~ 140. In addition, this situation does not change simply by using an amorphous resin together with a crystalline resin. Although it is disclosed that a toner containing a crystalline resin as a main component is prepared by an emulsion aggregation method (see, for example, Patent Document 11), this is effective for making a spherical toner, but the toner shape is indefinite. It is difficult to make. Further, a toner is disclosed in which a shell layer made of an amorphous resin is provided on core particles mainly composed of a crystalline resin, and the shape of the particles is a spindle shape (see, for example, Patent Document 12). Although the shape can be averaged into a spindle shape with a dynamic share, its shape factor distribution is wide and it is insufficient for essential shape control. For this reason, problems such as streaks during development occur due to a minute charge amount difference caused by toner particles or a charge amount difference caused by toner deformation caused by stirring with a carrier. In addition, for the purpose of achieving both high glossiness of the image to be formed and OHP transparency, an invention has been disclosed in which the binder resin molecular weight is within a certain range, the molecular weight distribution is narrowed, and the toner shape distribution is within a certain range. However, when a crystalline resin is contained as a resin, for example, such a molecular weight distribution uniformly controls the shape of the toner to be indefinite and suppresses the shape change with time. That is inadequate.
Japanese Patent Publication No. 56-13943 Japanese Examined Patent Publication No.62-39428 Japanese Patent Publication No. 63-25335 Japanese Examined Patent Publication No.62-39428 Japanese Patent Publication No. 4-30014 Japanese Patent Laid-Open No. 63-282275 JP-A-6-250439 Japanese Patent Laid-Open No. 63-282275 JP-A-6-250439 JP 2002-351140 A JP 2003-167380 A JP 2005-227672 A JP 2003-241425 A

The present invention relates to a toner for developing an electrostatic latent image, a method for producing the same, and a development for developing an electrostatic latent image, which solves the problem that developability deteriorates over time with respect to a change in charging property due to a foreign matter adhering to a photoreceptor. The present invention provides an agent and an image forming method.
That is, an object of the present invention is to develop an electrostatic latent image developing toner capable of forming a stable image in long-term use, an electrostatic latent image developing developer containing the toner, an image forming method using the developer, and It is an object of the present invention to provide a method for producing a toner for developing an electrostatic latent image having excellent production stability.

As a result of intensive studies to solve the above-mentioned problems of the prior art, the present inventors have found that the above object can be achieved by the following contents.
That is, the present invention
<1> An electrostatic latent image developing toner containing at least a binder resin containing an amorphous polyester resin and a crystalline polyester resin, a colorant, and a release agent, wherein the volume average particle size distribution index The ratio of GSDv to the number average particle size distribution index GSDp (GSDv / GSDp) is 0.95 or more, the weight average molecular weight (Mw) of the binder resin is 15000 to 60000, and the weight average of the binder resin The ratio (Mw / Mn) of the molecular weight (Mw) to the number average molecular weight (Mn) is 3.5 to 7.0, the shape factor SF1 is 110 to 140, and the average shape distribution index (S ₈₄ / S ₁₆ The electrostatic latent image developing toner is characterized in that ^1/2 is 1.08 or less.

  <2> The amorphous polyester resin is a mixture of two types of amorphous polyester resins A and B having different weight average molecular weights, and the weight average molecular weights of the amorphous polyester resins A and B Mwa and Mwb, and when the ratio of the fumaric acid component of the total polyvalent carboxylic acid components constituting the amorphous polyester resins A and B is a mol% and b mol%, respectively, Mwa> Mwb And the toner for developing an electrostatic latent image according to <1>, wherein 50 mol%> a> b ≧ 0 mol% is satisfied.

  <3> The electrostatic latent image developing toner according to <1> or <2>, wherein the crystalline polyester resin contains fumaric acid as a polyvalent carboxylic acid component.

  <4> The method for producing a toner for developing an electrostatic latent image according to any one of <1> to <3>, wherein the amorphous polyester resin particle dispersion is obtained by dispersing amorphous polyester resin particles. A crystalline polyester resin particle dispersion in which crystalline polyester resin particles are dispersed, a colorant particle dispersion in which colorant particles are dispersed, and a release agent particle dispersion in which release agent particles are dispersed. An agglomeration step of forming an agglomerated particle comprising the amorphous polyester resin particle, the crystalline polyester resin particle, the colorant particle and the release agent particle; and a glass transition temperature of the amorphous polyester resin or higher. A coalescing and coalescing step of fusing and coalescing the aggregated particles by heating the aggregated particles, and a weight average molecule of a mixture of the amorphous polyester resin and the crystalline polyester resin (Mw) satisfies 15000 to 60000, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) satisfies 3.5 to 7.0. This is a method for producing a developing toner.

  <5> The method for producing a toner for developing an electrostatic latent image according to <4>, wherein the amorphous polyester resin is a mixture of two types of amorphous polyester resins having different weight average molecular weights. .

  <6> A developer for developing an electrostatic latent image comprising the toner for developing an electrostatic latent image according to any one of <1> to <3>.

  <7> A latent image forming step for forming an electrostatic latent image on the surface of the latent image holding member, and an electrostatic latent image formed on the surface of the latent image holding member using a developer held on the developer holding member. A developing step for developing and forming a toner image, a transferring step for transferring the toner image formed on the surface of the latent image holding member to the surface of the transfer target, and a heat fixing of the toner image transferred to the surface of the transfer target An image forming method, wherein the developer is the developer for electrostatic latent image development described in <6>.

  According to the present invention, an electrostatic latent image developing toner capable of forming a stable image in long-term use, an electrostatic latent image developing developer containing the toner, an image forming method using the developer, and production stability A method for producing a toner for developing an electrostatic latent image having excellent properties is provided.

  Hereinafter, the electrostatic latent image developing toner and the production method thereof, the electrostatic latent image developing developer, and the image forming method of the present invention will be described in detail.

<Electrostatic latent image developing toner and manufacturing method thereof>
The toner for developing an electrostatic latent image of the present invention (hereinafter sometimes simply referred to as “the toner of the present invention”) includes a binder resin containing an amorphous polyester resin and a crystalline polyester resin, a colorant, A toner for developing an electrostatic latent image containing at least a release agent, wherein a ratio (GSDv / GSDp) of a volume average particle size distribution index GSDv to a number average particle size distribution index GSDp is 0.95 or more. The weight average molecular weight (Mw) of the binder resin is 15000 to 60000, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the binder resin is 3.5 to 7.0, the shape factor SF1 is 110 to 140, and the average shape distribution index (S ₈₄ / S ₁₆ ) ^1/2 is 1.08 or less.

A conventional toner using an amorphous polyester resin as a binder resin has a non-crystalline polyester resin particle dispersion prepared by a known emulsification method, a colorant dispersion containing a colorant, and a release agent containing a release agent. It can be obtained by a toner preparation method (aggregation coalescence method) in which a mold agent dispersion is coagulated (coagulation step), heated, fused and coalesced (melt coalescence step).
This method is useful because it is possible to obtain a small-diameter toner and arbitrarily obtain a toner shape from an indefinite shape to a spherical shape. However, the aggregated particles aggregated in the aggregation process may be composed of the binder resin, the colorant, and the release agent uniformly. If the components contained in the aggregated particles are non-uniform, the melt coalescence process There is a difference in unity.

If this unity is different among the aggregated particles, the toner can be controlled to a desired shape on average, but irregular shapes, spheres or nearly spheres are mixed, and the shape factor varies. Becomes a large toner. This tendency is particularly remarkable when resins having different melt viscosities (resins having different molecular weights) are used in combination as a binder resin.
That is, agglomerated particles having a high melt viscosity and a high molecular weight resin ratio tend to be amorphous with a low melt coalescence rate, and agglomerated particles having a low melt viscosity and a medium to low molecular weight resin ratio tend to be spherical with a high melt coalescence rate.

  Further, in the case of producing a toner by this aggregation and coalescence method, the coalescence speed is very fast when a crystalline resin particle whose melt viscosity is remarkably lowered when the melting point is exceeded for the purpose of realizing low-temperature fixability. It becomes difficult to control the shape excluding. This tendency cannot be satisfactorily improved only by using an amorphous polyester resin and a crystalline polyester resin as a binder resin. The reason is that amorphous polyester and crystalline polyester should be uniformly aggregated, but in practice, crystalline polyester tends to homoaggregate, and the ratio of crystalline polyester is large, making shape control difficult. The toner particles are also generated.

  Such spherical toner particles are difficult to remove by the blade cleaning method, and the spherical toner (residual toner) that has passed through the blade adheres to and contaminates the conductive elastic roller. If the amount of residual toner existing between the electrostatic latent image holding member and the conductive elastic roller increases, uniform charging cannot be realized on the surface of the electrostatic latent image holding member, and the electrostatic latent image on the electrostatic latent image holding member does not appear. Disturbed and causes image defects. Even if the residual toner is slight, if the copier is used for a long period of time in the environment described below, an image defect may be caused.

  For example, suppose that a copy machine is used continuously in a high temperature and high humidity environment such as a rainy season, and then the copy machine is not used for several days on a holiday. At this time, a discharge product such as NOx tends to adhere to the electrostatic latent image holding member exposed to a high humidity environment. In this state, if residual toner adheres to the conductive elastic roller (even if it is a slight amount that did not cause image defects before), it will be combined with the electrostatic latent image carrier contamination by the discharge product. As a result, uniform charging cannot be realized on the surface of the electrostatic latent image holding member, causing an image defect (specifically, a streak defect occurs in the image). Since this discharge product can be removed by copying several sheets, image defects will not continue for a long time, but if the electrostatic latent image carrier is contaminated without using a copier for a while, , Streak-like image defects may occur in several sheets immediately after resuming copying (as in the morning after the holidays).

  In order to solve such a problem, it is necessary to control the toner shape to a desired shape factor, narrow the shape distribution and narrow the particle size distribution, and simultaneously suppress the generation of spherical particles. For that purpose, it is necessary that a part of the binder resin has a certain molecular weight. That is, the weight average molecular weight (Mw) derived from the binder resin of the toner is 15000 to 60000, and the molecular weight distribution represented by the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn). However, it is necessary that it is 3.5-7.0. By doing so, it is possible to prevent the toner shape distribution from increasing due to deformation of the shape due to stress such as stirring.

In addition, the molecular weight distribution can be controlled by using two or more kinds of amorphous polyester resins having different molecular weights. In that case, two kinds of resin particles contained in the resin particle dispersion are previously used. If the composite particles are made of amorphous polyester resins having different molecular weights, the composition uneven distribution among the agglomerated particles can be suppressed, the fusing rate between the agglomerated particles becomes uniform, and the toner shape factor varies. Reduced and effective.
In addition, by adjusting the amount of fumaric acid in the amorphous polyester resin to a predetermined range, the cohesiveness between the crystalline polyester resin and the amorphous polyester resin is improved, and spherical particles with a high ratio of crystalline polyester are generated. Can be suppressed.

  If the toner can be uniformly controlled to a desired shape, development, transfer and cleaning properties are improved. In particular, the cleaning property by the blade is greatly affected by the toner shape, and the more irregular the toner, the better. The spherical toner is difficult to clean.

  In the present invention, the weight average molecular weight (Mw) of the binder resin is in the range of 15000 to 60000, but 20000 to 40000 is preferable. If it is less than 15,000, the melt viscosity of the toner is low, the melt coalescence speed is fast, and it is difficult to control the toner shape to be indefinite. Further, since the toner strength is weak, for example, cracking or chipping occurs due to mechanical stress in the developing machine, the charge amount changes, and streaks are likely to occur due to uneven charging of the photoreceptor. If it is larger than 60000, the melt coalescence is poor and the time of the melt coalescence process is very long, and the fixability is also deteriorated.

  In the present invention, the molecular weight distribution represented by the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) must be 3.5 to 7.0. More preferably, it is larger than 4.5. If it is less than 3.5, the low molecular weight component and / or the high molecular weight component of the resin molecule constituting the binder resin will decrease. For this reason, as described above, the problem that occurs when the weight average molecular weight (Mw) is smaller than 15000 and / or the problem that occurs when the weight average molecular weight (Mw) is larger than 60000 occurs. On the other hand, if it is larger than 7.0, the molecular weight distribution is too wide, and it becomes difficult to produce uniform toner particles.

When two types of amorphous polyester resins having different weight average molecular weights are used in combination as the amorphous polyester resin, among the resins having different molecular weights, the molecular weight of the high molecular weight side resin is 18,000 to 100,000 in weight average molecular weight (Mw). It is preferably 20,000 to 60,000. If it is less than 18000, it is difficult to make the toner in an irregular shape, and if it is more than 100,000, the fixability is deteriorated.
The molecular weight of the low molecular weight side resin is preferably 7000 to 18000, more preferably 9000 to 15000, in weight average molecular weight (Mw). If it is less than 7000, the toner strength deteriorates and, for example, cracks and chipping may occur due to mechanical stress in the developing machine, resulting in defects such as cloud. When it is larger than 18000, the fixing property is deteriorated.

  The mass ratio of the high molecular weight resin and the low molecular weight resin is preferably in the range of 5:95 to 70:30, more preferably 15:85 to 50:50. If the content of the high molecular weight resin in the total amount of the amorphous polyester resin is 5% by mass or more, the shape control of the amorphous toner becomes easy. When it is 70% by mass or less, the fixing property is improved.

  In addition, the measurement of the said weight average molecular weight (Mw) and number average molecular weight (Mn) was performed on condition of the following using gel permeation chromatography (GPC). GPC uses “HLC-8120GPC, SC-8020 (manufactured by Tosoh Corporation)”, and the column uses two “TSKgel, SuperHM-H (6.0 mm ID × 15 cm, manufactured by Tosoh Corporation)” THF (tetrahydrofuran) was used as an eluent. The measurement conditions were a sample concentration of 0.5% and a flow rate of 0.6 ml / min. Sample injection volume 10 μl, measurement temperature 40 ° C., using an IR detector. The calibration curve is “polystylen standard sample TSK standard” manufactured by Tosoh Corporation: “A-500”, “F-1”, “F-10”, “F-80”, “F-380”, “A-2500”. ”,“ F-4 ”,“ F-40 ”,“ F-128 ”, and“ F-700 ”.

  A known emulsification method can be used to prepare composite particles composed of two types of amorphous polyester resins having different molecular weights, but the obtained particle size distribution is sharp and the volume average particle size is 0.08 to A phase inversion emulsification method that is easy to obtain in the range of 0.40 μm is effective.

The phase inversion emulsification method can be carried out by the following method. The resin is dissolved in an amphiphilic organic solvent for dissolving the resin alone or in a mixed solvent to obtain an oil phase. A small amount of a basic compound is dropped while stirring the oil phase, and water is dropped little by little while stirring, and water droplets are taken into the oil phase. Next, when the dripping amount of water exceeds a certain amount, the oil phase and the water phase are reversed and the oil phase becomes oil droplets. Thereafter, an aqueous dispersion is obtained through a solvent removal step under reduced pressure.
In order to obtain composite particles composed of two kinds of amorphous polyester resins having different molecular weights, different resins may be simultaneously added and dissolved when the resin is dissolved in an organic solvent or a mixed solvent.

  Here, the amphiphilic organic solvent means a solvent having a solubility in water at 20 ° C. of at least 5 g / L or more, preferably 10 g / L or more. When the solubility is less than 5 g / L, there is a problem that the effect of accelerating the aqueous treatment speed is poor, and the resulting aqueous dispersion is also inferior in storage stability.

  Examples of the above-mentioned amphiphilic organic solvents include ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, and tert-amyl. Alcohols such as alcohol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol and cyclohexanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, cyclohexanone and isophorone, tetrahydrofuran, dioxane Ethers such as ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, 3-methoxybutyl acetate, and propionate. , Esters such as ethyl propionate, diethyl carbonate, dimethyl carbonate, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol ethyl ether acetate, diethylene glycol, diethylene glycol Monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol ethyl ether acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene Glycol derivatives such as N-glycol methyl ether acetate and dipropylene glycol monobutyl ether, as well as 3-methoxy-3-methylbutanol, 3-methoxybutanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, ethyl acetoacetate, etc. It can be illustrated. These solvents can be used singly or in combination of two or more.

  The polyester resin according to the present invention is neutralized with a basic compound when dispersed in an aqueous medium. In the present invention, the neutralization reaction between the carboxyl group of the polyester resin and the basic compound is the starting force for aqueous formation, and aggregation between particles can be prevented by the electric repulsive force between the generated carboxyl anions.

  Examples of the basic compound include ammonia and organic amine compounds having a boiling point of 250 ° C. or lower. Examples of desirable organic amine compounds include triethylamine, N, N-diethylethanolamine, N, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine, isopropylamine, iminobispropylamine, ethylamine , Diethylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, dimethylaminopropylamine, methyliminobispropylamine, 3-methoxypropylamine, monoethanolamine, diethanolamine, Triethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine and the like can be mentioned.

  The basic compound is preferably added in an amount that can be at least partially neutralized according to the carboxyl group contained in the polyester resin, that is, 0.2 to 9.0 times equivalent to the carboxyl group. It is more preferable to add 6 to 2.0 times equivalent. If the amount is less than 0.2 times equivalent, the effect of adding a basic compound is not observed. If the amount exceeds 9.0 times equivalent, it seems that the hydrophilicity of the oil phase increases excessively, but the particle size distribution becomes broad and good. A stable dispersion cannot be obtained.

The melting point of the crystalline polyester resin of the present invention is preferably in the range of 50 to 150 ° C, more preferably 60 to 90 ° C. If the melting point is 50 ° C. or higher, toner blocking is unlikely to occur. If it is 150 ° C. or lower, low-temperature fixability can be obtained.
The weight average molecular weight is preferably in the range of 5000 to 50000. The crystalline polyester resin is preferably contained in an amount of 3 to 30% by weight, more preferably 5 to 20% by weight, based on the whole toner. If it is 3% by mass or more, low-temperature fixability can be obtained. When the amount is 50% by mass or less, the mechanical strength of the toner is sufficient, filming on the surface of the photoreceptor is less likely to occur, and a problem that the fixed image is easily destroyed is less likely to occur.

  The release agent is preferably contained in an amount of 3 to 30% by mass, more preferably 5 to 15% by mass, based on the whole toner. If it is 3% by mass or more, sufficient fixing stability can be obtained. When the content is 30% by mass or less, filming on the surface of the photoconductor hardly occurs, and a problem that the fixed image is easily destroyed is less likely to occur.

  In the present invention, “crystalline polyester resin” refers to a resin having a clear endothermic peak, not a stepwise endothermic change in differential scanning calorimetry (DSC), and having no such characteristics. This is referred to as “amorphous polyester resin”. Moreover, in the case of the polymer which copolymerized the other component with respect to the said crystalline polyester main chain, when another component is 50 mass% or less, this copolymer is also called crystalline polyester resin. The crystalline polyester resin may show a plurality of melting peaks. In the present invention, the maximum peak is regarded as the melting point of the crystalline polyester resin.

  In the toner of the present invention, it is necessary that the amorphous polyester resin used in combination has a certain degree of affinity with the crystalline polyester resin. If there is no affinity, toner particles are formed without incorporating crystalline polyester particles in the aggregation process and melting and coalescence process in the production of the toner, and the aggregated particles are not composed of the intended components. Thus, a spherical toner in which the crystalline polyester resin is unevenly distributed is formed.

  In order to give affinity, it is preferable to use fumaric acid for the polyvalent carboxylic acid component constituting the amorphous polyester resin. Since fumaric acid is linear and has a planar molecular structure, the affinity with crystalline resin can be improved to some extent, and the phase of amorphous resin / crystalline resin is so difficult that toner shape control becomes difficult. Since melting does not proceed, it is suitable as a constituent monomer for obtaining the toner of the present invention.

In the present invention, the amorphous polyester resin is a mixture of two types of amorphous polyester resins A and B having different weight average molecular weights, and the weight average molecular weights of the amorphous polyester resins A and B Mwa and Mwb, and when the ratio of the fumaric acid component of all the polyvalent carboxylic acid components constituting the amorphous polyester resins A and B is a mol% and b mol%, respectively, Mwa> Mwb and It is preferable to satisfy 50 mol%>a> b ≧ 0 mol%.
Further, the amount of fumaric acid in the amorphous polyester resin is more preferably 40 mol%>a> b ≧ 0 mol%, and further preferably 25 mol%>a> b = 0 mol%. When the fumaric acid content of the low molecular weight amorphous polyester resin is less than the fumaric acid content of the high molecular weight amorphous polyester resin, the crystalline polyester resin is less likely to agglomerate with the low molecular weight amorphous polyester resin, resulting in a spherical toner. It becomes difficult to do.

  In the toner of the present invention, it is preferable that the crystalline polyester resin contains fumaric acid as a polyvalent carboxylic acid component in order to increase cohesion.

  The volume average particle diameter of the toner in the present invention is preferably 2 to 9 μm, and more preferably 3 to 8 μm. If the volume average particle diameter is 2 μm or more, the chargeability is sufficient and the developability is improved. If it is 9 μm or less, the resolution of the image is improved.

The toner of the present invention has a ratio (GSDv / GSDp) of the volume average particle size distribution index GSDv to the number average particle size distribution index GSDp of 0.95 or more.
When the ratio of the volume average particle size distribution index GSDv to the number average particle size distribution index GSDp (GSDv / GSDp) is less than 0.95, toner chargeability deterioration due to time-dependent deformation of the toner shape due to stirring, toner scattering, fogging, etc. occur. And may cause image defects.

In the present invention, the volume average particle diameter of the toner and the values of the volume average particle size distribution index GSDv and the number average particle size distribution index GSDp are measured and calculated as follows.
First, with respect to the divided particle size range (channel) of the toner particle size distribution measured using a measuring device of Coulter Multisizer II (manufactured by Beckman-Coulter), the volume and number of individual toner particles from the small diameter side. A cumulative distribution is drawn, and the particle diameter of 16% is defined as the volume average particle diameter D16v and the number average particle diameter D16p, and the particle diameter of 50% is the volume average particle diameter D50v and the number average. The particle size is defined as D50p. Similarly, particle diameters that are 84% cumulative are defined as volume average particle diameter D84v and number average particle diameter D84p. At this time, the volume average particle size distribution index (GSDv) is defined as D84v / D16v, and the number average particle size distribution index (GSDp) is defined as D84p / D16p. (GSDv) and number average particle size index (GSDp) can be calculated.

Further, the toner of the present invention is required to have a shape factor SF1 of 110 to 140 and an average shape distribution index (S ₈₄ / S ₁₆ ) ^1/2 of 1.08 or less. The shape factor SF1 is preferably in the range of 125 to 140, and the average shape distribution index (S ₈₄ / S ₁₆ ) ^1/2 is preferably 1.06 or less.

The shape factor SF1 and the average shape distribution index (S ₈₄ / S ₁₆ ) ^1/2 were measured as follows using a Luzex image analyzer (manufactured by Nireco Corporation, FT).
First, an optical microscopic image of toner spread on a slide glass is taken into a Luzex image analyzer through a video camera, and the maximum length (ML) and projected area (A) are measured for 500 or more toners. The square of the maximum length × π × 100 / (4 × projection area), that is, ML ² × 100 / (4A) was calculated, and the average value was calculated as the shape factor SF1. The shape factor SF1 means that the closer this value is to 100, the closer the shape of the toner particle on the projection surface is to a true sphere.
Further, with respect to all the toner particles measured by the Luzex image analysis apparatus, the measurement range of the shape factor SF1 is set to 100 to 172, the division width is set to 3, and divided into 24 sections and counted, and the shape factor SF1 is small. The number of toner particles was sequentially accumulated from the section side. At this time, the value of _{S 16} of the shape factor SF1 in the case where the cumulative 16%, the value of shape factor SF1 in the case where the cumulative 84% as _{S 84,} the average shape distribution index using this value _{(S 84} / S ₁₆ ) ^1/2 was determined.

  When the shape factor SF1 is less than 110, generally, residual toner is generated in the transfer process during image formation. Therefore, it is necessary to remove the residual toner. However, the cleaning performance when the residual toner is cleaned with a blade or the like is required. It is easy to damage and may result in image defects. On the other hand, when the shape factor SF1 exceeds 140, when the toner is used as a developer, the toner may be destroyed due to collision with a carrier in the developing device. In this case, as a result, the fine powder increases or the release agent component exposed on the toner surface may contaminate the surface of the photoreceptor and impair the charging characteristics. May cause problems.

When the average shape distribution index (S ₈₄ / S ₁₆ ) ^1/2 is larger than 1.08, the shape distribution of the toner particles becomes wide, and the transfer efficiency from the photosensitive member or intermediate transfer member to the recording medium is improved. In some cases, the image becomes non-uniform and unevenness of the image is likely to occur. Furthermore, if spherical or near-spherical toners are mixed, they will not be completely transferred but will go to the cleaning process, but will not be completely cleaned and will remain on the photoconductor, disturbing the next charging and development, and image quality. Leading to deterioration.

  Next, a method for producing the toner of the present invention will be described. The method for producing the toner of the present invention is not particularly limited, but the amorphous polyester resin particle dispersion in which the amorphous polyester resin particles are dispersed and the crystalline polyester resin particle dispersion in which the crystalline polyester resin particles are dispersed. A liquid, a colorant particle dispersion in which colorant particles are dispersed, and a release agent particle dispersion in which release agent particles are dispersed are mixed, and the amorphous polyester resin particles and the crystalline polyester resin particles are mixed. An agglomeration step of forming an agglomerated particle including the colorant particle and the release agent particle, and fusing and coalescing the agglomerated particles by heating the agglomerated particles above the glass transition temperature of the amorphous polyester resin It is preferable to have at least a fusion and unification step. In this case, the weight average molecular weight (Mw) of the mixture of the amorphous polyester resin and the crystalline polyester resin satisfies 15000 to 60000, and the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) (Mw / Mn) satisfies 3.5 to 7.0.

  The amorphous polyester resin used for the production of the toner may be a mixture of two types of amorphous polyester resins having different weight average molecular weights. The amorphous polyester resin particle dispersion in this case can be prepared by mixing and emulsifying two types of amorphous polyester resins.

  The toner of the present invention may have a core / shell structure. In this case, after the aggregation step (core aggregated particles) is formed in the above-described aggregation step, a shell layer containing resin particles is formed on the surface of the core aggregated particles to obtain core / shell aggregated particles.

  In the coalescence and coalescence process of fusing and coalescing the core / shell agglomerated particles, the core / shell agglomerated particles are heated to a temperature higher than the glass transition temperature of the resin constituting the core agglomerated particles or the shell layer (binder resin). You can unite them.

  By producing the toner using the toner production method of the present invention, it is possible to easily obtain a toner with good dispersion of the release agent in the toner and little toner surface exposure.

  In the aggregation step, first, an amorphous polyester resin particle dispersion, a crystalline polyester resin particle dispersion, a colorant particle dispersion, and a release agent particle dispersion are prepared.

  Next, the amorphous polyester resin particle dispersion, the crystalline polyester resin particle dispersion, the colorant particle dispersion, and the release agent particle dispersion are mixed, and the amorphous polyester resin particles, the crystalline polyester resin particles, Aggregated particles comprising amorphous polyester resin particles, crystalline polyester resin particles, colorant particles, and release agent particles having a diameter substantially close to a desired toner diameter by hetero-aggregating colorant particles and release agent particles (Core aggregated particles) are formed.

  A shell layer is formed on the surface of the core aggregated particles by attaching resin particles to the surface of the core aggregated particles using a resin particle dispersion containing resin particles to form a coating layer (shell layer) having a desired thickness. Aggregated particles having a core / shell structure (core / shell aggregated particles) are obtained. The resin particles used for forming the shell layer may be the same as or different from the polyester resin particles used for forming the core aggregate particles.

  The particle diameters of the amorphous polyester resin particles, the crystalline polyester resin particles, the colorant particles, and the release agent particles used in the agglomeration process are for easily adjusting the toner diameter and the particle size distribution to desired values. In addition, it is preferably 1 μm or less, and more preferably in the range of 100 to 300 nm.

  When forming the core agglomerated particles, the balance of the amounts of the two polar ionic surfactants (dispersants) contained in the amorphous polyester resin particles, the crystalline polyester resin particles, and the colorant particle dispersion is shifted in advance. I can leave. For example, an inorganic metal salt such as calcium nitrate or a polymer of an inorganic metal salt such as polyaluminum chloride is ionically neutralized and heated below the glass transition temperature of the amorphous polyester resin particles. Aggregated particles can be produced.

  When forming a shell layer, a resin particle dispersion treated with a dispersant having a polarity and an amount that compensates for a deviation in the balance between the two polar dispersants as described above is placed in a solution containing core aggregated particles. The core / shell aggregated particles can be prepared by adding and further slightly heating below the glass transition temperature of the resin particles used in forming the core aggregated particles or the shell layer as necessary. The formation of the core agglomerated particles and the shell layer may be performed repeatedly in multiple steps.

Next, in the coalescence and coalescence step, the core / shell aggregated particles obtained through the second aggregation step are used in the solution in the glass transition temperature (highest in the resin particles contained in the core / shell aggregated particles). A toner is obtained by heating above the glass transition temperature of a resin having a glass point transition temperature) and fusing and coalescence.
After completion of the coalescence and coalescence process, the toner formed in the solution is dried through a known washing process, solid-liquid separation process, and drying process to obtain a toner.

  In addition, it is preferable that the washing | cleaning process performs substitution washing | cleaning by ion-exchange water fully from a charging point. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, and the like are preferably used from the viewpoint of productivity. Further, although the drying process is not particularly limited, freeze drying, flash jet drying, fluidized drying, vibration fluidized drying and the like are preferably used from the viewpoint of productivity.

The polyester resin used in the toner of the present invention is not particularly limited, and a known polyester resin material can be used.
For example, a crystalline polyester resin and all other polyester resins are synthesized from a polyvalent carboxylic acid component and a polyhydric alcohol component. In the present invention, a commercially available product may be used as the polyester resin, or an appropriately synthesized product may be used.

  Examples of the polyvalent carboxylic acid component include oxalic acid, succinic acid, glutaric acid, adipic acid, peric acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12 -Aliphatic dicarboxylic acids such as dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, mesaconic acid Aromatic dicarboxylic acids such as dibasic acids such as, and the like, and anhydrides and lower alkyl esters thereof are also included, but not limited thereto.

  Examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and the like, and anhydrides thereof. And lower alkyl esters. These may be used individually by 1 type and may use 2 or more types together.

  Moreover, as an acid component, it is preferable that the dicarboxylic acid component which has a sulfonic acid group other than the above-mentioned aliphatic dicarboxylic acid and aromatic dicarboxylic acid is contained. The dicarboxylic acid having a sulfonic acid group is effective in that it can favorably disperse a coloring material such as a pigment. Further, when the resin is prepared by emulsifying or suspending the entire resin in water, emulsification or suspension can be performed without using a surfactant if a sulfonic acid group is present.

  Examples of the dicarboxylic acid having a sulfone group include, but are not limited to, 2-sulfoterephthalic acid sodium salt, 5-sulfoisophthalic acid sodium salt, and sulfosuccinic acid sodium salt. Moreover, these lower alkyl esters, acid anhydrides, etc. are also mentioned. These divalent or higher carboxylic acid components having a sulfonic acid group are contained in an amount of 0 to 20 mol%, preferably 0.5 to 10 mol%, based on all carboxylic acid components constituting the polyester. If the content is too low, the stability of the emulsified particles with time deteriorates. On the other hand, if the content exceeds 10 mol%, not only the crystallinity of the polyester resin is lowered, but also the process of fusing the particles after aggregation is adversely affected. There is a problem that it becomes difficult to adjust.

  Furthermore, it is more preferable to contain a dicarboxylic acid component having a double bond in addition to the aforementioned aliphatic dicarboxylic acid and aromatic dicarboxylic acid. A dicarboxylic acid having a double bond can be suitably used to prevent hot offset at the time of fixing in that it can be radically cross-linked through the double bond. Examples of such dicarboxylic acids include, but are not limited to, maleic acid, fumaric acid, 3-hexenedioic acid, and 3-octenedioic acid. In addition, these lower esters, acid anhydrides and the like are also included. Among these, fumaric acid, maleic acid and the like are mentioned in terms of cost.

  As the polyhydric alcohol component, an aliphatic diol is preferable, and a linear aliphatic diol having 7 to 20 carbon atoms in the main chain portion is more preferable. When the aliphatic diol is branched, the crystallinity of the polyester resin is lowered and the melting point is lowered, so that toner blocking resistance, image storage stability, and low-temperature fixability may be deteriorated. Further, when the number of carbon atoms is less than 7, when the polycondensation with aromatic dicarboxylic acid is performed, the melting point becomes high and fixing at low temperature may be difficult. On the other hand, when the number exceeds 20, it is difficult to obtain practical materials. easy. The carbon number is more preferably 14 or less.

  Specific examples of the aliphatic diol suitably used for the synthesis of the crystalline polyester resin include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1, 6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13 -Tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,14-eicosandecanediol and the like are exemplified, but not limited thereto. Among these, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable in view of availability.

Examples of the trivalent or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like. These may be used individually by 1 type and may use 2 or more types together.
Among the polyhydric alcohol components, the content of the aliphatic diol component is preferably 80 mol% or more, and more preferably 90% or more. When the content of the aliphatic diol component is 80 mol% or more, the crystallinity of the polyester resin is increased and the melting point is increased, so that toner blocking resistance, image storage stability, and low-temperature fixability are improved.

  If necessary, monovalent acids such as acetic acid and benzoic acid and monovalent alcohols such as cyclohexanol benzyl alcohol can also be used for the purpose of adjusting the acid value and hydroxyl value.

The method for producing the crystalline polyester resin is not particularly limited, and can be produced by a general polyester polymerization method in which an acid component and an alcohol component are reacted. Examples thereof include direct polycondensation and transesterification. They are manufactured using different types of monomers.
The production of the crystalline polyester resin can be carried out at a polymerization temperature of 180 to 230 ° C., and the reaction is carried out while reducing the pressure in the reaction system as necessary to remove water and alcohol generated during condensation. When the monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a solubilizer and dissolved. In the polycondensation reaction, the dissolution auxiliary solvent is distilled off. In the case where a monomer having poor compatibility exists in the copolymerization reaction, it is preferable that the monomer having poor compatibility and the monomer and the acid or alcohol to be polycondensed are condensed in advance and then polycondensed together with the main component.

The crystalline polyester resin particle dispersion can be prepared by adjusting the acid value of the resin or by emulsifying and dispersing it using an ionic surfactant or the like.
Catalysts that can be used in the production of the crystalline polyester resin include alkali metal compounds such as sodium and lithium; alkaline earth metal compounds such as magnesium and calcium; metals such as zinc, manganese, antimony, titanium, tin, zirconium, and germanium Compounds: Phosphorous acid compounds, phosphoric acid compounds, amine compounds, and the like, and specific examples include the following compounds.

  For example, sodium acetate, sodium carbonate, lithium acetate, lithium carbonate, calcium acetate, calcium stearate, magnesium acetate, zinc acetate, zinc stearate, zinc naphthenate, zinc chloride, manganese acetate, manganese naphthenate, titanium tetraethoxide, titanium Tetrapropoxide, titanium tetraisopropoxide, titanium tetrabutoxide, antimony trioxide, triphenylantimony, tributylantimony, tin formate, tin oxalate, tetraphenyltin, dibutyltin dichloride, dibutyltin oxide, diphenyltin oxide, zirconium tetrabutoxide, naphthene Zirconate, zirconyl carbonate, zirconyl acetate, zirconyl stearate, zirconyl octylate, germanium oxide, triphenyl Phosphite, tris (2, 4-t-butylphenyl) phosphite, ethyltriphenylphosphonium bromide, triethylamine, compounds such as triphenyl amine.

  The acid value of the polyester resin (mg number of KOH required to neutralize 1 g of resin) is easy to obtain the molecular weight distribution as described above, easy to prepare a resin dispersion by the phase inversion emulsification method, It is preferable that the toner is 4 to 30 mg KOH / g because it is easy to maintain the environmental stability (stability of chargeability when the temperature and humidity are changed) of the toner obtained. The acid value of the polyester resin can be adjusted by controlling the amount of carboxyl groups at the end of the polyester by the blending ratio and reaction rate of the raw material polycarboxylic acid and polyhydric alcohol. Or what has a carboxyl group in the principal chain of polyester is obtained by using trimellitic anhydride as a polyvalent carboxylic acid component.

If the polyester resin is oily and dissolves in a solvent with relatively low solubility in water, the resin is dissolved in these solvents and dissolved in water using a disperser such as a homogenizer together with an ionic surfactant or polymer electrolyte. The resin particle dispersion can be prepared by dispersing the particles in the solution and then evaporating the solvent by heating or reducing the pressure.
In addition, a resin particle dispersion can be easily prepared by emulsifying and dispersing an amorphous polyester resin in water.
The particle diameters of the resin particles, the colorant particles, and the release agent particles can be measured, for example, with a laser diffraction particle size distribution analyzer (LA-700, manufactured by Horiba, Ltd.).

  Examples of the release agent that can be used in the present invention are not particularly limited. Minerals such as montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, petroleum wax, natural gas Waxes and their modified products, low molecular weight polyolefins such as polyethylene, polypropylene and polybutene, silicones which show a softening point upon heating, fatty acids such as oleic acid amide, erucic acid amide, ricinoleic acid amide, stearic acid amide Examples include amides, plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil, and animal waxes such as beeswax. With 10 to 18 carbon atoms That higher alcohols or their mixtures, and can be exemplified higher fatty acid monoglyceride or mixture thereof having 16 to 22 carbon atoms, it can be used in combination of these things.

The release agent particle dispersion is prepared by dispersing the release agent in water together with a polymer electrolyte such as an ionic surfactant, a polymer acid or a polymer base, and heating it to the melting point or higher and applying a strong shear. Adjust by making particles.
As a device for fine dispersion by the above mechanical means, Menton Gorin high-pressure homogenizer (Gorin), continuous ultrasonic homogenizer (Nippon Seiki Co., Ltd.), Nanomizer (Nanomizer), Microfluidizer (Mizuho Industrial Co., Ltd.) Company), Harrell type homogenizer, Slasher (Mitsui Mining Co., Ltd.), Cavitron (Eurotech Co., Ltd.) and the like.

A known colorant can be used as the colorant used in the present invention.
Carbon black, magnetic powder, etc. can be used as the black pigment. Examples of yellow pigments include Hansa Yellow, Hansa Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR, Slen Yellow, Quinoline Yellow, and Permanent Yellow NCG. Red pigments include Bengala, Watch Young Red, Permanent Red 4R, Resol Red, Brilliantamine 3B, Brilliantamine 6B, Dupont Oil Red, Pyrazolone Red, Rhodamine B Lake, Lake Red C, Rose Bengal, Eoxin Red, Alizarin Lake Etc. Blue pigments include bitumen, cobalt blue, alkali blue rake, Victoria blue rake, fast sky blue, indanthrene blue BC, aniline blue, ultramarine blue, calco oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite green oxare. Rate. Moreover, these can be mixed and used in the state of a solid solution.

These colorants are dispersed by a known method, and for example, a rotary shear type homogenizer, a media type dispersing machine such as a ball mill, a sand mill, or an attritor, a high-pressure opposed collision type dispersing machine, or the like is preferably used.
These colorants can be dispersed in an aqueous solvent using a polar ionic surfactant and a homogenizer as described above to prepare a colorant particle dispersion.
The colorant is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP permeability, and dispersibility in the toner. The amount of the colorant added to the toner of the present invention is preferably in the range of 4 to 20 parts by mass with respect to 100 parts by mass of the binder resin contained in the toner.

  In the production of the toner of the present invention, examples of the surfactant used for emulsion polymerization, pigment dispersion, resin particle dispersion, release agent dispersion, aggregation, or stabilization thereof include sulfate ester, sulfonate, phosphorus Anionic surfactants such as acid esters and soaps, cationic surfactants such as amine salts and quaternary ammonium salts, and non-ions such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols It is also effective to use a surfactant in combination, and general means such as a rotary shear homogenizer, a ball mill having a media, a sand mill, and a dyno mill can be used for dispersion.

Furthermore, a charge control agent can be added to the toner of the present invention in order to further improve and stabilize the chargeability. As the charge control agent, various commonly used charge control agents such as quaternary ammonium salt compounds, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium, and triphenylmethane pigments can be used. In the aggregation process and the coalescence process, a material that is difficult to dissolve in water is preferable in terms of controlling the ionic strength that affects the stability of the aggregated particles and reducing wastewater contamination.
When inorganic particles are added to the toner as a charge control agent, examples of such inorganic particles include silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate and other external toner surface additives. All inorganic particles used as can be mentioned. In this case, these inorganic particles can be used by being dispersed in a solvent using an ionic surfactant, a polymer acid, a polymer base, or the like.

Also, for the purpose of imparting fluidity and improving cleaning properties, after drying in the same way as normal toner, inorganic particles such as silica, alumina, titania and calcium carbonate, and resin particles such as vinyl resin, polyester and silicone are flow aids. As a cleaning aid, it can be added to the toner surface of the present invention by shearing in a dry state.
Examples of inorganic oxide particles added to the toner include SiO ₂ , TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, CaO, K ₂ O, and Na _{2. O,} it can be exemplified _{ZrO 2, CaO · SiO 2,} K 2 O · (TiO 2) n, Al 2 O 3 · 2SiO 2, CaCO 3, MgCO 3, BaSO 4, MgSO 4 , and the like. Of these, silica particles and titania particles are particularly preferable. It is desirable that the surface of the inorganic oxide particles is previously hydrophobized. This hydrophobization treatment is more effective for improving the powder fluidity of the toner, as well as the environmental dependency of charging and the resistance to carrier contamination.

  The hydrophobizing treatment can be performed by immersing the inorganic oxide particles in a hydrophobizing agent. Although there is no restriction | limiting in particular as said hydrophobic treatment agent, For example, a silane coupling agent, a silicone oil, a titanate coupling agent, an aluminum coupling agent etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, silane coupling agents are preferable.

  As the silane coupling agent, for example, any type of chlorosilane, alkoxysilane, silazane, and a special silylating agent can be used. Specifically, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, Methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltriethoxysilane, decyltrimethoxysilane, hexamethyldisilazane, N, O- (bistrimethylsilyl) acetamide, N, N- ( Trimethylsilyl) urea, tert-butyldimethylchlorosilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane , Γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercapto Examples thereof include propyltrimethoxysilane and γ-chloropropyltrimethoxysilane. The amount of the hydrophobizing agent varies depending on the kind of the inorganic oxide particles and cannot be defined unconditionally, but is usually about 1 to 50 parts by mass with respect to 100 parts by mass of the inorganic oxide particles.

<Developer for developing electrostatic latent image>
The developer for developing an electrostatic latent image of the present invention contains the toner for developing an electrostatic latent image of the present invention. When the electrostatic latent image developing toner of the present invention is used alone, it is prepared as a one-component electrostatic latent image developing developer, and when used in combination with a carrier, a two-component electrostatic latent image developing developer is used. Prepared as an agent. The electrostatic latent image developing developer of the present invention is preferably a two-component electrostatic latent image developing developer.

  Although the carrier used in the present invention is not particularly defined, examples of the core material of the carrier include magnetic metals such as iron, steel, nickel and cobalt, alloys of these with manganese, chromium and rare earths, and ferrite and magnetite. Magnetic oxides and the like can be mentioned. From the viewpoint of core surface properties and core material resistance, preferred are ferrites, particularly alloys with manganese, lithium, strontium, magnesium and the like.

  The carrier used in the present invention is preferably formed by coating the surface of the core with a resin, and the resin is not particularly limited as long as it can be used as a matrix resin, and can be appropriately selected according to the purpose. . For example, polyolefin resins such as polyethylene and polypropylene; polyvinyl resins and polyvinylidene resins such as polystyrene, acrylic resins, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether and polyvinyl ketone Vinyl chloride-vinyl acetate copolymer; styrene-acrylic acid copolymer; straight silicone resin composed of organosiloxane bond or modified product thereof; polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene, etc. Fluorine resin; Silicone resin; Polyester; Polyurethane; Polycarbonate; Phenol resin; Urea-formaldehyde resin, Melamine tree , Benzoguanamine resins, urea resins, amino resins such as polyamide resins, epoxy resins, per se known resins and the like. These may be used individually by 1 type and may use 2 or more types together. In the present invention, among these resins, it is preferable to use at least a fluororesin and / or a silicone resin. The use of at least a fluorine-based resin and / or a silicone resin as the resin is advantageous in that it has a high effect of preventing carrier contamination (impact) due to toner and external additives.

  The film made of the resin is formed by dispersing at least resin particles and / or conductive particles in the resin. Examples of the resin particles include thermoplastic resin particles and thermosetting resin particles. Among these, thermosetting resins are preferable from the viewpoint of relatively easily increasing the hardness, and resin particles made of nitrogen-containing resin containing N atoms are preferable from the viewpoint of imparting negative chargeability to the toner. In addition, these resin particles may be used individually by 1 type, and may use 2 or more types together. The average particle diameter of the resin particles is preferably about 0.1 to 2 μm, more preferably 0.2 to 1 μm. If the average particle diameter of the resin particles is 0.1 μm or more, the resin particles are excellent in dispersibility in the coating, whereas if it is 2 μm or less, the resin particles are unlikely to fall out of the coating.

  Examples of the conductive particles include metal particles such as gold, silver and copper, carbon black particles, semiconductive oxide particles such as titanium oxide and zinc oxide, titanium oxide, zinc oxide, barium sulfate, aluminum borate, and titanic acid. Examples thereof include particles in which the surface of potassium powder or the like is covered with tin oxide, carbon black, metal, or the like. These may be used individually by 1 type and may use 2 or more types together. Among these, carbon black particles are preferable from the viewpoints of production stability, cost, conductivity, and the like. The type of carbon black is not particularly limited, but carbon black having a DBP oil absorption of about 50 to 250 ml / 100 g is preferable because of excellent production stability.

The method for forming the coating is not particularly limited. For example, the resin particles such as crosslinkable resin particles and / or the conductive particles, and a styrene acrylic resin, a fluorine resin, a silicone resin as a matrix resin, etc. And a method of using a film-forming solution containing the above resin in a solvent.
Specifically, the carrier core material is immersed in the film forming liquid, a spray method in which the film forming liquid is sprayed on the surface of the carrier core material, and the carrier core material is floated by flowing air And kneader coater method in which the film forming solution is mixed and the solvent is removed. Among these, the kneader coater method is preferable in the present invention.

The solvent used in the film-forming liquid is not particularly limited as long as it can dissolve only the resin as a matrix resin, and can be selected from among solvents known per se, for example, Aromatic hydrocarbons such as toluene and xylene, ketones such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran and dioxane, and the like. When the resin particles are dispersed in the coating, since the resin particles and the resin as a matrix resin are uniformly dispersed in the thickness direction and the tangential direction of the carrier surface, the carrier is used for a long time. Even when the coating is worn, it is possible to always maintain the same surface formation as when it is not used, and to maintain a good charge imparting ability for the toner over a long period of time.
In the case where the conductive particles are dispersed in the coating, the conductive particles and the resin as the matrix resin are uniformly dispersed in the thickness direction and the tangential direction of the carrier surface. Even when the coating is worn out for a long period of time, the same surface formation as when not in use can be maintained, and carrier deterioration can be prevented for a long period of time. In addition, when the said resin particle and the said electroconductive particle are disperse | distributed to the said film, there can exist the above-mentioned effect simultaneously.

<Image forming method>
The image forming method of the present invention is formed on the surface of the latent image holding body using a latent image forming step of forming an electrostatic latent image on the surface of the latent image holding body and a developer held on the developer holding body. A developing process for developing the electrostatic latent image to form a toner image, a transfer process for transferring the toner image formed on the surface of the latent image holding body to the surface of the transfer target, and the image transferred to the surface of the transfer target A fixing step of thermally fixing the toner image, and using the developer for developing an electrostatic latent image of the present invention as the developer.

  The developer may be either a one-component system or a two-component system. As each of the above steps, a known step in the image forming method can be used. The image forming method of the present invention may include steps other than the steps described above.

As the latent image holding member, for example, a photosensitive member and a dielectric recording member can be used.
In the case of a photoreceptor, the surface of the photoreceptor is uniformly charged by a corotron charger, a contact charger or the like and then exposed to form an electrostatic latent image (latent image forming step). Next, the toner is attached to the electrostatic latent image in contact with or in proximity to a developing roll having a developer layer formed on the surface, and a toner image is formed on the photoreceptor (developing step). The formed toner image is transferred onto the surface of a transfer medium such as paper using a corotron charger or the like (transfer process). Further, the toner image transferred to the surface of the transfer target is heat-fixed by a fixing device, and a final toner image is formed.

Examples of the transfer target (recording medium) to which the toner image is transferred include plain paper, OHP sheet, and the like used in electrophotographic copying machines and printers.
In order to further improve the smoothness of the image surface after fixing, it is preferable that the surface of the transfer object is as smooth as possible. For example, coated paper in which the surface of plain paper is coated with a resin or the like, art paper for printing Etc. can be used suitably.

  For fixing in the present invention, a known fixing device can be used. For example, a fixing belt having a low surface energy material typified by a fluororesin component and a silicone resin on the surface and having a belt shape, similarly. Examples thereof include those having a low surface energy material typified by a fluororesin component and a silicone resin on the surface and having a cylindrical roll shape.

  Hereinafter, the present invention will be described in detail with reference to examples. However, the following examples do not limit the present invention.

<Production of toner>
-Synthesis of Amorphous Polyester Resin (1)-
In a heat-dried three-necked flask, 89 parts by mass of dimethyl terephthalate (46 mol%), 49 parts by mass of dimethyl fumarate (34 mol%), 40 parts by mass of dodecenyl succinic anhydride (15 mol%), 9.6 parts by weight of trimellitic anhydride Parts (5 mol%), bisphenol A ethylene oxide 2 mol adduct 32 parts by mass (10 mol%), bisphenol A propylene oxide 1 mol adduct 258 parts by mass (90 mol%) and 0.02 parts by mass of dibutyltin oxide as a catalyst The air in the container was brought into an inert atmosphere with nitrogen gas by depressurization, and the mixture was stirred and refluxed at 180 ° C. for 5 hours with mechanical stirring. Thereafter, the temperature was gradually raised to 230 ° C. under reduced pressure, and the mixture was stirred for 4 hours. When it became viscous, it was air-cooled, the reaction was stopped, and an amorphous polyester resin (1) was synthesized.

  The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the obtained amorphous polyester resin (1) were 49500 and 6700, respectively, by molecular weight measurement (polystyrene conversion) by gel permeation chromatography. Further, the glass transition temperature (Tg) of the amorphous polyester resin (1) is determined from room temperature to 150 using a differential scanning calorimeter (manufactured by Mac Science: DSC3110, thermal analysis system 001) in accordance with ASTM D3418-8. It was 60.4 degreeC when it measured on conditions with a temperature increase rate of 10 degree-C / min. Further, the acid value (AV) was measured by the following method and found to be 12.2 mgKOH / g.

The acid value is measured as follows. The basic operation conforms to JIS K-0070-1992.
1.5 g of the sample was precisely weighed, put in a 300 ml beaker, and 100 ml of a toluene / ethanol (4/1) mixture was added and dissolved. Potentiometric titration was performed with an ethanol solution of 0.1 mol / l KOH using an automatic titrator GT-100 (manufactured by Dia Instruments). The amount of KOH solution used at this time is A (ml), and a blank is measured at the same time. The amount of KOH solution used at this time is B (ml). From these values, the acid value was calculated by the following formula (1). In the formula (1), w is a precisely weighed sample amount, and f is a factor of KOH.

Acid value (mgKOH / g) = {(A−B) × f × 5.61} / w Formula (1)

-Synthesis of amorphous polyester resins (2) to (7)-
Amorphous polyester resins (2) to (7) were synthesized in the same manner as in the case of the amorphous polyester resin (1) except that the acidic component, alcohol component and catalyst described in Table 1 were used. Mw, Mn, Tg and AV were measured. The obtained results are shown in Table 1.

-Preparation of composite resin particle dispersion (1)-
Using an amorphous polyester resin, a composite resin particle dispersion (1) was prepared as follows.
-Amorphous polyester resin (1) 50 parts by mass-Amorphous polyester resin (2) 50 parts by mass-Ionic surfactant (Neogen RK, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1.8 parts by mass-Ion-exchanged water 210 parts by weight

  The above is heated to 100 ° C., sufficiently dispersed with a homogenizer (IKA, Ultra Turrax T50), then dispersed with a pressure discharge type gorin homogenizer for 1 hour, and a composite resin particle having a volume average particle diameter of 130 nm is dispersed. A liquid (1) was obtained.

-Preparation of composite resin particle dispersion (2) to single resin particle dispersion (10)-
A composite resin particle dispersion (2) to a single resin particle dispersion (10) were prepared in the same manner as in the case of the composite resin particle dispersion (1) except that the amorphous polyester resin shown in Table 2 was used.

-Preparation of crystalline polyester resin dispersion (A)-
In a heat-dried three-necked flask, 120 parts by mass of dimethyl dodecanedioate, 77 parts by mass of 1,9-nonanediol, and 0.013 parts by mass of dibutyltin oxide as a catalyst were added. Under an inert atmosphere with gas, the mixture was stirred and refluxed at 180 ° C. for 5 hours with mechanical stirring. Thereafter, the temperature was gradually raised to 230 ° C. under reduced pressure, and the mixture was stirred for 4 hours. When it became viscous, it was cooled with air, the reaction was stopped, and a crystalline polyester resin (A) was synthesized. Mw, Mn, melting point (Tm) and AV of the obtained resin were measured. The results are shown in Table 3.

Subsequently, using the crystalline polyester resin (A), a resin particle dispersion was prepared as follows.
・ Crystalline polyester resin (A) 90 mass parts ・ Ionic surfactant (Neogen RK, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1.8 mass parts ・ Ion-exchanged water 210 mass parts

  The above is heated to 100 ° C. and sufficiently dispersed with a homogenizer (IKA, Ultra Tarrax T50), then dispersed with a pressure discharge type gorin homogenizer for 1 hour, and a crystalline polyester resin having a volume average particle diameter of 130 nm. A dispersion (A) was obtained.

-Preparation of crystalline polyester resin dispersion (B)-
A crystalline polyester resin dispersion (B) was prepared in the same manner as in the preparation of the crystalline polyester resin dispersion (A) except that the acidic component, alcohol component and catalyst described in Table 3 were used. Mw, Mn, melting point (Tm) and AV of the obtained resin were measured. The results are shown in Table 3.

(Preparation of colorant particle dispersion)
・ Carbon black (Cabot Corporation, Regal 330) 30 parts by mass ・ Anionic surfactant (Nippon Oil & Fats, Newlex R) 2 parts by mass ・ Ion-exchanged water 220 parts by mass

  The above components are mixed and pre-dispersed for 10 minutes with a homogenizer (Ultra Turrax, manufactured by IKA), and then subjected to dispersion treatment at a pressure of 245 mPa for 15 minutes using a counter impact type wet pulverizer (Altimizer, manufactured by Sugino Machine). A colorant particle dispersion having a volume average particle size of 328 nm was obtained.

(Preparation of release agent particle dispersion)
・ 45 parts by weight of paraffin wax (HNP9, manufactured by Nippon Seiki Co., Ltd., melting point: 75 ° C.) 5 parts by weight of cationic surfactant (Neogen RK, manufactured by Daiichi Kogyo Seiyaku) 200 parts by weight of ion-exchanged water

  The components were mixed and heated to 80 ° C., pre-dispersed for 10 minutes with a homogenizer (Ultra Tarrax, manufactured by IKA), and then subjected to a dispersion treatment using a pressure-jet pulverizer (Gorin homogenizer, manufactured by Gorin). A release agent particle dispersion having a volume average particle diameter of 185 nm was obtained.

(Production of toner)
-Toner particles (1)-
Composite resin particle dispersion (1) 166 parts by weight Crystalline polyester resin dispersion (A) 24 parts by weight Colorant particle dispersion 52 parts by weight Release agent particle dispersion 51 parts by weight

  The above components were put into a round stainless steel flask to obtain a solution that was sufficiently mixed and dispersed with Ultra Turrax T50. Next, 0.19 parts by mass of polyaluminum chloride was added to this solution to produce core agglomerated particles, and the dispersion operation was continued using an ultra turrax. Further, the solution in the flask was heated to 45 ° C. with stirring in an oil bath for heating, and maintained at 45 ° C. for 60 minutes, and then 90 parts by mass of the composite resin particle dispersion (1) was slowly added to the core. / Shell aggregated particles were prepared.

  Thereafter, 0.5 mol / L aqueous sodium hydroxide solution was added to adjust the pH of the solution to 7.5, and then the stainless steel flask was sealed and heated to 85 ° C. while continuing stirring using a magnetic seal, Held for hours.

  After cooling, the particles dispersed in the solution were filtered, washed thoroughly with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed in 3 L of ion exchanged water at 40 ° C., and stirred and washed at 300 rpm for 15 minutes. This operation was further repeated 5 times, and when the pH of the filtrate was 7.01 and the electric conductivity was 15.8 μS / cm, No. was obtained by Nutsche suction filtration. Solid-liquid separation was performed using 5A filter paper, and the obtained solid was vacuum-dried over 12 hours to obtain black toner particles (1).

When the particle size distribution of the toner particles (1) was measured, the volume average particle size D50 was 5.9 μm, the volume average particle size distribution index GSDv was 1.20, the shape factor SF1 was 136, and the average shape distribution index. _(S 84 _{/ S} ^{16) 1/2} is 1.05, GSDv / GSDp was 0.97. Further, the binder resin (amorphous polyester resin (1), amorphous polyester resin (2), amorphous polyester resin (4), and crystalline polyester resin (A) used in the toner particles (1) is used. Mw and Mw / Mn of the mixture) were 34250 and 5.5, respectively.

-Toner particles (2) to (13)-
Toner particles (2) to (13) were obtained in the same manner as in the case of toner particles (1) except that the materials listed in Table 4 were used. The obtained toner particles were evaluated in the same manner as in the case of toner particles (1). Table 4 shows the obtained results.

Toner (1) added with 3.5 parts by weight of hydrophobic silica (TS720, manufactured by Cabot) as an external additive to 50 parts by weight of each toner particle, blended with a sample mill, Thru (13) were obtained. The values of D50, GSDv, SF1, (S ₈₄ / S ₁₆ ) ^1/2 , Mw, Mw / Mn, and GSDv / GSDp of each toner were the same as the values of the corresponding toner particles.

<Preparation of developer>
11 parts by mass of toluene, 2 parts by mass of diethylaminoethyl methacrylate-styrene-methyl methacrylate copolymer (copolymerization ratio: 2/20/78, weight average molecular weight 50,000), carbon black (Ca330, R330R) 0.2 Mass parts and glass beads (particle size 1 mm, equivalent to toluene) were put into a sand mill manufactured by Kansai Paint Co., Ltd. and stirred for 30 minutes at a rotational speed of 1200 rpm to prepare a coating resin layer forming solution.

Next, 100 parts by mass of this coating resin layer forming solution and Mn—Mg ferrite particles (true specific gravity: 4.6 g / cm ³ , volume average particle diameter: 35 μm, saturation magnetization: 65 emu / g) are vacuum degassed. After putting into a kneader and stirring for 10 minutes while maintaining the temperature at 60 ° C., the pressure was reduced and toluene was distilled off to obtain a ferrite carrier having a coating resin layer formed thereon.
To the ferrite carrier, the toner is mixed so that the toner concentration becomes 5%, stirred and mixed for 5 minutes by a ball mill, and developers (1) to (13) each containing toner (1) to (13). Was prepared.

[Example 1]
Using the obtained developer 1, using a printer DocuCenter Color 400CP modified machine manufactured by Fuji Xerox Co., Ltd. as an image forming apparatus, in a high temperature and high humidity (28 ° C., 85% RH) environment, a process speed of 150 mm / sec, 5000 sheets of images were formed under the condition of a fixing roll temperature of 150 ° C. Thereafter, the printer with the developer placed therein is left in this high-temperature and high-humidity environment for 72 hours, and then the evaluation image is further processed under the conditions of the process speed and the fixing roll temperature before being left in the high-temperature and high-humidity environment. Below, 5000 sheets of images were formed (the first cycle, the formation of 5000 sheets after leaving for 72 hours is taken as one cycle). Thereafter, the evaluation that 5000 sheets of images were formed after the printer with the developer put therein was left in this high temperature and high humidity environment for 72 hours was repeated 5 cycles.
In the image formation, C2 paper (manufactured by Fuji Xerox Co., Ltd.) was used as paper.
Further, as an evaluation image, an image obtained by outputting a solid image of 25 mm × 25 mm on an A4 size paper was used.

-Fixed image evaluation-
With respect to the fifth, 100th, and 5000th sheets in the 5000th image forming process in the first, third, and fifth cycles, the fixed image quality of the solid images was visually evaluated according to the following evaluation criteria. The results obtained are shown in Table 5.

A: No uneven transfer, streak, no problem.
○: The image was enlarged with a magnifying glass or the like, and slight transfer unevenness or streaks were observed, but there was no practical problem.
Δ: Some transfer unevenness or streaks were visually observed, but there was no practical problem.
X: Large transfer unevenness or streaks are observed, which cannot be used practically.

[Examples 2 to 6 and Comparative Examples 1 to 7]
Evaluation was conducted in the same manner as in Example 1 except that the developer described in Table 5 was used. The results obtained are shown in Table 5.

Table 5 shows the following.
Developers 1 to 6 that satisfy all the requirements of the present invention have no streaking / transfer unevenness from the initial stage to the end of the fifth cycle, and provide stable and good image quality even in discontinuous use in a high temperature and high humidity environment. Yes. However, developers 7 to 13 that do not satisfy any of the requirements of the present invention are at a level where the initial image quality is not a problem, but if left for a while after continuous use under high temperature and high humidity, the initial image quality immediately after resuming copying There is a defect.

Claims (7)

An electrostatic latent image developing toner containing at least a binder resin containing an amorphous polyester resin and a crystalline polyester resin, a colorant, and a release agent,
The ratio (GSDv / GSDp) of the volume average particle size distribution index GSDv to the number average particle size distribution index GSDp is 0.95 or more, the weight average molecular weight (Mw) of the binder resin is 15000 to 60000, The ratio (Mw / Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) of the resin is 3.5 to 7.0, the shape factor SF1 is 110 to 140, and the average shape distribution index ( A toner for developing an electrostatic latent image, wherein S ₈₄ / S ₁₆ ) ^1/2 is 1.08 or less.   The amorphous polyester resin is a mixture of two types of amorphous polyester resin A and amorphous polyester resin B having different weight average molecular weights, and the weight average molecular weights of the amorphous polyester resins A and B are each Mwa. And Mwb, where Mwa> Mwb and 50 mol when the ratio of the fumaric acid component in the total polyvalent carboxylic acid components constituting the amorphous polyester resins A and B is a mol% and b mol%, respectively. The toner for developing an electrostatic latent image according to claim 1, wherein%> a> b ≧ 0 mol% is satisfied.   The electrostatic latent image developing toner according to claim 1, wherein the crystalline polyester resin contains fumaric acid as a polyvalent carboxylic acid component. A method for producing a toner for developing an electrostatic latent image according to any one of claims 1 to 3,
An amorphous polyester resin particle dispersion in which amorphous polyester resin particles are dispersed; a crystalline polyester resin particle dispersion in which crystalline polyester resin particles are dispersed; a colorant particle dispersion in which colorant particles are dispersed; A release agent particle dispersion liquid in which mold agent particles are dispersed, and agglomerated particles containing the amorphous polyester resin particles, the crystalline polyester resin particles, the colorant particles, and the release agent particles. An aggregation process to form;
A coalescing and coalescing step of fusing and coalescing the aggregated particles by heating the aggregated particles above the glass transition temperature of the amorphous polyester resin;
Having at least
The mixture of the amorphous polyester resin and the crystalline polyester resin has a weight average molecular weight (Mw) satisfying 15000 to 60000, and a ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) (Mw / Mn). ) Satisfying 3.5 to 7.0, a method for producing a toner for developing an electrostatic latent image.   5. The method for producing a toner for developing an electrostatic latent image according to claim 4, wherein the amorphous polyester resin is a mixture of two types of amorphous polyester resins having different weight average molecular weights.   A developer for developing an electrostatic latent image, comprising the toner for developing an electrostatic latent image according to any one of claims 1 to 3. A latent image forming step for forming an electrostatic latent image on the surface of the latent image holding member, and developing the electrostatic latent image formed on the surface of the latent image holding member using a developer held on the developer holding member. A developing step for forming a toner image, a transfer step for transferring the toner image formed on the surface of the latent image holding member to the surface of the transfer target, and a fixing step for thermally fixing the toner image transferred on the surface of the transfer target. An image forming method comprising:
An image forming method, wherein the developer is the developer for developing an electrostatic latent image according to claim 6.