JP2007003840A - Toner for electrostatic charge image development, method for manufacturing the same, electrostatic charge image developer, and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner for electrostatic charge image development and a method for manufacturing the toner capable of achieving both of heat storage property and low temperature fixing property, having sufficient filming resistance and causing no image defect, and to provide an electrostatic charge image developer and an image forming method. <P>SOLUTION: The toner for electrostatic charge image development comprises a core particle containing a binder resin and a colorant and a shell layer covering the core particle, wherein the binder resin contains at least one of a crystalline polyester resin and an amorphous resin, and the shell layer contains amorphous resin fine particles. By controlling the volume average particle size, the glass transition temperature and the content of the amorphous resin fine particles to the respective specified ranges, the toner for electrostatic charge image development can achieve both of heat storage property and low temperature fixing property, has sufficient filming resistance, preventing an image defect and having preferable image gloss. The method for manufacturing the toner, and an electrostatic charge image developer and an image forming method are also provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrostatic charge image developing toner used for developing an electrostatic charge image in an electrophotographic apparatus utilizing an electrophotographic process such as a copying machine, a printer, a facsimile, and the like, a manufacturing method thereof, an electrostatic charge image developer, and The present invention relates to an image forming method.

  Many methods are known as electrophotographic methods (see, for example, Patent Document 1). In general, a latent image is electrically formed by various means on the surface of a photoreceptor (latent image holding body) using a photoconductive substance, and the latent image formed using toner is developed to form a toner image. After forming the toner image, the toner image is transferred to the surface of a transfer medium such as paper, optionally via an intermediate transfer body, and fixed by heating, pressurization, heat pressurization, solvent vapor, or the like. Through this, an image is formed. Further, the toner remaining on the surface of the photoreceptor is cleaned by various methods as necessary, and is used again for developing the toner image.

  As a fixing technique for fixing the toner image transferred to the surface of the transfer target, a hot roll fixing is performed in which the transfer target having the toner image transferred is inserted between a pair of rolls including a heating roll and a pressure roll and fixed. The law is common. As a similar technique, a fixing method in which one or both of the rolls is replaced with a belt is also known. Compared with other fixing methods, these techniques can obtain a fast and robust image, have high energy efficiency, and cause less harm to the environment due to volatilization of solvents and the like.

  On the other hand, the toner image transferred to the surface of the transfer target through the transfer step is melted by being heated by the fixing member heated in the fixing step, and is fixed to the surface of the transfer target. It is known that in a fixing process, a toner image is not fixed unless a toner image as well as a transfer target is sufficiently heated by a fixing member. If the transfer medium is not sufficiently heated, only the toner is melted by the heating from the fixing member, and a so-called cold offset is generated in which the toner adheres to the fixing member.

  In addition, when the transfer target or the toner image is excessively heated, the viscosity of the toner decreases, and so-called hot offset occurs in which part or all of the toner image adheres to the fixing member side. Therefore, it is necessary to set the fixing conditions so that both the cold offset and the hot offset do not occur when the fixing member is used to heat the transfer target or the toner image transferred to the surface thereof.

  On the other hand, in order to save power in a fixing process that occupies a certain amount of electric power as the demand for energy saving necessary for image formation increases, and in order to expand the fixing conditions, the toner fixing temperature It is necessary to lower the temperature. By lowering the toner fixing temperature, in addition to saving power and expanding fixing conditions, the waiting time until the fixing temperature on the surface of the fixing member such as a fixing roll at the time of power input is shortened, so-called warm-up time is shortened. The life of the fixing member can be extended.

  As a means for lowering the toner fixing temperature, a technique for lowering the glass transition temperature (Tg) of the toner resin (binder resin) is generally performed. However, it is known that if the glass transition temperature is too low, blocking (a phenomenon in which toner particles aggregate and become agglomerates) is likely to occur, and the preservability of toner on a fixed image is adversely affected. . For this reason, the lower limit of the glass transition temperature of the toner is practically 60 ° C. Although this glass transition temperature is a design point of many toner resins currently on the market, it has not been possible to obtain a toner that can be fixed at low temperature by the method of lowering the glass transition temperature. Although the fixing temperature can be lowered by using a plasticizer, there is a problem that a so-called blocking phenomenon occurs in which toners are fixed to each other during storage or in a developing machine.

  As a means for achieving both toner blocking prevention and low-temperature fixability, a method using a crystalline resin as a binder resin is known (see, for example, Patent Document 2 and Patent Document 3). In this case, although it is important that the melting point of the crystalline resin is practically designed to be 50 ° C. or higher, since the toner starts to melt near the melting point, it is resistant to the temperature rise in the electrophotographic apparatus. It is not possible to obtain sufficient heat storage properties. Further, setting the melting point to be high for the purpose of imparting heat storage properties causes an increase in fixing temperature, and it is difficult to achieve both low temperature fixing properties and heat storage properties.

  On the other hand, as means for solving the above-mentioned problems, the core particles (hereinafter abbreviated as “core particles”) made of a crystalline resin or an amorphous resin having a low glass transition temperature (or melting temperature) (60 ° C. or less). A so-called core-shell type toner has been proposed in which a coating layer (shell layer) is provided on the surface of the core particles.

  Conventionally proposed as the core-shell type toner is, for example, a toner in which small particles are embedded and coated on the surface of base particles having an outflow start temperature of 110 ° C. or lower (for example, see Patent Document 4). In addition, a toner having a higher molecular weight around a styrene acrylic core material having a glass transition temperature (Tg) of 50 to 70 ° C. and encapsulated with a styrene shell material having a high glass transition temperature (for example, see Patent Document 5). In addition, a toner in which resin particles for surface modification are fixed to core particles by mechanical impact force (for example, see Patent Document 6), a core material composed of saturated fatty acids or saturated alcohols having a melting point of 40 to 100 ° C. is used in water. After suspension, the toner encapsulated with resin fine particles (see, for example, Patent Document 7) has a thermally stable layer and Tg of 65 ° C. or lower on the surface of the low-viscosity resin particles. The toner of the laminated thermoplastic resin coating layer (for example, see Patent Document 8) have been proposed respectively.

  However, none of these toners are excellent in offset resistance, storage stability, and transferability while achieving low-temperature fixability that has been required in recent years. A capsule-type toner having a core-shell structure with a continuous shell has insufficient low-temperature fixability, and a toner having a particulate shell as described in Patent Document 4 has low viscoelasticity when the toner is melted. Since it does not contain a release agent, the anti-offset property was insufficient.

  Further, as means for solving the above-described problems, a toner in which resin fine particles having a glass transition temperature of 60 to 110 ° C. are adhered to the surface of core particles containing a resin having a glass transition temperature of 25 to 55 ° C. (for example, Patent Document 9) or a toner in which resin fine particles having a glass transition temperature of 40 to 80 ° C. are attached to the surface of core particles containing a resin having a glass transition temperature of 20 to 40 ° C. (for example, refer to Patent Document 10). Proposed. However, in such a method, although low-temperature fixability can be realized, since the complete coating layer is not formed, the core particle component easily oozes out to the shell surface layer, and the heat storage property becomes insufficient particularly at high temperatures. There is a problem.

  Also, the resin particles having a crosslinked structure are fused to the surface of the core particles containing a polyester-based resin and a low molecular weight resin having a weight average molecular weight of 2000 to 10000 so that they do not reach the continuous layer, and the core component is eluted in the fixing step. A method of promoting has been proposed (see, for example, Patent Document 11). However, in the above method, due to the use of an organic solvent at the time of toner preparation, the elution component from the core particles oozes out into the coating layer of the crosslinked resin fine particles, and in particular, the heat storage property of the toner is improved. It becomes insufficient. In addition, so-called filming occurs in which melted toner adheres to the surface of the photoreceptor in a film shape, and image quality defects are likely to occur.

Japanese Patent Publication No.42-23910 Japanese Patent Publication No. 56-13943 Japanese Examined Patent Publication No.62-39428 Japanese Patent No. 2750853 Japanese Patent Laid-Open No. 5-181301 JP-A-6-342224 JP-A-8-254853 JP-A-9-258480 JP 2001-175025 A JP-A-9-179336 JP 2004-198658 A

  Thus, if a continuous shell layer of an amorphous resin having a high glass transition temperature is provided on the toner, the heat storage property can be imparted, but the fixing temperature rises. In addition, when a discontinuous shell layer is provided by attaching resin fine particles with a high glass transition temperature on the surface of core particles containing a resin with a low glass transition temperature, low temperature fixability can be imparted, but heat storage The current situation is that the heat storage property and the low-temperature fixing property cannot be compatible with each other. Furthermore, even if both heat storage and low-temperature fixability can be achieved, if the strength of the toner itself is insufficient or the resin strength of the coating layer is weak, a white point defect may be caused in the development process by filming. Since there are problems such as image density reduction and image density reduction, it is eagerly desired to provide a toner with excellent total balance in which other characteristics are compatible at a high level.

  The present invention relates to a toner for developing an electrostatic charge image that can achieve both heat storage and low-temperature fixability, has sufficient filming resistance, and does not cause image defects, a method for producing the same, and an electrostatic charge image developer. And an image forming method.

  The present invention is an electrostatic charge image developing toner having a binder resin, a core particle containing a colorant, and a shell layer covering the core particle, wherein the binder resin includes a crystalline polyester resin and a non-polyester resin. Including at least one of crystalline resins, and the shell layer includes amorphous resin fine particles, the amorphous resin fine particles have a volume average particle diameter of 20 to 800 nm, and a glass transition temperature of 65 ° C. or higher, The content of the amorphous resin fine particles is in the range of 5 to 25% by weight with respect to the weight of the core particles.

  In the electrostatic image developing toner, the amorphous resin fine particles are preferably amorphous crosslinked fine particles.

  The present invention also provides a toner for developing an electrostatic image having core particles containing a binder resin and a colorant and a shell layer covering the core particles, wherein the binder resin is a crystalline polyester resin. And at least one of an amorphous resin, and the shell layer includes amorphous crosslinked fine particles.

  The present invention also relates to a method for producing a toner for developing an electrostatic image having core particles containing a binder resin and a colorant, and a shell layer covering the core particles, the crystalline polyester resin and the amorphous A step of forming core particles containing a binder resin containing at least one of the crystalline resins and a colorant, and agglomeration in which amorphous resin fine particles are adhered to the core particles to form amorphous resin adhered particles And a melting step of forming the shell layer by heating the amorphous resin adhering particles, wherein the amorphous resin fine particles have a volume average particle size of 20 to 800 nm and a glass transition temperature of 65 ° C. or higher. And the content of the amorphous resin fine particles is in the range of 5 to 25% by weight with respect to the weight of the core particles.

  The present invention also provides an electrostatic image developer containing the electrostatic image developing toner.

  Furthermore, the present invention uses a latent image forming step for forming an electrostatic latent image on the surface of the latent image holding member and a developer carried on the developer carrying member, and the electrostatic image formed on the surface of the latent image holding member. A developing step of developing a latent image to form a toner image, a transferring step of transferring the toner image formed on the surface of the latent image holding member to the surface of the transfer target, and a toner image transferred to the surface of the transfer target A fixing step of fixing the toner, wherein the developer is the electrostatic charge image developer.

  In the present invention, in the electrostatic charge image developing toner having a binder resin, a core particle containing a colorant, and a shell layer covering the core particle, the binder resin is a crystalline polyester resin or an amorphous resin. By including at least one, the shell layer contains amorphous resin fine particles, and the volume average particle diameter, glass transition temperature and content of the amorphous resin fine particles are specified in a specific range, thereby making it possible to maintain heat storage and low temperature. Toner for developing electrostatic image having both good fixability, sufficient filming resistance, no image defect, and good image gloss, method for producing the same, and electrostatic image developer In addition, an image forming method can be provided.

  Further, in the present invention, in the electrostatic image developing toner having a core particle containing a binder resin and a colorant and a shell layer covering the core particle, the binder resin is a crystalline polyester resin or an amorphous resin. Including at least one of the above, and the shell layer containing amorphous cross-linked fine particles, it is possible to achieve both heat storage and low-temperature fixability, and it has sufficient filming resistance and image defects occur. In addition, it is possible to provide a toner for developing an electrostatic image having good image glossiness, a method for producing the same, an electrostatic image developer, and an image forming method.

  Hereinafter, embodiments of the present invention will be described in the order of an electrostatic image developing toner, a method for producing an electrostatic image developing toner, an electrostatic image developer, and an image forming method.

<Toner for electrostatic image development>
The electrostatic image developing toner according to the exemplary embodiment (hereinafter sometimes abbreviated as “toner”) is a toner having a low-temperature fixability, but contains a binder resin and a colorant, and mainly includes a low-temperature fixability. Is a so-called function-separated core-shell type toner having a core particle portion that imparts a core particle and a shell portion that covers the core particle and mainly imparts heat storage properties and filming resistance.

(Core particles)
The core particles of the toner for developing an electrostatic charge image according to the exemplary embodiment include a binder resin including at least one of a crystalline polyester resin and an amorphous resin and a colorant, and other components as necessary. Containing.

  The binder resin used for the core particles in the present embodiment includes at least one of a crystalline polyester resin and an amorphous resin, but the crystalline polyester resin may be used alone, or the amorphous resin may be used. It may be used alone, or a blend system of a crystalline polyester resin and an amorphous resin may be used. When the amorphous resin is used alone, the glass transition temperature (Tg) of the amorphous resin is preferably 45 ° C. or lower. Crystalline polyester resin has sharp melt properties, excellent low-temperature fixability, and amorphous resin has excellent mechanical strength. To achieve both heat storage and low-temperature fixability, crystalline polyester resin and It is preferable to use a mixed system with an amorphous resin.

  Here, the “main component” refers to a main component among the components constituting the binder resin, and specifically refers to a component constituting 50% by mass or more of the binder resin. Furthermore, it is preferably 70% by mass or more of the binder resin, more preferably 90% by mass or more, and may be 100% by mass.

  When the crystalline polyester resin is used alone as the main component of the binder resin, the melting point or glass transition temperature of the toner may be in the range of 45 to 110 ° C. from the viewpoint of low-temperature fixability for the reasons described later. Preferably, it is in the range of 60-90 degreeC (refer the item of crystalline polyester resin). Since the viscosity of the toner rapidly decreases with the melting point or the glass transition temperature as a boundary, blocking occurs when the toner is stored in a temperature environment higher than the melting point. Therefore, it is preferable that the melting point of the toner is not less than a lower limit temperature in a general high-temperature environment that is exposed when the toner is stored or after an image is formed, that is, not less than 45 ° C. On the other hand, when the melting point or glass transition temperature exceeds 110 ° C., low-temperature fixing may not be possible.

  Further, when an amorphous resin is used alone as the binder resin component of the core particles, the glass transition temperature is preferably less than 45 ° C. from the viewpoint of low-temperature fixability. When the glass transition temperature is 45 ° C. or higher, the heat storage property is improved, but the low-temperature fixability may be hindered.

  Further, when a mixed system of a crystalline polyester resin and an amorphous resin is used as the binder resin, the melting point or glass transition temperature of the core particles (toner) is preferably within a range of 45 to 110 ° C. More preferably, it is in the range of 60 to 90 ° C. The mixing ratio of the crystalline polyester resin and the amorphous resin is determined based on the relationship between the melting point of the crystalline polyester resin and the glass transition temperature of the amorphous resin. Therefore, it is important to select a resin component that does not inhibit low-temperature fixability as an amorphous resin. The mixing ratio of the crystalline polyester resin and the amorphous resin is in the range of 3:97 to 50:50 by weight ratio, and preferably in the range of 5:95 to 40:60. If the amount of the crystalline polyester resin is less than 3:97, the low-temperature fixability is inhibited, and if the amount of the crystalline polyester resin is more than 40:60, the heat storage property may be deteriorated.

  The melting point or glass transition temperature of the binder resin can be determined as the melting peak temperature of input compensated differential scanning calorimetry based on JIS K-7121: 87. In this measurement, a plurality of melting peaks may be shown. In this case, the maximum peak is regarded as the melting point.

  Specific examples of resins other than the crystalline polyester resin and the amorphous resin that may be included in the binder resin used in the present embodiment include an amorphous polyester resin, an amorphous styrene-acrylic resin, and a non-crystalline resin. Any crystalline epoxy resin or the like conventionally used as a toner resin can be used.

(Crystalline polyester resin)
The crystalline polyester resin used as the binder resin component of the core particle is a crystalline resin having polyester as a main skeleton, and is excellent in low-temperature fixability and affinity for paper. When a crystalline resin having other monomer as the main skeleton (for example, polyethylene) is used as the main component, it is not suitable for use because it adversely affects the charging characteristics and is inferior in affinity with paper.

  In this embodiment, “crystalline” of “crystalline polyester resin” means a clear endothermic peak, not a step-like endothermic change in differential scanning calorimetry (DSC) of resin, core particles, or toner. It means having. Specifically, in differential scanning calorimetry (DSC) using a differential scanning calorimeter (equipment name: DSC-60 type) manufactured by Shimadzu Corporation equipped with an automatic tangential processing system, a rate of temperature increase of 10 ° C./min. A “clear” endothermic peak is assumed when the temperature from the onset point to the top of the endothermic peak when the temperature is raised at 10 ° C. is within 10 ° C. Further, from the viewpoint of sharp melt, the temperature from the onset point to the peak top of the endothermic peak is preferably within 10 ° C, and more preferably within 6 ° C. Specify any point on the flat part of the baseline in the DSC curve and any point on the flat part of the falling part from the baseline, and the intersection of the tangents of the flat part between the two points is automatically set as the “onset point”. Obtained automatically by the tangent processing system. Further, the endothermic peak may show a peak having a width of 40 to 50 ° C. when the toner is used.

  Further, the “crystalline polyester resin” as described above is a polymer (copolymer) obtained by polymerizing a component constituting polyester and other components in addition to a polymer having a 100% polyester structure. ) Also means. However, in the latter case, the component other than the polyester constituting the polymer (copolymer) is 50% by weight or less.

  The acid value of the crystalline polyester resin (mg number of KOH necessary to neutralize 1 g of resin) is easy to obtain a desired molecular weight distribution, and it is easy to ensure the granulation property of the toner particles by the emulsion dispersion method. The environmental stability of the obtained toner (charging stability when the temperature and humidity change) is easily maintained, and therefore, it is preferably 1 to 30 mg KOH / g. The acid value of the crystalline polyester resin can be adjusted by controlling the carboxyl group at the terminal of the polyester according to the blending ratio and reaction rate of the starting polyhydric carboxylic 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.

  The crystalline polyester resin is synthesized from a polyvalent carboxylic acid component and a polyhydric alcohol component. In addition, in this embodiment, a commercial item may be used as said polyester resin, and what was synthesize | combined suitably may be used.

  As the polyvalent carboxylic acid component, aromatic dicarboxylic acids and aliphatic dicarboxylic acids are preferable, and among them, aliphatic dicarboxylic acids are desirable, and linear carboxylic acids are particularly desirable. Examples of the polyvalent carboxylic acid component include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, peric acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, and 1,10-decane. Dicarboxylic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid Examples include aliphatic dicarboxylic acids such as acids, aromatic dicarboxylic acids such as dibasic acids such as phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, and 4,4′-biphenyldicarboxylic acid. In addition, these anhydrides and lower alkyl esters thereof are also included, but not limited thereto.Among the aliphatic dicarboxylic acids, in view of availability, sebacic acid and 1,10-decanedicarboxylic acid are preferable. Of the aromatic dicarboxylic acids, terephthalic acid is preferred from the standpoints of availability and easy formation of a low melting point polymer.

  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.

  In addition to the above-mentioned aliphatic dicarboxylic acid component and aromatic dicarboxylic acid component, the acid component includes components such as a dicarboxylic acid-derived component having a double bond and a dicarboxylic acid-derived component having a sulfonic acid group. It is preferable that

  The component derived from a dicarboxylic acid having a double bond is derived from a lower alkyl ester or acid anhydride of a dicarboxylic acid having a double bond in addition to a component derived from a dicarboxylic acid having a double bond. Components are also included. The dicarboxylic acid-derived component having a sulfonic acid group is derived from a lower alkyl ester or acid anhydride of a dicarboxylic acid having a sulfonic acid group, in addition to a component derived from a dicarboxylic acid having a sulfonic acid group. Components are also included.

  The dicarboxylic acid having a double bond can be suitably used for preventing hot offset at the time of fixing in that it can be radically crosslinked through a double bond. Examples of such dicarboxylic acids include, but are not limited to, fumaric acid, maleic acid, mesaconic acid, 3-hexenedioic acid, and 3-octenedioic acid. Moreover, these lower alkyl esters, acid anhydrides, etc. are also mentioned. Among these, fumaric acid, maleic acid and the like are preferable in terms of cost.

  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 entire resin is emulsified or suspended in water to produce fine particles, if a sulfonic acid group is present, it can be emulsified or suspended without using a surfactant as described later. Examples of such a 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.

  Further, lower alkyl esters such as dimethyl sodium salt of 5-sulfoisophthalic acid, acid anhydrides, and the like are also included. Among these, 5-sulfoisophthalic acid sodium salt, 5-sulfoisophthalic acid dimethyl sodium salt and the like are preferable in terms of cost.

  All of these acid-derived components other than aliphatic dicarboxylic acid-derived components and aromatic dicarboxylic acid-derived components (dicarboxylic acid-derived components having double bonds and dicarboxylic acid-derived components having sulfonic acid groups) As content in an acid-derived structural component, 1-15 structural mol% is preferable and 2-10 structural mol% is more preferable.

  When the content is less than 1 component mol%, the stability of the emulsified particles may deteriorate. On the other hand, when the content exceeds 15 component mol%, not only the crystallinity of the polyester resin is lowered but also the particles are fused after aggregation. This may adversely affect the process to be performed and may cause a problem that it is difficult to adjust the core particle size.

  In the present specification, “constituent mol%” refers to a percentage when each constituent component (acid-derived constituent component or alcohol-derived constituent component) in the polyester resin is defined as one unit (mol).

  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 the toner blocking resistance, the image storage stability, and the low-temperature fixability may be deteriorated. Further, when the number of carbon atoms is less than 7, when the polycondensation with an aromatic dicarboxylic acid is performed, the melting point becomes high and fixing at low temperature may be difficult. Tends to be difficult. The chain carbon number is more preferably 14 or less.

  Further, when a polyester is obtained by condensation polymerization with an aromatic dicarboxylic acid, the chain carbon number is preferably an odd number. When the chain carbon number is an odd number, the melting point of the polyester resin is lower than when the chain carbon number is an even number, and the melting point tends to be a value within the numerical range described later.

  Specific examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 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, 1,20-eicosanediol, and the like, but are not limited thereto. Among these, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable in view of availability, and 1,9-nonanediol is preferable in terms of a low melting point.

  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.

  The polyhydric alcohol component has an aliphatic diol-derived constituent component content of 80 constituent mol% or more, and includes other components as necessary. As the alcohol-derived constituent component, the content of the aliphatic diol-derived constituent component is preferably 90 constituent mol% or more.

  When the content of the aliphatic diol-derived constituent component is less than 80 mol%, 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 deteriorate. May end up.

  Other components included as necessary include diol-derived components having double bonds and diol-derived components having sulfonic acid groups. If necessary, monovalent acids such as acetic acid and benzoic acid and monovalent alcohols such as cyclohexanol and benzyl alcohol can also be used for the purpose of adjusting the acid value and hydroxyl value.

  Examples of the diol having a double bond include 2-butene-1,4-diol, 3-butene-1,6-diol, 4-butene-1,8-diol, and the like.

  Examples of the diol having a sulfonic acid group include 1,4-dihydroxy-2-sulfonic acid benzene sodium salt, 1,3-dihydroxymethyl-5-sulfonic acid benzene sodium salt, and 2-sulfo-1,4-butanediol sodium. Examples include salts.

  When adding these alcohol-derived components other than aliphatic diol-derived components (diol-derived component having a double bond and diol-derived component having a sulfonic acid group), the content in these alcohol-derived components Is preferably 1 to 20 mol%, more preferably 2 to 10 mol%.

  When the content of the alcohol-derived constituent component other than the aliphatic diol-derived constituent component is less than 1 constituent mol%, the pigment dispersion is not good, the emulsified particle size becomes large, and it is difficult to adjust the toner diameter by aggregation. On the other hand, if it exceeds 20 component mol%, the crystallinity of the polyester resin is lowered, the melting point is lowered, the storage stability of the image is deteriorated, or the emulsified particle size is too small to dissolve in water. , Latex may not occur.

  As melting | fusing point of crystalline polyester resin, it is preferable that it is the range of 60-120 degreeC, and it is more preferable that it is the range of 70-100 degreeC.

  When the melting point is less than 60 ° C., powder aggregation tends to occur and the storability of a fixed image may be deteriorated. On the other hand, when the melting point exceeds 120 ° C., low-temperature fixing may not be possible. In the present embodiment, the melting point of the polyester resin is measured by using the differential scanning calorimeter (DSC), and the endothermic peak when measured at a heating rate of 10 ° C. per minute from room temperature to 150 ° C. The top value of was used.

  The production method of the 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. For example, direct polycondensation, transesterification method, etc. Produced separately for different types. The molar ratio (acid component / alcohol component) when the acid component reacts with the alcohol component varies depending on the reaction conditions and the like, and cannot be generally stated, but is usually about 1/1.

  The production of the polyester resin can be carried out at a polymerization temperature of 180 to 230 ° C., and the reaction system is reacted under reduced pressure as necessary to remove water and alcohol generated during condensation.

  If the monomer is not dissolved or compatible at the reaction temperature, a high boiling point solvent is added as a solubilizer and dissolved. In the polycondensation reaction, the dissolution auxiliary solvent is distilled off. If there is a monomer with poor compatibility in the copolymerization reaction, it is advisable to condense the monomer with poor compatibility with the monomer and the acid or alcohol to be polycondensed in advance before polycondensing with the main component. .

  Catalysts that can be used in the production of the polyester resin include alkali metal compounds such as sodium and lithium, alkaline earth metal compounds such as magnesium and calcium, and metal compounds such as zinc, manganese, antimony, titanium, tin, zirconium, and germanium. , Phosphorous acid compounds, phosphoric acid compounds, and amine compounds. 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-di -t- butyl-phenyl) phosphite, ethyltriphenylphosphonium bromide, triethylamine, compounds such as triphenyl amine.

[Amorphous resin]
The “amorphous resin” used as the binder resin component of the core particle means that the temperature from the onset point to the peak top of the endothermic peak is 10 ° C. in the differential scanning calorimetry (DSC) of the resin, core particle or toner. When it exceeds, it indicates that the resin has no clear endothermic peak. Specifically, in differential scanning calorimetry (DSC) using a differential scanning calorimeter (equipment name: DSC-60 type) manufactured by Shimadzu Corporation equipped with an automatic tangential processing system, a rate of temperature increase of 10 ° C./min. When the temperature from the onset point to the top of the endothermic peak when the temperature is raised at 10 ° C. exceeds 10 ° C., or when no clear endothermic peak is observed, it is assumed to be “amorphous”. Further, the temperature from the onset point to the peak top of the endothermic peak preferably exceeds 12 ° C., and more preferably no clear endothermic peak is observed. The method for obtaining the “onset point” in the DSC curve is the same as in the case of the “crystalline polyester resin”.

  In the toner of the present exemplary embodiment, examples of the amorphous resin used for the core particle and the shell layer include conventionally known thermoplastic binder resins. Specifically, styrene, parachlorostyrene, α- Homopolymer or copolymer of styrenes such as methylstyrene (styrene resin); methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, Homopolymers or copolymers of vinyl groups such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc .; acrylonitrile, methacrylonitrile Homopolymers or copolymers of vinyl nitriles such as vinyl resins Homopolymers or copolymers of vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether (vinyl resins); homopolymers or copolymers of vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone; (Vinyl resin); Homopolymer or copolymer of olefins such as ethylene, propylene, butadiene, isoprene (olefin resin); epoxy resin, polyester resin, polyurethane resin, polyamide resin, cellulose resin, polyether resin, etc. And non-vinyl condensation resins, and graft polymers of these non-vinyl condensation resins and vinyl monomers. These resins may be used alone or in combination of two or more. Among these resins, vinyl resins and polyester resins are particularly preferable.

  In the case of a vinyl resin, it is advantageous in that a resin particle dispersion can be easily prepared by emulsion polymerization or seed polymerization using an ionic surfactant or the like. Examples of the vinyl monomers include vinyl polymer acids and vinyl polymer bases such as acrylic acid, methacrylic acid, maleic acid, cinnamic acid, fumaric acid, vinyl sulfonic acid, ethyleneimine, vinylpyridine, and vinylamine. Examples include monomers as raw materials.

  On the other hand, when a polyester resin is used as the amorphous molecule in the toner of the present embodiment, the resin particle dispersion can be easily prepared by adjusting the acid value of the resin or by emulsifying and dispersing using an ionic surfactant. It is advantageous in that it can be prepared. The amorphous polyester resin used for emulsification dispersion is synthesized by dehydration condensation of polyvalent carboxylic acid and polyhydric alcohol.

  Examples of polyvalent carboxylic acids include terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, naphthalenedicarboxylic acid, and other aromatic carboxylic acids, maleic anhydride, fumaric acid, succinic acid, alkenyl Examples thereof include aliphatic carboxylic acids such as succinic anhydride and adipic acid, and alicyclic carboxylic acids such as cyclohexanedicarboxylic acid. These polyvalent carboxylic acids can be used alone or in combination. Of these polyvalent carboxylic acids, it is preferable to use aromatic carboxylic acids, and in order to take a crosslinked structure or a branched structure in order to ensure good fixability, tricarboxylic or higher carboxylic acids (trimerits) It is preferable to use an acid or an acid anhydride thereof in combination.

  Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, glycerin, and other aliphatic diols, cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A And aromatic diols such as bisphenol A ethylene oxide adduct and bisphenol A propylene oxide adduct. One or more of these polyhydric alcohols can be used. Among these polyhydric alcohols, aromatic diols and alicyclic diols are preferable, and among these, aromatic diols are more preferable. In order to secure good fixing properties, a trihydric or higher polyhydric alcohol (glycerin, trimethylolpropane, pentaerythritol) may be used in combination with the diol in order to take a crosslinked structure or a branched structure.

  In addition, monocarboxylic acid and / or monoalcohol is further added to the polyester resin obtained by polycondensation of polycarboxylic acid and polyhydric alcohol to esterify the hydroxyl group and / or carboxyl group at the polymerization terminal. The acid value of the polyester resin may be adjusted. Examples of the monocarboxylic acid include acetic acid, acetic anhydride, benzoic acid, trichloroacetic acid, trifluoroacetic acid, propionic anhydride and the like, and examples of the monoalcohol include methanol, ethanol, propanol, octanol, 2-ethylhexanol, and trifluoroethanol. , Trichloroethanol, hexafluoroisopropanol, phenol and the like.

  The polyester resin can be produced by subjecting the polyhydric alcohol and polyhydric carboxylic acid to a condensation reaction according to a conventional method. For example, the above polyhydric alcohol and polyvalent carboxylic acid, if necessary, a catalyst, and blended in a reaction vessel equipped with a thermometer, a stirrer, a flow-down condenser, and in the presence of an inert gas (such as nitrogen gas), Heat at 150 to 250 ° C. to continuously remove by-product low-molecular compounds out of the reaction system, stop the reaction when a predetermined acid value is reached, cool, and obtain the desired reactant Can be manufactured.

  Examples of the catalyst used for the synthesis of this polyester resin include esterification catalysts such as organic metals such as dibutyltin dilaurate and dibutyltin oxide, and metal alkoxides such as tetrabutyl titanate. The amount of such a catalyst added is preferably 0.01 to 1% by weight based on the total amount of raw materials.

(Shell layer)
In the toner according to the exemplary embodiment, the shell layer covering the core particles has a glass transition temperature of 65 ° C. or higher and a volume average particle size of 20 to 800 nm mainly for the purpose of imparting heat storage properties and filming resistance. Amorphous resin fine particles that are in the range are included.

  If inorganic metal fine particles or the like are used in the shell layer for the purpose of imparting heat storage properties, the hardness of the toner surface is excessively increased and the wear of the photoreceptor is likely to be promoted. Further, from the viewpoint of selecting a resin that does not inhibit charging characteristics, it is preferable to use amorphous resin fine particles.

  As the main component of the amorphous resin fine particles used for the shell layer, a resin similar to the amorphous resin used for core particle production can be suitably used (see the above-mentioned item of amorphous resin), Of these, polyesters, styrenes, and acrylics are preferable, and polyesters are more preferable. Amorphous resin fine particles are suitably used in the state of a dispersion because the shell layer is formed in the liquid.

  Since the amorphous resin fine particles used for forming the shell layer are excellent in hardness, strength, heat resistance, and solvent resistance, the glass transition temperature is preferably 65 ° C. or higher, more preferably higher than 80 ° C., 100 More preferably, the temperature is higher than 200 ° C., particularly preferably 200 ° C. or higher. Further, the amorphous resin fine particles are preferably amorphous cross-linked fine particles (organic cross-linked fine particles), and particularly preferably amorphous cross-linked fine particles (organic cross-linked fine particles) having no softening point. When the glass transition temperature of the amorphous resin constituting the amorphous resin fine particles is less than 65 ° C., sufficient heat storage properties cannot be obtained, causing blocking in the developing machine and filming to the photoreceptor. In the development process, white spot defects are likely to occur.

  The volume average particle diameter of the amorphous resin fine particles used for forming the shell layer is preferably in the range of 20 to 800 nm, more preferably in the range of 40 to 500 nm, still more preferably in the range of 40 to 200 nm. A range of ˜100 nm is particularly preferred, and a range of 40 to 80 nm is particularly preferred. When the particle size of the resin fine particles is less than 20 nm, not only is it difficult to produce the fine particles themselves, but also the core components not only cause aggregation of toners, particularly in a high temperature and high humidity environment, but also the core components on the surface. Exposure becomes noticeable, and the storage property between toners in a high temperature and high humidity environment and the filming resistance to the photoreceptor are deteriorated. On the other hand, if it exceeds 800 nm, not only the adhesion to the surface of the core particle is deteriorated and the heat storage property is deteriorated, but also the wear of the photosensitive member is promoted. The glossiness of the deteriorates. The particle size distribution is preferably relatively narrow, specifically in the range of 10 to 1000 nm, and more preferably in the range of 20 to 200 nm.

  The toner according to this embodiment is formed by attaching amorphous resin fine particles to the surface of core particles containing a binder resin and a colorant. The content of the amorphous resin fine particles is based on the weight of the core particles. The range is preferably 5 to 25% by weight, more preferably 7 to 20% by weight, and still more preferably 7 to 16% by weight. When the content of the amorphous resin fine particles is less than 5% by weight, the effects of heat storage and prevention of filming on the photoreceptor are insufficient. On the other hand, if it exceeds 25% by weight, the contribution of the amorphous resin fine particles is increased, the low-temperature fixability is hindered, and the image gloss is lowered.

  Moreover, it is preferable that the shell layer is not a complete continuous layer for the purpose of promoting the exudation of the core particles during fixing. In the present embodiment, since the glass transition temperature of the amorphous fine particles is 65 ° C. or higher, the shell layer is not completely melted at the time of forming the shell layer, so that the shell layer is unlikely to be a complete continuous layer. When the amorphous resin fine particles are united to form a continuous layer, exudation of the core component having low-temperature fixability is hindered, and the fixing temperature may be increased. From this viewpoint, the coverage of the core particles with the amorphous resin fine particles is preferably in the range of 30% to 90%, and more preferably in the range of 50% to 80%. This coverage can be obtained by averaging the shortest distance between the core and the shell layer with 50 toners from the contrast difference using an X-ray photoelectron spectrometer manufactured by JEOL.

  Further, the film thickness of the shell layer is preferably in the range of 10 nm to 1000 nm, and more preferably in the range of 20 nm to 800 nm. When the film thickness is larger than 1000 nm, the exudation of the core component having low temperature fixability is inhibited, and the fixing temperature may be increased. If the film thickness is smaller than 10 nm, the effect of preventing heat storage and preventing filming on the photoreceptor may be insufficient. In addition, this film thickness can be calculated | required by implementing cross-sectional observation using the Hitachi electron transmission microscope apparatus.

(Amorphous cross-linked fine particles)
The amorphous resin fine particles according to this embodiment are preferably amorphous cross-linked fine particles, and particularly preferably amorphous cross-linked fine particles having no softening point. Amorphous crosslinked fine particles are fine particles of the above-mentioned amorphous resin and having a crosslinked structure. “No softening point” means that no clear endothermic peak is observed in the differential scanning calorimetry (DSC) of the resin, core particles or toner. Further, “a clear endothermic peak is not recognized” specifically means that the temperature from the onset point to the peak top of the endothermic peak exceeds 50 ° C. Amorphous crosslinked resin often decomposes at, for example, 400 ° C. to 500 ° C. before being softened in the DSC measurement. A mixed system of amorphous crosslinked fine particles and amorphous resin fine particles can also be used.

  Amorphous crosslinked fine particles basically do not have a softening point, but if they have a softening point, that is, if the crosslinking is sparse enough to have a glass transition temperature, the temperature rise during storage or local in-flight When this occurs, the toner may cause blocking, and sufficient heat storage properties may not be obtained. Further, the amorphous crosslinked fine particles used for forming the shell layer are allowed to be deformed to some extent by the heat applied in the flushing process or kneading, but it is not preferable to melt and flow. Therefore, it is preferable to use amorphous cross-linked fine particles having excellent hardness, strength, heat resistance, and solvent resistance and having substantially no softening point for the shell layer. Inorganic metal fine particles also have no softening point. However, if inorganic metal fine particles such as silica that do not have a softening point are used in the shell layer, the hardness of the toner surface becomes too high, and the wear of the photoreceptor is promoted. End up. Therefore, it is preferable to use amorphous crosslinked fine particles as fine particles having an appropriate hardness.

  In this embodiment, since the amorphous crosslinked fine particles have substantially no softening point, the shell layer is not completely melted at the time of forming the shell layer, and the shell layer is unlikely to be a complete continuous layer. It is stronger than the case of using amorphous resin microparticles having

  Examples of the amorphous crosslinked fine particles include vinyl-based, styrene-based, (meth) acrylic-based, ester-based, amide-based, melamine-based, ether-based, and epoxy-based amorphous crosslinked fine particles. Vinyl-based and styrene-based are preferable, and vinyl-based is more preferable.

  The method for producing the amorphous crosslinked fine particles is not particularly limited and can be produced using a conventionally known method. For example, as methods for producing addition-polymerized amorphous crosslinked fine particles, “Fourth Edition Experimental Chemistry Course 28 Polymer Synthesis” (Maruzen Co., Ltd.), “Fourth Edition Experimental Chemistry Course 29 Polymer Materials” (Maruzen) Co., Ltd.), "New Polymer Experiments 4 Synthesis and Reaction of Polymers (1) Synthesis of Addition Polymers" (Kyoritsu Publishing Co., Ltd.), "New Polymer Experiments 4 Polymer Synthesis and Reactions (3) Fine particles having a core-shell structure produced by suspension polymerization, emulsion polymerization, dispersion polymerization or the like described in “Reaction and Decomposition of Polymer” (Kyoritsu Publishing Co., Ltd.) and the like can also be used. Also, the polymerization granulation method described in JP-A-7-18003, JP-A-5-222267, JP-A-5-43608, JP-A-7-228611, and the like can be used.

  As methods for producing condensed amorphous crosslinked fine particles, methods described in JP-A-5-70600, JP-A-7-248639 and the like, and JP-A-63-25664 are described. The in-liquid drying method can also be preferably used.

  The monomer constituting the addition-polymerized amorphous cross-linked fine particles is not particularly limited, and is conventionally known as described in, for example, “Polymer Data Handbook: Basics” (Edition of Polymer Society: Baifukan). These monomer components can be used alone or in combination. Moreover, what was described in the said gazette etc. can also be used. Specifically, for example, vinyl monomers include olefin compounds such as ethylene and propylene, and styrene monomers include styrene, alpha-methyl styrene, vinyl naphthalene, 2-methyl styrene, 3-methyl styrene, Halogen substitution such as alkyl-substituted styrenes with alkyl chains such as methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene Fluorine-substituted styrene such as styrene, 4-fluorostyrene, 2,5-difluorostyrene and the like can be mentioned.

  (Meth) acrylic acid monomers include (meth) acrylic acid, n-methyl (meth) acrylate, n-ethyl (meth) acrylate, n-propyl (meth) acrylate, and (meth) acrylic acid. n-butyl, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, n-decyl (meth) acrylate, ( (Meth) acrylic acid n-dodecyl, (meth) acrylic acid n-lauryl, (meth) acrylic acid n-tetradecyl, (meth) acrylic acid n-hexadecyl, okdadecyl, (meth) acrylic acid n-isopropyl, (meth) acrylic N-isobutyl acid, t-butyl (meth) acrylate, isopentyl (meth) acrylate, amyl (meth) acrylate, neo (meth) acrylate Nethyl, isohexyl (meth) acrylate, isoheptyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, phenyl (meth) acrylate, biphenyl (meth) acrylate, (meth) acryl Diphenylethyl acid, t-butylphenyl (meth) acrylate, terphenyl (meth) acrylate, cyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, (meth ) Cyclohexyl diethylaminoethyl acrylate, methoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (meth) acrylonitrile, (meth) acrylamide and the like.

  Other vinyl monomer components having crosslinkability include diene compounds such as isoprene and butadiene, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; diacrylates linked by alkyl chains, and 1,3-butylene glycol diene. Acrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopenthiglycol diacrylate, and acrylates of the above compounds replaced with methacrylate; ether Diacrylate compounds linked by an alkyl chain containing a bond, such as diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 400 dia Acrylate, polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate, and acrylates of the above compounds replaced with methacrylates; diacrylate compounds linked by chains containing aromatic groups and ether linkages, such as polyoxy Ethylene (2) -2,2-bis (4-hydroxyphenyl) propane diacrylate, polyoxyethylene (4) -2,2-bis (4-hydroxyphenyl) propane diacrylate and methacrylates of the above compounds The polyfunctional cross-linking agents include pentaelsriol triacrylate, trimethylolpropane triacrylate, trimethylolpropane triacrylate, tetramethylrollmethane tetraacrylate, oligoester Acrylate, and the like are preferably used those obtained by changing the acrylate methacrylates or more compounds.

  Among these monomers, (meth) acrylic acid having a carboxyl group, hydroxyl group, amide group, 2-hydroxyethyl (meth) acrylate, acrylamide, etc. are highly soluble in an aqueous medium. When an aqueous medium is used, these may form ultrafine particles alone. In such a case, it is preferable to select the type of the dispersant or the emulsifier, or to use these monomers alone or after polymerizing with other monomers to a molecular weight of about several thousand or less.

  The monomer constituting the polycondensation amorphous cross-linked fine particles is not particularly limited. For example, a monomer component as described in “Polymer Data Handbook: Basic Edition” (Edition of Polymer Society: Baifukan) There are conventionally known divalent or trivalent or higher carboxylic acids and divalent or trivalent or higher alcohols. Moreover, what was described in the said gazette etc. can also be used. Specific examples of these monomer components include divalent carboxylic acids such as succinic acid, glutaric acid, adipic acid, peric acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, and naphthalene-2. , 6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, cyclohexanedicarboxylic acid, malonic acid, mesaconic acid, and other dibasic acids, and their anhydrides and their lower alkyl esters, maleic acid, fumaric acid, itaconic acid And aliphatic unsaturated dicarboxylic acids such as citraconic acid. 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.

  Examples of the divalent alcohol include bisphenol A, hydrogenated bisphenol A, bisphenol A ethylene oxide and / or propylene oxide compound, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, ethylene glycol, diethylene glycol, propylene Examples include glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and neopentyglycol. Examples of the trihydric or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaelsitol and the like. These may be used individually by 1 type and may use 2 or more types together. If necessary, monovalent acids such as acetic acid and benzoic acid, and monovalent alcohols such as cyclohexanol and benzyl alcohol can be used for the purpose of adjusting the acid value and the hydroxyl value.

  As the amorphous cross-linked fine particles, those appropriately synthesized by the above production method may be used, or commercially available ones may be used. Examples of commercially available products include those described in “New Developments in Fine Particle Polymers” (Edited by Toray Research Center, Inc.). Among them, the Microgel series of Nippon Paint Co., Ltd., JSR Co., Ltd. STADEX series, Soken Chemical's MR series, MP series and the like.

(Coloring agent)
The colorant used in the present embodiment is not particularly limited as long as it is a known colorant. For example, carbon black such as furnace black, channel black, acetylene black, and thermal black, inorganic such as bengara, bitumen, and titanium oxide. Pigments, Fast Yellow, Disazo Yellow, Pyrazolone Red, Chelate Red, Brilliant Carmine, Para Brown and other azo pigments, copper phthalocyanine, metal-free phthalocyanine and other phthalocyanine pigments, flavantron yellow, dibromoanthrone orange, perylene red, quinacridone red, di Examples thereof include condensed polycyclic pigments such as oxazine violet. Chrome Yellow, Hansa Yellow, Benzidine Yellow, Slen Yellow, Quinoline Yellow, Permanent Orange GTR, Pyrarozone Orange, Vulcan Orange, Watch Young Red, Permanent Red, Dupont Oil Red, Resol Red, Rhodamine B Lake, Lake Red C Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Phthalocyanine Green, Malachite Green Oxalate, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment 57: 1, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 17, C.I. I. Pigment blue 15: 1, C.I. I. Examples thereof include various pigments such as CI Pigment Blue 15: 3, and these can be used alone or in combination of two or more.

  In the toner for developing an electrostatic charge image according to the exemplary embodiment, the content of the colorant is preferably in the range of 1 to 30 parts by mass with respect to 100 parts by mass of the binder resin. It is also effective to use a colorant that has been surface-treated accordingly, or to use a pigment dispersant. By appropriately selecting the type of the colorant, yellow toner, magenta toner, cyan toner, black toner and the like can be obtained.

(Release agent)
The release agent used in this embodiment is not particularly limited as long as it is a known release agent. For example, low molecular weight polyolefins such as polyethylene, polypropylene, and polybutene; silicones having a softening point by heating; oleic acid Fatty acid amides such as amide, erucic acid amide, ricinoleic acid amide, stearic acid amide; plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil; animal waxes such as beeswax; montan wax And mineral / petroleum waxes such as ozokerite, ceresin, paraffin wax, microcrystalline wax, and Fischer-Tropsch wax; and ester waxes such as fatty acid esters, montanic acid esters, and carboxylic acid esters. These release agents may be used alone or in combination of two or more.

  The melting point of the release agent is preferably 60 ° C. or higher, more preferably 70 ° C. or higher, from the viewpoint of storage stability. Further, from the viewpoint of offset resistance at low temperatures, it is preferably 110 ° C. or lower, and more preferably 100 ° C. or lower. Furthermore, from the viewpoint of offset resistance at high temperatures, a release agent having a melting point of 100 ° C. or higher can be used in combination.

  The content of the release agent is preferably in the range of 1 to 30 parts by weight and more preferably in the range of 2 to 20 parts by weight with respect to 100 parts by weight of the binder resin. When the content of the release agent is less than 1 part by weight, there is no effect of adding the release agent, and hot offset at a high temperature may be caused. On the other hand, when the amount exceeds 30 parts by weight, the charging property is adversely affected, and the mechanical strength of the toner is reduced. Therefore, the toner is easily destroyed by stress in the developing machine, and may cause carrier contamination. Further, when used as a color toner, a domain tends to remain in a fixed image, which may cause a problem that OHP transparency is deteriorated.

(Other additives)
Various components such as an internal additive, a charge control agent, inorganic powder (inorganic fine particles), and organic fine particles can be further added to the toner according to the exemplary embodiment as necessary.

  Examples of the internal additive include metals such as ferrite, magnetite, reduced iron, cobalt, nickel, and manganese, alloys, and magnetic materials such as compounds containing these metals.

  Examples of the charge control agent include quaternary ammonium salt compounds, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium, triphenylmethane pigments, salicylic acid metal salts, metal-containing azo compounds, and the like.

  The inorganic powder is added mainly for the purpose of adjusting the viscoelasticity of the toner. For example, silica, alumina, titania, calcium carbonate, magnesium carbonate, calcium phosphate, cerium oxide, etc. Examples thereof include all inorganic fine particles used as an external additive on the toner surface.

  Examples of the external additive other than the amorphous resin fine particles added to the toner surface include the following inorganic fine particles and organic fine particles.

  Examples of the inorganic fine particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, cerium chloride, Examples include Bengala, chromium oxide, cerium oxide, antimony trioxide, magnesium oxide, zirconium oxide, silicon carbide, and silicon nitride. Among them, silica fine particles and titanium oxide fine particles are preferable, and hydrophobized fine particles are particularly preferable.

  Inorganic fine particles are generally used for the purpose of improving fluidity. The primary particle diameter of the inorganic fine particles is preferably in the range of 1 to 200 nm, and the addition amount is preferably in the range of 0.01 to 20 parts by weight with respect to 100 parts by weight of the toner.

  Organic fine particles are generally used for the purpose of improving cleaning properties and transfer properties, and specific examples include polystyrene, polymethyl methacrylate, polyvinylidene fluoride, and the like.

<Method for producing toner for developing electrostatic image>
The core particles of the toner according to the exemplary embodiment can be manufactured by agglomeration coalescence method, dissolution suspension granulation, dissolution suspension emulsification / aggregation coalescence method, and suspension polymerization method. From the viewpoint, it is preferable to employ an aggregation and coalescence method in an aqueous medium.

  In the case of the aggregation coalescence method, the resin particles are generally produced by emulsion polymerization or the like. Using a resin dispersion of the resin particles based on an ionic surfactant, a colorant dispersed with an ionic surfactant having a polarity opposite to that of the resin particles and magnetic metal fine particles are mixed to cause heteroaggregation. Next, the resin fine particles are added to the surface, adhered to the surface and agglomerated to form toner-aggregated particles, and then heated to a temperature higher than the glass transition temperature of the resin to fuse and coalesce the aggregates, wash, and dry The toner shape is preferably from indefinite to spherical.

  Further, even if the process is performed by mixing and agglomerating all at once, in the agglomeration step, the balance of the amount of the ionic dispersant of each polarity is initially shifted in advance, for example, an inorganic material such as calcium nitrate. This is ionically neutralized using a polymer of a metal salt or an inorganic metal salt such as polyaluminum chloride to form a first-stage matrix aggregation below the glass transition temperature. After stabilization, as a second stage Add a particle dispersion treated with a polarity and amount of dispersant that compensates for the imbalance, and if necessary, heat it slightly below the glass transition temperature of the resin contained in the matrix or additional particles. After stabilization at a high temperature, the particles added in the second stage of agglomeration by heating above the glass transition temperature may be combined and adhered to the surface of the base agglomerated particles.Furthermore, the stepwise operation of aggregation may be repeated several times.

  In the case of the dissolution suspension method, the binder resin component, the colorant, the magnetic metal fine particles, and the release agent are once dissolved in an organic solvent such as ethyl acetate, and then not dissolved, for example, in an aqueous solvent. In addition, an inorganic fine particle such as calcium phosphate and an organic dispersant such as polyvinyl alcohol and sodium polyacrylate are dispersed by applying a mechanical shearing force with a homogenizer such as a TK homomixer. Next, this is added to, for example, a 1M aqueous hydrochloric acid solution to dissolve and remove the dispersant component, followed by solid-liquid separation with Nutsche or the like using a filter paper, and then the solvent component remaining in the particles is distilled off.

  In the case of dissolution emulsification, after dissolving the binder resin component in a solvent such as ethyl acetate, it is subjected to mechanical shear force by a homogenizer such as a TK homomixer in the presence of an ionic surfactant. For example, emulsified resin fine particles are obtained by the surface activity of an ionic surfactant such as sodium alkylbenzene sulfonate, and then the remaining solvent is distilled off by distillation under reduced pressure to obtain a resin fine particle dispersion. Thereafter, the same operation as in the agglomeration method is performed.

  Further, in the case of suspension granulation, a polymerizable monomer is preliminarily polymerized in advance, and a polymer solution having an Mw of 3000 to 15000 determined by GPC measurement is produced, and then magnetic metal fine particles, a release agent, a colorant are added thereto. In addition, after adding a polymerizable monomer and a polymerization initiator, suspending it by applying mechanical shearing force in the presence of an inorganic or organic dispersing agent, applying thermal shearing force while applying stirring shear. Polymer particles can also be obtained by applying. In this case, it is basically the same as the suspension granulation, but by setting the Mw of the prepolymer from 3000 to 15000, not only a viscosity suitable for fixing and granulation can be obtained but also produced. The toner Mw can be controlled without a chain transfer agent.

  Further, in the case of suspension polymerization, for example, after dissolving in a polymerizable monomer such as styrene, acrylic acid ester, acrylic acid, etc., it is heated to 55 ° C. in the presence of an inert gas, and completely released. After the material is dissolved, a polymerization initiator such as azobisisobutyl acrylate is added thereto. Next, this is added to an aqueous dispersion of an inorganic dispersant such as calcium phosphate that has been heated to 60 ° C. in advance, and suspended and granulated by applying mechanical shearing with a homogenizer such as a TK homomixer to obtain a dispersion. . A temperature higher than the 10-hour half-life temperature of the polymerization initiator is given to this, and the reaction is carried out for 6 hours. After completion of the reaction, the mixture is cooled to room temperature, and an acid such as hydrochloric acid is added to dissolve and remove the dispersant component. Thereafter, this is washed with sufficient pure water, and when the pH of the filtrate becomes neutral, solid-liquid separation is performed using a filter medium such as No5A filter paper to obtain particles.

(Method for forming core particles)
A method of forming core particles containing a binder resin containing at least one of a crystalline polyester resin and an amorphous resin and a colorant by an aggregation coalescence method (emulsion aggregation method) will be specifically described. The method of forming the core particles by the emulsion aggregation method is at least one of the crystalline polyester resin and the amorphous resin, and if necessary, other binder resin (hereinafter sometimes referred to simply as “polymer”). An emulsification step of emulsifying the emulsion particles (droplets), an aggregation step of forming aggregates of the emulsion particles (droplets), and a fusion step of fusing the aggregates and heat-fusion. Including.

[Emulsification process]
The emulsification step will be described by taking a case where a crystalline polyester resin is used as a binder resin as an example. In the emulsification step, the emulsified particles (droplets) of the polymer are subjected to a shearing force in a solution obtained by mixing an aqueous medium and a mixed liquid (polymer liquid) containing a crystalline polyester resin and other binder resin as necessary. It is formed by giving.

  At that time, the viscosity of the polymer liquid can be lowered to form emulsified particles by heating or by dissolving a polymer such as a crystalline polyester resin in an organic solvent. Moreover, a dispersing agent can also be used in order to stabilize emulsified particles and prevent thickening of the aqueous medium. Hereinafter, such a dispersion of emulsified particles may be referred to as a “resin particle dispersion”.

  Examples of the organic solvent include ethyl acetate, toluene, and the like, and can be appropriately selected and used depending on the type and structure of the crystalline polyester resin.

  As the usage-amount of the said organic solvent, it is preferable that it is the range of 50-5000 mass parts with respect to 100 mass parts of total amounts of a polymer, and it is more preferable that it is the range of 120-1000 mass parts.

  Examples of the dispersant include water-soluble polymers such as polyvinyl alcohol, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, sodium polyacrylate, and sodium polymethacrylate, sodium dodecylbenzenesulfonate, sodium octadecylsulfate, and oleic acid. Anionic surfactants such as sodium, sodium laurate, potassium stearate, cationic surfactants such as laurylamine acetate, stearylamine acetate, lauryltrimethylammonium chloride, zwitterionic surfactants such as lauryldimethylamine oxide, Such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkylamine, etc. Anion surfactants such as surfactants, tricalcium phosphate, aluminum hydroxide, calcium sulfate, calcium carbonate, and inorganic compounds such as barium carbonate.

  When an inorganic compound is used as the dispersant, a commercially available product may be used as it is. However, for the purpose of obtaining fine particles, a method of producing fine particles of an inorganic compound in the dispersant may be employed. As the usage-amount of the said dispersing agent, the range of 0.01-20 mass parts is preferable with respect to 100 mass parts of polymers.

  In the emulsification step, the crystalline polyester resin is copolymerized with a dicarboxylic acid having a sulfonic acid group (that is, a suitable amount of a dicarboxylic acid-derived constituent component having a sulfonic acid group is included in the acid-derived constituent component). ) And a dispersing agent such as a surfactant, or emulsified particles can be formed without using a dispersing agent.

  Examples of the emulsifier used when forming the emulsified particles include a homogenizer, a homomixer, a pressure kneader, an extruder, and a media disperser. The size of the emulsified particles (droplets) of the polymer such as crystalline polyester resin is preferably in the range of 0.01 μm to 1 μm in terms of the average particle size (volume average particle size), and in the range of 0.03 μm to 0.3 μm. Is more preferable, and the range of 0.03 μm to 0.4 μm is even more preferable.

  In addition, a colorant can be mixed in the polymer liquid before forming the polymer emulsified particles in the emulsification step. When the colorant is mixed in the polymer liquid in the emulsification step, for example, the colorant or the organic solvent dispersion of the colorant can be mixed with the organic solvent solution of the polymer. The colorant used is as described above in the section “Colorant” of the toner for developing an electrostatic image.

  If necessary, prepare an aqueous dispersion of a colorant using a surfactant, or prepare an organic solvent dispersion of a colorant using a dispersant, before the next aggregation step. An aqueous dispersion of a colorant or an organic solvent dispersion may be mixed with the resin particle dispersion. Hereinafter, an aqueous dispersion or an organic solvent dispersion of the colorant may be referred to as a “colorant dispersion”. As the surfactant and dispersant used for dispersion, the same dispersants as used for dispersing the polymer can be used.

  As a method for dispersing the colorant, an arbitrary method, for example, a general dispersion method such as a rotary shear type homogenizer, a ball mill having a medium, a sand mill, or a dyno mill can be used, and the method is not limited at all.

  The addition amount of the colorant is preferably in the range of 1 to 20% by mass, more preferably in the range of 1 to 10% by mass, with respect to the total amount of the polymer, in the range of 2 to 10% by mass. More preferably, it is more preferable to set it as the range of 2-7 mass%.

  In addition, the release agent which is the other component is also prepared by preparing an aqueous dispersion of the release agent using a surfactant or by preparing an organic solvent dispersion of the release agent using a dispersant. Before the next flocculation step, an aqueous dispersion of the release agent or an organic solvent dispersion may be mixed with the resin particle dispersion. Hereinafter, the aqueous dispersion or organic solvent dispersion of the release agent may be referred to as “release agent dispersion”. As the surfactant and dispersant used for dispersion, the same dispersants as used for dispersing the polymer can be used.

[Aggregation process]
In the agglomeration step, the obtained resin particle dispersion and, if necessary, the colorant dispersion and the release agent dispersion are used at a temperature near the melting point of the binder resin, here the crystalline polyester resin, and at a temperature below the melting point. Heat to aggregate to form aggregates. The heating time may be performed so that the aggregation is sufficiently performed, and for example, it may be performed for about 0.5 hours to 10 hours.

  Formation of the aggregate of the emulsified particles is performed by acidifying the pH of the emulsion under stirring. As the said pH, the range of 2-6 is preferable, The range of 2.5-5 is more preferable, The range of 2.5-4 is further more preferable. At this time, it is also effective to use a flocculant.

  As the flocculant to be used, a surfactant having a reverse polarity to the surfactant used for the dispersant, an inorganic metal salt, and a metal complex having a valence of 2 or more can be preferably used. In particular, the use of a metal complex is particularly preferable because the amount of the surfactant used can be reduced and the charging characteristics are improved.

  Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Examples thereof include inorganic metal salt polymers. Among these, an aluminum salt and a polymer thereof are particularly preferable. In order to obtain a sharper particle size distribution, the valence of the inorganic metal salt is bivalent than monovalent, trivalent than bivalent, trivalent than trivalent, and tetravalent than trivalent. The inorganic metal salt polymer is more preferable.

  The solid content concentration of the reaction solution at the time of aggregation is usually in the range of 5% by weight to 20% by weight, preferably in the range of 10% by weight to 15% by weight. When the solid content concentration of the reaction solution is less than 5% by weight or exceeds 20% by weight, aggregation may not easily occur.

[Fusion process]
In the fusion step, under the same stirring as in the aggregation step, the aggregation suspension is stopped by setting the pH of the aggregate suspension to a range of 3 to 7, and heated at a temperature equal to or higher than the melting point of the crystalline polyester resin. To fuse the aggregates.

  As the heating temperature, in the case of a crystalline polyester resin, there is no problem as long as it is equal to or higher than its melting point.

  The heating time may be performed to such an extent that the fusion is sufficiently performed, for example, about 0.5 to 10 hours.

  The fused particles obtained by fusing can be made into toner particles through a solid-liquid separation process such as filtration and, if necessary, a washing process and a drying process. In this case, in order to ensure sufficient charging characteristics and reliability as a toner, it is preferable to sufficiently wash with ion exchange water or the like in the washing step.

  In the drying step, an arbitrary method such as a normal vibration type fluidized drying method, a spray drying method, a freeze drying method, a flash jet method, or the like can be adopted. It is desirable to adjust the moisture content after drying of the toner to 1.0 mass% or less, preferably 0.5 mass% or less.

  In the fusion step, a crosslinking reaction may be performed when the crystalline polyester resin is heated to the melting point or higher, or after the fusion is completed. Moreover, a crosslinking reaction can also be performed simultaneously with aggregation. When the crosslinking reaction is performed, for example, an unsaturated sulfonated crystalline polyester resin obtained by copolymerizing a double bond component as a binder resin is used, and a radical reaction is caused to the resin to introduce a crosslinked structure. . At this time, the following polymerization initiator can be used.

  Examples of the polymerization initiator include t-butyl peroxy-2-ethylhexanoate, cumyl perpivalate, t-butyl peroxylaurate, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, di-t. -Butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane 1,1-bis (t-butylperoxy) cyclohexane, 1,4-bis (t-butylperoxycal) Nyl) cyclohexane, 2,2-bis (t-butylperoxy) octane, n-butyl 4,4-bis (t-butylperoxy) valerate, 2,2-bis (t-butylperoxy) butane, , 3-bis (t-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylper) Oxy) hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, di-t-butyldiperoxyisophthalate, 2,2-bis (4,4-di-t-butylperoxy) (Cyclohexyl) propane, di-t-butylperoxy α-methylsuccinate, di-t-butylperoxydimethylglutarate, di-t-butylperoxyhexahydroterephthalate Rate, di-t-butylperoxyazelate, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, diethylene glycol-bis (t-butylperoxycarbonate), di-t-butylper Oxytrimethyl adipate, tris (t-butylperoxy) triazine, vinyltris (t-butylperoxy) silane, 2,2'-azobis (2-methylpropionamidine dihydrochloride), 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine], 4,4′-azobis (4-cyanovaleric acid) and the like.

  These polymerization initiators can be used alone or in combination of two or more. The amount and type of the polymerization initiator are selected depending on the amount of unsaturated sites in the polymer and the type and amount of the coexisting colorant.

  The polymerization initiator may be mixed with the polymer in advance before the emulsification step, or may be incorporated into the aggregate in the aggregation step. Further, it may be introduced after the fusion step or after the fusion step. In the case of introduction after the aggregation step, the fusion step, or the fusion step, a solution in which the polymerization initiator is dissolved or emulsified is added to a particle dispersion (resin particle dispersion or the like). These polymerization initiators may be added with known crosslinking agents, chain transfer agents, polymerization inhibitors and the like for the purpose of controlling the degree of polymerization.

(Shell layer forming process)
Next, a method for forming the shell layer will be described. In the toner according to the exemplary embodiment, a method for forming a shell layer includes: an agglomeration step in which amorphous resin fine particles are adhered to the core particles to form amorphous resin-adhered particles; and amorphous resin-adhered particles. And a melting step of forming a shell layer by heating. About the formation method of the shell layer which has an amorphous resin fine particle as a main component, it is preferable to carry out in water from a viewpoint of productivity.

  The shell layer is formed by adding an amorphous cross-linked fine particle dispersion during granulation by the aggregation coalescence method, dissolution suspension granulation, dissolution suspension emulsification / aggregation coalescence method, and suspension polymerization method as described above. The same process may be performed simultaneously, or may be performed as a separate process after the core particles are produced.

  When the shell layer formation is performed as the same process performed by adding the amorphous resin fine particle dispersion during granulation of the core particles, the addition timing of the amorphous resin fine particle dispersion is determined depending on the material system used for core particle preparation. It may be added simultaneously or later. However, in this case, since the shell is formed by largely depending on the balance of hydrophilicity / hydrophobicity, applicable material systems may be limited. Therefore, it is preferable to form the shell layer as a separate process in the aqueous medium after the core particles are produced.

  If the shell layer is formed during the granulation of the core particles, the amorphous resin fine particles are contained in the core particles and the coverage is lowered, which may adversely affect the toner characteristics such as heat storage. is there. In addition, if the shell layer is formed during the granulation of the core particles, the unreacted core particle components are taken into the shell layer and the heat resistance of the shell layer is lowered, mainly affecting toner properties such as heat storage. May affect. Therefore, by performing the core particle formation and the shell layer formation in separate processes, it is possible to form a shell layer having a uniform film thickness and coverage on the core particles, and the heat storage property of the toner is improved.

  Specifically, the core particle formation and the shell layer formation are performed in different processes. Specifically, first, core particles are formed by an emulsification step, an aggregation step, and a fusion step, and the core particles are once taken out by filtration or the like and not yet washed. After removing the core particle component of the reaction and dispersing in the solvent again, the shell layer component containing amorphous resin fine particles is added, and the shell layer is formed by the aggregation process and the melting process.

  In the shell layer forming step, the solid content concentration during coating is preferably in the range of 10 to 50% by weight, more preferably in the range of 20 to 50% by weight, and in the range of 30 to 50% by weight. Is more preferable. When the weight is 10% or less, not only the dispersion stability is low, but also the dispersion stability is lowered, so that the amorphous resin fine particles are not sufficiently adhered to the core particle surface. On the other hand, when the solid content concentration is 50% by weight or more, an increase in slurry viscosity at the time of adhesion causes a poor stirring, resulting in generation of coarse powder.

  As described above, the solid content concentration of the reaction liquid in the agglomeration step for core particle formation is usually in the range of 5 wt% to 20 wt%, preferably in the range of 10 wt% to 15 wt%. In the step, the range is preferably 10 to 50% by weight, more preferably 20 to 50% by weight, and further preferably 30 to 50% by weight. Therefore, in the method in which the shell layer is formed during the granulation of the core particles, the optimum solid content concentration differs, so that the aggregation of the core particle components or the shell layer formation is insufficient depending on the employed solid content concentration. Also in this respect, it is preferable that the core particle formation and the shell layer formation are performed in separate processes, and an optimum solid content concentration is adopted in each step. Specifically, the agglomeration step for forming the core particles is preferably performed in a solid content concentration range of 10 to 15% by weight, and the shell layer forming step is preferably performed in a range of 30 to 50% by weight.

  Further, in order to allow the amorphous resin fine particles to adhere to the surface of the core particles, it is desirable that the hydrophilicity / hydrophobicity (wetting property and solubility parameter (SP value)) of the core particles and the amorphous resin fine particles are approximately the same. However, in general, amorphous resin fine particles, especially crosslinked amorphous fine particles, are water-insoluble and have strong hydrophobic properties, so they have poor affinity with highly hydrophilic core particles, and the core particle surface It is difficult for the amorphous resin fine particles to adhere to the surface. Therefore, when the amorphous resin fine particles adhere to the surface of the core particles, it is preferable that the concentration of the amorphous resin fine particles relative to the core particles is higher. On the other hand, when the core particles are aggregated, aggregation is more likely to occur when the solid content concentration is lower. Therefore, by performing the core particle formation and the shell layer formation in separate processes as described above and adopting the optimum solid content concentration in each step, it becomes possible to form a shell layer with a good coverage. .

  The SP value of the core particles is usually about 8.5 to 10, and the SP value of the amorphous resin fine particles is about 9.0 to 11.

  In the formation of the shell layer, the slurry liquid may be heated for the purpose of obtaining a strong shell layer after adding the amorphous resin fine particle dispersion to the slurry liquid after the core particle granulation. At this time, it is important to heat at or below the melting point or glass transition temperature of the binder resin of the core particles. When the heating temperature is too high, not only coarse powder is generated, but also the core component is eluted on the surface of the shell layer, thereby deteriorating charging characteristics and heat storage properties.

  In the formation of the shell layer, a flocculant may be used for the purpose of promoting the coating of the amorphous resin fine particles. As the flocculant, the flocculant species described later is preferably used. Further, the timing of adding the flocculant may be before or after the addition of the amorphous resin fine particles.

  In the preparation of the toner shell layer of the present embodiment, the amount of the amorphous crosslinked fine particles added is preferably in the range of 5 to 25% by weight with respect to the weight of the core particles as described above, and is 7 to 20% by weight. Is more preferable, and it is further more preferable that it is the range of 7-16 weight%. When the addition amount is less than 5% by weight, the heat storage property becomes insufficient, and blocking is likely to occur in the actual machine. When the addition amount exceeds 25% by weight, the heat storage property is not a problem, but the charging characteristics and the low-temperature fixability are hindered.

  Further, in the present embodiment, as the component of the shell layer, amorphous resin fine particles having other softening points may be used in combination with the amorphous crosslinked fine particles. As the amorphous resin fine particles, fine particles mainly composed of the above-described amorphous resin (see the item of amorphous resin) can be suitably used.

  When the amorphous resin fine particles having other softening points are used in combination, the addition amount of the amorphous resin fine particles is preferably 5 to 80% by weight with respect to the amorphous crosslinked fine particles. If it is 80% by weight or more, the properties of the amorphous resin fine particles are expressed more strongly, and any of charging characteristics, low-temperature fixability, and heat storage properties may be deteriorated.

  As the aggregating agent used in the aggregating step, a surfactant having a polarity opposite to that of the surfactant used for the dispersing agent, an inorganic metal salt, or a divalent or higher-valent metal complex can be preferably used. In particular, the use of a metal complex is particularly preferable because the amount of the surfactant used can be reduced and the charging characteristics are improved.

  Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Examples thereof include inorganic metal salt polymers. Of these, aluminum salts and polymers thereof are particularly preferred. In order to obtain a sharper particle size distribution, the valence of the inorganic metal salt is bivalent than monovalent, trivalent than bivalent, trivalent than trivalent, and tetravalent than trivalent. The inorganic metal salt polymer is more suitable.

  Agglomerated particles are formed by adding a flocculant at room temperature under stirring with a rotary shearing homogenizer to make the pH of the raw material dispersion acidic. Further, in order to suppress rapid aggregation due to heating, it is preferable to adjust the pH at the stage of stirring and mixing at room temperature, and add a dispersion stabilizer as necessary.

(Washing and drying process)
When toner particles are prepared using the aggregation coalescence method, dissolution suspension granulation, dissolution suspension emulsification / aggregation coalescence method, and suspension polymerization method, the dispersant is added with an aqueous solution of strong acid such as hydrochloric acid, sulfuric acid, nitric acid, etc. After the removal, it is rinsed with ion exchange water or the like until the filtrate becomes neutral, and a desired toner is obtained through an optional washing step, solid-liquid separation step, and drying step.

  In the drying process, an arbitrary method such as a normal vibration type fluidized drying method, a spray drying method, a freeze drying method, or a flash jet method can be adopted. It is desirable that the toner particles have a moisture content after drying of 1.0% or less, preferably 0.5% or less.

<Physical properties of toner for developing electrostatic image>
The volume average particle size of the electrostatic image developing toner according to this embodiment is preferably in the range of 4 μm to 8 μm, more preferably in the range of 5 μm to 7 μm, and the number average particle size is in the range of 3 μm to 7 μm. Is preferable, and the range of 4 μm to 6 μm is more preferable.

  The volume average particle diameter and the number average particle diameter can be measured by measuring with an aperture diameter of 50 μm using a Coulter Counter [TA-II] type (manufactured by Coulter). At this time, the measurement is performed after the toner is dispersed in an electrolyte aqueous solution (Isoton aqueous solution) and dispersed by ultrasonic waves for 30 seconds or more.

  The volume average particle size distribution index GSDv of the electrostatic image developing toner according to this embodiment is 1.27 or less, preferably 1.25 or less. When GSDv exceeds 1.27, the particle size distribution is not sharp, resolution is deteriorated, and image defects such as toner scattering and fogging are caused.

The volume average particle diameter D50v and the volume average particle size distribution index GSDv can be obtained as follows. For example, for the particle size range (channel) divided based on the particle size distribution of toner measured by a measuring instrument such as Coulter Counter TAII (Beckman-Coulter) or Multisizer II (Beckman-Coulter) Draw cumulative distributions from the small diameter side for each volume and number, the particle size to be accumulated 16% is the volume D16v, the number D16p, the particle size to be accumulated 50% is the volume D50v, the number D50p, the particle size to be accumulated 84% It is defined as a volume D84v and a number D84p. At this time, D50v represents the volume average particle diameter, and the volume average particle size distribution index (GSDv) is determined as (D84v / D16v) ^1/2 . In addition, (D84p / D16p) ^1/2 represents a number average particle size distribution index (GSDp).

In addition, the shape factor SF1 represented by the following formula of the toner for developing an electrostatic charge image according to the exemplary embodiment is in the range of 110 to 140, and preferably in the range of 115 to 130.
SF1 = (ML ² / A) × (π / 4) × 100
[In the above formula, ML represents the maximum toner length (μm), and A represents the projected area (μm ² ) of the toner. ]
When the toner shape factor SF1 is smaller than 110 or exceeds 140, it is impossible to obtain excellent chargeability, cleaning property, and transferability over a long period of time.

In addition, shape factor SF1 was measured as follows using a Luzex image analyzer (manufactured by Nireco Corporation, FT). First, an optical microscope image of the toner dispersed on the slide glass is taken into a Luzex image analyzer through a video camera, and the maximum length (ML) and projected area (A) of 50 or more toners are measured. (ML ² / A) × (π / 4) was calculated, and the average value was calculated as the shape factor SF1.

<Electrostatic image developer>
The toner for developing an electrostatic charge image according to the exemplary embodiment is used as it is as a one-component developer or as a two-component developer. When used as a two-component developer, it is used by mixing with a carrier.

  There is no restriction | limiting in particular as a carrier which can be used for a two-component developer, A well-known carrier can be used. Examples thereof include magnetic metals such as iron oxide, nickel and cobalt, magnetic oxides such as ferrite and magnetite, resin-coated carriers having a resin coating layer on the surface of the core material, and magnetic dispersion carriers. Further, a resin-dispersed carrier in which a conductive material or the like is dispersed in a matrix resin may be used.

  Coating resins and matrix resins used for carriers include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic. Examples thereof include, but are not limited to, acid copolymers, straight silicone resins composed of organosiloxane bonds or modified products thereof, fluororesins, polyesters, polycarbonates, phenol resins, epoxy resins and the like.

  Examples of the conductive material include metals such as gold, silver and copper, carbon black, titanium oxide, zinc oxide, barium sulfate, aluminum borate, potassium titanate, tin oxide, and carbon black. It is not limited.

  Examples of the core material of the carrier include magnetic metals such as iron, nickel, and cobalt, magnetic oxides such as ferrite and magnetite, and glass beads. However, in order to use the carrier for the magnetic brush method, it is a magnetic material. It is preferable. The volume average particle size of the core material of the carrier is generally in the range of 10 μm to 500 μm, and preferably in the range of 30 μm to 100 μm.

  In order to coat the surface of the core material of the carrier with a resin, there may be mentioned a method of coating with a coating layer forming solution in which the coating resin and, if necessary, various additives are dissolved in an appropriate solvent. The solvent is not particularly limited and may be appropriately selected in consideration of the coating resin to be used, coating suitability, and the like.

  Specific resin coating methods include an immersion method in which the carrier core material is immersed in the coating layer forming solution, a spray method in which the coating layer forming solution is sprayed onto the surface of the carrier core material, and the carrier core material is fluidized air. And a kneader coater method in which the carrier core material and the coating layer forming solution are mixed in a kneader coater and the solvent is removed in a kneader coater.

  The mixing ratio (weight ratio) of the toner according to the exemplary embodiment and the carrier in the two-component developer is in the range of toner: carrier = 1: 100 to 30: 100, and 3: 100 to 20: 100. A range of the degree is more preferable.

<Image forming method>
The image forming method according to the present embodiment uses a latent image forming step of forming an electrostatic latent image on the surface of the latent image carrier and a developer carried on the developer carrier, and is formed on the surface of the latent image carrier. A development 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 a toner transferred to the surface of the transfer target In the image forming method including the fixing step of fixing the image, the electrostatic image developer containing the electrostatic image developing toner of the present embodiment is used 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 according to the present embodiment may include steps other than the steps described above.

  As the latent image holding member, for example, an electrophotographic photosensitive member and a dielectric recording member can be used. In the case of an electrophotographic photosensitive member, the surface of the electrophotographic photosensitive member 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 particles are attached to the electrostatic latent image by contacting or approaching a developing roll having a developer layer formed on the surface, thereby forming a toner image on the electrophotographic photosensitive member (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 machine (fixing step) to form a final toner image.

  In the case of heat fixing by a fixing device, a release agent is usually supplied to a fixing member in the fixing device in order to prevent offset and the like.

The release agent is preferably not used from the viewpoint of eliminating the adhesion of oil to the transfer target and image after fixing. However, when the supply amount of the release agent is 0 mg / cm ² , the fixing member and the paper are fixed during fixing. The amount of wear of the fixing member increases and the durability of the fixing member may decrease when it comes into contact with a transfer medium such as the like. If necessary, the amount of release agent used is 8.0. It is preferable that a small amount is supplied to the fixing member in a range of × 10 ⁻³ mg / cm ² or less.

When the supply amount of the release agent exceeds 8.0 × 10 ⁻³ mg / cm ² , the image quality deteriorates due to the release agent adhering to the image surface after fixing, and in particular, transmitted light such as OHP is used. In such a case, such a phenomenon may appear remarkably. Further, the adhesion of the release agent to the transfer target becomes remarkable, and stickiness may occur. Further, the larger the supply amount of the release agent, the larger the capacity of the tank for storing the release agent, which causes an increase in the size of the fixing device itself.

  Although there is no restriction | limiting in particular as a mold release agent, For example, liquid mold release agents, such as modified oils, such as a dimethyl silicone oil, a fluorine oil, a fluoro silicone oil, and an amino modified silicone oil, are mentioned. Among these, modified oils such as amino-modified silicone oils are preferable because they are adsorbed on the surface of the fixing member and can form a uniform release agent layer, because they have excellent wettability to the fixing member. Further, from the viewpoint of forming a homogeneous release agent layer, fluorine oil and fluorosilicone oil are preferable.

  Fluorine oil or fluorosilicone oil is used as the release agent in the conventional image forming method that does not use the electrostatic image developing toner according to this embodiment, and the supply amount of the release agent itself can be reduced. However, in the case of using the electrostatic image developing toner according to the present embodiment, since the supply amount of the release agent can be drastically reduced, there is no practical problem in terms of cost.

  The method for supplying the release agent to the surface of the roller or belt that is a fixing member used for the heat fixing is not particularly limited. For example, a pad method using a pad impregnated with a liquid release agent, a web method, a roller Examples thereof include a non-contact type shower method (spray method), and a web method and a roller method are particularly preferable. These methods are advantageous in that the release agent can be supplied uniformly and the supply amount can be easily controlled. In order to supply the release agent uniformly to the entire fixing member by the shower method, it is necessary to use a separate blade or the like.

  The supply amount of the release agent can be measured as follows. That is, when a normal paper (typically, a copy paper manufactured by Fuji Xerox Co., Ltd., trade name J paper) used in a general copying machine is passed through a fixing member supplied with a release agent on its surface. The release agent adheres to the plain paper. Then, the attached release agent is extracted using a Soxhlet extractor. Here, hexane is used as the solvent.

  By quantifying the amount of the release agent contained in hexane with an atomic absorption analyzer, the amount of the release agent adhering to the plain paper can be quantified. This amount is defined as the amount of release agent supplied to the fixing member.

  Examples of the transfer target (recording material) to which the toner image is transferred include plain paper, OHP sheet, and the like used for 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.

  Since the image forming method according to the present embodiment uses the electrostatic charge image developer (the toner according to the present embodiment), it is possible to achieve both heat storage and low-temperature fixability, and sufficient filming resistance. Therefore, image defects do not occur. Further, since the amorphous resin fine particles having a small particle diameter are used for the shell layer, the gloss of the fixed image is good.

  Hereinafter, although an example and a comparative example are given and the present invention is explained more concretely in detail, the present invention is not limited to the following examples.

<Preparation of crystalline polyester resin dispersion 1>
A heat-dried three-necked flask was charged with 250 parts by weight of ethylene glycol, 46 parts by weight of sodium dimethyl 5-sulfoisophthalate, 430 parts by weight of dimethyl sebacate, and 0.6 parts by weight of dibutyltin oxide as a catalyst. The inside air was brought into an inert atmosphere with nitrogen gas, and stirred at 175 ° C. for 6 hours by mechanical stirring. Thereafter, the temperature was gradually raised to 210 ° C. under reduced pressure, and the mixture was stirred for 2.5 hours. When the viscosity increased, the mixture was cooled with air, the reaction was stopped, and a crystalline polyester resin (1) was synthesized.

  The molecular weight measurement (polystyrene conversion) by gel permeation chromatography (GPC) revealed that the crystalline polyester resin (1) obtained had a weight average molecular weight (Mw) of 26800 and a number average molecular weight (Mn) of 8800. In addition, the melting point (Tm) of the crystalline polyester resin (1) is measured by the above-described measuring method using a differential scanning calorimeter (device name: DSC-60 type) manufactured by Shimadzu Corporation equipped with an automatic tangential processing system. When measured at a rate of temperature increase of 10 ° C./min, it had a clear peak (the temperature from the onset point to the peak top of the endothermic peak was 3.2 ° C.), and the peak top temperature was 67 ° C.

  Next, 200 parts by weight of the crystalline polyester and 1800 parts by weight of deionized water are placed in a stainless beaker, placed in a warm bath, and heated to 95 ° C. When the crystalline polyester resin was melted, the mixture was stirred at 8000 rpm using a homogenizer (manufactured by IKA: Ultra Turrax T50). Next, an emulsion was dispersed while adding 45 parts by weight of an aqueous solution obtained by diluting 2.8 parts by weight of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK), and crystals having a volume average particle diameter of 0.20 μm. -Soluble polyester resin dispersion 1 (resin particle concentration: 11% by weight) was prepared. The volume average particle size was measured by a laser scattering diffraction particle size distribution analyzer LS13-1320 manufactured by Beckman Coulter.

<Preparation of amorphous resin fine particle dispersion 1>
In a heat-dried two-necked flask, 35 mol parts of polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane and polyoxypropylene (2,2) -2,2-bis (4 -Hydroxyphenyl) propane 70 mol part, terephthalic acid 85 mol part, n-dodecenyl succinic acid 12 mol part, trimellitic acid 11 mol part, and these acid components (terephthalic acid, n-dodecenyl succinic acid, trimellitic acid 0.05 mol part of dibutyltin oxide with respect to the total number of moles), nitrogen gas was introduced into the container and the temperature was maintained in an inert atmosphere, and then heated at 150 to 230 ° C. for about 12 hours. A polycondensation reaction was performed, and then the pressure was gradually reduced at 210 to 250 ° C. to synthesize an amorphous polyester resin (1). The weight average molecular weight (Mw) of the obtained amorphous polyester resin (1) was 17200 and the number average molecular weight (Mn) was 7200 by molecular weight measurement (polystyrene conversion) by gel permeation chromatography. Further, when the DSC spectrum of the amorphous polyester resin (1) was measured using a differential scanning calorimeter (DSC) in the same manner as the measurement of the melting point described above, no clear peak was shown (from the onset point). The temperature up to the peak top of the endothermic peak was 24 ° C.), and a stepwise endothermic change was observed. The glass transition temperature at the midpoint of the stepwise endothermic change was 66 ° C.

  Next, 160 parts by weight of this amorphous polyester resin (1) and 1440 parts by weight of deionized water are placed in a stainless beaker, placed in a warm bath, and heated to 90 ° C. When the amorphous polyester resin melted, the mixture was stirred at 8000 rpm using a homogenizer (manufactured by IKA: Ultra Tarrax T50). Then, an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK) was emulsified and dispersed while dropping 40 parts by weight of an aqueous solution diluted with 3.9 parts by weight, and the volume average particle size was 0.18 μm. Crystalline resin dispersion 1 [resin particle concentration: 10% by weight] was prepared.

<Preparation of amorphous resin fine particle dispersion 2>
1,5-naphthalenedicarboxylic acid methyl ester 180 parts by weight, dimethyl terephthalate 120 parts by weight, dimethyl isophthalate 120 parts by weight, cyclohexanedimethanol 150 parts by weight, ethylene glycol 200 parts by weight, tetrabutoxy titanate 0.1 parts by weight The mixture was heated for 3 hours for transesterification. Next, after the temperature was raised to 250 ° C., the reaction was continued for 1 hour at a reaction system pressure of 20 mmHg to obtain a copolymerized polyester resin having a weight average molecular weight (Mw) of 10200 and a number average molecular weight (Mn) of 3800. When the DSC spectrum of this amorphous resin was measured using a differential scanning calorimeter (DSC) in the same manner as the above-mentioned melting point measurement, no clear peak was shown (the peak top of the endothermic peak from the onset point). Up to 23 ° C.), a step-like endothermic change was observed. The glass transition temperature at the midpoint of the stepwise endothermic change was 88 ° C. The polyester was dissolved in a mixed solvent of methyl ethyl ketone and tetrahydrofuran, and then ion-exchanged water was added to obtain an aqueous micro dispersion having a volume average particle size of 50 nm. Further, the obtained dispersion was put into a distillation flask and distilled until the fraction temperature was 100 ° C. After cooling, ion exchange water was added to obtain a solid concentration of 25%.

<Preparation of amorphous resin fine particle dispersion 3>
380 parts by weight of styrene, 179 parts by weight of n-butyl acrylate, 4 parts by weight of acrylic acid, 24 parts by weight of dodecanethiol, and 4 parts by weight of carbon tetrabromide were mixed and dissolved in a nonionic surfactant (Sanyo Kasei). Co., Ltd .: Nonipol 400) 6 parts by weight and anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 20 parts by weight dissolved in ion-exchanged water 990 parts by weight were dispersed in a flask. After emulsifying and slowly mixing for 10 minutes, 50 parts by weight of ion-exchanged water in which 4 parts by weight of ammonium persulfate was dissolved was added thereto, and after nitrogen substitution, the contents were stirred while stirring the inside of the flask. The mixture was heated in an oil bath until it reached 70 ° C., and emulsion polymerization was continued for 5 hours. Thus, an amorphous resin dispersion 3 (resin particle concentration: 40% by weight) obtained by dispersing resin particles having a volume average particle size of 95 nm and a weight average molecular weight (Mw) of 29900 was prepared. When the DSC spectrum of this amorphous resin was measured using a differential scanning calorimeter (DSC) in the same manner as the above-mentioned melting point measurement, no clear peak was shown (the peak top of the endothermic peak from the onset point). Up to 14 ° C.), a step-like change in endothermic amount was observed. The glass transition temperature at the midpoint of the stepwise endothermic change was 38 ° C.

<Preparation of amorphous resin fine particle dispersion 4>
1,5-naphthalenedicarboxylic acid methyl ester 180 parts by weight, dimethyl terephthalate 120 parts by weight, dimethyl isophthalate 120 parts by weight, cyclohexanedimethanol 150 parts by weight, ethylene glycol 200 parts by weight, tetrabutoxy titanate 0.1 parts by weight In the same manner as in the preparation of the amorphous resin fine particle dispersion 2, a copolymerized polyester resin having a weight average molecular weight (Mw) of 10200 and a number average molecular weight (Mn) of 3800 is obtained. An amorphous resin fine particle dispersion 4 was obtained. When the DSC spectrum of this amorphous resin was measured using a differential scanning calorimeter (DSC) in the same manner as the above-mentioned melting point measurement, no clear peak was shown (the peak top of the endothermic peak from the onset point). Up to 30 ° C.), a step-like change in endothermic amount was observed. The glass transition temperature at the midpoint of the stepwise endothermic change was 65 ° C. The volume average particle diameter of the amorphous resin fine particles was 50 nm.

<Preparation of amorphous resin fine particle dispersion 5>
1,5-naphthalenedicarboxylic acid methyl ester 180 parts by weight, dimethyl terephthalate 120 parts by weight, dimethyl isophthalate 120 parts by weight, cyclohexanedimethanol 150 parts by weight, ethylene glycol 200 parts by weight, tetrabutoxy titanate 0.1 parts by weight In the same manner as in the preparation of the amorphous resin fine particle dispersion 2, a copolymerized polyester resin having a weight average molecular weight (Mw) of 10200 and a number average molecular weight (Mn) of 3800 is obtained. Amorphous resin fine particle dispersion 5 containing was obtained. When the DSC spectrum of this amorphous resin was measured using a differential scanning calorimeter (DSC) in the same manner as the above-mentioned melting point measurement, no clear peak was shown (the peak top of the endothermic peak from the onset point). Up to 26 ° C.), a step-like change in endothermic amount was observed. The glass transition temperature at the midpoint of the stepwise endothermic change was 150 ° C. The volume average particle diameter of the amorphous resin fine particles was 50 nm.

<Preparation of amorphous resin fine particle dispersion 6>
1,5-naphthalenedicarboxylic acid methyl ester 180 parts by weight, dimethyl terephthalate 120 parts by weight, dimethyl isophthalate 120 parts by weight, cyclohexanedimethanol 150 parts by weight, ethylene glycol 200 parts by weight, tetrabutoxy titanate 0.1 parts by weight In the same manner as in the preparation of the amorphous resin fine particle dispersion 2, a copolymerized polyester resin having a weight average molecular weight (Mw) of 10200 and a number average molecular weight (Mn) of 3800 is obtained. Amorphous resin fine particle dispersion 6 containing was obtained. When the DSC spectrum of this amorphous resin was measured using a differential scanning calorimeter (DSC) in the same manner as the above-mentioned melting point measurement, no clear peak was shown (the peak top of the endothermic peak from the onset point). Up to 24 ° C.), a step-like endothermic change was observed. The glass transition temperature at the midpoint of the stepwise endothermic change was 200 ° C. The volume average particle diameter of the amorphous resin fine particles was 50 nm.

<Preparation of amorphous resin fine particle dispersion 7>
1,5-naphthalenedicarboxylic acid methyl ester 180 parts by weight, dimethyl terephthalate 120 parts by weight, dimethyl isophthalate 120 parts by weight, cyclohexanedimethanol 150 parts by weight, ethylene glycol 200 parts by weight, tetrabutoxy titanate 0.1 parts by weight In the same manner as in the preparation of the amorphous resin fine particle dispersion 2, a copolymerized polyester resin having a weight average molecular weight (Mw) of 10200 and a number average molecular weight (Mn) of 3800 is obtained. Amorphous resin fine particle dispersion 7 containing was obtained. When the DSC spectrum of this amorphous resin was measured using a differential scanning calorimeter (DSC) in the same manner as the above-mentioned melting point measurement, no clear peak was shown (the peak top of the endothermic peak from the onset point). Up to 26 ° C.), a step-like change in endothermic amount was observed. The glass transition temperature at the midpoint of the stepwise endothermic change was 300 ° C. The volume average particle diameter of the amorphous resin fine particles was 50 nm.

<Preparation of amorphous resin fine particle dispersion 8>
1,5-naphthalenedicarboxylic acid methyl ester 180 parts by weight, dimethyl terephthalate 120 parts by weight, dimethyl isophthalate 120 parts by weight, cyclohexanedimethanol 150 parts by weight, ethylene glycol 200 parts by weight, tetrabutoxy titanate 0.1 parts by weight In the same manner as in the preparation of the amorphous resin fine particle dispersion 2, a copolymerized polyester resin having a weight average molecular weight (Mw) of 10200 and a number average molecular weight (Mn) of 3800 is obtained. Amorphous resin fine particle dispersion 8 containing was obtained. When the DSC spectrum of this amorphous resin was measured using a differential scanning calorimeter (DSC) in the same manner as the above-mentioned melting point measurement, no clear peak was shown (the peak top of the endothermic peak from the onset point). Up to 20 ° C.), a step-like endothermic change was observed. The glass transition temperature at the midpoint of the stepwise endothermic change was 88 ° C. The volume average particle diameter of the amorphous resin fine particles was 20 nm.

<Preparation of amorphous resin fine particle dispersion 9>
1,5-naphthalenedicarboxylic acid methyl ester 180 parts by weight, dimethyl terephthalate 120 parts by weight, dimethyl isophthalate 120 parts by weight, cyclohexanedimethanol 150 parts by weight, ethylene glycol 200 parts by weight, tetrabutoxy titanate 0.1 parts by weight In the same manner as in the preparation of the amorphous resin fine particle dispersion 2, a copolymerized polyester resin having a weight average molecular weight (Mw) of 10200 and a number average molecular weight (Mn) of 3800 is obtained. An amorphous resin fine particle dispersion 9 was obtained. When the DSC spectrum of this amorphous resin was measured using a differential scanning calorimeter (DSC) in the same manner as the above-mentioned melting point measurement, no clear peak was shown (the peak top of the endothermic peak from the onset point). Up to 28 ° C.), a step-like change in endothermic amount was observed. The glass transition temperature at the midpoint of the stepwise endothermic change was 88 ° C. The volume average particle diameter of the amorphous resin fine particles was 200 nm.

<Preparation of amorphous resin fine particle dispersion 10>
1,5-naphthalenedicarboxylic acid methyl ester 180 parts by weight, dimethyl terephthalate 120 parts by weight, dimethyl isophthalate 120 parts by weight, cyclohexanedimethanol 150 parts by weight, ethylene glycol 200 parts by weight, tetrabutoxy titanate 0.1 parts by weight In the same manner as in the preparation of the amorphous resin fine particle dispersion 2, a copolymerized polyester resin having a weight average molecular weight (Mw) of 10200 and a number average molecular weight (Mn) of 3800 is obtained. Amorphous resin fine particle dispersion 10 containing was obtained. When the DSC spectrum of this amorphous resin was measured using a differential scanning calorimeter (DSC) in the same manner as the above-mentioned melting point measurement, no clear peak was shown (the peak top of the endothermic peak from the onset point). Up to 19 ° C.), a step-like change in endothermic amount was observed. The glass transition temperature at the midpoint of the stepwise endothermic change was 88 ° C. The volume average particle diameter of the amorphous resin fine particles was 500 nm.

<Preparation of Amorphous Resin Fine Particle Dispersion 11>
1,5-naphthalenedicarboxylic acid methyl ester 180 parts by weight, dimethyl terephthalate 120 parts by weight, dimethyl isophthalate 120 parts by weight, cyclohexanedimethanol 150 parts by weight, ethylene glycol 200 parts by weight, tetrabutoxy titanate 0.1 parts by weight In the same manner as in the preparation of the amorphous resin fine particle dispersion 2, a copolymerized polyester resin having a weight average molecular weight (Mw) of 10200 and a number average molecular weight (Mn) of 3800 is obtained. An amorphous resin fine particle dispersion 11 was obtained. When the DSC spectrum of this amorphous resin was measured using a differential scanning calorimeter (DSC) in the same manner as the above-mentioned melting point measurement, no clear peak was shown (the peak top of the endothermic peak from the onset point). Up to 24 ° C.), a step-like endothermic change was observed. The glass transition temperature at the midpoint of the stepwise endothermic change was 88 ° C. The volume average particle diameter of the amorphous resin fine particles was 800 nm.

<Preparation of Amorphous Resin Fine Particle Dispersion 12>
1,5-naphthalenedicarboxylic acid methyl ester 180 parts by weight, dimethyl terephthalate 120 parts by weight, dimethyl isophthalate 120 parts by weight, cyclohexanedimethanol 150 parts by weight, ethylene glycol 200 parts by weight, tetrabutoxy titanate 0.1 parts by weight In the same manner as in the preparation of the amorphous resin fine particle dispersion 2, a copolymerized polyester resin having a weight average molecular weight (Mw) of 10200 and a number average molecular weight (Mn) of 3800 is obtained. Amorphous resin fine particle dispersion 12 containing was obtained. When the DSC spectrum of this amorphous resin was measured using a differential scanning calorimeter (DSC) in the same manner as the above-mentioned melting point measurement, no clear peak was shown (the peak top of the endothermic peak from the onset point). Up to 17 ° C.), a step-like change in endothermic amount was observed. The glass transition temperature at the midpoint of the stepwise endothermic change was 60 ° C. The volume average particle diameter of the amorphous resin fine particles was 50 nm.

<Preparation of Amorphous Resin Fine Particle Dispersion 13>
1,5-naphthalenedicarboxylic acid methyl ester 180 parts by weight, dimethyl terephthalate 120 parts by weight, dimethyl isophthalate 120 parts by weight, cyclohexanedimethanol 150 parts by weight, ethylene glycol 200 parts by weight, tetrabutoxy titanate 0.1 parts by weight In the same manner as in the preparation of the amorphous resin fine particle dispersion 2, a copolymerized polyester resin having a weight average molecular weight (Mw) of 10200 and a number average molecular weight (Mn) of 3800 is obtained. Amorphous resin fine particle dispersion 7 containing was obtained. When the DSC spectrum of this amorphous resin was measured using a differential scanning calorimeter (DSC) in the same manner as the above-mentioned melting point measurement, no clear peak was shown (the peak top of the endothermic peak from the onset point). Up to 22 ° C.), a step-like endothermic change was observed. The glass transition temperature at the midpoint of the stepwise endothermic change was 88 ° C. The volume average particle diameter of the amorphous resin fine particles was 15 nm.

<Preparation of amorphous resin fine particle dispersion 14>
1,5-naphthalenedicarboxylic acid methyl ester 180 parts by weight, dimethyl terephthalate 120 parts by weight, dimethyl isophthalate 120 parts by weight, cyclohexanedimethanol 150 parts by weight, ethylene glycol 200 parts by weight, tetrabutoxy titanate 0.1 parts by weight In the same manner as in the preparation of the amorphous resin fine particle dispersion 2, a copolymerized polyester resin having a weight average molecular weight (Mw) of 10200 and a number average molecular weight (Mn) of 3800 is obtained. Amorphous resin fine particle dispersion 7 containing was obtained. When the DSC spectrum of this amorphous resin was measured using a differential scanning calorimeter (DSC) in the same manner as the above-mentioned melting point measurement, no clear peak was shown (the peak top of the endothermic peak from the onset point). Up to 18 ° C.), a step-like change in endothermic amount was observed. The glass transition temperature at the midpoint of the stepwise endothermic change was 88 ° C. The volume average particle diameter of the amorphous resin fine particles was 820 nm.

<Production of Amorphous Crosslinked Fine Particle Dispersion 1>
In a reaction vessel equipped with a stirrer having a plurality of stirring blades, a reflux condenser, a thermometer, and a nitrogen introduction tube, 920 parts by weight of ion-exchanged water was added, and the inside of the reaction vessel was sufficiently substituted with nitrogen. In a reaction vessel, add 16 parts by weight of sodium dodecylbenzenesulfonate, 70 parts by weight of styrene monomer, 15 parts by weight of acrylic acid monomer, and 20 parts by weight of divinylbenzene monomer, and 1.5 parts by weight of sodium persulfate. The mixture was sufficiently stirred to obtain a mixed solution. The mixed solution was stirred and reacted at about 80 ° C. for about 5 hours while stirring at about 250 rpm. After the stirring reaction, the mixed solution is cooled and filtered by suction using a filter having a pore size of 8 μm, 2 μm, 1 μm, 0.8 μm, 0.6 μm, 0.45 μm, 0.2 μm, 0.1 μm in order to obtain a coarse powder. Removed. The filtrate is ultrafiltered with about 50 liters of ion exchange water using an ultrafiltration device (manufactured by NGK) equipped with a ceramic filter, and finally the solid content concentration is adjusted to 25% by weight. Thus, an amorphous crosslinked fine particle dispersion 1 was obtained. The obtained amorphous crosslinked fine particles were almost spherical particles, and the average particle size was about 78 nm. The average particle size of the particles is determined by observing and photographing a dried particle obtained by freeze-drying a part of the dispersion with a transmission electron microscope (TEM), and measuring an arbitrary 500 particle size from the photograph. And it is the value obtained by taking the average value. Further, when the DSC spectrum of the amorphous crosslinked fine particles 1 was measured using a differential scanning calorimeter (DSC) in the same manner as the above-mentioned melting point measurement, no clear peak was shown, and the stepwise endothermic change Was also not observed.

<Production of Amorphous Crosslinked Fine Particle Dispersion 2>
In a reaction vessel equipped with a stirrer having a plurality of stirring blades, a reflux condenser, a thermometer, and a nitrogen introduction tube, 920 parts by weight of ion-exchanged water was added, and the inside of the reaction vessel was sufficiently substituted with nitrogen. In a reaction vessel, add 13 parts by weight of sodium dodecylbenzenesulfonate, 102 parts by weight of styrene monomer, 18 parts by weight of acrylic acid monomer, and 20 parts by weight of divinylbenzene monomer, and 1.5 parts by weight of sodium persulfate. The mixture was sufficiently stirred to obtain a mixed solution. The mixed solution was stirred and reacted at about 80 ° C. for about 5 hours while stirring at about 250 rpm. After the stirring reaction, the mixed solution is cooled and filtered by suction using a filter having a pore size of 8 μm, 2 μm, 1 μm, 0.8 μm, 0.6 μm, 0.45 μm, 0.2 μm, 0.1 μm in order to obtain a coarse powder. Removed. The filtrate is ultrafiltered with about 50 liters of ion exchange water using an ultrafiltration device (manufactured by NGK) equipped with a ceramic filter, and finally the solid content concentration is adjusted to 25% by weight. Thus, an amorphous crosslinked fine particle dispersion 1 was obtained. The obtained amorphous crosslinked fine particles were almost spherical particles, and the average particle size was about 78 nm. The average particle size of the particles is determined by observing and photographing a dried particle obtained by freeze-drying a part of the dispersion with a transmission electron microscope (TEM), and measuring an arbitrary 500 particle size from the photograph. And it is the value obtained by taking the average value. Further, when the DSC spectrum of the amorphous crosslinked fine particles 2 was measured using a differential scanning calorimeter (DSC) in the same manner as the above-mentioned melting point measurement, no clear peak was shown, and the stepwise endothermic change Was also not observed.

<Preparation of mold release agent dispersion 1>
100 parts by weight of ester wax (Nippon Yushi Co., Ltd .: WE-2, melting point 65 ° C.), 12 parts by weight of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK), 200 parts by weight of ion-exchanged water The mixture was heated to 95 ° C. and dispersed using a homogenizer (manufactured by IKA: Ultra Turrax T50), and then dispersed with a Menton Gorin high-pressure homogenizer (Gorin) to obtain a release agent having a volume average particle diameter of 210 nm. A release agent dispersion liquid (release agent concentration: 23% by weight) was prepared.

<Preparation of Colorant Dispersion 1>
1,500 parts by weight of a cyan pigment (manufactured by Dainichi Seika Co., Ltd., Pigment Blue 15: 3 (copper phthalocyanine)), 270 parts by weight of an anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: Neogen R), 8600 parts by weight of ion-exchanged water Is mixed and dissolved, and a colorant dispersion is prepared by dispersing the colorant (cyan pigment) by dispersing for about 2 hours using a high-pressure impact disperser ULTIMIZER (manufactured by Sugino Machine Co., Ltd., HJP30006). did. The volume average particle size of the colorant (cyan pigment) in the colorant dispersion was 0.19 μm, and the colorant particle concentration was 22% by weight.

<Manufacture of core particle 1>
Crystalline polyester resin dispersion 1: 2727 parts by weight Release agent dispersion 1: 180 parts by weight Colorant dispersion 1: 72 parts by weight Calcium polysulfide: 1.44 parts by weight Calcium chloride: 0.92 parts by weight After being accommodated in a stainless steel flask and adjusted to pH 4.5, a homogenizer (manufactured by IKA: Ultra Tarrax T50) was dispersed, and then heated to 55 ° C. with stirring in an oil bath for heating. After maintaining at 55 ° C. for 2.5 hours, observation with an optical microscope confirmed that aggregated particles having a volume average particle diameter of about 5.1 μm were formed. Furthermore, after maintaining heating and stirring at 63 ° C. for 1 hour, it was confirmed that aggregated particles having a volume average particle diameter of 6.0 μm were formed by observation with an optical microscope.

  The pH of this aggregated particle dispersion was 4.6. Therefore, an aqueous solution obtained by diluting sodium hydroxide (manufactured by Wako Pure Chemical Industries, Ltd.) to 0.5 mol / L was gently added to adjust the pH to 7.5. The aggregated particle dispersion was heated to 85 ° C. while being continuously stirred and held for 60 minutes, and then observed with an optical microscope, and coalesced spherical particles were observed. Thereafter, the temperature was lowered to 25 ° C. at a rate of 1 ° C./min while adding ion-exchanged water to obtain core particles 1. The dispersion of the core particles 1 was subjected to solid-liquid separation by Nutsche suction filtration using a No5A filter paper to obtain a wet cake of the core particles 1 having a solid content concentration of 45%.

  Further, when the particle size distribution of the core particle 1 was measured using a Coulter counter [TA-II] type (aperture diameter: 50 μm, manufactured by Coulter, Inc.), the volume average particle diameter was 6.0 μm.

<Manufacture of core particle 2>
Crystalline polyester resin dispersion 1: 700 parts by weight Amorphous resin fine particle dispersion 1: 2400 parts by weight Release agent dispersion 1: 180 parts by weight Colorant dispersion 1: 65.22 parts by weight Polyaluminum chloride: 1. 44 parts by weight Calcium chloride: 0.92 parts by weight The above is placed in a round stainless steel flask and adjusted to pH 4.5, and then a homogenizer (IKA: Ultra Turrax T50) is dispersed and heated. Heated to 62 ° C. in an oil bath with stirring. After maintaining at 62 ° C. for 3 hours and observing with an optical microscope, it was confirmed that aggregated particles having a volume average particle diameter of about 5.2 μm were formed. Further, after maintaining heating and stirring at 62 ° C. for 1 hour, it was confirmed by observation with an optical microscope that aggregated particles having a volume average particle diameter of 6.2 μm were formed.

  The pH of this aggregated particle dispersion was 4.8. Accordingly, an aqueous solution obtained by diluting sodium hydroxide (manufactured by Wako Pure Chemical Industries, Ltd.) to 0.5 mol / L was gently added to adjust the pH to 8.0. The aggregated particle dispersion was heated to 95 ° C. while being stirred and held for 30 minutes, and then observed with an optical microscope, and coalesced spherical particles were observed. Thereafter, the temperature was lowered to 25 ° C. at a rate of 1 ° C./min while adding ion-exchanged water to obtain core particles 2.

  After completion of the particle size measurement, the obtained dispersion of the core particles 2 was subjected to solid-liquid separation by Nutsche suction filtration using No5A filter paper to obtain a wet cake of the core particles 2 having a solid content concentration of 53%. .

  Moreover, when the particle size distribution of the core particle 2 was measured using a Coulter counter [TA-II] type (aperture diameter: 50 μm, manufactured by Coulter, Inc.), the volume average particle diameter was 6.2 μm.

<Manufacture of core particle 3>
Amorphous resin fine particle dispersion 3: 800 parts by weight Release agent dispersion 1: 180 parts by weight Colorant dispersion 1: 98.2 parts by weight Polyaluminum chloride: 1.86 parts by weight Ion exchange water: 2100 parts by weight or more Were thoroughly mixed and dispersed with Ultra Turrax T50 in a round stainless steel flask. Dispersion operation was continued with Ultra Talux. The flask was heated to 47 ° C. with stirring in an oil bath for heating. After maintaining at 47 ° C. for 60 minutes, 31 parts by weight of the resin dispersion was gradually added thereto. Thereafter, the pH of the system was adjusted to 6.0 with a 0.5 mol / L sodium hydroxide aqueous solution, and then the stainless steel flask was sealed and heated to 75 ° C. while continuing to stir using a magnetic seal for 5 hours. By holding, core particles 3 were obtained. After completion of the reaction, the obtained dispersion of core particles 3 was subjected to solid-liquid separation by Nutsche suction filtration using No5A filter paper to obtain a wet cake of core particles 3 having a solid content concentration of 66%.

  Further, when the particle size distribution of the core particles 3 was measured using a Coulter counter [TA-II] type (aperture diameter: 50 μm, manufactured by Coulter, Inc.), the volume average particle diameter was 5.8 μm.

<Manufacture of toner 1>
After 356 parts by weight of the wet cake of the core particles 1 was put in a 3 L flask, 102 parts by weight of the amorphous resin fine particle dispersion 2 was added, and stirring was started. Ten minutes later, 72.3 parts by weight of ion-exchanged water was added, and then the pH was measured and found to be 4.9. Thereafter, the pH was adjusted to 3.0 by gradually adding a 0.3 mol / L nitric acid aqueous solution. 30 minutes later, 0.14 parts by weight of polyaluminum chloride was added, and 30 minutes later, the temperature was raised to 48 ° C. at a rate of 0.5 ° C./1 minute. After 2 hours at 48 ° C, the temperature was raised to 53 ° C at a rate of 0.1 ° C / 1 minute. Since the pH at this time was 7.3, it was adjusted to pH 7.5 by gradually adding a 0.5 mol / L aqueous sodium hydroxide solution, and heating was continued for 4 hours. After 4 hours, it was confirmed by electron microscope (SEM) photography that a shell layer of adhering fine particles was formed on the surface of the core particles, and then the temperature was lowered to 25 ° C. in 30 minutes. After cooling, the volume average particle diameter was 6.2 μm as measured using a Coulter Counter [TA-II] type (aperture diameter: 50 μm, manufactured by Coulter). Thereafter, the reaction product was washed and then dried by a freeze dryer to obtain toner 1.

  Using a transmission electron microscope (STEM, Hitachi S-4800 type), the cross section of the toner particle 1 was observed under the condition of an acceleration voltage of 30 kV. As a result, a shell layer was formed with a uniform film thickness of about 120 nm on the surface of the core particle. It has been confirmed. Further, when the surface of the toner particle 1 was observed by SEM under the condition of an acceleration voltage of 2 kV, it was found that the shell layer was not a complete continuous layer. Assuming that the specific gravity of the resin is 1.1 to 1.2, the content of the amorphous resin fine particles estimated from the film thickness of the shell layer is 15.3% with respect to the weight of the core particles, The value almost coincided with the theoretical value (16% by weight). The toner 1 also showed a clear peak around 67 ° C. (temperature from the onset point to the top of the endothermic peak is 4.5 ° C.) and a stepped peak around 88 ° C. (endothermic from the onset point). The temperature up to the peak top of the peak was 16 ° C.).

<Manufacture of toner 2>
Toner 2 was obtained by performing the same treatment as that for toner 1 except that 128 parts by weight of amorphous resin fine particle dispersion 2 was added. The volume average particle diameter was 6.2 μm.

<Manufacture of toner 3>
Toner 3 was obtained by performing the same treatment as in the production of toner 1 except that 302 parts by weight of the wet cake of core particles 2 was used. Further, the volume average particle size at this time was 6.4 μm.

<Manufacture of toner 4>
Except for using 159 parts by weight of the amorphous resin fine particle dispersion 2, the same procedure as in the production of the toner 3 was performed to obtain the toner 4. Further, the volume average particle size at this time was 6.4 μm.

<Manufacture of toner 5>
Toner 5 was obtained by carrying out the same treatment as that of toner 1 except that 242 parts by weight of the wet cake of core particle 3 was used. Further, the volume average particle diameter at this time was 6.0 μm.

<Manufacture of toner 6>
Except for using 140 parts by weight of the amorphous resin fine particle dispersion 2, the same treatment as in the production of the toner 5 was performed to obtain the toner 6. Further, the volume average particle diameter at this time was 6.0 μm.

<Manufacture of toner 7>
A toner 7 was obtained by carrying out the same treatment as in the production of the toner 1 except that 102 parts by weight of the amorphous resin fine particle dispersion 4 was added. The volume average particle diameter was 6.2 μm.

<Manufacture of toner 8>
A toner 8 was obtained by carrying out the same treatment as in the production of the toner 1 except that 102 parts by weight of the amorphous resin fine particle dispersion 5 was added. The volume average particle diameter was 6.2 μm.

<Manufacture of toner 9>
A toner 9 was obtained by carrying out the same treatment as in the production of the toner 1 except that 102 parts by weight of the amorphous resin fine particle dispersion 6 was added. The volume average particle size was 6.4 μm.

<Manufacture of Toner 10>
A toner 10 was obtained by carrying out the same treatment as in the production of the toner 1 except that 102 parts by weight of the amorphous resin fine particle dispersion 7 was added. The volume average particle size was 6.4 μm.

<Manufacture of toner 11>
A toner 11 was obtained by performing the same process as in the production of the toner 1 except that 102 parts by weight of the amorphous resin fine particle dispersion 8 was added. The volume average particle diameter was 6.3 μm.

<Manufacture of toner 12>
A toner 12 was obtained by carrying out the same treatment as in the production of the toner 1 except that 102 parts by weight of the amorphous resin fine particle dispersion 9 was added. The volume average particle diameter was 6.2 μm.

<Manufacture of toner 13>
A toner 13 was obtained by performing the same process as in the production of the toner 1 except that 102 parts by weight of the amorphous resin fine particle dispersion 10 was added. The volume average particle diameter was 6.2 μm.

<Manufacture of toner 14>
A toner 14 was obtained by carrying out the same treatment as in the production of the toner 1 except that 102 parts by weight of the amorphous resin fine particle dispersion 11 was added. The volume average particle size was 6.4 μm.

<Manufacture of toner 15>
A toner 14 was obtained by carrying out the same treatment as in the production of the toner 1 except that 31.9 parts by weight of the amorphous resin fine particle dispersion 2 was added. The volume average particle diameter was 6.0 μm.

<Manufacture of Toner 16>
After putting 333 parts by weight of the wet cake of the core particles 1 into a 3 L flask, 102 parts by weight of the amorphous crosslinked fine particle dispersion 1 was added, and stirring was started. Ten minutes later, 94 parts by weight of ion-exchanged water was added, and the pH was measured and found to be 5.3. Thereafter, the pH was adjusted to 3.0 by gradually adding a 0.3 mol / L nitric acid aqueous solution. After 30 minutes, 0.14 parts by weight of aluminum sulfate was added, and 30 minutes later, the temperature was raised to 48 ° C. at a rate of 0.5 ° C./1 minute. After 2 hours at 48 ° C, the temperature was raised to 53 ° C at a rate of 0.1 ° C / 1 minute. Since the pH at this time was 7.3, it was adjusted to pH 7.5 by gradually adding a 0.5 mol / L aqueous sodium hydroxide solution, and heating was continued for 4 hours. After 4 hours, it was confirmed by electron microscope (SEM) photography that a shell layer of adhering fine particles was formed on the surface of the core particles, and then the temperature was lowered to 25 ° C. in 30 minutes. After cooling, when measured using a Coulter Counter [TA-II] type (aperture diameter: 50 μm, manufactured by Coulter), the volume average particle diameter was 5.9 μm. Thereafter, the reaction product was washed and then dried by a freeze dryer to obtain toner 16.

<Manufacture of toner 17>
Except for adding 121 parts by weight of amorphous crosslinked fine particle dispersion 1, toner 17 was obtained by carrying out the same treatment as in the production of toner 16. The average particle size at this time was 5.9 μm.

<Manufacture of Toner 18>
Toner 18 was obtained in the same manner as in the production of toner 16, except that 308 parts by weight of wet cake of core particle 2 and 0.14 part by weight of polyaluminum chloride were used. The volume average particle size at this time was 5.7 μm.

<Manufacture of Toner 19>
Except for adding 140 parts by weight of the amorphous crosslinked fine particle dispersion 1, a toner 19 was obtained by carrying out the same treatment as in the production of the toner 18. The average particle size at this time was 5.7 μm.

<Manufacture of toner 20>
Toner 20 was obtained in the same manner as in the production of toner 16 except that 258 parts by weight of wet cake of core particle 3 and 0.14 part by weight of polyaluminum hydroxide were used. Further, the volume average particle diameter at this time was 6.0 μm.

<Manufacture of toner 21>
Except for adding 159 parts by weight of amorphous crosslinked fine particle dispersion 1, toner 21 was obtained by carrying out the same treatment as in the production of toner 20. The average particle size at this time was 6.0 μm.

<Manufacture of toner 22>
Except for adding 102 parts by weight of amorphous crosslinked fine particle dispersion 2, toner 22 was obtained by carrying out the same treatment as in the production of toner 16. The average particle size at this time was 6.2 μm.

<Manufacture of toner 23>
Crystalline polyester resin dispersion 1: 2727 parts by weight Amorphous resin fine particle dispersion 2: 102 parts by weight Release agent dispersion 1: 180 parts by weight Colorant dispersion 1: 72 parts by weight Calcium polysulfide: 1.44 parts by weight Part Calcium chloride: 0.92 parts by weight The above is placed in a round stainless steel flask and adjusted to pH 4.5, and then a homogenizer (manufactured by IKA: Ultra Turrax T50) is dispersed, followed by an oil bath for heating. Heat to 55 ° C. with stirring. After maintaining at 55 ° C. for 2.0 hours, observation with an optical microscope confirmed that aggregated particles having a volume average particle diameter of about 6.4 μm were formed. Further, after maintaining heating and stirring at 62 ° C. for 1 hour, it was confirmed by observation with an optical microscope that aggregated particles having a volume average particle diameter of 6.0 μm were formed. The pH of this aggregated particle dispersion was 5.2. Therefore, an aqueous solution obtained by diluting sodium hydroxide (manufactured by Wako Pure Chemical Industries, Ltd.) to 0.5 mol / L was gently added to adjust the pH to 7.5. When this aggregated particle dispersion was heated to 85 ° C. and kept for 60 minutes while continuing to stir, when observed with an optical microscope, coalesced spherical particles were observed. Thereafter, the temperature was lowered to 25 ° C. at a rate of 1 ° C./min while adding ion-exchanged water. Thereafter, the obtained coalesced particles were washed and then dried with a freeze dryer to obtain toner 23. The volume average particle size at this time was 6.1 μm.

<Manufacture of Toner 24>
The core particle 1 was not particularly treated, washed, and then dried with a freeze dryer to obtain a toner 24. The volume average particle size at this time was 6.0 μm.

<Manufacture of toner 25>
The core particles 2 were not particularly treated, washed, and then dried with a freeze dryer to obtain toner 25. The volume average particle size at this time was 6.2 μm.

<Manufacture of Toner 26>
The core particles 3 were not particularly treated, washed, and then dried with a freeze dryer to obtain a toner 26. The volume average particle size at this time was 5.8 μm.

<Manufacture of Toner 27>
Except for using 510 parts by weight of the amorphous resin fine particle dispersion 2, the same treatment as in the production of the toner 1 was performed to obtain a toner 27. Further, the volume average particle diameter at this time was 6.0 μm.

<Manufacture of Toner 28>
A toner 28 was obtained by carrying out the same treatment as in the production of the toner 16 except that 446 parts by weight of the amorphous crosslinked fine particle dispersion 1 was added. The average particle size at this time was 5.9 μm.

<Manufacture of toner 29>
A toner 29 was obtained by carrying out the same treatment as in the production of the toner 1 except that 102 parts by weight of the amorphous resin fine particle dispersion 12 was added. The volume average particle diameter was 6.3 μm.

<Manufacture of toner 30>
A toner 30 was obtained by performing the same process as in the production of the toner 1 except that 102 parts by weight of the amorphous resin fine particle dispersion 13 was added. The volume average particle size was 6.4 μm.

<Manufacture of toner 31>
A toner 31 was obtained by performing the same process as in the production of the toner 1 except that 102 parts by weight of the amorphous resin fine particle dispersion 14 was added. The volume average particle diameter was 6.2 μm.

<Manufacture of Toner 32>
A toner 32 was obtained by carrying out the same treatment as in the production of the toner 1 except that 26 parts by weight of the amorphous resin fine particle dispersion 2 was added. The volume average particle diameter was 6.0 μm.

<Manufacture of Toner 33>
Toner 33 was obtained by carrying out the same processing as in the production of toner 1 except that 172 parts by weight of amorphous resin fine particle dispersion 2 was added. The volume average particle diameter was 6.9 μm.

<Manufacture of Toner 34>
Except for adding 166 parts by weight of the amorphous crosslinked fine particle dispersion 1, a toner 34 was obtained by carrying out the same treatment as in the production of the toner 16. The average particle size at this time was 6.8 μm.

Example 1
<Evaluation of Toner 1>
(Fixability)
Toner 1 was added 1.2 parts by weight of titania fine powder as an external additive with respect to 100 parts by weight of toner and mixed with a stirring mixer to obtain a toner for developing an electrostatic image. Next, 5 parts by weight of this toner and 100 parts by weight of resin-coated ferrite particles (average particle size 35 μm) were mixed to prepare a two-component developer, which was then used as a commercially available electrophotographic copying machine (DocuCenter Color 500 manufactured by Fuji Xerox Co., Ltd.). (Hereinafter, DCC500)) was used to obtain an unfixed image having a toner concentration of 15 g / m ² . The paper used was Fuji Xerox J paper.

  Thereafter, the DCC 500 fixing machine was remodeled so that the set temperature could be changed, and the fixing property of the image was evaluated while gradually increasing the fixing temperature between 90 ° C. and 220 ° C. For low-temperature fixability, after fixing an unfixed solid image (25 mm × 25 mm), it is bent using a weight with a constant load, and the degree of image loss at the fold portion is observed, and some image peeling is observed. However, the fixing temperature at which the temperature is determined to be at or above the level at which there is no practical problem is set as the minimum fixing temperature, and is used as an index of low temperature fixing property. When evaluated by the above method, the minimum fixing temperature was 100 ° C.

(Heat storage)
2 g of the externally added toner of toner 1 was exposed to a temperature of 55 ° C. and a humidity of 50% for 24 hours, and then weighed on a sieve mesh having an opening of 53 μm and a diameter of 10 cm. After covering the upper cover to prevent toner scattering, it was vibrated for about 90 seconds with a powder tester manufactured by Hosokawa Powder Engineering Laboratory, and the amount of toner on the sieve was measured. In this case, the heat storage property was determined based on the following criteria with respect to the remaining amount on the net. As a result, the remaining amount of the 53 μm sieving screen on the screen was 0.20 g, and the heat storage property was sufficient.
○: Remaining amount on the net is less than 0.2 g and has sufficient heat storage property, and there is no practical problem Δ: Remaining amount on the net is 0.2 g or more and less than 0.5 g, sufficient heat storage property Practically acceptable x: The net remaining amount is 0.5 g or more, the heat storage property is insufficient, and there is a problem in practical use.

(Image evaluation)
After continuous printing of 10,000 sheets using a DCC500 manufactured by Fuji Xerox, image evaluation of the fixed image was performed from the viewpoint of the presence or absence of white spots, image density, fog, and glossiness. For the evaluation of the image density, X-Lite 404 was used, and the measured value was determined according to the following criteria.
○: The measured value is 1.2 or more, and there is no practical problem. Δ: The measured value is 1 to 1.2, which is practically acceptable. X: The measured value is less than 1, and practically unacceptable.

Further, fog was determined according to the following criteria. As a result, no white spot defect or the like was observed, and the level of fog was not problematic for practical use. Further, the image density was 1.5, which was a problem-free level.
○: No visible fog, no problem in practical use △: Some fog is observed visually, but acceptable in practice ×: Visual fog is remarkable, not practically acceptable

The glossiness was evaluated based on the method described in “JIS Z 8741-1997 Specular Glossiness—45 degree Specular Gloss of Measurement Method”. The glossiness was evaluated according to the following criteria using a gloss meter manufactured by Murakami Color Material Research Laboratory. The image was a Fuji Xerox DCC500, the fixing temperature was 180 ° C., the fixing speed was 264 mm / sec, and the paper was Fuji Xerox J paper.
○: Glossiness is 50% or more △: Glossiness is 30% or more and less than 50% ×: Glossiness is less than 30%

(Examples 2 to 23)
<Evaluation of Toners 2 to 23>
Toner fixing property, heat storage property, and image evaluation were performed in the same manner as in the case of toner 1. The results are shown in Table 1.

(Comparative Examples 1-11)
<Evaluation of Toners 24-34>
Fixing property, heat storage property, and image evaluation were performed in the same manner as in the case of toner 1. The results are shown in Table 1.

  The toners of Examples 1 to 23 all had sufficient low-temperature fixability, heat storage properties, and image characteristics. In Examples 2, 4, and 6, since the amorphous resin fine particle content was higher than those in Examples 1, 3, and 5, respectively, the result that the fixing temperature was increased by 5 to 15 ° C. was obtained. It was possible to achieve both fixing property and heat storage property. On the other hand, Comparative Examples 1 to 3 do not have a shell layer containing amorphous resin fine particles as a main component, so that the heat storage property is insufficient. Further, images such as white spots, density reduction, fogging, etc. Defects were observed. Further, in the toner of Comparative Example 4 containing a large amount of amorphous resin fine particles, the fixing temperature was greatly increased to 35 ° C., the low temperature fixing property was inhibited, and defects on the image were also observed. As a result, the toner using amorphous resin fine particles in the shell layer was obtained with excellent low-temperature fixability and heat storage properties. Further, when used in an actual machine, an additional result that the filming resistance to the photoreceptor is improved is also obtained.

  When Examples 7, 1, 8, 9, and 10 are compared, it can be seen that the heat storage property is improved as the Tg of the amorphous resin fine particles is increased. Comparative Example 6 in which the amorphous resin fine particles had a Tg of less than 65 ° C. had poor heat storage properties. Further, when Examples 11, 1, 12, 13, and 14 were compared, the glossiness was slightly deteriorated as the average particle size of the amorphous resin fine particles was increased, and in Comparative Example 8 where the average particle size was over 800 nm, the glossiness was reduced. Was not practical. Moreover, since the comparative example 7 with an average particle diameter of less than 20 nm has insufficient functions as a shell layer, sufficient heat storage properties cannot be obtained.

  In addition, the toners of Examples 16 to 22 using amorphous cross-linked fine particles in the shell layer all have sufficient low-temperature fixability and heat storage property, and no image defects were observed. In Examples 17, 19, and 21, since the amount of amorphous crosslinked fine particles was larger than that in Examples 16, 18, and 20, respectively, the result that the fixing temperature increased by 5 to 10 ° C. was obtained, but the low-temperature fixing property was hindered. It did not reach. Further, since the toner of Comparative Example 5 has an excessive amount of amorphous resin fine particles in the shell layer, in addition to an increase in fixing temperature, image defects such as white spots and fogging were caused. As described above, the toner using the amorphous crosslinked fine particles in the shell layer has a result of having a low temperature fixing property and a heat storage property. Further, when used in an actual machine, an additional result that the filming resistance to the photoreceptor is improved is also obtained.

  In Comparative Example 9 in which the amount of the amorphous resin fine particles added was less than 5% by weight, the function as a shell layer was insufficient, so that sufficient heat storage was not obtained. Comparative Examples 10 and 11 exceeding 25% by weight resulted in image defects such as white spots and fog in addition to an increase in fixing temperature.

  In addition, Example 23 in which core particle formation and shell layer formation were performed in the same process was inferior in shell layer uniformity compared to Example 1 in which core particle formation and shell layer formation were performed in separate processes. The heat storage was a little bad.

As described above, in the electrostatic image developing toner of this example, the binder resin contains at least one of a crystalline polyester resin and an amorphous resin, the shell layer contains amorphous resin fine particles, The volume average particle size of the amorphous resin fine particles is 20 to 800 nm, the glass transition temperature is 65 ° C. or higher, and the content of the amorphous resin fine particles is in the range of 5 to 25% by weight with respect to the weight of the core particles. By satisfying these requirements, it is possible to achieve both heat storage and low-temperature fixability, as well as sufficient filming resistance, no image defects, and good image gloss.

Claims (5)

A toner for developing an electrostatic image having a binder resin, core particles containing a colorant, and a shell layer covering the core particles,
The binder resin includes at least one of a crystalline polyester resin and an amorphous resin, and the shell layer includes amorphous resin fine particles,
The volume average particle size of the amorphous resin fine particles is 20 to 800 nm, the glass transition temperature is 65 ° C. or more, and the content of the amorphous resin fine particles is in the range of 5 to 25% by weight with respect to the weight of the core particles. A toner for developing an electrostatic charge image. The electrostatic image developing toner according to claim 1,
The toner for developing an electrostatic charge image, wherein the amorphous resin fine particles are amorphous crosslinked fine particles. A method for producing a toner for developing an electrostatic image having a binder resin, core particles containing a colorant, and a shell layer covering the core particles,
Forming a core particle containing a binder resin containing at least one of a crystalline polyester resin and an amorphous resin and a colorant;
An agglomeration step of forming amorphous resin adhering particles by adhering amorphous resin fine particles to the core particles;
A melting step of heating the amorphous resin adhering particles to form a shell layer;
The amorphous resin fine particles have a volume average particle size of 20 to 800 nm, a glass transition temperature of 65 ° C. or higher, and the content of the amorphous resin fine particles is 5 to 25% by weight of the core particles. %. A method for producing a toner for developing an electrostatic charge image, wherein   An electrostatic charge image developer comprising the electrostatic charge image developing toner according to claim 1. A latent image forming step for forming an electrostatic latent image on the surface of the latent image holding member and a developer carried on the developer carrying member are used to develop the electrostatic latent image formed on the surface of the latent image 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 fixing the toner image transferred on the surface of the transfer target. An image forming method comprising:
The image forming method according to claim 4, wherein the developer is the electrostatic charge image developer according to claim 4.